Narrow-diameter portacaval shunts for management of variceal bleeding

The Liver and Vascular Surgery

The anesthesiologist may encounter patients with pre-exist ing liver disease who are scheduled to undergo surgery and anesthesia or may care for patients with postoperative liver dysfunction caused by various intraoperative events. A re view of pre-existing or intraoperative factors that can con tribute to liver dysfunction will enhance the clinician's abil ity to establish a differential diagnosis and course of clinical care. The clinician should become familiar with the prognos tic indicators of perioperative morbidity and mortality in the patient with pre-existing liver disease to carefully weigh the risks and benefits of proceeding with surgery and anesthe sia; the patient and the surgeon should be counseled accord ingly. The first section of this article, on liver dysfunction after vascular surgery, addresses various intraoperative fac tors that may contribute to postoperative hepatic dysfunc tion and reviews the impact of pre-existing liver disease on perioperative morbidity and mortality. Today, more patients undergo transjugular intrahepatic portosystemic shunt (TIPS) procedures than surgical portosystemic shunts. The introduction of liver transplantation into clinical medicine has also reduced surgical portosystemic shunts. The second section of this article, on current status of portosystemic shunts, reviews both surgically and radiographically placed shunts and their current role in caring for patients with portal hypertension.

Current role of surgery in portal hypertension

Treatment for portal hypertension (PHT) has evolved from surgery being the only option during the 1970s to the wide range of options currently available. Surgery has not vanished from the therapeutic armamentarium, but its role has changed and is constantly evolving. The present review primarily focuses on the role of surgery in tackling patients with PHT and varices with regard to the Indian scenario and also looks at its relevance, given the availability of a host of other therapeutic options.

Surgery for portal hypertension in children

Management of children with portal hypertension has evolved considerably over the past decades. Development of physiologic shunts (meso-Rex bypass) and successful liver transplant has changed the paradigm of portal hypertension surgery. Children with pre-hepatic portal hypertension are investigated and, if suitable, candidates are offered the mesenteric-to-left portal vein bypass (meso-Rex) preemptively, before development of symptoms of portal hypertension. Aggressive medical management, endoscopic ligation of bleeding varices, and radiologically placed intrahepatic stents have greatly reduced the need for emergent surgical procedures. A larger number of surgical options offer a permanent solution for children with portal hypertension in the setting of well-compensated liver function. Portal hypertension in the setting of decompensated liver disease is managed medically (via endoscopy) or radiologically (via transjugular intrahepatic portosystemic shunt) with the aim to offer liver transplant as a permanent solution.

Portale Hypertension

Während die Pathologie, die zur portalen Hypertension führt, im prähepatischen, hepatischen und posthepatischen venösen Gefäßbett liegen kann, machen die intrahepatischen Erkrankungen mit Abstand den Großteil aus. In unseren Breitengraden ist es die durch Alkoholabusus bedingte ethyltoxische Leberzirrhose, weltweit die durch Infektionen (HCV, HBV) bedingten Zirrhosen. Die chronische Hepatitis C mit ihren Komplikationen (Leberzellversagen, portale Hypertension und hepatozelluläres Karzinom) wird in den kommenden Jahren trotz moderner Therapieverfahren noch an Bedeutung gewinnen.

Portosystemic shunts versus endoscopic therapy for variceal rebleeding in patients with cirrhosis

BACKGROUND

Randomised clinical trials have compared portosystemic shunting procedures with endoscopic therapy for variceal haemorrhage, but there is no consensus as to which approach is preferable.

OBJECTIVES

To compare the effects of shunts (total surgical shunt (TS); distal spleno-renal shunts (DSRS) or transjugular intrahepatic porto-systemic shunts (TIPS) with endoscopic therapy (ET, sclerotherapy and/or banding) for prevention of variceal rebleeding in patients with cirrhosis.

SEARCH STRATEGY

The Cochrane Hepato-Biliary Group Controlled Trials Register, The Cochrane Library, MEDLINE, EMBASE, conference proceedings, and the references of identified trials were searched (last search February 2004). Researchers in the field and in industry were contacted.

