Portal Hypertension

Gastroesophageal Varices

• bleeding from gastroesophageal varices is responsible for one out of three deaths from cirrhosis

1. Pathogenesis
• veins in the submucosal plexus of the esophagus and proximal stomach are part of the collateral network that diverts high pressure portal flow from the coronary vein to the azygos system
• varices do not develop until portal pressure exceeds IVC pressure by 10 mm Hg
• as the submucosal veins dilate, the overlying mucosa may erode
• rupture has been ascribed to 2 factors: 1) increased tension within the varix, and 2) ulceration secondary to acid reflux and esophagitis
• bleeding occurs in only 33% of cirrhotic patients with varices


2. Treatment of Acute Hemorrhage
1. Resuscitation
• first priority is the restoration of circulating blood volume
• need multiple large-bore IVs
• initial resuscitation should be with isotonic crystalloid solutions; blood should be typed and crossmatched for 6 units
• if the prothrombin time is prolonged, then FFP should be part of the resuscitation fluids
• platelets are necessary only if the platelet count is less than 50,000


2. Diagnosis
• upper endoscopy is mandatory after the patient is stabilized to establish the cause of bleeding
• in cirrhotic patients, varices are the source of bleeding in ~ 50% of patients
• other common sources of bleeding include portal hypertensive gastropathy, duodenal ulcer, Mallory-Weiss tear, gastric varices


3. Control of Bleeding
1. Endoscopic Therapy
• rubber band ligation is the most commonly used modality to control an acute bleeding episode
• successful in 85% of patients with esophageal varices but is generally unsuccessful in patients with gastric varices
• sclerotherapy may be attempted if band ligation is not available
• after resuscitation, vasoactive drugs should be started, and band ligation performed







2. Pharmacotherapy
• reduces variceal pressure by reducing variceal blood flow
• octreotide (somatostatin) may initially control the bleeding, but the combination of octreotide and band ligation is most effective at stopping acute bleeding
• octreotide has minimal adverse effects
• in severe cases, vasopressin can be used to reduce splanchnic blood flow
• vasopressin has many serious side effects, including hypertension, bradycardia, decreased cardiac output, and coronary vasoconstriction
• most of these side effects of vasopressin can be mitigated by the simultaneous infusion of nitroglycerin
• antibiotics reduce infections, decrease rebleeding, and improve survival


3. Balloon Tamponade
• major advantages of this device are its widespread availability and its high success rate in stopping bleeding (85%)
• major disadvantages include a high rebleeding rate after balloon deflation, patient discomfort, patient must be intubated, and many potentially lethal complications
• lethal complications include:
• esophageal perforation as a result of inflating the gastric balloon in the esophagus
• ischemic necrosis of the esophagus as a result of overinflating the esophageal balloon or leaving it inflated for too long (> 36 hrs)
• aspiration
• indications for use include:
• the lack of availability of endoscopic therapy
• exsanguinating bleeding preventing the use of endoscopy
• failed endoscopic and pharmacologic therapy
• because the rebleeding rate is high following balloon deflation, most patients will require definitive treatment (endoscopic therapy, TIPS, or surgery)



4. Transjugular Intrahepatic Portosystemic Shunt (TIPS)
• accomplishes portal decompression without an operation
• requires an experienced interventional radiologist
• a 10-mm expandable PTFE covered stent is placed between a hepatic vein and a major intrahepatic portal venous branch, creating the shunt
• success rate is 90% in acutely bleeding patients
• not recommended as initial therapy for acute variceal hemorrhage, but should be used only after endoscopic therapy and pharmacotherapy have failed to control the bleeding
• one clear indication for TIPS is as a short-term bridge to liver transplantation when endoscopic therapy has failed
• TIPS functions as a nonselective side-to-side shunt and so worsening of encephalopathy is a side effect
• shunt stenosis or occlusion occurs in 50% of patients within 1 year of TIPS insertion - in most cases, shunt patency can be reestablished by the interventional radiologist



5. Emergency Surgery
• reserved for situations when less invasive methods to stop bleeding are unsuccessful or not available
• the most common indications include failure of acute endoscopic therapy, gastric varices, or portal hypertensive gastropathy
• esophageal transection with a stapling device is quick and relatively simple, but rebleeding rates are high
• most commonly performed operation is the portacaval shunt
• mortality rate is ~ 25%


3. Prevention of Recurrent Hemorrhage
• once a patient has bled from varices, the likelihood of a repeat episode exceeds 70%



1. Pharmacotherapy
• nonselective beta-blockers (propranolol) reduce the risk of recurrent hemorrhage by about 20%
• combination therapy with a beta-blocker and long-acting nitrate (isosorbide) is even more effective
• no easily measured hemodynamic index to monitor therapy


