Extent of resection and survival for oligodendroglioma: a U.S. population-based study.

BACKGROUND: National guidelines recommend maximal safe resection of low-grade and high-grade oligodendrogliomas. However, there is no level 1 evidence to support these guidelines, and recent retrospective studies on the topic have yielded mixed results. OBJECTIVE: To assess the association between extent of resection (EOR) and survival for oligodendrogliomas in the general U.S. METHODS: Cases diagnosed between 2004 and 2013 were selected from the Surveillance, Epidemiology, and End-Results (SEER) Program and retrospectively analyzed for treatment, prognostic factors, and survival times. Cases that did not undergo tumor de-bulking surgery (e.g. no surgery or biopsy alone) were compared to subtotal resection (resection) and gross-total resection (GTR). The primary end-points were overall survival (OS) and cause-specific survival (CSS). An external validation cohort with 1p/19q-codeleted tumors was creating using the TCGA and GSE16011 datasets. RESULTS: 3135 Cases were included in the final analysis. The 75% survival time (75ST) and 5-year survival rates were 47 months and 70.8%, respectively. Subtotal resection (STR, 75ST = 50 months) and GTR (75ST = 61 months) were associated with improved survival times compared to cases that did not undergo surgical debulking (75ST = 20 months, P < 0.001 for both), with reduced hazard ratios (HRs) after controlling for other factors (HR 0.81 [0.68-0.97] and HR 0.65 [0.54-0.79], respectively). GTR was associated with improved OS in both low-grade and anaplastic oligodendroglioma subgroups (HR 0.74 [0.58-0.95], HR 0.60 [0.44-0.82], respectively) while STR fell short of significance in the subgroup analysis. All findings were corroborated by multivariable analysis of CSS and externally validated in a cohort of patients with 1p19q-codeleted tumors. CONCLUSION: Greater EOR is associated with improved survival in oligodendrogliomas. Our findings in this U.S. population-based cohort support national guidelines.

Management patterns of patients with cerebral metastases who underwent multiple stereotactic radiosurgeries.

With escalating focus on cost containment, there is increasing scrutiny on the practice of multiple stereotactic radiosurgeries (SRSs) for patients with cerebral metastases distant to the initial tumor site. Our goal was to determine the survival patterns of patients with cerebral metastasis who underwent multiple SRSs. We retrospectively analyzed survival outcomes of 801 patients with 3683 cerebral metastases from primary breast, colorectal, lung, melanoma and renal histologies consecutively treated at the University of California, San Diego/San Diego Gamma Knife Center (UCSD/SDGKC), comparing the survival pattern of patients who underwent a single (n = 643) versus multiple SRS(s) (n = 158) for subsequent cerebral metastases. Findings were recapitulated in an independent cohort of 2472 patients, with 26,629 brain metastases treated with SRS at the Katsuta Hospital Mito GammaHouse (KHMGH). For the UCSD/SDGKC cohort, no significant difference in median survival was found for patients undergoing 1, 2, 3, or ≥4 SRS(s) (median survival of 167, 202, 129, and 127 days, respectively). Median intervals between treatments consistently ranged 140-178 days irrespective of the number of SRS(s) (interquartile range 60-300; p = 0.25). Patients who underwent >1 SRSs tend to be younger, with systemic disease control, harbor lower cumulative tumor volume but increased number of metastases, and have primary melanoma (p < 0.001, <0.001, <0.001, 0.02, and 0.009, respectively). Comparable results were found in the KHMGH cohort. Using an independent validation study design, we demonstrated comparable overall survival between judiciously selected patients who underwent a single or multiple SRS(s).

Impact of neurosurgeon specialization on patient outcomes for intracranial and spinal surgery: a retrospective analysis of the Nationwide Inpatient Sample 1998-2009.

