Intraoperative Real-Time Visualization of the Lymphatic Vessels Using Microscope-Integrated Laser Tomography

Abstract

Background Detection and selection of the lymphatic vessels are important for maximizing therapeutic efficacy of lymphaticovenular anastomosis (LVA). Some imaging modalities have been reported to be useful for intraoperative identification of the lymphatic vessels, but they have limitations. In this article, we present new capabilities of intraoperative laser tomography, which was used to evaluate the lumen of the lymphatic vessel and to validate the patency of anastomosis. Patients and Methods Fifty-two patients with upper extremity lymphedema secondary to breast cancer treatment underwent indocyanine green (ICG) lymphography and real-time laser tomography imaging of ICG-enhanced lymphatic vessels intraoperatively before transecting the vessels during LVA. The imaging findings of the lymphatic vessels in laser tomography were investigated. Time required for scanning of the lymphatic vessels was compared between laser tomography and ultrasonography. The correlation between the thickness of the lymphatic vessel wall measured with laser tomographic imaging and the histologically measured thickness of the lymphatic vessel wall was examined. The patency of anastomosis sites was determined based on the image using laser tomography immediately after establishment of LVA. Results A total of 132 ICG-enhanced lymphatic vessels were scanned with laser tomography showing clear lumen with surrounding vessel wall. The required time for lymphatic vessel scanning was significantly shorter with laser tomography than with ultrasonography (1.6 ± 0.3 vs. 4.8 ± 1.2 minutes; p = 0.016). Strong correlation was seen between the thickness of the lymphatic vessels wall measured using laser tomography and the histologically measured thickness of the lymphatic vessel wall (r = 0.977, 95% confidence interval: 0.897–0.992, p < 0.001). The quality of patency was evaluated immediately after anastomosis, which assisted in deciding whether reanastomosis was needed. Conclusion Microscope-integrated laser tomography provides real-time images of the lymphatic vessels in extremely high resolution and enables evaluation of lymphatic lumen condition and objective post-LVA anastomosis status.

Long-term Use of Ultrasound for Locating Optimal LVA Sites: A Descriptive Data Analysis

“…However, recent studies revealed that microscope-integrated laser tomography is superior to US in terms of intraoperative evaluation. 39 One of our limitations is that lower extremity lymphedema is overrepresented with 48 cases and 184 dissected lymphatic vessels, probably because patients with lower extremity lymphedema suffer more because of gravity. LVA operations were performed on upper extremity lymphedema patients in 13 cases, where 49 lymphatic vessels were anastomosed.…”

“…Another limitation is that US findings depend on the examiner's experience and the examination time. 39 To overcome this limitation, we standardized the examination time to 60 minutes and searched for lymphatic vessels primarily in the fluid-predominant region. This work was performed by the author S.M.…”

Recipient Venule Selection and Anastomosis Configuration for Lymphaticovenular Anastomosis in Extremity Lymphedema: Algorithm Based on 1,000 Lymphaticovenular Anastomosis

“…The anastomosis of such sclerotic lymphatic vessels leads to minimal or no therapeutic effect and therefore the identification of overloaded yet functional lymphatics has crucial importance in LVA surgery. 10 11 12…”

“…The anastomosis of such sclerotic lymphatic vessels leads to minimal or no therapeutic effect and therefore the identification of overloaded yet functional lymphatics has crucial importance in LVA surgery. [10][11][12] However, lymphatics represent only one side of LVA, and the recipient venule (RV) selected influences the efficacy of the anastomosis and the surgical outcome likewise the lymphatic side. 9 Despite that, RV for LVA have been usually neglected in literature.…”

A Novel Real-time Navigation System for Lymphaticovenular Anastomosis Using Projection Mapping with Indocyanine Green Fluorescence

“…For microscopic navigation, a built-in ICG camera system shows the lymphatic vessels and their flow. Moreover, a recent ICG videolymphography system 4 and microscope-integrated laser tomography 5 have the potential to make LVA surgery more accurate and certain. However, for macroscopic ICG navigation, which is performed to detect the best position to make the skin incision and LVA for the whole area of an extremity, we still required a conventional ICG camera system (PDE-neo; Hamamatsu Photonics Co., Ltd, Shizuoka, Japan) displayed on monitors, which means that surgeons must shift their vision between the surgical field and the monitor.…”