Recent concepts regarding extra-hepatic portal hypertension

Outcomes of Portosystemic Shunts in Children with and without Liver Transplantation

Purpose

Limited data exist regarding outcome and morbidity associated with portosystemic shunts in the pediatric transplant population. Our study assesses the outcomes of pediatric patients who underwent a portosystemic shunt procedure, both with and without liver transplantation (LT).

Methods

This study retrospectively reviewed the medical records of pediatric patients aged 0-19 years who underwent shunt placement between 2003 and 2017 at a tertiary care center. The analysis included cases of shunt placement with or without LT.

Results

A total of 13 pediatric patients were included in the study with median age of 8.8 years. Among the cases, 11 out of 13 (84.6%) underwent splenorenal shunt, 1 (7.7%) underwent a mesocaval shunt, and another 1 (7.7%) underwent a Modified Rex (mesoportal) shunt. Additionally, 5 out of 13 (38.5%) patients had LT, with 4 out of 5 (80.0%) receiving the transplant before shunt placement, and 1 out of 5 (20.0%) receiving it after shunt placement. Gastrointestinal bleeding resulting from portal hypertension was the indication in all cases. A total of 10 complications were reported in 5 patients; the most common complication was anemia in 3 (23.1%) patients. At the most recent follow-up visit, the shunts were functional without encephalopathy, and no deaths were reported.

Conclusion

Shunt placement plays a crucial role in the management of patients with portal hypertension. Our study demonstrates favorable long-term outcomes in pediatric patients who underwent shunt placement. Long term shunt outcomes were similar and unremarkable in patients with LT and without LT.

Surgical management of extrahepatic portal vein obstruction in children: advantages of MesoRex shunt compared with distal splenorenal shunt

PURPOSE

To review surgical management of extrahepatic portal vein obstruction (EHPVO) at Red Cross War Memorial Children's Hospital and compare MesoRex shunt (MRS) with distal splenorenal shunt (DSRS).

METHODS

This is a single-centre retrospective review documenting pre- and post-operative data in 21 children. Twenty-two shunts were performed, 15 MRS and 7 DSRS, over an 18-year period. Patients were followed up for a mean of 11 years (range 2-18). Data analysis included demographics, albumin, prothrombin time (PT), partial thromboplastin time (PTT), International normalised ratio (INR), fibrinogen, total bilirubin, liver enzymes and platelets before the operation and 2 years after shunt surgery.

RESULTS

One MRS thrombosed immediately post-surgery and the child was salvaged with DSRS. Variceal bleeding was controlled in both groups. Significant improvements were seen amongst MRS cohort in serum albumin, PT, PTT, and platelets and there was a mild improvement in serum fibrinogen. The DSRS cohort showed only a significant improvement in the platelet count. Neonatal umbilic vein catheterization (UVC) was a major risk for Rex vein obliteration.

CONCLUSION

In EHPVO, MRS is superior to DSRS and improves liver synthetic function. DSRS does control variceal bleeding but should only be considered when MRS is not technically feasible or as a salvage procedure when MRS fails.

Rex Shunt for Extra-Hepatic Portal Venous Obstruction in Children

Rex shunt, which was first put in use in 1992, has been considered as an ideal surgical method for the treatment of extra-hepatic portal venous obstruction (EHPVO) due to its reconstruction of the hepatopetal portal blood flow. However, despite its long tradition, there are only a few reports about the application and advances in Rex shunt for the treatment of EHPVO in children. In this paper, we summarized the literature related to Rex shunt and discussed the new advances of Rex shunt in the following aspects: surgical method of Rex shunt, the indications of Rex shunt, the strengths of Rex shunt, the effectiveness of Rex shunt, factors affecting the efficacy of Rex shunt, methods that improve the prognosis of Rex shunt, and treatment strategy for recurrence after Rex shunt.

Jejunal varices with extra hepatic portal vein obstruction: A case report

Introduction and importance

Extrahepatic portal vein obstruction (EHPVO) with portal hypertension is rare in children. Intestinal varices as new collaterals accompanying portal hypertension are very rare.

Presentation of case

We report an unusual case of a 12-year-old boy with EHPVO with gastrointestinal bleeding from ectopic jejunal varices, without any gastroesophageal varices.

Discussion

Portal hypertension is the most common cause of EHPVO. Among various ectopic varices, intestinal varices are found distal to the duodenum and present with complaints of hematochezia, melena, or intraperitoneal bleeding. The diagnosis of the EHPVO is aided by imaging investigations like Doppler ultrasound, computed tomography, or magnetic resonance imaging. A multidisciplinary team including gastroenterologists, interventional radiologists, surgeons, and intensivists is crucial in the management of ectopic varices.

Conclusion

Jejunal varices must be considered in the differential diagnosis of gastrointestinal (GI) hemorrhage in patients with a negative source of bleed on upper and lower GI endoscopy.

•

Intestinal varices are rarely developed as new collaterals accompanying portal hypertension with EHPVO (Extrahepatic portal vein obstruction).

•

Jejunal varices must be considered in patients with a negative source of bleed on upper and lower GI endoscopy.

Clinical application of liver stiffness measurement in patients with cavernous transformation of portal vein

The clinical outcomes differ between patients with cavernous transformation of the portal vein (CTPV) with and without cirrhosis. Therefore, invasive liver biopsy may be needed for the differential diagnosis of patients with CTPV with or without cirrhosis. The present study aimed to investigate the diagnostic efficacy of liver stiffness measurements (LSM) for the prediction of cirrhosis in patients with CTPV. A total of 20 patients with CTPV, 34 with chronic hepatitis B (CHB)-related cirrhosis and 20 healthy volunteers, were retrospectively recruited in the study. CTPV was diagnosed with contrast-enhanced computed tomography (CT) and ultrasound for the abdomen. LSM values were detected for each patient, while liver biopsy was performed in each patient in the CTPV and cirrhosis groups. The results demonstrated that LSM values were significantly lower in the CTPV group (12.5 kPa; range, 6.8-21.5 kPa) compared with the CHB-related cirrhosis group (21.0 kPa; range, 15.5-27.2 kPa; P=0.017). However, this was still higher compared with healthy volunteers (4.9 kPa; range 4.0-5.8 kPa; P<0.001). In addition, CTPV patients with cirrhosis (17.7 kPa; range, 13.9-30.8 kPa) exhibited significantly increased LSM values compared with those without cirrhosis (6.4 kPa; range, 5.7-7.8 kPa; P<0.001). Furthermore, LSM values in CTPV patients without cirrhosis were slightly higher compared with those of healthy volunteers (P=0.003), while no statistically significant difference was observed in LSM between CTPV patients with cirrhosis and CHB-related cirrhosis group. These findings indicated that LSM values could be used for the differential diagnosis of CTPV patients with or without cirrhosis. However, further validation studies are needed.

Intrahepatic veno-venous collateralization and misrepresentative hepatic venous pressure gradients in children

BACKGROUND

Accurate and reproducible means of measuring the portosystemic gradient are essential for risk stratification and treatment of portal hypertension.

