Chronic mesenteric vascular insufficiency with gastric ulceration

Ischemic Gastritis: A Multicenter Case Series of a Rare Clinical Entity and a Review of the Literature

GOALS

To report a case series of ischemic gastritis and discuss its etiology, management, and associated mortality according to our results and the published English literature.

BACKGROUND

Ischemic gastritis is rare, given the rich blood supply of the stomach. It has been reported in isolated case reports and small case series. Most cases are vascular in origin and associated with a high mortality.

STUDY

Pathology databases from 3 hospitals affiliated with the University of Minnesota Medical School were searched for cases of ischemic gastritis in the last 10 years. Patients' demographics, clinical course, and 1-month and 1-year mortalities were collected from electronic medical records.

RESULTS

A total of 12 patients were identified (age range, 32.1 to 83.2), the largest series reported to date. The presenting symptom was gastrointestinal bleeding (8), abdominal pain (2), nausea (1), and symptomatic anemia (1). The etiology included postinterventional radiology embolization (2), hemodynamic changes in the setting of celiac axis stenosis (2), vasculitis (1), systemic hypotension (1), and unknown (6). Treatment included steroid therapy, revascularization by interventional radiology, surgery, or supportive treatment. Thirty-day and 1-year mortalities were 33% and 41%, respectively.

CONCLUSIONS

Ischemic gastritis is rare, but associated with a high mortality. Evaluation for treatable etiologies should be sought and corrected if present.

Superior Mesenteric Artery Dissection: Rationale for a Conservative Approach in Selected Patients

The superior mesenteric artery (SMA) is an uncommon location for spontaneous peripheral arterial dissections. In the past, most symptomatic SMA dissections were treated surgically. However, the authors recently treated a healthy 40-year-old man who experienced a symptomatic SMA dissection with anticoagulation therapy alone. The patient had bilateral internal carotid artery (ICA) dissections in the past that were also managed in a conservative fashion. To their knowledge, this is the first patient reported in the literature with both ICA and SMA dissections. In addition, he is one of only a few patients with an SMA dissection who was successfully treated without surgical intervention. From our experience with this patient and a review of the literature, we believe that a trial of anticoagulation therapy is warranted in all patients with uncomplicated, symptomatic SMA dissections.

Predictors of marginal ulcers after laparoscopic Roux-en-Y gastric bypass

BACKGROUND

Laparoscopic Roux-en-Y gastric bypass (LRYGB) is a highly effective therapy for morbid obesity. As the most common postoperative complication, marginal ulcers (MU) present a significant disease burden. The etiology of marginal ulcers after gastric bypass has not been clearly defined. The purpose of this study was to identify independent risk factors for MU.

METHODS

We performed a retrospective study of a single surgeon's experience performing LRYGB between July 2001 and January 2006 in a United States private practice and university hospital. We investigated patient factors and comorbidities associated with the development of marginal ulcers. The five most common comorbidities were hypertension, type 2 diabetes mellitus, gastroesophageal reflux disease, hyperlipidemia, and obstructive sleep apnea. We analyzed these factors using multivariate logistic regression adjusting for demographics, BMI, and all comorbidities.

RESULTS

In our 763 patients, 89% were female, 84.7% were African-American, and the mean BMI was 50.2 kg/m(2) before surgery. Marginal ulcers occurred in 23 patients (3.01%) over a mean of 64 months. On χ(2) analysis, hypertension, gastroesophageal reflux disease, hyperlipidemia, and sleep apnea were significantly correlated with MU. On multivariate analysis, the odds of marginal ulcer formation were 7.84 among hypertensive patients with a 95% confidence interval of 1.75-35.06 (P = 0.007). Hypertension was the only significant predictor of marginal ulcer disease.

CONCLUSION

In our study, marginal ulcers occurred more frequently in patients with preoperative hypertension. At higher risk, these patients could be good candidates for extended acid suppression prophylaxis after LRYGB.

