Perioperative cardiovascular risk stratification of patients with diabetes who undergo elective major vascular surgery

Insulin Dependence is Associated with Poor Long-Term Outcomes Following AAA Repair

BACKGROUND

While prior studies have confirmed the protective effect of diabetes on abdominal aortic aneurysm (AAA) development, much less is known about the effect of diabetes, and in particular insulin dependence, on outcomes following AAA repair. In this study, we aim to evaluate the role of insulin-dependent diabetes on short-term and long-term outcomes following open and endovascular AAA repair.

METHODS

The Vascular Implant Surveillance and Interventional Outcomes Network (VISION), a registry linking the Vascular Quality Initiative (VQI) data with Medicare claims, was queried for patients who underwent open or endovascular AAA repair from 2011 to the present. Exclusion criteria were unknown diabetes status, prior aortic intervention, maximum aneurysm diameter <45 mm at presentation, and Medicare Advantage coverage due to inconsistent follow-up. Patients were stratified based on diabetes status (no diabetes versus diabetes) and insulin dependence (no diabetes or non-insulin-dependent diabetes versus insulin-dependent diabetes).

RESULTS

Of the 38,437 cases in the VISION endovascular aortic aneurysm (EVAR) and open aortic aneurysm repair (OAR) databases, 21,943 met inclusion criteria. Perioperative outcomes after OAR were comparable between diabetic and nondiabetic patients. However, diabetic patients undergoing EVAR were significantly more likely to have a postoperative myocardial infarction (1.0% vs 0.6%, P = 0.04) and have a 30-day readmission (10.9% vs 8.8%, P < 0.001). Insulin-dependent diabetic patients were more likely to require a 30-day readmission after OAR (24.5% vs 13.5%, P = 0.02) and EVAR (15.1% vs 9.0%, P < 0.001); however, only insulin-dependent diabetes mellitus (IDDM) patients undergoing EVAR experienced higher rates of postoperative myocardial infarction (1.9% vs 0.7%, P < 0.01). After propensity score matching, patients with IDDM undergoing EVAR were additionally at increased risk of mortality at 1-year, 3-year, and 5-year follow-up with the highest risk occurring at the 1-year mark (hazard ratio 1.79, P < 0.0001), while IDDM patients undergoing OAR were only at a significantly increased risk of mortality at 5-year follow-up (hazard ratio 1.90, P = 0.01).

CONCLUSIONS

Patients with insulin-dependent diabetes have greater than 14% one-year mortality following open or endovascular aneurysm repair, compared to 8% for all others. Our findings raise questions about whether insulin-dependent diabetics should have a higher size threshold for prophylactic repair, although further studies are needed to address this question and consider the influence of glycemic control on these outcomes.

Postoperative short-term mortality between insulin-treated and non-insulin-treated patients with diabetes after non-cardiac surgery: a systematic review and meta-analysis

BACKGROUND

Diabetes mellitus is an independent risk factor for postoperative complications. It has been reported that insulin-treated diabetes is associated with increased postoperative mortality compared to non-insulin-treated diabetes after cardiac surgery; however, it is unclear whether this finding is applicable to non-cardiac surgery.

OBJECTIVE

We aimed to assess the effects of insulin-treated and non-insulin-treated diabetes on short-term mortality after non-cardiac surgery.

METHODS

Our study was a systematic review and meta-analysis of observational studies. PubMed, CENTRAL, EMBASE, and ISI Web of Science databases were searched from inception to February 22, 2021. Cohort or case-control studies that provided information on postoperative short-term mortality in insulin-treated diabetic and non-insulin-treated diabetic patients were included. We pooled the data with a random-effects model. The Grading of Recommendations, Assessment, Development, and Evaluation system was used to rate the quality of evidence.

RESULTS

Twenty-two cohort studies involving 208,214 participants were included. Our study suggested that insulin-treated diabetic patients was associated with a higher risk of 30-day mortality than non-insulin-treated diabetic patients [19 studies with 197,704 patients, risk ratio (RR) 1.305; 95% confidence interval (CI), 1.127 to 1.511; p < 0.001]. The studies were rated as very low quality. The new pooled result only slightly changed after seven simulated missing studies were added using the trim-and-fill method (RR, 1.260; 95% CI, 1.076-1.476; p = 0.004). Our results also showed no significant difference between insulin-treated diabetes and non-insulin-treated diabetes regarding in-hospital mortality (two studies with 9,032 patients, RR, 0.970; 95% CI, 0.584-1.611; p = 0.905).

CONCLUSION

Very-low-quality evidence suggests that insulin-treated diabetes was associated with increased 30-day mortality after non-cardiac surgery. However, this finding is non-definitive because of the influence of confounding factors.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021246752, identifier: CRD42021246752.

Pre-operative proteinuria, postoperative acute kidney injury and mortality: A systematic review and meta-analysis

OBJECTIVE

To investigate the association of pre-operative proteinuria with postoperative acute kidney injury (AKI) development as well as the requirement for a renal replacement therapy (RRT) and mortality at short-term and long-term follow-up.

BACKGROUND

Postoperative AKI is associated with surgical morbidity and mortality. Pre-operative proteinuria is potentially a risk factor for postoperative AKI and mortality. However, the results in literature are conflicting.

METHODS

We searched PubMed, Embase, Scopus, Web of Science and Cochrane Library from the inception through to 3 June 2020. Observational cohort studies investigating the association of pre-operative proteinuria with postoperative AKI development, requirement for RRT, and all-cause mortality at short-term and long-term follow-up were considered eligible. Using inverse variance method with a random-effects model, the pooled effect estimates and 95% confidence interval (CI) were calculated.

RESULTS

Twenty-eight studies were included. Pre-operative proteinuria was associated with postoperative AKI development [odds ratio (OR) 1.74, 95% CI, 1.45 to 2.09], in-hospital RRT (OR 1.70, 95% CI, 1.25 to 2.32), requirement for RRT at long-term follow-up [hazard ratio (HR) 3.72, 95% CI, 2.03 to 6.82], and long-term all-cause mortality (hazard ratio 1.50, 95% CI, 1.30 to 1.73). In the subgroup analysis, pre-operative proteinuria was associated with increased odds of postoperative AKI in both cardiovascular (OR 1.77, 95% CI, 1.47 to 2.14) and noncardiovascular surgery (OR 1.63, 95% CI, 1.01 to 2.63). Moreover, there is a stepwise increase in OR of postoperative AKI development when the quantity of proteinuria increases from trace to 3+.

CONCLUSION

Pre-operative proteinuria is significantly associated with postoperative AKI and long-term mortality. Pre-operative anaesthetic assessment should take into account the presence of proteinuria to identify high-risk patients.

PROSPERO REGISTRATION

CRD42020190065.

Complications After Immediate 2-Stage Tissue Expander/Implant Breast Reconstruction: A Deeper Look at the Second Stage

BACKGROUND

Complications after 2-stage tissue expander/implant breast reconstruction have been studied as outcomes of a single procedure. We separately evaluated complications after the second stage and assessed factors associated with the outcomes of the second stage of breast reconstruction.

METHODS

Patients who underwent immediate 2-stage breast reconstruction between February 2010 and April 2017 were retrospectively reviewed. Patient demographics, surgical factors of the first stage of breast reconstruction, and complications and number of revision surgeries after the second stage were recorded. Factors associated with postoperative complications were analyzed, and a risk-scoring system was devised.

RESULTS

We analyzed 619 patients who underwent 653 immediate 2-stage breast reconstructions. Multivariate analysis showed that complications were associated independently with smoking history, radiotherapy, and a final inflation volume of 450 mL or greater. Each factor contributed 1 point in the creation of a risk-scoring system. The overall complication rate was increased as the risk score increased (1.2%, 4.7%, and 16.0% for 0, 1, and 2 risk scores, respectively, P < 0.001). Revision operation rate was also significantly different across the 3 groups (0.2%, 1.6%, and 12.0% for 0, 1, and 2 risk scores, respectively, P < 0.001). The area under the receiver operating characteristic curve was 0.732 and 0.731 for the logistic regression model and risk-scoring system, respectively (P = 0.975).

