Patent urachus and bladder outflow obstruction\u2014chance or consequence? A study of a cohort of patients with complete patent urachus presenting to a tertiary urological center and a review of literature

Heba Taher,Abraham Cherian,Sharmila Ramnarine,Imran Mushtaq,Naima Smeulders,Peter Cuckow,Divyesh Desai

doi:10.1186/s43159-020-00069-1

Heba Taher, Abraham Cherian + Show 5 more

Open Access

https://doi.org/10.1186/s43159-020-00069-1

Copy DOI

Abstract

BackgroundTo explore the association between patent urachus and bladder outflow obstruction (BOO). A retrospective review of patient records over a 35-year period (1983–2018) with complete patent urachus was performed. Antenatal ultrasound findings were noted, and postnatal investigations included ultrasound (US), micturating cystourethrogram (MCUG), functional nuclear medicine scans (MAG3, DTPA, and DMSA), and serum creatinine. Associated anomalies and management in all patients were analyzed.ResultsSixty-six patients with all types of urachal remnants were identified of whom only 16 had a patent urachus. All presented clinically with a discharging umbilicus, 10/16 confirmed on MCUG and 4 had umbilical cord cysts on antenatal US. Twenty-five percent had associated bladder outlet obstruction (BOO): etiologies included atresia of posterior urethra, congenital urethral hypoplasia, urethral atresia with prune belly syndrome, and sacrococcygeal teratoma. Vesicoureteral reflux (VUR) was confirmed in 37%, and four of them had bladder outlet obstruction (BOO).ConclusionWith patent urachus, bladder outflow obstruction occurs in the minority. Based on our findings, we commend US and cystogram to document VUR. The isolated PU should be treated nonoperatively up to a year of age. Renal function should be checked with the finding of VUR. The etiopathogenesis of the condition remains uncertain.

Highlights

To explore the association between patent urachus and bladder outflow obstruction (BOO)
Does obstruction cause persistence of the urachal channel? Bureau and Bolduc tried to answer this question in their case report of patent urachus and posterior urethral valves and referred to the article by Ross et al which was a prospective study and looked at the prevalence of first trimester cysts, and among 29 cysts found in 859 women screened, and only one was associated with obstructive uropathy [4]
Postnatal US was the most common radiological investigation 15 patients (93.8%) followed by micturating cystourethrogram (MCUG) 10 patients before surgery (62.5%) and one performed after the surgery of the patent urachus for a not related subject, DMSA 6 patients (37.5%), MAG3/DTPA in four patients (25%), and CT renogram in one patient

Summary

Introduction

To explore the association between patent urachus and bladder outflow obstruction (BOO). Patent urachus (PU) is a rarity, the quoted incidence in literature being quite variable ranging between 1 and 2.5/100,000 and 1/7610 [1,2,3]. It has only been recognized and diagnosed prenatally since 1988 [1]. Bureau and Bolduc tried to answer this question in their case report of patent urachus and posterior urethral valves and referred to the article by Ross et al which was a prospective study and looked at the prevalence of first trimester cysts, and among 29 cysts found in 859 women screened, and only one was associated with obstructive uropathy [4]. The association of bladder outflow obstruction (BOO) and the persistence of urachus have been referred to in published literature evidence is lacking to suggest there is a strong association; it is quite a rare event in obstructive uropathy [5, 6].

Methods

Results

Discussion

Conclusion