Mesenteric ischemia: acute and chronic

High risk and low prevalence diseases: Mesenteric ischemia

INTRODUCTION

Mesenteric ischemia is a rare, frequently misdiagnosed, serious condition that carries with it a high rate of morbidity and mortality.

OBJECTIVE

This review highlights the pearls and pitfalls of mesenteric ischemia, including presentation, diagnosis, and management in the emergency department (ED) based on current evidence.

DISCUSSION

Mesenteric ischemia is an abdominal vascular emergency that includes superior mesenteric arterial embolism, arterial thrombosis, venous mesenteric ischemia, and non-occlusive mesenteric ischemia. It is associated with a variety of risk factors including older age, cardiovascular disease, hypercoagulable state, and end-stage renal disease. The presentation depends on the underlying pathophysiology. While arterial embolic disease may present with sudden, severe pain, the early stages of the disease and other forms can present with vague symptoms, including generalized abdominal pain, weight loss, vomiting, and diarrhea. Laboratory testing can suggest the disease with leukocytosis and elevated lactate, but normal values should not be used to exclude the diagnosis. The imaging modality of choice is triple phase computed tomography with non-contrast, arterial, and delayed phases. The initial ED management includes fluid resuscitation, symptomatic therapy, broad-spectrum antibiotics, and anticoagulation. Emergent consultation with a multidisciplinary team including diagnostic and interventional radiologists and cardiovascular and general surgeons is necessary for definitive treatment.

CONCLUSIONS

An understanding of mesenteric ischemia can assist emergency clinicians in diagnosing and managing this disease.

The radiologist's guide to duplex ultrasound assessment of chronic mesenteric ischemia

OBJECTIVE

This article reviews the relevant anatomy and physiology of the mesenteric vasculature, familiarizes the radiologist with the accepted diagnostic criteria for mesenteric artery stenosis and its role in the diagnosis of chronic mesenteric ischemia, describes Doppler imaging techniques, and provides protocols for the assessment and surveillance of the mesenteric vasculature before and after revascularization. It also discusses expected changes following revascularization and reviews common post-procedural complications.

RESULTS

Duplex sonography plays an important role in the diagnosis and management of chronic mesenteric ischemia (CMI). Establishing a successful diagnosis is dependent upon knowledge of mesenteric arterial anatomy and physiology as well as sufficient expertise in image optimization and scanning techniques. Although there has been a trend toward utilization of other noninvasive [computed tomographic angiography (CTA), magnetic resonance angiography (MRA), and invasive (digital subtraction angiography (DSA)] imaging modalities for assessment of the mesenteric vasculature, a new era of "imaging wisely" raises legitimate concerns about the effects of ionizing radiation as well as potential effects of CT and MR contrast agents. These concerns are obviated by the use of ultrasound, and recently developed techniques, such as contrast-enhanced ultrasound and vascular applications focused on the evaluation of slow flow, have revealed the vast potential of vascular ultrasound in the evaluation of chronic mesenteric ischemia.

CONCLUSION

Duplex sonography is a cost-effective and powerful tool that can be utilized for the accurate assessment of mesenteric vascular pathology, specifically mesenteric arterial stenosis, and for the evaluation of mesenteric arterial system post revascularization.

A Novel Approach for Repairing Superior Mesenteric Artery Injury During Left Nephrectomy-6-year Follow-up

OBJECTIVE

To describe a novel approach for reconstructing the superior mesenteric artery (SMA) during left nephrectomy and review the literature.

MATERIALS AND METHODS

The patient was a 57-year-old man with left back pain from an unknown cause for more than 3 hours. A computed tomography scan showed a 12- × 15-cm firm mass and a subcapsular hematoma in the left kidney. It was considered to be bleeding and rupture of the solid renal mass, and because of persistent pain and no documented distant metastatic disease, a transperitoneal laparoscopic nephrectomy was elected, but the procedure was converted to open surgery for SMA injury. We reconstructed the SMA with end-to-end anastomosis between the SMA and the left renal artery stump.

RESULTS

At the 6-year follow-up, the patient had no intestine-related sequelae.

CONCLUSION

Our novel approach of an end-to-end anastomosis between the SMA and the left renal artery stump is an option for SMA injury, especially when orthotopic anastomosis or repair of the SMA is not indicated.

Duplex ultrasound in the early diagnosis of acute mesenteric ischemia: a longitudinal cohort multicentric study

OBJECTIVE

Acute mesenteric ischemia (AMI) is a life-threatening condition requiring time-dependent treatment; thus, early recognition may improve outcomes. We hypothesized that clinician-performed mesenteric vessels duplex ultrasound (DUS) could facilitate early identification of patients with AMI in high-risk patients presenting with abdominal pain.

