Simulation-based Surgical Training Research Articles

807 Reliability of Simulation-Based Assessment of Surgical Technical Skills

Abstract Aim To examine the reliability of surgical trainees’ assessment data from a structured simulation training and assessment programme. Method The General Surgical Skills Programme is a simulation-based surgical training programme integrated within the clinical training pathway for surgical trainees across London. It is tailored to each trainee’s level of training and subspecialty. The ‘Junior’ pathway involves nine training sessions and one assessment session performing three procedures (Inguinal hernia [IH], laparoscopic cholecystectomy [LC] and small bowel anastomoses [SBA]). Within the scope of the Programme, skills assessment data collection was initiated in 2012. Data collected includes demographics and training data (grade/subspecialty/case numbers). Each procedure is assessed by two consultant surgeons using two procedure specific assessment tools, a visual analogue scale (VAS) and competency assessment tool (CAT). Reliability analyses were performed using SPSS for ‘Junior’ data over a four-year period. Results In total, 355 surgical trainees (Male = 199, Female = 154, Missing = 2) were assessed from 2014 to 2017 (2014 n=105; 2015 n=92; 2016 n=89; 2017 n=69). Both assessment tools showed satisfactory inter-item reliability (IH-CAT α=.794-.903, LC-CAT α=.837–910, IH-VAS α=.851-.991, LC-VAS α=.831-.986, SBA-VAS α=.778-.984). Inter-rater reliability, ICC (1,2), was good to poor across all tools. (IH-CAT .345-.510, IH-VAS .243-.600, LC-CAT .271-.766, LC-VAS .157-.678, SBA-VAS .225-.278). Conclusions The assessment tools used within the Programme both demonstrate satisfactory inter-item reliability. Inter-rater reliability is variable, highlighting a potential utility for assessor training within the Programme.

Abstract 3009: Progressive Structured Simulation-based Surgical Training Program (PROCESS) - Open Vascular Surgery: Study Protocol For A Cross-over, Randomized, Double-blinded Clinical Trial.

Objective: Vascular surgery has been directed towards endovascular approaches; however, not all patients qualify for these procedures. Open vascular surgery (OVS) remains an alternative, demanding a steep learning curve. Exposure to these procedures has declined resulting in a lack of standardization in acquiring OVS skills. Simulation is a solution to this challenge. However, in OVS, there is scarce evidence for structured programs. The measurement of surgical skills is based on objectively assessable subjective tools; yet, they have limitations as evaluators may introduce inherent individual biases. We aim to compare the effectiveness of technical surgical competencies acquisition between a structured progressive simulation-based training program and isolated experience-based training in OVS. Methods: We will conduct a randomized double-blind crossover clinical trial. A control sequence and an intervention sequence of three subgroups with different exposure levels to the simulation program are proposed using 3D printed models. Group 1: open abdominal aortic repair (AAOR), Group 2: vascular anastomosis (VA) and AAOR, and Group 3: specific micro-surgical skills, VA and AAOR. Surgical residents of general, vascular, or cardiovascular surgery programs will be included. Sample size calculation resulted in 45 participants, 15 in each group. Double blinding will involve participants and external evaluators. Randomization will occur in block randomization and permuted block randomization. Results: We anticipated that the structured and progressive simulation-based training program objectively enhances technical surgical competencies. We expect to determine a significant difference in the acquisition of technical surgical competencies based on the progression through different modules within the program and validate the reliability of an assessment tool based on objective metrics for technical surgical competencies in OVS. Conclusion: We hope this initiative will impact the formation of future vascular surgeons, complementing experience-based training with simulation-based programs in OVS. Ensuring that the trainee obtains all the necessary tools to perform OVS and standardize an objective assessment evaluation method.

