Inverted Ovation iX Limb to Treat an Isolated Common Iliac Artery Aneurysm.

In recent years, endovascular aneurysm repair has become the predominant method of managing abdominal aortic and common iliac artery aneurysms. Off-label use of different endovascular devices has allowed them to remain a viable option in many cases of atypical anatomy. Some studies have reported the use of iliac devices in an upside-down configuration when the common iliac artery aneurysm has a reverse-tapered morphology. However, the use of the Ovation iX (Endologix) limb in an upside-down configuration has not yet been reported. This limb offers a 14 mm distal end when inverted and offers good patency in the tortuous iliac morphology. This case report describes and illustrates the precise deployment of an inverted Ovation iX limb to treat an isolated common iliac artery aneurysm.

A mycotic aneurysm of a jejunal branch treated by aneurysmectomy without bowel resection.

Jejunal artery pseudoaneurysms are extremely rare, accounting for <1% of all visceral artery pseudoaneurysms. Fewer than 50 cases were reported in literature during the previous century. This case report describes the case of a 72-year-old man who underwent aneurysmectomy to treat a 21-mm mycotic jejunal artery pseudoaneurysm found in the setting of endocarditis. This pseudoaneurysm was treated with laparotomy, and gentle dissection of the tissues surrounding the pseudoaneurysm was performed before ligation and resection. This allowed for vascular collateral branch preservation, which, thus, avoided concomitant bowel resection. This report highlights the feasibility of this technique.

Treating a Large Thoracoabdominal Aneurysm With Aberrant Right Subclavian Artery With a Physician-Modified Graft.

CLINICAL IMPACT: Large thoracoabdominal aortic aneurysms due to chronic aortic dissection in patients with connective tissue disorders such as Loeys-Dietz syndrome present a challenging scenario, particularly in cases of variant anatomy and when patients are not candidates for conventional open repair. We demonstrate how by combining and modifying off-the-shelf devices during a hybrid procedure, one can create an endovascular solution tailored to the patient's complex anatomy, making use of an aberrant right subclavian artery, and allow for good clinical outcomes.

Percutaneous Treatment of Concomitant Severe Aortic Stenosis and Thoracoabdominal Aortic Aneurysm.

PURPOSE: Although rare in occurrence, symptomatic severe aortic stenosis and large thoracoabdominal aortic aneurysm (TAAA) found in combination pose a real therapeutic challenge, especially in elderly frail patients. Surgical approaches for combined treatment are complex and at high risk of complications while staged procedures carry the risk of an unfavorable evolution of the condition temporarily left untreated. Minimally invasive approaches may therefore prove a more suitable strategy for these patients. CASE REPORT: We present the case of a 78-year-old woman with symptomatic severe aortic stenosis (AS) and a TAAA of 7.8 cm in diameter. Transcatheter treatment of both conditions was successfully performed in a staged manner. The first intervention consisted of combined transfemoral transcatheter aortic valve implantation (TAVI) immediately followed by a zone 3 thoracic endovascular aortic endoprosthesis deployment. In order to reduce the extent of intercostal arteries coverage and mitigate the risk of medullar ischemia, a second-stage percutaneous endovascular treatment of the TAAA was performed with a customized 4-fenestration prosthesis. Early and 12-month clinical and radiologic follow-up were favorable. CONCLUSION: This case demonstrates how a strong multidisciplinary collaboration allows for successful resolution of complex clinical scenarios.

Caution: Air Embolism Related to Heli-Fx EndoAnchor System in Zone 2 Thoracic Aneurysm Repair.

PURPOSE: We report a case of significant air embolization to the ascending aorta immediately following deployment of EndoAnchors in the aortic arch during a procedure to correct a type 1A endoleak. CASE REPORT: The novel Heli-Fx EndoAnchor system (Medtronic Vascular, Santa Rosa, CA, USA) was used to deploy helical anchors in the distal aortic arch during a procedure to correct a type 1A endoleak following Zone 2 thoracic endovascular aortic repair of a saccular proximal descending thoracic aorta aneurysm (DTAA). The patient developed ST-segment elevations principally in the inferior leads and severe hypotension moments after EndoAnchor deployment at the proximal edge of the endograft. Transesophageal echocardiogram revealed severe right ventricular hypokinesis and a large amount of air in the ascending aorta. Subsequent management and clinical and radiological 30-day follow-up is presented in addition to a review of the literature and ex vivo testing with the Heli-Fx system to examine potential causes and solutions. CONCLUSION: Precautions, such as pressurized saline infusion to the side port of guiding sheath, should be used whenever manipulating catheters and sheaths such as the EndoAnchor system in the aortic arch to prevent this potentially lethal complication.

