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We performed robot-assisted laparoscopic radical prostatectomy (RARP) without transcatheter arterial embolization (TAE) for a 72-year-old male patient with prostate cancer and pelvic arteriovenous malformation (AVM). Though lymphatic dissection was made contralateral to the AVM, the operation time (robotic: 2h 40 min, and total: 3h 2 min) was not long. Moreover, the blood loss amount of 250 ml was less than those in the past reports of preoperative TAE. Robotic surgery, a dissection of an abnormal arterial branch from the internal iliac artery before the division of the bladder neck, bunching of the deep dorsal vein complex, and resection of the vascular pedicle connecting with AVM in the final step of prostatectomy, contributed to the safe operation. Moreover, the surgical margin was negative in the pathological report,and the prostate specific-antigen was 0.006 ng/ml 3months following the operation. In addition, CT revealed the same size of AVM and no postoperative complication. It has been demonstrated that in the absence of TAE for pelvic AVM, RARP for prostate cancer is safe and effectively controls cancer.

This study presents the case of a 52-year-old male suffering from extensive melena. A detailed examination using lower gastrointestinal endoscopy revealed a polyp at the lower rectum; subsequently, endoscopic mucosal resection(EMR)was performed. No other lesion for the melena was observed. Histopathologic findings of the EMR confirmed adenocarcinoma in adenoma, indicating the need for additional surgery. Preoperative contrast-enhanced CT revealed an arteriovenous malformation( AVM)of about 5 cm in the rectal wall at the anal side of the lower rectal cancer. Extensive melena was inferred to be caused by AVM; hence, we performed laparoscopic low anterior resection combined with accessible excision of the AVM and blocked the superior rectal artery, acting as an inflow vessel. Postoperative contrast-enhanced CT confirmed the disappearance of AVM. Thus, we experienced a case in which the block of the inflow vessel, according to the treatment theory of embolism therapy without complete resection of the AVM, enabled the treatment of AVM. Therefore, this case could become a reference for the treatment of lower rectal AVM cases in the future.

Spinal arteriovenous malformation(AVM)is a rare disease in which blood is received from the spinal feeding arteries. Owing to its rarity, there is limited experience regarding its diagnosis and treatment. In addition, the various classifications that have been proposed historically make it more difficult for the young neurosurgeons to understand this disease. Because delayed initial diagnosis leads to irreversible damage of the spinal cord, neurosurgeons should always consider spinal AVM as one of the differential diagnoses. In order to understand the pathological condition of spinal AVM, it is important to learn basic classification. Spinal AVM is classified as intradural, dural, and epidural. Spinal digital subtraction angiography(DSA)is the gold-standard for the diagnosis of spinal AVM and is indispensable toolfor treatment planning. The purpose of this paper is to summarize a basic classification and diagnosis of spinal AVM.

In this paper, we outlined the diagnostic and treatment strategies for spinal arteriovenous malformations, focusing on dural and perimedullary arteriovenous fistula(AVF). In many patients with spinal arteriovenous malformations, the symptoms are non-specific. Therefore, we consider it is critical to detect the signal flow voids in the enlarged spinal veins using MRI. An accurate understanding of the vascular structures is indispensable for deciding appropriate treatment strategies. Hence, performing an angiography is essential. Regarding treatment, whether to select surgical or endovascular treatment for AVF depends largely on the institution's protocols. However, the treatment should always be based on an accurate diagnosis.

A 23-year-old woman was referred to our hospital with progressive headache and back pain. Cerebrospinal fluid(CSF)analysis revealed hypoglycorrhachia and pleocytosis. However, imaging studies did not reveal evidence of subarachnoid hemorrhage(SAH), and she was diagnosed with bacterial meningitis. CSF analysis repeated after antibiotic treatment continued to show evidence of blood. Spinal SAH was suspected, and MRI revealed a spinal arteriovenous malformation(AVM). Spinal digital subtraction angiography revealed the nidus and a feeder aneurysm, which was implicated as the source of bleeding;therefore, she was diagnosed with spinal SAH secondary to spinal intramedullary AVM(SAVM). She underwent endovascular treatment for the spinal aneurysm and was discharged without worsening neurological symptoms. SAVMs presenting without neurological findings and/or evidence of bleeding on plain CT images are diagnostically challenging;notably, findings on CSF analysis could mimic those observed in cases of infectious disease. We should cite vascular diseases such as SAVM.

