The study of cytokine dynamics at the operation site after mastectomy

Adipose derived stem cell extracellular vesicles modulate primary human macrophages to an anti-inflammatory phenotype in vitro

EVs released by adipose derived stem cells (ADSCs) have shown promise as a therapeutic for tissue repair because of their purported immune-regulatory properties. Extracellular vesicles (EVs) from ADSCs could be beneficial in improving graft retention rates for autologous fat grafting (AFG) post-mastectomy as, currently, grafted tissue rates are variable. Enriching grafted tissue with ADSC-EVs may improve retention rates by modulating macrophages resident within both the breast and lipoaspirate. We aimed to identify key macrophage phenotypes that are modulated by ADSC-EVs in vitro. ADSCs were isolated from lipoaspirates of women undergoing AFG and characterised by flow cytometry and differentiation potential. ADSC-EVs were isolated from culture media and characterised by tuneable resistive pulse sensing, transmission electron microscopy and Western blot. Primary monocyte-derived macrophages were polarized to an M1-like (GM-CSF, IFNγ), M2-like phenotype (M-CSF, IL-4) or maintained (M0-like; M-CSF) and ADSC-EVs were co-cultured with macrophages for 48 h. Flow cytometry and high-dimensional analysis clustered macrophages post co-culture. A manual gating strategy was generated to recapitulate these clusters and was applied to a repeat experimental run. Both runs were analysed to examine the prevalence of each cluster, representing a unique macrophage phenotype, with and without ADSC-EVs. Following the addition of ADSC-EVs, M0-like macrophages demonstrated a reciprocal shift of cell distribution from a cluster with a 'high inflammatory profile' (CD36+++CD206+++CD86+++; 16.5 ± 7.0%; p < 0.0001) to a cluster with a 'lower inflammatory profile' (CD36+CD206+CD86+; 35  ± 21.5%; p < 0.05). M1-like macrophages shifted from a cluster with a 'high inflammatory profile' (CD206++CD11b++CD36++CD163++; 26.1 ± 9.4%; p = 0.0024) to a 'lower inflammatory profile' (CD206+CD11b+CD36+CD163+; 72.8  ± 8.7%; p = 0.0007). There was no shift in M2-like clusters following ADSC-EV treatment. ADSC-EVs are complex regulators of macrophage phenotype that can shift macrophages away from a heightened pro-inflammatory state.

High-dose Irradiation Stimulated Breast Tumor Microenvironment to Enhance Tumor Cell Growth and Decrease Tumor Cell Motility

Background

Surgery and radiotherapy are two main modalities of breast cancer treatment. However, surgery affects the tumor microenvironment negatively and promotes the growth of possible malignant cells remaining in the tumor bed.

Objective

The present study aimed to investigate the effects of intraoperative radiotherapy (IORT) on the tumor microenvironment. Therefore, the effect of surgical wound fluid (WF), collected from operated and irradiated patients on the growth and motility of a breast cancer cell line (MCF-7) was assessed.

Material and Methods

In this experimental study, preoperative blood serum (PS) and secreted WF from 18 patients who underwent breast-conserving surgery (IORT-) and 19 patients who received IORT following surgery (IORT+) were collected. The samples were purified and added to MCF-7 cultures. Two groups of the cells were treated with and without fetal bovine serum (FBS) and used as positive and negative controls. Applying 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and scratch wound healing assays, the growth and motility of MCF-7 cells were measured.

Results

Cell growth of the cells receiving WF from IORT+ patients (WF+) was statistically higher than the corresponding values of the cells received PS or WF from IORT- patients (WF-) (P<0.01). Both WF+ and WF- decreased the cells' migration ability compared to PS (P<0.02) and FBS (P<0.002), although WF+ caused a more significant reduction (P<0.02).

Conclusion

Wound fluid extracted from breast cancer patients who underwent both surgery and IORT increased the growth of breast tumor cells, but decreased their ability to migrate.

Postoperative Fluid Collections in Total Joint Arthroplasty: A Narrative Review

A post-operative fluid collection (POFC) represents a common finding in both primary and revision total joint arthroplasty (TJA). Fortunately, most resolve on their own, but in instances where they become symptomatic, prompt identification and management are paramount, especially when they occur adjacent to a joint arthroplasty because of the increased the risk of developing a periprosthetic joint infection. A strong clinical suspicion with appropriate clinical exam is required along with select imaging modalities to arrive at a diagnosis. Meticulous surgical technique is crucial to prevent POFC, but new emerging treatments continue to evolve. This article presents an updated overview of incidence, pathophysiology, diagnosis, and management of POFC in the setting of TJA. We review the role of select imaging modalities as well as summarize current literature regarding new treatments such as sclerotherapy agents, acellular dermal matrices, and negative pressure wound therapy. Future studies are necessary to explore the interplay of inflammatory mediators in POFC formation and to define their role in fluid collection resolution.

