In-Service Exam
Skin Grafts - Fat - Cartilage Grafts - 2002





Which of the following soft-tissue fillers is derived from hyaluronic acid?

(A) Dermalogen
(B) Fascian
(C) Isolagen
(D) Restylane
(E) Zyderm
The correct response is Option D.

Restylane is a cross-linked, stabilized, third-generation hyaluronic acid gel that is a byproduct of processed bacteria. Hyalform gel is also comprised of hyaluronic acid, but is culled instead from an animal-based compound. When used as soft-tissue filler, these substances provide low antigenicity, soft texture, and durability. However, they have not yet been approved for use in the United States.

Dermalogen (dermis) and Fascian (fascia lata) are homologous sources of injectable filler derived from human tissue. Isolagen is an autologous agent derived from human skin cells that consists of cultured fibroblast media with an extracellular matrix. Zyderm is an injectable filling agent derived from bovine collagen.

References
1. Apesos J, Muntzing MG. Autologen. Clin Plast Surg. 2000;27:507-513.
2. Cheng JT, Perkins SW, Hamilton MM. Collagen and injectable fillers. Otolaryngol Clin North Am. 2002;35:73-85.
3. Grossman KI. Facial scars. Clin Plast Surg. 2000;27:627-642.

Which of the following is the most common unfavorable result of lip augmentation with acellular dermal homograft?

(A) Exposure
(B) Hematoma
(C) Infection
(D) Rejection
(E) Resorption

The correct response is Option E.

Graft resorption has been reported as the most common complication of lip augmentation with acellular dermal homograft (Alloderm), a product derived from human cadaveric skin for use in soft-tissue augmentation. During harvest of the graft, the dermal and extracellular matrices are left intact, while the immunogenic components are removed. Alloderm can be used for skin grafting of burn wounds, nasal reconstruction, replacement of gingiva, and facial augmentation. Good results have been reported with the use of Alloderm for lip augmentation. Complications other than resorption, such as graft exposure or rejection, hematoma, and infection, have been reported to be minimal.

References
1. Rohrich RJ, Reagan BJ, Adams WP Jr, et al. Early results of vermilion lip augmentation using acellular allogenic dermis: an adjunct in facial rejuvenation. Plast Reconstr Surg. 2000;105:409.
2. Tobin HA, Karas ND. Lip augmentation using an alloderm graft. J Oral Maxillofac Surg. 1998;56:722-727.

Injection of autologous fat at which of the following sites is associated with increased risk for fat embolism and subsequent blindness and/or central nervous system damage?

(A) Forehead
(B) Glabella
(C) Lateral orbit
(D) Nasolabial fold
(E) Tear trough

The correct response is Option B.

Although injection of autologous fat during aesthetic and reconstructive procedures is typically a safe procedure, adverse effects, such as fat embolism and central nervous system damage, have been reported. The surgeon should be particularly cautious when injecting fat into the glabellar region, as the ophthalmic artery, which connects directly to the glabellar vasculature, can be inadvertently divided. Methods to help minimize complications of fat injection include the use of blunt tip large bore cannulas, as well as retrograde injection techniques.

Although the risk for injury exists with injection into the periorbital and nasal regions, it is less than that seen with injection into the glabellar region. Injection into the region of the frontalis muscle (ie, forehead), or into crow's feet in the region of the lateral orbit, a tear trough, or the nasolabial fold is associated with a lower risk for fat embolism than injection into the glabellar region.

References
1. Feinendegen DL, Baumgartner RW, Vuadens P, et al. Autologous fat injection for soft tissue augmentation in the face: a safe procedure? Aesthetic Plast Surg. 1998;22:163-167.
2. Lee DH, Yang YN, Kim JC, et al. Sudden unilateral visual loss and brain infarction after autologous fat injection into nasolabial groove. Br J Ophthalmol. 1996;80:1026-1027.
3. Teimourian B. Blindness following fat injections (letter). Plast Reconstr Surg. 1988;82:361.

What is the lowest bacterial count that will result in infection of cultured epithelial autografts?

(A) 101
(B) 102
(C) 103
(D) 104
(E) 105

The correct response is Option B.

Tissue-cultured grafts such as cultured epithelial autografts have a low degree of resistance to infection. They will tolerate bacterial counts to a maximum of 102 to 103 cm3 before developing an infection, as compared with 104 to 105 cm3 for split-thickness skin grafts.

Tissue-cultured skin grafts are expensive and fragile. Well vascularized beds are required for successful graft survival.

References
1. Green H. Cultured cells for the treatment of disease. Sci Am. 1991;265:96-102.
2. Kumagai N, Nishina H, Tanabe H, et al. Clinical application of autologous cultured epithelia for the treatment of burn wounds and burn scars. Plast Reconstr Surg. 1988;82:99-110.

In a patient undergoing lip enhancement using sheet acellular dermal homograft, which of the following is the correct anatomic placement of the graft?

(A) Subdermal placement along the white roll of the lip
(B) Subdermal placement along the wet/dry vermilion border of the lip
(C) Submucosal placement along the white roll of the lip
(D) Submucosal placement along the wet/dry vermilion border of the lip
(E) Intramuscular placement

The correct response is Option D.

Following adequate anesthesia, sheet acellular dermal homograft (Alloderm) should be placed submucosally along the wet/dry vermilion border of the lip. In order to effectively enhance the lips, the surgeon should first place bilateral incisions approximately 0.5 cm from the commissure on both the upper and lower lips; this will allow for tunneling of the Alloderm along this border. After the Alloderm is placed, the lip is stretched, allowing proper sealing of the graft. The ends should then be tapered and placed in a submucosal pocket near the commissure. Suturing is associated with the development of dynamic lip deformities and thus should not be performed.

Because subdermal placement is too superficial, the patient will be predisposed to the development of contour irregularities if the implants are placed at this level. Submucosal placement of the Alloderm along the white roll will result in unnatural lip aesthetics. Alloderm should not be placed within the muscle.

References
1. Rohrich RJ, Reagan BJ, Adams WP Jr, et al. Early results of vermilion lip augmentation using acellular allogenic dermis: an adjunct in facial rejuvenation. Plast Reconstr Surg. 2000;105:409.
2. Tobin HA, Karas ND. Lip augmentation using an alloderm graft. J Oral Maxillofac Surg. 1998;56:722-727.