Acute mesenteric ischemia

[Epidemiology and diagnostics of mesenteric ischemia]

BACKGROUND

Mesenteric ischemia is a life-threatening condition with a complex etiology and diagnostics.

OBJECTIVE

Etiology, incidence, symptoms, and diagnostics of acute and chronic mesenteric ischemia.

MATERIAL AND METHODS

Literature search via PubMed with a focus on studies on the epidemiology and diagnostics of mesenteric ischemia and analysis of existing international guidelines.

RESULTS

The incidence of acute mesenteric ischemia is given as 0.63-12.9 per 100,000 people per year. There are no sufficiently reliable figures for chronic mesenteric ischemia, but an incidence of up to 3 per 100,000 inhabitants per year is generally assumed. The three-phase computed tomography has the highest diagnostic specificity and sensitivity.

CONCLUSION

In the presence of risk factors acute and chronic mesenteric ischemia should be considered as differential diagnoses in the presence of abdominal pain using three-phase computed tomography.

Evaluation of Abdominal Emergencies

Early primary assessment and abdominal examination can often be enough to triage the patient with abdominal pain into those with less severe underlying pathologic condition from those with more acute findings. A focused history of the patient can then allow the clinician to develop their differential diagnosis. Once the differential diagnoses are determined, diagnostic imaging and laboratory findings can help confirm the diagnosis and allow for expeditious treatment and intervention.

Prognostic factors after acute mesenteric ischemia: which patients require specific management?

PURPOSE

Diagnosis and treatment of AMI are a real issue for implicating physicians. In the literature, only one AMI stroke center has reported its results so far, with increasing survival rates. Our aim was to analyze acute mesenteric ischemia (AMI) related mortality and predictive factors, in a single academic center, before creating a dedicated intestinal stroke center.

METHODS

All the patients with an AMI, between January 2015 and December 2020, were retrospectively included. They were divided into 2 groups according to the early mortality: death during the first 30 days and alive. The 2 groups were compared.

RESULTS

173 patients (57% of men), were included, with a mean age of 68 ± 16 years. Overall mortality rate was 61%. Mortality occurred within the first 30 days in 78% of dead cases. Dead patients were significantly older, more frequently admitted from intensive care, with more serious clinical, laboratory and radiological characteristics. We have identified 3 protective factors - history of abdominal surgery (Odd Ratio = 0.1; 95%CI = 0.01-0.8, p = 0.03), medical management with curative anticoagulation (OR = 0.09; 95%CI = 0.02-0.5, p = 0.004) and/or antiplatelets (OR = 0.04; 95%CI = 0.006-0.3, p = 0.001)-, and 2 predictive factors of mortality - age > 70 years (OR = 7; 95%CI = 1.4-37, p = 0.02) and previous history of coronaropathy (OR = 13; 95%CI = 1.7-93, p = 0.01).

CONCLUSIONS

AMI is a severe disease with high morbidity and mortality rates. Even if its diagnosis is still difficult because of non-specific presentation, its therapeutic management needs to be changed in order to improve survival rates, particularly in patients older than 70 years with history of coronaropathy. Developing a dedicated organization would improve the diagnosis and the management of patients with AMI.

Results after intraoperative open and endovascular revascularization of acute mesenteric ischemia requiring a laparotomy

BACKGROUND

Acute mesenteric ischemia (AMI) is a dreaded condition with a difficult diagnosis and high mortality. Due to different baseline situations, the frequently performed comparison between endovascular and open surgical treatment is interfered with selection bias. The purpose of this study was to review outcomes in AMI treatment with an open or endovascular approach in association with laparotomy and to evaluate the endovascular-first strategy in similar clinical situations.

METHODS

The clinical data of 74 patients treated for AMI from 2007 to 2021 were retrospectively reviewed and compared. In-hospital mortality was appointed as the primary study endpoint. Risk factors for mortality were identified by using univariate and multivariate analysis.

RESULTS

In total, 61 patients (82%) were treated open surgically (OT) and, 13 patients (18%) with an endovascular approach (ET) in combination with laparatomy. The etiology of AMI was 49% arteriosclerotic and 51% thromboembolic occlusions. The total in-hospital mortality manifested at 43% (n =32) (OT 41% vs. ET 53.8%; P=0.54). As independent risk factors for in-hospital mortality, pneumatosis intestinalis (P=0.01), increased lactate concentration (P=0.04), and ischemic intestinal sections (P=0.01) were identified. Additionally, on univariate analysis patient age, congestive heart failure (> NYHA II) and atrial fibrillation were related with higher mortality.

CONCLUSIONS

Morbidity and mortality of AMI remains at a high level. Conventional open or intraoperative endovascular therapy achieved similar results in patients with indication for laparotomy. Advanced disease stage with ischemic intestinal sections at presentation and cardiovascular comorbidities were associated with adverse outcome.

Mortality Prediction Model before Surgery for Acute Mesenteric Infarction: A Population-Based Study

Surgery for acute mesenteric infarction (AMI) is associated with high mortality. This study aimed to generate a mortality prediction model to predict the 30-day mortality of surgery for AMI. We included patients ≥18 years who received bowel resection in treating AMI and randomly divided into the derivation and validation groups. After multivariable analysis, the ‘Surgery for acute mesenteric infarction mortality score’ (SAMIMS) system was generated and was including age >62-year-old (3 points), hemodialysis (2 points), congestive heart failure (1 point), peptic ulcer disease (1 point), diabetes (1 point), cerebrovascular disease (1 point), and severe liver disease (4 points). The 30-day-mortality rates in the derivation group were 4.4%, 13.4%, 24.5%, and 32.5% among very low (0 point), low (1−3 point(s)), intermediate (4−6 points), and high (7−13 points)-risk patients. Compared to the very-low-risk group, the low-risk (OR = 3.332), intermediate-risk (OR = 7.004), and high-risk groups (OR = 10.410, p < 0.001) exhibited higher odds of 30-day mortality. We identified similar results in the validation group. The areas under the ROC curve were 0.677 and 0.696 in the derivation and validation groups. Our prediction model, SAMIMS, allowed for the stratification of the patients’ 30-day-mortality risk of surgery for acute mesenteric infarction.

