Isolated Superior Mesenteric Artery Dissection Research Articles

Isolated superior mesenteric artery dissection with concomitant vascular aberrancy: Extremely rare cases and clinical implications.

Vascular aberrancy of superior mesenteric artery (SMA) may contribute to the occurrence of SMA dissection. However, there is no direct evidence to support this hypothesis. Etiology, natural history, classification, and treatment options of ISMAD are still in controversial at some degree. We also review the current understanding of ISMAD based on our results. Out of 57 patients, 2 cases of isolated superior mesenteric artery dissection (ISMAD) which concomitant with replaced common hepatic artery with SMA origin, are first reported. Two patients have no any typical etiological factors, such as atherosclerosis, hypertension, long-term smoking, and connective tissue disease. The contrast-enhanced computed tomography and (or) angiography showed concomitant SMA aberrancy. They have 81.2°, 132.7° SMA angle, respectively. After conservative treatment of 4, 6days, respectively, these 2 patients were discharged smoothly. Vascular aberrancy may be a new identified risk factor for ISMAD. Even in ISMAD cases with vascular aberrancy, conservative treatment still can be used as first line therapy.

Non-Contrast Magnetic Resonance Imaging of Isolated Superior Mesenteric Artery Dissection.

Non-Contrast Magnetic Resonance Imaging of Isolated Superior Mesenteric Artery Dissection.

Retraction: Isolated Superior Mesenteric Artery Dissection After Methamphetamine Use: A Rare Adverse Effect.

[This retracts the article DOI: 10.7759/cureus.19551.].

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

AbstractIsolated 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.

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

To evaluate the safety and efficacy of placing bare self-expanding metal stent (SEMS) for treating isolated superior mesenteric arterial dissection (ISMAD). 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. A total of 26 patients were included in this study. Among the patients, 25 were admitted due to persistent abdominal pain, and one 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 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 non-acute disease (P = 0.423). Incomplete remodeling was noted in two patients. Distal stent occlusion without SMA-related symptoms was seen in one patient. Proximal stent stenosis occurred in one patient, and re-stenting 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. 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.

Single Center Experience of Operative Management in Isolated Mesenteric Artery Dissections

