Increased Operative Duration in Minimally Invasive Partial Nephrectomy Is Associated with Significantly Increased Risk of 30-Day Morbidity

Introduction: Operative duration (OD) is associated with complications but has been poorly studied in minimally invasive partial nephrectomy (MIPN). We seek to examine the relationship between OD and complications in MIPN. Methods: The American College of Surgeons National Surgical Quality Improvement Program database was queried from 2011 to 2016 by CPT code. Risk factors for complications were determined using univariable and multivariable analysis. Results: In all, 12,018 patients were examined. OD was broken into deciles, ∼1200 patients in each, by minutes, <111, 111 to 131, 132 to 149, 159 to 164, 165 to 180, 181 to 196, 197 to 215, 216 to 238, 239 to 276, >276. Variables significantly associated with OD (values stated are shortest and longest deciles, respectively) include: male 47.8% and 68.2% of patients; body mass index 28.5 and 31.3 kg/m²; diabetes 13.4% and 23.7%; smoking 20.4% and 22.0%; taking medication for hypertension 53.1% and 64.2%. Morbidities significantly associated with OD (shortest and longest deciles reported, respectively) include: complications 4.2% of patients and 14.2%; postoperative transfusion 1.3% and 7.8%; pulmonary embolism (PE)/deep vein thrombosis 0.5% and 1.2%; renal insufficiency 0.3% and 1.7%; cardiac arrest or stroke 0.3% and 1.4%. On multivariable analysis, patients with OD >180 minutes were significantly more likely to have complications odds ratio of 2.0, 2.3, 2.3, 3.2, and 3.7 for deciles 181 to 196, 197 to 215, 216 to 238, 239 to 276, >276, respectively, p < 0.001. Conclusions: Even when adjusting for patient-specific preoperative factors, OD is an independent predictor of significant morbidity. Patients in the longest decile were nearly four times as likely to have complications. Further study is needed to determine reasons for prolonged OD.