Chemoprophylactic Anticoagulation After Spine Surgery Does Not Increase Epidural Hematoma Risk: A Propensity-matched Analysis.

STUDY DESIGN: A retrospective cohort study. OBJECTIVE: To calculate the magnitude of any increased risk of epidural hematoma (EDH) associated with chemoprophylactic anticoagulation (chemoprophylaxis), if any. SUMMARY OF BACKGROUND DATA: Chemoprophylaxis for the prevention of venous thromboembolic events may be associated with an increased risk of EDH after spine surgery. MATERIALS AND METHODS: A total of 6869 consecutive spine surgeries performed at our institution were identified, and clinical and demographic data were collected. We identified cases in which symptomatic EDHs were evacuated within 30 days postoperatively. Patients receiving chemoprophylaxis and controls were matched using K-nearest neighbor propensity score matching to calculate the effect of anticoagulation on the rate of postoperative EDH. RESULTS: After propensity score matching, 1071 patients who received chemoprophylaxis were matched to 1585 controls. Propensity scores were well balanced between populations (Rubin B=20.6, Rubin R=1.05), and an 89.6% reduction in bias was achieved, with a remaining mean bias of 3.2%. The effect of chemoprophylaxis on EDH was insignificant ( P =0.294). Symptomatic EDH was independently associated with having a transfusion [odds ratio (OR)=7.30 (1.15, 46.20), P =0.035], having thoracic-level surgery [OR=41.19 (3.75, 452.4), P =0.002], and increasing body mass index [OR=1.44 (1.04, 1.98), P =0.028] but was not associated with chemoprophylaxis. Five out of 13 patients who developed EDH (38.5%) were receiving some form of anticoagulation, including 1 patient on therapeutic anticoagulation, 1 concurrently on aspirin and chemoprophylaxis, and 2 who were also found to have developed thrombocytopenia postoperatively. The median time on anticoagulation before EDH was 8.1 days. A higher proportion of patients who developed EDH also developed venous thromboembolic events than the general population [38.5% vs. 2.4%, OR=25.34 (9.226, 79.68), P <0.0001], and 1 EDH patient died from pulmonary embolism while off chemoprophylaxis. CONCLUSIONS: Chemoprophylactic anticoagulation did not cause an increase in the rate of spinal EDH in our patient population.

Using machine learning and big data for the prediction of venous thromboembolic events after spine surgery: A single-center retrospective analysis of multiple models on a cohort of 6869 patients.

Objective: Venous thromboembolic event (VTE) after spine surgery is a rare but potentially devastating complication. With the advent of machine learning, an opportunity exists for more accurate prediction of such events to aid in prevention and treatment. Methods: Seven models were screened using 108 database variables and 62 preoperative variables. These models included deep neural network (DNN), DNN with synthetic minority oversampling technique (SMOTE), logistic regression, ridge regression, lasso regression, simple linear regression, and gradient boosting classifier. Relevant metrics were compared between each model. The top four models were selected based on area under the receiver operator curve; these models included DNN with SMOTE, linear regression, lasso regression, and ridge regression. Separate random sampling of each model was performed 1000 additional independent times using a randomly generated training/testing distribution. Variable weights and magnitudes were analyzed after sampling. Results: Using all patient-related variables, DNN using SMOTE was the top-performing model in predicting postoperative VTE after spinal surgery (area under the curve [AUC] =0.904), followed by lasso regression (AUC = 0.894), ridge regression (AUC = 0.873), and linear regression (AUC = 0.864). When analyzing a subset of only preoperative variables, the top-performing models were lasso regression (AUC = 0.865) and DNN with SMOTE (AUC = 0.864), both of which outperform any currently published models. Main model contributions relied heavily on variables associated with history of thromboembolic events, length of surgical/anesthetic time, and use of postoperative chemoprophylaxis. Conclusions: The current study provides promise toward machine learning methods geared toward predicting postoperative complications after spine surgery. Further study is needed in order to best quantify and model real-world risk for such events.

Traumatic Dens Fracture Patients Comprise Distinct Subpopulations Distinguished by Differences in Age, Sex, Injury Mechanism and Severity, and Outcome.

