OPEN ACCESS TEXTBOOK OF GENERAL SURGERY UNDESCENDED TESTIS & INGUINAL HERNIA AJW MILLAR RA BROWN UNDESCENDED TESTIS the gonad to the developing inguinal Incomplete testicular descent is one of region and future scrotum. the most common malformations Meanwhile the processus vaginalis encountered in the male. Controversy testis, an outpouching of the remains regarding the aetiology, peritoneum invades the pathophysiology and optimal gubernaculum. Testicular descent treatment. Testicular development from its intra-abdominal position, and descent is a complex event and is through the inguinal canal takes place effected by multiple factors, during the 8th intra-uterine month with mechanical and hormonal, for its concomitant increase in the length of normal completion. Abnormalities in the vas deferens and testicular one or more of these can lead to an vessels. abnormal final gonadal location. The left testis is said to precede the Definition right in descent. An undescended testis must be After descent the bulky gelatinous regarded as a testis that is not in the gubernaculum shrinks to thin fascial scrotum, was never there and cannot attachments. be brought down into the scrotum. Hormonal factors play a major role in Embryology: Development and descent, e.g. maternal chorionic descent. Testicular development is gonadotrophic hormones and foetal determined at the time of conception interstitial cell activity with androgenic by the presence of the SRY (sex- hormone production. Other hormones determining region on the short arm of implicated are: the Y chromosome). Sexual · Descendin. an androgen differentiation begins at 7-8 weeks independent factor that provides gestation when the developing testis gubernacular cellular growth and arising from the genital ridge secretes · Estradiol. high levels in mothers testosterone (Leydig cells) and may inhibit gubernacular growth. Mullerian inhibiting substance (MIS) (Sertoli cells). Testosterone allows the Man is the only animal in which the Wolffian ducts to develop into an testis descends before birth and with epididymis, vas deferens and seminal the chimpanzee are the only 2 in vesicle, while MIS causes regression which the testis resides permanently in of Mullerian duct structures. Distal to the scrotum. The current concept of the developing gonad the the hormonal control of testicular gubernaculum proliferates, connecting descent is that transabdominal descent is mediated by gubernaculum structures of testicular parenchyma enlargement under the control of MIS. become apparent and become more Inguinoscrotal migration is indirectly abnormal as the malposition persists. under testicular control through The changes are present in bilateral androgen secretion. Disturbance of and unilateral undescended testis, and the hypothalamo-pituitary testicular in the latter situation, also in the axis will interfere with the androgen contralateral scrotal testis. In dependent transinguinal descent to a summary there is decreased tubular variable extent. size, decreased number of spermatogonia, atrophy of Leydig cells Aetiology of incomplete descent and interstitial fibrosis. Orchidopexy Failure of descent is likely to stem should be done early, before changes from two factors: become irreversible and theoretically · Inherent defect in the testis, or this should improve maturation after failure of hormonal environment the testis is brought down. (vide supra) · Mechanical defect preventing the Diagnosis otherwise normal testis from descending correctly, as genital Undescended testis must be development is usually normal. differentiated from a retractile testis Occasionally a malpositioned testis where there is: is noted which is not really `undescended', but has been 1. a history of a testis being felt or hitched up out of the scrotum seen in the scrotum following herniotomy. 2. a normally developed scrotum on that side Side: R/L 55%/45% 3. a testis of normal size that can Bilateral: 15-20% be manipulated into the scrotum Incidence Preterm infant 21% 75% of undescended testes referred Full-term 2.7% for a specialist opinion are retractile Age one year 1% NOTE that both squatting and the Family history 14% `chair test' where the knees are pulled up against the chest and the patient is The testis should be in the scrotum of examined relax the cremaster muscle a full-term baby. If not, then some allowing a retractile testis to be spontaneous late descent may occur manipulated into the scrotum. The in two-thirds of full-term babies by 6 cremaster reflex is absent in the weeks of age, and in 3 months for newborn and maximum at age 7-8 premature infants. Minimal descent years. occurs after one year. Types Histology of Undescended Testes a. Incomplete descent - arrested Normally age dependent in its