Inpatient Costs of Routine Endovascular Repair ofAbdominal Aortic Aneurysm1
Jessica S. Lester, MM, Johanna L. Bosch, PhD, John A. Kaufman, MD, Elkan F. Halpern, PhDG. Scott Gazelle, MD, MPH, PhD
Rationale and Objectives. The purpose of this study was to determine the inpatient cost of routine (ie, without emergentconversion to open repair during the hospital stay) endovascular stent-graft placement in a consecutive series of patientsundergoing elective endovascular repair of abdominal aortic aneurysm (AAA) at a single institution.
Materials and Methods. Inpatient hospital costs of 91 patients who underwent initial elective endovascular repair ofAAA were analyzed retrospectively. All patients had participated in clinical trials at the authors institution during theprevious 6 years. Financial data were derived from the hospitals cost-accounting system; additional procedural data werecollected from a departmental database and with chart review. Stent-graft and professional costs were excluded.
Results. The mean total cost for endovascular repair was $11,842 (standard deviation [SD], $5,127), mean procedure timewas 149 minutes (SD, 79 minutes), and mean length of stay was 3.5 days (SD, 2.3 days). Total cost depended on stent-graft type (means, $12,428 [bifurcated] vs $9,622 [tube]; P .0002) and strongly correlated with procedure time andlength of hospital stay (r 0.78 and 0.66, respectively; P .0001). Ninety-six percent of total costs for all patients wereattributable to the following departments: operating theater (31%), radiology (31%), nursing (22%), and anesthesia (12%).
Conclusion. Overall costs are greater with bifurcated than with tube stent-grafts. Total procedure-related costs are dividedrelatively equally between the operating theater, the radiology department, and the combination of the nursing and anes-thesia departments.
Key Words. Aortic aneurysm, abdominal; hospital costs; stents
The U.S. Food and Drug Administration first approvedstent-grafts for elective endovascular repair of abdominalaortic aneurysms (AAA) in September 1999. Clinical tri-als of stent-grafts are essential to receiving approval fromthe U.S. Food and Drug Administration, and such trialsare ongoing, with new approvals likely to be forthcoming.
Preliminary clinical evaluation of the new procedure sug-gests that it may be as effective asand less invasivethanopen surgical repair. To evaluate this new technol-ogy more fully, however, and to understand the full im-pact of its use on the health care system in particular, it isimportant to understand not only the associated healthbenefits but also the economic costs.
Cost studies of the traditional, open surgical techniqueare abundant in the literature (118). To our knowledge,nine published studies have analyzed the costs of the al-ternative stent-graft procedure (1220). Additional dataare needed, however, to build on this previous work andto address the potential limitations of these earlier studies.For example, four studies (1215) based their results onsmall sample sizes (n 22). Three studies (16,17,20)compared the costs of endovascular repair with those of
Acad Radiol 2001; 8:639646
1 From the Decision Analysis and Technology Assessment (DATA) Group,Department of Radiology, Massachusetts General Hospital and HarvardMedical School, Zero Emerson Place, Ste 2H, Boston, MA 02114 (J.S.L.,J.L.B., J.A.K., E.F.H., G.S.G.); the Department of Health Policy and Man-agement, Harvard School of Public Health, Boston, Mass (G.S.G.); and theDepartment of Epidemiology and Biostatistics, Erasmus University MedicalCenter, Rotterdam, the Netherlands (J.L.B.). Received January 15, 2001;revision requested January 31; revision received March 5; accepted March7. Address correspondence to G.S.G.
open surgery, but absolute cost figures were not pre-sented. The remaining two studies (18,19) did not useprimary cost data. One of these two studies (18) calcu-lated cost data on the basis of average resource use asreported in the literature, and the other (19) estimatedcosts by converting charges found in the Health Care Fi-nancing Administrations Medicare Provider Analysis andReview (MEDPAR) database with the use of cost-to-charge ratios (21).
The purpose of this study was to determine the inpa-tient cost of routine (ie, without emergent conversion toopen repair during the hospital stay) endovascular stent-graft placement in a consecutive series of patients under-going elective endovascular repair of AAA at a singleinstitution. The analysis focused on the cost of the princi-pal hospital stay and did not include preadmission orpostdischarge costs, device costs, or professional fees.Our analysis was conducted with primary cost data, pro-vided estimates in terms of real-dollar figures, and used arelatively large patient cohort as the study group.