[A rare cause of gastric ulcer]

Drug-induced gastrointestinal tract lesions are becoming more frequent but are generally little known. Although a large number of drugs have gastrointestinal adverse effects, there are few characteristic patterns. Acute ischemic gastritis is an uncommon entity that is rarely distinguished from other forms of intestinal ischemia. We report the case of a 69-year-old woman who was diagnosed with an unusual gastric lesion in the context of an acute exacerbation of her anemia.

Ischaemic gastric ulceration with endoscopic healing after revascularization

A 66-year-old man with a history of abdominal pain, diarrhoea and weight loss was admitted for evaluation. Gastroscopy disclosed a severe gastric ulceration covering the lesser curvature. There was none of the usual risk factors for peptic ulcer disease and no malignancy was found. After 2 weeks' treatment with a proton pump inhibitor no healing was observed. The patient had a known atherosclerotic vascular disease, and angiography disclosed severe mesenteric ischaemia. After a revascularization procedure with stenting of the superior mesenteric artery was performed, the patient's symptoms disappeared. Healing of the gastric ulceration was observed at a further gastroscopy 2 weeks later. Chronic ischaemia is a rare cause of gastric ulcer, but should be suspected when no other cause is found and when the usual treatment with proton pump inhibitors does not result in healing.

The effect of octreotide on gastroduodenal blood flow measured by laser Doppler flowmetry in rabbits and man

OBJECTIVE

The somatostatin analogue, octreotide is valuable in the management of variceal bleeding, and it has been suggested that it may stop peptic ulcer hemorrhage by reducing gastroduodenal blood flow or increasing intragastric pH. The aim of this study was to determine the effect of intravenous octreotide infusion on gastroduodenal mucosal blood flow and gastric pH.

METHODS

Seven New Zealand white rabbits and five healthy human volunteers were used. Mucosal blood flow was measured using a laser Doppler flowmeter (LDF). The Doppler probe was positioned in the upper gastrointestinal tract of the seven rabbits and five human volunteers. Blood flow was measured before and after octreotide infusion.

RESULTS

In the animal experiments, mucosal blood flow was decreased in a dose dependent manner in the gastric body (209.1-56.3 U) (p < 0.008), antrum (143.3-33.3 U) (p < 0.02) and duodenum (254-67.6 U) (p < 0.016) by doses of octreotide ranging from 10-50 microg/kg of body weight. In the human studies, mucosal blood flow was decreased in the gastric body (p < 0.016) and antrum (p < 0.009) after octreotide infusion (dose 1-1.5 microg/kg). Intragastric pH was significantly increased (p < 0.05). The change was not associated with systemic hemodynamic changes.

CONCLUSIONS

Gastroduodenal mucosal blood flow was reduced and intragastric pH increased by octreotide. This agent could be helpful in the management of gastroduodenal mucosal bleeding.

Intestinal (mesenteric) vasculopathy. II. Ischemic colitis and chronic mesenteric ischemia

Ischemic colitis accounts for approximately half of all cases of mesenteric vasculopathy. The clinical presentation varies depending on underlying cause, extent of vascular obstruction, rapidity of ischemic insult, degree of collateral circulation, and presence of comorbidity. Ischemic colitis is usually diagnosed by colonoscopy. Only approximately 20% of patients require surgery because of signs or laboratory findings of peritonitis or because of clinical deterioration. Approximately 20% of patients develop chronic colitis from irreversible colonic ischemic injury, which manifests clinically as persistent diarrhea, rectal bleeding, or weight loss and endoscopically as a colonic stricture or mass. Chronic mesenteric ischemia is almost always caused by significant atherosclerotic stenosis involving at least two mesenteric arteries, usually the superior mesenteric artery and celiac axis. The classic symptomatic triad of postprandial pain, fear of eating, and involuntary weight loss occurs with advanced disease.

