Sarin SK(1), Agarwal SR. Extrahepatic portal vein obstruction (EHPVO) is an important cause of noncirrhotic portal hypertension, especially in Third World. Endoscopic Management. S. K. Sarin, Cyriac Abby Philips, Rajeev Khanna tal vein obstruction (EHPVO), noncirrhotic portal fibrosis. (NCPF; or idiopathic PHT. Extrahepatic Portal Vein Obstruction (EHPVO). Non‐Cirrhotic Shiv Kumar Sarin MD, DM. Director Treatment of chronic EHPVO in children.
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Extrahepatic portal venous obstruction EHPVO is the commonest cause of portal hypertension and variceal bleeding in children. Though mortality related to variceal bleeding is uncommon, morbidity due to massive splenomegaly with hypersplenism, growth failure, ectopic varices like rectal varices and portal biliopathy is significant.
A significant proportion of cases in adults are due to procoagulant state but the same has not been documented in children. Studies in children have shown that hereditary or acquired coagulation sarkn do not play a role in the pathogenesis of EHPVO in children.
Regarding endotherapy for variceal bleeding, there is no doubt that band ligation is superior to sclerotherapy. Nevertheless, a combination of band ligation followed by sclerotherapy has shown to be superior to either modality in children with EHPVO. Diminished portal blood flow results in decreased insulin delivery to the liver and thereby decreased production of insulin-like growth sarih IGF-I and insulin-like growth factor binding protein-3 IGFBP Improvement of growth after restoration of hepatic blood flow with mesenteric-left-portal bypass or Rex shunt, has been documented.
Portal biliopathy is universal in adults and common in children but symptomatic ejpvo are mainly in adults; thereby suggesting a progressive nature of the condition. Symptomatic biliary obstruction can be managed endoscopically but shunt surgery followed by biliary bypass if necessary seems to be the best management option.
With the availability of the most physiological shunt mesenteric-left-portal bypass or Rex the management paradigm of EHPVO has changed from endotherapy to primary shunt surgery. Introduction Extrahepatic portal venous obstruction EHPVO is the commonest cause of portal hypertension in children  and one of the common causes in adults in India.
Hence the management of EHPVO is no longer restricted to the management of variceal bleeding alone; it encompasses the management of growth failure, portal biliopathy, colorectal varices, massive splenomegaly with its associated complications like infarction, hypersplenism, physical disability due to pain, early satiety etc. In this article we will discuss the management of EHPVO under the headings of etiology, management of variceal bleeding, ectopic varices, portal biliopathy, growth failure and the role of shunt surgery.
There are many postulated etiologies of EHPVO namely umbilical sepsis, umbilical vein catheterization, abdominal trauma, surgery, intra-abdominal sepsis, dehydration, congenital agenesis or atresia of portal vein.
In another study in 20 children with EHPVO, Dubuisson et al  have shown that almost half of the patients had protein- C, protein-S and anti-thrombin III deficiencies but their levels were normal in all parents, suggesting that these hepvo are not genetic in origin. In a follow up study from our institute we have shown that factor V Leiden and prothrombin gene mutations were uncommon sarib children with EHPVO. In adults, overt or occult primary myeloproliferative disorders MPD are the commonest cause of portal vein thrombosis.
Low hepatic blood flow due to portal vein thrombosis low synthesis and portosystemic shunt increased clearance or consumption are supposed to be responsible for low anticoagulant proteins in blood in EHPVO. The latter mechanism has been further substantiated by the fact that after conventional shunt surgery the levels of anticoagulant proteins tend to further go down.
Though the role of anticoagulation therapy remains controversial in adults,12 there is no role of anticoagulation therapy in children with EHPVO.
Management of esophageal varices. There is no controversy about the management of acute variceal bleeding. After hemodynamic resuscitation all such patients should undergo endotherapy [either sclerotherapy EST or band ligation EVL ]. However, ehpv exists regarding prevention of further bleed.
Management of extra hepatic portal venous obstruction (EHPVO): current strategies
There are two main approaches to prevent further bleed: Whether these patients should have shunt surgery after control of acute bleeding by endotherapy EST or EVL or should undergo further endotherapy for variceal eradication and surveillance is a long-standing debate.
