Advantages of the meso-Rex bypass compared with portosystemic shunts in the management of extrahepatic portal vein obstruction in children. J Am Coll Surg. 2013;216:83-89. [PMID: 23177370 DOI: 10.1016/j.jamcollsurg.2012.09.013]

Percutaneous recanalization of non-cirrhotic extrahepatic portal vein obstruction in children: technical considerations in a preliminary cohort

OBJECTIVES

Portal hypertension resulting from non-cirrhotic extrahepatic portal vein obstruction (EHPVO) in children has been primarily managed with the Meso-Rex bypass, but only a few patients have a viable Rex recessus, required by surgery. This study reports a preliminary series of patients who underwent interventional radiology attempts at portal vein recanalization (PVR), with a focus on technical aspects and safety.

METHODS

A retrospective review of consecutive patients with severe portal hypertension due to non-cirrhotic EHPVO at a single institution from 2022, who underwent percutaneous attempts at PVR, was performed. Technical and clinical data including fluoroscopy time, radiation exposure, technical and clinical success, complications and follow-up were recorded.

RESULTS

Eleven patients (6 males and 5 females; median age 7 years, range 1-14) underwent 15 percutaneous transhepatic (n = 1), transplenic (n = 11), or simultaneous transhepatic/transplenic (n = 3) procedures. Rex recessus was patent in 4/11 (36%). Fluoroscopy resulted in a high median total dose area product (DAP) of 123 Gycm2 (range 17-788 Gycm2) per procedure. PVR was achieved in 5/11 patients (45%), 3/5 with obliterated Rex recessus. Two adverse events of grade 2 and grade 3 occurred without sequelae. After angioplasty, 4/5 patients required stenting to obtain sustained patency, as demonstrated by colour-Doppler ultrasound in all PVR after a median follow-up of 6 months (range 6-14).

CONCLUSION

Our preliminary experience suggests that 45% of children with non-cirrhotic EHPVO can restore portal flow even with obliterated Rex recessus. In non-cirrhotic EHPVO, PVR may be an option, if a Meso-Rex bypass is not feasible, although the radiation exposure deserves attention.

CLINICAL RELEVANCE STATEMENT

Innovative percutaneous procedures may have the potential to be an alternative option to the traditional surgical approach in the management of non-cirrhotic EHPVO and its complications in children not eligible for Meso-Rex bypass surgery.

KEY POINTS

Non-cirrhotic portal hypertension in children has been traditionally managed by surgery with Meso-Rex bypass creation. Percutaneous PVR may restore the patency of the native portal system even when the Rex recessus is obliterated and surgery has been excluded. Interventional radiological techniques may offer a minimally invasive solution in complex cases of EHPVO in children when Meso-Rex bypass is not feasible.

Effectiveness of Preoperative Intrahepatic Portal Venous Classification System in Guiding Preoperative Surgical Decisions and Predicting Hypotensive Effects After Meso-rex Bypass for Children With EHPVO

BACKGROUND

The categorization of intrahepatic portal venous system (IHPS) patterns using wedged hepatic venous portography (WHVP) has proven to be an effective tool in the preoperative evaluation of Rex recessus and in identifying pediatric patients with extrahepatic portal vein obstruction (EHPVO) who are suitable for meso-Rex bypass (MRB). Despite this classification system being proposed a decade ago, its clinical application remains underutilized.

METHODS

A single-center retrospective study of 182 children with EHPVO was conducted between October 2014 and July 2023 when MRB was attempted. Data on demographics, etiology, imaging examinations, procedures, and follow-up were collected for 161 patients included. Two interventional radiologists used deVille's method to classify patients into types A to E based on WHVP imaging, with interobserver agreement analyzed. Associations between IHPS patterns and surgical outcomes following MRB were investigated.

RESULTS

Two radiologists had a high level of agreement on identifying IHPS patterns and suitable patients for MRB. Of the 161 cases, 130 were type A, 10 were type B, 5 were type C, 7 were type D, and 9 were type E. One hundred and forty-five patients with types A, B and C underwent successful MRB, showing feasibility for 90% of patients. Children categorized as types A and B experienced more significant benefits than type C, including intraoperatively decreased portal vein pressure, esophageal/gastric varices relief, decreased portal venous collaterals and a lower rate of bypass occlusion after one year. The surgical outcomes of patients with types A and B were not influenced by the diameter of the Rex recessus as suggested by WHVP.

CONCLUSIONS

The majority of pediatric patients with EHPVO in mainland China have opportunities to receive successful MRB. There are potential differences in the etiology of Chinese and Western patients. The IHPS classification system aids in guiding preoperative surgical decisions and predicting hypotensive effects after MRB. Type C patients should be carefully chosen for MRB.

The effectiveness of alternative vessel grafts for meso-rex bypass in the treatment of extrahepatic portal vein obstruction in children

PURPOSE

This study aims to evaluate the effectiveness of alternative autologous vessel grafts in creating a Meso-Rex bypass (MRB) compared to the distal splenorenal shunt (DSRS) in resolving symptoms of portal hypertension in children.

METHODS

All children with EHPVO evaluated for surgery at Siriraj Hospital from January 2011 to December 2023 were reviewed. Alternative autologous vessel grafts were used in all cases where MRB was feasible. DSRS was performed in patients for whom MRB was not possible. Baseline characteristics and outcomes were compared between the two groups.

RESULTS

Eight children underwent successful MRB with alternative autologous vessel grafts, while six required DSRS. Children in the modified MRB group were significantly younger, with upper gastrointestinal bleeding the most common presenting symptom. In contrast, children in the DSRS group had significantly lower preoperative ammonia levels and platelet counts, with hypersplenism being the most common presenting symptom. All patients experienced complete relief of variceal bleeding and hypersplenism post-surgery. Complicated shunt thrombosis occurred after MRB using the gastric coronary vein graft. A significant decrease in ammonia levels was observed after MRB, whereas levels increased after DSRS.

CONCLUSION

Alternative autologous vessel grafts are effective for constructing the MRB to resolve portal hypertension compared to DSRS.

Intrahepatic portal venous systems in adult patients with cavernous transformation of portal vein: Imaging features and a new classification

BACKGROUND

Cavernous transformation of the portal vein (CTPV) due to portal vein obstruction is a rare vascular anomaly defined as the formation of multiple collateral vessels in the hepatic hilum. This study aimed to investigate the imaging features of intrahepatic portal vein in adult patients with CTPV and establish the relationship between the manifestations of intrahepatic portal vein and the progression of CTPV.

