Management of vascular and lymphovenous malformations

Perhaps the most important event in relation to the vascular and lymphovenous group of malformations has been the development of a classification which is useful to physicians, patients, and parents. The broad classification consists of hemangiomas and vascular malformations; the latter group is further subdivided into venous, arteriovenous, and lymphovenous malformations [5, 11]. Hemangiomas are present at or just after birth in 40% of infants. They grow rapidly and involute slowly; there is increased endothelial cell activity. Venous malformations are present at birth in 70% of cases; they grow with the child and have a normal rate of endothelial cell turnover. Lymphovenous malformations occur at an early age and may or may not resolve. Arteriovenous malformations are usually progressive. The treatment is a combination of embolization and surgery.      

Vaskuläre Malformationen

Vascular malformations are localized defects of vascular morphogenesis. Contrary to infantile hemangiomas, which are vascular tumors and go through a phase of proliferation followed by regression, they never regress. They grow commensurately with the patient and may become symptomatic at adolescence or in young adults. Trigger effects, such as trauma or hormonal influences may stimulate growth and symptoms. Clinical indications for vascular malformations at the time of birth are bluish discolorations of the skin (e.g. venous malformations) or cherry-red spots (e.g. capillary malformations or combined malformations). Children may show signs of asymmetric increased growth of extremities or increased girth on the affected side, or pain resulting from coagulation effects in truncular (thrombosis of the pelvic veins in atresia of caval veins) or extratruncular (thrombophlebitis in venous malformations) malformations. A buzzing sensation during light contact in combination with brownish skin discolorations (Stewart-Bluefarb syndrome), localized enhanced skin temperature and dilated subcutaneous draining veins are signs of a high-flow arteriovenous malformation (AVM). Large AVMs may lead to high-output cardiac failure in children and young adults. Large VMs may show localized intravascular coagulation with high D-dimer levels and low platelet counts. After surgery, pregnancy or trauma this condition may deteriorate to disseminated intravascular coagulation. Typical consequences of enduring VMs are venous insufficiency or severe arthrosis (e.g. due to hemarthrosis) and recurrent erysipelas with lymphatic malformations (LM), which can severely reduce the quality of life.     

Congenital vascular lesions: clinical application of a new classification

Two hundred and ninety-seven patients with 375 pediatric vascular lesions were followed from 1967 to 1981. By history and physical examination, 96% of childhood vascular lesions can be classified as hemangiomas or malformations. Hemangiomas are often not present at birth (40%), but make their appearance during the first month. A proliferative phase, lasting an average of 3 months, is followed by a slow, but eventually complete involution. A "perfect" cosmetic result is more likely when involution is complete before age 6. Malformations are always present at birth, their growth is commensurate with the patient's, and they never involute. Analysis of clinical characteristics fails to identify a subgroup of hemangiomas destined for early involution.     

A case report of arteriovenous malformation of the tongue: vascular anatomy and note for transarterial embolization

Arteriovenous malformation (AVM) of the tongue is a rare lesion of the cranio-facial vascular anomaly. Decision making concerning the vascular anomaly is not established because there are complex classifications of diagnosis and many treatment options. We report a case of AVM of the tongue, and review vascular anatomy and knowledge for treating this lesion. A 50-year-old man presented with dysarthria, sleep apnea and snoring because of a mass lesion of his sublingual region that had become larger over a two-year period. Neuroradiological examination revealed lingual arteriovenous fistula (AVF) associated with AVM of the tongue base. We performed transfemoral transarterial embolization via both lingual arteries using Polyvinyl alcohol particles and Eudragit-E as non-adhesive glue material. Final angiograms after embolization revealed a small residual nidus fed by the right facial artery mental branch, but shunt flow was markedly reduced. This vascular malformation was removed after a day of TAE (transarterial embolization). The patients symptom was improved and relapse has not been confirmed though 18 months have passed since the surgery. Using classification proposed by Mulliken and Glowacki, vascular anomalies are divided into two groups: hemangiomas and vascular malformations (AVM/F, arterial, venous, capillary, lymphatic and combined). AVM/F is classified into high flow malformation. TAE is useful for high flow malformation and can be used as the sole treatment or as an adjunct. Treatment should be to eradicate nidus or fistula completely, which is the fundamental abnormality because even the smallest residual nidus will expand to cause recurrence. The treatment of Cranio-facial AVM's requires rigorous differential diagnosis and appropriate management. Inadequate treatment is thought to contribute to collateral flow and disease progression in advanced AVM, making further management difficult.     

