Clinical presentation and extent of resection impacts progression-free survival in spinal ependymomas

PURPOSE

Primary treatment of spinal ependymomas involves surgical resection, however recurrence ranges between 50 and 70%. While the association of survival outcomes with lesion extent of resection (EOR) has been studied, existing analyses are limited by small samples and archaic data resulting in an inhomogeneous population. We investigated the relationship between EOR and survival outcomes, chiefly overall survival (OS) and progression-free survival (PFS), in a large contemporary cohort of spinal ependymoma patients.

METHODS

Adult patients diagnosed with a spinal ependymoma from 2006 to 2021 were identified from an institutional registry. Patients undergoing primary surgical resection at our institution, ≥ 1 routine follow-up MRI, and pathologic diagnosis of ependymoma were included. Records were reviewed for demographic information, EOR, lesion characteristics, and pre-/post-operative neurologic symptoms. EOR was divided into 2 classifications: gross total resection (GTR) and subtotal resection (STR). Log-rank test was used to compare OS and PFS between patient groups.

RESULTS

Sixty-nine patients satisfied inclusion criteria, with 79.7% benefitting from GTR. The population was 56.2% male with average age of 45.7 years, and median follow-up duration of 58 months. Cox multivariate model demonstrated significant improvement in PFS when a GTR was attained (p <.001). Independently ambulatory patients prior to surgery had superior PFS (p <.001) and OS (p =.05). In univariate analyses, patients with a syrinx had improved PFS (p =.03) and were more likely to benefit from GTR (p =.01). Alternatively, OS was not affected by EOR (p =.78).

CONCLUSIONS

In this large, contemporary series of adult spinal ependymoma patients, we demonstrated improvements in PFS when GTR was achieved.

The obesity paradox and ventriculoperitoneal shunting in aneurysmal subarachnoid hemorrhage patients undergoing microsurgical clipping

BACKGROUND

Aneurysmal subarachnoid hemorrhage (aSAH) can be devastating. Identifying predisposing factors is paramount in reducing aSAH-related mortality. Obesity's negative impact on health is well-established. However, the controversial "obesity paradox" in neurosurgery suggests that obesity may confer a survival advantage in SAH. We hypothesized that obesity would have a negative impact on outcomes following surgical clipping in aSAH.

METHODS

A single-institution retrospective review was performed of aSAH patients undergoing surgical clipping from 2017 to 2021. Demographics and clinically relevant variables were collected. Obesity was defined as body mass index >30. Primary outcome was death or severe disability (mRS 4-6) at last follow-up. Secondary outcome was VPS placement. Multivariable Cox proportional-hazards model identified predictors of poor outcome. Kaplan-Meier curves identified survivorship differences between obese and non-obese patients.

RESULTS

Poor outcome occurred in 11 of 52 total patients (21.2 %). There were no differences in demographics or distribution of Hunt Hess (HH), modified Fisher Grade (mFG), or external ventricular drain (EVD) placement between obese and non-obese patients. On univariate analysis, hypertension, older age, and non-obesity were predictive of poor outcome. On multivariable analysis, only obesity remained significant, suggesting a protective effect from poor outcome (HR 0.45 [0.21-0.95], p = 0.037). VPS placement occurred in 6 (11.5 %) patients for which obesity was not a significant predictor.

CONCLUSIONS

Obesity may have a protective effect against poor outcome following surgical clipping in aSAH. Additionally, obesity does not appear to increase rate of EVD conversion to VPS. Thus, our study suggests that obesity should not preclude patients from open surgical intervention when clinically appropriate.

Repeat Flow Diversion for Retreatment of Incompletely Occluded Large Complex Symptomatic Cerebral Aneurysms: A Retrospective Case Series

BACKGROUND AND OBJECTIVES

Data regarding radiographic occlusion rates after repeat flow diversion after initial placement of a flow diverter (FD) in large intracranial aneurysms are limited. We report clinical and angiographic outcomes on 7 patients who required retreatment with overlapping FDs after initial flow diversion for large intracranial aneurysms.

METHODS

We performed a retrospective review of a prospectively maintained database of cerebrovascular procedures performed at our institution from 2017 to 2021. We identified patients who underwent retreatment with overlapping FDs for large (>10 mm) cerebral aneurysms after initial flow diversion. At last angiographic follow-up, occlusion grade was evaluated using the O'Kelly-Marotta (OKM) grading scale.

RESULTS

Seven patients (median age 57 years) with cerebral aneurysms requiring retreatment were identified. The most common aneurysm location was the ophthalmic internal carotid artery (n = 3) and basilar trunk (n = 3). There were 4 fusiform and 3 saccular aneurysms. The median aneurysm width was 18 mm; the median neck size for saccular aneurysms was 7 mm; and the median dome-to-neck ratio was 2.8. The median time to retreatment was 9 months, usually due to symptomatic mass effect. After retreatment, the median clinical follow-up was 36 months, MRI/magnetic resonance angiography follow-up was 15 months, and digital subtraction angiography follow-up was 14 months. Aneurysm occlusion at last angiographic follow-up was graded as OKM A (total filling, n = 1), B (subtotal filling, n = 2), C (early neck remnant, n = 3), and D (no filling, n = 0). All patients with symptomatic improvement were OKM C, whereas patients with worsened symptom burden were OKM A or B. Two patients required further open surgical management for definitive management of the aneurysm remnant.

CONCLUSION

Although most patients demonstrated a decrease in aneurysm remnant size, many had high-grade persistent filling (OKM grades A or B) in this subset of mostly large fusiform aneurysms. Larger studies with longer follow-up are warranted to optimize treatment strategies for atypical aneurysm remnants after repeat flow diversion.

