Acute mesenteric ischemia: guidelines of the World Society of Emergency Surgery

Intracranial Hypertension following Acute Mesenteric Ischemia: A Case Study on the Multiple Compartment Syndrome

In this case study, we describe a 25-year-old male who was admitted due to a severe traumatic brain injury, requiring invasive intracranial pressure monitoring. At 48 hours posttrauma, he developed intracranial hypertension refractory to medical treatment without tomographic changes in the brain. Subsequently, intra-abdominal hypertension and tomographic signs of abdominal surgical pathology were observed. An exploratory laparotomy was performed with an intraoperative diagnosis of acute mesenteric ischemia. After surgical intervention for the abdominal pathology, intracranial pressure was restored to physiological values with a favorable recovery of the patient. In this report, the relationship between intracranial pressure and intra-abdominal pressure is discussed, highlighting the delicate association between the brain, abdomen, and thorax. Measures should be taken to avoid increases in intra-abdominal pressure in neurocritical patients. When treating intracranial hypertension refractory to conventional measures, abdominal causes and multiple compartment syndrome must be considered. The cranial compartment has physiological interdependence with other body compartments, where one can be modified by variations from another, giving rise to the concept of multiple compartment syndrome. Understanding this relationship is fundamental for a comprehensive approach of the neurocritical patient. To the best of our knowledge, this is the first report of a comatose patient post-traumatic brain injury, who developed medically unresponsive intracranial hypertension secondary to acute mesenteric ischemia, in which surgical resolution of intra-abdominal pathology resulted in intracranial pressure normalization and restitutio ad integrum of neurological status.

Mesenteric ischaemia in a case of acute anterior myocardial infarction: overlap of ischaemic types

Acute mesenteric ischaemia is divided into different clinical entities which are usually considered separately. Here we report a case of acute mesenteric ischaemia complicated with acute anterior myocardial infarction. The clinical picture suggested that non-occlusive mesenteric ischaemia and acute mesenteric arterial thrombosis were both present in this case. Thus, non-occlusive and occlusive ischaemia may coexist in a coordinated and perceptible pattern.

Non-Occlusive Mesenteric Ischemia in Cardiac Arrest Patients

Non-occlusive mesenteric ischemia (NOMI) is a severe complication in patients after cardiac arrest (CA). The diagnosis is complicated, the treatment options are limited. Given the susceptibility of enterocytes to ischemia, the incidence and severity of NOMI in the post-resuscitation period may reflect the intensity and duration of both ischemia and subsequent reperfusion injury. NOMI is considered to be associated with adverse neurological outcomes in CA patients. Therefore, NOMI should not only be regarded as a post-resuscitation complication but also as one of the prognostic markers in CA patients.This paper summarizes current knowledge on NOMI's pathophysiology, diagnosis, treatment, and prognostic significance in CA patients.

The Association of Polish Surgeons (APS) clinical guidelines for the use of laparoscopy in the management of abdominal emergencies. Part II

Introduction

Over the past three decades, almost every type of abdominal surgery has been performed and refined using the laparoscopic technique. Surgeons are applying it for more procedures, which not so long ago were performed only in the classical way. The position of laparoscopic surgery is therefore well established, and in many operations it is currently the recommended and dominant method.

Aim

The aim of the preparation of these guidelines was to concisely summarize the current knowledge on laparoscopy in acute abdominal diseases for the purposes of the continuous training of surgeons and to create a reference for opinions.

Material and methods

The development of these recommendations is based on a review of the available literature from the PubMed, Medline, EMBASE and Cochrane Library databases from 1985 to 2022, with particular emphasis on systematic reviews and clinical recommendations of recognized scientific societies. The recommendations were formulated in a directive form and evaluated by a group of experts using the Delphi method.

Results and conclusions

There are 63 recommendations divided into 12 sections: diagnostic laparoscopy, perforated ulcer, acute pancreatitis, incarcerated hernia, acute cholecystitis, acute appendicitis, acute mesenteric ischemia, abdominal trauma, bowel obstruction, diverticulitis, laparoscopy in pregnancy, and postoperative complications requiring emergency surgery. Each recommendation was supported by scientific evidence and supplemented with expert comments. The guidelines were created on the initiative of the Videosurgery Chapter of the Association of Polish Surgeons and are recommended by the national consultant in the field of general surgery. The second part of the guidelines covers sections 6 to12 and the following challenges for surgical practice: acute appendicitis, acute mesenteric ischemia, abdominal injuries, bowel obstruction, diverticulitis, laparoscopy in pregnancy and postoperative complications requiring a reoperation.

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.

Successful treatment of nonocclusive mesenteric ischemia in a reconstructed jejunum after esophagectomy and remnant gastric tube resection: a case report

BACKGROUND

Nonocclusive mesenteric ischemia (NOMI), an ischemic bowel disease without a disruption of the mesenteric blood flow or strangulation of the mesentery or intestine, may cause a lethal clinical course. We report a very rare case of jejunal necrosis caused by NOMI in the pedicled mesentery of the reconstructed jejunum after remnant gastric tube resection for heterochronous gastric tube cancer after esophagectomy.

CASE PRESENTATION

An 80-year-old man visited our department with chief complaints of fever and appetite loss after 4 months from gastric tube resection and digestive reconstruction with pedicled jejunum. Contrast-enhanced computed tomography (CT) revealed impaired blood flow without torsion of the mesentery, severe wall thickness, and micro-penetration in the reconstructed jejunum and combined pyothorax in the right thoracic cavity. Esophagogastroduodenoscopy demonstrated extensive mucosal necrosis confined to the jejunum, which was elevated in the thoracic cavity. The jejunal necrosis due to NOMI occurring in the reconstructed jejunum was suspected, and lifesaving small bowel resection with right thoracotomy was considered necessary. However, radical operation with right thoracotomy was considered to be excessively invasive and not valid due to the patient's poor physical status, advanced age, and presence of left adrenal metastasis from the remnant gastric cancer. Therefore, we selected the conservative treatment with fasting, transnasal drainage, and administration of antibiotics due to the patient's intention. CT-guided right thoracic drainage for the intrathoracic abscess was needed 10 days after starting treatment and the inflammatory response rapidly improved. Follow-up CT and esophagogastroduodenoscopy revealed the improvement in the ischemic changes in jejunal mucosa without perforation. Intake was initiated at 20 days after symptom onset, and the patient was discharged at 40 hospital days without any complications and sequelae.

CONCLUSIONS

To the best of our knowledge, this is the first case of NOMI occurring in the reconstructed jejunum after remnant gastric tube resection that was successfully treated with a conservative treatment. For NOMI, it is important to make appropriate diagnosis based on imaging findings and perform proper assessment of the patient's condition. Conservative treatments may be also useful depending on the patient's condition.

A Case of Chronic Mesenteric Ischemia Due to Celiac and Mesenteric Artery Thrombosis

Chronic mesenteric ischemia (CMI) is uncommon and accounts for approximately 5% of cases. CMI presents with non-specific symptoms, making it difficult to diagnose, and requires complex management involving interprofessional teams. We present the case of a 66-year-old female who presented with postprandial abdominal pain, vomiting, sitophobia, and weight loss. Investigations showed raised inflammatory markers, and plain film X-ray and endoscopy showed no significant findings. CT angiogram showed celiac and mesenteric artery thrombosis. The patient proceeded to have endovascular revascularization. With this case, we highlight the importance of considering CMI in an elderly patient with a history of microvascular disease or risk factors presenting with postprandial abdominal pain and weight loss. Early diagnosis and timely intervention are imperative for a good prognosis.

