Inflow Artery Aneurysmal Degeneration After Long Term Native Arteriovenous Fistula for Haemodialysis.

OBJECTIVE: Inflow arterial aneurysms are a rare but serious complication after long term arteriovenous fistulae (AVF), probably due to arterial wall remodelling after an increase in flow and shear stress, and kidney transplantation with immunosuppressive therapy. This study aimed to describe the outcomes of surgical treatment and long term follow up in a large cohort. METHODS: This prospective cohort study collected data from patients with a true inflow artery aneurysm after AVF creation that was surgically repaired between 2010 and 2022. Anastomotic and infected aneurysms or post-puncture pseudoaneurysms were excluded. Demographic data, access characteristics, symptoms, treatment strategies, and long term follow up were recorded; patency was estimated using Kaplan-Meier survival analysis. RESULTS: During the study period, 28 patients (64% men, mean age 60.1 years) were treated surgically for aneurysmal degeneration of the axillary or brachial (n = 23) or radial (n = 5) artery after an AVF (10 distal, 18 proximal) performed a mean of 18.3 ± SD 7.9 years previously. Most AVFs were ligated or thrombosed, while all patients except one had previously received kidney transplants. Most of the cases (n = 18) were symptomatic: 13 with pain or swelling, four with distal embolisation, and one rupture. They were repaired by aneurysm partial excision and graft interposition (11 great saphenous vein, six ipsilateral basilic vein, three cephalic vein, and two PTFE graft), ligation (n = 3), or direct end to end anastomosis (n = 3). No major complications occurred before discharge, after a mean hospital stay of 2.4 days. After a mean follow up of 4.8 ± 3.3 years, three cases presented complications: two recurrent proximal brachial aneurysms were repaired with an additional proximal interposition graft (one with further late infected pseudoaneurysm) and an asymptomatic post-traumatic graft thrombosis. Five year primary and secondary patency was 84% and 96%, respectively. CONCLUSION: Aneurysmal degeneration of the inflow artery is an unusual complication during long term follow up of AVFs. Aneurysm excision and, in general, autogenous graft interposition using the saphenous or ipsilateral arm vein is a safe and effective strategy.

Multicenter European real-world utilization of VasQ anastomotic external support device for arteriovenous fistulae.

OBJECTIVE: To evaluate the outcomes of arteriovenous fistulae (AVF), created with VasQ external support device under standard clinical practice across three vascular access clinics. METHODS: This multinational, retrospective study evaluated prospectively collected clinical outcomes of both forearm and upper arm brachiocephalic AVF (BCAVF) created using the VasQ device. Fifty-one AVF patients were pooled from three different vascular access centers in Germany, Italy, and Spain. Postprocedure outcomes were assessed by flow measurement with ultrasound examination in all centers. Primary failure, usability, patency, and intervention rates during the study period were evaluated. RESULTS: Fifty-one VasQ devices were implanted during 37 forearm (36 radiocephalic and 1 ulnar-basilic AVF) and 14 BCAVF procedures. The study population comprised mostly males (73%) and Caucasians (82%), with a mean age of 62.5 years (range, 38-84 years) and mean body mass index of 29.2. One patient died owing to access-unrelated reasons, and one patient was lost to follow-up without AVF assessment after its creation. From the remaining 49, 3 patients had a follow-up of less than 4 weeks and were excluded from maturation, primary failure, and dialysis initiation analysis (because those factors could not be evaluated yet), leaving 46 patients in this evaluation. Maturation was achieved in 91% of patients. The primary failure rate was 9%. A primary patency rate of 77% was observed at 6, 12, and 18 months. The secondary patency rate was 91% at 6 months, and 85% at 12 months and 18 months. Both primary patency and secondary patency did not differ statistically when comparing forearm AVF with BCAVF (P > .25). Successful cannulation was achieved in 86% of patients (32/37) requiring dialysis with a median time from creation to cannulation of 46 days. Of those patients, the functional patency rate was 94%. Five patients underwent seven interventions to maintain or restore patency or functionality, with an overall rate of 0.248 interventions per patient-year. CONCLUSIONS: AVFs created with VasQ external support device demonstrated promising patency and functionality outcomes in multicentric real-world setting across the two most commonly used anatomic locations.

