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

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.

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.

Portosystemic Shunt Surgery for Extrahepatic Portal Venous Obstruction Beyond Endoscopic Variceal Eradication: Two Decades of Pediatric Surgical Experience

Background

This exclusively surgical series on pediatric extrahepatic portal venous obstruction (EHPVO) defines surgical indications beyond endoscopic eradication of esophageal varices (EEEV), the selection of an appropriate surgical procedure, and the long-term post-surgical outcome.

Methods

EHPVO management protocol at the reporting institute has been endotherapy until esophageal variceal eradication and surgery for select adverse sequelae manifesting after EEEV.

Results

One hundred and thirty-nine EHPVO cases underwent surgery for the following indications in combination: i) massive splenomegaly with severe hypersplenism (n = 132, 95%); ii) growth retardation (GR, n = 95, 68%); iii) isolated gastric (IGV) and ectopic varices (n = 49, 35%); iv) Portal cavernoma cholangiopathy (PCC) (n = 07, 5%). A portosystemic shunt (PSS) was performed in 119 (86%) cases. Types of PSS performed were as follows: central end-to-side splenorenal shunt with splenectomy (n = 104); side-to-side splenorenal shunt (n = 4); mesocaval shunt (n = 1); inferior mesenteric vein (IMV) to left renal vein shunt (n = 2); IMV to inferior vena cava shunt (n = 3); H-graft interposition splenorenal shunt (n = 1); spleno-adrenal shunt (n = 3); makeshift shunt (n = 1). Esophagogastric devascularization (n = 20, 14%) was opted for only for non-shuntable anatomy. At a median follow-up (FU) of 41 (range: 6-228) months, PSS block was detected in 13 (11%) cases, with recurrent variceal bleeding in 4 cases. PCC-related cholestasis regressed in 5 of 7 cases. Issues of splenomegaly were resolved, and growth z-scores improved significantly.

Conclusions

Endotherapy for secondary prophylaxis until EEEV has resulted in a shift in surgical indications for EHPVO. Beyond EEEV, surgery was indicated predominantly for non-variceal sequelae, namely massive splenomegaly with severe hypersplenism, GR, and PCC. Varices warranted surgery infrequently but more often from sites less amenable to endotherapy, i.e., IGV and ectopic varices. The selection of PSS was tailored to anatomy and surgical indications. On long-term FU post surgery, PSS block was detected in 13% of patients. PCC-related cholestasis regressed in 71%, and issues of splenomegaly resolved with significantly improved growth Z scores.

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.

Balloon angioplasty versus stent placement for the treatment of portal vein stenosis in children: a single center experience

PURPOSE

To evaluate the safety and efficacy of percutaneous interventional treatment of portal vein stenosis in children.

MATERIAL AND METHODS

A retrospective analysis of all interventional treatments for portal vein stenosis in pediatric patients at a single institution from 2010 to 2021 was conducted. Platelet count, spleen size and portal vein flow velocity were assessed during the follow-up period. Primary and primary assisted patency time were determined.

RESULTS

A total of ten children (median age 28.5 months, interquartile range (IQR): 2.75-52.5 months) with portal vein stenosis after Mesorex-Shunt (n = 4), liver transplantation (n = 3) and other etiologies (n = 3) underwent 15 interventional procedures. There were five reinterventions and one discontinued intervention. The technical success rate was 93.3% (14/15) and clinical success of treated patients was 100% (14/14). Median follow-up was 18 months (IQR: 13.5-81 months). The median primary patency time for stent placement was 70 months (IQR: 13.5-127.25 months). For balloon angioplasty, the median primary patency time was 9 months (IQR 7.25-11.5 months), while the median assisted primary patency time was 14 months (IQR: 12 to 15 months). Platelet count, spleen size and portal vein flow velocity reliably corresponded to recurrence of portal vein stenosis in asymptomatic patients during follow-up.

