The importance of open emergency surgery in the treatment of acute mesenteric ischemia

NIR-II AIEgen nanocomplex with suppressed nonradiative decay and intersystem crossing for high-contrast mesenteric vascular imaging

The prompt assessment of the mesenteric vasculature is crucial for the diagnosis of lethal mesenteric ischemia, underscoring the need for real-time mesenteric vascular imaging using small organic molecules that radiate fluorescence within the second near-infrared spectrum (NIR-II) due to its deep penetration and elevated signal-to-background ratio (SBR), which have been rarely reported. Unfortunately, numerous NIR-II dyes exhibit low quantum yields (QYs) when employed in practical applications, highlighting the need for QY enhancement. For this research, a NIR-II fluorescent AIEgen, termed TPETPA-TQT, was rationally designed by incorporating tetraphenylethylene (TPE)-fused triphenylamine (TPA) into the robust, high QY core of 6,7-di(thiophen-2-yl)-[1,2,5]thiadiazolo[3,4-g]quinoxaline (TQT). We further encapsulated this dye within F127 to form the TPETPA-TQT F127 nanocomplex, which exhibits a 6.5-fold enhancement in fluorescence intensity over the TPA-TQT dye encapsulated with DSPE-PEG2000, attributed to the suppression of molecular nonradiative decay and intersystem crossing. The abdominal vasculature and microvessels on the intestinal wall surface, as narrow as 0.41 mm, can real-time visualization using TPETPA-TQT F127 nanocomplex, and exhibit a 94 % improvement of SBR versus ICG. Our findings will push forward the progress of high-brightness NIR-II contrast agents for enhanced mesenteric vasculature imaging and mesenteric ischemia diagnosis.

Acute mesenteric ischemia diagnosed via computed tomography in a dog following vehicular blunt force trauma: a Case Report

Acute mesenteric ischemia (AMI) refers to a group of vascular disorders that disrupt intestinal blood flow, resulting in intestinal ischemia and necrosis if left untreated. In both humans and dogs, this condition appears to be rare but deadly. There has only been one documented case of traumatic acute mesenteric ischemia in a dog, and the diagnosis was conducted through laparotomy. We present the case of a dog that was struck by a vehicle and subsequently developed traumatic acute mesenteric ischemia, which was diagnosed through computed tomography (CT). The dog presented with profuse hemorrhagic diarrhea, which persisted throughout the hospitalization. The dog's condition eventually deteriorated as a result of diffuse intestinal ischemia, diagnosed using computed tomography (CT). Due to the anticipated poor prognosis, the dog was euthanized humanely. Traumatic acute mesenteric ischemia in dogs may be an underdiagnosed consequence of vehicular trauma, necessitating further diagnostic investigation in dogs with persistent gastrointestinal signs that are unresponsive to medical therapy.

Endovascular revascularization vs open surgical revascularization as the first strategy for arterial acute mesenteric ischemia: A systematic review and meta-analysis

OBJECTIVE

This paired meta-analysis aimed to compare the mortality and morbidity of endovascular revascularization (EVR) and open surgical revascularization (OSR) as the first strategy for arterial acute mesenteric ischemia (AMI).

METHODS

This systematic review and meta-analysis were performed in accordance with the PRISMA statement. A systematic search strategy was performed to identify eligible studies using the following databases: PubMed, Embase, and Cochrane Library database from inception to December 31, 2023, with restriction to the English language. The end search date was January 2, 2024. The primary outcome was short-term mortality. Secondary outcomes included bowel resection, second-look laparotomy, and short bowel syndrome. The counterenhanced funnel plot and the Peters' test were used to assess bias. Outcomes were reported as odds ratio (OR) with a 95% confidence interval (CI) using the Mantel-Haenszel method. The GRADE classification was used to estimate the certainty of evidence.

RESULTS

A total of 11 studies (1141 patients) comparing EVR vs OSR for arterial AMI were identified and analyzed. The mean patient age was 61.9 to 73.6 years and 45.1% of the patients were male. Compared with OSR, EVR as the first treatment may not decrease short-term mortality (OR, 0.79; 95% CI, 0.50-1.25; P = .31; very low certainty) and second-look laparotomy (OR, 1.00; 95% CI, 0.30-3.36; P = .99; very low certainty). However, EVR may be associated with decreased bowel resection (OR, 0.42; 95% CI, 0.20-0.88; P = .022; very low certainty) and short bowel syndrome (OR, 0.39; 95% CI, 0.21-0.75; P = .005; very low certainty). The metaregression revealed that the mortality regarding EVR vs OSR was not impacted significantly by thrombotic etiology (-0.002; 95% CI, -0.027 to 0.022; P = .85), whereas it was impacted significantly by publication year (0.076; 95% CI, 0.069-0.145; P = .031).

CONCLUSIONS

Compared with OSR, EVR as the first treatment for arterial AMI may not decrease short-term mortality or second-look laparotomy. Future multicenter randomized controlled trials are needed urgently to confirm these results.

