Computed tomography angiography and magnetic resonance angiography imaging of the mesenteric vasculature

Superior mesenteric artery revisited using magnetic resonance angiography

PURPOSE

We aimed to examine the superior mesenteric artery in detail by magnetic resonance angiography to provide an alternative to other imaging methods, to reduce the exposure time of patients and physicians to X-rays and the time spent in catheter angiography, to determine the variations, positions, and locations of the celiac trunk, and to provide detailed information for surgeons and interventional radiologists using this method.

METHODS

The procedures were approved by the Kocaeli University Medical School Non-Interventional Clinical Research Ethics Committee (10.04.2023, approval number: 2021/51). MR angiography images of 185 patients with abdominal imaging in PACS (Picture Archiving Communication Systems) were retrospectively registered. The level of origin of the superior mesenteric artery according to the vertebral column, angle of origin, distance between the superior mesenteric artery and branches of the abdominal aorta, and branching pattern of the superior mesenteric artery were evaluated. Parameters were evaluated according to gender and age using SPSS version 25.

RESULTS

The distance between superior mesenteric artery-inferior mesenteric artery and superior mesenteric artery-aortic bifurcation in males was higher than in females, and the difference was statistically significant. In females and the whole study group, a low, positive and significant relationship was found between age and superior mesenteric artery-sagittal angle. The most common origin site for the superior mesenteric artery, according to the vertebral column was found to be at L1 middle for males and L1 upper for females. The most common superior mesenteric artery branching pattern was classical type in both genders.

CONCLUSION

Individual evaluation of the superior mesenteric artery could reduce the risks during surgical interventions, considering the relationship of the superior mesenteric artery, especially with distally located vessels, and the gender differences for the angle of origin. Furthermore, considering that interventional radiologists choose the catheter according to the angle of origin of the artery during catheter angiography procedures, individual evaluation of patients taking into account gender and age is of utmost importance.

Guidelines on the diagnosis, treatment and management of visceral and renal arteries aneurysms: a joint assessment by the Italian Societies of Vascular and Endovascular Surgery (SICVE) and Medical and Interventional Radiology (SIRM)

The objective of these Guidelines is to provide recommendations for the classification, indication, treatment and management of patients suffering from aneurysmal pathology of the visceral and renal arteries. The methodology applied was the GRADE-SIGN version, and followed the instructions of the AGREE quality of reporting checklist. Clinical questions, structured according to the PICO (Population, Intervention, Comparator, Outcome) model, were formulated, and systematic literature reviews were carried out according to them. Selected articles were evaluated through specific methodological checklists. Considered Judgments were compiled for each clinical question in which the characteristics of the body of available evidence were evaluated in order to establish recommendations. Overall, 79 clinical practice recommendations were proposed. Indications for treatment and therapeutic options were discussed for each arterial district, as well as follow-up and medical management, in both candidate patients for conservative therapy and patients who underwent treatment. The recommendations provided by these guidelines simplify and improve decision-making processes and diagnostic-therapeutic pathways of patients with visceral and renal arteries aneurysms. Their widespread use is recommended.

Ultra-short Echo-time MR Angiography Combined with a Modified Signal Targeting Alternating Radio Frequency with Asymmetric Inversion Slabs Technique to Assess Visceral Artery Aneurysm after Coil Embolization

Contrast-enhanced CT and MR angiography are widely used for follow-up of visceral artery aneurysms after coil embolization. However, potential adverse reactions to contrast agents and image deterioration due to susceptibility artifacts from the coils are major drawbacks of these modalities. Herein, we introduced a novel non-contrast-enhanced MR angiography technique using ultra-short TE combined with a modified signal targeting alternating radio frequency with asymmetric inversion slabs, which could provide a serial hemodynamic vascular image with fewer susceptibility artifacts for follow-up after coil embolization.

Factors associated with the need for long-term total parenteral nutrition in survivors of acute superior mesenteric artery occlusion

BACKGROUND

Acute superior mesenteric artery (SMA) occlusion is an uncommon condition associated with high mortality. If extensive bowel resection is performed for patients with acute SMA occlusion and the patient survives, long-term total parenteral nutrition (TPN) may be needed due to short bowel syndrome. This study examined factors associated with the need for long-term TPN after the treatment of acute SMA occlusion.

METHODS

We retrospectively analyzed 78 patients with acute SMA occlusion. Patients were abstracted from a Japanese database from institutions with at least 10 patients with acute SMA occlusive disease from January 2015 through December 2020 RESULTS: Among the initial cohort there were 41/78 survivors. Of these, 14/41 (34%) required permanent TPN who were compared with those who did not require long-term TPN (27/41, 66%). Compared to patients in the non-TPN group, those in the TPN group had significantly shorter remaining small intestine (90.7 cm vs. 218 cm, P<0.01), more patients with time from onset to intervention >6 hours (P=0.02), pneumatosis intestinalis on enhanced computed tomography scan (P=0.04), ascites (Odds Ratio 11.6, P<0.01), and a positive smaller superior mesenteric vein sign (P= 0.03). These were considered significant risk factors for needing long-term TPN. Age, gender, underlying disease, presence of peritoneal sign, presence of shock requiring vasopressors, site of obstruction (proximal vs. distal), and initial treatment (surgery vs. interventional radiology vs. thrombolytic therapy) were not significantly different between the two groups. Long-term TPN was significantly associated with longer hospital stay (52 vs. 35 days, P=0.04). Multivariate analysis identified the presence of ascites as an independent risk factor for needing long-term TPN.

CONCLUSION

The need for permanent TPN after treatment of acute SMA occlusion is significantly associated with longer hospital stay, longer time to intervention, and characteristic imaging findings (pneumatosis intestinalis, ascites, Smaller SMV sign). Ascites is an independent risk factor.

