Observation of lymphatics with Indocyanin Green

Observation of lymphatics with Indocyanin
Green – Do we need new anatomy books?
J. P. Belgrado, L. Vandermeeren, S. Vankerckhove, J. B. Valsamis
Université Libre de Bruxelles, Faculté des Science de la Motricité, Unité de
Recherche en Lymphologie, CHU St. Pierre, Clinique de Lymphologie de Bruxelles
Introduction
The quest of imaging the superficial lymphatic network with the help of contrasting products started already more than 200 years ago. Because of the
physiological specificity, the limpidness and the smallness of lymphatic vessels,
researchers have always had a difficult task in the search of a specific tracer,
which could be sensitive and specific enough for lymphatics, minimal invasive,
affordable and suitable for in vivo examinations.
Fig. 1:
Indocyanine Green Imaging of lymphatics.
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Observation of lymphatics with Indocyanin Green
Indocyanine Green (ICG), a well-known fluorescent dye, already used in angiology, cardiology and hepatology, and recently in lymphology, completes in
an original manner the arsenal of imaging tools to study lymphedema and the
superficial lymphatic system in human. Macroscopic anatomy description of the
superficial lymphatic collector’s architecture has to be revisited in lymphede­
matous conditions.
Visualize the superficial lymphatic network architecture
A specific camera equipped with infrared diodes and adapted filters makes possible to visualize the superficial lymphatic network architecture and the lymph
propagation in real time.
a
b
Fig. 2:
a) Initial lymphatic network is not visible, it drains normally into functional lymphatic collectors
which are visible. b) The lymph moves towards the initial lymphatics enlarging the vessels and
making them visible. (Adapted illustrations from Prof. E. Földi, D-Hinterzarten, by courtesy)
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Observation of lymphatics with Indocyanin Green
We report our experience based on 526 lympho fluoroscopies, realized
during the evaluation of primary and secondary lymphedema and experiences
on healthy subjects.
After intradermal injection of a small volume of highly diluted ICG (0.2 ml)
the dye binds with albumine and the local lipoproteins (LP). Those proteins and
fluid localized in the interstitium (the place the edema is situated) reach the
circulation by the lymphatics.
Dynamic images of the lymphatics
During the exam, the camera that emits infrared light excites the couple IGCLP. In these conditions, ICG-LP, diluted into the water of the lymph, starts to be
fluorescent. Then the lymphatic network is revealed to the camera. The signal is
filtered and amplified and shows dynamic images of the lymphatics on a screen.
Fig. 3:
Examination of the dorsum of the hand
of breast cancer related lymphedema
(BCRL).
Fig. 4:
Superficial lymphatics on the dorsum
of the hand (illustration by Sappey).
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Observation of lymphatics with Indocyanin Green
Fig. 5:
Substitution pathways shown by the fluoroscopy. Those pathways can be drawn on the patient’s
skin during the exam.
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Observation of lymphatics with Indocyanin Green
Fig. 6:
Superficial lymphatic observed and video recorded applying various MLD techniques. The lymphatic is located between two reference points (d=50mm).
Fig. 7:
NIR fluoroscopy to improve the knowledge about intermittent compression therapy related to
lymphatic system and develop new concepts.
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Observation of lymphatics with Indocyanin Green
Immediately after the injection, the lymphatic starting from the injected area
became visible, the lymphangion pumping also, then progressively the entire
superficial lymphatic network connected with the injected area and their superficial lymphnodes become visible.
The whole topography of the superficial lymphatic network linked to the injected anatomical region, appears like a dynamic route map that given valuable
information to understand the personal situation of each individual, then customized the therapeutic choice.
Functional vessels appear like a straight line
Anatomical regions which are involved in an edema and where the lymph col­
lectors are not functioning are clearly highlighted: the rerouting of the lymph
that flow through the initial lymphatic appears like a very dense, tortuous and
small vessel network. On contrary, functional vessels appear like straight line,
the efficiency of valves could be tested and contractility of the lymphangion is
perfectly visible. Thanks to dedicated software we measure the mean velocity of
the lymph flow into the lymph collectors.
When the normal lymphatic ways don’t work, the fluid and macromole­cule
are redirected into other functional territories to be drained. This specificity
is also visible during the exam, and it gives information to the therapist how
to change the direction of the manual drainage. On figure 3 (examination of a
breast cancer related lymphedema (BCRL)) is shown that fluid of the dorsum of
the hand reaches the palm and not as normally the dorsum of the wrist.
Beyond the functional information, the fluoroscopy shows the substitution
pathways. Those pathways can be drawn on the patient’s skin during the exam in
order to customize the MLD treatment protocol (Fig. 5). Unexpected functional
lymphnodes and particular reflux could be identified.
Optimize the manual lymphatic drainage techniques
Near infrared (NIR) fluoroscopy helps us also to optimize the manual lymphatic drainage techniques: using a double camera, one in the visible field and the
second in fluorescence. We could observe in real time the efficiency of each manoeuver (Fig. 6).
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Observation of lymphatics with Indocyanin Green
The same could be done to study intermittent compression therapy: we performed studies with customized transparent sleeves for example to evaluate the
lymph flow under the sleeves (Fig. 7).
We observe and record on video the tracer’s progression during drainage
maneuvers. It is possible with this technique to observe the effect of diverse physical treatments such as different manual lymphatic drainage methods, intermittent compression therapy, multicomponent bandages or the wear of sleeves.
Evaluate the occlusion pressure of superficial lymphatic collectors
More recently, fluoroscopy helped us to evaluate the occlusion pressure of superficial lymphatic collectors of the upper and lower limb. The range of the
occlusion pressure reaches values much higher than described in literature.
Because of those findings we should bear in mind that we’ll to review certain
chapters about intra-lymphatic pressure and collapsible properties of lymphatics.
The major advantage of ICG lymphofluoroscopy technique is the possibility
to observe in real-time fluid movements from the interstitial space to the lymphatics, lymph propagation velocity, contraction rate, kinesiology of the lymphangions, mapping of substitution pathways and detection of subclinical lymph­
oedema and “ectopic” lymph nodes in lymphoedema. Protect as more is possible
lymphatics vessels during surgery.
Correspondance address
Jean-Paul Belgrado
Université Libre de Bruxelles
Campus Erasme CP 640
Faculté des sciences de la motricité
Unité de Recherche en Lymphologie
808 Route de Lennik
B-1070 Bruxelles
Belgium
E-Mail: belgrado@ulb.ac.be
© Viavital Verlag GmbH, Köln 2015, Belfortstraße 9, 50668 Köln
www.der-niedergelassene-arzt.de
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