Simplified nomenclature for compound flaps

The unique niche for compound flaps is their potential role for the repair of massive defects that demands the simultaneous restoration of multiple, missing tissue types. These complex flaps can be sorted into two major classes, and their subtypes on the basis of their means of vascularization are described. (1) Solitary vascularization, the composite flap: "multiple tissue components with a single vascular supply and dependent parts." (2) Combined flaps: (a) Siamese flaps: "multiple flap territories, dependent due to some common physical junction, yet each retaining their independent vascular supply"; (b) conjoint flaps: "multiple independent flaps, each with an independent vascular supply, but linked by a common indigenous source vessel"; and (c) sequential flaps: "multiple independent flaps, each with an independent vascular supply, and artificially linked by a microanastomosis." Many technical modifications that have improved or will improve the reliability of these flaps should not be confused as distinct flap types, but rather acknowledged as variations that can be more conveniently classified for the purposes of improved communication and research by using this basic schema as a guideline.     

Breast Reconstruction with the free TRAM or DIEP flap: patient selection,choice of flap,and outcome

Recent reports of breast reconstruction with the deep inferior epigastric perforator (DIEP) flap indicate increased fat necrosis and venous congestion as compared with the free transverse rectus abdominis muscle (TRAM) flap. Although the benefits of the DIEP flap regarding the abdominal wall are well documented, its reconstructive advantage remains uncertain. The main objective of this study was to address selection criteria for the free TRAM and DIEP flaps on the basis of patient characteristics and vascular anatomy of the flap that might minimize flap morbidity. A total of 163 free TRAM or DIEP flap breast reconstructions were performed on 135 women between 1997 and 2000. Four levels of muscle sparing related to the rectus abdominis muscle were used. The free TRAM flap was performed on 118 women, of whom 93 were unilateral and 25 were bilateral, totaling 143 flaps. The DIEP flap procedure was performed on 17 women, of whom 14 were unilateral and three were bilateral, totaling 20 flaps. Morbidities related to the 143 free TRAM flaps included return to the operating room for 11 flaps (7.7 percent), total necrosis in five flaps (3.5 percent), mild fat necrosis in 14 flaps (9.8 percent), mild venous congestion in two flaps (1.4 percent), and lower abdominal bulge in eight women (6.8 percent). Partial flap necrosis did not occur. Morbidities related to the 20 DIEP flaps included return to the operating room for three flaps (15 percent), total necrosis in one flap (5 percent), and mild fat necrosis in two flaps (10 percent). Partial flap necrosis, venous congestion, and a lower abdominal bulge were not observed. Selection of the free TRAM or DIEP flap should be made on the basis of patient weight, quantity of abdominal fat, and breast volume requirement, and on the number, caliber, and location of the perforating vessels. Occurrence of venous congestion and total flap loss in the free TRAM and DIEP flaps appears to be independent of the patient age, weight, degree of muscle sparing, and tobacco use. The occurrence of fat necrosis is related to patient weight (p < 0.001) but not related to patient age or preservation of the rectus abdominis muscle. The ability to perform a sit-up is related to patient weight (p < 0.001) and patient age (p < 0.001) but not related to preservation of the muscle or intercostal nerves. The incidence of lower abdominal bulge is reduced after DIEP flap reconstruction (p < 0.001). The DIEP flap can be an excellent option for properly selected women.     

A classification system and reconstructive algorithm for acquired vaginal defects

Although multiple flaps have been used for vaginal reconstruction, a logical approach to reconstruction of these often complex defects has not been described. The objective of this study was to establish a classification system for acquired vaginal defects and to develop a reconstructive algorithm derived from this system. This study is a retrospective review of a 7-year experience with 51 flaps in 37 consecutive vaginal reconstructions. Twenty-two partial defects and 15 circumferential defects were reconstructed in 35 patients. Average patient age was 48 years (range, 19 to 69 years). Of the 22 patients with partial vaginal defects, six involved primarily the anterior and lateral wall and 16 the posterior vaginal wall. Among the 15 patients with circumferential defects, four included only the upper two-thirds of the vagina and 11 encompassed the entire vagina. On the basis of these defects, a classification system was developed. Partial defects involving the anterior or lateral vaginal wall were classified as type IA defects and were reconstructed primarily with pedicled Singapore fasciocutaneous flaps. Partial defects involving the posterior wall were classified as type IB and were reconstructed with pedicled rectus abdominis myocutaneous flaps. Circumferential defects involving the upper two-thirds of the vagina were classified as type IIA defects and were reconstructed with a rolled rectus flap or, less commonly, sigmoid colon (one patient). Total circumferential defects, type IIB, were reconstructed largely with bilateral gracilis flaps. Six patients had major complications, including one perioperative death, one complete flap loss, one partial flap loss, and three pelvic abscesses. Three patients had minor complications that included delayed wound healing and donor-site infection. Vaginal defects can be categorized into one of four types on the basis of the location and extent of resection. Flap selection is determined on the basis of the type of defect. Using this algorithm, immediate vaginal reconstruction with pedicled regional flaps can be performed with minimal patient morbidity and few surgical complications.     

