Amy S. Colwell

Inferolateral AlloDerm hammock for implant coverage in breast reconstruction.

Purpose:Implant reconstruction is commonly performed to reconstruct mastectomy defects or to correct breast hypoplasia. We have been using an inferolateral AlloDerm hammock as an inferior extension of the pectoralis major muscle to provide a mechanical barrier between the implant and skin and to control implant position. Methods:The inferior border of the AlloDerm hammock is attached inferiorly to the rectus abdominis fascia and laterally to the serratus anterior fascia to create the borders of the implant pocket. The AlloDerm is then sewn to the pectoralis major muscle to enclose the implant. Results:The AlloDerm hammock was used in 43 patients and 67 breasts for immediate expander-implant reconstruction (10), immediate silicone implant reconstruction (30), delayed expander-implant reconstruction (4), and revisional implant reconstruction for capsular contracture following capsulectomy (23). The AlloDerm hammock allowed complete coverage of the implant and symmetric positioning of the inframammary fold. In delayed reconstructions with existing skin redundancy at the mastectomy site, inferior epigastric tissue was recruited and tissue expanders filled over 75% of the desired volume, thus decreasing the need for subsequent filling. Patients were overall satisfied with their results and had few complications. No capsular contracture, hematoma, or seroma was observed in 6 months to 3 years of follow-up. Conclusion:Implant reconstruction with an inferolateral AlloDerm hammock facilitates positioning of the implant in immediate or revisional breast reconstruction and simplifies expander-implant reconstruction. This safe technique is easy to learn and should be considered a viable option for breast reconstruction.

Fetal wound healing.

The developing fetus has the ability to heal wounds by regenerating normal epidermis and dermis with restoration of the extracellular matrix (ECM) architecture, strength, and function. In contrast, adult wounds heal with fibrosis and scar. Scar tissue remains weaker than normal skin with an altered ECM composition. Despite extensive investigation, the mechanism of fetal wound healing remains largely unknown. We do know that early in gestation, fetal skin is developing at a rapid pace and the ECM is a loose network facilitating cellular migration. Wounding in this unique environment triggers a complex cascade of tightly controlled events culminating in a scarless wound phenotype of fine reticular collagen and abundant hyaluronic acid. Comparison between postnatal and fetal wound healing has revealed differences in inflammatory response, cellular mediators, cytokines, growth factors, and ECM modulators. Investigation into cell signaling pathways and transcription factors has demonstrated differences in tyrosine phosphorylation patterns and homeobox gene expression. Further research may reveal novel genes essential to scarless repair that can be manipulated in the adult wound and thus ameliorate scar.

Breast reconstruction following nipple-sparing mastectomy: predictors of complications, reconstruction outcomes, and 5-year trends.

Background: Nipple-sparing mastectomy is increasingly used for treatment and prevention of breast cancer. Few data exist on risk factors for complications and reconstruction outcomes. Methods: A single-institution retrospective review was performed between 2007 and 2012. Results: Two hundred eighty-five patients underwent 500 nipple-sparing mastectomy procedures for breast cancer (46 percent) or risk reduction (54 percent). The average body mass index was 24, and 6 percent were smokers. The mean follow-up was 2.17 years. Immediate breast reconstruction (reconstruction rate, 98.8 percent) was performed with direct-to-implant (59 percent), tissue expander/implant (38 percent), or autologous (2 percent) reconstruction. Acellular dermal matrix was used in 71 percent and mesh was used in 11 percent. Seventy-seven reconstructions had radiotherapy. Complications included infection (3.3 percent), skin necrosis (5.2 percent), nipple necrosis (4.4 percent), seroma (1.7 percent), hematoma (1.7 percent), and implant loss (1.9 percent). Positive predictors for total complications included smoking (OR, 3.3; 95 percent CI, 1.289 to 8.486) and periareolar incisions (OR, 3.63; 95 percent CI, 1.850 to 7.107). Increasing body mass index predicted skin necrosis (OR, 1.154; 95 percent CI, 1.036 to 1.286) and preoperative irradiation predicted nipple necrosis (OR, 4.86; 95 percent CI, 1.0197 to 23.169). An inframammary fold incision decreased complications (OR, 0.018; 95 percent CI, 0.0026 to 0.12089). Five-year trends showed increasing numbers of nipple-sparing mastectomy with immediate reconstruction and more single-stage versus two-stage reconstructions (p < 0.05). Conclusions: Nipple-sparing mastectomy reconstructions have a low number of complications. Smoking, body mass index, preoperative irradiation, and incision type were predictors of complications. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.

Hypertrophic scar fibroblasts have increased connective tissue growth factor expression after transforming growth factor-beta stimulation.

