Current status of simulation and training models in microsurgery: A systematic review

A simple, novel technique to create silicone vessels for microsurgical training

Background and objectives

Effective microsurgical training necessitates dedicated practice, prompting the development of simulation models that mitigate the hygiene risks, regulatory challenges, and storage difficulties associated with conventional biological models. This study aims to evaluate the preferences of microsurgeons and medical students regarding self-made silicone simulation vessels, comparing them to standard biological models.

Methods

A three-part jig, comprising of a two-part metal clamp component and a transparent acrylic block with 4x4 channels, was designed. This assembly produced 16 vessels with a 1 ​mm inner diameter. Liquid silicone (Ecoflex 00-30), readily accessible from online distributors, was injected into the channels using a syringe. After tightening the clamp component and inserting 16 1 ​mm k-wires, the vessels were left to set for approximately 24 ​h 20 medical students with no prior microsurgical experience and 10 microsurgery-trained surgeons then evaluated these silicone vessels against a commonly used biological model (chicken brachial artery for surgeons or chicken aorta for students). Participants were then surveyed about their preference for a specific model for frequent practice using a 10-point Likert scale.

Results and conclusion

In assessing ideal microsurgical training models, all participants highlighted the importance of realism. Surgeons' main practical considerations were hygiene, availability, and setup and storage ease, while medical students were primarily concerned with cost-effectiveness. Both surgeons and medical students perceived the biological model as more realistic, yet less hygienic and harder to set up and store. Conversely, the silicone model, though deemed less realistic, offered advantages in hygiene, availability, cost-effectiveness, and setup and storage simplicity. The silicone model emerged as the overall favorite amongst all participants for frequent practice. Silicone vessels may serve as a complementary adjunct to biological models, allowing surgeons-in-training to practice their skills outside of the operating room and lab settings.

Impact of Resident and Attending Surgeon Training Level on Free Tissue Transfer Ischemia Time and Complications

BACKGROUND

 Microsurgical free tissue transfer has become an essential method for reconstruction of complex surgical defects, making the level of training an important factor to consider. There is little published regarding the impact of training level on microsurgical outcomes. This study investigates microsurgical free tissue transfer ischemia time and postoperative complications based on resident and attending surgeon experience level.

METHODS

 A retrospective review of all free flaps at a single institution from January 1, 2013, to December 31, 2021 was performed. Linear regression was performed analyzing ischemia time of 497 free flaps and attending surgeon experience defined by years in practice and resident level defined as postgraduate year (PGY). Logistic regression model was used to analyze complications based on attending experience and resident level.

RESULTS

 The average resident PGY was 3.5 ± 0.8; the average attending has been practicing for 6.4 ± 5.1 years. There was no statistically significant difference in ischemia time or complication rates based on resident PGY or attending surgeon experience level.

CONCLUSION

 Lower PGY residents were not found to increase ischemia time or increase complication rates. Lower attending surgeon year was not found to increase ischemia time or increase complication rates compared with surgeons who had been practicing for longer. Microsurgical free tissue transfer is considered a safe procedure in residency training and trainee involvement should be encouraged to improve resident education and enhance technical skills.

Three-dimensional microscope skill acquisition: A randomised controlled study comparing two-dimensional laboratory microscope training, video gaming and virtual reality gaming

INTRODUCTION

Fine microsurgical motor skill acquisition can be challenging. With increasing technological innovation, the methods of microsurgical skills acquisition may change. Studies show that laboratory-based microsurgical training programmes on a 2D microscope significantly improves the microsurgical skill acquisition of novices. However, it remains to be seen if these skills are transferable to a 3D microscope or if gaming agility is more important? We present a randomised control trial of three interventions, namely laboratory tabletop microscope training (LM), high-fidelity video gaming (Sony PlayStation 4 console; VG) and high-fidelity virtual reality gaming (Sony PlayStation VR console; VR) versus a control group.

METHODS

Forty novice medical students were block randomised to four groups: control (no intervention) n = 10, LM n = 10, VG n = 10 and VR n = 10. Participants performed chicken femoral artery anastomosis using the Aesculap Aeos® 3D microscope platform at the baseline and again after the intervention. Performance was evaluated using a modified structured assessment of microsurgery skills (mSAMS) score, time taken to complete anastomosis and time taken for suture placement by two blinded independent assessors.

RESULT

No statistically significant difference was noted between the groups at the baseline. There was a statistically significant improvement in the LM arm between the baseline and post-training for mSAMS score and time for suture placement. In the VG, VR and control groups no statistically significant difference was observed.

CONCLUSION

Our study demonstrates that during early microsurgical training, an intense laboratory-based microsurgical training programme significantly improves a novice's anastomotic performance on a 2D microscope, and these skills are transferable when a 3D anastomosis is carried out. However, focused gaming had no significant effect, and the results were akin to that of the non-intervention group.

Assessment of Microsurgery Simulation Course Access in Plastic Surgery Training Programs

BACKGROUND

 Microsurgery requires complex skill development with a steep learning curve for plastic surgery trainees. Flap dissection courses and simulation exercises are useful to acquire these skills. This study aims to assess plastic surgery training programs' access to and interest in microsurgical courses.

METHODS

 A survey was distributed to plastic surgery residency and microsurgery fellowship program directors (PDs). The survey collected program demographics and attendance of trainees at structured microsurgical skills or flap dissection courses. We assessed if PDs thought trainees would benefit from instructional courses.

RESULTS

 There were 44 residency PD responses (44/105, 41.9%, 36 integrated, 8 independent), and 16 fellowship PD responses (16/42, 38.1%). For residency PDs, 54.5% (24/44) sent residents to flap courses, and 95% (19/20) of remaining PDs felt residents would benefit from attending. In addition, 59.1% of programs (26/44) sent residents to microsurgical skills courses, and 83.3% (15/18) of remaining PDs felt residents would benefit from attending. When examining fellowship PDs, 31.2% of programs (5/16) sent fellows to flap dissection courses and 10/11 of remaining PDs felt fellows would benefit from attending a course (90.1%). Half of programs (8/16) sent fellows to microsurgical skills courses, and 7/8 remaining PDs felt fellows would benefit from attending (87.5%).