Impact of Target Visceral Vessel Anatomical Configuration on Early Complications Following Endovascular Repair of Thoracoabdominal Aortic Aneurysms.

BACKGROUND: Fenestrated and branched endovascular aortic repair (fEVAR-bEVAR) is a viable treatment option for thoracoabdominal aortic aneurysms but target visceral stent (TVS) endoleak and thrombosis remain a limiting factor. This study aims to evaluate TVS anatomy impact on 1-year risk of thrombosis and endoleak. METHODS: Patients treated with fEVAR-bEVAR for thoracoabdominal aneurysms between 2008 and 2020 in our centre were enrolled. We recorded comorbidities, operative details, 1-month postoperative CT scan (anatomical reference), and TVS behaviour: thrombosis and endoleak at 1-year follow-up. For each TVS, different points were identified using a centre-lumen-line: (A) TVS origin, (B) end of branch/fenestration, (C) visceral vessel entry, (D) end of TVS, (E) 1-cm distally. We analyzed TVS tortuosity ((centre-lumen-line/straight distance)-1, in %), image vector analysis of each segment in 2D (antero-posterior, left-right) and 3D (craneo-caudal displacement), and centre-lumen-line analysis (bending in ABC and CDE). Three independent observers performed a blind analysis, and anatomical differences between bEVAR/fEVAR, and cases with/without 1-year thrombosis and TVS endoleak, were compared using Kaplan-Meier curves (Log-Rank test), and t-test/Wilcoxon signed-ranks test respectively. RESULTS: Fifty-four patients (72 ± 713 years mean age; 182 TVS: 50 branches, 132 fenestrations) met the inclusion criteria. bEVAR cases had longer stents, with more caudal 3D angulation, and greater ABC angulated segment. After excluding bEVAR cases (low case number), 97 fEVAR TVS were analyzed. Five thrombosis and 7 endoleaks were observed. While anatomical configuration showed no association to thrombosis, it was related to endoleak: these cases presented more tortuous stents (5.97% ± 0.10, 21.40% ± 0,22, P = 0.011), with more angulated centre-lumen-line at ABC segment (5.69° ± 15.77°, 7.18° ± 7.77°, P = 0.012), and more upward-pointing stents in the origin of the stent (AB: 89.07° ± 24.46°, 109.09° ± 16.56°, P = 0.012; BC: 87.86° ± 21.10°, 113.11° ± 22.23°, P = 0.026). CONCLUSIONS: Anatomical configuration of the TVS is associated with type III endoleak, but not thrombosis, at 1-year following fEVAR. Cases with endoleak presented more tortuous stents, with a more angulated exit from the endograft, and upward-pointing of the origin of the stent.

Linoleic Acid Status in Cell Membranes Inversely Relates to the Prevalence of Symptomatic Carotid Artery Disease.

BACKGROUND AND PURPOSE: The red blood cell fatty acid composition objectively reflects the long-term dietary intake of several fatty acids. In patients undergoing carotid endarterectomy, we explored whether red blood cell status of selected fatty acids related to symptomatic carotid artery disease. METHODS: We included patients with symptomatic (n=22) and asymptomatic (n=23) carotid artery disease. We determined all-C18:1 trans, linoleic acid (LA, C18:2n6), alpha-linolenic acid (C18:3n3), and the omega-3 index (sum of eicosapentaenoic [C20:5n3] and docosahexaenoic [C22:6n3] acids) in both red blood cells and carotid plaque phospholipids by gas-chromatography. RESULTS: In a multivariate logistic regression analysis, we only observed a significant association for LA, whose red blood cell status was inversely related to symptomatic carotid artery disease (odds ratio, 0.116 [95% CI, 0.022-0.607], P=0.011, for each 1-SD increase). A similar result was observed for LA in carotid plaque phospholipids. CONCLUSIONS: Cell membrane enrichment in LA, which reflects its intake, was inversely related to symptomatic carotid disease. This increases evidence supporting a favorable role of dietary LA in vascular health.

