In-vivo Force Sensing during Laparoscopic Sacrocolpopexy Vaginal Vault Manipulation

Objective: During laparoscopic sacrocolpopexy vaginal vault prolapse is repaired by restoring the anatomical state of
the vagina with a surgical mesh. A vaginal manipulator is placed inside the vagina to provide proper exposure to the surgeon for
fixation of the mesh on the vaginal surface and vault by laparoscopy. Vaginal vault manipulation is done manually by an assistant
and long operation times lead to fatigue and inconsistent application of tensioning forces. This work describes a novel force sensor
designed to be integrated in the vaginal manipulator to measure interaction forces between the vaginal vault and the manipulator.
Methods: A sterile and biocompatible way to use the sensor has been developed and tested. After receiving ethics committee approval
two first-in-woman studies have been conducted. Both the force and pose of the instrument were recorded. Results: In the first case,
average forces of 4.41 N were measured with a standard deviation of 2.42 N, the maximal force was 27.48 N. In the second case
the force was 10.87 N (mean), 7.36 N (std) and 47.28 N (max). No vaginal rupture occurred. Conclusions: Different forces coincided
with a different degree of prolapse which may cause differences in compliance. In order to draw proper conclusions about the
measured data, a total of thirty interventions will be recorded. Clinical Impact: Up to now, no previous research has quantified
these interaction forces. Quantifying these forces and providing feedback cues to the assistant is of particular interest, especially as
a means to avoid vaginal rupture due to over-tensioning.