Association between periodic variation of air temperature, humidity, atmospheric pressure and hospital admissions for acute occlusive mesenteric ischaemia

Referring to the intestinal ischemic injury caused by sudden interruption of the blood supply, acute mesenteric ischemia (AMI) is a highly fatal emergency with mortality rates varying from 58 to 80%. The aim of this study was to explore the effect of temperature on AMI admission. This was a retrospective, multicentric study. The medical records of 1477 patients with verified AMI who were consecutively admitted to 3 hospitals anytime between January 2010 and December 2020 were included in the study. Distributed lag non-linear model was applied, the model was adjusted for temperature, atmospheric pressure, relative humidity, year, holiday, day of the week, time and seasonality. AMI exhibited obvious sex preference, AMI patients tended to be male (M/F ratio = 2.3:1) and in their late 50 s. Hospital admissions of acute mesenteric arterial thromboembolism (AMAT) increased significantly with high temperatures on day of exposure and lag 0-14 day. The effect curve of daily average temperature on acute mesenteric venous thromboembolism (AMVT) admission was J-shaped, and the duration of cold effect was longer, while the duration of heat effect was shorter. An increase in hospital admissions of AMVT was found above 20 °C at lag 0-30. For the first time, our study indicated that temperature is significantly associated with the risk of AMI. Although it is not possible to always avoid exposure to extreme temperatures, one should be aware of dramatic temperature fluctuations and take appropriate precautions.

Acute mesenteric ischemia due to superior mesenteric artery thrombosis in a patient with protein S deficiency: A case report

INTRODUCTION

Protein S deficiency resulting in mesenteric vein thrombosis has been reported in previous studies however those causing SMA thrombosis has been rarely reported. Multidisciplinary approach involving general surgeon, a vascular surgeon, an interventional radiologist, and an intensivist are crucial for management of SMA thrombosis.

CASE PRESENTATION

A 39-year-old non-smoker hypertensive female who was diagnosed with partially occlusive thrombus in the superior mesenteric artery via Contrast-enhanced computed tomography (CECT) re-presented after 5 days and CECT revealed a partially occlusive thrombus in the superior mesenteric artery and Protein S deficiency (free protein S:15 %). She was managed by lysis of thrombus with streptokinase by interventional radiology team. The patient is on anticoagulants and without abdominal complaints on follow-up at 24 months.

DISCUSSION

Computed tomography angiography should be done immediately in any patient suspected of AMI since delay in diagnosis accounts for high mortality rates of 30-70 %. The surgical treatment of the condition is well established and consists of revascularization and/or resection of nonviable bowel. Endovascular techniques have emerged as an alternative for occlusion of the SMA. Patients with protein C and/or S deficiency treated for AMI require lifelong anticoagulant/antiplatelet therapy to prevent relapse.

CONCLUSION

Hereditary thrombophilia should be suspected in young people with unusual thrombotic presentations. Earlier diagnosis and aggressive antithrombotic therapy in individuals with hypercoagulable states can improve outcomes. Treatment involving a multidisciplinary approach improves outcomes.

Establishment of an acute arterial mesenteric ischaemia model in canines with an endovascular approach

Purpose

This study aimed to evaluate the feasibility of establishing an arterial acute mesenteric ischemia (AMI) model in canines using transcatheter autologous thrombus administration.

Materials and methods

Ten canines were divided into the experimental group (Group A, n = 5) and the sham group (Group B, n = 5). The canines in Group A received thrombus administration to the superior mesenteric artery (SMA) through a guiding catheter, while the canines in Group B received normal saline administration. Blood samples were collected and tested at baseline and 2 h after modelling. Canines in Group A underwent manual thromboaspiration after blood and intestine samples were collected. Ischaemic grades of intestinal mucosa were evaluated under light microscopes.

Results

The AMI models were successfully conducted in all canines without procedure-related vessel injury or death. At the 2-h follow-up, the high-sensitivity C-reactive protein and D-dimer in Group A were significantly higher than in Group B (5.72 ± 1.8 mg/L vs. 2.82 ± 1.5 mg/L, p = 0.024; 2.25 ± 0.8 μg/mL vs. 0.27 ± 0.10 μg/mL, p = 0.005; respectively). The mean histopathologic intestinal ischaemic grade in Group A was significantly higher than in Group B (2.4 ± 0.5 vs. 0.8 ± 0.4, p < 0.001). After a median of 2 times of thromboaspiration, 80% (4/5) of the canines achieved complete SMA revascularisation.

Conclusion

This experimental study demonstrated that establishing an arterial model in canines using endovascular approaches was feasible. The present model may play an important role in the investigation of endovascular techniques in the treatment of arterial AMI.

Utility of indocyanine green fluorescent dye in emergency general surgery: a review of the contemporary literature

For decades, indocyanine green (ICG) has been available for medical and surgical use. The indications for ICG use in surgery have expanded where guided surgery directed by fluorescence and near-infrared fluorescent imaging offers numerous advantages. Recently, surgeons have reported using ICG operative navigation in the emergency setting, with fluorescent cholangiography being the most common procedure. The utility of ICG also involves real-time perfusion assessment, such as ischemic organs and limbs. The rising use of ICG in surgery can be explained by the ICG's rapid technological evolution, accuracy, ease of use, and great potential to guide precision surgical diagnosis and management. The review aims to summarize the current literature on the uses of ICG in emergency general surgery. It provides a comprehensive and practical summary of the use of ICG, including indication, route of administration, and dosages. To simplify the application of ICG, we subdivided its use into anatomical mapping and perfusion assessment. Anatomical mapping includes the biliary tree, ureters, and bowel. Perfusion assessment includes bowel, pancreas, skin and soft tissue, and gonads. This review provides a reference to emergency general surgeons to aid in implementing ICG in the emergency setting for more enhanced and safer patient care.

