The Mechanism Of Hypertrophic And Nodular Port Wine Stains And The Strategy Of Surgical Treatment

Objective: Port wine stains(PWS)is a congenital,progressive capillary malformation that frequently occurs in the head and neck.Most patients with PWS will develop hypertrophy and discrete nodularity during their adult life,which seriously affect the appearance of patients and increases the difficulty of treatment,also adversely influence personality development.For hypertrophic and nodular PWSs which are ineffective to laser or has developed obvious scars and pigment anomalies after laser therapy,which we call refractory PWSs,surgical treatment is always necessary to improve the appearance.This study included two chapters.In the first chapters,we observed the histopathological features of PWS and the expression of mTOR signal pathway in PWS to explore the potential mechanism of the development of hypertrophic and nodular PWS.In the second chapter,we retrospectively analyzed the cases of refractory PWS and introduced our experience in the surgical treatment of above refractory PWS in the head and neck.Methods:(1)We collected tissue samples of different types of PWSs in the head and neck,which were surgically removed in our department from January 2013 to January 2019.Normal skin tissues were collected for comparison.(2)HE staining was used to observe the pathological structure of different types of PWSs.(3)Immunohistochemical staining was used to observe the expression of CD31 and ?-SMA in PWSs.(4)Immunohistochemical staining and Western Blot were used to investigate the expression of mTOR?p70S6?p-p70S6?eIF4EBP1?p-eIF4EBP1 in different types of PWSs.(5)From January 2013 to January 2019,18 patients with refractory port-wine stains surgically treated in our department were reviewed.The retrospective analysis included the description of the lesions,surgical treatments and the complications and follow-up results evaluated by modified Visual Analog Scale(VAS).Results:(1)Different types of PWSs showed difference in density,diameter,and distribution of the malformed capillaries.(2)Immunohistochemical staining showed that the expression of mTOR,p-p70S6,p-eIF4EBP1 in PWS,which suggested the activation of signaling pathway.Western Blot examination showed the obviously high expression of p-p70S6 and p-eIF4EBP1 in PWS than that in normal skin,which suggested the over-activation of mTOR signaling pathway in PWS.(3)Surgical treatments included staged resection(2 cases),complete resection and repaired by local flaps(5 cases)or skin graft(5 cases),and two-staged treatments with expanded flaps(3 cases)or expanded prefabricated flap(3 cases).All of the skin graft and flaps survived well.Follow-up evaluation with Visual Analog Scale showed most of patients were satisfied with their post-operative results.Conclusions:(1)The specific histopathological features of different types of PWSs reflect the progressive development of the lesions;(2)Over-activated mTOR signaling pathway suggests that it may contribute to the development of hypertrophy and nodularity in PWS;(3)Personalized surgical treatment of refractory Port-Wine Stains can gets satisfactory results.