Percutaneous ablation of caliceal diverticulum: long-term followup

A caliceal diverticulum is a nonsecretory cavity that serves as a conduit for urinary stasis and its ensuing complications. Indications for intervention and modes of therapy are controversial. We report a series of patients treated with a percutaneous endourological approach to ablation of the diverticular cavity.

A total of 14 patients underwent percutaneous ablation of a caliceal diverticulum for flank pain a mean of 15.5 months in duration. These caliceal diverticula were associated with urinary tract infection in 43% of cases and/or renal calculi in 78%. Mean calculus diameter was 10.2 mm. and mean diverticular diameter was 10.9 mm. An open ended ureteral catheter was placed into the renal pelvis via cystoscopy. Retrograde instillation of radiopaque contrast medium facilitated the localization of a percutaneous renal puncture made directly into the caliceal diverticulum. A flexible tip guide wire was coiled in the diverticulum, and no effort was made to traverse the infundibulum and establish continuity with the remainder of the collecting system. Tract dilation into the caliceal diverticulum was performed, and percutaneous stone fragmentation and extraction were accomplished. The lining of the caliceal diverticulum was electrocauterized using a roller ball electrode. A balloon nephrostomy tube consisting of a Foley catheter with the tip cut off was positioned into the diverticulum. An indwelling ureteral stent was placed and a Foley catheter provided bladder drainage for 48 hours to maintain a low pressure system. The nephrostomy tube was removed after 24 to 48 hours and the ureteral stent was removed after 2 to 4 weeks.

Mean operative time was 162 minutes and mean hospital stay was 2.3 days. Obliteration of the diverticular infundibulum and cavity was documented by contrast radiography (excretory urography or retrograde pyelography), and noncontrast and contrast enhanced computerized tomography, respectively, in all 14 patients. No patients have had recurrent symptoms, calculi or urinary tract infection at a mean 38-month followup.

Percutaneous electrocautery ablation of caliceal diverticula without cannulation or dilation of the diverticular infundibulum represents a safe and effective mode of therapy. Careful patient selection and preparation optimize the efficacy of this technique.