Isolated mesenteric dissection of vessels is a rare occurrence with management strategies dependent on patient presentation. The study aimed to evaluate a single institution's experience on patient characteristics, treatment modalities, and outcomes on operative vs nonoperative management of mesenteric dissection. Patients from a single institution between January 2017 and November 2022 with diagnosis of superior mesenteric artery (SMA) or celiac artery dissection and its branches were included. Patients with concomitant descending aortic dissection were excluded. Patient demographics, imaging, treatments, and follow-up data was collected and underwent descriptive statistical analysis. All SMA dissections were categorized using the modified Sakamoto classification (types I-VI), with type VI indicating total occlusion of vessel due to dissection. There were 30 patients with diagnosis of isolated mesenteric dissection. Mean age was 61 years, and the majority were male (86%), Asian (60%), and symptomatic (70%). Majority had isolated SMA dissection (n = 19; 63.3%) with the remainder having isolated celiac (n = 9; 30%) or concomitant SMA and celiac dissection (n = 2; 6.7%). Twenty-one patients had involvement of SMA and categorized using the modified Sakamoto Classification (n = 5 type I, n = 0 type II, n = 2 type III, n = 4 type IV, n = 1 type V, n =7 type VI). Nonoperative treatment occurred in 63.3% (n = 19). Operative intervention rate was 33% (n = 10). All patients who underwent an operation were symptomatic with abdominal pain on presentation (P < .01) (Table I). Two patients presented with rupture and five presented with signs of acute mesenteric ischemia necessitating emergent exploration. Two patients required bowel resection for necrosis. Sakamoto classification was also significantly associated with operative intervention (P < .01). Patients presenting with abdominal pain were three times as likely to undergo operative treatment (odds ratio, 3.13; P < .01) (Table II), while patients with a modified Sakamoto classification type V and above were 10 times more likely to undergo an operative intervention (odds ratio, 10.5; P < .02) (Table II). A large majority of operative cases (n = 9; 90%) were diagnosed with involvement of SMA dissection. Unplanned secondary intervention rate was 30% (n = 3). There was 9.5% mortality rate amongst those with SMA vessel involvement (10% overall mortality). Among those patients that followed-up, all were asymptomatic at the time of follow-up (n = 16). Patients with nonoperative interventions had 57% favorable remodeling (n = 4). Symptomatic patient presentation and higher modified Sakamoto classification type (types V and VI) tend to require operative intervention. Although a majority of spontaneous isolated mesenteric dissections may be treated nonoperatively with either medical therapy or observation alone, identifying patient characteristics amongst those that require operative intervention are important considerations for management of this rare disease process.Table IClinical characteristics by operative interventionOverall, n = 30Operative repair, n = 10Nonoperative, n = 20P valueaAge61.00 ± 12.0854.30 ± 13.4164.35 ± 10.11.031Gender.6 Female4 (13)2 (20)2 (10) Male26 (87)8 (80)18 (90)Ethnicity/Race.032 Asian18 (60)5 (50)13 (65) Hispanic5 (17)2 (20)3 (15) Other3 (10)3 (30)0 (0) White4 (13)0 (0)4 (20)Smoking history.7 Yes10 (33)4 (40)6 (30) No20 (67)6 (60)14 (70)Atrial fibrillation.7 Yes7 (23)3 (30)4 (20) No23 (77)7 (70)16 (80)Hypertension.4 Yes10 (33)2 (20)8 (40) No20 (67)8 (80)12 (60)White blood cells.4 >1211 (37)5 (50)6 (30) 4-1219 (63)5 (50)14 (70)Systolic blood pressure groups>.9 High (>140)17 (57)6 (60)11 (55) Normal (100-140)11 (37)3 (30)8 (40) Low (<100)2 (6.7)1 (10)1 (5.0)Modified Sakamoto class (types I-VI).008 Type I5 (24)1 (11)4 (33) Type II0 (0)0 (0)0 (0) Type III2 (9.5)1 (11)1 (8.3) Type IV4 (19)0 (0)4 (33) Type V2 (9.5)0 (0)2 (17) Type VI8 (38)7 (78)1 (8.3)Symptomatic at presentation.011 Yes20 (67)10 (100)10 (50) No10 (33)0 (0)10 (50)Length of stay7.67 ± 8.5614.00 ± 10.424.50 ± 5.35.004Intensive care unit length of stay2.57 ± 4.766.50 ± 6.430.60 ± 1.67<.001Deceased.3 Yes3 (10)2 (20)1 (5) No27 (90)8 (80)19 (95)Values are mean ± SD or number (%).aWilcoxon rank-sum test; Fisher's exact test. Open table in a new tab Table IIOdds ratio analysis of symptomatic presentation and Sakamoto classification with operative interventionOR95% CIP valueSymptomatic at presentation3.131.08-406.55.011Sakamoto class type V-VI10.51.57-105.00.024CI, Confidence interval; OR, odds ratio. Open table in a new tab

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

We compared the early and mid-term (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). 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. A total of 121 patients were included in the study (23 with conservative treatment, 42 with BST, 56 with BSACT). Symptoms were relieved in 91.3% of conservative patients, whereas all patients (100%) with BST or BSACT had symptom relief, p= .035. There was no significant difference in the length of hospital stay between the two endovascular treatments (EVT) (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 vs. 46.3% for BST (p < .0001) vs. 42.9% for conservative patients (p < .0001). There were no significant differences between the last two groups (p = .3925). The prevalence of adverse events for abdominal pain recurrence and aneurysm formation was also significantly lower in the BSACT group at follow-up. BSACT for SISMAD has a preferable early outcome. The cumulative complete remodeling rate and the event-free survival rate are satisfactory at mid-term follow-up. BSACT is an effective approach for SISMAD.

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.

Conservative Versus Endovascular Treatment for Spontaneous Isolated Superior Mesenteric Artery Dissection: A Clinical and Imaging Follow-up Study.

