Outcomes of Treatment Strategies for Isolated Spontaneous Dissection of the Superior Mesenteric Artery: A Systematic Review

Systematic review and meta-analysis of current evidences in endograft therapy vs. medical treatment for Spontaneous Isolated Superior Mesenteric Artery Dissection

OBJECTIVE

Endovascular stent therapy (EST) for spontaneous isolated superior mesenteric artery dissection (SISMAD) is gaining popularity, yet the treatment strategy - BMT or EST - remains debatable.

METHODS

A meta-analysis examined all randomized trials and observational studies exploring the relative merits and potential risks of EST vs. BMT in treating SISMAD patients. Key outcomes included early and long-term adverse effects, with odds ratios (ORs) and 95% confidence intervals (CI) calculated. A random- or fixed-effects model was selected according to a 50% heterogeneity threshold.

RESULTS

9 observational studies involving a total of 672 SISMAD patients (303 EST), met our selection criteria. We discovered no noteworthy distinctions between the EST group and the BMT group in terms of early symptoms' alleviation, reinterventions, or all-cause mortality. However, patients receiving EST management will be hospitalized longer than those receiving BMT (EST: 13.2 ± 5.1 months vs. BMT: 7.0 ± 2.2 months, P < 0.01). In the long run, EST was found to significantly contribute to a higher rate of complete remodeling (OR: 4.53, CI: 3.01 ~ 6.81, P < 0.01; heterogeneity, I2 = 50%) and a lower incidence of aneurysm formation (OR: 0.19, CI: 0.06 ~ 0.6, P < 0.01; heterogeneity, I2 = 0%) than BMT. However, there are no significant differences between ESTand BMTin terms of all-cause mortality, recurrent syndrome, reintervention, and SMA stenosis or occlusion.

CONCLUSION

EST can effectively prevent the formation of aneurysmal dissection and improve SISMAD remodeling. Both EST and BMT are similar in reducing long-term mortality, recurrent symptoms, severe SMA stenosis or occlusion, and the need for reintervention in patients with SISMAD.

Hybrid repair of symptomatic superior mesenteric artery dissection, utilizing open septectomy

We present a case of acute isolated superior mesenteric artery dissection with symptomatic bowel malperfusion requiring surgical intervention. We recommend clinicians and surgeons maintain a high clinical suspicion for mesenteric ischemia in patients presenting with isolated superior mesenteric artery dissection and describe a hybrid open surgical/endovascular approach that can safely be utilized in patients requiring intervention.

Secondary Hemorrhagic Shock Due to Spontaneous Isolated Dissection of the Superior Mesenteric Artery Branch

Spontaneous isolated dissection of the superior mesenteric artery (SIDSMA) is a rare condition, particularly when complicated by hemorrhagic shock. This case report describes the discovery of SIDSMA in an 88-year-old woman through CT angiography. The patient initially presented with acute abdominal pain, nausea, and diarrhea, which later progressed to hemorrhagic shock. After fluid resuscitation, the patient underwent successful endovascular treatment.

Natural history of visceral branch artery dissections and the influence of concurrent aortic dissection on overall and intervention-free survival

OBJECTIVE

Visceral branch artery dissection (VBAD) is uncommon and may occur with or without an associated aortic dissection (AD). We hypothesized that isolated VBAD would have a more benign clinical course than those with concurrent AD and compared survival outcomes stratified based on aortic involvement.

METHODS

VBAD over a 5-year period were identified using International Classification of Diseases codes. Data related to patient demographics, comorbid conditions, clinical presentation, management (including procedural interventions), and survival were obtained from medical records. Anatomic imaging studies were reviewed to characterize anatomy, including the presence or absence of concurrent AD. Overall survival and intervention-free survival were evaluated using Kaplan-Meier and Cox proportional hazards models.

RESULTS

A total of 299 VBAD were identified, 174 of which were isolated VBAD and 125 were associated with concurrent AD. Seventy-one percent of patients were men, 77% were White, and 85% were non-Hispanic. The mean age was 61.1 ± 14.4 years. The mean follow-up was 53.2 ± 50.0 months. The estimated overall survival was 88.2% and the estimated overall intervention-free survival was 55.6% at 12 months. Isolated VBAD had better overall survival than those with concurrent AD (69.2% vs 32.4%; P < .001). Concurrent AD was also associated with inferior intervention-free survival (57.5% vs 7.3%; P < .001). Acute presentation was associated with decreased intervention-free survival (86.1% vs 13.4%; P < .001). Acute presentation was also associated with decreased overall survival in patients with isolated VBAD (60.8% vs 80.0% at 180 months; P < .001) and inferior intervention-free survival (48.4% vs 69.5% at 180 months; P < .001) in the subgroup of patients with isolated VBAD. Multivariable Cox models identified that age (hazard ratio [HR]: 1.05, standard deviation [SD]: 0.02; P = .001) was associated with inferior survival and renal dissections (HR: 3.08, SD: 0.99; P = .001) or mesenteric and renal dissections (HR: 3.39, SD: 1.44; P = .004) were associated with inferior intervention-free survival.

CONCLUSIONS

Isolated VBAD has superior overall and intervention-free survival to those associated with concurrent AD. The absence vs presence of aortic involvement is useful for risk stratification and may support tailored approaches to the frequency of imaging surveillance.

Midterm Results of the Conservative, Bare Stent, and Bare Stent-Assisted Coiling Treatments for Symptomatic Isolated Superior Mesenteric Artery Dissection

BACKGROUND

We compared the early and midterm (31, 3-63 months) outcomes of conservative treatment, bare stent treatment (BST), and bare stent-assisted coiling treatment (BSACT) to determine the most effective treatment for patients with symptomatic isolated superior mesenteric artery dissection (SISMAD).

METHODS

Consecutive patients with SISMAD admitted to the study hospital between January 2016 and December 2021 were included in this retrospective study. Their demographic data, clinical findings, treatment options, early outcomes, and follow-up results were analyzed.

RESULTS

A total of 121 patients were included in the study (23 with conservative treatment, 42 with BST, and 56 with BSACT). Symptoms were relieved in 91.3% of conservative patients, whereas all patients (100%) with BST or BSACT had symptom relief (P = 0.035). There was no significant difference in the length of hospital stay between the 2 endovascular treatments (P = 0.9051), but hospital stay was significantly shorter compared to conservative treatment (P < 0.0001). The cumulative rate of complete remodeling was 100% for BSACT versus 46.3% for BST (P < 0.0001) versus 42.9% for conservative patients (P < 0.0001). There were no significant differences between the last 2 groups (P = 0.3925). The prevalence of adverse events for abdominal pain recurrence and aneurysm formation was also significantly lower in the BSACT group at follow-up.

