The Ongoing Challenge of Acute Mesenteric Ischemia

Mesenteric Ischemia after Cardiac Surgery

BACKGROUND

 Mesenteric ischemia (Me-Is) after cardiac surgery is underreported in present literature but has still earned the bad reputation of a dismal prognosis. This study adds clinical outcomes in a large patient cohort.

METHODS

 Between 2009 and 2019 of the 22,590 patients undergoing cardiac surgery at our facility 106 (0.47%) developed Me-Is postoperatively. Retrospective patient data was analyzed. Additionally, patients were stratified by outcome-survivors and nonsurvivors.

RESULTS

 Patients were predominantly male (n = 68, 64.2%), mean age was 71.2 ± 9.3 years. Most procedures were elective (n = 85, 80.2%) and comprised of more complex combined procedures (50.9%) and redos (17.9%). Mean EuroSCORE II averaged 10.9 ± 12.2%. Survival at 30 days was 49.1% (n = 52). Clinical baseline and procedural characteristics did not differ significantly between survivors and nonsurvivors. The median postoperative interval until symptom onset was 5 days in both groups. Survivors were more frequently diagnosed by computed tomography and nonsurvivors based on clinical symptoms. Me-Is was predominantly nonocclusive (n = 84, 79.2%). Laparotomy was the main treatment in both groups (n = 45, 78.8% vs. n = 48, 88.9%, p = 0.94). Predictors of mortality were maximum norepinephrine doses (hazard ratio [HR] 8.29, confidence interval [CI] 3.39-20.26, p < 0.0001), lactate levels (HR 1.06, CI 1.03-1.09), and usage of inotropes (HR 2.46, CI 1.41-4.30).

CONCLUSION

 The prognosis of Me-Is following cardiac surgery is poor-independently from diagnostic or treatment patterns. There exists a significant asymptomatic time period postoperatively, in which pathophysiologic processes seem to cross the Rubicon. After clinical demarcation, the further course can almost no longer be influenced.

The Diagnostic Value of Biomarkers in Acute Mesenteric Ischaemia Is Insufficiently Substantiated: A Systematic Review

OBJECTIVE

There is an urgent need for accurate biomarkers to support timely diagnosis of acute mesenteric ischaemia (AMI) and thereby improve clinical outcomes. With this systematic review, the aim was to substantiate the potential diagnostic value of biomarkers for arterial occlusive AMI.

DATA SOURCES

The Pubmed, Embase, and the Cochrane Library electronic databases were searched.

REVIEW METHODS

A systematic review of the literature has been conducted to define the potential diagnostic value of biomarkers for arterial occlusive AMI. All studies including ≥ 10 patients describing biomarkers for macrovascular occlusive AMI between 1950 and 17 February 2023 were identified within the Pubmed, Embase, and the Cochrane Library electronic databases. There were no restrictions to any particular study design, but letters and editorials were excluded. The QUADAS-2 tool was used for the critical appraisal of quality. The study protocol was registered on Prospero (CRD42021254970).

RESULTS

Fifty of 4334 studies were eligible for inclusion in this review. Ninety per cent of studies were of low quality. A total of 60 biomarkers were identified, with 24 in two or more studies and 15 in five or more studies. There was variation in reported units, normal range, and cut off values. Meta-analysis was not possible due to study heterogeneity. Biomarkers currently recommended by the European Journal of Vascular and Endovascular Surgery, European Society for Trauma and Emergency Surgery 2016, and World Society of Emergency Surgery 2017 guidelines also had heterogeneous low quality data for use in the diagnosis of AMI.

CONCLUSION

This systematic review demonstrates high heterogeneity and low quality of the available evidence on biomarkers for arterial occlusive AMI. No clinical conclusions can be drawn on a biomarker or combination of biomarkers for patients suspected of arterial occlusive AMI. Restraint is advised when rejecting or determining AMI solely based on biomarkers.

Irreversible Transmural Intestinal Necrosis in Acute Mesenteric Ischemia: Retrospective Cohort Study from a High-Volume Hospital

Background: Owing to the low incidence rate and nonspecific symptoms of acute mesenteric ischemia (AMI), the identification and prediction of irreversible transmural intestinal necrosis (ITIN) and extensive bowel resection (≥100 cm) (EBR) are difficult and critical. This study aimed to investigate the risk factors for ITIN and EBR in patients with AMI. Methods: The clinical data of 254 AMI patients were retrospectively analyzed. Furthermore, the incidence of ITIN and EBR were set as dependent variables, and relevant risk factors were screened using univariate and multivariate logistic regression analyses. The comparisons of surgical characteristics and postoperative recovery outcomes between the EBR and control group were also conducted. Results: The presence of hemorrhagic (odds ratio [OR] = 28.356, P < .001) or other types ascites (OR = 13.051, P = .003), peritonitis (OR = 8.463, P = .005), intestinal diameter >2.35 cm (OR = 5.493, P = .020), and serum creatinine (CREA) >95 μmol/L (OR = 4.866, P = .048) were identified as independent risk factors for ITIN in patients with AMI. In addition, serum C-reactive protein (CRP) >15 mg/L (OR = 38.023, P = .006), and CREA >100 μmol/L (OR = 6.248, P = .035) were proved to be independently associated with EBR for ITIN cases. Compared to the control group, EBR significantly increased the likelihood of requiring enterostomy (P = .001), blood transfusion (P = .002), and transfer to intensive care unit (P = .016), while also prolonging the recovery time for intestinal function (P = .014). Conclusions: The presence of ascites, peritonitis, intestinal diameter >2.35 cm, and serum CREA >95 μmol/L were independently correlated with ITIN for AMI cases, while serum CRP >15 mg/L and CREA >100 μmol/L independently increased the risk of EBR.

