Risk factor analysis for nonocclusive mesenteric ischemia following cardiac surgery: A case-control study

Diagnosis and management of acute mesenteric ischemia: What you need to know

ABSTRACT

Acute mesenteric ischemia (AMI) is associated with high mortality rates. There are multiple challenges to establishing an accurate early diagnosis and providing state-of-the-art care for AMI patients. A high index of suspicion is key for early diagnosis. Once suspicion is raised, a triphasic computed tomography angiography is the essential diagnostic tool. Avoiding delays, using hybrid operating rooms and contemporary revascularization techniques for arterial occlusive AMI, can significantly improve the prognosis. Regional health care systems should be developed to direct AMI patients into centers with sufficient capabilities for providing all aspects of care at all hours. The acute care surgeon has a central role in performing laparotomies and bowel resections when needed and coordinating the management flow in close collaboration with vascular surgeons and interventional radiologists for prompt and effective revascularization. A significant share of patients with an arterial occlusive AMI can be managed by endovascular revascularization without the need for a laparotomy. There are no reliable tools for predicting transmural bowel necrosis, and individual assessment and clinical experience are very important in decision-making when choosing between laparotomy and close observation. During laparotomy, an atherosclerotic occlusion at the root of the superior mesenteric artery can be stented by using a retrograde open mesenteric or percutaneous approach, and surgical bypass is seldom needed. Using hospital-specific management pathways is very useful for the standardization of care in arterial occlusive AMI. In venous AMI, systemic anticoagulation is sufficient in most cases. In patients whose symptoms do not resolve, there are various options for endovascular and surgical revascularization. In nonocclusive mesenteric ischemia, prevention by maintaining sufficient abdominal perfusion pressure is key. High-level evidence is scarce, but with current knowledge, the prognosis of AMI patients has plenty of room for improvement.

Treatment outcomes in non-occlusive mesenteric ischemia and post-treatment return to social activities

PURPOSE

To investigate the treatment outcomes of patients with non-occlusive mesenteric ischemia (NOMI) at our institution, we focused on their post-treatment return to social activities.

METHODS

This study included patients with suspected NOMI who were referred to our department between 2011 and 2023. In-hospital mortality was also investigated as a prognostic factor. The Glasgow-Pittsburgh Outcome Categories (GPOC) score was used to evaluate the return to social activities. The relationship between in-hospital mortality and GPOC scores and patient background and treatment factors was examined.

RESULTS

Eighty-two patients were included in the study. Among them, 54 (65.9%) died during hospitalization. Only 9 patients (11%) returned to their social activities. In the multivariate analysis, non-surgical management was found to be the only independent factor for in-hospital mortality. Positive portal venous gas on computed tomography, no open abdomen, no pre-onset catecholamine administration, platelet count < 100,000/µL, lactate level < 5 mmol/L, APTT < 46 s, and Sequential Organ Failure Assessment score < 11 were factors significantly associated with an increased likelihood of return to social activities.

CONCLUSION

This is the first study to assess the post-treatment return to social activities among patients with NOMI. Our findings highlight the concerning reality that survivors may face prolonged dependence on medical care.

Non-occlusive Mesenteric Ischemia Following Severe Traumatic Brain Injury: A Case Report

Although various risks associated with non-occlusive mesenteric ischemia (NOMI) have been reported, to the best of our knowledge, no report has suggested an association between severe traumatic brain injury (sTBI) and NOMI. We experienced a case of NOMI in a young woman with no risk except sTBI. A passerby discovered an unresponsive woman lying on the street and summoned emergency medical services. The woman was subsequently transported to our emergency department by ambulance. The patient was diagnosed with sTBI and underwent emergency craniotomy on the same day. After surgery, she was placed under general management in the intensive care unit (ICU). She was discharged from the ICU on postoperative day 9. On postoperative 14, she experienced sudden cardiac arrest. Based on clinical findings, cardiac arrest in this case was attributed to hypoxia due to aspiration caused by abdominal distension and vomiting following the onset of NOMI. This case report suggests that sTBI may be a risk factor for the development of NOMI.

