Back to basal: contemporary cerebrovascular cohort study of the supratentorial-infraoccipital approach.

OBJECTIVE: The objective of this paper was to assess applications of the supratentorial-infraoccipital (STIO) approach for cerebrovascular neurosurgery. METHODS: The authors conducted a cohort study of all consecutive cases in which the STIO approach was used during the study period, December 1995 to January 2021, as well as a systematic review of the literature. RESULTS: Twenty-five cerebrovascular cases were identified in which the STIO approach was used. Diagnoses included arteriovenous malformation (n = 15), cerebral cavernous malformation (n = 5), arteriovenous fistula (n = 4), and aneurysm (n = 1). The arteriovenous malformations consisted of Spetzler-Martin grade II (n = 3), grade III (n = 8), and grade IV (n = 4) lesions. Lesion locations included the occipital lobe (n = 15), followed by the tentorial dural (n = 4), temporal-occipital (n = 3), temporal (n = 1), thalamic (n = 1), and quadrigeminal cistern (n = 1) regions. Many patients (75%) experienced transient visual deficits attributable to retraction of the occipital lobe, all of which resolved. As of last follow-up (n = 12), modified Rankin Scale scores had improved for 6 patients and were unchanged for 6 patients compared with the preoperative baseline. CONCLUSIONS: The STIO approach is a safe and effective skull base approach that provides a specialized access corridor for appropriately selected cerebrovascular lesions.

Trends in Matriculation from Neurological Surgery Training Programs into Academic Versus Private Practice.

OBJECTIVE: A career in academic neurosurgery is an arduous endeavor. Specific factors influencing physician practice preferences remain unclear. This study analyzes data from the American Association of Neurological Surgeons membership identifying the impact of several demographic and educational characteristics influencing neurosurgical career choices centered on academia, private practice, or a combination in the United States. METHODS: A list of all current neurosurgeons was obtained from the American Association of Neurological Surgeons membership, and information on physician characteristics was collected via internet searches and institutional databases. The practice type of all neurosurgeons considered in this study were categorized as follows: private practice, academic, or a combination of private practice and academic, termed privademic. These data were subsequently correlated to race, gender, current age, training at a top 40 National Institutes of Health-funded medical school or residency program, and current practice. RESULTS: The median age of private practice and academic neurosurgeons was 58.18 and 53.61 years, respectively (P < 0.001). Age was significantly associated with practicing in an academic setting (odds ratio 0.96), with younger neurosurgeons pursuing careers in academia. Data indicated a positive and statistically significant contribution of female gender (P < 0.001) and training at a top-40 National Institutes of Health-funded institution to practicing in an academic setting (P < 0.01). CONCLUSIONS: Neurosurgery as a field has grown significantly over the past century. The authors recommend that future efforts seek to diversify the neurosurgical workforce by considering practice setting, demographic characteristics, and educational background.

Political Campaign Contributions of Surgeons in the United States Throughout the 2020 Election Cycle.

Importance: Political engagement by the physician workforce is necessary to ensure continued representation of their interests in health care legislation. Limited data are available pertaining to the political involvement of US surgeons. Objective: To analyze the magnitude and distribution of political donations made by all US surgeons throughout the 2020 election cycle. Design, Setting, and Participants: Partisan and geographical differences in surgeon contributions by aggregating data (January 1 through December 31, 2020) from the US Federal Election Commission database were analyzed. Contributions were labeled as Republican, Democrat, or independent depending on the committee they were designated to. Main Outcomes and Measures: Differences in contributions to Republicans, Democrats, and independent candidates for all US surgeons and for subgroups. Results: For the 2020 election year, a total of 53 944 donations were made by surgeons in the United States, amounting to $9 223 350.68. Among all surgical specialties, the top 5 highest number of contributions were made from orthopedic surgeons (n = 15 081), ophthalmic surgeons (n = 14 836), neurological surgeons (n = 7481), urologists (n = 4544), and plastic surgeons (n = 4060). Of these donations, 59.46% (n = 32 107) were made to the Republican party ($5 420 326), 30.83% (n = 16 644) were made to the Democratic party ($1 612 775), and 9.71% (n = 5243) were made to nonpartisan (ie, independent) organizations ($2 190 250). Overall, pediatric surgeons reported the lowest mean contribution amount of $59.43, whereas thoracic surgeons reported the highest mean contribution amount of $225.19. Conclusions and Relevance: Health care legislation has an immense impact on how medicine is practiced and utilized. This analysis reveals a high degree of political activity of surgeons across different specialties and geographic regions.