SELECTION CRITERIA

Randomised clinical trials comparing TS, DSRS or TIPS with ET in patients who had recovered from a variceal haemorrhage and were known to be cirrhotic.

DATA COLLECTION AND ANALYSIS

Data were collected to allow intention-to-treat analysis where possible. For each outcome, a pooled estimate of treatment effect (log hazard ratio for time to outcome, Peto odds ratio for binary outcomes, and differences in means for continuous outcomes) across trials was calculated.

MAIN RESULTS

Twenty-two trials evaluating 1409 patients were included. All trials had problems of method. Shunt therapy compared with ET demonstrated significantly less rebleeding (OR 0.24, 95% CI 0.18 to 0.30) at the cost of significantly increased acute hepatic encephalopathy (OR 2.07, 95% CI 1.59 to 2.69) and chronic encephalopathy (OR 2.09, 95% CI 1.20 to 3.62). There were no significant differences regarding mortality (hazard ratio 1.00, 95% CI 0.82 to 1.21) and duration of in-patient stay (weighed mean difference 0.78 day, 95% CI -1.48 to 3.05). The proportion of patients with shunt occlusion or dysfunction was 3.1% (95% CI 0.4 to 10.7%) following TS (two trials), 7.8% (95% CI 3.8 to 13.9%) following DSRS (four trials), and 59% (range 18% to 72%) following TIPS (14 trials).

AUTHORS' CONCLUSIONS

All shunts resulted in a significantly lower rebleeding rate at the expense of a higher incidence of encephalopathy. TIPS was complicated by a high incidence of shunt dysfunction. No survival advantage was demonstrated with any shunt.

Portosystemic shunts versus endoscopic therapy for variceal rebleeding in patients with cirrhosis

BACKGROUND

Randomised clinical trials have compared portosystemic shunting procedures with endoscopic therapy for variceal haemorrhage, but there is no consensus as to which approach is preferable.

OBJECTIVES

To compare the effects of shunts (total surgical shunt (TS); distal spleno-renal shunts (DSRS) or transjugular intrahepatic porto-systemic shunts (TIPS) with endoscopic therapy (ET, sclerotherapy and/or banding) for prevention of variceal rebleeding in patients with cirrhosis.

SEARCH STRATEGY

The Cochrane Hepato-Biliary Group Controlled Trials Register, The Cochrane Library, MEDLINE, EMBASE, conference proceedings, and the references of identified trials were searched (last search February 2004). Researchers in the field and in industry were contacted.

SELECTION CRITERIA

Randomised clinical trials comparing TS, DSRS or TIPS with ET in patients who had recovered from a variceal haemorrhage and were known to be cirrhotic.

DATA COLLECTION AND ANALYSIS

Data were collected to allow intention-to-treat analysis where possible. For each outcome, a pooled estimate of treatment effect (log hazard ratio for time to outcome, Peto odds ratio for binary outcomes, and differences in means for continuous outcomes) across trials was calculated.

MAIN RESULTS

Twenty-two trials evaluating 1409 patients were included. All trials had problems of method. Shunt therapy compared with ET demonstrated significantly less rebleeding (OR 0.24, 95% CI 0.18 to 0.30) at the cost of significantly increased acute hepatic encephalopathy (OR 2.07, 95% CI 1.59 to 2.69) and chronic encephalopathy (OR 2.09, 95% CI 1.20 to 3.62). There were no significant differences regarding mortality (hazard ratio 1.00, 95% CI 0.82 to 1.21) and duration of in-patient stay (weighed mean difference 0.78 day, 95% CI -1.48 to 3.05). The proportion of patients with shunt occlusion or dysfunction was 3.1% (95% CI 0.4 to 10.7%) following TS (two trials), 7.8% (95% CI 3.8 to 13.9%) following DSRS (four trials), and 59% (range 18% to 72%) following TIPS (14 trials).

