On-Call Workload Differences in Neurosurgery: Resident Call "Weather" and a Departure from Colored Cloud Labels.

BACKGROUND AND OBJECTIVES: Labeling residents as "black" or "white" clouds based on perceived or presumed workloads is a timeworn custom across medical training and practice. Previous studies examining whether such perceptions align with objective workload patterns have offered conflicting results. We assessed whether such peer-assigned labels were associated with between-resident differences in objective, on-call workload metrics in three classes of neurosurgery junior residents. In doing so, we introduce more inclusive terminology for perceived differences in workload metrics. METHODS: Residents were instructed to complete surveys to identify "sunny", "neutral", and "stormy" residents, reflecting least to greatest perceived workloads, of their respective classes. We retrospectively reviewed department and electronic medical records to record volume of on-call work over the first 4 months of each resident's 2nd postgraduate academic year. Inter-rater agreement of survey responses was measured using Fleiss' kappa. All statistical analyses were performed with a significance threshold of P < .05. RESULTS: Across all classes, there was strong inter-rater agreement in the identification of stormy and sunny residents (Kappa = 1.000, P = .003). While differences in on-call workload measures existed within each class, "weather" designations did not consistently reflect these differences. There were significant intraclass differences in per shift consult volume in two classes ( P = .035 and P = .009); however, consult volume corresponded to a resident's weather designations in only one class. Stormy residents generally saw more emergencies and, in 2 classes, performed more bedside procedures than their peers. CONCLUSION: Significant differences in objective on-call experience exist between junior neurosurgery residents. Self- and peer-assigned weather labels did not consistently align with a pattern of these differences, suggesting that other factors contribute to such labels.

Bone morphogenetic protein and cancer in spinal fusion: a propensity score-matched analysis.

OBJECTIVE: Bone morphogenetic protein (BMP) has been increasingly used in spinal surgery to promote arthrodesis. Because BMP stimulates cellular proliferation, its association with tumorigenesis is a concern. Previous research has generated conflicting conclusions on the risk of cancer in patients receiving BMP. The authors aimed to compare the incidence of solid organ and hematopoietic malignancies in patients undergoing spinal arthrodesis with or without BMP. METHODS: The PearlDiver Mariner Patient Claims Database was queried for patients undergoing thoracolumbar fusion between 2015 and 2021. Patients with preexisting malignancy were excluded. Data were analyzed for incidence of solid organ malignancy and hematopoietic malignancy diagnosed after spinal surgery. Propensity score matching using age, sex, tobacco usage, and year of surgery was performed between patients who did and those who did not receive BMP. RESULTS: Among patients without prior solid organ malignancy, BMP was used in 22,139 patients and not used in 306,249. In the propensity score-matched group, 3.1% of the BMP group developed solid organ malignancy following surgery compared with 3.5% in the non-BMP group. The relative risk (RR) of developing solid organ malignancy after BMP exposure was 0.89 (95% CI 0.81-0.98, p = 0.02). Among patients without prior hematopoietic malignancy, BMP was used in 23,505 patients and not used in 328,796 patients. In the propensity score-matched group, 0.4% of the BMP group developed hematopoietic malignancy compared with 0.6% of the non-BMP group. The RR of developing hematopoietic malignancy after BMP exposure was 0.71 (95% CI 0.55-0.93, p = 0.015). CONCLUSIONS: BMP use in thoracolumbar fusion was not associated with an increased risk of new malignancy, which further supports emerging data on the lack of an association between BMP use and increased malignancy.

Milestones for neurosurgery sub-interns: a novel evaluation tool to quantitatively differentiate residency applicants.

