Congenital renal arteriovenous malformation with cirsoid and cavernosal-type characteristics: a case report

Renal arteriovenous malformations (AVMs) are infrequent vascular morphological anomalies. About 20% of AVMs are congenital renal AVMs (CRAVMs). A 53-year-old female patient presented with a 5-day history of gross hematuria and right flank pain. The patient underwent the selective renal arteriography and embolization under local anesthesia. Renal computed tomography angiography (CTA) and digital subtraction angiography (DSA) results showed bleeding of the right renal arteriovenous malformation, both nidus and aneurysm, which indicated that the patient had both cirsoid and cavernosal types of CRAVM. Endovascular management was chosen to treat the patient. The patient was cured and discharged, then followed-up for 3 months. These results show that early identification using radiologic tests is important for diagnosis and treatment of CRAVM.

A Successful Pregnancy after Laparoscopic Surgery: Severe Recurrent Pelvic Arteriovenous Malformation Managed by Laparoscopic Internal Iliac Artery Ligation

STUDY OBJECTIVE

To show a case of severe pelvic arteriovenous malformation (AVM) treated by laparoscopic internal iliac artery ligation after 2 uterine artery embolization (UAE) procedures, where successful pregnancy was achieved after surgery.

DESIGN

Stepwise demonstration of the technique with a video.

SETTING

Chinese PLA General Hospital.

INTERVENTIONS

A 36-year-old woman with heavy menstrual bleeding was diagnosed with pelvic AVM by computed tomography scan. Before surgical intervention, she underwent 2 UAE procedures that temporarily reduced menstrual blood loss. Finally, we performed a laparoscopic internal iliac artery ligation on her. After the surgery, she conceived naturally. During the cesarean section, no AVMs were found.

CONCLUSION

Laparoscopic internal iliac artery ligation can be a choice for patients who still have severe symptoms of AVM after UAE.

Successful retrograde transvenous embolization under balloon occlusion for rectal arteriovenous malformation

A 57-year-old man was admitted to our hospital because of frequent hematochezia. Colonoscopy exhibited a submucosal tumor-like lesion in the lower rectum. Abdominal contrast-enhanced computed tomography showed a rectal arteriovenous malformation (AVM) on the right side wall of the lower rectum. The feeder was the superior rectal artery, with early venous return. Embolization of the draining vein and feeding artery of the AVM with N-butyl-2-cyanoacrylate under balloon occlusion was planned. Angiography of the superior rectal artery showed the nidus in the rectum with early venous return of contrast material. The portal vein was punctured percutaneously under ultrasound guidance, and a balloon catheter advanced to the distal part of the superior rectal vein. Venography under balloon occlusion showed the outflow vein and nidus. Transvenous and transarterial nidus embolization with N-butyl-2-cyanoacrylate under balloon occlusion was then performed. Since the embolization, there have been no further episodes of bleeding. There is no established treatment for AVMs. Successful treatment requires targeting and eradication of the nidus. We successfully performed embolization therapy for a rectal AVM via a retrograde transvenous approach. This technique may be suitable for completely eradicating the nidus without the risk of embolism.

Uterine arteriovenous malformation - Possible association to uterine fibroids?

A 32-year-old, gravida 2 para 0+1, was managed in Selayang Hospital, Selangor for uterine fibroids in pregnancy and placenta previa major. The lady went into preterm labour at 33 weeks, requiring emergency Caesarean section. Intraoperatively, we found a thinned-out bulge between the intramural uterine fibroids at the posterior uterine wall, which then perforated and was repaired. Persistent bleeding post operatively led to relaparotomy and hysterectomy. Histology of the uterus reported arteriovenous malformation (AVM). We postulate the possibility of these lesions coexisting with uterine fibroids. Screening for uterine AVMs in patients with fibroids may lead to early detection with option of embolization; deferring the need for hysterectomy.