CONCLUSIONS

BSACT for SISMAD has a preferable early outcome. The cumulative complete remodeling rate and the event-free survival rate are satisfactory at midterm follow-up. BSACT is an effective approach for SISMAD.

Endovascular treatment of systematic isolated mesenteric artery dissection with a patent false lumen: Bare stents alone versus stent-assisted coiling

OBJECTIVES

Bare stent treatment and bare stent-assisted coiling treatment have not been directly compared in symptomatic isolated superior mesenteric artery dissection with a patent false lumen. Thus, we compared the early and mid-term outcomes of bare stent treatment and bare stent-assisted coiling treatment to determine the most effective remedy for patients with this condition.

METHODS

Consecutive patients diagnosed with systematic isolated superior mesenteric artery dissection with a patent false lumen admitted to the study hospital between January 2016 and December 2021 were enrolled in this retrospective study. Their demographic data, clinical findings, treatment options, early outcomes, and follow-up results were analyzed.

RESULTS

A total of 85 patients (83 men) were included. 34.1% (n = 29) adopted bare stent treatment and 65.9% (n = 56) underwent bare stent-assisted coiling treatment. The symptoms were relieved in all patients (100%) with bare stent treatment and bare stent-assisted coiling treatment. There was no significant difference in the length of hospital stay between the two endovascular treatments (p = 0.354). The cumulative complete remodeling rate was 100% in bare stent-assisted coiling treatment vs. 70.4% in bare stent treatment (p < 0.0001). The prevalence of adverse events for abdominal pain recurrence (none in BST or bare stent-assisted coiling treatment), and formation of the aneurysm (two in bare stent treatment, and none in bare stent-assisted coiling treatment) showed no significant difference at follow-up.

CONCLUSION

Both bare stent treatment and bare stent-assisted coiling treatment for symptomatic isolated superior mesenteric artery dissection with a patent false lumen have the same satisfying early outcome. In the midterm follow-up, bare stent-assisted coiling treatment has the higher cumulative complete remodeling rate which could be prioritized to treat this condition.

Isolated superior mesenteric artery dissection: An updated review of the literature

Isolated superior mesenteric artery dissection (ISMAD) is a rare but potentially life-threatening cause of acute abdominal pain. Owing to the availability of computed tomography angiography, more cases have been detected during screening for acute abdomen in recent years. With increasing knowledge of ISMAD, a better management strategy is being developed. To enhance our understanding and improve treatment outcomes of ISMAD, a systematic literature review was conducted with a focus on diagnosis and management strategies based on existing evidence.

Five-Year Results of Spontaneous Isolated Superior Mesenteric Artery Dissection from Two Teaching Hospitals in China

BACKGROUND

To present 5-year results of management on spontaneous isolated superior mesenteric artery dissection (SISMAD) from 2 teaching hospitals in China.

METHODS

The clinical data of 41 patients with SISMAD were retrospectively collected from 2 teaching hospitals between December 2016 and December 2021. Therapeutic methods mainly included open surgery, endovascular management, and conservative therapy. Patients' demographics, total number of WBC (White blood cell, WBC), the percentage of NEUT (Neutrophil), the level of CRP (C-reactive protein, CRP), duration of abdominal pain on admission, YOO classification of SISMAD, angle of superior mesenteric artery to abdominal aorta (ASA), length of hospital stays, and vascular remodeling rate of SMA between endovascular and conservative groups were analyzed.

RESULTS

A total of 41 patients with SISMAD were finally included in this study. Their average age was 53.4 ± 7.1 years old, ranging from 35 to 68 years old. Among these patients, 1 patient suffered emergent open surgery because of the intestinal necrosis. The other 40 patients were treated conservatively at first, but 13 of them were transitioned into endovascular management due to persistent abdominal pain. Regarding the imaging analysis, IIS and IVS types of YOO classification were more in the endovascular group (13 patients) than the conservative group (27 patients). The length of hospital stays (P = 0.003) and the vascular remodeling rate of SMA were significantly different between 2 groups (P = 0.002), while the time of abdominal pain on admission, the infection markers (WBC, CRP, NEUT) and ASA were not significantly different between the 2 groups.

CONCLUSIONS

In SISMAD, patients without any signs of peritonitis and intestinal necrosis may be treated conservatively firstly, and then transitioned into endovascular management if abdominal pain is not improved within 48 hr. IIS and IVS types of YOO classification should be alerted of this potential transition. But the optimal timing of transition required more clinical studies.

Acute Isolated Mesenteric Artery Dissection: Four Year Experience From a French Intestinal Stroke Centre

OBJECTIVE

This study aimed to report outcomes of patients with symptomatic acute isolated mesenteric artery dissection (IMAD) treated within a French intestinal stroke centre (ISC).

METHODS

All patients with symptomatic IMAD referred to the ISC from January 2016 to January 2020 were included prospectively. Patients with aortic dissection and asymptomatic IMAD were not included. The standardised medical protocol included anticoagulation and antiplatelet therapy, gastrointestinal resting, and oral antibiotics. Operations were considered for acute mesenteric ischaemia (AMI).

RESULTS

Among the 453 patients admitted to an ISC during the study period, 34 (median age, 53 years [41 - 67]; 82% men) with acute symptomatic IMAD were included. According to the classification of Yun et al., IMADs were reported as follows: type I (n = 7, 20%), type IIa (n = 6, 18%), type IIb (n = 15, 44%), and type III (i.e., complete superior mesenteric artery [SMA] occlusion; n = 6, 18%). Overall, nine (26%) patients had AMI (type I/II, n = 3; type III, n = 6). On initial computerised tomography angiogram, nine (26%) patients had an associated visceral arterial dissection or pseudoaneurysm. All patients with types I/II (n = 28, 82%) followed a favourable clinical course with conservative therapy, with no need for any operation. All patients with type III (n = 6, 18%) underwent urgent laparotomy with SMA revascularisation (open, n = 4; stenting, n = 1) and or bowel resection (early, n = 3; late, n = 1). Rates of intestinal resection and short bowel syndrome were 12% and 8.8%, respectively. After a median follow up of 26 months [18 - 42], recurrence of symptoms occurred in four (12%) patients and aneurysmal change in 14 (41%), with no re-intervention.

CONCLUSION

Although IMAD was associated with a high frequency of AMI, a standardised protocol produced a low rate of intestinal resection. Conservative therapy seems appropriate in types I/II patients, whereas urgent SMA revascularisation should aim to avoid intestinal resection or death in type III patients.

Management of Patients with Uncomplicated Symptomatic Isolated Mesenteric Artery Dissection: a Multicentre Experience

OBJECTIVE

Isolated mesenteric artery dissection (IMAD) is an increasingly diagnosed disease. However, multicentre studies to support clinical decision making are limited. This multicentre retrospective study aimed to investigate the characteristics, treatment options, and outcomes of IMAD.

