Non-acute abdominal and urological problems in children
Introduction
The acute conditions described in Chapter 50 are largely congenital disorders presenting in the neonatal period, whereas non-acute conditions present across the whole of childhood. The most common referrals are hernias and associated problems, abnormalities of testicular descent and foreskin problems. Less often, surgeons manage chronic or recurrent abdominal pain, chronic constipation, rectal bleeding, an abdominal mass or rectal prolapse. Many children present first to a paediatrician and are referred to a paediatric or general surgeon.
Problems with the groin and male genitalia
Hernias and associated problems
The processus vaginalis normally closes spontaneously soon after birth. Persistence causes three common problems in boys: patent processus vaginalis (PPV), hydrocoele and inguinal hernia, which may all present as inguinal or scrotal swellings, usually in babies and pre-school children (Fig. 51.1).
Hydrocoele
Non-communicating hydrocoeles are mostly seen in neonates and young babies (Fig. 51.2). The usual type is a scrotal swelling resulting from incomplete reabsorption of fluid within the tunica vaginalis after closure of the processus vaginalis. There may be a separate hernia present. These so-called ‘primary hydrocoeles’ sometimes appear following a viral illness. Rarely, a secondary hydrocoele results from testicular trauma or torsion, epididymitis or a testicular tumour.
Inguinal hernia
Inguinal hernias in children arise because the processus vaginalis fails to close after testicular descent; they are true congenital abnormalities. Anatomically, they are the same as indirect inguinal hernias in adults (see Ch. 32) but without a substantial abdominal wall defect. The incidence in infants ranges from 1% to 4.4%, with a male preponderance of 4 : 1; 98% are indirect. The incidence in premature neonates is 30% and the overall incidence is increasing in line with the number of premature neonates surviving.
Inguinal hernias may become acutely irreducible and painful, sometimes with obstructive symptoms such as vomiting (see Ch. 50). In these cases, there is a real risk of testicular necrosis and/or strangulation of the hernia contents, e.g. bowel or ovary (see Fig. 50.10). In known hernias, parents should be instructed to bring the child to hospital for urgent herniotomy if it becomes incarcerated to prevent these risks.
The standard operation is inguinal herniotomy, a common general paediatric operation. In babies and children, this involves separating the peritoneal sac from the cord (or round ligament), ligating it at the external ring and removing it. There is rarely any need to perform a repair (herniorrhaphy); see Figure 51.3. The incidence of an undiagnosed contralateral hernia in boys is between 1 : 8 and 1 : 13 but contralateral groin exploration is no longer performed in the UK.
Umbilical hernia
Many newborn babies have umbilical hernias, particularly if premature (Fig. 51.4), but the defect usually cicatrises and resolves during the first 2 years of life; they are common in Afro-Caribbean babies and can run strongly in families. Small umbilical hernias may undergo spontaneous closure up to 4–5 years of age. Rarely, they become incarcerated or strangulate. Indications for repair are symptoms, persistence beyond 5 years and perhaps social pressure to prevent teasing. The size of the abdominal wall defect should be determined; large defects (> 2 cm) are less likely to close spontaneously, although very large swellings may have small abdominal wall defects likely to close spontaneously. It is important to differentiate umbilical hernias from epigastric hernias which do not close spontaneously. At operation, a small subumbilical ‘smile’ incision allows emptying and ligation of the peritoneal sac and placement of a few absorbable repair sutures. The umbilical skin is usually sutured to the repair to restore its normal recessed appearance.
Testicular maldescent
The normal mechanism of descent is not fully understood but does occur in two phases. Migration from the gonadal ridge to the internal inguinal ring depends on shortening of the gubernaculum, driven by Müllerian inhibiting substance (MIS). This phase is not androgen-dependent, unlike the second phase of descent from internal ring to scrotum. A maldescended testis may arrest anywhere on its path of descent. About 20% lie within the abdomen but 80% lie in the groin area, in the inguinal canal or usually outside the external ring in the superficial inguinal pouch or upper scrotum. In addition, 1% of testes are deflected and lie ectopically. Second phase maldescent can result from the testis being structurally abnormal, rather than any abnormality being caused by maldescent. The common sites of incomplete descent or ectopia are shown in Figure 51.5.
• Neoplasia—carcinoma-in-situ is present in 2% of undescended testes and maldescent has up to 10 times the normal risk of testicular malignancy (although the risk is still small); if surgical correction is done sufficiently early, it may reduce this risk but the principal purpose is for the patient to perform self-examination and report lumps in later life. Long-term follow-up after orchidopexy is desirable. Seminomas are the most common tumour (60%) and usually present between 20 and 40 years of age. It is important to inform the parents of the increased risk of malignancy and to reinforce the importance of testicular self-examination in adult life
• Subfertility—maldescended testes exhibit incomplete maturation of seminiferous tubules, leading to sperm abnormal in quantity, form or motility. This may be by virtue of being at normal body temperature instead of at least 1° cooler in the scrotum. Early orchidopexy helps maturation of the tubules and spermatogenesis, ideally between 6 and 12 months of age. Patients with unilateral maldescent have more subfertility and lower sperm counts. Those with bilateral intra-abdominal testes have the most subfertility
• Torsion—incompletely descended testes are abnormally mobile. Torsion of the testis, actually torsion of the spermatic cord, causes strangulation of blood supply, testicular necrosis and later atrophy. Torsion sometimes occurs during intrauterine life but may happen at any age. Intrauterine or neonatal torsion occurs proximal to the reflection of the tunica vaginalis (i.e. extravaginal). Infarction results in atrophy and loss of the testis so that at laparoscopy, only blind-ending testicular vessels and vas deferens are found. The condition occurs bilaterally in up to 30%
• Psychological—normal genitalia are important in the development of body image, gender acceptance and personality in adolescence. Orchidopexy at an early age provides reassurance to the child and parents
Boys should be examined regularly from birth right through school age to identify maldescent and allow timely orchidopexy. Periodic examination is needed because unequivocally descended testes can later ascend and parents and doctors should be alert to this possibility. There may be a fibrous band within the processus vaginalis preventing elongation of testicular vessels as the boy grows. The resulting ‘stationary’ testis appears to ascend, and no longer comes comfortably into the scrotum.