CONCLUSION

 Only half of the plastic surgery trainees have access to microsurgical skills and flap dissection courses. The majority of residency and fellowship PDs feel that training courses are valuable. Expanding access to these courses could provide a significant benefit to microsurgical education in plastic surgery training.

Synthetic Simulators for Microsurgery Training: A Systematic Review

Background

Microsurgery has a steep learning curve. Synthetic simulators have proven to be useful training tools for the initial learning stages, as well as being ethically sound, viable, safe, and cost-effective. The objective of this review was to determine the quality, effectiveness, and validity of these simulators as well as to assess their ability to evaluate microsurgical skills.

Methods

A systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was performed. We searched databases (Web of Science, Scopus, and PubMed) to identify original articles describing synthetic training models for microsurgery. Three reviewers evaluated articles for inclusion following predefined selection criteria. Data were extracted from full-texts of included articles.

Results

Thirty-nine studies met the inclusion criteria. A total of 38 different devices have been recorded. Microsurgical training devices offer a low-cost, fast, and consistent method to concretely quantify and assess the initial microsurgical skills of trainees using standardized exercises that can be scored by the examiner. According to the authors, the outcomes were satisfactory, with a tangible improvement in microsurgical abilities, despite the lack of a common comparison scale.

Conclusions

Thanks to their availability, cost, and effectiveness, synthetic models are the recommended option to train basic, intermediate and advanced procedures before executing them on in vivo models.

Augmented and Virtual Reality Applications in Facial Plastic Surgery: A Scoping Review

OBJECTIVES

Augmented reality (AR) and virtual reality (VR) are emerging technologies with wide potential applications in health care. We performed a scoping review of the current literature on the application of augmented and VR in the field of facial plastic and reconstructive surgery (FPRS).

DATA SOURCES

PubMed and Web of Science.

REVIEW METHODS

According to PRISMA guidelines, PubMed and Web of Science were used to perform a scoping review of literature regarding the utilization of AR and/or VR relevant to FPRS.

RESULTS

Fifty-eight articles spanning 1997-2023 met the criteria for review. Five overarching categories of AR and/or VR applications were identified across the articles: preoperative, intraoperative, training/education, feasibility, and technical. The following clinical areas were identified: burn, craniomaxillofacial surgery (CMF), face transplant, face lift, facial analysis, facial palsy, free flaps, head and neck surgery, injectables, locoregional flaps, mandible reconstruction, mandibuloplasty, microtia, skin cancer, oculoplastic surgery, rhinology, rhinoplasty, and trauma.

CONCLUSION

AR and VR have broad applications in FPRS. AR for surgical navigation may have the most emerging potential in CMF surgery and free flap harvest. VR is useful as distraction analgesia for patients and as an immersive training tool for surgeons. More data on these technologies' direct impact on objective clinical outcomes are still needed.

LEVEL OF EVIDENCE

N/A Laryngoscope, 134:2568-2577, 2024.

A microscope in your pocket: can smartphones be used to perform microsurgery?

PURPOSE

To evaluate the use of the latest generation smartphone camera in performing arterial microanastomosis in rats.

METHODS

Ten Wistar rats were divided into 2 groups and underwent anastomosis of the right carotid artery with the aid of magnification from a microscope (group M) and a smartphone camera (group S), to compare patency in 72 hours, as well as to measure the weight of the animals, diameter of the carotid arteries and anastomosis time.

RESULTS

There was no statistical difference between the weight of the animals or the diameter of the carotid arteries. There was a statistical difference for the time spent on anastomoses, which was greater in group S, with higher rates of thrombosis (p < 0.05).

CONCLUSIONS

Although our patency and anastomosis time results were statistically lower in the smartphone group, there was success in some cases. As the segment continues to progress, it is likely that the results will improve in line with the evolution of camera technology.

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.

Educating Future Generations of Surgeons across Borders: Novel Global Linked Hybrid Live Cadaveric Peripheral Nerve Surgical Training Course

Background

This study aimed to evaluate a novel, multi-site, technology-facilitated education and training course in peripheral nerve surgery. The program was developed to address the training gaps in this specialized field by integrating a structured curriculum, high-fidelity cadaveric dissection, and surgical simulation with real-time expert guidance.

Methods

A collaboration between the Global Nerve Foundation and Esser Masterclass facilitated the program, which was conducted across three international sites. The curriculum was developed by a panel of experienced peripheral nerve surgeons and included both text-based and multimedia resources. Participants' knowledge and skills were assessed using pre- and postcourse questionnaires.

Results

A total of 73 participants from 26 countries enrolled and consented for data usage for research purposes. The professional background was diverse, including hand surgeons, plastic surgeons, orthopedic surgeons, and neurosurgeons. Participants reported significant improvements in knowledge and skills across all covered topics (p < 0.001). The course received a 100% recommendation rate, and 88% confirmed that it met their educational objectives.

Conclusions

This study underscores the potential of technology-enabled, collaborative expert-led training programs in overcoming geographical and logistical barriers, setting a new standard for globally accessible, high-quality surgical training. It highlights the practical and logistical challenges of multi-site training, such as time zone differences and participant fatigue. It also provides practical insights for future medical educational endeavors, particularly those that aim to be comprehensive, international, and technologically facilitated.

Enhancing microsurgical skills in neurosurgery residents of low-income countries: A comprehensive guide

Background

The main objectives of this paper are to outline the essential tools, instruments, and equipment needed to set up a functional microsurgery laboratory that is affordable for low-income hospitals and to identify cost-effective alternatives for acquiring microsurgical equipment, such as refurbished or donated instruments, collaborating with medical device manufacturers for discounted rates, or exploring local suppliers.