Evolution of Intracranial-Intracranial Bypass Surgery: A Bibliometric Analysis.

OBJECTIVE: Modern cerebrovascular bypass surgery uses either extracranial-intracranial (EC-IC) or intracranial-intracranial (IC-IC) approaches. Compared with EC-IC bypasses, IC-IC bypasses allow neurosurgeons to safely address tumors, aneurysms, and other lesions using shorter grafts that are well matched to the size of recipient vessels. Fewer than 100 articles have been published on IC-IC bypasses compared with more than 1000 on EC-IC bypasses. This study examined the increase of interest and innovation in IC-IC bypass. METHODS: PubMed and Web of Science were searched using keywords specific to IC-IC bypass, yielding 717 articles supplemented with 36 reports from other databases and gray literature. The articles were reviewed, and 98 articles were selected for further evaluation. Final articles were categorized as innovations or retrospective studies. Publication metrics were passed through an analytic program to assess statistical measures of growth. RESULTS: The number of publications describing innovations (n = 52) and retrospective studies (n = 46) in IC-IC surgical techniques increased exponentially (R2 = 0.983 and R2 = 0.993, respectively), with both interest and research in the field increasing. The rate of publications in each group also increased. In recent years, increasing numbers of global institutions have researched and published on IC-IC bypasses. CONCLUSIONS: As more work is undertaken on IC-IC bypasses, it is critical for knowledge to be shared through research, collaboration, publication, and early teaching within residency training programs. This field has increased exponentially in the past 2 decades and has yet to reach an inflection point, indicating possible additional interest and growth over time.

Optimizing the residency application process: insights from neurological surgery during the pandemic virtual application cycle.

OBJECTIVE: In this article, the authors describe the impact of the COVID-19 virtual match cycle and discuss approaches to optimize future cycles through applicant and neurosurgical education leadership insights. METHODS: Anonymous surveys of neurosurgery program leaders (program directors and program chairs), program administrators (PAs), and 2020-2021 neurosurgery residency match applicants were distributed by the SNS, in conjunction with the Association of Resident Administrators in Neurological Surgery and AANS Young Neurosurgeons Committee. RESULTS: Responses were received from 77 (67.0%) of 115 PAs, 119 (51.7%) of 230 program leaders, and 124 (44.3%) of 280 applicants representing geographically diverse regions. During the virtual application cycle relative to the previous year, programs received more Electronic Residency Application Service applications (mean 314.8 vs 285.3, p < 0.0001) and conducted more applicant interviews (mean 45.2 vs 39.9, p = 0.0003). More than 50% of applicants applied to > 80 programs; 60.3% received ≤ 20 interview invitations, and 9% received > 40 invitations. Overall, 65% of applicants completed ≤ 20 interviews, whereas 34.7% completed > 20 interviews. Program leaders described one 4-week home subinternship (93.3%) and two 4-week external subinternships (68.9%) as optimal neurosurgical exposure; 62.8% of program leaders found the standardized letter of recommendation template to be somewhat (47.5%) or significantly (15.3%) helpful. Applicants, PAs, and program leaders all strongly preferred a hybrid model of in-person and virtual interview options for future application cycles over all in-person or all virtual options. Ninety-three percent of applicants reported matching within their top 10-ranked programs, and 52.9% of programs matched residents within the same decile ranking as in previous years. CONCLUSIONS: Optimizing a national strategy for the neurosurgery application process that prioritizes equity and reduces costs, while ensuring adequate exposure for applicants to gain educational opportunities and evaluate programs, is critical to maintain a successful training system.

Bibliometric Analysis of the Extracranial-Intracranial Bypass Literature.

