Learning curve and influencing factors of performing microsurgical anastomosis: a laboratory prospective study

Human placenta in vascular neurosurgery training: a comprehensive review of laboratory models, possible exercises, and assessments for skills improvement

INTRODUCTION

Simulation is increasingly recognized as an important tool to enhance neurosurgical education. In this field, especially in neurovascular surgery, human placenta (hPl) is being recognized as a valuable training model because of its abundant availability, ethical acceptance, and analogous vasculature with other vessels of the human body. Nevertheless, although a rising body of literature is witnessing a renovated interest toward this "old" model, to date no comprehensive reviews on the topics are available. Main objective of this paper is to comprehensively review hPl use in neurovascular surgery training, focusing on model preparation, type of possible exercises along with assessment tools which can be used to check for trainees learning.

EVIDENCE ACQUISITION

A systematic review of the pertinent literature was performed, following PRISMA guidelines, searching the following key words in "title/abstract" fields in only English-written works: "placenta and neurosurgery." We focused on preclinical works concerning use of hPl models in neurovascular surgery training. We included studies published in the last 40 years, till December 31st, 2023.

EVIDENCE SYNTHESIS

A total of 950 scientific publications were initially screened, and 23 papers met the inclusion and exclusion criteria. In summary, the chorionic surface of hPl may be used as a neurovascular gym where different exercises can be performed. Placenta models can be produced with or without the use of intravascular dyes and or/pumping systems to resemble a beating-heart vascular system. The three main neurovascular surgical fields where hPl is being considered to be highly simulative are: 1) Sylvian fissure dissection; 2) aneurysm dissection and clipping; 3) bypass training. Considering the simulative purpose, face, content and construct validify of hPl model have been tested and verified by many authors, although still few data are available regarding transfer/predictive validity.

CONCLUSIONS

This systematic review highlighted the easiness of preparation and availability along with the strong didactical meaning that the use of hPl-based models may have in the field of neurovascular surgery training. In view of current progressive lowering of surgical vascular cases and increasing technical demand related to their management, further studies aimed to assess if this simulator could be able to produce a learning effect and improve performance with continued use are strongly needed.

Effect of Sleep Deprivation on Simulated Microsurgical Vascular Anastomosis

BACKGROUND

 The effects of sleep deprivation on surgical performance have been well documented. However, reports on the effects of sleep deprivation on microneurosurgery are limited. This study aimed to investigate the effects of sleep deprivation on microneurosurgery.

METHODS

 Ten neurosurgeons participated in the anastomosis of a vessel model using a microscope in sleep-deprived and normal states. We evaluated the procedure time (PT), stitch time (ST), interval time (IT), number of unachieved movements (NUM), leak rate, and practical scale for anastomosis quality assessment. Each parameter was compared between normal and sleep-deprived states. Subanalyses were performed on the two groups based on PT and NUM under the normal state (proficient and nonproficient groups).

RESULTS

 Although no significant differences were noted in PT, ST, NUM, leak rate, or practical scale, IT was significantly prolonged under sleep deprivation compared with the normal state (mean: 258.8 ± 94.0 vs. 199.3 ± 74.9 seconds; p = 0.02). IT was significantly prolonged under sleep deprivation in the nonproficient group based on both PT and NUM (PT: 234.2 ± 71.6 vs. 321.2 ± 44.7 seconds, p = 0.04; NUM: 173.3 ± 73.6 vs. 218.7 ± 97.7; p = 0.02), whereas no significant difference was observed in the proficient group (PT: 147.0 ± 47.0 vs. 165.3 ± 61.1 seconds, p = 0.25; NUM: 173.3 ± 73.6 vs. 218.7 ± 97.7; p = 0.25).

CONCLUSIONS

 Although IT was significantly prolonged under sleep deprivation in the nonproficient group, there was no decline in performance skills in either the proficient or nonproficient group. The effect of sleep deprivation may require caution in the nonproficient group, but it is possible that certain microneurosurgical outcomes can be achieved under sleep deprivation.

Defining the Learning Curve of the Exoscope in Spine Surgery

INTRODUCTION

In recent years, introduction of the exoscope system has been responsible for a new era of optics in surgery. Such a system has started to be widely used in neurosurgery. More recently, the exoscope has also been increasingly used for spinal procedures. Thus, we aimed to explore the potential for exoscope-assisted spinal procedures and define the advantages and drawbacks of implementing the system into our daily routine.

METHODS

To achieve the aim of the study, we retrospectively reviewed the case series of patients treated by a senior surgeon and analyzed the results, complications, and operative time. The operating times were compared between the exoscope-assisted procedures and microscope-assisted procedures.

RESULTS

A total of 24 spinal procedure were performed with the exoscope in a 2-month period. In this first patient series performed by a single surgeon without experience with the exoscope, the learning curve seemed to be relatively low, with mastery of the instrument achieved after the performance of only a few cases. Comparing the cases after the plateau of the learning curve had been reached with those performed during the still active phase of the learning curve, a significant difference was found in the operative times. No statistically significant difference was detected in terms of blood loss or intraoperative complications.

CONCLUSIONS

Based on our first experience, use of the exoscope shows promising potential for opening up new frontiers in spinal microsurgery. In addition, it has a low learning curve for experienced surgeons.

Accuracy Analysis of Computer-Assisted and Guided Dental Implantology by Comparing 3D Planning Data and Actual Implant Placement in a Mandibular Training Model: A Monocentric Comparison between Dental Students and Trained Implantologists

The aim of this study was to investigate how precisely implantation can be realized by participants on a phantom head according to preliminary planning. Of particular interest here was the influence of participants' previous knowledge and surgical experience on the precision of the implant placement. The placed implants were scanned using an intraoral scanner, saved as STL files, and superimposed with the 3D-planned implant placement. Deviations from the planning were indicated in millimeters and degrees. We were able to show that on average, the deviations from computer-assisted 3D planning were less than 1 mm for implantologists, and the students also did not deviate more than 1.78 mm on average from 3D planning. This study shows that guided implantology provides predictable and reproducible results in dental implantology. Incorrect positioning, injuries to anatomical structures, and implant positions that cannot be prosthetically restored can thus be avoided.

3D Exoscopes in Experimental Microanastomosis: A Comparison of Different Systems

Background: In recent years, three-dimensional exoscopes have been increasingly applied in neurosurgery. Multiple exoscopic systems are available, all offering specific features. In this study, we assessed practical and visualization performance of four different exoscopic systems in a highly challenging microsurgical procedure, and evaluated whether these affected the quality of work. Methods: We included four different exoscopes: Olympus ORBEYE, Zeiss KINEVO, Storz VITOM, and Aesculap AEOS. With each exoscope, ten experimental bypass procedures were carried out on chicken wing vessels at a depth of 3 cm. We evaluated the quality of the anastomoses, the practical considerations for the setup of the exoscopic systems, and the visualization quality by tracking the number of unnecessary movements. Results: All included exoscopes enabled us to perform the bypass procedures with mostly adequate or excellent results. Surgically, the most pronounced difference between the exoscopes was the duration of the procedure, which was mainly due to the number of unnecessary movements. Practically, the exoscopes differ highly which is important when considering which exoscope to apply. Conclusions: This is the first study comparing different exoscope systems while performing the same challenging microsurgical procedure. We found major practical differences between the exoscopes that determine the suitability of an exoscope based on the demands and conditions of the surgical procedure. Therefore, preprocedural practical training with the exoscope is required.