METHODS

We retrospectively analyzed 14 CTPV patients in Beijing Tsinghua Changgung Hospital. All patients underwent both direct portal venography (DPV) and computed tomography angiography (CTA) to reveal the manifestations of the portal venous system. The vessels measured included the left portal vein (LPV), right portal vein (RPV), main portal vein (MPV) and the portal vein bifurcation (PVB).

RESULTS

Nine males and 5 females, with a median age of 40.5 years, were included in the study. No significant difference was found in the diameters of the LPV or RPV measured by DPV and CTA. The visualization in terms of LPV, RPV and PVB measured by DPV was higher than that by CTA. There was a significant association between LPV/RPV and PVB/MPV in term of visibility revealed with DPV (P = 0.01), while this association was not observed with CTA. According to the imaging features of the portal vein measured by DPV, CTPV was classified into three categories to facilitate the diagnosis and treatment.

CONCLUSIONS

DPV was more accurate than CTA for revealing the course of the intrahepatic portal vein in patients with CTPV. The classification of CTPV, that originated from the imaging features of the portal vein revealed by DPV, may provide a new perspective for the diagnosis and treatment of CTPV.

A History of Umbilical Vein Catheterization Does Not Preclude Children from a Successful Meso-Rex Bypass

INTRODUCTION

 Umbilical vein catheterization (UVC) can cause portal venous thrombosis, leading to the development of extrahepatic portal venous obstruction (EHPVO) and portal hypertension (PHT). The feasibility of the Meso-Rex bypass (MRB) for the treatment of EHPVO in patients with a history of UVC has been questioned. We compared the feasibility of performing an MRB in patients with or without a history of previous UVC.

METHODS

 A retrospective review of patients with EHPVO and known UVC status explored for a possible MRB at our institution was performed (1997-2022). Patients were categorized in two groups: with (UVC(+)) or without (UVC(-)) a history of UVC for comparison. A p-value less than 0.05 was considered significant.

RESULTS

 One hundred and eighty-seven patients were included (n = 57 in UVC(+); n = 130 in UVC(-)). Patients in the UVC group were significantly younger at surgery and the incidence of prematurity was higher. Other risk factors for the development of EHPVO were similar between the groups, but only history of UVC could predict the ability to receive MRB (odds ratio [OR]: 7.4 [3.5-15.4]; p < 0.001). The success rate of MRB was significantly higher in patients with no history of UVC (28/57 [49.1%] in UVC(+) vs. 114/130 [87.7%] in UVC(-); p < 0.001). However, MRB patency at discharge (25/28 [89.3%] in UVC(+) vs. 106/114 [94.7%] in UVC(-); p = 0.3) was equally high in both groups.

CONCLUSION

 Our results indicate that a history of UVC is not a contraindication to MRB. Half of the patients were able to successfully receive an MRB. Patients with symptomatic PHT from EHPVO should not be excluded from consideration for MRB based on UVC history.

Recanalization of portal vein thrombosis after pediatric liver transplantation: Efficacy and safety of the transsplenic access

BACKGROUND

Endovascular management of portal vein thrombosis (PVT) is challenging. Transsplenic access (TSA) is growing as an access option to the portal system but with higher rates of bleeding complications. The aim of this article is to evaluate the efficacy and safety of transsplenic portal vein recanalization (PVR) using a metallic stent after pediatric liver transplantation.

MATERIALS AND METHODS

This is a retrospective review of 15 patients with chronic PVT who underwent PVR via TSA between February 2016 and December 2020. Two children who had undergone catheterization of a mesenteric vein tributary by minilaparotomy were excluded from the patency analysis but included in the splenic access analysis. The technical and clinical success of PVR and complications related to the procedure via TSA were evaluated.

RESULTS

Thirteen children with PVT were treated primarily using the TSA. The mean age was 4.1 years (range, 1.5-13.7 years), and the most common clinical presentation was hypersplenism (60%). Technically successful PVR was performed in 11/13 (84.6%) children, and clinical success was achieved in 9/11 (81.8%) children. No major complications were observed, and one child presented moderate pain in the TSA (from a total of 17 TSA). The median follow-up was 48.2 months. The median primary patency was 9.9 months. Primary patency in the first 4 years was 75%, and primary assisted patency was 100% in the follow-up period.

CONCLUSIONS

Transsplenic PVR is a safe and effective method for the treatment of PVT after pediatric liver transplantation.

Location and extent of cavernous transformation of the portal vein dictates different visceral side revascularization in Meso-Rex bypass

BACKGROUND

As an emerging standard of care for portal vein cavernous transformation (PVCT), Meso-Rex bypass (MRB) has been complicated and variated. The study aim was to propose a new classification of PVCT to guide MRB operations.

METHODS

Demographic data, the extent of extrahepatic PVCT, surgical methods for visceral side revascularization, intraoperative blood loss, operating time, changes in visceral venous pressure before and after MRB, postoperative complications and the condition of bypass vessels after MRB were extracted retrospectively from the medical records of 19 patients.

RESULTS

The median age of the patients (13 males and 6 females) was 32.5 years, while two patients were underage. Causes of PVCT can be summarized as follows: thrombophilia such as dysfunction of antithrombin III or proteins C; secondary to abdominal surgeries; secondary to abdominal infection or traumatic intestinal obstruction, and unknown causes. Intraoperatively, the median operation time was 9.5 h (7-13 h), and the intraoperative blood loss was 300 mL (100-1,600 mL). Ten cases used autologous blood vessels while 10 used allogeneic blood vessels. The vascular anastomosis was divided into the following types according to the site and approach: Type (T) 1-PV pedicel type, T2-confluence type, T3-major visceral vascular type; and T4-collateral visceral vascular type. Furthermore, the visceral venous pressure before and after MRB dropped significantly from 36 cmH2O (28-44) to 24.5 cmH2O (15-31) (P < 0.01). Postoperatively, one patient had delayed wound healing, two developed biochemical pancreatic fistulae, one experienced lymphatic leakage, the former caused by heat damage of the pancreatic tissues, the latter by cutting lymphatic vessels in the mesentery or removing the local lymph nodes during the process of separating the superior mesenteric vein, and one was re-operated on for an intervening intestinal fistulae. Postoperative enhanced CT scans revealed a significant improvement in abdominal varix in the patients with patent bypass, and at the 1-year postoperative follow-up, enhanced CT scans of six patients showed that the long axis of the spleen was reduced by ≥ 2 cm.

CONCLUSIONS

MRB can effectively reduce visceral venous pressure in patients with PVCT. It is feasible to determine the PVCT type according to the extent of involvement and to choose individualized visceral side revascularization performances.

Ectopic Variceal Bleeding from the Hepaticojejunostomy due to Extrahepatic Portal Vein Occlusion: How to Treat?