A case of pancreatic arteriovenous malformation caused acute pancreatitis

Arteriovenous malformation (AVM) in the pancreas rarely causes acute pancreatitis. However, even when it does cause pancreatitis, the pathogenesis is unclear. A 61-year-old man was admitted to our hospital for acute pancreatitis. The findings of computed abdominal tomography, magnetic resonance imaging, and endoscopic ultrasonography revealed pancreatic AVM and hematoma in the tail of the pancreas. These lesions were suspected to be associated with pancreatitis. Although endoscopic retrograde pancreatography could not confirm hemosuccus pancreaticus, distal pancreatectomy was performed because of repeated pancreatitis. The histopathological findings of the resected specimen revealed rupture of the AVM vessels into the main pancreatic ducts. Finally, we considered that intermittent bleeding due to AVM rupture and hematoma formation in the main pancreatic duct caused the repeated pancreatitis.

Location of embolization affects patency after coil embolization for pulmonary arteriovenous malformations: importance of time-resolved magnetic resonance angiography for diagnosis of patency

OBJECTIVES

This study aimed to assess the diagnostic accuracy of computed tomography (CT) and time-resolved magnetic resonance angiography (TR-MRA) for patency after coil embolization of pulmonary arteriovenous malformations (PAVMs) and identify factors affecting patency.

METHODS

Data from the records of 205 patients with 378 untreated PAVMs were retrospectively analyzed. Differences in proportional reduction of the sac or draining vein on CT between occluded and patent PAVMs were examined, and receiver operating characteristic analysis was performed to assess the accuracy of CT using digital subtraction angiography (DSA) as the definitive diagnostic modality. The accuracy of TR-MRA was also assessed in comparison to DSA. Potential factors affecting patency, including sex, age, number of PAVMs, location of PAVMs, type of PAVM, and location of embolization, were evaluated.

RESULTS

The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of CT were 82%, 81%, 77%, 85%, and 82%, respectively, when the reduction rate threshold was set to 55%, which led to the highest diagnostic accuracy. The sensitivity, specificity, PPV, NPV, and accuracy of TR-MRA were 89%, 95%, 89%, 95%, and 93%, respectively. On both univariable and multivariable analyses, embolization of the distal position to the last normal branch of the pulmonary artery was a factor that significantly affected the prevention of patency.

CONCLUSIONS

TR-MRA appears to be an appropriate method for follow-up examinations due to its high accuracy for the diagnosis of patency after coil embolization of PAVMs. The location of embolization is a factor affecting patency.

KEY POINTS

• Diagnosis of patency after coil embolization for pulmonary arteriovenous malformations (PAVMs) is important because a patent PAVM can lead to neurologic complications. • The diagnostic accuracies of CT with a cutoff value of 55% and TR-MRA were 82% and 93%, respectively. • The positioning of the coils relative to the sac and the last normal branch of the artery was significant for preventing PAVM patency.

A Case of Uterine Arteriovenous Malformation Treated With Uterine Artery Embolization

Uterine arteriovenous malformation (AVM) is a rare condition that is potentially life-threatening. There are limited published reports on this condition. This is a case report of a 25-year-old woman who presented with a symptomatic AVM. We review the differential diagnoses, evaluation, and treatment options. Conservative treatment with interventional radiology can be considered in select women who desire fertility preservation.

Endovascular treatment for the flow-related aneurysm originating from an anterior inferior cerebellar artery supplying the cerebellar arteriovenous malformation

BACKGROUND

When a flow-related aneurysm originates from an anterior inferior cerebellar artery (AICA) supplying the cerebellar arteriovenous malformation (AVM), the management becomes very complicated. Endovascular treatment (EVT) was an option, but no consensus has been achieved.Methods and materials: A retrospective investigation was performed for patients with flow-related aneurysm originating from an AICA supplying the cerebellar AVM.

RESULTS

Ten patients, harboring 13 aneurysms, were identified. Of the 5 a1 aneurysms, 2 underwent stent assisted coiling, 2 underwent parent artery occlusion (PAO), and 1 was intact. Of the 8 a2 aneurysms, 3 underwent coiling with preservation of the AICA, 3 underwent PAO with Onyx, 1 underwent PAO with coils, and 1 was intact. Seven patients underwent partial embolization of the cerebellar AVM, 3 were intact. One patient died 6 hours postoperatively for cerebellar AVM rebleeding. During a follow-up from 6 months to 6 years, 9 patients had favorable recovery.