Hypercoagulability status, operative mortality, and long-term survival in patients operated on for mesenteric venous thrombosis

OBJECTIVE

Mesenteric venous thrombosis (MVT) is a rare cause of acute surgical abdomen, with high mortality. The aim of this study was to analyze long-term outcomes and possible factors influencing its prognosis.

METHODS

All patients who underwent urgent surgery for MVT from 1990 to 2020 in our center were reviewed. Epidemiological, clinical, and surgical data; postoperative outcomes; origin of thrombosis; and long-term survival were analyzed. Patients were divided into two groups: primary MVT (hypercoagulability disorders or idiopathic MVT) and secondary MVT (underlying disease).

RESULTS

Fifty-five patients, 36 (65.5%) men and 19 (34.5%) women, mean age 66.7 years (standard deviation: ±18.0 years), underwent surgery for MVT. Arterial hypertension (63.6%) was the most prevalent comorbidity. Regarding the possible origin of MVT, 41 (74.5%) patients had primary MVT and 14 (25.5%) patients had secondary MVT. From these, 11 (20%) patients had hypercoagulable states, 7 (12.7%) had neoplasia, 4 (7.3%) had abdominal infection, 3 (5.5%) had liver cirrhosis, 1 (1.8%) patient had recurrent pulmonary thromboembolism, and 1 (1.8%) had deep venous thrombosis. Computed tomography was diagnostic of MVT in 87.9% of the cases. Intestinal resection was performed in 45 patients due to ischemia. Only 6 patients (10.9%) had no complication, 17 patients (30.9%) presented minor complications, and 32 patients (58.2%) presented severe complications according to the Clavien-Dindo classification. Operative mortality was 23.6%. In univariate analysis, comorbidity measured by the Charlson index (P = .019) and massive ischemia (P = .002) were related to operative mortality. The probability of being alive at 1, 3, and 5 years was 66.4%, 57.9%, and 51.0%, respectively. In univariate analysis of survival, age (P < .001), comorbidity (P < .001), and type of MVT (P = .003) were associated with a good prognosis. Age (P = .002; hazard ratio: 1.05, 95% confidence interval: 1.02-1.09) and comorbidity (P = .019; hazard ratio: 1.28, 95% confidence interval: 1.04-1.57) behaved as independent prognostic factors for survival.

CONCLUSIONS

Surgical MVT continues to show high lethality. Age and comorbidity according to the Charlson index correlate well with mortality risk. Primary MVT tends to have a better prognosis than secondary MVT.

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

Rationale and objectives

Transmural 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 methods

Forty-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.

Results

Transmural 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).

Conclusions

Most 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.

[Acute mesenteric ischemia-An overview and recommendations (S2k analogous) of the World Society of Emergency Surgery]

Acute mesenteric ischemia is a severe illness, which if untreated, rapidly leads to a critical condition with sepsis, multiple organ failure and death in affected patients. The diagnosis and initiation of treatment of acute mesenteric ischemia should be performed as early and expeditiously as possible and follows the principle of the shortest possible time to reperfusion. Otherwise, the outcome of the patient rapidly deteriorates. The treatment algorithm should be adapted to the pathogenesis of the ischemia, the clinical condition and symptoms of the patients. With clinical signs of peritonitis, intestinal gangrene must be assumed and the abdomen should be surgically explored to detect and treat possible foci of sepsis at an early stage. The treatment of acute mesenteric ischemia should always be performed by an interdisciplinary team with all surgical and interventional options for intestinal revascularization as well as comprehensive intensive care medicine according to the standards of the Intestinal Stroke Center described in the literature. A short duration to revascularization and treatment in this interdisciplinary concept improves the outcome of patients with acute mesenteric ischemia. The World Society of Emergency Surgery provides expert consensus-based recommendations for the diagnosis and treatment of acute mesenteric ischemia; however, there is still a significant lack of broad high-quality evidence for this critical illness. Recommendations of the German specialist societies are urgently needed to ensure appropriate care, from the initial diagnostics to treatment and aftercare, for patients with suspected mesenteric ischemia in this country.

Improving clinical suspicion of acute mesenteric ischemia among patients with acute abdomen: a cross-sectional study from an intestinal stroke center

BACKGROUND

Early diagnosis of acute mesenteric ischemia (AMI) is essential for a favorable outcome. Selection of patients requiring a dedicated multiphasic computed tomography (CT) scan remains a clinical challenge.

METHODS

In this cross-sectional diagnostic study conducted from 2016 to 2018, we compared the presentation of AMI patients admitted to an intestinal stroke center to patients with acute abdominal pain of another origin admitted to the emergency room (controls).

RESULTS

We included 137 patients-52 with AMI and 85 controls. Patients with AMI [median age: 65 years (interquartile range 55-74)] had arterial and venous AMI in 65% and 35% of cases, respectively. Relative to controls, AMI patients were significantly older, more likely to have risk factors or a history of cardiovascular disease, and more likely to present with sudden-onset and morphine-requiring abdominal pain, hematochezia, guarding, organ dysfunction, higher white blood cell and neutrophil counts, and higher plasma C-reactive protein (CRP) and procalcitonin concentrations. On multivariate analysis, two independent factors were associated with the diagnosis of AMI: the sudden-onset (OR = 20, 95%CI 7-60, p < 0.001) and the morphine-requiring nature of the acute abdominal pain (OR = 6, 95%CI 2-16, p = 0.002). Sudden-onset and/or morphine-requiring abdominal pain was present in 88% of AMI patients versus 28% in controls (p < 0.001). The area under the receiver operating characteristic curve for the diagnosis of AMI was 0.84 (95%CI 0.77-0.91), depending on the number of factors.

CONCLUSIONS

Sudden onset and the need for morphine are suggestive of AMI in patients with acute abdominal pain and should prompt multiphasic CT scan including arterial and venous phase images for confirmation.

Strengthening the Description of Superior Mesenteric Artery Occlusions in Acute Mesenteric Ischaemia: Proposition for an Anatomical Classification

OBJECTIVE

The aim of this study was to propose computed tomography angiography (CTA) based anatomical segmentation of the superior mesenteric artery (SMA), in order to standardise the reporting of occlusive lesions in acute mesenteric ischaemia (AMI).

METHODS

A retrospective CTA evaluation of patients with occlusive AMI admitted between 2016 and 2021. After the screening of 468 patients, 95 were included. The SMA was segmented into proximal (S1, ostium to the inferior pancreaticoduodenal artery), middle (S2, from the inferior pancreaticoduodenal to the ileocolic artery), and distal (S3, downstream the ileocolic artery) sections. The jejunal arteries were labelled J1 to J6, and the middle, right, and ileocolic arteries C1, C2, and C3. Two radiologists independently applied the proposed segmentation to a cohort of patients with occlusive AMI to describe occlusive lesions. Intra- and inter-rater agreement was assessed with kappa statistics.

RESULTS

Occlusions involved one segment in 50 (53%) patients (S1, n = 27 [28%]; S2, n = 12 [13%]; S3, n = 11 [12%]); two segments in 37 (39%) patients (S2/S3, n = 31 [33%]; S1/S2, n = 3 [3%]; S1/S3, n = 3 [3%]); and all three segments in eight patients (S1/S2/S3, 8%). The median number of jejunal arteries was four (interquartile range 3, 4.5). C1 and C2 were present in 93 (98%) and 23 patients (24%), respectively. Almost perfect intra-rater agreement was obtained for S1 (91% agreement, κ = 0.82, 95% confidence interval [CI] 0.72 - 0.92); substantial agreement was obtained for S2 (90% agreement, κ = 0.80, 95% CI 0.68 - 0.92) and S3 (86% agreement, κ = 0.72, 95% CI 0.58 - 0.86). Almost perfect inter-rater agreement (with the second junior reading) was obtained for S1 (97% agreement, κ = 0.95, 95% CI 0.89 - 1.0), S2 (91% agreement, κ = 0.82, 95% CI 0.72 - 0.92), and S3 (agreement 96%, κ = 0.91, 95% CI 0.83 - 0.99).

