Nonocclusive Ischemia Research Articles

Midterm Clinical Outcomes of Retrograde Open Mesenteric Stenting for Mesenteric Ischemia

Retrograde open mesenteric stenting (ROMS) has become a mainstay in treatment of mesenteric ischemia; however, follow-up in contemporary studies is limited. A single-center retrospective review of patients undergoing ROMS from 2007 to 2020 was conducted. Demographics, presentation, and procedural details were reviewed. End points were morbidity and mortality, technical success, primary patency, reinterventions, and freedom from clinical recurrence. ROMS was performed in 34 patients, 19 female (56%). Mean age was 71±10years. Eighteen patients (53%) presented with acute mesenteric ischemia (AMI), 11 (32%) with acute-on-chronic, and 5 (15%) with chronic mesenteric ischemia. Etiology was chronic atherosclerosis with/without in-situ thrombosis in 28 patients (82%), superior mesenteric artery dissection in 3, and 1 each with embolic, vasculitic, and nonocclusive ischemia. Four patients (12%) had prior mesenteric procedures (3 Celiac/1 superior mesenteric artery stent) and 1 had unsuccessful transbrachial stenting attempt. Technical success, defined as successful stenting through a retrograde approach was attained in 31 patients (91%), with the 3 remaining patients treated with transbrachial stenting in 2 and iliomesenteric bypass in 1. Covered stents were used in 21 patients (64%) with or without stent extension with bare-metal stents. Eight patients (23%) required thromboembolectomy and 9 (26%) underwent patch angioplasty. Thirty-day mortality rate was 35%, all in patients with AMI (10) or acute-on-chronic (2). Eighteen patients (53%) underwent bowel resection, all presenting acutely. Early reinterventions within the first 30days were required in 5 patients (15%), including 2 redo ROMS with thrombectomy and endarterectomy, 2 percutaneous stent extensions, and 1 aortic septum fenestration with coiling of a jejunal branch pseudoaneurysm. With a median follow-up of 3.7 (interquartile range: 0.8-5.0) years, in patients surviving discharge, 5 required reintervention yielding freedom from reintervention rates of 87% at 1year and 71% at 3years. All postdischarge reinterventions were endovascular with no conversion to bypass. The overall 1-year and 3-year primary patency rates were 70% and 61% (primary-assisted patency at 1 and 3years was 87% and secondary patency at 1 and 3years was 97%). The freedom from symptom recurrence was 95% at 1 and 3years. ROMS carries high rates of technical success in patients with mesenteric ischemia, despite a high chronic atherosclerotic burden. Although mid-term patency rates are acceptable, AMI is still associated with high early morbidity and mortality, with high rates of associated bowel resection. ROMS is a valuable tool in the armamentarium of vascular surgeons.

Midterm Clinical Outcomes Of Retrograde Open Mesenteric Stenting For Mesenteric Ischemia

<h3>INTRODUCTION AND OBJECTIVES</h3> Retrograde open mesenteric stenting (ROMS) has become a mainstay in treatment of mesenteric ischemia, however, follow-up in contemporary studies is limited. <h3>METHODS</h3> Single-center retrospective review of patients undergoing ROMS from 2007-2020 was conducted. Demographics, presentation, procedural details were reviewed. Endpoints were morbidity and mortality, technical success, primary patency, reinterventions, and freedom from clinical recurrence. <h3>RESULTS</h3> ROMS was performed in 34 patients, 19 female (56%). Mean age was 71±10 years. Eighteen patients (53%) presented with acute mesenteric ischemia (AMI), eleven (32%) with acute-on-chronic (ACMI), and five (15%) with chronic mesenteric ischemia (CMI). Etiology was chronic atherosclerosis with/without in-situ thrombosis in 28 patients (82%), SMA dissection in three, and one each with embolic, vasculitic, and non-occlusive ischemia. Four patients (12%) had prior mesenteric procedures (3 Celiac/1 SMA stent) and one had unsuccessful transbrachial stenting attempt. Technical success, defined as successful stenting through retrograde approach was 91%; three remaining patients were treated with transbrachial stenting in two patients and iliomesenteric bypass in one. Covered stents were utilized in 21 patients(64%). Eight patients(23%) required thromboembolectomy and nine(26%) underwent patch angioplasty. Thirty-day mortality rate was 35%, all in patients with AMI (10) or ACMI (2). Eighteen patients (53%) underwent bowel resection, all presenting acutely. Early reinterventions were required in 5 patients (15%); two redo ROMS with thrombectomy and endarterectomy, two percutaneous stent extensions, one aortic septum fenestration. At a median follow-up of 3.7(0.1-8.4) years, cumulative reintervention rate was 24% (8 patients, all four late reinterventions were endovascular with no conversion to bypass), primary patency was 73%(primary-assisted patency 91%, secondary patency 97%), and freedom from clinical recurrence was 95%. <h3>CONCLUSIONS</h3> ROMS carries high rates of technical success in patients with mesenteric ischemia, despite high chronic atherosclerotic burden. While mid-term patency rates are acceptable, early mortality and bowel resection remain common in acute presentations.

