Meso-portal bypass in children with portal vein thrombosis: rapid increase of the intrahepatic portal venous flow after direct portal hepatic reperfusion

Optimal Treatment for Patients With Cavernous Transformation of the Portal Vein

Cavernous transformation of the portal vein (CTPV) is a sequela of extrahepatic and/or intrahepatic portal vein obstruction caused by a combination of local and risk factors. It was ever taken as a relatively rare disease due to its scant literature, which was mainly based on clinical series and case reports. CTPV often manifests as gastroesophageal variceal bleeding, splenomegaly, and portal biliopathy after the long-term insidious presentation. It is unable for CTPV to be recanalized with anticoagulation because it is a complete obstruction of the mesentericoportal axis. Endoscopic therapy is mainly used for temporary hemostasis in acute variceal bleeding. Meso-Rex shunting characterized by portal-flow-preserving shunts has been widely performed in children with CTPV. The multitude of complications associated with CTPV in adults can be effectively addressed by various interventional vascular therapies. With the ubiquity of radiological examinations, optimal treatment for patients with CTPV becomes important. Multivisceral transplantation, such as liver-small intestinal transplantation, may be lifesaving and should be considered for patients with diffuse mesenteric venous thrombosis.

Value of preoperative computed tomography for meso-Rex bypass in children with extrahepatic portal vein obstruction

Background

Extrahepatic portal vein obstruction (EHPVO) is the most important cause of hematemesis in children. Intrahepatic left portal vein and superior mesenteric vein anastomosis, also known as meso-Rex bypass (MRB), is becoming the gold standard treatment for EHPVO. We analyzed the value of preoperative computed tomography (CT) in determining whether MRB is feasible in children with EHPVO.

Results

We retrieved data on 76 children with EHPVO (50 male, 26 female; median age, 5.9 years) who underwent MRB (n = 68) or the Warren procedure (n = 8) from 2013 to 2019 and retrospectively analyzed their clinical and CT characteristics. The Rex recess was categorized into four subtypes (types 1–4) depending on its diameter in CT images. Of all 76 children, 7.9% had a history of umbilical catheterization and 1.3% had leukemia. Sixteen patients (20 lesions) had associated malformations. A total of 72.4% of Rex recesses could be measured by CT, and their mean diameter was 3.5 ± 1.8 mm (range 0.6–10.5 mm). A type 1, 2, 3, and 4 Rex recess was present in 9.2%, 53.9%, 11.8%, and 25.0% of patients, respectively. MRB could be performed in patients with types 1, 2, and 3, but those with type 4 required further evaluation. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of CT were 100%, 83.8%, 42.1%, 100%, and 85.5%, respectively.

Conclusions

Among the four types of Rex recesses on CT angiography, types 1–3 allow for the performance of MRB.

Effects of Rex-bypass shunt on the cavernous transformation of the portal vein in children: evaluation by the color Doppler ultrasonography

BACKGROUND

The study was to investigate the role of color Doppler ultrasonography in the evaluation of the effect of Rex-bypass shunt on the cavernous transformation of the portal vein (CTPV) in children.

METHODS

Fifty children with symptomatic extrahepatic portal hypertension who received Rex-bypass shunt were retrospectively reviewed, and they were diagnosed with CTPV by ultrasonography. The clinical characteristics were analyzed before and after operation.

RESULTS

Forty-five patients received color Doppler ultrasonography at 6 months after surgery, and good patency in the bypass vessels was displayed. The platelet count significantly increased (P < 0.001) and the esophagogastric varices were improved significantly (p < 0.001). The patency of bypass vessels on color Doppler ultrasonography was consistent with the changes in the platelet count and the degree of esophagogastric varices on gastroscopy before and after operation. The diameter of bypass vessels at 6 months was slightly larger than that at 7 days after operation, and there was no significant difference in blood flow velocity between two time points (P = 0.507).

