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Yan Michael Li, Dima Suki, Kenneth Hess and Raymond Sawaya

OBJECT

Glioblastoma multiforme (GBM) is the most common and deadliest primary brain tumor. The value of extent of resection (EOR) in improving survival in patients with GBM has been repeatedly confirmed, with more extensive resections providing added advantages. The authors reviewed the survival of patients with significant EORs and assessed the relative benefit/risk of resecting 100% of the MRI region showing contrast-enhancement with or without additional resection of the surrounding FLAIR abnormality region, and they assessed the relative benefit/risk of performing this additional resection.

METHODS

The study cohort included 1229 patients with histologically verified GBM in whom ≥ 78% resection was achieved at The University of Texas MD Anderson Cancer Center between June 1993 and December 2012. Patients with > 1 tumor and those 80 years old or older were excluded. The survival of patients having 100% removal of the contrast-enhancing tumor, with or without additional resection of the surrounding FLAIR abnormality region, was compared with that of patients undergoing 78% to < 100% EOR of the enhancing mass. Within the first subgroup, the survival durations of patients with and without resection of the surrounding FLAIR abnormality were subsequently compared. The data on patients and their tumor characteristics were collected prospectively. The incidence of 30-day postoperative complications (overall and neurological) was noted.

RESULTS

Complete resection of the T1 contrast-enhancing tumor volume was achieved in 876 patients (71%). The median survival time for these patients (15.2 months) was significantly longer than that for patients undergoing less than complete resection (9.8 months; p < 0.001). This survival advantage was achieved without an increase in the risk of overall or neurological postoperative deficits and after correcting for established prognostic factors including age, Karnofsky Performance Scale score, preoperative contrast-enhancing tumor volume, presence of cyst, and prior treatment status (HR 1.53, 95% CI 1.33–1.77, p < 0.001). The effect remained essentially unchanged when data from previously treated and previously untreated groups of patients were analyzed separately. Additional analyses showed that the resection of ≥ 53.21% of the surrounding FLAIR abnormality beyond the 100% contrast-enhancing resection was associated with a significant prolongation of survival compared with that following less extensive resections (median survival times 20.7 and 15.5 months, respectively; p < 0.001). In the multivariate analysis, the previously treated group with < 53.21% resection had significantly shorter survival than the 3 other groups (that is, previously treated patients who underwent FLAIR resection ≥ 53.21%, previously untreated patients who underwent FLAIR resection < 53.21%, and previously untreated patients who underwent FLAIR resection ≥ 53.21%); the previously untreated group with ≥ 53.21% resection had the longest survival.

CONCLUSIONS

What is believed to be the largest single-center series of GBM patients with extensive tumor resections, this study supports the established association between EOR and survival and presents additional data that pushing the boundary of a conventional 100% resection by the additional removal of a significant portion of the FLAIR abnormality region, when safely feasible, may result in the prolongation of survival without significant increases in overall or neurological postoperative morbidity. Additional supportive evidence is warranted.

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Benjamin D. Schanker, Brian P. Walcott, Brian V. Nahed, Kristopher T. Kahle, Yan Michael Li and Jean-Valery C. E. Coumans

Chiari malformations (Types I–IV) are abnormalities of the posterior fossa that affect the cerebellum, brainstem, and the spinal cord with prevalence rates of 0.1%–0.5%. Case reports of familial aggregation of Chiari malformation, twin studies, cosegregation of Chiari malformation with known genetic conditions, and recent gene and genome-wide association studies provide strong evidence of the genetic underpinnings of familial Chiari malformation. The authors report on a series of 3 family pairs with Chiari malformation Type I: 2 mother-daughter pairs and 1 father-daughter pair. The specific genetic causes of familial Chiari malformation have yet to be fully elucidated. The authors review the literature and discuss several candidate genes. Recent advances in the understanding of the genetic influences and pathogenesis of familial Chiari malformation are expected to improve management of affected patients and monitoring of at-risk family members.

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Keaton Piper, Hanna Algattas, Ian A. DeAndrea-Lazarus, Kristopher T. Kimmell, Yan Michael Li, Kevin A. Walter, Howard J. Silberstein and G. Edward Vates

OBJECTIVE

Patients undergoing spinal surgery are at risk for developing venous thromboembolism (VTE). The authors sought to identify risk factors for VTE in these patients.

METHODS

The American College of Surgeons National Surgical Quality Improvement Project database for the years 2006–2010 was reviewed for patients who had undergone spinal surgery according to their primary Current Procedural Terminology code(s). Clinical factors were analyzed to identify associations with VTE.

RESULTS

Patients who underwent spinal surgery (n = 22,434) were identified. The rate of VTE in the cohort was 1.1% (pulmonary embolism 0.4%; deep vein thrombosis 0.8%). Multivariate binary logistic regression analysis revealed 13 factors associated with VTE. Preoperative factors included dependent functional status, paraplegia, quadriplegia, disseminated cancer, inpatient status, hypertension, history of transient ischemic attack, sepsis, and African American race. Operative factors included surgery duration > 4 hours, emergency presentation, and American Society of Anesthesiologists Class III–V, whereas postoperative sepsis was the only significant postoperative factor. A risk score was developed based on the number of factors present in each patient. Patients with a score of ≥ 7 had a 100-fold increased risk of developing VTE over patients with a score of 0. The receiver-operating-characteristic curve of the risk score generated an area under the curve of 0.756 (95% CI 0.726–0.787).

CONCLUSIONS

A risk score based on race, preoperative comorbidities, and operative characteristics of patients undergoing spinal surgery predicts the postoperative VTE rate. Many of these risks can be identified before surgery. Future protocols should focus on VTE prevention in patients who are predisposed to it.