Clin J Gastroenterol (2009) 2:43–46 DOI 10.1007/s12328-008-0037-9
CASE REPORT
New type of asymptomatic congenital portosystemic shunt Gabriele Bazzocchi Æ Daniela Pastorelli Æ Fabia Laviani Æ Giovanni Simonetti
Received: 15 July 2008 / Accepted: 2 September 2008 / Published online: 15 November 2008 Ó Springer 2008
Abstract Congenital extrahepatic portosystemic shunt (CEPS) is an extremely rare anomaly. In these malformations splanchnic blood bypasses the liver and drains into the systemic circulation through the inferior vena cava (IVC) or the left renal vein (LRV). Extrahepatic shunts may be divided into type 1 [end-to-side mesenterico-caval fistula with congenital absence of the portal vein (PV)] and type 2 (partial portocaval shunt caused by side-to-side mesenterico-caval fistula with normal or hypoplasic PV). Type 2 shunts typically are wholly extrahepatic between the PV or its right branch and the retrohepatic IVC. This report describes an asymptomatic case of CEPS not previously documented and not classifiable as type 1 or 2. CT revealed a normal PV with communication between the inferior mesenteric vein (IMV) and the LRV. The inferior mesenteric vein appeared tortuous, abnormally long and with a large calibre, and presented a connection with the LRV, in addition to a normal confluence into the splenic vein. Colour Doppler revealed hepatopetal normal flow in the PV and superior mesenteric vein with mild portal hypertension and an inversion of flow in the IMV directed to the LRV. Biochemical parameters showed a normal liver function without hyperammonaemia.
Introduction
Keywords Congenital extrahepatic portosystemic shunt Abernethy malformation Portal hypertension Computed tomography
A 68-year-old man underwent our observation. A CT scan of the thorax and abdomen–pelvis with medium contrast was performed to evaluate a pulmonary nodule diagnosed 3 months before in a CT control of thorax executed for cough and fever. The patient was affected by hepatitis C virus (HCV); thus, the scan was extended to the abdomen to evaluate liver and spleen. The portal vein, intrahepatic branches and superior mesenteric vein (SMV) did not demonstrate anatomic anomalies. The IMV appeared tortuous, abnormally long and with a large calibre, presenting a connection with the
G. Bazzocchi (&) D. Pastorelli F. Laviani G. Simonetti Department of Diagnostic and Molecular Imaging, Interventional Radiology and Radiation Therapy, University of Rome ‘‘Tor Vergata’’, 81 Oxford Street, 00133 Rome, Italy e-mail: [email protected]
Congenital extrahepatic portosystemic shunt (CEPS) was first reported by Abernethy [1]. CEPS is an extremely rare anomaly of the splanchnic venous system. In this anomaly splanchnic blood bypasses the liver and drains into the systemic circulation through the inferior vena cava (IVC) or the left renal vein (LRV). Abernethy malformations are classified as type 1 [endto-side mesenterico-caval fistula with congenital absence of the portal vein (PV)] or type 2 (partial portocaval shunt caused by side-to-side mesenterico-caval fistula with normal PV or hypoplasic PV) [2]. Type 2 shunts typically are wholly extrahepatic between the PV or its right branch and the retrohepatic IVC, but in some cases the shunt traverses the caudate lobe and is partly intrahepatic [3, 4]. This report describes an asymptomatic case of CEPS not classifiable as type 1 or 2 characterised by a normal PV with communication between the inferior mesenteric vein (IMV) and the LRV.