CONCLUSIONS

Color Doppler ultrasonography can display the patency, diameter, and flow velocity of bypass vessels. It plays an important role in evaluating the effect of Rex-bypass shunt on the CTPV.

Unusual venous collateral pathways allow for reperfusion of the intrahepatic portal venous system in children with portal vein thrombosis after split liver transplantation: Clinical relevance and management implications

PVT is the most frequent vascular complication after LT in small children, and a higher incidence has been observed in those transplanted for biliary atresia or with a LLSG. Thrombosis of the PV causes extrahepatic portal hypertension and is associated with splenomegaly and the development of venous neo-collaterals, including gastro-oesophageal varices and splenorenal shunts. It has also been incidentally suggested in the literature that patients who have had a Roux-en-Y loop for a biliary reconstruction may present with a cavernomatous transformation of the distal portion of the loop. In this study, 13 children with CEPH caused by thrombosis of the PV after LT were analysed. The study evidenced the development of two types of hepatopetal venous networks: (a) a large cavernoma along the Roux loop and around the biliary anastomosis, and (b) a network of neo-collaterals in the gastro-duodeno-pancreatic area that connected to the intrahepatic portal branches directly through the liver capsule. These hepatopetal venous networks between the venous system of the surrounding organs or the omentum and the intrahepatic portal branches can be identified by radiologists. The relevance for the transplanting physician and the transplant surgeon is discussed.

A pilot study using lactulose in management of minimal hepatic encephalopathy in children with extrahepatic portal vein obstruction

BACKGROUND

Minimal hepatic encephalopathy (MHE) is not associated with overt neuropsychiatric symptoms but rather with subtle changes in psychometric and/or neurophysiologic tests. We aimed to diagnose MHE in children with extrahepatic portal vein obstruction (EHPVO) and to evaluate the effect of lactulose on MHE.

METHODS

A prospective study was carried out on 30 patients with EHPVO (21 males; mean age 10±2.5 years). The study was carried out in the Pediatric Hepatology Unit, Cairo University Pediatric Hospital, Cairo, Egypt, between 2011 and 2013. All patients were subjected to clinical and laboratory assessment, neuropsychmetric testing using the arabic version of Wechsler intelligence tests, neurophysiological testing by visual electroencephalogram and P300 event related potentials (ERP).

RESULTS

The prevalence of MHE among children with EHPVO was 20% (6/30). After randomization to treatment and no-treatment groups using lactulose, all tests were repeated after three months. Among four patients with MHE who received lactulose, three (75%) improved. On the other hand, one of the patients in the no-treatment group developed MHE. Only one patient in the treatment arm had to discontinue lactulose because of severe diarrhea.

CONCLUSIONS

This pilot study revealed that the prevalence of MHE was 20%. Improvement on psychometic tests was seen in 75% of our patients (3/4) after treatment with lactulose. Lactulose treatment was well tolerated.

Meso-Rex bypass to manage prehepatic portal hypertension after the failure of an intrahepatic portosystemic stent shunting

A cavernomatous transformation of the extrahepatic portion of the portal vein is a common cause of chronic portal hypertension in children. A few attempts at radiological interventions have been reported, but have rarely been successful. In this report, a surgical Meso-Rex bypass was performed to treat complicated prehepatic portal hypertension, after the insertion of an intrahepatic stent for portosystemic shunting had failed. The review of this case nicely illustrates how differently effective are these two shunting procedures-in terms of restoring hepatopetal flow, managing portal hypertension, and establishing-or not-portosystemic connections.

Intrahepatic portal venous systems in children with noncirrhotic prehepatic portal hypertension: anatomy and clinical relevance

BACKGROUND

Children with extrahepatic portal hypertension typically present with cavernomatous transformation of the portal vein and a poorly defined intrahepatic portal vein system on conventional imaging. With the Meso-Rex Bypass becoming the gold-standard intervention for a cure, a precise assessment of the intrahepatic portal vein system provides helpful data for deciding whether a Meso-Rex Bypass is feasible or not.