CONCLUSIONS

In the second stage of immediate 2-stage tissue expander/implant breast reconstruction, the rate of complication and revision surgery can be predicted by a novel risk-scoring system. Greater attention and preventive measures for complications are needed for high-risk patients.

Comparison of outcomes after carotid endarterectomy between type 2 diabetic and non-diabetic patients with significant carotid stenosis

BACKGROUND

We aimed to compare early and late outcomes after carotid endarterectomy (CEA) between Korean type 2 diabetic and non-diabetic patients and to investigate the impact of diabetes on the overall incidence of cardiovascular events after CEA.

METHODS

We retrospectively analyzed 675 CEAs, which were performed on 613 patients with significant carotid stenosis between January 2007 and December 2014. The CEAs were divided into a type 2 diabetes mellitus (DM) group (n = 265, 39.3%) and a non-DM group (n = 410, 60.7%). The study outcomes included the incidence of major adverse events (MAEs), defined as fatal or nonfatal stroke or myocardial infarction or all-cause mortality, during the perioperative period and within 4 years after CEA.

RESULTS

Patients in the DM and non-DM groups did not differ significantly in the incidence of MAEs or any of the individual MAE manifestations during the perioperative period. However, within 4 years after CEA, the difference in the MAE incidence was significantly greater in the DM group (P = 0.040). Analysis of the individual MAE manifestations indicated a significantly higher risk of stroke in the DM group (P = 0.006). Multivariate analysis indicated that diabetes was not associated with MAEs or individual MAE manifestations during the perioperative period, whereas within 4 years after CEA, diabetes was an independent risk factor for MAEs overall (hazard ratio [HR], 1.62; 95% confidence interval [CI] 1.06-2.48; P = 0.026) and stroke (HR, 2.55; 95% CI 1.20-5.41; P = 0.015) in particular.

CONCLUSIONS

Diabetic patients were not at greater risk of perioperative MAEs after CEA; however, the risk of late MAE occurrence was significantly greater in these patients. Within 4 years after CEA, DM was an independent risk factor for the occurrence of MAEs overall and stroke in particular.

Trending Towards Safer Breast Cancer Surgeries? Examining Acute Complication Rates from A 13-Year NSQIP Analysis

As breast cancer surgery continues to evolve, this study highlights the acute complication rates and predisposing risks following partial mastectomy (PM), mastectomy(M), mastectomy with muscular flap reconstruction (M + MF), mastectomy with implant reconstruction (M + I), and oncoplastic surgery (OPS). Data was collected from the American College of Surgeons NSQIP database (2005⁻2017). Complication rate and trend analyses were performed along with an assessment of odds ratios for predisposing risk factors using adjusted linear regression. 226,899 patients met the inclusion criteria. Complication rates have steadily increased in all mastectomy groups (p < 0.05). Cumulative complication rates between surgical categories were significantly different in each complication cluster (all p < 0.0001). Overall complication rates were: PM: 2.25%, OPS: 3.2%, M: 6.56%, M + MF: 13.04% and M + I: 5.68%. The most common predictive risk factors were mastectomy, increasing operative time, ASA class, BMI, smoking, recent weight loss, history of CHF, COPD and bleeding disorders (all p < 0.001). Patients who were non-diabetic, younger (age < 60) and treated as an outpatient all had protective OR for an acute complication (p < 0.0001). This study provides data comparing nationwide acute complication rates following different breast cancer surgeries. These can be used to inform patients during surgical decision making.

Risk of insulin-dependent diabetes mellitus in patients undergoing carotid endarterectomy

OBJECTIVE

There is conflicting evidence regarding the association of diabetes mellitus (DM) and insulin use with outcomes after carotid endarterectomy (CEA). Therefore, we sought to evaluate the risk of insulin-dependent DM (IDDM) and noninsulin-dependent DM (NIDDM) on 30-day outcomes after CEA.

METHODS

We identified patients undergoing CEA from the Targeted Vascular module of the National Surgical Quality Improvement Program (2011-2015) and stratified patients on the basis of their preprocedural symptom status. We compared 30-day outcomes between nondiabetics and patients with NIDDM or IDDM, with 30-day stroke/death as the primary end point.

RESULTS

Of 16,739 CEA patients, 9784 (58%) were asymptomatic, of whom 6720 (69%) had no diagnosis of DM, 1109 (11%) had IDDM, and 1955 (20%) had NIDDM. Of the 6955 symptomatic patients, 4982 (72%) had no diagnosis of DM, 810 (12%) had IDDM, and 1163 (17%) had NIDDM. Among asymptomatic patients, patients with IDDM experienced higher rates of 30-day stroke/death compared with those without DM (3.4% vs 1.5%; P < .001), whereas those with NIDDM experienced rates similar to those of patients without DM (2.1% vs 1.5%; P = .1). Moreover, asymptomatic patients with IDDM and an anatomic high-risk criterion experienced a 30-day stroke/death rate of 6.6%. After adjustment, IDDM was associated with 30-day stroke/death in asymptomatic patients compared with patients without DM (odds ratio, 2.3; 95% confidence interval, 1.5-3.4; P < .001), but NIDDM was not (odds ratio, 1.4; 95% confidence interval, 1.0-2.1; P = .1). In comparison, among symptomatic patients, those with IDDM and NIDDM experienced similar rates of 30-day stroke/death as patients without DM (4.9% vs 3.6% and 4.0% vs 3.6%; both P > .1). After adjustment, neither IDDM nor NIDDM was associated with 30-day stroke/death in symptomatic patients compared with symptomatic patients without DM.

CONCLUSIONS

Rates of 30-day stroke/death after CEA in asymptomatic patients with IDDM exceed international vascular societies' guideline thresholds for acceptable outcomes in asymptomatic patients, especially those with anatomic high-risk criteria. Thus, asymptomatic patients with IDDM may not benefit from CEA, although more data are needed about the natural history of carotid disease in this population.

Impact of diabetes mellitus on early outcome of carotid endarterectomy

BACKGROUND

Diabetes mellitus increases the risk of ischaemic stroke in the general population but its impact on early outcome after the carotid endarterectomy (CEA) is controversial with conflicting results.

PATIENTS AND METHODS

This prospective study includes 902 consecutive CEAs. Patients were divided into non-diabetic and diabetic groups and subsequently analysed. Early outcomes in terms of 30-day stroke and death rates were then analysed and compared.

RESULTS

There were 606 non-diabetic patients. Among 296 diabetic patients, 83 were insulin-dependent. The cumulative TIA/stroke rate was statistically higher in the diabetic group (2.6 vs. 5.7 %, P = 0.02). Stroke was more frequent in the diabetic group (2.0 vs. 4.4 %, P = 0.04) comparedto TIA (0.7 vs. 1.4 %, P = 0.45). Mortality was statistically more frequent in diabetic patients (0.2 vs. 1.7 %, P = 0.01). The 30-day stroke/death rate (2.6 vs. 5.7 %, P = 0.02) was also statistically higher in the diabetic group. Factors that were identified to increase risk of death and stroke in multivariate analysis were: use of insulin for blood glucose control (OR = 2.47, 95 % CI 1.61-4.68, P = 0.01), higher low-density lipoprotein cholesterol value (OR = 1.52, 95 % CI 1.15-2.22, P < 0.01), presence of coronary disease (OR = 2.04, 95 % CI 1.40-3.31, P = 0.03), peripheral artery disease (OR = 2.14, 95 % CI 1.34-3.65, P = 0.02), complicated plaque (OR = 1.77, 95 % CI 1.11-3.68, P = 0.03), contralateral carotid artery occlusion (OR = 2.37, 95 % CI 1.25-4.74, P = 0.02), shunt use (OR = 3.46, 95 % CI 1.18-7.10, P < 0.01), and among diabetic patients higher HbA1c levels (OR = 1.28, 95 % CI 1.05-1.66, P = 0.03). Clamp toleration was associated with lower risk of death and stroke rates (OR = 0.43, 95 % CI 0.23-0.76, P < 0.01).