Impact of Centralisation on Abdominal Aortic Aneurysm Repair Outcomes: Early Experience in Catalonia.

OBJECTIVE: Several studies have revealed high volume centres have better outcomes in the treatment of abdominal aortic aneurysms (AAAs), thus supporting centralisation of this procedure into selected centres based on volume. To date however, the real benefit of centralisation of this pathology has not been well demonstrated. The aim of this study was to analyse the impact of centralisation in to high volume centres (defined as those performing more than 30 cases per year) on AAA treatment outcomes carried out in Catalonia (Spain). METHODS: Data were collected from official national registries (HDMBD) for AAA treated by endovascular aneurysm repair (EVAR) or open repair (OR) over a nine year period. Two time periods were selected for comparison: before centralisation (2009-2014) and after complete centralisation (2015-2017). The primary objective was to determine short term mortality (in hospital and 30 day mortality) and length of stay (LOS) after intact AAA (iAAA) and ruptured AAA (rAAA) repair, before and after centralisation. Uni- and multivariable analyses were performed in order to identify independent outcomes predictors. RESULTS: A total of 3 501 iAAAs, including 1 124 (32.1%) OR and 2377 (67.9%) EVAR, and 409 rAAAs, including 218 (53.3%) OR and 191 (46.7%) EVAR, were identified. After centralisation, there was a significant decrease in overall mortality in iAAA repair (4.7% vs. 2.0%, p < .001) and rAAA repair (53.1% vs. 41.9%, p = .028). Mortality reduction in iAAAs was significant for OR (8.7% vs. 3.6%, p = .005), but not for EVAR (2.2% vs. 1.5%, p = .25). Overall LOS decreased as well, mainly in iAAAs (9.49 ± 10.84 vs. 7.44 ± 12.23 days, p < .001), and in particular in elective EVAR (7.32 ± 7.73 vs. 6.00 ± 8.97 days, p < .001). Multivariable analysis was identified before the centralisation period as an independent predictor for both mortality (odds ratio 1.484, 95% CI 1.098-2.005, p = .010) and LOS (B coefficient 1.146, 95% CI 0.218-2.073, p = .016). CONCLUSION: The implementation of a country based centralisation programme for AAA treatment led to a significant reduction in short term mortality, for both iAAA and rAAA, and mainly for elective OR. LOS also significantly decreased, mainly for elective EVAR. These results support the benefit of centralisation of AAA repair procedures.

European Society for Vascular Surgery (ESVS) Certification of Theoretical and Practical Competences in Basic Vascular Ultrasound: Validity Investigation of the Assessment Tools.

OBJECTIVE: The aim of this study was to gather validity evidence for the Assessment of basic Vascular Ultrasound Expertise (AVAUSE) tool, and to establish a pass/fail score for each component, to support decisions for certification. METHODS: A cross sectional validation study performed during the European Society for Vascular Surgery's annual meeting. Validity evidence was sought for the theoretical test and two practical tests based on Messick's framework. The participants were vascular surgeons, vascular surgical trainees, sonographers, and nurses with varying experience levels. Five vascular ultrasound experts developed the theoretical and two practical test components of the AVAUSE tool for each test component. Two stations were set up for carotid examinations and two for superficial venous incompetence (SVI) examinations. Eight raters were assigned in pairs to each station. Three methods were used to set pass/fail scores: contrasting groups' method; rater consensus; and extended Angoff. RESULTS: Nineteen participants were enrolled. Acceptable internal consistency reliability (Cronbach's alpha) for the AVAUSE theoretical (0.93), carotid (0.84), and SVI (0.65) practical test were shown. In the carotid examination, inter-rater reliability (IRR) for the two rater pairs was good: 0.68 and 0.78, respectively. The carotid scores correlated significantly with years of experience (Pearson's r = 0.56, p = .013) but not with number of examinations in the last five years. For SVI, IRR was excellent at 0.81 and 0.87. SVI performance scores did not correlate with years of experience and number of examinations. The pass/fail score set by the contrasting groups' method was 29 points out of 50. The rater set pass/fail scores were 3.0 points for both carotid and SVI examinations and were used to determine successful participants. Ten of 19 participants passed the tests and were certified. CONCLUSION: Validity evidence was sought and established for the AVAUSE comprehensive tool, including pass/fail standards. AVAUSE can be used to assess competences in basic vascular ultrasound, allowing operators to progress towards independent practice.