CONCLUSION

Interventional treatment is a safe and efficient method to treat portal vein stenosis with long patency times, regardless of etiology. Primary stent placement shows a higher primary patency time than balloon angioplasty. Implementation of stent placement as the primary interventional method may improve patency times and reduce the need for repeat reinterventions in pediatric patients.

REX SHUNT IN CHILDREN: COULD DYSFUNCTION BE PROGNOSED? A RETROSPECTIVE ANALYSIS

OBJECTIVE

The aim: To analyze retrospectively our experience of Rex shunt in children with symptomatic portal hypertension, its effect on hypersplenism regression and varices eradication, assess shunt survival and investigate risk factors, that could lead to shunt dysfunction and thrombosis.

PATIENTS AND METHODS

Materials and methods: 24 children (16 males, 8 females) ,with portal hypertension included into the study. All surgeries were performed within single center in a period from January 2010 to March 2022. Follow up period was 6.75±1.19 years.

RESULTS

Results: Age at diagnosis was 5.39±0.64 years. 5 (20.8%) had umbilical catheter in anamnesis. 16 (66.7%) manifested bleeding episodes as the first sign of portal hypertension. 9 (37.5%) of children manifested severe hypersplenism. Age at Rex shunting was 7.5±0.7 years. In 7 (31.8%) cases Rex shunt thrombosis occurred. 1 successful thrombectomy and 6 splenorenal shunting were performed. Kaplan-Meyer analysis showed Rex shunt survival 0.670 (95%CI 0.420-0.831). Logistic regression model indicated thrombocytes count (p=0.0423) and cytopenia (p=0.0272) as factors that could influence shunt thrombosis. Follow-up group included 18 patients. Spleen volume regression became significant by 1 p/o year p<0,05, thrombocytes significant increasement reached in 1 p/o months (p<0.01), varices involution was achieved by 1 p/o year (p<0,001).

CONCLUSION

Conclusions: Rex shunt effectiveness in study group was 70.9%., shunt survival assessed 0.670 (95%CI 0.420-0.831). Rex shunt was effective in bleeding prophylaxis in all patients of follow up group. Preoperative thrombocytes count (p=0.0423) and cytopenia (p=0.0272) were detected as factors that could influence shunt thrombosis, that is to be considered in RS preoperative period and require following studies.

The rex shunt for left portal vein reconstruction during hepatectomy for malignancy using of rex-shunt in adults for oncoliver surgery

BACKGROUND

Immediate portal reperfusion is mandatory following hepatectomy combined with portal vein (PV) resection. This retrospective study analyzes the feasibility and the outcomes of the Rex shunt (RS) for reconstruction of the left portal vein (LPV) and reperfusion of the remnant left liver or lobe following hepatectomy for cancer combined with resection of the PV in adult patients.

METHODS

From 2018 to 2021, an RS was used in the above setting to achieve R0 resection or when the standard LPV reconstruction failed or was deemed technically impossible.

RESULTS

There were 6 male and 5 female patients (median age, 58 years) with perihilar cancer (5 cases) or miscellaneous cancers invading the PV (6 cases). A major hepatectomy was performed in 10/11 patients. The RS was indicated to achieve R0 resection or for technical reasons in 8 and 3 cases, respectively, and was feasible in all consecutive attempts with (10 cases) or without an interposed synthetic graft (1 case). Two fatal complications (PV thrombosis and pulmonary embolism) and three non-severe complications occurred in four patients within 90 days of surgery. Two patients died of tumor recurrence with a patent RS at 13 and 29 months, and 7 were recurrence free with a patent shunt with a follow-up of 1 to 37 months (median, 15 months).

CONCLUSION

In case of remnant left liver or lobe following hepatectomy combined with resection of the PV, the RS may help to achieve R0 resection and is a valuable option to perform technically satisfying portal reperfusion of the remnant left liver or lobe.

