Faculty Bibliography

The purpose of this study is to determine the role of computed tomography (CT) on the decision to administer blood transfusions in patients with abdominopelvic hemorrhage (trauma, surgery, invasive procedure, and spontaneous) and to determine the clinical parameters most likely to influence the decision to administer blood transfusions in patients with spontaneous abdominopelvic hemorrhage. In this IRB approved and HIPPA compliant study, retrospective analysis was performed on 298 patients undergoing abdominal and pelvic CT for suspected abdominopelvic hemorrhage and the CT reports and electronic medical records were reviewed. Odds ratios and 95% CI were calculated to compare the odds of abdominopelvic hemorrhage and transfusion for categorical and continuous predictors. The presence of abdominopelvic hemorrhage by CT was significantly associated with blood transfusions for trauma patients (p-value <0.0001) only. 106 patients with suspected spontaneous abdominopelvic hemorrhage had the lowest CT positivity rate (n = 23, 21.7%) but the highest blood transfusion rate (n = 62, 58.5%) compared to the patients with abdominopelvic hemorrhage from known preceding causes. In patients with spontaneous abdominopelvic hemorrhage, low hemoglobin and hematocrit levels immediately prior to obtaining the CT study were more predictive for receiving a blood transfusion (p-value <0.0001) than the presence of hemorrhage by CT. CT positivity is strongly correlated with the decision to administer blood transfusions for patients with abdominopelvic hemorrhage from trauma, indicating that CT studies play a significant role in determining the clinical management of trauma patients. For patients with spontaneous abdominopelvic hemorrhage, the decision to transfuse depends not on the CT study but on the patient's hemoglobin and hematocrit levels. CT studies should therefore not be performed for the sole purpose of determining the need for blood transfusion in patients with spontaneous abdominopelvic hemorrhage.

STUDY DESIGN/METHODS:An electronic survey administered to Scoliosis Research Society membership. OBJECTIVE:To characterize surgeon views regarding proximal junctional kyphosis (PJK) and proximal junctional failure (PJF) management providing the framework in which a PJK/PJF classification system and treatment guidelines could be established. SUMMARY OF BACKGROUND DATA/BACKGROUND:PJK/PJF are common complications of adult spinal deformity surgery. To date, there is no consensus on PJK/PJF definitions, classification, and indications for revision surgery. There is a paucity of data on deformity surgeon practice pattern variations and consensus opinion on treatment and prevention. METHODS:An electronic 19-question survey regarding PJK/PJF was administered to members of the Scoliosis Research Society who treat adult spinal deformity. Determinants included the surgeons' type of practice, number of years in practice, agreement with given PJK/PJF definitions, importance of key factors influencing prevention and revision, prevention methods currently used, and the importance of developing a classification system. RESULTS:A total of 226 surgeons responded (38.8% response rate). Both 44.4% of surgeons selected "extremely important" and 40.8% selected "very important" that PJK in adult spinal deformity surgery is a very important issue and that a Scoliosis Research Society PJK/PJF classification system and guidelines for detection and prevention of PJK/PJF is a "must have" (18.1%) and "very likely helpful" (31.9%). Both 86.2% and 90.7% of surgeons agreed with the provided definitions of PJK and PJF, respectively. Top 5 revision indications included neurological deficit, severe focal pain, translation or subluxation fracture, a change in kyphosis angle of greater than 30°, chance fracture, spondylolisthesis greater than 6 mm, and instrumentation prominence. The majority of respondents use a PJK/PJF prevention strategy 60% of the time or more, the most common were terminal rod contour, preoperative bone mineral density testing, and frequent radiographical studies during first 3 months postoperative, preoperative bone mineral density medication for low bone mineral density. CONCLUSION/CONCLUSIONS:The results of this study provide insight from the practicing surgeons' perspective of the management of PJK and PJF that may aid in the validation of current definitions and consensus-based treatment decisions and prevention guidelines. LEVEL OF EVIDENCE/METHODS:5.