Acute Mesenteric Ischemia

The surgical treatment of occlusive acute mesenteric ischemia (AMI) without revascularization is associated with an 80% overall mortality. Early diagnosis is crucial, and revascularization may reduce overall mortality in AMI by up to 50%. A diagnosis of AMI requires a high index of clinical suspicion and the collaborative effort of emergency department physicians, general and vascular surgeons, and radiologists. This article provides an overview of the etiology, physiology, evaluation, and management of acute mesenteric ischemia.

Non-occlusive mesenteric ischemia (NOMI) and prognostic signs at CT: reperfusion or not reperfusion that is the question!

PURPOSE

Non-occlusive mesenteric ischemia (NOMI) is a misdiagnosed and dangerous condition. To our knowledge, a comprehensive evaluation of CT parameters that can predict the outcome of patients suffering from NOMI is still missing.

MATERIALS AND METHODS

Contrast-enhanced CT examination of 84 patients with a confirmed diagnosis of NOMI (37 with clinical and laboratory confirmation and 47 biopsy or surgery proven) was retrospectively reviewed by assessing vessels, mesentery, bowel, and peritoneal cavity CT quantitative and dichotomous parameters, and data were analyzed with Fisher's test. Diameter of superior mesenteric artery (SMA), celiac trunk (CT), inferior vena cava (IVC), superior mesenteric vein (SMV), and differences in CT HU (Delta HU) of the bowel wall before and after intravenous contrast media (ICM) administration were correlated to the patients' outcome using ANOVA test. Receiver operating characteristic (ROC) curves were elaborated after a binary logistic regression was performed.

RESULTS

Increased number and diameter of vessels, bowel wall thickening, and hypervascularity were more frequent in patients with good prognosis. Conversely, pale mesentery, paper thin, hypovascularity, and aeroportia were more frequent in patients with bad prognosis. A significant correlation between diameters of SMA, CT, IVC, IMA, and SMV and outcome was found at univariate analysis. Also Delta HU resulted to be correlated with the outcome. At multivariate analysis only IVC and Delta HU were significant (p = 0.038 and 0.01) and the combined AUC resulted in 0.806 (CI 0.708-0.903).

CONCLUSION

Dichotomous signs of reperfusion and quantitative CT parameters can predict the outcome of patients with NOMI. In particular the combination of IVC diameter and Delta HU of bowel wall allows to predict the prognosis with the highest accuracy.

Mesenteric Vessel Thrombosis Treatment Experience

BACKGROUND: One of the most serious diseases among all emergency abdominal pathology is an acute violation of the mesenteric blood circulation. The rapid development of intestinal ischemia results in its infarction and necrosis. AIM: The study aims to assess the survival rate of patients with mesenteric vascular thrombosis, taking into account, the predictor characteristics influence of disease development factors. METHODS: The study presents a retrospective analysis of mesenteric vascular thrombosis clinical cases for 2016–2019. During this period, there were 147 patients with an established diagnosis at the Irkutsk Clinical Hospital No. 1, 21 of them met the study criteria. RESULTS: According to the type of thrombosis, there were two groups – occlusive (Group I, n = 11) and non occlusive (Group II, n = 10). Four patients (36.3%) of Group I and 7 patients (70%) of Group II (p = 0.388) recovered from the disease. Three patients (27.2%) of Group I and 4 patients (40%) of Group II (p = 0.662) received conservative therapy, 2 of them (66.6%) in Group I and 4 (100%) in Group II (p = 0.724) recovered from the disease. In addition, the authors performed a mortality assessment, according to the timing of the visit to a medical institution. Four (50%) out of eight patients who applied in the first 12 h, 2 (66%) out of three – in the first 12–24 h, and 5 (50%) out of 10 for more than 24 h of illness had a positive treatment result in the combined group. CONCLUSION: The patients over 70 years old with peritoneal symptoms and established intestinal necrosis have an extremely unfavorable prognosis. The primary mesenteric vessel thrombosis with additional contrast angiography still gives a moderate treatment prognosis.

A Rare Case of Acute Mesenteric Ischemia in the Setting of COVID-19 Infection

Severe respiratory syndrome coronavirus 2 (SARS-CoV-2) is well known for causing respiratory and other extrapulmonary manifestations. Patients infected with coronavirus disease 2019 (COVID-19) may demonstrate atypical presentations with gastrointestinal symptoms. Clinicians managing these patients should reserve a high index of suspicion for the rare complication of acute mesenteric ischemia (AMI). It is a challenging diagnosis that is often missed when presenting symptoms are subtle and nonspecific like nausea, emesis, or diarrhea. Outcomes are typically catastrophic and fatal as bowel ischemia progresses to necrosis but may be averted with timely diagnostic and therapeutic methods to swiftly restore blood flow.

Nationwide Study to Predict Colonic Ischemia after Abdominal Aortic Aneurysm Repair in The Netherlands

BACKGROUND

Colonic ischemia remains a severe complication after abdominal aortic aneurysm (AAA) repair and is associated with a high mortality. With open repair being one of the main risk factors of colonic ischemia, deciding between endovascular or open aneurysm repair should be based on tailor-made medicine. This study aims to identify high-risk patients of colonic ischemia, a risk that can be taken into account while deciding on AAA treatment strategy.

METHODS

A nationwide population-based cohort study of 9,433 patients who underwent an AAA operation between 2014 and 2016 was conducted. Potential risk factors were determined by reviewing prior studies and univariate analysis. With logistic regression analysis, independent predictors of intestinal ischemia were established. These variables were used to form a prediction model.

