A vasocutaneous fistula developed 3 years following vasectomy at a site containing retained silk ligature and chronic inflammation.
The case involved a 43-year-old male patient presenting with a 2-month history of persistent whitish discharge from the root of the left hemiscrotum. He had undergone bilateral no-scalpel vasectomy 3 years earlier, in which the proximal vasal stump on each side was ligated with nonabsorbable silk suture, monopolar electrocautery was applied, and both vasal ends were ligated. His postoperative recovery was uneventful, although postvasectomy semen analysis had not been performed.
Researchers assessed the persistent sinus using clinical examination, microscopy of the discharge, ultrasonography, surgical exploration, and histopathologic examination, with the intent to establish whether the cutaneous tract communicated with the vas deferens and to characterize findings surrounding the previous vasectomy site. Treatment consisted of surgical excision, with follow-up for symptom resolution and recurrence.
Examination showed a 2-mm sinus opening at the root of the left hemiscrotum, with a thickened left vas deferens palpable immediately beneath it. Microscopy of the discharge demonstrated occasional spermatozoa with inflammatory cells. Ultrasonography showed a hypoechoic tract extending from the cutaneous opening toward the previous vasectomy site, with adjacent thickening consistent with chronic inflammatory change. Together, the persistent sinus, spermatozoa in the discharge, and imaging findings raised suspicion for a vasocutaneous fistula.
Surgical exploration demonstrated a continuous epithelialized fistulous tract extending from the cutaneous opening to the previously ligated proximal vasal stump. At the point of communication, a retained black-braided suture consistent with the silk ligature documented during the original vasectomy was embedded within dense fibrotic tissue. The fistulous tract and involved vasal segment were excised en bloc, and the remaining healthy proximal vas was religated with absorbable suture.
Histopathologic examination demonstrated chronic inflammatory infiltrates composed of lymphocytes and plasma cells. An adjacent fragment of vas deferens was also identified. The findings supported the operative diagnosis.
Postsurgery, the wound had healed satisfactorily at 1 week. At 1 and 3 months, the patient remained asymptomatic, with complete resolution of the discharge and no clinical evidence of recurrence.
No component of the evaluation independently established the diagnosis. Histopathology corroborated the operative findings but did not establish the fistulous communication, while spermatozoa in the sinus discharge supported communication with the vas deferens but could not localize the anatomical pathway. The diagnosis instead rested on concordant clinical, microscopic, imaging, operative, and histopathologic evidence.
Pathogenesis of delayed vasocutaneous fistula remains uncertain and may be multifactorial. These findings supported the hypothesis that persistent suture-associated inflammation may have contributed to progressive epithelialization and fistula formation during the 3-year interval following vasectomy but did not establish causality.
The report was limited by its single-case design. The original ultrasound images were unavailable for independent review, and although microscopy had demonstrated occasional spermatozoa in the discharge, a contemporaneous photomicrograph was also unavailable. The association between retained suture material, chronic inflammation, and fistula formation could not establish causality from a single observation.
The case suggested that delayed vasocutaneous fistula may warrant consideration in patients with persistent scrotal sinus discharge following vasectomy, particularly when spermatozoa are identified in the discharge. The findings also underscored the researchers’ emphasis on combining clinical, laboratory, operative, and histopathologic evidence rather than relying on a single diagnostic modality.
“This case demonstrates that diagnosis is best established through integration of clinical findings, sperm microscopy, supportive imaging, operative confirmation, and histopathologic examination rather than reliance on any single modality,” wrote lead study author Senthil Kumar Thiagarajan, of the Department of Urology at SRM Medical College Hospital and Research Centre at the SRM Institute of Science and Technology in India, and colleagues.
The study authors reported no conflicts of interest.
Source: BMC Urology