Vasopressor-Inotropic Score: Review of Literature

Patients undergoing cardiac surgery often receive vasopressor and inotropic medications during the surgical procedure and during intensive care unit (ICU) management following surgery. Patients with cardiogenic shock, septic shock, and other clinical disorders associated with shock also receive vasopressor medications during their ICU care. The level of support and the duration of support are likely associated with outcomes, including mortality and new organ dysfunction, such as acute kidney injury. The vasopressor-inotropic score provides a simple method to determine the level of support during the care of these patients; this score includes the infusion rates of norepinephrine, epinephrine, dopamine, dobutamine, and other inotropic medications. It has been studied in patients undergoing cardiac surgery, coronary artery bypass grafting, cardiac transplantation, left ventricular assist device implantation, septic shock, and traumatic brain injury. Higher scores are associated with poor outcomes and complications during ICU care. The studies analyzed in this review demonstrate the utility of the vasopressor-inotropic score in a variety of clinical disorders associated with shock. Electronic medical record systems should develop algorithms to calculate this score and provide continuous up-to-date measurements. This could help clinicians identify patients at risk for mortality and important complications, such as acute kidney injury.

Intestinal Fatty Acid Binding Protein as a Predictor of Early Mesenteric Injury Preceding Clinical Presentation: A Case Report

Introduction

Diagnosing non-occlusive mesenteric ischaemia (NOMI) in patients is complicated, due to poor signs and symptoms and non-specific laboratory tests, leading to a high mortality rate. This case study presents the rare case of a patient who developed mesenteric ischaemia after an emergency thoracic endovascular aneurysm repair (TEVAR) for a type B aortic dissection (TBAD) and peri-operative cardiogenic shock. Study outcomes revealed that intestinal fatty acid binding protein (I-FABP) identified early mucosal damage two days before the clinical presentation.

Report

A 43 year old male patient was admitted to the emergency department with an acute TBAD and a dissection of the superior mesenteric artery (SMA), for which TEVAR was performed with additional stent placement in the SMA. Peri-operatively, the patient went into cardiogenic shock with a sustained period of hypotension. Post-operatively, the plasma I-FABP levels were measured prospectively, revealing an initial increase on post-operative day five (551.1 pg/mL), which continued beyond day six (610.3 pg/mL). On post-operative day seven, the patient developed a fever and demonstrated signs of peritonitis and bowel perforation. He underwent an emergency laparotomy, followed by an ileocaecal resection (<100 cm) with a transverse ileostomy. Pathological analysis confirmed the diagnosis of mesenteric ischaemia.

Discussion

The diagnosis of NOMI in critically ill patients is often complicated, and the currently available diagnostic markers lack the specificity and sensitivity to detect early intestinal injury. This case report highlights that elevated I-FABP in plasma levels may indicate the presence of early mesenteric injury. Further research needs to be conducted before I-FABP can be applied in daily practice.

Gastrointestinal complications after cardiac surgery

Gastrointestinal complications after cardiac surgery are relatively rare entities but carry a high mortality. We identified over 70 articles written since 2010 using the PubMed database. We included 40 in our review. The most common complications include paralytic ileus, gastrointestinal bleeding, and bowel ischemia. Patients who undergo cardiac procedures are at risk for poor perfusion of the gastrointestinal tract and, thus, at risk for resulting complications. Risk factors for these complications include peri-operative use of vasopressors, prolonged operative time, and the time of cardiopulmonary bypass. Presentation of gastrointestinal complications tends to differ as patients after open heart surgery can remain intubated, and exams can be limited. Early recognition and aggressive therapy are paramount. We aim to provide a review that will help the reader get familiar with the most common gastrointestinal complications that can negatively affect outcomes after cardiac surgery.

The association of vasoactive-inotropic score and surgical patients' outcomes: a systematic review and meta-analysis

BACKGROUND

The objective of this study is to conduct a systematic review and meta-analysis examining the relationship between the vasoactive-inotropic score (VIS) and patient outcomes in surgical settings.

METHODS

Two independent reviewers searched PubMed, Web of Science, EMBASE, Scopus, Cochrane Library, Google Scholar, and CNKI databases from November 2010, when the VIS was first published, to December 2022. Additional studies were identified through hand-searching the reference lists of included studies. Eligible studies were those published in English that evaluated the association between the VIS and short- or long-term patient outcomes in both pediatric and adult surgical patients. Meta-analysis was performed using RevMan Manager version 5.3, and quality assessment followed the Joanna Briggs Institute (JBI) Critical Appraisal Checklists.

RESULTS

A total of 58 studies comprising 29,920 patients were included in the systematic review, 34 of which were eligible for meta-analysis. Early postoperative VIS was found to be associated with prolonged mechanical ventilation (OR 5.20, 95% CI 3.78-7.16), mortality (OR 1.08, 95% CI 1.05-1.12), acute kidney injury (AKI) (OR 1.26, 95% CI 1.13-1.41), poor outcomes (OR 1.02, 95% CI 1.01-1.04), and length of stay (LOS) in the ICU (OR 3.50, 95% CI 2.25-5.44). The optimal cutoff value for the VIS as an outcome predictor varied between studies, ranging from 10 to 30.