Biomechanical and viscoelastic properties of skin,SMAS, and composite flaps as they pertain to rhytidectomy

Previous studies have focused on biomechanical and viscoelastic properties of the superficial musculoaponeurotic system (SMAS) flap and the skin flap lifted in traditional rhytidectomy procedures. The authors compared these two layers with the composite rhytidectomy flap to explain their clinical observations that the composite dissection allows greater tension and lateral pull to be placed on the facial and cervical flaps, with less long-term stress-relaxation and tissue creep. Eight fresh cadavers were dissected by elevating flaps on one side of the face and neck as skin and SMAS flaps and on the other side as a standard composite rhytidectomy flap. The tissue samples were tested for breaking strength, tissue tearing force, stress-relaxation, and tissue creep. For breaking strength, uniform samples were pulled at a rate of 1 inch per minute, and the stress required to rupture the tissues was measured. Tissue tearing force was measured by attaching a 3-0 suture to the tissues and pulling at the same rate as that used for breaking strength. The force required to tear the suture out of the tissues was then measured. Stress-relaxation was assessed by tensing the uniformly sized strips of tissue to 80 percent of their breaking strength, and the amount of tissue relaxation was measured at 1-minute intervals for a total of 5 minutes. This measurement is expressed as the percentage of tissue relaxation per minute. Tissue creep was assessed by using a 3-0 suture and calibrated pressure gauge attached to the facial flaps. The constant tension applied to the flaps was 80 percent of the tissue tearing force. The distance crept was measured in millimeters after 2 and 3 minutes of constant tension. Breaking strength measurements demonstrated significantly greater breaking strength of skin and composite flaps as compared with SMAS flaps (p < 0.05). No significant difference was noted between skin and composite flaps. However, tissue tearing force demonstrated that the composite flaps were able to withstand a significantly greater force as compared with both skin and SMAS flaps (p < 0.05). Stress-relaxation analysis revealed the skin flaps to have the highest degree of stress-relaxation over each of five 1-minute intervals. In contrast, the SMAS and composite flaps demonstrated a significantly lower degree of stress-relaxation over the five 1-minute intervals (p < 0.05). There was no difference noted between the SMAS flaps and composite flaps with regard to stress-relaxation. Tissue creep correlated with the stress-relaxation data. The skin flaps demonstrated the greatest degree of tissue creep, which was significantly greater than that noted for the SMAS flaps or composite flaps (p < 0.05). Comparison of facial flaps with cervical flaps revealed that cervical skin, SMAS, and composite flaps tolerated significantly greater tissue tearing forces and demonstrated significantly greater tissue creep as compared with facial skin, SMAS, and composite flaps (p < 0.05). These biomechanical studies on facial and cervical rhytidectomy flaps indicate that the skin and composite flaps are substantially stronger than the SMAS flap, allowing significantly greater tension to be applied for repositioning of the flap and surrounding subcutaneous tissues. The authors confirmed that the SMAS layer exhibits significantly less stress-relaxation and creep as compared with the skin flap, a property that has led aesthetic surgeons to incorporate the SMAS into the face lift procedure. On the basis of the authors' findings in this study, it seems that that composite flap, although composed of both the skin and SMAS, acquires the viscoelastic properties of the SMAS layer, demonstrating significantly less stress-relaxation and tissue creep as compared with the skin flap. This finding may play a role in maintaining long-term results after rhytidectomy. In addition, it is noteworthy that the cervical flaps, despite their increased strength, demonstrate significantly greater tissue creep as compared with facial flaps, suggesting earlier relaxation of the neck as compared with the face after rhytidectomy.     