OBJECTIVE

To report the reliability of hepatic venous pressure gradients in children with intrahepatic veno-venous collateralization.

MATERIALS AND METHODS

Between January 2012 and December 2019 (96 months), 39 patients with native livers underwent wedge hepatic venography and hepatic venous pressure gradient measurements at a tertiary pediatric center. All archived images were reviewed for balloon isolation of the hepatic vein and hepatic vein-to-hepatic vein (HV-HV) collaterals. HV-HV collaterals were categorized as present on the basis of non-catheterized segmental venous opacification despite appropriate balloon isolation. Hepatic venous pressure gradient was defined as the difference of wedge and free hepatic venous pressures. Wedge portosystemic gradient was defined as the difference between wedge hepatic venous pressure and right atrial (RA) pressures. For patients subsequently undergoing portal venous catheterization, portosystemic gradient was defined as the difference between main portal vein and RA pressures.

RESULTS

Thirteen of 39 (33.3%) patients demonstrated HV-HV collaterals on wedge hepatic venography. The mean hepatic venous pressure gradient was 5.2±3.8 mmHg (range: 0-15 mmHg). The mean hepatic venous pressure gradient was 3.6±2.6 mmHg (range: 0-9 mmHg) in the presence of HV-HV collaterals and 5.9±4.2 mmHg (range: 1-15 mmHg) in the absence of HV-HV collaterals (P=0.043). Twelve (30.8%) patients were found to have varices: 10 gastroesophageal, 1 rectal and 1 stomal. The mean hepatic venous pressure gradient in patients with varices was 5.4±47 mmHg (range: 0-15 mmHg). For patients with varices, mean hepatic venous pressure gradient was 3.0±2.7 mmHg (range: 0-9 mmHg) in the presence of HV-HV collaterals and 10.3±4.1 mmHg (range: 5-15 mmHg) in the absence of HV-HV collaterals (P=0.004). Four (10.3%) patients had extrahepatic portal vein occlusion: 3 with cavernous transformation and 1 with type Ib Abernethy malformation. All patients with extrahepatic portal vein occlusion demonstrated HV-HV collaterals compared with 8 of 35 (22.9%) patients without extrahepatic portal vein occlusion (P=0.002). Four of 39 (10.3%) patients underwent direct portal pressure measurements: 3 via transhepatic and 1 via trans-splenic portal access. All had demonstrated HV-HV collaterals on wedged imaging. One had extrahepatic portal vein occlusion. The mean time between wedge portosystemic gradient and portosystemic gradient measurement was 3.75 days (range: 0-8 days). The mean wedge portosystemic gradient was 4.5±3.1 mmHg (range: 2-9 mmHg) and the mean portosystemic gradient was 14.5±3.7 mmHg (range: 12-20 mmHg) (P=0.006).

CONCLUSION

HV-HV collateralization is frequently observed in children undergoing wedged portal venography and leads to misrepresentative hepatic venous pressure gradients. All patients undergoing hepatic venous pressure gradient measurement should have wedged venography to identify HV-HV collaterals and to qualify measured pressures. Additional techniques to obtain representative pressures in the presence of HV-HV collaterals warrant further investigation.

Imaging features and clinical relevance of portal venous systems shown by extrahepatic portal angiography in children with extrahepatic portal venous obstruction

OBJECTIVE

This study investigated the morphologic changes of portal cavernoma in children with extrahepatic portal venous obstruction and explored the relationship with prognosis.

METHODS

From February 2008 to October 2017, there were 107 patients with cavernous transformation of the portal vein admitted to our hospital. Rex shunts were performed in 99 cases, Warren shunts in 7 cases, and laparoscopic splenic vessel ligation in 1 case. Intraoperative superior mesenteric venography was used to determine the structure of the portal venous system. According to the morphologic features of the portal vein shown by portal venography, groups were assigned as follows: patients with the cotton form of portal cavernoma; patients with visible collateral veins of portal cavernoma; patients with and without a visible left gastric vein; and patients with and without a clearly visible intrahepatic portal vein. The preoperative and postoperative portal pressure, preoperative incidence of esophageal varices, time at onset, incidence of postoperative rebleeding, preoperative and postoperative size of the spleen, and age at time of operation were compared between these groups.

RESULTS

The preoperative incidence of esophageal varices, time at onset, postoperative size of spleen, and age at time of operation were significantly lower in the group with the cotton form than in those with visible collateral veins (P < .05). There was a significant correlation between the visible left gastric vein and esophageal varices (P = .002). The time at onset, preoperative and postoperative size of the spleen, and age at time of operation were markedly lower in the group with a good visible intrahepatic portal vein than in those without a clearly visible intrahepatic portal vein (P < .05). The visible left gastric vein was notably associated with the performance of a gastroportal shunt (P = .000), and the group with a visible left gastric vein had a higher ratio of children undergoing a gastroportal shunt.

CONCLUSIONS

The cotton form, an early-stage manifestation of cavernous transformation of the portal vein, typically occurs in younger children with a shorter time to onset. Children with the cotton form of portal cavernoma typically have a better prognosis after Rex shunt.

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.

Pediatric Hepatobiliary Interventions in the Setting of Intrahepatic Vascular Malformations, Portal Hypertension, and Liver Transplant

Within the broad spectrum of pediatric hepatobiliary disorders, hepatic vascular malformations, portal hypertension, and hepatic transplant interventions pose numerous challenges. The role of interventional radiology within each of these conditions is discussed herein, beginning with endovascular management of high flow hepatic vascular malformations. Next, while becoming less common in adult populations, surgical portoportal and portosystemic shunts remain prevalent in many pediatric centers. Shunt anatomy is reviewed along with endovascular management techniques for shunt dysfunction. Next, the growing experience with pediatric transjugular intrahepatic portosystemic shunt placement is reviewed along with tips for success in pediatric patients. Finally, pediatric hepatic transplant interventions are discussed with technical notes pertinent to split liver anatomy.

Endovascular treatment of surgical mesoportal and portosystemic shunt dysfunction in pediatric patients

BACKGROUND

Published data describing the endovascular treatment of dysfunctional mesoportal and portosystemic shunts in the pediatric population are limited.

OBJECTIVE

We sought to describe the treatment and follow-up of such shunts managed by interventional radiology at a single pediatric hospital. We hypothesized that stenotic and occluded pediatric portosystemic and mesoportal shunts can be maintained patent by interventional radiology in the moderate term.

MATERIALS AND METHODS

We conducted a single-center retrospective study at a tertiary pediatric hospital. We included children with surgical mesoportal (meso-Rex) or portosystemic (mesocaval, splenorenal or splenocaval) shunts treated with attempted angioplasty or stenting from 2010 to 2018. Technical success was defined as catheterization and intervention upon the shunt with venographic evidence of flow improvement. The primary outcome variables were shunt patency at 1 month, 6 months, 12 months and 24 months post-procedure and freedom from reintervention.

