Sutureless Microvascular Anastomoses by a Biodegradable Laser-Activated Solid Protein Solder

Abstract

A new sutureless technique to successfully anastomose the abdominal aorta of rats (1.3 mm in diameter) by using a fully biodegradable, laser-activated protein solder is presented. A total of 90 rats were divided into two groups randomly. In group one, the anastomoses were performed by using conventional microsuturing technique, whereas in group two, the anastomoses were performed by using a new laser welding technique. In addition, each of the two groups were divided into five subgroups and evaluated at different follow-up periods (10 minutes, 1 hour, 1 day, 1 week, and 6 weeks). At these intervals, the anastomoses were evaluated for patency and tensile strength. Three anastomoses in each subgroup were processed for light and electron microscopy. All anastomoses were found to be patent. The mean clamp time of the anastomoses performed with conventional suturing was 20.6 minutes compared with 7.2 minutes for the laser-activated welded anastomoses (p < 0.001). The strain measurements showed a stronger mechanical bond of the sutured anastomoses in the initial phase. However, at 6 weeks the tensile strength of the laser-welded anastomoses was higher compared with the conventional suture technique. Histologic evaluations revealed a near complete resorption of the solder after 6 weeks. The junction site of the vessel ends cannot be determined on the luminal side of the artery. In conclusion, a resorbable protein used as a solder, activated by a diode laser, can provide a reliable, safe, and rapid arterial anastomosis, which could be performed by any microsurgeon faster than conventional suturing after a short learning curve.

Adhesive biomaterials for tissue reconstruction

“…70 -73 Maitz et al used tubes of solid albumin solder (length ∼2 mm, diameter ∼1.3 mm) to successfully anastomose the abdominal aorta of rats. 74 The anastomoses (n = 45) were performed by inserting the tube between the aorta ends with a 'foldback maneuver' and using a diode laser (λ = 808 nm) with an irradiance of ∼286 W cm −2 . In the control group, the anastomoses (n = 45) were performed by using conventional micro-suturing technique.…”

Laser‐assisted end‐to‐end bioweld® anastomosis in an ovine model

“…A range of diameters was available to the surgeon, and each tube selected was size matched by caliper to its destination artery (external vessel diameter/internal BioWeld 1 diameter). The BioWeld 1 tube was placed over the distal carotid stump, which was then dilated and everted over the BioWeld 1 tube in a maneuver previously described as the ''foldback'' [7][8][9]. Laser energy was applied in a paintbrush style, via a 200 mm fiber, to the everted carotid stump with an 810 nm continuous wave diode laser at 500 mW, welding the foldback to the BioWeld 1 tube.…”

“…Where microvascular anastomoses are required, laser-assisted techniques can reduce operative time, surgical skill, foreign-body reaction, trauma to the vessel wall and blood leakage at the anastomotic site [2,6]. For this purpose our group (AVASTRA) has developed the BioWeld 1 tube, a protein-based, implantable, biodegradable device to facilitate end-to-end laser-assisted anastomoses [7,8]. BioWeld 1 is a solid, tubular albumin-based exo-vascular stent.…”

“…Indocyanine green (ICG) dye is incorporated into the BioWeld 1 tube in order to maximize laser absorption at the anastomosis, while minimizing collateral thermal damage associated with the laser. The BioWeld 1 tube has been investigated extensively and successfully in small arteries, less than 2 mm, for use in end-to-end anastomosis [7,8].…”

Intraluminal laser light source and external solder: In vivo evaluation of a new technique for microvascular anastomosis

“…This technique is advantageous for two-dimensional adaptation of skin lacerations, it however, encounters some handling problems especially when performing anastomosis of small vessels, which require a three-dimensional approach in terms of revolving either the laser source or the vessel by 3608. Furthermore, either stay sutures [19] or intraluminal stents [17,20,21] must still be applied to align the separated vessel ends.…”