Bile duct Reconstruction in Liver Transplant Web view Complications from bile duct reconstruction...
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Bile duct Reconstruction in Liver Transplant Surgery
Bile Duct Reconstruction in Liver Transplant Surgery
Adeel S Khan MD, Jeffrey Campsen MD, Goran B Klintmalm MD.
Complications from bile duct reconstruction are a major source of morbidity, graft loss and even death in the liver transplant patient.2-5 The integrity of the anastomosis is highly dependent on surgical technique. However, there are variations in bile duct anatomy and the vascular supply that make this a particularly challenging aspect of liver transplant surgery. Surgeons have therefore developed several techniques of biliary reconstruction. To date, there is still considerable debate on which technique is best suited to a particular anatomic bile duct variant. The purpose of this review is to outline the basic knowledge and controversial topics that influence which type of reconstruction is used during liver transplant surgery. We will review the anatomy of the biliary system and the common techniques of reconstruction. The pros and cons of each technique are reviewed.
Bile Duct Anatomy The common hepatic duct (CHD) is formed by the union of the right and left hepatic ducts in most patients. In most adults, the CHD duct is 6-8 cm long and approximately 6 mm in diameter. The hepatic artery lies medial to and the portal vein posterior-medial to the bile duct as it exits the liver. Together these three structures form the portal triad. There are common variations in this anatomical pattern including absence of the right or left hepatic duct. In addition there can also be multiple sectoral or accessory ducts entering the right and/or left hepatic ducts at different levels as they exit the liver. 1,2
The cystic duct drains the gallbladder and then joins the CHD in a highly variable position to form the common bile duct (CBD). The duct travels through the head of the pancreas before it empties into the duodenum (Image 1). The blood supply to the bile ducts comes from vessels running laterally at 3’o clock and 9’o clock position and is mainly derived from the gastroduodenal artery (GDA) and right hepatic artery (RHA).1 However, there is considerable variation in the blood supply and it is not uncommon to find vessels from the cystic and gastric arteries or the celiac axis that supply the biliary tree. During liver transplant surgery the bile duct is transected and reconstructed at the level of the CHD. Consequently the blood supply to the divided donor duct is far more tenuous than the recipient’s.
Type of Anastomosis
Bile duct reconstruction during liver transplantation is usually performed by an end to end anastomosis (choledocho-choledochostomy [DD]) between the donor and recipient common bile ducts. The next most common technique is an end to side Roux-en-Y hepaticojejunostomy (RYHJ).4-7, 12-14 In the latter procedure, the end of the hepatic duct is anastomosed to the side of the jejunum. Direct insertion of the common bile duct into the duodenum known as choledocho-duodenostomy (CD) is a third but less common option for biliary reconstruction.9
Duct-to-Duct Anastomosis (DD) (Choledochocholedochostomy): The common bile ducts of the donor and recipient can be anastomosed as an end-to-end choledocho-choledochostomy. This is the technique of choice for biliary anastomosis in deceased donor liver transplantation (DDLT). It is a technically easier and faster procedure than a RYHJ. The DD also avoids intestinal manipulation, maintains anti-reflux mechanism of sphincter of Oddi and provides easy access for endoscopic intervention in case of future anastomotic strictures.7,8,10,17 The anastomosis itself can be performed using interrupted or running mono-filament (absorbable or non absorbable) suture. It can be technically challenging if the ducts are very small or if there is a large size discrepancy between donor and recipient bile ducts. The latter issue is particularly important in pediatric liver transplantation.
The most expeditious way to address the donor and recipient duct size discrepancy is to make a side-cut on the side of the smaller duct (usually donor side). With very large ducts a choledochoplasty of the oversized duct can be performed. Neuhaus et al from Germany described a technique of side-to-side anastomosis between the donor and recipient common bile ducts (choledocho-choledochostomy) instead of the more common end to end method. Studies have shown that this is as safe option for performing bile duct anastomosis and has a low complication rate.14
Roux-en-Y hepaticojejunostomy (RYHJ): In this technique, a loop of small bowel 10-20 cm distal to the ligament of Treitz is divided and brought up to the donor bile duct. An end to side anastomosis is then completed between the two (Image 2). The RYHJ is a preferred technique when the donor bile duct diameter is small (pediatric, split liver and living donor transplants) and in patients with extrahepatic biliary disease (eg. primary sclerosing cholangitis, Caroli’s disease and cholangio-carcinoma).
