Pediatric: Hirschsprung's, Anorectal Malformations, and Other Conditions

51 Pediatric: Hirschsprung’s, Anorectal Malformations, and Other Conditions

Alberto Peña and Marc Sher

Hirschsprung’s Disease Usually the patient becomes symptomatic during the first 24Ð48 hours of life. Delayed passage of meconium (more Hirschsprung’s disease (congenital megacolon) is an anomaly than 24 hours), abdominal distention, and vomiting are the characterized by functional partial colonic obstruction caused most common symptoms. A rectal examination may produce by the absence of ganglion cells. It occurs in approximately 1 explosive passage of liquid bowel movements and gas, which in 5000 births. Boys are more frequently affected than girls dramatically improves the baby’s condition. This clinical and it is more common in Caucasians. A deletion in the long improvement only lasts for a few hours, after which the symp- arm of chromosome 10 has been found.1 The functional dis- toms recur. If the colon is not decompressed, the infant usu- turbances in this condition are attributed to the absence of ally suffers from sepsis, hypovolemia, and endotoxic shock. ganglion cells from the Auerbach’s myenteric plexus (located Cecal perforation may occur. About 25%Ð30% of these between the circular and longitudinal layers of smooth mus- babies die when unrecognized or not treated.2 Patients that do cle of the intestine), the Henle’s plexus (located in the sub- survive unrecognized and without treatment, ultimately mucosa), and the Meissner’s plexus (in the superficial develop the classic clinical picture initially described for this submucosa). The absence of these cells probably produces condition. They have severe constipation, a huge megacolon, uncoordinated contractions of the affected colon. This is and an enormously distended abdomen. This clinical situation translated into a lack of relaxation of the colon that results in is extremely rare nowadays in developed countries. partial colonic obstruction. Occasionally, these patients are misdiagnosed as having idio- The length of the aganglionic colonic segment varies. In the pathic chronic constipation. In the latter condition, the most common type, the aganglionic segment includes the rec- patients are not seriously ill, and it is very common for them tum and most of the sigmoid colon. Nearly 80% of all patients to have overflow pseudoincontinence (encopresis). A rectal have this type. In approximately 10% of the patients, the agan- examination discloses a rectum full of fecal matter. On the glionosis extends to the area of the splenic flexure or the upper contrary, patients with Hirschsprung’s disease usually have descending colon. Total colonic aganglionosis occurs in malnutrition, lack of normal development, an empty agan- another 8%Ð10% of the patients. In those cases, the absent glionic narrow rectum, and they do not have soiling. ganglion cells sometimes extend to the distal terminal ileum. The presence of the symptoms described in a newborn In the so-called “ultrashort” aganglionosis, the ganglion cells must alert the clinician to the diagnosis of Hirschsprung’s dis- supposedly are lacking only a few centimeters above the pecti- ease. An abdominal film shows massive dilatation of small nate line of the rectum. This is a rather controversial condition. bowel and colon. It is almost impossible to differentiate colon Very rarely, one can see patients who have universal agan- from the small bowel, in a plain abdominal film during the glionosis, meaning that the ganglion cells are absent in the newborn period. A contrast enema is used in most institutions entire gastrointestinal tract, which is a lethal condition. to clarify the diagnosis. The catheter should be introduced The clinical manifestations are those of a partial colonic only a few centimeters into the rectum in order to be able to obstruction. In addition, these patients have a poorly charac- visualize the nondilated aganglionic segment of the rectosig- terized immunologic mucosal defect that may explain why moid, followed by a transitional zone and then a proximal they suffer from an inflammatory process called enterocolitis, dilatation. These typical changes are often not obvious during which is the main cause of death. In addition, fecal stasis the neonatal period. The older the patient, the more obvious seems to promote the proliferation of abnormal colonic flora the size difference between normal and aganglionic segment. (Clostridium difficile) as well as production of endotoxins In patients with total colonic aganglionosis, the entire colon that contribute to the aggravation of the clinical condition. is not distended; the dilatation affects the small bowel only.

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A manometric study may show an absent rectoanal inhibitory stoma and multiple surgeries. However, approaches may vary reflex. However, this study is not considered reliable for this from country to country as with the surgeon’s experience. In diagnosis early in life but more helpful in the adolescent or addition, a primary procedure, without a protective colostomy, adult with unrecognized short segment disease. requires the presence of an experienced clinical pathologist, The definitive diagnosis is based on both the histologic familiar with the interpretation of frozen sections. Also, in the absence of ganglion cells, and the presence of hypertrophic case of a very ill, low-birth-weight newborn, or a very sick nerves in a rectal biopsy. These can be taken as full-thickness baby, a colostomy is still the optimal way to protect the patient. rectal biopsies under direct vision. More recently, a suction In the presence of an experienced pathologist, the colostomy biopsy has gained wide acceptance. The specimen, however, must be open in a normoganglionic portion of the colon. In the must include mucosa and submucosa. An important diagnos- absence of an experienced pathologist, the surgeon must open tic alternative is the determination of acetylcholinesterase the colostomy, proximal to the transition zone. If the transition activity in the mucosa and submucosa.3 zone is not evident, the colostomy should be done in the right transverse colon. In the event of a nondilated entire colon, the Medical Management patient should receive an ileostomy. The definitive procedure (resection of the aganglionic seg- Colonic decompression and irrigation with saline solution is ment and pullthrough of the normal ganglionic colon) can be the most valuable tool for the emergency management of done in different ways. Swenson and Bill4 described an oper- newborn babies. This maneuver may dramatically improve a ation consisting of an intraabdominal resection of the agan- very ill neonate. Irrigations should not be confused with ene- glionic segment including a part of the normoganglionic mas. An enema is a procedure in which an amount of fluid is dilated colon, and pullthrough of a normoganglionic bowel, instilled into the colon. It is expected that this fluid will be with a perineal anastomosis of the normoganglionic bowel to spontaneously expelled. Patients with Hirschsprung’s disease the rectum, above the pectinate line. are, by definition, incapable of expelling this fluid and, there- Duhamel7 described an operation designed to avoid pelvic fore, enemas are contraindicated. A colonic irrigation, how- dissection and potential nerve damage. He proposed to ever, promotes the expelling of the rectocolonic contents preserve the aganglionic rectum, dividing the colon at the through the lumen of a large rubber tube, which is cleared peritoneal reflection. The normoganglionic colon is then with small amounts of saline solution. Rectocolonic irriga- pulled through a presacral space, created by blunt dissection tions may save the baby’s life, but are not the ideal long-term and anastomosed to the posterior rectal wall above the form of treatment. Once the histologic diagnosis has been pectinate line. established, the baby must remain with nothing by mouth, and Soave8 designed an ingenious and appealing procedure the irrigations must continue in preparation for the surgical consisting of an endorectal (submucosal) dissection of the treatment. aganglionic colon, leaving a seromuscular cuff. He carried this dissection down to the rectum above the pectinate line. Surgical Treatment The normally innervated colon is passed through the muscu- lar cuff and anastomosed to the rectum. The purpose of The basis of the surgical treatment consists of the resection of this operation, again, was to avoid the perirectal dissection the aganglionic segment and pullthrough of a normogan- and its potential negative effects caused by denervation of glionic segment to be anastomosed to the rectum, immedi- pelvic