CONCLUSIONS

In our study, perioperative neurological complications and mortality were statistically higher in diabetic patients compared to non-diabetic patients during CEA. Further research will have to show whether other treatment modalities of carotid artery stenosis and better glycaemia and dyslipidaemia controlling in diabetics can reduce this risk.

Is diabetes a marker of higher risk after carotid revascularization? Experience from a single centre

PURPOSE

This single centre study investigates the influence of diabetes mellitus on outcomes following carotid artery endarterectomy or stenting.

METHODS

In total, 752 carotid revascularizations (58.2% carotid artery stenting and 41.8% carotid endarterectomy) were performed in 221 (29.4%) patients with diabetes and 532 (70.6%) patients without diabetes. The study outcomes were death, disabling and non-disabling stroke, transient ischaemic attack and restenosis within 36 months after the procedure.

RESULTS

Patients with diabetes had higher periprocedural risk of any stroke or death (3.6% diabetes vs 0.6% no diabetes; p < 0.05), transient ischaemic attack (1.8% diabetes vs 0.2% no diabetes; p > 0.05) and restenosis (2.7% diabetes vs 0.6% no diabetes; p < 0.05). During long-term follow-up, there were no significant differences in Kaplan-Meier estimates of freedom from death, any stroke and transient ischaemic attack, between people with and without diabetes for each carotid artery stenting and carotid endarterectomy subgroup. Patients with diabetes showed higher rates of restenosis during follow-up than patients without diabetes (36-months estimate risk of restenosis: 21.2% diabetes vs 12.5% no diabetes; p < 0.05).

CONCLUSION

The presence of diabetes was associated with increased periprocedural risk, but no further additional risk emerged during longer term follow-up. Restenosis rates were higher among patients with diabetes.

Effect of type 2 diabetes, surgical incision, and volatile anesthesia on hemodynamics in the rat

Diabetic patients have increased cardiac complications during surgery, possibly due to impaired autonomic regulation. Anesthesia lowers blood pressure and heart rate (HR), whereas surgical intervention has opposing effects. The interaction of anesthesia and surgical intervention on hemodynamics in diabetes is unknown, despite being a potential perioperative risk factor. We aimed to determine the effect of diabetes on the integrative interaction between hemodynamics, anesthesia, and surgical incision. Zucker type 2 diabetic rats (DM) and their nondiabetic littermates (ND) were implanted with an intravenous port for drug delivery, and a radiotelemeter to measure mean arterial blood pressure (MAP) and derive HR (total n = 50). Hemodynamic pharmacological responses were assessed under conscious, isoflurane anesthesia (~2-2.5%), and anesthesia-surgical conditions; the latter performed as a laparotomy. MAP was not different between groups under conscious conditions (ND 120 ± 6 vs. DM 131 ± 4 mmHg, P > 0.05). Anesthesia reduced MAP, but not differently in DM (ND -30 ± 6 vs. DM -38 ± 4 ΔmmHg, P > 0.05). Despite adequate anesthesia, surgical incision increased MAP, which tended to be less in DM (ND +21 ± 4 vs. DM +13 ± 2 ΔmmHg, P = 0.052). Anesthesia disrupted central baroreflex HR responses to sympathetic activation (sodium nitroprusside 10 μg·kg^-1, ND conscious 83 ± 13 vs. anesthetized 16 ± 5 Δbpm; P < 0.05) or to sympathetic withdrawal (phenylephrine 10 μg·kg^-1, ND conscious -168 ± 37 vs. anesthetized -20 ± 6 Δbpm; P < 0.05) with no additional changes observed after surgical incision or during diabetes. During perioperative conditions, type 2 diabetes did not impact on short-term hemodynamic regulation. Anesthesia had the largest hemodynamic impact, whereas surgical effects were limited to modulation of baseline blood pressure.

Glycaemic optimization for patients with cardiac disease-A before-and-after study

AIM

To investigate if glycaemic profiles and outcomes of patients with diabetes admitted for cardiothoracic surgery or acute coronary syndrome improved after implementation of a structured glycaemia management guideline.

METHODS

This is a retrospective before-and-after comparative analysis of outcomes for all consecutive cardiothoracic and acute coronary syndrome patients with diabetes (N = 375), who were admitted at our tertiary-care university-affiliated hospital during the preguideline period (July-December, 2013) and the postguideline period (July-December, 2014).

RESULTS

A total of 55 cardiothoracic and 136 acute coronary syndrome patients were enrolled in the before period, and 36 cardiothoracic and 148 acute coronary syndrome patients were enrolled in the after period. In the cardiothoracic group, comparing the before vs after period, mean BGL improved (9 vs 8.4 mmol/L, P = .045), but there were no significant differences in the readmission rate (18% vs 14%; P = .6), number of hypoglycaemic episodes (1 vs 1, P = .5) or in-hospital mortality (0% vs 5.6%; P = .08). In the acute coronary syndrome group, there were no significant pre-post differences in the mean BGL (9.4 vs 10.2 mmol/L, P = .14), readmission rate (10% vs 11%; P = .8), number of hypoglycaemic episodes (1 vs 1, P = 1.0) or in-hospital mortality (5% vs 7%; P = .4). Endocrinology referrals increased significantly during the after period.

CONCLUSIONS

Implementation of a structured guideline for glycaemia management on inpatient wards marginally improved glycaemic profiles in the cardiothoracic group but not in the acute coronary syndrome group.

Diabetes Mellitus with Chronic Complications in Relation to Carotid Endarterectomy and Carotid Artery Stenting Outcomes

BACKGROUND

Carotid endarterectomy and carotid artery stenting are effective treatment procedures for carotid artery stenosis. Although diabetes mellitus is highly prevalent among patients undergoing these revascularization procedures, few studies have examined their impact on periprocedural outcomes.

OBJECTIVES

The study aimed to determine whether perioperative outcomes among patients undergoing carotid artery stenting and carotid endarterectomy varied depending on the presence of diabetes with or without chronic complications.

METHODS

We examined adults aged 45 and above hospitalized between 2007 and 2011 in U.S. hospitals who underwent carotid artery revascularization procedures. We used data from the Healthcare Cost and Utilization Project's Nationwide Inpatient Sample and evaluated the influence of diabetes with or without chronic complications on outcomes.

RESULTS

Among patients receiving carotid artery stenting, diabetic patients with chronic complications had significantly increased odds of acute kidney injury (odds ratio [OR]: 3.17, 95% confidence interval [CI]: 2.31-4.35) and longer hospital stay (β: 1.98, 95% CI: 1.58-2.38) compared with nondiabetic patients. Diabetic patients with chronic complications receiving carotid endarterectomy experienced increased odds of myocardial infarction (OR: 1.12, 95% CI: .90-1.40), stroke (OR: 1.29, 95% CI: .97-1.72), perioperative infection (OR: 2.45, 95% CI: 1.29-4.65), mortality (OR: 1.48, 95% CI: 1.01-2.16), and longer hospital stay (β (days): 2.05, 95% CI: 1.90-2.20) compared with nondiabetic patients. No significant increased odds of perioperative outcomes were observed among diabetic patients without chronic complications.

CONCLUSIONS

Uncomplicated diabetes did not appear to convey a higher odds of perioperative outcomes among patients undergoing revascularization. However, the presence of diabetes with chronic complications is an important risk factor in the carotid endarterectomy category.

Characteristics that define high risk in carotid endarterectomy from the Vascular Study Group of New England

OBJECTIVE

The Stenting with Angioplasty and Protection in Patients at High Risk for Endarterectomy (SAPPHIRE) trial compared carotid endarterectomy (CEA) to carotid artery stenting (CAS) among high-risk patients using a model of risk that has not been validated by previous publications. The objective of our study was to determine the accuracy of this high-risk model and to determine the true risk factors that result in patients being at high risk for CEA.

METHODS

Prospectively collected data for 3098 CEAs between 2003 and 2011 at 20 Vascular Surgery Group of New England (VSGNE) centers were used. SAPPHIRE general inclusion criteria and primary outcomes were assessed. Factors that were associated with the primary outcome by analysis of variance (P < .10) and not linearly dependent, as determined by a Pearson correlation analysis, were further assessed for an independent association by multivariate logistic regression. A risk index model was developed for these significant predictors to accurately define high-risk CEA.

