Management of Adult Brachial Plexus Injuries.

Adult brachial plexus injuries result in profound functional deficits, debilitating pain, substantial mental health implications, and extensive economic impacts. Their initial evaluation includes a detailed physical examination, electrodiagnostic studies, advanced imaging, and patient counseling. A team-based approach, led by a peripheral nerve surgeon and including hand therapists, electrodiagnosticians, mental health experts, and pain-management specialists, is used to provide optimal longitudinal care during the lengthy recovery process. The options for the surgical management of brachial plexus injuries include exploration, neurolysis, nerve grafting, nerve transfer, free functional muscle transfer, tendon transfer, arthrodesis, and amputation. When treated within 6 months, the outcomes are favorable for the restoration of essential shoulder and elbow function. Free functional muscle transfer is a powerful tool to address elbow flexion and rudimentary grasp in both primary and delayed settings. The restoration of hand function remains a challenge for patients with complete brachial plexus injury. The purpose of this review is to summarize foundational concepts in diagnosis and management, discuss current trends and controversial topics, and address areas for future investigation.

Evolving Techniques in Peripheral Nerve Regeneration.

Reliable and robust peripheral nerve regeneration after a nerve injury and repair remains an elusive goal. A variety of strategies have been proposed to mitigate the effects of Wallerian degeneration (through molecular therapies), enhance axonal regeneration across the repair site (through electrical stimulation and gene therapy), and explore alternatives to suture coaptation (through the fusion of transected ends). Although most of these techniques are in their infancy, animal data and some clinical trials have demonstrated promise for improving the restoration of function after these devastating injuries.

Impact of Postoperative Antibiotic Prophylaxis Duration on Surgical Site Infections in Autologous Breast Reconstruction.

BACKGROUND: Although some surgeons prescribe prolonged postoperative antibiotics after autologous breast reconstruction, evidence is lacking to support this practice. We used the Tracking Operations and Outcomes for Plastic Surgeons database to evaluate the association between postoperative antibiotic duration and the rate of surgical site infection (SSI) in autologous breast reconstruction. STUDY DESIGN: The intervention of interest for this study was postoperative duration of antibiotic prophylaxis: either discontinued 24 hours after surgery or continued beyond 24 hours. The primary outcome variable of interest for this study was the presence of SSI within 30 days of autologous breast reconstruction. Cohort characteristics and 30-day outcomes were compared using χ² and Fischer exact tests for categorical variables and Student t tests for continuous variables. Multivariate logistic regression was used to control for confounders. RESULTS: A total of 1036 patients met inclusion criteria for our study. Six hundred fifty-nine patients (63.6%) received antibiotics for 24 hours postoperatively, and 377 patients (36.4%) received antibiotics for greater than 24 hours. The rate of SSI did not differ significantly between patients given antibiotics for only 24 hours and those continued on antibiotics beyond the 24-hour postoperative time period (5.01% vs 2.92%, P = 0.109). Furthermore, antibiotic duration was not predictive of SSI in multivariate regression modeling. CONCLUSIONS: We did not find a statistically significant difference in the rate of SSI in patients who received 24 hours of postoperative antibiotics compared to those that received antibiotics for greater than 24 hours. These findings held for both purely autologous reconstruction as well as latissimus dorsi reconstruction in conjunction with an implant. Thus, our study does not support continuation of postoperative antibiotics beyond 24 hours after autologous breast reconstruction.

Trends in Brachial Plexus Surgery: Characterizing Contemporary Practices for Exploration of Supraclavicular Plexus.

BACKGROUND: There is variability in treatment strategies for patients with brachial plexus injury (BPI). We used qualitative research methods to better understand surgeons' rationale for treatment approaches. We hypothesized that distal nerve transfers would be preferred over exploration and nerve grafting of the brachial plexus. METHODS: We conducted semi-structured interviews with BPI surgeons to discuss 3 case vignettes: pan-plexus injury, upper trunk injury, and lower trunk injury. The interview guide included questions regarding overall treatment strategy, indications and utility of brachial plexus exploration, and the role of nerve grafting and/or nerve transfers. Interview transcripts were coded by 2 researchers. We performed inductive thematic analysis to collate these codes into themes, focusing on the role of brachial plexus exploration in the treatment of BPI. RESULTS: Most surgeons routinely explore the supraclavicular brachial plexus in situations of pan-plexus and upper trunk injuries. Reasons to explore included the importance of obtaining a definitive root level diagnosis, perceived availability of donor nerve roots, timing of anticipated recovery, plans for distal reconstruction, and the potential for neurolysis. Very few explore lower trunk injuries, citing concern with technical difficulty and unfavorable risk-benefit profile. CONCLUSIONS: Our analysis suggests that supraclavicular exploration remains a foundational component of surgical management of BPI, despite increasing utilization of distal nerve transfers. Availability of abundant donor axons and establishing an accurate diagnosis were cited as primary reasons in support of exploration. This analysis of surgeon interviews characterizes contemporary practices regarding the role of brachial plexus exploration in the treatment of BPI.