RESULTS

Intestinal ischemia occurred in 267 patients (2.8%). Occurrence of intestinal ischemia was seen significantly more in open repair versus endovascular aneurysm repair (7.6% vs. 0.9%; P < 0.001). This difference remained significant after stratification by urgency of the procedure, in both intact open (4.2% vs. 0.4%; P < 0.001) and ruptured open repair (15.0% vs. 6.2%); P < 0.001). Rupture of the AAA was the most important predictor of developing intestinal ischemia (odds ratio [OR], 5.9, 95% confidence interval [CI] 4.4-8.0), followed by having a suprarenal AAA (OR 3.4; CI 1.1-10.6). Associated procedural factors were open repair (OR 2.8; 95% CI 1.9-4.2), blood loss >1L (OR 3.6; 95% CI 1.7-7.5), and prolonged operating time (OR 2.0; 95% CI 1.4-2.8). Patient characteristics included having peripheral arterial disease (OR 2.4; 95% CI 1.3-4.4), female gender (OR 1.7; 95% CI 1.2-2.4), renal insufficiency (OR 1.7; 1.3-2.2), and pulmonary history (OR 1.6; 95% CI 1.2-2.2). Age <68 years proved to be a protective factor (OR 0.5; 95% CI 0.4-0.8). Associated mortality was higher in patients with intestinal ischemia versus patients without (50.6% vs. 5.1%, P < 0.001). Each predictor was given a score between 1 and 4. Patients with a score of ≥10 proved to be at high risk. A prediction model with an excellent AUC = 0.873 (95% CI 0.855-0.892) could be formed.

CONCLUSIONS

One of the main risk factors is open repair. Several other risk factors can contribute to developing colonic ischemia after AAA repair. The proposed prediction model can be used to identify patients at high risk for developing colonic ischemia. With the current trend in AAA repair leaning toward open repair for better long-term results, our prediction model allows a better informed decision can be made in AAA treatment strategy.

Gastrointestinal complications following cardiac surgery

Gastrointestinal complications after cardiac surgery may be uncommon but they carry high mortality rates. Incidences range from 0.5% to 5.5%, while mortality rates of such complications vary from 0.3% to 87%. They range from small gastrointestinal bleeds, ileus, and pancreatitis to life-threatening complications such as liver failure and ischemic bowel. Due to the vague and often absence of specific signs and symptoms, diagnosis of a gastrointestinal complication is often late. This article aims to review and summarize the literature concerning gastrointestinal complications after cardiac surgery. We discuss the causes, risk factors, diagnosis, preventative measures, and management of these complications. In general, risk factor identification, preventive measures, early diagnosis, and swift management are the keys to reducing the occurrence of gastrointestinal complications and their associated morbidity and mortality.

Review Article: Mesenteric Ischemia

PURPOSE OF REVIEW

Mesenteric ischemia (MI), both acute (AMI) and chronic (CMI), is a challenging diagnosis to make, and early diagnosis and treatment are vital to improve outcomes. This manuscript summarizes the most up to date information on diagnosis and treatment of these disorders.

RECENT FINDINGS

There have been several significant advancements in the computed tomography (CT) diagnostic imaging as well as medical and endovascular management of AMI and CMI. In appropriate populations, endovascular interventions appear superior to open surgical management with lower mortality, morbidity, and cost of care. Efficient clinical identification and targeted testing are essential to diagnose AMI and CMI. Aggressive resuscitation and early endovascular (or in select cases, surgical) intervention improve outcomes in those with AMI. In those with CMI, considering this on the differential diagnosis and imaging appropriately can identify those that might benefit from intervention and halt progression to acute episodes.

Acute mesenteric ischaemia: imaging and intervention

Acute mesenteric ischaemia (AMI) is an abdominal emergency in which an acute reduction in mesenteric arterial supply threatens bowel viability and may result in bowel infarction, perforation, and death. Despite improvements in diagnosis and treatment over recent decades, mortality rates in AMI remain very high. This article discusses the aetiological classification, pathophysiology, and clinical aspects of AMI. The specific imaging characteristics of each aetiological type of AMI are detailed and the role of different imaging methods in the diagnosis of AMI is discussed. Surgery is the established treatment of choice for AMI, but there is increasing use of endovascular techniques in treating AMI in cases where there are no clinical features of peritonism or radiological evidence of irreversible ischaemia. This article reviews the evidence for different diagnostic and management strategies for patients with AMI and discusses the advantages and disadvantages of surgical and endovascular treatments. Endovascular techniques have been reported to have high technical success rates and favourable outcomes when compared to open surgery; however, patient selection bias and a paucity of data limit the conclusions that can be drawn.

Gastrointestinal and liver diseases and atrial fibrillation: a review of the literature

Atrial fibrillation (AF) is the most common arrhythmia worldwide and is associated with significant morbidity and mortality. A number of risk factors have been associated with AF, though few studies have explored the association between gastrointestinal and liver diseases and AF. Additionally, AF and treatment for AF may predispose to gastrointestinal and liver diseases. We review the current literature on the bidirectional associations between gastrointestinal and liver diseases and AF. We highlight the gaps in knowledge and areas requiring future investigation.

Age- and gender-related hemorheological alterations in intestinal ischemia-reperfusion in the rat

BACKGROUND

Intestinal ischemia-reperfusion (I/R) is a life-threatening clinical disorder. During I/R, the microrheological parameters of blood (red blood cell deformability and aggregation) worsen, which may contribute to microcirculatory deterioration. Age and gender also have a great influence on hemorheological parameters. We aimed to investigate the gender and age-related microrheological alterations during intestinal I/R.

MATERIALS AND METHODS

After the cannulation of the left femoral artery, median laparotomy was performed in Crl:WI rats under general anesthesia. In the young control animals there were no other interventions (female n = 7; male n = 7). In the young (female n = 7; male n = 7) and older I/R groups (female n = 6; male n = 6), the superior mesenteric artery was clipped for 30 min, and a 120-min reperfusion period was observed afterward. Blood samples were taken before and at the 30-min ischemia, in the 30th, 60th, and 120th min of the reperfusion. Hematological parameters, erythrocyte deformability, and aggregation were determined.

