Flector tissugel used to treat capsular contracture after breast augmentation surgery

Identification of Drug Compounds for Capsular Contracture Based on Text Mining and Deep Learning

BACKGROUND

Capsular contracture is a common and unpredictable complication after breast implant placement. Currently, the pathogenesis of capsular contracture is unclear, and the effectiveness of nonsurgical treatment is still doubtful. The authors' study aimed to investigate new drug therapies for capsular contracture by using computational methods.

METHODS

Genes related to capsular contracture were identified by text mining and GeneCodis. Then, the candidate key genes were selected through protein-protein interaction analysis in Search Tool for the Retrieval of Interacting Genes/Proteins and Cytoscape. Drugs targeting the candidate genes with relation to capsular contracture were screened out in Pharmaprojects. Based on the drug-target interaction analysis by DeepPurpose, candidate drugs with highest predicted binding affinity were obtained eventually.

RESULTS

The authors' study identified 55 genes related to capsular contracture. Gene set enrichment analysis and protein-protein interaction analysis generated eight candidate genes. One hundred drugs targeting the candidate genes were selected. The seven candidate drugs with the highest predicted binding affinity were determined by DeepPurpose, including tumor necrosis factor alpha antagonist, estrogen receptor agonist, insulin-like growth factor 1 receptor, tyrosine kinase inhibitor, and matrix metallopeptidase 1 inhibitor.

CONCLUSION

Text mining and DeepPurpose can be used as a promising tool for drug discovery in exploring nonsurgical treatment to capsular contracture.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, V.

Pharmacological Approaches for the Prevention of Breast Implant Capsular Contracture

Capsular contracture is a common complication associated with breast implants following reconstructive or aesthetic surgery in which a tight or constricting scar tissue capsule forms around the implant, often distorting the breast shape and resulting in chronic pain. Capsulectomy (involving full removal of the capsule surrounding the implant) and capsulotomy (where the capsule is released and/or partly removed to create more space for the implant) are the most common surgical procedures used to treat capsular contracture. Various structural modifications of the implant device (including use of textured implants, submuscular placement of the implant, and the use of polyurethane-coated implants) and surgical strategies (including pre-operative skin washing and irrigation of the implant pocket with antibiotics) have been and/or are currently used to help reduce the incidence of capsular contracture. In this article, we review the pharmacological approaches-both commonly practiced in the clinic and experimental-reported in the scientific and clinical literature aimed at either preventing or treating capsular contracture, including (i) pre- and post-operative intravenous administration of drug substances, (ii) systemic (usually oral) administration of drugs before and after surgery, (iii) modification of the implant surface with grafted drug substances, (iv) irrigation of the implant or peri-implant tissue with drugs prior to implantation, and (v) incorporation of drugs into the implant shell or filler prior to surgery followed by drug release in situ after implantation.

Nonsurgical treatment of capsular contracture: Review of clinical studies

Capsular contracture is one of the most distressing complications of breast implant use in both aesthetic and reconstructive plastic surgery procedures. This systematic review was performed to assess the effectiveness of all nonsurgical treatments for established capsular contracture.

Suppressive Effect of Leukotriene Antagonists on Capsular Contracture in Patients Who Underwent Breast Surgery with Prosthesis: A Meta-Analysis

BACKGROUND

Capsular contracture is a troublesome and distressing complication in mammaplasty or breast reconstruction involving a prosthesis. Previous studies have indicated that leukotriene antagonists effectively reverse capsular contracture. However, this treatment method lacks comprehensive support from evidence-based medicine and remains considerably controversial. In this study, a meta-analysis was conducted to evaluate the therapeutic and preventive effects of leukotriene antagonists on capsular contracture in patients after breast prosthesis implantation.

METHODS

A comprehensive literature search was performed in English and Chinese databases. All clinical studies assessing the therapeutic and prophylactic effects of leukotriene antagonists on capsule contracture after breast prosthesis implantation were selected. Risk differences and 95 percent confidence intervals were applied as the final pooled statistics.

RESULTS

A total of five eligible studies were included, involving 1710 breast prosthesis implantations. The final results indicated that leukotriene antagonists markedly inhibited capsular contracture formation, with statistical significance at 32.02 (p < 0.001) (pooled risk difference, 0.84; 95 percent CI, 0.79 to 0.89). In subgroup analysis, subgroups based on different leukotriene antagonists included the montelukast and zafirlukast groups, with significant pooled statistical levels of 19.34 (p < 0.001) and 79.48 (p < 0.001), respectively (montelukast: pooled risk difference, 0.83; 95 percent CI, 0.75 to 0.92; zafirlukast: pooled risk difference, 0.85; 95 percent CI, 0.83 to 0.87), indicating that both montelukast and zafirlukast were effective in inhibiting encapsulation.

