Identifying unrecognized collecting system entry and the integrity of repair during open partial nephrectomy: comparison of two techniques

Purpose To compare retrograde dye injection through an externalized ureteral catheter with direct needle injection of dye into proximal ureter for identification of unrecognized collecting system disruption and integrity of subsequent repair during open partial nephrectomy. Materials and Methods We retrospectively reviewed the records of 259 consecutive patients who underwent open partial nephrectomy. Externalized ureteral catheters were placed preoperatively in 110 patients (Group 1); needle injection of methylene blue directly into proximal ureter was used in 120 patients (Group 2). No assessment of the collecting system was performed in 29 patients (Group 3). We compared intraoperative parameters, tumor characteristics, collecting system entry and incidence of urine leaks among the three groups. Results The mean tumor diameter was 3.1cm in Group 1, 3.6cm in Group 2, and 3.8 cm in Group 3 (p = 0.04); mean EBL 320cc, 351 cc and 376cc (p = 0.5); mean operative time 193.5 minutes, 221 minutes and 290 minutes (p < 0.001). Collecting system entry was recognized in 63%, 76% and 38% of cases in Groups 1, 2 and 3 respectively. (p = 0.07). Postoperative urine leaks requiring some form of management occurred in 11 patients from group 1 and 6 from group 2. (p = 0.2). No patient in Group 3 developed a urinary leak. Conclusions Identification of unrecognized collecting system disruption as well as postoperative urine leak rate in patients undergoing partial nephrectomy were not influenced by the intraoperative technique of identifying unrecognized collecting system entry. Postoperative urine leaks are uncommon despite recognized collecting system disruption in the majority of patients.