Congenital arteriovenous malformations: A follow-up of treatment

Due to the rarity of arteriovenous malformations (AVMs), there is a paucity of information on the outcomes of various treatments. Presently, the mainstays of treatment of an AVM are embolization, surgical excision or a combination of both.A retrospective study of 26 patients with AVMs treated at The Hospital for Sick Children, Toronto, Ontario between 1985 and 1995 was performed. The treatment strategies and patient outcomes were compared in terms of efficacy, complications and the response of patients and their families to their overall treatment.The overall findings showed that embolization alone was effective in controlling symptoms, but may be associated with an increased AVM size. A partial excision of an AVM does not appear to exacerbate recurrence, as has been previously reported. In fact, even after what appears to be a complete excision of the AVM, recurrence may still occur. Complications from a surgical excision of the AVM are more frequent but less devastating than complications from embolization of the lesion. The overall patient or parent satisfaction with treatment was high with respect to improvement in outcome.It is expected that with an increasing understanding of vascular malformations, and the evolution of interventional radiological techniques, complications will decrease and results as a whole will improve.     

先天性动静脉畸形的新分期与治疗选择

目的 探讨颅外先天性动静脉畸形的临床分类方法及相应的治疗选择。方法 通过对6年内83个病例的临床表现、影像诊断、介入治疗、外科手术治疗结果的系统随访和分析，探讨该疾病的临床分期，解剖区域分布规律、各分期的治疗选择、不同介入材料对复发率的影响、进行未痊愈病例原因分析。结果 根据临床表现可将先天性动静脉畸形分为静止期、扩张期和失代偿期，前者以单纯介入治疗为主，后者以手术治疗为主，介入治疗的方法与材料选择对复发率等有重要影响，未栓塞病例的手术治疗要求依据DSA和CTA完整切除和具有丰富血供的组织移植重建。结论 对先天性动静脉畸形的临床分期和合理的治疗方案设计将使此类疑难病例的治疗大大易化。     

In vitro characteristics of endothelium from hemangiomas and vascular malformations

Hemangiomas are vascular tumors characterized by rapid growth, increased endothelial turnover, and increased numbers of mast cells. Vascular malformations grow commensurately with the patient or expand secondary to hemodynamic alteration and are characterized by a normal endothelial cell cycle and normal numbers of mast cells. Operative specimens of vascular birthmarks were categorized as hemangiomas or malformations based on clinical history, light microscopic examination, and mast cell quantitation. The specimens were cultured in tumor-conditioned medium and plasma clot culture. Capillary endothelium derived from hemangioma specimens formed capillary tubes in tissue culture--"angiogenesis in vitro." Capillary endothelium from malformations was difficult to culture and was not observed to form tubules. Hemangioma specimens demonstrated rapid outgrowth of tubular structures from plasma clot cultures, whereas malformation tissue did not produce such outgrowth. These results indicate that hemangioma endothelium grows preferentially in culture in comparison with endothelium from vascular malformations. It suggests a biologic difference, which correlates with our previously proposed classification.     

Management of patients with hemangiomas and arteriovenous malformations

Hemangiomas and AVMs are distinct congenital, benign, vascular lesions. Differentiation between the two is important because AVMs are amenable to embolization techniques and because patients with hemangiomas can be told they have a better prognosis than those with AVMs. A major error of management is to ligate the arterial blood supply to an AVM proximally, as the lesion will continue to grow, more collateral vessels will develop, and future angioaccess for purposes of evaluation or embolization will be denied. With care and prudence, many of these lesions can be successfully excised, or at least managed, so that the effect of these sometimes devastating lesions can be ameliorated.     

