Acute Occlusive Mesenteric Ischemia Research Articles

Safety, Efficacy and Outcome of Rotational Thrombectomy assisted Endovascular Revascularisation of the Superior Mesenteric Artery in Acute Thromboembolic Mesenteric Ischaemia.

To evaluate the efficacy and safety of percutaneous rotational thrombectomy-assisted endovascular revascularization of acute thromboembolic superior mesenteric artery occlusions in acute mesenteric ischemia. Fifteen cases of percutaneous rotational thrombectomy- assisted (Rotarex S, BD, USA) revascularization were retrospectively analyzed. The etiology was embolic in 40 % of cases and thrombotic in 60 %. A "Thrombectomy in Visceral Ischemia" (TIVI) 5-point score determined vessel patency at presentation, after percutaneous rotational thrombectomy, and after adjunctive technologies. TIVI 3 indicated nearly complete revascularization (minimal residual side branch thrombus). TIVI 4 indicated complete revascularization. Technical success was defined as successful device application and a final TIVI score of 3/4 after adjunctive technologies. Safety and outcome were also analyzed. Device application via femoral access was feasible in 100 % of cases and improved flow in 86.7 % of cases (1 × TIVI 0→1, 11 × TIVI 0→2, 1 × TIVI 1→2). There was no change in 13.3 % of cases (2 × TIVI 2→2). Additional devices resulted in further flow improvement in 93.3 % of cases (8 × TIVI 3, 6 × TIVI 4). One recanalization failed (TIVI 2→2→2). After adjunctive technologies (10 × manual aspiration, 11 × angioplasty, 9 × stenting), the technical success rate was 93.3 %. The mean procedure time was 40.5(± 14) minutes for embolism and 72.1(± 20) minutes for thrombosis. There was one device-related major complication (catheter tip fracture) resulting in a device-related safety rate of 93.3 %. The overall major complication rate was 20 %. Surgical exploration (13 ×), bowel resection (9 ×) and Fogarty embolectomy/bypass (3 ×) were also performed. The 30-day mortality rate was 40 %. Percutaneous rotational thrombectomy is an effective adjunct for rapid endovascular recanalization of acute thromboembolic superior mesenteric artery occlusions with an acceptable rate of major procedural complications. · Percutaneous rotational thrombectomy-assisted superior mesenteric artery revascularization in acute occlusive mesenteric ischemia is feasible and effective.. · Percutaneous rotational thrombectomy facilitates rapid flow restoration in native and stented superior mesenteric artery segments.. · Brachial access should be considered in the case of steep take-off angles of the superior mesenteric artery..

Factors that may affect the outcome of acute occlusive mesenteric ischemia. A single-center study

BackgroundAcute mesenteric ischemia is a rare but lethal disease. Acute occlusive mesenteric ischemia consists of mesenteric artery embolism, mesenteric artery thrombosis, and mesenteric vein thrombosis. This study aimed to investigate the factors that may affect the outcome of acute occlusive mesenteric ischemia.MethodsData from acute occlusive mesenteric ischemia patients admitted between May 2016 and May 2022 were reviewed retrospectively. Patients were divided into 2 groups according to whether complications(Clavien‒Dindo ≥ 2) occurred within 6 months of the first admission. Demographics, symptoms, signs, laboratory results, computed tomography angiography features, management and outcomes were analyzed.Results59 patients were enrolled in this study. Complications(Clavien‒Dindo ≥ 2) occurred within 6 months of the first admission in 17 patients. Transmural intestinal necrosis, peritonitis, white blood cell count, percentage of neutrophils, percentage of lymphocytes, neutrophil-to-lymphocyte ratio, lactate dehydrogenase, creatine kinase isoenzyme, cardiac troponin I, laparoscopic exploration rate, open embolectomy rate, enterostomy rate, length of necrotic small bowel, length of healthy small bowel, surgical time and intraoperative blood loss differed significantly between groups. Creatine kinase isoenzyme (OR = 1.415, 95% CI: 1.060–1.888) and surgical time (OR = 1.014, 95% CI: 1.001–1.026) were independent risk factors associated with complications(Clavien‒Dindo ≥ 2).ConclusionsOur analysis suggests that acute occlusive mesenteric ischemia patients with a creatine kinase isoenzyme level greater than 2.22 ng/mL or a surgical time longer than 156 min are more likely to experience complications’(Clavien‒Dindo ≥ 2) occurrence within 6 months of the first admission.