OBJECT Resection is an appealing therapy for brain arteriovenous malformations (AVMs) because of its high cure rate, low complication rate, and immediacy, and has become the first-line therapy for many AVMs. To clarify safety, efficacy, and outcomes associated with AVM resection in the aftermath of A Randomized Trial of Unruptured Brain AVMs (ARUBA), the authors reviewed their experience with low-grade AVMs-the most favorable AVMs for surgery and the ones most likely to have been selected for treatment outside of ARUBA's randomization process. METHODS A prospective AVM registry was searched to identify patients with Spetzler-Martin Grade I and II AVMs treated using resection during a 16-year period. RESULTS Of the 232 surgical patients included, 120 (52%) presented with hemorrhage, 33% had Spetzler-Martin Grade I, and 67% had Grade II AVMs. Overall, 99 patients (43%) underwent preoperative embolization, with unruptured AVMs embolized more often than ruptured AVMs. AVM resection was accomplished in all patients and confirmed angiographically in 218 patients (94%). There were no deaths among patients with unruptured AVMs. Good outcomes (modified Rankin Scale [mRS] score 0-1) were found in 78% of patients, with 97% improved or unchanged from their preoperative mRS scores. Patients with unruptured AVMs had better functional outcomes (91% good outcome vs 65% in the ruptured group, p = 0.0008), while relative outcomes were equivalent (98% improved/unchanged in patients with ruptured AVMs vs 96% in patients with unruptured AVMs). CONCLUSIONS Surgery should be regarded as the "gold standard" therapy for the majority of low-grade AVMs, utilizing conservative embolization as a preoperative adjunct. High surgical cure rates and excellent functional outcomes in patients with both ruptured and unruptured AVMs support a dominant surgical posture for low-grade AVMS, with radiosurgery reserved for risky AVMs in deep, inaccessible, and highly eloquent locations. Despite the technological advances in endovascular and radiosurgical therapy, surgery still offers the best cure rate, lowest risk profile, and greatest protection against hemorrhage for low-grade AVMs. ARUBA results are influenced by a low randomization rate, bias toward nonsurgical therapies, a shortage of surgical expertise, a lower rate of complete AVM obliteration, a higher rate of delayed hemorrhage, and short study duration. Another randomized trial is needed to reestablish the role of surgery in unruptured AVM management.

OBJECT/OBJECTIVE:Vascular endothelial growth factor (VEGF) is the major proangiogenic factor in many solid tumors. Vascular endothelial growth factor receptor (VEGFR) is expressed in abundance in pediatric patients with medulloblastoma and is associated with tumor metastasis, poor prognosis, and proliferation. Gadolinium enhancement on MRI has been suggested to have prognostic significance for some tumors. The association of VEGF/VEGFR and Gd enhancement in medulloblastoma has never been closely examined. The authors therefore sought to evaluate whether Gd-enhancing medulloblastomas have higher levels of VEGFR and CD31. Outcomes and survival in patients with enhancing and nonenhancing tumors were also compared. METHODS:A retrospective analysis of patients with enhancing, nonenhancing, and partially enhancing medulloblastomas was performed. Primary end points included risk stratification, extent of resection, and perioperative complications. A cohort of 3 enhancing and 3 nonenhancing tumors was selected for VEGFR and CD31 analysis as well as microvessel density measurements. RESULTS:Fifty-eight patients were analyzed, and 20.7% of the medulloblastomas in these patients were nonenhancing. Enhancing medulloblastomas exhibited strong VEGFR1/2 and CD31 expression relative to nonenhancing tumors. There was no significant difference in perioperative complications or patient survival between the 2 groups. CONCLUSIONS:These results suggest that in patients with medulloblastoma the presence of enhancement on MRI may correlate with increased vascularity and angiogenesis, but does not correlate with worse patient prognosis in the short or long term.

Study Design Systematic review. Clinical Questions Compared with no stimulation, does electrical stimulation promote bone fusion after lumbar spinal fusion procedures? Does the effect differ based on the type of electrical stimulation used? Methods Electronic databases and reference lists of key articles were searched up to October 15, 2013, to identify randomized controlled trials (RCTs) comparing the effect of electrical stimulation to no electrical stimulation on fusion rates after lumbar spinal fusion for the treatment of degenerative disease. Two independent reviewers assessed the strength of evidence using the Grades of Recommendation Assessment, Development and Evaluation (GRADE) criteria. Results Six RCTs met the inclusion criteria. The following types of electrical stimulation were investigated: direct current (three studies), pulsed electromagnetic field (three studies), and capacitive coupling (one study). The control groups consisted of no stimulation (two studies) or placebo (four studies). Marked heterogeneity in study populations, characteristics, and design prevented a meta-analysis. Regardless of the type of electrical stimulation used, cumulative incidences of fusion varied widely across the RCTs, ranging from 35.4 to 90.6% in the intervention groups and from 33.3 to 81.9% in the control groups across 9 to 24 months of follow-up. Similarly, when stratified by the type of electrical stimulation used, fusion outcomes from individual studies varied, leading to inconsistent and conflicting results. Conclusion Given the inconsistency in study results, possibly due to heterogeneity in study populations/characteristics and quality, we are unable to conclude that electrical stimulation results in better fusion outcomes compared with no stimulation. The overall strength of evidence for the conclusions is low.

