Validation of microsurgical models in microsurgery training and competence: A review

Nonliving versus Living Animal Models for Microvascular Surgery Training: A Randomized Comparative Study

BACKGROUND

Ethical and financial considerations have encouraged the use of nonliving models for simulation-based training in microsurgery, such as commercially available chicken thighs. The purpose of this study was to compare the nonliving chicken thigh model to the one currently considered as the standard-namely, the living rat model-in the setting of an initiation microsurgery course.

METHODS

Applicants to the 3-day basic microsurgery course of the Paris School of Surgery were assigned randomly to either one group that received the regular training of the school (RT group), including four hands-on sessions using only living rat models, or one group that received a modified curriculum in which a nonliving chicken thigh model was used for the first hands-on session (CT group). During the following session, all trainees were evaluated on living rat models, using a global rating scale and two task-specific scales (knot-tying and anastomosis); rates of anastomosis patency, animal survival, and technique completion were recorded.

RESULTS

Ninety-three residents were enrolled. Global rating scale, knot-tying, and anastomosis task-specific scale scores were significantly higher in the CT group ( n = 51) than in the RT group, with mean differences of 2.6 points ( P = 0.0001), 1.3 points ( P < 0.0001), and 1.4 points ( P < 0.0001), respectively. Patency and survival rates were significantly higher in the CT group than in the RT group, with mean differences of 22% ( P = 0.0020) and 27% ( P < 0.0001), respectively; completion rates were not statistically different.

CONCLUSION

Subject to the use of validated models, such as the chicken thigh, nonliving animal models are a suitable alternative to the living rat model in microsurgery initial training.

CLINICAL RELEVANCE STATEMENT

The use of validated non-living models, such as the chicken thigh, is a suitable alternative to the living rat model in microsurgery initial training.

Impact of High-Fidelity Microvascular Surgery Simulation on Resident Training

BACKGROUND

 Microsurgery requires a high level of skill achieved only through repeated practice. With duty-hour restrictions and supervision requirements, trainees require more opportunities for practice outside the operating room. Studies show simulation training improves knowledge and skills. While numerous microvascular simulation models exist, virtually all lack the combination of human tissue and pulsatile flow.

METHODS

 The authors utilized a novel simulation platform incorporating cryopreserved human vein and a pulsatile flow circuit for microsurgery training at two academic centers. Subjects performed a standardized simulated microvascular anastomosis and repeated this task at subsequent training sessions. Each session was evaluated using pre- and postsimulation surveys, standardized assessment forms, and the time required to complete each anastomosis. Outcomes of interest include change in self-reported confidence scores, skill assessment scores, and time to complete the task.

RESULTS

 In total, 36 simulation sessions were recorded including 21 first attempts and 15 second attempts. Pre- and postsimulation survey data across multiple attempts demonstrated a statistically significant increase in self-reported confidence scores. Time to complete the simulation and skill assessment scores improved with multiple attempts; however, these findings were not statistically significant. Subjects unanimously reported on postsimulation surveys that the simulation was beneficial in improving their skills and confidence.

CONCLUSION

 The combination of human tissue and pulsatile flow results in a simulation experience that approaches the level of realism achieved with live animal models. This allows plastic surgery residents to improve microsurgical skills and increase confidence without the need for expensive animal laboratories or any undue risk to patients.

Topographical Systematization of Human Placenta Model for Training in Microneurosurgery

BACKGROUND

Neurosurgical training continuously seeks innovative methods to enhance the acquisition of essential technical skills for neurosurgeons worldwide. While various training models have been employed, few truly replicate real-life conditions optimally. Human placenta is a good model for neurosurgical microsurgery training due to its anatomic similarities to neurovascular structures. Placental vessels exhibit a branching pattern and caliber comparable with intracranial vessels, making them suitable for practicing microsurgical techniques. The study aims to delineate the anatomic zones of the placenta and propose a segmented training model, resulting in a reproducible, cost-effective, and realistic neurosurgical microsurgery training environment.

METHODS

Twenty human placentas were meticulously prepared, injected with dyes, and categorized into zones on the basis of anatomic features. Measurements of placental vessels were recorded and compared with cerebral vessels. The placenta was divided into 4 quadrants to facilitate specific training techniques.

RESULTS

Our results revealed varying vessel diameters across placental zones, closely resembling cerebral vessels. Different microsurgical techniques were applied to specific placental zones, thereby optimizing training scenarios. The applicability section described exercises such as membrane dissection, vessel skeletonization, aneurysm creation, vascular bypass, and tumor dissection within the placental model, providing detailed guidance on the zones suitable for each exercise.

CONCLUSIONS

Human placenta serves as an effective microsurgical training model for neurosurgery, enhancing neurosurgeons' skills through anatomic segmentation. Integrating this model into training programs can significantly contribute to skill acquisition and improved surgical outcomes. Further research is warranted to refine and expand its utilization, complemented by clinical experiences and other simulation tools.

Validation of Two Novel and Complementary Training Platforms for Small Joint Arthroscopy

PURPOSE

We developed 2 complementary low-fidelity models to be used to create the tool skills needed to perform small joint arthroscopy. The purpose of the study was to establish the face and construct validity of the 2 models.

METHODS

The "foundation model" was constructed from lemon and radish sections, and the "advanced model" was constructed from a chicken knee. Using both models, novice, intermediate, and experienced participants were asked to perform specific tasks and were timed and scored on their performance. The experienced surgeons were given a 16-item survey to rate how closely each model emulated reality to determine face validity.

RESULTS

For the foundation model, the mean total time for the completion of tasks was 1,138 seconds for novices, 1,059 seconds for intermediates, and 631 seconds for experienced, with significant differences between the groups for time to complete 2 of the tasks. With a maximum possible score of 50 points for the correct performance of all tasks, the mean total performance score was 23 for novices, 31.8 for intermediates, and 42.2 for experienced operators. For the advanced model, the mean total time for completion was 266 seconds for novices, 147 seconds for intermediates, and 72 seconds for experienced participants. With a maximum possible score of 31 points for the correct performance of all tasks, the mean total performance score was 1.9 for novices, 15.0 for intermediates, and 24.3 for experienced participants. The average scores for the face validity surveys using a 5-point Likert scale were 4.2 and 4.5 of 5 possible points for the foundation and advanced models, respectively.

CONCLUSIONS

Experienced operators completed the tasks more quickly and had higher performance scores than the operators in other groups. This correlation between experience and performance suggests that both models have construct validity. The face validity scores were on the upper end of the scale, suggesting that both models emulate reality for experienced operators.

CLINICAL RELEVANCE

These novel models provide low-cost, available and valid simulations conducive to high-repetition training.

The LazyBox Educational Intervention Trial: Can Longitudinal Practice on a Low-Fidelity Microsurgery Simulator Improve Microsurgical Skills?

Introduction Every surgical trainee must acquire microsurgical skills within a limited timeframe. Therefore, identifying effective educational strategies to help learners attain these skills is crucial. Objective Establish the effectiveness of a low-fidelity microsurgery simulator to improve the execution and one's perception of the difficulty of basic surgical techniques. Methods From 2021 to 2022, 24 medical students were randomized to either (1) a treatment group (n=12) that engaged in longitudinal practice on a low-fidelity microsurgery simulator (the LazyBox) or (2) a control group (n=12) that did not practice. Students performed vessel loop ligation, catheter macroanastomosis, and synthetic vessel microanastomosis prior to and six weeks after intervention. Both objective metrics and subjective metrics (Swedish Occupational Fatigue Inventory (SOFI) and Surgery Task Load Index (SURG-TLX)) were obtained. Results The treatment and control arms had 1.2 (SD = 2.6) and 2.1 (SD = 2.4) points increase in the vessel loop ligation, respectively (p = 0.39). The treatment and control arms had a 3.4 (SD = 4.1) and 2.9 (SD = 3.6) points increase in the macroanastomosis task, respectively (p = 0.74). In the synthetic vessel microanastomosis task training, the experimental and control arms showed a 5.4 (SD = 8.3) and a 2.9 (SD = 5.6) points increase, respectively (p = 0.30). No differences were found between the groups regarding survey metrics of mental (p = 0.82), temporal (p = 0.23), and physical demands (p = 0.48). Conclusion In our randomized educational intervention, we found no significant difference in objective and subjective metrics of microsurgical task performance between learners who did and did not use the LazyBox simulator.