BACKGROUND: Dens fractures are an increasingly common injury, yet their epidemiology and its implications remain underexamined. METHODS: We retrospectively analyzed all traumatic dens fracture patients managed at our institution over a 10-year period, examining demographic, clinical, and outcomes data. Patient subsets were compared across these parameters. RESULTS: Among 303 traumatic dens fracture patients, we observed a bimodal age distribution with a strong goodness of fit centered at age 22.3 ± 5.7 (R = 0.8781) and at 77.7 ± 13.9 (R = 0.9686). A population pyramid demonstrated a bimodal distribution among male patients, but not female patients, which was confirmed with a strong goodness of fit for male patient subpopulations age <35 (R = 0.9791) and age ≥35 (R = 0.8843), but a weaker fit for a second female subpopulation age <35. Both age groups were equally likely to undergo surgery. Patients younger than age 35 were more likely to be male (82.4% vs. 46.9%, odds ratio [OR] = 5.29 [1.54, 17.57], P = 0.0052), have motor vehicle collision as their mechanism of injury (64.7% vs. 14.1%, OR = 11.18 [3.77, 31.77], P < 0.0001), and to have a severe trauma injury severity score (17.6% vs. 2.9%, OR = 7.23 [1.88, 28.88], P = 0.0198). Nevertheless, patients age <35 were less likely to have fracture nonunion at follow (18.2% vs. 53.7%, OR = 0.19 [0.041, 0.76], P = 0.0288). CONCLUSIONS: The dens fracture patient population comprises 2 subpopulations, distinguished by differences in age, sex, injury mechanism and severity, and outcome, with male dens fracture patients demonstrating a bimodal age distribution. Young, male patients were more likely to have high-energy injury mechanisms leading to severe trauma, yet were less likely to have fracture nonunion at follow-up.

Functional Anatomy and Biomechanics of the Craniovertebral Junction.

The craniovertebral junction (CVJ) involves the atlas, axis, and occiput along with the atlanto-occipital and atlantoaxial joints. The anatomy and neural and vascular anatomy of the junction render the CVJ unique. Specialists treating disorders that affect the CVJ must appreciate its intricate anatomy and should be well versed in its biomechanics. This first article in a three-article series provides an overview of the functional anatomy and biomechanics of the CVJ.

Outpatient telemedicine in neurosurgery: 15,677 consecutive encounters in a comparative analysis of its effectiveness and impact on the surgical conversion rate.

OBJECTIVE: The coronavirus disease 2019 (COVID-19) pandemic has necessitated the use of telehealth visits (THVs). The effects on neurosurgical practice have not been well characterized, especially concerning new-patient THVs. Therefore, the authors of this study reviewed their institution's experience with outpatient clinic visits and THVs from before the COVID-19 pandemic to the present to focus on clinical metrics, rates of surgery, and the effects of implementing THVs in order to better understand their implications for clinical practice as more data emerge over time. METHODS: The authors reviewed 15,677 consecutive new outpatient in-person visits (IPVs), THVs, and neurosurgical procedures/cases proceeding from their institution between 2018 and 2022 for trends and associations related to THVs. RESULTS: Among spine patients, there was no difference in the proportion of encounters that led to surgery (surgical conversion rate) between THVs and IPVs (p = 0.49). Among cranial patients, THVs were negatively associated with conversion (OR 0.73, p = 0.03). On average, patients using THVs lived further from the hospital (p < 0.001); however, the patient catchment area appeared unchanged. The median distance to the hospital among THV patients was counterbalanced by a decreased distance for spine patients pursing IPVs (p < 0.001), with no significant change to case volume. There was no change in distance to the hospital among cranial patients. For both cranial and spine patients, surgical conversion was more likely among those who lived a great distance from the hospital if their initial encounter was an IPV (p = 0.007 and < 0.001, respectively). However, there was no relationship between distance from the hospital and surgical conversion among THV patients (p = 0.565). The availability of THVs did not significantly affect follow-up time (p = 0.837). For new patients at IPVs, there was no difference in time to the operating room between cranial and spine cases; for new patients at THVs, however, time to the operating room was significantly faster for cranial cases than for spine cases (p = 0.0018). CONCLUSIONS: Compared to IPVs, THVs lead to decreased surgical conversion for cranial patients but not spine patients. THVs do not appear to increase the catchment area. For patients who live far from the hospital, an IPV is associated with surgical conversion. Surgical conversion is faster following cranial THVs than after spine THVs. THVs did not increase the duration of follow-up.