METHODS

This was a single-operator, observational, prospective cohort study. Patients aged at least 65 presenting to Emergency Departments with acute abdominal pain and no clear diagnosis after an initial work-up were enrolled. All patients underwent multidetector computed tomography and these findings provided the reference standard in this study. DUS of the celiac artery and superior mesenteric artery (SMA) were obtained to measure the peak systolic velocity (PSV) and were performed within 24 h of admission. PSVs outside the normal range were considered to indicate AMI.

RESULTS

Of 49 patients identified, 47 were consented to enrollment and diagnostic images were obtained in 45 (96%). Fifteen patients (33%) had AMI (six occlusive, nine nonocclusive disease). Among these, 12 (80%) had abnormal DUS velocities. SMA PSV showed a sensitivity of 78.57% [95% confidence interval (CI): 49.2-95.34], a specificity of 64.52% (95% CI: 45.37-80.77), a positive predictive value of 50% (95% CI: 28.22-71.78), and a negative predictive value of 86.96% (95% CI: 66.41-97.22) for AMI. DUS had a sensitivity of 100%, a specificity of 64%, and a negative predictive value of 100% for occlusive AMI. Assessment of celiac artery PSV did not improve diagnostic performance.

CONCLUSION

In this single-operator pilot study, mesenteric vessel DUS was performed successfully in the Emergency Department, with a high proportion of diagnostic images obtained. A normal SMA PSV was associated with a low risk of occlusive AMI.

Acute superior mesenteric artery occlusion complicated by basilar artery occlusion

Acute mesenteric ischemia is a rare cause of abdominal pain with a very high mortality rate. Vague presentation and often misleading clinical findings make the diagnosis elusive. Here, a unique case of complete superior mesenteric artery occlusion further complicated by basilar artery occlusion is illustrated.

Prognostic factors in patients with acute mesenteric ischemia

OBJECTIVE

Acute mesenteric ischemia, one of the causes of acute abdominal pain due to occlusion of the superior mesenteric artery, has a fatal course as a result of intestinal necrosis. There is no specific laboratory test to diagnose acute mesenteric ischemia. The basis of treatment in cases of acute mesenteric ischemia is composed of early diagnosis, resection of intestinal sections with infarction, regulation of intestinal blood flow, second look laparotomy when required, and intensive care support. The aim of this study is to investigate the factors affecting mortality in patients treated and followed-up with a diagnosis of acute mesenteric ischemia.

MATERIAL AND METHODS

Forty-six patients treated and followed-up with a diagnosis of acute mesenteric ischemia between January 1st, 2008 and December 31st, 2014 at the General Surgery Clinic of our hospitalwere retrospectively evaluated. The patients were grouped as survivor (Group 1) and dead (Group 2). Age, gender, accompanying disorders, clinical, laboratory and radiologic findings, duration until laparotomy, evaluation according to the Mannheim Peritonitis Index postoperative complications, surgical treatment applied, and type of ischemia and outcome following surgery were recorded.

RESULTS

A total of 46 patients composed of 22 males and 24 females with a mean age of 67.5±17.9 and with a diagnosis of mesenteric ischemia were included in the study. Twenty-seven patients died (58.7%) while 19 survived (41.3%). The mean MPI score was 16.8±4.7 and 25.0±6 in Group 1 and Group 2, respectively, and the difference between the two groups was statistically significant (p<0,001). Fourteen of the 16 (51.9%) patients who had a Mannheim Peritonitis Index score of 26 or higher died while two of them survived (10.5%). Thirteen out of the 30 (48.1%) patients with a Mannheim Peritonitis Index score of 25 or lower died while 17 (89.5%) patients survived. The increased MPI score was significantly correlated withmortality (p=0.004).

CONCLUSION

Suspicion of disease and early use of imaging in addition to clinical and laboratory evaluations are essential in order to decrease mortality rates in acute mesenteric ischemia. Prevention of complications with critical intensive care during the postoperative period aids in decreasingthe mortality rate. In addition, using the Mannheim Peritonitis Index can be helpful.

Ascending Aorta to Hepatic and Mesenteric Artery Bypassing, in Patients with Chronic Mesenteric Ischemia and Extensive Aortic Disease-A Case Report and Review of the Literature

Chronic mesenteric ischemia (CMI) is a rare disorder caused by severe stenosis of the mesenteric arterial supply that results in postprandial pain and weight loss. Treatment options are surgical or endovascular. Surgical bypass can be performed in an antegrade fashion from the supraceliac abdominal aorta (AA) or the distal descending thoracic aorta or in a retrograde fashion from the infrarenal aorta or the common iliac artery. However, in some patients with disease of the descending thoracic aorta or the AA, another site for the proximal anastomosis needs to be found. In this article, we report the case of a 69-year-old man with a thoracoabdominal aortic aneurysm and CMI in whom we performed bypass grafts to the hepatic and superior mesenteric arteries using the ascending aorta as the site for the proximal anastomoses via a median sternolaparotomy. In addition, we performed a literature review of all similar cases and provide an analysis of this technique and an assessment of the success rates.