CONCLUSION

A standardised CTA based anatomical segmental description of SMA occlusive lesions in AMI is proposed; it provided substantial to almost perfect intra- and inter-rater agreement for most anatomical segments.

First Line of Defense: The Vital Role of Family Medicine Physicians in Preventing Acute Mesenteric Ischemia in High-Risk Patients

Acute mesenteric ischemia (AMI) is a life-threatening condition with a high mortality rate despite surgical interventions. Morbidity and mortality are especially high in those with risk factors, which include diabetes mellitus (DM), hypertension (HTN), coronary artery disease, recent myocardial infarction, and rheumatic autoimmune diseases, among others. We present the case of a 70-year-old Caucasian woman diagnosed with AMI. The patient presented acutely to the emergency department after nine episodes of vomiting and was admitted to the surgical floor the same day for an emergent exploratory laparotomy. She presented acutely with an atypical presentation and without any progressive symptoms, despite various comorbidities. This patient was classified as "very high risk", but she had not been on any medications or monitored for any of her comorbidities. We highlight the essential and multifaceted role of family medicine physicians, also known as primary care physicians (PCPs), in the prevention of bowel ischemia and recommend the use of routine outpatient monitoring with clinical examination, blood testing, and imaging. These, along with a high index of suspicion, have clinical utility in preventing hospitalization, surgical intervention (bowel resection), and other serious sequelae of AMI. Timely detection, management, and specialist referrals from a family medicine physician can lower the overall burden on healthcare resources and personnel.

Exploring Outcomes Related to Residential Determinants in Acute Mesenteric Ischemia Patients

INTRODUCTION

To access the relationship between residential status and outcomes in surgical acute mesenteric ischemia (AMI) patients.

METHODS

Retrospective chart review of 153 AMI patients admitted to our institution between 2007 and 2021. Residential median income and Rural-Urban Commuting Area (RUCA) code were used as residential proxies.

RESULTS

Being of the female sex (odds ratio [OR] = 3.116 [1.276-7.609] P = 0.013) and having a vascular intervention performed (OR = 2.927 [1.087-7.883] P = 0.034) were both associated with a threefold increase in the risk of mortality. Increased age (OR = 1.037 [1.002-1.073] P = 0.039), elevated blood urea nitrogen (OR = 1.032 [1.012-1.051] P = 0.001), and living in higher residential income area (OR = 1.049 [1.009-1.091] P = 0.017) had a small, but statistically significant, increased risk of mortality. Patients in higher median income areas were less likely to undergo colonic resection (OR = 0.953 [0.911-0.997] P = 0.038) and tended to have a lower likelihood of receiving an ostomy (OR = 0.963 [0.927-1] P = 0.051). Being from urban or rural areas was not associated with mortality (OR = 1.565 [0.647-3.790] P = 0.321, although rural patients were more likely to undergo colon resection (OR = 2.183 [0.938-5.079] P = 0.070). Furthermore, rural patients were much more likely to be readmitted than urban dwellers (OR = 4.700 [1.022-21.618] P = 0.047).

CONCLUSIONS

AMI patients living in rural or small-town areas were more likely to be readmitted and tended to undergo colonic resection. Patients residing in higher income areas had a slightly higher risk of mortality but tended to be less likely to require ostomy or colonic resection. These findings suggest a potential need for postoperative care initiatives focused on AMI patients living in rural and lower income areas.

Antibiotic use in acute mesenteric ischemia: a review of the evidence and call to action

Acute mesenteric ischemia (AMI) is a life-threatening condition with a high mortality rate. The standard practice after making the diagnosis includes aggressive resuscitation, anticoagulation, followed by revascularization and resection of necrotic bowel. The role of empiric antibiotics in the management of AMI is not well defined in the literature. This review article aims to examine our current understanding on this matter, based on bench research and clinical studies. It is demonstrated in animal study model that the ischemia/reperfusion (I/R) injury damages intestinal epithelium, and subsequently lead to barrier dysfunction, a condition that can support bacterial translocation through a complex interplay between the intestinal epithelium, the intestinal immune system and the intestine's endogenous bacterial population. Based on this mechanism, it is possible that the use of antibiotics may help mitigate the consequences of I/R injury, which is examined in few animal studies. In clinical practice, many guidelines support the use of prophylactic antibiotics, based on a meta-analysis of randomized control trials (RCTs) demonstrating the benefit of antibiotics in multi-organ dysfunction syndrome. However, there is no direct reference to AMI in this meta-analysis. Most clinical studies that focus on AMI and mentions the use of antibiotics are retrospective and single institution, and very few comments on the role of antibiotics in their discussions. We conclude that there is limited evidence in literature to support the use of prophylactic antibiotic in AMI to improve outcome. More clinical studies with high level of evidence and basic science research are needed to improve our understanding on this topic and ultimately help build a better clinical pathway for patients with AMI.

Intraluminal oxygen mitigates acute mesenteric ischaemia: a systematic review of methods and outcomes in animal studies

BACKGROUND

Acute Mesenteric Ischaemic (AMI) is a rare condition with significant morbidity and mortality. Many causes of AMI exist, which usually begin with mucosal injury. Onset is insiduous and there is frequent diagnostic delay. Current treatments can only control established injury and prevent propagation, hence new interventions are needed. The prevention and treatment of AMI by intraluminal delivery of oxygen has yet to be investigated in the clinical setting. This article aims to systemically review experimental studies investigating this novel therapy.

METHODS

Following the PRISMA guidelines, searches of PubMed and Ovid MEDLINE databases were performed up to June 2022. Two independent investigators extracted the data.

RESULTS

There were 20 experimental studies, 16 of which used an occlusive ischaemia reperfusion model. Six different formulations were used to deliver intraluminal oxygen, with perflurocarbon being the most common. Studies consistently showed local and systemic benefits. Intraluminal oxygen therapy improved histological severity of mucosal injury in all studies when oxygen was delivered during the ischaemia phase, but could cause harm if given during the reperfusion phase. Improvement was also demonstrated in endpoints assessing intestinal function, biomarkers of intestinal damage, measures of systemic physiological derangement and mortality.

CONCLUSION

Intraluminal oxygenation appears to be an effective treatment for AMI. There remain significant questions regarding optimal timing and delivery formulation before clinical translation of this treatment strategy.

Management of acute mesenteric ischaemia: Results of a worldwide survey

BACKGROUND

Acute mesenteric ischaemia (AMI) is a condition with high mortality. This survey assesses current attitudes and practices to manage AMI worldwide.

METHODS

A questionnaire survey about the practices of diagnosing and managing AMI, endorsed by several specialist societies, was sent to different medical specialists and hospitals worldwide. Data from individual health care professionals and from medical teams were collected.

