S. Hernandez1, M. E. Schwab1, H. Chern1, M. Varma1, A. Sarin1 1University Of California – San Francisco, Department Of Surgery, San Francisco, CA, USA
Introduction: Robotic transanal minimally invasive surgery (R-TAMIS) is an increasingly appealing alternative to transanal minimally invasive surgery (TAMIS) and transanal endoscopic microsurgery (TEM) for benign and early malignant rectal lesions that are not amenable to traditional open transanal excision technique. However, there is a lack of data comparing the three different techniques. This study sought to compare operative, perioperative, and pathological outcomes of the three approaches at a single tertiary academic institute.
Methods: Patients who underwent transanal excision of a rectal lesion using one of the three techniques at a single academic center were collected from a database of consecutive patients undergoing colorectal surgery (2016-2020). Patient’s electronic medical records were retrospectively reviewed for demographics and clinical diagnosis; intra-operative details such as operative time, lesion location and size; pathological diagnosis, intactness of specimen, and margins; and post-operative complications and outcomes. The three groups were compared using chi-square test for categorical variables and Kruskall-Wallis test for continuous data.
Results: Twenty-nine patients were analyzed: 13 TEM, 6 TAMIS, 10 R-TAMIS. There were sixteen women with a median cohort age of 57 (IQR:28-81). Twenty-two (76%) patients identified as White. Patients who underwent R-TAMIS, 24.7 (23.8-28.7), had a lower BMI compared to those that underwent TEM, 29.3 (19.9-30.2), and TAMIS, 30.4 (26.6-32.9). A higher proportion of patients who underwent TAMIS (80%) and R-TAMIS (66.7%) had high grade dysplasia/invasive cancer compared to those who had TEM (41.7%). However, there was no statistically significant difference in tumor type or distance from the anal verge among the three procedures (Table 1). There were no patients who underwent R-TAMIS who had a positive margin and their procedure was performed faster than TAMIS and TEM (Table 1). There was no statistically significant difference between length of stay (p=0.6) and 30-day readmission rates (p=0.513) between the techniques. R-TAMIS (80.0%) had a larger proportion of patients who did not require any further follow up or surgery after their procedure compared to TAMIS (16.7%) and TEM (53.9%) (p=0.09).
Conclusion: Robotic TAMIS may have several advantages over conventional endoscopic and laparoscopic excision of transanal lesions. There was a trend towards R-TAMIS being faster and resulting in negative surgical margins, compared to the two other techniques. Larger studies are needed to confirm these findings and identify the role of robotic TAMIS in the care of patients with rectal lesions.