CONCLUSION

For the flow-related aneurysm originating from an AICA supplying the cerebellar AVM, the EVT depends on the specific circumstances. When the aneurysm is located at the a1 segment, coiling of the aneurysm with preservation of the parent AICA should be performed. PAO is the last resort. When the a2 aneurysm is proximal to the internal auditory artery, coiling of the aneurysm with preservation of the AICA is preferred. When the aneurysm is distal to the internal auditory artery, PAO can be safely performed.

Fast TWIST with iterative reconstruction improves diagnostic accuracy of AVM of the hand

Very high temporal and spatial resolution is mandatory for the diagnosis of arteriovenous malformations (AVM) of the hand. Until now, magnetic resonance imaging (MRI) has not fulfilled both requirements simultaneously. This study presents how the combination of a very fast TWIST MRI (time-resolved angiography with interleaved stochastic trajectories) sequence and iterative reconstructions optimizes temporal as well as spatial resolution. 11 patients were examined at a 3-T MRI scanner with two different TWIST protocols: the standard and the study protocol, acquiring a data set every 5.57 s and 1.44 s respectively. The study data was retrospectively iteratively reconstructed with different regularization factors (0.001, 0.002, 0.004, 0.008). Results were compared using the sign-test. P-values < 0.05 were regarded statistically significant. With a low amount of contrast medium, the temporal resolution of the study protocol enabled the differentiation of arteries from veins in all patients whereas the signal-to-noise ratio (SNR) deteriorated. Depending on the regularization factors, SNR, delineation of arterial feeders and non-involved hand and interdigital arteries, as well as artefact levels varied. Overall, iterative reconstruction with regularization factor 0.004 achieved the best results, consequently showing the ability of MRI as a reliable diagnostic method in AVMs of the hand.

Wall Shear Stress in the Feeding Native Conduit Arteries of Superficial Arteriovenous Malformations of the Lower Face is a Reliable Marker of Disease Progression

PURPOSE

 To assess the prognostic value of the wall shear stress (WSS) measured in the feeding native arteries upstream from facial superficial arteriovenous malformations (sAVMs). Reliable prognostic criteria are needed to distinguish progressive from stable sAVMs and thus support the indication for an aggressive or a conservative management to avoid severe facial disfigurement.

MATERIALS AND METHODS

 We prospectively included 25 patients with untreated facial sAVMs, 15 patients with surgically resected sAVMs and 15 controls. All had undergone Doppler ultrasound examination (DUS) with measurements of inner diameters, blood flow velocities, computation of blood flow and WSS of the feeding arteries. Based on the absence or presence of progression in clinical and imaging examinations 6 months after, we discriminated untreated patients as stable or progressive.

RESULTS

 WSS in the ipsilateral external carotid artery was higher in progressive compared to stable sAVMs (15.8 ± 3.3dynes/cm² vs. 9.6 ± 2.0dynes/cm², mean±SD, p < 0.0001) with a cut-off of 11.5dynes/cm² (sensitivity: 92 %, specificity: 92 %, AUC: 0.955, [95 %CI: 0.789-0.998], p = 0.0001). WSS in the ipsilateral facial artery was also higher in progressive compared to stable sAVMs (50.7 ± 14.5dynes/cm² vs. 25.2 ± 7.1dynes/cm², p < 0.0001) with a cut-off of 34.0dynes/cm² (sensitivity: 100 %, specificity: 92 %, AUC: 0.974, [95 %CI: 0.819-1.000], p = 0.0001). The hemodynamic data of operated patients were not different from those of the control group.

CONCLUSION

 WSS measured in the feeding arteries of an sAVM may be a simple reliable criterion to distinguish stable from progressive sAVMs. This value should be considered to guide the therapeutic strategy as well as the long-term follow-up of patients with facial sAVMs.

