Characterizing Reimbursements for Medicare Patients Receiving Endovascular Abdominal Aortic Aneurysm Repair at Vascular Quality Initiative Centers

Capturing the Complexity of Open Abdominal Aortic Surgery in the Endovascular Era

OBJECTIVE

Volume and quality benchmarks for open abdominal aortic surgery and particularly open aortic aneurysm repair (OAR) in the endovascular era are guided by the Society for Vascular Surgery (SVS) guidelines, but the Vascular Quality Initiative (VQI) OAR module fails to capture the full spectrum of complex OAR. We hypothesized that VQI-ineligible complex OAR is the dominant form of open repairs performed at a VQI-participating tertiary center.

METHODS

All OAR cases performed at a single tertiary care center from 2007 to 2020 were reviewed. The VQI OAR criteria were applied with exclusions (non-VQI) defined as concomitant renal bypass, clamping above the superior mesenteric artery (SMA) or celiac artery, repairs performed for trauma, anastomotic aneurysm, isolated iliac aneurysm, or infected aneurysms. Linear regression was used to assess temporal trends.

RESULTS

Among a total of 481 open abdominal aortic operations, 355 (74%) were OAR. The average annual OAR volume remained stable over 14 years (25 ± 6; P = .46). Non-VQI OAR comprised 54% of all cases and persisted over time (R² = .047, P = .46). Supra-celiac clamping (35%) was often necessary. The proportion of endograft explantation cases significantly increased over time from 4% in 2007 to 20% in 2019 (P = .01). Infectious indications represented 20% (n = 70) of cases. Visceral branch grafts were performed in 16% of all cases. OAR for ruptured aneurysm constituted 10% of cases. Thirty-day mortality was significantly higher in non-VQI vs. VQI-eligible OAR cases (10% vs. 4%; P = .04).

CONCLUSIONS

Complex OAR comprises a majority of OAR cases in a contemporary tertiary referral hospital, yet these cases are not accounted for in the VQI. Creation of a "complex OAR" VQI module would capture these cases in a quality-driven national registry and help to better inform benchmarks for volume and outcomes in aortic surgery.

Validation of an indirect linkage algorithm to combine registry data with Medicare claims

INTRODUCTION

Linkage of registries to Medicare claims data can help extend follow-up for patients receiving medical devices. This study sought to test and validate an algorithm that does not require patient identifiers to link a national vascular registry and Medicare claims data.

METHODS

We used data from the Vascular Quality Initiative (VQI), a registry capturing data from more than 600 centers on several different vascular procedures and Medicare claims from 2003 to 2018. We restricted to patients aged 65 years and older who had fee-for-service entitlement at the time of the procedure for this study. We performed an indirect linkage to combine VQI with Medicare at the patient level using a sequential algorithm based on patient's date of birth, sex, zip code, procedure date, and procedure facility. We compared this against a gold standard of a cohort directly linked using social security numbers (SSNs). We calculated the matching rate and accuracy overall, and before and after October 2015 when the ICD-10 system was adopted in the US.

RESULTS

A total of 144,045 VQI-Medicare linked patients were in the gold standard cohort. Using the indirect linking algorithm, we matched 133,966 of the 144,045 VQI patients to their Medicare claims (matching rate: 93.0%). Among these, 133,104 patients were correctly matched (matching accuracy: 99.4%). The matching rate was higher when the indirect linkage was implemented in ICD-10 coded data than in ICD-9 coded data (94.0% vs. 92.2%). Accuracy of the indirect linkage remained high for all procedure modules post-ICD-10 coding change (overall 99.4%, range 99.0-99.7%).

CONCLUSION

In this study, we successfully used indirect identifiers to link the VQI to Medicare claims with more than 90% success and more than 99% accuracy. When direct linkage of registry-claims data using SSNs is not possible because of availability, confidentiality, or both, this method for indirect linkage provides a suitable alternative. The matching rate and accuracy help ensure the accuracy of long-term follow-up and the completeness and representativeness of linked databases for relevant research and quality improvement initiatives.

Procedure-Associated Costs and Mid-Term Outcomes of Endovascular Zone 0 and Zone 1 Aortic Arch Repair

BACKGROUND

Thoracic endovascular aortic repair (TEVAR) of proximal aortic arch pathology provides a less-invasive treatment option for high-risk patients ineligible for open arch reconstruction. However, the fiscal impact of these techniques remains unclear. Therefore, our objective was to characterize the mid-term outcomes after Zone 0 and Zone 1 TEVAR and describe the associated technical costs, revenues, and net margins at a single tertiary medical center.

METHODS

We examined all patients who underwent TEVAR between April 2011 and August 2019 via retrospective chart review. Patients were categorized by proximal endograft extent to identify Zone 0 or Zone 1 repairs. Procedural characteristics and outcomes were described. Technical costs, revenues, and margins were obtained from the hospital finance department.

RESULTS

We identified 10 patients (6 Zone 0, 4 Zone 1) who were denied open arch reconstruction. Patients were predominantly female (n = 8; 80%) and the mean age was 72.8 ± 5.5 years. TEVAR was performed in 5 asymptomatic patients, urgently in 3 symptomatic patients, and emergently in 2 ruptured patients. TEVAR plus extra-anatomic bypass was performed in 4 patients. Another 4 patients also received parallel stent-grafting while 1 patient received a branched thoracic endograft and yet another an in-situ laser fenestration followed by branch stent grafting. Within the 30-day postoperative period, 1 patient experienced stroke and 1 patient died. Bypass and branch vessel patency were 100% through the duration of follow-up (mean 19.3 months). Mean total technical cost associated with all procedures or repair stages was $105,164 ± $59,338 while mean net technical margin was -$25,055 ± $18,746. The net technical margin was negative for 9 patients.

CONCLUSIONS

Endovascular repair of the proximal aortic arch is associated with good mid-term outcomes in patients considered too high-risk for open repair. However, reimbursement does not adequately cover treatment cost, with net technical margins being negative in nearly all cases. To remain financially sustainable, efforts should be made to both optimize aortic arch TEVAR delivery as well as advocate for reimbursement commensurate with associated costs.