meso-Rex Bypass Research Articles

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.

MR angiography and 2-D phase-contrast imaging for evaluation of meso-rex bypass function.

The meso-Rex bypass restores blood flow to the liver in patients with extrahepatic portal vein thrombosis. Stenosis occurs in some cases, causing the reappearance of portal hypertension. Complications such as thrombocytopenia present on a spectrum and there are currently no guidelines regarding a threshold for endovascular intervention. While Doppler ultrasound (US) is common for routine evaluation, magnetic resonance (MR) angiography with two-dimensional phase-contrast MRI (2-D PC-MRI) may improve the assessment of meso-Rex bypass function. To determine the feasibility and utility of MR angiography with 2-D PC-MRI in evaluating children with meso-Rex bypass and to correlate meso-Rex bypass blood flow to markers of portal hypertension. MR angiography and 2-D PC-MRI in meso-Rex bypass patients were retrospectively analyzed. Minimum bypass diameter was measured on MR angiography and used to calculate cross-sectional area. Meso-Rex bypass blood flow was measured using 2-D PC-MRI and divided by ascending aortic flow to quantify bypass flow relative to systemic circulation. Platelet and white blood cell counts were recorded. Correlation was performed between minimum bypass area, blood flow and clinical data. Twenty-five children (median age: 9.5years) with meso-Rex bypass underwent MR angiography and 2-D PC-MRI. The majority of patients were referred to imaging given clinical concern for complications. Eighteen of the 25 patients demonstrated >50% narrowing of the bypass cross-sectional area. The mean platelet count in 19 patients was 127K/μL. There was a significant correlation between minimum cross-sectional bypass area and bypass flow (rho=0.469, P=0.018) and between bypass flow and platelet counts (r=0.525, P=0.021). Two-dimensional PC-MRI can quantify meso-Rex bypass blood flow relative to total systemic flow. In a cohort of 25 children, bypass flow correlated to minimum bypass area and platelet count. Two-dimensional PC-MRI may be valuable alongside MR angiography to assess bypass integrity.

Management of Portal Hypertension in the Pediatric Population: A Primer for the Interventional Radiologist.

Interventional radiology's role in the management of portal hypertension in the pediatric population differs from the management of adult portal hypertension. In the pediatric population, portal hypertension is frequently secondary to thrombosis and cavernous transformation of the extrahepatic portion of the portal vein. Transjugular intrahepatic portosystemic shunt can be utilized to manage portal hypertension in children with intrinsic liver disease that results in cirrhosis and portal hypertension, and is often used as a bridge to transplant. While technically feasible in extrahepatic portal vein occlusion, the sequelae of portosystemic shunting are less desirable in a child. The Meso-Rex bypass procedure, which represents the mainstay of management for pediatric portal hypertension, provides surgical relief of extrahepatic portal vein obstruction and restores mesenteric venous blood flow to the liver. This article aims to review management of portal hypertension in children as it pertains to the interventional radiologist, including preoperative assessment, postoperative evaluation, and the management of complications of the Meso-Rex bypass.

Hepatic Histology and Morphometric Measurements in Idiopathic Extrahepatic Portal Vein Thrombosis in Children, Correlated to Clinical Outcome of Meso-Rex Bypass.

The aim of this study was to correlate clinical, histologic, and morphometric features of the liver in children with extrahepatic portal vein thrombosis (EHPVT), with surgical outcome after Meso-Rex bypass (MRB). Idiopathic EHPVT, a significant cause of portal hypertension, is surgically corrected by MRB. Correlation of histologic and morphometric features of the liver with outcome has not been reported in children. We retrospectively reviewed clinical and intraoperative data of 45 children with idiopathic EHPVT. Liver samples were obtained at the time of MRB. Morphometric measurements of portal tract structures were performed and correlated with surgical outcome. Median follow-up was 3.65 years after surgery (range 1.5 to 10 years). Thirty-seven (82.2%) children had successful MRB. There was no association between age, sex, and suture material with surgical outcome. Average patient age was higher in patients with postoperative complications (P = NS). Portal fibrosis, bridging, parenchymal nodules, portal inflammation, hepatocellular swelling, steatosis, dilatation of portal lymphatics, and periductal fibrosis did not show a significant difference between the 2 groups. Portal vein and bile duct area index were significantly smaller in the unsuccessful group (P = 0.004 and 0.003, respectively). A portal vein area index <0.08 had a lower chance of successful surgical outcome. Hepatic artery area index was not significantly different. Measured intraoperative portal blood inflow was the only significant clinical factor affecting surgical outcome (P = 0.0003). Low portal vein area index and intraoperative portal blood inflow may be negative prognostic factors for MRB outcome in children with idiopathic EHPVT. Average patient age was higher, although not statistically significant, in patients with postoperative complications.

