The Effect of Preoperative Renal Failure on Outcomes Following Infrainguinal Endovascular Interventions for Peripheral Arterial Disease

Clinical question
What is the effect of preintervention renal failure on acute outcomes after lower extremity endovascular interventions for peripheral arterial artery disease (PAD)?

Take away point
Renal failure before PAD intervention incurs greater morbidity and mortality.

Reference
Di Capua J, Reid NJ, Som A, An T, Lopez DB, So AJ, Di Capua C, and Walker GT. The Effect of Preoperative Renal Failure on Outcomes Following Infrainguinal Endovascular Interventions for Peripheral Arterial Disease. J Vasc Interv Radiol. 2021; 32:459-465. doi.org/10.1016/j.jvir.2020.10.020

Click here for abstract

Study design
Retrospective multi-center, database analysis of 6765 patients undergoing intervention for PAD.

Funding Source
No reported funding.

Setting
Multi-center database, American College of Surgery National Surgical Quality Improvement Program (ACS-NSQIP), USA.

Summary

PAD occurs at twice the rate in patients with chronic kidney disease (CKD) or end stage renal disease (ESRD), and patients with ESRD are known to suffer worse outcomes in open surgical revascularization procedures. These patients may also be at high risk for endovascular revascularization procedures. The authors performed a retrospective database analysis of 6765 adults undergoing lower extremity intervention for PAD, comparing 30-day outcomes in patients with and without preintervention renal failure.

Billing codes were used to identify patients from the ACS-NSQIP database from 2014-2017 who underwent lower extremity arterial interventions primarily including angioplasty and stent placement. Patients with missing data, ASA class 6, and those undergoing procedures as part of a transplant or trauma treatment were excluded. Patients were defined as having preintervention renal failure if they had increased BUN and creatinine on two measurements (both within 90 days of intervention with one <24 hours prior to intervention) or renal failure requiring hemodialysis, peritoneal dialysis, ultrafiltration, or hemodiafiltration <2 weeks prior to intervention.

Variables were collected before and during intervention and complications were recorded up to 30 days after intervention. Univariate analysis was performed on pre- and intraprocedure characteristics. Multivariate logistic regression identified independent risk factors for each 30-day complication adjusted for baseline characteristics. A multivariate linear regression model compared extended hospital length of stay (LOS) between groups. As a sensitivity measure, a propensity score-matched model using variables identified in the multivariate analysis was used to predict preintervention renal failure.

A total of 6765 patients met criteria with 742 patients classified as having preintervention renal failure. Renal failure patients were significantly more likely to suffer critical limb ischemia (CLI) with tissue loss, be inpatient status, undergo nonelective procedures, have diabetes, experience dyspnea, have a dependent functional status, carry cardiac comorbidities, have an open wound, receive blood products, be classified as ASA 3-5, and experience longer procedure times (p<.01).

Adjusted analyses revealed patients with preintervention renal failure were more likely to experience mortality, all cause morbidity, extended LOS > 1 day, pulmonary complication, perioperative transfusion, sepsis, reoperation, amputation, hospital readmission, major adverse cardiac event (MACE), and major adverse limb event (MALE) within the first 30 days postintervention. Of these, renal failure was an independent risk factor for mortality (OR=4.11), all cause morbidity (OR=2.03), extended LOS (OR=1.53), sepsis (OR=2.37), reoperation (OR=1.84), amputation (OR=2.74), hospital readmission (OR=1.89), MACE (OR=3.50), and MALE (OR=1.97) (p<.001). Additionally, patients with preintervention renal failure experienced a 4.2-day longer hospital stay than their counterparts. Sensitivity analysis showed no significant differences in effect sizes of cohorts, reinforcing the validity of the covariate models.

Commentary

The authors investigate outcomes in patients with and without renal failure prior to endovascular lower extremity intervention for PAD using a national surgical database. Of the recorded acute postintervention complications, the greatest increase in odds was for mortality, which agrees with mortality data from smaller studies. Additionally, there was a significantly high rate of cardiac comorbidity in patients with renal failure (8.5% vs 2.5%), as well as an independent increase in odds of postintervention MACE. Similar studies have only seen increased risk in ESRD patients (versus CKD patients), which suggests patients with dialysis-dependent renal failure may be driving the authors’ results. The third highest increased odds ratio was risk of amputation after the procedure. The authors compare this to similar surgical data, noting that some studies have only seen significance in long-term amputation rates. This implies the 30-day follow up data may be an underestimation of true risk.

In addition to the short-term follow up period, there are several other limitations to this study. Its retrospective, billing code-driven design did not allow for investigating differences among procedural techniques, and the use of a surgical database may limit the applicability of the results to interventional radiology. Also, although the authors’ aim was to specifically address preintervention renal failure, their definition of renal failure does not adhere to the diagnostic definitions of CKD or ESRD, which limits the overall generalizability and comparability of their results. Moreover, had established definitions of CKD and ESRD been used, a stratified analysis according to CKD stage could have offered additional insight into periprocedure risks, particularly when other studies that have found conflicting data in stratification analyses. The main strength of this study lies in its incredibly large sample size (n=6765), which provides a robust complement to smaller-scale data.

Overall, this large-scale, national study demonstrates that patients with preprocedural renal failure are at risk for worse outcomes compared to their nonaffected counterpart and as such, incur longer hospital stays. Interventionalists should be aware of these increased risks when offering and performing PAD interventions on this population.

Post Author
Catherine (Rin) Panick, MD
Resident Physician, Integrated Interventional Radiology
Dotter Interventional Institute
Oregon Health & Science University

@MdPanick