Two-Stage Pulsatile Human Placenta Model for Microvascular Anastomosis Training in Neurosurgery

OBJECTIVE

The development of microsurgical skills is crucial for neurosurgical education. The human placenta is a promising model for practicing vascular anastomosis due to its similarities with brain vessels. We propose a 2-stage model for training in extracranial-to-intracranial anastomosis using the placenta.

METHODS

Initially, we propose practicing anastomosis in 2 adjacent placentas. Once successful, the procedure advances to a more challenging configuration that employs a 3-dimensionally printed skull with a window simulating a pterional craniotomy. It is positioned an intracranial placenta and an extracranial one, and the latter has a prominent vessel exposed toward the side of the craniotomy. Both placentas have one artery and vein cannulated in the umbilical cord, and we present an artificial placental circulation system for microvascular training that regulates pulsation and hydrodynamic pressure while keeping veins engorged with a pressurized bag. To verify anastomosis patency, we utilize sodium fluorescein and iodine contrast.

RESULTS

The 2-stage model simulated several aspects of microvascular anastomosis. Our perfusion system allowed for intraoperative adjustments of hydrodynamic pressure and pulsation. Using iodine contrast and fluorescein enabled proper evaluation of anastomosis patency and hydrodynamic features.

CONCLUSIONS

Training in the laboratory is essential for developing microsurgical skills. We have presented a model for microvascular anastomosis with artificial circulation and postoperative imaging evaluation, which is highly beneficial for enhancing the learning curve in microvascular procedures.

Blue-Blood Pig Thorax Model Increases Residents' Confidence in Internal Mammary Dissection

BACKGROUND

 Preparation of the recipient vessels is a crucial step in autologous breast reconstruction, with limited opportunity for resident training intraoperatively. The Blue-Blood-infused porcine chest wall-a cadaveric pig thorax embedded in a mannequin shell, connected to a saline perfusion system-is a novel, cost-effective ($55) simulator of internal mammary artery (IMA) dissection and anastomosis intended to improve resident's comfort, safety, and expertise with all steps of this procedure. The purpose of this study was to assess the effect of the use of this chest wall model on resident's confidence in performing dissection and anastomosis of the IMA, as well as obtain resident's and faculty's perspectives on model realism and utility.

METHODS

 Plastic surgery residents and microsurgery faculty at the University of Wisconsin were invited to participate. One expert microsurgeon led individual training sessions and performed as the microsurgical assistant. Participants anonymously completed surveys prior to and immediately following their training session to assess their change in confidence performing the procedure, as well as their perception of model realism and utility as a formal microsurgical training tool on a five-point scale.

RESULTS

 Every participant saw improvement in confidence after their training session in a minimum of one of seven key procedural steps identified. Of participants who had experience with this procedure in humans, the majority rated model anatomy and performance of key procedural steps as "very" or "extremely" realistic as compared with humans. 100% of participants believed practice with this model would improve residents' ability to perform this operation in the operating room and 100% of participants would recommend this model be incorporated into the microsurgical training curriculum.

CONCLUSION

 The Blue-Blood porcine chest wall simulator increases trainee confidence in performing key steps of IMA dissection and anastomosis and is perceived as valuable to residents and faculty alike.

Evaluation of a Full-Time Microsurgeon Educator on Resident Training, Research Collaboration, and Grant Funding

BACKGROUND

 The value of a fully trained microsurgeon dedicated to a laboratory setting at an academic institution is largely unknown. Microsurgery training lacks a national standard despite its highly complicated nature. Our study aims to evaluate the impact of a single laboratory-dedicated microsurgeon on the microsurgical training of integrated plastic surgery residents and collaborative efforts in research.

METHOD

 We devised a three-faceted microsurgical training curriculum, including a collaborative multi-institutional microsurgery course, novel high-fidelity simulator models, and a dedicated microsurgeon. We cataloged grant funding achieved through support to other divisions' protocols. Time, in hours, spent on training and the number of anastomoses completed with the microsurgical educator in a laboratory setting over a 4-year period (2017-2021) were evaluated. Resident independence scores were collected from attending microsurgeons to quantify the translation of microsurgical training.

RESULTS

 Purchasing and maintenance costs of rats in our rodent facility decreased by $16,533.60 as 198 rats were replaced by our models. The residents who participated in our novel microsurgical training program were able to independently perform anastomoses in the OR by their postgraduate year 6. Additionally, the surgical support offered by our laboratory-dedicated microsurgeon led to a total of $24,171,921 in grant funding between 2017 and 2020.

CONCLUSION

 Hiring an expert microsurgical educator to train residents in a laboratory has proved promising in accelerating microsurgical mastery. Novel training modules, alternatives to animal models, save resources in housing and animal costs. The addition of a research-oriented-microsurgeon has improved collaborative efforts to advance a range of surgical fields.

Validation of a simplified evaluation grid applied to the microsurgery on inert material via smartphone

OBJECTIVES

Microsurgery is usually performed in experimental research models and clinical surgery. It requires meticulous technical skills and continuous training. Inert materials such as Shirataki noodles are readily available and low-cost consumables regularly used for practice. The objective of this study was to evaluate the repeatability and reproducibility of a simplified evaluation grid of suture on inert material (Shirataki Konnyaku noodle) under smartphone magnification.

MATERIAL AND METHODS

Ten students performed end-to-end suture on inert material with magnification via their smartphone. Each suture was filmed, and the videos were randomized. Each student was evaluated on each video three times over three consecutive days, using a simplified evaluation grid. Intra- and inter-observer agreement was evaluated on Concordance Correlation Coefficients. Values were assessed on Pearson's correlation coefficient.

RESULTS

Intra-observer correlation was weak for 2 items (0.288 and 0.246) and moderate for the other 2 (0.419 and 0.529). Inter-observer correlation was weak for 3 items (0.344, 0.358, and 0.276) and close to zero for the other (0.034).

CONCLUSION

This simplified evaluation grid for microsurgery training on inert material via smartphone was poorly repeatable and reproducible. Loss of certain items in the grid due to the use of inert material probably impaired relevance.

Fundamentals of Microsurgery: A Novel Simulation Curriculum Based on Validated Laparoscopic Education Approaches

BACKGROUND

 Microsurgical techniques have a steep learning curve. We adapted validated surgical approaches to develop a novel, competency-based microsurgical simulation curriculum called Fundamentals of Microsurgery (FMS). The purpose of this study is to present our experience with FMS and quantify the effect of the curriculum on resident performance in the operating room.

METHODS

 Trainees underwent the FMS curriculum requiring task progression: (1) rubber band transfer, (2) coupler tine grasping, (3) glove laceration repair, (4) synthetic vessel anastomosis, and (5) vessel anastomosis in a deep cavity. Resident anastomoses were also evaluated in the operative room with the Stanford Microsurgery and Resident Training (SMaRT) tool to evaluate technical performance. The National Aeronautics and Space Administration Task Load Index (NASA-TLX) and Short-Form Spielberger State-Trait Anxiety Inventory (STAI-6) quantified learner anxiety and workload.

