Gastrointest Radiol 17:41-45 (1992)
Gastrointestinal
Radiology ~) Springer-Verlag New York Inc. 1992
Intrabiliary Rupture of Hepatic Hydatid Cyst: Sonographic and Cholangiographic Appearances S h o w k a t Ali Zargar, M o h a d m m a d Sultan Khuroo, Bashir A h m a d Khan, M o h a m m a d Y o u s u f Dar, M o h a m m a d Sultan Alai, and Parvaiz Koul Department of Gastroenterology, Institute of Medical Sciences, Srinagar (Kashmir), India
A b s t r a c t . Sonographic and cholangiographic appear-
ances of confirmed intrabiliary rupture of a hepatic hydatid cyst were studied in 15 cases. Sonographic findings included liver cyst in all cases; nonshadowing echogenic structures in the dilated biliary tree representing hydatid material, such as fragmented m e m b r a n e s , sand, matrix, and daughter vesicles, in eight cases; and loss of continuity of the cyst wall adjacent to the bile duct representing the site of communication in seven cases. Cholangiographic findings were as follows: filling defects of varying size and shapes in the dilated biliary tree in 13 cases, and changing shape and position of these filling defects in three of them; and leakage of contrast medium into the cyst cavity in 12 cases. Intrabiliary rupture of hepatic hydatid cyst was suggested by sonogr a p h y in 10 cases (66.7%) and at cholangiography in 13 cases (86.6%). We conclude that a joint application of sonography and endoscopic cholangiography is m a n d a t o r y for p r o p e r p r e o p e r a t i v e evaluation of this disorder. K e y w o r d s : H e p a t i c hydatid cyst - -
Ultrasound --
Cholangiography.
Echinococcosis continues to be a major health problem in sheep-raising countries where humans are in close contact with dogs. Hydatid cyst of the liver, the m o s t c o m m o n site, is usually silent and discovered incidentally, but produces s y m p t o m s when the cyst b e c o m e s infected, c o m p r e s s e s or ruptures into the adjacent structures, or grows to an enormous Address offprint requests to: Mohammad Sultan Khuroo, M.D.,
Department of Gastroenterology, Institute of Medical Sciences, PO Box 27, Srinagar (Kashmir), India 190 011
size [1]. Rupture of the cyst into the biliary tree is a serious complication occurring in 5 - 1 5 % of patients with hepatic involvement, and produces a clinical picture of biliary obstruction [2-4]. In the past, the diagnosis has generally b e e n made at laparotomy [3, 4]. Although the value of sonography in the diagnosis of hepatic hydatid cyst is well recognized [5, 6], present knowledge about its utility to predict intrabiliary rupture of a hepatic hydatid cyst is rather scanty and based on a small n u m b e r of patient populations [7-10]. Likewise, the cholangiographic appearance of biliary hydatidosis is limited to a few reports on a few cases only [8, 10-13]. The present report describes sonographic and cholangiographic a p p e a r a n c e s in 15 p r o v e n cases of intrabiliary rupture of hepatic hydatid cyst.
Materials and Methods
From September 1985 through April 1990, 88 proven cases of hepatic hydatidosis due to Echinococcus granulosus were evaluated by us. Fifteen (17%) of these cases had proven rupture of liver hydatid cyst into the biliary tract. The diagnosis was based on the recovery of hydatid material, such as daughter cysts, fragmented membranes, and sand, and the presence of communication between the cyst and the biliary tree at surgery in 14 cases, and at endoscopic retrograde cholangiopancreatography (ERCP) in one. The latter case underwent endoscopic sphincterotomy followed by placement of endoscopic nasobiliary drain, and also percutaneous transhepatic aspiration of the cyst, which produced clear fluid-containing scoleces and hooklets. There was one boy, six men, and eight women (age range 9-52 years; mode 36.5 years). The duration of symptoms ranged from 5 to 90 days (mean 36 +- 12 days). Right upper quadrant pain and jaundice were presenting complaints. Ten cases had pyogenic cholangitis (defined as right upper quadrant pain, high fever with rigors and jaundice) and five had progressive cholestasis. Eight cases had intermittent symptoms. Eight cases had an elevated leukocyte count (14,200-24,000/mm3), all had raised serum biliru-
42
S.A. Zargar et al.: Intrabiliary Rupture of Hepatic Hydatid Cyst
bin (range 3-12 mg/dl; mean 6.6 -+ 2.1 mg/dl) and all had raised serum alkaline phosphatase levels (range 620-2105 IU/L; mean 1225 IU/L). Blood cultures grew E. coil in six cases and K . a e r o g e n o s a in two. On the basis of clinical and routine laboratory data, the diagnoses were as follows: choledocholithiasis in 8; malignancy in 3; and intrabiliary rupture of a hepatic hydatid cyst in 4. Other laboratory tests included positive Casoni's skin test in eight of 12 cases (66.6%) and significant rise in titers of echinococcal indirect hemagglutination antibody in seven of nine cases (77.7%). Sonography of the abdomen was performed with a real-time gray-scale B scanner using probes of 3.5 and 5.0 MHz (Aloka SSD 250). An ERCP was obtained using Olympus JF b3 or JF IT10 duodenoscopes, using 10-15 mg diazepam intravenously as premedication.
