Retained Surgical Sponge

Now Online: Full-Text Articles and CE Testing at VetLearn.com Article #4 CE Retained Surgical Sponge

Vassiliki Tsioli, DVM Lysimachos G. Papazoglou, DVM, PhD, MRCVS Michail N. Patsikas, DVM, PhD, DECVDI George M. Kazakos, DVM Aristotle University of Thessaloniki Thessaloniki, Greece

ABSTRACT: Retained surgical sponge was diagnosed in four spayed and two castrated dogs over a 2- year period.The female dogs had undergone ovariohysterectomy and the male dogs perineal herniorrhaphy. Diagnosis was based on history as well as clinical and radiographic signs and was confirmed by surgical exploration. Five animals were available for follow-up (1 to 24 months) and were determined to be normal.

etained surgical sponge (RSS; also PATHOPHYSIOLOGY AND known as gossypiboma,a textiloma, and CLINICAL SIGNS R cottonoid) refers to a mass of cotton Intraabdominal RSSs made of cellulose fibers matrix retained in the body. Despite the use of may cause foreign body reactions resulting from sponges made of synthetic materials, the terms their lack of inertness and inability to disinte- gossypiboma and textiloma are still commonly grate.1 Two types of reactions have been de- used. Surgical sponges are commonly used to scribed in human medicine: keep the surgical field clean and dry or to aid in countertraction. • Aseptic serofibrinous responses leading to adhesion formation, complete encapsulation, 4,6,7 EPIDEMIOLOGY and foreign body granuloma Although rarely reported, RSS represents a • Exudative responses leading to abscessation continuing problem, mainly in human surgery1–8 and, to a much lesser extent, in small animal Septic complications may manifest in the early surgery, in which few reports have appeared in postoperative period in contrast to aseptic the literature.9–13 The true incidence of RSS is encapsulations, which may go undetected for unknown, possibly because of rare occurrence or long periods.5,7,8 Fifty percent of RSSs have reluctance to admit errors that may have reportedly been found 5 years or more after sur- medicolegal implications.5,7,12 In humans, RSS gery; one-third of humans with RSSs remain reportedly occurred in one of 1,000 to 1,500 asymptomatic, and their RSSs are detected laparotomies.5 In humans, RSS occurs mainly in incidentally.5 RSSs may also penetrate hollow emergency, general surgical, gynecologic, and viscera such as the intestine, bladder, or vagina obstetric procedures.8 because of pressure necrosis, resulting in intes- Email comments/questions to a tinal obstruction, infection, or gastrointestinal Gossypiboma is derived from 7,8,14 [email protected], gossypium (“cotton” in Latin) (GI) hemorrhage due to vessel erosion. The fax 800-556-3288, or log on to and boma (“place of conceal- most common clinical signs in humans include www.VetLearn.com ment” in Swahili). malaise, fever, anorexia, weight loss, signs sec-

COMPENDIUM 634 August 2004 Retained Surgical Sponge CE 635

ondary to intestinal obstruction, and bleeding from the trapped between the synthetic fibers of RSSs.4,14,15 This digestive or urogenital tract.3,6–8 pattern is considered to be characteristic of RSS. On RSS in dogs is associated with the infective, exudative CT, most RSSs demonstrate a variable-density appear- form of foreign body granuloma, resulting in clinical ance that makes interpretation difficult.16 A thin or, less signs that appear within months after surgery.12 Clinical often, thick capsule that surrounds a low-density center signs reported in dogs and cats with intraabdominal RSS has also been reported.4,15 Another rare sign on CT is include sinus discharge, palpable abdominal mass, ele- calcifications on the fibrous capsule or in the center of vated temperature, vomiting, diarrhea, painful abdomen, the RSS. Calcifications are commonly found in sponges depression, anorexia, and weight loss.12,13 In addition, that have been retained for a long time and have been in foreign body osteomyelitis9 and sarcoma formation10 contact with the GI or urinary tract.15 associated with RSS have been reported in dogs. The sonographic appearance of RSS varies, depending on the type of reaction (i.e., abscess or granuloma) that CLINICAL PATHOLOGY the sponge provokes and the presence of trapped fluid In a recent report involving eight dogs with RSS, neu- or gas.12,13 High amplitude echoes with acoustic shad- trophilia, microcytic anemia, leukopenia, thrombocy- owing may be representative of an RSS with trapped gas topenia, hyperglobulinemia, hypoalbuminemia, and or may be produced by the large number of interfaces

