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.

Pulmonary Artery Sealing Using the HARMONIC ACE+ Shears for Video-Assisted Thoracoscopic Surgery Lobectomy.

BACKGROUND: The standard technique for pulmonary arterial (PA) branch sealing in video-assisted thoracoscopic surgery lobectomy consists of vascular endostaplers. We evaluated the immediate efficacy of an ultrasonic energy vessel-sealing device for sealing PA branches and compared it with the gold standard (endostapler) in an ex vivo model. METHODS: This was a prospective cohort study. Immediately after anatomical lung resection, PA vessel sealing was achieved using the HARMONIC ACE+ Shears (ACE; Ethicon, Cincinnati, OH) sealing device or a vascular endostapler (VES) in a 3:1 ratio based on vessel diameter. The vessel was slowly pressurized, and the bursting pressure was recorded. RESULTS: A total of 137 PA branches were sealed in specimens from 43 patients, of which 90 vessels were sealed with ACE and 47 were sealed with VES. The mean PA branch diameter was 6.0 mm (range, 1.7 mm to 24.0 mm; standard deviation, 3.1 mm Hg). The mean bursting pressure was 333.0 mm Hg (range, 84.0 mm Hg to 1415.1 mm Hg; standard deviation, 231.4 mm Hg) in the ACE group and 114.2 mm Hg (range, 0 mm Hg to 840.0 mm Hg; standard deviation, 124.7) in the VES group (p < 0.001). There were no complete sealing failures in the ACE group. Electron microscopy of ACE-sealed PA vessels demonstrated adventitial sealing with partial preservation of the collagen bundles and media with a sealed matrix of melted collagen. CONCLUSIONS: PA branches sealed using the HARMONIC ACE+ in a simulated ex vivo model were able to sustain high intraluminal pressures. ACE-sealed vessels burst at mean bursting pressures equal to or greater than the VES-stapled vessels.

The double capsules in macro-textured breast implants.

Breast implants are amongst the most widely used types of permanent implants in modern medicine and have both aesthetic and reconstructive applications with excellent biocompatibility. The double capsule is a complication associated with textured prostheses that leads to implant displacement; however, its etiology has yet to be elucidated. In this study, 10 double capsules were sampled from breast expander implants for in-depth analysis; histologically, the inner capsular layer demonstrated highly organized collagen in sheets with delamination of fibers. At the prosthesis interface (PI) where the implant shell contacts the inner capsular layer, scanning electron microscopy (SEM) revealed a thin layer which mirrored the three-dimensional characteristics of the implant texture; the external surface of the inner capsular layer facing the intercapsular space (ICS) was flat. SEM examination of the inner capsule layer revealed both a large bacterial presence as well as biofilm deposition at the PI; a significantly lower quantity of bacteria and biofilm were found at the ICS interface. These findings suggest that the double capsule phenomenon's etiopathogenesis is of mechanical origin. Delamination of the periprosthetic capsule leads to the creation of the ICS; the maintained separation of the 2 layers subsequently alters the biostability of the macro-textured breast implant.