METHODS

Data from consecutively enrolled patients with IMAD between October 2009 and May 2021 at three hospitals were collected retrospectively. One hundred and ninety uncomplicated symptomatic IMAD patients were divided into two groups: conservative (n = 141) and operative (n = 49). The costs, length of hospital stay, factors affecting outcomes, symptom relief, and complete remodelling of superior mesenteric artery (SMA) were analysed between the two groups.

RESULTS

Compared with patients who received operative treatment, patients receiving conservative treatment had shorter hospital stays (8.2 ± 4.6 vs. 11.9 ± 6.4 day, p < .020) and lower hospital costs (14 900 ± 1 048 vs. 60 400 ± 7 733 yuan, p < .001). In contrast, patients receiving operative treatment showed higher complete SMA remodelling (95.9% vs. 51.8%, p < .001). The cumulative rate of symptom relief was similar between the groups (p = .71). The rates were 78% vs. 79%, 87% vs. 87%, 89% vs. 87% at one, 12, and 60 months in the conservative and operative groups, respectively. Further subgroup analysis showed that endovascular treatment of IMAD had the advantage of shorter hospital stays than open surgery (10.7 ± 4.5 vs. 25.2 ± 9.4 days, p < .010). Univariable analysis showed that Sakamoto type II was associated with failed complete SMA remodelling (odds ratio 0.34; 95% confidence intervals 0.13 - 0.91; p = .031).

CONCLUSION

IMAD patients achieved good long term survival and symptom relief regardless of the treatment. Sakamoto type II IMAD is a risk factor for failed complete SMA remodelling. Although endovascular treatment provided a higher rate of complete SMA remodelling, the conservative group had statistically significantly shorter hospital stays, lower hospital costs, and similar cumulative rates of symptom relief. Therefore, this study supports conservative treatment as the main strategy for uncomplicated symptomatic IMAD patients.

Correlation of Riolan's arch diameter to treatment choice in patients with isolated superior mesenteric artery dissection

OBJECTIVE

To investigate the diameter changes of Riolan's arch in patients with isolated superior mesenteric artery dissection (ISMAD) and to evaluate the implication for treatment selection.

METHODS

Ninety-five patients with CT angiography (CTA) confirmed ISMAD were retrospectively included, and another 95 cases with no positive findings on abdominal CTA were included as controls. According to the treatment methods, the patients were subsequently divided into conservative treatment (n = 68) or invasive treatment (n = 27) subgroups. According to the initial CTA images, the prevalence of Riolan's arch as well as its diameter (D_R) were determined in each subject, and compared between ISMAD and control cases, as well as between patients with different treatments. In patients with ISMAD, dissections were classified according to the Li classification.

RESULTS

Riolan's arch prevalence and D_R were significantly elevated in the ISMAD group compared with the control group (83.16% vs. 35.79%, P < 0.001; 2.63 ± 0.56 mm vs. 2.12 ± 0.39 mm, P < 0.001). Patients with invasive treatment had significantly higher baseline D_R (2.93 ± 0.57 mm vs. 1.89 ± 1.14 mm, P < 0.001), and higher proportion of high-risk dissection (P < 0.001) than those administered conservative treatment. Binary logistic regression revealed D_R (OR = 2.771, 95% CI 1.157-6.638, P = 0.022) and Li classification (OR = 0.107, 95% CI 0.019-0.586, P = 0.010) were independent risk factors for treatment selection. With cutoff of 2.635 mm, the area under the curve, sensitivity, and specificity were 0.805, 0.778 and 0.794, respectively.

CONCLUSION

Dilation of Riolan's arch is common in patients with ISMAD, and Riolan's arch diameter could be a convenient indicator of disease severity and inform subsequent treatment.

Endovascular therapy versus medical treatment for spontaneous isolated dissection of the superior mesenteric artery

BACKGROUND

Spontaneous isolated dissection of the superior mesenteric artery (SIDSMA) occurs when a tear in the inner layer of the superior mesenteric artery (SMA) allows blood to flow between the layers of the SMA, forcing the layers apart, and creating two lumens. Abdominal pain is the most prevalent clinical manifestation. Other people may have no symptoms or experience nausea, vomiting, diarrhea, or blood in their stools. For people with SIDSMA who are not suspected of intestinal necrosis or intra-abdominal bleeding, medical treatment and endovascular therapy are the main treatment options. There is no consensus on the optimum first-line management strategy.

OBJECTIVES

To evaluate the benefits and harms of endovascular therapy versus medical treatment for spontaneous isolated dissection of the superior mesenteric artery (SIDSMA).

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was 3 August 2021.

SELECTION CRITERIA

We planned to include all randomized controlled trials (RCTs) which compared endovascular therapy and medical treatments for SIDSMA. We planned to exclude studies where participants were treated with open surgery.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were endovascular intervention rate and recurrent abdominal pain. Our secondary outcomes were open surgery rate, remodeling rate of SMA, new aneurysm formation of SMA, SMA occlusion, new dissection of SMA, death, symptom relief rate and complications of endovascular therapy. We planned to use GRADE to assess certainty of evidence for each outcome.

MAIN RESULTS

We did not identify any RCTs to include in any analysis.

AUTHORS' CONCLUSIONS

We were not able to include any RCTs that compared endovascular therapy versus medical treatment in people with SIDSMA. High-quality RCTs that evaluate the benefits and harms of these interventions are needed to help determine the optimal strategy for managing SIDSMA.

Comparison of Superior Mesenteric Artery Remodeling and Clinical Outcomes between Conservative or Endovascular Treatment in Spontaneous Isolated Superior Mesenteric Artery Dissection

The aim of this study was to analyze the superior mesenteric artery (SMA) remodeling after initial conservative or endovascular treatment with a standardized definition and midterm outcomes in patients with spontaneous isolated dissection of the superior mesenteric artery (SIDSMA). This retrospective study enrolled patients with SIDSMA from January 2007 to August 2019. All patients were treated initially with conservative treatment. If they failed the medical treatment, they were converted to interventional treatment. The morphological endpoint was determined by the standardized SMA remodeling, and the clinical endpoints were determined by the in-hospital mortality, hospital stay, and the bowel-related mid-term mortality. A total of 34 consecutive patients with SIDSMA were identified. Twenty-three (67.6%) and eleven (33.4%) patients underwent conservative and interventional treatments, respectively. Clinical features and morphologic changes on CTA were available in 25 (73.5%) patients during the median follow-up of 23.3 months. Standardized SMA remodeling was significantly (p < 0.05) better in patients undergoing endovascular stenting, especially in patients with Yun's IIb classification. There was no mesenteric ischemia or SMA aneurysm during follow-up period. Patients with SIDSMA can be treated safely with initial conservative treatment. However, significant portions of patients will require endovascular intervention due to the persistent symptoms. Clinically endovascular stenting could be performed successfully, and SMA remodeling was satisfactory during the mid-term follow-up.