Stress responses in surgical trainees during simulation-based training courses in laparoscopy

BackgroundSimulation-based training courses in laparoscopy have become a fundamental part of surgical training programs. Surgical skills in laparoscopy are challenging to master, and training in these skills induces stress responses in trainees. There is limited data on trainees’ stress levels, the stress responses related to training on different laparoscopic simulators, and how previous experiences influence trainees’ stress response during a course. This study investigates physiologic, endocrine and self-reported stress responses during simulation-based surgical skills training in a course setting.MethodsWe conducted a prospective observational study of trainees attending basic laparoscopic skills training courses at a national training centre. During the three-day course, participants trained on different laparoscopic simulators: Two box-trainers (the D-box and P.O.P. trainer) and a virtual reality simulator (LAPMentor™). Participants’ stress responses were examined through heart rate variability (HRV), saliva cortisol, and the State Trait Anxiety Inventory-6 (STAI-6). The correlation between previous laparoscopic experiences and stress response measurements was explored.ResultsTwenty-four surgical trainees were included in the study. Compared to resting conditions, stress measures were significantly higher during simulation-training activity (the D-box (SDNN = 58.5 ± 23.4; LF/HF-ratio = 4.58 ± 2.71; STAI-6 = 12.3 ± 3.9, P < 0.05), the P.O.P trainer (SDNN = 55.7 ± 7.4; RMSSD = 32.4 ± 17.1; STAI-6 = 12.1 ± 3.9, P < 0.05), and the LAPMentor™ (SDNN = 59.1 ± 18.5; RMSSD = 34.3 ± 19.7; LF/HF-ratio = 4.71 ± 2.64; STAI-6 = 9.9 ± 3.0, P < 0.05)). A significant difference in endocrine stress response was seen for the simulation-training activity on the D-box (saliva cortisol: 3.48 ± 1.92, P < 0.05), however, no significant differences were observed between the three simulators. A moderate correlation between surgical experience, and physiologic and endocrine stress response was observed (RMSSD: r=-0.31; SDNN: r=-0.42; SD2/SD1 ratio: r = 0.29; Saliva cortisol: r = 0.46; P < 0.05), and a negative moderate correlation to self-reported stress (r=-0.42, P < 0.05).ConclusionTrainees have a significant higher stress response during simulation-training compared to resting conditions, with no difference in stress response between the simulators. Significantly higher cortisol levels were observed on the D-box, indicating that simulation tasks with time pressure stress participants the most. Trainees with more surgical experience are associated with higher physiologic stress measures, but lower self-reported stress scores, demonstrating that surgical experience influences trainees’ stress response during simulation-based skills training courses.

Simulation-Based Training in Basic Surgical Skills: Experiences From a Repeat Cross-Sectional Study in Saudi Arabia

Introduction The conventional surgical apprenticeship has been challenged by patient safety concerns, cost of lengthy operation, and surgical complications. Simulation-based training (SBT) has emerged as a realistic option for surgical skills acquisition outside the operating room (OR). The study aimed to document our experience in implementing SBT to acquire basic surgical skills, offered as an educational course, known as the Basic Surgery Skill Course (BSSC). Methods This was a repeated cross-sectional study conducted between January 2017 and December 2019 at King Abdulaziz University Hospital (KAUH) in Saudi Arabia, including all participants who participated during BSSCs. A pretested questionnaire was used to collect data on age, sex, training level, institution, overall experience, course overload, course duration, best feature of the course, and whether participants would recommend the course to their colleagues. Whenever possible, self-reported data were compared with registration records, and any conflict was resolved by discussion. Results BSSC was found in a total of 489 participants. More than 58% of the participants were men. Majority of students came from out of KAUH (61%) and were medical interns (63%). Overall experience of the course was very beneficial (57%). The course workload and duration were rated as about right by 82% and 75% of participants, respectively. Majority of participants found that the “hands-on practice” as the best segment of the course (76%). Conclusion The study showed a positive perception of this surgical education modality among participants. This study will help guide the future research on advanced simulation-based surgical training in the region.

Surgical training of minimally invasive mitral valve repair on a patient-specific simulator improves surgical skills.

Minimally invasive mitral valve repair (MVR) is considered one of the most challenging operations in cardiac surgery and requires much practice and experience. Simulation-based surgical training might be a method to support the learning process and help to flatten the steep learning curve of novices. The purpose of this study was to show the possible effects on learning of surgical training using a high-fidelity simulator with patient-specific mitral valve replicas. Twenty-five participants were recruited to perform MVR on anatomically realistic valve models during different training sessions. After every session their performance was evaluated by a surgical expert regarding accuracy and duration for each step. A second blinded rater similarly assessed the performance after the study. Through repeated documentation of those parameters, their progress in learning was analysed, and gains in proficiency were evaluated. Participants showed significant performance enhancements in terms of both accuracy and time. Their surgical skills showed sizeable improvements after only 1 session. For example, the time to implant neo-chordae decreased by 24.64% (354 s-264 s, P < 0.001) and the time for annuloplasty by 4.01% (54 s-50 s, P = 0.165), whereas the number of irregular stitches for annuloplasty decreased from 52% to 24%.The significance of simulation-based surgical training as a tool for acquiring and training surgical skills was reviewed positively. The results of this study indicate that simulation-based surgical training is a valuable and effective method for learning reconstructive techniques of minimally invasive MVR and overall general dexterity.The novel learning and training options should be implemented in the surgical traineeship for systematic teaching of various surgical skills.

