Rotation flaps

从本章开始，作者将分别对各个皮瓣进行论述。

Introduction

皮瓣具有曲线外形，与缺损区域共用一条边界，宽基底。

皮瓣曲线状的外形，使得有的时候很难将其切缘放置在与RSTL或者美容区域分界线平行的位置；但是皮瓣只有两条边界，可以尽量将其中一条边放置在隐蔽处。

与所有pivotal flaps一样，就位的时候会在末端形成一个standing cutaneous drformity（狗耳朵、猫耳朵），去除猫耳朵会对皮瓣血供产生影响，所以在皮瓣血供不是很充足的情况下，可以选择6周后再行处理，因为：

• 猫耳朵会在4-6周后发生部分改善；
• 此时无需担心皮瓣血供。

另外一个问题皮瓣边缘总的长度是小于对策切缘+缺损长度的（如下图），解决的方法有两种：一种是在切缘较长的一侧去除一个Burow triangle的皮肤，去除部分的宽度等于缺损区的宽度；另外一种方法是使用旋转加推进就位皮瓣，此时会对皮瓣产生拉伸，是皮瓣切缘变长，同时在缝合时采用二分缝合法均匀分散张力及切缘长度差异，为了有利于皮瓣推进及拉伸，可以将旋转瓣的切缘长度设计为缺损宽度的4倍。

如前所述，将旋转瓣的切缘长度设计为缺损宽度的4倍左右，有利于皮瓣的旋转推进就位，过长的皮瓣切缘长度并不会继续明显增加皮瓣可被拉伸的程度；这一点和之前提到的潜行分离类似，前行分离获得的皮瓣移动能力以及拉伸程度的增加，主要是有前面1-2cm范围的潜行分离获得的，范围过于宽泛的潜行分离反而会增加皮瓣拉伸时的张力（见Biomechanics of skin flaps中的“Surgical application of the biomechanics of skin”）。

旋转皮瓣远端的止点位置：研究发现皮瓣远端止点超过缺损区长轴90°以后，获得的皮瓣移动范围的增加是微乎其微的，所以没有必要将皮瓣远端止点的位置放在超过缺损区长轴90°的位置，虽然更长的切缘可能会有利于皮瓣的推进和拉伸，但是却并不会明显降低缝合时的张力。

pivotal falps的皮瓣长度随着旋转角度的增加将发生明显的下降，所以设计时需要考虑旋转角度导致的皮瓣可用长度的损失；对于旋转就位的皮瓣，其张力最大的位置在于皮瓣最远端，与切缘垂直，皮瓣基部不存在明显张力；对于采用旋转加推进就位的皮瓣，其张力线则从皮瓣远端位移最大的点横跨皮瓣一直延伸到基部。

皮瓣终点处的回切（back cut）通过改变pivotal flap的旋转中心可使皮瓣获得更大的旋转角度，但是会损伤皮瓣血供；皮瓣旋转推进过程中，更大的滑行范围可以通过在旋转中心处进行一定程度的潜行分离获得。

旋转皮瓣最适于修复三角形缺损区，尤其是高与底边长度比为2：1的三角缺损，为了充分利用这一优势，可以将缺损区周围去除部分正常皮肤使其形成一个高与底边长度比为2：1的三角缺损，同时将缝合位置放置在美容区分界处或皮肤皱褶内，以隐藏瘢痕。

但如果设计旋转皮瓣时其切口无法避免将与RSTL或者美容区分界线成直角相交，那么应该尽量避免使用旋转皮瓣；

Except for the dorsal nasal flap, rotation flaps are not often used in repair of nasal defects because donor site scars do not follow the boundaries separating the nasal aesthetic units. The skin of the nasal tip is inelastic, making the use of rotation flaps difficult. Small defects over the dorsum of the nose are best repaired with transposition flaps, such as a bilobe or rhombic flap. Furthermore, rotation flaps transferred from the cheek to the sidewall of the nose usually have an unacceptable result because of the necessary bridging of the flap across the nasofacial sulcus. This partially obliterates this important landmark. Similarly, rotation flaps from the cheek are inappropriate for reconstruction of lateral lip defects because the arc of the flap must extend across the melolabial fold and crease at right angles. The melolabial crease is a prominent aesthetic border, and incisions crossing it perpendicularly often create unsightly scars.

