Clinical and angiographic follow-up of 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.

Management Strategy and Radiologic Outcomes of Symptomatic Spontaneous Isolated Superior Mesenteric Artery Dissection Based on Angiographic Classification: The Follow-Up Experience in a Single Center

PURPOSE

To investigate the demographics, clinical features, radiologic measurement, treatment, and outcomes of symptomatic spontaneous isolated superior mesenteric artery dissection (SISMAD) according to computed tomography (CT) classification.

METHODS

This retrospective study included 201 patients diagnosed with symptomatic SISMAD from November 2014 to December 2020. Symptomatic spontaneous isolated superior mesenteric artery dissection was categorized into four types based on CT images by Yun's angiographic classification. Their clinical characteristics, images features, treatment methods, and radiological outcomes were comparatively analyzed by CT angiographic types.

RESULTS

SISMADs were categorized into type I (13.9%) patent false lumen (FL) with both entry and re-entry; type IIa (37.3%), blind pouch of FL; type IIb (43.3%), thrombosed FL; and type III (5.5%), and the occlusion of superior mesenteric artery (SMA). Type IIb, the most common SISMAD, showed the largest true lumen (TL) residual diameter and the lowest percentage of TL stenosis. Type III positioned most proximally to SMA origin and had the maximum dissection length. Symptomatic spontaneous isolated superior mesenteric artery dissections underwent conservative (75.1%), endovascular (22.4%), and surgical (2.5%) treatment. Conservative treatment was more frequent in type I (85.7%) and type IIb (83.9%) than in type IIa (65.3%) and type III (45.5%). Endovascular intervention was more commonly utilized in type IIa (32.0%) and type III (36.4%) than in type I (14.3%) and type IIb (14.9%). Conservative patients achieved FL vanishment/shrinkage (57.8%), stabilization (26.6%), and enlargement (15.6%). After conservative treatment, type I showed angiographic FL stabilization; type IIa achieved FL shrinkage (48.1%), stabilization (22.2%), and enlargement (29.6%); type IIb exhibited FL vanishment/shrinkage (92.0%) and enlargement (8.0%). Cumulative rate of stent patency was 92.3% during 6-year follow-up.

CONCLUSIONS

Conservative management with close follow-up is initially provided especially for types I and IIb. Morphological stabilization is more frequent in type I of patent FL with entry and re-entry. False lumen vanishment or shrinkage was more likely to occur in type IIb due to the thrombus absorption. Endovascular intervention has excellent long-term in-stent patency and is predominantly utilized in types IIa and III. Blood flow sustained into a blind-ending FL causes the TL compression and stenosis in type IIa. Type III with the occlusion of SMA has the high risk of bowel ischemia.

CLINICAL IMPACT

According to Yun's angiographic classification of spontaneous isolated superior mesenteric artery dissection (SISMAD), type I (13.9%) has patent true and false lumen and the morphological pattern is maintained stable; type IIa (37.3%) possesses a patent blind-ending false lumen which might shrink, remain unchanged, or enlarge; and endovascular intervention is suggested when conservative treatment failed; type IIb (43.3%) recovers spontaneously due to the absorption of false lumen thrombus and conservative treatment is preferentially considered; type III (5.5%) with the occlusion of main trunk carries a high risk of bowel necrosis, early endovascular intervention is proposed, and open surgery might be necessary.

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.

The value of treatment choice and clinical prognosis for Riolan's arch in chronic superior mesenteric artery ischaemic disease

OBJECTIVE

To explore the value of treatment choice and clinical prognosis for Riolan's arch in chronic superior mesenteric artery (SMA) ischaemic disease in vascular surgery.

METHODS

The clinical data of 215 patients with SMA ischaemic disease (41 cases with Riolan's arch and 174 cases without) admitted to the Department of Vascular Surgery, Affiliated Drum Tower Hospital, Medical School of Nanjing University (China) from January 2019 to April 2023 were reviewed. Clinical characteristics, imaging findings, treatment, perioperative complications, and patient follow-up data were analysed to observe the impact of Riolan's arch on the prognosis of patients with SMA ischaemic disease.

