Analysis of academic publishing output among 1634 successful applicants in the 2011-2018 neurosurgery residency match

BACKGROUND

Research productivity is a key criterion for applicant selection reported by residency program directors. Research volume reported on neurosurgery residency applications has risen steadily over the past decade.

OBJECTIVE

Perform retrospective bibliographic searches of successful applicants who matched into U.S. neurosurgery residency programs from 2011 to 2018, and assess the relationship between academic publishing and residency placement.

METHODS

Gender, MD/PhD status, U.S. News research ranking of medical school, and international medical graduate status (IMG) were determined for 1634 successful applicants from 2011 to 2018. Indexed publications before and after the start of residency were tabulated by Scopus®. Publication counts were stratified by first author, basic/clinical science, case reports, reviews, or other research. We then compared publishing trends across demographic variables and match cohorts.

RESULTS

Average pre-residency publications increased from 2.6 [1.7, 3.4] in 2011 to 6.5 [5.1, 7.9] in 2018. Men, PhD-holders, Top 20 and Top 40 U.S. medical school graduates, and IMGs had higher pre-residency publication counts overall. After stratifying by match cohort, however, there was no significant effect of gender on pre-residency publications. Applicants matching into residency programs with highly ranked affiliated hospitals had significantly higher pre-residency publications.

CONCLUSION

Publishing volume of successful neurosurgery applicants in the U.S. has risen recently and is associated with the stature of matched residency programs. Given the gap between verifiable and claimed research on residency applications, attention is needed to objectively evaluate research credentials in the selection process. The impending phase out of USMLE step 1 scores may increase emphasis on academic productivity.

Survival Outcomes After Intracranial Hemorrhage in Liver Disease

BACKGROUND

Survival outcomes for patients with liver disease who suffer an intracranial hemorrhage (ICH) have not been thoroughly investigated.

OBJECTIVE

To understand survival outcomes for 3 groups: (1) patients with an admission diagnosis of liver disease (end-stage liver disease [ESLD] or non-ESLD) who developed an ICH in the hospital, (2) patients with ESLD who undergo either operative vs nonoperative management, and (3) patients with ESLD on the liver transplant waitlist who developed an ICH in the hospital.

METHODS

We retrospectively reviewed hospital charts from March 2006 through February 2017 of patients with liver disease and an ICH evaluated by the neurosurgery service at a single academic medical center. The primary outcome was survival.

RESULTS

We included a total of 53 patients in this study. The overall survival for patients with an admission diagnosis of liver disease who developed an ICH (n = 29, 55%) in the hospital was 22%. Of those patients with an admission diagnosis of liver disease, 27 patients also had ESLD. Kaplan-Meier analysis found no significant difference in survival for ESLD patients (n = 33, 62%) according to operative status. There were 11 ESLD patients on the liver transplant waitlist. The overall survival for patients with ESLD on the liver transplant waitlist who suffered an in-hospital ICH (n = 7, 13%) was 14%.

CONCLUSION

ICH in the setting of liver disease carries a grave prognosis. Also, a survival advantage for surgical hematoma evacuation in ESLD patients is not clear.

Intratumor injection of CCL21-coupled vault nanoparticles is associated with reduction in tumor volume in an in vivo model of glioma

PURPOSE

Glioblastoma (GBM) is the most common and malignant primary adult brain tumor. Current care includes surgical resection, radiation, and chemotherapy. Recent clinical trials for GBM have demonstrated extended survival using interventions such as tumor vaccines or tumor-treating fields. However, prognosis generally remains poor, with expected survival of 20 months after randomization. Chemokine-based immunotherapy utilizing CCL21 locally recruits lymphocytes and dendritic cells to enhance host antitumor response. Here, we report a preliminary study utilizing CPZ-vault nanoparticles as a vehicle to package, protect, and steadily deliver therapy to optimize CCL21 therapy in a murine flank model of GBM.

METHODS

GL261 cells were subcutaneously injected into the left flank of eight-week-old female C57BL/6 mice. Mice were treated with intratumoral injections of either: (1) CCL21-packaged vault nanoparticles (CPZ-CCL21), (2) free recombinant CCL21 chemokine empty vault nanoparticles, (3) empty vault nanoparticles, or 4) PBS.

RESULTS

The results of this study showed that CCL21-packaged vault nanoparticle injections can decrease the tumor volume in vivo. Additionally, this study showed mice injected with CCL21-packaged vault nanoparticle had the smallest average tumor volume and remained the only treatment group with a negative percent change in tumor volume.

