A synthetic model for microsurgical training: a surgical contribution to reduce the number of animal experiments

Implementación de las escalas de evaluación formativa OSATS en habilidades técnicas aplicadas en el laboratorio de microcirugía

Introducción: la simulación como estrategia de aprendizaje activo se ha constituido en una herramienta centrada en el estudiante, en la construcción de aprendizajes en entornos seguros, la creación y perfección de sus habilidades técnicas. Es allí donde la evaluación forma parte vital del proceso que busca identificar aprendizajes reales. Los OSATS son herramienta evaluativa en el área quirúrgica, implementable a los programas en microcirugía y escalas de desempeño en los modulos básicos. Metodología: estudio descriptivo, corte transversal y doble ciego; incluye 34 estudiantes de especilidades quirúrgicas quienes fueron evaluados mediante los OSATS para los módulos finales; modulo 1: disección vascular, M2: ejecución de sutura de puntos independientes, M3: ejercicios revascularización, al finalizar la materia los estudiantes evaluaron la implementación de esta metodología en evaluación por medio de una encuesta de satisfacción. Resultados: la evaluación del diseño de la guía práctica tipo OSATS por los estudiantes fue satisfactoria con 88,2 %,  al evaluar la actividad de disección y sutura en microcirugía la consideran de gran utilidad con 88,2 %, para los ejercicios de anastomosis y revascularización con una aprobación del 79.5 %, aplicabilidad práctica y calidad de los ejercicios mediante guías de evaluación OSATS 94.2 % de aceptación. Discusión: las escalas OSATS son un intrumento útil, valido y objetivo para el modelo de evaluación por competencias en habilidades técnicas, implementable en los modelos de enseñanza en simulación, contando con una confiabilidad, validez de contenido y de constructo, aplicable en los programas de microcirugía con una percepción positiva por los estudiantes a lo largo de su implementación.

Simulation in Upper and Lower Limb Trauma Skill Acquisition: A Review

SUMMARY STATEMENT

This review aimed to explore the published evidence with regard to the types and composition of both full- and part-task trainers to teach surgeons extremity exploration procedures in limb trauma management. Studies were included if they reported the development and/or validation of synthetic or virtual task trainers. Studies were evaluated to determine their derivation, usability, and clinical utility.A total of 638 citations were identified and 63 satisfied the inclusion criteria. Twenty-five articles addressed simulator validation and 36 addressed level of learning achieved with simulator engagement. Two studies described a dedicated limb simulator. Simulators were developed to repair limb structures including skin (n = 15), tendon (n = 7), nerve (n = 1), fascia (n = 1), muscle (n = 1), vascular (n = 24), and bone (n = 11). Considerations such as material fidelity, learning outcomes, cost or reusability, validity, and effectiveness are inconsistently reported. Future studies should address design standards for the effective production of synthetic or virtual simulators for limb trauma management.

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 training course for clinicians and scientists: a 10-year experience at the Münster University Hospital

BACKGROUND

Microsurgical techniques are an important part of clinical and experimental research. Here we present our step-by-step microsurgery training course developed at the Münster University Hospital. The goal of this course was to create a short, modular curriculum with clearly described and easy to follow working steps in accordance with the Guidelines for Training in Surgical Research in Animals by the Academy of Surgical Research.

METHODS

Over the course of 10 years, we conducted an annual 2.5 day (20 h) microsurgical training course with a total of 120 participants.

RESULTS

Prior to the course, 90% of the participants reported to have never performed a microanastomosis before. During the 10 years a total of 84.2% of the participants performed microanastomoses without assistance, 15% required assistance and only 0.8% failed.

CONCLUSIONS

Our step-by-step microsurgery training course gives a brief overview of the didactic basics and the organization of a microsurgical training course and could serve as a guide for teaching microsurgical skills. During the 2.5-day curriculum, it was possible to teach, and for participants to subsequently perform a microsurgical anastomosis. The independent reproducibility of the learned material after the course is not yet known, therefore further investigations are necessary. With this step-by-step curriculum, we were able to conduct a successful training program, shown by the fact that each participant is able to perform microvascular anastomoses on a reproducible basis.

