Abdominal Wall Allograft: Preclinical Biomechanical Investigation of a Novel Reconstructive Adjunct.

INTRODUCTION: Acellular dermal matrices have revolutionized abdominal wall reconstruction; however, device failure and hernia recurrence remain significant problems. Fascia grafts are a reconstructive adjunct with increased tensile strength compared with acellular dermal matrices; however, clinical use is limited by insufficient donor material and donor site morbidity. To this end, we investigate the biomechanical properties of human abdominal wall allografts (AWAs) consisting of the anterior rectus sheath from xiphoid to pubis. METHODS: After cadaveric procurement of 6 human AWAs, the tissue was divided horizontally and a matched-sample study was performed with specimens randomized to 2 groups: fresh, unprocessed versus processed with gamma irradiation and decellularization. Specimens were evaluated for physical properties, DNA content, tensile strength, and electron microscopy. RESULTS: All AWA donors were male, with a mean age of 55.2 years (range, 35-74 years). Procured AWAs had a mean length of 21.70 ± 1.8 cm, width of 14.30 ± 1.32 cm, and area of 318.50 cm, and processing resulted in a 98.3% reduction in DNA content. Ultimate tensile strength was significantly increased after tissue processing, and after subcutaneous implantation, processed AWA demonstrated 4-fold increased tensile strength compared with unprocessed AWAs. CONCLUSIONS: Acellular AWAs represent a novel reconstructive adjunct for abdominal wall reconstruction with the potential of replacing "like with like" without additional donor site morbidity or antigenicity.

Evaluation of Sidestream Darkfield Microscopy for Real-Time Imaging Acellular Dermal Matrix Revascularization.

BACKGROUND: Acellular dermal matrices (ADMs) serve as a regenerative framework for host cell integration and collagen deposition to augment the soft tissue envelope in ADM-assisted breast reconstruction-a process dependent on vascular ingrowth. To date noninvasive intra-operative imaging techniques have been inadequate to evaluate the revascularization of ADM. METHODS: We investigated the safety, feasibility, and efficacy of sidestream darkfield (SDF) microscopy to assess the status of ADM microvascular architecture in 8 patients at the time of tissue expander to permanent implant exchange during 2-stage ADM-assisted breast reconstruction. The SDF microscopy is a handheld device, which can be used intraoperatively for the real-time assessment of ADM blood flow, vessel density, vessel size, and branching pattern. The SDF microscopy was used to assess the microvascular architecture in the center and border zone of the ADM and to compare the native, non-ADM-associated capsule in each patient as a within-subject control. RESULTS: No incidences of periprosthetic infection, explantation, or adverse events were reported after SDF image acquisition. Native capsules demonstrate a complex, layered architecture with an average vessel area density of 14.9 mm/mm and total vessel length density of 12.3 mm/mm. In contrast to native periprosthetic capsules, ADM-associated capsules are not uniformly vascularized structures and demonstrate 2 zones of microvascular architecture. The ADM and native capsule border zone demonstrates palisading peripheral vascular arcades with continuous antegrade flow. The central zone of the ADM demonstrates punctate perforating vascular plexi with intermittent, sluggish flow, and intervening 2- to 3-cm watershed zones. CONCLUSIONS: Sidestream darkfield microscopy allows for real-time intraoperative assessment of ADM revascularization and serves as a potential methodology to compare revascularization parameters among commercially available ADMs. Thr SDF microscopy demonstrates that the periprosthetic capsule in ADM-assisted implant-based breast reconstruction is not a uniformly vascularized structure.

Syndactyly Web Space Reconstruction Using the Tapered M-to-V Flap: A Single-Surgeon, 30-Year Experience.

PURPOSE: To describe the technique and results of the tapered M-to-V flap for syndactyly web space construction. METHODS: We reviewed a single-surgeon, single-institution experience of all syndactyly reconstructions performed between 1982 and 2013. Demographic data and patient characteristics were recorded. Complications included flap loss, graft loss, web creep, infection, restricted range of motion, and digit deviation. RESULTS: A total of 138 web spaces were reconstructed in 93 patients. There were 89 primary congenital hand and 32 foot syndactylies. Four patients had an acquired simple incomplete syndactyly and 13 patients had secondary reconstructions. The complication rate was 14%. The most common complication was web creep resulting from partial skin graft loss (12 web spaces; 9%). There were no total flap losses. Univariate analysis revealed no factor to be predictive of an elevated complication rate. Average follow-up was 2.6 years (range, 6 mo to 26 y). CONCLUSIONS: The tapered M-to-V flap proved to be a reliable and versatile technique for web space reconstruction, offering several advantages over the standard rectangular flap method of repair, such as ease of intraoperative adjustment, a z-plasty at the palmodigital crease to minimize scar contracture, and better color match. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Acquired digital fibrokeratoma: a case report.