Long-term outcome after implementation of endovascular-first strategy to treat acute mesenteric ischemia

ObjectiveTo evaluate the rationale of an aggressive endovascular-first strategy to treat elderly patients with acute mesenteric ischemia (AMI) by studying long-term survival, readmissions, and patients’ discharge to home vs nursing facility a decade after an episode of AMI. MethodsThe retrospective study cohort included 66 consecutive patients (all-comers) treated for arterial occlusive AMI between 2009 and 2013. Endovascular revascularization (EVR) was attempted in 50 patients (EVR+), whereas 16 patients were treated without attempted revascularization (EVR−). All patients were followed until death or September 2022. Studied outcomes included discharge status, long-term survival and cause of death and readmissions related to AMI. ResultsThe mean age of all 66 patients was 78 ± 10 years: 79 ± 9 years in the EVR+ group and 76 ± 12 years in the EVR− group. EVR was technically successful in 44 patients (88%); three patients underwent subsequent open revascularization after EVR failure. One-third required bowel resection after EVR. The 30-day mortality for all patients was 44%; 32% in the EVR+ group and 81% in the EVR− group. Only two survivors were permanently institutionalized, whereas all others were discharged to the same place they lived prior to the AMI episode. There were four AMI-related readmissions during the follow-up; all were in the EVR+ group. Two patients underwent reinterventions for recurrent AMI. One-year survival was 52% for EVR+ and 19% for EVR− patients. Five-year survival rates were 18% and 13%, respectively. The causes of deaths were mesenteric ischemia in 22, other cardiovascular event in 21, and non-cardiovascular cause in 19 patients. Four patients were alive at the end of the follow-up. ConclusionsIn this unselected elderly population with AMI, the aggressive strategy to attempt EVR resulted in a high revascularization rate and favorable outcomes. The high proportion of patients returning to their prior living status and low readmission rate after survival from AMI encourages active treatment of high-functioning elderly patients.

Small bowel transmural necrosis secondary to acute mesenteric ischemia and strangulated obstruction: CT findings of 49 patients

Rationale and objectivesTransmural bowel necrosis (TBN) is an uncommon surgical emergency that represents an endpoint of occlusive acute mesenteric ischemia (AMI), nonocclusive AMI and small bowel obstruction (SBO). According to limited evidence, each etiology of TBN might demonstrate a different CT finding. This investigation aimed to 1) identify overall CT findings of TBN, and 2) compare CT findings of TBN in each etiology. Materials and methodsForty-nine consecutive adults (mean age, 64.6 years; 26 men) with occlusive AMI, nonocclusive AMI or SBO, and pathologically proven TBN were enrolled. All had a CT scan within 24 h before surgery. Clinical information was compiled from medical records. CT examinations were re-reviewed by two radiologists with disagreements resolved by the third radiologist. Data were analyzed and compared. ResultsTransmural bowel necrosis were secondary to arterial AMI, venous AMI, combined arterial and venous AMI, nonocclusive AMI, and SBO in 6, 5, 2, 10, and 26 patients, respectively. The CT findings were ascites (93.9%), abnormal wall enhancement (91.8%), bowel dilatation (89.8%), mesenteric fat stranding (89.8%), abnormal wall thickness (71.5%), pneumatosis (46.9%) and intrinsic hyperattenuation of bowel walls (22.5%). Portovenous gas, mesenteric venous gas, and pneumoperitoneum were present in 4 patients (8.2%). Bowel wall thickness was the only CT findings that showed a statistically significant difference among the 5 etiologies of TBN (P = 0.046). ConclusionsMost common CT findings of TBN were ascites, abnormal bowel wall enhancement, dilatation, and mesenteric fat stranding. Wall thickness differentiated five etiologies, being most thickened in venous AMI and normal in arterial AMI.

Radiological predictive factors of transmural intestinal necrosis in acute mesenteric ischemia: systematic review and meta-analysis.

Transmural intestinal necrosis (TIN) is related to high mortality in patients with acute mesenteric ischemia (AMI). Radiological predictive factors of TIN in AMI remains controversial. This study aimed to identify the CT-based predictive factors of TIN in AMI. EMBASE and PUBMED were searched for publications predicting TIN using radiological features. Quality Assessment of Diagnostic Accuracy Studies-2 was used to assess the methodological quality of individual studies. Data were presented in terms of diagnostic odds ratio (DOR), sensitivity, specificity, and 95% confidence interval (CI). The random-effects models were used for the meta-analysis. Eleven studies including 1037 cases with AMI were considered. The meta-analysis showed that bowel wall thinning (DOR = 13.10; 95% CI: 3.71, 46.25), decreased or absent bowel wall enhancement (DOR = 5.77; 95% CI: 2.95, 11.30), bowel dilation (DOR = 3.23; 95% CI: 2.03, 5.15), pneumatosis intestinalis (DOR = 5.78; 95% CI: 2.24, 14.95), porto-mesenteric venous gas (DOR = 5.36; 95% CI: 2.14, 13.40), and arterial occlusive AMI (DOR = 2.66; 95% CI: 1.53, 4.63) were risk factors for predicting TIN. Bowel wall thinning and porto-mesenteric venous gas displayed high specificity to diagnose TIN (98%, 95%, respectively). The subgroup analysis showed that decreased or absent bowel wall enhancement (DOR = 8.23; 95% CI: 4.67, 14.51) and bowel dilation (DOR = 3.14; 95% CI: 1.55, 6.39) were predictors of TIN in venous occlusive AMI, which were not related to TIN in arterial-origin AMI. For predicting TIN, there are specific radiological features. The radiological predictors of TIN may differ according to the various causes of AMI. Future primary studies should further evaluate the relationships between radiological signs and TIN based on different etiologies. • Bowel wall thinning, decreased or absent bowel wall enhancement, bowel dilation, pneumatosis intestinalis, porto-mesenteric venous gas, and arterial occlusive AMI were risk factors for predicting TIN. • Decreased or absent bowel wall enhancement and bowel dilation were predictors of TIN in venous occlusive AMI, which were not related to TIN in arterial-origin AMI.