Diagnostic yield of 18F-FDG PET/CT in suspected diagnosis of vascular graft infection: A prospective cohort study.

BACKGROUND: Prosthetic vascular graft infection (PVGI) is a severe complication associated with high morbidity and mortality. Clinical diagnosis is complex, requiring image testing such as CT angiography or leukocyte scintigraphy, which has considerable limitations. The aim of this study was to know the diagnostic yield of PET/CT with 18F-Fluorodeoxyglucose (18F-FDG) in patients with suspected PVGI. METHODS: We performed a prospective cohort study including 49 patients with suspected PVGI, median age of 62 ± 14 years. Three uptake patterns were defined following published recommendations: (i) focal, (ii) patched (PVGI criteria), and (iii) diffuse (no PVGI criterion). RESULTS: Sensitivity, specificity, and positive and negative predictive values for 18F-FDG-PET/CT were 88%, 79%, 67%, and 93%, respectively. 18F-FDG-PET/CT identified 14/16 cases of PVGI showing a focal (n = 10) or patched pattern (n = 4), being true negative in 26/33 cases with either a diffuse pattern (n = 16) or without uptake (n = 10). Five of the seven false-positive cases (71%) showed a patched pattern and all coincided with the application of adhesives for PVG placement. CONCLUSIONS: 18F-FDG-PET/CT is a useful technique for the diagnosis of PVGI. A patched pattern on PET/CT in patients in whom adhesives were applied for prosthetic vascular graft placement does not indicate infection.

Climatic influence on the risk of abdominal aortic aneurysm rupture.

Our aim is to examine the effects of climatic conditions on the incidence of ruptured abdominal aortic aneurysms (rAAA) in Catalonia, Spain. We combined clinical data from the Public Health official registries in Catalonia, Spain (HD-MBDS) of all rAAA with local climatic data obtained from the closest meteorological station (69 stations, National Meteorological Service: MeteoCat) from 2008 to 2017. We analyzed the median, maximum, minimum, and variability of atmospheric pressure (hPa) and air temperature (°C), solar irradiation (MJ/m2), humidity (%), accumulated precipitation (mm), median wind, and maximum flaw direction and velocity (°, m/s), recorded on the days of events, the previous day, and mean results for 3, 7, and 30 days before, as well as seasonality. Seventy-five control days were randomly selected in a 1-year period around every rAAA day at the same meteorological station, and compared. A total of 717 days and locations with rAAA were identified, and 53,775 controls were randomly selected. For the rAAA days, there were significantly lower temperatures, lower solar global irradiation, and higher mean humidity levels in all time periods (p < 0.001, p < 0.001, p < 0.05); higher atmospheric pressure variability during 1 week and 1 month before (p = 0.011, p = 0.007); and they often occurred during autumn/winter (57.6%, p < 0.001). Logistic regression identified low mean temperatures on the days of ruptures and high mean humidity the week before as independent rupture predictors. In conclusion, low median temperatures the same day and high humidity during 1 week before were identified as independent predictors of rAAA occurrence. The role of climate on pathophysiologic mechanisms may require further investigation.

Influence of On-Call Vascular Surgery Team and Off-Hour Effect on Survival after Ruptured Abdominal Aortic Aneurysm.