(mean 1.4 _+ 0.4 cm) (13 cases); (b) the presence of filling defects of varying sizes and shapes in the common bile duct (13 cases) (Figs. lb, 3b, 4b, and 5); (c) cut-off in the left hepatic duct and the right hepatic duct caused by hydatid material (one case each) (Fig. lb); (d) filling of a cyst cavity with contrast medium from a biliary branch (12 cases) (Figs. 3b and 4B); and (e) displacement of the hepatic ducts (two cases) and common bile duct (one case). Filling defects were single in four cases and multiple in eight and ranged in size from 0.4-2.4 cm (mean 1. l + 0.4 cm). They were outlined as ill-defined or well-defined, oblong, rounded, irregular, or leaf-like defects in the contrast medium. They were seen to change their shape and position in three cases on serial cholangiograms (Fig. 6). Filling defects were not seen in cholangiograms in two cases and both of these cases at surgery contained small pieces of fragmented hydatid membranes in the bile duct. The communication between the biliary tree and cyst cavity was not demonstrated in four cases, but one of these cases at repeat ERCP performed 5 days after the initial procedure showed frank filling of the cyst cavity. Pancreatograms were obtained in 12 cases and none revealed any abnormality. Sonography suggested the diagnosis of intrabiliary rupture of a hepatic hydatid cyst in 10 cases (66.7%) on the following criteria: (a) the presence of hepatic hydatid cyst and (b) the dilated biliary tract or evidence of communication between the cyst and the biliary tract or both. Such a diagnosis was made at ERCP in 13 cases (86.6%) when the dilated biliary tract containing filling defects was seen to have communication with the cyst cavity. A combination of sonography and ERCP suggested the diagnosis in all cases.
Results
Sonography detected cysts in all cases. Cysts were in the right hepatic lobe in eight cases, in the left hepatic lobe in five, and two cysts each in two cases. The size of cysts varied from 5.8-12.5 cm (mean 9.2 -+ 2.3 cm). Sonographic appearances were as follows--(a) cyst appearances: simple fluid-filled cysts containing hydatid sand and undulating or fragmented membranes (five cases) (Fig. la), cysts containing multiple daughter cysts (four patients), with fragmented membranes in three of them, cyst filled mostly with echogenic matrix and a few daughter cysts with a calcified wall (one case); (b) dilatation of extrahepatic bile duct (10 cases); (c) dilatation of hepatic ducts (10 cases); (d) presence of irregular, linear, echogenic structures without acoustic shadowing in the bile duct (eight cases) (Fig. 2); (e) loss of continuity in the cyst wall adjacent to a dilated hepatic duct (seven cases) (Figs. 3a and 4a); and (f) distention of the gallbladder with edema of its wall (10 cases). The common bile duct was normal in diameter in one case and was not examined in four cases due to large cysts obscuring its view. The diameter of the bile duct varied from 0.7-1.5 cm (mean 1.1 -+ 0.2 cm). Loss of continuity in the cyst wall adjacent to a dilated hepatic duct represented sonographic evidence of the site of communication of the cyst with the biliary tract. Intracystic hydatid material was seen crossing the site of communication with the dilated biliary branch in four cases (Fig. 3a). Fragmented membranes were seen as floating linear echogenic structures within the cyst. By ERCP, the papilla of Vater showed edema and erythema in all cases and was patulous in 10 cases. Daughter cysts and fragmented membranes were seen extruding from the papilla in three cases. Cholangiograms were obtained in all cases. Cholangiographic findings were as follows: (a) dilatation of the common bile duct ranging from 0.8-2.3 cm
Discussion
Echinococcosis in humans is most frequently found in the liver, with about a 60% infestation rate [1]. During evolution up to 90% of liver cysts eventually leak into biliary radicles incorporated in the pericyst [4]. However, rupture into the larger bile duct occurs in 5-15% of cases [2-4]. The former rupture is usually silent but the latter complication is serious producing biliary obstruction simulating choledocholithiasis or malignant cholestasis. Therefore, preoperative diagnosis of intrabiliary rupture of the hepatic hydatid cyst is important. Sonography, in agreement with the experience of others [5-6], is quite accurate for identification of hepatic hydatid cysts. We found cysts in all stages of evolution. The amount of echogenic matrix in the cyst is proportional to the age of the cyst [6]. We
S.A. Zargar et al.: Intrabiliary Rupture of Hepatic Hydatid Cyst
43
Fig. 2. Sonogram s h o w s dilated c o m m o n bile duct {arrowhead) filled with multiple linear echogenic structures without acoustic shadows.