Spontaneous isolated superior mesenteric artery dissection (SISMAD) is a rare vascular disease, the treatment strategies for which remain debated. This retrospective study aimed to compare the outcomes of conservative and endovascular treatments in patients with SISMAD. Fifty-eight patients with SISMAD confirmed by computed tomography angiography admitted to our hospital between November 2017 and May 2021 and received confirmed conservative (n=43) or endovascular (n=15) treatment. The patient demographics, imaging analysis, and follow-up results were analyzed and compared. The cohort included 54 males and 4 females with a mean age of 52 years. Abdominal pain was the major complaint (49/58, 84.5%), followed by chest pain (2/58, 3.4%). The mean follow-up was 9.1±7.9 months. The 2 main Sakamoto types were type III (27/58, 46.6%) and type IV (16/58, 27.6%). Most patients in both groups had angle 1 (aortomesenteric angle) and angle 2 (superior mesenteric artery [SMA] course) of over 80°. About 67.3% of patients had long length of dissection (>60 mm). The median distance between the SMA root and the dissection entry site was 1.5 cm, mostly (84.5% of the patients) in the curved segment of the SMA. Telephone follow-ups found that most patients survived pain-free, and none underwent intestinal resection. Only 4 patients, 2 in each group, had recurrent abdominal pain during follow-up and received stenting treatment to achieve complete vascular remodeling. Importantly, we found that the conservative and endovascular therapies achieved similar high remodeling rates (94% and 100%, respectively; p=0.335). The conservative group achieved satisfying vascular remodeling (partial, 35%; complete, 59%), making it as safe and effective a treatment as endovascular therapy. Initial conservative management is safe and effective in patients with SISMAD. A high technical success rate and favorable short-term outcomes were associated with endovascular procedures as secondary interventions. It would be helpful to conduct large-scale, prospective, randomized controlled trials with long-term follow-up for SISMAD. 1. This research provided more detail clinical information, such as evaluation of abdominal pain and measurements of SMA angles, which is all relevant to treatment. 2. What's more, the most surprising results of follow-up part shown that conservative treatment could reached the remodeling rate as high as endovascular treatment, which was relatively low in other studies. It helps us share our treatment experience with clinicians. 3. In addition, we get limited knowledge about this rare disease, it's encouraging us to do more researches based on the results we had.

Features of Surgical Treatment of Symptomatic Patients with Isolated Superior Mesenteric Artery Dissection (Clinical Cases and Literature Review)

Introduction. Isolated superior mesenteric artery dissection (ISMAD) is a rare disease with high variability of clinical manifestations: from incidental findings to the development of acute or chronic mesenteric ischemia and the formation of aneurysms with the probability of their rupture. Despite significant world experience, surgical and conservative treatment of patients with ISMAD remains debatable.&#x0D; The aim. Improvement of the diagnosis and surgical treatment of patients with ISMAD.&#x0D; Clinical cases.&#x0D; In the first clinical observation, a 78-year-old patient with chronic visceral ischemia was diagnosed with an aneurysm of the upper mesenteric artery with signs of dissection and malperfusion. Previous unsuccessful attempts of endovascular treatment at another hospital caused the need for open surgical intervention – resection of the aneurysm and upper mesenteric artery reconstruction.&#x0D;  &#x0D; In the second clinical case, a 61-year-old patient had acute abdominal pain syndrome, and based on clinical examination, laboratory and instrumental examination, the diagnosis of acute mesenteric ischemia with signs of dissection of the superior mesenteric artery was confirmed, which determined immediate indications for surgical treatment – resection of the affected segment of superior mesenteric artery and aorta-superior mesenteric bypass.&#x0D;  &#x0D; The surgical interventions contributed to complete regression of clinical symptoms. Follow-up of the patients showed promising long-term results.&#x0D;  &#x0D; Conclusion. Computed tomography angiography is the method of choice in the diagnosis of ISMAD and makes it possible to provide prompt diagnosis, determine treatment tactics and prevent the development of fatal complications. Open surgical intervention in some cases remains the method of choice in the treatment of ISMAD.

Comparative analysis of prevalence, evaluation, management, and rehabilitation outcome of spontaneous isolated visceral artery dissection: a systematic review and meta-analysis of 80 reports.