Atypical variceal bleeding, which primarily stems from extrahepatic portal vein obstruction (EHPVO), is a severe complication of pancreatic hepatobiliary surgery. This review provides insights into this condition's incidence, diagnosis, and management strategies. The treatment modalities for atypical variceal bleeding resulting from EHPVO range from endoscopic intervention to surgical procedures, including direct variceal ligation and shunt surgery. Here, we discuss the efficacy and potential limitations of each treatment approach. Additionally, we explored the utility and therapeutic advantages of the meso-Rex shunt, a particularly promising surgical technique for mitigating the hemodynamic and metabolic impacts of EHPVO.

Effectiveness of Rex shunt for improving the abnormal portal hemodynamics and portal venous pathology in EHPVO animal model

PURPOSE

To investigate the feasibility of the re-patent EHPVO (r-EHPVO) as an animal model of Rex shunt and the effectiveness of Rex shunt in improving abnormal portal hemodynamics and portal venous pathology of EHPVO.

METHODS

A total of 18 New Zealand white rabbits were randomly divided into three groups: normal control (NC) group, extrahepatic portal venous obstruction (EHPVO) group, and r-EHPVO group. The main portal vein was dissected only in the NC group. The main portal vein was narrowed by a cannula in the EHPVO group. The cannula narrowing the main portal vein was removed to restore the portal blood flow into the liver on day 14 in the r-EHPVO group. The portal pressure, splenic size, blood flow velocity, and diameter of the portal vein were measured on days 14 and 28. The shear stress (SS) and circumferential stress (CS) of the portal vein were calculated. The proximal end of the main portal vein was collected on day 28 for further pathological analysis, and the thickness and area of the intima and media were measured by Image J software. The portal pressure, splenic size, SS, CS, intima and media thickness, the ratio of intimal to medial area (I/M), and the ratio of intimal area to the sum of intimal and medial area (I/I + M) were compared among the three groups. The correlation between SS and intimal thickness and between CS and medial thickness were analyzed.

RESULTS

On day 28, the portal pressure of the EHPVO group was significantly higher than that of the NC and r-EHPVO groups, but no significant difference was detected in the portal pressure between r-EHPVO and NC groups. The length and thickness of the spleen in the EHPVO and r-EHPVO groups were significantly higher than those in the NC group (P < 0.01) but were significantly lower in the r-EHPVO group than those in the EHPVO group (P < 0.05). The SS was significantly lower in the EHPVO group than in NC and r-EHPVO groups (P < 0.05) but was significantly higher in the NC group than in the r-EHPVO group (P = 0.003). The CS was significantly higher in the EHPVO and r-EHPVO groups than that in the NC group (P < 0.05) but was significantly lower in the r-EHPVO group than that in the EHPVO group (P < 0.001). The intimal thickness, I/M, and I/I + M of the EHPVO group were significantly higher than those of the NC and r-EHPVO groups (P < 0.05), but no significant difference was observed between the NC and r-EHPVO groups (P > 0.05). The SS is negatively related to intimal thickness (r =  - 0.799, P < 0.001).

CONCLUSION

The r-EHPVO model is feasible as an animal model of the Rex shunt. The Rex shunt could be beneficial to improving the abnormal portal hemodynamic and portal venous intimal hyperplasia by restoring the portal blood flow into the liver.

Application of transmesenteric vein extrahepatic portosystemic shunt in treatment of symptomatic portal hypertension with cavernous transformation of portal vein

Purpose

To evaluate the feasibility and efficacy of a transmesenteric vein extrahepatic portosystemic shunt (TmEPS) for the treatment of cavernous transformation of the portal vein (CTPV).

Materials and methods

The clinical data of 20 patients with CTPV who underwent TmEPS between December 2020 and January 2022 ​at Henan Provincial People's Hospital were retrospectively collected. The superior mesenteric vein (SMV) trunk was patent or partially occluded in these patients. An extrahepatic portosystemic shunt between the inferior vena cava and the SMV was established using a stent graft through an infraumbilical median longitudinal mini-laparotomy. The technical success, efficacy, and complication rates were evaluated, and the pre- and postoperative SMV pressures were compared. Patients' clinical outcomes and shunt patency were assessed.

Results

TmEPS was successfully performed in 20 patients. The initial puncture success rate of the balloon-assisted puncture technique is 95%. The mean SMV pressure decreased from 29.1 ​± ​2.9 ​mmHg to 15.6 ​± ​3.3 ​mmHg (p ​< ​0.001). All symptoms of portal hypertension resolved. No fatal procedural complications occurred. During the follow-up period, hepatic encephalopathy occurred in two patients. The remaining patients remained asymptomatic. All shunts were patent.

Conclusions

TmEPS is a feasible, safe, and effective treatment option for patients with CTPV.

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.

Optimal Treatment for Patients With Cavernous Transformation of the Portal Vein

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

Superior mesenteric vein to the right testicular vein shunt operation for jejunal varices bleeding associated with extrahepatic portal vein obstruction after pancreaticoduodenectomy: a case report

Background

Causes of extrahepatic portal vein obstruction include abdominal surgeries such as pancreaticoduodenectomy. We improved jejunal variceal bleeding due to extrahepatic portal vein occlusion after pancreaticoduodenectomy, by shunting of the testicular vein.

Case presentation

A 72-year-old man was diagnosed with extrahepatic bile duct cancer and underwent subtotal stomach-preserving pancreaticoduodenectomy 5 years ago. No postoperative complications occurred, adjuvant chemotherapy using gemcitabine hydrochloride was performed, and the patient remained recurrence-free. One year and 6 months post-operation, extrahepatic portal vein stenosis appeared, but no recurrence was noted. However, 4 years and 6 months later, recurrent gastrointestinal bleeding occurred, and the patient was diagnosed with an extrahepatic portal vein obstruction. Double-balloon enteroscopy showed capillary dilatation and varicose veins in the hepaticojejunostomy region, and venous bleeding from collateral blood vessels was diagnosed. A superior mesenteric vein to the right testicular vein shunt operation was performed, following which the gastrointestinal bleeding disappeared, and the anemia improved. Although transient hepatic encephalopathy occurred, conservative treatment relieved it. Double-balloon enteroscopy confirmed the disappearance of abnormal blood vessels.

Conclusions

A portosystemic shunt operation using the right testicular vein effectively relieved refractory variceal bleeding around the hepaticojejunostomy site in the jejunum due to an extrahepatic portal vein obstruction after pancreaticoduodenectomy.

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.

Functional side-to-side splenorenal shunts to treat extrahepatic portal vein thrombosis in children

BACKGROUND

Surgical shunts are commonly used to manage complications resulting from extrahepatic portal vein thrombosis (EHPVT) in children. We describe a single-center experience utilizing a functional Side-to-Side Splenorenal Shunt (fSRS), created using either an enlarged inferior mesenteric vein (IMV) or left adrenal vein (LAV).