Automatic detection of ischemic necrotic sites in small intestinal tissue using hyperspectral imaging and transfer learning

Acquiring large amounts of hyperspectral data of small intestinal tissue with real labels in the clinic is difficult, and the data shows inter-patient variability. Building an automatic identification model using a small dataset presents a crucial challenge in obtaining a strong generalization of the model. This study aimed to explore the performance of hyperspectral imaging and transfer learning techniques in the automatic identification of normal and ischemic necrotic sites in small intestinal tissue. Hyperspectral data of small intestinal tissues were collected from eight white rabbit samples. The transfer component analysis (TCA) method was performed to transfer learning on hyperspectral data between different samples and the variability of data distribution between samples was reduced. The results showed that the TCA transfer learning method improved the accuracy of the classification model with less training data. This study provided a reliable method for single-sample modelling to detect necrotic sites in small intestinal tissue .

Iodine density mapping for the diagnosis of acute bowel ischemia using fast kV-switching dual-energy CT

PURPOSE

To evaluate the diagnostic capabilities of a supplementary color ramped iodine density map compared to virtual monoenergetic images (VMIs) at 74 keV in the diagnosis of acute bowel ischemia (ABI).

METHODS

Data for this study were prospectively gathered and retrospectively evaluated. Patients referred to the Department of Diagnostic Radiology between October 2020 and August 2022 on the suspicion of ABI and underwent surgery < 12 h following fast kV-switching venous phase abdominal dual-energy CT (DECT) were consecutively included. Images were evaluated by two board-certified radiologists and two radiology residents. First round included only 74 keV VMIs resembling conventional 120 kVp images, and the second round included a supplementary iodine density map. Readers were asked to register presence of ABI as well as their confidence in their diagnosis based on a 5-point Likert scale. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated for each observer with the surgical findings as the gold-standard. McNemar's and Wilcoxon signed-rank test were used to compare registrations and diagnostic confidence across assessment rounds.

RESULTS

A total of 29 patients resulting in 31 DECT scans were included. Fourteen cases of ischemic/necrotic bowel were reported following surgery. Sensitivity and NPV were decreased with the use of supplementary iodine map images compared to 120 kVp-like images without supplementary iodine map images for three of four observers (round 1 range: 71.4-92.9% and 78.0-94.8%; round 2 range: 57.1-78.6% and 70.1-83.3%, respectively), while specificity and PPV were increased for three of four observers (round 1 range: 64.7-94.1% and 67.4-93.1%; round 2 range: 88.2-94.1% and 73.8-91.1%, respectively). However, no significant difference in ABI diagnosis or diagnostic confidence was found (p-value range: 0.07-1.00 and 0.23-0.58, respectively).

CONCLUSION

No significant difference for the diagnosis of ABI was found using supplementary iodine mapping. Our study may suggest a trend of increased specificity and decreased sensitivity, hence, the use of supplementary iodine mapping should be carefully considered.

Outcome of laparotomy and conservative treatment of patients with acute mesenteric venous ischemia with viable bowel

BACKGROUND

Acute mesenteric ischemia (AMI) is one of the most serious abdominal emergencies. Predicting the onset of bowel necrosis that warrants surgical intervention is of paramount importance in AMI. The present study aimed to investigate the outcome of patients with AMI secondary to mesenteric venous occlusion (MVO) and the consequence of non-therapeutic exploratory laparotomy.

METHODS

The records of 132 patients with AMI were retrospectively reviewed. The outcome of patients with acute mesenteric venous ischemia (AMVI) and viable bowel was analyzed based on the method of treatment: conservative versus surgical. The impact of non-therapeutic laparotomy on the outcome of patients with AMVI in terms of morbidity, readmission, and mortality was analyzed.

RESULTS

Forty-seven patients (34 male) with AMVI had viable bowel. Of the 47 patients with viable bowel, 8 (17%) had an exploratory non-therapeutic laparotomy, whereas 39 patients were treated conservatively. Patients who had non-therapeutic laparotomy had significantly higher complication (50 vs 5.1%, p = 0.005) and readmission rates (37.5 vs 5.1%, p = 0.03) and longer hospital stay (8.5 vs 7 days, p = 0.02) than those treated conservatively. Patients with bowel necrosis who had a therapeutic laparotomy had slightly lower rates of morbidity and mortality as compared to patients with viable bowel who underwent a non-therapeutic laparotomy.

CONCLUSION

Careful assessment and informed decision-making in patients with AMVI are crucial to avoid unnecessary surgical intervention that can result in higher rates of complications and readmission and extended hospital stay.

Research of Importance of Thiol, CRP and Lactate in Diagnosing Mesenteric Ischemia At An Early Stage: Animal Model

INTRODUCTION AND PURPOSE

Acute mesenteric ischemia is especially seen in the elderly population. It has an increasing incidence in today's world where the average life expectancy is increasing. Early diagnosis is the most important factor reducing morbidity and mortality, and there is still no marker with high sensitivity and specificity for early diagnosis.In this study, we aimed to find a more sensitive and specific serum marker in the early diagnosis of mesenteric ischemia by comparing thiol with the currently used markers C-reactive protein and lactate.

MATERIALS AND METHODS

In our study, 32 Wistar Albino male rats, 10-12 weeks old, weighing 250-300 g, were used. 32 rats were divided into 4 groups, one of which was the control group. The superior mesenteric artery of the other 3 groups was ligated. Blood samples were taken after 2 hours from the first group, 4 hours from the second group, and 6 hours from the third group. Then the rats were sacrificed. Mesenteric ischemia and its level were observed in sacrificed subjects. The samples were separated under appropriate conditions and analyzed biochemically.

RESULTS

As the ischemia time increased, CRP increased and this increase was found to be statistically insignificant (p>0.05). The changes in lactate were found to be statistically significant (p<0.05). The difference between the changes of total and native thiol values was found to be statistically significant (p<0.05).

CONCLUSION

Although CRP is a non-specific parameter in the early diagnosis of acute mesenteric ischemia, lactate maintains its importance as seen in our study. Differences in total thiol and native thiol changes were statistically significant. The fact that this significant difference is observed at the 4th hour values, reveals the importance of these parameters in early diagnosis. Thanks to the economic and fast results of thiol parameters, it is thought that new studies to be added to the literature can lead to the diagnosis of mesenteric ischemia.

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.