Standardized Interview Scoring Methodology for Neurosurgical Residency Applicant Selection

Interviews are critical to the neurosurgery resident application process. The COVID-19 pandemic forced residency interview activities are conducted virtually. To maintain a degree of control during a period of uncertainty, our department implemented a standardized survey for interviewers to evaluate the noncognitive attributes and program compatibility of applicants. Our objective was to assess the reliability and biases associated with our standardized interviewer survey implemented in neurosurgical residency interviews. A 5-question interviewer survey to assess applicant interview performance and program compatibility was implemented during the 2020 to 2021 interview season. After the application cycle, survey metrics were retrospectively reviewed. Multiple cohort analyses were performed by dividing interviewers into cohorts based on status (faculty or resident) and sex. Applicant scores were assessed within sex subgroups for each aforementioned interviewer cohort. Intraclass correlation coefficients (ICCs) were calculated to assess survey reliability. Fifteen interviewers (8 faculty and 7 residents) and 35 applicants were included. Female applicants (17%) and interviewers (20%) comprised the minority. There were no differences between resident and faculty reviewer scores; however, female reviewers gave higher overall scores than male reviewers ( P = .003). There was no difference in total scores between female and male applicants when evaluating all reviewers or subgroups of faculty, residents, females, or males. ICC analysis demonstrated good (ICC 0.75-0.90) or excellent (ICC > 0.90) reliability for all questions and overall score. The standardized interviewer survey was a feasible and reliable method for evaluating noncognitive attributes during neurosurgery residency interviews. There was no perceptible evidence of sex bias in our single-program experience.

A Biomechanical Assessment of Shaken Baby Syndrome: What About the Spine?

BACKGROUND

Shaken baby syndrome occurs following inertial loading of the pediatric head, resulting in retinal hemorrhaging, subdural hematoma, and encephalopathy. However, the anatomically vulnerable cervical spine receives little attention. Automotive safety literature is replete with biomechanical data involving forward-facing pediatric surrogates in frontal collisions, an environment analogous to shaking. Publicly available data involving child occupants were utilized to study pediatric neck and head injury potential. We hypothesized that inertial loading provides a greater risk of injury to the cervical spine than to the head.

METHODS

Full-scale automotive crash tests (n = 131) and deceleration sled tests (n = 32) utilizing forward-facing 3-year-old surrogates with head accelerometers and cervical force sensors were analyzed. One hundred sixty-seven full-scale vehicle and 33 sled test runs were assessed in the context of published injury assessment reference values (IARVs) for closed head injury (head injury criterion 15 [HIC₁₅]) and cervical tensile strength in the 3-year-old model.

RESULTS

One hundred sixty-one (96%) child surrogates in full-scale crash tests exceeded the cervical peak tension IARV, while only 37 (22%) surpassed the HIC₁₅ IARV. Similarly, in sled testing runs, 27 (82%) pediatric surrogates exceeded cervical tension IARVs, while 1 (3%) surpassed the HIC₁₅ IARV. In both full-scale and sled tests, all surrogates surpassing the HIC₁₅ IARV also exceeded the cervical tension IARV. Positive linear correlations were observed between HIC₁₅ and cervical tensile forces in both full-scale vehicle (R² = 0.15) and sled testing runs (R² = 0.54).

CONCLUSIONS

These data support the hypothesis that inertial loading of the head provides a greater injury risk to the cervical spine than to closed-head injury.

An Assessment of Nonoperative Management Strategies in a Herniated Lumbar Disc Population: Successes Versus Failures

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To compare the utilization of conservative treatments in patients with lumbar intervertebral disc herniations who were successfully managed nonoperatively versus patients who failed conservative therapies and elected to undergo surgery (microdiscectomy).

METHODS

Clinical records from adult patients with an initial herniated lumbar disc between 2007 and 2017 were selected from a large insurance database. Patients were divided into 2 cohorts: patients treated successfully with nonoperative therapies and patients that failed conservative management and opted for microdiscectomy surgery. Nonoperative treatments utilized by the 2 groups were collected over a 2-year surveillance window. "Utilization" was defined by cost billed to patients, prescriptions written, and number of units disbursed.

RESULTS

A total of 277 941 patients with lumbar intervertebral disc herniations were included. Of these, 269 713 (97.0%) were successfully managed with nonoperative treatments, while 8228 (3.0%) failed maximal nonoperative therapy (MNT) and underwent a lumbar microdiscectomy. MNT failures occurred more frequently in males (3.7%), and patients with a history of lumbar epidural steroid injections (4.5%) or preoperative opioid use (3.6%). In a logistic multivariate regression analysis, male sex and utilization of opioids were independent predictors of conservative management failure. Furthermore, a cost analysis indicated that patients who failed nonoperative treatments billed for nearly double ($1718/patient) compared to patients who were successfully treated ($906/patient).

CONCLUSION

Our results suggest that the majority of patients are successfully managed nonoperatively. However, in the subset of patients that fail conservative management, male sex and prior opioid use appear to be independent predictors of treatment failure.

Comparison of Postoperative Opioid Utilization in an ACDF Cohort: Narcotic Naive Patients Versus Preoperative Opioid Users

STUDY DESIGN

A retrospective cohort study.

OBJECTIVE

To compare the postoperative opioid utilization rates and costs after anterior cervical discectomy and fusion (ACDF) procedures between groups of patients who were preoperative opioid users versus opioid naive.

SUMMARY OF BACKGROUND DATA

Opioid medications are frequently prescribed after ACDF procedures. Given the current opioid epidemic, there is increased emphasis on early identification of patients at risk for prolonged postoperative opioid use.

METHODS

Records from patients diagnosed with cervical stenosis who underwent a ≤3-level index ACDF surgery between 2007 and 2017 were collected from a large insurance database. International Classification of Diseases diagnosis/procedure codes, Current Procedural Terminology codes, and generic drug codes were used to search clinical records. Two cohorts were established: a group of patients who utilized opioids preoperatively and a group of patients who were opioid naive at the time of surgery. The 1-year utilization and costs of postoperative therapies were documented for each group.

RESULTS

The preoperative opioid use cohort contained 4485 patients (61.6%), whereas the opioid-naive cohort included 2799 patients (38.4%). Postoperatively, 86.6% of the preoperative opioid use group continued to use opioids, whereas 59.0% of the opioid-naive group began using opioids. Patients who utilized opioids preoperatively were 4.48 times more likely (95% confidence interval, 3.99-5.02, P<0.001) to use opioids postoperatively and 4.30 times more likely (95% confidence interval, 3.10-5.94, P<0.001) to become opioid dependent compared with opioid-naive patients. In addition, after normalization, patients in the preoperative opioid use group utilized 3.7 times more opioid units/patient and billed for 5.3 times more dollars/patient than opioid-naive patients.

