Prevention and Management of Wound Infections in Burn Patients.

The leading cause of morbidity in burn patients is infection with pneumonia, urinary tract infection, cellulitis, and wound infection being the most common cause. High mortality is due to the immunocompromised status of patients and abundance of multidrug-resistant organisms in burn units. Despite the criteria set forth by American Association of Burn, the diagnosis and treatment of burn infections are not always straightforward. Topical antimicrobials, isolation, hygiene, and personal protective equipment are common preventive measures. Additionally medical and nutritional optimization of the patients is crucial to reverse the immunocompromised status triggered by burn injury.

Challenges in the Management of Large Burns.

Large burns provoke profound pathophysiological changes. Survival rates of patients with large burns have improved significantly with the advancement of critical care and adaptation of early excision protocols. Nevertheless, care of large burn wounds remains challenging secondary to limited donor sites, prolonged time to wound closure, and immunosuppression. The development of skin substitutes and new grafting techniques decreased time to wound closure. Individually, these methods have limited success, but a combination of them may yield more successful outcomes. Early identification of patients with likely poor prognosis should prompt goals of care discussion and involvement of a palliative care team when possible.

Increasing Incidence of Sternoclavicular Joint Infections in Intravenous Drug Users.

Sternoclavicular joint septic arthritis is rarely seen in the general population. The majority of cases are seen in intravenous drug users. Given the lack of reported cases in the literature, there is no standardized treatment algorithm for this disease. Described treatment methods range from medical management to wide local debridement. The incidence of sternoclavicular joint septic arthritis will likely continue to increase with rising usage of intravenous drugs in the United States. Within the past year, our institution treated four cases.

Surgical Management of Pediatric Hidradenitis Suppurativa: A Case Series and Review of the Literature.

BACKGROUND: Hidradenitis suppurativa (HS) is a chronic and physically debilitating condition. Achieving long-term remission is difficult and sometimes remains elusive despite use of multiple pharmacological agents. However, surgery remains underused in the pediatric population. METHODS: We conducted a retrospective review for a 10-year period of all patients younger than 18 years who had undergone surgery for HS at a tertiary university hospital. In addition, we performed a literature review for English language articles related to the surgical management of pediatric HS patients. RESULTS: Eleven patients with a total of 23 operative sites were included in the study. The cohort was predominantly female (10:1) with an average age of 15.4 years and mean body mass index 31.9 kg/m. Lesion size ranged from 12.6 to 400 cm. Overall complication rate was 87% with a 7% reoperation rate to manage complications. Remission was achieved after a single procedure in 57% of sites. Three articles met our inclusion criteria for the literature review. CONCLUSIONS: Our article adds to the sparse literature and represents the largest study on surgical management of pediatric HS patients. Although surgery is not without its challenges, it presents a safe option and for pediatric HS patients with extensive scar or sinus tract formation.

Intraoperative Fragmentation and Retention of Endovascular Devices: Clinical Consequences and Preventative Strategies.

BACKGROUND: Expanded applications and increasing volumes of complex endovascular procedures have increased the risk of unintended intraoperative fragmentation and retention of catheters and sheaths. We describe a series of retained or fragmented endovascular devices, a quality improvement program to address this unmet need for improved detection of catheter fragmentation, and the results of this program. METHODS: Cases utilizing endovascular devices that resulted in a retained catheter fragment were identified and analyzed during divisional quality improvement review. One consistent area of concern was operating room (OR) staff unfamiliarity with verifying the integrity of an endovascular device. In response, a slide-based training protocol of focused, endovascular nursing education was implemented. Following perceived lack of improvement after this approach, we developed a handheld visual reference display of the tips of common catheters and sheaths. Staff was surveyed before and after intervention to assess the educational value of the display and the impact on staff device familiarity. RESULTS: All 4 described cases resulted in an unplanned return to the OR for retrieval of the fragmented catheter or sheath. No thromboembolic complications were observed, although associated intra-arterial thrombus was noted in 2 cases. Thirty-four OR nurses were polled to trial the visual reference display initiative, with 70% of those reporting primary surgical assignments outside of cardiovascular ORs. Introduction of the new visual reference display improved staff confidence in their ability to identify a broken device (2.4-3.7, P < .001). This improvement was most significant in OR staff with primary assignments in noncardiovascular services. CONCLUSION: Current OR standard operating procedures fail to address the potential for unintentionally retained catheters and wires during endovascular procedures. Our novel visual reference display of common endovascular items rather than conventional in-service training improved the ability of staff to identify device fragmentation at the time of the index procedure.