Conventional shunts proximal or distal splenorenal are not possible in ehpbo one-third of cases due to blockage of splenic vein SV or small SV. However, with the availability of new mesenterico-portal mesenterico-left portal-bypass or Rex shunt, the problems of conventional shunts have been largely overcome.
As of now, we do not have sufficient data to say what proportions of EHPVO cases are suitable for this new shunt. Of the two modalities of endotherapy, EST is an established modality to tackle varices in children Table 1. Sarih the other hand, EVL ssarin the advantages of rapid eradication of varices requiring fewer sessions and portending fewer complications. Indeed, EVL has become asrin preferred mode of treatment of variceal bleeding in adults.
Unfortunately, the experience of EVL in children is limited. Nevertheless, EST cannot be totally ruled out as a therapeutic modality, especially in children. EST remains the only therapeutic option in children younger than 2 years of age due to insertion difficulty with a comparatively larger banding cylinder. Endoscopic band ligation followed by sclerotherapy. Despite the clear shpvo benefit of EVL when used alone, there is a higher risk of recurrence of varices as it is difficult to ligate smaller varices, and because perforators and paraesophageal collaterals remain patent after EVL.
Consequently recurrence of varices has been shown to be higher with EVL. By using EVL as a primary treatment, one can achieve rapid eradication or down gradation of varices with fewer complications and by using low-dose EST following EVL, one can block perforators and paraesophageal collaterals, thereby reducing the risk of recurrence.
Variceal recurrence was saarin in both the groups 6.
Consensus on extra-hepatic portal vein obstruction.
Management of gastric varices and portal hypertensive gastropathy. Earlier all attention was concentrated on esophageal varices in EHPVO because the main manifestation was variceal bleeding. Hence, more attention is now being paid to the other effects of portal hypertension on the gastrointestinal tract, namely gastric varices and portal hypertensive gastropathy PHG. The risk of bleeding is more with secondary gastric varices varices appearing after eradication of esophageal varicesisolated gastric varices IGV1 and gastroesophageal varices along the whpvo curvature of stomach GOV2.
This has been substantiated in other studies in children. Acute gastric variceal bleeding can be ehpvoo with tissue ehpov N-acetyl-2butyl- yanoacrylate injection. However, in EHPVO unlike in cirrhosis where cyanoacrylate injection, beta-blockers or TIPS are used in econdary prophylaxis preventing further bleed from gastric varices ,37 large fundal varices are considered as an indication for shunt surgery as it provides a onetime treatment for the disease. Portal hypertensive gastropathy PHG: PHG classically described in cirrhosis.
It may present with occult bleed or as an unusual cause of overt gastrointestinal bleeding. In adults, beta-blockers are recommended for patients who have bled from portal hypertensive gastropathy; and shunts TIPS or surgical are recommended in those patients in whom beta-blockers are contraindicated or have failed. However, if there is bleeding from PHG shunt surgery should be considered as the benefit of long-term beta-blockers in EHPVO in children has not been proven in clinical trials.
Management of colorectal varices. The effect of increased portal pressure in EHPVO is not localized to the esophagus and stomach; it affects the entire gastrointestinal tract.
Further the prevalence of rectal varices is more in EHPVO than in cirrhosis, probably due to the duration of portal hypertension or selective redistribution of portal ssrin along the inferior mesenteric vein consequent to thrombosis at the junction of splenic and superior mesenteric veins. The low prevalence in pediatric studies clearly suggests that the duration of portal hypertension plays an important role in the development of rectal varices. It is expected that the incidence of rectal varices with and without rectal bleeding will rise in children as they approach adolescence and adulthood.
Bleeding from rectal varices can be managed with sclerotherapy or band ligation.
Management of portal biliopathy. Portal biliopathy is the term used to describe cholangiographic abnormalities of the extrahepatic and intrahepatic bile ducts in patients with EHPVO. It has also been observed that while all symptomatic cases are adults but cholangiographic changes are equally evident in both children and adults,25 thereby implying that bile duct disease portal biliopathy in EHPVO may be progressive in nature and would manifest clinically in adulthood.
The postulated mechanisms of biliary changes in EHPVO are extrinsic compression by portal collaterals,[ 44] ischemic stricture of bile duct due to injury at the time of portal venous thrombosis[ 45 ] or a combination of both. In a study of five cases, Dhiman et al [49 ] showed that repeat ERCP done after weeks of shunt surgery demonstrated total disappearance of cholangiographic changes in one, partial disappearance in two and no change in remaining two cases.
