Brain arteriovenous malformations associated with hereditary hemorrhagic telangiectasia: gene-phenotype correlations

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant genetic disease with a wide spectrum of vascular malformations (VMs) involving multiple organs. Nine to 16% of patients with HHT harbor brain arteriovenous malformations (AVMs), which can cause intracranial hemorrhage (ICH). Our objective was to study clinical manifestations of brain AVMs in patients with HHT and correlate these with the specific gene mutated. We reviewed records of 171 patients with HHT and brain AVMs. A history of ICH was found in 27% (41/152) patients, with a mean age of 26 ± 18 range, (0-68) years. All of patients with ICH were neurologically asymptomatic prior to ICH. Multiple brain AVMs were found in 23% (170/39) of patients on initial examination. Genetic test results were available in 109 (64%) patients. Mutations in ENG, ACVRL1, and SMAD4 were present in 75 (69%), 18 (17%), and 2 (2%), respectively. A history of ICH was reported in 24% of patients with an ENG mutation and 27% of patients with an ACVRL1 mutation, with a mean age of 26 ± 16 (range, 2-50) and 18 ± 21 (0-48) years, respectively. No statistically significant differences in age at first brain AVM diagnosis, prevalence of ICH history, age at ICH, or other manifestations of brain AVMs were observed among gene groups. In conclusion, no evidence for differences in brain AVM characteristics was observed among HHT gene groups, although we cannot exclude clinically important differences. Larger studies are needed to further guide brain AVM screening decisions in patients with HHT.

The Young's Procedure for Severe Epistaxis from Hereditary Hemorrhagic Telangiectasia

Background

Surgical treatment of epistaxis in hereditary hemorrhagic telangiectasia (HHT) has historically been managed with the laser procedure or the septodermoplasty procedure. For transfusion-dependent patients with severe epistaxis we have been performing the Young's procedure or surgical closure of the nostrils. The objective of this study was to report treatment of severe epistaxis related to HHT with the Young's procedure and assess patient outcome.

Methods

Patients with severe iron or blood transfusion–dependent epistaxis who underwent a Young's procedure in three otolaryngology HHT centers were reviewed. Patients were evaluated for postoperative epistaxis and subjective outcome.

Results

Forty-three patients underwent a Young's procedure for severe epistaxis and were observed for a mean of 34 months. The procedure was well tolerated by all patients and 30 of 36 patients (83%) experienced complete cessation of bleeding after the Young's procedure. Patients had a mean increase in hemoglobin of 4.68 g/dL after the procedure. The average Glasgow Benefit Inventory score after surgery was 43.56. No patients requested a reversal of the procedure.

Conclusion

The Young's procedure is a safe and efficacious procedure with complete cessation of epistaxis in most patients with severe epistaxis and HHT.

Hemothorax due to rupture of pulmonary arteriovenous malformation: an interventional emergency

Spontaneous hemothorax as a result of a ruptured pulmonary arteriovenous malformation (PAVM) is a life-threatening event and requires immediate interventional therapy. We present two patients who survived following emergent embolization. Definitive thoracentesis was delayed until embolization was performed. The tamponade provided by the hemothorax may have prevented exsanguination, suggesting to us that drainage of blood from the pleural space should be delayed until the PAVM has been treated. Hemorrhage from a PAVM may be the first manifestation of hereditary hemorrhagic telangiectasia. Genetic testing and screening for other family members should be considered.

Overlapping spectra of SMAD4 mutations in juvenile polyposis (JP) and JP-HHT syndrome

Juvenile polyposis (JP) and hereditary hemorrhagic telangiectasia (HHT) are clinically distinct diseases caused by mutations in SMAD4 and BMPR1A (for JP) and endoglin and ALK1 (for HHT). Recently, a combined syndrome of JP-HHT was described that is also caused by mutations in SMAD4. Although both JP and JP-HHT are caused by SMAD4 mutations, a possible genotype:phenotype correlation was noted as all of the SMAD4 mutations in the JP-HHT patients were clustered in the COOH-terminal MH2 domain of the protein. If valid, this correlation would provide a molecular explanation for the phenotypic differences, as well as a pre-symptomatic diagnostic test to distinguish patients at risk for the overlapping but different clinical features of the disorders. In this study, we collected 19 new JP-HHT patients from which we identified 15 additional SMAD4 mutations. We also reviewed the literature for other reports of JP patients with HHT symptoms with confirmed SMAD4 mutations. Our combined results show that although the SMAD4 mutations in JP-HHT patients do show a tendency to cluster in the MH2 domain, mutations in other parts of the gene also cause the combined syndrome. Thus, any mutation in SMAD4 can cause JP-HHT. Any JP patient with a SMAD4 mutation is, therefore, at risk for the visceral manifestations of HHT and any HHT patient with SMAD4 mutation is at risk for early onset gastrointestinal cancer. In conclusion, a patient who tests positive for any SMAD4 mutation must be considered at risk for the combined syndrome of JP-HHT and monitored accordingly.