CONCLUSIONS

This preliminary study establishes vault nanoparticles as a feasible vehicle to increase drug delivery and immune response in a flank murine model of GBM. Future animal studies involving an intracranial orthotopic tumor model are required to fully evaluate the potential for CCL21-packaged vault nanoparticles as a strategy to bypass the blood brain barrier, enhance intracranial immune activity, and improve intracranial tumor control and survival.

Timing of adjuvant radiation therapy and survival outcomes after surgical resection of intracranial non-small cell lung cancer metastases

OBJECTIVE

To investigate if delay of adjuvant radiotherapy (ART) beyond 6 post-operative weeks affects survival outcomes in patients undergoing craniotomy or craniectomy for resection of non-small cell lung cancer (NSCLC) intracranial metastases.

PATIENTS AND METHODS

We performed a retrospective analysis of 28 patients undergoing resection of intracranial metastases and ART at our institution from 2001 to 2016. We assessed survival outcomes for patients who received delayed versus non-delayed ART, as well as associated risk factors.

RESULTS

Among 28 patients, 8 (29%) had delayed ART beyond 6 post-operative weeks. Fifteen received stereotactic radiotherapy (SRT), 8 (29%) received whole brain radiotherapy (WBRT), and 5 (18%) received combination WBRT + SRT. There were no significant differences in ART modality or dosing, age, sex, number of intracranial metastases, primary metastasis volume, rates of chemotherapy, extracranial metastases, or post-operative functional scores between groups. Expected post-operative survival was shorter with delayed ART (7 months versus 28 months, P = 0.01). The most common reason for delayed ART was complicated post-operative course (n = 3.38%). Significant risk factors for delayed ART included non-routine discharge (P = 0.01) and additional invasive procedures between surgery and ART start date (P = 0.02).

CONCLUSIONS

Our results suggest delayed ART in patients undergoing surgical resection of intracranial NSCLC metastases is associated with shorter overall survival. However, risk factors for delayed ART, including non-routine discharge and the need for additional invasive procedures, may have in themselves reflected poorer clinical courses that may have also contributed to the observed survival differences.

Clinical Assessment of Patients with Bilateral Superior Semicircular Canal Dehiscence

OBJECTIVE

Superior semicircular canal dehiscence (SSCD) is caused by a deformity in the arcuate eminence, leading to various vestibular and auditory symptoms that can manifest unilaterally or bilaterally. The aim of the present study was to distinguish the differences in symptoms, treatment options, and outcomes between patients with unilateral and bilateral SSCD.

METHODS

A retrospective medical record analysis was conducted to identify patients with SSCD treated at a tertiary care center from March 2011 to May 2017. The patient demographic data, preoperative symptom presentation, and postoperative outcomes were extracted. Statistical analyses were performed using IBM SPSS Statistics. Fisher's exact tests were computed to investigate the relationships between binary variables, with a significance level of P < 0.05.

RESULTS

A total of 99 patients with SSCD had been treated at our institution from March 2011 to May 2017. Of these 99 patients, 41 (41.4%) had a diagnosis of bilateral SSCD. Of the 41 patients with bilateral SSCD, 27 (65.9%) were women, and the mean age was 53.6 ± 10.9 years (range, 31.7-73.9). The most common presenting symptom was tinnitus (n = 33; 80.4%) and dizziness (n = 33; 80.4%). Previous trauma to the head correlated with a bilateral SSCD presentation (P = 0.04). Trends were reported between female sex and bilateral SSCD [r(35) = 0.32379; P = 0.0506]. Postoperatively, trends were also found, with greater rates of dizziness in patients with bilateral SSCD compared with those with unilateral SSCD (odds ratio, 3.81; P = 0.0659), and less improvement in dizziness (odds ratio, 0.186; P = 0.0627). No other significant differences were found between the symptoms or clinical outcomes and improvements between the bilateral and unilateral cohorts.

CONCLUSION

Bilateral SSCD might result in different clinical symptoms that are more prevalent compared with unilateral SSCD. The findings from the present series of patients with bilateral SSCD suggest that patient symptoms and history are important in the diagnosis of bilateral SSCD and deciding whether 1 or both dehiscences requires surgical intervention.

Novel Method of Measuring Canal Dehiscence and Evaluation of its Potential as a Predictor of Symptom Outcomes After Middle Fossa Craniotomy

BACKGROUND

Superior semicircular canal dehiscence (SSCD) is an osseous defect of the arcuate eminence of the petrous temporal bone. Strategies for measuring dehiscence size are variable, and the usefulness of such parameters remains in clinical equipoise.

