Comparison of Modified Chandler, Roller Pump, and Ball Valve Circulation Models for In Vitro Testing in High Blood Flow Conditions: Application in Thrombogenicity Testing of Different Materials for Vascular Applications

Three different models, a modified Chandler loop, roller pump, and a new ball valve model (Hemobile), were compared with regard to intrinsic damage of blood components and activation of platelets. The Hemobile was used for testing of polymer tubes. High flow was not possible with the Chandler loop. The roller pump and the Hemobile could be adjusted to high flow, but he pump induced hemolysis. Platelet numbers were reduced in the roller pump and Chandler loop (P < 0.05), but remained high in the Hemobile. Platelet aggregation was reduced in all models. The Hemobile was applied for testing vascular graft materials, and allowed different circuits circulated simultaneously at 37°C. ePTFE, Dyneema Purity UHMWPE fiber and PET fiber based tubes, all showed hemolysis below 0.2% and reduced platelet count and function. Binding of fibrin and platelets was higer on PET, inflammatory markers were lowest on Dyneema Purity UHMWPE. We concluded that the Hemobile minimally affects blood and could be adjusted to high blood flows, simulating arterial shear stress. The Hemobile was used to measure hemocompatibility of graft material and showed Dyneema Purity UHMWPE fiber in many ways more hemocompatible than ePTFE and PET

Outcome of Fenestrated Endovascular Aneurysm Repair in Octogenarians:A Retrospective Multicentre Analysis

Objective: An ageing population leads to more age related diseases, such as complex abdominal aortic aneurysms (AAA). Patients with complex AAAs and multiple comorbidities benefit from fenestrated endovascular aneurysm repair (FEVAR), but for the elderly this benefit is not completely clear. Methods: Between 2001 and 2016 all patients treated for complex AAA by FEVAR at two tertiary referral centres were screened for inclusion. Group 1 consisted of patients aged 80 years and older and group 2 of patients younger than 80 years of age. The groups were compared for peri-operative outcome, as well as patient and re-intervention free survival, and target vessel patency during follow up. Results: Group 1 consisted of 42 patients (median age 82 years; interquartile range [IQR] 81–83 years) and group 2 of 230 patients (median age 72 years; IQR 67–77 years). No differences were seen in pre-operative comorbidities, except for age and renal function. Renal function was 61.4 mL/min/1.73 m2 vs.74.5 mL/min/1.73 m2 (p < .01). No differences were seen between procedures, except for a slightly longer operation time in group two. Median follow up was 26 and 32 months, respectively. No difference was seen between the groups for estimated cumulative overall survival (p = .08) at one, three, and five years, being 95%, 58%, and 42% for group 1, and 88%, 75%, and 61% for group 2, respectively. There was no difference seen between groups for the estimated cumulative re-intervention free survival (p = .95) at one, three, and five years, being 84%, 84%, and 84% in group 1, respectively, and 88%, 84%, and 82% in group 2, respectively. Ultimately, no difference was seen between groups for the estimated cumulative target vessel patency (p = .56) at one, three, and five years, being 100%, 100%, and 90% for group 1, and 96%, 93% and 92% for group 2, respectively. Conclusion: Age itself is not a reason to withhold FEVAR in the elderly, and choice of treatment should be based on the patient's comorbidities and preferences

Endovascular treatment of popliteal artery aneurysms: Results of a prospective cohort study

ObjectivePopliteal artery aneurysms can be treated endovascularly with less perioperative morbidity compared with open repair. To evaluate suitability of the endovascular technique and the clinical results of this treatment, we analyzed a prospective cohort of consecutive popliteal aneurysms referred to a tertiary university vascular center.MethodsAll popliteal artery aneurysms between June 1998 and June 2004 that measured >20 mm in diameter were analyzed for endovascular repair. Anatomic suitability was based largely on quality of the proximal and distal landing zone as determined by angiography. Endovascular treatment was performed by using a nitinol-supported expanded polytetrafluoroethylene lined stent graft introduced through the common femoral artery.ResultsWe analyzed 67 aneurysms in 57 patients. Ten aneurysms (15%) were excluded from endovascular repair, or from any repair at all, for various reasons. The remaining 57 (85%) were treated endovascularly, of which 5 were treated emergently for acute ischemia. During a mean 24-month follow-up, 12 stent grafts (21%) occluded. Primary and secondary patency rates were 80% and 90% at 1 year, and 77% and 87% at 2 years of follow-up. Postoperative treatment with clopidogrel proved to be the only significant predictor for success.ConclusionsEndovascular repair of a popliteal artery aneurysm is feasible. Changes in the material used and the addition of clopidogrel may improve patency rates

Standardised Frailty Indicator as Predictor for Postoperative Delirium after Vascular Surgery:A Prospective Cohort Study

AbstractObjectivesTo determine whether the Groningen Frailty Indicator (GFI) has a positive predictive value for postoperative delirium (POD) after vascular surgery.MethodsBetween March and August 2010, 142 consecutive vascular surgery patients were prospectively evaluated. Preoperatively, the GFI was obtained and postoperatively patients were screened with the Delirium Observation Scale (DOS). Patients with a DOS-score ≥3 points were assessed by a geriatrician. Delirium was defined by the DSM-IV-TR criteria. Primary outcome variable was the incidence of POD. Secondary outcome variables were any surgical complication and hospital length of stay (HLOS) (>7 days).ResultsTen patients (7%) developed POD. The highest incidence of POD was found after aortic surgery (17%) and amputation procedures (40%). Increased comorbidities (p = 0.006), GFI score (p = 0.03), renal insufficiency (p = 0.04), elevated C-reactive protein (p = 0.008), high American Society of Anaesthesiologists score (p = 0.05), a DOS-score of ≥3 points (p = 0.001), post-operative intensive care unit admittance (p = 0.01) and HLOS ≥7 days (p = 0.005) were risk factors for POD. The GFI score was not associated with a prolonged HLOS. A mean number of 2 ± 1 (range 0–5) complications were registered. The receiver operator characteristics (ROC) area under the curve for the GFI was 0.70.ConclusionsThe GFI can be helpful in the early identification of POD after vascular surgery in a select group of high-risk patients