A 67-year-old woman was referred to our hospital for precise examination and treatment as an abdominal computed tomographic (CT) scan showed a retroperitoneal tumor located below the hilus of the right kidney. The enhanced CT and magnetic resonance imaging (MRI) revealed contrast enhancement in both early and late phase, which confirmed that the tumor showed abundant blood perfusion and adhered to the duodenum. We performed open surgery in order to remove the tumor and make a precise diagnosis. The tumor was excised en bloc with a part of the gonadal vein because the right gonadal vein was adjacent to the tumor in the craniocaudal direction. The pathological diagnosis was arteriovenous malformation. Arteriovenous malformation located in the retroperitoneum is very rare.

We report a 4-year old boy with a large arteriovenous malformation (AVM) exhibiting attention-deficit hyperactivity disorder (AD/HD). He presented with hyperkinesis at the age of 3 years and jacksonian seizure at 3 years 11 months, when he was diagnosed as AVM by cranial computed tomography. Magnetic resonance imaging revealed an AVM of 6 cm in diameter in the left frontal lobe. After 1 year, the AVM developed a varix, and both were surgically removed. We speculate that the prefrontal area was affected by direct compression from AVM and chronic ischemia due to steal phenomenon. Although AD/HD is rarely caused by parenchymal lesions, such as AVM, physicians should carefully investigate causative lesions.

A 58-year-old man with a complaint of sever epigastralgia was referred to our hospital. At a previous hospital, he had been initially diagnosis as having ruputured aneurysm of the head of the pancreas. A final diagnosis of arteriovenous malformation of the head of the pancreas by MDCT and abdominal angiogram, and underwent pancreatoduodenectomy. Major feeding arteries were the gastroduodenal artery and inferior pancreatoduodenal artery, and the major drainage vein was the gastrocolic trunk. This case was also diagnosed as Osler-Weber-Rendu disease because of the presense of three of the four criteria for this disease: habitual epistaxis, oral telangiectasia, and angiodysplastic lesion in the internal organ. This is the first reported case of arteriovenous malformation with Osler-Weber-Rendu disease in Japan.

A 63-year-old female with Rendu-Osler-Weber disease had general fatigue and right hemiparesis. A computed tomography (CT) scan of her head demonstrated an enhancing cystic mass in the left frontal lobe, and it was diagnosed as a brain abscess and then drainaged. Thereafter, a pulmonary arteriovenous malformation (PAVM) identified in the left lingular segment by chest CT scan and the PAVM was resected by partial resection of the lung.

A 75-year-old woman was scheduled for the right partial pulmonary resection, because of severe hypoxemia caused by monofocal arteriovenous malformation. Before the operation, we obstructed successfully the shunt flow of arteriovenous malformation by using a balloon of pulmonary artery catheter. The hypoxemia was improved remarkably and we could control anesthesia safely.

A 19-year-old woman admitted for hemoptysis had remarkable hypoxemia. Pulmonary artery angiography indicated diffuse telangiecatic arteriovenous malformations in the left upper lobe and part of the left lower lobe. The shunt ratio was calculated as 48.7%. Many patients of this diffuse telangiecatic type have a poor outcome, because of its seriousness, difficulty to treat and high risk of complications. In this patient, it was judged that embolization was impossible due to the form of the lesions. We performed resection of left upper lobe and a part of left lower lobe. After the operation, hypoxemia improved remarkably, as well as the shunt ratio (28.8%). No clinical sign of recurrence has been observed two years after the operation.