Diagnostic potential of plasma biomarkers and exhaled volatile organic compounds in predicting the different stages of acute mesenteric ischaemia: protocol for a multicentre prospective observational study (TACTIC study)

INTRODUCTION

Acute mesenteric ischaemia (AMI) is a life-threatening condition with short-term mortality of up to 80%. The diagnosis of AMI has remained troublesome due to the non-specific clinical presentation, symptoms and laboratory findings. Early unambiguous diagnosis of AMI is critical to prevent progression from reversible to irreversible transmural intestinal damage, thereby decreasing morbidity and improving survival. The present study aims to validate a panel of plasma biomarkers and investigate volatile organic compound (VOC) profiles in exhaled air as a tool to timely and accurately diagnose AMI.

METHODS AND ANALYSIS

In this international multicentre prospective observational study, 120 patients (>18 years of age) will be recruited with clinical suspicion of AMI. Clinical suspicion is based on: (1) clinical manifestation, (2) physical examination, (3) laboratory measurements and (4) the physician's consideration to perform a CT scan. The patient's characteristics, repetitive blood samples and exhaled air will be prospectively collected. Plasma levels of mucosal damage markers intestinal fatty acid-binding protein and villin-1, as well as transmural damage marker smooth muscle protein 22-alpha, will be assessed by ELISA. Analysis of VOCs in exhaled air will be performed by gas chromatography time-of-flight mass spectrometry. Diagnosis of AMI will be based on CT, endovascular and surgical reports, clinical findings, and (if applicable) verified by histopathological examination.

ETHICS AND DISSEMINATION

The study protocol was approved by the Medical Research Ethics Committee (METC) of Maastricht University Medical Centre+ and Maastricht University (METC azM/UM), the Netherlands (METC19-010) and the Ethics Committee Research UZ/KU Leuven, Belgium (S63500). Executive boards and local METCs of other Dutch participating centres Gelre Ziekenhuizen (Apeldoorn), Medisch Spectrum Twente (Enschede), and University Medical Centre Groningen have granted permission to carry out this study. Study results will be disseminated via open-access peer-reviewed scientific journals and national/international conferences.

TRIAL REGISTRATION NUMBER

NCT05194527.

Current Approaches for Mesenteric Ischemia and Visceral Aneurysms

This article provides an overview of acute mesenteric ischemia, chronic mesenteric ischemia, and visceral aneurysms, with a focus on treatment. Acute mesenteric ischemia can be a challenging diagnosis. Early recognition and adequate revascularization are key to patient outcomes. Chronic mesenteric ischemia is a more insidious process, typically caused by atherosclerosis. Various options for revascularization exist, which must be tailored to each patient. Visceral aneurysms are rare and the natural history is not well defined. However, given the risk of rupture and high mortality, treatment may be complex.

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.

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.

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.

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.

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.

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

Acute mesenteric ischemia (AMI) is a group of diseases characterized by an interruption of the blood supply to varying portions of the intestine, leading to ischemia and secondary inflammatory changes. If untreated, this process may progress to life-threatening intestinal necrosis. The incidence is low, estimated at 0.09-0.2% of all acute surgical admissions, but increases with age. Although the entity is an uncommon cause of abdominal pain, diligence is required because if untreated, mortality remains in the range of 50%. Early diagnosis and timely surgical intervention are the cornerstones of modern treatment to reduce the high mortality associated with this entity. The advent of endovascular approaches in parallel with modern imaging techniques is evolving and provides new treatment options. Lastly, a focused multidisciplinary approach based on early diagnosis and individualized treatment is essential. Thus, we believe that updated guidelines from World Society of Emergency Surgery are warranted, in order to provide the most recent and practical recommendations for diagnosis and treatment of AMI.

Outcomes of bowel resection following non-mechanical intestinal obstruction due to mesenteric vein thrombosis in Uganda: A case series

Introduction and importance

Mesenteric venous thrombosis (MVT) is one of the common occlusive causes of compromised bowel perfusion. Contrast-enhanced CT angiography is the diagnostic imaging study of choice for MVT. In-hospital mortality following acute mesenteric infarction is 63 %. Surgical resection may be life saving for patients with peritoneal signs or refractory to conservative management.

Case presentation

We consecutively included records of five patients from Lubaga Hospital with intestinal obstruction who underwent bowel resection following intraoperatively confirmed acute mesenteric ischemia between May 2017 and November 2021. Three of the patients were female. Patients were between 21 and 45 years. One patient had comorbid conditions and an identifiable underlying etiology of polycythemia for MVT. Duration of symptoms ranged from 1 to 11 days. All patients underwent open laparotomy, the length of bowel resection ranged from 77 cm to 600 cm (mean length of 337 cm). Two patients developed short bowel syndrome (SBS) and one patient developed intestinal fistula. There was one in-hospital death due to multi-organ failure.