RESULTS

 A total of 62 anastomoses were performed by residents in the operating room during patient care. Higher FMS task completion showed an increased mean SMaRT score (p = 0.05), and a lower mean STAI-6 score (performance anxiety) (p = 0.03). Regression analysis demonstrated residents with higher SMaRT score had lower NASA-TLX score (mental workload) (p < 0.01) and STAI-6 scores (p < 0.01).

CONCLUSION

 A novel microsurgical simulation program FMS was implemented. We found progression of trainees through the program translated to better technique (higher SMaRT scores) in the operating room and lower performance anxiety on STAI-6 surveys. This suggests that the FMS curriculum improves proficiency in basic microsurgical skills, reduces trainee mental workload, anxiety, and improves intraoperative clinical proficiency.

Microsurgical Needle Retention Does Not Cause Pain or Neurovascular Injury in a Rat Model

Approximately 20% of retained foreign bodies are surgical needles. Retained macro-needles may become symptomatic, but the effect of microsurgical needles is uncertain. We present the first animal model to simulate microsurgical needle retention. Given a lack of reported adverse outcomes associated with macro-needles and a smaller cutting area of microsurgical needles, we hypothesized that microsurgical needles in rats would not cause changes in health or neurovascular compromise.

Methods

Male Sprague-Dawley rats (x̄ weight: 288.9 g) were implanted with a single, 9.0 needle (n = 8) or 8.0 needle (n = 8) orthogonal to the right femoral vessels and sutured in place. A control group (n = 8) underwent sham surgery. Weekly, a cumulative health score evaluating body weight, body condition score, physical appearance, and behavior for each rat was determined. Infrared thermography (°C, FLIR one) of each hindlimb and the difference was obtained on postoperative days 15, 30, 60, and 90. On day 90, animals were euthanatized, hindlimbs were imaged via fluoroscopy, and needles were explanted.

Results

The mean, cumulative health score for all cohorts at each weekly timepoint was 0. The mean temperature difference was not significantly different on postoperative days 15 (P = 0.54), 30 (P = 0.97), 60 (P = 0.29), or 90 (P = 0.09). In seven of eight rats, 8.0 needles were recovered and visualized on fluoroscopy. In six of eight rats, 9.0 needles were recovered, but 0/8 needles were visualized on fluoroscopy.

Conclusions

Microsurgical needle retention near neurovascular structures may be benign, and imaging for needles smaller than 8.0 may be futile. Further studies should explore microsurgical needle retention potentially through larger animal models.

Comparison of a high-definition three-dimensional digital camera system with a conventional state-of-the-art operation microscope for microsurgical anastomoses

Since its clinical implementation, microvascular surgery has depended on the continuous improvement of magnification tools. One of the more recent developments is a high-definition three-dimensional (3D) digital system (exoscope), which provides an alternative to the state-of-the-art operating microscopes. This study aimed to evaluate the advantages and disadvantages of this technology and compare it with its predecessor. The study included 14 surgeons with varying levels of experience, none of which had used a 3D optical system previously. Six of these surgeons performed five arterial and five venous anastomoses in the chicken thigh model with both the VITOM 3D exoscope-guided system and the Pentero operating microscope. These anastomoses were then evaluated for their quality and anastomosis time. The participants and the other eight surgeons, who had used the digital 3D camera system for microsurgical training exercises and vascular sutures, answered a questionnaire. The anastomosis time and number of complications were lower with the conventional microscope. Participants rated the image quality with the conventional microscope as higher, whereas the field of view and ergonomics were favorable in the digital 3D camera system. Exoscopes are optics suitable for performing simple microvascular procedures and are superior to classical microscopes ergonomically. Thus far, they are inferior to classical microscopes in terms of image quality and 3D imaging.

Assisting in Microsurgery: Operative and Technical Considerations

Microsurgery is technically challenging, typically requiring a primary surgeon and an assistant to complete several key operative steps. These may include manipulation of fine structures, such as nerves or vessels in preparation for anastomosis; stabilization of the structures; and needle driving. Even seemingly mundane tasks of suture cutting and knot tying require fine coordination between the primary surgeon and assistant in the microsurgical environment. Although prior literature discusses the implementation of microsurgical training centers at academic institutions and residency programs, there is a paucity of work describing the role of the assistant surgeon in a microsurgery operation. In this surgical technique article, the authors discuss the role of the assisting surgeon in microsurgery, with recommendations for trainees and attendings alike.

Hurdles of Cataract Surgery: Veterinary Ophthalmology Resident's Perspective (Part B)

The purpose of this study was to describe veterinary ophthalmology residents' perceived preparedness for performing cataract surgery who are currently enrolled in, or recently graduated from, veterinary academic or private practice institutions. A descriptive survey was distributed online to 127 residents at academic and private practice training programs in the United States. The survey included items about educational resources available for residents and techniques commonly taught during cataract surgery. Residents were asked to describe their perceived preparedness in performing various surgical steps or techniques, difficulty of each surgical step, and the available educational resources. Thirty-five (27.5%) residents completed the survey and were included in this study. Residents who had access to wet labs gained surgical competency in creating a clear corneal incision, capsulorhexis, and wound closure. They reported sculpting with the phacoemulsification handpiece, quadrant or cortical removal, and capsulorhexis as most difficult and were not as prepared or a little prepared in performing capsulorhexis and sculpting during active phacoemulsification. When comparing residents' perceived competency before and after their first surgical experience, there was a significant change in their ability to perform all surgical steps except hydrodissection (p < .05). Cataract surgery is one of the more advanced surgical skills obtained during residency training. Supervised wet lab time improves a resident's preparedness for executing certain surgical steps. However, further research is needed to determine whether educational resources such as structured curriculum or virtual simulation may improve residents' preparedness for executing surgical steps not easily replicated in a wet lab.

A randomized study on the value of self-directed versus traditional mentor-led microsurgical training

Objective

Analyze efficacy of self-directed resident microvascular training versus a mentor-led course.

Study Design

Randomized, single-blinded cohort study.

Setting

Academic tertiary care center.

Methods

Sixteen resident and fellow participants were randomized into two groups stratified by training year. Group A completed a self-directed microvascular course with instructional videos and self-directed lab sessions. Group B completed a traditional mentor-led microvascular course. Both groups spent equal time in the lab. Video recorded pre and post-course microsurgical skill assessments were performed to assess the efficacy of the training. Two microsurgeons, blinded to participant identity, evaluated the recordings and inspected each microvascular anastomosis (MVA). Videos were scored using an objective-structured assessment of technical skills (OSATS), a global rating scale (GRS), and quality of anastomosis scoring (QoA).

Results

The pre-course assessment identified that the groups were well matched with only "Economy of Motion" on the GRS favoring the mentor led group (p = .02). This difference remained significant on the post assessment (p = .02) Both groups significantly improved in OSATS and GRS scoring (p < .05). There was no significant difference in OSATS improvement between the two groups (p = .36) or improvement in MVA quality between groups (p > .99). Time to completion of MVA significantly improved overall by a mean of 8 min and 9 s (p = .005) with no significant difference between post training times to complete (p = .63).

Conclusion

Different microsurgical training models have previously been validated as effective methods for improved MVA performance. Our findings indicate that a self-directed microsurgical training model is an effective alternative to a traditional mentor driven models.

Level of Evidence

Level 2.