RESULTS

The average patient age was 69.9 ± 9.5 years, 60% were male, and 45.7% were asymptomatic. The 1-year composite outcome event rate, defined as postoperative myocardial infarction and stroke or death, was 14.2%. Multivariate analysis (P < .05) found the following independently significant risk factors: age in years (95% confidence interval [CI], 1.0-1.1; P < .001), preadmission living in a nursing home (95% CI, 1.2-6.6; P = .020), congestive heart failure (95% CI, 1.4-2.8; P < .001), diabetes mellitus (DM; 95% CI, 1.1-1.3; P < .001), chronic obstructive pulmonary disease (95% CI, 1.2-1.5; P < .001), any previous cerebrovascular disease (95% CI, 1.1-1.9; P = .003), and contralateral internal carotid artery stenosis (95% CI, 1.0-1.2; P = .001). Three of the SAPPHIRE high-risk criteria-abnormal stress test, recurrent stenosis after CEA, and previous radiotherapy to the neck-were not independently associated with an adverse outcome. Independently significant risk factors not included in the SAPPHIRE criteria are inclusion of ages <80 years, preadmission living in a nursing home, DM, contralateral carotid stenosis, and any previous cerebrovascular accident. The risk index predictors are age in years (40-49: 0 points; 50-59: 2 points; 60-69: 4 points; 70-79: 6 points; 80-89: 8 points), living in a nursing home (4 points), any cardiovascular disease (2 points), congestive heart failure (5 points), chronic obstructive pulmonary disease (3 points), DM (2 points), degree of contralateral stenosis (<50%: 0 points; 50%-69%: 1 point; 70%-near occlusion: 2 points; occlusion: 3 points). High-risk CEA is defined as >13 points, representing adverse outcome rate of 22.5%.

CONCLUSIONS

SAPPHIRE and other previously reported high-risk CAS inclusion criteria do not include all of the factors found to be independently associated with outcomes. Further studies are required to determine whether CAS is inferior to CEA in high-risk patients using a validated model of risk. In addition, this preoperative assessment includes novel criteria that can be used to stratify risks.

Pharmacology in peripheral arterial disease: what the interventional radiologist needs to know

Peripheral arterial disease (PAD) is a progressive disease with significant morbidity and mortality. Risk factor control, using diet and lifestyle modification, exercise, and pharmacological methods, improves symptoms and reduces associated cardiovascular events in these patients. Antiplatelet agents and anticoagulants may be used to reduce the incidence of acute events related to thrombosis. The armamentarium available for symptom relief and disease modification is discussed. Novel treatments such as therapeutic angiogenesis are in their evolutionary phase with promising preclinical data.

Diabetes mellitus does not increase the risk of adverse long-term outcomes after intracranial stent placement

The present study is to investigate whether diabetes mellitus (DM) increases risk of adverse long-term outcomes after intracranial stent placement. Patients receiving intracranial stenting were assigned to DM group and non-DM group according to diabetes status. The long-term follow-up endpoint was composite of any stroke and death within 30 days, any ischemic stroke beyond 30 days, and transient ischemic attack in the territory of the stented artery at any time. A total of 44 stenoses in 43 patients were retrospectively analyzed. The cumulative probability of the composite outcomes were 15.4% (95% CI 15.3-47.3%) at 1 year and 30.8% (95% CI 26.5-33.6%) at 2 years for DM group; 17.5% (95% CI 16.0-31.2%) at both 1 year and 2 years for non-DM group (log-rank test, P = 0.424). After adjusting for the confounders, the risk of DM versus non-DM for composite outcomes remained insignificant (hazard ratio: 2.84, 95% CI 0.46-17.66; P = 0.26). Our results showed that there is no significant difference between patients with DM and without DM in cumulative probability of the composite outcomes. It suggests that based on our data, there is no evidence that DM increases the risk of adverse long-term outcomes after intracranial stent placement.

Effect of isoflurane on myocardial energetic and oxidative stress in cardiac muscle from Zucker diabetic fatty rat

The effect of inhalational anesthetics on myocardial contraction and energetics in type 2 diabetes mellitus is unknown. We investigated the effect of isoflurane (ISO) on force and intracellular Ca(2+) transient (iCa), myocardial oxygen consumption (MVo(2)), and energetics/redox behavior in trabecular muscles from Zucker diabetic fatty (ZDF) rats. At baseline, force and corresponding iCa were lower in ZDF trabeculae than in controls. ISO decreased force in both groups in a dose-dependent manner. ISO did not affect iCa amplitude in controls, but ISO > 1.5% significantly reduced iCa amplitude in ZDF trabeculae. ISO-induced force depression fully recovered as a result of increased iCa when external Ca(2+) was raised in controls. However, both force and iCa remained low in ZDF muscle at elevated external Ca(2+). In controls, force, iCa, and MVo(2) increased when stimulation frequency was increased from 0.5 to 1.5 Hz. ZDF muscles, however, exhibited blunted responses in force and iCa and decreased MVo(2). Oxidative stress levels were unchanged in control muscles but increased significantly in ZDF muscles after exposure to ISO. Finally, the depressive effect of ISO was prevented by 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (Tempol) in ZDF muscles. These findings suggest that ISO dose-dependently attenuates force in control and ZDF muscles with differential effect on iCa. The mechanism of force depression by ISO in controls is mainly decreased myofilament Ca(2+) sensitivity, whereas in ZDF muscles the ISO-induced decrease in contraction is due to worsening oxidative stress, which inhibits iCa and force development.

The impact of diabetes on postoperative outcomes following lower-extremity bypass surgery

OBJECTIVE

The effect of diabetes type (noninsulin dependent vs insulin dependent) on outcomes after lower-extremity bypass (LEB) has not been clearly defined. Therefore, we analyzed associations between diabetes type and outcomes after LEB in patients with critical limb ischemia.

METHODS

We performed a retrospective analysis of 1977 infrainguinal LEB operations done for critical limb ischemia between 2003 and 2010 within the Vascular Study Group of New England. Patients were categorized as nondiabetic (ND), noninsulin-dependent diabetic (NIDD), or insulin-dependent diabetic (IDD) based on their preoperative medication regimen. Our main outcome measures were in-hospital mortality and major adverse events (MAEs)--a composite outcome, including myocardial infarction, dysrhythmia, congestive heart failure, wound infection, renal insufficiency, and major amputation. We compared crude and adjusted rates of mortality and MAEs using logistic regression across diabetes categories.

RESULTS

Overall, 41% of patients were ND, 28% were NIDD, and 31% were IDD. Crude rates of in-hospital mortality were similar across these groups (1.7% vs 3.1% vs 2.1%; P = .211). Adjusted analyses accounting for differences in patient characteristics showed that diabetes is not associated with increased risk of in-hospital mortality. However, type of diabetes was associated with a higher risk of MAEs in both crude (15.1% for ND; 21.1% for NIDD; and 25.2% for IDD; P < .001) and adjusted analyses (odds ratio for NIDD, 1.41; 95% confidence interval, 1.2-1.7; odds ratio for IDD, 1.53; 95% confidence interval, 1.3-1.8).

CONCLUSIONS

Diabetes is a significant contributor to the risk of postoperative complications after LEB surgery, and insulin dependence is associated with higher risk. Quality measures aimed at limiting complications after LEB may have the most impact if these initiatives are focused on patients who are IDD.

Non traumatic lower extremity amputations in younger patients: an 11-year retrospective study

The purpose of this study was to assess morbidity and mortality in patients undergoing non traumatic lower extremity amputations ≤65 years to identify the specific needs of these younger patients. A retrospective study was conducted to determine the demographics, comorbidity and mortality with below-knee amputations and above-knee amputations from 1998 to 2008. A total of 203 amputations were performed on 176 patients who were ≤65 years. Major comorbidities and associated physical findings were peripheral vascular disease, diabetes, pain, gangrene, hypertension, ulcer, local wound infection and hypercholesterolemia. Compared to patients who were not deceased post-amputation, those deceased had a higher prevalence of diabetes, renal failure, coronary artery disease (CAD) and sepsis. Significant predictors of mortality were renal failure (hazard ratio [HR] = 4·19; 95% CI 1·96-8·93), CAD (HR = 3·33; 95% CI 1·42-7·81) and amputation site (above-knee) (HR = 3·26; 95% CI 1·51-7·04). This study showed that younger patients may benefit from an interdisciplinary approach in treating local foot ulcers aggressively and optimising their cardiovascular, renal and diabetic risk factors.