RESULTS

Hematocrit increased significantly in the younger female I/R group. Red blood cell count was higher in male and older animals. In case of white blood cell count, male animals had higher values compared with females. Platelet count elevated in the younger male and older female I/R animals. Red blood cell deformability worsened, mainly in the male and older I/R groups. Enhanced erythrocyte aggregation was seen in all groups, being more expressed in the female I/R groups.

CONCLUSIONS

Microrheological parameters show gender and age-related differences during intestinal I/R. These observations have importance in the planning and evaluation of experimental data.

The mesentery: structure, function, and role in disease

Systematic study of the mesentery is now possible because of clarification of its structure. Although this area of science is in an early phase, important advances have already been made and opportunities uncovered. For example, distinctive anatomical and functional features have been revealed that justify designation of the mesentery as an organ. Accordingly, the mesentery should be subjected to the same investigatory focus that is applied to other organs and systems. In this Review, we summarise the findings of scientific investigations of the mesentery so far and explore its role in human disease. We aim to provide a platform from which to direct future scientific investigation of the human mesentery in health and disease.

ESTES guidelines: acute mesenteric ischaemia

PURPOSE

Acute mesenteric ischaemia (AMI) accounts for about 1:1000 acute hospital admissions. Untreated, AMI will cause mesenteric infarction, intestinal necrosis, an overwhelming inflammatory response and death. Early intervention can halt and reverse this process leading to a full recovery, but the diagnosis of AMI is difficult and failure to recognize AMI before intestinal necrosis has developed is responsible for the high mortality of the disease. Early diagnosis and prompt treatment are the goals of modern therapy, but there are no randomized controlled trials to guide treatment and the published literature contains a high ratio of reviews to original data. Much of that data comes from case reports and often small, retrospective series with no clearly defined treatment criteria.

METHODS

A study group of the European Society for Trauma and Emergency Surgery (ESTES) was formed in 2013 with the aim of developing guidelines for the management of AMI. A comprehensive literature search was performed using the Medical Subject Heading (MeSH) thesaurus keywords "mesenteric ischaemia", "bowel ischaemia" and "bowel infarction". The bibliographies of relevant articles were screened for additional publications. After an initial systematic review of the literature by the whole group, a steering group formulated questions using a modified Delphi process. The evidence was then reviewed to answer these questions, and recommendations formulated and agreed by the whole group.

RESULTS

The resultant recommendations are presented in this paper.

CONCLUSIONS

The aim of these guidelines is to provide recommendations for practice that will lead to improved outcomes for patients.

Curcumin protects against the intestinal ischemia-reperfusion injury: involvement of the tight junction protein ZO-1 and TNF-α related mechanism

Present study aimed to investigate the eff ect of curcumin-pretreatment on intestinal I/R injury and on intestinal mucosa barrier. Thirty Wistar rats were randomly divided into: sham, I/R, and curcumin groups (n=10). Animals in curcumin group were pretreated with curcumin by gastric gavage (200 mg/kg) for 2 days before I/R. Small intestine tissues were prepared for Haematoxylin & Eosin (H&E) staining. Serum diamine oxidase (DAO) and tumor necrosis factor (TNF)-α levels were measured. Expression of intestinal TNF-α and tight junction protein (ZO-1) proteins was detected by Western blot and/or immunohistochemistry. Serum DAO level and serum and intestinal TNF-α leves were signifi cantly increased after I/R, and the values were markedly reduced by curcumin pretreatment although still higher than that of sham group (p<0.05 or p<0.001). H&E staining showed the significant injury to intestinal mucosa following I/R, and curcumin pretreatment signifi cantly improved the histological structure of intestinal mucosa. I/R insult also induced significantly down-regulated expression of ZO-1, and the eff ect was dramatically attenuated by curcumin-pretreatment. Curcumin may protect the intestine from I/R injury through restoration of the epithelial structure, promotion of the recovery of intestinal permeability, as well as enhancement of ZO-1 protein expression, and this eff ect may be partly attributed to the TNF-α related pathway.

Rectus sheath block for postoperative analgesia in patients with mesenteric vascular occlusion undergoing laparotomy: A randomized single-blinded study

Background:

Acute mesenteric ischemia is a life-threatening vascular emergency that requires early diagnosis, immediate anticoagulation, and intervention to restore mesenteric blood flow adequately.

Aims:

To investigate the effect of rectus sheath block (RSB) for postoperative analgesia in patients with mesenteric vascular occlusion.

Settings and Design:

Forty patients with mesenteric vascular occlusion, American Society of Anesthesiologists physical status I or II or III, scheduled for laparotomy were enrolled in this study.

Subjects and Methods:

Patients were randomized into two groups; control group (C Group) and rectus block group (RB Group). In both groups, general anesthesia was induced fentanyl 1 μg/kg with sleeping dose of propofol and 0.15 mg/kg cisatracurium. Then, anesthesia was maintained with sevoflurane in oxygen 100%. In RB Group, under aseptic condition, RSB guided by ultrasound was performed. Surgery is then continued and intravenous fentanyl patient-controlled analgesia pump started. Postoperative pain, sedation, and opioid side effects were assessed.

Statistical Analysis Used:

Statistical analysis was done using Statistical Package for Social Sciences (SPSS 19.0, Chicago, IL, USA).

Results:

Patients in the RB Group consumed statistically significant less opioid in comparison to control group either intraoperatively or postoperatively. Mean pain scores were statistically significant less in RB Group than in the control group at 2, 4, and 6 h postoperatively. Sedation score, incidence of nausea and vomiting were statistically significant less in the RB Group in comparison to control group. More patients’ satisfaction was reported in the RB Group.

