Breast Implant-associated Double Capsules: What Do We Know So Far? A Systematic Review of the Literature.

[INTRODUCTION] A double capsule is a recently described rare occurrence following breast implant placement in which an inner capsule envelope totally or partially adheres to the implant surface while a distinct outer capsule adheres to surrounding tissues, with an intercapsular space developing between the two. The objective of this study is to review all available literature related to formation of double capsules and propose a treatment algorithm.

[METHODS AND MATERIALS] A systematic review of the literature was conducted using Embase, Medline, and Cochrane databases. Articles reporting management of breast implant-associated double capsules were included in this review.

[RESULTS] A total of 9 studies (68 implants) were included in the review. 94.1% of double capsules occurred with textured Biocell shaped and round implants independently from implant pocket (p value=0.64). In all cases, double capsules were diagnosed fortuitously intra-operatively for another surgical indication. Capsular contracture was present in 50% of double capsules patients and was the most common indication for secondary breast surgery, 81.5% of which being clinically evident (p value<0.001). Treatment consisted in 84.4% in an inner capsulectomy with smooth implants exchange, and management of the outer capsule as per the capsular contracture algorithm.

[CONCLUSION] Double capsule formation is caused by delamination of a tight adhering capsule to a textured implant surface into two layers and continuous micro-shearing forces, and the probable contribution of bacterial biofilm. The only treatment reported so far includes inner with or without outer capsulectomy with smooth implant exchange.

[LEVEL OF EVIDENCE III] This journal requires that authors assign a level of evidence to each article. 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 .