Biomedical subjects

Fred G Barker

Publications and source records attributed to Fred G Barker.

At least 37 records · Page 2Linked to original sources

PubMed2004

Age-dependent differences in short-term outcome after surgical or endovascular treatment of unruptured intracranial aneurysms in the United States, 1996-2000.

INTRODUCTION: Unruptured intracranial aneurysm patients are frequently eligible for both open surgery ("clipping") and endovascular repair ("coiling"). We compared short-term end points (mortality, discharge disposition, complications, length of stay, and charges) for clipping and coiling in a nationally representative discharge database. METHODS: We conducted a retrospective cohort study using Nationwide Inpatient Sample data from 1996 to 2000. Multivariate logistic regression analyses adjusted for age, sex, race, payer status, geographic region, presenting signs and symptoms, admission type and source, procedure timing, hospital caseload, and possible clustering of outcomes within hospitals. The results were confirmed by performing propensity score analysis. RESULTS: A total of 3498 patients had clipping, and 421 underwent coiling. Clipped patients were slightly younger (P < 0.001). Medical comorbidity was similar between the groups. More clipped patients had urgent or emergency admissions (P = 0.02). More coiling procedures were performed on hospital Day 1 (P = 0.007). When only death and discharge to long-term care were counted as adverse outcomes, there was no significant difference between clipping and coiling. On the basis of a four-level discharge status outcome scale (dead, long-term care, short-term rehabilitation, or discharge to home), coiled patients had a significantly better discharge disposition (odds ratio, 2.1; P < 0.001). With regard to patient age, most of the difference in discharge disposition was in patients older than 65 years of age. The degree of difference between treatments increased from 1996 to 2000. Neurological complications were coded twice as frequently in clipped patients as in coiled patients (P = 0.002). Length of stay was longer (5 d versus 2 d, P < 0.001) and charges were higher ($21,800 versus $13,200, P = 0.007) for clipped patients than for coiled patients. CONCLUSION: There was no significant difference in mortality rates or discharge to long-term facilities after clipping or coiling of unruptured aneurysms. When discharge to short-term rehabilitation was counted as an adverse event, coiled patients had significantly better outcomes than clipped patients at the time of hospital discharge, but most of the coiling advantage was concentrated in patients older than 65 years of age. Even in older patients, long-term end points-including long-term functional status in patients discharged to rehabilitation and efficacy in preventing hemorrhage-will be critical in determining the best treatment option for patients with unruptured aneurysms.

Age Factors↗

PubMed2004

Does intracisternal thrombolysis prevent vasospasm after aneurysmal subarachnoid hemorrhage? A meta-analysis.

OBJECTIVE: Despite existing strategies for the treatment of vasospasm after aneurysmal subarachnoid hemorrhage, vasospasm remains a persistent contributor to death and disability. The intracisternal application of thrombolytic agents to dissolve subarachnoid clot has been advocated. The goal of this analysis was to assess the currently available evidence regarding the effectiveness of this treatment. METHODS: We conducted a systematic review of the published literature; all controlled trials were included. The outcomes of interest were delayed ischemic neurological deficits, poor Glasgow Outcome Scale scores, and death. A formal meta-analysis was performed with a random-effects model. RESULTS: The search revealed nine trials or trial subgroups (only one of which was randomized), with a total enrollment of 652 patients. Pooled results demonstrated beneficial effects of treatment, with absolute risk reductions of 14.4% (95% confidence interval, 6.5-22.5%; P < 0.001) for delayed ischemic neurological deficits, 9.5% (95% confidence interval, 4.2-14.8%; P < 0.01) for poor Glasgow Outcome Scale scores, and 4.5% (95% confidence interval, 1.5-7.5%; P < 0.05) for death. Regression analysis revealed that treatment effects did not significantly differ among the studies on the basis of the type of thrombolytic agent used (tissue plasminogen activator versus urokinase) or the method of administration (intraoperative versus postoperative) (P > 0.10). Studies that enrolled only patients at high risk for vasospasm seemed to demonstrate greater treatment effects. CONCLUSION: The meta-analysis suggests a clinically relevant and statistically significant beneficial effect of intracisternal thrombolysis. However, the results of the analysis are limited by the predominance of nonrandomized studies. Further randomized, blinded, placebo-controlled trials of high-risk patients would be justified.

Cisterna Magna↗

PubMed2004

Craniotomy for resection of pediatric brain tumors in the United States, 1988 to 2000: effects of provider caseloads and progressive centralization and specialization of care.