Case report
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LRV, in addition to a normal confluence into the splenic vein (Fig. 1). The liver was normal in size, with an initial grade of fibrosis and with no evidence of focal lesions. The spleen was normal in size, and we observed an additional (accessory) small spleen. Thorax findings revealed a dilatation of the right heart and an enlarged pulmonary vessel. CT did not reveal other anomalies but the patient reported the presence of arteriovenous malformation in the right frontal lobe. Colour Doppler abdominal ultrasonography revealed hepatopetal normal flow in the PV and SMV with mild
portal hypertension and an inversion of flow in the IMV directed to the LRV. A turbulent flow was observed between the confluence of SMV and IMV into the portal circulation. The patient did not show any abdominal symptoms. Laboratories studies reported normal values of the following: total bilirubin (1.1 mg/dl), aspartate aminotransferase (29 IU/l), alanine aminotransferase (27 IU/l), c-glutamyl transferase (17 IU/l), ammonia (55 lmol/l), a-fetoprotein (1.58 IU/ml), albumin (4.5 g/dl), total proteins (7.5 g/dl), INR (1.19), red blood cells (4.8 million/ mm3), haemoglobin (14.5 g/dl) and white blood cells (4.31 x 103 per mm3).
Fig. 1 Oblique maximum intensity projection contrast enhanced CT images (a, b) and volume rendering images (c, d) show the tortuous inferior mesenteric vein (IMV), abnormally long, with a large calibre,
presenting a connection with the left renal vein (LRV), in addition to a normal confluence into the splenic vein (SV). A aorta, ICV inferior cava vein, PV portal vein, SMV superior mesenteric vein
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The ferritin level was slightly low (16.6 ng/ml), and a reduction of platelets (114,000 per ll) was observed.
Discussion Congenital portosystemic venous shunts are rare. They are classified into intrahepatic and extrahepatic shunts [5]. CEPS can be divided into two types. Type 1 occurs much more commonly but not exclusively in girls. Usually the term describes the absence of PV or a venous trunk of variable length formed by the union of splenic and SMV that drains into the typically retrohepatic IVC between a point just inferior to the hepatic vein confluence. There are also described cases of an abnormal PV draining into the intra-abdominal IVC above the level of the hepatic vein confluence and into the right atrium [6, 7]. There are mostly variations of type 1 shunts in which the PV is absent and either the splenic or SMV communicate directly with a systemic vein or the abnormal PV formed from the union of these two veins drains into a systemic vein other than IVC. Associated congenital malformations are common and most frequently are cardiovascular anomalies, biliary atresia, splenic malformations, situs inversus and intestinal malrotation. Type 2 occurs more frequently in boys [5]. Typically the shunt is totally extrahepatic between the PV or its right branch and the retrohepatic IVC. Takayama et al. [4] also described a case in which the shunt crosses the caudate lobe and is partly intrahepatic. The intrahepatic PV may be normal or hypoplasic and type 2 is associated with the same congenital anomalies but less common than with type 1. Patients with either type of congenital portocaval shunt may be asymptomatic, but they are predisposed to two specific complications, namely the development of intrahepatic tumours and hepatic encephalopathy. Hepatic encephalopathy is due to the cerebral effects of circulating toxins which normally undergo first pass metabolism in the liver (galactose, bile acids, ammonia, etc.). The age of onset of encephalopathy is variable but related in part to the volume and duration of the shunt and the presence of concomitant liver disease [8]. Our case presents a normal PV with communication between the IMV and LRV not previously documented. In literature few cases of a direct communication between IMV and common, left or right internal iliac vein have been described [5]. Our patient was asymptomatic; therefore we studied the portal flow only with colour Doppler because the direct measurement of portal pressure is invasive, inconvenient, and clinically impractical. Colour Doppler revealed hepatopetal normal flow in the PV, SMV and SV and an inversion of flow in the IMV directed to the LRV. Probably
