High-flow Lesions Research Articles

Preliminary Experimental Evaluation of the Immediate Angiographic Occlusion Time with Use of the AMPLATZER Vascular Plug II for Carotid Artery Occlusion

Delayed occlusion time in parent artery occlusion of brain-supplying vessels might carry risk for thromboembolic complications. Vascular plug devices are successfully used in cardiopulmonary and peripheral interventions to occlude high-flow lesions and have been adapted for use in neurointerventions. The purpose of the present study was to experimentally evaluate the immediate occlusion time of the AMPLATZER vascular plug (AVP) II-a second-generation cylindrical, self-expandable, resheathable nitinol wire mesh consisting of three lobes-in the carotid artery. AVP II devices (N = 12) 6 mm in diameter (length, 6 mm) were deployed through 6-F guiding catheters in the common carotid arteries of two pigs. After device deployment, angiography was performed to measure the time interval until no contrast agent opacification was visible distal to the AVP II, indicating complete flow cessation and occlusion of the distal vessel. Vessel diameters before deployment and after resheathing of the device were measured. Device navigation, positioning, recapturing, vasospasm, and angiographic signs of vessel injury were assessed. The mean time to total flow cessation and occlusion was 57.9 seconds (median, 44 s ± 27 [SD]; range, 26-104 s). Device navigation, positioning, and resheathing were successful in all cases. There was neither significant vasospasm nor vessel injury visible on angiography. Application and retrieval of the second-generation AVP II are uncomplicated and the device is able to achieve fast and sufficient cessation of flow in a hemodynamically comparable setting to the human carotid artery, indicating some potential to fill a gap in the neurointerventional tool box.

PAVM Embolization: An Update

Pulmonary arteriovenous malformations (PAVMs) are most often associated with hereditary hemorrhagic telangiectasia. Untreated, they represent a serious threat due to paradoxical embolization that may manifest as stroke or brain abscess. PAVM treatment is challenging even in the most experienced hands. Fortunately, new tools and techniques are emerging that may improve the outcomes associated with embolization and reduce some of the risks associated with treating these high-flow lesions. New trends in overall PAVM management are also developing.

Current concepts in the classification, diagnosis and treatment of vascular anomalies

Patients with extended vascular anomalies may suffer from significant aesthetic and functional impairment and represent a challenge to therapeutic planning, which is best met by an interdisciplinary concept. In agreement with the International Society for the Study of Vascular Anomalies (ISSVA), vascular lesions are classified into haemangiomas as proliferating endothelial tumours on the one hand and congenital vascular malformations on the other. According to the preponderant vascular channels and hemodynamic characteristics, malformations are subdivided into low flow (venous, lymphatic and capillary) lesions and high-flow malformations. Diagnostic imaging should be targeted at the specific structural and functional informations required for treatment planning. The imaging modality of choice to provide these informations is magnetic resonance imaging (MRI) supplemented by magnetic resonance angiography (MRA) with high spatial and temporal resolution. Treatment indications for haemangiomas depend on the proliferative behaviour of the lesion and comprise β-blockers in order to induce involution as well as cryotherapy, laser and open surgery. Interventional radiological procedures have evolved as an essential element in an interdisciplinary treatment plan for vascular malformations and include percutaneous sclerotherapy with ethanol and OK-432 for venous and lymphatic malformations and transarterial embolization for high-flow lesions.

Intraoral Excision of Arteriovenous Malformation of Lower Lip

Vascular malformations can be categorized into low-flow lesions and high-flow lesions according to blood flow volume. Arterial lesions such as arteriovenous malformations (AVMs) are generally high-flow lesions. Arteriovenous malformations are high-flow vascular anomalies consisting of a nidus or a network of abnormal vascular channels between feeding arteries and draining veins. Arteriovenous malformations become destructive progressively by compression or erosion of surrounding tissue by itself. Angiography is the most important diagnostic technique for determination of location and flow characteristics of vascular lesions. Embolization is used preoperatively to decrease the size of AVM and reduce the extent of surgical excision. The modern treatment of AVM requires multidisciplinary study between the surgeon and vascular radiologist. We reported an early diagnosed AVM at the lower lip, and it was resected totally intraorally without any complication and morbidity.

