title: Comparison of the postoperative incidence rate of capsular contracture among different breast implants: a cumulative meta-analysis.
abstract: BACKGROUND
  A large number of clinical studies have reported that the different materials used in breast implants were a possible cause of the different incidence rates of capsular contracture observed in patients after implantation. However, this theory lacks comprehensive support from evidence-based medicine, and considerable controversy remains.
  
  
  OBJECTIVE
  In this study, a cumulative systematic review examined breast augmentation that used implants with textured or smooth surfaces to analyze the effects of these two types of implants on the occurrence of postoperative capsular contracture.
  
  
  METHODS
  We conducted a comprehensive search of literature databases, including PubMed and EMBASE, for clinical reports on the incidence of capsular contracture after the implantation of breast prostheses. We performed a cumulative meta-analysis on the incidence of capsular contracture in order from small to large sample sizes and conducted subgroup analyses according to the prosthetic material used, the implant pocket placement, the incision type and the duration of follow-up. Relative risks (RR) and 95% confidence intervals (CI) were used as the final pooled statistics.
  
  
  RESULTS
  This meta-analysis included 16 randomized controlled trials (RCTs) and two retrospective studies. The cumulative comparison of textured and smooth breast implants showed statistical significance at 2.13 (95% CI, 1.18-3.86) when the fourth study was entered into the analysis. With the inclusion of more reports, the final results indicated that smooth breast implants were more likely to be associated with capsular contracture, with statistical significance at 3.10 (95% CI, 2.23-4.33). In the subgroup analyses, the subgroups based on implant materials included the silicone implant group and the saline implant group, with significant pooled statistical levels of 4.05 (95% CI, 1.97-8.31) and 3.12 (95% CI, 2.19-4.42), respectively. According to implant pocket placement, a subglandular group and a submuscular group were included in the analyses, and only the subglandular group had a statistically significant pooled result of 3.59 (95% CI, 2.43-5.30). Four subgroups were included in the analyses according to incision type: the inframammary incision group, the periareolar incision group, the transaxillary incision group and the mastectomy incision group. Among these groups, only the pooled results of the inframammary and mastectomy incision groups were statistically significant, at 2.82 (95% CI, 1.30-6.11) and 2.30 (95% CI, 1.17-4.50), respectively. Three follow-up duration subgroups were included in the analyses: the one-year group, the two- to three-year group and the ≥ five-year group. These subgroups had statistically significant results of 4.67 (95% CI, 2.35-9.28), 3.42 (95% CI, 2.26-5.16) and 2.71 (95% CI, 1.64-4.49), respectively.
  
  
  CONCLUSIONS
  In mammaplasty, the use of textured implants reduces the incidence of postoperative capsular contracture. Differences in implant pocket placement and incision type are also likely to affect the incidence of capsular contracture; however, this conclusion awaits further study.
authors: Department of Plastic and Cosmetic Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China 400037.
authors: Xing
authors: X
authors: Liu
authors: Department of Health Statistics, College of Preventive Medicine, Third Military Medical University, Chongqing, China 400038.
authors: Liang
authors: L
authors: Zhou
authors: Department of Plastic and Aesthetic Surgery, Southwest Hospital, Third Military Medical University, Chongqing, China 400038.
authors: Fuqiang
authors: F
authors: Pan
authors: Department of Plastic and Cosmetic Surgery, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing, China 400042.
authors: Yang
authors: Y
authors: Gao
authors: Department of Plastic and Aesthetic Surgery, Southwest Hospital, Third Military Medical University, Chongqing, China 400038.
authors: Xi
authors: X
authors: Yuan
authors: Department of Plastic and Cosmetic Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China 400037.
authors: Dongli
authors: D
authors: Fan
mesh_terms: D018427:Breast Implants / Q000009:adverse effects*; D006801:Humans; D057910:Implant Capsular Contracture / Q000453:epidemiology* / Q000209:etiology; D015994:Incidence; D011183:Postoperative Complications / Q000453:epidemiology* / Q000209:etiology