Using sponges with radiopaque markers may increase the possibility of diagnosing retained surgical sponge. elevated alkaline phosphatase levels were detected.12 resulting from sponge fibers.4,12,15 However, in cases of Cytologic examination after fine-needle aspiration of purely granulomatous lesions without abscessation, the the abdominal mass may allow identification of the acoustic properties may differ and the strongly echo- granulomatous nature of the tissue response.13 genic interfaces associated with acoustic shadowing have not been identified.13 DIAGNOSTIC IMAGING When sinus tracts are present, sinography may reveal Because of localized gas lucency resulting from air an RSS by filling its network of fibers.3,12 trapped between sponge fibers, conventional abdominal radiography may be used to detect RSS.8,12 Gas lucency DIFFERENTIAL DIAGNOSIS may appear speckled or vortex-like, persist for a long The differential diagnosis of intraabdominal RSS may time, and be mistaken for feces if recognized as a GI include the presence of a hematoma or an intestinal structure.12,14 mass.12,16 The speckled gas pattern due to RSS, as visual- Including radiopaque markers in sponges can make ized on plain radiographs, may be misinterpreted as feces them easier to detect on plain radiographs.1,5 The size unless it is recognized as a non-GI mass.12 On CT, an RSS and pattern of such markers may influence detection of with a radiopaque marker could be mistaken for a calcified RSS.2 However, some markers may twist, fold, or disin- hematoma.14 With ultrasonography, an RSS can be differ- tegrate over time or be superimposed over bony struc- entiated from an intestinal tumor, although they have simi- tures, making them difficult to see on plain radio- lar signs. With tumors, the gas-filled cavity communicates graphs.5,8 In addition, surgical clips may mimic the directly with the intestinal lumen on an ultrasonogram. pattern of radiopaque markers.14 This is not usually the case with RSS granulomas unless Abdominal computed tomography (CT) in humans migration into the intestinal lumen has occurred.12 may reveal a well-defined mass surrounded by a thick wall and internal heterogeneous densities, all represent- DIAGNOSIS ing the various contents of RSS: the synthetic-fiber for- The presence of nonspecific clinical signs and difficulty eign body, granuloma formation, and abscessation.8 A identifying RSS radiologically are responsible for difficul- spongiform pattern has resulted from gas bubbles ties in making the correct diagnosis. Diagnosing RSS

August 2004 COMPENDIUM 636 CE Retained Surgical Sponge

Sponge Counts in Human Medicine gical procedure and those with a high body mass index.18 A long, complex operation may cause a surgeon to lose track In human medicine, sponge, sharps, and instrument counts are relied on to eliminate the potential to of a surgical sponge. Time constraints may lead to incorrect leave foreign bodies in patients. The Association of sponge counts, especially in emergencies and unstable 5,7 periOperative Registered Nurses (AORN) recommends patients. In addition, personnel changes between the ini- counting instruments and sponges four separate times tial and last sponge count may increase the possibility of an during a procedure, but the counting process has not incorrect count.5 The risk of RSS might be less in dogs been standardized. The scrub and circulating nurses than in humans because of the smaller abdominal cavity share the legal responsibility for counting and and shorter, less complicated surgeries in dogs.12 confirming the number of sponges, but surgeons are often named in lawsuits involving RSSs. PREVENTION Recommendationsa Using radiopaque-marked sponges is recommended to • Sponges should be counted in all procedures. prevent RSS.7,12 The surgical team, including surgeons and • Sponges should be counted concurrently in the nurses, is responsible for following proper surgical proce- operating room by a nurse and another scrubbed person. dures and handling sponges correctly, including counting • Sponges should be counted before a cavity or any part sponges at the beginning of a procedure and before closing of a cavity is closed. the incision8 (see box on this page). After a change in per- • Types and sizes of sponges should be kept to a sonnel, the new personnel should perform two sponge minimum. All sponges used should be detectable counts.5,7 The abdomen should be meticulously explored radiographically. before closure to ensure that all sponges have been • Counted sponges should not be removed from the removed.5,7 In emergency or high-risk surgery or when a operating room during a procedure. sponge count is uncertain, routine intraoperative radi- • Radiographically detectable sponges should not be ographic screening should be conducted before closing an used as dressings. incision.5,7,18 aAdapted from Philippine College of Surgeons: Operating Room Standards. without radiopaque markers is more challenging than when markers are present. The diagnosis must be based on a history of surgery as well as survey abdominal radiography, ultrasonography, CT, sinography, and cytology of fine- needle aspirates showing the granulomatous lesion.7,12,13

