What Are Vascular Malformations?

Previously, the classification and nomenclature of hemangiomas and vascular malformations has been ambiguous. Most are collectively referred to as hemangiomas or lymphangiomas, and are named mainly based on the morphology of the lesion. For example, hemangiomas include capillary hemangiomas, cavernous hemangiomas, and hemangiomas; lymphangiomas also include capillary, cavernous, and cystic types. Because patients with hemangioma and vascular malformations can be seen in different clinical departments, even the same lesion can be named differently. If there is a department, the wine stain is called a erythema nevus. In 1982, Mulliken and Gloweki proposed a new classification from the aspects of cell biology and pathology, and clearly distinguished between tumors and malformations. After this, Jackson (1993), Waner and Suen (1995) supplemented and improved on the basis of Mulliken et al., And proposed an updated classification. In 2002, at the National Symposium on Oral and Maxillofacial Hemangioma Treatment and Research Held by the Professional Committee of Oral and Maxillofacial Surgery of Chinese Stomatological Association, the participants agreed that the concept, classification and naming of hemangiomas and vascular malformations should be redefined , And unanimously recommend the classification and naming of Waner and Suen:

Basic Information

Classification and nomenclature of vascular malformations

Vascular malformation nomenclature

Previously, the classification and nomenclature of hemangiomas and vascular malformations has been ambiguous. Most are collectively referred to as hemangiomas or lymphangiomas, and are named mainly based on the morphology of the lesion. For example, hemangiomas include capillary hemangiomas, cavernous hemangiomas, and hemangiomas; lymphangiomas also include capillary, cavernous, and cystic types. Because patients with hemangioma and vascular malformations can be seen in different clinical departments, even the same lesion can be named differently. If there is a department, the wine stain is called a erythema nevus. In 1982, Mulliken and Gloweki proposed a new classification from the aspects of cell biology and pathology, and clearly distinguished between tumors and malformations. After this, Jackson (1993), Waner and Suen (1995) supplemented and improved on the basis of Mulliken et al., And proposed an updated classification. In 2002, at the National Symposium on Oral and Maxillofacial Hemangioma Treatment and Research Held by the Professional Committee of Oral and Maxillofacial Surgery of Chinese Stomatological Association, the participants agreed that the concept, classification and nomenclature of hemangiomas and vascular malformations should be redefined , And unanimously recommend the classification and naming of Waner and Suen:

1. Hemangiooma.

2. Vascular malformation.

(1) Venous malformation: There are two types of microvenous malformations and microvenous malformations.

(2) Venous malformation.

(3) arteriovenous malformation.

(4) Lymphatic malformation: There are two types of lymphatic malformation.

(5) mixed malformation: venous-lymphatic malformation and venous-venular malformation type 2.

Vascular malformations

If the above classification is compared with the old classification method, it has the following characteristics:

1. Among tumorous lesions, only hemangiomas are true tumors, others are vascular malformations. Strawberry-like hemangioma in the old classification mostly belongs to this category.

2. From the perspective of histopathology, microvenous malformations have been increased. The diameter of the microvenous vein should be smaller than that of the capillary vein (50-200um). The clinical port-wine stain (PWS) should be a microvenous malformation rather than a capillary type. Venous malformations should be cavernous hemangioma in the old classification.

3 The microcapsule type of lymphatic malformations seems to include the capillary and cavernous lymphangiomas in the old classification; the large cystic type is equivalent to the cystic or cystic hydromas in the old classification.

4 Venous-lymphatic malformations in the mixed type should refer to the so-called cavernous lymphangioma in the old classification and clinically common. Microvenous-lymphatic malformations refer to capillary lymphangioma or hemangiolymphangioma in the old classification.

Hemangiomas

Pathogenesis of vascular malformations

Hemangiomas are more common at birth (about 1/3) or shortly after birth (within 1 month). It originates from residual embryonic hemangioblasts. TCM believes that it is related to fetal fever and blood fever, which is caused by dysfunction of the heart and liver.

The histopathological characteristics of hemangiomas are rich in proliferative vascular endothelial cells, with hemangiopoiesis and the accumulation of mast cells.

