Surgical management of spinal metastases from primary thyroid carcinoma: Demographics, clinical characteristics, and treatment outcomes - A retrospective analysis.

Objective: Metastatic spinal tumors represent a rare but concerning complication of primary thyroid carcinoma. We identified demographics, metastatic features, outcomes, and treatment strategies for these tumors in our institutional cohort. Materials and Methods: We retrospectively reviewed patients surgically treated for spinal metastases of primary thyroid carcinoma. Demographics, tumor characteristics, and treatment modalities were collected. The functional outcomes were quantified using Nurik, Modified Rankin, and Karnofsky Scores. Results: Twelve patients were identified who underwent 17 surgeries for resection of spinal metastases. The primary thyroid tumor pathologies included papillary (4/12), follicular (6/12), and Hurthle cell (2/12) subtypes. The average number of spinal metastases was 2.5. Of the primary tumor subtypes, follicular tumors averaged 2.8 metastases at the highest and Hurthle cell tumors averaged 2.0 spinal metastases at the lowest. Five patients (41.7%) underwent preoperative embolization for their spinal metastases. Seven patients (58.3%) received postoperative radiation. There was no significant difference in progression-free survival between patients receiving surgery with adjuvant radiation and surgery alone (P = 0.0773). Five patients (41.7%) experienced postoperative complications. Two patients (16.7%) succumbed to disease progression and two patients (16.7%) experienced tumor recurrence following resection. Postsurgical mean Nurik scores decreased 0.54 points, mean Modified Rankin scores decreased 0.48 points, and mean Karnofsky scores increased 4.8 points. Conclusion: Surgery presents as an important treatment modality in the management of spinal metastases from thyroid cancer. Further work is needed to understand the predictive factors for survival and outcomes following treatment.

Reliability of a Novel Classification System for Thoracic Disc Herniations.

STUDY DESIGN: This is a cross-sectional survey. OBJECTIVE: The aim was to assess the reliability of a proposed novel classification system for thoracic disc herniations (TDHs). SUMMARY OF BACKGROUND DATA: TDHs are complex entities varying substantially in many factors, including size, location, and calcification. To date, no comprehensive system exists to categorize these lesions. METHODS: Our proposed system classifies 5 types of TDHs using anatomic and clinical characteristics, with subtypes for calcification. Type 0 herniations are small (≤40% of spinal canal) TDHs without significant spinal cord or nerve root effacement; type 1 are small and paracentral; type 2 are small and central; type 3 are giant (>40% of spinal canal) and paracentral; and type 4 are giant and central. Patients with types 1 to 4 TDHs have correlative clinical and radiographic evidence of spinal cord compression. Twenty-one US spine surgeons with substantial TDH experience rated 10 illustrative cases to determine the system's reliability. Interobserver and intraobserver reliability were determined using the Fleiss kappa coefficient. Surgeons were also surveyed to obtain consensus on surgical approaches for the various TDH types. RESULTS: High agreement was found for the classification system, with 80% (range 62% to 95%) overall agreement and high interrater and intrarater reliability (kappa 0.604 [moderate to substantial agreement] and kappa 0.630 [substantial agreement], respectively). All surgeons reported nonoperative management of type 0 TDHs. For type 1 TDHs, most respondents (71%) preferred posterior approaches. For type 2 TDHs, responses were roughly equivalent for anterolateral and posterior options. For types 3 and 4 TDHs, most respondents (72% and 68%, respectively) preferred anterolateral approaches. CONCLUSIONS: This novel classification system can be used to reliably categorize TDHs, standardize description, and potentially guide the selection of surgical approach. Validation of this system with regard to treatment and clinical outcomes represents a line of future study.

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.

Adolescent Idiopathic Scoliosis and Pregnancy.

