Reacción biológica de la cobertura de poliuretano en los implantes de gel de silicona. Trabajo experimental en ratas / Biological reaction of the polyurethane coating on silicone gel implants. Experimental work in rats

Los implantes de silicona recubiertos con poliuretano vulcanizado han reducido signifi cativamente la incidencia de contractura capsular. La FDA suspendió la venta temporalmente en EE.UU. de estos implantes por estudios que sugerían que el 2,4-TDA, metabolito del poliuretano, podría ser cancerígeno. En el año 1995, y por falta de evidencia que sustentara lo anterior, la FDA autorizó nuevamente su uso, pero aún genera controversias. Es nuestro objetivo demostrar cuál es el grado de reabsorción que sufre el poliuretano en relación con el tiempo de colocado el implante en forma experimental con ratas de laboratorio. Material y métodos. Trabajo prospectivo, experimental y a triple ciego. Se colocó en 18 ratas de laboratorio implantes de gel de silicona recubierto con poliuretano de 2 cc marca Silimed. Se realizó la extracción del implante en bloque a los 3, 6, 12, 18 y 24 meses. Se evaluó el nivel de contractura capsular, el espesor macroscópico de la cápsula y el análisis microscópico de la misma. Resultados. En ninguna de las ratas se objetivó contractura capsular. El espesor promedio de la cápsula fue de 1.88 mm (rango 1,8 a 1,92 mm, n: 18, p<0,5) siendo no signifi cativa en comparación con los 2 mm de recubierta original. A nivel microscópico se objetivó una reacción infl amatoria prolongada, reacción de células gigantes y macrófagos próximos a la cubierta, lo que forma una contractura no lineal. También se observo partículas de poliuretano grandes, rodeadas y ancladas a los macrófagos. Este hallazgo muestra que el poliuretano pasa a formar parte de la cápsula y que no se degrada en forma signifi cativa al menos a los 24 meses de haber sido implantados en ratas. Conclusión. Los hallazgos macroscópicos y microscópicos demuestran que el poliuretano pasa a formar parte de la cápsula y no a degradarse y volcarse a la circulación general como así también la formación de una capsula blanda, cuya correlación clínica, es el menor índice de contractura capsular de este tipo de implante

Polyurethane-covered silicone implants have signifi cantly reduced the incidence of capsular contracture. FDA temporarily suspended this product in EE UU due to studies that suggested 2,4-TDA, polyurethane`s metabolite, may be carcinogenic. In 1995, for lack of evidence to support this, its use was authorize by the FDA again, but still generates controversy. It is our objective to demonstrate wich is the degree of resorption of polyurethane cover, regarding the time the implant is placed, in an experimental laboratory rats. Material and methods: Prospective, experimental and triple blind study. It was placed on 18 laboratory rats 2 cc Polyurethane-covered silicone implants manufactured by Silimed. Implants removal was performed in block at 3, 6, 12, 18 and 24 months. It was evaluated the grade of capsular contracture, the macroscopic thickness of the capsule and the microscopic analysis of it. Results: None of the rats evidenced capsular contracture. The average thickness of the capsule was 1.88 mm (range 1.8 to 1.92 mm, n = 18, p <0.5) being not signifi cant compared to the original 2mm coated. The microscopic study evidenced a large infl ammatory reaction, giant cells reaction and macrophages near the coat which makes a nonlinear contracture. Large Polyurethane particles was also observed, surrounded and anchored to macrophages. These fi ndings show that the polyurethane becomes part of the capsule and does not is degraded signifi cantly at least 24 months after being implanted in rats. Conclusion: Macroscopic and microscopic fi ndings demonstrate that the polyurethane coat becomes part of the capsule and is not degraded to go to the general circulation, as well as the formation of a soft capsule, nonlineal, whose clinical correlation, is a lower rate of capsular contracture of this implant

Unnecessary Explantation of IDEAL IMPLANT Structured Saline Breast Implants Prompted byRadiologic Misdiagnosis of Rupture.

ABSTRACT: The unique dual-lumen and baffle design of the IDEAL IMPLANT Structured Saline breast implant gives it specific advantages over both silicone gel-filled and the original saline-filled implants. This internal baffle structure also gives it an appearance on various radiologic imaging studies that may be misinterpreted as a rupture because of similarities to the well-known radiologic appearance of a ruptured silicone gel implant. Patients may present with various misinterpreted imaging studies, highlighting the need for plastic surgeons and radiologists to be familiar with the normal appearance of the intact IDEAL IMPLANT and be able to distinguish it from a ruptured IDEAL IMPLANT. The radiology findings must be correlated with the clinical findings, or an intact IDEAL IMPLANT misdiagnosed as ruptured, may cause unnecessary patient worry, and may prompt unnecessary surgery for removal or replacement.

