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Intrahepatic arterioportal fistula: gadolinium-enhanced 3D magnetic resonance angiography findings and angiographic embolization with steel coils
Magnetic Resonance Imaging, Vol. 17, No. 3, pp. 475– 478, 1999 © 1999 Elsevier Science Inc. All rights reserved. Printed in the USA. 0730-725X/99 $–see front matter
PII S0730-725X(98)00201-X
● Case Report
INTRAHEPATIC ARTERIOPORTAL FISTULA: GADOLINIUM-ENHANCED 3D MAGNETIC RESONANCE ANGIOGRAPHY FINDINGS AND ANGIOGRAPHIC EMBOLIZATION WITH STEEL COILS NUMAN CEM BALCI, RICHARD C. SEMELKA,
AND
JEET S. SANDHU
Department of Radiology, University of North Carolina, Chapel Hill, NC, USA We describe a case of a 59-year-old patient with intrahepatic arterioportal fistula secondary to blunt trauma sustained by a motor vehicle accident 36 years earlier. The fistula was demonstrated 36 years after the accident in a clinical work-up for diarrhea of 1 month’s duration, using contrast enhanced three-dimensional breath-hold MRA. A communication between the dilated portal vein and dilated hepatic artery was shown at the level of distal branches. After subsequent demonstration by conventional angiography, the fistula was embolized using steel coils. Following the therapeutic intervention, the patient’s diarrhea ceased. © 1999 Elsevier Science Inc. Keywords: Arterioportal fistula; Enhanced 3D FISP; Hepatic artery.
exploratory laparotomy and also a partial hepatic resection and repair. Three weeks prior to his recent admission, a cholecystectomy was performed. The cystic artery, and vein were ligated during this procedure: no collateral vessels were identified in the gallbladder wall at surgery. The patient was admitted to our center because of persistent diarrhea for one months duration. Infectious colitis was excluded by stool cultures and screening for ova and parasites. Arterial phase CT scan was performed, which revealed an irregular liver contour, splenomegaly, portal hypertension and a markedly dilated right portal vein branch. The possibility of an arterioportal fistula (APF) was raised. Thickening of the colonic wall was also observed. The patient was referred for a MRI examination for further investigation with an MR angiogram to exclude an APF. All images were obtained on a 1.5 T MR scanner (Vision, Siemens Medical Systems, Iselin, NJ, USA) with the use of a phased array body coil. Gadolinium enhanced MRA was performed using a 3D gradient echo (FISP) sequence. Parameters for the 3D FISP sequence were: TR 5 5 ms/TE 5 2 ms/FA 5 30°/slab thickness 96 mm/number of partitions 5 48/effective slice thickness 2 mm/matrix 5 96 3 256/FOV 5 319 3 425
INTRODUCTION Arterioportal fistulas (APFs) are rare,1 they may be intrahepatic or extrahepatic in location and present major diagnostic and therapeutic challenges. Angiography has been the method of choice in the detection of APFs.2 Reports have shown that ultrasound, computerized tomography (CT), and magnetic resonance angiography (MRA) can all demonstrate APFs,2– 4 however, clear delineation of arterioportal communication using methods other than angiography may be difficult.3,4 With the implementation of gadolinium-enhanced MR angiography, detailed evaluation of abdominal vessels has been shown. To our knowledge no prior report has described the appearance of an arterioportal fistula by gadoliniumenhanced 3D MRA. We present a case of an APF, that was well demonstrated by MRA and subsequently successfully treated with angiographically directed hepatic arterial placement of an embolization coil. CASE REPORT A 59-year-old patient had a history of a motor vehicle accident 36 years ago, following which he underwent an RECEIVED 7/31/98; ACCEPTED 7/22/98. Address correspondence to Dr. Richard C. Semelka, Department of Radiology, UNC School of Medicine, The Univer-
