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標題: | 頭頸部顯微重建傷口癒合與無疤痕癒合機轉之研究 Study of wound healing after head and neck microvascular reconstruction and the mechanism of scarless healing |
作者: | Chen-Hsiang Kuan 官振翔 |
指導教授: | 賴鴻緒(Hong-Shiee Lai) |
共同指導教授: | 林頌然 (Sung-Jan Lin) |
關鍵字: | 頭頸顯微重建,傷口癒合,化學治療,惡性血管肉瘤,疤痕形成,微分式光熱溶解,飛梭雷射, Head and neck microvascular reconstruction,wound healing,chemotherapy,angiosarcoma,scar formation,fractional photothermolysis, |
出版年 : | 2020 |
學位: | 博士 |
摘要: | 隨著顯微手術技巧的精進與器械設備的進步,頭頸部顯微重建在過去的二十年間大大地改善臨床醫師對頭頸部複雜缺陷病患的照顧能力。顯微組織游離皮瓣有不同供體皮瓣的多樣性選擇,讓整形顯微外科醫師可以處理各種不同種類的頭頸部缺陷及傷口,更進一步對於頭頸癌病患重建外觀及功能。近年來隨著放射模組與化學治療(簡稱 化療)的快速進步,我們對於治療頭頸部癌症病患的目標也從單純延長生存曲線進階到改善生活質量,目前有許多在研究傷口癒合及疤痕形成機轉的課題,來改善臨床病人的外觀及功能。因此,探討頭頸部顯微重建的傷口癒合過程及疤痕形成機制,會是增進臨床病患照顧的重要關鍵。為此,本研究主軸分為三個部分: ㄧ,探討化學治療對頭頸部顯微重建的影響:儘管目前頭頸癌處置中的化療能明顯改善病患的存活率,然而它們對顯微重建傷口癒合的潛在有害作用尚未被明確探討。由於細胞毒性作用,我們認為化療會導致局部組織狀況變化並對傷口癒合造成負面影響,尤其是經動脈內 (intra-arterial, IA) 化療,通過精確地將化療藥物導向癌症部位,目前被廣泛用於晚期頭頸癌來控制局部病灶。本研究中,我們評估了經動脈 (IA)及經靜脈 (intravenous, IV) 術前化療對接受頭頸部顯微重建病患的影響。我們發現,IA化療組中傷口相關併發症的風險 (OR 3.30; 95%CI, 1.21-9.02; p=0.02), 動脈血管栓塞風險 (OR 4.98; 95%CI, 1.28-19.38; p=0.021), 及三十天內重返手術比率風險(OR 3.73; 95%CI, 1.10-12.64; p=0.035) 顯著相關上升。再者,我們對接合血管進行了病理學上比較研究。IA組血管組織的內膜/中層比率 (intima-media ratio) 明顯高於IV組(0.45±0.06 vs 0.23±0.03,p = 0.02),暗示化療藥物可能引起血管病變。此研究提供了間接證據顯示IA化療可能由於高濃度的細胞毒性而對局部組織造成了有害的後續影響,因此顯微重建外科醫師更需要進一步謹慎地面對傷口癒合與選擇接合血管。 二,探討頭皮惡性血管肉瘤的顯微重建與生存預後分析:在頭頸部顯微重建中,頭皮的顯微重建因為其覆蓋了顱骨,對保護功能及外觀具重要性,因此相對困難。而其中頭皮惡性血管肉瘤(scalp angiosarcoma)更因其屬於高度侵襲的惡性組織,有較高的局部復發率和較差的存活率。目前頭皮惡性血管肉瘤的標準治療為廣泛性手術切除結合輔助放射線療法。然而外科手術切除後常常存在大面積缺損伴有頭骨暴露,後續顯微重建上深具挑戰。由於臨床上頭皮惡性血管肉瘤發生稀少,極少相關之臨床研究文獻,對於手術切除及後續重建及傷口癒合更甚少探討。我們的研究針對頭皮惡性血管肉瘤的外科治療,從1996年至2017年找出41例診斷為頭皮惡性血管肉瘤之患者,研究其廣泛性切除術 (通常伴隨顯微游離皮瓣重建)及手術病理切緣對生存率之影響。我們發現在30例未轉移之局部病灶患者中,病理切緣陰性的廣泛切除可提高生存率。在單變項分析,無論是側面或深部的陽性切緣都是局部復發存活 (Recurrence free survival, RFS),局部區域控制 (locoregional control, LRC) 及整體存活 (overall survival, OS) 顯著的差預後因素 (p <0.05)。在多變項分析,陽性切緣之風險比Hazard Ratio (HR): RFS (HR 4.29, 95% CI, 1.71-10.75, p=0.002), LRC (HR 6.35, 95% CI, 2.19-18.37, p=0.001), OS (HR 4.73, 95% CI, 1.71-13.07, p=0.003) 顯著上升。我們並探討顯微重建對頭皮傷口癒合的影響。 三,探討飛梭雷射處置之無疤癒合機轉:由於在頭頸部顯微重建後,手術後疤痕形成會明顯影響患者外觀及自尊心。臨床改善疤痕方面,商用飛梭雷射透過微模組之微分性光熱溶解 (micropatterned fractional photothermolysis),啟動良好的傷口癒合過程進而刺激膠原蛋白新生。然而目前關於微分性光熱溶解如何達到快速癒合及其近無疤癒合的認識卻很少。我們運用小鼠皮膚動物模式,透過調整微分性光熱溶解的雷射微光束之單位能量及密度來對皮膚造成定性定量之可控制熱傷害,我們發現與燒傷引起的嚴重疤痕形成相比,成年小鼠在接受微分性光熱溶解後可以近無疤癒合。並且,有熱傷害的“閥值”來決定產生疤痕與否,在閥值以下可以進行無疤癒合,在閥值以上則是會進行疤痕性癒合。我們的假說是: 對於傷口癒合,哺乳類成年皮膚仍保有可無疤癒合的能力,並且存在一閥值門檻來決定引發無疤癒合或疤痕性癒合,而這樣的轉換機轉是透過局部微環境的發炎程度來決定。在此疤痕形成機轉研究中,我們研究皮膚接受微分性光熱溶解後傷口癒合背後的細胞動態過程,我們詳細地探討了微分性光熱溶解後組織重塑的過程,並以多光子顯微鏡進行活體組織造影。我們發現微熱溶解區 (microthermal zone) 巨觀上雖然是近無疤癒合,但微觀組織學上呈現融化之變性膠原蛋白。藉由BrdU及cyclin D1之標定,微熱溶解區傷口在二十四小時內迅速完成表皮癒合,並且上皮細胞開始迅速增生。進一步以多光子顯微鏡及倍頻訊號固定單點觀察追蹤微熱溶解區之動態組織重塑,我們發現新生膠原蛋白的沉積在受傷後第五週左右才啟動,並且持續到近六個月才恢復原本組織架構。與燒傷後快速形成之廣泛疤痕相較,微分性光熱溶解之膠原蛋白沉積明顯延遲。為了探討膠原蛋白形成之來源,我們發現在微熱溶解區中幾乎沒有成肌纖維母細胞活化也未形成肉芽組織。我們以譜系追蹤標定,發現纖維細胞在八週左右移動進入微熱溶解區,和以肌纖維母細胞為主之傳統疤痕形成機轉不同。