Simon Erridge1, Christopher Payne2, Mikael Sodergren1. 1Department of Surgery and Cancer, Imperial College London, UK, 2John A. Paulson School of Engineering and Applied Sciences, Harvard University
Objective: Ligation clips are used ubiquitously throughout minimally invasive surgery for apposition of tissues. However, their size limits their application beyond ligation of small tubular structures. Traditional clip applicators only provide rotation through the axis of the shaft; therefore tissue approximation may fail when the tissue cannot be positioned perpendicularly to the clip applicator. Our team at Imperial College London has developed a novel clip and applicator that allows for broad-area clamping and clip rotation. The potential applications of this are widespread but include staple line reinforcement in bariatric surgery, enterotomy closure and peptic ulcer perforation management.
Technology: The clip design consists of two ‘clamping bars’ with a brace to which it is loaded onto a clip applicator. Our prototype clip measures 10mm x 2.5mm x 15mm (length x depth x width). Using a batch making process the clip size can also be adapted to a variable range of widths (8-24mm). Complementary to this, the clip is designed to help provide rotation to improve tissue approximation. To achieve this the clip has a ‘dimple feature’. This forms a pivot point about which the clip can be rotated in the jaws of the applicator but also serves to generate the torque required to rotate the clip. The clip applicator has been developed in parallel with the clip. Whilst traditional designs allow 360o of rotation of the shaft, our design has the added capability of 0-110o of rotation of the clip around a pivot. This is carried out using a tendon-based system that is controlled using a lever located at the back of the handle for ease of use. The clip is held on spring-loaded jaws to enable precision firing on holding down the trigger.
Preliminary Results: A comparative study evaluating the maximum load (N) held across two opposed tissues by a) our novel broad-area clip and b) a conventional commercial clip was performed. Two sections of porcine bowel were clamped together and the maximum load (N) was measured using a tensile strength material testing machine. The mechanical clip properties were compared using a t-test. Statistical significance was determined by P<0.05. Twenty-four samples (intervention = 15; control = 9) of porcine bowel annealed by surgical clips were tested. The mean maximum force withheld by the bowel and staples was greater for our novel clip design (2.043 N ± 0.831) than the control clip (1.080 N ± 0.466, p=0.004).
Conclusions: These preliminary results suggest that our novel clip is able to withstand higher tensile force across tissues compared to a leading commercial clip. Whilst further iteration of product design and clinical testing is required, this product may occupy an important clinical niche through staple line reinforcement, enterotomy closure and other applications.
Presented at the SAGES 2017 Annual Meeting in Houston, TX.
Abstract ID: 98693
Program Number: ETP714
Presentation Session: Emerging Technology Poster Session (Non CME)
Presentation Type: Poster