Pulmonary Arterial Hypertension in a Patient With Hereditary Hemorrhagic Telangiectasia

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant disorder characterized by the triad of epistaxis, telangiectasia and vascular malformations. Pulmonary vascular complications associated with this disease include pulmonary arteriovenous malformations (AVM) and, less frequently, pulmonary hypertension (PH).We report the case of a patient who presented multiple pulmonary AVM and PH probably due to HHT. Embolization was carried out on one of the AVM and the patient received specific pulmonary arterial hypertension treatment with an endothelin receptor antagonist. We also described the patient's functional and hemodynamic improvement after almost 3 years of follow-up.     

Delayed presentation of an arteriovenous malformation after cerebellar hemangioblastoma resection—Case report

IntroductionHaemangioblastoma has been uncommonly reported to occur in coexistence either temporally or spatially with the development of an arteriovenous malformations (AVM). We present a case of a delayed AVM following haemangioblastoma resection.Presentation of case44 year old female initially presented with a several week history of headaches, vertigo and nausea and emesis and was found to have a cystic lesion with a solid enhancing component on Magnetic Resonance Imaging (MRI) in the superior aspect of the vermis. She underwent gross total resection and final pathology was consistent with WHO grade I haemangioblastoma. One year later, patient re-presented with headaches, dizziness and left trochlear nerve palsy with rotary nystagmus. Imaging revealed a left posterior tentorial paramedian cerebellar vascular nidus with venous drainage into the left transverses sinus suspicious for arteriovenous malformation. She underwent gross total resection of the lesion. Final pathology confirmed the diagnosis of an arteriovenous malformation.DiscussionRecent research supports both haemangioblastoma and AVM are of embryologic origin but require later genetic alterations to develop into symptomatic lesions. It is unclear in our case if the AVM was present at the time of the initial haemangioblastoma resection or developed de novo after tumor resection. However, given the short time between tumor resection and presentation of AVM, de novo AVM although possible, appears less likely.ConclusionAVM and haemangioblastoma rarely presents together either temporally or spatially. We present a case of a delayed AVM following haemangioblastoma resection. More research is needed to elucidate the rare intermixture of these lesions.     

Radiosurgery for Intracranial Arteriovenous Malformations in Children

Background: The objective of this retrospective study is to determine the value of radiosurgery in the management of arteriovenous malformations (AVM) in the pediatric age group. Methods: From January 1994 through January 1999, thirty-one children with arteriovenous malformations (AVMs) were treated with radiosurgery. All patients were treated on an outpatient basis at the same institution by the same team. The Leksell Gamma Knife unit was used. Workup included angiography, MRI, and MRA. Follow-up ranged from 7 months to 67 months, with a median of 33 months. Minimum doses of radiation, depending on the size of the lesion, ranged from 20 Gy to 25 Gy. Treatment volumes for all the vascular malformations ranged from 0.6 cc to 17 cc with a mean volume of 4.7 cc. The mean number of isocenters was 4.8. Results: Total obliteration of AVM nidus was obtained in 22 of 31 (71%) patients, while 9 patients had partial obliteration. Stabilization of the benign lesions was obtained in all the patients treated. None had rebleeding after the procedure and, as of this writing, no patient required retreatment. Conclusion: Radiosurgery is an effective noninvasive and safe therapeutic modality for the management of vascular malformations independent of location, size, or grade.     