Wound Closure Following Intervention for Closed Orthopedic Trauma

The method of skin closure and post-operative wound management has always been important in orthopedic surgery and plays an even larger role now that surgical site infection (SSI) is a national healthcare metric for both surgeons and hospitals. Wound related issues remain some of the most feared complications following orthopedic trauma procedures and are associated with significant morbidity. In order to minimize the risk of surgical site complications, surgeons must be familiar with the physiology of wound healing as well as the patient and surgical factors affecting healing potential. The goal of all skin closure techniques is to promote rapid healing with acceptable cosmesis, all while minimizing risk of infection and dehiscence. Knowledge of the types of closure material, techniques of wound closure, surgical dressings, negative pressure wound therapy, and other local modalities is important to optimize wound healing. There is no consensus in the literature as to which closure method is superior but the available data can be used to make informed choices. Although often left to less experienced members of the surgical team, the process of wound closure and dressing the wound should not be an afterthought, and instead must be part of the surgical plan. Wounds that are in direct communication with bony fractures are particularly at risk due to local tissue trauma, resultant swelling, hematoma formation, and injured vasculature.

Effect of quilting on seroma formation in mastectomies: A meta-analysis

BACKGROUND

Seroma is the most common complication following mastectomy and can require several days of drainage and lead to delayed wound healing, longer hospital stays, and an increased financial and emotional burden. Seroma formation is not well understood and but there is good evidence that closing the dead space via quilting can help reduce seroma formation. This study assessed randomized controlled trials and reviewed current literature to elucidate if there is a strong association between quilting sutures and seroma formation.

METHODS

A systematic search of 5 databases using search terms similar to "seroma", "quilting", "flap fixation", "random", and "mastectomy". Data was extracted and Medcalc software used to perform a meta-analysis of the primary outcome: incidence of seroma formation, as well as secondary outcomes: volume and duration of drainage.

RESULTS

Eleven randomized controlled trials with 2009 patients were included. Quilting with sutures greatly reduced the incidence of seroma formation compared with conventional closure (p < 0.001, RR 0.367 [95% CI 0.25, 0.539]; I² = 63.56%) as well as duration of drainage (p = 0.015, SMD -1.657, SE 0.680 [95% CI -2.991, -0.324]; 8 studies, n = 1578; I² = 98.98%). Quilting did not significantly affect volume of drainage.

CONCLUSIONS

Quilting was found to be associated with lower seroma rates. Future studies should investigate the use of quilting in combination with other preventative techniques to search for a synergistic method that will further improve patient care.

Low TGF-β1 in Wound Exudate Predicts Surgical Site Infection After Axillary Lymph Node Dissection

PURPOSE

Surgical site infection (SSI) after axillary lymph node dissection (ALND) for breast cancer increases morbidity and delays the onset of adjuvant treatment. Only a few studies have investigated the feasibility of wound exudate analysis in SSI prediction. This study assessed changes in cytokine levels in postsurgical wound exudate after ALND and examined their predictive value for the early diagnosis of SSI.

METHODS

An observational prospective pilot study was conducted in 47 patients with breast cancer undergoing ALND. Wound exudate samples were collected on the first and sixth postoperative days (POD). Interleukin (IL)-1α, IL-1β, IL-4, IL-10, IL-13, tumor necrosis factor alpha (TNF-α), transforming growth factor beta1 (TGF-β1) and vascular endothelial growth factor (VEGF) C and D levels were measured by immunoassay. Patients were followed to detect SSI.

RESULTS

SSI was diagnosed in 8/47 (17.0%) patients. Four SSI patients were hospitalized and treated with intravenous antibiotics. The concentration of TGF-β1 in wound exudate was significantly lower on POD#1 in the SSI group compared to the no SSI group (p=0.008). The receiving operator characteristics (ROC) curve for TGF-β1 showed an area under curve of 0.773 (p=0.0149) indicating good diagnostic potential. On POD#6, the concentration of TGF-β1 remained significantly lower (p=0.043) and the concentrations of IL-10 (p=0.000) and IL-1β (0.004) significantly higher in the SSI group compared to the no SSI group.

CONCLUSION

To our knowledge, this is the first study suggesting a predictive role of wound exudate TGF-β1 levels for SSI. Our results suggest that the risk for SSI can be detected already on POD#1 and that the assessment of TGF-β1 levels in the wound exudate after ALND can provide a usefull method for the early detection of SSI. The key findings of this pilot study warrant verification in a larger patient population.

Analysis of TNF-α and interleukin-6 in seroma of patients undergoing mastectomy with or without flap fixation: is there a predictive value for seroma formation and its sequelae?

BACKGROUND

Seroma formation is a common complication after mastectomy. Flap fixation has the potential to prevent seroma formation, but identifying patients that are at risk of developing seroma, remains challenging. The aim of this study was to assess the association between pro-inflammatory cytokines in seroma fluid one day after surgery and seroma formation and it sequelae.