Cesarean scar pregnancy combined with arteriovenous malformation successfully treated with transvaginal fertility-sparing surgery: A case report and literature review

INTRODUCTION

A cesarean scar pregnancy (CSP), when combined with an arteriovenous malformation (AVM), is a rare, but potentially life-threatening condition that may be associated with uncontrolled hemorrhage. Hysterectomy is indicated when conservative treatment fails. Preservation of fertility is challenging.

PATIENT CONCERNS

We reported a 33-year-old woman with a CSP combined with an AVM who failed methotrexate administration as conservative treatment.

DIAGNOSES

A CSP combined with an AVM was diagnosed via three-dimensional color Doppler angiogram and magnetic resonance imaging.

INTERVENTIONS

Transvaginal removal of the ectopic gestation and repair of the uterine defect was performed without incident.

OUTCOMES

The fertility of the patient was preserved and hysterectomy was avoided.

CONCLUSION

Transvaginal fertility-sparing surgery may be successfully performed to prevent hysterectomy when conservative treatment fails in patients with a CSP combined with an AVM.

Superselective Arterial Embolization of Arteriovenous Malformation of Internal Pudendal Artery, a Rare Cause of Hematuria: A Case Report

Arteriovenous malformation (AVM) is a common form of vascular malformation, an abnormal direct communication between an artery and a vein without passing through the capillaries. AVM may just present as hematuria without plain or other symptoms. The article presents a case of a 52-year-old male with gross hematuria diagnosed as AVM of internal pudendal artery, which was successfully managed with superselective arterial embolization using temporary embolization materials.

Gastrointestinal bleeding in a pancreatic arteriovenous malformation successfully treated by transarterial embolization

Pancreatic arteriovenous malformation (PAVM) is a rare case of upper gastrointestinal bleeding (UGIB), but it must be recognized in clinical practice, as it may be a potentially lethal condition in case of rupture and haemorrhage. This anatomic alteration is extremely rare as less than a hundred cases are reported in the scientific literature. The aim of this work is to report a case of PAVM presented as upper gastrointestinal bleeding (UGIB) and successfully treated by transarterial embolization.

Capillary-venule malformation is a microfistulous variant of arteriovenous malformation

OBJECTIVE

To describe typical clinical presentation of patients with microfistular, capillary-venule (CV) malformation as a variant form of arteriovenous malformations (AVM).

METHODS

A retrospective clinical analysis of 15 patients with CV-AVM confirmed by a computational flow model enrolled in a prospective database of patients with congenital vascular malformation between January 2008 and May 2018.

RESULTS

The mean age of the patients at first time of presentation was 30 years with balanced sex ratio. Presentation was dominated by soft tissue hypertrophy (n = 12 [80.0%]) and atypical varicose veins (n = 11 [73.3%]). The anatomic location of enlarged varicose veins gave no uniform pattern and did not correspond with the typical picture of primary varicose vein disease. Most often, symptomatic CV-AVM was found at the lower extremities in this series of unselected patients. The most frequent compartment affected was the subcutis (n = 14 [93.3%]), involvement of muscle was recorded in one-third and cutis in one-fourth of patients.

CONCLUSIONS

A high grade of clinical suspicion is needed to recognize CV-AVM and to prevent inadequate therapy owing to missed diagnosis.

Paravesical space arteriovenous malformation as a specific subgroup of pelvic vascular anomaly: a case series and review of literature

Treatment of pelvic arteriovenous malformations (AVMs) is frequently challenging because of the complex structures and anatomical diversity among cases. We present a case series of six patients with pelvic AVMs. All patients had a similar anatomical structure consisting of multiple feeders from the unilateral internal iliac artery, collecting into a dilated venous sac in the unilateral paravesical space and draining into a single outflow, eventually joining the pre-prostatic vein or internal iliac vein. Five among these patients were successfully treated by catheter-directed embolo-sclerotherapy. In addition to our six cases, we identified six previous case reports of pelvic AVM with similar anatomical characteristics. Herein, we summarize the clinical and anatomical features of these 12 paravesical AVM cases. In all cases, the patients were men; the AVM was predominantly located at the right paravesical space and demonstrated good therapeutic effect of catheter-directed embolosclerotherapy. These paravesical AVMs may constitute a new subgroup of pelvic vascular anomalies with the same etiology that are treatable by adequate catheter intervention.