Неоклюзивні порушення брижового кровотоку (огляд літератури)

Non-occlusive mesenteric ischemia is a relatively rare but extremely complex pathology in terms of diagnosis. A wide range of reasons for the development of non-occlusive impression dramatically complicates the diagnosis and differentiation with other abdominal pathology. The vast majority of publications in the domestic literature on acute disorders of mesenteric blood flow, mostly address the problems of diagnosis and treatment of occlusive types of mesenteric ischemia, while the topic of non-occlusive ischemia remains insufficiently covered. Given that in half of the cases NOMI is diagnosed at the stage of irreversible necrotic changes of the intestine – there is a real need to generalize the root causes and mechanisms of neoclustive mesenteric ischemia, modern methods of diagnosis and treatment. Purpose – to analyze of the causes, prevalence, classification, diagnosis and treatment of non-occlusive disorders of mesenteric blood flow. This research, based on literature review, showed that acute non-occlusive mesenteric ischemia (NOMI) is associated with poor prognosis due to the lack of accurate diagnostic measures. First of all, clarity regarding biochemical markers. Therefore, the research and development of the latter is seen as a priority. Contrast methods of examination (computed tomography, angiography) are the only possible diagnostic tools. Pharmacological correction is fundamental and presupposes the use of drugs with a vasodilating effect systemically or locally (catheter-associated). An important issue is the development of pharmacological agents that allow targeted action on the pathogenetic mechanisms of the development of NOMI. A multidisciplinary approach involving a specialized doctor, a surgeon, an X-ray endovascular surgeon and an intensive care physician in the treatment of a patient with suspected NOMI is the foundation for the success of therapy. The question of the use of laparoscopy remains controversial, given the invasiveness of the method and the difficulty of interpreting the changes detected in the early phase of the disease. No conflict of interests was declared by the authors. Key words: acute mesenteric ischemia, non-occlusive disorders of mesenteric blood flow.

Idiopathic Myointimal Hyperplasia of Mesenteric Veins (IMHMV) with two spontaneous bowel perforations: A case report and literature review.

Introduction and importanceIdiopathic myointimal hyperplasia of the mesenteric veins (IMHMV) is a poorly understood disorder which poses a diagnostic challenge to clinicians and pathologists. Here we have described the case of a male patient with IMHMV along with a presumed history of ulcerative colitis for 1 year.Case presentationA 55-year-old male presented to the OPD with history of chronic abdominal pain. Clinical and radiological examination coupled with endoscopic findings resulted in the patient being wrongly diagnosed to be a case of ulcerative colitis and was managed accordingly. Throughout his multiple hospital visits following treatment for ulcerative colitis, the patient was persistently symptomatic. He presented with 10 days history of increasing abdominal pain and constipation following which he developed spontaneous colonic perforation for which he underwent exploratory laparotomy left colectomy and Hartman's procedure. The final pathology of the resected colon found to be consistent of Idiopathic myointimal hyperplasia of the mesenteric veins and ischemic bowel changes.Clinical discussionThe absence of clear-cut endoscopic biopsy findings of ulcerative colitis made radiological picture to be the mainstay for diagnosis, which was inaccurate and exposed the patient to unnecessary treatment with immuno-modulators thus resulting in poor response to treatment. As the disease progressed, further narrowing of the vessels made the clinical picture to look closer to ischemic bowel pathology as the patient developed a top surgical emergency (i.e. bowel perforation). Such pathological finding (IMHMV) can only be diagnosed in a fully prepared tissue histology, but rather be considered when no other consistent alternative diagnosis was found.ConclusionThe treating physicians must definitely consider the possibility of idiopathic myointimal hyperplasia of mesenteric veins when similar manifestations are encountered in biopsy specimens of old cases with suspected inflammatory bowel disease or non-occlusive ischemia of the distal colorectum.