TREATMENT In cases of RSS, failure to establish a diagnosis may prompt surgeons to perform inappropriately aggressive surgical therapy.3 Surgically removing an RSS and associated adhesions is the treatment of choice considering the extremely high complication rate.5 On rare occasions, when vital structures are involved in the adhesions, en bloc resection of the obstructed bowel or nephrectomy for hydronephrotic kidneys may be needed.17

PREDISPOSING FACTORS Several factors may lead to RSS. In a recent human study, patients at high risk of RSS included those undergo- ing emergency surgery with an unexpected change in a sur-

COMPENDIUM August 2004 Case Studies

From January 1998 to December 2001, six dogs in which RSSs were found during surgery were investigated. Data extracted from medical records included signalment, history, clinical signs, clinicopathologic findings, radiologic findings, surgical and pathologic findings, and outcome. Clinical data on the six dogs are presented in the table on page 640. Among the six cases, one had been previously reported.a Historical data included anorexia and depression (dogs 1, 2, and 3), weight loss (dog 2), vomiting (dog 3), hemorrhagic diarrhea (dog 2), and Figure A. Lateral abdominal radiograph of dog 1 showing hemorrhagic vaginal discharge and recurrent a radiopaque, non-GI foreign body in the ventrocaudal aspect of the abdominal cavity. (From Papazoglou LG, Patsikas estrus (dog 4). MN:What is your diagnosis? A retained surgical sponge. J Small Anim Abdominal radiography was conducted in dogs Pract 42:325, 363, 2001; with permission) 1, 2, 3, and 4. Radiologic examination in dog 1 revealed an opaque, metallic density, non-GI foreign body encased in a well-circumscribed, 4.5-cm–diameter, soft tissue density located in the right ventrolateral aspect of the caudal abdominal cavity (A). In dog 2, abdominal radiography revealed a linear opacity containing speckled and tubular gas lucencies at the middle aspect of the abdomen dorsal to the descending colon. Bone fragments in the dilated colon, which was displaced ventrally, and an air-filled small intestine compatible with bowel obstruction were also evident (B). A barium study confirmed the presence of bowel Figure B. Lateral abdominal radiograph of dog 2 showing obstruction. Abdominal radiography in dog 3 a linear opacity (arrow) containing speckled and tubular gas lucencies in the central abdomen dorsal to the descending revealed the presence of a semilunar-shaped, colon. Bone fragments in the dilated colon, which is displaced poorly defined mass caudally, which ventrally ventrally, and air-filled small intestinal loops are also evident. displaced the colon (C). Speckled gas lucencies throughout the mass were visible. Air-filled small intestine with no signs of obstruction was also seen. Radiologic examination of the caudal abdomen of dog 4 showed a poorly defined mass with a vortex-like gas lucency in the center (D). Mild ventral displacement of the descending colon was also evident. Lack of serosal detail around the mass was noted, and no signs of intestinal obstruction were detected. Radiologic examination was not conducted in dogs 5 and 6. Surgical exploration was performed in all dogs. Midline exploratory celiotomy was performed in dogs 1, 2, 3, and 4. In dogs 1 and 3, an RSS Figure C. Lateral abdominal radiograph of dog 3 showing incorporated in a mass was removed (E). There a semilunar-shaped, poorly defined mass with speckled gas lucencies in the caudal abdomen displacing the colon aPapazoglou LG, Patsikas MN: What is your diagnosis? ventrally. A retained surgical sponge. J Small Anim Pract 42:325, 363, 2001. Case Studies (continued)

were extensive adhesions between the mass and omentum. Abdominal lavage was performed, and the celiotomy was closed routinely. In dog 2, a sponge encased in a mass was found adhering to jejunum and causing extraluminal intestinal obstruction. The mass was removed en bloc with the intestinal segment, and an end-to-end intestinal anastomosis was made using 3-0 polydioxanone (PDS, Ethicon) in a simple- interrupted appositional pattern. The abdominal cavity was lavaged and closed in the usual manner. In dog 4, an RSS incorporated in a mass and adhering to the urinary bladder dorsally and Figure D. Lateral abdominal radiograph of dog 4 vaginal stump was located and excised (F and G). showing a poorly defined mass (arrows) in the caudal A residual left ovary was also removed. Following abdomen, with a vortex-like gas lucency in the center. Mild ventral displacement of the colon is also evident. lavage, the celiotomy incision was closed in a routine fashion. Dogs 5 and 6 underwent surgical exploration of their discharging sinuses through a revision of the original herniorrhaphy incision (H). RSSs were located and removed. Adhesions between the sponge, levator ani, anal sphincter, and retroperitoneal fat in dog 1 and obturator muscle and retroperitoneal fat in dog 6 were found. The pelvic diaphragm was reconstructed by using interrupted sutures of 2-0 polypropylene (Prolene, Ethicon). Histopathology of the mass was conducted in dog 2, confirming the presence of an infective granulomatous lesion.

