The rate of BDI during LC has reached the level of 0.08–0.2% and is comparable with the open cholecystectomy era what may be associated with better surgical skills, improved instrumentation and the number of LCs performed over "learning curve" [10–12]. The Research Institute Against Cancer of the Digestive System (IRCAD) defines three major causes of BDI: (1) technique associated with the surgeon’s experience and performance, (2) pathology related to the extent of inflammation and (3) presence of anatomical variations whereas the most common reason of BDI is the misidentification of the common hepatic/bile duct instead of the cystic duct [10, 13, 14]. The safest way to complete cholecystectomy is to obtain CVS but the problems may arise in the case of inflammation in the region of Calot’s triangle [10, 13, 14]. CVS is not a dissection technique, but rather a technique of identification similar to the safety measures during hunting or flying [13, 15]. There is no need to expose the common bile or hepatic duct while obtaining CVS . CVS usually protects against incorrect identification but not against BDI and VBI during dissection when the local conditions are changed . The possible bail-out techniques when CVS can not be reached include FF LC, subtotal LC, tube cholecystostomy or conversion [2, 16].
FF LC is an alternative technique when there is a severe inflammation or fibrosis in the triangle of Calot . During FF LC the gallbladder is dissected off the liver bed beginning with the fundus towards the infundibulum until it is hanging on the cystic duct and the cystic artery or it may be combined with the subtotal cholecystectomy . The preferred dissection technique should be between the subserosal outer and inner layer of the gallbladder wall but in case of inflammation it may be very difficult . The complications may involve haemorrhage from the liver bed or the gallbladder wall, migration of stones into the common bile duct or BDI/VBI associated with improper plane of dissection and higher rate of perforation of the gallbladder wall thus a step-by-step preparation and proper hemostasis are advised [2, 3, 5]. During standard technique the grasper on the fundus of the gallbladder is used to apply traction to expose the triangle of Calot . When there are problems with the traction during FF the liver may be kept elevated by retractor . LUS defines very precisely the border between the gallbladder neck and common bile/hepatic duct enabling safe dissection plane. LUS is non-invasive, there is no need to cannulate the cystic duct and use the contrast dye. It is safe for both the patient and operating team and may be repeated as many times as it is needed . IOC in case of advanced inflammatory changes usually fails [4, 5].
FF technique leads to the reduction of conversion rate. The reported conversion rate for elective LC is 4–6% and for acute LC is 5–10% but recently the reported conversion rate was also very low at 0.04% [2, 17]. Mangieri et al. had an incidence of BDI in converted cases at the level of 15% what makes the conversion with the current era of surgeons not experienced with the open approach a doubtful safe bail-out option because the worst VBI often occur after conversion [8, 17, 18]. According to our study FF technique with LUS enables safe performance of LC with significantly lower conversion rate associated with improved postoperative recovery.
Another bail-out option is subtotal cholecystectomy which may be performed in two ways. The first option entails removal of peritonealised part of the gallbladder leaving the remnant of the wall in liver bed and closure of the cystic duct orifice from the inside with a purse string suture. The gallbladder remnant is either left open in fenestrating variant or oversewn in the second reconstituting variant . The latter may expose the patient to the recurrence of gallstone disease due to the closed remnant of the gallbladder (with the rate of 2.2%) but the open variant is associated with higher bile leaks (10.6%) [10, 13, 14, 19].The key to successful subtotal cholecystectomy is to remove as much as possible gallbladder wall but the surgeon is sometimes not sure where to stop and at which level close the remnant of the gallbladder. The same as with the FF technique LUS defines very precisely the safe plane of dissection without the risk of BDI and VBI. It enables to close the remnant of the gallbladder as close as possible to the bile duct without the risk of the bile leak as in fenestrating variant without a functional gallbladder remnant as in reconstituting variant.
Handzel et al. proposed a semi-top-down technique of LC where dissection starts well above the infundibulum and is directed laterally with the fundus of the gallbladder staying in place for traction. In this method it is important to identify anatomic landmarks before dissection starts-Rouviere’s sulcus, the common bile duct and the gallbladder infundibulum . As we mentioned before these are visual landmarks which in case of inflammation may be difficult to attain making this method in such situation unreliable. Another authors stated that FF LC should be taught to surgical residents when faced with the difficult LC and the FF technique should be in the armamentarium of the laparoscopic surgeon [4, 20].
The limitation of our research was a relatively small number of FF LCs and a single- center type of the study, thus further studies including larger groups of participants in more than one surgical center are needed in order to strengthen our findings and confirm the usefulness of LUS during FF LC, especially in protection against BDI and VBI.