OBJECTIVE: Extracranial-intracranial (EC-IC) bypass is a procedure in which a blood vessel outside the skull is connected to one inside the skull to improve cerebral blood flow. Certain aneurysms cannot be treated through standard clipping, and EC-IC bypass may be recommended in such cases. A vast body of literature exists on the use of EC-IC bypass as a treatment for cerebrovascular disorders. While beneficial to surgeons, these publications may not reach all the intended audience, which encourages the use of bibliometric analyses. Although a fraction of historically meaningful publications may not have been sufficiently valued through citation count, bibliometric analysis is the gold standard for assessing the impact of a publication. METHODS: Using bibliometric analysis, we queried the Web of Science database to identify the 50 most impactful publications on EC-IC bypass based on citation count. RESULTS: The literature search retrieved 125 publications that met inclusion criteria, from which the top 50 most-cited ones were selected. The mean number of citations for each article was 117.06 (range 35-1437). Case reports and series constituted 15 (30%) of the top 50 publications on EC-IC bypass, followed by 8 (16%) editorials and 7 (14%) randomized controlled trials. A total of 265 authors in 10 countries contributed to the 50 manuscripts, which were published in 15 different journals. CONCLUSIONS: We retrieved the top 50 most-cited articles on EC-IC bypass surgery and identified the landmark publications to provide a foundational understanding of the procedure as a treatment for complex disorders.

Applying to residency: survey of neurosurgical residency applicants on virtual recruitment during COVID-19.

OBJECTIVE: The COVID-19 pandemic caused a significant disruption to residency recruitment, including a sudden, comprehensive transition to virtual interviews. The authors sought to characterize applicant experiences and perceptions concerning the change in the application, interview, and match process for neurological surgery residency during the 2020-2021 recruitment cycle. METHODS: A national survey of neurosurgical residency applicants from the 2020-2021 application cycle was performed. This survey was developed in cooperation with the Society of Neurological Surgeons (SNS) and the American Association of Neurological Surgeons Young Neurosurgeons Committee (YNC) and sent to all applicants (n = 280) who included academic video submissions to the SNS repository as part of their application package. These 280 applicants accounted for 69.6% of the total 402 neurosurgical applicants this year. RESULTS: Nearly half of the applicants responded to the survey (44.3%, 124 of 280). Applicants favored additional reform of the interview scheduling process, including a centralized scheduling method, a set of standardized release dates for interview invitations, and interview caps for applicants. Less than 8% of students desired a virtual-only platform in the future, though the majority of applicants supported incorporating virtual interviews as part of the process to contain applicant costs and combining them with traditional in-person interview opportunities. Program culture and fit, as well as clinical and research opportunities in subspecialty areas, were the most important factors applicants used to rank programs. However, subjective program "fit" was deemed challenging to assess during virtual-only interviews. CONCLUSIONS: Neurosurgery resident applicants identified standardized interview invitation release dates, centralized interview scheduling methods, caps on the number of interviews available to each candidate, and regulated opportunities for both virtual and in-person recruitment as measures that could significantly improve the applicant experience during and effectiveness of future neurosurgery residency application cycles. Applicants prioritized program culture and "fit" during recruitment, and a majority were open to incorporating virtual elements into future cycles to reduce costs while retaining in-person opportunities to gauge programs and their locations.

Increasing outdoor host-seeking in Anopheles gambiae over 6 years of vector control on Bioko Island.

BACKGROUND: Vector control through indoor residual spraying (IRS) has been employed on Bioko Island, Equatorial Guinea, under the Bioko Island Malaria Control Project (BIMCP) since 2004. This study analyses the change in mosquito abundance, species composition and outdoor host-seeking proportions from 2009 to 2014, after 11 years of vector control on Bioko Island. METHODS: All-night indoor and outdoor human landing catches were performed monthly in the Bioko Island villages of Mongola, Arena Blanca, Biabia and Balboa from 2009 to 2014. Collected mosquitoes were morphologically identified and a subset of Anopheles gambiae sensu lato (s.l.) were later identified molecularly to their sibling species. Mosquito collection rates, species composition and indoor/outdoor host-seeking sites were analysed using generalized linear mixed models to assess changes in mosquito abundance and behaviour. RESULTS: The overall mosquito collection rate declined in each of the four Bioko Island villages. Anopheles coluzzii and Anopheles melas comprised the An. gambiae s.l. mosquito vector population, with a range of species proportions across the four villages. The proportion of outdoor host-seeking An. gambiae s.l. mosquitoes increased significantly in all four villages with an average increase of 58.8 % [57.9, 59.64 %] in 2009 to 70.0 % [67.8, 72.0 %] in 2014. Outdoor host-seeking rates did not increase in the month after an IRS spray round compared to the month before, suggesting that insecticide repellency has little impact on host-seeking behaviour. CONCLUSION: While vector control on Bioko Island has succeeded in substantial reduction in overall vector biting rates, populations of An. coluzzii and An. melas persist. Host-seeking behaviour has changed in these An. gambiae s.l. populations, with a shift towards outdoor host-seeking. During this study period, the proportion of host-seeking An. gambiae s.l. caught outdoors observed on Bioko Island increased to high levels, exceeding 80 % in some locations. It is possible that there may be a genetic basis underlying this large shift in host-seeking behaviour, in which case outdoor feeding could pose a serious threat to current vector control programmes. Currently, the BIMCP is preparing for this potential challenge by testing source reduction as a complementary control effort that also targets outdoor transmission.