Management of Loose, Frequent Stools and Fecal Incontinence in a Chronic Mesenteric Ischemia Patient with Oral Serum-derived Bovine Immunoglobulin

AIM

Chronic diarrhea with fecal incontinence (FI) is a severe, underreported, and intractable problem in many patients for which limited pharmaceutical options exist.

METHODS

A retrospective case history was collected after the administration of a prescription medical food composed of serum-derived bovine immunoglobulin/protein isolate (SBI) at 5 g once daily in a patient with chronic mesenteric ischemia (CMI) for chronic loose, frequent, and urgent stools. The patient was an 84-year-old white male with a 20-year history of progressively worsening chronic diarrhea with six to eight watery stools per day (Bristol Stool Form Scale, Type 7), urgency, nocturnal diarrhea, FI, and postprandial abdominal discomfort before administration of SBI.

RESULTS

After four weeks of SBI administration, the patient had two to three soft, semi-formed stools (Bristol Stool Form Scale, Types 4 and 5) per day with no nocturnal diarrhea, urgency, or FI, as well as full resolution of abdominal discomfort. In addition, the patient expressed an enhanced quality of life (QoL): able to travel, attend social events, and perform tasks not possible before therapy.

CONCLUSION

This case underscores how a safe, nutritional therapy may offer a new modality for physicians to address chronic loose, frequent stools with FI in patients with CMI in this difficult to manage gastrointestinal population.

Protective effects of thymoquinone and melatonin on intestinal ischemia-reperfusion injury

BACKGROUND/AIM

In the present study, we aimed to compare the potential protective effects of thymoquinone and melatonin by using equivalent dose, on oxidative stress-induced ischemia-reperfusion (IR) injury in the intestinal tissue of rats.

MATERIALS AND METHODS

The study was performed using 32 male Wistar-Albino rats (weighing 180-200 g) randomly divided into four groups: Group I, sham group; Group II, IR group; Group III, IR with melatonin group; and Group IV, IR with thymoquinone group. After laparotomy, ischemia and reperfusion were performed for 60 and 120 min, respectively, on all the groups. Intestinal tissue sections were stained using routine histological methods and examined under the light microscope. In addition, the sections were immunohistochemically stained using the TUNEL method for determination of apoptosis. Superoxide dismutase (SOD) activity, glutathione peroxidase (GSH-Px) activity, and malondialdehyde (MDA) levels in the intestinal tissue were also measured.

RESULTS

The IR group had significantly elevated tissue SOD activity, GSH-Px activity, and MDA levels compared with the sham group. Administration of thymoquinone and melatonin efficiently reduced these increases. Statistically significant number of apoptotic cells was observed in the intestinal tissue of IR group rats compared with the sham group. Treatment with thymoquinone and melatonin markedly reduced the number of apoptotic cells.

CONCLUSION

The effects of melatonin and thymoquinone on IR-induced oxidative stress in rat intestines were similar. Our findings suggest that melatonin and thymoquinone protect against IR-induced injury to intestinal tissues.

Risk factors effecting mortality in acute mesenteric ischemia and mortality rates: a single center experience

The objective of this study is to discuss the effective factors on morbidity and mortality in patients who were operated on for acute mesenteric ischemia. Between 2006 and 2011, 95 patients, who underwent emergent surgery for acute mesenteric ischemia, were analyzed retrospectively. The study group consisted of 56 men (58.9%) and 39 women (41.1%), with an average age of 68.4 ± 14.4 years. Elapsed time between the onset of the symptoms and the surgical operation was less than 24 hours in 47 (49.5%) cases, and more than 24 hours in 48 cases (50.5%) (P < 0.001). Although all of the patients had intestinal necroses, colon involvement was seen in 38 patients, and mortality was higher in this group of patients (P < 0.001). Mortality rate was 42.1%. This was higher in older patients, those with increased leukocyte levels, increased elapsed time to laparotomy, and when the colon was involved.

Serum intestinal fatty acid binding protein and phosphate levels in the diagnosis of acute intestinal ischemia: an experimental study in rabbits

BACKGROUND

Acute intestinal ischemia is a serious clinical disorder with mesenteric infarction, which has high mortality. It is important to establish a biochemical marker for the early diagnosis of acute intestinal ischemia.