METHODS

All children with extrahepatic portal hypertension were prospectively assessed by wedged hepatic venous portography. Venous anatomy was categorized into five subtypes (A to E), depending on the presence of thrombosis in the Rex recessus, or not, and its extension within the intrahepatic portal venous system.

RESULTS

Eighty-nine children entered the study. Previous umbilical vein catheterization is usually associated with Rex thrombosis, while the Rex recessus and the intrahepatic portal venous system are patent in idiopathic cases, thus allowing for the performance of a Meso-Rex Bypass with a good outcome.

CONCLUSIONS

Wedged hepatic venous portography is a very effective tool for detailed preoperative assessment and identification of children being considered for Meso-Rex Bypass surgery. An anatomic-radiological classification is useful in selecting patients for Meso-Rex Bypass with anticipation of a high rate of success.

Pre- and postoperative imaging and interventions for the meso-Rex bypass in children and young adults

The meso-Rex bypass is a physiological and anatomical bypass procedure for relief of extrahepatic portal vein obstruction and restoration of mesenteric venous return to the liver. Most patients who are candidates for the bypass are children or young adults with portal hypertension and hypersplenism secondary to cavernous transformation of the portal vein. Most frequently, the bypass utilizes an autologous venous graft to connect the intrahepatic left portal vein to the infrapancreatic superior mesenteric vein (SMV) re-establishing first-pass portal perfusion. We describe the preoperative imaging of the 92 bypass candidates, the surgical anatomy as reflected in postoperative imaging, and the imaging of bypass complications at our institution.Preoperative imaging with US, CT and MR is directed to demonstrate patency and size of the left portal vein and SMV, to define the extent of cavernous transformation and splanchnic collaterals, and to assess for any associated abdominal vascular or solid organ abnormalities. Postoperative imaging is aimed at diagnosing meso-Rex bypass stenosis or occlusion and the interventional management of these complications.

Recanalized umbilical vein as a conduit for mesenterico/porto-Rex bypass for patients with extrahepatic portal vein obstruction

PURPOSE

Mesenterico-left portal vein (meso-Rex) bypass is as an effective modality for restoring intrahepatic portal perfusion in patients with extrahepatic portal vein obstruction. Achieving sufficient patency is difficult with end-to-side anastomosis of a bypass graft to a small or hypoplastic left portal vein in the Rex recessus. Here, we describe the use of a recanalized umbilical vein in the round ligament as a conduit for bypass construction in two patients.

METHODS

Case 1 was an 11-year-old boy diagnosed with rupture of the esophageal varices and hypersplenism due to congenital extrahepatic portal hypertension. Because of persistent hypersplenism and thrombocytopenia, he underwent meso-Rex bypassing with a left iliac vein graft interposed between the umbilical vein and the superior mesenteric vein. Case 2 was a neonate with a large hepatic tumor (mesenchymal hamartoma) that developed abdominal compartment syndrome at birth. The tumor was removed by right hepatectomy with excision of the portal vein bifurcation at 3 days of age. Porto-Rex bypassing was accomplished by end-to-end anastomosis between the portal vein trunk and the umbilical vein.

RESULTS

Sufficient hepatopetal portal flow through the umbilical vein was achieved in both patients and maintained for over 16 and 13 months, respectively. Although hypersplenism remained in Case 1, intrahepatic portal vein branches gradually widened and the cavernoma in the hepatic hilum disappeared within 2 months. Neither patient had symptoms or signs of portal hypertension at the most recent follow-up.

CONCLUSION

Using the umbilical vein as a vein conduit may facilitate construction of a meso/porto-Rex bypass and restore intrahepatic portal vein perfusion in patients with extrahepatic portal vein obstruction.

