Three-Dimensional Dynamic Prolapse Volume: A New Evaluation Tool for Pelvic Organ Prolapse
Article authors
12th Meeting of the Association of Academic European Urologists 5-8 December 2013, Paris, France
Relevance/importance of the topic:
Currently, the restoration of pelvic organ prolapse (POP) is mainly limited to the repair of anatomical defects. However, it is well established that surgical procedures based on anatomical repair are not always followed by sufficient functional outcomes. The use of pre-tailored mesh kits is based on their universal application in every compartment of every patient. However, there are a wide variety of pelvic floor defects causing different types of dysfunction. The widespread utilization of mesh resulted in an FDA alert on the occasional complications that are sometimes irreversible. Thus, there is a strong need for a complete multidimensional evaluation of POP to improve our knowledge of the anatomical aspects this condition and to provide a new approach for the treatment of these patients, which will lead to better functional outcomes.
Introduction & Objectives:
Pelvic organ prolapse (POP) is a condition that is well-understood in medicine. Several different therapeutic approaches have been suggested to treat this condition, largely based on the anatomical restoration of the descended compartments. In an effort to create an encoding tool that is useful to both the clinician and researcher, the Standardization Subcommittee of the International Continence Society created the Pelvic Organ Prolapse Quantification (POP-Q) system in 2002. The prolapse grading according to the POP-Q system is based on the estimation of the most prominent edge of the prolapse and its’ relationship to the plane of the hymeneal ring. The POP-Q system is significantly limited due to the two-dimensional measurements of the mid-saggital plane. The vast majority of alternative prolapse imaging techniques are expensive and in 2D.
This study presents a new potentially useful three-dimensional non-invasive tool for studying pelvic organ prolapse. The dynamic factors of the prolapse during rest and Valsalva were also evaluated.
Material & Methods:
We used a 3-D scanner to create a digital model of the pelvic floor at rest and during Valsalva. The study was approved by the local Ethics committee, and all patients signed informed consent. Patients suffering from pelvic organ prolapse in different compartments were included in the study. Patients suffering from stress urinary incontinence without prolapse were included in the study as controls. An Artec™ 3D portable scanner (Artec Group, Russia) was used to generate the 3D images. This scanner is similar to a video camera that captures 3D images. The scanner captures up to 16 frames per second. These frames are aligned automatically in real-time, which makes scanning fast and easy (figure 1).
All of scanning was performed as a part of a routine physical exam in a gynecological chair. All participants were scanned at rest and during Valsalva. Patients suffering from major-grade prolapse were also scanned after the repositioning of the prolapse. The image processing was performed with the Artec Studio 9.2 software (Artec Group, Russia). After the generation of the 3D model of the pelvic floor, the volume of the prolapsed vaginal wall was measured (figure 2). For the analysis of the dynamic features of the prolapse, we proposed a new term: dynamic prolapse increment (DPI), which is defined as a growth in the prolapse volume from rest to maximal Valsalva maneuver (DPI = (Vval – Vrest) / Vrest %). The total prolapse volume (TPV) was calculated as the change in the prolapse volume from repositioning with a speculum to stage 0 by POP-Q (a potentially optimal surgical restoration) to the prolapse at the maximal Valsalva maneuver (TPV = Vrep – Vval).
Figure 1. Artec 3D scanner.
Figure 2. Three-dimensional scanned images of the pelvic floor in a patient with POP. Blue surface, during Valsalva; yellow surface, at rest; and red surface, after the repositioning of the prolapse.
Results:
Overall, 72 women participated in this study. The mean age of the patients was 56-years old. Nineteen of the patients exhibited symptomatic pelvic organ prolapse. For patients without pelvic organ prolapse (53/72), the mean TPV was 9240 mm3 (from 270 to 26000 mm3), and the mean DPI was 26% (from 5 to 51%). Among patients with a POP-Q stage 1-2 prolapse, the total prolapse volume was 15600 mm3 (from 7400 to 24040 mm3). These data may increase our knowledge of normal pelvic floor movements.
During the evaluation of patients with a grade 3-4 prolapse, two groups of patient were identified. In the first group, the DPI suggested nearly a three-fold growth of the prolapse volume after straining (290%, from 125% to 437%). However, the stage of the prolapse was not changed significantly during the Valsalva maneuver. In the second group of patients, the DPI was only 48.,8% (with a range of 41% to 55%). The mean total prolapse volume was 50.875 mm3 and 64.892 mm3 in group 1 and group 2, respectively. In the first group, the increase in the prolapse volume was not related to the further descent of the most prominent point. Instead, the increase was caused by the enlargement of the other compartments, such as the cystocele or enterocele. This enlargement occurred in 3D manner and could not be validated using the POP-Q system because the most prominent edge remained at the same level and because all of the other relative points could only be estimated in the mid-saggital plane.
Conclusion:
New parameters for pelvic prolapse assessment allow for the assessment of additional valuable information regarding the different types of prolapse that might otherwise be equally graded by traditional classification systems. The three-dimensional evaluation of the pelvic floor with a 3D scanner is an easy and non-expensive tool for the future study of the anatomical features of prolapsed compartments. This method of evaluation allows the physician to assess the physiological mobility of the pelvic floor in different categories of patients as well as in in healthy volunteers. This information may aid in the development of surgical procedures that will avoid the overfixation of the prolapsed organs to decrease postoperative complications. In the future, a subsequent evaluation of the pelvic floor anatomy with respect to functional outcomes is necessary.