Conclusions:

Ultrasound-guided RSB resulted in postoperative reduction of pain scores and opioid consumption compared with general anesthesia alone. Moreover, RSB was associated with better patient satisfaction and less nausea and vomiting.

Urinary diversion: tailored solutions for individual patients

PURPOSE OF REVIEW

Various urinary diversions are at disposition for reconstructive surgery after cystectomy. The chosen diversion has a strong impact on patients' life regarding complications and quality of life. The purpose of this review is to summarize the current tendency to adapt surgical solutions to individual needs of the patient.

RECENT FINDINGS

Tailored surgery requires that the surgeon has been trained in the handling of all gut segments. Only in this case can he react to anatomical variants, patient comorbidities and oncological circumstances, as well as to the prognosis and the social circumstances of the patient with a tailored diversion. Changing demography and ageing populations with increasing incidence of muscle invasive bladder cancer request new, less invasive methods of urinary diversions. There is little evidence as to which is the best urinary diversion due to a lack of well designed studies.

SUMMARY

The ileum conduit is still the most used urinary diversion worldwide. However, there are multiple techniques available to us, which guarantee the safest solution in combination with the highest quality of life for the construction of tailored urinary diversion.

Origin of cardiomyocytes in the adult heart

This review article discusses the mechanisms of cardiomyogenesis in the adult heart. They include the re-entry of cardiomyocytes into the cell cycle; dedifferentiation of pre-existing cardiomyocytes, which assume an immature replicating cell phenotype; transdifferentiation of hematopoietic stem cells into cardiomyocytes; and cardiomyocytes derived from activation and lineage specification of resident cardiac stem cells. The recognition of the origin of cardiomyocytes is of critical importance for the development of strategies capable of enhancing the growth response of the myocardium; in fact, cell therapy for the decompensated heart has to be based on the acquisition of this fundamental biological knowledge.

Outcome of acute mesenteric ischemia in the intensive care unit: a retrospective, multicenter study of 780 cases

BACKGROUND

In the intensive care unit (ICU), the outcomes of patients with acute mesenteric ischemia (AMI) are poorly documented. This study aimed to determine the risk factors for death in ICU patients with AMI.

METHODS

A retrospective, observational, non-interventional, multicenter study was conducted in 43 ICUs of 38 public institutions in France. From January 2008 to December 2013, all adult patients with a diagnosis of AMI during their hospitalization in ICU were included in a database. The diagnosis was confirmed by at least one of three procedures (computed tomography scan, gastrointestinal endoscopy, or upon surgery). To determine factors associated with ICU death, we established a logistic regression model. Recursive partitioning analysis was applied to construct a decision tree regarding risk factors and their interactions most critical to determining outcomes.

RESULTS

The death rate of the 780 included patients was 58 %. Being older, having a higher sequential organ failure assessment (SOFA) severity score at diagnosis, and a plasma lactate concentration over 2.7 mmol/l at diagnosis were independent risk factors of ICU mortality. In contrast, having a prior history of peripheral vascular disease or an initial surgical treatment were independent protective factors against ICU mortality. Using age and SOFA severity score, we established an ICU mortality score at diagnosis based on the cutoffs provided by recursive partitioning analysis. Probability of survival was statistically different (p < 0.001) between patients with a score from 0 to 2 and those with a score of 3 and 4.

CONCLUSION

Acute mesenteric ischemia in ICU patients was associated with a 58 % ICU death rate. Age and SOFA severity score at diagnosis were risk factors for mortality. Plasma lactate concentration over 2.7 mmol/l was also an independent risk factor, but values in the normal range did not exclude the diagnosis of AMI.

Diagnosis and management of ischemic colitis

The clinical presentation and outcome of ischemic colitis have 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 the colonic mucosa with histologic analysis of biopsies is the gold standard for identification of colonic ischemia. Many 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 colonpathy, and symptomatic intestinal strictures. 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.

Gastrointestinal complications following cardiac surgery with cardiopulmonary bypass

Gastrointestinal complications following cardiac surgery with cardiopulmonary bypass include paralytic ileus, stress ulcer, acute ischemic colitis, gastrointestinal bleeding, acute cholecystitis, acute pancreatitis, acute hepatic failure and so on. Due to the lack of diagnostic tests with high specificity and sensitivity, the early diagnosis of these complications is difficult, which leads to a higher mortality rate. Therefore, accurately identifying the risk factors is important for early diagnosis and treatment. The purpose of this paper is to review the pathogenesis, risk factors, diagnosis and treatment of gastrointestinal complications after cardiac surgery with cardiopulmonary bypass.

Protective effects of L-alpha-glycerylphosphorylcholine on ischaemia-reperfusion-induced inflammatory reactions

PURPOSE

Choline-containing dietary phospholipids, including phosphatidylcholine (PC), may function as anti-inflammatory substances, but the mechanism remains largely unknown. We investigated the effects of L-alpha-glycerylphosphorylcholine (GPC), a deacylated PC derivative, in a rodent model of small intestinal ischaemia-reperfusion (IR) injury.

METHODS

Anaesthetized Sprague-Dawley rats were divided into control, mesenteric IR (45 min mesenteric artery occlusion, followed by 180 min reperfusion), IR with GPC pretreatment (16.56 mg kg⁻¹ GPC i.v., 5 min prior to ischaemia) or IR with GPC post-treatment (16.56 mg kg⁻¹ GPC i.v., 5 min prior to reperfusion) groups. Macrohaemodynamics and microhaemodynamic parameters were measured; intestinal inflammatory markers (xanthine oxidoreductase activity, superoxide and nitrotyrosine levels) and liver ATP contents were determined.

