Diagnosis and treatment of a rectal-cutaneous fistula: a rare complication of coccygectomy

Coccygectomy may be indicated for the treatment of debilitating coccygodynia unresponsive to non-operative treatment. Perineal contamination and postoperative wound infection following coccygectomy remains a major concern. We present a rare post-coccygectomy complication of rectal-cutaneous fistula. To our knowledge no such case has been previously described.

A 24-year-old woman presented with recurrent wound infections 1 year after coccygectomy at another institution, which persisted despite two surgical debridements and antibiotic treatment. Wound cultures showed non-specific poly-microbial bacterial growth. MRI scan of the spine and pelvis revealed a sinus track and soft tissue edema with no evidence of abscess or osteomyelitis. Methylene blue injection to the sinus tract confirmed the presence of a rectal-cutaneous fistula. The patient underwent further debridement, fistulectomy and synchronous defunctioning colostomy and resection of the involved colon segment. The wound healed by secondary intention with complete resolution of the infection. Re-anastomosis and closure of the colostomy was performed 6 months later. At 2-year follow-up, the patient had no signs of infection and her initial coccygeal symptoms had improved.

Postoperative infection following coccygectomy remains a major concern. A discharging sinus at the surgical site may suggest the presence of a rectal-cutaneous fistula, which requires a combined approach of spinal and colorectal surgeons. Methylene blue injection to the sinus tract may facilitate the diagnosis of a rectal-cutaneous fistula.