Clinical science review article: understanding the implications of diabetes on the vascular system

Patients with diabetes comprise an extremely complex subset of patients for the vascular surgeon. Often, they have numerous comorbidities that can further complicate matters. The diabetic environment is highly complex and the interplay of various diseases makes this an extremely challenging condition to manage. Knowing the mechanisms by which diabetes inflicts adverse microscopic changes in the vasculature allows the clinician to anticipate problems and minimize the heightened risks observed in diabetic patients undergoing surgery. In this review, we will illustrate how diabetes affects the vasculature and how the molecular and cellular derangements that occur in diabetic environments lead to these pathophysiologic consequences.

Assessing the quality of surgical care in vascular surgery; moving from outcome towards structural and process measures

OBJECTIVES

This study presents a review of studies reporting on quality of care in vascular surgery. The aim of this study was to provide insight in quality improvement initiatives in vascular surgery.

DESIGN

Original data were collected from MEDLINE and EMBASE databases. Inclusion criteria were: description of one of the three factors of quality of care, e.g. process, outcome or structure and prospectively described. All articles identified were ascribed to a domain of quality of care.

RESULTS

57 prospective articles were included, drawn from 859 eligible reports. Structure as an indicator of quality of care was described in 19 reports, process in 7 reports and outcome in 31 reports. Most studies based on structural measures considered the introduction of a clinical pathway or a registration system. Reports based on process measures showed promising results. Outcome as clinical indicator mainly focussed on identifying risk factors for morbidity, mortality or failure of treatment.

CONCLUSIONS

Structure and process indicators are evaluated scarcely in vascular surgery. Many studies in vascular surgery have been focussed on outcomes as indicator of quality of care, but a shift towards process measures should be considered as focus of attention in the future.

Carotid endarterectomy in female patients

OBJECTIVES

To evaluate early and late results of carotid endarterectomy (CEA) in female patients in a large single center experience.

METHODS

Over a 12-year period ending in December 2007, 4009 consecutive primary and secondary CEAs in 3324 patients were performed at our institution. All patients were prospectively enrolled in a dedicated database containing pre-, intra-, and postoperative parameters. Patients were female in 1200 cases (1020 patients; Group 1) and male in the remaining 2809 (2304 patients, Group 2). Early results in terms of intraoperative neurological events and 30-day stroke and death rates were analyzed and compared. Follow-up results were analyzed with Kaplan Meier curves and compared with log-rank test.

RESULTS

Patients of Group 1 were more likely to have hyperlipemia, diabetes, and hypertension; patients of Group 2 were more likely to be smokers and to have concomitant coronary artery disease (CAD) and peripheral arterial disease (PAD). There were no differences in terms of clinical status or degree of stenosis. Patients of Group 2 had a significantly higher percentage of contralateral carotid artery occlusion than patients in Group 1 (6.9% and 3.9%, respectively; P < .001). Thirty-day stroke and death rates were similar in the two groups (1.2% for both groups). Univariate analysis demonstrated the presence of CAD, PAD, diabetes, and contralateral carotid artery occlusion to significantly affect 30-day stroke and death rate in female patients. At multivariate analysis, only diabetes (odds ratio [OR] 3.6, 95% confidence interval [CI] 0.1-0.9; P = .05) and contralateral occlusion (OR 7.4, 95% CI 0.03-0.6; P = .006) were independently associated with an increased perioperative risk of stroke and death. Median duration of follow-up was 27 months (range, 1-144 months). There were no overall differences between the two groups in terms of survival, freedom from ipsilateral stroke, freedom from any neurological symptom, and incidence of severe (>70%) restenosis. In contrast to male patients, univariate and multivariate analysis demonstrated that female patients with diabetes or contralateral occlusion had an increased risk of developing ipsilateral neurological events during follow-up.

CONCLUSIONS

Female sex per se does not represent an adjunctive risk factor during CEA, with early and long term results comparable to those obtained in male patients. However, in our study we found subgroups of female patients at higher surgical risk, requiring careful intra- and postoperative management.

Perioperative blood glucose monitoring and control in major vascular surgery patients

Diabetes mellitus (DM) is an independent predictor for morbidity and mortality in the general population, which is even more apparent in patients with concomitant cardiovascular risk factors. As the prevalence of DM is increasing, with an ageing general population, it is expected that the number of diabetic patients requiring surgical interventions will increase. Perioperative hyperglycaemia, without known DM, has been identified as a predictor for morbidity and mortality in patients undergoing surgery. Moreover, early studies showed that intensive blood-glucose-lowering therapy reduced both morbidity and mortality among patients admitted to the postoperative intensive care unit (ICU). However, later studies have doubted the benefit of intensive glucose control in medical-surgical ICU patients. This article aims to comprehensively review the evidence on the use of perioperative intensive glucose control, and to provide recommendations for current clinical practice. A systematic review was performed of the literature on perioperative intensive glucose control. Based on this literature review, we observed that intensive glucose control in the perioperative period has no clear benefit on short-term mortality. Intensive glucose control may even have a net harmful effect in selected patients. In addition, concerns on the external validity of some studies are important barriers for widespread recommendation of intensive glucose control in the perioperative setting. We propose that guidelines recommending intensive glucose control should be re-evaluated. In addition, moderate tight glucose control should currently be regarded as the safest and most efficient approach to patients undergoing major vascular surgery.

Mortality in diabetic patients undergoing non-cardiac surgery: a 7-year follow-up study

BACKGROUND

The prognosis of diabetic patients after non-cardiac surgery remains controversial. This study was designed to compare the long-term mortality between diabetic and non-diabetic control patients undergoing non-cardiac surgery and to evaluate the possible risk factors.

METHODS

We investigated 274 consecutive diabetic patients and 282 non-diabetic control patients who underwent non-cardiac surgery within 1 year in a tertiary care hospital in Finland. The control group was matched for the same type of operations. Patients were followed for up to 7 years on average. The main outcome measure was mortality within 7 years.

RESULTS

Mortality both in the short-term postoperatively (< or =21 days) and in the long-term (up to 87 (1/2) months) was significantly higher in the diabetic patients compared with the non-diabetic group: 3.5 vs. 0% (P<0.05) and 37.2 vs. 15% (P<0.00001), respectively. The major causes of death among diabetic subjects were diseases of the cardiovascular system (56.8%) compared with non-diabetic patients (18.6%), P<0.0001. We found that diabetes mellitus per se is not a risk factor for post-operative mortality but a combination of variables had a significant effect on both short- and long-term mortality.

CONCLUSION

Diabetic patients undergoing non-cardiac surgery had a significantly higher incidence of short-term post-operative and long-term mortality compared with non-diabetic subjects. We propose a model of predictors of death among diabetic individuals undergoing non-cardiac surgery within a 7-year follow-up. The majority of deaths were associated with cardiovascular diseases.

Cardiovascular risk assessment of the diabetic patient undergoing major noncardiac surgery

Noncardiac surgery is associated with an increased risk for cardiovascular morbidity and mortality. It is important to stratify the risk of these patients for perioperative cardiac events. Diabetes, a presently rapidly expanding disease, is a major risk factor for cardiovascular morbidity and mortality. Importantly, silent ischemia is more common in diabetic patients than in the general population. When preoperative risk assessment identifies an increased risk, further cardiac testing is warranted. The most commonly used stress tests for detecting cardiac ischemia is treadmill or bicycle ergometry. However, patients undergoing noncardiac surgery frequently have limited exercise capacity due to co-morbidities. Pharmacologic testing, such as dobutamine stress echocardiography and dipyridamole myocardial perfusion scintigraphy can be performed in patients with limited exercise capacity. Non-invasive stress testing should be considered, especially in diabetic patients, to detect asymptomatic coronary artery disease. Furthermore, when an increased cardiac risk is assessed, two strategies could be used to reduce the incidence of perioperative cardiac events: 1) prophylactic coronary revascularization from which the value is still controversial, and 2) pharmacological treatment (with beta-blockers, statins and aspirin), associated with improved post-operative outcome.