Clinical Features and Classification of Brain AVMs and Cranial DAVFs

The clinical findings of intracranial vascular malformations are strictly related to their morphologic, angioarchitectural and hemodynamic characteristics. An overall study of these features is the first step to understand the different classifications for arteriovenous malformations, dural arteriovenous fistulas and carotid-cavernous fistulas. This evaluation will also suggest the correct timing of endovascular treatment and which part of the lesion should be the target of the therapy. Conventional cerebral angiography is mandatory when a correct classification of intracranial arteriovenous malformative shunts must be achieved. The angioarchitectural classification of brain arteriovenous malformations considers all angiographic features of each component of the malformation, both morphologically and hemodynamically, and relates them to the clinical course of the disease. The correlation between clinical findings, angiographic features and classifications is even stronger for cranial dural arteriovenous fistulas, in which cortical venous drainage is typical of "aggressive" fistulas and is usually absent in the "benign" type. Similarly, carotid-cavernous fistulas can be differentiated at angiography into high or low flow lesions according to the flow rate of the shunt, and into direct or indirect fistulas, according to the origin of arterial feeders. This paper focuses on the existing relation between the hemodynamics of brain arteriovenous malformations, cranial dural arteriovenous fistulas, carotid-cavernous fistulas, and their most frequent clinical findings, through an analysis of the most widely used different classification systems.

The Use of Onyx for Embolization of Central Nervous System Arteriovenous Lesions in Pediatric Patients

The safety and efficacy of Onyx for the embolization of central nervous system (CNS) arteriovenous (AV) lesions have been widely reported in adults. However, data describing the use of this agent in children are limited. This study presents our experience with Onyx in the treatment of CNS AV lesions in pediatric patients. We retrospectively analyzed clinical and imaging records of 15 pediatric patients who underwent 36 transarterial embolizations by using Onyx for CNS AV lesions, from March 2007 through April 2009 at our institution. Underlying pathologies included brain AV malformations (AVMs) (n = 7), vein of Galen malformations (n = 4), dural AV fistulas (n = 2), and spinal AVMs (n = 2). For 7 procedures in very high-flow lesions, detachable coils were deployed before Onyx embolization, whereas in 29 procedures, Onyx was the sole embolic agent. The efficacy of embolization was judged by the residuum of AV shunting within the target region. Embolization was complete in 2 patients, nearly complete in 9 patients, and partial (and ongoing) in 4 patients. Following staged embolization, 7 patients underwent surgical resection without significant blood loss and with good functional outcome in all cases. Clinically silent non-target embolization was encountered in 2 of 36 procedures. After 3 of the 36 embolizations, patients developed transient neurologic symptoms, all of which resolved to baseline within 24 hours. There were no non-neurologic adverse events. There was no imaging evidence of infarct or hemorrhage. Onyx embolization of pediatric CNS AV lesions can be an efficacious treatment technique, with extremely low associated morbidity.

Treatment of deep vascular orbital malformations

Objective In this article, we discuss the clinical features and endovascular and/or surgical treatment of deep vascular orbital malformations. Methods We report on our treatment of 58 cases of vascular malformations of the orbit between 1991 and 2008. Results Arterial low flow lesions, such as cavernomas ( n = 44) were the most common finding. These were treated by complete excision. High flow lesions such as angiomas were less common ( n = 4). These were treated by the endovascular and/or surgical approach. Venous flow lesions appear as distensible lesions ( n = 3) or non-distensible anomalies ( n = 4). Deep venous lesions ( n = 7) should be treated if they cause severe pain, progressive proptosis, motility disturbances or visual deterioration. No flow lesions include lymphangiomas ( n = 3). Surgery may be helpful in specific cases with intracystic haemorrhage and progressive proptosis. Patients with severe visual deterioration do not improve, whereas all other symptoms are potentially reversible. Conclusions Treatment of vascular malformations is required in case of progression of symptoms. In cases of visual deterioration, we generally favour early treatment. The least invasive surgical approach, tailored to the individual patient, should be chosen.

