Capillary malformation-arteriovenous malformation, a new clinical and genetic disorder caused by RASA1 mutations.
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Capillary malformation (CM), or "port-wine stain," is a common cutaneous vascular anomaly that initially appears as a red macular stain that darkens over years. CM also occurs in several combined vascular anomalies that exhibit hypertrophy, such as Sturge-Weber syndrome, Klippel-Trenaunay syndrome, and Parkes Weber syndrome. Occasional familial segregation of CM suggests that there is genetic susceptibility, underscored by the identification of a large locus, CMC1, on chromosome 5q. We used genetic fine mapping with polymorphic markers to reduce the size of the CMC1 locus. A positional candidate gene, RASA1, encoding p120-RasGAP, was screened for mutations in 17 families. Heterozygous inactivating RASA1 mutations were detected in six families manifesting atypical CMs that were multiple, small, round to oval in shape, and pinkish red in color. In addition to CM, either arteriovenous malformation, arteriovenous fistula, or Parkes Weber syndrome was documented in all the families with a mutation. We named this newly identified association caused by RASA1 mutations "CM-AVM," for capillary malformation-arteriovenous malformation. The phenotypic variability can be explained by the involvement of p120-RasGAP in signaling for various growth factor receptors that control proliferation, migration, and survival of several cell types, including vascular endothelial cells. (+info)
Quantification of right to left shunt at rest and during exercise in patients with pulmonary arteriovenous malformations.
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BACKGROUND: Current treatment of patients with pulmonary arteriovenous malformations requires serial embolisations by means of steel coils or balloons. Measurement of right to left shunt is the most specific index of response to treatment. A new method of measuring shunt has been developed that is less invasive than traditional methods. METHODS: Right to left pulmonary shunt (expressed as percentage of cardiac output) was measured at rest in 19 patients with pulmonary arteriovenous malformations and six normal subjects by using intravenously injected albumin microspheres labelled with technetium-99m. The technique was compared with a simultaneous shunt measurement in subjects breathing 100% oxygen while they rested. The microsphere technique was adapted to measure the right to left shunt during exercise in 12 patients and five normal subjects with a new method of quantification. RESULTS: The mean (SD) shunt at rest as measured by the microsphere method was 23.2% (15.6%) in the patients and 2.7% (1.2%) in the normal subjects. When these values were compared with those of the 100% oxygen method the difference in mean values was 1% and the limits of agreement between the two methods -32% to +45%. The microsphere method is less invasive (arterial blood gas sampling is not required), quicker, and more comfortable for patients than the 100% oxygen method. In five of the normal subjects the mean (SD) 99mTc microsphere shunt increased from 2.9% (1.3%) at rest to 5.1% (2.9%) during exercise. In the 12 patients studied during exercise the shunt increased from 33.7% (12.7%) at rest to 41.7% (13.3%) during exercise in eight but decreased from 22.6% (2.4%) at rest to 17.6% (2.2%) during exercise in four. Arterial desaturation during exercise correlated with change in the size of the right to left shunt during exercise (r = +0.80). CONCLUSIONS: The microsphere method allows measurement of right to left shunt at rest and during exercise. Serial measurements at rest provide a simple, safe assessment of the physiological response to embolisation in patients with pulmonary arteriovenous malformations. (+info)
Serum ethanol levels after alcohol sclerotherapy of arteriovenous malformations.
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We analyzed the effects of several factors on the serum ethanol levels after alcohol sclerotherapy in the arteriovenous malformations (AVMs) retrospectively. Blood ethanol level, amounts of given alcohol, location of lesions, methods of flow control, and Doppler resistive index (RI) were analyzed. The results of linear regression analysis showed that the amount of alcohol administered was the predictor of serum ethanol level (r2=0.75, p<0.001). The average amount of injected alcohol was 0.89 mL/kg in the patients with the serum levels above the legal intoxication level (>80 mg/dL). Location of the lesions was not related with the serum ethanol level (p=0.643), and other variables such as forms of flow control and RI were not related to the serum ethanol level after controlling for injected amounts of alcohol (analysis of covariance). It is recommended to keep an eye on the possibility of intoxication when using the amounts of alcohol exceeding 0.89 mL/kg in the sclerotherapy of AVMs. (+info)
Vascular malformations arising from the wall of the external jugular vein are rare. This case series discusses the sonographic and MR imaging appearances of four such cases and reviews the literature. The diagnosis should be suggested preoperatively particularly because of the close relationship such malformations to the external jugular vein, as this helps surgeons to plan the operative procedure. The imaging appearances are similar to those of other vascular malformations elsewhere in the head and neck. (+info)
Management of arteriovenous malformations: a multidisciplinary approach.