Transsplenic splenoportography and portal venous interventions in pediatric patients.

Data regarding transsplenic portal venous access for diagnostic imaging and endovascular intervention in children are limited, possibly due to concerns regarding high bleeding risks and resultant underutilization. To investigate the safety and utility of transsplenic splenoportography and portal venous interventions in children. A retrospective review was performed of all pediatric patients undergoing percutaneous transsplenic portal venous access and intervention at two large tertiary pediatric institutions between January 2012 and April 2017 was performed. Parameters assessed included procedural indications, procedural and relevant prior imaging, technical details of the procedures, laboratory values and clinical follow-up. Transsplenic portal venous access was achieved in all patients. Diagnostic transsplenic splenoportography was performed in 22 patients and was 100% successful at providing the desired anatomical and functional information. Four transsplenic portal venous interventions were performed with 100% success: meso-Rex shunt angioplasty, snare targeted transjugular intrahepatic portosystemic shunt (TIPS) creation through cavernous transformation, pharmacomechanical thrombectomy for acute thrombosis, and transplant portal vein angioplasty. Intraperitoneal bleeding occurred in 2/26 (7.7%) and one case required transfusion (3.8%). No cases of hemorrhage were observed when transsplenic access size was 4 Fr or smaller. Transsplenic splenoportography in children is safe and effective when noninvasive imaging methods have yielded incomplete information. Additionally, a transsplenic approach has advantages for complex portal interventions. Bleeding risks are proportional to tract access size and may be mitigated by tract embolization.

Idiopathic portal hypertension and extrahepatic portal venous obstruction.

Idiopathic portal hypertension (IPH) and extrahepatic portal venous obstruction (EHPVO) are non-cirrhotic vascular causes of portal hypertension (PHT). Variceal bleed and splenomegaly are the commonest presentations. The present review is intended to provide the existing literature on etiopathogenesis, clinical profile, diagnosis, natural history and management of IPH and EHPVO. IPH and EHPVO are both characterized by normal hepatic venous pressure gradient, moderate to massive splenomegaly with preserved liver synthetic functions. While the level of block in IPH is presinusoidal, in EHPVO it is at prehepatic level. Infections, autoimmunity, drugs, immunodeficiency and prothrombotic states are possible etiological agents in IPH. Contrastingly in EHPVO, prothrombotic disorders and local factors around the portal vein are the incriminating factors. Diagnosis is often clinical, supported by simple radiological tools. Natural history is defined by episodes of variceal bleed and symptoms related to enlarged spleen. Growth failure, portal biliopathy and minimal hepatic encephalopathy are additional concerns in EHPVO. Long-term survival is reasonably good with endoscopic surveillance; however, parenchymal extinction leading to decompensation is seen in a minority of patients in both the disorders. Surgical shunts revert the complications secondary to PHT. Meso-Rex shunt has become the standard surgery in children with EHPVO. This review gives a detailed summary of these two vascular conditions of liver-IPH and EHPVO. Further research is needed to understand the pathogenesis and natural history of these disorders.