S1815 A Case of Colonic Ischemia Leading to a Bowel Perforation in a Pregnant Patient

INTRODUCTION: Colonic ischemia (CI) is caused by a lack of blood flow to the colon. Its incidence is approximately 16 cases in 100,000 person-years. The majority of cases occur in patients over 60 years old. Hence, occurrence during pregnancy is considerably rare. We present a case of a 31-year-old pregnant patient with CI leading to colonic perforation. CASE DESCRIPTION/METHODS: A 31 year old G1P0 female with a past medical history of iron deficiency anemia and scoliosis presented to the emergency room at 14 weeks gestation with a three week history of abdominal pain, nausea, non-bloody watery diarrhea, poor oral intake and a nineteen pound weight loss. On presentation laboratory values showed no significant abnormalities. Physical exam revealed a distended abdomen, mild diffuse tenderness, normal bowel sounds, no rigidity or rebound tenderness. Rectal exam revealed no stool in the vault. MRI of the abdomen was significant for large descending intracolonic stool burden with relative transition zone at the sigmoid colon concerning for partial obstruction, and colonic mucosal inflammation of the descending colon. On the second day she was tachycardic, with a leukocytosis of 16.25K, and a CRP of 27.7. Her abdomen was significantly more distended, with severe diffuse tenderness and guarding. A CT scan of the abdomen and pelvis showed gross pneumoperitoneum (Figure 1). She emergently underwent exploratory laparotomy revealing multiple perforations of the descending colon. She required a total abdominal colectomy with end ileostomy. Pathology revealed scattered mucosal ulcers in the right and transverse colon, the left colon with multiple perforations, ischemic changes, and rare vascular thrombi. She has no personal or family history of thrombophilia. Thrombophilia tests including lupus anticoagulant, anti-cardiolipin, and antinuclear antibody were all normal. The patient will continue to follow with surgery, obstetrics& gynecology, and hematology. DISCUSSION: CI may be related to acute arterial occlusion, venous thrombosis, or hypoperfusion of the mesenteric vasculature causing nonocclusive ischemia. There are currently only 3 reported cases of isolated CI during pregnancy. Although CI does occur in younger patients, the diagnosis of CI may be difficult during pregnancy given the risks of obtaining CT scans with contrast. CI should be considered in the differential diagnosis of acute abdominal pain, diarrhea, and weight loss in pregnancy.Figure 1.: Computed Tomography Image illustrating pneumoperitoneum.

Pearls, Pitfalls, and Conditions that Mimic Mesenteric Ischemia at CT.

Acute mesenteric ischemia (AMI) is a life-threatening condition with a high mortality rate. The diagnosis of AMI is challenging because patient symptoms and laboratory test results are often nonspecific. A high degree of clinical and radiologic suspicion is required for accurate and timely diagnosis. CT angiography of the abdomen and pelvis is the first-line imaging test for suspected AMI and should be expedited. A systematic "inside-out" approach to interpreting CT angiographic images, beginning with the bowel lumen and proceeding outward to the bowel wall, mesentery, vasculature, and extraintestinal viscera, provides radiologists with a practical framework to improve detection and synthesis of imaging findings. The subtypes of AMI are arterial and venoocclusive disease, nonocclusive ischemia, and strangulating bowel obstruction; each may demonstrate specific imaging findings. Chronic mesenteric ischemia is more insidious at onset and almost always secondary to atherosclerosis. Potential pitfalls in the diagnosis of AMI include mistaking pneumatosis as a sign that is specific for AMI and not an imaging finding, misinterpretation of adynamic ileus as a benign finding, and pseudopneumatosis. Several enterocolitides can mimic AMI at CT angiography, such as inflammatory bowel disease, infections, angioedema, and radiation-induced enterocolitis. Awareness of pitfalls, conditions that mimic AMI, and potential distinguishing clinical and imaging features can assist radiologists in making an early and accurate diagnosis of AMI. ©RSNA, 2020.