S3304 Acute Occlusive Mesenteric Ischemia From Venous and Aortic Thrombosis in a Patient with Hyperhomocysteinemia and Liver Cirrhosis

Introduction: Portal vein thrombosis (PVT) is a severe complication of liver cirrhosis and one of its major consequences include intestinal ischemia. Hyperhomocysteinemia (HHcy) has been suggested to be an independent risk factor for deep venous thrombosis, but limited data are available on the prevalence of HHcy in patients with PVT complicating liver cirrhosis. Several clinical studies have also demonstrated the role of HHcy in arterial and venous thrombosis. Case Description/Methods: We report a case of a 57 year old male with Liver Cirrhosis from Alcoholic Liver Disease, who presented at our ED with a two week history of dull periumbilical pain which worsened on the day of consult. Plain abdominal CT scan showed nonspecific small bowel enteritis. He was placed on general liquid diet and started on Ciprofloxacin and Metronidazole intravenously. However, on the third hospital day, he complained of sudden severe abdominal pain accompanied by abdominal distention, guarding, and direct and rebound tenderness on all quadrants. He had hypotension and on laboratory workup, had decreasing hemoglobin levels with elevated WBC count and lactate. Contrast-enhanced abdominal CT scan revealed portal and superior mesenteric vein thrombosis, bowel wall ischemia along the segment of the jejenum in the left hemiabdomen, and infrarenal abdominal aorta and ascending aorta thrombi. Emergency exploratory laparotomy was done with segmental jejunoileal resection and primary end-to-end anastomosis with intraoperative findings of gangrenous small bowels measuring 100 cm in length, with the rest of the proximal small bowels noted to be dilated and edematous. The patient was transferred to the intensive care unit post-operatively for closer monitoring; Heparin drip was started 24 hours post-surgery. Histopathology results showed extensive transmural infarction, hemorrhage, and necrosis on small bowel segments; organizing thrombi were seen on mesenteric vessels. The patient was worked-up for other causes of hypercoagulable states which showed elevated Homocysteine levels at 20.6 (NV: 5-12). Discussion: It is likely that HHcy may increase the risk of patients with liver cirrhosis to develop arterial and venous thrombosis considering the pivotal role the liver plays in the metabolism of sulphur amino acids and Hcy-related vitamin storage. Therefore, identification of this high-risk group may be important to plan prevention management, such as vitamin supplementation, other Hcy-lowering strategies, or long-term anticoagulation.

Relationship of superior mesenteric artery thrombus density with transmural intestinal necrosis on multidetector computed tomography in acute mesenteric ischemia.

Acute arterial occlusive mesenteric ischemia with transmural intestinal necrosis (TIN) is a fatal disease, which is difficult to diagnose on multidetector computed tomography (MDCT). The aim of the present study was to determine the relationship of superior mesenteric artery (SMA) thrombus density with TIN on MDCT in patients with acute mesenteric ischemia (AMI) due to SMA thromboembolism. In this retrospective study, 33 patients who underwent abdominal MDCT and angiography for AMI due to SMA thromboembolism were divided into two groups: the AMI with TIN group and the AMI without TIN group. We analyzed the relationships of clinical characteristics, qualitative MDCT signs, and SMA thrombus density with TIN. The SMA thrombus density was measured on non-contrast MDCT. Univariate and multivariate analyses were performed to determine the risk factors for predicting TIN. The diagnostic performances of risk factors were evaluated by receiver-operating characteristic (ROC) curve analysis. Of the patients with AMI enrolled in this study, 33.3% (11/33) were diagnosed with TIN. Peritonitis (P=0.042), bowel wall thinning (P=0.033), and pneumatosis/portomesenteric gas (P=0.010) were significantly associated with TIN. AMI patients with TIN exhibited a higher SMA thrombus density than AMI patients without TIN [41.2±6.1 vs. 34.2±3.0 Hounsfield unit (HU), P=0.003]. Multivariate analysis showed that SMA thrombus density was an independent predictor of TIN [P=0.044, hazard ratio (HR): 1.82, 95% confidence interval (CI): 1.02-3.25]. For diagnosing AMI with TIN, the area under the ROC curve (AUC) of SMA thrombus density (0.83) was larger than those of peritonitis (0.68), bowel wall thinning (0.66), and pneumatosis/portomesenteric gas (0.71). In patients with AMI, erythrocyte-rich thrombus blocking the SMA trunk which has a higher density on MDCT is prone to the occurrence of TIN compared with erythrocyte-scarce thrombus with a lower density. SMA thrombus density could be an independent risk factor for TIN in patients with AMI due to SMA thromboembolism.