RESULTS

Twenty pediatric patients (11 boys, 9 girls; mean age 8.25 years, range 1.3-17 years) met inclusion criteria. Fifty-two interventions (primary and reintervention) on 13 splenorenal, 3 meso-Rex, 2 mesocaval and 2 splenocaval shunts were performed because of evidence of shunt failure, including gastrointestinal bleeding, hypersplenism, or radiographic evidence of a flow defect. The 11 stenotic shunts were treated with 100% technical success, while the remaining 9 occluded shunts were treated with 66.7% technical success. The mean number of reinterventions was 1.9 (standard deviation [SD] = 3.1) per child, which did not differ between stenotic and occluded shunts (P=0.24). Primary patency at 1-month, 6-month, 12-month and 24-months follow-up visits was 17/17 (100%), 10/16 (62.5%), 7/15 (46.7%) and 4/10 (40%), respectively. However, 100% of shunts were either primary patent or primary-assisted patent by endovascular reintervention. There were no cases of shunt occlusion following initial technical success. Finally, the median freedom from reintervention duration was 387 days (SD=821 days).

CONCLUSION

Dysfunctional portosystemic surgical shunts are effectively managed by endovascular methods. While many shunts require reintervention, combined primary patency and assisted primary patency rates are excellent.

Multimodality imaging of the Meso-Rex bypass

Extrahepatic portal vein obstruction (EHPVO) is the most common cause of upper gastrointestinal bleeding in children. It is defined as thrombosis of the extrahepatic portal vein with or without extension to the intrahepatic portal veins. The Meso-Rex shunt is the gold standard treatment in children with favorable anatomy since it restores physiological portal liver reperfusion. This is achieved by rerouting the splanchnic venous blood through an autologous graft from the superior mesenteric vein (SMV) into the Rex recess of the left portal vein, curing portal hypertension by doing so. General and hepatobiliary radiologists must be familiar with multimodality imaging appearances of EHPVO and with the role of imaging in identifying suitable candidates for Meso-Rex bypass surgery. Imaging might also detect complications of this procedure, some of which might be treated via interventional radiology.

Hepatic encephalopathy: Sometimes more portal than hepatic

Hepatic encephalopathy is a severe complication of both chronic and acute liver diseases. The term hepatic encephalopathy stems from the belief that hepatic insufficiency is its fundamental etiopathogenic factor. However, most clinical cases show liver failure along with mesenteric venous portal hypertension. This portal hypertension would explain the abnormal mechanical forces suffered by the digestive tract in the early stages of the disorder. These forces could regulate some gut biochemical pathological pathways in a process known as mechanotransduction. Thus, portal hypertension would begin with the establishment of a mechanotransduced afferent or sensory inflammatory gut-brain pathway, resulting in functional and structural changes in the central nervous system. In this review, we will revisit the term "hepatic encephalopathy" in light of new results where portal hypertension occurs before liver failure and is accompanied by brain changes. Moreover, we will point out cellular links that can explain the microbiota, immune, gut, and brain axis disturbances found in this disorder.

Evaluation of Splenic Stiffness in Patients of Extrahepatic Portal Vein Obstruction Using 2D Shear Wave Elastography: Comparison with Intra-Operative Portal Pressure

BACKGROUND/AIMS

To compare splenic stiffness (SS) with intra-operative portal pressures (PPs) in patients of extrahepatic portal vein obstruction (EHPVO).

METHODS

Twenty-one patients (14 males; 7 females) of mean age 20.4 years with clinical and sonographic diagnosis of EHPVO were included in this approved prospective study. Endoscopy for esophageal varices (EV) was done in all patients followed by ultrasonographic 2D shear wave elastography (SWE) of spleen. Three values were taken at different areas of spleen avoiding major vessels and mean was calculated. Intra-operative PP was measured from an omental vein during proximal spleno-renal shunt surgery. The PP was compared and correlated with SS along with other parameters.

RESULTS

The mean SS was 46.04 ± 8.0 kPa and the mean PP was 33.29 ± 4.1 mmHg. There was no significant correlation between PP and SS (P = 0.61) and between grades of EV and SS (P = 0.38). Significant correlation was seen between grades of EV and PP (0.04). SS also did not show significant correlation with splenic size or duration of disease.

CONCLUSION

SS measured by 2D SWE did not correlate with PP and thus may not help in predicting gastrointestinal bleed in patients of EHPVO.

Postoperative enlargement and prognostic effects of portal venous bypass grafts in children undergoing Rex shunt

OBJECTIVE

Patency of the bypass vein after a Rex shunt is an important indicator of prognosis. However, there is no report about the change of caliber of the bypass vein after a Rex shunt. The aim of this study was to identify postoperative changes of the bypass vein and to assess the relationship with prognosis.

METHODS

Between October 2008 and October 2016 in our center, 114 children were diagnosed with extrahepatic portal venous obstruction. The portal cavernoma-portal bypass with interposition of grafted portal vessels was performed in 31 children, the gastroportal shunt was performed in 54 children, and other Rex shunts were performed in another 29 children. At follow-up, the patency and diameter of the bypass vein were assessed with ultrasound and computed tomography. The intraoperative and postoperative diameters of the bypass vein were compared to identify postoperative changes of the bypass vein. Prognosis was compared between children with and children without an enlarged bypass vein.

RESULTS

The caliber of the bypass vein was enlarged in 50% of children (40/80) at 6 months postoperatively. The postoperative incidences of rebleeding and esophageal varices were significantly lower in children with an enlarged bypass vein than in those without (P < .05). Postoperatively, the reduced splenic size was significantly higher in children with an enlarged bypass vein than in those without (P < .05). The postoperative increase in platelet count in children with an enlarged bypass vein was significantly higher than in those without (P = .006). There was no significant difference in the flow velocity of the bypass vein between children with and children without an enlarged bypass vein (P = .133). The portal pressure was significantly reduced after surgery in children with an enlarged bypass vein than in children without an enlarged bypass vein (P = .017).

CONCLUSIONS

The caliber of the bypass vein increases in 50% of children after a Rex shunt using a grafted portal vessel, which is related to a better prognosis.

Diagnosis and treatment guidelines for aberrant portal hemodynamics: The Aberrant Portal Hemodynamics Study Group supported by the Ministry of Health, Labor and Welfare of Japan

Idiopathic portal hypertension (IPH), causing aberrant portal hemodynamics, is a disease with an as yet unidentified cause and no established treatment protocol. The Japanese research group on IPH in Japan was set up in 1975 by the Ministry of Health, Labor and Welfare. Extrahepatic portal obstruction and Budd-Chiari syndrome (BCS) have since been added to the group's research subjects. The aims of the research group are to accurately evaluate the current status of the three diseases in Japan, elucidate their etiology and pathogenesis, and develop new treatments. Due to the long-term efforts of the Japanese research group, aberrant portal hemodynamics has been investigated in a variety of aspects, from epidemiological and pathological studies to molecular biology analyses. As a result, it has been shown that there are abnormal genes in the liver, specific for IPH. In addition, pathological findings of BCS were internationally compared and the difference in findings between Japan and Europe (or North America) has been clarified. Furthermore, it was found that complication rates of hepatocellular carcinoma in BCS were higher in Japan. Based on the research, "Diagnosis and treatment of aberrant portal hemodynamics (2001)", including diagnostic criteria for aberrant portal hemodynamics, was published in 2001. In 2013, it was revised to "Diagnosis and treatment guidelines for aberrant portal hemodynamics (2013)" after the incorporation of diagnosis and treatment in accordance with its current status.