Surgical management of intravascular leiomyomatosis.

Intravascular leiomyomatosis is a rare entity defined by benign smooth uterine muscle cells that typically originate from the uterus with the potential to spread into veins possibly up to the heart. The diagnosis for patients presenting with cardiac symptoms may be difficult and imaging often interpreted as thrombus or atrial myxoma.

Dataset of the vascular e-Learning during the COVID-19 pandemic (EL-COVID) survey.

This dataset supports the findings of the vascular e-Learning during the COVID-19 pandemic survey (the EL-COVID survey). The General Data Protection Regulation (GDPR) of the European Union was taken into consideration in all steps of data handling. The survey was approved by the institutional ethics committee of the Primary Investigator and an online English survey consisting of 18 questions was developed ad-hoc. A bilingual English-Mandarin version of the questionnaire was developed according to the instructions of the Chinese Medical Association in order to be used in mainland People's Republic of China. Differences between the two questionnaires were minor and did affect the process of data collection. Both questionnaires were hosted online. The EL-COVID survey was advertised through major social media. All national and regional contributors contacted their respective colleagues through direct messaging on social media or by email. Eight national societies or groups supported the dissemination of the EL-COVID survey. The data provided demographics information of the EL-COVID participants and an insight on the level of difficulty in accessing or citing previously attended online activities and whether participants were keen on citing these activities in their Curricula Vitae. A categorization of additional comments made by the participants are also based on the data. The survey responses were filtered, anonymized and submitted to descriptive analysis of percentage.

Vascular e-Learning During the COVID-19 Pandemic: The EL-COVID Survey.

BACKGROUND: The corona virus disease (COVID-19) pandemic has radically changed the possibilities for vascular surgeons and trainees to exchange knowledge and experience. The aim of the present survey is to inventorize the e-learning needs of vascular surgeons and trainees as well as the strengths and weaknesses of vascular e-Learning. METHODS: An online survey consisting of 18 questions was created in English, with a separate bilingual English-Mandarin version. The survey was dispersed to vascular surgeons and trainees worldwide through social media and via direct messaging from June 15, 2020 to October 15, 2020. RESULTS: Eight hundred and fifty-six records from 84 different countries could be included. Most participants attended several online activities (>4: n = 461, 54%; 2-4: n = 300, 35%; 1: n = 95, 11%) and evaluated online activities as positive or very positive (84.7%). In deciding upon participation, the topic of the activity was most important (n = 440, 51.4%), followed by the reputation of the presenter or the panel (n = 178, 20.8%), but not necessarily receiving accreditation or certification (n = 52, 6.1%). The survey identified several shortcomings in vascular e-Learning during the pandemic: limited possibility to attend due to lack of time and increased workload (n = 432, 50.5%), no protected/allocated time (n = 488, 57%) and no accreditation or certification, while technical shortcomings were only a minor problem (n = 25, 2.9%). CONCLUSIONS: During the COVID-19 pandemic vascular e-Learning has been used frequently and was appreciated by vascular professionals from around the globe. The survey identified strengths and weaknesses in current e-Learning that can be used to further improve online learning in vascular surgery.

Safety of transition from a routine to a selective intensive care admission pathway after elective open aneurysm repair.