Metabolic profile of children with extrahepatic portal vein obstruction undergoing meso-Rex bypass

BackgroundExtrahepatic portal vein obstruction (EHPVO) in children is often associated with growth restriction, which improves after the restoration of portal venous flow with a meso-Rex bypass, but the physiologic mechanism is unknown. The purpose of this study was to investigate the mechanism of growth delay in children with EHPVO by detailing the metabolic and nutritional profile before and after meso-Rex bypass. MethodsTwenty consecutive children with EHPVO were prospectively studied before and 1 year after meso-Rex bypass. Caloric balance was determined by investigating caloric intake via a calorie count, total energy expenditure via a doubly labeled water isotope assay and stool caloric loss by bomb calorimetry. Laboratory markers of nutrition and growth hormone resistance were tested. ResultsFifteen of the 20 children underwent successful meso-Rex bypass at a median age of 4.3 years. Prealbumin level was abnormally low (14.6 ± 3.0 mg/dL) at surgery but improved (17.0 ± 4.3 mg/dL) 1 year later (P = 0.026). Mean insulin-like growth factor 1 (IGF-1) level at baseline was 1.57 standard deviations below normal. IGF-1 levels increased from 88.3 ± 38.9 to 117.3 ± 54.5 ng/mL in the year after surgery (P = 0.047). Caloric intake divided by basal metabolic rate (1.90 ± 0.61), total energy expenditure (97.2 ± 15.0% of expected), and stool caloric losses (3.7 ± 1.8% of caloric intake) were all normal at baseline. ConclusionsChildren with EHPVO suffer from malnutrition and growth hormone resistance, which may explain their well-established finding of growth restriction. Prealbumin and IGF-1 levels improve after a successful meso-Rex bypass.

An Unusual Cause of Hematemesis: Esophageal Varices in a Child

Portal vein thrombosis (PVT) is characterized by the complete or partial obstruction of the portal vein, due to the presence of a thrombus. This condition eventually results in non-cirrhotic portal hypertension (PHT) and is the leading cause of pediatric PHT and gastrointestinal bleeding. Risk factors for PVT in pediatric patients include those with a history of umbilical vein catheterization, neonatal sepsis, abdominal infection, cardiovascular malformation, coagulation disorder, or previous abdominal surgery. We present a unique case of bleeding esophageal varices due to non-cirrhotic PHT in a child. A 15-year-old male presented with a 1-day history of hematemesis. On presentation, the patient was tachycardic and hypotensive. The patient's initial hemoglobin was 8.0g/dL, and was resuscitated with packed red blood cells and intra-venous fluids. An esophagogastroduodenoscopy was performed which revealed large esophageal varices with nipple sign in the distal esophagus and gastric varices throughout the fundus (Figure 1). The patient underwent variceal band ligation, however continued to have hematemesis. Ultrasound and CT scan of the abdomen showed presence of a chronic portal vein occlusion with significant cavernous transformation (Figure 2). Surgery was consulted and the patient underwent exploratory laparotomy with failed attempt of Meso-Rex bypass and subsequent creation of a splenorenal shunt. Liver biopsy did not show any evidence of cirrhosis. The patient was discharged on post-operative day five after tolerating diet and resolution of symptoms. Prior to discharge, a complete hypercoagulability work-up was performed and the patient was found to have elevated anti-b2 glycoprotein levels, consistent with anti-phospholipid syndrome and the likely cause of this patient's portal vein thrombosis. Patients with chronic PVT may remain asymptomatic for many years, with variceal bleeding usually being the first manifestation of PVT in non-cirrhotic patients, which was the case in our patient. When there is a high clinical suspicion for PVT, ultrasonography (US) of the abdomen is the first line imaging modality. In children, creation of a Meso-Rex bypass, a vascular graft between the superior mesenteric vein and the Rex recessus (left portal vein system), helps improve clinical outcomes. Proper diagnosis of patient's' underlying condition predisposing to PVT is important in preventing further recurrence.Figure: Esophagogastroduodenoscopy showing large esophageal varices with nipple sign (A) and large gastric varices throughout the fundus (B).Figure: Ultrasound of the liver showing main portal vein thrombosis (A), and the use of doppler showing cavernous transformation of the portal vein (B), while CT scan of the abdomen and pelvis (venous phase) showing lack of blood flow through portal vein, findings consistent with presence of portal vein thrombosis, and extensive cavernous transformation (C).

Extrahepatic Portal Venous Obstruction: What Should be the Mainstay of Treatment?

