“Perineal Canal”: A Rare Anorectal Malformation of Variable Complexity

Abstract

Perineal canal (PC) is a fistulous tract that communicates the anus with the vulvar vestibule. Our aim is to show the variable spectrum of complexity of this caudal malformation. Patient 1 had a single urogenital orifice and a normal anus. After sigmoidostomy, a uterovaginal duplication was discovered upon opening the canal that was repaired at puberty. Patient 2 had a single urogenital orifice, a huge dilatation of a single vagina and an apparently normal anus. During perineal operation without diversion, the true anus was found which opened into the PC. Patient 3 had a single urogenital orifice, a uterovaginal duplication and an apparently patent anus. After colonic diversion, the PC was taken down revealing a normal urethral opening, the absence of an anus and a high rectovaginal fistula at the intervaginal wall. A posterior sagittal approach allowed extensive mobilization of the fistula and the rectum, fashioning of a single vagina and positioning of the rectum within the striated muscle complex. The cosmetic results were satisfactory. Patients 1 and 2 have normal continence and a near-normal perineal anatomy. Patient 3 is too young to assess continence. 1) Perineal canal is a malformation that may involve the genitourinary system as well as the rectum and perineum. This developmental disturbance of the caudal end is profound as judged by the vaginal duplication and the nearly cloacal pattern of some cases. 2) Repair may be as challenging as that of a regular cloaca requiring an individualized approach.