Malabsorption syndrome associated with ulceration of the stomach and small bowel caused by chronic intestinal ischemia in a patient with hyperhomocysteinemia

We describe a 39-year-old woman with an 8-month history of abdominal pain, diarrhea, and weight loss. Clinical and laboratory evaluation indicated the presence of a malabsorption syndrome. Endoscopy revealed multiple gastric ulcerations and an abnormal "picture" of the duodenal mucosa. At duodenal biopsy, necrosis confined to the distal parts of the enteric villi and a polymorphonuclear leukocyte response were found. Further evaluation revealed intestinal ischemia as a result of mesenteric atherosclerosis. After a revascularization procedure was performed, the symptoms disappeared. The macroscopic and microscopic picture of the bowel normalized. In our search for risk factors of atherosclerosis, we found a substantially increased basal plasma homocysteine concentration. This case suggests that hyperhomocysteinemia may have a causal role in the development of symptomatic, premature atherosclerosis of the mesenteric circulation.

Chronic mesenteric ischaemia: diagnostic challenges and treatment options

OBJECTIVES

A description of the clinical presentation, diagnostic procedure and mode of therapy in three patients suffering from chronic mesenteric ischaemia.

DESIGN AND INTERVENTIONS

In all cases, the diagnosis was made on the basis of abdominal complaints in combination with angiographic findings. The primary treatment objective was restoration of blood flow via a revascularization procedure, for the patient in whom this could not be accomplished an enteral feeding programme was undertaken.

RESULTS

One patient had a panmalabsorption syndrome which was treated with an aortomesenteric bypass operation, the second one presented with multiple gastric ulcerations which only improved after a percutaneous transluminal angioplasty. In the third patient, neither surgery or angioplasty were feasible and a tentative enteral feeding programme was given, after which the ability to consume a normal oral diet without abdominal distress was regained.

CONCLUSIONS

These three cases illustrate the diverse clinical pictures by which chronic mesenteric ischaemia may present itself. This diagnosis should be kept in mind when other more common causes of a patient's abdominal complaints cannot be found, hence giving consideration to abdominal angiography as the next diagnostic procedure. With respect to therapy, restoring blood flow through surgery or angioplasty is the primary form of treatment. However, if neither of these therapeutic options is feasible, it is suggested that such patients may benefit from a nutritional training programme.

Factors influencing reflectance spectrophotometric measurements of gastrointestinal mucosal blood flow

Although the technique of endoscopic reflectance spectrophotometry has been applied in clinical studies, factors that modify the reproducibility of measurements have not been assessed systematically. To determine the limitations of the technique, measurements were made while endoscopic light intensity, systemic oxygen saturation, and orientation of the measuring probe were varied. The effects of hemorrhagic hypotension and exposure of the mucosa to 10% dextrose were also studied. When a large number (n = 480) of measurements in the human colon were considered, endoscopic light significantly decreased the index of oxygen saturation (ISO2) and increased the index of hemoglobin concentration (IHB). The decrease in ISO2, however, was small and unlikely to be of clinical importance despite being statistically significant. In one subject with chronic lung disease and baseline hypoxemia, administration of supplemental oxygen significantly increased oxygen saturation at the finger tip as measured by an oximeter and ISO2 of the buccal mucosa as measured by reflectance spectrophotometry. Varying the angle between the measuring probe and the gastric mucosa in rats from 90 degrees to 60 degrees did not affect ISO2 or IHB measurements. At 45 degrees, however, IHB but not ISO2 was significantly increased. Ischemia subsequent to induction of hemorrhagic hypotension and hyperemia induced by administration of 10% dextrose could be demonstrated reproducibly. We conclude that by lowering the intensity of endoscopic light and providing supplemental oxygen, errors in the measurement of IHB and ISO2, respectively, can be minimized. Minor deviations from the perpendicular orientation do not significantly affect ISO2 and IHB measurements. Attention to these details enhances the accuracy of endoscopic reflectance spectrophotometric recordings of ISO2 and IHB in clinical studies.

