Impact of the Endonaut® angio-navigation system on radiation exposure in endovascular aortic repair performed with mobile C-arms.

OBJECTIVE: Fusion imaging systems have proved to reduce radiation exposure mostly in hybrid rooms but reports with mobile C-arms are few. The aim of this study was to analyse the impact of the Endonaut® navigation system on radiation exposure in endovascular aneurysm repair (EVAR) performed with mobile C-arms. METHODS: All patients undergoing EVAR and/or iliac branched devices implantation between January 2016 and August 2022 were included. All procedures were performed with a mobile C-arm (Siemens Avantic® or GE Elite® until March 2018, Siemens Cios Alpha® thereafter). The Endonaut® navigation system has been used since January 2021. Two groups were therefore compared : before (control group) and after the use of Endonaut®. Radiation data including Dose Area Product (DAP) values, Air Kerma (AK) and fluoroscopy time (FT) were collected retrospectively. RESULTS: Overall, 153 patients were included: control group (CGr), n = 121; Endonaut® group (EnGr), n = 32. No significant difference was found between the two groups regarding demographic data. DAP values were significantly lower in the EnGr (38 Gy.cm2 ± 24) vs. the CGr (76 Gy.cm2 ± 51) (p<.05) despite a significantly higher number of complex procedures such as iliac branched devices (p<.05). AK values were not significantly different between the EnGr and the CGr (196 mGy ± 114 vs. 209 mGy ± 138) as well as FT (33 minutes ± 18 vs. 33 minutes ± 16). Technical success was 97% (31/32) in the EnGr vs. 96% (116/121) in the CGr (p=.79). The volume of contrast media was significantly lower in the EnGr (94 cc ± 41) vs. the CGr (143 cc ± 66) (p<.05). CONCLUSION: In this study, the use of the Endonaut® angio-navigation system when performing EVAR with mobile C-arms led to a radiation dose reduction without compromising technical success or procedural time.

Treatment of Aortoiliac Occlusive Lesions by Aortic Robotic Surgery: Learning Curve and Midterm Outcome.

BACKGROUD: The learning curve and midterm results of aortoiliac occlusive disease (AIOD) revascularization by robot-assisted laparoscopic (RAL) surgery may be known. METHODS: A prospective single-center study was conducted in the vascular surgery department of Georges Pompidou European Hospital (Paris, France). Patients with AIOD treated by RAL from February 2014 to February 2019 were included. Demographic characteristics, past medical history, Trans-Atlantic Inter-Society Consensus (TASC) lesions classifications, mortality, primary and secondary patency, as well as complication rates were collected. Safety was analyzed by the cumulative sum control chart method with a conversion rate of 10%, operative time by cumulative average-time model, and primary and secondary patency by the Kaplan-Meier method. RESULTS: Seventy patients were included, 18 (25.7%) with TASC C lesions and 52 (74.3%) with TASC D lesions. Before discharge, 14 (24.3%) patients had surgical complications. Among them, 10 (14.3%) required at least one reintervention. One (1.4%) patient died during the hospitalization. The learning curve in terms of safety (conversion rate) was 13 cases with an operating time of 220 minutes after 35 patients. During follow-up (median 37 months [21; 49]), 63 patients (91.3%) improved their symptoms, 53 (76.8%) became asymptomatic, and 3 graft limb occlusions occurred. The primary patency at 12, 24, 36, and 48 months was 94%, 92%, 92%, and 92%, respectively, while the secondary patency for the same intervals was 100%, 98.1%, 98.1%, and 98.1%, respectively. CONCLUSIONS: Robotic surgery in AIOD revascularization seems safe and effective; allowing to treat patients with few comorbidities and severe lesions, in a dedicated center experienced in RAL, with excellent patency. Prospective clinical trials should be performed to confirm safety.

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.

Improving clinical suspicion of acute mesenteric ischemia among patients with acute abdomen: a cross-sectional study from an intestinal stroke center.

