Here I will be writing about bile duct injury and will focus on the human factors that have been shown to be the non-technical root causes. I will then list and explain the strategies to minimise the risk.
Bile duct injury still remains common compared to the era of open cholecystectomy. The overall rate of bile duct injury of all types in most large population based studies of laparoscopic cholecystectomy has been found to be around 0.4%. One in three surgeons will cause the injury during their working life time. Bile duct injury has a major detrimental effect on the patient’s physical and psychological wellbeing affecting their quality of life considerably and remains a common reason for medico-legal claims.
It is worth remembering that the majority of injuries are discovered postoperatively in cases described by the surgeon as otherwise straightforward. Even experienced surgeons are not immune from causing the injury. The injuries fall into a number of set patterns implying common underlying reasons. Injury to the bile duct is typically caused either due to poor technique or due to wrong identification of the anatomy. Poor technique includes causing bleeding intra-operatively, misuse of clips and electrocautery, and traction injuries. Poor technique tendS to manifest more in the presence of certain conditions such as acute cholecystitis, and obesity. However, the majority of severe injuries are due to non-technical causes.
In many of the severe bile duct injuries the root causes appear to be spatial disorientation and confirmation bias.
In the classic spatial disorientation, the surgeon mistakenly sees the bile duct as the cystic duct. This occurs when the Hartmann’s pouch is retracted towards the liver and not laterally as it should be, and as a result the cystic duct and the bile duct become aligned. Once the bile duct is mistaken as the cystic duct, the surgeon will subconsciously look for evidence to confirm rather than refute that his findings are correct. This is known as the conformation bias. The optical illusion thus created makes the bile duct appear as the cystic duct; and the bile duct is clipped and transected. The surgeon then continues the dissection up towards the liver for completing gallbladder dissection, only to come across a second structure, the common hepatic duct which is in turn transected.
So what are the surgical rules to follow to avoiding bile duct injuries caused by misidentification:
Rule number one during surgery is to bear in mind that you may be wrong in your assumptions about the anatomy. The easier the gallbladder appears to you, the more worried you should be that you may be looking at an optical illusion. Remember many major injuries are detected postoperatively in apparently easy gallbladders. The surgeon should not assume anything and should be consciously looking for evidence that refutes what he or she believes in. In other words you look for reasons why the cystic duct that you are dissecting could be the bile duct. This is not easy and goes against the natural tendency of looking for evidence that confirms that the cystic duct is indeed the cystic duct.
Rule number two is to have regular time outs to look out for key anatomical landmarks to re-orientate yourself. This is achieved by focusing the laparoscope out and to look for the liver sulcus, duodenum, porta hepatis, falciform ligament and liver. The timeouts need to be regular and frequent. Again this is important even if the gallbladder anatomy looks straightforward since you may be misreading the anatomy.
Rule number 3 is to achieve the critical view of safety. For this, the aim is to dissect the hepato-cystic triangle so that you have only two structures going into the gallbladder. The dissection needs to be extended for at least a third up the posterior gallbladder wall attachment to the liver to ensure no structures go back into the liver.
Rule number 4 “safety first, total cholecystectomy second”. in other words if you cannot confidently achieve the critical view of safety, then a bailout strategy is the correct action which means performing either a subtotal cholecystectomy or a cholecystostomy. In subtotal cholecystectomy, the anterior wall of the gallbladder is resected, stones removed and the gallbladder bed is drained. Some surgeons attempt to suture-close the cystic duct from inside once the anterior wall of the gallbladder is removed. It is essential that you place drains into the gallbladder area even in the absence of any visible bile leak, since once the inflammation subsides the cystic duct could open up and start leaking bile postoperatively. Often a number of drains are placed, including one to the gallbladder bed, one to the foramen of Winslow posterior to port hepatis and the other placed under the live laterally.
Most low volume bile leaks following subtotal cholecystectomy subside spontaneously but if there is large volume or prolonged period of bile leak, you may consider an ERCP and stenting. This usually results in a rapid resolution of the leak.
So what should you do if you find yourself in the unfortunate situation of having caused a bile duct injury during surgery.
2 things are required:
First, you should not attempt to do any further dissection as this will either extend the injury or devascularise the bile duct. Conversion to open surgery is not indicated either. Instead you should communicate your concerns with the theatre team clearly, and have a time-out or de-scrub.
Second, you should discuss the problem with an experienced HPB surgeon. The evidence suggests that the best surgical outcomes come from repairs done at the time of the index operation by an experienced HPB surgeon. The HPB surgeon is very likely to perform an intra-operative cholangiogram before deciding on the type of repair. In most cases the choice of repair is a hepatico-jejunostomy. However, You may have to transfer the patient to a tertiary centre if no expertises exists locally. The abdomen needs to be adequately drained prior to the transfer and clear operation notes detailing all the operative events should be recorded in the patient’s medical files before the transfer.