| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Original Research |
1 Department of Radiology, Thomas Jefferson University Hospital, 396C Main
Bldg., 111 S 10th St., Philadelphia, PA 19107.
2 Present address: Department of Radiology, Galway University Hopital, Newcastle
Rd., Galway, Co. Galway, Ireland.
3 Present address: Department of Radiology, Hospital of the University of
Pennsylvania, Philadelphia, PA.
Received October 17, 2007;
accepted after revision November 29, 2007.
Address correspondence to D. Bergin
(dianebergin{at}yahoo.com).
Abstract
 Top Abstract IntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
MATERIALS AND METHODS. Contrast-enhanced pelvic 1.5-T MRI was performed in 49 women before and after UAE over a 2-year period. Dominant (largest diameter) fibroids in intramural, submucosal, subserosal, pedunculated subserosal, and endocavitary locations were assessed on pre- (baseline) and postembolization MRI. Size, locations of dominant fibroids relative to endometrium and serosa before and after embolization were compared. The ratio between the largest endometrial interface and the maximum dimension of the dominant submucosal fibroid (interface–dimension ratio) was determined on baseline MRI. The infarction rate for dominant fibroids was estimated after UAE.
RESULTS. One hundred forty dominant fibroids were identified on baseline MRI. Forty-nine (35%) were intramural, 39 (28%) were submucosal, 34 (24%) were subserosal, eight (6%) were pedunculated subserosal, and 10 (6%) were endocavitary in location on preembolization MRI. After UAE, of 39 dominant submucosal fibroids, 13 (33%) became endocavitary: complete (n = 4), partial (n = 9) on the basis of European Society of Gynaecological Endoscopy (ESGE) classification. The preembolization mean interface–dimension ratio and mean diameters for dominant fibroids that became endocavitary were significantly greater than for those that did not become endocavitary after embolization (0.65 vs 0.32, p < 0.005; 8 vs 5.4 cm, p < 0.05, respectively). All dominant submucosal fibroids showed 100% infarction after UAE.
CONCLUSION. Submucosal fibroids with an interface–dimension ratio of greater than 0.55 are more likely to migrate into the endometrial cavity after UAE. The majority of these are expelled spontaneously without significant symptoms. Rarely, submucosal fibroids greater than 6 cm in size that become endocavitary may cause postprocedural complications requiring further intervention and medical treatment.
Keywords: embolization • fibroids • MRI • uterine artery
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
Pretreatment evaluation of a patient with suspected myomas by means of pelvic MRI includes determining size, location, and contrast enhancement of uterine fibroids as well as coexistent or alternative unsuspected pelvic abnormality. This pretreatment assess ment has improved patient selection and reduced treatment failure or potential complications such as pyometrium, acute endometritis, ischemic injuries, and expulsion of submucosal fibroids [8–13]. Pedunculated subserosal fi broids with a narrow pedicle may slough off, becoming a potential source of infection in the peritoneal cavity. After UAE, submucosal and endocavitary fibroids may be associated with symptoms including pain, bleeding, infection, and vaginal discharge for prolonged periods of time [14–19]. Spontaneous expulsion of infarcted fibroids has been described after childbirth, laparoscopic uterine artery occlusion, and UAE. The rate of fibroid expulsion after UAE has been estimated to be 3% to 12% [16, 17].
We have noted that fibroids deemed to be submucosal on preembolization MRI may become endocavitary after embolization. We found no published data evaluating the imaging features of submucosal fibroids on preprocedural imaging that may predict increased risk of the fibroids becoming endocavitary after treatment. The purpose of our study was to retrospectively assess the change in location of dominant fibroids relative to the serosa and endometrium before and after UAE and to assess what factors determine which submucosal fibroids may become endocavitary after UAE.
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
Before UAE, a complete gynecologic examination and clinical evaluation were performed by the referring gynecologist. All women had documented negative results of cervical Pap smears. Endometrial biopsies performed for abnormal uterine bleeding in 19 of 49 women were also negative. Fifteen women who received hormonal therapy before UAE discontinued it at least 6 weeks before embolization. The majority of women (n = 38/49, 78%) had pelvic sonography performed at an outside facility before being referred for UAE; these images were not available for review.
