Liver Disease: Portal Hypertension



Liver Disease: Portal Hypertension


Jeffrey L. Kaufman



Henry Norman is a 60-year-old man who goes to the emergency department because of intermittent vomiting of bright red blood over the previous 4 hours. For several days, he has not felt well, but he has not seen a doctor in over a year. His bowel movements have been normal in consistency, and both stool and urine have had normal color. He felt weak and slightly dizzy when moving around his house before the vomiting started. After vomiting, he felt so weakened that he could not get up to go to the bathroom to vomit again. He has no history of peptic ulcer disease. He has smoked 1 to 1.5 packs per day for years. For most of his working life, he has drunk a fifth of vodka every 2 days or consumed two six-packs of beer after work. He had jaundice once in his youth; a physician attributed it to hepatitis. He is a metal fabricator and has not missed work because of accidents or binge drinking; he has never had a drunk driving violation. His father was said to be alcoholic and died of liver failure at age 57. His siblings are alive and well, and none of them drinks alcohol.

Mr. Norman is a thin man who appears chronically ill. His vital signs are as follows: respiratory rate, 24 breaths per minute; supine pulse rate, 142 beats per minute; supine blood pressure, 80/45 mm Hg; and body temperature is normal. The muscles of his arms and temporal fossae appear wasted, his sclerae are mildly icteric, and there are prominent telangiectases over the nose and cheeks. The chest and cardiac examination are normal, but the abdominal examination reveals mild tympany. The liver edge is firm and is at the right costal margin. There is no visceral tenderness to palpation. The stool is dark, tarry, and guaiac positive. The genitalia are those of a normal man, but the testes are atrophic. His femoral pulses are 2+, but popliteal and pedal pulses are absent. His fingers reveal yellow staining of the right index and middle fingernails, and he is right-handed. He has no asterixis. He is unable to produce a urine sample.



What are the key findings of the initial evaluation and treatment of Mr. Norman?

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Mr. Norman’s history indicates a recent and perhaps ongoing hemorrhage. Acute blood loss is indicated by the history and vital signs, which are best explained by significant hypovolemia. A priority is to resuscitate him by placing large-bore intravenous lines and rapidly infusing isotonic saline solution. Blood is drawn for typing and cross-matching. Additional tests include a complete blood count, platelet count, clotting studies (prothrombin time and partial thromboplastin time), and determination of electrolytes, blood urea nitrogen, and creatinine levels. Because of his history, liver function should be studied, including determination of albumin, total protein, bilirubin, alkaline phosphatase, aspartate transaminase, and alanine transaminase. The amylase level should also be checked.



What are the end points for volume infusion?

View Answer

The pulse rate, blood pressure, and urine formation should be evaluated. If the ability to urinate is in doubt, a Foley catheter should be placed to guide resuscitation. With complete resuscitation, his blood pressure will rise to whatever is his normal, probably a systolic above 120 mm Hg; the heart rate will drop, probably to below 100 beats per minute; and his urine output will be more than 30 to 50 mL per hour. He would undoubtedly have orthostatic hypotension on admission to the emergency department, and this would disappear with full resuscitation. Note that he may manifest a tachycardia because of anemia.



What is the role of vasopressors in this patient?

View Answer

Mr. Norman should not be treated with vasopressors because the hypovolemia is caused by hemorrhage; the shock is therefore treated with volume resuscitation, including blood transfusion when cross-matched blood is available.

Mr. Norman responds to infusion of 1.5 L saline: his pulse decreases to 115 beats per minute, and his blood pressure increases to 122/75 mm Hg. A nasogastric tube is passed, and lavage with warm saline partially clears clots and liquid blood with repeated rinses. Some of the rinses appear stained with bile.



What is the differential diagnosis for this patient?