LEVEL OF EVIDENCE

III.

Radiological predictive factors of transmural intestinal necrosis in acute mesenteric ischemia: systematic review and meta-analysis

OBJECTIVE

Transmural intestinal necrosis (TIN) is related to high mortality in patients with acute mesenteric ischemia (AMI). Radiological predictive factors of TIN in AMI remains controversial. This study aimed to identify the CT-based predictive factors of TIN in AMI.

METHODS

EMBASE and PUBMED were searched for publications predicting TIN using radiological features. Quality Assessment of Diagnostic Accuracy Studies-2 was used to assess the methodological quality of individual studies. Data were presented in terms of diagnostic odds ratio (DOR), sensitivity, specificity, and 95% confidence interval (CI). The random-effects models were used for the meta-analysis.

RESULTS

Eleven studies including 1037 cases with AMI were considered. The meta-analysis showed that bowel wall thinning (DOR = 13.10; 95% CI: 3.71, 46.25), decreased or absent bowel wall enhancement (DOR = 5.77; 95% CI: 2.95, 11.30), bowel dilation (DOR = 3.23; 95% CI: 2.03, 5.15), pneumatosis intestinalis (DOR = 5.78; 95% CI: 2.24, 14.95), porto-mesenteric venous gas (DOR = 5.36; 95% CI: 2.14, 13.40), and arterial occlusive AMI (DOR = 2.66; 95% CI: 1.53, 4.63) were risk factors for predicting TIN. Bowel wall thinning and porto-mesenteric venous gas displayed high specificity to diagnose TIN (98%, 95%, respectively). The subgroup analysis showed that decreased or absent bowel wall enhancement (DOR = 8.23; 95% CI: 4.67, 14.51) and bowel dilation (DOR = 3.14; 95% CI: 1.55, 6.39) were predictors of TIN in venous occlusive AMI, which were not related to TIN in arterial-origin AMI.

CONCLUSIONS

For predicting TIN, there are specific radiological features. The radiological predictors of TIN may differ according to the various causes of AMI. Future primary studies should further evaluate the relationships between radiological signs and TIN based on different etiologies.

KEY POINTS

• Bowel wall thinning, decreased or absent bowel wall enhancement, bowel dilation, pneumatosis intestinalis, porto-mesenteric venous gas, and arterial occlusive AMI were risk factors for predicting TIN. • Decreased or absent bowel wall enhancement and bowel dilation were predictors of TIN in venous occlusive AMI, which were not related to TIN in arterial-origin AMI.

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.

MRI for the Detection of Small Bowel Ischemic Injury in Arterial Acute Mesenteric Ischemia: Preclinical Study in a Porcine Model

BACKGROUND

MRI is the reference for the diagnosis of arterial cerebral ischemia, but its role in acute mesenteric ischemia (AMI) is poorly known.

PURPOSE

To assess MRI detection of early ischemic bowel lesions in a porcine model of arterial AMI.

STUDY TYPE

Prospective/cohort.

ANIMAL MODEL

Porcine model of arterial AMI obtained by embolization of the superior mesenteric artery (seven pigs).

FIELD STRENGTH/SEQUENCE

A 5-T. T1 gradient-echo-weighted-imaging (WI), half-Fourier-acquisition-single-shot-turbo-spin-echo, T2 turbo-spin-echo, true-fast-imaging-with-steady-precession (True-FISP), diffusion-weighted-echo-planar (DWI).

ASSESSMENT

T1-WI, T2-WI, and DWI were performed before and continuously after embolization for 6 hours. The signal intensity (SI) of the ischemic bowel was assessed visually and quantitatively on all sequences. The apparent diffusion coefficient (ADC) was assessed.

STATISTICAL TESTS

Paired Student's t-test or Mann-Whitney U-test, significance at P < 0.05.

RESULTS

One pig died from non-AMI-related causes. The remaining pigs underwent a median 5 h53 (range 1 h24-6 h01) of ischemia. Visually, the ischemic bowel showed signal hyperintensity on DWI-b800 after a median 85 (57-276) minutes compared to the nonischemic bowel. DWI-b800 SI significantly increased after 2 hours (+19%) and the ADC significant decrease within the first hour (-31%). The ischemic bowel was hyperintense on precontrast T1-WI after a median 87 (70-171) minutes with no significant quantitative changes over time (P = 0.46-0.93). The ischemic bowel was hyperintense on T2-WI in three pigs with a significant SI increase on True-FISP after 1 and 2 hours.

DATA CONCLUSION

Changes in SI and ADC can be seen early after the onset of arterial AMI with DWI. The value of T2-WI appears to be limited.

EVIDENCE LEVEL

1 TECHNICAL EFFICACY: Stage 2.

Imaging of Bowel Ischemia: An Update, From the AJR Special Series on Emergency Radiology

Acute mesenteric ischemia is a life-threatening condition that results from abrupt reduction in or cessation of blood flow to the bowel. Characterized by nonspecific abdominal symptoms, mesenteric ischemia is infrequently encountered and commonly misdiagnosed, with potentially catastrophic consequences. Prompt clinical diagnosis and early implementation of therapeutic interventions are critical to improving patient outcomes. Because cross-sectional imaging plays a key role in the diagnosis of mesenteric ischemia, radiologists must be familiar with the varied imaging manifestations of intestinal ischemia. Thus, the objectives of this article are to review the various types and common causes of mesenteric ischemia and to describe its spectrum of multimodality imaging findings, with special attention to novel imaging techniques and emerging diagnoses.