AUTHORS' CONCLUSIONS

All shunts resulted in a significantly lower rebleeding rate at the expense of a higher incidence of encephalopathy. TIPS was complicated by a high incidence of shunt dysfunction. No survival advantage was demonstrated with any shunt.

Portal hypertensive bleeding

Portal hypertension bleeding is a common and serious complication of cirrhosis. All patients with cirrhosis should undergo endoscopy and be evaluated for possible causes of current or future portal hypertensive bleeding. Possible causes of bleeding include esophageal varices, gastric varices, and PHG. Patients with esophageal varices at high risk of bleeding should be treated with nonselective beta-blockers for primary prevention of variceal hemorrhage. HVPG measurements represent the optimal way to monitor the success of pharmacologic therapy. EVL may be used in those with high-risk varices who do not tolerate beta-blockers. When active bleeding develops, simultaneous and coordinated attention must be given to hemodynamic resuscitation, prevention and treatment of complications, and active control of bleeding. In cases of acute esophageal variceal (Fig. 5) and PHG bleeding, terlipressin, somatostatin, or octreotide should be started. Endoscopic treatment is provided for those with bleeding esophageal varices. If first-line therapy fails, TIPS or surgery may need to be performed. Unlike esophageal variceal or PHG bleeding, there is no established optimal treatment for gastric variceal bleeding. Individual and specific treatment modalities for acute gastric variceal bleeding must be calculated carefully after considering side effects.

Salvage therapies for refractory variceal hemorrhage

Refractory variceal bleeding is defined as bleeding that continues through adequate pharmacologic and endoscopic therapy. In patients with end-stage liver disease, the only option for long-term salvage is liver transplantation. In patients with well-preserved liver function (Child's class A and class B-7), other salvage options such as surgical shunt, TIPS, and devascularization procedures can achieve good outcome. The long-term survival depends on the underlying liver disease, rather than on the variceal bleeding per se.

Review: surgical shunts and encephalopathy

Historically, surgical shunts have played an important role in the treatment of patients with portal hypertension associated with ascites and/or variceal esophageal bleeding. Today, in the era of liver transplantation most patients with end-stage liver disease and concomitant portal hypertension and associated problems are best treated by liver grafting. The successful introduction of transjugular intrahepatic portosystemic shunting (TIPS), performed by radiologists and gastroenterologists, provides a very effective alternative to surgical shunt procedures. One advantage of TIPS is that this procedure does not interfere with subsequent liver grafting. Today, surgical shunts have clearly lost ground to the less invasive TIPS procedure. Surgical shunts still maintain a role: as a salvage procedure in selected cases and in emergency situations. Surgical shunts are associated with a high rate of encephalopathy. In most cases selective surgical shunts should be preferred to nonselective surgical shunts. The role of partial surgical shunts versus selective surgical shunts remains to be determined. Hepatic encephalopathy is a common complication of all shunt procedures and is dependent on the shunt volume. Liver grafting is able to reverse encephalopathy because of a shunting procedure. In our institution, we prefer TIPS over surgical shunts as a bridging procedure before liver transplantation.

Small-diameter mesocaval shunts: a 10-year evaluation

The use of small-diameter portosystemic shunts for the treatment of bleeding esophageal varices caused by portal hypertension has emerged as an outgrowth of the development of polytetrafluoroethylene vascular grafts, which allow the use of a narrow lumen. We report our experience with this type of graft over a 10-year period. Thirty-three patients with good liver function (Child-Pugh class A) were electively operated. The average age of these patients was 45 years (range 17 to 71 years). Twenty-nine patients had liver cirrhosis, one had portal fibrosis, and three had idiopathic portal hypertension. Operative mortality was 3%, and the rebleeding rate was 15%. Postoperative encephalopathy was observed in 14 patients (11%), three of whom had grade III to IV encephalopathy. The remaining 11 patients, had mild encephalopathy that was easily controlled. Postoperative angiography showed shunt patency in 81% of the patients, reduction in portal vein diameter in 33% of the patients, and portal vein thrombosis in 6%. Good postoperative quality of life was observed in 63% of the patients. Survival according to the Kaplan-Meier actuarial method was 81% at 12 months, 56% at 60 months, and 36% at 10 years. These shunts are a good alternative for patients being considered for surgery in whom other portal blood flow preserving procedures (i.e., elective shunts, devascularization with esophageal transection) are not feasible.