OBJECTIVE: Large provider caseloads are associated with better patient outcomes after many complex surgical procedures. Mortality rates for pediatric brain tumor surgery in various practice settings have not been described. We used a national hospital discharge database to study the volume-outcome relationship for craniotomy performed for pediatric brain tumor resection, as well as trends toward centralization and specialization. METHODS: We conducted a cross sectional and longitudinal cohort study using Nationwide Inpatient Sample data for 1988 to 2000 (Agency for Healthcare Research and Quality, Rockville, MD). Multivariate analyses adjusted for age, sex, geographic region, admission type (emergency, urgent, or elective), tumor location, and malignancy. RESULTS: We analyzed 4712 admissions (329 hospitals, 480 identified surgeons) for pediatric brain tumor craniotomy. The in-hospital mortality rate was 1.6% and decreased from 2.7% (in 1988-1990) to 1.2% (in 1997-2000) during the study period. On a per-patient basis, median annual caseloads were 11 for hospitals (range, 1-59 cases) and 6 for surgeons (range, 1-32 cases). In multivariate analyses, the mortality rate was significantly lower at high-volume hospitals than at low-volume hospitals (odds ratio, 0.52 for 10-fold larger caseload; 95% confidence interval, 0.28-0.94; P = 0.03). The mortality rate was 2.3% at the lowest-volume-quartile hospitals (4 or fewer admissions annually), compared with 1.4% at the highest-volume-quartile hospitals (more than 20 admissions annually). There was a trend toward lower mortality rates after surgery performed by high-volume surgeons (P = 0.16). Adverse hospital discharge disposition was less likely to be associated with high-volume hospitals (P < 0.001) and high-volume surgeons (P = 0.004). Length of stay and hospital charges were minimally related to hospital caseloads. Approximately 5% of United States hospitals performed pediatric brain tumor craniotomy during this period. The burden of care shifted toward large-caseload hospitals, teaching hospitals, and surgeons whose practices included predominantly pediatric patients, indicating progressive centralization and specialization. CONCLUSION: Mortality and adverse discharge disposition rates for pediatric brain tumor craniotomy were lower when the procedure was performed at high-volume hospitals and by high-volume surgeons in the United States, from 1988 to 2000. There were trends toward lower mortality rates, greater centralization of surgery, and more specialization among surgeons during this period.

Adolescent↗

PubMed2004

Changing neurosurgical workload in the United States, 1988-2001: craniotomy other than trauma in adults.

OBJECTIVE: Changes in neurosurgical workload can justify requests for hospital resources and guide planning by neurosurgical training programs. Most previous studies have used non-population-based data sources, such as surveys of professional society members, to explore the neurosurgical workload in the United States. METHODS: This is a retrospective cohort study of patients in Diagnosis Related Group (DRG) 1 ("Craniotomy other than trauma, age > 17") using the Nationwide Inpatient Sample. Statistical methods were adjusted for complex survey methodology to generate total United States caseload estimates. RESULTS: The total United States DRG 1 caseload increased from 70,800 admissions in 1988 to 105,300 admissions in 2001, a 50% relative increase (P < 0.001). For most diagnostic categories, the relative caseload increase was similar to that for the whole group. Patient age and sex distributions remained stable over time. Medical comorbidities, such as hypertension, chronic pulmonary disease, diabetes, and obesity, became more frequent. Elective admissions increased and in-hospital mortality rates decreased. Length of hospital stay decreased during the first half of the study period and then stabilized. Combined with increasing caseload, this caused total annual inpatient DRG 1 days to increase progressively after 1996. The number of United States hospitals with DRG 1 admissions decreased over time. Per-hospital annual DRG 1 caseloads increased, especially at high-volume centers. For the largest 100 hospitals by DRG 1 caseload, total admissions increased from 8.5% of all United States admissions (1988) to 9.4% (2001), whereas DRG 1 caseload increased disproportionately, from 27% to 38% of the United States aggregate caseload. This is evidence that progressive centralization of DRG 1 admissions took place during the study period. CONCLUSION: We documented an increase in total caseload and centralization of care for DRG 1 in the United States during the period 1988 to 2001. Defining the reasons for the changes in neurosurgical workload we observed will require further research.

Adolescent↗

PubMed2004

Superior semicircular canal dehiscence syndrome. Case report.

