A study of octreotide in oesophageal varices

Treatment for bleeding oesophageal varices in people with decompensated liver cirrhosis: a network meta-analysis

BACKGROUND

Approximately 40% to 95% of people with liver cirrhosis have oesophageal varices. About 15% to 20% of oesophageal varices bleed within about one to three years after diagnosis. Several different treatments are available, including, among others, endoscopic sclerotherapy, variceal band ligation, somatostatin analogues, vasopressin analogues, and balloon tamponade. However, there is uncertainty surrounding the individual and relative benefits and harms of these treatments.

OBJECTIVES

To compare the benefits and harms of different initial treatments for variceal bleeding from oesophageal varices in adults with decompensated liver cirrhosis, through a network meta-analysis; and to generate rankings of the different treatments for acute bleeding oesophageal varices, according to their benefits and harms.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, Science Citation Index Expanded, World Health Organization International Clinical Trials Registry Platform, and trials registers until 17 December 2019, to identify randomised clinical trials (RCTs) in people with cirrhosis and acute bleeding from oesophageal varices.

SELECTION CRITERIA

We included only RCTs (irrespective of language, blinding, or status) in adults with cirrhosis and acutely bleeding oesophageal varices. We excluded RCTs in which participants had bleeding only from gastric varices, those who failed previous treatment (refractory bleeding), those in whom initial haemostasis was achieved before inclusion into the trial, and those who had previously undergone liver transplantation.

DATA COLLECTION AND ANALYSIS

We performed a network meta-analysis with OpenBUGS software, using Bayesian methods, and calculated the differences in treatments using odds ratios (OR) and rate ratios with 95% credible intervals (CrI) based on an available-case analysis, according to National Institute of Health and Care Excellence Decision Support Unit guidance. We performed also the direct comparisons from RCTs using the same codes and the same technical details.

MAIN RESULTS

We included a total of 52 RCTs (4580 participants) in the review. Forty-eight trials (4042 participants) were included in one or more comparisons in the review. The trials that provided the information included people with cirrhosis due to varied aetiologies and those with and without a previous history of bleeding. We included outcomes assessed up to six weeks. All trials were at high risk of bias. A total of 19 interventions were compared in the trials (sclerotherapy, somatostatin analogues, vasopressin analogues, sclerotherapy plus somatostatin analogues, variceal band ligation, balloon tamponade, somatostatin analogues plus variceal band ligation, nitrates plus vasopressin analogues, no active intervention, sclerotherapy plus variceal band ligation, balloon tamponade plus sclerotherapy, balloon tamponade plus somatostatin analogues, balloon tamponade plus vasopressin analogues, variceal band ligation plus vasopressin analogues, balloon tamponade plus nitrates plus vasopressin analogues, balloon tamponade plus variceal band ligation, portocaval shunt, sclerotherapy plus transjugular intrahepatic portosystemic shunt (TIPS), and sclerotherapy plus vasopressin analogues). We have reported the effect estimates for the primary and secondary outcomes when there was evidence of differences between the interventions against the reference treatment of sclerotherapy, but reported the other results of the primary and secondary outcomes versus the reference treatment of sclerotherapy without the effect estimates when there was no evidence of differences in order to provide a concise summary of the results. Overall, 15.8% of the trial participants who received the reference treatment of sclerotherapy (chosen because this was the commonest treatment compared in the trials) died during the follow-up periods, which ranged from three days to six weeks. Based on moderate-certainty evidence, somatostatin analogues alone had higher mortality than sclerotherapy (OR 1.57, 95% CrI 1.04 to 2.41; network estimate; direct comparison: 4 trials; 353 participants) and vasopressin analogues alone had higher mortality than sclerotherapy (OR 1.70, 95% CrI 1.13 to 2.62; network estimate; direct comparison: 2 trials; 438 participants). None of the trials reported health-related quality of life. Based on low-certainty evidence, a higher proportion of people receiving balloon tamponade plus sclerotherapy had more serious adverse events than those receiving only sclerotherapy (OR 4.23, 95% CrI 1.22 to 17.80; direct estimate; 1 RCT; 60 participants). Based on moderate-certainty evidence, people receiving vasopressin analogues alone and those receiving variceal band ligation had fewer adverse events than those receiving only sclerotherapy (rate ratio 0.59, 95% CrI 0.35 to 0.96; network estimate; direct comparison: 1 RCT; 219 participants; and rate ratio 0.40, 95% CrI 0.21 to 0.74; network estimate; direct comparison: 1 RCT; 77 participants; respectively). Based on low-certainty evidence, the proportion of people who developed symptomatic rebleed was smaller in people who received sclerotherapy plus somatostatin analogues than those receiving only sclerotherapy (OR 0.21, 95% CrI 0.03 to 0.94; direct estimate; 1 RCT; 105 participants). The evidence suggests considerable uncertainty about the effect of the interventions in the remaining comparisons where sclerotherapy was the control intervention.

AUTHORS' CONCLUSIONS

Based on moderate-certainty evidence, somatostatin analogues alone and vasopressin analogues alone (with supportive therapy) probably result in increased mortality, compared to endoscopic sclerotherapy. Based on moderate-certainty evidence, vasopressin analogues alone and band ligation alone probably result in fewer adverse events compared to endoscopic sclerotherapy. Based on low-certainty evidence, balloon tamponade plus sclerotherapy may result in large increases in serious adverse events compared to sclerotherapy. Based on low-certainty evidence, sclerotherapy plus somatostatin analogues may result in large decreases in symptomatic rebleed compared to sclerotherapy. In the remaining comparisons, the evidence indicates considerable uncertainty about the effects of the interventions, compared to sclerotherapy.

Primary prevention of variceal bleeding in people with oesophageal varices due to liver cirrhosis: a network meta-analysis

BACKGROUND

Approximately 40% to 95% of people with cirrhosis have oesophageal varices. About 15% to 20% of oesophageal varices bleed in about one to three years. There are several different treatments to prevent bleeding, including: beta-blockers, endoscopic sclerotherapy, and variceal band ligation. However, there is uncertainty surrounding their individual and relative benefits and harms.

OBJECTIVES

To compare the benefits and harms of different treatments for prevention of first variceal bleeding from oesophageal varices in adults with liver cirrhosis through a network meta-analysis and to generate rankings of the different treatments for prevention of first variceal bleeding from oesophageal varices according to their safety and efficacy.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, Science Citation Index Expanded, World Health Organization International Clinical Trials Registry Platform, and trials registers to December 2019 to identify randomised clinical trials in people with cirrhosis and oesophageal varices with no history of bleeding.

SELECTION CRITERIA

We included only randomised clinical trials (irrespective of language, blinding, or status) in adults with cirrhosis and oesophageal varices with no history of bleeding. We excluded randomised clinical trials in which participants had previous bleeding from oesophageal varices and those who had previously undergone liver transplantation or previously received prophylactic treatment for oesophageal varices.

DATA COLLECTION AND ANALYSIS

We performed a network meta-analysis with OpenBUGS using Bayesian methods and calculated the differences in treatments using hazard ratios (HR), odds ratios (OR), and rate ratios with 95% credible intervals (CrI) based on an available-case analysis, according to National Institute for Health and Care Excellence Decision Support Unit guidance. We performed the direct comparisons from randomised clinical trials using the same codes and the same technical details.

