Effect of chronic renal insufficiency on outcomes of carotid endarterectomy

Evaluation of the relationship between proximal upper-extremity arteriovenous fistula patency and atherogenic index of plasma

BACKGROUND

The continuity of arteriovenous fistula (AVF) patency is essential for effective hemodialysis. In the present study, we aimed to investigate the relationship between AVF patency and atherogenic index of plasma (AIP) in patients with native proximal upper-extremity AVF.

METHODS

A total of 143 patients with native proximal upper-extremity AVF created in our clinic between January 2014 and April 2022 were analyzed retrospectively. Those with at least 24 months of follow-up and intact AVF were defined as "Group 1" (n = 97), and those with AVF thrombosis were defined as "Group 2" (n = 46).

RESULTS

The primary patency rates of the patient groups included in the study were found to be 88.1% at 6th month, 79% at 12th month, and 67.8% at 24th month. The mean AIP values that were calculated in Group 2 were found to be statistically significantly higher than the mean value calculated in Group 1 (0.30 ± 0.12 vs 0.20 ± 0.10, p < 0.001). In a multivariate logistic regression analysis made to identify the predictors of proximal upper-extremity AVF thrombosis development, total cholesterol (OR [odds ratio] = 2.259, 95% CI [confidence interval] = 1.468-3.475, p < 0.001), and triglyceride (OR = 13.777, 95% CI = 3.740-50.750, p < 0.001) were identified as independent predictors.

CONCLUSION

A significant relationship was detected in the analyses between the easily calculated AIP values and the development of AVF thrombosis. The AIP is a remarkable preoperative parameter regarding proximal upper-extremity AVF patency.

Outcomes of balloon-assisted maturation with large-diameter balloons

OBJECTIVES

Balloon-assisted maturation (BAM) is a well-established technique for maturation of inadequate arteriovenous fistulas (AVF). The objective of this study was to evaluate outcomes of initial BAM using large-diameter angioplasty balloons.

METHODS

Charts of patients who underwent BAM between 2018 and 2021 at a single academic institution were reviewed. AVF maturation rate was the primary outcome. Secondary outcomes included procedural complications, re-intervention rates, post-procedure vein diameter, and time to catheter-free hemodialysis (HD). Outcomes of patients that underwent initial BAM with ⩾7 mm diameter balloons (Group I) were compared to those of patients that had initial BAM with <7 mm balloons (Group II).

RESULTS

Group I (n = 149) was a significantly younger cohort and had more men compared to Group II (n = 90). There were no significant differences associated with procedural details and complication rates. Median vein diameter was larger (5.9 mm, IQR: 5-6.4) in Group I compared to Group II (5.1 mm, IQR: 4.2-5.9; p = 0.03) on post-procedure Duplex ultrasound. There was also a higher incidence of vein stenosis in Group II. The overall maturation rate was higher in Group I (97% vs 88%, p = 0.003), and a larger proportion of patients in Group II required more than one BAM to achieve maturation (33% vs 16%, p = 0.002). The median time to catheter-free HD after first BAM was 29 days (IQR: 19-47) in Group I and 42 days (IQR: 24-75) in Group II (p = 0.002). At 60 days after first BAM, the incidence of catheter-free HD was 83% in Group I versus 67% in Group II (p = 0.001).

CONCLUSIONS

Our study demonstrates that the ability to utilize large angioplasty balloons during initial BAM is associated with higher rates of AVF maturation with fewer re-interventions and shorter time to catheter-free dialysis. AVFs that can tolerate this procedure often have more favorable baseline characteristics.

Outcomes of carotid revascularization stratified by procedure in patients with an estimated glomerular filtration rate of <30 and dialysis patients

OBJECTIVE

Renal failure is a predictor of adverse outcomes in carotid revascularization. There has been debate regarding the benefit of revascularization in patients with severe chronic kidney disease or on dialysis.

METHODS

Patients in the Vascular Quality Initiative undergoing transcarotid artery revascularization (TCAR), transfemoral carotid artery stenting (tfCAS), or CEA between 2016 and 2023 with an estimated glomerular filtration rate (eGFR) of <30 mL/min/1.73 m2 or on dialysis were included. Patients were divided into cohorts based on procedure. Additional analyses were performed for patients on dialysis only and by symptomatology. Primary outcomes were perioperative stroke/death/myocardial infarction (MI) (SDM). Secondary outcomes included perioperative death, stroke, MI, cranial nerve injury, and stroke/death. Inverse probability of treatment weighting was performed based on treatment assignment to TCAR, tfCAS, and CEA patients and adjusted for demographics, comorbidities, and preoperative symptoms. The χ2 test and multivariable logistic regression analysis were used to evaluate the association of procedure with perioperative outcomes in the weighted cohort. Five-year survival was evaluated using Kaplan-Meier and weighted Cox regression.

RESULTS

In the weighted cohort, 13,851 patients with an eGFR of <30 (2506 on dialysis) underwent TCAR (3639; 704 on dialysis), tfCAS (1975; 393 on dialysis), or CEA (8237; 1409 on dialysis) during the study period. Compared with TCAR, CEA had higher odds of SDM (2.8% vs 3.6%; adjusted odds ratio [aOR], 1.27; 95% confidence interval [CI], 1.00-1.61; P = .049), and MI (0.7% vs 1.5%; aOR, 2.00; 95% CI, 1.31-3.05; P = .001). Compared with TCAR, rates of SDM (2.8% vs 5.8%), stroke (1.2% vs 2.6%), and death (0.9% vs 2.4%) were all higher for tfCAS. In asymptomatic patients CEA patients had higher odds of MI (0.7% vs 1.3%; aOR, 1.85; 95% CI, 1.15-2.97; P = .011) and cranial nerve injury (0.3% vs 1.9%; aOR, 7.23; 95% CI, 3.28-15.9; P < .001). Like in the primary analysis, asymptomatic tfCAS patients demonstrated higher odds of death and stroke/death. Symptomatic CEA patients demonstrated no difference in stroke, death, or stroke/death. Although tfCAS patients demonstrated higher odds of death, stroke, MI, stroke/death, and SDM. In both groups, the 5-year survival was similar for TCAR and CEA (eGFR <30, 75.1% vs 74.2%; aHR, 1.06; P = .3) and lower for tfCAS (eGFR <30, 75.1% vs 70.4%; aHR, 1.44; P < .001).