OBJECT/OBJECTIVE:The most common indications for circumferential cervical decompression and fusion are cervical spondylotic myelopathy (CSM) and cervical osteomyelitis (COM). Currently, the informed consent process prior to circumferential cervical fusion surgery is not different for these two groups of patients, as details of their diagnosis-specific risk profiles have not been quantified. The authors compared two patient cohorts with either CSM or COM treated using circumferential fusion. They sought to quantify perioperative morbidity and postoperative mortality in these two groups to assist with a diagnosis-specific informed consent process for future patients undergoing this type of surgery. METHODS:Perioperative and follow-up data from two cohorts of patients who had undergone circumferential cervical decompression and fusion were analyzed. Estimated blood loss (EBL), length of stay (LOS), perioperative complications, hospital readmission, 30-day reoperation rates, change in Nurick grade, and mortality were compared between the two groups. RESULTS:Twenty-two patients were in the COM cohort, and 24 were in the CSM cohort. Complications, hospital readmission, 30-day reoperation rates, EBL, and mortality were not statistically different, although patients with COM trended higher in each of these categories. There was a significantly greater LOS (p < 0.001) in the COM group and greater improvement in Nurick grade in the CSM group (p < 0.001). CONCLUSIONS:When advising patients undergoing circumferential fusion about perioperative risk factors, it is important for those with COM to know that they are likely to have a higher rate of complications and mortality than those with CSM who are undergoing similar surgery. Furthermore, COM patients have less neurological improvement than CSM patients after surgery. This information may be useful to surgeons and patients in providing appropriate informed consent during preoperative planning.

STUDY DESIGN/METHODS:Retrospective study. PURPOSE/OBJECTIVE:The aim of this study was to evaluate the clinical management and outcomes of patients who underwent surgical intervention for metastatic colorectal adenocarcinoma of the spine. OVERVIEW OF LITERATURE/BACKGROUND:Gastrointestinal (GI) cancer metastasis to the spine are relatively rare and represent later manifestations of the disease. Studies and reports on the outcomes of patients who undergo surgery for spinal metastasis of GI origin are scarce. METHODS:A retrospective chart review of all patients who underwent surgery for spinal metastasis of colorectal origin was performed. Four patients were identified. Patient characteristics, outcomes, and survival were analyzed. RESULTS:Two patients experienced improvement in pain or myelopathic symptoms. Although the mean survival was 15.3 months, this average included a patient still living at 57.1 months. The mean survival was just 1.3 months for the 3 patients who expired. CONCLUSIONS:In certain cases, symptomatic improvement with prolonged survival is possible after surgery for metastatic spinal lesions of colorectal origin; however, survival is poor in the majority of cases.

OBJECT/OBJECTIVE:Smoking is one of the leading causes of preventable morbidity and death in the U.S. and has been associated with perioperative complications. In this study, the authors examined the effects of smoking on perioperative outcomes and pseudarthrosis rates following anterior cervical corpectomy. METHODS:All adult patients from 2006 to 2011 who underwent anterior cervical corpectomy were identified. Patients were categorized into 3 groups: patients who never smoked (nonsmokers), patients who quit for at least 1 year (quitters), and patients who continue to smoke (current smokers). Demographic, medical, and surgical covariates were collected. Multivariate analysis was used to define the relationship between smoking and blood loss, 30-day complications, length of hospital stay, and pseudarthrosis. RESULTS:A total of 160 patients were included in the study. Of the 160 patients, 49.4% were nonsmokers, 25.6% were quitters, and 25.0% were current smokers. The overall 30-day complication rate was 20.0%, and pseudarthrosis occurred in 7.6% of patients. Mean blood loss was 368.3 ml and mean length of stay was 6.5 days. Current smoking status was significantly associated with higher complication rates (p < 0.001) and longer lengths of stay (p < 0.001); current smoking status remained an independent risk factor for both outcomes after multivariate logistic regression analysis. The complications that were experienced in current smokers were mostly infections (76.5%), and this proportion was significantly greater than in nonsmokers and quitters (p = 0.013). Current smoking status was also an independent risk factor for pseudarthrosis at 1-year follow-up (p = 0.012). CONCLUSIONS:Smoking is independently associated with higher perioperative complications (especially infectious complications), longer lengths of stay, and higher rates of pseudarthrosis in patients undergoing anterior cervical corpectomy.