MAIN RESULTS

We included 66 randomised clinical trials (6653 participants) in the review. Sixty trials (6212 participants) provided data for one or more comparisons in the review. The trials that provided the information included people with cirrhosis due to varied aetiologies and those at high risk of bleeding from oesophageal varices. The follow-up in the trials that reported outcomes ranged from 6 months to 60 months. All but one of the trials were at high risk of bias. The interventions compared included beta-blockers, no active intervention, variceal band ligation, sclerotherapy, beta-blockers plus variceal band ligation, beta-blockers plus nitrates, nitrates, beta-blockers plus sclerotherapy, and portocaval shunt. Overall, 21.2% of participants who received non-selective beta-blockers ('beta-blockers') - the reference treatment (chosen because this was the most common treatment compared in the trials) - died during 8-month to 60-month follow-up. Based on low-certainty evidence, beta-blockers, variceal band ligation, sclerotherapy, and beta-blockers plus nitrates all had lower mortality versus no active intervention (beta-blockers: HR 0.49, 95% CrI 0.36 to 0.67; direct comparison HR: 0.59, 95% CrI 0.42 to 0.83; 10 trials, 1200 participants; variceal band ligation: HR 0.51, 95% CrI 0.35 to 0.74; direct comparison HR 0.49, 95% CrI 0.12 to 2.14; 3 trials, 355 participants; sclerotherapy: HR 0.66, 95% CrI 0.51 to 0.85; direct comparison HR 0.61, 95% CrI 0.41 to 0.90; 18 trials, 1666 participants; beta-blockers plus nitrates: HR 0.41, 95% CrI 0.20 to 0.85; no direct comparison). No trials reported health-related quality of life. Based on low-certainty evidence, variceal band ligation had a higher number of serious adverse events (number of events) than beta-blockers (rate ratio 10.49, 95% CrI 2.83 to 60.64; 1 trial, 168 participants). Based on low-certainty evidence, beta-blockers plus nitrates had a higher number of 'any adverse events (number of participants)' than beta-blockers alone (OR 3.41, 95% CrI 1.11 to 11.28; 1 trial, 57 participants). Based on low-certainty evidence, adverse events (number of events) were higher in sclerotherapy than in beta-blockers (rate ratio 2.49, 95% CrI 1.53 to 4.22; direct comparison rate ratio 2.47, 95% CrI 1.27 to 5.06; 2 trials, 90 participants), and in beta-blockers plus variceal band ligation than in beta-blockers (direct comparison rate ratio 1.72, 95% CrI 1.08 to 2.76; 1 trial, 140 participants). Based on low-certainty evidence, any variceal bleed was lower in beta-blockers plus variceal band ligation than in beta-blockers (direct comparison HR 0.21, 95% CrI 0.04 to 0.71; 1 trial, 173 participants). Based on low-certainty evidence, any variceal bleed was higher in nitrates than beta-blockers (direct comparison HR 6.40, 95% CrI 1.58 to 47.42; 1 trial, 52 participants). The evidence indicates considerable uncertainty about the effect of the interventions in the remaining comparisons.

AUTHORS' CONCLUSIONS

Based on low-certainty evidence, beta-blockers, variceal band ligation, sclerotherapy, and beta-blockers plus nitrates may decrease mortality compared to no intervention in people with high-risk oesophageal varices in people with cirrhosis and no previous history of bleeding. Based on low-certainty evidence, variceal band ligation may result in a higher number of serious adverse events than beta-blockers. The evidence indicates considerable uncertainty about the effect of beta-blockers versus variceal band ligation on variceal bleeding. The evidence also indicates considerable uncertainty about the effect of the interventions in most of the remaining comparisons.

Secondary prevention of variceal bleeding in adults with previous oesophageal variceal bleeding due to decompensated liver cirrhosis: a network meta-analysis

BACKGROUND

Approximately 40% to 95% of people with cirrhosis have oesophageal varices. About 15% to 20% of oesophageal varices bleed in about one to three years of diagnosis. Several different treatments are available, which include endoscopic sclerotherapy, variceal band ligation, beta-blockers, transjugular intrahepatic portosystemic shunt (TIPS), and surgical portocaval shunts, among others. However, there is uncertainty surrounding their individual and relative benefits and harms.

OBJECTIVES

To compare the benefits and harms of different initial treatments for secondary prevention of variceal bleeding in adults with previous oesophageal variceal bleeding due to decompensated liver cirrhosis through a network meta-analysis and to generate rankings of the different treatments for secondary prevention according to their safety and efficacy.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, Science Citation Index Expanded, World Health Organization International Clinical Trials Registry Platform, and trials registers until December 2019 to identify randomised clinical trials in people with cirrhosis and a previous history of bleeding from oesophageal varices.

SELECTION CRITERIA

We included only randomised clinical trials (irrespective of language, blinding, or status) in adults with cirrhosis and previous history of bleeding from oesophageal varices. We excluded randomised clinical trials in which participants had no previous history of bleeding from oesophageal varices, previous history of bleeding only from gastric varices, those who failed previous treatment (refractory bleeding), those who had acute bleeding at the time of treatment, and those who had previously undergone liver transplantation.

DATA COLLECTION AND ANALYSIS

We performed a network meta-analysis with OpenBUGS using Bayesian methods and calculated the differences in treatments using hazard ratios (HR), odds ratios (OR) and rate ratios with 95% credible intervals (CrI) based on an available-case analysis, according to National Institute of Health and Care Excellence Decision Support Unit guidance.

MAIN RESULTS

We included a total of 48 randomised clinical trials (3526 participants) in the review. Forty-six trials (3442 participants) were included in one or more comparisons. The trials that provided the information included people with cirrhosis due to varied aetiologies. The follow-up ranged from two months to 61 months. All the trials were at high risk of bias. A total of 12 interventions were compared in these trials (sclerotherapy, beta-blockers, variceal band ligation, beta-blockers plus sclerotherapy, no active intervention, TIPS (transjugular intrahepatic portosystemic shunt), beta-blockers plus nitrates, portocaval shunt, sclerotherapy plus variceal band ligation, beta-blockers plus nitrates plus variceal band ligation, beta-blockers plus variceal band ligation, sclerotherapy plus nitrates). Overall, 22.5% of the trial participants who received the reference treatment (chosen because this was the commonest treatment compared in the trials) of sclerotherapy died during the follow-up period ranging from two months to 61 months. There was considerable uncertainty in the effects of interventions on mortality. Accordingly, none of the interventions showed superiority over another. None of the trials reported health-related quality of life. Based on low-certainty evidence, variceal band ligation may result in fewer serious adverse events (number of people) than sclerotherapy (OR 0.19; 95% CrI 0.06 to 0.54; 1 trial; 100 participants). Based on low or very low-certainty evidence, the adverse events (number of participants) and adverse events (number of events) may be different across many comparisons; however, these differences are due to very small trials at high risk of bias showing large differences in some comparisons leading to many differences despite absence of direct evidence. Based on low-certainty evidence, TIPS may result in large decrease in symptomatic rebleed than variceal band ligation (HR 0.12; 95% CrI 0.03 to 0.41; 1 trial; 58 participants). Based on moderate-certainty evidence, any variceal rebleed was probably lower in sclerotherapy than in no active intervention (HR 0.62; 95% CrI 0.35 to 0.99, direct comparison HR 0.66; 95% CrI 0.11 to 3.13; 3 trials; 296 participants), beta-blockers plus sclerotherapy than sclerotherapy alone (HR 0.60; 95% CrI 0.37 to 0.95; direct comparison HR 0.50; 95% CrI 0.07 to 2.96; 4 trials; 231 participants); TIPS than sclerotherapy (HR 0.18; 95% CrI 0.08 to 0.38; direct comparison HR 0.22; 95% CrI 0.01 to 7.51; 2 trials; 109 participants), and in portocaval shunt than sclerotherapy (HR 0.21; 95% CrI 0.05 to 0.77; no direct comparison) groups. Based on low-certainty evidence, beta-blockers alone and TIPS might result in more, other compensation, events than sclerotherapy (rate ratio 2.37; 95% CrI 1.35 to 4.67; 1 trial; 65 participants and rate ratio 2.30; 95% CrI 1.20 to 4.65; 2 trials; 109 participants; low-certainty evidence). The evidence indicates considerable uncertainty about the effect of the interventions including those related to beta-blockers plus variceal band ligation in the remaining comparisons.

