Biliary disease is one of the most common and well described conditions affecting human health, with laparoscopic cholecystectomies being some of the most performed surgeries around the World.
This procedure is not without harm, with modern series of population studies suggesting that about 1.5% of cholecystectomies are complicated by a biliary injury.
There are a number of risk factors that may contribute to biliary injury which may be patient-related, disease-related or extrinsic.
Patient-related factors include male sex, advanced age and obesity, which are non-modifiable.
Disease-related factors are also very important, non-modifiable, and usually discovered only in the intraoperative setting.
Extrinsic factors are related to the surgeon, operative team and operating room.
History of Biliary Surgery
Biliary surgery has experienced a major advance since its first surgical procedure.
In the beginning, surgical treatment targeted complications, like cholecystitis, and it evolved from the removal of gallstones to cholecystectomy in about a century. At the end of the 19th century, surgical intervention was used not only for the complications but also for the prevention of future episodes of biliary colic.
With cholecystectomy came iatrogenic injuries and the need to solve them, and in the mid- 20th century, the techniques used in major procedures, like the Roux-en-Y hepaticojejunostomy, were used to solve some of those injuries.
Anatomy of Gallbladder and Biliary Tree
When performing a cholecystectomy, open or laparoscopic, the surgeon expects to find the typical anatomy of gallbladder, biliary tree and biliary junction: a right biliary duct joins a left biliary duct, forming a common hepatic duct, that joins a cystic duct to form the common biliary duct, that opens in the duodenum in the Vater ampulla. But this only happens in about 57% of people.
In the remaining 43% there are variations, some more common than others, that can be detected in the preoperative setting by means of advanced imaging systems or intraoperatively.
These anatomic variations may predispose to injury, specially in the setting of severe inflammation.
Diagnosis of Biliary Injury
Biliary injury can manifest as leak or obstruction.
The diagnosis of a leak can occur in one of 2 settings: intraoperative or postoperative. Intraoperative diagnosis may be through direct vision or cholangiography. Postoperative diagnosis is based in clinical aspects, laboratory changes and/or imagiological findings.
Obstruction usually manifests later, weeks to months after the surgery, and can result from thermal or vascular injuries, or from iatrogenic stricture of the common biliary duct.
When a biliary injury is suspected, the first step is to confirm it. Radiographic imaging techniques will help identify abnormal fluid collections. Cholangiography, either invasive or noninvasive, will be essential in characterising the injury and planning the treatment, or treating small injuries.
Classification of Biliary Injuries
Since 1982, when Bismuth first presented a system for classification of biliary injuries, a number of systems have been proposed.
These systems are used to facilitate communication between peers and to better understand the injury, its mechanism and to plan for repair.
The most frequently used and well known classifications are: the Bismuth system, the Strasberg classification system, the Neuhaus classification system and the Hanover classification system.
The latter is the most comprehensive classification, as it considers not only the biliary injury, but also concomitant vascular injuries, which can occur in about 1/3 of patients.
Management of Biliary Injury
Biliary injury can be managed nonoperatively or operatively, in a early or delayed fashion, after a complete characterisation of the injury regarding it’s degree, location and presence of concomitant vascular injury.
Endoscopic management is intended to reduce the pressure gradient through the leak, favoring drainage through the Sphincter of Oddi. This is usually achieved by means of a combination of sphincterotomy and placement of an biliary endoprosthesis.
Surgical management of biliary injury should follow a series of principles: 1st, if an anastomosis is built, it must be tension-free, mucosa-to-mucosa and in an absorbable monofilament suture; 2nd the anastomosis can be done in a Roux-en-Y manner or directly to the adjacent duodenum, provided that the first principle is met; 3rd, it is not recommended to perform a duct-to-duct anastomosis, given the high rate of stenosis.
It may be done in 3 different timetables: immediate (during cholecystectomy), early or delayed, when the diagnosis of the injury is done postoperatively.
When an experienced hepatic surgeon is present, it may be possible to attempt an immediate repair of a complex biliary injury with transection of the bile duct.
The preferred anastomosis is a hepaticojejunostomy, with absorbable monofilament suture, in an Roux-en-Y manner, after confirmation of communication between the left and right side of the liver.
Liver resection may be necessary in Strasberg E4 and E5 injuries.
Prevention of Biliary Injury
The best management of biliary injury is definitely prevention. Although there are many nonmodifiable factors that can predispose to an injury, several methods can help us correctly identify cystic structures, and thus limit injury. These methods are:
the infundibular technique; common duct dissection; critical view of safety; intraoperative cholangiography; and advanced imaging techniques.
When none of the methods described is possible or allows for correct identification of the cystic structures, the surgeon must adopt a strategy to avoid biliary injury, such as aborting the surgery, placing a cholecystostomy tube, or opting for a bail-out procedure.