Spatiotemporal progression of cell death in the zone of ischemia surrounding burns.

Burns are dynamic injuries, characterized by progressive death of surrounding tissue over time. Although central to an understanding of burn injury progression, the spatiotemporal degrees and rates of cellular necrosis and apoptosis in the zone of ischemia surrounding burns are not well characterized. Using a validated porcine hot comb model, we probed periburn tissue at 1, 4, and 24 hours after injury for high-mobility group box 1 as a marker of necrosis and activated cleaved caspase-3 as a marker of apoptosis, followed by spatiotemporal morphometric analysis. We found that necrosis was the most prominent mechanism of cell death in burn injury progression, with significant progression between 1 and 4 hours postburn. Apoptosis appeared not to play a role in early burn injury progression but was observed in cells at the interface of necrotic and viable tissue at 24 hours postburn. Our findings imply that intervention within the first 4 hours following injury is likely necessary to limit burn injury progression. Additionally, based on high-mobility group box 1 staining patterns, we define distinct early, intermediate, and late pathological signs of cell necrosis that may facilitate delineation of causal mechanistic relationships of burn injury progression in vivo.

Current practice among plastic surgeons of antibiotic prophylaxis and closed-suction drains in breast reconstruction: experience, evidence, and implications for postoperative care.

BACKGROUND: Despite their widespread use, there are no evidence-based guidelines on the management of closed-suction drains or antibiotics in postmastectomy breast reconstruction. The purpose of this study was to assess consensus and variation in postoperative care among plastic surgeons. METHODS: The authors designed and administered a self-reported, anonymous survey to 4669 American Society of Plastic Surgeons and Canadian Society of Plastic Surgeons members in October 2009. RESULTS: A total of 650 completed surveys were available for analysis. A majority (>81%) of respondents reported using closed-suction drains in breast reconstruction. Most surgeons (>93%) used a volume criteria for drain removal, most commonly when drain output was ≤30 mL over 24 hours (>86%). Preoperative antibiotic use was nearly universal (98%), usually consisting of intravenous cefazolin (97%). Postoperative care demonstrated less uniformity with outpatient antibiotics administered by 72% of respondents. Surgeons were divided on when to discontinue outpatient antibiotics: 46% preferred concomitant discontinuation with drains, whereas 52% preferred a specific postoperative day. No clear consensus was observed for the number (1 or 2) or type (Jackson-Pratt or Blake) of drains used. Respondents were further divided on the restriction of postoperative showering with drains and the use of acellular dermal matrix. CONCLUSIONS: These results demonstrate a consensus for drain use, drain removal, and preoperative antibiotic administration. There was no consensus for number or type of drain used, postoperative antibiotic use, shower restrictions, and use of acellular dermal matrix. Our results further emphasize the need for evidence-based postoperative-care guidelines specific to breast reconstruction.

Calcaneal Reconstruction With Femoral Head Allograft Vascularized by an Osteocutaneous Medial Femoral Condyle Flap: A Case Report.

CASE: A 25-year-old man presented with a closed calcaneal fracture after a 6-storey fall, complicated by osteomyelitis from fixation attempts necessitating near-complete debridement of his calcaneal tuberosity. He underwent a successful single-stage calcaneal and soft-tissue reconstruction using a femoral head structural allograft vascularized with an osteocutaneous medial femoral condyle flap. At the 18-month follow-up, his limb is largely pain-free and functional, allowing ambulation and his combined allograft-vascularized bone reconstruction shows radiographic evidence of incorporation. CONCLUSION: Calcaneal tuberosity reconstruction with a femoral head structural allograft and vascularized bone flap is a viable option for calcaneal tuberosity bone loss because of injury/infection.

The effect of acellular dermal matrix use on complication rates in tissue expander/implant breast reconstruction.

