Uterine Vascular Malformations Research Articles

Role of Hysteroscopy in the Management of Uterine Vascular Malformations with a Focus on Enhanced Myometrial Vascularity – A Review of Diagnosis and Treatment with the Suggested Algorithm

Abstract Postpregnancy bleeding is common after failed pregnancy, termination of pregnancy, and postnatally after both vaginal and cesarean delivery. Pelvic ultrasound (US) is usually the initial imaging modality of choice to ascertain the cause when the bleeding is heavy or prolonged. When used in combination with Doppler studies, US can help differentiate retained products of conception (RPOC) from rarer uterine vascular malformations (UVM), including true arterial vascular malformations and areas of enhanced endometrial vascularity (EMV), which may themselves be associated with any RPOC present. While the management of RPOC is well established and has evolved from an almost universal surgical approach to increasingly more medical or expectant alternatives, clinical decisions over the management of a concurrent UVM are less clear and treatment options need to be individualized depending on features of the lesion and the clinical situation with hysteroscopy featured as an important modality, especially when dealing with EMV’s. In this review, we discuss the role of hysteroscopy in the treatment of enhanced myometrial vascularity with and without associated RPOC and propose a management algorithm.

Efficacy of Embolization in Acquired Uterine Vascular Malformations: An Experience in Tertiary Care Centre in India.

To determine the efficacy of Uterine Artery Embolization in patients with bleeding acquired uterine arteriovenous malformations (AVMs). A prospective review of all patients who underwent Uterine Artery Embolization at our institution between July 2015 and April 2022 was performed. 225 patients were diagnosed with a uterine vascular malformation on doppler and corresponding MRI imaging. All patients underwent transcatheter embolization of the uterine arteries. Embolic agents in the 375 procedures included Histoacryl glue only (n = 326), polyvinyl alcohol (PVA) particles and Histoacryl glue (n = 29), PVA particles (n = 5), Gelfoam (n = 5), coils (n = 4), PVA particles and coils (n = 3), Histoacryl glue and Gelfoam (n = 2), and Histoacryl glue and coils (n = 1). A total of 375 embolization procedures were performed in 225 patients. 90 patients required repeat embolization for recurrence of bleeding. The technical success rate of embolization was 100%. The clinical success rate was 92%: bleeding was controlled in 222 of 225 patients and three patients underwent a hysterectomy. 60 of the 225 patients had uneventful intrauterine pregnancies carried to term. The 210 patients who underwent successful embolization had no recurrence of bleeding at a median follow-up of 53 months (range, 5-122 months) after treatment. 15 patients were eventually lost to follow-up. One minor complication (0.4%) of non-flow-limiting dissection of the internal iliac artery occurred. Uterine Artery Embolization is a safe, effective, minimally invasive method to treat uterine AVMs with long-term efficacy, which can provide the preservation of fertility.

Can Three-Dimensional Rotational Angiography Road Map be used for Individualized Guidance of Uterine Artery Catheterization as in Intracranial Arteries Intervention?

It is widely accepted that Uterine Artery (UA) Embolization (UAE) is an effective, minimally invasive therapeutic strategy for symptomatic uterine fibroids and PPH of various causes along with conventional surgical treatment of hysterectomy and myomectomy. Also it is an effective interventional procedure for the treatment of uterine vascular malformations, pregnancy incisions, denomyosis and cervical cancer with bleeding.

Evaluation of Blood Perfusion in the Myometrium of Women with Symmetric Uterine Anomalies Using Dynamic Contrast-Enhanced MRI.

Study Objective The objective of our study is to evaluate functional/dynamic enhanced MRI evaluation of the vascular (capillary) circulation of the myometrium and intrauterine septum in patients with symmetric uterine anomalies. Design Prospective cohort study, Level II. Setting National Medical Research Center for Obstetrics, Gynecology and Perinatology, Moscow, Russia. Patients or Participants 247 patients of patients with symmetric uterine anomalies were evaluated and treated between 2015 and 2020 at the department of operative gynecology. Interventions Surgical correction of genital malformations was performed in accordance with clinical manifestations: miscarriage or infertility. The new method of functional/dynamic contrast enhanced (DCE) MRI was employed in order to estimate uterine blood perfusion in symmetric uterine malformations. Dynamic monitoring of serial images evaluated the blood supply in the myometrium and septum by digital diagram and color-mapping. Measurements and Main Results The functional MRI was performed in 72 patients requiring surgery, and 30 patients managed without surgical correction. Microcirculation was reduced by over 32 % in most (87%) patients with sub-septate uterus, and in 46% of patients with complete uterine septum, increasing the need for hysteroresectoscopic metroplasty in these patients. Histopathologic evaluation of the resected septi identified the presence of significant uterine dysmorphogenesis, vascular malformations, and deep myometrial fibrosis. The asymmetric perfusion of the duplicate uterus was detected in 85% of patients, because the myometrial blood perfusion was reduced much more 22% in hemi-uteri. Successful pregnancy progressed in hemi-uteri with better perfusion results (p Conclusion Functional/dynamic-enhanced MRI identifies the degree of blood perfusion in the myometrium and intrauterine septi of women with symmetric uterine anomalies and may assist in development of surgical and assisted reproductive strategies in the management of these patients.