The implementation of a pathway and care bundle for the management of acute occlusive arterial mesenteric ischemia reduced mortality.

Acute mesenteric ischemia (AMI) is a disease with high mortality and requires a multidisciplinary approach for effective management. A pathway and care bundle were developed and implemented with the objective to reduce mortality. The aim of this retrospective comparative study was to analyze the effects of the pathway on patient management and outcome. All consecutive patients operated in a secondary and tertiary referral center because of occlusive arterial AMI were identified between 2014 and April 2020. The pathway aimed to increase overall awareness, and hasten and improve diagnostics and management. Patients treated before implementation of the pathway (pregroup, years 2014-2017) were compared with patients treated using the pathway (postgroup, May 2018 to April 2020). Univariate and multivariate analyses were used to compare the groups. There were 78 patients in the pregroup and 67 patients in the postgroup with comparable baseline characteristics and disease acuity. The postgroup was more often diagnosed with contrast-enhanced computed tomography (58 [74%] vs. 63 [94%], p = 0.001) and had shorter mean in-hospital delay to operating room (7 hours [interquartile range, 3.5-12.5] vs. 3 hours [interquartile range, 2-11], p = 0.023). Revascularization was done more often in the postgroup (53 [68%] vs. 56 [84%], p = 0.030) especially using endovascular treatment (26 [33%] vs. 43 [64%], p < 0.001). Thirty-day mortality was lower in the postgroup (23 [51%] vs. 17 [25%], p = 0.001). Being managed in the postgroup remained as a protective factor (odds ratio, 0.32; 95% confidence interval, 0.14-0.75; p = 0.008) for 30-day mortality in the multivariate analysis. Implementing a pathway and care bundle resulted in enhanced regional and in-hospital awareness of AMI, more appropriate computed tomography imaging, shorter in-hospital delays, increased number of revascularizations, and, hence, lower mortality. Therapeutic/Care Management, level IV.

Evaluating the Risk of Irreversible Intestinal Necrosis Among Critically Ill Patients With Nonocclusive Mesenteric Ischemia.

To identify factors associated with irreversible transmural necrosis (ITN) among critically ill patients experiencing nonocclusive mesenteric ischemia (NOMI) and to compare the predictive value regarding ITN risk stratification with that of the previously described Clichy score. All consecutive patients admitted to the intensive care unit between 2009 and 2019 who underwent exploratory laparotomy for NOMI and who had an available contrast-enhanced computed tomography with at least 1 portal venous phase were evaluated for inclusion. Clinical, laboratory, and radiological variables were collected. ITN was assessed on pathological reports of surgical specimens and/or on laparotomy findings in cases of open-close surgery. Factors associated with ITN were identified by univariate and multivariate analysis to derive a NOMI-ITN score. This score was further compared with the Clichy score. We identified 4 factors associated with ITN in the context of NOMI: absence of bowel enhancement, bowel thinning, plasma bicarbonate concentration ≤15 mmol/L, and prothrombin rate <40%. These factors were included in a new NOMI-ITN score, with 1 point attributed for each variable. ITN was observed in 6%, 38%, 65%, 88%, and 100% of patients with NOMI-ITN score ranging from 0 to 4, respectively. The NOMI-ITN score outperformed the Clichy score for the prediction of ITN (area under the receiver operating characteristics curve 0.882 [95% confidence interval 0.826-0.938] vs 0.674 [95% confidence interval 0.582-0.766], respectively, P < 0.001). We propose a new 4-point score aimed at stratifying risk of ITN in patients with NOMI. The Clichy score should be applied to patients with occlusive acute mesenteric ischemia only.

Unusual arterial thrombotic events in Covid-19 patients

IntroductionCOVID-19 infection is commonly complicated with pro-thrombotic state and endothelial dysfunction. While several studies reported a high incidence of venous thromboembolic events. The occurrence of arterial thromboses are yet rarely described and could be underestimated. ObjectivesTo describe the clinical and biological characteristics of COVID-19 patients presenting with an associated arterial thromboembolic event. Material and methodsWe performed a retrospective multicentric study in 3 centers between France and Italy. All patients with a confirmed SARS-CoV-2 infection and arterial thromboembolic events were included in the analysis. ResultsFrom March 8th to April 25th 2020, we identified 20 patients (24 events) with arterial thromboembolic events over 209 admitted patients (9.6%) with severe COVID-19 infection. Arterial thrombotic events included acute coronary occlusions (n = 9), stroke (n = 6), limb ischemia (n = 3), splenic infarcts (n = 3), aortic thrombosis (n = 2) and occlusive mesenteric ischemia (n = 1). At the time of the event, 10/20 (50%) of patients received thromboprohylaxis, 2/20 (10%) were receiving treatment dose anticoagulation and 5/20 (25%) were receiving antiplatelet therapy. ConclusionOur observations suggest that serious arterial thrombotic events might occur in Covid-19 patients. However, the exact incidence of such events and the best way to prevent them yet remains to be investigated.