OBJECTIVES

The aim of this experimental study was to assess the changes in the serum levels of intestinal fatty acid binding protein (IFABP) and phosphate by time using the acute intestinal ischemia model in rabbits.

METHODS

In this study, 21 New Zealand rabbits were randomly divided into three groups. Blood samples were obtained at 0, 1, 3, and 6 h in the control group. Blood samples were obtained at 0, 1, 3, and 6 h in the sham group after simple laparotomy. Blood samples were obtained at the same hours in the ischemia group after simple laparotomy and ligation of the superior mesenteric artery.

RESULTS

There was no significant difference between the control, the sham, and the ischemia groups in terms of serum IFABP levels at any time (p > 0.05). Serum phosphate levels significantly increased in the ischemia group (p < 0.001). Studies on IFABP have begun emerging in the literature, and there is no standard approach for the technique to measure the IFABP level. No studies on IFABP were found in the literature on rabbits.

CONCLUSION

Based on our results, the role that IFABP levels play in the diagnosis of acute intestinal ischemia is unclear at this time. Serum phosphate levels continued to rise as the duration of ischemia was prolonged. These findings support the suggestion that serum phosphate levels are valuable for the diagnosis of acute intestinal ischemia.

Chronic mesenteric ischemia

Clinical manifestations of chronic mesenteric ischemia (CMI) can range from vague abdominal pain to debilitating states of intestinal angina resulting in significant weight loss and morbidity. Once the condition has been diagnosed, treatment usually is elective, except in rare cases of rapid progression to acute mesenteric ischemia. Medical management of CMI is mostly supportive. However, in disorders of coagulation, antiplatelet agents and warfarin may be helpful to prevent further thrombosis, and these disorders may require lifelong therapy. For decades, the mainstay of therapy for CMI has been surgery. Extensive disease often requires complete revascularization, although bypass of the superior mesenteric artery alone also has been shown to be effective. Multiple variations of surgical bypass have been advocated but require further evaluation to determine efficacy. Transaortic endarterectomy is a viable option for limited disease. Minimally invasive vascular procedures such as percutaneous endovascular angioplasty and stenting are proving to be effective for short-segment atherosclerotic stenosis, particularly near the origin of the vessels. Although endovascular therapy has less long-term durability compared with open surgical procedures, these treatments prove simpler, with shortened hospital stays and reduced morbidity. Furthermore, angiographic therapy is a feasible alternative for patients in whom surgery is deemed precarious.

[Diagnosis and management of acute mesenteric ischemia]

The prevalence of significant splanchnic arterial stenoses is increasing, but remains mostly asymptomatic due to abundant collateral circulation. Acute insufficiency of mesenteric arterial blood flow accounts for 60 to 70% of cases of mesenteric ischemia and results mostly from a superior mesenteric embolus. Despite major advances have been achieved in understanding the pathogenic mechanisms of bowel ischemia, its prognosis remains dismal with mortality rates about 60%. The diagnosis of acute mesenteric ischemia depends upon a high clinical suspicion, especially in patients with known risk factors. Rapid diagnosis is essential to prevent intestinal infarction. However, early signs and symptoms of mesenteric ischemia are non specific, and definitive diagnosis often requires radiologic examinations. Early and liberal implementation of angiography has been the major advance over the past 30 years which allowed increasing diagnostic accuracy of acute mesenteric ischemia. CT and MR-based angiographic techniques have emerged as alternatives less invasive and more accurate to analyse splanchnic vessels and evaluate bowel infarction. The goal of treatment of patients with acute mesenteric ischemia is to restore intestinal oxygenation as quickly as possible after initial management that includes rapid hemodynamic monitoring and support. Surgery should not be delayed in patients suspected of having intestinal necrosis.

A rare cause of chronic mesenteric ischemia from fibromuscular dysplasia: a case report

Introduction

Chronic mesenteric ischemia is a condition that is classically associated with significant atherosclerosis of the abdominal arteries, causing postprandial abdominal pain out of proportion to physical examination. The abdominal pain is exacerbated after meals due to the shunting of blood away from the intestines to the stomach, causing relative ischemia. More than 95% of chronic mesenteric ischemia cases are due to atherosclerosis. We report the first known case of chronic mesenteric ischemia from fibromuscular dysplasia. To the best of our knowledge, this is also the first known case in the literature where postprandial abdominal pain was the presenting symptom of fibromuscular dysplasia.