2D Shear Wave Elastography of Liver in Patients with Primary Extrahepatic Portal Vein Obstruction

AIMS

To evaluate liver stiffness (LS) in patients of primary extrahepatic portal vein obstruction (EHPVO) using 2D shear wave elastography (SWE) and compare it with healthy volunteers.

METHODS

Fifty patients (mean age: 22.4 years) of EHPVO and 25 healthy volunteers were included in the study. Liver function tests and viral markers were done in both groups and endoscopy in EHPVO group, followed by ultrasonography and SWE of liver. Liver elastography was done with patients/volunteers in supine position through right intercostal space. The LS for right lobe of liver was recorded in kilopascals. Three such measurements were taken and the mean of both groups were compared. The variables were also correlated with mean LS using Pearson's correlation coefficient in EHPVO group.

RESULTS

There was no significant difference in the mean LS in patients of EHPVO (5.96 kPa) and healthy volunteers (5.47 kPa) (P = 0.093). There was no significant correlation between LS with duration of symptoms, hematemesis, esophageal varices, total bilirubin, serum alkaline phosphatase and aspartate aminotranferase levels in EHPVO group.

CONCLUSION

SWE of liver may be used as a simple additional tool in the diagnosis of patients of EHPVO who show LS values similar to normal liver.

Prevalence and pattern of growth abnormalities in children with extrahepatic portal vein obstruction: Response to shunt surgery

OBJECTIVE

Growth retardation is common in children with extrahepatic portal vein obstruction (EHPVO) and growth hormone (GH) resistance may play a dominant role. The aim of this study was to ascertain growth parameters and growth-related hormones in children with EHPVO, comparing with controls and to study the response of shunt surgery on growth parameters.

MATERIALS AND METHODS

The auxological and growth-related hormone profile (GH; insulin-like growth factor binding protein-3 [IGFBP-3] and IGF-1) of thirty children with EHPVO were compared with controls. The effect of shunt surgery on growth parameters in 12 children was also studied.

RESULTS

The mean height standard deviation score (HSDS) of cases (-1.797 ± 1.146) was significantly lower than that of controls (-0.036 ± 0.796); the mean weight SDS of cases (-1.258 ± 0.743) was also lower than that of controls (-0.004 ± 0.533). The mean GH level of cases (5.00 ± 6.46 ng/ml) was significantly higher than that of controls (1.78 ± 2.04 ng/ml). The mean IGF-1 level of cases (100.25 ± 35.93 ng/ml) was significantly lower as compared to controls (233.53 ± 115.06 ng/ml) as was the mean IGFBP-3 level (2976.53 ± 1212.82 ng/ml in cases and 5183.28 ± 1531.28 ng/ml in controls). In 12 patients who underwent shunt surgery, growth parameters significantly improved.

CONCLUSIONS

Marked decrease in weight and height SDSs associated with GH resistance is seen in children with EHPVO, which improves with shunt surgery.

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.

[Cavernous transformation of the portal vein in children: about 11 cases]

Le cavernome portal est la conséquence d'une occlusion chronique, du système porte extra-hépatique formé d'un réseau de veines dont le calibre est augmenté et au sein desquelles chemine un sang portal hépatopéte. Chez l'enfant, est une cause majeure d'hypertension portale dite «pré ou infra-hépatique» ou encore «extra-hépatique». Onze cas de cavernome porte parmi 78 cas d'hypertension portale ont été colligés au service sur une période allant du Janvier 2003 au Septembre 2012. L’âge de nos patients variait entre 2 et 15 ans et le sexe ratio est de 1,75. Tous nos patients étaient admis au stade d'hypertension portale avec la splénomégalie SMG (100% des cas); hémorragies digestives (63%); ascite (36%); la circulation veineuse collatérale CVC et l'hépatomégalie HMG (27%). L'exploration endoscopique a objectivé la présence de varices ‘sophagiennes dans tous les cas avec une gastropathie hypertensive dans 27% et des varices ectopiques chez 36%. Les perturbations biologiques étaient dominées par la pancytopénie. Le bilan de thrombophilie était demandé pour tous les malades mais réalisé mais n'est réalisé que chez trois revenus normaux chez deux et a objectivé une baisse de protéine S chez le troisième. L’échographie abdominale était le moyen de diagnostic positif et l’écho-doppler a confirmé l'HTP chez tous nos patients. Aucun de nos malades n'a pu être opéré pour le moment. La ligature a été réalisée chez 54,5%. Dix patients ont nécessité une transfusion sanguine. L’évolution globale de nos patients est favorable. La durée moyenne d’évolution du cavernome porte chez nos patients est de quatre ans.

Meso-Rex bypass for extrahepatic portal vein obstruction in children

Background

Meso-Rex bypass (MRB) and portosystemic surgical shunt (PSS) are both used to treat extrahepatic portal vein obstruction (EHPVO) in children. The aim of this study was to analyse the outcome of MRB and PSS to select patients who could benefit from a prophylactic MRB.

Methods

This single-centre retrospective study of children who underwent either MRB or PSS for EHPVO was conducted between 1996 and 2010. Details of patient demographics and preoperative evaluation were collected. Success rates, defined as shunt patency after a minimum of 6 months and clearance of varices or symptoms, were compared. Determinants of outcomes were explored.

Results

Sixty-nine patients underwent a MRB or PSS. Median (interquartile range, i.q.r.) age at surgery was 6·6 (4·0–10·6) years. Twenty-four patients (35 per cent) had had a neonatal umbilical catheter (NUC) placed previously and 47 (68 per cent) had experienced an upper gastrointestinal bleed. Imaging assessment of the intrahepatic left portal vein was considered favourable in 40 patients. Of 43 MRBs attempted, 11 failed during surgery and four patients had persistent thrombosis after a median of 55 (i.q.r. 18–107) months. The success rate of MRB was 60 per cent (26 of 43) compared with 100 per cent (26 of 26) for PSS (P &lt; 0·001). It was lower among patients in whom a NUC had been used (2 of 10 versus 24 of 33; P = 0·004), for procedures undertaken early in the series (6 of 16 versus 20 of 27; P = 0·020) and when the imaging pattern was unfavourable (0 of 5 versus 26 of 38; P = 0·006). On multivariable analysis, only a previous history of NUC predicted failure (P = 0·016).

Conclusion

Prophylactic MRB seems a good treatment option for EHPVO in children, but should be done only by an experienced team in patients with favourable imaging and without a previous history of NUC.

Presented in part to the 43rd Annual Meeting of the American Pediatric Surgical Association, San Antonio, Texas, USA, May 2012

Guidelines for the diagnosis and treatment of extrahepatic portal vein obstruction (EHPVO) in children

INTRODUCTION

Extrahepatic portal vein obstruction is an important cause of portal hypertension among children. The etiology is heterogeneous and there are few evidences related to the optimal treatment.

