A Case-control Analysis of the Knight’s Move Technique in a Chicken Wing Microsurgery Model: Video Article

摘要

INTRODUCTION International consensus has defined supermicrosurgery as a microneurovascular technique for vessels and single nerve fascicles ranging from 0.3 to 0.8 mm in diameter,1 but Yamamoto et al have further lowered this threshold to 0.5 mm and smaller.2 Current supermicrosurgical anastomostic techniques rely on the precision and dexterity of human hands with the specific use of customized supermicrosurgery instruments3 or extremely small caliber sutures as threader loops or intravascular stents to facilitate the anastomoses,2,4–7 prompting the introduction of robotic devices to overcome this limitation.8 Adjunctive techniques described include temporary lymphatic expansion for lymphotomies in preparation for side-to-side (S-S) and end-to-side (E-S) anastomoses,9 the parachute technique,10 intraluminal fillers,11 and a 30-µm needle usage.12 However, in all these instances, specialized supermicrosurgery instruments were used. In this study, we ask the question as to whether we need to. An animal model study showed that there was a 90% survival rate at 1 week in a rat superficial inferior epigastric flap model (vessel dimensions of up to 0.3–0.4 mm), using conventional microsurgery instruments albeit with 11/0 Ethilon sutures. Nevertheless, the authors reported a steep learning curve to reach this level of dexterity.13 The challenge lies in avoiding the risk of catching the vessel’s backwall (a limiting factor particularly in very small caliber lumens) instead of relying on the conventional microsurgical arc of needle movement (Fig. 1). In this video article, we employ a method (inspired by the katana-wielding technique “Tsubama Gaeshi”14 and akin to the knight’s movement in chess, hence the term) to challenge the notion that supermicrosurgery is not possible with conventional microsurgery instruments.Fig. 1.: Conventional microsurgical anastomotic technique.METHODS In a case-control study of a chicken wing ex vivo model15 based on the ulnar artery (UA) and its side-branch, the recurrent ulnar artery (RUA), we compared the outcomes across 60 anastomotic sites (Fig. 2). These were divided into 2 groups: the microsurgery control UA group involving E-E anastomoses of the chicken UA (n = 20) and the supermicrosurgery RUA group, which in turn was categorized into 2 sub-cohorts—20 anastomoses of the end-to end (“E-E”) RUA segments (n = 20) and end-to-side (“E-S”) RUA-UA segments, respectively (n = 20). A conventional “one-way up” microsurgical technique was used in the UA control group, while the knight’s move technique (Fig. 3) was used for the supermicrosurgery group.Fig. 2.: Photograph showing the anastomosis sites of the UA E-E (the control group) and those of the RUA E-S and RUA E-E sub-cohorts.Fig. 3.: Place 2 opposing sutures at 180 degrees to iron out any anastomotic mismatches (Steps 1 and 2). Next, push the needle point almost parallel through the proximal vessel wall before sliding it along its length between the opposing walls of the opposite lumen, rotating its tip by 90 degrees and exiting perpendicular to the opposite vessel wall. This is repeated in a double loop suture method (Steps 3 and 4) before twisting the vessel around and repeating the process (Steps 5 and 6).All anastomoses were performed using standard microsurgery instruments (Steth2scalpel.com Limited, London, UK), comprising only a needle-holder, a curved micro-scissor, jeweler’s forceps, and a vessel dilator, while the surgical sutures used were 10/0 (0.2 Metric, Art. No. 03174; Art. Code 7V43) S&T Nylon sutures with a 70-μm diameter 3/8 needle (S&T, Switzerland), as shown in the Supplemental Video. (See Video [online], which displays the recurrent ulnar artery super microsurgery model.) {"href":"Single Video Player","role":"media-player-id","content-type":"play-in-place","position":"float","orientation":"portrait","label":"Video 1.","caption":"Microsurgery model technique. Video 1 from “A Case-Control Analysis of The Knight’s Move Technique In A Chi