RESULTS

There were significant differences in body mass index (Riolan's arch group: 22.82 ± 3.28 vs 24.03 ± 4.26 in non-Riolan's arch group, P = 0.049), Takayasu's arteritis (4.9% vs 0, respectively, P = 0.036), and secondary intervention (3.3% vs 1.9%, respectively, P < 0.001) between the two groups. Propensity score matching was used to exclude the effect of baseline data on patient outcomes. There were significant differences related to therapy method (conservative treatment, Riolan's arch group: 24.1% vs 39.7% in the non-Riolan's arch group; operative treatment, Riolan's arch group: 51.7% vs 20.7% in the non-Riolan's arch group, P = 0.014), as well as in-hospital time (9.79 ± 4.20 vs 6.86 ± 4.32, respectively, P = 0.011). There was no statistically significant difference in Kaplan-Meier curves between the two groups (log-rank test P = 0.476).

CONCLUSIONS

Riolan's arch plays an important compensatory role in SMA ischaemic disease, especially in chronic disease. We found significant differences in the treatment methods and length of hospital stay of Riolan's arch, which may suggest that Riolan's arch has some reference value in the choice of treatment mode.

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.

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.

Multimodal Study of the Superior Mesenteric Artery Wall

BACKGROUND

To quantitatively analyze histological and fiber structure of the superior mesenteric artery (SMA) wall and to further explore the possible relationship between the architecture and histology changes of vessel wall and the occurrence of related diseases.

METHODS

Histological and fiber structure analysis were performed on SMA specimens obtained from 22 cadavers. The SMA specimens were divided into initial, curved, and distal segments, and each segment was separated into the anterior and posterior walls.

RESULTS

From the initial to the curved to the distal segment, the ratio of elastin decreased (31.4% ± 6.0%, 21.1% ± 5.8%, 18.6% ± 4.7%, respectively; P < 0.001), whereas the ratio of smooth muscle actin (24.5% ± 8.7%, 30.5% ± 6.8%, 36.1% ± 7.3%, respectively; P < 0.001) increased. Elastic fiber longitudinal amplitude of angular undulation was highest in the initial segment [7° (3.25°, 15°)] and lowest in the curved segment [2° (1°, 5°)]. In SMA curved segment, the anterior wall, when compared with the posterior wall, demonstrated a lower ratio of elastin (19.0% ± 5.8% vs. 23.3% ± 5.0%; P = 0.010) and collagen (41.4% ± 12.3% vs. 49.0% ± 10.2%; P = 0.032), a lower elastic fiber longitudinal amplitude of angular undulation [1° (1°, 5°) vs. 3° (2°, 5.25°); P = 0.013], a lower average fiber diameter (8.06 ± 0.36 pixels vs. 8.45 ± 0.50 pixels; P = 0.005), and a lower average segment length (17.96 ± 1.59 pixels vs. 20.05 ± 2.33 pixels; P = 0.001).

CONCLUSIONS

SMA wall structure varies along the circumferential and axial directions, the presence of dense undulated elastic fiber protects the SMA initial segment of from dissection and aneurysm, but highly cross-linked collagen fiber here increases the likelihood of plaque formation. In the anterior wall of the curved segment, lower elastin and collagen content, lower elastic fiber undulation, and higher degree of collagen fiber cross-linking leads to the occurrence of SMA dissection and aneurysm. In the distal segment, high levels of vascular smooth muscle cells and bundles of long collagen fiber offer protection against the development of SMA-related diseases.

In-stent Restenosis After Stenting for Superior Mesenteric Artery Dissection Is Associated With Stent Landing Zone: From Clinical Prediction to Hemodynamic Mechanisms

OBJECTIVE

To identify risk factors for in-stent restenosis (ISR) in patients undergoing stent placement for superior mesenteric artery dissection (SMAD) and to determine the hemodynamic mechanism underlying ISR.

METHODS

For this retrospective study, patients with SMAD who had ISR after stent placement were included in the ISR group, and age- and sex-matched patients with SMAD who did not experience ISR after stent placement were included in the control group. Clinical, imaging, and hemodynamic data were assessed. Multivariable regression was used to identify independent ISR risk factors. Structural and fluid dynamics simulations were applied to determine the hemodynamic mechanism underlying the occurrence of ISR.

RESULTS

The study population included 26 patients with ISR and 26 control patients. Multivariate analysis demonstrated that stent-to-vascular (S/V) ratio (odds ratio [OR], 1.14; 95% confidence interval [CI]: 1.00-1.29; p=0.045), stent proximal position >10 mm away from the SMA root (OR, 108.67; 95% CI: 3.09-3816.42; p=0.010), and high oscillatory shear index (OSI) area (OR, 1.25; 95% CI: 1.02-1.52; p=0.029) were predictors of ISR. In structural and fluid dynamics simulations, a stent proximal position near the abdominal aorta (AA) or entering into the AA reduced the contact area between the proximal struts of the stent and the vascular wall, and alleviated the distal lumen overdilation.

