Endovascular aneurysm repair delivery redesign leads to quality improvement and cost reduction

Abstract

Objective

Endovascular aneurysm repair (EVAR) is now a mainstay of therapy for abdominal aortic aneurysm, although it remains associated with significant expense. We performed a comprehensive analysis of EVAR delivery at an academic medical center to identify targets for quality improvement and cost reduction in light of impending health care reform.

Methods

All infrarenal EVARs performed from April 2011 to March 2012 were identified (N = 127). Procedures were included if they met standard commercial instructions for use guidelines, used a single manufacturer, and were billed to Medicare diagnosis-related group 238 (n = 49). By use of DMAIC (define, measure, analyze, improve, and control) quality improvement methodology (define, measure, analyze, improve, control), targets for EVAR quality improvement were identified and high-yield changes were implemented. Procedure technical costs were calculated before and after process redesign.

Results

Perioperative services and clinic visits were identified as targets for quality improvement efforts and cost reduction. Mean technical costs before the intervention were $31,672, with endograft implants accounting for 52%. Pricing redesign in collaboration with hospital purchasing reduced mean EVAR technical costs to $28,607, a 10% reduction in overall cost, with endograft implants now accounting for 46%. Perioperative implementation of instrument tray redesign reduced instrument use by 32% (184 vs 132 instruments), saving $50,000 annually. Unnecessary clinic visits were reduced by 39% (1.6 vs 1.1 clinic visits per patient) through implementation of a preclinic imaging protocol. There was no difference in mean length of stay after the intervention.

Conclusions

Comprehensive EVAR delivery redesign leads to cost reduction and waste elimination while preserving quality. Future efforts to achieve more competitive and transparent device pricing will make EVAR more cost neutral and enhance its financial sustainability for health care systems.

During the last two decades, endovascular aneurysm repair (EVAR) has appropriately emerged as the first-line therapy for abdominal aortic aneurysm repair, predicated on its decreased morbidity and mortality as well as diminished length of stay (LOS). Whereas its intrinsic low-risk profile and widespread tolerability appeal to both patients and physicians alike compared with traditional open repair, EVAR remains associated with significant costs.^1–3 Given the prevalence of EVAR in contemporary practice and the current climate of increased emphasis on value-based care, efficient EVAR delivery is necessary to ensure its sustainability.

More specifically, it has been previously demonstrated that Medicare-remunerated EVAR is associated with a negative technical financial margin.³ The primary driver for this finding was the cost of stent graft implants. This accounted for more than half of procedure-associated technical costs and amounted to greater than threefold more than any other procedure-associated costs. On the basis of these findings, it is conceivable that the financial sustainability of EVAR in a value-based health care delivery system is not viable over time.

Studies in health care delivery have recently begun to critically apply lean principles for quality improvement adapted from alternative industry sectors to better evaluate processes of care for rapid identification of waste and improvement of efficiency. The purpose of this study was to perform a comprehensive analysis of EVAR delivery at a single academic medical center. Our goal was to use these techniques to identify targets for quality improvement to reduce variation and to improve efficiency while consuming fewer resources, thus increasing procedure-associated value. In doing so, we sought to eliminate intrinsic waste and care delivery inefficiency to reduce the cost of EVAR delivery at our institution.

METHODS

Subjects and setting

This study was performed at Dartmouth-Hitchcock Medical Center, a 400-bed tertiary care medical center. All patients undergoing elective, nonruptured infrarenal EVAR from April 2011 to March 2012 were identified (N = 127). All 127 cases were included for analysis of our outpatient clinic and assessment of operating room instrument utilization. In an effort to define a homogeneous cost cohort for a standardized analysis, cases were included if they met standard commercial instructions for use guidelines for all devices, used a single manufacturer’s device, and were billed using Medicare diagnosis-related group (DRG) 238 (n = 49; Fig 1). DRG 237 (with major complication) Medicare-remunerated cases were excluded as the differing reimbursement may confound technical cost analysis. This study was sanctioned by the hospital administration, and Institutional Review Board approval was waived because of the nature of data collection, which consisted of de-identified cost and instrument utilization data. Similarly, informed consent was not obtained.

Fig 1.

Flow diagram demonstrating the total number of endovascular aneurysm repairs (EVARs) studied and inclusion criteria for cost analysis. DRG, Diagnosis-related group; IFU, instructions for use.

