Laparoscopic management of type VI choledochal cyst with common bile duct stone: report of a case and review of literature

Abstract

A young adult male presented with biliary colic and intermittent jaundice for 1 year. Abdomen findings were unremarkable. Routine investigations revealed a raised total bilirubin. On abdominal ultrasonography, common bile duct (CBD) dilatation with multiple stones was noted. On further imaging with magnetic resonance cholangiopancreatography, type I choledochal cyst (CDC) was suspected. A laparoscopic approach was planned. Intraoperatively, dilatation of cystic duct was noted which constitute type VI CDC. Partial malrotation of the gut and accessory right hepatic artery were also noted as incidental finding. Laparoscopic cholecystectomy with CBD exploration and removal of stones, biliary stent placement, cystic duct cyst excision and primary repair of CBD was done. Postoperatively, the patient improved symptomatically with a fall in bilirubin to normal range. We are describing the laparoscopic management of a rare case of type IV CDC which was diagnosed intraoperatively.

Background

Choledochal cysts (CDCs) are congenital cystic dilatations of extrahepatic bile ducts with or without dilatation of intrahepatic ducts. Though incidence is common in younger age, 20%–25% of cases are diagnosed in adulthood.¹ Conventionally, five categories of CDCs are given by Todani et al.² Type VI CDC, described first in literature by Serradel et al constitutes a separate entity.³ This includes fusiform or saccular dilatation of the cystic duct. Type VI CDC is reported in the literature with increased frequency in the last two decades. Though the rarest type among all CDC, they pose a challenge in the diagnosis and management. They are least detected in the preoperative period and are associated with biliary and vascular anomalies as in all other variants. We describe case of type VI CDC with associated anomalies managed laparoscopically.

Case presentation

A 20-year-old man presented to our outpatient department with complaints of abdominal pain in the right upper quadrant and jaundice for 1 year. Abdominal pain was colicky in nature associated with intermittent jaundice. There was no history of abdominal mass, fever, chills, steatorrhoea or generalised itching. There was a history of previous hospitalisation for similar complaints and improvement with analgesics and antibiotics; but no history of any previous endoscopic intervention. On examination, he was icteric, afebrile and vital parameters were in the normal range. Abdominal examination was unremarkable.

Investigations

Routine blood investigations showed raised total bilirubin 1.58 mg/dL (normal range: 0.3–1 mg/dL) with direct hyperbilirubinaemia 0.61 mg/dL (normal range <0.20 mg/dL). Serum transaminases and alkaline phosphatase levels were normal. Transabdominal ultrasonography showed a normal gallbladder with no calculi, hepatomegaly, bilateral intrahepatic biliary duct dilatation and dilated CBD (9 mm) with multiple calculi; the largest measuring 17 mm. Magnetic resonance cholangiopancreatography (MRCP) was discussed with the radiology team, which revealed choledocholithiasis with stones in the cystic duct together with suspicion of type I CDC (figure 1). Endoscopic retrograde cholangiopancreatography (ERCP) was not attempted due to the presence of a large common bile duct (CBD) stone.

Figure 1.

Magnetic resonance cholangiopancreatography image showing dilated common bile duct with multiple stones, gallbladder (white arrow) and cystic duct stone (blue arrow).

Differential diagnosis

With the recurrent symptoms of biliary colic and intermittent jaundice and ultrasound showing multiple CBD calculi, chronic cholecystitis with choledocholithiasis was the first differential diagnosis. Another clinical possibility was Mirizzi syndrome. However, MRCP findings resembling type I CDC supported the previous differential diagnosis.

Treatment

Laparoscopic cholecystectomy with CBD exploration was planned. Standard laparoscopic ports were placed. During surgical procedure, partial malrotation of the gut was noted with small bowel occupying the right quadrant and appendix and the remaining colon occupying the left quadrant. The liver surface appeared normal. Calot’s triangle was dissected. The cystic artery and the cystic duct were dissected, ligated and cut. Saccular dilatation of cystic duct filled with stones was noted near its insertion to CBD (figure 2). Choledochotomy was done using a harmonic scalpel. A narrow Cystic duct opening into CBD was visualised and a nephroscope was inserted. Proximal CBD and hepatic ducts were free of stones after flushing. Visualised distal CBD showed impacted stones. Stones were retrieved through forceps and CBD was cleared of stones and a 10Fr internal CBD Stent was placed. The cyst wall was completely excised. Choledochotomy was closed with 3–0 Polydioxanone suture by interrupted technique. The gallbladder was dissected from the bed and the specimen removed. No bile leak was noted and a single hemovac suction drain was placed. As the gut malrotation was asymptomatic no intervention was undertaken for this. At last, the port sites were closed.

Figure 2.

Cystic duct dilatation (white arrow) with common bile duct (black arrow).

Outcome and follow-up

Postoperatively, the patient was asymptomatic except for two episodes of malena on day 2; CT angiography was done and no source of bleed or abnormality was found except for the incidental observation of accessory right hepatic artery arising from superior mesenteric artery (figure 3) and the partial malrotation of the gut was also confirmed in the imaging (figure 4). The patient improved symptomatically with conservative treatment. Postoperatively total bilirubin decreased to 1.2 mg/dL on day 3 and 0.7 mg/dL on day 5, and he was discharged on postoperative day 6. The histopathological examination of the gallbladder specimen showed cholesterosis with chronic follicular cholecystitis. The excised specimen showed thick collagenous tissue fragment consistent with features of CDC. No dysplasia or malignancy was noted.

