Multiple Arteriovenous Malformations Research Articles

Genotype–phenotype correlation in hereditary hemorrhagic telangiectasia: Mutations and manifestations*

Hereditary hemorrhagic telangiectasia (HHT) is a genetically heterogeneous vascular dysplasia with multiple telangiectases and arteriovenous malformations and it is caused by mutations in endoglin gene (ENG) (HHT1) and activin A receptor type II-like 1 gene (ACVRL1) (HHT2). We evaluated 111 patients with HHT from 34 families by history, examination, screening for vascular malformations, and sequencing of both genes. We found mutations in 26 of the 34 kindreds (76%) analyzed-54% were in ENG and 46% were in ACVRL1. Mutations in ACVRL1 cluster largely in exons 7 and 8, but ENG mutations were widely distributed within that gene. We found that epistaxis had an earlier onset in patients with HHT1 than those with HHT2, but the severity by middle ages was similar. Pulmonary arteriovenous malformations were more frequent and on the average of larger size in HHT1. Hepatic vascular malformations were more common in patients with HHT2. Cerebral arteriovenous malformations were more common in patients with HHT1, but spinal arteriovenous malformations were seen only in patients with HHT2. Truncating mutations in ENG were associated with more affected organs and more severe hemorrhaging than were missense mutations. We conclude that HHT2 has a later onset than HHT1 and the former may disproportionately involve smaller vessels in tissues with more significant vascular remodeling.

A Case of Embolization Seen in Pulmonary Arteriovenous Malformation in a Patient with Osler-Rendu-Weber Syndrome

Osler-Rendu-Weber Syndrome or hereditary hemorrhagic telangiectasia (HHT) is characterized by telangiectasia of the skin and of the mucous membranes and intermittent bleeding from vascular abnormalities; in about 20% of the patients pulmonary arteriovenous malformation is present. Pulmonary arteriovenous malformation is a congenital anomaly in the lung which causes shunting of venous blood in the pulmonary artery to systemic circulation, resulting in cyanosis, polycythemia and clubbing. Recently we experienced a case of multiple pulmonary arteriovenous malformation associated with the telangiectatic change of the cerebral artery in a 16-yearold male patient, which was confirmed by pulmonary angiography. (Korean Circulation J 2006;36:820-822)

Laparoendoscopic Techniques for Occult Gastrointestinal Bleeding

Up to 5% of gastrointestinal bleeds occur between the ligament of Treitz and the ileocecal valve. These patients present with occult bleeding and pose diagnostic and therapeutic challenges. Currently, an array of technology exists for diagnostic purposes, including upper and lower endoscopies, capsule endoscopy, nuclear scans, angiography, and intraoperative endoscopy. All of these modalities have advantages and disadvantages. However, the diagnostic gold standard for occult gastrointestinal bleeding does not exist. We present a case of an 18-year-old male with occult gastrointestinal bleeding to illustrate the variety of available modalities. Initially, the patient underwent upper, lower, and push endoscopies. Subsequently, he had a nuclear bleeding scan, video capsule endoscopy, and an angiogram. Ultimately, the patient had a diagnostic laparoscopy with mobilization of the terminal ileum and right colon. The bowel was exteriorized and an intraoperative endoscopy was performed through a small bowel enterotomy. Multiple arteriovenous malformations (AVMs) were ascertained and resected. This case is presented in detail and the technique of intraoperative endscopy is reviewed. The diagnostic literature regarding AVMs is also reviewed.

Surgical treatment of recurrent transient ischemic attacks and hemoptysis in a young man with multiple pulmonary arteriovenous malformations

against heparin and platelet factor. Desensitization is not a therapeutic option for acute or delayed HIT. Cases have been reported in which alternative drugs, such as bovine heparin, ancrod, and argatroban, have been used in place of heparin when anaphylactoid reactions are suspected; however, their efficacy has been anecdotal and needs further investigation. Two reports exist in the literature in which desensitization for heparin allergy was attempted before cardiopulmonary bypass. Until more experience is gained with the use of alternative anticoagulation agents for cardiopulmonary bypass, we advocate the use of heparin desensitization as successfully performed in this case.

