Geographic variation and regional trends in adoption of endovascular techniques for cerebral aneurysms

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Considerable evolution has occurred in treatment options for cerebral aneurysms. Development of endovascular techniques has produced a significant change in the treatment of ruptured and unruptured intracranial aneurysms. Adoption of endovascular techniques and increasing numbers of patients undergoing endovascular treatment may affect health care expenditures. Geographic assessment of growth in endovascular procedures has not been assessed.


The National Inpatient Sample (NIS) was queried for ICD-9 codes for clipping and coiling of ruptured and unruptured cerebral aneurysms from 2002 to 2008. Patients with ruptured and unruptured cerebral aneurysms were compared according to in-hospital deaths, hospital length of stay, total hospital cost, and selected procedure. Hospital costs were adjusted to bring all costs to 2008 equivalents. Regional variation over the course of the study was explored.


The NIS recorded 12,588 ruptured cerebral aneurysm cases (7318 clipped and 5270 coiled aneurysms) compared with 11,606 unruptured aneurysm cases (5216 clipped and 6390 coiled aneurysms), representing approximately 121,000 aneurysms treated in the study period. Linear regression analysis found that the number of patients treated endovascularly increased over time, with the total number of endovascular patients increasing from 17.28% to 57.59% for ruptured aneurysms and from 29.70% to 62.73% for unruptured aneurysms (p < 0.00001). Patient age, elective status, and comorbidities increased the likelihood of endovascular treatment (p < 0.00001, p < 0.00004, and p < 0.02, respectively). In patients presenting with subarachnoid hemorrhage (SAH), endovascular treatments were more commonly chosen in urban and academic medical centers (p = 0.009 and p = 0.05, respectively). In-hospital deaths decreased over the study period in patients with both ruptured and unruptured aneurysms (p < 0.00001); presentation with SAH remained the single greatest predictor of death (OR 38.09, p < 0.00001). Geographic analysis showed growth in endovascular techniques concentrated in eastern and western coastal states, with substantial variation in adoption of endovascular techniques (range of percentage of endovascular patients [2008] 0%–92%). There were higher costs in patients treated endovascularly, but these differences were likely secondary to presenting diagnosis and site-of-service variations.


The NIS database reveals a significant increase in the use of endovascular techniques, with the majority of both ruptured and unruptured aneurysms treated endovascularly by 2008. Differences in hospital costs between open and endovascular techniques are likely secondary to patient and site-of-service factors. Presentation with SAH was the primary factor affecting hospital cost and a greater percentage of endovascular procedures completed at urban academic medical centers. There is substantial regional variation in the adoption of endovascular techniques.

Abbreviations used in this paper: AHRQ = Agency for Health Care Research and Quality; CHF = congestive heart failure; ISAT = International Subarachnoid Aneurysm Trial; LOS = length of stay; NIS = National Inpatient Sample; SAH = subarachnoid hemorrhage.

Article Information

Address correspondence to: John K. Ratliff, M.D., Department of Neurosurgery, Thomas Jefferson University, 909 Walnut Street, 2nd Floor, Philadelphia, Pennsylvania 19107. email:

Please include this information when citing this paper: published online February 11, 2011; DOI: 10.3171/2011.1.JNS101528.

© AANS, except where prohibited by US copyright law.



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    Line graph showing the increase in endovascular therapies in both ruptured and unruptured cerebral aneurysms from 2002 to 2008, based on assessment of the AHRQ NIS database.

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    Line graph showing the relationship between advancing patient age (in years) and choice of endovascular therapy in ruptured and unruptured cerebral aneurysms from 2002 to 2008, based on assessment of the AHRQ NIS database.

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    Maps illustrating the geographic disparity in adoption of endovascular techniques. Color-coding illustrates the percentage of aneurysms (ruptured and unruptured) treated endovascularly. There was a substantial increase in endovascular therapy between 2002 and 2008, with specific increases concentrated along the eastern portion of the US and along the Pacific Coast.

  • View in gallery

    Line graph demonstrating the relationship between hospital charges, patient presenting diagnosis (ruptured vs unruptured cerebral aneurysm), and choice of treatment (endovascular vs open surgery). Endovascular and open treatments had very similar hospital charges, with the primary disparity arising from differences in patient presentation.


  • 1

    Andaluz NZuccarello M: Recent trends in the treatment of cerebral aneurysms: analysis of a nationwide inpatient database. J Neurosurg 108:116311692008

  • 2

    Baicker KFisher ESChandra A: Malpractice liability costs and the practice of medicine in the Medicare program. Health Aff (Millwood) 26:8418522007

  • 3

    Bairstow PDodgson ALinto JKhangure M: Comparison of cost and outcome of endovascular and neurosurgical procedures in the treatment of ruptured intracranial aneurysms. Australas Radiol 46:2492512002

  • 4

    Barker FG IIAmin-Hanjani SButler WEHoh BLRabinov JDPryor JC: Age-dependent differences in short-term outcome after surgical or endovascular treatment of unruptured intracranial aneurysms in the United States, 1996–2000. Neurosurgery 54:18302004

  • 5

    Brilstra EHRinkel GJvan der Graaf YSluzewski MGroen RJLo RT: Quality of life after treatment of unruptured intracranial aneurysms by neurosurgical clipping or by embolisation with coils. A prospective, observational study. Cerebrovasc Dis 17:44522004