Case presentation

A 44-year-old Caucasian woman with a history of hypertension and preeclampsia, who had taken oral contraceptive pills for 15 years, presented with an intractable, colicky abdominal pain of two weeks duration. This abdominal pain worsened with oral intake. It was also associated with diarrhea and vomiting. Physical examination revealed stage III hypertension out of proportion to her risk factors and diffuse abdominal pain without peritoneal signs. An abdominal computed tomography scan, completed in the emergency room, revealed nonspecific colitis. Laboratory work revealed leukocytosis with a left shift, an erythrocyte sedimentation rate of 79 and a C-reactive protein level of 100. She was started on intravenous flagyl and intravenous ciprofloxacin. However, all microbial cultures were negative including three cultures for clostridium difficile. Urine analysis revealed nephritic range proteinuria. The laboratory profile was within normal limits for perinuclear-anti-neutrophil cytoplasmic antibody, cytoplasmic-anti-neutrophil cytoplasmic antibody, anti-saccharomyces cerevisiae antibody, antinuclear antibody test, celiac profile, lactate, carbohydrate antigen-125 and thyroid stimulating hormone. A colonoscopy was completed, which revealed diffuse colonic lymphoid reactive hyperplasia. A small bowel series was negative for any inflammation. An indium scan, pan-computed tomography scan and transvaginal ultrasound were also negative. Magnetic resonance angiography of her abdomen revealed proximal superior mesenteric artery stenosis, which was confirmed by computed tomography angiogram findings of severe proximal and distal superior mesenteric artery stenosis, consistent with the appearance of fibromuscular dysplasia on angiography in the absence of vasculitis or atherosclerotic disease. The patient's superior mesenteric artery stenosis was subsequently angioplastied suboptimally and had to be stented with an Angioplus stent. One month after she was admitted, her abdominal pain and tolerance to oral feeds improved tremendously.

Conclusion

Fibromuscular dysplasia most commonly presents with renal artery stenosis, which rarely causes abdominal pain. This case illustrates how fibromuscular dysplasia can present as a rare cause of chronic mesenteric ischemia, similar to chronic mesenteric ischemia from atherosclerosis.

Intestinal ischemia: current treatment concepts

PURPOSE

Mesenteric ischemia is a condition well-known among physicians treating patients with abdominal symptoms. Even so, mortality rates have not decreased significantly over the last decades. The purpose of this article is to review current treatment concepts of acute and chronic mesenteric ischemia.

RESULTS

Early diagnosis is one of the most important features that determine a patient's prognosis. Conventional angiography and multidetector computed tomography are therefore appropriate to quickly diagnose mesenteric ischemia, the latter being commonly more available. Once a patient presents with signs of peritonitis, instant laparotomy is indicated, and infarcted bowel segments need to be resected, followed by a second-look operation if necessary. If bowel necrosis is clinically not suspected, different approaches should be applied according to source and nature of mesenteric ischemia. Besides established surgical treatment concepts, more and more interventional procedures are developed and evaluated. However, superiority of these new techniques could only be shown for selected patient groups so far. In chronic mesenteric ischemia, interventional approaches seem to be an attractive alternative in patients who are in a condition too bad to undergo surgery. Patients with colonic ischemia are treated best in a conservative manner and by resolving the underlying cause, if identified.

CONCLUSION

Patients with acute mesenteric ischemia are still at highest risk for a fatal course of disease. New diagnostic and therapeutic developments have not been tested in larger studies yet, neither has any of these methods led to an increased survival in studies published so far. Taken together, mesenteric ischemia requires high awareness, earliest possible diagnosis, and treatment by an experienced interdisciplinary team of gastroenterologists, radiologists, and surgeons.

Serum ischemia-modified albumin levels in an experimental acute mesenteric ischemia model

OBJECTIVES

This experimental study aimed to assess the changes in the levels of serum ischemia-modified albumin (IMA) and interleukin-6 (IL-6) by time in cases of acute mesenteric ischemia due to superior mesenteric artery occlusion.

METHODS

Twenty-one New Zealand rabbits were randomly divided into three groups. Blood samples were collected at hours 0, 1, 3, and 6 from animals in a control group; a sham group following a simple laparotomy; and in an ischemia group following superior mesenteric artery ligation. All blood samples were analyzed for serum IMA and IL-6 levels, and then the time-dependent changes of biomarkers were investigated.

RESULTS

The serum IMA levels of the ischemia group at hours 3 and 6 were significantly higher than those of the control and sham groups (hour 3, p = 0.017; hour 6, p = 0.001). The increase in serum IL-6 levels in the ischemia group at hours 1, 3, and 6 compared to the control and sham groups was also significant (hour 1, p = 0.002; hour 3, p = 0.003; hour 6, p = 0.003).

CONCLUSIONS

IMA may be helpful as a marker in the diagnosis of acute mesenteric ischemia; however, its diagnostic value and use as a routine biochemical test should be assessed in further studies.

