A method for predicting mortality in acute mesenteric ischemia: Machine learning.

BACKGROUND: This study aimed to develop and validate an artificial intelligence model using machine learning (ML) to predict hospital mortality in patients with acute mesenteric ischemia (AMI). METHODS: A total of 122 patients diagnosed with AMI at Sakarya University Training and Research Hospital between January 2011 and June 2023 were included in the study. These patients were divided into a training cohort (n=97) and a validation cohort (n=25), and further categorized as survivors and non-survivors during hospitalization. Serum-based laboratory results served as features. Hyperfeatures were eliminated using Recursive Feature Elimination (RFE) in Python to optimize outcomes. ML algorithms and data analyses were performed using Python (version 3.7). RESULTS: Of the patients, 56.5% were male (n=69) and 43.5% were female (n=53). The mean age was 71.9 years (range 39-94 years). The mortality rate during hospitalization was 50% (n=61). To achieve optimal results, the model incorporated features such as age, red cell distribution width (RDW), C-reactive protein (CRP), D-dimer, lactate, globulin, and creatinine. Success rates in test data were as follows: logistic regression (LG), 80%; random forest (RF), 60%; k-nearest neighbor (KN), 52%; multilayer perceptron (MLP), 72%; and support vector classifier (SVC), 84%. A voting classifier (VC), aggregating votes from all models, achieved an 84% success rate. Among the models, SVC (sensitivity 1.0, specificity 0.77, area under the curve (AUC) 0.90, Confidence Interval (95%): (0.83-0.84)) and VC (sensitivity 1.0, specificity 0.77, AUC 0.88, Confidence Interval (95%): (0.83-0.84)) were noted for their effectiveness. CONCLUSION: Independent risk factors for mortality were identified in patients with AMI. An efficient and rapid method using various ML models to predict mortality has been developed.

Biomarkers In Prediction of Acute Mesenteric Ischaemia: a prospective multicentre study (BIPAMI study): a study protocol.

BACKGROUND: Acute mesenteric ischaemia (AMI) is a life-threatening disease where early diagnosis is critical to avoid morbidity and mortality from extensive irreversible bowel necrosis. Appropriate prediction of presence of bowel necrosis is currently not available but would help to choose the optimal method of treatment. The study aims to identify combinations of biomarkers that can reliably identify AMI and distinguish between potentially reversible and irreversible bowel ischaemia. METHODS: This is a prospective multicentre study. Adult patients with clinical suspicion of AMI (n = 250) will be included. Blood will be sampled on admission, at and after interventions, or during the first 48 h of suspicion of AMI if no intervention undertaken. Samples will be collected and the following serum or plasma biomarkers measured at Tartu University Hospital laboratory: intestinal fatty acid-binding protein (I-FABP), alpha-glutathione S-transferase (Alpha- GST), interleukin 6 (IL-6), procalcitonin (PCT), ischaemia-modified albumin (IMA), D-lactate, D-dimer, signal peptide-CUB-EGF domain-containing protein 1 (SCUBE-1) and lipopolysaccharide-binding protein (LBP). Additionally, more common laboratory markers will be measured in routine clinical practice at study sites. Diagnosis of AMI will be confirmed by computed tomography angiography, surgery, endoscopy or autopsy. Student's t or Wilcoxon rank tests will be used for comparisons between transmural vs. suspected (but not confirmed) AMI (comparison A), confirmed AMI of any stage vs suspected AMI (comparison B) and non-transmural AMI vs transmural AMI (comparison C). Optimal cut-off values for each comparison will be identified based on the AUROC analysis and likelihood ratios calculated. Positive likelihood ratio > 10 (> 5) and negative likelihood ratio < 0.1 (< 0.2) indicate high (moderate) diagnostic accuracy, respectively. All biomarkers with at least moderate accuracy will be entered as binary covariates (using the best cutoffs) into the multivariable stepwise regression analysis to identify the best combination of biomarkers for all comparisons separately. The best models for each comparison will be used to construct a practical score to distinguish between no AMI, non-transmural AMI and transmural AMI. DISCUSSION: As a result of this study, we aim to propose a score including set of biomarkers that can be used for diagnosis and decision-making in patients with suspected AMI. TRIAL REGISTRATION: NCT06212921 (Registration Date 19-01-2024).

