High Fidelity Microsurgical Simulation: The Thiel Model and Evaluation Instrument

The Influence of Inset and Shaping of Abdominal-Based Free Flap Breast Reconstruction on Patient-Reported Aesthetic Outcome Scores-A Systematic Review

Background: Nowadays, multimodal cancer therapy results in very high survival rates of early-stage breast cancer and microsurgical flap-based breast reconstruction has become safe and reliable, with gradually increasing demand because of its durable and aesthetically pleasing results. This study aimed to explore the impact of different flap shaping and inset techniques on patient-reported outcome measures (PROMs) with regard to the aesthetic result in abdominal flap-based breast reconstruction. Methods: A systematic review was performed screening Pubmed, Cochrane Library and Web of Science for original articles reporting flap inset strategies, concomitantly providing PROMs on the aesthetic result. Results: Of 319 studies identified, six met the inclusion criteria. The studies described different flap rotation options according to the patient's morphology, different inset planes, and avoidance of the monitoring skin paddle, and suggested that a higher flap-to-mastectomy mass ratio was associated with better aesthetic results. In two comparative studies, according to the PROMs (BREAST-Q, Likert scale) and independent observer judgement, both higher patient satisfaction and superior aesthetic results were observed with the newly described techniques. Conclusions: Emphasis on the aesthetic outcome in terms of breast shape and symmetry, providing an individualized approach of flap inset, considering the contralateral breast's shape and volume, results in higher satisfaction scores.

Training in microvascular anastomosis - A randomized comparative study between chicken thigh specimen and live rat

Training in microsurgical techniques on live rats is the gold standard, but raises ethical issues related to animal welfare and cost. The aim of this study was to compare acquisition of microsurgical techniques with primary training on chicken thigh specimens. Seventy six students were randomly assigned: 23 to exclusive rat training and 53 to primary chicken-leg training. Both groups were then evaluated on aortic suture and jugular aortic bypass surgery in live rats. The primary criterion for successful anastomosis was the patency test. The survival of the rat, the number of severe vascular wounds and the quality of the dissection were also assessed. Aortic anastomoses were of significantly better quality in the chicken group (p = 0.041). There was no significant difference in the number of serious injuries, rat mortality, or quality of dissection (p > 0.05). For jugular aortic bypass surgery, dissection quality (p = 0.02) and patency test (p = 0.05) were better in the chicken-leg group. There was no significant difference in number of severe wounds or rat mortality (p > 0.05). Students who started their microsurgical training on a chicken leg did not perform worse than those with exclusive live rat training. Initial training on chicken thigh specimens seems to be a reliable alternative to training on live models. LEVEL OF EVIDENCE: Level II - Randomized controlled trial.

Are Plastic Surgery Trainees Accurate Assessors of Their Own Microsurgical Skill?

Background

Microsurgery is a technically demanding surgical discipline with a steep learning curve. Trainees have faced several difficulties due to less hands-on theater time and pandemic-related limits on access to technical training. To overcome this, trainees engaged in self-directed training, which requires an accurate self-assessment of skill. This study aimed to assess the ability of trainees to accurately self-assess their performance while performing a simulated microvascular anastomosis.

Methods

Novice and specialist plastic surgery trainees performed a simulated microvascular anastomosis on a high-fidelity chicken femoral vessel model. Each participant objectively rated the quality of their anastomosis using the Anastomosis Lapse Index (ALI). Two expert microsurgeons subsequently blindly rated each anastomosis. To determine the accuracy of self-evaluation, self-scores and expert-scores were compared using a Wilcoxon signed-rank test.

Results

Twenty-seven surgical trainees completed the simulation, with a mean time to completion (TTC) of 40.3 minutes (range 14.2-106.0 minutes). For the entire cohort, the median ALI self-score was 4 (range 3-10), while the median ALI expert-score was 5.5 (range 2.5-9.5). There was a significant difference between the ALI self-score and the expert-score (p<0.001). When grouped by experience level, there was no significant difference between self-score and expert-score within the specialist group, while there was a significant difference within the novice group (p=0.001).

Conclusion

These findings suggest that specialist trainees are accurate assessors of their own microsurgical skills, but novice trainees tend to overestimate their technical skills. While novice trainees can engage in independent self-directed microsurgical training, they should seek expert feedback to ensure targeted training.

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.

Thiel embalming in neonates: methodology and benefits in medical training

Current teaching and training methods for surgical techniques in the pediatric population involve artificial models (manikins), animals or adult human cadavers embalmed using various techniques. We found no references in the literature concerning the use of the Thiel method in the pediatric population. The aim of this study, therefore, was to assess the viability of using pediatric human cadavers embalmed through Thiel’s technique and to compare them with standard pediatric manikins. After donation of a 24-week stillborn, the Thiel technique was carried out for fixation following the usual protocol. A video recording with eye-tracking glasses was used to perform an examination, and techniques. The same procedures were conducted on a pediatric manikin. Medical students, medical residents and physicians were asked to respond to questions in an online survey after being shown the video. A total of 92 responses were obtained. The Thiel-embalmed stillborn was assessed as superior to the manikin in all items. Our study confirmed that this technique is feasible even with extremely small donors. The value of this form of preservation for medical training is not widely known though it is receiving increasing interest. Our results show that Thiel fixation in pediatrics is clearly more highly valued than a manikin and offers great potential. This innovative application of the Thiel method in the pediatric population is technically possible. It poses no additional difficulties and is very positively assessed for undergraduate and postgraduate teaching.

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.