HE goal of treatment of intracranial aneurysms is to exclude the lesion from the cerebral circulation and to prevent subsequent hemorrhage. Although this can be achieved by microsurgical clipping of the aneu- rysm neck in most cases, the introduction of GDCs has provided an alternative option to treat many lesions. 32–35 This approach was designed to offer a potentially less morbid endovascular approach via transfemoral superse- lective catheterization of an aneurysm, followed by endo- saccular occlusion with microcoils. Such a technique is particularly attractive in circumstances in which open sur- gery is associated with relatively increased risk. The GDC procedure allows early therapeutic intervention, often at the same setting as the initial diagnostic angiographic study, making it particularly appealing in patients with high clinical grades, who may be medically or neurologi- cally unstable. 5,6,12,29,36,59,61,81,82,90,92,105 It avoids brain retrac- tion associated with open surgery, which may be harmful in the swollen brain after acute hemorrhage. It also has been suggested that this method may be safer than mi- crosurgical clipping of selected aneurysms in locations where surgery may be more difficult or risky (such as aneurysms located in the posterior circulation or giant an- eurysms), 19,27,55,79,84 in older patients, and in patients with comorbid medical conditions. 3,6,10,12,24,40,57,60,72,92 With recent advances in microcatheters, aneurysms located at practi- cally any site can be reached and potentially obliterated, particularly aneurysms with narrower neck configurations and smaller sizes, 20 as long as the aneurysm does not in- corporate the parent artery or its branches. There have been several concerns about the GDC pro- J. Neurosurg. / Volume 93 / October, 2000 J Neurosurg 93:569–580, 2000 Impact of Guglielmi detachable coils on outcomes of patients with intracranial aneurysms treated by a multidisciplinary team at a single institution MARY K. STURAITIS, M.D., JAAKKO RINNE, M.D., JOHN C. CHALOUPKA, M.D., MEHMET KAYNAR, M.D., ZHENQIU LIN, PH.D., AND ISSAM A. A WAD, M.D. The Neurovascular Surgery Program, Departments of Anesthesiology, Diagnostic Radiology, and Neurosurgery, Yale University School of Medicine; and the Center for Outcomes Research and Evaluation, Yale–New Haven Hospital, New Haven, Connecticut Object. The goal of this study was to investigate the impact of the introduction of the Guglielmi detachable coil (GDC) therapeutic option on the overall management outcome of intracranial aneurysms. The authors accomplished this by assessing patient morbidity and mortality, inflation-adjusted hospital charges, lengths of stay in the hospital and the intensive care unit (ICU), and treatment efficacy. Methods. The authors conducted a retrospective analysis of consecutive cases of intracranial intradural aneu- rysms managed by a single multidisciplinary neurovascular team at a tertiary care, academic referral center during the 24 months preceding the introduction of the GDC procedure (Group I or pre-GDC era, 77 patients) and during the first 24 months after its introduction (Group II or GDC era, 99 patients). Treatment with GDCs was considered for cases of higher clinical grade or poor surgical risk, or in response to pa- tient preference (27 [27%] of 99 patients in Group II). Host and lesion parameters in our cohort were validated against outcome parameters by using univariate and multivariate analyses. The pre-GDC and GDC subgroups of patients were comparable for major disease severity parameters (patient age, lesion location, clinical grade, and hemorrhage severi- ty). There was no significant difference in clinical outcome at 6 months, infarcts on computerized tomography scan- ning, or aneurysm obliteration rates before and after introduction of GDC treatment. Decreasing trends in duration of hospital and ICU stay and in inflation-adjusted hospital charges occurred well before and thus were unrelated to the introduction of the GDC therapeutic option. Conclusions. The results of this study do not demonstrate any significant impact of integration of the GDC mo- dality on clinical outcome, mortality, morbidity, or effectiveness of treatment. Ongoing improvements in hospital charges and length of hospital stay appeared unrelated to the introduction of the GDC option. KEY WORDS • cerebral aneurysm • Guglielmi detachable coil • outcome • hospital charge T 569 Abbreviations used in this paper: CT = computerized tomogra- phy; GDC = Guglielmi detachable coil; GOS = Glasgow Outcome Scale; ICU = intensive care unit; LOS = length of stay; SAH = sub- arachnoid hemorrhage; US = United States. See the Letter to the Editor and the Response in this issue in Neurosurgical Forum, pp 719–721.