Soft-Tissue Tumors of the Hand-Imaging Features

Imaging studies of the hands and fingers are common, and radiologists are generally comfortable with traumatic and degenerative conditions which arise frequently in daily practice. However, a variety of common and uncommon soft-tissue tumors also occur in the hand, the appropriate diagnosis of which can be a source of confusion for both clinicians and radiologists. These lesions often have overlapping imaging characteristics; however, a structured approach can help provide a focused differential diagnosis and impact further workup and management. We discuss several such tumors, categorizing them as cystic-appearing, noncystic masses along tendons and aponeuroses, adipocytic tumors, vascular lesions, and miscellaneous lesions with imaging features that can aid diagnosis.

[Endovascular embolization of spinal intramedullary arteriovenous malformation at the cervical level: case report and literature review]

We report a successful endovascular treatment of complex arteriovenous malformation of the spinal cord at the cervical level. The strategy, technical aspects and the main principles of embolization of arteriovenous malformation are considered in the article.

Pulmonary arteriovenous malformation managed by VATS lobectomy

Pulmonary arteriovenous malformation (PAVM) is formed by abnormal connections between pulmonary arteries and veins that bypass the pulmonary capillaries and transport deoxygenated blood through pulmonary veins to the left heart. This causes insufficient oxygenation of blood in the lungs. This condition remains symptomless for a long period of time. The most common symptoms include shortness of breath on exertion, nosebleeds, increased fatigue and a gradual development of cyanosis. Paradoxical embolism in the brain is a serious complication; it can present with a stroke or a brain abscess. Treatment of the disease consists of embolization of the pathological vascular connections, surgical resection of the affected pulmonary parenchyma and management of concomitant manifestations of the disease. PAVM in most common cases arises as a result of an autosomal dominant hereditary disorder referred to as hereditary hemorrhagic telangiectasia.  Case report: In our communication, we document the diagnostic and therapeutic management in a young patient diagnosed with PAVM after falling off his bicycle. Based on comprehensive assessments, AV malformations with a 40% shunt of the pulmonary circulation were detected. An angiographic procedure was not an appropriate option considering the type and extent of the condition. Therefore, video-assisted thoracic resection of the affected pulmonary lobe was indicated. Conclusion: PAVM is a rare finding. PAVM should be ruled out in all patients with hereditary hemorrhagic telangiectasia (HHT) signs in the oral cavity. Contrast sonography of the heart and contract CT of the chest are the methods of choice for the diagnosis. Conservative or pharmacological treat-ment fails to improve the patients status.  The condition is usually managed by embolization. Cases where PAVM is rather extensive or diffuse, where endovascular management would be inappropriate, can be well managed using endoscopic resection adequate to the extent of the condition.

Successful Percutaneous Treatment of an Arteriovenous Malformation of the Toe

Arteriovenous malformations (AVMs) of the toe are a rare entity. To the author's knowledge, there are only 2 published case reports, and both patients underwent amputation of the affected digits. Little is known about the optimal treatment of AVMs involving the toe. The authors present the case of a 20-year-old male with a large AVM of the second toe, which was successfully treated with intra-arterial sodium tetradecyl sulfate. Percutaneous treatment of these lesions is possible and should be considered before amputation.

Efficacy and Tolerance of Sirolimus (Rapamycin) for Extracranial Arteriovenous Malformations in Children and Adults

Managing extracranial arteriovenous malformations is challenging. Sirolimus (rapamycin) is increasingly being used when surgery and embolization are not advised. Because of its anti-angiogenic properties here we report all extracranial arteriovenous malformation cases treated with sirolimus in 2 French tertiary centers for vascular anomalies. The outcomes were efficacy (complete, partial, no response) based on arteriovenous malformation volume and necrosis/hemorrhage and side effects. We retrospectively included 10 patients (7 children). The sirolimus dose ranged from 0.6 to 3.5 mg/m2. Median (interquartile range [IQR]) treatment time was 24.5 (4.5; 35) months. Five patients showed no response and 5 showed partial response at a median (IQR) of 3 (1; 5) months followed in 2 cases by therapeutic resistance (i.e., progressive disease after 9 and 24 months of treatment). The most frequent side effect was mouth ulcers. This study shows poor efficacy of sirolimus for treating extracranial arteriovenous malformations.