RESULTS

We collected 493 individual forms from 71 countries and 94 team forms from 34 countries. Almost half of respondents were surgeons, and most of the responding teams (70%) were led by surgeons. Most of the respondents indicated that diagnosis of AMI is often delayed but rarely missed. Emergency revascularisation is often considered for patients with AMI but rarely in cases of transmural ischaemia (intestinal infarction). Responses from team hospitals with a dedicated special unit (14 team forms) indicated more aggressive revascularisation. Abdominopelvic CT-scan with intravenous contrast was suggested as the most useful diagnostic test, indicated by approximately 90% of respondents. Medical history and risk factors were thought to be more important in diagnosis of AMI without transmural ischaemia, whereas for intestinal infarction, plasma lactate concentrations and surgical exploration were considered more useful. In elderly patients, a palliative approach is often chosen over extensive bowel resection. There was a large variability in anticoagulant treatment, as well as in timing of surgery to restore bowel continuity.

CONCLUSIONS

Delayed diagnosis of AMI is common despite wide availability of an adequate imaging modality, i.e. CT-scan. Large variability in treatment approaches exists, indicating the need for updated guidelines. Increased awareness and knowledge of AMI may improve current practice until more robust evidence becomes available. Adherence to the existing guidelines may help in improving differences in treatment and outcomes.

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

OBJECTIVE

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

KEY POINTS

• 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.

FAR Ratio as Prognostic Biomarker in AMI

Acute mesenteric ischemia (AMI) is a vascular emergency resulting from decreased blood flow caused by the occlusion of the mesenteric vessels, hypoperfusion, or vasospasm. This study aimed to investigate the prognostic value of the fibrinogen-to-albumin (FAR) ratio in patients with acute mesenteric ischemia. A total of 91 patients were enrolled in the study. Patients' demographics such as age and gender, pre- and postoperative hemoglobin, CRP, white blood cell (WBC), neutrophils, preoperative lymphocyte, alanine transaminase (ALT), aspartate transaminase (AST), thrombocytes, and postoperative D-dimer values were recorded. In addition, pre- and postoperative fibrinogen and albumin levels were recorded, and FAR was calculated. Patients were divided into two groups, survivors and non-survivors. The mean pre- and postoperative fibrinogen levels were statistically significantly higher in the non-survivor group than in the survivor group (p < 0.001). The mean pre- and postoperative albumin levels were significantly lower in the non-survivors than in the survivors (p = 0.059, p < 0.001; respectively). The mean pre- and postoperative FAR ratios were considerably higher in the non-survivor than in the survivor groups (p < 0.001). The change between pre- and postoperative fibrinogen, albumin, and FAR values was statistically significant between the non-survivors and the survivors (for all, p < 0.05). The preoperative and postoperative fibrinogen levels were significantly lower, and albumin levels were significantly higher in the survivor compared to the non-survivor patients with AMI. Furthermore, the preoperative and postoperative FAR ratio was significantly higher in the non-survivors. The FAR ratio may be a valuable prognostic biomarker for patients with AMI.

Infarcts and ischemia in the abdomen: an imaging perspective with an emphasis on cross-sectional imaging findings

Infarcts and ischemia of abdominal organs may present with acute abdominal pain, and early diagnosis is crucial to prevent morbidity and mortality. Unfortunately, some of these patients present in poor clinical conditions to the emergency department, and imaging specialists are crucial for optimal outcomes. Although the radiological diagnosis of abdominal infarcts is often straightforward, it is vital to use the appropriate imaging modalities and correct imaging techniques for their detection. Additionally, some non-infarct-related abdominal pathologies may mimic infarcts, cause diagnostic confusion, and result in delayed diagnosis or misdiagnosis. In this article, we aimed to outline the general imaging approach, present cross-sectional imaging findings of infarcts and ischemia in several abdominal organs, including but not limited to, liver, spleen, kidneys, adrenals, omentum, and intestinal segments with relevant vascular anatomy, discuss possible differential diagnoses and emphasize important clinical/radiological clues that may assist radiologists in the diagnostic process.

Acute mesenteric ischemia and COVID-19: an integrative review of the literature

The novel coronavirus disease 2019 (COVID-19) has spread rapidly around the world after the first cases were reported in December 2019 in China. Despite the prevention of the symptoms presented, extrapulmonary manifestations were identified. In particular, there was an increase in cases of Acute Mesenteric Ischemia (AMI), raising its incidence to 1.9%-3.8% in infected patients. The aim of this study was to investigate the existence of an association between IMA and COVID-19 through the literature. An Integrative Literature Review was carried out. The research question was "mesenteric ischemia in patients with COVID-19: coincidence or association?". After searching the database and applying the inclusion and exclusion criteria, 44 were selected for analysis. COVID-19 was confirmed by RT-PCR and imaging tests, gastrointestinal manifestations, alterations and primarily tomographic imaging findings were identified. Most patients were accelerated to laparotomy. As explanations include direct endothelial and injury by the binding of the ACE-2 virus, between hyperinflammation and hypercoagulability, dysregulation of the renin-angiotensin-aldosterone system and factors associated with the severity of the virus. IMA is an emergency with high associated morbidity and mortality, these cases may be a consequence mainly of the thromboinflammatory mechanism associated with SARS-CoV-2. An early diagnosis, diagnosis and diagnoses are crucial to clinical treatment; an assessment regime should be considered in accordance with current evidence and guidelines.

Immediate postoperative parenteral anticoagulant therapy in patients with mesenteric ischemia after intestinal resection: a retrospective cohort study at a single institute

BACKGROUND

Bowel gangrene represents a major fatal event in acute mesenteric ischemia. Intestinal resection is inevitable in patients with peritonitis and bowel gangrene. This retrospective study aimed to elucidate the benefit of postoperative parenteral anticoagulation in patients with intestinal resection.

METHODS

Patients with acute mesenteric ischemia and bowel gangrene were recruited retrospectively between January 2007 and December 2019. All patients underwent bowel resection. They were categorized into two groups: patients without immediate parenteral anticoagulant therapy (Group A) and those with immediate parenteral anticoagulant therapy (Group B). Thirty-day mortality and survival were analyzed.

RESULTS

A total of 85 patients were included, with 29 patients in Group A and 56 patients in Group B. Patients in Group B had lower 30-day mortality (16.1%) and a higher 2-year survival rate (45.4%) than patients in Group A (30-day mortality: 51.7%, p = 0.001; 2-year survival rate: 19.0%, p = 0.001). In the 30-day mortality multivariate analysis, patients in Group B had a better outcome (odds ratio = 0.080, 95% confidence interval between 0.011 and 0.605, p = 0.014). Patients in Group B also had a better outcome in the survival multivariate analysis (hazard ratio: 0.435, 95% confidence interval between 0.213 and 0.887, p = 0.022).

CONCLUSIONS

Immediate postoperative parenteral anticoagulant therapy improves prognosis in patients with acute mesenteric ischemia treated by intestinal resection. Trial registration This research was retrospectively approved by the Institutional Review Board (IRB) I&II of Taichung Veterans General Hospital (TCVGH-IRB No.CE21256B) on July 28th, 2021. The informed consent waiver was also approved by IRB I&II of Taichung Veterans General Hospital. The Declaration of Helsinki and ICH-GCP guidelines were followed during this study.

Optical Coherence Tomography Angiography of the Intestine: How to Prevent Motion Artifacts in Open and Laparoscopic Surgery?