Clinical discussion

Morbidity and mortality are associated with delay to diagnose the condition. Revascularization is the primary goal, resection of all non-viable regions and preservation of viable bowel. Mortality is commonly related to multi-organ failure. Advanced intensive care and parenteral nutrition have improved survival rates over the years. 2-year and 5-year survival rates have been reported to be 70 % and 50 %.

Conclusion

Good outcomes are still possible for post-operatively optimized patients despite the high mortality and morbidity associated with bowel resection following extensive mesenteric thrombosis.

•

Despite high morbidity and mortality of mesenteric thrombosis, good outcomes are possible in optimized patients.

•

Short bowel syndrome and fistulae are a major course of morbidity in massive bowel resected patients.

•

Surgery is indicated for patients with peritoneal signs and those refractory to conservative management.

Identifying survival protective factors for chronic dialysis patients with surgically confirmed acute mesenteric ischemia

BACKGROUND

Mesenteric ischemia is significantly more common in end-stage kidney disease patients undergoing chronic dialysis than in the general population and is associated with high morbidity and mortality. However, reports on prognostic factors in this population are limited.

AIM

To elucidate the in-hospital outcomes of acute mesenteric ischemia in chronic dialysis patients and to analyze protective factors for survival.

METHODS

The case data of 426 chronic dialysis patients who were hospitalized in a tertiary medical center for acute mesenteric ischemia over a 14-year period were retrospectively reviewed. Of these cases, 103 were surgically confirmed, and the patients were enrolled in this study. A Cox regression analysis was used to evaluate the protective factors for survival.

RESULTS

The in-hospital mortality rate among the 103 enrolled patients was 46.6%. Univariate analysis was performed to compare factors in survivors and nonsurvivors, with better in-hospital outcomes associated with a surgery delay (defined as the time from onset of signs and symptoms to operation) < 4.5 d, no shock, a higher potassium level on day 1 of hospitalization, no resection of the colon, and a total bowel resection length < 110 cm. After 1 wk of hospitalization, patients with lower white blood cell count and neutrophil counts, higher lymphocyte counts, and lower C-reactive protein levels had better in-hospital outcomes. Following multivariate adjustment, a higher potassium level on day 1 of hospitalization (HR 1.71, 95%CI 1.19 to 2.46; P = 0.004), a lower neutrophil count (HR 0.91, 95%CI 0.84 to 0.99; P = 0.037) at 1 wk after admission, resection not involving the colon (HR 2.70, 95%CI 1.05 to 7.14; P = 0.039), and a total bowel resection length < 110 cm (HR 4.55, 95%CI 1.43 to 14.29; P = 0.010) were significantly associated with survival.

CONCLUSION

A surgery delay < 4.5 d, no shock, no resection of the colon, and a total bowel resection length < 110 cm predicted better outcomes in chronic dialysis patients with acute mesenteric ischemia.

Vasopressors and Risk of Acute Mesenteric Ischemia: A Worldwide Pharmacovigilance Analysis and Comprehensive Literature Review

Vasodilatory shock, such as septic shock, requires personalized management which include adequate fluid therapy and vasopressor treatments. While these potent drugs are numerous, they all aim to counterbalance the vasodilatory effects of a systemic inflammatory response syndrome. Their specific receptors include α- and β-adrenergic receptors, arginine-vasopressin receptors, angiotensin II receptors and dopamine receptors. Consequently, these may be associated with severe adverse effects, including acute mesenteric ischemia (AMI). As the risk of AMI depends on drug class, we aimed to review the evidence of plausible associations by performing a worldwide pharmacovigilance analysis based on the World Health Organization database, VigiBase®. Among 24 million reports, 104 AMI events were reported, and disproportionality analyses yielded significant association with all vasopressors, to the exception of selepressin. Furthermore, in a comprehensive literature review, we detailed mechanistic phenomena which may enhance vasopressor selection, in the course of treating vasodilatory shock.

A Shifting Trend Towards Endovascular Intervention in the Treatment of Acute Mesenteric Ischemia

Background

Acute mesenteric ischemia (AMI) is a vascular emergency with a quite low incidence, but it is associated with disproportionately more severe morbidity and mortality. The aim of this study was to assess the current trend in the treatment of AMI and to see if endovascular intervention is an effective treatment modality in the selected group of patients.

Methods

A retrospective review of patients admitted with AMI between 2007 and 2018 was performed. Outcome measures were length of stay (LOS) at hospital and intensive care unit (ICU), and post-treatment mortality.

Results

A total of 98 patients with AMI were admitted during the study period. Patients undergoing endovascular treatment compared with surgery were younger (62.9 ± 13.7 years vs. 69.5 ± 12.8 years; p = 0.01). Shorter LOS in hospital and ICU was observed for those treated with endovascular approach (6.8 ± 3.4 and 3.25 ± 0.5 days) compared to the surgical group (25 ± 8.6 and 12.8 ± 26.8 days; p < 0.001). Out of 39 patients requiring ICU admission, 48.7% were surgically treated and 10.2% underwent endovascular intervention (p < 0.001). Mortality associated with surgery was 30.6% compared to only 6.6% with endovascular intervention (p < 0.001). Between 2007 and 2012, only one patient underwent endovascular intervention and 20 underwent surgery compared to 14 patients treated with endovascular approach and 16 with surgery between 2013 and 2018.