Comparative study of the management of diabetic versus nondiabetic patients with atherosclerosis obliterans of the lower extremities

The aim of this study was to identify the influence of diabetes mellitus on patients with atherosclerosis obliterans (ASO) of the lower extremities. A prospective study was designed to compare differences between ASO patients with and without diabetes mellitus in regard to clinical characteristics and outcomes of management. Two hundred fifty-three consecutive (61.1%) diabetic and 161 (38.9%) nondiabetic patients were included in this study. Crural artery occlusion occurred more frequently in diabetic patients (tibioperoneal segment 26.5% vs 14.3%; p = .003). Diabetic patients had higher comorbidities, such as ischemic heart disease, disabling stroke, and renal failure. Infection requiring urgent surgical intervention was higher in diabetic patients (39.1% vs 24.2%; p = .001). This required primary major amputation in limb-threatening ischemia superimposed with infection (27.6% vs 17.7%; p = .037). The feasibility (67.2% vs 69.8%; p = .651) and success (74.4% vs 79.0%; p = .481) of revascularization between the two groups were comparable. Diabetic patients often needed more distal revascularization for limb salvage (34.4% vs 18.5%; p = .019). The mortality rate after revascularization was higher in diabetic patients (13.3% vs 2.5%; p = .009). Diabetes mellitus per se has no direct impact on limb salvageability in limb-threatening ischemia. The parity of feasibility and success in revascularization between the two groups should encourage attempts at limb salvage revascularization in diabetic patients.

[Diabetes mellitus - perioperative management]

The prevalence of diabetes in hospitalized adults is conservatively estimated at 12-25% and rising. Poor glucose control and presence of diabetes complications (e.g. diabetic nephropathy, diabetic neuropathy, atherosclerosis) are commonly regarded as risk factors for perioperative morbidity and mortality. Thus it is crucial to determine diabetes comorbidities preoperatively in order to avoid perioperative renal and cardiovascular complications. Perioperative glycemic control is challenging due to preoperative changes in diabetes treatment and the effects of surgery-associated stress hyperglycemia. For patients in general surgical units, evidence for specific glycemic goals is based on epidemiologic and physiologic data rather than clinical trials. According to guidelines of the German Society of Nutrition, the approximation of normoglycemia is reasonable as long as hypoglycemia is avoided (suggested range for plasma glucose 80-145 mg/dL).

Risk factors for oral postoperative infection in patients with diabetes

The prevalence of diabetes mellitus in the general population has been increasing sharply. Currently, much is feared but little is known about postoperative complications of oral surgery among persons with diabetes. Existing dental education and practice guidelines cite excess infectious risk among patients with diabetes; however, empiric evidence to support such concerns is lacking. In fact, dentists commonly prescribe antibiotics when dental surgical procedures involve bone. This practice may contribute to the rising problem of microbial resistance and may increase overall healthcare costs. The growing number of dental patients with diabetes warrants strengthening the evidence base to guide their dental care and prevent possible morbid complications.

Incidence of ipsilateral postoperative deep venous thrombosis in the amputated lower extremity of patients with peripheral obstructive arterial disease

OBJECTIVE

Patients undergoing amputation of the lower limb due to peripheral arterial disease (PAD) are at risk of developing deep venous thrombosis (DVT). Few studies in the research literature report the incidence of DVT during the early postoperative period or the risk factors for the development of DVT in the amputation stump. This prospective study evaluated the incidence of DVT during the first 35 postoperative days in patients who had undergone amputation of the lower extremity due to PAD and its relation to comorbidities and death.

METHODS

Between September 2004 and March 2006, 56 patients (29 men), with a mean age of 67.25 years, underwent 62 amputations, comprising 36 below knee amputations (BKA) and 26 above knee amputations (AKA). Echo-Doppler scanning was performed preoperatively and on postoperative days 7 and 31 (approximately). All patients received acetylsalicylic acid (100 mg daily) preoperatively and postoperatively, but none received prophylactic anticoagulation.

RESULTS

DVT occurred in 25.8% of extremities with amputations (10 AKA and 6 BKA). The cumulative incidence in the 35-day postoperative period was 28% (Kaplan-Meier). There was a significant difference (P = .04) in the incidence of DVT between AKA (37.5%) and BKA (21.2%). Age >or=70 years (48.9% vs 16.8%, P = .021) was also a risk factor for DVT in the univariate analysis. Of the 16 cases, 14 (87.5%) were diagnosed during outpatient care. The time to discharge after amputation was averaged 6.11 days in-hospital stay (range, 1-56 days). One symptomatic nonfatal pulmonary embolism occurred in a patient already diagnosed with DVT. There was no relation between other comorbidities and DVT. The multivariate analysis showed no association between risk factors and the occurrence of DVT in the amputated extremity. DVT ipsilateral to the amputation did not influence the mortality rate (9.7%).

CONCLUSION

The incidence of DVT in the early postoperative period (<or=35 days) was elevated principally in patients aged >or=70 years and for AKA. Patients with PAD who have recently undergone major amputations should be considered at high risk for DVT, even after hospital discharge. Given the high rate of postoperative DVT observed in this study, we now recommend prophylactic anticoagulation for these patients, but further study is needed to determine the optimal duration and efficacy of this treatment.

Developing a NSQIP module to measure outcomes in children's surgical care: opportunity and challenge

Under the guidance of the American College of Surgeons (ACS) and in partnership with the US Department of Veterans Affairs (VA), the National Surgical Quality Improvement Program (NSQIP) has been developed to improve the quality of surgical care in adults on a national level. Its purpose is to provide reliable, risk-adjusted outcomes data so that surgical quality can be assessed and compared between institutions. Data analysis consists of reporting observed to expected ratios (O/E) for 30-day postoperative mortality and morbidity measurements. A surgical clinical nurse reviewer is assigned at each medical center to collect information on 97 variables, including preoperative, operative, and postoperative factors for patients undergoing major operations in the specialties of general and vascular surgery. Eligible operations are entered into the database on a structured 8-day cycle to ensure representative sampling of cases. Since the introduction of the program into the VA system, there has been a 47% reduction in 30-day postoperative mortality and a 42% reduction in 30-day postoperative morbidity. Over 160 institutions have enrolled with the ACS in its adult NSQIP. In 2005, a planning committee was formed by the ACS and the American Pediatric Surgical Association to explore the development of a children's surgery NSQIP module. In conjunction with the Colorado Health Outcomes Program at the University of Colorado, a program potentially applicable to all children's surgical specialties has been designed. This manuscript describes the development of that Children's ACS-NSQIP module.

Pathological aspects of spontaneous uveitis and retinopathy in HLA-A29 transgenic mice and in animal models of retinal autoimmunity: relevance to human pathologies

PURPOSE

A major increased risk of developing birdshot chorioretinopathy is reported in humans who are HLA-A29-positive. To better characterize this disease, an animal model of HLA-A29-associated disease was developed and the pathology arising spontaneously in these transgenic mice was compared to animal models of autoimmune uveoretinitis and to human pathology.

MATERIALS AND METHODS

HLA-A2902 cDNA (A29c) was obtained from a patient suffering from birdshot retinochoroidopathy and used for transgene construct to generate HLA-A29 transgenic mice. Histopathological examination of the animal cohort was performed up to 15 months of age. It was compared with the ocular pathology developed in C57BL/6 mice and in Lewis rats immunized with retinal autoantigens.

RESULTS

Aging HLA-A29 transgenic mice spontaneously developed an ocular disease with resemblance to experimental retinal-Ag-induced autoimmune ocular disease and to human pathologies shown in birdshot retinochoroidopathy, Vogt-Koyanagi-Harada and sympathetic ophthalmia. Pathogenic mechanisms could possibly be shared by these conditions.