DMAIC design

A multidisciplinary team was assembled to apply lean six sigma principles using DMAIC methodology (define, measure, analyze, improve, and control)^4,5 to identify specific targets for quality improvement and cost reduction. Comprehensive value stream maps and process flow diagrams were created to delineate processes of care surrounding EVAR delivery and to identify specific targets for quality improvement. The value stream map outlined the sequence of steps from the first clinic visit to completion of EVAR in the operating room. On the basis of these maps, potential targets for quality improvement were identified, including our outpatient clinic and associated imaging protocol, intraoperative operating room instrument usage, and price-sensitive stent graft selection. High-yield changes to our outpatient clinic/imaging protocol, instrument trays, and stent graft selection were outlined and piloted. Successful changes were thereafter widely implemented.

Outcomes

EVAR-specific data including number of clinic visits per patient, instruments used per case, and technical costs were calculated both before and after process redesign. Procedure-associated and hospital-allocated costs as well as financial revenue data were determined and adjudicated in conjunction with Dartmouth-Hitchcock Medical Center department of finance. Mean DRG 238 technical costs and revenues were used to determine the procedure-associated technical margin both before and after pricing renegotiation. EVAR stent graft implant costs were determined in collaboration with the institutional purchasing department. Additional technical cost components that were factored into this calculation included operating room resources and supplies (wires, catheters, instruments), hospital room expenses, radiology expenses, and grouped laboratory and pharmacy costs. Whereas all technical cost components represented opportunities for procedure-based savings, this analysis focused on the stent graft devices because of their disproportionate contribution to overall technical cost. Market share and device costs were determined for each of the major commercial stent graft vendors and tracked over time. LOS was benchmarked against other academic medical centers using publically available University Health System Consortium 2012 data.

RESULTS

During the 1-year study period, a total of 127 EVAR procedures met study criteria. Based on the process mapping, multiple targets for quality improvement and cost reduction were identified. Among them, preoperative outpatient clinic visits, intraoperative instrument usage, and stent graft implant pricing were identified as high-probability opportunities to effect changes and to reduce costs. A total of 49 EVAR procedures met inclusion criteria for cost analysis.

Before process redesign, 45% of outpatient EVAR consultations required additional imaging before surgery. Patients frequently presented to clinic with inappropriate studies or noncontrasted studies, often necessitating additional clinic appointments and supplemental imaging. Given the rural patient population served at our institution, this aspect of care often necessitated significant travel in addition to the burden and cost of repeated imaging studies. A preclinic imaging protocol was implemented with the administrative staff to ensure that the correct studies (computed tomography angiography including the abdomen and pelvis in patients able to tolerate administration of a contrast agent) were performed and available in our electronic medical record before the appointment, even when they were performed at outside hospitals, thereby facilitating real-time decision-making at the time of the initial clinic appointment. After implementation, the proportion of patients needing additional imaging decreased from 45% to 6%. Preoperative outpatient clinic visits were thereby reduced by 39%, from an average of 1.6 to 1.1 clinic visits per patient. During the course of 1 year, this amounted to 50 unnecessary appointments saved, creating space for new referrals while eliminating burdensome unnecessary costly travel (Fig 2).

Fig 2.

Clinic visit data before and after modifying the imaging protocol. A, The proportion of patients requiring additional imaging before and after imaging protocol redesign. B, The total number of preoperative clinic visits per patient before and after imaging protocol redesign.

The second process improvement target focused on intraoperative instrument usage. Before process redesign, 184 instruments were routinely opened for every EVAR, reflecting generic small-vessel and minor vascular equipment trays. Many of the instruments opened were rarely or never used during the course of the operation. Accordingly, a piloted streamlined tray specifically reflecting the equipment needs of EVAR with fewer instruments was implemented, decreasing turnover and sterilization burden. Instrument tray redesign successfully reduced instrument use by 32% (184 vs 126 instruments). This corresponds to a decrease in instrument cost per case from $230 to $157.50, saving more than $8000 annually. Of note, the streamlined instrument tray was applicable for a wide spectrum of alternative vascular procedures, with projected additional savings of more than $50,000 annually (Fig 3).

Fig 3.

Instrument usage data before and after modifying the instrument trays. A, The number of instruments opened per case before and after process redesign. B, Instrument cost per case before and after process redesign.

Mean EVAR technical costs were $31,672, with endograft implants accounting for 52%. Pricing redesign was undertaken in collaboration with hospital purchasing and graft vendors to facilitate device cost reduction and pricing transparency. Stent graft prices were reviewed by the faculty and trainees, and the least expensive stent grafts were chosen when any stent graft would have been appropriate. This awareness successfully reduced mean EVAR technical costs from $31,672 to $28,607, yielding a 10% reduction in overall cost, with endograft implants accounting for 46% after intervention (Fig 4).

Fig 4.

Endovascular aneurysm repair (EVAR) technical margin outcomes. The graph depicts the 10% reduction in mean EVAR-associated technical costs before and after process redesign.

