Abstract
Background
Pelvic organ prolapse (POP) is a common disorder in elderly women often surgically repaired with alloplastic meshes; yet knowledge of the pelvic floor behavior and multi-compartment defects postoperatively is scarce.
Purpose
To evaluate the 1-year outcome after mesh repair in patients with POP using clinical examination (CE), dynamic magnetic resonance imaging (dMRI), and the prolapse quality-of-life (P-QOL) questionnaire.
Material and Methods
A prospective observational study was conducted of 69 women undergoing pelvic mesh surgery. Clinical examination, dMRI, and the P-QOL questionnaire were applied before and after surgery to evaluate POP. Mean outcome measures were POP outcome as determined on clinical and dMRI examinations and its impact on quality of life. Statistical results were obtained with SPSS version 15.0. ANOVA was used to compare pre-/postsurgical quality of life data.
Results
Sixty-nine women (mean age, 64.75 years; BMI, 26.75 kg/m2; postmenopausal, 89.2%) were recruited and treated with Seratom® or Perigee™ mesh implants. A significant improvement in the position of bladder neck, vaginal vault/uterus, pouch of Douglas, and rectum was found 12 weeks and 1 year after surgery using POP-Q scale and dMRI. Advanced cystoceles and enteroceles seem underestimated by CE using the POP-Q system compared to dMRI results (P = 0.003 and P < 0.001), vice versa dMRI overestimated POP compared to CE. Sixty-four women completed the P-QOL questionnaire, presenting reduced quality of life before surgery which improves postsurgically. Prolapse impact and physical, social, and role limitations correlated strongest with a low quality of life (P < 0.001).
Conclusion
The 1-year follow-up after mesh repair showed statistical and clinical improvement for all tools employed. dMRI seems a reliable tool for simultaneous assessment of defects in all three compartments, but tends to overestimate POP compared to clinical examination.
Introduction
Pelvic organ prolapse (POP) is a common female disorder frequently causing severe decrease in quality of life often calling for gynecologic surgery (1–3). In the United States, POP leads to over 300,000 surgical procedures per year, including a reoperation rate of 30% (4–6). The lifetime risk for prolapse surgery by the age of 80 years is higher than 11%, with a peak incidence of surgical treatment between 60 and 69 years of age (2,7).
The pelvic floor is a complex structure supporting bladder, urethra, uterus, cervix, vagina, and rectum. A wide range of possible pathologies seem obvious. Many advanced techniques for POP treatment are available (7). Unfortunately, 58% of the women undergoing POP surgery will experience recurrent prolapse during the first postsurgical year (8). Additional support can be provided by a mesh graft (9).
Most clinical studies on POP surgery have focused on the feasibility, morbidity, and anatomical results of mesh implantation. Unfortunately, long-term data and data on functional results are scarce (10,11). To avoid intraoperative complications or high recurrence rates, accurate pelvic floor assessment is essential when planning surgical reconstruction. In patients with complex pelvic floor disorders, clinical examination (CE) or ultrasound diagnostics may be insufficient, and further imaging seems useful. Transvaginal ultrasound is rapidly replacing radiological methods (12). Yet vaginal and transperineal ultrasound has its limits as it cannot adequately visualize all compartments at once. Pelvic dynamic magnetic resonance imaging (dMRI) might be an alternative method making simultaneous assessment of all possible compartments. Ultrafast T2-weighted sagittal MRI allows more detailed, non-invasive dynamic imaging, providing anatomic and functional information. Additionally, using high-resolution sequences makes visualization of damaged muscles and ligaments possible (13). Using defined reference lines is a reliable and simple method for assessing prolapse severity (13,14).
Besides these objective parameters, symptom severity and patient’s satisfaction have a fundamental meaning for both therapy and its future evaluation (3). Therefor the use of valid quality-of-life questionnaires is recommended (1,2).
The primary objective of this study was to evaluate the efficacy of mesh repair in patients with severe POP assessed using clinical examination and dMRI in a 1-year follow-up. In addition, the quality-of-life outcome and complications after surgery were documented.
Material and Methods
Between January 2008 and October 2009, patients with POP stage 3 or 4 according to the International Continence Society (ICS) or with symptomatic stage 2 who were candidates for surgical treatment were included in this prospective observational study (15). All patients gave their informed consent. The study was approved by the Institutional Ethic Committee (University of Heidelberg, S-473/2007).
