Percutaneous Management of Stone Containing Calyceal Diverticula: Associated Factors and Outcomes

We evaluated the outcomes of percutaneous treatment and metabolic evaluation of calyceal diverticula with associated stones.

We retrospectively identified 51 patients with a calyceal diverticulum in our prospectively maintained percutaneous nephrolithotomy database. Patients with complete data were separated into 14 with stones isolated to the diverticulum and 15 with renal stones in and outside the diverticulum. A total of 571 patients with renal stones but no diverticulum were used for comparison. Statistical differences were assessed using the chi-square test and the t-test.

Patients with stones isolated to the diverticulum were younger (44 vs 54 years, p = 0.024), had a lower body mass index (23.2 vs 27 kg/m², p = 0.032) and were more often female (71% vs 44%, p = 0.046) compared to patients with renal stones but no diverticulum. Calyceal diverticula were anterior in 19 of 29 cases and in the upper pole in 15. Average diverticular size was 2.5 cm with a 1.5 cm stone burden. Percutaneous treatment was successful in 96% of patients with a 4% complication rate. The diverticular neck was dilated in 22 of 51 patients (43%). During 5-year followup in the 51 patients there was 1 stone recurrence, which was managed by ureteroscopy, while 46 and 5 patients showed complete absence and reduction of the diverticulum, respectively. Of the calyceal diverticular stones 82% contained calcium phosphate compared to only 33% in patients with renal stones but no diverticulum. All patients with a diverticulum had at least 1 metabolic derangement.

Percutaneous treatment of calyceal diverticula is safe and effective regardless of size or location, including anterior diverticula. Infundibular neck dilation does not appear to be necessary. There are metabolic abnormalities in a significant proportion of patients with a calyceal diverticulum.