OGBN P08 Novel technique of Zooming Inside Narrow Orifice (ZINO) could reduce the need for subtotal cholecystectomy and enables intraoperative cholangiography
Authors: Gresz Rahel , Kouli Tasnim , Zino Samer 
Published: December 2022

Abstract

Background
The complete removal of a difficult gallbladder has regularly been an encumbrance for the work of surgeons. A common approach to circumvent hazardous dissection and biliary injury has been performing subtotal cholecystectomy (SC). Reduced exposure of trainees to open total cholecystectomy, inflamed, and fibrotic hepatocystic triangle might contribute to the growing tendency to perform subtotal cholecystectomy as a bail out procedure. However, subtotal cholecystectomy has significant post-operative morbidity and leads to a high incidence of recurrent symptoms.
This abstract aims to describe a novel technique – the Zooming Inside Narrow Orifice (ZINO) technique – to dissect a difficult hepatocystic triangle in a safe plane whilst keeping the vital structures protected. This technique reduces the need for the less desirable subtotal cholecystectomy and enables intraoperative cholangiography.

Methods
Data from laparoscopic cholecystectomy performed by a single surgeon between 01/07/2020–25/05/2022 has been prospectively collected and evaluated. The Zooming Inside Narrow Orifice (ZINO) technique starts with a circular marking of the peritoneum 1–3 cm high on Hartmann's pouch. This marking is deepened until reaching the gallbladder mucosa, without penetrating it. Following this, the dissection is carried out in the submucosal plane towards the neck of the gallbladder. As this is carried out, the surgeon may be able to zoom inside the narrow orifice made by the wall of the gallbladder outside of the mucosa. This dissection is mainly performed using blunt and hydro-dissection and progresses until the neck of the gallbladder or the cystic duct is identified. Once the cystic duct is identified, the surgeon may carry out intraoperative cholangiography to visualize the integrity of the biliary duct system and make sure no stones are left behind.

Results
205 laparoscopic cholecystectomies were performed during the study period. The Zooming Inside Narrow Orifice (ZINO) technique was necessary in 9 cases (4.39%). Five patients were males and four were females. Based on the Nassar difficulty grading, eight of these cases were grade IV and one case was a grade III. By using the novel ZINO technique, not only was total cholecystectomy possible in all cases, but also intraoperative cholangiography was completed in 8 out of 9 cases. Cholangiography was abandoned in one case due to a necrotic, fragile cystic duct in patient who has been admitted with acute cholecystitis for 17 days and underwent ERCP to treat the biliary sepsis with a clear duct. No intraoperative or post-operative complications or readmissions have been recorded. Subtotal cholecystectomy was not performed in any of the 205 patients.

Conclusions
Discussion:Dissection in the submucosal plane will prevent damage to important structures as the dissection is carried out within the wall of the gallbladder. Thus, every structure encountered in this plane is expendable by anatomical definition as it should be related to the gallbladder. Adherence to this technique will protect all the important structures as they are on the other side of the wall of this funnel. It is important to note that diathermy should not be used for dissection to avoid collateral thermal damage through the wall of the gallbladder.

Conclusion
The Zooming Inside Narrow Orifice (ZINO) technique is a novel technique that was necessary to avoid subtotal cholecystectomy in 4.39% of cases - a number that is similar to the rate of the of subtotal cholecystectomy in major centres. The ZINO approach also enables intraoperative cholangiography, avoiding the neglect of unidentified stones in the common bile duct. Our data suggests that the ZINO approach might reduce the rate of subtotal cholecystectomy and their subsequent morbidity.