Discrimination between normal and necrotic small intestinal tissue using hyperspectral imaging and unsupervised classification

Objective and automatic clinical discrimination of normal and necrotic sites of small intestinal tissue remains challenging. In this study, hyperspectral imaging (HSI) and unsupervised classification techniques were used to distinguish normal and necrotic sites of small intestinal tissues. Small intestinal tissue hyperspectral images of eight Japanese large-eared white rabbits were acquired using a visible near-infrared hyperspectral camera, and K-means and density peaks (DP) clustering algorithms were used to differentiate between normal and necrotic tissue. The three cases in this study showed that the average clustering purity of the DP clustering algorithm reached 92.07% when the two band combinations of 500-622 and 700-858 nm were selected. The results of this study suggest that HSI and DP clustering can assist physicians in distinguishing between normal and necrotic sites in the small intestine in vivo.

Role of spleen density in predicting postoperative complications in patients with acute mesenteric ischemia

BACKGROUND

Acute mesenteric ischemia (AMI) is a life-threatening surgical emergency with a poor prognosis. This study assessed the association of diffuse reduction of spleen density (DROSD) with postoperative complications and identified risk factors for adverse outcomes in AMI patients after surgery.

METHODS

Patients who were diagnosed with AMI and underwent surgical operations between April 2006 and July 2021 were enrolled. Spleen density was assessed using preoperative non-enhanced computed tomography. The lowest quartile of spleen density in all patients was regarded as the cutoff value for DROSD. Univariate and multivariate analyses were performed to determine the risk factors related to postoperative outcomes after surgery.

RESULTS

According to the diagnostic cutoff, patients with a spleen density ≤49.07 HU were defined as DROSD. In a cohort of 97 patients, 34.0% developed complications within 30 days of surgery. The multivariate analysis illustrated that DROSD was an independent risk factor for prognostic outcomes in AMI patients after surgery.

CONCLUSION

Patients with low spleen density were prone to postoperative complications. As an imaging method, preoperative assessment of spleen density is a novel predictor that can be used clinically to identify high-risk AMI patients with poor prognosis.

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.

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.

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.

Superior mesenteric artery embolism after radiofrequency ablation in regularly anticoagulated patients with paroxysmal atrial fibrillation: a case report

BACKGROUND

Superior mesenteric artery embolism (SMAE) is a rare cause of acute abdomen, and the fatality rate is extremely high if it is not diagnosed and treated in time. Due to the lack of knowledge and experience of nonspecialist physicians, it is easy to misdiagnose. Radiofrequency ablation (RFA) has become the first-line treatment strategy for atrial fibrillation (AF). Thromboembolic events are some of the major complications after RFA, whereas SMAE is rarely reported.

CASE PRESENTATION

A 70 year-old woman with paroxysmal AF who regularly took anticoagulant drugs for 3 months experienced abdominal pain after RFA. At the outset, she was misdiagnosed as mechanical intestinal obstruction. When the patient presented with blood in the stool, abdominal enhancement computed tomography was conducted and showed a small bowel perforation. Immediate laparotomy was performed, and the final diagnosis was SMAE.

CONCLUSION

It is suggested that for unexplained abdominal pain after RFA of AF, the possibility of SMAE should be considered, and a targeted examination should be carried out in time to confirm the diagnosis and give appropriate treatment.

Short-Term Outcomes and Risk Factors of In-Hospital Mortality in Patients Suffering Acute Mesenteric Ischemia after Cardiac Surgery: Role of Opioids and Lactic Acid

Acute mesenteric ischemia (AMI) is associated with poor clinical results after cardiac surgery. The aim of this study was to analyse the influence of AMI on short-term outcomes and all relevant risk factors of in-hospital mortality after cardiac surgery. Moreover, we aimed to investigate the role of opioids and lactic acid in the detection and prevention of AMI. Between August 2011 and September 2015, 176 consecutive patients with gastrointestinal complications after undergoing open-heart surgery were identified and included in this study. All patients were divided into two groups: AMI group (n = 39) and non-AMI group (n = 137). In terms of comorbidities, the groups were fairly equal and showed no significant differences. Dialysis was significantly higher (p < 0.001) in patients that suffered from AMI. Moreover, gastro-intestinal symptoms such as muscular defense (p = 0.004) and the laparotomy rate (p < 0.001) were significantly higher in the AMI group. Likewise, in-hospital mortality (p < 0.001) was significantly higher in patients with detected AMI. Univariate (p < 0.001) and multivariate analysis (p = 0.025) of both groups revealed that lactic acid value >2 mmol/L and present treatment with opioids are independent combined predictors of mesenteric ischemia in patients after undergoing cardiac surgery. Moreover, multivariate analysis showed peripheral vascular disease (p = 0.004), dialysis (p = 0.010), and septic shock (p = 0.003) as relevant predictors of in-hospital mortality. Prolonged analgetic treatment with opioids and sudden increase of lactic acid levels are independent combined predictors of mesenteric ischemia in patients after undergoing cardiac surgery. Furthermore, peripheral vascular disease, dialysis, and septic shock are relevant predictors for in-hospital mortality.

Gastrointestinal Ultrasound in Emergency Setting

Acute bowel diseases are responsible for more than one third of subjects who were referred to the emergency department for acute abdominal pain and gastrointestinal evaluation. Gastrointestinal ultrasound (GIUS) is often employed as the first imaging method, with a good diagnostic accuracy in the setting of acute abdomen, and it can be an optimal diagnostic strategy in young females due to the radiation exposure related to X-ray and computed tomography methods. The physician can examine the gastrointestinal system in the area with the greatest tenderness by ultrasound, thus obtaining more information and data on the pathology than the standard physical examination. In this comprehensive review, we have reported the most relevant indications and advantages to using ultrasound in the investigation of abdominal acute pain.

Epidemiology of Acute Mesenteric Ischemia: A Population-Based Investigation

BACKGROUND

There is a lack of population-based studies on acute mesenteric ischemia (AMI). We have therefore performed a nationwide epidemiological study in Estonia, addressing incidence, demographics, interventions and mortality of AMI.

METHODS

A retrospective population-based review was conducted of all adult cases of AMI accrued from the digital Estonian Health Insurance Fund and Causes of Death Registry for 2016-2020 based on international classification of diseases (ICD-10) diagnostic codes and procedure codes (NOMESCO).

