Summary: Simulation in microsurgery is an important pillar of training and maintenance of surgical skills. Between learning microsurgical skills and mastering them in clinical practice, the usefulness of low-fidelity simulators for improving microsurgery skills has been well documented. Nowadays the in vivo models represent the gold standard of microsurgical training; however, their use implies difficulties and limitations. We developed a portable, low-cost, and modern device to help trainees to practice at their convenience to maintain their microsurgical suturing skills. By using CAD and 3D printer designs, we developed a “microsurgery trainer” that contains a middle section with eight projections with holes, arranged as a circle. The idea is to pass the microsuture—preferably 7/0 or 8/0 sutures—in a clockwise manner—with the needle passing from “out to in” and “in to out” through each hole. This allows the trainee to use his/her wrist to be flexible and achieve better control over the micro needle. Studies evaluating the potential of such a device in shortening the learning curve are needed and will be crucial to define whether the “microsurgery arena” will help trainees to obtain better outcomes in microsurgical practice.

Introduction: The excision of lesions that are not oriented along the skin tension lines may cause the surgeon to design extremely broad elliptical preoperative markings, with the intent to follow the tension lines as recommended for the best postoperative course and the best quality scars. The aim of this study is to describe and clinically apply a new surgical technique called the parallelogram excision technique, in which the traditional ellipse with a major axis parallel to the tension lines is converted into a parallelogram whose lesser sides are coincident with the local skin tension lines. This technique was specifically conceived for lesions whose major axis is non-coincident with skin tension lines, and the primary advantage is that it reduces the amount of healthy tissue excised. Methods: Preliminarily to this clinical study, a comparative geometrical analysis was conducted between various excision shapes and angles using Geometry Pad version 2.7.10 (Bytes Arithmetic LLC) and verifying the data obtained through AutoCAD 2D 2016 (Autodesk, San Rafael, CA, USA), with the purpose of optimizing the technique from a geometrical point of view. A comparison was performed between the theoretical traditional elliptical excision and the hypothetical parallelogram excision. A pilot proof of concept clinical study was performed to verify the validity of the excisional design proposed. The patients considered for parallelogram excision suffered from skin lesions with a diameter no greater than 4 cm and oriented 45° to 60° with respect to tension lines. In order to limit variability, patients’ ages were between 40 and 80, and the selected areas were limbs, sternum and dorsum. Scar quality was assessed with the validated POSAS method at 6 months post-operation. Results: The geometrical analysis of the parallelogram’s design showed that it allows a diminution of the excised healthy skin compared to the traditional ellipse. The clinical series included 16 patients, with a mean age of 63.5. Of these, nine patients were men and seven were women. Diagnoses included basal cell carcinoma in seven cases, dysplastic naevus in five patients, Bowen’s disease in three individuals, and one case where a wider excision of a malignant melanoma was performed. Six-month follow up results showed: (1) an uneventful postoperative course; (2) good scar healing with an observer’s POSAS median score of 16 and a patient’s POSAS median score of 19; and (3) complete excision of lesions. Conclusions: When indicated, the parallelogram excision technique appears to be a good option for the excision and primary closure of skin lesions that are not parallel to skin tension lines, since it allows a reproducible and surgeon-friendly method of preoperative marking and implies a favorable use of the local tension, which determines good quality scars. The amount of healthy tissue removed is smaller compared to traditional elliptic excisions.

The medial femur condyle (MFC) cortico‐periosteal flap is a popular flap for bone reconstruction. The use of a chimeric version of this flap with a skin island has been described, but anatomical arterial variation can occur that prevent its harvest. Furthermore, the donor area of the skin paddle has been debated as poor because of the scarring in a visible area and because of the difficulty in obtaining pliable thin skin. We present a fabricated chimeric MFC cortico‐periosteal flap joined with a superficial inferior epigastric perforator (SCIP) flap to reconstruct and augment a sclerotic and insufficient small clavicula with the skin paddle acting as a monitor and as a substitute for the overlying skin. A 52‐year‐old female patient had a history of multiple refractures of the right hypoplastic clavicle with a diameter of 7 mm, resulting in a sclerotic bone with a fibrotic scar. The reconstruction was done in one surgical session using a cortico‐periosteal flap from the left medial condyle and a thin SCIP flap from the left groin. The area of the clavicle to be reconstructed was 3 cm, and the direct overlying skin (approximately 6 × 3 cm) was severely scarred and painful. The MFC flap was 5 × 4 cm, while the SCIP flap was 7 × 3.5 cm. The SCIP flap artery was anastomosed on the table end‐to‐side to the descending genicular (DG) artery of the MFC, and the vein was anastomosed end‐to‐end to a comitans vein of the DG artery. The flap fully survived after an initial congestion. At 12 months, we observed a satisfactory reconstruction of the clavicle with an enhanced diameter of 12 mm. The patient recovered full function of the shoulder with no pain. Using a fabricated chimeric flap composed of a medial femoral condyle and a superficial circumflex artery perforator flap may be an additional option for tailored reconstruction of complex osteo‐cutaneous defect of clavicle.

Microfluidic principles have been widely applied for more than 30 years to solve biological and micro-electromechanical problems. Despite the numerous advantages, microfluidic devices are difficult to manage as their handling comes with several technical challenges. We developed a new portable tool, the microfluidic trainer (MT), that assesses the operator handling skills and that may be used for maintaining or improving the ability to inject fluid in the inlet of microfluidic devices for in vitro cell culture applications. After several tests, we optimized the MT tester cell to reproduce the real technical challenges of a microfluidic device. In addition to an exercise path, we included an overfilling indicator and a correct infilling indicator at the inlet (control path). We manufactured the MT by engraving a 3 mm-high sheet of methacrylate with 60W CO₂ laser plotter to create multiple capillary paths. We validated the device by enrolling 21 volunteers (median age 33) to fill both the MT and a commercial microfluidic device. The success rate obtained with MT significantly correlated with those of a commercial microfluidic culture plate, and its 30 min-continuous use for three times significantly improved the performance. Overall, our data demonstrate that MT is a valid assessment tool of individual performances in using microfluidic devices and may represent a low-cost solution to training, improve or warm up microfluidic handling skills.