AUTHORS' CONCLUSIONS

The evidence indicates considerable uncertainty about the effect of the interventions on mortality. Variceal band ligation might result in fewer serious adverse events than sclerotherapy. TIPS might result in a large decrease in symptomatic rebleed than variceal band ligation. Sclerotherapy probably results in fewer 'any' variceal rebleeding than no active intervention. Beta-blockers plus sclerotherapy and TIPS probably result in fewer 'any' variceal rebleeding than sclerotherapy. Beta-blockers alone and TIPS might result in more other compensation events than sclerotherapy. The evidence indicates considerable uncertainty about the effect of the interventions in the remaining comparisons. Accordingly, high-quality randomised comparative clinical trials are needed.

Outcomes of patients treated with Sengstaken-Blakemore tube for uncontrolled variceal hemorrhage

BACKGROUND/AIMS

The aim of this study was to investigate the mortality, bleeding control rate, and their associated predictors in patients treated with Sengstaken-Blakemore (SB) tube for uncontrolled variceal hemorrhage associated with hemodynamic instability or failure of endoscopic treatment.

METHODS

The clinical data of 66 consecutive patients with uncontrolled variceal hemorrhage treated with SB tube at Gyeongsang National University Hospital from October 2010 to October 2015 were retrospectively analyzed.

RESULTS

The overall success rate of initial hemostasis with SB tube was 75.8%, and the independent factors associated with hemostasis were non-intubated state before SB tube (odds ratio, 8.50; p = 0.007) and Child-Pugh score < 11 (odds ratio, 15.65; p = 0.022). Rebleeding rate after successful initial hemostasis with SB tube was 22.0%, and esophageal rupture occurred in 6.1%. Mortality within 30 days was 42.4%, and the related independent factors with mortality were failure of initial hemostasis with SB tube (hazard ratio, 6.24; p < 0.001) and endotracheal intubation before SB tube (hazard ratio, 2.81; p = 0.018).

CONCLUSIONS

Since the era of endoscopic band ligation, SB tube might be a beneficial option as a temporary salvage treatment for uncontrolled variceal hemorrhage. However, rescue therapy had a high incidence of fatal complication and rebleeding.

Nonendoscopic management strategies for acute esophagogastric variceal bleeding

Acute variceal bleeding is a potentially life-threatening complication of portal hypertension. Management consists of emergent hemostasis, therapy directed at hemodynamic resuscitation, protection of the airway, and prevention and treatment of complications including prophylactic use of antibiotics. Endoscopic treatment remains the mainstay in the management of acute variceal bleeding in combination with pharmacotherapy aimed at reducing portal pressure. This article intends to highlight only the current nonendoscopic treatment approaches for control of acute variceal bleeding.

Acute variceal hemorrhage

Variceal bleeding is a frequent and life-threatening complication of portal hypertension. The first episode of variceal bleeding is associated not only with a high mortality, but also with a high recurrence rate in those who survive. Therefore, management should focus on different therapeutic strategies aiming to prevent the first episode of variceal bleeding (primary prophylaxis), to control hemorrhage during the acute bleeding episode (emergency treatment), and to prevent rebleeding (secondary prophylaxis). These strategies involve pharmacological, endoscopic, surgical, and interventional radiological modalities. This article reviews management of acute variceal bleeding.

Somatostatin, somatostatin analogues and other vasoactive drugs in the treatment of bleeding oesophageal varices

Somatostatin and its analogues have been compared with a variety of other treatments for the treatment of variceal bleeding in cirrhotic patients. Meta-analyses of studies comparing somatostatin or octreotide with vasopressin or terlipressin have shown that somatostatin is somewhat superior to vasopressin and equivalent to terlipressin in controlling bleeding and has significantly fewer side effects; no difference in mortality was observed. Octreotide was somewhat better than vasopressin and terlipressin in controlling bleeding, with similar mortality. Meta-analysis of trials comparing somatostatin or octreotide with endoscopic sclerotherapy shows that both drugs are equivalent to sclerotherapy for bleeding control, early rebleeding and survival. Complications are much less frequent with drug treatment. Nine trials have compared endoscopic therapy with therapeutic regimens combining endoscopic treatment with somatostatin, octreotide or vapreotide. Meta-analysis show that the combined regimens increase the 5 days bleeding control rate of endoscopic treatments by over 20%, although there is no difference in mortality. Comparisons of somatostatin and octreotide with combined regimens of sclerotherapy + somatostatin and sclerotherapy + octreotide have shown that the combined regimens were better than drug treatments alone in controlling bleeding and preventing early rebleeding, while complications were significantly less frequent with drug therapy.

Octreotide therapy for control of acute gastrointestinal bleeding in children

OBJECTIVES

To evaluate the outcomes of octreotide use in children with gastrointestinal bleeding with or without portal hypertension.

METHODS

The medical charts of children who received continuous octreotide infusion for the indication of gastrointestinal bleeding from January 1995 to December 2000 were retrospectively reviewed.

RESULTS

Twenty-one children with portal hypertension received octreotide infusions (1-2 microg/kg/h) during 35 gastrointestinal bleeding episodes. The duration of infusion ranged from 19 hours to 7 days. Bleeding ceased in 71% of children. Post-treatment rebleeding occurred in 52%, and the mortality was 19%. Response to octreotide, rebleeding, and mortality did not differ significantly between patients with or without intrinsic liver disease. Twelve children with gastrointestinal bleeding unrelated to portal hypertension received octreotide during 14 episodes. The duration of octreotide ranged from 3 hours to 36 days. Fifty percent of children had resolution of bleeding during the infusion. Post-treatment rebleeding occurred in 29%, and the mortality was 50%. No major adverse events were observed in either group.

CONCLUSIONS

A high rate of bleeding control was achieved with octreotide during acute gastrointestinal bleeding in children with portal hypertension. However, controlled studies are needed for more definitive description of its clinical effects. The role of octreotide is less clear in gastrointestinal bleeding unrelated to portal hypertension.

