A Rare Case of Cerebral Air Embolism Caused by Pulmonary Arteriovenous Malformation After Removal of a Central Venous Catheter.

Cerebral air embolism following central venous catheter (CVC) removal is extremely rare. We report a case of cerebral air embolism with loss of consciousness after removal of CVC caused by pulmonary arteriovenous malformation (PAVM). Computed tomography revealed air bubbles in the internal carotid arteries along the sulci in the cerebral hemispheres, as well as a PAVM. The cerebral air embolism was treated with hyperbaric oxygen and intravenous thrombolytic therapy, and transcatheter embolization of the PAVM was performed. When inserting/removing CVC in a patient with a small PAVM, treatment of the PAVM, irrespective of its size, could prevent the type of complication that occurred in our present case.

A Retrograde Transvenous Embolization Technique with Balloon-Assisted Arterial Aspiration for a Peripheral Arteriovenous Malformation with a Venous Pouch.

Management of arteriovenous malformations (AVMs) is challenging, and there is no consensus regarding either the ideal approach or the treatment timing. Percutaneous embolization is the most frequent approach currently used and is considered the first-line technique for AVMs. There is an ongoing discussion about the best technical approach to embolize AVMs. AVMs associated with a dominant outflow vein (DOV) are rare. Embolization of both the DOV and the nidus is considered more effective. Herein, we report a novel technique of transvenous embolization of a DOV under negative pressure from an arterial balloon catheter in a case of a peripheral AVM. This technique allows the embolization of the DOV and the nidus retrogradely.

Double Coaxial Microcatheter Technique for Glue Embolization of Renal Arteriovenous Malformations.

PURPOSE: To demonstrate the technical benefit of the double coaxial microcatheter technique for embolization of renal arteriovenous malformations (AVMs) with n-butyl cyanoacrylate and iodized oil (glue). MATERIALS AND METHODS: Six consecutive patients (1 man and 5 women; mean age 61 years; range 44-77 years) with renal AVMs were included. Five patients had hematuria, and one had a risk of heart failure due to a large intrarenal arteriovenous shunt. All patients underwent transarterial embolization using glue and the double coaxial microcatheter technique with outer 2.6F and inner 1.9F microcatheters. After glue injection, the inner microcatheter was retracted, while the outer microcatheter was retained. We assessed the complications and clinical outcomes of this technique. RESULTS: Technical success was achieved in all patients. In 9 sessions, 34 feeding arteries were embolized with glue using the double coaxial microcatheter technique, 1 was embolized with glue using a single microcatheter, and 2 were embolized with coils. The double coaxial microcatheter technique was useful for selecting small tortuous feeding arteries, preventing glue reflux to the proximal arteries, and approaching multiple feeding arteries without complete retraction of the microcatheters. As a minor complication, glue migrated into the venous system in four patients without any sequelae. In all patients, favorable clinical outcomes, including hematuria cessation in five patients and improvement of the large intrarenal arteriovenous shunt in one patient, were obtained without deterioration of renal function. CONCLUSION: Glue embolization with the double coaxial microcatheter technique was useful for treating renal AVMs with multiple tortuous feeding arteries.

Dosimetric measurements of an n-butyl cyanoacrylate embolization material for arteriovenous malformations.