Fig. 3. A 36-year-old w o m a n with cholangitis. A Sonogram shows ruptured cyst and dilated hepatic ducts (small arrowhead). There is loss of continuity of the cyst wall adjacent to the dilated hepatic ducts (large arrowhead). B E R C P performed 24 h later shows a dilated main bile duct with leaf-like filling defect possibly due to ruptured m e m b r a n e s or ruptured daughter vesicles (arrowl, and a round filling defect due to an intact daughter vesicle at the lower end of the c o m m o n bile duct {curved arrow). A cyst cavity filled with contrast m e d i u m through the right hepatic duct and a nasobiliary drainage catheter in situ (arrowhead) are seen. Fig. 4. A 41-year-old m a n with with cholangitis and septicemia. A A composite set of two s o n o g r a m s shows a ruptured cyst (el, distended gallbladder (GB), dilated left hepatic duct (LHDL and the c o m m o n bile duct ICBD) without demonstrable filling defects. B E R C P s h o w s multiple intact daughter cysts producing filling defects in the c o m m o n bile duct. Contrast-filled cavity communicating with the main bile duct is seen. Fig. 1. A 45-year-old m a n with cholestasis, a Transverse sonogram s h o w s a large hydatid cyst with long linear, folded echogenic structures representing detached m e m b r a n e s . B An E R C P s h o w s a filling defect in the c o m m o n hepatic duct (arrowheads) with a cut off in the left hepatic duct caused possibly by hydatid material plugging the site of communication.
Fig. 5. Cholangiogram obtained at E R C P s h o w s a left-like filling defect in the c o m m o n bile duct. Fig. 6. A E R C P s h o w s an ova/filling defect in the middle part of the c o m m o n bile duct (arrowheads). B Cholangiogram 5 min later shows a linear filling defect tarrowheadsl caused by daughter cyst m e m b r a n e s . Hepatic ducts have n o t filled, possibly due to blockage to the site of c o m m u n i c a t i o n by hydatid material.
44
S.A. Zargar et al.: Intrabiliary Rupture of Hepatic Hydatid Cyst
unlike others [5], but in agreement with some [6-8], feel that overmature cysts are not associated with a higher incidence of perforation. Fragmented membranes within a cyst are represented sonographically by floating linear echogenic structures and this is equivalent to the radiographic water lily sign. However, this type of sonographic finding occurs even with contained or communicating rupture of a cyst [5]. Sonographic visualization of ruptured hydatid cyst material into the biliary tree, and the site of communication between a cyst and the biliary tract, offer direct evidences of intrabiliary rupture of a hepatic hydatid cyst. Hydatid cyst contents in the biliary tree appear as echogenic structures of varying sizes and shapes without acoustic shadowing simulating biliary sludge, nonshadowing calculi, or round worms [14]. We feel these represent the hydatid matrix, sand, and detached membranes rather than daughter vesicles as believed by others [8, 10]. Daughter and granddaughter cysts in most cases are fluid-filled structures with acoustic impedance similar to that of bile, and their cyst walls are too thin to be seen sonographically (Fig. 4). Even daughter vesicles of an overmature mother cyst are infrequently echogenic [15]. The site of perforation of a hepatic hydatid cyst into the biliary tract is represented by loss of continuity in the cyst wall connected to the dilated biliary branch. This was seen in 46.7% of our cases and was diagnostic of perforation especially when hydatid contents were seen across the site of perforation into the dilated biliary branch. Dilatation of a bile duct was a consistent sonographic finding. The packing of the bile duct with intracystic hydatid material is the likely mechanism. The changes in the gallbladder were possibly related to impacted hydatid material in the common bile duct. Rarely, a hepatic hydatid cyst ruptures into the gallbladder or intracystic hydatid material enters into the gallbladder. ERCP was found quite valuable in the diagnosis of intrabiliary rupture of a hepatic hydatid cyst. Percutaneous transhepatic cholangiography in isolated case reports has been used to demonstrate the rupture of a cyst into the biliary tree [10, 11]. However, it is best avoided in suspected hydatid disease because of the risk of peritoneal seeding or anaphylaxis, although diagnostic and therapeutic aspiration of a hepatic hydatid cyst has been attempted by us (unpublished observations) and others recently [16]. The detection of intrabiliary filling defects and communication of the biliary tract with a liver cyst are specific for intrabiliary rupture of a hepatic hydatid cyst. While compression, obstruction, or displacement of the biliary tree suggest a liver cyst, dilatation of the biliary tree is indirect evidence of its rupture. Intrabiliary filling defects, solitary or multiple,
