The Role of Simulation in Microsurgical Training

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.

The Role of Cadaver-Based Flap Course in Microsurgical Education and Practice Patterns of Attendees: A Survey Study

BACKGROUND

 In 2017, our institution initiated a cadaver laboratory-based course dedicated to teaching reconstructive microsurgery indications, preoperative planning, and flap dissection. The goals of this study are to describe the demographics and experience of participants/instructors and to evaluate the learning objectives and effectiveness of the course.

METHODS

 Penn Flap Course (PFC) participants were sent an anonymous survey at the inaugural PFC 2017. Then, in 2019, both instructors and participants were sent a more comprehensive survey. Surveys included questions regarding demographics, training background, experiences in practice and/or training, and course evaluation.

RESULTS

 At PFC 2017, participant response rate was 25% (12/44), and the primary reason for attending the course was to observe and learn from instructor dissections (66.7%). At PFC 2019, the response rate was 77.3% (17/22) for faculty and 73.0% (35/48) for participants. Both in 2017 and 2019, the vast majority of participants reported perceived improvement in understanding of flap dissection principles across all anatomic domains (94.3%-100%). In 2019, when asked about their background experience, the majority of participants reported comfort performing arterial and venous anastomosis without supervision (71%-77%) and being least comfortable with head and neck (H&N) microsurgery (mean comfort level: 5.2/10). Half of the participants (e.g., residents) find the presence of a microsurgery fellow at their institution useful to their educational experience. Instructors with additional fellowship training in microsurgery reported performing a higher volume of free flaps per week (7 vs. 2.3) and per year (94.2 vs. 27.8; p < 0.05 for both) and trend toward performing more H&N reconstruction (p = 0.057).

CONCLUSION

 Participants feel least comfortable with H&N microsurgical reconstruction. Surgical faculty with microsurgical fellowship training performs greater volume of microsurgical cases with a trend toward more H&N reconstruction. A cadaver/lecture-based flap course is an effective way to improve participants' perceived confidence and understanding of complex flap and microsurgical reconstructive procedures.

Cerebrospinal Fluid Leak Repair Simulation Model: Face, Content, and Construct Validation

Background

Cerebrospinal fluid leak (CSFL) repair simulation models are scarce; however, these models are valuable tools for skull base reconstruction surgery training.

Objectives

This study aims to assess the face, content, and construct validity of a CSFL repair simulation model.

Method

Eight novices (residents- PGY3) and eight experts have performed skull base reconstruction in multiple sites in twelve human cadaveric heads in simulated surgical environment. The experts completed a post-study 21-item questionnaire to assess the face and content validity. The performances of the participants were recorded and scored by two independent investigators who were blinded to the participant's level. Global Rating Scale of Operative Performance (GRSOP) and a Specific Skull Base Reconstruction Checklist (SBRC) were used to score the performances.

Results

The responses from the expert group for the 21-item questionnaire were high for all items (4.13–4.88 out of 5). The internal consistency reliability of the questionnaire and the intraclass correlation, which was derived by Cronbach’s Alpha, were 0.913 and 0.941 respectively. Differences in construct validity between the two groups were statistically significant for both the GRSOP and SBRS (P-value < 0.001).

Conclusion

We demonstrated the face, content, and construct validity of the CSFL repair simulation model, which facilitates the acquisition of technical skills necessary for skull base reconstruction surgery. The model includes realistic features that make it useful in educational courses.

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.

Effects of a Simulation-Based CPR Training Program on Knowledge, Performance, and Stress in Clinical Nurses

BACKGROUND

Rapid and accurate cardiopulmonary resuscitation (CPR) performed by clinical nurses plays an important role in increasing the survival rate of cardiac arrest patients in the hospital.

PURPOSE

This study examined the effects of a simulation-based CPR training program on knowledge, performance, and stress of CPR in clinical nurses.

METHOD

A quasi-experimental pretest-posttest control group design was used. Study participants included 60 clinical nurses (experimental group, n = 30, and control group, n = 30) in a general hospital in Seoul, South Korea. A 4-hour simulation-based CPR training program was conducted. Measures included the knowledge scale and performance scale from the Korean Association of Cardiopulmonary Resuscitation and the Post Code Stress Scale in Korean.