PURPOSE: The therapeutic regimen for cranial arteriovenous malformations often involves both stereotactic radiosurgery and endovascular embolization. Embolization agents may contain tantalum or other contrast agents to assist the neurointerventionalists, leading to concerns regarding the dosimetric effects of these agents. This study investigated dosimetric properties of n-butyl cyanoacrylate (n-BCA) plus lipiodol with and without tantalum powder. METHODS: The embolization agents were provided cured from the manufacturer with and without added tantalum. Attenuation measurements were made for the samples and compared to the attenuation of a solid water substitute using a 6 MV photon beam. Effective linear attenuation coefficients (ELAC) were derived from attenuation measurements made using a portal imager and derived sample thickness maps projected in an identical geometry. Probable dosimetric errors for calculations in which the embolized regions are overridden with the properties of water were calculated using the ELAC values. Interface effects were investigated using a parallel plate ion chamber placed at set distances below fixed samples. Finally, Hounsfield units (HU) were measured using a stereotactic radiosurgery CT protocol, and more appropriate HU values were derived from the ELAC results and the CT scanner's HU calibration curve. RESULTS: The ELAC was 0.0516 ± 0.0063 cm(-1) and 0.0580 ± 0.0091 cm(-1) for n-BCA without and with tantalum, respectively, compared to 0.0487 ± 0.0009 cm(-1) for the water substitute. Dose calculations with the embolized region set to be water equivalent in the treatment planning system would result in errors of -0.29% and -0.93% per cm thickness of n-BCA without and with tantalum, respectively. Interface effects compared to water were small in magnitude and limited in distance for both embolization materials. CT values at 120 kVp were 2082 and 2358 HU for n-BCA without and with tantalum, respectively; dosimetrically appropriate HU values were estimated to be 79 and 199 HU, respectively. CONCLUSIONS: The dosimetric properties of the embolization agents are very close to those of water for a 6 MV beam. Therefore, treating the entire intracranial space as uniform in composition will result in less than 1% dosimetric error for n-BCA emboli smaller than 3.4 cm without added tantalum and n-BCA emboli smaller than 1.1 cm with added tantalum. Furthermore, when effective embolization can be achieved by the neurointerventionalist using n-BCA without tantalum, the dosimetric impact of overriding material properties will be lessened. However, due to the high attenuation of embolization agents with and without added tantalum for diagnostic energies, artifacts may occur that necessitate additional imaging to accurately identify the spatial extent of the region to be treated.

[Pelvic arteriovenous malformation : a case report].

A 70-year-old male presented with intermittent macroscopic hematuria. There was no history of previous trauma or pelvic operation. At first, we were unable to clarify the origin of the hematuria, but 3D computed tomography revealed an arteriovenous malformation (AVM) consisting of multiple feeding vessels arising from the bilateral, especially right, internal iliac artery. Treatment with transcatheter arterial embolization (TAE) with a combination of lipiodol and N-butyl-2-cyanoacrylate twice was effective. He needs to be followed up carefully for recurrence of AVM.

Arteriovenous malformation arising on persistent sciatic vessels.

BACKGROUND: A persistent sciatic artery is a rare congenital anomaly, and an arteriovenous malformation arising on persistent sciatic vessels is extremely rare. METHODS: This report presents the case of a 30-year-old female with persistent sciatic vessels complicated with an arteriovenous malformation in the right buttock. It was surgically inaccessible, and a three-staged transcatheter embolization using 20% N-butyl-cyanoacrylate/80% lipiodol was performed. RESULTS: The arteriovenous malformation was shown to have been extinguished by multidetector computed tomography. CONCLUSIONS: This report presents the first case of persistent sciatic vessels complicated with an arteriovenous malformation treated by transcatheter embolization.

[Treatment of haemangiomas and vascular malformations with the neodymium-YAG laser--strategy and results in over 2000 cases]. / Neodym-YAG-Laserbehandlung von Hämangiomen und vaskulären Malformationen--unsere Behandlungsstrategie und Ergebnisse in über 2000 Fällen.

BACKGROUND: Haemangiomas represent the most common type of benign vascular tumours in childhood. A proliferative phase of unknown duration and extent is followed by an involutional period, which passes into regression in approximately 70 % of all cases. A multitude of different treatment options, such as corticosteroids, cryotherapy, laser, sclerotherapy, radiotherapy and surgical methods have been published. Due to the high rate of spontaneous regression, many authors advise not to undertake any treatment. The dilemma of this "wait and see" approach constitutes those cases in which sudden and pronounced growth is not followed by complete regression with possible severe aesthetic and functional impairment. To avoid this dilemma, a specific algorithm for the treatment of haemangiomas was instituted at our department, based essentially on early laser treatment when relevant growth is present. PATIENTS AND METHODS: More than 2000 patients with haemangiomas as well as vascular malformations have been treated at our department in the last 16 years. An algorithm for treatment of these disorders is presented. RESULTS: All therapeutic procedures, especially direct neodymium-YAG laser treatment with either contact cooling or intralesional, is described and postinterventional results are presented. CONCLUSION: Early laser treatment of fast growing haemangiomas prevents uncontrolled proliferation of these childhood tumours and, in our experience, represents a definite improvement of long-term results when compared to the "wait and see" method.

