Changes in Blood Coagulation Markers Associated with Uterine Artery Embolization for Leiomyomata

Uterine Artery Embolization for Leiomyomas and Adenomyosis: A Pictorial Essay Based on Our Experience from 1300 Cases

Since its introduction in 1995, uterine artery embolization (UAE) has become an established option for the treatment of leiomyomas. Identification of a leiomyoma using arteriography improves the ability to perform effective UAE. UAE is not contraindicated in a pedunculated subserosal leiomyoma. UAE in a cervical leiomyoma remains a challenging procedure. A leiomyoma with high signal intensity on T2-weighted imaging responds well to UAE, but a malignancy with similar radiological features should not be misdiagnosed as a leiomyoma. Administration of gonadotropin-releasing hormone agonists before UAE is useful in selected patients and is not a contraindication for the procedure. The risk of subsequent re-intervention 5 years after UAE is approximately 10%, which represents an acceptable profile. UAE for adenomyosis is challenging; initial embolization using small particles can achieve better success than that by using larger particles. An intravenous injection of dexamethasone prior to UAE, followed by a patient-controlled analgesia pump and intra-arterial administration of lidocaine after the procedure, are useful techniques to control pain. Dexmedetomidine is an excellent supplemental sedative, showing a fentanyl-sparing effect without causing respiratory depression. UAE for symptomatic leiomyoma is safe and can be an alternative to surgery in most patients with a low risk of re-intervention.

An unexpected complication following uterine artery embolisation

A 35-year-old nulliparous woman underwent uterine artery embolisation (UAE) for heavy menstrual bleeding and anaemia due to fibroids, refractive to medical and surgical treatment.Bilateral UAE was performed after cephazolin prophylaxis and analgesia. Postoperatively, pain and abdominal bloating were prominent. Symptoms were initially treated as postembolisation syndrome, and analgesia was escalated. By the third day, pain was worsening and the woman developed marked tachypnoea and tachycardia, with raised inflammatory markers and lactate. An abdominal X-ray and CT showed dilated colon. A colonoscopy demonstrated severe mucosal ulceration down to the muscular layer.A subtotal colectomy and end ileostomy formation was performed with intraoperative findings of toxic megacolon with near perforation. The cause of the toxic megacolon, in the absence of previous bowel pathology, was attributed to pseudomembranous colitis as a consequence of single dose prophylactic antibiotic.

Current concepts in uterine fibroid embolization

Uterine fibroid embolization (UFE) has become established as an accepted minimally invasive treatment for uterine fibroids and should be considered a treatment option for patients with symptomatic uterine fibroids. It is important for diagnostic radiologists to understand the procedure, since imaging is a key component in the evaluation and care of these patients. Both the interventional radiologist and the gynecologist must fully evaluate a patient before recommending UFE as a treatment for symptomatic fibroids. However, relatively few absolute contraindications exist (pregnancy, known or suspected gynecologic malignancy, and current uterine or adnexal infection). A thorough evaluation includes a medical history, menstrual history, physical examination, and discussion of fertility goals. In almost all cases, bilateral uterine artery catheterization and embolization are needed, since most uterine fibroids, whether single or multiple, receive blood supply from both uterine arteries. After UFE, patients can reasonably expect resolution of symptoms such as menorrhagia, pelvic pressure, and pelvic pain. Although infrequent, major adverse events can occur and include ovarian failure or amenorrhea, fibroid expulsion, and rarely venous thromboembolism. Hysterectomy remains the definitive and most common treatment for uterine fibroids, but less-invasive approaches such as UFE are becoming of greater interest to both patients and physicians.

Complications associated with uterine artery embolisation for fibroids

Uterine artery embolisation (UAE) is a relative newcomer to the mainstream treatment modalities available for fibroid-related problems. The efficacy of UAE is indisputable and has been shown to be comparable to hysterectomy in the short term in large-scale trials. Moreover, compared with hysterectomy, UAE is less invasive, carries a superior risk profile, and, importantly, preserves the uterus. UAE therefore offers patients symptom relief whilst at the same time retaining reproductive potential. Notably however, although women can have successful pregnancies following UAE, it is becoming increasingly evident that pregnancies after UAE are more risky especially during the early stages. Long-term outcome data from randomised trials involving UAE have very recently become available and show that whilst high satisfaction rates previously identified during early-stage followup are sustained, one notable drawback is a substantial risk of reintervention. It remains to be seen how this facet of UAE will impact on its future uptake.

The relationship between urokinase plasminogen activator/plasminogen activator inhibitor type-1 expression in myoma/myometrium and mechanism of uterine artery occlusion by laparoscopy for uterine myoma treatment

The objective of the study was to investigate the pattern of expression of plasminogen activator/plasminogen activator inhibitor (PAI) system between myoma and myometrium and its correlation between outcome and laparoscopic uterine artery occlusion prior to myomectomy in the treatment of myoma. mRNA expression of PAI type-1 (PAI-1) and urokinase plasminogen activator (uPA) was detected with real-time PCR in the myoma and myometrium cells primary cultured in vitro, and uPA and PAI-I protein expression was detected with cellular immunity histochemistry. First, the expression of uPA mRNA was 0.123 +/- 0.189 in myoma, which was significantly lower than 0.331 +/- 0.306 in myometrium (P < 0.05); however, the expression of PAI-I mRNA was 0.091 +/- 0.036 in myoma, which was significantly higher than 0.016 +/- 0.020 in myometrium (P < 0.05). Second, the expression of uPA protein was 8.805 +/- 1.645 in myoma cells, which was lower than 22.173 +/- 4.381 in myometrium (P < 0.05); the expression of PAI-I protein was 44.765 +/- 1.090 in myoma cells, which was significantly higher than 35.928 +/- 5.351 in myometrium (P < 0.05). The distinct expression pattern of uPA/PAI in myoma and myometrium might be correlated to the low recurrence rate after uterine artery occlusion prior to myomectomy in the treatment of myoma.

