April 2020 HSC Section 4 - Plastic and Reconstructive Problems

Plastic and Reconstructive Surgery • July 2019

and flap transfer techniques have been published but describe small patient numbers with limited follow-up. 5–9 We present our 17-year experience in 47 patients using a folded radial forearm flap for full-thickness total/subtotal nasal, central nasal and heminasal defects, or a circumferential flap for inner lining defects only. PATIENTS AND METHODS Fifty microvascular radial forearm flaps were used in 47 patients between 2000 and 2017. There were 32 female and 15 male patients. Patient age ranged from 10 to 78 years (average, 42 years). Causes and types of nasal defects are summarized in Tables 1 and 2. Nineteen patients (40 percent) had been pre- viously irradiated and 15 patients (32 percent) had undergone prior attempts at repair with a radial forearm ( n = 2), parascapular ( n = 1), fibular ( n = 2), latissimus ( n = 3), anterolateral thigh ( n = 1), or forehead ( n = 16) flap. The first- stage microvascular nasal reconstruction was per- formed by two of the authors (A.H.S. and F.J.M.). Subsequent procedures were performed by the second author (F.J.M.). Preoperative Planning Preoperatively, measurements determine the available size and thickness of the forearm, esti- mate the length of the forearm vascular pedicle, and determine the distance from the defect to the recipient vessels. Because the preferred anasto- moses are performed end-to-side to the external

carotid artery and internal jugular vein, the dis- tance between the nasal defect and a point 3 cm below the angle of the mandible is compared with the available forearm pedicle length. If the pedi- cle is too short (rare), a radial artery graft from the opposite forearm is planned. To restore vault, floor, and columellar lining for full-thickness total/subtotal defects, the flap is harvested from either forearm and transferred to the opposite neck to anastomose the vascular ped- icle to the contralateral neck vessels. The flap is folded in two planes, positioning the radial aspect of the skin over the dorsal graft, and placing the vascular pedicle over the mid dorsum, away from the tip where the ulnar skin is to be folded inward to line the vault and columella. Less often, the flap may have to be anasto- mosed to the ipsilateral neck vessels because of donor forearm injury, damaged contralateral neck vessel, or thickness of the forearm fat that precludes a safe complex folding in two dimen- sions. For an ipsilateral anastomosis, the flap is reversed, placing the pedicle and the radial skin under the dorsal graft to restore vault and floor lining, and folding the ulnar skin in a single plane over the dorsal graft for temporary cover. Lining for a columella is not initially restored. Internal circumferential flaps, used to replace lining only, may be anastomosed to either side of the neck. Flap Design For total/subtotal nasal reconstruction, a trapezoid flap is sited over the distal radial artery. The radial border of the flap is 2 cm lateral to the course of the artery. The width of the radial bor- der is 6 cm. The ulnar border of the flap is 8 cm wide. The length of the flap, which corresponds to the height of the trapezoid, is 8 to 9 cm. A 2 × 6-cm skin extension can be added to the proxi- mal ulnar side of the flap to resurface an accom- panying nasal floor deficiency. When insetting, the extension is positioned just distal to the site of folding along the future nostril rim. Lining-only defects are resurfaced with a 2.5 × 8- to 10-cm rectangular flap designed longitu- dinally over the radial artery. A 1.5-cm extension can be added to either side of the flap, as a senti- nel flap, and sutured within the buccal sulcus for postoperative monitoring. Surgical Technique Both surgeons work simultaneously to harvest the radial forearm flap, recreate the nasal defect, and obtain cartilage grafts. A proximal longitudi- nal forearm incision exposes both the superficial

Table 1. Cause and Indications Cause

No. of Patients

Carcinoma  Intranasal  Cutaneous Cocaine injury

16

4

12

Trauma

4 4 3 3 1

Congenital

Wegener disease Rhinoplasty necrosis Infection (noma)

Table 2. Nasal Defect Defect

No. of Patients

Total

5

Subtotal Heminasal Distal nasal Inner lining

23

2 6 5 4

 Circumferential

 Isolated

144