Laparoscopic cholecystectomy (LC) is “gold standard” surgical management of symptomatic gallstones. However, the incidence of bile duct injury in LC is still double greater compared to classic open surgery. The most blamed causative factor is the misidentification of the anatomy, especially by a surgeon who is at the beginning of his learning curve [1],[2],[3]. The routine use of Intraoperative cholangiography (IOC) to delineate the extrahepatic biliary anatomy in LC remains controversial and selective use of IOC has been recommended [4],[5]. Biliary tree injuries may be decreased by direct coloration of the cystic duct by a technique in which the methylene blue (MB) is injected into the lumen of gall bladder to delineate the cystic duct and common bile duct. This technique seems easier to perform, without any radiation exposure and less time consuming than conventional IOC [6].

The aim of this work was to assess safety, effectiveness and feasibility of trans- cholecystic methylene blue injection for better delineation of extra hepatic biliary ducts and proper assessment of biliary anatomy for prevention of bile ducts injury during laparoscopic cholecystectomy.

This study was done during the period from August 2017 to March 2018 and included 50 consecutive patients with chronic calcular cholecystitis who are candidates for laparoscopic cholecystectomy. None of the patients reported history of jaundice within the last year and had pulmonary or cardiac disease.

All patients had been consented to a laparoscopic cholecystectomy with need for methylene blue injection for better delineation of biliary anatomy for prevention of bile ducts injury during laparoscopic cholecystectomy. All patients were informed that they might pass blue urine in the early post-operative period. The Ethics Committee of Theodor Bilharz Research Institute (TBRI) approved this study.

Surgical procedure

During laparoscopic cholecystectomy, once the gall bladder fundus freed from adhesions, it was grasped and held tight towards the anterior abdominal wall with the help of two atraumatic graspers introduced via right anterior axillary and subxyphoid trocars. The gall bladder fundus was punctured by a Veress needle which was introduced via the abdominal wall in projection to this area. All the bile in the gall bladder was aspirated (Figure 1 A & B) and 50 percent diluted MB equal to the amount of aspirated bile was injected slowly into the gall bladder (Since the usual capacity of the gallbladder is only about 30–60 ml, so the maximum amount of diluted MB could be injected is about 15–30 mg) (Figure 1C). In order to prevent MB leakage, the gall bladder fundus was held tight interiorly during the withdrawal of the Veress needle and a grasper introduced via the right axillary trocar was applied immediately to the puncture site and was held so throughout the operation or the puncture site was clipped with a clip (Figure 2). The region was irrigated with saline solution. During cholecystectomy, the gall bladder, cystic duct and common bile duct were visible and delineated with MB dye and the dissection was performed more safely (Figure 3). In order to prevent MB leakage, an endobag was used to extract gall bladder (Figure 4). A closed suction drain was left in the right sub hepatic space and exteriorized through the right lateral trocar site.

Evaluation

The evaluation based mainly on the clear anatomical delineation of the gall bladder, cystic duct, hepatic ducts and common bile duct. In addition, intra-peritoneal spillage of MB, surgical time, post-operative complications, biliary injury and postoperative hospital stay were documented.

The study included fifty cases with chronic calcular cholecystitis underwent elective laparoscopic cholecystectomy with trans-cholecystic injection of MB. They ranged in age from 20 to 67 years (mean = 34.6±13.74 years). A 45 patients (90%) were females, while five patients (10%) of them were males. By using this technique all gall bladders, 48 (96%) cystic ducts, while 42 (84%) common bile ducts were painted (Table 1). In nine cases (18%), methylene blue leakage from the gall bladder into the abdominal cavity was observed (Figure 5). The region was irrigated with saline solution. None of the patients developed any complication related to the technique except one patient who developed immediate bluish discoloration of skin and mucous membrane (lips, finger tips) for 15 sec due to inadvertent injection of MB in a vessel in the gall bladder wall during MB injection into GB. The operative time ranged from 60-105 minutes with mean 78.63±12.37 minutes. It was observed that the mean operative time is slightly but insignificantly prolonged in patients which we failed to visualize the cystic duct by MB dye (mean operative time 83.3±10.2 versus 77.2±12.8 minutes, p value = 0.24). The hospital stay postoperatively ranged from 1 to 3 days (mean 1.13±0.43 days).

Although the usefulness of IOC to prevent bile duct injury is emphasized by a many authors, its importance still remains debatable and its routine application does not have a critical proficient benefit. Disadvantages of IOC are prolongation of the operative time, radiation exposure, increased cost and false positive results, leading to avoidable CBD exploration and the necessity of perception by a qualified radiologist [7],[8],[9].

Therefore, a technique by which MB is injected into the lumen of gall bladder to delineate the cystic duct and common bile duct seems cheap, easier to perform, without any radiation exposure and less time consuming than conventional IOC [6]. In the same time , the usual capacity of the gallbladder is only about 30–60 ml, So the maximum amount of (50 % diluted methylene blue equal to the amount of aspirated bile) could be injected is about 15–30 mg which is very safe (toxic dose is > 5 mg/kg) [6].

By using this technique in our study all gall bladders, 96% of cystic ducts and 84% common bile ducts were painted, which is significantly important. MB leakage from the gall bladder into the abdominal cavity during injection of dye with the need of irrigation with saline, does not affect the procedure and increases the mean operative time but not statistically significant (100.2±3.56 versus 74.32±8.16 minutes & p value = 0.241). Although the biliary tree could be visualized in most cases, the high rate of MB spillage of the present study which could be avoided by clipping gall bladder fundus with clip or tight holding it using non traumatic grasper. Because MB is excreted by the kidneys, the patients should be informed of the likelihood of blue urine in the early post-operative period, which already occurred in three cases only (6%). It was observed that the mean operative time is slightly prolonged in patients which we failed to visualize the cystic duct by MB dye (mean operative time 83.3±10.2 versus 77.2±12.8 minutes, p value = 0.24). With mean operative time 74.31±12.22 minutes (p value = 0.26). The dissection was performed much more safely, since the boundaries of the gall bladder and bile ducts were significantly defined and painted with MB. In cases with no free passages of the dye to the CBD , it might be due to gall bladders being loaded with stones, impacted by a large stone at Hartman‘s pouch, or had very thick wall. In our study, MB can outline the bile ducts but without any impact in distinguishing bile duct stones. No biliary injuries were confronted in our cases. The primary cause of biliary injury during laparoscopic cholecystectomy in 97% of cases was a visual intuitive misconception. Faults in technical skill were present in only 3% of injuries [10]. So, our study is concerned to decrease the main cause of biliary injury.

The intraoperative injection of methylene blue into the gall bladder fundus during laparoscopic cholecystectomy for direct visualization of the gall bladder, cystic duct and common bile duct is a feasible, cheap and easy maneuver without any radiation exposure or special equipment. This technique is proposed as an optional method in case of dissection difficulty of Calot’s triangle during laparoscopic cholecystectomy to decrease the main cause of biliary injury.