Figure 3.

Black arrow showing accessory right hepatic artery arising from the superior mesenteric artery.

Figure 4.

Black arrow showing small and large bowel occupying right and left quadrant respectively; red arrow pointing duodenum D3 not crossing midline suggesting partial malrotation.

Discussion

CDCs are extrahepatic or intrahepatic dilatation of biliary ducts. Incidence in the Asian population is 1:1000 with a female preponderance.¹ As in this case, 20% of CDCs are diagnosed in adulthood. CDCs are classified into five categories by Todani et al.² However, his classification does not include an isolated cystic duct cyst. A literature search revealed 20 cases of isolated cystic duct dilatation.^{4 5} In 1983, Bode and Aust reported the first case of a cystic duct cyst who had presented with cholangitis.⁶ Serradel et al proposed classifying these cysts as a separate entity and modified the widely accepted and used classification of Alonso Lej which was modified by Todani et al to include cystic duct cysts as type VI CDC.³

Type VI CDCs are the rarest of all CDCs. Proposed pathophysiology includes distal obstruction, weakness of biliary duct wall and an abnormal pancreaticobiliary duct junction (APBDJ) leading to the formation of these cysts.^{5 6} In adults, CDCs are associated with hepatobiliary pathology in a predominant number of cases. Adults with CDCs are likely to have symptomatic gallstones (45%–70%) or acute cholecystitis attributed to biliary stasis.⁷ The most common symptom of cystic duct cyst includes abdominal pain and palpable mass in cases of large cysts. In our case, biliary colic and intermittent jaundice are attributed to CBD stone. In most of the reported cases of type VI CDC, the diagnosis was made intraoperatively,^{4 5} as described here. The preoperative diagnosis made in most of the reported cases was type II CDC.⁸ MRCP is a useful, non-invasive tool with overall good accuracy in the detection and classification of CDCs.⁹ Radiologic abnormalities that are specific to type VI CDC include dilatation and squaring of the cystic duct, acute angulation of the common hepatic duct (CHD) and cystic duct junction with a distinct plane present between the dilated cystic duct and CHD, a normal or wide (Mirrizi’s syndrome) opening of the cystic duct to the CBD, a normal CBD and associated APBDJ.¹⁰ Two of the abovementioned features were observed in our case on retrospective evaluation of imaging. ERCP is invasive, carries the risk of pancreatitis and provides the same information as MRCP thus MRCP is preferred.

Coexisting biliary and vascular anomalies have been reported in 25% of patients with different variants of CDCs with 8% showing aberrant right hepatic artery.¹¹ Association with accessory hepatic artery and intestinal malrotation with type VI CDC has not been reported so far, suggesting this is the first description of these associated findings. Anticipating these anomalies with additional imaging of contrast-enhanced CT abdomen in the preoperative period prevents inadvertent injury to these structures and helps in planning appropriate procedures.

Management of type VI CDC has evolved. Depends on associated hepatobiliary pathology along with morphology of cystic duct opening into CBD. Bresciani et al,¹² Chan et al¹³ and Ray et al⁴ have reported on the laparoscopic management of cystic duct cysts. It is evident in the literature that type VI CDCs can be managed safely by laparoscopic technique. The most common surgery performed is laparoscopic cholecystectomy with cystic duct cyst excision because the malignant transformation of biliary epithelium in these cysts is of concern with an overall incidence of 10%–30%.¹⁴ The surgery recommended for type VI CDC with a narrow-based cystic duct stalk as in this case is laparoscopic cholecystectomy with complete cyst excision. Wide-based cystic duct opening to the CBD warrants bilioenteric reconstruction such as haepaticojejunostomy, haepaticoduodenostomy or choledochal jejunostomy along with cholecystectomy and cyst excision.¹³ Differentiating type VI CDCs from other variants is emphasised by Bresciani et al, wherein applying intraoperative cholangiogram helps in the detailed understanding of biliary anatomy in doubtful cases.¹² In asymptomatic patients with incidentally detected malrotation, intervention does not provide additional benefit over observation.^{15 16} Considering the asymptomatic status of the patient with no evidence of bowel dilatation, gangrene or volvulus intraoperatively; no active intervention was undertaken for the malrotation.

Patient’s perspective.

I feel relieved from fear of sever pain in my tummy. Relief from itching and appetite regain make me feel comfortable.

Learning points.

• Type VI choledochal cysts (CDCs) should be considered as a differential in cases with doubtful cystic duct anatomy with hepatobiliary pathology.

• Though it resembles other CDCs, knowledge of typical radiological features in magnetic resonance cholangiopancreatography prevents preoperative misdiagnosis.

• Anticipation of associated biliary and vascular anomalies with additional contrast-enhanced CT abdomen imaging in these cases prevents inadvertent injury to significant structures.

• Laparoscopic management of these cysts is safe and feasible.

Ethics statements

Patient consent for publication

Consent obtained directly from the patient.