Relevance of a Simulation Model to Microvascular Surgery for Military Surgical Residents

Introduction

Microsurgical training is an asset for deployed military orthopaedic surgeons who frequently treat hand or nerve injuries in the field. The objective of this study was to evaluate a microvascular surgery simulation model intended to prepare residents prior to their enrolment in conventional microsurgery degree training.

Methods

An experimental study was conducted to evaluate technical progress and satisfaction of military surgical residents using a model based on Japanese noodles with four tests of increasing difficulty. Objective endpoints included instruments handling, distribution, and quality of stitches, as well as anastomoses duration. Responses to the Structured Assessment of Microsurgery Skill self-assessment questionnaire were also analyzed.

Results

Nine residents from different specialties participated in the study. Their anastomoses quality and average satisfaction significantly increased between the first and the last session (p < 0.05). Conversely, the average operating time decreased significantly over the sessions (p < 0.001).

Conclusion

This simulation model seems to constitute a satisfactory initiation to microsurgery and could limit the use of animal models. It could also be included in the continuing education of military surgeons who have an occasional microsurgical practice during deployments.

High-fidelity, simulation-based microsurgical training for neurosurgical residents

OBJECTIVE

Simulation is increasingly recognized as an important supplement to operative training. The live rat femoral artery model is a well-established model for microsurgical skills simulation. In this study, the authors present an 11-year experience incorporating a comprehensive, longitudinal microsurgical training curriculum into a Canadian neurosurgery program. The first goal was to evaluate training effectiveness, using a well-studied rating scale with strong validity. The second goal was to assess the impact of the curriculum on objective measures of subsequent operating room performance during postgraduate year (PGY)–5 and PGY-6 training.

METHODS

PGY-2 neurosurgery residents completed a 1-year curriculum spanning 17 training sessions divided into 5 modules of increasing fidelity. Both perfused duck wing and live rat vessel training models were used. Three modules comprised live microvascular anastomosis. Trainee performance was video recorded and blindly graded using the Objective Structured Assessment of Technical Skills Global Rating Scale. Eleven participants who completed the training curriculum and 3 subjects who had not participated had their subsequent operative performances evaluated when they were at the PGY-5 and PGY-6 levels.

RESULTS

Eighteen participants completed 106 microvascular anastomoses during the study. There was significant improvement in 6 measurable skills during the curriculum. The mean overall score was significantly higher on the fifth attempt compared with the first attempt for all 3 live anastomotic modules (p < 0.001). Each module had a different improvement profile across the skills assessed. Those who completed the microvascular skills curriculum demonstrated a greater number of independent evaluations during superficial surgical exposure, deep exposure, and primary maneuvers at the PGY-5 and PGY-6 levels.

CONCLUSIONS

High-fidelity microsurgical simulation training leads to significant improvement in microneurosurgical skills. Transfer of acquired skills to the operative environment and durability for at least 3 to 4 years show encouraging preliminary results and are subject to ongoing investigation.

Online training module for micro suturing incorporating motor imagery and mental practice: a design and development research study

INTRODUCTION

There have been reduced opportunities for surgical skill acquisition due to the COVID-19 pandemic and the regulated training hours. Despite these challenges, self-regulated learning allows trainees to learn continuously, and one form of this is through mental practice and motor imagery. The study aimed to design and develop an online basic micro suturing training module for skill acquisition for self-regulated learning using a low-fidelity rubber glove model.

METHODS

This study utilized a design and developmental research framework and Mayer's multimedia theory guidelines. The primary author created an online instructional module on micro suturing based on the ADDIE instructional design model. This module was then evaluated in a pilot study comparing the new training model to traditional methods of learning using an experimental design.

RESULTS

This study describes the use of Design and Development Research to create a new model for surgical skill training and a tool for producing instructional materials and learning products for online learning. The product was evaluated using an experimental design and showed a significant effect on the quality of motor skill outcome and the richness of motor imagery using the resource developed in the research.

CONCLUSION

This study describes the methodological approach of a design and developmental framework to create an online training module for micro suturing which has significant utility in hand surgery.

Microsurgical training with chicken wings: Could it be an option to increase experience for vascularized bone flaps?

OBJECTIVE

To our knowledge, a vascularized bone flap training model has not been described in the literature. In this study, we hypothesized that chicken wing radius bone can be used as a cheap, realistic and easily accessible vascularized pedicled bone flap training model.

METHODS

A final total of 10 specimens were included in the study. All procedures were planned and conducted by the same surgeon. In all 10 specimens, the length of the radius bone and the length of the vascularized bone flap were measured with a standard ruler. The external diameters of the ulnar artery and the radial artery forming the flap pedicle were measured.

RESULTS

Flap harvesting time (40.4 ± 7.98') was measured as the time between proper positioning of the chicken wing and the complete separation of the flap from the wing. Mean radius bone length was 6.09 ± 0.72 cm, bone flap length (3.92 ± 0.36 cm) was measured as the distance between two osteotomies in the maximum length of bone (proximal and distal) according to the preparation of the radial artery pedicle. Mean radial artery pedicle external diameter was 0.51 ± 0.05 mm, while mean ulnar artery pedicle external diameter was 0.6 ± 0.04 mm. On average, 4.3 ± 0.82 perforators of the radial artery (to the other regions of the flap) were ligated.

CONCLUSION

We think that this model can be a pioneer in defining the bone flap model in living animals in future studies. Since this inanimate animal model is a cost-effective and easily accessible technique, it offers the opportunity to be applied easily and repeatedly, even in the comfort of surgeons' homes.

A portable, low-cost practice model for microsurgical skills training

PURPOSE

We describe a portable practice model for acquisition of microsurgical skills using widely available inexpensive tools and materials as a model in learning ophthalmic corneal suturing skills.

METHODS

Interested participants without prior microsurgery experience affiliated with the Jacobs School of Medicine and Biomedical Sciences with no prior microsurgical experience qualified to participate. Each participant completed written informed consent. We developed a 3-dimensional micro-stellated icosahedron model using microtubules, monofilament fishing line, jewelers' forceps, and a basic laboratory dissection microscope. We tested this model in improving microsurgical skills in a randomized, controlled intervention trial. Following a pre-assessment task of passing a microsurgical needle and performing a tie, participants were randomized to a control or an intervention (building the micro-stellated icosahedrons) group. The assessment task was repeated after two weeks. Videos of pre- and post-assessments were rated by two masked ophthalmologists. Technique scores and time to complete microsurgical tasks were analyzed to determine improvement in skills.

RESULTS

A total of 27 microsurgically naïve participants were recruited and randomized (14 Intervention / 13 Control). Comparing pre- and post-assessments, the intervention group showed significant decrease in time required to pass the needle (P = 0.018) and significant improvement in technical scores. (P = 0.001). In the control group, there was no significant decrease in time or improvement in technical scores.

CONCLUSIONS

The portable inexpensive micro-stellated icosahedron skills acquisition model is an effective practice model to acquire skills necessary to perform a microsurgical tie. The similarity in dimensions between the model and the eye suggests translatability to ophthalmic surgery.

Simulation in Hand Surgery: A Literature Review

BACKGROUND

Due to duty hour regulations, patient safety and inadequate operative time simulation have become a necessary part of surgical education and training in residency. Currently, there is no formal adoption of simulators for the use of surgical education or assessment in hand surgery. This literature review analyzes that the simulation techniques established thus far in hand surgery.

METHODS

A comprehensive literature search was performed on PubMed. Search results were filtered by title and abstract to isolate articles that were relevant to simulation in hand surgery. Articles that were nonspecific to the hand, non-English and cadaveric were excluded. Additional articles were identified through references from the initial search.

