Developing microsurgical milestones for psychomotor skills in neurological surgery residents as an adjunct to operative training: the home microsurgery laboratory

When microsurgery becomes the only lifesaving resource: An institutional experience treating patients from low-income backgrounds affected by posterior circulation brain aneurysms

BACKGROUND AND OBJECTIVE

Aneurysms of the posterior cerebral circulation constitute a burdensome condition with high mortality and morbidity. In the modern era, there has been a trend toward favoring an endovascular approach over microsurgery for aneurysm cases. Nevertheless, this transition has yet to be mirrored in low-to-middle-income countries where endovascular therapy may not be widely available. Herein, we aim to illustrate our experience treating these challenging conditions in patients from low-income backgrounds and discuss the relevance of the clinical setting in the treatment decision.

METHODS

The authors conducted a retrospective review of the health records of patients who received microsurgical treatment for aneurysms in the posterior circulation, including the basilar artery (BA), posterior cerebral artery (PCA), and posterior inferior cerebellar artery (PICA) in an institution providing treatment to people of low-income backgrounds. Epidemiological data, microsurgical technique, and neurological function were retrieved and analyzed.

RESULTS

Surgical clipping was employed for 12 patients (75% female) harboring 15 aneurysms (87% in the posterior circulation and 62% ruptured at presentation). Aneurysms were predominately located in the BA (69%), followed by the PCA (15%) and PICA (15%). Among neurological complications, 25% of patients developed oculomotor nerve palsy. The mortality rate was 17% owing to complications such as cerebral vasospasm, infarction, and severe intracranial hypertension. At the 6-month follow-up, 90% of patients had a good clinical outcome (modified Rankin scale scores of 0-2).

CONCLUSION

The present case series illustrates the manifest role of microsurgical techniques for posterior circulation aneurysms, particularly in a scenario where endovascular techniques are not easily accessible. Importantly, this clinical setting pressure could exhort trainees to strive for microsurgical mastery and gain a competitive advantage.

Current Indications, Trends, and Long-Term Results of 233 Bypasses to Treat Complex Intracranial Aneurysms: A Location-Specific Analysis

BACKGROUND AND OBJECTIVES

Advances in endovascular flow diverters have led to a secular shift in the management of brain aneurysms, causing debate on current bypass indications. We therefore sought to investigate the long-term results, current indications, and trends of bypasses for brain aneurysms.

METHODS

We retrospectively reviewed bypasses performed between 2005 and 2022 to treat brain aneurysms. Demographic, clinical, and radiological data were collected till the most recent follow-up. Aneurysm occlusion and graft patency was noted on cerebral angiogram in the immediate postoperative, 3-month, and most recent follow-up periods. Clinical outcomes (modified Rankin scores) and complications were assessed at 3 month and most recent follow-up. Trends in bypass volume and graft patency were assessed in 5-year epochs. Results were dichotomized based on aneurysm location to generate location-specific results and trends.

RESULTS

Overall, 203 patients (mean age 50 years, 57% female patients) with 207 cerebral aneurysms were treated with 233 cerebral bypasses with a mean follow-up of 2 years. Fusiform morphology was the most common bypass indication. Aneurysm occlusion on immediate postoperative and final follow-up angiogram was 89% (184/207) and 96% (198/207), respectively. Graft patency rate in the immediate postoperative period and most recent follow-up was 95% (222/233) and 92% (215/233), respectively. Of 207 aneurysms, 5 (2%) recurred. Of 203 patients, 81% (165) patients had modified Rankin scores of 0-2 at the 3-month follow-up and 11 patients died (mortality 5%). Although there was a steady decrease in the bypass volume over the study period, the proportion of bypasses for recurrent aneurysms increased serially. Posterior circulation aneurysms had lower rates of aneurysm occlusion and significantly higher incidence of postoperative strokes and deaths (P = .0035), with basilar artery aneurysms having the worst outcomes.

CONCLUSION

Bypass indications have evolved with the inception of novel flow diverters. However, they remain relevant in the cerebrovascular surgeon's armamentarium, and long-term results are excellent.