THROMBOPHILIC ABNORMALITIES AMONG PATIENTS WITH CRANIAL DURAL ARTERIOVENOUS FISTULAS

OBJECTIVE

Dural sinus thrombosis often accompanies or precedes the development of dural arteriovenous fistulas (DAVFs). Because thrombophilic abnormalities can contribute to sinus thrombosis, we investigated the prevalence of such abnormalities and of venous sinus thrombosis in patients with DAVFs.

METHODS

Thrombophilic factors were measured in 18 patients with DAVFs treated with embolization at our university hospital. Control data were obtained from patients with unruptured intracranial aneurysms. In addition to sinus occlusion, we investigated prothrombin time, activated thromboplastin time, platelet count, and fibrinogen, platelet, antithrombin III, protein C, protein S, anticardiolipin antibody, anti-cardiolipin β2-glycoprotein-I complex antibody, and D-dimer levels.

RESULTS

Of the 18 patients with DAVFs, 16 had abnormal D-dimer levels, whereas the mean values for other thrombophilic factors were nearly normal. D-dimer levels were significantly higher in preoperative DAVF patients than in controls. Interestingly, the mean value of D-dimer was higher in patients with sinus occlusion than in those without it (3.33 versus 1.19). D-dimer levels rose after embolization in eight out of 10 serially tested patients, but, on average, the change was not significant. In clinically cured patients treated more than 3 months before, D-dimer was lower than in preoperative patients.

CONCLUSION

D-dimer is a very sensitive indicator of acute venous thrombosis, suggesting that elevations in patients with DAVFs are likely to reflect sinus thrombosis. D-dimer values decreased and nearly normalized in clinically cured patients during a long-term follow-up period, a finding consistent with completion of thrombosis and cure of the disease. To clarify the correlation between DAVF and sinus thrombosis from the aspect of etiology, we should thoroughly check the variation in the concentration of the thrombophilic factors in the patient with chronic sinus occlusion to know the variation in the fistula formation in the further study.

Venous Thromboembolism After Uterine Fibroid Embolization

Thromboembolic complications after uterine fibroid embolization (UFE) are infrequent. The incidence and predisposing factors of thromboembolism after UFE are unknown. We present eight cases of nonfatal thromboembolic complications after UFE and estimate the frequency of such events as 0.4%.

Childbirth and Myoma Treatment by Uterine Artery Occlusion: Do They Share a Common Biology?

When the uterine arteries are bilaterally occluded, either by uterine artery embolization or by laparoscopic obstruction, women with myomas experience symptomatic relief. After the uterine arteries are occluded, most blood stops flowing in myometrial arteries and veins, and the uterus becomes ischemic. It is postulated that myomas are killed by the same process that kills trophoblasts: transient uterine ischemia. When the uterine arteries are bilaterally occluded, either by uterine artery embolization (UAE) or by laparoscopic obstruction, women with myomas experience symptomatic relief. After the uterine arteries are occluded, most blood stops flowing in myometrial arteries and veins, and the uterus becomes ischemic. Over time, stagnant blood in these arteries and veins clots. Then, tiny collateral arteries in the broad ligament (including communicating arteries from the ovarian arteries) open, causing clot within myometrium to lyse and the uterus to reperfuse. Myomas, however, do not survive this period of ischemia. This is unique organ response to clot formation and ischemia. What allows the uterus to survive a relatively long period of ischemia while myomas perish? Childbirth appears to be the predicate biology. Following placental separation, the uteroplacental arteries and the draining veins of the placenta are torn apart at their bases in the junctional zone of the myometrium and bleed directly into the uterine cavity. Left unchecked, every woman would bleed to death in less than 10 minutes after placental delivery. Most women do not bleed to death because vessels in the uterus clot after placental delivery. During pregnancy, clotting and lytic factors in blood increase many fold. Following delivery, uterine contractions continue, intermittently, periodically slowing the velocity of flowing blood through myometrium. The combination of slowed blood flow, elevated clotting proteins, and torn placental vessels (known as Virchow's triad) causes blood in myometrial arteries and veins to clot. Fibrinolytic enzymes later lyse clot in arteries and veins not associated with placenta perfusion, and the uterus is reperfused. Remnant placental tissue - primarily uteroplacental arteries and veins - does not survive this period of ischemia. Placental tissue dies and over weeks is sloughed into the uterine cavity. At the same time, residual endometrial tissue grows under the sloughing placental tissue thus re-establishing the endometrial lining. It is postulated that myomas are killed by the same process that kills trophoblasts - transient uterine ischemia.