Recovery All patients had a good recovery from Figure E. RSS encased in a granulomatous mass in anesthesia. Mean hospitalization time was 2.4 dog 1. (With permission from Papazoglou LG, Patsikas MN: days (range: 2 to 4 days). Dog 4 appeared What is your diagnosis? A retained surgical sponge. J Small Anim Pract 42:325, 363, 2001) depressed and anorectic 24 hours after surgery. Physical examination revealed abdominal distention, and abdominocentesis detected uroperitoneum. The owner declined further surgery and decided to have the dog euthanized. At necropsy, rupture of the right ureter was revealed. Follow-up information was obtained by reexamination and telephone calls to owners or referring veterinarians. Mean follow-up time was b 12.2 months (range: 1 to 24 months). Dogs 1, 2, 3, 5, and 6 were said to be in good health.

Discussion RSS following surgery is a continuing problem in humans and animals. Reasons for a falsely low incidence, particularly in animals, include Figure F. Exploratory celiotomy in dog 4 revealing a mass (*) adhering to the bladder (b) dorsally. misdiagnosis, failure to pursue a diagnosis, and a Clinical Data for Six Dogs with Retained Surgical Sponges

Duration Results of Culture Case Age of Signs Clinicopathologic and Cytology Number Breed Sex (y) Weight Previous Surgery Clinical Signs (wk) Findings of the Mass Outcome

1 Mixed FS 10 110 lb Ovariohysterectomy Fever 20 Neutrophilic leukocytosis No growth Normal after 1 mo (50 kg) to treat pyometra Infective granuloma

2 Mixed FS 2 37.4 lb Elective Fever 4 Normocytic, normochromic Staphylococcus spp Normal (17 kg) ovariohysterectomy after 6 mo Pale mucous anemia of chronic disease Infective membranes Neutrophilic leukocytosis granuloma Poor body Total protein: 4.28 g/dl condition Albumin: 1.08 g/dl Painful palpable abdominal mass

3 Doberman FS 3 52.8 lb Elective Poor body 4 Normal Staphylococcus spp Normal ovariohysterectomy condition pinscher (24 kg) Infective after 24 mo Palpable granuloma abdominal mass

4 Maltese FS 3 11 lb Elective Hemorrhagic 40 Neutrophilic leukocytosis Aseptic Euthanized cross (5 kg) ovariohysterectomy vaginal discharge granuloma Palpable abdominal mass (Figure F, p. 639)

5 Mixed MC 7 33 lb Perineal Perineal sinus 40 Normal — Normal (15 kg) herniorrhaphy (right) after 12 mo (bilateral)

6 German MC 7 55 lb Perineal Perineal sinus 2 Normocytic, normochromic — Normal shepherd (25 kg) herniorrhaphy (right; Figure H, anemia of chronic disease after 18 mo (right) p. 642)

FS = female, spayed; MC = male, castrated. Case Studies (continued)

