Outcomes after carotid artery stenting in hemodialysis patients

What Is the Role of Transcarotid Artery Revascularization?

Carotid endarterectomy (CEA) is the gold-standard method of carotid revascularization in symptomatic patients with ≥50% and in asymptomatic patients with ≥70% stenosis. Transfemoral carotid artery stenting (TFCAS) has been associated with higher perioperative stroke rates compared to CEA in several studies. On the other hand, transcarotid artery revascularization (TCAR) has outperformed TFCAS in patients who are considered high risk for surgery. There is increasing data that supports TCAR as a safe and efficient technique with outcomes similar to those of CEA, but additional level-one studies are necessary to evaluate the long-term outcomes of TCAR in high- and standard-risk patients.

TransCarotid Artery Revascularization Can Be Safely Performed in Patients Undergoing Dialysis

BACKGROUND

TransCarotid Artery Revascularization (TCAR) has been effectively performed to prevent stroke in patients with carotid artery stenosis (CS). Prior studies established that TCAR can be safely performed in high-risk patients such as octogenarians, patients with prior carotid endarterectomy (CEA), contralateral occlusion, and heavily calcified lesions. Hemodialysis patients are at an increased risk of exhibiting cardiovascular complications. This study aims to investigate how dialysis may affect TCAR outcomes.

METHODS

The Vascular Quality Initiative (VQI) dataset was queried for patients undergoing TCAR from November 2016 to November 2021. Patients were divided into dialysis and nondialysis groups. The primary outcome was the composite endpoint of in-hospital stroke, death, or myocardial infarction (MI). Secondary outcomes were in-hospital stroke, stroke, or transient ischemic attack (TIA), death, prolonged length of stay (more than 1 day) (PLOS), MI, and stroke or death. Multivariable logistic regression analysis was used to assess in-hospital outcomes. Kaplan-Meier survival and log-rank test were used to assess 1-year survival.

RESULTS

A total of 22,619 patients underwent TCAR during the study period. Of these, 327 patients were undergoing dialysis. On univariable analysis, dialysis patients were associated with a higher risk of mortality compared to nondialysis patients (1.2% vs. 0.6%, P = 0.030). However, after adjusting for potential confounders, this difference did not persist (odd ratio [OR]: 1.99, 95% confidence interval [CI] (0.8-4.9), P = 0.136). Dialysis patients were more likely to experience PLOS (OR: 1.6, 95% CI (1.2-2), P < 0.001). There was no difference between dialysis and nondialysis patients in the risk of stroke or death, stroke, stroke or TIA, MI, and stroke or death, or MI on univariable and multivariable analyses. At 1 year, the overall survival for dialysis versus nondialysis patients was 81.5% vs. 95.5%, P < 0.001.

CONCLUSIONS

To our knowledge, this is the first study to date of dialysis patients who have undergone TCAR. We have shown that there was no difference in the risk of stroke, death, and MI between dialysis and nondialysis patients. Therefore, TCAR can be safely offered to patients undergoing dialysis. Future studies with larger number of patients are warranted to confirm these results.

Changes in cerebral oxygenation during hemodialysis before and after carotid artery stenting

A 68-year-old man received hemodialysis (HD) for the treatment of end-stage renal failure for 6 years. Five years prior to carotid artery stenting (CAS), a neck ultrasound performed to screen for carotid atherosclerosis revealed an asymptomatic right internal carotid artery stenosis. One month prior, the stenotic lesion progressed to 74% by cerebral angiography; therefore, CAS was performed. To evaluate the influence of right internal carotid artery stenosis on the intradialytic cerebral circulation and oxygenation, cerebral regional oxygen saturation (rSO₂) at bilateral forehead was measured using the INVOS 5100c oxygen saturation monitor (Covidien Japan, Japan) during HD before and after CAS. Before CAS, right cerebral rSO₂ was maintained during HD, whereas left cerebral rSO₂ gradually increased from the initiation to end of HD. However, the differences of intradialytic cerebral rSO₂ changes between bilateral sides disappeared after CAS. In the present case, before CAS, the intradialytic increase in left cerebral rSO₂ might reflect the increase in the left cerebral blood flow to compensate for the ultrafiltration-associated decreases in the right cerebral blood flow and perfusion pressure. Furthermore, the preserved right cerebral rSO₂ before CAS might reflect the mechanism maintaining the right cerebral blood flow from the collateralized circle of Willis during HD. Throughout our experience, cerebral oxygenation monitoring during HD might disclose intradialytic changes in cerebral blood flow distribution between the ipsilateral and contralateral side in HD patients with carotid artery stenosis.