RESULTS

A total of 1192 articles were yielded from the initial query. After the application of the inclusion criteria, this was narrowed down to 28 articles. Another 8 additional articles were excluded as they did not pertain to the hand although the simulators could be adapted for hand surgery. A total of 20 articles were included in this study.

CONCLUSIONS

Surgical simulation is a growing and essential field of surgical education. Simulators in hand surgery are limited and require further research and validation. Like other surgical subspecialties, hand surgery may benefit from the adoption of an official simulation curriculum for the assessment of residents and enhancement of technical skills.

Microsurgical Anastomosis Rating Scale (MARS10): A Final Product Scoring System for Initial Microsurgical Training

Background

High cost and ethical controversy of using living models in microsurgical training made non-living models more popular. However, non-living models don't provide appropriate feedback of microsurgical performance. Currently existing Global Rating Scales used for advanced microsurgical skills validation are difficult to apply on non-living model. This study presents a simple instrument for basic assessment of microsurgical anastomosis on non-living model.

Methods

Seventy medical students were divided into 2 groups depending on their prior microsurgical experience. Each participant performed 3 end-to-end anastomoses on chicken femoral artery model. Anastomoses were reviewed by 3 blinded experts and then photographed. Evaluation included a patency tests, longitudinal cut of anastomosis, and the newly proposed tool 10 Point Microsurgical Anastomosis Rating Scale (MARS10). Presented scale consists of 5 factors important for anastomosis closure (anastomosis closure, suture spacing, bites size, knot tying, and cut ends length), graded on 3 point scale (0-2 points). Results were analyzed with analysis of variance, Spearman correlation, and t Student test.

Results

Anastomoses evaluated by experts as patent significantly correlated with a high summary score in MARS10 scale (r = 0.73 P < .0001). There was a significant difference in MARS10 score between groups (P < .0001). There were no significant inter-rater differences in scoring among all 3 evaluators (p > .05).

Conclusions

10 Point Microsurgical Anastomosis Rating Scale is a quick, valid, and reliable tool to assess microsurgical end-to-end arterial anastomoses on non-living model.

Introducing a Realistic, Low-Cost Simulation Model for Clipping of Brain Aneurysms

BACKGROUND

The current trend toward endovascular treatment of brain aneurysms may have a negative impact on young neurosurgeons who are less exposed to these lesions, thus affecting the acquisition of surgical skills in the field. Different training models have emerged to help cope with this issue, but these have specific pitfalls. Training models based on live animals or cadaveric specimens face increasing restrictions as regulations become a barrier in accessibility for everyday skills development. We introduce a novel, realistic, and inexpensive simulation model using a fresh bovine brain, and we assess its face and content validity as a training tool.

METHODS

A fresh bovine brain is used to simulate microsurgical fissure dissection. Arterial and aneurysmal components are created with arteries and veins harvested from chicken thigh. A 12-item questionnaire using the Likert numeric scale (grades 1 - 5) was used to assess the validity of model in 10 surgeons.

RESULTS

Ten neurosurgeons performed the simulated clipping of the aneurysm and completed a questionnaire. All surgeons surveyed responded "agree" or "strongly agree" that the simulator, and the skills trained with it, are comparable to clipping brain aneurysms. All respondents believed that this simulator could improve patient safety.

CONCLUSIONS

We present a novel, realistic, and inexpensive simulation model for the clipping of brain aneurysms. This model was partially validated by the opinion of field experts. We believe this model has the potential to become a useful training tool for young neurosurgeons who have little exposure to real aneurysm cases.

Evaluation of quality and educational effect of microsurgery videos on YouTube: a randomized controlled trial

Widespread use of smartphones and wireless internet have made YouTube an easily accessible educational modality. Many residents use YouTube to acquire knowledge regarding microsurgical techniques; however, its quality and effect has not been verified. We included 22 residents working in the Department of Plastic and Reconstructive Surgery at our institute. Using block randomization, seven were allocated to a textbook group (TG), eight to a free-searching group (FSG), and seven to a designated-video group (DVG). After reviewing textbooks, YouTube videos, or designated videos, respectively, each group performed microsurgical anastomosis using artificial vessels. The total procedure time, Objective Structured Assessment of Technical Skills (OSATS), operative errors, and degree of leakage were assessed by blinded evaluators. Self-confidence rates were also compared. The YouTube groups (FSG and DVG) performed better than the TG. Although procedure time was significantly longer in the DVG (p = .006), the performance of DVG was better than that of TG in all assessments (OSATS: p = .012; operative errors: p = .002; leakage: p = .010). FSG showed more operative errors (p = .004) and leakage (p = .007) compared to DVG, but had higher OSATS (p = .008) and fewer operative errors (p = .002) than TG. The post-intervention confidence rates were significantly higher in FSG and DVG compared to TG (p = .002 and p = .001, respectively). Although there are concerns regarding the reliability of YouTube videos, microsurgery videos on YouTube had positive effects on microsurgery practice. Therefore, YouTube may help to improve the microsurgical skills of residents. If a quality control system is introduced for YouTube videos, their educational effects may be enhanced.

Mastering microsurgery: A novel benchmarking tool for microsurgical training

INTRODUCTION AND OBJECTIVE

The shift of surgical training from apprenticeship model towards competency-based training requires objective assessments of microsurgical skills to achieve mastery. Our objective was to create a novel platform to provide feedback to surgical trainees relative to competency expected at their level of exposure.

METHODS

A 5-day simulated microsurgery course was run between 2013 and 2016 with 118 participants. Video recordings of end-to-end micro-anastomoses were collected on days 1, 3, and 5, along with analysis of hand motion . Videos were assessed to calculate the QMUL Global Rating Scale (QMUL GRS). Two charts were created to track the acquisition of microsurgical skills. One to plot the number of hand movements and the other for QMUL GRS, against the participants' cumulative number of micro-anastomoses performed. Participant data were used to calculate a skills acquisition line for each quartile, analogous to percentiles on a growth chart.

RESULTS

For a cumulative number of 0 prior micro-anastomoses, the GRS score at the 25th, 50th, and 75th percentile was 45.5, 55, and 62, respectively. As the number of cumulative anastomoses increased, there was a distinct increase in the GRS score to 89.5, 93, and 92 for the group with 55-100 previous micro-anastomoses. This was in keeping with a decreased number of hand movements with increasing experience.

CONCLUSION

In conclusion, our tool allows trainees to track where they lie in the skill spectrum relative to prior experience which permits the provision of focused training to trainees at lower percentiles, which has potential to translate to improved clinical outcomes.

A Comparison of the Use of Two-Dimensional and Three-Dimensional Visualization Systems by Novice and Experienced Microsurgeons in Microsurgical Vessel Anastomosis: An Analysis Using the Chicken Model

BACKGROUND

 Various studies have discussed the benefits of applying three-dimensional (3D) techniques, specifically its advantages with respect to ergonomics, feasibility, and the rate of learning achievable in microsurgery training. However, no study has been conducted that compares the operator experience of using two-dimensional (2D) and 3D systems in microsurgical training. The aim of this study is to compare 2D- and 3D-assisted microsurgical training in novices based on anastomosis of chicken femoral arteries.

METHODS

 The participants were grouped by previous microsurgical experience. Group A includes novice participants. Group B includes 2D-experienced participants. Group C includes both participants in groups A and B. A questionnaire composed of 10 parameters in the field of image quality, dexterity, ergonomic, and feasibility will be filled out after each participant finished their anastomoses by the 2D and 3D systems.