The authors present the case of a man who had superior semicircular canal dehiscence syndrome in addition to chronic otitis media. This case is atypical because the patient coincidentally had middle ear and mastoid disease, which previously had been treated surgically. The prior ear surgery delayed the diagnosis of superior semicircular canal dehiscence syndrome and increased the complexity of the repair of the superior semicircular canal dehiscence. Superior semicircular canal dehiscence syndrome is a recently recognized syndrome resulting in acute or chronic vestibular symptoms. The diagnosis is made using history, vestibular examination, and computerized tomography studies. Neurosurgeons should be aware that patients with superior semicircular canal dehiscence syndrome who experience disabling chronic or acute vestibular symptoms can be treated using a joint neurosurgical-otological procedure through the middle cranial fossa.

Acute Disease↗

PubMed2004

In-hospital mortality rates after ventriculoperitoneal shunt procedures in the United States, 1998 to 2000: relation to hospital and surgeon volume of care.

OBJECT: Death after ventriculoperitoneal (VP) shunt surgery is uncommon, and therefore it has been difficult to study. The authors used a population-based national hospital discharge database to examine the relationship between annual hospital and surgeon volume of VP shunt surgery in pediatric patients and in-hospital mortality rates. METHODS: All children in the Nationwide Inpatient Sample (1998-2000, age 90 days-18 years) who underwent VP shunt placement or shunt revision as the principal procedure were included. Main outcome measures were in-hospital mortality rates, length of stay (LOS), and total hospital charges. Overall, 5955 admissions were analyzed (253 hospitals, 411 surgeons). Mortality rates were lower at high-volume centers and for high-volume surgeons. In terms of hospital volume, the mortality rate was 0.8% at lowest-quartile-volume centers (< 28 admissions/year) and 0.3% at highest-quartile-volume centers (> 121 admissions/year). In terms of surgeon volume, the mortality rate was 0.8% for lowest-quartile-volume providers (< nine admissions/year) and 0.1% for highest-quartile-volume providers (> 65 admissions/year). After multivariate adjustment for demographic variables, emergency admission and presence of infection, hospital volume of care remained a significant predictor of death (odds ratio [OR] for a 10-fold increase in caseload 0.38; 95% confidence interval [CI] 0.18-0.81). Surgeon volume of care was statistically significant in a similar multivariate model (OR for a 10-fold increase in caseload 0.3; 95% CI 0.13-0.69). Length of stay was slightly shorter and total hospital charges were slightly higher at higher-volume centers, but the differences were not statistically significant. CONCLUSIONS: Pediatric shunt procedures performed at high-volume hospitals or by high-volume surgeons were associated with lower in-hospital mortality rates, with no significant difference in LOS or hospital charges.

Adolescent↗

PubMed2004

Prospective outcomes evaluation after decompression with or without instrumented fusion for lumbar stenosis and degenerative Grade I spondylolisthesis.

OBJECT: There is considerable debate among spine surgeons regarding whether fusion should be used to augment decompressive surgery in patients with symptomatic lumbar spinal stenosis involving Grade I degenerative spondylolisthesis. The authors prospectively evaluated the outcomes of patients treated between 2000 and 2002 at two institutions to determine whether fusion improves functional outcome 1 year after surgery. METHODS: Patients ranged in age from 50 to 81 years. They presented with degenerative Grade I (3- to 14-mm) spondylolisthesis and lumbar stenosis without gross instability (< 3 mm of motion at the level of subluxation). Those in whom previous surgery had been performed at the level of subluxation were excluded. Each patient completed Oswestry Disability Index (ODI) and Short Form-36 (SF-36) questionnaires preoperatively and at 6 to 12 months postoperatively. Some patients underwent decompression alone (20 cases), whereas others underwent decompression and posterolateral instrumentation-assisted fusion (14 cases), at the treating surgeon's discretion. Baseline demographic data, radiographic features, and ODI and SF-36 scores were similar in both groups. The 1-year fusion rate was 93%. Both forms of surgery independently improved outcome compared with baseline status, based on ODI and SF-36 physical component summary (PCS) results (p < 0.001). Decompression combined with fusion led to an improvement in ODI scores of 27.5 points, whereas decompression alone was associated with a 13.6-point increase (p = 0.02). Analysis of the SF-36 PCS data also demonstrated a significant intergroup difference (p = 0.003). CONCLUSIONS: Surgery substantially improved 1-year outcomes based on established outcomes instruments in patients with Grade I spondylolisthesis and stenosis. Fusion was associated with greater functional improvement.

Aged↗

PubMed2003

Surgical excision of acoustic neuroma: patient outcome and provider caseload.