Functional (Dynamic Contrast-Enhanced) MRI Assists in the Evaluation of Blood Perfusion in Myometrium and Intrauterine Septi of Women with Symmetric Uterine Anomalies

Study Objective Successful reproductive outcomes of patients with uterovaginal anomalies remain in the range of 25-37%, despite applying minimally invasive surgical corrections and assisted reproductive methods. The objective of our study is to introduce functional/dynamic enhanced MRI evaluation of the vascular circulation of the myometrium and intrauterine septum in patients with symmetric uterine anomalies. Design Prospective cohort study. Setting National Medical Research Center for Obstetrics, Gynecology and Perinatology, Moscow, Russia. Patients or Participants 213 patients of patients with symmetric uterine anomalies were evaluated between 2015 and 2017 at our department. Interventions Surgical correction of genital malformations was performed in accordance with clinical manifestations: obstruction of menstrual outflow, abdominal pain, infertility, miscarriage, sexual problems. The new method of functional/dynamic contrast enhanced (DCE) MRI was employed in order to estimate uterine blood perfusion in symmetric uterine malformations. Dynamic monitoring of serial images evaluated the blood supply in the myometrium and septum by digital diagram and color-mapping. Measurements and Main Results The functional MRI was performed in 42 patients requiring surgery, and 30 patients managed without surgical correction. Microcirculation was reduced by over 32 % in most patients with sub-septate uterus, and in 46% of patients with complete uterine septum, increasing the need for hysteroresectoscopic metroplasty in these patients. Histopathologic evaluation of the resected septi identified the presence of significant uterine dysmorphogenesis, vascular malformations, and deep myometrial fibrosis. The asymmetric perfusion of the duplicate uterus was detected in 85% of patients. Successful pregnancy progressed in hemi-uteri with better perfusion results (p Conclusion Functional/dynamic-enhanced MRI identifies the degree of blood perfusion in the myometrium and intrauterine septi of women with symmetric uterine anomalies and may assist in development of surgical and assisted reproductive strategies in the management of these patients.

Acquired Uterine Vascular Malformation: Clinical Outcome of Transarterial Embolization

Acquired Uterine Vascular Malformation: Clinical Outcome of Transarterial Embolization

Transcatheter Arterial Embolization with n-Butyl Cyanoacrylate for the Treatment of Acquired Uterine Vascular Malformations

The purpose of the study was to evaluate the technique and outcomes of transcatheter arterial embolization (TAE) with n-butyl cyanoacrylate (NBCA) for the treatment of acquired uterine arteriovenous malformations (AVMs). A retrospective review identified five women treated for suspected acquired uterine AVMs with TAE at our institution. Four women (80%) presented with heavy or intermittent vaginal bleeding after obstetric manipulation. One woman (20%) was treated for an incidental AVM discovered on ultrasound after an uncomplicated cesarean section. Three women underwent one embolization procedure and two women required two procedures. Embolization material included NBCA in six procedures (80%) and gelatin sponge in one procedure (20%). Embolization resulted in angiographic stasis of flow in all seven procedures. Four women (80%) presented with vaginal bleeding which was improved after treatment. One woman returned 24days after unilateral embolization with recurrent bleeding, which resolved after retreatment. One woman underwent two treatments for an asymptomatic lesion identified on ultrasound. There were no major complications. Three women (60%) experienced mild postembolization pelvic pain that was controlled with non-steroidal anti-inflammatory drugs. Three women (60%) had pregnancies and deliveries after embolization. TAE is a safe alternative to surgical therapy for acquired uterine AVMs with the potential to maintain fertility. Experience from this case series suggests that NBCA provides predictable and effective occlusion.