Acquired digital fibrokeratomas are benign, rare tumors that develop most commonly on the fingers. They can have an appearance of a rudimentary supernumerary digit or be misdiagnosed as a more common condition, such as verruca vulgaris. There are no case reports described in the plastic surgery literature. We are reporting a case that presented to our institution recently.

Postoperative outcomes and reliability of "sensation-sparing" sural nerve biopsy.

Sural nerve biopsy is a valuable tool for the diagnosis of neuropathic disorders. However, concerns of persisting pain and numbness resulting from traditional whole sural nerve biopsy have led to interfascicular dissection techniques with inconsistent benefits over whole nerve biopsy. In this study we describe a novel technique of atraumatic anterior fascicular sural nerve biopsy designed to preserve calcaneal sensation while maintaining diagnostic benefit, without requiring significant interfascicular dissection. A 10-year chart review was conducted to identify patients who underwent anterior fascicular sural nerve biopsy. Pathology reports were reviewed to confirm specimen adequacy, and clinical notes were reviewed to determine if a diagnosis was rendered. Retrospective questionnaires were conducted to evaluate perioperative and long-term sequelae and patient satisfaction. The proportion of patients with symptoms involving the heel versus the dorsolateral foot was evaluated with Fisher's exact test. Specimens from all 53 patients were acceptable and permitted a diagnosis. Twenty-two patients completed the retrospective survey with an average follow-up of 5 years (1.2-11.4 years). Eight patients (34%) experienced numbness of the dorsolateral foot, and 1 patient (4.5%) reported numbness of the lateral heel that lasted >6 months (P = 0.001). Persistent dorsolateral foot pain and cold sensitivity were reported by 5 patients (22.7%), but no patients reported lateral heel symptoms (P = 0.04). Symptoms were noted by patients most commonly while standing or walking, but they did not result in functional impairment in any case. Atraumatic anterior fascicular sural nerve biopsy predictably preserved essential lateral heel sensation in patients with neuropathic disorders while providing diagnostic utility.

Hypothenar hammer syndrome in a computer programmer: CTA diagnosis and surgical and endovascular treatment.

Finger ischemia due to embolic occlusion of digital arteries resulting from trauma to the palmar ulnar artery has been termed hypothenar hammer syndrome (HHS). In HHS, arterial thrombosis and/or aneurysm formation with embolization to the digital arteries causes symptoms of ischemia. We describe a patient in whom the initial diagnosis was made on multidetector computed tomographic angiography (CTA), as well as his endovascular and surgical management.

Effects of perivascular Botulinum Toxin-A application on vascular smooth muscle and flap viability in the rat.

Botulinum toxin-A (BTX) has become a widely used pharmacologic agent for esthetic surgeons and those who treat neuromuscular and gastrointestinal conditions. Until recently, there has been very little basic science research related to how this powerful agent may be useful when applied to vessels. The mechanism of action of this agent suggests that it may be useful in treating vasospastic conditions and ischemic tissues. We present data from experiments conducted to establish whether perivascular application of BTX decreases skin flap necrosis in an island pedicle skin flap in the rat. Using an ischemic ventral pedicled island cutaneous flap model, 30 adult Sprague-Dawley rats were divided into groups and treated with BTX, papaverine, or saline to the intact vascular pedicle to determine the percentage of tissue necrosis and ischemia. Flaps were elevated, and the pedicle treated with 1 of the 3 agents, and the flaps reinset. Analysis of the percentage of flap necrosis and areas of flap ischemia were evaluated on postoperative day 4. There were no differences in area of flap necrosis between BTX-, papaverine-, and saline-treated animal groups. There was a significant decrease in flap ischemia in the papaverine-treated group compared with both BTX and saline (P < 0.01). When necrotic and ischemic areas were combined, papaverine again showed a protective effect when compared with the BTX- and saline-treated groups (P < 0.04). In our ischemic pedicled island cutaneous flap model, papaverine showed the greatest protective effect against skin flap ischemia compared with BTX and saline. However, our data suggest that BTX may provide a protective effect after the first several days following flap elevation.

Modification of blood vessel diameter following perivascular application of botulinum toxin-A.