Results of exercise stress testing in patients with diffuse pulmonary arteriovenous malformations

Patients with diffuse pulmonary arteriovenous malformations (PAVMs) are subject to frequent complications and need to be followed closely. As part of this follow-up, we have employed exercise stress testing (EST) as an aid to assess their status. Twenty patients from a cohort of 35 with diffuse PAVMs have undergone EST using a standard cycle ergometer test. All patients had previously undergone pulmonary angiography, noncontrast chest computed tomography (CT), and repair of large focal PAVMs, prior to EST. Mean room air oxygen saturation at baseline and at maximum exercise (85% of maximum heart rate) were tabulated. Serial studies in six children and young adults were plotted by year and compared using the patient as their own control. Fourteen females and six males ranging in age from 4 to 50 years (mean 22 years) were studied. Baseline mean oxygen saturation was 84% and fell to 73% at maximum exercise. There was no significant difference between those with unilateral and bilateral involvement (P = 0.09). In four of the six patients with serial EST, the baseline and exercise oxygen saturations were quite stable. In the two patients who became symptomatic, with age, growth, and more activity, complete embolization of one or more segments of the lung improved their EST and functionality. Based on our previous work in patients with diffuse PAVMs, EST appears to offer a relatively safe and noninvasive method for assessing these patients. Our limited experience with serial EST suggests a good correlation with decreased functionality in these patients.

International guidelines for the diagnosis and management of hereditary haemorrhagic telangiectasia

BACKGROUND

HHT is an autosomal dominant disease with an estimated prevalence of at least 1/5000 which can frequently be complicated by the presence of clinically significant arteriovenous malformations in the brain, lung, gastrointestinal tract and liver. HHT is under-diagnosed and families may be unaware of the available screening and treatment, leading to unnecessary stroke and life-threatening hemorrhage in children and adults.

OBJECTIVE

The goal of this international HHT guidelines process was to develop evidence-informed consensus guidelines regarding the diagnosis of HHT and the prevention of HHT-related complications and treatment of symptomatic disease.

METHODS

The overall guidelines process was developed using the AGREE framework, using a systematic search strategy and literature retrieval with incorporation of expert evidence in a structured consensus process where published literature was lacking. The Guidelines Working Group included experts (clinical and genetic) from eleven countries, in all aspects of HHT, guidelines methodologists, health care workers, health care administrators, HHT clinic staff, medical trainees, patient advocacy representatives and patients with HHT. The Working Group determined clinically relevant questions during the pre-conference process. The literature search was conducted using the OVID MEDLINE database, from 1966 to October 2006. The Working Group subsequently convened at the Guidelines Conference to partake in a structured consensus process using the evidence tables generated from the systematic searches.

RESULTS

The outcome of the conference was the generation of 33 recommendations for the diagnosis and management of HHT, with at least 80% agreement amongst the expert panel for 30 of the 33 recommendations.

Comparison of four embolic materials at uterine artery embolization by using postprocedural MR imaging enhancement

PURPOSE

To test the hypothesis that not all embolic materials are equivalent by using postprocedural magnetic resonance (MR) imaging enhancement of uterine fibroids in patients treated with uterine artery embolization (UAE).

MATERIALS AND METHODS

Approval and a waiver of consent from the institutional human investigations committee was received for this study. The study was HIPAA compliant. A total of 84 women who underwent 6-month MR imaging follow-up constituted this retrospective study. Within this group, 25 women were treated with Contour polyvinyl alcohol (PVA) particles, 23 were treated with Contour SE particles, 19 were treated with Embosphere microspheres, and 17 were treated with Bead Block microspheres. Pre- and postprocedural MR imaging results were analyzed for the total number of fibroids present in the uterus of each patient and for the percentage of individual fibroid enhancement. Enhancement of individual fibroids was measured with quartile intervals. Greater than 25% residual enhancement of a fibroid after embolization was considered an incomplete infarction. The overall percentage change in enhancement was calculated for each patient. Bivariate analysis by using generalized linear modeling and one-way analysis of variance was used to assess differences in infarction with different embolic materials.

RESULTS

Among patients treated with Contour and Embosphere, there was a mean reduction in enhancement by 76.60% and 83.07%, respectively, compared with a mean reduction of 52.53% and 49.78% in patients treated with Bead Block and Contour SE, respectively. There was a significant difference in postembolization enhancement between Bead Block and Embosphere, Bead Block and Contour, Contour SE and Embosphere, and Contour SE and Contour.

CONCLUSION

Patients treated with Bead Block or Contour SE demonstrated a reduced degree of infarction at follow-up MR imaging compared with patients treated with Contour or Embosphere.

Pulmonary arteriovenous malformations: how do I embolize?

Pulmonary arteriovenous malformations (PAVM) are high-flow, low-pressure shunts, consisting of a single feeding artery connecting via an aneurysmal sac to a draining vein. The aneurysmal connection is referred to as an aneurysmal sac. The "filter capacity" of the pulmonary capillaries is lost and results in predisposition to brain abscess, stroke, and transient ischemic attack and, when multiple, dyspnea, because of right-to-left shunting and hypoxemia. PAVM are markers of hereditary hemorrhagic telangiectasia (HHT). Up to 30% of patients with HHT have PAVM complicating their disorder. Left untreated, 50% of patients with PAVM will develop disabling or fatal complications. In addition to stroke and transient ischemic attack syndromes due to passage of paradoxical emboli through the PAVM, rupture of the aneurysmal sac, particularly in the third trimester of pregnancy, can lead to fatal hemoptysis or hemothorax. Finally, brain abscess or more obscure musculoskeletal or spinal infections may be secondary to PAVM. Since detachable silicone balloons are no longer available, we have developed precise techniques for closing pulmonary malformations using pushable fibered coils. It is not the coil that is so important, but it is the use of coaxial or triaxial catheters that allow for precise placement of the coil. Cross-sectional occlusion is essential for embolization of PAVM and this is achieved using the "anchor" or "scaffold" technique. Our recent results indicate permanent involution of treated malformations with a 3% recurrence rate. All patients should be assessed for other manifestations of HHT before treatment and they are best followed in one of the 20 HHT Centers worldwide (www.hht.org).