OBJECTIVE The subspecialization of neurosurgical practice is an ongoing trend in modern neurosurgery. However, it remains unclear whether the degree of surgeon specialization is associated with improved patient outcomes. The authors hypothesized that a trend toward increased neurosurgeon specialization was associated with improved patient morbidity and mortality rates. METHODS The Nationwide Inpatient Sample (NIS) was used (1998-2009). Patients were included in a spinal analysis cohort for instrumented spine surgery involving the cervical spine ( International Classification of Diseases, Ninth Revision, Clinical Modification [ICD-9-CM] codes 81.31-81.33, 81.01-81.03, 84.61-84.62, and 84.66) or lumbar spine (codes 81.04-81.08, 81.34-81.38, 84.64-84.65, and 84.68). A cranial analysis cohort consisted of patients receiving a parenchymal excision or lobectomy operation (codes 01.53 and 01.59). Surgeon specialization was measured using unique surgeon identifiers in the NIS and defined as the proportion of a surgeon's total practice dedicated to cranial or spinal cases. RESULTS A total of 46,029 and 231,875 patients were identified in the cranial and spinal analysis cohorts, respectively. On multivariate analysis in the cranial analysis cohort (after controlling for overall surgeon volume, patient demographic data/comorbidities, hospital characteristics, and admitting source), each percentage-point increase in a surgeon's cranial specialization (that is, the proportion of cranial cases) was associated with a 0.0060 reduction in the log odds of patient mortality (95% CI 0.0034-0.0086) and a 0.0042 reduction in the log odds of morbidity (95% CI 0.0032-0.0052). This resulted in a 15% difference in the predicted probability of mortality for neurosurgeons at the 75th versus the 25th percentile of cranial specialization. In the spinal analysis cohort, each percentage-point increase in a surgeon's spinal specialization was associated with a 0.0122 reduction in the log odds of mortality (95% CI 0.0074-0.0170) and a 0.0058 reduction in the log odds of morbidity (95% CI 0.0049-0.0067). This resulted in a 26.8% difference in the predicted probability of mortality for neurosurgeons at the 75th versus the 25th percentile of spinal specialization. CONCLUSIONS For both spinal and cranial surgery patient cohorts derived from the NIS database, increased surgeon specialization was significantly and independently associated with improved mortality and morbidity rates, even after controlling for overall case volume.

Cumulative Intracranial Tumor Volume (CITV) Enhances the Prognostic Value of the Lung-Specific Graded Prognostic Assessment (GPA) Model.

BACKGROUND: Management of patients afflicted with brain metastasis requires tailoring of therapeutic strategies based on survival expectations. Therefore, the development of prognostic indices is of critical importance in this patient population. OBJECTIVE: To determine whether the cumulative intracranial tumor volume (CITV) of brain metastasis augments the prognostic value of the lung-specific Graded Prognostic Assessment (GPA) index. METHODS: Patient data were derived from 365 lung cancer patients with brain metastasis who were consecutively treated with stereotactic radiosurgery at the University of California, San Diego/San Diego Gamma Knife Center. CITV was analyzed to determine the volume cutoff that maximized sensitivity and specificity for 1-year survival. Multivariate Cox proportional hazard modeling was performed, and overall survival was estimated by the Kaplan-Meier method risk stratifying with or without this optimal CITV. The prognostic value of these models (lung-specific GPA ± CITV) was quantitatively compared with the use of net reclassification improvement (>0) and integrated discrimination improvement. RESULTS: For the University of California, San Diego/San Diego Gamma Knife Center cohort, the CITV cutoff that had the greatest survival discrimination at 1 year was 4 cm. The addition of CITV to the lung-specific GPA indexes significantly improved the prognostic value of lung-specific GPA, with net reclassification improvement >0 of 0.430 (95% confidence interval, 0.228-0.629) and integrated discrimination improvement of 0.029 (95% confidence interval, 0.004-0.073). These findings were validated in an independent cohort of 1638 lung cancer patients with brain metastasis who were treated with stereotactic radiosurgery at the Katsuta Hospital Mito Gamma House in Japan. CONCLUSION: In independent cohorts, the addition of CITV to the lung-specific GPA index significantly improved the prognostic value of this index. ABBREVIATIONS: AUC, area under the receiver-operating characteristic curveBM, brain metastasisCITV, cumulative intracranial tumor volumeds-GPA, disease-specific Graded Prognostic AssessmentGPA, Graded Prognostic AssessmentIDI, integrated discrimination improvementKHMGH, Katsuta Hospital Mito Gamma HouseKPS, Karnofsky Performance StatusNRI, net reclassification improvementROC, receiver-operating characteristic curveSRS, stereotactic radiosurgeryUCSD/SDGKC, University of California, San Diego/San Diego Gamma Knife Center.

Thirty-Day Perioperative Outcomes in Spinal Fusion by Specialty Within the NSQIP Database.