Endoscopic assessment of blood flow in duodenal ulcers

The importance of blood flow in duodenal ulcer healing is unclear. Endoscopic reflectance spectrophotometry measures the index of oxygen saturation (ISO2), which is significantly correlated with blood flow. In 97 consecutive patients who presented with duodenal ulcer bleeding, the difference in the index of oxygen saturation (delta ISO2: ulcer margin ISO2 minus adjacent mucosa ISO2) was determined during the initial endoscopic examination. Endoscopic examinations were repeated until the ulcers had healed (n = 86). Relative to the adjacent mucosa, 78% of the ulcer margins had increased blood flow (positive delta ISO2) and 22% had decreased blood flow (negative delta ISO2). Stepwise multi-linear regression analysis selected delta ISO2, ulcer size, and stigmata of recent hemorrhage as predictors of delayed healing. A significant negative linear correlation between delta ISO2 and ulcer healing time (r = -0.35, p < 0.001, n = 86) was demonstrated. The scatter in the data precludes prediction of ulcer healing based on delta ISO2 measurement in an individual patient. Multi-variate logistic regression analysis selected concurrent medical illness, duodenal deformity, frequent use of non-steroidal anti-inflammatory drugs, and stigmata of recent hemorrhage as factors significantly associated with delayed (longer than 5 weeks) ulcer healing. The results support the hypothesis that prognostic factors are identifiable at the time of ulcer diagnosis, even in patients who present with bleeding. Blood flow remains an equivocal factor that deserves to be re-studied taking multiple measurements around the ulcer and including a larger number of slow healers.

Lethal nature of ischemic gastropathy

Gastropathy on the basis of mesenteric arterial ischemia can be masked in presentation as the typically more benign entities of gastritis, gastric ulceration, or gastric atony. Gastritis and ulceration are commonly associated with stress, hyperacidity, Helicobacter pylori infection, or medication injury. Gastric atony is less commonly seen and usually attributable to diabetes mellitus, vagotomy, or mechanical gastric outlet obstruction. Gastric ischemia as a cause of gastropathy is an underappreciated phenomenon with a particularly poor prognosis in which early diagnosis is essential to potentially successful intervention. Seven patients with ischemic gastropathy are described; all are women, aged 41 to 71 years, smokers, with hypertension. Nausea, vomiting, weight loss, and gastrointestinal bleeding were the common presenting symptoms. All patients had endoscopic or autopsy-proven gastric ulcerations or necrosis, and two patients had proven gastroparesis. Four of five patients with ischemic gastritis died within 3 months of diagnosis despite vascular reconstruction. The two patients with gastroparesis underwent aorto-celiac bypass and are well 9 and 20 months, respectively, after operation. Treatment results were distressingly unsatisfactory, especially in those patients in whom gastritis rather than gastroparesis was the presenting problem. Although the high mortality of mesenteric ischemia is well described, little documentation of gastric ischemia exists in the literature. This entity is generally not considered in the differential diagnosis of gastritis, ulceration, or gastroparesis. Empirically, an early diagnosis and treatment may improve the survival in this select patient group.

Reproducible demonstration of blood flow at duodenal ulcer margins by endoscopic reflectance spectrophotometry