organs. ately above the pectinate line. This should guarantee the The original Soave procedure was performed in two stages. preservation of bowel control. There are several ways to During the first stage, the colon was pulled down, but was not achieve these basic goals. The surgical treatment has evolved anastomosed to the rectum; it was left protruding outside the significantly since 1948 when the first surgical technique was rectum. In the second stage, a week later, the protruded described.4 bowel was resected and the anastomosis was performed. Originally, these patients were subjected to a staged treat- Subsequently, Boley9 proposed a primary anastomosis. ment. The first stage consisted of the opening of a diverting The abdominal portion of all of these operations can be colostomy. The second stage included the resection of the done laparoscopically. This has been advocated by a number aganglionic segment and pullthrough of the normoganglionic of pediatric surgeons recently.10Ð12 Georgeson and col- bowel, and the third stage was the colostomy closure. leagues10,11 described their technique of laparoscopically Subsequently, surgeons adopted a two-stage modality that obtained seromuscular biopsies in 80 patients to successfully included the opening of the colostomy during the newborn determine the transition point. They preserved the marginal period. The second stage consisted of the pullthrough, leaving artery establishing a colonic pedicle for anastomosis through the patient without a colostomy. four ports, laparoscopically. More recently, the treatment most often used consists of a In 1998, De la Torre-Mondragon and Ortega-Salgado13 neonatal primary procedure without a protective colostomy.5,6 and subsequently Langer et al.14 reported a novel, This approach is less invasive and avoids the morbidity of a transanal approach for the management of this condition. 51. Pediatric: Hirschsprung’s, Anorectal Malformations, and Other Conditions 715

They demonstrated that the whole procedure can be done In patients with Hirschsprung’s disease, stasis frequently transanally provided that the patient does not have a long seg- results in proliferation of abnormal bacteria, ulcerations of ment type of aganglionosis. A special retractor (LoneStarª; the colon, absorption of endotoxins, shock, and sometimes Lone Star Medical Products Inc., Houston, TX) is used to perforation. These patients respond to colonic irrigations; expose the dentate line as well as the rectal mucosa. occasionally they require a colostomy and a secondary We recommend the use of multiple fine sutures taking the pullthrough. rectal mucosa 1 cm above the pectinate line. These allow the Constipation may also occur after these procedures. It is surgeon to exert a uniform traction on the rectal mucosa. more common in patients in whom the aganglionic segment Peripheral to this series of silk stitches, an incision is per- was resected, but a dilated portion of the colon was pulled formed with cautery and a circumferential dissection of the down. This is a partially preventable condition. Most cases of rectum is performed applying uniform traction. The dissec- constipation can be avoided by resecting not only the agan- tion can actually be performed submucosally or full thick- glionic segment but also the dilated portion of the colon. ness, depending on the experience of the surgeon. As the Each one of the techniques described has its own advo- surgeon progresses in the dissection, full-thickness biopsies cates. The analysis of different series shows that the most are taken to determine the place where the normoganglionic important factor that affects the clinical results is the experi- portion of the colon is reached. The peritoneal reflection is ence and familiarity of the surgeon with each one of those soon found. It is recommended to continue the dissection procedures. Some surgeons claim that the Swenson operation until one reaches an area 4 cm above the transition zone to be exposes the patient to nerve damage that may provoke urinary sure that normoganglionic bowel is pulled down. The normo- and sexual disturbances. The Duhamel procedure is fre- ganglionic bowel is transanally anastomosed to the anal canal, quently followed by severe problems of constipation and 1 cm above the pectinate line. Because the majority of dilatation of the aganglionic piece of colon left in place. In the patients have a transition zone in the sigmoid colon, it is pos- Soave operation, patients may experience fecal incontinence, sible to repair the entire defect using this technique, without a as well as perianal fistulas and abscesses because of the pres- laparotomy or laparoscopy.13,14 When the transition zone is ence of islets of mucosa left in place during the endorectal located higher, the surgeon determines when he or she needs dissection. a laparoscopic-assisted procedure or a laparotomy. We specif- Advocates of a transanal approach cite the decreased mor- ically recommend resecting not only the aganglionic segment bidity and enhanced recovery as a consequence of a procedure of the colon, but also the very dilated part of the colon without the intraabdominal dissection.17,18 In addition, this because we have learned that a very dilated colon also has approach permits early postoperative feeding, shorter length very poor peristalsis. to stay, faster recovery, and possibly less chance for postoper- De la Torre-Mondragon and Ortega-Salgado13 and Langer ative adhesions. Langer17,18 compared the standard open et al.14 perform the rectal dissection submucosally, in a simi- approach to transanal Soave versus selective laparoscopic lar way to the reoperative ileoanal pouch repairs for pouch- visualization and reported a shorter hospitalization and sig- vaginal fistulas in adults described by Fazio and Tjandra.15 nificantly less overall cost to the healthcare system. There was Complications and postoperative sequelae can be divided a trend of lower complication rates, specifically less incidence into two categories: preventable and nonpreventable. of adhesive bowel obstruction. They recommended only Preventable complications should not occur because they are selective laparoscopy for children with long segment disease. caused by technical errors. A feared preventable sequela is fecal incontinence. This is likely related to injury to the con- Surgical Management of Total Colonic tinence mechanism. All these procedures were originally Aganglionosis designed to prevent this from happening, provided they are performed correctly. Dehiscence, retraction, stricture, We believe that the ideal treatment for this very serious condi- abscess, and fistula are all considered preventable because tion has not yet been found. The current treatment consists of they are usually caused by technical errors. During the resection of the entire aganglionic colon and pullthrough pullthrough, the surgeon must be familiar with the manipula- of the normal aganglionic terminal ileum to be anastomosed to tion of the blood supply and the arcades of the colon to guar- the rectum. To avoid fluid losses and in an attempt to decrease antee a good blood supply in the pullthrough colon. The the number of bowel movements per day, as well as to promote anastomosis should be done without tension. water absorption, Martin19 proposed to leave a part of the rec- A nonpreventable complication is enterocolitis. This is also tosigmoid and descending aganglionic segment in place. The unpredictable, and a rather mysterious condition. Despite normoganglionic terminal ileum is anastomosed in a latero- receiving a technically adequate operation, patients may have lateral manner to this colon and finally connected to the poste- this condition. The frequency of this condition varies16 and its rior aspect of the rectum as in the Duhamel procedure. Kimura etiology is unknown. We believe that fecal stasis is the most et al.20 proposed the use of a right colon patch with the hope of important predisposing factor. Fecal stasis occurring in creating a reservoir for water absorption. Another option is the the colon in a normal individual produces constipation. ileoanal J-pouch anastomosis; however, risks associated with a 716 A. Peña and M. Sher pelvic dissection are obviously higher. All these approaches NID has become popular because most surgeons expect to have proved to be rather simplistic. The stasis of stool in the find histologic abnormalities in patients who have undergone small bowel produces bacterial proliferation and enterocolitis. a technically correct operation for Hirschsprung’s disease and Rather than absorbing water, very often the intestine secretes still have symptoms of enterocolitis or constipation. It was also fluid into the lumen, producing a secretory