The simplified version of the POP-Q scale, dMRI of the pelvis, and the German version of the Prolapse Quality-of-Life Questionnaire (P-QOL) were applied at each visit (before surgery, and 12 weeks and 1 year postsurgical) (1,3). All patients were examined by the same doctor with the Graves speculum in the lithotomy position. POP grading was documented during a Valsalva maneuver.
All patients underwent dMRI with moderately full bladder and additionally 10 healthy volunteers (premenopausal women with no prolapse found in routine CE, no history of vaginal deliveries) to confirm reliability of the dMRI (1.5 Tesla, Siemens Symphony, Siemens Medical Solutions, Erlangen, Germany). All images were obtained with suspended respiration in supine position.
The pubococcygeal line (PCL) was chosen as a reference line for the position of the bladder neck (BN), vaginal vault (VV), and pouch of Douglas (DP) (4,16). The midpubic line (MPL) was the chosen reference line for the position of the rectum (Fig. 1) (4,5,17). At the time of study development the PCL and MPL were most frequently described reference lines in dMRI (17). The dMRI did not involve bowel evacuation and there was no contrast placed into the rectum. During rest and maximal strain, BN, VV, DP, and rectum (most descendent point of the rectum) were identified, and the distance (descent) from the appropriate reference line was measured. A simple four-stage scoring system was used (Table 1) (16). All MR images were evaluated by two experienced radiologists blinded to the patients’ status.
Midline sagittal MRI (sag truFIST T2) of large cystocele under Valsalva maneuver and points of measurement; (a) measuring points of the bladder; (b) measuring points of the vaginal fornix; (c) measuring points of the pouch of Douglas; (d) measuring points of the anterior rectal wall. PCL is the line drawn from the inferior pole of the symphysis to the most inferior part of the coccyx; MPL is the line drawn through the longitudinal axis of the pubic bone and passing through its midequatorial point (4,17). b = line to measure bladder, f = line to measure vaginal fornix, p = line to measure pouch of Douglas, r = line to measure anterior rectal wall. Dynamic MRI scoring system in pelvic organ prolapse.
All operations was performed by the same surgeon experienced in complex pelvic floor surgery and performed as described by other authors (9). The meshes used were produced either by Serag Wiessner GmbH & Co. KG, Naila, Germany (Seratom E PA® mesh, transobturatory six arm approach, with or Seratom A PA® four arm approach without additional sacrospinous fixation; multiple use kits) or American Medical Systems, Inc., Minnetonka, MN, USA (Perigee™, Transobturator Anterior Prolapse Repair System; disposable kits) and implanted via anterior transobturator approach.
To assess the subjective effectiveness of mesh repair, the validated German P-QOL questionnaire was handed to patients at each visit. It contains 34 questions, of which 16 are grouped in nine domains related to particular aspects of life. Eighteen questions concern the major symptoms of POP. The evaluation of the questionnaire was performed according to Digesu et al. (1).
Statistical analysis was performed using the Statistical Package for the Social Sciences version 15.0 (SPSS Inc., Chicago, IL, USA). Descriptive statistics, Student’s t test, Wilcoxon test, U Mann-Whitney test, and Chi-square test were used to obtain results. ANOVA was used to compare pre- and postsurgical QOL data. Statistical significance was set at 5%.
Results
Sixty-nine consecutive women were recruited, underwent mesh repair, and participated in several follow-up examinations. The mean age was 64.75 years (age range, 39–83 years; SD, 10.36 years). All women were Caucasian, and the mean BMI was 26.75 kg/m2 (range, 19.53–47.26 kg/m2; SD, 4.86 kg/m2). Fifty-eight women (89.2%) were postmenopausal.
A preoperative POP-Q examination was performed in all 69 subjects. Four women were subsequently excluded from the study, two due to lack of compliance, one was diagnosed with bladder cancer, and one due to obesity (BMI = 48 kg/m2). The number of patients continuing the study was 65, equaling 100%. Sixty-two subjects (95.4%) returned for the 12-week postoperative visit. One-year follow-up data were acquired for 50 subjects (76.9%).