Isolated Superior Mesenteric Artery Dissection: A Novel Etiology and a Review

Isolated superior mesenteric artery dissection (ISMAD) is a rare pathology with multifactorial etiology. The aim of this article is to provide a narrative review of the latest literature about ISMAD. Case reports, series, and recent meta-analyses were included. This review is introduced with a brief case report of a rare etiology of ISMAD, followed by a discussion of its etiology, clinical presentation, diagnosis, classification, and treatment, and we report a new cause of ISMAD, that is, blunt abdominal trauma. The etiology of ISMAD is multifactorial, consisting of anatomic, genetic, and systemic components. ISMAD is more common among middle-aged males and in East Asia. Its clinical presentation ranges from asymptomatic to mesenteric ischemia, albeit mortality remains <1%. It is diagnosed and classified mostly by computed tomography angiography, and there are five classification systems for ISMAD, though traumatic etiology may be added. The treatment of ISMAD is mostly conservative, with a success rate exceeding 90%. Endovascular stenting is second line, reserved so far for failed medical management, though its role is expanding to include earlier management of symptomatic patients, while open surgical repair is left for acute mesenteric ischemia with bowel compromise.

Antithrombotic therapy has no beneficial effect in conservative treatment of spontaneous isolated superior mesenteric arterial dissection

Purpose

Initial conservative treatment with selective endovascular or surgical intervention has shown successful outcomes in the treatment of spontaneous isolated superior mesenteric artery dissection (SISMAD). However, the benefits of antithrombotic therapy as a part of conservative treatment have not been clarified. This study aimed to investigate the clinical course of SISMAD patients and determine differences in clinical outcomes between the antithrombotic and no-antithrombotic groups.

Methods

We retrospectively reviewed 79 cases of SISMAD that were treated conservatively from January 2004 to December 2019 at Chonnam National University Hospital. Clinical outcomes, including the length of hospital stay, pain resolution time, image remodeling, and maximal remodeling time, were compared between the antithrombotic and no-antithrombotic groups.

Results

There were 30 patients in the no-antithrombotic group and 49 patients in the antithrombotic group. There was no significant difference in clinical characteristics between the 2 groups, except for dyslipidemia (P = 0.011). The follow-up period (32.6 months vs. 14.6 months, P = 0.009) and imaging follow-up period (31.6 months vs. 13.9 months, P = 0.011) were longer in the antithrombotic group than in the no-antithrombotic group. The length of hospital stay (5.1 days vs. 7.7 days, P = 0.002) was significantly shorter in the no-antithrombotic group than in the antithrombotic group because patients in the antithrombotic group required longer hospitalization for warfarin titration.

Conclusion

In patients with SISMAD, conservative treatment without antithrombotic therapy may have clinical benefits such as decreased length of hospital stay compared with conservative treatment with antithrombotic therapy.

Safety and efficacy of conservative, endovascular bare stent and endovascular coil assisting bare stent treatments for patients diagnosed with spontaneous isolated superior mesenteric artery dissection

Introduction

Isolated dissection of visceral artery organs is very infrequently reported and when it occurs it mostly affects the superior mesenteric artery (SMA) with abdominal pain as the commonest presenting symptom. However, the best therapeutic strategy in symptomatic patients has not yet been established.

Aim

To evaluate the safety and efficacy of conservative, endovascular bare stent and endovascular coil assisting bare stent treatments for patients diagnosed with spontaneous isolated superior mesenteric artery dissection (SISMAD).

Material and methods

We reviewed patients who had SISMAD and received conservative, bare stent and coil assisting bare stent as a primary treatment between 2014 and 2018. Patient demographics, symptoms, angiographic findings and treatment outcomes were analyzed.

Results

A total of 62 patients was found to have SISMAD among whom 83.9% (n = 52) were male and 16% (n = 10) were female with the mean age of 52.55 ±7.22 years, range 33–77. 22.6% (n = 14) received conservative, 62.9% (n = 39) endovascular bare stent and 14. Four percent (n = 9) endovascular coil assisting bare stent treatment. The success rate in primary treatment was conservative 78.5% (n = 11), bare stent 97.4% (n = 38), coil assisting bare stent 100% (n = 9). The mean follow-up duration (months) was 28.76 ±12.87.

Conclusions

Endovascular bare stent placement is a safe, effective, and successful treatment in the management of symptomatic SISMAD. The diagnostic imaging result is a key point for planning appropriate treatment especially in patients with tapered vessels, longer dissection lesion, and dissection aneurysm where coil assisting bare stent shows good results. Conservative treatment should be given priority for the asymptomatic patient, but close monitoring is highly recommended.

Primary Conservative Therapy for Symptomatic Isolated Mesenteric Artery Dissection with Severely Compressed True Lumen or Large Dissecting Aneurysm

PURPOSE

To investigate the safety and effectiveness of primary conservative therapy for patients with symptomatic isolated mesenteric artery dissection (IMAD) with a severely compressed true lumen and/or a large dissecting aneurysm.

MATERIALS AND METHODS

A total of 35 consecutive patients (all men; median age, 53 y) with symptomatic IMAD with a severely compressed true lumen and/or a large dissecting aneurysm but without intestinal necrosis or arterial rupture who were treated with primary conservative therapy between November 2018 and February 2020 were assessed. A severely compressed true lumen was defined as luminal stenosis > 70%. A large dissecting aneurysm was defined as dissecting aneurysm diameter ≥ 1.5 times larger than the normal mesenteric artery diameter.

RESULTS

There was a strong positive relationship among abdominal pain, degree of luminal stenosis, and length of dissection (R = 0.811; P < .001). Conservative treatment was successful in all patients. Abdominal pain was eliminated within 4.7 d ± 4.8 (range, 2-31 d) in all patients, within 3.6 d ± 1.2 (range, 2-6) in the 31 patients with minor or moderate abdominal pain, and within 13.3 d ± 11.9 (range, 6-31 d) in the 4 patients with severe abdominal pain. Complete or partial remodeling of the mesenteric artery was achieved in 6 (17.1%) and 29 (82.9%) patients, respectively, during 8.6 mo ± 4.3 of follow-up.

CONCLUSIONS

Primary conservative therapy can be used safely and effectively in patients with symptomatic IMAD with a severely compressed true lumen and/or a large dissecting aneurysm but without intestinal necrosis or arterial rupture.

Management of Symptomatic Spontaneous Isolated Superior Mesenteric Artery Dissection: A Single Centre Experience with Mid Term Follow Up

OBJECTIVE

This study aimed to report a single centre management experience and mid term outcomes for symptomatic spontaneous isolated superior mesenteric artery dissection (SISMAD).