CONCLUSION

The S/V ratio, stent proximal position away from the SMA root (>10 mm), and high OSI area are independent risk factors for ISR in patients with SMAD undergoing stent placement. Deploying the proximal end of the stent near the AA or entering into the AA appears to improve the hemodynamic environment in the SMA lumen and ultimately reduce the risk of ISR.

CLINICAL IMPACT

In-stent restenosis is an uncommon but potentially catastrophic complication after stent placement for the management of superior mesenteric artery dissection. This study identified risk factors for in-stent restenosis and demonstrated that, as long as the stent can fully cover the dissection range, deploying the proximal end of the stent near the abdominal aorta or less entering into the abdominal aorta may reduce the risk of in-stent restenosis in this patient population.

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.

Differentiating between segmental arterial mediolysis and other arterial vasculopathies to establish an early diagnosis - a systematic literature review and proposal of new diagnostic criteria

Segmental arterial mediolysis (SAM) is a rare vascular disease, characterized by acute but transient vulnerability of the wall of medium-sized arteries. The most characteristic feature of SAM is its biphasic course: an injurious phase marked by acute weakness of the arterial wall leading to acute dissection and/or hemorrhage, followed by a reparative phase in which granulation tissue and fibrosis restore the injured arterial wall. Residual stenosis, aneurysms, and/or arterial wall irregularities may remain visible on future imaging studies. Differentiating between SAM and other arterial vasculopathies is difficult due to its similarities with many other vascular diseases, such as vasculitis, fibromuscular dysplasia, inherited connective tissue disorders, and isolated visceral artery dissection. In this systematic review, we provide an overview on SAM, with an emphasis on the differential diagnosis and diagnostic work-up. We propose new diagnostic criteria to help establish a prompt diagnosis of SAM, illustrated by case examples from our multidisciplinary vascular clinic.

Insights into acute mesenteric ischaemia: an up-to-date, evidence-based review from a mesenteric stroke centre unit

Radiologists play a central role in the diagnostic and prognostic evaluation of patients with acute mesenteric ischaemia (AMI). Unfortunately, more than half of AMI patients undergo imaging with no prior suspicion of AMI, making identifying this disease even more difficult. A confirmed diagnosis of AMI is ideally made with dynamic contrast-enhanced CT but the diagnosis may be made on portal-venous phase images in appropriate clinical settings. AMI is diagnosed on CT based on the identification of vascular impairment and bowel ischaemic injury with no other cause. Moreover, radiologists must evaluate the probability of bowel necrosis, which will influence the treatment options.AMI is usually separated into different entities: arterial, venous, non-occlusive and ischaemic colitis. Arterial AMI can be occlusive or stenotic, the dominant causes being atherothrombosis, embolism and isolated superior mesenteric artery (SMA) dissection. The main finding in the bowel is decreased wall enhancement, and necrosis can be suspected when dilatation >25 mm is identified. Venous AMI is related to superior mesenteric vein (SMV) thrombosis as a result of a thrombophilic state (acquired or inherited), local injury (cancer, inflammation or trauma) or underlying SMV insufficiency. The dominant features in the bowel are hypoattenuating wall thickening with submucosal oedema. Decreased enhancement of the involved bowel suggests necrosis. Non-occlusive mesenteric ischaemia (NOMI) is related to impaired SMA flow following global hypoperfusion associated with low-flow states. There are numerous findings in the bowel characterised by diffuse extension. An absence of bowel enhancement and a thin bowel wall suggest necrosis in NOMI. Finally, ischaemic colitis is a sub-entity of arterial AMI and reflects localised colon ischaemia-reperfusion injury. The main CT finding is a thickened colon wall with fat stranding, which seems to be unrelated to SMA or inferior mesenteric artery lesions. A precise identification and description of vascular lesions, bowel involvement and features associated with transmural necrosis is needed to determine patient treatment and outcome.

