Mark J.W. Koelemay

Diagnostic Performance of Computed Tomography Angiography in Peripheral Arterial Disease: A Systematic Review and Meta-analysis

CONTEXT Computed tomography angiography (CTA) is an increasingly attractive imaging modality for assessing lower extremity peripheral arterial disease (PAD). OBJECTIVE To determine the accuracy of CTA compared with intra-arterial digital subtraction angiography (DSA) in differentiating extent of disease in patients with PAD. DATA SOURCES AND STUDY SELECTION Search of MEDLINE (January 1966-August 2008), EMBASE (January 1980-August 2008), and the Database of Abstracts of Reviews of Effectiveness for studies comparing CTA with intra-arterial DSA for PAD. Eligible studies compared multidetector CTA with intra-arterial DSA, included at least 10 patients with intermittent claudication or critical limb ischemia, aimed to detect more than 50% stenosis or arterial occlusion, and presented either 2 x 2 or 3 x 3 contingency tables (< or = 50% stenosis vs > 50% stenosis or occlusion), or provided data allowing their construction. DATA EXTRACTION Two reviewers screened potential studies for inclusion and independently extracted study data. Methodological quality was assessed by using the QUADAS instrument. DATA SYNTHESIS Of 909 studies identified, 20 (2.2%) met the inclusion criteria. These 20 studies had a median sample size of 33 (range, 16-279) and included 957 patients, predominantly with intermittent claudication (68%). Methodological quality was moderate. Overall, the sensitivity of CTA for detecting more than 50% stenosis or occlusion was 95% (95% confidence interval [CI], 92%-97%) and specificity was 96% (95% CI, 93%-97%). Computed tomography angiography correctly identified occlusions in 94% of segments, the presence of more than 50% stenosis in 87% of segments, and absence of significant stenosis in 96% of segments. Overstaging occurred in 8% of segments and understaging in 15%. CONCLUSION Computed tomography angiography is an accurate modality to assess presence and extent of PAD in patients with intermittent claudication; however, methodological weaknesses of examined studies prevent definitive conclusions from these data.

Meta Analysis on Mortality of Ruptured Abdominal Aortic Aneurysms

OBJECTIVES To assess the mortality of patients with ruptured abdominal aortic aneurysms undergoing open surgery and examine changes in mortality over time. METHODS Literature databases were searched for relevant articles published between 1991 and 2006. Two reviewers independently performed study inclusion and data extraction. Primary outcome measure was 30 day or in-hospital mortality. Subgroup analyses were performed examining the effect of population- and hospital-based studies, hospital volume and type of surgeon. RESULTS From a total of 1419 identified studies, 145 observational studies met the inclusion criteria of which 116 were included in the systematic review comprising 60,822 patients. Overall mortality was 48.5% (95% CI: 48.1-48.9%) and did not change significantly over the years. Age increased over the years. For overall mortality a trend was seen in favour of high-volume hospitals. CONCLUSIONS This meta-analysis suggests that mortality of patients with RAAA treated by open surgery has not changed over the past 15 years. This could be explained by increased age of patients undergoing RAAA repair.

Elective surgery of abdominal aortic aneurysms in octogenarians: a systematic review.

INTRODUCTION Abdominal aortic aneurysm (AAA) is an age-related disease. In an aging population, the prevalence of AAA is likely to increase. Open AAA repair in patients aged >80 years is often not considered because of their advanced age as such or because of comorbidities. In addition, little is known about the natural history in such patients or survival after successful repair. We performed a systematic review of the literature to determine peri-operative and late survival after AAA repair in octogenarians METHOD The Medline, Embase, and Cochrane databases were searched to identify all studies reporting on octogenarians undergoing AAA repair published between January 1966 and June 2006. Two independent observers assessed the methodologic quality of the included studies and the data extraction. Outcomes were rates of perioperative mortality, complications, and long-term survival after open or endovascular repair (EVAR). Summary estimates with 95% confidence interval (CI) were calculated using a random effects model. RESULTS Thirty-nine articles were included. The median aneurysm size was 6.7 cm in the conventional AAA repair group of 1534 patients. The perioperative mortality was 0% to 33%, with a pooled mortality of 7.5% (95% CI, 6.2% to 9.0%). The median 5-year survival rate for this group was 60% (range, 14% to 86%). In the 1045 patients treated with EVAR, the median aneurysm size was 5.9 cm. Their pooled perioperative mortality varied from 0% to 6%, with a pooled mortality of 4.6% (95% CI, 3.4 to 6.0%). We could not derive 5-year survival rates from articles describing endovascular repair of AAA. CONCLUSION The mortality rate after open or endovascular AAA repair in carefully selected octogenarians seems acceptable but is higher than the mortality rate in younger patients. Long-term survival rates were acceptable, but small sample size, selection, and publication bias must be taken into account. Finally, selection criteria for successful surgery with low mortality and morbidity rates cannot be derived from the literature.