CONCLUSION

Elevated early postoperative VIS is associated with various adverse outcomes, including acute kidney injury (AKI), mechanical ventilation duration, mortality, poor outcomes, and length of stay (LOS) in the ICU. Monitoring the VIS upon return to the Intensive Care Unit (ICU) could assist medical teams in risk stratification, targeted interventions, and parent counseling.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42022359100.

The preoperative SOFA score and remnant small intestine length are postoperative risk factors for mortality in patients with non-occlusive mesenteric ischemia: a case-control study

Aim

Non-occlusive mesenteric ischemia (NOMI) is a fatal condition with a low survival rate in most cases. The risk factors for perioperative mortality in NOMI cases are unclear. The purpose of this study was to define the risk factors for mortality in patients with NOMI undergoing surgery.

Methods

Thirty-eight consecutive patients who underwent surgery for NOMI at Teine Keijinkai Hospital between 2012 and 2020 were included in the study. Patient information, including age, sex, physical findings, comorbidities, laboratory data, and computed tomography and surgical findings were retrospectively analyzed.

Results

Of the 38 patients, 18 (47%) died before discharge. Significant univariate predictors of mortality were a high Sequential Organ Failure Assessment (SOFA) score, high lactate level, low blood pH, and short intestinal length after surgery. In the multivariate analysis, a high SOFA score (odds ratio 1.33, P = 0.036) and short intestine length after surgery (odds ratio 34.7, P = 0.003) were identified as independent risk factors for perioperative mortality.

Conclusion

The preoperative SOFA score and postoperative residual intestinal length may be predictors of death in NOMI surgical patients, not age and the content of comorbidities.

Abdominal atherosclerosis is not a risk factor of nonocclusive mesenteric ischemia among critically ill patients: a propensity matching study

BACKGROUND

Although risk factors of occlusive acute mesenteric ischemia are well known, triggering factors of nonocclusive mesenteric ischemia (NOMI) remain unclear. Alongside to the known risk factors for NOMI, the role of atherosclerosis is not fully elucidated. The purpose of our study was to evaluate whether abdominal atherosclerosis is a risk factor for NOMI.

METHODS

From January 2018 to December 2021, all consecutive patients admitted to the intensive care unit who underwent contrast-enhanced CT for suspicion of NOMI were evaluated for inclusion. Clinical and biological data at the time of the CT scan were retrospectively extracted from medical charts and reviewed by a single radiologist. The cohorts were matched by a 1:1 propensity score based on the patient clinical, biological data, and abdominal CT features associated with NOMI. Noncontrast CT acquisitions were used to calculate calcium scores of the abdominal aorta, celiac trunk, superior mesenteric artery (SMA), and common iliac artery according to the Agatston method. Analyses were performed before and after propensity score matching.

RESULTS

Among the 165 critically ill patients included, 59 (36%) had NOMI. Before matching analysis, the SMA and total abdominal Agatston calcium scores were not different between patients without and with NOMI (52.00 [IQR = 0, 473] vs. 137.00 [IQR = 0, 259], P = 0.857, respectively, and 7253 [IQR = 1220, 21738] versus 5802 [IQR = 2075, 15,084]; P = 0.723). The results were similar after matching 38 patients with NOMI and 38 without: 153 [IQR = 0, 665] versus 85 [IQR = 0, 240] (P = 0.312) for the SMA calcium score, and 7915 [IQR = 1812, 21561] versus 4139 [IQR = 1440, 9858] (P = 0.170) for the total abdominal Agatston calcium score.

CONCLUSION

Our results suggest that atherosclerosis is not a risk factor for NOMI in critically ill patients.

Non-occlusive mesenteric ischemia in critically ill patients

BACKGROUND

Non-occlusive mesenteric ischemia (NOMI) is a life-threatening acute condition that has an overall in-hospital mortality rate of up to 75%. Critically ill patients are often admitted to intensive care units (ICUs) due to shock, and these patients are frequently at risk of developing NOMI. The objective of this study was to determine the clinical features of critically ill patients with NOMI and evaluate the risk factors for in-hospital mortality among these patients.

METHODS

We reviewed the electronic medical records of 7,346 patients who underwent abdominal contrast-enhanced computed tomography during their ICU stay at Samsung Medical Center (Seoul, Korea) between January 1, 2010 and December 31, 2019. After reviewing each patient's computed tomography (CT) scans, 60 patients were diagnosed with NOMI and included in this analysis. The patients were divided into survivor (n = 23) and non-survivor (n = 37) groups according to the in-hospital mortality.