diarrhea. Therefore expected that these histologic abnormalities would explain the we, as others, believe that a straight ileorectal anastomosis is pathophysiology of other colonic motility disorders. the preferred option, acknowledging that all patients with this Unfortunately, a precise correlation between histology and condition will have a poor quality of life. clinical manifestations is lacking. The histologic diagnostic criteria have not been standardized among different patholo- Surgical Treatment of Ultrashort Hirschsprung’s gists and different countries. In addition, the precise options for therapy have not been clearly established.24 The surgical treatment of the ultrashort-segment aganglionosis is as controversial as the existence of this condition. Normal individuals have an area of aganglionosis above the Anorectal Malformations pectinate line. The length of this aganglionic area has not (Imperforate Anus) been accurately or scientifically determined. This is the reason why the diagnosis of ultrashort Hirschsprung is so con- Anorectal malformations represent a spectrum of defects troversial. Some surgeons propose an operation called characterized by the absence of an external anal orifice. The myectomy, consisting of the resection of a strip of smooth overwhelming majority of the patients have an abnormal muscle from the anal verge up to the area where ganglion communication between the rectum and the perineum (per- cells are found. The results of this procedure, again, are ineal fistula), the vestibule (vestibular fistula), or the vagina highly controversial and there is no scientific basis to explain (vaginal fistula) in the female. In some female patients, rec- why this may improve the condition. More scientifically con- tum, vagina, and urethra are fused together forming a com- ducted studies are required to clarify this issue. mon channel (cloacal malformation) and open into a single Most cases of Hirschsprung’s disease are diagnosed early in external orifice. In the male, the communication is with the life, but a few patients reach their late teens and some are in urethra (rectourethral fistula), or the bladder (rectobladder adulthood before a diagnosis is made. Hirschsprung’s disease neck fistula). Only 5% of the entire spectrum of patients are in adults must be distinguished from other causes of megacolon born with no fistula. Anorectal malformations occur in about such as Chagas’ disease, volvulus, colonic inertia, Ogilvie’s one in every 5000 newborns. Males seem to have this condi- syndrome, and other disorders of central nervous system. tion slightly more frequently than females. The most common Typically, the disease in adults is of the ultrashort segment vari- type of defects seen in boys is a rectourethral fistula and the ety. An internal sphincterectomy may yield a satisfactory result most common type in girls is vestibular fistula. Table 51-1 as performed after a failed pullthrough procedure. shows our proposed classification of anorectal malformations. This operation involves removing a thin strip of the internal sphincter muscle in the posterior midline starting 1 cm Associated Anomalies above the dentate line. The strip should extend as far proximal as exposure allows, possibly up to 15 cm. Lynn describes a Urogenital abnormalities occur in about 50% of all patients transanal approach, but we prefer a posterior sagittal approach with anorectal malformations.25 The higher and more com- to enable a high myectomy.21,22 Anal manometry may aid in plex the anorectal malformations, the higher the incidence of assessment of the adequacy of the myectomy, because the resting tone pressure should be less than 30 mm Hg. TABLE 51-1. Current classification of anorectal malformations Male Neuronal Intestinal Dysplasia Perineal fistula Rectourethral fistula Neuronal intestinal dysplasia (NID) refers to a histologic con- Bulbar dition that includes hypertrophy of ganglion cells, immature Prostatic ganglia, hypoganglionosis, hyperplasia of the submucosal and Rectobladder neck fistula myenteric plexus, giant ganglion cells, as well as hypoplasia Imperforate anus without fistula or aplasia of the sympathetic innervations of the myenteric Rectal atresia Female plexus. These histologic abnormalities have been described as Perineal fistula 23 occurring in a localized or disseminated manner. Vestibular fistula The histologic diagnosis of NID requires a high index Imperforate anus without fistula of suspicion as well as the availability of special histologic Rectal atresia techniques and expertise. Not all pathologists agree as to the Cloaca Complex malformations existence of this condition. 51. Pediatric: Hirschsprung’s, Anorectal Malformations, and Other Conditions 717 urologic associated defects. Urologic malformations are having constipation. Conversely, the lower the malformation a common source of morbidity in these patients. About 90% the higher the incidence of constipation and the lower the of patients with a rectobladder neck fistula in males as well as incidence of fecal incontinence will be. in cases of cloacas with a common channel longer than 3 cm, have an associated urologic problem. Unilateral renal agene- Description of Specific Defects sis is the most common urologic anomaly encountered in children with these defects. Vesicoureteral reflux is the second Males most common abnormality. Other important abnormalities Perineal Fistula include cryptorchidism, hypospadias, renal ectopia, and hydronephrosis. This is the simplest of all defects. The rectum opens anterior Sacral and spinal abnormalities are also very common in to the center of the external sphincter in the area known as the patients with anorectal malformations. The sacrum is fre- perineum. The rectal orifice is usually incompetent, meaning quently abnormal. The sacral abnormalities also represent a that it is too narrow to allow normal passage of stool. spectrum that varies from a completely absent sacrum to a Sometimes, the end of the rectum lies immediately below a completely normal one, including different degrees of very thin layer of epithelium with an external opening located hypodevelopment. There seems to be a direct relationship at the base of the scrotum or sometimes at the base of the between the degree of sacral abnormality and the final func- penis. The meconium sometimes can be seen below that very tional prognosis. These patients also have hemivertebrae and thin layer of epithelium giving an impression of a black rib- as a consequence different degrees of scoliosis. The presence bon. The overwhelming majority of these patients have a nor- of hemivertebrae also seems to be related to a poorer func- mal sacrum, and less than 10% of them have associated tional prognosis. defects. The final functional prognosis is excellent,27 provided Twenty-five percent of patients with anorectal malforma- these patients receive adequate treatment. These patients can tions have a defect called tethered cord.26 The majority of be operated on during the newborn period. The ideal opera- patients with tethered cord have a bad functional prognosis. In tion consists of moving the orifice back to the center of the this condition, the cord is abnormally attached (tethered) to sphincter creating a normal-sized anus. the spine. During the natural growth of the baby, it is believed that the spine grows faster than the cord, producing traction Rectourethral Fistula on the nerve fibers that may produce functional disturbances in the motion of the lower extremities and may contribute to In this group of malformations, the rectum connects to the sphincter problems. urethra. In the most common subtype, the rectum opens into Hemisacrum is sometimes associated with an anorectal the lower part of the posterior urethra known as bulbar urethra malformation and there is always a mass located in the area of and, therefore, the defect is called rectourethral bulbar fistula. the sacral defect. An anorectal malformation with hemi- The rectum passes through a funnel-like striated sphincter sacrum and a presacral mass is known as the Currarino triad. mechanism to reach the lowest part of the posterior urethra. The most common sacral masses in these patients are a der- Eighty-five percent of these patients achieve bowel control moid, teratoma, lipoma, anterior meningocele, or a combina- when treated properly.27 Approximately 30% of them have tion of all these. These patients also have a poor functional other associated defects.27 prognosis. In the second subtype, the rectum opens into the upper part Approximately 8% of all patients with anorectal malforma- of the posterior urethra (prostatic) and therefore it is called tions have esophageal atresia. These patients usually have a rectoprostatic fistula. Only 