AIM AND METHODS

To establish guidelines for the diagnosis and treatment of EHPVO in children, a group of gastroenterologists and pediatric surgery experts reviewed and analyzed data reported in the literature and issued evidence-based recommendations.

RESULTS

Pediatric EHPVO is idiopathic in most of the cases. Digestive hemorrhage and/or hypersplenism are the main symptoms. Doppler ultrasound is a non-invasive technique with a high degree of accuracy for the diagnosis. Morbidity is related to variceal bleeding, recurrent thrombosis, portal biliopathy and hypersplenism. Endoscopic therapy is effective in controlling acute variceal hemorrhage and it seems that vasoactive drug therapy can be helpful. For primary prophylaxis of variceal bleeding, there are insufficient data for the use of beta blockers or endoscopic therapy. For secondary prophylaxis, sclerotherapy or variceal band ligation is effective; there is scare evidence to recommend beta-blockers. Surgery shunt is indicated in children with variceal bleeding who fail endoscopic therapy and for symptomatic hypersplenism; spleno-renal or meso-ilio-cava shunting is the alternative when Mesorex bypass is not feasible due to anatomic problems or in centers with no experience.

CONCLUSIONS

Prospective control studies are required for a better knowledge of the natural history of EHPVO, etiology identification including prothrombotic states, efficacy of beta-blockers and comparison with endoscopic therapy on primary and secondary prophylaxis.

Warren shunt combined with partial splenectomy for children with extrahepatic portal hypertension, massive splenomegaly, and severe hypersplenism

PURPOSE

To establish the importance of shunt surgery combined with partial resection of the spleen for selected pediatric patients with extra-hepatic portal vein obstruction (EHPVO), enormous splenomegaly and severe hypersplenism. Severe hypersplenism is often refractory to treatment with endoscopic sclerotherapy or band ligation and shunt surgery; however, to our knowledge, this is the first such study to be published.

METHODS

Distal splenorenal shunt with partial resection of the spleen was performed in 16 of 60 children treated for EHPVO in the Gastroenterology Department of our hospital. Upper gastrointestinal endoscopy had shown esophageal varices of varying grade in all patients and band ligation or endoscopic sclerotherapy had been done for children with a history of bleeding. The indications for surgery were pain and discomfort caused by a large spleen (5-15 cm below the costal margin) and symptomatic hypersplenism with leucopenia, thrombocytopenia, and anemia. Partial resection of the spleen was performed, starting with ligation of the branches and tributaries of the caudal two-thirds. When an ischemic line demarcated the splenic parenchyma, it was transected using electrocautery or LigaSure, leaving 20-30 % of splenic tissue. After the spleen resection, a Warren shunt was performed. Platelet and white blood cell counts and liver function tests were performed before and after the operation. Growth was assessed using SD scores (z scores) for height, weight, and body mass index at the time of surgery and 1 year later.

RESULTS

Postoperative recovery was uneventful and the leukocyte and platelet counts normalized. The shunt patency rate was 100 %. Two cases of shunt stenosis were treated successfully with percutaneous angioplasty. There was no postoperative mortality. During the follow-up period, from 1 to 7 years, all 16 children were asymptomatic, with improved quality of life, growth, and nutrition. No episodes of variceal bleeding, sepsis or encephalopathy occurred.

CONCLUSION

Our results demonstrate that shunt surgery with partial resection of the spleen is effective and safe for pediatric patients with massive splenomegaly and severe hypersplenism secondary to EHPVO.

Surgical management of portal hypertension in children

The management of children with portal hypertension has dramatically changed during the past decade, with an improvement in outcome. This has been achieved by improved efficiency of endoscopic variceal control and the success of liver transplantation. Emergency surgical shunt procedures are rarely required, with acute bleeding episodes generally controlled endoscopically or, occasionally in adults, by interventional radiological procedures. Portosystemic shunts may be considered as a bridge to transplant in adults but are rarely used in this context in children. Nontransplant surgery or radiological interventions may still be indicated for noncirrhotic portal hypertension when the primary cause can be cured and to allow normalization of portal pressure before liver parenchyma is damaged by chronic secondary changes in some specific diseases. The meso-Rex bypass shunt is used widely but is limited to those with a favorable anatomy and can even be performed preemptively. Elective portosystemic shunt surgery is reserved for failure to respond to conservative management in the absence of alternative therapies.

Mesoportal bypass using a constructed saphenous vein graft for extrahepatic portal vein obstruction--technique, feasibility, and outcomes

BACKGROUND

The internal jugular vein is routinely used as a graft for the Rex shunt. We analyzed results of mesoportal bypass using an alternative autologous graft.

METHODS

Twenty-one children with extrahepatic portal vein obstruction were treated with a Rex shunt constructed using both greater saphenous veins. Follow-up included ultrasound and blood count screening at 3, 6, and 12 months and annually thereafter.

RESULTS

Median age was 8.7 years (range, 3.6-14 years), and follow-up time, 5.3 years (range, 0.6-7.1 years). Occlusion or narrowing occurred in 6 patients after a median of 20 months (range, 2.6-52 months). In 2 cases, patency was restored, giving an overall success rate of 81%. During follow-up, no variceal bleeding occurred while hemoglobin, platelet count, and leukocyte levels increased (P ≤ .02 for all) and spleen size decreased (P = .001). Patients with occlusive shunt complications weighed less (P = .01), had higher preoperative platelet levels (P = .02), and tended to have a smaller spleen preoperatively (P = .06) than patients without shunt complications. Cumulative graft patency at 6 months, 1 year, 3 years, and 5 years was 100%, 89%, 82%, and 74%, respectively.

CONCLUSIONS

Rex shunt constructed using the greater saphenous veins is a valuable alternative to the internal jugular vein graft, allowing long-term reversal of portal hypertension, splenomegaly, and hypersplenism. Low patient weight and high platelet count predicted shunt occlusion.

Gastroportal shunt for portal hypertension in children

PURPOSE

Extrahepatic portal venous obstruction is the most common cause of portal hypertension in children. The Rex shunt has been used successfully to treat patients with extrahepatic portal hypertension. In the conventional Rex shunt, the internal jugular vein is used as a venous graft. Inevitably, such a procedure requires neck exploration and sacrifice of internal jugular vein. The authors describe a novel adaptation of gastroportal shunt, successfully carried out in 8 children with extrahepatic portal hypertension.

METHODS

The mean age of the 8 patients (6 boys and 2 girls) was 66.6 months at the time of operation. All children had portal hypertension. Seven had a history of upper gastrointestinal bleeding, and 4 had splenomegaly and hypersplenism. Gastroportal shunt was performed in all patients. The left gastric vein was mobilized and anastomosed to left portal vein. In 1 patient, the left gastric vein was not of adequate length and required a venous graft (the inferior mesenteric vein). All patients were followed up for 3 to 20 months (median, 9 months).