Tissue expander/implant breast reconstructions by 5 surgeons at a single institution from 2005 to 2008 were retrospectively identified and divided into 2 cohorts: use of acellular dermal matrix (ADM, n = 75) versus standard submuscular placement (n = 52). The ADM group had a statistically significant higher rate of infection (28.9% vs. 12.0%, P = 0.022), reoperation (25.0% vs. 8.0%, P = 0.011), expander explantation (19.2% vs. 5.3%, P = 0.020), and overall complications (46.2% vs. 22.7%, P = 0.007). When stratifying by breast size, a higher complication rate was not observed with the use of ADM in breasts less than 600 g, whereas ADM use in breasts larger than 600 g was associated with a statistically significant higher rate of infection when controlling for the occurrence of skin necrosis. The ADM cohort had a significantly higher mean initial tissue expander fill volume (256 mL vs. 74 mL, P < 0.001) and a significantly higher mean initial tissue expander fill ratio (49% vs. 17%, P < 0.001). Further work is needed to define the ideal patient population for ADM use in tissue expander/implant breast reconstruction.

Targeted Muscle Reinnervation as a Solution for Nerve Pain.

LEARNING OBJECTIVES: After reading this article, the participants should be able to: 1. List current nonsurgical and surgical strategies for addressing postamputation neuroma pain and discuss their limitations. 2. Summarize the indications and rationale for targeted muscle reinnervation. 3. Develop an operative plan for targeted muscle reinnervation in an acute or delayed fashion for upper and lower extremity amputations. 4. Propose a management algorithm for treatment of symptomatic neuromas in an intact limb. 5. Discuss the risk of neuroma development after primary revision digital amputation or secondary surgery for a digital neuroma. 6. Compare and contrast targeted muscle reinnervation to the historical gold standard neuroma treatment of excision and burying the involved nerve in muscle, bone, or vein graft. 7. Interpret and discuss the evidence that targeted muscle reinnervation improves postamputation neuroma and phantom pain when performed either acutely or in a delayed fashion to treat existing pain. SUMMARY: Symptomatic injured nerves resulting from amputations, extremity trauma, or prior surgery are common and can decrease patient quality of life, thus necessitating an effective strategy for management. Targeted muscle reinnervation is a modern surgical strategy for prevention and treatment of neuroma pain that promotes nerve regeneration and healing rather than neuroma formation. Targeted muscle reinnervation involves the transfer of cut peripheral nerves to small motor nerves of adjacent, newly denervated segments of muscle and can be easily performed without specialized equipment. Targeted muscle reinnervation strategies exist for both upper and lower extremity amputations and for symptomatic neuromas of intact limbs. Targeted muscle reinnervation has been shown in a prospective, randomized, controlled trial to result in lower neuroma and phantom pain when compared to the historical gold standard of burying cut nerves in muscle.

Approach to the Pan-brachial Plexus Injury: Variation in Surgical Strategies among Surgeons.

Treatment of pan-brachial plexus injuries has evolved significantly over the past 2 decades, with refinement and introduction of new surgical techniques, particularly free functional muscle transfer. The extent to which contemporary brachial plexus surgeons utilize various techniques as part of their treatment algorithm for pan-plexus injuries and the rationale underlying these choices remain largely unknown. METHODS: A case scenario was posed to 12 brachial plexus surgeons during semi-structured qualitative interviews. The case involved a young patient presenting 6 weeks after a pan-plexus injury from a motorcycle accident. Surgeons were asked to formulate a treatment plan. Inductive thematic analysis was used to identify commonalities and variation in approach to treatment. RESULTS: For shoulder function, the majority of surgeons would graft from a viable C5 nerve root, if possible, though the chosen target varied. Two-thirds of the surgeons would address elbow flexion with nerve transfers, though half would combine this with a free functional muscle transfer to increase elbow flexion strength. Free functional muscle transfer was the technique of choice to restore finger flexion. Finger extension, intrinsic function, and sensation were not prioritized. CONCLUSIONS: Our study sheds light on current trends in the approach to pan-plexus injuries in the U.S. and identifies areas of variability that would benefit from future study. The optimal shoulder target and the role for grafting to the MCN for elbow flexion merit further investigation. The role of FFMT plays an increasingly prominent role in treatment algorithms.

Vertical Skin Paddle Orientation for the Latissimus Dorsi Flap in Breast Reconstruction: A Modification to Simultaneously Correct Inferior Pole Constriction and Improve Projection.