METHODS

Patients undergoing mastectomy were randomized into one of three groups: no flap fixation, flap fixation using sutures or flap fixation using tissue glue. Seroma samples from 40 consecutive patients undergoing mastectomy were collected on the first postoperative day for analysis of interleukin-6 and tumor necrosis factor-α. Seroma formation and its sequelae were assessed in the outpatient clinic ten days, six weeks and three months after surgery.

RESULTS

TNF-α concentrations were not detectable in the seroma samples of any of the 40 patients. BMI (p = 0.001) and weight of the resected surgical specimen (p = 0.003) were associated with higher IL-6 levels in seroma on the first postoperative day after mastectomy. A higher seroma concentration of IL-6 was associated with significantly fewer patients with clinical seroma formation three months after surgery (p = 0.027).

CONCLUSION

IL-6 is associated with clinical seroma formation three months after surgery. There is however no evident association between IL-6 and complications related to seroma formation. Higher IL-6 levels are predictive of less long-term seroma formation. Application of flap fixation does not seem to influence the level of IL-6.

Examination of the Effects of Celecoxib on Postmastectomy Seroma and Wound Healing

Objectives:

To examine the effect of celecoxib on wound healing and development of seroma after mastectomy.

Seroma is an accumulation of serous fluid in dead space emerging after breast cancer surgery. The pathophysiology of seroma has not been clearly elucidated. Development of seroma leads to prolongation of hospital stay, increase in costs, ischemia of the flaps, infections due to fluid accumulation, and delayed adjuvant treatment.

Seroma is still a current problem, and the most common treatment method for this problem is drainage and repeated aspirations for 5–7 days after surgery.

Methods:

The effect of celecoxib whose anti-inflammatory, antiangiogenic, and antioxidant effectiveness has been demonstrated in a mastectomy model applied on female Wistar rats has been investigated in the present study. A total of 20 rats including 10 rats in the control and 10 in the celecoxib group were studied.

Intraperitoneal 0.25 cc/250 g (20 mg/kg/day) celecoxib was administered to the celecoxib group for 5 days after mastectomy, and the same volume of physiological saline solution was given to the control group for 5 days. Rats were followed up for 10 days after surgery. During this process, vitality of the rats, movements of the extremities, wound healing conditions, wound infections, flap necrosis, and occurrence of seroma were recorded. At the end of this period, seromas were aspirated, tissue samples were retrieved, and the rats were sacrificed. Fibrin, hemorrhage, edema, vascularization, congestion, polymorphonuclear leukocytes, and increase in fibrotic tissue fibroblasts, lymphocytes, and macrophages were evaluated in tissue samples.

In seroma fluids, interleukin-1 beta (IL-1β), an acute phase reactant, and vascular endothelial growth factor, a vital parameter of vascular proliferation and angiogenesis, were examined.

Results:

At the end of the experiments, the seroma volume decreased significantly in the celecoxib group (p=0.804; 0.001), the IL-1β level decreased significantly as detected in the biochemical examination (p=0.014), and in the histopathological examination, an increase in congestion in the celecoxib group was determined.

Conclusion:

In conclusion, celecoxib markedly decreased interleukin and the volume of seroma after mastectomy; suppressed the level of an acute phase reactant, IL-1β; and demonstrated this effect through its anti-inflammatory activity. We believe that the effects of celecoxib should be investigated using different dose applications and larger number of subjects.

Breast cancer recurrence after reconstruction: know thine enemy

Breast reconstruction proceeding cancer treatment carries risk, regardless of the type of surgery. From fat grafting, to flap placement, to implants, there is no guarantee that reconstruction will not stimulate breast cancer recurrence. Research in this field is clearly divided into two parts: scientific interventional studies and clinical retrospective evidence. The reconstructive procedure offers hypoxia, a wound microenvironment, bacterial load, adipose derived stem cells; agents shown experimentally to cause increased cancer cell activity. This is compelling scientific evidence which serves to bring uncertainty and fear to the reconstructive procedure. In the absence of clinical evidence, this laboratory literature landscape is now informing surgical choices. Curiously, clinical studies have not shown a clear link between breast cancer recurrence and reconstructive surgery. Where does that leave us? This review aims to analyze the science and the surgery, thereby understanding the oncological fear which accompanies breast cancer reconstruction.

