Non-cirrhotic portal hypertension versus idiopathic portal hypertension

Portal hypertension occurs in a number of disorders other than cirrhosis and they are collectively called non-cirrhotic portal hypertension (NCPH). The common causes of NCPH include idiopathic portal hypertension (IPH), non-cirrhotic portal fibrosis (NCPF) and extrahepatic portal venous thrombosis (EHPVT). Other causes include schistosomiasis, hepatic venous outflow tract obstruction, veno-occlusive disease and congenital hepatic fibrosis. Patients with IPH and EHPVT present with upper gastrointestinal bleeding, splenomegaly, ascites after gastrointestinal bleeding, features of hypersplenism, growth retardation and jaundice due to portal biliopathy. The diagnosis is usually made by abdominal ultrasound, upper gastrointestinal endoscopy, normal liver function tests and normal liver histology. Variceal bleeding in NCPH has lower mortality as compared with cirrhosis because of better liver functions in NCPH. Treatment for NCPH includes primary prophylaxis for variceal bleeding and prevention of repeat bleeding using drugs like beta-blockers, endoscopic sclerotherapy and endoscopic band ligation of varices. In patients with uncontrolled variceal bleeding or symptomatic hypersplenism, porto-systemic shunt surgery or splenectomy are required.     

Management of portal hypertension based on portal hemodynamics

Portal hypertension is most commonly caused by chronic liver disease. As liver damage progresses, portal pressure gradually elevates and hemodynamics of the portal system gradually change. In normal liver, venous returns from visceral organs join the portal trunk and flow into the liver (hepatopetal blood flow). As portal pressure increases due to liver damage, congestion of some veins of the visceral organ occurs (blood flow to and from). Finally, the direction of some veins (the left gastric vein in particular) of the visceral organ change (hepatofugal blood flow) and develop as collateral veins (portosystemic shunt) to reduce portal pressure. Therefore, esophagogastric varices serve as drainage veins for the portal venous system to reduce the portal pressure. In chronic liver disease, as intrahepatic vascular resistance is increased (backward flow theory) and collateral veins develop, adequate portal hypertension is required to maintain portal flow into the liver through an increase of blood flow into the portal venous system (forward flow theory). Splanchnic and systemic arterial vasodilatations increase the blood flow into the portal venous system (hyperdynamic state) and lead to portal hypertension and collateral formation. Hyperdynamic state, especially around the spleen, is detected in patients with portal hypertension. The spleen is a regulatory organ that maintains portal flow into the liver. In this review, surgical treatment, interventional radiology, endoscopic treatment, and pharmacotherapy for portal hypertension (esophagogastric varices in particular) are described based on the portal hemodynamics using schema.     

门静脉高压患者门静脉压力与血流动力学的相关性研究

目的 探讨门静脉高压患者门静脉血流动力学的变化特点及其与门静脉压力的相互关系。方法 采用彩色多普勒超声对４１例肝硬化门静脉高压患者（Ｃｈｉｌｄ Ａ、Ｂ级３１例、Ｃ级１０例）于手术前检测门静脉（ＰＶ）、脾静脉（ＳＶ）和肠系膜上静脉（ＳＭＶ）的内径和血流速度，再计算出相关的面积和血流量；于手术时对３１例ＣｈｉｌｄＡ十Ｂ级患者直接测量门静脉压力。３２例健康人和２６例慢性乙型肝炎患者（慢肝组）作为对照。结累 门静脉高压两组患者ＰＶ、ＳＶ和ＳＭＶ内径（ｃｍ）分别为１．５１和１．５２、１．３２和１．３４及１．１５和１．１５较慢肝组和正常组明显增宽，ｒ分别为１．３１和１．１６、０．９６和０．７９及０．９１和０．８２（Ｐ＜０．０１）；血流速度较正常组和慢肝组明显减慢（Ｐ＜０．０１）；门静脉高压Ｃ级组门静脉血流速度（ｃｍ／ｓ）为４．６５较门静脉高压Ａ十Ｂ级组（６．４２）明显减慢（Ｐ＜０．０１），而两组 ＳＶ和 ＳＭＶ的血流速度则差异无显著意义（Ｐ＞０．０５）；门静脉高压 Ａ＋Ｂ级组三条静脉的血流量明显大于正常组和慢肝组（Ｐ＜０．０１或Ｐ＜０．０５）；门静脉高压Ｃ级组门静脉血流量明显小于Ａ十Ｂ级组（Ｐ＜０．０１）；而ＳＶ和ＳＭＶ的血流     

Captopril reduces portal pressure effectively in portal hypertensive patients with low portal venous velocity