Malaria transmission after five years of vector control on Bioko Island, Equatorial Guinea.

BACKGROUND: Malaria is endemic with year-round transmission on Bioko Island. The Bioko Island Malaria Control Project (BIMCP) started in 2004 with the aim to reduce malaria transmission and to ultimately eliminate malaria. While the project has been successful in reducing overall malaria morbidity and mortality, foci of high malaria transmission still persist on the island. Results from the 2009 entomological collections are reported here. METHODS: Human landing collections (HLC) and light trap collections (LTC) were carried out on Bioko Island, Equatorial Guinea in 2009. The HLCs were performed in three locations every second month and LTCs were carried out in 10 locations every second week. Molecular analyses were performed to identify species, detect sporozoites, and identify potential insecticide resistance alleles. RESULTS: The entomological inoculation rates (EIR) on Bioko Island ranged from 163 to 840, with the outdoor EIRs reaching > 900 infective mosquito bites per year. All three human landing collection sites on Bioko Island had an annual EIR exceeding the calculated African average of 121 infective bites per year. The highest recorded EIRs were in Punta Europa in northwestern Bioko Island with human biting rates of 92 and 66 mosquito landings per person per night, outdoors and indoors, respectively. Overall, the propensity for mosquito biting on the island was significantly higher outdoors than indoors (p < 0.001). Both Anopheles gambiae s.s. and An. melas were responsible for malaria transmission on the island, but with different geographical distribution patterns. Sporozoite rates were the highest in An. gambiae s.s. populations ranging from 3.1% in Punta Europa and 5.7% in Riaba in the southeast. Only the L1014F (kdr-west) insecticide resistance mutation was detected on the island with frequencies ranging from 22-88% in An. gambiae s.s. No insecticide resistance alleles were detected in the An. melas populations. CONCLUSIONS: In spite of five years of extensive malaria control and a generalized reduction in the force of transmission, parasite prevalence and child mortality, foci of very high transmission persist on Bioko Island, particularly in the northwestern Punta Europa area. This area is favorable for anopheline mosquito breeding; human biting rates are high, and the EIRs are among the highest ever recorded. Both vector species collected in the study have a propensity to bite outdoors more frequently than indoors. Despite current vector control efforts mosquito densities remain high in such foci of high malaria transmission. To further reduce transmission, indoor residual spraying (IRS) needs to be supplemented with additional vector control interventions.

Limited usefulness of microsatellite markers from the malaria vector Anopheles gambiae when applied to the closely related species Anopheles melas.

Anopheles melas is a brackish water mosquito found in coastal West Africa where it is a dominant malaria vector locally. In order to facilitate genetic studies of this species, 45 microsatellite loci originally developed for Anopheles gambiae were sequenced in An. melas. Those that were suitable based on repeat number and flanking regions were examined in 2 natural populations from Equatorial Guinea. Only 15 loci were eventually deemed suitable as polymorphic markers in An. melas populations. These loci were screened in 4 populations from a wider geographic range. Heterozygosity estimates ranged from 0.18 to 0.79, and 2.5-15 average alleles were observed per locus, yielding 13 highly polymorphic markers and 2 loci with lower variability. To examine the usefulness of microsatellite markers when applied in a sibling species, the original An. gambiae specific markers were used to amplify 5 loci in An. melas. Null alleles were found for 1 An. gambiae marker. We discuss the pitfalls of using microsatellite loci across closely related species and conclude that in addition to the problem of null alleles associated with this practice, many loci may prove to be of very limited use as polymorphic markers even when used in a sibling species.