The latissimus dorsi myocutaneous flap is a reliable and frequently used option to bring vascularized skin and soft tissue to improve the stability and aesthetic result in breast reconstruction. Standard techniques with skin paddle inset in a horizontal or oblique fashion preferentially improve anterior projection (when inset at the mastectomy scar) or lower pole and inframammary fold constriction (when inset into the inframammary fold). Here, the authors describe a modification for inset of the latissimus dorsi myocutaneous flap that improves both anterior projection and lower pole/inframammary fold constriction, and also allows the latissimus muscle to fan out and provide complete implant coverage. The vertical inset modification brings new skin and soft tissue into both the inferior pole and the central mastectomy scar, allowing simultaneous improvement in both areas and full use of the latissimus muscle to cover the implant or expander. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Intraoperative Nerve Blocks Fail to Improve Quality of Recovery after Tissue Expander Breast Reconstruction: A Prospective, Double-Blinded, Randomized, Placebo-Controlled Clinical Trial.

BACKGROUND: The authors' study represents the first level I evidence to assess whether intraoperative nerve blocks improve the quality of recovery from immediate tissue expander/implant breast reconstruction. METHODS: A prospective, randomized, double-blinded, placebo-controlled clinical trial was conducted in which patients undergoing immediate tissue expander/implant breast reconstruction were randomized to either (1) intraoperative intercostal and pectoral nerve blocks with 0.25% bupivacaine with 1:200,000 epinephrine and 4 mg of dexamethasone or (2) sham nerve blocks with normal saline. The 40-item Quality of Recovery score, pain score, and opioid use in the postoperative period were compared statistically between groups. Power analysis ensured 80 percent power to detect a 10-point (clinically significant) difference in the 40-item Quality of Recovery score. RESULTS: Forty-seven patients were enrolled. Age, body mass index, laterality, mastectomy type, and lymph node dissection were similar between groups. There were no statistical differences in quality of recovery, pain burden as measured by visual analogue scale, opioid consumption, antiemetic use, or length of hospital stay between groups at 24 hours after surgery. Mean global 40-item Quality of Recovery scores were 169 (range, 155 to 182) for the treatment arm and 165 (range, 143 to 179) for the placebo arm (p = 0.36), indicating a high quality of recovery in both groups. CONCLUSION: Although intraoperative nerve blocks can be a safe adjunct to a comprehensive postsurgical recovery regimen, the authors' results indicate no effect on overall quality of recovery from tissue expander/implant breast reconstruction. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, I.

Mesh sutured repairs of contaminated incisional hernias.

BACKGROUND: We sought to evaluate the results of a new mesh sutured repair technique for closure of contaminated incisional hernias. METHODS: 48 patients with contaminated hernias 5 cm wide or greater by CT scan were closed with mesh sutures. Surgical site occurrence, infections, and hernia recurrence were compared to similar patient series reported in the literature. RESULTS: Of the 48 patients, 20 had clean-contaminated wounds, 16 had contaminated wounds, and 12 were infected. 69% of the patients underwent an anterior perforator sparing components release for hernias that averaged 10.5 cm transversely (range 5 cm-25 cm). SSO occurred in 27% of patients while SSI was 19%. There were no fistulas or delayed suture sinuses. With a mean follow-up of almost 12 months, 3 midline hernias recurred (6%). In these same patients, three parastomal hernias repaired with mesh sutures failed out of 4 attempted for a total failure rate of 13%. CONCLUSION: Mesh sutured closure represents a simplified and effective surgical strategy for contaminated midline incisional hernia repair.

Residual sodium dodecyl sulfate in decellularized muscle matrices leads to fibroblast activation in vitro and foreign body response in vivo.

Detergents such as sodium dodecyl sulfate (SDS) are commonly used to extract cells from tissues in a process called "decellularization". Residual SDS is difficult to completely remove and may lead to an undesirable host response towards an implanted biomaterial. In this study, we developed a modification for SDS cell extraction from muscle equally efficient to previous methods but leading to significantly less residual SDS remnants in the matrices. Muscle-derived matrices were prepared via 2 SDS-based decellularization methods, which led to removal of either 81.4% or 98.4% of the SDS. In vitro, matrices were seeded with thp1 macrophages and primary human foreskin fibroblasts. By Day 2, both matrices demonstrated similar macrophage polarization; however, fibroblasts cultured on matrices with greater residual SDS expressed higher levels of mRNA associated with fibroblast activation: α-smooth muscle actin and connective tissue growth factor. In vivo, Collagen I gels spiked with increasing concentrations of SDS displayed a corresponding decrease in cell infiltration when implanted subcutaneously in rats after 4 days. Finally, as a model for muscle regeneration, matrices produced by each method were implanted in rat latissimus dorsi defects. At POD 30 greater levels of IL-1ß mRNA were present in defects treated with matrices containing higher levels of SDS, indicating a more severe inflammatory response. Although matrices containing higher levels of residual SDS became encapsulated by POD 30 and showed evidence of a foreign body response, matrices with the lower levels of SDS integrated into the defect area with lower levels of inflammatory and fibrosis-related gene expression.