此外,微分性光熱溶解伴隨著短暫升起的低程度發炎反應,透過比較核糖核酸序列轉錄體 (RNA sequencing transcriptome) ,我們證實了微分性光熱溶解有上皮細胞的早期遷移和低炎症特性。總結來說,探討微分性光熱溶解的動態傷口癒合過程,發現有許多與胎兒無疤癒合之相似處,這些結果將可以幫助我們進一步了解無疤癒合背後的細胞機轉,提供我們概念性上發展新的策略來幫助臨床病人加速癒合,改善疤痕反應,增加美觀及減少功能損失。 Over the past two decades, head and neck microvascular reconstruction has drastically improved the ability to manage patients with complicated defects in the affected regions and provided aesthetic and functional restoration. Meanwhile, as radiotherapy modality and chemotherapeutic reagents have greatly advanced, the paradigm of the treatment goal has shifted from survival to an improvement of a patient’s quality of life. Hence, more issues are now focused on the optimization of wound healing and achievement of normal outer appearance by secondary refinements. Thus, understanding the current challenges of wound healing and mechanisms of scar formation in the head and neck microvascular reconstruction has become an important key to improving clinical patient care. Here, we aimed to focus on three major topics: I. The impacts of chemotherapy on wound healing after head and neck microvascular reconstruction: Chemoradiation has changed the therapeutic landscape and demonstrated improved survival rates in recent years. However, their potentially detrimental role in head and neck microvascular reconstructive outcomes has not been well defined. Because of the well-known cytotoxicity effects and negative influence on wound healing from chemoradiation, we assume the local tissue condition resulting from chemotherapy regimens will pose a tough challenge for microvascular reconstruction. In particular, intra-arterial (IA) chemotherapy, which improves locoregional control by precisely directing chemotherapeutic agents towards the cancer site, is widely used for advanced head and neck cancers. First, we investigated the clinical outcomes of microvascular reconstruction in patients with prior IA and intravenous (IV) chemotherapy. We found that prior IA chemotherapy was associated with a significantly higher occurrence of wound-related complications (Odds ratio, [OR] 3.30, p=0.02), arterial thrombosis (OR 4.98, p=0.021), and an increase incidence of revision surgery within one month (OR 3.73, p=0.035). Based on histology, IA group vessels showed a higher intima/media ratio than the IV group (0.45±0.06 versus 0.23±0.03, p=0.02), indicating possible vasculopathy. The results provided evidence that IA chemotherapy may have caused subsequent deleterious effects on local tissue due to the high concentration of cytotoxic chemotherapeutic agents. II. Microvascular reconstruction and survival outcome in scalp angiosarcoma: Microvascular reconstruction for scalp, in particular, is important since the scalp covers the calvarium and is essential for both cosmesis and protection. Scalp angiosarcomas (AS) are aggressive soft tissue sarcomas and present great challenges