Prelaminating the fascial radial forearm flap by using tissue-engineered mucosa: improvement of donor and recipient sites.

In reconstructive surgery, prelamination of free flaps using split-thickness skin is an established technique to avoid the creation of a considerable defect at the donor site, for example, in the case of a radial forearm flap. For oral and maxillofacial surgery, this technique is less than optimal for the recipient site because the transferred skin is inadequate to form a lining in the oral cavity. To create mucosa-lined free flaps, prelamination using pieces of split-thickness mucosa has been performed. However, the availability of donor sites for harvesting mucosa is limited. The present study combines a tissue-engineering technique with free flap surgery to create mucosa-lined flaps with the intention of improving the tissue quality at the recipient site and decreasing donor-site morbidity. On five patients undergoing resection of squamous cell carcinoma of the oral cavity, the radial forearm flap was prelaminated with a tissue-engineered mucosa graft to reconstruct intraoral defects. Using 10 x 5 mm biopsies of healthy mucosa, keratinocytes were cultured for 12 days and seeded onto collagen membranes (4.5 x 9 cm). After 3 days, the mucosal keratinocyte collagen membrane was implanted subcutaneously at the left or right lower forearm to prelaminate the fascial radial forearm flap. One week later, resection of the squamous cell carcinoma was performed, and the free fascial radial forearm flap pre- laminated with tissue-engineered mucosa was transplanted into the defect and was microvascularly anastomosed. Resection defects up to a size of 5 x 8 cm were covered. In four patients, the graft healed without complications. In one patient, an abscess developed in the resection cavity without jeopardizing the flap. During the postoperative healing period, the membrane detached and a vulnerable pale-pink, glassy hyperproliferative wound surface was observed. This surface developed into normal-appearing healthy mucosa after 3 to 4 weeks. In the postoperative follow-up period, such functions as mouth opening and closing and speech attested to the success of the tissue-engineering technique for flap prelamination.     

Prefabricated (expander) capsule-lined transposition and advancement flaps in reconstruction of lower eyelid and oral defects: an experimental study

In six pigs with prefabricated transposition flaps and six pigs with prefabricated advancement flaps, both flap types (lined with an expander capsule) were used to reconstruct wedge excisions of the lower eyelid or defects in the cheek/oral mucosa. The capsules replaced the conjunctiva in eyelid defects and the oral mucosa in cheek defects. Histopathologic studies were performed at 5 to 7 days, 9 to 10 days, 2 weeks, 3 to 4 weeks, and 2 and 3 months after flap reconstructions. Healing was rapid and uneventful, leading to restoration of the conjunctiva/eyelid and oral mucosa between 9 days and 2 weeks. The healing of the eyelid conjunctiva was somewhat faster than of the oral mucosa. The expander capsule acted as a conjunctival/ mucosal substitute, providing a temporary physical shield, an infectious barrier, and a matrix for epithelial regeneration. All reconstructions were successful except one oral reconstruction with early flap necrosis. Flaps lined with an expander capsule could improve and facilitate clinical reconstructions in the eyelid and oral cavity.     