As a proxy for quality benchmarking, we monitored EVAR LOS. In 2012, LOS for DRG 238 was in the lowest quartile nationally when it was benchmarked against other comparable institutions using publically available University Health System Consortium data. LOS for DRG 238 remained in the lowest quartile in 2014, suggesting that LOS was not significantly affected by the changes in care delivery. Whereas LOS is not ideally suited to quantify the impact of this quality improvement project, it is an important barometer of efficient hospital-based care delivery.

DISCUSSION

This study demonstrates the potential impact of industry-derived lean six sigma quality improvement principles when they are applied to complex vascular health care delivery. Lean and six sigma methodologies, although commonly used in manufacturing to improve productivity and to reduce variation, have been applied to health care settings.^5–7 Such techniques can identify multiple opportunities to eliminate waste, to reduce cost, and thereby to facilitate more nimble, sustainable care. This has emerged as particularly important given the dramatic rise in health care spending during the last several decades in the United States, which is widely regarded as unsustainable.⁸ Clearly, the ideal treatment strategy for aneurysm disease must be evidence based and provide value: high quality at a reasonable price point. Although, in the past, focus has been on proof of concept, efficacy, and safety of EVAR, there has been a transition to a new era in health care in which efficient delivery of medical interventions is critical for sustainable care. Accordingly, the aim of our study was to use lean six sigma techniques to identify high-yield changes to streamline our EVAR delivery process and to reduce costs.

Several series have documented that despite the multiple advantages of EVAR over open abdominal aortic aneurysm repair, the cost of EVAR remains high largely because of procedure-associated costs.^1,9,10 We have previously published that the margin for DRG 238 Medicare-remunerated EVAR is substantially negative at our institution, costing approximately $500,000 per year.³ By use of a DMAIC-based approach, multiple targets were selected for study and intervention. Addressing inefficiencies in the clinic, perioperative instrument handling, and device selection had demonstrable results and reduced overall technical costs by 10%.

Surprisingly, at the start of the study period, stent graft vendor market share did not correlate with graft price at our institution. Initially, more expensive vendors paradoxically derived the largest market share early in the study, reflecting a historical paucity of pricing into device selection and case planning. By increasing the surgeons’ awareness of graft price differential to consider device costs during case planning when various commercial vendor products could be used interchangeably, market share shifted (Fig 5). In addition, transparent informed pricing negotiation with commercial vendors facilitated stent graft price reduction, thereby augmenting the device-realized savings over time. Both physician behavior and vendor pricing renegotiation complement one another synergistically to achieve optimal cost reduction. Recognizing the limitations of current DRG-based remuneration, informed collaborative pricing with industry represents a high-yield opportunity to derive substantial procedure-associated cost reduction, thereby potentially minimizing negative financial margins incurred by medical device-dependent procedures. Thus, the application of lean quality improvement principles to health care delivery can lead to tangible cost reduction and long-term procedure solvency for tertiary care referral centers.

Fig 5.

Shifts in vendor market share during the course of the study due to the surgeon’s increased awareness of stent graft cost and factoring of device cost into case planning. Each letter represents a different vendor. Over time, vendor A, the most expensive of the stent grafts, derived a smaller segment of the market share.

This study has several intrinsic limitations. First, this study may not be broadly generalizable as processes of care reflect a single institution and the results are applicable only to cases that met the instructions for use criteria for all commercial devices. Use of devices in an off-label fashion may potentially confound our cost analysis as these cases usually represent more complex anatomy, thus requiring additional stent graft components. Second, device costs and DRG-related reimbursements can vary substantially by institution and region. Nevertheless, we believe that similar trends in EVAR-related costs and care delivery are prevalent among large institutions and that similar implemented measures may reduce waste, leading to more efficient patient care and physician satisfaction. In addition, current health care policy offers little incentive for widespread adoption and application of such measures to local practice. Nevertheless, the realized savings and gained efficiency in care delivery demonstrated herein argue for alignment of incentives to support value-based initiatives to sustain health care organizations.

CONCLUSIONS

Comprehensive EVAR delivery redesign using lean six sigma and DMAIC-based principles leads to overall cost reduction and improved efficiency with fewer clinic visits and streamlined instrument trays. Competitive device pricing helps offset the negative margin incurred by EVAR through vendor contract renegotiation and practice modification to incorporate device costs into case planning paradigms.

DMAIC-based quality improvement provides tangible increased value for patients undergoing EVAR. Opportunities for quality improvement in care delivery can be implemented without compromising quality and serve as a proxy for other high-cost device-dependent procedures as a means to preserve sustainable tertiary care to large populations.