Experience with duplex sonographic evaluation of meso-rex bypass in extrahepatic portal vein obstruction

Meso-Rex bypass is a surgical procedure for managing extrahepatic portal vein obstruction in children. Although duplex sonography has been used for assessing the patency of the bypass graft and the changes in the intrahepatic portal venous system after the surgery, there was little sonographic description of functioning and dysfunctioning bypass grafts found in the literature. In this case series, we retrospectively evaluated duplex sonography of functioning and dysfunctioning bypass grafts in 5 pediatric patients who received meso-Rex bypass grafts. Sonography was performed preoperatively and postoperatively within 48 hours, 1 to 2 weeks later, and at follow-up 1 month and up to 3 years later. Changes in the direction and velocity of the flow in the intrahepatic portal veins and bypass grafts and diameters of the grafts and the left portal veins were analyzed. Preoperative sonography revealed varied extension of extrahepatic portal vein occlusion with cavernous transformation and diminished intrahepatic portal venous flow, whereas postoperative studies showed a rapid increase of the intrahepatic portal flow via the meso-Rex bypass graft in all cases. A patent graft with reversed flow in the left portal vein was a predominant feature of a functioning graft. In contrast, absent flow in the graft with diminished flow or an altered flow direction in the left portal vein indicated graft failure. It is believed that duplex sonography provides a valuable tool for monitoring the hemodynamic changes in the portal venous system and detecting graft malfunction.

Extrahepatic portal vein thrombosis after umbilical catheterization: is it a good choice for Rex shunt?

BACKGROUND

Extrahepatic portal vein thrombosis (EHPVT) is an important cause of portal hypertension in children. Rex shunt has been used successfully to treat these patients.

METHODS

We report our experience in 19 infants and children (5 months to 14 years) with HPVT eligible for a mesenteric-portal surgical shunt with left internal jugular vein autograft. Eight children had idiopathic EHPVT, nine had post-umbilical catheterization EHPVT, one had portal vein agenesis, and one had posttransplant EHPVT.

RESULTS

It was possible to perform the Rex shunt in all patients except for 8 of 9 cases in the post-umbilical catheterization EHPVT group. A Warren procedure was performed in 4 of those patients and a proximal splenorenal shunt in 1. Current follow-up ranges from 3 to 26 months. Shunt thrombosis occurred in one patient with portal vein agenesis and associated cardiac anomaly. Portal hypertension has significantly improved after surgery. None of our patients have experienced new bleeding episodes until now.

CONCLUSIONS

The Rex shunt should be considered in the treatment of children with idiopathic EHPVT experiencing repeated gastrointestinal bleeding episodes refractory to endoscopic treatment. Nevertheless, the role of this operation for children with post-umbilical catheterization EHPVT is yet to be clearly evaluated.

Survival among children with portal vein thrombosis and end-stage liver disease

Occlusive PVT concurrent with chronic liver disease is a common clinical entity among pediatric patients referred for transplantation. The natural history of PVT is unknown. Our aim was to determine, using a retrospective cohort design, if children under 13 yr with chronic liver disease and concomitant PVT have an increased mortality risk prior to and after transplantation. A total of 203 patients were included in the study. Nearly 10% of the population had PVT (n = 19); 63.2% of PVT patients (5.9% of total cohort) underwent liver transplantation (n = 12). PVT patients tended to be younger than non-PVT patients at evaluation (1.94 +/- 3.51 vs. 3.79 +/- 4.11, p = 0.059). Clinical and demographic factors were similar between the two groups. Regarding survival, four PVT patients died, of which two had undergone transplantation. Kaplan-Meier analyses indicated that PVT and non-PVT patients had similar survival from the time of evaluation, on the waiting list, and after transplant. Although limited by sample size, our study suggests that a diagnosis of PVT does not increase the mortality risk for children waiting for a liver transplant. Further study is needed to discern variations in mortality risk that may occur in the pediatric chronic liver disease population with PVT.

Mesoportal bypass for extrahepatic portal vein obstruction in children: close to a cure for most!