Exploring the Role of Simulation Training in Improving Surgical Skills Among Residents: A Narrative Review.

The role of simulation in medical education is crucial to the development of surgeons' skills. Surgical simulation can be used to improve surgical skills in a secure and risk-free environment. Animal models, simulated patients, virtual reality, and mannequins are some types of surgical simulation. As a result, feedback encourages students to reflect on their strengths and weaknesses, enabling them to focus on improvement. Healthcare simulation is a strong educational instrument, and the main goal of this is to give the students an opportunity to do a practical application of what they have learned through theory. Before taking it to the patients, they will already have certain tools they have previously acquired during the practice. This makes it easier for students to identify the knowledge gaps that they must fill to improve patient outcomes. Moreover, simulation brings a wonderful opportunity for students to acquire skills, gain confidence, and experience success before working with real patients, especially when their clinical exposure is limited. The use of simulation to teach technical skills to surgical trainees has become more prevalent. The cost of setting up a simulation lab ranges from $100,000 to $300,000. There are several ways to evaluate the effectiveness of simulation-based surgical training. Repetitive surgical simulation training can improve speed and fluidity in general surgical skills in comparison to conventional training. Few previous studies compared learners who received structured simulation training to a group of trainees who did not receive any simulation training in single-center randomized control research. Significantly faster and less time-consuming skill proficiency was noticeable in simulated trainees. Despite being anxious in the operating room for the first time, simulated trainees completed the surgery on time, demonstrating the effectiveness of surgical simulation training. Traditional surgical training involves senior-surgeon supervision in the operating room. In simulation-based training, the trainees have full control over clinical scenarios and settings; however, guidance and assessment are also crucial. Simulators allow users to practice tasks under conditions resembling real-life scenarios. Simulators can be compared with traditional surgical training methods for different reasons. For example, intraoperative bleeding may occasionally show up not only visibly on the screen but also by shaking the trocars erratically. Without haptics, training on virtual simulators can cause one's pulling and pushing forces, which are frequently greater than what the tissue needs, to be distorted. A good method of simulation training is using virtual reality simulators with haptics and simulated patients. The availability of these facilities is limited, though, and a typical session might include an exercise involving stacking sugar cubes and box trainers. The degree of expertise or competency is one area that needs clarification as medical education transitions to a competency-based paradigm. The article aims to provide an overview of simulation, methods of simulation training, and the key role and importance of surgical simulation in improving skills in surgical residents.

Technical, Non-Technical, or Both? A Scoping Review of Skills in Simulation-Based Surgical Training

Technical and non-technical skills are traditionally investigated separately in simulation-based surgical training (SBST). Recent literature has indicated an interrelation of these skills, but a clear relationship is yet to be established. This scoping review aimed to identify published literature on the use of both technical and non-technical learning objectives in SBST and investigate how the entities are related. Additionally, this scoping study reviewed the literature with the aim of mapping how publications on technical and non-technical skills within SBST have changed over time. We conducted a scoping review using the 5 step framework by Arksey and O'Malley and reported our results according to the PRISMA guidelines for scoping reviews. Four databases, PubMed, Web of Science, Embase and Cochrane Library, were systematically searched for empirical studies on SBST. Studies within surgical training addressing both technical and non-technical learning objectives and presenting primary data were included for further analysis. Our scoping review identified 3144 articles on SBST published between 1981 and 2021. During our analysis, an emphasis on technical skills training in published literature was identified. However, recent years have seen an immense increase of publications within either technical or non-technical skills. A similar trend is seen in publications addressing both technical and non-technical. In total, 106 publications addressed both technical and non-technical learning objectives and were included for further analysis. Only 45 of the included articles addressed the relationship between technical and non-technical skills. These articles mainly focused on the effect of non-technical skills on technical skills. Though literature on the relationship between technical and non-technical skills remains scarce, the included studies on technical skills and non-technical skills such as mental training suggest such a relationship exists. This implies that the separation of the skill sets is not necessarily beneficial for the outcome of SBST. A shift towards seeing technical and non-technical skills as intertwined may enhance learning outcomes from SBST.

