Primary bone tumors of the spine are rare entities with a poor prognosis if left untreated. En bloc excision is the preferred surgical approach to minimize the rate of recurrence. Paraspinal primary bone tumors are even less common. In this technical note the authors present an approach to the en bloc resection of primary bone tumors of the paraspinal thoracic region with posterior vertebral body hemiosteotomies and lateral thoracotomy. They also describe 2 illustrative cases.
Mauricio J. Avila, Jesse Skoch, Vernard S. Fennell, Sheri K. Palejwala, Christina M. Walter, Samuel Kim and Ali A. Baaj
Peyton L. Nisson, Salman A. Fard, Christina M. Walter, Cameron M. Johnstone, Michael A. Mooney, Ali Tayebi Meybodi, Michael Lang, Helen Kim, Heidi Jahnke, Denise J. Roe, Travis M. Dumont, G. Michael Lemole Jr., Robert F. Spetzler and Michael T. Lawton
The objective of this study was to evaluate the existing Spetzler-Martin (SM), Spetzler-Ponce (SP), and Lawton-Young (LY) grading systems for cerebellar arteriovenous malformations (AVMs) and to propose a new grading system to estimate the risks associated with these lesions.
Data for patients with cerebellar AVMs treated microsurgically in two tertiary medical centers were retrospectively reviewed. Data from patients at institution 1 were collected from September 1999 to February 2013, and at institution 2 from October 2008 to October 2015. Patient outcomes were classified as favorable (modified Rankin Scale [mRS] score 0–2) or poor (mRS score 3–6) at the time of discharge. Using chi-square and logistic regression analysis, variables associated with poor outcomes were assigned risk points to design the proposed grading system. The proposed system included neurological status prior to treatment (poor, +2 points), emergency surgery (+1 point), age > 60 years (+1 point), and deep venous drainage (deep, +1 point). Risk point totals of 0–1 comprised grade 1, 2–3 grade 2, and 4–5 grade 3.
A total of 125 cerebellar AVMs of 1328 brain AVMs were reviewed in 125 patients, 120 of which were treated microsurgically and included in the study. With our proposed grading system, we found poor outcomes differed significantly between each grade (p < 0.001), while with the SM, SP, and LY grading systems they did not (p = 0.22, p = 0.25, and p = 1, respectively). Logistic regression revealed grade 2 had 3.3 times the risk of experiencing a poor outcome (p = 0.008), while grade 3 had 9.9 times the risk (p < 0.001). The proposed grading system demonstrated a superior level of predictive accuracy (area under the receiver operating characteristic curve [AUROC] of 0.72) compared with the SM, SP, and LY grading systems (AUROC of 0.61, 0.57, and 0.51, respectively).
The authors propose a novel grading system for cerebellar AVMs based on emergency surgery, venous drainage, preoperative neurological status, and age that provides a superior prognostication power than the formerly proposed SM, SP, and LY grading systems. This grading system is clinically predictive of patient outcomes and can be used to better guide vascular neurosurgeons in clinical decision-making.