Background: There is a growing trend to implement intermediate care units to avoid unnecessary costs associated with intensive care unit (ICU) admission and associated resources. We sought to evaluate the safety of transitioning from a routine to a selective policy of postoperative transfer to the ICU for elective open abdominal aortic aneurysm (AAA) repair. Methods: This retrospective study included consecutive open elective AAA repair procedures performed at a single centre from Aug. 8, 2010, to Dec. 1, 2014. Patients were identified through a prospectively maintained database, and electronic charts were reviewed. Patients with interventions before Mar. 13, 2012, were routinely sent to the ICU after operation (group A). Patients treated after this date were sent directly to an intermediate care unit (group B) unless preoperative or intraoperative factors deemed them suitable for ICU admission. The primary outcome was in-hospital death; secondary outcomes were perioperative complications and length of stay. We used logistic and linear regression to determine the association between the use of an intermediate care unit and the primary and secondary outcomes after adjusting for confounders and clinically relevant covariates. Results: The cohort comprised 310 patients (266 men, 44 women) with a mean age of 69.7 (standard deviation 10.1) years and a mean AAA diameter of 61.2 mm (SD 9.6 mm). Groups A and B included 118 and 192 patients, respectively. Admission to the ICU was spared in 149 patients (77.6%) in group B. Only 2 patients (1.3%) in group B were subsequently admitted to the ICU. There was no statistically significant difference in in-hospital mortality or perioperative complications between the 2 groups on multivariable logistic regression. There was a nonsignificant trend toward slightly shorter length of stay in group B. Conclusion: In this single-centre experience with the majority of patients sent directly to an intermediate care unit, there was no statistically significant difference in mortality or morbidity between routine and selective ICU admission. Our results confirm the safety of a selective ICU admission pathway.

Contexte: La tendance est à la création d'unités de soins intermédiaires pour éviter les coûts inutiles entraînés par les séjours aux unités de soins intensifs (USI) et les ressources associées. La présente étude visait à évaluer la sécurité d'un transfert aux USI sélectif, plutôt que systématique, après la réparation ouverte élective d'un anévrisme aortique abdominal (AAA). Méthodes: Cette étude rétrospective portait sur des réparations ouvertes électives d'AAA consécutivement réalisées à un même centre pour la période du 8 août 2010 au 1er décembre 2014. Nous avons recensé les cas dans une base de données maintenue de manière prospective, puis avons étudié les dossiers électroniques. Les patients opérés avant le 13 mars 2012 ont été envoyés d'emblée à l'USI après l'intervention (groupe A). Ceux traités après cette date ont été transférés directement en soins intermédiaires (groupe B), sauf s'ils se qualifiaient pour l'admission à l'USI en raison de facteurs préopératoires ou intraopératoires. Le principal résultat à l'étude était les décès à l'hôpital; les résultats secondaires étaient les complications périopératoires et la durée du séjour. Un modèle de régression logistique a servi à déterminer les associations entre le transfert direct en soins intermédiaires et les résultats primaire et secondaires en tenant compte des facteurs de confusion et des covariables pertinentes sur le plan clinique. Résultats: La cohorte regroupait 310 patients (266 hommes et 44 femmes) dont l'âge moyen était de 69,7 ans (écart-type 10,1) et le diamètre moyen de l'AAA était de 61,2 mm (ET 9,6 mm). Les groupes A et B comptaient 118 et 192 patients, respectivement. L'admission aux soins intensifs a été évitée chez 149 patients (77,6 %) du groupe B. Seuls 2 (1,3 %) d'entre eux ont dû être admis à l'USI après coup. La régression logistique multivariable n'a montré aucune différence statistiquement significative entre les groupes à l'égard de la mortalité à l'hôpital et des complications périopératoires. Nous avons noté une réduction non significative de la durée de séjour pour le groupe B. Conclusion: Cette étude monocentrique où la majorité des patients ont été transférés directement en soins intermédiaires n'a pas révélé de différence statistiquement significative à l'égard de la mortalité et de la morbidité entre les admissions systématiques et sélectives aux USI. Nos résultats confirment que l'admission sélective en soins intensifs est une option sécuritaire.

Effect of e-Cigarettes Plus Counseling vs Counseling Alone on Smoking Cessation: A Randomized Clinical Trial.