Background The effect of an angiotensin II blockade in lowering the portal pressure in patients with liver cirrhosis and portal hypertension is controversial. This prospective study was undertaken to evaluate the portal hypotensive effect of captopril compared to that of propranolol, and to determine the factors that contribute to a successful reduction in the portal pressure after longterm captopril administration in patients with liver cirrhosis.Methods The hepatic venous pressure gradient (HVPG) and portal venous velocity (PVV) were measured both before and 3 months after initiation of the administration of captopril (n = 29) or propranolol (n = 29) in cirrhotic patients with a variceal bleeding episode. Patients who showed a reduction in the HVPG of more than 20% of the baseline were defined as being responders.Results At 3 months, the mean reduction in the HVPG after captopril was less than that after propranolol (–3.0 ± 9.3% vs –28.5% ± 4.1%; P 0.05). However, of the 29 patients receiving captopril, 9 were classified as being responders. On multivariate analysis with parameters including age, cause, Child-Pugh score, HVPG, and PVV, only low PVV was found to be a significant independent factor for responders (PVV 12cm/s; odds ratio [OR], 12.2; 95% confidence interval [CI], 1.47–102.40) in the captopril group.Conclusions Longterm captopril administration reduces the portal pressure effectively in cirrhotic patients with a low PVV. This suggests that the reduction in portal pressure after captopril administration is a result of improved portal venous outflow brought about by a decrease in the intrahepatic vascular resistance. When the PVV is below 12cm/s, a captopril trial might be useful in preventing variceal bleeding in portal hypertensive patients.Part of this work has appeared in abstract form, in J Hepatol 2002;36 (Suppl 1):64     

EUS-guided portal vein catheterization: a promising novel approach for portal angiography and portal vein pressure measurements

BACKGROUND: Portal vein (PV) pressure measurements can provide valuable information for the management of patients with liver disease and portal hypertension. OBJECTIVE: To evaluate the feasibility and the safety of EUS-guided PV catheterization and pressure measurements in a porcine model. SETTING: Acute and survival experiments on five 50-kg pigs. DESIGN AND INTERVENTIONS: Intrahepatic PV was punctured under EUS guidance by using a 19-gauge FNA needle. A 0.035-inch guidewire was advanced through the needle into the PV. The needle was withdrawn. A 5.5F ERCP catheter was advanced over the guidewire into the PV and then connected to a pressure monitor. Continuous PV measurements were obtained for an hour. Afterward, the catheter was removed, and the animals were observed for 30 minutes. Three animals were then immediately euthanized for a necropsy. The other two animals were observed for two weeks and then were euthanized. MAIN OUTCOME MEASUREMENTS: The ability to perform EUS-guided PV catheterization and pressure measurement without complications. RESULTS: PV catheterization, angiography, and pressure measurements were performed without any problems or complications. There were no changes in vital signs and hemodynamic parameters during PV catheterizations, angiography, pressure measurements, and catheter removal. Survival experiments did not demonstrate any change in animal condition, behavior, or eating habits after the procedure. A necropsy in all animals revealed no active bleeding, and no damage to the liver, other intra-abdominal organs, or blood vessels. LIMITATIONS: No validation of measured PV pressure was made. CONCLUSIONS: EUS-guided PV catheterization is feasible, safe, and can be used for portal angiography and pressure measurements.     

Extrahepatic portal vein aneurysm associated with a tortuous portal vein

Portal vein aneurysm is rare and its etiology is controversial. A case of extrahepatic portal vein aneurysm associated with an unusually tortuous portal vein is described. Real-time ultrasonography showed anechoic masslike lesions at the porta hepatis communicating with the superior mesenteric vein and intrahepatic portal branches. This suggested the presence of two saccular portal vein aneurysms, 27 x 21 mm and 21 x 13 mm in size. Magnetic resonance imaging and portal venography confirmed the portal vein aneurysms and an unusually tortuous portal vein curving caudally between them. The liver was histologically normal and there was no evidence of portal hypertension. It is speculated that these portal vein aneurysms may have been congenital and that the associated tortuous portal vein might have been secondary to hemodynamic changes in the portal venous system.     

Non-cirrhotic portal hypertension

A chronic increase of the portal venous pressure is not only a sequel of liver cirrhosis. There is a large group of different diseases leading to "non-cirrhotic portal hypertension". Clinical presentation, diagnosis and treatment are discussed. The discrimination between cirrhotic and non-cirrhotic portal hypertension is important for the understanding of differences in clinical signs and course of the diseases, however.     