Current Risk Stratification Systems Are Not Generalizable across Surgical Technique in Midline Ventral Hernia Repair.

BACKGROUND: Current ventral hernia repair risk estimation tools focus on patient comorbidities with the goal of improving clinical outcomes through improved patient selection. However, their predictive value remains unproven. METHODS: Outcomes of patients who underwent midline ventral hernia repair with retrorectus placement of mid-weight soft polypropylene mesh between 2010 and 2015 were retrospectively reviewed and compared with predicted wound-related complication risk from 3 tools in the literature: Carolinas Equation for Determining Associated Risk, the Ventral Hernia Working Group (VHWG) grade, and a modified VHWG grade. RESULTS: A total of 101 patients underwent hernia repair. Mean age was 56 years and mean body mass index was 29 m/kg2 (range, 18-51 m/kg2). We found no significant relationship between the risk estimated by Carolinas Equation for Determining Associated Risk (B = 1.45, P = 0.61) and actual wound-related complications. VHWG grades >1 were not statistically different with regard to rate of wound complication compared with VHWG grade 1 (grade 2: B = 0.05, P = 0.95; grade 3: B = -0.21, P = 0.86; grade 4: B = 2.57, P = 0.10). Modified VHWG grades >1 were not statistically different with regard to rate of wound complication compared with modified VHWG grade 1 (grade 2: B = 0.20, P = 0.80; grade 3: B = 1.03, P = 0.41). CONCLUSIONS: Current risk stratification tools overemphasize patient factors, ignoring the importance of technique in minimizing complications and recurrence. We attribute our low complication rate to retrorectus placement of a narrow, macroporous polypropylene mesh with up to 45 suture fixation points for force distribution in contrast to current strategies that employ wide meshes with minimal fixation.

State of the Plastic Surgery Workforce and the Impact of Graduate Medical Education Reform on Training of Plastic Surgeons.

BACKGROUND: Although recent estimates predict a large impending shortage of plastic surgeons, graduate medical education funding through the Centers for Medicare and Medicaid Services remains capped by the 1997 Balanced Budget Act. The authors' aim was to develop a plan to stimulate legislative action. METHODS: The authors reviewed responses of the American Society of Plastic Surgeons, American College of Surgeons, and American Medical Association from January of 2015 to a House Energy & Commerce Committee request for input on graduate medical education funding. In addition, all program directors in plastic surgery were surveyed through the American Council of Academic Plastic Surgeons to determine their graduate medical education funding sources. RESULTS: All three organizations agree that current graduate medical education funding is inadequate to meet workforce needs, and this has a significant impact on specialty selection and distribution for residency training. All agreed that funding should be tied to the resident rather than to the institution, but disagreed on whether funds should be divided between direct (allocated to residency training) and indirect (allocated to patient care) pools, as is currently practiced. Program directors' survey responses indicated that only 38 percent of graduate medical education funds comes from the Centers for Medicare and Medicaid Services. CONCLUSIONS: Organized medicine is at risk of losing critically needed graduate medical education funding. Specific legislation to support additional graduate medical education positions and funding (House Resolutions 1180 and 4282) has been proposed but has not been universally endorsed, in part because of a lack of collaboration in organized medicine. Collaboration among major organizations can reinvigorate these measures and implement real change in funding.

Adipose Tissue Drives Response to Ischemia-Reperfusion Injury in a Murine Pressure Sore Model.