  • 6

    Britz GWSalem LNewell DWEskridge JFlum DR: Impact of surgical clipping on survival in unruptured and ruptured cerebral aneurysms: a population-based study. Stroke 35:139914032004

  • 7

    Fisher ESBynum JPSkinner JS: Slowing the growth of health care costs—lessons from regional variation. N Engl J Med 360:8498522009

  • 8

    Fisher ESWennberg DEStukel TAGottlieb DJ: Variations in the longitudinal efficiency of academic medical centers. Health Aff (Millwood) SupplVAR19VAR322004. ( [Accessed January 7 2011]

  • 9

    Fisher ESWennberg DEStukel TAGottlieb DJLucas FLPinder EL: The implications of regional variations in Medicare spending. Part 2: health outcomes and satisfaction with care. Ann Intern Med 138:2882982003

  • 10

    Flett LMChandler CSGiddings DGholkar A: Aneurysmal subarachnoid hemorrhage: management strategies and clinical outcomes in a regional neuroscience center. AJNR Am J Neuroradiol 26:3673722005

  • 11

    Halkes PHWermer MJRinkel GJBuskens E: Direct costs of surgical clipping and endovascular coiling of unruptured intracranial aneurysms. Cerebrovasc Dis 22:40452006

  • 12

    Higashida RTLahue BJTorbey MTHopkins LNLeip EHanley DF: Treatment of unruptured intracranial aneurysms: a nationwide assessment of effectiveness. AJNR Am J Neuroradiol 28:1461512007

  • 13

    Hoh BLChi YYDermott MALipori PJLewis SB: The effect of coiling versus clipping of ruptured and unruptured cerebral aneurysms on length of stay, hospital cost, hospital reimbursement, and surgeon reimbursement at the university of Florida. Neurosurgery 64:6146212009

  • 14

    Hoh BLChi YYLawson MFMocco JBarker FG II: Length of stay and total hospital charges of clipping versus coiling for ruptured and unruptured adult cerebral aneurysms in the Nationwide Inpatient Sample database 2002 to 2006. Stroke 41:3373422010

  • 15

    Hoh BLRabinov JDPryor JCCarter BSBarker FG II: Inhospital morbidity and mortality after endovascular treatment of unruptured intracranial aneurysms in the United States, 1996–2000: effect of hospital and physician volume. AJNR Am J Neuroradiol 24:140914202003

  • 16

    Javadpour MJain HWallace MCWillinsky RAter Brugge KGTymianski M: Analysis of cost related to clinical and angiographic outcomes of aneurysm patients enrolled in the international subarachnoid aneurysm trial in a North American setting. Neurosurgery 56:8868942005

  • 17

    Johnston SC: Effect of endovascular services and hospital volume on cerebral aneurysm treatment outcomes. Stroke 31:1111172000

  • 18

    Johnston SCDudley RAGress DROno L: Surgical and endovascular treatment of unruptured cerebral aneurysms at university hospitals. Neurology 52:179918051999

  • 19

    Johnston SCHigashida RTBarrow DLCaplan LRDion JEHademenos G: Recommendations for the endovascular treatment of intracranial aneurysms: a statement for healthcare professionals from the Committee on Cerebrovascular Imaging of the American Heart Association Council on Cardiovascular Radiology. Stroke 33:253625442002

  • 20

    Johnston SCWilson CBHalbach VVHigashida RTDowd CFMcDermott MW: Endovascular and surgical treatment of unruptured cerebral aneurysms: comparison of risks. Ann Neurol 48:11192000

  • 21

    Johnston SCZhao SDudley RABerman MFGress DR: Treatment of unruptured cerebral aneurysms in California. Stroke 32:5976052001

  • 22

    Maud ALakshminarayan KSuri MFVazquez GLanzino GQureshi AI: Cost-effectiveness analysis of endovascular versus neurosurgical treatment for ruptured intracranial aneurysms in the United States. Clinical article. J Neurosurg 110:8808862009

  • 23

    Molyneux AJKerr RSYu LMClarke MSneade MYarnold JA: International subarachnoid aneurysm trial (ISAT) of neurosurgical clipping versus endovascular coiling in 2143 patients with ruptured intracranial aneurysms: a randomised comparison of effects on survival, dependency, seizures, rebleeding, subgroups, and aneurysm occlusion. Lancet 366:8098172005

  • 24

    Mullan SBeckman FVailati GKarasick JDobben G: An experimental approach to the problem of cerebral aneurysms. J Neurosurg 21:8388451964

  • 25

    Niskanen MKoivisto TRonkainen ARinne JRuokonen E: Resource use after subarachnoid hemorrhage: comparison between endovascular and surgical treatment. Neurosurgery 54:108110882004

  • 26

    Serbinenko FA: Balloon catheterization and occlusion of major cerebral vessels. J Neurosurg 41:1251451974

  • 27

    Sirovich BGallagher PMWennberg DEFisher ES: Discretionary decision making by primary care physicians and the cost of U.S. Health care. Health Aff (Millwood) 3:8138232008

  • 28

    Wolstenholme JRivero-Arias OGray AMolyneux AJKerr RSYarnold JA: Treatment pathways, resource use, and costs of endovascular coiling versus surgical clipping after aSAH. Stroke 39:1111192008




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