Recent advances in the endoscopic diagnosis and therapy of upper gastrointestinal, small intestinal, and colonic bleeding

Endoscopy has become the first and primary diagnostic and therapeutic modality in the management of patients with severe gastrointestinal bleeding. Panendoscopy, push enteroscopy, and colonoscopy provide the diagnostic, prognostic, and therapeutic elements to improve patient outcomes and to reduce morbidity and mortality from severe GI hemorrhage. Recent improvements in endoscopic hemostatic techniques and in imaging modalities using wireless capsule endoscopy suggest that diagnostic and therapeutic endoscopy will be even more important in determining patient outcomes in the future.

Management of portal hypertension after variceal hemorrhage

Each variceal bleed is associated with 20% to 30% risk of dying. Management of portal hypertension after a bleed consists of (1) control of bleeding and (2) prevention of rebleeding. Effective control of bleeding can be achieved either pharmacologically by administering somatostatin or octreotide or endoscopically via sclerotherapy or variceal band ligation. In practice, both pharmacologic and endoscopic therapy are used concomitantly. Rebleeding can be prevented by endoscopic obliteration of varices. In this setting, variceal ligation is the preferred endoscopic modality. B-blockade is as effective as endoscopic therapy and, in combination, the two modalities may be additive.

Bolus somatostatin but not octreotide reduces hepatic sinusoidal pressure by a NO-independent mechanism in chronic liver disease

BACKGROUND

Evidence exists that somatostatin and octreotide might have different effects on hepatic haemodynamics.

AIM

The investigation of the effects of somatostatin and its octapeptide analogue, octreotide, on sinusoidal pressure measured by the wedged hepatic venous pressure in patients with cirrhosis or chronic hepatitis and the correlation with the levels of hepatic vein NO.

METHODS

Patients were randomly assigned to receive an injection of either 250 microg somatostatin (n=14: cirrhosis six, chronic hepatitis eight) or an injection of 125 microg octreotide (n=19: cirrhosis nine, chronic hepatitis 10) during hepatic vein catheterization. Baseline wedged hepatic venous pressure was measured, followed by measurements at 2, 5, 10 and 15 min after the injection of the drug. Nitrites/nitrates of the hepatic vein were measured before the injection and after 15 min.

RESULTS

Both agents showed a similar qualitative but a different quantitative haemodynamic profile. No change in the wedged hepatic venous pressure was observed during the first 2 min after the injection of both drugs. This was followed by a decrease: 18% at 5 min (N.S.), 23% at 10 min (P < 0.01) and 24% at 15 min (P < 0.01) for somatostatin. Octreotide induced a relatively smaller decrease in the wedged hepatic venous pressure: 8% at 5 min (N.S.), 20% at 10 min (P < 0.01) and 16% at 15 min (N.S.). Further analysis of the sub-groups of cirrhotic and chronic hepatitis patients revealed a different effect. In the sub-group of cirrhotic patients, somatostatin caused a maximum decrease of 34% at 15 min post-injection (P < 0.01), but octreotide failed to produce a significant change on the wedged hepatic venous pressure. In contrast, no change was observed in chronic hepatitis patients with either drug. No change in the hepatic vein concentration of NO after treatment was observed with either somatostatin or octreotide. Moreover, no correlation of the levels of NO with the wedged hepatic venous pressure values was found.

CONCLUSIONS

This study shows that somatostatin is more effective than octreotide in acutely reducing the wedged hepatic venous pressure after bolus injection and the observed change is probably mediated by a NO-independent mechanism.

Octreotide for acute variceal bleeding

OBJECTIVE

To review the use o f octreotide for acute variceal bleeding.

DATA SOURCES

Articles were obtained through computerized searches involving MEDLINE (from 1997 to October 2000). Additionally, several textbooks containing information on the diagnosis and management of acute variceal bleeding were reviewed. The bibliographies of retrieved publications and textbooks were reviewed for additional references.

STUDY SELECTION

All randomized studies and pharmacoeconomic evaluations that used octreotide therapy for acute variceal bleeding were considered. Randomized controlled trials and meta-analyses involving other therapies for treating variceal bleeding were also reviewed for possible inclusion.

DATA EXTRACTION

The primary outcomes extracted from the literature were persistent or recurrent bleeding, need for endoscopic intervention or balloon tamponade, and mortality.

DATA SYNTHESIS

Although both endoscopic therapies and medications are used to control bleeding and rebleeding episodes, the endoscopic approach has the additional goal of obliterating the varix. Since rebleeding episodes are common as long as the varix is present, endoscopic and medication therapies cannot be considered interchangeable based on bleeding control alone. However, octreotide by continuous intravenous infusion has demonstrated effectiveness in reducing blood loss and transfusion requirements as both an initial intervention (until definitive sclerotherapy can be performed) or as adjunctive therapy to endoscopic measures. Octreotide can be started quickly, has a relatively rapid onset of action, and does not require someone with endoscopy training to initiate. Additionally, octreotide is relatively free of significant adverse effects.

CONCLUSIONS

While additional investigations are needed, particularly in the area of pharmacoeconomics, there is substantial evidence that octreotide is an efficacious therapy with relatively few adverse effects when used in the management of acute variceal bleeding.

Management of acute variceal haemorrhage

Endoscopic therapy and in particular endoscopic variceal banding ligation, in experienced hands, is the treatment of choice for acute variceal bleeding which remains a major cause of death in patients with cirrhosis and portal hypertension. Pharmacological therapy with Glypressin or somatostatin can be useful to gain time when the endoscopic expertise is not available or to help to obtain a clearer endoscopic view. Transjugular intrahepatic porto-systemic stent shunt is currently used for endoscopic failures, producing similar results with the surgical portacaval shunts. Which one of the two should be preferred, since they both work best in relatively compensated patients, should be a balance between the available surgical and radiological expertise, the urgency of the situation and the expected course of the disease.

Pharmacologic therapy for portal hypertension

Pharmacologic therapy for portal hypertension is effective in the treatment and prevention of hemorrhage from esophagogastric varices. Acute hemorrhage from varices can be treated with intravenous agents such as somatostatin or terlipressin, either alone or in combination with endoscopic sclerotherapy or band ligation. Intravenous octreotide has not shown effectiveness as monotherapy, but it appears to be beneficial when combined with endoscopic treatment. The prevention of rebleeding after initial hemorrhage is best accomplished with non-selective beta blockers, endoscopic band ligation of varices, or a combination of endoscopic and pharmacologic therapies. The addition of oral nitrates may further decrease rebleeding rates, but more data from randomized trials are needed. Beta blockers are currently the only agents recommended for the primary prevention of variceal hemorrhage.

Drug treatment for bleeding oesophageal varices

At the time of diagnosis of cirrhosis, varices are present in about 60% of decompensated and 30% of compensated patients. The risk factors for the first episode of variceal bleeding in cirrhotic patients are the severity of liver dysfunction, a large size of the varices and the presence of endoscopic red colour signs, but only a third of patients who suffer variceal haemorrhage demonstrate the above risk factors. The only treatment that does not require sophisticated equipment or the skills of a specialist, and is immediately available, is vasoactive drug therapy. Hence, drug therapy should be considered to be the initial treatment of choice and can be administered while the patient is transferred to hospital, as has been done in one recent study. Moreover, drug therapy is no longer considered to be only a 'stop-gap' therapy until definitive endoscopic therapy is performed. Several recent trials have reported an efficacy similar to that of emergency sclerotherapy in the control of variceal bleeding. Furthermore, recent evidence suggests that those patients with high variceal or portal pressure are likely to continue to bleed or re-bleed early, implying that prolonged therapy lowering the portal pressure over several days may be the optimal treatment. Pharmacological treatment with beta-blockers is safe, effective and the standard long-term treatment for the prevention of recurrence of variceal bleeding. The combination of beta-blockers with isosorbide-5-mononitrate needs further testing in randomized controlled trials. The use of haemodynamic targets for the reduction of the HVPG response needs further study, and surrogate markers of the pressure response need evaluation. Ligation has recently been compared with beta-blockers for primary prophylaxis, but there is as yet no good evidence to recommend banding for primary prophylaxis if beta-blockers can be given.