Preoperative risk factors for 90-day postoperative mortality outcome in patients with non-occlusive mesenteric ischemia.

PURPOSE: The mortality rate for non-occlusive mesenteric ischemia remains high even after patients survive the acute postoperative period with tremendous treatment efforts, including emergency surgery, which is challenging. The aim of this study was to explore the preoperative risk factors for 90-day postoperative mortality in patients with non-occlusive mesenteric ischemia. METHODS: This single-center, retrospective cohort study included patients diagnosed with non-occlusive mesenteric ischemia who underwent emergency surgery between August 2014 and January 2023. All patients were divided into survival-to-discharge and mortality outcome groups at the 90-day postoperative follow-up. Preoperative factors, including comorbidities, preoperative status of vital signs and consciousness, blood gas analysis, blood test results, and computed tomography, were compared between the two groups. RESULTS: Twenty patients were eligible, and 90-day mortality was observed in 10 patients (50%). The mortality outcome group had significantly lower HCO3- (20.9 vs. 14.6, p = 0.006) and higher lactate (4.4 vs. 9.4, p = 0.023) levels than did the survival outcome group. The median postoperative time to death was 19 [2-69] days, and five patients (50%) died after postoperative day 30, mainly because hemodialysis was discontinued because of hemodynamic instability in patients requiring hemodialysis. CONCLUSION: Low preoperative HCO3- and high lactate levels may be preoperative risk factors for 90-day postoperative mortality in patients with non-occlusive mesenteric ischemia. However, patients on hemodialysis die from discontinuing hemodialysis even after surviving the acute postoperative phase. Therefore, indications for emergency surgery in patients with risk factors for postoperative mortality should be carefully determined.

Association between Postoperative Adjuvant Vasodilator Therapy and In-Hospital Mortality for Non-Occlusive Mesenteric Ischemia: A Nationwide Observational Study.

BACKGROUND: Although several clinical guidelines recommend vasodilator therapy for non-occlusive mesenteric ischemia (NOMI) and immediate surgery when bowel necrosis is suspected, these recommendations are based on limited evidence. METHODS: In this retrospective nationwide observational study, we used information from the Japanese Diagnosis Procedure Combination inpatient database from July 2010 to March 2018 to identify patients with NOMI who underwent abdominal surgeries on the day of admission. We compared patients who received postoperative vasodilator therapy (vasodilator group) with those who did not (control group). Vasodilator therapy was defined as venous and/or arterial administration of papaverine and/or prostaglandin E1 within 2 days of admission. The primary outcome was in-hospital mortality. Secondary outcomes included the prevalence of additional abdominal surgery performed ≥3 days after admission and short bowel syndrome. RESULTS: We identified 928 eligible patients (149 in the vasodilator group and 779 in the control group). One-to-four propensity score matching yielded 149 and 596 patients for the vasodilator and control groups, respectively. There was no significant difference in in-hospital mortality between the groups (control vs. vasodilator, 27.5% vs. 30.9%; risk difference, 3.4%; 95% confidence interval, -4.9 to 11.6; p=0.42) and no significant difference in the prevalences of abdominal surgery, bowel resection ≥3 days after admission, and short bowel syndrome. CONCLUSIONS: Postoperative vasodilator use was not significantly associated with a reduction in in-hospital mortality or additional abdominal surgery performed ≥3 days after admission in surgically treated NOMI patients.

Copenhagen Mesenteric stent study (COMESS)-a randomized trial of stent versus covered stent treatment for chronic mesenteric ischemia.

BACKGROUND: Current management of mesenteric ischemia is primarily endovascular stent treatment. Typical CMI symptoms are postprandial abdominal pain, food fear, weight loss, and diarrhea. Revascularization is often necessary, as mesenteric ischemia may progress to bowel necrosis and death if left untreated. This study aims to compare the outcome using bare metal stent (BMS) or covered stent (CS) in the endovascular treatment of chronic and acute on chronic mesenteric ischemia. METHODS: This is an investigator-driven, prospective, randomized, single-blinded, and single-center, national cohort study at the Copenhagen University Hospital, Denmark. A total of 98 patients with chronic mesenteric ischemia (CMI) and acute-on-chronic mesenteric ischemia (AoCMI) will be randomized to treatment with either BeSmooth BMS (Bentley Innomed GmbH) or BeGraft CS (Bentley Innomed GmbH). Randomization occurs intraoperatively after lesion crossing. DISCUSSION: There is currently no published data from prospective controlled trials regarding the preferred type of stent used for the treatment of chronic and acute-on-chronic mesenteric ischemia. This trial will evaluate the short- and long-term outcome of BMS versus CS when treating CMI and AoCMI, as well as the benefit of a more intense postoperative surveillance program. TRIAL REGISTRATION: ClinicalTrials.gov NCT05244629. Registered on February 8, 2022.