MATERIALS AND METHODS
Patient Population and Procedure
Our study group included consecutive patients enrolledin all clinical trials involving AAA repair with bifurcatedor tube stent-grafts, such as the Ancure (Guidant/Endo-Vascular Technology, Menlo Park, Calif), Vanguard(Boston Scientific/Medi-tech, Wayne, NJ), and Excluder(W.L. Gore & Associates, Flagstaff, Ariz) devices, at asingle, large, urban teaching hospital between October1994 and October 1999. Internal Review Board approvaland informed consent were obtained for all patients inthese trials and for the retrospective use of patient infor-mation in this study. None of the trials was consideredhigh risk or compassionate use during this time period;thus, all patients were also surgical candidates. The twomost important inclusion criteria of the clinical trials wereappropriate anatomy for the dimensions of the device andabsence of exclusionary, comorbid medical conditions,such as renal failure, metastatic carcinoma, or uncorrect-able coagulopathy. Selection criteria for endovascular ver-sus traditional repair were at the discretion of the refer-ring surgeon, provided that the patient met the inclusioncriteria of the clinical trial. Once a patient was acceptedinto a trial, the device configuration was chosen solely onthe basis of the patients anatomy and on the availabilityof device itself within the trial (22).
Ninety-one patients were included in our study andselected from a total of 99 consecutive patients. Six ofthe 99 patients were excluded from our analysis due tomissing data or unresolvable inconsistencies in the data(eg, dates of hospital stay not matching date of the proce-dure performed, cost fields left blank), which caused us toquestion the validity of some (or all) of the data for thatpatient. Two patients who required immediate conversionduring the procedure to open surgical repair also wereexcluded. Of the final 91 patients included in our study,19 (21%) underwent tube and 72 (79%) underwent bifur-cated stent-graft placement. Sixty-eight (75%) patientswere men, 85 (93%) were white, and the mean patientage was 75 years (standard deviation [SD], 7.5 years; agerange, 5191 years). Twenty-two patients (24%) under-went stent-graft placement with regional anesthesia; theother 69 patients (76%) were treated under general anes-thesia.
The procedure was performed on the day of or the dayafter hospital admission. Bilateral femoral artery cut-downs were performed in all patients scheduled to un-dergo bifurcated stent-graft placement, and ipsilateralfemoral artery cutdowns with percutaneous contralateralaccess were performed in patients scheduled to undergotube stent-graft placement. Flush aortography was per-formed before and after stent-graft deployment in allcases. Pelvic and additional, selective angiograms wereobtained as needed during the procedure. Angioplasty ofstent-graft elements was performed as required by theprotocol being followed (eg, in the contralateral limb formodular devices) or as needed (with or without additionalbare-metal stents) to resolve attachment endoleaks, kinks,or dissections. Computed tomography (CT), angiography,radiography, ultrasonography, laboratory tests, and physi-cal examinations were performed according to the proto-col being followed. Choice of anesthesia was determinedon the basis of patient risk and hospital practice. Initially,patients received general anesthesia, as was the customfor patients with AAA undergoing open repair proce-dures. More recently, however, epidural anesthesia hasbeen preferred and used whenever possible unless contra-indicated (eg, spine problems, failed epidural anesthesia,or medical conditions requiring intubation for airway con-trol during sedation).
The stent-graft procedure generally involved one sur-gery staff physician, one surgery fellow, and two radiol-ogy staff physicians. The senior members of the team didnot change during the study period. Thus, the same sur-gery and radiology attending physicians were present for
LESTER ET AL Academic Radiology, Vol 8, No 7, July 2001
almost all cases, so the experience level of the team in-creased over time. Vascular surgery and vascular radiol-ogy fellows changed each July; however, they did notperform the critical aspects of these procedures. With oneexception in 1994 (ie, an attending physician with 3 yearsof experience), the attending physicians each had morethan 10 years of clinical experience. In this study, weincluded all actions that were performed during the hospi-tal stay in which the procedure was performed. Preadmis-sion tests or those performed during patient follow-upwere not included in this analysis.
Data SourcesWe obtained data regarding each patient from three
sources: (a) the hospital accounting system (TSI software;Eclipsys, Delray Beach, Fla), (b) a database kept by vas-cular radiologists regarding all endovascular proceduresperformed during the past 6 years, and (c) hospital medi-ca