STUDY DESIGN: Cross-sectional analysis of the American College of Surgeons' National Surgical Quality Improvement Program database between 2005 and 2011. OBJECTIVE: To determine whether differences exist in 30-day rate of return to the operating room, mortality, and other perioperative outcomes for spinal fusion by specialty. SUMMARY OF BACKGROUND DATA: Although both neurosurgeons and orthopedic surgeons perform spinal fusions, it is unclear whether surgeon specialty impacts perioperative outcomes. METHODS: Unadjusted bivariate analysis was performed to determine whether outcomes differed by surgeon specialty. A Bonferroni correction was applied to account for multiple comparisons. For outcomes with a statistically significant association, further multivariate analysis was performed. RESULTS: A total of 9719 patients receiving a spinal fusion were identified. Of them, 54.0% had their operation completed by a neurosurgeon. Orthopedic surgeons had practices with a greater percentage of lumbar spine cases (76.0% vs. 65.0%, P < 0.001). There was not a statistically significant difference in the number of levels fused or operative technique used between specialties. There was no difference in the majority of perioperative outcomes between orthopedic surgeons and neurosurgeons including death, rate of return to the operating room, and other complications associated with significant morbidity. On unadjusted analysis, it was found that neurosurgeons were associated with a decreased incidence of operations requiring blood transfusion relative to orthopedic surgeons (8.3% vs. 14.6%, P < 0.001). This trend persisted on multivariate analysis controlling for preoperative hematocrit, history of bleeding disorder, anatomical location of the operation, number of levels fused, operative technique, demographics, and comorbidities (odds ratio, 0.49; 95% confidence interval, 0.43-0.57). CONCLUSION: Spine surgeons, regardless of specialty, seem to achieve equivalent outcomes on measured metrics of mortality, 30-day readmission, and surgical site infection. Observed differences in blood transfusion rates by specialty were noted, but the cause of this difference is unclear and warrants further investigation to assess the impact of this difference, if any, on patient outcomes and cost. LEVEL OF EVIDENCE: 3.

Incidence and predictors of 30-day readmission for patients discharged home after craniotomy for malignant supratentorial tumors in California (1995-2010).

OBJECT: Hospital readmission within 30 days of discharge is a major contributor to the high cost of health care in the US and is also a major indicator of patient care quality. The purpose of this study was to investigate the incidence, causes, and predictors of 30-day readmission following craniotomy for malignant supratentorial tumor resection. METHODS: The longitudinal California Office of Statewide Health Planning & Development inpatient-discharge administrative database is a data set that consists of 100% of all inpatient hospitalizations within the state of California and allows each patient to be followed throughout multiple inpatient hospital stays, across multiple institutions, and over multiple years (from 1995 to 2010). This database was used to identify patients who underwent a craniotomy for resection of primary malignant brain tumors. Causes for unplanned 30-day readmission were identified by principle ICD-9 diagnosis code and multivariate analysis was used to determine the independent effect of various patient factors on 30-day readmissions. RESULTS: A total of 18,506 patients received a craniotomy for the treatment of primary malignant brain tumors within the state of California between 1995 and 2010. Four hundred ten patients (2.2%) died during the index surgical admission, 13,586 patients (73.4%) were discharged home, and 4510 patients (24.4%) were transferred to another facility. Among patients discharged home, 1790 patients (13.2%) were readmitted at least once within 30 days of discharge, with 27% of readmissions occurring at a different hospital than the initial surgical institution. The most common reasons for readmission were new onset seizure and convulsive disorder (20.9%), surgical infection of the CNS (14.5%), and new onset of a motor deficit (12.8%). Medi-Cal beneficiaries were at increased odds for readmission relative to privately insured patients (OR 1.52, 95% CI 1.20-1.93). Patients with a history of prior myocardial infarction were at an increased risk of readmission (OR 1.64, 95% CI 1.06-2.54) as were patients who developed hydrocephalus (OR 1.58, 95% CI 1.20-2.07) or venous complications during index surgical admission (OR 3.88, 95% CI 1.84-8.18). CONCLUSIONS: Using administrative data, this study demonstrates a baseline glioma surgery 30-day readmission rate of 13.2% in California for patients who are initially discharged home. This paper highlights the medical histories, perioperative complications, and patient demographic groups that are at an increased risk for readmission within 30 days of home discharge. An analysis of conditions present on readmission that were not present at the index surgical admission, such as infection and seizures, suggests that some readmissions may be preventable. Discharge planning strategies aimed at reducing readmission rates in neurosurgical practice should focus on patient groups at high risk for readmission and comprehensive discharge planning protocols should be implemented to specifically target the mitigation of potentially preventable conditions that are highly associated with readmission.

Long-term outcomes of patients with nonsurgically managed uncomplicated appendicitis.