RESULTS

The gastroportal shunt was successfully performed in all patients. The median operative time was 265 minutes (range, 205-360 minutes). Operative blood loss was 21 ± 7.4 mL, and the length of hospital stay varied from 9 to 19 days (median, 15 days). Intraoperative portal venous angiography demonstrated the patency of the shunt in all patients. Postoperatively, the complete blood count normalized, and the biochemistry tests were within reference range. Postoperative ultrasound confirmed shunt patency and satisfactory flow in the gastroportal shunt in each patient. The size of spleen decreased. There was no recurrence of variceal bleeding.

CONCLUSIONS

The gastroportal shunt is an effective treatment of extrahepatic portal hypertension.

Progression of noncirrhotic portal hypertension in a pediatric population

BACKGROUND/OBJECTIVES

The optimal management of children with noncirrhotic portal hypertension is controversial. Some groups suggest early and aggressive surgical intervention, while others report long-term success with conservative management.

METHODS

We conducted a retrospective study of 26 patients with noncirrhotic portal hypertension treated at our institution. We compared platelet counts, white blood cell (WBC) counts, spleen size, hospital admissions, gastrointestinal bleeds, and longitudinal trends of specific clinical parameters using standard univariate and time-trend analytic techniques.

RESULTS

Mean age at the time of diagnosis was 5.2 years. Portal vein thrombosis was found in 84.6% of patients (n=22). There was one mortality related to malignancy. There was not a progression of hypersplenism in patients that did not receive a shunt and conversely, we did not notice a significant decrease in spleen size following shunt surgery (P=0.2). Platelet and WBC counts trended downward among patients managed medically, while platelets increased and WBC counts remained stable in surgical patients. There was a significant decrease in hospital admissions for gastrointestinal bleeding following surgical intervention in the shunt group compared with nonshunt (P=0.0009).

CONCLUSION

While our analysis was limited given small sample sizes and selection bias, it suggests that the majority of pediatric patients with noncirrhotic portal hypertension will do well long-term without surgical intervention.

Imaging the Rex vein preoperatively using wedged hepatic venous portography

BACKGROUND

Mesentericoportal bypass, the Rex shunt, restores the physiological hepatic portal flow and reduces the clinical sequelae of portal hypertension in children with extrahepatic portal vein obstruction (EHPVO). The preoperative evaluation includes an accurate assessment of the portal venous inflow and outflow. The former is readily assessed by ultrasound and MRI, while the outflow intrahepatic portal vein is harder to assess.

PURPOSE

To assess the efficacy of wedged hepatic venous portography (WHVP) at detecting a patent Rex vein preoperatively in children with EHPVO who were considered for mesenterico-portal bypass.

MATERIALS AND METHODS

A single-institution retrospective chart review was undertaken for children with EHPVO who had been considered for a mesoportal bypass between January 2001 and January 2010.

RESULTS

Sixteen children were considered for mesoportal bypass, including four post reduced-size liver transplant patients. Ten children (63%) underwent WHVP. The Rex vein was clearly identified in 8/10 (80%). One Rex vein was seen at surgery but not demonstrated at WHVP. Six mesoportal bypasses were performed without WHVP, of which three (50%) were successful.

CONCLUSION

WHVP had a sensitivity of more than 80% and specificity of 100% in the preoperative patency assessment of the Rex vein.

Splanchnic vein thrombosis in the mediterranean area in children

Abdominal venous thrombosis may present as splanchnic venous thrombosis (SVT) (occlusion of portal, splenic, superior or inferior mesenteric veins) or Budd- Chiari Syndrome (BCS) (thrombosis of inferior vena cava and/or hepatic veins). The aim of this review is to report the scanty data available for SVT in the South Mediterranean area. In one Egyptian study, the possible circumstantial risk factors for portal vein thrombosis (PVT) were found in 30% of cases: 19% neonatal sepsis, 8.7% umbilical catheterization, 6% severe gastroenteritis and dehydration. Another Egyptian study concluded that hereditary thrombophilia was common in children with PVT (62.5%), the commonest being factor V Leiden mutation (FVL) (30%). Concurrence of more than one hereditary thrombophilia was not uncommon (12.5%). The first international publication on hepatic veno-occlusive disease (VOD) in Egypt was in 1965 in children who rapidly develop abdominal distention with ascites and hepatomegaly. This disease was more frequent in malnourished children coming from rural areas; infusions given at home may contain noxious substances that were hepatotoxic and infections might play a role. VOD of childhood is rarely seen nowadays. Data from South Mediterranean area are deficient and this may be attributable to reporting in local medical journals that are difficult to access. Medical societies concerned with this topic could help distribute this information.

Spontaneous meso-portal shunt following orthotopic liver transplantation in a child

Post-transplant children are regularly followed by colour Doppler US exam. Liver parenchyma, biliary tract and portal, subhepatic and arterial vascularisation are checked. We observed a post-transplant child with spontaneous meso-portal bypass after portal vein thrombosis (PVT). After orthotopic liver transplantation (OLT), PVT is frequently observed. When it occurs early (before 3 weeks), it has been identified as a cause of graft failure. On the other hand, late PVT (after 3 weeks) can be extremely well-tolerated, with cavernous transformation of the portal vein and formation of hepatopetal collaterals that deliver blood to the liver. However, extrahepatic portal hypertension (EHPH) and its related complications can develop. Cavernoma transformation is usually seen, but spontaneous shunt is not yet described in transplant patients. Distinction from the classic cavernoma can be achieved by the depiction of a single transcapsular vessel. This bypass partially corrects the EHPH. However it was decided to completely prevent shunt development by performing a surgical mesenterico-left portal vein bypass.

Etiology and long-term outcome of extrahepatic portal vein obstruction in children

AIM: To study the management and outcome of children with extrahepatic portal vein obstruction (EHPVO) in a whole country population.

METHODS: A nationwide multicenter retrospective case series of children with EHPVO was conducted. Data on demographics, radiographic studies, laboratory workup, endoscopic and surgical procedures, growth and development, were extracted from the patients’ charts. Characteristics of clinical presentation, etiology of EHPVO, management and outcome were analyzed.

RESULTS: Thirty patients, 13 males and 17 females, 19 (63.3%) Israeli and 11 (36.7%) Palestinians, were included in the analysis. Age at presentation was 4.8 ± 4.6 years, and mean follow-up was 4.9 ± 4.3 years. Associated anomalies were found in 4 patients. The incidence of EHPVO in Israeli children aged 0-14 years was 0.72/million. Risk factors for EHPVO were detected in 13 (43.3%) patients, including 9 patients (30%) with perinatal risk factors, and 4 patients (13.3%) with prothrombotic states: two had low levels of protein S and C, one had lupus anticoagulant, and one was homozygous for methyltetrahydrofolate reductase mutations. In 56.6% of patients, no predisposing factors were found. The most common presenting symptoms were an incidental finding of splenomegaly (43.3%), and upper gastrointestinal bleeding (40%). No differences were found between Israeli and Palestinian children with regard to age at presentation, etiology and clinical symptoms. Bleeding occurred in 18 patients (60%), at a median age of 3 years. Sclerotherapy or esophageal banding was performed in 20 patients. No sclerotherapy complications were reported. Portosystemic shunts were performed in 11 patients (36.6%), at a median age of 11 (range 3-17) years: splenorenal in 9, mesocaval in 1, and a meso-Rex shunt in 1 patient. One patient underwent splenectomy due to severe pancytopenia. Patients were followed up for a median of 3 (range 0.5-15) years. One patient died aged 3 years due to mucopolysaccharidase deficiency type III. None of the patients died due to gastrointestinal bleeding.