METHODS

This was a retrospective observational study. Between 1 August 2012, and 30 June 2018, consecutive patients with symptomatic SISMAD were included. Patient demographics, clinical symptoms, comorbidities, risk factors, and dissection characteristics were obtained. The treatment regimens and clinical and follow up outcomes were reviewed and analysed. A chi square test, Fisher's exact test, or one way analysis of variance was used to compare variables between the groups. Binary logistic regression was used to determine predictive factors for failed conservative treatment. The cumulative rate of complete dissection remodelling was calculated using a Kaplan-Meier curve.

RESULTS

Sixty-two patients (mean age, 56.0 ± 9.3 years) were included. Patients at risk of intestinal ischaemia or dissecting aneurysm rupture were considered to be high risk patients (Group 1, n = 16) and received primary endovascular treatment. The remaining patients were considered low risk (Group 2, n = 46) and received primary conservative treatment. Symptom relief was observed in 82.6% of patients in Group 2. Finally, failed conservative treatment was observed in 50% of the low risk patients. Dissection length ≥50 mm was an independent risk factor for failed conservative treatment (p = .019; OR 4.68, 95% CI 1.29-16.98). During a median follow up of 30.5 months (interquartile range, 17.5, 58.3), patients with stents had a higher complete dissection remodelling rate than those without stents.

CONCLUSION

This study found that conservative treatment showed satisfactory symptom resolution for low risk SISMAD patients. Endovascular stenting was associated with a high technical success and dissection remodelling rate. This treatment modality might be reserved for patients with high risk SISMAD or failed conservative treatment. In addition, a dissection length ≥50 mm was a risk factor for failed conservative treatment.

Isolated superior mesenteric artery dissection: CTA features and clinical relevance

PURPOSE

To determine the detailed computed tomography angiography (CTA) features of isolated superior mesenteric artery dissection (ISMAD), aiming to improve the current understanding of ISMAD.

MATERIALS AND METHODS

We retrospectively analyzed 57 patients with confirmed diagnoses of ISMAD with CTA from June 2011 to June 2018 in our hospital. The superior mesenteric artery (SMA) angle, entry site of dissection, and features of both false and true lumen were analyzed individually.

RESULTS

In general, middle-aged men with atherosclerosis (42.1%), hypertension (35.3%), or long-term smoking (33.3%) were the main populations. 80.7% of patients can be discharged successfully after conservative treatment. 87% of patients had a right (or almost right) SMA angle, and the entry site of dissection in 90% of patients occurred in the curved segment of the SMA. As a polymorphic disease, we can use the coded CTA features to delineate individual cases, including cases beyond the presenting classification systems. The diameter of the true lumen is the only different CTA feature between the conservative treatment group and the interventional treatment group (p = 0.000). The re-entry site (p = 0.501), thrombosis in the false lumen (p = 0.135), the distance between the entry site of dissection and SMA root (p = 0.133), and SMA branch involvement (p = 0.322) had no difference between the 2 groups.

CONCLUSIONS

Based on CTA analysis, the bending area, especially in the SMA with right or nearly right SMA angle, is the most vulnerable anatomical region for the occurrence of ISMAD. The diameter of true lumen is the determined CTA feature for the decision of treatment. CTA should be recommended as a standardized diagnostic and classification tool for ISMAD.

Endovascular Management of Isolated Superior Mesenteric Artery Dissecting Aneurysm by Retrograde Catheterization Via Collaterals from the Celiac Artery

Isolated superior mesenteric artery (SMA) dissecting aneurysm is frequently symptomatic and potentially catastrophic; thus, it usually requires endovascular treatment. The endovascular management can be challenging in certain cases as catheterization of the collapsed true lumen is often very difficult. This case report is to describe a new approach for catheterization of the true lumen of the SMA in a case of isolated SMA dissecting aneurysm. A 63-year-old male with an SMA dissecting aneurysm underwent stent-graft placement for treatment. Catheterization of the true lumen via the anterograde approach was unsuccessful because of angulation and collapse of the SMA true lumen as a result of the dissecting aneurysm. A guidewire was passed through the collaterals from the celiac artery and retrogradely passed across the collapsed SMA true lumen into the aorta. We then used a snare that had been delivered through the contralateral femoral access to capture and retrieve the guidewire. A delivery system was advanced into the SMA, and a stent graft was successfully deployed to occlude the dissecting aneurysm. This report introduces a new feasible retrograde approach that provides access to the SMA true lumen via celiac collaterals in cases of difficult antegrade catheterization of an SMA dissecting aneurysm.

Protein-losing enteropathy as a complication of spontaneous isolated superior mesenteric artery dissection: A case report

INTRODUCTION

Protein-losing enteropathy and spontaneous isolated superior mesenteric artery dissection are both rare clinically. Protein-losing enteropathy due to superior mesenteric artery dissection is extremely rare.

PATIENT CONCERNS

A 46-year-old male with acute abdominal pain and hematochezia was diagnosed with a complete occlusion of the superior mesenteric artery because of dissection. He suffered from diarrhea and hypoproteinemia after an emergency thromboendarterectomy.

DIAGNOSES

Based on laboratory tests and capsule endoscopy inspection, a diagnosis of protein-losing enteropathy was made.

INTERVENTIONS

Endovascular treatment was provided.

OUTCOMES

After stent placement, he quickly recovered without a recurrence of symptoms.

CONCLUSION

Protein-losing enteropathy is a serious complication of an isolated superior mesenteric artery dissection. Restoring the patency of the superior mesenteric artery is keyed for the treatment of this complication.

Long-term outcomes of conservative treatment and endovascular treatment in patients with symptomatic spontaneous isolated superior mesenteric artery dissection: a single-center experience

BACKGROUND

Spontaneous isolated superior mesenteric artery dissection (SISMAD) is a rare vascular disorder, and the treatment strategies remain controversial. This study aimed to compare outcomes of conservative and endovascular treatments in symptomatic patients with SISMAD.

METHODS

Forty-two consecutive SISMAD patients who were admitted to a single center between October 2009 and May 2018 were enrolled in this study. Based on their symptoms, 15 had conservative treatment, and 27 had endovascular treatment. The baseline characteristics, treatments, and follow-up results of the conservative group and endovascular group were analysed.

RESULTS

The rates of symptom relief were 93.3% in the conservative group and 96.3% in the endovascular group. The procedure-related complications in the endovascular group included one case of pseudoaneurysm formation in the left brachial artery. During the follow-up period (median 28.5 months), a higher proportion of patients in the conservative group had symptom recurrence (42.9% in the conservative group versus 4.8% in the endovascular group, p < 0.001). Four patients in the conservative group and one patient in the endovascular group had additional endovascular intervention during follow-up. Compared with the conservative group, patients in the endovascular group had statistically significantly longer symptom-free survival (p = 0.014) and a higher rate of superior mesenteric artery (SMA) remodeling (p < 0.001).