60% of these patients achieve very high anorectal defect and other associated anomalies, bowel control later in life. Sixty percent of them have impor- especially urologic. tant associated defects.27 About 30% of patients with anorectal malformations also Most of these patients (rectourethral fistula) require a have some sort of cardiovascular congenital anomaly. Most colostomy at birth and subsequently (usually 1 month later) frequently seen are patent ductus arteriosus, atrial septal they receive the final repair of the malformation. Lately, some defect, ventricular septal defect, tetralogy of Fallot, as well as of the patients with rectourethral bulbar fistula have been other more complex malformations. Fortunately, only 10% of repaired primarily during the newborn period without a pro- patients have a cardiovascular malformation with significant tective colostomy. hemodynamic repercussions that requires surgical treatment. The perineum of patients with anorectal malformations The main concern in a patient with anorectal malformation have characteristic features that must be recognized by the cli- is whether or not the patient will have bowel control, urinary nician. The higher the malformation, the more tendency to control, and sexual function in the future. The higher the mal- have a flat perineum (flat bottom), meaning that the natural formation, the worse the functional prognosis will be. midline groove is absent and there is no distinguishable anal The higher the anorectal defect, the more likely the child dimple. The lower the malformation, the more prominent will have fecal incontinence, but the lesser the chance of the midline groove and the anal dimple. In patients with 718 A. Peña and M. Sher rectourethral bulbar fistula, there is a recognizable midline genitalia just outside the hymen. Rectum and vagina share a groove as well as an anal dimple and in patients with recto- very thin common wall. About 30% of these babies have prostatic fistula, there is conspicuous tendency for the associated defects. Ninety-three percent of these babies will perineum to be flat. Also, the anal dimple tends to be closer have bowel control when properly treated.27 The sacrum is to the scrotum, the higher the malformation. One can also usually normal. frequently see a bifid scrotum in cases of prostatic fistula. Vestibular fistula is frequently misdiagnosed as a rectovaginal fistula.29 Vaginal fistula is an extremely unusual Rectobladder Neck Fistula defect. It represents less than 1% of all the female defects. In those unusual cases of vaginal fistula, the rectum opens into This is the highest of all defects in male patients. The rectum the posterior vaginal wall deeper to the hymen. is connected to the bladder neck. Ninety percent of these Most of the vestibular fistula cases are successfully oper- patients have important associated defects. The perineum is ated on at birth without a colostomy. Unfortunately, many of frequently flat. The rectum is located above the funnel-like those patients have dehiscence and retraction when the surgi- sphincter mechanism (levator). These patients are the only cal technique used is not adequate. A secondary operation in ones that require a laparotomy or laparoscopy in addition to these cases does not render the same good result as in cases of the posterior sagittal approach to be repaired. Only 15% of a well-done primary procedure. these patients achieve bowel control later in life.27 Imperforate Anus Without Fistula Imperforate Anus Without Fistula It is uncommon to see this type of defect in females. All that This is a rather unusual anomaly that occurs in 5% of all chil- was mentioned about this defect in males is true about this dren with anorectal malformations. Half of them also have defect in females. Down’s syndrome. More than 90% of all patients with Down’s syndrome, who have an anorectal malformation, have Rectal Atresia this specific type of defect. Eighty percent of the babies with Down’s syndrome and this malformation will eventually have This condition does not differ from the same defect in males. bowel control when they receive an adequate operation. Approximately 90% of patients with this defect and without Cloaca Down’s syndrome also have bowel control.28 Patients with this malformation usually have a good sphincter mechanism A cloaca is defined as a malformation in which the rectum, and a good sacrum. vagina, and urinary tract are fused together forming a common channel. This single channel opens where the normal Rectal Atresia urethra is located in females. Externally, these babies have rather small-looking genitalia. Separation of the small labia This malformation occurs in only 1% of all cases. It consists allows the observer to see a single orifice, which confirms the of a complete or partial interruption of the rectal lumen clinical diagnosis of a cloaca. Cloaca represents another located between the anal canal and the rectum. The external spectrum of defects. The length of the common channel appearance of the perineum is normal. The malformation is varies from 1Ð7 or even 10 cm. The length of the common usually discovered when a nurse tries to take the rectal tem- channel is directly related to the final functional prognosis perature in a baby. The sacrum is normal as well as the for bowel and urinary control. The turning point seems to be sphincter mechanism. One hundred percent of these patients around 3 cm. Patients with a common channel shorter than will have bowel control after a correctly performed opera- 3 cm can be repaired posterior sagittally without opening the tion.25 abdomen and the prognosis for bowel and urinary control is good. However, cloacas with a common channel longer than Female Defects 3 cm represent a serious technical challenge. The operation Perineal Fistula frequently requires not only a posterior sagittal approach but also a laparotomy. The repair of those complex defects In these female babies, the rectum opens in what is called the requires experience and familiarization with pediatric urol- perineal body between the normal location of the anus and the ogy. The final functional prognosis is not very good in cases female genitalia. All that was described about this defect in with a long common channel.30 males is true for females. These patients can be repaired at Associated defects occur in about 90% of all patients with birth without a colostomy. The prognosis is excellent.27 a common channel longer than 3 cm. About 40% of patients with cloaca have hydrocolpos (a Vestibular Fistula very dilated vagina full of fluid). The dilated vagina com- This is by far the most common defect seen in female presses the trigone and may produce ureterovesical obstruc- patients. The rectum opens in the vestibule of the female tion, megaureters, and hydronephrosis. Approximately 40% 51. Pediatric: Hirschsprung’s, Anorectal Malformations, and Other Conditions 719 of the patients with cloaca also have different degrees of to perform a diverting colostomy and to postpone the main septation of the vagina and the uterus. This has important repair for a later date. future implications, impacting menstrual flow,31 as well as obstetric potential. Females It is also true in females that simple inspection of the per- Initial Management ineum will allow the surgeon to make a correct diagnosis during the neonatal period in most cases. Male Babies The presence of an anal opening in the perineum makes the Perineal inspection and urinalysis allows determingtion of the diagnosis of perineal fistula. likely type of malformation in about 90% of the cases. Sometimes it is difficult to see the opening of the rectum The presence of a perineal orifice, by definition makes the in the vestibule because the female genitalia are swollen at diagnosis of a perineal fistula. This is also true when the baby birth because of the effect of the maternal hormones. The has an external defect called “bucket-handle” malformation presence of a fistula in the vestibule establishes that diagno- that is a skin bridge in the midline in the area of the anal dim- sis. To make the diagnosis of a rectovaginal fistula ple. The presence of a good midline groove and an anal (extremely unusual defect) one would have to see meconium dimple, as well as meconium in the urine, means that the coming from inside the vagina, deeper than the hymen. The patient has a rectourethral fistula. A flat bottom and bifid presence of a single perineal orifice makes the diagnosis of a scrotum are signs of a very high malformation. cloaca. Diagnostic studies should be done after 24 hours of life, but If none of these signs are present after 24 hours, the baby not later than 36 hours. The reason for this is that it is neces- should have a cross-table lateral