CONCLUSIONS

CEA and TCAR had similar odds of stroke and death and are both a reasonable choice in this population; however, TCAR may be better in patients with an increased risk of MI. Additionally, tfCAS patients were more likely to have worse outcomes after weighting for symptom status. Finally, although patients with a reduced eGFR have worse outcomes than their healthy peers, this analysis shows that the majority of patients survive long enough to benefit from the potential stroke risk reduction provided by all revascularization procedures.

Brachiocephalic arteriovenous fistula maturity in end stage renal disease: The role of intraoperative brachial artery blood flow rate and peak systolic velocity

Introduction

Arteriovenous fistula (AVF) is the preferred vascular access option due to its lower risk of complications and better long-term outcomes. However, AVF maturation failure is still quite high. Achieving an adequate blood flow rate (BFR) through the AVF is essential for maintaining hemodialysis adequacy. This study aims to investigate brachial artery intraoperative BFR and peak systolic velocity (PSV) increase as a predictor of brachiocephalic AVF maturation.

Methods

A multicenter retrospective cohort study was conducted on patients with end stage renal disease undergoing brachiocephalic AVF creation from July 2019 to February 2022 from five hospitals. Doppler ultrasound examinations of BFR and PSV were collected. BFR and PSV increases were calculated by comparing pre-operative and intraoperative results. Maturity was determined at 6 weeks postoperatively.

Results

This study included 83 patients, with 50 patients (60.24%) achieving maturity at 6 weeks. Brachial artery BFR difference has an excellent diagnostic value to predict brachiocephalic AVF maturation with an area under the curve (AUC) of 97%. BFR increase of 184.58 ml/min predicts brachiocephalic AVF maturity with a sensitivity of 100%, specificity of 84.8%, and accuracy of 93.98%. Meanwhile, brachial artery PSV increase has a low diagnostic value to predict brachiocephalic AVF with an AUC of 71.2%. PSV increase of 8.97 cm/s predicts brachiocephalic AVF maturity with a sensitivity of 82%, specificity of 51.5%, and accuracy of 69.9%.

Conclusion

The increase in intraoperative brachial artery BFR and PSV in brachiocephalic AVF can be used as a useful parameter to predict AVF maturation.

Overlapping stent insertion for a treatment-resistant seroma after arteriovenous fistulation using prosthetic grafts

An arteriovenous fistula was required for permanent vascular access in a patient undergoing hemodialysis due to progressive chronic kidney disease associated with short bowel syndrome. In the present report, we discuss the case of a patient who underwent arteriovenous grafting because there was no proper native vein as a route, following which a seroma developed near the arterial anastomosis. Despite several surgical treatments, seroma not only recurred but also affected dialysis by compressing the graft. A stent was inserted into the graft to withstand the pressure from the seroma, and because one stent could not withstand the pressure, the stent overlapped where it received the most compression. Since then, the patency of graft has been well maintained for more than 2 years. Increasing the radial force of overlapping stents would be an alternative plan to help solve the problematic repeated compressible seroma despite multiple surgical treatments.

Implementation of Predictive Algorithms for the Study of the Endarterectomy LOS

Background: In recent years, the length of hospital stay (LOS) following endarterectomy has decreased significantly from 4 days to 1 day. LOS is influenced by several common complications and factors that can adversely affect the patient’s health and may vary from one healthcare facility to another. The aim of this work is to develop a forecasting model of the LOS value to investigate the main factors affecting LOS in order to save healthcare cost and improve management. Methods: We used different regression and machine learning models to predict the LOS value based on the clinical and organizational data of patients undergoing endarterectomy. Data were obtained from the discharge forms of the “San Giovanni di Dio e Ruggi d’Aragona” University Hospital (Salerno, Italy). R² goodness of fit and the results in terms of accuracy, precision, recall and F1-score were used to compare the performance of various algorithms. Results: Before implementing the models, the preliminary correlation study showed that LOS was more dependent on the type of endarterectomy performed. Among the regression algorithms, the best was the multiple linear regression model with an R² value of 0.854, while among the classification algorithms for LOS divided into classes, the best was decision tree, with an accuracy of 80%. The best performance was obtained in the third class, which identifies patients with prolonged LOS, with a precision of 95%. Among the independent variables, the most influential on LOS was type of endarterectomy, followed by diabetes and kidney disorders. Conclusion: The resulting forecast model demonstrates its effectiveness in predicting the value of LOS that could be used to improve the endarterectomy surgery planning.

Association Between Attempted Arteriovenous Fistula Creation and Mortality in People Starting Hemodialysis via a Catheter: A Multicenter, Retrospective Cohort Study

Background:

In North America, most people start hemodialysis via a central venous catheter (“catheter”). These patients are counseled to undergo arteriovenous fistula (“fistula”) creation within weeks of starting hemodialysis because fistulas are associated with improved survival.