The Surgical Management of 73 Vascular Malformations and Preoperative Predictive Factors of Major Haemorrhage – A Single Centre Experience

In our series of patients with congenital vascular malformations (CVMs) we investigate the preoperative factors for predicting major haemorrhage at surgery and propose an algorithm for their surgical management. This is a partly prospective case series of patients with severe symptoms/complications due to CVMs. Data were collected on 73 consecutive procedures in 41 patients with CVMs from 1992 to 2006 at a large university hospital and the association of following factors with blood loss during the procedure were investigated: type of procedure, possibility of proximal tourniquet use, lesion flow characteristics, previous history of major haemorrhage with CVM surgery, platelet counts and length of hospital stay. Significantly higher blood loss was associated with debulking surgery (p=0.006) and with previous history of major haemorrhage during CVM surgery, (p=0.041). Blood loss was higher in lesions where proximal tourniquet application was not possible (p=0.093). High-flow lesions were not strongly associated with major blood loss (p=0.288). Major blood loss (>2l) occurred in 16 (20.8%) procedures performed on 11 (26.2%) patients, but this did not prolong hospital stay. Surgery can potentially improve morbidity/mortality in patients with life/limb-threatening complications or severe symptoms due to CVMs, providing they are managed in multidisciplinary specialised centres.

Characterization of a distinct syndrome that associates complex truncal overgrowth, vascular, and acral anomalies: a descriptive study of 18 cases of CLOVES syndrome

Overgrowth syndromes with complex vascular anomalies pose a challenge for diagnosis and management. The purpose of this descriptive study is to present a cohort of patients with congenital lipomatous overgrowth, vascular malformations, and epidermal nevi syndrome, a distinct clinical phenotype characterized by a complex truncal-lipomatous mass, vascular, acral, and other anomalies. This cohort was ascertained following review of patient data entered into the Vascular Anomalies Center database of the Children's Hospital, Boston over a period of 7 years. Clinical data, imaging findings, and the photographic archive were reviewed. The search identified 18 unrelated patients with a distinct phenotype. Variable portions of the truncal masses observed in these patients were composed of a lymphatic malformation. Capillary malformations and high-flow lesions were commonly encountered. The lipomatous mass infiltrated the adjacent anatomic spaces and was associated with capillary, lymphatic, venous, and arteriovenous vascular malformations. Paraspinal-intraspinal extension was associated with morbid sequelae. Acral deformities included large, wide feet and hands, macrodactyly, and a wide sandal gap. Scoliosis and other musculoskeletal, neurologic, renal, and cutaneous malformations were also encountered. The uniform and highly characteristic features of the truncal lipomatous mass, in combination with vascular, acral, and other anomalies, provide evidence of a distinct nosologic and clinical entity. Morbid sequelae of the truncal involvement in this condition can be deforming and disabling; hence, prompt diagnosis and multidisciplinary care are necessary.

Head and Neck Vascular Lesions: Characterization of the Flow Pattern by the Use of Three-Phase CT

ObjectiveThis study was designed to evaluate the usefulness of three-phase CT to characterize the hemodynamics of vascular lesions in the head and neck area.Materials and MethodsWe analyzed vascular malformations of head and neck regions in 21 patients with the use of three-phase CT, including pre-contrast phase, vascular phase (scan delay: 20-35 seconds after intravenous contrast material injection) and equilibrium phase (scan delay: 3-5 minutes) imaging. The flow characteristic of each lesion was determined and categorized as either a high- or a low-flow lesion according to findings on selective arteriography and/or direct puncture venography. The CT number was acquired from two areas in a vascular lesion, sorted by the enhancement pattern: area 1, a highly enhanced area seen on the vascular phase; area 2, a delayedly enhanced area seen on the equilibrium phase. The CT numbers of each phase were compared between high- and low-flow lesions with use of the unpaired t-test. The flow patterns of high- and low-flow lesions were analyzed by assessment of time-density curves of three phase CT.ResultsHigh-flow lesions were detected in nine patients and low-flow lesions were detected in 12 patients. On the vascular phase, the CT number of areas 1 and 2 of high-flow lesions was significantly higher than for low-flow lesions (p < 0.05). Contrary to early peaks seen in time-density curves of high-flow lesions, low-flow lesions showed a delayed peak.ConclusionThree-phase CT seems to be a valuable non-invasive method to differentiate a high-flow lesion from a low flow lesion of head and neck vascular lesions.

