Background:
Flexible endoscopic based endoluminal and transgastric surgery for cholecystectomy, appendectomy, gastric reduction for obesity, and antireflux procedures show great promise for less invasive surgery. Current endoscopes and instruments are inadequate to perform complex surgeries. The lack of support for a retroflexed endoscope in the peritoneal cavity makes it hard to reach remote structures and makes the necessary vigorous retraction of tissues and organs such as the liver, stomach, gallbladder or intestines difficult. When flexible instruments are pushed against such structures the unsupported endoscope is pushed away without improving exposure.

Aim:
to develop and test a new articulating flexible endoscopic guide with ShapeLock™ technology (USGI Medical) for subdiaphragmatic and biliary transgastric endosurgery.

Methods, prototype design and testing:
Flexible multilumen guides were constructed using ShapeLock technology and tested during transgastric endosurgical procedures. New design features include multidirectional mid body and/or tip angulation. This device has two 6mm accessory channels as well as a 4mm channel for ultraslim experimental video endoscopes using new CCD chip technology (Pentax 3mm, Olympus 3mm). This allowed the use of new large (5mm) flexible endosurgical instruments. These devices were tested in 45 Kg pigs.

Results:
Cholecystectomy and a variety of transgastic procedures were performed through an anterior gastrotomy created with a needle-knife cautery. The positions of the device, camera and endosurgical instruments, with and without ShapeLock technology, were recorded using videofluroscopy and endoscopy. The endoscope and ShapeLock device were passed through an incision in the wall of the stomach and retroflexed in the upper peritoneal cavity allowing good access to the gall-bladder, upper stomach and right crus. Unlocking the device prevented effective liver retraction, exposure of upper peritoneal structures was lost, and pressure on flexible instruments simply pushed the endoscope and conduit away from the target organ.

Conclusion:
A new endosurgical multilumen device incorporating midbody retroflexion and ShapeLock technology allowed effective retraction of the liver and stomach to allow exposure of the diaphragm. This technology may serve as the needed platform for transgastric cholecystectomy, gastric reduction, fundoplication, hiatus hernia repair or other advanced endosurgical procedures.