CONCLUSION: EHPVO is a rare disorder. The etiological factors are still mostly unknown, and the endoscopic and surgical treatment options ensure a good long-term prognosis.

Paediatric chronic liver diseases: how to investigate and follow up? Role of imaging in the diagnosis of fibrosis

Chronic liver diseases are rare in children, but encompass a wide spectrum of disorders that may all be complicated by liver fibrosis and therefore by portal hypertension. They may be classified according to the level of portal flow obstruction: prehepatic, intrahepatic or suprahepatic. Most of them, except presinusoidal diseases, may progress to cirrhosis that carries additional risks of impaired liver function and development of hepatocellular carcinoma. Imaging plays an important role in guiding the diagnosis and biopsy and for follow-up during treatment. US, with high-frequency transducers and Doppler, is the first modality of choice, directs the rest of the investigations and guides interventional radiology. MDCT has made great progress and has replaced angiography for diagnostic purposes. MRI is indicated for parenchyma and nodule characterization and for biliary tract evaluation. To avoid liver biopsy, several elasticity imaging techniques have been developed and have to be evaluated for accuracy and convenience in children. The role of each modality with main imaging findings is described in extrahepatic portal vein obstruction, hepatoportal sclerosis, congenital hepatic fibrosis, cirrhosis and Budd-Chiari syndrome.

Modified technique of meso-Rex shunt in case of insufficient length of the jugular vein graft

Meso-Rex shunt (MRS) can relieve portal hypertension and restore a physiological portal flow in patients with portal vein thrombosis. We describe a technical variant where the autologous internal jugular vein (IJV) was too short to bridge the superior mesenteric vein (SMV) and the Rex recessus.

PATIENT

A 15-year-old boy with portal cavernoma had several episodes of gastrointestinal bleeding despite repeated sclerotherapy. Preoperative assessment, including retrograde transjugular portography, showed persistent esophageal and gastric varices, severe hypertensive gastropathy, obstructed portal vein, patent SMV and splenomesenteric confluence, patent intrahepatic portal branches, and normal transhepatic pressure gradient. An MRS was planned. The left IJV was retrieved from its infracranial part to its confluence with subclavian vein. After performing the Rex recessus to IJV graft anastomosis, the IJV graft proved to be too short for classical end-to-side anastomosis onto the SMV. After clamp testing showing good tolerance of the small bowel, the proximal jejunal branches of the SMV were tied, the proximal SMV was mobilized and transsected 4 cm below the pancreas, and an end-to-end anastomosis between SMV and IJV was performed. Portal pressure decreased from 23 to 13 mm Hg, and intraoperative Ultra Sound Doppler (US Doppler) showed good flows in the shunt. Postoperative course was uneventful, and 1 year after surgery, the child is clinically well, off medication, with a patent shunt, and no portal hypertension.

CONCLUSION

This modified MRS technique may be useful when the autologous IJV graft is too short, avoiding the need for prosthetic conduits and prolonged postoperative anticoagulation.

Advances in research on portal hypertensive enteropathy

Portal hypertensive enteropathy, whose fundamental pathologic change is a vasculopathy characterized histopathologically by mucosal and submucosal vessel dilatation, oedema and congestion, mainly results from a combination of increased intrahepatic vascular resistance and increased blood flow through the portal venous system. Though portal hypertensive enteropathy usually has non-specific clinical manifestations, it is a major cause of lower gastrointestinal bleeding. Up to now, there has been no standard for the diagnosis and grading of portal hypertensive enteropathy. Unfortunately, the experience of treatment for portal hypertensive enteropathy only comes from some small-sample trials. For these reasons, an in-depth study of portal hypertensive enteropathy is still necessary. In this article, we will review the advances in research on portal hypertensive enteropathy.

Liver nodules after portal systemic shunt surgery for extrahepatic portal vein obstruction in children

BACKGROUND

Liver nodules have been reported after portal systemic shunt surgery (PSSS) in animal experiments or in humans with liver cirrhosis. The aim of our study was to assess the incidence of liver nodules after surgery for extrahepatic portal vein obstruction (EHPVO) in children without associated liver disease.

METHODS

We retrospectively reviewed the charts of 45 children who had surgery from 1979 to 2005 for EHPVO in our institution, consisting of 38 PSSS and 7 portal reperfusion procedures (PRPs). We assessed the presence of liver nodules on ultrasonography.

RESULTS

Of 45 patients, 7 (15%) had liver nodules during a median of 80 months of follow-up. All the nodules occurred after PSSS. Five nodules were subjected to biopsy; we found 2 liver cell adenomas and 3 focal nodular hyperplasias.

CONCLUSIONS

In this study, liver nodules occurred in 18% of cases after PSSS for EHPVO in children and not after PRP. As many children have undergone PSSS throughout the world, the presence of liver nodules should be considered during the follow-up of those patients.

Systemic and pulmonary hemodynamics in patients with extrahepatic portal vein obstruction is similar to compensated cirrhotic patients

BACKGROUND

Patients with cirrhosis and portal hypertension exhibit a hyperdynamic circulation manifesting as increased cardiac output, heart rate and plasma volume; and decreased arterial blood pressure, systemic vascular resistance, and pulmonary vascular resistance. It is believed that these changes are related to both hepatocellular dysfunction and portal hypertension. However, the role of portal hypertension per se in producing these changes in circulation has not been clear. Extrahepatic portal vein obstruction (EHPVO), a vascular disorder of the liver characterized by cavernomatous transformation of the main portal vein, is an excellent model to study the role of portal hypertension per se in producing these changes because there is no hepatic dysfunction in EHPVO. The main aim of our study was, therefore, to evaluate alterations of systemic and pulmonary vascular systems in patients with EHPVO and compare them with patients with compensated cirrhosis.

PATIENTS AND METHODS

Consecutive patients of EHPVO, 15 years or older, and past variceal bleeders were studied. For comparison, consecutive patients with compensated cirrhosis and history of variceal bleed, matched for variceal status, and body surface area were included. The hemodynamic studies included the measurements of cardiac index (by Fick's oxygen method), and systemic and pulmonary vascular resistance indices.