Methods

Step-by-step instructions were provided on setting up the microsurgery laboratory, including recommendations for the layout, ergonomic considerations, lighting, and sterilization processes while ensuring cost-effectiveness, as well as comprehensive training protocols and a curriculum specifically tailored to enhance microsurgical skills in neurosurgery residents.

Results

We explored cost-effective options for obtaining microsurgery simulators and utilizing open-source or low-cost virtual training platforms. We also included guidelines for regular equipment maintenance, instrument sterilization, and establishing protocols for infection control to ensure a safe and hygienic learning environment. To foster collaboration between low-income hospitals and external organizations or institutions that can provide support, resources, or mentorship, this paper shows strategies for networking, knowledge exchange, and establishing partnerships to enhance microsurgical training opportunities further. We evaluated the impact and effectiveness of the low-cost microsurgery laboratory by assessing the impact and effectiveness of the established microsurgery laboratory in improving the microsurgical skills of neurosurgery residents. About microsutures and microanastomosis, after three weeks of training, residents showed improvement in "surgical time" for ten separate simple stitches (30.06 vs. 8.65 min) and ten continuous single stitches (19.84 vs. 6.51 min). Similarly, there was an increase in the "good quality" of the stitches and the suture pattern from 36.36% to 63.63%.

Conclusion

By achieving these objectives, this guide aims to empower low-income hospitals and neurosurgery residents with the necessary resources and knowledge to establish and operate an affordable microsurgery laboratory, ultimately enhancing the quality of microsurgical training and patient care in low-income countries.

Surgical Anatomy and Exercises Using the Chicken Thigh Sciatic Nerve for Microsurgery Training

Introduction  Vessel repair in a chicken thigh is commonly used in microsurgery training model. The sciatic nerve is closely associated with the vessels and has been used for training nerve coaptation, which has different technical considerations from vessel anastomosis. We describe in detail the relevant surgical anatomy and training exercises that can be used with this model. Methods  With 32 fresh store-bought chicken thighs, 16 were used to analyze the gross and histological features of the sciatic nerve, and 16 were intended to create and perform training models. Results  The average visible length of the nerve in the thigh was 51 mm (standard deviation [SD] 2.57 mm). The average diameter of the nerve was 2 mm (SD 0.33 mm) and was largest at its proximal end (3.21 mm, SD 0.27 mm). The nerve consistently branched into two along the chicken thigh, with more branching subsequently. This simulation model is appropriate not only for the classical end-to-end epineural suture, but also for advanced exercises, in terms of longitudinal fasciculus dissection, mismatched size nerve transfer, injured nerve preparation, and vein conduit technique. Dyeing of nerve fascicles enhanced the visibility of nerve surface quality. Conclusion  The sciatic nerve in the chicken thigh is a suitable and accessible model for microsurgery training. The branching and fascicular patterns of the nerve lends itself well to both novice training and advanced simulation. We have incorporated this model into our training curricula.

Low-fidelity simulation models in urology resident's microsurgery training

PURPOSE

To evaluate the gain of microsurgical skills and competencies by urology residents, using low-fidelity experimental models.

METHODS

The study involved the use of training boards, together with a low-fidelity microsurgery simulator, developed using a 3D printer. The model consists in two silicone tubes, coated with a resin, measuring 10 cm in length and with internal and external diameters of 0.5 and 1.5 mm. The support for the ducts is composed by a small box, developed with polylactic acid. The evaluation of the gain of skills and competencies in microsurgery occurred throughout a training course consisting of five training sessions. The first sessions (S1-S4) took place at weekly intervals and the last session (S5) was performed three months after S4. During sessions, were analyzed: the speed of performing microsurgical sutures in the pre and post-training and the performance of each resident through the Objective Structure Assessment of Technical Skill (OSATS) and Student Satisfaction Self-Confidence tools in Learning (SSSCL).

RESULTS

There was a decrease in the time needed to perform the anastomosis (p=0.0019), as well as a progressive increase in the score in the OSATS over during sessions S1 to S4. At S5, there was a slightly decrease in performance (p<0.0001), however, remaining within the expected plateau for the gain of skills and competences. The SSSCL satisfaction scale showed an overall approval rating of 96.9%, with a Cronback alpha coefficient of 83%.

CONCLUSIONS

The low-fidelity simulation was able to guarantee urology residents a solid gain in skills and competencies in microsurgery.

State of the Art in Immersive Interactive Technologies for Surgery Simulation: A Review and Prospective

Immersive technologies have thrived on a strong foundation of software and hardware, injecting vitality into medical training. This surge has witnessed numerous endeavors incorporating immersive technologies into surgery simulation for surgical skills training, with a growing number of researchers delving into this domain. Relevant experiences and patterns need to be summarized urgently to enable researchers to establish a comprehensive understanding of this field, thus promoting its continuous growth. This study provides a forward-looking perspective by reviewing the latest development of immersive interactive technologies for surgery simulation. The investigation commences from a technological standpoint, delving into the core aspects of virtual reality (VR), augmented reality (AR) and mixed reality (MR) technologies, namely, haptic rendering and tracking. Subsequently, we summarize recent work based on the categorization of minimally invasive surgery (MIS) and open surgery simulations. Finally, the study showcases the impressive performance and expansive potential of immersive technologies in surgical simulation while also discussing the current limitations. We find that the design of interaction and the choice of immersive technology in virtual surgery development should be closely related to the corresponding interactive operations in the real surgical speciality. This alignment facilitates targeted technological adaptations in the direction of greater applicability and fidelity of simulation.

