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

Long-term outcome after implementation of endovascular-first strategy to treat acute mesenteric ischemia

OBJECTIVE

To evaluate the rationale of an aggressive endovascular-first strategy to treat elderly patients with acute mesenteric ischemia (AMI) by studying long-term survival, readmissions, and patients' discharge to home vs nursing facility a decade after an episode of AMI.

METHODS

The retrospective study cohort included 66 consecutive patients (all-comers) treated for arterial occlusive AMI between 2009 and 2013. Endovascular revascularization (EVR) was attempted in 50 patients (EVR+), whereas 16 patients were treated without attempted revascularization (EVR-). All patients were followed until death or September 2022. Studied outcomes included discharge status, long-term survival and cause of death and readmissions related to AMI.

RESULTS

The mean age of all 66 patients was 78 ± 10 years: 79 ± 9 years in the EVR+ group and 76 ± 12 years in the EVR- group. EVR was technically successful in 44 patients (88%); three patients underwent subsequent open revascularization after EVR failure. One-third required bowel resection after EVR. The 30-day mortality for all patients was 44%; 32% in the EVR+ group and 81% in the EVR- group. Only two survivors were permanently institutionalized, whereas all others were discharged to the same place they lived prior to the AMI episode. There were four AMI-related readmissions during the follow-up; all were in the EVR+ group. Two patients underwent reinterventions for recurrent AMI. One-year survival was 52% for EVR+ and 19% for EVR- patients. Five-year survival rates were 18% and 13%, respectively. The causes of deaths were mesenteric ischemia in 22, other cardiovascular event in 21, and non-cardiovascular cause in 19 patients. Four patients were alive at the end of the follow-up.

CONCLUSIONS

In this unselected elderly population with AMI, the aggressive strategy to attempt EVR resulted in a high revascularization rate and favorable outcomes. The high proportion of patients returning to their prior living status and low readmission rate after survival from AMI encourages active treatment of high-functioning elderly patients.

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.

Contemporary management of acute and chronic mesenteric ischemia: 10-year experience from a multihospital healthcare system

OBJECTIVE

Endovascular and hybrid methods are being increasingly used to treat mesenteric ischemia. However, long-term outcomes and risk of symptom recurrence remain unknown. The objective of this study was to define predictors of post-operative morbidity, mortality, and patency loss in acute (AMI) or chronic mesenteric ischemia (CMI).

METHODS

Inpatient and follow-up records for all patients who underwent revascularization for AMI and CMI from 2010 to 2020 at a multicenter hospital system were reviewed. Patency and mortality were evaluated with Cox regression, visualized with Kaplan-Meier curves, and compared using log rank testing. Patency was further evaluated with Fine-Gray regression utilizing death as a competing risk. Post-operative major adverse events (MAE) and 30-day mortality were evaluated with logistic regression.

RESULTS

407 patients were included; 148 AMI and 259 CMI. In AMI, 30-day mortality was 31%. Open surgery was associated with lower rates of bowel resection (OR 0.23, 95% CI 0.13, 0.61). Etiology of AMI also did not change outcomes (OR 1.30, 95% CI 0.77, 2.19). Adjusted analyses indicates that a history of diabetes (OR 2.77, 95% CI 1.37, 5.61) and sepsis on presentation (OR 2.32, 95% CI 1.18, 4.58) were independently associated with increased risk of 30-day MAE. In CMI, open surgery and CKD were associated with higher MAE (OR 3.03, 95% CI 1.14, 8.05; OR 2.37, 95% CI 1.31, 4.31) while CKD (OR 3.02, 95% CI 1.10, 8.37) and inpatient status prior to revascularization (OR 2.78, 95% CI 1.01, 7.61) were associated with increased 30-day mortality. In CMI, patients in the endovascular cohort had higher rates of symptom recurrence (29% vs. 13%) with faster onset (endovascular 64 days vs. bypass 338 days).

CONCLUSIONS

AMI remains a morbid disease despite evolving revascularization techniques. An open approach should remain the gold standard as it reduces likelihood of bowel resection. In CMI, endovascular interventions have improved post-operative morbidity but result in early symptom recurrence and re-interventions. An endovascular-first approach should be standard in CMI with close surveillance.