Long-term complications of septal dermoplasty in patients with hereditary hemorrhagic telangiectasia

OBJECTIVE

Septal dermoplasty has been recommended as the treatment of choice for life-threatening epistaxis in patients with hereditary hemorrhagic telangiectasia. This study evaluates the complications of septal dermoplasty in the management of transfusion-dependent epistaxis.

STUDY DESIGN

Consecutive retrospective study.

SUBJECTS AND METHODS

Between 1994 and 2006, septal dermoplasty was performed on 106 consecutive patients with transfusion dependent epistaxis. Of 103 potential patients, 37 either died or were lost to follow-up, which left 66 patients for study. Data on complications and quality of life were collected on 50 (76%) of 66 patients (mean follow-up, 3.75 years) via phone interview.

RESULTS

Seventy-eight percent experienced nasal odor; 72% had nasal crusting; 58% had decreased sense of smell; 30% noted worsened sinus infection; 88% could breathe through their nose; 86% stated improved quality of life.

CONCLUSION

Septal dermoplasty remains an effective way of treating transfusion dependent epistaxis in patients with hereditary hemorrhagic telangiectasia and subjectively improves their quality of life.

Initial experience with 3% sodium tetradecyl sulfate foam and fibered coils for management of adolescent varicocele

PURPOSE

To report the results of treatment of adolescent patients with varicocele with use of 3% sodium tetradecyl sulfate foam (STS) in combination with pushable fibered coils.

MATERIALS AND METHODS

From September 2004 to September 2006, 16 adolescent patients (age 12-19 y) with symptomatic varicocele, testicular atrophy, or surgical recurrence underwent embolization with STS foam and coils. The left internal spermatic vein (ISV) was coaxially catheterized from the right femoral vein. Three percent STS foam was placed distally in the ISV during compression so minimal foam entered the pampiniform plexus. A second nest of coils was placed in the ISV at a position over the sacroiliac (SI) joint that occluded most of the parallel collateral vessels. Coils were not placed above the SI joint in most instances. Additional foam was injected in the ISV at the upper level of the SI joint. The upper ISV was left unoccluded. Our standard follow-up consisting of ultrasound and/or physical examination after varicocele occlusion was performed 2-12 months after the procedure.

RESULTS

All occlusions were technically successful, and 15 of 16 patients (94%) exhibited proven disappearance of the varicocele. All patients were asymptomatic except one who had pain despite disappearance of the varicocele. One patient with a bleeding disorder had 48 hours of scrotal discomfort as a result of pampiniform phlebitis caused by the deliberate passage of foam into the pampiniform plexus.

CONCLUSIONS

The use of 3% STS foam in combination with pushable fibered coils is a safe and effective sclerosing procedure for adolescent subjects with varicocele.

Septectomy and septal dermoplasty for the treatment of severe transfusion-dependent epistaxis in patients with hereditary hemorrhagic telangiectasia and septal perforation

BACKGROUND

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant disorder characterized by abnormal angiogenesis with resultant telangiectasia formation in mucocutaneous tissues, visceral organs, and the central nervous system. The most common manifestation of HHT is epistaxis resulting from trauma to thin-walled telangiectasias. Many patients with HHT experience worsened epistaxis due to the presence of a septal perforation. Septal perforation in HHT patients results from aggressive noncartilage sparing treatments such as monopolar cauterization. Although the mainstay of treatment for patients with severe transfusion-dependent HHT remains to be septal dermoplasty (SD), patients with a septal perforation are less likely to have a successful outcome. In this small subset of patients, septectomy (ST) combined with SD is proposed to eliminate this variable to improve skin graft uptake and therefore outcome. This study reviews the indications, procedure, and outcome of nine patients with severe transfusion-dependent HHT and septal perforation who underwent the combined procedure of SD/ST.

METHODS

Nine HHT patients with severe transfusion-dependent epistaxis and septal perforation underwent SD/ST at our institution over a 5-year period. Quality of life, including number of daily events of epistaxis, and transfusion requirements were determined before and after surgery. Technical aspects of the procedure as well as complications were reviewed.

RESULTS

The combined procedure of SD/ST resulted in a long-lasting subjective improvement in quality of life for all patients. Similarly, transfusion requirements were reduced from 22.61 to 9.57 (p < 0.05). There were no complications or increased morbidity from the procedure.

CONCLUSION

Combined SD/ST is a safe and effective treatment for HHT patients with transfusion-dependent epistaxis and septal perforation.

Value of Micronester coils in port-catheter implantation for continuous hepatic arterial infusion chemotherapy with fixed catheter tip method

To retrospectively evaluate the use of Micronester coils in port-catheter implantation with the fixed catheter tip method in comparison with other previously used coils. The cohort of this study was 143 consecutive patients with unresectable advanced liver cancer for whom a port-catheter system was percutaneously implanted. In the most recent 32 patients, Micronester coils were used for catheter tip fixation. Details of embolic agents for fixation, persistent blood flow beyond the distal end of the indwelling catheter, and complications were compared between cases without and with Micronester coils. In all, percutaneous port-catheter placement was successful. Mean number of coils used for fixation was 4.2 without Micronester coils vs. 2.5 with Micronester coils. N-butyl cyanoacrylate (NBCA)-Lipiodol was additionally used for catheter tip fixation in 85.6% of 111 procedures without Micronester coils and in 50% of 32 using Micronester coils. The gastroduodenal artery beyond the distal end was not detected at the final examination after any procedure. Catheter dislocation occurred in five and hepatic arterial obstruction or severe stenosis in eight. The number of coils used and necessity of NBCA-Lipiodol could be decreased with usage of Micronester coils without decreasing fixation ability compared to other coils.

