15.1 Cryptorchidism, Hypospadias & PUJO

Cryptorchidism, Hypospadias & PUJO

Paediatric urological conditions require precise timing of surgical interventions to preserve long-term fertility, renal functional capacity, and sexual function. Cryptorchidism, hypospadias, and pelvi-ureteric junction obstruction (PUJO) represent three of the most common congenital anomalies encountered in clinical practice and tested on the Fellow of the European Board of Urology (FEBU) examination. Management protocols adhere strictly to evidence-based joint guidelines from the European Association of Urology (EAU) and the European Society for Paediatric Urology (ESPU).

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Cryptorchidism (Undescended Testis - UDT)

Cryptorchidism, or undescended testis (UDT), is the failure of one or both testes to descend into the scrotal sac. It affects approximately 1% to 3% of full-term male infants and up to 30% of premature boys at birth.

Embryology and Endocrinology of Testicular Descent

Testicular descent occurs through two anatomically and hormonally distinct phases:

1. Transabdominal Phase (Gestational Weeks 8–15):
   • The fetal testis remains in the lower abdomen near the internal inguinal ring.
   • Insulin-like peptide 3 (INSL3), a member of the insulin-relaxin hormone superfamily synthesized by fetal Leydig cells, drives this phase.
   • INSL3 binds to the G-protein-coupled receptor RXFP2 (relaxin/insulin-like family peptide receptor 2, previously termed LGR8) on the gubernaculum testis, causing gubernacular swelling, condensation, and anchoring of the testis to the future internal ring.
   • Müllerian Inhibiting Substance (MIS / AMH) from Sertoli cells regresses the paramesonephric ducts. Androgens play virtually no role in this initial transabdominal migration.
2. Inguinoscrotal Phase (Gestational Weeks 25–35):
   • The testis traverses the inguinal canal and descends across the pubic crest into the scrotum.
   • This phase is strictly androgen-dependent (testosterone synthesized by Leydig cells and locally converted to dihydrotestosterone by 5-alpha reductase).
   • Androgens act on the spinal cord nucleus of the genitofemoral nerve, triggering the release of Calcitonin Gene-Related Peptide (CGRP) from sensory nerve fibers.
   • CGRP induces rhythmic contractions of the gubernacular cord, drawing the testis, enveloped by the processus vaginalis, through the inguinal canal into the scrotum, assisted by transient increases in intra-abdominal pressure.

Natural History and Spontaneous Descent

During the first 3 months of postnatal life (the so-called "mini-puberty" of infancy), a transient surge in the hypothalamic-pituitary-gonadal axis produces spikes in luteinizing hormone (LH), follicle-stimulating hormone (FSH), and serum testosterone. This hormonal surge facilitates spontaneous testicular descent in roughly two-thirds of cryptorchid neonates.

However, spontaneous descent after 3 to 6 months of corrected gestational age is exceptionally rare. A testis that remains undescended at 6 months of age will virtually never descend spontaneously thereafter.

EAU/ESPU Guidelines: Diagnostics and Timing of Orchidopexy

+--------------------------------------------------------------------------------------------------------------+
|                        EAU/ESPU GUIDELINE RECOMMENDATIONS FOR CRYPTORCHIDISM                                 |
|                                                                                                              |
|  Routine Ultrasound / MRI / CT     --> NOT RECOMMENDED (Poor accuracy, fails to alter surgery)               |
|  Hormonal Therapy                 --> No unilateral descent therapy; selected bilateral GnRH for fertility   |
|  Recommended Orchidopexy Window    --> Between 6 and 12 months of age (completed by 18 months)               |
|  Non-Palpable Testis Exploration   --> Examination under anaesthesia, then laparoscopy if still non-palpable |
+--------------------------------------------------------------------------------------------------------------+

• Lack of Utility of Imaging: Routine ultrasonography, CT, and MRI are strongly discouraged. Ultrasound has poor sensitivity (45%) and specificity (78%) for detecting non-palpable intra-abdominal testes or vanishing testes. A negative ultrasound does not eliminate the need for surgical exploration, and a positive ultrasound does not alter the surgical approach.
• Hormonal Therapy: Do not use hCG or GnRH solely to induce descent in unilateral UDT: success is limited and re-ascent occurs. Reported adverse effects include transient virilization and testicular changes, including germ-cell apoptosis. EAU weakly recommends selected GnRH treatment in bilateral UDT to preserve fertility potential; evidence is limited, and this does not replace timely orchidopexy.
• Surgical Timing: Surgical orchidopexy is recommended between 6 and 12 months of age, and must be completed by 18 months at the absolute latest. Progressive histological deterioration begins after 12 months, characterized by the degeneration and loss of dark adult (Ad) spermatogonia, impaired transformation of gonocytes into spermatogonia, and peritubular interstitial fibrosis.