METHODS

Pediatric patients with isolated EHPVT who were poor candidates for a Rex shunt and who underwent a fSRS procedure at our institution between 2003 and 2020 were reviewed. The pre/post shunt portosystemic gradient change, rates of early and late complications, postoperative shunt patency, and mortality were evaluated.

RESULTS

Twelve EHPVT patients (mean age of 6.1 years) underwent a fSRS procedure. The mean portosystemic gradient change for the cohort was -11.7 mmHg (±4.9). There were no cases of recurrent variceal bleeding or episodes of shunt thrombosis reported after fSRS procedures.

CONCLUSIONS

Surgical shunts continue to be an important adjunct in the treatment of complications related to EHPVT. The functional Side-to-Side Splenorenal Shunt is a safe alternative that is easy to perform, involves minimal dissection and requires only a single anastomosis.

Technical Aspects and Considerations of Meso-Rex Bypass Following Liver Transplantation With Left Lateral Segment Grafts: Case Report and Review of the Literature

In pediatric patients with extrahepatic portal vein obstruction and complications of portal hypertension, but with normal liver function, a meso-Rex bypass (MRB) connecting the superior mesenteric vein to the intrahepatic left portal is the favored surgical management. Pediatric patients with a history of a partial liver transplant (LT), especially living donors, are at greater risk for portal vein complications. Hence, an adequate knowledge of this technique and its additional challenges in the post-LT patient setting is crucial. We provide an overview of the available literature on technical aspects for an MRB post-LT. Preoperative considerations are highlighted, along with intraoperative considerations and postoperative management. Special attention is given to the even-more-demanding aspect of performing an MRB post-liver transplantation with a left lateral segment. Surgical alternatives are also discussed. In addition, we report here a unique case in which this surgical technique was performed on a complex pediatric patient with a history of a living-donor LT with a left lateral segment graft over a decade ago.

Meso-Rex bypass versus portosystemic shunt for the management of extrahepatic portal vein obstruction in children: systematic review and meta-analysis

PURPOSE

Extrahepatic portal vein obstruction (EHPVO) is a major cause of non-cirrhotic portal hypertension in children. Surgical procedures for EHPVO include portosystemic shunts (PSS) and meso-Rex bypass (MRB). We conducted a systematic review and meta-analysis to compare the effectiveness of MRB versus PSS in EHPVO patients.

METHODS

A systematic literature search was performed using four databases. Articles reporting EHPVO and comparing patients who received MRB and PSS were included in the analysis.

RESULTS

We retrieved 851 papers, of which five observational studies met the inclusion criteria. There was no difference in shunt complications, mortality, or gastrointestinal bleeding after surgery between MRB and PSS in the meta-analysis. MRB had increased shunt complications compared with PSS in the non-comparative studies. MRB had a potential advantage over PSS in long-term prognosis in one comparative study. Overall, the quality of the evidence was low.

CONCLUSIONS

Based on available data, our meta-analysis indicates that MRB does not increase shunt complications, mortality, or gastrointestinal bleeding after surgery. The present study did not reveal superiority for either MRB or PSS. The paucity of well conducted trials in this area justifies future multicenter studies and studies that examine long-term outcomes.

Pediatric non-cirrhotic portal hypertension: Endoscopic outcome and perspectives from developing nations

Non-cirrhotic portal hypertension (NCPH) forms an important subset of portal hypertension in children. Variceal bleed and splenomegaly are their predominant presentation. Laboratory features show cytopenias (hypersplenism) and preserved hepatic synthetic functions. Repeated sessions of endoscopic variceal ligation or endoscopic sclerotherapy eradicate esophageal varices in almost all cases. After variceal eradication, there is an increased risk of other complications like secondary gastric varices, cholangiopathy, colopathy, growth failure, especially in extra-hepatic portal vein obstruction (EHPVO). Massive splenomegaly-related pain and early satiety cause poor quality of life (QoL). Meso-Rex bypass is the definitive therapy when the procedure is anatomically feasible in EHPVO. Other portosystemic shunt surgeries with splenectomy are indicated when patients present late and spleen-related issues predominate. Shunt surgeries prevent rebleed, improve growth and QoL. Non-cirrhotic portal fibrosis (NCPF) is a less common cause of portal hypertension in children in developing nations. Presentation in the second decade, massive splenomegaly and patent portal vein are discriminating features of NCPF. Shunt surgery is required in severe cases when endotherapy is insufficient for the varices. Congenital hepatic fibrosis (CHF) presents with firm palpable liver and splenomegaly. Ductal plate malformation forms the histological hallmark of CHF. CHF is commonly associated with Caroli’s disease, renal cysts, and syndromes associated with neurological defects. Isolated CHF has a favourable prognosis requiring endotherapy. Liver transplantation is required when there is decompensation or recurrent cholangitis, especially in Caroli’s syndrome. Combined liver-kidney transplantation is indicated when both liver and renal issues are present.

Optimal Rex shunt procedures as a treatment for pediatric extrahepatic portal hypertension

PURPOSE

To assess the long-term results after Rex bypass (RB) shunt and Rex transposition (RT) shunt and determine the optimal approach.

METHODS

Between 2010 and 2019, traditional RB shunt was performed in 24 patients, and modified RT shunt was performed in 23 children with extrahepatic portal hypertension (pHTN). A retrospective study was conducted based on comparative symptoms, platelet counts, color Doppler ultrasonography and computed tomographic portography of the portal system, and gastroscopic gastroesophageal varices postoperatively. The portal venous pressure was evaluated intraoperatively.

RESULTS

The operation in the RB group was notably more time-consuming than that in the RT group (P < 0.05). Compared to RT shunt, the reduction in gastroesophageal varix grading, the increases in platelets, and the caliber of the bypass were greater in the RB group (P < 0.05). Although not statistically significant, higher morbidity of surgical complications was found after RT shunt (17.4%) compared with RB shunt (8.3%) with patency rates of 82.6 and 91.7%, respectively. Additionally, patients exhibited a lower rate of rebleeding under the RB procedure (12.5%) than under the RT procedure (21.7%).

CONCLUSIONS

The RT procedure is an alternative option for the treatment of pediatric extrahepatic pHTN, and RB shunt is the preferred procedure in our center.

Surgical shunts for extrahepatic portal vein obstruction in pediatric patients: a systematic review

BACKGROUND

Extrahepatic portal vein obstruction (EHPVO) causes portal hypertension in noncirrhotic children. Among surgical treatments, it is unclear whether the meso-Rex shunt (MRS) or portosystemic shunt (PSS) offers lower post-operative morbidity and superior patency over time. Our objective was to evaluate long-term outcomes comparing MRS and PSS for pediatric patients with EHPVO.