Editor's Choice – Endovascular Aneurysm Repair Versus Open Repair for Patients with a Ruptured Abdominal Aortic Aneurysm: A Systematic Review and Meta-analysis of Short-term Survival

BACKGROUND There is clinical equipoise between open (OR) and endovascular aneurysm repair (EVAR) for the best treatment of ruptured abdominal aortic aneurysm (RAAA). OBJECTIVE The aim of the study was to perform a systematic review and meta-analysis to estimate the short-term (combined 30-day or in-hospital) survival after EVAR and OR for patients with RAAA. Data sources included Medline, Embase, and the World Health Organization International Clinical Trials Registry until 13 January 2014. All randomised controlled trials (RCTs), observational cohort studies, and administrative registries comparing OR and EVAR of at least 50 patients were included. Articles were full-length and in English. METHODS Standard PRISMA guidelines were followed. The methodological quality of RCTs was assessed with the Cochrane Collaborations tool for assessing risk of bias. The quality of observational studies was assessed with a modified Cochrane Collaborations tool for assessing risk of bias, the Newcastle-Ottawa Scale, and the Methodological Index for Non-Randomized Studies. The results of the RCTs, of the obersvational studies, and of the administrative registries were pooled separately and analysed with the use of a random effects model. RESULTS From a total of 3,769 articles, three RCTs, 21 observational studies, and eight administrative registries met the inclusion criteria. In the RCTs, the risk of bias was lowest and the pooled odds ratio for death after EVAR versus OR was 0.90 (95% CI 0.65-1.24). The majority of the observational studies had a high risk of bias and the pooled odds ratio for death was 0.44 (95% CI 0.37-0.53). The majority of the administrative registries had a high risk of bias and the pooled odds ratio for death was 0.54 (95% CI 0.47-0.62). CONCLUSION Endovascular aneurysm repair is not inferior to open repair in patients with a ruptured abdominal aortic aneurysm. This supports the use of EVAR in suitable patients and OR as a reasonable alternative.

Can cruropedal colour duplex scanning and pulse generated run-off replace angiography in candidates for distal bypass surgery?*

PURPOSE To compare the diagnostic accuracy of duplex scanning (DS) and pulse generated run-off (PGR) with ia-DSA for the assessment of cruropedal outflow and explore the reliability of clinical decision making based on a work-up with DS/PGR in candidates for peripheral bypass surgery. METHODS Popliteal, crural and pedal arteries were evaluated independently with DS and ia-DSA in 126 limbs of 120 consecutive patients for claudication (16%) or critical ischaemia (84%). Arterial segments were graded with DS and ia-DSA as normal, stenosed, or occluded and compared using weighted kappa (kappa) analysis. PGR was used to select the best crural artery for bypass. Proposed management based on DS/PGR and, if applicable, anastomosis site were compared to definitive treatment based on ia-DSA. RESULTS Overall agreement between DS and ia-DSA for popliteal and crural arteries was moderate (kappa 0.51, 95% CI 0.48-0.55) with good agreement within the popliteal (kappa 0.67) and anterior tibial (kappa 0.61) arteries. Agreement was moderate within the pedal arterieds (kappa 0.32, 95% CI 0.24-0.40). In 74/126 (59%) limbs proposed management with DS/PGR was identical to ia-DSA. In 23/29 (79%) femoropopliteal and 15/37 (41%) femorocrural bypasses DS/PGR agreed perfectly with ia-DSA with regard to acceptor artery and anastomosis site. CONCLUSION DS can accurately assess the popliteal and anterior tibial arteries. In a substantial number of patients with severe lower limb ischaemia decisions for conservative management, PTA and femoropopliteal bypass can be based on a DS/PGR work-up.

