The Berrettini palmar neural communicating branch: a study of 27 cadaveric specimens and determination of a high-risk surgical zone.

In this cadaveric study, we analysed digital images of dissected palms to define the location and length of superficial connections between the median and the ulnar nerves (Berrettini communicating branches). We found the connections present in 12 of 27 hands. We used a coordinate model to define their location relative to seven specified landmarks. The model revealed that the Berrettini communicating branches were positioned consistently, and we defined a high-risk zone in the palm that fully contained seven of the 12 connections, while others had minor projections outside the zone. We conclude that awareness of this high-risk zone in the palm can be of some help to reduce the risk of iatrogenic nerve injury, however, any operation in the palm must always be done with great care to visualize and protect any possible anatomically unusual structures.

Remote ischemic preconditioning in major vascular surgery.

Remote ischemic preconditioning is a physiologic mechanism in mammalian species whereby brief exposure to nonlethal ischemia in one tissue confers protection against a prolonged ischemic insult in a distant tissue. First described almost 15 years ago, it has been slow to translate into clinical practice. Several clinical trials have recently reported that remote ischemic preconditioning reduces myocardial injury after major cardiovascular surgery. In addition, a randomized trial in patients undergoing open abdominal aortic aneurysm repair reported a significant reduction in perioperative myocardial infarctions. Remote ischemic preconditioning is easily performed and likely to prove highly cost-effective. large-scale trials of the technique are warranted in patients undergoing major vascular surgery.

Remote ischemic preconditioning for renal and cardiac protection during endovascular aneurysm repair: a randomized controlled trial.

PURPOSE: To report a randomized clinical trial designed to determine if remote ischemic preconditioning (IP) has the ability to reduce renal and cardiac damage following endovascular aneurysm repair (EVAR). METHODS: Forty patients (all men; mean age 76+/-7 years) with abdominal aortic aneurysms averaging 6.3+/-0.8 cm in diameter were enrolled in the trial from November 2006 to January 2008. Eighteen patients (mean age 74 years, range 72-81) were randomized to preconditioning and completed the full remote IP protocol; there were no withdrawals. Twenty-two patients (mean age 76 years, range 66-80) were assigned to the control group. Remote IP was induced using sequential lower limb ischemia. Serum and urinary markers of renal and cardiac injury were compared between the groups. RESULTS: Urinary retinol binding protein (RBP) levels increased 10-fold from a median of 235 micromol/L to 2356 micromol/L at 24 hours (p = 0.0001). There was a lower increase in the preconditioned group, from 167 micromol/L to 413 micromol/L at 24 hours (p = 0.04). The median urinary albumin:creatinine ratio was significantly lower in the preconditioned group at 24 hours (5 versus 8.8, p = 0.06). There were no differences in the rates of renal impairment or major adverse cardiac events. CONCLUSION: Remote preconditioning reduces urinary biomarkers of renal injury in patients undergoing elective EVAR. This small pilot trial was unable to detect an effect on clinical endpoints; further trials are warranted.

Remote ischemic preconditioning reduces myocardial and renal injury after elective abdominal aortic aneurysm repair: a randomized controlled trial.

