HOW WE DO IT

Bilobed Flap for Reconstruction of Small Alar Rim Defects

NATHANIEL J. JELLINEK, MD,*†‡ AND KATHARINE B. CORDOVA, MD*‡

The authors have indicated no significant interest with commercial supporters.

The bilobed flap is a well-established recon-

structive technique for many small to medium-

sized defects on the nose.1,2 Its use in large defects

involving the ala has also been demonstrated.3 This

flap is useful in areas near facial free margins such as

the lower eyelid and alar rim. It functions as a

pushing rather than pulling flap, minimizing the

risks of ectropion and ecnasion. These particular

properties, when applied on the nose, also have the

unintended potential to “bulldoze” and depress

nasal free margins in the setting of thicker, seba-

ceous skin, oversized or incorrect flap design, or

conservatively undermined flaps.2

True alar rim defects encountered after Mohs

surgery present multiple challenges: restoration of

the external nasal valve; aesthetic considerations;

and lack of an adjacent, mobile tissue reservoir on

a free margin. Traditional reconstructive options

include full-thickness skin grafts, composite grafts,

combined cartilage and skin grafts, wedge excision,

V–Y advancement flaps, turn-down hinge flaps,

and cheek-to-nose or paramedian forehead inter-

polation flaps. Second-intention healing and full-

thickness skin grafts risk alar notching associated

with wound healing and contraction, yet for

shallower alar defects away from the free margin,

they remain a viable option.4 Composite grafts are

an attractive option and provide structure and

cosmesis yet remain a challenging and less-reliable

reconstruction with frequent necrosis or partial

take. Combined cartilage and skin grafts can

mitigate these risks. Wedge excision, perhaps the

simplest option, by definition will reduce the

aperture of the nares and external nasal valve. V–Y

advancement flaps lack a mobile pedicle, and

necrosis can occur. The authors have found this

flap to be useful more superiorly on the alar lobule

and not along the rim. Any flap or graft necrosis

can result in free margin compromise, ecnasion,

and constriction of the nasal valve. Cheek-to-nose

interpolation flaps are a reliable reconstructive

option for many of these defects, albeit at the

expense of a staged surgery, cheek scar, and

potential nasolabial fold asymmetry.

The authors present a technique used in six patients

with small defects (<1 cm) on the alar rim that were

reconstructed immediately after Mohs surgery. The

bilobed flap has several attributes that make it a

reliable reconstructive option in this location: robust

perfusion, predictable pushing movement of the flap

toward the free margin, restoration of contour over

a convexity, and limiting the repair to a single

cosmetic subunit, the ala.

Technique

Sterile surgical preparation and infiltrative anes-

thesia are performed in standard fashion. It is

*Department of Dermatology, Warren Alpert Medical School, Brown University, Providence, Rhode Island; †Divisionof Dermatology, University of Massachusetts Medical School, Worcester, Massachusetts; ‡Dermatology Professionals,Inc., East Greenwich, Rhode Island

© 2013 by the American Society for Dermatologic Surgery, Inc. � Published by Wiley Periodicals, Inc. �ISSN: 1076-0512 � Dermatol Surg 2013;39:649–652 � DOI: 10.1111/dsu.12055

649

important to assess the inherent elasticity and

inelasticity of the nasal tissue and the natural

resistance of the ala to collapse before injection of

anesthesia. If anteriorly located, the defect should

be made full thickness through dermis and muscle

although not through-and-through. The flap is

designed with a muscular pedicle. If anteriorly

located, the defect should be made full thickness

through dermis and muscle although not through-

and-through. Converting the defect from partial to

full thickness minimizes flap protuberance once

healed and minimizes tension during flap move-

ment. The flap is designed with a muscular pedicle.

The flap is usually laterally based, although larger

defects and those laterally located can be medially

based. It is designed as a Zitelli-modification

bilobed flap, with total arc of rotation of approx-

imately 90º, the tertiary defect relatively perpen-

dicular to the alar rim, and the standing cone

excised as a part of the flap design—in this instance

along the alar rim.

The standing cone is excised first, then the flap is

incised and undermined in the submuscular plane,

taking care to establish and maintain the appropriate

plane of dissection. Given the small size of the

surgical field, sharp undermining using a scalpel

blade or fine-tipped gradle or tenotomy scissors is

preferred. Undermining in the caudal-most portion

of the flap in type III nasal skin is limited because of

the anatomic turn of this skin posteriorly

toward mucosa.

Hemostasis is obtained with care to avoid elec-

trosurgery on the tissue edges and walls; such

cautery creates focal areas of necrosis and pre-

disposes to more prominent and inverted suture

lines.

(A)

(B) (C)

(D) (E) (F) (G)

Figure 1. (A) Preoperative basal cell carcinoma located on the left ala bordering the alar rim. (B) Postoperative defect withbilobed flap designed in surgical marking pen. The standing cone is excised medially on the alar rim. The lobes are sizedequally and have a total arc of rotation of approximately 90º. (C) Immediate postoperative image. (D–G) Two-month follow-up photographs.

BILOBED FLAP FOR RECONSTRUCTION OF SMALL ALAR RIM DEFECTS

DERMATOLOGIC SURGERY650

The tertiary defect is sutured first. A single buried

suture is sufficient to set the flap into position and

relieve any tension on the free margin. One or two

more buried vertical mattress sutures are sufficient to

stabilize the flap in position and evert the skin edges.