BACKGROUND: Ruptured abdominal aortic aneurysms (rAAAs) represent a life-threatening emergency and carry a high community and in-hospital mortality, despite treatment and protocol advances. Identifying prognostic factors like the presence of on-call vascular surgery teams at first hospital admissions or times of hospital admissions can modify hospital protocols and mechanisms to ameliorate general outcomes. The aim of this study is to analyze the influence of on-call vascular surgery teams and off-hour admissions on survival after rAAAs in Catalonia, Spain. METHODS: We used data from public health official registries (based on registration of the minimum basic data set) to collect diagnosed cases of rAAAs (ICD-9-CM [International Classification of Diseases, Ninth Revision, Clinical Modification] 441.3) between January 2008 and December 2017. Variables included patient comorbidities, aneurysm treatment and type (endovascular treatment: ICD-9-CM 39.7 or open surgery: ICD-9-CM 398.44 and 39.25), in-hospital mortality, initial hospital admissions and transfers, days and times of admission, and final treatment received. We compared intervention rates and mortalities in all samples and operated cases, in patients initially admitted into tertiary vascular centers (with on-call vascular surgery teams) and community centers (without on-call vascular surgery teams), and the "off-hour effect" (night [22:00 hr to 8:00 hr] or weekend admissions [Friday to Sunday]) in mortality and type of surgery (open or endovascular repair). RESULTS: Of 717 patients with rAAAs (92% men), 561 (78.2%) were initially admitted into tertiary vascular centers and 156 (21.8%) into community centers. The rate of operated cases and global mortality was higher when cases were initially admitted into tertiary vascular centers (388, 69.2% vs. 46, 29.5%; P < 0.001 and 63.6% vs. 88.5%, P < 0.001, respectively), but when surgery was performed (excluding palliative nonoperated cases), the postoperative mortality in both groups was comparable (47.4% vs. 60.9%, P = 0.085), in both univariate and multivariate analysis. On the other hand, patients admitted during night hours (210, 29.3%) did not reveal noteworthy differences in the overall mortality (68.6% vs. 69.2%, P = 0.860) or postoperative mortality compared to those admitted during day hours (61.0% vs. 60.4%, P = 0.880). Weekend admissions neither showed worse results (280, 39.1%, admitted during weekend: overall mortality 70.4% vs. 68.2%, P = 0.541 and postoperative mortality 51.2% vs. 47.3%, P = 0.436). No significant dissimilarities were seen either in the use of endovascular or open repair at night (42.2% vs. 46.1%, P = 0.457) or weekend (41.8% vs. 47%, P = 0.287). CONCLUSIONS: Patients with rAAAs initially admitted into tertiary vascular centers have better overall survival rates than those initially admitted into community centers, mainly because of higher rates of rejected cases in community centers. No differences were seen in terms of mortality or type of surgery in the off-hour admitted cases (night hours or during weekends).

Aortic Curvature Remodeling after Thoracic Endovascular Aortic Repair: Assessing Device Conformability, Using Image Vector Analysis.

