Carotid Endarterectomy in Patients with Renal Insufficiency: Should Selection Criteria be Different in Patients with Renal Insufficiency?

A contemporary evaluation of carotid endarterectomy outcomes in patients with chronic kidney disease in the United States

Objectives Chronic kidney disease (CKD) has been identified as a significant risk factor for poor post-surgical outcomes. This study was designed to provide a contemporary analysis of carotid endarterectomy (CEA) outcomes in patients with CKD, end-stage renal disease (ESRD), and normal renal function (NF). Methods The Nationwide Inpatient Sample data 2006-2012 was queried to select patients aging 40 years old and above who underwent CEA during two days after admission and had a diagnosis of ESRD on long-term hemodialysis, patients with non-dialysis-dependent CKD, or NF. Patients with acute renal failure were excluded. We subsequently compared procedure outcomes and hospital resource utilization in these patients. Results Totally 573,723 CEA procedures were estimated: 4801 (ESRD)' 32,988 (CKD)' and 535,934 (NF). Mean age was 71.0 years, 57.7% were males, and 73.7% were white. Overall hospital mortality was 0.20%: 0.69% (ESRD), 0.35% (CKD), and 0.19% (NF), p < 0.0005 between groups. The overall stroke rate was 1.6%: 1.8% (ESRD), 2.0% (CKD), and 1.6% (NF). Comparing NF to CKD there was a significant difference: p < 0.0001. For CKD patients, compared to NF patients, there was an increased risk in cardiac complications (odds ratio = 1.2; 95% CI 1.15-1.32), respiratory complications (odds ratio = 1.2; 95% CI 1.15-1.32), and stroke (odds ratio = 1.1; 95% CI 1.04-1.23). For ESRD patients compared to NF patients there was an increased risk in respiratory complications (odds ratio = 1.3; 95% CI 1.08-1.47) and sepsis (odds ratio = 4.4; 95% CI 3.23-5.94). Mean length of stay and cost were: 2.8 d and $13,903 (ESRD), 2.2 d and $12,057 (CKD), and 1.8 d and $10,130 (NF), all p < 0.0001. Conclusions Patients with ESRD undergoing CEA had an increased risk of respiratory and septic complications, but not a higher risk of stroke compared to patients with normal renal function. The greatest risks of postoperative stroke, respiratory, and cardiac complications were found in patients with CKD. A diagnosis of ESRD and CKD were both found to significantly increase hospital mortality, length of stay and cost. Where clinicians typically consider ESRD patients the highest risk for CEA, further consideration should be given to patients with CKD not yet on dialysis as they had the higher risk of cardiac complications and stroke compared to the others evaluated.

Preoperative steroid use and the risk of infectious complications after neurosurgery

BACKGROUND AND PURPOSE

The association between preoperative corticosteroid use and infectious complications after neurosurgical procedures is unclear. We aim to determine whether corticosteroids increase the risk of infectious complications after neurosurgery.

METHODS

We examined the association between preoperative corticosteroid use and postoperative infectious complications in a cohort of adults who underwent a neurosurgical procedure between 2005 and 2010 at centers participating in the National Surgical Quality Improvement Program. Corticosteroid use was defined as at least 10 days of oral or parental therapy in the 30 days prior to surgery. Our primary outcome was a composite of any infectious complications occurring within 30 days of surgery. We used propensity score analysis to examine the independent association between preoperative corticosteroid use and postoperative infections.

RESULTS

Among 26 634 neurosurgical procedures, 1228 (4.61%, 95% confidence interval [CI], 4.36-4.86) were preceded by preoperative corticosteroid use and 1469 (5.52%; 95% CI, 5.24-5.79) were followed by postoperative infections. In a propensity score analysis controlling for comorbidities, illness severity, and preexisting preoperative infections, corticosteroid use was independently associated with subsequent postoperative infections (odds ratio, 1.38; 95% CI, 1.11-1.70). Our results were unchanged in sensitivity analyses controlling for central nervous system tumors or active treatment with chemotherapy.

CONCLUSION

Our results suggest that preoperative corticosteroid use is associated with an increased risk of infectious complications after neurosurgery. These findings may aid physicians with preoperative treatment decisions and risk stratification. Future randomized trials are needed to guide preoperative use of corticosteroids in this population.

Impact of chronic kidney disease on carotid plaque vulnerability

OBJECTIVE

Little is known about the effect of chronic kidney disease (CKD) on plaque morphology in cerebral vessels. We therefore analyzed plaque composition and metabolic and chemical parameters with regard to clinical outcome in patients with advanced carotid artery stenosis (>70%) and normal or impaired renal function.

METHODS

Carotid endarterectomy plaques were collected from 114 patients, 51 with CKD and 63 without CKD (mean estimated glomerular filtration rate, 49 ± 9 vs 88 ± 14 mL/min), and analyzed by histology and immunohistochemistry. Serum levels of matrix metalloproteinases (MMP-1, -2, -3, -7, -8, and -9), calcium, phosphate, parathyroid hormone, fetuin-A, osteoprotegerin, and inflammatory factors, including fibrinogen, and high-sensitive C-reactive protein (hsCRP) were measured by appropriate enzyme-linked immunosorbent assay.