BACKGROUND: Ischemia-reperfusion injury contributes significantly to the pathogenesis of chronic wounds such as pressure sores and diabetic foot ulcers. The authors' laboratory has previously developed a cyclical murine ischemia-reperfusion injury model. The authors here use this model to determine factors underlying tissue response to ischemia-reperfusion injury. METHODS: C57BL/6 mice were subjected to cycles of ischemia-reperfusion that varied in number (one to four cycles) and duration of ischemia (1 to 2 hours). For each ischemia-reperfusion condition, the following variables were analyzed: (1) digital photographs for area of necrosis; (2) hematoxylin and eosin staining and immunohistochemistry for inflammatory infiltrate; and (3) expression of inflammatory markers by quantitative polymerase chain reaction. In addition, human adipocytes and fibroblasts were cultured in vitro under conditions of hypoxia and reoxygenation, and expression of inflammatory markers was analyzed by quantitative polymerase chain reaction. RESULTS: Increases in both ischemia-reperfusion cycle number and ischemia duration correlated with increased areas of epithelial necrosis both grossly and histologically, and with an increase in cellularity and neutrophil density. This increased inflammatory infiltrate and a significant increase in the expression of proinflammatory markers (Hmox1, interleukin-6, interleukin-1, and monocyte chemoattractant protein-1) was observed in adipose tissue subjected to ischemia-reperfusion injury, but not in dermis. These results were mirrored in human adipose tissue. CONCLUSIONS: The authors further characterize a novel, reproducible murine model of ischemia-reperfusion injury. The results of their study indicate that adipose tissue is less tolerant of ischemia-reperfusion than dermal tissue. Rather than being an "innocent bystander," adipose tissue plays an active role in driving the inflammatory response to ischemia-reperfusion injury.

Reliable complex abdominal wall hernia repairs with a narrow, well-fixed retrorectus polypropylene mesh: A review of over 100 consecutive cases.

BACKGROUND: Our objective was to determine outcomes for complex ventral hernia repairs in a large cohort of patients utilizing an operative construct employing retrorectus placement of a narrow, macroporous polypropylene mesh with up to 45 suture fixation points for force distribution. No consensus exists on the optimal technique for repair of complex ventral hernias. Current trends emphasize large meshes with wide overlaps and minimal suture fixation, though reported complications and recurrence remain problematic. METHODS: A retrospective review was performed for all patients undergoing ventral hernia repair with retrorectus placement of midweight, uncoated, soft polypropylene mesh by a single surgeon (GAD) between the years of 2010 and 2015. Patient characteristics, operative history, operative data, and postoperative course were reviewed. RESULTS: A total of 101 patients with a mean age of 56 years and a mean body mass index of 29 m/kg2 (range 18-51 m/kg2) underwent hernia repair. Patients had a median of 3 prior abdominal operations (range 0-9), with 44 patients presenting with recurrent hernias. A total of 42 patients were Ventral Hernia Working Group grade 1, 40 grade 2, 17 grade 3, and 2 grade 4. There were no recurrences at a mean follow-up of almost 400 days for the 93 patients with long-term follow-up. The surgical site occurrence rate was 7.9% (3 surgical site infections, 2 seromas, 2 hematomas, and 4 instances of delayed wound healing in 8 patients). One patient required reoperation for hematoma drainage; 5 patients required readmission within 30 days. CONCLUSION: An operative construct employing a retrorectus placement of a narrow, macroporous polypropylene mesh with up to 45 suture fixation points for force distribution can achieve significantly better outcomes across a spectrum of Ventral Hernia Working Group grade, risk-stratified patients compared to rates reported in the literature for current strategies that employ wide meshes with minimal fixation.

The Northwestern Abdominoplasty Scar Model: A Novel Human Model for Scar Research and Therapeutics.

There is a growing interest in the development and evaluation of therapeutic agents that improve the cosmetic appearance of scars. Existing nonhuman animal models to study scarring, while valuable, have well-acknowledged limitations, as it is accepted that the biology of human scarring differs significantly from scarring in other species. Moreover, human clinical trials of scarring require large numbers of subjects to achieve statistical power and are plagued by inherent intersubject variability because of the complex nature of wound healing in human beings. As a better alternative, we have developed the Northwestern Abdominoplasty Scar Model-a novel human clinical model that permits analysis of up to 20 cutaneous scars in a single subject and allows for not only visual scar comparison, but also histologic and molecular analyses of factors involved in scarring and wound healing. We have utilized this model in 5 early phase clinical trials designed to test the safety and efficacy of a variety of scar therapeutics without any complications to date. The model not only is applicable to scar therapeutics, but also can be utilized for other applications, such as the testing of implantable biomaterials, injectable products, therapies such as lasers, or even for in vivo study of wound healing processes in humans.