A novel three-in-one silicone model for basic microsurgery training

Background

Microsurgery simulation is an important aspect of surgical training. Animal models have been widely used in simulation training, but they have some limitations including ethical restrictions, cost and availability. This has led to the use of synthetic models that can reduce reliance on animals in line with the 3R (refinement, reduction and replacement) principles. The aim of this paper was to evaluate the face validity of Surgitate™ three-in-one (artery, vein and nerve) silicone model.

Methods

Fourteen candidates performed one end-to-end anastomosis on artery, vein and nerve. The face validity of the vessel was assessed via questionnaires detailing their previous microsurgical experience and their feedback of using this model using the Likert scale. Data management and analysis were performed using IBM SPSS software (25.0).

Results

Participants tended to value this model in the earlier stages of microsurgical training particularly in the acquisition of basic microsurgical skills. It could be particularly useful in enhancing suturing skills as a replacement or reduction in the use of chicken models. The model has some drawbacks preluding its utilization into more advanced stages of surgical training. Further studies are needed to validate the model using more objective measures.

Conclusion

We present a novel synthetic model that can be potentially introduced to early stages of microsurgery training. The model would be ideal to meet the 3R principles of the use of animal models and as an alternative to the commonly used synthetic models.

Level of evidence: Not ratable.

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.

Nonbiological Microsurgery Simulators in Plastic Surgery Training: A Systematic Review

BACKGROUND

Simulation has gained notable recognition for its role as an effective training and assessment modality in the present era of competency-based medical education. Despite the well-documented efficacy of both live and cadaveric animal models, several ethical, financial, and accessibility issues persist with their use. Lower fidelity nonbiological simulators have gained recognition for their ability to circumvent these challenges. This systematic review reports on all prosthetic and virtual reality simulators in use for microsurgery training, with an emphasis on each model's complexity, characteristics, advantages, disadvantages, and validation measures taken.

METHODS

A systematic search was performed using the National Library of Medicine (PubMed), MEDLINE, and Embase databases. Search terms were those pertaining to prosthetic and virtual reality models with relevance to microsurgical training in plastic surgery. Three independent reviewers evaluated all articles retrieved based on strict inclusion and exclusion criteria.

RESULTS

Fifty-seven articles met the inclusion criteria for review, reporting on 20 basic prosthetic models, 20 intermediate models, 13 advanced models, and six virtual reality simulators.

CONCLUSIONS

A comprehensive summary has been compiled of all nonbiological simulators in use for microsurgery training in plastic surgery, demonstrating efficacy for the acquisition and retention of microsurgical skills. Metrics-based validation efforts, however, were often lacking in the literature. As plastic surgery programs continue to innovate, ensure accountability, and safely meet today's training standards, prosthetic simulators are set to play a larger role in the development of a standardized, ethical, accessible, and objectively measurable microsurgery training curriculum for the modern-day plastic and reconstructive surgery resident.

Portable model for vasectomy reversal training

OBJECTIVES

to validate an experimental non-animal model for training of vasectomy reversal.

MATERIALS AND METHODS

The model consisted of two artificial vas deferens, made with silicon tubes, covered by a white resin, measuring 10 cm (length) and internal and external diameters of 0.5 and 1.5 mm, respectively. The holder of the ducts is made by a small box developed with polylactic acid, using a 3D print. The objective of the invention is to simulate the surgical field of vasovasostomy, when the vas deferens are isolated from other cord structures. For validation, it was verified the acquisition of microsurgical skills during its use, in a capacitation course with 5 urology residents from a Hospital of the region. Along the training sessions, it was analyzed the time (speed) of microsurgical sutures, and quantification of the performance using a checklist. Collected data were analyzed using de BioEstat®5.4 software.

RESULTS

Medium time for the completion of microsurgical sutures improved considerably during the course, and reached a plateau after the third day of training (p=0.0365). In relation to the checklist, it was verified that during capacitation, there was significant improvement of the scores of each participant, that reached a plateau after the fourth day of training with the model (p=0.0035).