RESULTS

The overall sequential organ failure assessment (SOFA) score for the included patients upon admission to the ICU was 8.6 ± 3.1, and medical ICU admissions were most common (66.7%) among the patients. The SOFA score upon admission to the ICU was higher for the non-survivors than for the survivors (9.4 vs. 7.4; p = 0.017). Non-survivors were more often observed in the medical ICU admissions (39.1% vs. 83.8%) than in the surgical ICU admissions (47.8% vs. 10.8%) or the cardiac ICU admissions (13.0% vs. 5.4%). Laboratory test results, abdominal CT findings, and the use of vasopressors and inotropes did not differ between the two groups. In a multivariable analysis, SOFA scores >8 upon admission to the ICU (odds ratio [OR] 4.51; 95% 1.12-18.13; p = 0.034), patients admitted to the ICU with medical problems (OR 7.99; 95% 1.73-36.94; p = 0.008), and abdominal pain (OR 4.26; 95% 1.05-17.35; p = 0.043) were significant prognostic predictors for in-hospital mortality.

CONCLUSIONS

The SOFA score >8 upon admission to the ICU, admission to the ICU for medical problems, and abdominal pain at diagnosis are associated with increased mortality among patients with NOMI.

Predicting outcomes of mesenteric ischemia postcardiac surgery: A systematic review

OBJECTIVE

This systematic review aims to identify predictors of outcomes of mesenteric ischemia in patients following cardiac surgery.

METHODS

A comprehensive literature search was done on EMBASE, PubMed, Ovid MEDLINE, and SCOPUS using keywords relating to bowel ischemia and cardiac surgery. Database search results were screened by at least two authors and 32 articles were selected for inclusion in this review.

RESULTS

Data on 1907 patients were analyzed. The mean age was 70.0 ± 2.99 years and the prevalence of bowel ischemia was 1.74%. Advanced age was a significant risk factor. 63.16% of patients reported were men, and 58.4% of patients died in hospital. There was heterogeneity in the reported significance of the following preoperative risk factors: hypertension, smoking status, type 2 diabetes mellitus, end-stage renal disease, preoperative left ventricular ejection fraction <35%. Cardiopulmonary bypass (CPB) time, preoperative/operative intra-aortic balloon pump (IABP) support, and inotrope usage were significantly associated with the development of mesenteric ischemia; however, other intraoperative factors including the type of cardiac surgery and duration of aortic cross-clamping had varying levels of reported significance. There were discrepancies in the reported significance of leukocytosis and metabolic acidosis (pH <7.3) as postoperative markers. Postoperative vasopressor use, prolonged ventilation time, and elevation in lactate, transaminases, creatinine, and intestinal fatty acid-binding protein (IFABP) levels were found to be strongly associated with bowel ischemia.

CONCLUSION

This systematic review found the strongest associations of mesenteric ischemia postcardiac surgery to be advanced age, CPB time, rise in lactate, transaminases, creatinine, and IFABP. IABP support, vasopressor, and inotrope use as well as prolonged ventilation were strongly linked too.

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.

Kinetics of serum procalcitonin in patients with acute mesenteric ischemia and bowel infarction after cardiac surgery

BACKGROUND

The present study reports perioperative changes in PCT levels occuring in cardiac patients with acute mesenteric ischemia (AMI) undergoing laparotomy. The aim of this study was to demonstrate that PCT kinetics may confirm the presence of AMI after cardiac surgery, distinguishing between bowel infarction and diffuse ischemia.

METHODS

PCT values from adult patients undergoing laparotomy for AMI after elective or urgent cardiac surgery (January 2010 - December 2019) were determinated at the ICU admission after cardiac surgery, 24 hours later and at the onset of clinical symptoms. Patients affected by diffuse intestinal ischemia with no need for bowel resection were allocated to Group A (n.8), patients presented with intestinal necrosis requiring small or large bowel resection were allocated to Group B (n.12).

RESULTS

At the beginning of the abdominal symptoms, PCT levels increased in both group, compared to those immediately after cardiac surgery. The PCT increasing resulted much more evident in patients presenting with intestinal necrosis - Group B (20.65 ng/ml [IQR8.47-34.5] vs. 4.31 ng/ml [IQR 8.47-34.5], p <0.05), rather than in those with diffuse ischemia - Group A (13.25 ng/ml [IQR 5.97-27.65] vs. 10.4 ng/ml [IQR 3.68-14.05], p 0.260). This trend was confirmed in the subgroup of patients undergoing CVVHD and in patients who experience AMI recurrence.