for surgeons due to the frequently huge post-resection defects. Generally, a multimodality management regimen combining surgical wide excision and adjuvant radiotherapy is widely adopted as the standard treatment. However, due to the rarity of the disease, limited data on the clinical outcome of scalp AS are available. Here, we focused on the surgical management of scalp AS and hypothesized that wide excision, with subsequent microvascular reconstruction, would improve survival rates. We identified 41 patients with scalp AS from 1996-2017. In patients with localized disease, univariate analysis showed that wide excision with negative margins, either lateral-side or deep-side, improved survival rates. On multivariate analysis, positive margins emerged as adverse prognostic factors for RFS (Hazard Ratio (HR) 4.29, p=0.002), LRC (HR 6.35, p=0.001), and OS (HR 4.73, p=0.003). Together, we highlighted the importance of attaining negative surgical margins and subsequent microvascular reconstruction. III. Mechanism of scarless healing of fractional photothermolysis (FP) Postoperative scar formation greatly affects the self-esteem of patients, especially those who undergo microvascular reconstruction with head and neck deformity. Clinically, FP forms micropatterns of thermal injury and is widely used to improve scar by initiating a new wound healing process and stimulating collagen neogenesis. However, little is known about how FP achieves rapid scarless healing. We found that, compared with extensive scar formation induced by burns, adult mice healed scarlessly when the injury was fractionated into microzones of injury. Here, we detailed the tissue remodeling process after fractional photothermolysis histologically and examined it under transmission electron microscopy. Microscopically, the microthermal zone (MTZ) appeared as area with melted denatured collagen. Meanwhile, the MTZ re-epithelized within twenty-four hours. With multiphoton microscopy in vivo imaging, we traced the MTZ dynamic healing and found the deposition of new collagen was not initated until five weeks post injury and the collagen network was not fully restored until the 6th months. Furthermore, few myofibroblasts were activated and no granulation tissue formed. Lineage tracing revealed that collagen-secreting fibroblasts were recruited to the MTZ until the 8th week. Meanwhile, FP is characterized with transient low inflammation response. Collectively, our study indicated that the healing of FP shared many similarities with fetal scarless healing. Understanding how FP heals on the scale of microthermal injury can conceptually help us develop strategies to improve scar in clinical patients. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/15304 |
DOI: | 10.6342/NTU202001366 |
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顯示於系所單位: | 臨床醫學研究所 |
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