Initial assessment by the interventional radiologist included a written patient questionnaire recording the women's baseline clinical symptoms [20]. All women had contrast-enhanced pelvic MRI approximately 1–2 months before UAE (mean, 36 days; range, 15–65 days). Contrast-enhanced pelvic MRI was routinely performed after UAE in all women (range, 40–140 days; mean interval, 125 days). Clinical follow-up for each woman was obtained through health records maintained by the treating interventional radiologist; telephone correspondence with referring physicians; and, in some cases, directly with the patient. Recurrence was defined clinically as recurrence of symptoms or anatomically with an increase in fibroid size or detection of new fibroids by imaging.
Embolization Procedure
One radiologist with 8 years of experience in interventional radiology
performed UAE in all women. Informed consent was obtained from each woman
after all risks associated with the procedure were explained. UAE was
performed in the following manner. Conscious sedation was achieved with
midazolam (Versed, Roche Laboratories) and fentanyl citrate (Fentanyl,
Elkins-Sinn). The patient's right groin was prepared and draped using a
sterile technique. Lidocaine hydrochloride 2% plain (Xylocaine, Laboratoire
Roger Bellon) was used for local anesthesia. The right common femoral artery
was the preferred approach for access in all women. Bilateral selective
uterine artery catheterization was performed using a 3-French Renegade
microcatheter (Boston Scientific/Medi-tech) and a 70° angled tip guidewire
that were passed coaxially through a 4-French Cobra catheter (Cordis, Johnson
& Johnson). Digital subtraction arteriography was performed. Embolization
was performed by using either 500- to 700-µm polyvinyl alcohol (PVA)
particles (Contour, Boston Scientific) or 500- to 700-µm tris-acryl gelatin
microspheres (Embospheres, Biosphere Medical), as determined by the performing
inter ventional radiologist, with the end point being stasis or near stasis in
the artery and with no large uterine artery branches remaining patent. All
women tolerated the procedure well and there were no com pli cations. After
the UAE procedure, each woman remained in the hospital at bedrest for 6 hours
and a majority were discharged the same day.
Pre- and Postembolization MRI
MRI was performed with a 1.5-T superconducting unit (Signa, GE Healthcare;
or Intera, Philips Medical Systems) using a pelvic coil. Sagittal
fat-suppressed and axial 2D fast spin-echo T2-weighted (TR range/TE range,
2,500–4,000/80–90) and spoil ed dual gradient-echo T1-weighted in-
and out-of-phase (120–200/2.3–4.6, 90° flip angle) MR images
were obtained. Parameters for 2D images included a section thickness of
5–6 mm with an intersection gap of 0–1 mm; matrix, 256 x
160–192; and field of view, 20–24 cm with one or two signals
acquired. Three-dimensional dynamic enhanced spoiled gradient-echo MR images
were obtained with 4-mm section thickness in 2.5-mm increments by using zero
interpolation; 4–6/2.1–3; 10–15° flip angle parameters;
matrix, 256 x 160; 0.5 signals acquired; and field of view, 24 cm.
Gadopentetate dimeglumine (20 mL) (Magnevist, Bayer HealthCare) was
administered IV by using a power injector at 2 mL/s followed by a 20-mL saline
flush. Breath-hold dynamic imaging was performed with initial acquisition
acquired immediately at the end of the saline flush and a second acquisition
immediately thereafter. Delayed contrast-enhanced imaging after approximately
3–5 minutes was performed using contiguous 5-mm-thick fat-suppressed 2D
single-section technique (TR/TE, 22/2; flip angle, 30°; matrix, 256
x 160; and field of view, 24 cm with one signal acquired in the sagittal
plane).
Review of MR Images
All MR images were evaluated in consensus by two radiologists with more
than 3 and 10 years of experience, respectively, in abdominal and pelvic MRI.