Abdominal angina

Abdominal angina is an underrecognized cause of postprandial abdominal pain and weight loss. Diagnosis is often delayed and requires both a careful exclusion of more common causes and a high degree of clinical suspicion, based on the patient's age, the coexistence of multiple risk factors for atherosclerosis, and the presence of vasculopathy in other districts. Appropriate investigations include duplex ultrasound, traditional angiography, magnetic resonance angiography, computed tomography angiography, and tonometry. The purpose of this review is to discuss the pathophysiology and clinical presentation of chronic mesenteric ischemia and to suggest a diagnostic flowchart for this complex condition.

Abdominal angina due to recurrence of cancer of the papilla of Vater: a case report

Introduction

Abdominal angina is usually caused by atherosclerotic disease, and other causes are considered uncommon. This is the first report of a case of abdominal angina secondary to neoplastic vascular stenosis caused by local recurrence of an adenocarcinoma of the papilla of Vater.

Case presentation

An 80-year-old woman of Caucasian origin presented with abdominal pain and diarrhea. She had undergone a pancreaticoduodenectomy for adenocarcinoma of the papilla of Vater four years earlier. Computed tomography revealed a mass surrounding her celiac trunk and superior mesenteric artery. Her abdominal pain responded poorly to analgesic drugs, but disappeared when oral feedings were withheld. A duplex ultrasonography of the patient's splanchnic vessels was consistent with vascular stenosis. Parenteral nutrition was started and the patient remained pain free until her death.

Conclusion

Pain relief is an important therapeutic target in patients with cancer. In this case, abdominal pain was successfully managed only after the ischemic cause had been identified. The conventional analgesic therapy algorithm based on nonsteroidal anti-inflammatory drugs and opioids had been costly and pointless, whereas the simple withdrawal of oral feeding spared the patient of the discomfort of additional invasive procedures and allowed her to spend her remaining days in a completely pain-free state.

Mesenteric ischemia: still a deadly puzzle for the medical community

The main goal of this article is to update etiology, epidemiology, diagnosis, treatment and outcome of the various causes of mesenteric ischemia in order to elucidate its labyrinthine clinical riddle, by reviewing the current English medical literature. Mesenteric ischemia is a quite uncommon disorder, observed in the emergency department. It is a life-threatening vascular emergency that requires early diagnosis and intervention to restore mesenteric blood flow and to prevent bowel necrosis and patient death. Consequently, it is a vital diagnosis to make because of its high mortality rate and its thorny complications. The underlying causes vary, and the prognosis depends on the specific findings during clinical examination. Vague and nonspecific clinical findings and limitations of diagnostic studies make the diagnosis a significant challenge. The prognosis of acute mesenteric ischemia of any type is grave. The complications following this medical jigsaw puzzle are also severe. Patients in whom the diagnosis is missed until infarction occurs have a mortality rate of 90%. Even with good treatment, up to 50-80% of patients die. Survivors of extensive bowel resection face lifelong disability. Despite the progress in understanding the pathogenesis of mesenteric ischemia and the development of treatment modalities, the entity remains a diagnostic challenge for clinicians. Delay in diagnosis contributes to a high mortality rate. Early diagnosis and adequate treatment can improve the clinical outcome. Even if diagnostic modalities have improved since the first successful attempts to confront effectively this clinical entity, mesenteric ischemia still remains a lethal diagnostic enigma for the medical community.

Acute mesenteric ischaemia: facts and perspectives

Acute mesenteric ischaemia is a catastrophic abdominal emergency with an extremely high mortality rate. This article discusses the aetiology, diagnosis and treatment of acute mesenteric ischaemia with emphasis on avoidance of common errors that contribute to the poor outcome inherent to this condition.

Imaging in intestinal ischemic disorders

Intestinal ischemia and infarction are a heterogeneous group of diseases that have as their unifying theme hypoxia of the small bowel or colon. The incidence of bowel ischemia and infarction is on the rise for several reasons: the aging of the population, the ability of intensive care units to salvage critically ill patients, and heightened clinical awareness of these disorders. Improvements in diagnostic imaging techniques have greatly contributed to the earlier diagnosis of intestinal ischemia, which can have a positive influence on patient outcomes. In this article, role of radiology in the detection, differential diagnosis, and management of patients who have intestinal ischemia and infarction is discussed.

Acute abdominal vascular emergencies

Abdominal vascular emergencies are relatively uncommon, frequently catastrophic, and highly lethal. Despite improved understanding of the pathophysiology and natural history of these disorders, delays in diagnosis and treatment remain the most important factors contributing to the observed high mortality. A high index of clinical suspicion together with a sound understanding of the clinical presentation, natural history, and management of these disorders are critical to improving outcomes. This article focuses on abdominal vascular emergencies presenting with acute visceral ischemia or catastrophic intra-abdominal hemorrhage.