RESULTS

The IR challenge reduced the intestinal intramural red blood cell velocity, increased the mesenteric vascular resistance, the tissue xanthine oxidoreductase activity, the superoxide production, and the nitrotyrosine levels, and the ATP content of the liver was decreased. Exogenous GPC attenuated the macro- and microcirculatory dysfunction and provided significant protection against the radical production resulting from the IR stress. The GPC pretreatment alleviated the hepatic ATP depletion, the reductions in the mean arterial pressure and superior mesenteric artery flow, and similarly to the post-treatments with GPC, also decreased the xanthine oxidoreductase activity, the intestinal superoxide production, the nitrotyrosine level, and normalized the microcirculatory dysfunction.

CONCLUSIONS

These data demonstrate the effectiveness of GPC therapies and provide indirect evidence that the anti-inflammatory effects of PC could be linked to a reaction involving the polar part of the molecule.

HIF-1α Provokes Delayed Neutrophil Apoptosis by Decreasing 24P3 Expression and Intracellular Iron Content

Neutrophil apoptosis is delayed in medical conditions associated to anoxia or hypoxia, prolonging tissue destruction and fostering the inflammation. Hypoxia Inducible Factor-1α (HIF-1α), is a main regulator of delayed neutrophil apoptosis but the mechanism of action is poorly characterized. Neutrophil gelatinase-associated lipocalin (24p3) participates actively in iron metabolism and the regulation of iron-responsive genes. Recently, a connection has been described between HIF-1α and 24p3. The purpose of the present study was to determine whether constitutive apoptosis in neutrophils requires 24p3 and whether HIF-1α represses 24p3 affecting cell death iron intracellular levels. To this end we used in vivo ischemic models and anoxic approaches based on the reactivation of the delayed apoptosis. We found that the stabilization of HIF-α during anoxic periods provoked a delay in neutrophil apoptosis through decrease of 24p3 expression and intracellular iron content. The ischemia drastically inhibited the synthesis of 24p3 in circulating neutrophils, increasing the tissue damage. Reactivation of neutrophil apoptosis with opsonized E.coli induced increases in intracellular levels of iron and 24p3. In conclusion, contrary to other cell types, constitutive apoptosis in neutrophils requires 24p3. During hypoxia or ischemia, HIF-1α stabilization represses 24p3 expression, consequently iron levels are depleted and neutrophil apoptosis is delayed.

The diagnosis of acute mesenteric ischemia: A systematic review and meta-analysis

OBJECTIVES

Acute mesenteric ischemia is an infrequent cause of abdominal pain in emergency department (ED) patients; however, mortality for this condition is high. Rapid diagnosis and surgery are key to survival, but presenting signs are often vague or variable, and there is no pathognomonic laboratory screening test. A systematic review and meta-analysis of the available literature was performed to determine diagnostic test characteristics of patient symptoms, objective signs, laboratory studies, and diagnostic modalities to help rule in or out the diagnosis of acute mesenteric ischemia in the ED.

METHODS

In concordance with published guidelines for systematic reviews, the medical literature was searched for relevant articles. The Quality Assessment Tool for Diagnostic Accuracy Studies-2 (QUADAS-2) for systematic reviews was used to evaluate the overall quality of the trials included. Summary estimates of diagnostic accuracy were computed by using a random-effects model to combine studies. Those studies without data to fully complete a two-by-two table were not included in the meta-analysis portion of the project.

RESULTS

The literature search identified 1,149 potentially relevant studies, of which 23 were included in the final analysis. The quality of the diagnostic studies was highly variable. A total of 1,970 patients were included in the combined population of all included studies. The prevalence of acute mesenteric ischemia ranged from 8% to 60%. There was a pooled sensitivity for l-lactate of 86% (95% confidence interval [CI] = 73% to 94%) and a pooled specificity of 44% (95% CI = 32% to 55%). There was a pooled sensitivity for D-dimer of 96% (95% CI = 89% to 99%) and a pooled specificity of 40% (95% CI = 33% to 47%). For computed tomography (CT), we found a pooled sensitivity of 94% (95% CI = 90% to 97%) and specificity of 95% (95% CI = 93% to 97%). The positive likelihood ratio (+LR) for a positive CT was 17.5 (95% CI = 5.99 to 51.29), and the negative likelihood ratio (-LR) was 0.09 (95% CI = 0.05 to 0.17). The pooled operative mortality rate for mesenteric ischemia was 47% (95% CI = 40% to 54%). Given these findings, the test threshold of 2.1% (below this pretest probability, do not test further) and a treatment threshold of 74% (above this pretest probability, proceed to surgical management) were calculated.

CONCLUSIONS

The quality of the overall literature base for mesenteric ischemia is varied. Signs, symptoms, and laboratory testing are insufficiently diagnostic for the condition. Only CT angiography had adequate accuracy to establish the diagnosis of acute mesenteric ischemia in lieu of laparotomy.

Early detection of acute mesenteric ischemia using diffusion-weighted 3.0-T magnetic resonance imaging in a porcine model

PURPOSE

The aim of this study was to investigate if 3.0-T diffusion-weighted magnetic resonance imaging (MRI) can be used for early detection of acute occlusive and nonocclusive mesenteric ischemia.

MATERIALS AND METHODS

In this study, approved by the official committee on animal affairs, proximal (occlusive) mesenteric ischemia and peripheral (nonocclusive) mesenteric ischemia were induced in 8 and 2, respectively, female domestic pigs. Proximal mesenteric ischemia was induced by intra-arterial injection of n-butyl-cyanoacrylate in the superior mesenteric artery or 1 of its main branches; peripheral mesenteric ischemia was induced by intra-arterial injection of microparticles. Before embolization and at 30-, 60-, and 90-minute intervals after embolization, diffusion-weighted imaging was performed, and apparent diffusion coefficient (ADC) maps were calculated on a clinical 3.0-T system. Immediately after the last MRI session, animals were killed to provide a pathological correlation for mesenteric ischemia.

RESULTS

Ischemic bowel parts appeared hyperintense on diffusion-weighted images and hypointense on the corresponding ADC maps. Mean diffusion-weighted imaging signal intensity increased and ADC decreased significantly within 30 minutes after embolization (P < 0.001) and remained unchanged until 90 minutes after injury, independent of the embolization method.

