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.

Predictors of Survival Without Intestinal Resection after First-Line Endovascular Revascularization in Patients with Acute Arterial Mesenteric Ischemia.

Background Acute arterial mesenteric ischemia requires emergency treatment and is associated with high mortality rate and poor quality of life. Identifying factors associated with survival without intestinal resection (hereafter, intestinal resection-free [IRF] survival) could help in treatment decision-making after first-line endovascular revascularization. Purpose To identify factors associated with 30-day IRF survival in patients with acute arterial mesenteric ischemia whose first-line treatment was endovascular revascularization. Materials and Methods Patients with acute arterial mesenteric ischemia whose first-line treatment was endovascular revascularization because of a low probability of bowel necrosis were included in this single-center retrospective cohort (May 2014 to August 2022). Patient demographics, laboratory values, clinical characteristics at admission, CT scans, angiograms, and endovascular revascularization-related variables were included. The primary end point was 30-day IRF survival, and secondary end points were 3-month, 1-year, and 3-year overall survival. Factors independently associated with 30-day IRF survival were identified with binary logistic regression. Results A total of 117 patients (median age, 70 years [IQR, 60-77]; 53 female, 64 male) were included. Within 30 days after revascularization, 73 of 117 patients (62%) survived without resection, 28 of 117 (24%) survived after resection, 14 of 117 (12%) died without resection, and two of 117 (2%) underwent resection but died. The 30-day IRF survival was 63% (74 of 117). The 3-month, 1-year, and 3-year mortality rate was 18% (21 of 117), 21% (25 of 117), and 27% (32 of 117), respectively. Independent predictors of 30-day IRF survival were persistent bowel enhancement at initial CT (odds ratio [OR], 0.3; 95% CI: 0.2, 0.8; P = .013) and C-reactive protein (CRP) level less than 100 mg/L (OR, 0.3; 95% CI: 0.1, 0.8; P = .002). The 30-day IRF survival was 86%, 61%, 47%, and 23% in patients with both favorable features, persistent bowel enhancement but CRP level greater than 100 mg/L, no bowel enhancement but CRP level less than 100 mg/L, and both unfavorable features, respectively. Conclusion Independent predictors associated with 30-day IRF survival in patients with acute arterial mesenteric ischemia whose first-line treatment was endovascular revascularization were persistent bowel wall enhancement at initial CT and CRP level less than 100 mg/L. © RSNA, 2024 Supplemental material is available for this article.

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.

Impact of Culture-Positive Preservation Fluid on Early Morbidity and Mortality After Lung Transplantation.

The prevalence, risk factors and outcomes associated with culture-positive preservation fluid (PF) after lung transplantation (LT) are unknown. From January 2015 to December 2020, the microbiologic analyses of PF used to store the cold ischaemia-placed lung graft(s) of 271 lung transplant patients were retrospectively studied. Culture-positive PF was defined as the growth of any microorganism. Eighty-three (30.6%) patients were transplanted with lung grafts stored in a culture-positive PF. One-third of culture-positive PF were polymicrobial. Staphylococcus aureus and Escherichia coli were the most frequently isolated microorganisms. No risk factors for culture-positive PF based on donor characteristics were identified. Forty (40/83; 48.2%) patients had postoperative pneumonia on Day 0 and 2 (2/83; 2.4%) patients had pleural empyema with at least one identical bacteria isolated in culture-positive PF. The 30-day survival rate was lower for patients with culture-positive PF compared with patients with culture-negative PF (85.5% vs. 94.7%, p = 0.01). Culture-positive PF has a high prevalence and may decrease lung transplant recipient survival. Further studies are required to confirm these results and improve understanding of the pathogenesis of culture-positive PF and their management.

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.

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.

Reperfusion injury on computed tomography following endovascular revascularization of acute mesenteric ischemia: prevalence, risk factors, and patient outcome.

BACKGROUND: Data about reperfusion injury (RI) following acute arterial mesenteric ischemia (AAMI) in humans are scarce. We aimed to assess the prevalence and risk factors of RI following endovascular revascularization of AMI and evaluate its impact on patient outcomes. METHODS: Patients with AAMI who underwent endovascular revascularization (2016-2021) were included in this retrospective cohort. CT performed < 7 days after treatment was reviewed to identify features of RI (bowel wall hypoattenuation, mucosal hyperenhancement). Clinical, laboratory, imaging, and treatments were compared between RI and non-RI patients to identify factors associated with RI. Resection rate and survival were also compared. RESULTS: Fifty patients (23 men, median 72-yrs [IQR 60-77]) were included, and 22 were diagnosed with RI (44%) after a median 28 h (22-48). Bowel wall hypoattenuation and mucosal hyperenhancement were found in 95% and 91% of patients with post-interventional RI, respectively. Patients with RI had a greater increase of CRP levels after endovascular treatment (p = 0.01). On multivariate analysis, a decreased bowel wall enhancement on baseline CT (HR = 8.2), an embolic cause (HR = 7.4), complete SMA occlusion (HR = 7.0), and higher serum lactate levels (HR = 1.4) were associated with RI. The three-month survival rate was 78%, with no difference between subgroups (p = 0.99). However, the resection rate was higher in patients with RI (32% versus 7%; p = 0.03). CONCLUSION: RI is frequent after endovascular revascularization of AAMI, especially in patients who present with decreased bowel wall enhancement on pre-treatment CT, an embolic cause, and a complete occlusion of the SMA. However, its occurrence does not seem to negatively impact short-term survival.

Aortic thrombosis as a dramatic vascular complication in COVID-19 disease.

OBJECTIVE: To report clinical outcomes of COVID-19 related acute aortic thrombosis (AAT). METHODS: Consecutive COVID-19 patients presenting with AAT between April 2020 and August 2021 were included retrospectively. Clinical and radiological data were prospectively collected. RESULTS: Ten patients (men, 90%; mean age, 64 ± 2 years) were included. At the time of AAT diagnosis, four patients were in intensive care unit. Median time between diagnosis of COVID-19 and AAT was 5 days [IQR 0-8.5]. Clinical presentation was acute lower limb ischaemia (n=9) and mesenteric ischaemia (n=2). Thrombus localization was the abdominal aorta (n=5), the thoracic aorta (n=2) or both (n=3), with the following embolic sites: lower limbs (n=9), renal arteries (n=3), superior mesenteric artery (n=2), splenic artery (n=1), cerebral arteries (n=1). Revascularization was performed in 9 patients, using open (n=6), endovascular (n=2) or hybrid techniques (n=1). Three patients required reinterventions. The 30-day mortality was 30%. Three major amputations were performed in two patients, resulting in a free-amputation survival rate of 50% after a median follow-up of 3,5 months [IQR 2-4.1]. CONCLUSION: AAT is a rare and devastating complication of COVID-19 disease, responsible for high mortality and amputation rates.

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.