film in prone position. Most sary to wait until the most distal part of the rectum is dis- likely the baby has an imperforated anus with no fistula tended in order for it to be seen by any of the diagnostic (which represents 5% of all cases). modalities [magnetic resonance imaging (MRI), ultrasound, During the first 24 hours of life, the baby should be sub- CAT scan, or simple X-ray films]. Before 24 hours, the most jected to the same tests described for the male patient. If the distal part of the rectum is usually collapsed and it is difficult baby has a cloaca, an ultrasound of the abdomen should be to see by these diagnostic modalities. Also, in order for meco- performed not only in the upper abdomen to rule out nium to be forced through a tiny distal fistula, it is necessary hydronephrosis, but also in the lower abdomen to rule out the to wait until the intraluminal pressure is high enough to over- presence of hydrocolpos. Most babies with a cloaca need a come the tone of the striated muscle that surrounds the distal diverting colostomy. These babies should not be taken to the rectum, which usually happens after 24 hours. During the first operating room unless the surgeon has already ruled out the 24 hours, the clinician must try to answer two very important presence of hydrocolpos. The hydrocolpos must be drained at questions: Does the baby have an associated defect that birth, particularly when the baby has hydronephrosis. Before threatens his/her life? Does the baby need a primary repair or trying other procedures for the treatment of the hydronephro- a colostomy? sis and megaureter, the hydrocolpos must be drained, which These questions should be answered in this order. The usually will take care of these problems. baby should be examined to rule out the presence of cardiovascular defects. The patient will remain with nothing by Colostomy mouth, and insertion of a nasogastric tube is recommended to Colostomies in babies with anorectal malformation should be avoid vomiting and potential risk of aspiration. An ultra- totally diverting. Loop colostomies are contraindicated; they sound of the abdomen is indicated to rule out the presence of may allow the passing of stool from the proximal into the dis- hydronephrosis. An ultrasound of the spine is also useful to tal colon, producing direct fecal contamination of the urinary rule out the presence of tethered cord. An X-ray film of the tract. The ideal colostomy should be created in the descend- lumbar spine and the sacrum will rule out the presence of ing colon, with separated stomas. Both stomas should be sep- hemivertebrae and sacral abnormalities. A very abnormal arated enough as to allow the placement of a stoma bag over sacrum is usually associated with a very high defect. If after the proximal stoma. Distal to the mucus fistula, the baby 24 hours the surgeon is still not sure as to the type of defect should have enough length of colon to allow a comfortable that the baby has, a cross-table lateral film with the baby in pullthrough at the time of the main repair. prone position and the pelvis elevated should be performed. In cases of cloaca, the surgeon must also drain the hydro- This will show the location of gas inside a distended rectum. colpos through the abdomen. When the vagina is so distended If the rectum is visualized below the coccyx and the surgeons that it reaches the upper abdomen, it can be drained in the have experience with the neonatal repair of this malforma- form of a vaginotomy, suturing directly the vaginal wall to tion, the patient can be approached primarily. However, if the the abdominal wall. When the vagina is not that large, it can rectum is located higher than the coccyx, or the surgeons be drained with a tube that is exteriorized through a separate have no experience with these neonatal operations, it is better hole in the abdominal wall. 720 A. Peña and M. Sher

Two weeks after the colostomy, a high-pressure distal and cannot be accommodated within the available space of colostogram should be performed.32 This consists of injection the sphincter mechanism. Under those circumstances, it is of hydrosoluble contrast material through the distal limb of recommended to taper the posterior rectal wall as much as the colostomy to delineate the anatomy of the distal colon and necessary so as to be able to accommodate the rectum within to establish an accurate anatomic diagnosis. This is, by far, the the limits of the sphincter. It must be the posterior rectal wall most important diagnostic study in anorectal malformations. that is tapered, rather than the anterior wall so that a suture Trying to repair these malformations without a good distal line is not opposed to the urethral fistula that was closed. colostogram exposes the babies to serious injuries of the The limits of the sphincter are electrically determined. The urinary tract, particularly in males.33 only difference in the surgical treatment between the rectourethral bulbar fistula and the retroprostatic fistula is that the latter requires a more significant dissection to bring the Main Repair rectum down. Males Rectobladder Neck Fistula Perineal fistulas can be repaired performing a minimal poste- Fortunately, this malformation occurs in only 10% of male rior sagittal anoplasty. The baby is placed in prone position patients.27 This is the only defect that requires a laparotomy with the pelvis elevated. Multiple stitches are placed at the or laparoscopic assistance in addition to the posterior sagittal mucocutaneous junction of the fistula orifice. An incision operation.34 This is because the rectum is located too high to dividing the sphincter mechanism, posterior to the anal ori- be reached from below. The posterior sagittal incision is only fice, is performed, and the rectum is carefully dissected to be performed to create the path through which the rectum should moved back and relocated within the limits of the sphincter. be pulled down. A midline laparotomy or laparoscopy is per- During the dissection of the anterior rectal wall, special care formed. The rectum is dissected above the peritoneal reflex- must be taken to avoid injury to the posterior urethra, which ion. The surgeon must create a plane of dissection as close as is the most common and feared complication in these opera- possible to the bowel wall, but without injuring the rectal tions. The babies must have a Foley catheter in the urethra wall. One must keep in mind that the ureters and vas deferens during this operation. If the surgeon does not have enough run in the same direction toward the bladder neck and, there- experience and the baby has a very narrow fistula orifice, fore, one must keep those structures under vision during the a simple procedure called cutback can be done, consisting of a dissection of the rectum. The bladder neck is located about posterior cut of the fistula to make the orifice wider. Another 2 cm below the peritoneal reflexion and, therefore, it is very alternative in a very sick baby or when the surgeon does not easy to find the end of the rectum and to divide and suture the have enough experience is simply to subject the patient to fistula site. The rectum then must be mobilized to be pulled dilatations of the fistula. down through the tract that has been previously established In cases of rectourethral fistulas, the patients are subjected through the posterior sagittal incision. to a posterior sagittal anorectoplasty. The baby is placed in prone position with the pelvis elevated and with a Foley Imperforate Anus Without Fistula catheter in place. A posterior sagittal incision is performed between both buttocks running from the middle portion of the In cases of imperforate anus without fistula, the operation is sacrum to the base of the scrotum. The entire sphincter mech- not necessarily easier than in patients with a fistula because anism is divided exactly in the midline using an electrical the rectum is still intimately attached to the posterior urethra. stimulator to be sure to leave an equal amount of sphincter These patients are approached posterior sagittally, the poste- muscle on both sides of the midline. rior rectal wall is opened in the midline, and multiple stitches The posterior rectal wall is identified and is opened in the are placed in the edge of the rectal wall to exert uniform midline. The fistula is identified and multiple fine silk stitches traction and to facilitate the separation of the rectum from the are placed taking the rectal mucosa immediately above the urinary tract. fistula in order to exert uniform traction to facilitate the dis- Special care must be taken during the dissection of the section and separation of the rectum from the urethra. A sub- anterior wall to separate it from the urinary