BACKGROUND: Aortic arch curvature can be straightened by endograft placement. However, different measurement methods with dissimilar follow-up and endografts have been published. The aim of this study was to corroborate, for the first time, the pliability of the Conformable Gore TAG Thoracic Endoprosthesis (W.L. Gore and Associates, Flagstaff, AZ, USA) into the aortic arch, using different image vector analysis. MATERIAL AND METHODS: We, retrospectively, analyzed patients primarily treated for thoracic aortic aneurysms and blunt traumatic aortic injuries by means of a Conformable Gore TAG Thoracic Endoprosthesis endograft proximally sealed into the aortic arch (zones Z1-Z3) in five different Spanish centers, between 2010 and 2017. The preoperative, one-month and six-month postoperative, computed tomography angiographies (CTAs) were obtained, creating accurate 3D center lumen line and external lumen line from the aortic valve to the renal arteries. Three different image analysis methods were used to compare modifications of the aortic curvature: first, segment analysis (angulations of the center lumen line when divided into seven precise segments, examining anterior-posterior, right-left, and cranial-caudal displacement), second, center lumen line analysis (bending of the center lumen line itself in seven definite points), and third, expected behavior (length of the endograft in the external lumen line). Two independent observers performed a blind analysis of all CTAs. Changes between preoperative and postoperative CTAs at one and six months are compared, and differences are viewed between cases sealed proximally (Z1-Z2) and distally (Z3) into the aortic arch. RESULTS: We analyzed 37 cases. At 1- and 6-month follow-ups, minimal changes occurred first in segment analysis (only a slight decrease of -2.0° in the XY plane at 10 cm from the brachiocephalic trunk at six-month follow-up was seen, P = 0.027). Second, center lumen line analysis again only showed negligible aortic curvature straightening (+3.5° at 10 cm from the brachiocephalic trunk at one month, P = 0.006, disappearing at six-month follow-up). Finally, good device length predictability was shown (interclass correlation coefficients: 0.995 and 0.994 at one and six months, P > 0.001). No differences were seen between cases proximally sealed into the proximal and distal aortic arch. CONCLUSIONS: Conformable Gore TAG Thoracic Endoprosthesis thoracic endograft showed a good pliability into the aortic arch and proximal thoracic aorta, with minimal changes in the aortic curvature after endograft placement in the short-term follow-up (up to six months). In addition, final endograft length into outer aortic curvature is highly predictable.

The best in vitro conditions for two and three parallel stenting during endovascular aneurysm repair.

OBJECTIVE: The aim of this study is to identify which endograft-parallel stent combinations and which degree of oversizing result in the most adequate fit in a juxtarenal abdominal aneurysmal neck, when using a double or triple parallel-stent (chimney) technique. METHODS: In vitro silicon, juxtarenal, abdominal aortic aneurysmal neck models of different diameters, with two and three side-branches (simulating both the renal and superior mesenteric arteries), were constructed. Two different endografts of three diameters each, with two or three parallel stents (of 6 mm and 6 mm; or 6 mm, 6 mm, and 8 mm) were tested (Endurant-II endograft [Medtronic Inc, Santa Rosa, Calif] with balloon-expandable BeGraft stent [Bentley InnoMed, Hechingen, Germany] and an Excluder endograft [W. L. Gore and Associates, Flagstaff, Ariz] with self-expanding Viabahn stent [W. L. Gore and Associates]), applying three endograft-oversizing degrees: recommended (15%), excessive (30%), and over-excessive (40%). After remodeling, using the kissing-balloon technique at 37°C (98.6°F), 36 endograft-stent-oversizing models were scanned by computed tomography. The area of the gutters, parallel-stent compression, and main endograft infolding were recorded. RESULTS: Increasing oversizing (15%, 30%, and 40%) revealed a nonsignificant propensity toward smaller gutters and similar parallel-stent compression, but it significantly augmented infolding, more in three parallel-stent models (0%, 0%, 67% and 0%, 33%, 83% of cases; P = .015 and .018, for two and three parallel-stent models; n = 36) and mainly for the Excluder-Viabahn combination. The Excluder-Viabahn showed significantly smaller gutters, but with higher stent compression, than Endurant-BeGraft combinations for both two and three parallel stents (8.2 mm2, 22.6 mm2; P = .002 and 14.4 mm2, 23.3 mm2; P = .009 gutter area; and 18%, 2%; P < .001 and 15%, 2%; P = .007 relative stent area compression, respectively). CONCLUSIONS: Better endograft stent apposition was usually attained when using 30% oversizing during two and three parallel-stent techniques. Higher oversizing was related to nonsignificant smaller gutters but higher rates of infolding. Smaller gutters, but higher stent compression and risk of infolding, were achieved with the Excluder-Viabahn than with the Endurant-BeGraft combination.

New Indications for Vascular Occluders in Secondary Repairs of Complex Aortic Pathologies.