The AMC Linear Disability Score (ALDS): a cross-sectional study with a new generic instrument to measure disability applied to patients with peripheral arterial disease

BackgroundThe AMC Linear Disability Score (ALDS) is a calibrated generic itembank to measure the level of physical disability in patients with chronic diseases. The ALDS has already been validated in different patient populations suffering from chronic diseases. The aim of this study was to assess the clinimetric properties of the ALDS in patients with peripheral arterial disease.MethodsPatients with intermittent claudication (IC) and critical limb ischemia (CLI) presenting from January 2007 through November 2007 were included. Risk factors for atherosclerosis, ankle/brachial index and toe pressure, the Vascular Quality of Life Questionnaire (VascuQol), and the ALDS were recorded. To compare ALDS and VascuQol scores between the two patient groups, an unpaired t-test was used. Correlations were determined between VascuQol, ALDS and pressure measurements.ResultsSixty-two patients were included (44 male, mean ± sd age was 68 ± 11 years) with IC (n = 26) and CLI (n = 36). The average ALDS was significantly higher in patients with IC (80, ± 10) compared to patients with CLI (64, ± 18). Internal reliability consistency of the ALDS expressed as Cronbachs α coefficient was excellent (α > 0.90). There was a strong convergent correlation between the ALDS and the disability related Activity domain of the VascuQol (r = 0.64).ConclusionThe ALDS is a promising clinimetric instrument to measure disability in patients with various stages of peripheral arterial disease.

Statistical or clinical improvement? Determining the minimally important difference for the vascular quality of life questionnaire in patients with critical limb ischemia.

OBJECTIVE Interpreting whether changes in quality of life (Qol) in patients with peripheral arterial disease (PAD) are not only statistically significant but also clinically relevant, may be difficult. This study introduces the concept of the minimally important difference (MID) to vascular surgeons using Qol outcomes of patients treated for chronic critical limb ischemia (CLI). METHODS The Vascular Quality of Life (VascuQol) questionnaire was recorded at baseline before treatment and after 6 months follow-up in consecutive patients with CLI treated between May 2007 and May 2010. Statistical significance of change in VascuQol score was tested with the Wilcoxon Signed Rank test. The MID for the VascuQol score was determined using a clinical anchor-based method and a distribution-based method. RESULTS A total of 127 patients with CLI completed the VascuQol after 6 months. The VascuQol sum scores improved from 3.0 (range 1.1-5.9) at baseline to 4.0 (range 1.2-6.7) at 6 months (p < .001). The MID on the VascuQol sumscore indicating a clinically important change determined with the anchor-based method was 0.36, and with the distribution-based method was 0.48. On an individual level, depending on the method of determining the MID, this resulted in 60% to 68% of the patients with an important benefit. CONCLUSIONS Expression of changes in Qol by means of the MID provides better insight into clinically important changes than statistical significance.

Changes in functional status after treatment of critical limb ischemia

OBJECTIVE This study evaluated changes in functional status with the Academic Medical Center Linear Disability Score (ALDS) and in quality of life with the Vascular Quality of Life Questionnaire (VascuQol) in patients treated for critical limb ischemia (CLI). METHODS We conducted a prospective observational cohort study in a single academic center that included consecutive patients with CLI who presented between May 2007 and May 2010. The ALDS and VascuQol questionnaires were administered before treatment (baseline) and after treatment at 6 and 12 months of follow-up. Changes in functional status (ALDS) and quality of life (VascuQol) scores after 6 and 12 months, compared with baseline, were tested with the appropriate statistical tests, with significance set at P < .05. RESULTS The study included 150 patients, 96 (64%) were men, and mean (± standard deviation) age was 68.1 (± 12.4) years. The primary treatment was endovascular in 98 (65.3%), surgical in 36 (24%), conservative in 11 (7.3%), or a major amputation in five (3.3%). The ALDS was completed by 112 patients after 12 months. At that time, the median ALDS score had increased by 10 points (median, 83; range, 12-89; P = .001) in patients who achieved limb salvage, which corresponds with more difficult outdoor and indoor activities. In patients with a major amputation, the median ALDS score decreased by 14 points (median, 55; range, 16-89; P = .117) after 12 months, which corresponds with domestic activities only. VascuQol scores improved significantly in all separate domains for the limb salvage group (P < .001). All VascuQol scores, except for the activity and social domains, increased significantly after amputation. CONCLUSIONS Our study confirms the clinical validity of the ALDS in patients treated for CLI and shows that it is a valuable and sophisticated instrument to measure changes in functional status in these patients.