Liver involvement in hereditary hemorrhagic telangiectasia: consensus recommendations

STUDY PURPOSE

To formulate recommendations about clinical management of liver involvement in hereditary hemorrhagic telangiectasia (HHT), using a formal consensus development process.

CONSENSUS PROCESS

A nominal group technique was used. A list of main clinical, diagnostic and therapeutic issues about liver involvement in HHT was generated by the organizing committee. Panel members then scored their agreement with each statement; the median score, and standard deviation for each statement were determined for each of the three successive panel rounds. These consensus statements formed the basis for recommendations graded with the strength and quality of supporting evidence.

RECOMMENDATION STATEMENTS

Doppler US is sufficiently accurate and suitable for first-line imaging of the liver in the general HHT population. Liver biopsy in any patient with proven or suspected HHT should be avoided. Liver involvement in HHT is generally asymptomatic; in the minority of patients where it is symptomatic, morbidity and mortality can be substantial. The prevalence of focal nodular hyperplasia is much higher in patients with liver involvement by HHT than in the general population. Invasive therapies for liver involvement by HHT (namely liver transplantation) should be considered only in patients who have failed to respond to intensive medical therapy.

Liver involvement in hereditary hemorrhagic telangiectasia: CT and clinical findings do not correlate in symptomatic patients

OBJECTIVE

The purpose of our study was to report the multiphasic CT findings in patients with symptomatic liver involvement by hereditary hemorrhagic telangiectasia (HHT) and to correlate the CT findings with the type of clinical presentation.

CONCLUSION

Patients with symptomatic HHT liver disease have diffuse hepatic telangiectases, a dilated common hepatic artery, and a high incidence of biliary abnormalities. Multiphasic CT is useful in diagnosing liver involvement due to HHT; however, no strong correlation was seen between CT findings and the clinical subtype of HHT liver disease.

Clinical and Anatomic Outcomes after Embolotherapy of Pulmonary Arteriovenous Malformations

PURPOSE

To assess long-term clinical and imaging results of technically successful pulmonary arteriovenous malformation (AVM) embolization.

MATERIALS AND METHODS

One hundred fifty-five patients with pulmonary AVMs underwent embolization during a period of 3 years. Recommended follow-up included clinical assessment, helical computed tomography, and physiologic evaluation within 1 year and then every 5 years.

RESULTS

Hereditary hemorrhagic telangiectasia was present in 148 patients (95%). Four hundred fifteen pulmonary AVMs were occluded during 205 procedures. Clinical follow-up was available in all patients over 3-7 years and imaging follow-up was available in 144 patients (393 lesions) over 1-7 years (mean, 2.9 y). Problems related to pulmonary AVMs occurred in 35 patients (23%) at 42 time points: 22 patients with 23 symptomatic events and 17 patients with 19 asymptomatic events. Symptoms resulted from growth of nonembolized pulmonary AVMs (n = 19), residual embolized pulmonary AVMs (n = 5), or both (n = 2). Symptoms consisted of respiratory manifestations (n = 13), cerebral ischemia (n = 4), brain abscess (n = 5), hemoptysis (n = 3), and seizure (n = 1). Imaging showed pulmonary AVM involution in 97% of embolized lesions and 11 residual lesions (2.8%) in 10 patients (6.9%). These were caused by recanalization (n = 7), presence of an accessory feeding artery (n = 1), pulmonary collateral vessels (n = 1), and bronchial collateral vessels (n = 2). CT detected 10 of the 11 residual lesions. Imaging detected 97 previously small pulmonary AVMs that had enlarged to a significant size in 28 patients (18%), 15 of whom were symptomatic and 13 of whom were asymptomatic.

CONCLUSIONS

Clinical and anatomic evaluation after pulmonary AVM embolization is important to detect persistent or reperfused lesions and enlarging lesions, with the latter more common. Patients with persistent, reperfused, or enlarging lesions often have symptoms, but a significant minority of patients are asymptomatic. More frequent assessment may improve detection before the onset of symptoms.

Outcome of septal dermoplasty in patients with hereditary hemorrhagic telangiectasia

OBJECTIVES/HYPOTHESIS

Septal dermoplasty has been recommended as the treatment of choice for life-threatening epistaxis in patients with hereditary hemorrhagic telangiectasia. The purpose of the study was to evaluate the effectiveness and outcomes of septal dermoplasty for management of transfusion-dependent epistaxis.

STUDY DESIGN

Retrospective study.

METHODS

Between 1994 and 2004, septal dermoplasty was performed on 67 consecutive patients with severe epistaxis attributable to hereditary hemorrhagic telangiectasia. The numbers of units of blood received 1 year before and 1 year after septal dermoplasty were obtained. A subjective appraisal of the results of the surgery as well as second procedures after septal dermoplasty was determined. Patients were screened for pulmonary and cerebral arteriovenous malformations, gastrointestinal tract bleeding, and symptomatic liver disease.

RESULTS

Data were obtained in 66 of 67 (98%) patients with a mean age of 61.5 years (mean follow-up, 3.9 y). Accurate transfusion requirements 1 year before and 1 year after septal dermoplasty were available in 32 of 66 (48%) patients. In these 32 patients, the mean units of blood received decreased from 21 units (range, 2-100 units) 1 year before septal dermoplasty to 1 unit (range, 0-10 units) in the year after septal dermoplasty (P < .001). Improved quality of life was claimed in 57 patients. Second therapies, ranging from cautery to repeat partial septal dermoplasty, were required in 15 patients during follow-up. Among the 67 patients, 31 (46%) had pulmonary arteriovenous malformation, 14 (21%) had gastrointestinal tract bleeding, 7 (10%) had symptomatic liver disease, and 5 (7%) had cerebral arteriovenous malformation. During the follow-up, 14 patients died of other complications of hereditary hemorrhagic telangiectasia (11 patients) and unrelated causes (3 patients).