Objective This study examined the interaction between adolescent idiopathic scoliosis (AIS) and pregnancy, focusing on pregnancy outcomes, changes in back pain, and anesthesia use. Methods A retrospective analysis was conducted on adult patients with AIS who gave birth at our institution between 2006 and 2022. Results A total of 163 AIS patients with 263 pregnancies were included. The median age at delivery was 33 (range 18 to 50) years. Among 157 patients with information on prior scoliosis treatment, 66.9% had not received treatment, 20.4% had undergone spinal fusion, and 12.7% had received bracing. Of the 260 pregnancies with available data, 90.4% were delivered at term and 8.5% were preterm. Of the 257 pregnancies with information on anesthesia type, 35.0% received epidural anesthesia, 17.9% received spinal anesthesia, 37.7% received combined spinal and epidural anesthesia, 8.2% received no anesthesia, and 1.2% received intravenous or general anesthesia. Difficulty administering neuraxial anesthesia was reported in 6.1% of cases, and these patients were less likely to receive combined spinal and epidural anesthesia (6.3% versus 39.8%, p = 0.0123). Among 116 cases with recorded back pain during pregnancy, 67.2% reported increased pain, 31.9% reported similar pain, and one patient reported decreased pain. Of the 16 patients with pre and postpartum radiographs, eight showed a Cobb angle increase ≥ 3°, with five patients having an increase ≥ 5°. Conclusions Pregnancy can exacerbate back pain and pose challenges for neuraxial anesthesia in some AIS patients. Further large-scale, multi-institutional studies with standardized data collection are needed to fully understand the impact of pregnancy on AIS.

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.

Outcome Reporting in Spine Surgery: A Review of Historical and Emerging Trends.

The general objectives of spine surgery are to alleviate pain, restore neurologic function, and prevent or treat spinal deformities or instability. The accumulating expanse of outcome measures has allowed us to more objectively quantify these variables and, therefore, gauge the success of treatments, ultimately improving the quality of the delivered health care. It has become increasingly evident that spinal conditions and their accompanying interventions affect all aspects of a patient's life, including their physical, mental, emotional, and social well-being. This underscores the challenge of creating clinically relevant and accurate outcome measures in spine care, and the reason why there is a growing recognition of the importance of subjective measures such as patient-reported outcome measures, that consider a patients' health-related quality of life. Subjective measures provide valuable insights into patient experiences and perceptions of treatment outcomes, whereas objective measures provide a reproducible glimpse into key radiographic and clinical parameters that are associated with a successful outcome. In this narrative review, we provide a detailed analysis of the most common subjective and objective outcome measures employed in spine surgery, with a special focus on their current role as well as the possible future of outcome reporting.

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.

Biological principles of adult degenerative scoliosis.

The global aging population has led to an increase in geriatric diseases, including adult degenerative scoliosis (ADS). ADS is a spinal deformity affecting adults, particularly females. It is characterized by asymmetric intervertebral disc and facet joint degeneration, leading to spinal imbalance that can result in severe pain and neurological deficits, thus significantly reducing the quality of life. Despite improved management, molecular mechanisms driving ADS remain unclear. Current literature primarily comprises epidemiological and clinical studies. Here, we investigate the molecular mechanisms underlying ADS, with a focus on angiogenesis, inflammation, extracellular matrix remodeling, osteoporosis, sarcopenia, and biomechanical stress. We discuss current limitations and challenges in the field and highlight potential translational applications that may arise with a better understanding of these mechanisms.

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.

Anterior approach lumbar fusions cause a marked increase in thromboembolic events: Causal inferences from a propensity-matched analysis of 1147 patients.

OBJECTIVE: Anterior lumbar fusions are thought to be associated with elevated venous thromboembolic event (VTE) rates, but the magnitude of this increase in VTE is not well described. The objective of this study was to quantify any increase in VTE caused by anterior approach lumbar fusion. METHODS: 1147 consecutive lumbar fusions performed at our institution over a six-year period were identified, and clinical and demographic data were collected. K-nearest neighbor propensity score matching and propensity score adjusted regression were performed. Patients undergoing anterior versus posterior approach lumbar fusions were matched according to age, body mass index, sex, VTE history, estimated blood loss, length of surgery, transfusion, selection for postoperative intensive care unit (ICU) admission, comorbid disease burden, and use of chemoprophylactic anticoagulation. RESULTS: Anterior approach surgery (OR=4.29, p < 0.001), a history of VTE (OR=8.67, p < 0.001), age (OR=1.53, p = 0.014), length of surgery (OR=1.16, p = 0.044), and selection for postoperative ICU admission (OR=4.60, p = 0.005) were independently associated with VTE on multivariable regression. 1058 anterior or posterior approach fusion patients were matched. After matching, overall bias was reduced by 71.0 %, no covariates remained significantly different between groups, and propensity scores were well balanced between populations (Rubin's B≤0.25, 0.5 ≤Rubin's R≤2.0). Significantly more patients in the anterior group underwent lower extremity duplex ultrasonography (LED) (36.9 % vs. 14.8 %, OR=3.36 [2.38, 4.76], p < 0.0001), and a statistically insignificantly higher proportion of LEDs were positive among patients in the anterior group (23.2 % vs. 13.2 %, OR=1.99 [0.92, 4.25], p = 0.108). After matching, the rate of VTE was 8.6 % for the anterior group and 1.3 % for the posterior group, with anterior approach surgery causing an increase in VTE by 7.2 % (95 % CI [2.28 %, 12.16 %], p = 0.004). CONCLUSION: Among patients undergoing lumbar fusions, anterior approach surgery causes an increase in VTE by 7.2%, which is a multifold increase in the proportion of patients with thromboembolic complications.