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 isolated superior mesenteric artery dissection: A case report and brief analysis

This case report describes the clinical presentation, diagnostic approach, and treatment strategies for a 58-year-old male patient diagnosed with spontaneous isolated superior mesenteric artery dissection (SISMAD). The patient presented with suddenonset abdominal pain and was diagnosed with SISMAD using computed tomography angiography (CTA). SISMAD is a rare but potentially serious condition that can lead to bowel ischemia and other complications. Management options include surgery, endovascular therapy and conservative management with anticoagulation and close observation. The patient was managed conservatively with antiplatelet therapy and close follow-up. During hospitalization, he received antiplatelet therapy and was closely monitored for signs of bowel ischemia or other complications. The patients' symptoms gradually improved over time, and he was eventually discharged on oral mono- antiagreggation therapy. Clinical follow-up showed a significant symptimatic improvement. Conservative management with antiplatelet therapy was chosen due to the absence of bowel ischemia signs and overall stable clinical condition of patient. This report emphasizes the importance of prompt recognition and management of SISMAD to prevent potentially life-threatening complications. Conservative management with antiplatelet therapy can be a safe and effective treatment option for SISMAD, especially in cases without evidence of bowel ischemia or other complications.

The management of spontaneous isolated celiac artery dissection: A case report and literature review

OBJECTIVES

Spontaneous isolated celiac artery dissection (SICAD) without associated aortic dissection is a rare disease. Complications are ischemia, aneurysm formation, and rupture. Different treatment options have been reported for managing SICAD, including conservative management, endovascular intervention, and open surgery. Despite the increased recognition of this disease, there are no consensus guidelines on management of this condition. To improve the knowledge and treatment of this disease, a case of SICAD was reported.

METHODS AND RESULTS

We describe the case of a 57-year-old woman with SICAD whose symptoms improved after endovascular treatment when conservative treatment failed and systematically analyze the management strategy for patients with SICAD.

CONCLUSIONS

SICAD is a rare disease and has no universally agreed upon guidelines for treatment. Most patients can be first treated conservatively for dissection with strict blood pressure control, antithrombotic therapy, and intensive surveillance. For SICAD patients with aneurysms located in the celiac trunk, stent grafts can be used in such patients without affecting the branch blood supply.

Isolated Superior Mesenteric Artery Dissection following Blunt Trauma: A Case Report

Isolated superior mesenteric artery dissection (ISMAD) is rare, with symptoms ranging from asymptomatic to acute intestinal ischemia. Risk factors for ISMAD include hypertension, atherosclerosis, abnormal elastic fibers, and pregnancy. In the present case, blunt trauma, which has not been previously reported, was suggested as a risk factor. A 46-year-old man was brought to the emergency room after he was found unconscious after a motor vehicle collision. At presentation, he had no abdominal symptoms; however, on the fourth day of admission, he presented with severe abdominal pain and vomiting. A contrast-enhanced computed tomography scan revealed an ISMAD with associated intestinal ischemia and necrosis; hence, emergency surgery was performed. Herein, we report a case of ISMAD caused by blunt abdominal trauma.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

Analysis of safety and efficacy of conservative treatment and endovascular treatment in patients with spontaneous isolated mesenteric artery dissection

Background

Spontaneous isolated superior mesenteric artery dissection (SISMAD) is a rare disease with abdominal pain as the main clinical manifestation, but its optimal treatment strategy has not yet been determined. Based on this, this study explored a safe and effective treatment method by analyzing and comparing the safety and efficacy of conservative treatment and endovascular treatment in SISMAD patients.

Methods

The clinical and imaging data and treatment effects of 85 patients with SISMAD who were admitted to the General Surgery Department of the 900th Hospital of the Joint Logistics Support Force of the Chinese People's Liberation Army from January 2008 to December 2020 were retrospectively analyzed. Two groups were treated, the data of patients in conservative treatment group and endovascular treatment group were analyzed, and a safe and effective treatment method for SISMAD was discussed.

Results

The mean follow-up time was 36.58 ± 25.03 months. The success rate of interventional operation was 86.11% (31/36), and the operation failed because the guide wire could not enter the true lumen in four cases. One case was terminated due to poor physical condition of the patient who could not tolerate surgery. There were no significant differences in gender, body mass index, clinical manifestations, and past history between conservative treatment and endovascular treatment (P > 0.05), but in age, superior mesenteric artery-distal aorta angle, distance from the superior mesenteric artery opening to dissection, dissection length, and true lumen stenosis. There was a statistical difference between the two groups in the rate and Yun classification (P < 0.05).

Conclusions

Conservative treatment is effective for most symptomatic SISMAD patients, and close monitoring is required; for patients with persistent symptoms and severe true lumen stenosis (especially Yun classification type III), endovascular treatment is preferred; endovascular treatment is mainly based on endovascular bare stent placement. Patients receiving stent implantation may suffer from stent stenosis or occlusion in the long term, and most of them have no obvious symptoms of intestinal ischemia; the prognosis is good.

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.

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.