Objectives:

To determine whether attempting to create a fistula in patients who start hemodialysis via a catheter is associated with improved mortality. We also sought to determine whether differences in baseline patient characteristics, vascular procedures for access-related complications, or days in hospital may confound or mediate the relationship between attempted fistula creation and mortality.

Design:

Multicenter, retrospective cohort study.

Setting:

Six dialysis programs located in Ontario, Alberta, and Manitoba.

Patients:

Patients aged ≥18 years who initiated hemodialysis via a catheter between January 1, 2004, and May 31, 2012, who had not had a previous attempt at fistula creation. We excluded those who had a life expectancy less than 1 year, who transitioned to peritoneal dialysis within 6 months of starting dialysis, and people who started hemodialysis via a graft.

Measurements:

Attempted fistula creation, all-cause mortality, patient characteristics and comorbidities, vascular procedures for access-related complications, and days spent in hospital.

Methods:

We used survival methods, including marginal structural models, to account for immortal time bias and time-varying confounding.

Results:

In total, 1832 patients initiated hemodialysis via a catheter during the study period and met inclusion criteria. Of these patients, 565 (31%) underwent an attempt at fistula creation following hemodialysis start. As compared to those who did not receive a fistula attempt, these people were younger, had fewer comorbidities, and were more likely to have started dialysis as an outpatient and to have received pre-dialysis care. In a marginal structural model controlling for baseline characteristics and comorbidities, attempted fistula creation was associated with a significantly lower mortality (hazard ratio [HR] = 0.53; 95% confidence interval [CI] = 0.43-0.66). This effect did not appear to be confounded or mediated by differences in the number of days spent in hospital or vascular procedures for access-related complications. It also remained similar in analyses restricted to patients who survived at least 6 months (HR = 0.60; 95% CI = 0.47-0.77) and to patients who started hemodialysis as an outpatient (HR = 0.48; 95% CI = 0.33-0.68).

Limitations:

There is likely residual confounding and treatment selection bias.

Conclusions:

In this multicenter cohort study, attempting fistula creation in people who started hemodialysis via a catheter was associated with significantly reduced mortality. This reduction in mortality could not be explained by differences in patient characteristics or comorbidities, days spent in hospital, or vascular procedures for access-related complications. Residual confounding or selection bias may explain the observed benefits of fistulas for hemodialysis access.

Trial Registration:

Not applicable (cohort study).

Sugammadex use in patients with end-stage renal disease: a historical cohort study

PURPOSE

While sugammadex (SGX) is not approved for use in patients with end-stage renal disease (ESRD), its administration in this patient population has been reported. We designed the current study to review all instances of patients with ESRD receiving SGX and to describe their clinical outcomes.

METHODS

This is a historical cohort study of 219 patients with chronic kidney disease stage 5 who received SGX in one of three hospital locations within the same academic health system. Data were collected between 7 March 2016 and 1 August 2019 and included demographics, notable events from the anesthesia records, and postoperative complications. The primary outcome included any complication possibly related to SGX such as hypersensitivity reactions, need for reintubation, hypoxemia, pneumonia, and residual neuromuscular blockade. Secondary outcomes included any other complication not included in the primary outcome and/or patient mortality within 30 days after the procedure.

RESULTS

No patient experienced a hypersensitivity reaction. Three patients required reintubation while two patients developed hypoxemia that did not require reintubation. One patient developed hospital-acquired pneumonia. Fifty (23%) patients developed other postoperative complications (different from our primary outcome) and nine patients (4%) died during the subsequent 30 postoperative days. None of the primary or secondary outcomes appeared to be related to SGX use.

CONCLUSIONS

We provide incremental evidence that SGX could be considered as an alternative neuromuscular blockade reversal agent in patients with ESRD.

The impact of pre-operative symptoms on carotid endarterectomy Outcomes: Analysis of the ACS-NSQIP carotid endarterectomy database

Carotid artery stenosis accounts for up to 20% of ischemic strokes. Since the 1950 s, one of the primary surgical treatment for this condition is carotid endarterectomy (CEA). Because of improvement of medical therapy for carotid artery atherosclerosis and the increased use of carotid artery stents, CEA is indicated if the risk of stroke and death are low. The goal of this study is to characterize the impact of pre-operative stroke and stroke risk factors on post-operative CEA patient outcomes, using the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) Targeted Vascular Module on CEA. Using the Targeted Vascular Module of the ACS-NSQIP, 22,116 patients who underwent CEA were identified from 2011 to 2016. Univariate analysis and multivariable logistic regression analyses were conducted to identify significant risk factors that predispose patients to stroke. Patients with pre-operative stroke comprise 42.1% of the group, with post-operative stroke being the second most common complication (2.1%). Pre-operative stroke patients were also at a higher risk for transient ischemic attacks, post-operative restenosis, post-operative distal embolization, and other complications. Patients with pre-operative risk factors, including stroke or stroke-like symptoms, high risk physiologic factors, high risk anatomic factors, and contralateral internal carotid artery stenosis were at a higher risk of developing post-operative stroke and other complications. Patients with these pre-operative risk factors should be closely monitored for post-operative complications in an effort to improve patient outcomes.

WavelinQ created arteriovenous fistulas versus surgical radiocephalic arteriovenous fistulas? A single-centre observational study

Purpose:

Devices to permit percutaneous endovascular arteriovenous fistula formation have recently been introduced into clinical practice with promising initial evidence. As guidelines support a distal fistula first policy, the question of whether an endovascular arteriovenous fistula should be performed as an initial option is introduced. The aims of this study were to compare a matched cohort of endovascular arteriovenous fistula with surgical radiocephalic arteriovenous fistulas.