Outcomes of Carotid Revascularization in the Treatment of Restenosis After Prior Carotid Endarterectomy

BACKGROUND AND PURPOSE

Restenosis after carotid endarterectomy (CEA) is associated with an increased risk of ipsilateral stroke. The optimal procedural modality for this indication has yet to be determined. Here, we evaluate the in-hospital outcomes of transcarotid artery revascularization (TCAR), redo-CEA, and transfemoral carotid artery stenting (TFCAS) in a large contemporary cohort of patients who underwent treatment for restenosis after CEA.

METHODS

We performed a retrospective analysis of all patients in the vascular quality initiative database who underwent TCAR, redo-CEA, or TFCAS after ipsilateral CEA between September 2016 and April 2020. Patients with prior ipsilateral CAS were excluded from this analysis. In-hospital outcomes following TCAR versus CEA and TCAR versus TFCAS were evaluated using multivariate logistic regression analysis.

RESULTS

A total of 4425 patients were available for this analysis. There were 963 (21.8%) redo-CEA, 1786 (40.4%) TFCAS, and 1676 (37.9%) TCAR. TCAR was associated with lower odds of in-hospital stroke/death (odds ratio [OR], 0.41 [95% CI, 0.24-0.70], P=0.021), stroke (OR, 0.46 [95% CI, 0.23-0.93], P=0.03), myocardial infarction (MI; OR, 0.32 [95% CI, 0.14-0.73], P=0.007), stroke/transient ischemic attack (OR, 0.42 [95% CI, 0.24-0.74], P=0.002), and stroke/death/MI (OR, 0.41 [95% CI, 0.24-0.70], P=0.001) when compared with redo-CEA. There was no significant difference in the odds of death between the 2 groups (OR, 0.99 [95% CI, 0.28-3.5], P=0.995). TCAR was also associated with lower odds of stroke/transient ischemic attack (OR, 0.37 [95% CI, 0.18-0.74], P=0.005) when compared with TFCAS. There was no significant difference in the odds of stroke, death, MI, stroke/death, or stroke/death/MI between TCAR and TFCAS.

CONCLUSIONS

TCAR was associated with significantly lower odds of in-hospital stroke, MI, stroke/transient ischemic attack, stroke/death, and stroke/death/MI when compared with redo-CEA and lower odds of in-hospital stroke/transient ischemic attack when compared with TFCAS. Additional long-term studies are warranted to establish the role of TCAR for the treatment of restenosis after CEA.

Perioperative outcomes for carotid revascularization on asymptomatic dialysis-dependent patients meet Society for Vascular Society guidelines

OBJECTIVE

The current Society for Vascular Surgery practice guidelines recommend carotid revascularization for asymptomatic disease in patients with at least a 3-year life expectancy and stenosis >60% when the expected perioperative stroke and death rate is <3%. Based on this recommendation, it was previously determined that asymptomatic patients who require dialysis would not meet the perioperative stroke and death thresholds nor the long-term survival benchmarks to justify carotid surgery. To determine whether carotid surgery for patients requiring dialysis is appropriate, the present study compared the perioperative outcomes after carotid revascularization for dialysis-dependent patients relative to nondialysis patients in a contemporary, national cohort.

METHODS

The targeted vascular module from the American College of Surgeons National Surgical Quality Improvement Program was queried to identify patients who undergone carotid endarterectomy or carotid artery stenting for asymptomatic carotid disease from 2011 to 2018. The cohort was categorized as requiring or not requiring dialysis. The primary 30-day outcomes included mortality and the composite of stroke/death and stroke/death/myocardial infarction (MI). Univariate analyses were performed using the Fisher exact test and Wilcoxon rank sum test. Multivariable analyses were used to assess the independent associations of the estimated glomerular filtration rate and dialysis dependence with the stroke/death rate.