Esophageal varices. I. Clinical presentation, medical therapy, and endoscopic therapy

The last half century has witnessed great advances in the understanding of the pathogenesis and natural history of portal hypertension in cirrhotics. Several pharmacologic and endoscopic techniques have been developed for the treatment of portal hypertension. The use of these agents in a given patient must be based on an understanding of the stage in the natural history of the disease and the relative efficacy and safety of the available treatment options.

Complications of cirrhosis. I. Portal hypertension

Increased resistance to portal blood flow is the primary factor in the pathophysiology of portal hypertension, and is mainly determined by the morphological changes occurring in chronic liver diseases. This is aggravated by a dynamic component, due to the active-reversible- contraction of different elements of the porto-hepatic bed. A decreased synthesis of NO in the intrahepatic circulation is the main determinant of this dynamic component. This provides a rationale for the use of vasodilators to reduce intrahepatic resistance and portal pressure. Another factor contributing to aggravate the portal hypertension is a significant increase in portal blood flow, caused by arteriolar splanchnic vasodilation and hyperkinetic circulation. Splanchnic arteriolar vasodilation is a multifactorial phenomenon, which may involve local (endothelial) mechanisms as well as neurogenic and humoral pathways. Most pharmacological treatments have been aimed at correcting the increased portal blood inflow by the use of splanchnic vasoconstrictors, such as beta-blockers, vasopressin derivatives and somatostatin. Several studies have demonstrated that changes in the hepatic venous pressure gradient (HVPG) during maintenance therapy are useful to identify those patients who are going to have a variceal bleeding or rebleeding. The wide individual variation in the HVPG response to pharmacological treatment makes it desirable to schedule follow-up measurements of HVPG during pharmacological therapy. A priority for research in the forthcoming years is to develop accurate non-invasive methods to assess prognosis, which can be used to substitute or as surrogate indicators of the HVPG response. In the clinical management of portal hypertension, beta-blockers are at present the only accepted treatment for the prevention of variceal bleeding. Whether the association of isosorbide-5-mononitrate will improve the high efficacy of beta-blockers is questionable. The efficacy of more aggressive techniques, such as endoscopic band ligation, should be further tested against beta-blockers in patients with a high risk of bleeding. In the treatment of acute variceal bleeding, administration of somatostatin or terlipressin is an established therapy. It may be used alone or, preferably, as an initial treatment before sclerotherapy or endoscopic band ligation. No more than two sessions of endoscopic treatment should be used to control the bleeding. If the bleeding is not easily controlled, other alternatives such as transjugular intrahepatic portosystemic shunts (TIPS) or derivative surgery should be considered, the former being the best in patients with poor liver function. Recent studies suggest that early measurement of HVPG during variceal bleeding may be used as a guide for therapeutic decisions in the treatment of patients with acute variceal bleeding. Those patients with a high HVPG have a high risk of poor evolution, and may be candidates for more intensive and aggressive therapy, such as surgery or TIPS. Those with lower HVPG have a very high probability of an uneventful evolution, and may thus be managed more conservatively using medical and endoscopic treatments. Pharmacological agents (propranolol or nadolol), endoscopic treatment (preferably banding ligation) or surgery can be used to prevent rebleeding. A pending task for the new millennium is to assess whether the early treatment of asymptomatic, compensated cirrhotic patients with portal pressure reducing agents can prevent the development of esophageal varices and of other complications of portal hypertension.

Management of gastrointestinal bleeding induced by gastrointestinal endoscopy

Therapeutic gastrointestinal endoscopy has a much greater risk of inducing gastrointestinal hemorrhage than diagnostic endoscopy. For example, colonoscopic polypectomy has a risk of approximately 1.6% of inducing bleeding, compared with a risk of approximately 0.02% for diagnostic colonoscopy. Higher-risk procedures include colonoscopic polypectomy, endoscopic biliary sphincterotomy, endoscopic dilatation, endoscopic variceal therapy, percutaneous endoscopic gastrostomy, and endoscopic sharp foreign body retrieval. The risk of inducing hemorrhage is decreased by meticulous endoscopic technique. Hemorrhage from endoscopy may be immediate or delayed. Immediate hemorrhage should be immediately treated by endoscopic hemostatic therapy, including injection therapy, thermocoagulation, or electrocoagulation. Delayed hemorrhage generally requires repeat endoscopy for diagnosis and for therapy, using the same hemostatic techniques.

Role of octreotide on release of intact 1-84 parathyroid hormone from human parathyroid cells

BACKGROUND

Octreotide has been shown to lower urinary calcium in primary hyperparathyroidism although the mechanism remains unclear. This study examined the effect of octreotide on parathyroid hormone (PTH) secretion from human parathyroid cells in culture and as isolated cells. Additionally in situ hybridization was performed for somatostatin receptor messenger RNA (mRNA) and immunocytochemistry for somatostatin in eight parathyroid adenomas.

METHODS

Tissue from three hyperplastic glands and three adenomas was studied as dispersed cell suspensions. Incubation was in buffers containing high (2.0 mmol/l) and low (0.5 mmol/l) calcium concentrations, with or without octreotide 200 ng/ml. Cells were also seeded into tissue culture wells for 24 h to allow receptors to regenerate. Supernatant was removed at regular intervals and PTH levels were estimated using a two-site chemiluminescent assay.

RESULTS

Mean(s.e.m.) PTH secretion at 90 min in hyperplastic cells was 445(75) pmol/l in low calcium and 160(42) pmol/l in high calcium (P< 0.02), and in adenoma cells was 170(21) pmol/l in low calcium and 137(27) pmol/l in high calcium (P=0.37). There was no significant difference in secretion of PTH from cells incubated with octreotide either in culture or as dispersed cells. In situ hybridization failed to demonstrate any mRNA for the somatostatin receptors and no somatostatin was detected in any cells with immunocytochemistry.

CONCLUSION

Somatostatin has no direct action on PTH production and release from human parathyroid cells and is unlikely to be of any therapeutic value in the treatment of hyperparathyroidism.

Advances in drug therapy for acute variceal haemorrhage

Recent advances in the pharmacology of portal hypertension are reviewed, against the background of existing knowledge and current clinical research. The most recent trials are analysed, and conclusions made about the use of drugs in acute variceal haemorrhage, as well as directions for further clinical trials and research.

The pharmacokinetics of octreotide in cirrhosis and in healthy man

BACKGROUND/AIM

The aim of the study was to evaluate the pharmacokinetics of octreotide in patients with cirrhosis compared to healthy volunteers.

