hglobal-Index: A Novel Author-Level Measure of the Diffusion of Scientific Ideas Among High-, Low-, and Middle-Income Countries.

OBJECTIVE: To describe an intuitive and useful method for measuring the global impact of a medical scholar's research ideas by examining cross-border citations (CBCs) of peer-reviewed neurosurgical publications. METHODS: Publication and citation data for a random sample of the top 50 most academically productive neurosurgeons were obtained from Scopus Application Programming Interface. We characterized an author-level global impact index analogous to the widely used h-index, the hglobal-index, defined as the number of published peer-reviewed manuscripts with at least the same number of CBCs. To uncover socioeconomic insights, we explored the hglobal-index for high-, middle-, and low-income countries. RESULTS: The median (interquartile range) number of publications and CBCs were 144 (62-255) and 2704 (959-5325), respectively. The median (interquartile range) h-index and hglobal-index were 42 (23-61) and 32 (17-38), respectively. Compared with neurosurgeons in the random sample, the 3 global neurosurgeons had the highest hglobal-indices in low-income countries at 17, 13, and 9, despite below-average h-index scores of 33, 38, and 19, respectively. CONCLUSION: This intuitive update to the h-index uses CBCs to measure the global impact of scientific research. The hglobal-index may provide insight into global diffusion of medical ideas, which can be used for social science research, author self-assessment, and academic promotion.

Magnetic Resonance-Guided Laser Interstitial Thermal Therapy for Recurrent Glioblastoma and Radiation Necrosis: A Single-Surgeon Case Series.

OBJECTIVE: To evaluate long-term clinical outcomes among patients treated with laser interstitial thermal therapy (LITT) for predicted recurrent glioblastoma (rGBM). METHODS: Patients with rGBM treated by LITT by a single surgeon (2013-2020) were evaluated for progression-free survival (PFS), overall survival (OS), and OS after LITT. RESULTS: Forty-nine patients (33 men, 16 women; mean [SD] age at diagnosis, 58.7 [12.5] years) were evaluated. Among patients with genetic data, 6 of 34 (18%) had IDH-1 R132 mutations, and 7 of 21 (33%) had MGMT methylation. Patients underwent LITT at a mean (SD) of 23.8 (23.8) months after original diagnosis. Twenty of 49 (40%) had previously undergone stereotactic radiosurgery, 37 (75%) had undergone intensity-modulated radiation therapy, and 49 (100%) had undergone chemotherapy. Patients had undergone a mean of 1.2 (0.7) previous resections before LITT. Mean preoperative enhancing and T2 FLAIR volumes were 13.1 (12.8) cm3 and 35.0 (32.8) cm3, respectively. Intraoperative biopsies confirmed rGBM in 31 patients (63%) and radiation necrosis in 18 patients (37%). Six perioperative complications occurred: 3 (6%) cases of worsening aphasia, 1 (2%) seizure, 1 (2%) epidural hematoma, and 1 (2%) intraparenchymal hemorrhage. For the rGBM group, median PFS was 2.0 (IQR, 4.0) months, median OS was 20.0 (IQR, 29.5) months, and median OS after LITT was 6.0 (IQR, 10.5) months. For the radiation necrosis group, median PFS was 4.0 (IQR, 4.5) months, median OS was 37.0 (IQR, 58.0) months, and median OS after LITT was 8.0 (IQR, 23.5) months. CONCLUSIONS: In a diverse rGBM cohort, LITT was associated with a short duration of posttreatment PFS.

Endoscopic Endonasal Transsphenoidal Approach to Repair Cerebrospinal Fluid Rhinorrhea After an Anterior Clinoidectomy for Aneurysm Clipping: Series of 4 Cases.

BACKGROUND: Cerebrospinal fluid (CSF) rhinorrhea through a pneumatized optic strut is a known potential complication after an anterior clinoidectomy that is used to microsurgically clip a proximal internal carotid artery aneurysm. The original craniotomy site can be reopened to repair the skull base defect, but this technique has disadvantages. OBJECTIVE: To avoid a repeat craniotomy and address the limitations of a transcranial approach, a straightforward alternative was used for skull base repair-the binostril endoscopic endonasal transsphenoidal approach. METHODS: This retrospective case series describes the use of endoscopic transsphenoidal repair and outcomes for patients with CSF leaks after anterior clinoidectomy for aneurysm repair between January 1, 2015, and December 31, 2019. RESULTS: Four adult patients (3 women and 1 man) with a mean age of 59.5 years were reviewed. Skull base repair occurred on average 24 days (range, 4-75 days) after the index operation. After demucosalization of the parasellar sphenoid sinus, the fistula in the pneumatized optic strut was reconstructed with a free nasal mucosal graft with or without an autologous muscle graft. None of the patients developed a recurrent CSF leak at a mean follow-up of 12.5 months (range, 8-22 months), and none experienced complications. CONCLUSION: The endoscopic endonasal transsphenoidal approach was safe and effective for skull base repair in 4 patients with CSF rhinorrhea after an anterior clinoidectomy for aneurysm clipping.