Uterine arteriovenous vascular malformation masked by partial molar pregnancy: diagnostic challenge and subsequent embolic treatment.

Uterine arteriovenous vascular malformations (UAVM) are uncommon and usually present in women of reproductive age. When these occur in a pregnant patient or in the immediate postpartum period, clinical presentation may overlap with several other entities such as retained products of conception (RPOC), postpartum endometritis, as well as gestational trophoblastic disease (GTD) [1]. We present a case of a UAVM that presented with life-threatening vaginal bleeding several months after dilatation and curettage (D&C) of a molar pregnancy. The UAVM was diagnosed with ultrasound (US) and magnetic resonance imaging (MRI), and subsequently treated with transarterial embolization (TAE).

2:18 PM Abstract No. 156 - Techniques and outcomes of uterine artery embolization in the management of post-partum or post-abortion hemorrhage secondary to uterine vascular malformations

Purpose To evaluate techniques and outcomes of uterine artery embolization (UAE) in the management of post-partum or post-abortion hemorrhage secondary to uterine vascular malformations (UVM). Materials and Methods The study population consisted of all patients who had UAE for post-partum or post-abortion hemorrhage at any one of our three hospitals over a 102 month period (Jan 2003 to July 2011). UVMs were diagnosed using standardized criteria with gray-scale and doppler ultrasound. Embolic agents used included: metallic coils, microcoils, polyvinyl alchohol (PVA) particles and microspheres, absorbable gelatin sponge, and Gelfoam. Patient demographics, prenatal history, techniques and agents, efficacy, hospital stay, complications, patient satisfaction, menses and subsequent pregnancies were recorded. Results During the study period, there were 25 patients who had 32 UAE procedures. Mean age was 26.6 years. Bilateral UAE was performed in 11 patients, and unilateral in 14. Embolic agents used were: microcoils (n = 8, 32%), microcoils and gelfoam pledgets (n = 3, 12%), microspheres (n = 3, 12%), glue (n = 1, 4%), polyvinyl alcohol particles (PVA) (n =12, 48%), PVA and gelfoam pledgets (n = 5, 20%). 17 (68%) had no bleeding recurrence. 8 (32%) experienced rebleeding post-embolization, which was either treated supportively or required further intervention with repeat embolization, DandC, or hysterectomy. On follow-up (mean 29 months, range 3-58 months): 7 patients were lost to follow up or refused to comment. Subjective level of satisfaction on a scale of 1-10 was 8.5 (range 7-10). 8 patients became pregnant 9 times. 2 had elective abortions. 6 had 7 uneventful intrauterine pregnancies with normal infants. Conclusion UAE is safe and effective in patients with post-partum or post-abortion hemorrhage secondary to a UVM, with preservation of fertility, and should be considered the first line of treatment. UAE is effective with a myriad of embolic agents, including microcoils, not just PVA and glue as described in previous literature.

Prospective Evaluation of the Incidence of Uterine Vascular Malformations Developing After Abortion or Delivery

Study ObjectiveTo describe the incidence of uterine vascular malformations (UVMs) including uterine arteriovenous malformations (AVMs) in patients after abortion or delivery and in outpatients. DesignProspective study (Canadian Task Force classification II-3). SettingFukushima Red Cross Hospital. PatientsSix patients with a UVM including 1 with an AVM. InterventionsClinical screening of patients using transvaginal color Doppler ultrasonography between April 2010 and March 2012. Measurements and Main ResultsThe incidence of UVM developing after abortion or delivery or in outpatients was prospectively evaluated using transvaginal color Doppler ultrasonography. From 959 patients, we identified 6 (0.63%) with UVMs, including 1 (0.10%) with a uterine AVM. Specifically, we detected UVMs in 4 of 77 patients (5.2%) after abortion, 1 of 458 patients (0.22%) after delivery, and 1 of 424 outpatients (0.24%). Four patients after abortion and 1 after delivery reported mild symptoms, which were treated conservatively; however, the outpatient had a severe uterine AVM, which was confirmed via 3-dimensional computed tomography angiography. ConclusionThe incidence of UVMs was relatively higher, in particular in the patients after abortion, and was significantly higher than that in postpartum or outpatient groups. Therefore, it is important to consider the possibility of UVMs in any patient with episodes of unexplained uterine bleeding and to perform follow-up analysis using color Doppler ultrasonography. Such an approach will facilitate accurate diagnosis and lead to appropriate clinical management to prevent unnecessary dangerous repeat curettage, which might induce profuse uterine bleeding.