Treatment of Arteriovenous Malformations: Assessment of 2 Techniques—Transmandibular Curettage Versus Resection and Immediate Replantation

This study evaluates 2 surgical methods used at our center for the treatment of mandibular arteriovenous malformations (AVMs): resection with immediate replantation and curettage via proximal transmandibular osteotomy. Patients with AVMs of the mandible who were treated during a 17-year period between 1992 and 2008 at our department were assessed. Two surgical techniques were used for treatment: 1) resection of the segment, curettage of the intrabony lesion, extraction of involved teeth, and immediate replantation and 2) proximal osteotomy curettage of the lesion within the bone and extraction of involved teeth. In the replantation group the resected segment of the mandible was replanted after the contents were scraped out and the involved teeth removed. In contrast, in the proximal osteotomy group this was done without removal of the bone segment. In both techniques the cortical bone of the mandible was maintained. However, in the transmandibular curettage group the periosteum was not entirely stripped off because curettage was done via proximal osteotomy without removal of the segment. The entire intrabony lesion and a margin of cancellous bone related to the lesion were excised in both groups. The bone was fixed with titanium plates in all cases. All patients were followed up annually for a period of 1 to 17 years (mean, 9.5 years). We treated 12 patients with mandibular AVMs (2 male and 10 female patients). Their ages ranged from 7 to 17 years. Preoperative angiography showed high-flow central vascular lesions in all patients. Of the lesions, 7 (58%) were treated via resection with immediate replantation and 5 (42%) were treated via transmandibular curettage. Embolization was performed in 4 cases 48 hours before surgery. However, blood loss was not significantly decreased by embolization. The lesions were categorized as multilocular (58.3%) or unicystic (41.7%) based on the radiographic findings and were located in the mandibular body (66.7%) or ramus (33.3%). Blood loss averaged 1.60 L in the group undergoing resection and immediate replantation and 1.30 L in the transmandibular curettage group. During the follow-up period, no recurrences were encountered in either group via clinical, radiographic, or computed tomography scan assessment, and none of the patients had facial deformities develop. The results suggest that transmandibular curettage via proximal osteotomy without complete resection is an effective less invasive method with which to treat AVMs of the mandible provided that the lesion is small, is confined within the bone, and has not invaded the soft tissues. Less blood loss, preservation of the bone, more favorable postoperative esthetics, and better function are among the advantages of this technique. In more extensive cases and those involving both hard and soft tissues, resection with immediate replantation is recommended. Both techniques obviated the need for bone graft reconstruction. This technique is better than resection and discarding of the segment.

The challenge of large vascular malformations

Vascular malformations are of the low- or high-flow variety, the latter variety also having shunting characteristics. In this manuscript, significant and challenging conditions will be presented. The high-flow lesions can cause excessive growth in the local area, and severe bleeding is always a possibility, either spontaneous or during surgery. Clinical examination, angiography, and Doppler studies confirm the diagnosis. In treatment of the above-mentioned high-flow lesions, embolization is temporary and should be employed mainly as an aid prior to surgery. Nonpermanent material is used. At the time of resection, an inflow vessel is preserved for later embolization should there be a recurrence. Otherwise, treatment may be extremely hazardous with significant blood loss. Resection is performed post-embolization in order to reduce bleeding. Free tissue transfer is frequently needed post-resection. These procedures will often involve cooperation with neurosurgery, vascular surgery, maxillofacial surgery, or ENT surgery. Very occasionally, cardiac arrest and bypass may be necessary, but only after considerable assessment. This can result in severe blood loss in the warming phase. Sotradecol injections have been used during surgery to prevent bleeding in a sclerose-as-you-go technique. Free tissue transfer may produce a new vascular environment, and it is our impression that there is less recurrence after the use of this technique. When there is severe, almost uncontrollable bleeding, large sutures are used to compartmentalize the area and reduce the blood flow followed by injection of sclerosants. This can make resection feasible. Lymphovenous and venous malformations present their own problems. Intralesional therapy is the treatment of choice for these low-flow lesions. If this is unsuccessful, they can be resected but hemostasis can be difficult. All the therapeutic tricks may have to be used: compartmentalization, Sotradecol, and then resection. Again, there is always concern about recurrence.