Applications

Scalp

由于头部球形的外形，使得其缺损尤其适用于旋转皮瓣的修复。由于不需要考虑瘢痕、美容区分界以及RSTL的问题，皮瓣的设计受到的限制也很少。但是由于头皮缺少延展性，所以皮瓣只能依靠旋转就位，不能产生推进滑行的效果。

相较于单个旋转皮瓣，头皮的缺损更适合采用两个、三个甚至更多旋转皮瓣来进行修复。采用两个旋转皮瓣时，可以采用如下两种方式：

• O-T repair：两个向相反方向旋转的皮瓣
• O-Z repair：两个向相同方向旋转的皮瓣

采用三个以上的皮瓣修复时，形成风车状的形状，所以有的书上又叫风车皮瓣，缝合后形成相机快门样的形状：

采用多个皮瓣进行修复时，缺损区须位于头皮中央的位置，以便于在缺损区周边形成多个旋转瓣；若缺损区位于边缘部位，常常只能使用一个大的旋转瓣进行修复，此时皮瓣的边缘长度须是缺损区直径的的四倍以上，采用回切有助于减小皮瓣缝合时的张力。但对于过大的缺损修复，皮瓣转移后遗留的secondary defects往往需要植皮修复或待其二期愈合。

头皮旋转瓣修复时形成的缺损留待6周后再行处理。

Face

旋转皮瓣特别适合位于面颊部耳前下区大于3-4cm的缺损修复：

• 有利于获取颈部后上方的皮肤用于缺损修复；
• 皮瓣切口可经耳屏前皱褶向下并转向而后发际线，有利于隐藏瘢痕；必要的时候可以继续沿着斜方肌前沿继续延长，以获得更大面积的皮肤。同时在皮瓣终点部分可以设计一个Z-plasty以此时可能形成的猫耳朵。
• 对于长期使用烟草或者缺损区曾接受放疗者，翻瓣可以在颈阔肌深面进行，以获得更多血供。

对于前额侧方以及颞部小于2cm的缺损也常常使用单个旋转瓣进行修复，皮瓣的曲线部分尽量沿着发际线走行，或者与眉毛边界平行。蒂部位于侧方，以利于获取该区松弛的皮肤。

上下唇侧方缺损可以采用旋转瓣修复，皮瓣切口位于唇面沟内以隐蔽瘢痕，皮瓣从口轮匝肌浅面翻起，血供由位于口裂外侧的皮下血管丛提供。上唇外侧的缺损，皮瓣旋转角度受限时，可以在皮瓣末端做一个back cut增加旋转幅度，这个back cut形成的瘢痕刚好位于口角处的皱褶内。皮瓣转移过程中形成的猫耳朵，需要沿着唇红缘切除，切除部分一直延伸到口角处，以隐蔽瘢痕。颏部的缺损常常采用两个相对的旋转瓣进行修复，并尽量将切口放在颏唇沟内。

本书作者主要将旋转瓣用于修复头皮以及耳前区的缺损，头颈部其他区域的应用较少，因为：

skin defects after micrographic surgery are of the size or location that would frequently necessitate curvilinear incisions that cross at right angles to aesthetic borders or to RSTLs.

In my practice, use of rotation flaps on the face is usually limited to repair of large medial and lateral cheek defects in which the incision can be placed along the inferior bony orbital rim or in the preauricular crease, both of which are aesthetic borders.

Nose: Dorsal nasal flap

• Rrecruits redundant skin from the glabella.
• can be used to repair skin defects of the nasal tip, dorsum, and sidewall
• enables the surgeon to repair caudal and midnasal defects measuring 2.5cm in diameter or less with matching adjacent tissue.

