Assessment of Carotid Plaque Inflammation in Diabetic and Nondiabetic Patients-An Exploratory Ultrasmall Superparamagnetic Iron Oxide-Enhanced Magnetic Resonance Imaging Study.

BACKGROUND: Ultrasmall superparamagnetic iron oxide (USPIO)-enhanced magnetic resonance (MR) imaging enables the identification of inflammation within the atheroma, predominantly by USPIO uptake by macrophages present in atherosclerotic tissue. Diabetic patients, however, may have dysfunctional macrophage activity, which may affect utilization of USPIO in identifying plaque inflammation in this patient cohort. METHODS: Fifteen diabetic and fifteen nondiabetic patients underwent USPIO-enhanced carotid MR imaging using 1.5T MR system. Pre- and post-USPIO carotid MR images were manually coregistered. The percentage decrease in the signal intensity after USPIO administration was calculated as a relative measure of the USPIO uptake. RESULTS: Diabetic and nondiabetic patients had comparable demographics and comorbidities. The mean global, maximum quadrant, and maximum slice changes showing change in relative signal intensity as a result of USPIO administration were comparable for the two patient cohorts (P > .05). CONCLUSIONS: USPIO can identify inflammatory burden with carotid atheroma in both diabetic and nondiabetic patients.

Assessment of Renal Injury in Patients Undergoing Elective EVAR Using Urinary Neutrophil Gelatin-Associated Lipocalin, Interleukin 18, and Retinol-Binding Protein.

Acute kidney injury (AKI) is a recognized complication post-endovascular aneurysm repair (EVAR). Neutrophil gelatin-associated lipocalin (NGAL), interleukin 18 (IL-18), and retinol-binding protein are emerging urinary biomarkers that have shown promise in detecting subclinical and clinical renal impairment. In this study, we assessed changes in these urinary biomarkers as well as serum creatinine (SCr) in patients undergoing EVAR. Urine samples were collected prospectively at 5 time points for each recruited patient: pre-EVAR (baseline) and 6, 12, 24, and 48 hours after the procedure for serial assessment of urinary biomarkers. Serum creatinine was quantified preoperatively and at 24 and 48 hours postoperatively. Serial changes of urinary biomarkers and SCr were assessed. A significant increase in NGAL and IL-18 from baseline was observed ( P < .05), as early as 6 hours for NGAL. A significant rise in levels of NGAL and IL-18 precedes the significant rise in SCr. These findings highlight the potential of emerging urinary biomarkers in detecting early AKI following EVAR.

Cost-effectiveness analysis of endovascular versus open surgical repair of acute abdominal aortic aneurysms based on worldwide experience.

PURPOSE: To present an economic evaluation of endovascular versus open surgical repair of ruptured abdominal aortic aneurysms (AAA). METHODS: Endovascular aneurysm repair (EVAR) is currently being appraised by the National Institute for Clinical Excellence. To aid in this appraisal, a health economic model developed to demonstrate the cost-effectiveness of EVAR for elective treatment of non-ruptured AAAs versus OSR was used for an analysis in the emergency setting. The base case data on 730 patients undergoing EVAR was extracted from our recently published 22-study meta-analysis of 7040 patients presenting with acute AAA (ruptured or symptomatic) treated with either emergency EVAR or OSR. These data reflected a patient population with an average age of 70 years. The base case model, which assumed a time horizon of 30 years and applied all-cause mortality rates, was subjected to a number of 1-way sensitivity analyses. A multivariate analysis was undertaken using 10,000 Monte-Carlo simulations. RESULTS: EVAR dominated OSR in the base case analysis, with a mean cumulative cost/patient of pound17,422 ($26,133) for EVAR and pound18,930 ($28,395) for OSR [- pound1508 ($2262) difference]. The mean quality-adjusted life years (QALYs)/patient was 3.09 for EVAR versus 2.49 for OSR (0.64 difference). EVAR was cost-effective compared with OSR at a threshold value of pound20,000 to pound30,000 ($30,000-$45,000)/QALY. In no single combination tested did open surgical repair provide the patient with more QALYs than EVAR. Sensitivity analyses demonstrated that the results were most sensitive to length of hospital and intensive care stays, use of blood products, and the cost of the evar device, which were the main cost drivers. CONCLUSION: While the UK's National Institute for Clinical Excellence does not set an absolute limit at which treatments would not be funded, pound30,000 ($45,000) is generally regarded as the upper limit of acceptability. At this level, there is almost a 100% probability that EVAR is a cost-effective treatment for ruptured AAA.