Osteocutaneous flap prefabrication in rats

Composite tissue defects may involve skin, mucosa, muscle, and bone together or in combinations of two or three of these tissues. Defects involving bone and skin are frequently encountered. Osteocutaneous flaps may be used to reconstruct these composite tissue defects. Sometimes, it is not possible to obtain a vascular osteocutaneous flap. Another way of producing an osteocutaneous flap that has the desired feature is prefabrication. Prefabrication of osteocutaneous flaps can be performed in two ways: (1) a vascularized osseous flap may be grafted with skin and (2) an osteocutaneous flap can be prefabricated by implanting an osseous graft into an axial island flap. There are many articles describing osteocutaneous flap prefabrication, but there is no comparison of both methods in the literature. As an experimental model for osteocutaneous flap prefabrication, rat tail bone was chosen. For the experiments, five groups were formed. Each group contained 10 rats. In the first experimental group, a vascularized osseous segment was skin grafted and an osteocutaneous flap was prefabricated. In the second experimental group, an osseous graft was implanted into an axial skin flap. To compare viability of skin and bone components of the two prefabrication groups, vascularized tail bone was elevated with overlying skin in the third group, a bone flap was elevated in the fourth group, and a skin flap that had been prefabricated by using vascular implantation was elevated in the fifth group. The authors examined five rats in each group by microangiography at the end of 4 weeks. On microangiographic analysis, all groups showed patency of vascular pedicles. There was no difference among the groups from the point of view of vascular patency and bone appearance. Bone scintigraphy was performed on the five rats in each group. On bone scintigraphic scans, the bone component of flaps was visualized in all groups except for group 5. The mean radioactivity value on the flap side was 10,362 +/- 541.1 in group 1, 10,241 +/- 1173 in group 2, 10,696 +/- 647.1 in group 3, and 10,696 +/- 647.1 in group 4. When the radioactivity values on the flap side were compared, no statistically significant difference among groups was seen, except for group 5 (p < 0.05). To evaluate bone metabolic activity, the bone component of flap and remaining last tail bone was harvested and the radioactivity of each specimen was measured with a well-type gamma counter. The parameter of percentage radioactivity in counts per minute per unit per gram of tissue was calculated. The value of the bone component of the flap side and the value of normal bone were estimated and results were compared. The mean result was 0.86 +/- 0.08 in group 1, 0.88 +/- 0.07 in group 2, 0.87 +/- 0.07 in group 3, and 0.81 +/- 0.04 in group 4. The difference among all groups was not statistically significant. Histologic examination was performed on all rats in each group and demonstrated that the bony component was viable, showing a cellular bone marrow, osteoblasts along bony trabeculae, and vascular channels in bone-containing groups. There were no significant microangiographic, histologic, or scintigraphic differences between the two experimental methods.     

Neuromucosal prelaminated flaps for reconstruction of intraoral lining defects after radical tumor resection

To reconstruct intraoral lining defects after radical tumor resection by reinnervated vascularized mucosa, eight distal radial forearm flaps and two fibula flaps were prelaminated. Prelamination was performed by exposing the vascularized fascia, onto which the split distal end of a sural graft was fixed. The fascia and the sural nerve graft were covered by device-meshed mucosa or small full-thickness mucosa pieces. These structures again were covered by a Silastic sheet as large as the future flap, and the wound was closed by the elevated skin and subcutaneous tissue. Coverage by a Silastic sheet enabled mucosal spreading on the fascia, and the final flaps were thin, mucus-producing, and larger than the originally inserted mucosa. The 10 neuromucosal prelaminated flaps were harvested together with the inserted sural nerve graft after 8 to 10 weeks. During this time, the patient underwent radiotherapy and chemotherapy. Donor sites were closed directly by the preserved skin and subcutaneous tissue. Intraoral defects were reconstructed successfully by eight neuromucosal prelaminated distal radial forearm flaps and two neuromucosal prelaminated fibula flaps. The sural nerve grafts, inserted between the fascia and the mucosa, were coaptated eight times with the lingual nerve and two times with the inferior alveolar nerve. Intended reinnervation of the mucosa could already be proved clinically and histologically in the first two patients after 11 and 9 months. Preservation of skin and subcutaneous tissue considerably lowered donor-site morbidity. Neuromucosal prelamination enables reconstruction of intraoral lining defects by reinnervated mucus-producing tissue. Reconstruction of other mucosa-lined structures by this method seems feasible. Avoidance of skin islands for reconstruction lowers donor-site morbidity.     

Reconstruction of large nasal defects with a combination of local flaps based on the aesthetic subunit principle

Herein is described a technique that uses a combination of local flaps to reconstruct large defects involving the nasal dorsum and cheek. The flaps used are a transposition flap elevated from the area adjoining the defect and bilateral cheek advancement flaps. This technique leaves all suture wounds at borders of the aesthetic subunits that have been described previously. Color and texture matches were good and symmetrical. The transposition flap can be modified according to whether the defect includes the nasal tip. After raising the cheek advancement flap, it is also possible to use a dog-ear on the nasolabial region for any alar defects. Nine patients were treated using this procedure. The technique is very reliable (no complications such as congestion and skin necrosis in our series) and is easy to perform. One patient had palpebral ectropion after the operation and underwent secondary repair. In this series, defects measuring 45 x 30 mm in maximum diameter and including the nasal dorsum, nasal tip, ala, and cheek were treated.     