representing fragmented membranes and/or daughter cysts, may simulate stones in the biliary tree. Fragmented membranes produce ill-defined irregular, leaf-like filling defects which can be easily differentiated from stones. Moreover, changing shapes of filling defects on serial cholangiograms suggest the presence of fragmented membranes and/or ruptured daughter cysts, which further help in differentiating them from calculi. This finding has rarely been described previously [12, 13]. The ERCP failed to demonstrate communication between a liver cyst and the biliary tract in 20% of cases, possibly because the perforation site at the time of ERCP procedure was plugged by a daughter cyst or fragmented membranes. Although sonography is a simple, safe, and highly accurate tool for the diagnosis of noncomplicated hepatic hydatid cysts, the present data shows that it can also predict with fair degree of accuracy the intrabiliary rupture of a hydatid liver cyst. ERCP is probably the method of choice for confirming the perforation of an hepatic hydatid cyst into the biliary tract for the following reasons: (a) it has a higher sensitivity and specificity compared to sonography; (b) it permits delination of the exact site of perforation; (c) it assesses the placement of intracystic hydatid material inside the biliary tract--an essential prerequisite for planning surgery; (d) it is of particular value when sonography is technically inadequate or not diagnostic; and (e) it can be exploited for nonsurgical treatment of this disorder [17] as was carried out successfully in one case in the present series. We conclude that sonography and ERCP are complementary to each other in the preoperative evaluation of ruptured hepatic hydatid cyst into the biliary tract. Acknowledgment. The authors thank Mr. Mehraj-ud-Din, P.A., for manuscript preparation.
References 1. Lewis JW, Koss N, Kertein MD. A review of echinococcal disease. Ann Surg 1975:181:390-396 2. Macris GJ, Galanis NN. Rupture of echinococcus cyst of the liver into the biliary duct. Ann Surg 1966;32:36-44 3. AI Hashimi HM. Intrabiliary rupture of hydatid cyst of the liver. Br J Surg 1971 ;58:228-232 4. Harris JD. Rupture of hydatid cyst into the biliary tract. Br J Surg 1965;52:210-212 5. Marti-Bonmati L, Serrano FM. Complications of hepatic hydatid cysts: ultrasound, computed tomography and magnetic resonance diagnosis. Gastrointest Radiol 1990;15:119-125 6. Lewall DB, McCorkell SJ. Hepatic echinococcal cysts: sonographic appearance and classification. Radiology 1985; 155:773-775 7. Barki Y, Charuzi I. Intrabiliary rupture of hydatid cyst of the liver: sonographic diagnosis. J Clin Ultrasound 1985; 13:40-41
S.A. Zargar et al.: Intrabiliary Rupture of Hepatic Hydatid Cyst
45
8. McCorkell SJ. Echinococcal cysts in the common bile duct: an uncommon cause of obstruction. Gastrointest Radiol 1985;10:390-393 9. Camunez F, Simo G, Robledo R, et al. Ultrasound diagnosis of ruptured hydatid cyst of the liver with biliary obstruction. Gastrointest Radiol 1986;11:330-333 10. Tuttle RJ. Cause of recurring obstructive jaundice revealed by percutaneous cholangiography--hydatid cyst. N Engl J Med 1970 ;283:805-806 11. Farrelly C, Lawrie BW. Diagnosis of intrabiliary rupture of hydatid cyst of the liver by fine-needle percutaneous transhepatic cholangiography. Br J Radiol 1982;55:372-373 12. Cotton M, Amusc M, Cotton PB. Endoscopic retrograde cholangiopancreaticography in hepatic hydatid disease. Br J Surg 1978;65:107-108 13. Vicente VFM, Garcia M, Marco SMA. Endoscopic retro-
grade cholangiography (ERCP) and complicated hepatic hydatid cyst in the biliary tract. Endoscopy 1984;16:124-126 Khuroo MS, Zargar SA, Mahajan R, Bhat RL, Javid G. Sonographic appearances in biliary ascariasis. Gastroenterology 1987;93:267-272 Garcia FJ, Marti-Bonmati L, Menor F, Rodriguez B, Ballesta A. Echogenic forms of hydatid cysts: sonographic diagnosis. JCU 1988;16:305-312 Mueller PR, Dawson SL, Ferruci JT Jr, Nardi GL. Hepatic echinococcal cyst: successful percutaneous drainage. A JR 1985; 155:627-628 A1-Karawi MA, Mohamed ARE, Yasawy I, Haleem A. Nonsurgical endoscopic transpapillary treatment of ruptured echinococcus liver cyst obstructing the biliary tree. Endoscopy 1987:19:81-83
14. 15. 16.
17.