Images were reviewed without knowledge of the clinical history or findings at
embolization. Three-dimensional maximal measurements of the entire uterus and
fibroids were obtained on axial and sagittal planes using an independent
computer monitor with a PACS workstation. On preembolization (baseline) MRI,
the dominant fibroids, defined as fibroids with the largest dimensions, in
each of the following locations: intramural, submucosal, subserosal, and
endocavitary were identified and measured. Both the dominant pedunculated and
nonpedunculated subserosal fibroids when present were also measured. The
volumes of the entire uterus and dominant submucosal fibroid (in cubic
centimeters) were calculated on pre- and postembolization MRI by using the
formula for a prolate ellipse (length x width x depth x
0.5233). The relative difference in uterine and dominant submucosal fibroid
volume before and after embolization was calculated and expressed as a
percentage, as follows: 100 x [(Volume pre – Volume post) / Volume
pre], where Volume pre and Volume post are the volumes before and after UAE,
respectively.
A fibroid was defined as submucosal if any portion of the fibroid contacted the endometrium. A fibroid was defined as intramural when it was completely surrounded by myometrium. A fibroid was defined as completely endocavitary when surrounded by endometrium or partially endocavitary if greater than 50% of the surface area of the fibroid was surrounded by endometrium, in accordance with the European Society of Gynaecological Endoscopy (ESGE) classification [21]. A subserosal fibroid was defined as a fibroid with a partial or complete lack of surrounding myometrium and abutting or deforming the serosal layer. Pedunculated subserosal fibroids were defined as those with a pedicle diameter 50% narrower than the diameter of the fibroid.
|
After embolization, the same dominant fibroid in an intramural, submucosal, subserosal, and endocavitary location was reevaluated with regard to its location relative to the endometrium and serosa. These dominant fibroids were remeasured to assess change in size after embolization. The extent of postembolization dominant fibroid infarction was subjectively rated as 100%, 50% to 100%, and less than 50% of the total fibroid volume on contrast-enhanced T1-weighted images. We defined devascularization (infarction) of the fibroid if the signal intensity on unenhanced and contrast-enhanced MR images was similar, indicating no enhancement.
Statistical Analyses
To assess the difference in total uterine volume before and after UAE,
dominant submucosal fibroid volume, dominant submucosal fibroid size,
interface–dimension ratio, and paired Student's t tests were
performed. Statistical analysis was performed using software (Excel 2003,
Microsoft); p values of less than 0.05 were considered statistically
significant.
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
Of 140 dominant fibroids examined, 49 (35%) were intramural, 39 (28%) were submucosal, 34 (24%) were subserosal, eight (6%) were pedunculated subserosal, and 10 (7%) were endocavitary in location on preembolization MRI. The distribution and maximum dimension of the dominant fibroids before and after embolization are shown in Table 1. The mean reduction in volume of dominant submucosal fibroids was 53% (range, 18–100%) from 541 to 254 cm3 (p < 0.001) and of overall uterine volume was 40% (range, 18–62%) from 615 to 363 cm3 (p < 0.001), when pre- and postembolization MRI examinations were compared.
|
Of 39 dominant submucosal fibroids identified on preembolization MRI, 13 (33%) became endocavitary (complete [n = 4] or partial [n = 9]) after embolization (Table 2). The mean interface–dimension ratio on preembolization MRI of dominant submucosal fibroids that subsequently became endocavitary whether complete or partial was 0.65 (range, 0.55–0.83), which was significantly greater than the interface–dimension ratio of the submucosal fibroids that did not become endocavitary, 0.32 (range, 0.10–0.47; p < 0.005) (Table 3). The mean diameter of dominant submucosal fibroids on preembolization MRI that became endocavitary was 8 cm (range, 3–17 cm) greater than the diameter of submucosal fibroids that did not become endocavitary, 5.4 cm (range, 1.6–12 cm; p = 0.03). The mean preembolization interface–dimension ratio for dominant submucosal fibroids that became completely endocavitary after UAE was higher, 0.81 (range, 0.76–0.83) than for those that did not (Fig. 2A, 2B). The mean preembolization interface–dimension ratio for dominant submucosal fibroids on baseline MRI that became partially endocavitary after UAE was 0.67 (range, 0.55–0.69) (Fig. 3A, 3B).
