Intrabiliary Obstruction Due to Ruptured Hepatic Hydatid Cyst: Evaluation With Computed Tomography and Magnetic Resonance Imaging

Abstract

Biliary obstruction due to impaction of hydatid material into the biliary tree frequently occurs when complex intrabiliary rupture of hepatic hydatid cyst develops. In our experience, the incidence of intrabiliary rupture causing biliary obstruction totals to 1.1%.The effectiveness of ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI) for the preoperative diagnosis of cyst rupture into the biliary tree has been demonstrated only in case reports or in a series with a few number of cases. In this study we report nine additional cases with CT and MRI findings, together with magnetic resonance (MR) cholangiography which established the preoperative diagnosis. METHODSOver a period of 5 years we studied nine cases with proven intrabiliary rupture of the hepatic hydatid cyst and jaundice using CT, MRI and MR cholangiography. In all cases the diagnosis of the rupture was made by CT, MRI and MR cholangiography and the confirmation of the diagnosis was made at surgery in four cases and with endoscopic retrograde cholangiopancreatography (ERCP) in five cases. The age of the patients at the time of diagnosis ranged between 43 and 74 years. There were seven males and two female patients.Each abdominal CT study was performed with 100 mL of contrast material (Imagopaque, Nycomed) administered Digestive Endoscopy (2001) 13, 7-12 Background: One of the most common and very serious complications of a hepatic echinococcal cyst is the intrabiliary rupture of the cyst and, in some cases, the obstruction of the biliary system. The effectiveness of computed tomography (CT) and magnetic resonance imaging (MRI) was evaluated for the preoperative diagnosis of hydatid cyst into the biliary tree. Methods: The techniques of CT, MRI and magnetic resonance (MR) cholangiography were used to examine nine cases of intrabiliary rupture of the hepatic hydatid cyst. The confirmation of the diagnosis was made at surgery in four cases and with endoscopic retrograde cholangiopancreatography in five cases. Results: By using CT and MRI, the intrabiliary rupture of an echinococcal cyst was diagnosed readily and accurately in all cases. In eight cases, we found a dilated intrahepatic biliary vessel near the ruptured echinococcal cyst, without any evidence of communication between the cyst and the biliary system. Also in six cases there was an abnormal configuration of the terminal part of the biliary radicle. Conclusion: This study suggests that a dilated biliary radicle with conical configuration of its end-part and in close proximity with hydatid cyst is strong evidence of previous or active rupture of hydatid cyst into the biliary system. A combined study of CT or MRI and MR cholangiography is mandatory for proper preoperative evaluation of the intrabiliary rupture of hepatic hydatid cyst.

Endoscopic Management of a Relapsing Hepatic Hydatid Cyst with Intrabiliary Rupture: A Case Report and Review of the Literature

“…The mechanism of intrabiliary rupture seems to be that of entrapment of small bile duct radicles in the pericyst, which due to increased intracystic pressure undergo atrophy resulting in rupture (5,11). Following cyst enlargement, communication with larger ducts is established (12). Most liver hydatid cysts that remain symptom free for long periods of time are mistakenly considered to be at low risk for rupture (13).…”

“…On the contrary, frank rupture, causing intermittent or complete obstruction, can usually be preoperatively diagnosed. Although external biliary fistulas often close spontaneously, they can persist in (3,(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27) 5% of patients, 11% of whom will develop ascending cholangitis (37). Replacement of daily electrolyte and fluid losses has proven to be sufficient in low-output fistulas (less than 300 mL daily output) (35).…”