Training in microvascular anastomosis - A randomized comparative study between chicken thigh specimen and live rat

Training in microsurgical techniques on live rats is the gold standard, but raises ethical issues related to animal welfare and cost. The aim of this study was to compare acquisition of microsurgical techniques with primary training on chicken thigh specimens. Seventy six students were randomly assigned: 23 to exclusive rat training and 53 to primary chicken-leg training. Both groups were then evaluated on aortic suture and jugular aortic bypass surgery in live rats. The primary criterion for successful anastomosis was the patency test. The survival of the rat, the number of severe vascular wounds and the quality of the dissection were also assessed. Aortic anastomoses were of significantly better quality in the chicken group (p = 0.041). There was no significant difference in the number of serious injuries, rat mortality, or quality of dissection (p > 0.05). For jugular aortic bypass surgery, dissection quality (p = 0.02) and patency test (p = 0.05) were better in the chicken-leg group. There was no significant difference in number of severe wounds or rat mortality (p > 0.05). Students who started their microsurgical training on a chicken leg did not perform worse than those with exclusive live rat training. Initial training on chicken thigh specimens seems to be a reliable alternative to training on live models. LEVEL OF EVIDENCE: Level II - Randomized controlled trial.

Construct validity of the Surgical Autonomy Program for the training of neurosurgical residents

OBJECTIVE

There is no standard way in which physicians teach or evaluate surgical residents intraoperatively, and residents are proving to not be fully competent at core surgical procedures upon graduating. The Surgical Autonomy Program (SAP) is a novel educational model that combines a modified version of the Zwisch scale with Vygotsky’s social learning theory. The objective of this study was to establish preliminary validity evidence that SAP is a reliable measure of autonomy and a useful tool for tracking competency over time.

METHODS

The SAP breaks each surgical case into 4 parts, or zones of proximal development (ZPDs). Residents are evaluated on a 4-tier autonomy scale (TAGS scale) for each ZPD in every surgical case. Attendings were provided with a teaching session about SAP and identified appropriate ZPDs for surgical cases under their area of expertise. All neurosurgery residents at Duke University Hospital from July 2017 to July 2021 participated in this study. Chi-square tests and ordinal logistic regression were used for the analyses.

RESULTS

Between 2017 and 2021, there were 4885 cases logged by 27 residents. There were 30 attendings who evaluated residents using SAP. Faculty completed evaluations on 91% of cases. The ZPD of focus directly correlated with year of residency (postgraduate year) (χ2 = 1221.1, df = 15, p < 0.001). The autonomy level increased with year of residency (χ2 = 3553.5, df = 15, p < 0.001). An ordinal regression analysis showed that for every year increase in postgraduate year, the odds of operating at a higher level of independence was 2.16 times greater (95% CI 2.11–2.21, p < 0.001). The odds of residents performing with greater autonomy was lowest for the most complex portion of the case (ZPD3) (OR 0.18, 95% CI 0.17–0.20, p < 0.001). Residents have less autonomy with increased case complexity (χ2 = 160.28, df = 6, p < 0.001). Compared with average cases, residents were more likely to operate with greater autonomy on easy cases (OR 1.44, 95% CI 1.29–1.61, p < 0.001) and less likely to do so on difficult cases (OR 0.72, 95% CI 0.67–0.77, p < 0.001).

CONCLUSIONS

This study demonstrates preliminary evidence supporting the construct validity of the SAP. This tool successfully tracks resident autonomy and progress over time. The authors’ smartphone application was widely used among surgical faculty and residents, supporting integration into the perioperative workflow. Wide implementation of SAP across multiple surgical centers will aid in the movement toward a competency-based residency education system.

Computer vision coaching microsurgical laboratory training: PRIME (Proficiency Index in Microsurgical Education) proof of concept

Computer vision (CV) feedback could be aimed as a constant tutor to guide ones proficiency during microsurgical practice in controlled environments. Five neurosurgeons with different levels of microsurgical expertise performed simulated vessel dissection and micro-suture in an ex vivo model for posterior computer analysis of recorded videos. A computer program called PRIME (Proficiency Index of Microsurgical Education) used in this research recognized color-labeled surgical instruments, from downloading videos into a platform, with a range of motion greater than 3 mm, for objective evaluation of number of right and left hand movements. A proficiency index of 0 to 1 was pre-established in order to evaluate continuous training improvement. PRIME computer program captured all hand movements executed by participants, except for small tremors or inconsistencies that have a range of motion inferior to 3 mm. Number of left and right hand movements were graphically expressed in order to guide more objective and efficacious training for each trainee, without requiring body sensors and cameras around the operating table. Participants with previous microsurgical experience showed improvement from 0.2 to 0.6 (p < 0.05), while novices had no improvement. Proficiency index set by CV was suggested, in a self-challenge and self-coaching manner. PRIME would offer the capability of constant laboratory microsurgical practice feedback under CV guidance, opening a new window for oriented training without a tutor or specific apparatus regarding all levels of microsurgical proficiency. Prospective, large data study is needed to confirm this hypothesis.

