Middle East Fertility Society Journal (2013) 18, 196–201
Middle East Fertility Society
Middle East Fertility Society Journal www.mefsjournal.org www.sciencedirect.com
ORIGINAL ARTICLE
Role of MR imaging in surgical planning and prediction of successful surgical repair of pelvic organ prolapse Ebtesam Moustafa Kamal *, Fatma M. Abdel Rahman Obstetrics & Gynecology, Department, Faculty of Medicine, Zagazig University, Zagazig, Egypt Received 15 January 2013; accepted 12 February 2013 Available online 9 May 2013
KEYWORDS MRI; Pelvic organ prolapse; Surgical repair
Abstract Objective: To determine the role of magnetic resonance imaging (MRI) in surgical planning for females with pelvic organ prolapsed (POP) and to determine the clinical utility of MR imaging in predicting successful surgical repair. Methods: Fifteen patients with different varieties of pelvic floor dysfunction and 15 nulliparous females as control subjects were studied by magnetic resonance imaging (static and dynamic). Intraoperative findings related to POP were correlated to MRI findings. In the symptomatic patients, magnetic resonance imaging was repeated within 6–12 months after surgery. Results: Preoperative MRI and operative findings showed a significant correlation in all types of prolapse, except rectocele. On the other hand preoperative pelvic examination and operative findings were significantly correlated for cystocele, rectocele and vaginal cuff prolapse (r = 0.75, P < 0.008). Preoperative magnetic resonance imaging added information that changed the management in 40% of symptomatic women. Postoperative magnetic resonance imaging showed normal pelvic floor in asymptomatic patients (n = 13). Abnormal imaging findings were found in patients with persistent postoperative or de novo complaints (n = 2). Conclusion: Magnetic resonance imaging can accurately localize pelvic floor defects, evaluate success or failure of surgical procedures, predict the need for more extensive reconstruction, and identify complications. 2013 Production and hosting by Elsevier B.V. on behalf of Middle East Fertility Society.
1. Introduction
* Corresponding author. Tel.: +20 966564445729. E-mail address:
[email protected] (E.M. Kamal). Peer review under responsibility of Middle East Fertility Society.
Production and hosting by Elsevier
Pelvic organ prolapse (POP) represents a significant diagnostic and reconstructive challenge for clinicians. Although physical examination should remain the predominant method for evaluation, in the setting of a large introital bulge, it may be difficult to differentiate by physical examination alone among cystocele, enterocele, and rectocele. Under-estimation or inaccuracy in addressing the clinical problem usually arises with uterine prolapse as the cervix and uterus often fill the entire introitus, leading to difficulty in the diagnosis of concomitant pelvic prolapse.
1110-5690 2013 Production and hosting by Elsevier B.V. on behalf of Middle East Fertility Society. http://dx.doi.org/10.1016/j.mefs.2013.02.002
Role of MR imaging in surgical planning and prediction of successful surgical repair of pelvic organ prolapse The presence of unexpected findings at the time of vaginal exploration adds to the complexity and time of the surgical repair. Inadequate diagnosis with lack of a thorough preoperative evaluation and staging of pelvic organ prolapse accounts for recurrent pelvic floor surgical interventions as symptoms recur in 10–30% of patients, and the cause of the problems often involves compartments of the pelvic floor that were not repaired initially. Therefore, pelvic imaging can provide an important extension of the physical examination. Cystocolpoproctography is the radiologic method of choice in the evaluation of the pelvic floor because all three pelvic compartments are analyzed simultaneously (1–3). However, it is limited by radiation exposure, contrast agent application, and invasive maneuvers. Ultrasound is approved for the diagnosis of bladder neck descent and urinary incontinence as a result of its wide accessibility and greater patient acceptability (4,5). However, it is operator dependent, requires experience, and resolution diminishes rapidly with increasing depth. Furthermore, vaginal vault prolapse, enteroceles, and rectoceles cannot usually be evaluated by this method. Fast MR sequences now allow for very quick, efficient, detailed, and reproducible evaluation of the three pelvic compartments in a single procedure without exposure to ionizing radiation. These sequences allow a series of 1-s breath-hold images to be obtained in either static or dynamic imaging. The excellent differentiation between soft tissue and fluid-filled viscera provides visualization of the musculofacial support and structures of the pelvic organs without contrast agent application (6). Goodrich et al. (7) report increased sensitivity using MRI in the evaluation of women who have symptoms after surgery for pelvic floor relaxation but without findings on clinical examination. Gulfler et al. compared dynamic MRI measurement results from patients with pelvic organ prolapse before and after surgical repair and concluded that Dynamic MRI can be used as a problem solving modality for those who have failed previous repair as it helped in the evaluation of persistent patient complaints after surgery and detects more defects than physical examination (8). The aim of this study is to determine the role of MR imaging in surgical planning for patients with pelvic organ prolapse and to determine the clinical utility of MR imaging in predicting successful surgical outcome after repair of pelvic organ prolapse. 2. Patients and methods This study was carried out in Royal Commission Hospital, EL Gubail Industrial City between Feb 2009 and October 2011. Fifteen women aged 35–68 (mean 55 years) with symptoms and/or physical findings indicating pelvic organ prolapse (group 1), another 15 asymptomatic nulliparous female volunteers matched for age, body mass index, and menopausal status (group 2) were included in this prospective study after giving informed written consent. Preoperative and (6– 12 months), postoperative examination with MRI for assessing the efficacy of surgical repair was performed for (group 1), Volunteers in group 2 were examined only once. For the patient group thirteen women had two or more children, and two women had one child. Four were premenopausal, and 11 postmenopausal.
