Medical and surgical management of portal hypertension in children

Portal vein thrombosis: diagnosis, management, and endpoints for future clinical studies

Portal vein thrombosis (PVT) refers to the development of a non-malignant obstruction of the portal vein, its branches, its radicles, or a combination. This Review first provides a comprehensive overview of all aspects of PVT, namely the specifics of the portal venous system, the risk factors for PVT, the pathophysiology of portal hypertension in PVT, the interest in non-invasive tests, as well as therapeutic approaches including the effect of treating risk factors for PVT or cause of cirrhosis, anticoagulation, portal vein recanalisation by interventional radiology, and prevention and management of variceal bleeding in patients with PVT. Specific issues are also addressed including portal cholangiopathy, mesenteric ischaemia and intestinal necrosis, quality of life, fertility, contraception and pregnancy, and PVT in children. This Review will then present endpoints for future clinical studies in PVT, both in patients with and without cirrhosis, agreed by a large panel of experts through a Delphi consensus process. These endpoints include classification of portal vein thrombus extension, classification of PVT evolution, timing of assessment of PVT, and global endpoints for studies on PVT including clinical outcomes. These endpoints will help homogenise studies on PVT and thus facilitate reporting, comparison between studies, and validation of future studies and trials on PVT.

Pathophysiology of ascites: The importance of the intestine. A surgical contribution to the understanding of a medical problem

The understanding of the mechanisms for the development of ascites has evolved over the years, involving the liver, peritoneum, heart, and kidneys as key responsible for its formation. In this article, we review the pathophysiology of ascites formation, introducing the role of the intestine as a major responsible for ascites production through "a game changer" case.

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 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.

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.

Advances in the management of childhood portal hypertension

Portal hypertension is one of the most serious complications of childhood liver disease, and variceal bleeding is the most feared complication. Most portal hypertension results from cirrhosis but extra hepatic portal vein obstruction is the single commonest cause. Upper gastrointestinal endoscopy endoscopy remains necessary to diagnose gastro-esophageal varices. Families of children with portal hypertension should be provided with written instructions in case of gastrointestinal bleeding. Children with large varices should be considered for primary prophylaxis on a case-by-case basis. The preferred method is variceal band ligation. Children with acute bleeding should be admitted to hospital and treated with antibiotics and pharmacotherapy before urgent therapeutic endoscopy. All children who have bled should then receive secondary prophylaxis. The preferred method is variceal band ligation and as yet there is little evidence to support the use of β-blockers. Children with extrahepatic portal vein obstruction should be assessed for suitability of mesoportal bypass.

Evaluation of Rex Shunts

The purpose of the Rex shunt is to restore normal blood flow to a hemodynamically compromised liver that is otherwise normal. It has proven to be an effective treatment for children with extrahepatic portal vein thrombosis as in the case presented. The shunt allows blood from the superior mesenteric vein to bypass the obstructed extrahepatic portal vein and enter the liver through the still patent left portal vein. The operation is successful in more than 90% of patients. The name “Rex shunt” is derived from the location in the liver in which the shunt is placed, the area between segments three and four of the left lobe of the liver.

Perioperative strategies and thrombophilia in children with extrahepatic portal vein obstruction undergoing the meso-Rex bypass

BACKGROUND/PURPOSE

Extrahepatic portal vein obstruction (EHPVO) is an important cause of chronic portal hypertension in children. Although usually idiopathic in etiology, genetic and acquired thrombophilia have been implicated in EHPVO. Meso-Rex bypass is increasingly used to treat EHPVO in children.

OBJECTIVE

The objective of this study is to assess the relationship of postoperative anticoagulation strategies and thrombophilic risk factors to the development of bypass thrombosis following the meso-Rex bypass.

METHODS

Records of children who underwent meso-Rex bypass for EHPVO at a single institution from 1999 to 2009 were reviewed, and preoperative thrombophilia testing, perioperative anticoagulation strategies, and postoperative bypass patency based on imaging at last follow-up were examined.

RESULTS

Sixty-five children with EHPVO underwent a first time meso-Rex bypass during the study period, and 9 of 65 (14 %) developed bypass thrombosis. The use of warfarin in the postoperative period was more common among children with thrombosed shunts than among those with open shunts [63 % vs. 20 %; OR, 6.5 (95 % CI, 1.3-31.5), p = 0.022]. The contribution of genetic or acquired thrombophilia to shunt thrombosis was inconclusive given variability in testing.

