ClinicalRadiology (1990) 42, 203 204
Case Report: Portal Hypertension Secondary to Sigmoid Colon Arteriovenous Malformation R. A. M A N N S , C. R. V I C K E R S , I. M. C H E S N E R , P. M C M A S T E R a n d E. E L I A S
Department of Radiology and Liver Unit, Queen Elizabeth Hospital, Edgbaston, Birmingham A case of portal hypertension secondary to an arteriovenous malformation of the sigmoid colon is presented. The importance of mesenteric angiography in the diagnosis of this condition is discussed. The dramatic clinical improvement in this case following surgery emphasizes that arteriovenous malformations of the gastrointestinal tract represent a potentially curable cause of portal hypertension. Manns, R.A., Vickers, C.R., Chesner, I.M., McMaster, P. & Elias, E. (1990). Clinical Radiology 42, 203-204. Portal H y p e r t e n s i o n Secondary to Sigmoid C o l o n Arteriovenous Malformation Intestinal a r t e r i o v e n o u s m a l f o r m a t i o n , t h o u g h rare, are an i m p o r t a n t cause o f acute gastrointestinal h a e m o r r h a g e and can be difficult to diagnose. We present such a diagnostic p r o b l e m , resolved by angiography, of a p a t i e n t with k n o w n p o r t a l h y p e r t e n s i o n a n d oesophageal varices. A possible aetiological c o m p o n e n t to the d e v e l o p m e n t of portal h y p e r t e n s i o n is discussed. CASE R E P O R T A 33-year-oldcaucasian male presented with melaena and endoscopicallyproven bleeding oesophageal varices. He had longstanding excess alcoholconsumption and was known to have chronic calcificpancreatitis.Splenomegalywas present but there were no stigmata of chronic liver disease. Over the subsequent 6 weeks his varices were obliterated with endoscopic injection sclerotherapy but he continued to have repeated episodes of rectal haemorrhage, consisting of fresh and dark red blood andoccasionalmelaena. The total transfusion requirementsexceeded 30 units. His general condition deteriorated with ascites and muscle wasting. Total parenteral nutrition was instituted. Gastroscopy and colonoscopy on two occasions shortly after epi2 , s0desof actue bleeding failed to reveal an active bleeding site. No blood wasfound in the stomach or duodenum but melaena was present in the colon.A small submucosal bulge in the sigmoidcolon was noted at one colonoscopy but the appearance was non-diagnostic. Rectal varices werenot present. A 99Tcm- labelled red cellradionuclide scan showed no evidenceof luminal activity. During an episode of acute bleeding mesenteric arteriography was performed. This demonstrated a dilated inferior mes-enteric artery supplyingan arterio-venous malformation leading to an early-filling, large inferior mesenteric vein (Fig. 1). No extravasation of contrast medium into the bowel lumen was seen. Following this, further colonoscopyidentified an adherent clot in the sigmoid colon at the site of the previously seen submucosal prominence. A Hartmann's procedure was performed and the grossly enlarged inferiormesentericvein was anastomosed to the inferior vena cava. The liver appeared normal at operation and the portal vein was patent. Wedgebiopsy of the liver showed a normal architecture but with some loose fibrous tissue in portal tracts and a few inflammatory cells. No further bleeding occurred. The patient recovered and was discharged fromhospital. The ascites has since resolved and he has gained weight.
