Paramedian Forehead Flap Nasal Reconstruction Differential Diagnoses

Updated: Dec 30, 2019
  • Author: Christopher S Crowe, MD; Chief Editor: Deepak Narayan, MD, FRCS  more...
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DDx

Diagnostic Considerations

The first steps in nasal reconstruction are to make a diagnosis and formulate a plan. The surgeon may have the opportunity to examine the patient prior to surgical excision of a skin cancer. An estimate of the tumor size and spread can be made as well as a visual determination of the wound likely to be present after excision.

In other cases, the patient presents with an acute or old nasal defect following Mohs surgery, trauma, or infection. The apparent defect does not reflect what is actually missing. In acute wounds, edema, local anesthesia, gravity, and skin tension distort the tissues, usually enlarging the defect. In old wounds, secondary healing draws the wound edges inward by contraction, decreasing the apparent defect requirements. A previous repair to patch the defect frequently distorts the original tissue loss and uses valuable donor materials or destroys blood supply to useful flaps. The apparent defect may not be the true defect.

A combination of clinical examination combined with an evaluation of medical photographs usually supplies adequate information to make a surgical plan. Preinjury photographs also can be of value. Rarely, the radiologic evaluation of large, complex defects involving bone or extensive soft tissue lesions by CT scan or MRI can be helpful. Preoperatively, the surgeon must examine the defect and in his or her mind's eye, reposition the normal to its normal position to determine the character and dimension of actual anatomic loss in 3 dimensions.

The reconstruction surgeon, while evaluating the "hole," also must understand facial aesthetics and know the "normal." Too frequently a facial defect is seen as a "hole to be filled" (an absence). The surgeon becomes absorbed in examining the crater rather than in visualizing the 3-dimensional facial feature that is absent.

Surgeons frequently are taught that a flap should be made smaller than the defect to conserve the donor site or that the flap should be made larger than the defect for safety's sake. However, if such directions are followed, too much or too little tissue is supplied to the defect, and landmark symmetry is distorted. Similarly, if a pattern of the defect is used to determine flap size, tissue is supplied inaccurately because of distortion caused by swelling or wound contraction. Even when gross bulk is brought successfully to a nasal defect, revisions may be conceived poorly and not integrated into an overall plan to restore the facial feature. The "hole" may be filled or the wound healed but a normal appearance is not restored.

Patients must be given a choice. The defect can be allowed to heal by secondary intention or a skin graft or flap can be positioned to close the wound. The number of surgical stages, donor morbidity, anesthesia requirements, and cost must be discussed. However, most patients are fastidious and wish the missing part to be restored to its original color, texture, contour, and function. Although recreating a normal nose is impossible, the reconstructive surgeon can fashion bits and pieces of other expendable tissue into a facsimile of cover, lining, and support that gives the appearance of a nose, rather than simply creating a healed or closed wound.

Remember that the face is restored by reestablishing its unit character. Frequently, the wound should be altered in size, shape, depth, and outline. This may require discarding adjacent normal tissue so that border scars lie within the joins of facial units and wound contraction is harnessed to reestablish the contour of convex units. Replace missing tissues in exact quantity so that they do not distort the borders of the defect inward or outward. No wound accurately reflects a tissue deficit. Thus, base replacement tissue on patterns of the contralateral normal or ideal.

If multiple facial units have been destroyed, often they are reconstructed in stages, occasionally employing separate grafts and flaps. Build the nose on a stable cheek and lip platform to prevent its later postoperative shift. Restore unit contour by integrating form into each stage. Use ideal donor materials for cover, lining, and support of the appropriate thickness and pliability. Soft tissue sculpturing and primary cartilage grafts create an external shape. Wound healing is controlled or harnessed by bracing the repair against contracting scar, reconstructing entire convex units, and choosing the most appropriate method of tissue transfer.