A rare case of arterial thrombosis in a 37-year-old male with Factor V Leiden mutation

BACKGROUND

The classic triad of symptoms seen in chronic mesenteric ischaemia is post-prandial pain, sitophobia (fear of food) and progressive weight loss. Patients with mesenteric ischaemia secondary to a prothrombotic state such as that rendered by the Factor V Leiden mutation, are substantially younger than the typical elderly patient in whom embolic disease triggered by atrial fibrillation is the main underlying cause.

METHOD

This is one such case report documenting arterial thrombosis in a 37-year-old male with a subsequently identified heterozygous Factor V Leiden mutation.

CONCLUSION

Factor V Leiden mutation is a contributing risk factor in cases of small bowel infarction.

Impact of etiologic factors and APACHE II and POSSUM scores in management and clinical outcome of acute intestinal ischemic disorders after surgical treatment

BACKGROUND

Acute intestinal ischemic disorder (AIID) is an uncommon vascular disease with high mortality. According to etiology, it can be categorized into three groups: arterial occlusive mesenteric ischemia (AOMI), mesenteric venous thrombosis (MVT), and nonocclusive mesenteric ischemia (NOMI). This study analyzes the effect of classification on surgical outcome.

PATIENTS AND METHODS

All AIID patients who underwent operative treatment at National Cheng Kung University Hospital between January 1989 and August 2003 were enrolled in this study. Preoperative information on these patients was compared to find predictors of outcome.

RESULTS

Data from 77 patients (49 men and 28 women, median age 70 years) were analyzed. The etiology was AOMI in 30 patients, MVT in 19 patients, and NOMI in 28 patients. Median age was younger in MVT (54 years) than in AOMI (70 years) or NOMI (72 years). In addition, MVT usually involved the jejunum (74%, versus 31% in AOMI and 46% in NOMI), whereas both AOMI and NOMI involved ileum and colon. The patients with AOMI had shorter duration of symptoms and higher ratio of underlying hypertension than those with MVT. The overall mortality rate was 53.2% (41/77). The day 1 and day 30 mortality were 0% and 10.5% in MVT, 16.7% and 30% in AOMI, and 42.9% and 67.9% in NOMI, respectively (P < 0.05). Both the etiology and the APACHE II scores were significant risk factors for day 30 and long-term mortality. The patients with NOMI had higher POSSUM physiologic scores than patients with MVT. The P-POSSUM regression equation can accurately predict mortality.

CONCLUSIONS

Patients with MVT had a more favorable prognosis, whereas those with NOMI had the worst outlook. The APACHE II and POSSUM scoring systems are useful in predicting the clinical outcome. Early diagnosis and classification of AIID patients are useful for aggressive treatment to improve the clinical outcome.

Splanchnic ischemia and reperfusion injury is reduced by genetic or pharmacological inhibition of TNF-alpha

In the present study, we used TNF-alpha receptor 1 knockout (TNF-alphaR1KO) mice to evaluate a possible role of TNF-alpha on the pathogenesis of ischemia and reperfusion injury of the multivisceral organs. Ischemia and reperfusion injury was induced in mice by clamping the superior mesenteric artery and the celiac artery for 30 min, followed thereafter by reperfusion. Sixty minutes after reperfusion, animals were killed for histological examination and biochemical studies. Injured wild-type (WT) mice developed a significant increase of ileum TNF-alpha levels, myeloperoxidase activity, and marked histological injury and apoptosis. Ischemia and reperfusion injury of the multivisceral organs was also associated with a significant mortality. Reperfused ileum sections from injured WT mice showed positive staining for P-selectin, VCAM, ICAM-1, and E-selectin. The intensity and degree of P-selectin, E-selectin, VCAM, and ICAM-1 were reduced markedly in tissue sections from injured TNF-alphaR1KO mice. Ischemia and reperfusion-injured TNF-alphaR1KO mice also showed a significant reduction of neutrophil infiltration into the intestine, a reduction of apoptosis, an improved histological status of the intestine, and survival. In addition, we investigated the effect of Etanercept, a TNF-alpha soluble receptor construct, on ischemia and reperfusion injury of the multivisceral organs. Etanercept (5 mg/kg administered i.p. 5 min prior to reperfusion) significantly reduced the inflammatory response and the ileum injury. Taken together, our results clearly demonstrate that TNF-alpha plays an important role in the ischemia and reperfusion injury and put forward the hypothesis that modulation of TNF-alpha expression may represent a novel and possible strategy.