Vascular malformation

Hemangiomas that occur in the oral and maxillofacial region account for about 60% of systemic hemangiomas, most of which occur in the skin and subcutaneous tissue of the face and neck, and very few are found in the oral mucosa. Hemangiomas in the deep and jaw bones are currently considered to be vascular malformations.

The biological behavior of hemangiomas is to resolve spontaneously. The course of the disease can be divided into three stages: a proliferative phase, a receding phase, and a receding completion phase.

Clinical manifestations of vascular malformations

The proliferative phase initially manifested as telangiectasias, surrounded by halo-like white areas; it quickly turned into erythema and rose above the skin, with unevenness resembling the shape of a poplar (grass). With the baby's first growth and development period, it grows rapidly after about 4 weeks, and this is often the most urgent period for parents to seek treatment. If it grows on the face, it can not only cause deformities, but also affect motor functions, such as closing eyes and mouth movements; in some cases, secondary infections can occur in the tumor. Rapid proliferation can also be accompanied by the second growth and development period of the baby, that is, 4 to 5 months. It usually enters the period of static subsidence after 1 year. The resolution is slow, the lesions change from bright red to dark purple, brown, and the skin can be piebald. According to statistics, about 50% to 60% of patients have completely subsided within 5 years; 75% have completely subsided within 7 years; about 10% to 30% of patients continue to resolve to about 10 years of age, but may be incomplete. Therefore, the so-called complete period of subsidence is generally 10 to 12 years old. After a large area of hemangioma has completely subsided, there can be signs of local pigmentation, shallow scars, skin atrophy and sagging.

Vascular malformation

Vascular malformation venous malformation

The old classification is called cavernous hemangioma, which is composed of countless blood sinuses lined with endothelial cells. Blood sinuses vary in size and shape, such as sponge structures. Sinus blood coagulates to form a thrombus, which can be calcified into vein stones.

Venous malformations occur on the cheeks, neck, eyelids, lips, tongue, or bottom of the mouth. The location is different. If the location is deep, the skin or mucous membrane is normal; superficial lesions are blue or purple. The boundaries are not very clear. The ridges are soft and can be compressed, sometimes reaching vein stones. When the head is in a low position, the lesion area becomes congested and swollen. After returning to the normal position, the swelling will also shrink and return to its original state.

Most of the venous malformations are not found at birth, and some of them are noticed in early childhood or even after adulthood.

When the size of the venous malformation is small, there are generally no symptoms. If it continues to develop and grow up, it can cause facial deformity, lip, tongue and other deformities and dysfunction. If an infection occurs, it can cause pain, swelling, ulcers on the skin or mucous membranes, and the risk of bleeding.

Vascular malformation

The common wine stain. Occurs in the facial skin, often distributed along the trigeminal nerve distribution area. Less oral mucosa. It is bright red or purplish red, flat with the skin surface and clear perimeter. Its shape is irregular and varies in size. From small spots to several centimeters, large ones can extend to one side of the face or cross the midline to the opposite side. The finger is pressed against the lesion, and the surface color fades. After the pressure is relieved, the blood immediately fills the lesion area again, and the original size and color are restored.

The so-called midline microvenous malformations are mainly lesions located in the midline area, the most common in the neck, and can occur in the forehead, between the eyebrows, and in the middle part of the upper lip. Unlike wine stains, it fades on its own.

Vascular malformation arteriovenous malformation

The old classification is called diffuse hemangioma or grape hemangioma. It is a kind of vascular malformation with curved, very irregular and pulsatile gyrus. It is mainly formed by the direct anastomosis of arteries and veins with significantly dilated vascular walls, so it is also called congenital arteriovenous malformation.

Arteriovenous malformations are more common in adults and rare in young children. It usually occurs in the temporal or subscalp tissue where the superficial temporal artery is located. The lesions are rosary-shaped and the surface temperature is higher than normal skin. Patients may feel the pulsation on their own; there is a tremor on percussion and a hair-like noise on auscultation. When all the blood-supplying arteries are closed, the pulsation and noise in the lesion area disappear. Tumors can erode the bone of the base, can also penetrate into the skin, making it thinner and even necrotizing and bleeding.

Arteriovenous malformations can coexist with other vascular malformations.

Vascular malformation

It is formed by abnormal lymphatic development. Common in children and youth. Occurs on the tongue, lips, cheeks and neck. According to its clinical characteristics and tissue structure, it can be divided into two types: microcapsule type and macrocapsule type.

