Previous studies exploring preoperative intrahepatic portal venous system to evaluate Rex shunt efficacy in pediatric cavernous transformation of the portal vein have yielded controversial results. To develop a novel postoperative intrahepatic portal venous system classification to predict long-term outcomes of Rex shunt in children with cavernous transformation of the portal vein. From October 2014 to February 2024, children with cavernous transformation of the portal vein who underwent Rex shunt were retrospectively analyzed. One week after Rex shunt, intrahepatic portal venous system were classified into types A-C using ultrasound based on the patency of the connection between the Rex vein and the right portal vein. These types were further subdivided into subtypes based on the Rex vein inner diameter. We compared spleen length, spleen thickness, and esophageal variceal grading before and one year after Rex shunt across these types, as well as the incidence of vascular complications one year after Rex shunt. The study included 160 children: 129 type A (124 type A1, 5 type A2), 25 type B (17 type B1, 8 B2), 6 type C1, with subtypes distinguished by an Rex vein inner diameter ≤ 4mm. Type A exhibited superior outcomes compared to types B and C, which had comparable results. Type A1 demonstrated the most significant benefits, with fewer complications and improved variceal grading, although splenic size reduction was similar to that of type B1. Type B1 outperformed type B2 in terms of complications, variceal grading, and splenic measurements, and surpassed type A2 in splenic length reduction and type C1 in variceal grading and splenic thickness reduction. The novel one-week postoperative intrahepatic portal venous system is effective to predict one-year postoperative outcomes of Rex shunt.

BackgroundExtrahepatic portal vein obstruction (EHPVO) is a leading cause of pediatric portal hypertension. While invasive portography remains the diagnostic gold standard, its risks highlight the need for non-invasive alternatives. This study aims to integrate ultrasound imaging features and serological markers to establish a machine learning model for noninvasive, simplified preoperative assessment of the portal system in pediatric patients with EHPVO. The model will serve as a reference for selecting optimal surgical strategies.MethodsA total of 103 pediatric EHPVO patients who underwent surgery were enrolled, including 81 Rex shunt and 22 Warren shunt cases. In the training set, the least absolute shrinkage and selection operator (LASSO) algorithm identified potential predictors. Five machine learning algorithms were employed for modeling. Model performance was evaluated through internal validation and external validation.ResultsBaseline characteristics showed no significant differences between training and validation sets. LASSO-selected features were used to construct five prediction models. The extreme gradient boosting (XGBoost) model outperformed the others. It achieved an area under the receiver operating characteristic curve (AUC) of 0.90 [95% confidence interval (CI): 0.79–0.99] on the training set and 0.75 (95% CI: 0.54–0.97) on the validation set. An online platform (https://rexshunt.shinyapps.io/rexorwarren/) was subsequently developed based on this optimal model.ConclusionsThis study established a predictive model combining serological markers and ultrasound parameters to preoperatively assess portal venous anatomy in pediatric EHPVO. The online tool provides a noninvasive, user-friendly solution to guide surgical strategy selection for children with EHPVO.