CONCLUSION

Septal dermoplasty remains an effective way of reducing transfusion requirements in patients with hereditary hemorrhagic telangiectasia and subjectively improves their quality of life. The otolaryngologist caring for patients with hereditary hemorrhagic telangiectasia should be familiar with other organ involvement by hereditary hemorrhagic telangiectasia to prevent complications during surgery.

Enteroscopic evaluation of the gastrointestinal tract in symptomatic patients with hereditary hemorrhagic telangiectasia

OBJECTIVES

Hereditary hemorrhagic telangiectasia is an autosomal dominant disease in which 25% to 30% of patients will develop gastrointestinal bleeding from telangiectases. The extent of telangiectases has not been previously evaluated. This cross-sectional study compared the presence, number, and size of telangiectases in the stomach and duodenum to those in the jejunum using enteroscopy.

METHODS

At the Yale University Vascular Malformation Center, 30 consecutive, symptomatic adult patients with hereditary hemorrhagic telangiectasia were evaluated using a 220-cm-length enteroscope. The number and size of the telangiectases were documented in the esophagus, proximal and distal stomach, four parts of the duodenum, and every 20 cm in the jejunum. The indication for the procedure was recorded as anemia, gastrointestinal bleeding, or anemia out of proportion to epistaxis.

RESULTS

The results of 27 patients were analyzed. A total of 89% of patients had telangiectases in the first 60 cm of the jejunum. In individual patients, there was a strong correlation between the number of telangiectases in the stomach/duodenum when compared with the jejunum. In group analysis, the median number of telangiectases in the stomach and duodenum was significantly higher than in the jejunum (13 vs. 3; Wilcoxon signed rank test, P = 0.001). The presence of large (> or =5 mm) telangiectases in the stomach/duodenum did not necessarily indicate that there would be large telangiectases in the jejunum.

CONCLUSIONS

The presence and number of stomach and duodenal telangiectases correlated with the presence and number of jejunal ones. However, the occurrence of large proximal telangiectases was not associated with large distal ones.

Hereditary haemorrhagic telangiectasia: state of the art

Hereditary haemorrhagic teleangiectasia (HHT) or Rendu-Osler-Weber disease is a genetic autosomal-dominant disorder characterised by the presence of vascular telangiectases in mucocutaneous tissues, visceral organs and the Central Nervous System. Pulmonary arteriovenous malformations have a variable incidence rate ranging between 15-33%, and the safest treatment is transcatheter embolotherapy. Haemmorrhages from the gastrointestinal tract occur in 10-40% of patients with HHT localized in duodenum and colon and can be treated with endoscopy and laser coagulation, but this procedure is not efficacious for vascular anomalies in small intestine since this site cannot be easily reached. The prevalence of cerebrovascular malformations in hereditary haemorrhagic telangiectasia patients is 5-27%, and there are several types described including telangiectasias, cavernous angiomas, arteriovenous malformations, and aneurysms. Cerebrovascular malformations can be treated by: neurovascular surgery, embolization, and stereotactic radiosurgery, but the appropriate course of action for dealing with asymptomatic cerebrovascular malformations is still debated. The most common symptom in HHT patients is epistaxis, which can sometimes be so profuse that it requires multiple transfusions and iron supplementation. Nose bleeds begin before 10 years of age and become more severe in later decades. A multitude of different treatments are available, tailored to the severity of epistaxis. These include: hormonal therapy with oestrogens, application of fibrine tissue sealant, laser coagulation, embolization and septal dermoplasty using Saunder's technique. Aim of this study is to review diagnostic and therapeutic techniques, since continuous growth and danger of these arteriovenous malformations require early diagnosis, adequate treatment, prolonged follow-up and screening of the family.

Pulmonary arteriovenous malformations in children: outcomes of transcatheter embolotherapy

OBJECTIVE

To describe outcomes of transcatheter embolotherapy (TCE) in children with pulmonary arteriovenous malformations (PAVMs).

STUDY DESIGN

Chart and imaging review of all children (age </=18 years) treated for PAVMs by TCE at three hereditary hemorrhagic telangiectasia centers.

RESULTS

All 42 treated patients were included, with a mean age of 12 years (range, 4 to 18). Cyanosis was present in 25 of 42 patients (60%). Hemoptysis had occurred in 3 of 42 patients (7%) and neurologic complications (stroke, cerebral abscess) occurred in 8 patients (19%) before assessment. PAVMs were focal in 30 of 42 (71%) and diffuse in 12 of 42 (29%) patients. TCE was performed for 172 PAVMs and 35 diffuse regions (regional TCE). Follow-up was obtained in 38 of 42 (90%) patients (mean, 7 years). After TCE in patients with focal PAVMs, oxygenation improved significantly, with no further complications from the PAVMs. Reperfusion was noted in 23 of 153 (15%) PAVMs. Eighteen of 23 (78 %) of these were retreated, with documented aneurysmal involution in 10 of 13 (77%) patients. TCE complications included pleuritic chest pain (24% of sessions) and deployment complications (device paradoxical embolization or device misplacement) (3% of sessions, 1% of PAVMs), with no long-term complications.

CONCLUSIONS

PAVMs cause life-threatening complications in children; treatment with TCE is safe, with complication rates comparable to adult rates.