graphy, preferably at the time of acute bleeding, is indicated (Meyer et al., 1981). Sigmoid arteriovenous m a l f o r m a t i o n s are rare. The classical triad of bleeding per rectum, phleboliths on the p l a i n film a n d c u t a n e o u s h a e m a n g i o m a is even less c o m m o n (Stening a n d Hepinstall, 1970). However, it is recognized that in children hepatic a n d gastrointestinal arteriovenous m a l f o r m a t i o n s predispose to the developm e n t of portal h y p e r t e n s i o n ( S h u l m a n et al., 1986). Portal h y p e r t e n s i o n m a y result from increased vascular resistance or increased b l o o d flow. Alcoholic hepatitis a n d cirrhosis are k n o w n to cause portal hypertension b u t wereexcluded in our patient by biopsy taken at the time of l a p a r o t o m y . It appears likely, therefore, that the high flow t h r o u g h the arteriovenous m a l f o r m a t i o n may have been a m a j o r c o m p o n e n t in the aetiology of our patient's p o r t a l hypertension. The resection of the m a l f o r m a t i o n a n d f o r m a t i o n of a n inferior-mesocaval shunt, with c o n s e q u e n t removal of the high flow from the portal circulation, p r o d u c e d rapid resolution of his ascites. V a n W a y et al. (1971) described four cases a n d reviewed a further 57 from the literature in which arteriovenous fistula into the portal circulation resulted in
COMMENT This case raises a n u m b e r o f interesting a n d i m p o r t a n t clinical points. K n o w n oesophageal varices m a y seem a n obvious cause for gastrointestinal haemorrhage. H o w ever, if e n d o s c o p y fails t o identify a source o f active bleeding, other causes such as Meckel's diverticulum, angiodysplasia, small bowel t u m o u r s a n d a r t e r i o v e n o u s tnalformations need to be considered. Mesenteric angioCorrespondence to" R A Manns Department of Radiology, Queen Elizabeth Hospital, Ecigi~asion,Birmingham B15 2TH.
Fig. 1 - This shows a large inferior mesenteric artery (IMA) feedingan arterio-venous malformation (AVM) from which originates a large, early filling, inferior mesentericvein (IMV).
204
CLINICAL RADIOLOGY
portal hypertension. In the majority of these cases the arteriovenous fistula could be ascribed to rupture of a preexisting aneurysm, or secondary to trauma, e.g. surgical, gun-shot wounds and stabbings. In only four of the 61 was the lesion regarded as a naturally occurring malformation including one case of Osler-Weber-Rendu syndrome. The leading cause of death in this series of patients was bleeding varices. Portal hypertension 'resolved' in some, though not all, patients following excision of the fistula. Experimentally, arterialization of the portal vein is known to cause sclerosis of portal venous radicles which increases resistance to portal venous inflow; the fibrosis induced may perpetuate portal hypertension even when portal flow has been restored to normal (Adamson et al., 1975). Foutch and Sivak (1984) reported three patients who bled from rectosigmoid varices after a course of endoscopic sclerosis of oesophageal varices. They attribute this to a complication of sclerotherapy suggesting that occlusion of oesophageal varices may have increased both the chances of developing rectosigmoid varices and the risk of bleeding from them. In our patient the radiological features of a dilated feeding artery, a large tangle of vessels representing the malformation and a densely opacified, early draining ectatic vein are typical of an arteriovenous malformation. Angiodysplasia would have been one of the differential diagnoses in this case but the features of a large lesion with dilated feeding arteries and an ectatic as well as a rapidly draining vein are all in
keeping with an arteriovenous malformation. The Portal vein, in this case, was dilated with normal hepato-portal flow in contradistinction to the often abnormally Small portal veins with hepato-fugal flow which is well-reeog. nised in portal hypertension secondary to a hepatic cause. Auscultation of the abdomen is the simplest and least invasive method of detecting an arteriovenous fistula. This case illustrates the fact that mesenteric arteriovenous fistulae of whatever aetiology, although rare, represent one of the few potentially curable causes of portal hypertension. REFERENCES
Adamson, R J, Arif, S, Babich, A, Butt, K, Lam, A & Minkowitz, S (1975). Arterialization of the liver in combination with a portacaval shunt in the dog. Surgery, Gynaecologyand Obstetrics, 140, 594-600. Foutch, PE & Sivak, MV (1984). Colonic varieeal haemorrhage after endoscopic injection sclerosis of oesophageal varices. A report of three cases. American Journal of Gastroenterology, 79, 756-760. Meyer, CT, Troncale, FJ, Galloway, S & Sheahan, DG (1981). Arteriovenous malformations of the bowel. Medicine, 60, 36-48. Shulman, RJ, Holmes, R, Ferry, GD & Finegold, M (1986). Splanchnic bed vascular malformations and the development of portal hyper. tension. Journal of Paediatric Surgery, 4, 355 357. Stening, SG & Hepinstall, DP (1970). Diffuse cavernous haemangionla of the rectum and sigmoid colon. British Journal of Surgery, 57,186189. Van Way, CW, Crome, MJ, Riddel, DH & Foster, JH (1971). Arteriovenous fistula in the portal circulation. Surgery, 70, 876-890.
