Approach Considerations
Total excision of the cyst with adequate bile drainage is the standard treatment for choledochal cyst. [49] However, in the setting of extensive inflammation, a cyst mucosectomy and cystoenterostomy can be performed.
The treatment of choledochal cyst is typically complete surgical excision at the time of presentation, with the exception of type V (multiple intrahepatic cysts) which may benefit from conservative therapy including percutaneous drainage and medical management.
Surgical Therapy
Treatment of choledochal cysts is surgical, except for type V multiple intrahepatic cysts, which can benefit from medical management for variable periods of time.
In the past, operative aspiration and external drainage were used extensively because most patients were quite sick, and a simple quick procedure was convenient. These external drainage procedures of the biliary tree were unsuccessful because of numerous complications, including repeated cholangitis and biliary fistulae. Mortality was high. [16, 50, 51, 31, 5, 13] Today, in the setting of acute severe disease, percutaneous cholecystostomy drainage can be performed before the definitive procedure. This is safe and generally well tolerated; however, it is not necessary in most patients.
Internal drainage, either with cystoduodenostomy or cystojejunostomy with Roux-en-Y biliary reconstruction, was used in the past. These procedures left the cyst behind, and the free reflux of pancreatic enzymes into the cyst via the anomalous pancreaticobiliary junction resulted in a high incidence of calculi, recurrent cholangitis, anastomotic strictures, and carcinoma arising from the cyst. [12] Of patients treated with either cystoduodenostomy or cystojejunostomy, 65% remained symptomatic, and 40% required repeat surgery at a later date. [52, 53] Recurrent cholangitis and chronic inflammation in the remaining cyst eventually produces metaplasia that leads to malignant transformation.
Total excision of the cyst in types I, II, and IV followed by reconstruction of the biliary tree with hepaticojejunostomy in a Roux-en-Y fashion has been widely accepted as the procedure of choice in treating choledochal cysts and has been found to be superior to hepaticoduodenostomy. [54] This procedure implies excision of the distal common bile duct (CBD). Consequently, it blocks the reflux of pancreatic enzymes into the biliary tract, thereby decreasing the incidence of carcinoma of the bile duct.
Total excision of the cyst is possible in virtually all infants and young children. In older patients with repeated cholangitis and marked pericystic inflammation, this disease may be best managed with resection of the anterolateral part of the cyst followed by an endocystic resection of the lining, leaving the back wall adjacent to the portal vein in place, as reported by Lilly in 1977. [55] This technique also appears to be most useful in patients who have previously undergone cystoenterostomy and who require repeat surgery because of recurrent cholangitis. This technique makes the dissection less hazardous.
Several groups have successfully performed laparoscopic-assisted and laparoscopic total cyst excision with Roux-en-Y hepatoenterostomy with complication rates comparable to those of the open procedure. [56, 57] Robotic excision has been described as well. [58, 59]
Li et al performed laparoscopic cyst excision with laparoscopic-assisted Roux-en-Y hepatoenterostomy in 35 children (33 cyst type, two fusiform) without conversion to the open procedure and with postoperative stays of 3-5 days. [60, 61, 62] The procedure was described in detail for both choledochal cyst and biliary atresia surgery by Martinez-Ferro et al in 2005. [63] Liuming et al [64] and Liem et al [65] also concluded that laparoscopic excision was as safe as open excision.
Intraoperative cholangiography obtained via puncture of the cyst or via the gallbladder is always obtained. It outlines the exact anatomy of the choledochal cyst and its relationship with the pancreas. Cholecystectomy is routinely performed at the same time.
Biliary reconstruction can be performed with a Roux-en-Y hepaticojejunostomy as high as possible, near the hilum of the liver. [66, 51, 31, 29] Some authors, including Raffensperger and Shamberger, have interposed a reversed segment of jejunum to prevent reflux. [67, 68, 8] This idea has not been universally accepted. No stents are routinely necessary.
With regard to type II choledochal cysts, a simple excision of the diverticulum with ductoplasty for reconstruction of the CBD is all that is required. Laparoscopic excision has been successfully performed in this rather rare disease. [69, 70]
With type III choledochal cysts, the general approach is one of lateral duodenotomy with unroofing of the choledochocele to drain the bile duct and pancreatic duct directly into the duodenum. The two ductal openings should be carefully examined to determine whether ductoplasty is required. [51, 27, 71]
In patients with type IV choledochal cysts with intrahepatic cysts, each case is individually evaluated, and the principle of adequate bile drainage is taken into account. Excision of the dilated extrahepatic bile ducts as far as the porta hepatis, with hepaticojejunostomy at the level of the hilum, may provide good biliary drainage and effective decompression of the intrahepatic cysts. If the intrahepatic cysts are localized in a small portion of the liver, partial hepatectomy may be required. [72, 73, 21]
With regard to type V choledochal cysts, patients with localized disease may benefit from a hepatic lobectomy. If the disease is diffuse, involving both lobes of the liver, treatment is palliative and liver transplantation may be required. [51, 13, 74, 26]
Complications
Complications after surgery have been mainly observed with types I, IV, and V choledochal cysts. They are much less common in excisional procedures. The overall morbidity is less than 10%. Mortality and repeat surgery rates are low after excision, compared with the rates associated with internal drainage operations.
