A cloaca is a rare congenital anomaly characterized by lack of embryologic separation of the urethra, vagina, and rectum resulting in a common channel. The severity of the anomaly determines the appropriate approach for repair, which ranges from an introitoplasty with posterior sagittal anorectoplasty to total urogenital mobilization to urogenital separation (UGS) with the possibility of needing a concurrent laparotomy.

Past studies have suggested half of patients with cloacal anomalies will have abnormal postoperative bladder function,^1,2 while greater than 75% of patients have associated upper tract abnormalities.³ This combination of upper and lower tract abnormalities puts these patients at increased risk for renal disease.¹ Unfortunately, due to the rarity of the condition and variation in each clinical presentation and management, the natural history of bladder function following repair has not been rigorously investigated. In the following update, we review the existing knowledge on voiding function following cloaca repair and highlight findings from our prospective single institution study of bladder function following 18 cloacal repairs performed between 2020 and 2021.⁴

The underlying causes of voiding dysfunction in this population may relate to congenital anomalies of the nerves to the bladder, spinal cord abnormalities (roughly 30% have associated anomalies of the spinal cord), and/or hypodevelopment of the pelvic floor muscles. In the largest series of cloaca repairs published by Levitt and Pena, they observed a wide range of function related to the severity of the cloacal anomaly, namely < 30% of patients with a complex cloaca were able to volitionally void; in contrast, upwards of 75% of patients with a moderate cloaca volitionally voided.^5,6 Our understanding of why voiding dysfunction occurs is complicated by the fact that increasingly complex cloaca requires more invasive surgical approaches, which may lead to resultant neuropraxia or peripheral nerve injury that could contribute to voiding dysfunction. Specifically, dissection across the pelvic plexus during UGS may adversely affect bladder function. In our study, all with complex cloaca required assisted bladder emptying (albeit with a median follow-up of less than 2 years) and both urethra and common channel length, as well as surgical approach, were statistically associated with voiding outcomes.⁴ We additionally found that concomitant laparotomy was associated with assisted bladder emptying, which may be a result of cephalad to caudal dissection disrupting the pelvic plexus from a third direction.⁴ Insufflation from a minimally invasive approach may allow for less electrocautery use during dissection; favorable outcomes from a pooled series of 54 laparoscopic UGS cases indicated only 2% required assisted bladder emptying postoperatively, though the majority of the patients in this study had less complex cloaca.⁷

Another pertinent aspect of postoperative evaluation and management of bladder function in cloaca patients includes possible shifts in voiding dysfunction over time which few have reported on. In our study, of the 7 patients who voided without the need for clean intermittent catheterization at 2 to 3 months of follow-up, 1 ended up requiring clean intermittent catheterization at last follow-up. Similarly, among those requiring assisted bladder emptying at 2 to 3 months, 2 were voiding at last follow-up.⁴ We continue to observe that there is a difference between short-term and long-term bladder function, which likely reflects the complexity of factors contributing to overall successful voiding function.

Concomitant spinal anomalies may also contribute to voiding dysfunction. A recent large study of all anorectal malformation patients by Fuchs et al demonstrated an adjusted association between urinary function and spinal cord status.⁸ Our study focusing singularly on patients with cloaca did not find an association between voiding function and radiographic abnormalities of the spine; however, this may be because the abnormalities seen in our cohort were mild (for example, we had no patients with myelomeningocele).⁴ Moreover, many of the spinal cord anomalies seen on MRI in this patient population may not be clinically relevant to voiding function; better defining meaningful spinal cord findings would be useful for functional prognosis.

Although our study is small in the world of research, 18 patients over 20 months is noteworthy for this rare anomaly. In comparison, prior studies have reported on 1 to 3 patients per number of study years. We continue to accrue longitudinal data and are designing an expansion of the data elements. With time, the database will continue to accrue patients and longitudinal data, adding to the existing body of knowledge on voiding dysfunction among cloaca patients. We hope that renal damage and renal transplantation will be reduced with more proactive efforts at bladder management. We also believe urologists have an opportunity to adapt our minimally invasive skillset and our understanding of nerve preservation to potentially improve postop bladder function.