Hydrocele

Epidemiology

• Affects an estimated 1% of adult men
• Over 80% of newborn boys have a patent processus vaginalis, but most close spontaneously within 18 months of age
• Secondary hydroceles usually occur in men >40 years

Embryology & Pathophysiology

Classification (Types)

Figure: (a) Vaginal hydrocele; (b) Infantile hydrocele; (c) Congenital/communicating hydrocele; (d) Hydrocele of the cord. Red circles indicate the level of processus vaginalis closure.

Secondary Causes

• Infection / epididymo-orchitis
• Testicular torsion
• Testicular neoplasm (important to exclude - do not puncture if tumour suspected due to risk of malignant needle-track implantation)
• Trauma
• Radiotherapy
• Filariasis (Wuchereria bancrofti - accounts for up to 80% of hydroceles in tropical countries)
• Post-varicocelectomy (due to lymphatic obstruction; incidence 3-33%, average ~7%)

Clinical Features

Examination (upright and supine)

1. Can you get above the swelling? - If no, consider inguinal hernia entering the scrotum.
2. Is the testis/epididymis palpable? - A hydrocele encloses both structures so they may be impalpable, but you can get "above" the swelling to palpate a normal spermatic cord.
3. Does it transilluminate? - Hydroceles are typically translucent and transilluminate brightly.

Presentation

• Usually painless - may reach significant size before presentation
• Congenital hydrocele may be intermittent (fluid drains into peritoneum when lying down)
• Be wary of an acute hydrocele in a young man - may be a testicular tumour
• Hydrocele of the cord: smooth oval swelling above testis near spermatic cord; moves downwards and becomes less mobile when testis is pulled downwards
• Hydrocele of the canal of Nuck: female equivalent; cyst along round ligament, partially within inguinal canal
• If bilateral congenital hydroceles - check for ascites

Clinical Image & Ultrasound

Figure: Right-sided hydrocele (a) clinical appearance, (b) scrotal ultrasound showing anechoic fluid collection surrounding the testis (5.31 cm). (Courtesy of Dr Davide Prezzi)

Investigations

• Scrotal ultrasound - valuable adjunct in nearly all cases; assesses the testis itself for tumour or other pathology, especially when testis/epididymis are impalpable
• Tumour markers (AFP, beta-hCG, LDH) if malignancy suspected

Treatment

1. Conservative

• Small, asymptomatic hydroceles do not require treatment
• Congenital hydroceles frequently resolve spontaneously by 18 months

2. Surgical (main treatment)

• Suitable for thin-walled sacs
• Interrupted absorbable sutures plicate the redundant tunica vaginalis, bunching it at its testicular attachment
• Minimal dissection; reduced risk of haematoma

Figure: Lord's operation - plication of the tunica vaginalis using interrupted absorbable sutures

• Hydrocele sac is opened and everted behind the testis, then anchored with sutures (testis placed in a fascial pouch)
• Care needed to control bleeding from cut edge to avoid scrotal haematoma
• Overrunning stitches at cut edge reduce this risk

• For thick-walled acquired hydroceles
• Established acquired hydroceles often have thick walls requiring partial or complete sac excision

3. Aspiration ± Sclerotherapy

• Fluid always reaccumulates within a week or so after simple aspiration
• Suitable only for men unfit for surgery
• Risk: bleeding into sac causing haematocele
• Sclerosant injection (e.g. tetracycline, polidocanol) can be effective but is painful; long-term data exist for polidocanol

Special Notes

Post-varicocelectomy Hydrocele

• Average incidence ~7% (range 3-33%) after non-microscopic varicocelectomy
• Caused by lymphatic obstruction
• At least half grow large enough to warrant surgical excision
• Microsurgical technique with magnification to preserve lymphatics almost eliminates this risk

Filarial Hydrocele / Chylocele

• Up to 80% of hydroceles in tropical countries (W. bancrofti endemic areas)
• Follow repeated filarial epididymo-orchitis attacks
• Fluid may contain liquid fat (chyle) from ruptured lymphatic varix - cholesterol-rich
• Dense adhesions in longstanding cases
• Treatment: rest and aspiration; chronic cases require excision of the sac

After Hernia Repair

• If a distal sac or hydrocele is present during inguinal hernia repair, it must be opened widely, not tied off - tying creates a closed space where a new hydrocele can form

Key Points Summary