METHODS

Seventeen patients with cirrhosis and nine normals received an intravenous bolus of octreotide (0.75 microgram/kg), followed by a continuous infusion of 0.75 microgram.kg-1.h-1 for 12 h. Eight patients were decompensated with ascites, while nine were without signs of decompensation. Serum octreotide levels were followed by blood sampling during the infusion period and for 24 h afterwards.

RESULTS

The average clearance (+/-SEM) was 151 +/- 15 ml/min in normals compared to 102 +/- 9 (p < 0.05) and 105 +/- 9 (p < 0.05) in patients with compensated and decompensated cirrhosis, respectively. The average area under the serum octreotide curve was significantly increased by 53% (p < 0.05) in decompensated and 46% (p < 0.05) in compensated cirrhosis compared to healthy volunteers, while no difference was observed between the groups with cirrhosis. This difference was also reflected by an increased maximum serum concentration during the infusion period of 9797 +/- 580 ng/l in the patients with cirrhosis compared to 7081 +/- 547 ng/l (p = 0.006) in normals. The serum half-life for the beta-phase (T1/2 beta) was 165 +/- 26 min in normals, 200 +/- 21 min in the compensated and 216 +/- 26 min in the decompensated group (NS). The volume of distribution (Vd beta) showed no difference between the three groups. Because of the slow equilibration between plasma and ascitic fluid in decompensated cirrhosis, the calculated clearance may have been overestimated and T1/2 beta and Vd beta underestimated in these patients.

CONCLUSIONS

The present study demonstrates that the pharmacokinetics of octreotide in cirrhosis is substantially different from that found in normals.

Effect of octreotide on systemic, central, and splanchnic haemodynamics in cirrhosis

BACKGROUND/AIMS

Cirrhosis with portal hypertension is associated with changes in the splanchnic and systemic haemodynamics, and subsequent complications, such as bleeding from oesophageal varices, have led to the introduction of long-acting somatostatin analogues in the treatment of portal hypertension. However, reports on the splanchnic and systemic effects of octreotide are contradictory and therefore the aim of the present study was to assess the effects of continuous infusion of octreotide on central and systemic haemodynamics, portal pressures, and hepatic blood flow.

METHODS

Thirteen patients with cirrhosis underwent liver vein catheterisation. Portal and arterial blood pressures were determined at baseline and 10, 30, and 50 min after a bolus injection of octreotide 100 micrograms, followed by continuous infusion of octreotide 100 micrograms/ h for 1 h. Hepatic blood flow, cardiac output, central and arterial blood volume, and central circulation time were determined at baseline and 50 min after the start of the octreotide infusion.

RESULTS

The mean arterial blood pressure increased during the first 10 min (p < 0.0005), but returned to baseline after 50 min. The central and arterial blood volume (-16%, p < 0.005) and the central circulation time (-8%, p < 0.05) were significantly decreased after 50 min, whereas the cardiac output did not change significantly. The hepatic venous pressure gradient and the hepatic blood flow did not change significantly at any time after infusion of octreotide.

CONCLUSIONS

Octreotide does not affect the portal pressure or hepatic blood flow, whereas it may further contract the central blood volume and thereby exert a potentially harmful effect on central hypovolaemia in patients with cirrhosis. However, these early effects do not exclude the possibility that administration of longacting somatostatin analogues over a longer period may have a beneficial effect.

Octreotide or vasopressin for bleeding esophageal varices

Acute bleeding due to esophageal varices continues to be a life-threatening complication of liver disease. Despite the availability of improved therapy, mortality continues to be high. Octreotide has been shown to be at least as effective as vasopressin in the treatment of bleeding varices, with fewer and less severe systemic adverse effects. In addition, octreotide has also been consistently associated with a decreased need for transfusions. Octreotide has been used safely in patients without serious cardiovascular disease when administered as a continuous intravenous infusion of 25 micrograms/h for 24 hours with or without an initial 100-micrograms bolus dose. Since these trials have used small numbers of patients, the ability to detect small but clinically important differences has been limited. Additional controlled trials comparing octreotide with the combination of vasopressin and nitroglycerin are needed to more clearly determine the efficacy and cost-effectiveness of therapy. Furthermore, the optimal dosage, duration, and route of administration of octreotide in the treatment of bleeding esophageal varices has yet to be determined.

The role of pharmacologic agents in blood conservation

Pharmacologic agents are welcome therapeutic weapons in the fight to conserve blood. The goals of drug therapy cross a broad spectrum of potential areas. Blood-conserving pharmacologic agents are aimed at 1) increasing blood production, 2) decreasing blood loss during active bleeding, and 3) preventing the breakdown of the formed fibrin clots. In this article, the author reviews the mechanisms of action, dosing, and adverse effects of these agents. The role of pharmacologic agents in blood conservation is significant because these agents have been shown to decrease transfusion requirements and provide significant cost savings.

Assessment of variceal pressure by continuous non-invasive endoscopic registration: a placebo controlled evaluation of the effect of terlipressin and octreotide

Octreotide has been proposed for the treatment of variceal bleeding. The effects on portal pressure, however, have been variable in published studies. As bleeding is more directly related to pressure in the varices, this study investigated the effect on variceal pressure of octreotide and terlipressin, a vasoactive drug with a well established effect. Variceal pressure was measured during four to eight minutes by a continuous non-invasive endoscopic registration method. Thirty patients in whom a stable variceal pressure recording had been obtained during at least one minute, were randomised to receive either 2 mg terlipressin, 50 micrograms octreotide or an identical volume of saline, as a single intravenous injection given over 60 seconds. For the final analysis three patients had to be excluded because of lack of a satisfactory recording. There were no significant clinical differences between the three groups of patients. Placebo administration did not induce significant changes, but a mean decrease in variceal pressure of -27% was noted with terlipressin, starting from two minutes onwards. Variceal pressure changes after injection of octreotide were variable and the mean change in pressure did not reach statistical significance. Seven of 10 patients showed a temporary increase in variceal pressure. In conclusion, terlipressin induces a significant and progressive decrease in variceal pressure but inconsistent variations of variceal pressure changes were seen after octreotide administration. This is probably related to its effect on central venous pressure. This study also shows that continuous variceal pressure recording with the non-invasive endoscopic registration technique detects in an accurate way the effect of vasoactive drugs on variceal pressure, because placebo injection did not produce significant changes.

Sclerotherapy with or without octreotide for acute variceal bleeding

BACKGROUND

Sclerotherapy is considered the most effective way to stop bleeding from esophageal varices, but acute variceal bleeding is still associated with a high risk of rebleeding and death. We compared sclerotherapy alone with sclerotherapy and octreotide to control acute variceal bleeding and prevent early rebleeding in patients with cirrhosis.

METHODS

In a double-blind, prospective trial, 199 patients with cirrhosis and acute variceal bleeding who underwent emergency sclerotherapy were randomly assigned to receive a continuous infusion of octreotide (25 micrograms per hour) or placebo for five days. The primary outcome measure was survival without rebleeding five days after sclerotherapy.