BACKGROUND: Early diagnosis of acute mesenteric ischemia (AMI) is essential for a favorable outcome. Selection of patients requiring a dedicated multiphasic computed tomography (CT) scan remains a clinical challenge. METHODS: In this cross-sectional diagnostic study conducted from 2016 to 2018, we compared the presentation of AMI patients admitted to an intestinal stroke center to patients with acute abdominal pain of another origin admitted to the emergency room (controls). RESULTS: We included 137 patients-52 with AMI and 85 controls. Patients with AMI [median age: 65 years (interquartile range 55-74)] had arterial and venous AMI in 65% and 35% of cases, respectively. Relative to controls, AMI patients were significantly older, more likely to have risk factors or a history of cardiovascular disease, and more likely to present with sudden-onset and morphine-requiring abdominal pain, hematochezia, guarding, organ dysfunction, higher white blood cell and neutrophil counts, and higher plasma C-reactive protein (CRP) and procalcitonin concentrations. On multivariate analysis, two independent factors were associated with the diagnosis of AMI: the sudden-onset (OR = 20, 95%CI 7-60, p < 0.001) and the morphine-requiring nature of the acute abdominal pain (OR = 6, 95%CI 2-16, p = 0.002). Sudden-onset and/or morphine-requiring abdominal pain was present in 88% of AMI patients versus 28% in controls (p < 0.001). The area under the receiver operating characteristic curve for the diagnosis of AMI was 0.84 (95%CI 0.77-0.91), depending on the number of factors. CONCLUSIONS: Sudden onset and the need for morphine are suggestive of AMI in patients with acute abdominal pain and should prompt multiphasic CT scan including arterial and venous phase images for confirmation.

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.

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.

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.

Retrograde Open Mesenteric Stenting for Acute and Chronic Mesenteric Ischaemia: Results from an Intestinal Stroke Centre.

OBJECTIVE: To report the intra-operative adverse events (IOAEs) and the initial and one year outcomes of retrograde open mesenteric stenting (ROMS) using balloon expandable covered stents for acute and chronic mesenteric ischaemia. METHODS: Clinical data and outcomes of all consecutive patients treated with ROMS for acute and chronic mesenteric ischaemia at an intestinal stroke centre between November 2012 and September 2019 were reviewed. ROMS was performed using balloon expandable covered stents. Endpoints included IOAEs, in hospital mortality, post-operative complications, and re-interventions. One year overall survival, freedom from re-intervention, primary patency and assisted primary patency rates were analysed using the Kaplan-Meier time to event method. RESULTS: During the study period, 379 patients were referred to the centre for acute or chronic mesenteric ischaemia. Thirty-seven patients who underwent the ROMS procedure were included. All the patients had severe atherosclerotic mesenteric lesions. The ROMS technical success rate was 89% in this cohort. The rate of IOAEs was 19% and included four cases of retrograde recanalisation failure. All ROMS failures occurred in patients presenting with flush superior mesenteric artery occlusion and they were treated by mesenteric bypass. Ten patients (27%) underwent bowel resection, four of which resulted in a short bowel syndrome (11%). The in hospital mortality rate was 27%. Post-operative complications and re-intervention rates were 67% (n = 25) and 32% (n = 12), respectively. The median follow up was 20.2 months (interquartile range 29). The estimated one year overall survival for the cohort was 70.1% (95% confidence interval [CI] 52.5% - 82.2%). The estimated freedom from re-intervention at one year was 61.1% (95% CI 42.3 - 75.4). The one year primary patency and assisted primary patency rates were 84.54% (95% CI 63.34 - 94) and 92.4% (95% CI 72.8 - 98), respectively. CONCLUSION: ROMS procedures offer acceptable one year outcomes for mesenteric ischaemia but are associated with frequent stent related complications. Precise pre-operative planning, high quality imaging, and meticulous stent placement techniques may limit the occurrence of such events.

Midterm results after covered stenting of the superior mesenteric artery.