Advances, Challenges, and Future Directions in the Management of Craniovertebral Junction Pathologies.

In this third article in a 3-article series on the craniocervical junction, we define the terms "basilar impression," "cranial settling," "basilar invagination," and "platybasia," noting that these terms are often used interchangeably but represent distinct entities. We then provide examples that represent these pathologies and treatment paradigms. Finally, we discuss the challenges and future direction in the craniovertebral junction surgery space.

An Approach to Managing Disorders Affecting the Craniovertebral Junction.

The craniovertebral junction (CVJ), or the "first junction," can be affected by a variety of pathological states. Some of these conditions could represent a gray area in that they can be treated by general neurosurgeons or such specialists as skull base or spinal surgeons. However, some conditions are best managed with a multidisciplinary approach. The importance of in-depth knowledge of the anatomy and biomechanics of this junction cannot be overemphasized. Identifying what represents clinical stability or instability is key to successful diagnosis and, hence, treatment. In this report, the second in a 3-article series, we describe our approach to managing CVJ pathologies in a case-based fashion to illustrate key concepts.

Chemoprophylactic Anticoagulation Following Lumbar Surgery Significantly Reduces Thromboembolic Events After Instrumented Fusions, Not Decompressions.

STUDY DESIGN: Retrospective cohort. OBJECTIVE: To quantify any reduction in venous thromboembolic events (VTEs) caused by chemoprophylaxis among lumbar surgery patients. SUMMARY OF BACKGROUND DATA: Chemoprophylactic anticoagulation (chemoprophylaxis) is used to prevent VTE after lumbar surgery. However, the treatment effect of chemoprophylaxis has not been reported among spine surgery patients, as conventional statistical methods preclude such inferences. MATERIALS AND METHODS: A total of 1243 consecutive lumbar fusions and 1433 noninstrumented lumbar decompressions performed at our institution over a six-year period were identified, and clinical and demographic data were collected, including on VTE events within 30 days postoperatively. Instrumented lumbar fusions and noninstrumented lumbar surgeries were analyzed separately. Patients who were given chemoprophylaxis (treatment) and controls were matched according to known VTE risk factors, including age, body mass index, sex, diabetes, chronic kidney disease, history of VTE, estimated blood loss, length of surgery, transfusion, whether surgery was staged, and whether surgery used an anterior approach. K-nearest neighbor propensity score matching was performed, and the treatment effect of chemoprophylaxis was calculated. RESULTS: Unadjusted, there was no difference in the rate of VTE between treatment and controls in either population. Baseline clinical and demographic characteristics differed significantly between treatment and control groups. In all, 575 lumbar fusion patients and 435 noninstrumented lumbar decompression patients were successfully propensity score matched, yielding balanced models (Rubin B <25, 0.560% reduction in known bias for both populations. The treatment effect of chemoprophylaxis after lumbar fusion in our patient population was a reduction in VTE incidence from 9.4% to 4.2% ( P <0.05), and propensity score adjusted regression confirmed a reduced odds of VTE with chemoprophylaxis (odds ratio=0.37, P =0.035). The treatment effect was not significant for noninstrumented lumbar decompression patients. CONCLUSION: Among patients undergoing instrumented lumbar fusions, chemoprophylactic anticoagulation causes a significant reduction in VTE, but causes no significant reduction among patients undergoing noninstrumented lumbar decompression.

Neurologic, functional, and survival outcomes following surgical management of metastatic breast cancer to the spine.

