Treatment strategy based on the natural course for patients with spontaneous isolated superior mesenteric artery dissection

Validation of classification system for isolated superior mesenteric artery dissections using image-based computational flow analysis

BACKGROUND AND OBJECTIVE

The isolated superior mesenteric artery dissection (ISMAD) is a rare but potentially fatal vascular disorder. Classifications for ISMAD were previously proposed based on morphometric features. However, the classification systems were not standardized and verified yet. This study conducted computational flow analysis to validate the latest classification system of ISMAD and aid clinical decision-making based on hemodynamic parameters.

METHODS

62 patients with ISMAD were included and classified into different types according to false lumen structures (five types, Type I-V) and true lumen patency (two types, Type P and Type S) according to Qiu classification system. Computational fluid dynamics and three-dimensional structural analyses were conducted on the basis of computed tomography angiography datasets. Quantitative and qualitative functional analyses were performed via parameters of interest including volume flow of each minute, pressure drop, pressure gradient, the derivative parameters of wall shear stress such as time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), and the relative residence time (RRT). Statistical analyses were conducted among different ISMAD types.

RESULTS

TAWSS, OSI and RRT showed significant difference among different types when classified using false lumen structures. In detail, Type IV showed significantly higher TAWSS than other types (p = 0.007). OSI was obviously higher in Type II (p = 0.015). Type IV also presented the lowest RRT (p = 0.005). The pressure drop, pressure gradient, OSI and RRT showed higher value in Type S than that in Type P, demonstrating a statistical significance with p values of 0.017, 0.041, 0.001 and 0.012, respectively. While Type P had larger volume flow than Type S (p = 0.041).

CONCLUSIONS

The notable differences in hemodynamic features among different types demonstrated the feasibility of Qiu classification system. The evaluation based on hemodynamic simulation might also provide insights into risk identification and guide therapeutic decisions for ISMAD.

Comparison of clinical outcomes between medical or/and endovascular therapy in spontaneous isolated superior mesenteric artery dissection patients without bowel ischemia

OBJECTIVE

This study aims to assess the clinical results of endovascular intervention for spontaneous isolated superior mesenteric artery dissection (SISMAD) and its impact on superior mesenteric artery (SMA) remodeling in comparison to solely medical management.

METHODS

All patients with SISMAD between January 2015 and August 2023 were included. The primary endpoints were the absence of major adverse events (MAEs), including dissection-related mortality, recurrence of mesenteric ischemia symptoms, and the necessity for intervention. The secondary endpoints were stenosis or occlusion of the SMA and morphologic remodeling of the dissections.

RESULTS

A total of 217 SISMAD patients were included. In this study, 127 (58.5 %) patients received medical management alone (conservative group), and 90 (41.5 %) underwent endovascular therapy (EVT group). In the EVT group, the technical success rate was 94.4 % (85/90). During follow-up, 13 (6.0 %) patients experienced MAEs, and 1 patient in the conservative group death related to SISMAD. The patients in EVT group showed more complete remodeling than those in the conservative group (76 (84.4 %) vs 66 (52.0 %), P < .0001). Survival analysis showed that the estimated MAEs-free survival rates were97.8 %, 95.6 %, and 95.6 % in EVT group and 98.4 %, 94.5 %, 92.9 % in conservative group at one, two, and three years, respectively. No significant difference was observed in both groups.

CONCLUSION

The findings indicate that both endovascular treatment and medical management alone yield comparable rates of MAE-free survival among patients with SISMAD. Additionally, endovascular therapy exhibits a higher rate of complete remodeling and greater freedom from stenosis or occlusion of the SMA.

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

The role of endovascular stent therapy (EST) in the treatment of spontaneous isolated superior mesenteric artery dissection (SISMAD) has gained momentum in recent years but remains controversial. We gathered research examining the advantages and disadvantages of EST for SISMAD patients. Primary outcomes involved both immediate and long-term results. Random or fixed effect models were used for effect size (ES) calculation with 95% confidence interval (CI) based on 50% heterogeneity threshold. Our analysis incorporated data from 21 studies including 611 SISMAD cases treated by EST. Our findings show a complication rate of approximately 1% following EST (95%CI 0.01-0.02, I2 = 0%, P = 0.97), with a bare minimum mortality rate of < 1% (95%CI 0.00-0.01, I2 = 0%, P > 0.05) and a reintervention rate of < 1% (95%CI 0.00-0.01, I2 = 0%, P = 0.89). We also found technique success and symptom resolution approaching 94% and 99%, respectively, in the immediate postoperative phase. In the long run, we observed a recurrence of symptoms at 3% (95%CI 0.00-0.06, I2 = 58.6%, P < 0.01), creation of new dissections at 1% (95%CI 0.00-0.02, I2 = 0%, P = 0.73), aneurysm progression at 2% (95%CI 0.00-0.03, I2 = 42.7%, P = 0.12), reintervention due to complications at 3% (95%CI 0.00-0.05, I2 = 0%, P = 0.43) and stenotic stents at 12% (95%CI 0.04-0.23, I2 = 77.5%, P < 0.01). Nevertheless, high levels of stent patency 98% (95% CI 0.97-1.00, I2 = 0%, P = 0.51) and complete remodeling 88% (95% CI 0.82-0.94, I2 = 65.5%, P < 0.05) were observed postoperatively. Overall, EST presents minimal complications and promising long-term outcomes for SISMAD, although the prevalence of stent stenosis requires further attention.