CONCLUSIONS

Increasing PCT values after cardiac surgery are proportional to the severity of wall ischemia and high levels of PCT are predictive of intestinal necrosis. Routine PCT monitoring after cardiac surgery should be considered extremely useful in suggesting the possibility of abdominal complications, alerting medical staff to the need of prompt treatment.

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

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

Monitoring of the Progression of the Perioperative Serum Lactate Concentration Improves the Accuracy of the Prediction of Acute Mesenteric Ischemia Development After Cardiovascular Surgery

OBJECTIVES

To examine the sensitivity and specificity of perioperative lactate gradients for the prediction of subsequent acute mesenteric ischemia development in patients undergoing cardiovascular surgery.

DESIGN

Retrospective, single-center, case-control study.

SETTING

University hospital.

PARTICIPANTS

The study comprised 108 (1.15%) patients with acute mesenteric ischemia who were selected from 9,385 patients who underwent cardiovascular surgery and were matched to 324 control patients by age and surgery type.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Univariate and logistic regression analyses were used to examine intraoperative and early postoperative lactate levels in patients with and without mesenteric ischemia after cardiac surgery. Late intraoperative lactate concentrations were significantly greater in patients who subsequently developed mesenteric ischemia (p < 0.001). Patients with lactate levels >3 mmol/L had a four-fold increased risk of mesenteric ischemia development (odds ratio [OR] 4.2, 95% confidence interval [CI] 2.4-7.5; area under the curve [AUC] 0.597; p < 0.002). Patients whose lactate levels remained >3 mmol/L on the first postoperative day had a nearly eight-fold increased risk (OR 7.8, 95% CI 4.6-13.3; AUC 0.68; p < 0.001), indicating that mesenteric ischemia developed at an early stage in almost every second patient (p < 0.001). For patients with normal or less elevated lactate levels, similar results were obtained for a >200% increase between the intraoperative and early postoperative periods (OR 4.1, 95% CI 2.4-6.8; AUC 0.62; p < 0.001).

CONCLUSION

Late intraoperative and early postoperative lactate levels >3 mmol/L and increases >200%, even when remaining within the normal range, should raise the suspicion of subsequent mesenteric ischemia development.

The Association of Coloproctology of Great Britain and Ireland consensus guidelines in emergency colorectal surgery

AIM

There is a requirement for an expansive and up to date review of the management of emergency colorectal conditions seen in adults. The primary objective is to provide detailed evidence-based guidelines for the target audience of general and colorectal surgeons who are responsible for an adult population and who practise in Great Britain and Ireland.

METHODS

Surgeons who are elected members of the Association of Coloproctology of Great Britain and Ireland Emergency Surgery Subcommittee were invited to contribute various sections to the guidelines. They were directed to produce a pathology-based document using literature searches that were systematic, comprehensible, transparent and reproducible. Levels of evidence were graded. Each author was asked to provide a set of recommendations which were evidence-based and unambiguous. These recommendations were submitted to the whole guideline group and scored. They were then refined and submitted to a second vote. Only those that achieved >80% consensus at level 5 (strongly agree) or level 4 (agree) after two votes were included in the guidelines.

RESULTS

All aspects of care (excluding abdominal trauma) for emergency colorectal conditions have been included along with 122 recommendations for management.

CONCLUSION

These guidelines provide an up to date and evidence-based summary of the current surgical knowledge in the management of emergency colorectal conditions and should serve as practical text for clinicians managing colorectal conditions in the emergency setting.

The prognostic value of peak arterial lactate levels within 72 h of lung transplantation in identifying patient outcome

Background

Lactic acidosis is often seen in lung transplantation (LTx). Postoperative lactate is frequently associated with poor outcome in postoperative and critically ill patients. Our aim was to evaluate the predictive value of postoperative peak lactate levels within 72 h of LTx for 30-day and late mortality.

Methods

We evaluated patients who underwent LTx from January 2015 to September 2017. All admitted patients were classified according to the peak lactate level (PL) within 72 h of surgery: PL <5 mmol/L (Group 1); PL =5–10 mmol/L (Group 2), and PL >10 mmol/L (Group 3). We performed logistic regression analysis and used Cox regression models to identify the peak lactate level as a predictive factor for 30-day and late mortality, respectively.

Results

Of 255 eligible patients, mean age 55.61±12.16, mean lactate 4.99±2.93 and 80% male, and 40% had hyperlactatemia (PL >5 mmol/L) after LTx. The 30-day mortality rate was 17.9%, 28.9% and 68.8% in the three groups, respectively (P<0.05). Multivariate regression analyses revealed postoperative PL as a notable predictor of 30-day mortality [odds ratio =2.62 (1.42–4.84), P=0.002] as well as for late mortality [hazard ratio =2.70 (1.13–6.42), P=0.025].