Changes in gastrointestinal mucosal blood flow were evaluated by index of oxygen saturation (ISO2) and index of hemoglobin concentration (IHB) measured with a reflectance spectrophotometer. This report examined the reproducibility of endoscopic measurements of ISO2 and IHB. Study 1: The everted stomachs of three anesthetized rats provided hands-on instruction (one teacher and three learners). Six sets of readings were obtained endoscopically (the mean calculated to give the measurement) at each level of gastric mucosal perfusion when gastric blood flow was varied by withdrawing blood from the carotid artery. Study 2: Fourteen duodenal ulcer patients with ulcer bleeding were transfused and stabilized. Two endoscopists (one teacher and one learner) took turns to obtain endoscopic ISO2 and IHB measurements at the margin of the ulcer and at the adjacent normal appearing mucosa. delta ISO2 was calculated as the ulcer margin value minus adjacent mucosa value. In study 1, the correlation coefficients between the ISO2 measurements of the experienced and those of the other three observers were 0.99, 0.97, and 0.97, respectively. In study 2, the correlation coefficients between the ISO2 measurements obtained at the ulcer margin and at the adjacent normal mucosa, and delta ISO2 obtained by the experienced observer and one of the three learners were 0.94, 0.97, and 0.94, respectively. Relative to the adjacent area, 79% of the duodenal ulcers studied had increased (+delta ISO2), and 21% had decreased blood flow (-delta ISO2) at the ulcer margins. IHB measurements were less reproducible, particularly at the ulcer margin. The measurements of ISO2 and delta ISO2 were reproducible in the everted rat stomach and in duodenal ulcer patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Peptic ulcer pathophysiology

Despite extensive research, the etiology of peptic ulcer disease remains unclear. Given the multiple processes that control acid and pepsin secretion and defense and repair of the gastroduodenal mucosa, it is likely that the cause of ulceration differs between individuals. Acid and pepsin appear to be necessary but not sufficient ingredients in the ulcerative process. It is clear that the majority of gastric ulcers and a substantial number of duodenal ulcers do not have increased gastric acid secretion. Recent research has focused more on protection and repair of the stomach and duodenum. NSAIDs cause a significant number of gastric and duodenal ulcers; this is probably due to inhibition of prostaglandin production with loss of its protective effects. In the absence of NSAIDs and gastrinoma, it appears that most gastric ulcers and all duodenal ulcers occur in the setting of H. pylori infection. Evidence is mounting in support of H. pylori as a necessary ingredient in the ulcerative process, similar to acid and pepsin. It is not known whether the bacteria or the accompanying inflammation is the more important factor in the pathophysiology. Although the pathophysiology of gastric ulcer and duodenal ulcer is similar, there are clearly differences between the two groups. Duodenal ulcer is typified by H. pylori infection and duodenitis and in many cases impaired duodenal bicarbonate secretion in the face of moderate increases in acid and peptic activity. These facts suggest the following process: increased peptic activity coupled with decreased duodenal buffering capacity may lead to increased mucosal injury and result in gastric metaplasia. In the presence of antral H. pylori, the gastric metaplasia can become colonized and inflamed. The inflammation or the infection itself then disrupts the process of mucosal defense or regeneration resulting in ulceration. A cycle of further injury and increased inflammation with loss of the framework for regeneration may then cause a chronic ulcer. Gastric ulcer often occurs with decreased acid-peptic activity, suggesting that mucosal defensive impairments are more important. The combination of inflammation, protective deficiencies, and moderate amounts of acid and pepsin may be enough to induce ulceration. Many questions remain in understanding the pathophysiology of peptic ulcer disease. The physiology and pathophysiology of mucosal regeneration and the mechanisms by which H. pylori and inflammation disrupt normal gastroduodenal function will be fruitful areas of future investigation.

Endoscopic assessment of mucosal hemodynamic changes in a canine model of gastric ulcer