Open thrombectomy, patch angioplasty, and retrograde stenting for isolated superior mesenteric artery dissection

Isolated superior mesenteric artery dissection without aortic involvement is an exceptionally rare event. Nonoperative management remains the first-line therapy. However, surgical interventions can be indicated in the event of bowel ischemia. In the present report, we describe a case of complicated isolated superior mesenteric artery dissection treated with a hybrid approach.

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.

Factors associated with false lumen changes in patients with superior mesenteric artery dissection

BACKGROUND

False lumen changes (FLCs) are the main reference for the prognosis judgment and treatment plan selection for type IIa superior mesenteric artery dissection (SMAD).

METHODS

For this retrospective study, 55 patients with symptomatic type IIa SMAD were included. Computational fluid dynamics (CFD) analysis was used to explore the hemodynamic basis of FLCs. Correlation and multiple linear regression analyses were performed to identify clinical, morphological and hemodynamic factors associated with FLCs.

RESULTS

The FLCs of patients with successful conservative treatment (n = 29) are significantly higher than those with failed conservative treatment (n = 26) (58.5 ± 21.1% vs 10.9 ± 17.4%, p < 0.0001). Positive correlations were seen between FLCs and the morphological parameters false lumen length (FLL)/dissection entrance length (DEL) and FLL. In terms of hemodynamic parameters, negative correlations were seen between FLCs and time-averaged wall shear stress (TAWSS), vorticity, and high areas of TAWSS and vorticity, whereas positive correlations were seen between FLCs and oscillatory shear index (OSI), relative residence time (RRT), and high areas of OSI and RRT. Multiple linear regression analysis identified symptom duration (odds ratio [OR], 0.93; 95% CI, 0.91-0.96; p < 0.0001), FLL/DEL (OR, 1.30; 95% CI, 1.01-1.67; p = 0.044), and high RRT area (OR, 2.03; 95% CI, 1.48-2.78; p < 0.0001) as predictors of FLCs.

CONCLUSION

The clinical predictor symptom duration, morphological factor FLL/DEL, and the hemodynamic factor high RRT area can serve as predictors of FLCs in patients with symptomatic type IIa SMAD.

Conservative versus stent treatment for spontaneous isolated superior mesenteric artery dissection after the failure of initial 3 days' conservative treatment: A 10-year follow-up study

OBJECTIVES

To compare the safety and effectiveness of conservative and stent treatment for spontaneous isolated superior mesenteric artery dissection (SISMAD) patients after the failure of initial 3 days' conservative treatment.

METHODS

All newly diagnosed SISMAD patients between 2013 and 2017 were retrospectively reviewed. After the failure of 3 days' conservative treatment, all patients were recommended for stent treatment, but some patients refused to choose it. Their demographic, radiologic, and clinical data were compared.

RESULTS

57 patients were not improved after initial 3 days' conservative treatment. Among them, 19 patients were chose to receive stent placement and 38 patients were continually treated with conservative treatment. The median follow-up time was 92.0 (range 62.7-120.4) months. There were no bowel ischemia and arterial rupture. No significant difference was observed in clinical complete recovery (Conservative 31/38 vs Stent 12/19, p =.19) and hospitalization time (Conservative 8.3 ± 1.7 days vs Stent 7.2 ± 1.5 days, p =.59) between conservative and stent treatment groups. Significant statistical differences were found in radiological complete remodeling (6/38 vs 16/19, p < .01) and hospitalization expense (8662 ± 2886 China Yuan vs 32,935 ± 11,767 China Yuan, p < .01) between these two groups.

CONCLUSIONS

Although undergoing the failure of initial 3 days' conservative treatment, continue conservative treatment still is safe and effective for SISMAD patients. Stent placement could be chosen as an alternative treatment, especially for patients potentially with bowel ischemia or arterial rupture.

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.

Placement of Bare Self-Expanding Metal Stent for Isolated Superior Mesenteric Artery Dissection

BACKGROUND

To evaluate the safety and efficacy of placing bare self-expanding metal stent (SEMS) for treating isolated superior mesenteric artery dissection (ISMAD).