RESULTS

Compared with patients without CKD, patients with CKD had significantly more early-stage (11.2% vs 2.8%, P = .002) and end-stage (7.4% vs 0.2%, P = .036) calcification, unstable (50.8% vs 20.4%, P = .001) and ruptured (53.1% vs 32.8%, P = .035) lesions, and a significantly lower amount of collagenous fibers (39.2% vs 54.6%, P = .001). Serum samples of CKD patients had significantly enhanced levels of fibrinogen (393 ± 88 vs 331 ± 60 mg/dL, P = .018), hsCRP (1.7 ± 2.9 vs 0.8 ± 0.9 mg/dL; P = .042), parathyroid hormone (47.3 ± 24.1 vs 32.8 ± 12.2 ng/L, P = .010), fetuin-A (0.21 ± 0.05 vs 0.18 ± 0.04 mg/mL, P = .039), and MMP-7 (13.0 ± 5.3 vs 8.3 ± 3.0 ng/mL; P < 0.001). The incidence of cerebrovascular events >6 months before carotid surgery was significantly increased in CKD patients (84.0% vs 26.2% P < .001).

CONCLUSIONS

In patients with CKD and advanced carotid artery stenosis, morphologic changes in plaque composition may contribute to plaque vulnerability and consequently to the risk of cerebrovascular events. Furthermore, relevant serum markers of inflammation, vascular calcification, and vessel wall degradation might be an indication of stroke risk in CKD patients.

Carotid endarterectomy benefits patients with CKD and symptomatic high-grade stenosis

Endarterectomy is generally recommended for symptomatic high-grade (70 to 99%) stenosis of the internal carotid artery, but whether this procedure is beneficial among patients with chronic kidney disease (CKD) is unknown. In this re-analysis of data from the North American Symptomatic Carotid Endarterectomy Trial, we included patients with symptomatic stenosis and either stage 3 CKD (n = 524) or preserved kidney function (n = 966; estimated GFR > or = 60). For medically treated patients with high-grade stenosis, risk for ipsilateral stroke at 2 yr was significantly higher in patients with CKD than in those with preserved renal function (31.6 versus 19.3%; P = 0.042); carotid endarterectomy significantly reduced this risk by 82 and 51%, respectively. To prevent one ipsilateral stroke, the number needed to treat by endarterectomy was four for patients with CKD and 10 for patients with preserved renal function. Compared with patients with preserved renal function, those with CKD had similar rates of perioperative stroke and death but higher rates of cardiac events. In conclusion, patients with stage 3 CKD and symptomatic high-grade carotid stenosis gain a large benefit in stroke risk reduction after endarterectomy.

Carotid plaque composition in chronic kidney disease: a retrospective analysis of patients undergoing carotid endarterectomy

OBJECTIVES

Calcified plaques are suggested to represent atherosclerotic lesions with stabilising properties. However, patients with chronic kidney disease (CKD) frequently have calcified plaques but significant higher prevalence of cardiovascular complications. The aim of our study was therefore to analyse the effect of CKD in patients with advanced carotid stenosis (>70%) on plaque composition, lesion stability and risk of rupture.

METHODS

We investigated retrospectively, by histology, carotid plaques of patients with high-grade internal carotid artery stenosis undergoing carotid endarterectomy. Comparison of plaque morphology was performed on 41 patients with CKD with estimated glomerular filtration rate (eGFR) <60 ml min(-1) (according to the Modification of Diet in Renal Disease formula, MDRD-eGFR) and 56 patients with normal renal function.

RESULTS

Patients with CKD had significantly higher percentage of total calcification (17% vs. 7%, p<0.001), unstable and ruptured plaques (83% vs. 52%, p=0.001 and 59% vs. 36%, p=0.039, respectively) compared with patients with normal renal function. By contrast, the content of collagenous fibres was significantly reduced in CKD patients (40% vs. 57%, p=0.011). No significant differences were found for neurological symptoms and soft plaque content.

CONCLUSION

Our results demonstrate that CKD significantly affects plaque composition in patients with advanced carotid artery stenosis. Enhanced calcification and reduced collagenous plaque may lead to plaque instability and rupture.

Outcomes of carotid endarterectomy for asymptomatic stenosis in Sweden are improving: Results from a population-based registry

OBJECTIVE

In large randomized trials, carotid endarterectomy (CEA) for asymptomatic stenosis has shown a net benefit compared with best medical treatment. To justify an increased number of procedures for this indication, the perioperative risk of stroke or death must not exceed that of the trials. The aim of this study was to evaluate the outcome in routine clinical practice in Sweden in a population-based study.

METHODS

The Swedish Vascular Registry (Swedvasc) covers all centers performing CEA. Data on all registered CEAs during 1994 to 2003 were analyzed both for the whole time period and for two 5-year periods to study alterations over time. Four validation procedures of the registry were performed. Medical records were reviewed for both a random sample and a target sample (a total of 12% of the CEAs for asymptomatic stenosis). Swedvasc data were cross-matched with the In-Patient-Registry (used for reimbursement) and the Population-registry (death).

RESULTS

A total of 6182 CEAs were registered, 671 being for asymptomatic stenosis. In the validation process, no missed registration of major stroke or death was found. Patients with asymptomatic stenosis had, when the whole time-period was analyzed, a perioperative combined stroke or death rate of 2.1%. Outcome improved over time; the combined stroke or death rate decreased from 3.3% (11/330) from 1994 to 1998 to 0.9% (3/341) from 1999 to 2003 (P = .026). During the second time period, no patient with a perioperative major stroke or death was reported.

CONCLUSIONS

This extensively validated national audit of CEA for patients with asymptomatic carotid artery stenosis showed results well comparable with those of the randomized trials. The results improved over time.