45
the majority of flow of the SV shunts through the IMV into the LRV, explaining the turbulence observed between the confluence of SMV and IMV into the portal circulation. The patient is asymptomatic and presents normal laboratory values. This point could be explained because the portal flow shunted through the IMV is prevalently the splenic one. Moreover, IMV drains only the distal colon and rectum, and so this vessel transports much less metabolites than SMV. Dilatation of the right heart and the enlarged pulmonary vessels reveal a condition of pulmonary hypertension that is well known in case of portosystemic shunt. We supposed that this is a congenital CEPS, more slight than types 1 and 2 and so asymptomatic until elderly. The origin of the portorenal shunt is considered congenital if this anomaly occurs without cirrhosis. The extrahepatic shunt between the PV and LRV is mediated by the splenorenal venous anastomosis in the foetal period, and the anastomosis spontaneously closes in the neonatal period. In our case the shunt between the IMV and LRV probably did not close, and this vascular anomaly had been accentuated by chronic liver disease. Associated congenital malformations are common in types 1 and 2. In our case we observed an accessory spleen and an arteriovenous malformation in the right frontal lobe, validating the hypothesis of a congenital origin. Finally, the shunt was too developed to be caused by a mild portal hypertension in an initial grade of fibrosis without other collateral portosystemic shunts or splenomegaly. This condition could also be protective to the development of further collateral portosystemic shunts and their complications as gastrointestinal haemorrhages. As a matter of fact, in literature many studies report that variceal bleeding refractory to medical treatment with beta-blockers and endoscopic therapy can be managed by variceal decompression with either surgical shunts (distal splenorenal, splenocaval, coronary caval, mesocaval) or transjugular intrahepatic portal systemic shunts (TIPS) [9, 10]. In our case the patient probably will not develop other collateral portosystemic shunts and their complications in a short time, because he is a bearer of a natural shunt. Moreover this congenital shunt probably will not close as happens frequently to surgical shunts. Our findings are suggestive for an atypical CEPS not classifiable as type 1 or 2 and never described before between the IMV and LRV.
References 1. Abernethy J. Account of two instances of uncommon formation in the viscera of the human body. Philos Trans R Soc. 1793;83:59–66.
123
46 2. Alvarez AE, Ribeiro AF, Hessel G, Baracat J, ribeiro JD. Abernethy malformation: one of the etiologies of hepatopulmonary syndrome. Pediatr Pulmonol. 2002;34:391–4. 3. Kanamori Y, Hashizume K, Kitano Y, Sugiyama M, Motoi T, Tange T. Congenital extrahepatic portocaval shunt (Abernethy type 2), huge liver mass, and patent ductus arteriosus—a case report of its rare clinical presentation in a young girl. J Pediatr Surg. 2003;38:E15. 4. Takayama Y, Moriura S, Nagata J, Akutagawa A, Hirano A, Ishiguro S, et al. Embolization of the left portal vein to inferior vena cava shunts for chronic recurrent hepatic encephalopathy via the mesenteric vein. J Gastroenterol Hepatol. 2001;16:1425– 8. 5. Stringer MD. The clinical anatomy of congenital portosystemic venous shunts. Clin Anat. 2008;21:147–57. 6. Altavilla G, Cusatelli P. Ultrastructural analysis of the liver with portal vein agenesis: a case report. Ultrastruct Pathol. 1998;22:477–83.
123
Clin J Gastroenterol (2009) 2:43–46 7. Morgan G, Superina R. Congenital absence of the portal vein: two cases and a proposed classification system for portasystemic vascular anomalies. J Pediatr Surg. 1994;29:1239–41. 8. Uchino T, Endo F, Ikeda S, Shiraki K, Sera Y, Matsuda I. Three brothers with progressive hepatic dysfunction and severe hepatic steatosis due to a patent ductus venosus. Gastroenterology. 1997;110:1964–8. 9. Henderson JM, Nagle A, Curtas S, Geisinger M, Barnes D. Surgical shunts and TIPS for variceal decompression in the 1990s. Surgery. 2000;128(4):540–7. 10. Handerson JM, Boyer TD, Kutner MH, Galloway GR, Rikkers LF, Jeffers LJ, et al. Distal splenorenal shunt versus transjugular intrahepatic portal systematic shunt for variceal bleeding: a randomized trial. Gastroenterology. 2006;130(6):1643–51.
