Retroperitoneal, transmuscular appendico-cutaneous fistula, as a hazard of incomplete appendicectomy

A male child 9 years of age presented with fever, tender swelling in the right flank, with a right paramedian scar. Child had undergone exploratory laparotomy for peritonitis with appendicectomy one year back. Radiological investigations (Ultrasonography and Computed Tomography) revealed retrocecal abscess extending to the psoas muscle, which was drained via flank incision. Intermittent discharge continued through an opening in the flank just above the posterior superior iliac spine. Ultrasonography and CT fistulogram revealed a fistulous communication from skin to the cecum/appendix. Upon second exploration a fistulous communication from the tip of residual appendix (which was left in situ at the initial exploration) was found with multiple adhesions in the terminal ileum, cecum, and ascending colon. Local resection of the cecum and ascending colon was performed with ileocolic anastomosis. Fistulous tract was curetted out. Exploration confirmed the incomplete appendicectomy as a cause of this hazardous condition.