We experienced a case in which hyperkalemia was induced by mannitol administration. The medication with mannitol was given to a 15-year-old male patient who underwent a removal operation for arteriovenous malformation under general anesthesia. Following the mannitol infusion, his arterial blood gas and electrolyte analysis revealed severe metabolic acidosis and an increase in serum potassium. Furthermore, a change in his electrocardiogram was observed. The hyperkalemia was quickly normalized by medication with calcium gluconate and sodium bicarbonate. We stopped the removal operation with the aim of giving priority to the patient's safety. It is speculated that the hyperkalemia was caused by the administration of mannitol. Checks of electrolyte levels, arterial blood gas analysis and electrocardiogram monitoring should therefore be carried out when using mannitol, especially in an emergency situation such as intracranial hemorrhage.

We herein report an initial experience of thoracoscopic surgery for a solitary arterior-venous malformation (PAVM) with the AESOP 3000 HR voice-controlled robot to hold a thoracoscope. A 52-year-old woman was hospitalized due to a transient loss of consciousness. A brain magnetic resonance image and electroencephalogram (EEG) were normal. A chest computed tomogram indicated a suspicion of PAVM. The definite diagnosis of the PAVM was made by the 3-dimensional computed tomogram and pulmonary angiography. Thoracoscopic operation with the voice-controlled robot (AESOP 3000 HR) was conducted. The operating staffs were able to assemble the AESOP 3000 HR robotic system safely and quickly without difficulty. The robot functioned without problems throughout the procedure. No complications or events related or unrelated to the maneuvers of the robot during the operation were noted. The procedure of the pulmonary resection with the voice-controlled robot was successfully preformed by a single surgeon. The operating time was 110 minutes, and the volume of the intraoperative bleeding was 10 g. The postoperative course was uneventful. The use of the AESOP 3000 HR robot may be more convenient and friendly in thoracoscopic procedure.

A rare operative case of thrombosed arteriovenous malformation (AVM) in the brain stem was reported focusing on its differential diagnosis from cavernous malformation. A 49-year-old woman had developed pontine hemorrhage twice during the last two years. She was diagnosed by neurologists as having cavernous malformation in the brain stem, and then referred to our institute. Neurological examinations showed left hemi motor and sensory disturbance, right abducent palsy and right auditory disturbance. A computed tomography (CT) scan revealed a high density mass in the brain stem considered as a hematoma with slight enhancement. Magnetic resonance imaging (MRI) revealed a high intensity mass in T1 and T2 weighted MRI with marginal hemosiderin rim, but neither flow void sign nor enhancement effect was detected. Angiography depicted no abnormal vasculature in the posterior fossa. The patient underwent surgical resection of the lesion 43 days after a second hemorrhage. Midline sub-occipital craniotomy and the infrafacial route were chosen. Surgery was troubled by arterial bleeding, and pathological examination revealed a thrombosed AVM. She newly developed right facial palsy, right abducent palsy and disturbance of right conjugate gaze, but she is recovering step by step. Although the radiological feature of thrombosed AVM in the brain stem is similar to that of cavernous malformation, the operative procedure for thrombosed AVM is very difficult due to aggressive arterial bleeding that easily leads to surgical injury in the small surgical corridor in the brain stem. We reported a rare case that was pathologically well identified as thrombosed AVM in the brain stem focusing on its differential diagnosis and surgical treatment.

We have recently encountered a case of high cervical arteriovenous malformation which caused subarachnoid hemorrhage. A 54-year-old male was admitted to our hospital due to sudden onset of severe headache. Neurological examination revealed right sixth nerve palsy which suggested elevated intracranial pressure. A CT scan showed subarachnoid hemorrhage predominantly in the posterior fossa, massively ventral to the brain stem, with reflux into the fourth ventricle. No abnormal vascular lesions were found in the first cerebral angiography which included four vessels and bilateral thyrocervical trunks. Ten days later, the second cerebral angiography demonstrated an arteriovenous shunt via the right vertebral artery draining into the epidural space of the upper cervical region. A suboccipital craniotomy and laminectomy of the atlas were performed. An abnormally dilated vein along the right C1 nerve ventral root which drained into the tortuous dilated coronary venous plexus on the ventral side of the spinal cord was found. We made a diagnosis of dural arteriovenous malformation fed by the C1/C2 radicular artery via the right vertebral artery and draining into the radiculomedullary vein and the epidural venous plexus. The interruption of both intra- and extradural draining veins was carried out. The postoperative course was uneventful.