CONCLUSION

The developed model was able to allow the students that attended the course to gain skills in microsurgery, being considered appropriate for training vasectomy reversal.

A Simple and Cost-effective Method for Practicing Microsurgery

Practicing microsurgery is usually expensive. This is because living animals, artificial vessels, and synthetic models are not always available. Here, I report a simple and cost-effective method to practice microsurgical techniques by using sterile gloves.

New Alternative to Animal Models for Surgical Training

Laboratory training models are essential for developing and refining surgical skills, especially in microsurgery. A perfect training model is the one that can provide the same situation during surgery, in the same anatomy; the closer to live surgery the model is, the greater the benefit. The lack of an accurate vascular model has sometimes necessitated the use of live models when bleeding, and vascular liquid filling is desired for optional learning. We developed a new model utilising human cadavers that can replace the use of live anaesthetised animals for surgical training. The vessels in a cadaveric specimen were connected to artificial blood reservoirs. The arterial side was connected to a pump to provide pulsating pressure inside the arteries, while the venous side was kept under static pressure that applied to the reservoir. This method provides a condition that simulates live surgery in terms of bleeding, pulsation and liquid filling of the vascular tree. It is an excellent alternative model and can be applied to the whole cadaver or to a particular cadaveric specimen (head, arm, leg) or to an isolated organ. It is distinctive and of a great practical value for training in a wide range of surgical procedures, Utilising this technique could forever eliminate the use of live anaesthetised animals for surgical training. The model and device are patent pending application no. 10/339,053.

The Role of Simulation in Microsurgical Training

Simulation has been established as an integral part of microsurgical training. The aim of this study was to assess and categorize the various simulation models in relation to the complexity of the microsurgical skill being taught and analyze the assessment methods commonly employed in microsurgical simulation training. Numerous courses have been established using simulation models. These models can be categorized, according to the level of complexity of the skill being taught, into basic, intermediate, and advanced. Microsurgical simulation training should be assessed using validated assessment methods. Assessment methods vary significantly from subjective expert opinions to self-assessment questionnaires and validated global rating scales. The appropriate assessment method should carefully be chosen based on the simulation modality. Simulation models should be validated, and a model with appropriate fidelity should be chosen according to the microsurgical skill being taught. Assessment should move from traditional simple subjective evaluations of trainee performance to validated tools. Future studies should assess the transferability of skills gained during simulation training to the real-life setting.

Frankfurt microsurgery course: the first 175 trainees

Introduction

Microsurgery courses, taught external to surgical training programs, are essential for acquiring the high level of technical skill required for clinical proficiency.

Methods

The Frankfurt microsurgery course is a 5-day, intensive course that teaches arterial and venous anastomosis using end-to-end, end-to-side, one-way-up, continuous-suture, and vessel graft techniques. During the course, the instructor records the level of skill (in-course data) achieved by each trainee by assessing anastomosis completion and patency. Demographic information is also collected. Post-course trainees are invited to complete an online survey (post-course data) to get their opinions of the courses’ effectiveness.

Results

The in-course “skill achievement” and post-course “course effectiveness” data are presented below. In-course data: 94.8 and 59.9% of participants completed patent end-to-end arterial and venous anastomoses, respectively, while 85.4% performed a patent end-to-side anastomosis. 96.1 and 57.1% of participants who attempted arterial and venous anastomoses using the one-way-up technique were successful, as were 90.9% of those attempting continuous-suture technique. Patent venous grafts were performed by 54.7% of participants.

Post-course data

All respondents indicated significant improvement of their microsurgical skills after taking the course. 66.7% of respondents considered the full-time presence of the instructor to be the most valuable aspect of the course. All respondents would highly recommend the course to colleagues.

Conclusion

The microcourse significantly increased trainees’ clinical microsurgery skills, confidence, and the number of clinical cases they perform. Of all the anastomosis techniques taught, venous anastomosis and grafting were the most difficult to learn. The presence of a full-time experienced instructor was most important.