Immediate Breast Reconstruction With Latissimus Dorsi Myocutaneous Flap and Silicone Implant Followed by Adjuvant Radiotherapy for Breast Cancer.

BACKGROUND: About 30% to 50% of women with breast cancer undergo mastectomy, and approximately 50% of them will receive adjuvant radiotherapy (ART). This study evaluates the medium- and long-term impact of ART after immediate breast reconstruction (IBR) with latissimus dorsi myocutaneous (LDM) flap and silicone implants. METHODS: Clinical, surgical, and oncological data were retrospectively collected and analyzed based on the medical records of 176 patients who had undergone IBR with LDM flap and silicone implants. RESULTS: The data showed that 7.4% of patients had a history of previous radiotherapy, 56.3% received ART, 31.8% developed capsular contracture with a mean follow-up of 58.1 months, and 14.2% of surgeries were categorized as procedures with a prolonged operating time, lasting above 1 SD of the observed mean. Those who experienced prolonged operating time (odds ratio, 4.72; 95% confidence interval, 1.72-12.93; P = 0.003) and those who received ART (odds ratio, 7.38; 95% confidence interval, 3.18-17.10; P < 0.001) were more likely to develop capsular contracture. Thirty-two patients (18%) underwent capsulectomy with implant replacement, and 7 patients (4%) had the implant removed. The mean time between IBR and reoperation was 29.1 months. Patients who received ART were 2.84 times more likely to experience reconstruction failure or undergo implant-related reoperation ( P = 0.002). CONCLUSIONS: The results indicated that IBR with LDM flap and silicone implant followed by ART is a safe procedure, resulting in low rates of reconstruction failure. However, ART increased the likelihood of capsular contracture development and implant-related reoperation, having a negative effect on reconstructed breasts.

Self-reported systemic symptoms among women with breast implants.

Around 2,500 women receive a breast augmentation with silicone-based implants yearly in Denmark. A number of these women report various uncharacteristic systemic symptoms, which they attribute to the breast implants, including impaired cognition, joint pain, etc. This condition has been termed "breast implant illness" and is currently not a recognised diagnosis. The correlation between the patient's self-reported symptoms and breast implants has not been established and there is limited evidence that surgery has any effect. In this review, the current literature on the topic has been reviewed.

Altered Foreign Body Response at the Posterior Surface Compared to the Anterior Surface of Human Silicone Breast Implants.

Soft implantable devices are crucial to optimizing form and function for many patients. However, periprosthetic capsule fibrosis is one of the major challenges limiting the use of implants. Currently, little is understood about how spatial and temporal factors influence capsule physiology and how the local capsule environment affects the implant structure. In this work, we analyzed breast implant capsule specimens with staining, immunohistochemistry, and real-time polymerase chain reaction to investigate spatiotemporal differences in inflammation and fibrosis. We demonstrated that in comparison to the anterior capsule against the convex surface of breast implants, the posterior capsule against the flat surface of the breast implant displays several features of a dysregulated foreign body reaction including increased capsule thickness, abnormal extracellular remodeling, and infiltration of macrophages. Furthermore, the expression of pro-inflammatory cytokines increased in the posterior capsule across the lifespan of the device, but not in the anterior capsule. We also analyzed the surface oxidation of breast explant samples with XPS analysis. No significant differences in surface oxidation were identified either spatially or temporally. Collectively, our results support spatiotemporal heterogeneity in inflammation and fibrosis within the breast implant capsule. These findings presented here provide a more detailed picture of the complexity of the foreign body reaction surrounding implants destined for human use and could lead to key research avenues and clinical applications to treat periprosthetic fibrosis and improve device longevity.

The Effect of 3-Dimensional-Printed Sequential Dual Drug-Releasing Patch on the Capsule Formation Around the Silicone Implant in a Rat Model.