Secondary ischemia time in rodents: contrasting complete pedicle interruption with venous obstruction

The current study investigated the effect of secondary ischemic insults on ultimate flap survival. Rodent skin flaps subjected to 8 hours of secondary ischemia with total pedicle obstruction had 56 percent survival (7 of 12) compared with primary ischemic flaps of the same time, which all survived. At 10 hours of ischemia, only 42 percent of secondary ischemic flaps survived compared with 67 percent (8 of 12) of primary ischemic flaps. When the secondary ischemia was caused by venous obstruction, the results were even more striking. Ninety-two percent (11 of 12) of primary venous obstruction flaps survived 3 hours of ischemia and 75 percent (9 of 12) survived 5 hours of ischemia, while only 56 percent (7 of 12) and 8 percent (1 of 12) of flaps subjected to secondary venous obstruction survived at the same times, respectively. The explanation of these observations on the basis of tissue pathophysiologic changes will require further study. The results support the need for close monitoring of clinical flaps to ensure optimal survival.     

The expansive gluteus maximus flap

The rich vascular network of the gluteal and posterior thigh region provides for a larger range of flaps for reconstructive surgery than previously described. Facility with these flaps requires an appreciation of relevant anatomy, embryology, and anthropology. Structural changes in the gluteus maximus muscle are critical to the evolutionary advance toward an upright stance during walking. The superficial and deep segmentation of the gluteus maximus are best appreciated by phylogenic and ontogenetic study. Femoral arterial and gluteal arterial anastomotic hemodynamics are affected by the relative involution of the gluteal system in late embryogenesis. The gluteal thigh flap should include contributions from the femoral system when the cutaneous branch of the inferior gluteal artery cannot be identified. Huge sacral wounds can be closed with gluteus maximus myocutaneous flaps with maintenance of muscular function by detaching the entire origin, sliding the muscle medially, and reconstructing these attachments. By dissection between the divergent inserting fibers of the gluteus maximus, a long, superficial portion of the muscle can be raised that forms the basis of the extended gluteus maximus flap. The pedicle of the flap is at the level of the piriformis muscle and the skin paddle can be placed over the midportion of the posterior thigh. Finally, the first deep femoral perforating artery forms the basis of a posterolateral fasciae latae flap that is well suited for coverage of defects over the trochanter.     

The preexpanded radial free flap

The experimental basis for free-flap preexpansion is briefly discussed. Two cases are reported in which the ankle/heel area was resurfaced and reinnervated with a preexpanded radial flap. The size of the first flap was half the surface area of the entire forearm. Direct closure of the secondary defect was possible with a single scar and without functional deficit in both cases. The flaps were well-vascularized and consisted of the sensory distribution of one peripheral nerve division, which was anastomosed in the recipient site. This preparation proved to be finer and to have better contouring capacity and skin quality than existing alternatives. It is clear that hydraulic tissue expansion facilitates great additional use of the radial flap as well as a range of other modified free flaps when there is time available for the flap to be developed prior to transfer.     

Structural analysis of ligand binding and catalysis in chorismate lyase

Chorismate lyase (CL) removes the pyruvyl group from chorismate to provide 4-hydroxybenzoate (4HB) for the ubiquinone pathway. We previously reported the crystal structure at 1.4A resolution of the Escherichia coli CL with bound 4HB product, showing that the product is bound in an internal cavity behind two flaps. To provide a more complete basis for understanding CL's unusual ligand-binding properties and mechanism of action, we now report four crystal structures of CL mutants and inhibitor complexes, together with binding and activity measurements and molecular dynamics simulations. First, an ultrahigh resolution (1.0A) crystal structure of the CL*product complex reveals details of a substrate-sized internal cavity, also behind the flaps, near the product site. Second, a 2.4A structure of CL complexed with the inhibitor vanillate shows the flaps partly opened relative to their product-bound positions. Third, a 2.0A structure of the G90A mutant with bound product reveals the basis for tighter product binding and kinetic effects of this active site mutation. Fourth, the combination of the G90A mutation with the vanillate inhibitor produces a 1.9A structure containing two inhibitor molecules, one in the product site and the other in the adjacent cavity. The two sites are connected by a short tunnel that is partly open at each end, suggesting that CL may operate via a 2-site or tunnel mechanism.     