A case report of Wyburn-Mason syndrome and review of the literature.

INTRODUCTION: Wyburn-Mason syndrome is a distinct congenital neurocutaneous entity comprised of ipsilateral arteriovenous malformations (AVMs) of the midbrain, vascular abnormalities affecting the visual pathway, and facial nevi. METHODS: We report a case and review of the literature of all other reported cases of Wyburn-Mason syndrome (n = 26) in the English literature since 1973. RESULTS: In this review, we report on a 4(1/2)-year-old boy with Wyburn-Mason syndrome who presented with left retinal and orbital AVMs and a ruptured thalamic AVM. The patient did not respond to light in the left eye and demonstrated a left afferent pupillary defect. He did not have any cutaneous lesions. We also characterize other reported cases of Wyburn-Mason syndrome. CONCLUSION: The presentation of patients with Wyburn-Mason syndrome can vary greatly according to the site and the extent of vascular lesions. Intracranial AVMs occasionally hemorrhage with significant morbidity. Treatment is controversial, and patients are typically managed conservatively by observation.

Congestive heart failure: a review and case report from a chiropractic teaching clinic.

OBJECTIVE: To discuss the case of a 62-year-old woman with congestive heart failure (CHF), precipitated by a previous arteriovenous malformation, and to review the clinical presentation, pathophysiology, and treatment options for patients with CHF. CLINICAL FEATURES: The patient complained of pain, rapid weight gain, and shortness of breath. The index event for this patient was known to be an arteriovenous malformation. Biventricular cardiomegaly with pulmonary venous hypertension was evident on chest radiographs. INTERVENTION AND OUTCOME: The patient received both medical care (drug therapy) and chiropractic care (manipulation and soft tissue techniques to alleviate symptoms and discomfort). CONCLUSION: Patients with known and undiagnosed CHF may visit the chiropractic physician; thus, knowledge of comprehensive care, differential diagnosis, and continuity of care are important. Chiropractic management may be helpful in alleviating patient discomfort. Further clinical investigations may help to clarify the role of complementary and alternative care in the diagnosis and treatment of CHF.

Arteriovenous malformation of the rectum: report of a case.

We report herein the case of a 38-year-old man found to have a rectal arteriovenous malformation (AVM). The patient was admitted to our hospital for investigation of fresh anal bleeding and general malaise. Barium-enema examination showed a slightly elevated lesion in the rectum, and a selective superior rectal angiogram subsequently revealed an AVM in the peripheral region of the superior rectal artery, which was presumed to be the cause of the anal bleeding. Colonoscopic examination disclosed a submucosal tumor-like lesion in the left posterior wall of the rectum, 3cm above the anal verge. After marking the boundaries by clipping, transanal resection of the lesion was performed. Histological examination revealed an irregularly expanded arteriovenous aggregation in the submucosal layer. The patient had a favorable postoperative course, and no residual AVM was seen on a postoperative selective inferior mesenteric arteriogram. There have been no signs of recurrence in the 2 years since his operation.

Arteriovenous malformations of the dental arcades. The place of endovascular therapy: results in 12 cases are presented.

