What is the Best Revascularization Strategy for Acute Occlusive Arterial Mesenteric Ischemia: Systematic Review and Meta-analysis

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

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

Advancements in Revascularization Strategies for Acute Mesenteric Ischemia: A Comprehensive Review

Even with modern advancements in the management of acute mesenteric ischemia over the past decade, morbidity and mortality remain high, and the best primary treatment modality is still debated amongst interventionalists. Traditionally, interventionalists have favored an open surgical approach but are now trending for endovascular interventions due to apparent reduced mortality and complications. Newer studies suggest hybrid approaches, and intestinal stroke centers may be superior to either strategy alone. This narrative review will explore the natural history of acute mesenteric ischemia with the aim of increasing interventionalist awareness of modern advancements in revascularization strategies for this devastating disease.

Current Approaches for Mesenteric Ischemia and Visceral Aneurysms

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

Strengthening the Description of Superior Mesenteric Artery Occlusions in Acute Mesenteric Ischaemia: Proposition for an Anatomical Classification

OBJECTIVE

The aim of this study was to propose computed tomography angiography (CTA) based anatomical segmentation of the superior mesenteric artery (SMA), in order to standardise the reporting of occlusive lesions in acute mesenteric ischaemia (AMI).

METHODS

A retrospective CTA evaluation of patients with occlusive AMI admitted between 2016 and 2021. After the screening of 468 patients, 95 were included. The SMA was segmented into proximal (S1, ostium to the inferior pancreaticoduodenal artery), middle (S2, from the inferior pancreaticoduodenal to the ileocolic artery), and distal (S3, downstream the ileocolic artery) sections. The jejunal arteries were labelled J1 to J6, and the middle, right, and ileocolic arteries C1, C2, and C3. Two radiologists independently applied the proposed segmentation to a cohort of patients with occlusive AMI to describe occlusive lesions. Intra- and inter-rater agreement was assessed with kappa statistics.

RESULTS

Occlusions involved one segment in 50 (53%) patients (S1, n = 27 [28%]; S2, n = 12 [13%]; S3, n = 11 [12%]); two segments in 37 (39%) patients (S2/S3, n = 31 [33%]; S1/S2, n = 3 [3%]; S1/S3, n = 3 [3%]); and all three segments in eight patients (S1/S2/S3, 8%). The median number of jejunal arteries was four (interquartile range 3, 4.5). C1 and C2 were present in 93 (98%) and 23 patients (24%), respectively. Almost perfect intra-rater agreement was obtained for S1 (91% agreement, κ = 0.82, 95% confidence interval [CI] 0.72 - 0.92); substantial agreement was obtained for S2 (90% agreement, κ = 0.80, 95% CI 0.68 - 0.92) and S3 (86% agreement, κ = 0.72, 95% CI 0.58 - 0.86). Almost perfect inter-rater agreement (with the second junior reading) was obtained for S1 (97% agreement, κ = 0.95, 95% CI 0.89 - 1.0), S2 (91% agreement, κ = 0.82, 95% CI 0.72 - 0.92), and S3 (agreement 96%, κ = 0.91, 95% CI 0.83 - 0.99).

CONCLUSION

A standardised CTA based anatomical segmental description of SMA occlusive lesions in AMI is proposed; it provided substantial to almost perfect intra- and inter-rater agreement for most anatomical segments.

Case report: ultrasound assisted catheter directed thrombolysis of an embolic partial occlusion of the superior mesenteric artery

Acute mesenteric ischemia (AMI) is a severe medical condition defined by insufficient vascular supply to the small bowel through mesenteric vessels, resulting in necrosis and eventual gangrene of bowel walls. We present the case of a 64-year-old man with recrudescence of prolonged epigastric pain at rest of few hours duration, cold sweating and episodes of vomiting. A computed tomography scan of his abdomen revealed multiple filling defects in the mid-distal part of the superior mesenteric artery (SMA) and the proximal part of jejunal branches, associated with small intestine walls thickening, suggesting SMA thromboembolism and initial intestinal ischemia. Considering the absence of signs of peritonitis at the abdominal examination and the presence of multiple arterial emboli was decided to perform an endovascular treatment with ultrasound assisted catheter-directed thrombolysis with EkoSonic Endovascular System-EKOS, which resulted in complete dissolution of the multiple emboli and improved blood flow into the intestine wall. The day after the procedure the patient's pain improved significantly and 5 days after he was discharged home asymptomatic on warfarin anticoagulation. After 1 year of follow-up the patient is fine with no further episodes of mesenteric ischemia or other embolisms.