The purpose of this study was to demonstrate that perivascularly applied botulinum toxin-A (BTX) increases the diameter of treated blood vessels in a rat femoral vessel exposure model. Six adult Sprague-Dawley rats were used and bilateral femoral artery and vein exposures were performed. Five units of BTX were applied to the experimental side and an equal volume of sterile saline was applied to the control side. Digital images of the vessels were obtained at the following time points: pretreatment, immediately posttreatment, and postoperative days (POD) 1, 14, and 28. Vessel diameters were equivalent at baseline and immediately following application of BTX and saline. The BTX artery was significantly larger than the control artery on POD 1 and 14. The BTX treated artery was significantly larger than all other vessels on POD 14 (p < 0.05) as well as all prior time points (p < 0.01). Direct perivascular application of BTX increases the diameter of rat femoral vessels as early as POD 1. The affect is most robust on POD 14 where the artery was significantly larger than all other vessels at all time points. It is likely that the increased diameter of blood vessels results in an increased blood flow across the area of dilation. Such an increase in flow may serve to improve end-organ perfusion in microvascular procedures.

Special considerations in the management of pediatric upper extremity and hand burns.

Pediatric patients account for approximately one third of all burn patients in the United States, with upper extremity or hand involvement in most admitted burn patients. Specialized management and care of pediatric burn patients optimizes functional outcomes. Common mechanisms of injury are discussed. Acute and long-term care aspects of pediatric upper extremity and hand burns require unique considerations. Diagnosis, treatment, and management of upper extremity and hand burns are discussed in detail with respect to the pediatric population.

Plastic surgery at the University of Virginia: a 50-year retrospective.

The University of Virginia recently celebrated 50 years of plastic surgery history. Past and present chairmen were honored by the department and previous residents. Accomplishments by our department, faculty, and residents have come in areas of national leadership, education, research, and patient care. The tradition of excellence in plastic surgery continues by building upon the strong history of the department.

Topical poloxamer-188 improves blood flow following thermal injury in rat mesenteric microvasculature.

Microvascular changes of sludging and stasis are indications of thermal injury in tissue. This study investigates whether microvascular thermal injury can be decreased via topical application of poloxamer-188. Rat mesenteric microvessels were thermally injured and topically suffused with either Ringer's solution (control) or 5% poloxamer-188 in Ringer's solution (experiment). Blood flow was characterized in microvessels as normal or abnormal (ie, sludging and stasis). Topical treatment with poloxamer-188 reduced the percentage of capillaries with abnormal blood flow from 62% to 23%. In venules, this treatment resulted in a decrease from 54% to 34%. These results demonstrated that topically applied poloxamer-188 dramatically reduces the microvascular changes of sludging and stasis because of thermal injury in rat mesenteric microvessels.

Silicone gel implants in breast augmentation and reconstruction.

Silicone gel implants have been widely used for breast augmentation and reconstruction since the 1960s. Several alterations to both elastomer shell and filler gel have been made over the years to improve their ability to replicate the natural breast and to decrease the incidence of capsular contracture. The latter is a pathologic process involving the periprosthetic tissues formed in response to the presence of the implant. When severe, capsular contracture may cause firmness, distortion, and pain. In response to many claims of implant-related connective tissue disease, the US Food and Drug Administration placed a moratorium in 1992 on silicone gel breast implants for cosmetic purposes. Despite a preponderance of scientific data to their safety, silicone gel implants are presently available in the United States only as part of limited clinical trials. They continue to be used in Europe and other parts of the world.

BMP-9-transduced prefabricated muscular flaps for the treatment of bony defects.

Autologous bone grafting techniques involve the use of tissues that need to be extracted from healthy sites. This can lead to significant donor site morbidity that causes a one-site defect to become a two-site defect. Bone grafts can be especially difficult to manipulate, because bone is a relatively nonmoldable tissue. Furthermore, the inability of a bone graft to contain a transplantable vascular supply also limits the possible size that such a bone graft can be. Because of these limitations, a graft that was moldable with a vascular supply would possess significant advantages in reconstructive applications. In this research, gene therapy techniques were used to create such a graft. An adenovirus expressing BMP-9 was injected into the latissimus dorsi of a nude animal to cause bony differentiation of that muscle. Differentiation of the muscle to cartilage in bone was measured by reverse transcription polymerase chain reaction and immunohistochemistry to determine the optimal time of flap elevation. After injection of the BMP-9 virus, the animals were biopsied weekly over a 3-week period. Both bone and cartilage markers were discovered in these tissues over the study period. Optimal flap elevation time was established to be 2 weeks after injection of the virus.

Ex vivo fat graft preservation: effects and implications of cryopreservation.

There are a variety of recommended methods for harvesting, treating, and utilizing autologous fat grafts. Previous work with the MTT assay illustrated that various preimplantation handling techniques had minimal effect on the viability of fat samples. This assay was used to test the viability of harvested fat samples after being stored for up to 8 days in a variety of conditions. Surprisingly, freezing the fat before assaying also had no measurable detrimental effect, which led us to study this phenomenon in greater detail. The results demonstrated that fat stored at subzero temperatures showed remarkable maintenance of their mitochondrial metabolic activity as compared with fat stored in a 32 degrees C incubator. These data suggest exciting possibilities for storage and banking of human adipose tissue, which would reduce patient cost, discomfort, and time associated with multiple grafting procedures.