OBJECTIVE: Metastatic spinal tumors commonly arise from primary breast cancer. We assessed outcomes and identified associated variables for patients who underwent surgical management for spinal metastases of breast cancer. METHODS: We retrospectively reviewed patients surgically treated for spinal metastases of breast cancer. Neurologic and functional outcomes were analyzed via Frankel scale and Karnofksy Performance Status (KPS) scores, respectively. Variables associated with Frankel and KPS scores after surgery were identified. Multivariable analysis was used to assess predictors for postoperative survival. RESULTS: Forty-nine patients were identified. There was no significant difference in Frankel scores postoperatively and at last follow-up. KPS scores (P = 0.002) significantly improved at last follow-up. Preoperative non-ambulation and postprocedural complications were associated with non-ambulation postoperatively. Postprocedural complications and disease-free interval (DFI) < 24 and < 60 months were associated with functional impairment at last follow-up. Current smoking status at the time of surgery (P = 0.021) and triple negative (negative immunohistochemistry for estrogen receptor, progesterone receptor, and HER2) breast cancer (P = 0.038) were significantly associated with shortened postoperative survival. CONCLUSION: When indicated, surgery for spinal metastases of breast cancer leads to preservation of neurologic status and long-term functional improvement. Preoperative ambulatory status and postprocedural complications were associated with ambulatory status after surgery, while postprocedural complications and shortened DFI were associated with functional status after surgery.Current smoking status at the time of surgery and triple negative breast cancer are negative predictors for postoperative survival after metastatic breast cancer to the spine.

Surgical Site Infection, Readmission, and Reoperation After Posterior Long Segment Fusion.

STUDY DESIGN: Retrospective case series. OBJECTIVE: We sought to identify risk factors associated with surgical site infection (SSI) after posterior long segment spinal fusion (PLSF). SUMMARY OF BACKGROUND DATA: Patients who undergo PLSF may be at elevated risk of SSI. Identifying factors associated with SSI in these operations can help risk stratify patients and tailor management. METHODS: We analyzed PLSFs-seven or more levels-at our institution from 2000 to 2015. Data on patients' clinical characteristics, procedural factors, and antimicrobial management were collected. Multivariable analysis identified factors independently associated with outcomes of interest. RESULTS: In 628 cases, SSI was associated with steroid use (P = 0.024, odds ratio [OR] = 2.54) and using cefazolin (P < 0.001, OR = 4.37) or bacitracin (P = 0.010, OR 3.49) irrigation, as opposed to gentamicin or other irrigation. Gram-positive infections were more likely with staged procedures (P = 0.021, OR 4.91) and bacitracin irrigation (P < 0.001, OR = 17.98), and less likely with vancomycin powder (P = 0.050, OR 0.20). Gram-negative infections were more likely with a history of peripheral arterial disease (P = 0.034, OR = 3.21) or cefazolin irrigation (P < 0.001, OR 25.47). Readmission was more likely after staged procedures (P = 0.003, OR = 3.31), cervical spine surgery (P = 0.023, OR = 2.28), or cefazolin irrigation (P = 0.039, OR = 1.85). Reoperation was more common with more comorbidities (P = 0.022, OR 1.09), staged procedures (P < 0.001, OR = 4.72), cervical surgeries (P = 0.013, OR = 2.36), more participants in the surgery (P = 0.011, OR = 1.06), using cefazolin (P < 0.001, OR = 3.12) or bacitracin (P = 0.009, OR = 3.15) irrigation, and higher erythrocyte sedimentation rate at readmission (P = 0.009, OR = 1.04). Washouts were more likely among patients with more comorbidities (P = 0.013, OR = 1.16), or who used steroids (P = 0.022, OR = 2.92), and less likely after cervical surgery (P = 0.028, OR = 0.24). Instrumentation removal was more common with bacitracin irrigation (p = 0.013, OR = 31.76). CONCLUSION: Patient factors, whether a procedure is staged, and choice of antibiotic irrigation affect the risk of SSI and ensuing management required.Level of Evidence: 4.

Impact of Resident Participation During Surgery on Neurosurgical Outcomes: A Meta-Analysis.

BACKGROUND: There has been much attention recently on whether the involvement of neurosurgical residents during surgery impacts patient outcomes. Our goal was to perform a meta-analysis of all existing studies in order to determine the true effect of resident involvement. METHODS: We performed a systematic review and identified studies that compared resident involvement during surgery to attending neurosurgeons alone. Event rates and adjusted odds ratios were collected and pooled to generate estimates. RESULTS: Eleven studies were identified, of which 9 reported adjusted odds ratios. Meta-analysis showed that there were no significant differences in patient baseline characteristics (age, gender, the majority of medical comorbidities). Analysis of operative variables showed increases in a number of complications. However, adjustment of odds ratios for confounders eliminated most of these effects but continued to show a mild increase in overall complications with an odds ratio of 1.14 (P = 0.02). Notably, for both adjusted and unadjusted estimates, no significant differences were seen in 30-day mortality. CONCLUSIONS: We found that, when adjusted for comorbidities, complexity, and procedure type, there was no difference in outcomes in terms of surgical complications, reoperation, length of stay more than 5 days, and mortality. While these results suggest that our apprenticeship teaching model is safe for developing independent physicians, using new educational modalities such as simulation and resident-directed labs may be useful to attenuate potential patient complications in higher-risk procedures and in patients with comorbidities.

