The use of meshes and matrices in breast reconstruction

Soft, Long-Lived, Bioresorbable Electronic Surgical Mesh with Wireless Pressure Monitor and On-Demand Drug Delivery

Current research in the area of surgical mesh implants is somewhat limited to traditional designs and synthesis of various mesh materials, whereas meshes with multiple functions may be an effective approach to address long-standing challenges including postoperative complications. Herein, a bioresorbable electronic surgical mesh is presented that offers high mechanical strength over extended timeframes, wireless post-operative pressure monitoring, and on-demand drug delivery for the restoration of tissue structure and function. The study of materials and mesh layouts provides a wide range of tunability of mechanical and biochemical properties. Dissolvable dielectric composite with porous structure in a pyramidal shape enhances sensitivity of a wireless capacitive pressure sensor, and resistive microheaters integrated with inductive coils provide thermo-responsive drug delivery system for an antibacterial agent. In vivo evaluations demonstrate reliable, long-lived operation, and effective treatment for abdominal hernia defects, by clear evidence of suppressed complications such as adhesion formation and infections.

Prolonged operative time is a risk factor for adverse postoperative outcomes in the unilateral deep inferior epigastric perforator (DIEP) flap surgery: A retrospective cohort study

BACKGROUND

Currently, one published study documented operative time (OT) as a predictor for postoperative outcomes in bilateral deep inferior epigastric perforator (DIEP) flap breast reconstructions. No literature has investigated this in unilateral DIEP flaps. We aimed to determine the relationship between unilateral OT, postoperative complications, unplanned reoperations (UR), and extended length-of-stay (eLOS).

METHODS

Patients who underwent elective unilateral DIEP reconstruction from 2018 to 2023 at a tertiary centre in London, United Kingdom, were retrospectively analysed. Patients were divided into four groups depending on OT quartiles to define a critical cut-off period. Data on extensive covariates, including procedural complexity, was recorded and used in univariable and multivariable regression models.

RESULTS

The final cohort contained 173 patients. After risk-adjustment, ≥421-minute operations led to a significantly higher overall complication rate (HR: 2.14, 95% CI: 1.26, 3.64, p = 0.005) relative to <421 min. Significantly higher odds of eLOS were observed in the ≥460-minute group (OR: 2.07, 95% CI: 1.07, 3.99, p = 0.03) compared to <460 min. There was no significant effect on the rate of postoperative UR across any OT group.

CONCLUSIONS

We confirmed OT was an independent predictor for postoperative outcomes in the DIEP flap, and demonstrated this in unilateral reconstructions. A clinical maximum threshold of 7 h was derived based on this cohort to help guide future surgical practice. Efficiency can be achieved by meticulous preoperative planning and process standardisation, multiple senior surgeons working per flap, and smooth teamwork between specialities and intraoperative staff.

Comparison of a human acellular dermal matrix and a polypropylene mesh for pelvic floor reconstruction: a randomized trial study in a rabbit model

Non-absorbable polypropylene (PP) meshes have been widely used in surgical reconstruction of the pelvic floor disorders. However, they are associated with serious complications. Human acellular dermal matrices (hADM) have demonstrated safety and efficacy in reconstructive medicine, but their suitability and efficacy at vaginal level is not known. This study compares the biological performance of PP mesh and a newly developed hADM. 20 rabbits were randomized to receive the hADM graft or the PP mesh. Grafts were surgically implanted in the abdominal wall and vagina. After 180 days, grafts were explanted and evaluated. The vaginal mesh extrusion rate was higher in the PP group (33% vs. 0%, p = 0.015). Full integration of the vaginal grafts was more frequent in the hADM group, where 35% of the grafts were difficult to recognize. In the PP group, the vaginal mesh was identified in 100% of the animals (p = 0.014). In PP group, the infiltrates had a focal distribution and were mostly located in the internal part of the epithelium, while in the hADM group, the infiltrates had a diffuse distribution. Additionally, the hADM group also presented more B-lymphocytes and less T-lymphocytes. Biomechanical analysis showed that hADM had lower resistance to stress. Moreover, PP mesh stiffness and elasticity were higher. Then, hADM is associated with fewer clinical complications, as well as better tissue integration. However, it shows greater incorporation into the surrounding native tissue, especially in the vaginal location, undergoing a reduction in its biomechanical properties 6 months after implantation.

Biological Cover Mitigates Disruption of the Dermal Structure in Mechanically Expanded Skin in a Porcine Model

Tissue expansion is an integral procedure of the vast majority of breast reconstruction and has a significant impact on the final clinical outcomes. Therefore, technological advances leading to a fewer number of unfavorable outcomes and a decrease in complication rates are imperative. In this study, using a porcine model, we investigated an effect of acellular dermal matrix (ADM) used as a tissue expander cover on the dermal changes induced by mechanical forces during tissue expansion. After 14 days of expansion, skin samples were collected from one animal, while the second animal underwent radiation, and tissue was collected 8 weeks later. Tissue expanded without the use of ADM and unexpanded skin served as the controls. Collected skin biopsies were used for histological and immunohistochemical evaluation, and for gene expression analysis. We revealed that the biological cover incorporation into host tissue is facilitated by macrophages without inducing a broad inflammatory response. The utilization of ADM mitigated disruption in the dermal structure, excessive collagen deposition, and capsule formation in non-irradiated expanded skin. The protective effect was not fully maintained in irradiated skin. These results demonstrate that tissue expansion might be improved by using the tissue expander cover.