CASE REPORT
New type of asymptomatic congenital portosystemic shunt Gabriele Bazzocchi Æ Daniela Pastorelli Æ Fabia Laviani Æ Giovanni Simonetti
Received: 15 July 2008 / Accepted: 2 September 2008 / Published online: 15 November 2008 Ó Springer 2008
Abstract Congenital extrahepatic portosystemic shunt (CEPS) is an extremely rare anomaly. In these malformations splanchnic blood bypasses the liver and drains into the systemic circulation through the inferior vena cava (IVC) or the left renal vein (LRV). Extrahepatic shunts may be divided into type 1 [end-to-side mesenterico-caval fistula with congenital absence of the portal vein (PV)] and type 2 (partial portocaval shunt caused by side-to-side mesenterico-caval fistula with normal or hypoplasic PV). Type 2 shunts typically are wholly extrahepatic between the PV or its right branch and the retrohepatic IVC. This report describes an asymptomatic case of CEPS not previously documented and not classifiable as type 1 or 2. CT revealed a normal PV with communication between the inferior mesenteric vein (IMV) and the LRV. The inferior mesenteric vein appeared tortuous, abnormally long and with a large calibre, and presented a connection with the LRV, in addition to a normal confluence into the splenic vein. Colour Doppler revealed hepatopetal normal flow in the PV and superior mesenteric vein with mild portal hypertension and an inversion of flow in the IMV directed to the LRV. Biochemical parameters showed a normal liver function without hyperammonaemia.
Introduction
Keywords Congenital extrahepatic portosystemic shunt Abernethy malformation Portal hypertension Computed tomography
A 68-year-old man underwent our observation. A CT scan of the thorax and abdomen–pelvis with medium contrast was performed to evaluate a pulmonary nodule diagnosed 3 months before in a CT control of thorax executed for cough and fever. The patient was affected by hepatitis C virus (HCV); thus, the scan was extended to the abdomen to evaluate liver and spleen. The portal vein, intrahepatic branches and superior mesenteric vein (SMV) did not demonstrate anatomic anomalies. The IMV appeared tortuous, abnormally long and with a large calibre, presenting a connection with the
G. Bazzocchi (&) D. Pastorelli F. Laviani G. Simonetti Department of Diagnostic and Molecular Imaging, Interventional Radiology and Radiation Therapy, University of Rome ‘‘Tor Vergata’’, 81 Oxford Street, 00133 Rome, Italy e-mail: [email protected]
Congenital extrahepatic portosystemic shunt (CEPS) was first reported by Abernethy [1]. CEPS is an extremely rare anomaly of the splanchnic venous system. In this anomaly splanchnic blood bypasses the liver and drains into the systemic circulation through the inferior vena cava (IVC) or the left renal vein (LRV). Abernethy malformations are classified as type 1 [endto-side mesenterico-caval fistula with congenital absence of the portal vein (PV)] or type 2 (partial portocaval shunt caused by side-to-side mesenterico-caval fistula with normal PV or hypoplasic PV) [2]. Type 2 shunts typically are wholly extrahepatic between the PV or its right branch and the retrohepatic IVC, but in some cases the shunt traverses the caudate lobe and is partly intrahepatic [3, 4]. This report describes an asymptomatic case of CEPS not classifiable as type 1 or 2 characterised by a normal PV with communication between the inferior mesenteric vein (IMV) and the LRV.