Background: Hypertrophic scars and keloids respond to dermal disruption with excessive collagen deposition and increased transforming growth factor (TFG)-β expression. Connective tissue growth factor (CTGF) is a downstream mediator of TGF-β activity that is associated with scar and fibrosis. The authors hypothesize that there is increased expression of CTGF by hypertrophic scar and keloid fibroblasts in response to TGF-β stimulation. Methods: Primary fibroblasts were isolated in culture from human hypertrophic scar (n = 2), keloid (n = 2), and normal skin (n = 2). After 18 hours of serum starvation, the cells were stimulated with 10 ng/ml of TGF-β1, TGF-β2, and TGF-β3 for 24 hours. Quantitative real-time polymerase chain reaction was performed on extracted RNA samples to assay for CTGF mRNA expression. Results: Baseline CTGF expression was increased 20-fold in unstimulated hypertrophic scar fibroblasts and 15-fold in keloid fibroblasts compared with normal fibroblasts. CTGF expression increased greater than 150-fold when stimulated with TGF-β1 (p < 0.002) and greater than 100-fold when stimulated by TGF-β2 or TGF-β3 compared with normal fibroblasts (p < 0.02 and p < 0.002, respectively). CTGF expression was greatest after TGF-β1 stimulation in hypertrophic scar fibroblasts compared with TGF-β2 (p < 0.04) and TGF-β3 (p < 0.02). Keloid fibroblast CTGF expression also increased greater than 100-fold after stimulation with TGF-β1 (p = 0.16) and greater than 75-fold after addition of TGF-β2 and TGF-β3 (p = 0.06 and p = 0.22, respectively). Conclusions: Hypertrophic scar fibroblasts have both intrinsic up-regulation of CTGF transcription and an exaggerated capacity for CTGF transcription in response to TGF-β stimulation. These data suggest that blockage of CTGF activity may reduce pathologic scar formation.

Occult breast carcinoma in reduction mammaplasty specimens: 14-year experience.

Reduction mammaplasty is commonly performed for bilateral macromastia, congenital asymmetry, or as a contralateral symmetry procedure in breast reconstruction following mastectomy for cancer. Occult carcinoma has been detected in 0.06 percent to 0.4 percent of breast reduction specimens. The purpose of this study was to examine the incidence of breast cancer in breast reductions performed in one institution over a 14-year period. The authors reviewed their experience with 800 reduction mammaplasties performed between 1988 and 2001. Six cancers were detected (0.8 percent). Of these cancers, three were invasive (0.4 percent) and three were ductal carcinoma in situ (0.4 percent). Stratified by indication for surgery, there was a trend toward higher detection rates in the reconstruction group (1.2 percent) compared with the macromastia (0.7 percent) or congenital asymmetry (0 percent) groups. Mammography was performed preoperatively in these patients and all results were negative for masses or suspicious microcalcification. Pathological diagnosis was guided by gross specimen evaluation in two patients and specimen radiography in one patient. Reduction mammaplasty has a small but definite risk of finding cancer in the resection specimen.

Infection following implant-based reconstruction in 1952 consecutive breast reconstructions: salvage rates and predictors of success.

Background: Few studies address salvage rates for infection in implant-based breast reconstruction. An understanding of success rates and clinical predictors of failure may help guide management. Method: A retrospective analysis of multisurgeon consecutive implant reconstructions from 2004 to 2010 was performed. Results: Immediate implant-based reconstructions (n = 1952) were performed in 1241 patients. Ninety-nine reconstruction patients (5.1 percent) were admitted for breast erythema and had a higher incidence of smoking (p = 0.007), chemotherapy (p = 0.007), radiation therapy (p = 0.001), and mastectomy skin necrosis (p < 0.0001). There was no difference in age, body mass index, or acellular dermal matrix usage. With intravenous antibiotics, 25 (25.3 percent) reconstruction patients cleared the infection, whereas 74 (74.7 percent) underwent attempted operative salvage (n = 18) or explantation (n = 56). Patients who failed to clear infection had a higher mean white blood cell count at admission (p < 0.0001). Of the attempted operative salvage group, 12 cleared the infection with immediate implant exchange and six eventually lost the implant. Patients who failed implant salvage were more likely to have methicillin-resistant Staphylococcus aureus (p = 0.004). The total explantation rate was 3.2 percent. Following explantation, 32 patients underwent attempted secondary tissue expander insertion. Twenty-six were successful and six had recurrent infection and implant loss. There were no differences in time interval to tissue expander insertion between successful and unsuccessful secondary operations. Conclusions: Salvage with intravenous antibiotics and implant exchange was successful in 37.3 percent of patients. Smoking, irradiation, chemotherapy, and mastectomy skin necrosis were predictors for developing infection. Patients with a higher white blood cell count at admission and methicillin-resistant S. aureus were more likely to fail implant salvage. There was no association with time interval to tissue expander insertion and secondary explantation.(Plast. Reconstr. Surg. 131: 1223, 2013.) CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Management of early groin vascular bypass graft infections with sartorius and rectus femoris flaps