Identification and assessment of plasma lysozyme as a putative biomarker of atherosclerosis.

OBJECTIVE: To identify a plasma biomarker of atheromatous disease. METHODS AND RESULTS: Surface-enhanced laser desorption ionization-time-of-flight mass spectrometry was used to identify possible plasma protein biomarkers of atheromatous disease in patients presenting with chronic stable angina pectoris by comparing those with 3-vessel disease with those without any evidence of coronary artery disease. The level of a 14.7-kDa protein was elevated; this protein was isolated and identified as a lysozyme. Arterial plasma lysozyme levels, measured by immunoassay, confirmed this observation in separate cohorts of patients. The application of arterial plasma lysozyme levels to 197 patients with varying degrees of coronary artery disease, using a cutoff value of 1.5 microg/mL, was able to distinguish patients with 1 or more occluded coronary arteries, with 86% sensitivity and 93% specificity. Of 20 patients with carotid atheroma, 19 had increased arterial plasma levels. In contrast, C-reactive protein levels showed no association with disease severity. Venous lysozyme levels in patients with carotid atheroma were shown to decrease after intensive atorvastatin treatment. CONCLUSION: Raised plasma lysozyme levels may be a useful biomarker of atherosclerotic cardiovascular disease and response to therapy. Additional studies to investigate this are warranted.

Great saphenous vein harvesting: a systematic review and meta-analysis of open versus endoscopic techniques.

BACKGROUND: The great saphenous vein is frequently harvested for use as a conduit in lower limb bypass surgery. A number of papers advocate the use of an endoscopic technique rather than a traditional open technique to minimize the associated morbidity. We undertook a systematic review and meta-analysis to compare morbidity associated with these 2 techniques. METHOD: Medline, PubMed, and secondary referencing identified 16 randomized control trials comparing these 2 methods of harvesting. Primary outcome measures were infection, hematoma, and wound dehiscence and pooled odds ratios (POR) were calculated using a random effects model. RESULTS: Sixteen trials (3689 patients) were identified. Overall complications (POR 7.03), infection (POR 8.08), and wound dehiscence (POR 8.23) were all significantly more common in the open harvesting group compared to the endoscopic group. CONCLUSION: Endoscopic techniques have a role in vein harvesting but are operator dependent and therefore are only a preferable modality compared to open harvesting methods in experienced hands. More research is required to establish whether long-term patency rates are comparable for the 2 techniques.

Assessment of a multifactorial risk index for predicting postoperative pneumonia after open abdominal aortic aneurysm repair.

Pneumonia is a common postoperative complication, with a mortality of up to 40%. The Post-operative Pneumonia Risk Index (PPRI) was derived from a large cohort of general surgical patients but has not been validated in patients undergoing open abdominal aortic aneurysm (AAA) repair. The PPRI was applied to patients undergoing elective open AAA repair in a tertiary referral vascular unit. Pneumonia occurred in 20% of patients. Receiver operating characteristic curve analysis identified 36 as the optimum PPRI cutoff value. At this cutoff, the likelihood ratio for pneumonia was 1.35 (95% confidence interval 1.08-1.62). However, in a multivariate analysis, only weight loss in excess of 10% over the preceding 6 months was an independent predictor of postoperative pneumonia. Although the PPRI is of some value in identifying high-risk patients undergoing AAA repair, weight loss alone may be predictive, allowing targeted preventive measures in aneurysm patients at increased risk.

The future of EVAR in the management of ruptured AAAs.

Endovascular repair of ruptured abdominal aortic aneurysms is an evolving technique. Data from nonrandomized series suggest that it may be beneficial in selected patients. In the next few years, a number of large randomized clinical trials will clarify its role. Issues regarding anatomical suitability, techniques, perioperative care, and service provision need to be addressed in order to optimize outcomes.

