The importance of developing relevant animal models to assess existing and new materials

Abstract

Purpose of reviewWe summarize the recent literature on the use of different animal models for testing existing and new materials for treatment of pelvic organ prolapse. Recent findingsA wide spectrum of animal models is being used in urogynecology, both for the study of physiologic and pathophysiologic processes, training in surgical procedures, yet mainly to study the host response to implant materials. The quality of studies is variable, and procedures, read-outs, and reporting are not standardized. This makes comparison very difficult. The research community is experimenting with different knitting patterns, novel polymers, bioactivation, as well as resorbable rather than durable implants. Outcomes of the experiments are dependent on the location of implantation. Lighter polypropylene constructs seem to induce a less vigorous host response than elder heavier products. Modification of the surface yields contradictory findings. Resorbable acellular collagen matrices may be reintroduced as prophylactically inserted support structures. SummaryAlthough animal experimentation with novel candidate implants is advocated, there is a lack of standardization in reporting. The concept of resorbable construct is being revived, as durable materials have caused clinical graft-related complications. Large animal experiments seem to provide interesting and more comprehensive information, yet their use may be contested.

Animal experimental research assessing urogynecologic surgical mesh implants: Outcome measures describing the host response, a systematic review and meta‐analysis

“…Meta‐analysis could only include 11% of the outcomes due to the infrequent and qualitative nature of outcome reporting. We, therefore, conclude that animal studies on host response after vaginal mesh surgery are highly heterogeneous, confirming previous observations in narrative reviews 16,17 …”

“…We, therefore, conclude that animal studies on host response after vaginal mesh surgery are highly heterogeneous, confirming previous observations in narrative reviews. 16 , 17 …”

Rabbit as an animal model for the study of biological grafts in pelvic floor dysfunctions

“…Rats 32 – 40 were used; however, due to its small body size studies at vaginal level are very difficult to be performed. The same for mice 18 , where most studied materials are implanted subcutaneously, rather than vaginally 41 – 43 .…”

“…Published studies show that several models can be used, and there is no animal that is perfect for this purpose. Each one has its own benefits and weakness 16 – 18 .…”

“…Other animals have a reproductive and urinary pathophysiology more similar to humans than rabbits, such as ewes or NHP 16 – 18 . These models would probably be better for studying the physiology of POP or UI.…”