Comparison of wound strength, histologic, and aesthetic outcomes after microsurgical versus conventional skin closure in a rat model.

The purpose of this study was to compare the healing, strength, and cosmetic outcome of linear incisions after repair with the naked eye, surgical loupes, or a surgical microscope. Two parallel incisions were made on the dorsal skin of Sprague-Dawley rats (n = 36) and the rats randomized into four groups. A single surgeon repaired the incisions using 5-0 poliglecaprone in a running subcuticular pattern using the naked eye (Group I), surgical loupes with 2.5× magnification (Group II), surgical microscope with 5-10× magnification (Group III), and 6-0 poliglecaprone with a surgical microscope (Group IV). Rats were sacrificed at 1, 3, and 6 weeks. At each time point, the tensile strength of each closure was assessed. Macroscopic outcomes were evaluated using the Vancouver Scar Scale (VSS) and histology assessed by a blinded observer. Microscope closure took significantly longer than closure with the naked eye (p < 0.05). There was no significant difference in tensile strength or VSS ratings between the closure methods at any of the time points. On histopathologic analysis, there were a greater number of inflammatory cells and fibroblasts in the 6-0 microscope closure group versus the naked eye closure group at week 3 (p ≤ 0.05). In conclusion, wound repair under magnification did not yield a significant difference in cosmesis or wound tensile strength, but did increase operative time. Moreover, there was a trend toward increased inflammation with microscope-assisted closures, perhaps due to the increased suture burden.

Review of the Pathways Involved in the Osteogenic Differentiation of Adipose-Derived Stem Cells.

Grafts and prosthetic materials used for the repair of bone defects are often accompanied by comorbidity and rejection. Therefore, there is an immense need for novel approaches to combating the issues surrounding such defects. Because of their accessibility, substantial proportion, and osteogenic differentiation potential, adipose-derived stem cells (ASCs) make for an ideal source of bone tissue in regenerative medicine. However, efficient induction of ASCs toward an osteoblastic lineage in vivo is met with challenges, and many signaling pathways must come together to secure osteoblastogenesis. Among them are bone morphogenic protein, wingless-related integration site protein, Notch, Hedgehog, fibroblast growth factor, vascular endothelial growth factor, and extracellular regulated-signal kinase. The goal of this literature review is to conglomerate the present research on these pathways to formulate a better understanding of how ASCs are most effectively transformed into bone in the context of tissue engineering.

A Unique Bailout Method for the Repair of Abdominal Aortic Aneurism with a Narrow Iliac Bifurcation.

BACKGROUND: Endovascular aneurysm repair (EVAR) became the procedure of first choice for the repair of the abdominal aortic aneurysms (AAAs) in the last decades. However, narrow distal aorta remains to be the main limiting factor for the use of EVAR. A limited number of bail-out procedures have been described in the literature to overcome this problem. METHODS: A 69-year-old male was transferred to our institution for the repair of a ruptured AAA. His initial presentation mimicked an acute coronary syndrome, provoking a cardiac catheterization that documented a ruptured AAA. RESULTS: The patient was brought to the operating room for EVAR, but his distal aorta was severely narrowed, preventing the use of a bifurcated graft. We had to convert the bifurcated graft to a unigraft and place two additional grafts extending into the iliac arteries to fix the type I endoleak that we encountered at the distal end of the unigraft. He recovered well postoperatively, and his repair was found to be stable at 6-month follow-up. CONCLUSION: The surgical technique that we are presenting here is a unique bail-out procedure that can be used as an alternative solution to the narrow distal aortas.