RESULTS

A total of 17,579 patients met the inclusion criteria. Of these patients, 226 (1.3%) required dialysis at revascularization. No difference was found in the degree of severe stenosis (80%-99%) demonstrated by 69% of the dialysis cohort and 72% of the nondialysis cohort (P = .9). Of the dialysis and nondialysis cohorts, 5% and 3.6% underwent carotid artery stenting (P = .3). The dialysis-dependent patients were younger (68 vs 71 years; P < .001) and were more likely to have insulin-dependent diabetes (47% vs 12%; P < .001), congestive heart failure (8.4% vs 1.4%; P < .001), and severe chronic obstructive pulmonary disease (15% vs 10%; P = .03). In the dialysis and nondialysis cohort, 2 (0.9%) and 88 (0.5%) patients died (P = .3); 4 (1.8%) and 247 (1.4%) experienced strokes (P = .6); and 3 (1.3%) and 185 (1.1%) patients experienced MI (P = .5), respectively. The composite outcomes of stroke/death and stroke/death/MI was 2.2% (n = 5) and 1.8% (n = 319; P = .6) and 3.5% (n = 8) and 2.8% (n = 479; P = .4) in the dialysis and nondialysis cohorts, respectively. After multivariable analysis, neither the estimated glomerular filtration rate (adjusted odds ratio, 1.0; 95% confidence interval, 1.00-1.01; P = .26) nor dialysis dependence (adjusted odds ratio, 0.21; 95% confidence interval, 0.03-1.57; P = .13) was independently associated with the composite outcome of stroke/death.

CONCLUSIONS

The 30-day carotid revascularization outcomes for asymptomatic disease in dialysis-dependent patients met the Society for Vascular Surgery guidelines in this national cohort and might be better than previously surmised. Hence, vascular surgeons could consider carotid revascularization for select dialysis-dependent patients with the appropriate expected longevity and perioperative risk.

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.

Infrainguinal bypass surgery outcomes are worse in hemodialysis patients compared with patients with renal transplants

OBJECTIVE

Studies of infrainguinal bypass surgery (IBS) in patients with end-stage renal disease have focused on hemodialysis (HD) patients. Little is known of the applicability of their outcomes to patients with renal transplants (RTs). In this study, we sought to compare perioperative and long-term outcomes of IBS in a large population-based cohort of HD and RT patients.

METHODS

A retrospective review of all HD and RT patients who underwent IBS between January 2007 and December 2011 in the U.S. Renal Data System was performed. Univariable, Kaplan-Meier, multivariable logistic, and Cox regression analyses were employed to evaluate 30-day postoperative (graft failure, limb loss, conduit infection, death) and long-term (primary patency [PP], primary assisted patency [PAP], secondary patency [SP], limb salvage, mortality) outcomes.

RESULTS

There were 10,787 IBSs performed in 9739 (90%) HD patients and 1048 (10%) RT patients who presented predominantly with critical limb ischemia (72%). Bypass configurations were femoral-popliteal (48%), femoral-tibial (34%), and popliteal-tibial (18%). Comparing HD vs RT patients, PP, PAP, and SP were 18% vs 33%, 23% vs 38%, and 30% vs 48%, respectively, at 5 years among autogenous conduit recipients (all P < .001) and 20% vs 28% (P = .02), 23% vs 31% (P = .02), and 33% vs 53% (P < .001) among prosthetic conduit recipients. Limb salvage and patient survival were 39% vs 56% and 19% vs 48%, respectively, at 5 years (all P < .001). Risk-adjusted analyses demonstrated higher PP (adjusted hazard ratio [aHR], 1.32; 95% confidence interval [CI], 1.20-1.45; P < .001), PAP (aHR, 1.32; 95% CI, 1.19-1.45; P < .001), SP (aHR, 1.47; 95% CI, 1.31-1.65; P < .001), limb salvage (aHR, 1.48; 95% CI, 1.30-1.67; P < .001), and patient survival (aHR, 2.42; 95% CI, 2.17-2.71; P < .001) for RT compared with HD patients.