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2.1. Clinical evaluation An experienced gynecologist evaluated all patients by means of detailed medical and surgical history, documentation of complaints, and physical examination. Patients were examined both in the left lateral decubitus position as well as in lithotomy. Examinations were performed at rest and at strain in both positions. Anal sphincter tone, anal sphincter defects, levator ani tenderness, defects, and degree of relaxation of the puborectalis were noted. In addition, compartment defects and specific organ prolapses were recorded but not graded. Paravaginal defects were identified according to the method described by Shull et al. This test utilizes a ring forceps directed toward the ischial spines along the arcus tendoneus fasciae pelvis to simulate replacement of the lateral support of the vagina. Reduction of anterior prolapse by this maneuver indicates a paravaginal defect. Intraoperative findings related to POP were also carefully recorded. 2.2. Imaging sequences MR images were acquired using the (General Electric, Milwaukee, WI) GE Horizon 1.5-T. Patients were positioned supine with knees and hips flexed to simulate a sitting position two sets of images are acquired in sagittal plane using the torso coil. The first set consists of 17–20 static sagittal and parasagittal images that cover the pelvis from the left to right side wall. Images are acquired in a sequence that lasts about 18 s. During this sequence, each image is acquired independently and each acquisition is 1 s in duration. Because of such fast acquisition, we find it unnecessary for patients to hold their breath. These images are used to assess anatomy and presence of any pathology and to select the midsagittal plane for the following dynamic set of images. From static images, a midsagittal slice is identified as the one with symphysis pubis and coccyx. This slice is imaged repetitively. This set is used to assess the degree of pelvic floor descent and pelvic organ prolapse. During acquisition of each cut, the patient is instructed to relax for the first image and strain with pelvic floor relaxed for the next 4–5 images. Patients were asked to evacuate the bladder 3–4 h before the procedure, and instructed to take in a deep breath . . . , blow it all out . . . , take another deep breath . . . , and push, as if she was having a baby (or a bowel movement)!!’’ This set of dynamic images takes 1 s per image. The total MR room time needed for such examination is about 10 min. No pre-examination preparation or instrumentation was used. The images were looped as a cine stack for viewing and measuring the relationship among the mobile pelvic organs and fixed anatomic landmarks. Static and dynamic images typically are acquired with a single-shot fast spin-echo (SSFSE) pulse sequence using a 128 · 256 matrix with TR = 4,000 ms, TE = 22.5 ms for static and 90 ms for dynamic image, 17 slices, 5-mm slice thickness, and field of view (FOV) = 28 cm (pixel resolution 2.19 · 1.09 mm). 2.3. Image analysis The pubococcygeal line (PCL) was used as a reference line for the pelvic floor, and defined as the line that joined the inferior border of the symphysis to the last coccygeal joint. It was drawn in midline sagittal resting image. The advantage of this reference line is that it can be easily drawn and reproduced in
198 all patients, and it is independent of the pelvic tilt. Moreover components of the pelvic floor support, such as the pubococcygeus muscle, attach along this line. The degree of descent of the organs within the three pelvic compartments can be evaluated as the vertical distance between the resting and strain positions of the urinary bladder base, the uterocervical/vaginal apex (in hysterectomized patients), and the anorectal junction in reference to PCL. Bladder base descent was taken as the inferior most margin of the bladder. Anorectal junction descent was defined as the junction of rectal ampulla with the proximal extent of anal canal, and defined as excessive if more than 3 cm on maximal strain. Uterocervical descent was visualized as the junction of the wide cervix with the narrowed vaginal canal immediately posterior to the bladder, and graded as (grade 1) below puboccocygeal line, (grade 2) to introitus, and (grade 3) to exterior. Normal value for the parameters was established with a volunteer group. Measurements were considered abnormal beyond mean ± 2 SD. A cystocele was defined as descent of the bladder base below the (PCL). A urethrocele was defined as rotational descent of the proximal urethra during straining that increased the angle of urethral inclination (defined as the angle enclosed by urethra and longitudinal body axis) greater than 30 from the vertical. A bulge of more than 3 cm between the extended line of the anterior border of the anal canal and the tip of the rectal descensus constituted a rectocele (3,4). A wide rectovaginal space or deep pouch of Douglas with the peritoneal contents with or without small bowel loops beyond the pubosacral line was considered enterocele. The interpretation of the images was performed by an experienced radiologist unaware of the result of clinical evaluation (see Figs. 1a and b). 