Predictors of Survival Without Intestinal Resection after First-Line Endovascular Revascularization in Patients with Acute Arterial Mesenteric Ischemia.

Background Acute arterial mesenteric ischemia requires emergency treatment and is associated with high mortality rate and poor quality of life. Identifying factors associated with survival without intestinal resection (hereafter, intestinal resection-free [IRF] survival) could help in treatment decision-making after first-line endovascular revascularization. Purpose To identify factors associated with 30-day IRF survival in patients with acute arterial mesenteric ischemia whose first-line treatment was endovascular revascularization. Materials and Methods Patients with acute arterial mesenteric ischemia whose first-line treatment was endovascular revascularization because of a low probability of bowel necrosis were included in this single-center retrospective cohort (May 2014 to August 2022). Patient demographics, laboratory values, clinical characteristics at admission, CT scans, angiograms, and endovascular revascularization-related variables were included. The primary end point was 30-day IRF survival, and secondary end points were 3-month, 1-year, and 3-year overall survival. Factors independently associated with 30-day IRF survival were identified with binary logistic regression. Results A total of 117 patients (median age, 70 years [IQR, 60-77]; 53 female, 64 male) were included. Within 30 days after revascularization, 73 of 117 patients (62%) survived without resection, 28 of 117 (24%) survived after resection, 14 of 117 (12%) died without resection, and two of 117 (2%) underwent resection but died. The 30-day IRF survival was 63% (74 of 117). The 3-month, 1-year, and 3-year mortality rate was 18% (21 of 117), 21% (25 of 117), and 27% (32 of 117), respectively. Independent predictors of 30-day IRF survival were persistent bowel enhancement at initial CT (odds ratio [OR], 0.3; 95% CI: 0.2, 0.8; P = .013) and C-reactive protein (CRP) level less than 100 mg/L (OR, 0.3; 95% CI: 0.1, 0.8; P = .002). The 30-day IRF survival was 86%, 61%, 47%, and 23% in patients with both favorable features, persistent bowel enhancement but CRP level greater than 100 mg/L, no bowel enhancement but CRP level less than 100 mg/L, and both unfavorable features, respectively. Conclusion Independent predictors associated with 30-day IRF survival in patients with acute arterial mesenteric ischemia whose first-line treatment was endovascular revascularization were persistent bowel wall enhancement at initial CT and CRP level less than 100 mg/L. © RSNA, 2024 Supplemental material is available for this article.

Surgical choice for the treatment of partial intestinal ischemic necrosis caused by acute type a aortic dissection combined with malperfusion of superior mesenteric artery.

Acute type A aortic dissection is a severe cardiovascular disease characterized by rapid onset and high mortality. Traditionally, urgent open aortic repair is performed after admission to prevent aortic rupture and death. However, when combined with malperfusion syndrome, the low perfusion of the superior mesenteric artery can further lead to intestinal necrosis, significantly impacting the surgery's prognosis and potentially resulting in adverse consequences, bringing. This presents great significant challenges in treatment. Based on recent domestic and international research literature, this paper reviews the mechanism, current treatment approaches, and selection of surgical methods for poor organ perfusion caused by acute type A aortic dissection. The literature review findings suggest that central aortic repair can be employed for the treatment of acute type A aortic dissection with inadequate perfusion of the superior mesenteric artery. The superior mesenteric artery can be windowed and (/or) stented, followed by delayed aortic repair. Priority should be given to revascularization of the superior mesenteric artery, followed by central aortic repair. During central aortic repair, direct blood perfusion should be performed on the distal true lumen of the superior mesenteric artery, leading to resulting in favorable therapeutic outcomes. The research results indicate that even after surgical aortic repair, intestinal ischemic necrosis may still occur. In such cases, prompt laparotomy and necessary necrotic bowel resection are crucial for saving the patient's life.