Surgical Site Infection in the Intensive Care Setting After Posterior Spinal Fusion: A Case Series Highlighting the Microbial Profile, Risk Factors, and the Importance of Comorbid Disease Burden.

BACKGROUND: Most posterior spinal fusion (PSF) patients do not require admission to an intensive care unit (ICU), and those who do may represent an underinvestigated, high-risk subpopulation. OBJECTIVE: To identify the microbial profile of and risk factors for surgical site infection (SSI) in PSF patients admitted to the ICU postoperatively. METHODS: We examined 3965 consecutive PSF patients treated at our institution between 2000 and 2015 and collected demographic, clinical, and procedural data. Comorbid disease burden was quantified using the Charlson Comorbidity Index (CCI). We performed multivariable logistic regression to identify risk factors for SSI, readmission, and reoperation. RESULTS: Anemia, more levels fused, cervical surgery, and cerebrospinal fluid leak were positively associated with ICU admission, and minimally invasive surgery was negatively associated. The median time to infection was equivalent for ICU patients and non-ICU patients, and microbial culture results were similar between groups. Higher CCI and undergoing a staged procedure were associated with readmission, reoperation, and SSI. When stratified by CCI into quintiles, SSI rates show a strong linear correlation with CCI ( P = .0171, R = 0.941), with a 3-fold higher odds of SSI in the highest risk group than the lowest (odds ratio = 3.15 [1.19, 8.07], P = .032). CONCLUSION: Procedural characteristics drive the decision to admit to the ICU postoperatively. Patients admitted to the ICU have higher rates of SSI but no difference in the timing of or microorganisms that lead to those infections. Comorbid disease burden drives SSI in this population, with a 3-fold greater odds of SSI for high-risk patients than low-risk patients.

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.

Operative versus nonoperative treatment for adult symptomatic lumbar scoliosis at 5-year follow-up: durability of outcomes and impact of treatment-related serious adverse events.

OBJECTIVE: Although short-term adult symptomatic lumbar scoliosis (ASLS) studies favor operative over nonoperative treatment, longer outcomes are critical for assessment of treatment durability, especially for operative treatment, because the majority of implant failures and nonunions present between 2 and 5 years after surgery. The objectives of this study were to assess the durability of treatment outcomes for operative versus nonoperative treatment of ASLS, to report the rates and types of associated serious adverse events (SAEs), and to determine the potential impact of treatment-related SAEs on outcomes. METHODS: The ASLS-1 (Adult Symptomatic Lumbar Scoliosis-1) trial is an NIH-sponsored multicenter prospective study to assess operative versus nonoperative ASLS treatment. Patients were 40-80 years of age and had ASLS (Cobb angle ≥ 30° and Oswestry Disability Index [ODI] ≥ 20 or Scoliosis Research Society [SRS]-22 subscore ≤ 4.0 in the Pain, Function, and/or Self-Image domains). Patients receiving operative and nonoperative treatment were compared using as-treated analysis, and the impact of related SAEs was assessed. Primary outcome measures were ODI and SRS-22. RESULTS: The 286 patients with ASLS (107 with nonoperative treatment, 179 with operative treatment) had 2-year and 5-year follow-up rates of 90% (n = 256) and 74% (n = 211), respectively. At 5 years, compared with patients treated nonoperatively, those who underwent surgery had greater improvement in ODI (mean difference -15.2 [95% CI -18.7 to -11.7]) and SRS-22 subscore (mean difference 0.63 [95% CI 0.48-0.78]) (p < 0.001), with treatment effects (TEs) exceeding the minimum detectable measurement difference (MDMD) for ODI (7) and SRS-22 subscore (0.4). TEs at 5 years remained as favorable as 2-year TEs (ODI -13.9, SRS-22 0.52). For patients in the operative group, the incidence rates of treatment-related SAEs during the first 2 years and 2-5 years after surgery were 22.38 and 8.17 per 100 person-years, respectively. At 5 years, patients in the operative group who had 1 treatment-related SAE still had significantly greater improvement, with TEs (ODI -12.2, SRS-22 0.53; p < 0.001) exceeding the MDMD. Twelve patients who received surgery and who had 2 or more treatment-related SAEs had greater improvement than nonsurgically treated patients based on ODI (TE -8.34, p = 0.017) and SRS-22 (TE 0.32, p = 0.029), but the SRS-22 TE did not exceed the MDMD. CONCLUSIONS: The significantly greater improvement of operative versus nonoperative treatment for ASLS at 2 years was durably maintained at the 5-year follow-up. Patients in the operative cohort with a treatment-related SAE still had greater improvement than patients in the nonoperative cohort. These findings have important implications for patient counseling and future cost-effectiveness assessments.