Twelve tips for postgraduate or undergraduate medics building a basic microsurgery simulation training course

Microsurgery is used in a variety of surgical specialties, including Plastic Surgery, Maxillofacial Surgery, Ophthalmic Surgery, Otolaryngology and Neurosurgery. It is considered one of the most technically challenging fields of surgery. Microsurgical skills demand fine, precise and controlled movements, and microsurgical skill acquisition has a steep initial learning curve. Microsurgical simulation provides a safe environment for skill acquisition before operating clinically. The traditional starting point for anyone wanting to pursue microsurgery is a basic simulation training course. We present twelve tips for postgraduate and undergraduate medics on how to set up and run a basic ex-vivo microsurgery simulation training course suitable for their peers.

Microsurgical Simulation Exercise for Surgical Training

OBJECTIVE

Initial training for orthopedic surgical residents (postgraduate years 1-5) in microsurgery using the turkey wing model and evaluation of their proficiency.

DESIGN

Residents were given a questionnaire on their comfort level with microsurgery and microsurgical knowledge, followed by a lecture on the subject. They watched a surgical dissection and repair of the turkey wing's neurovasculature. Residents performed the dissection and repairs of the artery, vein, and nerve. A postquestionnaire was administered following the simulation exercise. Their performances on repairs were graded and results compared by academic year.

SETTING AND PARTICIPANTS

A total of 21 orthopedic surgery residents were recruited from Stony Brook University Medical Center, Stony Brook, NK.

RESULTS

This training activity resulted in significant improvements in both microsurgical knowledge (41%) and comfort (37%). Senior residents scored significantly higher than juniors on 6 microsurgical parameters. The largest effect was in nerve repair showing 4 parameters that differed significantly between groups.

CONCLUSION

Microsurgical techniques require extensive training to master. The turkey wing model for repair of the artery, vein, and nerve represents a realistic simulation of a human hand artery, vein, and nerve. It provides an inexpensive method for residents to practice on real tissue for improving microsurgical technique.

The rat model in microsurgery education: classical exercises and new horizons

Microsurgery is a precise surgical skill that requires an extensive training period and the supervision of expert instructors. The classical training schemes in microsurgery have started with multiday experimental courses on the rat model. These courses have offered a low threat supervised high fidelity laboratory setting in which students can steadily and rapidly progress. This simulated environment allows students to make and recognise mistakes in microsurgery techniques and thus shifts any related risks of the early training period from the operating room to the lab. To achieve a high level of skill acquisition before beginning clinical practice, students are trained on a comprehensive set of exercises the rat model can uniquely provide, with progressive complexity as competency improves. This paper presents the utility of the classical rat model in three of the earliest microsurgery training centres and the new prospects that this versatile and expansive training model offers.

Quality assessment of a new surgical simulator for neuroendoscopic training

Object

Ideal surgical training models should be entirely reliable, atoxic, easy to handle, and, if possible, low cost. All available models have their advantages and disadvantages. The choice of one or another will depend on the type of surgery to be performed. The authors created an anatomical model called the S.I.M.O.N.T. (Sinus Model Oto-Rhino Neuro Trainer) Neurosurgical Endotrainer, which can provide reliable neuroendoscopic training. The aim in the present study was to assess both the quality of the model and the development of surgical skills by trainees.

Methods

The S.I.M.O.N.T. is built of a synthetic thermoretractable, thermosensible rubber called Neoderma, which, combined with different polymers, produces more than 30 different formulas. Quality assessment of the model was based on qualitative and quantitative data obtained from training sessions with 9 experienced and 13 inexperienced neurosurgeons. The techniques used for evaluation were face validation, retest and interrater reliability, and construct validation.

Results

The experts considered the S.I.M.O.N.T. capable of reproducing surgical situations as if they were real and presenting great similarity with the human brain. Surgical results of serial training showed that the model could be considered precise. Finally, development and improvement in surgical skills by the trainees were observed and considered relevant to further training. It was also observed that the probability of any single error was dramatically decreased after each training session, with a mean reduction of 41.65% (range 38.7%–45.6%).

Conclusions

Neuroendoscopic training has some specific requirements. A unique set of instruments is required, as is a model that can resemble real-life situations. The S.I.M.O.N.T. is a new alternative model specially designed for this purpose. Validation techniques followed by precision assessments attested to the model's feasibility.

