Review article: the pathophysiology and pharmacological treatment of portal hypertension

The role of Transjugular Intrahepatic Portosystemic Stent-Shunt (TIPSS) in the management of variceal hemorrhage

BACKGROUND

Variceal bleeding in cirrhosis represents a lethal complication of their disease. In the last 20 years, management of AVH has improved greatly with reduction in mortality from 43% in 1980 to 15% in 2000.

AIM

Advances in endoscopic therapy, pharmacologic agents including vasoconstrictor therapy and antibiotics have played a large part in improving outcomes, but the role of Transjugular Intrahepatic Portosystemic Stent-Shunt (TIPSS) remains controversial, which this review will cover.

METHODS

MEDLINE search for the following terms was performed to July 2011: variceal hemorrhage, portal hypertension, cirrhosis, transjugular intrahepatic portosystemic stent-shunt (TIPSS), PTFE, covered stents. Where possible randomized controlled studies were used for this review, although uncontrolled studies were also included if they made a significant contribution to the literature.

RESULTS

Literature used for the present study was selected from a total of 252 publications and abstracts from meetings.

RESULTS

TIPSS has been used as a salvage therapy after initial medical and endoscopic therapy for the bleed given its high success rate in arresting uncontrolled variceal bleeding. The recent trial by Garcia- Pagan et al. suggested beneficial effects of an earlier covered TIPSS in those at high risk of treatment failure (Childs C and those who are Childs B with active bleeding).

CONCLUSIONS

TIPSS can reduce failure to control bleeding and rebleeding as well as mortality with no increase in the risk of hepatic encephalopathy.This needs to be confirmed in further trials. However, it is clear that prevention of rebleeding is the key to improved outcomes following a variceal bleed.

Deletion of inducible nitric oxide synthase decreases mesenteric vascular responsiveness in portal hypertensive mice

The effects of pre-hepatic portal hypertension were examined on the responsiveness of aorta and mesenteric artery from wild-type, inducible nitric oxide synthase knockout (iNOS-KO) and endothelial nitric oxide synthase knockout (eNOS-KO) mice. Mice were sham-operated or made portal hypertensive by creating a calibrated portal vein stenosis. Acetylcholine produced marked relaxations in phenylephrine (10 microM) contracted aorta and mesenteric artery from wild-type and iNOS-KO, both sham and portal hypertensive, but relaxations were abolished in vessels from eNOS-KO mice. There were no significant differences between sham and portal hypertensive animals within groups in the effects of acetylcholine. The potency of KCl was significantly increased in aorta and mesenteric artery from eNOS-KO mice. The maximum contraction to the alpha(1)-adrenoceptor agonist phenylephrine was significantly increased in aorta from eNOS-KO, as compared with wild-type mice. There were no significant differences between sham and portal hypertensive animals within each group in contractions of aorta to KCl or phenylephrine. However, in mesenteric artery, although portal hypertension did not change responsiveness in wild-type or eNOS-KO as compared to sham animals, the potency of phenylephrine was significantly reduced in portal hypertensive iNOS-KO mice as compared to shams. Hence, portal hypertension as compared to sham operation did not affect responses to vasoconstrictors in mouse aorta, but in mouse mesenteric artery portal hypertension affected vascular responses in iNOS-KO mice, suggesting that iNOS is involved in the mesenteric vascular response to portal vein ligation.

Acute and chronic effects of isosorbide-5-mononitrate administration on effective renal plasma flow and the renin-aldosterone system in cirrhotic patients

BACKGROUND AND AIMS

Isosorbide-5-mononitrate (ISMO) has been shown to be effective in reducing the risk of variceal bleeding in patients with cirrhosis. However, recent studies have suggested that this drug compromises renal function. The present study was conducted to assess the acute and chronic effects of ISMO on effective renal plasma flow (ERPF) and the renin-aldosterone profile in cirrhotic patients.

METHODS

Fifteen cirrhotic patients were included in the present study. The mean arterial pressure (MAP), heart rate (HR), serum renin concentration (SR), ERPF and plasma aldosterone concentration (PA) were checked before ISMO treatment (baseline study), after a single oral dose of 20 mg ISMO (acute effect study) and after 3 weeks of ISMO treatment (chronic effect study).

RESULTS

Our data showed that the oral administration of a single dose (20 mg) of ISMO to cirrhotic patients was associated with significant decreases in ERPF (from 405.18 to 369.06 mL/min) and MAP (from 93.26 to 86.40 mmHg), and increases in HR (from 65.53 to 70.06 beats/min), SR (from 24.15 to 54.41 pg/mL), and PA (from 105.1 to 148.7 pg/mL). However, no significant changes were observed in HR, MAP, PA, SR, or ERPF after 3 weeks of ISMO treatment when compared with the baseline study.

CONCLUSIONS

The administration of ISMO causes a decrease in ERPF in cirrhotic patients and its use in patients with renal impairment should be considered cautiously.

Transjugular intrahepatic portosystemic shunts (TIPS) in children

The transjugular intrahepatic portosystemic shunt procedure is an accepted treatment for adults with complications of portal hypertension. We performed a retrospective review of all pediatric TIPS placements performed at the University of California, San Francisco between 1990 and 1996. Twelve procedures were attempted in nine children, with a mean age (+/- SD) of 9.4 +/- 3.9 years (range, 5 to 15 years) and a mean weight of 31 +/- 18 kg (range, 16 to 70 kg). The indications for TIPS placement were portal hypertension complicated by chronic variceal hemorrhage not controlled with sclerotherapy (n = 7) and hypersplenism with thrombocytopenia (n = 2). TIPS placement was successfully completed initially in seven of nine (78%) patients. Unfavorable vascular anatomy was the cause of failure in two cases. The seven patients who underwent successful TIPS placement were followed up for an average of 136 days (range, 1 to 800 days); two still have patent shunts, three underwent liver transplantation, one had a splenorenal shunt after stenosis, and one died of underlying liver disease. Variceal bleeding was controlled in four of five patients who successfully underwent TIPS placement. Shunt occlusion occurred in four patients; patency was restored by transjugular shunt revision in three, and a splenorenal shunt was performed in one.

Successful use of a transjugular intrahepatic portosystemic stent shunt to control severe refractory oesophageal variceal haemorrhage in a poor risk patient

This report describes a 44 year old man with a severe gastrointestinal haemorrhage from oesophageal varices. Bleeding could not be controlled with conservative therapy and sclerotherapy. He was successfully treated with a radiologically guided transjugular intrahepatic stent shunt at a time when his condition was too poor to attempt an open surgical procedure.

Extrahepatic manifestations of alcoholic liver disease

Many of the extrahepatic manifestations of alcoholic liver disease are not specific and can be seen in other forms of cirrhosis and with alcohol abuse. Features that are more common or more florid in patients with alcoholic liver disease have been discussed in this chapter. Alcoholic liver disease results in changes in many systems in the body and it is important that these are recognized and treated where appropriate.