Groin infections adjacent to vascular bypass grafts continue to be a source of morbidity. The authors reviewed retrospectively 9 consecutive patients with early localized groin infections treated at their institution with sartorius or rectus femoris muscle flaps between 1998 and 2002. All wounds were initially opened and drained. Wounds with necrotic tissue were treated with serial surgical debridements, with a vacuum-assisted closure device, or with wet-to-dry dressing changes. Two bypass grafts were excised and replaced in the presence of marked exposure or pseudoaneurysm. Small wounds were closed with a turnover sartorius flap and larger wounds were closed with either a muscle or musculocutaneous rectus femoris flap. Groin wounds healed in all patients without subsequent graft exposure, rupture, or pseudoaneurysm. Local wound therapy with staged debridement and muscle flaps is effective for most early localized graft infections.

An in vivo mouse excisional wound model of scarless healing.

Background: The purpose of this study was to develop a reproducible murine model of fetal scarless wound healing. Methods: One-millimeter excisional wounds were made in fetal skin at gestational days 16.5 (E17) and 18.5 (E19) (term = day 21.5, or E22) and marked with India ink. Fetal mortality was less than 30 percent in E17 fetuses and 0 percent in E19 fetuses. Control postnatal 2-mm open wounds were made in 3-week-old mice. Results: At 48 hours, E17 skin wounds had healed completely. E19 skin wounds also healed but were marked by skin irregularity at the wound site. Histologically, E17 wounds had fine reticular collagen architecture by trichrome staining and hair follicle regeneration. In contrast, E19 wounds healed with collagen deposition and scar formation and no hair follicle regeneration. Conclusions: The authors have developed a reliable mouse model of fetal scarless repair to help elucidate the mechanism of scarless wound healing to take advantage of genetically modified animals. The knowledge gained may be used to manipulate scarring in the adult to produce a more fetal-like wound.

Skin wounds in the MRL/MPJ mouse heal with scar

Adult MRL/MpJ mice regenerate cartilage during repair of through‐and‐through ear punch wounds. However, the ability of this mouse strain to heal isolated cutaneous wounds by regeneration or with scar is unknown. The purpose of this study was to characterize the rate of reepithelialization and collagen architecture in dermal wounds from MRL/MpJ mice compared with C57bl/6 and Balb/c strains. Full‐thickness incisional (5 mm) and excisional (2 mm diameter) skin wounds were made on the dorsum of 7‐week‐old MRL/MpJ, C57bl/6, and Balb/c mice. Ear punch wounds were made simultaneously on each animal. Reepithelialization was complete by 48 hours for incisional skin wounds in each strain. All excisional wounds showed incomplete reepithelialization at 24, 48, and 72 hours. At 14 days, all skin wounds had grossly healed. In contrast to the ear wounds made in C57bl/6 and Balb/c mice, MRL/MpJ ear wounds were completely healed by day 28. Dorsal skin wound sections at 14 and 28 days revealed dense collagen deposition and similar degrees of fibrosis between the three strains of mice. In conclusion, in contrast to wound healing in the ear, MRL/MpJ mouse dorsal cutaneous wounds heal similarly to C57bl/6 and Balb/c mice with dermal collagen deposition and scar formation.

Breast reconstruction outcomes after nipple-sparing mastectomy and radiation therapy.

Background: Few studies in the literature examine outcomes of immediate breast reconstruction after mastectomy with nipple preservation and radiation therapy. Methods: Retrospective analysis of multisurgeon consecutive implant-based reconstructions after nipple-sparing mastectomy from June of 2007 to December of 2012 was conducted at a single institution. Results: Six hundred five immediate breast reconstructions were performed following nipple-sparing mastectomy, of which 88 were treated with radiation therapy. There was a trend toward more complications in patients with radiation (19.3 percent versus 12.8 percent; p = 0.099) associated with a higher rate of implant loss (6.8 percent versus 1.0 percent; p = 0.001). Preoperative radiotherapy had a higher risk of total complications (p = 0.04; OR, 2.225; 95 percent CI, 1.040 to 4.758) and postoperative radiotherapy had a higher risk of explantation (p = 0.015; OR, 5.634; 95 percent CI, 1.405 to 22.603). There were no significant differences in nipple removal secondary to malposition or positive oncologic margins in patients with radiation compared to those without radiation. Patients with radiation did have a higher incidence of secondary procedures for capsular contracture (12.5 percent versus 2.3 percent; p < 0.001) and fat grafting (13.6 percent versus 3.9 percent; p < 0.001). The total nipple retention rate in patients with radiation therapy was 90 percent (79 of 88), and the reconstruction failure rate was 8 percent. Conclusions: Nipple-sparing mastectomy and immediate reconstruction in patients who had or will receive radiation therapy is associated with a higher incidence of complications and operative revisions compared with patients without radiation. However, most patients have successful reconstructions with nipple retention and no recurrences. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.