BACKGROUND: Emerging literature has supported the safety of nonoperative management of uncomplicated appendicitis. STUDY DESIGN: Patients with emergent, uncomplicated appendicitis were identified by appropriate ICD-9 diagnosis codes in the California Office of Statewide Health Planning and Development database from 1997 to 2008. Rates of treatment failure, recurrence, and perforation after nonsurgical management were calculated. Factors associated with treatment failure, recurrence, and perforation were identified using multivariable logistic regression. Mortality, length of stay, and total charges were compared between treatment cohorts using matched propensity score analysis. RESULTS: Of 231,678 patients with uncomplicated appendicitis, the majority (98.5%) were managed operatively. Of the 3,236 nonsurgically managed patients who survived to discharge without an interval appendectomy, 5.9% and 4.4% experienced treatment failure or recurrence, respectively, during a median follow-up of more than 7 years. There were no mortalities associated with treatment failure or recurrence. The risk of perforation after discharge was approximately 3%. Using multivariable analysis, race and age were significantly associated with the odds of treatment failure. Sex, age, and hospital teaching status were significantly associated with the odds of recurrence. Age and hospital teaching status were significantly associated with the odds of perforation. Matched propensity score analysis indicated that after risk adjustment, mortality rates (0.1% vs 0.3%; p = 0.65) and total charges ($23,243 vs $24,793; p = 0.70) were not statistically different between operative and nonoperative patients; however, length of stay was significantly longer in the nonoperative treatment group (2.1 days vs 3.2 days; p < 0.001). CONCLUSIONS: This study suggests that nonoperative management of uncomplicated appendicitis can be safe and prompts additional investigations. Comparative effectiveness research using prospective randomized studies can be particularly useful.

Long-term follow-up of unruptured intracranial aneurysms repaired in California.

OBJECT: Using a database that enabled longitudinal follow-up, the authors assessed the long-term outcomes of unruptured cerebral aneurysms repaired by clipping or coiling. METHODS: An observational analysis of the California Office of Statewide Health Planning and Development (OSHPD) database, which follows patients longitudinally in time and through multiple hospitalizations, was performed for all patients initially treated for an unruptured cerebral aneurysm in the period from 1998 to 2005 and with follow-up data through 2009. RESULTS: Nine hundred forty-four cases (36.5%) were treated with endovascular coiling, 1565 cases (60.5%) were surgically clipped, and 76 cases were treated with both coiling and clipping. There was no significant difference in any demographic variable between the two treatment groups except for age (median: 55 years for the clipped group, 58 years for the coiled group, p < 0.001). Perioperative (30-day) mortality was 1.1% in patients with coiled aneurysms compared with 2.3% in those with clipped aneurysms (p = 0.048). The median follow-up was 7 years (range 4-12 years). At the last follow-up, 153 patients (16.2%) in the coiled group had died compared with 244 (15.6%) in the clipped group (p = 0.693). The adjusted hazard ratio for death at the long-term follow-up was 1.14 (95% CI 0.9-1.4, p = 0.282) for patients with endovascularly treated aneurysms. The incidence of intracranial hemorrhage was similar in the two treatment groups (5.9% clipped vs 4.8% coiled, p = 0.276). One hundred ninety-three patients (20.4%) with coiled aneurysms underwent additional hospitalizations for aneurysm repair procedures compared with only 136 patients (8.7%) with clipped aneurysms (p < 0.001). Cumulative hospital costs per patient for admissions involving aneurysm repair procedures were greater in the clipped group (median cost $98,260 vs $81,620, p < 0.001) through the follow-up. CONCLUSIONS: For unruptured cerebral aneurysms, an observed perioperative survival advantage for endovascular coiling relative to that for surgical clipping was lost on long-term follow-up, according to data from an administrative database of patients who were not randomly allocated to treatment type. A cost advantage of endovascular treatment was maintained even though endovascularly treated patients were more likely to undergo subsequent hospitalizations for additional aneurysm repair procedures. Rates of aneurysm rupture following treatment were similar in the two groups.

Gross-total resection outcomes in an elderly population with glioblastoma: a SEER-based analysis.

OBJECT: There is limited information on the relationship between patient age and the clinical benefit of resection in patients with glioblastoma. The purpose of this study was to use a population-based database to determine whether patient age influences the frequency that gross-total resection (GTR) is performed, and also whether GTR is associated with survival difference in different age groups. METHODS: The authors identified 20,705 adult patients with glioblastoma in the Surveillance, Epidemiology, and End Results (SEER) registry (1998-2009). Surgical practice patterns were defined by the categories of no surgery, subtotal resection (STR), and GTR. Kaplan-Meier and multivariate Cox regression analyses were used to assess the pattern of surgical practice and overall survival. RESULTS: The frequency that GTR was achieved in patients with glioblastoma decreased in a stepwise manner as a function of patient age (from 36% [age 18-44 years] to 24% [age ≥ 75]; p < 0.001). For all age groups, glioblastoma patients who were selected for and underwent GTR showed a 2- to 3-month improvement in overall survival (p < 0.001) relative to those who underwent STR. These trends remained true after a multivariate analysis that incorporated variables including ethnicity, sex, year of diagnosis, tumor size, tumor location, and radiotherapy status. CONCLUSIONS: Gross-total resection is associated with improved overall survival, even in elderly patients with glioblastoma. As such, surgical decisions should be individually tailored to the patient rather than an adherence to age as the sole clinical determinant.