METHODS

A systematic review was conducted of articles reporting children undergoing surgical shunts for EHPVO from 1/2000-2/2020. Of 87 articles screened, 22 were eligible for inclusion. The primary outcome was shunt thrombosis and secondary outcomes included non-operative complications, stenosis, and re-operation.

RESULTS

Eighteen of 22 studies were of good quality and four had fair quality. Of 461 patients included, 340 underwent MRS and 121 underwent PSS. MRS were associated with a higher rate of post-operative thrombosis when compared to PSS (14.1% vs 5.8%, p = 0.021). There were 40/340 MRS patients (11.8%) that required at least one re-operation for either shunt thrombosis or stenosis, versus 5/121 PSS patients (4.1%), p = 0.019.

CONCLUSION

Both MRS and PSS result in acceptable long-term patency rates, but the more technically demanding MRS is associated with higher post-shunt thrombosis, often requiring further operative intervention. This study suggests that PSS may offer advantages for pediatric patients with EHPVO.

Portosystemic shunt for portal hypertension after Kasai operation in patients with biliary atresia

PURPOSE

Many biliary atresia (BA) patients will eventually develop liver failure even after a successful Kasai portoenterostomy. A common complication of long-term BA survivors with their native liver is problematic portal hypertension. The aim of this study was to defend the view that portosystemic shunts can delay or negate the need for transplantation in these children.

METHODS

A retrospective single center review of the efficacy of portosystemic shunts in BA patients after a successful Kasai portoenterostomy was conducted.

RESULTS

From 1991 to 2017, 11 patients received portosystemic shunts. Median age of Kasai operation was 48 (36-61) days. Shunts were performed at the median age of 6.2 (4.1-6.8) years. Three of these eleven patients required subsequent liver transplantation. OS at 5 and 10 years were 90.9% and 81.8%, respectively. TFS at 5 and 10 years were 90.9% and 72.7%, respectively. Long-term complications included mild encephalopathy in 2 patients, hypersplenism in 3, and cholestasis in 1.

CONCLUSION

Portosystemic shunt for the treatment of portal hypertension in carefully selected BA patients is an effective option in delaying or negating the need for liver transplantation.

Sonographic features of umbilical vein recanalization for a Rex shunt on cavernous transformation of portal vein in children

BACKGROUND

The Rex shunt was widely used as the preferred surgical approach for cavernous transformation of the portal vein (CTPV) in children that creates a bypass between the superior mesenteric vein and the intrahepatic left portal vein (LPV). This procedure can relieve portal hypertension and restore physiological hepatopetal flow. However, the modified procedure is technically demanding because it is difficult to make an end-to-end anastomosis of a bypass to a hypoplastic LPV. Many studies reported using a recanalized umbilical vein as a conduit to resolve this problem. However, the feasibility of umbilical vein recanalization for a Rex shunt has not been fully investigated.

AIM

To investigate the efficacy of a recanalized umbilical vein as a conduit for a Rex shunt on CTPV in children by ultrasonography.

METHODS

A total of 47 children who were diagnosed with CTPV with prehepatic portal hypertension in the Second Hospital, Cheeloo College of Medicine, Shandong University, were enrolled in this study. Fifteen children received a recanalized umbilical vein as a conduit for a Rex shunt surgery and were enrolled in group I. Thirty-two children received the classic Rex shunt surgery and were enrolled in group II. The sonographic features of the two groups related to intraoperative and postoperative variation in terms of bypass vessel and the LPV were compared.

RESULTS

The patency rate of group I (60.0%, 9/15) was significantly lower than that of group II (87.5%, 28/32) 7 d after (on the 8^th d) operation (P < 0.05). After clinical anticoagulation treatment for 3 mo, there was no significant difference in the patency rate between group I (86.7%, 13/15) and group II (90.6%, 29/32) (P > 0.05). Moreover, 3 mo after (at the beginning of the 4^th mo) surgery, the inner diameter significantly widened and flow velocity notably increased for the bypass vessels and the sagittal part of the LPV compared to intraoperative values in both shunt groups (P < 0.05). However, there was no significant difference between the two surgical groups 3 mo after surgery (P > 0.05).

CONCLUSION

For children with hypoplastic LPV in the Rex recessus, using a recanalized umbilical vein as a conduit for a Rex shunt may be an effective procedure for CTPV treatment.

Liver disease in the older child

Liver disease in children tends to present either as: (i) an acute hepatitis with or without jaundice; (ii) incidental finding of abnormal liver function tests; or (iii) from a complication of portal hypertension with either haematemesis and/or incidental splenomegaly. Acute hepatitis may result from acute infection, prescribed or other drugs, ischaemia or vascular causes, autoimmune hepatitis, or idiopathic liver failure. Non-alcoholic fatty liver disease is now the most likely reason for abnormal liver function tests but medications, metabolic disease, cholangiopathy and non-liver causes should be considered. Autoimmune hepatitis and alpha-1-antitrypsin deficiency are the most likely causes of insidious liver disease. An international normalised ratio uncorrected by vitamin K reflects the severity of liver synthetic dysfunction, but not propensity to bleed. Creatine kinase helps to differentiate muscle from liver disease in patients with raised transaminases. Doppler ultrasound of hepatic vasculature is useful when assessing splenomegaly to differentiate extra-hepatic portal hypertension from inherent liver disease.

Sonographic Evaluation of a Unique Meso-Rex Shunt: A Case Study

Portal hypertension is a result of an increase in intrahepatic resistance in the main portal vein. The Meso-Rex shunt is used to bypass the obstructed portal vein and restore the venous flow into the liver. This procedure alleviates the need for a hepatic transplant. The Meso-Rex shunt has proven to be an effective treatment for extrahepatic portal vein obstruction, thus saving children from a complete transplant. There are variants to this bypass surgery, and sonography is commonly used to assess the condition pre- and postoperatively. In this case, the shunt was uniquely different from the typical Meso-Rex bypass surgery. Particular vasculature made it imperative for the sonographer to review the prior sonograms and review the chart information before preforming the examination. It should also be noted that sonographers must adapt the protocols to give the utmost treatment.