Materials and methods:

Using data from a prospectively collected database over a 3-year period, a matched comparative analysis was performed.

Results:

WavelinQ arteriovenous fistulas (group W, n = 30) were compared with radiocephalic arteriovenous fistulas (group RC; n = 40). Procedural success was high with 96.7% for group W and 92.6% for group RC. Primary patency at 6 and 12 months was greater in group W (65.5% 6mo and 56.5% 12mo) compared to group RC (53.4% 6mo and 44% 12mo) ( p = 0.69 and 0.63). Mean primary patency was significantly lower for RC (235 ± 210 days) vs W (362 ± 240 days) ( p < 0.05). Secondary patency for group W was 75.8% and 69.5% at 6 and 12 months, respectively. Secondary patency for RC was lower at 66.7% and 57.6% at 6 and 12 months, respectively.

Conclusion:

Outcomes of WavelinQ arteriovenous fistulas in this series are similar to published results. When compared to a contemporaneously created group of surgical fistulas, WavelinQ demonstrated superior outcomes. These data would support that WavelinQ endovascular arteriovenous fistulas may be considered as a first option in the access pathway particularly if vessels at the wrist are absent or less than ideal.

Long-term Clinical Outcomes of Elective Carotid Artery Stenting in Patients Undergoing Maintenance Hemodialysis

Objective Carotid artery stenting (CAS) in patients undergoing maintenance hemodialysis is characterized by high complication rates. These patients are excluded from clinical trials of CAS. The purpose of our retrospective study was to investigate the long-term clinical outcomes of CAS in patients undergoing maintenance hemodialysis. Methods CAS was performed under local anesthesia. The technical success rate, periprocedural complications, 30-day major vascular event rate (stroke, myocardial infarction, and/or death), 3-month morbidity and mortality rates, and 5-year survival probability were investigated. Patients Nineteen patients undergoing maintenance hemodialysis were identified. Results The mean age of the patients was 69 years. Periprocedural complications occurred in two patients (confusion following CAS in one and transient hemiparesis in the other). Complete neurological recovery was achieved in both patients. No major cardiovascular events occurred within 30 days after CAS. Asymptomatic intracranial hemorrhage only occurred in one patient, and seven patients died during the follow-up period at a mean of 3.5 years after the procedure (range, 6 months to 8 years). No permanent neurologic deficit remained in the patient with intracranial hemorrhage. The causes of death were cardiovascular disease (n = 4), cancer (n = 2), and pneumonia (n = 1). No patients died of stroke. The 5-year survival probability in patients undergoing maintenance hemodialysis was 57%. Conclusion CAS in maintenance hemodialysis patients may be feasible and effective for the prevention of stroke with proper case selection, appropriate technique and strict perioperative management. The most common causes of death during the follow-up of maintenance hemodialysis patients were diseases other than stroke.

Hemodialysis access cost comparisons among incident tunneled catheter patients

Background:

Arteriovenous fistula is the ideal hemodialysis access, but most patients start with tunneled dialysis catheter. Arteriovenous fistula and arteriovenous graft surgery may reduce tunneled dialysis catheter use and also increase procedural expenses. We compared Medicare costs associated with arteriovenous fistula, arteriovenous graft, and tunneled dialysis catheter.

Methods:

Using the US Renal Data System, we identified incident hemodialysis patients in 2008 who started with tunneled dialysis catheter, survived at least 90 days, and had adequate Medicare records for analysis. We followed them until death or end of 2011; access modality was based on billing evidence of arteriovenous fistula or arteriovenous graft creation. We assumed patients without such records remained with tunneled dialysis catheter. We generated multivariate linear regression models predicting Medicare expenditures, censoring costs when patients died; we included all payments to physicians and institutions. We also created algorithms to identify access-related costs.

Results:

There were 113,505 patients in the US Renal Data System who started hemodialysis in 2008, of whom 51,002 Medicare patients met inclusion criteria. Of that group, 41,532 (81%) began with tunneled dialysis catheter; 27,064 patients were in the final analysis file. In the first 90 days after hemodialysis initiation, 6100 (22.5%) received arteriovenous fistula, 1813 (6.7%) arteriovenous graft, and 19,151 (70.8%) stayed with tunneled dialysis catheter. Annualized access costs by modality were tunneled dialysis catheter US$13,625 (95% confidence interval: US$13,426–US$13,285); arteriovenous fistula US$16,864 (95% confidence interval: US$16,533–US$17,194); and arteriovenous graft US$20,961 (95% confidence interval: US$20,967–US$21,654; p < .001). Multivariate linear regression demonstrated that staying with tunneled dialysis catheter had lowest access-related costs, arteriovenous fistula was intermediate, and those who underwent arteriovenous graft surgery were highest (p < .021). Access type was not significantly associated with total costs. Additional arteriovenous fistula and arteriovenous graft creation (US$3525 and US$3804 per access per year, respectively) and open and endovascular access-related interventions (US$3102 and US$3569 per procedure per year, respectively; all p < .001) were important predictors of increased cost.

Conclusions:

Among patients starting hemodialysis with tunneled dialysis catheter, continued tunneled dialysis catheter use is associated with lowest access-related cost. Both endovascular and open interventions are associated with significant additional costs. Further investigation is warranted to develop efficient patient-centered strategies for hemodialysis access.

Perioperative and long-term impact of chronic kidney disease on carotid artery interventions

OBJECTIVE

Chronic kidney disease (CKD) increases morbidity and mortality after vascular procedures and adversely affects late survival of patients. The presence of CKD also confers increased risk of stroke in patients with asymptomatic carotid stenosis. Patients undergoing carotid intervention in the Vascular Study Group of New England database were stratified by CKD status referable to periprocedural and late outcomes.