normal line of descent morphological changes are seen from b. Ectopic - deviated from its infancy to adulthood. These changes normal line of descent after are caused by a congenital defect or traversing the external ring. by secondary alteration due to the malposition. Morphological changes Incomplete descent are not seen within the first 12 months · Abdominal - between the lower of life. Beginning with the second pole of the kidney and the year histological changes involving all internal ring · Entrant inguinal - above the The `Ascending' testis internal ring, but may enter the inguinal canal (impalpable) An apparently normally descended · Inguinal - lying in the inguinal testis in infancy but is later (± 4 yrs) canal (usually impalpable) noted to be incompletely descended. · Emergent inguinal - can be This is thought to be due to partial milked from the inguinal canal absorption of the patent processus to emerge from the external vaginalis into the parietal peritoneum ring when it becomes palpable. in the first years of life. · High scrotal - testis cannot be manipulated to the bottom of Treatment the scrotum, and lies at the entry to the scrotum. Orchidopexy - that is mobilising the testis, its vascular supply with vas Ectopic deferens and placing it in the scrotum · Superficial inguinal ectopic - usually in a sub-dartos pouch. Age at lies in the superficial inguinal operation: approximately 2 years. In pouch lateral to the external bilateral impalpable testis plus atrophic ring penis and scrotum - evidence of · Pubopenile - at the base of the testicular tissue should be proven prior penis to operation (Testosterone levels with · Perineal - in the perineum HCG Stimulation Test). Laparoscopy outside the scrotum is an excellent method of identifying the presence or absence of an intra- · Femoral - in the upper thigh abdominal testes when it is impalpable. Clinical examination Reasons for operating Should be conducted in a warm room having gained the confidence of the 1. To improve fertility. patient. Look first for development or Unilateral undescent - 80% fertile abnormality of the genitalia. Warm (after orchidopexy) hands. Gently bring the hand down Bilateral undescent - 30% fertile from the ASIS towards the pubis to (after orchidopexy) ?less for intra- milk the testis out of the inguinal canal. abdominal testis If the testis is visible in the groin it is 2. Torsion is more likely in an probably ectopic. undescended testis (10% torsion occur in UDT) If the testis is difficult to feel or pick up 3. Prone to trauma (uncommon) between the fingers, it is probably in 4. 70% associated with patent the inguinal canal. processus vaginalis therefore predisposes to hernia The Impalpable Testis 5. Psychological When a testis is impalpable, it may be 6. Malignant potential 20-50 times · An incompletely descended testis greater with abdominal testis: lying in the abdomen or inguinal approximately 6-10 times greater canal. in inguinal testis · Testicular agenesis Note in 20% of contralateral · `Vanished' testis - vas and vessels descended testes in unilateral are present, but the testis is absent undescent, dysplastic change or replaced by fibrous tissue. shown. Therefore slight increased Probably due to a vascular incidence in malignancy of the accident to the testis, idiopathic `normal' testis. infarction or antenatal torsion. Hormonal treatment Incidence Either HCG or LHRH or both have Approx. 1-3%, (4% in premature been used. Little benefit is gained in births) truly undescended testes. Most Male/female ratio : 6:1 testes, which have descended with 60% right-sided presentation, 30% left- hormonal therapy, have been high sided scrotal or retractile testes. 10-15% bilateral presentation The hernia most frequently comes to INGUINAL HERNIA notice in the first year of life and particularly during the first three A hernia is defined as the protrusion of months. Direct and femoral hernias in a viscus from the cavity in which it children are extremely rare. normally resides. Clinical evidence: Bowel containing Indirect inguinal hernia is a hernia, hernia which emerges through the internal inguinal ring within the cremasteric The symptoms and signs of inguinal fascia extending down the inguinal hernia vary with the type, size, canal for various distances. duration and presence of complications. In the groin of a child, If the hernia remains within the canal, a mass, which comes and goes with it is incomplete. If it extends beyond straining, must be a hernia. At times, the external ring, into the scrotum the it is necessary to base the diagnosis hernia is complete. on a reliable history alone. Symptoms referable to hernia, eg. a feeding Direct inguinal hernia. problem, pain, irritability, or colic, may This is a hernia presenting