Choledochal cyst is a disease of unknown origin and is more common in women. The symptoms of choledochal cysts in adults are often atypical, and their comorbidities often make clinical diagnosis difficult. Along with the development of imaging, the diagnosis rate of this disease in adults has increased significantly and is no longer rare in the clinic. Our hospital admitted 21 such patients from January 1988 to January 2008, and we report them as follows.
Clinical data
The group consisted of 5 males and 16 females, aged l8-45 years, with an average age of 28.5 years. The duration of the disease ranged from 3 months to 22 years. According to Todani’s revised Alonso-Lej method of typing [1]; 18 cases of type I, 1 case of type III, 1 case of type IV, and 1 case of type V. The main clinical manifestations: abdominal pain, abdominal mass, and jaundice triad in 5 cases, abdominal pain as the only symptom in 7 cases, pain combined with jaundice in 5 cases, and jaundice only in 4 cases. One case of cystoduodenal anastomosis was performed; one case of cystojejunostomy Roux-Y anastomosis; 18 cases of cystectomy plus common hepatic duct concealment Roux-Y anastomosis, one of which was readmitted for cystectomy plus internal drainage after cystojejunostomy for recurrent biliary duct infection; one case of left hemicolectomy. 21 patients underwent ultrasound examination, 18 cases of CT examination, one case of PTC examination, and 5 cases of ERCP 5 cases were examined.
There were no intraoperative cancer cases, and one postoperative pathology reported severe atypical hyperplasia. There were 2 cases of postoperative biliary fistula, 1 case each of abdominal bleeding and pancreatic fistula, and no surgical death in this group. The follow-up ranged from 3 months to 10 years, with a mean follow-up of 36 months and a follow-up rate of 90%. Three cases had occasional cholangitis, including one case after cystoduodenal anastomosis, one case after simple cystojejunostomy Roux-Y anastomosis, and one case of carcinoma after cystoduodenal anastomosis.
DISCUSSION
I. Diagnosis of adult common bile duct cysts
In 1969, Babitt proposed the concept of “anomalous pancreaticobiliary duct coalescence”, which means that anatomically the bile duct and pancreatic duct converge early outside the duodenal wall and the sphincter of Oddi cannot effectively control the coalescence to produce biliopancreatic reflux. Type III: cystic prolapse of the opening of the common bile duct; Type IV: dilated intra- and extra-hepatic bile ducts; Type V: dilated intrahepatic bile ducts (Caroli disease). Type I is the most common. “Abnormal pancreaticobiliary duct cohesion” is thought to be a risk factor for the pathogenesis of types I and IV and for the combination of bile duct and gallbladder cancers.
Types II and III may be related to excessive bile duct proliferation and vacuolization during embryonic development or to a reduction and absence of ganglion cells in the common bile duct wall [2]. The initial diagnosis of choledochal cysts is often unclear, and their clinical presentation is based on the triad of jaundice, pain, and abdominal mass. However, patients with clinical manifestations of the triad are not common, and there were only 5 cases (23.8%) in our group, with one or two of these symptoms accounting for 76.2% . Choledochal cysts are often accompanied by gallbladder stones or bile duct stones, so they are initially easily diagnosed as acute cholecystitis or acute cholangitis and undergo cholecystectomy or other biliary exploratory surgery. In adults, choledochal cysts are less likely to present as jaundice, but there is a relatively high incidence of cholecystitis, cholangitis and pancreatitis.
Currently, the diagnosis of choledochal cysts is noted to be based on bile duct imaging, including ultrasound, CT, ERCP, PTC, MRCP, etc. To date, there is no specific biochemical index for choledochal cysts themselves. The vast majority of patients with choledochal cysts can be diagnosed clinically by ultrasound, and both ERCP and PTC can provide better bile duct imaging, especially showing the anatomy of the biliopancreatic duct confluence. However, both are invasive examinations that can result in a certain rate of complications. The current gold standard for diagnosis is MRCP, which has the same sensitivity as ERCP, but without the complications of ERCP. Nowadays, the development of multi-row spiral CT technology has greatly improved its accuracy in the diagnosis and treatment of biliary system diseases, and it is not affected by the degree of tissue and organ development and the surrounding combination of overlap and intestinal gas, so it can clearly show the site, morphology, number and extent of congenital common bile duct cysts and whether they are combined with stones.
Selection of extrahepatic choledochal cyst and intraoperative considerations
Once diagnosed, common bile duct cysts should be treated surgically. At present, the surgical method does not advocate the use of simple cystic jejunostomy with internal drainage, because the cyst is not removed, and postoperative complications such as bile and intestinal fluid reflux, anastomotic stenosis, stone formation and cyst malignancy are likely to occur. This procedure fundamentally solves the problem of bile stagnation and cancer, greatly reduces the occurrence of postoperative cholangitis, and at the same time, the normal bile-intestinal anastomosis can prevent anastomotic stenosis and anastomotic fistula to a certain extent, and has been listed as the first choice for the treatment of this disease because of its remarkable clinical efficacy. In our group, 18 patients were treated with this procedure, and no cancer occurred in the postoperative follow-up, and biliary ductitis occasionally occurred.