CONCLUSIONS

In patients with cervical stenosis who undergo an ACDF procedure, the postoperative utilization and costs of opioids seem to be substantially higher in patients with preoperative opioid use compared with opioid-naive patients. Efforts should be made to avoid opioid use as a component of conservative management before surgery.

LEVEL OF EVIDENCE

Level III.

A comparison of successful versus failed nonoperative treatment approaches in patients with degenerative conditions of the lumbar spine

Identifying an optimal composition of nonoperative therapies to trial in patients suffering from degenerative lumbar spine conditions prior to surgical management remains challenging. Contrasting successful versus failed nonoperative treatment approaches may provide clinicians with valuable insight. The purpose of this study was to compare the nonoperative therapy regimens in degenerative lumbar spine disorder patients successfully managed conservatively versus patients who failed primary treatment and opted for lumbar fusion surgery. Clinical records from patients diagnosed with lumbar stenosis or spondylolisthesis from 2007 to 2017 were gathered from a comprehensive insurance database. Patients were separated into two cohorts: patients managed successfully with nonoperative therapies and patients who failed conservative therapy and underwent lumbar fusion surgery. Nonoperative therapy utilization by the two cohortswere collected across a 2-year surveillance window. A total of 531,980 adult patients with lumbar stenosis or spondylolisthesis comprised the base population. There were 523,031 patients (98.3%) successfully treated with conservative management alone, while 8,949 patients (1.7%) ultimately failed nonoperative management and opted for lumbar fusion.Conservative therapy failure rates were especially high in patients with a smoking history (2.1%) and those utilizing lumbar epidural steroid injections (LESIs) (3.7%). A greater percentage of patients who failed conservative management utilized opioid medications (p < 0.0001), muscle relaxants (p < 0.0001), and LESIs (p < 0.0001). Patients who failed nonoperative management spent more than double than the successfully treated cohort (failed cohort: $1806.49 per patient; successful cohort: $768.50 per patient). In a multivariate logistic regression model, smoking, obesity and prolonged opioid use were independently associated with failure of nonoperative treatment.

Extent of resection and survival outcomes in World Health Organization grade II meningiomas

PURPOSE

WHO grade II meningiomas behave aggressively, with recurrence rates as high as 60%. Although complete resection in low-grade meningiomas is associated with a relatively low recurrence rate, the impact of complete resection for WHO grade II meningiomas is less clear. We studied the association of extent of resection with overall and progression-free survivals in patients with WHO grade II meningiomas.

METHODS

A retrospective database review was performed to identify all patients who underwent surgical resection for intracranial WHO grade II meningiomas at our institution between 1995 and 2019. Kaplan-Meier analysis was used to compare overall and progression-free survivals between patients who underwent gross total resection (GTR) and those who underwent subtotal resection (STR). Multivariable Cox proportional-hazards analysis was used to identify independent predictors of tumor recurrence and mortality.

RESULTS

Of 214 patients who underwent surgical resection for WHO grade II meningiomas (median follow-up 53.4 months), 158 had GTR and 56 had STR. In Kaplan-Meier analysis, patients who underwent GTR had significantly longer progression-free (p = 0.002) and overall (p = 0.006) survivals than those who underwent STR. In multivariable Cox proportional-hazards analysis, GTR independently predicted prolonged progression-free (HR 0.57, p = 0.038) and overall (HR 0.44, p = 0.017) survivals when controlling for age, tumor location, and adjuvant radiation.

CONCLUSIONS

Extent of resection independently predicts progression-free and overall survivals in patients with WHO grade II meningiomas. In an era of increasing support for adjuvant treatment modalities in the management of meningiomas, our data support maximal safe resection as the primary goal in treatment of these patients.

Regional differences in prolonged non-operative therapy utilization prior to primary ACDF surgery

There is a paucity of data characterizing regional variations in the utilization and costs of conservative management in patients suffering from cervical stenosis prior to anterior cervical discectomy and fusion (ACDF) surgery. An understating of these regional trends becomes critical as outcomes-based reimbursement strategies become standard. The objective of this investigation was to evaluate for regional differences in the utilization and overall costs of maximal non-operative therapy (MNT) prior to ACDF surgery. Medical records from patients with symptomatic cervical stenosis undergoing a ≤3-level index ACDF procedure between 2007 and 2016 were accessed from a large insurance database. Geographic regions (Midwest, Northeast, South, and West) reflected U.S. Census Bureau definitions. MNT utilization within 2-years prior to ACDF surgery was analyzed. An index ACDF surgery was performed in 15,825 patients. Patient regional breakdown was as follows: South (67.6% of patients), Midwest (21.8% of patients), West (8.9% of patients), Northeast (1.6% of patients). Regional variations were identified in the number of patients utilizing NSAIDs (p < 0.001), opioids (p < 0.001), muscle relaxants (p < 0.001), cervical epidural steroid injections (p = 0.001), physical therapy/occupational therapy treatments (p < 0.001), and chiropractor visits (p < 0.001). The West (64.5%) and South (63.5%) had the greatest proportion of patients utilizing narcotics. When normalized by the number of opioid using-patients however, the Northeast (691.4 pills/patient) and South (674.4 pills/patient) billed for the most opioid pills. The total direct cost associated with all MNT prior to index ACDF was $17,255,828. The Midwest ($1,277.72 per patient) and South ($1,047.86 per patient) had the greatest average dollars billed.

A comparison of prolonged nonoperative management strategies in cervical stenosis patients: Successes versus failures

A paucity of evidence exists regarding the optimal composition of conservative therapies to best treat patients diagnosed with cervical stenosis prior to consideration of surgery. The purpose of this study was to compare the nonoperative therapy utilization strategies in cervical stenosis patients successfully managed with conservative treatments versus those that failed medical management and opted for an anterior cervical discectomy and fusion (ACDF) surgery. Medical records from adult patients with a diagnosis of cervical stenosis from 2007 to 2017 were collected retrospectively from a large insurance database. Patients were divided into two cohorts: patients treated successfully with nonoperative therapies and patients that failed conservative management and opted for ACDF surgery. Nonoperative therapies utilized by the two cohorts were collected over a 2-year surveillance window. A total of 90,037 adult patients with cervical stenosis comprised the base population. There were 83,384 patients (92.6%) successfully treated with nonoperative therapies alone, while 6,653 patients (7.4%) ultimately failed conservative management and received an ACDF. Failure rates of non-operative therapies were higher in smokers (11.2%), patients receiving cervical epidural steroid injections (11.2%), and male patients (8.1%). A greater percentage of patients who failed conservative management utilized opioid medications (p < 0.001), muscle relaxants (p < 0.001), and CESIs (p < 0.001). The costs of treating patients that failed conservative management was double the amount of the successfully treated group (failed cohort: $1,215.73 per patient; successful cohort: $659.58 per patient). A logistic regression analysis demonstrated that male patients, smokers, opioid utilization, and obesity were independent predictors of conservative treatment failure.