Received: March 12, 1991; accepted : April 26, 1991
Gastrointestinal
Radiology ~) Springer-Verlag New York Inc. 1992
Intrabiliary Rupture of Hepatic Hydatid Cyst: Sonographic and Cholangiographic Appearances S h o w k a t Ali Zargar, M o h a d m m a d Sultan Khuroo, Bashir A h m a d Khan, M o h a m m a d Y o u s u f Dar, M o h a m m a d Sultan Alai, and Parvaiz Koul Department of Gastroenterology, Institute of Medical Sciences, Srinagar (Kashmir), India
A b s t r a c t . Sonographic and cholangiographic appear-
ances of confirmed intrabiliary rupture of a hepatic hydatid cyst were studied in 15 cases. Sonographic findings included liver cyst in all cases; nonshadowing echogenic structures in the dilated biliary tree representing hydatid material, such as fragmented m e m b r a n e s , sand, matrix, and daughter vesicles, in eight cases; and loss of continuity of the cyst wall adjacent to the bile duct representing the site of communication in seven cases. Cholangiographic findings were as follows: filling defects of varying size and shapes in the dilated biliary tree in 13 cases, and changing shape and position of these filling defects in three of them; and leakage of contrast medium into the cyst cavity in 12 cases. Intrabiliary rupture of hepatic hydatid cyst was suggested by sonogr a p h y in 10 cases (66.7%) and at cholangiography in 13 cases (86.6%). We conclude that a joint application of sonography and endoscopic cholangiography is m a n d a t o r y for p r o p e r p r e o p e r a t i v e evaluation of this disorder. K e y w o r d s : H e p a t i c hydatid cyst - -
Ultrasound --
Cholangiography.
Echinococcosis continues to be a major health problem in sheep-raising countries where humans are in close contact with dogs. Hydatid cyst of the liver, the m o s t c o m m o n site, is usually silent and discovered incidentally, but produces s y m p t o m s when the cyst b e c o m e s infected, c o m p r e s s e s or ruptures into the adjacent structures, or grows to an enormous Address offprint requests to: Mohammad Sultan Khuroo, M.D.,
Department of Gastroenterology, Institute of Medical Sciences, PO Box 27, Srinagar (Kashmir), India 190 011
size [1]. Rupture of the cyst into the biliary tree is a serious complication occurring in 5 - 1 5 % of patients with hepatic involvement, and produces a clinical picture of biliary obstruction [2-4]. In the past, the diagnosis has generally b e e n made at laparotomy [3, 4]. Although the value of sonography in the diagnosis of hepatic hydatid cyst is well recognized [5, 6], present knowledge about its utility to predict intrabiliary rupture of a hepatic hydatid cyst is rather scanty and based on a small n u m b e r of patient populations [7-10]. Likewise, the cholangiographic appearance of biliary hydatidosis is limited to a few reports on a few cases only [8, 10-13]. The present report describes sonographic and cholangiographic a p p e a r a n c e s in 15 p r o v e n cases of intrabiliary rupture of hepatic hydatid cyst.
Materials and Methods
From September 1985 through April 1990, 88 proven cases of hepatic hydatidosis due to Echinococcus granulosus were evaluated by us. Fifteen (17%) of these cases had proven rupture of liver hydatid cyst into the biliary tract. The diagnosis was based on the recovery of hydatid material, such as daughter cysts, fragmented membranes, and sand, and the presence of communication between the cyst and the biliary tree at surgery in 14 cases, and at endoscopic retrograde cholangiopancreatography (ERCP) in one. The latter case underwent endoscopic sphincterotomy followed by placement of endoscopic nasobiliary drain, and also percutaneous transhepatic aspiration of the cyst, which produced clear fluid-containing scoleces and hooklets. There was one boy, six men, and eight women (age range 9-52 years; mode 36.5 years). The duration of symptoms ranged from 5 to 90 days (mean 36 +- 12 days). Right upper quadrant pain and jaundice were presenting complaints. Ten cases had pyogenic cholangitis (defined as right upper quadrant pain, high fever with rigors and jaundice) and five had progressive cholestasis. Eight cases had intermittent symptoms. Eight cases had an elevated leukocyte count (14,200-24,000/mm3), all had raised serum biliru-
42
S.A. Zargar et al.: Intrabiliary Rupture of Hepatic Hydatid Cyst
bin (range 3-12 mg/dl; mean 6.6 -+ 2.1 mg/dl) and all had raised serum alkaline phosphatase levels (range 620-2105 IU/L; mean 1225 IU/L). Blood cultures grew E. coil in six cases and K . a e r o g e n o s a in two. On the basis of clinical and routine laboratory data, the diagnoses were as follows: choledocholithiasis in 8; malignancy in 3; and intrabiliary rupture of a hepatic hydatid cyst in 4. Other laboratory tests included positive Casoni's skin test in eight of 12 cases (66.6%) and significant rise in titers of echinococcal indirect hemagglutination antibody in seven of nine cases (77.7%). Sonography of the abdomen was performed with a real-time gray-scale B scanner using probes of 3.5 and 5.0 MHz (Aloka SSD 250). An ERCP was obtained using Olympus JF b3 or JF IT10 duodenoscopes, using 10-15 mg diazepam intravenously as premedication.
