Minimally Invasive Approach to Choledocholithiasis
The incidence of choledocholithiasis in patients undergoing cholecystectomy is estimated to be 10 %. The presence of common bile duct stones is associated with several known complications including cholangitis, gallstone pancreatitis, obstructive jaundice, and hepatic abscess. Making the diagnosis early and prompt management is crucial. Traditionally, when choledocholithiasis is identified with intraoperative cholangiography during the cholecystectomy, it has been managed surgically by open choledochotomy and place- ment of a T-tube. This open surgical approach has a morbidity rate of 10–15 %, mortality rate of <1 %, with a <6 % incidence of retained stones. Patients who fail endoscopic retrieval of CBD stones, as well as cases in which an endoscopic approach is not appropriate, should be explored surgically.
Acute obstruction of the bile duct by a stone causes a rapid distension of the biliary tree and activation of local pain fibers. Pain is the most common presenting symptom for choledocholithiasis and is localized to either the right upper quadrant or to the epigastrium. The obstruction will also cause bile stasis which is a risk factor for bacterial over- growth. The bacteria may originate from the duodenum or the stone itself. The combination of biliary obstruction and colo- nization of the biliary tree will lead to the development of fevers, the second most common presenting symptom of cho- ledocholithiasis. Biliary obstruction, if unrelieved, will lead to jaundice. When these three symptoms (pain, fever, and jaundice) are found simultaneously, it is known as Charcot’s triad. This triad suggests the diagnosis of acute ascending cholangitis, a potentially life-threatening condition. If not treated promptly, this can lead to hypotension and decreased metal status, both signs of severe sepsis. When combined with Charcot’s triad, this constellation of symptoms is commonly referred to as Reynolds pentad.
Laparoscopic common bile duct exploration
Laparoscopic common bile duct exploration (LCBDE) allows for single stage treatment of gallstone disease, reducing overall hospital stay, improving safety and cost-effectiveness when compared to the two-stage approach of ERCP and laparoscopic cholecystectomy. Bile duct clearance can be confirmed by direct visualization with a choledochoscope. But, before the advent of choledochoscope, bile duct clearance was uncertain, and blind instrumentation of the duct resulted in accentuated edema and inflammation. Due to advancement in instruments, optical magnification, and direct visualization, laparoscopic exploration of the CBD results in fewer traumas to the bile duct. This has led to an increasing tendency to close the duct primarily, reducing the need for placement of T-tubes. Still, laparoscopic bile duct exploration is being done in only a few centers. Apart from the need for special instruments, there is also a significant learning curve to acquire expertise to be able to perform a laparoscopic bile duct surgery.
Morbidity and mortality rates of laparoscopic exploration are comparable to ERCP (2–17 and 1–5 %), and there is no clear difference in primary success rates between the two approaches. However, the endoscopic approach may be preferable for elderly and frail patients, who are at higher risk with surgery. Patients older than 70–80 years of age have a 4–10 % mortality rate with open duct exploration. It may be as high as 20 % in elderly patients undergoing urgent procedures. In comparison, advanced age and comor- bidities do not have a significant impact on overall complication rates for ERCP. A success rate of over 90 % has been reported with laparoscopic CBD exploration. Availability of surgical expertise and appropriate equipment affect the success rate of laparoscopic exploration, as does the size, number of the CBD stones, as well as biliary anatomy. Over the years, laparoscopic exploration has become efficient, safe, and cost effective. Complications include CBD laceration, stricture formation, bile leak, abscess, pancreatitis, and retained stones.
In cases of failure of laparoscopic CBD exploration, a guidewire or stent can be passed through the cystic duct, common bile duct, and through the ampulla into the duodenum followed by cholecystectomy. This makes the identification and cannulation of the ampulla easier during the post- operative ERCP. Laparoscopic common bile duct exploration is traditionally performed through a transcystic or transductal approach. The transcystic approach is appropriate under certain circumstances. These include a small stone (<10 mm) located in the CBD, presence of small common bile duct (<6 mm), or if there is poor access to the common duct. The transductal approach is preferable in cases of large stones, stones in proximal ducts (hepatic ducts), large occluding stones in a large duct, presence of multiple stones, or if the cystic duct is small (<4 mm) or tortuous. Contraindications for laparoscopic approach include lack of training, and severe inflammation in the porta hepatis making the exploration difficult and risky.
With advancement in imaging technology, laparoscopic and endoscopic techniques, management of common bile duct stone has changed drasti- cally in recent years. This has made the treatment of this condition safe and more efficient. Many options are now available to manage this condition, and any particular modality for treatment should be chosen carefully based on the patient related factors, institutional protocol, available expertise, resources, and cost-effectiveness.