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BACKGROUND: Management of arteriovenous malformations (AVMs) remains challenging because of their unpredictable behavior and high recurrence rate. A multidisciplinary approach based on a new classification scheme and improved diagnostic techniques may improve their management. The purpose of this study was to review our experience with combined embolotherapy, sclerotherapy (embolo/sclerotherapy), and surgical procedures to manage AVMs. METHODS: A total of 797 patients with congenital vascular malformations (January 1995 through December 2001) was investigated with noninvasive studies. Once an AVM was diagnosed, all underwent angiographic confirmation as a roadmap for treatment. Embolo/sclerotherapy and surgical procedures were instituted by the multidisciplinary team with periodic follow-up per protocol. Seventy-six patients with AVMs were reviewed retrospectively to assess the diagnosis and management by a multidisciplinary approach. RESULTS: Seventy-six (9.5% of all CVM) patients had AVMs, mostly infiltrating, extratruncular form (61/76). Embolo/sclerotherapy with various combinations of absolute ethanol, N-butyl cyanoacrylate (NBCA), contour particles, and coils were used in 48 patients. Sixteen patients with surgically accessible localized lesions completed preoperative embolism and sclerotherapy through 24 sessions, with subsequent surgical excision with minimal morbidity. Interim results were excellent, with no evidence of recurrence in all 16 patients with a mean follow-up of 24 months. Thirty-two patients with surgically inaccessible lesions (infiltrating) were treated with embolism and sclerotherapy alone. There were nine failures in a total of 171 sessions. Interim results with a mean of 19 months' follow-up of embolism and sclerotherapy alone were excellent in the majority (25/32) and good to fair among the rest (7/32). However, 31 complications, mostly minor (27/31), occurred in 30 sessions. Four major complications occurred, including facial nerve palsy, pulmonary embolism, deep vein thrombosis, and massive necrosis of an ear cartilage. CONCLUSIONS: Diagnosis and management of AVMs by a multidisciplinary approach that integrates surgical therapy with embolism and sclerotherapy appears to improve the results and management with limited morbidity and no recurrence during early follow-up. (+info)
Osseous regeneration after embolization of mandibular arteriovenous malformation.
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A mandibular arteriovenous malformation (AVM) is rare, and unawareness of this condition can lead to catastrophic complications. Embolization is an effective means to treat these lesions. The osseous changes and long-term outcomes among the pediatric patients after embolization treatment remain unclear. We present a 6-year-old patient with mandibular arteriovenous malformation who had sustained hemorrhagic shock after a tooth extraction. She was referred to us after stabilization of the hemodynamic condition. The patient received transarterial and direct intralesional embolization. Local infection occurred 3 months after embolization, but was well controlled. Serial computed tomography and panoramic radiographs were performed during follow-up examinations. The imaging studies showed gradual obliteration of the vascular space followed by normal bone regeneration and remodeling. The processes were complete during a period of 2 years. There was no recurrence of the vascular malformation and no abnormal growth of the right side of the mandible after 4 years and 4 months of observation. (+info)
A small pulmonary arteriovenous malformation as a cause of recurrent brain embolism.
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We report a case of recurrent paradoxical brain embolism mediated through a small pulmonary arteriovenous malformation (PAVM) with a 1.8-mm-diameter feeding artery. In this case, the further recurrent stroke was prevented successfully by PAVM embolization. Although embolization therapy is currently recommended only for PAVMs with feeding arteries greater than 3 mm in diameter, the therapy may be needed also in the smaller PAVMs. (+info)
Endovascular management of a mandibular arteriovenous malformation in a patient with severe hemophilia a.
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The unusual case of a mandibular arteriovenous malformation in a patient with severe hemophilia A and hepatitis C is reported. Supplementary substitution of various coagulation factors allowed direct puncture and intralesional injection of a liquid adhesive, resulting in complete anatomic and clinical cure without peri- or postoperative bleeding. Replacement therapy providing normal levels of relevant coagulation factors enables endovascular treatment in a safe and effective manner in hemophiliac patients. (+info)