Post‐embolization syndrome and complete expulsion of a leiomyoma after uterine artery embolization

Abstract

Uterine artery embolization is a minimally invasive therapeutic alternative to surgery for patients with symptomatic leiomyomas. It is important that physicians dealing with embolized patients be familiar with common and expected reactions such as post-embolization syndrome (PES) and transcervical expulsion of complete or fractions of fibroids. These reactions should not be confused with serious complications such as infection. This case report and the following discussion highlight these matters. The case of a 41-year-old (gravida 1, para 1) healthy, nonsmoking Swedish woman, with a more than 10-year history of fibroids is presented. During cesarean section in 1990 because of breech presentation, an intramural fibroid measuring 3–4 cm in size was found. The following years the woman suffered from increasing menorrhagia which was considered to be caused by growing fibroids. In 1995, she underwent a laparotomy for myomectomy. Three intramural fibroids were found. Two of them were successfully enucleated. The largest, 5 cm in diameter, was situated close to the myometrial–endometrial border and was therefore not possible to resect completely. Continuous heavy menstrual bleedings lasting up to 14 days/cycle caused anemia with a hemoglobin level down to 8.0 g/dl, in spite of per oral medication with tranexamic acid and ferritin. In May 2001, a transvaginal sonography showed an intramural fibroid 4.7 cm in diameter, not accessible laparoscopically or transcervically. The patient did not want to consider hysterectomy for fear of losing her sense of being a fertile and attractive woman. She desired to be treated by embolization of the uterine arteries, a method she had read about on the Internet. Preoperative evaluation with magnetic resonance tomography performed in December 2001 demonstrated a submucosal fibroid measuring 3.5 × 4.5 × 5.5 cm, located at the uterine fundus together with four smaller fibroids (Fig. 1). Coronar T2-weighted magnetic resonance scan showing a low-signal submucosal fibroid *3.5 × 4.5 × 5.5 cm in size, protruding centrally into the uterine cavity. A small intramural fibroid (large arrow) and a minor subserosal fibroid (small arrow) are also visualized. In January 2002, bilateral uterine artery embolization was performed, injecting 355–500 µm of polyvinyl alcohol particles to induce vascular standstill. There were no complications during the procedure. On the operative and first postoperative day, the patient experienced nausea, moderate lower abdominal pain, and a temperature increase to 39 °C. The second day after embolization, she recovered and was discharged to home. In the following days, she experienced only minor discomfort but no pain. She was back to work, including traveling, 1 week after the procedure. On a follow-up visit, which included transvaginal ultrasound, in September 2002, the patient reported that her menstruations had normalized to regular scanty menstruations of 3–4 days' duration, sometimes containing small pieces of solid material (fibroid fragments). Between the menstrual periods, she had no vaginal discharge. Ultrasound revealed two fibroids, measuring 1.6 and 1.2 cm. Magnetic resonance tomography 1 year after the embolization demonstrated a normal-sized uterus with two degenerated fibroids of 1 cm each (Fig. 2). The largest fibroid had completely disappeared. Coronar T2-weighted magnetic resonance scan 1 year after bilateral uterine artery embolization in the same patient as in Fig. 1. The large submucosal fibroid has completely disappeared. The small intramural fibroid (arrow) has marginally shrunken. In 2004, 2 years after embolization, the patient reported still normal menstruations and no vaginal discharge. Conventional treatment of fibroids has been surgical, i.e. hysterectomy or abdominal myomectomy. In recent years, alternative surgical methods have been used such as laparoscopic myomectomy, myolysis, and hysteroscopic resection. Some women refuse hysterectomy for psychological and reproductive reasons. The major problem associated with myomectomy is the risk of recurrence that will require further surgery. The surgical procedure may also be difficult or even impossible to perform in cases of multiple myomas. Uterine artery embolization is gaining in popularity as a minimally invasive therapeutic alternative to surgery for patients with symptomatic fibroids. The first report of arterial embolization to treat fibroids was published in Lancet in 1995, describing 16 patients (1). Since then, a number of other studies with excellent results have been published (2, 3). The mean reduction in volume of the dominant fibroid varies between 33 and 73%. Approximately 85% of the patients improve in symptoms regarding menorrhagia or bulk-related symptoms (2). Contraindications are ongoing pregnancy, renal failure, severe contrast allergy, genital infection/inflammation, or other pelvic mass. Exclusion of adenomyosis is important because most groups report poor response, and presence of adenomyosis may in some cases explain clinical failure after fibroid embolization. An upper or lower fibroid volume limit for a successful outcome after embolization has not been reported, but it is likely that the risk of complications is increased when a fibroid is very large. Pedunculated and small subserosal or submucosal fibroids should preferentially be removed by laparoscopy and