Importance: Electronic cigarettes (e-cigarettes) for smoking cessation remain controversial. Objective: To evaluate e-cigarettes with individual counseling for smoking cessation. Design, Setting, and Participants: A randomized clinical trial enrolled adults motivated to quit smoking from November 2016 to September 2019 at 17 Canadian sites (801 individuals screened; 274 ineligible and 151 declined). Manufacturing delays resulted in early termination (376/486 participants, 77% of target). Outcomes through 24 weeks (March 2020) are reported. Interventions: Randomization to nicotine e-cigarettes (n = 128), nonnicotine e-cigarettes (n = 127), or no e-cigarettes (n = 121) for 12 weeks. All groups received individual counseling. Main Outcomes and Measures: The primary end point was point prevalence abstinence (7-day recall, biochemically validated using expired carbon monoxide) at 12 weeks, changed from 52 weeks following early termination. Participants missing data were assumed to be smoking. The 7 secondary end points, examined at multiple follow-ups, were point prevalence abstinence at other follow-ups, continuous abstinence, daily cigarette consumption change, serious adverse events, adverse events, dropouts due to adverse effects, and treatment adherence. Results: Among 376 randomized participants (mean age, 52 years; 178 women [47%]), 299 (80%) and 278 (74%) self-reported smoking status at 12 and 24 weeks, respectively. Point prevalence abstinence was significantly greater for nicotine e-cigarettes plus counseling vs counseling alone at 12 weeks (21.9% vs 9.1%; risk difference [RD], 12.8 [95% CI, 4.0 to 21.6]) but not 24 weeks (17.2% vs 9.9%; RD, 7.3 [95% CI, -1.2 to 15.7]). Point prevalence abstinence for nonnicotine e-cigarettes plus counseling was not significantly different from counseling alone at 12 weeks (17.3% vs 9.1%; RD, 8.2 [95% CI, -0.1 to 16.6]), but was significantly greater at 24 weeks (20.5% vs 9.9%; RD, 10.6 [95% CI, 1.8 to 19.4]). Adverse events were common (nicotine e-cigarette with counseling: 120 [94%]; nonnicotine e-cigarette with counseling: 118 [93%]; counseling only: 88 [73%]), with the most common being cough (64%) and dry mouth (53%). Conclusions and Relevance: Among adults motivated to quit smoking, nicotine e-cigarettes plus counseling vs counseling alone significantly increased point prevalence abstinence at 12 weeks. However, the difference was no longer significant at 24 weeks, and trial interpretation is limited by early termination and inconsistent findings for nicotine and nonnicotine e-cigarettes, suggesting further research is needed. Trial Registration: ClinicalTrials.gov Identifier: NCT02417467.

Carotid endarterectomy after systemic thrombolysis in a stroke population.

OBJECTIVE: Vascular specialists are increasingly being requested to perform carotid endarterectomy (CEA) after intravenous thrombolysis (IVT) for stroke patients, raising concerns about hemorrhagic complications. Few case series and registry reports have assessed the question, and even fewer studies have included a control group. The aim of this study was to evaluate the overall outcome of patients undergoing CEA after IVT and to compare them with contemporary patients with CEA after simple stroke (non-IVT group). It also aimed to evaluate the differences in outcomes of stroke patients requiring CEA between nonvascular and vascular centers. METHODS: The data of 169 consecutive patients who have undergone CEA after stroke in a single center was analyzed from January 2011 to December 2016, 27 of them (16%) having undergone previous IVT. A comparative analysis between the non-IVT and the IVT groups was performed. The time between stroke diagnosis and referral to a vascular specialist was also studied. RESULTS: Age, sex, and cardiovascular comorbidities were similar in both groups. Median time between stroke and CEA was 13 days (Q1-Q3, 8-23 days), with 16 of the 27 patients (59%) in the IVT group undergoing CEA less than 14 days after the initial event. There were three intracranial hemorrhages (2.1%) in the non-IVT group versus one (3.7%) in the IVT group (P = NS). The overall 30-day combined stroke and death rate was 7.1% (6.3% in the non-IVT group vs 11.1% in the IVT group; P = .70). The incidence of postoperative cervical hematoma requiring reoperation was similar in both groups (2.1% vs 3.7%; P = NS). The median time between diagnosis of stroke and referral to a vascular specialist was higher for patients in nonvascular centers compared with vascular centers (3.5 days vs 1.0 day; P < .001), which translated to fewer patients referred from nonvascular centers undergoing surgery in the 14-day window period (38% vs 67%; P < .001). CONCLUSIONS: In this retrospective analysis, CEA after IVT showed similar outcomes when compared with the overall CEA after stroke population. Stroke patients diagnosed in nonvascular centers were referred later than those in vascular centers and, although postoperative outcomes were similar, that was correlated with fewer patients undergoing surgery in a timely fashion.