(mean 1.4 _+ 0.4 cm) (13 cases); (b) the presence of filling defects of varying sizes and shapes in the common bile duct (13 cases) (Figs. lb, 3b, 4b, and 5); (c) cut-off in the left hepatic duct and the right hepatic duct caused by hydatid material (one case each) (Fig. lb); (d) filling of a cyst cavity with contrast medium from a biliary branch (12 cases) (Figs. 3b and 4B); and (e) displacement of the hepatic ducts (two cases) and common bile duct (one case). Filling defects were single in four cases and multiple in eight and ranged in size from 0.4-2.4 cm (mean 1. l + 0.4 cm). They were outlined as ill-defined or well-defined, oblong, rounded, irregular, or leaf-like defects in the contrast medium. They were seen to change their shape and position in three cases on serial cholangiograms (Fig. 6). Filling defects were not seen in cholangiograms in two cases and both of these cases at surgery contained small pieces of fragmented hydatid membranes in the bile duct. The communication between the biliary tree and cyst cavity was not demonstrated in four cases, but one of these cases at repeat ERCP performed 5 days after the initial procedure showed frank filling of the cyst cavity. Pancreatograms were obtained in 12 cases and none revealed any abnormality. Sonography suggested the diagnosis of intrabiliary rupture of a hepatic hydatid cyst in 10 cases (66.7%) on the following criteria: (a) the presence of hepatic hydatid cyst and (b) the dilated biliary tract or evidence of communication between the cyst and the biliary tract or both. Such a diagnosis was made at ERCP in 13 cases (86.6%) when the dilated biliary tract containing filling defects was seen to have communication with the cyst cavity. A combination of sonography and ERCP suggested the diagnosis in all cases.
Results
Sonography detected cysts in all cases. Cysts were in the right hepatic lobe in eight cases, in the left hepatic lobe in five, and two cysts each in two cases. The size of cysts varied from 5.8-12.5 cm (mean 9.2 -+ 2.3 cm). Sonographic appearances were as follows--(a) cyst appearances: simple fluid-filled cysts containing hydatid sand and undulating or fragmented membranes (five cases) (Fig. la), cysts containing multiple daughter cysts (four patients), with fragmented membranes in three of them, cyst filled mostly with echogenic matrix and a few daughter cysts with a calcified wall (one case); (b) dilatation of extrahepatic bile duct (10 cases); (c) dilatation of hepatic ducts (10 cases); (d) presence of irregular, linear, echogenic structures without acoustic shadowing in the bile duct (eight cases) (Fig. 2); (e) loss of continuity in the cyst wall adjacent to a dilated hepatic duct (seven cases) (Figs. 3a and 4a); and (f) distention of the gallbladder with edema of its wall (10 cases). The common bile duct was normal in diameter in one case and was not examined in four cases due to large cysts obscuring its view. The diameter of the bile duct varied from 0.7-1.5 cm (mean 1.1 -+ 0.2 cm). Loss of continuity in the cyst wall adjacent to a dilated hepatic duct represented sonographic evidence of the site of communication of the cyst with the biliary tract. Intracystic hydatid material was seen crossing the site of communication with the dilated biliary branch in four cases (Fig. 3a). Fragmented membranes were seen as floating linear echogenic structures within the cyst. By ERCP, the papilla of Vater showed edema and erythema in all cases and was patulous in 10 cases. Daughter cysts and fragmented membranes were seen extruding from the papilla in three cases. Cholangiograms were obtained in all cases. Cholangiographic findings were as follows: (a) dilatation of the common bile duct ranging from 0.8-2.3 cm
Discussion
Echinococcosis in humans is most frequently found in the liver, with about a 60% infestation rate [1]. During evolution up to 90% of liver cysts eventually leak into biliary radicles incorporated in the pericyst [4]. However, rupture into the larger bile duct occurs in 5-15% of cases [2-4]. The former rupture is usually silent but the latter complication is serious producing biliary obstruction simulating choledocholithiasis or malignant cholestasis. Therefore, preoperative diagnosis of intrabiliary rupture of the hepatic hydatid cyst is important. Sonography, in agreement with the experience of others [5-6], is quite accurate for identification of hepatic hydatid cysts. We found cysts in all stages of evolution. The amount of echogenic matrix in the cyst is proportional to the age of the cyst [6]. We
S.A. Zargar et al.: Intrabiliary Rupture of Hepatic Hydatid Cyst
43
Fig. 2. Sonogram s h o w s dilated c o m m o n bile duct {arrowhead) filled with multiple linear echogenic structures without acoustic shadows.