Aberrant bony vasculature associated with activating fibroblast growth factor receptor mutations accompanying Crouzon syndrome.

Fibroblast growth factor receptor mutations are associated with and, in fact, cause most syndromes presenting with craniosynostosis. This knowledge has resulted in a shift in the paradigm of suture fusion causation; it was thought previously that abnormal tensional forces arising in the cranial base caused fusion of the vault sutures, but it is now understood that aberrant intercellular signaling in the developing skull leads to abnormal suture morphogenesis. Although the mutations associated with these syndromes are known and the phenotypic consequences are well documented, the pathway from mutation to phenotype has yet to be elucidated. Surgical reconstruction is the primary treatment of craniofacial abnormalities associated with craniosynostotic syndromes such as Crouzon syndrome. In many cases, calvarial vault reshaping is dependent on the quality of the autologous bone available; however, the bone of patients with craniosynostosis syndrome is often more brittle, thinner, and less robust than cranial bone from nonaffected donors. The relation between syndromic craniosynostoses and this bone has not been previously described. In this study, the osteon and blood vessel diameters of calvarial bone from patients with Crouzon syndrome and age- and sex-matched normal calvarial bone are measured. Statistical analysis demonstrates a quantitative and significant difference in the blood vessel diameter but not in the osteon diameter. This finding could be a result of abnormal blood vessel development caused by the fibroblast growth factor receptor mutation occurring before and coincident with bone formation and leading to weakened and fragile bone tissue.

Lidocaine metabolism pathophysiology, drug interactions, and surgical implications.

A thorough understanding of the pathophysiology of lidocaine metabolism is an important prerequisite to minimizing the risk of morbidity and mortality associated with lipoplasty. Although the tumescent technique has greatly improved the safety of large-volume lipoplasty through decreased blood loss and reduced anesthetic needs, it has introduced the possibility for lidocaine toxicity. Because lidocaine is metabolized by the cytochrome P450 system, the potential for drug interactions is heightened. These drug interactions are implicated as a cause of lidocaine toxicity. A comprehensive review of the patient's preoperative, intraoperative, and postoperative medication profile is critical to perioperative patient safety.

Surgical management of the hand in Freeman-Sheldon syndrome.

Freeman-Sheldon syndrome is a rare form of distal arthrogryposis characterized by craniofacial anomalies, a rheumatoid-appearing hand, and pedal deformities. The hand deformities include ulnar deviation of the fingers, camptodactyly, first web space contracture, and hypoplasia of the thumb. Because of clinical variability and rarity, there is no standard management protocol. The authors have developed a systematic method of management of the hand in Freeman-Sheldon syndrome using principles commonly applied to other complex hand problems. In 17 years, the authors have evaluated nine patients. Of 18 hands evaluated, the authors have operated on 15. Good results were achieved in five hands and fair results in 10. There were no cases of useless hands. The authors have been most pleased with the results after crossed intrinsic transfers, centralization of extensor tendons, and intrinsic release of the thumb. Although physical deformities remain, functional adaptation is generally good.

Human adipocyte viability testing: a new assay.

BACKGROUND: Surgical experience and anecdotal data on the most effective method of harvesting, preparing, and injecting autologous fat grafts are inconsistent and conflicting. Because the limitation of fat grafting is its resorption, understanding how various handling techniques affect adipocyte survival is crucial to optimizing its long-term survival. OBJECTIVE: We sought to develop a method for assaying fat viability in its clinically used form and then to test several common techniques used in fat grafting for their effects on the viability of the fat. METHODS: We performed the well-established MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrasodium bromide] cell survival and proliferation assay on fat, but the colored enzyme-breakdown product could not be released into the supernatant for spectrophotometric analysis. An entirely new protocol was developed that allowed the MTT assay to quantitate the viability of free fat grafts. The assay was able to distinguish between different quantities of live fat and to quantify the decrease in viability when the fat is stored. We subjected the fat to various treatments, including insulin and Triton-X 100 detergent, (Sigma Aldrich, St. Louis, MO) centrifugation, extrusion through different types and sizes of needles, and freezing. RESULTS: With the exception of detergent, which decreased viability, all other treatments had no statistically significant effect on adipocyte survival. Freezing did not result in decreased cell viability. CONCLUSIONS: It is unlikely that variations in the clinical results of free fat grafting are the result of the handling techniques examined in this study.