LAUSR

Dear Editor: Recent developments in optical microscopy and microsurgery technologies have led to reports of the effectiveness of super-microsurgery in the creation of anastomoses in microvessels and lymphatic vessels measuring 0.5 mm in diameter and smaller in cases of refractory diseases (Giacalone et al., 2019). Digital imaging technology has also led to the use of 8K and other types of ultra-high-definition cameras in medical settings, and their use has begun in a variety of fields in which endoscopic surgery is performed with the surgeon viewing images displayed on a television screen (Ohigashi et al., 2019). Thus, this technology is expected to provide images that are on par with those produced by microscopes. Nevertheless, super-enlarged images produced by an 8K camera alone have a narrow depth of field and produce laterally stereoscopic images (Yamashita et al., 2018). As a result, the electronic input data must be reduced by half in order to obtain a stereoscopic view. The authors developed a next-generation technology that makes optical improvements to the electronic image input and thereby solves this problem. It is capable of (a) Magnification of ×300 and (b) a stereoscopic view obtained through a single lens and increased depth of field. Regarding the former, although currently conventional surgical microscopes are capable of magnification between ×20 and ×30, the use of a large (70 in.) 8K monitor and digital zoom function allows theoretical magnifications of up to ×300. Regarding the latter, optimization of the angle of view and angle of illumination allows the “drop-shadow effect,” which produces a stereoscopic view. Additionally, using the zoom function at the point that provides the optimal angle of view allows increased depth of field (Figure 1A). We verified the effectiveness of this technique by using our newly developed device on an abdominal lymph vessel anastomosis model of a rat (Kellersmann, Grant, & Zhong, 1999; Yamashita et al., 2018; modified method utilized by Kellersmann R, et al). in vivo use was approved by the Keio University School of Medicine Animal Ethics Committee (permit no. 18011), and the study was conducted using 200–250 g male LEW rats. Under the influence of an inhalation anesthetic, a ventral incision was made, and tweezers were used to carefully expose the abdominal lymph vessels at the inferior extremity of the left kidney. The lens was placed at a distance of 30 cm from the surgical field. The lymph vessels in this region are approximately 0.2–0.3 mm in diameter, and the capillaries that supply the lymph vessels can be clearly discerned (Figure 1B). Anastomosis was performed using a 3–4 needle with 12-0 sutures used cross-sectional in this region. After the completion of anastomosis, patency was checked by inserting an 11-0 nylon suture from this region and subsequently re-opening the abdomen and injecting methylene blue. In all cases, anastomosis could be performed swiftly and safely. The degree of magnification of the surgical field that can be obtained using this system theoretically exceeds the capabilities of conventional microscopes. The clinical significance must be validated by experts who utilize it in supermicrosurgery.