Assessment of EVAR Competence: Validity of a Novel Rating Scale (EVARATE) in a Simulated Setting.

OBJECTIVES: The aims of this study were to investigate the validity evidence for a novel procedure specific assessment tool of competence in endovascular aortic repair (EVAR) and to establish a pass/fail level for the assessment. METHODS: Computed tomography angiography data of a 55 mm in diameter infrarenal aortic aneurysm was implemented into an endovascular simulator. Twenty-three physicians with varying EVAR experiences were video-recorded when performing a standard EVAR procedure on the simulator. Two experienced EVAR operators assessed the participants using the novel rating scale, "EndoVascular Aortic Repair Assessment of Technical Expertise" (EVARATE). Validity was studied according to the framework endorsed by the American Educational Research Association. RESULTS: The EVARATE scale had a high internal consistency (Cronbach's alpha = .90). The inter-rater reliability was acceptable (Intraclass Correlation Coefficient = .68, p = .005). Specific EVAR experience correlated significantly with the EVARATE score (Spearman's rho = .62, p = .002), but general endovascular experience did not. Consequence analysis showed that the EVARATE assessment could distinguish novices from intermediates (p < .01) and from experts (p < .001). A pass/fail score was determined using the contrasting groups' method. CONCLUSION: This paper presents the initial validity evidence for a novel procedure specific assessment tool, EVARATE, for operator competence in endovascular aortic repair investigated in a simulated setting. The assessment tool can be used to provide structured formative feedback to trainees.

Radiation exposure in patients treated with endovascular aneurysm repair: what is the risk of cancer, and can we justify treating younger patients?

Background Endovascular aneurysm repair (EVAR) is becoming the mainstay treatment of abdominal aortic aneurisms (AAA). The postoperative follow-up regime includes a lifelong series of CT angiograms (CTAs) at different intervals in addition to EVAR, which will confer significant cumulative radiation exposure over time. Purpose To examine the impact of age and follow-up regime over time on cumulative radiation exposure and attributable cancer risk after EVAR. Material and Methods We calculated a mean effective dose (ED) for the EVAR procedure, CTA, and plain abdominal X-rays (PAX). Cumulative ED was calculated for standard, complex, and simplified surveillance over 5, 10, and 15 years for different age groups. Results For EVAR, the mean ED was 34 mSv (range, 12-75 mSv) per procedure. For PAX, the ED was 1.1 mSv (range, 0.3-4.4 mSv), and for CTA it was 8.0 mSv (range, 2-20 mSv). For a 55-year-old man, an attributable cancer risk (ACR) in standard surveillance at 5 and 15 years of follow-up was 0.35% and 0.65%, respectively. The corresponding values were 0.22% and 0.37% for a 75-year-old man. When using a simplified follow-up, the ACRs for a 55-year-old at 5 and 15 years were 0.30% and 0.37%, respectively. These values were 0.18% and 0.21% for a 75-year-old man. A complex follow-up with half-yearly CTA over similar age and time span doubled the ACR. Conclusion Treating younger patients with EVAR poses a low ACR of 0.65% (15-year standard surveillance) compared to a lifetime cancer risk of 44%. A simplified surveillance should be used if treating younger patients, which will halve the ACR over 15 years.

Review of postoperative CT and ultrasound for endovascular aneurysm repair using Talent stent graft: can we simplify the surveillance protocol and reduce the number of CT scans?