RESULTS

Overall, 577 cases of AMI were identified-an annual incidence of 8.7 per 100,000. The median age was 79 (range 32-104) and 57% were female. Predominating comorbidities included hypertensive disease (81%), atherosclerosis (67%), and atrial fibrillation (52%). The majority of cases (60%) were caused by superior mesenteric artery occlusion (thrombosis 54%, embolism 12%, and unclear 34%). Inferior mesenteric artery occlusion occurred in 7%, non-occlusive mesenteric ischemia in 7%, venous thrombosis in 4%, whereas the type remained unclear in 21% of cases. 40% of patients received intervention (revascularization and/or intestinal resection) and 13% active non-operative treatment. In 21% an exploratory laparotomy or laparoscopy revealed unsalvageable bowel prompting end-of-life care, which was the only management in a further 25% of cases.

CONCLUSIONS

The population-based annual incidence of AMI in Estonia was 8.7 per 100,000 during the study period. The overall hospital mortality and 1 year mortality were 64% and 74%, respectively. In the 53% of patients who received active treatment hospital mortality was 32% and 1 year all-cause mortality was 51%.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier NCT04867499.

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.

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.

Case report: Non-occlusive mesenteric ischemia in the setting of sildenafil use

Acute mesenteric ischemia (AMI) is a condition that results from a sudden decline in blood flow through the mesenteric vessels that has a high morbidity and mortality. Non-occlusive AMI often presents in critically ill, hypotensive patients that suffer from decreased organ perfusion. Here we describe a case of non-occlusive acute mesenteric ischemia in the setting of transient hypotension precipitated by sildenafil. The patient required rapid fluid resuscitation in the emergency department. He did not require surgical intervention and was able to be discharged home with resolution of symptoms after a 7-day inpatient stay.

Association of Serum Creatinine Level with Prognosis of Laparotomy for Acute Mesenteric Ischemia after Cardiovascular Surgery

Introduction

Acute mesenteric ischemia is a life-threatening complication after cardiovascular surgery with a mortality rate of 52.9–81.3%. However, few studies have evaluated the predictors of clinical outcome after treatment for acute mesenteric ischemia following cardiovascular surgery. Therefore, this study aimed to elucidate prognostic factors in patients who underwent laparotomy for acute mesenteric ischemia after cardiovascular surgery.

Methods

We retrospectively analyzed 29 patients (20 men and 9 women; median age, 71.0 years) who underwent laparotomy for acute mesenteric ischemia after cardiovascular surgery between January 2010 and August 2020. These patients were classified into the survivor group (comprising patients who were discharged or referred to another hospital, n = 16) and the nonsurvivor group (comprising those who experienced in-hospital mortality, n = 13). We compared clinical parameters between the groups to identify the predictors of outcomes.

Results

More patients in the nonsurvivor group underwent emergency cardiovascular surgery (62.5% vs. 100%, p = 0.017) and received hemodialysis (12.5% vs. 61.5%, p = 0.008) at the onset of acute mesenteric ischemia than those in the survivor group. The prelaparotomy serum creatinine level was higher in the nonsurvivor group than in the survivor group (1.27 vs. 2.33 mg/dL, p = 0.004). Logistic regression analysis revealed an association between preoperative serum creatinine level and in-hospital mortality (odds ratio 5.047, p = 0.046), and Cox regression analysis demonstrated a relationship between serum creatinine level and in-hospital mortality (hazard ratio 1.610, p = 0.009). The area under the curve (receiver operating characteristic analysis) for the serum creatinine level was 0.813. Furthermore, the optimal cutoff value of the serum creatinine level was 1.59 mg/dL with a sensitivity and specificity of 0.846 and 0.687, respectively, in predicting in-hospital mortality.

Conclusions

The elevated serum creatinine level was associated with a poor clinical outcome after surgery for acute mesenteric ischemia following cardiovascular surgery.

Abdominal Ischemia-Reperfusion Induced Cardiac Dysfunction Can Be Prevented by MitoTEMPO

BACKGROUND

Cardiac dysfunction is secondary to acute mesenteric ischemia (AMI) and abdominal aortic aneurysms (AAA). The underlying cause of distant organ damage in the heart is the formation of oxidative stress caused by ischemia-reperfusion. In this study, we investigated the possible protective effects of a novel mitochondria-targeted antioxidant MitoTEMPO on contractile dysfunction and structural defects of the rat papillary muscle caused by abdominal ischemia-reperfusion (AIR).

METHODS AND RESULTS

In the experiments, adult Wistar-Albino rats were used and animals were divided randomly into 3 groups; sham-operated group (SHAM), an IR group that had aortic cross-clamping for 1 h followed by 2 h reperfusion, and a third group that received protective 0.7 mg/kg/day MitoTEMPO injection for 28-day before IR. As a result, it was observed that MitoTEMPO injection had a protective effect on the mechanical activities and structural properties of the papillary muscle impaired by AIR. Our study also showed that AIR disrupted the contractile function of the papillary muscle for each stimulation frequency and post-potentiation responses tested. This is common for each measured and calculated mechanical parameter and MitoTEMPO injection showed its protective effects.

CONCLUSION

Consequently, calcium homeostasis seems to be impaired by AIR, and MitoTEMPO may exert its protective effect through energy metabolism by directly targeting the mitochondria.

The Prognostic Value of C-Reactive Protein/Albumin Ratio in Acute Mesenteric Ischemia

Background

Diagnosis of acute mesenteric ischemia (AMI) in its early stages is important for reversing ischemic damage. The CRP to albumin (CRP/Alb) ratio has been defined as an inflammatory indicator and is associated with the severity of inflammation and mortality rates. However, the prognostic value of CRP/Alb has not been evaluated in patients with AMI. Here, we aimed to examine the prognostic significance of CRP/Alb and compare it with other inflammatory markers.

Materials and Methods

In this retrospective, case-control study, we included patients diagnosed with AMI at the emergency department between January 1, 2016, and December 31, 2020. In addition to demographic characteristics, lactate, D-dimer, white blood cell (WBC), CRP/Alb, and neutrophil/lymphocyte ratio (NLR) were recorded. Testing characteristics of CRP/Alb in predicting in-hospital mortality were studied.

