An Appraisal of Different Cardiac Risk Reduction Strategies in Vascular Surgery Patients

OBJECTIVES: to summarize existing evidence regarding the benefits and the risks of all available interventional and medical means aimed at cardiac risk reduction in patients undergoing vascular surgery. DESIGN: review of the literature. MATERIALS AND METHODS: a critical review of all studies examining the impact of various prophylactic cardiac maneuvers on perioperative outcome following vascular surgery was performed. Overall mortality, cardiac mortality and myocardial infarction rate were used as the outcome measures. RESULTS: coronary artery bypass grafting is associated with a 60% decrease in perioperative mortality in patients undergoing vascular surgery, but in most of the cases this decrease does not outweigh the combined risk of the cardiac and the subsequent noncardiac vascular procedure. Data supporting the cardioprotective effect of percutaneous transluminal angioplasty in the perioperative setting are insufficient. beta-blockade has been shown to decrease perioperative mortality and cardiac morbidity in both high-risk (strong evidence) and low-risk (weak evidence) patients. CONCLUSIONS: coronary revascularization is rarely indicated to simply get the patient through vascular surgery and should be reserved for patients who would need it irrespective of the scheduled vascular procedure. Among all available pharmacological agents, including beta-blockers, alpha-agonists, calcium channel blockers and nitrates, only beta-blockers have been proven to reduce the cardiac risk of vascular surgery.     

A Prospective Randomized Blinded Trial of Remote Ischemic Preconditioning in Children Undergoing Cardiac Surgery

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Carotid Sinus Nerve Blockade During Carotid Surgery: a Randomised Controlled Trial

OBJECTIVES: we investigated whether carotid sinus nerve infiltration with lignocaine reduced blood pressure lability during the first 24h following carotid endarterectomy (CEA). DESIGN: prospective randomised double-blind controlled trial. MATERIALS: eighty patients undergoing CEA for significant symptomatic stenosis of the internal carotid artery. METHODS: after initial dissection, 5 ml of 1% lignocaine or normal saline placebo according to randomisation was infiltrated around the carotid sinus nerve. Blood pressure was measured by intra-arterial cannula during surgery and for four hours afterwards every 15 min, then manually, hourly for 18 h. RESULTS: patients having excision of the carotid sinus nerve were grouped separately for analysis: 29 patients had lignocaine, 33 placebo and 17 excision (one early death with incomplete data was excluded). Mean systolic, diastolic and pulse pressures did not differ significantly between the three groups before carotid sinus nerve infiltration. After infiltration, those patients who had carotid sinus nerve excision, had significantly higher systolic [mean (SD)=155 (16)mmHg] and diastolic [75 (9)mmHg] pressures than those receiving LA [systolic=136 (15)mmHg, diastolic=65 (10)mmHg] or placebo [systolic=136 (19)mmHg, diastolic=65 (9)mmHg], (p<0.005 ANOVA). Nerve excision also resulted in wider variability of blood pressure as defined by the mean of individual standard deviations (systolic=25 mmHg, diastolic=13 mmHg) compared to LA (systolic=19 mmHg, diastolic=12 mmHg) or placebo (systolic=18 mmHg, diastolic=10 mmHg) (p<0.05 ANOVA). Normotensive patients had significantly lower mean diastolic pressures (p<0.001 ANOVA) and variability (p<0.05) if they received lignocaine although this did not influence pulse pressure. CONCLUSIONS: lignocaine injection of the carotid sinus nerve has no benefit in those patients with existing treated hypertension and only marginal effects in normotensives. It is more important to preserve the carotid sinus nerve if possible.     

Preoperative Nutritional Status Predicts the Severity of the Systemic Inflammatory Response Syndrome (SIRS) Following Major Vascular Surgery

OBJECTIVES: This study examined the relationship between pre-operative nutritional status and systemic inflammatory response syndrome (SIRS) or sepsis following major vascular surgery. DESIGN AND METHODS: Subjects undergoing open AAA repair, EVAR or lower limb revascularisation were studied prospectively. Pre-operative nutrition was assessed clinically using Mini-Nutritional Assessment (MNA) and body composition was measured by dual energy X-ray absorptiometry (DEXA) scanning. SIRS severity was assessed for 5 post-operative days and sepsis noted within 30 days of surgery. RESULTS: Using MNA, neither SIRS severity nor sepsis occurrence differed significantly between 'well-nourished' subjects and those 'at risk of malnutrition'. Using DEXA, negative associations existed between body mass index and both SIRS score and SIRS duration. Fat free mass (FFM) was negatively associated with SIRS score and duration. Negative associations also existed between skeletal muscle mass (SMM) and SIRS score and duration. SMM was also negatively correlated with post-operative length of stay in hospital. There were no significant correlations between sepsis and any nutritional indices. CONCLUSIONS: Lower pre-operative nutritional indices, indicating protein energy malnutrition, were associated with more severe systemic inflammatory responses following major vascular surgery.     

Personalized Blood Pressure Management During Cardiac Surgery With Cerebral Autoregulation Monitoring: A Randomized Trial

Four hundred sixty patients undergoing cardiac surgery with cardiopulmonary bypass were randomized to have mean arterial pressure targets to be above the lower limit of cerebral autoregulation or based on usual institutional care. The primary composite outcome of clinical stroke, brain MRI diffusion weighted ischemic injury, or delayed neurocognitive recovery were not different between groups. A lower frequency of clinically detected delirium and better performance on tests of memory were observed in the autoregulation versus the usual care groups. (Graphical work courtesy of Naveen Nathan, MD)

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Vascular Anomalies During Laparoscopic Renal Surgery: Incidence and Management of Left-Sided Inferior Vena Cava

Background:

Left-sided inferior vena cava (IVC) is an unusual abnormality that may be clinically significant during renal surgery.

Methods:

We report the unique case of a patient with a centrally located left renal mass who underwent laparoscopic radical nephrectomy. During the hilar dissection, unusual vascular anatomy was encountered. The patient was noted to have a left-sided inferior vena cava with multiple renal veins and anomalous tributaries. Laparoscopic radical nephrectomy was performed without complication.

Discussion:

The embryology of a left-sided inferior vena cava is reviewed, and the safety and feasibility of a laparoscopic approach is discussed.     

人工血管旁路移植术治疗下肢慢性动脉缺血76例临床分析

目的 探讨人工血管旁路移植术治疗下肢慢性动脉缺血的临床疗效。方法 对1982年1月至2002年1月应用人工血管旁路移植术治疗下肢慢性动脉缺血的76例患者进行回顾性分析。结果 本组l、3、5年一期累积通畅率分别为77％、63％、53％；二期累积通畅率分别为94%、74％、66％；累积截肢率为9．2％。结论 人工血管重建术是治疗下肢慢性动脉缺血，挽救肢体，改善生活质量的有效方法之一。