To explore the differences in efficacy and underlying reasons between the classic Rex shunt and the modified Rex shunt in treating extrahepatic portal vein obstruction (EHPVO) in children. This retrospective study compared 24 children with portal cavernomas treated at our hospital from July 2022 to March 2024. Twelve patients underwent the classic Rex shunt using an internal jugular vein as a bypass vein, whereas the other twelve patients received the modified Rex shunt involving an inferior mesenteric vein (IMV) to the left portal vein (LPV) shunt. This study compared the operative time, postoperative hospital stay, pre- and postoperative portal pressures, degree of postoperative portal pressure reduction, diameter and length of grafted vein, diameter of vascular anastomosis with the left portal vein, patency rate of the bypass vein, postoperative splenic shrinkage ratio, postoperative hypersplenism relief rate, and incidence of postoperative rebleeding between the two groups. There were no statistically significant differences in age at surgery, sex ratio, postoperative hospital stay, or follow-up duration between the two groups. The operative time for the classic Rex shunt was notably longer than that for the modified Rex shunt (P < 0.001). There were no statistically significant differences in pre- or postoperative portal pressure, degree of postoperative portal pressure reduction, length of the grafted vein, or diameter of the anastomosis with the LPV between the two groups. However, the diameter of the internal jugular vein was notably larger than that of the IMV (P < 0.001). The diameter of the bypass vein in the patency group was notably greater than that in the occluded group (P < 0.001). Compared with the modified Rex shunt group, the classic Rex shunt group had a greater postoperative hypersplenism relief rate, but this difference was not statistically significant. The patency rate of the bypass vein and the postoperative splenic shrinkage ratio were markedly greater in the classic Rex shunt group than in the modified Rex shunt group (P < 0.05). The classic Rex shunt was more effective based on a higher patency rate and greater relief of splenomegaly and hypersplenism.

BackgroundCavernous transformation of the portal vein (CTPV) is one of the significant pathogenic factors of prehepatic portal hypertension in children. The Rex shunt, by reconstructing an intrahepatic portal venous pathway, not only effectively reduces portal pressure and restores physiological hepatic blood flow, but also promotes normal growth and development, making it the treatment of choice for CTPV. In contrast, traditional non-selective shunting procedures primarily alleviate symptoms of portal hypertension without restoring hepatic perfusion, thereby compromising growth potential. For patients unsuitable for the Rex shunt, living donor liver transplantation provides a definitive cure. Overall, both the Rex shunt and liver transplantation improve long-term outcomes in children with CTPV by reestablishing physiological portal circulation.PurposeThis study aims to summarize the clinical efficacy and institutional experience in the management of pediatric portal vein cavernous transformation.MethodsA retrospective analysis was conducted on seven children with portal vein cavernous transformation treated at the Department of Pediatric Surgery, First Affiliated Hospital of Xinjiang Medical University, between December 2021 and March 2025. The cohort included four boys and three girls, with ages ranging from 5 years and 10 months to 12 years. All patients had a history of esophagogastric variceal bleeding and hypersplenism. Preoperative evaluations included portal vein color Doppler ultrasonography, abdominal computed tomography angiography (CTA) to assess the portal venous system anatomy and blood flow dynamics. Following a rigorous assessment, six patients underwent living donor liver transplantation, and one patient underwent Rex shunt surgery.ResultsAll seven surgeries were successfully completed. During a follow-up period ranging from 3 to 42 months, no episodes of gastrointestinal bleeding were observed in any patient. Among the six patients who underwent liver transplantation, no cases of graft rejection, arterial complications, or biliary complications were reported. Postoperatively, all seven patients demonstrated a significant reduction in portal vein pressure and improvement in pancytopenia compared to preoperative values (P < 0.05).Of the six transplant recipients, three required portal vein reconstruction using allogeneic vascular grafts to establish continuity between the graft portal vein and the recipient superior mesenteric vein; in two cases, direct anastomosis was performed between the graft portal vein and a suitable segment of the recipient portal vein. The patient who underwent Rex shunt surgery received autologous inferior mesenteric vein grafting to reconstruct the portal pathway. Three transplant recipients developed portal vein anastomotic stenosis postoperatively, all of which were successfully managed with a single session of portal venography combined with balloon angioplasty.ConclusionsWhile the Rex shunt remains the gold standard for the treatment of portal vein cavernous transformation, living donor liver transplantation provides a viable alternative for patients unsuitable for Rex shunt reconstruction.

