Pressure, Fluid and Anatomical Characteristics of Abdominoscrotal Hydroceles in Infants

Purpose: Abdominoscrotal hydrocele is a poorly understood entity and multiple theories attempt to explain its occurrence. To our knowledge the factors contributing to the formation of abdominoscrotal hydrocele are unknown, as are its cellular, biochemical and hydrostatic properties. We prospectively evaluated abdominoscrotal hydrocele at surgery to define its cause and its effects on the testicle. Materials and Methods: Six patients (9 abdominoscrotal hydroceles) were prospectively evaluated at surgery. Hydrocele volume was recorded as well as simultaneous hydrocele and bladder pressure. Fluid at surgery was sent for biochemical and cellular analysis. Testicular and epididymal abnormalities were noted and testicular length was measured. All abdominoscrotal hydroceles were exteriorized and excised. Processus vaginalis patency was documented at repair. Results: Mean patient age was 7.17 months (range 5 to 12). The mean volume recorded was 212.78 ml (range 80 to 320). Mean corrected hydrocele pressure was 15.44 cm H₂O (range 7 to 28). Mean testicular length was 3.6 cm (range 2.2 to 5.5). All patients had epididymal anomalies and 2 of the 3 unilateral abdominoscrotal hydroceles had abnormal contralateral scrotal findings. In no case was a peritoneal communication identified. Fluid analysis revealed a high protein concentration (mean 4.94 gm/dl), low triglyceride concentration (mean 20.29 mg/dl) and lactate dehydrogenase levels comparable to those in normal serum (mean 99.14 U/l). Cytological analysis revealed a sterile, low cellularity fluid with a macrophage predominance (mean 84.71%). Conclusions: Abdominoscrotal hydrocele occurs as a result of increased intraluminal pressure confined in a proximal closed processus vaginalis. Increased hydrocele pressure allows expansion into the retroperitoneal space through the internal inguinal ring. This increased pressure is associated with testicular elongation and epididymal abnormalities. The exudative fluid is of a noninfectious etiology and it suggests an altered filtration process. To our knowledge the effects on future fertility are unknown.