There are unique complications associated with type of biliary reconstruction that are related to the surgical enteric anastomosis. This approach adds to the operative time because it involves small bowel resection and anastomosis. In addition, there is an increase the risk of peritonitis due to enteric leaks and bleeding complications. These complications are exacerbated by the high venous pressure associated with portal hypertension in some patients. There is also an increase the risk of developing ascending cholangitis from contamination with gut flora. Further, subsequent endoscopic intervention to treat bile duct narrowing is difficult if not impossible.7,8,10,12,17,22
Choledochoduodenostomy (CD): This technique involves direct anastomosis between the end of the bile duct and the side of the duodenum. The CD has been shown in a several studies to be a safe alternative to a Roux-en-Y when a duct-to-duct anastomosis cannot be performed.9 Advantages include the ease of postoperative access to the biliary system. However this type of anastomosis may expose the biliary system to enteric contents raising the risk of ascending cholangitis. (Image 3)
Role of T-tube/stenting
Insertion of biliary drainage catheters or T-tubes has been a topic of controversy in the transplant community. The rationale for using T-tubes includes the ease of access to the biliary system and protecting the anastomosis against narrowing by the insertion of an internal stent. In addition, the T-tubes allow physicians to monitor the quality of the bile and thus the function of the liver graft which can provide critical information in cases of primary non-function. It also allows endoscopic access to bile ducts to diagnose or repair a stenosis or leak. Some investigators think that T-tubes may protect the anastomosis from developing leaks by lowering the intra-ductal pressure.7
However initial randomized trials that examined the safety of T-tubes in liver transplant recipients showed that biliary complications occurred in up to 50% of patients.11-15 These complications included narrowing of the bile duct lumen, cholangitis, spontaneous dislodgement of the T-tube, and bile leaks following T-tube removal. These complications seem to be caused by impaired healing due to immunosuppression. Spasm of sphincter of Oddi is also thought to occur more frequently in patients with T-tubes. These findings discouraged transplant surgeons from using T-tubes and a recent meta-analysis confirmed this observation by demonstrating that most of the larger transplant centers now avoid the use of T-tubes in cadaveric liver transplants.15
Bile duct reconstruction in living donor liver transplantation
Living donor liver transplantation (LDLT) is an accepted option to increase the donor organ pool 16,17,19,20. The long term outcomes are comparable to deceased donor liver transplants. 23. Both the right and left hemi-liver are used in adult to adult living donation surgery. In contrast, the left lateral section (segments 2 and 3) is commonly used when an adult donates to a pediatric patient.
The biliary reconstruction in LDLT patients tends to be more challenging than in cadaveric liver transplants because the ducts are smaller and can have multiple or irregular branching depending on the plane of transection. 17 Roux-en-Y hepaticojejunostomy (RYHJ) was considered the standard approach for LDLT biliary reconstruction until 1998 when Wachs et al reported the first case of duct-to-duct reconstruction for right hemi liver transplant. 16 Since then several studies have reported good outcomes using duct-to-duct biliary anastomosis for LDLT. 17,19,20
A single hepatic duct is favored for a DD anastomosis. If two ducts are present, a DD anastomosis can still be used if the openings are less than 3 mm apart. In this case, the duct is modified to create a single orifice. If the distance is greater than 3 mm then two separate hepaticojejunostomies are performed using a Roux-en-Y loop. 5 In 2005 Asonuma et al. described using the recipient cystic duct for biliary reconstruction in right liver donor transplantation when two bile duct orifices were present. 24
The advantages and disadvantages of using the different biliary reconstruction techniques are similar to those for deceased donor liver transplant as described above however, the outcomes in LDLT recipients are not as good due to higher rates of biliary complications seen with LDLT (see complications). The use of biliary drainage catheter or T-tube in LDLT is as controversial as their use in DDTL. Overall, T-tubes are rarely used in LDLT. 5,12,13,14,17
Complications of bile duct reconstruction
Calne in 1976 described the biliary anastomosis as the “Achilles heel”