OBJECTIVE

To present a novel method of measuring dehiscence volume and to evaluate its potential as a predictor of symptom outcomes after surgical repair of SSCD.

METHODS

High-resolution computed tomographic temporal bone images were imported into a freely available segmentation software. Dehiscence lengths and volumes were ascertained by independent authors. Inter-rater observer reliability was assessed using Cronbach's alpha. Correlation and regression analyses were performed to evaluate for relationships between dehiscence size and symptoms (pre- and post-operative).

RESULTS

Thirty-seven dehiscences were segmented using the novel volumetric assessment. Cronbach's alpha for dehiscence lengths and volumes were 0.97 and 0.95, respectively. Dehiscence lengths were more variable as compared to dehiscence volumes (σ2 8.92 vs σ2 0.55, F = 1.74). The mean dehiscence volume was 2.22 mm3 (0.74, 0.64-0.53 mm3). Dehiscence volume and headache at presentation were positively correlated (Rpb = 0.67, P = .03). Dehiscence volume and vertigo improvement after surgery were positively correlated, although this did not reach statistical significance (Rpb = 0.46, P = .21).

CONCLUSION

SSCD volumetry is a novel method of measuring dehiscence size that has excellent inter-rater reliability and is less variable compared to dehiscence length, but its potential as a predictor of symptom outcomes is not substantiated. However, the study is limited by low power.

A Method of Locating the Dehiscence during Middle Fossa Approach for Superior Semicircular Canal Dehiscence Surgery

Objectives  Superior semicircular canal dehiscence (SSCD) results from a defect in the middle cranial fossa floor. One challenge during SSCD repair is the lack of a consistent landmark. This study proposes a reference point above the external auditory canal at the level of the zygoma as the inferior craniectomy edge during surgery. Design  This is a retrospective review of patients with SSCD. Setting/Participants  A total of 72 cases of SSCD in 60 patients were repaired via a middle fossa approach at a single institution. Main Outcome Measures  The distance from the proposed reference point to the dehiscence was statistically analyzed using Shapiro-Wilk's goodness-of-fit test and Student's t -test. Results  Average distance for all patients was 28.84 ± 2.22 mm (range: 22.96-33.43). Average distance for females was 29.08 mm (range: 24.56-33.43) versus 28.26 mm (range: 22.96-32.36) for males. There was no difference in distance by sex ( p  = 0.174). The distance measurements followed a normal distribution with 95% of the patients between 24.49 and 33.10 mm. Conclusion  This study analyzed a potential reference point during a middle fossa approach for SSCD surgery. The distance from this reference point to the SSCD was found to be consistent and may serve as a readily identifiable landmark in localizing the dehiscence.

Insights into CCL21's roles in immunosurveillance and immunotherapy for gliomas

Chemokine (C-C) motif ligand 21 (CCL21) is involved in immunosurveillance and has recently garnered the attention of neuro-oncologists and neuroscientists. CCL21 contains an extended C-terminus, which increases binding to lymphatic glycosaminoglycans and provides a mechanism for cell trafficking by forming a stationary chemokine concentration gradient that allows cell migration via haptotaxis. CCL21 is expressed by endothelial cells of the blood-brain barrier in physiologic and pathologic conditions. CCL21 has also been implicated in leukocyte extravasation into the central nervous system. In this review, we summarize the role of CCL21 in immunosurveillance and explore its potential as an immunotherapeutic agent for the treatment of gliomas.

Central Neurocytoma: A Review of Clinical Management and Histopathologic Features

Central neurocytoma (CN) is a rare, benign brain tumor often located in the lateral ventricles. CN may cause obstructive hydrocephalus and manifest as signs of increased intracranial pressure. The goal of treatment for CN is a gross total resection (GTR), which often yields excellent prognosis with a very high rate of tumor control and survival. Adjuvant radiosurgery and radiotherapy may be considered to improve tumor control when GTR cannot be achieved. Chemotherapy is also not considered a primary treatment, but has been used as a salvage therapy. The radiological features of CN are indistinguishable from those of other brain tumors; therefore, many histological markers, such as synaptophysin, can be very useful for diagnosing CNs. Furthermore, the MIB-1 Labeling Index seems to be correlated with the prognosis of CN. We also discuss oncogenes associated with these elusive tumors. Further studies may improve our ability to accurately diagnose CNs and to design the optimal treatment regimens for patients with CNs.