Lymphatic regeneration following hind limb replantation: an experimental study in the dog.

Different types of trauma to the lymphatic system can often occur, but surgical intervention can be performed only in specific cases. We report on lymphatic regeneration following limb replantation in traumatic amputations and replantation of extremities. The aim of this study was to observe the progression and reaction after surgical trauma that is similar to other kinds of trauma, both in children or adults, and to monitor the possible lymphatic regeneration. Particular attention was paid to two parameters: firstly, the physical examination of the replanted limbs by checking the post-traumatic lymphoedema, and secondly, the study of the images taken from indirect lymphangiography of the replanted limbs. Histological specimens of the surgical trauma area were also examined to reconfirm or exclude lymphatic regeneration. The study population consisted of sixteen mongrel dogs, divided into two groups of eight animals each, who underwent hind limb elective amputation and replantation combined with (group A) or without (group B) sciatic nerve division. Lymphoedema formation was followed quantitatively by measurement of the circumference of the hind limb for 21 days after replantation. Indirect lymphography, never performed before in such cases, and histopathology, were performed to evaluate and confirm lymphatic regeneration. Lymphatic regeneration after replantation of the operated hind limbs was first confirmed between 7th and 11th postoperative day by indirect lymphangiography and clinical observation of the post-traumatic lymphoedema of these limbs. The mean time of visualisation of lymphatic regeneration through lymphography was 10.12 days for group A and 9.37 days for group B. However, nerve transection had no effect on lymphatic regeneration (p = 0.46). Histopathological examination showed first evidence of lymphatic regeneration on the ninth postoperative day and a network of newly formed capillary lymphatics on the 21st postoperative day. It is concluded that lymphatic regeneration following replantation of the extremities without anastomosing of the interrupted lymph vessels, is an unquestionable fact. To achieve the best lymphatic drainage and use of the replanted extremities it is important to resect all non-vital tissues of the replantation area. Local or general infections decelerate lymphatic regeneration. Indirect lymphography with iotrolan is a reliable, easy to perform technique without complications that may be used repeatedly for confirmation and evaluation of post-traumatic lymphoedema.