Transmural Bowel Necrosis From Acute Mesenteric Ischemia and Strangulated Small-Bowel Obstruction: Distinctive CT Features.

OBJECTIVE. The purpose of this study was to assess whether transmural bowel necrosis has distinct CT features based on the three main causes: occlusive acute mesenteric ischemia (AMI), nonocclusive AMI, and strangulated small-bowel obstruction (SBO). MATERIALS AND METHODS. From January 2010 to December 2017, the records of all patients with a pathologic diagnosis of transmural bowel necrosis were extracted from the pathology department database of a university hospital. The inclusion criteria for the study were presence of transmural bowel necrosis at pathologic examination and available contrast-enhanced CT images obtained within the 24 hours before surgery. Seventy-seven patients were finally included. The CT scans were retrospectively independently reviewed by two abdominal radiologists to identify the classic CT findings of transmural bowel necrosis. Statistical analyses were performed. RESULTS. Pneumatosis intestinalis was statistically more frequent in nonocclusive AMI (59%) than in occlusive AMI (29%) and strangulated SBO (7%) (p < 0.01), as were superior mesenteric venous gas (55%, 29%, and 0%; p < 0.01) and portal venous gas (48%, 10%, and 0%; p < 0.01). Decreased or absent bowel wall enhancement was more frequent in AMI than in SBO (nonocclusive AMI, 83%; occlusive AMI, 81%; SBO, 56%; p = 0.02), as was thinned bowel wall (nonocclusive AMI, 52%; occlusive AMI, 48%; SBO, 18%; p = 0.02). Spontaneous hyperattenuation of the bowel wall was more frequent in strangulated SBO (41%) than in nonocclusive AMI (10%) and occlusive AMI (14%) (p < 0.01). CONCLUSION. Transmural bowel necrosis has distinct CT findings according to its three main causes. Occlusive AMI is characterized by an absence of bowel wall enhancement and less mesenteric fat stranding, nonocclusive AMI by a high prevalence of pneumatosis intestinalis and portal venous gas, and strangulated SBO by spontaneous hyperattenuation of the bowel wall and an absence of pneumatosis intestinalis and portal venous gas.

Utility of biphasic multi-detector computed tomography in suspected acute mesenteric ischemia in the emergency department.

To retrospectively evaluate the utility of biphasic multi-detector computed tomography (MDCT) with arterial and portal venous phases for the detection of suspected acute mesenteric ischemia (AMI) in emergency department (ED) patients compared to limited surgical confirmation. A research ethics board (REB)-approved retrospective review of all consecutive adult patients who underwent an emergency biphasic 64-MDCT examination of the abdomen and pelvis due to clinical suspicion for AMI over a 5-year period at a single tertiary-care institution was performed. Patients who underwent biphasic 64-MDCT scans performed for any clinical concern other than suspected acute mesenteric ischemia were excluded. Specifically, reported vascular and bowel findings were used to establish occlusive arterial, venous, and non-occlusive MDCT findings of AMI. Correlation was made with surgical findings in operatively managed patients and with serum lactate values preceding imaging assessment. Diagnostic yield and positive predictive value calculations were performed. Two hundred and twenty-five patients underwent MDCT for suspected occlusive AMI between 10 Jan 2011 and 31Jul 2016. Of these, 200 patients were negative for AMI and 25 patients (mean age 73.5years; age range 48 to 94years; 13 men and 12 women) had MDCT findings positive for bowel ischemia (yield of 11.1%). On MDCT, 18/25 (72%) had an occlusive arterial etiology for AMI, 2/25 (8%) had an occlusive venous etiology, and 5/25 (20%) had non-occlusive AMI. Twenty of 25 (80%) patients with positive MDCT findings of AMI also had an elevated serum lactate level, including 14/18 (77.8%) patients with arterial occlusive AMI on MDCT, 2/2 (100%) with venous-occlusive AMI on MDCT, and 4/5 (80%) with non-occlusive AMI on MDCT. Correlation with surgical findings led to a positive predictive value (PPV) of biphasic MDCT for surgically proven all-cause occlusive ischemia of 92.9%. Further substratification revealed PPVs of arterial and venous-occlusive ischemia of 85.7% and 7.1%, respectively. Of the 225 patients MDCT-positive for AMI, 213 had pre-imaging serum lactate assessments. Of 188 patients MDCT-negative for AMI, 85 patients had elevated serum lactate (45.2%). Twenty of the 25 patients with positive MDCT findings of AMI (80%) also had an elevated serum lactate level, including 14/18 (77.8%) patients with arterial occlusive AMI on MDCT, 2/2 (100%) with venous-occlusive AMI on MDCT, and 4/5 (80%) with non-occlusive AMI on MDCT. Emergent biphasic MDCT demonstrated low but non-trivial yield (11.1%) for the depiction of suspected acute mesenteric ischemia but was particularly low for occlusive venous AMI (0.9%). The relationship between serum lactate elevation and positive MDCT findings of AMI in our study conforms to prior work and cautiously suggests value in routine serum lactate assessment preceding imaging for patient prioritization.