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.

[The Value of Synthetic and Biologic Meshes in Implant-Based Breast Reconstruction]

Implant based breast reconstruction (IBBR) keeps evolving and has been influenced heavily by the use of synthetic and biologic meshes in the last years. In both, subpectoral as well as prepectoral approaches the use of synthetic and biologic meshes has made it possible to place implants precisely according to the breast's footprint and strengthen soft-tissue coverage, particularly in the lower pole of the breast with lower complication rates and better cosmesis. Various mesh options that differ in material, processing, size and cost are currently in clinical use. This review aims to define the role of biologic and synthetic meshes in IBBR regarding the advantages and disadvantages of their use.

Immediate direct-to-implant breast reconstruction: A single center comparison between different procedures

Background

The increased incidence of conservative mastectomy operations (nipple- and skin- sparing) has increased the frequency of immediate breast reconstructions (IBR). In order to guarantee patients the best possible aesthetic outcome, the least chance of complications and moreover, the least postoperative pain, the technique with prepectoral prosthetic pocket was recently reconsidered with the use of ADM. This is the first study using Fortiva® in prepectoral breast reconstruction, and it compares the outcomes of three different patient populations (undergoing retromuscular, prepectoral and prepectoral reconstruction with ADM). The authors suggest that prepectoral breast reconstruction with ADM may bring benefits compared to the current standard technique (retromuscular) as well as compared to the prepectoral reconstruction without ADM.

Methods

Retrospective data analysis of patients who underwent mastectomy followed by immediate breast reconstruction with silicone implants (DTI), performed by a team of breast surgeons and plastic surgeons. Logistic factor regressions were performed in order to investigate the effects of the three different intervention techniques on the incidence of complications. Fisher's exact test was used to analyze the differences in the occurrence of each complication. Mann Whitney test was used to compare the averages of referred pain. A p value &lt;0.05 was considered significant.

Results

A total of 67 patients underwent DTI reconstruction, of which 43 with retromuscular prosthesis, 13 prepectoral and 11 prepectoral with ADM. We found a significantly lower incidence of surgical complications with ADM, exclusively in comparison with retromuscular reconstruction (p = 0.028). It emerges prepectoral reconstruction with ADM involves significantly less visibility of the implant than both the prepectoral surgery without ADM (p = 0.013) and the retromuscular technique (p = 0.029). Finally, postoperative pain referred at twelfth month is significantly less relevant in the group with prepectoral prosthesis and ADM, both in the group with retromuscular (p &lt; 0.001) and prepectoral without ADM (p = 0.001).

Conclusions

This study demonstrates that immediate prepectoral breast reconstruction with ADM is a safe and reliable technique, able to exceed some type of limits imposed by prepectoral reconstruction. Moreover, it provides benefits if compared to the current standard technique. In the future, this technique could also be added to it, after a proper selection of patients in pre- and intraoperative time.

Implant-Based Breast Reconstruction after Mastectomy, from the Subpectoral to the Prepectoral Approach: An Evidence-Based Change of Mind?

Over the last years, prepectoral implant-based breast reconstruction has undergone a renaissance due to several technical advancements regarding mastectomy techniques and surgical approaches for the placement and soft tissue coverage of silicone implants. Initially abandoned due to the high incidence of complications, such as capsular contraction, implant extrusion, and poor aesthetic outcome, the effective prevention of these types of complications led to the prepectoral technique coming back in style for the ease of implant placement and the conservation of the pectoralis muscle function. Additional advantages such as a decrease of postoperative pain, animation deformity, and operative time contribute to the steady gain in popularity. This review aims to summarize the factors influencing the trend towards prepectoral implant-based breast reconstruction and to discuss the challenges and prospects related to this operative approach.

Next-generation surgical meshes for drug delivery and tissue engineering applications: materials, design and emerging manufacturing technologies

Abstract

Surgical meshes have been employed in the management of a variety of pathological conditions including hernia, pelvic floor dysfunctions, periodontal guided bone regeneration, wound healing and more recently for breast plastic surgery after mastectomy. These common pathologies affect a wide portion of the worldwide population; therefore, an effective and enhanced treatment is crucial to ameliorate patients’ living conditions both from medical and aesthetic points of view. At present, non-absorbable synthetic polymers are the most widely used class of biomaterials for the manufacturing of mesh implants for hernia, pelvic floor dysfunctions and guided bone regeneration, with polypropylene and poly tetrafluoroethylene being the most common. Biological prostheses, such as surgical grafts, have been employed mainly for breast plastic surgery and wound healing applications. Despite the advantages of mesh implants to the treatment of these conditions, there are still many drawbacks, mainly related to the arising of a huge number of post-operative complications, among which infections are the most common. Developing a mesh that could appropriately integrate with the native tissue, promote its healing and constructive remodelling, is the key aim of ongoing research in the area of surgical mesh implants. To this end, the adoption of new biomaterials including absorbable and natural polymers, the use of drugs and advanced manufacturing technologies, such as 3D printing and electrospinning, are under investigation to address the previously mentioned challenges and improve the outcomes of future clinical practice. The aim of this work is to review the key advantages and disadvantages related to the use of surgical meshes, the main issues characterizing each clinical procedure and the future directions in terms of both novel manufacturing technologies and latest regulatory considerations.

Graphic abstract