OBJECTIVES/HYPOTHESIS: For many complex surgical procedures, larger hospital or surgeon caseload is associated with better patient outcome. We examined the volume-outcome relationship for surgical excision of acoustic neuromas. STUDY DESIGN: Retrospective cohort study. METHODS: The Nationwide Inpatient Sample (1996 to 2000) was used. Multivariate regression analyses were adjusted for age, sex, race, payer, geographic region, procedure timing, admission type and source, medical comorbidities, and neurofibromatosis status. RESULTS: At 265 hospitals, 2643 operations were performed by 352 identified primary surgeons. Outcome was measured on a four-level scale at hospital discharge: death (0.5%) and discharge to long-term care (1.2%), to short-term rehabilitation (4.4%), and directly to home (94%). Outcomes were significantly better after surgery at higher-volume hospitals (OR 0.47 for fivefold-larger caseload, P <.001) or by higher-volume surgeons (OR 0.46, P <.001). Of patients who had surgery at lowest-volume-quartile hospitals, 12.3% were not discharged directly home, compared with 4.1% at highest-volume-quartile hospitals. There was a trend toward lower mortality for higher-volume hospitals (P =.1) and surgeons (P =.06). Of patients who had surgery at lowest-caseload-quartile hospitals, 1.1% died, compared with 0.6% at highest-volume-quartile hospitals. Postoperative complications (including neurological complications, mechanical ventilation, facial palsy, and transfusion) were less likely with high-volume hospitals and surgeons. Length of stay was significantly shorter with high-volume hospitals (P =.01) and surgeons (P =.009). Hospital charges were lower for high-volume hospitals (by 6% [P =.006]) and surgeons (by 6% [P =.09]). CONCLUSION: For acoustic neuroma excision, higher-volume hospitals and surgeons provided superior short-term outcomes with shorter lengths of stay and lower charges.

Adolescent↗

PubMed2003

Transsphenoidal surgery for pituitary tumors in the United States, 1996-2000: mortality, morbidity, and the effects of hospital and surgeon volume.

Larger surgical caseload is associated with better patient outcome for many complex procedures. We examined the volume-outcome relationship for transsphenoidal pituitary tumor surgery using the Nationwide Inpatient Sample, 1996-2000. Multivariate regression adjusted for patient demographics, acuity measures, medical comorbidities, and endocrine status. A total of 5497 operations were performed at 538 hospitals by 825 surgeons. Outcome measured at hospital discharge was: death (0.6%), discharge to long-term care (0.9%), to short-term rehabilitation (2.1%), or directly home (96.2%). Outcomes were better after surgery at higher-volume hospitals (OR 0.74 for 5-fold-larger caseload, P = 0.007) or by higher-volume surgeons (OR 0.62, P = 0.02). A total of 5.4% of patients were not discharged directly home from lowest-volume-quartile hospitals, compared with 2.6% at highest-volume-quartile hospitals. In-hospital mortality was lower with higher-volume hospitals (P = 0.03) and surgeons (P = 0.09). Mortality rates were 0.9% at lowest-caseload-quartile hospitals and 0.4% at highest-volume-quartile hospitals. Postoperative complications (26.5% of admissions) were less frequent with higher-volume hospitals (P = 0.03) or surgeons (P = 0.005). Length of stay was shorter with high-volume hospitals (P = 0.02) and surgeons (P < 0.001). Hospital charges were lower for high-volume hospitals, but not significantly. This analysis suggests that higher-volume hospitals and surgeons provide superior short-term outcomes after transsphenoidal pituitary tumor surgery with shorter lengths of stay and a trend toward lower charges.

Adolescent↗

PubMed2003

Microvascular decompression surgery in the United States, 1996 to 2000: mortality rates, morbidity rates, and the effects of hospital and surgeon volumes.