OBJECTIVE: The study objective was to create a novel milestones evaluation form for neurosurgery sub-interns and assess its potential as a quantitative and standardized performance assessment to compare potential residency applicants. In this pilot study, the authors aimed to determine the form's interrater reliability, relationship to percentile assignments in the neurosurgery standardized letter of recommendation (SLOR), ability to quantitatively differentiate tiers of students, and ease of use. METHODS: Medical student milestones were either adapted from the resident Neurological Surgery Milestones or created de novo to evaluate a student's medical knowledge, procedural aptitude, professionalism, interpersonal and communication skills, and evidence-based practice and improvement. Four milestone levels were defined, corresponding to estimated 3rd-year medical student through 2nd-year resident levels. Faculty and resident evaluations as well as student self-evaluations were completed for 35 sub-interns across 8 programs. A cumulative milestone score (CMS) was computed for each student. Student CMSs were compared both within and between programs. Interrater reliability was determined with Kendall's coefficient of concordance (Kendall's W). Student CMSs were compared against their percentile assignments in the SLOR using analysis of variance with post hoc testing. CMS-derived percentile rankings were assigned to quantitatively distinguish tiers of students. Students and faculty were surveyed on the form's usefulness. RESULTS: The average faculty rating overall was 3.20, similar to the estimated competency level of an intern. Student and faculty ratings were similar, whereas resident ratings were lower (p < 0.001). Students were rated most highly in coachability and feedback (3.49 and 3.67, respectively) and lowest in bedside procedural aptitude (2.90 and 2.85, respectively) in both faculty and self-evaluations. The median CMS was 26.5 (IQR 21.75-29.75, range 14-32) with only 2 students (5.7%) achieving the highest rating of 32. Programs that evaluated the most students differentiated the highest-performing students from the lowest by at least 13 points. A program with 3 faculty raters demonstrated scoring agreement across 5 students (p = 0.024). The CMS differed significantly between SLOR percentile assignments, despite 25% of students being assigned to the top fifth percentile. CMS-driven percentile assignment significantly differentiated the bottom, middle, and top third of students (p < 0.001). Faculty and students strongly endorsed the milestones form. CONCLUSIONS: The medical student milestones form was well received and differentiated neurosurgery sub-interns both within and across programs. This form has potential as a replacement for numerical Step 1 scoring as a standardized, quantitative performance assessment for neurosurgery residency applicants.

Surgical site infection in thoracic and lumbar fractures: incidence and risk factors in 11,401 patients from a nationwide administrative database.

BACKGROUND CONTEXT: The rate of surgical site infection (SSI) following elective spine surgery ranges from 0.5%‒10%. Published reports suggest a higher SSI rate in non-elective spine surgery such as spine trauma; however, there is a paucity of large database studies examining this issue. PURPOSE: The objective of this study was to investigate the incidence and risk factors of SSI in patients undergoing spine surgery for thoracic and lumbar fractures in a large population database. STUDY DESIGN/SETTING: This is a retrospective study utilizing the PearlDiver Patient Claims Database. PATIENT SAMPLE: Patients undergoing spine surgery for thoracic and lumbar fractures between 2015-2020 were identified in the PearlDiver Patient Claims Database using ICD-10 codes. Patients were excluded who had another surgery either 14 days before or 21 days after the index spine surgery, or pathologic fracture. OUTCOME MEASURES: Rate of surgical site infection. METHODS: Clinical data collected from the PearlDiver database based on ICD-10 codes included gender, age, diabetes, smoking status, obesity, Elixhauser Comorbidity Index (ECI), Charlson Comorbidity Index (CCI), and SSI. Univariate analysis was used to assess the association of potential risk factors and SSI. Multivariable analysis was used to identify independent risk factors of SSI. The authors have no conflicts of interest or funding sources to declare. RESULTS: A total of 11,401 patients undergoing spine surgery for thoracic and lumbar fractures met inclusion criteria, and 1,065 patients were excluded. 860 patients developed SSI (7.5%). Risk factors significantly associated with SSI in univariate analysis included diabetes (OR 1.50; 95% CI, 1.30‒1.73; p<.001), obesity (OR 1.66; 95% CI, 1.44‒1.92; p<.001), increased age (p<.001), ECI (p<.001), and CCI (p<.001). On multivariable analysis, obesity and ECI were independently associated with SSI (p<.001 and p<.001, respectively). CONCLUSIONS: Non-elective surgery for thoracic and lumbar fractures is associated with a 7.5% risk of SSI. Obesity and ECI are independent predictors of SSI in this population. Limitations include the reliance on accurate insurance coding which may not fully capture all SSI, and in particular superficial SSI. These findings provide a broad overview of the risk of SSI in this population at a national level and may also help counsel patients regarding risk.

Utilization of Vertebroplasty/Kyphoplasty in the Management of Compression Fractures: National Trends and Predictors of Vertebroplasty/Kyphoplasty.