Perceived Stress and Surgical Wound Cytokine Patterns

This was a pilot study to examine pre- and postoperative stress experienced by women who were undergoing autologous breast reconstruction and how stress might impact wound healing, specifically examining cytokines and other chemical mediators in the wound environment. A nonexperimental descriptive design over time was utilized. Participants were women who were undergoing autologous abdominal breast reconstruction for breast cancer (N = 20). Data were collected preoperatively and at 24, 48, 72, and 96 hr postsurgery. Complications were monitored intraoperatively and up to 30 days postsurgery. Psychological stress was measured with the 10-item Perceived Stress Scale (PSS), the Impact of Events Scale-Revised (IES-R), and a 100-mm Visual Analog Scale (VAS). Cytokines were assayed using the 27-plex kit with a Bio-Plex Plus. Although breast cancer is considered a stressor, in this sample of women, scores of the PSS, IES-R, and VAS showed that in fact these participants experienced low levels of psychological stress. All measured biochemical mediators in serum and wound fluid were detected and trends were identified. IL-1ra, IL-6, IL-8, G-CSF, IP-10, MCP-1, MIP-1β, RANTES, and VEGF were present in the highest concentrations. Significant changes in levels of cytokines in wound fluid were observed in IL-1β, IL-2, IL-5, IL-6, IL-8, IL-9, IL-10, IL-17, FGF-basic, G-CSF, MIP-1α, PDGF-bb, MIP-1β, RANTES, and TNF-α. The remaining cytokine concentrations stayed stable over time. These findings suggest that although these women were not experiencing high levels of stress, meaningful cytokine patterns were detected.

Seroma in Prosthetic Breast Reconstruction

BACKGROUND

Seroma, as a complication of prosthetic breast reconstruction, results in patient distress, increased office visits, undesirable aesthetic outcomes, and--importantly--may escalate to infection and frank prosthesis loss. Herein, the authors review the pathophysiology and risk factors and attempt to collate published practices for avoidance and management of seroma.

METHODS

A systematic literature review was performed using MEDLINE, Web of Science, Embase, and Cochrane Library for studies published between 2000 and January of 2015. Random-effects meta-analysis was used to estimate the overall pooled incidence of seroma and to examine the effect of drain number and acellular dermal matrix use.

RESULTS

Seventy-two relevant primary articles and three systematic reviews were identified. Fifty-one citations met inclusion criteria, including two randomized controlled trials. The overall pooled incidence was 5.4 percent (95 percent CI, 4.1 to 6.7 percent). Obesity, acellular dermal matrix, and preoperative irradiation were cited risk factors. Pooled relative risk for acellular dermal matrix was 1.83 (95 percent CI, 1.28 to 2.62). Drain practices were collated from 34 articles.

CONCLUSIONS

Seromas following prosthetic breast reconstruction are complicated by the hypovascular, proinflammatory milieu of the mastectomy skin flap, the geometrically complex dead space, and the presence of a foreign body with potential contamination and biofilm. There is reasonable evidence to suggest that these factors contribute to a progression of seroma to infection and prosthesis loss. These findings have motivated this summary article on current practice guidelines and strategies to prevent and treat seromas.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, II.

Update on Postsurgical Scar Management

Postoperative scar appearance is often a significant concern among patients, with many seeking advice from their surgeons regarding scar minimization. Numerous products are available that claim to decrease postoperative scar formation and improve wound healing. These products attempt to create an ideal environment for wound healing by targeting the three phases of wound healing: inflammation, proliferation, and remodeling. With that said, preoperative interventions, such as lifestyle modifications and optimization of medical comorbidities, and intraoperative interventions, such as adherence to meticulous operative techniques, are equally important for ideal scarring. In this article, the authors review the available options in postoperative scar management, addressing the benefits of multimodal perioperative intervention. Although numerous treatments exist, no single modality has been proven superior over others. Therefore, each patient should receive a personalized treatment regimen to optimize scar management.

Negative pressure wound therapy as an adjunct in healing of chronic wounds

Negative pressure wound therapy (NPWT) has emerged as a cutting-edge technology and provides an alternative solution to the problem of wounds. This study was undertaken to assess the efficacy of this technique in the treatment of chronic wounds. A prospective clinical study was used to evaluate our experience in use of NPWT in the healing of pressure ulcers and chronic wounds over 2 years. The primary end point of the study group was the time taken for appearance of healthy granulation tissue and full reepithelialisation without drainage. All patients with sepsis were excluded from the study. The statistical analysis of the data was carried out. Of the 60 patients studied, 41 had associated comorbidities including diabetes mellitus. The commonest site of occurrence was the lower limb. Coverage in the form of a flap was required at presentation in 63·33% of patients. However, after initiation of NPWT, none of them required the procedure and they healed spontaneously either by secondary intention or by skin grafting. The time taken for appearance of healthy granulation tissue was 14·36 ± 4·24 days. Complete healing of wounds occurred by 33·1 ± 10·22 days. There was a statistically significant difference in the volume of the wounds before and after the intervention (P = 0·000). Complications resulting from NPWT were minimal. This technique is an excellent adjunct to surgical debridement.

Tissue integration and inflammatory reaction in full-thickness abdominal wall repair using an innovative composite mesh

PURPOSE

When composite meshes are used in abdominal wall repair, seroma formation may persist and delay the desired integration leading to recurrence. This study compares tissue integration and inflammatory response in abdominal wall repair with composites with different absorbable synthetic barriers.