OBJECTIVE: Microvascular decompression (MVD) is associated with low mortality and morbidity rates at specialized centers, but many MVD procedures are performed outside such centers. We studied short-term end points after MVD in a national hospital discharge database sample. METHODS: A retrospective cohort study was performed by using the Nationwide Inpatient Sample, 1996 to 2000. RESULTS: The sample included 1326 MVD procedures for treatment of trigeminal neuralgia, 237 for treatment of hemifacial spasm, and 27 for treatment of glossopharyngeal neuralgia, performed at 305 hospitals by 277 identified surgeons. The mortality rate was 0.3%, and the rate of discharge other than to home was 3.8%. Neurological complications were coded in 1.7% of cases, hematomas in 0.5%, and facial palsies in 0.6%, with 0.4% of patients requiring ventriculostomies and 0.7% postoperative ventilation. Trigeminal nerve section was also coded for 3.4% of patients with trigeminal neuralgia, more commonly among older patients (P = 0.08), among female patients (P = 0.03), and at teaching hospitals (P = 0.02). The median annual caseloads were 5 cases per hospital (range, 1-195 cases) and 3 cases per surgeon (range, 1-107 cases). With adjustment for age, sex, race, primary insurance, diagnosis (trigeminal neuralgia versus hemifacial spasm versus glossopharyngeal neuralgia), geographic region, admission type and source, and medical comorbidities, outcomes at discharge were superior at higher-volume hospitals (P = 0.006) and with higher-volume surgeons (P = 0.02). Complications were less frequent after surgery performed at high-volume hospitals (P = 0.04) or by high-volume surgeons (P = 0.01). The rate of discharge other than to home was 5.1% for the lowest-volume-quartile hospitals, compared with 1.6% for the highest-volume-quartile hospitals. Volume and mortality rate were not significantly related, but three of the four deaths in the series followed procedures performed by surgeons who had performed only one MVD procedure that year. Length of stay (median, 3 d) and hospital volume were not significantly related. Hospital charges were slightly higher at higher-volume hospitals (P = 0.007). CONCLUSION: Although most MVD procedures in the United States are performed at low-volume centers, mortality rates remain low. Morbidity rates are significantly lower at high-volume hospitals and with high-volume surgeons.

Adolescent↗

PubMed2003

Proton beam radiosurgery for vestibular schwannoma: tumor control and cranial nerve toxicity.

OBJECTIVE: We sought to determine the tumor control rate and cranial nerve function outcomes in patients with vestibular schwannomas who were treated with proton beam stereotactic radiosurgery. METHODS: Between November 1992 and August 2000, 88 patients with vestibular schwannomas were treated at the Harvard Cyclotron Laboratory with proton beam stereotactic radiosurgery in which two to four convergent fixed beams of 160-MeV protons were applied. The median transverse diameter was 16 mm (range, 2.5-35 mm), and the median tumor volume was 1.4 cm(3) (range, 0.1-15.9 cm(3)). Surgical resection had been performed previously in 15 patients (17%). Facial nerve function (House-Brackmann Grade 1) and trigeminal nerve function were normal in 79 patients (89.8%). Eight patients (9%) had good or excellent hearing (Gardner-Robertson [GR] Grade 1), and 13 patients (15%) had serviceable hearing (GR Grade 2). A median dose of 12 cobalt Gray equivalents (range, 10-18 cobalt Gray equivalents) was prescribed to the 70 to 108% isodose lines (median, 70%). The median follow-up period was 38.7 months (range, 12-102.6 mo). RESULTS: The actuarial 2- and 5-year tumor control rates were 95.3% (95% confidence interval [CI], 90.9-99.9%) and 93.6% (95% CI, 88.3-99.3%). Salvage radiosurgery was performed in one patient 32.5 months after treatment, and a craniotomy was required 19.1 months after treatment in another patient with hemorrhage in the vicinity of a stable tumor. Three patients (3.4%) underwent shunting for hydrocephalus, and a subsequent partial resection was performed in one of these patients. The actuarial 5-year cumulative radiological reduction rate was 94.7% (95% CI, 81.2-98.3%). Of the 21 patients (24%) with functional hearing (GR Grade 1 or 2), 7 (33.3%) retained serviceable hearing ability (GR Grade 2). Actuarial 5-year normal facial and trigeminal nerve function preservation rates were 91.1% (95% CI, 85-97.6%) and 89.4% (95% CI, 82-96.7%). Univariate analysis revealed that prescribed dose (P = 0.005), maximum dose (P = 0.006), and the inhomogeneity coefficient (P = 0.03) were associated with a significant risk of long-term facial neuropathy. No other cranial nerve deficits or cancer relapses were observed. CONCLUSION: Proton beam stereotactic radiosurgery has been shown to be an effective means of tumor control. A high radiological response rate was observed. Excellent facial and trigeminal nerve function preservation rates were achieved. A reduced prescribed dose is associated with a significant decrease in facial neuropathy.

Adult↗

PubMed2003

Perioperative complications and neurological outcomes of first and second craniotomies among patients enrolled in the Glioma Outcome Project.