The two cornerstones of management for Extrahepatic portal vein obstruction (EHPVO) are endotherapy and surgery [Porto-systemic shunts (PSS)/Mesorex bypass (MRB)]. Endotherapy is the mainstay of treatment for acute variceal bleed control and has also been used extensively for secondary prophylaxis till variceal eradication is achieved. However, long-term follow-up beyond endoscopic eradication of esophageal varices (EEEV) indicates that there are numerous delayed bleed and non bleed sequelae of EHPVO, which merit surgery as a definitive procedure to decompress the hypertensive portal venous system. While endotherapy obliterates natural porto-systemic collaterals in the gastroesophageal region, persistently raised portal pressures manifest as an increase in secondary isolated gastric varices, ectopic varices, portal hypertensive vasculopathy, issues related to massive splenomegaly, portal biliopathy, growth retardation and hence impaired quality of life (QOL). An ideal management strategy should address both bleed and non-bleed consequences of EHPVO and translate into a near normal QOL. Further, MRB has opened up new dimensions to the management philosophy of EHPVO. This review article critically evaluates the role of surgery and endotherapy based on available literature and authors' own experience.Surgery and endotherapy are complementary. However, with increasing duration of follow-up post EEEV, it is evident that there is resurgence in the role of surgery (PSS/MRB) as a single one time definitive procedure for alleviating all bleed and delayed non bleed sequelae of EHPVO.Surgery for EHPVO (PSS/MRB) should not be allowed to become a dying art and future generations of surgeons should continue to receive training in this specialized area of surgery.

Splenectomy for Severe Intestinal Bleeding Caused by Portal Hypertensive Enteropathy After Pediatric Living-Donor Liver Transplantation: A Report of Three Cases

BackgroundThe incidence of portal vein thrombosis after pediatric living-donor liver transplantation (LDLT) is reported to be higher than that after deceased-donor or adult liver transplantation. Portal vein thrombosis can cause portal hypertension and related complications, including portal hypertensive gastropathy or portal hypertensive enteropathy (PHE). PHE, in particular, can lead to severe intestinal bleeding, which is extremely difficult to treat. However, the pathogenesis of and appropriate treatment for PHE are not clearly defined, especially after pediatric LDLT. MethodsHerein, we report three cases of refractory intestinal bleeding caused by PHE after pediatric LDLT, which were treated with splenectomy. ResultsThe time between LDLT and splenectomy was 43, 92, and 161 months, respectively. All 3 patients were discharged from the hospital without any peri-operative complications and were doing well, with no adverse effects at 174, 81, and 12 months after splenectomy, respectively. Although shunt surgeries, including the use of a meso-Rex shunt, are reported to be a useful option when the portal vein is completely occluded, adhesiotomy around the liver graft would be required, which could damage the hepatopetal collateral vessels that maintain portal vein flow to the graft. Therefore, shunt surgeries, which can lead to re-transplantation, are considered to be highly risky as a first-line treatment option, particularly considering the limited accessibility to deceased donor organs in our country. ConclusionsOur data demonstrate that simple splenectomy, although considered a palliative treatment, can be a safe and effective method to control severe intestinal bleeding caused by PHE after pediatric LDLT.

Evolution of portal hypertension surgery in children

Introduction: Surgical portosystemic shunts (PSS) and Meso-Rex bypass (MRB) are both proven effective at treatment for portal hypertension in children, since the development of the MRB for extra hepatic portal vein obstruction (EHPVO) we have witnessed an evolution in the approach to this problem. The aim of this study is to evaluate the indication, patency and survival after these procedures. Methods: A retrospective analysis of children undergoing surgery for portal hypertension between 2008 to 2015. Results: 19 surgical shunts in 17 children. 8 female and 9 male with a mean age at surgery of 9y (1–18). Diagnosis were: EHPVO (10), congenital hepatic fibrosis (2), biliary atresia (1), cryptogenetic cirrhosis (3), portal vein stenosis after LDLT (1), thrombosis of previous MRB (2). We attempted 9 MRB and performed 7. 5 patients had a distal splenorenal shunt, 4 Proximal splenorenal, 1 splenocaval, 1 mesorenal, and 1 IMV to left renal vein. Three were occluded before the 6th months: 2 cases MRB and 1DSRS one month later on child transplanted 4 months later. The overall shunt occlusion is 26%. At last follow up all the patients are alive. Conclusions: We have seen an evolution in the therapy of portal hypertension in children, we as others believe that restoring flow by MRB should be the first line of treatment. MRB is not always functional due to intrahepatic anatomy or liver disease. PSS (selective when possible) are an excellent alternative for these cases and for children with chronic liver disease.