Visceral stent patency in fenestrated stent grafting for abdominal aortic aneurysm repair

ObjectiveFenestrated endovascular abdominal aortic aneurysm repair (F-EVAR) has been introduced for treatment of aneurysms in which visceral arteries are incorporated. Patency of target vessels has been reported to be excellent. Results of the use of stent grafts to accommodate visceral arteries in F-EVAR are presented in this study, including an overview of factors that affect outcome.MethodsAll patients treated with fenestrated stent grafts in a single center between November 2001 and October 2011 were reviewed. Patients treated for suprarenal, juxtarenal, and infrarenal short-necked aortic aneurysms were included. Patients with thoraco-abdominal aneurysms or aneurysms treated with grafts with fixed side branches were excluded. Polytetrafluoroethylene covered stents were used routinely since June 2005. Target vessels and stents were examined using computed tomography angiography reconstructions. Primary end points were primary patency, defined as the absence of occlusion, and loss of renal function. Secondary end points were technical success, stenosis (defined as a ≥50% angiographic diameter reduction), stent fracture, and mortality.ResultsA total of 138 patients with a median age of 73 years (range, 50-91 years) met the inclusion criteria. Median computed tomography angiography follow-up was 13 months (range, 1-97 months). In total, 392 target vessels were provided with 140 scallops and 252 fenestrations. Visceral stents (−grafts) were placed in 254 target vessels. Technical success was obtained in 249 arteries (98.0%). Overall stent patency of target vessels was 95.7% at 1 year and 88.6% at 4 years. Renal artery stent patency was 97.4% at 1 year and 91.2% at 4 years (96.8% and 89.1% for uncovered stents; 97.3% and 92.4% for covered stents, respectively). There was no significant difference in patency between covered and uncovered stents in renal arteries (P = .71). Renal artery stenosis occurred in 26 stented arteries (11.3%) and occlusion in seven arteries. Renal artery stent stenosis occurred significantly more in uncovered than in covered stents (P = .04). Stent fractures occurred more in uncovered than in covered stents (P = .01) and was associated with a significantly lower visceral stent patency rate (P < .01). During follow-up, 13 patients developed permanent renal function impairment (9.4%), of which two required permanent dialysis (1.4%). Renal dysfunction was significantly associated with renal stent occlusion or stenosis (P < .01).ConclusionsPatency rates of visceral artery stent (–grafts) in F-EVAR were 95.7% at 1 year and 88.6% at 4 years. Patency rates were affected by stent fractures, which occurred more in uncovered compared with covered stents. Renal artery stent stenosis occurred more in uncovered compared with covered stents. Renal dysfunction was significantly associated with renal stent occlusion or stenosis

Is emergency endovascular aneurysm repair associated with higher secondary intervention risk at mid-term follow-up?

ObjectiveThe study assessed mid-term outcome of emergency endovascular repair for acute infrarenal abdominal aortic aneurysms, with special attention to secondary interventions.MethodsBetween May 1998 and August 2005, 56 patients underwent emergent endovascular repair for a ruptured abdominal aortic aneurysm (n = 34) or an acute nonruptured abdominal aortic aneurysm (n = 22). During the same period, 322 consecutive patients underwent elective endovascular aneurysm repair and were used as control group. Five types of stent grafts were used: Vanguard, Talent, Excluder, Zenith, and Quantum. Follow-up included abdominal radiograph, duplex ultrasound scanning, and computed tomographic angiography. Outcome measures included all-cause and aneurysm-related mortality, complications, and secondary interventions.ResultsMortality at 30 days was 18%, 5%, and 1% in the ruptured, acute nonruptured, and elective aneurysm groups, respectively. Overall mean follow-up was 38 ± 26 months. In the ruptured aneurysm group, survival was 67.8% ± 8.6% at 1 year and 62.1% ± 9.5% at 2 and 3 years. Seven secondary interventions (4 early and 3 late) were required in five patients (15%), with a cumulative risk of 9.2% ± 5.1% at 1 year and 16.2% ± 8.2% at 2 and 3 years. In the acute nonruptured aneurysm group, survival was 90.9% ± 6.1% at 1 year, 84.8% ± 8.2% at 2 years, and 76.4% ± 10.9% at 3 years. Four secondary interventions (1 early and 3 late) were required in four patients (18%), with a cumulative risk of 9.6% ± 6.5% at 1 and 2 years and 20.9% ± 12.0% at 3 years. In the elective aneurysm (control) group, survival was 95.2% ± 1.2% at 1 year, 89.9% ± 1.8% at 2 years, and 86.2% ± 2.1% at 3 years. A total of 51 secondary interventions (4 early, 47 late) were required in 38 patients (12%), with a cumulative risk of 4.2% ± 1.1% at 1 year, 7.6% ± 1.6% at 2 years, and 12.9% ± 2.2% at 3 years.ConclusionsTo our surprise, emergency endovascular aneurysm repair did not present with higher secondary intervention rate at mid-term follow-up