Ticket to perform: an explorative study of trainees’ engagement in and transfer of surgical training

BackgroundResearch suggests that simulation-based surgical skills training translates into improved operating room performance. Previous studies have predominantly focused on training methods and design and subsequent assessable performances and outcomes in the operating room, which only covers some aspects of training engagement and transfer of training. The purpose of this qualitative study was to contribute to the existing body of literature by exploring characteristics of first-year trainees’ engagement in and perceptions of transfer of surgical skills training.MethodsWe conducted an explorative study based on individual interviews with first-year trainees in General Surgery, Urology, and Gynaecology and Obstetrics who participated in a laparoscopic skills training program. Informants were interviewed during and two months after the training program. A thematic cross-case analysis was conducted using systematic text condensation.ResultsWe interviewed 12 informants, which produced 24 transcripts for analysis. We identified four main themes: (1) sportification of training, (2) modes of orientation, (3) transferrable skills, and (4) transfer opportunities. Informants described their surgical training using sports analogies of competition, timing, and step-by-step approaches. Visual orientations, kinaesthetic experiences, and elicited dialogues characterised training processes and engagement. These characteristics were identified in both the simulated and the clinical environment. Experiences of specific skills transfer included ambidexterity, coordination, instrument handling, and visuospatial ability. General transfer experiences were salient in informants’ altered training approaches. Informants considered the simulation-based training an entry ticket to perform in the operating room and mentioned supervisor-trainee relationships and opportunities in the workplace as critical conditions of transfer.ConclusionsOur findings elucidate characteristics of surgical training engagement that can be interpreted as self-regulated learning processes that transcend surgical training environments. Despite appreciating the immediate skills improvements resulting from training, trainees’ narratives reflected a struggle to transfer their training to the clinical setting. Tensions existed between perceptions of transferable skills and experiences of transfer within the clinical work environments. These results resonate with research emphasising the importance of the work environment in the transfer process. Our findings provide insights that may inform the development of training programs that support self-regulated learning and transfer of training from the simulated to the clinical environment.

Simulating Ovariohysterectomy: What Type of Practice Promotes Short- and Long-Term Skills Retention?

Simulation-based surgical training allows students to learn skills through deliberate practice without the patient risk and stress of operating on a live animal. This study sought to determine the ideal distribution of training sessions to improve short- and long-term retention of the skills necessary to perform a simulated ovariohysterectomy (OVH). Fourth-semester students (n = 102) were enrolled. Students in the weekly instruction group (n = 57) completed 10 hours of training on the OVH simulator, with sessions held at approximately weekly intervals. Students in the monthly instruction group (n = 45) completed the same training with approximately monthly sessions. All students were assessed 1 week (short-term retention test) and 5 months following the last training session (long-term retention test). Students in the weekly instruction group scored higher on their short-term assessment than students in the monthly instruction group (p < .001). However, students' scores in the weekly instruction group underwent a significant decrease between their short- and long-term assessments (p < .001), while the monthly group did not experience a decrease in scores (p < .001). There was no difference in long-term assessment scores between weekly and monthly instruction groups. These findings suggest that if educators are seeking maximal performance at a single time point, scheduling instructional sessions on a weekly basis prior to that time would be superior to monthly sessions, but if educators are concerned with long-term retention of skills, scheduling sessions either on a weekly or monthly basis would accomplish that purpose.

Opportunity to Perform – Should Simulation-Based Surgical Training be Provided on Demand or on Supply?