Differences in Complication Rates of Gluteoplasty Procedures That Utilize Autologous Fat Grafting, Implants, or Local Flaps.

BACKGROUND: Gluteoplasty (gluteal augmentation) procedures are increasing in popularity, but there is not a universally accepted technique to produce optimal outcomes while minimizing risk. In this systematic review, we perform a meta-analysis to evaluate rates of complication from autologous fat grafting, implants, and local flaps, which are the three most common gluteoplasty operations. METHODS: A search of the PubMed/MEDLINE database for articles including the terms "gluteoplasty" OR "gluteal augmentation" OR "buttock augmentation" OR "Brazilian butt lift" OR "gluteal autologous fat graft" OR "buttock autologous fat graft" OR "gluteal implant" OR "buttock implant" OR "gluteal flap" OR "buttock flap" generated 229 articles. This number was brought down to 134 after initial screening by title. Inclusion criteria then removed those not written in English, those without access to the full text, those without extractable data on complications, and duplicates, leaving 46 articles to examine. RESULTS: A total of 4362 patients who underwent gluteoplasty between 1992 and 2017 were found. The overall complication rate was 12.4%. Implants had the highest rate (31.4%), whereas fat grafting had the lowest (6.8%); flaps were intermediate (23.1%). A χ test yielded a statistically significant (P < 0.001) nonindependent relationship between combined complication rate and type of surgery. Individual complications, such as asymmetry, capsular contracture, fat embolism, hematoma, infection, necrosis, pain, seroma, wide scar formation, and wound dehiscence, were also analyzed. CONCLUSIONS: Fat grafting by plastic surgeons might be the best option for gluteoplasty with regard to complications. In certain cases, however, there may only exist one choice for an operation because of anatomical limitations, which predisposes patients to those associated complications.

Cell-secreted extracellular matrix, independent of cell source, promotes the osteogenic differentiation of human stromal vascular fraction.

Lipoaspirates contain a readily accessible heterogeneous cell source for use in bone regeneration collectively referred to as the stromal vascular fraction (SVF). However, the osteogenic potential of SVF is inferior to other progenitor cell populations, thereby requiring alternative strategies to potentiate its effective use in cell-based therapies of bone repair. Cell-secreted extracellular matrix (ECM) is a promising substrate to guide cell phenotype or for use in biomaterial design, yet the instructional capacity of ECMs produced by various cell types is unknown. To determine whether the bioactivity of cell-secreted ECM was dependent on cell source, we assessed the osteogenic response of human SVF on ECMs secreted by bone marrow-derived mesenchymal stem cells (MSCs), adipose stromal cells (ASCs), and human dermal fibroblasts (HDFs). Tissue culture plastic (TCP), type I collagen, and ECM induced expression of integrin subunits α2, α5, and ß1 in SVF, yet seeding efficiency was only improved on MSC-derived ECM. Regardless of ECM source, SVF deposited over 8- and 1.3-fold more calcium compared to TCP and collagen-coated controls, respectively. Flow cytometry confirmed that SVF cultured on ECM retained CD31 and CD34 positive cell populations better than TCP. After depleting accessory cells, ASCs deposited significantly less calcium compared to donor-matched SVF. This function was partially restored in the presence of MSC-derived ECM when donor-matched endothelial cells (ECs) were added in an ASC/EC co-culture, confirming a role for ECs in osteogenic differentiation. These findings support the use of cell-derived ECM as a means to promote cell retention and osteogenic differentiation of SVF.

Negative Pressure Wound Therapy with Instillation and Dwell Time in the Surgical Management of Severe Hidradenitis Suppurativa.