Micronester—A New Pushable Fibered Microcoil for Embolotherapy

A prototype 0.018 pushable fibered microcoil with an extended length of 14 cm was developed and used successfully for the first time to treat a patient with bilateral varicocele. This new coil provides immediate cross-sectional occlusion when "nested" into a densely packed coil mass. Potential uses of this new microcoil are discussed.

Angiography of hepatic vascular malformations associated with hereditary hemorrhagic telangiectasia

PURPOSE

To describe the angiographic features of hepatic involvement in hereditary hemorrhagic telangiectasia (HHT), particularly the presence of portovenous shunts.

METHODS

We reviewed the angiographic findings of seven patients with HHT. The patients comprised three women and four men with a mean age of 51 years.

RESULTS

Intrahepatic telangiectasias were found in all seven patients and shunts between three vascular channels were found in six of seven patients. In the four patients who had portovenous shunts combined with arterioportal shunts, the portovenous shunts were large. Three patients had no portovenous shunts. Two of these patients had arteriovenous shunts, and one had no shunt. The mean age (69 years) of the patients with portovenous shunts was older than those without portovenous shunts (26 years).

CONCLUSIONS

Hepatic vascular lesions in HHT are varied, ranging from telangiectasias to large shunts between three vascular channels. In an advanced stage of involvement, large portovenous shunts are present.

Diagnosis and management of gastrointestinal bleeding in patients with hereditary hemorrhagic telangiectasia

OBJECTIVE

Our aim was to report our experience with treating GI bleeding in patients with hereditary hemorrhagic telangiectasia (HHT).

METHODS

Consecutive patients with GI bleeding referred to the Yale University Vascular Malformation Center underwent clinical evaluation and endoscopy. Hb and blood transfusion requirements for 1 yr before and after evaluation were documented. Patients with a mean Hb <or= 8 mg/dl or blood transfusion requirements >or= 12 units packed red blood cells (PRBC)/yr were defined as patients with significant bleeding. Drug therapies, including ethinyl estradiol/norethindrone, danazol, and aminocaproic acid, were prescribed on an individual patient basis.

RESULTS

The study included 43 HHT patients with a mean age of 57 yr. Endoscopy revealed telangiectases in the esophagus (1/41), stomach (33/41), duodenum (33/41), jejunum (5/9), and colon (10/32). Patients with > 20 telangiectases visualized on esophagogastroduodenoscopy had a significantly lower mean Hb of 7.9, compared with 9.4 (p = 0.007), and a trend toward higher blood transfusion requirements. Non-HHT-related causes of GI bleeding were diagnosed in four patients. During a mean follow up of 18.9 months, the group of 40 patients with HHT-related bleeding had improvements in their mean Hb and blood transfusion requirements.

CONCLUSIONS

Some HHT patients with GI bleeding improve on drug therapies, but others fail. Transfusion-dependent GI bleeding is difficult to manage, and optimal management may include both medical and endoscopic treatments.

Vein of Galen technique for occluding the aneurysmal sac of pulmonary arteriovenous malformations

In seven of 255 consecutive patients (2.7%) who underwent pulmonary arteriovenous malformation (PAVM) embolization at our center between July 1, 1996, and July 1, 2000, the feeding artery was considered too short for safe occlusion with use of standard stainless-steel coils or detachable balloons. These patients were successfully treated with use of a modified vein of Galen technique similar to the one used for managing intracranial vein of Galen aneurysms. In this article, the authors report their experience with this technique in safely occluding the aneurysmal sacs of PAVMs in patients with short (<2 cm) feeding pulmonary arteries.

The 1st balloon valvuloplasty: an historical note

Balloon valvuloplasty (BV) is currently the treatment of choice for pulmonic stenosis in humans and dogs. Before permission was obtained to attempt the 1st BV in a child in 1982, the safety and efficacy of the procedure were tested in 1980 in an English Bulldog with spontaneous pulmonic stenosis. A fatal outcome would have caused indefinite postponement of BV in human patients, a procedure that currently benefits over 25,000 patients a year worldwide. This article describes the initial test procedure and its fortunate outcome in spite of unrecognized coronary anomalies in the bulldog. A small balloon was used in the test procedure, and fatal disruption of the anomalous left coronary artery (CA) did not occur as it has in several bulldogs since that time.

The use of cyanoacrylate adhesives in peripheral embolization

Although liquid adhesives or glue have been used as embolic agents for nearly three decades, experience with them outside of neurointerventional indications is generally limited. Cyanoacrylates are the main liquid adhesives used in the vascular system and have an important role in managing vascular abnormalities, especially arteriovenous malformations. Vascular occlusion results as these agents polymerize on exposure to the ions in blood. A description of the properties, biologic interactions, techniques of use, and indications for acrylic embolization in the peripheral circulation is especially pertinent at this time because of the recent approval of n-butyl cyanoacrylate by the United States Food and Drug Administration.

Transcatheter embolotherapy of maternal pulmonary arteriovenous malformations during pregnancy

STUDY OBJECTIVES

To determine if transcatheter embolotherapy is safe and effective for the treatment of pulmonary arteriovenous malformations during pregnancy.

DESIGN

Prospective study.

SETTING

Specialized hereditary hemorrhagic telangiectasia centers at Yale University School of Medicine and St. Michael's Hospital, University of Toronto.

PATIENTS

Seven pregnant women (age range, 24 to 34 years; gestational age range, 16 to 36 weeks) undergoing transcatheter embolotherapy.

INTERVENTIONS

Transcatheter embolotherapy in all patients.

