variceal bleeding

variceal bleeding
Field	Gastroenterology, Hepatology

variceal bleeding. It is a life-threatening complication of portal hypertension, most commonly arising from dilated submucosal veins in the esophagus or stomach. This condition represents a major cause of morbidity and mortality in patients with advanced liver cirrhosis, often necessitating urgent intervention in a critical care setting. The rupture of these fragile vessels leads to significant hematemesis and can precipitate hypovolemic shock.

Definition and pathophysiology

The condition is defined as hemorrhage from distended, tortuous veins that develop as portosystemic collaterals due to elevated pressure in the portal venous system. The primary driver is portal hypertension, frequently a consequence of architectural distortion from liver cirrhosis. According to the Frank-Starling law, increased venous pressure leads to vessel wall tension and dilation, particularly in the lower esophagus where the azygos vein system provides a collateral pathway. The pathophysiological cascade involves endothelial dysfunction, increased production of vasodilators like nitric oxide, and a hyperdynamic circulatory state, ultimately weakening the vascular wall and predisposing to rupture.

Causes and risk factors

The principal cause is portal hypertension, which itself is most often caused by liver cirrhosis from etiologies such as chronic hepatitis B, chronic hepatitis C, and alcohol-related liver disease. Other causes include portal vein thrombosis, schistosomiasis, and Budd-Chiari syndrome. Major risk factors for a bleeding episode include the size of the varices, the presence of red wale marks on endoscopic examination, and the severity of underlying liver disease as classified by the Child-Pugh score or the Model for End-Stage Liver Disease (MELD). A history of previous hemorrhage significantly increases the risk of rebleeding.

Clinical presentation and diagnosis

Patients typically present with abrupt, painless, and large-volume hematemesis, which may be accompanied by melena and signs of hypovolemic shock such as tachycardia and hypotension. Mental status changes may occur due to hepatic encephalopathy precipitated by the blood load in the gastrointestinal tract. The initial diagnosis is often clinical, but confirmation and therapeutic intervention are achieved via esophagogastroduodenoscopy, which allows direct visualization and grading of varices. Ancillary tests include complete blood count to assess anemia, coagulation studies like the international normalized ratio, and imaging such as computed tomography angiography to evaluate the portal venous system.

Management and treatment

Acute management is a multidisciplinary effort involving gastroenterology, hepatology, and critical care medicine. Initial resuscitation follows Advanced Trauma Life Support principles, with cautious volume replacement to avoid exacerbating portal pressure. Pharmacologic therapy begins immediately with intravenous vasopressin analogues like terlipressin or somatostatin analogues such as octreotide. Endoscopic therapy is the cornerstone, with endoscopic variceal ligation being preferred for esophageal varices and endoscopic sclerotherapy or cyanoacrylate injection for gastric varices. For uncontrolled bleeding, transjugular intrahepatic portosystemic shunt placement or, rarely, surgical portosystemic shunt surgery may be necessary.

Prognosis and complications

The prognosis is guarded, with in-hospital mortality historically ranging from 15-20%, heavily dependent on the severity of the underlying liver disease. The Baveno criteria are often used to define treatment failure and predict outcomes. Common immediate complications include rebleeding, aspiration pneumonia, and worsening ascites. The procedure of transjugular intrahepatic portosystemic shunt itself carries risks of hepatic encephalopathy and shunt stenosis. Long-term, patients remain at risk for hepatorenal syndrome and progressive liver failure.

Prevention

Primary prevention in patients with cirrhosis involves screening endoscopy and prophylactic endoscopic variceal ligation for large varices, coupled with non-selective beta blocker therapy like nadolol or propranolol. Secondary prevention after an initial bleed is critical and combines repeated endoscopic variceal ligation sessions with continued beta blocker use. Management of the underlying liver disease, including abstinence from alcohol and treatment of hepatitis B or hepatitis C with agents like direct-acting antivirals, is fundamental. In select cases, liver transplantation remains the definitive preventive intervention.

Category:Medical emergencies Category:Digestive system diseases