Case report
123
44
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LRV, in addition to a normal confluence into the splenic vein (Fig. 1). The liver was normal in size, with an initial grade of fibrosis and with no evidence of focal lesions. The spleen was normal in size, and we observed an additional (accessory) small spleen. Thorax findings revealed a dilatation of the right heart and an enlarged pulmonary vessel. CT did not reveal other anomalies but the patient reported the presence of arteriovenous malformation in the right frontal lobe. Colour Doppler abdominal ultrasonography revealed hepatopetal normal flow in the PV and SMV with mild
portal hypertension and an inversion of flow in the IMV directed to the LRV. A turbulent flow was observed between the confluence of SMV and IMV into the portal circulation. The patient did not show any abdominal symptoms. Laboratories studies reported normal values of the following: total bilirubin (1.1 mg/dl), aspartate aminotransferase (29 IU/l), alanine aminotransferase (27 IU/l), c-glutamyl transferase (17 IU/l), ammonia (55 lmol/l), a-fetoprotein (1.58 IU/ml), albumin (4.5 g/dl), total proteins (7.5 g/dl), INR (1.19), red blood cells (4.8 million/ mm3), haemoglobin (14.5 g/dl) and white blood cells (4.31 x 103 per mm3).
Fig. 1 Oblique maximum intensity projection contrast enhanced CT images (a, b) and volume rendering images (c, d) show the tortuous inferior mesenteric vein (IMV), abnormally long, with a large calibre,
presenting a connection with the left renal vein (LRV), in addition to a normal confluence into the splenic vein (SV). A aorta, ICV inferior cava vein, PV portal vein, SMV superior mesenteric vein
123
Clin J Gastroenterol (2009) 2:43–46
The ferritin level was slightly low (16.6 ng/ml), and a reduction of platelets (114,000 per ll) was observed.
Discussion Congenital portosystemic venous shunts are rare. They are classified into intrahepatic and extrahepatic shunts [5]. CEPS can be divided into two types. Type 1 occurs much more commonly but not exclusively in girls. Usually the term describes the absence of PV or a venous trunk of variable length formed by the union of splenic and SMV that drains into the typically retrohepatic IVC between a point just inferior to the hepatic vein confluence. There are also described cases of an abnormal PV draining into the intra-abdominal IVC above the level of the hepatic vein confluence and into the right atrium [6, 7]. There are mostly variations of type 1 shunts in which the PV is absent and either the splenic or SMV communicate directly with a systemic vein or the abnormal PV formed from the union of these two veins drains into a systemic vein other than IVC. Associated congenital malformations are common and most frequently are cardiovascular anomalies, biliary atresia, splenic malformations, situs inversus and intestinal malrotation. Type 2 occurs more frequently in boys [5]. Typically the shunt is totally extrahepatic between the PV or its right branch and the retrohepatic IVC. Takayama et al. [4] also described a case in which the shunt crosses the caudate lobe and is partly intrahepatic. The intrahepatic PV may be normal or hypoplasic and type 2 is associated with the same congenital anomalies but less common than with type 1. Patients with either type of congenital portocaval shunt may be asymptomatic, but they are predisposed to two specific complications, namely the development of intrahepatic tumours and hepatic encephalopathy. Hepatic encephalopathy is due to the cerebral effects of circulating toxins which normally undergo first pass metabolism in the liver (galactose, bile acids, ammonia, etc.). The age of onset of encephalopathy is variable but related in part to the volume and duration of the shunt and the presence of concomitant liver disease [8]. Our case presents a normal PV with communication between the IMV and LRV not previously documented. In literature few cases of a direct communication between IMV and common, left or right internal iliac vein have been described [5]. Our patient was asymptomatic; therefore we studied the portal flow only with colour Doppler because the direct measurement of portal pressure is invasive, inconvenient, and clinically impractical. Colour Doppler revealed hepatopetal normal flow in the PV, SMV and SV and an inversion of flow in the IMV directed to the LRV. Probably