Small-diameter portacaval H-graft shunt: a paradigm shift back to surgical shunting in the management of variceal bleeding in patients with preserved liver function

Small-diameter portacaval H-graft (SDPHG) shunts are partial portosystemic shunts that control variceal bleeding while preserving nutrient blood flow to the liver, minimizing postoperative encephalopathy and liver failure. Since July 1, 1997, we placed SDPHG shunts in 18 patients (age, 52.1 +/- 2.6 years; range, 35 to 72 years) with cirrhosis (Child's class A, B, and C in 6, 10, and 2 patients, respectively) and refractory variceal bleeding who were not candidates for transplantation. Ten procedures (55.6%) were urgent or emergent. SDPHG shunts effectively reduced the portacaval pressure gradient (18 +/- 3 v 5 +/- 2 mm Hg; P <.05). Surgical times (210 +/- 11 minutes), estimated blood losses (358.3 +/- 107.8 mL), transfusion requirements (0 transfusions in 10 patients; 55.6%; mean, 0.9 +/- 0.3 units), and postoperative hospitalization (7.7 +/- 1.0 days) were excellent. Surgical mortality (30 days) was 0%. During 14. 0 +/- 1.9 months (range, 1.1 to 29.1 months) of follow-up, 4 patients (22.2%) died, including both patients with Child's class C cirrhosis. The cumulative 1-year survival rate was 82.1% (Child's class A, B, and C, 83.3%, 90%, and 0%, respectively). Long-term survivors had significantly lower preoperative Child-Pugh scores compared with nonsurvivors (7.8 +/- 0.3 v 9.5 +/- 1.0; P <.05). Postoperative encephalopathy developed in 3 survivors (20%). Fifteen patients (83.3%) have not experienced rebleeding; shunt failure led to rebleeding in only 1 patient (5.6%). SDPHG shunt placement can be performed with low morbidity and surgical mortality. Nontransplantation candidates with Child's class A and B cirrhosis have excellent long-term survival with this safe, effective, and definitive treatment for refractory variceal bleeding.

Liver function and encephalopathy after partial vs direct side-to-side portacaval shunt: a prospective randomized clinical trial

BACKGROUND

The aim of this study was to determine, in a prospective randomized clinical trial, whether the partial portacaval shunt offers any advantage in terms of liver function and encephalopathy rate when compared with direct side-to-side direct portacaval shunt.

METHODS

Forty-six "good risk" patients with cirrhosis and with documented variceal hemorrhage were randomly assigned to either a partial shunt procedure (achieved by 10-mm diameter interposition portacaval H-graft) or direct small-diameter side-to-side portacaval anastomosis.

RESULTS

Operative mortality was zero in both groups. During the follow-up period, encephalopathy developed in 3 patients in the partial shunt group and 9 in the direct shunt group (P =.04). Kaplan-Meier analysis demonstrated that encephalopathy-free survival was significantly longer in the partial shunt group (P =.025). Direct shunt patients had significant hepatic functional deterioration postoperatively compared with the partial shunt group.

CONCLUSIONS

The partial portacaval shunt effectively controls variceal hemorrhage. Compared with direct side-to-side portacaval shunt, partial shunt preserves long-term hepatic function and minimizes postoperative encephalopathy. We conclude that the partial portacaval shunt is the preferred approach over direct shunts for patients with cirrhosis and with variceal bleeding.

Esophageal varices. II. TIPS (transjugular intrahepatic portosystemic shunt) and surgical therapy

The role of surgery in the prevention and treatment of variceal hemorrhage is reviewed. Types of available surgery, their physiologic basis, and literature supporting their use are discussed in the context of the natural history of variceal hemorrhage. The evolution of transjugular intrahepatic portosystemic shunt (TIPS) as a treatment modality for variceal hemorrhage is reviewed. The effects of TIPS on portal and systemic hemodynamics and clinical usefulness in the management of variceal hemorrhage are discussed. A treatment algorithm for the integrated use of the various treatments is provided.