Most spinal dural arteriovenous malformations (AVMs) affect the thoracic and lumbar regions. The clinical features of dural AVMs are, usually, gradually progressing myelopathy, while hemorrhage is a rare occurrence. We have recently encountered two cases of cranio-cervical junction dural AVM which caused subarachnoid hemorrhage. Both patients, a 61-year-old and a 37-year-old man were admitted to our hospital due to sudden onset of severe headache. Left vertebral angiography demonstrated a dural AVM at the cranio-cervical junction. A left suboccipital craniotomy and left hemilaminectomy of the atlas were performed. Dural opening disclosed tortuous dilated abnormal vessels. The dural AVM was fed by multiple small dural branches of the left vertebral artery and drained into an intracranial pial vein. The dura where the left vertebral artery penetrated was coagulated and divided from the left vertebral artery. Postoperative courses of these patients were uneventful. The pathophysiology and surgical treatment of dural AVMs in the cranio-cervical junction are discussed.

We report a 15-year-old boy with chronic myelogenous leukemia who received unrelated bone marrow transplantation (uBMT) after surgical resection of cerebral arteriovenous malformation (AVM). The incidence of cerebral hemorrhage caused by rupture of cerebral ABM in cases of BMT is uncertain. However, since the risk of rupture of AVM was supposed to increase due to both severe thrombocytopenia after intensive chemotherapy and increased intracranical pressure because of total body irradiation (TBI) as preconditioning therapy for BMT, we have first carried out surgical resection of the cerebral AVM, and subsequently performed uBMT. This resulted in a favorable clinical course without serious complications.

Two cases of dural arteriovenous malformation (DAVM) of the posterior fossa were presented and a histopathological examination was described. After embolization of the feeding arteries, DAVMs of the posterior fossa were removed with the adjacent sinus. Serial sections of the surgical specimens showed an abnormal mass with dilated, tortuous vessels of varying diameters in the sinus wall, and partially hyalinized connective tissue around the vessels. The elastic lamina of the sinus wall was interrupted and a mass of abnormal vessels developed into the subintimal layer of the sinus. Fistulas, about 200 microns in diameter, were formed between arterialized dural veins and dural arteries which had obvious internal elastic lamina. An opening of the fistula of the abnormal vessel, 25 microns in diameter, to the sinus lumen was also seen. No stage of organized thrombus could be seen in the sinus lumen. These findings strongly suggested that physiologically existing arteriovenous fistulas within the dura mater, which have been reported by Kerber et al, had developed due to many factors which increase intracranial pressure. They protruded into the sinus lumen in such a way that it could cause stenosis or obstruction of the sinus. In conclusion it can be said that an obstructive lesion of dural sinus is considered of itself to be DAVM in most cases and sinus thrombosis is the result of the DAVM.

A 32-year-old right-handed female tour guide developed a transient prosopagnosia after the total removal of an arteriovenous malformation in the right occipital lobe. Neurological examination revealed only a left homonymous hemianopsia. The ablation on the right side involved total occipital lobe, the posterior region of the parahippocampal gyrus, and a part of the precuneus and angular gyrus. Neuropsychologically she was alert and oriented in time and place. No aphasia or apraxia was observed. Visual recognition of objects, colors and letters was normal. She could match faces and insects easily, despite a close resemblance among them. Her prosopagnosia resolved in one month, while her impairment in topographical orientation and nonverbal memory continued more than eight months. These findings exclude the possibility that her prosopagnosia was derived from visual agnosia, poor discrimination of details, or nonverbal memory deficit. Excluding cases with malignant brain tumor which may affect more diffuse area of the brain, there was only one reported case who developed persistent prosopagnosia after the right occipital lobectomy. Given the rarity of prosopagnosics with only right-sided lesions, it seems that in most of humans posterior parts of both hemispheres participate in the identification of faces.