CONCLUSION

Humanized models of ocular inflammation developed in HLA class I and class II transgenic mice will help better understand the mechanisms responsible for ocular inflammation. Local control of autoimmunity in HLA-A29-positive individuals would be an important option for new therapeutic strategies.

Diabetes and early postoperative outcomes following lumbar fusion

STUDY DESIGN

Retrospective cohort study using data from the Nationwide Inpatient Sample administrative data from 1988 through 2003.

OBJECTIVE

To examine perioperative morbidity and mortality for patients with and without diabetes mellitus following lumbar spinal fusion.

SUMMARY OF BACKGROUND DATA

Diabetes has been associated with worse outcomes in a variety of orthopedic procedures including spinal surgery. There is limited evidence that diabetic patients have more complications following lumbar fusion with little published data to support this conclusion.

METHODS

Data from 197,461 patients who underwent lumbar fusion were included. Over 11,000 patients (5.6%) with a postoperative diagnosis of diabetes mellitus were identified. Selected variables were used for comparison of patients with and without diabetes. Bivariate statistical analyses compared postoperative complication rates while multivariate statistics were used to determine likelihood of complications with diabetes.

RESULTS

Bivariate analysis demonstrated that diabetes was significantly associated with postoperative infection, need for transfusion, pneumonia, in-hospital mortality, and nonroutine discharge (P <or= 0.001). Adjusted multivariate regression analyses, however, suggested no difference in mortality although infection, transfusion, and nonroutine discharge continued to be highly significant (P <or= 0.002). Significantly higher inflation adjusted total charges were also present with patients with diabetes as well as increased lengths of stay (P < 0.001).

CONCLUSION

This nationally representative study of inpatients in the United States provides evidence that diabetes is associated with increased risk for postoperative complications, nonroutine discharge, increased total hospital charges, and length of stay following lumbar fusion. Prospective studies to determine causality as well as the potential impact of diabetes control on these variables have not yet been done.

Mid-term results with laser atherectomy in the treatment of infrainguinal occlusive disease

BACKGROUND

Laser atherectomy offers a potential intervention for multivessel infrainguinal disease in patients with poor revascularization options. Despite promising early results reported in the literature, the proper patient population who might benefit from laser atherectomy has yet to be determined.

METHODS

From July 2004 to June 2006, patients undergoing laser atherectomy were retrospectively reviewed and assessed for comorbidities, operative and follow-up variables potentially associated with the end points of nondefinitive therapy, and limb salvage.

RESULTS

During the study period, 40 patients (21 women, 19 men) underwent laser atherectomy, and the average follow-up was 461 +/- 49 days (range, 17 to 1050 days). Their average age was 68 +/- 2 years (range, 43 to 93 years). The indication for laser atherectomy was critical limb ischemia in 26 (65%) and lower limb claudication in 11 (35%). A total of 47 lesions were treated in the following arterial segments: 34 femoropopliteal and 13 infrapopliteal. Femoropopliteal distribution by the Trans-Atlantic Society Classification (TASC) was A in 3, B in 17, C in 10, D in 4, and infrapopliteal lesions distribution was A in 1, B in 3, C in 4, and D in 5. Adjunctive angioplasty was used in 75% of cases. The overall technical success rate (<50% residual stenosis) was 88%. Laser atherectomy-based treatment was the definitive therapy for 23 patients (58%), and the overall 12-month primary patency was 44%. The limb salvage rate at 12 months in 26 patients with critical limb ischemia was 55%. Renal failure was a risk factor for amputation (P < .001) and failed primary patency (P < .05), type 2 diabetes mellitus was a risk factor for amputation (P < .05), and poor tibial runoff was associated with failed primary patency and amputation (P < .05). Outcome was associated with the number of patent infrapopliteal runoff vessels.

CONCLUSION

These data demonstrate that laser atherectomy can be used with high initial technical success rate. Chronic renal failure and diabetes are risk factors for a negative outcome. Poor results in patients with diabetes and renal failure necessitate careful case selection in this subgroup, in which laser atherectomy is less likely to provide a definitive revascularization result or limb salvage.

Comparison of Risk-Adjusted 30-Day Postoperative Mortality and Morbidity in Department of Veterans Affairs Hospitals and Selected University Medical Centers: Vascular Surgical Operations in Women

BACKGROUND

Women with peripheral vascular disease requiring vascular operations are less well studied than their male counterparts. The surgical outcomes of female vascular patients in the Department of Veterans Affairs (VA) and private sector hospitals have not previously been compared, and their preoperative risk profile, postoperative morbidity, and mortality need to be better elucidated.

STUDY DESIGN

Patients undergoing vascular operations at 14 private sector and 128 VA hospitals, from October 2001 through September 2004, had their preoperative characteristics, operative data, and 30-day postoperative morbidity and mortality compared, as part of the Patient Safety in Surgery (PSS) Study. Logistic regression analysis was performed to develop predictive models for morbidity and mortality, which allowed for a comparison of risk-adjusted outcomes between the two hospital groups.

RESULTS

There were 458 vascular surgical operations performed in women in the VA, and 3,535 vascular operations were performed in women in the private sector. Eighteen of 45 preoperative comorbidities and laboratory variables differed considerably between the institutions, and 16 of 18 were adverse among the private sector patients. The unadjusted 30-day mortality rate was higher in the private sector compared with the VA (5.2% versus 2.4%, p=0.008); the unadjusted morbidity rate was higher in the private sector compared with the VA sector (23.4% versus 13.3%, p < 0.0001). After risk adjustment, there was no marked difference between the VA and the private sector in mortality (p=0.12), but the difference in morbidity rates remained pronounced, with an odds ratio of 0.60 for VA versus private sector (95% CI=0.44, 0.81).

CONCLUSIONS

Compared with their VA counterparts, women undergoing vascular operations at private sector hospitals had a higher incidence of preoperative comorbidities; after risk adjustment, mortality did not differ substantially. Despite risk adjustment, the incidence of postoperative morbidity in the VA patients was considerably lower, suggesting unidentified differences in the hospital populations, their processes of care, or both.

Impact of outcomes research on the management of vascular surgery patients

Vascular surgery has traditionally relied on prospective, randomized clinical trials, case-control series from single institutions of excellence, and case studies to guide clinical decision-making. However, the use of a number of new clinical research tools has allowed the vascular surgeon to more critically assess the indications for particular operations, the costs of various procedures from both a monetary and quality-of-life standpoint, and the "real world" outcomes that can be expected from practitioners across the United States, not just from centers of excellence. Decision analysis with modeling of cohorts with desired characteristics and vascular disease has allowed for the objective determination of procedural cost-effectiveness and evaluation of patient quality-of-life issues surrounding vascular procedures. The use of large national administrative databases has yielded important information concerning factors associated with improved outcomes after several vascular procedures across the entire United States, especially after relatively uncommon operations, such as thoracoabdominal aortic aneurysm repair. Administrative data have also enabled us to learn that access to various new endovascular procedures is somewhat limited, especially for the uninsured or poor. Hospital and surgeon volume, as a surrogate marker for quality, has been directly correlated with lower morbidity and mortality as well as differences in perioperative complications after multiple vascular procedures. A certificate of added qualification in General Vascular Surgery has also been shown to improve outcomes in patients undergoing vascular procedures. Finally, pioneered by the Veteran's Affairs administration and championed by the American College of Surgeons, prospectively collected data (National Surgery Quality Improvement Program) from the Veteran's Affairs and private sector hospitals is providing high-quality, risk-adjusted feedback about multiple vascular procedures to the hospital and the individual practitioner. Importantly, the body of literature generated using these new clinical research tools is being monitored by insurers and patients, as well as by the surgeons providing the care. This ultimately will have a direct impact on practice and referral patterns. It is therefore mandatory that vascular surgeons understand these new tools so that we can police our own practices before others, such as insurance companies and hospital administrators, do it for us.

