Percutaneous ablation of caliceal diverticulum: Long-term followup

Purpose: A caliceal diverticulum is a nonsecretory cavity that serves as a conduit for urinary stasis and its ensuing complications. Indications for i ntervention and modes of therapy are controversial. We report a series of p atients treated with a percutaneous endourological approach to ablation of the diverticular cavity. Materials and Methods: A total of 14 patients underwent percutaneous ablati on of a caliceal diverticulum for flank pain a mean of 15.5 months in durat ion. These caliceal diverticula were associated with urinary tract infectio n in 43% of cases and/or renal calculi in 78%. Mean calculus diameter was 1 0.2 mm. and mean diverticular diameter was 10.9 mm. An open ended ureteral catheter was placed into the renal pelvis via cystoscopy. Retrograde instil lation of radiopaque contrast medium facilitated the localization of a perc utaneous renal puncture made directly into the caliceal diverticulum. A fle xible tip guide wire was coiled in the diverticulum, and no effort was made to traverse the infundibulum and establish continuity with the remainder o f the collecting system. Tract dilation into the caliceal diverticulum was performed, and percutaneous stone fragmentation and extraction were accompl ished. The lining of the caliceal diverticulum was electrocauterized using a roller ball electrode. A balloon nephrostomy tube consisting of a Foley c atheter with the tip cut off was positioned into the diverticulum. An indwe lling ureteral stent was placed and a Foley catheter provided bladder drain age for 48 hours to maintain a low pressure system. The nephrostomy tube wa s removed after 24 to 48 hours and the ureteral stent was removed after 2 t o 4 weeks. Results: Mean operative time was 162 minutes and mean hospital stay was 2.3 days. Obliteration of the diverticular infundibulum and cavity was documen ted by contrast radiography (excretory urography or retrograde pyelography) , and noncontrast and contrast enhanced computerized tomography, respective ly, in all 14 patients. No patients have had recurrent symptoms, calculi or urinary tract infection at a mean 38-month followup. Conclusions: Percutaneous electrocautery ablation of caliceal diverticula w ithout cannulation or dilation of the diverticular infundibulum represents a safe and effective mode of therapy. Careful patient selection and prepara tion optimize the efficacy of this technique.