Magnetic Resonance-Guided Laser Interstitial Thermal Therapy for Management of Low-Grade Gliomas and Radiation Necrosis: A Single-Institution Case Series.

BACKGROUND: Laser interstitial thermal therapy (LITT) has emerged as a minimally invasive treatment modality for ablation of low-grade glioma (LGG) and radiation necrosis (RN). OBJECTIVE: To evaluate the efficacy, safety, and survival outcomes of patients with radiographically presumed recurrent or newly diagnosed LGG and RN treated with LITT. METHODS: The neuro-oncological database of a quaternary center was reviewed for all patients who underwent LITT for management of LGG between 1 January 2013 and 31 December 2020. Clinical data including demographics, lesion characteristics, and clinical and radiographic outcomes were collected. Kaplan-Meier analyses comprised overall survival (OS) and progression-free survival (PFS). RESULTS: Nine patients (7 men, 2 women; mean [SD] age 50 [16] years) were included. Patients underwent LITT at a mean (SD) of 11.6 (8.5) years after diagnosis. Two (22%) patients had new lesions on radiographic imaging without prior treatment. In the other 7 patients, all (78%) had surgical resection, 6 (67%) had intensity-modulated radiation therapy and chemotherapy, respectively, and 4 (44%) had stereotactic radiosurgery. Two (22%) patients had lesions that were wild-type IDH1 status. Volumetric assessment of preoperative T1-weighted contrast-enhancing and T2-weighted fluid-attenuated inversion recovery (FLAIR) sequences yielded mean (SD) lesion volumes of 4.1 (6.5) cm3 and 26.7 (27.9) cm3, respectively. Three (33%) patients had evidence of radiographic progression after LITT. The pooled median (IQR) PFS for the cohort was 52 (56) months, median (IQR) OS after diagnosis was 183 (72) months, and median (IQR) OS after LITT was 52 (60) months. At the time of the study, 2 (22%) patients were deceased. CONCLUSIONS: LITT is a safe and effective treatment option for management of LGG and RN, however, there may be increased risk of permanent complications with treatment of deep-seated subcortical lesions.

Nationwide Readmission Rates and Hospital Charges for Patients With Surgical Evacuation of Nontraumatic Subdural Hematomas: Part 2-Burr Hole Craniostomy.

BACKGROUND: Nontraumatic subdural hematoma (SDH) is a common neurological disease that causes extensive morbidity and mortality. Craniotomy or burr hole craniostomy (BHC) is indicated for symptomatic lesions, but both are associated with high recurrence rates. Although extensive research exists on postoperative complications after BHCs, few studies have examined the underlying causes and predictors of unplanned 30-day hospital readmissions at the national level. OBJECTIVE: To compare causes for hospital readmission within 30 days after surgical SDH evacuation with BHC and evaluate readmission rates and independent predictors of readmission. METHODS: This retrospective cohort observational study was designed using the Nationwide Readmissions Database. We identified patients who had undergone BHC for SDH evacuation (2010-2015). National estimates and variances within the cohort were calculated after stratifying, hospital clustering, and weighting variables. RESULTS: We analyzed 2753 patients who had BHC for SDH evacuation: 675 (24.5%) had at least one 30-day readmission. Annual readmission rates did not vary across the study period ( P = .60). The most common cause of readmission was recurrent SDH (n = 630, 93.3%), and the next most common was postoperative infection (n = 12, 1.8%). Comorbidities significantly associated with readmission included fluid and electrolyte disorders, chronic blood loss anemia, chronic obstructive pulmonary disease, depression, liver disease, and psychosis ( P ≤ .04), but statistically significant independent predictors for readmission included only chronic obstructive pulmonary disease and fluid and electrolyte disorders ( P ≤ .007). CONCLUSION: These national trends in 30-day readmission rates after nontraumatic SDH evacuation by BHC not otherwise published provide quality benchmarks that can aid national quality improvement efforts.

Perioperative Complication Profile of Skull Base Meningioma Resection in Older versus Younger Adult Patients.

