Occult cysto-biliary communication: A forgotten complication of hepatic hydatidosis.

Sir,

A 6-year-old male child presented with pain and lump in the right upper abdomen for 2-3 months. The patient underwent ultrasound and computed tomography scan of the abdomen and was diagnosed to have a single hepatic hydatid cyst, 15 cm × 12 cm in size occupying the middle and left lobe of the liver [Figure 1]. Preoperative investigations revealed an elevated serum alkaline phosphatase (SAP-347 U/L) and eosinophil count (11%). Total serum bilirubin (0.7 mg %) and gamma-glutamyl transferase (28 U/L) levels were normal. The Patient underwent laparotomy for removal of the cyst. Intra-operatively, after removal of the cyst, no cysto-biliary communication (CBC) was seen. This was confirmed by packing the cavity with white gauze piece for a few minutes and observing for the bile staining. There was no staining of the gauze piece; however, in view of the large hydatid cyst, a drain was kept inside the cyst cavity before closure of the abdomen. The drain showed bile leakage from the 2nd postoperative day onward which continued for 2 weeks when the amount started decreasing gradually. There were no signs of peritoneal collection, and the ultrasound examination did not show any dilatation of the bile duct and intra-abdominal collection. The hydroxy iminodiacetic acid scan showed free drainage into the duodenum without any obstruction. The child was discharged on oral feeds, and the drain was removed at the end of 3 weeks. The CBC occurs in 80-90% of the cases in hydatid disease of the liver, but only 13-37% are clinically evident.[1] CBC is described as frank, when preoperative imaging studies reveals biliary communication. But this does not happen in case of a small communication, where the cyst debris would not traverse the cysto-biliary path. The communication will be shown later in the postoperative period in the form of biliary peritonitis or abscess formation in the residual cavity or persistent bile leakage in the drain and is termed as occult CBC. The CBC remains occult as the reverse bilio-cystic flow is not permitted due to high cysto-biliary pressure gradient (intra-cystic pressure is 30-80 cm H2O and intra-biliary pressure is 15-20 cm H2O).[2] Even after removal of the cyst, the pressure dynamics do not change immediately, and the bile may not show up in the cyst cavity. The preoperative predictors of occult CBC include SAP >250 U/L, total bilirubin >17.1 μmol/L, direct bilirubin >6.8 μmol/L, gamma-glutamyl transferase >34.5 U/L, eosinophils >0.09 and the cyst size >8.5 cm.[1] Methods described for intra-operative identification of occult CBC are examination of the cavity using a telescope, injection of air/methylene blue via cystic duct after filling the cavity with saline, package of the cavity with white gauze and looking for the bile stain.[3] Most of the time, the occult CBC will present with biliary peritonitis, whenever primary closure of hydatid cyst cavity without any drainage is practiced. It may necessitate re-exploration and peritoneal lavage. Various studies recommend additional procedures such as intra-operative cystic duct drainage or postoperative endoscopic sphincterotomy in the presence of predictors of occult CBC.[4] However, a keen intra-operative cavity search and closure of the CBC or cyst cavity drainage with a tube drain is sufficient. Most of the cases respond to expectant management like in our patient. Additional endoscopic procedures such as sphincterotomy or stenting of the bile duct are rarely needed and can be reserved for unresponsive cases.

Figure 1

Computed tomography scan showing a large hydatid cyst occupying the right and left lobe of liver