P22: Adoption of Robotic Adrenalectomy is Associated with a Short Learning Curve and Improved Outcomes

Introduction: Robotic-assisted adrenalectomy is feasible and safe, but concerns over increased operative times (OT) and the learning curve (LC) for proficiency have limited its adoption. This study aimed to assess the LC for robotic adrenalectomy.



Methods: This is a two-institution retrospective review of consecutive unilateral minimally invasive adrenalectomies performed by 4 high-volume adrenal surgeons between 2007-2022. Two surgeons transitioned from laparoscopic to robotic adrenalectomy and 2 surgeons adopted the approach, with proctoring, after completion of fellowship training without robotic experience. OT (skin-to-skin) and complications were analyzed. Multivariable regression was used to identify factors associated with OT. The number of cases required to overcome the LC was determined using the LC-cumulative-sum (LC-CUSUM) analysis. OT was used as a proxy of proficiency, at a threshold of 180 minutes. Adequate or inadequate proficiency was defined as 20% or 35% of cases above this threshold, respectively.


Results: Of 457 adrenalectomies, 182 (40%) were laparoscopic and 275 (60%) robotic. Robotic approach was associated with shorter median OT (106 vs. 119 min; p=0.002), fewer complications (6% vs. 13%;p=0.018), and conversions to open adrenalectomy (1% vs. 4%;p=0.030), with no difference between the experienced or proctored surgeons. Compared to the first 10 cases, there was a mean reduction in OT of 22 min after 10-20 cases, 46 min after 20-30 cases, and 50 min after >30 cases, regardless of surgeon experience. The LC-CUSUM analysis showed proficiency after a range of 8-29 procedures. Factors associated with increased OT were BMI >30 kg/m2 (p < 0.001), cortical hyperplasia (p=0.006) or metastatic cancer (p=0.007) on pathology, and higher gland weight (p < 0.001).


Conclusions: This study identified a LC of < 30 cases for robotic adrenalectomy, irrespective of previous independent experience, and improved patient outcomes with the robotic approach. The current findings suggest that with appropriate teams and proctoring, robotic adrenalectomy can be safely adopted at high-volume centers.