Comparison of three different supercharging procedures in a rat skin flap model

A significant clinical problem in reconstructive surgery is partial loss of a pedicled flap. To resolve this problem, various methods of vascular augmentation have been developed; "supercharging" is one of those techniques. A new rat flap model was developed for investigation of the supercharging procedure, and the efficacy of the arterial supercharging method was examined. The purpose of this study was to investigate how an arterial supercharging procedure could generate large flap survival areas with different supercharging positions in rats. On the basis of the vascular anatomical features of rats, a circumferential skin flap from the lower abdomen to the back, measuring 4 x 12 cm, was marked. The flap was divided along the dorsal midline. Forty rats were divided into four experimental groups, as follows: group 1 (control), flaps based only on the deep circumflex iliac artery and vein; group 2, flaps supercharged with the ipsilateral superficial inferior epigastric artery; group 3, flaps supercharged with the contralateral superficial inferior epigastric artery; group 4, flaps supercharged with the contralateral deep circumflex iliac artery. On the fourth postoperative day, the flaps were evaluated with measurements of necrosis and survival areas. Microfil (Flow Tech, Inc., Carver, Mass.) was then injected manually throughout the body, and the vascular changes produced by supercharging were angiographically evaluated. Compared with group 1 (control), the flap survival areas were significantly greater in distally supercharged flaps in groups 3 and 4 (mean flap survival, 91.2 +/- 5.2 percent and 90.5 +/- 10.6 percent, respectively; p < 0.001) and in proximally supercharged flaps in group 2 (45.9 +/- 4.1 percent, p < 0.05). Angiographic assessment of the flaps that survived completely revealed marked dilation of the choke veins among the territories and reorientation of dilated veins along the axes of the flaps. This study suggests that distal arterial supercharging (contralateral superficial inferior epigastric artery or contralateral deep circumflex iliac artery) is more effective than proximal arterial supercharging (ipsilateral superficial inferior epigastric artery) in increasing flap survival. Although the rat skin flap may not be analogous to human flaps, distal arterial supercharging might have useful therapeutic potential in increasing flap survival in clinical practice.     

Efficacy of conventional monitoring techniques in free tissue transfer: an 11-year experience in 750 consecutive cases

Conventional free flap monitoring techniques (clinical observation, hand-held Doppler ultrasonography, surface temperature probes, and pinprick testing) are proven methods for monitoring free flaps with an external component. Buried free flaps lack an external component; thus, conventional monitoring is limited to hand-held Doppler ultrasonography. Free flap success is enhanced by the rapid identification and salvage of failing flaps. The purpose of this study was to compare the salvage rate and final outcomes of buried versus nonburied flaps monitored by conventional techniques. This study is a retrospective review of 750 free flaps performed between 1986 and 1997 for reconstruction of oncologic surgical defects. There were 673 nonburied flaps and 77 buried flaps. All flaps were monitored by using conventional techniques. Both buried and nonburied flaps were used for head and neck and extremity reconstruction. Only nonburied flaps were used for trunk and breast reconstruction. Buried flap donor sites included jejunum (n = 50), fibula (n = 16), forearm (n = 8), rectus abdominis (n = 2), and temporalis fascia (n = 1). Overall flap loss for 750 free flaps was 2.3 percent. Of the 77 buried flaps, 5 flaps were lost, yielding a loss rate of 6.5 percent. The loss rate for nonburied flaps (1.8 percent) was significantly lower than for buried flaps (p = 0.02, Fisher's exact test). Fifty-seven (8.5 percent) of the nonburied flaps were reexplored for either change in monitoring status or a wound complication. Reexploration occurred between 2 and 400 hours postoperatively (mean, 95 hours). All 44 of the salvaged flaps were nonburied; these were usually reexplored early (<48 hours) for a change in the monitoring status. Flap compromise in buried flaps usually presented late (>7 days) as a wound complication (infection, fistula). None of five buried flaps were salvageable at the time of reexploration. The overall salvage rate of nonburied flaps (77 percent) was significantly higher than that of buried flaps (0 percent, p<0.001, chi-square test). Conventional monitoring of nonburied free flaps has been highly effective in this series. These techniques have contributed to rapid identification of failing flaps and subsequent salvage in most cases. As such, conventional monitoring has led to an overall free flap success rate commensurate with current standards. In contrast, conventional monitoring of buried free flaps has not been reliable. Failing buried flaps were identified late and found to be unsalvageable at reexploration. Thus, the overall free flap success rate was significantly lower for buried free flaps. To enhance earlier identification of flap compromise in buried free flaps, alternative monitoring techniques such as implantable Doppler probes or exteriorization of flap segments are recommended.     