Meso-Rex procedure is the surgical treatment of choice for severe portal hypertension (PHT) secondary to extrahepatic portal vein obstruction (EHPVO). Our aim was to describe our initial experience using cryopreserved arterial allografts as an alternative shunting conduit. Retrospective review of patients with EHPVO who underwent a Meso-Rex procedure using cryopreserved arterial allografts between January 2023 and April 2024. Rex shunt surgery was performed in five of the eleven patients operatedfor EHPVO during this period. Arterial allografts were employed in four cases, with a mean age of 10 ± 1.2years. The mean conduit diameter and length was 9.25 ± 3.5 and 73.5 ± 11.5mm, respectively. With a mean follow-up of 16 ± 5months, all patients developed shunt thrombosis secondary to calcification. Shunt flow was reestablished exclusively with percutaneous transhepatic thrombectomy and stenting in one patient. The remaining three patients required a revision surgery to remove the calcified graft: two Rex shunts were salvaged with polytetrafluoroethylene (PTFE) conduits and one was converted to a mesocaval shunt. All shunts are patent 6.5 ± 2.2months after repermeabilization. Although the intended use of cryopreserved arterial grafts was to avoid comorbidities associated with harvesting autologous conduits, they are not an alternative to the classic Meso-Rex procedure given the high thrombosis and reoperation rate secondary to shunt calcification.

Revisiting the place of surgical portal decompression for adults with noncirrhotic portal hypertension due to chronic extrahepatic portal vein obstruction: a scoping review.

Medium-to Long-term Outcomes of Rex Shunt in 105 Children With Extrahepatic Portal Vein Obstruction in China

Rex shunt is an optimal surgery for the treatment of extra-hepatic portal venous obstruction (EHPVO) in children. Anticoagulant therapy has been used to keep the patency of the bypass vein in the Rex shunt. This study was to investigate the effectiveness of anticoagulant therapy using heparin combined with Plavix in improving the prognosis and shunt patency of Rex shunt. From January 2010 to September 2019, 51 children with EHPVO underwent a portal cavernoma- Rex shunt. Based on whether using the anticoagulant therapy after the Rex shunt, all patients were divided into two groups: the anticoagulant group and the non-anticoagulant group. The diameter and flow velocity of the bypass vein were measured by the post-operative ultrasound, which was used to calculate the flow volume of the bypass vein (FV) and standard portal venous flow (SPVF). The bypass venous flow index (BVFI) was used to evaluate the ability of portal blood into the liver through the bypass vein after the Rex shunt, which was a ratio of FV to SPVF. The incidence of post-operative re-bleeding, the postoperative patency rate of the bypass vein, the remission rate of postoperative hypersplenism, the remission rate of postoperative esophagogastric varices and the BVFI were compared between the two groups. Of the 51 patients, 12 patients in the anticoagulant group were treated with heparin combined with Plavix after Rex shunt; 39 patients in the non-anticoagulant group were not treated with any anticoagulant therapy. 8 of 51 patients suffered from postoperative re-bleeding, of whom 6 patients with thrombosis of the bypass vein and 2 patients with anastomotic stenosis of the bypass vein. All 8 patients with re-bleeding belonged to the non-anticoagulant group. The remission rate of hypersplenism was no significant difference between the two groups after surgery (91% vs. 58%, P = 0.100). However, 3 patients without hypersplenism before surgery suffered from hypersplenism after surgery, who belonged to the non-anticoagulant group. There was no significant difference in the remission rate of esophagogastric varices (33% vs. 46%, P = 1.000). The BVFI of the anticoagulant group was significantly higher than that of the non-anticoagulant group (5.71 ± 5.89 vs. 1.1 ± 1.52, P = 0.003). Anticoagulant therapy using heparin combined with Plavix plays an important role in maintaining the patency of the bypass vein, which improved the portal blood flow into the liver through the bypass vein after the Rex shunt.