tract. These mucosal plane is established in the anterior rectal wall to patients more often require a rectal tapering, because usually avoid damage to the urinary tract. About 1 cm above the fis- they have a more dilated rectum. tula site, the dissection continues full thickness until the rectum is completely separated from the urinary tract. After this, Rectal Atresia a circumferential dissection with division of extrinsic vessels of the rectum is performed until enough length has been These patients also require a posterior sagittal approach. The gained to bring the rectum down to the perineum and to anas- entire sphincter mechanism is divided posterior sagittally. tomose it without tension to the skin in the area of the anal Both rectum and anal canal are opened posteriorly. The sphincter. Occasionally, we find that the rectum is very dilated dilated proximal rectum is anastomosed to the anal canal and 51. Pediatric: Hirschsprung’s, Anorectal Malformations, and Other Conditions 721 then the sphincter mechanism is meticulously reconstructed following a specific technical maneuver called “total urogen- in the midline. These patients have an excellent prognosis. ital mobilization.”35 Multiple 6-0 silk stitches are placed in the edge of the open common channel as well as the edges of the Female defects vagina. These stitches allow the surgeon to exert uniform traction on the entire urogenital structure. The urogenital channel Perineal Fistula is divided full thickness approximately 5 mm proximal to the The repair of this malformation is the same that was described clitoris, creating a plane of dissection that is very easy to find, for male patients, except that the rectum is usually separated between the common channel and the posterior aspect of the from the vagina so there is no risk of vaginal injury. pubis. In a matter of a few minutes, one can reach the upper portion of the pubis. Conspicuous fascial attachments exist Vestibular Fistula between the vagina, the genitourinary structures, and the upper part of the pubis. These fascial attachments are avascu- The complexity of this malformation should not be underesti- lar and are known as suspensory ligaments of the vagina and mated. The patient is placed in prone position with the pelvis urethra. These are divided and the retropubic fat is identified. elevated. Multiple fine silk stitches are placed at the rectal By dividing these suspensory ligaments, one can gain approx- vestibular orifice. A posterior sagittal incision is performed, imately 2 cm of mobilization of the urogenital structures. dividing the sphincter mechanism to find the posterior rectal Some extra dissection of the lateral walls of the vagina as well wall, which is easy to recognize. The main technical chal- as its dorsal wall gains another centimeter, and by doing that, lenge in the repair of this defect is represented by the common one can repair the urethra and the vagina in a very satisfactory wall that exists between the rectum and vagina. There is no manner. More than 50% of the patients with cloacas have a plane of separation between these two structures. One must common channel shorter than 3 cm and, therefore, it is possi- make two walls out of one. This is achieved by a meticulous ble to repair most of these defects with this reproducible dissection applying uniform traction with multiple silk technique. The blood supply after this mobilization is excel- stitches into the rectal lumen. The dissection must continue lent. Urethra and vagina are then sutured to the labia in their until the rectum has been completely separated from the new position. vagina. Usually the rectum of these patients requires very lit- The limits of the sphincter are electrically determined and tle mobilization because it is located significantly low. The marked with temporary silk stitches. The perineal body is limits of the sphincter are electrically determined, the perineal reconstructed with long-term absorbable sutures, the rectum body is reconstructed, and the rectum is placed within the lim- is placed within the limits of the sphincter, and the anoplasty its of the sphincter. is performed. The total urogenital mobilization does not change the final functional prognosis. Patients with a com- Rectovaginal Fistula mon channel of less than 3 cm and a good sacrum have more This is an extremely unusual defect.29 These malformations than an 80% chance of having bowel control and an 80% can be repaired posterior sagittally. The repair is the same as chance of having urinary control without bladder intermittent described for vestibular fistula, except that these patients catheterization.28 After the urethra and vagina have been require much more mobilization of the rectum in order to repaired, the urethral meatus is now located 5 mm deeper to move it down and relocate it in the center of the sphincter. the clitoris in a position that makes it perfectly visible which is important if the baby needs catheterization. Twenty percent Cloaca of these babies will require intermittent catheterization post- operatively in order to empty the bladder. Cloaca repair represents a significant technical challenge, particularly in patients with a long common channel.30 Surgical Repair of Patients with Cloaca with a Common Repair of Cloaca with a Common Channel Shorter Than Channel Longer Than 3 cm. We specifically recommend 3 cm. These patients are approached posterior sagittally. these patients to be referred to specialized centers dedicated The entire sphincter mechanism is divided in the midline and to the treatment of complex malformations. The repair of the posterior sagittal incision is extended down to the single these defects usually requires not only a posterior sagittal perineal opening. The common channel is also opened in the approach, but also a laparotomy and a series of decision- midline to expose the anatomy of the defect. The entire defect making steps that require experience and special training in can be repaired through this incision without opening the urology. The first part of the operation consists of perform- abdomen. Once the anatomy has been exposed, the first step ing a total body preparation so that the patient can be is to separate the rectum from the vagina, which is performed approached through the perineum (posterior sagittally) and in the same manner as was described for a rectovestibular fis- through a laparotomy. The posterior sagittal approach and tula. Once the rectum is separated, it should be mobilized to total urogenital mobilization is attempted because occasion- gain length and to be placed in a normal location. The next ally one can achieve a total repair in patients with a common step consists of mobilizing both vagina and urethra together, channel up to 4 cm. If this maneuver is not enough to make 722 A. Peña and M. Sher the vagina comfortably reach the skin of the perineum, one suprapubic cystostomy or vesicostomy at the end of the has to go into the abdomen and continue the dissection of the operation. One month after surgery, through the suprapubic vagina as well as its separation from the urinary tract. This is tube, a cystogram is performed, the tube is clamped, and a difficult and tedious maneuver. The bladder must be the patient is observed to see if she is capable of emptying opened and the ureters must be catheterized because they run her bladder spontaneously or if she requires intermittent through the common wall that separates the bladder and the catheterization. vagina. Once the vagina has been entirely separated from The most common sequela from the urinary point of view the urinary tract, then the surgeon evaluates whether or in babies with cloaca is the incapacity to empty the bladder. not the vagina reaches the perineum. If that is not possible, These babies do not have the type of neurogenic bladder that then he or she has to make an important decision as to the is seen in patients with spina bifida and myelomeningocele. best way to repair the malformation. In very specific cases, These patients rather have a floppy large bladder that does not with bilateral hydrocolpos, the surgeon can perform a empty. Most of the cloaca patients have a competent bladder maneuver called “vaginal switch,” consisting of resecting neck. The combination of a competent bladder neck with a one of the hemiuteri, resecting the vaginal septum, tubulariz- floppy hypotonic bladder makes these patients ideal candi- ing both hemivaginas to create a single one and switching dates for intermittent catheterization, which allows them to down what used to be the dome of one hemivagina to the per- remain completely dry. ineum, taking advantage of the fact that the distance between When the bladder neck was not present at birth or was both hemiuteri