RESULTS

 The results demonstrated 3D system was scored better on "field of view" (p = 0.004), "less tremor" (p = 0.005), "neck/upper back comfort" (p = 0.043), "lower back comfort" (p = 0.015), "technical feasibility" (p = 0.020), and "educational feasibility" (p = 0.004) in group A (N = 12). In group B (N = 9), 3D system was scored better on "field of view" (p = 0.041) but worse on "image resolution" (p = 0.031).

CONCLUSION

 With the 3D visualization system for microsurgical anastomosis of chicken femoral model, there are significant improvements in the field of view, stability, ergonomics, and educational value compared with 2D system among all participants. Accordingly, 3D-assisted microsurgery training can be a novel and potential popular training method.

The "STARS-CASCADE" Study: Virtual Reality Simulation as a New Training Approach in Vascular Neurosurgery

OBJECTIVE

Surgical clipping has become a relatively rare procedure in comparison to endovascular exclusion of cerebral aneurysms. Consequently, there is a declining number of cases where young neurosurgeons can practice clipping. For this reason, we investigated the application of a new 3-dimensional (3D) simulation and rehearsal device, Surgical Theater, in vascular neurosurgery.

METHODS

We analyzed data of 20 patients who underwent surgical aneurysm clipping. In 10 cases, Surgical Theater was used to perform the preoperative 3D planning (CASCADE group), while traditional imaging was used in the other cases (control group). Preoperative 3D simulation was performed by 4 expert and 3 junior neurosurgeons (1 fellow, 2 residents). During postoperative debriefings, expert surgeons explained the different aspects of the operation to their younger colleagues in an interactive way using the simulator. Questionnaires were given to the surgeons to get qualitative feedback about the simulator, and the junior surgeons' performance at simulator was also analyzed.

RESULTS

There were no differences in surgery outcomes, complications, and surgical duration (P > 0.05) between the 2 groups. Senior neurosurgeons performed similarly when operating at the simulator as compared with in the operating room, while junior neurosurgeons improved their performance at the simulator after the debriefing session (P < 0.005).

CONCLUSIONS

Surgical Theater proved to be realistic in replicating vascular neurosurgery scenarios for rehearsal and simulation purposes. Moreover, it was shown to be useful for didactic purposes, allowing young neurosurgeons to take full advantage and learn from senior colleagues to become familiar with this demanding neurosurgical subspecialty.

Validating a Low-Fidelity Model for Microsurgical Anastomosis Training

With cost, size, and availability in mind, we developed a low-fidelity microsurgery anastomosis model for mastery of the tool skills needed to execute microsurgical procedures. The model combined the use of a cannulated Konnyaku Shirataki (KS) noodle with a low-cost, industrial inspection, trinocular stereo (IITS) microscope. The purpose of this study was to establish face and construct validity of this novel "combined" microsurgery training tool.

Methods

Fifteen participants, divided into 3 groups based on microsurgery experience, attempted microsurgical anastomoses of a cannulated KS noodle using the IITS microscope. Participants were asked to (1) manipulate the noodle ends adjacent to each other, (2) place a single 7-0 nylon suture through the opposed ends, and (3) complete the anastomosis. To determine construct validity, the performance of the microsurgical repair (maximum score 53 points) and time-to-anastomosis was assessed. To determine face validity, microsurgeons were given a 25-item, 5-point scale survey rating their experience with the model.

Results

Participants included 5 microsurgeons, 5 experienced trainees, and 5 novices. The microsurgeons judged the IITS microscope to be a close analog to an operating microscope (4.6/5 points), the combined model to have high educational value (4.7/5 points), and somewhat technical similarity with microsurgery in the operating room (OR) (3.7/5 points). The median technical score was 50 among microsurgeons, 40 among experienced trainees, and 27 among novices. Increased training level was associated with greater technical score among all 3 groups (p=0.002). The median time-to-anastomosis was 5.88 minutes for microsurgeons, 8.37 minutes for experienced trainees, and 17.10 minutes for novices. Increased training level was associated with shorter time-to-anastomosis (p=0.003).

Conclusion

The use of the KS noodle with a benchtop stereo microscope is a novel approach to microsurgical training. It is inexpensive, available, conducive to high-repetition training, and suited to many learning environments. Microsurgeons found that this combined model was representative of microsurgery in the OR, and we concluded face validity. Furthermore, an association was demonstrated between training level and performance on the model, suggesting construct validity.

Microsurgical suturing assessment scores: a systematic review

Several scoring scales for the assessment of microsurgical skills have been established and validated with the same basic parameters. The study aims to review the existing scales to highlight those parameters, which can be utilized uniformly across all neurosurgical training centers. An online search was conducted and all the surgical scores pertinent to microsurgical suturing were reviewed. The scales were compared to identify parameters, which were important for skill development and assessment in neurosurgical trainees. Seven assessment scales were identified which assessed the trainee's proficiency in microsurgical suturing. The objective structured assessment of technical skills (OSATS) and Northwestern Objective Microanastomosis Assessment Tool (NOMAT) were identified as the most widely used and validated assessment scales. The newer scales University of Western Ontario microsurgical skills acquisition/assessment (UWOMSA) and structured assessment of microsurgery (SAMS) were notable for the division of the skills. The knot strength, suture separation, and suture intervals were the most important parameters in all scales. Each scale has its strength in the assessment of the microsurgical proficiency of neurosurgical trainees. However, a more uniform scale that can be applied as per the level of the neurosurgical trainee is necessary.

Validation of an in vivo porcine simulation model of pedicled latissimus dorsi myocutaneous flap elevation

Background

In vivo and ex vivo simulation training workshops can contribute to surgical skill acquisition but require validation before becoming incorporated within curricula. Ideally, that validation should include the following: face, content, construct, concurrent, and predictive validity.

Methods

During two in vivo porcine surgical training workshops, 27 participants completed questionnaires relating to face and content validity of porcine in vivo flap elevation. Six participants’ performances raising a pedicled myocutaneous latissimus dorsi (LD) flap in the pig (2 experts and 4 trainees) were sequentially and objectively assessed for construct validity with hand motion analysis (HMA), a performance checklist, a blinded randomized procedure-specific rating scale of standardized video recordings, and flap viability by fluorescence imaging.

Results

Face and content validity were demonstrated straightforwardly. Construct validity was demonstrated for average procedure time by HMA between trainees and experts (p = 0.036). Skill acquisition was demonstrated by trainees’ HMA average number of hand movements (p = 0.046) and fluorescence flap viability (p = 0.034).

Conclusion

Face and content validity for in vivo porcine flap elevation simulation training were established. Construct validity was established for an in vivo porcine latissimus dorsi flap elevation simulation specifically. Predictive validity will prove more challenging to establish.

Level of evidence: Not ratable .

Thiel-embalmed porcine placenta: A valid and reusable microsurgical practice model

BACKGROUND

Simulation models are increasingly important for skill acquisition during microsurgery training. Prosthetics, living and non-living biological models have been proposed in the literature in the optics of recreating real-life scenarios in a controlled environment. This study aims to validate and prove the reusability of a novel non-living biological model: the porcine placenta.

METHODS

A prospective comparative study was carried out to assess face and content validities of the proposed model, as well as the reusability and quality of the Thiel-embalming method. Participants were asked answer a questionnaire for each anastomosis they performed on porcine placental vessels of ≤2mm (small) and 2-4mm (large). Scores were classified according to different subgroups, either small or large vessels and first or second sessions. Reliability analysis of the questionnaire was carried out using Cronbach's α, to ensure an α>0.7. Median scores for each question were analyzed using boxplots and compared amongst each subgroup using a non-parametric independent Mann-Whitney U test.

