Vaskularisation von freien myokutanen Grazilislappen im ersatzschwachen Transplantatlager nach präoperativer Radiotherapie Eine experimentelle Untersuchung

Abstract

Following irradiation, vascularization of the soft tissue flaps is both reduced and delayed. This is evidence of delayed healing of soft tissue transplants in transplant beds irradiated prior to surgical interventions. Further optimization of the time interval between radiotherapy and surgery and the total radiation dose are therefore needed.

Histomorphologische Strukturveränderungen von Kopf-Hals-Gefäßen nach prä- oder postoperativer Radiotherapie

“…Nach ablativer Tumorchirurgie werden freie, vaskuläre Transplantate primär oder sekundär zur funktionsorientierten und ästhetischen Rekonstruktion der Hart-und Weichgewebe eingesetzt [5,16,22,27]. Als Ursachen für den Misserfolg derartiger Rekonstruktionen werden eine Reihe von Faktoren wie Alter, Stoffwechselerkrankungen, Alkoholund Nikotinabusus oder eine präoperative Radiochemotherapie angegeben [1,2,[30][31][32]34].…”

Exogenous Modulation of TGF-β1 Influences TGF-βR-III-Associated Vascularization during Wound Healing in Irradiated Tissue

“…It has been shown that total reference doses between 30 and 50 Gy caused lesions in tissues that are comparable to those found in humans after radiotherapy [3]. Preresearch with a total reference dose of 30 Gy, 40 Gy, 50 Gy and fractionation of 3 ϫ 10 Gy, 4 ϫ 10 Gy, 5 ϫ 10 Gy, 10 ϫ 3 Gy, 10 ϫ 4 Gy was carried out to identify the fractionation model corresponding to the clinical situation [30]. Fractionation with 4 ϫ 10 Gy corresponded to the clinical findings of radiobiological changes in cytokine expression profiles and synthesis of ECM components.…”

“…After creating a resection defect, the flap was transplanted into the irradiated neck region and microsurgically reanastomosed to the cervical vessels as previously described [30]. Topical perfusion of the graft and flushing of the operation area and the anastomosis vessels were carried out intraoperatively using 250 units of heparin sodium sulfate (Liquemin ® N 25000, Hoffmann-La Roche, Grenzach-Wyhlen, Germany) with a dilution of 1 : 10 in 0.9% NaCl.…”

“…However, following preoperative radiotherapy woundhealing disorders occur in free soft tissue transplants used for rehabilitation after ablative surgery [6,24]. Vascularization in the transition area between graft and irradiated graft bed is reduced [30]. Irradiated recipient vessels develop media fibrosis and intima dehiscence with a higher risk of thrombosis and consecutive loss of transplant [28].…”

“…Neutralizing antibodies to TGF-1 were used to improve vascularization in the transition area between graft and irradiated graft bed. Irradiation leads to impairment of microvessels in the affected skin; therefore, an experimental approach to improve wound healing and vascularization in irradiated tissue should be evaluated by staining of microvessels [30]. E-selectin has been shown to be expressed on microvessels, whereas detection of von Willebrand factor (vWF) fails [15,22].…”