sity of North Carolina, CB# 7510, Chapel Hill, NC 275997510. 475
476
Magnetic Resonance Imaging ● Volume 17, Number 3, 1999
mm/acquisition time 5 26 s breath-hold. A rapid hand injection of 40 mL gadolinium (Magnevist, Berlex, Wayne, NJ, USA) was administered and scanning with the MRA sequence was initiated 10 s after the start of injection. A second pass of 3D FISP was performed, following a 10-s delay. Transverse fat suppressed spoiled gradient echo sequence was performed following the MRA sequence through the upper abdomen. Postprocessing was accomplished using maximum intensity projection (MIP) algorithm. The site of connection between the dilated hepatic artery and dilated portal vein was well shown on a source 2D image from the first pass of the 3D FISP sequence (Fig. 1). MIP reconstruction revealed the full extent of these dilated vessels (Fig. 1). Clear visualization of patent superior mesenteric vein and artery was shown. The gadolinium enhanced fat suppressed spoiled gradient echo images revealed submucosal edema of the colon with prominent serosal and mucosal enhancement (Fig. 1). Following the demonstration of an APF the patient proceeded to angiography for definitive treatment. Using a transfemoral approach, the catheter was advanced into the hepatic artery and a hepatic arteriogram was obtained (Fig. 2), which demonstrated a markedly enlarged anterior right hepatic artery in communication with a branch of the anterior right portal vein. There was hepatofugal flow in the right portal vein and the main portal vein accompanied by retrograde flow in the splenic vein and the superior mesenteric vein (Fig. 2). The right hepatic artery was successfully embolized proximal to the AV fistula, utilizing a combination of 12 and 10 mm Gianturco coils as well as a single 7 mm in diameter Tracker coil. Gelfoam torpedoes and large particles were also utilized to promote thrombosis at the site of coil deployment (Fig. 2). The patient’s clinical symptoms resolved the next day. DISCUSSION Hepatic APFs can be classified into two groups: congenital and acquired.5 Cavernous hemangioma, arteriovenous aneurysm, hereditary teleangiectasia, and Ehler Danlos syndrome are the main causes of congenital APFs. Acquired APFs most commonly arise secondary to trauma or iatrogenic causes. Liver tumors, metastatic lesions to liver, cirrhosis, rupture of preexisting aneurysm are rarer causes of acquired APFs. Symptoms of patients with APF can vary with the size and location of the arterioportal communication. The initial clinical manifestation is usually gastrointestinal bleeding. Ascites and diarrhea, if bowel wall edema develops, are other clinical symptoms.1,2 Our patient presented with diarrhea, and bowel wall edema was well shown on gadolinium enhanced fat suppressed SGE images. Hemodynami-
Fig. 1. A, 2D source image of the gadolinium enhanced 3D FISP in the arterial phase demonstrates the connection between right hepatic artery and right portal vein (arrow). B, MIP reconstruction of the first pass MRA sequence reveals the full extent of the dilated right hepatic artery (long arrow, B) and portal vein (short arrow, B). C, Gadolinium enhanced fat suppressed axial (SGE) image reveals submucosal edema of the colon (arrow) with prominent serosal, and mucosal enhancement.
Intrahepatic arterioportal fistula: MRI findings ● N. C. BALCI
Fig. 2. A, DSA image of hepatic arteriogram reveals a markedly enlarged right hepatic artery (short arrow, A) and communication between the right hepatic artery and right portal vein (long arrow, A). B, Retrograde flow in superior mesenteric vein (arrow) is also visualized. In C, after the placement of Gianturco coils (long arrow, C), the proximal right hepatic artery was thrombosed (short arrow, C). No flow is observed in the fistula.
ET AL.