Palpable vs. Non-Palpable Testes

• Palpable Testis (~80%): Typically located in the inguinal canal, external ring, or prescrotal area. Approached via an open inguinal or high scrotal (Bianchi) incision. Key surgical steps include complete mobilization of the spermatic cord, dissection and high ligation of the patent processus vaginalis at the deep inguinal ring, division of cremasteric muscle fibers, and tension-free placement of the testis in a subdartos pouch within the scrotum.
• Non-Palpable Testis (~20%): Re-examine under anaesthesia; if the testis becomes palpable, use the appropriate open approach. Otherwise, diagnostic laparoscopy is the usual exploration. Bilateral non-palpable testes or genital ambiguity require endocrine/genetic evaluation:
  • Vanishing Testis (Nubbin / Agenesis): Spermatic vessels and vas deferens are observed entering the internal inguinal ring or ending blindly in the retroperitoneum with a hypoplastic vascular leash. If vessels end blindly above the internal ring, the diagnosis is confirmed and no further exploration is required (caused by late antenatal in utero spermatic cord torsion). If vessels enter the ring, explore the inguinal canal: excise an atrophic nubbin if found, or perform orchidopexy for a healthy testis. A nubbin may contain hemosiderin and calcification.
  • Intra-Abdominal Testis:
    • If low and mobile near the internal ring, a primary laparoscopic orchidopexy is performed.
    • If high (>2 cm from the internal ring) or tethered on short testicular vessels, a Fowler-Stephens orchidopexy is indicated. This procedure relies on the rich collateral arterial arcade to maintain testicular viability, specifically the artery to the vas deferens (deferential artery) and the cremasteric artery. Fowler-Stephens can be performed as a single-stage or two-stage procedure; the two-stage laparoscopic Fowler-Stephens technique (clipping/transection of the internal spermatic vessels in stage 1, followed 6 months later by mobilization of the testis on its wide peritoneal and deferential pedicle) yields superior testicular survival rates (>85–90%) compared to the single-stage variant.

Long-Term Risks: Subfertility and Neoplasia

• Paternity Rates: Men with unilaterally undescended testes treated in early childhood have paternity rates of ~85–90% (comparable to ~93% in normal controls). However, in men with bilateral cryptorchidism, paternity rates drop precipitously to 33–65%, with severe oligozoospermia or azoospermia.
• Malignancy Risk: Men with cryptorchidism harbor a 2- to 8-fold increased relative risk of developing testicular germ cell tumors (TGCT), most frequently seminoma in untreated intra-abdominal testes. Performing orchidopexy before puberty (and ideally before 12–18 months) significantly reduces the relative risk compared to post-pubertal orchidopexy, and places the testis in an anatomical location amenable to routine monthly digital self-examination. However, orchidopexy does not entirely abolish the baseline elevated neoplastic risk, which is partly rooted in underlying testicular dysgenesis syndrome (TDS).

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Hypospadias

Hypospadias is a congenital hypoplasia of the ventral aspect of the penis affecting roughly 1 in 200 to 1 in 300 live male births.

Clinical Presentation and The Classic Triad

Hypospadias is defined by a triad of anatomical features resulting from arrested ventral embryogenesis:

1. Ectopic Ventral Urethral Meatus: Abnormally positioned meatus located anywhere from the perineum to the glans penis due to incomplete fusion of the paired genital/urethral folds.
2. Ventral Penile Curvature (Chordee): Angulation of the penile shaft during erection, caused by superficial skin tethering, fibrosis of Buck's and dartos fascia, or intrinsic ventral corporeal disproportion.
3. Dorsal Hooded Prepuce: Deficient ventral preputial skin with redundant dorsal foreskin, caused by premature termination of the ventral preputial development.

Anatomical Classification

Hypospadias is classified by the location of the ectopic meatus after the correction of any associated chordee:

• Distal (Anterior) Hypospadias (65–70%): Glanular, coronal, and subcoronal.
• Mid-shaft (Middle) Hypospadias (10–15%): Distal penile, mid-shaft, and proximal penile.
• Proximal (Posterior) Hypospadias (15–20%): Penoscrotal, scrotal, and perineal.

Proximal hypospadias with concomitant cryptorchidism or bifid scrotum represents a phenotypic marker of a potential Disorder of Sex Development (DSD). Such presentations mandate urgent endocrine, biochemical, and genetic evaluation (karyotyping, pelvic ultrasound to evaluate Müllerian remnants, and serum 17-hydroxyprogesterone to exclude congenital adrenal hyperplasia).