Кишечная стенка при острой ишемии: данные прижизненной оптической когерентной томографии и гистологического анализа

The objective is to study the morphometric signs of small bowel ischemic damage basing on intravital optical coherence tomography data and further histological analysis Materials and methods. The study was carried out on male Wistar rats with the use of two models of acute intestinal ischemia: acute occlusive mesenteric ischemia by а. jejunales ligation (group “I”) and acute arteriovenous ischemia by a small bowel loop and frill strangulation together with а. et v. jejunales (group “II”). The state of intramural vessels in vivo was evaluated with the use of optical coherence angiography (OCA). After the macroscopic signs of non-viability appeared the bowel was resected and its stepwise histological analysis was carried out. Results. Ischemic damage development in group “I” was accompanied by decrease of bowel wall thickness by 34,8-42,4% (p=0,032) due to submucous layer destruction - based on histological analysis data and also by decrease of total length of functioning intramural vessels by 4,6% (p=0,004) - based on OCA data. According to the OCA data in group “II” the length of functioning vessels decreased by 89,6%in the strangulated bowel loop and by 6,1% in adducent and abducent sections (p=0,001). In the strangulated loop histological specimens sharply dilated thrombosed veins were seen in all layers of bowel wall, seromuscular layer oedema and diapedesis hemorrhages of mucous coat also took place as well as bowel wall thickening by 25,2% in comparison with the intact one. Conclusions. Сomplex analysis of in vivo optical coherence tomography results and further histological analysis of ischemic small bowel wall made it possible to determine the morphological manifestations which are specific for arterial and arteriovenous mesenteric blood flow disorder. In cases of mesenteric artery occlusion hypoperfusion and mucous coat ischemia are predominant among pathogenetic mechanisms of bowel wall alteration. In the strangulated bowel the main factor of destruction and necrosis is acute insufficiency of venous outflow.

Pathomorphological manifestations of ischemic involvement of the small intestine in acute occlusion of the mesenteric artery

Relevance. Lethality rates (63-95%) among patients with acute intestinal ischemia remain consistently high during the last decades. Despite the high urgency of the problem and numerous works devoted to visualization, early laboratory and instrumental diagnostics of ischemic bowel disease, clinical results have not changed significantly during the last 15-20 years. Pathogenetic mechanisms of various variants of ischemic intestinal lesion and their pathomorphological manifestations should become the basis for the development of surgical tactics and require specification.&#x0D; The aim is to study pathomorphological manifestations and to clarify on their basis the pathogenetic mechanisms of ischemic involvement of the small intestine in acute occlusion of the mesenteric artery in the experiment.&#x0D; Materials and methods. An experimental study was performed on 10 laboratory animals - male rats of the Wistar line. Modeling acute mesenteric ischemia was carried out via dressing of the jejunal artery. The ischemic intestine was collected for a stepwise histological study, the morphometry of the layers of the intestinal wall and the prevalence of necrosis.&#x0D; Results. At the time of the appearance of macroscopic signs of lack of vitality in the central sector of the ischemic intestine, the wall thickness was 47.6% less than normal and in the adjacent peripheral sectors by 40.6%. Thinning of the intestinal wall was due to alteration of the mucosa with a decrease in its share in the total wall thickness from 86 to 82% (p = 0.021) in all sectors. The share of area occupied by necrosis in groups "B" and "C" was not statistically significant (p = 0.872) and amounted to 17.1 [7.3; 64.9]%. The state of the intramural vessels of the intestinal wall had significantly changed in comparison with the intact intestine. Signs of hypoperfusion in the form of sludge in the microvessels of the mucous membrane and the submucosa had been revealed.&#x0D; Conclusions. Pathomorphological manifestations of ischemic bowel disease in acute occlusive mesenteric ischemia resulted in a decrease in the total thickness of the wall and a change in the ratio of serous-muscular and mucosal-submucosal layers due to a decrease in the proportion of the latter. The severity of necrosis in the central and peripheral parts of the ischemic intestine did not differ.

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

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. 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. 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. 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.

What is the Best Revascularization Strategy for Acute Occlusive Arterial Mesenteric Ischemia: Systematic Review and Meta-analysis.