Scoping Review of Clinical Presentations and Outcomes in Patients with Concomitant COVID-19 Infection and Acute Mesenteric Ischaemia.

OBJECTIVES: COVID-19 infection confers an increased risk of coagulation dysfunction (1) predisposing to thromboembolism in many anatomical sites including the gastrointestinal tract (GIT) (2). This study investigates the clinical presentation and outcome in patients presenting with concurrent COVID-19 infection and gastrointestinal tract ischaemia. Furthermore, differentiation and comparisons are drawn between those with arterial and venous aetiology for mesenteric ischaemia. METHODS: A systematic search was undertaken on EMBASE, PubMed, and MEDLINE. Two independent reviewers screened titles, abstracts, and full-text articles according to the inclusion criteria and extracted relevant data. Data analyses were conducted using Excel®. RESULTS: Forty-one studies were included in the data analyses, yielding 44 patients. Twenty-six patients had mesenteric arterial occlusion, sixteen patients had mesenteric venous occlusion, and two patients had both arterial and venous mesenteric occlusion. All patients had concurrent COVID-19 infection. The survival rate in patients with arterial aetiology was 38.5% in contrast to 68.8% in patients with venous aetiology. Twelve patients (29.3%) experienced respiratory symptoms in the community before the onset of gastrointestinal symptoms, and five (12.2%) developed gastrointestinal symptoms during their inpatient stay for COVID-19 pneumonitis. CONCLUSIONS: Acute mesenteric ischaemia presents a clinical challenge to diagnose due to its non-specific symptoms. Concurrent COVID-19 infection with its predominant respiratory symptoms adds a further challenge in recognising the non-specific symptoms of mesenteric ischaemia. Our study draws attention to the increased thromboembolic risk posed by COVID-19 infection and the need for a high index of suspicion to aid prompt diagnosis and management of acute mesenteric ischaemia, even in the post-pandemic era.

The open abdomen in mesenteric ischemia: A tool for patients undergoing revascularization.

BACKGROUND: We examined outcomes in Acute Mesenteric Ischemia (AMI) with the hypothesis that Open Abdomen (OA) is associated with decreased mortality. METHODS: We performed a cohort study reviewing NSQIP emergency laparotomy patients, 2016-2020, with a postoperative diagnosis of mesenteric ischemia. OA was defined using flags for patients without fascial closure. Logistic regression was used with outcomes of 30-day mortality and several secondary outcomes. RESULTS: Out of 5514 cases, 4624 (83.9%) underwent resection and 387 (7.0%) underwent revascularization. The OA rate was 32.6%. 10.8% of patients who were closed required reoperation. After adjustment for demographics, transfer status, comorbidities, preoperative variables including creatinine, white blood cell count, and anemia, as well as operative time, OA was associated with OR 1.58 for mortality (95% CI [1.38, 1.81], p < 0.001). Among revascularizations, there was no such association (p = 0.528). OA was associated with ventilator support >48 h (OR 4.04, 95% CI [3.55, 4.62], and p < 0.001). CONCLUSION: OA in AMI was associated with increased mortality and prolonged ventilation. This is not so in revascularization patients, and 1 in 10 patients who underwent primary closure required reoperation. OA should be considered in specific cases of AMI. LEVEL OF EVIDENCE: Retrospective cohort, Level III.

Treatment outcomes in patients with acute thromboembolic occlusion of the superior mesenteric artery.

OBJECTIVES: The goals of this study were to investigate the treatment outcomes of acute thromboembolic occlusion of the superior mesenteric artery (ATOS) and identify prognostic factors after treatment. METHODS: The clinical data of 62 patients with ATOS between 2013 and 2021 were retrospectively reviewed. Patients were stratified by the treatment strategy, complications and mortality were compared in different group. RESULTS: Sixty-two consecutive patients were identified with ATOS. The median patient age was 69 years (interquartile range 58-79 years). Endovascular therapy was initiated in 21 patients, and 4 patients received conservative treatment. Open surgery was performed first in the remaining 37 patients. The technical success rates of the endovascular first group and open surgery group were 90.5% and 97.3%, respectively. One patient in the conservative treatment group had progression of ischemia to extensive bowel necrosis. There was no difference in 30-day mortality between these groups. Predictors of 30-day mortality included initial neutrophil count > 12* 103/dL, age over 60 years old and history of chronic renal insufficiency. CONCLUSIONS: Endovascular treatment or conservative treatment may be adopted in selected patients who do not exhibit signs and symptoms of bowel necrosis, and close monitoring for bowel necrosis is important. The increase in preoperative neutrophil count, age over 60 years old and history of chronic renal insufficiency were poor prognostic factors.