BACKGROUND: Implant-based breast reconstruction is associated with increased risk of early infection and late-stage capsular contracture. OBJECTIVES: We evaluated the feasibility of a dual drug-releasing patch that enabled the controlled delivery of antibiotics and immunosuppressants in a temporally and spatially appropriate manner to the implant site. METHODS: The efficacy of a dual drug-releasing patch, which was 3-dimensional-printed (3D-printed) with tissue-derived biomaterial ink, was evaluated in rats with silicone implants. The groups included implant only (n = 10); implant plus bacterial inoculation (n = 14); implant, bacterial inoculation, and patch loaded with gentamycin placed on the ventral side of the implant (n = 10), and implant, bacterial inoculation, and patch loaded with gentamycin and triamcinolone acetonide (n = 9). Histologic and immunohistochemical analyses were performed 8 weeks after implantation. RESULTS: The 2 drugs were sequentially released from the dual drug-releasing patch and exhibited different release profiles. Compared to the animals with bacterial inoculation, those with the antibiotic-only and the dual drug-releasing patch exhibited thinner capsules and lower myofibroblast activity and inflammation, indicating better tissue integration and less foreign body response. These effects were more pronounced with the dual drug-releasing patch than with the antibiotic-only patch. CONCLUSIONS: The 3D-printed dual drug-releasing patch effectively reduced inflammation and capsule formation in a rat model of silicone breast reconstruction. The beneficial effect of the dual drug-releasing patch was better than that of the antibiotic-only patch, indicating its therapeutic potential as a novel approach to preventing capsular contracture while reducing concerns of systemic side effects.

Prevalence, clinical characteristics, and management of silicone lymphadenopathy: A systematic review of the literature.

INTRODUCTION: Implant-based breast augmentations and reconstructions are one of the most common surgical procedures performed by plastic surgeons in the United States, which has rapidly increased in popularity since the 2000s. Silicone lymphadenopathy (SL) is a complication of breast implants that involves migration of silicone to nearby soft tissue/lymph nodes. Data on its clinical features and management is scarce. METHODS: SL-related search terms were used to find articles in 3 databases. Of 598 articles, 101 studies met the inclusion criteria. Demographics, clinical presentation, workup, and management data were analyzed. RESULTS: Of 279 cases of SL and 107 with information on initial diagnosis, 35 (33%) were incidental. The most common symptom was painless lymphadenopathy, followed by painful lymphadenopathy. 251 (95%) and 13 (5%) patients had silicone and saline implants, respectively. 149 (68%) patients had implant rupture. Axillary lymphadenopathy was the most affected region (136 cases, 72%), followed by internal mammary (40 cases, 21%), cervical/supraclavicular (36 cases, 19%), and mediastinal (24 cases, 13%) regions. 25% of patients underwent fine-needle aspiration, 12% core needle biopsy, and 59% excisional biopsy. 32% of cases underwent explantation and/or implant exchange. The most common indication for surgery was implant rupture. Histology showed multinucleated giant cells, large histiocytes, and silicone accumulation. CONCLUSIONS: SL is a complication associated with breast implants. The majority of patients are asymptomatic, and most cases are managed conservatively. Minority need a biopsy and surgical interventions due to abnormal imaging, persistent symptoms, and/or implant rupture. Workup and management should be tailored to the patient.

Silicone Particles in Capsules Around Breast Implants: An Investigation Into Currently Available Implants in North America.

BACKGROUND: Breast implants have always been composed of a silicone elastomer envelope filled with either silicone gel or saline. Breast implant illness (BII) is a set of symptoms that has previously been linked to the leakage of silicone particles from the implants into the body. OBJECTIVES: Our research aimed to quantify the number of silicone particles present in the capsules of breast implants available in North America. METHODS: Thirty-five periprosthetic capsules were sampled and analyzed, and silicone particles were counted and measured. The capsule surface area was then measured and utilized to calculate particle density and total number of silicone particles. RESULTS: Eighty-five percent of capsules analyzed from silicone gel implants contained silicone, with an average of 62 particles per mm3 of capsular tissue. These implants had approximately 1 million silicone particles per capsule. In contrast, none of the saline implant capsules contained silicone. Capsules from macrotextured tissue expanders contained fewer and larger silicone particles. CONCLUSIONS: Silicone gel implants presented silicone particle bleeding into the periprosthetic capsule, totaling on average 1 million silicone particles per capsule. On the other hand, no silicone particle bleeding was observed from saline breast implants. These data suggest that particle bleeding comes from the inner silicone gel, and not from the smooth outer silicone shell. Previous studies have reported the presence of breast implant illness in patients with both silicone- and saline-filled implants. Therefore, our data suggest that silicone migration is not the sole cause of BII.