Idiopathic Myointimal Hyperplasia of Mesenteric Veins: An Uncommon Cause of Ischemic Colitis With Distinct Mucosal Features.

Idiopathic myointimal hyperplasia of mesenteric veins causes chronic ischemic mucosal injury with segmental strictures that mimic inflammatory bowel disease and nonocclusive ischemic colitis. It is characterized by myointimal proliferative changes that narrow the lumina of veins combined with ischemic injury and ulcers. Most cases reported to date have been diagnosed following surgical resection. The aim of this study was to determine whether mucosal changes of idiopathic myointimal hyperplasia of mesenteric veins are sufficiently sensitive and specific to allow its recognition in biopsy material. The study group consisted of 10 patients with idiopathic myointimal hyperplasia of mesenteric veins who underwent surgical resection of the affected colon, 7 of whom had available prior endoscopic biopsies. The control group included 10 patients each with radiation, nonocclusive ischemia, Crohn disease, diverticulitis, and mucosal amyloidosis, and 5 cases of small vessel (leukocytoclastic) vasculitis. Study patients were mostly older men with distal colorectal disease. All resection specimens showed mucosal ischemia with numerous thick-walled (arteriolized) capillaries and glassy subendothelial fibrin deposits; numerous hyalinized, eosinophilic thrombi were detected in 90% of colectomy specimens. Biopsies showed arteriolized capillaries (100%), subendothelial fibrin deposits (86%), fibrin thrombi (43%), and perivascular hyalinization (43%). Fibrin thrombi were observed in only one case each of ischemic colitis and small vessel vasculitis, and none of the other abovementioned features were seen in any of the controls. We conclude that arteriolized capillaries, subendothelial fibrin deposits, and perivascular hyalinization are frequent and specific features that can facilitate recognition of idiopathic myointimal hyperplasia of mesenteric veins in biopsy samples.

Colonic Ischemia in a High-Performance Aircraft Pilot

Introduction: Those undergoing accelerated g-forces experience tissue ischemia due to pooling of blood within the extremities. While the most common side effect of accelerated g-forces is loss of consciousness, any part of the body at risk of decreased perfusion may be affected. Case Description: A 23 year old Japanese male with no significant past medical history was sent to the United States for flight training at a local Air Force base. During a mission he reportedly experienced a gravitational force of 4.5 which was the highest yet in his training. Following the flight he immediately developed abdominal cramping with hematochezia that gradually improved over the following three days. Colonoscopy was performed and was significant for patchy, erythematous and edematous mucosa within the recto-sigmoid junction concerning for colonic ischemia and was otherwise normal. Biopsies of the affected areas were obtained and revealed non-specific lamina propria congestion which may be seen in healing colonic ischemia. The patient denied a personal or family history of thromboembolic disorders, tobacco use, recent travel, prescription or over the counter medication use. The patient was treated conservatively and was able to return to regular flight duty without any further incidents. Discussion: Colonic ischemia (CI) is not uncommon but is rarely reported in those who are healthy and younger than 50. The cause of CI is thought to be related to hypoperfusion followed by a reperfusion injury. Often times a specific cause for ischemia is not identified and the incident is attributed to non-occlusive ischemia. Risk factors for CI include hypoperfusion states such as heart failure, sepsis and physical activity, mechanical colonic obstruction, medications, and perioperative. A review of the literature reveals two case reports of adults who developed CI after transatlantic flights with no other risk factors identified. To our knowledge this is the first case report of CI following exposure to increased g-force.