Introduction The aim of the study was to assess the surgical case volume of residents before and after simulation-based training in hip fracture surgery provided on demand versus knee and shoulder arthroscopy provided on supply. Materials and Methods A retrospective analysis of surgical case volume in hip fracture surgery and arthroscopic shoulder and knee procedures 90 days before and after simulation-based training of either procedure. Sixty-nine orthopedic residents voluntarily participating in either simulation-based training. Hip fracture surgery simulation was provided on supply, ie, whenever 1–2 residents applied for the course, while the arthroscopic simulation course was supplied twice yearly. Results Thirty-four residents participated in hip fracture simulation on demand and 35 residents participated in arthroscopic simulation on supply. The surgical case volume of hip fracture osteosynthesis increased from median 2.5 (range: 0–21) to median 11.5 (1–17) from 90 days before to the 90 days after the simulation-based training on demand. The median difference was 6.5 procedures (p &lt; 0.0003). On the contrary, the surgical case volume in shoulder and knee arthroscopy was low both before and after the simulation on supply, ie, median 2 (0–22) before and median 1 (0–31) after. The median difference was 0 (p = 0.21). Conclusions Simulation on demand was associated with increased opportunities to perform in the clinical environment after the simulation-based training compared with simulation on supply. Simulation-based training should be aligned with the clinical rotation of the residents. Simulation on demand instead of supply on fixed dates may overcome this organizational issue of aligning training with the opportunity to perform.

25 - Simulation in Urological Training and Education (SIMULATE): A randomised controlled trial to determine the effect of simulation-based surgical training

25 - Simulation in Urological Training and Education (SIMULATE): A randomised controlled trial to determine the effect of simulation-based surgical training

Open Simulation Environment for Learning and Practice of Robot-Assisted Surgical Suturing

Automation has the potential to improve the standard of care but is difficult to realize due to perceptual challenges, especially in soft-tissue surgery. Machine learning can provide solutions, but typically requires large amounts of training data, which is time-consuming to collect. Even with shared platforms, hardware differences can prevent effective sharing of data between institutions. This letter proposes a standardized simulation platform for training and testing algorithms to control surgical robotic systems, which is built upon an open-source simulator, the Asynchronous Multi-Body Framework (AMBF), to enable quick prototyping of different scenes. An illustrative example of a suturing task on a phantom is presented and has formed the basis of a challenge, released to the community. The top-level contribution is the open-source release of a dynamic simulation environment that enables realistic suturing on a phantom, but supporting contributions include its extendable architectural design and a series of algorithmic optimizations to achieve real-time control and collision detection, realistic behavior of the needle and suture, and generation of multi-modal ground-truth data, including labeled depth data. These capabilities enable simulation-based surgical training and support research in machine learning for surgical scene perception and autonomous action.

P0961 - Simulation in urological training and Education (SIMULATE): A randomised controlled clinical and educational trial to determine the effect of simulation-based surgical training

P0961 - Simulation in urological training and Education (SIMULATE): A randomised controlled clinical and educational trial to determine the effect of simulation-based surgical training

Remote training in laparoscopy: a randomized trial comparing home-based self-regulated training to centralized instructor-regulated training.

BackgroundSimulation-based surgical training (SBST) is key to securing future surgical expertise. Proficiency-based training (PBT) in laparoscopy has shown promising results on skills transfer. However, time constraints and limited possibilities for distributed training constitute barriers to effective PBT. Home-based training may provide a solution to these barriers and may be a feasible alternative to centralized training in times of assembly constraints.MethodsWe randomly assigned first-year trainees in abdominal surgery, gynecology, and urology to either centralized instructor-regulated training (CIRT) or home-based self-regulated training (HSRT) in laparoscopy. All participants trained on portable box trainers providing feedback on metrics and possibility for video reviewing. Training in both groups was structured as PBT with graded proficiency exercises adopted from the Fundamentals of Laparoscopic Surgery (FLS). The HSRT group trained at home guided by online learning materials, while the CIRT group attended two training sessions in the simulation center with feedback from experienced instructors. Performance tests consisted of hand–eye and bimanual coordination, suture and knot-tying, and FLS exercises. We analyzed passing rates, training time and distribution, and test performances.ResultsPassing rates were 87% and 96% in the CIRT and HSRT group, respectively. HSRT facilitated distributed training and resulted in greater variation in training times. Task times for hand–eye and bimanual coordination were significantly reduced between pretest and posttest in both groups. Trainees maintained their posttest performances at the 6-month retention test. Our analyses revealed no significant inter-group differences in performances at pretest, posttest, or retention test. Performance improvements in the two groups followed similar patterns.ConclusionCIRT and HSRT in laparoscopy result in comparable performance improvements. HSRT in laparoscopy is a feasible and effective alternative to CIRT when offered inside a supportive instructional design. Further research is needed to clarify trainees’ preferences and explore facilitators and barriers to HSRT.