AIM

Extrahepatic portal vein obstruction (EPVO) is a common cause of portal hypertension in children and can lead to life-threatening bleeding, thrombocytopenia, and coagulation disorders. Mesoportal bypass (MPB) restores normal physiologic portal flow to the liver and corrects portal hypertension. There is, however, little long-term outcome data after MPB. The aim of our study was to analyze the long-term outcome after MPB in children.

METHODS

Retrospective single-center review of all MPB with more than 5-year follow-up was performed in children between 1998 and 2003.

RESULTS

Thirty children underwent MPB, which was successful in 29. Long-term follow-up is available for 24. Median age at the time of bypass was 8.5 years (range, 0.4-14.2 years). Material used for bypass was as follows: left internal jugular vein (n = 20), recanalized umbilical vein (n = 2), gastric vein, and a large colic vein (n = 2). Median time since MPB is 8 years (range, 5.3-8.8 years). One MPB using recanalized umbilical vein thrombosed at 4 months but was successfully refashioned using Gortex. One MPB with left internal jugular vein was thrombosed at 1 year after cardiac surgery. Overall, 23 of 24 children have a patent bypass and resolution of portal hypertension. All showed an decrease in spleen size. Recurrent blood flow in the cavernoma with secondary increase in spleen size occurred in 5 children (median time, 3.4 years after MPB). Further evaluation of these 5 revealed no recurrence of portal hypertension.

CONCLUSION

The MPB provides long-term correction of portal hypertension owing to EPVO. Where technically feasible, MPB is the preferred surgical procedure for treatment of EPVO.

Improved body mass index after mesenterico-portal bypass

Extrahepatic portal hypertension in children secondary to portal vein obstruction is frequently associated with impaired somatic growth. The aim of this study was to assess growth and nutritional status, as reflected by the body mass index (BMI), before and after mesenterico-portal bypass (Rex shunt). Eleven children with a portal vein cavernoma underwent mesenterico-portal bypass using autologous jugular vein. All shunts have remained patent during follow-up periods of 7 months to 5 years. All except one child, who had a normal BMI prior to surgery, demonstrated an increase in their BMI standard deviation scores after surgery. Mean BMI standard deviation scores increased from -0.44 +/- 1.28 (95% CI -1.30 to 0.42) to 0.46 +/- 1.08 (95% CI -0.27 to 1.19), a highly statistically significant increase (P=0.003). Restoration of hepatopetal portal blood flow by mesenterico-portal bypass surgery improves nutrition and growth in children with extrahepatic portal hypertension.

Mesenterico left portal bypass for variceal bleeding owing to extrahepatic portal hypertension caused by portal vein thrombosis

BACKGROUND/PURPOSE

Portosystemic shunt operations are indicated in patients with extrahepatic portal hypertension owing to portal vein thrombosis (EPH-PVT) suffering from recurrent variceal bleeding despite endoscopic sclerotherapy. Mesenterico left portal bypass procedure (MLPB) is an alternative procedure to the portosystemic shunt operations in patients with EPH-PVT. MLPB operation reestablishes hepatopetal portal blood flow. We herein present our experience with MLPB in children with EPH-PVT.

METHODS

Six patients were treated for EPH-PVT with recurrent bleeding despite endoscopic sclerotherapy (2 boys and 4 girls) in our unit. All patients were evaluated preoperatively with complete blood count, portal duplex system Doppler ultrasonography, magnetic resonance angiography, and upper gastrointestinal (GI) endoscopy. MLPB operation was performed as described by de Ville de Goyet. During the postoperative period, patients were evaluated with complete blood count, portal duplex system Doppler ultrasonography, upper GI endoscopy, and magnetic resonance angiography.

