An integrated method for contained laparoscopic specimen removal

Abstract

Efforts at minimizing pain following minimally invasive (MIS) hysterectomy were hampered by the absence of simple, reliable methods to extract specimens following the 2014 FDA safety warning discouraging power morcellation. To address this gap, an integrated method intended to provide reliable specimen containment with a multi-layer bag, segmentation using bipolar energy, and tissue extraction during laparoscopic gynecological surgical procedures was developed. This report details the pre-clinical studies demonstrating specimen containment integrity, and thermal and electrical safety of the Eximis™ CS (Contained Segmentation) Procedure. All experiments were performed in pigs and approved by the research facility's institutional animal care committee and met USDA and AAALAC guidelines. The study design was composed of three experimental groups; Bovine tongue muscle to simulate normal uterine tissue, bovine tendon draped in a “sausage casing” to simulate hard-thick myoma tissues, and a polymer block wrapped with bacon strips to simulate a severely calcified fibroid. Additionally, there were two control groups: one negative and one positive (heat gun). Each experimental group was tested in four Eximis Capture Bags (8 cuts each) for a total of 24 electromechanical cuts. Thermal evaluation of the small bowel adjacent to the capture bag during device activation was performed with a Micronor FOTEMP4-PLUS-P0-V-B fiberoptic thermometry system. Specimens were then harvested for histology and graded by a blinded pathologist using the Histopathology Scoring Criteria (edema/necrosis/inflammation); 0-4; none to marked. Electrical testing evaluated high frequency electrical leakage current by an independent laboratory with the electrosurgical generator set to 200 W output power, the maximum output setting allowable. Finally, Eximis Capture Bags were tested after segmentation using a proprietary leak test that can detect leaks < a 1 μm hole size. The test group simulating normal uterine tissue (bovine tongue) had small bowel histopathology not different from the negative control group. The calcified fibroid and myoma test groups demonstrated statistically more mucosal edema than the negative control group, but differences were not observed in the submucosa or muscularis layers that were closer to the containment bag. The Eximis Capture Bag measured leakage current directly through the bag of 1.01 mA well below the maximum allowable standard of 150 mA. No evidence of leaks was detected. These studies demonstrate that the Eximis CS is thermally and electrically safe to surrounding tissues and that tissue segmentation and extraction do not impact Eximis Capture Bag’s integrity. Clinical evaluation during human and robotic gynecologic procedures for benign disease is warranted. Additionally, these results suggest the system may be beneficial in other MIS procedures where large specimens are removed.View Large Image Figure ViewerDownload Hi-res image Download (PPT)