|
|
|
|
|
|
Two of 49 (4%) dominant intramural fibroids became submucosal after UAE (Fig. 4A, 4B). Two of 10 (20%) dominant endocavitary fibroids were not evident at postembolization MRI, likely secondary to spontaneous expulsion. There was no change in location of dominant subserosal and pedunculated subserosal fibroids between pre- and post embolization MRI. Forty-nine of 49 (100%) dominant intramural, 39 of 39 (100%) dom inant submucosal, 32 of 34 (91%) dominant subserosal, six of eight (75%) dominant pe dunculated subserosal, and eight of 10 (80%) dominant endocavitary fibroids were com pletely infarcted after embolization. Two of 10 endocavitary fibroids completely disappeared. Two of 34 (6%) dominant subserosal and two of eight (25%) dominant pedunculated sub serosal fibroids had partial persistent enhancement (Table 4).
|
|
|
Clinical Outcomes
Forty-five of 49 (92%) women had resolution of preembolization symptoms and
no significant postprocedural symptoms. Four (8%) of 49 had significant
post-procedural symptoms (menorrhagia, acute pelvic pain, or persistent
vaginal discharge). These four women had dominant submucosal fibroids on
baseline MRI that subsequently became endocavitary after embolization. The
mean preembolization interface–dimension ratio of these submucosal
fibroids on baseline MRI was 0.81 (range, 0.76–0.83), with a maximum
fibroid dimension range of 6–17 cm (mean, 12 cm). The mean reduction in
volume of these dominant submucosal fibroids that were both symptomatic and
endocavitary after embolization was 58% (range, 659–275 cm3;
p < 0.001).
One woman with a 12-cm dominant submucosal fibroid on baseline MRI with a preembolization interface–dimension ratio of 0.82 that became endocavitary and measured 11 cm after embolization reported persistent pelvic pain that required analgesic medication. Hysteroscopic removal of the endocavitary fibroid was advised, but she was subsequently lost to follow-up. A second woman with a 6-cm dominant submucosal fibroid on baseline MRI and a preembolization interface–dimension ratio of 0.83 complained of persistent vaginal discharge after embolization. Follow-up MRI showed that the submucosal fibroid was endocavitary and measured 5.5 cm. She was treated with antibiotics, although there was no documentation of fever and no organism was cultured. Her symptoms were alleviated after spontaneous expulsion of tissue fragments. Two women who had dominant submucosal fibroids measuring 16 cm and 17 cm with preembolization interface–dimension ratios of 0.81 and 0.76, respectively, complained of persistent pelvic pain and heavy menstrual bleeding. In both, the submucosal dominant fibroids seen on baseline MRI were endocavitary, measuring 11 and 16 cm on post-embolization MRI follow-up. One of these patients refused further treatment and was discharged on antibiotics. The other patient had hysteroscopic myomectomy for a necrotic endocavitary prolapsing fibroid with subsequent resolution of symptoms (Fig. 5).
|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
Pretherapeutic imaging is important to define the location of uterine fibroids before UAE [9, 25–27]. MRI has excellent tissue contrast and its multiplanar capabilities allow precise definition of fibroid location. The use of IV contrast media allows accurate assessment of the vascularity of fibroids. Because of the large field of view, MRI also allows comprehensive assessment of the remainder of the pelvic contents [24–27]. Central fibroids frequently obscure visualization of the endometrium at sonography making accurate localization of fibroids relative to the endometrium difficult. MRI has therefore become the imaging technique of choice for assessing the myomatous uterus before embolization. Prior studies report additional pelvic abnormalities detected on MRI in 2% of patients [24]. This is similar to our patient group, 2% of whom had adenomyosis.
In our study, the dominant fibroid in a submucosal location constituted 28% of all the dominant fibroids; this is a higher proportion of submucosal fibroids than the reported incidence of 11% [27]. This increased incidence in our group is also reflective of a symptomatic group of women, all of whom had failed conservative treatment. Although successful UAE leads to necrosis of submucosal fibroids, the pretreatment loca tion of these necrotic fibroids can lead to additional symptoms and potential complications after treatment.