METHODS

All carotid artery stenting and carotid endarterectomies (CEAs) performed from 2003 to 2013 were stratified by CKD severity as mild (estimated glomerular filtration rate [eGFR] >60 mL/min/1.73 m²), moderate (eGFR 30-59), and severe (eGFR <30). The impact of CKD on outcomes of carotid procedures was evaluated using univariate and multivariate methods.

RESULTS

Of 12,568 patients identified, 11,746 (93%) underwent CEA and 822 (7%) underwent carotid artery stenting. Procedures were performed for symptomatic disease in 40%. CKD severity was mild in 58%, moderate in 35%, and severe in 7%. The 30-day stroke rate was very low across all CKD groups (1.76% mild vs 1.84% moderate and 1.34% severe; P = .009). The 30-day mortality increased with worsening renal function (0.4% mild vs 0.9% moderate and 0.9% severe; P = .01). Independent predictors of 30-day stroke or death included American Society of Anesthesiologists (ASA) class 4 or 5 (odds ratio, 2.3; 95% confidence interval [CI], 1.5-3.4; P = .0001). Multivariable Cox hazards regression showed that severe CKD (hazard ratio [HR], 1.8; 95% CI, 1.3-2.6), ASA class 4 or 5 (HR, 1.7; 95% CI, 1.3-2.2), preoperative cortical symptoms (HR, 1.5; 95% CI, 1.2-1.8), history of diabetes (HR, 1.4; 95% CI, 1.1-1.7), and age (HR, 1.03/y; 95% CI, 1.02-1.04) independently (all P < .01) predicted neurologic events or death at median follow-up of 12.7 months (interquartile range, 10.3-15.2 months). CKD did not increase the risk of neurologic events at 1-year follow-up. Predictors (P < .05) of late death included moderate CKD (HR, 1.3; 95% CI, 1.01-1.7), severe CKD (HR, 2.2; 95% CI, 1.6-2.9), ASA class 4 or 5 (HR, 1.6; 95% CI, 1.2-2.0), history of diabetes (HR, 1.4; 95% CI, 1.2-1.7), chronic obstructive pulmonary disease (HR, 1.4; 95% CI, 1.1-1.8), and cortical symptoms (HR, 1.3; 95% CI, 1.05-1.6). The 1-, 5-, and 10-year survival rates decreased with worsening renal function (log-rank test, P < .001), but patients with severe CKD maintained a 71% survival at 5 years.

CONCLUSIONS

CKD severity increases risk of perioperative mortality as well as late mortality. Patients with CKD benefit from stroke-free survival especially after CEA. Unlike patients with peripheral arterial occlusive disease, for whom severe CKD reduces median survival to ∼2.5 years, patients with CKD and carotid disease exhibit much longer survival. This suggests that carotid interventions have utility in carefully selected patients with moderate and severe CKD, particularly in symptomatic disease.

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.

Renal dysfunction and the associated decrease in survival after elective endovascular aneurysm repair

OBJECTIVE

The reported frequency of renal dysfunction after elective endovascular aneurysm repair (EVAR) varies widely in current surgical literature. Published research establishes pre-existing end-stage renal disease as a poor prognostic indicator. We intend to quantify the mortality effect associated with renal morbidity developed postoperatively and to identify modifiable risk factors.

METHODS

All elective EVAR patients with preoperative and postoperative renal function data captured by the Vascular Quality Initiative between January 2003 and December 2014 were examined. The primary study end point was long-term mortality. Preoperative, intraoperative, and postoperative parameters were analyzed to estimate mortality stratified by renal outcome and to describe independent risk factors associated with post-EVAR renal dysfunction.

RESULTS

This study included 14,475 elective EVAR patients, of whom 96.8% developed no post-EVAR renal dysfunction, 2.9% developed acute kidney injury, and 0.4% developed a new hemodialysis requirement. Estimated 5-year survival was significantly different between groups, 77.5% vs 53.5%, respectively, for the no dysfunction and acute kidney injury groups, whereas the new hemodialysis group demonstrated 22.8% 3-year estimated survival (P < .05). New-onset postoperative congestive heart failure (odds ratio [OR], 3.50; 95% confidence interval [CI], 1.18-10.38), return to the operating room (OR, 3.26; 95% CI, 1.49-7.13), and postoperative vasopressor requirement (OR, 2.68; 95% CI, 1.40-5.12) predicted post-EVAR renal dysfunction, whereas a preoperative estimated glomerular filtration rate (eGFR) ≥60 mL/min/1.73 m2 was protective (OR, 0.33; 95% CI, 0.21-0.53). Volume of contrast material administered during elective EVAR varies 10-fold among surgeons in the Vascular Quality Initiative database, but the average volume administered to patients is statistically similar, regardless of preoperative eGFR. Multivariable logistic regression demonstrated nonsignificant correlation between contrast material volume and postoperative renal dysfunction.

CONCLUSIONS

Any renal dysfunction developing after elective EVAR is associated with decreased estimated long-term survival. Protecting renal function with a rational dosing metric for contrast material linked to preoperative eGFR may better guide treatment.

Mortality and Cost of Acute and Chronic Kidney Disease after Vascular Surgery

BACKGROUND

Both acute kidney injury (AKI) and chronic kidney disease (CKD) are common yet underappreciated risk factors for adverse perioperative outcomes. We hypothesize that AKI and CKD are associated with similar increases in 90-day mortality and cost in patients undergoing major vascular surgery.