The length of necrosis and renal insufficiency predict the outcome of acute mesenteric ischemia

Acute mesenteric ischemia (AMI) is a potentially life-threatening condition because of its diagnostic difficulty, operative challenges, and comorbidities a patient may have. The aim of this study was to identify factors associated with adverse outcomes in patients with AMI. The hospital records and clinical data of all patients with AMI were reviewed for a recent 4-year period. Clinical outcomes and factors influencing mortality were analyzed. Included in the study were 104 patients (46 females and 58 males) with an overall mean age of 66 ± 13.4 years. The cause of AMI was arterial pathology in 74 (71%) patients, venous thrombosis in 15 (14%) patients, and nonocclusive ischemia in 12 (12%) patients. Abdominal pain was the most common presenting symptom (97% of patients). The 30-day mortality rate was 66%. Univariate analysis showed that mortality was associated with renal insufficiency (p = 0.004), an age greater than 70 years (p = 0.02), the presence of comorbidities (p = 0.001), a leukocyte count greater than 18,000/mL (p = 0.04), and small bowel necrosis of more than 100 cm (p < 0.0001). Logistic regression analysis showed that independent predictors of mortality were small bowel necrosis of more than 100 cm (p = 0.002) and a serum creatinine level greater than 2 mg/dL (p = 0.04). The length of the necrosis and renal insufficiency are the primary factors that result in a poor outcome in AMI patients. Prompt diagnostic evaluation and early therapeutic interventions may help to prevent the development of these fatal predictors.

Gradual Colonic Impaction of a Chicken Bone Associated with Inflammatory Pseudotumor Formation and Nonocclusive Colon Ischemia

Foreign body (FB) ingestion is a common clinical problem and most FBs pass through the gastrointestinal tract without the need for intervention. A wide spectrum of clinical presentations may be possible and these can be either acute or chronic. We present a case of an 83-year-old woman featuring insidious abdominal discomfort who was hospitalized in our institution due to worsening symptoms. She underwent contrast-enhanced computed tomography (CT) evaluation which showed the presence of a significant parietal thickening of the transverse and descending colon, a mesenteric loose tissue imbibition, venous engorgement, and no filling defect of visceral arteries, suggesting a condition of nonocclusive colon ischemia. A hyperdense FB was identified in the sigma and was associated with a small pseudotumoral mass. The patient underwent surgical exploration which confirmed the hypoperfusional state of the colon, showing the presence of a chicken bone perforating the sigma and lying in the context of a pseudotumoral mass. Our experience shows how contrast-enhanced CT is feasible and can be strongly recommended as a first-line imaging tool on suspicion of colon ischemia and also how it can easily identify the underlying cause, in our case a FB sealed perforation of the sigma with pseudotumoral mass formation.

Incidence, survival and determinants of mortality following mesenteric angiography and continuous intra-arterial prostaglandin E1 perfusion for non-occlusive mesenterial ischaemia in cardiac surgery

Methods Our aim was to evaluate the incidence of NOMI, to analyze results of treatment and to identify variables associated with mortality. Hospital records and clinical data of patients treated for NOMI during the last 12 years were reviewed. Clinical outcomes and factors influencing mortality were studied. Statistical analysis was performed to determine the significance of risk factors on mortality with Fisher exact test or c2 test in categorical variables. Wilcoxon rank test was used to test the continuous variables.

Launching a Permanent Out-of-Hour Interventional Radiology Service: Single-Center Experience from a German University Hospital

