Soluble chitosan derivative treats wound infections and promotes wound healing in a novel MRSA-infected porcine partial-thickness burn wound model.

Burns are physically debilitating and potentially fatal injuries. The most common etiology of burn wound infections in the US is methicillin-resistant Staphylococcus aureus (MRSA), which is particularly recalcitrant when biofilms form. The current standard of care, silver sulfadiazine (SSD) is effective in reducing bacterial load, but less effective in improving burn wound healing. New treatments that can manage infection while simultaneously improving healing would provide a benefit in the treatment of burns. Porcine models are frequently used as a model for human wound healing but can be expensive due to the need to separate wounds to avoid cross contamination. The porcine model developed in this study offers the capability to study multiple partial thickness burn wound (PTBW) sites on a single animal with minimal crosstalk to study wound healing, infection, and inflammation. The current study evaluates a wound rinse and a wound gel formulated with a non-toxic, polycationic chitosan derivative that is hypothesized to manage infection while also promoting healing, providing a potential alternate to SSD. Studies in vitro and in this PTBW porcine model compare treatment with the chitosan derivative formulations to SSD. The wound rinse and wound gel are observed to disrupt mature MRSA biofilms in vitro and reduce the MRSA load in vivo when compared to that of the standard of care. In vivo data further show increased re-epithelialization and faster healing in burns treated with wound rinse/gel as compared to SSD. Taken together, the data demonstrate the potential of the wound rinse/gel to significantly enhance healing, promote re-epithelialization, and reduce bacterial burden in infected PTBW using an economical porcine model.

Galactorrhea After Nipple-Sparing Mastectomy: Case Report, Review of the Literature, and Algorithmic Approach to Management.

ABSTRACT: Nipple discharge is a rare but possible occurrence after nipple-sparing mastectomy (NSM). This study presents the first case of galactorrhea in a female patient after NSM. Although milky discharge due to physiologic lactation related to pregnancy is more common, galactorrhea is still possible and should be worked up appropriately to ensure that all breast tissue has been removed and that there are no other more worrisome causes.

Breast Reconstruction Using a Three-Dimensional Absorbable Mesh Scaffold and Autologous Fat Grafting: A Composite Strategy Based on Tissue-Engineering Principles.

Breast reconstruction remains an important field in plastic surgery, with most procedures using implants and/or autologous tissue. Few series report on experience with fat grafting as the primary form of breast reconstruction. The present article describes a new method of breast reconstruction using a three-dimensional absorbable mesh construct-or Lotus scaffold-and autologous fat grafting. A retrospective review was performed for all patients who underwent breast reconstruction using the Lotus scaffold and autologous fat grafting. Postoperative mammograms and magnetic resonance imaging scans were analyzed. Tissue specimens collected at subsequent procedures were harvested and stained with hematoxylin and eosin for histologic evaluation. Lastly, compression testing of the scaffold was performed using a tensiometer and digital tracking technology. Twenty-two patients underwent reconstruction of 28 breasts using the Lotus scaffold and autologous fat grafting between February of 2015 and February of 2018. Average follow-up was 19 months. All patients were satisfied with final breast shape and size. Mean patient age was 60.5 years and the average body mass index was 28 kg/m. Patients required on average two fat grafting sessions to achieve a successful result (range, zero to four). Postoperative mammography and magnetic resonance imaging showed robust adipose tissue in the breast with a slowly resorbing mesh and no oil cysts or calcifications. Histologic evaluation showed the presence of fat tissue around the scaffold and no evidence of capsule formation. Compression testing revealed the Lotus scaffold to be compliant with a high-resilience profile. The Lotus scaffold with autologous fat grafting is a viable method for breast reconstruction, giving the patient an autologous reconstruction with less morbidity compared to free tissue transfer. CLINICAL QUESTION/LEVEL OF EVIDENCE:: Therapeutic, IV.

Clinical Evaluation of an Off-the-Shelf Allogeneic Adipose Matrix for Soft Tissue Reconstruction.

Biomaterials derived from human adipose extracellular matrix have shown promise in vitro and in animal studies as an off-the-shelf adipogenic matrix for sustained volume replacement. Herein, we report the results of a randomized prospective study conducted with allograft adipose matrix (AAM) grafted into the pannus of presurgical abdominoplasty patients 3 or 6 months before scheduled surgery. This is the first report of a longitudinal histologic analysis of AAM in clinical use. METHODS: Ten healthy patients undergoing elective abdominoplasty were recruited to receive AAM before surgery. Enrolled subjects were randomized into either a 3-month follow-up cohort or a 6-month follow-up cohort. Subjects were monitored for adverse events associated with AAM grafting in addition to undergoing serial biopsy. Following surgical excision of the pannus, representative samples from the AAM surgical sites were stained and evaluated with hematoxylin and eosin for tissue morphology, Masson's trichrome for collagen, and perilipin for adipocytes. RESULTS: All subjects tolerated AAM with no severe adverse events reported. At 3 months following implantation, AAM remained visible within the confines of the subjects' native surrounding adipose tissue with sparse adipocytes apparent within the matrix. By 6 months, AAM had remodeled and was primarily composed of perilipin-positive adipocytes. Histologic analysis confirmed tissue remodeling (hematoxylin and eosin), adipogenesis (perilipin), and angiogenesis (Masson's trichrome) occurred with the presence of AAM. CONCLUSIONS: AAM is a safe, allogeneic, off-the-shelf regenerative matrix that is adipogenic and noninflammatory and promotes angiogenesis.