Conclusions

The postoperative peak lactate level within 72 h of surgery was an independent predictor for 30-day and late mortality in LTx patients.

Serious Gastrointestinal Complications After Cardiac Surgery and Associated Mortality

BACKGROUND

Severe gastrointestinal (GI) complications (GICs) after cardiac surgery are associated with poor outcomes. Herein, we characterize the severe forms of GICs and associated risk factors of mortality.

METHODS

We retrospectively analyzed the clinically significant postoperative GICs after cardiac surgical procedures performed at our institution from January 2010 to April 2017. Multivariable analysis was used to identify predictors for in-hospital mortality.

RESULTS

Of 29,909 cardiac surgical procedures, GICs occurred in 1037 patients (3.5% incidence), with overall in-hospital mortality of 14% compared with 1.6% in those without GICs. GICs were encountered in older patients with multiple comorbidities who underwent complex prolonged procedures. The most lethal GICs were mesenteric ischemia (n = 104), hepatopancreatobiliary (HPB) dysfunction (n = 139), and GI bleeding (n = 259), with mortality rates of 45%, 27%, and 17%, respectively. In the mesenteric ischemia subset, coronary artery disease (odds ratio [OR], 4.57; P = .002], coronary bypass grafting (OR, 6.50; P = .005), reoperation for bleeding/tamponade (OR, 12.07; P = .01), and vasopressin use (OR, 11.27; P < .001) were predictors of in-hospital mortality. In the HPB complications subset, hepatic complications occurred in 101 patients (73%), pancreatitis in 38 (27%), and biliary disease in 31 (22%). GI bleeding occurred in 20 patients (31%) with HPB dysfunction. In the GI bleeding subset, HPB disease (OR, 10.99; P < .001) and bivalirudin therapy (OR, 12.84; P = .01) were predictors for in-hospital mortality.

CONCLUSIONS

Although relatively uncommon, severe forms of GICs are associated with high mortality. Early recognition and aggressive treatment are mandatory to improve outcomes.

Gastrointestinal complications following cardiac surgery

Gastrointestinal complications after cardiac surgery may be uncommon but they carry high mortality rates. Incidences range from 0.5% to 5.5%, while mortality rates of such complications vary from 0.3% to 87%. They range from small gastrointestinal bleeds, ileus, and pancreatitis to life-threatening complications such as liver failure and ischemic bowel. Due to the vague and often absence of specific signs and symptoms, diagnosis of a gastrointestinal complication is often late. This article aims to review and summarize the literature concerning gastrointestinal complications after cardiac surgery. We discuss the causes, risk factors, diagnosis, preventative measures, and management of these complications. In general, risk factor identification, preventive measures, early diagnosis, and swift management are the keys to reducing the occurrence of gastrointestinal complications and their associated morbidity and mortality.

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.

Early administration of glucocorticoid for thyroid storm: analysis of a national administrative database

Background

Thyroid storm is a life-threatening disease with a mortality rate of over 10%. Although glucocorticoids have been recommended as a treatment option for thyroid storm, supportive evidence based on a large-scale clinical research is lacking. The objective of the current study was to evaluate the beneficial effects of glucocorticoids in the treatment of patients with severe thyroid storm.

Methods

A retrospective nationwide cohort study was conducted using a Japanese national administrative claims database. Patients admitted to intensive care units due to severe thyroid storm between the financial years 2013 and 2017 were included in the study. The primary outcome was in-hospital mortality; secondary outcomes were mortality within 30 days and insulin administration during hospitalization. Generalized linear mixed model (GLMM) with maximum likelihood estimation (MLE) and Bayesian estimation using Markov chain Monte Carlo methods (MCMC), in addition to propensity score matching (PSM), were used for statistical analysis.

Results

A total of 811 patients were included in the study, of which 600 patients were treated with glucocorticoids, and 211 patients were treated without glucocorticoids. The early administration of glucocorticoids was not associated with a significant improvement in the in-hospital mortality of patients with thyroid storm [adjusted odds ratio (95% confidence interval) = 1.77 (0.95–3.34), 1.44 (1.14–1.93), and 1.46 (0.72–3.00) in the GLMM (MLE), GLMM (MCMC), and PSM, respectively]. The results of mortality within 30 days were almost identical to the results of in-hospital mortality. However, insulin use was significantly higher in the glucocorticoid group.

Conclusions

This analysis of a nationwide administrative database indicates that the administration of glucocorticoids does not improve the survival of patients with thyroid storm.