Uterine artery embolization in residual arterio-venous fistula due to invasive mole using glue and polyvinyl alcohol particles: Case report

Gestational trophoblastic diseases (GTD) are one of the rare complications of pregnancy, which include partial and complete moles with their more aggressive counterparts termed as Gestational trophoblastic neoplasias (GTN). Their association with uterine vascular malformations is well recognised and should be suspected in appropriate clinical settings. Selective uterine artery embolization is a safe and effective alternative method of treatment in a patient with severe per vaginal bleeding from residual uterine vascular malformations due to GTN which has relative lower morbidity and mortality than surgical procedures. Here, we report a case of residual uterine arterio-venous malformation due to invasive mole detected by ultrasonography (US) and contrast enhancedMRI & referred to Interventional Radiology for Transcathetor arterial embolization.

Efficacy and safety of embolization in iatrogenic traumatic uterine vascular malformations

To retrospectively evaluate the efficacy of embolotherapy in patients with iatrogenic traumatic uterine arteriovenous malformations (AVMs). A retrospective review of all patients who underwent uterine arterial embolization in Peking Union Medical College Hospital between January 2000 and December 2010 was performed. Forty-two patients were diagnosed with a uterine vascular malformation. All patients had obstetric manipulations before. Serial beta-human chorionic gonadotropin (β-HCG) levels were measured to exclude gestational trophoblastic neoplasia. All patients underwent transcatheter embolization of bilateral uterine arteries. The complications, control of haemorrhage, and outcome of subsequent pregnancies were assessed. A total of 49 embolization procedures were performed in 42 patients. Seven patients required repeated embolizations for recurrence of bleeding. The technical success rate of embolization was 100%. Bleeding was controlled in 35 of 42 patients (83%) after the first embolization procedures, and bleeding was controlled in another two patients who underwent repeat embolization at a median follow-up of 29 months (range 3 months to 5 years). The overall clinical success rate was 88% (37/42). Thirteen patients subsequently became pregnant and eight of 13 patients had uneventful intrauterine pregnancies carried to term. Seven patients had post-embolization syndrome and no other complication occurred. Percutaneous embolotherapy is a safe and effective treatment for traumatic AVMs. Future pregnancy is still possible after embolization.

Vascular malformation in the uterus: a case report and literature review

Uterine vascular malformations are rare, potentially life-threatening lesions that originate from dysfunctional venous and arterial communications. They present with heavy vaginal bleeding which does not respond to conventional treatment. They can be congenital or acquired. Acquired arterio-venous malformations (AVMs) may be preceded by uterine curettage, caesarean section, gestational trophoblastic neoplasia or endometrial carcinoma. Ultrasound with colour Doppler is the most common initial investigation, with magnetic resonance imaging being used for detailed evaluation. However, angiography remains the gold standard. Embolization is becoming increasingly the first choice of treatment with excellent results. We present a case of uterine AVM successfully treated with embolization, along with a review of the literature.

Abdomen agudo por rotura espontánea de un leiomioma uterino subseroso

Although pelvic pain and metrorrhagia are the disorders that are most commonly associated with uterine leiomyoma, acute hemoperitoneum due to rupture of a subserosal leiomyoma is an exceptional event that has scarcely been reported in the international medical literature. This article describes one of the few known cases of acute abdomen caused by spontaneous rupture of a subserosal uterine leiomyoma, which was treated at the Department of Gynecology of the Hospital Universitario Central de Asturias (Spain). Risk factors for this unusual entity are considered to be the patient’s age and parity, as well as the size of the myoma and certain uterine vascular malformations; however, in this specific case, some histological peculiarities of the tumor seem to be of relevance.

Acquired uterine vascular malformations: radiological and clinical outcome after transcatheter embolotherapy

The purpose of this retrospective study is to assess the radiological and clinical outcome of transcatheter embolization of acquired uterine vascular malformations in patients presenting with secondary postpartum or postabortion vaginal hemorrhage. In a cohort of 17 patients (mean age: 29.7 years; standard deviation: 4.23; range: 25-38 years) 18 embolization procedures were performed. Angiography demonstrated a uterine parenchymal hyperemia with normal drainage into the large pelvic veins ("low-flow uterine vascular malformation") in 83% (n=15) or a direct arteriovenous fistula ("high-flow uterine vascular malformation") in 17% (n=3). Clinically, in all patients the bleeding stopped after embolization but in 1 patient early recurrence of hemorrhage occurred and was treated by hysterectomy. Pathological analysis revealed a choriocarcinoma. During follow-up (mean time period: 18.8 months; range: 1-36 months) 6 patients became pregnant and delivered a healthy child. Transcatheter embolization of the uterine arteries, using microparticles, is safe and highly effective in the treatment of a bleeding acquired uterine vascular malformation. In case of clinical failure, an underlying neoplastic disease should be considered. Future pregnancy is still possible after embolization.