Complications of UAE are infrequent; however, 2% to 3% of women may expel small pieces of fibroid tissue after UAE [12, 17]. This is more commonly associated with submucosal and endocavitary fibroids [8, 17]. Thinning of the myometrium after embolization results in changes in fibroid location relative to the endometrium and serosa [11, 22, 23]. Submucosal fibroids after embolization can communicate with the endometrial cavity because of sloughing of the overlying endometrium. Communication of a cavitating necrotic submucosal fibroid with the endometrial cavity can result in prolonged vaginal discharge of necrotic tissue and vaginal bleeding [8, 12, 28]. Spies et al. [12] reported fibroid tissue passage as the most common reason for hospital readmission after UAE. Although many endocavitary fibroids are expelled spontaneously, some remain firmly attached to the uterine wall and require dilation and evacuation, transfusion, hysteroscopic myomectomy, and possible dilation and curettage or hysterectomy [13].
In our study, we observed that submucosal fibroids on baseline MRI with an interface–dimension ratio of 0.55–0.83 (mean, 0.65) and maximum dimension of 3–17 cm (mean, 8 cm) are more likely to become endocavitary after UAE. Of those patients who had submucosal fibroids that became endocavitary, a small group with preembolization submucosal fibroids with a mean interface–dimension ratio of 0.81 (range, 0.76–0.83) and maximum fibroid dimension 6–17 cm (mean, 12 cm) had significant symptoms. Smaller submucosal fibroids that become endocavitary are likely expelled without significant symptoms. Rarely, however, larger fibroids that do become endocavitary can lead to postprocedural complications [9]. We found that 33% (13/39) of dominant submucosal fibroids became endocavitary and four of these women (4/13, 31%) had significant symptoms on follow-up. One of these women required hysteroscopic resection of endocavitary fibroids. We also noted that 4% (2/49) of dominant intramural fibroids changed location after UAE and were submucosal on follow-up MRI. This thinning or loss in volume of myometrium after embolization is similar in mechanism to the secondary effect of UAE described on the junctional zone and as a potential treatment for adenomyosis [29]. A change in location of fibroids after UAE that is appreciable on follow-up MRI therefore has potential clinical significance for the patient.
We acknowledge the following limitations of our study. This was a retrospective study with a small patient group. Nonetheless, to the best of our knowledge, the results of this study describe for the first time the importance of the relative interface between a submucosal fibroid and the endometrium on baseline MRI and the subsequent post-embolization risk of becoming endocavitary, potentially increasing patient morbidity. Ideally the relationship of the sub mucosal endometrial interface relative to fibroid volume would be more accurately assessed by determining the endometrial surface area of the fibroid. However, lack of endometrial cavity distention limits assessment of the true surface area of a submucosal fibroid.
We believe that the largest endometrial interface (the interface–dimension ratio) on multiplanar images relative to the corresponding largest dimension of the submucosal fibroid has the greatest reproducibility and on a practical basis is more easily achieved during routine interpretation in a busy radiology practice. Future prospective studies can address the potential role and utility of 3D volumetric analyses. Also, because all of the women had multiple fibroids, it was not practical to analyze each individual fibroid. Small submucosal fibroids are likely to become endocavitary but would likely be expelled spontaneously without significant symptoms. In this study, we have shown that submucosal fibroids with an interface–dimension ratio greater than 0.55 on baseline MRI may become endocavitary after embolization. The majority of these did not cause significant postprocedural symptoms. Submucosal fibroids greater than 6 cm in size that become endocavitary had a higher association with significant symptoms requiring further treatment or intervention.
In conclusion, in this pilot study we found that submucosal fibroids with an interface–dimension ratio on preprocedural MRI of greater than 0.55 are more likely to migrate into the endometrial cavity. The majority of these do not cause significant additional symptoms. Larger submucosal fibroids greater than 6 cm that become endocavitary can occasionally lead to postprocedural complications requiring further intervention and medical treatment.
Acknowledgments
We thank Marianne Hamel, Department of Pathology, for her pathology
assistance.
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
This article has been cited by other articles:
|
|
 |
|
  F. Burbank Are Fibroids That Become Endocavitary After Uterine Artery Embolization Necessarily a Complication? Am. J. Roentgenol., May 1, 2008; 190(5): 1227 - 1230. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
