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Vascular Anomalies in Children

Vascular Anomalies in Children







Oral and Maxillofacial Surgery Clinics, 2012-08-01, Volume 24, Issue 3, Pages 443-455, Copyright © 2012 Elsevier Inc.


The process of understanding and treating children with vascular anomalies has been hampered by confusing and occasionally incorrect terminology. The most important step when evaluating a maxillofacial vascular anomaly is to determine whether it is a tumor or a malformation. In most cases, this diagnosis can be made by history and physical examination. Selective radiographic imaging is helpful in differentiating vascular malformations or the extent of bony involvement and/or destruction. Children with vascular anomalies should be managed by an interdisciplinary team of trained providers who are committed to following, treating, and studying patients with these complex problems.

Key Points

  • Most vascular anomalies are diagnosed by history and physical examination.

  • Treatment of patients with vascular anomalies has been hampered by confusing and incorrect terminology. Correct diagnosis (tumor or malformation) is critical to caring for these patients because it dictates medical and/or surgical management.

  • Patients with vascular anomalies are best treated by a multidisciplinary team made up of several surgical, radiologic, and medical specialists.

  • Hemangioma is a benign vascular tumor; a vascular malformation is composed of abnormally formed lymphatics and/or blood vessels.


Introduction

Treating patients who have vascular anomalies has been hampered by confusing and incorrect terminology. In 1982, Mulliken and Glowacki proposed a biologic classification system based on endothelial cell kinetics and clinical behavior. They described 2 types of vascular anomalies: hemangiomas and vascular malformations. In 1996, the International Society for the Study of Vascular Anomalies adopted an expanded classification system and categorized vascular anomalies into tumors and malformations. More than 90% of vascular anomalies can be diagnosed based on history and physical examination. Ultrasound (US), magnetic resonance imaging (MRI), and computed tomography (CT) can be used to confirm the clinical diagnosis, and to document the extent and flow characteristics.

Hemangioma is a benign vascular tumor; approximately one-third are present at birth and two-thirds appear after birth. The defining feature is rapid growth in infancy. In contrast, a vascular malformation occurs as the result of abnormal embryonic development. Vascular malformations are present at birth and expand commensurately with growth of the child. Vascular malformations are categorized as slow-flow (capillary malformations [CM], lymphatic malformation [LM], and venous malformation [VM]) and fast-flow lesions (arterial malformations and arteriovenous malformations [AVMs]). Histologically, hemangiomas show endothelial hyperplasia and glucose transporter-1 protein (GLUT1) immunopositivity, whereas vascular malformations have slow endothelial turnover and are GLUT1 negative. Hemangiomas rarely cause skeletal hypertrophy or deformation of adjacent bone, whereas slow-flow vascular malformations can cause bony deformation, and fast-flow lesions typically cause osteolysis.


Hemangiomas

The infantile hemangioma (IH) is a common tumor of infancy occurring in 4% to 10% of white newborns. However, the incidence is 23% in premature infants weighing less than 1200 g. The tumor occurs more commonly in girls, with a gender ratio of 2.4:1. Approximately 60% of IHs occur in the head and neck region, and 20% of infants with IH have multiple lesions that can occur in the liver, brain, and/or gastrointestinal tract.

IHs have a life cycle consisting of 3 phases that can be distinguished clinically, microscopically, and immunohistochemically. Most IHs are not present at birth but appear during the first 2 weeks of life, although 30% to 50% of IHs are seen at birth as a telangiectatic stain or ecchymotic area. The IH grows during the first 6 to 9 months (proliferating phase) ( Fig. 1 ). After 12 months of age, the tumor begins to shrink and flatten and the color fades (involution phase). By age 5 years, complete resolution occurs in more than 50% of children, with continued improvement until age 10 to 12 years (involuted phase). However, nearly one-half of children have a residual abnormality, including redundant atrophic skin, yellow discoloration, residual fibrofatty tissue, and/or telangiectasia ( Fig. 2 ).

A 3-month-old girl with proliferating hemangioma of upper lip.
Fig. 1
A 3-month-old girl with proliferating hemangioma of upper lip.

( A ) Involuting IH at age 3 years. ( B ) Age 9 years with involuted and regressed IH with residual discolored and scarred tissues.
Fig. 2
(
A ) Involuting IH at age 3 years. (
B ) Age 9 years with involuted and regressed IH with residual discolored and scarred tissues.