A novel approach to microsurgical teaching in head and neck surgery leveraging modern 3D technologies

The anatomically complex and often spatially restricted conditions of anastomosis in the head and neck region cannot be adequately reproduced by training exercises on current ex vivo or small animal models. With the development of a Realistic Anatomical Condition Experience (RACE) model, complex spatial-anatomical surgical areas and the associated intraoperative complexities could be transferred into a realistic training situation in head and neck surgery. The RACE model is based on a stereolithography file generated by intraoperative use of a three-dimensional surface scanner after neck dissection and before microvascular anastomosis. Modelling of the acquired STL file using three-dimensional processing software led to the model's final design. As a result, we have successfully created an economical, sustainable and realistic model for microsurgical education and provide a step-by-step workflow that can be used in surgical and general medical education to replicate and establish comparable models. We provide an open source stereolithography file of the head-and-neck RACE model for printing for educational purposes. Once implemented in other fields of surgery and general medicine, RACE models could mark a shift in medical education as a whole, away from traditional teaching principles and towards the use of realistic and individualised simulators.

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.

Development and Validation of a Laryngeal Microsurgery Simulation Training System for Otolaryngology Residents

OBJECTIVE

This study aims to create a synthetic laryngeal microsurgery simulation model and training program; to assess its face, content, and construct validity; and to review the available phonomicrosurgery simulation models in the literature.

STUDY DESIGN

Nonrandomly assigned control study.

SETTING

Simulation training course for the otolaryngology residency program at Pontificia Universidad Católica de Chile.

METHODS

Resident (postgraduate year 1 [PGY1]/PGY2) and expert groups were recruited. A laryngeal microsurgery synthetic model was developed. Nine tasks were designed and assessed through a set of programmed exercises with increasing difficulty, to fulfill 5 surgical competencies. Imperial College Surgical Assessment Device sensors applied to the participants' hands measured time and movements. The activities were video-recorded and blindly assessed by 2 laryngologists using a specific and global rating scale (SRS and GRS). A 5-point Likert survey assessing validity was completed by experts.

RESULTS

Eighteen participants were recruited (14 residents and 4 experts). Experts performed significantly better than residents in the SRS (p = .003), and GRS (p = .004). Internal consistency was demonstrated for the SRS (α = .972, p < .001). Experts had a shorter execution time (p = .007), and path length with the right hand (p = .04). The left hand did not show significant differences. The survey assessing validity resulted in a median 36 out of 40 points score for face validity; and 43 out of 45 points score, for global content validity. The literature review revealed 20 available phonomicrosurgery simulation models, only 6 with construct validity.

CONCLUSION

The face, content, and construct validity of the laryngeal microsurgery simulation training program were established. It could be replicated and incorporated into residents' curricula.

Evaluation of a Microsurgery Training Curriculum

BACKGROUND

 Microsurgery is one of the most challenging areas of surgery with a steep learning curve. To address this educational need, microsurgery curricula have been developed and validated, with the majority focus on technical skills only. The aim of this study was to report on the evaluation of a well-established curriculum using the Kirkpatrick model.

METHODS

 A training curriculum was delivered over 5 days between 2017 and 2020 focusing on (1) microscopic field manipulation, (2) knot tying, nondominant hand usage, (3) 3-D models/anastomosis, and (4) tissue experience. The Kirkpatrick model was applied to evaluate the curriculum at four levels: (1) participants' feedback (2) skills development using a validated, objective assessment tool (Global Assessment Score form) and CUSUM charts were constructed to model proficiency gain (3) and (4) assessing skill retention/long-term impact.

RESULTS

 In total, 155 participants undertook the curriculum, totaling 5,425 hours of training. More than 75% of students reported the course as excellent, with the remaining voting for "good." All participants agreed that the curriculum met expectations and would recommend it. Significant improvement in anastomosis attainment scores between days 1 and 3 (median score 4) and days 4 and 5 (median score 5) (W = 494.5, p = 0.00170). The frequency of errors reduced with successive attempts (chi square = 9.81, p = 0.00174). The steepest learning curve was in anastomosis and patency domains, requiring 11 attempts on average to reach proficiency. In total, 88.5% survey respondents could apply the skills learnt and 76.9% applied the skills learnt within 6 months. Key areas of improvement were identified from this evaluation, and actions to address them were implemented in the following programs.

CONCLUSION

 Robust evaluation of curriculum can be applied to microsurgery training demonstrating its efficacy in reducing surgical errors with an improvement in overall technical skills that can extend to impact clinical practice. It allows the identification of areas of improvement, driving the refinement of training programs.

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.

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.

A realistic model for vasectomy reversal training using swine testicles

PURPOSE

To evaluate the viability of the porcine vas deferens as a realistic microsurgical training model for vasectomy reversal.

METHODS

The model uses swine testicles (vas deferent), which are usually discarded in large street markets since they are not part of Brazilian cuisine. The spermatic cord was carefully dissected, and the vas deferens were isolated, measuring 10 cm in length. A paper quadrilateral with 5 cm2 was built to delimit the surgical training field. The objective of the model is to simulate only the microsurgical step when the vas deferens are already isolated. The parameters analyzed were: feasibility for reproducing the technique, patency before and after performing the vasovasostomy, cost of the model, ease of acquisition, ease of handling, execution time, and model reproducibility.

RESULTS

The simulator presented low cost. All models made were viable with a texture similar to human, with positive patency obtained in 100% of the procedures. The internal and external diameters of the vas deferens varied between 0.2-0.4 mm and 2-3 mm, respectively, with a mean length of 9 ± 1.2 cm. The total procedure time was 43.28 ± 3.22 minutes.

CONCLUSIONS

The realistic model presented proved to be viable for carrying out vasectomy reversal training, due to its low cost, easy acquisition, and easy handling, and providing similar tissue characteristics to humans.

Utilization of a 3D Printed Simulation Training Model to Improve Microsurgical Training

Simulation is integral to the development and maintenance of micro- surgical skills. Several simulation models have been described ranging from bench- top to live animal models. High fidelity models are often burdened by cost and ethical issues limiting widespread implementation. This study aims to determine the feasibility of a microsurgical training platform using the Konjac noodle model.

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.