The Role of Imaging in Portal Vein Thrombosis: From the Diagnosis to the Interventional Radiological Management

PURPOSE

To illustrate diagnostic and interventional imaging for the characterization and treatment of portal vein thrombosis (PVT).

INTRODUCTION

The broad spectrum of congenital and acquired PVT manifestations is illustrated, with a focus on the pediatric population; diagnostic and interventional imaging techniques are described.

DESCRIPTION

PVT frequently presents as an incidental finding at imaging in the screening for liver diseases or for other unrelated reasons. PVT can be classified based on: extension (intrahepatic, extrahepatic, involving the spleno-mesenteric tract, etc.); degree (partial or complete); onset (acute or chronic); and with or without cavernomatous transformation. This comprehensive review relies on the experience gained from a large series of congenital and acquired PVT in a referral center for pediatric and adult liver transplantation. Diagnostic and interventional imaging techniques are described, including: color-Doppler and contrast-enhanced Ultrasound; CT and MR angiography; retrograde portography; percutaneous transhepatic, transplenic, and transmesenteric portography; transjugular intrahepatic portosystemic shunt creation. Pre- and post-operative imaging assessment of the surgical meso-rex bypass is discussed. The description is enriched with an original series of pictorial imaging findings.

CONCLUSION

PVT is a clinical condition associated with significant morbidity and mortality. Diagnostic and interventional imaging plays a crucial role in both conservative and operative management.

Young boy with a long history of splenomegaly and cytopenia

A 15-year-old boy was admitted with a history of cytopenia (white blood cell count 3.170/μm, platelets 90.000/μm) associated with splenomegaly, found during investigations for recurrent mild jaundice due to Gilbert's syndrome.He was in good general health, without systemic symptoms; therefore, the leading causes of asymptomatic splenomegaly were excluded. Coagulation, liver tests and abdomen ultrasound (US) were normal, showing a hepatopetal portal flow to the colour-Doppler. There was no sign of haemolysis on haematology investigations. The C reactive protein, immune globulins levels and erythrocyte sedimentation rate were normal, excluding both an infective and an immune regulation disorder. We excluded the haematological malignancy and lymphoproliferative disorders through a peripheral blood smear and a bone marrow biopsy.His history was remarkable for neonatal sepsis, which required umbilical venous catheter during hospitalisation in a neonatal intensive care unit (NICU). The patient follow-up was interrupted for a while, probably due to his good health condition.At age 17 years, the child accessed our emergency department. for a minor trauma to the limbs, and his physical examination was unremarkable, except for the splenomegaly. We repeated the abdomen US, with colour flow Doppler (figure 1).

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.

LOCAL DIAGNOSTIC REFERENCE LEVELS FOR PEDIATRIC RETROGRADE WEDGE PORTOGRAPHY INTERVENTIONAL PROCEDURES USING A DOSE MONITORING SOFTWARE AT A TRANSPLANTATION INSTITUTE

The aim of this work was to establish local diagnostic reference levels (DRLs) for retrograde wedge portography (RWP) performed on pediatric patients assessing the usefulness of radiation dose monitoring software in the establishing process. Between September 2016 and April 2020, 66 consecutive RWP were performed at a transplantation institute and were included in our study. Patients were divided in three groups according to age: n = 25 infants, n = 20 middle childhood and n = 21 early adolescence. The third quartile of both Air Kerma at the reference point (Ka,r) and air kerma-area product (PKA) were evaluated to establish local DRLs (lDRLs). In addition, to control high Ka,r levels during procedures, the software notified to operators if Ka,r exceeded the dose 'alert' threshold set at 2 Gy. lDRLs were established for all three groups using PKA and Ka,r: infant group: 5.6 Gy.cm 2 and 0.034 Gy; middle childhood: 6.4 Gy.cm2 and 0.018 Gy and early adolescence: 12.8 Gy.cm2 and 0.059 Gy. The dose threshold 'alert' was never encountered (alert quota: 0%). The dose monitoring system supports the feasibility of accurate and easier lDRLs' establishment.