Gender differences in use of prolonged non-operative therapies prior to index ACDF surgery

Prior to anterior cervical discectomy and fusion (ACDF) surgery, patients suffering from cervical stenosis traditionally trial non-operative treatments for pain management. There is a paucity of data evaluating gender disparities in the prolonged utilization of conservative therapy prior to ACDF surgery. Therefore, the purpose of this study was to assess for gender-based differences in the utilization and cost of maximal non-operative therapy (MNT) for cervical stenosis prior to ACDF surgery. Medical records from patients with symptomatic cervical stenosis undergoing 1, 2, or 3-level index ACDF procedures between 2007 and 2016 were gathered from an insurance database consisting of 20.9 million covered lives. The utilization of MNTs within 5 years prior to index ACDF surgery was assessed. A total of 2254 patients (females: 53.1%) underwent an index ACDF surgery. There were a significantly greater percentage of female patients that utilized NSAIDs (p < 0.0001), opioids (p = 0.0019), muscle relaxants (p < 0.0001), cervical epidural steroid injections (p = 0.0428), and physical therapy/occupational therapy treatments (p < 0.0001). The total direct cost associated with all MNT prior to index ACDF was $4,833,384. On average, $2028.01 was spent per male patient while $2247.29 was spent per female patient. When normalized by number of pills billed per patient utilizing therapy, female patients utilized more NSAIDs (males: 591.8 pills, females: 669.3 pills), opioids (male: 1342.0 pills, female: 1650.1 pills), and muscle relaxants (males: 823.7 pills, females: 1211.1 pills). The results suggest that there may be gender differences in the utilization of non-operative therapies for symptomatic cervical stenosis prior to ACDF surgery.

Racial Differences in Perioperative Opioid Utilization in Lumbar Decompression and Fusion Surgery for Symptomatic Lumbar Stenosis or Spondylolisthesis

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

To assess for racial differences in opioid utilization prior to and after lumbar fusion surgery for patients with lumbar stenosis or spondylolisthesis.

METHODS

Clinical records from patients with lumbar stenosis or spondylolisthesis undergoing primary <3-level lumbar fusion from 2007 to 2016 were gathered from a comprehensive insurance database. Records were queried by International Classification of Diseases diagnosis/procedure codes and insurance-specific generic drug codes. Opioid use 6 months prior, through 2 years after surgery was assessed. Multivariate regression analysis was employed to investigate independent predictors of opioid use following lumbar fusion.

RESULTS

A total of 13 257 patients underwent <3-level posterior lumbar fusion. The cohort racial distribution was as follows: 80.9% white, 7.0% black, 1.0% Hispanic, 0.2% Asian, 0.2% North American Native, 0.8% "Other," and 9.8% "Unknown." Overall, 57.8% patients utilized opioid medications prior to index surgery. When normalized by the number opiate users, all racial cohort saw a reduction in pills disbursed and dollars billed following surgery. Preoperatively, Hispanics had the largest average pills dispensed (222.8 pills/patient) and highest average amount billed ($74.67/patient) for opioid medications. The black cohort had the greatest proportion of patients utilizing preoperative opioids (61.8%), postoperative opioids (87.1%), and long-term opioid utilization (72.7%), defined as use >1 year after index operation. Multivariate logistic regression analysis indicated Asian patients (OR 0.422, 95% CI 0.191-0.991) were less likely to use opioids following lumbar fusion.

CONCLUSIONS

Racial differences exist in perioperative opioid utilization for patients undergoing lumbar fusion surgery for spinal stenosis or spondylolisthesis. Future studies are needed corroborate our findings.

Regional Variation in Nonoperative Therapy Utilization for Symptomatic Lumbar Stenosis and Spondylolisthesis: A 2-Year Costs Analysis

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

To characterize regional variations in maximal nonoperative therapy (MNT) costs in patients suffering from lumbar stenosis or spondylolisthesis.

METHODS

Medical records from patients with symptomatic lumbar stenosis or spondylolisthesis undergoing primary ≤3-level lumbar decompression and fusion procedures from 2007 to 2016 were gathered from a large insurance database. Geographic regions (Midwest, Northeast, South, and West) reflected the US Census Bureau definitions. Records were searchable by International Classification of Diseases diagnosis/procedure codes, Current Procedural Terminology codes, and insurance-specific generic drug codes. Utilization of MNT, defined as cost billed, prescriptions written, and number of units disbursed, within 2-years prior to index surgery was assessed.

RESULTS

A total of 27 877 patients underwent 1-, 2-, or 3-level lumbar decompression and fusion surgery. Regional breakdown of the study cohort was as follows: South 62.3%, Midwest 25.2%, West 10.4%, Northeast 2.1%. Regional variations in the number of patients using nonsteroidal anti-inflammatory drugs (NSAIDs) (P < .0001), opioids (P < .0001), muscle relaxants (P < .0001), and lumbar steroid injections (P < .0001) were detected. A significant difference was identified in the regional MNT failure rates (P < .0001). The total cost associated with MNT prior to index surgery was $48 411 125 ($1736.60/patient), with the Midwest ($1943.83/patient) responsible for the greatest average spending. Despite comprising 62.3% of the cohort, the South was accountable for 67.5% of NSAID prescriptions, 64.6% of opioid prescriptions, and 71.2% of muscle relaxant prescriptions.

CONCLUSIONS

Regional differences exist in the costs of MNT in patients with lumbar stenosis and spondylolisthesis prior to surgery. Future studies should focus on identifying patients likely to fail prolonged nonoperative management.