Acute mesenteric ischemia: updated guidelines of the World Society of Emergency Surgery

Acute mesenteric ischemia (AMI) is a group of diseases characterized by an interruption of the blood supply to varying portions of the intestine, leading to ischemia and secondary inflammatory changes. If untreated, this process may progress to life-threatening intestinal necrosis. The incidence is low, estimated at 0.09-0.2% of all acute surgical admissions, but increases with age. Although the entity is an uncommon cause of abdominal pain, diligence is required because if untreated, mortality remains in the range of 50%. Early diagnosis and timely surgical intervention are the cornerstones of modern treatment to reduce the high mortality associated with this entity. The advent of endovascular approaches in parallel with modern imaging techniques is evolving and provides new treatment options. Lastly, a focused multidisciplinary approach based on early diagnosis and individualized treatment is essential. Thus, we believe that updated guidelines from World Society of Emergency Surgery are warranted, in order to provide the most recent and practical recommendations for diagnosis and treatment of AMI.

Early Identification of Chronic Mesenteric Ischemia with Endoscopic Duplex Ultrasound

Introduction

Due to diagnostic delay, chronic mesenteric ischemia (CMI) is underdiagnosed. We assumed that the patients suspected of CMI of the atherosclerotic origin or median arcuate ligament syndrome (MALS) could be identified earlier with endoscopic duplex ultrasound (E-DUS).

Patients and Methods

Fifty CMI patients with CTA-verified stenosis of either ≥50% and ≥70% of celiac artery (CA) and superior mesenteric artery (SMA) were examined with E-DUS and transabdominal duplex ultrasound (TA-DUS). Peak systolic velocities (PSV) of ≥200cm/s and ≥275cm/s for CA and SMA, respectively, were compared with CTA. Subgroup analysis was performed for the patients with (n=21) and without (n=29) prior revascularization treatment of CMI. The diagnostic ability of E-DUS and TA-DUS was tested with crosstabulation analysis. Receiver operating characteristics (ROC) curve analysis was performed, and the area under the curve (AUC) was calculated to investigate the test accuracy.

Results

In the patients with ≥70% stenosis, E-DUS had higher sensitivity than TA-DUS (91% vs 81% for CA and 100% vs 92% for SMA). AUC for SMA ≥70% in E-DUS was 0.75 and with TA-DUS 0.68. The sensitivity of E-DUS for CTA-verified stenosis ≥70% for CA was 100% in the patients without prior treatment. E-DUS demonstrated higher sensitivity than TA-DUS for both arteries with stenosis ≥50% and ≥70% in the treatment-naive patients.

Conclusion

E-DUS is equally valid as TA-DUS for the investigation of CMI patients and should be used as an initial diagnostic tool for patients suspected of CMI.

A Shifting Trend Towards Endovascular Intervention in the Treatment of Acute Mesenteric Ischemia

Background

Acute mesenteric ischemia (AMI) is a vascular emergency with a quite low incidence, but it is associated with disproportionately more severe morbidity and mortality. The aim of this study was to assess the current trend in the treatment of AMI and to see if endovascular intervention is an effective treatment modality in the selected group of patients.

Methods

A retrospective review of patients admitted with AMI between 2007 and 2018 was performed. Outcome measures were length of stay (LOS) at hospital and intensive care unit (ICU), and post-treatment mortality.

Results

A total of 98 patients with AMI were admitted during the study period. Patients undergoing endovascular treatment compared with surgery were younger (62.9 ± 13.7 years vs. 69.5 ± 12.8 years; p = 0.01). Shorter LOS in hospital and ICU was observed for those treated with endovascular approach (6.8 ± 3.4 and 3.25 ± 0.5 days) compared to the surgical group (25 ± 8.6 and 12.8 ± 26.8 days; p < 0.001). Out of 39 patients requiring ICU admission, 48.7% were surgically treated and 10.2% underwent endovascular intervention (p < 0.001). Mortality associated with surgery was 30.6% compared to only 6.6% with endovascular intervention (p < 0.001). Between 2007 and 2012, only one patient underwent endovascular intervention and 20 underwent surgery compared to 14 patients treated with endovascular approach and 16 with surgery between 2013 and 2018.

Conclusion

In this non-randomized, retrospective case series, patients with endovascular treatment fared clinically better and the intervention was found to be safe and feasible in the selected group of patients. We suggest a preference for this modality where possible. At our hospital, a trend favoring this approach is apparent during the last six years.

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.

Chronic mesenteric ischaemia presenting as possible large bowl malignancy: an easily overlooked differential diagnosis

An 80-year-old woman presented to a regional emergency department with postprandial pain, weight loss and diarrhoea for 2 months and a Computed Tomography (CT) report suggestive of descending colon malignancy. Subsequent investigations revealed the patient to have chronic mesenteric ischaemia (CMI) with associated bowel changes. She developed an acute-on-chronic ischaemia that required emergency transfer, damage control surgery and revascularisation. While the patient survived, this case highlights the importance of considering CMI in elderly patients with vague abdominal symptoms and early intervention to avoid potentially catastrophic outcomes.

Predictors and risk factors for intestinal necrosis in patients with mesenteric ischemia

Background

Mesenteric ischemia results in blood flow that is insufficient to meet metabolic demands and subsequent dysfunction of visceral organs, including arterial obstruction and venous thrombosis. Sustained mesenteric ischemia exhausts the ability of capillaries to provide oxygen and initiate an inflammatory reaction, and eventually leads to intestinal mucosal necrosis, a serious and potentially life-threatening condition. Therefore, it is essential that the predictors and risk factors for intestinal necrosis in patients with mesenteric thrombus are explored.

Methods

This study retrospectively enrolled 41 patients with mesenteric ischemia (including mesenteric vein embolism, mesenteric artery thrombosis, and portal vein thrombosis) who were admitted to the Department of Gastrointestinal Surgery, Beijing Tsinghua Changgung Hospital between May 2016 and October 2019; of the patients, 18 were further diagnosed with intestinal necrosis. Comparisons of symptoms, computed tomography angiography (CTA) features, and laboratory examination results were performed between mesenteric ischemia patients with and without intestinal necrosis.