The pathogenesis of superior mesenteric artery dissection: An in-depth study based on fluid-structure interaction and histology analysis

OBJECTIVE

To explore the role of hemodynamic factors in the occurrence of superior mesenteric artery (SMA) dissection (SMAD) using a fluid-structure interaction (FSI) simulation method, and to identify histopathologic changes occurring in the wall of the SMA.

METHODS

A total of 122 consecutive patients diagnosed with SMAD and 122 controls were included in this study. Hemodynamic factors were calculated using a FSI simulation method. Additionally, SMA specimens obtained from 12 cadavers were stained for histological quantitative analysis.

RESULTS

The mean aortomesenteric angle (59.7° ± 21.4° vs 48.2° ± 16.8°; p < .001) and SMA maximum curvature (0.084 ± 0.078 mm^-1 vs 0.032 ± 0.023 mm^-1; p < .001) were higher in SMAD patients than the controls. Larger aortomesenteric angles and SMA curvatures were associated with higher and more concentrated wall shear stress at anterior wall of the SMA curve segment, co-located with the dissection origins. The mean thickness of media (325.18 ± 44.87 µm vs 556.92 ± 138.32 µm; p = .003) was thinner in the anterior wall of the SMA curve than in the posterior wall. The area fractions of elastin (17.96% ± 3.36% vs 27.06% ± 4.18%; p = .002) and collagen (45.43% ± 6.89% vs 55.57% ± 7.57%; p = .036) were lower in anterior wall of the SMA curve than in posterior wall.

CONCLUSION

Increased aortomesenteric angle and SMA curvature are risk factors for SMAD. Both of these factors can cause local hemodynamic abnormalities, which can lead to histopathologic changes in anterior wall of SMA.

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.

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.

Diagnosis of spontaneous isolated superior mesenteric artery dissection with ultrasound: A case report

BACKGROUND

Spontaneous isolated superior mesenteric artery dissection (SISMAD) is a rare disease that originates from the superior mesenteric artery, without the presence of aortic and other arterial dissections. Most cases are diagnosed using contrast-enhanced computed tomography (CECT), whereas the application of ultrasound is less common.

CASE SUMMARY

Here, we report a case of SISMAD with sudden epigastric pain that worsened as the main symptom after eating. The patient had a long history of hypertension with unknown blood pressure control but no history of smoking or alcohol consumption. This case was initially diagnosed using ultrasound and the results were later confirmed by CECT. After admission, the patient fasted, followed by parenteral nutrition support and fluid supplementation to maintain electrolyte and acid–base balance. Metoprolol succinate sustained-release tablets and aspirin were given as nonoperative treatments. After 1 wk, the symptoms improved, and the patient was discharged. During telephone follow-up, the patient did not develop similar symptoms.

CONCLUSION

Whether ultrasound can be used as a routine and noninvasive imaging method for the diagnosis of SISMAD needs further exploration.

Clinical characteristics and misdiagnosis of spontaneous isolated superior mesenteric artery dissection

Background

Spontaneous isolated superior mesenteric artery (SMA) dissection (SISMAD) is a rare disease with a potentially fatal pathology. Due to the lack of specificity of clinical characteristics and laboratory tests, misdiagnosis and missed diagnosis are often reported. Therefore, the aim of this study was to investigate the clinical characteristics and misdiagnosis of SISMAD.

Methods

In a registry study from January 2013 to December 2020, 110 patients with SISMAD admitted to the First Affiliated Hospital of Wenzhou Medical University were enrolled. Descriptive methods were used to analyse clinical characteristics, laboratory data, diagnostic method or proof, misdiagnosed cases, plain computed tomography (CT) findings and dissection features. To study the relationship between dissection features and treatment modality, the selected patients were classified into the conservative group (n = 71) and the non-conservative group (n = 39). The Chi-square test and Student’s t-test were used to compare the conservative and non-conservative groups.