CONCLUSIONS

For symptomatic SISMAD, endovascularly treated patients had a lower rate of symptom recurrence and a higher rate of SMA remodeling in the long term. Prospective, multi-center studies are needed to confirm the long-term outcomes of both treatments.

Primary conservative treatment for peritonitis-absent symptomatic isolated dissection of the superior mesenteric artery with severely compressed true lumen

Objectives

The purpose of this study was to evaluate the safety and efficacy of primary conservative treatment (PCT) for peritonitis-absent symptomatic spontaneous isolated dissection of the superior mesenteric artery (S-SIDSMA) with severely compressed true lumen.

Methods

From January 2013 to December 2018, PCT was used in 26 cases of peritonitis-absent S-SIDSMA with severely compressed true lumen in our center based on our previous proposed treatment algorithm for S-SIDSMA. The demographics, duration from the onset to the admission, duration from the start of the conservative treatment to the alleviation of the symptoms, and in-hospital and follow-up clinical and angiographic outcomes were prospectively recorded and then analyzed.

Results

Among the 26 included patients, 84.6% were male. The mean age of the patients was 54.7 years. The mean duration from the onset to the admission was 3.1 days (range, 1–14 days). Symptoms in 22 patients were markedly or completely relieved during the first five-day medical treatment. Endovascular stent placement was attempted in the remaining four patients, which was successfully performed in three (75%) of them. The technical failure occurred in a patient whose compressed true lumen failed to be cannulated. Medical treatment was then continued in this patient, and his symptoms were relieved after a two-day medical treatment. During the mean follow-up period of 14.3 months, endovascular stent placement was performed in three patients due to the recurrence of the abdominal pain and the chronic intestinal ischemia. No patient showed dissection progression during the follow-up. The complete remodeling rate of the stent group was significantly higher than that of the medical group (83.3% vs. 25%, P = 0.021).

Conclusions

Based on our previous proposed treatment algorithm for S-SIDSMA, PCT could achieve satisfactory results both clinically and morphologically in peritonitis-absent S-SIDSMA with severely compressed true lumen.

Management Strategy Based on Disease Stages for Patients with Symptomatic Isolated Mesenteric Artery Dissection

BACKGROUND

An optimal treatment regimen is sought for symptomatic isolated mesenteric artery dissection (IMAD) on the basis of its clinical staging.

METHODS

From January 2011 to December 2018, 120 patients with symptomatic IMAD from two institutions were collected retrospectively. We reviewed the clinical features, risk factors, computed tomography (CT) images, treatment modalities, and follow-up results to propose a new management strategy based on the clinical stages of the disease.

RESULTS

A total of 120 patients were collected in this study; 77 patients (69 men, 8 women; median age, 52.53 years; range, 39-73 years) who had undergone successful conservative management with antithrombotic agents were included in group A. The remaining 43 patients (34 men, 9 women; median age, 52.63 years; range, 26-66 years) who underwent invasive therapy were included in group B. Significant differences were observed between the two groups with respect to dissection length (50.72 ± 27.72 mm vs. 62 ± 24.3 mm; P = 0.02), true lumen residual diameter (3.31 ± 1.05 mm vs. 2.83 ± 2.05 mm; P = 0.01), and branch involvement (8 and 19, respectively; P < 0.001). Success was achieved in 76.24% (77/101) of patients treated by conservative management with antithrombotic agents in the acute stage; 43 patients underwent invasive interventional therapy in different stages of symptomatic IMAD. In group A, 6 patients had recurrent abdominal pain, three of whom underwent invasive intervention, and the remaining patients improved after conservative treatment. Positive remodeling was observed in 80.33% (49/61) of patients treated with conservative management alone versus 19.67% (12/61) of patients who experienced negative remodeling. Endovascular intervention in group B, CT angiography, or mesenteric angiography yielded complete remodeling in 23 (76.67%, 23/30) patients and evidence of stent restenosis in 7 (23.33%, 7/30) patients. Among the surgical patients, 7 patients showed improvement in the luminal diameter. However, 3 patients with short bowel syndrome require long-term parenteral nutrition.

CONCLUSIONS

Conservative management with antithrombotic agents should be a first-line regimen for symptomatic IMAD in the acute stage. If symptoms persist, endovascular intervention is a safe and feasible treatment in the subacute or chronic stage. When peritonitis is present, surgical treatment should be promptly performed, regardless of the disease stage.

Optimal Treatment Strategy and Natural History of Isolated Superior Mesenteric Artery Dissection Based on Long-Term Follow-up CT Findings

BACKGROUND

Isolated superior mesenteric artery dissection (ISMAD) was previously considered a rare disorder; however, this condition has been increasingly diagnosed as time progressed. Although treatment regimen and treatment outcomes have become clearer, the optimal treatment strategy has not yet been well established.

MATERIALS AND METHODS

This study included 54 patients diagnosed with ISMAD by computed tomography (CT) between November 2004 and December 2017. Thirteen patients were excluded from the analysis of natural course as 6 were lost to follow-up, and 7 underwent endovascular therapy.

RESULTS

Of the 54 patients included in the study, 50 were male, and 4 were female. The mean age of the patients was 52.3 years (range 40-74). The mean follow-up duration was 18.5 months (range 1.0-131.0). Thirty-eight patients were symptomatic, and 16 were asymptomatic. All aneurysmal changes observed on follow-up CT scans were initially classified as type III or IV. Of these patients, 7 underwent endovascular therapy. The failure rate of conservative treatment was 13%.

CONCLUSIONS

Conservative treatment is safe and effective if bowel necrosis or arterial rupture is not present. Symptomatic patients classified as type III or IV on the initial CT scan should be followed up. If there is recurrent pain or aneurysmal progression, endovascular therapy should be performed.

Combination of Colour Duplex and Contrast Enhanced Ultrasound as an Alternative to Computed Tomography Angiography in Isolated Mesenteric Artery Dissection Surveillance

OBJECTIVES

The aim was to investigate the effectiveness of colour duplex ultrasound (CDU) plus contrast enhanced ultrasound (CEUS) vs. computed tomography angiography (CTA) for surveillance in patients with isolated mesenteric artery dissection (IMAD).

METHODS

Patients who underwent CDU, CEUS, and CTA for surveillance of IMAD between January 2012 and May 2019 were included in the study. The accuracy of CDU, CEUS, and CTA for determining the morphological characteristics of IMAD was analysed.