OBJECTIVE: Despite the continuing controversy of covered stents (CS) vs bare metal stents, the use of CS in mesenteric occlusive disease (MOD) has been recommended by expert centers. The aim of this study was to report midterm results with CS of the superior mesenteric artery. METHODS: Between January 2014 and October 2019, patients with MOD with a severe atheromatous stenosis or occlusion of the superior mesenteric artery treated by mesenteric CS were included. Clinical presentation included both acute mesenteric ischemia (AMI), chronic mesenteric ischemia, and asymptomatic patients planned for major surgery. Demographics, procedure details, and follow-up data were prospectively collected and retrospectively reviewed. Study end points included primary patency, primary assisted patency, and secondary patency. RESULTS: During the study period, 86 patients (mean age, 70 ± 9 years; 57% males) were included. Clinical presentation was AMI (n = 42 [49%]), chronic mesenteric ischemia (n = 31 [36%]), and asymptomatic (n = 13 [15%]). The technical success rate was 97%. A total of 96 stents were implanted, including 86 proximal CS (Advanta V12, n = 73; Lifestream, n = 13). The mean length and mean diameter of the CS were 31.5 ± 6.3 mm and 6.9 ± 0.5 mm, respectively. Additional distal bare metal stents were used in 10 patients (12%) to overcome a kinking (n = 9) or a dissection (n = 1) downstream of the CS. All postoperative deaths occurred in patients with AMI (n = 11, 13%). During a median follow-up of 15.6 months (95% confidence interval [CI], 15.6 ± 3.6 months), 12 patients (14%) underwent reinterventions for either stent misplacement (n = 3), stent recoil (n = 3), stent thrombosis (n = 2), de novo stenosis at the distal edge of the CS (n = 2), or gastric ischemia (n = 1). At 1 year, overall the primary patency, primary assisted patency, and secondary patency rates were 83% (95% CI, 83% ± 9%), 99% (95% CI, 99% ± 3%), and 99% (95% CI, 99% ± 3%), respectively. At 2 years, the overall primary patency, primary assisted patency, and secondary patency rates were 76% (95% CI, 76% ± 13%), 95% (95% CI, 95% ± 8%) and 95% (95% CI, 95% ± 8%), respectively. CONCLUSIONS: Mesenteric CS provide very satisfactory midterm results in patients with MOD, with an excellent primary assisted patency rate at 2 years, at the price of a significant reintervention rate.

[Management of abdominal aortic aneurysms]. / Prise en charge des anévrysmes de l'aorte abdominale.

MANAGEMENT OF ABDOMINAL AORTIC ANEURYSMS The abdominal aortic aneurysm is a permanent dilation of the aorta with a diameter of more than 30 mm. It can be strictly infra-renal or be located opposite the origin of the digestive and renal arteries (complex aneurysm). Most often fortuitous, the diagnosis must seek a secondary location of the aneurysmal disease (thoracic aorta, popliteal artery) as well as other manifestations of atheromatous disease. The natural course of the aneurysm is rupture, the severity of which is such that preventive and elective surgical treatment is warranted when the aneurysm reaches 55 mm or if it grows rapidly. Regular monitoring of the diameter by Doppler ultrasound is necessary when the diameter is less than 45 mm; beyond this threshold, a CT angiogram and a specialist consultation in vascular surgery are necessary. Flattening - graft and stent exclusion are the two possible surgical options; the anatomy of the aneurysm and the patient's comorbidities determine the choice of surgical technique.

PRISE EN CHARGE DES ANÉVRYSMES DE L'AORTE ADBOMINALE L'anévrysme de l'aorte abdominale est une dilatation permanente de l'aorte dont le diamètre est supérieur à 30 mm. Il peut être strictement sous-rénal ou être situé en regard de l'origine des artères digestives et rénales (anévrysme complexe). Le plus souvent fortuit, le diagnostic doit faire rechercher une localisation secondaire de la maladie anévrysmale (aorte thoracique, artère poplité) ainsi que les autres manifestations de la maladie athéromateuse. L'évolution naturelle de l'anévrysme est la rupture, dont la gravité est telle qu'un traitement chirurgical préventif et électif est justifié lorsque l'anévrysme atteint 55 mm ou en cas de croissance rapide. Une surveillance régulière du diamètre par écho-Doppler est nécessaire lorsque celui-ci est inférieur à 45 mm ; au-delà de ce seuil, un angioscanner et une consultation spécialisée en chirurgie vasculaire sont nécessaires. La mise à plat-greffe et l'exclusion par endoprothèse sont les deux options chirurgicales possibles ; l'anatomie de l'anévrysme et les comorbidités du patient déterminent le choix de la technique opératoire.