Management of portal hypertension-related bleeding

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

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

Portal hypertension as immune mediate disease

CONTEXT

Portal Hypertension (PH) is a progressive complication due to chronic liver disease. In addition to pathophysiologic changes in the micro-circulation, in PH are established fibrous tissue (periportal fibrous septal) and regenerative hyperplastic nodules (from micro- to macro-nodules) promoting hepatic architectural distortion.

EVIDENCE ACQUISITION

A literature search of electronic databases was undertaken for the major studies published from 1981 to today. The databases searched were: PubMed, EMBASE, Orphanet, Midline and Cochrane Library. We used the keywords: "portal hypertension, children, immune system, endocrine system, liver fibrosis".

RESULTS

It is believed that PH results from three "phenotype": ischemia-reperfusion, involving nervous system (NS); edema and oxidative damage, involving immune system; inflammation and angiogenesis, involving endocrine system. However, its exact cause still underdiagnosed and unknown.

CONCLUSIONS

PH is a dynamic and potentially reversible process. Researchers have tried to demonstrate mechanisms underlying PH and its related-complications. This review focuses on the current knowledge regarding the pathogenesis, and immune, endocrine-metabolic factors of disease. The strong positive association between immune system and development of PH could be efficient to identify non-invasive markers of disease, to modify prognosis of PH, and to development and application of specific and individual anti-inflammatory therapy.

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.

Management of portal hypertension in children

Management of portal hypertension in children has evolved over the past several decades. Portal hypertension can result from intrahepatic or extrahepatic causes. Management should be tailored to the child based on the etiology of the portal hypertension and on the functionality of the liver. The most serious complication of portal hypertension is gastroesophageal variceal bleeding, which has a mortality of up to 30%. Initial treatment of bleeding focuses on stabilizing the patient. Further treatment measures may include endoscopic, medical, or surgical interventions as appropriate for the child, depending on the cause of the portal hypertension. β-Blockers have not been proven to effectively prevent primary or secondary variceal bleeding in children. Sclerotherapy and variceal band ligation can be used to stop active bleeding and can prevent bleeding from occurring. Transjugular intrahepatic portosystemic shunts and surgical shunts may be reserved for those who are not candidates for transplant or have refractory bleeding despite medical or endoscopic treatment.

Clinical analysis of pericardial devascularization by preserving vagus trunks in 42 patients with portal hypertension

Pericardial devascularization (PD) is less of a burden and provides better bleeding control to patients compared to shunt procedures, and so has been widely used in portal hypertension in China. However, because the vagus trunks are interrupted during surgery, patients easily suffer from postoperative stomach adynamia. Based on our understanding from autopsy of the path of vagus trunks along the distal oesophagus, we designed the operative procedure of PD by preserving vagus trunks (PDPVT) to treat portal hypertension. Between May 1991 and January 2003, patients with portal hypertension were treated surgically using PDPVT (n = 42), single PD (n = 32), or PD with pyloroplasty (PD+PP; n = 16). Operative mortality was 2.4% in the PDPVT group and 6.3% in both the PD and PD+PP groups (p > 0.05). The postoperative rebleeding rate was 9.5% in the PDPVT group and 12.5% in both the PD and PD+PP groups (p > 0.05). There were no differences in operative time and estimated blood loss between the three groups (p > 0.05). The recovery time for gastroenteric function was shorter with PDPVT (mean, 3.5 days) than with PD (mean, 5.7 days) and PD+PP (mean, 4.2 days; p < 0.02). Incidences of early satiety and enterogastric reflux were significantly lower in the PDPVT group (both 4.8%) than in the PD group (46.9% and 18.8%) and PD+PP group (12.5% and 100%; p < 0.005). Incidences of retention of gastric juice, diarrhoea and late gallstones were 12.5%, 15.6% and 7.1%, respectively, in the PD group, and 12.5%, 18.8% and 6.3%, respectively, in the PD+PP group, but none of these were observed in the PDPVT group. Since it preserves vagus trunks, PDPVT can maintain normal stomach dynamics and physiological function of hepatobiliary and gut systems better than PD and PD+PP, thus reducing incidences of postoperative complications. Thus, PDPVT is superior to PD and PD+PP in the treatment of portal hypertension.