RESULTS

Six patients were assessed to be candidates for MLPB procedure and were operated to perform the MLPB procedure. Left portal veins were found to be patent during the operation in 4 patients, and the MLPB procedure was performed. Internal jugular vein was used in 3 patients and enlarged inferior mesenteric vein in 1 patient. Left portal veins of the remaining 2 patients were found to be obliterated; therefore, mesocaval shunt was performed. The postoperative course of the patients was uneventful except for 1 patient. During the following period, the leukocyte and the platelet counts were significantly increased in 3 of the 4 patients after the MLPB procedure. Upper GI bleeding occurred in the early postoperative period in 1 patient with MLPB procedure because of prepyloric ulcer that was successfully treated by endoscopic sclerotherapy. Internal jugular vein graft thrombosis was detected on the 10th postoperative day. This patient underwent a second laparotomy, the distal half of the graft was found to be sclerosed and narrowed that the graft was revised with a synthetic allograft.

CONCLUSIONS

Based on a review of the literature, the MLPB functions well in patients with portal hypertension caused by portal vein thrombosis and appears to have a physiologic advance over shunts that decompress but do not return blood directly to the liver. Because intra-abdominal veins appear to function well as a conduit in this operation, it may be favored by eliminating additional incision and increased risk in such patients.

Correction of extrahepatic portal vein thrombosis by the mesenteric to left portal vein bypass

OBJECTIVE

The goal of this study was to determine the effectiveness of mesenteric vein to left portal vein bypass operation (MLPVB) in correcting extrahepatic portal vein thrombosis (EHPVT) in children. The treatment of idiopathic EHPVT has been primarily palliative, whereas MLPVB restores hepatic portal flow in patients with EHPVT.

METHODS

Thirty-four children with symptomatic EHPVT underwent surgery with intent to perform MLPVB and were followed for up to 7 years. MLPVB was successful in 31 patients (91%), all of whom maintain patent vein grafts and have symptomatic relief of EHPVT in follow-up. All patients had complete relief from gastrointestinal bleeding. Patients with hypersplenism had significant increases in platelet and leukocyte counts and reduction in spleen size. Superior mesenteric vein flow increased from 119 +/- 66 mL/min before bypass to 447 +/- 225 mL/min (P < 0.0001) after surgery. Postoperative blood flow in the bypass graft expressed as a fraction of calculated ideal portal flow for size correlated inversely with age (P < 0.001). Left-portal vein diameter increased from 2.6 +/- 1.6 mm to 7.3 +/- 2.4 mm 2 years after surgery (P < 0.002). Liver volume increased from 703 +/- 349 cm3 to 799 +/- 351 cm3 1 week after surgery (P < 0.001). Prothrombin time improved to normal in all patients 1 year after surgery.

CONCLUSIONS

MLPVB provides excellent relief of symptoms in children with idiopathic EHPVT and results in liver growth and normalization of coagulation parameters. This surgery is corrective and should be done at as early an age as possible.

Transjugular intrahepatic portosystemic shunt for portal vein thrombosis with and without cavernous transformation

BACKGROUND

Treatment options for patients with portal vein thrombosis are limited.

AIM

To evaluate the feasibility and efficacy of transjugular intrahepatic portosystemic shunt for portal vein thrombosis with/without cavernomatous transformation.

METHODS

A survey of such patients, referred for transjugular intrahepatic portosystemic shunt between 1994 and 2005, was performed. Success rates, complications, transjugular intrahepatic portosystemic shunt patency and clinical progression were examined.

RESULTS

Transjugular intrahepatic portosystemic shunt was attempted in 28 patients (13 cirrhotics). Indications were: presurgery/transplantation (2), worsening of ascites (2), variceal bleeding (15 - 8 elective), refractory ascites (3), portal biliopathy (3) and portal vein thrombosis complicating Budd-Chiari syndrome (2). Transjugular intrahepatic portosystemic shunt was placed successfully in 19 of 28 (73%); 23 of 28 had complete portal vein thrombosis and 9 of 23 had cavernous transformation and transjugular intrahepatic portosystemic shunt was successfully placed in six of these. In the 19 patients with transjugular intrahepatic portosystemic shunt, the mean follow-up was 18.1 months (range 5-70): six patients had stent revisions; three had liver transplantation, one died of bleeding. Most cirrhotic patients had an improvement in the Child-Pugh score. In the failed transjugular intrahepatic portosystemic shunt group, two of nine died, and three had further bleeding.