OBJECTIVE: The purpose of this study is to examine the utilization of kyphoplasty/vertebroplasty procedures in the management of compression fractures. With the growing elderly population and the associated increase in rates of osteoporosis, vertebral compression fractures have become a daily encounter for spine surgeons. However, there remains a lack of consensus on the optimal management of this patient population. METHODS: A retrospective analysis of 91 million longitudinally followed patients from 2016 to 2019 was performed using the PearlDiver Patient Claims Database. Patients with compression fractures were identified using International Classification of Disease, 10th Revision codes, and a subset of patients who received kyphoplasty/vertebroplasty were identified using Common Procedural Terminology codes. Baseline demographic and clinical data between groups were acquired. Multivariable regression analysis was performed to determine predictors of receiving kyphoplasty/vertebroplasty. RESULTS: A total of 348,457 patients with compression fractures were identified with 9.2% of patients receiving kyphoplasty/vertebroplasty as their initial treatment. Of these patients, 43.5% underwent additional kyphoplasty/vertebroplasty 30 days after initial intervention. Patients receiving kyphoplasty/vertebroplasty were significantly older (72.2 vs. 67.9, p < 0.05), female, obese, had active smoking status and had higher Elixhauser Comorbidity Index scores. Multivariable analysis demonstrated that female sex, smoking status, and obesity were the 3 strongest predictors of receiving kyphoplasty/vertebroplasty (odds ratio, 1.27, 1.24, and 1.14, respectively). The annual rate of kyphoplasty/vertebroplasty did not change significantly (range, 8%-11%). CONCLUSION: The majority of vertebral compression fractures are managed nonoperatively. However, certain patient factors such as smoking status, obesity, female sex, older age, osteoporosis, and greater comorbidities are predictors of undergoing kyphoplasty/vertebroplasty.

Effects of 24-hour versus night-float call schedules on the clinical and operative experiences of postgraduate year 2 and 3 neurosurgical residents.

OBJECTIVE: To comply with the removal of the 88-hour week exemption and to support additional operative experience during junior residency, Oregon Health & Science University (OHSU) switched from a night-float call schedule to a modified 24-hour call schedule on July 1, 2019. This study compared the volumes of clinical, procedural, and operative cases experienced by postgraduate year 2 (PGY-2) and PGY-3 residents under these systems. METHODS: The authors retrospectively studied billing and related clinical records, call schedules, and Accreditation Council for Graduate Medical Education case logs for PGY-2 and PGY-3 residents at OHSU, a tertiary academic health center, for the first 4 months of the academic years from 2017 to 2020. The authors analyzed the volumes of new patient consultations, bedside procedures, and operative procedures performed by each PGY-2 and PGY-3 resident during these years, comparing the volumes experienced under each call system. RESULTS: Changing from a PGY-2 resident-focused night-float call system to a 24-hour call system that was more evenly distributed between PGY-2 and PGY-3 residents resulted in decreased volume of new patient consultations, increased volume of operative procedures, and no change in volume of bedside procedures for PGY-2 residents. PGY-3 residents experienced a decrease in operative procedure volume under the 24-hour call system. CONCLUSIONS: Transition from a night-float system to a 24-hour call system altered the distribution of clinical and procedural experiences between PGY-2 and PGY-3 residents. Further research is necessary to understand the impact of these changes on educational outcomes, quality and safety of patient care, and resident satisfaction.

A Reappraisal of Anterior Communicating Artery Aneurysms: A Case for Stent-Assisted Embolization.

BACKGROUND: Wide-necked anterior communicating artery aneurysms represent a subset of lesions with challenging endovascular treatment despite new endoluminal and intrasaccular devices. OBJECTIVE: To assess the long-term clinical and angiographic outcomes of stent-assisted embolization for wide-necked anterior communicating artery aneurysms. METHODS: Between March 2008 and March 2014, 32 patients with unruptured wide-necked AComm aneurysms were treated using stent-assisted embolization. The Glasgow Outcome Scale was reviewed at the time of discharge and at latest follow-up. Ischemic and hemorrhagic events were also recorded and analyzed. Aneurysm occlusion was evaluated post-intervention and on subsequent follow-up evaluations. RESULTS: Successful stent deployment was achieved in all cases, but in 1 patient the coils could not be contained inside the aneurysm, and the procedure was aborted without complications. The distal segment of the stent was positioned in the ipsilateral A2 in 16 patients, in the contralateral A2 in 15 patients, and in the contralateral A1 in 1 patient. There were no periprocedural thromboembolic or hemorrhagic complications. The rate of major complications was 6%. One patient developed intracranial hemorrhage related to antiplatelet therapy and another had ischemic events due to in-stent stenosis. Angiographic follow-up was available for 26 aneurysms and during a mean follow-up of 22 months, 81% of the lesions were completely occluded and 8% had a small residual neck. The retreatment rate for residual aneurysms was 3%. CONCLUSION: Our long-term results suggest that stent-assisted embolization for anterior communicating artery aneurysms may be considered an excellent treatment option with an adequate combination of safety profile and effectiveness.

