By Paul Lohle
With more research being carried out into uterine artery embolization, the procedure has been found to be far more widely applicable than previously thought and only a few relative and absolute contraindications to it remain, writes Paul NM Lohle.
Embolization within the uterus is not a new procedure. Postpartum and postsurgical bleeding, ectopic pregnancy, trauma, cancer-related pelvic haemorrhage and arteriovenous malformations have been treated successfully with embolization in the past. More recently, in the early nineties, physicians from the Lariboisière hospital in Paris, France, began to perform hysterectomy for women with symptomatic fibroids. However, selective uterine artery embolization was carried out prior to hysterectomy. In their Lancet publication in 1995, the gynaecologist JH Ravina and the interventional neuroradiologist JJ Merland introduced uterine artery embolization as a standalone procedure, because patients experienced satisfactory symptom relief and refused the planned hysterectomy. The safety and efficacy of the procedure have been extensively studied and embolization is now an accepted minimally invasive treatment for uterine fibroids by the American Congress of Obstetricians and Gynaecologists, and worldwide.
A state-of-the-art fibroid practice demands a collaborative effort by the interventional radiologist and the gynaecologist, who must fully evaluate a patient before recommending embolization as a treatment for symptomatic fibroids. The consultation should include general and gynaecologic history and a physical examination. The patient should be properly counselled about the different treatment options in keeping with the patient’s best interests so that her preferences are taken into account and she has reasonable expectations of outcomes. Imaging with magnetic resonance imaging (MRI) should be used to assess the characteristics of all uterine fibroids present and any surrounding pathology in the pelvic region. Ultrasound is an acceptable alternative to MRI if carefully performed with quality equipment.
Embolization for symptomatic fibroids has been shown to be successful in the vast majority of patients. While we once thought that the indication for embolization of uterine fibroids was heavy menstrual bleeding in premenopausal middle-aged women only, we now also know that pain and bulk-related symptoms caused by fibroids (eg pressure, urinary frequency or retention, with or without hydronephrosis) are good indications to carry out the procedure. In addition, nowadays, under special circumstances, embolization can be offered to carefully selected postmenopausal women with fibroid-related bulk symptoms on the condition that malignancy is ruled out. In the past, interventional radiologist were advised not to embolize very large fibroids (>10 or 12cm), because of the extensive tissue necrosis that would result from the procedure and the increased risk of complications such as infection, abscess and sepsis. Patients with so-called “fast growing fibroids” were also wrongly advised to undergo surgery. It was widely believed that rapid growth was an indication for hysterectomy, because of the likelihood of sarcomatous change. However, in 1994 this was shown to be fallacious. Similarly, pedunculated subserous fibroids on a small stalk were considered dangerous and unsuitable for embolization, because of possible detachment of the fibroid that could cause serious abdominal infections and abscess formation demanding laparotomy with the possibility of bowel resection. Cervical fibroids, another class of uterine fibroids, were also considered resistant to uterine artery embolization, and this was based on limited data. Meanwhile, like other assumptions in the past, the above mentioned examples have been refuted and it has been shown that embolization can be successful in treating women with these conditions. Nevertheless, certain anatomic fibroid subtypes deserve special consideration, even though we know that fibroids (whether they are small, large or huge) and irrespective of their location (submucosal, intramural, subserosal or cervical) are eligible for embolization. One of the considerations to make is that in case of a huge fibroid burden, some authors have reported less shrinkage after embolization and less symptom improvement in these patients. Yet, there is no evidence that these patients are more likely to have post-procedural complications.
Pedunculated submucous/intracavitary fibroids are more likely to be expelled in the weeks and months after embolization. It is therefore important to counsel the candidate about the risk of fibroid expulsion if a fibroid is intracavitary or has a significant endometrial interface (ie, if the fibroid has a portion of its circumference touching the endometrium). Regarding pedunculated subserosal fibroids, at least two studies have found no instances of fibroid detachment with good clinical outcome and no complications. From personal experience, cervical fibroids can be treated successfully with 100% infarction by positioning the catheter tip selectively in the uterine artery branch supplying the cervical fibroid followed by selective fibroid embolization. Another subgroup of patients that may be considered for uterine artery embolization are those with fibroid-induced sub-/infertility (submucosal fibroids causing distortion of the uterus or reproductive tract) who are not candidates for surgery. However, there is no question that the decision as to whether embolization is the best choice in any given patient is complex. Although the evidence is still limited, for women who wish to become pregnant, embolization should not be the first-line treatment. The current general opinion is to perform embolization only in women who want to conceive, if the fibroids present are symptomatic and a simple surgical treatment of fibroids is not possible. Other circumstances in which embolization was discouraged in the past, was in women with symptomatic fibroids accompanied by adenomyosis, an intra-uterine device, previous pelvic irradiation and immunocompromised/HIV positive patients. Published data have demonstrated that it is unjustified to withhold the option of embolization for adenomyosis with or without fibroids. Uterine artery embolization in women with symptomatic fibroids and the intra-uterine device in place will not increase the risk of complications such as endometritis. Although based on limited data, HIV positive patients with symptomatic fibroids can be successfully embolized, but a CD4 count
To date, only few contraindications to uterine artery embolization remain. An absolute contraindication is current pregnancy. Therefore, pregnancy must be excluded in each patient prior to the procedure. Known or suspected gynaecologic malignancy is another absolute contraindication, like complex cystic ovarian masses, a patient with clinical signs of irregular bleeding suspected of an endometrial malignancy or leiomyosarcoma. On MRI, the leiomyosarcoma can be difficult to diagnose, but it often appears as a large heterogeneous mass in the uterus with areas of irregular and patchy contrast enhancement. Current uterine or adnexal infection is another contraindication to embolization. After treatment of the infection, the procedure can be performed safely. Women who refuse hysterectomy under any circumstances, are also perceived by some colleagues as unsuitable for the procedure. Most interventionalists prefer an informed-consent process in connection with any additional (surgical) intervention after uterine artery embolization, including a discussion with the patient.
Relative contraindications from the past that remain valid are contrast allergy, coagulopathy and renal failure. Pretreatment with antihistamines and corticosteroids is often sufficient to avoid an allergic reaction. A femoral artery closure device can be used to avoid bleeding complications in a patient with coagulopathy. In patients with impaired renal function, intravenous prehydration and limited use of contrast will reduce the risk of increased renal dysfunction.
As more research has been carried out into uterine artery embolization, it has been found to be more widely applicable than previously thought and only a few relative and absolute contraindications remain. To conclude, uterine artery embolization for symptomatic fibroids is a safe and effective minimally invasive uterine-sparing therapy that can be considered a first-line therapy for women who do not wish to bear children. In my opinion, women interested in future pregnancy may be offered embolization, but only after careful counselling and after the consideration of other possibilities in keeping with the patient’s reasonable expectations, needs and preferences. The definitive decision on treatment is best made by the patient after consultation with a closely cooperating fibroid team with an interventional radiologist and gynaecologist, who is also surgically competent.
Paul NM Lohle is an interventional radiologist, St Elisabeth hospital, Tilburg, The Netherlands. He has reported no disclosures pertaining to this article