Hereditary Hemorrhagic Telangiectasia (HHT): Diagnosis, Treatment, and Nursing Implications in the Radiology Setting

Hereditary hemorrhagic telangiectasia (HHT) is described as a multisystem vascular dysplasia characterized by multiple arteriovenous malformations (AVMs). It is an autosomal-dominant disorder caused by a mutation of at least 1 or 2 genes. AVMs that are void of intervening capillaries result in direct connections between arteries and veins. Small AVMs, or telangiectases that appear close to the surface of the skin or mucous membranes often rupture and bleed after slight trauma to the affected area. AVMs can be superficial to the more severe cases of GI bleeding, cerebral hemorrhage, and major pulmonary shunting. Shunting of air, thrombi, and bacteria through pulmonary AVMs may cause transient ischemic attack, embolic stroke, or cerebral abscess. HHT occurs in all ethnic and geographic areas, and the overall incidence of HHT in North America is estimated to be about one in five thousand people. The University of Pennsylvania Medical is one of eight centers in North America that has been designated as an HHT Center for Excellence by the HHT Foundation International. The Division of Medical Genetics at Penn works closely with diagnostic radiology, CT and MRI scanning, neuroradiology, neurology, pulmonary medicine, and, when appropriate, coordinates embolization procedures with the interventional radiology department. Patients with HHT receive comprehensive care for the diagnosis, management, and treatment of their disease at the University of Pennsylvania Medical Center. This presentation included information on the disease physiology as well as modes of definitive diagnosis via clinical presentation, diagnostic radiology, and genetic testing. The University of Pennsylvania Medical is one of two centers in the United States that performs genetic testing for mutations in either the endoglin or ALK 1 genes. Case study presentations include angiography films of pulmonary embolizations and patient interviews and specifically center around nursing implications and special care that these patients need from all healthcare professionals.

Small Bowel Polyps and Angiodysplasia Discovered by Video-Capsule Endoscopy in a Ten-Year-Old with Peutz-Jeghers Syndrome

Case Presentation: Hispanic female presented at age 7 years with chronic abdominal pain and noticed to have melanotic pigmentation of her of lips, oral mucosa, and hands. Upper GI series (UGI) revealed a small ovoid persistent filling defect in the proximal fundus suspicious for a sessile polyp. Small bowel follow-through (SBFT) was normal. At endoscopy, gastritis, three small gastric polyps and one duodenal polyp were identified. Two harmatomatous colonic polyps were removed from the rectosigmoid area at colonoscopy. She did well and was asymptomatic except for a few episodes of blood in her stools. Reevaluation at age ten years. UGIS/SBFT were negative. Colonoscopy discovered a hamartomatous polyp measuring 1.5 cm at the anal verge, and smaller ones measuring 0.3–0.5 mm in the rectum and sigmoid. The cecum and terminal ileum were normal. A M2A video-capsule was delivered via endoscopy into the duodenum, and released from a Roth net. Several polyps measuring approximately 3 mm in diameter were observed in the duodenum and proximal jejunum, as well as multiple (>10) arteriovenous malformations. Numerous polyps (>100) with an average size of 1 mm in diameter were found in the area extending from the mid-jejunum to the distal ileum. The terminal ileum had normal appearing mucosa. Conclusion: Our patient had pigmentation on her lips, hands and buttocks and several gastric, small bowel and colonic lesions which are consistent with Peutz-Jeghers syndrome (PJS). This case seems to be a sporadic mutation as there were no family members with any findings of PJS. The abdominal pain resolved after treatment with acid-suppressive therapy suggesting gastritis and not polyps as the etiology of her symptoms. The most striking findings in this patient were the multiple arteriovenous malformations (AVM) throughout the small bowel and numerous small bowel polyps discovered by video-capsule. The previous endoscopic evaluations and ragiography, failed to detect these AVM. Upper intestinal endoscopic evaluations and enteroscopy are limited due to the length of the small bowel, therefore distal areas cannot be reached. Polyps as well as AVM in these distal regions will be undetected by routine endoscopy, enteroscopy as well as by radiography as evidenced in this case. With the introduction of the video-capsule methodology the entire small bowel can be examined and, as application increases, AVM's may be discovered more frequently as an associated finding of PJS.