IHs can occur in association with other anomalies to make up an association that consists of plaquelike IH in a segmental or trigeminal dermatomal distribution of the face with at least 1 of the following anomalies: posterior fossa brain malformation, hemangioma, arterial cerebrovascular anomalies, coarctation of the aorta and cardiac defects, eye/endocrine abnormalities (PHACE). Because 8% of children with PHACE have a stroke in infancy and 42% have a structural brain anomaly, patients with PHACE should have a brain MRI. PHACE association affects approximately 2% of patients with IH.

There are rare vascular tumors that occur fully grown at birth and do not exhibit the expected postnatal course and life cycle of IH. The congenital hemangioma (CH) consists of 2 subtypes: rapidly involuting congenital hemangioma (RICH) and the noninvoluting congenital hemangioma (NICH). RICH commonly occurs on the trunk and extremities but also in the head and neck and liver. They are raised, with a characteristic red-vilaceous color, central telangiectasias, superficial ulceration, and a peripheral pale halo. RICH involutes rapidly during the first few weeks or months of life. NICH are typically well circumscribed, slightly raised, averaging 5 to 6 cm in diameter. They are light gray in color with prominent coarse telangiectasias, warmth on palpation, and a predisposition for the mandibular border.


Management

Most IHs are small, localized, and do not involve aesthetically or functionally important areas. These IHs can be managed by observation and waiting for involution. Infants should be followed on a monthly basis during the proliferative phase and yearly during the involuting stage. Spontaneous ulceration can occur in 20% of cutaneous hemangiomas, possibly causing infection or local tissue destruction. Therapy is indicated for hemangiomas that cause destruction, distortion, or obstruction (eg, subglottic narrowing, blockage of visual axis). Intralesional corticosteroid injection (triamcinolone 3 mg/kg) has antiangiogenic properties that accelerate involution ; it stabilizes the growth of the lesion in at least 95% of patients, and 75% of tumors decrease in size. Thus, it is best for a small, well-localized IH that is less than 2 cm in diameter. The corticosteroid lasts 4 to 6 weeks and therefore multiple injections during the proliferative phase may be necessary. Daily oral prednisolone is recommended for an IH that is large, rapidly growing, and causing distortion of facial features, ulceration, and/or impinging on anatomic structures. When the tumor is no longer proliferating, the dose can be decreased slowly to prevent rebound tumor growth and adrenal crisis.

Propranolol has also been successfully used in some centers to treat IHs. Oral or intravenous administration of 2 mg/kg per day in divided doses reduced the volume, color, and elevation of IHs. Thorough pretreatment evaluation, inpatient monitoring of vital signs and blood glucose levels at initiation of therapy, and frequent reassessments are necessary since propranolol can cause bradycardia, hypotension, and hypoglycemia, although cardiovascular side effects have been infrequent and minor. Side effects seem to be primarily minor gastrointestinal disturbances and are easily managed. Although promising, propranolol's efficacy and safety compared with corticosteroids in this patient population is still unknown. Fig. 3 shows management of an enlarging and bleeding IH that did not respond to steroid injections. Propranolol administration was initiated when the lesion continued to enlarge and, after 2 weeks, shows some shrinkage. Next-line therapy (vincristine, interferon-α) is indicated if the patient fails to respond to first-line agents and/or there are contraindications to prolonged systemic use of corticosteroids.

( A ) Large, progressive IH lesion measured 7 cm by 6 cm before propranolol administration. ( B ) Two weeks after initiation of propranolol the IH is blanched, softer, and measures 4 cm by 3 cm.
Fig. 3
(
A ) Large, progressive IH lesion measured 7 cm by 6 cm before propranolol administration. (
B ) Two weeks after initiation of propranolol the IH is blanched, softer, and measures 4 cm by 3 cm.

Resection is a consideration at any time during the hemangioma life cycle. If there is obstruction of a vital structure, recurrent bleeding, and/or ulceration, excision can take place early during the proliferative or involuting stage ( Fig. 4 ). After involution, there may be residual fibrofatty tissue, redundant or damaged skin that can be removed. Although waiting until the hemangioma has involuted ensures that the least amount of tissue is resected, leaving the smallest possible scar, this must be weighed against the psychosocial morbidity of having a deformity until late childhood. The conventional method of excision is in a lenticular format with linear closure in the axis of the relaxed cutaneous tension lines, either as a single or a staged procedure. However, a circular excision and purse-string closure converts a circular lesion into a small circular or ellipsoid scar. A second excision results in the smallest possible scar with minimal distortion of surrounding structures ( Fig. 5 ).

