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Choledochal cysts are commonly associated with pancreatico-biliary malunion, which is widely accepted as the underlying anatomical reason for bile / pancreatic reflux leading to cyst formation, recurrent cholangitis and pancreatitis. The textbook description of presentation of a choledochal cyst is the classical triad of pain, right hypochondrial mass and jaundice. But there is now an increasing group of asymptomatic patients diagnosed on antenatal scanning. In addition, some children are diagnosed on screening ultrasound in the investigation of non-specific recurrent abdominal pain.
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Complete excision of the cyst with bilio-enteric reconstruction is the treatment of choice. Early experience with hepaticoduodenal reconstruction was associated with significant bile gastritis and most surgeons prefer the Roux-en-Y hepaticojejunostomy for bilio-enteric reconstruction of choledochal cyst. Important issues in surgery for choledochal cyst are:
1) Completeness of cyst excision,
2) Leakproof anastomosis.
In cases where there had been recurrent inflammation causing such dense adhesions that complete resection is impossible, posterior mucosectomy had been described which aims to remove all epithelial tissue to minimise the risk of cholangiocarcinoma, yet sparing the treacherous separation between the posterior cyst wall from the portal vein. A 40cm Roux limb has traditionally been used as the optimal length to prevent post-operative cholangitis. Conventional treatment for choledochal cyst is by open surgery that requires a sizeable subcostal or transverse incision. With minimally invasive surgery finding ever increasing applications in Paediatric Surgery, it has now been shown that choledochal cysts can also be treated laparoscopically.
Laparoscopic excision of choledochal cyst was first described more than a decade ago. However, its popularity was slow to take off, as it was a technically demanding procedure involving intracorporeal suturing of an important anastomosis. Significant dexterity is required. In cases with much inflammation, dissection of the cyst from the surrounding hepatic artery and portal vein can be arduous with significant oozing. Laparoscopy yields a much better visualisation of structures, but the limits imposed by a few working ports rather than a large open incision means the dissection proceeds more slowly, and patience, a necessary ingredient for success.
In 2007, KK Women’s and Children’s Hospital performed its first case of laparoscopic choledochal cyst excision when Visiting Professor Klas Bax, an eminent paediatric surgeon from the Netherlands, came on an HMDP visit. Since then, the team at KKH has gone on to perform 5 more cases, with 1 conversion. All of these were the typical Todani Type 1 choledochal cysts, without intrahepatic cystic involvement. The youngest of these was a 6 month old. These cases form the first series in Singapore.
Figure 1 shows a typical operative picture of a Choledochal Cyst while Figure 2 shows the laparoscopic approach.
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While cosmesis is an important consideration for parents and the child about to grow into his/her image-conscious teenage years, there are other benefits increasingly recognised in laparoscopic surgery. These include decreased physiological stress responses with minimal access, decreased analgesic requirements, faster recovery and shorter hospitalisation. In particular, open incisions in the upper abdomen can lead to respiratory complications with inadequate pain management, and minimal access surgery minimises that. For abdominal operations, minimal access is associated with decreased adhesions.
The most feared early complication is that of anastomotic dehiscence. This may lead to bile peritonitis, sepsis, prolonged drainage, re-do surgery and in the longer term, anastomotic stricturing which may cause recurrent cholangitis, stones and even the late occurrence of cholangiocarcinoma. All of our 6 patients who successfully underwent laparoscopic choledochal cyst excision recovered uneventfully, with early feeding and minimal analgesic requirements. There were no early anastomotic complications.
The key weakness currently is the prolonged time required for the operation to be done laparoscopically, taking 1.5 to 2 times what would have been required of an open operation. However, this is in part due to the necessary “learning curve” with any new procedure. Operating time will decrease with improved technical modifications and increased experience. In laparoscopic surgery, teamwork is key, and a competent team
comprising the operator, assistant and nurses familiar with laparoscopic surgery is absolutely essential to the success of the operation.
As with open surgery for choledochal cysts, all of these children need continued long-term surveillance.
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