METHODS

We used multivariable regression analyses to evaluate the associations between AKI and CKD and incremental 90-day mortality and hospital cost in a single-center cohort of 3646 adult patients undergoing major vascular surgery. We defined AKI using Kidney Disease: Improving Global Outcomes criteria as change in creatinine ≥ 0.3 mg/dL or ≥ 50% increase from the reference value. CKD was determined from medical history. Regression models were adjusted for demographic and socioeconomic characteristics, comorbid conditions, surgery type, and postoperative complications.

RESULTS

The prevalence of kidney disease among vascular surgery patients is high with 49% of patients developing AKI during hospitalization and 17% presenting with CKD on admission. In risk-adjusted logistic regression analysis, perioperative AKI (odds ratio 2.2, 95% confidence interval 1.5-3.3) was the most significant predictor of 90-day mortality. The risk-adjusted average cost was significantly higher for patients with any type of kidney disease. The incremental cost of having any type of kidney disease ranged from $9100 to $19,100, even after adjustment for underlying comorbidities and other postoperative complications.

CONCLUSIONS

Kidney disease after major vascular surgery is associated with significant increases in 90-day mortality and cost with the highest risk observed among patients with AKI regardless of previous CKD.

The impact of chronic renal insufficiency on vascular surgery patient outcomes

Renal insufficiency is associated with an increased incidence of poor outcomes, including cardiovascular events and death, in the general population. Renal dysfunction appears to have a particularly negative impact in patients undergoing vascular surgery and endovascular therapy. Although the exact mechanism is unknown, increased levels of inflammatory and biochemical modulators associated with adverse cardiovascular outcomes, as well as endothelial dysfunction, appear to play a role in the association between renal insufficiency and adverse outcomes. Outcomes after the surgical and endovascular treatment of abdominal aortic aneurysms, carotid disease, and peripheral arterial disease are all negatively affected by renal insufficiency. Patients with renal dysfunction may warrant intervention for the treatment of critical limb ischemia and symptomatic carotid stenosis, given the comparatively worse outcomes associated with medical management. Open repair of aortic aneurysms and carotid intervention for asymptomatic disease in patients with severe renal dysfunction should be performed with significant caution, as the risks of repair may outweigh the benefits in this population. Further study is needed to better delineate the risks of medical management for these conditions in patients with coexisting severe renal dysfunction. Lastly, current guidelines for the management of vascular diseases, including objective performance goals for critical limb ischemia, are likely not applicable in patients with severe renal insufficiency.

The effect of chronic renal insufficiency by use of glomerular filtration rate versus serum creatinine level on late clinical outcome of carotid endarterectomy

BACKGROUND

Several studies have reported mixed results after carotid endarterectomy (CEA) in patients with chronic renal insufficiency (CRI), and we previously reported the perioperative outcome in patients with CRI by use of serum creatinine (Cr) level and glomerular filtration rate (GFR). However, only a few of these studies used GFR by the Modification of Diet in Renal Disease equation in their analysis of long-term outcome.

METHODS

During the study period, 1000 CEAs (926 patients) were analyzed; 940 of these CEAs had Cr levels and 925 had GFR data. Patients were classified into normal (GFR ≥60 mL/min/1.73 m(2) or Cr <1.5 mg/dL), moderate CRI (GFR ≥30-59 or Cr ≥1.5-2.9), and severe CRI (GFR <30 or Cr ≥3).

RESULTS

At a mean follow-up of 34.5 months and a median of 34 months (range, 1-53 months), combined stroke and death rates for Cr levels (867 patients) were 9%, 18%, and 44% for Cr <1.5, ≥1.5 to 2.9, and ≥3 (P = .0001) in contrast to 8%, 14%, and 26% for GFR (854 patients) of >60, ≥30 to 59, and <30, respectively (P = .0003). Combined stroke and death rates for asymptomatic patients were 8%, 17%, and 44% (P = .0001) for patients with Cr levels of <1.5, ≥1.5 to 2.9, and ≥3, respectively, vs 7%, 13%, and 24% for a GFR of ≥60, ≥30 to 59, and <30 (P = .0063). By Kaplan-Meier analysis, stroke-free survival rates at 1 year, 2 years, and 3 years were 97%, 94%, and 92% for Cr <1.5; 92%, 85%, and 81% for Cr ≥1.5 to 2.9; and 56%, 56%, and 56% for Cr ≥3 (P < .0001); vs 98%, 95%, and 93% for a GFR ≥60; 93%, 90%, and 86% for a GFR of ≥30 to 59; and 86%, 77%, and 73% for a GFR <30 (P < .0001). These rates for asymptomatic patients at 1 year, 2 years, and 3 years were 97%, 95%, and 93% for Cr <1.5; 94%, 87%, and 82% for Cr ≥1.5 to 2.9; and 56%, 56%, and 56% for Cr ≥3 (P < .0001); vs 98%, 95%, and 94% for a GFR ≥60; 95%, 91%, and 86% for a GFR of ≥30 to 59; and 84%, 80%, and 75% for a GFR <30 (P = .0026). A univariate regression analysis for asymptomatic patients showed that the hazard ratio (HR) of stroke and death was 6.5 (P = .0003) for a Cr ≥3 and 3.1 for a GFR <30 (P = .0089). A multivariate analysis showed that Cr ≥3 had an HR of stroke and death of 4.7 (P = .008), and GFR <30 had an HR of 2.2 (P = .097).

CONCLUSIONS

Patients with severe CRI had higher rates of combined stroke/death. Therefore, CEA for these patients (particularly in asymptomatic patients) must be considered with caution.