Acute mesenteric ischemia (AMI) is a life-threatening disease that leads to bowel infarction and death. The optimal management of AMI remains controversial. The present meta-analysis aimed to estimate the prognostic impact of surgical (SG) versus endovascular or hybrid intervention (EV) as the first-line treatment for acute arterial occlusive mesenteric ischemia and to assess whether endovascular strategy was actually effective in reducing bowel resection. MEDLINE, Scopus and the Cochrane Library databases were searched. There have been no randomized controlled trials comparing SG versus EV for the treatment of AMI. We undertook this systematic review and meta-analysis according to MOOSE (Meta-analysis of Observational Studies in Epidemiology) guidelines, assessing the included study quality with the Newcastle-Ottawa scale. Seven studies comparing EV versus SG as first strategy for the treatment of AMI were selected for the analyses, reporting of 3020 patients. EV was associated with a reduced risk of in-hospital mortality (RR 0.68; 95% CI 0.59-0.79; fixed-effects analysis; p<0.0001; I 2=4.9%; τ 2=0.025). Pooled prevalence of mortality was 19% for EV and 34% for SG. EV also showed a benefit impact on risk of bowel resection and second-look laparotomy. The present meta-analysis outlines that endovascular revascularization strategy seems to offer advantages in terms of in-hospital mortality and morbidity in case of arterial occlusive AMI. A multidisciplinary team consisting of radiologists, interventional radiologists, cardiovascular and general surgeons comes out to be essential to tailor the right procedure to the patient and improve the outcomes associated with AMI.

The Role of Enteric Glia Cells in Intestinal Regeneration After Mesenteric Ischemia and Reperfusion

Background: Acute occlusive mesenteric ischemia is a life-threatening disease and remains to be incompletely understood in modern gastrointestinal surgery. Recently it has been shown, that specifically enteric glia cells (EGCs) are important to maintain epithelial homeostasis in the intestine. After EGC ablation, lethal intestinal inflammation occurs. EGCs of various subtypes and locations interact with the gut microbiome, synthesize trophic factors (i.e. TGF-ß, GDNF) and potentially protect enteric neurons from I/R and oxidative stress. We hypothesize that EGC function may therefore be pivotal for regeneration of epithelial integrity, cell protection and recovery of intestinal function after I/R. EGC activation after intestinal ischemia and reperfusion (I/R) has been suggested, but the relevance of such a reactive “gliosis” in the intestine in analogy to an “astrocytosis” in the brain (i.e. after ischemic stroke) is not fully understood. We therefore aim to investigate the role of EGCs after I/R. Methods: We studied a superior mesenteric artery (SMA)-occlusion model in C57Bl/6 mice as well as in GFAP-GFP and GFAP-Td-Tomato reporter-mice, using the glial fibrillary acidic protein GFAP as an EGC marker. Anesthetized mice underwent median laparotomy and the SMA was identified and occluded with a microvascular clamp for 45 minutes. Intestinal samples were procured after 3 hours and 24 hours of reperfusion. To assess I/R injury, Parks’ score was performed in H/E stained paraffin slides and a standardized segment of ileum was tested for FITC dextran diffusion in an in-vitro assay confirming epithelial barrier breakdown. Immunofluorescence staining in intestinal whole mounts was performed for EGC markers. Intestinal samples were also analyzed for EGC related gene expression in the tunica muscularis. For further mechanistic studies, primary EGC cultures were established and subjected to in-vitro ischemic conditions. Results: Parks’ score showed a significant I/R injury in the intestines of SMA-clamped animals at both timepoints, concomitant to an epithelial barrier breakdown as tested in an in-vitro FITC dextran diffusion assay, compared to sham animals. Immunfluorescence staining of the EGC marker GFAP in intestinal tunica muscularis whole mounts showed a morphologic upregulation of GFAP filaments after 45 minutes of intestinal ischemia at 3h and 24h of reperfusion (mean fluorescence intensity MFI: clamp3h vs. sham3h and clamp24h vs. sham24; One Way Anova p<0.001). GFAP gene expression in the tunica muscularis of animals with SMA-clamping was significantly upregulated after 3h of reperfusion. Furthermore, in GFAP reporter mice (GFAP-GFP) gene expression of the well-established transcription factor and hypoxia marker HIF1-α was significantly upregulated after 3h and 24h of reperfusion (clamp3h vs. sham3h, unpaired t-test p<0.05; clamp24h vs. sham24h, unpaired t-test p<0.01), concomitantly to HIF1-α dependent genes such as TGFß1 and VEGF-α. It was also found, that several proinflammatory cytokines (IL-6, Il-1ß) and chemokines (MCP-1) were significantly upregulated after limited mesenteric ischemia both in the animal and in-vitro models.FigureFigureConclusion: Mesenteric ischemia and reperfusion activates GFAP-positive EGC potentially via HIF-1α dependent pathways and produces an inflammatory micro-environment. Further study of the interactions of EGC and the intestinal epithelium may provide new insights into the regenerative mechanisms of the bowel after limited mesenteric ischemia.