Standard or Variant Meso-Rex Shunts for Children with Variceal Bleeding due to Extrahepatic Portal Vein Obstruction: A Report of Two Cases

Extrahepatic portal vein obstruction (EHPVO) is the most common cause of pediatric portal hypertension and can cause life-threatening variceal bleeding. Meso-Rex shunt (MRS) is a surgical procedure that restores physiological portal venous blood flow to the liver by using a graft to connect the superior mesenteric vein and the left portal vein within the Rex recess, and can relieve variceal bleeding and other complications associated with EHPVO. Although the MRS is regarded as an optimal and potentially curative treatment with good long-term patency, graft thrombosis or failure due to unknown causes is not rare, prompting the need for further research on the risk factors of graft failure or poor patency. Herein, we report two cases of EHPVO in patients with recurrent or uncontrolled variceal bleeding, one treated with the classic Rex shunt and the other with the modified Rex shunt, which resulted in a failure and success, respectively.

Portosystemic shunt surgery in the era of TIPS: imaging-based planning of the surgical approach

PURPOSE

With the spread of transjugular intrahepatic portosystemic shunts (TIPS), portosystemic shunt surgery (PSSS) has decreased and leaves more complex patients with great demands for accurate preoperative planning. The aim was to evaluate the role of imaging for predicting the most suitable PSSS approach.

MATERIAL AND METHODS

Forty-four patients who underwent PSSS (2002 to 2013) were examined by contrast-enhanced CT (n = 33) and/or MRI (n = 15) prior to surgery. Imaging was analyzed independently by two observers (O1 and O2) with different levels of experience (O1 > O2). They recommended two shunting techniques (vessels and anastomotic variant) for each patient and ranked them according to their appropriateness and complexity. Findings were compared with the actually performed shunt procedure and its outcome.

RESULTS

The first two choices taken together covered the performed PSSS regarding vessels in 88%/100% (CT/MRI, O1) and 76%/73% (O2); and vessels + anastomosis in 79%/73% (O1) and 67%/60% (O2). The prediction of complex surgical procedures (resection of interposing structures, additional thrombectomy, use of a collateral vessel, and use of a graft interposition) was confirmed in 87%, resulting in 80% sensitivity and 96% specificity. Larger shunt vessel distances were associated with therapy failure (p = 0.030) and a vessel distance of ≥ 20 mm was identified as optimal cutoff, in which a graft interposition was used. There was no significant difference between MRI and CT in predicting the intraoperative decisions (p = 0.294 to 1.000).

CONCLUSION

Preoperative imaging and an experienced radiologist can guide surgeons in PSSS. CT and MRI provide the information necessary to identify technically feasible variants and complicating factors.

An unusual presentation of portal vein thrombosis in a 2-year-old girl

Portal vein thrombosis (PVT) is the most common cause of extrahepatic portal vein obstruction in children. Upper gastrointestinal (GI) bleeding and splenomegaly are the most common presenting features. PVT diagnosis is usually delayed in the absence of upper GI bleeding and many children undergo a hematologic work-up due to splenomegaly and signs of hypersplenism. Here, we present a case of a 2-year-old girl who had pancytopenia and splenomegaly. The hematologic work-up including a bone marrow aspirate was unrevealing and she was thought to have viral-induced bone marrow suppression and severe iron deficiency anemia. She presented 2 months later with hematemesis and abdominal CT angiography confirmed the diagnosis of PVT with portal cavernoma. Conclusion: PVT should be suspected in any child who presents with afebrile splenomegaly and signs of hypersplenism even in the absence of upper GI bleeding.

Long-term Outcomes and Health Perceptions in Pediatric-onset Portal Hypertension Complicated by Varices

OBJECTIVES

Outcomes of pediatric-onset portal hypertension are poorly defined. We aimed to assess population-based long-term outcomes of pediatric-onset portal hypertension complicated by varices.

METHODS

All children with esophageal varices (n = 126) were identified from 14,144 single nationwide referral center endoscopy reports during 1987 to 2013, and followed up through national health care and death registers. A questionnaire was sent to survivors (n = 94) of whom 65 (69%) responded.

RESULTS

Nineteen underlying disorders included biliary atresia (35%), extrahepatic portal vein obstruction (35%), autosomal recessive polycystic kidney disease (7%), and other disorders (23%). During median follow-up of 15.2 (range 0.5-43.1) years patients underwent median 9 (1-74) upper gastrointestinal endoscopies. Esophageal varices were first observed at a median age of 4.0 (0.3-18.2) years, 112 (89%) patients underwent median 6 (1-56) sclerotherapy/banding sessions, and 61 (48%) experienced median 2 (range 1-20) variceal bleeding episodes. Forty-eight surgical shunt procedures were performed to 41 (36%) patients and 38% underwent liver transplantation. Portal hypertensive biliopathy was diagnosed in 4 patients. Hepatopulmonary syndrome necessitated liver transplantation in 2 patients, hepatic encephalopathy in 2, and hepatorenal syndrome in 1. No patient died of variceal bleeding. Patient-reported perception of health on a scale of 1 to 10 was 9 (range 4-10), and 86% reported no current symptoms attributable to esophageal varices.

CONCLUSIONS

Pediatric-onset portal hypertension is a heterogeneous disease with significant long-term morbidity, requiring multimodal approach with considerable resources and continuation of follow-up in adulthood. Although mortality to variceal bleeding was avoided, bleeding episodes recurred also in adulthood, while patient-reported health of long-term survivors was encouraging.

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.

Noncirrhotic Portal Hypertension: Current and Emerging Perspectives

Idiopathic portal hypertension (IPH) and extrahepatic portal venous obstruction (EHPVO) are prototype noncirrhotic causes of portal hypertension (PHT), characterized by normal hepatic venous pressure gradient, variceal bleeds, and moderate to massive splenomegaly with preserved liver synthetic functions. Infections, toxins, and immunologic, prothrombotic and genetic disorders are possible causes in IPH, whereas prothrombotic and local factors around the portal vein lead to EHPVO. Growth failure, portal biliopathy, and minimal hepatic encephalopathy are long-term concerns in EHPVO. Surgical shunts and transjugular intrahepatic portosystemic shunt resolve the complications secondary to PHT. Meso-Rex shunt is now the standard-of-care surgery in children with EHPVO.

Etiology, presenting features and outcome of children with non-cirrhotic portal vein thrombosis: A multicentre national study

OBJECTIVES

Non-cirrhotic portal vein thrombosis (PVT) is a main cause of portal hypertension in children. We describe the characteristics at presentation and outcome of a cohort of patients with PVT to determine clinical features and predictors of outcome.

METHODS

We recorded: (1) Associated factors: prematurity, congenital malformations, neonatal illnesses, umbilical vein catheterization (UVC), deep infections, surgery; (2) congenital and acquired prothrombotic disorders; (3) features at last follow up including survival rate and need for surgery.