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.

The Influencing Factors and Prognostic Evaluation in the Treatment Decisions for Acute and Subacute Nondissection-Related Superior Mesenteric Artery Thromboembolism

BACKGROUND

The unclarified treatment strategy for acute and subacute ndSMA-TE limits the therapeutic efficacy and worsens the prognosis. This study aimed to determine the predictive factors impacting the treatment strategy for acute and subacute ndSMA-TE.

METHOD

A database of 116 patients with nonchronic ndSMA-TE admitted between January 2001 and December 2021 was retrospectively analyzed. Univariate/multivariate logistic regression and the predictive models constructed by stepwise backward regression were used to explore the influencing factors of the treatment decisions and the risk factors for failed conservative treatment. The EuroQol-5 Dimension questionnaire was used to evaluate the long-term quality of life.

RESULTS

Only the white blood cell (WBC) levels were significantly different between the conservative group and the surgical group (P = 0.013 < 0 .05, odds ratio (OR) = 1.153, 95% confidence interval (CI) [1.038, 1.306]). The WBC levels (P < 0.001, OR = 1.169, 95% CI [1.080, 1.286]) and heart diseases (except atrial fibrillation) (P = 0.011 < 0 .05, OR = 5.116, 95% CI [1.541, 20.452]) were included in the predictive model of the treatment decision. The hemoglobin levels (P = 0.005 < 0 .05, OR = 1.095, 95% CI [1.040, 1.187]) and no flatus or stool (P = 0.007 < 0 .05, OR = 0.031, 95% CI [0.002, 0.296]) were significant risk factors for the conservative treatment outcome. The EuroQol-5 Dimension evaluation demonstrated a fairly high long-term quality of life in both treatment strategies.

CONCLUSIONS

Elevated WBC levels, decreased hemoglobin levels, and no flatus or stool can be used as predictive indicators for the surgical treatment of nonchronic ndSMA-TE to avoid a misdiagnosis and an inappropriate treatment.

Treatment of Acute Mesenteric Ischemia: Individual Challenges for Interventional Radiologists and Abdominal Surgeons

Background: Acute mesenteric ischemia (AMI) is a life-threatening condition resulting from occlusion of the mesenteric arterial vessels. AMI requires immediate treatment with revascularization of the occluded vessels. Purpose: to evaluate the technical success, clinical outcomes and survival of patients receiving endovascular treatment for AMI followed by surgery. Material and Methods: A search of our institution’s database for AMI revealed 149 potential patients between 08/2016 and 08/2021, of which 91 were excluded due to incomplete clinical data, insufficient imaging or missing follow-up laparoscopy. The final cohort included 58 consecutive patients [(median age 73.5 years [range: 43−96 years], 55% female), median BMI 26.2 kg/m2 (range:16.0−39.2 kg/m2)]. Periinterventional imaging regarding the cause of AMI (acute-embolic or acute-on-chronic) was evaluated by two radiologists in consensus. The extent of AMI and the degree of technical success was graded according to a modified TICI (Thrombolysis in Cerebral Infarction scale) score (TICI-AMI) classification (0: no perfusion; 1: minimal; 2a < 50% filling; 2b > 50%; 2c: near complete or slow; 3: complete). Lab data and clinical data were collected, including the results of follow-up laparoscopy. Non-parametric statistics were used. Results: All interventions were considered technically successful. The most common causes of AMI were emboli (51.7%) and acute-on-chronic thrombotic occlusions (37.9%). Initial imaging showed a TICI-AMI score of 0, 1 or 2a in 87.9% (n = 51) of patients. Post-therapeutic TICI-AMI scores improved significantly with 87.9% of patients grade 2b and better. Median lactate levels reduced from 2.7 (IQR 2.0−3.7) mg/dL (1−18) to 1.45 (IQR 0.99−1.90). Intestinal ischemia was documented in 79.1% of cases with resection of the infarcted intestinal loops. In total, 22/58 (37.9%) patients died during the first 30 days after intervention and surgery. According to CIRSE criteria, we did not observe any SAE scores of grade 2 or higher. Conclusions: AMI is a serious disease with high lethality within the first 30 days despite optimal treatment. However, interventional revascularization before surgery with resection of the infarcted bowel can save two out of three of critically ill patients.