RESULTS

The simulation-based CPR training program significantly improved CPR knowledge (t = 4.664, p < .001) and performance (t = 4.940, p < .001), and decreased stress (t = -5.832, p < .001) in clinical nurses.

CONCLUSION

These findings indicate a simulation-based CPR training program was effective in improving knowledge and performing CPR, as well as in decreasing stress of CPR in clinical nurses. [J Contin Educ Nurs. 2020;51(5):225-232.].

A Low-Cost 3D-Printed Tool with Multiaxial/Angular Vessel Orientation for Microvascular Anastomosis Training

Background:

Microsurgical anastomosis is a technically demanding skill. The most difficult part of the learning process was in achieving the necessary orientation and dexterity. In this project, we adopted computer-aided design and desktop 3D-printing in the development of an affordable training model with different levels of vessel orientation and angulation.

Methods:

The training model was designed using CAD software (Rhino3D). The models were then 3D-printed with a thermoplastic polyurethane (TPU 95A) semiflexible filament on a desktop fused deposition modeling, Ultimaker 2 + 3D printer.

Results:

The printed training tool was assembled by fitting the ball-and-socket mechanism between two parts having an overall round table top with integrated vascular clamps. Trial with synthetic and nonliving animal blood vessels shows the utility of the clamps in holding the vessels within the working space. By rotating the top part, a multiaxial vessel orientation from 0 to 360 degrees was achieved. The top part was also capable of multiangular orientation of the vessels (±30 degrees) regardless of its axial orientation during vessel anastomosis. For the 3D-printing process, the average printing time was about 3.5 hours with a cost of 1.3$ per material.

Conclusions:

The utility of desktop 3D printing represents an affordable modality in microsurgical training. The designed model is capable of providing a trainee with multiaxial and multiangular vessel orientation during the anastomosis process. To our knowledge, the adoption of this technology in the field of microsurgery training has never been investigated before.

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

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

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

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

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

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

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Stereoscopic versus monoscopic displays: Learning fine manual dexterity skills using a microsurgical task simulator

We investigated the learning of fine manual dexterity with a microsurgical instrument and a new simulator in a context of microsurgery. 30 subjects were divided into two groups. One (3D group) interacted with a stereoscopic and the other (2D group) with a monoscopic display. Visual information for the displays was captured from a surgical stereomicroscope. In 20 trials, both groups performed the repetitive tasks of picking up small rods from a funnel-shaped cavity and placing them outside. In analysing learning curves, we found that the initial learning process for hand-eye coordination is easier with a 3D display, and that performance persists at a higher level of proficiency than with the 2D display option. Thus stereoscopic displays can be especially beneficial for novices, for those learning new procedures, or for providing orientation to operators facing a new or altered spatial situation. Simulators with few reliefs or spatial textures should not be used for comparison between 3D and 2D viewing conditions.

Silicone-based simulation models for peripheral nerve microsurgery

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Transpedicular Approach on a Novel Spine Simulator: A Validation Study

OBJECTIVE

The popularity of simulation in the medical field has increased dramatically over the last decades. However, the majority of studies focused on laparoscopic or other endoscopic procedures. In this study, participants performed an image-guided surgery task on a novel spine simulator. Face, content, construct, and concurrent validity were examined.

DESIGN

A surgical access through both pedicles (transpedicular) into the vertebral body of artificial L3 vertebrae was performed. Questionnaires, a simulation-based performance score, and a specialist rating were used to evaluate the various forms of validity.

SETTING

Klinikum Wels-Grieskirchen, Wels, Austria; tertiary hospital PARTICIPANTS: According to their expertise in image-guided surgery and pedicle tool insertions, 43 participants were subdivided into 3 groups: 22 novices, 12 intermediates, and 9 experts.

RESULTS

Of the novice group, the vast majorities were impressed with the attractiveness and the general appearance of the simulator. The majority of intermediates (92%) and experts (89%) would recommend the simulator to others. According to a simulation-based performance score, experts performed significantly better than novices (p = 0.001, d = 1.52) and intermediates (p = 0.01, d = 1.26). The association between the simulation-based performance score and the specialist rating was strong (R = 0.86, p < 0.01).

CONCLUSIONS

The novel spine simulator provides an applicable tool for the training of image-guided surgery skills in a realistic design. Its simulation-based assessment score classifies different levels of expertise accurately.