477
cally compensated shunts, which are not diagnosed at the onset of the fistula, have a characteristic time course as described by Stone et al.6 Gastrointestinal bleeding due to mucosal congestion may occur during the first 3 weeks to 6 months, a quiescent period then ensues, which typically lasts between 6 months to 5 years, during which patients usually live symptom-free for many years. This lengthy symptom-free period was observed in our patient, who was asymptomatic for 36 years following trauma. Because of the low resistance and high capacity of the portal system, a small arterioportal fistula can be accommodated without significant pressure rise, pressure depends directly on the shunt volume and sinusoidal resistance and indirectly on the capacity of the portal vascular bed.6 Once the portal hypertension persists to a moderate degree, the increased pressure in the splanchnic bed leads to typical symptoms related to portal hypertension.6 The increase of the pressure in the portal system may be aggravated by ligation of the cystic vein. In our patient, symptoms of diarrhea secondary to portal hypertension arose following cholecystectomy. It is likely that there may have been a portosystemic collateral pathway via the cystic veins of the gallbladder, which may have allowed some decompression of the elevated pressures within the portal system. With elevated portal pressures, flow reverse in the cystic vein may have then emptied into other mesenteric veins and/or into systemic abdominal veins.6,7 The elimination of this decompressive pathway by cholecystectomy, may have removed the compensating portosystemic shunting resulting in the development of the patient’s symptoms. AFPs are definitively diagnosed by angiography. Previous reports indicate that CT and doppler ultrasound may also successfully demonstrate arterioportal fistulas.3,4 MR angiography using time of flight or phasecontrast technique have been used for the detection of AFPs, however, lengthy examination times and flow dephasing with turbulent flow are problematic.8 The implementation of gadolinium enhanced 3D MRA, has resulted in reliable reproducible good quality MRA studies of abdominal vessels.8,9 The 3D data sampling enables the evaluation of convoluted vessels and complex small vessel pathologies, which may be observed in the setting of fistulas. In our case, a fistula between a distal branch of the hepatic artery and portal vein was shown clearly using this technique. The arterial phase revealed enhancement of both hepatic artery and right portal vein including the mesenteric vein, which suggested the retrograde filling of the right portal vein. Our case showed that contrast enhanced MRA can demonstrate arterioportal fistulas. Comparative studies between imaging modalities (e.g., CT, doppler ultrasound, and MRA) in larger series have to be performed to define the diagnostic value of MRA, and to establish a diagnostic algorithm for patients with arterioportal fistulas. The demonstration of bowel wall
478
Magnetic Resonance Imaging ● Volume 17, Number 3, 1999
diseases has been reported on MR imaging. Gadolinium enhanced T1-weighted fat suppressed images have been effective at demonstrating the bowel wall and revealing submucosal edema in conditions such as ulcerative colitis.10 This MR technique was also effective in our patient, revealing submucosal edema, which we conjectured reflected portal hypertension. In the past, the treatment of arterio-portal fistulas required surgical intervention.2 The type of operation depends on the location and etiology of the fistula. Extrahepatic arterio-portal fistulas can usually be treated by ligation and bypass grafting or primary anastomosis, if technically feasible. Intrahepatic arterio-portal fistulas due to iatrogenic injuries or trauma usually require resection of the involved segment or lobe of the liver. Surgical therapy is associated with significant morbidity and mortality.3,11 With recent advances in interventional techniques, percutaneous embolotherapy has become a very effective method of treating AFPs.11–13 It has a high success rate with minimal associated morbidity and mortality and is less costly than operative therapy. Numerous embolic agents have been used for embolization of these fistulas. The exact embolic agent to be utilized will depend on the etiology of the fistula. Vessels in malignant lesions such as hepatocellular