BACKGROUND: Myocardial and renal injury commonly contribute to perioperative morbidity and mortality after abdominal aortic aneurysm repair. Remote ischemic preconditioning (RIPC) is a phenomenon whereby brief periods of ischemia followed by reperfusion in one organ provide systemic protection from prolonged ischemia. To investigate whether remote preconditioning reduces the incidence of myocardial and renal injury in patients undergoing elective open abdominal aortic aneurysm repair, we performed a randomized trial. METHOD AND RESULTS; Eighty-two patients were randomized to abdominal aortic aneurysm repair with RIPC or conventional abdominal aortic aneurysm repair (control). Two cycles of intermittent crossclamping of the common iliac artery with 10 minutes ischemia followed by 10 minutes reperfusion served as the RIPC stimulus. Myocardial injury was assessed by cardiac troponin I (>0.40 ng/mL), myocardial infarction by the American College of Cardiology/American Heart Association definition and renal injury by serum creatinine (>177 micromol/L) according to American Heart Association guidelines for risk stratification in major vascular surgery. The groups were well matched for baseline characteristics. RIPC reduced the incidence of myocardial injury by 27% (39% versus 12% [95% CI: 8.8% to 45%]; P=0.005), myocardial infarction by 22% (27% versus 5% [95% CI: 7.3% to 38%]; P=0.006), and renal impairment by 23% (30% versus 7%; [95% CI: 6.4 to 39]; P=0.009). Multivariable analysis revealed the protective effect of RIPC on myocardial injury (OR: 0.22, 95% CI: 0.07 to 0.67; P=0.008), myocardial infarction (OR: 0.18, 95% CI: 0.04 to 0.75; P=0.006) and renal impairment were independent of other covariables. CONCLUSIONS: In patients undergoing elective open abdominal aortic aneurysm repair, RIPC reduces the incidence of postoperative myocardial injury, myocardial infarction, and renal impairment.

Correlation of carotid atheromatous plaque inflammation using USPIO-enhanced MR imaging with degree of luminal stenosis.

BACKGROUND AND PURPOSE: Inflammation is a recognized risk factor for the vulnerable atherosclerotic plaque. The study explores the relationship between the degree of Magnetic Resonance (MR)-defined inflammation using Ultra Small Super-Paramagnetic Iron Oxide (USPIO) particles and the severity of luminal stenosis in asymptomatic carotid plaques. METHODS: Seventy-one patients with an asymptomatic carotid stenosis of > or = 40% underwent multi-sequence USPIO-enhanced MR imaging. Stenosis severity was measured according to the NASCET and ECST methods. RESULTS: No demonstrable relationship between inflammation as measured by USPIO-enhanced signal change and the degree of luminal stenosis was found. CONCLUSIONS: Inflammation and stenosis are likely to be independent risk factors, although this needs to be further validated.

Role of carotid duplex imaging in carotid screening programmes - an overview.

BACKGROUND: Stroke is the third most common cause of death in the UK and the largest single cause of severe disability. Each year more than 110,000 people in England suffer from a stroke which costs the National Health Service (NHS) over GBP2.8 billion. Thus, it is imperative that patients at risk be screened for underlying carotid artery atherosclerosis. AIM: To assess the role of carotid ultrasound in different carotid screening programmes. METHODS: A literature overview was carried out by using PubMed search engine, to identify different carotid screening programmes that had used ultrasound scan as a screening tool. RESULTS: It appears that the carotid ultrasound is an effective method for screening carotid artery disease in community as it effectively predicts the presence of stenosis with high accuracy. There is a need for primary care to recommend high risk patients for regular screening, to reduce stroke and transient ischemic attack (TIA) related morbidity and mortality. CONCLUSION: Screening programmes using carotid ultrasonography contribute to public health awareness and promotion which in long term could potentially benefit in disease prevention and essentially promote better standards of healthcare.

Comparison of the inflammatory burden of truly asymptomatic carotid atheroma with atherosclerotic plaques contralateral to symptomatic carotid stenosis: an ultra small superparamagnetic iron oxide enhanced magnetic resonance study.

BACKGROUND: Inflammation is a recognised risk factor for the vulnerable atherosclerotic plaque. The aim of this study was to explore whether there is a difference in the degree of magnetic resonance (MR) defined inflammation using ultra small superparamagnetic iron oxide (USPIO) particles within carotid atheroma in completely asymptomatic individuals and the asymptomatic carotid stenosis contralateral to the symptomatic side. METHODS: 20 symptomatic patients with contralateral disease and 20 completely asymptomatic patients underwent multi-sequence MR imaging before and 36 h after USPIO infusion. Images were manually segmented into quadrants and signal change in each quadrant was calculated following USPIO administration. Mean signal change was compared across all quadrants in the two groups. RESULTS: The mean percentage of quadrants showing signal loss was 53% in the contralateral group compared with 31% in completely asymptomatic individuals (p = 0.025). The mean percentages showing enhancement were 44% and 65%, respectively (p = 0.024). The mean signal difference between the two groups was 8.6% (95% CI 1.6% to 15.6%; p = 0.017). CONCLUSIONS: Truly asymptomatic plaques seem to demonstrate inflammation but not to the extent of the contralateral asymptomatic stenosis to the symptomatic side. Inflammatory activity may be a significant risk factor in asymptomatic disease.