Familial intracranial dural arteriovenous fistulas.

BACKGROUND AND IMPORTANCE: Intracranial dural arteriovenous fistulas (DAVFs) are acquired abnormal communications between dural arteries and veins. Risk factors for development include sinus thrombosis and hypercoagulability, such as occurs in heritable thrombophilias. While there have been reports of other types of vascular anomalies (such as cavernous and arteriovenous malformations) occurring in families, to our knowledge there have been no reports of familial intracranial DAVFs. We describe the first 2 cases of intracranial DAVFs occurring in first-degree relatives. CLINICAL PRESENTATION: A 66-year-old woman presented with an 18-month history of bilateral pulsatile tinnitus. Neurological examination was significant for a prominent pulsatile bruit over the left mastoid region. Laboratory studies demonstrated heterozygosity for Prothrombin G20210A mutation. Imaging disclosed a large left Type I Borden DAVF involving the distal transverse-sigmoid sinus junction. She underwent uncomplicated stereotactic radiosurgery to the fistula that led to complete resolution of her tinnitus and the fistula. A 73-year-old woman, the sister of the previous patient, presented with a 24-month history of pulsatile tinnitus affecting the left ear. Laboratory studies demonstrated heterozygosity for the Prothrombin G20210A mutation. Imaging revealed a left Type I Borden DAVF involving the left transverse and sigmoid sinuses. The patient's symptoms resolved spontaneously without treatment. Repeat imaging revealed interval involution of the fistula. CONCLUSION: We describe 2 sisters who were heterozygous for Prothrombin G20210A mutation and found to have DAVFs. Clinicians should be aware of the potential for these fistulas to congregate in first-degree relatives via heritable thrombophilias such as the Prothrombin G20210A mutation.

Redefining the relevance of established cancer cell lines to the study of mechanisms of clinical anti-cancer drug resistance.

Although in vitro models have been a cornerstone of anti-cancer drug development, their direct applicability to clinical cancer research has been uncertain. Using a state-of-the-art Taqman-based quantitative RT-PCR assay, we investigated the multidrug resistance (MDR) transcriptome of six cancer types, in established cancer cell lines (grown in monolayer, 3D scaffold, or in xenograft) and clinical samples, either containing >75% tumor cells or microdissected. The MDR transcriptome was determined a priori based on an extensive curation of the literature published during the last three decades, which led to the enumeration of 380 genes. No correlation was found between clinical samples and established cancer cell lines. As expected, we found up-regulation of genes that would facilitate survival across all cultured cancer cell lines evaluated. More troubling, however, were data showing that all of the cell lines, grown either in vitro or in vivo, bear more resemblance to each other, regardless of the tissue of origin, than to the clinical samples they are supposed to model. Although cultured cells can be used to study many aspects of cancer biology and response of cells to drugs, this study emphasizes the necessity for new in vitro cancer models and the use of primary tumor models in which gene expression can be manipulated and small molecules tested in a setting that more closely mimics the in vivo cancer microenvironment so as to avoid radical changes in gene expression profiles brought on by extended periods of cell culture.

Evaluation of current methods used to analyze the expression profiles of ATP-binding cassette transporters yields an improved drug-discovery database.

The development of multidrug resistance (MDR) to chemotherapy remains a major challenge in the treatment of cancer. Resistance exists against every effective anticancer drug and can develop by multiple mechanisms. These mechanisms can act individually or synergistically, leading to MDR, in which the cell becomes resistant to a variety of structurally and mechanistically unrelated drugs in addition to the drug initially administered. Although extensive work has been done to characterize MDR mechanisms in vitro, the translation of this knowledge to the clinic has not been successful. Therefore, identifying genes and mechanisms critical to the development of MDR in vivo and establishing a reliable method for analyzing highly homologous genes from small amounts of tissue is fundamental to achieving any significant enhancement in our understanding of MDR mechanisms and could lead to treatments designed to circumvent it. In this study, we use a previously established database that allows the identification of lead compounds in the early stages of drug discovery that are not ATP-binding cassette (ABC) transporter substrates. We believe this can serve as a model for appraising the accuracy and sensitivity of current methods used to analyze the expression profiles of ABC transporters. We found two platforms to be superior methods for the analysis of expression profiles of highly homologous gene superfamilies. This study also led to an improved database by revealing previously unidentified substrates for ABCB1, ABCC1, and ABCG2, transporters that contribute to MDR.