Transcranial Doppler of a paradoxical brain embolism associated with a pulmonary arteriovenous fistula

We herein report the case of a patient who had paradoxical brain embolism owing to a pulmonary arteriovenous fistula (PAVF) who was diagnosed as having a right-to-left shunt by transcranial Doppler (TCD) with saline contrast medium. TCD with saline contrast medium failed to detect any high-intensity transient signals immediately after catheter embolization of the PAVF. Thus, TCD with saline contrast medium was useful for identifying the presence of a right-to-left shunt and for confirming that the shunt had been obliterated after endovascular treatment.     

Transpleural ultrasound diagnosis of a pulmonary arteriovenous malformation

Pulmonary arteriovenous malformations (PAVMs) are rare. We discuss a case of an 81-year-old female who attended hospital with a haemothorax. Ultrasound not only demonstrated an echogenic effusion in the right pleural space, but also identified an associated tubular structure. Doppler was applied to this structure, which exhibited pulsatile flow. This raised the possibility of a PAVM, which was subsequently confirmed on CT and angiography. Although, PAVM is a rare cause of haemothorax, the diagnosis should still be considered and transpleural ultrasound can detect these malformations non-invasively by the bedside.     

Scintigraphic evaluation of small pulmonary right-to-left shunt and therapeutic effect in pulmonary arteriovenous malformation

PURPOSE: Right-to-left shunts of pulmonary arteriovenous malformation (PAVM) can be detected and measured by pulmonary perfusion scans using Tc-99m MAA. In PAVM with a relatively small right-to-left shunt, however, measurement of the shunt ratio may not be reliable. This study re-evaluated pulmonary perfusion scans for a small right-to-left shunt of PAVM. METHODS: Tc-99m MAA lung scans were performed in five patients with proved PAVM before and after percutaneous transcatheter embolization. The right-to-left shunt ratio was calculated and extrapulmonary uptake was assessed on total-body images. RESULTS: Lung perfusion scans obtained before embolization revealed brain uptake in four patients, and the shunt ratio ranged from 4.4% to 22.9%. In two patients with a small single PAVM, the shunt ratio was less than 15% before treatment and did not change significantly after successful embolotherapy. The brain uptake, which had been clearly visible before therapy, disappeared after embolization. Renal uptake was seen on pre- and post-therapy scans. CONCLUSIONS: Changes in brain activity visible on Tc-99m MAA scans might be a more reliable sign than a decreased shunt ratio or a change in renal uptake when evaluating embolization therapy in patients with PAVM who have a small right-to-left shunt.     

肺动静脉畸形的影像学诊断

<正> 肺动静脉畸形(pulmonary arteriovenous malformation,PAVM)在临床较为罕见,但其可引起严重的临床症状,如脑梗死、致命性大咯血等,故及时、准确地诊断尤为重要。本文回顾性分析经手术及肺动脉造影确诊的PAVM 7例,旨在提高其诊断水平并评价各种影像学检查方法的优势。1 资料与方法1.1 一般资料搜集自2005～2010年经手术及肺动脉造影确诊的PAVM患者7例,其中男3例,女4例;年龄13～56岁。7例均否认有家族史。     

Cerebral embolism—First manifestation of pulmonary arteriovenous malformation in patient with hereditary hemorrhagic telangiectasia

Four of five patients with asymptomatic small or moderate-size pulmonary arteriovenous malformation (PAVM) presented with a paradoxical embolus and stroke. In these patients chest radiographic findings were subtle and arterial hypoxemia provided the real clue to diagnosis. Computed tomography (CT) and cerebral arteriography confirmed embolic occlusion in four of five patients. Careful family screening including posteroanterior (PA) and lateral chest radiographs and arterial oxygen determinations in siting or standing positions are recommended for early detection of asymptomatic patients with PAVM. Early therapeutic intervention (with balloon embolotherapy) is recommended to avoid paradoxical embolization.     

Contrast-enhanced MRA in pre-embolization assessment of a pulmonary arteriovenous malformation

We describe a case of a single pulmonary vascular malformation studied with a new contrast-enhanced three-dimensional MRA technique. Images provided the interventional radiologist with a pre-embolization road map from which information regarding the number and size of feeding and draining vessels was obtained accurately and noninvasively.     