Verrucous malformations: their presentation and management

Verrucous hemangiomas are a distinct subset of vascular malformations that have not been described extensively in the plastic surgery literature. They are characterized by reactive epidermal acanthosis, papillomatosis, hyperkeratosis, and extension into the subcutaneous tissues. In response to injury, infection, or subtotal resection, they enlarge and become increasingly keratotic. In light of contemporary definitions of hemangiomas and malformations, the authors recommended that these lesions be renamed verrucous malformations. The authors review their evaluation and treatment of 6 patients with this lesion and offer an algorithm that emphasizes excision over ablative therapy. Of the 6 patients, 3 patients had failed either cryotherapy or laser removal by a nonsurgeon, with a consequent increase in lesion size and discomfort. The lesions were all subsequently excised. Because of the size and location of the verrucous malformations, staged removal was required in 3 patients. Patients have been followed for as long as 7 years. A single recurrence was controlled with reexcision. Excision of verrucous malformations, rather than laser ablation or cryosurgery, is supported by the authors' favorable results.     

Klassifikation und medizinische Therapie von kongenitalen vaskulären Malformationen

Congenital vascular malformations are the result of an abnormal development during embryogenesis. It is important to distinguish these anomalies from vascular tumors, e.g. infantile hemangioma, as they are two completely different types of lesion with different clinical courses and treatment options. With the modified Hamburg classification vascular malformations are categorized based on the predominant vessel involved (e.g. arterial, arteriovenous, venous, capillary, lymphatic or combined). Additionally, each lesion can be defined as extratruncular or truncular based on the embryological origin of the defect. This is an important distinction as it provides an indication of prognosis and therapeutic options. The hemodynamic characteristics of vascular malformations are defined as low-flow or high-flow according to the International Society for the Study of Vascular Anomalies (ISSVA) classification. In contrast to infantile vascular tumors (hemangiomas) there are no medicinal options to treat vascular malformations. The focus of conservative management is relief of symptoms and prevention of complications. In most cases compression therapy is the single most important measure.     

Pathogenesis and genetics of vascular anomalies

Vascular anomalies, divided into vascular tumors and vascular malformations, are localized defects of angiogenesis. Hemangiomas appear soon after birth, grow quickly, and then spontaneously, but slowly, disappear. In contrast, vascular malformations are congenital defects of vascular development that grow proportionately with the child. Most vascular anomalies are considered non-hereditary. However, due to detailed analysis inherited forms have been observed, which has led to identify mutations in three genes causing familial vascular malformations: in the angiopoietin receptor TIE2 in mucocutaneous venous malformations (VMCM), in glomulin in glomuvenous malformations (GVM) and in RASA1 in the newly recognized phenotype capillary malformation-arteriovenous malformation (CM-AVM). Identification of the causative genes has permitted more precise diagnosis and differential diagnosis, evaluation of phenotypic variability among patients with a proven mutation, study of used treatments in more homogeneous patient groups, and elucidation of the etiopathogenic mechanisms behind vascular malformations. Further studies are needed to unravel the role of genetic variations in the various vascular malformations and to unravel the precise molecular mechanisms that lead to development of these vascular lesions. This should provide development of new-targeted therapies.     

Venous malformation serving as the draining vein of an adjoining arteriovenous malformation. Case report and review of the literature

BACKGROUND: Widely accepted pathologic classification of venous malformations includes discrete venous, arteriovenous, capillary, and cavernous malformations, each with distinct pathological criteria for definition. Several authors have described mixed or transitional vascular malformations with pathological features of more than one type of malformation within the same lesion. We present a rare case of a venous malformation associated with an arteriovenous malformation (AVM). CASE DESCRIPTION: A 37-year-old woman presented with a loss of consciousness. Computed tomography showed an enlarged vein running along the lateral wall of the right lateral ventricle. A cerebral angiogram demonstrated an AVM and a venous malformation in the right hemisphere; the AVM and the venous malformation were located in proximity to each other with the AVM using the venous malformation as its draining vein. In this case, where an AVM used the venous malformation as the draining vein, only the AVM was treated by proton-beam radiosurgery. Follow-up magnetic resonance angiography demonstrated complete obliteration of the AVM with the venous malformation remaining unchanged. CONCLUSION: Arteriovenous shunting would have disturbed venous drainage resulting in the development of the venous malformation. Thus, in addition to demonstrating a rare coexistence of AVM and venous malformation, this case also offers a new insight into the pathogenesis of these vascular malformations.     

