Robotic Pyeloplasty in Patients with Equivocal Diuretic Renogram

Previous studies examining patients with equivocal renal scans performed before robotic assisted pyeloplasty for ureteropelvic junction obstruction have shown conflicting results regarding outcomes. To address these conflicting reports we compared rates of symptom resolution and improvement in postoperative radiographic scans between patients at our institution presenting with equivocal vs obstructed preoperative diuretic renograms.

We conducted a retrospective review of 143 patients who underwent robotic assisted pyeloplasty by a single surgeon at our institution from 2001 to 2017. Patients with preoperative and postoperative diuretic renograms available were included in study. Patients were analyzed in equivocal preoperative imaging or obstructed preoperative imaging groups.

A total of 102 patients were included in this study, 16 with equivocal diuretic renograms and 86 with obstructed diuretic renograms. Mean preoperative differential function was 34.9% in the obstructed group and 43.2% in the equivocal group (p=0.07). Postoperative symptom resolution was equivalent between equivocal and obstructed groups (87.5% vs 89.4%, p=0.69). However, improvement in diuretic renogram obstruction was significantly greater in obstructed compared with equivocal cases (84.7% vs 56.3%, p=0.01).

Surgical management of patients with equivocal obstruction can be challenging. Patients with preoperative equivocal diuretic renograms are less likely to have radiographic improvement after robotic assisted pyeloplasty but do experience equivalent symptom resolution compared to patients with obstructed preoperative diuretic renograms. Symptom improvement rather than improvement in radiographic obstruction should be the primary focus when offering robotic assisted pyeloplasty to patients presenting with equivocal diuretic renograms.