| الوصف: |
Over the last 20 years, there have been significant advances in the management of portal hypertension, with the introduction of drug therapy and the transjugular intrahepatic portosystemic stent-shunt (TIPSS). There are two aims of this thesis: 1. To study the haemodynamic effects of two novel vasocative agents on the portal and systemic circulations, and assess suitability for use in controlled clinical trials involving patients at risk of variceal bleeding: a. Carvedilol, a vasodilating non-cardioselective beta-blocker with α1 antagonism. The acute and chronic haemodynamic effects of this agent will be studied, with particular attention paid to patient tolerability. b. Losartan, an angiotensin II receptor antagonist. The chronic effects of this agent will be studied in patients with well compensated cirrhosis. 2. TIPSS has been used extensively in the management of portal hypertension, particularly variceal bleeding. Two studies will be presented in this thesis aimed at answering the following questions: a. Is TIPSS effective for the management of gastric variceal bleeding? This study will compare the efficacy of TIPPS for gastric and oesophageal variceal bleeding, and aim to correlate clinical outcomes with haemodynamic data. b. Is it necessary to continue portographic TIPSS surveillance indefinitely if variceal band ligation is combined with TIPSS for the prevention of oesophageal variceal rebleeding? This question will be explored in a randomised controlled trial comparing TIPSS alone with TIPSS plus variceal band ligation. This study will also address 2 drawbacks of TIPSS, namely the need for long-term portographic to ensure TIPSS patency and hepatic encephalopathy. |