Preoperative glomerular filtration rate and outcome following open abdominal aortic aneurysm repair.

Estimated glomerular filtration rate (eGFR) can be readily calculated from serum creatinine values. It is a more sensitive prognostic indicator than serum creatinine alone in patients undergoing thoracoabdominal or endovascular abdominal aortic aneurysm repair. The value of eGFR in patients undergoing open abdominal aortic aneurysm repair remains unclear. The preoperative eGFR was calculated for patients undergoing elective open infrarenal aortic aneurysm repair. Postoperative complications, perioperative mortality, and long-term survival were compared across eGFR and serum creatinine quartiles. The eGFR identified preoperative renal dysfunction in 33% of patients, whereas serum creatinine identified renal impairment in only 11%. The eGFR correlated with perioperative morbidity and long-term survival. Serum creatinine did not correlate with perioperative mortality or long-term survival. However, it did correlate with postoperative morbidity. The eGFR is a more sensitive index of preoperative renal function than serum creatinine and correlates with survival. It should replace serum creatinine as the standard index of renal function before open abdominal aortic aneurysm repair.

Assessment of inflammatory burden contralateral to the symptomatic carotid stenosis using high-resolution ultrasmall, superparamagnetic iron oxide-enhanced MRI.

BACKGROUND AND PURPOSE: It is well known that the vulnerable atheromatous plaque has a thin, fibrous cap and large lipid core with associated inflammation. This inflammation can be detected on MRI with use of a contrast medium, Sinerem, an ultrasmall superparamagnetic iron oxide (USPIO). Although the incidence of macrophage activity in asymptomatic disease appears low, we aimed to explore the incidence of MRI-defined inflammation in asymptomatic plaques in patients with known contralateral symptomatic disease. METHODS: Twenty symptomatic patients underwent multisequence MRI before and 36 hours after USPIO infusion. Images were manually segmented into quadrants, and the signal change in each quadrant was calculated after USPIO administration. A mixed mathematical model was developed to compare the mean signal change across all quadrants in the 2 groups. Patients had a mean symptomatic stenosis of 77% compared with 46% on their asymptomatic side, as measured by conventional angiography. RESULTS: There were 11 (55%) men, and the median age was 72 years (range, 53 to 84 years). All patients had risk factors consistent with severe atherosclerotic disease. All symptomatic carotid stenoses had inflammation, as evaluated by USPIO-enhanced imaging. On the contralateral sides, inflammatory activity was found in 19 (95%) patients. Contralaterally, there were 163 quadrants (57%) with a signal loss after USPIO when compared with 217 quadrants (71%) on the symptomatic side (P=0.007). CONCLUSIONS: This study adds weight to the argument that atherosclerosis is a truly systemic disease. It suggests that investigation of the contralateral side in patients with symptomatic carotid stenosis can demonstrate inflammation in 95% of plaques, despite a mean stenosis of only 46%. Thus, inflammatory activity may be a significant risk factor in asymptomatic disease in patients who have known contralateral symptomatic disease. Patients with symptomatic carotid disease should have their contralateral carotid artery followed up.

The radiation burden from increasingly complex endovascular aortic aneurysm repair.