Reperfusion injury on computed tomography following endovascular revascularization of acute mesenteric ischemia: prevalence, risk factors, and patient outcome

BACKGROUND

Data about reperfusion injury (RI) following acute arterial mesenteric ischemia (AAMI) in humans are scarce. We aimed to assess the prevalence and risk factors of RI following endovascular revascularization of AMI and evaluate its impact on patient outcomes.

METHODS

Patients with AAMI who underwent endovascular revascularization (2016-2021) were included in this retrospective cohort. CT performed < 7 days after treatment was reviewed to identify features of RI (bowel wall hypoattenuation, mucosal hyperenhancement). Clinical, laboratory, imaging, and treatments were compared between RI and non-RI patients to identify factors associated with RI. Resection rate and survival were also compared.

RESULTS

Fifty patients (23 men, median 72-yrs [IQR 60-77]) were included, and 22 were diagnosed with RI (44%) after a median 28 h (22-48). Bowel wall hypoattenuation and mucosal hyperenhancement were found in 95% and 91% of patients with post-interventional RI, respectively. Patients with RI had a greater increase of CRP levels after endovascular treatment (p = 0.01). On multivariate analysis, a decreased bowel wall enhancement on baseline CT (HR = 8.2), an embolic cause (HR = 7.4), complete SMA occlusion (HR = 7.0), and higher serum lactate levels (HR = 1.4) were associated with RI. The three-month survival rate was 78%, with no difference between subgroups (p = 0.99). However, the resection rate was higher in patients with RI (32% versus 7%; p = 0.03).

CONCLUSION

RI is frequent after endovascular revascularization of AAMI, especially in patients who present with decreased bowel wall enhancement on pre-treatment CT, an embolic cause, and a complete occlusion of the SMA. However, its occurrence does not seem to negatively impact short-term survival.

Severe Klebsiella pneumoniae pneumonia complicated by acute intra-abdominal multiple arterial thrombosis and bacterial embolism: A case report

BACKGROUND

Klebsiella pneumoniae (K. pneumoniae) is a clinically common Gram-negative bacillus that can cause community- and hospital-acquired infections and lead to pneumonia, liver abscesses, bloodstream infections, and other infectious diseases; however, severe pneumonia caused by hypervirulent K. pneumoniae (hvKp) complicated by acute intra-abdominal multiple arterial thrombosis and bacterial embolism is rarely seen in the clinical setting and has not been reported in the literature.

CASE SUMMARY

A 51-year-old man was hospitalized with fever and dyspnea. Persistent mild pain in the middle and upper abdomen began at dawn on the 3^rd day following admission and developed into persistent severe pain in the left upper abdomen 8 h later. Based on chest computed tomography (CT), bronchoscopy, bronchoalveolar lavage fluid metagenomic next-generation sequencing, abdominal aortic CT angiography (CTA), and culture of the superior mesenteric artery embolus, adult community-acquired severe hvKp pneumonia complicated by acute intra-abdominal multiple arterial thrombosis and bacterial embolism was diagnosed. Notably, he recovered and was discharged from the hospital after receiving effective meropenem anti-infection, endovascular contact thrombolytic, and systemic anticoagulant therapies and undergoing percutaneous thrombus aspiration. Ten days later, the patient returned to the hospital for abdominal CTA examination, which indicated blocked initial common pathway of the celiac trunk and superior mesenteric artery, and local stenosis. Therefore, celiac trunk artery stenting was performed in Chongqing Hospital, and postoperative recovery was good.

CONCLUSION

We report a case of hvKp severe pneumonia complicated by acute intra-abdominal multiple arterial thrombosis and bacterial embolism and suggest that clinicians should consider the possibility of a Gram-negative bacillus infection and conduct effective pathogen detection in a timely fashion when managing patients with severe community-acquired pneumonia before obtaining bacteriologic and drug sensitivity results. At the same time, when patients have severe pulmonary infection complicated by severe abdominal pain, an acute mesenteric artery embolism should be considered to avoid delays in treatment.

Endovascular revascularization of acute arterial mesenteric ischemia: report of a 3-year experience from an intestinal stroke center unit

OBJECTIVE

To report the 3-year experience of endovascular revascularization of acute arterial mesenteric ischemia (AMI) from an intestinal stroke center unit (ISCU).