CONCLUSIONS

3.0-Tesla diffusion-weighted MRI may help detect acute mesenteric ischemia as early as 30 minutes after vessel occlusion.

Local thrombolytic therapy in acute mesenteric ischemia

BACKGROUND

The aim of the study was to evaluate the local thrombolytic therapy (LTT) in combination with laparoscopy, in management of acute mesenteric ischemia (AMI).

METHODS

From January 2000 to January 2010, patients who were admitted to the hospital with AMI due to acute arterial occlusion were analysed retrospectively. Patients presenting with acute abdomen with a suspicion of AMI were evaluated with computerized tomography angiography (CTA). Patients who had findigs of AMI on CTA, were underwent selective mesenteric angiography and LTT eventhough without peritoneal signs. LTT was carried out before or after laparoscopy or laparotomy, and initiated with recombinant plasminogen activator.

RESULTS

LTT was performed in 13 (17.1%), out of 76 patients. From the remaining patients, 56 underwent necrotic bowel resection and 7 underwent tromboembolectomy. The median age was 62 years (45-87). The median duration of symptoms was 24 h. Four (30.7%) patients presented within 24 h onset of symptoms, whilst 9 (69.3%) patients presented after 24 h onset of symptoms. There were 5 (39.5%) patients, who presented with abdominal pain without peritoneal signs on physical examination and 8 (61.5%) patients, who had peritoneal signs. The mortality rate was 20% (1/5) in the first group who presented without peritoneal signs, whilst it was 62.5% (5/8) in the remaining.

CONCLUSION

Early intervention in AMI is the key to better results. CTA combined with early laparoscopy and LTT may have beneficial effects at this setting.

Regenerating new heart with stem cells

This article discusses current understanding of myocardial biology, emphasizing the regeneration potential of the adult human heart and the mechanisms involved. In the last decade, a novel conceptual view has emerged. The heart is no longer considered a postmitotic organ, but is viewed as a self-renewing organ characterized by a resident stem cell compartment responsible for tissue homeostasis and cardiac repair following injury. Additionally, HSCs possess the ability to transdifferentiate and acquire the cardiomyocyte, vascular endothelial, and smooth muscle cell lineages. Both cardiac and hematopoietic stem cells may be used therapeutically in an attempt to reverse the devastating consequences of chronic heart failure of ischemic and nonischemic origin.

Successful recanalization of acute superior mesenteric artery thromboembolic occlusion by a combination of intraarterial thrombolysis and mechanical thrombectomy with a carotid filter

Acute superior mesenteric artery (SMA) occlusion is a life-threatening disease, and acute intestinal ischemia develops from the sudden decrease in perfusion to the intestines. The key to saving the patient's life is early diagnosis, and prompt revascularization of the SMA can prevent intestinal infarction and decrease the risk of bowel segment necrosis. Computed tomographic angiography may be useful for rapid diagnosis. We report recanalization of an SMA occlusion in an 80-year-old man with a combination of intraarterial thrombolysis and mechanical thrombectomy with a carotid filter.

Effects of allopurinol and preconditioning on apoptosis due to ischemia-reperfusion on a double jejunum-segment canine model

PURPOSE

To investigate the duration of apoptosis caused by ischemia-reperfusion in the intestine in a new double jejunum-segment model, and to analyze the protective effects of allopurinol or ischemic preconditioning (IPC).

METHODS

In Experiment I for harvesting the double jejunum-segment model after laparotomy a 30-cm-long jejunum part was selected on mongrel dogs (n=24). End-to-end anastomoses were performed at both ends and in the middle of the jejunum part, creating two equal segments. In one segment ischemia was induced by occluding the supplying vessels, the other segment served as control. Tissue samples for detecting apoptosis were taken at 30th minutes, 1st, 2nd, 4th, 6th, 8th, 12th and 24th hours of reperfusion. In Experiment II using the same model the 4-hour reperfusion time period, allopurinol (50 mg/kg) pre-treated and IPC (3 cycles of 5x1) groups (n=5 per each) were also investigated.

RESULTS

In Experiment I the greatest apoptotic activity was detected at the 4th and 6th hour of reperfusion (14.2 ± 1.31 and 16.3 ± 1.05 per visual field at 40x magnification). In Experiment II Using the 4-hour reperfusion time period allopurinol pre-treatment increased the apoptotic activity (10.72 ± 0.47 per 50 intestinal villi) approximately two-fold than the IPC (6.72 ± 0.46 per 50 intestinal villi) did (p<0.05).

CONCLUSIONS

Apoptotic activity has a characteristic time curve, reaching the highest values between the 4th and 6th hours after 30-minute intestinal ischemia. Ischemic preconditioning seemed to be protective against the morphological changes caused by intestinal ischemia-reperfusion.

Preservation of small bowel with the selective use of heparin and second look laparotomy in acute mesenteric ischaemia: A case report

INTRODUCTION

Acute mesenteric ischaemia may occur due to mesenteric arterial embolus, thrombosis, non-occlusive mesenteric ischaemia or venous thrombosis resulting in ischaemia of the bowel wall.

PRESENTATION OF CASE

A 41year old woman presented with worsening abdominal pain, decreased appetite, nausea and vomiting. Examination revealed right lower quadrant tenderness. Investigations revealed elevation of her inflammatory markers. At laparotomy two separate segments of ischaemic but potentially viable small bowel were identified secondary to mesenteric venous thrombosis. Bowel salvage was attempted with the use of intravenous unfractionated heparin and this was confirmed following a second look laparotomy.

DISCUSSION

Despite a normal platelet count at presentation a diagnosis of JAK-2 positive essential thrombocythaemia was made thus explaining the acquired prothrombotic state underlying the venous thrombosis. The selective use of intravenous unfractionated heparin and second look laparotomy may provide a means for bowel preservation in these cases.

