Perception versus reality: A case-matched study assessing the intraoperative hemodynamics of minimally invasive retroperitoneal versus transperitoneal approach to pheochromocytomas.

Background: Pheochromocytomas produce excess catecholamines that can result in intraoperative hemodynamic instability. Centers have reported variations in intraoperative hemodynamics with the retroperitoneoscopic versus the laparoscopic transperitoneal approach to adrenalectomies. When the retroperitoneoscopic approach was initiated for pheochromocytomas at our institution, the perception was of improved intraoperative hemodynamics, hypothesizing that increased retroperitoneoscopic insufflation pressures caused decreased venous return and less fluctuation in circulating catecholamines. The purpose of this study was to examine if a difference in intraoperative hemodynamics exists between a size-matched cohort of laparoscopic transperitoneal and retroperitoneoscopic pheochromocytoma patients.

Methods: Unilateral adrenalectomies for pheochromocytoma performed via laparoscopic transperitoneal or retroperitoneoscopic approaches from 2015 to 2021 were identified from a surgical database. As larger tumors often underwent a laparoscopic transperitoneal approach, cases were matched 1:1 by tumor size. All patients received phenoxybenzamine. Groups were compared by patient characteristics, preoperative blockade, intraoperative hemodynamics and management, and early postoperative outcomes.

Results: There were 13 laparoscopic transperitoneal adrenalectomy cases matched to 13 retroperitoneoscopic cases according to tumor size. Both groups (laparoscopic transperitoneal and retroperitoneoscopic) were similar for age (53 years), body mass index (28.5 vs 29.7), sex (69% female), and side (8 vs 7 right). There was no difference in preoperative 24-hour urine metanephrines/normetanephrines (9.9/8.0 vs 2.4/5.7 μmol/day). The phenoxybenzamine dose was similar in both groups (112 vs 114 mg/24 hours), as were baseline heart rate, blood pressure, and mean arterial pressure. There was no difference in any intraoperative hemodynamic parameters or vasoactive interventions. Operative time, length of stay, and 30-day emergency visits were similar between groups.

Conclusion: This matched cohort study did not find a difference in intraoperative hemodynamics between laparoscopic transperitoneal and retroperitoneoscopic adrenalectomy approaches for pheochromocytoma in appropriately selected and blocked patients.