All buried sutures are placed in muscle to muscle,

which may minimize the scar contraction that leads

to a trapdoor deformity.5 Superficial sutures finish

the repair and are usually removed at 5–7 days.

Postoperative antibiotics are frequently prescribed as

cotton-tipped applicators introduced intranasally

during the procedure in a nasal region that can be

prepared and scrubbed with antiseptic as can be

done with cutaneous surfaces.

A correctly designed flap will restore the natural

bulk and three-dimensional fullness of the ala and

curvature of the alar rim. The small but complex

suture lines, although initially conspicuous, tend to

fade significantly in the setting of appropriate

contour restoration, as demonstrated in the

images (Figures 1, S1, S2).

There are potential pitfalls of faulty flap design,

typically under- or oversizing of the flap. The former

will lead to contraction along the ala and ecnasion.

The latter can bulldoze the free margin, leading to

alar asymmetry and depression. Any tension along

the flap, particularly if the flap is undermined too

superficially, can lead to flap tip necrosis along the

free margin. Care must also be taken to avoid

internal valve constriction when suturing the tertiary

defect. This physiologic valve, located most closely

under the alar groove, can collapse from swelling

associated with flap movement. When the flap is

undermined and open, the surgeon must test the

ipsilateral nasal breathing of the patient, and then

repeat the test after the first key suture. If there is

constriction with this suture, a simple pexing suture

from the depth of the alar groove, fixed to the

sidewall periosteum, will open the valve and prevent

collapse.

This flap is more difficult to perform on patients

with soft, “floppy” alae, which tend to collapse

with minimal pressure and simplest in patients with

firm alar margins. We have not needed to use a

cartilage batten graft to buttress the alar free

margin during our series and would likely choose a

different reconstructive option if such a situation

arose. Similarly, if the defect is larger than 1 cm, it

is possible that the tissue movement would distort

the free margin. Given the stiff skin of the alae in

patients for whom this repair is indicated, subtle

alar base asymmetry may be appreciated; this

asymmetry has been subtle and not distressing to

patients.

The authors have found that the bilobed flap is a

reliable technique to reconstruct small alar rim

defects after Mohs surgery. This procedure addresses

all of the unique functional and aesthetic complex-

ities of the ala: maintenance of the nasal valve,

contour restoration, and reconstruction of the

free margin.

References

1. Zitelli JA. The bilobed flap for nasal reconstruction. Arch

Dermatol 1989;125:957–9.

2. Cook JL. A review of the bilobed flap’s design with particular

emphasis on the minimization of alar displacement. Dermatol

Surg 2000;26:354–62.

3. Cook JL. Reconstructive utility of the bilobed flap: lessons from

flap successes and failures. Dermatol Surg 2005;31:1024–33.

4. Collins SC, Dufresne RG Jr, Jellinek NJ. The bilobed

transposition flap for single-staged repair of large surgical defects

involving the nasal ala. Dermatol Surg 2008;34; discussion: 1379

–85.

5. Ricks M, Cook J. Extranasal applications of the bilobed flap.

Dermatol Surg 2005;31:941–8.

6. Neuhaus IM, Yu SS. Second-Intention Healing of Nasal Alar

Defects. Dermatol Surg 2012;38:697–702.

7. Teltzrow T, Arens A, Schwipper V. One-stage reconstruction of

nasal defects: evaluation of the use of modified auricular

composite grafts. Facial Plast Surg 2011;27:243–8.

8. Ewanowski CD, Cook J. Using cartilage and skin grafts

concurrently: an alternate route to repair. Dermatol Surg

2009;35:1809–17.

9. Asgari M, Odland P. Nasalis island pedicle flap in nasal ala

reconstruction. Dermatol Surg 2005;31:448–52.

10. Fader DJ, Baker SR, Johnson TM. The staged cheek-to-nose

interpolation flap for reconstruction of the nasal alar rim/lobule.

J Am Acad Dermatol 1997;37:614–19.

JELLINEK ET AL

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11. Nguyen TH. Staged cheek-to-nose and auricular interpolation

flaps. Dermatol Surg 2005;31:1034–45.

12. Cook JL. The undesirable influence of reconstructive procedures

on the symmetry of the nasolabial folds. Dermatol Surg

2005;31:1409–16.

13. Zitelli J. Commentary. Dermatol Surg 2008;34:1385–6.

Address correspondence and reprint requests to: NathanielJ. Jellinek, MD, 1672 South County Trail, Suite 101, EastGreenwich, RI 02818, or e-mail: winenut15@yahoo.com

Supplementary Material

Additional Supporting Information may be found in

the online version of this article:

Figure S1. (A–B) Preoperative photograph

demonstrating a basal cell carcinoma on the right

alar rim. (C–D) Surgical defect after two stages of

Mohs surgery, clear of tumor. (E) Laterally based

bilobed flap designed with a standing cone laterally

along the alar margin and a total arc of rotation of

approximately 90°. (F) Bilobed flap sutured into

place. (G–J) Three-month follow-up photographs

demonstrate well-camouflaged scar lines and

symmetric alar margin.

Figure S2. (A–C) Small surgical defect on the right

alar rim. (D–F) Two-month follow-up photographs

demonstrate wellcamouflaged scar lines and

preserved free alar margin.

BILOBED FLAP FOR RECONSTRUCTION OF SMALL ALAR RIM DEFECTS

DERMATOLOGIC SURGERY652