Adipose-derived stem cells delay muscle atrophy after peripheral nerve injury in the rodent model.

INTRODUCTION: Injuries to peripheral nerves cause distal muscle atrophy. The effects of adipose-derived stem cell (ASC) injections into a muscle after injury were examined. METHODS: A 1.5 cm defect in the rat sciatic nerve was created, resulting in gastrocnemius muscle atrophy. The nerve defect was repaired with autograft; DiR-labeled ASCs were injected into the gastrocnemius immediately postoperatively. Quantitation of gross musculature and muscle fiber area, cell survival, fibrosis, lipid deposition, inflammation, and reconstructive responses were investigated. RESULTS: ASCs were identified in the muscle at 6 weeks, where injections showed increased muscle mass percentage retained, larger average fiber area, and less overall lipid content accumulated throughout the musculature. Muscles having received ASCs showed increased presence of interlukin-10 and Ki67, and decreased inducible nitric oxide synthase (iNOS). DISCUSSION: This investigation is suggestive that an ASC injection into denervated muscle post-operatively is able to delay the onset of atrophy. Muscle Nerve 59:603-603, 2019.

Pediatric Upper Extremity Replantation: Courage in the Face of a Life-altering Injury.

BACKGROUND: Pediatric plastic surgeons perform reconstructive surgeries for various congenital, oncologic, and traumatic injuries. METHODS: Our Children's Hospital of Pittsburgh of University of Pittsburgh Medical Center (UPMC) Plastic Surgery team was tasked to care for a young man who suffered a proximal humeral amputation of his dominant upper extremity. RESULTS: A multidisciplinary team collaborated throughout his entire acute care and postoperative course, guiding treatment and care in effort to maximize function of his replanted extremity. CONCLUSIONS: This case report details the patient's unique journey and highlights his determination and courage to return back to a normal life.

Lateral Branch of the Thoracodorsal Nerve (LaT Branch) Transfer for Biceps Reinnervation.

In cases of significant upper extremity trauma, the thoracodorsal nerve is a reliable secondary option for the restoration of elbow flexion. In all previous descriptions, however, the entire nerve is transferred. We describe a case utilizing the lateral thoracodorsal nerve (LaT) branch for biceps reinnervation with an associated cadaver study. Transfer of the LaT branch to the biceps branch was performed on a patient who had sustained a traumatic brachial plexus injury that left him without elbow flexion. Also, 4 cadavers (8 upper extremities) were dissected to identify the bifurcation of the thoracodorsal nerve and confirm the feasibility of transferring the LaT branch to the biceps motor branch. Axon counts of the thoracodorsal proper, LaT branch, musculocutaneous proper, and the biceps branch were also obtained. A bifurcation of the thoracodorsal nerve was present in all cadaver specimens, with an average distance of 7.5 cm (range, 6.2-9.8 cm) from the insertion of the latissimus dorsi muscle. Axon counts revealed a donor-to-recipient ratio of 0.85:1. Follow-up of our patient at 1 year showed improvement of elbow flexion manual muscle testing grade from 0 to 4/5. Furthermore, electromyography at 1 year confirmed biceps reinnervation and showed normal readings of the latissimus compared with preoperative electromyography. Transfer of the LaT branch is a viable and minimally morbid option for biceps reinnervation after traumatic branchial plexus injury. Further follow-up of our patient and larger prospective studies are needed to understand the true potential of this nerve transfer.

Lateral thigh perforator flap for breast reconstruction: Computed tomographic angiography analysis and clinical series.

PURPOSE: Although abdominal-based flaps remain the first choice for autologous breast reconstruction, alternative donor sites are necessary when the abdomen is unavailable. Abdominal donor site suitability is determined, at times, according to deep inferior epigastric perforator (DIEP)-protocol computed tomographic angiography (CTA) results. CTA provides information about the pelvis/upper thigh that can be used to evaluate the suitability of other donor sites. This study aimed to examine the utility of DIEP-protocol CTA in the assessment of a lateral thigh perforator (LTP) flap. Furthermore, a small clinical LTP flap breast reconstruction series was presented. METHODS: The LTP flap anatomy was studied in 100 DIEP-protocol CT angiographies (200 thighs). Collected data included lateral circumflex femoral artery (LCFA) origin; number, type, and course of LTPs; pedicle characteristics; and reference point measurements. Relative relationships between reference point anatomy and perforator anatomy were analyzed. RESULTS: Perforators originated from the LCFA ascending branch (4.6 mm average diameter), averaging 2.6 perforators/thigh. The mean estimated pedicle length was 7.7 cm (±0.7 cm). Septocutaneous perforators were present in 97% (1.8 perforators/thigh). Musculocutaneous perforators were present in 64% (0.9 perforators/thigh). The mean distance between anterior superior iliac spine and perforator was 9.9 cm (±1.5 cm). Perforators were located 0.13 cm (±1.1 cm) below the pubic symphysis. Our LTP flap clinical series featured dissection in the supine position and primary donor site closure and highlighted the difficulty in flap design (six patients, nine LTP flaps). CONCLUSIONS: LTPs are consistent, reliably present, and radiographically appear to be suitable for microsurgical transfer. DIEP-protocol CTA is an acceptable method for imaging the pertinent LTP anatomy.