Vascularized axillary lymph node transfer: A novel model in the rat

Abstract

Vascularized lymph node transfer (VLNT) is a promising microvascular free flap technique for the surgical treatment of lymphedema. To date, few experimental animal models for VLNT have been described and the viability of lymph nodes after the transfer tested. We aimed to evaluate the feasibility of axillary VLNT in the rat. Lymph node containing flaps were harvested from the axillary region in 10 Lewis rats based on the axillary vessels. Flaps were transferred to the ipsilateral groin and end-to-side microanastomosis was performed to the femoral vessels using 10-0 sutures. Indocyanine green (ICG) angiography was used to confirm flap perfusion. On postoperative day 7, flaps were elevated to assess their structure and vessel patency. Hematoxylin and eosin staining was used to confirm the presence and survival of lymph nodes. All animals tolerated the procedure well. Immediate post-procedure ICG angiography confirmed flap perfusion. No signs of ischemia or necrosis were observed in donor extremities. At postoperative day 7, all flaps remained viable with patent vascular pedicles. Gross examination and histology confirmed the presence of 3.6 ± 0.5 lymph nodes in each flap without any signs of necrosis. This study showed that the transfer of axillary lymph nodes based on the axillary vessels is feasible. The flap can be used without the need for donor animals and it contains a consistent number of lymph nodes. This reliable VLNT can be further utilized in studies involving lymphedema, transplantation, and induction of immunologic tolerance.

Lymphatic Territories (Lymphosomes) in the Rat: An Anatomical Study for Future Lymphatic Research

“…21 Several new VLNT donor sites were introduced in rats and functional mechanism was investigated. 22-25 In addition, the patency of lymphovenous anastomosis was studied in rat models and lymphatic structural changes after surgical manipulation were investigated using ICG fluorescence lymphography. 15,26-29 Different patterns of ICG fluorescence lymphography in lymphedema patients were investigated in relation to pathological changes in the lymphatic vessel.…”

Feasibility of pedicled vascularized inguinal lymph node transfer in a mouse model: A preliminary study

“…Despite its growing popularity in lymphedema treatment (Becker et al, ; Cheng et al, ; Gharb et al, ; Ozturk et al, ; Saaristo et al, ), experimental evidence of the need for vascularization of transferred lymph nodes is lacking. The few small animal models of vascularized lymph node transfer that allow histological evaluation of the transferred lymph node are presently limited to rats (Kwiecien et al, ; Rabson, Geyer, Levine, Swartz, & Futrell, ; Shesol, Nakashima, Alavi, & Hamilton, ; Uygur et al, ).…”

Quantity of Lymph Nodes in the Vascularized Lymph Node Transfer Influences Its Lymphaticovenous Drainage

“…Twenty-seven axillary lymph node flaps were elevated based on the axillary artery and vein as previously described. 23 A skin incision was made at the anterior axillary line and the pectoralis muscle was retracted medially to allow better visualization of the axillary region. Brachial, axillary, and lateral thoracic vessels were then identified.…”

“…The lymphatic structures were identified using operating optical microscope (Leica Wild M-690, Leica Microsystems GmbH, Wetzlar, Germany) and anatomic landmarks. 23 Rats typically have three to four axillary lymph nodes located along the lateral thoracic vessels. 23,24 The predictable pattern of lymphatic drainage through these lymph nodes has been shown in previous studies.…”

“…23 Rats typically have three to four axillary lymph nodes located along the lateral thoracic vessels. 23,24 The predictable pattern of lymphatic drainage through these lymph nodes has been shown in previous studies. 24 The consistency in lymph node quantity, location, and drainage make their clinical identification under the operating microscope possible.…”