Twelve arteriovenous malformations of the dental arcades (AVMDAs) (seven mandibular and five maxillary) were seen in our institution between 1977 and 1997. All these lesions consisted of true arteriovenous shunts (of either nidus or fistulous type) involving the bone, with or without soft tissue extension. Haemorrhage was present in eight patients (67%); either torrential, necessitating emergency embolization, or recurrent and progressive. Teeth instability was detected in all patients and was the origin of the bleeding. All lesions were embolized. Lesions in nine patients were embolized with Polyvinyl Alcohol Particles (PVA): this helped to stabilize the situation but could not avoid recurrences in all patients, necessitating complementary embolizations and or surgery. The use of acrylic glue (N-Butyl-Cyano-Acrylate [NBCA] Histoacryl) as the embolic agent has changed the results obtained tremendously. Eight patients have been treated with NBCA (five as complementary therapy to PVA during later sessions and three at the first attempt); injection either via the transarterial route or direct transcutaneous puncture (four patients) achieved a cure in four of these lesions (34%) with stability at long-term follow-up of all the other AVMs. Embolization with glue represents the therapy of choice in these sometimes life-threatening lesions, achieving a cure if directed towards the osseous venous lakes. Surgery, often leading to facial mutilation and necessitating massive reconstruction should be avoided nowadays, at least as the initial therapy.

Surgery for deeply seated arteriovenous malformation: with special reference to thalamic and striatal arteriovenous malformation.

Surgery for deeply seated arteriovenous malformation (AVM) is controversial because stereotactic irradiation is applicable to the lesion. We have, however, experienced 30 deeply seated AVMs treated by direct surgery and/or endovascular treatment. The present study shows profiles of those patients and results of surgery. They include AVM in the thalamus in 12 cases, striatum in four cases, paraventricular area in five cases, medial temporal lobe in three cases, intraventricular area in three cases, and other regions in three cases. They were treated by surgery alone in 23 cases, embolization followed by surgery in four cases, and embolization alone in three cases. AVM in the mediodorsal thalamus and fornix (5 cases) was best treated by transcallosal approach. Venous aneurysm was commonly found in the AVM of this region and was a good navigator to the AVM. Pulvinar AVM was accessible through posterior interhemispheric approach (2 cases). None of these cases had additional neurological deficits. Cadaver dissection was useful for acquisition of surgical approach. Striatal AVM was approached through hematoma cavity with minimal manipulation to the surrounding structures, yet two of four cases showed progression of their weakness. The present study indicates that thalamic AVM can be approached surgically with careful selection of the approach. On the other hand, striatal AVM is not a good candidate for direct surgery and better treated by stereotactic irradiation.

The use of total circulatory arrest in the surgery of giant hemangioma and Klippel-Trenaunay syndrome in neonates.

Two neonates required deep hypothermia and circulatory arrest to provide a central control of blood loss for the resection of giant cavernous hemangiomas. Both infants were placed on cardiopulmonary bypass, cooled to 16 degrees, and exsanguinated before resection of these peripheral lesions. The surgery was done as a lifesaving measure in both instances because both infants were suffering from high-output cardiac failure. In both cases, the small total blood volumes were critical in excision of these hypervascular tumors. Use of the techniques described allowed for the surgery to be performed in a bloodless field over a short period (one hour), thus preventing massive blood loss. Both patients are living with no neurologic or developmental deficits more than five years after the operation.

Ventricular obstruction secondary to vascular malformations.

Enlarged veins in two vascular malformations blocked the cerebrospinal fluid outflow pathways, causing hydrocephalus. Both patients presented not with the usual clinical picture (hemorrhage, seizure, etc.), but with signs of increased intracranial pressure. Computed tomography and angiography were necessary to understand the pathophysiology. An arteriovenous malformation was responsible for the first patient's headache, and a venous varix was the causative lesion in the second patient. Hydrocephalus caused by a venous varix has not been reported before.

[Selective spinal arteriography. Its bearing on diagnosis and therapy of spinal processes, particularly arteriovenous malformations (author's transl)]. / Die selektive Spinalarteriographie und ihre Bedeutung für Diagnostik und Therapie spinaler Prozesse, insbesondere arteriovenöser Missbildungen.

Selective spinal arteriogrpahy is a neuroradiologic technique not yet generally known. For the experienced examiner it is not more dangerous than cerebral catheter-angiography. It is most important for the diagnosis of spinal arteriovenous malformations. Here it is an essential examination even when myelography has already shown clear findings. In certain cases in can be used for therapy (artificial embolisation). In other spinal processes further experience will be needed.