Clinical Validation of a Semi-Automated Software for Maximal Diameter Measurements for Endovascular Repair Follow-up.

PURPOSE: To compare automated measurements of maximal diameter (Dmax) of abdominal aortic aneurysm (AAA) orthogonal to luminal or outer wall envelope centerline for endovascular repair (EVAR) follow-up. MATERIAL AND METHODS: Eighty-three consecutive patients with AAA treated by EVAR who had at least 1 computed tomography (CT) scan before and 2 CT scans after EVAR with at least 5 months' interval were included. Three-dimensional reconstruction of the AAA was achieved with dedicated segmentation software. Performances of automated calculation algorithms of Dmax perpendicular to lumen or outer wall envelope centerlines were then compared to manual measurement of Dmax on double-oblique multiplanar reconstruction (gold standard). Accuracy of automated Dmax measurements at baseline, follow-up, and progression over time was evaluated by calculation of mean error, Bland-Altman plot, and regression models. RESULTS: Disagreement in Dmax measurements between outer wall envelope algorithm and manual method was insignificant (mean error: baseline, -0.07 ± 1.66 mm, P = .7; first follow-up, 0.24 ± 1.69 mm, P = .2; last follow-up, -0.41 ± 2.74 mm, P = .17); whereas significant discrepancies were found between the luminal algorithm and the manual method (mean error: baseline, -1.24 ± 2.01 mm, P < .01; first follow-up, -1.49 ± 3.30 mm, P < .01; last follow-up, -1.78 ± 3.60 mm, P < .01). Dmax progression results were more accurate with AAA outer wall envelope algorithm compared to luminal method (P = .2). CONCLUSIONS: AAA outer wall envelope segmentation is recommended to enable automated calculation of Dmax perpendicular to its centerline during EVAR follow-up.

Anticoagulation Obtained below the Arterial Clamp Using a Single Fixed Bolus of Heparin in Vascular Surgery: A Pilot Study.

BACKGROUND: No clear recommendations exist regarding the optimal dosing of unfractionated heparin (UFH) during vascular surgery. Moreover, little is known about the effect of the UFH bolus downstream of the arterial clamp, where stasis and inflammation can possibly alter the anticoagulation obtained. METHODS: The aim of our prospective observational study was to assess anticoagulation below the arterial clamp and its clinical impact on the quality of revascularization. Thirty-six patients American Society of Anaesthesiologists physical status (ASA) grade I-III undergoing open revascularization surgeries were included. A baseline activated coagulation time (ACT) was obtained. Thirty minutes after a single bolus of 5,000 units of UFH, we measured an upstream ACT via a radial arterial catheter and an ACT below the arterial clamp via surgeon sampling. The quality of revascularization was assessed with preoperative and postoperative ankle-brachial and toe-brachial indexes (TBIs). RESULTS: The upstream postheparin ACT was significantly higher than the downstream postheparin ACT, with a mean difference of 24.3 sec (P < 0.0001). In 7 patients, the downstream ACT was lower than the baseline ACT. The upstream and downstream heparin concentrations were similar. There was no relationship between the downstream ACT and either ankle-brachial index improvement (28 patients, P = 0.51) or TBI improvement (27 patients, P = 0.21). CONCLUSIONS: Our study demonstrates a significant difference between the ACT above and below the arterial clamp without any clinical impact of this possibly insufficient anticoagulation. Further investigations are warranted to determine the optimal dose of UFH in vascular surgery. TRIAL REGISTRATION: Clinicaltrials.gov, NCT02477072.

An institutional study of time delays for symptomatic carotid endarterectomy.