Heart dose and coronary artery calcification in patients receiving thoracic irradiation for lung cancer

Background

Thoracic irradiation (TIR) is associated with an increased risk of coronary artery disease (CAD) and coronary-related death. Lung cancer patients receive considerable doses of TIR, making them a high-risk population that may benefit from post-therapy surveillance. Coronary artery calcium (CAC) is a known biomarker of CAD development and may serve as a useful indicator of disease progression in this population. We hypothesized greater CAC progression in lung cancer patients subjected to higher whole heart radiation doses.

Methods

CAC progression (pre- and >2 years post-TIR) from chest CT scans of lung cancer patients were evaluated. A 2:1 matched control population was established controlling for age, gender, race, and CT scan interval. Vessel-specific CAC presence, progression, and extension in pre- and post-interval CT studies was evaluated by two blinded reviewers using the ordinal method. Dosimetric treatment files were restored and contours of the whole heart and proximal left anterior descending artery (LAD) were created within existing plans to compute radiation doses (Pinnacle Treatment Planning Software). Binary logistic regression analysis identified factors predictive for CAC development. Multiple logistic regression analysis with hierarchal method was used to assess covariates.

Results

Thirty-five patients and 65 controls (50% female) were evaluated; mean age 57 years, mean follow-up post-radiation 4.9±2.2 years. Average mean and maximum left anterior descending coronary artery (LAD) radiation doses were 19.9 Gy (95% CI, 14.1–25.7) and 30.7 Gy (95% CI, 23.8–37.5), respectively; 91.6% inter-observer variability. There was greater incidence of coronary calcification in irradiated patients (48.6% vs. 24.6%; P=0.01). In interval CT scans, a greater proportion of radiated patients demonstrated new coronary calcification (P=0.007) and extension within the LAD (P=0.003). Radiation exposure was the only independent predictor of new calcification (OR 3.1; 95% CI: 1.09–9.2).

Conclusions

We identified both an increase in the development and progression of CAC in lung cancer patients receiving TIR. Future studies utilizing alternative cancer populations and larger sample sizes are necessary to further correlate radiographic and dosimetric observations to cardiovascular events.

Reduction in Narcotic Use After Lumbar Decompression and Fusion in Patients With Symptomatic Lumbar Stenosis or Spondylolisthesis

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

The purpose of this study is to assess change in opioid use before and after lumbar decompression and fusion surgery for patients with symptomatic lumbar stenosis or spondylolisthesis.

METHODS

A large insurance database was queried for patients with symptomatic lumbar stenosis or spondylolisthesis undergoing index lumbar decompression and fusion procedures between 2007 and 2016. This database consists of 20.9 million covered lives and includes private/commercially insured and Medicare Advantage beneficiaries. Opioid use 6 months preoperatively through 2 years postoperatively was assessed.

RESULTS

The study included 13 257 patients that underwent 1-, 2-, or 3-level posterior lumbar instrumented fusion. Overall, 57.8% of patients used opioids preoperatively. Throughout the 6-month preoperative period, 2 368 008 opioid pills were billed for (51.6 opioid pills/opioid user/month). When compared with preoperative opioid use, patients billed fewer opioid medications in the 2-year period postoperatively: 33.6 pills/patient/month (8 851 616 total pills). In a multivariate logistic regression analysis, obesity (odds ratio [OR] 1.10, 95% CI 1.004-1.212), preoperative narcotic use (OR 3.43, 95% CI 3.179-3.708), length of hospital stay (OR 1.02, 95% CI 1.010-1.021), and receiving treatment in the South (OR 1.18, 95% CI 1.074-1.287) or West (OR 1.26, 95% CI 1.095-1.452) were independently associated with prolonged postoperative (>1 year) opioid use. Additionally, males (OR 0.87, 95% CI 0.808-0.945) were less likely to use long-term opioid therapy.

CONCLUSIONS

This study demonstrates that reduction in opioid use was observed postoperatively in comparison with preoperative values in patients with symptomatic lumbar stenosis or spondylolisthesis that underwent lumbar decompression with fusion. Further prospective studies that are more methodologically stringent are needed to corroborate our findings.

A 2-Year Cost Analysis of Maximum Nonoperative Treatments in Patients With Symptomatic Lumbar Stenosis or Spondylolisthesis That Ultimately Required Surgery

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

The purpose of this study is to characterize the utilization and costs of maximal nonoperative therapies (MNTs) within 2 years prior to spinal fusion surgery in patients with symptomatic lumbar stenosis or spondylolisthesis.

METHODS

A large insurance database was queried for patients with symptomatic lumbar stenosis or spondylolisthesis undergoing index 1-, 2-, or 3-level lumbar decompression and fusion procedures between 2007 and 2016. This database consists of 20.9 million covered lives and includes private/commercially insured and Medicare Advantage beneficiaries. The utilization of MNTs within 2 years prior to index surgery was assessed by cost billed to the patient, prescriptions written, and number of units billed.

RESULTS

A total of 27 877 out of 3 423 114 (0.8%) eligible patients underwent posterior lumbar instrumented fusion. Patient MNT utilization was as follows: 11 383 (40.8%) used nonsteroidal anti-inflammatory drugs (NSAIDs), 19 770 (70.9%) used opioids, 12 414 (44.5%) used muscle relaxants, 14 422 (51.7%) received lumbar epidural steroid injection (LESI), 11 156 (40.0%) attended physical therapy/occupational therapy, 4005 (14.4%) presented to the emergency department, and 4042 (14.5%) received chiropractor treatments. The total direct cost associated with all MNTs prior to index spinal fusion was $28 241 320 ($1013.07 per/patient). LESI comprised the largest portion of the total cost of MNT ($15 296 941, 54.2%), followed by opioids ($3 702 463, 13.1%) and NSAIDs ($3 058 335, 10.8%).

CONCLUSIONS

Opioids are the most frequently prescribed and most used therapy in the preoperative period. Assuming minimal improvement in pain and functional disability after maximum nonoperative therapies, the incremental cost effectiveness ratio for MNT could be highly unfavorable.

A Two-Year Cost Analysis of Maximum Nonoperative Treatments in Patients with Cervical Stenosis that Ultimately Required Surgery

OBJECTIVE

The aim of this study is to characterize the use and associated costs of maximal nonoperative therapy (MNT) received within 2-years before anterior cervical discectomy and fusion (ACDF) surgery in patients with symptomatic cervical stenosis.