CONCLUSION

This case highlights the potential of bowel salvage can be achieved following an episode of acute mesenteric ischaemia with the use of intravenous unfractionated heparin and selective second look laparotomy and the importance of considering underlying myeloproliferative disease in such cases even in the absence of a thrombocytosis at presentation.

Acute abdominal pain in the older adult

Abdominal pain in older adults is a concerning symptom common to a variety of diagnoses with high morbidity and mortality. Organizing the differential into categories based on pathology (inflammatory, obstructive, vascular, or other causes) provides a framework for the history, physical, and diagnostic studies. An organized approach and treatment and considerations specific to the geriatric population are discussed.

Seven-Tesla micro-MRI in early detection of acute arterial ischaemia: evolution of findings in an in vivo rat model

PURPOSE

Acute mesenteric ischaemia (AMI) is a life-threatening vascular emergency with a high mortality rate. Early diagnosis is the key to reducing its mortality rate and improving the quality of life. Although computed tomography (CT) is still the gold standard for acute intestinal disorders, over the last few years, magnetic resonance imaging (MRI) has become a useful alternative tool. An animal model of AMI was developed in order to study the effectiveness of MRI in early detection of this condition and to observe lesion evolution.

METHODS

Thirty Sprague Dawley rats were randomly divided into two groups (n=15): in the first group, after laparotomy, the animals underwent ligation of the superior mesenteric artery (SMA), followed by macroscopic monitoring and histological evaluation; in the second, ischaemia was induced by squeezing a loop around the SMA 3 days before evaluation with 7-T micro-MRI.

RESULTS

Macroscopically, a reflex spastic ileus followed by reflex hypotonic ileus and colour changes in some of the loops were detected. MRI evidenced luminal dilatation with air-fluid levels, free intraperitoneal fluid and bowelwall oedema. Histological analysis confirmed ischaemia and earlier damage involving the central portion of the ileum.

CONCLUSIONS

This model shows the correct sequence of events during arterial AMI and demonstrates that MRI can be recommended for early diagnosis of these lesions.

Urinary tract infection mimicking acute mesenteric ischaemia in an immunocompromised patient

Bowel infarction due to acute mesenteric ischaemia (AMI) is an abdominal emergency with a high mortality rate. We report a case of exaggerated septic response to a urinary tract infection mimicking AMI in an immunosuppressed diabetic patient. A 56-year-old female was found collapsed at home with a 24 hour history of diarrhoea, a central abdominal pain and a complex past medical history. Examination showed her to be pyrexial, drowsy, profoundly dehydrated with evidence of cardiovascular collapse. She had a tender distended abdomen, raised inflammatory markers, raised lactate of 9.1 u/L and urinalysis was positive for leucocytes and nitrites. An abdominal computed tomography (CT) scan was reported to show small bowel ischaemia. She underwent a negative laparotomy and recovered following management in the intensive therapy unit. The negative laparotomy rate can be reduced by having abdominal CT performed and reported by an experienced radiologist or by the use of diagnostic laparoscopy.

Risk factors for intestinal ischaemia among patients registered in a UK primary care database: a nested case-control study

BACKGROUND

Intestinal ischaemia, including ischaemic colitis and acute mesenteric ischaemia, causes significant morbidity and mortality. Few population-based studies have estimated incidence and potential risk factors for this disease.

AIMS

To estimate the incidence of intestinal ischaemia and identify the associated risk factors in cohorts: (i) patients with irritable bowel syndrome and/or chronic constipation (IBS/CC/both), (ii) individuals free of these conditions.

METHODS

Population-based case-control analysis nested in a cohort of patients with first ever recorded diagnosis of IBS/CC/both and a cohort free of these conditions from general population using the General Practice Research Database.

RESULTS

Of 78 cases of intestinal ischaemia, 71 were from general population, seven from the IBS/CC/both cohort. Incidence rate of intestinal ischaemia in IBS/CC/both patients vs. general population was 4.49:1.09 per 100,000 person-years; age- and gender-adjusted incidence rate ratio (95% CI) was 2.7 (1.2-5.9). Inflammatory bowel disease and heart failure showed an association with ischaemic colitis [OR (95% CI): 4.2 (0.5-38.4) and 5.6 (2.2-14.1)], but none with acute mesenteric ischaemia. Diabetes and prior cardiovascular surgery were associated with higher risk of acute mesenteric ischaemia, but showed no association with ischaemic colitis.

CONCLUSIONS

Results suggest that different risk factors are associated with acute mesenteric ischaemia and ischaemic colitis. However, due to small number of patients, associations should be carefully interpreted.

Protection from glycine at low doses in ischemia-reperfusion injury of the rat small intestine

BACKGROUND

Glycine at high doses is known to protect the small intestine against ischemia-reperfusion (I/R) injury. Here, we studied whether glycine at low clinically applicable doses has a protective effect.

METHODS

In series 1, intestinal I/R was induced in male Wistar rats by occlusion (90 min)/reopening (120 min) of the superior mesenteric artery. Glycine was intravenously infused for 30 min before ischemia (pre-ischemic infusion), and once again from 30 min before until 60 min after reperfusion. Total glycine doses applied over the 120-min infusion were 5, 10, 20, and 75 mg glycine/kg. In series 2, pre-ischemic blood plasma glycine concentrations were determined under the conditions of series 1.

RESULTS

In series 1, attenuation of I/R injury was comparable at 10, 20, and 75 mg glycine/kg, but less at 5 mg/kg (as indicated by less intestinal hemorrhages and better preserved mean arterial blood pressure, among other signs). In series 2, pre-ischemic blood plasma glycine concentrations increased with increasing glycine doses from 280 to 330, 340, 380, and 680 μM, respectively.

CONCLUSION

These results demonstrate that even at a dose 50 times lower than previously applied - and at only slightly elevated plasma concentrations - glycine provides full protection against I/R injury of the small intestine.