View Answer

The most likely diagnosis is gastric or duodenal ulceration with bleeding. Other possibilities include gastritis with bleeding, portal hypertension with esophageal varices that have hemorrhaged, gastric variceal bleeding from portal hypertension (portal hypertensive gastropathy), bleeding from gastric varices as a result of splenic vein thrombosis, gastric or duodenal neoplasm with extrahepatic portal obstruction, Mallory-Weiss tear with hemorrhage, esophagitis with bleeding, and a myeloproliferative disorder with sclerosis of the portal system (1). Underlying carcinomatosis, stomach, liver, esophageal, or even small bowel, can also occur. End-stage liver disease with varices can also occur in the context of hepatitis.

Despite the patient’s history of alcohol consumption, peptic ulcer disease remains highest on the list because it accounts for one half to two thirds of cases of upper gastrointestinal (GI) bleeding. Gastritis accounts for another 15% of cases (2). Helicobacter pylori as a causative agent should be considered in the differential diagnosis.

Mr. Norman’s initial laboratory tests show the following results: hematocrit, 21%; platelet count, 55,000 per mL; sodium, 147 mEq per L; potassium, 3.7 mEq per L; chloride, 101 mEq per L; CO2, normal; blood urea nitrogen, 35 mg per dL; creatinine, 1.8 mg per dL; prothrombin time, 16 seconds (international normalized ratio [INR], 1.4); partial thromboplastin time, 44 seconds. The chest radiograph is normal. He continues to retch and vomit blood.



What diagnostic study is performed next?

View Answer

Upper GI endoscopy should be performed as soon as possible.

Mr. Norman is given 3 U of blood. His blood pressure stabilizes at 120/75 mm Hg, his pulse is maintained at 75 to 85 beats per minute, and his urine volume increases. He undergoes upper GI endoscopy, which reveals active bleeding from large esophageal varices.



What therapeutic options does the endoscopist consider?

View Answer

Endoscopic sclerotherapy should be performed if possible. The technique of sclerotherapy is to visualize the varices directly and to inject a sclerosant in and around them. As early as 1939, Crafoord considered using specially modified rigid esophagoscopes to inject esophageal varices with material that would cause them to scar and thrombose (3). The procedure did not become prominent because of its technical difficulty in comparison with shunting, but when fiberoptic endoscopes became clinically available in the 1970s, the procedure was revived. Because of its ease, most centers used sclerotherapy as the main procedure for early control of bleeding varices, especially in poor-risk patients (4).

The agents available for sclerotherapy in the United States is ethanolamine oleate. The procedure is successful in the initial control of bleeding varices in 80% to 90% of patients, in combination with other measures for medical management. In patients with acute bleeding, such as Mr. Norman, technical success depends on a clear view of the site of hemorrhage without interference from bleeding sites or persistent blood in the gastroesophageal lumen. Bleeding from gastric varices is more difficult to control with sclerotherapy because the upper stomach cannot be fixed in position for injection and because there are more veins that can bleed. Gastropathy from portal hypertension, including submucosal hyperemia, cannot be treated with sclerotherapy (5). The outcome is influenced by the Child classification of the patient at the time of sclerotherapy (6). An alternative surgical procedure, early portacaval shunting, has produced better results in the short- and long-term management of people with bleeding varices than has sclerotherapy (7). Additional studies favorably compare esophageal transection with sclerotherapy for control of acute bleeding (8).



What causes esophageal varices?

View Answer

In normal conditions, blood flows through the portal veins under low pressure (less than 10 mm Hg), which is consistent with the low resistance in the portal circulation of the liver. Significant increases in portal venous blood flow can be accommodated (e.g., during digestion) without an increase in portal venous pressure. In a diseased liver, with alteration of the microscopic portal architecture, obstruction to portal venous flow leads to elevation of portal venous pressure. The physiologic response to this rise in pressure is the formation of alternative channels for blood flow from the intestine to the central venous system, which bypass the liver altogether. These varices occur in the retroperitoneum, along the esophagus and stomach, around the anal canal, and around the umbilicus. Patients with symptoms of portal hypertension have portal venous pressures typically higher than 20 mm Hg, sometimes higher than 40 mm Hg.



What causes portal hypertension?