Because of relatively little data for management and evaluation surrounding spontaneous isolated visceral artery dissection (IVAD), existing studies have failed to provide comprehensive analysis for the management, evaluation, prevalence, as well as natural course of the disease. Therefore, we collected and analyzed current evidence on spontaneous IVAD with the aim of providing quantitative pooled data for the natural course and treatment standardization of the disease. A systematic search of PubMed, Embase, the Cochrane Library, and Web of Science up to 1 June 2022, was conducted for relevant studies that investigating the natural course, treatment, classification, and outcomes of IVAD. The primary outcomes were to determine the difference in prevalence, risk factors, and characteristics between different spontaneous IVAD. Two reviewers assessed the trial quality and extracted the data independently. All statistical analyses were performed using the standard statistical procedures provided in Review Manager 5.2 and Stata 12.0. A total of 80 reports with 1040 patients were identified. The pooled results indicated that in IVAD, isolated superior mesenteric artery dissection (ISMAD) was more prevalent, with a pooled prevalence of 60% (95% CI: 50-71%), followed by isolated celiac artery dissection (ICAD) (prevalence: 37%; 95% CI: 27-46%). IVAD was male predominated with a pooled proportion of 80% (95% CI: 72-89%). Similar results were found in ICAD (prevalence: 73%; 95% CI: 52-93%). More IVAD patients were diagnosed with symptoms than ICAD (64 vs. 59%). Regarding to the risk factors, this pooled analysis found smoking and hypertension were the top two conditions in both spontaneous IVAD and ICAD patients, with proportion of 43, 41, 44, and 32%, respectively. It was observed that ICAD appeared shorter dissection length (mean difference: -3.4cm; 95% CI: -4.9 to -2.0; P <0.0001), higher prevalence of Sakamoto's classification Π (odds ratio: 5.31; 95% CI: 1.77-15.95; P= 0.003) and late progression (odds ratio: 2.84; 95% CI: 1.02-7.87; P= 0.05) than ISAMD. Spontaneous IVAD was male predominant and ISMAD was most prevalent followed by ICAD. Smoking and hypertension were the top two conditions in both spontaneous IVAD and ICAD patients. The majority of patients diagnosed with IVAD received observation and conservative treatment and experienced a low proportion of reintervention or progression, especially for ICAD patients. In addition, ICAD and ISMAD had several differences in clinical features and dissection characteristics. Future studies with enough sample size and long follow-up are required to clear the management, long-term outcome, and risk factors of the IVAD prognosis.

Isolated Superior Mesenteric Artery Dissection

Isolated Superior Mesenteric Artery Dissection

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

To present 5-year results of management on spontaneous isolated superior mesenteric artery dissection (SISMAD) from 2 teaching hospitals in China. The clinical data of 41 patients with SISMAD were retrospectively collected from 2 teaching hospitals between December 2016 and December 2021. Therapeutic methods mainly included open surgery, endovascular management, and conservative therapy. Patients' demographics, total number of WBC (White blood cell, WBC), the percentage of NEUT (Neutrophil), the level of CRP (C-reactive protein, CRP), duration of abdominal pain on admission, YOO classification of SISMAD, angle of superior mesenteric artery to abdominal aorta (ASA), length of hospital stays, and vascular remodeling rate of SMA between endovascular and conservative groups were analyzed. A total of 41 patients with SISMAD were finally included in this study. Their average age was 53.4±7.1years old, ranging from 35 to 68years old. Among these patients, 1 patient suffered emergent open surgery because of the intestinal necrosis. The other 40 patients were treated conservatively at first, but 13 of them were transitioned into endovascular management due to persistent abdominal pain. Regarding the imaging analysis, IIS and IVS types of YOO classification were more in the endovascular group (13 patients) than the conservative group (27 patients). The length of hospital stays (P=0.003) and the vascular remodeling rate of SMA were significantly different between 2 groups (P=0.002), while the time of abdominal pain on admission, the infection markers (WBC, CRP, NEUT) and ASA were not significantly different between the 2 groups. In SISMAD, patients without any signs of peritonitis and intestinal necrosis may be treated conservatively firstly, and then transitioned into endovascular management if abdominal pain is not improved within 48hr. IIS and IVS types of YOO classification should be alerted of this potential transition. But the optimal timing of transition required more clinical studies.