OBJECT/OBJECTIVE:Glioblastoma is the most aggressive and diffusely infiltrative primary brain tumor. Recurrence is expected and is extremely difficult to treat. Over the past decade, the accumulation of knowledge regarding the molecular and genetic profile of glioblastoma has led to numerous molecularly targeted therapies. This article aims to review the literature and highlight the mechanisms and efficacies of molecularly targeted therapies for recurrent glioblastoma. METHODS:A systematic search was performed with the phrase "(name of particular agent) and glioblastoma" as a search term in PubMed to identify all articles published up until 2014 that included this phrase in the title and/or abstract. The references of systematic reviews were also reviewed for additional sources. The review included clinical studies that comprised at least 20 patients and reported results for the treatment of recurrent glioblastoma with molecular targeted therapies. RESULTS:A total of 42 articles were included in this review. In the treatment of recurrent glioblastoma, various targeted therapies have been tested over the past 10-15 years. The targets of interest include epidermal growth factor receptor, vascular endothelial growth factor receptor, platelet-derived growth factor receptor, Ras pathway, protein kinase C, mammalian target of rapamycin, histone acetylation, and integrins. Unfortunately, the clinical responses to most available targeted therapies are modest at best. Radiographic responses generally range in the realm of 5%-20%. Progression-free survival at 6 months and overall survival were also modest with the majority of studies reporting a 10%-20% 6-month progression-free survival and 5- to 8-month overall survival. There have been several clinical trials evaluating the use of combination therapy for molecularly targeted treatments. In general, the outcomes for combination therapy tend to be superior to single-agent therapy, regardless of the specific agent studied. CONCLUSIONS:Recurrent glioblastoma remains very difficult to treat, even with molecular targeted therapies and anticancer agents. The currently available targeted therapy regimens have poor to modest activity against recurrent glioblastoma. As newer agents are actively being developed, combination regimens have provided the most promising results for improving outcomes. Targeted therapies matched to molecular profiles of individual tumors are predicted to be a critical component necessary for improving efficacy in future trials.

OBJECT/OBJECTIVE:Long-segment spinal instrumentation ending at the sacrum places substantial biomechanical stress on sacral screws. Iliac (pelvic) screws relieve some of this stress by supplementing the caudal fixation. It remains an open question whether there is any clinically significant difference in sacropelvic fixation with bilateral versus unilateral iliac screws. The primary purpose of this study was to compare clinical and radiographic complications in the use of bilateral versus unilateral iliac screw fixation. METHODS:The authors retrospectively reviewed 102 consecutive spinal fixation cases that extended to the pelvis at a single institution (University of California, San Francisco) in the period from 2005 to 2012 performed by the senior authors. Charts were reviewed for the following complications: reoperation, L5-S1 pseudarthrosis, sacral insufficiency fracture, hardware prominence, iliac screw loosening, and infection. The t-test, Pearson chi-square test, and Fisher exact test were used to determine statistical significance. RESULTS:The mean follow-up was 31 months. Thirty cases were excluded: 12 for inadequate follow-up, 15 for lack of L5-S1 interbody fusion, and 3 for preoperative osteomyelitis. The mean age among the 72 remaining cases was 62 years (range 39-79 years). Forty-six patients underwent unilateral and 26 bilateral iliac screw fixation. Forty-one percent (n = 19) of the unilateral cases and 50% (n = 13) of the bilateral cases were treated with reoperation (p = 0.48). In addition, 13% (n = 6) of the unilateral and 19% (n = 5) of the bilateral cases developed L5-S1 pseudarthrosis (p = 0.51). There were no sacral insufficiency fractures. Thirteen percent (n = 6) of the unilateral and 7.7% (n = 2) of the bilateral cases developed postoperative infection (p = 0.70). CONCLUSIONS:In a retrospective single-institution study, single versus dual pelvic screws led to comparable rates of reoperation, iliac screw removal, postoperative infection, pseudarthrosis, and sacral insufficiency fractures. For spinopelvic fixation, placing bilateral (vs unilateral) pelvic screws produced no added clinical benefit in most cases.