RESULTS

After five days, the proportion of patients who had survived without rebleeding was higher in the octreotide group (85 of 98 patients, or 87 percent) than in the placebo group (72 of 101, or 71 percent; 95 percent confidence interval for the difference, 4 to 27 percent; P = 0.009). The mean number of units of blood transfused within the first 24 hours after sclerotherapy was lower in the octreotide group (1.2 units; range, 0 to 7) than in the placebo group (2.0 units; range, 0 to 10; P = 0.006). A logistic-regression analysis showed that the treatment assignment (P = 0.003) and the number of blood units transfused before any other treatment was undertaken (P = 0.002) were the only two variables independently associated with survival without rebleeding. After adjustment for base-line differences between the two groups, the odds ratio for treatment failure in the placebo group, as compared with the octreotide group, was 3.3 (95 percent confidence interval, 1.5 to 7.3). The mean (+/- SD) 15-day cumulative survival rate (estimated by the Kaplan-Meier method) was 88 +/- 12 percent in both groups. Side effects were minor, and their incidence was similar in the two groups.

CONCLUSIONS

In patients with cirrhosis, the combination of sclerotherapy and octreotide is more effective than sclerotherapy alone in controlling acute variceal bleeding, but there is no difference between the overall mortality rates associated with the two approaches to treatment.

Vasoconstrictors in the management of bleeding from oesophageal varices. A clinico-economic appraisal in the UK

BACKGROUND

Bleeding from oesophageal varices is an uncommon but potentially fatal condition that often leads to expensive hospitalizations in intensive care or high-dependency units.

METHODS

To assess the clinical and economic impact of this condition, we have devised a management plan illustrating current clinical practice in the UK.

RESULTS

Approximately 6.1 million pounds of NHS resources are devoted to the treatment of 3000 acute hospital admissions for variceal bleeding every year. Vasoconstrictors like vasopressin may save approximately 36 lives per annum for an additional 145 thousand pounds. However, current clinical practice requires vasopressin to be concurrently administered with intravenous glyceryl trinitrate, increasing overall costs by 582 thousand pounds to a total of 6.7 million pounds. The additional cost for each extra life saved is estimated at 16,180 pounds.

CONCLUSION

The efficacy of current vasoconstrictors requires further confirmation. In particular, new agents like octreotide (Sandostatin) should be carefully assessed to determine their potential clinical and economic benefits.

Octreotide versus terlypressin in acute variceal hemorrhage in liver cirrhosis. Emergency control and prevention of early rebleeding

Sixty patients with endoscopically confirmed active variceal bleeding entered a randomized controlled clinical trial aimed at comparing the efficacy of octreotide vs. terlypressin in the control of acute variceal hemorrhage (period I, 24 h) and in the prevention of early rebleeding (period II, 6 days). Of the sixty 30 received octreotide (period I, 100 micrograms bolus followed by continuous intravenous infusion at 25 micrograms/h; period II, 100 micrograms t.i.d. subcutaneously), and 30 received terlypressin (period I, 2 mg intravenous bolus every 4 h; period II, 2nd day, 2 mg every 6 h; from 3th to 7th days, 1 mg every 6 h). Control of bleeding was achieved in 23 (76.6%) patients receiving octreotide and in 16 (53%) treated with terlypressin (NS); none of these patients suffered rebleeding during treatment. No significant difference in mortality was observed between the two groups during the hospitalization period. Complications due to therapy were lower with octreotide than with terlypressin (P < 0.01). Under the same effectiveness conditions the cost/benefit ratio must be taken into account.

Expanding uses of octreotide

This chapter reviews the therapeutic use of octreotide in a variety of pancreatic disorders, including acute pancreatitis, in the prevention of postoperative and post-ERCP pancreatitis, in the control of postoperative pancreatic fistulae, and in chronic pancreatitis for the control of pain and of pseudocysts and ascites. The review also discusses the use of octreotide in intestinal disorders of motility, gastrointestinal bleeding, intestinal fistulae and refractory diarrhoea, including the diarrhoeas of AIDS, diabetes, short gut, chemotherapy, ileostomy and gastric surgery. The use of octreotide in neuroendocrine tumours, both for therapy and diagnostic imaging, is reviewed briefly. The paucity of adequately controlled studies in many of these situations is indicated and the potential usefulness of octreotide estimated.

Management of variceal haemorrhage

Fig 2 gives an algorithm for the treatment of bleeding oesophageal varices. Initial resuscitation of the patient is of paramount importance, ideally followed by early interventional endoscopy. Recent advances in available endoscopic techniques enable the endoscopist to suit the therapeutic approach to the clinical situation. Injection sclerotherapy remains the initial treatment of choice in bleeding patients. Endoscopic banding ligation is an alternative, best used in patients who have spontaneously stopped bleeding or as a complementary treatment a few days after the initial session of injection sclerotherapy. The tissue adhesives and thrombin can be used to treat bleeding gastric varices. [table: see text] Should the endoscopic expertise not be available, drug treatment (with somatostatin or octreotide) or balloon tamponade are the treatments of choice. Transjugular intrahepatic portal-systemic stent shunt is a new effective technique, not yet widely available, which has a documented complication rate that has yet to be fully defined. It is a good alternative to surgery as a "rescue" procedure for patients who continue to bleed despite two sessions of endoscopic intervention.

Balloon tamponade technique and efficacy in variceal haemorrhage

BACKGROUND

The option of using direct compression to arrest haemorrhage from an oesophageal varix was introduced by Westphal in 1930. Since then, different types of oesophageal and or gastric balloons have become available for use. The published data concerning the efficacy and complications of the balloon tamponade in the treatment of variceal haemorrhage is evaluated. METHOD-RESULTS: Balloon tamponade as a single therapy may control initial variceal haemorrhage in more than 80% of cases. However, haemostasis is usually transient and is associated with a high rate of complications. As regards the comparison of balloon tamponade with vasoactive drugs such as vasopressin alone or vasopressin + terlipressin or terlipressin + nitroglycerin, it appears that both regimens are comparable in respect to initial control of bleeding, rebleeding, mortality, and complications. There is also evidence suggesting that balloon tamponade is as equally effective as octreotide and somatostatin in the initial control of variceal haemorrhage, but early rebleeding and complications are significantly less with the administration of both drugs. Finally, it appears that balloon tamponade is inferior to endoscopic sclerotherapy in both the acute and the long-term control of variceal haemorrhage.

CONCLUSIONS

Balloon tamponade should be reserved for those patients with variceal haemorrhage in whom bleeding continues despite conservative treatment, or as the first form of treatment only if sclerotherapy is not available.

Octreotide decreases canine gastric mucosal blood flow: a controlled assessment by endoscopic reflectance spectrophotometry

The aim of this study was to evaluate the effects of octreotide, a long-acting somatostatin analogue, on canine gastric mucosal blood flow and hemodynamics. We hypothesized that octreotide might decrease gastric mucosal blood flow without causing adverse hemodynamic effects. Two groups of dogs were anesthetized (six normal dogs and six dogs with prehepatic portal hypertension), and each dog was administered intravenous octreotide, normal saline solution, and vasopressin for 30 minutes on separate days in a blinded, randomized fashion. Vasopressin was included as treatment for a positive control. Gastric mucosal blood flow was assessed at the fundus, corpus, and antrum by endoscopic reflectance spectrophotometry. A femoral arterial catheter monitored systemic blood pressure and heart rate. Treatment responses for all observations were calculated for each dog as a percentage of baseline values. For mucosal blood flow, treatment responses did not differ significantly over time or between animal group or gastric location. Octreotide significantly decreased indices of hemoglobin concentration (-19%, p = 0.01) and oxygen saturation (-17%, p = 0.0002) compared to saline (-9% and -7%, respectively). The mean arterial pressure was increased after octreotide compared to saline (+23% versus +7%, p = 0.01), but octrotide had no effect on heart rate (+2% versus +1%). Vasopressin also decreased the indices of hemoglobin concentration (-34%) and oxygen saturation (-82%) significantly more than saline (p = 0.001). Vasopressin increased mean arterial pressure (+55%), but also caused reflex bradycardia (-22%) significantly more than saline (p = 0.001). We conclude that octreotide decreases canine gastric mucosal blood flow and appears to cause minimal hemodynamic changes.