For the amount and localization of meshes applied, see Fig. 2. Prior hysterectomy had not been performed in 45 (69.23%) of the 65 evaluated patients. In these patients, the uterus was preserved in 26 (40%) patients. Vaginal hysterectomy was performed in 19 (31.1%) patients. Table 2 describes the concomitant procedures. The mean operation time was 97.4 min (range, 30–235 min; SD, 40.218). One bladder injury occurred and immediately sutured. No hemorrhage of more than 300 mL was recorded, as no rectal injuries were recorded. All patients recovered rapidly from the procedure with minimal complaints about pain. Two patients having an additional sling procedure needed to continue intermittent bladder catheterization. The inability to completely empty the bladder was resolved within 61 days. Two patients underwent renewed mesh surgery due to recurrent complaints of cystocele after anterior mesh without sacrospinous fixation and rectocele after posterior mesh within 1 year after surgery. One patient (1.5%) complained of dyspareunia at the 1-year follow-up. One (1.5%) mesh erosion occurred 2 months after surgery in a 78-year-old patient treated with a non-absorbable graft. The complication was managed with a partial anterior mesh resection under local anesthesia and intravaginal application of estrogen cream 0.1%. Dysuria resolved after surgery. Four (6.15%) patients developed de novo stress urinary incontinence after the procedure (all without simultaneous transvaginal sling), whereas two women (3%) with known pre-existing urinary stress incontinence remained stable.
Flow of participants through the trial. Table shows distribution of concomitant procedures during mesh implantation. miniArc®, Single-Incision Sling System (American Medical Systems, Inc.); TOT, transobturator tape (Serasis®/Serasis® PA, Serag Wiessner GmbH & Co. KG); TVT, transvaginal tape (Serasis®/Serasis® PA, Serag Wiessner GmbH & Co. KG).
Comparison of pre- and postoperative stages of all four compartments assessed in dMRI (Wilcoxon signed ranks test).
Comparison of pre- and postsurgical QOL in eight life domains (ANOVA). The lower the score, the better the patients’ QOL is.
Discussion
Treating POP is challenging due to its complicated and multifactorial etiology and due to lack of reliable, riskless, and efficient surgical treatment. Recently, polypropylene meshes were introduced to urogynecological surgery with heterogeneous early results.
Our aim was assessing the outcome after vaginal mesh repair at two critical points in time by means of clinical examination and dMRI. As shown by Sand et al., the majority of recurrences and mesh erosions occur within 1 year of surgery (4). Therefore 12 weeks and 1 year after mesh repair were chosen as follow-up periods.
Patients were assigned to mesh surgery according to CE results and QOL impact. dMRI revealed over 14% more defects than CE during pretreatment evaluation. In our study group dysfunction in the middle compartment was associated in most cases with pathology in neighboring compartments, especially the posterior wall, as shown by Gufler et al. (10,18). Maybe this caused the significant difference of enteroceles assessed in our study using these two methods (dMRI revealed 2.5 times more defects than CE). Due to the association of VV prolapse with prolapse of other organs conducting a comprehensive assessment of the entire pelvis with dMRI is important (13,19). Patients often develop a concurrent enterocele, best demonstrated while straining during dMRI (10,13). An enterocele poses a complex diagnostic challenge in CE, especially when multiple organs are involved, as it is often overlooked. dMRI seems to be ideally suited for preoperative characterization of this bulge, and also ideally suited to not oversee a possible intussusception. This is clinically very difficult to detect (20). Significant differences between CE and dMRI results seem to imply that the sensitivity in CE is lower. Despite the fact that the efficacy of diagnosing a cystocele based on both dMRI and CE is similar, dMRI enables detection of urethral hypermobility. In severe anterior wall defects, symptoms of stress incontinence may paradoxically be masked by kinking at the BN and may appear only when the bladder prolapse is repaired (13).
dMRI revealed a significantly larger number of anterior wall defects than CE in follow-up visits. This phenomenon might reflect physicians’ tendency to underestimate defects, due to both personal and patient’s satisfaction with the surgical outcome. A higher sensitivity of dMRI for diagnosing POP in all compartments apart from cystoceles suggests that this method might supplement shortcomings of clinical assessment systems. dMRI is a reliable tool, as far as accessible for urogynecologists, for decreasing the frequency of POP misdiagnosis, the rate of inappropriate surgical indication, or the number of unsuccessful repairs.