METHOD

All data from patients admitted to the ISCU between January 2016 and January 2019 for arterial AMI who underwent endovascular recanalization were prospectively acquired and retrospectively analyzed. Patient demographics, clinical and laboratory characteristics at presentation, and CT scans were reviewed. The type (thrombolysis, thrombectomy, stenting) and the outcome of endovascular procedures (technical success or failure, complications) were noted. Care pathways were described focusing on post-procedural treatments (surgical revascularization, bowel resection) and the mortality rate was evaluated in subgroups.

RESULTS

Fifty-eight patients (34 men [59%], mean 69 ± 29 years) were included. Endovascular revascularization was technically successful in 51/58 (88%) patients, and 10 (17%) patients had post-procedural complications. Stenting and in situ thrombolysis were performed in most patients (n = 33 and n = 19, respectively). Thirty-two patients (55%) were recurrence-free and required no further treatment after the procedure, while 9 (16%), 5 (9%), and 5 (9%) patients underwent 2nd-line bowel resection, surgical revascularization, or both. Overall, 46 (79%), 45 (78%), and 34 patients (63%) were alive at 3 months, 1 year, and 3 years. No significant difference in survival was found in care pathways or baseline characteristics.

CONCLUSION

Endovascular revascularization is highly feasible for the treatment of arterial AMI, and is associated with an acceptable rate of complications. Results of endovascular revascularization shall only be interpreted as part of a multidisciplinary patient management strategy.

KEY POINTS

• Endovascular revascularization is highly feasible for the treatment of arterial AMI, and is associated with an acceptable rate of complications. • Several techniques are available to perform endovascular revascularization, and their use depends on the cause, the location, and the quality of underlying arteries of patients. • Results of endovascular revascularization shall only be interpreted in relation to its role in an integrated multidisciplinary and patient management strategy.

Acute Mesenteric Ischemia in Patients with COVID-19: Review of the literature

The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has resulted in a global health emergency. In addition to common respiratory symptoms, some patients with COVID-19 infections may experience a range of extra-pulmonary manifestations, such as digestive system involvement. Patients with COVID-19 have been reported to suffer from acute mesenteric ischemia (AMI) that is associated with disease-related severity and mortality. However, in the context of COVID-19, the exact cause of AMI has yet to be clearly defined. This review provides a comprehensive overview of the available data and elucidates the possible underlying mechanisms linking COVID-19 to AMI, in addition to highlighting therapeutic approaches for clinicians. Finally, given the severe global impact of COVID-19, we emphasize the importance of coordinated vaccination programs.

Intraoperative HIFU Ablation of the Pancreas Using a Toroidal Transducer in a Porcine Model. The First Step towards a Clinical Treatment of Locally Advanced Pancreatic Cancer

Apart from palliative chemotherapy, no other therapy has been proven effective for the treatment of locally advanced pancreatic tumors. In this study, an intraoperative high-intensity focused ultrasound (HIFU) device was tested in vivo to demonstrate the feasibility of treating the pancreatic parenchyma and tissues surrounding the superior mesenteric vessels prior to clinical translation of this technique. Twenty pigs were included and treated using a HIFU device equipped with a toroidal transducer and an integrated ultrasound imaging probe. Treatments were performed with energy escalation (from 30 kJ to 52 kJ). All treatments resulted in visible (macroscopically and in ultrasound images) homogeneous thermal damage, which was confirmed by histology. The dimensions of thermal lesions measured in ultrasound images and those measured macroscopically were correlated (r = 0.82, p < 0.05). No arterial spasms or occlusion were observed at the lowest energy setting. Temporary spasm of the peripancreatic artery was observed when using an energy setting greater than 30 kJ. The possibility of treating the pancreas and tissues around mesenteric vessels without vascular thrombosis holds great promise for the treatment of locally advanced pancreatic cancers. If clinically successful, chemotherapy followed by HIFU treatment could rapidly become a novel treatment option for locally advanced pancreatic cancer.

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.

Endovascular Revascularization with Stent Implantation in Patients with Acute Mesenteric Ischemia due to Acute Arterial Thrombosis: Clinical Outcome and Predictive Factors

Purpose

To determine 30-day-mortality rates and identify predictors for survival in patients undergoing endovascular revascularization for acute mesenteric ischemia (AMI) due to occlusion of the celiac (CA) or superior mesenteric artery (SMA) from arterial thrombosis in the setting of atherosclerosis at the vessel origin.