Increased activity of Factor VIII causing acute intestinal ischemic disorder with recurrent and multiple arterial thromboses

Acute intestinal ischemic disorders are potentially life threatening, making early diagnosis and emergency surgery crucial. Although hypercoagulability may induce mesenteric venous thrombosis, its association with mesenteric arterial thromboembolism remains controversial. We present the case of a 52-year-old man with hypercoagulability-induced acute arterial occlusive mesenteric ischemia. The patient suffered from arterial occlusive mesenteric ischemia, recent ischemic stroke, and previous renal infarction. He had no history of atrial fibrillation, atherosclerosis, vascular diseases, autoimmune diseases, malignancy, liver diseases, copper deficiency, or other risk factors for arterial thromboembolism. Segmental resection of the gangrenous bowel with primary end-to-end anastomosis was performed. A pathological examination revealed multiple thrombi within the mesenteric arteries of the infarcted bowel without apparent atherosclerosis of the vessels. The plasma level of factor VIII was high even 64 months postoperatively, which may have contributed to the recurrent and multiple arterial thromboses. A lifelong oral anticoagulation therapy was suggested. From our experience, we recommend that thrombophilia screening be performed in patients with acute intestinal ischemic disorders, particularly in those with a history of recurrent or multiple thromboembolism. Anticoagulant therapy should be prescribed for those with hypercoagulability.

Prevalence , Pattern of Presentation , Risk Factors and Outcome of Acute Mesenteric Venous Thrombosis in Taif Province , Saudi Arabia : A Single Center Study

Background and aim of the study: Mesenteric venous thrombosis has a global incidence of 10-15% of all cases of mesenteric ischemia; however reports from high altitude provinces of Saudi Arabia as Taif and Aseer recorded an incidence above 60%. The aim of this study is to record the incidence, pattern of presentation, risk factors; diagnostic tools and outcome of treatment in a single center (King Abdul Aziz Specialist Hospital) Taif, Saudi Arabia. Material and method: In this retrospective chart review study, we reviewed the records and data of all patients presented to King Abdul Aziz Specialist Hospital, Taif, Saudi Arabia from January 2009 to January 2013 and their final diagnosis were proved to be acute mesenteric venous thrombosis. Traumatic, postoperative and non occlusive cases were excluded from the study. Results:Sixteen patients with final diagnosis of acute mesenteric venous thrombosis were included in this study, out of 26 patients (61.5%) presented and diagnosed as acute occlusive mesenteric ischemia. Males were more affected than females. The mean age of the patients was 55±13.4 years. The mean duration of symptoms was 4.9±1.4 days.The most common presenting symptoms were; abdominal pain followed by nausea, vomiting, anorexia, bloody diarrhea and fever. The most prevalent physical findings was tachycardia followed by ileus, 5 patients presented by marked peritoneal signs 3 of them were shocked. Multiple risk factors were detected in all patients. Laboratory findings were not conclusive and diagnosis was established by CT angiography in most of the patients. During operation, all patients were found to have a segment of infarction of the small intestine and in one of them the cecum was involved. Resection of the gangrenous parts was done for all patients. Second look operation was performed in 25% of patients. The total mortality was 18.75%. Conclusion: Acute mesenteric venous thrombosis is the most common cause of acute occlusive mesenteric ischemia in Taif province and this may be related to multiple risk factors. Being familiar with this disease is essential in making the correct diagnosis to be followed by prompt resuscitation with heparinization to be continued postoperatively to prevent recurrent thrombosis. Laparotomy should be performed as soon as metabolic and hemodynamic correction is done with resection of any infracted segment. A second look operation may be required. If these steps are followed strictly and without delay, the prognosis of mesenteric venous thrombosis is often favorable.

Effects of a Multimodal Management Strategy for Acute Mesenteric Ischemia on Survival and Intestinal Failure

Acute mesenteric ischemia (AMI) is an emergency with a high mortality rate; survivors have high rates of intestinal failure. We performed a prospective study to assess a multidisciplinary and multimodal management approach, focused on intestinal viability. In an Intestinal Stroke Center, we developed a multimodal management strategy involving gastroenterologists, vascular and abdominal surgeons, radiologists, and intensive care specialists; it was tested in a pilot study on 18 consecutive patients with occlusive AMI, admitted to a tertiary center from July 2009 to November 2011. Patients with left ischemic colitis, nonocclusive AMI, chronic mesenteric ischemia, and other emergencies were excluded. Patients received specific medical management: revascularization of viable small bowel and/or resection of nonviable small bowel; 12 patients received arterial revascularization. We evaluated the percentages of patients who survived for 30 days or 2 years, the number with permanent intestinal failure, and morbidity. Lengths and rates of intestinal resection were compared with or without revascularization, and in patients with early or late-stage disease. Patients were followed up for a mean of 497 days (range, 7-2085 d); 95% survived for 30 days, 89% survived for 2 years, and 28% had morbidities within 30 days. Intestinal resection was necessary for 7 cases (39%), with mean lengths of intestinal resection of 30 cm and 207 cm, with or without revascularization, respectively (P = .03). Among patients with early or late-stage AMI, rates of resection were 18% and 71%, respectively (P = .049). Patients with early stage disease had shorter lengths of intestinal resection than those with late-stage disease (7 vs 94 cm; P = .02), and spent less time in intensive care (2.5 vs 49.8; P = .02). A multidisciplinary and multimodal management approach might increase survival of patients with AMI and prevent intestinal failure.