Segmental arterial ligation under video-assisted thoracoscopy combined with transcatheter embolotherapy for multiple bilateral pulmonary arteriovenous malformations

Multiple bilateral pulmonary arterio-venous malformations (PAVM) were diagnosed in a 15-year-old girl with erythrocytosis. Although transcatheter embolotherapy is generally accepted as a treatment of PAVM, the largest lesion in the right lower lobe was fed by a 13-mm diameter feeding artery without downstream narrowing, which was unsafe for the embolization of coils or balloons. Instead, we surgically ligated the largest feeding artery under video-assisted thoracoscopy, without losing any lung parenchyma. The other PAVM were successfully treated by embolization of metallic coils. The arterial partial pressure of oxygen (O(2)) increased from 37 to 64mmHg on room air, and from 46 to 410mmHg on 100% O(2).

Transcatheter embolization of multiple bilateral pulmonary arteriovenous malformations in hereditary hemorrhagic telangiectasia

A 38-year-old woman with hereditary hemorrhagic telangiectasia (HHT) presented with exertional dyspnea and central cyanosis related to multiple bilateral pulmonary arteriovenous malformations (PAVM). Transcatheter embolization of the PAVMs resulted in resolution of systemic arterial desaturation and clinical symptoms. PAVMs in HHT can be effectively treated by transcatheter embolization even when bilateral and numerous.

The value of screening for multiple arterio-venous malformations in hereditary hemorrhagic telangiectasia: a diagnostic study.

Occult visceral arterio-venous malformations (AVMs) may be a constant threat to patients suffering from hereditary hemorrhagic telangiectasia (HHT), also known as Rendu-Osler-Weber syndrome (M. ROW). HHT patients predominantly become symptomatic through chronic, recurrent epistaxis, a symptom that can alert physicians at an early stage of the disease. The purpose of this study was to investigate whether occult, visceral arterio-venous malformations could be detected by screening imaging studies in patients suffering from HHT. In a comprehensive diagnostic study, Rendu-Osler-Weber patients were examined for potential visceral arterio-venous malformations by physical examination and non-invasive imaging techniques. The Department of Otolaryngology of the Philipps University of Marburg is a major referral center and coordinated the screening procedures. Thirty-five individuals with the presumed diagnosis of HHT gave informed consent to the screening investigations. Eighteen of 35 individuals were found to suffer from visceral vascular malformations; most of the AVMs were diagnosed in the lung, but also the liver, spleen, brain and eyes were affected. Six patients could be treated preventively by arterial embolization for AVMs of the lung, liver and brain. Comprehensive screening for occult AVMs in HHT patients seems to be justified to avert potential complications in this group of patients.

Video-assisted anatomic mediobasal segmentectomy of lung

Although video-assisted thoracic surgery (VATS) is now widely accepted, pulmonary segmentectomy is rarely performed. We present a case series of patients undergoing this procedure. The first patient had multiple arteriovenous malformations of the right mediobasal segment and a leiomyoma in the bronchus of the mediobasal segment. The second patient had multiple pulmonary metastases from colon cancer, including one in the right mediobasal segment. The third patient had metastases in the right ventrobasal and mediobasal segments from a solitary fibrous tumor that originated in the contralateral diaphragm. In the first two patients, a solitary mediobasal segmentectomy was done. In the third patient, a combined ventrobasal and mediobasal bisegmentectomy was performed. There were no complications, and visualization was excellent. Because VATS provides such excellent exposure, mediobasal segmentectomy of the lung is feasible, even though this operation is not done as an open procedure.