Materials and Methods

A retrospective analysis on patients who underwent acute endovascular revascularization to treat AMI caused by thrombotic occlusion of the CA and/or SMA between January 2011 and December 2019 was conducted. 30-day-mortality rates were calculated. Univariate binomial logistic regression analyses (p < 0.05) were performed to assess whether the following factors were associated with 30-day mortality: sex, age, history of smoking, history of abdominal angina, signs of bowel necrosis on pre-interventional CT, one- vs. two-vessel disease, patency of the inferior mesenteric artery, outpatient or inpatient occurrence of ischemia, onset of AMI during ITU stay, elevated pre-interventional serum lactate levels, total leukocyte count, platelet/lymphocyte ratio and neutrophil/lymphocyte ratio.

Results

40 patients were included in this analysis. 30-day-mortality rate was 25/40 (62.5%). Median overall survival of patients who survived the first 30 days was 36 ± 18 months. None of the analyzed factors was statistically significantly associated with 30-day mortality.

Conclusion

Although mortality of patients with AMI due to acute arterial thrombosis remains high, almost 40% of patient who underwent emergent endovascular revascularization survived longer than one month. Since no predictors for the outcome in these patients were identified, all patients with AMI should be offered an immediate revascularization effort.

Retrograde open mesenteric stenting should be considered as the initial approach to acute mesenteric ischemia

OBJECTIVE

Retrograde open mesenteric stenting (ROMS) is an alternative to traditional bypass in patients who present with acute mesenteric ischemia (AMI). However, there is a paucity of data comparing outcomes of ROMS with other open surgical approaches. This study represents the largest single-institution experience with ROMS and aims to compare outcomes of ROMS with those of conventional mesenteric bypass.

METHODS

All patients who presented with AMI from 2008 to 2019 and who were treated with either ROMS or mesenteric bypass were included in the study. Patient, procedure, and outcome variables were compared. Bypass and ROMS patients were compared using univariate statistics.

RESULTS

A total of 34 patients who presented with AMI needing bypass were included in the study; 16 underwent mesenteric bypass, and 18 underwent ROMS. ROMS patients tended to be older than bypass patients and had higher rates of comorbidities. Bypass patients were more likely to have a history of chronic mesenteric symptoms (68.8% vs 27.8%; P = .019). Bypass procedures also took longer than ROMS procedures (302 vs 189 minutes; P < .01). The majority of ROMS procedures were not performed in a hybrid room (77.8%). Within 1 year, one stent thrombosed in a ROMS patient, requiring later mesenteric bypass. In the bypass group, one conduit thrombosed, ultimately resulting in perioperative death, and one bypass anastomosis stenosed, requiring angioplasty. Complication, unanticipated reintervention, and mortality rates were otherwise similar between groups.

CONCLUSIONS

Complication, reintervention, and mortality rates after ROMS are similar to those of mesenteric bypass in the setting of AMI. Given similar postoperative outcomes and ability to perform these procedures in a conventional operating room but with significantly shorter operative times, ROMS should be considered a first-line option in acute situations when the operator is comfortable performing the procedure.

High-Value Multidetector CT Angiography of the Superior Mesenteric Artery: What Emergency Medicine Physicians and Interventional Radiologists Need to Know

The superior mesenteric artery (SMA) provides vital blood supply to the midgut, and an acute abnormality can rapidly precipitate bowel ischemia and infarction and lead to morbidity and mortality. Vascular diseases that acutely compromise the SMA threaten its tributaries and include occlusion, dissection, aneurysm rupture, pseudoaneurysm, vasculitis, and SMA branch hemorrhage into the bowel. Emergency medicine physicians rely on the radiologist to identify SMA abnormalities, to characterize them, and to detail findings that guide the appropriate triage of these patients. As such, radiologists must be cognizant of the features that influence patient treatment to assist vascular surgeons and interventional radiologists in decision making. Some patients can be treated medically, while clinical and radiographic findings may suggest the need for interventional or surgical repair of the artery. In the latter case, multidetector CT findings aid in determining which of the various surgical and endovascular treatment options is optimal, and both vascular and gastrointestinal sequelae of acute SMA abnormalities contribute to these determinations. The authors review acute life-threatening conditions involving the SMA including acute occlusion, dissection, aneurysm, pseudoaneurysm, and hemorrhage and discuss the vascular and gastrointestinal multidetector CT findings in each of these conditions that help to guide surgical and interventional management. ^©RSNA, 2019.

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.

Predictive Factors of Intestinal Necrosis in Acute Mesenteric Ischemia

Objectives

Acute mesenteric ischemia (AMI) is a gastrointestinal and vascular emergency in which the detection of patients requiring intestinal resection is mandatory.