Management of portal hypertension-related bleeding

Although endoscopic sclerotherapy and TIPS remain the primary therapeutic tools in management of acute variceal bleeding, surgical shunts must be considered for low-risk patients with bleeding. OLTx is the only definitive treatment for patients with end-stage liver disease and vascular decompensation. Furthermore, the current prospective multicenter randomized study, funded by the National Institutes of Health and Human Services, will help determine the role of DSRS versus TIPS in cirrhotic patients with good hepatic reserve. This is a necessity in a time in which organ shortages are ever-increasing because of a growing disparity between the number of patients listed for transplantation each year versus the number of suitable organ donors. The various surgical techniques should be applied in different situations based on patients' clinical status at the time of the bleed and whether they are considered candidates for liver transplantation.

Surgery in portal hypertension

The role of surgery in portal hypertension remains a topic of debate. For the past 100 years, various surgical procedures have been used to treat variceal bleeding, refractory ascites, and end-stage liver disease. The past decade has seen significant advances in pharmacotherapy, endoscopy, interventional radiology, and surgery for the management of patients with portal hypertension. Liver transplantation has come of age in the 1990s and is now an accepted therapy for patients with end-stage liver disease. The wide array of management options can complicate the decision making process and defines the need to evaluate these patients fully. Factors such as the aetiology and extent of liver disease, response to prior medical, endoscopic, and other interventional treatments, and possibility of future liver transplantation must be considered. This manuscript will review the history of surgical treatments of portal hypertension, describe the surgical procedures with their advantages and disadvantages, and evaluate their role in the elective and emergent settings.

The role of surgery in the treatment of portal hypertension

The role of surgery in the treatment of portal hypertension continues to evolve. Pharmacologic and endoscopic therapies are the primary treatment modalities for the prophylaxis and treatment of variceal bleeding and ascites. Failure of these therapies is the indication for invasive intervention such as TIPS, surgical shunt, or devascularization. Distal splenoreal shunting provides selective variceal decompression with less encephalopathy and accelerated hepatic failure than portal decompression. Liver transplantation remains the treatment of choice for patients with poor hepatic function.

Pathophysiology and treatment of variceal hemorrhage

Portal hypertension results from increases in portal flow and portal vascular resistance. Factors increasing portal blood flow are predominantly humoral. Resistance to portal flow has a fixed component due to distortion of the vasculature by cirrhotic nodules and a variable component that is related to vasoactive substances. Varices result from an increase in portal pressure. Factors predicting the risk of variceal bleeding include continued alcohol use, poor liver function, large varices, and red wale markings on varices at endoscopy. Octreotide is probably the drug of choice for pharmacologic management of bleeding esophageal varices. Propranolol has an established role in the prevention of variceal hemorrhage, and variceal band ligation may be the preferred endoscopic technique. Transjugular intrahepatic portosystemic shunts have emerged as an important treatment for patients in whom pharmacologic and endoscopic therapies have failed and are an effective bridge to liver transplantation.

Management of alcoholic cirrhosis of the liver

Patients with liver disease require skilled, complex management of the inevitable complications associated with hepatic dysfunction. Portal hypertension, a major consequence of cirrhosis of the liver, causes ascites and esophageal variceal hemorrhages. Many clinical and surgical treatment options are available to manage these complications; however, they often produce only temporary symptom control and may beget further morbidity. This article focuses on the etiology, complications, and treatment of alcoholic cirrhosis. Perioperative nursing care of patients with alcoholic cirrhosis is based on an understanding of normal hepatic functions and the systemic effects of cirrhosis.