CONCLUSIONS

This meta-analysis demonstrated that leukotriene antagonists (montelukast and zafirlukast) have significant effects in treating and preventing capsular contracture. These medications should be administered in a reasonable and safe way. Further studies of clinical efficacy, duration, safety, and exact mechanism of leukotriene antagonists for periprosthetic capsular contracture are warranted.

The role of angiogenesis, inflammation and estrogen receptors in breast implant capsules development and remodeling

BACKGROUND

Capsular contracture is the most common complication following breast implant placement. The multiple factors unbalancing the physiological response to the foreign body have not been fully elucidated. The aim of this study was to investigate the role of neo-angiogenesis, inflammation and estrogen receptors in peri-prosthetic tissue development and remodeling.

METHODS

The study enrolled 31 women who underwent expander substitution with definitive implant. Specimens were stained with hematoxylin/eosin, Masson trichrome, immunohistochemistry and immunofluorescence for alpha-smooth muscle actin, estrogen receptor-α (ER-α), estrogen receptor-β (ER-β), Collagen type I and III, CD31 (as a marker of neo-angiogenesis) and vascular endothelial growth factor (VEGF). Inflammatory infiltration was quantified and analyzed. Transmission electron microscopy was performed for ultrastructural evaluation.

RESULTS

Myofibroblasts, mainly localized in the middle layer of capsular tissue, expressed VEGF, ER-α and ER-β. ER-β expression positively correlated with Collagen type I deposition (p= 0.025). Neo-angiogenesis was predominant in the middle layer. CD31 expression positively correlated with Collagen type I expression (p=0.009) and inflammatory infiltration grade (p= 0.004). The degree of inflammatory infiltration negatively correlated with the time from implantation (p = 0.022).

DISCUSSION

The middle layer is key in the development and remodeling of capsular tissue. Myofibroblasts produce VEGF, that induces neo-angiogenesis. New vessels formation is also correlated to the inflammatory response. Collagen deposition is associated with ER-β expression and neo-angiogenesis. These findings may prelude to targeted pharmacologic therapies able to control such interactions, thus hampering the self-sustaining loop promoting the progression of physiologic fibrosis toward pathologic contracture.

The aetiopathogenesis of capsular contracture: A systematic review of the literature

BACKGROUND

Capsular contracture is the most frequent complication after breast augmentation or reconstruction with breast implants. The immune system plays a prominent role in capsular contracture formation, albeit to an unknown extent. Bacterial contamination in situ has been hypothesized to be causative for capsular contracture. How this relates to the immunological processes involved is unknown. This article aims to provide an overview of immunological and bacterial factors involved in development of capsular contracture.

MATERIALS AND METHODS

We undertook a systematic literature review focused on immunological factors and microbiota in relation to capsular contraction around implants. This systematic review was performed in accordance with the PRISMA guidelines. PubMed, EMBASE, and the Cochrane databases were searched from inception up to October 2016. Included studies were assessed for the following variables: subject characteristics, number of capsules, primary indication for surgery, surgical procedure, follow-up or implant duration, study methods, type of antibiotics or medical therapies and outcomes related to microbiota and immunological factors.

RESULTS

Data on immunological factors and bacterial contamination were retrieved from 64 included studies. Notably the presence of macrophages and Staphylococcus epidermidis within capsules was often associated with capsular contracture.

CONCLUSION

This review provides a clear overview of the immunological factors associated with capsular contracture and provides a hypothetical immunological model for development of the disease. Furthermore, an overview of bacterial contamination and associations with capsular contracture has been provided. Follow-up research may result in clinical recommendations to prevent capsular contracture.

Role of Mitomycin C in Preventing Capsular Contracture in Implant-Based Reconstructive Breast Surgery: A Randomized Controlled Trial

BACKGROUND

Capsular contracture represents the most frequent complication after implant-based breast reconstruction. An experimental study on mice demonstrated that capsule formation around breast implants is considerably diminished after topical application of mitomycin C. The authors conducted a randomized controlled clinical trial investigating the efficacy of mitomycin C in reducing capsular contracture rates following implant-based breast reconstruction after mastectomy for breast cancer.

METHODS

The authors randomized all women older than 18 years scheduled for the second stage of an implant-based breast reconstruction after mastectomy for breast cancer at the National Cancer Institute in Milan from October of 2005 to February of 2010 to receive or not receive the topical application of mitomycin C during surgery. The authors assessed capsular contracture, major postoperative complications, and aesthetic outcome.