BACKGROUND: Hidradenitis suppurativa (HS) is a physically debilitating disease that greatly impairs the quality of life of affected individuals. Advanced disease is often difficult to treat with topical and systemic therapies. Surgical resection of diseased skin has become paramount in HS management but proposes challenges of wound care and closure. METHODS: Four patients with a total of 12 complex wounds were treated over a three year period. All of the patients were males between the ages of 28 and 61 years. The lesions were located on the buttocks (n=5), chest (n=1), perianal (n=2), perineal (n=2), and axillary regions (n=2). A protocol of wide local excision, followed by negative pressure wound therapy with instillation and dwell time (NPWTi-d) to decrease bioburden and promote angiogenesis of the exposed base, and subsequent skin grafting was used. Patients remained hospitalized between procedures. RESULTS: The original wound area ranged from 210-540 cm2. Skin grafts of comparable sizes were taken from donor sites. The average duration of NPWTi-d placement was 3.5 days and the average time from excision to wound coverage was 4.3 days. The percent of graft uptake ranged from 70%-90%. All patients were resolved of their local disease with no complications. CONCLUSIONS: Surgical management of HS can be complicated by difficult closures. This case series demonstrates that wide local excision followed by NPWTi-d and skin grafting is able to achieve local resolution of disease in HS patients who have failed multiple minimally invasive therapies.

Fat Graft Safety after Oncologic Surgery: Addressing the Contradiction between In Vitro and Clinical Studies.

BACKGROUND: The authors investigate the in vitro and in vivo interaction of human breast cancer cells and human adipose-derived stem cells to address the controversy on the safety of postmastectomy fat grafting. METHODS: The authors co-cultured human adipose-derived stem cells and MDA-MB-231 breast cancer cells in an in vitro cell migration assay to examine the migration of breast cancer cells. In the in vivo arm, the authors injected breast cancer cells (group I), human breast cancer cells plus human adipose-derived stem cells (group II), human breast cancer cells plus human fat graft (group III), and human breast cancer cells plus human fat graft plus human adipose-derived stem cells (group IV) to the mammary fat pads of female nude mice (n = 20). The authors examined the tumors, livers, and lungs histologically after 2 weeks. RESULTS: Migration of breast cancer cells increased significantly when co-cultured with adipose-derived stem cells (p < 0.05). The tumor growth rate in group IV was significantly higher than in groups I and II (p < 0.05). The tumor growth rate in group III was also higher than in groups I and II, but this difference was not statistically significant (p > 0.05). Histologically, there was no liver/lung metastasis at the end of 2 weeks. The vascular density in the tumors from group IV was significantly higher than in other groups (p < 0.01). CONCLUSION: The injection of breast cancer cells, fat graft, and adipose-derived stem cells together increases breast cancer xenograft growth rates significantly.

The Effects of Adipose-Derived Stem Cells Differentiated Into Endothelial Cells and Osteoblasts on Healing of Critical Size Calvarial Defects.

Delayed vascularization and resultant resorption limits the clinical use of tissue engineered bony constructs. The objective of this study is to develop a strategy to accelerate the neovascularization of tissue-engineered bony constructs using endothelial differentiated adipose-derived stem cells (ASC). The authors harvested ASC from inguinal fat pads of male Lewis rats (n = 5) and induced toward endothelial and osteoblastic lineages. The authors created critical size calvarial defects on male Lewis rats (n = 30) and randomized the animals into 4 groups. For the repair of the defects the authors used hydroxyapatite/poly(lactide-co-glycolide) [HA-PLG] scaffolds in group I, HA-PLG scaffolds seeded with ASC in group II, HA-PLG scaffolds seeded with ASC-derived endothelial cells in group III, and HA-PLG scaffolds seeded with ASC-derived osteoblasts in group IV. The authors evaluated the bone healing histologically and with micro-computed tomography (CT) scans 8 weeks later. Adipose-derived stem cells exhibited the characteristics of endothelial and osteogenic lineages, and attached on HA-PLG scaffolds after differentiation. Micro-CT analysis revealed that highest bone mineral density was in group IV (1.46 ± 0.01 g/cm) followed by groups III (1.43 ± 0.05 g/cm), I (1.42 ± 0.05 g/cm), and II (1.3 ± 0.1 g/cm). Hematoxylin-Eosin and Masson Trichrome staining revealed similar results with the highest bone regeneration in group IV followed by groups II, III, and I. Regenerated bone in group IV also had the highest vascular density, but none of these differences achieved statistical significance (P > 0.05). The ASC-derived endothelial cells and osteoblasts provide a limited increase in calvarial bone healing when combined with HA-PLG scaffolds.

