Animal models for preventing seroma after surgery: a systematic review and meta-analysis.

Novel interventions for seroma prevention are urgently needed in clinical practice. Animal models are pivotal tools for testing these interventions; however, a significant translational gap persists between clinical and animal model outcomes. This systematic review aims to assess the methodological characteristics and quality of animal models utilized for seroma prevention. A meta-analysis was performed to estimate the expected seroma incidence rate for control groups and determine the effect size of typical interventions. We systematically retrieved all studies describing animal models in which seroma formation was induced. Methodological characteristics, risks of bias, and study quality were assessed. Seroma volume and -incidence data were used for the meta-analysis. In total, 55 studies were included, with 42 eligible for meta-analysis. Rats (69%) were the most frequently used species, with mastectomy (50%) being the predominant surgical procedure in these models. Despite significant risks of bias across all studies, an improving trend in reporting quality per decade was observed. The meta-analysis revealed an average seroma incidence of 90% in typical control groups. The average intervention halved the seroma incidence (RR = 0.49; CI 0.35, 0.70) and significantly reduced seroma volume (SMD = -3.31; CI -4.21, -2.41), although notable heterogeneity was present. In conclusion, animal models for seroma prevention exhibit methodological flaws and multiple risks of bias. Implementing sufficiently powered positive and negative control groups could improve the internal validity of these models. More research is needed for further development of animal seroma models.