METHOD

Patients with ISMAD who received bare SEMS from January 2014 to December 2021 at the authors' center were included. Baseline characteristics, clinical manifestation, radiological findings, and treatment outcomes, including symptom relief and SMA remodeling, were analyzed.

RESULT

A total of 26 patients were included in this study. Among the patients, 25 were admitted due to persistent abdominal pain, and 1 was admitted based on computed tomography angiography (CTA) during physical examination. According to CTA scan, the percentage of stenosis was 91% (53.8-100%), and the length of dissection was 100.2 ± 8.4 mm. All patients received bare SEMS placement. The median time to symptom relief was 1 day (interquartile range, 1 3 days). The the median follow-up time of CTA was 6.8 months (range, 2-85 months), with an average of 16.2 months. Complete remodeling of the superior mesenteric artery (SMA) was recorded in 24 patients. The median time to remodeling was 3 months with an average of 4.7 months. Survival analysis indicated no significance difference in remodeling time between different ISMAD types based on Yun classification (P = 0.888) or between acute and nonacute disease (P = 0.423). Incomplete remodeling was noted in 2 patients. Distal stent occlusion without SMA-related symptoms was seen in 1 patient. Proximal stent stenosis occurred in 1 patient, and restenting was performed. The median follow-up time by telephone was 20.8 (4-91.5) months, and no intestinal ischemic symptoms were observed in any patient.

CONCLUSIONS

Bare SEMS placement can effectively relieve SMA-related symptoms in a short time and promote dissection remodeling in ISMAD. Time from symptom onset and classification of ISMAD seem not to have effects on SMA remodeling after bare SEMS placement.

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.

Spontaneous Celiac Artery Dissection with Splenic Infarction: A Report of Two Cases

Spontaneous isolated celiac artery dissection (SICAD) is a rare condition that is characterized by sudden onset abdominal pain, typically occurring in middle-aged men. Although its clinical course is mostly benign, it may progress to true lumen occlusion. No established therapeutic guidelines are available for SICAD associated with splenic infarction. This report describes two patients who presented with sudden onset abdominal pain and were diagnosed with SICAD with splenic infarction based on computed tomography (CT) findings. Patients were treated with bowel rest and anticoagulants. After a week of medical therapy, the abdominal pain resolved. Follow-up CT revealed no progression of the dissection flap. The patients received oral anticoagulants for 3 months and did not experience any symptom recurrence. Medical therapy with anticoagulants may be considered for patients with SICAD and splenic infarction. Associated splenic infarction itself is not an indication for endovascular or surgical intervention for SICAD.

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.

Case–Control Study of 3D Morphology in Isolated Mesenteric Artery Dissection

INTRODUCTION

Isolated mesenteric artery dissection (IMAD) is uncommon and has not been investigated in detail. This study aimed to accurately identify the morphological differences of IMAD patients with control individuals using a detailed 3D volumetric analysis.

METHODS

In this retrospective case-control study, cases were patients with acute symptomatic IMAD treated in a French intestinal stroke center between January 2016 and November 2019. Case-control matching was (1:3) by age, gender, and body mass index (BMI). The semi-automatic morphological analysis of the mesenteric artery included volumetric measurements of the true and false lumen size, the centerline curvature and the 3D aortomesenteric angles.

RESULTS

Seventeen IMAD cases (mean age 56 ± 4 years, 94% men) were matched with 51 controls. The mean overall lumen (OL) volume was higher in IMAD patients as compared to controls (+ 64%, p < 0.001). In the same way, the mean OL cross-sectional area and diameters were higher in IMAD patients: + 77% for OL area (< 0.001) and + 34% for OL diameters (< 0.001). Meanwhile, no significant difference was found in terms of true lumen (TL) volume (p = 0.16) or cross-sectional area (p = 0.30) between IMAD patients and controls, whereas the mean TL diameter was lower in the IMAD group (p < 0.05). Patients with acute mesenteric ischemia had a lower [TL/OL volume] ratio (45% vs. 59%, p < 0.05) and longer dissections (63 mm vs. 48 mm, p < 0.01). The 3D aortomesenteric angle was significantly higher in IMAD patients at both 2 cm (p < 0.01) and 4 cm (p < 0.05) from the ostium.

CONCLUSION

Using an original 3D semi-automated analysis, this study shows that IMAD induces significant morphological changes compared to control individuals: a larger aortomesenteric 3D angle, an increased overall volume and area. IMAD patients with acute mesenteric ischemia presented with a more severe morphological profile.

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.

Natural Course and Treatment of Symptomatic Spontaneous Isolated Superior Mesenteric Artery Dissection with Total True Lumen Occlusion

OBJECTIVE

We retrospectively investigated the association between the imaging features of spontaneous isolated superior mesenteric artery dissection (SISMAD) accompanied by total true lumen occlusion and the clinical symptoms to identify the patients at high risk and establish personalized therapeutic options.