A comparison of rat degloving injury models.

OBJECTIVE: Two different rat models for degloving injury were described in the literature. Our aim in this study is to compare these rat models to determine which one is more reliable and reproducible. METHODS: We surgically induced degloving injury on tails and left hindlimbs of Wistar albino rats (n = 8), and sutured the avulsed tissues back in their original positions after a waiting period. We observed the changes in the avulsed flaps every other day for 10 days. At the end of follow-up period we evaluated the lesions in avulsed flaps by macroscopic measurement of necrosis and histological ulcer scoring using the National Pressure Ulcer Advisory Panel (NPUAP) Scale. RESULTS: The average length of necrosis in avulsed tail flaps was 28.42 ± 3.04 mm, whereas there was no necrosis in avulsed hindlimb flaps (p < 0.05). The average ulcer score of the lesions in tail and left hindlimb were 3.42 ± 0.78, and 1.28 ± 0.48, respectively (p < 0.05). Despite the lack of visible necrosis TUNEL staining revealed an increased amount of apoptotic cells in avulsed hindlimb flaps. Literature review revealed a significant variability in previous studies in terms of the amount of necrosis observed in tail degloving injury model. CONCLUSION: Tail degloving injury model proved to be a more reliable animal model for degloving injuries. However, standardization of the magnitude of degloving force is required to decrease the variability of necrosis observed in the literature.

Comparison of two cadaveric acellular dermal matrices for immediate breast reconstruction: A prospective randomized trial.

AlloDerm RTU® and AlloMaxTM are two acellular dermal matrices (ADMs) used in implant-based breast reconstruction. In this study, we examined whether different processing methods for the ADMs lead to a disparity in histologic, clinical, and financial outcomes after breast reconstruction. Thirty patients undergoing implant-based breast reconstruction were randomized into AlloMax or AlloDerm arms (n = 15, each). ADM was placed at the time of immediate reconstruction. Patients were evaluated for complications on postoperative days 7, 14, and 30. During implant exchange, ADM biopsies were taken and compared histologically for vascular and cellular infiltration. Patient satisfaction was evaluated using the BRECON-31 questionnaire 1 year after implant exchange. A cost analysis was performed comparing the two ADMs. Patient demographics and complication rates were similar between the two groups (p > 0.05). Histologically, vessel density and fibroblast/inflammatory cell infiltrate were greater on the dermal side than on the implant side (p < 0.01) in both ADMs, suggesting greater vascular and cellular in-growth from the dermal side. Vessel density in the middle portion of the Allomax biopsies was significantly higher than the same site in the Alloderm biopsies (p < 0.05). The extent of fibroblast/inflammatory cell infiltration was similar in both arms (p > 0.05). The BRECON-31 satisfaction questionnaire yielded similar responses across all metrics between the two study arms. The negotiated price was slightly different when comparing the two ADMs, with no significant difference in ADM reimbursement. In this study, AlloDerm RTU and AlloMax were successfully used for implant-based breast reconstruction with comparable outcomes.

Intraoperative Placement of Pectoral Nerve Block Catheters: Description of a Novel Technique and Review of the Literature.

Regional and neuraxial anesthesia for pain management after breast surgery is not widely used despite data showing improved postoperative pain control and patient satisfaction scores. We report a case of a 61-year-old woman who underwent bilateral mastectomies, and received postoperative analgesia via pectoral nerves 1 and 2 nerve blocks. This case highlights a previously undescribed technique of prolonged postoperative pain control by intraoperative placement of pectoral nerves 1 and 2 regional anesthesia catheters under direct visualization. Intraoperative placement has the potential benefits of more accurate plane targeting, time saving, and widening the scope of use to practitioners are not trained in the ultrasound guided technique. We also present a review of the regional block techniques and present a preliminary algorithm for the selection of block method in breast surgery.