CONCLUSIONS

Choice of anticoagulation following meso-Rex bypass may affect postoperative incidence of bypass thrombosis. Role of thrombophilic risk factors in the development of shunt thrombosis remains unclear.

Approach to a child with upper gastrointestinal bleeding

Upper gastrointestinal bleeding (UGIB) is a potentially life threatening medical emergency requiring an appropriate diagnostic and therapeutic approach. Therefore, the primary focus in a child with UGIB is resuscitation and stabilization followed by a diagnostic evaluation. The differential diagnosis of UGIB in children is determined by age and severity of bleed. In infants and toddlers mucosal bleed (gastritis and stress ulcers) is a common cause. In children above 2 y variceal bleeding due to Extra-Hepatic Portal Venous Obstruction (EHPVO) is the commonest cause of significant UGIB in developing countries as against peptic ulcer in the developed countries. Upper gastrointestinal endoscopy is the most accurate and useful diagnostic tool to evaluate UGIB in children. Parenteral vitamin K (infants, 1-2 mg/dose; children, 5-10 mg) and parenteral Proton Pump Inhibitors (PPI's), should be administered empirically in case of a major UGIB. Octreotide infusion is useful in control of significant UGIB due to variceal hemorrhage. A temporarily placed, Sengstaken-Blakemore tube can be life saving if pharmacologic/ endoscopic methods fail to control variceal bleeding. Therapy in patients having mucosal bleed is directed at neutralization and/or prevention of gastric acid release; High dose Proton Pump Inhibitors (PPIs, Pantoprazole) are more efficacious than H2 receptor antagonists for this purpose.

Surgical management of portal hypertension in children

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

Pre- and postoperative imaging of the Rex shunt in children: what radiologists should know

OBJECTIVE

The objective of this article is to illustrate the imaging features of patients with extrahepatic portal venous obstruction who are evaluated before or after a Rex shunt surgery.

CONCLUSION

The Rex shunt is a potentially curative surgical procedure that reestablishes physiologic hepatopetal portal flow. It is typically accomplished by interposing a vascular conduit between the superior mesenteric vein to the still patent intrahepatic portal venous system. This procedure results in resolution of portal hypertension.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Progression of noncirrhotic portal hypertension in a pediatric population

BACKGROUND/OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

Surgery for portal hypertension in children

Management of children with portal hypertension has evolved considerably over the past decades. Development of physiologic shunts (meso-Rex bypass) and successful liver transplant has changed the paradigm of portal hypertension surgery. Children with pre-hepatic portal hypertension are investigated and, if suitable, candidates are offered the mesenteric-to-left portal vein bypass (meso-Rex) preemptively, before development of symptoms of portal hypertension. Aggressive medical management, endoscopic ligation of bleeding varices, and radiologically placed intrahepatic stents have greatly reduced the need for emergent surgical procedures. A larger number of surgical options offer a permanent solution for children with portal hypertension in the setting of well-compensated liver function. Portal hypertension in the setting of decompensated liver disease is managed medically (via endoscopy) or radiologically (via transjugular intrahepatic portosystemic shunt) with the aim to offer liver transplant as a permanent solution.

Growth impairment in children with extrahepatic portal vein obstruction is improved by mesenterico-left portal vein bypass

BACKGROUND

Extrahepatic portal vein obstruction (EHPVO) has been associated with growth impairment in children. We hypothesized that growth parameters improve after reversal of portal hypertension and restoration of mesenteric venous blood flow to the liver by the mesenterico-left portal vein bypass (MLPVB).

METHODS

A retrospective review of 45 children with idiopathic EHPVO who underwent MLPVB between 1997 and 2007 and had follow-up data for analysis was carried out. Growth was assessed using SD scores (z scores) for height, weight, and body mass index (BMI) at the time of operation and at early (5-12 months) and late (13-24 months) follow-up.

RESULTS

The mean height and weight of children with EHPVO was significantly lower than the general population before surgery. Mean BMI was also lower, although statistically insignificant. All parameters increased significantly after MLPVB as follows: height from -0.42 before surgery to -0.12 (P = .027) at 5 to 12 months and -0.14 (P = .026) at 13 to 24 months; weight from -0.49 before surgery to 0.03 (P < .001) at 5 to 12 months and 0.35 (P < .001) at 13 to 24 months; and BMI from -0.22 before surgery to 0.17 (P = .001) at 5 to 12 months and 0.48 (P < .001) at 13 to 24 months.

CONCLUSION

Restoration of portal blood flow to the liver by MLPVB improves growth in children with EHPVO.