(1) Introduction. The problem that limits the intraoperative use of OCTA for the intestinal circulation diagnostics is the low informative value of OCTA images containing too many motion artifacts. The aim of this study is to evaluate the efficiency and safety of the developed unit for the prevention of the appearance of motion artifacts in the OCTA images of the intestine in both open and laparoscopic surgery in the experiment; (2) Methods. A high-speed spectral-domain multimodal optical coherence tomograph (IAP RAS, Russia) operating at a wavelength of 1310 nm with a spectral width of 100 μm and a power of 2 mW was used. The developed unit was tested in two groups of experimental animals—on minipigs (group I, n = 10, open abdomen) and on rabbits (group II, n = 10, laparoscopy). Acute mesenteric ischemia was modeled and then 1 h later the small intestine underwent OCTA evaluation. A total of 400 OCTA images of the intact and ischemic small intestine were obtained and analyzed. The quality of the obtained OCTA images was evaluated based on the score proposed in 2020 by the group of Magnin M. (3) Results. Without stabilization, OCTA images of the intestine tissues were informative only in 32–44% of cases in open surgery and in 14–22% of cases in laparoscopic surgery. A vacuum bowel stabilizer with a pressure deficit of 22–25 mm Hg significantly reduced the number of motion artifacts. As a result, the proportion of informative OCTA images in open surgery increased up to 86.5% (Χ2 = 200.2, p = 0.001), and in laparoscopy up to 60% (Χ2 = 148.3, p = 0.001). (4) Conclusions. The used vacuum tissue stabilizer enabled a significant increase in the proportion of informative OCTA images by significantly reducing the motion artifacts.

High risk and low prevalence diseases: Mesenteric ischemia

INTRODUCTION

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

OBJECTIVE

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

DISCUSSION

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

CONCLUSIONS

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

Spontaneous dissection of the superior mesenteric artery related to COVID-19

Background: Spontaneous peripheral dissections are rare, and in a substantial number of cases, the underlying aetiology remains unclear. Patients and methods: We report the case of a 63-year-old male patient with a recent asymptomatic SARS-CoV-2 infection who presented with sudden-onset intermittent abdominal pain. Imaging studies revealed a dissection of the superior mesenteric artery (SMA) and large-vessel vasculitis involving the SMA as well as the carotid, subclavian, axillary and femoropopliteal arteries. In the absence of other predisposing factors, we supposed an association with prior COVID-19 and performed a systematic review of the literature to search for similar cases with arterial dissection related to acute or recent SARS-CoV-2 infection. Results: We identified 25 cases, including ours: 13 males and 12 females, with a median age of 48 years. In 22/25 patients, arterial dissection occurred within 4 weeks after the diagnosis of COVID-19 and involved the cerebral (11/25; 44%), coronary (10/25; 40%), splanchnic (3/25; 12%) and renal (2/25; 8%) arteries. Conclusions: Although initially known for its respiratory manifestations, it has become evident that SARS-CoV-2 not only infects pneumocytes but also enters the vascular endothelium, leading to endothelial dysfunction and hypercoagulability and - as shown in our case - large-vessel vasculitis, which may predispose patients to intramural haemorrhage and arterial dissection.

Kinetics of d-lactate and ischemia-modified albumin after abdominal aortic surgery and their ability to predict intestinal ischemia

OBJECTIVES

Acute intestinal ischemia is a severe complication of abdominal aortic surgery that is difficult to diagnose early and therefore to treat adequately and timely. In this study the perioperative kinetics of d-lactate and ischemia-modified albumin (IMA) are described and the predictive value of these markers for the early diagnosis of acute intestinal ischemia is assessed.

DESIGN & METHODS

This non-randomised, single-centre cohort study enrolled 50 patients with abdominal aortic aneurysm (AAA) and 30 patients with aortoiliac occlusive disease (AOID). Serum d-lactate and IMA were assessed pre-, intra-, and postoperatively at eight defined time points.

RESULTS

The highest serum d-lactate was at 6 h after complete declamping of the vascular graft. The highest predictive power of d-lactate was at 3 h after complete declamping (AUC 0.857). IMA was found to be higher in the AAA group in ischemic patients 10 min after complete declamping than in the AOID group. The highest predictive values of IMA were at 1 h after aortic cross-clamping (AUC 0.758) and 3 and 6 h after complete declamping (0.745 and 0.721, respectively). Moreover, the multivariate model with both markers at 3 h after complete declamping improved the detection of intestinal ischemia (AUC 0.894).

CONCLUSIONS

Serum levels of IMA and d-lactate seem to be influential predictive markers for postoperative intestinal ischemia, especially after 3 h from complete declamping of vascular reconstruction.

Review article: Acute superior mesenteric vessel ischaemia: A review of clinical practice and biomarkers

A patient with acute occlusion of the superior mesenteric vessels resulting in superior mesenteric vessel ischaemia (SMVI) who presents to the ED with abdominal pain and unremarkable abdominal examination risks delay in diagnosis and treatment with adverse outcome. A comprehensive literature search was performed, and the evidence was reviewed. To-date, there are no accurate biomarkers of SMVI and so, heightened awareness among ED staff and rapidly actioning diagnostic imaging and surgical referral will help fast-track the patient with SMVI to surgical management. Management of SMVI is challenging and requires ongoing communication. Prompt surgical intervention may help reduce mortality and morbidity in SMVI. SMVI is associated with significant mortality and morbidity. With the lack of accurate biomarkers, diagnosis and management is challenging and requires heightened awareness among ED staff for prompt surgical referral and intervention.

Anaesthesia for vascular emergencies - a state of the art review

In this state-of-the-art review, we discuss the presenting symptoms and management strategies for vascular emergencies. Although vascular emergencies are best treated at a vascular surgical centre, patients may present to any emergency department and may require both immediate management and safe transport to a vascular centre. We describe the surgical and anaesthetic considerations for management of aortic dissection, aortic rupture, carotid endarterectomy, acute limb ischaemia and mesenteric ischaemia. Important issues to consider in aortic dissection are extent of the dissection and surgical need for bypasses in addition to endovascular repair. From an anaesthetist's perspective, aortic dissection requires infrastructure for massive transfusion, smooth management should an endovascular procedure require conversion to an open procedure, haemodynamic manipulation during stent deployment and prevention of spinal cord ischaemia. Principles in management of aortic rupture, whether open or endovascular treatment is chosen, include immediate transfer to a vascular care centre; minimising haemodynamic changes to reduce aortic shear stress; permissive hypotension in the pre-operative period; and initiation of massive transfusion protocol. Carotid endarterectomy for carotid stenosis is managed with general or regional techniques, and anaesthetists must be prepared to manage haemodynamic, neurological and airway issues peri-operatively. Acute limb ischaemia is a result of embolism, thrombosis, dissection or trauma, and may be treated with open repair or embolectomy, under either general or local anaesthesia. Due to hypercoagulability, there may be higher numbers of acutely ischaemic limbs among patients with COVID-19, which is important to consider in the current pandemic. Mesenteric ischaemia is a rare vascular emergency, but it is challenging to diagnose and associated with high morbidity and mortality. Several peri-operative issues are common to all vascular emergencies: acute renal injury; management of transfusion; need for heparinisation and reversal; and challenging postoperative care. Finally, the important development of endovascular techniques for repair in many vascular emergencies has improved care, and the availability of transoesophageal echocardiography has improved monitoring as well as aids in surgical placement of endovascular grafts and for post-procedural evaluation.

Imaging of Bowel Ischemia: An Update, From the AJR Special Series on Emergency Radiology

Acute mesenteric ischemia is a life-threatening condition that results from abrupt reduction in or cessation of blood flow to the bowel. Characterized by nonspecific abdominal symptoms, mesenteric ischemia is infrequently encountered and commonly misdiagnosed, with potentially catastrophic consequences. Prompt clinical diagnosis and early implementation of therapeutic interventions are critical to improving patient outcomes. Because cross-sectional imaging plays a key role in the diagnosis of mesenteric ischemia, radiologists must be familiar with the varied imaging manifestations of intestinal ischemia. Thus, the objectives of this article are to review the various types and common causes of mesenteric ischemia and to describe its spectrum of multimodality imaging findings, with special attention to novel imaging techniques and emerging diagnoses.