OBJECTIVE: The aim of this study was to assess time delays between first cerebrovascular symptoms and carotid endarterectomy (CEA) at a single center and to systematically evaluate causes of these delays. METHODS: Consecutive adult patients who underwent CEAs between January 2010 and September 2011 at a single university-affiliated center (Centre Hospitalier de l'Université Montréal-Hôtel-Dieu Hospital, Montreal) were identified from a clinical database and operative records. Covariates of interest were extracted from electronic medical records. Timing and nature of the first cerebrovascular symptoms were also documented. The first medical contact and pathway of referral were also assessed. When possible, the ABCD2 score (age, blood pressure, clinical features, duration of symptoms, and diabetes) was calculated to calculate further risk of stroke. The nonparametric Wilcoxon test was used to assess differences in time intervals between two variables. The Kruskal-Wallis test was used to assess differences in time intervals in comparing more than two variables. A multivariate linear regression analysis was performed using covariates that were determined to be statistically significant in our sensitivity analyses. RESULTS: The cohort consisted of 111 patients with documented symptomatic carotid stenosis undergoing surgical intervention. Thirty-nine percent of all patients were operated on within 2 weeks from the first cerebrovascular symptoms. The median time between the occurrence of the first neurologic symptom and the CEA procedure was 25 (interquartile range [IQR], 11-85) days. The patient-dependent delay, defined as the median delay between the first neurologic symptom and the first medical contact, was 1 (IQR, 0-14) day. The medical-dependent delay was defined as the time interval between the first medical contact and CEA. This included the delay between the first medical contact and the request for surgery consultation (median, 3 [IQR, 1-10] days). The multivariate regression model demonstrated that the emergency physician as referral source (P = .0002) was statistically significant for reducing CEA delay. Patients who were investigated as an outpatient (P = .02), first medical contact with a general practitioner (P = .0002), and hospital center I as referral center (P = .045) were also found to be statistically significant to extend CEA delay when the model was adjusted over all covariates. In this center, there was no correlation between ABCD2 risk score and waiting time for surgery. CONCLUSIONS: The majority of our cohort falls short of the recommended 2-week interval to perform CEA. Factors contributing to reduced CEA delay were presentation to an emergency department, in-patient investigations, and a stroke center where a vascular surgeon is available.

Results of a randomized clinical trial of external beam radiation to prevent restenosis after superficial femoral artery stenting.

OBJECTIVE: The objective of this study was to evaluate the safety and efficacy of external beam radiation (EBR) in preventing restenosis after superficial femoral artery (SFA) stenting in comparison with a control group treated with SFA stenting only. METHODS: In this Institutional Review Board-approved study, patients who provided written informed consent were randomly assigned to 0 Gy or 14 Gy of EBR to the stent site 24 hours after SFA stenting. The primary end point was the angiographic binary restenosis rate 2 years after stenting. Categorical and continuous end points were respectively analyzed using logistic regression models and Wilcoxon tests. End points expressed as time to event were analyzed using a log-rank test. RESULTS: The study included 155 patients, 46 women and 109 men (mean age, 66 years; range, 45-85 years). In the 0 and 14 Gy groups, binary restenosis was present, respectively, in 44% (34/77) and 68% (52/76; P = .003) 2 years after stenting. Stent thrombosis occurred in 13% (10/78) of the 0 Gy group and in 33% (25/77) of the 14 Gy group (P = .003). Target lesion revascularization at 2 years was 26% (25/78) in the 0 Gy group and 30% (23/77) in the 14 Gy group (P = .56). There were no significant differences in total walking distances change from baseline to 2 years (46 ± 100 and 26 ± 79 m, respectively, in the 0 Gy and 14 Gy group; P = .25). There were no procedure-related deaths and no major amputations. CONCLUSIONS: A single 14 Gy dose of EBR to the SFA stenting site did not prevent in-stent restenosis.

Source of errors and accuracy of a two-dimensional/three-dimensional fusion road map for endovascular aneurysm repair of abdominal aortic aneurysm.

