Carotid surgery : Potential of cerebrovascular PET measurements

Rauwerda, J.A. [Promotor]Lammertsma, A.A. [Promotor]Boellaard, R. [Copromotor

Long-Term Locoregional Vascular Morbidity After Isolated Limb Perfusion and External-Beam Radiotherapy for Soft Tissue Sarcoma of the Extremity

Background: Isolated limb perfusion (ILP) with tumor necrosis factor alpha (TNF-alpha) and melphalan, followed by delayed surgical resection and adjuvant external-beam radiotherapy is a limb salvage treatment strategy for locally advanced soft tissue sarcomas. The long-term vascular side effects of this combined procedure were evaluated. Methods: Thirty-two patients were treated for a locally advanced sarcoma of the upper (n = 5) or lower limb (n = 27). All patients underwent a noninvasive vascular work-up. Results: Five patients underwent a leg amputation, in two cases due to critical leg ischemia 10 years after ILP. With a median follow-up of 88 (range, 17-159) months, none of the patients with a salvaged lower leg (n = 22) experienced peripheral arterial occlusive disease. Ankle-brachial index (ABI) measurements in the involved leg (median, 1.02; range, .50-1.20) showed a significant decrease compared with the contralateral leg (median, 1.09; range, .91-1.36, P = .001). Pulsatility index (PI) was decreased in the treated leg in 17 of 22 patients at the femoral level (median, 6.30; range, 2.1-23.9 vs. median, 7.35; range, 4.8-21.9; P = .011) and in 19 of 20 patients at popliteal level (median, 8.35; range, 0-21.4 vs. median, 10.95; range, 8.0-32.6; P <.0005). In patients with follow-up of > 5 years, there was more often a decrease in ABI (P = .024) and PI at femoral level (P = .011). Conclusions: ILP followed by resection and external-beam radiotherapy can lead to major late vascular morbidity that requires amputation. Objective measurements show a time-related decrease of ABI and femoral PI in the treated extremity

Day-to-Day Test–Retest Variability of CBF, CMRO2, and OEF Measurements Using Dynamic 15O PET Studies

Contains fulltext : 169592.pdf (publisher's version ) (Open Access)PURPOSE: We assessed test-retest variability of cerebral blood flow (CBF), cerebral blood volume (CBV), cerebral metabolic rate of oxygen (CMRO(2)), and oxygen extraction fraction (OEF) measurements derived from dynamic (15)O positron emission tomography (PET) scans. PROCEDURES: In seven healthy volunteers, complete test-retest (15)O PET studies were obtained; test-retest variability and left-to-right ratios of CBF, CBV, OEF, and CMRO(2) in arterial flow territories were calculated. RESULTS: Whole-brain test-retest coefficients of variation for CBF, CBV, CMRO(2), and OEF were 8.8%, 13.8%, 5.3%, and 9.3%, respectively. Test-retest variability of CBV left-to-right ratios was <7.4% across all territories. Corresponding values for CBF, CMRO(2), and OEF were better, i.e., <4.5%, <4.0%, and <1.4%, respectively. CONCLUSIONS: The test-retest variability of CMRO(2) measurements derived from dynamic (15)O PET scans is comparable to within-session test-retest variability derived from steady-state (15)O PET scans. Excellent regional test-retest variability was observed for CBF, CMRO(2), and OEF. Variability of absolute CBF and OEF measurements is probably affected by physiological day-to-day variability of CBF

Central coordination as an alternative for local coordination in a multicenter randomized controlled trial: the FAITH trial experience

Contains fulltext : 110505.pdf (publisher's version ) (Open Access)BACKGROUND: Surgeons in the Netherlands, Canada and the US participate in the FAITH trial (Fixation using Alternative Implants for the Treatment of Hip fractures). Dutch sites are managed and visited by a financed central trial coordinator, whereas most Canadian and US sites have local study coordinators and receive per patient payment. This study was aimed to assess how these different trial management strategies affected trial performance. METHODS: Details related to obtaining ethics approval, time to trial start-up, inclusion, and percentage completed follow-ups were collected for each trial site and compared. Pre-trial screening data were compared with actual inclusion rates. RESULTS: Median trial start-up ranged from 41 days (P25-P75 10-139) in the Netherlands to 232 days (P25-P75 98-423) in Canada (p = 0.027). The inclusion rate was highest in the Netherlands; median 1.03 patients (P25-P75 0.43-2.21) per site per month, representing 34.4% of the total eligible population. It was lowest in Canada; 0.14 inclusions (P25-P75 0.00-0.28), representing 3.9% of eligible patients (p < 0.001). The percentage completed follow-ups was 83% for Canadian and Dutch sites and 70% for US sites (p = 0.217). CONCLUSIONS: In this trial, a central financed trial coordinator to manage all trial related tasks in participating sites resulted in better trial progression and a similar follow-up. It is therefore a suitable alternative for appointing these tasks to local research assistants. The central coordinator approach can enable smaller regional hospitals to participate in multicenter randomized controlled trials. Circumstances such as available budget, sample size, and geographical area should however be taken into account when choosing a management strategy. TRIAL REGISTRATION: ClinicalTrials.gov: NCT00761813