Intra-Arterial Urokinase for Acute Superior Mesenteric Artery Occlusion: A Retrospective 12-Year Report of 13 Cases

This retrospective study aimed to evaluate the outcomes of 13 patients with acute superior mesenteric artery (SMA) occlusion who underwent intra-arterial urokinase thrombolysis between 2008 and 2020. On angiography, seven presented with complete SMA occlusion versus six with incomplete occlusion. The median time from abdominal pain to attempting urokinase thrombolysis was 15.0 h (interquartile range, 6.0 h). After urokinase therapy, bowel perfusion was restored with bowel preservation in six patients; however, treatment failed in the other seven patients. The degree of SMA occlusion (complete vs. incomplete, p = 0.002), degree of recanalisation (p = 0.012), and length of stay (p = 0.032) differed significantly between groups. Of the seven patients with complete SMA occlusion, six underwent bowel resection, of whom three died, and the remaining patient died of shock due to delayed surgery. Among the six patients with incomplete SMA occlusion, no bowel resection was performed. In our experience, intra-arterial urokinase thrombolysis may serve as an adjunctive treatment modality, being a potential replacement for open thrombectomy that is able to preserve the bowel and obviate surgery in cases of incomplete SMA occlusion; however, its use is unsuitable in cases of complete SMA occlusion, for which surgery is warranted.

Hand-Sewn Versus Stapled Small Bowel Anastomoses in Patients With Secondary Mesenteric Ischemia

INTRODUCTION

Although stapled anastomoses have been widely evaluated in the context of the elective surgery, few reports compared manual with stapled anastomoses in patients undergoing emergency surgery. The aim of this study is to compare the outcome of hand-sewn end-to-end anastomoses with stapled side-to-side and stapled end-to-side anastomoses in patients undergoing small bowel resection for acute mesenteric ischemia secondary to intestinal obstruction.

METHODS

From January 2015 to June 2021 all the hemodynamically stable patients undergoing emergency surgery with small bowel resection for intestinal obstruction were enrolled in this study. According to surgical technique in performing anastomosis, the patients were divided into three groups: group 1: hand-sewn end-to-end anastomosis, group 2: stapled end-to-side anastomosis, and group 3: stapled side-to-side anastomosis.

RESULTS

Although the anastomosis failure rate was higher in group 3, it was not significantly different between the three groups (P = 0.78: chi-square test). Likewise, no significant differences in the median hospital stay were found between the patients' groups (P = 0.87: Kruskal-Wallis test). The median operating time was similar in patients undergoing stapled anastomoses and was significantly higher in patients undergoing hand-sewn anastomoses (P = 0.0009: Kruskal-Wallis test).

CONCLUSIONS

In patients undergoing emergency small bowel resection for complicated intestinal obstruction, a similar outcome in terms of dehiscence rate and hospital stay can be achieved performing stapled or hand-sewn anastomoses, even if restoring the intestinal continuity with stapled technique is associated with lower operating time.

[Computed tomography diagnostics of acute and chronic mesenteric ischemia]

BACKGRAUND

Chronic mesenteric ischemia is more often accompanied by clinical signs characteristic of colitis. Acute mesenteric ischemia, unlike chronic, is accompanied by nonspecific symptoms and is a serious disease that requires urgent diagnosis.

AIMS

The aim of the study was to evaluate the effectiveness of MSCT in the diagnosis of acute and chronic mesenteric ischemia based on our observations.

MATERIALS AND METHODS

The retrospective study included 135 patients with abdominalgia and suspected mesenteric ischemia who underwent multiphase CT of the abdominal cavity with intravenous bolus contrast enhancement. Group 1 included 105 patients with mesenteric ischemia; group 2 included 30, without confirmed mesenteric ischemia, with the presence of a symptom of mesenteric ischemia in the form of abdominalgia.

RESULTS

We studied 135 patients, including 105 patients with mesenteric ischemia, 59 women and 46 men of average age 60±14.9 years. The acute form of ischemia (58%) was determined 1.5 times more often than the chronic one. Occlusive and nonocclusive acute mesenteric ischemia occurred in equal proportions. Mesenteric arterial thrombosis was the cause of acute mesenteric ischemia in 23% of cases. Mesenteric venous thrombosis was the cause of chronic intestinal ischemia in 61%, in 5% - acute form. Mixed arterial-venous genesis of mesenteric ischemia was determined in 4% against the background of strangulation obstruction. Dunbar syndrome as a cause of chronic intestinal ischemia was diagnosed in 16%. Chronic ischemic enterocolitis accounted for 10% of all cases of mesenteric ischemia and 23% of chronic ischemia. Symptoms and symptom complexes characteristic of the studied series of diseases with acute or chronic mesenteric ischemia were delineated. Sensitivity, specificity and prognostic value of CT with intravenous bolus contrast enhancement in diagnostics of diseases accompanied by mesenteric ischemia reached 100%.

CONCLUSIONS

Multiphase CT of the abdominal cavity with bolus contrast enhancement is highly informative in the diagnosis of acute and chronic forms of mesenteric ischemia. Direct CT signs of impaired blood flow in the arteries or veins of the mesentery were indisputable. Indirect signs of mesenteric ischemia were aimed at a thorough analysis of the condition of mesenteric vessels.

Treatment of Acute Mesenteric Ischemia: Individual Challenges for Interventional Radiologists and Abdominal Surgeons

Background: Acute mesenteric ischemia (AMI) is a life-threatening condition resulting from occlusion of the mesenteric arterial vessels. AMI requires immediate treatment with revascularization of the occluded vessels. Purpose: to evaluate the technical success, clinical outcomes and survival of patients receiving endovascular treatment for AMI followed by surgery. Material and Methods: A search of our institution’s database for AMI revealed 149 potential patients between 08/2016 and 08/2021, of which 91 were excluded due to incomplete clinical data, insufficient imaging or missing follow-up laparoscopy. The final cohort included 58 consecutive patients [(median age 73.5 years [range: 43−96 years], 55% female), median BMI 26.2 kg/m2 (range:16.0−39.2 kg/m2)]. Periinterventional imaging regarding the cause of AMI (acute-embolic or acute-on-chronic) was evaluated by two radiologists in consensus. The extent of AMI and the degree of technical success was graded according to a modified TICI (Thrombolysis in Cerebral Infarction scale) score (TICI-AMI) classification (0: no perfusion; 1: minimal; 2a < 50% filling; 2b > 50%; 2c: near complete or slow; 3: complete). Lab data and clinical data were collected, including the results of follow-up laparoscopy. Non-parametric statistics were used. Results: All interventions were considered technically successful. The most common causes of AMI were emboli (51.7%) and acute-on-chronic thrombotic occlusions (37.9%). Initial imaging showed a TICI-AMI score of 0, 1 or 2a in 87.9% (n = 51) of patients. Post-therapeutic TICI-AMI scores improved significantly with 87.9% of patients grade 2b and better. Median lactate levels reduced from 2.7 (IQR 2.0−3.7) mg/dL (1−18) to 1.45 (IQR 0.99−1.90). Intestinal ischemia was documented in 79.1% of cases with resection of the infarcted intestinal loops. In total, 22/58 (37.9%) patients died during the first 30 days after intervention and surgery. According to CIRSE criteria, we did not observe any SAE scores of grade 2 or higher. Conclusions: AMI is a serious disease with high lethality within the first 30 days despite optimal treatment. However, interventional revascularization before surgery with resection of the infarcted bowel can save two out of three of critically ill patients.