carcinoma are best occluded with small particle agents, traumatic or iatrogenic arterioportal fistulas may be best managed by embolization with a permanent agent such as coils to achieve a permanent occlusion of the fistula with no likelihood of recanalization.11–13 Utilizing a variety of techniques, especially microcatheters, coils can be deposited in a very selective manner thereby sparing most of the hepatic parenchyma so that inadvertent non target embolization is minimized.12 In summary, we report a case of a chronic arterioportal fistula in a patient with clinical presentation of diarrhea. An MR study was performed, which clearly defined the arterioportal fistula using gadolinium enhanced 3D MRA, and bowel wall edema was well shown using gadolinium enhanced fat suppressed spoiled gradient echo sequence. Treatment with angiographically placed coils occluded the fistula and resulted in resolution of the patient’s diarrhea.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
REFERENCES 1. Puglionisi, A.; Di Giovanni, V.; Snider, F.; Camilli, S.; Cina, G. A propos d’un cas de fistule arterio-veineuse
hepatico-portale. Problemes de physiopathologie et clinique et revue de la litterature. J. Chir. (Paris) 117: 607– 619; 1980. Vauthey, J–N.; Tomczak, J.; Helmberger, T.; et al. The arterioportal fistula syndrome: clinicopathologic features, diagnosis, and therapy. Gastroenterology 113:1390 –1401; 1997. Mathieu, D.; Larde, D.; Vasile, N. CT features of iatrogenic hepatic arterioportal fistulae. J. Comput. Assist. Tomogr. 7:810 – 814; 1983. Endress, C.; Kling, G.A.; Medrazo, B.L. Diagnosis of hepatic artery aneurysm with portal vein fistula using image-directed doppler ultrasound. J. Clin. Ultrasound 17: 206 –208; 1989. Kayser, K.; Marincek, B.; Schlumpf, R.; Fried. M.; Wirth, H.P. Rapidly progressive portal hypertension 23 years after post-traumatic arterioportal fistula of the liver. AJG 91: 1442–1446; 1996. Stone, H.H.; Jordan, W.D.; Acker, J.J.; Martin, J.D. Portal arteriovenous fistulas review and case report. Am. J. Surg. 109:191–196; 1965. Blum, A.; Bazin, C.; Klein, M.; et al. Fistules arterioveineuses spleniques. A propose de deux cas et revue de la litterature. J. Radiology 75:245–252; 1994. Prince, R.P.; Narasimham, D.L.; Stanley, J.C.; Chenevert, T.L.; Williams, D.M.; Marx, V.M.; Cho, K.J. Breath-hold gadolinium enhanced MR angiography of the abdominal aorta and its major branches. Radiology 197:785–792; 1995. Prince, M.R.; Yucel, E.K.; Kaufman, J.A.; Harrison, D.C.; Geller, S.C. Dynamic gadolinium enhanced three-dimensional abdominal MR arteriography. J. Magn. Reson. Imaging 3:877– 881; 1993. Semelka, R.C.; Shoenut, J.P.; Silverman, R.; Kroeker, M.A.; Yaffe, C.; Micklifier, A.B. Bowel disease: prospective comparison of CT and 1.5-T pre and postcontrast MR imaging with T1-weighted fat-suppressed and breath-hold FLASH sequences. J. Magn. Reson. Imaging 1:625– 632; 1991. Appelbaum, N.Y.; Renner, W.J. Steel coil embolization of hepatoportal fistulae. Cardiovasc. Intervent. Radiol. 10:75– 79; 1987. Tarazov, P.G. Intrahepatic arterioportal fistulae: role of transcatheter embolization. Cardiovasc. Intervent. Radiol. 16:368 –373; 1993. Redmond, P.L.; Kumpke, D.A. Embolization of an intrahepatic arterioportal fistula: Case report and review of the literature. Cardiovasc. Intervent. Radiol. 11:274 –277; 1988.
PII S0730-725X(98)00201-X
● Case Report
INTRAHEPATIC ARTERIOPORTAL FISTULA: GADOLINIUM-ENHANCED 3D MAGNETIC RESONANCE ANGIOGRAPHY FINDINGS AND ANGIOGRAPHIC EMBOLIZATION WITH STEEL COILS NUMAN CEM BALCI, RICHARD C. SEMELKA,
AND
JEET S. SANDHU
Department of Radiology, University of North Carolina, Chapel Hill, NC, USA We describe a case of a 59-year-old patient with intrahepatic arterioportal fistula secondary to blunt trauma sustained by a motor vehicle accident 36 years earlier. The fistula was demonstrated 36 years after the accident in a clinical work-up for diarrhea of 1 month’s duration, using contrast enhanced three-dimensional breath-hold MRA. A communication between the dilated portal vein and dilated hepatic artery was shown at the level of distal branches. After subsequent demonstration by conventional angiography, the fistula was embolized using steel coils. Following the therapeutic intervention, the patient’s diarrhea ceased. © 1999 Elsevier Science Inc. Keywords: Arterioportal fistula; Enhanced 3D FISP; Hepatic artery.