A randomized controlled trial comparing octreotide and vasopressin in the control of acute esophageal variceal bleeding

This randomized controlled trial was conducted to compare the efficacy of intravenous infusion of octreotide (a synthetic long-acting somatostatin analogue) with vasopressin in 48 cirrhotic patients with endoscopically proven bleeding esophageal varices. Twenty-four patients received a continuous infusion of octreotide 25 micrograms/h for 24 h after an initial bolus of 100 micrograms and another 24 patients received a continuous infusion of vasopressin 0.4 U/min for 24 h. Bleeding was initially controlled after 6 h of drug infusion in 88% (21/24) and 54% (13/24) of the patients treated with octreotide and vasopressin respectively (p = 0.03). Complete control of bleeding after 24 h of drug infusion was achieved in 15 (63%) patients receiving octreotide and in 11 (46%) patients receiving vasopressin (p > 0.05). Side effects during drug infusion such as headache, chest pain and abdominal pain were significantly lower in the octreotide group (3/24) than in the vasopressin group (11/24). Serum gastrin and insulin levels fell significantly following octreotide infusion, but plasma glucose levels remained unchanged. Mortality related to bleeding esophageal varices was no different between the two groups. This report showed that octreotide infusion was more effective and had fewer side effects than vasopressin in initial controlling of acute esophageal variceal bleeding until an elective endoscopic sclerotherapy could be performed.

Review article: the pathophysiology and pharmacological treatment of portal hypertension

The pathogenesis of portal hypertension remains poorly understood. Similarly, pharmacological manipulation for the prevention and treatment of variceal haemorrhage has not fulfilled the promise of the 1980s. This article reviews current concepts in the pathophysiology of portal hypertension and considers pharmacotherapy for the treatment of variceal bleeding.

Terlipressin vs. somatostatin in bleeding esophageal varices: a controlled, double-blind study

Fifty episodes of bleeding from esophageal or gastric varices in 33 patients with cirrhosis were randomized to treatment with either intravenous terlipressin (2 mg initially and 1 mg every 4 hr for 24 hr together with bolus injection and continuous infusion of placebo) or with somatostatin (250 micrograms as a bolus and continuous infusion of 250 micrograms/hr somatostatin for 24 hr and placebo injections). Standard therapy with transfusions, fluid and electrolyte correction and lactulose was administered in both groups. In the terlipressin group, 22 of 25 bleeding episodes (88%) were initially stopped by the vasoactive drugs, and in the somatostatin group 19 of 25 bleeding episodes (76%) were initially stopped by the vasoactive drugs. Two of the three bleeding episodes not arrested by terlipressin and five of the six bleeding episodes not arrested by somatostatin were controlled by balloon tamponade. In one patient in each group variceal bleeding initially could not be stopped, and the patients died. The failure rate of the vasoactive treatment alone, including rebleeding episodes within the study period, was 20% in the terlipressin group and 32% in the somatostatin group. The control rate, including balloon tamponade, was 96% in both groups. The hospital mortality rate was 16% (4 of 25) in the terlipressin group and 24% (6 of 25) in the somatostatin group. Blood transfusions, use of balloon tamponade and duration of bleeding did not differ significantly.(ABSTRACT TRUNCATED AT 250 WORDS)

Issues in gastrointestinal endoscopy: oesophageal varices: inject, band, medicate, or operate

Injection sclerotherapy is the most widely used definitive treatment of acute variceal bleeding and is increasingly performed at the time of the first emergency endoscopy. Direct endoscopic ligation of varices by banding is a new technique under evaluation for both acute bleeding varices and long-term management. Repeated injection sclerotherapy is one of the major options for long-term management after variceal bleeding. More major surgical procedures are usually reserved for the failures of sclerotherapy in the management of acute variceal bleeding, whereas portosystemic shunts, particularly the distal splenorenal shunt, or an extensive devascularization and transection operation are commonly used alternative forms of therapy in long-term management. All patients with variceal bleeding should be assessed for liver transplantation, although only a few will ultimately receive a liver transplant. Medication with propranolol is widely recommended in long-term management, but its use in this context remains controversial. The most controversial area of management is prophylactic treatment before variceal bleeding. Major surgical procedures and injection sclerotherapy are not justified at present because it is difficult to identify those patients with a high likelihood of a first variceal bleed. Although medical therapy with propranolol has proved the most successful therapy to date, a case is made for treating most patients conservatively until their first variceal bleed occurs or until better predictive indices for patients at high risk of a first bleed are identified.

The therapeutic role of octreotide in the management of surgical disorders

The long-acting somatostatin analogue, octreotide, has recently been made available for clinical use in the United States. This novel synthetic peptide possesses a broad spectrum of physiologic actions primarily involving the inhibition of a variety of gastrointestinal and endocrine functions. Such actions have been utilized in the management of a variety of surgical disorders. Current understanding of the indications and efficacy of this agent in the treatment of surgical disease is reviewed.

Future medical prospects for Sandostatin

Because of its widespread distribution within the nervous system and gastroenteropancreatic (GEP) system, and its diverse physiological inhibitory actions on various gastrointestinal functions, including endocrine and exocrine secretion, motility, liver and splanchnic blood flow and absorption, native somatostatin has been viewed as a possible therapy for many diseases. However, its short duration of action and consequent limited clinical usefulness have been overcome with the availability of Sandostatin (octreotide, Sandoz Ltd), a long-acting, synthetic octapeptide analog of the naturally occurring hormone. Sandostatin represents a significant advance in the treatment of growth hormone (GH) and thyrotropin (TSH)-secreting pituitary tumors and GEP endocrine tumors (carcinoid tumor, VIPoma, glucagonoma, insulinoma, and gastrinoma). Preclinical in vitro and animal studies have shown the antineoplastic activity of the compound. Moreover, because of a possible direct effect on somatostatin receptor-positive endocrine tumor cells and an indirect effect whereby Sandostatin lowers GH, insulin-like growth factor type 1 (IGF-1), and numerous gastrointestinal peptides, Sandostatin may prove useful as an adjunctive therapy in cancer patients. In vivo labeling of somatostatin receptor-positive tumors with radiolabeled somatostatin analogs now allows localization of such tumors and their metastases. In addition, targeted irradiation of these tumors by beta particle-emitting isotopes attached to such somatostatin analogs may become possible. The use of Sandostatin in acute esophageal variceal bleeding, pancreatic pseudocysts, gastrointestinal, and pancreatic external fistulae, short bowel syndrome, dumping syndrome and acquired immunodeficiency syndrome (AIDS)-related refractory hypersecretory diarrhea has provided encouraging results.(ABSTRACT TRUNCATED AT 250 WORDS)