Methods

Registered data of 55 consecutive patients admitted to our center between January 2010 and December 2016 that underwent an explorative laparotomy for a suspected diagnosis of irreversible transmural intestinal necrosis (ITIN) were analyzed. Demographic, clinical, laboratory and CT findings were statistically analyzed in order to search predictive factors of ITIN and their correlation to its clinical spectre.

Results

Tobacco use was the most statistically significant (p<0.01) cardiovascular disease risk factor involved in ITIN. Among lab tests, Serum lactate levels ˃ 2mmol/L resulted in a statistically significant association with ITIN (p=0.0001). Organ failure (defined as Marshall score> 2) and the three main CT findings (decreased bowel wall enhancement, bowel loop dilation and demonstrated vessel occlusion) were strongly associated with ITIN (p values: 0.001, 0.007, 0.0013, 0.0005). Only serum lactate levels>2 mmol/L resulted as statistically significant as predictive factors of ITIN in multivariate analysis using logistic regression (OR 49.66 and p-value 0.0021).

Conclusion

Our univariate and multivariate analysis identified multiple factors (Serum lactate levels ˃ 2mmol/L, Organ failure, CT signs) that could suggest patients that require a surgical approach for ITIN.

Outcomes of antegrade and retrograde open mesenteric bypass for acute mesenteric ischemia

BACKGROUND

Acute mesenteric ischemia (AMI) is a challenging clinical problem associated with significant morbidity and mortality. Few contemporary reports focus specifically on patients undergoing open mesenteric bypass (OMB) or delineate outcome differences based on bypass configuration. This is notable, because there is a subset of patients who are poor candidates for endovascular intervention including those with flush mesenteric vessel occlusion, long segment occlusive disease, and a thrombosed mesenteric stent and/or bypass. This analysis reviewed our experience with OMB in the treatment of AMI and compared outcomes between patients undergoing either antegrade or retrograde bypass.

METHODS

A single-center, retrospective review was performed to identify all patients who underwent OMB for AMI from 2002 to 2016. A preoperative history of mesenteric revascularization, demographics, comorbidities, operative details, and outcomes were abstracted. The primary end point was in-hospital mortality. Secondary end points included complications, reintervention, and overall survival. Kaplan-Meier estimation and Cox proportional hazards regression were used to analyze all end points.

RESULTS

Eighty-two patients (female 54%; age 63 ± 12 years) underwent aortomesenteric bypass (aortoceliac/superior mesenteric, n = 44; aortomesenteric, n = 38) for AMI. A history of prior stent/bypass was present in 20% (n = 16). A majority (76%; n = 62) underwent antegrade bypass and the remainder received retrograde infrarenal aortoiliac inflow. Patients receiving antegrade OMB were more likely to be male (53% vs 25%; P = .02), have coronary artery disease (48% vs 25%; P = .06), chronic obstructive pulmonary disease (52% vs 25%; P = .03), and peripheral arterial disease (60% vs 35%; P = .05). Concurrent bowel resection was evenly distributed (antegrade, 45%; retrograde, 45%; P = .9) and 37% (n = 30) underwent subsequent resection during second look operations. The median duration of stay was 16 days (interquartile range, 9-35 days) and 78% (n = 64) experienced at least one major complication with no difference in rates between antegrade/retrograde configurations. In-hospital mortality was 37% (n = 30; multiple organ dysfunction, 22; bowel infarction, 4; hemorrhage/anemia, 2; arrhythmia, 1; stroke, 1; 30-day mortality, 26%). The median follow-up was 8 months (interquartile range, 1-26 months). The 1- and 3-year primary patency rates were both 82% ± 6% (95% confidence interval, 71%-95%), with 10 patients requiring reintervention. Estimated survival at 1 and 5 years was 57% ± 6% and 50% ± 6%, respectively. Bypass configuration was not associated with complication rates (P > .10), in-hospital mortality (log-rank, P = .3), or overall survival (log-rank, P = .9). However, a higher risk of reintervention was observed in patients undergoing retrograde bypass (hazard ratio, 3.0; 95% confidence interval, 0.9-11.0; P = .08).

CONCLUSIONS

OMB for AMI results in significant morbidity and mortality, irrespective of bypass configuration. Antegrade OMB is associated with comparable outcomes as retrograde OMB. The bypass configuration choice should be predicated on patient presentation, anatomy, physiology, and surgeon preference; however, an antegrade configuration may provide a lower risk of reintervention.