Comparison of inpatient versus post-discharge venous thromboembolic events after spinal surgery: A single institution series of 6869 consecutive patients.

STUDY DESIGN: retrospective chart review. OBJECTIVE: We aimed to determine the perioperative risk factors that lead to inpatient or post-discharge venous thromboembolism (VTE) events after spinal surgery. SUMMARY OF BACKGROUND DATA: While many studies relate the risk factors in a post-surgical setting to the incidence of VTE, this study aims to separate these VTE into inpatient and post-discharge categories to examine timing and risk factors. METHODS: We analyzed 6869 patients from 2009 to 2015 using Current Procedural Technology codes from a single tertiary academic institution. Patients were stratified based on occurrence and setting of VTE then controlled for perioperative characteristics with exclusion criteria being patients undergoing minor spine surgeries or secondary procedures. RESULTS: In 170 VTE events, these factors were associated with increased risk for: Inpatient DVT only: IVC filter (OR 6.380 [3.414-11.924]), longer length of hospital stay (OR 1.083 [1.047-1.120]), a prior history of DVT (OR 3.640 [1.931-6.856]). Post-discharge DVT only: history of PE (OR 45.142 [6.785-300.351]), having a corpectomy (OR 26.670 [3.477-204.548]), and having an osteotomy (OR 18.877 [1.129-315.534]). Inpatient PE only: surgery >4 h (OR 30.820, p < 0.001), fracture (OR 6.913, p = 0.004), IVC filter (OR 3.135, p = 0.029). Post-discharge PE only: corpectomy (OR 541.271, p = 0.009), foraminotomy (OR 40.137, p = 0.013), EBL > 500cc (OR 2467.798, p = 0.002). Time to onset of VTE events was significantly longer for patients undergoing osteotomy (7.43 days) than for patients with fracture (4.28 days), which is consistent with our findings that fracture was an independent predictor of inpatient VTE, and osteotomy was an independent predictor of post-discharge VTE (p = 0.018). CONCLUSIONS: Time-to-VTE varies between types of surgeries. Some risk factors are independently associated with VTE at all times during the 30-day postoperative period, while other factors are only associated with either inpatient or post-discharge VTE. Those patients with high-risk features for post-discharge VTE merit increased study for thromboprophylaxis management.

Impact of CrossFit-Related Spinal Injuries.

INTRODUCTION: Exercise-related injuries (ERIs) are a common cause of nonfatal emergency department and hospital visits. CrossFit is a high-intensity workout regimen whose popularity has grown rapidly. However, ERIs due to CrossFit remained under investigated. METHODS: All patients who presented to the main hospital at a major academic center complaining of an injury sustained performing CrossFit between June 2010 and June 2016 were identified. Injuries were classified by anatomical location (eg, knee, spine). For patients with spinal injuries, data were collected including age, sex, body mass index (BMI), CrossFit experience level, symptom duration, type of symptoms, type of clinic presentation, cause of injury, objective neurological examination findings, imaging type, number of clinic visits, and treatments prescribed. RESULTS: Four hundred ninety-eight patients with 523 CrossFit-related injuries were identified. Spine injuries were the most common injuries identified, accounting for 20.9%. Among spine injuries, the most common location of injury was the lumbar spine (83.1%). Average symptom duration was 6.4 months ± 15.1, and radicular complaints were the most common symptom (53%). A total of 30 (32%) patients had positive findings on neurologic examination. Six patients (6.7%) required surgical intervention for treatment after failing an average of 9.66 months of conservative treatment. There was no difference in age, sex, BMI, or duration of symptoms of patients requiring surgery with those who did not. CONCLUSIONS: CrossFit is a popular, high-intensity style workout with the potential to injure its participants. Spine injuries were the most common type of injury observed and frequently required surgical intervention.