Acute mesenteric ischaemia in refractory shock on veno-arterial extracorporeal membrane oxygenation

BACKGROUND

Acute mesenteric ischaemia is a severe complication in critically ill patients, but has never been evaluated in patients on veno-arterial extracorporeal membrane oxygenation (V-A ECMO). This study was designed to determine the prevalence of mesenteric ischaemia in patients supported by V-A ECMO and to evaluate its risk factors, as well as to appreciate therapeutic modalities and outcome.

METHODS

In a retrospective single centre study (January 2013 to January 2017), all consecutive adult patients who underwent V-A ECMO were included, with exclusion of those dying in the first 24 hours. Diagnosis of mesenteric ischaemia was performed using digestive endoscopy, computed tomography scan or first-line laparotomy.

RESULTS

One hundred and fifty V-A ECMOs were implanted (65 for post-cardiotomy shock, 85 for acute cardiogenic shock, including 39 patients after refractory cardiac arrest). Overall, median age was 58 (48-69) years and mortality 56%. Acute mesenteric ischaemia was suspected in 38 patients, with a delay of four (2-7) days after ECMO implantation, and confirmed in 14 patients, that is, a prevalence of 9%. Exploratory laparotomy was performed in six out of 14 patients, the others being too unstable to undergo surgery. All patients with mesenteric ischaemia died. Independent risk factors for developing mesenteric ischaemia were renal replacement therapy (odds ratio (OR) 4.5, 95% confidence interval (CI) 1.3-15.7, p=0.02) and onset of a second shock within the first five days (OR 7.8, 95% CI 1.5-41.3, p=0.02). Conversely, early initiation of enteral nutrition was negatively associated with mesenteric ischaemia (OR 0.15, 95% CI 0.03-0.69, p=0.02).

CONCLUSIONS

Acute mesenteric ischaemia is a relatively frequent but dramatic complication among patients on V-A ECMO.

What affects the prognosis of NOMI patients? Analysis of clinical data and CT findings

BACKGROUND

Non-occlusive mesenteric ischemia (NOMI) is a mesenteric ischemic disease with considerably high mortality rate, although little has been known about what factors affect the patients' prognosis. The purpose of this study was to investigate prognostic factors of clinical data and computed tomography (CT) findings in patients with NOMI.

METHODS

This was a single institutional, retrospective study, reviewing 21 consecutive patients diagnosed with NOMI on angiography. Patients were divided into either ''survivor'' group or ''non-survivor'' group based on their clinical courses 1 month after diagnosis. Clinical information such as laboratory data, Charlson Comorbidity Index, and time from CT to injecting vasodilator was obtained from patients' medical records. Contrast-enhanced CT images were assessed in following items: defect of mural enhancement, pneumatosis intestinalis, hepatic portal venous gas, paralytic bowel dilatation, bowel wall thinning, and diameters of the relevant vessels.

RESULTS

Eight patients belonged to ''survivor'' group, whereas eleven were allocated to ''non-survivor'' group. None of CT findings showed significant difference between survivor group and non-survivor group [defect of mural enhancement: 75% and 100% (p = 0.16), pneumatosis intestinalis: 50% and 45.5% (p = 1.00), hepatic portal venous gas: 37.5% and 45.5% (p = 1.00), paralytic bowel dilatation: 12.5% and 63.6% (p = 0.06), and bowel wall thinning: 50% and 45.5% (p = 1.00)]. The diameters of the relevant vessels did not have significant difference either. Time from CT to injecting vasodilator was revealed to be significantly shorter in survivor group [187.5 (122.5-294) min and 310 (187-925.5)] (p = 0.048). None of the other clinical information had significant difference between each group.

CONCLUSION

Prompt angiography may be a key to improve the prognosis of NOMI patients.

Clinical features and outcomes of nonocclusive mesenteric ischemia after cardiac surgery: a retrospective cohort study