Results

The mean age of 132 patients was 66.48 ± 15.95 years and 71 (53.8%) of them were male. The cut-off value obtained using the receiver operating characteristic (ROC) curve for in-hospital mortality was a CRP/Alb ratio of >1.32 (sensitivity, 93.65%; specificity, 69.57%; +LR, 3.08; −LR, .091; AUC, .782; 95% CI, .70-.85; P < .0001). The comparison of ROC curves between CRP/Alb and WBC, NLR, and lactate revealed a statistically significant difference ( P < .05), whereas there was not any statistically significant difference between the ROC curves of CRP/Alb and D-dimer ( P = .47).

Conclusion

C-reactive protein/albumin ratio is a powerful predictor of in-hospital mortality for AMI patients. It was superior to WBC, NLR, and lactate. It could be used to determine low-risk patients and help clinicians with treatment options.

Endovascular Revascularization as Primary Treatment for Acute Embolic Mesenteric Ischemia: Stent Thrombectomy plus Aspiration versus Aspiration Alone

OBJECTIVE

This study aimed to investigate the outcomes of stent thrombectomy combined with aspiration versus aspiration alone in acute mesenteric ischemia (AMI).

METHODS

This was a single-center, retrospective cohort study. Between 1 May 2012 and 1 January 2021, 41 patients (mean age, 73.8±7.9 years) with AMI who underwent stent thrombectomy plus aspiration (Group 1, n=14) or aspiration alone (Group 2, n=27) were included. Patients' treatment regimens, clinical and follow-up outcomes were reviewed and analyzed. The group differences were compared using a Chi square test, Fisher's exact test, independent t test, or Mann-Whitney U test. The cumulative survival rate was calculated using a Kaplan-Meier curve.

RESULTS

The overall clinical success rate was 78.0% (32/41), and no significant difference was found between Group 1 and Group 2 (78.6% vs. 77.8%, p = 1.00). Whereas Group 1 was associated with a higher complete clearance rate (78.6% vs. 44.4%, p = 0.04), less adjunctive local thrombolysis (14.3% vs. 48.1%, p = 0.03), and shorter length of hospital stay (5.7±4.7 vs. 10.7±9.0 days, p = 0.03). The estimated survival rate at 1 month, 3 months, 6 months, 1 year, and 2 years was 73.2%, 72.5%, 71.4%, 65.3%, and 59.8%, respectively. No significant difference was found in survival rate between the groups (log-rank, p = 0.96). The recurrence rate for Group 1 and Group 2 were 8.3% (1/12) and 4.0% (1/25), respectively.

CONCLUSIONS

Compared with aspiration alone, additional stent thrombectomy showed superiorities in higher complete clearance rate, reduced adjunctive thrombolysis, and shorter length of hospital stay.

Ischemic bowel disease in 2021

Ischemic bowel disease (ISBODI) includes colon ischemia, acute mesenteric ischemia (AMI) and chronic mesenteric ischemia (CMI). Epidemiologically, colon ischemia is the most common type followed by AMI and CMI. There are various risk factors for the development of ISBODI. Abdominal pain is the common presenting symptom of each type. High clinical suspicion is essential in ordering appropriate tests. Imaging studies and colonoscopy with biopsy are the main diagnostic tests. Treatment varies from conservative measures to surgical resection and revascularization. Involvement of multidisciplinary team is essential in managing ISBODI. Although open surgery with revascularization plays an important role, recently there is an increasing interest in percutaneous endovascular treatment.

Concealed mesenteric ischemia after total knee arthroplasty: A case report

BACKGROUND

In critical care medicine, mesenteric ischemia (MI) is a life-threatening disease that can be present in both critically ill patients and those undergoing major surgery. For the first time, we report a case of concealed MI with a long course after knee arthroplasty.

CASE SUMMARY

A male patient underwent left total knee arthroplasty for gouty arthritis and developed a persistent fever and persistently high levels of serum infection markers after surgery. He was considered to have a periprosthetic site infection and treated with antibiotics and colchicine, periprosthetic debridement was performed, and the spacer was replaced, but no improvement was seen. At 54 d after arthroplasty, the patient developed gastrointestinal symptoms of nausea and vomiting, abdominal distention, and subsequently, cloudiness of consciousness, and hypotensive shock. Finally, the patient was diagnosed with ascending colonic mesentery ischemia with necrosis after laparotomy, which improved after right hemicolectomy.

CONCLUSION

Concealed MI without gastrointestinal symptoms after major surgery is rare and easily misdiagnosed. Orthopedic surgeons need to be aware of this complication.

Vasoactive agents in acute mesenteric ischaemia in critical care. A systematic review

Background: Acute mesenteric ischaemia (AMI) is a surgical emergency which has an associated high mortality.  The mainstay of active treatment includes early surgical intervention, with resection of non-viable bowel, and revascularisation of the ischaemic bowel where possible. Due to the physiological insult of AMI however, perioperative care often involves critical care and the use of vasoactive agents to optimise end organ perfusion. A number of these vasoactive agents are currently available with varied mechanism of action and effects on splanchnic blood flow. However, specific guidance on which is the optimal vasoactive drug to use in these settings is limited. This systematic review aimed to evaluate the current evidence comparing vasoactive drugs in AMI. Methods: A systematic search of Ovid Medline, Ovid Embase, Cochrane CENTRAL and the Cochrane Database of Systematic Review was performed on the 5th of November 2020 to identify randomised clinical trials comparing different vasoactive agents in AMI on outcomes including mortality. The search was performed through the Royal College of Surgeons of England (RCSEng) search support library. Results were analysed using the Rayyan platform, and independently screened by four investigators. Results: 614 distinct papers were identified. After screening, there were no randomised clinical trials meeting the inclusion criteria. Conclusions: This review identifies a gap in literature, and therefore recommends an investigation into current practice and clinician preference in relation to vasoactive agents in AMI. Multicentre randomised controlled trials comparing these medications on clinical outcomes will therefore be required to address this question.