METHODS

Among 261 patients with SISMAD, we selected 37 with Yun's type III dissection; 35 patients underwent successful conservative management and 2 patients underwent exploratory laparotomy. After discharge, all patients were periodically followed up on an outpatient basis. We recorded patients' general condition, symptoms, time until symptom relief, imaging findings and follow-up results.

RESULTS

All patients experienced acute abdominal pain prior to admission, with an onset time of 29.95 ± 24.66 hours. The mean time until relief of abdominal pain in patients who received conservative treatment was 42.17 ± 38.09 hours. Correlation analysis revealed no correlation between the length of dissection or of the occluded segment and abdominal pain intensity. Pain scores were lower and time until pain relief was shorter in patients with a definite arc of Riolan (AOR) on admission than in those without an AOR. No collateral circulation was observed in the two patients who underwent exploratory laparotomy, and distal intestinal perfusion was poor in these cases. Complete and partial remodeling of the superior mesenteric artery (SMA) was observed in 6 and 16 patients, respectively at the 12-month follow-up. Although the SMA remained occluded in 12 patients, abundant collateral circulation was detected. Three patients were lost to follow-up.

CONCLUSION

This study highlights that conservative treatment should be attempted as first-line therapy in most patients with Yun's type III SISMAD. Complete AOR can contribute to remission of clinical symptoms during the acute stage. Poor distal blood flow of occluded vessels may serve as an important indicator for identification of patients at high risk of ischemic intestinal necrosis.

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.

Relationship Between Morphological Remodeling and Angiographic Types of Spontaneous Isolated Superior Mesenteric Artery Dissection After Conservative Management: Determinant Affecting Serial Radiologic Courses

Objective

To monitor the radiological courses of symptomatic spontaneous isolated superior mesenteric artery dissection (SISMAD) after conservation, clarify the relationship between its morphological change and initial imaging classification, and identify these factors that affect dissection remodeling.

Methods

Eighty-nine conservative patients with SISMAD who underwent periodic follow-up of computed tomography angiography (CTA) were enrolled. Initial morphologic classification, imaging features and dissection remodeling were analyzed retrospectively. Logistic regression was used to identify predictors for remodeling. Receiver operating characteristics were performed for cutoff threshold.

Results

Zerbib classification was adapted and initial CT appearance divided eighty-nine patients into: type I (15.7%), patent false lumen (FL) with both entry and re-entry; type II (37.1%), “cul-de-sac” shaped FL without re-entry; type III (27.0%), thrombosed FL with ulcer-like-projection (ULP); type IV (18%), intramural hematoma; type V (0%), dissecting aneurysm; and type VI (2.2%), total or partial occlusion of superior mesenteric artery (SMA). Follow-up CTA revealed complete remodeling (33.7%), partial remodeling (16.9%), no change (25.8%), type change (13.5%) and dissection progression (10.1%). There was no dissection-related mortality. Type I (92.9%) sustained patent FL and no angiographic change. Type II showed partial remodeling (42.4%), no change (27.3%) and dissection progression (27.3%), and the length of FL enhancement positively predicted dissection progression with the cutoff of 40.3 millimeters. Type III achieved complete remodeling (58.3%) or evolved into type II (41.7%), and the distance between SMA orifice and ULP negatively predicted type change with the cutoff of 23.5 millimeters. Type IV (87.5%) achieved complete remodeling due to hematoma absorption. One patient underwent stent placement for the evolution of ULP into an enlarged blind-ending FL 2 months after conservation.

Conclusion

After conservation, patent FL with a distal re-entry is no morphological change, FL thrombosis tends to be resolved, and the “cul-de-sac” shaped FL without re-entry is partially shortened, no change or progressively dilated. FL enhancement length ≥ 40.3 millimeters is a predictor for the blinding-end FL enlargement. Thrombosed FL with ULP evolves into a patent “cul-de-sac” shaped FL when the distance between SMA orifice to ULP is less than 23.5 millimeters. A careful follow-up is necessary for the lesions with demonstrated predictors.

Long-term outcome of spontaneous isolated superior mesenteric artery dissection in different angiographic types

OBJECTIVE

This study aimed to compare the follow-up and outcomes of spontaneous isolated superior mesenteric artery dissection (SISMAD) in different angiographic types and to determine the optimal therapeutic options for SISMAD patients.

METHODS

This is a retrospective study of 61 SISMAD patients between December 2010 and January 2019 in a single center. Data analysis consisted of demographics, clinical data, radiology review, treatment, follow-up, and outcomes.