The authors report a rare case of acute cervical epidural hematoma caused by the hemorrhage from extradural arterio-venous malformation. The patient was a 74-year-old Japanese man with a past history of total gastrectomy after being diagnosed as having gastric cancer 12 years before. Six hours prior to admission, the patient had experienced a sudden episode of severe nuchal pain radiating to both scapular areas, followed by rapid development of left-side Brown-Sequard Syndrome below the C4 cord level, and urinary incontinence. Plain cervical X-ray films did not show any destructive lesion suggesting a metastatic tumor. T1 and T2 weighted images of MRI demonstrated a high intensity mass lesion, suggesting an acute epidural hematoma, extending from C3 to C6 and compressing severely the left side spinal cord posteriorly. Twelve hours after the onset of symptoms, emergency laminectomy from C3 to C6 was performed and a fresh epidural clot with small vascular tissue was totally removed. Histological examination of the small vascular tissue in the hematoma revealed arterio-venous malformation. The postoperative recovery of the patient was dramatic. He regained full muscle strength and there was complete disappearance of sensory deficits 2 weeks after the operation. Although acute spinal epidural hematoma caused by extradural arterio-venous malformation is a rare clinical entity, MRI is the most helpful diagnostic tool for this condition. It should be stressed that accurate neuroradiological diagnosis and prompt surgical decompression of the spinal cord are essential to obtain an excellent surgical outcome.

Three cases of arteriovenous malformation (AVM) of the lung are presented. The first patient was 36-year-old female and the second was 25-year-old male, and both with asymptomatic bilateral multiple small AVMs. We used coil spring occlusion in therapeutic transcatheter embolization of the AVMs. A pulmonary arteriogram confirmed the completely occluded AVMs. The another patient was 21-year-old female whose lips and nails were cyanotic. She had clubbing fingers and vascular murmur was audible on her chest wall. The laboratory examination revealed polycythemia and hypoxemia. A pulmonary angiogram revealed a single large AVM which was composed of a feeding artery (A9) and a draining vein (dilated basal pulmonary vein). We performed a left basal segmentectomy and postoperative course was uneventful. Transcatheter embolization is useful for the case of multiple or peripheral or small AVM of the lung, but the case of large solitary AVM with rapid blood flow is thought to be an indication for the operation. These two therapeutic modality should be selected case by case.

Stereotactic radiotherapy using linear accelerators (Linac-knives) is a promising approach for treatment of metastatic brain tumors, arterio-venous malformations, and benign brain tumors. The advantages of the linac-knife over the Gamma knife are its capacity for stereotactic fractionated radiotherapy and to extend the indication for head and neck tumors and cervical spinal tumors.

The term "radiosurgery" was defined by Lars Leksell, a Swedish neurosurgeon, as the closed-skull destruction of a precisely defined intracranial target using high-dose radiation with stereotactic technique in a single session. For this purpose, the Gamma Knife was developed in 1968. It was equipped with multiple cobalt 60 sources and delivered collimated narrow radiation beams precisely concentrated to the focus. The dose gradient in the periphery of the treatment volume is extremely steep, so a high dose can be delivered to the small target volume sparing the surrounding normal tissue. Treatment planning was directed using a computer program developed for Gamma Knife and stereotactically obtained imaging database. The treatment procedure may be completed in only one day. The Gamma Knife makes it possible to treat deep-seated and surgically inaccessible lesions with low mortality and morbidity, and to control conventionally radioresistant lesions. Up to now, over 10,000 patients have undergone radiosurgery with a Gamma Knife around the world. The indications were primarily functional disorders, then expanded to include arterio-venous malformation (AVM), benign and a few malignant brain tumors. Excellent results were noted in the treatment of AVM. The two-year total obliteration rate of the nidus was 71-87%, and the adverse effect rate was 3-12%. The control rates of acoustic tumors was reportedly 85-89% with a lower incidence of facial nerve injury and a higher rate of hearing preservation. Gamma Knife radiosurgery has also been used to treat meningioma, pituitary adenoma and metastatic brain tumors. Its application for the treatment of malignant glial tumors or other tumors is developing. The capability of this technique is growing, and radiosurgery will be one of the important treatment modalities for selected neurosurgical or other pathological conditions.