Transjugular intrahepatic portosystemic shunt and liver transplantation

Transjugular intrahepatic portosystemic stent shunting (TIPSS) appears to be an attractive, nonsurgical procedure to overcome complications of end-stage liver disease. During the period August 1992 to February 1995, 23 adults who had previously undergone TIPSS received liver transplants. These patients were compared to 36 cirrhotic patients, grafted during the same time period, in relation to the implantation technique, the intraoperative use of blood products, and the length of their hospital stay. These groups were comparable for previous right upper quadrant surgery, splanchnic vein modifications, and Child-Pugh classification. Liver transplantation was performed electively in all TIPSS patients. Ten patients (43.4%) presented with a significant shunt stenosis at a median follow-up time of 4.5 months (range 2.5 to 30 months). At transplantation 8 of the 23 TIPSS patients (34.8%) had specific TIPSS-related modifications i.e., extrahepatic portal vein aneurysm formation (n = 2), dislocation of the distal end of the stent into the inferior vena cava (n = 4) or into the main portal vein trunk (n = 1), bilioportal fistula (n = 1), and pronounced phlebitis of the inferior vena cava and hepatic veins due to redilation of shunt stenosis (n = 4). The intraoperative blood product requirement at transplantation was similar in the 23 TIPSS-patients and in the 36 cirrhotic patients who received transplants without the TIPSS procedure during the same time period [median 800 ml (range 0-20300 ml) vs median 620 ml (range 0-7600 ml), respectively]. There was also no difference between the two groups in length of hospital stay [median 18 days (range 0-34 days) vs median 19 days (range 0-66 days), respectively]. We conclude that TIPSS plays an important role in the management of life-threatening complications of end-stage liver disease arising in potential liver transplant candidates. TIPSS should be considered as a temporary, effective bridge to elective transplantation and not as a means to lower the blood product requirement at transplantation. Specific TIPSS-related modifications should be recognized early by the transplant surgeon in order to adapt the technique of graft implantation.

Distal splenorenal shunt versus 10-mm low-diameter mesocaval shunt for variceal hemorrhage

BACKGROUND

Portal hypertension surgery remains a good therapeutic choice for well selected patients with variceal bleeding. The distal splenorenal shunt (DSRS) has shown good long-term results and low-diameter shunts have emerged as an alternate choice.

METHODS

A prospective, controlled and not randomized study was designed to compare the DSRS (23 patients) and the low-diameter 10 mm ring reinforced PTFE mesocaval shunt (LDMCS) (22 patients) in low-risk electively operated patients (Child-Pugh A-B). The operation was selected according to the anatomical status of the veins.

RESULTS

Both groups were comparable. No differences were observed regarding rebleeding, operative mortality and survival. Significative differences were observed regarding encephalopathy and shunt thrombosis (higher in the LDMCS). Postoperative angiography showed better maintenance of portal blood flow in the DSRS group.

CONCLUSIONS

Both operations are adequate alternatives for the elective treatment of portal hypertension in low-risk patients. However, the DSRS has more advantages than the LDMCS.

Medium aperture meso-caval shunts reliably prevent recurrent variceal hemorrhages

BACKGROUND

Objectives of partial medium aperture mesocaval shunts (MCS) include reduction of portal hypertension to prevent recurrent variceal hemorrhage, preservation of portal flow through liver while maintaining an intact porta hepatis to facilitate a future liver transplant (OLTx).

PATIENTS AND METHODS

Fifteen patients were retrospectively analyzed to review the indications for the procedure, its short- and long-term complications as well as patency and functional status of the shunt. They were followed for a period of 21 months.

RESULTS

The perioperative and long-term mortality rate was 0%. Rebleeding rate perioperatively and in follow-up was 0%. Early shunt nonfunction was 13% and post-shunt encephalopathy (PSE) was 20%. The encephalopathy was grade I to II and controlled medically. Abdominal ultrasound and Doppler confirmed 13 patent shunts (2 patients did not agree to ultrasound) with preserved hepatopetal flow in 10.

CONCLUSIONS

Medium aperture MCS utilizing ringed polytetrafluoroethylene (PTFE) grafts safely and reliably prevent recurrent variceal hemorrhage. Encephalopathy is infrequent and mild. This technique preserves the portal venous anatomy making a future OLTx technically easier.