Case Report: Portal Hypertension Secondary to Sigmoid Colon Arteriovenous Malformation R. A. M A N N S , C. R. V I C K E R S , I. M. C H E S N E R , P. M C M A S T E R a n d E. E L I A S
Department of Radiology and Liver Unit, Queen Elizabeth Hospital, Edgbaston, Birmingham A case of portal hypertension secondary to an arteriovenous malformation of the sigmoid colon is presented. The importance of mesenteric angiography in the diagnosis of this condition is discussed. The dramatic clinical improvement in this case following surgery emphasizes that arteriovenous malformations of the gastrointestinal tract represent a potentially curable cause of portal hypertension. Manns, R.A., Vickers, C.R., Chesner, I.M., McMaster, P. & Elias, E. (1990). Clinical Radiology 42, 203-204. Portal H y p e r t e n s i o n Secondary to Sigmoid C o l o n Arteriovenous Malformation Intestinal a r t e r i o v e n o u s m a l f o r m a t i o n , t h o u g h rare, are an i m p o r t a n t cause o f acute gastrointestinal h a e m o r r h a g e and can be difficult to diagnose. We present such a diagnostic p r o b l e m , resolved by angiography, of a p a t i e n t with k n o w n p o r t a l h y p e r t e n s i o n a n d oesophageal varices. A possible aetiological c o m p o n e n t to the d e v e l o p m e n t of portal h y p e r t e n s i o n is discussed. CASE R E P O R T A 33-year-oldcaucasian male presented with melaena and endoscopicallyproven bleeding oesophageal varices. He had longstanding excess alcoholconsumption and was known to have chronic calcificpancreatitis.Splenomegalywas present but there were no stigmata of chronic liver disease. Over the subsequent 6 weeks his varices were obliterated with endoscopic injection sclerotherapy but he continued to have repeated episodes of rectal haemorrhage, consisting of fresh and dark red blood andoccasionalmelaena. The total transfusion requirementsexceeded 30 units. His general condition deteriorated with ascites and muscle wasting. Total parenteral nutrition was instituted. Gastroscopy and colonoscopy on two occasions shortly after epi2 , s0desof actue bleeding failed to reveal an active bleeding site. No blood wasfound in the stomach or duodenum but melaena was present in the colon.A small submucosal bulge in the sigmoidcolon was noted at one colonoscopy but the appearance was non-diagnostic. Rectal varices werenot present. A 99Tcm- labelled red cellradionuclide scan showed no evidenceof luminal activity. During an episode of acute bleeding mesenteric arteriography was performed. This demonstrated a dilated inferior mes-enteric artery supplyingan arterio-venous malformation leading to an early-filling, large inferior mesenteric vein (Fig. 1). No extravasation of contrast medium into the bowel lumen was seen. Following this, further colonoscopyidentified an adherent clot in the sigmoid colon at the site of the previously seen submucosal prominence. A Hartmann's procedure was performed and the grossly enlarged inferiormesentericvein was anastomosed to the inferior vena cava. The liver appeared normal at operation and the portal vein was patent. Wedgebiopsy of the liver showed a normal architecture but with some loose fibrous tissue in portal tracts and a few inflammatory cells. No further bleeding occurred. The patient recovered and was discharged fromhospital. The ascites has since resolved and he has gained weight.