To evaluate the feasibility, frequency of use, types of intervention and labor costs of a formal round-the-clock interventional radiology on-call service. In 11/2011 a formal and permanent out-of-hour interventional radiology rota in addition to the general radiology out-of-hour rota (OOHR) was established. We retrospectively screened the interventional radiology database for procedures completed outside regular working hours, reviewed all interventions and manually selected cases in which the on-call interventionist was called in from home. We determined the type, frequency of use and costs (€/year and procedure) of this service between 1/2012 and 12/2012. The referring physicians' (sub-) specialties were evaluated. During the 12-month period, the on-call interventionists (n = 3) performed 92 procedures OOH. The procedures included angiography and hemorrhage control (n = 36, 39.1 %), angiography and intervention for acute limb ischemia (n = 25, 27.2 %), percutaneous biliary drainage (PTCD) (n = 10, 10.9 %), angiography for non-occlusive ischemia (n = 7, 7.6 %), and other (n = 14, 15.3 %). The total labor costs for the OOHR were € 42,312.21 (€ 32,982.60 lump sum for stand-by, € 9,329.61 for hours spent on procedures). The labor costs per procedure totaled € 459.92. The referring physicians' specialties were general/visceral (n = 25), vascular surgery (n = 24), internal medicine (n = 21), cardiac/thoracic vascular (n = 9), trauma surgery (n = 5), urology (n = 5), and anesthesiology (n = 3). A formal interventional OOHR is practicable in a university hospital setting. Most procedures were requested by general, vascular, and thoracic surgery as well as internal medicine with a focus on hemorrhage control, treatment of acute limb ischemia, and PTCD. The overall labor costs for the OOHR appear moderate. • In a university setting an OOHR for IR is feasible.• Labor costs per procedure appear moderate.• Hemorrhage control and treatment of limb ischemia were the most frequent procedures. Citation Format: • Goltz JP, Janssen H, Petritsch B et al. Launching a Permanent Out-of-Hour Interventional Radiology Service: Single-Center Experience from a German University Hospital. Fortschr Röntgenstr 2014; 186: 136 - 141.

ACR Appropriateness Criteria ® imaging of mesenteric ischemia.

Mesenteric ischemia is a rare disease associated with high morbidity and mortality. Acute mesenteric ischemia is most commonly secondary to embolism followed by arterial thrombosis, nonocclusive ischemia, and less commonly venous thrombosis. Chronic mesenteric ischemia is almost always caused by atherosclerotic disease, with rare causes including fibromuscular dysplasia and vasculitis. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment. Patients with mesenteric ischemia usually present with nonspecific abdominal symptoms and laboratory findings. This document evaluates and rates the appropriateness of imaging to evaluate patients with clinically suspected mesenteric ischemia. While catheter-based angiography has been considered the reference standard and enables diagnosis and treatment, advances in computed tomography have made it a first-line test in many patients because it is a fast, widely available, and noninvasive study. Abdominal radiographs and ultrasound have a limited role in diagnosing mesenteric ischemia but are commonly the first ordered tests in patients with abdominal pain and may diagnose more common pathologies.

Extensive colonic necrosis following cardiac arrest and successful cardiopulmonary resuscitation: report of a case and literature review

Non-occlusive colonic ischaemia is a recognized albeit rare entity related to low blood flow within the visceral circulation and in most reported cases the right colon was affected. This is the second case report in the literature of extensive colonic necrosis following cardiac arrest and cardiopulmonary resuscitation (CPR). A 83-year-old Caucasian woman was admitted to our hospital due to a low energy hip fracture. On her way to the radiology department she sustained a cardiac arrest. CPR started immediately and was successful. A few hours later, the patient developed increasing abdominal distension and severe metabolic acidocis. An abdominal multidetector computed tomography (MDCT) scan was suggestive of intestinal ischaemia. At laparotomy, the terminal ileum was ischaemic and extensive colonic necrosis was found, sparing only the proximal third of the transverse colon. The rectum was also spared. The terminal ileum and the entire colon were resected and an end ileostomy was fashioned. Although the patient exhibited a transient improvement during the immediate postoperative period, she eventually died 24h later from multiple organ failure. Histology showed transmural colonic necrosis with no evidence of a thromboembolic process or vasculitis. Therefore, this entity was attributed to a low flow state within the intestinal circulation secondary to the cardiac arrest.