2. Endoscopic Therapy
• variceal endoscopic banding is the most common method for prevention of recurrent hemorrhage
• the goal is to eradicate varices
• combination therapy with ligation and beta-blockers is most effective at preventing recurrent bleeding
• treatment failure resulting in rebleeding occurs in ~33% to 50% of patients
• should not be used in noncompliant patients and patients who live a long distance from advanced medical care


3. TIPS
• being increasingly used as definitive treatment
• major limitation has been the high rate of shunt stenosis or thrombosis (50%)
• stenosis from neointimal hyperplasia can often be fixed by balloon dilation
• PTFE covered stents have reduced the incidence of shunt stenosis and thrombosis
• ideal treatment for patients who need only short-term portal decompression (liver transplant candidates, patients with limited life expectancies)
• fewer rebleeding episodes after TIPS (19%) than endoscopic therapy (47%)
• also effectively treats intractable ascites
• encephalopathy is worsened
• liver failure is accelerated


4. Portosystemic Shunts
• most effective means of preventing recurrent hemorrhage in patients with portal hypertension
• procedures work by decompressing the high pressure portal venous system into the low pressure systemic venous system
• however, diversion of portal flow, which contains hepatotrophic hormones, nutrients, and cerebral toxins, is also responsible for the side effects of shunt procedures: encephalopathy and accelerated liver failure
• shunts may completely (nonselectively) or partially (selectively) divert portal flow


1. Nonselective Shunts
• completely divert portal flow and decompress the entire portal venous circulation
• primarily used in emergency settings when a TIPS cannot be performed or when a TIPS fails


1. End-to-Side Portocaval Shunt
• effective in preventing recurrent variceal bleeding
• since it does not decompress the hepatic sinusoids, this shunt does not alleviate ascites
• no increased survival over conventional medical management
• cause of death is related to accelerated liver failure



2. Side-to-Side Portocaval Shunt
• in addition to preventing recurrent bleeding, this shunt relieves medically intractable ascites



3. Interposition Shunts
• may be constructed with a synthetic graft or autogenous vein (internal jugular)
• most common varieties are the portocaval, mesocaval, and mesorenal
• mesocaval shunt is often selected if hepatic transplantation is being considered since dissection in the hepatic hilum is avoided
• a major disadvantage of synthetic interposition grafts is a high postoperative graft thrombosis rate
• encephalopathy and accelerated liver failure are side effects
• effectively relieves ascites



4. Conventional Splenorenal Shunt
• consists of anastomosing the proximal splenic vein to the renal vein
• splenectomy is also required and so this shunt has been advocated when hypersplenism causes severe thrombocytopenia or leukopenia
• since the smaller proximal splenic vein is used for the anastomosis, shunt thrombosis is rather frequent



2. Selective Shunts
• goal is to selectively decompress the portal venous system, maintaining some portal perfusion in the hope of minimizing encephalopathy and accelerated hepatic failure


1. Distal Splenorenal Shunt
• consists of an anastomosis between the distal end of the splenic vein to the side of the left renal vein
• also consists of ligation of the coronary and gastroepiploic veins
• result is to disconnect the superior mesenteric and gastrosplenic components of the portal venous system
• the gastrosplenic venous system is decompressed but the superior mesenteric system remains a high-pressure system, allowing portal perfusion of the liver
• 50% of patients lose portal flow within a year because the mesenteric system gradually collateralizes into the low pressure gastrosplenic system
• because sinusoidal and mesenteric hypertension remains, and important lymphatic channels are disrupted during dissection of the left renal vein, this shunt worsens ascites
• previous splenectomy and a small splenic vein (< 7 mm) are contraindications for this procedure
• as effective as nonselective shunts in preventing rebleeding
• associated with lower encephalopathy rates than nonselective shunts
• survival rates are similar between both types of shunt




3. Partial Shunts
• small diameter (<10 mm) interposition portocaval shunt combined with ligation of the coronary vein and other collaterals
• goal is the same as for selective shunts: decompression of varices while maintaining some hepatic portal perfusion
• less encephalopathy associated with partial shunts than with nonselective interposition shunts
• similar rebleeding and survival rates



5. Nonshunt Operations
1. Esophageal Transection
• goal is ablation of varices
• transection and reanastomosis of the esophagus is performed using the EEA stapling device
• not commonly done because of the high incidence of recurrent hemorrhage



2. Sugiura Procedure
• consists of esophageal transection, extensive esophagogastric devascularization, and splenectomy
• coronary vein and paraesophageal veins are preserved to discourage reformation of varices
• excellent results have been achieved in Japan



3. Splenectomy
• curative in cases of gastric varices caused by splenic vein thrombosis


4. Liver Transplantation
• only operation that cures the underlying liver disease as well as providing portal decompression
• purpose is treatment of end-stage liver disease, not variceal bleeding
• because of economic factors and a limited supply of donors, liver transplantation is not widely available