METHODS

Full-thickness defects created in the abdominal wall of rabbits were repaired using polypropylene prosthesis or the following composites: Physiomesh™ (Phy); Ventralight™ (Vent) and "new composite mesh" (Ncm) not yet used clinically in humans. The collected seroma was evaluated for IFN-γ/IL-4 by ELISA. Tissue integration, anti- (IL-13/TGFβ-1/IL-10/IL-4) and pro-inflammatory (TNF-α/IL-6/IFN-γ/VEGF) cytokine mRNA expression and TGFβ/VEGF immunolabeling were evaluated at 14 and 90 days post-implant.

RESULTS

Seroma was observed in 10 of 12 Phy/Vent and 4 of 12 Ncm. Wound fluid IFN-γ showed a time-dependent significant increase in Vent and tendency to decrease in Ncm, while all composites exhibited IL-4 upward trend. Prostheses were fully infiltrated by an organized connective tissue at end time although the area had shown prior seroma. A stable mesothelium was developed, except in adhesion areas. Vent/Phy displayed a significant increase in TNF-α/IFN-γ-mRNA over time. Significant decrease in VEGF mRNA was observed in Phy/Ncm, while a significant increase of TGFβ-1 mRNA was evident in all composites over time. Ncm exhibited the highest TGFβ protein expression area at short term and the greatest percentage of VEGF positive vessels at end time.

CONCLUSION

Ncm could be an appropriate candidate to improve clinical outcome showing the lower development of seroma and optimal tissue integration with minimal pro-inflammatory cytokine response over time and consistent pro-wound healing cytokine expression.

The effects of resveratrol on flap survival in diabetic rats

Resveratrol is an antioxidant agent with multiple positive impacts on the body. It is known to have anti-diabetic, anti-inflammatory, anti-carcinogenic, and neuroprotective effects. The goal of this study is to demonstrate the antioxidant and anti-diabetic effects of resveratrol on flap survival in diabetic rats. Streptozotocin-induced diabetic Sprague-Dawley albino rats were treated with 10 mg/kg resveratrol following a flap surgery. Histological findings regarding polymorphonuclear leukocyte (PMNL) density, vascular proliferation, fibroblast density, and tissue necrosis were compared between resveratrol-treated and control rats. Significantly higher PMNL density was found in the control group (p = 0.005); while vascular proliferation and the fibroblast density were higher in the resveratrol group (p = 0.004 and p = 0.021, respectively). Collagen density was also higher in the resveratrol group and the difference has statistical significance (p = 0.024). Lymphocyte density was not significantly different between groups (p = 0.061). When the necrosis in the distal areas was evaluated histologically, 20% of the resveratrol group had epidermal tissue necrosis, thus 90% of the control group had epidermal or full-layer necrosis. Resveratrol improved flap survival significantly in diabetic rats. Therefore, diabetic patients requiring complex reconstructive procedures may benefit from resveratrol; so, clinical trials are required to support this study.

Impact of interfraction seroma collection on breast brachytherapy dosimetry - a mathematical model

Purpose

Balloon brachytherapy is a widely accepted modality for delivery of accelerated partial breast irradiation (APBI). Our hypothesis was that inter-fraction seroma collection around the balloon surface would have an adverse effect on dosimetry of the target.

Material and methods

This is a dosimetric re-planning study using two volumetric models (30 cc and 45 cc) in a Contura^® multi-lumen balloon (MLB) catheter. In a previously treated patient, two customized baseline plans were generated using multiple channels of the Contura^® catheter prescribed to the Planning Target Volume Evaluation (PTV_Eval). Symmetric expansions of 1.0 mm (0-9 mm) increments around the balloon surface were performed to simulate a “Virtual Seroma” (VS) accumulation for both balloon volumes and plans were obtained for each expansion using Eclipse Brachyvision™. An analysis of these plans was then performed to evaluate the effect of seroma accumulation on dosimetric parameters of V100 and V90.

Results

20 plans were generated and analyzed (10 plans for each balloon volume), representing VS of 6.0-66.0 cc. There was a commensurate decrease in the dose delivered to the PTV_Eval V100 and V90 (as defined by the original treatment plan) with increasing VS accumulation leading to a sub-optimal coverage of the PTV_Eval. For 30 cc MLB catheter, V100 decreased by 1.4% and V90 decreased by 0.9% for every 1 cc of VS. For 45cc MLB catheter, V100 decreased by 1.3% and V90 decreased by 1.15% for every 1.0 cc accumulation of VS.

Conclusions

Balloon catheter-tissue adherence ensures daily dose delivery to the planned PTV_Eval. Accumulation of seroma, hematoma or air between HDR fractions can significantly impact PTV_Eval dosimetry. Vacuum-port aspiration prior to delivery of each fraction, if available, should be considered to minimize the risk of geographic under dosing.

