Classification and pathophysiology of skin grafts

Flaps and grafts are the 2 main surgical procedures to repair losses of skin tissue. A flap is a full-thickness portion of skin sectioned and isolated peripherally and in depth from the surrounding skin, except along one side, called the peduncle. A graft is a section of skin, of variable thickness and size, completely detached from its original site and moved to cover the zone to be repaired. According to their thickness, skin grafts are classified as split thickness (or partial) and full thickness. The former is further divided into thin, intermediate and thick. Split-thickness skin grafts usually take well, whereas a full-thickness graft only takes if it is relatively small. Grafts are also divided, on the basis of their origin, into the following: autografts, when the donor and recipient are the same individual; homografts, when the donor and recipient are different subjects belonging to the same species; hetero- or xenografts, when the donor and recipient belong to different species. Only autografts can take, whereas homo- and heterografts are rejected. Homo- and heterografts, however, can be useful in particular conditions, for example, extensive burns, because they temporarily ensure vital skin functions.

Clinical evaluation of 3 techniques to augment keratinized tissue without root coverage

BACKGROUND

The importance of keratinized tissue is a controversial subject. However, in some situations most clinicians would agree that surgical procedures to increase the amount of keratinized tissue without root coverage are indicated. In this study, 3 surgical procedures were compared in their ability to increase the width of keratinized tissue. They are: the epithelized autogenous masticatory mucosa graft (free gingival graft), autogenous predominately connective tissue graft (connective tissue graft), and acellular dermal matrix.

METHODS

Forty-five patients referred for treatment of areas with inadequate keratinized tissue were randomly assigned into 1 of 3 groups of 15 each. Each group was treated with 1 of the 3 surgical procedures to increase the width of keratinized tissue. The width of keratinized tissue pre- and postsurgery was evaluated.

RESULTS

All 3 groups started with a similar width of keratinized tissue. All of the surgical procedures resulted in a statistically significant increase in the width of keratinized tissue: free gingival graft, 4.1 mm; connective tissue graft, 3.6 mm; and acellular dermal matrix, 4.1 mm.

CONCLUSION

A statistically significant increase in the amount of keratinized tissue was obtained with all 3 surgical procedures evaluated.

Reconstruction of superficial skin cancer defects of the nose

PURPOSE

This article reviewed the results of reconstruction of surface nasal defects after removal of skin cancer.

PATIENTS AND METHODS

One hundred patients with 103 surface defects involving various locations on the nose were treated. Management included direct closure, secondary epithelization, full-thickness skin grafts, and local flaps using 1 or 2 stages.

RESULTS

Ten nasal defects were treated by direct closure, 8 defects healed by secondary epithelization, and 30 patients were treated with a full-thickness skin graft. Fifty-five defects were reconstructed with local flaps including 30 one-stage and 25 two-stage flaps.

CONCLUSION

Many options are available for reconstructing nasal defects that can lead to acceptable aesthetic results. Among the factors that need to be addressed before choosing a procedure for reconstruction of surface nasal defects resulting from skin cancer are size and location of the defect, aesthetic concerns, and the medical status of the patient.

Sign of the changing times: CPT 1999

Although CPT 1999 contains fewer changes than in past years, coders should take some time to learn them by: familiarizing themselves with the new symbols + and [symbol: see text] reviewing Appendix A for a complete list of modifiers as well as modifiers used in the ambulatory surgery center hospital outpatient setting; reviewing Appendix E for a complete list of add-on codes; reviewing Appendix F for a list of modifier-51-exempt codes; consulting the excludes note found above code 69,990 to identify procedures exempt from the use of the new operating microscope code; examining the specific codes used to identify bronchoscopic procedures; reviewing the parenthetical notes found after code 15,001, directing the coder to also assign the appropriate code for lesion excision; reviewing the changes associated with the coding of destruction of lesions understanding the changes in immunization code assignment; consulting payers for specific reimbursement guidelines.

Modification of two-flap method and framework construction for reconstruction of atypical congenital auricular deformities

A single-stage two-flap method utilizing an anteriorly based subcutaneous pedicled skin flap and a mastoid fascial flap has been applied successfully for reconstruction of lobule-type microtia. This paper presents three modifications of the two-flap method, with which atypical congenital auricular deformities necessitating both framework construction and coverage were reconstructed successfully. In middle and upper auricular deformities such as a concha-type or a scapha-type microtia, a cranially based postauricular skin flap and lower mastoid fascial flap were used. For upper auricular deformities such as microtia representing lop-ear deformity, a narrow cranially based postauricular skin flap (Grotting flap) and upper mastoid fascial flap were used. For lower auricular deformities such as total absence of the earlobe, a cranially based skin flap and lower mastoid fascial flap were utilized. In each deformity the framework was totally or partially constructed with autogenous costal, conchal, or septal cartilage or their combination according to the size or shape of the defect. Fifty-two atypical auricular deformities were corrected with the modified two-flap method and framework construction. The follow-up has ranged from 4 months to 3 years (average 18 months). No major surgical complications occurred in this series. Representative cases reconstructed with each modified method are shown. While the shape of the cartilage framework is sculptured according to the type and degree of deformity in each patient, the modified two-flap method not only adequately covers the cartilage but also preserves the fabricated framework in its natural contour and position in the diverse varieties of atypical congenital auricular deformities.