CONCLUSIONS

Transjugular intrahepatic portosystemic shunt should be considered for selected patients with symptomatic complete portal vein thrombosis with/without cavernous transformation, as clinical improvement and less rebleeding occur when transjugular intrahepatic portosystemic shunt placement is successful.

Surgically restoring portal blood flow to the liver in children with primary extrahepatic portal vein thrombosis improves fluid neurocognitive ability

OBJECTIVES

Children with primary extrahepatic portal vein thrombosis (EHPVT) have portal-systemic shunting, which may lead to disturbed neurocognitive function similar to portal-systemic encephalopathy (PSE) seen with chronic liver disease and cirrhosis. The functions most affected are those involving fluid cognitive ability, which comprise neurocognitive domains such as attention, processing speed, and short-term memory, that are particularly vulnerable to systemic illness or diffuse neurologic insult. We determined the fluid cognitive ability of children with EHPVT and whether surgically restoring portal blood flow by mesenteric left portal vein bypass (MLPVB) improved it.

DESIGN

Twelve children with EHPVT and no overt PSE underwent comprehensive neurocognitive testing before and 1 year after undergoing surgery with intent to perform MLPVB. The evaluations sampled 4 functional domains at both time points: (1) neurobehavioral (behavior, emotional, executive functioning); (2) broad cognitive (intelligence, achievement); (3) fluid ability (attention, mental speed, working memory, memory encoding); and (4) visual motor (drawing, fine motor). Tasks in the fluid-ability and visual-motor domains were expected to be especially sensitive to adverse effects of EHPVT and to be most likely to show improvement with MLPVB. The test group consisted of 8 subjects who underwent successful MLPVB, and the comparison group was composed of 3 patients who received distal splenorenal shunts and one whose MLPVB failed.

RESULTS

Both groups demonstrated similar fluid cognitive ability at initial evaluation. Successful MLPVB resulted in significantly improved fluid cognitive function: in the fluid cognitive domain, significant improvements were seen for the hit reaction time variability in the Conner's Continuous Performance Test, the attention scale of the Cognitive Assessment System, and immediate verbal memory in the Children's Memory Scale. In the visual-motor domain, z scores on the Grooved Pegboard Test improved. No improvement was observed in the comparison group.

DISCUSSION

The results show that surgically restoring portal flow to the liver in children with primary EHPVT results in improved fluid cognitive ability. Subjects showed some neurocognitive abnormalities involving mainly fluid cognitive ability consistent with minimal PSE seen in adults with chronic liver disease. Cognitive defects in patients with minimal PSE seem to relate primarily to attention and fine motor skill, and although affected patients can function in everyday life, they are at risk for performance deficits in educational and vocational situations requiring the ability to pay close attention and react quickly (eg, driving, employment in manufacturing). The tests we administered in these domains are pediatric equivalents to measures used to detect minimal PSE in adults and should detect abnormalities in the same functional domains. Our results suggest that a narrow battery of tests could be used to detect minimal PSE in children in a manner similar to the 5-test battery used in adults, eliminating the need for the comprehensive and broad testing we performed. Our findings suggest that shunting of portal blood from the liver in primary EHPVT can result in PSE and question whether it is as benign a disease as previously thought. The importance of our findings is twofold. For understanding the pathophysiology of PSE, we have shown that restoring blood flow to the liver improves cognitive function in children with EHPVT. For therapy for EHPVT, it becomes clear that MLPVB is an excellent treatment option. It is effective for treating the complications of portal hypertension and provides effective portal blood flow that other medical and surgical therapies do not. The findings provide additional evidence that primary EHPVT should be considered curable by MLPVB. However, comparison of overall risks and benefits of MLPVB with those of other therapeutic options and longer-term outcome studies must be completed before MLPVB can be fully endorsed as the best treatment for EHPVT in children.

