Anterolateral Thigh Flap in a Chicken Model: A Novel Perforator Training Model

Microsurgical training with chicken wings: Could it be an option to increase experience for vascularized bone flaps?

OBJECTIVE

To our knowledge, a vascularized bone flap training model has not been described in the literature. In this study, we hypothesized that chicken wing radius bone can be used as a cheap, realistic and easily accessible vascularized pedicled bone flap training model.

METHODS

A final total of 10 specimens were included in the study. All procedures were planned and conducted by the same surgeon. In all 10 specimens, the length of the radius bone and the length of the vascularized bone flap were measured with a standard ruler. The external diameters of the ulnar artery and the radial artery forming the flap pedicle were measured.

RESULTS

Flap harvesting time (40.4 ± 7.98') was measured as the time between proper positioning of the chicken wing and the complete separation of the flap from the wing. Mean radius bone length was 6.09 ± 0.72 cm, bone flap length (3.92 ± 0.36 cm) was measured as the distance between two osteotomies in the maximum length of bone (proximal and distal) according to the preparation of the radial artery pedicle. Mean radial artery pedicle external diameter was 0.51 ± 0.05 mm, while mean ulnar artery pedicle external diameter was 0.6 ± 0.04 mm. On average, 4.3 ± 0.82 perforators of the radial artery (to the other regions of the flap) were ligated.

CONCLUSION

We think that this model can be a pioneer in defining the bone flap model in living animals in future studies. Since this inanimate animal model is a cost-effective and easily accessible technique, it offers the opportunity to be applied easily and repeatedly, even in the comfort of surgeons' homes.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

3D-printed cranial models simulating operative field depth for microvascular training in neurosurgery

BACKGROUND

The skills required for neurosurgical operations using microsurgical techniques in a deep operating field are difficult to master in the operating room without risk to patients. Although there are many microsurgical training models, most do not use a skull model to simulate a deep field. To solve this problem, 3D models were created to provide increased training in the laboratory before the operating room, improving patient safety.

METHODS

A patient's head was scanned using computed tomography. The data were reconstructed and converted into a standard 3D printing file. The skull was printed with several openings to simulate common surgical approaches. These models were then used to create a deep operating field while practicing on a chicken thigh (femoral artery anastomosis) and on a rat (abdominal aortic anastomosis).

RESULTS

The advantages of practicing with the 3D printed models were clearly demonstrated by our trainees, including appropriate hand position on the skull, becoming comfortable with the depth of the anastomosis, and simulating proper skull angle and rigid fixation. One limitation is the absence of intracranial structures, which is being explored in future work.

CONCLUSION

This neurosurgical model can improve microsurgery training by recapitulating the depth of a real operating field. Improved training can lead to increased accuracy and efficiency of surgical procedures, thereby minimizing the risk to patients.

Augmentation of Chicken Thigh Model with Fluorescence Imaging Allows for Real-Time, High Fidelity Assessment in Supermicrosurgery Training

BACKGROUND

 The skills required for supermicrosurgery are hard-earned and difficult to master. The University of Wisconsin "blue-blood" chicken thigh model incorporates perfusion of the thigh vessels with a blue liquid solution, allowing users to visualize flow across their anastomoses. This model has proven to be an excellent source of small vessels (down to 0.3 mm) but assessing the quality of anastomoses at this spatial scale has proven difficult. We evaluated whether fluorescent imaging with indocyanine green (ICG) in this realistic training model would enhance the assessment of supermicrosurgical anastomoses, and therefore improve real-time feedback to trainees.

METHODS

 Anastomoses of vessels ranging from 0.35 to 0.55mm in diameter were performed followed by the capture of white light with and without fluorescence imaging overlay during infusion of "blue-blood" and ICG. Videos were randomized and shown to seven fellowship-trained microsurgeons at the University of Wisconsin-Madison who rated each anastomosis as "patent," "not patent," or "unsure." Surgeon accuracy, uncertainty, and inter-rater agreement were measured for each imaging modality.

RESULTS

 Use of fluorescence significantly increased surgeon accuracy to 91% compared with 47% with white light alone (p = 0.015), decreased surgeon uncertainty to 4% compared with 41% with white light alone (p = 0.011), and improved inter-rater agreement from 53.1% with white light alone to 91.8% (p = 0.016).

