Keywords
lymphaticovenular anastomosis - lymphaticovenous anastomosis - supermicrosurgery -
vessel loop - micro-ligaclip
Introduction
Supermicrosurgery is a term first defined by Masia et al in 2010[1] in which special techniques are required for vessels smaller than 0.8 mm in size.
The advent of the supermicrosurgery era has allowed us to treat lymphedema from a
new angle, that of lymphaticovenular anastomosis (LVA). With recent advances in imaging,
microscope, and operating instruments, such as ultrasound-guided LVA, indocyanine
green (ICG) videolymphography,[2]
[3] we can now identify finer lymphatics and perform LVA on vessel calibers that were
once thought impossible. The prerequisite for performing an LVA is a good eye for
identification of the lymphatic vessel and vein. As lymphatic vessels can be notoriously
translucent, the search for one adds to the complexity of the surgery. Having to find
a vein that is of a good match to set the stage for a successful LVA is another. As
the vessels become smaller in size, the ability of the surgeon to manipulate the vessel
in an atraumatic manner also becomes harder. Repetitive grasping can lead to fracturing
of the vessel, forcing the surgeon to commit to a short length for anastomosis, or
even abandon it altogether. In routine microsurgery, vessel loops that are 0.8 mm
in diameter are used to manipulate vessels atraumatically. However, such silicone
loops are too big to use on lymphatic vessels. Hence, we propose a novel technique
of using a nylon suture as a vessel loop that can be used to tag the lymphatic channels,
to simplify the process of lymphatic vessel identification during surgery.
Method
We collected retrospective data of all patients who underwent LVA in our center from
June 2020 to December 2021 in this case series, whether primary or secondary LVA,
when the main surgeon started utilizing this technique during LVA.
This method was used by the senior author in all his LVA cases. When a potential lymphatic
vessel has been identified, a nylon 6–0 suture is used to loop around the vessel,
and cut to a length of approximately 1.5 cm ([Fig. 1]). To secure and fix the loop, both ends of the suture is secured together with a
micro-ligaclip ([Fig. 2]). Thus, the loop encircles the lymphatic vessel ([Fig. 3]). This is done with caution such that the lymphatic vessel is not injured or twisted
by accident. By holding the loop with the Jeweller's forceps, the surgeon does not
have to directly grasp the lymphatic vessel to manipulate it, hence minimizing trauma
and unwanted transection After identifying all the lymphatic vessels and veins, the
surgeon decides which lymphatic vessel and vein is the best, and the LVA is then performed.
The success of the LVA is determined by direct visualization of clear lymphatic fluid
from the lymphatic vessel into the venule. At times when the lymphatic fluid flow
is not clear, ICG lymphography was performed with our microscope to determine the
patency of the anastomosis.
Fig. 1 Nylon 6–0 sutures placed under the lymphatic vessel (blue lines).
Fig. 2 Jeweller's forceps point to the micro-ligaclip that is used to secure the ends of
the nylon suture. Three vessel loops are shown in the picture.
Fig. 3 Vessel loop encircling the lymphatic vessel.
Results
We included a total of 26 patients, with 78 LVAs, from June 2020 to December 2021.
All of these patients were females with breast cancer. The senior author performed
prophylactic LVA for the patients who underwent axillary clearance. ICG was injected
into the webspace of the digits of the ipsilateral hand of the axillary clearance
performed. The lymphatic vessels are then mapped out on the arm with a marker pen.
The senior author then performed LVAs in the forearm or upper arm depending on where
the lymphatic vessel was located. The mean age of the patients was 54 years (range:
35–79 years). The body mass index of these patients was 25.2 (range: 18.7–33.8). The
average lymphatic vessel size was 0.3 mm (0.15–0.8 mm). [Table 1] shows the type of breast surgery and the location of the LVAs performed in patients
who underwent breast surgery. All LVAs have been shown to be patent either by direct
visualization of lymphatic fluid into the vein or with the use of ICG after the initial
anastomosis has been performed.
Table 1
Demographics of patients
|
Type of surgery
|
Location of LVA
|
No. of patients
|
No. of anastomoses performed
|
|
Skin sparing mastectomy
|
Left upper limb
|
9
|
26
|
|
Right upper limb
|
10
|
31
|
|
Nipple sparing mastectomy
|
Left upper limb
|
2
|
5
|
|
Right upper limb
|
2
|
6
|
|
Lumpectomy
|
Right upper limb
|
1
|
3
|
|
Chest wall resection
|
Left upper limb
|
2
|
7
|
|
Total
|
|
26
|
78
|
Discussion
The use of vessel loops in plastic surgery has a myriad of uses. This ranges from
identification of vessels, nerves, or tendons, atraumatic retraction on perforators
during dissection to even closure of fasciotomy wounds with the use of larger vessel
loops.[4]
When searching for and identifying lymphatic vessels, care should be undertaken to
minimize direct handling of the lymphatic itself to avoid injury to the vessel. Any
injury to the lymphatic vessel can result in damage, which may then preclude the use
the lymphatic vessel in LVA. The smallest diameter of vessel loops that are available
commercially is 0.8 × 406 mm (Aspen Surgical, United States). In addition, the vessel
loops are heavier; hence, the pure mass of the vessel loops may cause the lymphatic
vessel to fracture, whereas the nylon suture is not as thick. As such, these vessel
loops are not ideal to be used to tag the lymphatics due to the high risk of injury
to the vessel. Thus, the use of nylon suture as a vessel loop to improve the visibility
of the lymphatic will aid in the overall operation.
This novel technique of creating a vessel loop with the use of a nylon 6–0 suture
and micro-ligaclip has been employed by the main surgeon for 90 LVAs in 30 cases,
and has been shown to be successful. The patency of each LVA was checked by visualization
of the flow of clear lymphatic fluid into the vein or through the use of ICG.
The use of this technique is meant to identify and simplify the manipulation of the
lymphatic vessel. Lymphatic vessels can be notoriously translucent, so this technique
is used to “tag” the lymphatic vessel for easy identification. Using this technique,
the surgeon does not have to worry about not being able to find the previously identified
lymphatic, and can proceed to look for other lymphatics for the LVA. When all the
potential lymphatic vessels and veins have been identified, the surgeon can select
the best match. This is akin to performing an inventory of available lymphatic vessels
and venules, and streamlines the process of identifying structures that we can go
back to later. Much like the management of the spaghetti wrist, tagging structures
saves time and minimizes the need to go back to search for it.[5]
This technique is also used to allow manipulation of the lymphatic vessel during the
surgery. Gentle traction on the vessel during LVA helps provide the necessary tension
on the vessel to identify the lumen before the anastomosis.
However, the authors do acknowledge that it may be difficult to attribute the success
of the patency of the LVA solely to the use of this technique as there are many factors
such as surgeon's expertise and tissue handling that may affect the end result of
the anastomosis. Also, the use of our technique for lymphatic handling requires practice,
as placing the suture and using the micro-ligaclip to create the loop can result in
more damage than good if the vessel is not handled well. Also, use of silicone loops
for lymphatic identification has been described in the literature,[6] but not with the use of nylon suture, which is smaller and more delicate for the
fragile lymphatic vessel.
Conclusion
This novel technique to implement the use of a nylon suture with a micro-ligaclip
to use as a vessel loop for lymphatics has not been previously described in the literature.
It is a useful technique that we find beneficial for identification of the lymphatics,
so as to select the best matched lymphatic vessel to set the stage for a successful
LVA. This technique also aids in careful manipulation of the vessel to reduce lymphatic
injury. All of these benefits contribute to a successful LVA.