Increased survival and vascularity of random-pattern skin flaps elevated in controlled, expanded skin

Controlled clinical tissue expansion, a new technique of providing donor tissue, results in an increase in surface area of expanded skin. The aim of the present study was to determine the effect of controlled tissue expansion on the surviving lengths of random-pattern skin flaps elevated in expanded tissue. In five pigs the surviving lengths of flaps raised in skin expanded for 5 weeks using a 250-cc rectangular Radovan-type tissue expander were compared with the survival lengths of flaps elevated in tissue in which a similar prosthesis was not expanded, bipedicle flaps delayed for 5 weeks, and control acutely raised random-pattern flaps. The expanded flaps had a mean increase in surviving length of 117 percent over control flaps, which was statistically significant. The delay flaps had an increase in survival of 73 percent over control flaps, which was also statistically significant. There was no significant difference in survival between expanded flaps and delayed flaps. Morphologic studies using radiographic techniques on one pig demonstrated increased vascularity with tissue expansion. The results of this work demonstrate that in addition to providing increased surface area with controlled expansion, flaps raised in expanded skin have a significantly augmented surviving length. The mechanism for this increased vascularity with expansion is not known at this time, but it may be due to physical forces associated with expansion acting as a stimulus for angiogenesis.     

Have we found an ideal soft-tissue flap? An experience with 672 anterolateral thigh flaps

The free anterolateral thigh flap is becoming one of the most preferred options for soft-tissue reconstruction. Between June of 1996 and August of 2000, 672 anterolateral thigh flaps were used in 660 patients at Chang Gung Memorial Hospital. Four hundred eighty-four anterolateral thigh flaps were used for head and neck region recontruction in 475 patients, 58 flaps were used for upper extremity reconstruction in 58 patients, 121 flaps were used for lower extremity reconstruction in 119 patients, and nine flaps were used for trunk reconstruction in nine patients. Of the 672 flaps used in total, a majority (439) were musculocutaneous perforator flaps. Sixty-five were septocutaneous vessel flaps. Of these 504 flaps, 350 were fasciocutaneous and 154 were cutaneous flaps. Of the remaining 168 flaps, 95 were musculocutaneous flaps, 63 were chimeric flaps, and the remaining ten were composite musculocutaneous perforator flaps with the tensor fasciae latae. Total flap failure occurred in 12 patients (1.79 percent of the flaps) and partial failure occurred in 17 patients (2.53 percent of the flaps). Of the 12 flaps that failed completely, five were reconstructed with second anterolateral thigh flaps, four with pedicled flaps, one with a free radial forearm flap, one with skin grafting, and one with primary closure. Of the 17 flaps that failed partially, three were reconstructed with anterolateral thigh flaps, one with a free radial forearm flap, five with pedicled flaps, and eight with primary suture, skin grafting, and conservative methods.In this large series, a consistent anatomy of the main pedicle of the anterolateral thigh flap was observed. In cutaneous and fasciocutaneous flaps, the skin vessels (musculocutaneous perforators or septocutaneous vessels) were found and followed until they reached the main pedicle, regardless of the anatomic position. There were only six cases in this series in which no skin vessels were identified during the harvesting of cutaneous or fasciocutaneous anterolateral thigh flaps. In 87.1 percent of the cutaneous or fasciocutaneous flaps, the skin vessels were found to be musculocutaneous perforators; in 12.9 percent, they were found as septocutaneous vessels. The anterolateral thigh flap is a reliable flap that supplies a large area of skin. This flap can be harvested irrespective of whether the skin vessels are septocutaneous or musculocutaneous. It is a versatile soft-tissue flap in which thickness and volume can be adjusted for the extent of the defect, and it can replace most soft-tissue free flaps in most clinical situations.     

