Outcomes of Air Versus Saline-filled Breast Expanders: A Systematic Review and Meta-analysis

Background: Among the possible implant-based reconstructive strategies, the two-stage tissue expander-to-implant procedure is one of the most common options in patients not ideal candidate to direct-to-implant reconstruction. Recently, other filling options such as air or carbon dioxide (CO2) have been reported as alternative fill media than saline for tissue expansion. The aim of this systematic review was to qualitatively and quantitatively synthetize the available evidence on the topic. Methods: A systematic review and meta-analysis were conducted, and they were reported according to PRISMA guidelines. PubMed, Embase, and Cochrane Library databases were accessed. Only studies with a control group were included. Risk ratios for complications were assessed between breast tissue expanders filled with saline versus air. MINORS criteria were used for bias assessment. Results: Nine studies met inclusion and exclusion criteria and were included. They encompassed a total of 1954 patients and 3243 breasts. Pooled risk ratios in air-filled compared to saline-filled breast expanders were calculated: total complications 0.92 [95% CI: 0.67; 1.27, p=0.53], mastectomy flap necrosis 0.86 [95% CI: 0.65; 1.12, p=0.26], hematoma 1.07 [95% CI: 0.63; 1.84, p=0.80], seroma 1.26 [95% CI: 0.91; 1.76, p=0.16], infection 0.80 [95% CI: 0.61; 1.04, p=0.09], extrusion 1.38 [95% CI: 0.82; 2.32, p=0.23], readmission 0.96 [95% CI: 0.58; 1.60, p=0.88]. The mean difference in days needed to achieve final expansion between air-filled and saline-filled breast expanders was -27.59 [95% CI: -46.42; -8.78, p=0.004]. Conclusion: Air-filled expanders represent an alternative reconstructive option in the field of two-stage breast reconstruction. Despite limited by the only initial available evidence, they appeared to be safe and associated with a similar risk of complications compared to saline-filled expanders. However, they may enable faster postoperative expansion and fewer outpatient expansion visits compared to saline-filled expanders. 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.