Results

White blood cell count showed an excellent predictive ability for intestinal necrosis in patients with mesenteric ischemia, with an area under the receiver operating characteristic (ROC) curve of 0.772 (P=0.009). The four CTA features [pneumatosis (P=0.016), intestinal swelling (P=0.006), ascitic fluid (P<0.001), and decreased intestinal wall enhancement (P=0.004)] differed significantly between patients with and without intestinal necrosis. Peritonitis showed a strong association with intestinal necrosis (P=0.006) in the univariate analysis, and multivariate analysis further showed their association [odds ratio (OR): 8.53; 95%CI: 1.46-49.81; P=0.017].

Conclusions

White blood cell count is a potential predictor of intestinal necrosis. Peritonitis is a possible risk factor for intestinal necrosis in patients with mesenteric ischemia. A multi-center prospective study with a larger sample size needs to be performed to further investigate these findings.

Ultrashort echo time time-spatial labeling inversion pulse magnetic resonance angiography with denoising deep learning reconstruction for the assessment of abdominal visceral arteries

Current contrast-enhanced magnetic resonance angiography (MRA) and non-contrast-enhanced balanced steady-state free precession (bSSFP) MRA cause susceptibility artifacts from metallic devices in assessing endovascular visceral-artery interventions. The aims of this study are to investigate and compare image quality (IQ) and susceptibility artifacts of three-dimensional (3D) ultrashort echo time (UTE) time-spatial labeling inversion pulse (Time-SLIP) with those of 3D bSSFP Time-SLIP and to assess denoising deep learning reconstruction (dDLR) for the improvement of the signal-to-noise ratio (SNR) in 3D UTE with sparse sampling in phantoms and human subjects. This is a prospective type of study. Pulsatile glycerin-water flow phantom with platinum-tungsten-alloy coil, stainless-steel, nitinol, and cobalt-alloy stents were used. Ten healthy volunteers (seven males) and three patients (two males) were included in this study. 3D UTE Time-SLIP and 3D bSSFP Time-SLIP at 3T were used. The phantom-based study compared the signal-intensity ratio of the device levels (SR_device ) and distal segments (SR_distal ) to the proximal segments. The volunteer-based study measured SNR, contrast ratio (CR), and IQ. The patient study evaluated local artifacts from metallic devices. Statistical tests included paired t-tests, Wilcoxon-signed rank tests, and Kruskal-Wallis tests. In the phantom-based study, SR_device was small with UTE Time-SLIP, except the stainless-steel stent. SR_distal was greater (49.1%-90.4%) on bSSFP images than UTE images (-11.1% to 9.6%). Among volunteers, dDLR in UTE images improved SNR (p < 0.05) and IQ (p < 0.05), but CR was unaffected. UTE Time-SLIP showed inferior SNR and IQ than bSSFP Time-SLIP in images with and without dDLR (p < 0.05 for each). However, among patients, UTE Time-SLIP showed reduced metal artifacts compared to bSSFP Time-SLIP. Irrespective of the lower SNR and IQ of 3D UTE Time-SLIP than those of 3D bSSFP Time-SLIP, the former appeared to better depict flow after stenting or coiling. This indicates the potential of 3D UTE Time-SLIP to provide suitable diagnostic images of target vessels. dDLR improved SNR with reducing artifacts related to radial sampling, while maintaining the contrast. LEVEL OF EVIDENCE: 2. TECHNICAL EFFICACY STAGE: 2.

SCMR Position Paper (2020) on clinical indications for cardiovascular magnetic resonance

The Society for Cardiovascular Magnetic Resonance (SCMR) last published its comprehensive expert panel report of clinical indications for CMR in 2004. This new Consensus Panel report brings those indications up to date for 2020 and includes the very substantial increase in scanning techniques, clinical applicability and adoption of CMR worldwide. We have used a nearly identical grading system for indications as in 2004 to ensure comparability with the previous report but have added the presence of randomized controlled trials as evidence for level 1 indications. In addition to the text, tables of the consensus indication levels are included for rapid assimilation and illustrative figures of some key techniques are provided.

Mesenteric venous thrombosis complicating acute appendicitis: A case series

INTRODUCTION

Acute appendicitis is one of the most common surgical conditions. In the current era it rarely presents in association with mesenteric venous thrombosis. We present 4 cases of mesenteric venous thrombosis occurring in the setting of acute appendicitis.

METHODS

We performed a retrospective review of Mayo Enterprise clinical database for inpatients with a diagnosis of acute appendicitis and venous thrombosis related ICD-10 codes. Charts for patients with a diagnosis of mesenteric venous thrombosis and acute appendicitis were reviewed to identify demographic data, findings at presentation, and management patterns.

RESULTS

A total of 1,615 inpatients were identified with a principle diagnosis of acute appendicitis across the Mayo Enterprise from October 1st, 2015- March 31st, 2019. Four inpatients with a diagnosis of acute appendicitis were also noted to have a mesenteric venous thrombosis at presentation resulting in an incidence of 0.25 %. Mean duration of symptoms at presentation was 12.25 days. All patients with acute appendicitis and mesenteric venous thrombosis were initially managed with a heparin drip, antibiotics, and intravenous fluids. Ultimately, 3 of 4 patients underwent appendectomy.

CONCLUSION

Mesenteric venous thrombosis complicating acute appendicitis is rare and typically presents in a delayed fashion. Patients without evidence of non-viable bowel are typically treated initially with intravenous fluid resuscitation, antibiotics, bowel rest, and anticoagulation with a heparin drip.