RESULTS

A total of 61 SISMAD patients were reviewed in this study. Median age was 53 (quartile, 47.5-63.0), 90.2% were males with hypertension (50.8%), dyslipidaemia (54.1%), and smoking history (60.7%). Among all, 43 patients underwent periodic follow-up of computed tomography (CT) angiography for follow-up analysis. 11 (25.6%) patients showed "No Change" during follow-up, including 6 type I patients. 23 patients (53.5%) were "Partially Remodelled" and 18 of them were type II patients. 7 "Completely Remodelled" patients (16.3%) were all in type II group. Two type III patients (4.6%) died after the emergent surgical intervention within 30 days.

CONCLUSIONS

Different SISMAD angiographic types present with variant progression. Type I SISMAD may be inclined to remain "unchanged." Type II SISMAD shows a clear trend to remodeling, especially type IIb patients. The progression of type III SISMAD varies in the extent of collateral bypasses.

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.

Management of Spontaneous Isolated Mesenteric Artery Dissection: A Systematic Review

Background and Aims:

There are increasing reports on case series on spontaneous isolated mesenteric artery dissection, that is, dissections of the superior mesenteric artery and celiac artery, mainly due to improved diagnostic capacity of high-resolution computed tomography angiography performed around the clock. A few case–control studies are now available, while randomized controlled trials are awaited.

Material and Methods:

The present systematic review based on 97 original studies offers a comprehensive overview on risk factors, management, conservative therapy, morphological modeling of dissection, and prognosis.

Results and Conclusions:

Male gender, hypertension, and smoking are risk factors for isolated mesenteric artery dissection, while the frequency of diabetes mellitus is reported to be low. Large aortomesenteric angle has also been considered to be a factor for superior mesenteric artery dissection. The overwhelming majority of patients can be conservatively treated without the need of endovascular or open operations. Conservative therapy consists of blood pressure lowering therapy, analgesics, and initial bowel rest, whereas there is no support for antithrombotic agents. Complete remodeling of the dissection after conservative therapy was found in 43% at mid-term follow-up. One absolute indication for surgery and endovascular stenting of the superior mesenteric artery is development of peritonitis due to bowel infarction, which occurs in 2.1% of superior mesenteric artery dissections and none in celiac artery dissections. The most documented end-organ infarction in celiac artery dissections is splenic infarctions, which occurs in 11.2%, and is a condition that should be treated conservatively. The frequency of ruptured pseudoaneurysm in the superior mesenteric artery and celiac artery dissection is very rare, 0.4%, and none of these patients were in shock at presentation. Endovascular therapy with covered stents should be considered in these patients.

Spontaneous dissection of coeliac and superior mesenteric artery: double whammy

Isolated dissection of one of the mesenteric arteries without concurrent involvement of the aorta is a rare clinical entity and an unusual cause of abdominal pain. It usually involves one artery, most commonly the superior mesenteric artery (SMA) followed by the coeliac artery. We are reporting a rare case where both coeliac and SMA were showing dissection. We are reporting a case of 60-year-old hypertensive male who came with worsening abdominal pain for 5 days; CT scan showed coeliac and SMA dissection without any imaging evidence of intestinal ischaemia. He was successfully managed medically with bowel rest and anticoagulation. Two weeks of follow-up CT scan showed no progression or thrombus formation. For complicated cases, percutaneous transluminal angioplasty of a visceral artery or open surgical exploration or hybrid approach is required. However, for stable uncomplicated cases, medical therapy alone is sufficient.

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.

Uncovered stent insertion for isolated superior mesenteric artery dissection

ABSTRACT

The aim of this study is to describe our clinical outcomes in isolated superior mesenteric artery dissection (SMAD) patients that underwent uncovered stent insertion.Between January 2016 and August 2019, consecutive isolated SMAD patients at our center were treated via uncovered stent insertion. Both short- and long-term outcomes in these patients were analyzed.Over the course of the study period, 11 total isolated SMAD patients meeting the criteria for stent insertion at our hospital were treated via uncovered stent insertion. Stent placement across the SMAD site was successful in all patients, with 1 stent being used per patient. There were no instances of procedure-related complications, and the median operative duration was 60 minutes. Patency of the distal superior mesenteric artery and branches thereof was achieved in all cases. Patients experienced progressive SMAD-related symptom relief and were followed for 6 to 49 months (median: 22 months). Over this follow-up period, the obliteration of the dissection was observed within 3 months in all patients. We did not detect any instances of stent occlusion, bowel ischemia, or anti-platelet-related bleeding during the follow-up period.Uncovered stent insertion can achieve favorable short- and long-term outcomes in isolated SMAD patients.

Clinical Manifestations of Symptomatic Spontaneous Dissection of the Celiac and Superior Mesenteric Arteries

Purpose

Spontaneous isolated dissection of the celiac artery (SID-CA) and superior mesenteric artery (SID-SMA) are rare vascular diseases with similar presentation, yet comparative studies have not been reported. In this study, we compared their characteristics with the aim of providing insights into their etiology.