Super sural neurofasciocutaneous flaps in acute traumatic heel reconstructions

Conventional reversed sural flaps have been used to cover heel defects; however, the experience of the authors indicates that the reach of these flaps falls just short of the critical area to be covered. With the limitation being the location of the flap (the middle third of the leg), the authors thought that if the flap territory were extended proximally, they would have a super flap with immense potential. Nevertheless, the critical question remained, "How far?" The massive earthquake in January of 2001 in Gujarat, India, made medical personnel pressed for time, manpower, resources, and other ancillary supports. The authors were forced to make some innovations in their management of extensive heel defects. On the basis of preexisting anatomic studies, they developed the possibility of using distally based neuroskin flaps of huge dimensions that extend well beyond the conventional confines. The versatility of this extended, reversed, neuro-fasciocutaneous flap in regard to its reliability and safety, despite its huge dimensions, is commendable. The hallmarks of this successful extended sural flap, which the authors used to cover large heel defects, were basically accurate understanding of the anatomy and the use of Doppler to map the perforators and the lesser saphenous vein for inclusion in the lie of the pedicle. The authors share their experience of five cases of difficult heel reconstructions salvaged with this flap, which made them attempt to define maximum flap dimensions that can be harvested. The authors learned that the flap can be extended proximally to include the entire upper one-third of the leg posteriorly, drastically improving its reach and size, without compromising safety. The largest flap used measured 17 x 16 cm, far more than ever reported in the literature. The flaps truly deserve the classification of "super," which is usually reserved for Ponten's flaps.     

The concept of fillet flaps: classification, indications, and analysis of their clinical value

Tissue of amputated or nonsalvageable limbs may be used for reconstruction of complex defects resulting from tumor and trauma. This is the "spare parts" concept.By definition, fillet flaps are axial-pattern flaps that can function as composite-tissue transfers. They can be used as pedicled or free flaps and are a beneficial reconstruction strategy for major defects, provided there is tissue available adjacent to these defects.From 1988 to 1999, 104 fillet flap procedures were performed on 94 patients (50 pedicled finger and toe fillets, 36 pedicled limb fillets, and 18 free microsurgical fillet flaps).Nineteen pedicled finger fillets were used for defects of the dorsum or volar aspect of the hand, and 14 digital defects and 11 defects of the forefoot were covered with pedicled fillets from adjacent toes and fingers. The average size of the defects was 23 cm2. Fourteen fingers were salvaged. Eleven ray amputations, two extended procedures for coverage of the hand, and nine forefoot amputations were prevented. In four cases, a partial or total necrosis of a fillet flap occurred (one patient with diabetic vascular disease, one with Dupuytren's contracture, and two with high-voltage electrical injuries).Thirty-six pedicled limb fillet flaps were used in 35 cases. In 12 cases, salvage of above-knee or below-knee amputated stumps was achieved with a plantar neurovascular island pedicled flap. In seven other cases, sacral, pelvic, groin, hip, abdominal wall, or lumbar defects were reconstructed with fillet-of-thigh or entire-limb fillet flaps. In five cases, defects of shoulder, head, neck, and thoracic wall were covered with upper-arm fillet flaps. In nine cases, defects of the forefoot were covered by adjacent dorsal or plantar fillet flaps. In two other cases, defects of the upper arm or the proximal forearm were reconstructed with a forearm fillet. The average size of these defects was 512 cm2. Thirteen major joints were salvaged, three stumps were lengthened, and nine foot or forefoot amputations were prevented. One partial flap necrosis occurred in a patient with a fillet-of-sole flap. In another case, wound infection required revision and above-knee amputation with removal of the flap.Nine free plantar fillet flaps were performed-five for coverage of amputation stumps and four for sacral pressure sores. Seven free forearm fillet flaps, one free flap of forearm and hand, and one forearm and distal upper-arm fillet flap were performed for defect coverage of the shoulder and neck area. The average size of these defects was 432 cm2. Four knee joints were salvaged and one above-knee stump was lengthened. No flap necrosis was observed. One patient died of acute respiratory distress syndrome 6 days after surgery.Major complications were predominantly encountered in small finger and toe fillet flaps. Overall complication rate, including wound dehiscence and secondary grafting, was 18 percent. This complication rate seems acceptable. Major complications such as flap loss, flap revision, or severe infection occurred in only 7.5 percent of cases. The majority of our cases resulted from severe trauma with infected and necrotic soft tissues, disseminated tumor disease, or ulcers in elderly, multimorbid patients.On the basis of these data, a classification was developed that facilitates multicenter comparison of procedures and their clinical success. Fillet flaps facilitate reconstruction in difficult and complex cases. The spare part concept should be integrated into each trauma algorithm to avoid additional donor-site morbidity and facilitate stump-length preservation or limb salvage.     

