Precise One-Suture Needle-Guided Technique for Window Creation in Supermicrosurgical End-to-Side Anastomosis

Geometric Three-Dimensional End-to-Side Microvascular Anastomosis: A Simple and Reproducible Technique

We have read with great pleasure the recent article by Ooi et al entitled “Geometric three-dimensional end-to-side microvascular anastomosis: a simple and reproducible technique.”[1] The authors' novel design of a V-shaped vesselotomy with geometrically cut end vessel affords an elegant solution to significant microsurgical considerations by reducing the thrombogenicity of high turbulence areas and creating a patch vesselplasty for patency. Nevertheless, as we congratulate the authors for achieving a success rate of 98% for free tissue transfers over a decade, we have found that the formation and management of small structures, such as triangular vessel flaps, becomes significantly more difficult as vessel diameters decrease.

Therefore, we wish to offer our own geometric technique for microsurgical vesselotomies, whose use scales especially well into the vessel diameters of supermicrosurgery. Our simple-to-apply, mathematically-based method is designed to avoid sizing issues which occur with commonly used methods of vesselotomy.[2] Size-mismatched vesselotomies require revisions in additionally cutting or tying which may ultimately compromise the integrity of the anastomosis[3] [4] and should be avoided.

For an ideal anastomosis, a surgeon must create a window of the same diameter, d, as that of the end vessel.[2] [5] As the end vessel lies flat intraoperatively, our assessment is limited to its width, w ([Fig. 1]). This width, w, is approximately of the circumference, C, of the vessel. In addition, we know that C = πd. Therefore, . Solving for d, we find that , concluding that for the best size coherence of both end lumen and side window, a vesselotomy with a diameter two-thirds the width of the flat end vessel is ideal.

Fig. 1 Exposition of the mathematical basis for the measurements used in our technique for end-to-side vesselotomy. Illustrated is a physiologically inflated end vessel, compared with its flattened intraoperative state, as shown by horizontal arrows. Measurements of the inflated diameter, d, and flat width, w, are used in a mathematical proof (Expressions 1–3) to show a vesselotomy with a diameter two-thirds the width of the flat end vessel is ideal for the best size coherence between end lumen and side window.

We apply this knowledge in practice by first comparing the flat end vessel to our suture needle, and noting the distance traced by two-thirds its width. We then place a suture at the desired anastomosis location perpendicularly across the vessel. We tie a floating square knot and cut it with a long tail. Next, we enter the vessel longitudinally along its course, and place entry and exit bites a distance apart, pulling until the needle is halfway through and centered with respect to the previously placed suture and longitudinal bite. Finally, we gently elevate the tied suture, and with curved scissors held point-up, directed perpendicularly to the vessel, cut along the curvature of the suture needle, removing all aforementioned materials from the site ([Fig. 2]). Please view our [Supplementary Video 1] (available in online version only) for a narrated demonstration of this technique.

Fig. 2 Diagrammatic illustration of the intraoperative moment before the side-vessel window is created. A floating square knot has been tied at the center of the desired vesselotomy position and cut with a long tail. A needle has then been passed with entry and exit bites spaced apart, as previously measured compared with the flat end vessel and centered. The center knot has been gently elevated as curved scissors have prepared to cut along the curvature of the needle. This cut will remove all materials and leave a vesselotomy of ideal size for anastomosis with an endvessel of diameter, d.

Supplementary Video 1

This video shows a narrated demonstration of our novel mathematically-based technique for window creation in end-to-side anastomosis in a live rat model.

With this method, we are able to consistently obtain a precise supermicrosurgical window down to 0.3 mm compared with existing Gestalt methods.[2] We believe this to arise from the mathematical basis of our technique, the use of a floating tether for mobility, and the advantages of cutting along a firm suture needle guide. This allows for the full-thickness traversal of the vessel wall, formation of an optimal window, and removal of all support structures. Our method, in theory and practice, results in a simple, novel, and precise technique for creating an optimal window in end-to-side anastomosis and is particularly useful in supermicrosurgical situations where such precision is key.

Disclosures

The authors have no commercial associations or financial interests that may pose or create a conflict of interest regarding the contents of this article.

• References

• 1 Ooi ASH, Butz DR, Fisher SM, Collier ZJ, Gottlieb LJ. Geometric three-dimensional end-to-side microvascular anastomosis: a simple and reproducible technique. J Reconstr Microsurg 2018; 34 (04) 258-263
• 2 Acland RD, Sabapathy SR. Acland's Practice Manual for Microvascular Surgery, 3rd ed. Indian Society for Surgery of the Hand; 2008: 89-90
• 3 Sen C, Hasanov A. Comparative geometric analysis of diamond and hole techniques in end-to-side microvascular anastomosis. Microsurgery 2008; 28 (04) 262-264
• 4 Yamamoto T, Yoshimatsu H, Yamamoto N, Narushima M, Iida T, Koshima I. Side-to-end lymphaticovenular anastomosis through temporary lymphatic expansion. PLoS One 2013; 8 (03) e59523
• 5 Adams Jr WP, Ansari MS, Hay MT. , et al. Patency of different arterial and venous end-to-side microanastomosis techniques in a rat model. Plast Reconstr Surg 2000; 105 (01) 156-161