RESULTS

With nine participants, the Cronbach's α for each category of question was 0.867, 0.778, 0.720 and 0.593. Statistical differences were found between responses of small and large vessels on 5/10 questions, where large vessels reported higher validity. No statistical differences were found between scores of the first and second sessions.

CONCLUSION

By evaluating face and content validity, the Thiel-embalmed porcine placenta has proven its suitability as a microsurgery model, especially for vessels of larger caliber. Qualities that distinguish this model is its reliable reusability, its low cost-effectiveness, and its ethical acceptability.

Ex Vivo Ovine Model for Surgical and Microsurgical Training on Parotidectomy and Facial Nerve Reanimation: Proposal of Structured Training Program

INTRODUCTION

 Facial nerve palsy has a great physical and psychological impact on patients, so the avoidance of facial nerve damage during surgery and its reanimation are important for Otolaryngologists and head and neck surgeons. The acquisition of anatomical knowledge and surgical training regarding the parotid surgery and facial nerve is mandatory, but not easy to achieve. Surgical simulation is a reliable alternative to the on-the-job learning. In the study, we tested an ex vivo animal model to obtain the basic and advanced skills of parotid gland surgery and facial nerve reconstruction/reanimation.

MATERIALS AND METHODS

 A prospective cohort study has been conducted on ovine head and neck specimen. A junior resident, a senior resident, and an expert surgeon were involved in a step-by-step preplanned dissection, divided in macroscopic and microscopic. Each procedure was recorded and evaluated by an expert surgeon following an adapted rating scale.

RESULTS

 A statistically significant improvement in terms of execution times and quality of the work was show in most of the surgical steps and for many quality items by the junior and senior residents, while the expert surgeon, as expected, did not show any improvement.

DISCUSSION

 Our ex vivo ovine model provided the trainee with close-to-real tissues in term of elastic resistance and consistency, to learn the skills requested in a head and neck surgery, on a reproducible environment. It is mandatory to have a feedback, which focuses on the quality of the work through valid and reliable assessment of technical skills. The judgment parameters should be reproducible and focused on the specific surgical procedure. Some limitations to this study are present, such as anatomical differences between ovine and human and the limited number of study participants.

CONCLUSION

 This proposal of training program on the ex vivo ovine model for the acquisition of skills needed in head and neck surgery proved to be feasible, effective, repeatable, and cheap.

The Benefits of Expert Instruction in Microsurgery Courses

BACKGROUND

 Microsurgery requires repeated practice and training to achieve proficiency, and there are a variety of curriculums available. This study aims to determine the importance of an expert instructor to guide students through procedures. We compared student proficiency across two microsurgery courses: one with (Columbia University, United States [CU] cohort) and one without a dedicated microsurgery instructor (University of Thessaloniki, Greece [UT] cohort).

METHODS

 Students were divided into two cohorts of 22 students (UT cohort) and 25 students (CU cohort). Student progress was evaluated by examining patency (lift-up and milking tests), anastomotic timing, and quality (Anastomosis Lapse Index [ALI]) of end-to-end arterial and venous anastomoses on day 1 and again on day 5. Chi-squared tests evaluated patency immediately and 30 minutes postoperation. t-Tests evaluated anastomotic timing and ALI scores. p-Values < 0.05 were considered significant.

RESULTS

 We evaluated progress within and between each cohort. Within the CU cohort, the quality of the arterial and venous anastomosis improved, respectively (by 54%, p = 0.0059 and by 43%, p = 0.0027), the patency of both the arterial and venous anastomosis improved, respectively (by 44%, p = 0.0002 and by 40%, p = 0.0019), and timing of arterial and venous anastomosis reduced respectively (by 36%, p = 0.0002 and by 33%, p = 0.0010). The UT cohort improved the quality of their arterial anastomoses (by 29%, p = 0.0312). The UT cohort did not demonstrate significant improvement in the other above-mentioned parameters. The CU cohort improved materially over the UT cohort across categories of quality, patency, and timing.

CONCLUSION

 There are clear benefits of an expert instructor when examining the rate of progress and proficiency level attained at the conclusion of the course. We suggest students who are seeking to maximize proficiency in microsurgical procedures enroll in courses with an expert instructor.

Microsurgery Training in Plastic Surgery

Advances in surgical instruments, magnification technology, perforator dissection techniques, and vascular imaging over the past decades have facilitated exponential growth in the field of microsurgery. With wide application potential including but not limited to limb salvage, breast reconstruction, lymphedema treatment, and sex affirmation surgery, microsurgery represents a critical skill set that powerfully augments the reconstructive armamentarium of plastic surgeons. Accordingly, microsurgical training is now a critical component of the plastic surgery residency education curriculum. Trainees must meet minimum microsurgery case requirements in addition to the core competencies outlined by the Accreditation Council for Graduate Medical Education. Through the use of simulation models, residency programs increasingly incorporate early skills development and assessment in microsurgery in the laboratory. Beyond residency, microsurgery fellowships offer additional exposure and refinement by offering volume, complexity, autonomy, and possible focused specialization. With continued refinement in technology and advances in knowledge, new types of simulation training models will continue to be developed and incorporated into microsurgery training curricula.

Maintaining Effective Microsurgery Training with Reduced Utilisation of Live Rats

Background: Microvascular surgery is now an integral part of many surgical disciplines, and the success of these procedures relies on the technical skills of the surgeon. Although numerous training models and simulations have been developed, the living rat model is favoured for its high fidelity to clinical microsurgery. However, there are serious ethical concerns over the use of live models for training. The aim of this study was to demonstrate if effective skill acquisition was possible with a reduction in the number of live rats.

Methods: Two course structures were designed, that were implemented. Total training hours remained the same in both the courses, but the number of rats used was reduced from conventional five rats per participant to four in group A and to three in group B while increasing the training time spent on synthetic and ex-vivo models. We assessed the effectiveness of the courses by comparing the patency rates, the time taken per anastomosis and efficiency of the utilisation rate of rats.

Results: There were 30 participants in Group A and 28 participants in group B. We observed that group B was able to perform anastomosis in a significantly shorter time and with patency rates similar to group A in spite of a lesser number of rats used in the training.

Conclusions: we were able to conclusively demonstrate that it was possible to reduce live rat usage in microsurgical training without compromising on the quality of training.

Determining the Effect of External Stressors and Cognitive Distraction on Microsurgical Skills and Performance

Introduction: Microsurgery is an essential element of Plastic Surgery practice. There is a paucity of studies assessing the impact of stress and cognitive distraction on technical microsurgical performance. The ability to complete cognitive and technical skills in parallel has not been assessed in a microsurgical setting.

Aim: To test the hypothesis that cognitive distraction and external stressors negatively affect microsurgical performance in a high fidelity simulation setting.

Materials/Methods: Fourteen surgeons across all levels of training undertook 2 microsurgical skills sessions, 1 month apart. Session one established baseline microsurgical skill. In session two, skills were assessed with the introduction of realistic operative room cognitive distractions (ORDIs). Outcome measures were efficiency and accuracy, measured by Time to Completion (TTC) and Anastomosis Lapse Index (ALI), respectively.

Key Results: Fourteen participants (6 novices, 5 plastic surgery specialist trainees and 3 consultants) completed both microsurgical skills sessions. In total, 28-microvascular anastomosis were analyzed. Mean baseline TTC for the group was 20.36 min. With cognitive distraction and external stress mean TTC decreased to 17.87 min. Mean baseline ALI score for the group was 3.32 errors per anastomosis. The introduction of cognitive distraction and external stress increased the mean to 4.86 errors per anastomosis. Total errors per anastomosis increased from 91 errors at baseline to 137 errors with cognitive distraction and external stress. Under stress, participants were more efficient but had reduced anastomotic accuracy.

