Calyceal diverticula in children: laparoscopic marsupialization is the optimal intervention

Calyceal diverticula (CD) are abnormally dilated calyces caused by a narrowed infundibulum. Although rare, with incidence rates previously reported between 0.21% and 0.45%, CD pose diagnostic dilemmas in children as they mimic other cystic lesions of the kidney with different etiologies. Calyceal diverticula can become symptomatic if they become a locus for infections and stone formation, and the optimal treatment strategy is currently undefined.

The aim of the study is to present a large series of consecutive cases of pediatric CD and investigate the authors' hypothesis that CDs are more common than previously reported, size of the lesion drives intervention, and laparoscopic ablation is the most effective intervention.

The authors conducted an observational case-control survey by reviewing all cases of pediatric CD through a prospectively maintained database of renal cystic lesions at their institution between 2012 and 2018. They analyzed the clinical and radiological presentation and description of symptoms with particular emphasis on the outcomes of ureteroscopic or laparoscopic surgical interventions.

Of 757 renal cysts evaluated in the pediatric urology clinics at the authors' institution, there were 43 (5%) cases of CD confirmed by cross-sectional imaging or retrograde pyelogram. The median age was 12 years. There was a female preponderance (67%), and 14% were bilateral. Twenty-five of 43 children underwent surgery (58%). On multivariate analysis, the size/complexity of the cyst (odds ratio = 2.13, 1.02 to 4.4, P = 0.04) and the presence of pain (5.931, 1.36 to 25.87, P = 0.018) were found to correlate with the need for intervention. Ureteroscopic intervention (i.e., balloon dilatation, laser incision, or diathermy incision) was the most used index procedure (17/25), followed by laparoscopic ablation (6/25), with success rates of 40% and 100%, respectively (P = 0.01). Complications in either of the approaches were usually mild and similar (P = 0.63). The majority of ureteroscopic interventions required multiple sessions (11/17, 65%, median = 2 major procedures) to achieve resolution, whereas none in the laparoscopic group required a second procedure. There were a total of 30 ureteroscopic and 8 laparoscopic approaches.

The authors demonstrate that CD comprise at least 5% of cystic lesions and that CD size and pain at presentation predict intervention in 60% of children diagnosed at their institution. Laparoscopic ablation is the optimal treatment and has significantly higher success rates than the ureteroscopic approach.