Although dMRI appears to be a very powerful device, radiological standardization is lacking and there is still a dearth of literature on the proper validation of dynamic pelvis MRI. We agree with Broekhuis et al. that there is a desperate need for a validated staging system in pelvic dMRI (7,19). Recently, Betschart et al. published their work on the PICS line (Pelvic Inclination Correction System) measuring the organ of interest in the line of gravity, correcting the pelvic inclination occurring during rest and strain (14). In the future, dMRI will hopefully improve POP evaluation and the POP-Q system may be employed more in MRI diagnostics, facilitating communication between radiologists and clinicians, but until then awareness of this problem is essential while evaluating dMRI results (21).
Recent studies have shown promising results for mesh repair especially in recurrent or advanced POP (4,7,9). When using surgical techniques involving permanent biomaterials, specific mesh-related complications (e.g. mesh erosion, infection, retraction) must be taken into consideration. Our surgical complication rate is comparable to those presented in other studies (9,11,22).
The anatomical cure rate was high, reaching 91.8% when assessed with the POP-Q scale 12 weeks after surgery and 94% at the 1-year follow-up being comparable to other published results (13). The higher overall cure rate at the 1-year follow-up may be associated with a – desired – physiologic remodeling process of the connective tissue around the implanted graft (23). The dMRI presented a cure rate of 66% increasing to 70.5% at the 1-year follow-up. In comparison to the study of Tayrac et al., the anatomic postsurgical outcome of our patients can be considered satisfactory (11).
As shown by Digesu et al. the P-QOL questionnaire is a trustworthy instrument in routine clinical practice and treatment follow-up (2,24,25). We found that the general impact of prolapse on a woman’s life was high before surgery despite their opinion of good or moderate general health perception. Women mostly complained about social life affection, such as problems with daily activities. Interestingly, we found no correlation between prolapse severity as assessed on dMRI or CE and its influence on particular quality-of-life domains. We could interpret this to mean that the numerical POP stage does not equate with a certain amount of QOL impact, Furthermore, the impact of the prolapse on sexual relations not only concerned patients aged less than 60 years but also older women, agreeing with epidemiological research by Patel et al. (26).
The significant improvement in overall QOL in our patients after 1 year supports the theory that QOL is an equally or even more important tool for outcome evaluation then just CE or dMRI. The patients’ QOL provides important information about success or failure of the selected method as the patient herself perceives it.
In our study, several parameters (mean age, postmenopausal status, risk factors) were comparable with those presented by other researchers studying patients with POP (2,9,22). Thus, we believe that the observed anatomic defects and the correlations with self-reported pelvic floor-related symptoms were reasonably representative in our population, making it possible to generalize our findings for women with severe prolapse. Although the POP-Q scale was created to be an objective method, CE of patients with POP still remains subjective. The use of dMRI as a very objective method of assessing POP has considerably contributed to the reliability of the present results.
There are limitations of this study. In the future it will surely be possible to increase the number of patients and the time of postsurgical evaluation to obtain a more detailed outcome assessment. Rectal injection of ultrasound gel and implementing an evacuation phase could possibly reveal more complex compartment defects. Our control group was not matched with the patient group regarding weight, menopause, and socioeconomic status. The effect of estrogen deficiency in postmenopausal women could be evaluated as it has unquestionable impact on pelvic tissue (16,27). Socioeconomic status was not assessed in the present study, but we are conscious that this factor might have a serious impact on the subjective assessment of postsurgical outcome. Furthermore, we are not oblivious to the fact that MRI is cost intensive and cannot easily be employed by every physician.
In conclusion, our data show that use of polypropylene meshes in POP surgery is an effective method and female pelvic dMRI is a very objective method for evaluating the pelvic floor. dMRI is a good supplement to CE and POP-Q scaling, excluding the subjective implications of POP. dMRI seems to be a powerful tool for simultaneously assessing multiple pelvic floor and multi-compartment defects, possibly simplifying interdisciplinary work in the future. Although delivering reliable results, standardization and an adequate review in the literature are still lacking. In addition, more practical experience in conducting dMRI is needed to prevent POP from being overstaged.
Footnotes
Acknowledgements
KAB received a research scholarship by the Medical Faculty of the University of Heidelberg, Germany, to complete this work.
Conflict of interest
KAB has received speakers’ honoraria from the company Serag Wiessner in the past of which no money was used to perform this trial. All other authors state that they themselves and their institutions have no conflict of interest.