CONCLUSION

 Augmentation of the University of Wisconsin "blue-blood" chicken thigh model with ICG fluorescence improves accuracy, decreases uncertainty, and improves inter-rater agreement when assessing supermicrosurgical anastomoses in a training setting. This improved, real-time feedback enhances this model's value as a supermicrosurgical training tool.

Ex Vivo Ovine Model for Surgical and Microsurgical Training on Parotidectomy and Facial Nerve Reanimation: Proposal of Structured Training Program

INTRODUCTION

 Facial nerve palsy has a great physical and psychological impact on patients, so the avoidance of facial nerve damage during surgery and its reanimation are important for Otolaryngologists and head and neck surgeons. The acquisition of anatomical knowledge and surgical training regarding the parotid surgery and facial nerve is mandatory, but not easy to achieve. Surgical simulation is a reliable alternative to the on-the-job learning. In the study, we tested an ex vivo animal model to obtain the basic and advanced skills of parotid gland surgery and facial nerve reconstruction/reanimation.

MATERIALS AND METHODS

 A prospective cohort study has been conducted on ovine head and neck specimen. A junior resident, a senior resident, and an expert surgeon were involved in a step-by-step preplanned dissection, divided in macroscopic and microscopic. Each procedure was recorded and evaluated by an expert surgeon following an adapted rating scale.

RESULTS

 A statistically significant improvement in terms of execution times and quality of the work was show in most of the surgical steps and for many quality items by the junior and senior residents, while the expert surgeon, as expected, did not show any improvement.

DISCUSSION

 Our ex vivo ovine model provided the trainee with close-to-real tissues in term of elastic resistance and consistency, to learn the skills requested in a head and neck surgery, on a reproducible environment. It is mandatory to have a feedback, which focuses on the quality of the work through valid and reliable assessment of technical skills. The judgment parameters should be reproducible and focused on the specific surgical procedure. Some limitations to this study are present, such as anatomical differences between ovine and human and the limited number of study participants.

CONCLUSION

 This proposal of training program on the ex vivo ovine model for the acquisition of skills needed in head and neck surgery proved to be feasible, effective, repeatable, and cheap.

The Blue-Blood Porcine Chest Wall: A Novel Microsurgery Training Simulator for Internal Mammary Vessel Dissection and Anastomosis

BACKGROUND

 Preparation of the internal mammary artery (IMA) is a critical step in autologous breast reconstruction. Intraoperatively, there is limited opportunity for residents to practice this skill. Porcine models provide highly realistic simulation for vascular surgery; however, use of live laboratory pigs is expensive, inconvenient, and offers limited opportunity for repetitive training. We aimed to develop an inexpensive and effective training model for IMA preparation. This article describes creation of a novel microsurgical model using cadaveric chest walls of Wisconsin Miniature Swine embedded in a modified mannequin thorax and augmented with a blue-blood perfusion system.

METHODS

 Anatomic comparison: five porcine chest walls were dissected, and various anatomic measurements were made for anatomic comparison to existing human data in the literature. Model assembly: the chest wall is prepared by cannulating the proximal and distal ends of the internal mammary vessels with angiocatheters, which are then connected to the blue-blood perfusion system. The model is assembled in four layers including: (1) a mannequin thorax with a window removed to expose the first to fourth intercostal spaces, bilaterally, (2) a layer of foam simulating fat, (3) the perfused pig chest wall, and (4) a second mannequin shell placed posteriorly for support.

RESULTS

 The porcine chest walls are similar to humans with regards to vessel size and location. This model can be assembled quickly, with a one-time approximate cost of $55.00, and allows for six training sessions per specimen. The model allows residents to practice the key steps of IMA preparation including dissection, elevation of perichondria, and vascular anastomosis while working at a depth that closely simulates the human thorax. Continuous blue-blood perfusion provides immediate feedback on anastomosis quality.

CONCLUSION

 Overall, this novel model can provide inexpensive and realistic simulation of internal mammary vessel preparation and anastomosis.

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.