Vasoactive agents in acute mesenteric ischaemia in critical care. A systematic review

Background: Acute mesenteric ischaemia (AMI) is a surgical emergency which has an associated high mortality.  The mainstay of active treatment includes early surgical intervention, with resection of non-viable bowel, and revascularisation of the ischaemic bowel where possible. Due to the physiological insult of AMI however, perioperative care often involves critical care and the use of vasoactive agents to optimise end organ perfusion. A number of these vasoactive agents are currently available with varied mechanism of action and effects on splanchnic blood flow. However, specific guidance on which is the optimal vasoactive drug to use in these settings is limited. This systematic review aimed to evaluate the current evidence comparing vasoactive drugs in AMI. Methods: A systematic search of Ovid Medline, Ovid Embase, Cochrane CENTRAL and the Cochrane Database of Systematic Review was performed on the 5th of November 2020 to identify randomised clinical trials comparing different vasoactive agents in AMI on outcomes including mortality. The search was performed through the Royal College of Surgeons of England (RCSEng) search support library. Results were analysed using the Rayyan platform, and independently screened by four investigators. Results: 614 distinct papers were identified. After screening, there were no randomised clinical trials meeting the inclusion criteria. Conclusions: This review identifies a gap in literature, and therefore recommends an investigation into current practice and clinician preference in relation to vasoactive agents in AMI. Multicentre randomised controlled trials comparing these medications on clinical outcomes will therefore be required to address this question.

Early Surgical Intervention Improves Survival in Acute Intestinal Ischemia in the Intensive Care Unit

The study is aimed at assessing whether the early surgical intervention improves survival in acute mesenteric ischemia with septic shock. A retrospective study design was applied to review the charts of patients admitted to the intensive care unit. The data were collected through a review of the full patient chart including physician and nursing notes, pathology reports, intraoperative findings, CT findings, and endoscopy. The diagnosis of AMI for each patient was determined through clinical presentation/endoscopic visualization/laboratory results/radiographic imaging, surgical exam (tissue or visual) and/or autopsy. Death and survival were evaluated between short and long-time-interval for septic shock groups using the chi-square test followed by calculating the P value. Total survival among the surgery group was 60 patients (95.24%) compared to 3 (4.76%) survival among patients who did not have surgery. The time from the onset of a shock to the time of surgical incision was calculated. The mean time to surgery was 17.7 hours. Total 65 patients (29.52%) had surgery between 4 and 12 hours from the onset of hypotension. Survivals among this group of patients were 41.7% (n = 25). The survival difference was statistically significant than died patients with respect to the time of surgical intervention (P = <0.001). Early removal of ischemic bowel in patients with AII-related surgery has improved survival.

Anti-inflammatory and antioxidant effects of the nanocomposite Fullerol decrease the severity of intestinal inflammation induced by gut ischemia and reperfusion

Intestinal ischemia is a vascular emergency that arises when blood flow to the intestine is compromised. Reperfusion is necessary to restore intestinal function but might lead to local and systemic inflammatory responses and bacterial translocation, with consequent multiple organ dysfunction syndrome (MODS). During reperfusion occurs production of reactive oxygen species. These species contribute to intestinal injury through direct toxicity or activation of inflammatory pathways. Fullerol is a nanacomposite which has been shown to act as reactive oxygen species and reactive nitrogen species (RNS) scavengers. Thus, our aim was to evaluate whether Fullerol confer anti-inflammatory activity during intestinal ischemia and reperfusion (IIR). Intestinal ischemia was induced by total occlusion of the superior mesenteric artery. Groups were treated with vehicle or Fullerol 10 min before reperfusion. Mice were euthanized after 6 h of reperfusion, and small intestines were collected for evaluation of plasma extravasation, leukocyte influx, cytokine production and histological damage. Bacterial translocation to the peritoneal cavity and reactive oxygen and nitrogen species production by lamina propria cells were also evaluated. Our results showed that treatment with Fullerol inhibited bacterial translocation to the peritoneal cavity, delayed and decreased the lethality rates and diminished neutrophil influx and intestinal injury induced by IIR. Reduced severity of reperfusion injury in Fullerol-treated mice was associated with blunted reactive oxygen and nitrogen species production in leukocytes isolated from gut lamina propria and decreased production of pro-inflammatory mediators. Thus, the present study shows that Fullerol is a potential therapy to treat inflammatory bowel disorders associated with bacterial translocation, such as IIR.

Many faces of acute bowel ischemia: overview of radiologic staging

Acute bowel ischemia (ABI) can be life threatening with high mortality rate. In spite of the advances made in diagnosis and treatment of ABI, no significant change has occurred in the mortality over the past decade. ABI is potentially reversible with prompt diagnosis. The radiologist plays a central role in the initial diagnosis and preventing progression to irreversible intestinal ischemic injury or bowel necrosis. The most single imaging findings described in the literature are either non-specific or only present in the late stages of ABI, urging the use of a constellation of features to reach a more confident diagnosis. While ABI has been traditionally categorized based on the etiology with a wide spectrum of imaging findings overlapped with each other, the final decision for patient’s management is usually made on the stage of the ABI with respect to the underlying pathophysiology. In this review, we first discuss the pathologic stages of ischemia and then summarize the various imaging signs and causes of ABI. We also emphasize on the correlation of imaging findings and pathological staging of the disease. Finally, a management approach is proposed using combined clinical and radiological findings to determine whether the patient may benefit from surgery or not.

A clinical approach to acute mesenteric ischemia

PURPOSE OF REVIEW

To summarize current evidence on acute mesenteric ischemia (AMI) in critically ill patients, addressing pathophysiology, definition, diagnosis and management.

RECENT FINDINGS

A few recent studies showed that a multidiscipliary approach in specialized centers can improve the outcome of AMI. Such approach incorporates current knowledge in pathophysiology, early diagnosis with triphasic computed tomography (CT)-angiography, immediate endovascular or surgical restoration of mesenteric perfusion, and damage control surgery if transmural bowel infarction is present. No specific biomarkers are available to detect early mucosal injury in clinical setting. Nonocclusive mesenteric ischemia presents particular challenges, as the diagnosis based on CT-findings as well as vascular management is more difficult; some recent evidence suggests a possible role of potentially treatable stenosis of superior mesenteric artery and beneficial effect of vasodilator therapy (intravenous or local intra-arterial). Medical management of AMI is supportive, including aiming of euvolemia and balanced systemic oxygen demand/delivery. Enteral nutrition should be withheld during ongoing ischemia-reperfusion injury and be started at low rate after revascularization of the (remaining) bowel is convincingly achieved.