Nonocclusive mesenteric ischemia after cardiac surgery is a life-threatening complication requiring emergent intervention. However, because of its rarity, the clinical features and outcomes of nonocclusive mesenteric ischemia remain unknown. The present study aimed to clarify patients' backgrounds, clinical features and mortality of nonocclusive mesenteric ischemia after cardiac surgery, using a Japanese national inpatient database. We identified patients undergoing cardiac or thoracic aortic surgery between July 2010 and March 2017, using the Japanese Diagnosis Procedure Combination database. We calculated the incidence proportion of nonocclusive mesenteric ischemia and examined treatment options (bowel resection and interventional radiology) and patients' discharge status (in-hospital mortality and destination of discharge). We identified 221,900 eligible patients to find 568 (0.26%) patients with bowel ischemia in the same admission. Of these, 124 (0.06%) patients developed nonocclusive mesenteric ischemia, and in-hospital mortality after nonocclusive mesenteric ischemia was 77%. Treatment options for nonocclusive mesenteric ischemia included bowel resection alone (n = 34), interventional radiology (n = 15), or both (n = 15); 27, 10, and 8 patients died, respectively. Seven patients (5.6%) were discharged to home. Among 60 patients without bowel resection or interventional radiology, 50 patients died. In multivariable regression analysis, older age, preoperative hemodialysis, preoperative circulatory support, and hypothermic cardiopulmonary bypass were associated with NOMI. The present study showed that nonocclusive mesenteric ischemia after cardiac surgery was very rare. Mortality following nonocclusive mesenteric ischemia was very high even if patients underwent bowel resection or interventional radiology.

Detection of patients at high risk for nonocclusive mesenteric ischemia after cardiovascular surgery

Objectives

Nonocclusive mesenteric ischemia (NOMI) is a rare but life-threatening complication after cardiovascular surgery. Early diagnosis and treatment is essential for a chance to cure. The aim of this study is to identify the independent risk factors for NOMI based on the evaluation of 12 cases of NOMI after cardiovascular surgery.

Methods

We retrospectively analyzed 12 patients with NOMI and 674 other patients without NOMI who underwent cardiovascular surgery in our hospital. We reviewed the clinical data on NOMI patients, including their characteristics and the clinical course. In addition, we performed a statistical comparison of each factor from both NOMI and non-NOMI groups to identify the independent risk factors for NOMI.

Results

The median duration between the cardiac surgery and the diagnosis of NOMI was 14.0 (10.3–20.3) days. The in-hospital mortality of NOMI patients was 75.0%. Age (p < 0.05), peripheral arterial disease (p < 0.001), postoperative hemodialysis (p < 0.001), intraaortic balloon pump (p < 0.05), norepinephrine (NOE) > 0.10γ (p < 0.0001), percutaneous cardiopulmonary support (p < 0.001), sepsis (p < 0.05), loss of sinus rhythm (p < 0.05), prolonged ventilation (p < 0.0001), and resternotomy for bleeding (p < 0.05) showed significant differences between NOMI and non-NOMI groups. In the multivariate logistic regression model, prolonged ventilation [odds ratio (OR) = 18.1, p < 0.001] and NOE > 0.10 μg/kg/min (OR = 130.0, p < 0.0001) were detected as independent risk factors for NOMI.

Conclusions

We have identified the risk factors for NOMI based on the evaluation of the 12 cases of NOMI after cardiovascular surgery. This result may be useful in predicting NOMI, which is considered difficult in clinical practice. For the patient with suspected of NOMI who has these risk factors, early CT scan and surgical exploration should be performed without delay.

The role of multislice computed tomography (MSCT) angiography in the diagnosis and therapy of non-occlusive mesenteric ischemia (NOMI): Could MSCT replace DSA in diagnosis?

Objectives

Evaluation of multislice-CT (MSCT) during diagnosis and therapeutic decision-making in patients with suspected non-occlusive mesenteric ischemia (NOMI).

Methods

Retrospective, institutional review board-approved study of 30 patients (20 men, 10 women, mean age 64.6±14.2 years, range 24–87 years) undergoing biphasic abdominal MSCT followed by digital subtraction angiography (DSA) due to suspected NOMI. MSCT and DSA were qualitatively and quantitatively evaluated independently by two radiologists with respect to the possible diagnosis of NOMI. MSCT analysis included quantitative measurements, qualitative evaluation of contrast enhancement and assessment of secondary findings (bowel wall thickening, hypo-enhancement, intestinal pneumatosis). MSCT diagnosis and secondary findings were compared against DSA diagnosis.

Results

NOMI was diagnosed in a total of n = 28 patients. No differences were found when comparing the R1-rated MSCT diagnosis (p = 0.09) to the “gold standard”, while MSCT diagnosis was slightly inferior with R2 (p = 0.02). With R1, vessel-associated parameters revealed the best correlation, i.e. qualitative vessel width (r = -0.39;p = 0.03) and vessel contrast (r = 0.45;p = 0.01). Moderate correlations were found for quantitative vessel diameters in the middle segments (r = -0.48,p = 0.01), increasing to almost high correlations in the distal (r = -0.66;p<0.00001) superior mesenteric artery (SMA) segments. No significant correlation was apparent from secondary findings.

Conclusions

MSCT is an appropriate non-invasive method for diagnosing NOMI and leads to adequate and immediate therapeutic stratification.