Factors Associated with Revision Surgery after Internal Fixation of Hip Fractures

Background: Femoral neck fractures are associated with high rates of revision surgery after management with internal fixation. Using data from the Fixation using Alternative Implants for the Treatment of Hip fractures (FAITH) trial evaluating methods of internal fixation in patients with femoral neck fractures, we investigated associations between baseline and surgical factors and the need for revision surgery to promote healing, relieve pain, treat infection or improve function over 24 months postsurgery. Additionally, we investigated factors associated with (1) hardware removal and (2) implant exchange from cancellous screws (CS) or sliding hip screw (SHS) to total hip arthroplasty, hemiarthroplasty, or another internal fixation device. Methods: We identified 15 potential factors a priori that may be associated with revision surgery, 7 with hardware removal, and 14 with implant exchange. We used multivariable Cox proportional hazards analyses in our investigation. Results: Factors associated with increased risk of revision surgery included: female sex, [hazard ratio (HR) 1.79, 95% confidence interval (CI) 1.25-2.50; P = 0.001], higher body mass index (fo

The impact of training in unselected patients on mortality and morbidity in carotid endarterectomy in a vascular training center and the recommendations of the European Board of Surgery Qualification in Vascular Surgery

Purpose: To investigate the impact of training of vascular fellows on the results of carotid endarterectomy (CEA) in unselected patients and to evaluate the recommendations of the European Board of Surgery Qualification in Vascular Surgery (EBSQ-VASC) concerning CEA. Methods: Complication rates and selection criteria of all CEAs, performed between 1995 and 2000 (n=200) were retrospectively analysed and correlated to operating surgeon; supervised, nonsupervised vascular trainees, and consultant vascular surgeons. The number of CEAs were compared with the required minimal procedures according to the EBSQ-VASC. Results: Selection criteria for CEA did not differ significantly between operating surgeon groups, except that combined procedures were more performed by nonsupervised trainees and asymptomatic stenosis by consultant surgeons. The overall persistent disabling stroke rate and stroke-related mortality was 3%, with 4.3% in the supervised group, 0% in the unsupervised, and 2.8% in the consultant surgeon group, respectively. The amount of CEAs corresponded to the demands of the EBSQ-VASC. Conclusions: In our institution, no significant differences in neurological morbidity and mortality following CEA could be demonstrated in relation to surgeon training level. The number of CEAs performed by residents fulfil the criteria of the EBSQ-VASC. We conclude that CEA can be safely taught to vascular trainees in unselected patients in a vascular training centre

Is semi-closed endarterectomy of the superficial femoral artery combined with a short venous bypass in case of insufficient venous material an acceptable alternative for limb-threatening ischemia?

Background. The aim of this study was to analyse the results of infragenual arterial revascularisation using semiclosed endarterectomy of the superficial femoral artery combined with a short venous bypass in patients with critical leg ischemia and insufficient venous material for a straightforward femorocrural reconstruction. Methods. From December 1990 through December 1998 thirty patients were studied (22 males and 8 females; mean age 65 years, range 31-92 years). The mean follow-up was 26 months (range 1-96 months). Cumulative primary patency and limb salvage rates were calculated according to life-table analysis. Results. The cumulative primary patency was 60.3% at 1 year and 48.4% at 3 years. The limb salvage rate was 68.6% at 1 and at 3 years. Conclusions. In patients with limb-threatening ischemia and lack of venous material for a straightforward venous femorocrural bypass, semi-closed endarterectomy of the superficial femoral artery combined with a short popliteo-crural bypass provides a good alternative