RESULTS

A total of 42 patients undergoing 76 total imaging examinations during follow up were included. Both CTA and CDU plus CEUS demonstrated the thrombosed false lumen for 28 (36.8%) examinations and the dissecting aneurysm for 20 (26.3%) examinations (both κ = 1.0). The diameter of the dissecting aneurysm was 5.03 ± 1.25 mm using CDU and CEUS vs. 5.27 ± 1.23 mm on CTA (coefficient of consistency, 0.997; p < .001). The entry points were visualised by CDU and CEUS for 20 (26.3%) examinations and by CTA for 14 (18.4%) examinations (κ = 0.769); no re-entry points were visualised by CDU and CEUS for any examinations but re-entry points were visualised by CTA for two (2.6%) examinations. The minimum inner diameter was 2.80 ± 1.30 mm on CDU and CEUS vs. 2.52 ± 1.29 mm on CTA (coefficient of consistency, 0.999; p < .001). The peak systolic velocities were 128.2 ± 13.0 cm/s at diagnosis and 98.7 ± 4.9 cm/s after one month (p < .001).

CONCLUSIONS

The combination of CDU and CEUS can be used in place of CTA for the surveillance of IMAD.

Mesenteric Artery Remodeling after Conservative Management in Patients with Isolated Mesenteric Artery Dissection

PURPOSE

To retrospectively investigate factors associated with mesenteric artery remodeling after conservative management of isolated mesenteric artery dissection (IMAD) (dissection of the mesenteric arteries in the absence of aortic dissection or other known causes).

MATERIALS AND METHODS

A total of 107 patients diagnosed with IMAD between February 2010 and October 2018 were identified. Eighteen patients were excluded because they underwent stent placement (n = 11) or were lost to follow-up (n = 7). A total of 89 patients who underwent conservative management were therefore included in the study. Cox regression analysis was performed to identify factors associated with mesenteric artery remodeling.

RESULTS

During 15.9 ± 10.9 months of follow-up, complete remodeling of the mesenteric artery was achieved in 66 patients (74.2%), and partial remodeling was achieved in 23 patients (25.8%). Of the 66 patients with complete remodeling, 6 (9.1%) had type IIa IMAD (visible false lumen, no visible re-entry site), and 60 (90.9%) had type IIb IMAD (thrombosed false lumen). The mean interval between IMAD diagnosis and complete remodeling was 14.4 ± 5.4 months for all patients. The mean intervals for patients with type IIa IMAD were 20.0 ± 6.2 months and 13.9 ± 5.1 months for patients with type IIb IMAD (P = .015). Mesenteric artery remodeling was significantly associated with the presence of symptoms (odds ratio, 10.800; 95% confidence interval, 1.961-59.470; P = .006).

CONCLUSIONS

Complete remodeling of the mesenteric artery in patients with IMAD treated with conservative management is common, and the presence of symptoms is associated with complete remodeling.

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.

Factors Associated with Failed Conservative Management in Symptomatic Isolated Mesenteric Artery Dissection

OBJECTIVE

The aim of this study was to assess factors associated with conservative management failure in patients with symptomatic isolated mesenteric artery dissection.

METHODS

Patients with symptomatic isolated mesenteric artery dissection who underwent conservative therapy as first line treatment between February 2010 and May 2018 were included in this retrospective study. Conservative management failure was defined as the persistence or aggravation of symptoms and signs, increasing aneurysmal dilation, or new appearance of a dissecting aneurysm after conservative management. Univariable and multivariable analyses were performed to identify risk factors for failure of conservative management.

RESULTS

A total of 123 patients (115 men, 8 women, mean age, 53.7 ± 6.1 years) were included in this study. Conservative management was successful in 89 (72.4%) patients but failed in the remaining 34 (27.6%) patients. Of the 89 for whom conservative management was successful, all of the symptoms were eliminated (n = 81) or relieved (n = 8) within 3.8 ± 0.7 days after conservative management. All of the 34 patients in whom conservative management failed underwent successful endovascular stenting. Failure of conservative management was associated with type II IMADs as defined by the Sakamoto classification (meaning that there is an entry tear, but no re-entry, and still no thrombosis of false lumen, odds ratio: 33.76; 95% confidence interval 8.65-131.85; p < .001) and with ≥90% luminal stenosis (odds ratio 40.70; 95% confidence interval: 3.76-440.07; p < .01).

CONCLUSIONS

Conservative management can be used successfully in most patients with symptomatic isolated mesenteric artery dissection. Risk factors for failed conservative treatment were type II IMADs and degree of luminal stenosis ≥90%.

A Rare Case of Spontaneous Isolated Dissection of the Superior Mesenteric Artery

Isolated spontaneous dissection of the superior mesenteric artery (SMA) is a rare entity that is increasingly becoming recognized due to an improvement in imaging techniques. The pathogenesis of a spontaneous SMA dissection has yet to be fully elucidated. Here, we present the case of isolated SMA dissection in a 65-year-old female who was seen in the emergency room with acute substernal chest and left upper quadrant abdominal pain. She was managed for atrial fibrillation with a rapid ventricular response. She underwent computed tomography (CT) angiogram of the chest, abdomen, and pelvis, which revealed focal dissection involving SMA measuring 2.7 cm in width. Vascular surgery recommended conservative management with low-dose daily aspirin and the optimization of blood pressure control. She subsequently was seen as an outpatient with complete resolution of abdominal pain. Given the low incidence rate, vascular surgery evaluation may be required to determine the best course of management. Treatment needs to be individualized for each patient. Since abdominal pain is a common complaint for which patients are seen in each clinical setting, it is important to highlight this case to create awareness regarding the possibility of isolated SMA dissection as one of the underlying etiologies.

Diagnostic value of color Doppler sonography for spontaneous isolated superior mesenteric artery dissection

The present study aimed to evaluate the clinical significance of color Doppler sonography (CDS) in the diagnosis of spontaneous isolated superior mesenteric artery dissection (SISMAD). The ultrasonographic images of 19 patients with SISMAD confirmed by computed tomography angiography (CTA) were retrospectively analyzed and the ultrasonographic features were summarized. The paired t-test was used to statistically analyze the differences in parameters determined by CTA vs. CDS, including the minimal inner diameter (MID), cross-sectional area (CSA), diameter and area stenosis rate, and flow rate of the true lumen. Of the 19 patients, 18 (94.7%) were diagnosed with SISMAD with correct classification by CDS. There was no significant difference between CTA and CDS with regard to minimal ID, CSA, diameter stenosis and area stenosis rate, and flow rate of the true lumen (all P>0.05). CDS was indicated to be an effective imaging modality for the diagnosis of SISMAD.

Clinical and CT Angiographic Follow-Up Outcome of Spontaneous Isolated Intramural Hematoma of the Superior Mesenteric Artery

OBJECTIVES

The aim of this study was to evaluate the clinical course and vascular remodeling of spontaneous isolated intramural hematoma of the superior mesenteric artery (SIHSMA) after treatment.