Effect of radiation on skin expansion and skin flap viability in pigs

The aim of the present study was to investigate the effect of radiation treatment both on skin tissue expansion with the chronic inflation of subcutaneous expanders and on skin flap viability in surgically delayed and expanded skin in the pig. One flank in each of six pigs (initially weighing 17 +/- 1.8 kg) was randomly assigned for radiation treatment, and the contralateral flank served as a nonirradiated control. Three mirror-image, 8 x 10 cm, rectangular templates were marked on each flank; these templates were randomly assigned to the construction of a delayed skin flap (group A), a skin flap raised on expanded skin (group B), or a skin flap raised on expanded skin with a capsulectomy before flap surgery (group C). Radiation treatment was performed using sequential radiation with three fractions per week (810 cGy/fraction) for 2 weeks, with a total dose of 4,860 cGy. Twelve weeks after radiation treatment, skin expanders (8 x 10 cm) were installed subcutaneously in the locations assigned for skin expansion. Skin expansion by the inflation of subcutaneous skin expanders with saline twice weekly was started 8 weeks later and lasted for 3 weeks. Two weeks after surgical delay and the last skin expansion, 8 x 20 cm skin flaps were raised on the locations assigned for delayed skin flaps, expanded skin flaps, and expanded skin flaps with a capsulectomy. Skin flap viability was assessed 24 hours later using a fluorescein dye-staining technique. Skin expansion by the inflation of subcutaneous expanders with saline was slower (p < 0.05) in the radiated skin (39 +/- 6 ml/filling) than in the nonirradiated control skin (51 +/- 6 ml/filling). Radiation reduced the overall area of expanded skin by 23 percent (p < 0.05) compared with the control. Radiation treatment also reduced skin viability by 36 percent (p < 0.05) in the delayed skin flaps, 27 percent (p = 0.10) in the expanded skin flaps, and 36 percent (p < 0.05) in the expanded skin flaps with a capsulectomy when compared with their contralateral, nonirradiated controls. There were no significant differences in skin viability among these three types of skin flaps within the radiated and nonirradiated groups. Taken together, these observations indicate that radiation treatment reduced the effectiveness of the surgical delay procedure, the amount of subcutaneous skin expansion (by an increase in skin area), and skin flap viability. However, a capsulectomy alone did not affect the viability of skin flaps raised on expanded skin.     

Deepithelialized turnover flaps in burns

Acute and chronic burns leave behind a full-thickness defect that always requires a flap cover. Such defects are common in electrical burn injuries of the limbs. This paper deals with 35 patients with full-thickness defects following burns in whom deepithelialized turnover dermis flaps and deepithelialized turnover flaps with deep fascia have been used. This flap is an extension of Hynes's reversed dermis graft and Smahel's deepithelialized turnover flap where there is a larger area of blood supply on the deeper aspect of the dermis. If a good hinge is provided for safe blood supply, such a flap settles well in the defect, and cumbersome multistaged procedures can be avoided. If there is less fatty tissue in the area of flap used, then reversed dermis flaps are ideal because split-skin graft take is good. When there is a lot of fatty tissue on the undersurface of dermis, the fascia is also included to make it a reversed fasciocutaneous flap to augment the blood supply and for better split-skin graft survival. Advantages of the procedure and complications are elaborated.     

The prefabricated scapula flap consists of syngeneic bone, connective tissue, and a self-assembled epithelial coating.

The reconstruction of maxillary defects is a challenge in plastic surgery. The so-called prefabricated scapula flap consists of syngeneic bone covered with syngeneic dermis and is used to reconstruct maxillary defects. After placing these flaps into the oral cavity, they are reepithelialized within a short time period, raising the question of the cellular origin of the "neomucosa." We therefore obtained sequential biopsy samples of the prefabricated flap and of the flap after being placed into the oral cavity and analyzed the keratin expression profile of epithelial cells. We expected that after placing the prefabricated flap into the oral cavity, keratinocytes from adnexal structures of the dermal component of the graft would migrate onto the surface and reepithelialize the flap. Unexpectedly, reepithelialization occurred earlier. The flap had acquired a mucosa-like epithelium at the interface between the Gore-Tex coating and the dermis while still being positioned within the scapular region. The keratin expression profile of this epithelium was very similar to that of mucosal epithelium. Thus, the prefabricated scapula flap not only consisted of bone covered with connective tissue, but was also covered with epithelial cells derived from adnexal structures of the dermal graft. This seems to be the reason for the rapid restoration of an intact mucosa and the excellent outcome achieved with this surgical technique.     

