Page 26 - Read Online

Page 6 of 15 Ali et al. Plast Aesthet Res 2021;8:35 https://dx.doi.org/10.20517/2347-9264.2021.29

There are criticisms for the use of microvascular couplers, the most significant being the additional cost in
using this technology. The cost is higher than that of microvascular sutures, however, this may be mitigated
by the operation time saved when utilizing a coupler device. A study exploring the economic cost of
microvascular couplers found that the coupler device increased the initial cost by $284.40. However, when
the reduction of operative time (16.9 min) was factored, $234.89 of savings was estimated with each coupler
[31]
anastamosis .
The use of microvascular coupler for the artery has been more controversial. Arteries can be technically
challenging to couple due to the lack of pliability and difficulty everting the arterial tissue over the pins.
Arteries have thicker walls and may be affected by atherosclerotic disease and radiation induced thrombosis
in patients with prior radiation to the field. Earlier literature on microvascular coupling of the artery has
reported concerns for increased thrombosis rates [32-34] . However, recent studies have provided more support
for arterial coupling. In a systematic review of microvascular couplers used in arterial anastomosis,
[35]
Gundale et al. reported good success rates with low rates of thrombosis. In this study, the rate of
thrombosis with arterial coupling was reported to be 1.9%. Additionally, computational fluid dynamic
models have shown a more thrombogenic profile in a sutured anastomosis when compared to a coupled
vessel .
[36]

There are novel devices engineered to assist with microvascular arterial coupling. The vessel everter device
assists with securing the arterial wall to the coupler pin. As mentioned earlier, the thicker walls of the artery
makes it difficult to sequentially couple the arterial vessel wall over the pins. The everter device helps to
[37]
overcome this challenge by simultaneously everting and securing the arterial wall over the coupler pins .
This vessel coupler is used with the microvascular coupler. It is indicated for coupler sizes 2.0 to 4.0 mm and
not recommended for smaller sizes. It is also contraindicated in patients with silicone allergies. The
instrument is shaped like a pen with a silicone tip that tapers distally. The tip is designed to fit into the end
of the artery and compress the arterial wall and silicone elastomer to the engaged pins. The instrument is
then withdrawn leaving the vessel wall engaged onto the pins. Preliminary animal studies using the device
have shown successful arterial anastomosis more easily and efficiently with comparable outcomes to hand-
suturing . This device is currently undergoing evaluation for commercial availability (Synovis Micro
[37]
Companies Alliance, Birmingham, AL).

There are several scenarios where microsurgeons should be cautious in utilizing arterial couplers. This
includes situations of significant atherosclerotic or radiated vessel where intimal injury can result from
eversion onto a coupler pin. In addition, some literature warns against coupling arteries where there is
significant vessel mismatch (greater than 1.5:1 diameter mismatch) and arteries less than 1.5 mm in
diameter [38,39] . The preference at our institution is to use the microvascular coupler for the vein and hand-
suture the artery. However, we have found situations where the arterial coupler is valuable including in
salvage settings where initial hand-suturing resulted in arterial anastomotic thrombosis .
[40]
Three-dimensional exoscope
Magnification is necessary for FTT and has been traditionally accomplished through the use of operating
microscopes or surgical loupes. The 3D stereoscopic camera based viewing systems are the newest
technology allowing for such magnification. This technology is also referred to as extracorporal telescopes,
or exoscopes. The system consists of a compact high definition 3D camera placed approximately 20 to
50 cm above the surgical field. A sterile cover is placed over the 3D camera and controller allowing the
surgeon to make adjustments in position, zoom, and focus. The real-time image is projected onto one or
more 3D high-resolution monitors placed in front of the surgeon. 3D polarization glasses are worn by the