Results

One hundred ten patients with SISMAD, including 100 (90.9%) males and 10 (9.1%) females, with a mean age of 52.4 ± 7.6 years, were enrolled in the study. Relevant associated comorbidities included a history of hypertension in 43 cases (39.1%), smoking in 46 cases (41.8%), and alcohol consumption in 34 cases (30.9%). One hundred four patients (94.5%) presented with abdominal pain. Abnormalities in the C-reactive protein lever, white blood cells count and D-dimer lever were the 3 most common abnormal findings. There were 32 misdiagnosis or missed diagnosis. Fourteen cases were misdiagnosed because of insufficient awareness. Twelve cases were misdiagnosed because of disease features. Twenty cases were misdiagnosed as SMA embolism. Among them, There were 15 cases of Yun type IIb SISMAD. Sixty-six patients underwent plain CT. The maximum SMA diameter was 12.1 (11.3–13.1) mm, and the maximum SMA diameter was located on the left renal vein (LRV) plane in 68.2% of cases. Dissection features observed on contrast-enhanced CT (CECT), CT angiography (CTA), or digital subtraction angiography (DSA) showed that there were 70 cases (63.6%) of Yun type IIb SISMAD, the maximum SMA diameter was 13.0 ± 2.4 mm, the location of the maximum SMA diameter was on the LRV plane in 64.5% of cases, and 7.3% of cases were complicated with intestinal obstruction, including bowel necrosis in 3.6% of cases. There were differences between the conservative group and non-conservative groups in the residual true lumen diameter or degree of true lumen stenosis and the presence of intestinal obstruction or bowel necrosis (all P < 0.05).

Conclusion

For SISMAD, misdiagnosis and missed diagnosis were usually caused by insufficient awareness and disease features. SISMAD should be considered in the differential diagnosis of patients presenting with unexplained abdominal pain, especially males, patients in the 5th decade of life, patients with hypertension, and patients with an enlarged SMA diameter or a maximum SMA diameter located on the LRV plane on plain CT. Mesenteric CTA or CECT should be recommended for the investigation of these conditions.

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.

Combination treatment for superior mesenteric artery dissection: therapeutic challenge

Dissection of the superior mesenteric artery is a rare cause of abdominal pain, with a variable clinical picture. It is difficult to diagnose and there is no consensus on treatment options, which range from conservative treatment to open, endovascular, or combination repair. We describe the case of a 45-year-old man with isolated dissection of the superior mesenteric artery and persistent abdominal pain after conservative treatment had been attempted. He underwent open surgical revascularization due to the location and complexity of the dissection. Treatment consisting of endarterectomy, arterioplasty with bovine pericardium patch, and retrograde access to open the mesenteric artery with a stent was successful. Abdominal angina was completely resolved after the condition had stabilized. A combination of open and endovascular approaches should be considered as treatment for cases of isolated complex dissection of the superior mesenteric artery.

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 intramural hematoma of the superior mesenteric artery: a single-center experience

PURPOSE

To investigate the clinical course and optimal management for spontaneous isolated intramural hematoma of the superior mesenteric artery (SIHSMA).

METHODS

From January 2015 to October 2020, a total of 31 consecutive patients with SIHSMA were included in this study. The demographics, clinical features, treatment details, imaging information, and outcomes were reviewed.

RESULTS

There were 24 males and 7 females, with a mean age of 54.9 years (SD 6.9 years). Seven patients (7/31, 23%) were associated with ulcer-like projection (ULP), one patient (1/31, 3%) with intramural blood pool (IBP), and the remaining twenty-three patients (23/31, 74%) had no ULP or IBP. All patients were initially managed conservatively and underwent a median follow-up of 25.5 months (IQR 14.5, 39.9), which showed 3 patients (3/31, 10%) subsequently underwent stenting (2 within 7 days and 1 after 1.5 months), 1 patient (1/31, 3%) progressed to a localized dissection 7 months later but remained stable and asymptomatic until the time of writing, and the remaining patients (27/31, 87%) had no progression. In the present cohort, the overall survival was 100% (31/31). The free-from progression and stenting rate under conservative treatment was 87% (27/31). The invasive intervention rate was 10% (3/31). The natural complete regression rate of IMH in patients without ULP was higher than those with ULP (91% [21/23] vs. 29% [2/7], p = .003).

CONCLUSION

The majority of patients with SIHSMA can be managed conservatively. Patients with ULP seemed to have a lower IMH regression rate than those without ULP.

Conservative management of spontaneous isolated superior mesenteric artery dissection: A case report

Spontaneous isolated superior mesenteric artery dissection (SISMAD) is a rare and potentially fatal cause diagnosis presenting with acute abdominal; however, because of its rarity, the pathogenic factors of SISMAD remain unknown and no clear cause has been found. Moreover, there is a lack of evidence-based treatment guidelines.

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.

Isolated Spontaneous Mesenteric Artery Dissection: A Rare Entity

Isolated spontaneous dissection of the mesenteric artery in the absence of involvement of the aorta or its branches is an uncommon vascular entity. It is generally seen in males and presents with gastrointestinal symptoms due to mesenteric ischemia. However, asymptomatic cases are increasingly being diagnosed due to increased use of computed tomography (CT) angiography. The course is usually self-limiting, and conservative management with bowel rest, strict blood pressure control, anticoagulants, sedatives for pain, and close observation usually suffices. Surgery or endovascular stenting is usually reserved for those exhibiting bowel ischemia or impending rupture. We report a case of a young female with isolated spontaneous mesenteric artery dissection with thrombus, which did not improve with medical therapy and was managed promptly by surgery due to the presence of bowel ischemia.

