Morphometric study of the esophageal mucosa in cirrhotic patients with variceal bleeding

Does gastroesophageal reflux have an influence on bleeding from esophageal varices?

BACKGROUND

Mucosal breaks induced by gastroesophageal reflux of gastric contents were more frequently found on the right anterior wall of the lower esophagus. Bleeding from esophageal varices may be also derived from gastroesophageal reflux. The circumferential location of the ruptured esophageal varices was evaluated to elucidate the relationship between gastroesophageal reflux and variceal rupture.

METHODS

Between January 2004 and December 2006, 26 patients who had primary bleeding from esophageal varices and 74 patients without evidence of bleeding with positive red color signs on varices were enrolled in this study retrospectively. Locations of bleeding spots and nonbleeding red color signs of esophageal varices were retrospectively evaluated by endoscopic photographs, and the relationship between the location of red color signs and the risk of bleeding was evaluated. Other possible predictors for bleeding were also investigated by multivariate regression analysis.

RESULTS

Red color signs were frequently found in the right posterior wall of the lower esophagus. However, bleeding spots of esophageal varices were more frequently seen in the right anterior side (64.0%) than in others. The positive predictor for bleeding from esophageal varices was the presence of red color sign in the right anterior wall of the esophagus, and the administration of proton pomp inhibitor was the negative predictor.

CONCLUSIONS

Gastroesophageal acid reflex may be a risk factor of bleeding from esophageal varices. Attention should be paid to the circumferential location of red color signs in endoscopic screening of patients with esophageal varices to predict future bleeding.

An evidence-based approach to the treatment of esophageal variceal bleeding

Esophageal varices are a life threatening cause of gastrointestinal bleeding. Management includes both primary prevention of variceal bleeding and treatment of actively bleeding varices. Evidence from randomized controlled trials indicates that beta blockers and nitrates may prevent the initial episode of bleeding varices. Ample data from randomized controlled trials indicate that band ligation is more effective than scleropathy for the treatment of bleeding esophageal varices. Somatostatin may decrease rebleeding rates with or without endoscopic therapy. No effective treatment has been developed for the treatment of patients who fail endoscopic therapy.

Chaos and predicting varix hemorrhage

Despite a wide array of mechanisms implicated in esophagogastric varix hemorrhage, predicting the onset of bleeding or even identifying the dominant factor in its causation has proved elusive. In this article we re-examine variceal pathophysiology and hypothesize that bleeding is rooted in turbulent portal system flow, a phenomenon embodied in the 'new' science of chaos and the principles of non-linear, rhythmic fluid dynamics. Analogous to forecasting the weather, predicting turbulent flow hinges on defining the initial physical conditions, and, like the field theory of quantum physics, depends on probabilities and instabilities rather than direct proportional analysis. Based on the complex regional and systemic hemodynamic forces and local physical properties underlying formation and perpetuation of esophagogastric varices, we propose, as with climatologic events, that a relatively minor or remote physiologic adjustment may set into motion a sequence of destabilizing splanchnic blood flow kinetics that ultimately causes a varix to erupt. In other words, the onset of varix bleeding derives from a sudden, erratic switch from disorganized but stable to disruptive turbulent variceal blood flow, and as a 'chaotic' phenomenon, is likely to remain for the foreseeable future highly unpredictable.

Experimental evaluation of an endoscopic balloon for manometry of esophageal varices