鼻背皮瓣可通过较大的面积来减少缝合时候的张力，从而避免了过度张力导致鼻尖或者鼻翼移位的情况。

flap design:

Commonly, the dorsal nasal flap is designed as a laterally based rotation flap with a back cut. The pedicle is centered in the region of the medial canthus. A curvilinear line is drawn laterally from the defect to the junction of the cheek and the nose. From this point, the line is directed superiorly, passing 0.5 cm medial to the medial canthus and extending to the superior aspect of the glabella within a glabellar crease. Because the flap is transferred primarily by pivoting, the effective length of the flap diminishes progressively as the flap rotates about its pivotal point (medial canthus). The height of the flap and thus the arc of pivotal movement must be sufficient to compensate for this shortening. Supplemental flap height is gained from the glabellar extension. The higher the extension, the greater the height of the flap, and the easier it will be to close the primary defect. From the nasofrontal angle, the glabellar extension is approximately 1.5 to 2 times the vertical height of the nasal defect. From the superior point of the glabellar extension, a line angles inferiorly toward the contralateral medial canthus, creating a 30° to 45° angle back cut. The back cut remains just superior to the level of the medial canthal tendon to protect the axial vessels from the angular artery located inferior to the tendon. In designing the flap, it is helpful to triangulate the defect by excising the standing cutaneous deformity in such a manner that the excision lays within the alar groove or above and parallel to it. Incisions for the flap should not extend below the alar groove or obliteration of the concave topography will occur between the ala and the nasal sidewall.

该皮瓣的缺点：

• nostril margin以及nasal tip由于皮瓣张力牵拉发生的上翘甚至向头部移位；
• 修复鼻侧方缺损时由于张力牵拉导致的鼻翼上抬变形；
• 如本段开头的图片所示，关闭secondary defect时，内眦部位皮肤与皮瓣的皮肤厚度极其不匹配（这也是本书作者不常使用这个皮瓣的主要原因）。

鉴于以上缺点，本书作者设计了一个”dorsal heminasal flap”

The design is such that the lateral border of the flap remains anterior to the thin skin of the medial canthal region to avoid mismatch in skin thickness. I call this design a dorsal heminasal flap. The design limits the arc of tissue movement; the modified flap can be used only for smaller (less than 2 cm) skin defects of the nasal bridge that are at least 1 cm cephalic to the nostril margin and not inferior to the tip-defining points.19 The dorsal heminasal flap does not necessarily require a glabellar incision. The lateral incision is along the junction of the nasal sidewall and dorsum and therefore recruits skin only from the nasal bridge.

Surgical technique

• all incisions are vertical to the surface of the skin with no beveling.
• The borders of the flap are incised, and the flap is then sharply undermined in the subcutaneous plane. In addition, all sides of the donor defect are undermined for a distance of at least 2 cm. An exception to this rule is when borders of the donor site are relatively fixed, such as the melolabial fold, alar-facial sulcus, or eyelid. These areas are undermined 4 or 5 mm so that wound edge eversion can occur, but without distortion of adjacent facial structures. All undermining is accomplished with sharp dissection in the subdermal plane.
• 皮瓣解剖平面：大多数在subcutaneous层面，部分可在SMAS或者颈阔肌深面。
• In harvesting of large rotation flaps, such as the cervicofacial flap, a graduated approach should be practiced.
• Patients having large rotation flaps should be checked within 24 hours after surgery to ensure that no hematoma has formed beneath the flap or at the donor site. Patients are instructed to avoid strenuous exercise for 2 weeks after surgery and are asked to avoid sun and extreme temperature exposures for at least 1 month ostoperatively. Suture removal should be accomplished in 5 to 7 days after facial flaps and 10 to 14 days after cervical and scalp flaps.
• Physical massage of the flap beginning 4 weeks postoperatively will assist in reducing postoperative edema. Surgical revision of the flap or scars should not be entertained for 9 to 12 months after the initial flap transfer.

Case report

Not shown