A case report of an isolated superior mesenteric artery dissection caused by childbirth

Background

The isolated superior mesenteric artery dissection (SMAD) is a rare and sporadic cause of acute abdominal pain. It most frequently affects male patients in their fifth to sixth decades, while our patient was a young woman who delivered a baby before the onset of abdominal pain. Possible risk factors for SMAD include hypertension, arteriosclerosis, abnormalities in elastic fibres, trauma, and pregnancy. In our case, delivery was suggested as a risk factor, which has not been reported previously.

Case presentation

A 27-year-old woman complained of acute severe upper abdominal pain and vomiting for 2 days after delivery. The patient had no significant medical history. Physical examination revealed epigastric mild tenderness. All routine blood tests, blood coagulation analysis, liver function tests and abdomen computed tomography showed no remarkable findings. Computed tomography angiography revealed a marked dissection 3.5 cm below the superior mesenteric artery ostium. Since distal blood flow existed and the patient was in a puerperal state with no evidences of mesenteric ischemia, she was managed conservatively, including intestinal rest by fasting, parenteral nutritional support and antibioticis, without anticoagulants or antiplatelet agents. Fortunately, she recovered smoothly and had no recurrence.

Conclusions

SMAD is a rare and sporadic cause of acute abdominal pain that occurs in young women after delivery.

Symptomatic spontaneous superior mesenteric artery dissection treated with endovascular stent repair

Spontaneous isolated superior mesenteric artery dissection (SISMAD) is a rare condition in which patients develop an isolated dissection of the superior mesenteric artery without traumatic or iatrogenic causes. We present the case of a 52-year-old woman who presented with SISMAD and underwent endovascular stenting as her symptoms failed to respond to medical management. We also spend the bulk of the report discussing the current literature on management of SISMAD.

Evaluation of isolated abdominal visceral artery dissection with multi-scale spiral computed tomography: a retrospective case series

Background

To evaluate the role of multi-slice spiral computed tomography (MSCT) angiography in the diagnosis of spontaneous isolated visceral artery dissection (SIVAD).

Methods

Twenty-seven patients with abdominal SIVAD were included in the study. The MSCT scans of the patients were subjected to various post-processing techniques to visualize the visceral artery wall. Clinical features including arterial dissection, thrombosis, dissection length, true/false lumen, and complications were recorded.

Results

Type I, IIa, and IIb SIVADs were observed in 11, 6, and 10 patients, respectively. Superior mesenteric artery (SMA) dissection was the most common (n = 16), followed by abdominal aortic dissection (n = 6), splenic artery dissection (n = 2), renal artery dissection (n = 2), and splenic artery dissection (n = 1). One patient with SMA dissection suffered small intestine ischemia, 1 with splenic artery dissection had splenic infarction, and 1 patient with left renal artery dissection experienced renal infarction. The false lumen was bigger than the true lumen in 20 patients, with 9 patients having thrombus. The true lumen was bigger than the false lumen in 7 patients.

Conclusions

MSCT angiography is a valuable technique in the diagnosis and treatment of patients with SIVAD. Patients with abdominal pain suspected due to SIVAD should be examined with MSCT angiography for early detection of SIVAD.

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.

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.

Clinical features and management strategy of symptomatic spontaneous isolated celiac artery dissection

OBJECTIVES

The aim of this study was to evaluate the clinical features and management strategy for patients with symptomatic spontaneous isolated celiac artery dissection (SICAD).

METHODS

In this retrospective study, consecutive patients with symptomatic SICAD from two institutions were included. The demographics, clinical manifestations, comorbidities, imaging findings and treatment strategy selection were obtained from the medical records. The general epidemiological data, treatment regimens and clinical and follow-up outcomes were analysed.