Fig. 3. A 36-year-old w o m a n with cholangitis. A Sonogram shows ruptured cyst and dilated hepatic ducts (small arrowhead). There is loss of continuity of the cyst wall adjacent to the dilated hepatic ducts (large arrowhead). B E R C P performed 24 h later shows a dilated main bile duct with leaf-like filling defect possibly due to ruptured m e m b r a n e s or ruptured daughter vesicles (arrowl, and a round filling defect due to an intact daughter vesicle at the lower end of the c o m m o n bile duct {curved arrow). A cyst cavity filled with contrast m e d i u m through the right hepatic duct and a nasobiliary drainage catheter in situ (arrowhead) are seen. Fig. 4. A 41-year-old m a n with with cholangitis and septicemia. A A composite set of two s o n o g r a m s shows a ruptured cyst (el, distended gallbladder (GB), dilated left hepatic duct (LHDL and the c o m m o n bile duct ICBD) without demonstrable filling defects. B E R C P s h o w s multiple intact daughter cysts producing filling defects in the c o m m o n bile duct. Contrast-filled cavity communicating with the main bile duct is seen. Fig. 1. A 45-year-old m a n with cholestasis, a Transverse sonogram s h o w s a large hydatid cyst with long linear, folded echogenic structures representing detached m e m b r a n e s . B An E R C P s h o w s a filling defect in the c o m m o n hepatic duct (arrowheads) with a cut off in the left hepatic duct caused possibly by hydatid material plugging the site of communication.
Fig. 5. Cholangiogram obtained at E R C P s h o w s a left-like filling defect in the c o m m o n bile duct. Fig. 6. A E R C P s h o w s an ova/filling defect in the middle part of the c o m m o n bile duct (arrowheads). B Cholangiogram 5 min later shows a linear filling defect tarrowheadsl caused by daughter cyst m e m b r a n e s . Hepatic ducts have n o t filled, possibly due to blockage to the site of c o m m u n i c a t i o n by hydatid material.
44
S.A. Zargar et al.: Intrabiliary Rupture of Hepatic Hydatid Cyst
unlike others [5], but in agreement with some [6-8], feel that overmature cysts are not associated with a higher incidence of perforation. Fragmented membranes within a cyst are represented sonographically by floating linear echogenic structures and this is equivalent to the radiographic water lily sign. However, this type of sonographic finding occurs even with contained or communicating rupture of a cyst [5]. Sonographic visualization of ruptured hydatid cyst material into the biliary tree, and the site of communication between a cyst and the biliary tract, offer direct evidences of intrabiliary rupture of a hepatic hydatid cyst. Hydatid cyst contents in the biliary tree appear as echogenic structures of varying sizes and shapes without acoustic shadowing simulating biliary sludge, nonshadowing calculi, or round worms [14]. We feel these represent the hydatid matrix, sand, and detached membranes rather than daughter vesicles as believed by others [8, 10]. Daughter and granddaughter cysts in most cases are fluid-filled structures with acoustic impedance similar to that of bile, and their cyst walls are too thin to be seen sonographically (Fig. 4). Even daughter vesicles of an overmature mother cyst are infrequently echogenic [15]. The site of perforation of a hepatic hydatid cyst into the biliary tract is represented by loss of continuity in the cyst wall connected to the dilated biliary branch. This was seen in 46.7% of our cases and was diagnostic of perforation especially when hydatid contents were seen across the site of perforation into the dilated biliary branch. Dilatation of a bile duct was a consistent sonographic finding. The packing of the bile duct with intracystic hydatid material is the likely mechanism. The changes in the gallbladder were possibly related to impacted hydatid material in the common bile duct. Rarely, a hepatic hydatid cyst ruptures into the gallbladder or intracystic hydatid material enters into the gallbladder. ERCP was found quite valuable in the diagnosis of intrabiliary rupture of a hepatic hydatid cyst. Percutaneous transhepatic cholangiography in isolated case reports has been used to demonstrate the rupture of a cyst into the biliary tree [10, 11]. However, it is best avoided in suspected hydatid disease because of the risk of peritoneal seeding or anaphylaxis, although diagnostic and therapeutic aspiration of a hepatic hydatid cyst has been attempted by us (unpublished observations) and others recently [16]. The detection of intrabiliary filling defects and communication of the biliary tract with a liver cyst are specific for intrabiliary rupture of a hepatic hydatid cyst. While compression, obstruction, or displacement of the biliary tree suggest a liver cyst, dilatation of the biliary tree is indirect evidence of its rupture. Intrabiliary filling defects, solitary or multiple,