Low cost and easy acquisition: corn grain in microsurgery training

OBJECTIVES

develop an easily accessible model for training the initial motor practice in microsurgery using corn kernels.

METHODS

ten corn kernels (Zea mays) were used. A 7mm longitudinal cut was made on one side of the corn grain. The training consisted of performing 4 simple knots between the edges of the incision, using 10-0 mononylon thread. The parameters analyzed were 1) cost of the model; 2) assembly time of the model test system; 3) time for performing the knots; 4) distance between the knots.

RESULTS

in all corn kernels tested, it was possible to perform the proposed microsurgical suture training, without any difficulty in the procedure. The average time to perform the 4 knots was 6.51±1.18 minutes. The total cost of the simulator model was R$3.59. The average distance between the knots was 1.7±0.3mm. The model developed from corn grains has an extremely low cost when compared to the use of animals or high-tech simulators. Other advantages are the easy availability of canned corn kernels and the possibility of making more than four knots along the 7mm incision.

CONCLUSION

the training model developed has low cost, is easy to acquire and viable for training basic manual skills in microsurgery.

Quantifying Complications: An Analysis of Operative Time and Intraoperative Factors in Microsurgical Breast Reconstruction

BACKGROUND

 Analysis of operative flow has been shown to improve efficiency in breast microsurgery. Both complex decision-making skills and technical mastery are required to overcome intraoperative challenges encountered during microsurgical reconstruction. Effects of intraoperative complications on operative time have not yet been reported.

METHODS

 A retrospective chart review of microsurgical breast reconstructions by three surgeons between 2013-2020 analyzed operative variables and duration. Intraoperative complications were determined from the operative report. Correlations between continuous variables were determined using Spearman correlation coefficients. Nonparametric testing was used when comparing operative duration between groups.

RESULTS

 Operative duration was analyzed for 547 autologous breast reconstruction cases; 210 reconstructions were unilateral and 337 were bilateral. Average operative duration was 471.2 SD 132.2 minutes overall (360.1 SD 100.5 minutes for unilateral cases and 530.5 SD 110.5 minutes for bilateral cases). Operative duration decreased with surgeon experience (r = -0.17, p< .001).Regarding intraoperative complications, difficult donor dissection was correlated with an average operative duration increase of 91.7 minutes (n = 43, 7.9%, p< .001), pedicle injury with an additional 67.7 minutes (n = 19, 3.5%, p = .02) and difficult recipient vessel dissection with an increase of 63.0 minutes (n = 35, 6.4%, p = .003). Complications with anastomosis also showed a statistically significant increase in operative duration, with arterial complications resulting in an increase of 104.3 minutes (n = 41, 7.5%, p< .001) and venous complications resulting in an increase in 78.8 minutes (n = 32, 5.8%, p< .001). Intraoperative thrombus resulted in an increase of 125.5 minutes (n = 20, 3.7%, p< .001), and requiring alternative venous outflow added an average of 193.7 minutes (n = 8, 1.5%, p< .001).

CONCLUSION

 Intraoperative complications in autologous breast reconstruction significantly increase operative time. The greatest increase in operative time is seen with intraoperative thrombosis or requiring alternative venous outflow. As these complications are rarely encountered in breast microsurgery, opportunities for simulation and case-based practice exist to improve efficiency.

Overcoming Barriers in Neurosurgical Education: A Novel Approach to Practical Ventriculostomy Simulation

BACKGROUND

In the high-risk, high-stakes specialty of neurosurgery, traditional teaching methods often fail to provide young residents with the proficiency needed to perform complex procedures in stressful situations, with direct effects on patient outcomes. Physical simulators provide the freedom of focused, hands-on training in a more controlled environment. However, the adoption of simulators in neurosurgical training remains a challenge because of high acquisition costs, complex production processes, and lack of realism.

OBJECTIVE

To introduce an easily reproducible, cost-effective simulator for external ventricular drain placements through various ventriculostomy approaches with life-like tactile brain characteristics based on real patients' data.

METHODS

Whole brain and skull reconstruction from patient's computed tomography and MRI data were achieved using freeware and a desktop 3-dimensional printer. Subsequently, a negative brain silicone mold was created. Based on neurosurgical expertise and rheological measurements of brain tissue, gelatin in various concentrations was tested to cast tactilely realistic brain simulants. A sample group of 16 neurosurgeons and medical students tested and evaluated the simulator in respect to realism, haptics, and general usage, scored on a 5-point Likert scale.

RESULTS

We saw a rapid and significant improvement of accuracy among novice medical students. All participants deemed the simulator as highly realistic, effective, and superior to conventional training methods.

CONCLUSION

We were able to demonstrate that building and implementing a high-fidelity simulator for one of the most important neurosurgical procedures as an effective educational and training tool is achievable in a timely manner and without extensive investments.

An Innovative Simulation Model for Microvascular Training

SUMMARY

Preclinical/clinical microsurgical training is essential for clinical practice. Therefore, various training models have been established, such as synthetic and cadaveric models. The most common limitation of these models is the lack of circulation, which limits the simulation of real intraoperative circumstances. Thus, the authors aimed to create a novel model that provides blood circulation with an extracorporeal perfusion device that they attached to rat cadavers for the reestablishment of a circulatory system. Patent blue and heparin were added to the perfusion fluid to visualize circulation and to dissolve thrombosis, and indocyanine green fluorescent imaging was applied to show the perfusion of the entire body. The femoral and brachial vessels were dissected, and an end-to-end anastomosis was performed on the femoral artery. The patency of the operated vessel was visualized with indocyanine green fluorescent imaging. Indocyanine green fluorescent imaging showed appropriate vessel patency and extremity perfusion through the anastomosis. The use of this novel rat model enables a solution for ethical problems encountered when using rats for surgical training courses. By practicing on these animal-sparing models with intact circulation, microsurgical skills can be improved. Future studies on further microsurgical techniques and vascular perfusion of organs or tumors may benefit from our model.