In studying the side effects of sclerosants injected into the gastric submucosa in dogs (N = 7), we noted that 3 ml of absolute ethanol induced a large gastric ulceration. We describe the time course of change in the ulcer size, and suggest that such ulceration can be used for the endoscopic assessment of factors important in ulcer genesis and healing. Endoscopic reflectance spectrophotometric measurement of indices of mucosal hemoglobin concentration (IHB) and oxygen saturation (ISO2) were performed in a separate group of dogs (N = 4) with ethanol-induced gastric ulceration. We found a significant difference (p less than 0.05) in IHB and ISO2 immediately before (97 +/- 8 and 37 +/- 3, respectively) and after (138 +/- 7 and 21 +/- 5, respectively) the ethanol injection. At 24 hours after the ethanol injection, the IHB at the lesion margin (141 +/- 14) was significantly higher (p less than 0.05) than that at the adjacent mucosa (101 +/- 4), whereas the ISO2 measurements were not significantly different in these two locations, 34 +/- 2 and 31 +/- 2, respectively. We conclude that (1) injection of 3 mol of absolute ethanol into the submucosa of the canine stomach provides an animal model of gastric ulceration in which the ulcer can be examined repeatedly with the aid of the endoscope; (2) in this ulcer model, ischemia with congestion (increases IHB, decreases ISO2) precedes the development of gross mucosal ulcerations; and (3) the margin of the established ulceration in this model exhibits hyperemia (increases IHB, normal ISO2) which mimics that of a healing gastric ulcer.

Reduction in index of oxygen saturation at margin of active duodenal ulcers may lead to slow healing

This study tested the hypothesis that reduced perfusion of a duodenal ulcer margin (ie, the mucosa 1-2 mm from the edge of the ulcer base) is associated with slow healing. Reflectance spectrophotometric measurement of indices of mucosal hemoglobin concentration (IHB) and mucosal hemoglobin oxygen saturation (ISO2) were obtained endoscopically in 21 patients at the ulcer margin and the adjacent mucosa (ie, the mucosa 1-2 cm from the edge of the ulcer base). In 17 patients with adequate follow-up, stepwise multilinear regression analysis revealed a significantly negative correlation (r = -0.69, P less than 0.05) between ISO2 at the ulcer margin minus ISO2 at the adjacent mucosa (delta ISO)2 and ulcer healing time. In addition, smoking, being black, and early relapse since the last ulcer attack were found to be associated with increased duration required for healing. The results of this pilot study suggest factors, in addition to smoking, that may have to be considered in future studies concerned with duodenal ulcer healing.

Aetiology of ulcers

It seems that duodenal and gastric ulcers are caused by environmental ulcerogens, which are probably infectious or chemical. The reasons for individual susceptibility to these ulcerogens have not been defined and, indeed, it is not yet certain that the effects are not essentially random. Abnormalities of function of the mucosae of the upper alimentary tract do not appear to be necessary or sufficient for the production of ulcers. The two principal clinical aspects of ulcer disease--the tendency to form chronic mucosal wounds and the tendency of the wounds to recur during many years--point to, but cannot yet be explained in terms of, failure of the processes involved in wound repair. More specifically, it is not known whether there is interference with the processes involved in normal mucosal repair or whether there is failure of the repair processes. When these problems are closer to solution, it will perhaps be possible to assess how environmental factors influence ulcerogenesis.

Subepithelial hemorrhages and erosions of human stomach

Subepithelial hemorrhages and erosions of the stomach are being studied extensively in experimental animal models but have not been well-characterized in humans. The definitions of these hemorrhagic and erosive lesions are not uniform and are often further confused by being labeled with the blanket term "gastritis." We define these lesions from an endoscopic perspective, describe the clinical settings in which they occur, and provide endoscopic-histologic correlations, where available.

Mesenteric ischemia

Mesenteric ischemia secondary to vascular disease remains a significant problem in patients presenting with acute abdominal conditions, especially if they are elderly. Although rare, it is nevertheless an important and perhaps increasing cause of death or significant morbidity. Occasionally, it may be a mode of dying, but more often, it is the reason for death. Individual cases can manifest an almost overwhelming spectrum from chronic to acute, mild to catastrophic, arterial to venous, occlusive to hemodynamic, extensive to limited, or precisely diagnosed to accidentally found. Treatment principles are well defined, but continued refinement of supportive therapies of several types is occurring. In contrast, improved screening tests that can lead to early specific etiologic diagnosis remain at the experimental stage. Thus, good "clinical suspicion" is foremost and essential.