Impact of chronic renal insufficiency on the early and late clinical outcomes of carotid artery stenting using serum creatinine vs glomerular filtration rate

BACKGROUND

This study analyzed the impact of chronic renal insufficiency (CRI) on early and late clinical outcomes of carotid artery stenting (CAS) using serum creatinine and glomerular filtration rate (GFR).

STUDY DESIGN

There were 313 CAS patients classified into 3 groups: normal (serum creatinine <1.5 mg/dL or GFR ≥ 60 mL/min/1.73 m(2)); moderate CRI, and severe CRI (serum creatinine ≥ 3 or GFR < 30 mL/min/1.73 m(2)). Major adverse events ([MAE] stroke, death, and myocardial infarction) were compared for all groups.

RESULTS

Using serum creatinine, perioperative stroke rates for normal, moderate, and severe CRI were: 5%, 0%, and 25%, respectively, (p = 0.05) vs 4.6%, 3.7%, and 11.1%, respectively, (p = 0.44) using GFR. The perioperative MAE rates for symptomatic patients were 9.3% and 0% (p = 0.355) and 2% and 5.9% (p = 0.223) for asymptomatic patients for normal and moderate/severe CRI, respectively, using serum creatinine vs 8.1% and 7.8%, respectively, for symptomatic patients and 2.5% and 3%, respectively, for asymptomatic patients using GFR. At a mean follow-up of 21 months, late MAE rates in normal vs moderate/severe CRI patients were 8.2% and 14%, respectively, (p = 0.247) using serum creatinine vs 6.6% and 13.3%, respectively, (p = 0.05) using GFR. Late MAE rates for symptomatic patients in normal vs moderate/severe CRI were: 8.7% vs 27%, respectively, (p = 0.061) using serum creatinine and 5.7% vs 18.8%, respectively, (p = 0.026) using GFR. Late death rate was 0.55% in normal vs 7.6% (p = 0.002) for moderate/severe CRI. Freedom from MAE at 3 years in symptomatic patients was 81% in normal and 46% in moderate/severe CRI (p = 0.0198). A multivariate Cox regression analysis showed that a GFR of < 60 mL/min/1.73 m(2) had an odds ratio of 1.6 (p = 0.222) of having a MAE after CAS.

CONCLUSIONS

The GFR was more sensitive in detecting late MAE after CAS. Carotid artery stenting in moderate CRI patients can be done with a satisfactory perioperative outcome; however, late death was significant.

Preoperative estimates of glomerular filtration rate as predictors of outcome after surgery: a systematic review and meta-analysis

BACKGROUND

Kidney dysfunction is a strong determinant of prognosis in many settings.

METHODS

A systematic review and meta-analysis was undertaken to explore the relationship between estimated glomerular filtration rate (eGFR) and adverse outcomes after surgery. Cohort studies reporting the relationship between eGFR and major outcomes, including all-cause mortality, major adverse cardiovascular events, and acute kidney injury after cardiac or noncardiac surgery, were included.

RESULTS

Forty-six studies were included, of which 44 focused exclusively on cardiac and vascular surgery. Within 30 days of surgery, eGFR less than 60 m l · min · 1.73 m(-2) was associated with a threefold increased risk of death (multivariable adjusted relative risk [RR] 2.98; 95% confidence interval [CI] 1.95-4.96) and acute kidney injury (adjusted RR 3.13; 95% CI 2.22-4.41). An eGFR less than 60 ml · min · 1.73(-2) m was associated with an increased risk of all-cause mortality (adjusted RR 1.61; 95% CI 1.38-1.87) and major adverse cardiovascular events (adjusted RR 1.49; 95% CI 1.32-1.67) during long-term follow-up. There was a nonlinear association between eGFR and the risk of early mortality such that, compared with patients having an eGFR more than 90 ml · min · 1.73m(-2) the pooled RR for death at 30 days in those with an eGFR between 30 and 60 ml · min · 1.73 m(-2) was 1.62 (95% CI 1.43-1.80), rising to 2.85 (95% CI 2.49-3.27) in patients with an eGFR less than 30 ml · min · 1.73 m(-2) and 3.75 (95% CI 3.44-4.08) in those with an eGFR less than 15 ml · min · 1.73 m(-2).

CONCLUSION

: There is a powerful relationship between eGFR, and both short- and long-term prognosis after, predominantly cardiac and vascular, surgery.

In-hospital versus postdischarge adverse events following carotid endarterectomy

OBJECTIVE

Most studies based on state and nationwide registries evaluating perioperative outcome after carotid endarterectomy (CEA) rely on hospital discharge data only. Therefore, the true 30-day complication risk after carotid revascularization may be underestimated.

METHODS

We used the National Surgical Quality Improvement Program database 2005-2010 to assess the in-hospital and postdischarge rate of any stroke, death, cardiac event (new Q-wave myocardial infarction or cardiac arrest), and combined stroke/death and combined adverse outcome (S/D/CE) at 30 days following CEA. Multivariable analyses were used to identify predictors for in-hospital and postdischarge events separately, and in particular, those that predict postdischarge events distinctly.