Non-cirrhotic portal fibrosis

Non-cirrhotic portal hypertension (NCPH) comprises of diseases having an increase in portal pressure (PP) due to intraheptic or prehepatic lesions, in the absence of cirrhosis. The lesions are generally vascular, either in the portal vein, its branches or in the perisinusoidal area. Because the wedged hepatic venous pressure (WHVP) is near normal, measurement of intravariceal or intrasplenic pressure is needed to assess portal pressure. The majority of the diseases included in the category of NCPH are well characterized disease entities where portal hypertension (PHT) is a late manifestation and hence, these are not discussed. Two diseases which present only with features of PHT and are common in developing countries are NCPF and extra-hepatic portal vein obstruction (EHPVO). Non-cirrhotic portal fibrosis is a syndrome of obscure etiology, characterized by 'Obliterative portovenopathy' leading to PHT, massive splenomegaly, repeated well tolerated episodes of variceal bleeding and anemia in young adults from low socio-economic strata of life. The hepatic parenchymal functions are nearly normal. Jaundice, ascites and hepatic encephalopathy are rare. Management of variceal bleeding remains the main concern as nearly 85% of patients with NCPF present with variceal bleeding. Endoscopic variceal ligation or sclerotherapy are equally effective in about 90-95% of the patients. Gastric varices are seen in about 25% patients and a bleed from them can be managed with cyanoacrylate glue injection or surgery. Other indications for surgery include failure of endoscopic therapy to control acute bleed and symptomatic hypersplenism. The prognosis of patients with NCPF is good and 5-years survival rates in patients in whom variceal bleeding can be controlled is about > 95%.     

Noncirrhotic portal hypertension

Portal hypertension is characterized by an increase in portal pressure (>10 mm Hg) and could be a result of cirrhosis of the liver or noncirrhotic diseases. Noncirrhotic portal hypertension (NCPH), as it generally is termed, is a heterogeneous group of diseases that is due to intrahepatic or extrahepatic etiologies. In general, the lesions in NCPH are vascular in nature and can be classified based on the site of resistance to blood flow. Noncirrhotic portal fibrosis and extrahepatic portal vein obstruction are two diseases that are common in developing countries; they most often present only with features of portal hypertension and not of parenchymal dysfunction. These are described in detail.     

Extrahepatic aneurysm of the portal venous system and portal hypertension

Portal venous aneurysm (PVA) is a rare condition characterized by dilatation of the portal venous system. PVA manifestation of symptoms is varied and depends on the aneurysm size, location and related-complications, such as thrombosis. While the majority of reported cases of PVA are attributed to portal hypertension, very little is known about the condition’s pathophysiology and clinical management remains a challenge. Here, we describe a 67-year-old woman who presented with complaint of dyspepsia and without a significant medical history, for whom PVA was incidentally diagnosed. The initial upper abdominal ultrasound revealed marked dilatation of the main portal vein, and subsequent contrast-enhanced computed tomography with angiography revealed a large aneurysm arising from the extrahepatic troncus portion of the portal vein, as well as gastroesophageal varices. A conservative approach using beta-blocker therapy was chosen. The patient was followed-up for 60 mo, during which time the asymptomatic status was unaltered and the PVA remained stable.     

胰源性与特发性门脉高压症的临床特点分析

目的探讨PPH与IPH的临床特点,加深对二者的认识,提高临床医师的诊治水平。方法对18例PPH与36例IPH患者的临床资料作一回顾分析。结果二者的肝脏形态、功能正常,病毒学指标阴性,超声检查脾静脉迂曲扩张,脾肿大;PPH患者超声检查门静脉正常,胰腺可见炎症、肿瘤、囊肿等表现;IPH患者门静脉及肠系膜上静脉迂曲扩张,但胰腺方面无异常。IPH患者汇管区纤维组织增生和炎性细胞浸润但无肝硬化改变而PPH患者肝脏组织学正常。结论临床中发现肝脏形态、功能正常,病毒学指标阴性,以门脉高压为主要表现而无肝硬化改变的患者,应考虑IPH与PPH的可能。进一步行超声检查门脉系统及胰腺情况,可进一步区分二者。     

Measurement of portal vascular resistance in patients with portal hypertension

Portal vascular resistance was measured percutaneously in 60 patients with chronic liver disease and in 5 control subjects. The portal vascular resistance (PVR) was calculated, using the following equation, from the portal blood flow (QPV), portal venous pressure (PPV), and hepatic venous pressure (PHV): PVR = (PPV - PHV)/QPV. The portal blood flow was measured using an ultrasonic Doppler duplex system, and the portal venous and hepatic venous pressures were measured using percutaneous transhepatic catheterization and venous catheterization, respectively. The wedged hepatic venous pressure was measured by occluding the hepatic venous branch using a balloon catheter. The portal vascular resistance was 0.25 +/- 0.13 mmHg X ml-1 X min X kg body weight (mean +/- SD, n = 5) in the control group, 0.64 +/- 0.29 mmHg X ml-1 X min X kg body wt (n = 13) in the chronic active hepatitis group, 1.34 +/- 0.79 mmHg X ml-1 X min X kg body wt (n = 30) in the cirrhosis group, and 0.85 +/- 0.69 mmHg X ml-1 X min X kg body wt (n = 13) in the idiopathic portal hypertension group.