Limited data exist regarding outcome and morbidity associated with portosystemic shunts in the pediatric transplant population. Our study assesses the outcomes of pediatric patients who underwent a portosystemic shunt procedure, both with and without liver transplantation (LT). This study retrospectively reviewed the medical records of pediatric patients aged 0-19 years who underwent shunt placement between 2003 and 2017 at a tertiary care center. The analysis included cases of shunt placement with or without LT. A total of 13 pediatric patients were included in the study with median age of 8.8 years. Among the cases, 11 out of 13 (84.6%) underwent splenorenal shunt, 1 (7.7%) underwent a mesocaval shunt, and another 1 (7.7%) underwent a Modified Rex (mesoportal) shunt. Additionally, 5 out of 13 (38.5%) patients had LT, with 4 out of 5 (80.0%) receiving the transplant before shunt placement, and 1 out of 5 (20.0%) receiving it after shunt placement. Gastrointestinal bleeding resulting from portal hypertension was the indication in all cases. A total of 10 complications were reported in 5 patients; the most common complication was anemia in 3 (23.1%) patients. At the most recent follow-up visit, the shunts were functional without encephalopathy, and no deaths were reported. Shunt placement plays a crucial role in the management of patients with portal hypertension. Our study demonstrates favorable long-term outcomes in pediatric patients who underwent shunt placement. Long term shunt outcomes were similar and unremarkable in patients with LT and without LT.

To review our single-center surgical outcomes of redo operations after failed Rex shunt procedures. From September 2017 to October 2021, a total of 20 patients (11 males, 9 females; median age: 8.6 years) with Rex shunt occlusions were admitted to our hospital. Two of these patients were previously operated on in our hospital, and the remaining 18 were from other centers. All patients underwent repeat operations after detailed preoperative evaluations. Preoperative wedged hepatic vein portography (WHVP) was conducted for 18 patients. Thirteen patients exhibited well-developed Rex recessus and intrahepatic portal vein during WHPV examination, consistent with the intraoperative exploration results. Fifteen patients (75%, 15/20) underwent redo-Rex shunt, four underwent Warren shunt and one underwent devascularization surgery. During the redo-Rex shunt operations, the left internal jugular veins (IJV) were used as bypass grafts in 11 patients; the intra-abdominal veins were used in 4 patients. The patients were followed up for 12-59 months (mean, 24.8 months). After redo Rex shunts, the grafts were patent in 14 patients (93.3%, 14/15), but 1 graft had thrombosis (6.7%, 1/15). Three patients suffered from postoperative anastomotic stenosis, and all of the stenosis was relieved with balloon dilatations. After re-Rex shunts, esophageal varices and spleen size were substantially reduced, and the platelet count significantly increased. Postoperative graft thrombosis was found in 1 patient after Warren shunt (1/4, 25%), and there was no graft stenosis. Compared with Warren surgery, patients who underwent re-Rex shunt had a significantly higher rate of platelet increase. Redo-rex shunts can be finished in most patients with failed Rex shunts. Re-Rex shunt is a preferred surgical choice after a failed Rex shunt when a good bypass graft is available, and the surgical success rate can reach more than 90%. A suitable bypass graft is essential for a successful redo Rex shunt. Preoperative WHVP is recommended for the design of a redo surgical plan preoperatively.

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. 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. 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). 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.

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. 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: 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). 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.

Two-stage Liver Resection with Rex Shunt (Tr-Rex Procedure) to Augment Flow and Function Prior to Right Hemihepatectomy in an Adult with Main Portal Vein Occlusion

Abernethy malformation is a rare abnormality of the hepatic portal vein system with non-specific and diverse clinical manifestations. Here, we described a case of abernethy malformation with hepatopulmonary syndrome in a 10-year-old girl. On physical examination, cyanosed lips and acropachy could be found. Her oxygen saturation fluctuated at 89–94%, and the fasting blood ammonia was 98 umol/L. Furthermore, there were abnormalities in the imaging. The microbubble test with contrast echocardiography was positive. Computer tomography angiography (CTA) showed the splenic vein, and the superior mesenteric drained directly into the inferior vena cave after confluence. The same result was also observed in delayed splenic arteriography. Then, we discovered a tiny branch of the intrahepatic portal vein by the inferior vena cava balloon occlusion test, which could also show the confluence of the splenic vein and superior mesenteric vein with the inferior venacave. According to the evidence above, we concluded that the girl was a patient of type II abernethy malformation. For the severe dysplasia of the portal vein, the girl accepted partial ligation of portosystemic shunt and Rex shunt, which improved her oxygen saturation and exercise tolerance.