Venous thromboembolism events following spinal fractures: A single center experience.

OBJECTIVE: Venous thromboembolic events (VTE), including deep venous thrombosis (DVT) and pulmonary embolism (PE), are a major cause of readmission, morbidity, and mortality after spine surgery. Patients with spinal fractures are particularly at an increased risk for VTE. The objective of this study is to understand VTE risk factors in this patient population and to examine current institutional practices. PATIENTS AND METHODS: We retrospectively examined records from 195 consecutive patients with spinal fractures who underwent spinal stabilization surgeries- amongst a cohort of 6869 patients who underwent spinal surgery. We collected data on patient demographics, surgery, hospital course, and 30-day rates of VTE, readmission, reoperation. Multivariable logistic regression was used to identify independent predictors of each outcome. RESULTS: Among 195 patients undergoing surgery for spinal fractures, 9.2% experienced a VTE, compared to 2.3% among all other spine patients (OR 4.466, p < 0.0001). 48.7% spine fracture patients received chemoprophylactic anticoagulation, compared to 35.7% of all other spine patients (OR 2.657, p < 0.0001). Within 30 days of surgery, estimated blood loss (EBL) was associated with VTE (OR 1.001, p = 0.0415) and DVT (OR 1.001, p = 0.049), and comorbid cardiac disease burden showed a trend toward significance in predicting both VTE (OR 1.890, p = 0.0956) and DVT (OR 4.228, p = 0.0549). Number of levels in surgery predicted PE within 30 days of surgery (OR 1.573, p = 0.0107). CONCLUSIONS: Compared to all other patients undergoing spine surgery, patients with spinal fractures are more likely to receive chemoprophylactic anticoagulation, but nevertheless have a higher rate of VTE events. EBL and comorbid disease burden predict VTE events in patients with spine fractures.

Impact of resident participation on outcomes following lumbar fusion: An analysis of 5655 patients from the ACS-NSQIP database.

The role of resident involvement on patient safety, morbidity, and mortality in lumbar spinal surgery has been poorly defined in the literature. The objective of this study is to investigate the relationship between resident involvement in the operating room and 30-day complication rates in patients undergoing lumbar spinal fusion procedures. We used the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database to retrospectively identify all patients who underwent a lumbar spinal fusion from 2006 to 2013. A propensity score matching algorithm was employed to minimize baseline differences. Multivariate logistic regression analysis of unadjusted and propensity-matched groups was performed to examine the effect of resident participation on operative details and 30-day complication rates. A total of 5655 patients met the inclusion criteria and propensity score matching yielded 1965 well-matched pairs. Resident involvement in lumbar fusion procedures was not found to be a significant predictor for mortality or reoperation. It was found to be a significant predictor for increased hospital stay (matched non-resident 4.0 ±â€¯5.8 days vs. resident 4.6 ±â€¯4.3 days, p < 0.001), operative time (matched non-resident 198 ±â€¯102 min vs. resident 243 ±â€¯118 min, p < 0.001), sepsis (matched OR 4.36, 95% CI 2.10-9.05, p < 0.001), development of DVT/PE (matched OR 2.02, 95% CI 1.10-3.70, p = 0.023), and superficial surgical site infections (matched OR 1.78, 95% CI 1.04-3.06, p = 0.037). In conclusion, this large-scale, population-based study found that resident participation in the operating room was safe but increased the risk of 30-day complications and increased operative duration and length of hospital stay.

The Role of Minimally Invasive Techniques in Scoliosis Correction Surgery.

OBJECTIVE: Recently, minimally invasive surgery (MIS) has been included among the treatment modalities for scoliosis. However, literature comparing MIS to open surgery for scoliosis correction is limited. The objective of this study was to compare outcomes for scoliosis correction patients undergoing MIS versus open approach. METHODS: We retrospectively collected data on demographics, procedure characteristics, and outcomes for 207 consecutive scoliosis correction surgeries at our institution between 2009 and 2015. RESULTS: MIS patients had lower number of levels fused (p < 0.0001), shorter surgeries (p = 0.0023), and shorter overall lengths of stay (p < 0.0001), were less likely to be admitted to the ICU (p < 0.0001), and had shorter ICU stays (p = 0.0015). On multivariable regression, number of levels fused predicted selection for MIS procedure (p = 0.004), and multiple other variables showed trends toward significance. Age predicted ICU admission and VTE. BMI predicted any VTE, and DVT specifically. Comorbid disease burden predicted readmission, need for transfusion, and ICU admission. Number of levels fused predicted prolonged surgery, need for transfusion, and ICU admission. CONCLUSIONS: Patients undergoing MIS correction had shorter surgeries, shorter lengths of stay, and shorter and fewer ICU stays, but there was a significant selection effect. Accounting for other variables, MIS did not independently predict any of the outcomes.