Conclusion

In this non-randomized, retrospective case series, patients with endovascular treatment fared clinically better and the intervention was found to be safe and feasible in the selected group of patients. We suggest a preference for this modality where possible. At our hospital, a trend favoring this approach is apparent during the last six years.

Maintaining oxygen delivery is crucial to prevent intestinal ischemia in critical ill patients

BACKGROUND

Intestinal ischemia is a common complication with obscure pathophysiology in critically ill patients. Since insufficient delivery of oxygen is discussed, we investigated the influence of oxygen delivery, hemoglobin, arterial oxygen saturation, cardiac index and the systemic vascular resistance index on the development of intestinal ischemia. Furthermore, we evaluated the predictive power of elevated lactate levels for the diagnosis of intestinal ischemia.

METHODS

In a retrospective case-control study data (mean oxygen delivery, minimum oxygen delivery, systemic vascular resistance index) of critical ill patients from 02/2009-07/2017 were analyzed using a proportional hazard model. General model fit and linearity were tested by likelihood ratio tests. The components of oxygen delivery (hemoglobin, arterial oxygen saturation and cardiac index) were individually tested in models.

RESULTS

59 out of 874 patients developed intestinal ischemia. A mean oxygen delivery less than 250ml/min/m2 (LRT vs. null model: p = 0.018; LRT for non-linearity: p = 0.012) as well as a minimum oxygen delivery less than 400ml/min/m2 (LRT vs null model: p = 0.016; LRT for linearity: p = 0.019) were associated with increased risk of the development of intestinal ischemia. We found no significant influence of hemoglobin, arterial oxygen saturation, cardiac index or systemic vascular resistance index. Receiver operating characteristics analysis for elevated lactate levels, pH, CO2 and central venous saturation was poor with an area under the receiver operating characteristic of 0.5324, 0.52, 0.6017 and 0.6786.

CONCLUSION

There was a significant correlation for mean and minimum oxygen delivery with the incidence of intestinal ischemia for values below 250ml/min/m2 respectively 400ml/min/m2. Neither hemoglobin, arterial oxygen saturation, cardiac index, systemic vascular resistance index nor elevated lactate levels could be identified as individual risk factors.

Outcomes of different acute mesenteric ischemia therapies in the last 20 years: A meta-analysis and systematic review

OBJECTIVE

Acute mesenteric ischemia is a disease with high morbidity and mortality, and it is traditionally treated with open surgery. Endovascular therapy and hybrid techniques are alternative treatments that are also currently available. We performed a meta-analysis to evaluate the outcomes of the different treatment approaches in the last 20 years.

METHODS

Studies on acute mesenteric ischemia that were indexed in PubMed, Embase, and MEDLINE databases (from January 1, 2000, to April 1, 2021) were reviewed. All related retrospective observational studies and case series were included. A random-effects model was used to calculate pooled estimates, and the results were reported as proportions and 95% confidence intervals (CIs).

RESULTS

In our study, a total of 2369 patients (in 39 studies) underwent endovascular, open surgery, or retrograde open mesenteric stenting. The pooled mortality estimates for open surgery, endovascular therapy, and retrograde open mesenteric stenting were 40% (95% CI, 0.33-0.47; I² = 84%), 26% (95% CI, 0.19-0.33; I² = 33%), and 32% (95% CI, 0.21-0.44; I² = 26%), respectively.

CONCLUSIONS

The mortality associated with open surgical treatment, endovascular therapy, and retrograde open mesenteric stenting tend to be similar in the last 20 years.

Endovascular therapy in acute mesenteric ischemia after coronary artery bypass grafting: a case report and literature review

In the pattern of abdominal complications after cardiac surgery, acute mesenteric ischemia is rare but high-mortality pathology. In the initial stages, the disease has no specific signs, which makes it difficult to perform early multislice computed tomography to diagnose it. Risk stratification and an individual approach to the choice of diagnostic and therapeutic measures aimed at early restoration of mesenteric blood flow will reduce the mortality in this complication.

Intestinal thromboangiitis obliterans: a case report

Background

Thromboangiitis obliterans or Buerger’s disease is a form of peripheral vascular disease in young male smokers. The involvement of the intestine occurs in only about 2% of the cases, when they may present as acute abdomen due to mesenteric ischemia. The uncommonness of the condition makes it a less suspected differential diagnosis, leading to a delay in appropriate management, thereby increasing chances of morbidity or mortality. Cessation of smoking is known to stall the disease progression including visceral involvement, but may not always be the case as happened in the case being presented.