Comparative Analysis of Volumetric High-Resolution Heavily T2-Weighted MRI and Time-Resolved Contrast-Enhanced MRA in the Evaluation of Spinal Vascular Malformations

BACKGROUND AND PURPOSE

Volumetric high-resolution heavily T2-weighted imaging or time-resolved contrast-enhanced MRA is used in the detection and characterization of spinal vascular malformations, though inherent trade-offs can affect their overall sensitivity and accuracy. We compared the efficacy of volumetric high-resolution heavily T2-weighted and time-resolved contrast-enhanced images in spinal vascular malformation diagnosis and feeder characterization and assessed whether a combined evaluation improved the overall accuracy of diagnosis.

MATERIALS AND METHODS

Twenty-eight patients with spinal vascular malformations (spinal dural arteriovenous fistula, spinal cord arteriovenous malformation, and perimedullary arteriovenous fistula) were prospectively enrolled. MR images were separately analyzed by 2 neuroradiologists blinded to the final diagnosis.

RESULTS

Both sequences demonstrated 100% sensitivity and 93.5% accuracy for the detection of spinal vascular malformations. Volumetric high-resolution heavily T2-weighted imaging was superior to time-resolved contrast-enhanced MR imaging for identification of spinal cord arteriovenous malformations (100% versus 90% sensitivity and 96.7% versus 93.5% accuracy), however, for the diagnosis of perimedullary arteriovenous fistula, time resolved contrast enhanced MRI was found to perform better than the volumetric T2 sequence (80% versus 60% sensitivity and 96.7% versus 93.5% accuracy). Both sequences showed equal sensitivity (100%) and accuracy (87%) for spinal dural arteriovenous fistulas. Combined evaluation improved the overall accuracy across all types of spinal vascular malformation. Volumetric high-resolution heavily T2-weighted imaging was superior or equal to time-resolved contrast-enhanced MR imaging for feeder identification of spinal dural arteriovenous fistulas for both observers (90.9% and 72.7% versus 72.7%), which improved to 90.9% when the sequences were combined. Time-resolved contrast-enhanced MR imaging performed better for major and total feeder identification of spinal cord arteriovenous malformation (80% versus 60%) and perimedullary arteriovenous fistula (80% versus 60%-80%).

CONCLUSIONS

Combined volumetric high-resolution heavily T2-weighted imaging and time-resolved contrast-enhanced MR imaging can improve the sensitivity and accuracy of spinal vascular malformation diagnosis, classification, and feeder characterization.

Spontaneous massive haemothorax in the peri-partum period of an undiagnosed neurofibromatosis type 1 patient - A surgical perspective

Acute massive haemothorax is a life-threatening situation, which is often associated with a preceding trauma. However, spontaneous haemothorax is a rare occurrence, especially in pregnancy. Spontaneous haemothorax in the immediate post-partum period secondary to a ruptured intercostal AVM is extremely rare more so in the background of an undiagnosed neurofibromatosis. This is a report of a young lady presenting with pleuritis and breathlessness after the delivery of her 1st child. Her management is discussed.

[An Unusual Hemisphere Syndrome]

An Unusual Hemisphere Syndrome Abstract. A patient with known hereditary hemorrhagic telangiectasia presents with transient right arm weakness and dizziness. A transient ischemic attack is diagnosed on clinical and risk factors. In the course of the disease, the patient suffers a convulsive event and fever occurs twice without a clear focus on the infection. The initial skull MRI shows a centroparietal lesion on the left with signs of accompanying edema. Due to this unusual concomitant edema, a neoplastic event must also be considered for differential diagnosis. However, the further examinations show no evidence of neoplasia, but the course MRI of the skull shows the image of septic embolisms with a brain abscess. After neurosurgical remediation and appropriate antibiotic treatment, the clinical course is pleasing. The cause of the septic embolisms was a pulmonary arteriovenous malformation due to hereditary hemorrhagic telangiectasia, which could be coiled without complications.