Trends and Innovations of Simulation for Twenty First Century Medical Education

In the last two decades there has been an enormous growth in the use of clinical simulation. This teaching-learning methodology is currently the main tool used in the training of healthcare professionals. Clinical simulation is in tune with new paradigms in education and is consistent with educational theories that support the use of experiential learning. It promotes the development of psychomotor skills and strengthens executive functions. This pedagogical approach can be applied in many healthcare topics and is particularly relevant in the context of restricted access to clinical settings. This is particularly relevant considering the current crisis caused by the COVID-19 pandemic, or when trying to reduce the frequency of accidents attributed to errors in clinical practice. This mini-review provides an overview of the current literature on healthcare simulation methods, as well as prospects for education and public health benefits. A literature search was conducted in order to find the most current trends and state of the art in medical education simulation. Presently, there are many areas of application for this methodology and new areas are constantly being explored. It is concluded that medical education simulation has a solid theoretical basis and wide application in the training of health professionals at present. In addition, it is consolidated as an unavoidable methodology both in undergraduate curricula and in continuing medical education. A promising scenario for medical education simulation is envisaged in the future, hand in hand with the development of technological advances.

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.

Baixo custo e fácil aquisição: grãos de milho no treinamento microcirúrgico

RESUMO Objetivo: desenvolver um modelo facilmente acessível para o treinamento da prática motora inicial em microcirurgia a partir da utilização de grãos de milho. Métodos: foram utilizados dez grãos de milho (Zea mays). Realizou-se um corte longitudinal de 7mm em uma das faces do grão de milho. O treinamento consistiu na realização de 4 pontos simples entre as bordas da incisão, utilizando fio de mononáilon 10-0. Os parâmetros analisados foram 1) custo do modelo; 2) tempo de montagem do sistema de teste do modelo; 3) tempo de realização dos nós; 4) distância entre os pontos. Resultados: em todos os grãos testados foi possível realizar o treinamento de sutura microcirúrgica proposto, sem dificuldade ao procedimento. O tempo médio para a realização dos 4 pontos foi de 6,51±1,18 minutos. O custo total do modelo simulatório foi de R$3,59. A distância média entre os pontos foi de 1,7±0,3mm. O modelo desenvolvido a partir de grãos de milhos apresenta custo extremamente baixo quando comparado ao uso de animais ou de simuladores de alta tecnologia. Outras vantagens são fácil disponibilidade de grãos de milho em conserva e possibilidade de serem realizados mais de quatro pontos ao longo da incisão de 7mm. Conclusão: o modelo de treinamento desenvolvido é de baixo custo, de fácil aquisição e viável para o treinamento de habilidades manuais básicas em microcirurgia.

Smartphone-based DIY home microsurgical training with 3D printed microvascular clamps and Japanese noodles

We have recently incorporated simple modifications of the konjac flour noodle model to enable DIY home microsurgical training by (i) placing a smartphone on a mug to act as a microscope with at least 3.5-5x magnification, and (ii) rather than cannulating with a 22G needle as described by others, we have found that cannulation with a 23G needle followed by a second pass with an 18G needle will create a lumen (approx. 0.83 mm) without an overly thick and unrealistic "vessel" wall. The current set-up however, did not allow realistic evaluation of anastomotic patency as the noodles became macerated after application of standard microvascular clamps, which also did not facilitate practice of back-wall anastomoses. In order to simulate the actual operative environment as much as possible, we introduced the use of 3D printed microvascular clamps. These were modified from its previous iteration (suitable for use in silastic and chicken thigh vessels) and video recordings were submitted for internal validation by senior surgeons. A "wet" operative field where the knojac noodle lumen can be distended or collapsed, unlike other non-living models, was noted by senior surgeons. With the 3D clamps, the noodle could now be flipped over for back-wall anastomosis and allowed patency testing upon completion as it did not become macerated, unlike that from clinical microvascular clamps. The perceived advantages of this model are numerous. Not only does it comply with the 3Rs of simulation-based training, it can also reduce the associated costs of training by up to a hundred-fold or more when compared to a traditional rat course, and potentially, be extended to low-middle income countries (LMICs) without routine access to microsurgical training for capacity development. That it can be utilised remotely also bodes well with the current limitations on face to-face training due to COVID restrictions and lockdowns.

MicrosimUC: Validation of a Low-Cost, Portable, Do-It-Yourself Microsurgery Training Kit

BACKGROUND

 Microsurgery depends largely on simulated training to acquire skills. Courses offered worldwide are usually short and intensive and depend on a physical laboratory. Our objective was to develop and validate a portable, low-cost microsurgery training kit.

METHODS

 We modified a miniature microscope. Twenty general surgery residents were selected and divided into two groups: (1) home-based training with the portable microscope (MicrosimUC, n = 10) and (2) the traditional validated microsurgery course at our laboratory (MicroLab, n = 10). Before the intervention, they were assessed making an end-to-end anastomosis in a chicken wing artery. Then, each member of the MicrosimUC group took a portable kit for remote skill training and completed an eight-session curriculum. The laboratory group was trained at the laboratory. After completion of training, they were all reassessed. Pre- and posttraining procedures were recorded and rated by two blind experts using time, basic, and specific scales. Wilcoxon's and Mann-Whitney tests were used to compare scores. The model was tested by experts (n = 10) and a survey was applied to evaluate face and content validity.

RESULTS

 MicrosimUC residents significantly improved their median performance scores after completion of training (p < 0.05), with no significant differences compared with the MicroLab group. The model was rated very useful for acquiring skills with 100% of experts considering it for training. Each kit had a cost of U.S. $92, excluding shipping expenses.

CONCLUSION

 We developed a low-cost, portable microsurgical training kit and curriculum with significant acquisition of skills in a group of residents, comparable to a formal microsurgery course.