Incidence of contrast-induced acute kidney injury in patients with acute mesenteric ischemia and identification of potential predictive factors

OBJECTIVE

Contrast-enhanced computed tomography angiography (CTA) is commonly used to investigate acute abdominal conditions, but the risk of contrast-induced acute kidney injury (CI-AKI) has been poorly investigated in patients with acute mesenteric ischemia. The aim of the present study was to evaluate the incidence of CI-AKI in these patients and identify potential predictive factors.

METHODS

Patients admitted for acute mesenteric ischemia who had a diagnostic CTA with contrast medium and a follow-up of creatinine concentration were retrospectively included.

RESULTS

Among 53 patients included, 9 (16.9%) developed CI-AKI. The prevalence of chronic kidney disease did not differ significantly between those who developed CI-AKI and those who did not (33.3 vs 18.2%, p=.372). Plasma total bilirubin and conjugated bilirubin levels were significantly higher in patients who developed CI-AKI (17.5 vs 8.0 μmol/L, p=.013 and 8.0 vs 3.0 μmol/L, p=.031, respectively). The proportion of patients who had revascularization was similar between patients who developed CI-AKI and those who did not (11.1 vs 20.5%, p>.999). No significant difference was observed for 30-day mortality and all-cause mortality for a median follow-up of 168 days (22.2 vs 13.6%, p=.611; and 33.3 vs 61.4%, p=.153, respectively).

CONCLUSION

This study reports the incidence of CI-AKI in patients with acute mesenteric ischemia after diagnostic CTA with contrast medium. Plasma bilirubin levels were a predictive factor of CI-AKI in these patients. The administration of contrast media during revascularization was not associated with an increased risk of CI-AKI.

Hospital-based Delays to Revascularization Increase Risk of Post-operative Mortality and Short Bowel Syndrome in Acute Mesenteric Ischemia

OBJECTIVE

Acute mesenteric ischemia (AMI) is a surgical emergency for which delays in treatment have been closely associated with high morbidity and mortality. Although the duration of ischemia as a determinant of outcomes for AMI is well known, the objective of this study was to identify hospital-based determinants of delayed revascularization and their effects on post-operative morbidity and mortality in AMI.

METHODS

All patients who underwent any surgery for acute mesenteric ischemia (AMI) from a multi-center hospital system between 2010 and 2020 were divided into two groups based on timeliness of mesenteric revascularization after presentation. Early revascularization (ER) was defined as having both vascular consultation ≤ 12 hours of presentation and vascular surgery performed at the patient's initial operation. Delayed revascularization (DR) was defined as having either delays to vascular consultation or vascular surgery. A retrospective review of demographic and post-operative data was performed. Effect of DR on major post-operative outcomes including 30-day and 2-year mortality, total length of bowel resection, and development of short bowel syndrome were analyzed. Effects of delayed vascular consultation alone, delayed vascular surgery alone, no revascularization during admission, and admitting service on outcomes were also examined on sub-group analyses.

RESULTS

A total of 212 patients were analyzed. 99 patients received ER while the remaining 113 patients experienced a delay to revascularization after hospital presentation. Among the DR group, 55 (25.9%) patients had delayed vascular consultation while vascular surgery was deferred until after the initial operation in 37 (17.4%) patients. 51 (24.0%) patients were never revascularized during admission. DR was a significant predictor of 30-day (odds ratio (OR) 2.09, 95% confidence interval (CI) [1.4-4.9], P=0.03) and 2-year mortality (hazard ratio (HR) 1.55, CI [1.0-2.3], P= 0.04). DR was also independently associated with increased bowel resection length (OR 7.47, P <0.01) and post-operative short bowel syndrome (OR 2.4, P=0.03) on multivariate analyses. When examined separately on sub-group analysis, both delayed vascular consultation (OR 3.38, P=0.03) and vascular surgery (OR 4.31, P <0.01) independently increased risk of 30-day mortality. Hospital discharge after AMI without mesenteric revascularization was associated with increased risk of short bowel syndrome (OR 2.94, P <0.01) and late mortality (HR 1.60, P=0.04).

CONCLUSIONS

Delayed vascular consultation and vascular surgery are both significant hospital-based determinants of post-operative mortality and short bowel syndrome in AMI. Timing-based management protocols which emphasize routine evaluation by a vascular surgeon and early, definitive mesenteric revascularization should be established and widely adopted for all patients with clinically suspected AMI at presentation.