[Arteriovenous malformations and its complex management]

Congenital arteriovenous malformations (AVM) represent a rare clinical entity. They are present at birth but can remain silent for many years. Due to their potential severity and their complex and specific management, the general practitioner should know when to suspect the presence of an AVM. Anatomic and hemodynamic characteristics of these malformations are well analysed by Doppler ultrasound, which is the first-line diagnostic test. MRI is often used in conjunction with ultrasound to better define the location and extension to neighbouring tissues and organs. Embolisation should be restricted to AVM associated with major functional disability, local complications or systemic cardiac complications in case of high flow volume life-threatening lesions.

A Surgical Case of Inferior Mesenteric Arteriovenous Malformation

The treatment option for inferior mesenteric arteriovenous malformations is under debate because of the number of cases. We, herein, report about a 35-year-old man with congenital inferior mesenteric artery malformation (AVM) presenting with mucous stool and severe abdominal pain. The radical operation, after building the diverting stoma, minimized the extent of the resection. This is the first reported case where surgical management was used to control severe symptoms induced by inferior mesenteric AVM.

Pulmonary arteriovenous malformations

Pulmonary arteriovenous malformation, a condition most commonly associated with hereditary hemorrhagic telangiectasia, is an abnormal communication between the pulmonary artery and pulmonary vein without an intervening capillary communication. Although asymptomatic in ~ 50% individuals, it can present with the dreaded complications of stroke or intracranial abscess in high-risk individuals including pregnant women, if untreated. The mainstay of treatment is now endovascular embolization of the feeding artery which can alleviate the symptoms and prevent these complications. In this review, we describe the pathophysiology, methods of screening, diagnostic workup and treatment of these vascular lesions with a particular focus on the currently used embolization techniques and their outcomes.

Spontaneous Resolution of an Acquired Uterine Arteriovenous Malformation in an Elderly Primigravida

BACKGROUND Uterine arteriovenous malformation (AVM) is an uncommon lesion characterized by an abnormal connection between arterial and venous circulation that can be congenital or acquired. Acquired uterine AVMs are generally traumatic and follow delivery, abortion, curettage, or uterine surgery. CASE REPORT A 45-year-old female who was gravida 1 para 0 presented to our hospital with severe vaginal bleeding. Two weeks before, the patient underwent therapeutic abortion. At admission, a transvaginal ultrasound showed an unclear intrauterine lesion that spread out to the myometrium. Color Doppler evaluation demonstrated an elevated color score. Beta human chorionic gonadotropin (beta-hCG) levels were measured at admission and daily repeated, with a progressive decrease of values up to a negative level. A pelvic magnetic resonance imaging described an area of tubular and tortuous structures involving the myometrium. A computed tomography angiography confirmed the presence of a lesion infiltrating the endometrium and myometrium containing arteriovenous structures with a highly enhanced effect. Despite these findings, the patient was clinically stable. A diagnosis of uterine AVM was made and, after accurate counselling with the patient, she was discharged and underwent "watch and wait" management. After 35 days, the patient had a follow-up ultrasound that showed a complete resolution of the uterine lesion. CONCLUSIONS AVM should be considered in the presence of heavy and sudden vaginal bleeding in a patient with risk factors for acquired AVM. A color Doppler ultrasound scan should be performed as the first approach and an expectant management should be taken into account especially with a patient of childbearing age and hemodynamic instability.

The philosophy of 'unity of knowledge and action' in interventional neuroradiology teaching

Despite the continuing emphasis on the importance of clinical skills, these skills do not appear to be improving and may actually be declining. The 'unity of knowledge and action' is a medicine directed precisely at this disease. The 'unity of knowledge and action' helps to learn from failure and successes, learn from mistakes of predecessors and institute a behaviour that prevents repetition of these mistakes.