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.

Long-term outcomes of spinal ependymomas: an institutional experience of more than 60 cases.

PURPOSE: Spinal ependymomas represent the most common primary intramedullary tumors for which optimal management remains undefined. When possible, gross total resection (GTR) is often the mainstay of treatment, with consideration of radiotherapy (RT) in cases of residual or recurrent tumor. The impact of extent of resection and radiotherapy remain understudied. OBJECTIVE: Report on a large institutional cohort with lengthy follow-up to provide information on long-term outcomes and to contribute to limited data assessing the value of extent of resection and RT. METHODS: Patients with pathologically proven primary spinal ependymoma between 1990 and 2018 were identified. Kaplan-Meier estimates were used to calculate progression-free survival (PFS); local-control (LC) and overall survival (OS). Logistic regression was used to analyze variables' association with receipt of RT. RESULTS: We identified 69 patients with ependymoma of which 4 had leptomeningeal dissemination at diagnosis and were excluded. Of the remaining cohort (n = 65), 42 patients (65%) had Grade II spinal ependymoma, 20 (31%) had Grade I myxopapillary ependymoma and 3 (5%) had Grade III anaplastic ependymoma; 54% underwent GTR and 39% underwent RT. With a median follow-up of 5.7 years, GTR was associated with improved PFS. For grade II lesions, STR+RT yielded better outcomes than STR alone (10y PFS 77.1% vs 68.2%, LC 85.7% vs 50%). Degree of resection was the only significant predictor of adjuvant radiotherapy (p < 0.0001). CONCLUSION: Our findings confirm the importance of GTR in spinal ependymomas. Adjuvant RT should be utilized in the setting of a subtotal resection with expectation of improved disease-related outcomes.

Neuroanesthesia Guidelines for Optimizing Transcranial Motor Evoked Potential Neuromonitoring During Deformity and Complex Spinal Surgery: A Delphi Consensus Study.

STUDY DESIGN: Expert opinion-modified Delphi study. OBJECTIVE: We used a modified Delphi approach to obtain consensus among leading spinal deformity surgeons and their neuroanesthesiology teams regarding optimal practices for obtaining reliable motor evoked potential (MEP) signals. SUMMARY OF BACKGROUND DATA: Intraoperative neurophysiological monitoring of transcranial MEPs provides the best method for assessing spinal cord integrity during complex spinal surgeries. MEPs are affected by pharmacological and physiological parameters. It is the responsibility of the spine surgeon and neuroanesthesia team to understand how they can best maintain high-quality MEP signals throughout surgery. Nevertheless, varying approaches to neuroanesthesia are seen in clinical practice. METHODS: We identified 19 international expert spinal deformity treatment teams. A modified Delphi process with two rounds of surveying was performed. Greater than 50% agreement on the final statements was considered "agreement"; >75% agreement was considered "consensus." RESULTS: Anesthesia regimens and protocols were obtained from the expert centers. There was a large amount of variability among centers. Two rounds of consensus surveying were performed, and all centers participated in both rounds of surveying. Consensus was obtained for 12 of 15 statements, and majority agreement was obtained for two of the remaining statements. Total intravenous anesthesia was identified as the preferred method of maintenance, with few centers allowing for low mean alveolar concentration of inhaled anesthetic. Most centers advocated for <150 µg/kg/min of propofol with titration to the lowest dose that maintains appropriate anesthesia depth based on awareness monitoring. Use of adjuvant intravenous anesthetics, including ketamine, low-dose dexmedetomidine, and lidocaine, may help to reduce propofol requirements without negatively effecting MEP signals. CONCLUSION: Spine surgeons and neuroanesthesia teams should be familiar with methods for optimizing MEPs during deformity and complex spinal cases. Although variability in practices exists, there is consensus among international spinal deformity treatment centers regarding best practices. LEVEL OF EVIDENCE: 5.