2.3.1. Statistical analysis All patients underwent surgery for symptomatic POP with or without associated voiding dysfunction. After surgery, data from the initial examination, preoperative MRI, and operative findings (type and degree of POP) were tabulated and analyzed
Figure 1a Sagittal T2-weighted image of a 49 year old patient during pelvic strain with a cystocele and rotation of the urethra into the horizontal plane (arrow), indicating damage to the internal sphincter.
E.M. Kamal, F.M. Abdel Rahman
Figure 1b Sagittal T2-weighted image of the same patients after surgery showing normal appearance of the pelvic organs and floor.
using Pearson’s correlations of paired-samples to compare the differences between initial examination, MRI, and intraoperative findings. The intraoperative findings were considered the reference standard against which physical examination and MRI were compared. Statistical significance was assigned to a P value of less than 0.05. 3. Results The examination was well tolerated by all patients. All MR images were held technically satisfactory. On SSFSE image the fluid in the bowel, urine in the bladder, and pelvic fat have a bright signal, which allows clear delineation of the pelvic organs. There was highly significant differences in the positions of all the pelvic organs at rest and on straining between the symptomatic patients and asymptomatic volunteers. Mean values with standard deviations (SD) for the bladder base descent, uterocervical/vaginal apex descent, and anorectal junction descent, and angle of urtheral inclination before and after surgery (data not shown). For asymptomatic volunteers the bladder base and uterocervical junction were at or above the pubococcygeal line at rest and it descended to 2.3 cm and 2.5 cm, respectively below the line on straining. The anorectal junction was found to lie below the baseline in all positions but did not exceed 2.3 cm at rest, 3.3 cm on straining. After surgery all values were significantly modified (P < 0.01). A significant difference was seen between pre and post surgery measurements with respect to the distance descended (P < 0.01). All the patients except two were continent in the postoperative period. Preoperative MRI examination revealed 40 pelvic defects compared to 30 defects on preoperative physical exam. On preoperative MRI, vaginal vault prolapse (n = 5) or uterovaginal prolapse (n = 7), 12 cystocele and 2 cystourethrocele, 7 enterocele, and 3 rectocele were observed. Combined defects in all the three compartments were observed in ten patients. Pearson’s correlation of paired samples compared the operative findings with the preoperative pelvic examination and with the preoperative MRI findings. A significant correlation was found between the preoperative pelvic examination and
Role of MR imaging in surgical planning and prediction of successful surgical repair of pelvic organ prolapse the operative findings for cystocele (r = 0.61, P < 0.005), vaginal cuff prolapse (r = 0.75, P < 0.008).and rectocele (r = 72, p0.008). The preoperative pelvic examination did not correlate with the operative findings of uterine prolapse and enterocele. On the other hand, the comparison of the MRI and operative findings showed a significant correlation in all types of prolapse, except rectocele, as follows: cystourethrocele, R = 0.68 and P < 0.001; enterocele, r = 0.78 and P < .001; vaginal cuff prolapse, r = 0.75 and P < 0.008; and, uterine prolapse, r = 0.78 and P < 0.014 (see Figs. 2a and 2b). Thirteen (95%) patients had vaginal repair, while two (5%) had abdominal repair. Operative repairs included abdominal sacrocolpopexy (n = 2), bilateral sacrospinous vaginal vault suspension (n = 2) with retropubic urethropexy. Pubocervical sling in two patients. Paravaginal repair and enterocele repairs with cul de plasty were performed in nine patients, and perineorrhaphy was performed in five patients. Rectoceles were repaired by posterior colporrhaphy in eight patients. Of nine women without prior hysterectomy, four (44%) had concomitant vaginal hysterectomy. Dynamic imaging lead to