graphy, preferably at the time of acute bleeding, is indicated (Meyer et al., 1981). Sigmoid arteriovenous m a l f o r m a t i o n s are rare. The classical triad of bleeding per rectum, phleboliths on the p l a i n film a n d c u t a n e o u s h a e m a n g i o m a is even less c o m m o n (Stening a n d Hepinstall, 1970). However, it is recognized that in children hepatic a n d gastrointestinal arteriovenous m a l f o r m a t i o n s predispose to the developm e n t of portal h y p e r t e n s i o n ( S h u l m a n et al., 1986). Portal h y p e r t e n s i o n m a y result from increased vascular resistance or increased b l o o d flow. Alcoholic hepatitis a n d cirrhosis are k n o w n to cause portal hypertension b u t wereexcluded in our patient by biopsy taken at the time of l a p a r o t o m y . It appears likely, therefore, that the high flow t h r o u g h the arteriovenous m a l f o r m a t i o n may have been a m a j o r c o m p o n e n t in the aetiology of our patient's p o r t a l hypertension. The resection of the m a l f o r m a t i o n a n d f o r m a t i o n of a n inferior-mesocaval shunt, with c o n s e q u e n t removal of the high flow from the portal circulation, p r o d u c e d rapid resolution of his ascites. V a n W a y et al. (1971) described four cases a n d reviewed a further 57 from the literature in which arteriovenous fistula into the portal circulation resulted in
COMMENT This case raises a n u m b e r o f interesting a n d i m p o r t a n t clinical points. K n o w n oesophageal varices m a y seem a n obvious cause for gastrointestinal haemorrhage. H o w ever, if e n d o s c o p y fails t o identify a source o f active bleeding, other causes such as Meckel's diverticulum, angiodysplasia, small bowel t u m o u r s a n d a r t e r i o v e n o u s tnalformations need to be considered. Mesenteric angioCorrespondence to" R A Manns Department of Radiology, Queen Elizabeth Hospital, Ecigi~asion,Birmingham B15 2TH.
Fig. 1 - This shows a large inferior mesenteric artery (IMA) feedingan arterio-venous malformation (AVM) from which originates a large, early filling, inferior mesentericvein (IMV).
204
CLINICAL RADIOLOGY
portal hypertension. In the majority of these cases the arteriovenous fistula could be ascribed to rupture of a preexisting aneurysm, or secondary to trauma, e.g. surgical, gun-shot wounds and stabbings. In only four of the 61 was the lesion regarded as a naturally occurring malformation including one case of Osler-Weber-Rendu syndrome. The leading cause of death in this series of patients was bleeding varices. Portal hypertension 'resolved' in some, though not all, patients following excision of the fistula. Experimentally, arterialization of the portal vein is known to cause sclerosis of portal venous radicles which increases resistance to portal venous inflow; the fibrosis induced may perpetuate portal hypertension even when portal flow has been restored to normal (Adamson et al., 1975). Foutch and Sivak (1984) reported three patients who bled from rectosigmoid varices after a course of endoscopic sclerosis of oesophageal varices. They attribute this to a complication of sclerotherapy suggesting that occlusion of oesophageal varices may have increased both the chances of developing rectosigmoid varices and the risk of bleeding from them. In our patient the radiological features of a dilated feeding artery, a large tangle of vessels representing the malformation and a densely opacified, early draining ectatic vein are typical of an arteriovenous malformation. Angiodysplasia would have been one of the differential diagnoses in this case but the features of a large lesion with dilated feeding arteries and an ectatic as well as a rapidly draining vein are all in
keeping with an arteriovenous malformation. The Portal vein, in this case, was dilated with normal hepato-portal flow in contradistinction to the often abnormally Small portal veins with hepato-fugal flow which is well-reeog. nised in portal hypertension secondary to a hepatic cause. Auscultation of the abdomen is the simplest and least invasive method of detecting an arteriovenous fistula. This case illustrates the fact that mesenteric arteriovenous fistulae of whatever aetiology, although rare, represent one of the few potentially curable causes of portal hypertension. REFERENCES
Adamson, R J, Arif, S, Babich, A, Butt, K, Lam, A & Minkowitz, S (1975). Arterialization of the liver in combination with a portacaval shunt in the dog. Surgery, Gynaecologyand Obstetrics, 140, 594-600. Foutch, PE & Sivak, MV (1984). Colonic varieeal haemorrhage after endoscopic injection sclerosis of oesophageal varices. A report of three cases. American Journal of Gastroenterology, 79, 756-760. Meyer, CT, Troncale, FJ, Galloway, S & Sheahan, DG (1981). Arteriovenous malformations of the bowel. Medicine, 60, 36-48. Shulman, RJ, Holmes, R, Ferry, GD & Finegold, M (1986). Splanchnic bed vascular malformations and the development of portal hyper. tension. Journal of Paediatric Surgery, 4, 355 357. Stening, SG & Hepinstall, DP (1970). Diffuse cavernous haemangionla of the rectum and sigmoid colon. British Journal of Surgery, 57,186189. Van Way, CW, Crome, MJ, Riddel, DH & Foster, JH (1971). Arteriovenous fistula in the portal circulation. Surgery, 70, 876-890.