CONCLUSIONS

Surgical restoration of portal venous flow to the liver in children with primary EHPVT by MLPVB improves fluid cognitive ability. MLPVB should be considered in treating primary EHPVT, because it corrects portal blood flow and could optimize learning potential.

Effectiveness of Rex shunt in the treatment of portal hypertension

BACKGROUND

Children with portal venous thrombosis often have severe symptoms secondary to portal hypertension including recurrent upper gastrointestinal (UGI) bleeds and hypersplenism. We report results of the use of the mesenterico-left portal bypass (Rex shunt) in 5 consecutive patients.

METHODS

A retrospective chart review of all patients with portal venous thrombosis who underwent Rex shunt procedure was performed. Children were evaluated preoperatively with magnetic resonance angiogram, Doppler ultrasound, and mesenteric angiogram. Postoperative ultrasounds were performed in follow-up.

RESULTS

All patients had evidence of portal hypertension and hypersplenism. The average age of the patients was 13.2 +/- 4.9 (7-19) years. The patient had an average of 2.6 +/- 1.7 UGI bleeds requiring banding and 3.4 +/- 4.2 U of blood transfused before undergoing the shunt. The mean operative time was 383 +/- 46 minutes, and length of stay was 10.4 +/- 7.1 days. In follow-up of 18.8 +/- 5.2 months (11-24 months), all but 1 patient had a patent shunt. One narrowed shunt was successfully dilated by percutaneous angioplasty. Thrombocytopenia improved significantly in patients with functioning shunts but did not correlate with a significant decrease in splenic size.

CONCLUSIONS

The Rex shunt reestablishes normal hepatopedal portal flow, and in patients with functioning shunts, no recurrent UGI bleeds or transfusions were required or evidence of encephalopathy were noted.

Recent concepts regarding extra-hepatic portal hypertension

Extra-hepatic portal hypertension (EHPH) defined as non cirrhotic, presinusoidal and prehepatic portal hypertension, with obstruction and cavernomatous transformation of the main portal vein, entails a high, early and prolonged risk of gastro-intestinal bleeding (GIB) mainly from esophageal and/or gastric varices, and less often a risk of cholangiopathy or protein-losing enteropathy. Diagnosis of EHPH may be done with non invasive imaging techniques. Assessment of bleeding risk is based on results of endoscopic examination. Occurence of a bleeding episode or onset during follow-up of endoscopic signs of high risk of GIB require radical eradication of varices. Radical cure of EHPH is achieved at best by bypass surgery restoring a physiological portal flow, and as a second choice by shunt surgery. Endoscopic therapy has a place as first line treatment of GIB episodes, and also in a few cases with poor extrahepatic portal network contra-indicating efficient vascular surgery.

Ileo-caecal arterio-venous malformation associated with extrahepatic portal hypertension: a case report

This paper is a case report describing a boy with Down syndrome and a novel combination of multiple vascular anomalies: extrahepatic portal hypertension, an arterio-venous malformation (AVM) at the ileo-caecal junction, and caval/iliac vein anomalies and developing anal bleeding. We considered that the ileo-caecal AVM would be one of the causes of the repeated hematochezia. The patient underwent ileo-caecal resection with the AVM, and anastomosis of the left external iliac vein and the jejunal branch vein because of the stenosis of the superior mesenteric vein (Clatworthy mesocaval shunt). Intraoperative portal pressure measurement at the site of the right colic vein showed a moderate pressure reduction (42.5-31.5 cm H2O). On the fourth month after operation, gastrointestinal fiberscopy showed no existence of esophageal varices. One year after operation, the patient was doing well without bleeding.