METHODS

An insurance database, including private/commercially insured and Medicare Advantage beneficiaries, was queried for patients undergoing 1-level, 2-level, or 3-level ACDF procedures between 2007 and 2016. Research records were searchable by International Classification of Diseases diagnosis and procedure, Current Procedural Terminology, and generic drug codes. The use of MNTs within 2 years before index ACDF surgery was assessed by cost billed to patients, prescriptions written, and number of units billed.

RESULTS

Of 220,902 (7.16%) eligible patients, 15,825 underwent index surgery. Patient breakdown of the use of MNT modalities was as follows: 5731 (36.2%) used nonsteroidal antiinflammatory drugs; 9827 (62.1%) used opioids; 7383 (46.7%) used muscle relaxants; 3609 (22.8%) received cervical epidural steroid injection; 5504 (34.8%) attended physical therapy/occupational therapy; 1663 (10.5%) received chiropractor treatments; and 200 (1.3%) presented to the emergency department. During the 2-year preoperative period, there were 51,675 prescriptions for diagnostic cervical imaging. The total direct cost associated with all MNTs before ACDF was $16,056,556. Cervical spine imaging comprised the largest portion of the total MNT cost ($8,677,110; 54.0%), followed by cervical epidural steroid injection ($3,315,913; 20.7%) and opioids ($2,228,221; 13.9%). Opiates were the most frequently prescribed therapy (71,602 prescriptions).

DISCUSSION

Opioids are the most frequently prescribed and most used therapy in the preoperative period for cervical stenosis. Further studies and improved guidelines are necessary to determine which patients may benefit from ACDF earlier in the course of nonoperative therapies.

Gender Differences in Use of Prolonged Nonoperative Therapies Before Index Lumbar Surgery

OBJECTIVE

The purpose of the present study was to assess for gender-based differences in the usage and cost of maximal nonoperative therapy before spinal fusion surgery in patients with symptomatic lumbar stenosis or spondylolisthesis.

METHODS

A large insurance database was queried for patients with symptomatic lumbar stenosis or spondylolisthesis undergoing index lumbar decompression and fusion procedures from 2007 to 2016. This database consists of 20.9 million covered lives and includes private or commercially insured and Medicare Advantage beneficiaries. Only patients continuously active within the Humana insurance system for ≥5 years before the index operation were eligible. Usage was characterized by the cost billed to the patient, prescriptions written, and number of units billed.

RESULTS

A total of 4133 patients (58.5% women) underwent 1-, 2-, or 3-level posterior lumbar instrumented fusion. A significantly greater percentage of female patients used nonsteroidal anti-inflammatory drugs (P < 0.0001), lumbar epidural steroid injections (P = 0.0044), physical and/or occupational therapy (P < 0.0001), and muscle relaxants (P < 0.0001). The total direct cost associated with all maximal nonoperative therapy before index spinal fusion was $9,000,968, with men spending $3,451,479 ($2011.35 per patient) and women spending $5,549,489 ($2296.02 per patient). When considering the quantity of units billed, women used 61.5% of the medical therapy units disbursed despite constituting 58.5% of the cohort. When normalized by the number of pills billed per patient using therapy, female patients used more nonsteroidal anti-inflammatory drugs, opioids, and muscle relaxants.

CONCLUSIONS

These results suggest that gender differences exist in the use of nonoperative therapies for symptomatic lumbar stenosis or spondylolisthesis before fusion surgery.

Hemolysis following wrap aortoplasty for Type A aortic dissection repair: Case report and review of the literature

A Dacron wrap aortoplasty has been described as an adjunct to reduction ascending aortoplasty for the repair of Type A aortic dissections. We report a case of an uncomplicated hemiarch repair with wrap aortoplasty of the distal anastomosis which resulted in severe acute hemolysis. Despite only minimal focal graft deformation on imaging, the patient was found to have a flow gradient across the distal anastomosis, which was reduced by > 50% following release of the outer graft wrap. To our knowledge, only 29 additional cases of hemolytic anemia following aortic dissection repair have been described in the English literature. The reported mechanisms included aortic graft stenosis (50%), graft kinking (23%), external compression of the graft (20%), and a folded elephant trunk appendage (7%). The mean onset of hemolysis following aortic dissection repair occurred 32.2 ± 44.4 months after surgery, with only 16.7% of cases occurring within 2 weeks. This review details the clinical, laboratory, and imaging findings suggestive of mechanical hemolysis following aortic surgery.

Abstract 611: Association Between Thoracic Irradiation and Increased Progression of Coronary Artery Calcium

Introduction: Thoracic irradiation (TIR) is associated with increased risk of coronary artery disease (CAD) and coronary death. Coronary artery calcium (CAC) is the result of coronary plaque accumulation and has been shown to predict CAD and overall cardiovascular mortality. We hypothesized that TIR in lung cancer patients receiving radiotherapy would be associated with CAC progression.

Methods: We evaluated CAC progression (pre- and post-TIR) from chest CT scans of lung cancer patients identified from a cancer registry at an urban academic medical center. A 2:1 matched control population was established controlling for age, gender, race, and CT scan interval. Vessel-specific CAC progression and extension in pre- and post-interval CT studies was evaluated by 2 independent reviewers using existing standard methodologies. Whole heart and the left anterior descending (LAD) coronary artery were retrospectively segmented on the CT study used for treatment planning. The volume of each structure and associated dose metrics were obtained using the standard tools available in the Pinnacle Treatment Planning software. Chi squared tests were used to compare vessel-specific CAC progression (increase in CAC volume) and extension (CAC lengthening within a vessel) between groups. Pearson correlation analysis explored associations between radiation volume and CAC progression.

Results: We included 35 patients and 65 controls (50% female). Mean and max whole heart TIR doses: 13.5 Gy (95% CI 10.3-16.7 Gy) and 52.1 Gy (95% CI 46.2 – 58.0 Gy); LAD: 21.4 Gy (95% CI 16.0 – 26.8 Gy) and 34.9 Gy (95% CI 28.7 – 41.1 Gy), respectively. CAC progression and extension in LAD and left circumflex coronary artery (LCx) were significantly greater in patients vs. controls ( p <0.03 for all). There was statistically significant correlation between LAD radiation volume and CAC progression in the left main coronary artery (LM) (r =0.33, p =0.05).