Diabetes mellitus and anesthesia

Diabetes mellitus is an extremely common condition with specific associated comorbidity. Its incidence is rising. Diabetic patients have more perioperative complications than nondiabetic patients. These complications may be related to the presence of organ damage secondary to the diabetes, rather than the defects in carbohydrate metabolism themselves, or to perioperative hyperglycemia. Several new drugs are available for the treatment of diabetes, and these are associated with specific and significant side effects, and varying lengths of action with which the anesthetist should be familiar. Few data are available regarding recommendations for fasting in the presence of these newer drugs. In the postoperative period and during cardiac surgery, hyperglycemia has been shown to be detrimental, and should probably be sought and managed aggressively. The incidence of intraoperative hyperglycemia in noncardiac surgery patients is not as well-defined, nor are the effects of aggressive management.

Creatinine clearance but not serum creatinine alone predicts long-term postoperative survival after lower extremity revascularization

BACKGROUND

Renal insufficiency is a well-described risk factor for perioperative morbidity and shortened survival after major vascular procedures. Due to the potential inaccuracy of serum creatinine levels alone in measuring kidney function, our aim was to determine whether estimated creatinine clearance more consistently predicted long-term survival.

METHODS

A retrospective review of one institution's vascular registry was performed. Logistic regression analysis was conducted to determine independent predictors of 1-, 2- and 3-year postoperative mortality. Creatinine clearance was estimated as [140 - age (years)] x weight (kg)/72 x serum creatinine (mg/dl), multiplied by 0.85 for women.

RESULTS

A total of 252 consecutive patients underwent infrainguinal bypass procedures between August 1999 and May 2000. Demographics included average age 68 years, 65% male, 74% diabetic, 12% dialysis-dependent, 23% history of congestive heart failure, 12% history of stroke and 20% serum creatinine >2 mg/dl. One-year mortality was 16% (n = 40), 2-year mortality was 25% (n = 64), and 3-year mortality was 35% (n = 88). There was no difference in serum creatinine values between survivors and non-survivors at 1 year (1.8 vs. 1.9, p = 0.80), 2 years (1.8 vs. 2.0, p = 0.62) or 3 years (1.8 vs. 2.0, p = 0.24), and creatinine >2 mg/dl did not predict long-term adverse outcomes. In contrast, reduced creatinine clearance (< or =60 ml/min) was an independent predictor of mortality regardless of dialysis status (1 year: OR = 2.53, p = 0.014; 2 years: OR = 2.46, p = 0.004; 3 years: OR = 2.45, p = 0.001), and creatinine clearance was higher for survivors versus non-survivors at all 3 time points (1 year: 70.2 vs. 49.5, p = 0.003; 2 years: 72.3 vs. 51.2, p < 0.0001; 3 years: 74.7 vs. 52.6, p < 0.0001). Other independent predictors of mortality included a history of stroke (1 year: OR = 3.28, p = 0.008; 2 years: OR = 2.55, p = 0.025; 3 years: OR = 2.35, p = 0.038) and congestive heart failure (1 year: OR = 2.86, p = 0.006; 2 years: OR = 2.54, p = 0.005; 3 years: OR = 2.13, p = 0.017).

CONCLUSIONS

Independent of dialysis status, a decreased creatinine clearance, but not elevated serum creatinine alone, is an independent predictor of mortality after lower extremity arterial reconstruction. Determination of creatinine clearance should replace serum creatinine in the preoperative risk evaluations of patients undergoing major vascular surgical procedures.

Defining the high-risk patient for carotid endarterectomy: An analysis of the prospective National Surgical Quality Improvement Program database

BACKGROUND

Carotid endarterectomy (CEA) is the gold standard for the treatment of carotid stenosis, but carotid angioplasty and stenting has been advocated in high-risk patients. The definition of such a population has been elusive, particularly because the data are largely retrospective. Our study examined results for CEA in the National Surgical Quality Improvement Program database (both Veterans Affairs and private sector).

METHODS

National Surgical Quality Improvement Program data were gathered prospectively for all patients undergoing primary isolated CEA during the interval 2000 to 2003 at 123 Veterans Affairs and 14 private sector academic medical centers. Study end points included the 30-day occurrence of any stroke, death, or cardiac event. A variety of clinical, demographic, and operative variables were assessed with multivariate models to identify risk factors associated with the composite (stroke, death, or cardiac event) end point. Adjudication of end points was by trained nurse reviewers (previously validated).

RESULTS

A total of 13,622 CEAs were performed during the study period; 95% were on male patients, and 91% of cases were conducted within the Veterans Affairs sector. The average age was 68.6 +/- 0.1 years, and 42.1% of the population had no prior neurologic event. The composite stroke, death, or cardiac event rate was 4.0%; the stroke/death rate was 3.4%. Multivariate correlates of the composite outcome were (odds ratio, P value) as follows: deciles of age (1.13, .018), insulin-requiring diabetes (1.73, <.001), oral agent-controlled diabetes (1.39, .003), decade of pack-years smoking (1.04, >.001), history of transient ischemic attack (1.41, >.001), history of stroke (1.51, >.001), creatinine >1.5 mg/dL (1.48, >.001), hypoalbuminemia (1.49, >.001), and fourth quartile of operative time (1.44, >.001). Cardiopulmonary comorbid features did not affect the composite outcome in this model. Regional anesthesia was used in 2437 (18%) cases, with a resultant relative risk reduction for stroke (17%), death (24%), cardiac event (33%), and the composite outcome (31%; odds ratio, 0.69; P = .008).

CONCLUSIONS

Carotid endarterectomy results across a spectrum of Veterans Affairs and private sector hospitals compare favorably to contemporary studies. These data will assist in selecting patients who are at an increased risk for adverse outcomes. Use of regional anesthetic significantly reduced perioperative complications in a risk-adjusted model, thus suggesting that it is the anesthetic of choice when CEA is performed in high-risk patients.

The safety of carotid endarterectomy in diabetic patients: clinical predictors of adverse outcome

OBJECTIVES

Patients with diabetes mellitus have been shown to have an increased incidence of complications after elective major vascular surgery. The objective of this study was to evaluate a large series of diabetic patients undergoing carotid endarterectomy (CEA) to determine if outcome differed from nondiabetic patients and to examine predisposing factors of poor outcome among diabetic patients.

METHODS

A retrospective review of a prospectively compiled database was performed. From 1992 through 2000, 2151 CEAs were performed at our institution. Of these, 507 were in diabetic patients (23.6%), and the remaining 1644 procedures were in nondiabetic patients (76.4%).

RESULTS

Diabetic patients were significantly more likely than nondiabetic patients to have hypertension (70.8% vs 64.5%, P = .01) and cardiac disease (54.6% vs 49.1%, P = .03). They were more likely than nondiabetic patients to be symptomatic before surgery (52.5% vs 47.1%, P = .04) and to have sustained a preoperative stroke (21.3% vs 17.7%, P = .07). No differences were noted in other recorded demographic factors or in intraoperative factors between diabetic and nondiabetic patients. Despite these differences, diabetic patients had similar perioperative outcomes compared with nondiabetic patients, including perioperative myocardial infarction (0.6% vs 0.4%, P = NS), perioperative death (0.8% vs 0.5%, P = NS), and perioperative neurologic events such as transient ischemic attack and stroke (3.2% vs 2.4%, P = NS). Among diabetic patients alone, cigarette smoking, general anesthesia, the use of a shunt, and the lack of clamp tolerance while under regional anesthesia predicted adverse perioperative neurologic outcome, and contralateral occlusion was associated with increased perioperative mortality.

CONCLUSIONS

Despite an increased prevalence of cardiac disease and preoperative neurologic symptoms among diabetic patients undergoing CEA, the rates of perioperative cardiac morbidity, mortality, and stroke were equal to nondiabetic patients. In contrast to nondiabetic patients, current cigarette smoking appeared to predict increased adverse neurologic outcomes among diabetic patients, and the presence of contralateral occlusion among diabetic patients appeared to predispose them towards increased perioperative mortality. The use of a general anesthetic appeared to increased perioperative neurologic risk among diabetic patients; however, this may be related to surgeon bias in the selection of anesthetic technique. Although diabetic patients may have an increase in complications after other major vascular surgical procedures, the presence of diabetes mellitus does not appear to significantly increase risk.