Hyperbaric Oxygen Therapy in the Treatment of Ischemic Lower- Extremity Ulcers in Patients With Diabetes: Results of the DAMO2CLES Multicenter Randomized Clinical Trial

OBJECTIVE Conflicting evidence exists on the effects of hyperbaric oxygen therapy (HBOT) in the treatment of chronic ischemic leg ulcers. The aim of this trial was to investigate whether additional HBOT would benefit patients with diabetes and ischemic leg ulcers. RESEARCH DESIGN AND METHODS Patients with diabetes with an ischemic wound (n = 120) were randomized to standard care (SC) without or with HBOT (SC+HBOT). Primary outcomes were limb salvage and wound healing after 12 months, as well as time to wound healing. Other end points were amputation-free survival (AFS) and mortality. RESULTS Both groups contained 60 patients. Limb salvage was achieved in 47 patients in the SC group vs. 53 patients in the SC+HBOT group (risk difference [RD] 10% [95% CI −4 to 23]). After 12 months, 28 index wounds were healed in the SC group vs. 30 in the SC+HBOT group (RD 3% [95% CI −14 to 21]). AFS was achieved in 41 patients in the SC group and 49 patients in the SC+HBOT group (RD 13% [95% CI −2 to 28]). In the SC+HBOT group, 21 patients (35%) were unable to complete the HBOT protocol as planned. Those who did had significantly fewer major amputations and higher AFS (RD for AFS 26% [95% CI 10–38]). CONCLUSIONS Additional HBOT did not significantly improve complete wound healing or limb salvage in patients with diabetes and lower-limb ischemia.

Biomechanical Imaging Markers as Predictors of Abdominal Aortic Aneurysm Growth or Rupture: A Systematic Review

OBJECTIVES Biomechanical characteristics, such as wall stress, are important in the pathogenesis of abdominal aortic aneurysms (AAA) and can be visualised and quantified using imaging techniques. This systematic review aims to present an overview of all biomechanical imaging markers that have been studied in relation to AAA growth and rupture. METHODS This systematic review followed the PRISMA guidelines. A search in Medline, Embase, and the Cochrane Library identified 1503 potentially relevant articles. Studies were included if they assessed biomechanical imaging markers and their potential association with growth or rupture. RESULTS Twenty-seven articles comprising 1730 patients met the inclusion criteria. Eighteen studies performed wall stress analysis using finite element analysis (FEA), 13 of which used peak wall stress (PWS) to quantify wall stress. Ten of 13 case control FEA studies reported a significantly higher PWS for symptomatic or ruptured AAAs than for intact AAAs. However, in some studies there was confounding bias because of baseline differences in aneurysm diameter between groups. Clinical heterogeneity in methodology obstructed a meaningful meta-analysis of PWS. Three of five FEA studies reported a significant positive association between several wall stress markers, such as PWS and 99th percentile stress, and growth. One study reported a significant negative association and one other study reported no significant association. Studies assessing wall compliance, the augmentation index and wall stress analysis using Laplaces law, computational fluid dynamics and fluid structure interaction were also included in this systematic review. CONCLUSIONS Although PWS is significantly higher in symptomatic or ruptured AAAs in most FEA studies, confounding bias, clinical heterogeneity, and lack of standardisation limit the interpretation and generalisability of the results. Also, there is conflicting evidence on whether increased wall stress is associated with growth.