Reperfusion injury on computed tomography following endovascular revascularization of acute mesenteric ischemia: prevalence, risk factors, and patient outcome

BACKGROUND

Data about reperfusion injury (RI) following acute arterial mesenteric ischemia (AAMI) in humans are scarce. We aimed to assess the prevalence and risk factors of RI following endovascular revascularization of AMI and evaluate its impact on patient outcomes.

METHODS

Patients with AAMI who underwent endovascular revascularization (2016-2021) were included in this retrospective cohort. CT performed < 7 days after treatment was reviewed to identify features of RI (bowel wall hypoattenuation, mucosal hyperenhancement). Clinical, laboratory, imaging, and treatments were compared between RI and non-RI patients to identify factors associated with RI. Resection rate and survival were also compared.

RESULTS

Fifty patients (23 men, median 72-yrs [IQR 60-77]) were included, and 22 were diagnosed with RI (44%) after a median 28 h (22-48). Bowel wall hypoattenuation and mucosal hyperenhancement were found in 95% and 91% of patients with post-interventional RI, respectively. Patients with RI had a greater increase of CRP levels after endovascular treatment (p = 0.01). On multivariate analysis, a decreased bowel wall enhancement on baseline CT (HR = 8.2), an embolic cause (HR = 7.4), complete SMA occlusion (HR = 7.0), and higher serum lactate levels (HR = 1.4) were associated with RI. The three-month survival rate was 78%, with no difference between subgroups (p = 0.99). However, the resection rate was higher in patients with RI (32% versus 7%; p = 0.03).

CONCLUSION

RI is frequent after endovascular revascularization of AAMI, especially in patients who present with decreased bowel wall enhancement on pre-treatment CT, an embolic cause, and a complete occlusion of the SMA. However, its occurrence does not seem to negatively impact short-term survival.

Understanding CT imaging findings based on the underlying pathophysiology in patients with small bowel ischemia

Because acute small bowel ischemia has a high mortality rate, it requires rapid intervention to avoid unfavorable outcomes. Computed tomography (CT) examination is important for the diagnosis of bowel ischemia. Acute small bowel ischemia can be the result of small bowel obstruction or mesenteric ischemia, including mesenteric arterial occlusion, mesenteric venous thrombosis, and non-occlusive mesenteric ischemia. The clinical significance of each CT finding is unique and depends on the underlying pathophysiology. This review describes the definition and mechanism(s) of bowel ischemia, reviews CT findings suggesting bowel ischemia, details factors involved in the development of small bowel ischemia, and presents CT findings with respect to the different factors based on the underlying pathophysiology. Such knowledge is needed for accurate treatment decisions.

Basic demographic characteristics and prevalence of comorbidities in acute mesenteric ischemia: a systematic review and proportional meta-analysis

PURPOSE

The aim of this systematic review and meta-analysis was to examine and assess the basic demographic characteristics and prevalence of comorbidities in acute mesenteric ischemia (AMI) and its various subtypes.

PATIENTS AND METHODS

A literature search was conducted by using the databases PubMed, EMBASE, and Google Scholar (to June 1, 2022). Random-effects or fixed-effects models were selected to pool means and proportions and their corresponding 95% confidence intervals (CI), based on heterogeneity between studies. The results of meta-analyses for basic demographic characteristics and prevalence (proportions) of each specific comorbidities of acute mesenteric ischemia (AMI) and its various subtypes were described.

RESULTS

Ninety-nine studies were included in the meta-analysis, including 17,103 patients with AMI. Furthermore, 7941 patients with subclass diagnoses of AMI were identified, including 3,239 patients with arterial occlusive mesenteric ischemia (AOMI), 2,977 patients with nonocclusive mesenteric ischemia (NOMI), and 1,725 patients with mesenteric venous thrombosis (MVT). As a surgical emergency, AMI is associated with older patients and a high likelihood of multisystem comorbidities. Comorbidities of AMI involved multiple systemic diseases, including cardiovascular disease, endocrine and metabolic diseases, kidney diseases, digestive diseases, respiratory diseases, cerebrovascular diseases, vascular diseases, and cancer.

CONCLUSION

The basic demographic characteristics and the prevalence of comorbidities of different subtypes of AMI are different. The management of comorbidities should be an essential part of improving the prognosis of AMI patients and may contribute to precise prevention of AMI.

Acute mesenteric ischaemia

PURPOSE OF REVIEW

To summarize the recent evidence on acute mesenteric ischaemia (AMI).

RECENT FINDINGS

The overall incidence of AMI is below 10/100 000 person years but increases exponentially with age. The overall mortality of AMI remains high, exceeding 50%, despite continuing progress and increasing availability of imaging and endovascular interventions. However, patients with (early) revascularization have significantly better outcomes. The majority of patients surviving the acute event are still alive at 1 year, but evidence on quality of life is scarce.Clinical suspicion of AMI is the key to timely diagnosis, with biphasic computed tomography-angiography the diagnostic method of choice. Currently, no biomarker has sufficient specificity to diagnose AMI.

SUMMARY

Improved awareness and knowledge of AMI are needed to raise the suspicion of AMI in relevant patients and thereby to achieve better outcomes.

Superior Mesenteric Artery Occlusion Caused by Infective Endocarditis and Worsened by Mycotic Aneurysm and Intracranial Hemorrhage: A Case Report

The superior mesenteric artery (SMA) is more commonly occluded than other abdominal arteries due to anatomical factors. Though rare, SMA occlusion is life-threatening. We present the case of a 50-year-old male patient who presented with fever and abdominal pain and was subsequently diagnosed with SMA embolism, SMA mycotic aneurysm, and infective endocarditis. Many patients visit the emergency room complaining of abdominal pain. Although SMA occlusion diagnosis is rare in these cases, detailed examination and close monitoring of patients are warranted considering the high mortality rate of this disease.

Unsupervised and quantitative intestinal ischemia detection using conditional adversarial network in multimodal optical imaging

Purpose

Intraoperative evaluation of bowel perfusion is currently dependent upon subjective assessment. Thus, quantitative and objective methods of bowel viability in intestinal anastomosis are scarce. To address this clinical need, a conditional adversarial network is used to analyze the data from laser speckle contrast imaging (LSCI) paired with a visible-light camera to identify abnormal tissue perfusion regions.

Approach

Our vision platform was based on a dual-modality bench-top imaging system with red-green-blue (RGB) and dye-free LSCI channels. Swine model studies were conducted to collect data on bowel mesenteric vascular structures with normal/abnormal microvascular perfusion to construct the control or experimental group. Subsequently, a deep-learning model based on a conditional generative adversarial network (cGAN) was utilized to perform dual-modality image alignment and learn the distribution of normal datasets for training. Thereafter, abnormal datasets were fed into the predictive model for testing. Ischemic bowel regions could be detected by monitoring the erroneous reconstruction from the latent space. The main advantage is that it is unsupervised and does not require subjective manual annotations. Compared with the conventional qualitative LSCI technique, it provides well-defined segmentation results for different levels of ischemia.

Results

We demonstrated that our model could accurately segment the ischemic intestine images, with a Dice coefficient and accuracy of 90.77% and 93.06%, respectively, in 2560 RGB/LSCI image pairs. The ground truth was labeled by multiple and independent estimations, combining the surgeons' annotations with fastest gradient descent in suspicious areas of vascular images. The total processing time was 0.05 s for an image size of 256 × 256 .