肺动静脉畸形经导管封堵术的疗效评价

目的对肺动静脉畸形(AVM)经导管封堵术进行疗效评估。方法16例肺AVM患者接受经导管弹簧圈栓塞术治疗,其中5例同时辅以经导管可脱式球囊栓塞术或国产自制双伞形血管封堵器置入术治疗。对所有患者的家族史,术前和术后的临床表现,动脉血气分析以及其影像学表现等作了回顾性分析。16例患者术后平均随访(21±1)个月,根据其胸部CTA检查结果及动脉血气分析结果评估疗效,并对其术前和术后血氧饱和度(SaO2)、动脉血氧分压(PaO2)进行统计学分析。结果16例首次经导管封堵治疗技术成功率75%(12/16),再次经导管封堵治疗技术成功率100%。16例患者术前SaO2平均值为(76±5)%,PaO2平均值为(46±3)mmHg;术后SaO2平均值上升为(94±5)%,PaO2平均值上升为(62±3)mmHg,与术前相比差异均有统计学意义(P<0.01和P<0.05)。术后随访,所有患者无症状复发,胸部CTA检查未发现明显血管再通。结论采用经导管弹簧圈栓塞术,或同时辅以经导管可脱式球囊栓塞术或国产自制双伞形血管封堵器置入术等治疗肺AVM,可获得满意的临床疗效。     

Renal arteriovenous malformation presenting as a mass lesion.

Arteriovenous malformations of the kidney are definitively diagnosed by selective arteriography (1). The following case is unique in that it presented as an avascular mass and the lesion itself could not be demonstrated angiographically.     

Pulmonary scintigraphy in a patient with multiple pulmonary arteriovenous malformations and pulmonary embolism

The scintigraphic findings in a patient with multiple pulmonary arteriovenous malformations (AVMs) complicated by superimposed pulmonary embolism are reported. Although pulmonary AVMs may cause small subsegmental scintigraphic abnormalities, the demonstration of perfusion defects which are segmental or larger should strongly suggest the presence of superimposed pulmonary embolism in a patient with multiple pulmonary AVMs.     

Three-dimensional gadolinium-enhanced magnetic resonance angiography of pulmonary arteriovenous malformation

Pulmonary arteriovenous malformations (AVMs) are rare vascular malformations of the lung. Although most patients are asymptomatic, AVMs can bleed and result in haemoptysis and haemothorax. We describes a case of pulmonary AVMs in a patient with Osler-Weber-Rendu syndrome with 3-D contrast-enhanced MR angiography. Magnetic resonance angiography provided accurately and non-invasively the number and size of the feeding arteries and draining veins.     

Cardiac metastasis: a cause of recurrent pulmonary emboli

Intracavitary cardiac metastasis is rare. Apart from causing intracardiac obstruction, this type of metastasis can present as pulmonary emboli. It is important to suspect this diagnosis in an oncology patient with recurrent pulmonary emboli, particularly in the setting of a negative venous Doppler ultrasound of the lower limbs and pelvis. Early recognition may help in improving the prognosis. We present a case of intracavitary cardiac metastasis arising from a squamous carcinoma of the cervix, in a patient with recurrent pulmonary tumour emboli.     

Klippel-Trenaunay-Weber syndrome with recurrent pulmonary embolism.

A man with Klippel-Trenaunay-Weber syndrome had worsening pulmonary hypertension secondary to recurrent multiple pulmonary embolism despite anticoagulation. Pulmonary thromboendarterectomy was done. However, the patient expired 10 days after surgery due to another bout of pulmonary embolism from his right arm or right chest wall.     

Renal cirsoid arteriovenous malformation masquerading as neoplasia

A woman with renal colic and microscopic hematuria had filling defects in the left renal collecting system detected on excretory urography. A nephrectomy, performed because of suspected malignancy, might have been averted by renal angiography.     

Transcatheter occlusion of a large pulmonary arteriovenous malformation with use of a Cardioseal device

Large pulmonary arteriovenous malformations (PAVMs) carry a significant risk of neurologic complications and present technical difficulties in transcatheter treatment with use of coils or detachable balloons. A 26-year-old man with a giant PAVM, who had undergone unsuccessful attempted closure with use of a Gianturco-Grifka occlusion device in the past, underwent successful transcatheter embolization with two Cardioseal double umbrella devices designed for occlusion of intracardiac communications. The procedure was technically easy, had no complications, and provided sustained improvement in arterial saturation and exercise tolerance during follow-up. Transcatheter double umbrella device occlusion of large arteriovenous malformations is feasible and should be considered, especially for very large fistulas.