M. Clarke Moloney

A MultiCenter Pilot Randomized Controlled Trial of Remote Ischemic Preconditioning in Major Vascular Surgery.

A pilot randomized controlled trial that evaluated the effect of remote ischemic preconditioning (RIPC) on clinical outcomes following major vascular surgery was performed. Eligible patients were those scheduled to undergo open abdominal aortic aneurysm repair, endovascular aortic aneurysm repair, carotid endarterectomy, and lower limb revascularization procedures. Patients were randomized to RIPC or to control groups. The primary outcome was a composite clinical end point comprising any of cardiovascular death, myocardial infarction, new-onset arrhythmia, cardiac arrest, congestive cardiac failure, cerebrovascular accident, renal failure requiring renal replacement therapy, mesenteric ischemia, and urgent cardiac revascularization. Secondary outcomes were components of the primary outcome and myocardial injury as assessed by serum troponin values. The primary outcome occurred in 19 (19.2%) of 99 controls and 14 (14.1%) of 99 RIPC group patients (P = .446). There were no significant differences in secondary outcomes. Our trial generated data that will guide future trials. Further trials are urgently needed.

A comparison of fibrin sealant versus standard closure in the reduction of postoperative morbidity after groin dissection: A systematic review and meta-analysis

BACKGROUND Groin dissection is commonly performed in patients with lower limb malignant conditions such as malignant melanoma, vulvar, penile, anal and scrotal carcinomas with an associated high complication rate. Numerous surgical strategies have been suggested to reduce morbidity. We aimed to systematically review one of those methods - fibrin sealant (FS) - in comparison to standard closure (SC) in reducing postoperative morbidity from groin dissection. METHODS A systematic search of the literature, study selection and data extraction using an independent screening process, assessment of risk of bias and statistical data analysis was performed. Only randomised controlled trials (RCTs) comparing fibrin sealant to standard care in patients with malignant disease undergoing groin dissection reporting at least one outcome measure relating to postoperative complications were included in the review. RESULTS A total of 6 RCTs were included. There were no statistically significant differences in postoperative surgical site infection (SSI) rates between FS and SC. The overall incidence of wound infection in the FS group was 32% (43/133) compared to 34% (45/132) in the SC group. (Pooled risk ratio = 0.0.94 [0.68, 1.32]; 95% CI; P = 0.74). The incidence of seroma for the FS group (30/133) and the SC group (30/132) did not differ (Pooled risk ratio = 1.03 [0.67, 1.58]; 95% CI; P value = 0.90). Complication rates were similar between groups. CONCLUSION Based on current evidence, fibrin sealant does not significantly reduce morbidity in patients undergoing groin dissection for the management of malignant disease when compared to standard closure techniques.

The role of venous diameter in predicting arteriovenous fistula maturation: When not to expect an AVF to mature according to pre-operative vein diameter measurements? A best evidence topic

This best evidence topic was investigated according to a described protocol. We asked the question: what is the minimal vein diameter that can successfully predict maturation of an arteriovenous fistula (AVF) in patients undergoing dialysis. Using the reported search 804 papers were found, of which five represented the best evidence to answer the clinical question. All studies assessed the association between successful AVF maturation and the size of vein used. The strongest evidence came from a nonrandomised controlled follow-up study in which 76% of fistulas created using >2 mm cephalic vein successfully matured compared to 16% when the vein measured ≤2 mm. Another prospective, multicentre study showed 65% successful maturation using veins >4 mm compared to 45% with veins <3 mm. Vein diameter was found to be an independent predictor of maturation in multivariate regression analysis in two retrospective observational studies. Another retrospective observational study found that using venous measurements of ≥2.5 mm following tourniquet application resulted in more fistulas been created that would have otherwise been denied based on venous ultrasound mapping. A large multicentre randomised clinical trial assessing the use of different vein sizes both with and without tourniquet application using proper statistical tools - such as receiver operating characteristic - is required to make a final recommendation. Until then, a vein diameter of <2.5 mm should be considered inadequate for formation of an AVF, particularly if those measurements remain unchanged following the use of tourniquet.

Diagnostic accuracy of non-radiologist performed ultrasound for abdominal aortic aneurysm: systematic review and meta-analysis

Ultrasonography is increasingly used by clinicians to identify abdominal aortic aneurysms (AAA). We performed a systematic review and meta‐analysis comparing the accuracy of non‐radiologist performed ultrasound (NRPUS) for AAA disease to the ‘gold standard’ of radiologist performed aortic imaging (RPI), intra‐operative findings or postmortem findings.

Contrast-enhanced magnetic resonance angiography in diabetic patients with infra-genicular peripheral arterial disease: Systematic review

OBJECTIVE Diabetes is a leading risk factor for the development of peripheral arterial disease (PAD). The optimal imaging modality for patients with diabetes and PAD is uncertain. We sought to analyse the literature to determine the accuracy of contrast enhanced magnetic resonance angiography (CE-MRA) in differentiating extent of disease in patients with infragenicular PAD and diabetes, using digital subtraction angiography (DSA) as the gold standard. METHODS Online databases were searched for relevant keywords (January 1998-June 2012). Eligible studies prospectively compared CE-MRA and DSA of infragenicular vessels and provided data to construct contingency tables in at least 10 patients with diabetes and PAD symptoms. Pooled sensitivity and specificity values were calculated using random effects modelling. RESULTS Only three studies (83 patients) provided data regarding the infragenicular vessels. The pooled sensitivity of MRA was 86% while the pooled specificity of MRA was 93%. CONCLUSIONS The assumptions regarding CE-MRAs efficacy for infragenicular disease in diabetics are based upon low patient numbers. Inadequate diagnostic imaging in this high-risk group risks adoption of incorrect revascularisation strategies. Further studies are required.