Robotic minimally invasive esophagectomy provides superior surgical resection

Abstract

Introduction: Robotic minimally invasive esophagectomy (RMIE) and "traditional" minimally invasive esophagectomy techniques (tMIE) have reported superior outcomes relative to open techniques. Differences in the outcomes of these two approaches have not been examined. We hypothesized that short-term outcomes of RMIE would be superior to tMIE.

Methods and procedures: The National Cancer Database was used to analyze outcomes of patients undergoing RMIE and tMIE from 2010 to 2016. Patients with clinical metastatic disease were excluded. Trends in the number of procedures performed with each approach were described using linear regression testing. Primary outcome of interest was 90-day mortality rate. Secondary outcomes of interest were positive surgical margin rate, number of lymph nodes (LN) removed, adequate lymphadenectomy (> 15 LNs), length of hospitalization (LOS), readmission rate, and conversion to open rate. Outcomes of RMIE and tMIE were compared using Wilcoxon rank sum test and chi square test as appropriate. Multivariable regression was also performed to reduce the impact of differences in the cohorts of patients receiving RMIE and tMIE.

Results: 6661 minimally invasive esophagectomies were performed from 2010 to 2016 (1543/6661 (23.2%) RMIE and 5118/6661 (76.8%) tMIE). Over the study period, the proportion of RMIE increased from 10.4% (64/618) in 2010 to 27.2% (331/1216) in 2016 (p < 0.001) (Fig. 1). The primary outcome of 90-day mortality was similar between RMIE and tMIE (92/1170 (7.4%) vs 305/4148 (7.9%), p = 0.558) (Table 2). RMIE and tMIE also had similar readmission rate (6.3 vs 7%, p = 0.380). There was no difference between the cohorts based on sex, age, race, insurance, and tumor size. The cohorts of patients receiving RMIE and tMIE differed in that RMIE patients had lower rates of elevated Charlson scores, were more likely to be treated at an academic institution, had a higher rate of advanced clinical T-stage and clinical nodal involvement, and had received neoadjuvant therapy. In a univariate analysis, RMIE had a lower rate of positive margin (3.9 vs 6.1%, p = 0.001), more mean lymph nodes evaluated (16.6 ± 9.74 vs 16.1 ± 10.08 p = 0.018), lower conversion to open rate (5.4 vs 11.4%, p < 0.001), and a shorter mean length of stay (12.1 ± 10.39 vs 12.8 ± 11.18 days, p < 0.001). In multivariable analysis, RMIE was associated with lower risk of conversion to open (OR 0.51, 95% CI: 0.37-0.70, p < 0.001) and lower rate of positive margin (OR 0.62, 95% CI: 0.41-0.93, p = 0.021).). Additionally, in a multivariable logistic regression, RMIE demonstrated superior adequate lymphadenectomy (> 15 LNs) (OR 1.18, 95% CI 1.02-1.37, p < 0.032).

Conclusion: In the National Cancer Database, robotic esophagectomy is associated with superior rate of conversion to open and positive surgical margin status. We speculate enhanced dexterity and visualization of RMIE facilitates intraoperative performance leading to improvement in these outcomes.

Keywords: Esophageal cancer; Esophagectomy; Minimally- invasive surgery; Robotic surgery; Thoracic surgery.