Three‐dimensional power Doppler sonographic features of uterine vascular malformation

Three‐dimensional power Doppler sonographic features of uterine vascular malformation

Heavy uterine bleeding due to uterine arteriovenous malformations

Heavy uterine bleeding without cervical trauma, uterine perforation, atony and refractory to conventional therapies is highly suspicious arising from uterine arteriovenous malformations. Injuries of uterine artery malformations are rare but life-threatening conditions (1–4), which are confirmed with an angiography and treated by a definitive hysterectomy. The patient was a 39-year-old woman, gravida 8, para 1: status postelective dilatation and curettage (D&C) due to a missed abortion at a clinic. On the fifth postoperative day, the patient presented with complaints of intermittently profuse vaginal bleeding with blood clots. Repeat suction curettage was carried out and a foley catheter tamponade was inserted with no obvious affect. She was then transferred to our hospital on the tenth day. Pelvic sonogram showed hematometra over the lower segment of the uterus. Uterine perforation was thought unlikely. The uterus felt firm, and uterotonic agents (prostaglandin E1 and oxytocin) had already been administered. Suction curettage was performed carefully, but heavy bleeding continued from the uterus and the amount of blood loss was approximately 1400 ml within seconds. A balloon tamponade was immediately inserted into the uterus. The patient experienced profuse vaginal bleeding that did not subside. She was hemodynamically unstable, and her hemoglobin dropped to 5.4 gm/dl (hematocrit: 17%) from 11.4 g/dl (hematocrit: 34.3%) after 4 h of the procedure. No gestational production was found during the histologic findings. Coagulation studies were within normal limits. Prompt hemodynamic resuscitation was with intravenous fluids and 4 units of packed red blood cells. It was then decided to intervene with a transarterial embolization. A pelvic arteriogram showed the arteriovenous malformations characterized by dilatation of branches of the uterine artery associated with fast venous filling, hypervascularity and extravasation from bilateral uterine artery malformations (Fig. 1a, b). Bilateral access to the uterine arteries was subsequently obtained, and the arteries were embolized with the use of a coil, with cessation of the bleeding (Fig. 2a, b). After the procedure, the patient's hemodynamics were stable (hemoglobin: 9.1 g/dl, hematocrit: 26.6%). After 2 days, the balloon tamponade was removed without active vaginal bleeding. The patient experienced defervescence and, after remaining afebrile for 48 h on a regimen of antibiotics, was discharged being hemodynamically stable with no active vaginal bleeding on day 3. Pelvic angiograms clearly show that pelvic hypervascularity and contrast extravasations showed the irregular, tortuous vascular nidus (arrow head) with early draining vein (arrow) on arterial phase, consistent with arteriovenous malformations, right (a) and left (b). Pelvic angiograms obtained after the embolic procedure showing complete embolization of the uterine arteries, right (a) and left (b). Unfortunately, she returned to our hospital on postembolized day 36 because of intractable lower abdominal pain and massive vaginal bleeding. A laparoscopically assisted vaginal hysterectomy was performed. The histology showed dilated and tortuous vessels. Finally the patient was discharge from the hospital on the 3th postoperative day in good condition. Uterine artery malformations are defined as having a dysplastic vascular origin with large feeding arteries causing decreased vascular resistance. They are rare but life-threatening conditions. The most common uterine vascular malformations are arteriovenous (1–4). This article described that no retained products of conception were found on repeat aspiration. The uterus felt firm, so uterine perforation was thought unlikely. A balloon tamponade failed to control the hemorrhage. The heavy hemorrhage refractory to treatment was proved to result from the laceration of bilateral uterine arteriovenous malformations by the pelvic angiography. Although finally a hysterectomy was necessitated, prompt diagnosis with pelvic angiography and treatment with embolization could be undertaken before resorting to emergency surgery. Our experience in this instance suggests that a history of abrupt, heavy, intractable uterine hemorrhage without another bleeding source (retained gestational products, traumatic cervix and uterus, atony, etc.) should indicate a uterine vascular malformations injury. A balloon tamponade and angiographic embolization may be useful for either complete ambulatory management or temporizing while awaiting the opportunity to perform definitive surgery such as a hysterectomy. It is possible that not only do uterine arteries feed the uterus but the arteries from the hypogastric artery and other extensive collateral arteries also contribute to uterine flow. The failure of embolization might be due to abundant collateral circulation and revascularization. Attempts to embolization of hypogastric arteries or ovarian vessels might be an effective means of controlling pelvic hemorrhage (5). However, the pati- ent refused to receive any further procedures. Surgical management is possibly an inevitable choice in the cessation of heavy uterine bleeding due to uterine arteriovenous malformations.