Continuous wound infusion of local anaesthetic agents following colorectal surgery: systematic review and meta-analysis.

AIM: To provide a specific review and meta-analysis of the available evidence for continuous wound infusion of local anaesthetic agents following midline laparotomy for major colorectal surgery. METHODS: Medline, Embase, trial registries, conference proceedings and article reference lists were searched to identify randomised, controlled trials of continuous wound infusion of local anaesthetic agents following colorectal surgery. The primary outcomes were opioid consumption, pain visual analogue scores (VASs), return to bowel function and length of hospital stay. Weighted mean difference were calculated for continuous outcomes. RESULTS: Five trials containing 542 laparotomy wounds were eligible for inclusion. There was a significant decrease in post-operative pain VAS at rest on day 3 (weighted mean difference: -0.43; 95% CI: -0.81 to -0.04; P = 0.03) but not on post-operative day 1 and 2. Local anaesthetic infusion was associated with a significant reduction in pain VAS on movement on all three post-operative days (day 1 weighted mean difference: -1.14; 95% CI: -2.24 to -0.041; P = 0.04, day 2 weighted mean difference: -0.97, 95% CI: -1.91 to -0.029; P = 0.04, day 3 weighted mean difference: -0.61; 95% CI: 1.01 to -0.20; P = 0.0038). Local anaesthetic wound infusion was associated with a significant decrease in total opioid consumption (weighted mean difference: -40.13; 95% CI: -76.74 to -3.53; P = 0.03). There was no significant decrease in length of stay (weighted mean difference: -20.87; 95% CI: -46.96 to 5.21; P = 0.12) or return of bowel function (weighted mean difference: -9.40; 95% CI: -33.98 to 15.17; P = 0.45). CONCLUSION: The results of this systematic review and meta-analysis suggest that local anaesthetic wound infusion following laparotomy for major colorectal surgery is a promising technique but do not provide conclusive evidence of benefit. Further research is required including cost-effectiveness analysis.

In vivo positive contrast IRON sequence and quantitative T(2)* measurement confirms inflammatory burden in a patient with asymptomatic carotid atheroma after USPIO-enhanced MR imaging.

The authors report an in vivo human examination of carotid atheroma by using the inversion-recovery ON resonance (IRON) sequence, which is able to produce positive contrast after the infusion of an ultrasmall super paramagnetic iron oxide (USPIO) contrast medium. This technique provides a method of potentially identifying inflammatory burden within carotid atheroma. This may be particularly useful in patients who currently do not meet criteria for intervention (ie, moderate symptomatic stenosis or <70% asymptomatic stenosis) to further risk-stratify this important patient cohort. A 63-year-old man was imaged at 1.5 T before and 36 hours after USPIO infusion by using the IRON sequence. Regions of interest showing profound signal loss at T(2)*-weighted imaging corresponded well with regions of positive contrast at IRON imaging after the administration of USPIO. These regions also showed a profound decrease in T(2)* measurements after USPIO infusion, whereas surrounding tissue did not. It has been shown that such strong signal loss on T(2)*-weighted images after USPIO infusion is indicative of USPIO uptake.

Efficacy of closed suction drainage in lower limb arterial surgery: a meta-analysis of published clinical trials.

BACKGROUND: Suction drains are widely used in vascular surgery, despite the absence of specific evidence that they confer benefit to patients. There has been no systematic review of the available evidence, though drainage has been shown to confer no benefit, or indeed harm, across a variety of surgical disciplines. Accordingly, a systematic review and meta-analysis of the current evidence base for closed suction drainage following surgical lower limb revascularization was undertaken. METHODS: Medline, Embase, trial registries, conference proceedings, and article reference lists were searched to identify randomized controlled trials of the use of surgical drains. The primary outcomes were wound infection, seroma/lymphocele formation, and hematoma formation. Pooled odds ratios were calculated for categorical outcomes. RESULTS: Four trials containing 429 groin wounds were eligible for inclusion. There was no significant effect on wound infection, seroma/lymphocele formation, or hematoma formation. CONCLUSION: Our meta-analysis suggests that no benefit is conferred by wound drainage following lower limb revascularization. The practice incurs avoidable expense and should not be routinely used.