In the recent years, the application of vascular plugs has been widespread in peripheral and aortic interventions. Between December 2013 and December 2014, 4 men, with different complex aortic pathologies (2 remaining aortic dissections and 2 thoracoabdominal aneurysms), successfully underwent endovascular treatment with Amplatzer Vascular Plug (St. Jude; St. Paul, MN). We report the different techniques applied in each case and the benefits of this approach in achieving thrombosis of false lumen, avoiding aneurysmal aorta enlargement and reducing risk of aortic rupture or death. Neither mortality nor complications were registered during a mean follow-up of 18 months.

Parallel-Stenting Technique in a Sandwich Configuration for Hypogastric Artery Preservation during Endovascular Aneurysm Repair: An In Vitro Study.

BACKGROUND: The aim of the study was to identify the best conditions in iliac sandwich procedure for hypogastric artery preservation during endovascular aneurysm repair, testing different devices, different oversizing (OS) degrees as well as different methods to measure it. METHODS: Four external iliac devices (16-mm Endurant and 12-mm Aorfix limb extensions; 11- and 13-mm Viabahn endografts) were tested with 2 distinct internal iliac stent grafts (8-mm Advanta V12 and 8-mm Viabahn) inside different proximal silicon iliac limb models (10, 12, 14, 16, and 18 mm), simulating an iliac sandwich procedure for hypogastric preservation. After remodeling all devices in a saline bath at 37°C, the combinations were computed tomography scanned. Gutter size, parallel-stent compression, and inadequate parallel-stent deployment or infolding were recorded. Oversizing between both parallel stents and the iliac limb models were examined in terms of added diameter, perimeter, and area being additionally compared. RESULTS: All three sizing methods (diameter, perimeter, and area) were highly correlated (diameter OS to perimeter and area OS correlation coefficient 0.998 and 0.997, respectively, P < 0.001 for both); thus, diameter OS was used for further comparisons. Increasing diameter OS (< 30%, 30-55%, 55-75%, and > 75%) showed a significant tendency toward smaller gutters (38.9, 12.2, 5.4, and 2.6 mm2, respectively, P < 0.001) but also increasing parallel-stent compression (13.5%, 28.9%, 43.9%, and 55.1%, P < 0.001) and infolding (0%, 0%, 38%, and 60%, P < 0.001). There were no significant differences between the analyzed devices. CONCLUSIONS: In iliac sandwich procedures, better apposition is usually achieved when using 30-55% diameter OS; higher OS is related to smaller gutters but higher rates of malpositioning and parallel-stent compression. No clear recommendations in material selection can be performed. All sizing methods are highly correlated and predictable.

Aortic Arch and Thoracic Aorta Curvature Remodeling after Thoracic Endovascular Aortic Repair.

BACKGROUND: The objective of this study was to analyze the original curvature of the aortic arch and thoracic aorta, and how it is modified after the placement of a thoracic endograft. METHODS: We retrospectively analyzed all patients primarily treated for thoracic aortic aneurysms and blunt traumatic aortic injuries by means of an endograft sealed into the aortic arch (zones, Z1-Z3) in 2 different centers (Vascular Surgery Division, Hospital Clinic, UB; and Vascular and Endovascular Surgery Department, Hospital Vall d'Hebron, UAB; Barcelona, Spain), between 2010 and 2015. The last preoperative and early (1-month) postoperative computed tomography angiography (CTA) was obtained for all cases, and an accurate 3-dimensional (3D) center lumen line was created, from the aortic valve to the renal arteries. Angles in 2-dimensional (2D; XY-plane) and 3D (referred to cranial-caudal Z-axis) were analyzed in: the distal ascending aorta, aortic arch, and thoracic aorta (at 5, 10, 15, and 20 cm from the brachiocephalic trunk [BCT]) and celiac trunk (CT). Changes in preoperative-postoperative CTA were compared independently for both diseases. Thirty-six cases were included (20 aneurysms, 16 blunt traumatic injuries; mean age, 69.5 and 42.5 years). RESULTS: After placement of an aortic endograft (sealed in Z1-Z2 in 30% of aneurysms and 75% of traumatic injuries; mean endograft length: 22.6 cm and 11.3 cm, respectively), a global left anterior displacement of the ascending aorta was observed (2D examination: -13.1° and -7.5°, P = 0.049 and 0.041, respectively). The 3D examination showed an average increase of the aortic angle at 5 and 10 cm from the BCT in the whole sample (+4.0°, +4.9° in reference to the vertical; P = 0.017, 0.001), softening the curvature of the proximal descending thoracic aorta. In addition, in traumatic injuries, a decrease in the aortic arch angle was observed (-3.5°, P = 0.030). CONCLUSIONS: Placement of an endograft into the aortic arch and proximal thoracic aorta engenders a softening of the proximal descending thoracic aorta curvature, increasing its angle from the vertical. In blunt traumatic aortic injuries (with shorter and more proximally sealed endografts), an additional decrease of the aortic arch angle (3.5° more vertical), was observed.