RESULTS

Fifteen patients of EHPVO and same number of controls (compensated cirrhotics) were included in the study. The baseline parameters in the two groups were comparable. Both EHPVO patients and cirrhotics had similar values in all the measured systemic and pulmonary hemodynamic parameters. The median (range) cardiac index in EHPVO was 3.8 (2.3-7.7) l min(-1) m(-2), whereas it was 4.4 (2.8-8.9) l min(-1) m(-2) in cirrhosis (P = 0.468). The median (range) systemic vascular resistance index in EHPVO was 1,835 (806-3400) dyne s cm(-5) m(-2), which was similar to that in cirrhotic patients (1,800 [668-3022], P = 0.520). Similarly, the values of median (range) pulmonary vascular resistance index were comparable in the two groups (71 [42-332] vs. 79 [18-428], P = 0.885). A subgroup analysis was done for 8 patients of EHPVO and 8 age-matched compensated cirrhotic patients, which also revealed similar values of cardiac index, cardiac output, systemic vascular resistance index, systemic vascular resistance, pulmonary vascular resistance index, and pulmonary vascular resistance in the two groups.

CONCLUSIONS

EHPVO patients have hyperdynamic circulation manifested by high cardiac index and low systemic and pulmonary vascular resistance indices. These hemodynamic changes are comparable with compensated cirrhotic patients who have similar grade of portal hypertension. This suggests a predominant role of portal hypertension per se in the genesis of systemic and pulmonary hemodynamic alterations.

Aetiology and management of extrahepatic portal vein obstruction in children: King's College Hospital experience

OBJECTIVE

To study a single-centre experience of the management of extrahepatic portal vein obstruction (EHPVO) in children during the last 3 decades.

MATERIALS AND METHODS

The medical records of 108 children (67 male, median age 4.75 years, range = 1 day-16.3 years) presenting with EHPVO between 1979 and 2005 were reviewed retrospectively.

RESULTS

Extended prothrombotic screening performed in 30 patients revealed low protein C activity (6 patients), low free protein S (2), and a positive lupus anticoagulant (1); factor V Leiden mutations and the JAK2V617F mutation were not identified. Associated congenital anomalies were found in 26 of the 108 children (24%). Clinical presentation included splenomegaly in 98 (91%) and ascites in 3 (3%). Elevation of liver enzymes and prolonged international normalized ratio were seen in 13 (12%) and 14 (13%) children, respectively. Haematological parameters of hypersplenism were present in 13 (12%). Bleeding occurred in 83 (77%) patients with a median age of 4.58 (0.02-16.37) years. On first endoscopy, oesophageal varices were present in 92 patients; of those subjects, 70 (76%) received sclerotherapy, 5 (5%) had band ligation, and 16 (17%) received both. Complications of endoscopy occurred in 34 (37%) patients: oesophageal ulcers in 16, oesophageal stricture in 10, both in 7, and erosive gastritis in 1. Seventeen (16%) children underwent shunt surgery for uncontrolled bleeding at a median age of 9.7 (5.2-23.7) years.

CONCLUSIONS

The aetiology of EHPVO in the majority of patients remains unknown. Sclerotherapy and banding are effective treatments for bleeding varices with good long-term outcome. Procoagulant state is an infrequent cause of EHPVO in children.

Inflammation: a way to understanding the evolution of portal hypertension

BACKGROUND

Portal hypertension is a clinical syndrome that manifests as ascites, portosystemic encephalopathy and variceal hemorrhage, and these alterations often lead to death.

HYPOTHESIS

Splanchnic and/or systemic responses to portal hypertension could have pathophysiological mechanisms similar to those involved in the post-traumatic inflammatory response.The splanchnic and systemic impairments produced throughout the evolution of experimental prehepatic portal hypertension could be considered to have an inflammatory origin. In portal vein ligated rats, portal hypertensive enteropathy, hepatic steatosis and portal hypertensive encephalopathy show phenotypes during their development that can be considered inflammatory, such as: ischemia-reperfusion (vasodilatory response), infiltration by inflammatory cells (mast cells) and bacteria (intestinal translocation of endotoxins and bacteria) and lastly, angiogenesis. Similar inflammatory phenotypes, worsened by chronic liver disease (with anti-oxidant and anti-enzymatic ability reduction) characterize the evolution of portal hypertension and its complications (hepatorenal syndrome, ascites and esophageal variceal hemorrhage) in humans.

CONCLUSION

Low-grade inflammation, related to prehepatic portal hypertension, switches to high-grade inflammation with the development of severe and life-threatening complications when associated with chronic liver disease.

The mast cell integrates the splanchnic and systemic inflammatory response in portal hypertension

Portal hypertension is a clinical syndrome that is difficult to study in an isolated manner since it is always associated with a greater or lesser degree of liver functional impairment. The aim of this review is to integrate the complications related to chronic liver disease by using both, the array of mast cell functions and mediators, since they possibly are involved in the pathophysiological mechanisms of these complications. The portal vein ligated rat is the experimental model most widely used to study this syndrome and it has been considered that a systemic inflammatory response is produced. This response is mediated among other inflammatory cells by mast cells and it evolves in three linked pathological functional systems. The nervous functional system presents ischemia-reperfusion and edema (oxidative stress) and would be responsible for hyperdynamic circulation; the immune functional system causes tissue infiltration by inflammatory cells, particularly mast cells and bacteria (enzymatic stress) and the endocrine functional system presents endothelial proliferation (antioxidative and antienzymatic stress) and angiogenesis. Mast cells could develop a key role in the expression of these three phenotypes because their mediators have the ability to produce all the aforementioned alterations, both at the splanchnic level (portal hypertensive enteropathy, mesenteric adenitis, liver steatosis) and the systemic level (portal hypertensive encephalopathy). This hypothetical splanchnic and systemic inflammatory response would be aggravated during the progression of the chronic liver disease, since the antioxidant ability of the body decreases. Thus, a critical state is produced, in which the appearance of noxious factors would favor the development of a dedifferentiation process protagonized by the nervous functional system. This system rapidly induces an ischemia-reperfusion phenotype with hydration and salinization of the body (hepatorenal syndrome, ascites) which, in turn would reduce the metabolic needs of the body and facilitate its temporary survival.

Surgical Treatment of Massive Splenomegaly and Severe Hypersplenism Secondary to Extrahepatic Portal Venous Obstruction in Children

PURPOSE

Massive splenomegaly with severe hypersplenism can occur as a late complication of portal hypertension (PH) caused by extrahepatic portal venous obstruction (EHPVO) in children. Severe hypersplenism is often refractory to treatment with endoscopic sclerotherapy (EST) and shunt surgery. We report our experience of managing this disorder surgically.

METHODS

We performed splenectomy and esophagogastric devascularization via laparotomy in 14 children with an average age of 9.7 years. Upper gastrointestinal endoscopy had shown esophageal varices of varying grade, and EST had been done for patients with a history of bleeding. The indications for surgery were pain and discomfort caused by a large spleen greater than 15 cm below the costal margin, and intractable symptomatic hypersplenism with a total leukocyte count <2500/mm3 and a platelet count <50,000/mm3, or both.

RESULTS

Postoperative recovery was uneventful and the leukocyte and platelet counts reverted to normal. After follow-up for 1-5 years, all 14 children were asymptomatic, with improved growth and nutrition and no reported episodes of gastrointestinal bleeding, sepsis, or encephalopathy.

CONCLUSION

Splenectomy with devascularization is effective for children with massive splenomegaly and severe hypersplenism secondary to EHPVO.