Effect of capsulectomy on the hemodynamics and viability of random-pattern skin flaps raised on expanded skin in the pig

Skin flaps constructed on expanded skin usually include the underlying capsular tissue. It has been hypothesized that capsulectomy may jeopardize the viability of the expanded skin flap. The experiments reported herein were designed to test this hypothesis. Specifically, we studied the hemodynamics and viability of random-pattern skin flaps (8 X 20 cm) raised on delayed bipedicle flaps (group A) and on expanded skin pockets with capsulectomy at the time of flap elevation (group B) or with intact underlying capsular tissue (group C). Each group was randomly assigned to each flank in 16 pigs. Skin pockets were expanded by inflation of subcutaneous silicone tissue expanders with sterile saline (299 +/- 7 ml; X +/- SEM) over a period of 3 weeks. At the end of this period, the bipedicle flaps were constructed. Eight days later, random-pattern skin flaps were raised on bipedicle flaps and skin pockets. The length and area of skin flap viability, judged by the fluorescein dye test performed 1 day postoperatively, were not significantly different (p greater than 0.05) among groups A, B, and C (n = 31 to 32). There also were no significant differences (p greater than 0.05) in total skin capillary blood flow measured 1 day postoperatively (A = 2.6 +/- 0.4, B = 2.4 +/- 0.4, and C = 2.7 +/- 0.6 ml/min per flap; n = 15 to 16) and in skin viability assessed 7 days postoperatively (A = 74 +/- 2, B = 75 +/- 2, and C = 76 +/- 2 percent; n = 16) among delayed skin flaps and skin flaps raised on expanded skin pockets with or without capsulectomy. The results of this flap viability study were confirmed in 5 minipigs in a separate experiment. We conclude that capsulectomy did not have a detrimental effect on the hemodynamics and viability of random-pattern skin flaps raised on expanded skin. Furthermore, we hypothesize that skin flaps raised on expanded skin are similar to delayed skin flaps in that the skin blood flow is optimally augmented; therefore, the capsular tissue does not add significant blood supply to the overlying skin.     

Fasciocutaneous flaps: an experimental model in the pig

No experimental studies have substantiated the claim that fasciocutaneous flaps are superior to skin flaps. Using fasciocutaneous flaps designed in the pig, both flap survival and blood flow were assessed. The forelimb and hindlimb fasciocutaneous flaps survived to 8.2 +/- 0.3 cm and 7.9 +/- 0.3 cm, respectively, compared with 7.3 +/- 0.3 cm and 6.7 +/- 0.3 cm for the comparable cutaneous flaps, a statistically significant finding (p less than 0.01). Random fasciocutaneous flaps survive 12 to 18 percent longer than skin flaps. Using the radioactive microsphere technique, blood flow was measured after flap elevation, and flap survival was estimated using fluorescein. Again, a significant difference in flap survival was found, but there was no significant difference in measured blood flow. This can be explained by the relatively large interval between blood flow measurements (2 cm) compared with the observed difference in survival length (1.0 +/- 0.3 cm).     

The venous skin graft method for repairing skin defects of the fingers

A venous skin graft for the treatment of skin defects in a finger is described. This procedure involves taking a flap from the forearm together with the subcutaneous vein and anastomosing both ends of this vein to the digital artery and vein, respectively. Thirteen difficult finger wounds were resurfaced with such a venous skin graft. The sizes of the flaps ranged from 1.3 X 3.0 cm to 2 X 5 cm. The lengths of the veins taken were from 6 to 12 cm. Subcutaneous fat is thin, and there is good elasticity in the grafted flap.     