exploratory laparotomy and also a partial hepatic resection and repair. Three weeks prior to his recent admission, a cholecystectomy was performed. The cystic artery, and vein were ligated during this procedure: no collateral vessels were identified in the gallbladder wall at surgery. The patient was admitted to our center because of persistent diarrhea for one months duration. Infectious colitis was excluded by stool cultures and screening for ova and parasites. Arterial phase CT scan was performed, which revealed an irregular liver contour, splenomegaly, portal hypertension and a markedly dilated right portal vein branch. The possibility of an arterioportal fistula (APF) was raised. Thickening of the colonic wall was also observed. The patient was referred for a MRI examination for further investigation with an MR angiogram to exclude an APF. All images were obtained on a 1.5 T MR scanner (Vision, Siemens Medical Systems, Iselin, NJ, USA) with the use of a phased array body coil. Gadolinium enhanced MRA was performed using a 3D gradient echo (FISP) sequence. Parameters for the 3D FISP sequence were: TR 5 5 ms/TE 5 2 ms/FA 5 30°/slab thickness 96 mm/number of partitions 5 48/effective slice thickness 2 mm/matrix 5 96 3 256/FOV 5 319 3 425
INTRODUCTION Arterioportal fistulas (APFs) are rare,1 they may be intrahepatic or extrahepatic in location and present major diagnostic and therapeutic challenges. Angiography has been the method of choice in the detection of APFs.2 Reports have shown that ultrasound, computerized tomography (CT), and magnetic resonance angiography (MRA) can all demonstrate APFs,2– 4 however, clear delineation of arterioportal communication using methods other than angiography may be difficult.3,4 With the implementation of gadolinium-enhanced MR angiography, detailed evaluation of abdominal vessels has been shown. To our knowledge no prior report has described the appearance of an arterioportal fistula by gadoliniumenhanced 3D MRA. We present a case of an APF, that was well demonstrated by MRA and subsequently successfully treated with angiographically directed hepatic arterial placement of an embolization coil. CASE REPORT A 59-year-old patient had a history of a motor vehicle accident 36 years ago, following which he underwent an RECEIVED 7/31/98; ACCEPTED 7/22/98. Address correspondence to Dr. Richard C. Semelka, Department of Radiology, UNC School of Medicine, The Univer-
sity of North Carolina, CB# 7510, Chapel Hill, NC 275997510. 475
476
Magnetic Resonance Imaging ● Volume 17, Number 3, 1999
mm/acquisition time 5 26 s breath-hold. A rapid hand injection of 40 mL gadolinium (Magnevist, Berlex, Wayne, NJ, USA) was administered and scanning with the MRA sequence was initiated 10 s after the start of injection. A second pass of 3D FISP was performed, following a 10-s delay. Transverse fat suppressed spoiled gradient echo sequence was performed following the MRA sequence through the upper abdomen. Postprocessing was accomplished using maximum intensity projection (MIP) algorithm. The site of connection between the dilated hepatic artery and dilated portal vein was well shown on a source 2D image from the first pass of the 3D FISP sequence (Fig. 1). MIP reconstruction revealed the full extent of these dilated vessels (Fig. 1). Clear visualization of patent superior mesenteric vein and artery was shown. The gadolinium enhanced fat suppressed spoiled gradient echo images revealed submucosal edema of the colon with prominent serosal and mucosal enhancement (Fig. 1). Following the demonstration of an APF the patient proceeded to angiography for definitive treatment. Using a transfemoral approach, the catheter was advanced into the hepatic artery and a hepatic arteriogram was obtained (Fig. 2), which demonstrated a markedly enlarged anterior right hepatic artery in communication with a branch of the anterior right portal vein. There was hepatofugal flow in the right portal vein and the main portal vein accompanied by retrograde flow in the splenic vein and the superior mesenteric vein (Fig. 2). The right hepatic artery was successfully embolized proximal to the AV fistula, utilizing a combination of 12 and 10 mm Gianturco coils as well as a single 7 mm in diameter Tracker coil. Gelfoam torpedoes and large particles were also utilized to promote thrombosis at the site of coil deployment (Fig. 2). The patient’s clinical symptoms resolved the next day. DISCUSSION Hepatic APFs can be classified into two groups: congenital and acquired.5 Cavernous hemangioma, arteriovenous aneurysm, hereditary teleangiectasia, and Ehler Danlos syndrome are the main causes of congenital APFs. Acquired APFs most commonly arise secondary to trauma or iatrogenic causes. Liver tumors, metastatic lesions to liver, cirrhosis, rupture of preexisting aneurysm are rarer causes of acquired APFs. Symptoms of patients with APF can vary with the size and location of the arterioportal communication. The initial clinical manifestation is usually gastrointestinal bleeding. Ascites and diarrhea, if bowel wall edema develops, are other clinical symptoms.1,2 Our patient presented with diarrhea, and bowel wall edema was well shown on gadolinium enhanced fat suppressed SGE images. Hemodynami-
Fig. 1. A, 2D source image of the gadolinium enhanced 3D FISP in the arterial phase demonstrates the connection between right hepatic artery and right portal vein (arrow). B, MIP reconstruction of the first pass MRA sequence reveals the full extent of the dilated right hepatic artery (long arrow, B) and portal vein (short arrow, B). C, Gadolinium enhanced fat suppressed axial (SGE) image reveals submucosal edema of the colon (arrow) with prominent serosal, and mucosal enhancement.
