The biology behind fascial defects and the use of implants in pelvic organ prolapse repair

Abstract

Implant materials are increasingly being used in an effort to reduce recurrence after prolapse repair with native tissues. Surgeons should be aware of the biology behind both the disease as well as the host response to various implants. We will discuss insights into the biology behind hernia and abdominal fascial defects. Those lessons from "herniology" will, wherever possible, be applied to pelvic organ prolapse (POP) problems. Then we will deal with available animal models, for both the underlying disease and surgical repair. Then we will go over the features of implants and describe how the host responds to implantation. Methodology of such experiments will be briefly explained for the clinician not involved in experimentation. As we discuss the different materials available on the market, we will summarize some results of recent experiments by our group.

Porous Acellular Porcine Dermal Collagen Implants to Repair Fascial Defects in a Rat Model: Biomechanical Evaluation up to 180 Days

“…This is not without an impact on strength, as non-degraded Pelvicol implants are twice as strong as degraded Pelvicol implants of similar thickness (234. 4 Occasional degradation is in accordance with earlier experiments by Claerhout et al [18] and clinical experience [25] , and has remained unexplained so far. Possible 'local' factors such as infection or a poor batch quality were considered.…”

“…Animal models do not mimic the effect of live events leading to prolapse, nor can implants be exposed to similar physical forces present in patients [4] . Further, some species, like rabbits, have a difference in collagen metabolism which may interfere with the results [27] .…”

“…This way, the implants (2.0 ! 3.5 cm) had dimensions 0.25 cm larger than the defect in all directions ('overlay' technique) [4] . All materials were hydrated for 10 min in sterile saline prior to implantation.…”

“…The lifetime risk of undergoing operative repair for prolapse by the age of 80 is 11.1% with recurrence rates of up to 29% [1][2][3] . Due to the host's inherent insufficient connective tissue quality, the use of autologous tissue in pelvic organ prolapse repair may account for some of the high recurrence rate [4] . To reduce this, implant materials have been proposed because they may reinforce the weakened tissue by incorporation at the treatment site.…”

A preclinical evaluation of polypropylene/polylacticacid hybrid meshes for fascial defect repair using a rat abdominal hernia model

“…In line with previous studies examining several commercially available mesh types [20,21], both our new meshes and the PP meshes showed contraction at all time points. Common causes for pain and tissue erosion are mesh folding and contraction after implantation, hence this should be avoided in human surgery [22]. Biomechanical properties of explanted samples were analysed using uniaxial tensile testing.…”