Surgical Timing and Reconstructive Techniques

The recommended window for hypospadias repair is between 6 and 18 months of age, when penile size allows delicate microsurgery while minimizing psychological and body-image trauma prior to genital awareness.

1. Orthoplasty (Correction of Chordee):
   • Following degloving of the penile shaft to the penoscrotal junction, an artificial erection test (Gittes test) is performed with normal saline injected into the corpora cavernosa.
   • Reassess curvature after degloving and release of tethering tissue. Residual curvature ≥ 30° generally warrants correction; dorsal plication is one option for suitable lesser deformity.
   • Severe chordee (>30°) often requires division of the hypoplastic urethral plate and ventral corporeal grafting.
2. Urethroplasty Techniques:
   • Tubularized Incised Plate (TIP / Snodgrass Repair): The gold standard for distal and selected mid-shaft hypospadias with a favorable urethral plate. A longitudinal relaxing incision along the midline of the urethral plate widens the plate without transecting it, enabling tubularization into a calibrated neo-urethra over an 8–10 Fr stent. A vascularized dartos flap is interposed as a barrier layer.
   • Mathieu Repair (Perimeatal-Based Flap): Utilized for distal coronal hypospadias when the urethral plate is shallow or cleft. A proximal ventral penile skin flap is flipped forward like a book page and sutured to the urethral plate edges.
   • Onlay Island Flap: A vascularized pedicled flap harvested from the inner preputial mucosa and transposed ventrally to bridge an intact but narrow urethral plate in mid-shaft defects.
   • Two-Stage Bracka Repair: Indicated for severe proximal hypospadias with severe chordee requiring urethral plate transection. In Stage 1, the chordee is fully corrected, the plate is divided, and a free graft (inner prepuce or buccal mucosa) is quilted onto the ventral tunica albuginea. In Stage 2 (performed 6–12 months later), the healed and revascularized graft is tubularized into a neo-urethra.

Postoperative Complications

• Urethrocutaneous Fistula (5–15%): The most common complication, presenting as split streaming or leakage of urine from the ventral shaft. Prevented by interposition of a well-vascularized tunica vaginalis or dorsal subcutaneous dartos barrier flap over the neourethral suture line.
• Meatal Stenosis: Narrowing of the neo-meatus, presenting with high-pressure voiding and spraying; prevented by avoiding excessively distal tubularization of the glans wings.
• Urethral Diverticulum: Dilation of the neo-urethra caused by distal functional obstruction (meatal stenosis) or lack of mechanical tissue backing.

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Pelvi-Ureteric Junction Obstruction (PUJO)

Pelvi-ureteric junction obstruction is the impaired flow of urine from the renal pelvis into the proximal ureter, leading to progressive pelvicalyceal dilation and subsequent parenchymal atrophy.

Pathophysiological Etiology

• Intrinsic Obstruction (Most Common): Presence of an aperistaltic, adynamic, fibrotic segment of the proximal ureter with disrupted longitudinal and circular smooth muscle architecture and excessive collagen deposition between muscle bundles. The aperistaltic segment fails to propagate a peristaltic coapting contraction wave.
• Extrinsic Obstruction: Compression of the PUJ or proximal ureter by crossing lower-pole renal vessels. Typically presents in older children, adolescents, or young adults, frequently exacerbated by intermittent diuresis.

Clinical Presentation

• Antenatal Hydronephrosis: Vast majority discovered during routine maternal fetal ultrasound; graded using the Society for Fetal Urology (SFU) system (Grades 0–IV) or the Urinary Tract Dilation (UTD) risk categories.
• Postnatal / Late Presentation: Abdominal mass in neonates; in older children, classic Dietl crisis—intermittent, episodic, agonizing flank or abdominal pain accompanied by nausea and vomiting, triggered by high fluid intake or caffeinated beverages that induce a diuresis surge overwhelming pelvi-ureteric capacity.

Diagnostic Workup: Diuretic Renography

Routine postnatal ultrasonography follows the first 48 hours, when oliguria may underestimate dilatation. Severe bilateral dilatation, a solitary kidney or oligohydramnios warrants immediate postnatal ultrasound. The definitive functional imaging modality is diuretic renography using 99mTc-Mercaptoacetyltriglycine (99mTc-MAG3) with furosemide administration (using a standardized protocol such as F+20):

• Split Renal Function (SRF): Quantifies the percentage of global renal clearance contributed by each kidney (normal: 45%–55% per kidney).
• Drainage Clearance Half-Time ($T_{1/2}$):
  • $T_{1/2} < 10 \text{ min}$: Normal, non-obstructed drainage washout.
  • $T_{1/2} = 10–20 \text{ min}$: Equivocal / indeterminate curve.
  • $T_{1/2} > 20 \text{ min}$: Delayed washout, raising concern for obstruction. Interpret the whole curve, cortical transit, hydration, bladder emptying and postvoid/gravity-assisted drainage; half-time alone is not diagnostic.