Primary closure of radial forearm flap donor defects with a bilobed flap based on the fasciocutaneous perforator of the ulnar artery

To primarily repair a series of radial forearm flap donor defects, a total of 10 bilobed flaps based on the fasciocutaneous perforator of the ulnar artery were designed at the Chang Gung Memorial Hospital in Kaohsiung in the period from January of 2002 to January of 2003. All patients were male, with ages ranging from 36 to 67 years. The forearm donor defects ranged in size from 5 x 6 cm to 8 x 8 cm, with the average defect being 47 cm. One to three sizable perforators from the ulnar artery were consistently observed in the distal forearm and were most frequently located 8 cm proximal to the pisiform, which could be used as a pivot point for the bilobed flap. The bilobed flap consisted of two lobes, one large lobe and one small lobe. With elevation and rotation of the bilobed flap, the large lobe of the flap was used to repair the radial forearm donor defect and the small lobe was used to close the resultant defect from the large lobe. All bilobed flaps survived completely, without major complications, and no skin grafting was necessary. Compared with conventional methods for reconstruction of radial forearm donor defects, such as split-thickness skin grafting, the major advantage of this technique is its ability to reconstruct the donor defect with adjacent tissue in a one-stage operation. Forearm donor-site morbidity can be minimized with earlier hand motion, and better cosmetic results can be obtained. Furthermore, because a skin graft is not used, no additional donor area is necessary. However, this flap is suitable for closure of only small or medium-size donor defects. A lengthy postoperative scar is its major disadvantage.     

Prefabricated buccal mucosa-lined flap in an animal model that could be used for vaginal reconstruction

Congenital vaginal aplasia, gynecological tumor excision, and male-to-female sex surgery are three clinical conditions in which the plastic surgeon is involved in vaginal reconstruction. Skin-lined or skin-grafted local flaps are currently used, but for many reasons, keratinized skin is not the ideal lining for such a moist cavity because it leads to dryness, desiccation, maceration of the skin, and even hair growth in the cavity. The purpose of this study was to create a subcutaneous cavity lined with mucosa in an area with a predictable blood supply. The abdominal area supplied by the deep circumflex iliac vessels was chosen. Six minipigs were used. Strips of tongue buccal mucosa formed the lining; if additional tissue was required, it was taken from the mucosal aspect of the cheek. The mucosa was expanded by using multiple stab incisions. The mucosa was sutured onto the fascia supplied by the deep circumflex iliac vessels, and the skin incision was closed over a silicone sheet to prevent adhesion to the underlying mucosa. This was left for 1 week to allow the mucosa to take. The prefabricated fascial flap was rolled over a silicone stent and was closed longitudinally to form a cylindrical shape. The flap was placed in a subcutaneous pocket in the right inguinal area. The caudal end was left open and was sutured to the surrounding skin. The silicone stent was used to keep the cavity patent and to prevent adhesions in the early stage of the healing process. Regular digital examination was performed to assess patency and contour; endoscopy allowed assessment of mucosa viability. This method of producing a mucosa-lined flap may provide a solution to the difficult problem of vaginal reconstruction.     

Reconstruction of concomitant lip and cheek through-and-through defects with combined free flap and an advancement flap from the remaining lip

Massive facial defects involving the oral sphincter are challenging to the reconstructive surgeon. This study presents the authors' approach to simultaneous reconstruction of complex defects with an advancement flap from the remaining lip and free flaps. From January of 1997 to December of 2001, 22 patients were studied following ablative oral cancer surgery. Their ages ranged from 32 to 66 years. Nineteen patients had buccal cancer, two patients had tongue cancer, and one patient had lip cancer. In all cases, the disease was advanced squamous cell carcinoma. Nine patients underwent composite resection of tumor with segmental mandibulectomy, and seven patients underwent marginal mandibulectomy. Cheek defects ranged from 15 x 12 cm to 4 x 3 cm, and intraoral defects ranged from 14 x 8 cm to 5 x 4 cm in size. One third of the lower lip was excised in nine patients, both the upper and lower lips were excised in 10 patients, and only commissure defects were excised in three patients. An advancement flap from the remaining upper lip was used for reconstruction of the oral commissure and oral sphincter. Then, the composite through-and-through defect of the cheek was reconstructed with radial forearm flaps in 13 patients, fibula osteocutaneous flaps in five patients, double flaps in three patients, and an anterolateral thigh flap in one patient. The free flap survival rate was 96 percent, and only one flap failed. With regard to complications, there were two patients with cheek hematoma, six patients with orocutaneous fistula or neck infection, and one patient with osteomyelitis of the mandible. All but one patient had adequate oral competence. All patients had an adequate oral stoma and could eat a regular or soft diet; two patients could eat only a liquid diet. For moderate lip defects, immediate reconstruction of complex defects took place using an advancement flap from the remaining lip to obtain a normal and functional oral sphincter; the free flap can be used to reconstruct through-and-through defects. This simple procedure can provide patients with a useful oral stoma and acceptable cosmesis.     