Contrast-Enhanced CT for the Diagnosis of Acute Mesenteric Ischemia

OBJECTIVE. The purpose of this article is to provide an overview of the diagnostic and prognostic roles of CT in the management of acute mesenteric ischemia. CONCLUSION. Acute mesenteric ischemia is defined as inadequate blood supply to the gastrointestinal tract resulting in ischemic and inflammatory injury. The prognosis is poor without treatment. Contrast-enhanced CT has become the cornerstone of diagnosis to identify features of vascular disorders and of intestinal ischemic injury and to visualize bowel necrosis.

Retrospective Analysis and Systematic Review of Isolated Traumatic Dissections of the Celiac Artery

BACKGROUND

Isolated dissections of the celiac artery (CA) after blunt trauma are rarely described. This retrospective analysis and systematic review analyzes epidemiology, radiologic examinations, patterns of injuries, therapeutic measures, clinical courses, and outcomes.

METHODS

Retrospective analysis of polytraumatized patients admitted between 1997 and 2012 to a trauma center level I. Systematic literature search was carried out on pubmed.gov, eurorad.org, and google.com.

RESULTS

Isolated traumatic dissections of the CA had an incidence of 0.17% in a retrospective collective (n = 9). Mean age was 31.7 years in 6 male (66.7%) and 3 female (33.3%) patients. Systematic literature search identified 12 primary sources describing 13 males (100%) with a mean age of 41.3 years. Traffic accidents and falls were the most common causes of injury. An intimal flap (77.7%) and a thrombosed false lumen (59.1%) were the most common computed tomographic findings. Twenty-two patients were analyzed, and 16 patients were treated conservatively. The CA was bypassed in 2 symptomatic patients. One patient was treated with a stent. Two patients died because of massive bleeding, and 1 patient died because of liver failure. About 19 discharged patients were asymptomatic on follow-up. Long-term follow-up with magnetic resonance angiography showed stable dissections (n = 1), medium stenosis (n = 1), resolution of the dissection (n = 2), high-grade stenosis of the CA combined with a small pseudoaneurysm (n = 1), or occlusion of the CA with sufficient collateralization (n = 3). Pharmaceutical treatment was individualized with low-molecular-weight heparin, heparin, or warfarin, and acetylicsalicylic acid.

CONCLUSIONS

Traumatic CA dissections are mostly caused by traffic accidents and falls. Visceral perfusion should be monitored clinically and radiologically. Beginning visceral ischemia requires early invasive treatment. Endovascular and open surgery are possible options. Benefits of specific pharmaceuticals are still up for debate. Follow-up via magnetic resonance imaging or computed tomography angiography is essential to rule out vascular complications.

LEVEL OF EVIDENCE

III (Retrospective therapeutic study and systematic literature review).

Treatment of Superior Mesenteric Vein Thrombus by Catheter-Directed Thrombolysis

Contrast-enhanced computed tomography (CT) greatly improves the diagnosis of superior mesenteric vein (SMV) thrombosis, which presents as the unspecific symptom of abdominal pain. Prothrombotic states or thrombophilia and local intra-abdominal infections are major causes of SMV thrombosis. A 37-year-old Chinese woman was diagnosed with SMV and portal vein thrombosis. The patient was initially given 40 mg of heparin sodium every 12 hr and 80,0000 U/day of urokinase using superior mesenteric artery angiography. The abdominal pain was not relieved after treatment. The patient then underwent open surgery, where an ileal branch of the SMV was punctured, a 4F sheath was introduced into the vein toward the portal vein, and a 20-cm Unifuse catheter was placed inside the thrombus for further thrombolysis. Both heparin sodium and urokinase were infused through catheter-directed thrombolysis. The patient's symptoms then gradually resolved.

The Superior Mesenteric Artery: From Syndrome in the Young to Vascular Atherosclerosis in the Old

This review is directed at increasing awareness of two diverse rare upper gastrointestinal problems that occur at opposite ends of the age spectrum and are difficult to diagnose and treat. The Superior Mesenteric Artery Syndrome (SMAS) likely involves a young patient, especially female, and is especially associated with rapid weight loss, resulting in relative strangulation of the duodenum by a narrowing of the angle between the Superior Mesenteric Artery (SMA) and the aorta. On the other hand, atherosclerosis of the SMA is associated most likely with postprandial upper intestinal ischemia and abdominal pain occurs in the elderly at high risk for cardiovascular (CV) disease. Medical management of the SMAS in the young involves good alimentation and weight gain to overall increase the intestinal fat pad. Medical management of SMA atherosclerotic ischemia in the elderly is directed at marked lipid lowering with atherosclerotic plaque stabilization or even regression. If needed, surgery for SMAS can be attempted laparoscopically with duodenojejunoscopy which is the most popular procedure but there are also more conservative possibilities that avoid division of the duodenum. In addition, sometimes direct vision is needed to successfully operate on SMAS. If surgery is needed for SMA atherosclerotic ischemia, it is usually attempted endoscopically with angioplasty and stent placement. Most important, in the case of these two rare clinical entities, is that the clinician have a suspicion of their presence when indicated so that the young or old patient can be spared unnecessary suffering and return to good health in a timely fashion.

Necessity of revascularization for acute mesenteric ischemia in symptomatic patients with spontaneous isolated dissection of the superior mesenteric artery

Objectives

We evaluated the necessity of revascularization for acute mesenteric ischemia in symptomatic patients with spontaneous isolated dissection of the superior mesenteric artery.