Approche diagnostique et thérapeutique en imagerie des anomalies vasculaires de la main

Vascular lesions of the hand are challenging for diagnosis and treatment. These lesions are far more common than malignant tumors. Clinical presentation may be confusing and correct identification by imaging is sometimes mandatory. Standard X-rays and doppler ultrasound examination are the first modalities to be used. Doppler ultrasound help to characterize the lesion or/and to assess the flow velocity within the lesion. It allows to separate the high flow lesions (hemangioma, arteriovenous malformation) from the low or no flow lesions (venous malformation, cystic lymphangioma). MR imaging is the gold examination to define the size and the extension of the lesion to adjacent structures. Careful clinical and imaging evaluation and multidisciplinary staff decision are crucial before to propose embolotherapy and/or surgical treatment. In case of persistent doubt, a biopsy must be required. AVM must be excluded before to propose this biopsy sample. Interventional radiology can be used alone or in combination with surgery to treat vascular malformation (arteriovenous, lymphatic, venous, or mixed). Embolisation may either be done by percutaneous approach (all malformations) or by intravascular catheterization (arteriovenous malformation). Hemangioma is a benign tumor which most often spontaneously involutes with age. Vascular malformations of the hand are difficult to eradicate completely either with embolization or surgery or both. Recurrences are frequent. Management in multidisciplinary staff is mandatory and long follow-up is needed.

Transarterial and Transvenous Approach for Transcatheter Closure of a Large Coronary Artery Fistula with the Amplatzer Vascular Plug

Interventional occlusion of coronary artery fistulas has become a well-accepted alternative to surgical therapy. However, occlusion of high-flow lesions in children, necessitating implantation of large occluding devices, may be limited by the requirement of large delivery catheters. This report describes the interventional occlusion of a large coronary artery fistula in an 8-year-old girl. Complete occlusion was achieved by subsequent transvenous and transarterial implantation of two Amplatzer vascular plugs (AVP). The AVP is an interesting alternative for interventional occlusion of large coronary artery fistulas in children that can be deployed safely by rather small guiding catheters.

Management strategy for facial arteriovenous malformations

ABSTRACTArteriovenous malformations (AVMs) are uncommon errors of vascular morphogenesis; haemodynamically, they are high-flow lesions. Approximately 50% of AVMs are located in the craniofacial region. Subtotal excision or proximal ligation of the feeding vessel frequently results in rapid progression of the AVMs. Hence, the correct treatment consists of highly selective embolisation (super-selective) followed by complete resection 24-48 hours later. We treated 20 patients with facial arteriovenous malformation by using this method. Most of the lesions (80%) were located within the cheek and lip. There were no procedure related complications and cosmetic results were excellent.

Closing the gap between coil and balloon in the neurointerventional armamentarium? Initial clinical experience with a nitinol vascular occlusion plug