Meso-Rex bypass for the management of extrahepatic portal vein obstruction in adults (with video)

BACKGROUND

Extrahepatic portal vein obstruction (EHPVO) results in severe portal hypertension (PHT) leading to severely compromised quality of life. Often, pharmacological and endoscopic management is unable to solve this problem. Restoring hepatic portal flow using meso-Rex bypass (MRB) may solve it. This procedure, uncommon in adult patients, is considered the treatment of choice for EHPVO in children.

METHODS

From 1997 to 2018, 8 male and 6 female adults, with a median age of 51 years (range 22-66) underwent MRB procedure for EHPVO at the University Hospitals Saint-Luc in Brussels, Belgium. Symptoms of PHT were life altering in all but one patient and consisted of repetitive gastro-intestinal bleedings, sepsis due to portal biliopathy, and/or severe abdominal discomfort. The surgical technique consisted in interposition of a free venous graft or of a prosthetic graft between the superior mesenteric vein and the Rex recess of the left portal vein.

RESULTS

Median operative time was 500 min (range 300-730). Median follow-up duration was 22 months (range 2-169). One patient died due to hemorrhagic shock following percutaneous transluminal intervention for early graft thrombosis. Major morbidity, defined as Clavien-Dindo score ≥ III, was 35.7% (5/14). Shunt patency at last follow-up was 64.3% (9/14): 85.7% (6/7) of pure venous grafts and only 42.9% (3/7) of prosthetic graft. Symptom relief was achieved in 85.7% (12/14) who became asymptomatic after MRB.

CONCLUSIONS

Adult EHPVO represents a difficult clinical condition that leads to severely compromised quality of life and possible life-threatening complications. In such patients, MRB represents the only and last resort to restore physiological portal vein flow. Although successful in a majority of patients, this procedure is associated with major morbidity and mortality and should be done in tertiary centers experienced with vascular liver surgery to get the best results.

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.

Angioplasty With Stent Implantation for Portal Venous Stenosis Caused by Abdominal Tuberculosis: A Case Report and Literature Review

Abdominal tuberculosis is one of common forms of extra-pulmonary tuberculosis. However, portal vein involvement leading to portal venous stenosis and portal hypertension is a rare complication in abdominal tuberculosis. Because of the non-specific presentations and insensitive response to anti-tuberculosis therapy of the lesions involving portal vein, it continues to be both a diagnostic and treatment challenge. We have reported a 22-year-old woman presented with massive ascites and pleural effusion, which was proved to be TB infection by pleural biopsy. After standard anti-tuberculosis therapy, her systemic symptoms completely resolved while ascites worsened with serum-ascites albumin gradient >11 g/L. Contrast-enhanced computed tomography and portal venography showed severe main portal vein stenosis from compression by multiple calcified hilar lymph nodes. Finally, the patient was diagnosed with portal venous stenosis due to lymphadenopathy after abdominal tuberculosis infection. Portal venous angioplasty by balloon dilation with stent implantation was performed and continued anti-tuberculosis therapy were administrated after discharge. The ascites resolved promptly with no recurrence occurred during the six-month follow-up. Refractory ascites due to portal venous stenosis is an uncommon vascular complication of abdominal tuberculosis. Portal venous angioplasty with stent placement could be a safe and effective treatment for irreversible vascular lesions after anti-tuberculosis therapy.

Modified Meso-Rex bypass with umbilical vein recanalization and intra-operative stenting

PURPOSE

The aim of the study was to evaluate the usefulness of a novel modified Meso-Rex bypass surgical technique with umbilical vein recanalization and intra-operative stenting to treat portal vein cavernous transformation.

METHODS

In total, 13 portal vein cavernous transformation patients underwent Meso-Rex bypass surgery, consisting of bypass grafts between the superior mesenteric vein (SMV) and the recess of Rex as well as through the ligamentum teres hepatis without stent implantation (Group A, n = 9) and umbilical vein recanalization with intra-operative stent implantation (Group B, n = 4).