Potential Indicators of Intestinal Necrosis in Portal Venous Gas: A Case Report of an 82-Year-Old Woman on Long-Term Hemodialysis with Ascites and Pneumatosis Coli.

BACKGROUND Several factors have been reported as possible predictors of intestinal necrosis in patients with portal venous gas (PVG). We describe potential indicators of intestinal necrosis in PVG identified by contrasting 3 episodes of PVG in a patient on hemodialysis against previously verified factors. CASE REPORT An 82-year-old woman undergoing hemodialysis was admitted to our hospital thrice for acute abdominal pain. On first admission, she was alert, with a body temperature of 36.3°C, blood pressure (BP) of 125/53 mmHg, pulse rate of 60/min, respiratory rate of 18/min, and 100% oxygen saturation on room air. Computed tomography (CT) revealed PVG, intestinal distension, poor bowel wall enhancement, bubble-like pneumatosis in the intestinal wall, and minimal ascites. PVG caused by intestinal ischemia was diagnosed, and she recovered after bowel rest and hydration. Three months later, she had a second episode of abdominal pain. BP was 115/56 mmHg. CT revealed PVG and a slight accumulation of ascites, without pneumatosis in the intestinal wall. She again recovered after conservative measures. Ten months later, the patient experienced a third episode of abdominal pain, with BP of 107/52 mmHg. CT imaging indicated PVG, considerable ascites, and linear pneumatosis of the intestinal walls. Despite receiving conservative treatment, the patient died. CONCLUSIONS A large accumulation of ascites and linear pneumatosis in the intestinal walls could be potential indicators of intestinal necrosis in patients with PVG caused by intestinal ischemia. As previously reported, hypotension was further confirmed to be a reliable predictor of intestinal necrosis.

A visceral organ function-focused therapeutic strategy using a 6-hour time window for patients with acute type a aortic dissection complicated by mesenteric malperfusion.

BACKGROUND: Acute type A aortic dissection (ATAAD) complicated by mesenteric malperfusion is a critical and complicated condition. The optimal treatment strategy remains controversial, debate exists as to whether aortic dissection or mesenteric malperfusion should be addressed first, and the exact time window for mesenteric ischemia intervention is still unclear. To solve this problem, we developed a new concept based on the pathophysiological mechanism of mesenteric ischemia, using a 6-hour time window to divide newly admitted patients by the time from onset to admission, applying different treatment protocols to improve the clinical outcomes of patients with ATAAD complicated by mesenteric malperfusion. METHODS: This was a retrospective study that covered a five-year period. From July 2018 to December 2020(phase I), all patients underwent emergency open surgery. From January 2021 to June 2023(phase II), patients with an onset within 6 h all underwent open surgical repair, followed by immediately postoperative examination if the malperfusion is suspected, while the restoration of mesenteric perfusion and visceral organ function was performed first, followed by open repair, in patients with an onset beyond 6 h. RESULTS: There were no significant differences in baseline and surgical data. In phase I, eleven patients with mesenteric malperfusion underwent open surgery, while in phase II, our novel strategy was applied, with sixteen patients with an onset greater than 6 h and eleven patients with an onset less than 6 h. During the waiting period, none died of aortic rupture, but four patients died of organ failure, twelve patients had organ function improvement and underwent surgery successfully survived. The overall mortality rate decreased with the use of this novel strategy (54.55% vs. 18.52%, p = 0.047). Furthermore, the surgical mortality rate between the two periods showed even stronger statistical significance (54.55% vs. 4.35%, p = 0.022). Moreover, the proportions of patients with sepsis and multiorgan failure also showed differences. CONCLUSIONS: Our novel strategy for patients with ATAAD complicated by mesenteric malperfusion not only improves the surgical success rate but also reduces the overall mortality rate.