Primary prophylaxis of variceal bleeding in children and the role of MesoRex Bypass: Summary of the Baveno VI Pediatric Satellite Symposium.

Approaches to the management of portal hypertension and variceal hemorrhage in pediatrics remain controversial, in large part because they are not well informed by rigorous clinical studies. Fundamental biological and clinical differences preclude automatic application of approaches used for adults to children. On April 11-12, 2015, experts in the field convened at the first Baveno Pediatric Satellite Meeting to discuss and explore current available evidence regarding indications for MesoRex bypass (MRB) in extrahepatic portal vein obstruction and the role of primary prophylaxis of variceal hemorrhage in children. Consensus was reached regarding MRB. The vast majority of children with extrahepatic portal vein obstruction will experience complications that can be prevented by successful MRB surgery. Therefore, children with extrahepatic portal vein obstruction should be offered MRB for primary and secondary prophylaxis of variceal bleeding and other complications, if appropriate surgical expertise is available, if preoperative and intraoperative evaluation demonstrates favorable anatomy, and if appropriate multidisciplinary care is available for postoperative evaluation and management of shunt thrombosis or stenosis. In contrast, consensus was not achieved regarding primary prophylaxis of varices. Although variceal hemorrhage is a concerning complication of portal hypertension in children, the first bleed appears to be only rarely fatal and the associated morbidity has not been well characterized. There are few pediatric data to indicate the efficacy and safety of pharmacologic or endoscopic therapies as primary prophylaxis or that prevention of a sentinel variceal bleed will ultimately improve survival; therefore, no recommendation for primary prophylaxis with endoscopic variceal ligation, sclerotherapy, or nonspecific beta-blockade in children was proposed.

Variant meso-Rex bypass with transposition of abdominal autogenous vein for the management of idiopathic extrahepatic portal vein obstruction: a retrospective observational study.

BackgroundThe aim of this study was to evaluate whether variant meso-Rex bypass with transposition of abdominal autogenous vein can be used as an alternative treatment modality for selected patients with symptomatic extrahepatic portal vein obstruction.MethodsThis was a retrospective review of six consecutive patients who received this alternative procedure for the treatment of symptomatic portal hypertension secondary to idiopathic extrahepatic portal vein obstruction. Their clinical characteristics, operative procedures and outcomes were analyzed retrospectively.ResultsThe procedure was attempted in six patients, and all had a patent shunt established by intraoperative portography at the end of the procedure; the coronary vein was used in four patients and the inferior mesenteric vein was used in two. During the median period of 23.5 months (range 10–30 months), follow-up was uneventful except one patient; reduced portal hypertension and no new episodes of gastrointestinal bleeding were observed in all patients, with the exception of one patient with shunt stenosis and recurrent varix bleeding who had to undergo endovascular treatment to restore portal vein blood flow. Technical and clinical success was achieved in all patients.ConclusionsThis procedure could be used safely and effectively to treat selected patients with portal hypertension secondary to extrahepatic portal vein obstruction.

Prehepatic portal hypertension with aneurysm of the portal vein: Unusual but treatable malformative pattern

IntroductionPortal vein aneurysms (PVAs) are usually located at the vein trunk or at its bifurcation, rarely intra-hepatic, or at the umbilical portion. Etiology remains unclear. MethodsThree children with PVA were identified over a 5-year period. PVA anatomy was assessed by Doppler Ultrasound, Angio CT/MRI, and trans-jugular retrograde portography. ResultsThree children with intrahepatic PVA (including the umbilical portion) were identified during assessment for pre-hepatic portal hypertension: all had splenomegaly and hypersplenism. One presented with massive variceal bleeding. In two cases, a portal vein cavernoma was found, and in the third a severe stricture at the portal bifurcation was observed. Restoration of portal venous flow was achieved by a meso-Rex bypass in two cases and transposing the PV into the Rex in one. High hepatopetal portal flow was restored immediately, with follow-up confirming long-term patency and resolution of signs of portal hypertension with time. ConclusionsThese original observations suggest a common initial malformative pattern consisting of a portal venous stricture/web causing a post-stenotic aneurysmal dilatation of the intrahepatic portal branches complicated by thrombosis and cavernomatous transformation of the portal vein trunk. Importantly, the Meso-Rex bypass allows restoring a normal portal flow and cures the portal hypertension.