Conclusions

The proposed cGAN can provide pixel-wise and dye-free quantitative analysis of intestinal perfusion, which is an ideal supplement to the traditional LSCI technique. It has potential to help surgeons increase the accuracy of intraoperative diagnosis and improve clinical outcomes of mesenteric ischemia and other gastrointestinal surgeries.

ACR Appropriateness Criteria® Radiologic Management of Mesenteric Ischemia: 2022 Update

Mesenteric ischemia is a serious medical condition characterized by insufficient vascular supply to the small bowel. In the acute setting, endovascular interventions, including embolectomy, transcatheter thrombolysis, and angioplasty with or without stent placement, are recommended as initial therapeutic options. For nonocclusive mesenteric ischemia, transarterial infusion of vasodilators, such as papaverine or prostaglandin E1, is the recommended initial treatment. In the chronic setting, endovascular means of revascularization, including angioplasty and stent placement, are generally recommend, with surgical options, such as bypass or endarterectomy, considered alternative options. Although the diagnosis of median arcuate ligament syndrome remains controversial, diagnostic angiography can be helpful in rendering a diagnosis, with the preferred treatment option being a surgical release. Systemic anticoagulation is recommended as initial therapy for venous mesenteric ischemia with acceptable rates of recanalization. If anticoagulation fails, transcatheter thrombolytic infusion can be considered with possible adjunctive placement of a transjugular intrahepatic portosystemic shunt to augment antegrade flow. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Visible near-infrared hyperspectral imaging and supervised classification for the detection of small intestinal necrosis tissue in vivo

Complete recognition of necrotic areas during small bowel tissue resection remains challenging due to the lack of optimal intraoperative aid identification techniques. This research utilizes hyperspectral imaging techniques to automatically distinguish normal and necrotic areas of small intestinal tissue. Sample data were obtained from the animal model of small intestinal tissue of eight Japanese large-eared white rabbits developed by experienced physicians. A spectral library of normal and necrotic regions of small intestinal tissue was created and processed using six different supervised classification algorithms. The results show that hyperspectral imaging combined with supervised classification algorithms can be a suitable technique to automatically distinguish between normal and necrotic areas of small intestinal tissue. This new technique could aid physicians in objectively identify normal and necrotic areas of small intestinal tissue.

Prognostic factors in patients with acute mesenteric ischemia-novel tools for determining patient outcomes

BACKGROUND

Acute mesenteric ischemia (AMI) is a devastating disease with poor prognosis. Due to the multitude of underlying factors, prediction of outcomes remains poor. We aimed to identify factors governing diagnosis and survival in AMI and develop novel prognostic tools.

METHODS

This monocentric retrospective study analyzed patients with suspected AMI undergoing imaging between January 2014 and December 2019. Subgroup analyses were performed for patients with confirmed AMI undergoing surgery. Nomograms were calculated based on multivariable logistic regression models.

RESULTS

Five hundred and thirty-nine patients underwent imaging for clinically suspected AMI, with 216 examinations showing radiological indication of AMI. Intestinal necrosis (IN) was confirmed in 125 undergoing surgery, 58 of which survived and 67 died (median 9 days after diagnosis, IQR 22). Increasing age, ASA score, pneumatosis intestinalis, and dilated bowel loops were significantly associated with presence of IN upon radiological suspicion. In contrast, decreased pH, elevated creatinine, radiological atherosclerosis, vascular occlusion (versus non-occlusive AMI), and colonic affection (compared to small bowel ischemia only) were associated with impaired survival in patients undergoing surgery. Based on the identified factors, we developed two nomograms to aid in prediction of IN upon radiological suspicion (C-Index = 0.726) and survival in patients undergoing surgery for IN (C-Index = 0.791).

CONCLUSION

As AMI remains a condition with high mortality, we identified factors predicting occurrence of IN with suspected AMI and survival when undergoing surgery for IN. We provide two new tools, which combine these parameters and might prove helpful in treatment of patients with AMI.

Incidence and outcomes of acute mesenteric ischaemia: a systematic review and meta-analysis

OBJECTIVE

To estimate the incidence of acute mesenteric ischaemia (AMI), proportions of its different forms and short-term and long-term mortality.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

MEDLINE (Ovid), Web of Science, Scopus and Cochrane Library were searched until 26 July 2022.

ELIGIBILITY CRITERIA

Studies reporting data on the incidence and outcomes of AMI in adult populations.

DATA EXTRACTION AND SYNTHESIS

Data extraction and quality assessment with modified Newcastle-Ottawa scale were performed using predeveloped standard forms. The outcomes were the incidence of AMI and its different forms in the general population and in patients admitted to hospital, and the mortality of AMI in its different forms.

RESULTS

From 3064 records, 335 full texts were reviewed and 163 included in the quantitative analysis. The mean incidence of AMI was 6.2 (95% CI 1.9 to 12.9) per 100 000 person years. On average 5.0 (95% CI 3.3 to 7.1) of 10 000 hospital admissions were due to AMI. Occlusive arterial AMI was the most common form constituting 68.6% (95% CI 63.7 to 73.2) of all AMI cases, with similar proportions of embolism and thrombosis.Overall short-term mortality (in-hospital or within 30 days) of AMI was 59.6% (95% CI 55.5 to 63.6), being 68.7% (95% CI 60.8 to 74.9) in patients treated before the year 2000 and 55.0% (95% CI 45.5 to 64.1) in patients treated from 2000 onwards (p<0.05). The mid/long-term mortality of AMI was 68.2% (95% CI 60.7 to 74.9). Mortality due to mesenteric venous thrombosis was 24.6% (95% CI 17.0 to 32.9) and of non-occlusive mesenteric ischaemia 58.4% (95% CI 48.6 to 67.7). The short-term mortality of revascularised occlusive arterial AMI was 33.9% (95% CI 30.7 to 37.4).

CONCLUSIONS

In adult patients, AMI is a rarely diagnosed condition with high mortality, although with improvement of treatment results over the last decades. Two thirds of AMI cases are of occlusive arterial origin with potential for better survival if revascularised.

PROSPERO REGISTRATION NUMBER

CRD42021247148.

Morbidity and Mortality of Neutropenic Patients in Visceral Surgery: A Narrative Review

Leukocytes are essential for the function of the immune system and cell–cell interaction in the human body, but hematological diseases as well as chemotherapeutic treatments due to cancer lead to occasionally or even permanent leukocyte deficiency. Normally, more than 50% of leukocytes are neutrophilic granulocytes, and leukopenia is, therefore, mostly characterized by a decrease in neutrophilic granulocytes. The consequence of neutropenia is increased susceptibility to infection, but also healing disorders are suggestable due to the disturbed cell–cell interaction. While there is no surgical treatment for leucocyte disorders, patients suffering from neutropenia are sometimes in need of surgery for other reasons. Less is known about the morbidity and mortality of this patients, which is why this narrative review critically summarizes the results of recent research in this particular field. The results of this review suggest that neutropenic patients in need of emergency surgery have a higher mortality risk compared to non-neutropenic patients. In contrast, in elective surgery, there was not a clear tendency for a higher mortality risk of neutropenic patients. The role of neutrophilic granulocytes in inflammation and immunity in surgical patients is emphasized by the results, but most of the evaluated studies showed methodological flaws due to small sample sizes or risk of bias. Further research has to evaluate the risk for postoperative complications, particularly of infectious complications such as surgical site infections, in neutropenic patients undergoing elective surgery, and should address the role of neutrophilic function in postoperative morbidity and mortality.