Is Routine Transposition of Anterior Crossing Vessels During Laparoscopic Dismembered Pyeloplasty Necessary?

Purpose: To assess the need for routine transposition of an anterior crossing vessel during dismembered laparoscopic pyeloplasty. Patients and Methods: We reviewed data from 70 patients who were undergoing laparoscopic pyeloplasty at our institution from March 2000 to December 2004 for ureteropelvic junction (UPJ) obstruction. An anterior crossing vessel was identified intraoperatively in 31 (44%) patients. The decision to transpose was made by the surgeon's intraoperative perception of the obstructive nature of the mobilized vessel after UPJ dismemberment. Outcomes between the groups who were undergoing transposition of the vessel (n = 8) were retrospectively compared with the group not undergoing transposition (n = 23). Success was defined by symptom resolution and evidence of improved drainage on diuretic renographic or urographic imaging. Results: All 31 patients had resolution of obstruction. Both groups were similar as regards preoperative and postoperative differential function and t(1/2) on diuretic renography. The laparoscopic approach, however, was significantly different between the two groups. The majority of patients (87.5%) in whom the vessel was transposed underwent transperitoneal laparoscopic pyeloplasty. In contrast, the majority of patients (74%) in whom the vessel was not transposed underwent retroperitoneoscopic pyeloplasty (P = 0.004). As such, only 1 of 18 (6%) patients who were treated retroperitoneally received a vessel transposition compared with 7 of 13 (54%) of patients in whom the surgery was transperitoneally. Conclusions: During laparoscopic pyeloplasty, routine transposition of an anterior crossing vessel may be unnecessary. The decision to transpose appears to be governed by the surgeon's subjective intraoperative assessment and the choice of laparoscopic approach to facilitate technical ease of reconstruction.