Superficial wound swabbing: a novel method of sampling and processing wound fluid for subsequent immunoassay analysis in diabetic foot ulcerations

OBJECTIVE

In diabetic foot ulcers, wound fluid inflammatory mediators have previously been proposed as surrogate markers for nonhealing. However, currently available wound fluid sampling techniques are not suitable for clinical practice due to low levels of exudate and a high logistical effort. The aim of this investigation was to assess 1) the technique of superficial wound swabbing for harvesting wound fluid; and 2) the quality of the collected fluid for immunoassay analysis of inflammatory mediators.

RESEARCH DESIGN AND METHODS

Both nylon-flocked swabs and film dressings were used to collect wound fluid from foot ulcers of diabetic patients. In randomly selected patients, levels of wound fluid inflammatory mediators and matrix metalloproteases were determined using multiplexed bead-based sandwich immunoassays with respect to both sampling methods. Wound fluid spike-in experiments were performed to evaluate the impact of different sample processing protocols on subsequent immunoassay analysis.

RESULTS

Using the swabbing technique, a median amount of 40 µL (2-120 µL) wound exudate was collected, which allowed the measurement of several multiplex panels. Comparing both sampling methods, a similar qualitative protein recovery was observed with a trend to analyte enrichment by swabbing. Sample processing using swabs did not affect analyte recovery, with the exception of interleukin (IL)-8, thymus and activation-regulated chemokine, IL-17A, interferon-γ-induced protein 10, and IL-4.

CONCLUSIONS

The quality of wound fluid collected by superficial swabbing is not inferior to the current standard technique. Combined with subsequent bead-based sandwich immunoassay analysis, this new method offers a noninvasive technique, suitable for daily clinical routines, for assessment of inflammatory activity in diabetic foot ulcers.

Role of cytokines in lavage or drainage fluid after hemithyroidectomy in wound healing: involvement of histamine in the acceleration and delay of wound healing

Wound healing is a sophisticated biologic process. In the case of hemithyroidectomy, the operation time is relatively short with small tissue damage and without skin excision, and bacterial contamination before, during, and after the operation is uncommon. Here, we explored which cytokine(s) affected the rates of healing of skin wounds after hemithyroidectomy of 29 patients. We assessed the amounts of cytokines (e.g., interleukin-6, platelet-derived growth factor, basic fibroblast growth factor, vascular endothelial growth factor, and tumor necrosis factor-α) in either the preoperative or postoperative lavage fluids, or in the drainage fluids on postoperative days (PODs) 1-8. All of these cytokines showed a similar pattern; after reaching a peak on POD1, the production fell sharply on POD2-8, revealing that wound healing commenced on POD1. The rates of wound healing were inversely related to the levels of histamine in six patients (i.e., those with the three largest and those with the three smallest total volumes of drainage fluid on POD1): high (or low) levels of histamine in the postoperative lavage fluids with low (or high) levels in the drainage fluids on POD1 caused earlier (or the delay of) wound healing, suggesting involvement of histamine in the acceleration and delay of wound healing.

Prevention of colorectal cancer liver metastasis by exploiting liver immunity via chitosan-TPP/nanoparticles formulated with IL-12

The development of effective therapies for the prevention of colorectal cancer (CRC) liver metastasis is of great importance. Recently, chitosan (CS) nanoparticles have been utilized as carriers of interluekin-12 (IL-12) administered locally to deliver therapeutic proteins and genes. In this study, we encapsulated IL-12 by incorporation using tripolyphosphate (TPP) as the coacervated crosslinking agent to form CS-TPP/IL-12 nanoparticles. We further characterized the association efficiency, rate of release, liver-targeting, and toxicity, which were predominantly dependent on the factors of particle size, zeta potential, pH of solution, and whether or not modified with TPP. Systemic delivery of CS-TPP/IL-12 nanoparticles significantly reduced the number and volume of CRC liver metastasis foci compared to the CS-TPP treated mouse group. Although delivery of IL-12 alone also inhibited the number of CRC liver metastasis observed, further study of the change in hepatic metastasis volume demonstrated no significant differences between the groups treated with CS-TPP or IL-12 alone. Mechanistically, CS-TPP nanoparticles blocked the toxicity of IL-12 and induced infiltration of NK cells and some T cells, which are most likely the effector cells that mediate tumor metastasis inhibition during CS-TPP/IL-12 immunotherapy. The results obtained from this study demonstrate the potential benefit of using chitosan modification technology as a cytokine delivery system for the successful prevention of CRC liver metastasis by exploiting liver immunity.

Vascular and cellular events in post-mastectomy seroma: an immunohistochemical study

This study aimed to describe the vascular and cellular histopathological changes that occurred in post-mastectomy seroma in an animal model. Unilateral mastectomies were conducted on 45 female albino rabbits. On day seven, the skin flap and the underlying tissues of the mastectomy regions were dissected and processed for histopathological examination using immunohistochemical staining of the T- and B-lymphocytes and macrophages (CD3, CD20, and CD68 respectively), and the vascular endothelia. The post-mastectomy regions in the seroma group showed a large number of inflammatory cells and newly formed blood vessels that lost the integrity of their endothelial cell linings, as revealed by the von Willebrand factor staining, as well the basement membrane, as revealed by the histochemical stain. The post-mastectomy seroma beds showed many CD3 and CD20+ve lymphocytes and CD68+ve macrophages. These macrophages were producing angiogenic factors, resulting in the persistent and continuous formation of new blood vessels. These new blood vessels were defective and represented an underlying cause of seroma formation.