RESULTS

187 patients, mean age at diagnosis 4 ± 3.7 years, had a history of prematurity (61%); UVC (65%); neonatal illnesses (79%). The diagnosis followed the detection of splenomegaly (40%), gastrointestinal bleeding (36%), hypersplenism (6%), or was incidental (18%). Of 71 patients who had endoscopy at presentation 62 (87%) had oesophageal varices. After 11.3 years' follow up 63 (34%) required surgery or TIPS. Ten-year survival rate was 98%, with 90% shunt patency. Spleen size, variceal bleeding and hypersplenism at presentation were predictors of surgery or TIPS (p < 0.05).

CONCLUSION

PVT is associated with congenital and acquired co-morbidities. History of prematurity, neonatal illnesses and UVC should lead to rule out PVT. Large spleen, variceal bleeding and hypersplenism at presentation predict the need for eventual surgery in a third of cases.

The role of surgical shunts in the treatment of pediatric portal hypertension

BACKGROUND

Portal diversion by surgical shunt plays a major role in the treatment of medically refractory portal hypertension. We evaluate our center's experience with surgical shunts for the treatment of pediatric portal hypertension.

METHODS

All patients who underwent surgical shunt at a single institution from 2008 to 2017 were reviewed. The primary outcome was intervention-free shunt patency.

RESULTS

In this study, 34 pediatric patients underwent portal shunt creation. The median age was 7.7 years (interquartile range 4.3-12.0). Twenty-nine patients (85%) had prehepatic portal hypertension and 5 patients (15%) had intrahepatic portal hypertension. The primary manifestations of portal hypertension were esophageal varices (97%) and gastrointestinal bleeding (77%). Eighteen patients (53%) underwent meso-Rex bypass, 10 patients (29%) underwent splenorenal shunt, and 6 patients (18%) underwent mesocaval shunt. Outcomes were notable for minimal wound complications (9%), rebleeding events (12%), and mortality (3%). In the postoperative setting, 10 patients (29%) experienced a shunt complication (occlusion or stenosis), 4 of which occurred in the early postoperative period and required urgent intervention. The 1-year and 5-year "primary patency" patency rates were 71% and 66%, respectively.

CONCLUSION

Children suffer significant morbidity from the sequelae of portal hypertension. Our experience reinforces the feasibility of surgical shunts as an effective treatment option associated with low rates of morbidity and mortality.

Revision of meso-Rex bypass utilizing a collateral vein in a patient with portal steal phenomenon after liver transplant: A case report

•

Re-do of a meso-Rex Bypass is a feasible option with good outcomes.

•

A large collateral vein is an alternative for an autologous venous conduit in a MRB.

•

Large collaterals ligation during MRB should be performed to avoid portal steal.

Introduction

In children with extrahepatic portal vein obstruction or those who develop portal vein thrombosis after liver transplant, the use of Meso-Rex Bypass (MRB) creates a more physiological state by redirecting mesenteric blood flow back into the intrahepatic portal system via a venous conduit.

Presentation of case

A 3-year-old female with biliary atresia associated with polysplenia syndrome and a surgical history of Kasai portoenterostomy procedure, and an ABO incompatible whole liver transplant. Within a year after transplant she presented with prehepatic portal hypertension, that was treated with MRB using a deceased donor ABO compatible iliac vein as conduit. Six months later, she was taken to the operating room for bypass revision, during the procedure the MRB showed no flow and no thrombus, and a large splenorenal collateral vein that was causing a portal perfusion steal phenomenon was observed. After dissecting the collateral vein, an 8 cm x8 mm segment of this vessel was used as an autologous conduit to re-do the Rex.

Discussion

Failed of MRB can be attributed to portal steal phenomenon, hypercoagulable disorders, bypass contraction or kinking. In this case we believe the culprit to be the former. When there is a history of longstanding portal hypertension, large collaterals develop; thus, intraoperative portal vein flow measurement is critical and ligation of large collaterals during liver transplantation and MRB should be performed to avoid portal steal phenomenon postprocedure.

Conclusion

Using a collateral vein as an alternative autologous venous conduit is a feasible option that can have durable success.

Recanalization of Chronic Extrahepatic Portal Vein Obstruction in Pediatric Patients Using a Minilaparotomy Approach

PURPOSE

Extrahepatic portal vein obstruction (EHPVO) is the most frequent cause of portal hypertension in children. Some patients are not amenable to meso-Rex bypass and alternative surgeries do not restore physiologic flow. We aim to demonstrate the feasibility and safety of minilaparotomy for recanalization of chronic EHPVO.

METHODS

This 2013-2015 single-center, retrospective review included pediatric patients with chronic EHPVO who underwent minilaparotomy, mesenteric vein access, and attempted recanalization of the occluded portal vein. Outcomes included portal patency, resolution of variceal bleeding, size and number of varices, spleen size, and platelet count.

RESULTS

There were 6 EHPVO patients. The median age was 9.9 years and median duration of EHPVO was 7 years (3-16 years). EHPVO etiologies were liver transplantation (50%), idiopathic (33%), and umbilical vein catheterization (17%). Four patients (67%) had successful portal vein recanalization and stenting. At last follow-up [median 3.1 years (2.2-4.3 years)] all successfully recanalized patients had patent portal vein stents and resolution of varices and variceal bleeding. The median reduction in spleen size was 26%, with improvement in platelet counts (50-310/μL). The 2 patients with an idiopathic etiology may have never had a main extrahepatic portal vein based on imaging, and both were unable to be recanalized.

CONCLUSIONS

Recanalization and stenting of a prolonged occlusion of the portal vein via a minilaparotomy approach is feasible, safe, and may provide an alternative to shunt surgery or endoscopic therapy in selected patients.

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

BACKGROUND

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.

OBJECTIVES

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.

MATERIALS AND METHODS

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.

RESULTS

Twenty-five children (median age: 9.5 years) 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 127 K/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).

CONCLUSION

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.

Portal-to-right portal vein bypass for extrahepatic portal vein obstruction

OBJECTIVE

Rex shunt (mesenteric-to-left portal vein bypass) is considered a more physiologically rational treatment for EHPVO than other portosystemic systemic shunts in children. However, about 13.6% of children with EHPVO do not have usable left portal veins and up to 28.1%. Rex operations in children are not successful. Hence, a Rex shunt in these children was impossible. This study reports a novel approach by portal-to-right portal vein bypass for treatment of children with failed Rex shunts.

MATERIAL AND METHODS

Eight children (age 6.1years, range 3.5-8.9years) who underwent Rex shunts developed recurrent gastrointestinal bleeding and hypersplenism 13months (11-30months) postoperatively. After ultrasound confirmation of blocked shunt, they underwent exploration. Three patients were found to have right portal vein agenesis. Five patients (62.5%) were found to have the patent right portal vein, with the diameter of 3-6mm. Four patients underwent bypass between the main portal vein in the hepatoduodenal ligament and the right portal vein by interposing an inferior mesenteric vein autograft, whereas the remaining patient underwent a bypass using ileal mesenteric vein autograft.