METHODS

In this retrospective study, 24 consecutive patients with SIHSMA admitted from January 2009 through December 2016 were included in this study. The clinical characteristics, type and location of the dissection, clinical outcome and vascular remodeling were analyzed retrospectively.

RESULTS

The subjects included 21 men and three women, with a mean age of 50.58 years. The chief complaint was abdominal pain in all patients. The mean follow-up was 10.08 months. Among the 24 patients examined, two patients (8.33%) showed no obvious changes in the CT. Twenty patients were treated by conservative strategy. One case underwent exploratory laparotomy along with embolectomy and arteriotomy. Another three cases received angioplasty and stent implanting. Complete and partial remodeling was observed in 15 (62.5%) and four patients (16.67%). Three (12.5%) of the lesions had dissection remodeling and aneurysm change.

CONCLUSIONS

SIHSMA represented variable vascular remodeling, while most of the patient got a complete resolution during follow-up, and its clinical course was benign in this study. Vast majority of patients can be managed conservatively when there are no signs indicating organ ischemia.

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.

Endovascular Treatment of Patients with Isolated Mesenteric Artery Dissection Aneurysm: Bare Stents Alone Versus Stent Assisted Coiling

OBJECTIVE

The aim was to evaluate the outcomes of endovascular treatment with bare stents alone versus stent assisted coiling in isolated mesenteric artery dissection (IMAD) aneurysms.

METHODS

Patients with an IMAD aneurysm who underwent endovascular stenting between February 2010 and February 2017 at one of three institutions were included in this study. Data regarding technical success, procedure time, symptom resolution, complications, changes in IMAD aneurysm, and stent patency were recorded.

RESULTS

A total of 38 patients (35 men) were included, 27 treated with bare stents alone and 11 treated with stent assisted coiling. Technical success was achieved in 100% of patients treated with bare stents and in 81.8% of those treated with stent assisted coiling (p = 0.078). The mean procedure times were 62.6 ± 5.3 min for treatment with bare stents and 116.4 ± 8.4 min for stent assisted coiling (p < 0.001). A total of 23 patients had persistent symptoms before stenting; all symptoms were resolved within 3.0 ± 0.7 days. No procedure related major complications occurred. Over 30.2 ± 18.1 months of follow up, complete resolution of the IMAD aneurysm was achieved in all patients; good stent patency and in stent re-stenosis were achieved in 65.8% and 34.2% patients, respectively. There were no occlusions of the stented arteries.

CONCLUSIONS

Bare stents alone and stent assisted coiling have high technical success rates and demonstrate good intermediate patency in patients with an IMAD aneurysm. Bare stents alone may serve as an alternative to stent assisted coiling for the management of IMAD aneurysm.

Systematic review and meta-analysis of current evidence in spontaneous isolated celiac and superior mesenteric artery dissection

OBJECTIVE

Spontaneous isolated celiac artery dissection (SICAD) and spontaneous isolated superior mesenteric artery dissection (SISMAD) represent the major types of spontaneous visceral artery dissection. However, no quantitative meta-analysis of SICAD and SISMAD is available. The aim of our study was to pool current evidence concerning basic profiles, treatment strategies, long-term adverse events, and morphologic changes of lesioned vessels in SICAD and SISMAD patients.

METHODS

We searched the MEDLINE, Embase, Scopus, and Cochrane Databases (January 1, 1946-September 21, 2017) for studies of SICAD and SISMAD. Related cohort studies or case series with sample size larger than 10 were included. Two reviewers independently extracted and summarized the data. A random-effects model was used to calculate pooled estimates.

RESULTS

In total, 43 studies were included. An estimated 8% (95% confidence interval [CI], 0.01-0.21) symptomatic SICAD and 12% (95% CI, 0.06-0.19) symptomatic SISMAD patients with initial conservative management required secondary intervention during follow-up, whereas none of the asymptomatic patients treated conservatively required secondary intervention. As for morphologic changes during follow-up, a higher proportion of SICAD patients (64%; 95% CI, 0.47-0.80) achieved complete remodeling compared with SISMAD patients (25%; 95% CI, 0.19-0.32), and an estimated 6% (95% CI, 0.00-0.16) of SICAD and 12% (95% CI, 0.05-0.20) of SISMAD patients had morphologic progression. Overall, the pooled estimate of long-term all-cause mortality was 0% (95% CI, 0.00-0.03) in SICAD and 1% (95% CI, 0.00-0.02) in SISMAD. When stratified by symptoms, symptomatic patients were associated with a significantly increased probability of accomplishing complete remodeling (odds ratio, 3.95; 95% CI, 1.31-11.85) compared with asymptomatic patients.

CONCLUSIONS

Initial conservative treatment is safe for asymptomatic SICAD or SISMAD patients. Symptomatic patients managed conservatively have relatively high occurrence of late secondary intervention, which may require closer surveillance, especially in SISMAD because of a lower rate of remodeling.

Treatment Strategies and Outcomes of Symptomatic Spontaneous Isolated Superior Mesenteric Artery Dissection: A Systematic Review and Meta-analysis

Purpose: To analyze the published treatment experience with symptomatic spontaneous isolated superior mesenteric artery dissection (SISMAD). Methods: A literature search of the PubMed and Cochrane databases was conducted for articles on symptomatic SISMAD published in English from January 2007 to January 2018. Case series reporting on both treatment modalities and outcomes were included, while those on traumatic or iatrogenic SMA dissection or SMA dissection accompanied by aortic or other visceral artery dissection were excluded. Overall event rates for treated symptomatic SISMAD were calculated using pooled analyses. The rate of initial conservative treatment, the success rate, the rate of conversion to intervention, and the failure rate in patients with vs without antithrombotic therapy were calculated for each study and compared using a meta-analysis of proportions. Results: The 25 articles selected encompassed 616 SISMAD cases, of which 514 were symptomatic cases eligible for the analysis. Among the latter, initial treatment consisted of conservative therapy in 447 (87.0%) patients and surgical interventions in 67 (13.0%) patients [45 (8.7%) endovascular procedures and 22 (4.3%) open surgeries]. Among conservative cases, 238 (53.2%) received antithrombotic therapy while 172 (38.5%) did not; 50 (11.2%) cases were converted to intervention [42 (84%) endovascular]. Conservative treatment was initially used in 85.2% of pooled cases with an 84.7% success rate, a 14.3% rate of conversion to intervention, and conservative treatment failure rates of 17.8% and 10.1% in patients treated with vs without antithrombotic therapy, respectively (p=0.103). Conclusion: Conservative treatment appeared safe and effective in >80% of symptomatic SISMAD cases, without apparent benefit for antithrombotic agent use. Initial or secondary intervention was more often endovascular, with favorable success rates and short-term outcomes. Large, prospective randomized trials with long-term follow-up are warranted on the treatment for symptomatic SISMAD.