Mehraneh D Jafari, MD, Joseph C Carmichael, MD, Alessio Pigazzi, MD, PhD. University of California, Irvine, School of Medicine
Background/Objective:
Transanal endoscopic approaches to resect rectal lesions have been well characterized. However, current techniques have significant challenges and a steep learning curve due to the rigid nature of the instruments and limited visualization.
The Flex® Robotic System is an operator-controlled computer assisted flexible endoscope that enables the physician to easily access and visualize structures within the oropharynx and laryngopharynx down to and including the vocal cords. Like other endoscopes, visualization is provided by a HD digital camera incorporated in the distal end of the scope. The Flex® Robotic System endoscope also provides 2 accessory channels for compatible flexible instruments which are easily viewed when extended from the distal end of the scope.
The objective of our study was to modify the Flex® Robotic System to ensure a stable pneumorectum and assess the safety and effectiveness of the system to perform resections in the rectum and distal colon in a cadaveric and porcine model.
Study Design/Material and Methods:
The cadaveric study evaluated the modified Flex Robotic System’s ability to facilitate access for and visualization of surgical resection and closure in the human rectum. Two surgeons performed transanal surgery in three cadavers each (a total of six) using the modified Flex® Robotic System and Flex Instruments in locations ranging from the anal verge to the rectosigmoid junction. Each surgery consisted of surgically resecting a portion of the rectal wall and closing the resultant surgical defect. In addition to the planned surgeries, to ensure all quadrants of the rectum were evaluated equally, each surgeon visualized and touched one pre-specified area of the anatomy prior to surgery in one cadaver.
The porcine study evaluated the modified Flex Robotic System’s ability to facilitate visualization and access for transanal surgery in a live tissue model compared to a control, the Storz TEO Instrument System. A total of eight swine (two control animals and six test animals) underwent surgical resection in the rectum and suture closure of the resected area. The surgical area was evaluated visually upon completion of the study and again at 7-8 days post-procedure.
Results
Cadaveric Study:
Resections were successfully completed 93% of the time with success defined as the resected tissue size being between one quarter and one third of the rectal circumference. Closure was successful in 92% of the surgeries with success defined as full approximation of the edges of the wound without gaps. In both visualization and touching procedures, the surgeon was able to visualize and touch the specified area of the rectum 100% of the time.
Porcine Study:
Results showed acceptable tissue response at day 0 and day 7 or 8. Tissue scores were also consistent between the control and test groups. In addition, the animals appeared to tolerate the test and control surgical procedures without any in-life or gross abnormalities at necropsy attributable to the test or control devices.
Conclusion:
These studies demonstrate the feasibility of the modified Flex® Robotic System to perform transanal resections in the rectum and distal colon.
Presented at the SAGES 2017 Annual Meeting in Houston, TX.
Abstract ID: 84457
Program Number: ETP755
Presentation Session: Emerging Technology Poster
Presentation Type: Poster
