Experience of Raising Flaps Using Cadavers Embalmed by Saturated Salt Solution Method

Abstract

Sir: In plastic and reconstructive surgery, raising the flap is an important skill1; but sometimes it is difficult for young plastic surgeons to detect and isolate the vessels. However, only a few studies have focused on flap training using cadavers. In these studies, researchers used formalin fixation techniques, which produced tissues with rigidities too high to provide a realistic simulation of flap training.2 Therefore, preservation methods such as fresh cadaver3,4 and Thiel method2 have been favored. Fresh cadaveric tissue is a superior model of simulation because of its approximation of live tissue,4 but it has many disadvantages such as high cost, limited use, and risk of infection.1,2 Thiel-embalmed cadavers have life-like color and flexibility.2 However, Thiel method is quite complicated and requires the use of several problematic and expensive substances during its preservation process. In addition, Thiel-embalmed cadavers have their drawbacks: muscular disintegration and limited time for dissection.5 Recently, Hayashi et al5 reported that the cadavers embalmed by the saturated salt solution (SSS) method, which consisted of saturated sodium chloride, low-dose formaldehyde, phenol, glycerin, isopropyl alcohol, and water, were not less suitable than Thiel-embalmed cadavers in several skills training courses in acute care surgery. Therefore, the authors tried raising several flaps in the SSS-cadavers for future use in flap training. Four SSS-embalmed cadavers and 1 Thiel-embalmed cadaver were used for this study, and the procedures were performed in an anatomical training room at Tokyo Medical University. All procedures were performed by Takayuki Shirai (a plastic surgeon with 9 years of experience). The cadavers were used 1–6 months after they had been preserved, and each cadaver was used several times. The types of flaps made included the following: oblique triangular flap, reverse digital artery island flap (Fig. 1), latissimus dorsi musculocutaneous flap, superficial temporal fascia flap, nasolabial flap, and anterolateral thigh flap (Fig. 2).Fig. 1: Reverse digital artery island flap.Fig. 2: Anterolateral thigh flap.Because SSS-embalmed cadavers tend to have realistic skin and soft tissue, anatomical structures were easy to identify and the operations could be performed very much as in live patients (Figs. 1, 2). These features of SSS-embalmed cadavers were almost identical to those in Thiel-embalmed cadavers. In addition, the vessels of the SSS-embalmed cadavers were more expanded because of ample fluid, making our detection and isolation of vessels and raising of flaps easier in them than in the Thiel-embalmed cadaver. CONCLUSIONS SSS-embalmed cadavers are sufficiently useful in flap training. The SSS method is simple with a low infection risk and relatively low cost.5 Furthermore, SSS-embalmed cadavers have availability for multiple uses and their vessels can be easily detected. Our trial suggests that the characteristics of SSS-embalmed cadaver may be ideal for trainees of plastic surgery. ACKNOWLEDGMENTS We thank Dr. Ning Qu, Dr. Naoyuki Hatayama, and Dr. Shuichi Hirai for reviewing and providing useful comments to us preparing in our manuscript. We also thank Mr. Shinichi Kawata and Mr. Koichi Koyama for their excellent technical assistance, and Ms. Yuki Ogawa, Ms. Miyuki Kuramasu, and Ms. Keiko Kuwana for their excellent secretarial assistance. DISCLOSURE The authors have no financial interest to declare in relation to the content of this article. This study was supported by JSPS KAKENHI Grant Number 26463257. The Article Processing Charge was paid for by the authors. Takayuki Shirai, MD Department of Plastic Surgery Asama General Hospital Saku-shi, Nagano, Japan Department of Anatomy Tokyo Medical University Shinjuku-ku, Tokyo, Japan Shogo Hayashi, MD, PhD Masahiro Itoh, MD, PhD Department of Anatomy Tokyo Medical University Shinjuku-ku, Tokyo, Japan