changes in the initial operative plan in five (40%) of patients. Such alterations included three patients with chronic constipation and chronic lower abdominal pain in whom dynamic MR demonstrated enterocele one after vault prolapse and two after vaginal hysterectomy. All were managed by culdoplasty with posterior colporraphy of all facial defects adjacent to sigmoid and rectum for adequate repair. The operative plan was also altered in a 67-year-old female with urinary and fecal incontinence and a large cystocele. On dynamic MR, she was found to have compression of the rectum secondary to massive descent of the bladder, uterus and cervix. Her fecal incontinence was secondary to compression of the rectum by the prolapsing anterior viscera, which then resulted in fecal evacuation. This patient underwent total vaginal hysterectomy, culdoplasty, and anterior and posterior colporrhaphy and remains continent of both stool and urine. Lastly preoperative MRI exam identified one case of urethral hypermobility with anterior and superior rotation of bladder and
Figure 2a Cystocele and vaginal vault prolapse in a 74-year-old woman. (a) Sagittal T2-weighted image of the patient during pelvic strain shows a very large cystocele (arrow).
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Figure 2b Sagittal image of the same patient after surgical repair of the prolapse shows a very small residual facial defect containing a small cystocele (arrow).
urethra possibly due to the loss of intrinsic urethral sphincter integrity and anterior facial support of the bladder neck. In severe cases opposition of bladder and urethra will mask symptoms of incontinence. So management plan was changed to a pubocervical sling instead of retropubic urtheropexy for adequate repair (see Figs. 3a and 3b). After surgical repair one of the 15 patients had first-degree stress urinary incontinence without any pathologic findings on physical examination, MRI showed a small facial defect containing a small cystocele in this patient. 4. Discussion Clinical presentations of pelvic organ prolapse include uterovaginal prolapse, vaginal vault prolapse after hysterectomy,
Figure 3a Sagittal T2- weighted image in a 68-year-old woman during pelvic strain shows global pelvic floor weakness with a severe cystocele and more moderate descent of the uterus and rectum.
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Figure 3b Sagittal T2- weighted image of the same patient after surgical correction during pelvic strain shows only a minimal descent of the pelvic organs below the pubococcygeal line (arrows).
cystocele, rectocele, enterocele, and bladder floor descent. These symptoms are frequently associated with one another, and pelvic floor weakness often involves all three compartments. Patients may exhibit symptoms that are specific to one compartment, but 95% of the patients with pelvic organ prolapse examined using dynamic cystocolpoproctography turned out to have multiple coexisting compartment defects (9). Successful surgical treatment of pelvic organ prolapse involves repair of site-specific defects in pelvic floor support. An attention to anterior prolapse (cystourethrocele) without attention to the pelvic floor may predispose to an increased occurrence of postoperative enterocele, uterine prolapse, and rectocele. Furthermore, restoration of the normal pelvic floor anatomy facilitates pressure transmission to the proximal urethra, thereby improving results of anti-incontinence surgery. Therefore, accurate diagnosis of the coexisting abnormalities involving all components of the pelvic floor is essential in planning reconstructive procedures so that the risks of surgical failure, recurrent prolapse, and reoperation can be minimized (10). In the present study, preoperative dynamic MRI was compared and correlated with the results of the intraoperative findings. We found that MRI yielded a statistically significant correlation with the operative findings of cystourethrocele, enterocele, vaginal cuff prolapse, and uterine prolapse but did not correlate with the operative findings of rectocele. Similar results have been reported. Gousse et al. (11) showed that half Fourier, single shot turbo spin-echo MRI reliably detected POP, except for rectocele. The inaccuracy in diagnosing rectocele has also been reported by Lienemann et al. (12). It has been postulated that the anterior rectal wall has intermediate signal intensity on rapid sequence T2 weighted MRI that cannot be readily differentiated from the posterior wall when the rectum is empty because the rectal walls are collapsed, leading to underdiagnosis of rectocele because of poor visceral definition.
