Examples of anchoring systems

In vitro comparison of different anchoring systems used in pelvic floor surgery

Abstract: MP4-17

Ralf Anding, Ruth Tabaza, Ruth Kirschner-Hermanns Neurourology, University Hospital Bonn, Germany

Results

Comparison of 4 anchoring systems

Objectives Development of a method to compare different anchoring systems • comparing pull-out forces of different fixation systems with regard to shape, size, and material

• data of current systems are insufficient

1) Ballistic gelatine model

All anchoring systems were fitted with the same suture fixation (PP=polypropelene, PVDF=polyvinylidene fluoride) Mean retention forces in relation to PelFix ‘Surelift’ (PP)

‘MiniArc’ (PP)

Expectations

Anchor Miniarc

rectus

pelvic floor gelatine rectus gelatine rectus pelvic floor pelvic floor gelatine rectus gelatine rectus pelvic floor pelvic floor gelatine rectus gelatine rectus pelvic floor pelvic floor gelatine rectus gelatine rectus pelvic floor

pelvic floor gelatine

• no early dislocation intra- and postop.

• small size, preferably atraumatic

‘TFS’ (PP)

‘Pelfix’ (PVDF)

Surelift

rectus pelvic floor gelatine

TFS

• retention force > 32 N/cm

rectus pelvic floor

Schumpelick, J Minim Access Surg. 2006;2(3):117–123

gelatine

• retent. force of vaginal tissue < 21 N/cm Cosson, Eur J Obstet Gynecol Reprod Biol 2004;112(2):201-205

Photoelastic experiments to visualize 'stress profiles' of different anchoring systems

Pelfix

p 0.140 0.050 0.140 1.000 0.050 1.000 0.001 0.000 0.001 1.000 0.000 1.000 0.071 0.002 0.071 0.816 0.002 0.816 0.000 0.000 0.000 0.001 0.000 0.001

rectus pelvic floor gelatine

p values of the measurements

Examples of anchoring systems

TVT Secur

Ajust

TFS

‘MiniArc’ (AMS)

‘Surelift’ (Neomedics)

‘TFS’ (TFS Surgical)

‘Pelfix’ (FEG)

The isochromatic fringes in ballistic gelatine reflect the distribution of shear stress

2) Tissue testing (animal model)

Distribution of holding forces of 4 anchors F (N)

50 45 40

MiniArc

Surelift

PelFix (new system under development)

35 30

Gelatine Pelvic floor

25

Rectus fascia 20

Testing in a ballistic gelatine model

15 10

Anchor pull-out tests in a finalized pig with a Newtonmeter (Sauter FK50, 50 N/0.02N)

3 pull-out tests were performed with each anchor in the rectus fascia, the mesentery, and in different structures of the pelvic floor

5 0

MiniArc

Surelift

TFS

PelFix

Holding forces in different structures 1,2 1 0,8

Staat, Measurement to compare soft tissue anchoring systems in pelvic floor surgery. J Biomed Mater Res 2012;100B(4):924–933 ORF

SOL

AV

PF1

PF2

SUR

TFS

Ausreißkraft [N]

N=5

N=5

N=1

N = 15

N = 16

N = 15

N =15

Becken 0,4

MA

60 N = 15

Rektusscheide

0,6

Gelatine

0,2

— Median ♦ Mittelwert N Anzahl

0

50

MiniArc

Rectus fascia

40

Mesentery

Surelift

PelFix

Relation of holding forces in different structures

30 Bauchdecke

Discussion

20

10

0

First test series with various anchoring systems in porcine rectus fascia

Sections of the broad ligament (sacrouterine ligament is missing in the pig)

• A comparison of different anchoring systems in a combined experimental setting is possible and reveals significant differences in holding capacity • Size matters but shape is paramount • The PelFix anchor demonstrates the best holding capacity in this setting