Conclusions: TIR is associated with CAC progression in the LAD and LCx. For LAD and LM, the CAC progression correlated with the irradiated volume of these structures although neither a dose nor a volume threshold could be established. Future studies examining the utility of CAC screening for radiation-induced CAD and cardiovascular mortality are required.

Arterial diameter and the gender disparity in stroke thrombectomy outcomes

BACKGROUND

Compared with males, females consistently fare worse following mechanical thrombectomy for large vessel ischemic strokes. Understanding why this gender disparity occurs may guide improvements in future treatment strategies. In this study, we aim to determine whether gender differences in cerebral arterial diameter correlate with clinical outcomes following stroke thrombectomy.

METHODS

We performed an observational study of consecutive acute ischemic stroke patients undergoing mechanical thrombectomy at a single, urban tertiary care medical center. Catheter angiographic images were used to manually measure proximal segment arterial diameters in a standardized fashion. Medical record review was used to obtain relevant independent and dependent variables.

RESULTS

Ninety two patients (42 females) between June 2013 and August 2016 met inclusion criteria. Internal carotid artery (ICA) terminus diameters for males and females were 3.08 mm (SD=0.46) and 2.81 mm (SD=0.45), respectively (P=0.01). M1 segment middle cerebral artery (MCA) diameters for males and females were 2.47 mm (SD=0.30) and 2.18 mm (SD=0.31), respectively (P<0.0001). 48% of patients in the upper MCA caliber tertile attained a favorable mRS 90 day value compared with 35% in each of the lower and middle tertiles (P=0.51). Larger MCA diameters correlated with favorable discharge disposition (P=0.21).

CONCLUSIONS

These results provide limited evidence that males have larger cerebral arterial diameters than females and that larger arterial diameters may improve the odds for favorable clinical outcomes. If future studies validate these findings, arterial diameter may become a relevant variable in the design of improved thrombectomy strategies.

Abstract WP25: Gender Disparity in Mechanical Thrombectomy Outcomes: The Role of Arterial Caliber

Introduction: Despite level 1a evidence demonstrating the clinical benefit of mechanical thrombectomy in selected large vessel ischemic stroke patients, a gender disparity exists. Women not only have less favorable clinical outcomes after all stroke types, but the causes of this disparity remain elusive. Gender differences in cerebral vascular anatomy have been previously published. We hypothesize that differences in circle of Willis diameters may contribute to the gender disparity seen in clinical outcomes after mechanical thrombectomy for acute ischemic stroke.

Methods: Clinical and radiographic data from a consecutive series undergoing mechanical thrombectomy for anterior circulation large vessel ischemic strokes were reviewed. Measurements of the proximal middle cerebral artery (M1) segment and supraclinoid internal carotid artery (ICA) diameters were obtained in a standardized fashion from the thrombectomy procedure angiogram. All M1 measurements were recorded at 3 mm of the vessel origin while ICA measurements were taken 3 mm proximal to the ICA terminus. Covariates included age, occlusion location, vascular risk factors, admission NIHSS score and final TICI grade. Modified Rankin score (mRS) at 90 days was the dependent variable. Variable significance between male and female cohorts was determined using student T-Tests. Multivariate regression analysis was also performed.

Results: Ninety-four patients (41 female) between 6/2013 and 6/2016 fit the inclusion criteria. ICA terminus measurements for men and women were 3.07 mm (SD=0.46) and 2.88 mm (SD=0.47), respectively. M1 origin measurements for men and women were 2.46 mm (SD=0.31) and 2.21 mm (SD=0.37), respectively. Male ICA terminus and M1 origin measurements were larger than female (p = 0.05 and p < 0.001, respectively). 61% of men vs. 25% of women had 90-day mRS ≤ 2. Multivariate analysis indicated that only age was significantly associated with 90-day mRS ≤ 2.

Conclusions: Our single center series suggests that differences in intracranial vessel diameter may contribute to the gender disparity in outcomes after mechanical thrombectomy. Smaller circle of Willis arterial diameters may compromise collateral blood flow and increase the difficulty in achieving sufficient reperfusion.

Consistency and sealing of advanced bipolar tissue sealers

Objectives

The aim of this study was to evaluate two commonly used advanced bipolar devices (ENSEAL^® G2 Tissue Sealers and LigaSure™ Blunt Tip) for compression uniformity, vessel sealing strength, and consistency in bench-top analyses.

Methods

Compression analysis was performed with a foam pad/sensor apparatus inserted between closed jaws of the instruments. Average pressures (psi) were recorded across the entire inside surface of the jaws, and over the distal one-third of jaws. To test vessel sealing strength, ex vivo pig carotid arteries were sealed and transected and left and right (sealed) halves of vessels were subjected to burst pressure testing. The maximum bursting pressures of each half of vessels were averaged to obtain single data points for analysis. The absence or presence of tissue sticking to device jaws was noted for each transected vessel.

Results

Statistically higher average compression values were found for ENSEAL^® instruments (curved jaw and straight jaw) compared to LigaSure™, P<0.05. Moreover, the ENSEAL^® devices retained full compression at the distal end of jaws. Significantly higher and more consistent median burst pressures were noted for ENSEAL^® devices relative to LigaSure™ through 52 firings of each device (P<0.05). LigaSure™ showed a significant reduction in median burst pressure for the final three firings (cycles 50–52) versus the first three firings (cycles 1–3), P=0.027. Tissue sticking was noted for 1.39% and 13.3% of vessels transected with ENSEAL^® and LigaSure™, respectively.

Conclusion

In bench-top testing, ENSEAL^® G2 sealers produced more uniform compression, stronger and more consistent vessel sealing, and reduced tissue sticking relative to LigaSure™.

