ABSTRACT
The regeneration of anastomosed aortas after radiotherapy and chemotherapy was studied by light, scanning, and transmission electron microscopy in a rat model. At the ultrastructural level, it was observed that sublethal doses of these methods of cancer treatment did not severely block endothelial proliferation in the region of the microanastomosis. Based on the experimental results, myocutaneous free flap transfers were completed in patients with malignant tumors who had been undergoing radiotherapy and chemotherapy to cover defects resulting from their excision.
Subject(s)
Anastomosis, Surgical , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Endothelium, Vascular/drug effects , Endothelium, Vascular/radiation effects , Microsurgery , Regeneration/drug effects , Regeneration/radiation effects , Surgical Flaps/pathology , Wound Healing/drug effects , Wound Healing/radiation effects , Adult , Animals , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Aorta, Abdominal/drug effects , Aorta, Abdominal/radiation effects , Aorta, Abdominal/surgery , Combined Modality Therapy , Endothelium, Vascular/pathology , Humans , Male , Melanoma/drug therapy , Melanoma/radiotherapy , Melanoma/surgery , Microscopy, Electron, Scanning , Neoplasm Staging , Radiotherapy Dosage , Rats , Rats, Wistar , Skin Neoplasms/drug therapy , Skin Neoplasms/radiotherapy , Skin Neoplasms/surgeryABSTRACT
Intimal regeneration in the region of microvascular suture of the rat aorta was investigated by LM, SEM and TEM. Endothelial integrity was restored by endothelial cells from the defect edges. No thrombotic masses took part in the formation of the intimal thickening. It is supposed that the core of the intimal thickening formation is a transition of regenerating smooth muscle cells along elastic "railes" from media into intima.
Subject(s)
Aorta/pathology , Regeneration/physiology , Sutures , Animals , Aorta/physiology , Aorta/surgery , Male , Microsurgery/instrumentation , RatsABSTRACT
By means of scanning electron microscopy of chemically extracted preparations the dynamics of changes in the three-dimensional structure of the internal elastic membrane (IEM) of the rat aorta has been investigated after its lesion by a vascular clip. The mechanical lesion results in rupture of the IEM along external borders of the instrument lips and in crushing of its central part. A niche is formed, along its periphery it is surrounded with a practically intact IEM. The aorta regeneration is accompanied with neoelastogenesis. In the center of the niche newly formed elastic structures appear later, but the IEM reparation develops more actively. During the neoelastogenesis some stages are distinguished: at first separate elastic fibers appear, which then anastomosed, uniting into fasciculi and laminae. It is supposed that the IEM-restoration at regeneration depends on synthetic activity of smooth myocytes and on the other hand, the changes in the IEM structure can regulate their migration and metabolism.
Subject(s)
Aortic Rupture/pathology , Elastic Tissue/injuries , Animals , Aorta, Abdominal/injuries , Aorta, Abdominal/physiopathology , Aorta, Abdominal/ultrastructure , Aortic Rupture/physiopathology , Constriction , Elastic Tissue/physiopathology , Elastic Tissue/ultrastructure , Male , Microscopy, Electron, Scanning , Rats , Rats, Inbred Strains , Wound Healing/physiologyABSTRACT
In experiments with rats, abdominal aorta was subjected to microsurgical anastomosis after local irradiation with doses of 40 and 50 Gy. Irrespective of the time interval between the operation and irradiation the iatrogenic defect was restored completely. With the operation performed 24 h after irradiation the platelet adhesion decreased, the proliferation was inhibited depending on radiation dose, and the pattern of the endotheliocyte migration changed. The above effects were absent with the operation performed one month after irradiation.