[Advances in the classification and treatment of isolated superior mesenteric artery dissection].

Isolated superior mesenteric artery dissection (ISMAD) has attracted more and more clinicians' attention in recent years. Patients onset of ISMAD often present with abdominal pain. The misdiagnosis or miss diagnosis is common because of the non-specific symptoms and signs, which even can endanger lives in serious cases. Imaging classification is of great significance for diagnosis and treatment of ISMAD. The Sakamoto classification and the Yun classification are two classical classified methods. However, with the further study of ISMAD, various new classifications emerge. Conservative treatment was once considered as the preferred. As the rapid development of endovascular therapy and the great progress of new devices, stenting therapy can significantly improve symptoms and achieve satisfactory long-term effects, and be even expected to become the preferred method for clinical therapy of ISMAD. However, the long-term effects of endovascular therapy still need a large number of follow-up data, and complications after stent implantation can't be ignored.

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.

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. 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. 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. 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. 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.

A Case of Spontaneous Isolated Superior Mesenteric Artery Dissection in a Patient With Celiacomesenteric Trunk Anomaly

Celiacomesentric trunk (CMT) is a rare vascular anomaly with a common origin for the celiac artery and superior mesenteric artery. To our knowledge, this is the first case of superior mesenteric artery (SMA) dissection in patients with CMT. Here, we discuss a case of a 65-year-old male with acute-onset epigastric pain who was found to have SMA dissection with CMT. He was treated conservatively with symptomatic improvement. Diagnostic imaging studies include computed tomography (CT) scanning of the abdomen with or without contrast and CT angiography. Management options include a conservative approach, endovascular repair, and surgical management based on the classification/location of the dissection.

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

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. 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. All patients experienced acute abdominal pain prior to admission, with an onset time of 29.95 ± 24.66hours. The mean time until relief of abdominal pain in patients who received conservative treatment was 42.17 ± 38.09hours. 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. 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.

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

To investigate the diameter changes of Riolan's arch in patients with isolated superior mesenteric artery dissection (ISMAD) and to evaluate the implication for treatment selection. Ninety-five patients with CT angiography (CTA) confirmed ISMAD were retrospectively included, and another 95 cases with no positive findings on abdominal CTA were included as controls. According to the treatment methods, the patients were subsequently divided into conservative treatment (n = 68) or invasive treatment (n = 27) subgroups. According to the initial CTA images, the prevalence of Riolan's arch as well as its diameter (DR) were determined in each subject, and compared between ISMAD and control cases, as well as between patients with different treatments. In patients with ISMAD, dissections were classified according to the Li classification. Riolan's arch prevalence and DR were significantly elevated in the ISMAD group compared with the control group (83.16% vs. 35.79%, P < 0.001; 2.63 ± 0.56mm vs. 2.12 ± 0.39mm, P < 0.001). Patients with invasive treatment had significantly higher baseline DR (2.93 ± 0.57mm vs. 1.89 ± 1.14mm, P < 0.001), and higher proportion of high-risk dissection (P < 0.001) than those administered conservative treatment. Binary logistic regression revealed DR (OR = 2.771, 95% CI 1.157-6.638, P = 0.022) and Li classification (OR = 0.107, 95% CI 0.019-0.586, P = 0.010) were independent risk factors for treatment selection. With cutoff of 2.635mm, the area under the curve, sensitivity, and specificity were 0.805, 0.778 and 0.794, respectively. Dilation of Riolan's arch is common in patients with ISMAD, and Riolan's arch diameter could be a convenient indicator of disease severity and inform subsequent treatment.

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

ObjectiveTo 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.MethodsEighty-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.ResultsZerbib 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.ConclusionAfter 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.

A Case of Isolated Superior Mesenteric Artery Dissection with Prolonged Ischemic Enteritis Requiring Reoperation

A Case of Isolated Superior Mesenteric Artery Dissection with Prolonged Ischemic Enteritis Requiring Reoperation