Methods

This retrospective study included 28 consecutive, symptomatic patients with spontaneous isolated dissection of the superior mesenteric artery treated at our hospital between December 2005 and December 2017. Patients with concomitant aortic dissection were excluded. We reviewed the patients’ clinical presentation; laboratory evaluations; computed tomography findings, including the true lumen residual ratio (i.e., the minimum true lumen size compared to the diameter of the transverse section of the dissected artery) at the time of admission; the number of patients who were suspected of having bowel ischemia; and the number of patients who required surgical or endovascular treatment and their outcomes. Additionally, to evaluate the true lumen residual ratio in symptomatic patients with bowel ischemia, the true lumen residual ratio in those with abnormal laboratory data were compared with that in those without abnormal laboratory data. Initial true lumen residual ratio values were also compared with final values. Furthermore, we assessed the clinical details of patients who had bowel necrosis. Categorical variables were compared using the χ2 test or Fisher’s exact test, and continuous values were presented as either the mean ± standard deviation or median (interquartile range 25–75%). Variables were analyzed using Student’s t-test or the Mann–Whitney U test.

Results

The patients’ age ranged between 41 and 85 years, and 25 were men. Although nine patients were suspected of having acute mesenteric ischemia, only one underwent bowel resection. None of the patients had an indication for revascularization. The true lumen residual ratio of the nine patients with abnormal laboratory data were significantly lower than those of the 19 without abnormal laboratory data (10 [0–25]% vs. 40 [20–50]%, p = 0.005). The patient who underwent bowel resection had a true lumen residual ratio of 10%; however, there was no obvious abnormal laboratory data suggestive of bowel necrosis. Dissections were managed conservatively in all patients. True lumen residual ratio increased from initial value of 30 (10–48)% to 98 (60-100)%at the final imaging study ( p < 0.0001). There were no adverse events related to the mesenteric circulation during the follow-up period of 2–11 years.

Conclusions

Reintervention is rarely required for spontaneous isolated dissection of the superior mesenteric artery, even in symptomatic patients, and spontaneous resolution of the luminal compromise is the rule.

Aorto-mesenteric Bypass for the Treatment of Chronic Mesenteric Ischemia

Chronic mesenteric artery disease has a much lower incidence than the acute one, but it raises the same problems in terms of patient survival. The long-term outcomes for open surgery are crucial for the right choice of a particular technique. We present the case of a 39-year-old female patient with a history of total nephrectomy, chronic kidney failure, and hypertension, who presented in the Emergency Department with abdominal pain with high intensity, for which she was admitted to the General Surgery Department. Abdominal computed tomography angiography was performed, which indicated the diagnosis of partial upper mesenteric artery stenosis. The patient underwent surgery, during which a retrograde aorto-mesenteric bypass with a Gore-Tex 5 mm diameter prosthesis was performed. In situations where the endovascular approach fails or has no indication (multiple incidence lesions from the origin of the superior mesenteric artery), open surgery is the indication in chronic mesenteric ischemia.

Serological biomarkers for acute mesenteric ischemia

Acute mesenteric ischemia (AMI) defines a complex of conditions characterized by an interruption of the splanchnic circulation, leading to insufficient oxygen delivery or utilization to fill the metabolic needs of the visceral organs. Early diagnosis and immediate therapy are the cornerstones of early ischemia to reach a successful outcome and are necessary to reduce the high mortality. Although there is still lack of specific biomarkers to assist the diagnosis of AMI in clinical practice, there are several biomarkers with high specificity, may become a potential tools in early diagnosis of AMI, including intestinal fatty acid binding protein (I-FABP), a-glutathione S-transferase (a-GST), D-dimer, L- and D-lactate, citrulline, ischemia modified albumin, procalcitonin (PCT). However, they use in clinical limited duo to the many studies about these makers finished with small patient populations, and heterogeneous among these populations. This review describes the etiology of AMI, the current most studied promising biomarkers, the current research situation and future of biomarker research.

CT and MRI assessment of intestinal blood flow

The accuracy of multi-slice computed tomography (CT) in the diagnosis of acute mesenteric ischemia is very high, however, it cannot demonstrate the small embolus of blood vessels and abnormal intestinal blood flow. The intestinal blood flow in chronic mesenteric ischemia decreases whereas there are few morphology changes, which leads to a high misdiagnosis rate of CT and CT angiography. In addition, inflammatory bowel disease, intestinal tumors, and portal hypertension can be diagnosed definitely by conventional CT, but the hemodynamics and microcirculation in these conditions cannot be assessed, which affects the accuracy of clinical staging and the assessment of therapeutic effect. For intestinal diseases, especially mesenteric ischemia, therefore, it is needed not only to make CT morphologic diagnosis but also to further assess the abnormal intestinal blood flow. In recent years, more and more CT and magnetic resonance imaging (MRI)-related new techniques for assessing blood flow have emerged, including CT perfusion, spectral CT imaging, magnetic resonance perfusion imaging, and phase contrast MRI. This paper reviews the clinical application and progress of these techniques for assessing intestinal blood flow.

Stenosis of the celiac trunk is associated with anastomotic leak after Ivor-Lewis esophagectomy

Transthoracic esophagectomy with gastric tube formation is the surgical treatment of choice for esophageal cancer. The surgical reconstruction induces changes of gastric microcirculation, which are recognized as potential risk factors of anastomotic leak. This prospective observational study investigates the association of celiac trunk (TC) stenosis with postoperative anastomotic leak. One hundred fifty-four consecutive patients with esophageal cancer scheduled for Ivor-Lewis esophagectomy were included. Preoperative staging computed tomography (CT) was used to identify TC stenosis. Any narrowing of the lumen due to atherosclerotic changes was classified as stenosis. Percentage of stenotic changes was calculated using the North American Symptomatic Carotid Endarterectomy Trial formula. Multivariable analysis was used to identify possible risk factors for leak. The overall incidence of TC stenosis was 40.9%. Anastomotic leak was identified in 15 patients (9.7%). Incidence of anastomotic leak in patients with stenosis was 19.4% compared to 2.3% in patients without stenosis. Incidence of stenosis in patients with leak was 86.7% (13 of 15 patients) and significantly higher than 38.8% (54 of 139 patients) in patients without leak (P < 0.001). There was a significant difference in median degree of TC stenosis (50.0% vs 39.4%; P = 0.032) in patients with and without leak. In the multivariable model, TC stenosis was an independent risk factor for anastomotic leak (odds ratio: 5.98, 95% CI: 1.58-22.61). TC stenosis is associated with postoperative anastomotic leak after Ivor-Lewis esophagectomy. Routine assessment of TC for possible stenosis is recommended to identify patients at risk.