Measurement of pressure in esophageal varices may be performed using an endoscopic balloon technique. Improvements in this technique are described, and a complete experimental assessment of its potentials and limitations using an in vitro model consisting of an artificial esophagus containing a water-filled tube (varix) is reported. The influence of the varix diameter (3, 5, and 7 mm) and wall thickness (0.031, 0.144, and 0.256 mm) and the possible effect of the elasticity or peristalsis of the esophageal wall were investigated. Four hundred eighty pressure measurements were performed between 5 and 40 cm H2O. Linear regression analysis showed a good correlation between the pressure in the varix and that measured endoscopically (r greater than 0.9). No obvious measurement bias was found for any of the varices. Variability in pressure measurement was low in all thin-walled varices, and only in a 3-mm thick-walled varix was it found to be high [lower limit, -11.2 (1.4) cm H2O; upper limit, 6.4 (1.4) cm H2O]. Pressure measurement in a 7-mm varix was not affected by simulated peristalsis or esophageal wall elasticity. Intraobserver and interobserver reliability of measurement assessed in a series of 324 pressure measurements by three endoscopists was excellent. The authors conclude that this method may give reliable results in large and medium-sized varices and may be unaffected by peristalsis or esophageal wall elasticity. However, further assessment in vivo remains necessary.

Pathophysiology of portal hypertension and variceal bleeding

Portal hypertension results from an interaction of abnormal intrahepatic resistance and increases in portal blood flow. Intrahepatic resistance is probably multifactorial in nature and may include compression of hepatic veins by regenerating nodules, collagen deposition in sinusoids and venules, hepatocyte enlargement, and constriction of sinusoids by contractile myofibroblasts. The increase in splanchnic blood flow observed is incompletely understood, but it may involve circulating vasodilators and alteration in volume and sodium balance. The end result of these interactions is the development of increased portal pressure and portosystemic collaterals, the most important of which are esophageal varices. The rupture of esophageal varices is a devastating complication of portal hypertension. Increased portal pressure is necessary for the development and rupture of varices but apparently not sufficient, because many patients with elevated portal pressures never bleed. Presumably, local factors must be involved. Variceal wall tension is probably the best single descriptor of risk from variceal hemorrhage. The wall-tension formula unites the contributions of portal pressure, varix size, and wall thickness to variceal rupture. Lowering portal pressure, reducing varix size, and supporting varices in scar tissue may all lower the risk of hemorrhage.

Critical evaluation of a pressure-sensitive capsule for measurement of esophageal varix pressure. Studies in vitro and in canine mesenteric vessels

The accuracy and reliability of a noninvasive pressure-sensitive capsule for the endoscopic measurement of esophageal varix pressure was evaluated. Capsule pressure was correlated with direct intraluminal pressure measurements. The influence of vessel wall tension on capsule pressure was also assessed. In vitro studies demonstrated an excellent correlation (r greater than or equal to 0.94; p less than 0.001) between the pressure obtained with the capsule and intraluminal pressure over a range of vessel diameters and wall thicknesses. In vivo correlation of pressures obtained with the capsule with direct venous pressure measurements was excellent (r = 0.85). However, this correlation decreased with a decrease in vessel diameter (group 1 diameter greater than or equal to 10 mm, r = 0.95; group 2 diameter greater than or equal to 5 mm but less than 10 mm, r = 0.75; group 3 diameter greater than or equal to 3 mm but less than 5 mm, r = 0.81). This decrease in accuracy was significant (p less than 0.001) between group 1 and groups 2 and 3. In vitro and in vivo, capsule pressure variability was significantly greater (p less than 0.001) in vessels of smaller diameter. Wall tension significantly influenced capsule pressure (p less than 0.05), although this effect was only seen in large "vessels" with a diameter beyond a clinically relevant range. Therefore, despite obtaining technically acceptable capsule pressure measurements in ideal experimental conditions, the accuracy and variability of these measurements are limited by vessel size.