RESULTS

A total of 35,916 patients who underwent CEA during 2005-2010 were identified in the National Surgical Quality Improvement Program database; 59% were male, median age was 72 years, and 44% had a previous neurologic event. Thirty-day stroke rate was 1.6% (n = 591), death rate was 0.8% (n = 272), cardiac event rate was 1.0% (n = 350), stroke or death rate was 2.2% (n = 794), and combined S/D/CE rate was 2.9% (n = 1043); 33% of strokes, 53% of deaths, 32% of cardiac events, 40% of combined stroke/death, and 38% of combined S/D/CE took place after hospital discharge. Patients with a prior stroke or transient ischemic attack had similar proportions of postdischarge events compared with patients without prior symptoms. Independent predictors for postdischarge events, but not for in-hospital events were female sex (stroke [odds ratio (OR), 1.6; 95% confidence interval (CI), 1.2-2.1] and stroke/death [OR, 1.4; 95% CI, 1.1-1.7]), renal failure (stroke [OR, 3.0; 95% CI, 1.4-6.2]) and chronic obstructive pulmonary disease (death [OR, 2.5; 95% CI, 1.6-3.7], stroke/death [OR, 1.8; 95% CI, 1.4-2.4], and S/D/CE [OR 1.8, 95% CI 1.4-2.3]).

CONCLUSIONS

With 38% of perioperative adverse events after CEA happening posthospitalization, regardless of symptoms status, we need to be alert to the ongoing risks after discharge particularly in women, patients with renal failure, or chronic obstructive pulmonary disease. This emphasizes the need for reporting and comparing 30-day adverse event rates when evaluating outcomes for CEA, or comparing carotid stenting to CEA.

Perioperative mortality after non-hepatic general surgery in patients with liver cirrhosis: an analysis of 138 operations in the 2000s using Child and MELD scores

INTRODUCTION

Despite of advances in modern surgical and intensive care treatment, perioperative mortality remains high in patients with liver cirrhosis undergoing nonhepatic general surgery. In the few existing articles, mortality was reported to be as high as 70% in patients with poor liver function (high Child or model for end-stage liver disease (MELD) score). Since data are limited, we analyzed our recent experience with cirrhotic patients undergoing emergent or elective nonhepatic general surgery at a German university hospital.

METHODS

Since 2000, 138 nonhepatic general surgical procedures (99 intra-abdominal, 39 abdominal wall) were performed in patients with liver cirrhosis. Liver cirrhosis was preoperatively classified according to the Child (41 Child A, 59 B, 38 C) and the MELD score (MELD median 13). Sixty-eight (49%) of the patients underwent emergent operations. Most abdominal wall operations were for hernias. Intra-abdominal operations consisted of GI tract procedures (n=53), cholecystectomies (n=15), and various others (n=31). Perioperative data were gained by retrospective analysis.

RESULTS

Overall perioperative mortality in all 138 cases was 28% (9% in elective surgery, 47% in emergent surgery; p<0.001). Perioperative mortality was higher after intra-abdominal than after abdominal wall operations (35% vs. 8%; p=0.001) or in patients requiring transfusions (43% vs. 5% without transfusions; p<0.001). Perioperative mortality increased with the Child score (10% Child A, 17% Child B, 63% Child C; p<0.01) and the MELD score (9% MELD <10, 19% MELD 10–15, 54% MELD >15; p<0.001). Univariately, further factors like American Society of Anesthesiologists (ASA) score and various preoperative laboratory values were also associated with perioperative mortality. By multivariate analysis of all 138 operations, the Child and ASA classifications, intraoperative transfusions, and a preoperative sodium <130 mmol/l, but not the MELD score, were independent prognostic factors. Analysis of elective operations revealed only a preoperatively increased creatinine as risk factor for perioperative mortality. In emergent operations again, Child class, blood transfusions, and low sodium level, but not the MELD score, predicted postoperative mortality.

CONCLUSIONS

Our results demonstrate that perioperative mortality remains high in patients with liver cirrhosisundergoing general surgery, especially in emergent situations. Patients with poor liver function and/or need for blood transfusions even had a very high mortality. In our experience, the Child score (together with other variables) independently correlates with perioperative mortality in emergent operations whereas the MELD score was inferior in predicting the outcome.

Impact of obesity on outcomes after open surgical and endovascular abdominal aortic aneurysm repair

BACKGROUND

This study examined impact of obesity on outcomes after abdominal aortic aneurysm repair.

STUDY DESIGN

Data were obtained from the Veterans Affairs National Surgical Quality Improvement Program. Body mass index (BMI) was categorized according to National Institutes of Health guidelines. Multivariate regression adjusted for 40 other risk factors to analyze trends in complications and death within 30 days.

RESULTS

We identified 2,201 patients undergoing 1,185 open and 1,016 endovascular aneurysm repairs (EVAR) for abdominal aortic aneurysms from January 2004 through December 2005. BMI distribution was identical in both groups and reflected national population statistics: approximately 30% were normal (BMI 18.5 to 24.9), 40% were overweight (25.0 to 29.9), and 30% were obese class I (30.0 to 34.9), II (35.0 to 39.9), or III (>/=40.0). After open repair, obesity of any class was independently predictive of wound complications (adjusted odds ratio = 2.4; 95% CI, 1.5 to 5.3; p = 0.002). Class III obesity was also an independent predictor or renal complications (adjusted odds rato = 6.3; 95% CI, 2.2 to 18.0; p < 0.0001) and cardiac complications (adjusted odds ratio = 4.5; 95% CI, 1.1 to 22.9; p = 0.045. After EVAR, obesity (any class) was predictive of wound complications (adjusted odds ratio = 3.1; 95% CI, 1.1 to 8.1; p = 0.026), but not predictive of other complications or death. Between the two types of operation, there were fewer complications and deaths after EVAR compared with open repair across all BMI categories, but outcomes were most disparate among the obese.

CONCLUSIONS

Obesity is an independent risk factor that surgeons should consider during patient selection and operative planning for abdominal aortic aneurysm repair. Obese patients appear to particularly benefit from successful EVAR over open repair, but if open repair is required, special attention should be paid to cardiac risk, perioperative renal protection, and aggresive wound infection prevention measures.