A. Mishra1, N. Bartschat1, D. Thompson1, H. A. Lanewalla3, L. Weaver2, A. Troester2, P. Goffredo2, I. Hassan1 2University Of Minnesota, Department Of General Surgery, Minneapolis, MN, USA 3Aga Khan University Medical College, Karachi, Sindh, Pakistan 1University Of Iowa, Department Of Surgery, Iowa City, IA, USA
Introduction: Abdominoperineal resection (APR) is required in the management of patients with rectal cancers (RC) who cannot undergo sphincter preservation. Laparoscopic (lap) and robotic (rob) APRs have been found to be technically feasible and oncologically adequate. However, APR is a challenging operation and can require conversion to an open approach due to patient and disease factors. There is limited data on factors associated with lap- and rob-conversions and its impact on perioperative outcomes outside of institutional studies and controlled trials.We evaluated patient and disease factors associated with lap- and rob- conversions after APRs and the impact on 30-day perioperative outcomes utilizing the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) targeted proctectomy dataset.
Methods: Using the CPT code 45395, the database was queried for patients undergoing an APR between 2016 and 2020 for cancer. Patients with an approach identified as lap-, rob- and lap- or rob- converted to open were included. Univariate and multivariate, stepwise logistic regression analyses were used.
Results:A cohort of 1,229 lap (mean age 64 years, 60% male, median BMI 27 kg/m2) and 1,088 rob patients (mean age 63 years, 63% male, median BMI 27 kg/m2) was analyzed.The conversion rates were 17% for lap and 5.5% for rob cases.
After adjustments, obesity and advanced pathologic tumor stage were independently associated with increased risk of conversion for lap- and rob- APR but receipt of neoadjuvant therapy was not. (Table)
Lap-conversion had a higher incidence of overall complications (36% vs 20%; p<0.001) but rob-conversion did not (23% vs 30%; p=0.22).
Positive Circumferential margin (CRM) was not different after lap-conversion (13% vs 9% (p= 0.08) but higher after rob-conversion (20% vs. 10% (p= 0.02)
On regression analysis lap-conversion was associated with increased risk of complications (OR 1.7;95% CI 1.1-2.7) along with patients’ functional status and ASA >3 however BMI was not associated with an increased risk of complications. While rob-conversions did not increase the risk of complications, an increased BMI was independently associated with risk of complications (BMI 35-40 (OR: 2.4, 95% CI 1.4-3.9) and > 40 (OR: 2.8, 95% CI 1.5-5.1)
Conclusion:Due to a potential selection bias there may be differences in the incidence and factors associated conversion after lap- and rob- APRs. However regardless of approach, obesity is a significant risk factor for perioperative morbidity. The adverse impact of conversions should be considered in determining the operative approach for patients undergoing proctectomy.