Non-occlusive colonic ischemia induced by verapamil ER overdose

Sir: Verapamil overdose can cause conduction disturbances and hypotension with cardiogenic shock [1], both of which can lead to ischemia. The colon is susceptible to ischemia because of the variable amount of collateral blood flow present, especially in arteriosclerotic patients [2, 3]. We report a case of colonic ischemia after verapamil overdose. A 60-year-old man with a history of hypertension, arteriosclerosis, aortofemoral bypass (with clamping of inferior mesenteric artery) 2 years ago and tobacco addiction was being treated with clopidogrel 75 mg/day and verapamil ER 240 mg/day. He came to the emergency department intoxicated after taking approximately 30 verapamil extended-release tablets and three clopidogrel tablets as a suicide attempt. His blood pressure was 72/38 mmHg, and his pulse rate was 52 beats/min. He was drowsy and had thready peripheral pulses. An electrocardiogram showed an atrioventricular block. A bottle of activated charcoal (50 g) was given and could be ingested by the patient. Despite the administration of intravenous fluids, calcium gluconate, and vasopressors, the patient’s blood pressure only marginally improved. He subsequently developed lower abdominal pain. Repeated examination showed abdominal distension with lower-quadrant guarding and absent bowel sounds. His leukocyte count was 22,000 cells/mm, and tomodensitometry of the abdomen showed a peritoneal effusion, a defect of opacification of the left colon with respect to opacification of celiac and superior mesenteric arteries (Fig. 1a, b). An exploratory laparotomy showed a gangrenous segment of the left colon; the rest of the colon and ileum was normal. He had a left hemicolectomy with a colostomy. Histolopathological evaluation showed a pronounced edema of the submucosa with the dilation of the submucosal vessels and several areas with necrotic ulcerations and intramural bleeding (Fig. 1c, d). There was no evidence of thromboembolic obstruction. He was hemodynamically stable during the remainder of his hospitalization and developed immediately acute respiratory distress syndrome. Finally, he left the ICU at day 30. Long-term verapamil use has also been reported as a cause of stercoral perforation of the sigmoid colon [4]. A previous case of caecal and

Chronic diarrhoea-author's response

I thank Mr Marston for his comments regarding our article (JRSM 2007;100: 379).1 He raises two issues. Regarding the first, I agree that the patient may have been saved from all the invasive investigations if the thyromegaly and cervical lymph node enlargement had been identified earlier. I can only surmise that the clinical findings in the neck were not present or were subtle at the time of initial assessment. This case highlights the point that general physical examination of a patient provides vital clues to the diagnosis—a fact that is sometimes overlooked. It is our responsibility to emphasize the importance of this to the next generation of clinicians. As for the second point, the causes of chronic diarrhoea were taken from a reputable peer-reviewed journal (Gut).2 Ischaemia of the gut has been given different nomenclatures, including mesenteric ischaemia, gut ischaemia, bowel ischaemia and intestinal ischaemia. There is evidence that colonic ischaemia can present as chronic colitis, with endoscopy changes mimicking those seen in inflammatory bowel disease. In most cases, no cause is found and the episodes are considered to be due to localized non-occlusive ischaemia, perhaps due to small vessel disease.3 Mesenteric atherosclerosis can cause chronic mesenteric ischaemia (intestinal angina) where patients present with post-prandial abdominal pain, nausea, bloating and episodic diarrhoea. Malabsorption or constipation can occur. Objective evidence of ischaemia to small bowel causing these symptoms is difficult to obtain. However, focal segmental necrosis of the small bowel can cause symptoms indistinct from Crohn's disease.3 There is a case report of small bowel ischaemic necrosis diagnosed by video capsule endoscopy.4 This investigation and double balloon enteroscopy may shed more light on the pathophysiological changes that occur in the small bowel secondary to mesenteric ischaemia.

A case of ischemic colitis associated with factor V Leiden mutation: successful treatment with anticoagulation

Numerous factors have been implicated in the etiology of ischemic colitis (IC), but most cases are secondary to nonocclusive ischemia or hypoperfusion of the colon.1 Associations with inherited thrombophilia (deficiency of protein C, protein S, and antithrombin III) and inherited and acquired resistance to activated protein C and oral contraceptives (OCP) have been reported but are relatively uncommon.2-4 In young adults, IC is often associated with hypercoagulable states that result in thrombotic occlusion of small vessels.