Micro-arteriovenous malformation causing spontaneous metacarpal pad hemorrhage in a dog

A 5-year-old neutered male Labrador retriever dog with a 3-year history of intermittent hemorrhage from the right metacarpal pad was evaluated. A small region of hyperattenuation of the metacarpal pad was evident on computed tomographic angiography. Excisional biopsy of the location of the purported hemorrhage revealed a micro-arteriovenous malformation on histologic examination.

Massive Hematuria Due to Congenital Renal Arteriovenous Malformation Successfully Treated by Renal Artery Embolization

Congenital renal arteriovenous malformations (AVMs) are rare benign vascular lesions and a rare cause of massive hematuria in females predominantly involving right kidney. Clinical presentation in a male with involvement of the left kidney is very rare. Only a few case series describing the outcome of congenital renal AVMs have been reported in the literature. We report a challenging case of a male patient with life threatening massive hematuria with congenital renal AVMs in left kidney. Successful embolization was performed using coils and gel foam.

Utility of second-generation single-energy metal artifact reduction in helical lung computed tomography for patients with pulmonary arteriovenous malformation after coil embolization

PURPOSE

The quality of images acquired using single-energy metal artifact reduction (SEMAR) on helical lung computed tomography (CT) in patients with pulmonary arteriovenous malformation (PAVM) after coil embolization was retrospectively evaluated.

MATERIALS AND METHODS

CT images were reconstructed with and without SEMAR. Twenty-seven lesions [20 patients (2 males, 18 females), mean age 61.2 ± 11.0 years; number of embolization coils, 9.8 ± 5.0] on contrast-enhanced CT and 18 lesions of non-enhanced lung CT concurrently performed were evaluated. Regions of interest were positioned around the coils and mean standard deviation value was compared as noise index. Two radiologists visually evaluated metallic coil artifacts using a four-point scale: 4 = minimal; 3 = mild; 2 = strong; 1 = extensive.

RESULTS

Noise index was significantly improved with SEMAR versus without SEMAR (median [interquartile range]; 194.4 [161.6-211.9] Hounsfield units [HU] vs. 243.9 [220.4-286.0] HU; p < 0.001). Visual score was significantly improved with SEMAR versus without SEMAR (Reader 1, 3 [3] vs.1 [1]; Reader 2, 3 [3] vs.1 [1]; p < 0.001). Significant differences were similarly demonstrated on lung CT (p < 0.001).

CONCLUSION

SEMAR provided clear chest CT images in patients who underwent PAVM coil embolization.

Polidocanol Sclerotherapy Combined with Transarterial Embolization Using n-Butyl Cyanoacrylate for Extracranial Arteriovenous Malformations

Purpose

To assess the safety and effectiveness of polidocanol sclerotherapy combined with transarterial embolization using a liquid adhesive agent (n-butyl cyanoacrylate, NBCA) for treatment of extracranial arteriovenous malformations (AVMs).

Materials and Methods

Twenty-three patients with symptomatic AVMs in the head and neck (6), upper (7) and lower extremity (10) with a mean age of 42 years (range 4–74) treated with polidocanol sclerotherapy were retrospectively assessed. AVMs were classified according to the angiographic morphology of the nidus. There were 2 type I, 6 type II, 6 type IIIa and 9 type IIIb. Arterial embolization using NBCA was performed to reduce arterial flow before sclerotherapy. Polidocanol mixed with contrast material or carbon dioxide was delivered by percutaneous direct puncture.

Results

Treatment was successfully performed in all patients. In the mean follow-up period of 38 months, symptoms resolved or improved in 20/23 patients (87.0%). AVMs were devascularized 100% in 2 patients, 76–99% in 13, 50–75% in 7 and < 50% in 1. More than 50% devascularization was seen in 22 patients (95.6%). Two (8%) patients had complete remission, 17 (74%) had partial remission and 3 (13%) had no remission. There was no aggravation. Treatment was considered effective (complete and partial remission) in 20 patients (87.0%). Minor complications including localized arterial thrombosis (2) and spontaneously healing skin ulcer (1) were seen in 2 patients (8.7%). There were no major procedure-related complications.

Conclusion

Polidocanol sclerotherapy combined with transarterial embolization using NBCA is safe and effective for treating extracranial AVMs with an acceptable risk of minor complications.