RESULTS

In Group A, the bypass diameter was 0-6 mm (median 3 mm) and blood flow velocity 25-115 cm/s (median 72 cm/s) 1 month after Meso-Rex bypass surgery, with open bypass times of 0-67 months (median 6 months); 6 patients in this group developed postoperative Meso-Rex bypass occlusions. A patient in Group A treated with ligamentum teres hepatis recanalization needed a thrombectomy and stent implantation during a second surgery 2 days after the Meso-Rex bypass, because of bypass thrombosis and umbilical vein stenosis. In Group B, the average modified Meso-Rex bypass diameter was 5.5-6.5 mm (median 6 mm), and the bypass vessels remained open in all patients, with blood flow rates of 45-100 cm/s (median 76.5 cm/s) 1 month after the modified Meso-Rex bypass, up to the endpoint (15-33 months, median 24 months). The rate of bypass occlusions in Group A and Group B were 22.2% and 0%, 30.0% and 0%, and 55.6% and 0% at 1 month, 3 months, and 1 year, respectively, after bypass surgery.

CONCLUSIONS

Our novel modified Meso-Rex bypass approach for portal vein cavernous transformation treatment was effective with excellent long-term bypass patency.

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

Background

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

Results

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

Conclusions

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

Urgent intraoperative endovascular stent placement to resolve acute hepatic or portal venous obstruction during liver surgery: a case series

Background

Acute obstruction of the hepatic vein (HV) or the portal vein (PV), particularly when it occurs during liver surgery, is potentially fatal unless repaired swiftly. As surgical interventions for this problem are technically demanding and potentially unsuccessful, other treatment options are needed.

Case presentation

We report two cases of acute, surgically uncorrectable HV or PV obstruction during liver resection or living donor liver transplantation (LDLT), which was successfully treated with urgent intraoperative placement of endovascular stents using interventional radiology (IVR). In Case 1, a patient with colonic liver metastases underwent a non-anatomic partial hepatectomy of the segments 4 and 8 with middle hepatic vein (MHV) resection. Additionally, the patient underwent an extended right posterior sectionectomy with right hepatic vein (RHV) resection for tumors involving RHV. Reconstruction of the MHV was needed to avoid HV congestion of the anterior section of the liver. The MHV was firstly reconstructed by an end-to-end anastomosis between the MHV and RHV resected stumps. However, the reconstruction failed to retain the HV outflow and the anterior section became congested. Serial trials of surgical revisions including re-anastomosis, vein graft interposition and vein graft patch-plasty on the anastomotic wall failed to recover the HV outflow. In Case 2, a pediatric patient with biliary atresia underwent an LDLT and developed an intractable PV obstruction during surgery. Re-anastomosis with vein graft interposition failed to restore the PV flow and elongated warm ischemic time became critical. In both cases, the misalignment in HV or PV reconstruction was likely to have caused flow obstruction, and various types of surgical interventions failed to recover the venous flow. In both cases, an urgent IVR-directed placement of self-expandable metallic stents (SEMS) restored the HV or PV perfusion quickly and effectively, and saved the patients from developing critical conditions. Furthermore, in Cases 1 and 2, the SEMS placed were patent for a sufficient period of time (32 and 44 months, respectively).

Conclusions

The IVR-directed, urgent, intraoperative endovascular stenting is a safe and efficient treatment tool that serves to resolve the potentially fatal acute HV or PV obstruction that occurs in the middle of liver surgery.

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.