E.M. Kamal, F.M. Abdel Rahman Delemarre et al. (13) acquired one image each during squeezing and pushing in patients with rectoceles and indicated that noninvasive MRI in the prone position is incapable of detecting rectoceles. Opacification of the rectum could lead to better definition of the rectocele. We avoided this technique as it is invasive, also, it may introduce sonographic gel bubbles artifact. Significant correlations between the preoperative pelvic examination and operative findings of cystocele, rectocele and vaginal cuff prolapse were demonstrated in the current study. However, we could not show a statistically significant correlation between the preoperative pelvic examination and operative findings of uterine prolapse or enterocele. Enterocele is prolapse of the small bowel through the hiatus. Unlike cystocele, enterocele prolapses by invaginating the posterior vaginal wall. This is the most difficult diagnosis to make by physical examination compared to all other types of organ prolapse, especially when both enterocele and anterior rectocele are present. Difficulty in diagnosing any prolapse by dynamic MRI, but especially enterocele, is related to the finite size of the hiatus. In other words, a prolapsed organ with its bulk may prevent others from prolapsing thus leading to under diagnosis of the compressed pelvic organs. For this reason, it is better to have the bladder relatively empty during the study. In a prospective study using both MRI and dynamic cystoproctography in patients with POP, 15. The study aim was to evaluate the detection of enteroceles by these two modalities. In opposition to our study design, physical examination served as the reference point, revealing enteroceles in 43 of 55 patients with POP. MRI detected enteroceles in 49 of these 55, and dynamic cystoproctography was positive in 14 cases. Magnetic resonance colpocystorectography proved significantly superior statistically to physical examination and dynamic cystoproctography (14). Although MRI is currently and typically performed in the supine position, it has excellent results in the evaluation of pelvic organ prolapse and significantly enhances clinical patient assessment and management. Fielding et al. (15), Gufler et al. (8) studied the influence of the patient’s position, supine in MR examination and upright in cystourethrography. They found that with the exception of the posterior urethro–vesical angle, all structures of the pelvic floor remained stable in the supine as well as in the upright position. Another study found that posterior urethro–vesical angle was extremely variable among continent and incontinent women and has a little value in identification of significant pelvic floor weakness. The limitation to this study is the relatively low case numbers that could be explained by the prospective nature of this study, and the lack to standardize bladder volume during MR examination that could have an influence on the extent of bladder neck descent. In this study patients were asked to void 3–4 h before MRI study to achieve a bladder volume of 200–400 cc. In this study the original operative plan was changed in 40% of patients when the dynamic images were reviewed in a multidisciplinary conference in the context of the patient’s past history, presenting symptoms, and clinical examination. While previous reports have attempted to determine the ‘‘best test’’ for pelvic organ prolapse, the results of the present study suggest that MR imaging and clinical examination have unique strengths and complement each other. Despite, being very useful as a preoperative planning tool, imaging should
Role of MR imaging in surgical planning and prediction of successful surgical repair of pelvic organ prolapse not be routinely required in all patients undergoing evaluation for pelvic organ prolapse, but should certainly be considered in a failed surgery, and for those patients with symptoms of multi compartment involvement for whom a complex repair is planned. 5. Conclusion Dynamic MR imaging appears to be valuable in the preoperative evaluation and management of patients with pelvic organ prolapse. It can reliably detect which compartments of the pelvis are damaged, and provide complementary data which are useful in planning operative repair of complex and/or recurrent multi-compartmental pelvic floor defects. The results of dynamic imaging changed the operative management in 40% of patients. Also, dynamic MR imaging was useful in the postoperative follow-up of patients who underwent pelvic floor reconstruction. Moreover, it can predict success or failure of surgical procedures, and identify complications. References (1) Safir MH, Gousse AE, Rovner ES, et al. 4-Defect repair of grade 4 cystocele. J Urol 1999;161:587–94. (2) Hock D, Lombard R, Jehaes C, et al. Colpocystodefecography. Dis Colon Rectum 1993;36:1015–21. (3) Maglinte DDT, Kelvin FM, Hale DS, et al. Dynamic cystoproctography: a unifying diagnostic approach to pelvic floor and anorectal dysfunction. AJR Am J Roentgenol 1997;169:759–67. (4) Kaufman HS, Buller JL, Thompson JR, et al. Dynamic pelvic magnetic resonance imaging and cystocolpoproctography alter surgical management of pelvic floor disorders. Dis Colon Rectum 2001;44:1575–84.
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