Observational study of surveillance based on the combination of online dialysance and thermodilution methods in hemodialysis patients with arteriovenous fistulas.

BACKGROUND/AIMS: Online dialysance (Kt) and thermodilution (BTM-Qa) methods could be important components in vascular access monitoring programs. This study evaluated the efficiency of these two methods in reducing the thrombosis rate and access-related costs compared with a historic control group. METHODS: We studied 148 hemodialysis patients with arteriovenous fistulas (control group, n = 74) for 2 years. During the study period, the indications for vascular treatments were the Kt reduction ≥20% with respect to baseline values or Qa <500 ml/min (or a decrease in flow >20%). RESULTS: During the study period, we detected 16 cases of vascular dysfunction. The Kt value after vascular treatment was 71.1 liters (59 liters; p = 0.001) and BTM-Qa was 1,218.6 ml/min (519.7 ml/min; p = 0.001). Compared with the control group, the thrombosis rate was 0.027 versus 0.148 episodes/patient-year (p = 0.009) and the total access-related cost was EUR 22,293 versus 47,467 (p = 0.033). CONCLUSIONS: This study suggests that a combined monitoring program based on Kt and BTM-Qa represents an effective screening method that significantly reduces the thrombosis rate and economic costs of vascular treatments.

Quality assurance in surgical trials of arteriovenous grafts for haemodialysis: A systematic review, a narrative exploration and expert recommendations.

BACKGROUND: Introducing new procedures and challenging established paradigms requires well-designed randomised controlled trials (RCT). However, RCT in surgery present unique challenges with much of treatment tailored to the individual patient circumstances, refined by experience and limited by organisational factors. There has been considerable debate over the outcomes of arteriovenous grafts (AVG) compared to AVF, but any differences may reflect differing practice and potential variability. It is essential, therefore, when considering an RCT of a novel surgical procedure or device that quality assurance (QA) is defined for both the new approach and the comparator. The aim of this systematic review was to evaluate the QA standards performed in RCT of AVG using a multi-national, multi-disciplinary approach and propose an approach for future RCT. METHOD: The methods of this have been previously registered (PROSPERO: CRD420234284280) and published. In summary, a four-stage review was performed: identification of RCT of AVG, initial review, multidisciplinary appraisal of QA methods and reconciliation. QA measures were sought in four areas - generic, credentialing, standardisation and monitoring, with data abstracted by a multi-national, multi-speciality review body. RESULTS: QA in RCT involving AVG in all four domains is highly variable, often sub-optimally described and has not improved over the past three decades. Few RCT established or defined a pre-RCT level of experience, none documented a pre-trial education programme, or had minimal standards of peri-operative management, no study had a defined pre-trial monitoring programme, and none assessed technical performance. CONCLUSION: QA in RCT is a relatively new area that is expanding to ensure evidence is reliable and reproducible. This review demonstrates that QA has not previously been detailed, but can be measured in surgical RCT of vascular access, and that a four-domain approach can easily be implemented into future RCT.