lack of necropsies. The abdominal cavity has reportedly been the most common site in which RSSs are found in animals,12,13 which agrees with the study findings presented here. However, two cases of RSS after perineal herniorrhaphy were reported for the first time in this article. The most common initial surgical procedure reported here and elsewhere12,13 was ovariohysterectomy because it is the most common surgical procedure in small animal medicine. Clinical signs of RSS in small animals are often vague and nonspecific. Historical data indicating previous surgery are very helpful in making a Figure G. RSS enclosed in a granulomatous mass in diagnosis. A palpable abdominal mass has been a dog 4. common clinical finding in this study and others.12,13 Radiographic examination of the abdomen in three of our cases revealed a vortex- like or speckled, localized, gas lucency pattern. Radiologic findings in this study were consistent with previous reports of RSS.12 In dog 1, the presence of a radiopaque marker made diagnosis easier, but the characteristic gas lucency pattern was not obvious. The differential diagnosis of abdominal RSS may include granuloma, abscess, hematoma, tumor, or even feces. Abdominal radiography, ultrasonography, or CT may help in differentiation. Two of the dogs in our study that had initially undergone perineal herniorrhaphy presented with discharging sinuses in the perineal region. Common causes of sinus discharge following this type of perineal surgery may Figure H. Discharging sinuses in dog 6 in the right include rectal lumen or anal sac penetration due perineal region (arrows) following herniorrhaphy. to misplaced sutures or suture reaction. Surgical exploration and RSS removal were performed in all dogs in our study. Adhesions were sometimes extensive, and vital structures were involved. In one dog, the obstructed bowel was resected along with RSS removal. However, failure to recognize adhesion of the sponge to the right ureter in another dog in this study led to ureter rupture during sponge removal, resulting in uroperitoneum and euthanasia of the patient. This might have been prevented by carefully identifying and preserving vital structures during sponge removal. In three dogs with intraabdominal RSS in our study, the RSSs were encased in an infective, exudative form of Figure I. Sponges commonly used in small animal granuloma as revealed cytologically or surgery: A 4 × 4–inch surgical sponge (left) and histopathologically. All of these patients laparotomy sponge with radiopaque markers. presented with clinical signs that developed 1 to Retained Surgical Sponge CE 643

Case Studies (continued)

5 months after initial surgery. As previously reported, granuloma associated with RSS is the most common type of foreign body granuloma in veterinary patients.12 However, an aseptic, nonexudative type of sponge granuloma in a dog and cat has also been described.13 In our study, an aseptic form of sponge granuloma was found in one dog that presented with signs of ovarian remnant syndrome without signs of a mass, which was an incidental finding during abdominal palpation and radiography. To prevent the serious problem of RSS, sponges with radiopaque markers can be used (I and J), laparotomy sponges instead of small sponges can be used for celiotomy, and standards for sponge counting should be established and followed in Figure J. Radiograph of the sponges in Figure I. every practice.

REFERENCES 15. Kokubo T, Itai Y, Ohtomo K, et al: Retained surgical sponges: CT and US 1. Williams RG, Bragg DG, Nelson JA: Gossypiboma: The problem of the appearance. Radiology 165:415–418, 1987. retained surgical sponge. Radiology 129:323–326, 1978. 16. Kalovidouris A, Kehagias D, Moulopoulos L, et al: Abdominal retained sur- 2. Revesz G, Siddiqi TS, Buchheit WA, Bonitatibus M: Detection of retained gical sponges: CT appearance. Eur Radiol 9:1407–1410, 1999. surgical sponges. Radiology 149:411–413, 1983. 17. Hardie EM: General abdominal surgery, in Lipowitz AJ, Caywood DD, 3. Serra J, Matias-Guiu X, Calabuig R, et al: Surgical gauge pseudotumor. Am J Newton CD, Schwartz A (eds): Complications in Small Animal Surgery. Balti- Surg 155:235–237, 1988. more, Williams & Wilkins, 1996, pp 343–364. 4. Choi BI, Kim SH, Yu ES, et al: Retained surgical sponge: Diagnosis with CT 18. Gawande AA, Studdert DM, Orav EJ, et al: Risk factors for retained and sonography. Am J Radiol 150:1047–1050, 1988. instruments and sponges after surgery. N Eng J Med 348:229–235, 2003. 5. Rappaport W, Haynes K: The retained surgical sponge following intraabdominal surgery. Arch Surg 125:405–407, 1990. 6. Botet del Castillo FX, Lopez S, Reyes G, et al: Diagnosis of retained abdom- ARTICLE #4 CE TEST inal gauge swabs. Br J Surg 82:227–228, 1995. This article qualifies for 1.5 contact hours of continuing CE 7. Gonzalez-Ojeda A, Rodriquez-Alcantar DA, Arenas-Marquez H, et al: Retained foreign bodies following intra-abdominal surgery. Hepato-Gastroen- education credit from the Auburn University College of terology 46:808–812, 1999. Veterinary Medicine. Subscribers who wish to apply this 8. Lauwers PR, Van Hee RH: Intraperitoneal gossypibomas: The need to count credit to fulfill state relicensure requirements should consult sponges. World J Surg 24:521–527, 2000. their respective state authorities regarding the applicability 9. Teague HD, Alsaker R, Braden TD, Caywood DD: Two cases of foreign- of this program. To participate, fill out the test form inserted body osteomyelitis secondary to retained surgical sponges. Vet Med Small Anim Clin 73:1279–1286, 1978. at the end of this issue. To take CE tests online and get real- 10. Pardo AD, Adams WH, McCracken MD, Legendre AM: Primary jejunal time scores, log on to www.VetLearn.com. osteosarcoma associated with a surgical sponge in a dog. JAVMA 196:935–938, 1990. 11. Lamb CR, White RN, McEvoy FJ: Sinography in the investigation of drain- 1. Which statement regarding the pathophysiology ing tracts in small animals: Retrospective review of 25 cases. Vet Surg 23:129–134, 1994. of RSS in humans is false? 12. Merlo M, Lamb CR: Radiographic and ultrasonographic features of retained a. Intraabdominal RSS may result in aseptic encapsula- surgical sponge in eight dogs. Vet Radiol Ultrasound 41:279–283, 2000. tion. 13. Mai W, Ledieu D, Venturini L, et al: Ultrasonographic appearance of intra- b. Intraabdominal RSS may cause an exudative abdominal granuloma secondary to retained surgical sponge. Vet Radiol response. Ultrasound 42:157–160, 2001. c. Aseptic encapsulations may go undetected for long 14. Kopka L, Fisher U, Gross AJ, et al: CT of retained surgical sponges (textilo- mas): Pitfalls in detection and evaluation. J Comput Assist Tomogr periods. 20:919–923, 1996. d. In most patients, RSSs are detected incidentally.