CONCLUSIONS

The HD-dependent state is associated with elevated bypass and patient-level risks after IBS compared with patients with RTs. These results show that the benefits of renal transplantation likely extend to infrainguinal bypass-specific outcomes. The estimates of risk reported herein should inform the patient's and provider's expectations at the point of care.

External Validation of Randomized Trial Outcomes Following Carotid Interventions in the Modern Era

An essential prerequisite of randomized controlled trials (RCTs) is “external validation,” that is, results obtained in the “real world” closely replicate those from RCTs. In this respect, contemporary administrative data set registries reporting outcomes after carotid endarterectomy and carotid artery stenting (CAS) have recently reported death/stroke rates that exceed the accepted risk thresholds for intervening. The current article evaluates this controversy and offers reasons why this might continue to happen, namely: (1) difference in interventionists’ competence/experience, (2) patient selection, and (3) advances in CAS technology/technique. As CAS is a continuously evolving technique, the results obtained from patients recruited into the landmark RCTs (as early as the late 1990s) do not reflect contemporary practice. Although RCTs are not always the perfect solution, the process of randomization ensures minimization of selection bias. A possible way forward may be the introduction of prospective, randomized, controlled clinical registries.

Long-term outcomes after autogenous versus synthetic lower extremity bypass in patients on hemodialysis

BACKGROUND

Hemodialysis dependence confers unique physiologic conditions. Prior reports of outcomes after infrainguinal open bypass operations in patients on hemodialysis have been based on relatively small sample institutional series. In this study, we evaluate long-term outcomes after open bypass operations in a large contemporary population-based cohort of hemodialysis patients. We studied all hemodialysis patients who underwent infrainguinal open operation using autogenous versus prosthetic conduits in the United States Renal Data System between January 2007 and December 2011.

METHODS

Univariate methods (χ², analysis of variance) were used to compare the characteristics of the patient and type of bypass. Kaplan-Meier, univariate and multivariate logistic, and Cox regression analyses were used to evaluate 30-day postoperative outcomes as well as patency, limb salvage, and mortality in the long term.

RESULTS

There were 9,739 (autogenous: 59%, prosthetic: 49%) infrainguinal open bypass operations performed in this cohort. Of these, 4,717 (48%) were femoral-popliteal, 3,321 (34%) were femoral-tibial, and 1,701 (18%) were popliteal-tibial bypasses. Bypass operations were performed most commonly for critical limb ischemia (72%). Primary patency was 18% for both types of conduits at 5 years (P = .16). Comparing autogenous versus prosthetic conduits, primary-assisted patency was 23% vs 20% at 5 years (P = .98), while secondary patency was 30% for both conduits at 5 years (P = .05). Limb salvage was 35% vs 41% at 5 years (P < .001). Multivariable analyses demonstrated greater patency (adjusted hazard ratio [aHR]: 1.16; 95% confidence interval, 1.05-1.28; P = .003) and limb salvage (aHR: 1.12; 95% confidence interval, 1.01-1.24; P = .03) for autogenous compared to prosthetic bypasses. The advantage conferred by autogenous conduits was most clinically relevant for femoral-tibial (aHR: 1.34; 95% confidence interval, 1.17-1.55; P < .001) and popliteal-tibial (aHR: 1.55; 95% confidence interval, 1.09-2.21; P = .014) configurations.

CONCLUSION

This large study evaluated the long-term outcomes of open bypass operations in patients on hemodialysis. The data confirm the long-term benefits of autogenous conduits compared with prosthetic conduits in this high-risk population of patients, especially for the treatment of distal lesions. Individual patient life expectancy, availability of adequate autogenous conduit options, indication for operation, level of disease, as well as potential need for future options for additional access for dialysis should be taken into consideration when deciding to construct an open bypass in a hemodialysis patient.