A state-of-the-art review of the fabrication and characteristics of titanium and its alloys for biomedical applications

Abstract

Commercially pure titanium and titanium alloys have been among the most commonly used materials for biomedical applications since the 1950s. Due to the excellent mechanical tribological properties, corrosion resistance, biocompatibility, and antibacterial properties of titanium, it is getting much attention as a biomaterial for implants. Furthermore, titanium promotes osseointegration without any additional adhesives by physically bonding with the living bone at the implant site. These properties are crucial for producing high-strength metallic alloys for biomedical applications. Titanium alloys are manufactured into the three types of α, β, and α + β. The scientific and clinical understanding of titanium and its potential applications, especially in the biomedical field, are still in the early stages. This review aims to establish a credible platform for the current and future roles of titanium in biomedicine. We first explore the developmental history of titanium. Then, we review the recent advancement of the utility of titanium in diverse biomedical areas, its functional properties, mechanisms of biocompatibility, host tissue responses, and various relevant antimicrobial strategies. Future research will be directed toward advanced manufacturing technologies, such as powder-based additive manufacturing, electron beam melting and laser melting deposition, as well as analyzing the effects of alloying elements on the biocompatibility, corrosion resistance, and mechanical properties of titanium. Moreover, the role of titania nanotubes in regenerative medicine and nanomedicine applications, such as localized drug delivery system, immunomodulatory agents, antibacterial agents, and hemocompatibility, is investigated, and the paper concludes with the future outlook of titanium alloys as biomaterials.

Graphic abstract

Early Effects of COVID-19 Pandemic on Neurosurgical Training in the United States: A Case Volume Analysis of 8 Programs

OBJECTIVE

To determine the impact of the 2019 novel coronavirus disease (COVID-19) pandemic on operative case volume in 8 U.S. neurosurgical residency training programs in early 2020 and to survey these programs regarding training activities during this period.

METHODS

A retrospective review was conducted of monthly operative case volumes and types for 8 residency programs for 2019 and January through April 2020. Cases were grouped as elective cranial, elective spine, and nonelective emergent cases. Programs were surveyed regarding residents' perceptions of the impact of COVID-19 on surgical training, didactics, and research participation. Data were analyzed for individual programs and pooled across programs.

RESULTS

Across programs, the 2019 monthly mean ± SD case volume was 211 ± 82; 2020 mean ± SD case volumes for January, February, March, and April were 228 ± 93, 214 ± 84, 180 ± 73, and 107 ± 45. Compared with 2019, March and April 2020 mean cases declined 15% (P = 0.003) and 49% (P = 0.002), respectively. COVID-19 affected surgical case volume for all programs; 75% reported didactics negatively affected, and 90% reported COVID-19 resulted in increased research time. Several neurosurgery residents required COVID-19 testing; however, to our knowledge, only 1 resident from the participating programs tested positive.

CONCLUSIONS

This study documents a significant reduction in operative volume in 8 neurosurgery residency training programs in early 2020. During this time, neurosurgery residents engaged in online didactics and research-related activities, reporting increased research productivity. Residency programs should collect data to determine the educational impact of the COVID-19 pandemic on residents' operative case volumes, identify deficiencies, and develop plans to mitigate any effects.

The Future of Skull Base Surgery: A View Through Tinted Glasses

In the present report, we have broadly outlined the potential advances in the field of skull base surgery, which might occur within the next 20 years based on the many areas of current research in biology and technology. Many of these advances will also be broadly applicable to other areas of neurosurgery. We have grounded our predictions for future developments in an exploration of what patients and surgeons most desire as outcomes for care. We next examined the recent developments in the field and outlined several promising areas of future improvement in skull base surgery, per se, as well as identifying the new hospital support systems needed to accommodate these changes. These include, but are not limited to, advances in imaging, Raman spectroscopy and microscopy, 3-dimensional printing and rapid prototyping, master-slave and semiautonomous robots, artificial intelligence applications in all areas of medicine, telemedicine, and green technologies in hospitals. In addition, we have reviewed the therapeutic approaches using nanotechnology, genetic engineering, antitumor antibodies, and stem cell technologies to repair damage caused by traumatic injuries, tumors, and iatrogenic injuries to the brain and cranial nerves. Additionally, we have discussed the training requirements for future skull base surgeons and stressed the need for adaptability and change. However, the essential requirements for skull base surgeons will remain unchanged, including knowledge, attention to detail, technical skill, innovation, judgment, and compassion. We believe that active involvement in these rapidly evolving technologies will enable us to shape some of the future of our discipline to address the needs of both patients and our profession.