OBJECTIVES: With increasing experience, endovascular aortic aneurysm repair (EVAR) has been extended to patients with less suitable aorto-iliac anatomy in an attempt to reduce peri-operative mortality. However, more complex EVAR procedures may take longer and can result in higher rates of complications, additional interventional procedures and more frequent radiological imaging, which may offset some of the benefit. This study determined the radiation burden for standard EVAR, as determined by the EVAR-1 trial criteria, and more complex EVAR. METHODS: A total of 123 elective patients aged >60, with aneurysms >5.5 cm who received a bifurcated stent-graft were allocated into a group based on whether or not they fulfilled strict EVAR-1 trial criteria. The mean radiation dose was calculated for each group, together with the additional radiation burden from routine pre- and post-EVAR CT examinations and pre-EVAR iliac artery embolisation. RESULTS: Patients not meeting the EVAR-1 trial criteria had significantly longer fluoroscopic screening times and higher radiation doses. The radiation burden in all patients was higher following exposure from routine CT examinations and following pre-EVAR iliac artery embolisation. CONCLUSION: Whilst the radiation from standard EVAR is acceptable, more complicated and challenging EVARs, accompanied with additional radiological investigations and procedures, can significantly increase the radiation burden.

Cerebral hemodynamic changes following carotid endarterectomy: 'cerebral hyperperfusion syndrome'.

Carotid endarterectomy is associated with significant changes in cerebral hemodynamics. In the chronically ischemic brain of patients with carotid stenosis, this can result in postoperative development of 'cerebral hyperperfusion syndrome'. This can cause severe cerebral edema, intracerebral hemorrhage and death. Impaired autoregulation as a result of endothelial dysfunction mediated by the generation of free oxygen radicals is implicated in the pathogenesis of cerebral hyperperfusion syndrome. Intensive blood pressure monitoring and control forms the backbone of treatment. Complete recovery occurs in mild cases, but disability and death can occur in more severe cases. This review concentrates on the mechanism, current management and identification of risk factors that can predispose to this rare but potentially life threatening complication.

Remote ischemic preconditioning for cerebral and cardiac protection during carotid endarterectomy: results from a pilot randomized clinical trial.

Remote ischemic preconditioning (RIPC) is a physiological mechanism whereby brief ischemia-reperfusion episodes attenuate damage by subsequent prolonged ischemic insults. It reduces myocardial injury following cardiac and aortic aneurysm surgery. We aimed to determine whether RIPC affects neurological or cardiac injury following carotid endarterectomy (CEA). Patients were preconditioned using 10 minutes of lower limb ischemia-reperfusion. The primary neurological outcome was saccadic latency deterioration. The primary cardiac outcome measure was increased in serum troponin I >0.15 mg/dL. In all, 70 patients were randomized, of whom 55 completed the neurological surveillance protocol. Although there were fewer saccadic latency deteriorations in the RIPC arm, this did not reach statistical significance (32% versus 53%; P = .11). The primary cardiac outcome occurred in 1 patient in each arm (P = .97). There were no adverse events related to the preconditioning protocol. Remote ischemic preconditioning appears safe in patients with CEA. Large-scale trials are required to determine whether RIPC confers clinical benefits.

Remote ischemic preconditioning for renal protection during elective open infrarenal abdominal aortic aneurysm repair: randomized controlled trial.

We aimed to determine whether remote ischemic preconditioning (IP) reduces renal damage following elective open infrarenal abdominal aortic aneurysm (AAA) repair. Sequential common iliac clamping was used to induce remote IP in randomized patients. Urinary retinol binding protein (RBP) and albumin-creatinine ratio (ACR) were measured following induction and 3, 24, and 48 hours postoperatively. In controls (n = 22), median urinary RBP increased from 112 microg/mL (interquartile range [IQR] 96-173 microg/mL) preoperatively to 5919 microg/mL (IQR 283-17 788 microg/mL) at 3 hours. Preoperative urinary RBP in preconditioned patients was 96 microg/mL (IQR 50 to 229 microg/mL) preoperatively, rising to 1243 microg/mL (IQR 540 to 15400 microg/mL) at 3 hours. Although control patients' median urinary RBP level was 5 times greater at 3 hours, there were no statistically significant differences in renal outcome indices. This trial could not confirm that remote IP reduces renal injury following elective open aneurysm surgery.