Color Doppler sonography of uterine disorders.

Color Doppler sonography (CDS) of uterine disorders has clinical applications for the evaluation of uterine fibroids, polyps, and vascular malformations. This review describes and illustrates these applications as well as the use of 3D CDS.

Efficacy of Embolization in Traumatic Uterine Vascular Malformations

To evaluate the efficacy of embolotherapy in patients with bleeding traumatic uterine arteriovenous malformations (AVMs). A retrospective review of all patients who underwent pelvic arterial embolization at our institution between July 1992 and September 2002 was performed. Fifteen patients were diagnosed with a uterine vascular malformation on duplex ultrasonography and correlative MR imaging. Serial beta-human chorionic gonadotropin levels were measured to exclude gestational trophoblastic neoplasia. All patients underwent transcatheter embolization of the uterine arteries. Embolizations were performed with use of standard 4-5-F catheters and microcatheters when necessary. Embolic agents in the 25 procedures included glue only (n = 13), polyvinyl alcohol (PVA) particles and glue (n = 4), PVA particles (n = 2), Gelfoam (n = 2), coils (n = 1), PVA particles and coils (n = 1), glue and Gelfoam (n = 1), and glue and coils (n = 1). PVA particle size ranged from 350 to 1,000 micro m. Outcomes assessed were cessation of bleeding, persistence or resolution of the AVM, complications, and pregnancy after embolization. These were assessed by chart, laboratory, and imaging reviews. A total of 25 embolization procedures were performed in 15 patients. Six patients required repeat embolization (one patient underwent embolization on six occasions; five patients had two embolization procedures each) for recurrence of bleeding. Sixteen procedures were performed on an elective basis and nine were performed on an emergent basis. The technical success rate of embolization was 100%. The clinical success rate was 93%: bleeding was controlled in 14 of 15 patients and one patient underwent a hysterectomy. Four of the 15 patients subsequently had a total of five uneventful intrauterine pregnancies carried to term. The 14 patients who underwent successful embolization had no recurrence of bleeding at a median follow-up of 53 months (range, 3-124 months) after treatment. Three patients were eventually lost to follow-up. One minor complication (0.4%) of non-flow-limiting dissection of the internal iliac artery occurred. Percutaneous embolotherapy is a safe and effective treatment for traumatic AVMs. This procedure allows for preservation of uterine function with the possibility of future pregnancy and should be considered as a primary treatment option.

Color Doppler imaging is a valuable tool for the diagnosis and management of uterine vascular malformations.

The aim of this study was to assess the spontaneous outcome of uterine vascular malformations detected with ultrasonography and color Doppler, and to investigate the predictive value of color Doppler imaging as to which patients require invasive treatment. This was a prospective observational study conducted between January 1999 and February 2001 comprising all consecutive patients diagnosed with a uterine vascular malformation by ultrasonography and color Doppler imaging. Spectral analysis included measurement of flow velocities, pulsatility index (PI) and resistance index (RI). Close follow-up was arranged in all cases and the outcomes were recorded. A total of 30 consecutive patients with uterine vascular malformations were included in the study. Spectral analysis of the vessels in the vascular malformations within the myometrium and endometrium revealed the presence of a low-impedance and high-velocity flow. The average values for PI, RI, peak systolic velocity (PSV) and time-averaged maximum velocity (TAMXV) were 0.50, 0.38, 0.63 m/s and 0.46 m/s, respectively. Eight patients (27%) eventually required embolization of the uterine arteries and three of them had true arteriovenous malformations confirmed at angiography. PSV values of >/= 0.83 m/s were associated with higher probabilities of further treatment, such as an embolization, whereas no vascular malformation with a PSV value < 0.39 m/s required embolization. Conservative management is possible in more than two-thirds of patients presenting with uterine vascular malformations diagnosed by color Doppler sonography. Despite considerable overlap, PSV values appear to be useful in distinguishing between low- and high-risk patients.