Distally based dorsal forearm fasciosubcutaneous flap

Use of a local flap is often required for the reconstruction of a skin defect on the dorsum of the hand. For this purpose, a distally based dorsal forearm fasciosubcutaneous flap based on the perforators of the posterior interosseous artery was developed. From 1997 until 2002, this flap was used to reconstruct skin defects on the dorsum of the hand in nine patients at Chonnam National University Medical School. The sizes of these flaps ranged from 10 to 14 cm in length and from 5 to 7 cm in width. The flaps survived in all patients. Marginal loss over the distal edge of the flap was noted in one patient. Three flaps that developed minimal skin-graft loss were treated successfully with a subsequent split-thickness skin graft. The long-term follow-up showed good flap durability and elasticity. The distally based dorsal forearm fasciosubcutaneous flap is a convenient and reliable alternative for reconstructing skin defects of the dorsum of the hand involving vital structure exposure. It obviates the need for more complicated and time-consuming procedures.     

Enhanced neovascularization of rat tubed pedicle flaps with low perfusion of the wound margin

To study the role of ischemia due to low perfusion as the inciter of neovascularization, caudally based 3 X 9 cm skin flaps were created on the dorsum of 50 Sprague-Dawley rats. After injection of 0.2 ml 10% fluorescein, the animals were divided into two groups. In group I (n = 25), the distal margin of the flap tip was 1 cm proximal to the border of the fluorescence (good perfusion). In group II (n = 25), the flap was cut 1 cm distally in the nonfluorescent part (poor perfusion). The tips of the tubed flaps were transferred to a wound bed on the right flank. After 10 days, the pedicles were ligated, so that flap survival depended totally on the new vascular supply from the inset area of the flap. The flaps in group I showed a significantly higher rate of necrosis of 52.4 +/- 15.1 percent versus 1.7 +/- 1.4 percent in group II (p less than 0.0001), although the flap length in group I (5.85 +/- 1.16 cm) was less than in group II (7.15 +/- 0.95 cm; p = 0.0001). A nearly three times larger amount of tissue based on the new blood supply survived in group II compared to group I. Xerograms after injection of PbO2-gelatine on day 10 showed an increased ingrowth of blood vessels in group II. After excluding the delay phenomenon as the cause for the difference in necrosis rate, it is concluded that the only possible explanation is an enhancement of neovascularization by a perfusion gradient between the wound margins.     

Reconstruction of composite through-and-through mandibular defects with a double-skin paddle fibular osteocutaneous flap

Microsurgical reconstruction of composite through-and-through defects of the oral cavity involving mucosa, bone, and external skin has often required two free flaps or double-skin paddle scapular or radial forearm flaps for successful functional and aesthetic outcomes. A safe, reliable technique using a double-skin paddle fibular osteocutaneous flap to restore the intraoral lining, mandibular bone, and external skin is described. A large elliptical or rectangular skin paddle is designed 90 degrees to the longitudinal axis of the fibula, over the junction of the middle and distal thirds of the lower leg, based only on the posterolateral septocutaneous perforators. This skin flap can be draped anteriorly and posteriorly over the fibular bone to reconstruct both the intraoral defect and the external skin defect. The area between the two skin islands of the intraoral flap and the external flap is deepithelialized and left as a dermal bridge between the two skin islands, as opposed to the creation of two separate vertical skin paddles, each based on a septocutaneous perforator. The transverse dimension of the flap can be as great as 14 cm, extending to within 1 to 2 cm of the tibial crest anteriorly and as far as the midline posteriorly, and with a length of up to 26 cm, this flap should be more than sufficient for reconstruction of most through-and-through defects. This technique has allowed the successful reconstruction of large composite defects, with missing intraoral lining, mandibular bone, and external skin, for 16 patients, with 100 percent survival of both skin islands in all cases and without the development of any orocutaneous fistulae.     

The effect of low-energy laser on skin-flap survival in the rat and porcine animal models.

