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

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.

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

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

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.

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.

Worsening Isolated Superior Mesenteric Artery Dissection on the Day After Discharge

A 59-year-old male was transported to the emergency department by ambulance with complaints of left-sided abdominal pain. Blood gas analysis revealed elevated lactate, and plain computed tomography revealed no bowel ischemic change. Contrast-enhanced computed tomography revealed isolated superior mesenteric artery dissection with mildly stenosed true lumen. The patient was treated with conservative management on admission. Staged fluid intake, oral prescriptions, and diet were commenced with attention to the symptoms. After four days of hospitalization, the patient was discharged with a stable condition. However, the patient returned to our hospital complaining of left lower back pain three hours after discharge. Contrast-enhanced computed tomography revealed an enlarged false lumen with a moderately stenosed true lumen. After a thorough discussion between vascular surgeons and interventional radiologists, conservative management was commenced on the second admission. The clinical course was uneventful, with proof of improved imaging findings.

Volumetric Analysis of Progressive Remodeling of Isolated Mesenteric Artery Dissection Treated by Conservative Therapy

PURPOSE

To characterize remodeling of conservatively treated isolated mesenteric artery dissection (IMAD) using 3-dimensional (3D) volumetric analysis.

MATERIAL AND METHODS

Patients with Type I/II (classification of Yun) treated by conservative therapy between January 2018 and January 2020 were prospectively included. Semiautomatic morphological analysis of the superior mesenteric artery (SMA) included volumetric measurements of the true lumen (TL), false lumen (FL), and overall lumen (OL) and 3D aortomesenteric angles from computed tomography angiography data at admission (T0), 1 month (T1), and 12 months (T12). The SMA morphology of patients with IMAD (n = 15, mean age 53 years ± 7; 87% men) was also compared with that of control individuals (n = 51, mean age 56 years ± 4; 94% men).

RESULTS

A significant reduction in OL volume was observed (P <.001), whereas TL volume remained stable (P =.23). The TL/OL volume ratio significantly increased over time (P =.001) from 53% at T1 to 78% at T12. Aortomesenteric 3D angles at 2, 4, and 6 cm from the ostium showed a progressive decrease toward values observed in the control group (P =.013, P =.002, and P =.027, respectively). At T12, 5 patients (33%) had complete remodeling, and aneurysmal change was observed in 2 patients (<20 mm). Smoking and SMA angle at a distance of 6 cm from the ostium (T0) were the only factors affecting remodeling negatively at T12.

CONCLUSIONS

One-year remodeling in IMAD followed an overall decrease in OL volume related to a decrease in FL volume. Smokers and patients with larger SMA angles at baseline showed poorer remodeling. Spontaneous arterial remodeling in IMAD might favor conservative therapy.