August 2004 COMPENDIUM 644 CE Retained Surgical Sponge

2. Which statement regarding the pathophysiology b. The differential diagnosis of intraabdominal RSS may of RSS in animals is false? include the presence of an intestinal mass or a a. An infective, exudative form of foreign body granu- hematoma. loma is frequently discovered. c. A marked RSS can be mistaken for calcified hema- b. Reported cases of RSS in dogs are most often associ- toma on CT. ated with an aseptic foreign body granuloma. d. On an ultrasonogram, an RSS may be differentiated c. Reported cases of RSS in dogs are most often associ- from an intestinal tumor. ated with an infective, exudative type of foreign body granuloma. 7. Which statement regarding RSS prevention is d. Clinical signs of RSS in animals with an infective, false? exudative granuloma may appear within months after a. Proper handling of sponges is an important part of surgery. RSS prevention. b. Using sponges without radiopaque markers may 3. Which clinical sign does not occur in animals increase the risk of retention. with RSS? c. In emergencies, routine intraoperative, radiographic a. stertorous breathing screening before closing an incision is advised. b. a palpable abdominal mass d. Meticulous abdominal exploration before closing an incision is advised. c. sinus discharge d. vomiting 8. Which statement regarding predisposing factors associated with RSS is false? 4. Which statement regarding radiopaque-marked a. Risk factors that have been identified in humans sponges is false? include emergency surgery, high body mass index, and a. Marked RSSs may be easier to detect on plain radio- an unexpected change in a surgical procedure. graphs. b. A long, complex operation may cause a surgeon to b. RSS markers may disintegrate, making them easier to lose track of a surgical sponge. detect on plain radiographs. c. The risk of RSS might be less in dogs than in humans c. Surgical clips may mimic the pattern of radiopaque because of the high body mass index of dogs. markers. d. In emergencies, time constraints may lead to an d. RSS markers may migrate over bony structures, mak- incorrect sponge count. ing them difficult to visualize on plain radiographs. 9. Which statement regarding the retrospective 5. Which statement regarding radiographic signs of study reported in this article is true? RSS is false? a. The median duration of clinical signs was 12 weeks. a. Gas lucencies resulting from air trapped between the b. Radiographic examination in one dog revealed a fibers of an RSS facilitate radiographic detection. metallic density, GI foreign body. b. Gas lucencies caused by RSSs may be mistaken for c. No palpable masses were detected during physical feces. examinations of the dogs. c. Gas lucencies may result from air produced when d. Hydronephrosis was detected during abdominal cellulose sponge fibers disintegrate. exploration in one dog. d. Gas lucencies caused by RSSs may appear in a vortex-like pattern. 10. did not cause perineal sinuses following perineal herniorrhaphy in the study reported in this article. 6. Which statement regarding the differential diagnosis of RSS is false? a. Rectal penetration due to misplaced sutures a. If recognized as a non-GI mass, the speckled gas pat- b. Constipation tern due to an RSS may be mistaken for feces on c. Anal sac penetration due to misplaced sutures plain radiographs. d. RSS

COMPENDIUM August 2004