OCCUPATIONAL RADIATION DOSE PERFORMING HEPATOBILIARY MINIMALLY INVASIVE PROCEDURES IN CHILDREN WEIGHING LESS THAN 20 kg

Our objective is to retrospectively evaluate the effective dose (E) of operators performing pediatric Hepatobiliary Minimally Invasive Procedures (HMIP). Between October 2015 and December 2017, 58 consecutive HMIP were performed on 26 children weighing less than 20 kg (mean 12.3 kg, median 13 kg, range 2.4-20 kg). About 31 vascular procedures (n = 9 hepatic venograms with/without stenting; n = 9 retrograde wedge portography; n = 8 transhepatic portography with angioplasty and/or stenting and n = 5 hepatic arteriography/embolization) and 27 non-vascular procedures (n = 6 percutaneous transhepatic biliary drainage (PTBD); n = 3 bilioplasty; n = 15 biliary catheter change and n = 3 cholangiogram) were performed. Electronic personal dosimeters were used to measure radiation doses to the interventional radiologist, radiographer and anesthesia nurse. The results shows the highest mean effective dose: interventional radiologist's in PTBD (1.18 μSv); radiographer's in hepatic veins phlebography with/without stenting (0.25 μSv) and nurse's in hepatic arteriography/embolization (0.26 μSv). Operators' E can vary depending on the complexity of procedure performed and the position of the operators within the angiosuite.

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

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

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

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

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

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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.

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.

Porto-Rex Shunt for Left Portal Vein Reconstruction During Right Extended Hepatectomy for Advanced Extrahepatic Biliary Cancer

Resection offers the only chance of long-term survival or cure for perihilar cancer, provided R0 resection is achieved with margin-negative status of the remnant liver, bile duct, proximal hepatic artery, and portal vein. End-to-end anastomosis of the portal trunk to the left portal branch is the conventional portal reconstruction in cases of right extended hepatectomy requiring resection of the portal vein bifurcation. This mandatory reconstruction may be challenging due to (1) vessel incongruence, (2) fragility of the left portal branch wall, and more importantly, and (3) the divergent orientation of the two vessels exposing to vascular twisting/kinking. We report here the first two cases of porto-Rex shunt, between the portal vein trunk and the left portal vein in the umbilical fissure during right extended hepatectomy for advanced extrahepatic biliary cancer: one following failed conventional portal reconstruction and one to achieve macroscopically complete resection.

Combined Rex-bypass shunt with pericardial devascularization alleviated prehepatic portal hypertension caused by cavernomatous transformation of portal vein

OBJECTIVE

To evaluate the effects of combined Rex-bypass shunt and pericardial devascularization on prehepatic portal hypertension secondary to cavernomatous transformation of portal vein (CTPV).

METHODS

Forty-two patients aged from 3 years to 49 years (divided into 3 groups), 26 cases male and 16 female, with prehepatic vascular hepertention were treated with Rex-bypass shunt combined with pericardial devascularization. In each patient, preoperative assessment included ultrasound and computed tomographic angiography of the portal vein and blood analysis. The procedure was Rex-bypass shunt (with or without graft), and patients with moderate or severe gastroesophageal varices required additional paraesophagogastric devascularization. Splenectomy or subtotal splenectomy was performed if combined hypersplenism co-existed. All data were analyzed retrospectively.

RESULTS

No intraoperative death occurred, blood routine analysis improved (P < 0.05), the blood flow velocity (P < 0.05) and diameter (P < 0.05) of the left portal vein (LPV) significantly increased, the esophageal and gastric varices significantly relieved in 34 patients (P < 0.05), and better effects of earlier operations were demonstrated than the delayed ones (P < 0.05). During the period of follow-up from 6 to 64 months, the overall patency rate was 85.7% and the younger the age the better of the effect.

CONCLUSION

Rex-bypass shunt combined with pericardial devascularization is a safe and effective procedure for prehepatic portal hypertension caused by CTPV.

