Do Bacteria and Biofilm Play a Role in Double-Capsule Formation around Macrotextured Implants?

BACKGROUND: The double capsule is a complication mostly described in aggressive macrotextured implants. Mechanical shear stress applied onto an immature periprosthetic capsule has been linked to their formation. The authors aim to demonstrate the role of bacterial phenotype and biofilm in the development of the double capsule. METHODS: Seven double capsules formed at the interface of macrotextured breast expander implants were studied using scanning electron microscopy. Two samples for each surface of the inner capsule layer (the prosthesis interface and the intercapsular space) were analyzed for bacteria cell size, bacterial density, and biofilm deposition. RESULTS: Although all routine bacterial cultures were negative, the prosthesis interface had both higher bacteria load and biofilm deposition compared with the intercapsular space (Mann-Whitney U test, p = 0.004 and p = 0.008, respectively). Moreover, bacteria cell sizes were significantly smaller at the prosthesis interface in six of seven samples. Comparison of bacteria density and biofilm dispersion showed an increase of biofilm extracellular matrix deposition over 2000 cells/mm (linear regression, p = 0.0025). These results indicate a common trend among bacteria species. CONCLUSIONS: Bacterial expression between the different surfaces of the double capsule displays significant differences; bacteria at the prosthesis interface are mostly in a biofilm state, whereas they demonstrate a planktonic phenotype at the intercapsular space. When a sufficient amount of bacteria are present at a specific location, quorum sensing may trigger a biofilm phenotypic switch in planktonic bacteria cells. Biofilm formation may alter capsule formation through immune response, thereby weakening capsule strength and facilitating extracellular matrix delamination and double-capsule formation. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.

The impact of postoperative expansion initiation timing on breast expander capsular characteristics: a prospective combined clinical and scanning electron microscopy study.

BACKGROUND: In the first stage of expander-to-implant breast reconstruction, postoperative expansion is classically initiated at 10 to 14 days (conventional approach). The authors hypothesized that it may be beneficial to wait 6 weeks postoperatively before initiating serial expansion (delayed approach). Clinical and ultrastructural periprosthetic capsule analysis is first required before determining whether a delayed approach ultimately improves capsular tissue adherence and expansion process predictability. METHODS: Patients undergoing two-stage implant-based breast reconstruction were enrolled prospectively in this study. During expander-to-implant exchange, the clinical presence of "Velcro" effect, biofilm, and double capsule was noted. Periprosthetic capsule samples were also sent for scanning electron microscopic observation of three parameters: surface relief, cellularity, and biofilm. Samples were divided into four groups for data analysis (group 1, conventional/Biocell; group 2, delayed/Biocell; group 3, conventional/Siltex; and group 4, delayed/Siltex). RESULTS: Fifty-six breast reconstructions were included. Each group comprised between 13 and 15 breasts. In group 1, no cases exhibited the Velcro effect and there was a 53.8 percent incidence of both biofilm and double capsule. In group 2, all cases demonstrated the Velcro effect and there were no incidences of biofilm or double capsule. Group 3 and group 4 cases did not exhibit a Velcro effect or double-capsule formation; however, biofilm was present in up to 20.0 percent. All group 2 samples revealed more pronounced three-dimensional relief on scanning electron microscopy. CONCLUSIONS: Variations in expansion protocols can lead to observable modifications in periprosthetic capsular architecture. There may be real benefits to delaying expander inflation until 6 weeks postoperatively with Biocell expanders.

A review of 105 subscapular-based flaps harvested using a new dorsal decubitus position: how far can we go?

OBJECTIVE: Interest in flaps based on the subscapular vascular system has decreased because of the need for intraoperative patient repositioning and the inability to employ a simultaneous 2-team approach. The aims of this study are to review our experience using dorsal decubitus patient positioning for subscapular-based flap harvest and to demonstrate the effectiveness and safety of this approach. METHODS: A retrospective review of all subscapular-based flap cases performed by the senior author at 2 hospital centers from 1995 to 2010 was conducted. Variables studied included indications for reconstruction, flap characteristics, and postoperative complications. A longitudinal roll placed between the scapulae as well as an optional perpendicularly placed shoulder roll are used to achieve dorsal decubitus patient positioning. RESULTS: One hundred five flaps were performed during the study period, and dorsal decubitus positioning was used in all cases. Eighty-four flaps were free and 21 were pedicled. Indications for reconstruction included cancer resection (n = 58), trauma (n = 32), infection (n = 9), and others (n = 6). A simultaneous 2-team approach was carried out in 70 cases. Major complications included 9 cases of arterial or venous thrombosis/insufficiency, 2 of which resulted in total flap failure. Intraoperative conversion to lateral decubitus positioning was never required. CONCLUSIONS: Dorsal decubitus harvesting for subscapular-based flaps is a practical and effective technique that enables a simultaneous 2-team approach in complex reconstructive cases. Previous limitations of these highly versatile flaps, such as the need for intraoperative patient repositioning, can thus be avoided. This approach is employed for all subscapular-based flap reconstructions performed by the senior author.