The first publication is an exhaustive review of lymphaticovenous anastomoses, which analyses the clinical implications of lymphedema surgery. This review forms the starting point for the research detailed in the second publication, which aims to demonstrate the existence of intratissue physiological lymphaticovenous communications. The research model needed to achieve this goal was defined following two pilot studies. We began by investigating the presence of intratissue lymphaticovenous communications in the adipose tissue of submental, supraclavicular and inguinal flaps in a cadaveric morphological model. FIRST PAPER The prevalence of breast cancer-related lymphedema has been estimated at 21%. Reconstructive techniques for lymphedema include microsurgical lymphaticovenous anastomosis and vascularized lymph node transfer. Although these techniques do not reverse the pathophysiology of lymphedema, they can improve lymph transport, partially decompress the interstitial space, and delay the progression of structural changes. The prevalence of lymphaticovenous communications has been found to be lower in normal people than in patients with pathologies of the lymphatic system, suggesting the existence of a compensatory mechanism. Understanding the function of the different types of lymphaticovenous communications will in turn allow us to understand the mechanism of action of lymph node flaps, which drain lymph from the lymphedematous limb to the blood circulation through lymphaticovenous communications within the lymph nodes. Our review suggests that the tissue surrounding the lymph nodes in a lymph node flap is active and contains intratissue lymphaticovenous communications. Another fundamental factor to be considered in the functioning of lymphaticovenous communications in the recipient site area is venous pressure. Venous pressure is lower in proximal than distal recipient sites, and so it must be controlled when planning and performing vascularized lymph node transfer. In this paper, we review and discuss the physiology and pathophysiology of lymphaticovenous communications. SECOND PAPER Background: Vascularized lymph node transfer has shown beneficial effects as a surgical treatment for cancer-related lymphedema. However, the mechanism of action of this procedure is not fully known. Objectives: To investigate the existence of intratissue lymphaticovenous communications in free flaps used for breast reconstruction. Materials and Methods: A prospective observational study determining the passage of lymph to the venous system via intratissue lymphaticovenous communications in a total of 26 free flaps (22 DIEP and four SGAP) used for breast reconstruction. The study was carried out at the Plastic Surgery Department of the Hospital de la Santa Creu i Sant Pau from October 2014 to September 2015. Fluorescence positivity was assessed in the pedicle vein after increasing time intervals (5, 30, 45, 60 and 120 min) following intradermal injection of indocyanine green (ICG) dye into the flaps using near infra-red fluorescence imaging. Statistical analysis was performed using SPSS 23.0 software. Results: Fluorescence in the pedicle vein was positive in 22 of the 26 free flaps studied (p = 0.000). The median time for fluorescence evaluation in the pedicle vein was 120 min. The analysis of the time between flaps did not indicate a statistically significant effect (p=0.558), even when only positive results were considered (p=0.093). Conclusions: The fluorescence in the pedicle vein after indocyanine green intradermal injection indicates the presence of functional intratissue lymphaticovenous communications in the free flaps studied because the lymphatic system was disrupted during its dissection, and also because indocyanine green binds to large proteins and cannot cross the walls of the blood vessels.
Anastomosis linfático-venosas naturales y su papel en la cirugía del linfedema
María del Carmen, M. G. (Author). 26 Sept 2017
Student thesis: Doctoral thesis
Student thesis: Doctoral thesis