Neutrophil-to-lymphocyte ratio and mesenteric ischemia: can it predict the etiology of mesenteric ischemic at computed tomography?

OBJECTIVES

To assess the usefulness of the neutrophil-to-lymphocyte ratio (NLR) as a predictive factor of acute mesenteric ischemia (AMI) in patients presenting at the emergency department (ED) with acute abdominal pain.

METHODS

This is a retrospective case-control study of patients older than 16 years admitted to the ED with acute abdominal pain with CT and histologic confirmation. The study group corresponded to patients with abdominal CT with radiological signs of AMI. The control group corresponded to patients with non-AMI findings in abdominal CT. Association measurements of NLR with radiological signs were compared with a paired-sample t test, and multivariate regression performed to analyze potential correlations. To assess the diagnosis capacity of NLR, ROC curves were calculated.

RESULTS

A total of 61 patients were included (32 cases and 29 controls). The cases of AMI showed higher mortality (43.8% vs 6.9%, p < 0.01) and higher NLR on the limit of statistical significance (13.8 vs 8.7, p = 0.053). Patients with AMI due to occlusion of the superior mesenteric artery (SMA) showed a higher NLR (8.3 vs 22.3, p < 0.001). The area under the curve (AUC) of the NLR for AMI due to occlusion of the SMA was 0.88 (95% CI 0.7-1.0, p = 0.001). No patient with NLR < 5 presented AMI due to occlusion of the SMA. An NLR of 12.8 showed a sensitivity of 92% and a specificity of 74% for AMI due to occlusion of SMA.

CONCLUSIONS

The NLR is a useful parameter of AMI of arterial origin due to occlusion of the SMA; it can help the clinician to raise suspicion of this diagnosis and the interpreting radiologist in the acquisition protocol for the CT study and would alert for an early surgical treatment.

Superior Mesenteric Artery Pseudoaneurysms in Patients With Familial Adenomatous Polyposis-Associated Intra-abdominal Desmoids: Case Series

BACKGROUND

Rupture of a superior mesenteric artery pseudoaneurysm is a rare but potentially lethal complication in patients with familial adenomatous polyposis and desmoid disease.

OBJECTIVE

We report our experience in the management of such patients with a rare but significant and life-threatening condition.

DESIGN

This is a descriptive study of a small series of patients.

SETTINGS

Data were obtained from their medical charts and from the Cologene Database of the David G. Jagelman Polyposis Registry in the Sanford R. Weiss, M.D., Center for Hereditary Colorectal Cancer at the Cleveland Clinic Foundation.

PATIENTS

Of 227 patients with mesenteric desmoid disease, there were 4 cases of superior mesenteric artery pseudoaneurysm rupture.

MAIN OUTCOMES MEASURES

We reviewed the patients with mesenteric desmoid tumors in our desmoid registry. The registry is approved by the institutional review board of the Cleveland Clinic.

RESULTS

The patients were young (aged from 22 to 28 y at presentation), with otherwise minimal comorbidities. Two patients had a previous proctocolectomy and J-pouch, and 2 had a total colectomy and ileorectal anastomosis. Two patients had preemptive endoluminal stenting and fared better than the 2 who had damage control embolization. One patient died and, in the others, recovery was prolonged and complicated. Two of the 4 patients have ended up with a reasonable quality of life.

LIMITATIONS

We acknowledge that this is a rare complication of an uncommon disease and, as such, any case series will be limited by small numbers; therefore, a tailored approach is warranted when managing such complex patients.

CONCLUSIONS

We advocate an increased awareness of the possibility of visceral pseudoaneurysms in patients with familial adenomatous polyposis who have desmoid disease encasing the superior mesenteric artery. See Video Abstract at http://links.lww.com/DCR/A914.

Visceral Fibromuscular Dysplasia: From asymptomatic disorder to emergency

Fibromuscular dysplasia (FMD) is an idiopathic, segmental, non-atherosclerotic and non-inflammatory disease of the musculature of arterial walls, leading to stenosis of small and medium-sized arteries, mostly involving renal and cervical arteries. As a result of better and more systematic screening, it appears that involvement of the splanchnic vascular bed is more frequent than originally assumed. We review epidemiology, pathogenesis, clinical picture as well as diagnosis and treatment of visceral artery (VA) FMD. The clinical picture is very diverse, and diagnosis is based on CT-, MR- or conventional catheter-based angiography. Involvement of VAs generally occurs among patients with multi-vessel FMD. Therefore, screening for VA FMD is advised especially in renal artery (RA) FMD and in case of aneurysms and/or dissections. Treatment depends on the clinical picture. However, the level of evidence is low, and much of the common practice is extrapolated from visceral atherosclerotic disease.

Evaluation of direct oral anticoagulants and vitamin K antagonists in mesenteric venous thrombosis

BACKGROUND/AIM

Mesenteric venous thrombosis is a rare lethal disease. The main aim of the present study was to evaluate clinical efficacy and safety of direct oral anticoagulants and vitamin K antagonists in mesenteric venous thrombosis patients.

METHODS

Retrospective study of 102 mesenteric venous thrombosis patients treated between 2004 and 2017 at a center with a conservative medical first approach. Median clinical follow-up was 4 years.

