Cloacal Malformations: Technical Aspects of the Reconstruction and Factors Which Predict Surgical Complexity

Abstract

Cloacal malformations are rare anomalies which occur in one in 50,000 live births. Anatomically these anomalies are defined by the presence of a single perineal orifice. There is however a substantial range in their complexity. Defining these differences is key to surgical planning and timely referral of selected cases to centers with the capabilities to manage the most challenging cases. Traditionally the common channel length as measured during cysto-vaginoscopy has been used to differentiate between patients that can be repaired with a reproducible operation and those requiring a more complex repair. The quality and range of imaging available has advanced and thus a more detailed anatomic picture is now possible to help with pre-operative planning. Cross sectional imaging with 3D reconstruction has enhanced the understanding of the anatomic variations in these patients. In addition, the sacral ratio, previously thought to only have an influence on long term continence predictions, has been shown to not only forecast the presence of urological anomalies, but also the complexity of the malformation. In principle, cloacal malformations have two major components to the reconstruction. First, the rectum needs to be separated from the urogenital tract and second, the urogenital sinus needs to be managed to create a urethral orifice and vaginal introitus. The length of the urethra has been shown to be vital in deciding between the two main surgical maneuvers; a total urogenital mobilization (TUM) and a urogenital separation. The technical demands of a urogenital separation are significant and discussed here in detail. The need for vaginal replacement adds further complexity to the care of these patients and has also been shown to be related to the length of the urethra. Predicting complexity in an accurate and non-invasive way will facilitate the care of the most complex cloacal malformations and improve outcomes.

Keywords: anorectal malformation; cloaca; congenital; incontinence; surgical teaching.

Figure 1

3D Reconstructed Cloacagram with bladder marked in magenta, vaginas in pink, bowel in tan, and common channel in blue. Reproduced with permission from © Center for Colorectal and Pelvic Reconstruction at Nationwide Childrens Hospital.

Figure 2

A 2D Cloagagram with the urethra marked in yellow and the common channel marked with green. This demonstrates a common channel of 2.5 cm and a urethra of 2 cm. The operative photo shows the splitting of the common channel during the Total Urogenital Mobilization (TUM), leaving only the urethra (green) to be sutured to the perineum. Reproduced with permission from © Center for Colorectal and Pelvic Reconstruction at Nationwide Childrens Hospital.

Figure 3

The posterior sagittal view with the rectum, vagina, and common channel dissected out but not opened. Reproduced with permission from © Center for Colorectal and Pelvic Reconstruction at Nationwide Childrens Hospital.

Figure 4

The rectum mobilized free from the vagina and the vagina opened. There are sutures on the edge of the vagina above the urethro-vaginal fistula in preparation for separation. The urethral catheter is visible. Reproduced with permission from © Center for Colorectal and Pelvic Reconstruction at Nationwide Childrens Hospital.

Figure 5

The rectum is mobilized and the vagina is being mobilized off the common channel, urethra, and bladder neck. A urethral catheter visible. Reproduced with permission from © Center for Colorectal and Pelvic Reconstruction at Nationwide Childrens Hospital.

Figure 6

On the left, is the fully separated rectum, vagina, and urological tract with common channel kept as urethra. The top right picture shows the urethra repaired and the repair covered with SIS. The bottom right picture shows the repair being covered with an ischiorectal fat pad. Reproduced with permission from © Center for Colorectal and Pelvic Reconstruction at Nationwide Childrens Hospital.