SUMMARY

Clinical suspicion leading to tri-phasic CT-angiography is a mainstay for diagnosis. Diagnosis of nonocclusive mesenteric ischemia and early intestinal injury remains challenging. Multidisciplinary team effort may improve the outcome of AMI.

[Is acute mesenteric ischemia incurable situation? The current state of the problem]

Mortality rates in acute mesenteric ischemia remain at an extremely high level for many decades. Early diagnosis and selection of the optimal method of revascularization are among the ways to optimize tactics. The diagnostic study of choice is CT angiography. Its active and systemic use can help to detect ischemia at the reversible stage. The article examines in detail the indications for the application of this diagnostic study. The question of preference for the revascularization method remains debatable. The arguments of proponents of open and endovascular interventions on mesenteric vessels are presented. Other, still unresolved tactical issues are also considered, such as indications for re-operations and application of the principles of damage control tactics.

Protective Effects of Cinnamaldehyde against Mesenteric Ischemia-Reperfusion-Induced Lung and Liver Injuries in Rats

The aim of this study was to characterize and reveal the protective effects of cinnamaldehyde (CA) against mesenteric ischemia-reperfusion- (I/R-) induced lung and liver injuries and the related mechanisms. Sprague-Dawley (SPD) rats were pretreated for three days with 10 or 40 mg/kg/d, ig of CA, and then induced with mesenteric ischemia for 1 h and reperfusion for 2 h. The results indicated that pretreatment with 10 or 40 mg/kg of CA attenuated morphological damage in both lung and liver tissues of mesenteric I/R-injured rats. CA pretreatment significantly restored the levels of aspartate transaminase (AST) and alanine transaminase (ALT) in mesenteric I/R-injured liver tissues, indicating the improvement of hepatic function. CA also significantly attenuated the inflammation via reducing myeloperoxidase (MOP) activity and downregulating the expression of inflammation-related proteins, including interleukin-6 (IL-6), interleukin-1β (IL-1β), cyclooxygenase-2 (Cox-2), and tumor necrosis factor receptor type-2 (TNFR-2) in both lung and liver tissues of mesenteric I/R-injured rats. Pretreatment with CA significantly downregulated nuclear factor kappa B- (NF-κB-) related protein expressions (NF-κB p65, NF-κB p50, I kappa B alpha (IK-α), and inhibitor of nuclear factor kappa-B kinase subunit beta (IKKβ)) in both lung and liver tissues of mesenteric I/R-injured rats. CA also significantly downregulated the protein expression of p53 family members, including caspase-3, caspase-9, Bax, and p53, and restored Bcl-2 in both lung and liver tissues of mesenteric I/R-injured rats. CA pretreatment significantly reduced TUNEL-apoptotic cells and significantly inhibited p53 and NF-κB p65 nuclear translocation in both lung and liver tissues of mesenteric I/R-injured rats. CA neither induced pulmonary and hepatic histological alterations nor affected the parameters of inflammation and apoptosis in sham rats. We conclude that CA alleviated mesenteric I/R-induced pulmonary and hepatic injuries via attenuating apoptosis and inflammation through inhibition of NF-κB and p53 pathways in rats, suggesting the potential role of CA in remote organ ischemic injury protection.

Gastrointestinal Ultrasound (GIUS) in Intestinal Emergencies - An EFSUMB Position Paper

An interdisciplinary group of European experts summarizes the value of gastrointestinal ultrasound (GIUS) in the management of three time-critical causes of acute abdomen: bowel obstruction, gastrointestinal perforation and acute ischemic bowel disease. Based on an extensive literature review, statements for a targeted diagnostic strategy in these intestinal emergencies are presented. GIUS is best established in case of small bowel obstruction. Metanalyses and prospective studies showed a sensitivity and specificity comparable to that of computed tomography (CT) and superior to plain X-ray. GIUS may save time and radiation exposure and has the advantage of displaying bowel function directly. Gastrointestinal perforation is more challenging for less experienced investigators. Although GIUS in experienced hands has a relatively high sensitivity to establish a correct diagnosis, CT is the most sensitive method in this situation. The spectrum of intestinal ischemia ranges from self-limited ischemic colitis to fatal intestinal infarction. In acute arterial mesenteric ischemia, GIUS may provide information, but prompt CT angiography is the gold standard. On the other end of the spectrum, ischemic colitis shows typical ultrasound features that allow correct diagnosis. GIUS here has a diagnostic performance similar to CT and helps to differentiate mild from severe ischemic colitis.

Risk Factors Associated with In-Hospital Mortality for Patients with Acute Abdomen After Cardiac Surgery

OBJECTIVES

Management of acute abdomen (AA) differs due to the heterogeneity of underlying pathophysiology. Complications of AA and its overall outcome after cardiac surgery are known to be associated with poor results. The aim of this retrospective analysis was to evaluate risk factors for AA in patients undergoing cardiac surgery.

METHODS

Between December 2011 and December 2014, a total of 131 patients with AA after cardiac surgery were identified and retrospectively analyzed using our institutional database. Statistical analysis of risk factors concerning in-hospital mortality of mentioned patient cohort was performed using IBM SPSS Statistics.

RESULTS

Overall in-hospital mortality was 54.2% (71/131). Analyzing in-hospital non-survivors (NS) versus in-hospital survivors (S) peripheral artery disease (28.2% vs. 11.7%; p = 0.03), the need for assist device therapy (33.8% vs. 16.7%; p = 0.03) and the requirement of hemodialysis (67.6% vs. 23.3%; p < 0.01) were significantly higher in NS. Furthermore, lactic acid values at onset of symptoms were shown to be significantly higher in NS (5.7 ± 5.7 mmol/L vs. 2.8 ± 2.9 mmol/L; p < 0.01). Assured diagnosis of mesenterial ischemia was strongly associated with worse outcome (odds ratio 10.800, 95% confidence interval 2.003-58.224; p = 0.006).