is longer than the vertical length of both destroyed during surgery, these patients will need a continent hemivaginas. This maneuver is only feasible if the patient diversion later in life. This operation usually will consist of has two large hydrocolpos. a bladder augmentation and creation of a conduit with a one- If this maneuver (vaginal switch) is not feasible, then the way valve mechanism that allows the patient to be catheter- surgeon must replace the vagina. The alternatives are first to ized intermittently in order to empty the bladder without urine replace it with rectum. The distal part of the rectum can be leakage. used to replace the vagina, which can be done in two different manners. If the patient has enough length of rectum, one can Results of Treatment of Anorectal Malformations use the most distal part (preserving its blood supply), to be separated from the fecal stream, mobilized forward, and About 75% of all patients with anorectal malformations replacing the distal part of the vagina. (when subjected to a good operation), have bowel control.27 In other cases, if the rectum is very dilated, one can divide The bowel control is not perfect. This becomes evident when it longitudinally. The anterior portion is tubularized and the patients have severe constipation, which may produce moved forward to form the neovagina preserving the neces- overflow pseudoincontinence, and soiling. Also, a severe sary vessels from the inferior mesenteric branches. The pos- episode of diarrhea may show that the bowel control is not terior aspect will serve as a rectum. The blood supply of the normal. Twenty-five percent of all patients have fecal inconti- posterior aspect will be provided intramurally from the nence and require some form of medical management. branches of the inferior mesenteric vessels. The rectum has an Because anorectal malformations cover a wide spectrum of excellent intramural blood supply. defects, the clinical and functional results vary depending on If these maneuvers are not feasible, the next choice could the specific type of malformation. Patients with a cloaca with be sigmoid colon. If the colostomy interferes with these a common channel longer than 3 cm usually have fecal incon- maneuvers, then one can use the small bowel. tinence and require intermittent catheterization to empty the In cases of extremely high malformations, one may find two bladder. Patients with cloaca with a common channel shorter little hemivaginas attached to the bladder neck. The rectum than 3 cm and a normal sacrum have bowel control 80% of the also may open in the bladder neck. The separation of these time and only 20% of them require intermittent catheteriza- structures is performed through the abdomen. Once the sepa- tion to empty the bladder and remain completely dry. Ninety- ration has been performed, one may notice that there is no four percent of all patients with rectovestibular fistulas have bladder neck left. Under those circumstances, the surgeon bowel control. Babies with perineal fistulas have bowel con- must have enough experience to decide whether or not the trol 100% of the time. Rectobladder neck fistula patients only bladder neck can be reconstructed or whether it is better to per- have bowel control 20% of the time, rectoprostatic fistula manently close the whole distal part of the bladder and open a 60%, and rectourethral bulbar fistula 85%.27 Patients with vesicostomy. Those patients will require a continent diversion imperforate anus with no fistula will have bowel control later in life. Because these patients have the highest incidence between 80% and 90% depending on whether or not they of vesicoureteral reflux, this operation through the abdomen have Down’s syndrome.29 represents a good opportunity to reimplant the ureters. Constipation is a problem in most patients with anorectal Patients with a common channel shorter than 3 cm are left malformations in whom the rectum was preserved during the with a Foley catheter, which stays in place for 2 or 3 weeks. main repair of the defect. Constipation should not be under- Patients with a common channel longer than 3 cm require a estimated as a problem. When not treated properly, the 51. Pediatric: Hirschsprung’s, Anorectal Malformations, and Other Conditions 723 patients develop megacolon and chronic fecal impaction, presence of an anal dimple, and strength of sphincter contrac- which may end up producing overflow pseudoincontinence. tion. A water-soluble enema or defecography, voiding cys- tourethrogram, sacral films, MRI with a rectal coil to assess the location of the rectum are essential. Manometry, anal Medical Management of Fecal ultrasound, and pudendal nerve terminal motor latency may Incontinence also be helpful. We then classify patients into four groups.39 “Group one” For the group of patients who have fecal incontinence (25% appears untrainable. They have a poor sacrum, flat perineum, of cases), there is a bowel management program that aims to poor muscles, no sensation, and poor bowel movement pat- keep those patients completely clean of stool and to make tern and usually are incontinent to both urine and all types of them socially accepted. The basis of this treatment is to teach stool. These patients are good candidates for a bowel man- the family or the patient to clean the colon every day with an agement program. If this program is unsuccessful, alternative enema or colonic irrigation. Because most patients have con- techniques such as the artificial bowel sphincter or stimulated stipation, the cleaning of the colon with an enema will prevent gracilis muscle flap may be tried40; however, a permanent the patient from passing stool for 24Ð48 hours.36 stoma is usually best suited and truly appreciated by these Occasionally, however, we find patients that had a different patients. type of repair and lost the rectosigmoid during the main repair “Group two” have clinical and MRI evidence of a mislo- or have intractable diarrhea or malabsorption. In those cases, cated rectum with a good sacrum and well-developed muscles. the bowel management is technically more demanding They benefit from a secondary pullthrough procedure by an because it includes not only cleaning the colon with an experienced surgeon with the aid of the Peña stimulator. enema, but also the use of a constipating diet or medications “Group three” has severe constipation and a contrast enema to decrease the colonic motility in order to keep the patient shows a severely dilated mega rectosigmoid. They benefit free of stool for more than 24 hours. from a sigmoid resection. The bowel management program is implemented over a “Group four” are patients born of the good prognostic type period of 1 week by trial and error. Every patient needs a dif- and have a well-located rectum, good sacrum, and good mus- ferent kind of enema to clean the colon. The cleaning of the cles but are still incontinent. They may benefit from biofeed- colon is monitored, taking X-ray films of the abdomen every back or other behavior modification programs to help them day, and readjusting the volume and concentration of the evacuate the rectum at controlled and predictable times. enema by trial and error. The goal is to find the enema that is Some children develop an irritable bowel syndrome as they well tolerated by the patient, is easy to administer, and keeps mature after a successful repair and then have difficulty later the patient completely clean. When the patient complains on in life. They may benefit from regulation of colonic motil- about the rectal enema and feels embarrassed about their par- ity with diet, medication, or possibly an intestinal pacemaker ents giving the enema, an operation called the Malone proce- that is on the horizon. It is the author’s opinion that control of dure (continent appendicostomy) is an option.37,38 This rectosigmoid motility and coordination will be of more value consists of creating a connection between the tip of the cecal in the future than any artificial or perhaps transplanted anal appendix and the umbilicus. The cecum is plicated around the sphincter. appendix, to create a one-way valve that allows the introduc- tion of a catheter through the umbilicus into the colon and prevents the colon from passing stool through the orifice. The Other Pediatric Colorectal Disorders patient is able to sit on the toilet, pass a little feeding tube through the umbilicus, administer the enema himself/herself, Idiopathic Constipation evacuate the colon, and remain clean the following 24 or 48 hours. This allows the patient to become independent. Constipation of unknown origin represents a serious problem A significant number of patients do not have an appendix. in the pediatric population. At least 6% of pediatric