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

Microsurgery has expanded the scope of many surgical specialties and is evolving into an integral part of training programmes. The complexity of microsurgery requires considerable time and resources for adequate training and practice. This article reviews the validation of microsurgical models for microsurgery training and competence.

Training protocol for feline renal transplantation, using rat vascular anastomosis

Renal transplantation (RTx) has been a potential treatment for renal failure in pet cats. We developed a training protocol for the microsurgical skills required for feline RTx using rat vessels, which are the same size as the feline renal artery and vein. Using interrupted sutures, the transected abdominal aorta was reestablished in an end-to-end fashion. Venous anastomosis was performed with a continuous running suture in an end-to-side fashion between the portal vein and inferior vena cava. In the arterial anastomotic model, technical errors were checked by postoperative hemorrhaging. Those failures in the venous anastomotic model, technical errors were confirmed by the rat's death. Histological examinations of the epithelialization at the anastomotic site were evaluated in both groups. After training, nine cases of feline RTx were performed safely, using an adequate microsurgical technique.

Microsurgical training curriculum for learning kidney and liver transplantation in the rat

During the education of the next generation of scientists in experimental research, careful instruction in surgical techniques is of major importance. This applies in particular to complicated microsurgical models, which require a structured teaching concept with clearly laid-down working steps and adequate didactic resources. Transplantations in rats are undoubtedly among the most difficult models in experimental surgery. Because completely sutured orthotopic liver transplantation and kidney transplantation have been practiced for many years in our Surgical Research Unit, techniques must be transmitted to future generations. A microsurgical training program has been set up with the aim of being efficient, transparent, and motivating. Simply learning-by-doing in the sense of "laissez-faire" is ineffective and costly. Our training program is based on "three-phase didactics," in which the learning targets are presented in sequence and are clearly defined. This report is intended to give a brief overview of the principal transplantation models and to serve as a guide for teaching these models.

Microsurgical training course for clinicians and scientists at a German University hospital: A 10-year experience

Microsurgical techniques are being increasingly applied in almost all surgical disciplines. However, the opportunities to learn these skills in a structured course are rare. We have conducted a 5-day microsurgical training course on a yearly basis since 1991. The course follows step-by-step training, starting with nonvital models for vascular and nerval microanastomoses. As the participants improve, exercises on laboratory animals are offered to close the gap between nonliving models and the clinical situation. Lectures provide theoretical and clinical background information. Clinical and experimental applications can be witnessed and practiced in a second part of the course. With this step-by-step curriculum, we conduct a successful training program, e.g., each participant is able to perform microvascular and nerval anastomoses on a reproducible basis. The organization, program, and execution of the training course are presented, together with an evaluation of the course concept by the participants concerning expectations, learning success, and level of satisfaction.

Non-vital, prosthetic, and virtual reality models of microsurgical training

Many microsurgical training models exist. These can be broadly classified into living and non-living. The latter type can be further sub-classified into non-vital, prosthetic, and virtual reality models. We review each model within these sub-groups with reference to the ideal properties of a training model. The most important attribute of any model is that the skills acquired from it must translate efficiently into microsurgical skill in the clinical situation. We believe that non-vital and prosthetic models are an important complement to living ones in training and maintaining the skills of all microsurgeons. As virtual reality technology improves, virtual models may succeed the rat as the microsurgical training tool of choice.

Learning curve of microvascular venous anastomosis: a never ending struggle?

In this study, a simple protocol based on the rat femoral venous anastomosis was established to provide a quantitative representation of the progress. The learning curve is based on the patency rate in each consecutive group of five anastomoses. Two groups of surgeons were observed. The inexperienced group encountered a tough time in the first 25 anastomoses. However, the progress was fast and is represented by the steep slope of the curve. A plateau was reached whereby the avearge patency rate matches that of the experienced group. As expected, there was no learning curve for the experienced group. Despite every effort to attempt to maintain a perfect 100% patency on this model, the best achievable patency was only 88%. The results and its implication are discussed.