(1) Microcapsule type: Including the capillary and cavernous lymphangiomas in the old classification. Dilated by endothelial-lined lymphatic vessels. The lymphatic vessels are extremely dilated and curved, forming a multilocular cyst, which is rather spongy. Lymphatic vessels are filled with lymph fluid. Isolated or multiple scattered small circular cystic nodular or punctate lesions on the skin or mucous membrane, colorless, soft, generally non-compressive, and the boundaries of the lesions are unclear. Lymphatic malformations of the oral mucosa sometimes coexist with microvenous malformations, with yellow and red vesicular protrusions, called lymphangiomas.

Occurred in the lips, under the jaw and cheeks, sometimes the affected area can be significantly hypertrophy. Those who occur in the tongue often present with giant tongue disease, causing jaw deformities, occlusal teeth, anti-occlusal teeth, tooth displacement, and occlusal disorders. The surface of the tongue mucosa is rough, nodular or vein-like, with yellow vesicles. On the basis of long-term chronic inflammation, the tongue can harden.

(2) Macrocystic type: In the old classification, it is called cystic type or cystic hydromas. It mainly occurs in the supraclavicular region of the neck, but also in the submandibular region and the upper neck. Generally, it is a multi-chambered cyst, spaced from each other, and contains transparent, pale yellow watery liquid. The lesions vary in size, the surface skin color is normal, and it is full, and the percussion is soft and fluctuating. Unlike deep hemangiomas, the postural movement test is negative, but sometimes the light transmission test is positive.

5. Mixed vascular malformations When there are more than one type of vascular malformations, they can be called mixed vascular malformations. For example, the aforementioned microvenous malformations and lymphoid microcapsules coexist; arteriovenous malformations are associated with localized microvenous malformations; naturally, venous malformations can also coexist with large cystic malformations of lymphatic vessels.

Diagnosis of vascular malformations and vascular malformations

The diagnosis of superficial hemangiomas or vascular malformations is not difficult. Deeper hemangiomas or vascular malformations should be determined by postural movement test and puncture. For arteriovenous malformations, venous malformations in deep tissues, macrocystic lymphatic malformations, etc., in order to determine the location, size, scope and anastomosis, ultrasound, angiography, tumor angiography or magnetic resonance angiogenesis can be used. Imaging (MRI or MRA) to assist diagnosis (for details, see "Oral and Maxillofacial X-ray Diagnostics" and related reference books), and refer to treatment.

From the perspective of cell biology classification, vascular lesions in adults should basically be vascular malformations. Arteriovenous malformations, microvenous malformations, and lymphatic malformations in infants and young children are also vascular malformations. The so-called bayberry-like hemangioma, which is higher than the skin, is more likely to spontaneously resolve, and should generally be a hemangioma. How to determine the type of venous malformations found in infants, especially at birth, needs further study. Some studies have pointed out that vascular endothelial growth factor (VEGF) and estrogen receptors in serum are significantly increased in hemangioma; and the apoptosis gene bcl-2 is highly expressed in vascular malformations, but it is for reference only.

Arteriovenous malformations are different from aneurysm or acquired arteriovenous fistula. Aneurysm is a tumor-like dilation caused by middle-layer elastic fibrous lesions in the arterial wall. Acquired arteriovenous fistulas are caused by local arterial dilatation and even rupture and access to associated veins. They are generally located deeper and more localized.

False aneurysm can also occur after maxillofacial and neck trauma, which is more common in the parotid gland or upper neck. It is a pulsating lesion formed by ruptured arteries and blood stored in soft tissues; pathological examination shows fibers Walls and blood clots. More arterial angiography can confirm the diagnosis.

Treatment of vascular malformations and vascular malformations

An overview of vascular malformations

The treatment of hemangioma vascular malformation should be determined according to the type of lesion, location and the age of the patient. Current treatment methods include surgical resection, radiation therapy, hormone therapy, hypothermia, laser therapy, and sclerotherapy. Comprehensive treatment is generally used. Hemangiomas in infants and young children should be observed. If the development is rapid, certain interventions should be given in time.