Case presentation

Our Indian Hindu male patient, a known smoker, presented with diffuse abdominal pain along with bouts of vomiting and loose motions. He had a prior history of amputation of the right foot, 4 years before. At presentation he had abdominal distension with diffuse tenderness and guarding. An omental band attached to the tip of the appendix was discovered at the initial exploration along with dilated proximal bowel loops, for which a release of the omental band along with appendectomy was done. He developed an enterocutaneous fistula on the 6th postoperative day for which he had to be reexplored, and multiple jejunal perforations were found. Segmental jejunal resection and a Roux-en-Y gastrojejunostomy with distal ileostomy were done along with a feeding jejunostomy. The patient however again had feculent discharge from the wound for which a third exploration was done. The gastrojejunostomy and feeding jejunostomy sites were leaky, both of which were repaired primarily. The patient developed septicemia which progressed to refractory septic shock, and he ultimately succumbed to his illness on the 23rd postoperative day of the index surgery.

Conclusion

Acute abdomen in a young man who is a chronic smoker and having an antecedent history of amputation of some part of an extremity for a nontraumatic cause should raise the suspicion of Buerger’s disease of the intestine. Although it is a progressive disease and the situation has already progressed by the time intestinal symptoms manifest, early detection may give some scope of salvage and decrease the morbidity and mortality.

A Comprehensive Way to Access Hospital Death Prediction Model for Acute Mesenteric Ischemia: A Combination of Traditional Statistics and Machine Learning

PURPOSE

This study aimed to use traditional statistics and machine learning to develop and validate prediction models for predicting hospital death in patients with AMI and compare these models' performance.

PATIENTS AND METHODS

Data were retrieved from the Medical Information Mart for Intensive Care (MIMIC III) electronic clinical database. A total of 338 eligible AMI patients were divided into a training cohort (n = 238) and a validation cohort (n = 100), and all patients were divided into survival groups and nonsurvival groups according to patients' hospital outcomes. The performance of the traditional statistics prediction model and the optimal machine learning prediction model was evaluated and compared with respect to discrimination, calibration, and clinical utility in the validation cohort.

RESULTS

Univariate and multivariate logistic regression analyses identified the following independent risk factors associated with hospital death for AMI in the training cohort, including diastolic blood pressure, blood lactate, blood creatinine, age, blood pH, and red blood cell distribution width. Both the nomogram (AUC = 77.0%, 67.9-86.1%) and optimal machine learning model (AUC = 82.9%, 74.9-91.0%) achieved good discrimination and calibration in the validation cohort. Decision curves analysis showed that the optimal machine learning model has a greater net benefit than that of nomogram in this study.

CONCLUSION

The nomogram achieved a concise and relatively accurate prediction of hospital death in patients with AMI, the machine learning model also has good discrimination and seems to have better clinical utility. Traditional statistics may help infer the relationship between risk factors and hospital death, while machine learning may contribute to a more accurate prediction. Traditional statistics and machine learning are complementary in developing the prediction model for hospital death of AMI. Therefore, a combination of nomogram-machine learning (Nomo-ML) predictive model may improve care and help clinicians make AMI management-related decisions.

Surgical Outcomes in Acute Mesenteric Ischemia: Has Anything Changed Over the Years?

BACKGROUND

Despite increases in knowledge and advances in the management of acute mesenteric ischemia syndrome (AMI), there have been no significant improvements in mortality in recent years. The objective of this study was to assess the changes in clinical characteristics and surgical outcomes in patients who underwent AMI over time.

METHODS

A total of 323 consecutive patients who underwent acute mesenteric ischemia at our institution between 1990 and 2015 were examined. The occurrence of significant changes over this 25-year period in demographic data, comorbidity, clinical characteristics, laboratory results, operative findings, etiology of the AMI, and operative mortality were evaluated. The evolution mortality rates for the studied period were analyzed using the additive logistic regression, and the significant effect was determined using the Akaike Information Criterion (AIC).

RESULTS

A significant increasing linear trend was observed in recent years in Charlson score values (p = 0.008), antiplatelet drug intake (p < 0.001), use of CT scan (p < 0.001), arterial thrombosis (p < 0.001), and intestinal resection (p = 0.047), while a decreasing linear trend was observed in digoxin intake (p < 0.001), angiography use (p = 0.004), and embolia (p < 0.001). The rest of the parameters did not present changes over time. Regarding the evolution of the adjusted surgical mortality, a significant decrease according the AIC criterion was observed.

CONCLUSIONS

In recent years, the characteristics of patients with AMI requiring surgery have changed. Changes in operative mortality have also been detected, showing a tendency toward a progressive and significant decrease.

Acute Mesenteric Ischemia

Background

Despite constant improvements in diagnostic as well as interventional and surgical techniques, acute mesenteric ischemia (AMI) remains a life-threatening emergency with high mortality rates. The time to diagnosis of AMI is the most important predictor of patients' outcome; therefore, prompt diagnosis and intervention are essential to reduce mortality in patients with AMI. The present review was performed to analyze potential risk factors and to help find ways to improve the outcome of patients with AMI.