The use of vascular plug devices for the occlusion of high-flow lesions is a relatively new and successful procedure in peripheral and cardiopulmonary interventions. We report on the use and efficiency of the Amplatzer vascular plug in a small clinical series and discuss its potential for occlusion of large vessels and high-flow lesions in neurointerventions. Between 2005 and 2007 four patients (mean age 38.5 years, range 16-62 years) were treated with the device, in three patients to achieve parent artery occlusion of the internal carotid artery, in one patient to occlude a high-flow arteriovenous fistula of the neck. The application, time to occlusion, and angiographic and clinical results and the follow-up were evaluated. Navigation, positioning and detachment of the device were satisfactory in all cases. No flow-related migration of the plug was seen. The cessation of flow was delayed by a mean of 10.5 min after deployment of the first device. In the procedures involving vessel sacrifice, two devices had to be deployed to achieve total occlusion. No patient experienced new neurological deficits; the 3-month follow-up revealed stable results. The Amplatzer vascular plug can be adapted for the treatment of high-flow lesions and parent artery occlusions in the head and neck. In this small series the use of the devices was uncomplicated and safe. The rigid and large delivery device and the delayed cessation of flow currently limit the device's use in neurointerventions.

Vascular birthmarks

Vascular birthmarks can be classified into hemangioma and vascular malformations. Hemangioma are frequent tumours of early infancy demonstrating endothelial hyperplasia, a history of rapid neonatal growth and slow involution during later childhood. Treatment of hemangioma is dependent of stage and type of the lesion. Given the current availability of drugs, lasers, and other techniques to treat hemangioma safely, philosophy of "benign neglect" should not be considered anymore. Vascular malformations show a normal endothelial turnover, being present at birth and growing commensurately with the child. Exact diagnosis by employing modern diagnostic means,which are able to differentiate low-flow from high flow lesions is important for further therapeutic management. Beside conservative treatment strategies, use of laser, sclerotherapy, interventional embolization and surgical treatment are possible management options. Patients should receive multidisciplinary care in qualified vascular centres.

Management strategy for facial arteriovenous malformations.

Arteriovenous malformations (AVMs) are uncommon errors of vascular morphogenesis; haemodynamically, they are high-flow lesions. Approximately 50% of AVMs are located in the craniofacial region. Subtotal excision or proximal ligation of the feeding vessel frequently results in rapid progression of the AVMs. Hence, the correct treatment consists of highly selective embolisation (super-selective) followed by complete resection 24–48 hours later. We treated 20 patients with facial arteriovenous malformation by using this method. Most of the lesions (80%) were located within the cheek and lip. There were no procedure related complications and cosmetic results were excellent.

First documented case of a submandibular arteriovenous malformation in a male patient

Arteriovenous malformations (AVMs) are high-flow lesions of intercommunicating veins and arteries formed by abnormal vessel morphogenesis [1]. Most of the AVMs discussed in previous review articles are congenital lesions that became clinically apparent later in life, whereas acquired AVMs are rare and usually form posttraumatically [2]. Both types of AVMs may produce symptoms of pain, swelling, or discoloration, whereas some AVMs present solely as a mass lesion [3]. The 2 types differ in that congenital AVMs often have multiple communications between arteries and veins, whereas acquired lesions may be solitary arteriovenous communications [1]. Most AVMs are found in the extremities, lungs, and head and neck region, with head and neck lesions approaching 51% of all AVMs [4]. Head and neck lesions are usually intracranial and occur in 0.1% of the population [5]. In contrast, extracranial lesions are considered much more rare, and when they do occur, they are typically located at the carotid or vertebral arteries and can sometimes involve the mandibular bone [2]. Most cases of extracranial AVMs in the literature are cited in female patients with very few cases presenting in males. Furthermore, only 8 cases of submandibular AVMs have been cited in the literature, with all cases presenting in females. Treatment options for AVMs include transvenous or transarterial embolization, radiotherapy, or surgery. Although literature discussing the complications of these treatments is limited, complications that have been described include reperfusion bleeding, ischemic ulceration and necrosis, infection, numbness of the inferior alveolar

High-Flow Facial and Skull Base Lesions Resected Using Cardiopulmonary Bypass

Although cardiopulmonary bypass has been used previously in the resection of vascular malformations, the overall opinion on the few cases treated in this way has been somewhat negative. A small series of four cases will be presented; one case died after several years from uncontrolled bleeding. So far the other cases have survived in the long term and their clinical histories will be presented. One further case is being considered for this approach in the near future. The problems of this approach will be discussed.