RESULTS

The operations took 2.3h (1.9-3.5h). The estimated blood loss was 50ml (30-80ml), with no complication. The portal venous pressure dropped from 34.6cmH₂O (28-45 cmH₂O) before the bypass to 19.6cmH₂O (14-24cmH₂O) after the bypass. The 5 patients were followed up for 10.2months (4-17months) and the post-operative ultrasound and CT angiography confirmed the patency of all the grafts and disappearance of the portal venous cavernova in all five patients.

CONCLUSION

The portal-to-right portal vein bypass technique is feasible and safe for treatment of children with EHPVO who have had failed Rex shunts. Our preliminary result indicates that this technique extends the success of Rex shunt from left portal vein to right portal vein and open a new indication of physiological shunt for some of the children who not only have had failed Rex shunts or but also are not suitable for the Rex shunts.

TYPE OF STUDY

Treatment study.

LEVEL OF EVIDENCE

Level IV.

Liver atrophy and regeneration in noncirrhotic portal vein thrombosis: Effect of surgical shunts

The goal of the study is to characterize the relationship between portal vein thrombosis (PVT) and hepatic atrophy in patients without cirrhosis and the effect of various types of surgical shunts on liver regeneration and splenomegaly. Patients without cirrhosis with PVT suffer from presinusoidal portal hypertension, and often hepatic atrophy is a topic that has received little attention. We hypothesized that patients with PVT have decreased liver volumes, and shunts that preserve intrahepatic portal flow enhance liver regeneration. Sixty-four adult and pediatric patients with PVT who underwent surgical shunt placement between 1998 and 2011 were included in a retrospective study. Baseline liver volumes from adult patients were compared with standard liver volume (SLV) as well as a group of healthy controls undergoing evaluation for liver donation. Clinical assessment, liver function tests, and liver and spleen volumes from cross-sectional imaging were compared before and after surgery. A total of 40 patients received portal flow-preserving shunts (32 mesoportal and 8 selective splenorenal), whereas 24 received portal flow-diverting shunts (16 nonselective splenorenal and 8 mesocaval). Baseline adult liver volumes were 26% smaller than SLV (1248 versus 1624 cm³ ; P = 0.02) and 20% smaller than the control volumes (1248 versus 1552 cm³ ; P = 0.02). Baseline adult spleen volumes were larger compared with controls (1258 versus 229 cm³ ; P < 0.001). Preserving shunts were associated with significant increase in liver volumes (886 versus 1131 cm³ ; P = 0.01), whereas diverting shunts were not. Diverting shunts significantly improved splenomegaly. In conclusion, we have demonstrated that patients without cirrhosis with PVT have significant liver atrophy and splenomegaly. Significant liver regeneration was achieved after portal flow-preserving shunts. Liver Transplantation 24 881-887 2018 AASLD.

Clinical and Imaging Predictors of Surgical Splenorenal Shunt Dysfunction in Pediatric Patients

PURPOSE

Few established criteria exist to prompt angiographic evaluation and intervention for surgically created splenorenal shunts (SRS). Clinical and Doppler ultrasound (DUS) imaging predictors of shunt dysfunction were evaluated in this retrospective study.

MATERIALS AND METHODS

Consecutive patients undergoing SRS angiography over a 10-year period were retrospectively identified. Preangiography platelet count and DUS measurements of spleen diameter, maximum splenic vein velocity, and maximum shunt velocity were assessed and compared to findings at subsequent catheter angiography.

RESULTS

Twenty-six SRS angiograms were performed in 16 patients. Two of the 26 procedures were excluded from analysis due to insufficient baseline preangiography clinical and DUS data. In the remaining 24 cases, significant stenosis/occlusion was confirmed at angiography in 20, whereas wide patency was seen in 4. For the 20 cases of angiographically confirmed significant stenosis/occlusion, when compared to baseline post-SRS creation to immediate preangiography evaluation there was a greater decrease in platelet count (-51.8% vs -19.4%), a greater increase in spleen diameter (+13.4% vs +3.7%), a greater increase in maximum shunt velocity (+74.7% vs +59.7%), and a greater decrease in splenic vein velocity (-25.0% vs -18.5%).

CONCLUSION

Clinical evidence of splenic sequestration and DUS finding of increased maximum shunt velocity correlate with angiographic findings of SRS dysfunction and could be used to help predict the need for shunt intervention.

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.

Surgical treatment for rebleeding caused by bypass failure after Rex shunt: re-Rex shunt or Warren shunt?

PURPOSE

Although Rex shunt is an effective treatment for extrahepatic portal venous obstruction (EHPVO), 4-20% children develop rebleeding postoperatively. This study was used to evaluate the surgical treatment of rebleeding after Rex shunt in our center.

METHOD

From June 2008 to Jan 2017, 12 of 122 children with EHPVO underwent a second operation due to graft stenosis and occlusion after Rex shunt in our center. The abdominal ultrasound and computed tomography (CT) showed the occlusion of bypass vein in nine children, stenosis of bypass vein in two children, and the patency of bypass vein in one child with dysplasia of intrahepatic portal vein. A re-Rex shunt was performed in eight children, of which one child required conversion to Warren shunt due to postoperative rebleeding. Five children underwent Warren shunt due to a narrowed left portal vein shown by intraoperative portal angiography and surgical exploration. All patients were followed up in this study.

RESULTS

The postoperative incidences of re-bleeding and esophageal varices in children with Warren shunt were significantly lower than those in children undergoing re-Rex shunt (P = 0.027 and 0.015). After a second operation, the rate of bypass vein patency in children with re-Rex shunt was lower than that in children with Warren shunt (50 vs. 100%). The postoperative reduced size of spleen in children undergoing Warren shunt was significantly higher than that of children undergoing re-Rex shunt (P < 0.05).

CONCLUSIONS

Comparing to re-Rex shunt, Warren shunt was a better treatment for rebleeding caused by bypass failure after Rex shunt.

Vascular liver diseases on the clinical side: definitions and diagnosis, new concepts

The components of the hepatic vascular system (hepatic arteries, portal and hepatic veins, sinusoids, and lymphatics) can be damaged by various types of injury. Each of the resulting conditions is rare, which has limited knowledge and awareness. In the last two decades, international collaborations have allowed to reach critical masses of data, which has driven significant progresses in understanding and management of vascular disorders of the liver. The present paper discusses definitions, denominations, and diagnosis of such vascular disorders with the exception of those affecting hepatic arteries. Evolving pathogenic or pathophysiologic views relevant to the clinical aspects are also overviewed.