RESULTS

Patients were divided into the conservative treatment group (group A, n = 26) and endovascular treatment group (group B, n = 11). Of these 37 patients, extent of dissection in both groups included only celiac trunk (61.54%% vs. 18.18%, p = 0.03), common hepatic artery (CHA) and splenic artery (SA) (3.85%% vs. 54.55%, p = 0.001), CHA (7.69% vs. 18.18%, p = 0.57), SA (23.08% vs. 9.09, p = 0.65) and left gastric artery (LGA) (3.85% vs. 54.55%, p = 0.99). Of note, the extension of the lesion in group A was shorter than that in group B. In addition, there were significantly more type IIb in group A than in group B (42.31% vs. 9.09%, p = 0.06) and the mean length of dissection in group A was 42.3 ± 54.71 mm which was significantly shorter than that in the group B 58.45 ± 3.71 mm (p =0.04). During a median follow-up of 11.5 months, the 1, 3, 6 and 12 month follow-ups were completed in 100% (37/37), 100% (37/37), 94.59% (35/37) and 91.19% (34/37) of patients, respectively. The cumulative rate of persistent disease stability in patients with endovascular treatment group was higher than in that conservative treatment group at the 3, 6, 9 and 12 months (50% vs. 16.67%, p = 0.001; 80% vs. 37.5%, p =0.03; 100% vs. 62.5%, p = 0.012;100% vs. 91.67%, p = 0.02 respectively).

CONCLUSION

Most symptomatic SICAD have a tendency to persistent disease stability after conservative treatment. Risk factors for failed conservative treatment were length of dissection and branch involvement. Furthermore, endovascular treatment was associated with a high technical success and persistent disease stability rate, which might be reserved for patients with failed conservative treatment.

Clinical implications of perivascular fat stranding surrounding spontaneous isolated superior mesenteric artery dissection on computed tomography

Patients with spontaneous isolated superior mesenteric artery (SMA) dissection (SISMAD) usually present with acute or chronic abdominal pain and are admitted to the emergency or digestive diseases department to undergo auxiliary examinations, typically abdominal plain CT or contrast-enhanced CT (CECT). Plain CT is the most crucial examination in emergency radiology. An enlarged SMA diameter and perivascular fat stranding (PFS) on plain CT, though non-specific, may be the only indications for SISMAD. These results may be easily overlooked and the diagnosis of SISMAD may be missed. However, PFS around the SMA on CT may be the only indicator of the possible presence of SISMAD, particularly during the early stage when there are no massive changes in the vascular wall. The present study aimed to determine whether PFS surrounding the SMA on CT may help with the diagnosis of SISMAD by indicating the requirement for further examination. The data of 161 consecutive patients with SMA dissection who underwent abdominal CECT or underwent SMA CT angiography (CTA) after abdominal plain CT between February 2015 and February 2018 were retrospectively reviewed. SMA diameter, classification, PFS, complications, comorbidities and treatments were analyzed. The results demonstrated that SISMAD with PFS was significantly associated with admission type (emergency), clinical manifestations (abdominal pain), diagnostic modality and dissection subtype. On plain CT, PFS surrounding the SMA may be a marker for SISMAD, particularly in the emergency setting, and indicates the requirement for CTA examination.

Revascularization of Isolated Superior Mesenteric Artery Dissection for Post-Mesenteric Infarction Exudative Enteropathy: The Contribution of a Multidisciplinary Care Teamwork

BACKGROUND

Isolated dissection of the superior mesenteric artery (SMA) is increasingly diagnosed; the conservative treatment appears to be the best option when blood supply is maintained. However, some patients require a more invasive attitude, due to acute or chronic ischemic complication. Multidisciplinary care within a health-care network improves medical and surgical support. We present a case of chronic complication of isolated SMA dissection requiring a revascularization, followed by bowel resection.

CASE PRESENTATION

A 49-year-old man presented abdominal pain secondary to necrotizing enterocolitis of unknown cause. An isolated small bowel resection with immediate restoration of continuity was first performed to remove the necrotic tissue. The patient developed post-ischemic exudative enteropathy and small intestinal bacterial overgrowth (SIBO). Re-examination of the first computed tomography (CT) scan revealed an isolated dissection of the SMA that had not been diagnosed. The patient was then successfully treated by superior mesenteric revascularization, and after recovering, he underwent small bowel resection for chronic ischemia.

CONCLUSIONS

SMA revascularization has to be performed in case of SMA dissection complicated of bowel ischemia. Enteropathy is a rare complication of chronic mesenteric ischemia requiring digestive and vascular management in a dedicated health-care team.

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.

Isolated Superior Mesenteric Artery Dissection Mimicking Impending Rupture of Abdominal Aortic Aneurysm

Patient: Male, 66-year-old

Final Diagnosis: Isolated superior mesenteric artery dissection

Symptoms: Abdominal and back pain

Medication:—

Clinical Procedure: —

Specialty: Surgery