MEASUREMENTS AND RESULTS

Thirteen pulmonary arteriovenous malformations in seven patients were embolized with detachable silicone balloons and/or stainless steel coils without incident. The estimated fetal radiation dose ranged from < 50 to 220 mrad. No complications of pulmonary arteriovenous malformations occurred in any of the patients after transcatheter embolotherapy. The mothers went on to deliver healthy babies in all cases.

CONCLUSIONS

Transcatheter embolotherapy of maternal pulmonary arteriovenous malformations performed by an experienced radiologist appears to be safe and effective after 16 weeks of gestational age.

Long-term outcome of embolotherapy and surgery for high-flow extremity arteriovenous malformations

PURPOSE

To assess the long-term efficacy of embolotherapy in combination with surgery for management of symptomatic high-flow arteriovenous malformations (HFAVMs) of the lower and upper extremities.

MATERIALS AND METHODS

Twenty consecutive patients with symptomatic high-flow lower extremity AVMs (LE-AVMs; n = 9) and upper extremity AVMs (UE-AVMs; n = 11) were treated from 1982 to 1999. All nine patients with LE-AVM had pain and seven had ulceration of the skin. All 11 patients with UE-AVM had debilitating pain, seven had weakness of the affected hand, and two had bony erosion. Embolization of the nidus beneath the site of maximum pain or ulceration was performed percutaneously from the femoral artery through coaxially placed microcatheters (n = 18) or surgical cutdown (n = 2). Cyanoacrylate (isobutyl or n-butyl) diluted with iophendylate or ethiodized oil was used in 19 of 20 patients.

RESULTS

Follow-up was completed in eight of nine patients with LE-AVM (mean, 8.6 y) and nine of 11 patients with UE-AVM (mean, 7.4 y) after treatment. One patient with localized LE-AVM was functioning well 13 years after embolotherapy and another was functioning well 16 years after undergoing three embolotherapy procedures and two skin grafts. Five of nine patients with LE-AVM required below-the-knee (n = 4) or above-the-knee (n = 1) amputation 1-6 years after technically and clinically successful embolotherapy. All three trifurcation arteries were diffusely involved in HFAVM in patients requiring amputation. Healing of the two amputation sites, involved by AVM at the knee, was excellent after preoperative geniculate artery embolotherapy. All 11 patients with UE-AVM experienced marked symptomatic improvement; seven after embolotherapy alone and the other four after resection of AVM. One complication of digital spasm was reversed by administration of nerve blocks.

CONCLUSIONS

LE-AVM with diffuse involvement of all three trifurcation arteries ultimately required amputation because of recurrence of symptoms after technically and clinically successful embolotherapy. Cyanoacrylate embolotherapy alone or in combination with surgical resection of the AVM provided excellent long-term palliation in patients with UE-AVM.

Pulmonary arteriovenous malformations: cerebral ischemia and neurologic manifestations

BACKGROUND

There is an increasingly recognized association between pulmonary arteriovenous malformations (PAVM) and cerebral ischemia, frequently attributed to paradoxical embolization. PAVM occur in 20 to 30% of the hereditary hemorrhagic telangiectasia (HHT) population.

OBJECTIVE

To evaluate the risk determinants for cerebral ischemia and neurologic manifestations in patients with PAVM.

METHODS

A retrospective cross-sectional study was performed on consecutive patients admitted between 1988 and 1992 for treatment of PAVM. The number of PAVM, feeding artery (FA) diameters, and aneurysmal sizes were determined by pulmonary angiography. Patients were categorized as having single or multiple PAVM with an FA diameter of > or = 3 mm. History, examination, and cerebral imaging studies were used to determine the prevalence of neurologic manifestations. Patients were defined as having cerebral paradoxical embolization if there was radiologic evidence of cortical infarction.

RESULTS

There were 75 cases: 26 single PAVM and 49 multiple PAVM. Cortical infarction was present in 14% of patients with single PAVM. Patients with multiple PAVM had a greater prevalence of any infarction (OR 3.2; 95% CI, 1.2 to 9.44, p = 0.030), cortical infarctions (OR 2.3; 95% CI, 0.58 to 9.2, p = 0.230), subcortical infarctions (OR 2.1; 95% CI, 0.58 to 7.95, p = 0.249), abscesses (OR 2.3; 95% CI, 0.46 to 11.94; p = 0.295), and seizures (OR 6.4, 95% CI 0.77 to 53.2, p = 0.054). Patients with multiple PAVM had markedly greater odds of having any clinical or radiologic evidence of cerebral ischemic involvement (OR 4.5; 95% CI, 1.47 to 14; p = 0.008).

CONCLUSION

There is a strong association between single PAVM and various neurologic manifestations. The prevalence is greater for patients with multiple PAVM, suggesting increased predisposition for paradoxical embolization with a greater number of malformations.

Liver disease in patients with hereditary hemorrhagic telangiectasia

BACKGROUND

Hereditary hemorrhagic telangiectasia, or Rendu-Osler-Weber disease, is an autosomal dominant disorder characterized by angiodysplastic lesions (telangiectases and arteriovenous malformations) that affect many organs. Liver involvement in patients with this disease has not been fully characterized.

METHODS

We studied the clinical findings and results of hemodynamic, angiographic, and imaging studies in 19 patients with hereditary hemorrhagic telangiectasia and symptomatic liver involvement.