Low-energy lasers are currently being used in the therapy of rheumatoid arthritis, chronic pain, muscle strain, and the promotion of wound healing in human and veterinary medicine. This study examined the effects of low-energy laser on skin-flap survival in a controlled interspecies study using the rat and porcine models. Twenty dorsal skin flaps based caudally were performed in 20 rats (10 laser-treated and 10 control flaps). The wounds were closed, and the flaps were sutured over the skin. Forty dorsal pig skin flaps based medially were raised in five pigs. The flaps were treated once per day for 10 days: 4 days preoperatively, the day of surgery, and 5 days postoperatively (30 s/cm3 per day). The average surviving rat flap surface area for the laser-treated flaps was 653 +/- 112 mm (mean +/- SD) and 580 +/- 60 mm in the control flaps, which was not significant (p greater than 0.05). In the porcine model, the average surviving area for the 20 laser-treated flaps was 949 +/- 174 mm, and the control average (n = 20) was 969 +/- 147 mm, also not significant. No beneficial effect was seen with low-energy laser preoperative and postoperative treatment of skin flaps in the rat and porcine models.     

The Tagliacozzi flap as a method of nasal and palatal reconstruction

A random flap of upper arm skin has been successfully used to reconstruct large nasal (seven patients) and palatal (three patients) defects. This method is an attractive alternative for nasal reconstruction in patients whose foreheads cannot be used. Problems of color match can be managed by subsequent resurfacing of the nose with a single-piece full-thickness graft taken from the supraclavicular area. Pedicle flaps can be transected 9 to 12 days after inset, thus shortening the immobilization period.     

Pharmacologic enhancement of rat skin flap survival with topical oleic acid

This study was instituted to investigate in a rat model the effect of topical coadministration of the penetration enhancer oleic acid (10% by volume) and RIMSO-50 (medical grade dimethyl sulfoxide, 50% by volume) on rat skin flap survival. A rectangular abdominal skin flap (2.5 x 3 cm) was surgically elevated over the left abdomen in 40 nude rats. The vein of the flap's neurovascular pedicle was occluded by placement of a microvascular clip, and the flap was resutured with 4-0 Prolene to its adjacent skin. At the end of 8 hours, the distal edge of the flap was reincised to gain access to the clips and the clips were removed. After resuturing of the flap's distal edge to its adjacent skin, the 40 flaps were randomly divided into four groups. Group 1 (control) flaps were treated with 5 g of saline, group 2 (dimethyl sulfoxide) flaps were treated with 2.7 g of dimethyl sulfoxide (50% by volume), group 3 flaps (oleic acid) were topically treated with 0.45 g of oleic acid (10% by volume), and group 4 (dimethyl sulfoxide plus oleic acid) flaps were treated with a mixture of 0.45 g of oleic acid (10% by volume) and 2.7 g of dimethyl sulfoxide (50% by volume) diluted in saline. Each flap was topically treated with 5 ml of drug-soaked gauze for 1 hour immediately after clip removal to attenuate reperfusion injury. Thereafter, drug was applied topically once daily for 4 more days. Digital photographs of each flap were then taken on day 6 and the flaps were then harvested. The percentage of skin survival in each flap was determined by computerized morphometry and planimetry. The mean surviving area of group 3 (oleic acid-treated flaps) was 23.60 +/- 4.19 percent and was statistically higher than that in group 1 (control, saline-treated flaps) at 7.20 +/- 2.56 percent. The mean surviving area of group 2 (dimethyl sulfoxide-treated flaps) at 18.00 +/- 5.23 percent and group 4 (oleic acid- and dimethyl sulfoxide-treated flaps) at 9.90 +/- 3.44 percent did not achieve statistically higher mean surviving areas than controls. A topical solution of oleic acid (10% by volume) caused a statistically significant increase in the survival of rat abdominal skin flaps relative to controls. Dimethyl sulfoxide and the two experimental drugs together did not increase the percentage of flap survival when given as a single 5-ml dose released from a surgical sponge at reperfusion for 1 hour and then daily for a total of 5 days. The reasons for the lack of response are unknown but may have included the technical difficulty of delivering an adequate dose of dimethyl sulfoxide topically and immiscibility between dimethyl sulfoxide and oleic acid. Further studies may be warranted.