consulta- One can be created with a vascularized flap of the colon (con- tions are related to this particular problem.41 We consider this tinent neoappendicostomy). Then again, the colon is plicated condition to be the result of a colonic hypomotility disorder around the new appendix to make it continent.38 with different degrees of severity, affecting mainly the rectosigmoid and sometimes the entire colon. The spectrum of Relevant Aspects for Adult Colorectal Surgery colonic hypomotility or colonic inertia varies from mild constipation that can be controlled by dietetic measures, to severe Many adolescent and adult patients may still have fecal incon- hypomotility disorders that may fall into the realm of what is tinence despite successful repair in infancy. Work-up of these called “intestinal pseudoobstruction.” patients should include a detailed history and physical, i.e., Constipation means an incapacity to empty the colon on type of defect the patient was born with, bowel movement and a daily basis or incapacity to empty it completely. As a conse- voiding pattern, type of perineum, location of rectal opening, quence, the colon stores a large amount of stool, and becomes 724 A. Peña and M. Sher very dilated (megacolon). Megacolon produces constipation occasional failures. If all these procedures are unsuccessful, and constipation produces more megacolon, creating a the patient can be subjected to an abdominal approach and vicious cycle. The final result is what we call chronic fecal fixation of the rectum to the presacral fascia, usually with a impaction, which provokes overflow pseudoincontinence sigmoid resection. More recently, a perineal rectosigmoidec- (encopresis). tomy (modified Altemeier procedure) has emerged as a treat- The cause of this condition is unknown. Many authors ment option in these children mimicking a one-stage claim that the origin is a behavior problem, whereas others pullthrough for Hirschsprung’s disease. The advantages are believe that it is a consequence of a dietetic problem. There the same in that one avoids an abdominal operation and the are those who think that it is a consequence of a lack of relax- procedure may be repeated for recurrences. ation of the internal sphincter or a consequence of ultrashort segment aganglionosis. None of these theories have been sci- Perianal Fistula entifically documented, and that is why we call this condition idiopathic.42 Perianal abscess and fistula in pediatrics seems to be a com- So far, the treatment for this condition consists of trying to pletely different condition to that seen in adults. find the amount of laxatives that is capable of producing a During the first year of life, many babies (mainly males), bowel movement that empties the colon completely every have perianal abscesses that eventually become perianal fistu- day. The amount is different in every individual and has to be las. The orifice seen externally next to the anus communicates determined by trial and error. When the laxative requirement with one of the crypts of the pectinate line. Traditionally, is so high that it creates a problem in terms of quality of life, these patients have been subjected to a fistulotomy, consisting we offer the patient a surgical treatment consisting of the of identifying the fistula tract and cutting all the tissue, and resection of the most dilated portion of the colon (usually bowel wall, from inside the rectal lumen leaving the wound the rectosigmoid), creating an anastomosis between the open for granulation. nondilated part of the descending colon and the rectum.43 Our experience has been that this is a benign condition that By doing that, even when we are aware of the fact that we does not require any treatment. If the babies have a perianal do not cure this mysterious condition, we make the problem abscess, they do not require antibiotics. Very soon, the more manageable and reduce significantly the amount of abscess drains by itself and, if not, with a minimal incision laxatives that the patient needs. and drainage. After that, for a period of months, it drains intermittently without any discomfort to the patient. All 44 Rectal Prolapse fistulas disappear after 1 year of age. Occasionally, one can see a school-age child with a peri- Rectal prolapse occurs in children because of well-known anal fistula. This is extremely unusual. The surgeon should conditions such as myelomeningocele and spina bifida. The investigate the patient for the presence of inflammatory bowel lack of sphincter tone explains the severe prolapse from disease before trying any of the currently available surgical which these patients may suffer. Also, patients with cystic techniques used in adults. fibrosis or some patients with inflammatory bowel disease or intestinal parasites may have rectal prolapse. Juvenile Polyps Most pediatric patients afflicted by this condition are of the idiopathic type. The surgeon must try to identify one of the Around 4 years of age, patients might have polyps in the rec- predisposing conditions already mentioned. If this is not pos- tum and in the colon. These polyps are benign. They grow and sible, one must try to avoid those factors that we know exac- eventually amputate and disappear. The polyps are mostly erbate the problem, such as to avoid constipation and treat any located in the posterior rectal wall. A rectal examination irritating conditions of the colon, such as milk allergy. If all makes the diagnosis in most cases. These polyps have a long this fails, the surgeon can offer a palliative surgical treatment. pedicle. The symptoms in these patients are the presence of An old operation designed to treat rectal prolapse includes blood surrounding the fecal matter. They do not produce any a placement of a nonabsorbable suture around the anus to pain. Occasionally, the parents describe the presence of a restrict its caliber. The long-term results of these procedures polyp that prolapses through the anus. The polyps can be eas- are not good because eventually the patients develop mega- ily resected under general anesthesia in order to confirm the colon and an anal stricture. histologic diagnosis. Histologically, these are benign inflam- Other surgeons have tried the injection of sclerosing sub- matory polyps. Once the diagnosis is made, they can be stances in both perirectal spaces. This has been followed by predicted to have a benign course. severe complications including nerve damage and bowel and Even if the patient has another polyp, we know that even- urinary incontinence. A posterior sagittal approach has also tually it will self-amputate. These polyps do not produce been used which allows the surgeon to anchor the posterior significant bleeding. rectal wall to the cartilage of the coccyx and the sacrum. Most Occasionally, one may see juvenile polyposis that may of the patients are cured after this procedure, but there are require more aggressive treatment, but that is extremely rare. 51. Pediatric: Hirschsprung’s, Anorectal Malformations, and Other Conditions 725

Anal Fissure 12. Curran TJ, Raffensperger JG. The feasibility of laparoscopic Swenson pull-through. J Pediatr Surg 1994;29:1273. Anal fissures in pediatric patients are always a consequence 13. De la Torre-Mondragon L, Ortega-Salgado J. Transanal endorec- and not a cause of constipation. The fissure represents a lac- tal pullthrough for Hirschsprung’s disease. J Pediatr Surg eration that was produced with the passage of a hard large 1998;33:1283. piece of fecal matter. The patient has painful bowel move- 14. Langer JC, Minkes RK, Mazziott MV, et al. Transanal one stage ments and that contributes to the constipation problem, Soave procedure for infants with Hirschsprung’s disease. because the patient becomes a stool retainer. Stool retention J Pediatr Surg 1999;34:148. may provoke more constipation and more constipation will 15. Fazio VW, Tjandra JJ. Pouch advancement and neoileoanal anasto- make the fissure worse. mosis for anastomotic stricture and anovaginal fistula complicating restorative proctocolectomy. Br J Surg 1992;79: 694Ð696. The main treatment for this condition is to make the parents 16. Teitelbaum DH, Coran AG, Weitzman JJ, Ziegler MM, Kane T. understand the nature of the problem. It is necessary to give Hirschsprung’s disease and related neuromuscular disorders of enough laxatives so as to guarantee that the patient will have the intestine. In: O’Neill JA, Rowe MI, Grosfeld JL, Fonkalsrud soft stool passing through the rectum for several weeks until E, Coran AG, eds. Pediatric Surgery. 5th ed. St. Louis: Mosby; the fissure heals. No surgical treatment is necessary in fissures 1986:1381Ð1424. in children. 17. Langer JC, Seifert M, Minkes RK. 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