Methods

Materials and Patients diagnosed with symptomatic SID-CA and SID-SMA between July 2009 and December 2018 were included. Demographics, clinical presentation, radiologic findings, treatment strategies, and outcomes were analyzed.

Results

Twenty-one patients with SID-CA and 40 patients with SID-SMA were compared. Demographics and initial abdominal pain characteristics were similar, but pain severity was significantly higher and associated mean fasting time was significantly longer in patients with SID-CA than in those with SID-SMA (fasting time 3.2 vs 2.1 days, P=0.001). Most patients were successfully treated conservatively without recurrent pain or aneurysmal dilatation, but 33.3% patients with SID-CA and 17.5% with SID-SMA required endovascular intervention. More favorable remodeling in terms of dissection regression on follow-up computed tomography was found after stenting, where patients with SID-CA showed better remodeling than those with SID-SMA. The overall median follow-up period was 22-31 months, while for patients with stent insertion, it was 55-77 months, and no stent occlusions were found during this period.

Conclusion

Patients with SID-CA presented with severer and longer-duration abdominal pain than those with SID-SMA. Stenting in both groups showed good long-term patency and favorable remodeling, with a higher regression rate for SID-CA. Based on our results, patients with SID-CA may benefit more from active endovascular intervention.

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.

The impact of endovascular treatment on clinical outcomes of stable symptomatic patients with spontaneous superior mesenteric artery dissection

OBJECTIVE

To evaluate the efficacy and clinical outcomes of endovascular treatment for superior mesenteric artery dissection (SMAD) and its effect on superior mesenteric artery (SMA) remodeling compared with medical management alone after successful initial medical management.

METHODS

In this retrospective analysis, all patients with spontaneous SMAD at a single institution were identified from March 2007 to August 2019. The primary outcomes were freedom from major adverse events (MAEs, a composite of dissection-related death, the recurrence of mesenteric ischemia symptoms, and a requirement for intervention). The secondary outcomes were morphologic remodeling of the dissections and stenosis or occlusion of the SMA.

RESULTS

A total of 94 patients with SMAD who underwent successful initial medical management (91 males; mean age, 50.4 ± 6.3 years) were enrolled in the study. Fifty-seven (60.6%) received medical management alone, and 37 (39.4%) underwent endovascular repair after initial medical management. In the endovascular group, the technical success rate was 86.5% (32 of 37). During a mean follow-up period of 33.6 ± 26.2 months (range, 1-120 months), nine (9.6%) patients experienced a recurrence of abdominal pain, and six had additional interventions for SMAD. The patients in the endovascular group showed more complete or partial remodeling (22 [81.1%] vs 24 [44.4%]; P < .0001) or unchanged dissections (5 [13.5%] vs 23 [42.6%]; P = .0001) than those in the conservative group. Survival analysis showed that the estimated MAE-free survival rates were 95.6%, 88.9%, and 85.4% at 1, 3, and 5 years, respectively. There was a higher freedom from SMA stenosis or occlusion in the endovascular group (log rank P = .046).

CONCLUSIONS

Endovascular treatment and medical management alone result in similar MAE-free survival for patients with SMAD after successful initial medical management. Moreover, endovascular therapy is associated with a higher complete remodeling rate and greater freedom from SMA stenosis or occlusion.

Spontaneous Isolated Celiac Artery Dissection: A Case Report

Introduction

Abdominal pain is a common chief complaint that can represent a wide breadth of diagnoses, ranging from benign to life-threatening. As our diagnostic tools become more sophisticated, we are able to better identify more causes of potentially life-threatening diseases. One such disease that is relatively unfamiliar to clinicians is spontaneous isolated celiac artery dissection (SICAD).

Case Report

We describe a case of a 46-year-old man who presented to our emergency department with a chief complaint of abdominal pain and was found to have a SICAD and was successfully treated with anticoagulation, antihypertensives, and observation.

Conclusion

It is important for emergency physicians to keep this potentially life-threatening condition in mind and to know the appropriate first steps once identified.

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.

Mid-term outcomes of symptomatic isolated superior mesenteric artery dissection with endovascular management

OBJECTIVES

The clinical outcomes, safety, and efficacy of endovascular management are explored for symptomatic isolated superior mesenteric artery dissection (ISMAD).

METHODS

In this retrospective study, 51 consecutive patients with symptomatic ISMAD received endovascular management from three institutions between January 2011 and December 2019.These patients were categorized into group A (endovascular treatment was used as the first-line therapy) and group B(endovascular treatment was used as the second-line therapy). The general epidemiological data, clinical manifestations, first-episode symptoms, treatment process, imaging findings, follow-up outcomes were analyzed from the medical records.