BACKGROUND: Simplifying a postoperative surveillance protocol for endovascular aneurysm repair (EVAR) requires quality control comparing computerized tomography (CT) and ultrasound (US) results of abdominal aortic aneurysm (AAA) diameter measurements and endoleaks. PURPOSE: To test if US is comparable to CT, then assess a simplified follow-up with our conventional surveillance to assess patient safety. MATERIAL AND METHODS: During 2001-2006, data on 56 patients treated with Talent stent graft were prospectively registered. Median follow-up was 41.5 months (range, 2-94 months), with CT, US, and plain film abdomen X-rays (PFA) at 1, 6, and 12 months, then yearly. Bland-Altman plot was used to assess the agreement between CT and US measuring the AAA diameters and mixed model by the time effect to assess the difference in diameter over time. Sensitivity and specificity for detection of endoleaks by US, with CT as 'gold standard' were calculated. A simplified surveillance protocol with US/PFA at 6 and 8 weeks, CT/US/PFA at 1 year, and yearly US/PFA thereafter, was evaluated. CT was carried out when poor visibility, endoleak detected, AAA diameter increase (≥5 mm) on US or migration (≥10 mm) on PFA. This regime was compared with our conventional follow-up protocol. RESULTS: Diameter measurements on US appear comparable to CT with 91% specificity and 85% sensitivity for endoleaks detected by US. Using the simplified surveillance protocol no endoleaks, migrations, or endotension requiring treatment were overlooked. The simplified protocol generated 53 selective CT scans, avoiding approximately 144 CT scans. If further simplified by omitting the 1-year CT scan, one type II endoleak would be missed with a 1-year delay, eliminating a further 45 CT scans. CONCLUSION: US appears comparable to CT in the follow-up of Talent stent grafts in our institution. The proposed simplified surveillance protocol seems safe and can lead to a significant reduction in the number of CT scans.

Flow measurement before and after papaverine injection in above-knee prosthetic femoropopliteal bypass.

OBJECTIVE: To investigate the value of intraoperative blood flow measurements on early and long-term patency of above-knee prosthetic femoropopliteal bypass. METHODS: Flow was measured with a transit time flowmeter before (basal flow) and after an intragraft injection of papaverine (papaverine flow) in 87 operations (86 patients) between January 1990 and December 2001. Sixty-one grafts were of polyester, and 26 were of polytetrafluoroethylene. The operations were done under epidural anesthesia. The preoperative angiographic run-off score and clinical risk factors were recorded. Patency rates were analyzed with the product limit method and compared with the log-rank test. Variables found to be near significantly related to patency rates (P < .1) were included in a multivariate analysis performed with the Cox proportional hazard model. RESULTS: Basal flow measurements were not related to patency. The 2- and 5-year patency rates for grafts with a papaverine flow < or = 500 mL/min were 48% and 18% compared with 66% and 52% for grafts with a papaverine flow > or = 500 mL/min. These differences were statistically significant (P = .012, hazard ratio, 2.6). Two- and 5-year patency rates for smokers vs nonsmokers were 44% and 18% vs 69% and 54%. The patency rates for patients with poor vs good run-off were 42% and 27% vs 66% and 31%. Smoking (P = .008, hazard ratio, 2.75) and poor run-off score (P = .009, hazard ratio, 2.38) were found to be independent risk factors for reduced patency rates. Poor run-off score did not correlate with low values of measured basal or papaverine flow. CONCLUSIONS: Papaverine flow of < or = 500 mL/min is associated with reduced mid- and long-term patency rates. Additional antithrombotic medication and frequent follow-up for these grafts should be considered. The inferior patency rates of smokers and patients with poor run-off indicate that prosthetic bypass is less suitable for these groups of patients.

[Acute groin pain and femoral nerve deficit in a warfarin treated patient]. / Akutte lyskesmerter og ischias anterior hos warfarinbehandlet pasient.

Warfarin is frequently used as an anticoagulant. The most common and serious complication is bleeding. We present a 43-year-old warfarinized patient who was admitted with unilateral groin pain and a neurological deficit of the lumbar nerve root L1-4. A CT scan showed a haematoma in and behind the ilio-psoas muscle extending to below the inguinal ligament, due to a warfarin induced coagulation deficit (INR 7.0) which was reversed on admission with vitamin K. There is no conclusive evidence in the literature supporting either conservative or surgical treatment modalities. Our patient was successfully treated conservatively.