Light traps fail to estimate reliable malaria mosquito biting rates on Bioko Island, Equatorial Guinea.

BACKGROUND: The human biting rate (HBR), an important parameter for assessing malaria transmission and evaluating vector control interventions, is commonly estimated by human landing collections (HLC). Although intense efforts have been made to find alternative non-exposure mosquito collection methods, HLC remains the standard for providing reliable and consistent HBRs. The aim of this study was to assess the relationship between human landing and light trap collections (LTC), in an attempt to estimate operationally feasible conversion factors between the two. The study was conducted as part of the operational research component of the Bioko Island Malaria Control Project (BIMCP), Equatorial Guinea. METHODS: Malaria mosquitoes were collected indoors and outdoors by HLCs and LTCs in three villages on Bioko Island, Equatorial Guinea during five bimonthly collections in 2009. Indoor light traps were suspended adjacent to occupied long-lasting, insecticide-treated bed nets. Outdoor light traps were placed close to the outer wall under the roof of the collection house. Collected specimens were subjected to DNA extraction and diagnostic PCR to identify species within the Anopheles gambiae complex. Data were analysed by simple regression of log-transformed values and by Bayesian regression analysis. RESULTS: There was a poor correlation between the two collection methods. Results varied by location, venue, month, house, but also by the statistical method used. The more robust Bayesian analyses indicated non-linear relationships and relative sampling efficiencies being density dependent for the indoor collections, implying that straight-forward and simple conversion factors could not be calculated for any of the locations. Outdoor LTC:HLC relationships were weak, but could be estimated at 0.10 and 0.07 for each of two locations. CONCLUSIONS: Light trap collections in combination with bed nets are not recommended as a reliable method to assess human biting rates on Bioko Island. Different statistical analyses methods give variable and inconsistent results. Substantial variation in collection methods prevents the determination of reliable and operationally feasible conversion factors for both indoor and outdoor data. Until improved mosquito collection methods are developed that can provide reliable and unbiased HBR estimates, HLCs should continue to serve as the reference method for HBR estimation.

Outdoor host seeking behaviour of Anopheles gambiae mosquitoes following initiation of malaria vector control on Bioko Island, Equatorial Guinea.

BACKGROUND: Indoor-based anti-vector interventions remain the preferred means of reducing risk of malaria transmission in malaria endemic areas around the world. Despite demonstrated success in reducing human-mosquito interactions, these methods are effective solely against endophilic vectors. It may be that outdoor locations serve as an important venue of host seeking by Anopheles gambiae sensu lato (s.l.) mosquitoes where indoor vector suppression measures are employed. This paper describes the host seeking activity of anopheline mosquito vectors in the Punta Europa region of Bioko Island, Equatorial Guinea. In this area, An. gambiae sensu stricto (s.s.) is the primary malaria vector. The goal of the paper is to evaluate the importance of An gambiae s.l. outdoor host seeking behaviour and discuss its implications for anti-vector interventions. METHODS: The venue and temporal characteristics of host seeking by anopheline vectors in a hyperendemic setting was evaluated using human landing collections conducted inside and outside homes in three villages during both the wet and dry seasons in 2007 and 2008. Additionally, five bi-monthly human landing collections were conducted throughout 2009. Collections were segregated hourly to provide a time distribution of host-seeking behaviour. RESULTS: Surprisingly high levels of outdoor biting by An. gambiae senso stricto and An. melas vectors were observed throughout the night, including during the early evening and morning hours when human hosts are often outdoors. As reported previously, An. gambiae s.s. is the primary malaria vector in the Punta Europa region, where it seeks hosts outdoors at least as much as it does indoors. Further, approximately 40% of An. gambiae s.l. are feeding at times when people are often outdoors, where they are not protected by IRS or LLINs. Repeated sampling over two consecutive dry-wet season cycles indicates that this result is independent of seasonality. CONCLUSIONS: An. gambiae s.l. mosquitoes currently seek hosts in outdoor venues as much as indoors in the Punta Europa region of Bioko Island. This contrasts with an earlier pre-intervention observation of exclusive endophagy of An. gambiae in this region. In light of this finding, it is proposed that the long term indoor application of insecticides may have resulted in an adaptive shift toward outdoor host seeking in An. gambiae s.s. on Bioko Island.