RESULTS

A total of 51 patients with endovascular management were collected in this study. Significant differences were observed between the two groups with respect to the course (150 h vs. 57 h; p < 0.001), intestinal ischemia (26.32% vs. 6,25%; p = 0.04) and dissection length (45.26 ± 13.78 mm vs. 63.37 ± 12.73 mm; p < 0.001). Technical success rate was 90.2% (46/51). There was significant difference in the MOD (42.27 ± 23.41 min vs. 76.63 ± 28.62 min p < 0.001), MPSRT (4.67 ± 2.65 h vs. 7.32 ± 2.49 h, p = 0.02), LOS (9.52 ± 3.72 days vs. 11.86 ± 4.13 days; p = 0.01) between the two groups. The bleeding complication rate was 7.84% (one patient in group A and three patients in group B). A total of 48 (94.12%, 48/51) patients were followed up for a median of 36.51 months (range, 4-87 months). Positive events of the SMA were achieved in 81.25% (39/48), and negative events of the SMA were achieved in 18.75% (8/48) based on the follow-up contrast-enhanced CT scan.

CONCLUSIONS

Endovascular management of symptomatic ISMAD has a high technical success rate and efficient at controlling symptoms. Furthermore, as more positive events occur, endovascular management should be encouraged early when pain persists after conservative management or there are signs of disease progression.

Spontaneous visceral artery dissections in otherwise normal arteries: Clinical features, management, and outcomes compared with fibromuscular dysplasia

OBJECTIVE

Visceral artery dissection with otherwise normal-appearing arteries (VADNA), diagnosed on imaging and suggestive of segmental arterial mediolysis, is a poorly understood disease entity. Study objectives were to define the clinical features, management, and outcomes of patients with VADNA compared with patients with fibromuscular dysplasia (FMD).

METHODS

In this single-center retrospective cohort study, consecutive patients with a diagnosis of VADNA or FMD evaluated in the Mayo Clinic Gonda Vascular Center (January 1, 2000-April 1, 2017) were identified. Patient demographics, symptom presentation, management, composite adverse arterial events (recurrent arterial dissection, stroke or transient ischemic attack, myocardial infarction, mesenteric or renal infarction, or need for revascularization), and overall survival were compared between VADNA and FMD patients.

RESULTS

There were 103 VADNA patients (age [mean ± standard deviation], 51.7 ± 11.0 years; 27.9% female) and 248 FMD controls (49.8 ± 8.9 years; 81.8% female) identified. The most common symptom for VADNA patients was abdominal or flank pain (80.6%). For FMD, chest pain, headache, and dizziness were more frequent presenting complaints. The median follow-up was longer for VADNA patients (42 months; interquartile range, 9-76 months) compared with FMD patients (19 months; interquartile range, 0.6-52 months; P < .001). During this time interval, there were twofold more composite arterial events in the VADNA group compared with the FMD group (17% vs 8.1%; P = .01). This difference was primarily driven by recurrent dissections. All-cause mortality was low and similar for both groups (3.8% vs 0.4%; P = .10).

CONCLUSIONS

VADNA patients carry a higher risk of recurrent arterial events compared with those with FMD. This difference was primarily driven by recurrent dissections.

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.

Long-Term Outcomes of Spontaneous Isolated Superior Mesenteric Artery Dissection

Spontaneous isolated dissection of the superior mesenteric artery (SMAD) is not still well known. We retrospectively analyzed our 30 patients with SMAD to elucidate the treatment strategy and long-term follow-up outcomes. Due to severe abdominal symptom we performed a stents deployment and surgical reconstructive surgery for each one case. Anerysmectomy and bypass surgery was performed for a patient with aneurysmal change. Other 27 patients were managed conservatively. SMAD patients had only two vascular events (renal infarction and graft occlusion), and showed good prognosis for 6-146 (mean 69) months follow-up. We found that there is a few SMAD patients necessary of invasive management at acute phase and that most patients are safely conservatively treated with good prognosis. (This is a translation of J Jpn Coll Angiol 2018; 58: 195-199.).

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.

Small intestinal autotransplantation for spontaneous isolated superior mesenteric artery dissection: A case report

INTRODUCTION

Spontaneous isolated superior mesenteric artery dissection (SISMAD) is a rare differential diagnosis for patients presenting with abdominal pain. Due to limited cases reported, surgical management strategies are poorly defined.

PATIENT CONCERNS

A 54-year-old man presented to our emergency department with a 4-day history of epigastric pain combined with nausea and vomiting. The pain was dull, constant, and unbearable. It was accompanied by abdominal distention, but there was no radiating pain, chills, fever, or hematochezia. The patient did not have a history of abdominal surgeries, or tobacco or illicit drug use.