Rotational stiffness of American football shoes affects ankle biomechanics and injury severity

While previous studies have investigated the effect of shoe-surface interaction on injury risk, few studies have examined the effect of rotational stiffness of the shoe. The hypothesis of the current study was that ankles externally rotated to failure in shoes with low rotational stiffness would allow more talus eversion than those in shoes with a higher rotational stiffness, resulting in less severe injury. Twelve (six pairs) cadaver lower extremities were externally rotated to gross failure while positioned in 20 deg of pre-eversion and 20 deg of predorsiflexion by fixing the distal end of the foot, axially loading the proximal tibia, and internally rotating the tibia. One ankle in each pair was constrained by an American football shoe with a stiff upper, while the other was constrained by an American football shoe with a flexible upper. Experimental bone motions were input into specimen-specific computational models to examine levels of ligament elongation to help understand mechanisms of ankle joint failure. Ankles in flexible shoes allowed 6.7±2.4 deg of talus eversion during rotation, significantly greater than the 1.7±1.0 deg for ankles in stiff shoes (p = 0.01). The significantly greater eversion in flexible shoes was potentially due to a more natural response of the ankle during rotation, possibly affecting the injuries that were produced. All ankles failed by either medial ankle injury or syndesmotic injury, or a combination of both. Complex (more than one ligament or bone) injuries were noted in 4 of 6 ankles in stiff shoes and 1 of 6 ankles in flexible shoes. Ligament elongations from the computational model validated the experimental injury data. The current study suggested flexibility (or rotational stiffness) of the shoe may play an important role in both the severity of ankle injuries for athletes.

A rapid dietary screening device for clinics

A rapid dietary screening device was developed for use in clinics and tested for validity, reliability, and acceptability. Validity was tested using dietary information from 29 8-day weighed food diaries. For each diary, a score was derived by calculating a mean Nutrient Adequacy Ratio (NAR) for nine nutrients. Dietary information from each diary was also entered on the Dietary Intake Form (DIF). The relationship of the mean NAR and DIF scores had a positive correlation of 0.83. Reliability was determined by testing undergraduate students in a non-nutrition course twice, two weeks apart. Forty repeated paired food group and total dietary scores revealed positive correlations, with r = 0.81 for total dietary score, 0.91 for dairy products, 0.78 for protein, 0.80 for fruits and vegetables, and 0.88 for bread. Acceptability of DIF was measured by the time it took to fill out and evaluate it, as well as by the percentage of incomplete DIFs. The subjects included 135 women aged 12 to 50 years from three Northeastern Oklahoma Planned Parenthood clinics. The mean time to fill out and evaluate the DIF was 4 to 7 minutes. Seventy-nine percent of the individuals tested were able to complete the DIF. Dietary patterns could not be predicted in this population by age, income level, education level, race, or clinic site. The DIF provides a rapid, valid, reliable, and acceptable method of identifying the individual with a poor diet. Because it does not require the expertise of a nutritionist either for its completion or for its evaluation, this device permits the dietitian to allocate her/his time more effectively under time and cost limitations.

Effects of oral contraceptives on nutritional status

Major effects of oral contraceptives on nutritional status are elevation of triglycerides, decline in glucose tolerance, an apparent increase in the need for folate and vitamins C, B2 and B6, and a decrease in iron loss. Women at greater risk of nutritional deficits due to oral contraceptives include those who have just had a baby, are planning to have a baby later, already show nutritional deficiencies, have had recent illness or surgery, have poor dietary habits, are still growing or have a family history of diabetes or heart disease.

Epinephrine inhibition of the electrodermal response in the cat

Intravenous administration of epinephrine results in a dose-dependent inhibition of the peripherally evoked electrodermal response (EDR) in the cat. The magnitude of this depression of the EDR was greater when the responses were evoked by a single shock than by a train of shocks (10-12 Hz). The observation that this epinephrine-induced inhibition is antagonized by phentolamine suggests that an alpha-adrenergic mechanism is involved. It is unlikely that this effect is due primarily to the vascular actions of epinephrine because the inhibition of the EDR was much more prolonged than was the pressor action. Angiotensin was ineffective in inhibiting these responses.

Characteristics of the electrodermal response. A model for analysis of central sympathetic reactivity

Electrodermal responses (EDR) of the sympathetic-cholinergic sudomotor system were elicited in anaesthetized cats. Responses were evoked centrally from hypothalamic, medullary and spinal loci, by stimulation of the pre- and postganglionic peripheral nerves, and reflexly following stimulation of an afferent nerve. The response was found to be dependent upon innervation of both the median and ulnar nerves (approximately 40 and 60% respectively). Both the centrally and peripherally evoked responses were frequency-dependent when a maximal current was used. The EDR evoked peripherally or from the cervical cord reached its maximal amplitude at 10-16 Hz whereas the EDR evoked from the hypothalamus and medulla did not reach its maximal amplitude until 48-64 Hz. These responses are relatively independent of blood flow in that complete occlusion of the peripheral blood supply did not greatly alter the amplitude of centrally evoked responses. The results suggest that this sympathetic-cholinergic system may be a useful model system with which to study the actions of various adrenergic agents on the reactivity of central structures which regulate sympathetic nervous activity.

The electrodermal response as a model for central sympathetic reactivity: the action of clonidine

Electrodermal responses (EDR) were evoked centrally by stimulation of reactive loci in the posterior hypothalamus and peripherally by stimulation of the distal portion of the sectioned median or ulnar nerve. Moderate doses of clonidine (3-30 mug/kg, i.v.) reduced the amplitude of the centrally evoked EDR while having no effect on the peripherally evoked responses. This central action of clonidine occurred concomitantly with the clonidine-induced bradycardia and hypotension. Administration of clonidine shifted the centrally evoked EDR frequency-response curve to the right in a dose related manner at 3, 10 and 30 mu/kg, i.v. 1 mug/kg was without effect on these responses. This central depressant action of clonidine was partially reversed following administration of yohimbine (0.5-1.0 mug/kg, i.v.). These results suggest that clonidine inhibits central reactivity in this sympathetic-cholinergic system in a manner analogous to its action on other sympathetic systems, and that a central adrenergic inhibitory mechanism may be involved.

Brainstem loci for activation of electrodermal response in the cat

Brainstem loci from which electrodermal responses could be elicited were systematically explored by direct-stimulation techniques in chloralose-anesthetized and decerebrate cats. Reactive sites of the greatest amplitude were found to extend from the rostral border of the posterior hypothalamus, through the ventrolateral reticular formation of the pons and the medulla, to the cervical cord. Stimulation of these sites elicited stable, reproducible electrodermal responses of 10-30 mV in amplitude. In addition, it was found that stimulation of the ventrolateral extent of the lower brainstem evoked similar responses in the decerebrate preparation. Electrodermal responses could not be elicited from the dorsal medulla, the posterior commissure, or the midline region. The electrodermal response could be elicited from an apparently hypothalamus through the ventrolateral brainstem.