The timing of venous thromboembolic events after spine surgery: a single-center experience with 6869 consecutive patients.

OBJECTIVE Venous thromboembolic events (VTEs), including both deep venous thrombosis (DVT) and pulmonary embolism, are a major cause of morbidity and mortality after spine surgery. Prophylactic anticoagulation, or chemoprophylaxis, can prevent VTE. However, the timing of VTEs after spine surgery and the effect of chemoprophylaxis on VTE timing remain underinvestigated. METHODS The records of 6869 consecutive spine surgeries were retrospectively examined. Data on patient demographics, surgical variables, hospital course, and timing of VTEs were collected. Patients who received chemoprophylaxis were compared with those who did not. Appropriate regression models were used to examine selection for chemoprophylaxis and the timing of VTEs. RESULTS Age (OR 1.037, 95% CI 1.023-1.051; p < 0.001), longer surgery (OR 1.003, 95% CI 1.002-1.004; p < 0.001), history of DVT (OR 1.697, 95% CI 1.038-2.776; p = 0.035), and fusion surgery (OR 1.917, 95% CI 1.356-2.709; p < 0.001) predicted selection for chemoprophylaxis. Chemoprophylaxis patients experienced more VTEs (3.62% vs 2.03% of patients, respectively; p < 0.001), and also required longer hospital stays (5.0 days vs 1.0 days; HR 0.5107; p < 0.0001) and had a greater time to the occurrence of VTE (median 6.8 days vs 3.6 days; HR 0.6847; p = 0.0003). The cumulative incidence of VTEs correlated with the postoperative day in both groups (Spearman r = 0.9746, 95% CI 0.9457-0.9883, and p < 0.0001 for the chemoprophylaxis group; Spearman r = 0.9061, 95% CI 0.8065-0.9557, and p < 0.0001 for the nonchemoprophylaxis group), and the cumulative incidence of VTEs was higher in the nonchemoprophylaxis group throughout the 30-day postoperative period. Cumulative VTE incidence and postoperative day were linearly correlated in the first 2 postoperative weeks (R = 0.9396 and p < 0.0001 for the chemoprophylaxis group; R = 0.8190 and p = 0.0003 for the nonchemoprophylaxis group) and the remainder of the 30-day postoperative period (R = 0.9535 and p < 0.0001 for the chemoprophylaxis group; R = 0.6562 and p = 0.0058 for the nonchemoprophylaxis group), but the linear relationships differ between these 2 postoperative periods (p < 0.0001 for both groups). CONCLUSIONS Anticoagulation reduces the cumulative incidence of VTE after spine surgery. The cumulative incidence of VTEs rises linearly in the first 2 postoperative weeks and then plateaus. Surgeons should consider early initiation of chemoprophylaxis for patients undergoing spine surgery.

The Effect of Steroids on Complications, Readmission, and Reoperation After Posterior Lumbar Fusion.