Interfraction accumulation of seroma during accelerated partial breast irradiation: preliminary results of a prospective study

PURPOSE

To quantify and characterize the process of seroma accumulation during accelerated partial breast irradiation using multicatheter balloon brachytherapy.

MATERIALS AND METHODS

Twenty-two patients were treated using the Contura Multilumen brachytherapy catheter to a dose of 34Gy in 10 fractions over 5 treatment days. Serial aspirations of the vacuum port of the catheter were performed at the time of CT simulation and before each treatment. Volume and characteristics of fluid drawn were recorded. Univariate analysis was performed to evaluate various factors predictive of seroma formation.

RESULTS

Median patient age was 59.5 years, body mass index was 31, and volume of surgical specimen was 62.4cm(3). Median time from breast conservation surgery to placement of Contura catheter was 18.5 days. Pericatheter seroma, typically scant with a median volume of 0.75mL, was noted in 91% of patients at CT simulation. A total of 203 aspirations were performed with a median-aspirated seroma volume of 4.05mL. There was no significant correlation between the volume of seroma and histology (invasive vs. in situ), quadrant of location, body mass index, reexcision or reoperation, days from breast conservation surgery to balloon placement, or the volume of specimen removed. Radiation treatment factors, including balloon volume, balloon to skin distance, and planning target volume evaluation, also did not correlate with aspirated seroma.

CONCLUSIONS

Interfraction seroma accumulation has a variable pattern of development with no discernible predictors of occurrence. Routine pretreatment aspirations via vacuum port may potentially improve dosimetric reproducibility for a minority of patients.

Tissue repair: The hidden drama

As living beings who encounter every kind of traumatic event from paper cut to myocardial infarction, we must possess ways to heal damaged tissues. While some animals are able to regrow complete body parts following injury (such as the earthworm who grows a new head following bisection), humans are sadly incapable of such feats. Our means of recovery following tissue damage consists largely of repair rather than pure regeneration. Thousands of times in our lives, a meticulously scripted but unseen wound healing drama plays, with cells serving as actors, extracellular matrix as the setting, and growth factors as the means of communication. This article briefly reviews the cells involved in tissue repair, their signaling and proliferation mechanisms, and the function of the extracellular matrix, then presents the actors and script for the three acts of the tissue repair drama.

Incidence and prognostic factors for seroma development after MammoSite breast brachytherapy

PURPOSE

Describe the incidence and identify risk factors for seroma development after MammoSite breast brachytherapy (MBT).

METHODS AND MATERIALS

MBT patient data were prospectively recorded into a quality assurance database. Departmental and electronic records were reviewed to extract patient-, treatment-, and outcome-specific data. Stepwise logistic regression analysis was performed to identify factors associated with development of any seroma including the subset of clinically significant seroma (CSS). CSS was defined as a symptomatic seroma requiring multiple aspirations, biopsy, and/or excision. Variables analyzed included age, weight, number of excisions, time from resection to catheter placement, placement technique, balloon volume, dosimetric factors, and postbrachytherapy infection.

RESULTS

MBT was performed in 109 patients, of whom 97 had minimum 6 months (median, 36) post-MBT follow-up or earlier development of seroma. All patients received 34 Gy to 1cm depth from balloon surface, delivered twice daily in 10 fractions. Seroma developed in 41% of patients at a median of 3 months (range, 0.1-25) post-MBT. One-third of seromas (13% of all patients) were CSS. The only factor identified as statistically significant for development of any seroma was catheter placement on day of resection vs. > or =1 day later (59% vs. 33%; p = 0.0066). Post-MBT infection was highly statistically significant for development of CSS (64% vs. 7%; p<0.0001). Prophylactic antibiotics reduced the risk of post-MBT infection from 37.5% to 6% (p = 0.011).

CONCLUSIONS

The incidence of CSS after MBT is low. Post-MBT infection is statistically significantly associated with CSS development, the incidence of which is reduced with prophylactic antibiotics.