Leave the fat, skip the bolster: thinking outside the box in lower third nasal reconstruction

Defects of the lower third of the nose often present especially challenging reconstructive dilemmas. The surrounding skin to match is often thick, sebaceous, and sun damaged, none of which characterizes the historically ideal periauricular donor skin for grafting. The surrounding nasal skin is quite stiff, precluding very small local flaps. To avoid the "misplaced patch" appearance of most classic full-thickness grafts to this area or the depressed scar of an elliptical excision, many surgeons turn to larger local or regional flaps. These provide not only skin color and texture match but also the necessary several millimeters of subcutaneous fat necessary for proper tip aesthetics. Many defects of the lower third are small, making many surgeons reluctant to employ these larger flaps with their long scars and potential to twist or distort delicate tip or ala anatomy. The author has sought a means to transport skin and subcutaneous fat for lower third nasal defects outside of flaps. On the basis of the superiority of nasolabial fold scars and a vast positive experience in the literature utilizing skin and fat composite grafts with no bolsters, the author applied these techniques to 33 lower third nasal defects in 29 patients. Of 33 grafts varying in size from 4 mm circular to 17 mm x 16 mm and retaining 1 to 5 mm of fat, no grafts were lost. Four grafts developed a 30 percent area or less of central necrosis resulting in localized depression. Three of these four grafts were in active smokers and the fourth graft was in a former smoker. Aside from these four grafts and one with considerable excess fat early in the series, contour was good to excellent. Hypopigmentation is still common but improves with time. Easily performed composite grafts effectively carry the necessary fat for aesthetic reconstruction and do not risk long scars on the nose and twisting of the tip and ala that can result from flaps. Revisions are infrequent and extremely simple when indicated.     

Skin grafts and local flaps

Expedited healing of skin wounds is essential regardless of surgical specialty. Any skin deficiency will thwart this basic intent, and an alternative must be sought. The autogenous skin graft or local flap has long had a major role in satisfying this objective. Various forms of autogenous skin grafts are to be differentiated from local flaps, primarily on the basis of vascularization. The indications for either, their surgical anatomy, harvest techniques, and limitations, including pitfalls, need to be outlined. Skin grafts are the simplest means to restore skin integrity. If skin grafts are contraindicated, a flap may be essential. For this purpose, the "top ten" local "workhorse" flaps are briefly described in this article. Accompanying videos further elaborate the requisite surgical anatomy and harvest techniques. As a problem-solving specialty, it is incumbent upon us to first prevent, then be able to provide rapid, efficient, and efficacious healing of, any surgical wound, iatrogenic or otherwise. Skin grafts and local flaps are fundamental elements for achieving this goal when healing by primary or secondary intent is not possible. Whether one is a "reconstructive" or "aesthetic" plastic surgeon, knowledge of these basic tenets will ensure maintenance of competency.     

Presence and activity of nitric oxide synthase isoforms in ischemia-reperfusion-injured flaps

Nitric oxide is produced from the amino acid L-arginine by nitric oxide synthase, which has three known isoforms: (1) endothelial nitric oxide synthase and (2) brain nitric oxide synthase, both of which are constitutive nitric oxide synthase; and (3) inducible nitric oxide synthase. The authors' hypothesis is that after reperfusion injury, endothelial cell dysfunction leads to disruption of nitric oxide synthase-mediated nitric oxide production and that this may in part explain the deleterious effects of ischemia-reperfusion injury on tissue survival and blood reflow in flaps. An experiment was designed to study the effects of ischemia-reperfusion injury on the bioactivity of all three isoforms of nitric oxide synthase. Buttock skin flaps and latissimus dorsi myocutaneous flaps were elevated in eight pigs. Flaps on one side of the animal were randomized to receive 6 hours of arterial ischemia, whereas flaps on the other side served as controls. At 6 hours of ischemia and at 1, 4, and 18 hours after reflow, tissue biopsy specimens were obtained and were processed for both constitutive nitric oxide synthase and inducible nitric oxide synthase enzyme activity on the basis of the L-citrulline assay. In addition, specimens were processed for Western blot analysis of the three isoforms. The authors' results revealed three key findings: first, there was a statistically significant (p < 0.001) decrease in constitutive nitric oxide synthase activity of ischemia-reperfusion-injured flaps as compared with controls in both skin and muscle for all time intervals measured. Second, Western blot analyses of endothelial nitric oxide synthase and brain nitric oxide synthase showed a significant decrease in the signal intensity in ischemic and reperfused tissue as compared with controls. Third, the inducible nitric oxide synthase isoform's activity and protein remained undetectable in both tissue types for all time points measured. The authors' data demonstrated that following ischemia-reperfusion injury in the pig flap model there was a disruption of constitutive nitric oxide synthase expression and activity, which may lead to decreased nitric oxide production. The significant decrease in nitric oxide synthase activity found in the current study may partly explain the mechanism of tissue damage in flaps subjected to ischemia-reperfusion injury. Knowledge of the kinetics of nitric oxide synthase activity under conditions of ischemia-reperfusion injury has important implications for the choice and timing of delivery of therapeutic agents whose goal is to increase the bioavailability of nitric oxide in reperfused tissue.     