Update in management of mesenteric ischemia

Mesenteric ischemia disorders are precipitated by a circulation insufficiency event that deprives one or several abdominal organs of adequate respiration to meet metabolic demands. Although mesenteric ischemia occurs infrequently, the mortality rate is from 60% to 100%, depending on the source of obstruction. The successful outcome is dependent upon a high index of suspicion and prompt management. We briefly review the pathophysiology and presentation of the various ischemic entities and review the current state of the art in diagnosis and treatment. Despite advances in both diagnosis and treatment, prompt diagnosis and supportive care remain critical for successful outcome. New imaging techniques, endovascular therapy and emerging research may improve our approach to this deadly condition.

Surgical and medical management of mesenteric ischemia

Acute mesenteric ischemia frequently results in bowel necrosis, which necessitates laparotomy to assess bowel viability. Reduction in mortality requires a high index of suspicion and prompt diagnosis. Bowel resection should be preceded by visceral artery revascularization. Medical management includes the use of anticoagulation, vasodilators, and the use of inhibitors of reperfusion injury. The management of chronic mesenteric ischemia largely depends on the general condition of the patient, who is often affected by malnutrition and dehydration. Surgery, although associated with greater morbidity and mortality, is more durable and effective in relieving the symptoms of chronic mesenteric ischemia. Endovascular treatment options for chronic mesenteric ischemia include percutaneous balloon angioplasty and stenting. This treatment is more likely to be successful in dealing with stenotic rather than occlusive lesions and offers a minimal invasive approach but is associated with a smaller primary success rate and a higher recurrence rate.

Diagnosis and management of ischemic colitis

The clinical presentation and outcome of ischemic colitis has a wide spectrum. Impaired perfusion of blood to the bowel from a variety of causes is the underlying pathophysiology. The presence of diarrhea, abdominal pain, and mild lower gastrointestinal bleeding should prompt consideration of ischemic colitis as a cause. Although many laboratory tests and radiographic images may suggest the diagnosis, endoscopic visualization of colonic mucosa with histologic analysis of biopsies is the gold standard for identification of colonic ischemia. Most cases are transient and resolve without any complications. Medical therapy for chronic ischemia has been anecdotally proven but not carefully studied. Complications of ischemic colitis can include bowel perforation, peritonitis, persistent bleeding, protein-losing colopathy, and symptomatic intestinal strictures. Thus, surgical resection of the affected segment should be considered early to minimize adverse outcomes. This review describes the etiology, pathophysiology, clinical features, diagnostic approach, and management of ischemic colitis.

Prognostic Factors for Mesenteric Infarction: Multivariate Analysis of 187 Patients with Regard to Patient Age

Between 1980 and 2002 a total of 187 patients (105 women, 82 men) with a mean age of 71.5 years underwent surgery for acute mesenteric infarction (AMI) in our department. Arterial occlusion was found in 140 patients, splanchnic vein thrombosis in 22, and nonocclusive AMI in 25. We performed bowel resection in 61 patients, vascular surgery in 32, a combination of the two in 15, and an exploratory laparotomy in 79. The mortality rate was 70.6% (73.9% in patients >70 years and 65.2% in those <70). AMI is still a disease with a consistently high mortality rate (60-80%). Multivariate prognostic factors include the time until surgery and a markedly elevated white blood cell count and serum lactate level. Mortality and secondary disease rates are higher in the elderly, and the fact that they have to wait much longer for an operation than younger patients may be a factor. If surgery is performed early, the survival rate increases regardless of age. The most important prognostic factor and the only one that can be influenced by the surgeon remains the time interval between the onset of symptoms and surgery, Therefore diagnostic and therapeutic intervention should be performed as early as possible in patients with suspected AMI.

Chronic mesenteric ischemia

Chronic mesenteric ischemia is an unusual but important cause of abdominal pain. Although this condition accounts for only 5% of all intestinal ischemic events, it can have significant clinical consequences. Among its many causes, atherosclerotic occlusion or severe stenosis is the most common. This disorder has an indolent course that results in extensive collateral vascular formation. Thus, symptoms occur when at least two of the three main splanchnic vessels are affected. Intestinal angina, weight loss, and sitophobia are common clinical features. Diagnosis can often be made by noninvasive methods such as computerised axial tomographic angiography, magnetic resonance angiography, and duplex ultrasonography as well as by invasive catheter angiography. Therapy of chronic mesenteric ischemia depends on the extent and location of vascular disease. Alternatives to traditional surgical bypass are becoming more common including embolectomy, thrombolysis, and percutaneous angioplasty with vascular stenting. Early intervention is vital as the natural course of this illness can be debilitating. Furthermore, this has potential to develop into life-threatening acute mesenteric ischemia with subsequent bowel infarction and death. Long-term studies have shown that the risk of developing symptoms from asymptomatic but significant mesenteric vascular disease is 86% with overall 40% mortality rate. The recognition and management of this unusual but important cause of abdominal pain is discussed in detail in this review.