This indicates while in some patients compression plays an important role, in others ischemia alone or in combination with compression causes biliary changes. In another study Chaudhary et al  documented relief of jaundice in five of seven patients within weeks of shunt surgery and the remaining two patients required second stage hepaticojejunostomy. This observation again supports the compression theory in most cases of portal biliopathy.
The definitive method of diagnosis of portal biliopathy is ERCP. However, since most of the patients are asymptomatic, this approach is recommended only if a therapeutic intervention is contemplated. Magnetic resonance MR imaging with intravenous gadolinium injection delineate the cavernoma and biliary changes simultaneously and may be extremely useful in children.
Symptomatic portal biliopathy is a definite indication for intervention. Primary biliary tract surgery has significant morbidity and mortality due to extensive collaterals around the bile ducts. Some people believe that shunt surgery should be done first in all cases with symptomatic biliopathy and if it fails to resolve biliary obstruction then second stage biliary surgery is recommended.
Patients with choledocholithiasis and stricture will require multiple sessions of endoscopic therapy with balloon dilatation and stent placement. In patients with endoscopic failure, a staged procedure portosystemic shunt followed by biliary surgery should be preferred. A longer interval up to 1 year and documentation of a patent shunt with decompressed collaterals on color Doppler or MR angiography may help in determining the optimum time for surgery.
The only pediatric study by Gauthier-Villars et al  in 8 children with symptomatic biliopathy in EHPVO showed regression of cholestasis in all cases after shunt surgery mesocaval shunt in 6 and Rex in 2. Following surgery, serum aminotransferases and gamma glutamyl transpeptidase GGT activities returned to normal levels within 1 to 6 weeks in 5 children and remained normal on follow-up from 5 to 15 years.
Liver function tests took 2 to 2. After a follow up of 4. Shunt surgery should be considered for asymptomatic portal biliopathy in presence of another indication like growth failure, symptomatic hypersplenism or ectopic varices. Another study from Lucknow  documented growth retardation height less than 5th percentile for age in This suggests that children with EHPVO have growth failure and decreased growth velocity despite adequate nutrition.
These findings suggest diminished anabolic action of growth hormone on muscle growth affecting the lean muscle mass, and its lipolytic effect resulting in decreased adiposity. The exact mechanism of the growth failure is not known. Two possible mechanisms have been proposed.
On the other hand, the alternate hypothesis suggests that shunting of blood away from the liver results in impaired synthesis of factors needed for normal growth. Significantly increased levels of growth hormone and decreased levels of insulin-like growth factor-1 IGF-1 and insulin-like growth factor binding protein-3 IGFBP-3 have been noted in EHPVO patients, suggesting growth hormone resistance.
Growth parameters have been shown to be improved significantly at 12 and 24 months follow up after restoration of blood flow to the liver and decrease in portal hypertension by mesenterico-left portal vein bypass MLPVB in children.
Growth retardation constitutes a relative indication for mesenterico-portal bypass Rex shunt surgery. Conventionally, medical and endoscopic management is usually recommended for EHPVO, and various surgical shunts are used for refractory or complicated cases.
Surgery is primarily indicated when endotherapy fails to control bleeding, in presence of gastric or ectopic varices not amenable to endoscopic management and with delayed sequelae like portal biliopathy and rectal varices. Emergency shunt surgeries have become a rarity in the era of endoscopic management. Other indications of shunt surgery include symptomatic hypersplenism, growth retardation, portal biliopathy, massive splenomegaly affecting the quality of life, rare blood group, and remote area of residence.
There is no report of post shunt encephalopathy in EHPVO cases and re-bleed occurs only when the shunt is blocked.
Extrahepatic portal vein obstruction.
The mesoportal bypass MPB is a new shunt that restores mesenteric blood flow to the liver through the Rex venous recessus portion of left portal vein joining the umbilical vein.
This is the most physiological shunt as it restores the hepatic blood flow.
Besides correcting portal hypertension, it also abolishes the systemic manifestations of EHPVO such as normalization of coagulation parameters,11 improved liver function  and linear growth. The debate is whether to send a child for shunt surgery preferably Rex shunt immediately after controlling acute variceal bleeding with endotherapy or to continue endotherapy to prevent further bleed and to offer shunt surgery as and when the child needs it.