Objectives To better understand the risk-benefit profile of skull base meningioma resection in older patients, we compared perioperative complications among older and younger patients. Design Present study is based on retrospective outcomes comparison. Setting The study was conducted at a single neurosurgery institute at a quaternary center. Participants All older (age ≥ 65 years) and younger (<65 years) adult patients treated with World Health Organization grade 1 skull base meningiomas (2008-2017). Main Outcome Measures Perioperative complications and patient functional status are the primary outcomes of this study. Results The analysis included 287 patients, 102 older and 185 younger, with a mean (standard deviation [SD]) age of 72 (5) years and 51 (9) years ( p < 0.01). Older patients were more likely to have hypertension ( p < 0.01) and type 2 diabetes mellitus ( p = 0.01) but other patient and tumor factors did not differ ( p ≥ 0.14). Postoperative medical complications were not significantly different in older versus younger patients (10.8 [11/102] vs. 4.3% [8/185]; p = 0.06) nor were postoperative surgical complications (13.7 [14/102] vs. 10.8% [20/185]; p = 0.46). Following anterior skull base meningioma resection, diabetes insipidus (DI) was more common in older versus younger patients (14 [5/37] vs. 2% [1/64]; p = 0.01). Among older patients, a decreasing preoperative Karnofsky performance status score independently predicted perioperative complications by logistic regression analysis ( p = 0.02). Permanent neurologic deficits were not significantly different in older versus younger patients (12.7 [13/102] vs. 10.3% [19/185]; p = 0.52). Conclusion The overall perioperative complication profile of older and younger patients was similar after skull base meningioma resection. Older patients were more likely to experience DI after anterior skull base meningioma resection. Decreasing functional status in older patients predicted perioperative complications.

Nationwide Readmission Rates and Hospital Charges for Patients With Surgical Evacuation of Nontraumatic Subdural Hematomas: Part 1-Craniotomy.

BACKGROUND: Despite patients experiencing high recurrence and readmission rates after surgical management of nontraumatic subdural hematomas (SDHs), few studies have examined the causes and predictors of unplanned readmissions in this population on a national scale. OBJECTIVE: To analyze independent factors predicting 30-day hospital readmissions after surgical treatment of nontraumatic SDH in patients who survived their index surgery and evaluate hospital readmission rates and charges. METHODS: Using the Nationwide Readmissions Database, we identified patients who underwent craniotomy for nontraumatic SDH evacuation (2010-2015) using a retrospective cohort observational study design. National estimates and variances within the cohort were calculated after stratifying, hospital clustering, and weighting variables. RESULTS: Among 49 013 patients, 10 643 (21.7%) had at least 1 readmission within 30 days of their index treatment and 38 370 (78.3%) were not readmitted. Annual readmission rates did not change during the study period ( P = .74). The most common primary causes of 30-day readmissions were recurrent SDH (n = 3949, 37.1%), venous thromboembolism (n = 1373, 12.9%), and delayed hyponatremia and syndrome of inappropriate antidiuretic hormone secretion (n = 1363, 12.8%). Comorbidities that independently predicted readmission included congestive heart failure, chronic obstructive pulmonary disease, coagulopathy, diabetes mellitus, liver disease, lymphoma, fluid and electrolyte disorders, metastatic cancer, peripheral vascular disease, psychosis, and renal failure ( P ≤ .03). Household income in the 51st to 75th percentile was associated with a decreased risk of readmission. CONCLUSION: National trends in 30-day readmission rates after nontraumatic SDH treatment by craniotomy provide quality benchmarks that can be used to drive quality improvement efforts on a national level.

National trends in hospital readmission following transsphenoidal surgery for pituitary lesions.

PURPOSE: Several institutions recently published their experiences with unplanned readmissions rates after transsphenoidal surgery for pituitary lesions. Readmission rates on a national level, however, have not been explored in depth. We investigated nationwide trends in this procedure and associated independent predictors, costs, and causes of 30-day readmission. METHODS: The Nationwide Readmissions Database was queried to identify patients 18 and older who underwent transsphenoidal surgery for pituitary lesion resection (2010-2015). National trends and statistical variances were calculated based on weighted, clustered, and stratified sample means. RESULTS: Of the weighted total of 44,759 patients treated over the 6-year period, 4658 (10.4%) were readmitted within 30 days. Readmission rates did not change across the survey period (P = 0.71). Patients readmitted had a higher prevalence of comorbidities than those not readmitted (82.5% vs. 78.4%, respectively, P < 0.001), experienced more postoperative complications (47.2% vs. 31.8%, P < 0.001), and had a longer length of stay (6.59 vs. 4.23 days, P < 0.001) during index admission. The most common causes for readmission were SIADH (17.5%) and other hyponatremia (16.4%). Average total readmission cost was $12,080 with no significant trend across the study period (P = 0.25). Predictors for readmission identified included diabetes mellitus, psychological disorders, renal failure, and experiencing diabetes insipidus during the index admission. CONCLUSION: Unplanned readmission is an important quality metric. While transsphenoidal pituitary surgery is a relatively safe procedure, 30-day readmission rates and costs have not declined. Future studies on institutional protocols targeting these identified predictors to prevent readmission are necessary to decrease readmission rates on a national scale.