RESULTS

Computed tomography showed successful recanalization of thrombosis in 71% of patients on vitamin K antagonists and 69% of patients on direct oral anticoagulants ( p = 0.88). Overall major and esophageal variceal bleeding rate was 14.7% and 2.9%, respectively. No difference in major bleeding ( p = 0.54) was found between vitamin K antagonists and direct oral anticoagulants. No mesenteric venous thrombosis recurrence occurred during follow-up, and one venous thromboembolism occurred after cessation of anticoagulation.

CONCLUSION

Anticoagulation with direct oral anticoagulants and vitamin K antagonists was efficient in patients with mesenteric venous thrombosis. Bleeding complications was a concern during treatment in both groups.

Progress in multi-slice CT diagnosis of atherosclerotic mesenteric ischemia

The incidence of atherosclerotic mesenteric ischemia increases gradually with the aging of the population and rising of the incidence of atherosclerosis. In the last decade, mesenteric atherosclerosis has become the most common cause of acute and chronic mesenteric ischemia. Atherosclerotic mesenteric ischemia often presents with an insidious onset and slow evolvement, and is easily overlooked. The CT manifestations of advanced mesenteric ischemia are classic with high diagnostic accuracy, and the specific findings of CT angiography include: thromboembolus and stenotic or occlusive mesenteric artery in acute stage, single or multiple calcified or non-calcified plaques, and multiple stenotic and stiff mesenteric arteries with reduced branching vessels in chronic stage. Early mesenteric ischemia, however, has no or nonspecific CT sign and is difficult to detect. This article discusses the diagnostic value and limitations of multi-slice CT in atherosclerotic mesenteric ischemia as well as some new imaging techniques for diagnosis of this condition.

Acute mesenteric ischemia: guidelines of the World Society of Emergency Surgery

Acute mesenteric ischemia (AMI) is typically defined as a group of diseases characterized by an interruption of the blood supply to varying portions of the small intestine, leading to ischemia and secondary inflammatory changes. If untreated, this process will eventuate in life threatening intestinal necrosis. The incidence is low, estimated at 0.09–0.2% of all acute surgical admissions. Therefore, although the entity is an uncommon cause of abdominal pain, diligence is always required because if untreated, mortality has consistently been reported in the range of 50%. Early diagnosis and timely surgical intervention are the cornerstones of modern treatment and are essential to reduce the high mortality associated with this entity. The advent of endovascular approaches in parallel with modern imaging techniques may provide new options. Thus, we believe that a current position paper from World Society of Emergency Surgery (WSES) is warranted, in order to put forth the most recent and practical recommendations for diagnosis and treatment of AMI. This review will address the concepts of AMI with the aim of focusing on specific areas where early diagnosis and management hold the strongest potential for improving outcomes in this disease process.

Some of the key points include the prompt use of CT angiography to establish the diagnosis, evaluation of the potential for revascularization to re-establish blood flow to ischemic bowel, resection of necrotic intestine, and use of damage control techniques when appropriate to allow for re-assessment of bowel viability prior to definitive anastomosis and abdominal closure.

Multi-slice CT for diagnosis of acute mesenteric ischemia

Acute mesenteric ischemia (AMI) has an acute onset and a high mortality rate with nonspecific clinical presentation and is difficult to diagnose. In recent years, due to fast submillimeter scanning and subtle three-dimensional reconstruction, 64-row multi-slice CT can distinctly demonstrate the stenosis and occlusion of the mesenteric vessels, assess the alteration of morphology and blood perfusion of the intestinal wall and mesentery, and promptly and accurately diagnose AMI, intestinal infarction and its etiology. Therefore, CT has become the most valuable and first-line diagnostic modality for evaluating patients with suspected AMI. AMI has different and complicated CT findings due to different etiology, pathology, extent, position, as well as with or without mural hemorrhage or infection. In this article, we systematically review the multi-slice CT manifestations of AMI and its diagnostic value in various causes of AMI in different stages.

Mesenteric venous thrombosis

OBJECTIVE

This review explores the current literature on the natural history, diagnosis, and management of mesenteric venous thrombosis (MVT) in the modern era.

METHODS

A review of the contemporary literature from 1997 to 2016 on MVT and its pathogenesis, diagnosis, and treatment was performed.

RESULTS

MVT is an insidious and lethal disease associated with acute mesenteric ischemia. The prevalence of MVT has increased sharply during the past two decades commensurate with an increase in radiographic imaging for abdominal complaints. The optimal treatment of and approach to MVT is controversial, given the poorly understood natural history of this rare disease. Both endovascular and open surgical strategies in addition to systemic anticoagulation have been used as adjuncts to treat MVT with limited success. Despite advances in treatment, mortality associated with MVT is still high. Furthermore, recent studies have shown that failure to recanalize the portomesenteric venous system leads to an increased risk for development of sequelae of portal hypertension.

CONCLUSIONS

MVT is a challenging disease to treat, given the difficulty in establishing a prompt initial diagnosis and the inability to reliably monitor patients for evidence of impending bowel infarction. Careful selection of patients for endovascular, open, or hybrid approaches is key to achieving improved outcomes. However, the paucity of prospective data and our evolving understanding of the natural history of MVT make consensus treatment strategies difficult to ascertain.

Anatomic and radiologic review of chronic mesenteric ischemia and its treatment

Chronic mesenteric ischemia (CMI) is a vascular occlusive disease process that generally affects the elderly population. Clinical presentation occurs when two of the three mesenteric arteries are affected and includes non-specific abdominal pain and weight loss. The most common cause of CMI is atherosclerotic arterial occlusion. The aim of this review is to present the vascular anatomy of the mesenteric arterial circulation including the different collateral pathways. The imaging findings and the different treatment options with a brief review of the literature is presented.