OBJECT: In many new clinical trials of patients with malignant gliomas surgical intervention is incorporated as an integral part of tumor-directed interstitial therapies such as gene therapy, biodegradable wafer placement, and immunotherapy. Assessment of toxicity is a major component of evaluating these novel therapeutic interventions, but this must be done in light of known complication rates of craniotomy for tumor resection. Factors predicting neurological outcome would also be helpful for patient selection for surgically based clinical trials. METHODS: The Glioma Outcome Project is a prospectively compiled database containing information on 788 patients with malignant gliomas that captured clinical practice patterns and patient outcomes. Patients in this series who underwent their first or second craniotomy were analyzed separately for presenting symptoms, tumor and patient characteristics, and perioperative complications. Preoperative and intraoperative factors possibly related to neurological outcome were evaluated. There were 408 patients who underwent first craniotomies (C1 group) and 91 patients who underwent second ones (C2 group). Both groups had similar patient and tumor characteristics except for their median age (55 years in the C1 group compared with 50 years in the C2 group; p = 0.006). Headache was more common at presentation in the C1 group, whereas papilledema and an altered level of consciousness were more common at presentation in patients undergoing second surgeries. Perioperative complications occurred in 24% of patients in the C1 group and 33% of patients in the C2 group (p = 0.1). Most patients were the same or better neurologically after surgery, but more patients in the C2 group (18%) displayed a worsened neurological status than those in the C1 group (8%; p = 0.007). The Karnofsky Performance Scale score and, in patients in the C2 group, tumor size were important neurological outcome predictors. Regional complications occurred at similar rates in both groups. Systemic infections occurred more frequently in the C2 group (4.4 compared with 0%; p < 0.0001) as did depression (20 compared with 11%; p = 0.02). The perioperative mortality rate was 1.5% for the C1 group and 2.2% for the C2 group (p = not significant). The median length of the hospital stay was 4 days in each group. CONCLUSIONS: Perioperative complications occur slightly more often following a second craniotomy for malignant glioma than after the first craniotomy. This should be considered when evaluating toxicities from intraoperative local therapies requiring craniotomy. Nevertheless, most patients are neurologically stable or improved after either their first or second craniotomy. This data set may serve as a benchmark for neurosurgeons and others in a discussion of operative risks in patients with malignant gliomas.

Central Nervous System Neoplasms↗

PubMed2003

Dose-volume prediction of radiation-related complications after proton beam radiosurgery for cerebral arteriovenous malformations.

OBJECT: The use of radiosurgery for the treatment of cerebral arteriovenous malformations (AVMs) and other lesions demands an accurate understanding of the risk of radiation-related complications. Some commonly used formulas for predicting risk are based on extrapolation from small numbers of animal experiments, pilot human treatment series, and theoretical radiobiological considerations. The authors studied the incidence of complications after AVM radiosurgery in relation to dose, volume, and other factors in a large patient series. METHODS: A retrospective review was conducted in 1329 patients with AVM treated by Dr. Raymond Kjellberg at the Harvard Cyclotron Laboratory (HCL) between 1965 and 1993. Dose and volume were obtained from HCL records, and information about patient follow up was derived from concurrent clinical records, questionnaires, and contact with referring physicians. Multivariate logistic regression with bootstrapped confidence intervals was used. Follow up was available in 1250 patients (94%); the median follow-up duration was 6.5 years. The median radiation dose was 10.5 Gy and the median treatment volume was 33.7 cm(3). Twenty-three percent of treated lesions were smaller than 10 cm(3). Fifty-one permanent radiation-related deficits occurred (4.1%). Of 1043 patients treated with a dose predicted by the Kjellberg isoeffective centile curve to have a less than 1% complication risk, 1.8% suffered radiation-related complications. Actual complication rates were 4.7% for 128 patients treated at Kjellberg risk centile doses of 1 to 1.8%, and 34% for 61 patients treated at risk centile doses of 2 to 2.5%. The fitted logistic model showed that complication risk was related to treatment dose and volume, thalamic or brainstem location, and patient age. CONCLUSIONS: The Kjellberg isoeffective risk centile curve significantly underpredicted actual risks of permanent complications after proton beam radiosurgery for AVMs. Actual risks were best predicted using a model that accounted for treatment dose and volume, lesion location, and patient age.

Adolescent↗

PubMed2003

Surgery for Parkinson disease in the United States, 1996 to 2000: practice patterns, short-term outcomes, and hospital charges in a nationwide sample.