Embolization of multiple spinal arteriovenous malformations in Cobb syndrome causing high output heart failure: report of a case

Cobb syndrome is the combination of a vascular skin nevus and an angioma in the spinal cord corresponding to the dermatome involved. We report a case of Cobb syndrome in a female with high output heart failure who was successfully recovered by embolization with Contour emboli and microcoils.

Endoscopic cryotherapy for the treatment of bleeding mucosal vascular lesions of the GI tract: A pilot study

Background: Thermal therapy is the cornerstone of endoscopic treatment of bleeding mucosal lesions of the GI tract. However, there is a 20% failure rate and contact devices may be cumbersome in the treatment of large bleeding areas. A pilot study was conducted to evaluate the safety and efficacy of endoscopic cryotherapy for bleeding mucosal vascular lesions. Methods: Patients with recurrent bleeding from diffuse mucosal vascular lesions were treated with cryotherapy and had endoscopic and clinical follow-up. Results: Twenty-six patients with gastric and duodenal arteriovenous malformations (n = 7), watermelon stomach (n = 7), radiation-induced gastritis (n = 5), and radiation-induced proctitis (n = 7) were treated with mean of 3.4 (1.6) sessions. The best results were achieved in patients with radiation-induced proctitis, with cessation of bleeding in all 7 patients. Cryotherapy was also effective in patients with multiple arteriovenous malformations (86%) and watermelon stomach (71%). It was less effective in patients with radiation-induced damage to stomach and duodenum, although all patients in this group were debilitated because of disseminated malignancy. Conclusions: Cryotherapy is a safe and effective treatment for bleeding from diffuse mucosal lesions of the GI tract. Bleeding from radiation-induced proctitis and multiple arteriovenous malformations is particularly responsive to endoscopic cryotherapy.

Development of multiple cerebral arteriovenous malformations documented in an adult by serial angiography

A 50-year-old woman with a parietal intracerebral hematoma was initially treated by hematoma evacuation. Initial preoperative and follow-up angiograms obtained 6 months later demonstrated no pial arteriovenous malformations (AVMs). She suffered a subarachnoid hemorrhage 8 years later. Results of follow-up cerebral angiography revealed the development of previously undetected multiple cerebral AVMs. This appears to be the first reported case of the development of multiple cerebral AVMs in an adult, demonstrated on serial angiography.

Embolization of multiple spinal arteriovenous malformations in Cobb syndrome causing high output heart failure: report of a case

Embolization of multiple spinal arteriovenous malformations in Cobb syndrome causing high output heart failure: report of a case

Long-term results of ileum interposition for ureteral obstruction.

To present the long-term results of ileum interposition in the ureter for uni- or bilateral ureteral obstruction. Between 1981 and 2000, a total of 22 patients received an ileal segment interposition as a substitution for the ureter, of whom 18 were available for analysis. The mean age was 54 years (range 29-73). Patients were followed for a mean period of 65 months (range 2-196). Assessment included clinical examination, serum creatinine levels, renal ultrasonography, intravenous pyelography and isotopic renography. In eight patients, the ileal-ureteral substitution was the first reconstructive procedure. The other patients underwent up to four previous reconstructions of different types. Fourteen patients were treated for unilateral ureteral obstruction, four of whom had a functional or anatomical solitary kidney, the other four patients had bilateral obstruction. In 16 patients renal function improved after ileal-ureteral substitution. One patient underwent a nephrectomy because of a decreased renal function due to an obstruction at the level of the uretero-ileal anastomosis. One patient had a nephrectomy because of recurrent macroscopic hematuria caused by multiple arterio-venous malformations. Overall, 15 patients (83%) had a good functioning kidney after a mean period of 65 months. In three patients an early reintervention was necessary because of bleeding, small bowel obstruction and urinary leakage from a pyelo-ileal anastomosis. Six patients required a reintervention in the long-term: two had a nephrectomy, three had a re-anastomosis between the renal pelvis and the proximal ileal segment, while the sixth patient underwent a PNL for a kidney stone. Recurrent urinary tract infections were seen in six patients, of whom three had to undergo a reintervention. Metabolic acidosis was detected in two patients and was treated with sodium bicarbonate substitution. Ileal-ureteral substitution is a valuable procedure with good long-term results and an acceptable rate of secondary interventions in patients for whom other alternatives are not feasible.