Comparison of Endothelial Differentiation Capacities of Human and Rat Adipose-Derived Stem Cells.

BACKGROUND: The authors compared the endothelial differentiation capacities of human and rat adipose-derived stem cells to determine whether human adipose-derived stem cells can be a source of endothelial cells clinically. METHODS: Human and rat adipose-derived stem cells were harvested and characterized with flow cytometry and trilineage differentiation. Cells from passages III through V were fed with endothelial cell differentiation medium for up to 3 weeks. Cells were harvested after 1, 2, and 3 weeks, and endothelial differentiation was evaluated with quantitative reverse-transcriptase polymerase chain reaction, flow cytometry, and angiogenic sprouting assays. RESULTS: Both human and rat adipose-derived stem cells were CD90, CD44, and CD31 before differentiation. The cells were successfully differentiated into adipogenic, osteogenic, and chondrogenic lineages. Expression of endothelial cell-specific genes peaked at the second week of differentiation in both human and rat cells. The fold changes in expression of CD31, vascular endothelial growth factor receptor-1, nitric oxide synthase, and von Willebrand factor genes at week 2 were 0.4 ± 0.1, 34.7 ± 0.3, 2.03 ± 0.25, and 12.5 ± 0.3 respectively, in human adipose-derived stem cells; and 1.5 ± 1.01, 21.6 ± 1.7, 17.9 ± 0.6, and 11.2 ± 1.3, respectively, in rat cells. The percentages of CD31 cells were 0.2, 0.64, and 1.6 in human cell populations and 0.5, 5.91, and 11.5 in rat cell populations at weeks 1, 2, and 3, respectively. Rat adipose-derived stem cell-derived endothelial cells displayed enhanced sprouting capability compared with the human cells. CONCLUSIONS: Human adipose-derived stem cells responded less strongly to EGM-2MV endothelial differentiation medium than did the rat cells. Still, the human cells have the potential to become a clinical source of endothelial cells with modifications in the differentiation conditions.

Developing a Nanoparticle-Delivered High-Efficacy Treatment for Infantile Hemangiomas Using a Mouse Hemangioendothelioma Model.

BACKGROUND: Current treatments for infantile hemangiomas have unpredictable outcomes. The authors' aim was to develop a nanoporphyrin-delivered, high-efficacy treatment for infantile hemangiomas using a mouse hemangioendothelioma model. METHODS: The authors injected mouse hemangioendothelioma cells intradermally to axillary regions of 5-week-old, female, nude mice (n = 19) to induce hemangioendothelioma growth. They documented nanoporphyrin accumulation in hemangioendotheliomas using positron emission tomography. For the treatment study, the authors randomized hemangioendothelioma-bearing nude mice (n = 9) into three groups (n = 3 each). Group I received only saline injections. Group II received only laser treatment after saline injection, and group III received laser treatment after nanoporphyrin injection through the tail vein. The authors followed up the treatment response with digital caliper measurements. RESULTS: Hemangioendotheliomas started to grow approximately 1 week after inoculation and resembled infantile hemangiomas histologically. Nanoporphyrin uptake in hemangioendotheliomas was 19.7 ± 2.2, 16.7 ± 2.02, 8.4 ± 0.3, and 4.9 ± 0.6 percent injected dose per gram of tissue at 3, 6, 24, and 48 hours after injection, respectively. Nanoporphyrin uptake was significantly higher than in blood at 24 and 48 hours after injection (p < 0.05). Results of ex vivo biodistribution study were consistent with positron emission tomographic imaging. Hemangioendotheliomas in group III started to regress 1 day after the treatment and disappeared totally by day 21. The difference between tumor volumes in group III and other groups was significant on days 17 and 21 (p < 0.05). CONCLUSIONS: Nanoporphyrin accumulated in hemangioendotheliomas at high concentrations, enabling a high-efficacy photodynamic therapy. Given the similarities between hemangioendotheliomas and infantile hemangiomas, this treatment potentially can be a high-efficacy treatment for infantile hemangiomas.