Conclusion: Under stress, surgeons were more efficient, this translated into faster completion of a microsurgical anastomosis. Efficiency, however, came at the expense of accuracy.

Vein Graft Interposition: A Training Model Using Gradually Thawed Cryopreserved Vessels

INTRODUCTION

Microsurgical interposition of vein grafts is an extraordinarily filigree surgical technique, which requires both sound theoretical knowledge and solid manual skills. Although there are a large number of training models, the majority of these are either relatively expensive, technically complex, or employ synthetic materials with poor resemblance to human tissue. The authors' model allows training of ex vivo vein graft interposition on gradually thawed cryopreserved vessels and it, therefore, is cost-efficient and readily available when needed. Furthermore, it respects the 3R-principle (Reduce-Refine-Replace), as it is based on rat cadaveric vessels.

METHODS

Three trainees with basic microsurgical experience, but without prior performance of vein graft interpositioning, were chosen to perform 20 femoral vein graft (5 mm) interpositions into femoral artery defects. The patency and leakage rate served as qualitative variable and operation time as a quantitative variable for efficiency control.

RESULTS

For the first half of trials, the trainees had a patency failure rate of 50% and for the second half a rate of 13.3%. The leakage rate noticeably decreased from 44.4% in the first half of trials to 10% in the second half. Although the trainees needed 60 minutes on average for their first 10 trials, they improved to 51 minutes for their last 10 anastomoses.

CONCLUSION

The authors' microsurgical model offers a simple, low-cost simulation training, specifically designed for learning of vein graft interposition into arterial defects. The model is associated with a high learning curve, based on an objective control of the anastomoses by assessment of the patency, leakage, and operation time.

The Role of Low-Cost Microsurgical Training Models and Experience with Exercises Based on a Bovine Heart

BACKGROUND

Microscopic training is essential for development of neurosurgical skills. A range of models is reported in the literature for this purpose, including live animals, exvivo, and synthetic material. Among the factors involved in selection and development of a training station, cost is a decisive one.

METHODS

We present a low-cost model to practice microvascular anastomoses using a bovine heart and an artificial perfusion system. We also present a brief review of laboratory models for microsurgical training, focusing on the costs and reproducibility of the different options.

RESULTS

Exvivo models are a great bridging point between nonbiologic and living animal training models. These models have major similarities to human vessels, such as lumen size and malleability of the arteries. The bovine heart model allowed the residents to gain confidence in handling vascular tissue in a microscopic environment.

CONCLUSIONS

Although these models do not resemble anatomic landmarks in the human brain, the bovine heart model allowed the residents to gain confidence in handling vascular tissue in a microscopic environment.

Achieving Microsurgical Competency in Orthopaedic Residents Utilizing a Self-Directed Microvascular Training Curriculum

BACKGROUND

Education in microvascular surgery is limited by variable experience, a difficult learning curve, and potentially catastrophic complications caused by failed anastomoses. Furthermore, utilization of live-animal training models can be difficult because of lack of access and high maintenance costs. The purpose of this study was to determine the effectiveness and cost of a self-directed microvascular training curriculum utilizing synthetic microvessels and nonliving models in an orthopaedic residency program.

METHODS

Twenty-five orthopaedic residents ranging from postgraduate year (PGY)-1 to PGY-4 were prospectively enrolled. The curriculum consisted of learning the basics of microsurgery on nonliving models and progressed to anastomoses on a 1-mm synthetic microvessel. Outcomes included Global Rating Scale (GRS) scores (5 to 25 points), patency, anastomosis time, comfort level (1 to 10 points), time to complete the curriculum, and curriculum utility (1 to 10 points). Blinded qualitative assessments (from 1 to 10 points) of pre-curriculum and post-curriculum anastomoses were made by 4 hand surgery faculty members. Outcome measures were obtained at baseline and post-curriculum. The curriculum cost was calculated as the setup cost and the maintenance cost per resident. Student t tests and Fisher exact tests were utilized for significance.

RESULTS

All residents successfully completed the curriculum. The mean anastomosis time (and standard deviation) decreased from 40 ± 3 minutes to 22 ± 4 minutes (p < 0.001). The mean GRS score improved from 12 ± 2 points to 18 ± 2 points (p < 0.01). Patency was achieved by 44% at baseline evaluation and by 96% at post-curriculum evaluation (p < 0.0001). The mean comfort level improved from 3 ± 1.2 points to 6 ± 1.7 points (p < 0.0001) on a scale of 1 to 10 points. Also on a scale of 1 to 10, the blinded mean qualitative anastomoses score improved from 4.8 ± 2.2 points (poor) to 8.0 ± 1.1 points (good) (p < 0.0001). The mean time to complete the curriculum was 5.5 ± 1.4 hours, and, on a scale of 1 to 10, curriculum utility was rated by the residents to be 8 ± 1.8 points. The cost of the initial setup was $1,795 with a yearly utilization cost per resident of $42.

CONCLUSIONS

The implementation of a self-directed curriculum utilizing synthetic microvessels and nonliving models demonstrated significant improvements in resident microvascular skill. This curriculum represents a modest startup cost and low yearly cost per resident.

Silicone-based simulation models for peripheral nerve microsurgery

BACKGROUND

There is a need for a peripheral nerve model on which surgeons-in-training can simulate the repair of nerve injuries at their own pace. Although practicing on animal models/cadavers is considered the "gold standard" of microsurgical training, the proposed model aims to provide a platform for improving the technical skills of surgical trainees prior to their practice on cadaver/animal models. In addition, this model has the potential to serve as a standardized test medium for assessing the skill sets of surgeons.

METHODS

Several formulations of silicone were utilized for the design and fabrication of a model which realizes the hierarchical structure of peripheral nerves. The mechanical properties were characterized via the Universal Testing Machine; the damage caused by the needle on the entry sites was assessed through scanning electron microscopy (SEM).

RESULTS

Mechanical properties of the formulations of silicone were tested to mimic human peripheral nerves. A formulation with 83.3 wt% silicone oil and 0.1 wt% cotton fiber was chosen to be used as nerve fascicles. Both 83.3 wt% silicone oil with cotton fiber and 66.6 wt% silicone oil without fiber provided a microsuturing response similar to that of epineurium at a wall thickness of 1 mm. SEM also confirmed that the entry of the needle did not introduce significant holes at the microsuturing sites.

CONCLUSIONS

The proposed peripheral nerve model mimicked human tissues mechanically and cosmetically, and a simulation of the repair of a fifth-degree nerve injury was achieved.

Experiences with basic microsurgical training programs and skill assessment methods at the University of Debrecen, Hungary

During the past decades microsurgical training programs together with skill assessment methods had been developing intensively worldwide. Concerning the teaching of basic techniques at various levels, we aimed to summarize the education program types and experiences at our department, in order to define the way of continuity. All in the hope that this summary might contain useful information for other educators as well. About 50 years ago, in the late 1960s, microsurgical basic education had been established in Debrecen. Since the 1990s multilevel education programs have been developed, starting in undergraduate years up to the postgraduate training, residency and continuous medical education programs. In the last three decades about 2,300 participants completed courses, including over 470 residents. The ones who already succeeded microsurgical course as medical students, during residency program could reach better results and skill development. Concluding thoughts, the traditional methods and special experiences are highly important in microsurgical education. The necessary duration and individual training approach are emphasized. Standardization (self and international), comparability, accessibility, providing milestones of microsurgical skills are key factors. Proper feedback and skill assessment (experiences, internationally recognized scores, or combinations) are indispensable, but have to be fitted to the characteristic elements of the course.