Remote ischemic preconditioning will reduce graft-related events after surgical infrainguinal revascularization: evidence-based surgery hypothesis.

Surgical lower extremity revascularization obligates ischemia-reperfusion, and local ischemia-reperfusion provokes systemic inflammation; perhaps counterintuitively, remote ischemic preconditioning elicits a constructive anti-inflammatory response. So, remote ischemic preconditioning will decrease graft-related complications after surgical infrainguinal revascularization.

Objective assessment of the hemisphere-specific neurological outcome of carotid endarterectomy: a quantitative saccadometric analysis.

BACKGROUND: Carotid endarterectomy (CEA) improves the cerebrovascular prognosis of patients with carotid stenosis but carries a risk of causing postoperative neurological deterioration. OBJECTIVE: We assessed hemisphere-specific changes in saccadic eye movements to determine the utility of saccadometry as a quantitative neurosurgical outcome measure. METHODS: Visually evoked saccades were recorded at the bedside before and 2 days after surgery from 30 patients undergoing CEA for symptomatic carotid stenosis. Hemisphere-specific latency distributions were compared using Kolmogorov-Smirnov statistics. Latency distributions were fitted using the Linear Approach to Threshold with Ergodic Rate model and compared with binomial logistic regression. RESULTS: There were 21 males and mean age at surgery was 71±7 years. Following CEA, the distribution of saccades initiated by the cerebral hemisphere distal to the operated artery significantly changed in 25 patients. By contrast, there were 14 significant contralateral-hemisphere saccadic changes (P<.001). Significant contralateral saccadic changes always co-occurred with significant ipsilateral changes and 10 of 14 patients with contralateral saccadic change had contralateral carotid stenosis. There was a significantly greater postoperative reduction in early saccades generated by the ipsilateral hemisphere than by the contralateral hemisphere (P<.02) CONCLUSION: CEA leads to significant hemisphere-specific subclinical changes in saccadic performance and, in particular, differentially affects the proportion of early saccades, a measure of the ability of the frontal cortex to successfully inhibit lower centers, generated by the 2 hemispheres. Saccadometry, a bedside test, provides data that can be statistically compared for individual and groups of patients. It could allow the neurological outcome of carotid surgery to be objectively quantified.

Atrial fibrillation following elective open abdominal aortic aneurysm repair.

BACKGROUND: Atrial fibrillation is a common complication following major vascular surgery. It is often considered to be relatively benign but may represent the first sign of cardiac and non-cardiac complications. We conducted a retrospective study to determine the incidence and clinical associations of atrial fibrillation following open elective abdominal aortic aneurysm repair as well as its effect on prognosis. METHODS: The case-notes of 200 consecutive patients undergoing open aneurysm repair were reviewed. Known pre-operative and intra-operative risk factors and potential post-operative associations with new-onset AF were recorded. Significant univariate correlates with AF were entered into a forward stepwise logistic regression model to test for independence. The effect of new-onset AF on long-term prognosis was assessed. RESULTS: AF developed in 20 patients (10%) post-operatively. Previous cerebrovascular disease, aneurysm size and post-operative cardiac failure were associated with post-operative AF in univariate analyses. Cerebrovascular disease and post-operative cardiac failure were independently associated with new-onset AF. AF patients had a longer hospital stay. There was no difference in survival between those patients with and without new-onset AF. CONCLUSION: New-onset AF is a common complication of open abdominal aortic aneurysm surgery and may indicate an underlying myocardial infarction. It is associated with a longer hospital stay and an increased risk of cardiac failure. Assessed and treated appropriately, it appears to have no effect on long-term prognosis.

Utility of high resolution MR imaging to assess carotid plaque morphology: a comparison of acute symptomatic, recently symptomatic and asymptomatic patients with carotid artery disease.

