Concept of Triangular, Trapezoidal and Rectangular Debulking: Application in Asian Blepharoplasty: 梯形切法





This chapter deals with the technique used by the author to facilitate the likelihood of forming a crease in a single-lidded individual: by effective removal of redundant hindering tissues (proper orientation of the removal of different layers so as to allow natural closure), minimization of scar from tension, and thorough completion of each step with lessened postoperative swelling. The steps are applicable to any form of upper blepharoplasty, whether primary or revisional, in Asians or non-Asians.


In previous publications, I discussed the concept of upper eyelid crease configurations and the essential steps required for predictable placement of a lid crease for single-eyelid patients. This method is based on accurate measurement of the central height of the upper tarsus, using it to guide placement of the incision lines for formation of the crease. As has been mentioned in previous chapters, the ideal shape of the crease tends to be either the parallel crease or the nasally joining crease. Medial upper lid fold is often present in Asians, whether they have a crease or not (as in mono-lid), and should not be considered pathologic, nor radically removed.


CONCEPT OF TRIANGULAR, TRAPEZOIDAL AND RECTANGULAR DEBULKING OF EYELID TISSUES


During a lid crease procedure by way of the external incision method, leaving behind a platform of tissues anterior to the superior tarsal border will interfere with the construction of the proposed crease. The various approaches of removing skin, skin with orbicularis, , skin with pretarsal fat, and skin with muscle and septum and preaponeurotic fat , are all attempts at creating a clear space for the formation of adhesions between fibers of the levator aponeurosis and the subcutaneous structure of the surgically created crease.


Triangular and trapezoidal debulking allow a systemic and uniform cleaning of the preaponeurotic space along the superior tarsal border .


Figure 8-1 is a schematic drawing of an Asian upper eyelid without an upper lid crease. As the drawing shows:



  • 1.

    When skin excision (< 2 mm) is carried out in conjunction with the lid crease placement, retracting the upper skin incision edge (blue dot) allows an upwardly beveled plane of dissection to proceed across the supratarsal orbicularis oculi muscle and the lower portion of the orbital septum. (In Asians who do not have a crease in the upper lid, the orbital septum is frequently fused to the levator aponeurosis at 2–4 mm above the superior tarsal border, and it can be as low as halfway down the anterior surface of the tarsus.) The septum and underlying preaponeurotic fat pads are easily identified.


  • 2.

    The septum orbitale is opened transversely across the eyelid fissure. The trapezoid of preaponeurotic tissues (viewed in this cross-section) includes occasionally a minimal amount of preaponeurotic fat, the orbital septum, supratarsal orbicularis, subcutaneous fat and overlying skin (2 mm), all of which hinge along the superior tarsal border and needed to be debulked. The anterior surface of this conceptual trapezoid consists of the skin, while the posterior portion of the trapezoid boundary is wider, and includes preaponeurotic tissues from the opened orbital septum (orbicularis oculi plus distal remnants of any septum) down to the superior tarsal border.


  • 3.

    A small strand of the pretarsal orbicularis along the inferior skin incision may be trimmed off. The trapezoidal debulking allows easy inward folding of the skin edges towards the underlying aponeurosis, facilitating surgical formation of the crease. (Collin’s electron microscopic study described insertions of distal strands of the levator aponeurosis into the septa in between pretarsal orbicularis muscle fibers rather than into any subdermal tissue along the lid crease in those eyelids that had a crease. Should this be the case, formation of a crease may be facilitated by the preceding surgical maneuver because it links the aponeurosis to the upper border of the pretarsal platform. Vigorous dissection and/or debulking of pretarsal tissues is to be avoided because they tend to lead to persistent edema and formation of multiple creases.)




FIGURE 8-1


Cross-sectional drawing of trapezoidal debulking of the preaponeurotic platform. The blue dots correspond to potential lines of skin incision. Arrows correspond to transorbicularis vector from skin to orbital septum and show possible planes of dissection through the preaponeurotic fat pads. Trapezoidal debulking of preaponeurotic tissues in Asian blepharoplasty may include all tissues (A + B is a quadrilateral) bounded by the superiorly-beveled vector and the lower (perpendicular) transorbicularis vectors along the superior tarsal border and the tissues starting from skin to the levator aponeurosis surface. Minimal or mild fat excision may be included. L, levator aponeurosis; M, Müller’s; C, conjunctiva.


If debulking is carried out without including any skin excision (single incision, green dot), the block of tissue removed resembles a triangular configuration in cross-sectional view.


If the patient has a great deal of skin redundancy, the amount of skin included for excision is increased by expanding the upper line of skin incision. The plane of dissection through the orbicularis becomes less superiorly-beveled and the trapezoidal debulking gradually turns into more of a rectangular configuration.


In the conceptual cross-section of the upper lid in Figure 8-2 , the right boundary is the skin surface and the left boundary the sheath of the orbital septum; between these two layers is the orbicularis oculi muscle. The lower edge is the superior tarsal border (STB). The pink zone denotes one example of the amount of orbicularis oculi that can be removed when only lid crease incision (green dot in Figure 8-1 ) is made without skin removal.


Apr 6, 2024 | Posted by in General Surgery | Comments Off on Concept of Triangular, Trapezoidal and Rectangular Debulking: Application in Asian Blepharoplasty: 梯形切法

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