BACKGROUND: The effects of chronic corticosteroid therapy on complications, readmission, and reoperation after posterior lumbar fusion (PLF) remain underinvestigated, and were examined to determine differences in outcomes. METHODS: We analyzed patients undergoing PLF between 2006 and 2013 using the National Surgery Quality Improvement Program database (NSQIP). Patients taking steroids for a chronic condition were compared with those not taking steroids. Multivariable regression identified factors independently associated with complications, readmission, and reoperation. A risk score was calculated for predicting complications. RESULTS: A total of 8492 patients were identified, of whom 353 used steroids. The patients using steroids were older (mean age, 65.4 years vs. 61.0 years; P < 0.001), were more likely to be female (61.2% vs. 55.1%; P = 0.025), had a higher American Society of Anesthesiologists class (P < 0.001), were less likely to be functionally independent (90.3% vs. 96.5%; P < 0.001), and were more likely to have a history of hypertension (69.1% vs. 58.3%; P < 0.001), diabetes mellitus (21.8% vs. 17.4%; P = 0.033), cardiac disease (74.8% vs. 66.1%; P = 0.001), and/or severe chronic obstructive pulmonary disease (10.5% vs. 4.2%; P < 0.001). The rates of readmission (9.4% vs. 6.0%; P = 0.023), reoperation (6.5% vs. 3.6%; P = 0.004), overall complications (14.5% vs. 9.6%; P = 0.003), and infections (9.6% vs. 5.1%; P < 0.001) were higher in the steroid group. On multivariable regression, steroids were independently associated with overall complications (odds ratio [OR], 1.38; P = 0.044) and infectious complications (OR, 1.65; P < 0.001), but not with medical complications, readmission, or reoperation. Patients with higher risk scores had higher complication rates. CONCLUSIONS: The use of corticosteroid therapy is associated with a moderately increased risk of overall complications, but no association was found with readmission or reoperation.

Defining Glioblastoma Resectability Through the Wisdom of the Crowd: A Proof-of-Principle Study.

BACKGROUND: Extent of resection (EOR) correlates with glioblastoma outcomes. Resectability and EOR depend on anatomical, clinical, and surgeon factors. Resectability likely influences outcome in and of itself, but an accurate measurement of resectability remains elusive. An understanding of resectability and the factors that influence it may provide a means to control a confounder in clinical trials and provide reference for decision making. OBJECTIVE: To provide proof of concept of the use of the collective wisdom of experienced brain tumor surgeons in assessing glioblastoma resectability. METHODS: We surveyed 13 academic tumor neurosurgeons nationwide to assess the resectability of newly diagnosed glioblastoma. Participants reviewed 20 cases, including digital imaging and communications in medicine-formatted pre- and postoperative magnetic resonance images and clinical vignettes. The selected cases involved a variety of anatomical locations and a range of EOR. Participants were asked about surgical goal, eg, gross total resection, subtotal resection (STR), or biopsy, and rationale for their decision. We calculated a "resectability index" for each lesion by pooling responses from all 13 surgeons. RESULTS: Neurosurgeons' individual surgical goals varied significantly ( P = .015), but the resectability index calculated from the surgeons' pooled responses was strongly correlated with the percentage of contrast-enhancing residual tumor ( R = 0.817, P < .001). The collective STR goal predicted intraoperative decision of intentional STR documented on operative notes ( P < .01) and nonresectable residual ( P < .01), but not resectable residual. CONCLUSION: In this pilot study, we demonstrate the feasibility of measuring the resectability of glioblastoma through crowdsourcing. This tool could be used to quantify resectability, a potential confounder in neuro-oncology clinical trials.

The Safety of Surgery in Elderly Patients with Primary and Recurrent Glioblastoma.

BACKGROUND: Glioblastoma (GBM) occurs more commonly in elderly patients. However, these patients are often excluded from clinical trials. The absence of solid evidence has resulted in a nihilistic view of GBM in the elderly and a traditionally conservative treatment approach. In particular, the safety of surgical resection for both primary and recurrent GBM is poorly understood in elderly patients. METHODS: In a retrospective cohort of patients aged ≥65 years, we examined selection for biopsy, surgical resection, and reoperation for recurrent disease. We also analyzed complication rates after initial resection and reoperation for recurrent disease. We identified 319 elderly patients with pathologically proven GBM who underwent a total of 274 craniotomies at our institution between 2000 and 2012. Events were reported according to the methods used in the Glioma Outcomes Project. RESULTS: The overall rate of complications after resection was 21.9%, with a rate of neurological complications of 7.7%. The rates of neurological, regional, and systemic complications were not significantly different after initial craniotomy and reoperation for GBM in elderly patients. Reoperations were not associated with an increased risk of complications. Low cardiovascular risk, improved functional status, and hemispheric GBM were associated with selection for more aggressive surgical treatment. Younger age and improved functional status were associated with a reduced likelihood of complications. CONCLUSIONS: We conclude that in select patients, age alone should not preclude the decision to pursue aggressive surgical management.