The role of the venous system in the abdominal flap of the rat

The abdominal flap of the rat has become a popular model with investigators. Recently, researchers have been reporting survival of skin flaps with varying blood supplies. We studied the viability of skin flaps on a consistent model with varied blood supply. An 8 x 9 cm flap was raised in 40 male Sprague-Dawley rats. The viability of the flaps could be studied in 25 rats. The survival of a pedicled flap based on the left inferior epigastric artery and vein was compared with that of a pedicled flap with enhanced venous drainage. The survival of a venous flap based on the paired inferior epigastric veins and the paired long thoracic veins was compared with that of an arterialized venous flap. A composite graft was used as a control for all groups. A qualitatively improved survival was found in the pedicled venous-enhanced group (66 percent) compared with the pedicled flaps (56 percent) (p > 0.05). An improved survival was found in the arterialized venous flap (57 percent) compared with the venous flap (40 percent) (p < 0.05). All flaps had improved survival compared with the composite graft (0.6 percent) (p < 0.05).

Timing, magnitude, and utility of surgical delay in the TRAM flap: I. Animal studies

Surgical delay is an effective technique, but the precise timing of the delay effect and the required extent of the delay procedure are uncertain. We endeavored to study flap survival as a function of the duration of the delay period in a rat transverse rectus abdominis myocutaneous (TRAM) flap model. Two specific delay procedures (limited and extensive) were utilized, and flap survival was assessed after delay periods of 3, 7, 10, 14, 21, and 30 days (n > or = 7, all groups). A delay of 7 days or greater resulted in statistically significant improvement in flap survival in all groups. The delay effect appeared to be maximal at 14 days, and in the extensive delay group, a 14-day delay resulted in statistically greater flap survival than a 7-day delay. Improvement in flap survival was greater when an extensive delay procedure was used. Although the model system has limitations, the rat TRAM flap appears to be a suitable model for the study of the delay phenomenon. Possible clinical correlations are addressed in part II.

Timing, magnitude, and utility of surgical delay in the TRAM flap: II. Clinical studies

Transverse rectus abdominis myocutaneous (TRAM) flap breast reconstruction was performed in 15 patients 1 week after a preliminary delay procedure. The indications for surgical delay were obesity, smoking, prior radiation therapy, a requirement for large volumes of transmidline tissue, or combinations of these risk factors. The delay procedure consisted of outpatient ligation of the deep and superficial inferior epigastric vessels. Prior to and 1 week following the delay procedure, noninvasive Doppler examinations of the superior epigastric vessels were performed. Following the delay procedure, the diameter of the superior epigastric artery increased from 1.3 +/- 0.2 to 1.8 +/- 0.3 mm (p < 0.001) and the calculated superior epigastric artery flow increased from 7.25 +/- 0.8 to 18.2 +/- 2.7 ml/min (p < 0.001). Breast reconstruction in these high-risk patients was successful without major ischemic complications, but a tendency toward unreliability of zone IV was noted. This clinical observation is consistent with the findings in our animal studies (part I). The preliminary delay procedure was well tolerated with minimal morbidity. We feel that a preliminary delay procedure is a very useful option for breast reconstruction patients at high risk for TRAM flap vascular compromise.

A classification of the island grafts

The techniques for the use of island grafts in the closure of surgical wounds after the excision of cutaneous malignancies are quite simple and yield good cosmetic results. At present, the main configurations of island grafts are described with a diverse and confusing terminology. This article presents a logical classification of the island grafts based upon the shape of the primary defect, the shape of the partial closure, and whether the graft or grafts are distant or contiguous. By use of this classification, it is possible to develop a simplified approach to wound closure for almost all cutaneous surgical defects.

Skin grafts

In this article, we have reviewed important issues regarding skin graft reconstruction of cutaneous and mucosal defects in the head and neck. Careful attention to surgical technique and immobilization of the grafts during healing lead to more successful reconstructions. Partial-thickness skin grafts lack epidermal appendages. When used for cutaneous reconstruction, they must be protected from desiccation and excessive trauma. Donor site morbidity can be reduced by protection against environmental trauma and excessive sunlight.

The classification of flaps

The history of flap surgery originated several thousands of years ago. As each era of humans learned to apply the principles of anatomy, progress was made in the coverage of difficult and complex wounds. A classification scheme is important not only to organize our thinking, but also to logically plan an operation based on reconstructive requirements. The most important factor in the safe design of flaps is a fundamental understanding of the anatomy based on the arterial supply.

[The classification of skin grafts by the coverage of the receptor area]

Classification of skin grafting in use at the Division of Plastic Surgery and Burns of the São Paulo University for 16 years is presented. It is based on the type and way of the wound coverage from which the esthetic results essentially depend. This classification takes in consideration whether the healing at the receptor site should be or not by second intention or by the limitation of the healing through the reduction of the epithelialization time.

Soft tissue reconstruction with skin grafting

Free skin grafts for soft tissue reconstruction can be classified into three types: full-thickness skin grafts, split-thickness skin grafts, and composite grafts. The indications, techniques, donor site considerations, and postoperative complications of each type of skin graft are reviewed.