Intrahepatic arterioportal fistula: MRI findings ● N. C. BALCI
Fig. 2. A, DSA image of hepatic arteriogram reveals a markedly enlarged right hepatic artery (short arrow, A) and communication between the right hepatic artery and right portal vein (long arrow, A). B, Retrograde flow in superior mesenteric vein (arrow) is also visualized. In C, after the placement of Gianturco coils (long arrow, C), the proximal right hepatic artery was thrombosed (short arrow, C). No flow is observed in the fistula.
ET AL.
477
cally compensated shunts, which are not diagnosed at the onset of the fistula, have a characteristic time course as described by Stone et al.6 Gastrointestinal bleeding due to mucosal congestion may occur during the first 3 weeks to 6 months, a quiescent period then ensues, which typically lasts between 6 months to 5 years, during which patients usually live symptom-free for many years. This lengthy symptom-free period was observed in our patient, who was asymptomatic for 36 years following trauma. Because of the low resistance and high capacity of the portal system, a small arterioportal fistula can be accommodated without significant pressure rise, pressure depends directly on the shunt volume and sinusoidal resistance and indirectly on the capacity of the portal vascular bed.6 Once the portal hypertension persists to a moderate degree, the increased pressure in the splanchnic bed leads to typical symptoms related to portal hypertension.6 The increase of the pressure in the portal system may be aggravated by ligation of the cystic vein. In our patient, symptoms of diarrhea secondary to portal hypertension arose following cholecystectomy. It is likely that there may have been a portosystemic collateral pathway via the cystic veins of the gallbladder, which may have allowed some decompression of the elevated pressures within the portal system. With elevated portal pressures, flow reverse in the cystic vein may have then emptied into other mesenteric veins and/or into systemic abdominal veins.6,7 The elimination of this decompressive pathway by cholecystectomy, may have removed the compensating portosystemic shunting resulting in the development of the patient’s symptoms. AFPs are definitively diagnosed by angiography. Previous reports indicate that CT and doppler ultrasound may also successfully demonstrate arterioportal fistulas.3,4 MR angiography using time of flight or phasecontrast technique have been used for the detection of AFPs, however, lengthy examination times and flow dephasing with turbulent flow are problematic.8 The implementation of gadolinium enhanced 3D MRA, has resulted in reliable reproducible good quality MRA studies of abdominal vessels.8,9 The 3D data sampling enables the evaluation of convoluted vessels and complex small vessel pathologies, which may be observed in the setting of fistulas. In our case, a fistula between a distal branch of the hepatic artery and portal vein was shown clearly using this technique. The arterial phase revealed enhancement of both hepatic artery and right portal vein including the mesenteric vein, which suggested the retrograde filling of the right portal vein. Our case showed that contrast enhanced MRA can demonstrate arterioportal fistulas. Comparative studies between imaging modalities (e.g., CT, doppler ultrasound, and MRA) in larger series have to be performed to define the diagnostic value of MRA, and to establish a diagnostic algorithm for patients with arterioportal fistulas. The demonstration of bowel wall
478
Magnetic Resonance Imaging ● Volume 17, Number 3, 1999