PURPOSE: To evaluate the accuracy and source of errors using a two-dimensional (2D)/three-dimensional (3D) fusion road map for endovascular aneurysm repair (EVAR) of abdominal aortic aneurysm. MATERIALS AND METHODS: A rigid 2D/3D road map was tested in 16 patients undergoing EVAR. After 3D/3D manual registration of preoperative multidetector computed tomography (CT) and cone beam CT, abdominal aortic aneurysm outlines were overlaid on live fluoroscopy/digital subtraction angiography (DSA). Patient motion was evaluated using bone landmarks. The misregistration of renal and internal iliac arteries were estimated by 3 readers along head-feet and right-left coordinates (z-axis and x-axis, respectively) before and after bone and DSA corrections centered on the lowest renal artery. Iliac deformation was evaluated by comparing centerlines before and during intervention. A score of clinical added value was estimated as high (z-axis < 3 mm), good (3 mm ≤ z-axis ≤ 5 mm), and low (z-axis > 5 mm). Interobserver reproducibility was calculated by the intraclass correlation coefficient. RESULTS: The lowest renal artery misregistration was estimated at x-axis = 10.6 mm ± 11.1 and z-axis = 7.4 mm ± 5.3 before correction and at x-axis = 3.5 mm ± 2.5 and z-axis = 4.6 mm ± 3.7 after bone correction (P = .08), and at 0 after DSA correction (P < .001). After DSA correction, residual misregistration on the contralateral renal artery was estimated at x-axis = 2.4 mm ± 2.0 and z-axis = 2.2 mm ± 2.0. Score of clinical added value was low (n = 11), good (n= 0), and high (n= 5) before correction and low (n = 5), good (n = 4), and high (n = 7) after bone correction. Interobserver intraclass correlation coefficient for misregistration measurements was estimated at 0.99. Patient motion before stent graft delivery was estimated at x-axis = 8 mm ± 5.8 and z-axis = 3.0 mm ± 2.7. The internal iliac artery misregistration measurements were estimated at x-axis = 6.1 mm ± 3.5 and z-axis = 5.6 mm ± 4.0, and iliac centerline deformation was estimated at 38.3 mm ± 15.6. CONCLUSIONS: Rigid registration is feasible and fairly accurate. Only a partial reduction of vascular misregistration was observed after bone correction; minimal DSA acquisition is still required.

Impact of contrast injection and stent-graft implantation on reproducibility of volume measurements in semiautomated segmentation of abdominal aortic aneurysm on computed tomography.

PURPOSE: To assess the impact of contrast injection and stent-graft implantation on feasibility, accuracy, and reproducibility of abdominal aortic aneurysm (AAA) volume and maximal diameter (D-max) measurements using segmentation software. MATERIALS AND METHODS: CT images of 80 subjects presenting AAA were divided into four equal groups: with or without contrast enhancement, and with or without stent-graft implantation. Semiautomated software was used to segment the aortic wall, once by an expert and twice by three readers. Volume and D-max reproducibility was estimated by intraclass correlation coefficients (ICC), and accuracy was estimated between the expert and the readers by mean relative errors. RESULTS: All segmentations were technically successful. The mean AAA volume was 167.0 ± 82.8 mL and the mean D-max 55.0 ± 10.6 mm. Inter- and intraobserver ICCs for volume and D-max measurements were greater than 0.99. Mean relative errors between readers varied between -1.8 ± 4.6 and 0.0 ± 3.6 mL. Mean relative errors in volume and D-max measurements between readers showed no significant difference between the four groups (P ≥ 0.2). CONCLUSION: The feasibility, accuracy, and reproducibility of AAA volume and D-max measurements using segmentation software were not affected by the absence of contrast injection or the presence of stent-graft. KEY POINTS: • AAA volumetry by semiautomated segmentation is accurate on CT following endovascular repair. • AAA volumetry by semiautomated segmentation is accurate on unenhanced CT. • Standardization of the segmentation technique maximizes the reproducibility of volume measurements.

Morphologic evaluation of ruptured and symptomatic abdominal aortic aneurysm by three-dimensional modeling.

OBJECTIVE: To identify geometric indices of abdominal aortic aneurysms (AAAs) on computed tomography that are associated with higher risk of rupture. METHODS: This retrospective case-control, institutional review board-approved study involved 63 cases with ruptured or symptomatic AAA and 94 controls with asymptomatic AAA. Three-dimensional models were generated from computed tomography segmentation and used for the calculation of 27 geometric indices. On the basis of the results of univariate analysis and multivariable sequential logistic regression analyses with a forward stepwise model selection based on likelihood ratios, a traditional model based on gender and maximal diameter (Dmax) was compared with a model that also incorporated geometric indices while adjusting for gender and Dmax. Receiver operating characteristic (ROC) curves were calculated for these two models to evaluate their classification accuracy. RESULTS: Univariate analysis revealed that gender (P = .024), Dmax (P = .001), and 14 other geometric indices were associated with AAA rupture at P < .05. In the multivariable analysis, adjusting for gender and Dmax, the AAA with a higher bulge location (P = .020) and lower mean averaged area (P = .005) were associated with AAA rupture. With these two geometric indices, the area under the ROC curve showed an improvement from 0.67 (95% confidence interval, 0.58-0.77) to 0.75 (95% confidence interval, 0.67-0.83; P < .001). Our predictive model showed comparable sensitivity (64% vs 60%) and specificity (79% vs 77%) with current treatment criteria based on gender and diameter at the point optimizing the Youden index (sensitivity + specificity - 1) on the ROC curve. CONCLUSIONS: Two geometric indices derived from AAA three-dimensional modeling were independently associated with AAA rupture. The addition of these indices in a predictive model based on current treatment criteria modestly improved the accuracy to detect aneurysm rupture.