Summary

Whereas AMI only applies to approximately 1% of all patients with an "acute abdomen," its incidence is rising up to 10% in patients >70 years of age. The initial clinical stage of AMI is characterized by a sudden onset of strong abdominal pain followed by a painless interval. Depending on the extent of disease, the symptoms of nonocclusive mesenteric ischemia (NOMI) and patients with a venous thrombosis can be very different from those of acute occlusive ischemia. Biphasic contrast-enhanced CT represents the gold standard for the diagnosis of arterial and venous occlusion. In case of a central occlusion of the superior mesenteric artery or signs of peritonitis, immediate surgery should be performed. If major bowel resection becomes necessary, critical residual intestinal length limits must be kept in mind. Endovascular techniques for arterial occlusion have taken on a much greater importance today. For stable patients with NOMI, interventional catheter angiography is recommended because it enables diagnosis and treatment with selective application of vasodilators. Depending on its degree, interventional treatment with a transhepatic catheter lysis should be considered for acute and chronic portal vein thrombosis.

Key Message

The prompt and targeted use of the appropriate diagnostics and interventions appears to be the only way to reduce the persistently high mortality rates for AMI.

Challenges Encountered during the Treatment of Acute Mesenteric Ischemia

RESULTS

Acute ischemia of the bowel mesentery was diagnosed in 41 patients (27 women and 14 men; mean age, 65.4 years). All patients underwent laparotomy. For 13 (31.71%) patients, surgery was performed within the first 24 hours of the clinical symptom onset. Mesenteric artery embolectomy without intestine resection was performed for 7 (17.07%) patients. Partial intestine resection due to necrosis was performed for 21 (51.22%) patients. Exploratory laparotomy without a therapeutic procedure was performed for 13 (31.71%) patients. Fifteen (36.59%) patients were discharged home in good general condition. Twenty-six (63.41%) patients died. The time from the clinical symptom onset until intervention exceeded 24 hours for all patients who died. Surgery within the first 24 hours reduced mortality associated with acute mesenteric ischemia (P = 0.001). Female sex, age older than 65 years, obesity (body mass index > 30), diabetes, chronic kidney disease, and smoking were adverse prognostic factors for increased mortality for patients with acute bowel ischemia.

CONCLUSION

The time from clinical symptoms to acute mesenteric ischemia treatment was the main prognostic factor and helped determine appropriate management. Early diagnosis and rapid intervention improved treatment outcomes and survival.

Role of Frailty and Comorbidity Status in Predicting Morbidity and Mortality in Patients with Acute Mesenteric Ischemia

BACKGROUND

This study was performed to determine the association of frailty and comorbidity status with postoperative morbidity and mortality in patients with acute mesenteric ischemia (AMI).

METHODS

Patients diagnosed with AMI between April 2006 and September 2019 were enrolled in this study. Frailty was evaluated by sarcopenia which was diagnosed by third lumbar vertebra psoas muscle area (PMA). Comorbidity status was evaluated by the Charlson Comorbidity Index (CCI) score. Univariate and multivariate analyses evaluating the risk factors for postoperative morbidity and mortality were performed.

RESULTS

Of the 174 patients, 86 were managed conservatively and 88 underwent surgery. In surgically managed patients, 39.8% developed complications within 30 days of surgery. Ten patients died within 30 days of the operation. In the univariate analyses, white blood cell >10 g/L, low PMA, CCI score ≥2, and bowel resection were associated with postoperative complications. Multivariate analysis revealed that low PMA, CCI score ≥2, and bowel resection were independent predictors of postoperative complications.

CONCLUSIONS

This study demonstrated that low PMA, CCI score ≥2, and bowel resection were independent risk factors for postoperative complications in patients with AMI. Preoperative assessment of frailty using PMA and the evaluation of comorbidity status using CCI may serve as helpful tools in preoperative risk assessment and should be integrated into scoring systems for surgically treated AMI.

Factors Associated With in-Hospital Death in Patients with Acute Mesenteric Artery Ischemia

Objective: The aim of the study was to assess the factors associated with increased mortality in patients with acute mesenteric ischemia, emphasizing the importance of an early diagnosis and a prompt surgical intervention in order to avoid lesion progression. Materials and method: A retrospective analytical study was conducted on a study population of 50 male and female patients with acute ischemia of the mesenteric arteries, aged between 36-92 years. Demographic and pathological history characteristics were assessed, together with presented symptoms, laboratory and CT findings, as well as surgical outcome and time-related aspects between presentation in the emergency department and time of surgery, as well as the hospitalization period until discharge or death. Results: Muscular defense (OR = 23.05) and shock (OR = 13.24) as symptoms were strongly associated with a poor prognosis, while elevated values of lactate dehydrogenase (p = 0.0440) and creatine kinase (p = 0.0025) were associated with higher death rates. The time elapsed during investigations in the emergency room was significantly higher in patients who deceased (p = 0.0023), similarly to the total time from the onset of symptoms to the beginning of surgery (p = 0.0032). Surgical outcomes showed that patients with segmental ischemia of the small bowel had significantly higher chances of survival (p <0.0001). Conclusion: Increased mortality rates in patients presenting in the emergency department for acute mesenteric ischemia were observed in patients with occlusion of the superior mesenteric artery, with higher levels of CK and LDH, as well as with longer periods of stay in the emergency department for diagnostic procedures until the commencement of the surgical intervention. Therefore, proper investigations in a timely manner followed by a specific and prompt surgical intervention may avoid unfavorable evolution of patients towards death.