DIAGNOSIS

A contrast-enhanced computerized tomography (CT) scan demonstrated an isolated and spontaneous superior mesenteric artery dissection with aneurysmal evolution of the false lumen, involving multiple side branches. The middle-lower jejunum and the whole ileum were extensively dilated, and the middle jejunum was ischemic with edema.

INTERVENTIONS

Exploratory laparotomy and autologous small bowel transplantation.

OUTCOMES

The patient was successfully treated using exploratory laparotomy and intestinal autotransplantation (IATx) without bowel resection and had a stable recovery without complications.

CONCLUSION

For patients with severe mesenteric ischemia or those who fail to respond to initial conservative treatment, IATx may be a reasonable treatment strategy.

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.

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%.

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.

A modified endovascular technique for treating spontaneous isolated superior mesenteric artery dissection and the early to medium-term outcomes

Purpose

The spontaneous isolated dissection of superior mesenteric artery (SIDSMA) is a rare medical condition and the treatment remains controversial. This study is to present our refined technique with a Flexor introducer to facilitate stent advancement and its early to medium-term outcomes.

Methods

A total of 16 patients diagnosed with SIDSMA and repaired with endovascular stenting from January 2012 to December 2017 were retrospectively identified. All patients were male, and the average age was 56 years old (range from 48 to 72 years old). Diagnosis was preoperatively confirmed using computed tomography angiography and their morphologic features were measured. A long Flexor introducer was delivered to the true lumen of dissected superior mesenteric artery prior to coaxially advancing a stent. Patient demographics, endovascular procedures and postoperative outcomes were collected for analysis.

Results

Total technical success was 87.5%. Endovascular attempt was unsuccessful in two patients with extensive thrombus, and the guidewire failed to pass through the true lumen. The remaining 14 SMA dissections were successfully repaired with the modified method. Four patients were repaired using bare stents and 10 with covered stents. The average operative duration was 44 ± 18 minutes. Abdominal pain was relieved postoperatively in all cases except one patient with no identified reasons. The median follow-up duration was 17 months (2–63 months). No procedure- or dissection-related symptoms was present during follow up, and postoperative computed tomography angiography showed all stented SMAs were patent.

Conclusions

Coaxial delivery of stents within the introducer can yield high technical success and good clinical outcomes in early to medium term. Extensive thrombus inside SIDSMA is the exclusive cause for endovascular failure with this technique.

Acute Dissection of the Middle Colic Artery Immediately after Endovascular Abdominal Aortic Aneurysm Repair: A Case Report

A 78-year-old man underwent endovascular abdominal aortic aneurysm repair (EVAR) for a true aortic aneurysm. He developed sudden abdominal pain 4 hr after EVAR. Angiography revealed a dissected aneurysm of the middle colic artery (MCA). Despite conservative treatment, follow-up computed tomography revealed an expanded aneurysm of the MCA. We therefore performed coil embolization of the dissected MCA to prevent a rupture of the aneurysm. There has never been a reported case of acute dissection of the MCA immediately after EVAR that was not caused by catheters. In this report, we discuss the possible underlying mechanisms and the optimal therapeutic strategy for this rare complication.

Spontaneous isolated superior mesenteric artery dissection: Systematic review and meta-analysis

OBJECTIVES

Spontaneous isolated superior mesenteric artery dissection (SISMAD) is a rare disease with an incidence of 0.06%. The purpose of the meta-analysis was to identify the outcomes associated with the various treatment options in the management of asymptomatic and symptomatic patients with SISMAD.

METHODS

Eligible studies were selected by searching PubMed, EMBASE, and Cochrane Library. Endpoints were outcome of asymptomatic patients treated conservatively, resolution of symptoms according to the treatment approach, rate of symptomatic patients switched from conservative to the endovascular and/or open repair, characteristics of the dissected lesion, and findings regarding the remodeling of superior mesenteric artery.

RESULTS

We identified 30 studies including 729 patients. Among them, 608 (83.4%) were symptomatic and were managed with conservative (438/72%), and/or endovascular (139/22.8%) and/or open treatment (31/5%). The remaining were asymptomatic and they were treated solely conservatively. A high rate of resolution of symptoms (92.8%) was noted for patients treated conservatively. Conversion from conservative treatment to either endovascular or open procedure was required in 12.3% and 4.4%, respectively. Resolution of symptoms was observed in 100% for those treated with open procedure and 88.8% for those treated endovascularly. The pooled rate of bowel ischemia in patients treated conservatively was 3.75% (95% confidence interval = 1.15-7.27). Complete remodeling was achieved in 32% and partial in 26% of those who were treated conservatively.

CONCLUSIONS

The majority of symptomatic patients with SISAMD were treated conservatively and showed an uncomplicated course and only a small percentage required conversion to endovascular or open repair. This might highlight the benign course of the disease.

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.

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.