Case report of a modified Meso-Rex bypass as a treatment technique for late-onset portal vein cavernous transformation with portal hypertension after adult deceased-donor liver transplantation

RATIONALE

Portal vein thrombosis is a complication after liver transplantation and cavernous transformation of the portal vein (CTPV) is a result of portal vein thrombosis, with symptoms of portal hypertension revealed by an enhanced CT scan. Meso-Rex bypass is an artificial shunt connecting the left portal vein to the superior mesenteric vein and is mainly used for idiopathic cavernomas. This technique is also used for post-transplant portal vein thrombosis in pediatric patients thereby bypassing obstructed sites of the extrahepatic portal vein. Here we report about an adult patient who was treated by connecting the cystic part of the portal vein to the splenic vein instead of the superior mesenteric vein.

PATIENTS CONCERN

An adult male patient with post-liver transplantation portal vein cavernous transformation suffered from hypersplenism and elevated hepatic enzymes.

DIAGNOSIS

The last follow up revealed irregular and obvious hypersplenism, and splenomegaly had occurred, while an enhanced CT scan revealed serious esophagogastric varices and CTPV in addition to occluded right and common PV trunks.

INTERVENTION

The patient was treated by connecting the cystic part of the portal vein to the splenic vein instead of the superior mesenteric vein.

OUTCOME

After the operation, a satisfactory velocity was confirmed 1 month postoperatively and the shunt still remained patent at the 6-month postoperation follow-up.

LESSONS

A Meso-Rex bypass intervention connecting the left portal vein to the splenic vein instead of the superior mesenteric vein after liver transplantation in an adult patient with right and common portal vein occlusions has been successfully performed as an alternative approach.

Portal hypertension in children: High-risk varices, primary prophylaxis and consequences of bleeding

BACKGROUND & AIMS

Primary prophylaxis of bleeding is debated for children with portal hypertension because of the limited number of studies on its safety and efficacy, the lack of a known endoscopic pattern carrying a high-risk of bleeding for all causes, and the assumption that the mortality of a first bleed is low. We report our experience with these issues.

METHODS

From 1989 to 2014, we managed 1300 children with portal hypertension. Endoscopic features were recorded; high-risk varices were defined as: grade 3 esophageal varices, grade 2 varices with red wale markings, or gastric varices. Two hundred forty-six children bled spontaneously and 182 underwent primary prophylaxis. The results of primary prophylaxis were reviewed as well as bleed-free survival, overall survival and life-threatening complications of bleeding.

RESULTS

High-risk varices were found in 96% of children who bled spontaneously and in 11% of children who did not bleed without primary prophylaxis (p<0.001), regardless of the cause of portal hypertension. Life-threatening complications of bleeding were recorded in 19% of children with cirrhosis and high-risk varices who bled spontaneously. Ten-year probabilities of bleed-free survival after primary prophylaxis in children with high-risk varices were 96% and 72% for non-cirrhotic causes and cirrhosis respectively. Ten-year probabilities of overall survival after primary prophylaxis were 100% and 93% in children with non-cirrhotic causes and cirrhosis respectively.

CONCLUSION

In children with portal hypertension, bleeding is linked to the high-risk endoscopic pattern reported here. Primary prophylaxis of bleeding based on this pattern is fairly effective and safe.

LAY SUMMARY

In children with liver disease, the risk of bleeding from varices in the esophagus is linked to their large size, the presence of congestion on their surface and their expansion into the stomach but not to the child's age nor to the cause of portal hypertension. Prevention of the first bleed in children with high-risk varices can be achieved by surgery or endoscopic treatment, and decreases mortality and morbidity.

Portal Vein Thrombosis: Recent Advance

Portal vein thrombosis is a life-threatening vascular disorder of the liver. In this chapter, I will review the recent advance regarding the epidemiology, etiology, management, and prognosis of portal vein thrombosis.

Usefulness of a recanalized umbilical vein for vascular reconstruction in pediatric hepatic surgery

PURPOSE

Pediatric surgeons currently engage in various abdominal vascular surgeries, which sometimes require vascular conduits or grafts. Herein, we report our experience with patients undergoing vascular reconstruction using a recanalized umbilical vein (rUV) and their long-term outcome.