Pharmacologic action of isoxsuprine in cutaneous and myocutaneous flaps

The therapeutic effects of isoxsuprine on skin capillary blood flow and viability were studied in arterial buttock flaps, latissimus dorsi myocutaneous flaps, and random skin flaps in pigs. It was observed that parenteral isoxsuprine increased capillary blood flow to the skin of arterial buttock flaps and the skin and muscle of latissimus dorsi myocutaneous flaps in a dose-response manner, with a maximum vascular effect observed at 1.0 mg/kg. However, this maximum effective dose of isoxsuprine did not have any significant effect on skin viability in the cutaneous and myocutaneous flaps compared with the control. Examination of the distribution of capillary blood flow within the flaps at varying distances from the pedicle revealed that isoxsuprine did not increase capillary blood flow or perfusion distance in the distal portion of the skin of arterial buttock flaps, latissimus dorsi myocutaneous flaps, and random skin flaps. The increased capillary blood flow as a result of isoxsuprine treatment was limited only to the arterial portion of the arterial buttock flaps and latissimus dorsi flaps. Therefore, it is concluded that isoxsuprine alone is not effective in augmentation of skin viability in cutaneous and myocutaneous flaps. The pharmacologic action of isoxsuprine on the vasculature in the skin and muscle of flaps was also discussed.     

Long-term in vitro generation of amoebocytes from the Indian horseshoe crab Tachypleus gigas (Müller)

Amoebocyte is the single type of cell circulating in the horseshoe crab hemolymph, which plays a major role in the defense system of the animal. Granules present in these cells are sensitive to nanogram quantities of bacterial endotoxins, which form the basis of the Limulus amoebocyte lysate (LAL) test. Normally, amoebocytes for the production of the LAL are collected by cardiac puncture; hence, development of the in vitro culture system for amoebocytes will reduce the variability of the lysate and help to conserve the 400 million-yr-old living fossil. In the present investigation we have attempted organ culture of gill flaps that have been shown to be the source of amoebocytes. The gill flaps were cultured at 28 degrees C on a rocker platform in a modified L-15 medium supplemented with 10% v/v horseshoe crab serum. This led to the release of amoebocytes outside the gill flaps for a period of 6-8 wk with a more or less steady number of amoebocytes during the weekly harvest. No significant difference was seen in the yield of amoebocytes from male and female horseshoe crabs. Confocal laser microscopy studies revealed significant difference in the size of amoebocytes released in vitro as compared with those obtained in vivo. Thus, we have optimized the culture conditions for the long-term generation of amoebocytes in vitro from the Indian horseshoe crab Tachypleus gigas by reducing the incidence of contamination, simulating in vivo conditions for the organ culture of gill flaps, and improvising the nutritional status using the modified L-15 medium, providing the desired osmolarity and pH.     

Clinical applications of free soleus and peroneal perforator flaps

Clinical applications of two free lateral leg perforator flaps are described: a free soleus perforator flap that is based on the musculocutaneous perforator vessels from one of the three main arteries in the proximal lateral lower leg, and a free peroneal perforator flap that is based on the septocutaneous or direct skin perforator vessels from the peroneal artery in the distal and middle thirds of the lateral lower leg. The authors applied free soleus perforator flaps to 18 patients and free peroneal perforator flaps to five patients with soft-tissue defects. The recipient site was the great toe in 14 patients, the hand and fingers in five patients, the leg in two patients, and the upper arm and the jaw in one patient each. The largest soleus perforator flap was 15 x 9 cm, and the largest peroneal perforator flap was 9 x 4 cm. Vascular pedicle lengths ranged from 6.5 to 10 cm in soleus perforator flaps and from 4 to 6 cm in peroneal perforator flaps. All flaps, except for the flap in one patient in the peroneal perforator flap series, survived completely. Advantages of these flaps are that there is no need to sacrifice any main artery in the lower leg, and there is minimal morbidity at the donor site. For patients with a small to medium soft-tissue defect, these free perforator flaps are useful.