diseases has been reported on MR imaging. Gadolinium enhanced T1-weighted fat suppressed images have been effective at demonstrating the bowel wall and revealing submucosal edema in conditions such as ulcerative colitis.10 This MR technique was also effective in our patient, revealing submucosal edema, which we conjectured reflected portal hypertension. In the past, the treatment of arterio-portal fistulas required surgical intervention.2 The type of operation depends on the location and etiology of the fistula. Extrahepatic arterio-portal fistulas can usually be treated by ligation and bypass grafting or primary anastomosis, if technically feasible. Intrahepatic arterio-portal fistulas due to iatrogenic injuries or trauma usually require resection of the involved segment or lobe of the liver. Surgical therapy is associated with significant morbidity and mortality.3,11 With recent advances in interventional techniques, percutaneous embolotherapy has become a very effective method of treating AFPs.11–13 It has a high success rate with minimal associated morbidity and mortality and is less costly than operative therapy. Numerous embolic agents have been used for embolization of these fistulas. The exact embolic agent to be utilized will depend on the etiology of the fistula. Vessels in malignant lesions such as hepatocellular carcinoma are best occluded with small particle agents, traumatic or iatrogenic arterioportal fistulas may be best managed by embolization with a permanent agent such as coils to achieve a permanent occlusion of the fistula with no likelihood of recanalization.11–13 Utilizing a variety of techniques, especially microcatheters, coils can be deposited in a very selective manner thereby sparing most of the hepatic parenchyma so that inadvertent non target embolization is minimized.12 In summary, we report a case of a chronic arterioportal fistula in a patient with clinical presentation of diarrhea. An MR study was performed, which clearly defined the arterioportal fistula using gadolinium enhanced 3D MRA, and bowel wall edema was well shown using gadolinium enhanced fat suppressed spoiled gradient echo sequence. Treatment with angiographically placed coils occluded the fistula and resulted in resolution of the patient’s diarrhea.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
REFERENCES 1. Puglionisi, A.; Di Giovanni, V.; Snider, F.; Camilli, S.; Cina, G. A propos d’un cas de fistule arterio-veineuse
hepatico-portale. Problemes de physiopathologie et clinique et revue de la litterature. J. Chir. (Paris) 117: 607– 619; 1980. Vauthey, J–N.; Tomczak, J.; Helmberger, T.; et al. The arterioportal fistula syndrome: clinicopathologic features, diagnosis, and therapy. Gastroenterology 113:1390 –1401; 1997. Mathieu, D.; Larde, D.; Vasile, N. CT features of iatrogenic hepatic arterioportal fistulae. J. Comput. Assist. Tomogr. 7:810 – 814; 1983. Endress, C.; Kling, G.A.; Medrazo, B.L. Diagnosis of hepatic artery aneurysm with portal vein fistula using image-directed doppler ultrasound. J. Clin. Ultrasound 17: 206 –208; 1989. Kayser, K.; Marincek, B.; Schlumpf, R.; Fried. M.; Wirth, H.P. Rapidly progressive portal hypertension 23 years after post-traumatic arterioportal fistula of the liver. AJG 91: 1442–1446; 1996. Stone, H.H.; Jordan, W.D.; Acker, J.J.; Martin, J.D. Portal arteriovenous fistulas review and case report. Am. J. Surg. 109:191–196; 1965. Blum, A.; Bazin, C.; Klein, M.; et al. Fistules arterioveineuses spleniques. A propose de deux cas et revue de la litterature. J. Radiology 75:245–252; 1994. Prince, R.P.; Narasimham, D.L.; Stanley, J.C.; Chenevert, T.L.; Williams, D.M.; Marx, V.M.; Cho, K.J. Breath-hold gadolinium enhanced MR angiography of the abdominal aorta and its major branches. Radiology 197:785–792; 1995. Prince, M.R.; Yucel, E.K.; Kaufman, J.A.; Harrison, D.C.; Geller, S.C. Dynamic gadolinium enhanced three-dimensional abdominal MR arteriography. J. Magn. Reson. Imaging 3:877– 881; 1993. Semelka, R.C.; Shoenut, J.P.; Silverman, R.; Kroeker, M.A.; Yaffe, C.; Micklifier, A.B. Bowel disease: prospective comparison of CT and 1.5-T pre and postcontrast MR imaging with T1-weighted fat-suppressed and breath-hold FLASH sequences. J. Magn. Reson. Imaging 1:625– 632; 1991. Appelbaum, N.Y.; Renner, W.J. Steel coil embolization of hepatoportal fistulae. Cardiovasc. Intervent. Radiol. 10:75– 79; 1987. Tarazov, P.G. Intrahepatic arterioportal fistulae: role of transcatheter embolization. Cardiovasc. Intervent. Radiol. 16:368 –373; 1993. Redmond, P.L.; Kumpke, D.A. Embolization of an intrahepatic arterioportal fistula: Case report and review of the literature. Cardiovasc. Intervent. Radiol. 11:274 –277; 1988.