OBJECT: The surgical treatment of Parkinson disease (PD) has undergone a dramatic shift, from stereotactic ablative procedures toward deep brain stimulaion (DBS). The authors studied this process by investigating practice patterns, mortality and morbidity rates, and hospital charges as reflected in the records of a representative sample of US hospitals between 1996 and 2000. METHODS: The authors conducted a retrospective cohort study by using the Nationwide Inpatient Sample database; 1761 operations at 71 hospitals were studied. Projected to the US population, there were 1650 inpatient procedures performed for PD per year (pallidotomies, thalamotomies, and DBS), with no significant change in the annual number of procedures during the study period. The in-hospital mortality rate was 0.2%, discharge other than to home was 8.1%, and the rate of neurological complications was 1.8%, with no significant differences between procedures. In multivariate analyses, hospitals with larger annual caseloads had lower mortality rates (p = 0.002) and better outcomes at hospital discharge (p = 0.007). Placement of deep brain stimulators comprised 0% of operations in 1996 and 88% in 2000. Factors predicting placement of these devices in analyses adjusted for year of surgery included younger age, Caucasian race, private insurance, residence in higher-income areas, hospital teaching status, and smaller annual hospital caseload. In multivariate analysis, total hospital charges were 2.2 times higher for DBS (median dollar 36,000 compared with dollar 12,000, p < 0.001), whereas charges were lower at higher-volume hospitals (p < 0.001). CONCLUSIONS: Surgical treatment of PD in the US changed significantly between 1996 and 2000. Larger-volume hospitals had superior short-term outcomes and lower charges. Future studies should address long-term functional end points, cost/benefit comparisons, and inequities in access to care.

Adult↗

PubMed2003

In-hospital mortality and morbidity after surgical treatment of unruptured intracranial aneurysms in the United States, 1996-2000: the effect of hospital and surgeon volume.

OBJECTIVE: We sought to determine the risk of adverse outcome after contemporary surgical treatment of patients with unruptured intracranial aneurysms in the United States. Patient, surgeon, and hospital characteristics were tested as potential outcome predictors, with particular attention to the surgeon's and hospital's volume of care. METHODS: We performed a retrospective cohort study with the Nationwide Inpatient Sample, 1996 to 2000. Multivariate logistic and ordinal regression analyses were performed with endpoints of mortality, discharge other than to home, length of stay, and total hospital charges. RESULTS: We identified 3498 patients who were treated at 463 hospitals, and we identified 585 surgeons in the database. Of all patients, 2.1% died, 3.3% were discharged to skilled-nursing facilities, and 12.8% were discharged to other facilities. The analysis adjusted for age, sex, race, primary payer, four variables measuring acuity of treatment and medical comorbidity, and five variables indicating symptoms and signs. The statistics for median annual number of unruptured aneurysms treated were eight per hospital and three per surgeon. High-volume hospitals had fewer adverse outcomes than hospitals that handled comparatively fewer unruptured aneurysms: discharge other than to home occurred after 15.6% of operations at high-volume hospitals (20 or more cases/yr) compared with 23.8% at low-volume hospitals (fewer than 4 cases/yr) (P = 0.002). High surgeon volume had a similar effect (15.3 versus 20.6%, P = 0.004). Mortality was lower at high-volume hospitals (1.6 versus 2.2%) than at hospitals that handled comparatively fewer unruptured aneurysms, but not significantly so. Patients treated by high-volume surgeons had fewer postoperative neurological complications (P = 0.04). Length of stay was not related to hospital volume. Charges were slightly higher at high-volume hospitals, partly because arteriography was performed more frequently than at hospitals that handled comparatively fewer unruptured aneurysms. CONCLUSION: For patients with unruptured aneurysms who were treated in the United States between 1996 and 2000, surgery performed at high-volume institutions or by high-volume surgeons was associated with significantly lower morbidity and modestly lower mortality.

Adolescent↗

PubMed2003

In-hospital morbidity and mortality after endovascular treatment of unruptured intracranial aneurysms in the United States, 1996-2000: effect of hospital and physician volume.