View Answer

The causation of portal hypertension is complex. Fibrosis of the liver, regeneration of liver nodules, and hepatocyte swelling all lead to distortion of portal architecture. The cause of rapid swings in portal pressure is uncertain. In North America and Europe, the most common cause of portal hypertension is alcoholic liver disease, or Laënnec’s cirrhosis. Worldwide, extrahepatic obstruction and fibrosis from schistosomiasis (Bilharzia) are the leading causes. Other causes of portal hypertension include portal or splenic vein thrombosis, which can be spontaneous or iatrogenic (e.g., use of umbilical vein catheters in neonatal intensive care units was a significant cause in the past); hepatic vein or vena cava obstruction (Budd-Chiari syndrome); hypersplenism with secondary portal hypertension caused by massive increases in portal vein blood flow (the liver architecture is normal but overwhelmed).



Which findings on initial history and physical examination suggest that portal hypertension with cirrhosis is the cause of bleeding?

View Answer

Alcohol abuse is common in the general population; practitioners should therefore check for warning signs by asking each patient about the quantity of alcohol used, binge drinking if any, and any societal adverse events such as being away from work or being arrested for drunk driving (9). Often, the most important history for the quantity of alcohol consumption comes from the patient’s family. Almost always associated with alcohol abuse is smoking. The physical examination often shows a general loss of muscle mass, and wasting can be severe in the end-stage patient. The liver feels firm and is often enlarged below the costal margin. Ascites may be present, although it may be difficult to differentiate fluid in the abdomen from mesenteric adiposity combined with muscle laxity. Spider angiomata over the chest and upper back can occur, as can gynecomastia. Testicular atrophy is common. There are no direct signs of portal engorgement other than the rare appearance of caput medusa from periumbilical collateral venous channels.



How are patients with portal hypertension classified in terms of prognosis?

View Answer

Child classified patients with alcoholic cirrhosis in terms of the expected morbidity and mortality from surgery for portal hypertension (2). The original intent was to stratify outcomes on the basis of a worst-case analysis. This classification was later modified by Pugh (2) to provide a general classification of the severity of disease. It describes the degree of liver damage in terms of protein synthetic function and ability to process digestive products (Table 17.1). A patient’s classification is based on the worst criterion. For example, a patient who has fixed ascites but all other factors in the B group range is still placed in group C.








TABLE 17.1. Child-Pugh Classification of Patients with Cirrhosis

































Liver Function or Patient’s Status


Group A


Group B


Group C


Bilirubin (mg/dL)


<2


2-3


>3


Albumin (g/dL)


>3.5


3-3.5


<3


Ascites


None


Some (easily controlled)


Fixed


Encephalopathy


None


Minimal


Significant


Nutritional status


Normal


Adequate


Poor (muscle wasting prominent)


No single test assesses liver function overall in a manner analogous to the creatinine clearance for renal function or ejection fraction for cardiac function. Other tests that describe liver function include prothrombin time as a measure of synthetic function and the bromsulphalein clearance test as a measure of the ability to process products of digestion (10). A cofactor in the prognosis of these patients is alcoholic hepatitis as established by liver biopsy. Biopsy is not routinely performed for patients with portal hypertension, but when tissue is obtained, the architectural changes in the liver and the prominence of Mallory bodies correlate with the outcome of surgery (11).



Why do varices bleed?

View Answer

The specific reason varices that have been stable for years suddenly hemorrhage is unknown. Portal pressure varies significantly over the day, especially with changes in the degree of inflammation of the liver. Other factors include esophageal or gastric erosion over varices. A prospective study of the predictors of bleeding from extant varices indicated that dominant risk factors are Child class, size of varices, and any abnormal markings over the varices (red wale markings) (12). Other factors that correlated with bleeding in other studies include the location of varices, other markings over the varices (cherry-red spots and hematocystic spots), color of varices, esophagitis, ascites, and prothrombin time.

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Sep 23, 2016 | Posted by in UROLOGY | Comments Off on Liver Disease: Portal Hypertension

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