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. 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. There were 6 male and 5 female patients (median age, 58years) 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 90days of surgery. Two patients died of tumor recurrence with a patent RS at 13 and 29months, and 7 were recurrence free with a patent shunt with a follow-up of 1 to 37months (median, 15months). 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.

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

Use of the Rex Shunt in Adults for Left Portal Vein Reconstruction

BackgroundPortal vein thrombosis (PVT) after pediatric liver transplantation (LT) is a common but grave complication which could eventually result in life-threatening portal hypertension. A “Rex” shunt between the superior mesenteric vein and the Rex recess of the liver has been reported to be a treatment option for extrahepatic portal vein obstruction; however, its application to living donor liver transplantation (LDLT) is limited due to the availability of appropriate vein grafts. In this study, we retrospectively evaluated the effectiveness of Rex shunt as an option for the treatment of PVT after pediatric LDLT.Case ReportThree children underwent the Rex shunt for early (n=2) and late (n=1) PVT after LDLT using the greater saphenous vein (n=2) and the external iliac vein (n=1) from the parents who previously donated their livers.Two of the 3 children are free from symptoms with patent shunt grafts at 14 years after the procedures. One child died at 30 days after LDLT due to repeated episodes of PVT, which finally led to hepatic infarction.ConclusionsThe Rex shunt is feasible to treat PVT after LDLT. However, additional surgical insults to the living donor need further discussion.

P-125 REX SHUNT IN A DEVELOPING COUNTRY – IS IT POSSIBLE?

BACKGROUND: One of the most common causes of extrahepatic portal hypertension in children is portal vein thrombosis. The causes of this disease are different and, in most cases, remain unrecognized. Along with this, the mesoportal shunt (Rex shunt) proved itself and today is considered the gold standard to treat extrahepatic portal hypertension in children. The restoration of hepatopetal blood flow eliminates gastroesophageal bleeding, splenomegaly, hypersplenism, and many other complications. For the results of mesoportal shunt to be successful, several conditions must be met, one of which is the patency of the umbilical portion of the left portal vein. Despite the importance of preoperative diagnostics of the patency of this area, the most optimal instrumental research method has not yet been found.&#x0D; AIM: This literature review aims to highlight the main issues of extrahepatic portal hypertension etiopathogenesis, surgical treatment methods, and the most effective preoperative diagnostic methods to assess the patency of the left portal vein.&#x0D; RESULTS: The authors analyzed the sources of domestic and foreign literature on the etiology, pathogenesis of HSV in children, and laboratory and instrumental diagnostic methods to assess the patency of the PVI to plan the mesoportal shunting operation.&#x0D; CONCLUSIONS: Extrahepatic portal hypertension is a polyetiological disease with a possible hereditary predisposition to a thrombotic process under the influence of various triggers. The most common causes of portal vein thrombosis are omphalitis and umbilical vein catheterization in the neonatal period. Unfortunately, to date, none of the existing instrumental diagnostic methods can reliably answer the question about left portal vein patency. Due to the small number of works, the lack of a unified view on the problem of preoperative diagnosis of patients with extrahepatic portal hypertension, we could not reliably determine the specificity, sensitivity, and accuracy of each instrumental method. Therefore, we could not identify the gold standard method. Nevertheless, with further improvement of the methods for preoperative assessment of the left portal vein patency, surgeons will be more likely to predict the successful outcome of mesoportal shunting, which will generally affect the surgical treatment quality of extrahepatic portal hypertension in children.