hysteroscopy, respectively. Serious complications are rare. Temporary or permanent amenorrhea has been reported in up to 5% of embolized patients (<2% of women under 45 years) (4, 5). Most women admitted for embolization are close to menopause, which may explain some of the cases. Several cases of pregnancy and childbirth have been described after uterine artery embolization, and a desire to become pregnant is not any longer considered a contraindication. Approximately 0.5% of embolized patients are afflicted with severe infection, mainly endometritis, that may make hysterectomy necessary in some cases. Infection may occur within the initial 6 months after embolization (6). The most frequent pathogen isolated is Escherischia coli (4). In terms of differential diagnostics, the so-called fibroid birth must be considered, i.e. a freed fibroid is pressed down to the cervical channel. Fibroid birth usually causes pain and sometimes a rise in temperature. If impaction and infection occur, the fibroid must be removed by hysteroscopic resection or other surgical intervention. It is more common that small pieces of fibroid material pass out with fluid, as in our case. There are several reports of complete expulsion of fibroids after uterine artery embolization (4, 5, 7-10). In Walker and Pelage's (5) report of clinical results in 400 women, fibroids were spontaneously discharged transvaginally after embolization in nine patients (2.25%) and five additional women (1.25%) required hysteroscopic resection for infection and pain due to infarcted fibroids. Expulsion and resection occurred between 2 weeks and 2 years after embolization. Vaginal discharge is common (58%) after fibroid embolization and may be regarded as an expected and even desired consequence of the intervention as infarcted fibroid material pass out. However, in 23% of patients with discharge, it becomes persistent though cyclically discontinuous, and some women (4%) regard their discharge a major irritant (5). Hysteroscopic resection of infarcted fibroids communicating with the uterine cavity may solve this problem. Most women experience pelvic pain, starting 10–20 min after completed uterine artery embolization. The pain is most severe during the first 8 h and usually demands 1 or 2 days of hospitalization for adequate analgesic treatment, in most cases with a patient-controlled analgesic pump combined with a nonsteroidal anti-inflammatory drug (NSAID). In the majority of patients, opiates are required for the first 12–18 hr after the procedure. Thereafter, the pain declines but can be slight to moderate the following 2–3 weeks 2-5). No correlation has been established between severity of pain and uterine size, myoma number or size, duration of procedure, quantity of embolization particles used, or clinical outcome (4). The pain may be combined with nausea, generalized malaise, low-grade fever, mild leukocytosis, and a moderate rise of C-reactive protein. This condition can be recognized as PES and is known to occur after embolization of organs such as liver, spleen, and kidney in approximately 90% of cases. In patients treated with uterine artery embolization, it has been reported to occur in one third of the cases. PES usually occurs within 24–48 hr of the procedure. The syndrome is self-limiting and usually resolves within 2 days but may last up to 7 days after the procedure 2-4, 11-14). PES is believed to be caused by inflammatory response to necrotic tissue after embolization, with the release of endogenous cytokines, and the use of steroids and NSAID may reduce the rate of PES (4, 14). The syndrome is more severe when a large volume of tissue has been embolized. Therefore, in the liver, repeated treatment in different segments (usually the left versus the right liver lobe) is performed, in order to minimize symptoms of PES and the risk of hepatic insufficiency. However, uterine fibroid embolization requires bilateral embolization to become successful, owing to the abundant anastomoses between the left and right uterine artery within the uterus (3, 15). PES should not be confused with abscess development or other complications of infection after uterine artery embolization, as mentioned above. PES causes discomfort to the patient without any other clinical signs of complications, as in our case. Symptoms of infection usually manifest later than PES, i.e. 1 week and up to 6 months after embolization, and are often combined with purulent vaginal discharge and increasing pain. After clinical examination including full blood count and blood cultures, antibiotics should be given. In order to find infected retained material, magnetic resonance imaging is of great value. The presence of gas within necrotic tissue is a normal finding after embolization and does not necessarily indicate abscess. There is still no consensus on whether patients benefit from prophylactic antibiotic treatment. PES in embolized patients needs to be further analyzed in future studies in order to optimize symptom relief and differentiation from infection. So far, recurrence after an initially successful uterine artery embolization has not been reported, but long-term results are yet to be determined. More studies are required before the method can be recommended to treat infertility assumed to be caused by fibroids. Prospective randomized studies comparing myomectomy and uterine artery embolization are yet to be published. Moreover, there is a need to determine the most appropriate embolization substances and techniques.