Gastro-oesophageal reflux and alcoholic cirrhosis. A reappraisal

The oesophageal pH was recorded for 3 h after a test-meal in 27 healthy control subjects (group I), 40 patients with alcoholic cirrhosis (group II), and 22 patients with a normal liver and symptoms of gastro-oesophageal reflux (control refluxers). Gastro-oesophageal reflux was observed in 10 of the cirrhotic patients. Marked reflux episodes lasted longer in cirrhotic refluxers than in control refluxers (P less than 0.05). The frequency of ascites, bleeding from ruptured oesophageal varices, peripheral neuropathy and hepatic encephalopathy were not significantly different according to presence or absence of reflux. Plasma concentrations of gastrin, somatostatin, motilin and vasoactive intestinal peptide (VIP) were measured in groups I and II. Fasting plasma motilin levels, and the release of motilin and of VIP after the meal were higher in group II than in group I. Basal levels and post-prandial profiles of the four peptides tested did not differ between cirrhotics with or without gastro-oesophageal reflux. We conclude that in patients with alcoholic cirrhosis: gastro-oesophageal reflux is frequent (25%) and characterized by prolonged reflux episodes; reflux is not correlated with the degree of liver failure and plays no significant role in the rupture of oesophageal varices; and raised plasma motilin and VIP levels cannot account for the high incidence of reflux in cirrhotics.

Prophylaxis of first variceal hemorrhage in patients with liver cirrhosis

Prophylaxis of bleeding from esophageal varices is a very tempting concept at first glance, especially under the assumption of a high mortality associated with first variceal hemorrhage. Up to now four different measures have been tried for prophylaxis: portacaval shunt operation, devascularization procedures, sclerotherapy, and drugs. With the exception of portacaval shunts, ongoing controlled trials show a weak trend toward reduction of variceal bleeding and prolongation of survival in selected patients with compensated cirrhosis and large varices. However, prophylaxis of first variceal bleeding must still be regarded as experimental and should be restricted to controlled clinical studies.

Portal venous-esophageal luminal pressure gradient in cirrhosis

The portal venous-esophageal luminal pressure gradient may be more important than the absolute portal venous pressure in explaining hemorrhages caused by esophageal varices. A continuous recording of portal venous pressure and the esophageal luminal pressure enabled the authors to study the gradient between these pressures in 12 cirrhotic patients with varices of different size and under different circumstances, in particular inspiration, expiration, coughing and a Valsalva maneuver. A significant increase of portal venous pressure occurred during inspiration (+15%), coughing (+77%) and Valsalva maneuver (+157%). The value of portal venous-esophageal luminal pressure gradient increased during inspiration (+38%), coughing (+90%) and Valsalva maneuver (+69%) while it decreased during expiration (-14%).

Oesophagitis in patients undergoing oesophageal transection for varices--a histological study

Thirty-one oesophageal rings from patients undergoing transection for varices were examined histologically for oesophagitis. Four cases showed neutrophil infiltration but all had recent oesophageal intubation. Fifteen patients had significant morphological epithelial changes of oesophagitis assessed by two sets of criteria. Only 4 of these patients (13 per cent) had no other likely causative factor such as recent sclerotherapy or recent insertion of a Sengstaken tube. Therefore there appears little evidence for oesophagitis as a major aetiological factor in bleeding oesophageal varices.

A controlled clinical trial of cimetidine in the recurrence of variceal hemorrhage: implications about the pathogenesis of hemorrhage

In a prospective randomized double-blind controlled trial, 51 patients, 16 with cirrhosis and 35 with extrahepatic portal hypertension all of whom presented with variceal bleeding, were given either long-term cimetidine in a dosage of 1.6 gm daily (24 patients) or placebo tablets (27 patients). Thirty-eight patients completed 2 years of treatment. For 16 patients with cirrhosis, there was no significant difference in the frequency of rebleeding between the cimetidine (62.5%) and placebo (75.0%) groups. Similarly, in 35 patients with extrahepatic portal hypertension, the frequency with which bleeding recurred in the cimetidine (37.5%) and placebo groups (36.8%) was not significantly different. Gastric acid and esophageal function studies, including basal acid output, lower esophageal sphincter pressure, esophageal acid reflux, and clearance measurements, showed no significant differences between patients with cirrhosis or extrahepatic portal hypertension both before and after variceal bleeding and in healthy control subjects. These results suggest that it is unlikely that gastric acid reflux is a significant factor in the pathogenesis of variceal hemorrhage, and cimetidine does not prevent recurrent episodes of bleeding.