Non-occlusive acute intestinal vascular failure

Summary The records of 87 patients with vascular intestinal insufficiency leading to gangrene were analysed in retrospect. In 77 patients the cause of the vascular insufficiency could be determined. In 25 per cent no organic obstruction to blood flow was found in the macroscopic intestinal vessels. The patients with non-occlusive intestinal gangrene showed a tendency to be younger and to have associated cardiac infarction more frequently than those with vessel obstructions. Moreover, non-occlusive intestinal gangrene was found more frequently following a period of systemic arterial hypotension. A history of atrial fibrillation and digitalis therapy was present with equal frequency in both groups of patients. Based on these cases and on current animal experimental data, it is suggested that the bowel gangrene seen in non-occlusive ischaemia is due to short-circuiting of oxygen at the base of the villi in the villous counter-current exchanger. This mechanism becomes much more effective in hypotension owing to reduced velocity of the villous blood flow. The possibility is emphasized that, with a coexisting atherosclerotic narrowing in the mesenteric vascular tree, cardiovascular disturbances which are themselves not enough to alter central arterial pressure, may none the less induce regional hypotension. Such regional hypotension could lead to villous destruction and initiate a vicious circle which ends in generalized gangrene of the bowel.

Clinical Impact of Gastric Exercise Tonometry on Diagnosis and Management of Chronic Gastrointestinal Ischemia

Chronic gastrointestinal ischemia or chronic splanchnic syndrome is a difficult diagnosis. The use of a physiologic test, combined with clinical and anatomic data, should improve diagnostic accuracy. This study evaluates the diagnostic accuracy and clinical impact of gastric tonometry during exercise (GET) in a patient cohort suspected of chronic splanchnic syndrome. From 1997 to 2000, 102 patients with chronic abdominal pain were analyzed. The workup included GET and selective biplane angiography. The diagnosis of gastrointestinal ischemia was based on consensus in a multidisciplinary working group and sustained on follow-up. Gastrointestinal ischemia was diagnosed in 38 patients. In 33 patients chronic splanchnic syndrome was found, with single vessel involvement in 20 (17 celiac artery, 3 mesenteric superior) and multivessel disease in 13. In 5 patients nonocclusive ischemia was found. By using receiver operator curve analysis, the difference between gastric and arterial partial pressure of carbon dioxide (PCO2 gradient) proved to be the best GET parameter. The criteria for diagnosing ischemia in GET were Pco2 gradient > 0.8 kPa and increase gastric PCO2, with base excess decrease <8 mmol/L during exercise. GET had 78% sensitivity and 92% specificity. Twenty-five patients underwent vascular treatment (19 operative, 6 stent/percutaneous transluminal angioplasty). After 4 years of follow-up 83% of patients were alive and free of symptoms. GET is an accurate diagnostic tool to show gastrointestinal ischemia. Including GET into clinical decision making enabled selecting patients with ischemia, who benefited from vascular and medical treatment. These benefits were sustained during 4-year follow-up. GET should be considered in the workup of patients with a suspected diagnosis, of gastrointestinal ischemia.

Systematic review of survival after acute mesenteric ischaemia according to disease aetiology.

Differentiation of acute mesenteric ischaemia on the basis of aetiology is of great importance because of variation in disease progression, response to treatment and outcome. The aim of this study was to analyse the published data on survival following acute mesenteric ischaemia over the past four decades in relation to disease aetiology and mode of treatment. A systematic review of the available literature from 1966 to 2002 was performed. Quantitative analysis of data derived from 45 observational studies containing 3692 patients with acute mesenteric ischaemia showed that the prognosis after acute mesenteric venous thrombosis is better than that following acute arterial mesenteric ischaemia; the prognosis after mesenteric arterial embolism is better than that after arterial thrombosis or non-occlusive ischaemia; the mortality rate following surgical treatment of arterial embolism and venous thrombosis (54.1 and 32.1 per cent respectively) is less than that after surgery for arterial thrombosis and non-occlusive ischaemia (77.4 and 72.7 per cent respectively); and the overall survival after acute mesenteric ischaemia has improved over the past four decades. There are large differences in prognosis after acute mesenteric ischaemia depending on aetiology. Surgical treatment of arterial embolism has improved outcome whereas the mortality rate following surgery for arterial thrombosis and non-occlusive ischaemia remains poor.