A Case of Multiple Pulmonary Arteriovenous Malformation in Pregnancy

A pulmonary arteriovenous fistula is an uncommon malformation. In pregnancy altered hemodynamics and hormones cause changes in a PAVM(pulmonary arteriovenous malformation) that predispose them to deterioration. Therefore, a PAVM can cause serious and life-threatening complications in pregnancy. Death often results from a cerebral abscess and a rupture of the malformation with a massive hemorrhage. Recently, we experienced a case of a multiple PAVM in pregnant 38 year old woman, which could not be observed in the old chest PA, 1 year ago. The PAVM was confirmed by CT and was angiography and treated by percutaneous embolization. The patient is suspected to have HHT (Hereditary hemorrhagic telangiectasia).

A case of multiple arteriovenous malformations of the colon with gastrointestinal bleeding diagnosed by colonoscopy

A case of multiple arteriovenous malformations of the colon with gastrointestinal bleeding diagnosed by colonoscopy

Associated Cerebral and Spinal AVM in Infant and Adult

We report two cases of a rare association of brain and spinal arteriovenous malformation (AVM) in an infant and in an adult. Both patients were embolised with glue with good clinical and morphological results. The first patient is an infant with a suspected family history of Rendu Osler Weber disease with multiple AVMs : two hemispheric cerebellar lesions (one of them revealed by a ventricular haemorrhage) and one cervical spinal cord AVM (SCAVM). The associated SCAVM fortuitously bled one month after treatment of the symptomatic cerebellar AV shunt. In the adult case, the management first involved a symptomatic SCAVM with favourable outcome; the cerebral AVM bled secondarily and was then excluded by endovascular approach.

Wyburn–Mason Syndrome Variant Treated with Stereotactic Radiosurgery

Classical Wyburn–Mason syndrome consists of unilateral arteriovenous malformations affecting the retina, midbrain, and visual pathways in the brain, and the facial structures. An unusual case of Wyburn–Mason syndrome with bilateral manifestations and without retinal involvement is described. A 19-year-old girl presented at the age of 5 with a left hemiparesis and aphasia following intracerebral hemorrhage in the right internal capsule and basal ganglia. Angiography demonstrated left sylvian, right frontoparietal, and right thalamic arteriovenous malformations (AVMs). In addition to multiple intracranial AVMs, she had multiple telangiectatic lesions scattered over her body. Ophthalmological examination was normal except for left orbital bruit. Two years later, with moderate clinical improvement, she had proton beam radiosurgery for her multiple AVMs. Due to lack of beneficial effect, repeat radiosurgery with more appropriate dose is under consideration. A review of the literature revealed that our presenting case represents one of the few reported cases of atypical Wyburn–Mason syndrome with bilateral manifestations and without retinal involvement. To our knowledge, ours represent the first reported case for which radiosurgery had been offered as a treatment modality.

Multiple cranial arteriovenous malformations in a child with eventual blindness in the affected eye

PURPOSE: To report a case of multiple cranial arteriovenous malformations involving the orbit and retina. METHOD: Case report. We treated a 7-year-old girl who was diagnosed with a left submaxillary, a left retinal, a left orbital, and a middle subdural arteriovenous malformation. RESULTS: Enlargement of the arteriovenous malformations, except for the retinal arteriovenous malformation, was observed. After external carotid artery embolizations and radiation therapy for uncontrolled oral cavity bleeding, loss of light perception in the affected eye occurred, but no marked changes occurred in the retinal arteriovenous malformation. CONCLUSION: This rare case suggests that the clinical finding of a stable retinal arteriovenous malformation may be associated with enlargement of arteriovenous malformation lesions at other sites.