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

Acute mesenteric ischemia (AMI) is typically defined as a group of diseases characterized by an interruption of the blood supply to varying portions of the small intestine, leading to ischemia and secondary inflammatory changes. If untreated, this process will eventuate in life threatening intestinal necrosis. The incidence is low, estimated at 0.09–0.2% of all acute surgical admissions. Therefore, although the entity is an uncommon cause of abdominal pain, diligence is always required because if untreated, mortality has consistently been reported in the range of 50%. Early diagnosis and timely surgical intervention are the cornerstones of modern treatment and are essential to reduce the high mortality associated with this entity. The advent of endovascular approaches in parallel with modern imaging techniques may provide new options. Thus, we believe that a current position paper from World Society of Emergency Surgery (WSES) is warranted, in order to put forth the most recent and practical recommendations for diagnosis and treatment of AMI. This review will address the concepts of AMI with the aim of focusing on specific areas where early diagnosis and management hold the strongest potential for improving outcomes in this disease process.

Some of the key points include the prompt use of CT angiography to establish the diagnosis, evaluation of the potential for revascularization to re-establish blood flow to ischemic bowel, resection of necrotic intestine, and use of damage control techniques when appropriate to allow for re-assessment of bowel viability prior to definitive anastomosis and abdominal closure.

Outcome of primary percutaneous stent-revascularization in patients with atherosclerotic acute mesenteric ischemia

Background Patients with acute mesenteric ischemia (AMI) often exhibit severe co-morbidities and significant surgical risks, leading to high perioperative morbidity. Purpose To investigate the feasibility of primary percutaneous stent-revascularization (PPSR) in atherosclerotic AMI and its impact on patients' outcome. Material and Methods Retrospective analysis of 19 consecutive patients (7 women, 12 men; median age, 69 years) with AMI caused by atherosclerotic, non-embolic stenoses/occlusions of the splanchnic arteries and PPSR. Alternative minimally invasive techniques were excluded. Clinical characteristics including the Charlson Comorbidity Index adjusted by age (CCIa) and symptom duration, technical and clinical success of PPSR, clinical course, 30-day mortality, and follow-up were evaluated and compared to literature data for surgical approaches. Technical success was defined as residual stenosis of <30% in diameter. Clinical success was defined as resolution of symptoms of AMI and/or normalization of serum lactate after sole PPSR. Results The majority of patients presented with severe co-morbidities (CCIa >4 in 17 of 19 patients, 89%). Median symptom duration was 50 h. Technical and clinical success rates of PPSR were 95% (21 of 22 arteries) and 53% (10 of 19 patients). Seven patients underwent subsequent laparotomy with bowel resection in four cases. Thirty-day mortality was 42% (8 of 19 patients). Conclusion In our study population of patients with atherosclerotic AMI, severe co-morbidities, prolonged acute symptoms, and significant perioperative risks PPSR of splanchnic stenoses were technically feasible and the clinical outcome was acceptable.

Acute mesenteric ischemia (Part II) - Vascular and endovascular surgical approaches

The modern treatment of acute mesenteric ischemia (AMI) requires seamless collaboration of gastrointestinal surgeons, vascular surgeons, and interventional radiologists. The treatment strategy is straightforward aiming at rapid restoration of blood flow to the intestine. Bowel resection is performed on demand. The first thing to consider is the patient's clinical condition at presentation, whether there are signs of peritonitis or not, and whether the patient is hemodynamically stable or not. Second, there are four etiologies of AMI that need to be distinguished as they differ in treatment: superior mesenteric artery embolism, mesenteric arterial occlusive disease, mesenteric venous thrombosis, and non-occlusive mesenteric ischemia. In this review, we describe the basic vascular and endovascular treatment modalities accompanied by a simple algorithm for the various situations in AMI. Furthermore, the indications for damage control and primary definitive surgery are discussed.

Mesenteric vascular treatment 2016: from open surgical repair to endovascular revascularization

The rise of endovascular techniques has improved the outcome of mesenteric ischemia. Key principle in reduction of morbidity and mortality is "revascularization first, resection later". We believe that mesenteric ischemia is a clinical challenge demanding 24/7 multidisciplinary team availability. This article describes the current insights into treatment of mesenteric ischemia.

Embolic superior mesenteric artery (SMA) occlusion secondary to a cardiac sarcoma

We present a case of embolic acute mesenteric ischaemia (AMI) secondary to an underlying cardiac sarcoma, an exceedingly rare presentation only reported twice before. A 46-year-old man presented to accident and emergency department during the night with severe abdominal pain and vomiting. An urgent CT angiograph demonstrated superior mesenteric artery (SMA) occlusion with ischaemic small bowel. Joint surgical effort from vascular and general surgeons successfully recanalised the SMA and a 20 cm segment of small bowel was resected. Postoperatively, an echocardiogram demonstrated a mass within the left atrium. After cardiothoracic resection, the mass was found to be a rare undifferentiated cardiac sarcoma. Further staining on the embolus retrieved from the SMA revealed scattered spindle cells with a similar immunohistochemistry profile to that of the resected cardiac sarcoma. The patient was subsequently discharged well on lifelong warfarin.