Spinal arteriovenous malformation (AVM) is a relatively rare disease. We assessed the results of treatment of spinal AVM in 17 patients. Our classification was based on the radiographic appearance in selective spinal angiograms. There were 3 cases of single coiled type AVM, 3 of juvenile type, 5 of glomus type, and 6 of so-called dural AVM. All three patients with single coiled type AVM underwent microsurgical resection of the AVM. All three with the juvenile type underwent artificial embolization. Both patients with glomus type and dural AVM were treated by either embolization and/or surgery. Magnetic resonance imaging and magnetic resonance angiography visualized the spinal AVM well, and were useful for diagnosis and post-treatment follow-up.

A forty-eight year-old woman who had suffered from exertional dyspnea and cyanosis since her youth was found to have abnormal shadow in her right lower lung at the roentgenographic examination. Pulmonary angiography showed cavernous network between pulmonary artery and vein of the 8th, 9th, and 10th segments. Bronchial artery was dilated, supplying the cavernous lesion. From these findings this lesion was diagnosed as pulmonary arteriovenous malformation feeded by bronchial artery. Right lower lobectomy was performed. The effect of resection was confirmed by intraoperative arterial gas analysis before and after the excision. She has been doing well without any signs of recurrence for 3 years after the surgery.

An 18-month-old boy was admitted to our hospital with sudden onset of paraplegia, analgesia of the lower limbs, dysuria and constipation. His gestational and birth histories were unremarkable. Past history revealed he had lymphangioma in his left inguinal region, and had been treated in another hospital. Neurological examination revealed flaccid paraplegia, analgesia below Th12 dermatome and dysuria. MRI revealed an intramedullary high intensity lesion surrounded by round low intensity areas located from TH11 to L2 vertebral levels, suggesting the existence of vascular tumor or spinal AVM. Spinal angiogram revealed arteriovenous fistula with large intramedullary aneurysmal vascular dilatation from T12 to L2 vertebral level. The feeder was the Adamkiewicz artery which branched from the left Th12 intercostal artery. First, artificial embolization with thrombin gelfoam was performed successfully. However, follow-up MRI showed an image of flow void in the aneurysm again, indicating recanalization of the AVF. Therefore, an operation was undertaken on October 24th, 1988. The patient was placed in prone position and osteoplastic laminotomy from Th10-L2 was performed. The thrombus and wall of the aneurysm were mostly removed through the lumbosacral midline myelotomy for decompression. Then, the feeder and drainers were ligated. Postoperative course was uneventful. 2.5 years after the operation, he still had flaccid paralysis at the ankle joints bilaterally, analgesia below L4 dermatome, neurogenic bladder and constipation.(ABSTRACT TRUNCATED AT 250 WORDS)

A successful treatment of coronary arteriovenous fistula with intraoperative echocardiogram and Symbas procedure is presented. The patient, a 2-year-old male, had been suffering from concealed congestive heart failure from his birth. The cardiac catheterization and angiogram revealed coronary arteriovenous fistula from LAD to right ventricle with large coronary aneurysm. In the operation, no fistula vessels were noted on the cardiac surface. Then, the intraoperative echocardiography was performed, and the fistula pour into right ventricle with aneurysm was found in the myocardium. The fistula was closed with Symbas procedure, and excellent closure could be checked with the intraoperative echocardiogram, too. After this operation, he got well under anticoagulant treatment with "ticlopidine".

A 19-year-old man was admitted with the chief complaint of a sudden onset of thoracic pain and paraplegia. His right lower limb had progressively enlarged since he was 3 months old. Transient paraparesis had occurred recurrently since the age of 3. Physical examination on admission revealed that there were multiple warts on his face, trunk and right extremities. The right lower limb was thicker and longer than the left one, and the temperature was 1 degree C higher in the right side. Neurological examination revealed paraplegia and severe impairment of all sensory modalities below Th4 with bilateral clonus. Radiological examination showed lordosis of the thoracic spines with thinning of the pedicles of Th4 to Th6. Selective spinal angiography showed a juvenile type of arteriovenous malformation involving the cord of Th2 to Th6 with multiple feeding arteries, and a glomus type of the lower thoracic cord with the feeding arteries from Adamkiewicz's artery and the right Th10 intercostal artery. MRI showed the cord enlargement of Th2 to Th6 and within it the nidus was identified. Spinal arteriovenous malformations associated with Klippel-Trénaunay-Weber syndrome were noticed. The patient underwent interruption of the main feeding artery and removal of the dilated vessels located in the dorsum of the thoracic cord. Postoperative course was uneventful with slight improvement of clinical symptoms. Klippel-Trénaunay-Weber syndrome is manifested by a triad of symptoms: 1) hemihypertrophy of the extremities, 2) cutaneous hemangiomas and 3) arteriovenous fistula or varicose veins of the involved limbs. Nineteen cases of Klippel-Trénaunay-Weber syndrome associated with spinal arteriovenous malformation have been reported. The pathogenesis has been suggested to be due to developmental abnormalities.