The utilisation of 3D printing in paediatric neurosurgery.

3D printing technology has evolved over the years and there is a growing interest in its application in paediatric neurosurgery. Modern 3D printers have enabled the development of patient-specific 3D models that provide a realistic representation of complex anatomies and will aid in planning complex procedures. Paediatric neurosurgical operations are challenging and hands-on training is restricted. Surgical simulation training with biomodel has provided a new paradigm for trainees to master their surgical skills before encountering similar scenarios in real-life environment. This paper reviews the aspects of 3D printing for preoperative planning and simulation-based surgical training in paediatric neurosurgery.

Simulation-based surgical education for glaucoma versus conventional training alone: the GLAucoma Simulated Surgery (GLASS) trial. A multicentre, multicountry, randomised controlled, investigator-masked educational intervention efficacy trial in Kenya, South Africa, Tanzania, Uganda and Zimbabwe

Background/AimGlaucoma accounts for 8% of global blindness and surgery remains an important treatment. We aimed to determine the impact of adding simulation-based surgical education for glaucoma.MethodsWe designed a randomised controlled,...

Deliberate Practice in Simulation-Based Surgical Skills Training: A Scoping Review

In recent years there has been a shift from traditional Halstedian methods toward more simulation-based medical education (SBME) for developing surgical skills. Questions remain about the role and value of SBME, although feedback and engagement in repetitive practice have been associated with positive learning outcomes. Regardless of approach, the principles of deliberate practice align with both the Halstedian traditions and ways of implementing SBME. Whilst deliberate practice is well described in the wider literature, the extent to which it is an effective instructional approach in surgical training remains unknown. To explore the effectiveness of deliberate practice as an instructional design for developing surgical skills through SBME interventions, as assessed by improvements in trainee performance and/or patient outcomes. A combined search was conducted in PUBMED, CINAHL, EMBASE, MEDLINE, PSYCHINFO, and Google Scholar. Three hundred one articles were screened and 17 met the inclusion criteria for analysis. There was heterogeneity of study methods with 6 randomized control trials, 7 pretest/post-test design, 2 nonrandomized comparisons and 2 observational studies. All articles demonstrated positive learner outcomes following SBME with deliberate practice, although there was no direct comparison to another instructional method. Two studies demonstrated skill transfer to the clinical environment and 1 demonstrated improved patient outcomes. Deliberate practice informed SBME interventions appeared effective for developing surgical skills among trainee surgeons, however the reliability of these conclusions was limited by the modest quality of the research studies and the design elements of deliberate practice were inconsistently applied. There was little evidence that deliberate practice led to skills retention beyond 30 days, although participant numbers were low and the quality of studies was modest.

Simulation-based surgical training systems in laparoscopic surgery: a current review

Simulation-based training has been widely used in medical education. More specifically, various systems for minimally invasive surgery training have been proposed in the past two decades. The aim of this article is to review and summarize the existing simulation-based training systems for laparoscopic surgery in terms of their technical realizations. Forty-three training systems were found and analyzed. These training systems generally consist of training tasks, a visualization interface, and an instrument interface. Three different approaches—physical, virtual, and augmented reality—to implement visualization interfaces are discussed first. Then, haptic feedback, performance evaluation, and guidance methods are summarized. Portable devices to enable at-home training and instrument tracking technologies to support visualization, evaluation, and guidance are also presented. Based on survey of the relevant literature, we propose several recommendations to design the next-generation training systems in laparoscopic surgery. Novel guidance and assessment schemes with augmented reality visualization are recommended to design an intelligent surgical training simulator. This intelligent simulator enhances the training procedure and ultimately improves the patient safety.

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

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

Letter on "3D printed patient individualized models versus cadaveric models in an undergraduate Oral and Maxillofacial Surgery Curriculum: Comparison of student's perceptions".

In the recent publication "3D printed patient individualized models versus cadaveric models in an undergraduate Oral and Maxillofacial Surgery Curriculum"1 a 3D-printed, individualized patient model for undergraduate training of operating skills in Oral and Maxillofacial surgery is described. The authors should be acknowledged for addressing the need for surgical simulation-based training in Oral and Maxillofacial surgery. Nevertheless, from a scientific perspective, we have several concerns about the methods applied for evaluation of the model and the resulting conclusions.