RESULTS

We evaluated 14 women and 5 men who ranged in age from 34 to 74 years. All but one of the patients had a hyperdynamic circulation (cardiac index, 4.2 to 7.3 liters per minute per square meter of body-surface area). In eight patients, the clinical findings were consistent with the presence of high-output heart failure. The cardiac index and pulmonary-capillary wedge pressure were elevated in the six patients in whom these measurements were performed. After a median period of 24 months, the condition of three of the eight patients had improved, four were in stable condition with medical therapy, and one had died. Six patients had manifestations of portal hypertension such as ascites or variceal bleeding. The hepatic sinusoidal pressure was elevated in the four patients in whom it was measured. After a median period of 19 months, the condition of two of the six patients had improved, and the other four had died. Five patients had manifestations of biliary disease, such as an elevated alkaline phosphatase level and abnormalities on bile duct imaging. After a median period of 30 months, the condition of two of the five had improved, the condition of one was unchanged, heart failure had developed in one, and one had died after an unsuccessful attempt at liver transplantation.

CONCLUSIONS

In patients with hereditary hemorrhagic telangiectasia and symptomatic liver-involvement, the typical clinical presentations include high-output heart failure, portal hypertension, and biliary disease.

Embolotherapy in the bronchial and pulmonary circulations

This two-part article first discusses the role of bronchial artery transcatheter embolotherapy in the management of patients with hemoptysis. Following this discussion, the authors review pulmonary arteriovenous malformations, their embolization, follow-up protocols, and outcome criteria as currently practiced at the authors' Vascular Malformation Center.

Diffuse pulmonary arteriovenous malformations: characteristics and prognosis

OBJECTIVE

To study the clinical characteristics and prognosis of patients with diffuse pulmonary arteriovenous malformations (AVMs).

DESIGN

Retrospective chart review of all patients (n = 16) with diffuse pulmonary AVMs seen at Yale New Haven Hospital, Johns Hopkins Hospital, and St. Michael's Hospital. Up-to-date follow-up information was obtained in all living patients.

RESULTS

All patients were severely hypoxic. Neurologic complications (stroke or brain abscess) had occurred in 70% of patients by the time of diagnosis. During the follow-up period (mean, 6 years), three patients died and two others developed new neurologic complications. One of the deaths occurred perioperatively during lung transplantation. All patients underwent transcatheter embolotherapy of any large pulmonary AVMs. A selected group underwent pulmonary flow redistribution, a novel technique. Oxygenation did not improve significantly with embolotherapy of the larger AVMs, but there was a small significant improvement in those patients who underwent pulmonary flow redistribution. The majority (85%) of the living patients are currently working or studying full-time.

CONCLUSIONS

Patients with diffuse pulmonary AVMs are at increased risk of neurologic complications. Transcatheter embolotherapy does not significantly improve the profound hypoxia, but it may reduce the risk of neurologic complications. Antibiotic prophylaxis is recommended for bacteremic procedures to prevent brain abscess. These patients can live for many years and lead productive lives. We do not recommend lung transplantation because survival with disease is difficult to predict and we have observed a perioperative transplant death.

Identification of hereditary hemorrhagic telangiectasia type 1 in newborns by protein expression and mutation analysis of endoglin

Hereditary hemorrhagic telangiectasia (HHT) is a dominantly inherited vascular disorder that is heterogeneous in terms of age of onset and clinical manifestations. Endoglin is the gene mutated in HHT1, which is associated with a higher prevalence of pulmonary arteriovenous malformations than HHT2, where ALK-1 is the mutated gene. Endoglin is constitutively expressed on endothelial cells and inducible on peripheral blood activated monocytes so that protein levels can be measured by metabolic labeling and immunoprecipitation. We report the analysis of umbilical vein endothelial cells in 28 newborns from 24 families with a clinical diagnosis of HHT. Reduced levels of endoglin were observed in umbilical vein endothelial cells in 15/28 subjects and in activated monocytes of all clinically affected relatives tested, suggesting that these individuals had HHT1. No mutant protein was expressed at the cell surface in any of these cases, and a transient intracellular species was seen in samples of only two families, supporting a haploinsufficiency model. Quantitative multiplex PCR fragment analysis was established for the endoglin gene and revealed six mutations that were confirmed by automated DNA sequencing. An additional 10 mutations were identified in newborns by sequencing all exons. Of the 16 mutations, 10 were novel, three had been independently identified in related families, and three were previously known. Our data confirm that endoglin levels correlate with the presence or absence of mutation in HHT1 families, allowing the early identification of affected newborns that should be screened clinically to avoid serious complications of this disorder, such as cerebral arteriovenous malformations.

Embolotherapy of pulmonary arteriovenous malformations with detachable balloons: long-term durability and efficacy

PURPOSE

To determine long-term durability and efficacy of pulmonary arteriovenous malformation (PAVM) embolotherapy using detachable gold valve latex (GVB) and silicone balloons (DSB).

MATERIALS AND METHODS

Eighty-two patients were treated with either GVBs or DSBs between 1991 and 1996. Complete follow-up, consisting of chest radiography or high-resolution chest computed tomography, was obtained in each patient between 1996 and 1998. The PAVM was considered cured if the aneurysmal portion was involuted with or without a small residual scar.

RESULTS

Eighty-two of the 85 DSBs (96%) were inflated 2-4 years later, and none of the 56 GVBs remained inflated 1-3 years after placement. Despite early deflation of the GVB (91% at 1 month), only one PAVM persisted in both groups (DSB and GVB). Clinical and radiographic involution of the PAVMs was complete in all patients except one, who was easily re-treated. No migration of DSBs or GVBs to the systemic circulation occurred.

CONCLUSIONS

DSBs and GVBs provide immediate cross-sectional occlusion of PAVM and are equally effective in "curing" the PAVM. The DSBs remain inflated 2-4 years after placement provided isoosmotic contrast material is used to inflate them and volume recommendations are adhered to. No early or late migration of the DSB or GVB occurs, provided they are securely placed.