Microsurgery Arena: A New Device to Develop Microsurgical Skills

Simulation in microsurgery is an important pillar of training and maintenance of surgical skills. Between learning microsurgical skills and mastering them in clinical practice, the usefulness of low-fidelity simulators for improving microsurgery skills has been well documented. Nowadays the in vivo models represent the gold standard of microsurgical training; however, their use implies difficulties and limitations. We developed a portable, low-cost, and modern device to help trainees to practice at their convenience to maintain their microsurgical suturing skills. By using CAD and 3D printer designs, we developed a "microsurgery trainer" that contains a middle section with eight projections with holes, arranged as a circle. The idea is to pass the microsuture-preferably 7/0 or 8/0 sutures-in a clockwise manner-with the needle passing from "out to in" and "in to out" through each hole. This allows the trainee to use his/her wrist to be flexible and achieve better control over the micro needle. Studies evaluating the potential of such a device in shortening the learning curve are needed and will be crucial to define whether the "microsurgery arena" will help trainees to obtain better outcomes in microsurgical practice.

Submerged vascular anastomosis. A technique for vascular suturing in experimental microsurgery

PURPOSE

To evaluate the impact of submersion of the microsurgical anastomosis suture area using saline (0.9% NaCl) in an experimental laboratory during the training of medical students and resident physicians.

METHODS

Wistar rats (n = 10) were selected to have the two femoral arteries sectioned and anastomosed end-to-end under optical magnification. They were randomly divided, so that on one side suturing was performed under submersion with saline, and the contralateral side was kept dry during the procedure. The surgical times, as well as the patency within 30 min and 72 h of the procedure, were evaluated.

RESULTS

Six male Wistar rats survived the surgical anesthetic procedure, with the average initial weight of 243.3 g and the average artery diameter of 0.86 mm, with average time of 15.67 min for the submerged technique and 20.50 min for the dry technique (p = 0.03). The failure rates were 17 and 50% for the submerged group and the dry one, respectively (p = 0.62).

CONCLUSIONS

Submerged microvascular suture does not compromise the patency of the vessel or increase the time of anastomosis. Therefore, it is a strategy that can be applied by the surgeon according to his/her technical preferences.

Effectiveness of a microsurgery training program using a chicken wing model

Microsurgical skills are essential for plastic surgeons in the modern times. Chicken wing model for microsurgery training offers an easy and cost-effective alternative to the traditional live rat model. A prospective study was conducted over a period of 6 months. Fifteen resident doctors in the department of plastic surgery were enrolled. Each of them underwent one session of microsurgery training on chicken wings (ulnar artery) every week for 15 weeks. The pre-training and post-training microvascular anastomosis were recorded and analyzed by two blinded investigators using a modification of the Structured Assessment of Microsurgery Skills (SAMS) tool. The pre- and post-training scores were compared. Twelve residents completed the requisite number of training sessions and were included in the final analysis. The mean diameter of the chicken wing ulnar artery was 1.04 mm (SD:0.11). All trainees demonstrated an improvement in the total scores. There was significant improvement in the mean scores (Pre-training: 33.46 vs. post-training: 41.42, p = 0.002). There was also a significant decrease in the total number of errors (Pre-training: 6.75 vs. post-training: 4.79, p = 0.012). However, there was no significant improvement in the average time taken to perform anastomosis (Pre-training: 58.03 mins vs. post-training: 52.51 mins, p = 0.182). We concluded that chicken wing is a useful training model for microsurgery. It helps in improving the overall microsurgical skill as well as reducing the average number of errors. This model is cost-effective, easily available, and easy to set-up. The wide assortment of vessels with varying diameters provides opportunities for training of microsurgeons of different skill levels.

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.

The Double Stitch Everting Technique in the End-to-Side Microvascular Anastomosis: Validation of the Technique Using a Randomized N-of-1 Trial

BACKGROUND

 The double stitch everting (DSE) technique, in which time is won by leaving the needle inside the vessel wall in-between stitching, is a modification of the end-to-side (ETS) anastomosis in the interest of reducing anastomosis time. This ensures proper wall eversion, intima-to-intima contact, and improved suture symmetry.

METHODS

 We designed an N-of-1 randomized trial with each microsurgeon as their own control. We included 10 microsurgeons of different levels of experience who were then asked to perform classic and DSE ETS anastomoses on the chicken leg and rat femoral models. Every anastomosis was cut and evaluated using blinded assessment. Two-way analysis of variance (ANOVA) and multivariable logistic regression were used to analyze the results and for confounder adjustment.

RESULTS

 A total of 210 anastomoses were performed, of which 177 on the chicken leg and 43 on the rat femoral artery and vein. From the 210 anastomoses, 111 were performed using the classic technique and 99 using the DSE technique. The mean anastomosis time was 28.8 ± 11.3 minutes in the classic group and 24.6 ± 12 minutes in the DSE group (p < 0.001, t-test). There was a significant reduction (p < 0.001, two-way ANOVA) in the number of mistakes when using the DSE technique (mean 5.5 ± 2.6) compared with those using the classic technique (mean 7.7 ± 3.4).

CONCLUSION

 The DSE technique for ETS anastomoses improves anastomoses times in experienced and moderately experienced microsurgeons while also improving or maintaining suture symmetry and lowering the number of mistakes.

Validated specialty-specific models for multi-disciplinary microsurgery training laboratories: a systematic review

BACKGROUND

Laboratory simulation is increasingly important for teaching microsurgical skills. Training microsurgeons of different specialties within the same simulation laboratory increases efficiency of resource use. For maximal benefit, simulations should be available for trainees to practice specialty-specific, higher-order skills. Selection of appropriate simulations requires knowledge of the efficacy and validity of the numerous described laboratory models. Here we present a systematic review of validated training models that may serve as useful adjuncts to achieving competency in specialty elements of microsurgery, and appraise the evidence behind them.

METHODS

In setting up a multi-disciplinary microsurgery training course, we performed a systematic review according to preferred reporting items for systematic reviews and meta-analyses guidelines. EMBASE, MEDLINE, Cochrane and PubMed databases were searched for studies describing validated, microscope-based, specialty-specific simulations, and awarded a level of evidence and level of recommendation based on a modified Oxford Centre for Evidence-Based Medicine classification.