45
the majority of flow of the SV shunts through the IMV into the LRV, explaining the turbulence observed between the confluence of SMV and IMV into the portal circulation. The patient is asymptomatic and presents normal laboratory values. This point could be explained because the portal flow shunted through the IMV is prevalently the splenic one. Moreover, IMV drains only the distal colon and rectum, and so this vessel transports much less metabolites than SMV. Dilatation of the right heart and the enlarged pulmonary vessels reveal a condition of pulmonary hypertension that is well known in case of portosystemic shunt. We supposed that this is a congenital CEPS, more slight than types 1 and 2 and so asymptomatic until elderly. The origin of the portorenal shunt is considered congenital if this anomaly occurs without cirrhosis. The extrahepatic shunt between the PV and LRV is mediated by the splenorenal venous anastomosis in the foetal period, and the anastomosis spontaneously closes in the neonatal period. In our case the shunt between the IMV and LRV probably did not close, and this vascular anomaly had been accentuated by chronic liver disease. Associated congenital malformations are common in types 1 and 2. In our case we observed an accessory spleen and an arteriovenous malformation in the right frontal lobe, validating the hypothesis of a congenital origin. Finally, the shunt was too developed to be caused by a mild portal hypertension in an initial grade of fibrosis without other collateral portosystemic shunts or splenomegaly. This condition could also be protective to the development of further collateral portosystemic shunts and their complications as gastrointestinal haemorrhages. As a matter of fact, in literature many studies report that variceal bleeding refractory to medical treatment with beta-blockers and endoscopic therapy can be managed by variceal decompression with either surgical shunts (distal splenorenal, splenocaval, coronary caval, mesocaval) or transjugular intrahepatic portal systemic shunts (TIPS) [9, 10]. In our case the patient probably will not develop other collateral portosystemic shunts and their complications in a short time, because he is a bearer of a natural shunt. Moreover this congenital shunt probably will not close as happens frequently to surgical shunts. Our findings are suggestive for an atypical CEPS not classifiable as type 1 or 2 and never described before between the IMV and LRV.
References 1. Abernethy J. Account of two instances of uncommon formation in the viscera of the human body. Philos Trans R Soc. 1793;83:59–66.
123
46 2. Alvarez AE, Ribeiro AF, Hessel G, Baracat J, ribeiro JD. Abernethy malformation: one of the etiologies of hepatopulmonary syndrome. Pediatr Pulmonol. 2002;34:391–4. 3. Kanamori Y, Hashizume K, Kitano Y, Sugiyama M, Motoi T, Tange T. Congenital extrahepatic portocaval shunt (Abernethy type 2), huge liver mass, and patent ductus arteriosus—a case report of its rare clinical presentation in a young girl. J Pediatr Surg. 2003;38:E15. 4. Takayama Y, Moriura S, Nagata J, Akutagawa A, Hirano A, Ishiguro S, et al. Embolization of the left portal vein to inferior vena cava shunts for chronic recurrent hepatic encephalopathy via the mesenteric vein. J Gastroenterol Hepatol. 2001;16:1425– 8. 5. Stringer MD. The clinical anatomy of congenital portosystemic venous shunts. Clin Anat. 2008;21:147–57. 6. Altavilla G, Cusatelli P. Ultrastructural analysis of the liver with portal vein agenesis: a case report. Ultrastruct Pathol. 1998;22:477–83.
123
Clin J Gastroenterol (2009) 2:43–46 7. Morgan G, Superina R. Congenital absence of the portal vein: two cases and a proposed classification system for portasystemic vascular anomalies. J Pediatr Surg. 1994;29:1239–41. 8. Uchino T, Endo F, Ikeda S, Shiraki K, Sera Y, Matsuda I. Three brothers with progressive hepatic dysfunction and severe hepatic steatosis due to a patent ductus venosus. Gastroenterology. 1997;110:1964–8. 9. Henderson JM, Nagle A, Curtas S, Geisinger M, Barnes D. Surgical shunts and TIPS for variceal decompression in the 1990s. Surgery. 2000;128(4):540–7. 10. Handerson JM, Boyer TD, Kutner MH, Galloway GR, Rikkers LF, Jeffers LJ, et al. Distal splenorenal shunt versus transjugular intrahepatic portal systematic shunt for variceal bleeding: a randomized trial. Gastroenterology. 2006;130(6):1643–51.