RESULTS

The authors randomized 322 patients to receive mitomycin C or not at the second stage of implant-based breast reconstruction. One hundred sixty-two patients were allocated to the mitomycin C group and 160 patients were allocated to the control group. The relative risk of capsular contracture in the mitomycin C group was 0.92 (95 percent CI, 0.60 to 1.41). Major complications leading to reintervention, oncologic outcomes, and aesthetic outcomes were comparable between the two groups.

CONCLUSIONS

This is the first trial reporting data about the use of mitomycin C in breast reconstructive surgery in a clinical setting. Mitomycin C seems not to significantly affect capsular contracture rate and severity following implant-based reconstructive breast surgery at the tested doses.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, I.

Effects of Medical Chitosan on Capsular Formation Following Silicone Implant Insertion in a Rabbit Model

BACKGROUND

Capsular contracture is a serious complication that occurs after breast implant surgery. This study was performed to confirm that medical chitosan (MC) affects capsule formation and elucidates a possible mechanism.

MATERIALS AND METHODS

In this study, we used 18 female adult New Zealand White rabbits. In each rabbit, two silicone implants were placed under the pectoralis muscle layer on both sides (one side was included in the experimental group and the other side was included in the control group). MC was applied around the silicone implant of the experiment group, while the control group received no treatment. The capsular thickness was calculated by Masson's trichrome stain. The expression of MMPs and TIMPs were determined by real-time PCR, Western blotting, and immunohistochemistry.

RESULTS

Compared to the control group, the capsular thickness of the MC group was significantly reduced at 4, 8, and 12 weeks after the operation (4 week: 229.3 ± 72.2 vs 76.1 ± 12.6 µm, p < 0.05; 8 week: 326.0 ± 53.8 vs 155.4 ± 61.7 µm, p < 0.0.5; 12 week: 151.2 ± 52.5 vs 60.0 ± 22.0 µm, p < 0.05). Compared to the control group, the MC group had significantly lower expressions of TIMP-1 and TIMP-2 (p < 0.05). However, compared to the control group, there was no statistically significant difference in the expressions of MMP-2 and MMP-9 in the experiment group (p > 0.05).

CONCLUSION

MC reduced the risk of developing capsular contracture around silicone implants, possibly by blocking the signaling pathway of TIMPs.

NO LEVEL ASSIGNED

This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

An innovative procedure for the treatment of primary and recurrent capsular contracture (CC) following breast augmentation

BACKGROUND

Capsular contracture (CC) is the most frequently reported complication following alloplastic breast augmentation. At present, none of the available preventive measures are effective, and various treatment modalities have been advocated. Reduction of the inflammatory process is critical for successful treatment. Late intracapsular glucocorticosteroid (GC) injections have been somewhat effective for the treatment, but the fine balance between the effectiveness of therapeutic GC dosages and their potential serious side effects is of utmost importance.

OBJECTIVES

The authors investigate whether instillation of a rapid-acting water-soluble GC in the implant pocket during the early proliferative phase of wound healing is more effective than delayed instillation during the remodeling phase.

METHODS

Between 2003 and 2009, 33 consecutive patients presenting with CC (Baker grades III and IV) were managed by capsulectomy with implant replacement and corticosteroid therapy immediately as well as 2 to 3 days later through an indwelling catheter left in place for that period. This delayed but early administration is a novel technique for GC injection.

RESULTS

Complete correction of the contracture with no recurrence was achieved in all patients with a follow-up range of 2 to 10 years.

CONCLUSIONS

This GC administration technique avoids the potential complications of long-term, slow corticosteroid release. It has a targeted anti-inflammatory effect, probably at a critical stage of the healing process, and could effectively prevent CC following alloplastic breast augmentation.

Transdermal diclofenac patches for control of post-extraction pain. Pilot randomized controlled double-blind study

PURPOSE

The scope of transdermal analgesics have been limited to pain control following local trauma, muscle spasm, minor esthetic surgeries, or sports-related injuries. Its scope of application can be extended in the field of dentistry and minor oral surgical procedures.

METHODS

A total of 40 healthy patients between the age of 18 and 50 years with deeply carious, nontender mandibular molar tooth deemed unsalvageable which was indicated for extraction were taken into study of which subjects were divided into cases and controls.

RESULTS

The data were analyzed with chi-square test and Mann-Whitney U test; the chi-square test showed significant association with expected outcome in visual analog scale pain scores, the two groups at 6th and 12th hour. A Mann-Whitney U test was performed to identify strength of association between two groups where there were significant association between all parameters except for pain interference with routine activities and dental health status(0.022, 0.001); the differences between two groups in these parameters were significant (<0.05).

CONCLUSION

Transdermal route seems to be comparable to oral diclofenac in post-extraction pain relief; further studies are required to confirm the results and safety for its use in various other dental situations.