Reduction in allogeneic blood products with routine use of autotransfusion in open elective infrarenal abdominal aortic aneurysm repair.

BACKGROUND AND OBJECTIVES: Concern about allogeneic blood product cost and complications has prompted interest in blood conservation techniques. Intraoperative autotransfusion (IAT) is currently not used routinely by vascular surgeons in open elective infrareanl abdominal aortic aneurysm (AAA) repair. The objective of this study is to review our experience with IAT and its impact on blood transfusion. METHODS: We retrospectively reviewed the medical records of consecutive patients treated electively over a 4-year period and compared 2 strategy related to IAT, routine use IAT (rIAT) versus on-demand IAT (oIAT). Outcomes measured were number of units of allogeneic red blood cells and autologous red blood cells transfused intraoperatively and postoperatively, preoperative, postoperative, and discharge hemoglobin levels; postoperative infections; length of postoperative intensive care stay; and length of hospital stay. T-independent and Fisher exact test were used. RESULTS: A total of 212 patients were included, 38 (18%) in the rIAT and 174 (82%) in the oIAT. Groups were similar except for an inferior creatinine and a superior mean aneurysm diameter for the rIAT group. Patients in the rIAT group had a lower rate of transfusion (26% vs 54%, P = .002) and a lower mean number of blood unit transfused (0.8 vs 1.8, P = .048). These findings were still more significant for AAA larger than 60 mm (18% rIAT vs 62% oIAT, P = .0001). Postoperative hemoglobin was superior in the rIAT group (107 vs 101 g/L, P = .01). Mean postoperative intensive care length of stay was shorter for the rIAT group (1.1 vs 1.8 days, P = .01). No difference was noted for infection, mortality, or hospital length of stay. CONCLUSION: The rIAT reduced the exposure to allogeneic blood products by more than 50%, in particular for patients with AAA larger than 60 mm. These results support the use of rIAT for open elective infrarenal AAA repair.

Bicarbonates for the prevention of postoperative renal failure in endovascular aortic aneurysm repair: a randomized pilot trial.

Purpose. Contrast-induced nephropathy (CIN) can contribute to acute kidney injury (AKI) in patients undergoing endovascular aortic aneurysm surgery. We evaluated the incidence of AKI together with the evolution of early biomarkers of renal injury in patients receiving bicarbonates or NaCl 0.9%. Methods. This study involved endovascular aortic aneurysm surgery patients. Group A (n = 17) received bicarbonates 3 mL/kg/h for 1 h before the procedure and then 1 mL/kg/h until 6 h after surgery, whereas group B (n = 17) received NaCl 0.9% using the same protocol. Biomarkers of renal injury from urine (interleukin-18 (IL-18), neutrophil gelatinase-associated lipocalin (NGAL), N-acetyl-ß-D-glucosaminidase (NAG), and kidney injury molecule 1 (KIM-1)) and blood (NGAL, cystatin C) were measured at baseline and 3, 24, and 48 h postoperatively. Results. AKI occurred in 1 patient (2.9%), in the bicarbonates group. IL-18, NAG, NGAL, and KIM-1 significantly rose in both groups after the surgery. There was a greater rise in NGAL and IL-18 after 3 h in the bicarbonates versus NaCl 0.9% group: 1115% versus 240% increase (P = 0.03) and 338% increase versus 1.4% decrease (P = 0.01). Conclusions. Despite significant elevation in biomarkers of renal injury, we demonstrated a low rate of AKI following endovascular aortic surgery.