增殖细胞核抗原在血管瘤及血管畸形组织中的表达

目的了解血管瘤的不同形态学类型和同一类型不同时期的内皮细胞增殖情况。方法采用免疫组织化学方法对41例不同形态学类型的血管瘤标本进行了增殖细咆核抗原(PCNA)的检测和比较,其中包括婴幼儿期血管瘤标本29例及成人期际本12例。结果增生期草霉状血管瘤、增生期混合血管瘤以及部分婴幼儿海绵状血管瘤检测结果为阳性,提示其内皮细胞处于增殖状态,其余均为阴性,经统计学处理,不同类型的婴幼儿增生期血管瘤间的 PCNA 标记指数无显著差异,与消退期婴幼儿血管瘤及各类成人血管瘤有显著差别。结论 PCNA 的表达对血管瘤的分类、诊断及治疗选择都有意义。     

Intracranial capillary hemangioma: case report and review of the literature

BACKGROUND: Capillary hemangiomas are benign vascular lesions that commonly present at birth or in early infancy on the face, scalp, back, or chest. The authors present an exceedingly rare case of an intracranial capillary hemangioma arising in an adult. Only 4 biopsy-proven cases have been reported in the pediatric population previous to this case report. CASE DESCRIPTION: A 31-year-old pregnant woman presented at 38 weeks of gestation with severe headaches, nausea, and vomiting. Imaging revealed an extra-axial mass lesion arising from the tentorium with both supra- and infratentorial components. The patient underwent a resection of her tumor, which was diagnosed as a capillary hemangioma by histopathologic examination. The patient required 2 further resections after the lesion exhibited a rapid regrowth from residual tumor in the left transverse sinus. The patient has remained free of disease 41 months out from her third surgery. CONCLUSIONS: Intracranial capillary hemangiomas are exceedingly rare entities, with a capability for rapid growth. When gross total resection cannot be achieved, these patients should be observed closely, and the use of adjuvant radiotherapy should be considered.     

Natural history of intracranial vascular malformations: a review

It is difficult to assess the natural history of intracranial vascular malformations because they are varied in nature, they are frequently silent clinically, they are often treated when they are discovered, and untreated lesions are not often followed in an organized way. Capillary telangiectasias are usually occult lesions of no clinical significance. Cavernous hemangiomas may cause seizures and may bleed, but the approximate yearly risks of bleeding and of death have not been determined. Venous angiomas seldom cause symptoms, with the exception that those in the cerebellum seem to have a propensity to bleed. Intracranial dural arteriovenous malformations (AVMs) may bleed and may cause brain injury if there is insufficient outflow into a dural venous sinus. The dural AVMs that drain into the cavernous sinus have a more benign course than those that drain into the transverse or sigmoid sinus. The aneurysm of the vein of Galen presents a different clinical picture and threat to health according to whether the patient is a neonate, an infant, or an older child. The AVM of the brain encountered in the adult usually presents with hemorrhage or seizures. An unruptured AVM has approximately a 2 to 3% risk of bleeding per year, with about a 1% risk of death per year. The mortality rate of the first hemorrhage is about 10%. Among the survivors, there is about a 6% chance of rebleeding during the 1st year and then approximately a 2 to 3% risk of bleeding per year subsequently. The mortality rate associated with a second hemorrhage is about 13%, and for subsequent hemorrhages the mortality is roughly 20%.     

增殖细胞核抗原在血管瘤及血管畸形组织中的表达

了解血管瘤的不形态学类和同一类不同时期的内皮细胞增殖情况。方法采用免疫组织化学方法对４１例不同形态学类型的血管瘤标本进行了增殖细胞核抗原的检测和比较。其中包括婴幼儿期血管瘤标本２９例及成人期标本１２例。结论ＰＣＮＡ的表达对血管瘤的分类，诊断及治疗选择都有意义。