representing fragmented membranes and/or daughter cysts, may simulate stones in the biliary tree. Fragmented membranes produce ill-defined irregular, leaf-like filling defects which can be easily differentiated from stones. Moreover, changing shapes of filling defects on serial cholangiograms suggest the presence of fragmented membranes and/or ruptured daughter cysts, which further help in differentiating them from calculi. This finding has rarely been described previously [12, 13]. The ERCP failed to demonstrate communication between a liver cyst and the biliary tract in 20% of cases, possibly because the perforation site at the time of ERCP procedure was plugged by a daughter cyst or fragmented membranes. Although sonography is a simple, safe, and highly accurate tool for the diagnosis of noncomplicated hepatic hydatid cysts, the present data shows that it can also predict with fair degree of accuracy the intrabiliary rupture of a hydatid liver cyst. ERCP is probably the method of choice for confirming the perforation of an hepatic hydatid cyst into the biliary tract for the following reasons: (a) it has a higher sensitivity and specificity compared to sonography; (b) it permits delination of the exact site of perforation; (c) it assesses the placement of intracystic hydatid material inside the biliary tract--an essential prerequisite for planning surgery; (d) it is of particular value when sonography is technically inadequate or not diagnostic; and (e) it can be exploited for nonsurgical treatment of this disorder [17] as was carried out successfully in one case in the present series. We conclude that sonography and ERCP are complementary to each other in the preoperative evaluation of ruptured hepatic hydatid cyst into the biliary tract. Acknowledgment. The authors thank Mr. Mehraj-ud-Din, P.A., for manuscript preparation.
References 1. Lewis JW, Koss N, Kertein MD. A review of echinococcal disease. Ann Surg 1975:181:390-396 2. Macris GJ, Galanis NN. Rupture of echinococcus cyst of the liver into the biliary duct. Ann Surg 1966;32:36-44 3. AI Hashimi HM. Intrabiliary rupture of hydatid cyst of the liver. Br J Surg 1971 ;58:228-232 4. Harris JD. Rupture of hydatid cyst into the biliary tract. Br J Surg 1965;52:210-212 5. Marti-Bonmati L, Serrano FM. Complications of hepatic hydatid cysts: ultrasound, computed tomography and magnetic resonance diagnosis. Gastrointest Radiol 1990;15:119-125 6. Lewall DB, McCorkell SJ. Hepatic echinococcal cysts: sonographic appearance and classification. Radiology 1985; 155:773-775 7. Barki Y, Charuzi I. Intrabiliary rupture of hydatid cyst of the liver: sonographic diagnosis. J Clin Ultrasound 1985; 13:40-41
S.A. Zargar et al.: Intrabiliary Rupture of Hepatic Hydatid Cyst
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8. McCorkell SJ. Echinococcal cysts in the common bile duct: an uncommon cause of obstruction. Gastrointest Radiol 1985;10:390-393 9. Camunez F, Simo G, Robledo R, et al. Ultrasound diagnosis of ruptured hydatid cyst of the liver with biliary obstruction. Gastrointest Radiol 1986;11:330-333 10. Tuttle RJ. Cause of recurring obstructive jaundice revealed by percutaneous cholangiography--hydatid cyst. N Engl J Med 1970 ;283:805-806 11. Farrelly C, Lawrie BW. Diagnosis of intrabiliary rupture of hydatid cyst of the liver by fine-needle percutaneous transhepatic cholangiography. Br J Radiol 1982;55:372-373 12. Cotton M, Amusc M, Cotton PB. Endoscopic retrograde cholangiopancreaticography in hepatic hydatid disease. Br J Surg 1978;65:107-108 13. Vicente VFM, Garcia M, Marco SMA. Endoscopic retro-
grade cholangiography (ERCP) and complicated hepatic hydatid cyst in the biliary tract. Endoscopy 1984;16:124-126 Khuroo MS, Zargar SA, Mahajan R, Bhat RL, Javid G. Sonographic appearances in biliary ascariasis. Gastroenterology 1987;93:267-272 Garcia FJ, Marti-Bonmati L, Menor F, Rodriguez B, Ballesta A. Echogenic forms of hydatid cysts: sonographic diagnosis. JCU 1988;16:305-312 Mueller PR, Dawson SL, Ferruci JT Jr, Nardi GL. Hepatic echinococcal cyst: successful percutaneous drainage. A JR 1985; 155:627-628 A1-Karawi MA, Mohamed ARE, Yasawy I, Haleem A. Nonsurgical endoscopic transpapillary treatment of ruptured echinococcus liver cyst obstructing the biliary tree. Endoscopy 1987:19:81-83
14. 15. 16.
17.
Received: March 12, 1991; accepted : April 26, 1991