Partial splenectomy and use of splenic vein as an autograft for meso-Rex bypass: a clinical observational study.

BackgroundMeso-Rex bypass (MRB) surgery is being increasingly used to treat chronic prehepatic portal hypertension secondary to extrahepatic portal vein thrombosis (EPVT) and cavernous transformation (EPVCT) in children. Rather than using the internal jugular vein (IJV, the traditional venous graft), we used an autogenous splenic vein segment graft for MRB.Material/MethodsWe examined 25 children with extrahepatic portal hypertension and a history of recurrent upper gastrointestinal (GI) variceal bleeding despite previous endoscopic sclerotherapy. All patients had melena, splenomegaly, hypersplenism, or some combination thereof. Left portal vein (LPV) patency was verified in 22 patients using intraoperative direct portography through the umbilical vein. Partial splenectomy was performed to enable the harvest of the splenic vein trunk, which was anastomosed between the superior mesenteric vein (SMV) and the left portal vein (LPV). All patients were followed for 12–48 months (mean=25.6 months) and no patients were lost to follow-up.ResultsPreoperative Doppler ultrasound (US) imaging indicated that 18/25 patients had adequate intrahepatic portal veins for shunting, with no blood flow in the LPVs of 7 patients. LPV patency in 22/25 patients was verified using intraoperative direct portography, with successful MRB. Shunting was converted into a portosystemic shunt in the remaining 3/25 patients with thrombosed LPVs. A Doppler US evaluation of the vein conduit revealed excellent postoperative flow. The patients’ mean hemoglobin, platelet, and white blood cell counts increased significantly, and in all cases the endoscopic status obviously improved after shunting. Occlusion or narrowing occurred in 2/22 patients after discharge. At 12 months (for 1 patient) and 24 months (for 1 patient), the shunt was converted into a portosystemic shunt. The cumulative graft patency rate was 91% (20/22).ConclusionsPartial splenectomy and splenic vein autografting in MRB surgery can successfully resolve prehepatic portal hypertension and hypersplenism in children.

Management of late‐onset portal vein complications in pediatric living‐donor liver transplantation

The purpose of this study was to evaluate retrospectively the results of PTA for late-onset PV complications after pediatric LDLT and to assess whether a meso-Rex shunt is a viable option for treating restenosis of the PV after PTA in selected cases. Seventy-five children who underwent adult-to-child LDLT were included in this study, and there were six late-onset PV complications (8.0%). The initial therapeutic approach was PTA, with or without stent: PTA with balloon dilation for three children, PTA with stent placement for one child, and failure to cannulate the occluded PV for two children. A meso-Rex shunt was performed in the two children after failed PTA: One suffered complete obstruction of the main PV, and the other, restenosis with total thrombosis after PTA with stent. The PTA was a technical and clinical success in four with PV stenosis of the six patients (66.7%), and successful application of a meso-Rex shunt in the other two children resulted in restoration of PV flow. In conclusion, PTA is a safe and effective procedure for treating late-onset PV stenosis after pediatric LDLT. However, in growing pediatric recipients with restenosis of the PV after PTA or chronic PV thrombosis, a meso-Rex shunt may be a better choice for late-onset PV complications.

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

BackgroundChildren 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. MethodsAll 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. ResultsEighty-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. ConclusionsWedged 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.

Meso-Rex Bypass—A Procedure to Cure Prehepatic Portal Hypertension: The Insight and the Inside

Meso-Rex Bypass—A Procedure to Cure Prehepatic Portal Hypertension: The Insight and the Inside

Meso-Rex bypass for extrahepatic portal vein obstruction in children

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. 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. 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 < 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). 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.

Treatment of portal hypertension from portal vein cavernoma with the meso-Rex bypass

Treatment of portal hypertension from portal vein cavernoma with the meso-Rex bypass