CONCLUSION

In conclusion, in critically ill patients after performed cardiac surgery peripheral vascular disease, need for supportive hemodynamic assist device systems and occurrence of renal failure are risk factors associated with worsen outcome. Additionally, rise of lactic acid could potentially be associated with onset of intestinal malperfusion and should be taken into account in therapeutic decisions preventing fatal mesenterial ischemia.

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.

Abdominal Surgery in Patients with Ventricular Assist Devices: a Single-Center Report

This study was performed to evaluate the incidence and outcome of patients with ventricular assist devices (VADs) undergoing abdominal surgery at our institution. A total of 604 adult patients who underwent VAD implantation between February 2004 and February 2018 were analyzed retrospectively with a median follow-up time of 66 (6-174) months. Thirty-nine patients (6.5%) underwent abdominal surgery. Elective surgical procedures were performed in 22 patients (56.4%), mainly for abdominal wall hernia repairs, partial colectomies, and cholecystectomies. Early after elective abdominal surgery no patient died, resulting in a median survival of 23 (1-78) months. Emergency surgery was performed in 17 patients (43.6%). The most common emergency indications were intestinal ischemia and/or perforation. Eight patients undergoing emergent surgery (44.4%) died within the first 30 days after primary abdominal operation, mainly due to sepsis and consecutive multiple organ failure, resulting in a dismal median survival of one month (0-52). Patients undergoing abdominal surgery had significantly lower rates of realized heart-transplantation (p = 0.031) and a significantly higher rate of VAD exchange, before or after abdominal surgery, due to thromboses or infections (p = 0.037). Nonetheless, overall survival after primary VAD implantation in these patients (median 38 months; 0-107) was not significantly impaired when compared to all other patients undergoing VAD implantation (median 30 months; 0-171). In summary, elective abdominal surgery can be performed safely when well planned by an experienced multidisciplinary team. Abdominal complications in VAD patients requiring emergent surgery, however, lead to a significant increase in short-term morbidity and a high 30-day mortality rate.

Guideline for Management of Mesenteric Ischemia: Shiraz Intestinal Failure Unit Protocol

We have recently established an intestinal rehabilitation unit (IRU) in Abu Ali Sina transplantation center affiliated to Shiraz University of Medical Sciences, Iran. Our intestinal failure rehabilitation and transplant program aims to provide state-of-the-art care for adult patients with different degrees of intestinal insufficiency and failure. In the IRU, we aimed to design an algorithmic approach to patients with small bowel ischemia and short bowel syndrome (SBS) based on our institutional experience in our country and based on other pioneering studies from other regions of the world.

Large-scale epidemiological data on vascular disorders of the intestine

Objectives: This article aims to provide updates on the worldwide epidemiology of vascular disorders of the intestine.Methods: A comprehensive search for obtaining worldwide epidemiologic information on the burden of vascular disorders of the intestine was carried out in the Global Health Data Exchange (GHDx) repository. The condition 'vascular intestinal disorders' was associated with other epidemiologic variables such as year, sex, age, location and socioeconomic status.Results: The current global incidence and mortality of vascular disorders of the intestine are 8.11 per 100,000 cases/year and 1.26 per 100,000 deaths/year, respectively, translating into a death rate of 15.5%. Both global incidence and mortality are 32% higher in the female sex and have both displayed a continuous increase during the past 20 years (+29.3% and +18.4% since 1998, respectively). Incidence and mortality curves appear similar between sexes, with the incidence increasing after the age of 40 years and mortality after the age of 50 years, respectively. The peak of both worldwide incidence and mortality was seen in very elderly people. The death rate increased in parallel with incidence and mortality, from ∼1% to 3% in childhood up to ∼50% after the age of 95 years. Both incidence and mortality displayed a positive association with socioeconomic status. Future projections suggest that incidence and mortality will display 44% and 24% growths by the year 2050.Conclusions: Our analysis demonstrates that the clinical and societal burden of vascular disorders of the intestine is especially higher in women, in the elderly and in people with higher socioeconomic status.

Review Article: Mesenteric Ischemia

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

Acute Mesenteric Ischemia Remains a Highly Morbid Diagnosis after Initial Hospitalization Survival

Acute mesenteric ischemia (AMI) remains a vascular emergency. Our aim was to explore readmission for AMI. We identified all patients admitted for AMI from the state of California through the Healthcare and Utilization Project from 2005 to 2011. Our primary end point was the rate and etiology for readmission. Our secondary end points were the length of hospitalization and in-hospital mortality. Cox proportional hazard regression was utilized to assess risk of 30-day readmission. There were 534 (9.9%) readmissions at 30 days. The mean age was 67 ± 17 years and 209 (39.1%) were male. The five most common etiologies for readmission were AMI (7.6%), cardiac events (5.3%), severe sepsis (1.2%), dehydration (1.1%), and acute kidney failure (1.1%). Once readmitted, these patients were most likely to experience cardiac catheterizations (25.4%), red blood cell transfusions (23.6%), intubation and mechanical ventilation (17.6%), biopsy of the large intestine (13.9%), reoperation for small bowel resection (10.9%), administration of total parenteral nutrition (10.5%), and transfusion of other blood products (6.9%). This hospitalization was 8.8 ± 12.7 days long. In-hospital mortality was 36 patients (6.7%). On multivariable Cox-regression analysis, severe (hazard ratio [HR]: 2.1 [1.4-3.2], p  = 0.0005) and moderate (HR: 1.5 [1.03-2.13], p  = 0.04) Elixhauser Comorbidity Group, complications (HR: 1.5 [1.2-1.9], p  = 0.0007), and longer index hospitalization (HR: 1.02 [1.01-1.02], p  < 0.0001) were predictors of readmission. Conclusion  AMI remains a vascular emergency. Readmissions have a significant rate of morbid invasive procedures and can lead to an in-hospital mortality of 6.7%. The adoption of guidelines similar to the European Society for Trauma and Emergency Surgery should be considered.