Renogram Clearance Patterns:
Activity
  ^          /\  Normal (Washout T1/2 < 10 min)
  |         /  \
  |        /    \_______________________
  |       /          /\   Equivocal (T1/2 10-20 min)
  |      /          /  \_____________
  |     /          /                 Delayed drainage (T1/2 > 20 min; assess full study)
  |    /          /  /---------------------------------------------------------
  |   /          /  /   <-- Furosemide injection at 20 min
  +----------------------------------------------------------------------------> Time (min)

Indications for Surgical Pyeloplasty

Asymptomatic neonates with stable non-obstructed hydronephrosis and normal function are managed conservatively with serial ultrasound and renography. Surgical intervention is indicated under the following EAU/ESPU criteria:

1. Impaired split renal function SRF < 40%, interpreted with drainage, ultrasound findings and clinical course.
2. A documented fall in split renal function of > 10 percentage points on serial diuretic renograms.
3. Progressive worsening of anteroposterior pelvic diameter (APPD) or development of parenchymal thinning on serial ultrasounds.
4. Symptomatic presentations (recurrent Dietl crises, breakthrough pyelonephritis, or stone formation secondary to urinary stasis).

Surgical Technique: Anderson-Hynes Dismembered Pyeloplasty

The Anderson-Hynes dismembered pyeloplasty remains the gold standard operation, performed via open, pure laparoscopic, or robot-assisted laparoscopic approaches:

• Dismemberment: Complete transection of the PUJ from the renal pelvis.
• Vascular Transposition: If an extrinsic crossing lower pole polar vessel is present, the ureter and pelvis are fully mobilized and repositioned anterior to the crossing vessels to eliminate mechanical compression.
• Excision: Complete resection of the intrinsic stenotic, adynamic segment and reduction/tailoring of the redundant, flaccid renal pelvis.
• Spatulation & Reconstruction: Wide spatulation of the healthy, lateral border of the upper ureter followed by a tension-free, watertight, spatulated pelvi-ureteric anastomosis using fine absorbable sutures (6-0 or 5-0 PDS/polydioxanone) placed over an internal Double-J ureteric stent or trans-anastomotic nephrostomy tube.

Paediatric Anomalies: Diagnostic, Timing & Surgical Management Comparison

Childhood Renal and Adrenal Tumours

A solid abdominal mass in a child needs prompt specialist paediatric-oncology assessment. Wilms tumour (nephroblastoma) is a major childhood renal malignancy; neuroblastoma commonly arises from adrenal or sympathetic tissue. Do not transfer an adult renal-mass algorithm to every childhood mass.

For suspected Wilms tumour, evaluate the renal origin, opposite kidney, venous extension and distant disease with appropriate imaging. Ultrasound is often initial; CT/MRI and chest imaging complete staging as directed by the specialist protocol. Record blood pressure, renal function and syndromic features. Aniridia, genitourinary anomalies and overgrowth can indicate predisposition.

Treatment is protocol-specific. European SIOP pathways usually use preoperative chemotherapy for a typical Wilms presentation, whereas COG commonly uses initial nephrectomy for a suitable unilateral resectable tumour. Bilateral disease requires a renal-preservation strategy. Biopsy, surgery and staging must follow the chosen protocol: an unplanned biopsy or tumour spill can affect subsequent management. This distinction prevents an apparently straightforward answer from being applied in the wrong setting.

For suspected neuroblastoma, assess urinary VMA/HVA catecholamine metabolites, cross-sectional imaging and MIBG imaging when appropriate; tissue and tumour biology guide risk classification. Treatment varies with age, stage and biology: selected low-risk cases may be observed or treated surgically, whereas high-risk disease requires multimodal specialist treatment. New neurological deficits suggesting spinal cord compression need urgent assessment and treatment.

Worked decision: A young child has a suprarenal mass, raised urinary catecholamine metabolites and bone pain. Neuroblastoma is a leading concern; arrange paediatric-oncology staging rather than immediate routine nephrectomy for presumed Wilms tumour.

Primary references: NCI PDQ childhood kidney tumours, neuroblastoma and patient neuroblastoma overview.