BACKGROUND AND PURPOSE: Endovascular therapy is increasingly being used for the treatment of unruptured intracranial aneurysms. Our purpose was to determine the risk of adverse outcomes after contemporary endovascular treatment of unruptured intracranial aneurysms in the United States. Patient, treating physician, and hospital characteristics were tested as potential outcome predictors, with particular attention paid to volume of care. METHODS: We conducted a retrospective cohort study by using the Nationwide Inpatient Sample, 1996-2000. Multivariate logistic and ordinal regressions were used with end points of mortality, discharge other than to home, length of stay, and total hospital charges. RESULTS: Four hundred twenty-one patients underwent endovascular treatment at 81 hospitals. The in-hospital mortality rate was 1.7%, and 7.6% were discharged to institutions other than home. Analysis was adjusted for age, sex, race, primary payer, year of treatment, and four variables measuring acuity of treatment and medical comorbidity. Median annual number of unruptured aneurysms treated was nine per hospital and three per treating physician. Higher volume hospitals had fewer adverse outcomes; discharge other than to home occurred after 5.2% of operations at high volume hospitals (>23 admissions per year) compared with 17.6% at low volume hospitals (fewer than four admissions per year) (P<.001). Higher physician volume had a similar effect (0% versus 16.4%, P=.03). The mortality rate was lower at high volume hospitals (1.0% versus 3.7%) but not significantly so. At high volume hospitals, length of stay was shorter (P<.001) and total hospital charges were lower (P<.001). CONCLUSION: For patients with unruptured aneurysms treated in the United States from 1996 to 2000, endovascular treatment at high volume institutions or by high volume physicians was associated with significantly lower morbidity rates and modestly lower mortality rates. Length of stay was shorter and total hospital charges lower at high volume centers.

Adolescent↗

PubMed2002

Clinical trial participation among patients enrolled in the Glioma Outcomes Project.

BACKGROUND: Patient participation in well-designed and conducted clinical trials enables researchers to test new therapies. An understanding of the variables that possibly influence patient enrollment may help in patient recruitment for future trials. The authors evaluated factors that influenced patient enrollment in clinical trials using a prospective, large, multi-institutional registry of patients with malignant glioma. METHODS: Data were examined from 708 patients who underwent first or second surgery for a malignant glioma who were enrolled in the Glioma Outcomes Project, which is a prospective observational data base that captures clinical practice patterns. The frequency of clinical trial participation and the variables that may have been associated with trial participation were evaluated. These variables included age, gender, race, household income, educational level, first versus second craniotomy, histology, and whether the patient was treated at an academic institution. RESULTS: One hundred fifty-one of 708 patients (21.3%) participated in a clinical trial, which was higher than the participation reported typically for patients with other types of primary malignancies. In univariate analysis, race, histology, and first craniotomy were significant between the two groups, with Caucasian patients and patients with glioblastoma histology showing higher participation rates. In a multivariate logistic regression model, significant predictors included young age and glioblastoma multiforme histology. CONCLUSIONS: The authors present information on factors that may influence clinical trial participation among patients with malignant glioma and compare their data with information described previously on patients with other types of malignant disease. The percent of participation among the patients in the current study was greater than among patients with other primary tumor sites. Strategies should be implemented to improve recruitment to neuro-oncology trials, especially in elderly and minority populations.

Age Factors↗

PubMed2002

Efficacy of prophylactic antibiotic therapy in spinal surgery: a meta-analysis.

OBJECTIVE: There is considerable variation in practice regarding the use of prophylactic antibiotic therapy in spinal operations. To date, individual studies have not demonstrated a significant benefit for prophylactic antibiotic therapy in spinal operations. METHODS: Systematic database searches for randomized prospective trials of prophylactic antibiotic therapy in spinal surgery, general neurosurgery, and orthopedic surgery were performed. Random-effects meta-analysis and Bayesian meta-regressions of treatment benefits versus baseline infection rates and other trial characteristics were performed. RESULTS: Six prospective randomized trials or trial subgroups, enrolling 843 patients, were identified, i.e., one spinal surgery trial, four general neurosurgery trials, and one general orthopedic surgery trial. No individual trial demonstrated a statistically significant effect of prophylactic antibiotic therapy for spinal surgery patients. Raw pooled infection rates were 2.2% (10 of 451 patients) with antibiotics and 5.9% (23 of 392 patients) without antibiotics. Individual trial infection rates ranged from 1.2 to 8.5%. The pooled odds ratio was 0.37 (95% confidence interval, 0.17-0.78), favoring antibiotic treatment (P < 0.01). There was no significant heterogeneity in treatment efficacy among the trials. Bayesian meta-regression was used to test whether antibiotics were less effective in trials with low baseline infection rates and whether an optimal antibiotic regimen could be identified. There was no significant difference in antibiotic treatment effects in trials with lower baseline infection rates, in trials using antibiotics with gram-negative coverage in addition to gram-positive coverage, or in trials using multiple-dose versus single-dose regimens. Nonrandomized studies of antibiotic therapy in spinal surgery yielded greater treatment effect estimates than did randomized trials, but not significantly so. CONCLUSION: Prophylactic antibiotic therapy is beneficial for spinal surgery, even when expected infection rates without antibiotic treatment are low.

Antibiotic Prophylaxis↗