Cholangitis
In 1996, Miyano et al reported a 2.3% incidence of cholangitis after cyst excision. [29] In 1995, Todani et al found cholangitis in 10 patients in their 25-year review of 97 patients who underwent cyst excision. [35] In contrast, Chijiiwa et al (in 1993 and 1994) found that 88% of patients who previously underwent cystoenterostomy had cholangitis. [52, 53]
Biliary stone formation
In 1993 and 1994, Chijiiwa et al reported a 25% rate of choledocholithiasis and a 33% rate of hepatolithiasis after cystoenterostomy. [52, 53] In 1997, Yamataka et al reported stone formation in three of 18 patients who underwent previous cyst excision. [75] Two patients had stones at the porta hepatis, and one patient had stones at both the porta hepatis and within the left hemiliver.
Stones can be observed in the intrapancreatic bile duct. Usually, cholangitis and stone formation are observed in the same patient. These complications are thought to result from many factors, including the following:
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Stricture of the anastomosis
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Residual debris in the intrahepatic bile duct
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Dilated intrahepatic ducts, especially in type IV and type V choledochal cysts
Anastomotic stricture
Apart from technical errors, anastomotic strictures may be a progressive phenomenon after surgery. In a 1993 report, Hata et al found a 4.1% rate of anastomotic strictures. [66]
The diameter of an adequate anastomosis is usually reduced by 20-30% after a few weeks. Such a reduction in the anastomotic diameter may result from excessive devascularization of the duct during dissection. A wide anastomosis as far as the hepatic hilum may prevent anastomotic stricture.
Residual debris in intrahepatic bile ducts
Residual debris is commonly observed in older patients. Debris left within the intrahepatic duct or pancreatic duct during cyst excision may be responsible for postexcisional stone formation and pancreatitis. [53, 51, 72, 36, 76]
Intrahepatic bile duct dilatation
Dilatation usually regresses after cyst excision and hepaticojejunostomy in young patients. In older patients and adults, this dilatation tends to persist. Dilatation and residual debris may cause cholangitis and stone formation. [72, 73] Some authors have recommended endoscopic examination of the duct during surgery to clean out all the debris. [77, 78]
Malignancy
Malignancies in choledochal cyst can arise from the distal CBD, the wall of the cyst (even after successful drainage at cystoenterostomy), or the intrahepatic bile ducts. Any type of cyst is susceptible to malignancy, but the greatest prevalence is observed with types I, IV, and V. Factors thought to contribute to the development of malignancy include prolonged bile stasis and chronic inflammation of the cyst wall.
The risk of cancer appears to be related to the age of the patient. [15, 79, 80, 13, 2, 81, 82, 83] Inflammatory and metaplastic changes increase with patient age, and they are frequently observed in association with carcinoma of the bile duct. The increased risk of biliary tract malignancy, even after surgery, warrants close surveillance in any case of choledochal cyst.
More than half of the cancers arise from the cyst wall, even after successful internal drainage. The risk of carcinoma in the retained cyst approaches 50% in patients treated with cystoenterostomy and is approximately 20 times greater than in the general population. [15, 53, 51, 82] With regard to intrahepatic ducts, adequate bile drainage may prevent malignant transformation.
Total cyst excision had been promising in eliminating the risk of cancer development. However, sporadic cases of carcinoma in the intrahepatic ducts and distal common duct after complete cyst excision have been reported. [72, 84] Malignancy can develop many years after excision of the cyst and can develop in areas of the biliary tree remote from the cyst, such as the gallbladder and terminal common duct, which is left behind after excisional surgery.
The risk of detecting a biliary tree malignancy in a resected cyst is 0.7% in patients who undergo surgery before age 10 years, 6.8% in patients who undergo surgery at age 11-20 years, and 14.3% in patients who undergo surgery after age 20 years.
In a 1997 report, Yamataka et al recommended excision of the intrapancreatic terminal choledochus. [75]
Long-Term Monitoring
Long-term follow-up is necessary to detect any late complications, especially the development of malignancy.
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Todani classification of the 5 types of choledochal cysts.
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Anomalous pancreaticobiliary ductal system theory of choledochal cyst etiology. From Babbitt DP. [Congenital choledochal cysts: new etiological concept based on anomalous relationships of the common bile duct and pancreatic bulb]. Ann Radiol (Paris). 1969;12(3):231-40.
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Photomicrograph shows the cyst wall, with inflammation and ulceration of the mucosa and submucosa.
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Media file shows the wall of the cyst, with inflammation and metaplasia.
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Ultrasonogram shows a large unilocular cyst under the liver.
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Magnetic resonance cholangiopancreatography shows dilated hepatic ducts and common bile duct (CBD) of a type IV cyst.
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CT scan shows a large cyst with wall thickening.
