Transposition flaps

Introduction

与rotation flaps的曲线外形相反,transposition flaps切缘为直线。由于transposition flap仍然属于pivotal flap,所以仍然具有以下特点:

  • 旋转就位,有一个旋转点;
  • 就位过程中在皮瓣基部形成猫耳朵。
  • 随着旋转幅度的增加,猫耳朵会变大,皮瓣有效长度会缩短,所以大多数情况下旋转幅度都不要超过90°
common-configutrations-of-tranposition-flaps.png

transposition flap可以和缺损区共用一条边,也可以仅皮瓣基部与缺损区相连而皮瓣远离缺损区,这种设计有利于借用量大且松弛区域的皮肤来修复缺损区,也有利于将皮瓣切口放置在隐蔽部位。缝合时张力最大的地方位于the closure site of the secondary defect adjacent to the base of the flap.

transposition flap的一个缺点是修复后术区形成”trap-door deformity”的可能。这种情况一般出现在数周后至3月内的时间,表现为转移后的皮瓣区域明显高出周围皮肤的畸形。其发生往往是由于皮瓣形成了一个环形或者弧形的边缘,术后瘢痕向心性收缩导致皮瓣鼓了起来,所以设计的时候使用直线状而非曲线切口以及designing the distal border of the flap with an angle instead of an arc 以防止形成户型瘢痕有助于减轻这种畸形;另外一个原因是缺损区域周围的组织没有进行足够的subdermal ubdermining。

trap-door deformity一般会随着时间慢慢改善,可以通过皮下脂肪内注射0.1 to 1 mL (depending on the size of the flap) of triamcinolone acetonide (10 mg/mL) into the area of the deformity and at the base of the flap的方式进行治疗。注射与术后四周开始,6周一次,重复2-3次。Superficial injection may cause atrophy or telangiectasias of the flap’s skin.

如果手术八个月后仍然没有改善,则需要手术进行了矫正,通过手术去除多余的皮下脂肪、瘢痕,同时可以在进行z-plasty以减轻手术后可能发生的瘢痕收缩。

Applicaiton

Classic design

经典设计的易位皮瓣包括矩形皮瓣和抛物线形皮瓣,常用于lateral and medial cheek, temple, and gelabellar处缺损的修复。小的易位皮瓣也常常用于dorsum and sidewall of the nose, chin and upper and lower lips缺损的修复。

对于小于2cm颊部缺损的修复,蒂在上或者蒂在下的皮瓣设计都可行;而对于大于3cm的颊部缺损,则需采用蒂在上的设计方式,以便于运用颊部下分、颌周甚至颈上部的松弛皮肤。

对于颊部外侧的缺损的修复,旋转皮瓣因为更能充分运用颈上部的松弛皮肤,所以较易位皮瓣更具优势。

无论如何,设计的时候尽量将缝合后的瘢痕放置在隐蔽处。

Island transposition flap

尽管运用于头颈部的易位皮瓣大多数都是随意皮瓣,但是岛状易位皮瓣却可以设计成含有轴心血管的轴型皮瓣,常用的血管蒂包括滑车上动静脉、鼻翼动脉分支等。

Facial-artery.png
Facial artery
blood supply of nose
blood supply of nose

Note flap

note-flap.png


适合小的(2cm or less)缺损的修复。

Rhombic flap

  • Limberg flap

  • 30° rhombic flap
30° rhombic flap
30° rhombic flap
  • Dufourmentel flap
Dufourmentel flap
Dufourmentel flap

Like in other transposition flaps designed to close rhombus-shaped defects, the greatest wound closure tension is at the closure site of the donor defect. Therefore, whenever possible, the donor site closure should be planned so that it is parallel to the lines of maximum extensibility (LME) and perpendicular to RSTLs.

When designing a rhombic flap, the surgeon must select the optimum flap for a given defect. The surgeon first draws two lines parallel to the LME and creates rhomboids. The four possible rhombic flaps are then conceptualized. Of the four flaps, two will have a short diagonal parallel to the LME, and one of these should be selected.6 If one flap is near a mobile facial structure, the other should be used. Design of a rhombic flap is more complex than that of most other facial skin flaps because of the exact geometry and option of placing the flap in four separate locations about the defect. I do not frequently use the rhombic flap in my practice because most micrographic defects are not rhombus shaped, and to convert the defect to a rhombus requires discarding normal tissue unnecessarily. In addition, the scar is usually more visible than when other flaps are used because approximately half of the entire length of the resulting scar does not parallel or does not fall within the RSTLs of the face. This disadvantage is more important in the area of the forehead and lips, where skin creases are more prominent, and less important in the cheek and temple, where creases are not as prominent, the skin is thinner, and the resulting scar tends to blend better with the adjacent skin.

Z-plasty

当Z-plasty用于瘢痕松解时,其延长量组要来自与皮瓣的滑行而非旋转。

Z-plasty的两臂可以不完全平行,但是中轴与两臂的长度不可差距过大。中轴的方向沿着瘢痕挛缩的方向或者需要松弛的方向,其实质是通过两个三角的易位使平行四边形中短的对角线变为长的对角线从而获得松弛的效果。所以松解量为两条对角线长度之差。

两臂与中轴夹角越大,松解量越大,但是旋转角度也会加大,形成的猫耳朵畸形也会越大,30°、45°、60°可分别获得约25%、50%和75的长度增加,一般60°获得的松解量在多数情况下已经足够

两臂越长,松解量也越大,但是形成的瘢痕也越长。所以位于面部的Z-plasty的两臂长度尽量不要超过0.5cm,当需要长的臂来获得更大的松解量时,可以使用多个Z-plasty组合,以使得每个Z-plasty的臂长不超过0.5cm。

Z-plasties-redistribute-tissue-of-SCD.png
Z-plasties redistribute tissue of standing cutaneous deformities
Z-plasties-repair-oval-skin-defect.png
Z-plasty repairs oval skin defect
Z-plasties-repairs-circular-skin-defect.png
Z-plasty repairs circular skin defect

Z-plasty除了用于松解瘢痕以外,还可用于改变瘢痕方向以及修改环形瘢痕外形以免形成”trap-door deformity”。

Bilobe flap

由于旋转幅度越大,形成的猫耳朵越大,所以常常设计成第一个lobe和缺损长轴成45°,第二个lobe和第一个lobe长轴成45°。

在皮肤较松驰弹性好的部位,第一个lobe面积可以比缺损面积稍小(25%左右),第二个lobe又比第一个lobe转移后造成的缺损稍小,但在皮肤弹性差的部位,面积差别太大可能导致关创张力增加。

其缺点在于皮瓣切口常常不能和RSTL平行,且由于切口成弧线型,所以可能出现”trap-door deformity”。

Case report

Not shown

转载请注明来源:Transposition flaps
本文链接地址:https://omssurgeon.com/525/

发表评论

您的电子邮箱地址不会被公开。