OBJECTIVES: Compare carotid plaque morphology of acute symptomatic, recently symptomatic and asymptomatic patients (groups 1, 2 and 3 respectively) with carotid artery disease using high resolution magnetic resonance imaging (MRI), to identify high-risk plaque characteristics best associated with risk of recurrent thrombo-embolic events. METHODS: 60 patients underwent multi-contrast imaging of their internal carotid arteries. Different plaque components were manually delineated on acquired axial images to assess the difference in prevalence of plaque hemorrhage, fibrous cap (FC) rupture and FC thickness among the three groups. RESULTS: 55% acute symptomatic patients had plaque hemorrhage vs. 35% for recently symptomatic group and 5% for asymptomatic group (p-value: group 1 vs. 3: 0.001, group 2 vs. 3: 0.04). Type 1 hemorrhage was more common in acute symptomatic patients than recently symptomatic patients (40% vs. 5%, p=0.01). Type 2 hemorrhage was more common in recently symptomatic vs. acute symptomatic patients (15% vs. 30%). FC rupture was observed in 50% of patients in group 1 vs. 35% of group 2 patients (p=0.02) but none in group 3. The mean minimum FC thickness was same in acute and recently symptomatic groups (600+/-200microm), compared to 800+/-200microm for asymptomatic patients (p-value: 0.03 and 0.007 respectively). Good correlation was present among the three MR readers (intra-class correlation coefficient=0.71). CONCLUSION: High resolution MRI can differentiate plaque components associated with increased risk of thrombo-embolic events.

The ATHEROMA (Atorvastatin Therapy: Effects on Reduction of Macrophage Activity) Study. Evaluation using ultrasmall superparamagnetic iron oxide-enhanced magnetic resonance imaging in carotid disease.

OBJECTIVES: The aim of this study was to evaluate the effects of low-dose (10 mg) and high-dose (80 mg) atorvastatin on carotid plaque inflammation as determined by ultrasmall superparamagnetic iron oxide (USPIO)-enhanced carotid magnetic resonance imaging (MRI). The hypothesis was that treatment with 80 mg atorvastatin would demonstrate quantifiable changes in USPIO-enhanced MRI-defined inflammation within the first 3 months of therapy. BACKGROUND: Preliminary studies indicate that USPIO-enhanced MRI can identify macrophage infiltration in human carotid atheroma in vivo and hence may be a surrogate marker of plaque inflammation. METHODS: Forty-seven patients with carotid stenosis >40% on duplex ultrasonography and who demonstrated intraplaque accumulation of USPIO on MRI at baseline were randomly assigned in a balanced, double-blind manner to either 10 or 80 mg atorvastatin daily for 12 weeks. Baseline statin therapy was equivalent to 10 mg of atorvastatin or less. The primary end point was change from baseline in signal intensity (DeltaSI) on USPIO-enhanced MRI in carotid plaque at 6 and 12 weeks. RESULTS: Twenty patients completed 12 weeks of treatment in each group. A significant reduction from baseline in USPIO-defined inflammation was observed in the 80-mg group at both 6 weeks (DeltaSI 0.13; p = 0.0003) and at 12 weeks (DeltaSI 0.20; p < 0.0001). No difference was observed with the low-dose regimen. The 80-mg atorvastatin dose significantly reduced total cholesterol by 15% (p = 0.0003) and low-density lipoprotein cholesterol by 29% (p = 0.0001) at 12 weeks. CONCLUSIONS: Aggressive lipid-lowering therapy over a 3-month period is associated with significant reduction in USPIO-defined inflammation. USPIO-enhanced MRI methodology may be a useful imaging biomarker for the screening and assessment of therapeutic response to "anti-inflammatory" interventions in patients with atherosclerotic lesions. (Effects of Atorvastatin on Macrophage Activity and Plaque Inflammation Using Magnetic Resonance Imaging [ATHEROMA]; NCT00368589).