METHOD

Five patients with extrahepatic portal vein obstruction (EHPVO) underwent mesenterico-/porto-left portal vein (PV) bypass surgery using a short rUV conduit with an interposition vein graft. A sixth neonate with a huge hepatic tumor underwent PV reconstruction with anastomosis of rUV to the proximal PV stump following right hepatectomy with partial PV resection. A seventh patient underwent living donor liver transplantation for recurrent hepatoblastoma. The hepatic inferior vena cava (IVC) was resected because of tumor involvement and reconstructed by transposition of the infrahepatic IVC and interposition of rUV obtained from the donor liver graft.

RESULTS

Sufficient flow through rUV was achieved and maintained in all patients without any complications during follow-up (0.7-6.9 years). Esophageal varices, splenomegaly, and other laboratory test abnormalities because of portal hypertension disappeared after surgery in patients with EHPVO.

CONCLUSION

Our experience confirmed the usefulness and long-term patency of rUV as an entry to the intrahepatic PV and as a free vascular graft to reconstruct PV or IVC.

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.

CONCLUSION

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

Background

The 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.

Methods

This 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.

Results

The 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.

Conclusions

This procedure could be used safely and effectively to treat selected patients with portal hypertension secondary to extrahepatic portal vein obstruction.

Clinical Management of Chronic Portal/Mesenteric Vein Thrombosis: The Surgeon's Point of View

BACKGROUND

Bleeding from esophageal varices is a life-threatening complication of chronic portal hypertension (PH), occuring in 15% of patients with a mortality rate between 20 and 35%.

METHODS

Based on a literature review and personal experience in the therapy of PH, we recommend a therapy strategy for the secondary prophylaxis of variceal bleeding in PH.

RESULTS

The main causes for PH in western countries are alcoholic/viral liver cirrhosis and extrahepatic portal/mesenteric vein occlusion, mainly caused by myeloproliferative neoplasms or hypercoagulability syndromes. The primary therapy is medical; however, when recurrent bleeding occurs, a definitive therapy is required. In the case of parenchymal decompensation, liver transplantation is the causal therapy, but in case of good hepatic reserve or without underlying liver disease, a portal decompressive therapy is necessary. Transjugular intrahepatic portosystemic shunt has achieved a widespread acceptance, although evidence is comparable with or better for surgical shunting procedures in patients with good liver function. The type of surgical shunt should be chosen depending on the patent veins of the portovenous system and the personal expertise.

CONCLUSION

The therapy decision should be based on liver function, morphology of the portovenous system, and imminent liver transplantation and should be made by an interdisciplinary team of gastroenterologists, interventional radiologists, and visceral surgeons.

Pancreatitis and portal vein thrombosis in children: the chicken or the egg causality dilemma

BACKGROUND

The association of pancreatitis and portal vein thrombosis (PVT) is extremely rare in children. We report on 3 cases which suggest that there may be a causal relation between the two.

METHODS

Clinical characteristics and evolution of 3 children with this particular condition were analyzed retrospectively. In this group of patients, the strategy consisted in opting for early surgical decompression of the portal hypertension, which was followed by a favorable outcome, not only in terms of complications related to the portal hypertension but also of a contemporaneous spontaneous regression of the concurrent pancreatic disease, in absence of any other specific management of the latter problem.

RESULTS AND CONCLUSIONS

Combined PVT and pancreatitis is exceptional in children. Although this series is small, it provides insight and some evidence that the pancreatic disease might be secondary to the cavernomatous transformation of the regional venous system. More interestingly, it suggests that the appropriate management strategy should be to rapidly relieve portal hypertension after resolution of the acute phase of pancreatitis.

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

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

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

Background

Meso-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/Methods

We 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.

Results

Preoperative 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).

Conclusions

Partial splenectomy and splenic vein autografting in MRB surgery can successfully resolve prehepatic portal hypertension and hypersplenism in children.