We report a case of a 59-year-old male who suddenly developed massive right hemothorax and shock due to pulmonary arteriovenous malformation (AVM). He was admitted as an emergency case because of severe back pain, cyanosis and cold sweat. Although shock with massive right hemothorax was found, echocardiographic and X-ray computed tomographic examination showed no dilatation of the aorta, no intimal flap in the aorta and no pericardial effusion which suggested aneurysm. Pulmonary arteriography, performed subsequently, disclosed intrapleural rupture of the right pulmonary AVM. The patient recovered successfully from the state of shock. The pulmonary AVM was removed by segmentectomy of the right lung (S4). He was discharged following an uneventful postoperative course. Intrapleural rupture with shock is a very rare complication of pulmonary AVM. Pulmonary AVM should be considered as one possible cause in patients with massive hemothorax and shock.

A 59-year-old female was hospitalized because of disturbance of consciousness and convulsive seizures. She had taken a hormonal drug for 15 months after breast cancer surgery. A computed tomography scan revealed multiple high-density areas in the left temporal and frontal and the right parietal lobes. Angiography showed a dural arteriovenous malformation (AVM) in the posterior fossa fed by the occipital and the middle meningeal arteries and draining into the transverse sinus. It also demonstrated occlusion of the left sigmoid sinus in the venous phase. She complained of headache in the occipital region and dizziness. On day 13, the left occipital artery was ligated and cut, and then abnormal arterial anastomoses around the lesion were coagulated. After surgery, clinical symptoms disappeared. The etiology of dural AVM is controversial, but in this case it is suspected that sinus thrombosis due to the drug caused the dural AVM. The authors discuss the etiology and treatment of dural AVM in the posterior fossa.

Embolization and detached balloon occlusion by the femoral route were performed in 45 cases: 19 cases of meningiomas, 5 of scalp arteriovenous malformations (AVMs), 4 of dural AVMs, 6 of cerebral AVMs, 8 of facial angiomas and 3 of carotid cavernous sinus fistulas (CCFs); and favorable results were attained. In meningiomas, there is only a short interval between the embolization and the removal of tumor (we usually perform the embolization a couple of days before the removal), and we use Gelfoam as embolus material. We aim at central tumor embolization with small emboli. The embolization reduced bleeding in removing the tumors, simplifying the surgical procedure, and 12 of 19 cases required no blood transfusion. Almost all cases of scalp AVMs, dural AVMs and facial angiomas could most probably be cured only by the embolization without surgery. Gelfoam was the first choice, because it would probably dissolve, and also because it would be relatively safe even if pulmonary embolism might occur as a result of probable passage of its emboli onto the venous side. In recanalized cases, the embolization was performed again with Ivalon, a permanent embolus material. The most important of this procedure is to inject the emboli of the suitable size for each case together with a suitable contrast material at as low a rate as possible under the image intensifier. Embolization by the injection pressure should never be tried, but the emboli be allowed to be carried only on the blood flow to the distal side. And the embolization should be discontinued at the stage when the contrast material has stagnated. CCFs are very good indications for the detached balloon occlusion, while this technic proved to serve for no more than occluding the feeding vessels in cerebral AVMs; in other words, it is indicated in a rather limited range of AVMs. We have encountered no severe complications in any of the cases treated by the embolization and detached balloon occlusion.