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not necessarily induce LFS, although considered the first pathological event leading to secondary lymphoedema. The regeneration of lymphatic pathways and the occurrence of FLSP, especially “perforating vessels”, in a rat, seem to be the key to prevent LFS and secondary lymphoedema. Consequently, it is important to stimulate the appearance of FLSP and to improve lymph flow with mechanical actions like manual lymphatic drainage or innovative technologies such as horizontal stochastic modulated vibrations (Andullation®).
Key Words: Axillary nodes dissection, substitution pathways, perforating vessels, ICG, stochastic vibrations, Andullation technology.
INTRODUCTION
In 2006 breast cancer was the most common diagnosed cancer
in Europe (429.900 cases) representing 28.9% of all cancer cases in European women (Ferlay et al., 2007).
Early detection and treatment strategies of breast cancer have improved over the last years and resulted in higher survival rates. Consequently, more attention is paid to the complications of breast cancer treatment and especially Breast Cancer Related Lymphoedema (BCRL). McLaughin (2012) mentions a general BCRL incidence of 6 to 70%. Although the appearance of the BCRL is multifactorial, Axillary Node Dissection (AND) during breast cancer surgery is considered the major risk factor (Kim et al., 2013; McLaughlin, 2012; Tsai et al., 2009).
To study the effects of AND on the lymphatic system and the subcutaneous tissues at the operated side, animal models are essential (Hadamitzky and Pabst, 2008). However, standardized secondary lymphoedema animal models following axillary resection are rare. Rats appear to be the most appropriate laboratory animals to perform such evaluations (Hadamitzky and Pabst, 2008). Till now, different techniques were tested for creating an “in vivo” rat model of chronic secondary lymphoedema (Becker C, 1987), but turned out to be very difficult without additional chemical inflammatory agents (Becker C, 1987; Mendez et al., 2012) or auxiliary physical techniques such as radiotherapy (Kanter et al., 1990; Lee-Donaldson et al., 1999; Ogata et al., 2007). As a consequence, the complete anatomical and pathophysiological aspects leading to the development of secondary lymphoedema following solely AND have not been completely elucidated. In a recent mice model on AND, lymphatic fluid stasis (LFS) appeared to be the primary pathological vascular change 3 weeks following surgery leading to the appearance of markers which are associated with specific subcutaneous tissue changes occurring during chronic secondary lymphoedema in humans (Aschen et al., 2012). The present available information on the influence of AND only concerns its influence on the morphological aspect of the lymphatic system following longer post-operative periods.
In humans, the prevention and physical treatment of BCRL following axillary node dissection (AND) mainly consist in improving the lymph flow. It aims at avoiding lymphatic fluid stasis within the operated upper limb to prevent secondary lymphoedema. Manual lymphatic skin massage is the main modality of this physical treatment (Lympho, 2013) but the application of locally applied mechanical induced vibrations
THE EUROPEAN JOURNAL OF LYMPHOLOGY - Vol. XXIX - Nr. 75 - 2017
demonstrated positive effects on the lymphatic system. In 2007, a new technique of whole body vibration was introduced for medical applications (Germonpre et al., 2009). The innovative Andullation technology combines infrared light with stochastic modulated vibrations. The two biophysical treatment modalities are applied simultaneously to an individual in the horizontal position on a massage mattress. Massage by mechanically induced vibrations in the recumbent position is of interest as a potential additional prevention and /or treatment method in pathological conditions where vascular and/or lymphatic circulatory systems are compromised.
Two fundamental studies are presented. The objective of the first study is to evaluate the morphological effects of a total AND in the front paw of a rat (volume changes) in order to detect LFS and FSLP in the subcutaneous tissues 12 weeks following surgery. The aim of the second study is to investigate the effect of a short exposure of multidirectional vibrations generated by Andullation technology on the lymphatic system in rats in the horizontal position.
MATERIALS AND METHODS
Part 1
The experiments were approved by the ethical committee on animal welfare of the Vrije Universiteit Brussel (VUB).
Females Wistar rats (N=40, average weight 202 ± 8 grams) were selected for this study and randomly allocated in 2 groups, an experimental group (N=30) and a control group (N=10).
At Day One, the volume of both shaved distal paws of each anesthetized animal (3 minutes induction phase: O2 at 1l/min, Isoflurane at 5 % and maintenance phase: O2 at 0.5 l/min, Isoflurane at 1.5-2%) was assessed with an artisanal plethysmometer based on pressure measurements (Fig. 1). The elbow of the stretched front paw was selected as reference marker. Due to the inconsistent shape of the arm and shoulder, only the volume of the paw extremity below the elbow was measured. Pressure variations were recorded with a blood pressure sensor (BP-100, World Precision Instruments, United Kingdom) connected to a data acquisition system (iWorx® AHK/214S, USA) with LabScribe3 software interface (Graph 1). The distal paw volume (ml) was calculated with the following formula [Vol (ml) = D (mmHg) / 0,1701] which was obtained after device calibration (Graph 2) based on measured pressures (mmHg) according to various known volumes (ml).
Fig. 1 - Artisanal plethysmometer (picture on the left) and paw immersion (B and C).
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