Model of radiation-impaired healing of a deep excisional wound

Despite many well-recognized benefits, administration of ionizing radiation before surgical resection of malignancies is associated with a high risk of wound-healing complications. Most animal models investigating techniques to improve wound healing use a superficial wound. The goal of this study was to develop a novel model of radiation-impaired healing using a deep excisional wound, which is closer to the clinical situation. In the first part of this study, female Lewis rats were exposed to 0, 12, 15, or 18 Gy single-fraction radiation to the buttocks. Three weeks later, deep wounds were created by excision of the gluteus maximus muscle. Irradiated wounds had a lower rate of healing of the surgically created defect than unirradiated wounds (p<0.001), but there was no significant difference between the different doses of radiation. Impaired healing was still evident at 12 weeks. The second part of this study investigated the ability of porcine small-intestinal submucosa (SIS) to improve healing in this animal model. At 6 weeks, wounds implanted with SIS showed improved healing at all doses of radiation compared with unimplanted irradiated wounds. However, higher doses of radiation were still associated with a lower rate of healing. SIS induced a cellular response that was not evident in defects that did not receive SIS, suggesting that SIS has the potential to stimulate repair. This reproducible model of radiation-impaired wound healing closely resembles the clinical setting. The results indicate that this model can be used to investigate new biomaterials as possible therapeutic agents to enhance wound healing.

Cytokines and growth factors in wound drainage fluid from patients undergoing incisional hernia repair

Knowing the dynamics of growth factor and cytokine secretion within the site of a surgical operation is important, as they play a crucial role in the pathophysiology of wound healing and are a target for modifying the repair response. The aim of this study was to evaluate the production of several cytokines and growth factors in the drainage wound fluid from patients undergoing incisional hernia repair: namely, interleukin (IL)-6, IL-10, IL-1alpha, IL-1 ra, interferon-gamma, vascular endothelial growth factors and basic fibroblast growth factor. Ten female patients with abdominal midline incisional hernia undergoing surgical repair were included in this study. In all cases, a closed-suction drain was inserted in the wound below the fascia and removed on postoperative day 4. Wound fluid was collected on postoperative days 1-4 and the amount was recorded each time. Growth factors and cytokines production was evaluated as the whole amount produced over a 24-hour period. In all patients, the amount of drain fluid from surgical wounds was more copious the first day after surgery, it decreased significantly afterward. The presence of all cytokines was highest on postoperative day 1, decreasing over the following days. More specifically, the production of IL-1 ra, IL-6, IL-1alpha, and IL-10 on postoperative day 1 fell sharply on postoperative days 3 and 4, whereas, after an initial reduction, interferon-gamma showed an increase from day 2 onward. Vascular endothelial-derived growth factor production increased progressively after the operation reaching statistical significance only on day 4. As for basic fibroblast growth factor, it showed an opposite pattern: it was higher on postoperative day 1 decreasing thereafter. This analysis of cytokine and growth factor production in the drain fluid will lead us to a better evaluation of the events that follow a surgical wound and to a better understanding of the healing process.

Persistent seroma after intraoperative placement of MammoSite for accelerated partial breast irradiation: Incidence, pathologic anatomy, and contributing factors

PURPOSE

To investigate the incidence of, and possible factors associated with, seroma formation after intraoperative placement of the MammoSite catheter for accelerated partial breast irradiation.

METHODS AND MATERIALS

This study evaluated 38 patients who had undergone intraoperative MammoSite catheter placement at lumpectomy or reexcision followed by accelerated partial breast irradiation with 34 Gy in 10 fractions. Data were collected regarding dosimetric parameters, including the volume of tissue enclosed by the 100%, 150%, and 200% isodose shells, dose homogeneity index, and maximal dose at the surface of the applicator. Clinical and treatment-related factors were analyzed, including patient age, patient weight, history of diabetes and smoking, use of reexcision, interval between surgery and radiotherapy, total duration of catheter placement, total excised specimen volume, and presence or absence of postprocedural infection. Seroma was verified by clinical examination, mammography, and/or ultrasonography. Persistent seroma was defined as seroma that was clinically detectable >6 months after radiotherapy completion.

RESULTS

After a median follow-up of 17 months, the overall rate of any detectable seroma was 76.3%. Persistent seroma (>6 months) occurred in 26 (68.4%) of 38 patients, of whom 46% experienced at least modest discomfort at some point during follow-up. Of these symptomatic patients, 3 required biopsy or complete cavity excision, revealing squamous metaplasia, foreign body giant cell reaction, fibroblasts, and active collagen deposition. Of the analyzed dosimetric, clinical, and treatment-related variables, only body weight correlated positively with the risk of seroma formation (p = 0.04). Postprocedural infection correlated significantly (p = 0.05) with a reduced risk of seroma formation. Seroma was associated with a suboptimal cosmetic outcome, because excellent scores were achieved in 61.5% of women with seroma compared with 83% without seroma.

CONCLUSION

Intraoperative placement of the MammoSite catheter for accelerated partial breast irradiation is associated with a high rate of clinically detectable seroma that adversely affects the cosmetic outcome. The seroma risk was positively associated with body weight and negatively associated with postprocedural infection.

Wound Healing: An Overview

Understanding wound healing today involves much more than simply stating that there are three phases: inflammation, proliferation, and maturation. Wound healing is a complex series of reactions and interactions among cells and "mediators." Each year, new mediators are discovered and our understanding of inflammatory mediators and cellular interactions grows. This article will attempt to provide a concise overview on wound healing and wound management.