Infant or childhood hemangioma, the vascular wall endothelial cell layer is still in the embryonic state, is more sensitive to hormone therapy, and for fast-growing infants and young children (especially those within 1 year of age), try prednisone or Intratumoral injection of prednisolone can sometimes make the tumor shrink significantly and stop growing; it can also be helpful for the diagnosis of hemangiomas.

Vascular malformations are not sensitive to hormone therapy. The effect of radiation therapy is not completely certain, and it is carcinogenic, so most people currently oppose the use of radiation therapy. Removable vascular malformations can be treated surgically. The wound after the tumor resection can be directly sutured or repaired with local skin flaps; large wounds require free skin grafting; defects that require puncture require tissue transplantation. Vascular malformations of the lips and tongue should be removed without affecting function. If the tumor is too large, it should be removed in stages, or sclerosing agents should be injected into the remaining lesions after removal to avoid affecting function and appearance.

Intravascular injection of vascular sclerosing agent

Venous malformations can be injected intravitreally with 5% sodium morrhuate or other sclerosing agents, causing fibrosis and occlusion of the diseased tissue, and reduction or disappearance of the diseased tissue. The surrounding tissues should be temporarily compressed during the injection to block blood flow; the injection should be administered once every 1 to 2 weeks. The injection dose depends on the size of the lesion. Generally, sodium codoleate is not more than 5ml at a time. If the effect is not good, surgical resection or hypothermia can be used. Facial venous malformations can be treated with argon ion (Ar) laser or krypton ion (Kr) photochemotherapy. YAG laser or hypothermia treatment has a certain effect on submucosal venous malformations.

Surgical treatment of vascular malformations

Arteriovenous malformations are mainly treated with surgery. During the operation, the artery communicating with the tumor should be ligated and cut off, and then the lesion is removed. Sometimes due to extensive lesions, one or both external carotid arteries should be ligated during surgery to reduce bleeding. In recent years, due to the development of interventional radiology, transcather arterial embolization (TAE, TCAE) can be applied to control and reduce intraoperative bleeding. Its hemostatic effect is far better than that of external carotid ligation; because in addition to the arterial trunk, all levels of the artery can be embolized up to the terminal branch, there is no sudden drop in peripheral blood pressure, the lumen is open, but a side branch circulation Disadvantages. A commonly used effective and safe embolic material is gelatin sponge.

It should be noted that there have been attempts to apply external carotid ligation alone to treat arteriovenous malformations. Experience and experimental research have proven that it is not only ineffective, but also can promote the formation of irregular collateral circulation, which will bring difficulties and troubles to further treatment in the later stage. The application of external carotid ligation for arteriovenous malformation is not only ineffective, but also theoretically wrong.

Central jaw vascular malformation is very easy to bleed during surgery. In addition to preparing sufficient blood sources, low temperature and antihypertensive anesthesia can be used to control bleeding. During surgery, one or both external carotid arteries should be ligated, or the inferior alveolar artery (or maxillary artery) should be ligated directly; of course, TAE technique can more effectively control intraoperative bleeding than external carotid artery ligation.

In the past, osteotomy was mostly used for central vascular malformations of the jaw. Currently, conservative surgery is tended to be used as much as possible. Among them, interventional treatment has been initially successful and should be the first choice. Secondly, you can choose to scrape only the bone lesions after effective bleeding control, and retain more bone tissue to maintain the facial appearance. Of course, osteotomy can also be used in cases where bone destruction is too large and bleeding is difficult to completely control.

Lymphatic malformations are mainly treated by surgery, especially for microcapsule patients. Small lesions can be completely removed; large lesions can also be removed in stages, or partial resection for improved function and appearance.

Angioplasty Pingyangmycin Treatment

In recent years, there have been more and more reports of using pingyangmycin to treat vascular malformations. The main indications are venous malformations and macrocystic lymphatic malformations, and certain effects have been achieved. Since Pingyangmycin is an anticancer drug, its long-term efficacy and adverse reactions need to be observed.

At present, although there are many methods for treating hemangiomas and vascular malformations, the problem of treating large vascular malformations has not been completely solved. Due to advances in plastic surgery, especially microsurgical technology in recent years, "radial" resection and defect repair of some huge vascular malformations has become possible and will be adopted by more physicians; Accepted by patients