In adults, choledochal cysts have a long course, and repeated inflammation can thicken the scar around the cyst and make it difficult to peel off because of the close adhesions with portal vein and hepatic artery, so care should be taken to protect the above important vessels during the operation. Similarly, when stripping pancreatic segmental cysts should also be very careful, generally the cysts suddenly become thin before the opening of the pancreatic duct and should be able to be identified during surgery.
A significant portion of this disease has a history of one or several surgeries, serious adhesions of abdominal organs, ectopic, easy damage to the gastrointestinal tract and important blood vessels when exposing the hepatic portal and freeing the cyst, which should be separated layer by layer from right to left close to the dirty surface of the liver, preferring to injure the liver peritoneum rather than the stomach and intestinal ducts up to the level of the hepatoduodenal ligament. As repeated cholangitis and bile duct stones can lead to biliary cirrhosis and portal hypertension, the bile duct wall and connective tissue around the cyst are rich in blood vessels, varices and high pressure, and the coagulation mechanism is impaired due to liver function impairment, so it is easy to bleed during the operation, so the operation should be as close as possible to the cyst wall to reduce the blood leakage from the peeling surface, and the vascular ligation should be reliable and carefully sutured in case of large bleeding to avoid unnecessary damage caused by blind clamping and suturing. The vascular ligation should be reliable and careful suturing should be done in case of large bleeding to avoid unnecessary injury caused by blind clamping and suturing. One case in this group with biliary cirrhosis portal hypertension had more intraoperative blood leakage and still had active bleeding after surgery, and the bleeding was successfully stopped by re-entering the abdomen 10 h after surgery.
III. Management of intrahepatic bile duct cysts
In type IV choledochal cyst, if the intrahepatic lesion is confined to one liver lobe, resection of one liver lobe plus internal drainage of extrahepatic choledochal cyst is feasible. In type V (Caroli disease), lobectomy is also feasible if the lesion is limited. There is still no good solution for type IV and V lesions with scattered foci, and liver transplantation may be the only effective method.
IV. Prevention and treatment of complications
Anastomotic stenosis is the most common complication after internal drainage. If the opening of the upper end of the cyst is higher than the confluence of the left and right hepatic ducts, it is better to cut the middle compartment of the left and right hepatic ducts before the anastomosis and shape the common hepatic duct, and make the anastomosis tension-free to reduce the formation of anastomotic palsy, which generally does not cause stenosis without stent. In case of low opening of the upper end of the cyst and the diameter of the common hepatic duct is less than 0.8 cm, the common hepatic duct should be cut and shaped to place a stent drain for more than 3 months, and a more stable method can be to leave the upper opening of the trumpet-like cyst with the jejunum anastomosis, and for safety reasons the mucosa of the upper opening of the trumpet-like cyst should be peeled off. In conclusion, the anastomosis should be as large as possible under the premise of removing the cyst as much as possible.
On the one hand, pancreatic fistula can be caused by injury to the pancreatic duct when the cyst is removed from the pancreatic segment, and on the other hand, because the opening of the lower end of the cyst is under the opening of the pancreatic duct, inflammation can cause stenosis of the lower end of the common bile duct, and pancreatic fistula can occur after the residual cyst is closed. In one of our cases, the stenosis of the lower end of the common bile duct was seen on intraoperative imaging, the cystic pancreatic segment was preserved, and the mucosa was treated with carbolic acid and interlocked to close the stump, and 100 ml of pancreatic fluid was drained daily after surgery, which was cured after 14 d of antispasmodic and anti-inflammatory treatment. If repeated inflammation of the lower end of the common bile duct scar-like stenosis can cause recalcitrant pancreatic fistula, the residual cyst should be operated again for endojejunal drainage.
Cholangiocarcinoma is the most common malignant complication of cholangiocysts, with about 2.5%-15% reported in the literature. Recurrent infections of the bile duct, pancreatic enzyme stimulation, biliary stasis, and over-concentrated bile acids are considered to be carcinogenic factors. And mutations of immunodeficiency in the cyst wall and adjacent normal bile ducts, such as K-ras and p53, also respond to biliary epithelial malignancy .
Tumors may occur in the cystic wall or in areas where the intra- and extrahepatic bile ducts are not dilated, and the incidence of bile duct cancer in such patients is 120 times higher than in normal subjects, and the risk of carcinogenesis increases significantly with age, with the average age of patients with bile duct cancer originating from bile duct cysts reported in the literature to be about 32 years [5]. However, there is no effective treatment for Caroli’s disease and type IV choledochal cysts with scattered lesions, which should be followed up closely and liver transplantation is feasible when conditions are ripe. In patients with existing biliary cirrhosis and portal hypertension, especially those with poor general condition with hypoproteinemia and impaired coagulation mechanism, attention must be paid to perioperative management to reduce the morbidity of complications and surgical mortality.