RESULTS

A total of 141 papers describing specialty-specific microsimulation models were identified, 49 of which included evidence of validation. Eleven were in the field of neurosurgery, 21 in otolaryngology/head and neck surgery, two in urology/gynaecology and 15 plastic and reconstructive surgery. These papers described synthetic models in 19 cases, cadaveric animals in 10 cases, live animals in 12 cases and human cadaveric material in 10 cases.

CONCLUSION

Numerous specialty-specific models for use in the microscope laboratory are available, but the quality of evidence for them is poor. Provision of models that span numerous specialties may encourage use of a microscope lab whilst still enabling more specific skills training over a 'one-size-fits-all' approach.

Superiority of living animal models in microsurgical training: beyond technical expertise

Background

Many studies are investigating the role of living and nonliving models to train microsurgeons. There is controversy around which modalities account for the best microsurgical training. In this study, we aim to provide a systematic literature review of the practical modalities in microsurgery training and compare the living and nonliving models, emphasizing the superiority of the former. We introduce the concept of non-technical skill acquisition in microsurgical training with the use of living laboratory animals in the context of a novel proposed curriculum.

Methods

A literature search was conducted on PubMed/Medline and Scopus within the past 11 years based on a combination of the following keywords: “microsurgery,” “training,” “skills,” and “models.” The online screening process was performed by two independent reviewers with the Covidence tool. A total of 101 papers was identified as relevant to our study. The protocol was reported in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement.

Results

Living models offer the chance to develop both technical and non-technical competencies (i.e., leadership, situation awareness, decision-making, communication, and teamwork). Prior experience with ex vivo tissues helps residents consolidate basic skills prior to performing more advanced techniques in the living tissues. Trainees reported a higher satisfaction rate with the living models.

Conclusions

The combination of living and nonliving training microsurgical models leads to superior results; however, the gold standard remains the living model. The validity of the hypothesis that living models enhance non-technical skills remains to be confirmed.

Level of evidence: Not ratable.

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.

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.

Intraoperative Microvascular Complications in Autologous Breast Reconstruction: The Effects of Resident Training on Microsurgical Outcomes

BACKGROUND

 Academic medical centers with large volumes of autologous breast reconstruction afford residents hand-on educational experience in microsurgical techniques. We present our experience with autologous reconstruction (deep inferior epigastric perforators, profunda artery perforator, lumbar artery perforator, bipedicled, and stacked) where a supervised trainee completed the microvascular anastomosis.

METHODS

 Retrospective chart review was performed on 413 flaps (190 patients) with microvascular anastomoses performed by postgraduate year (PGY)-4, PGY-5, PGY-6, PGY-7 (microsurgery fellow), or attending physician (AP). Comorbidities, intra-operative complications, revisions, operative time, ischemia time, return to operating room (OR), and flap losses were compared between training levels.

RESULTS

 Age and all comorbidities were equivalent between groups. Total operative time was highest for the AP group. Flap ischemia time, return to OR, and intraoperative complication were equivalent between groups. Percentage of flaps requiring at least one revision of the original anastomosis was significantly higher in PGY-4 and AP than in microsurgical fellows: PGY-4 (16%), PGY-5 (12%), PGY-6 (7%), PGY-7 (2.1%), and AP (16%), p = 0.041. Rates of flap loss were equivalent between groups, with overall flap loss between all groups 2/413 (<1%).

CONCLUSION

 With regard to flap loss and microsurgical vessel compromise, lower PGYs did not significantly worsen surgical outcomes for patients. AP had the longest total operative time, likely due to flap selection bias. PGY-4 and AP groups had higher rates of revision of original anastomosis compared with PGY-7, though ultimately these differences did not impact overall operative time, complication rate, or flap losses. Hands-on supervised microsurgical education appears to be both safe for patients, and also an effective way of building technical proficiency in plastic surgery residents.

Novel Porcine Kidney-Based Microsurgery Training Model for Developing Basic to Advanced Microsurgical Skills

BACKGROUND

 Microsurgery training is critical to the practice of microvascular procedures in many surgical areas. However, even simple procedures require different levels of complex skills. Therefore, simulation-based surgical training, mainly in the area of vascular anastomosis, is of great importance. In this paper, we present a new microsurgery training model for the development of basic to advanced microsurgical skills.

METHODS

 Porcine kidneys were purchased from a legal butchery slaughterhouse. First, kidneys were washed with water to remove blood and clots inside vessels. Then, dissection was performed throughout the vascular pedicle from the renal arteries to the segmentary branches. Finally, the longitudinal sectioning of the kidney parenchyma was performed to expose the vessels necessary for training. Sixty end-to-end anastomoses were performed. Specific instruments and materials were used to perform anastomoses and dissections with magnification by a video system. We evaluated the diameter of vessels, time to perform anastomosis, and patency of anastomosis.

RESULTS

 There was no great anatomical variation among the porcine kidneys. The total length for dissection training was 25.80 ± 7.44 cm using the arterial and venous vessel. The average time to perform arterial anastomoses was 23.79 ± 4.55 minutes. For vessel diameters of ≤ 3, 4 to 6, and 7 to 10 mm, the average procedure times were 27.68 ± 3.39, 22.92 ± 4.12, and 20.77 ± 3.44 minutes, respectively. Regarding venous anastomosis, the average duration of the procedure was 26.17 ± 4.80 minutes, including durations of 31.61 ± 3.86, 25.66 ± 4.19, and 21.24 ± 3.79 minutes for vessel diameters of ≤ 7, 8 to 10, and >10 mm, respectively. Positive patency was achieved in all surgeries.

CONCLUSION

 The porcine kidney provides an inexpensive and convenient biological model for modeling microanastomosis with high fidelity to vascular structures.

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.