( A ) One-year-old girl with IH affecting nasal patency and chewing. ( B ) MRI coronal image showing hemangioma of right lip and cheek. ( C ) Excision of lesion through nasolabial approach. Note the circumferential purse-string suture. ( D ) Defect after excision. ( E ) One year after excision of IH. ( F ) Age 5 years (four years post excision).
Fig. 4
(
A ) One-year-old girl with IH affecting nasal patency and chewing. (
B ) MRI coronal image showing hemangioma of right lip and cheek. (
C ) Excision of lesion through nasolabial approach. Note the circumferential purse-string suture. (
D ) Defect after excision. (
E ) One year after excision of IH. (
F ) Age 5 years (four years post excision).

( A ) Two-year-old girl with hemangioma of right forehead. ( B ) Age 8 years, after involution of hemangioma with evidence of residual tissue before excision. ( C ) Patient at age 12 years, with minimal scarring after excision.
Fig. 5
(
A ) Two-year-old girl with hemangioma of right forehead. (
B ) Age 8 years, after involution of hemangioma with evidence of residual tissue before excision. (
C ) Patient at age 12 years, with minimal scarring after excision.

Vascular malformations

Vascular malformations are abnormally formed lymphatics or blood vessels. They are characterized by the affected vasculature (capillaries, arteries, veins, and/or lymphatics), flow characteristics (slow or fast), and number of involved vessels (single or multiple). US helps to distinguish arterial malformations, VMs, and LMs. MRI is the gold standard to determine the type and extent of the lesion. Vascular malformations can cause disfigurement and local complications (ie, destruction of anatomic structures, infection, obstruction, pain, thrombosis, ulceration). They can also lead to, disseminated intravascular coagulation, pulmonary embolism, and thrombocytopenia, and congestive heart failure.


Slow-Flow Vascular Malformations


Capillary Malformation

CMs, also known as port-wine stains, are present at birth and persist throughout life ( Fig. 6 ). They are found in approximately 0.3% of newborns, with an equal sex distribution. They appear as macular pink stains that blanch with pressure and they can occur anywhere on the body. Facial CMs often occur in a dermatomal distribution: 45% are restricted to 1 of the 3 trigeminal dermatomes, whereas 55% overlap sensory dermatomes, cross the midline, or occur bilaterally. Facial CMs tend to gradually darken to an intense red hue during young adulthood and to a deep purple during middle age. The skin thickens and becomes raised with multiple nodular fibrovascular lesions. There can be associated overgrowth of soft tissue, gingiva, and skeleton in the area of the stain. Gingival overgrowth and intraoral pyogenic granulomas are common; prevention includes good oral hygiene and regular dental cleanings. Procedures in the oral cavity (eg, gingivectomy, extractions, osteotomies) can be done without concern for excessive bleeding.

Port-wine stain (CM) involving the right maxillary and mandibular dermatome distributions.
Fig. 6
Port-wine stain (CM) involving the right maxillary and mandibular dermatome distributions.

Sturge-Weber syndrome is defined as a CM in the ophthalmic and/or maxillary (trigeminal) distributions associated with leptomeningeal capillary and venous anomalies and vascular lesions of the ocular choroid. The leptomeningeal vascular lesions can cause refractory seizures, hemiplegia, and variable delayed motor and cognitive development. Anomalous choroidal vascularity can result in retinal detachment, glaucoma, and blindness. Some patients exhibit major maxillary and/or mandibular overgrowth with evidence of vascular changes in bone.


Management

Management of CM consists of pulsed dye laser and multiple treatments are often needed in yearly intervals, with 50% of patients achieving approximately 70% improvement. Other laser modalities such as long pulsed laser and photodynamic therapy, are being studied. Labial hypertrophy, a common problem in patients with facial CM, can be managed by contour resection. Orthognathic correction may be safely performed for occlusal canting caused by asymmetrical maxillary overgrowth or mandibular prognathism.


Lymphatic Malformation

LMs result from an error in the embryonic development of the lymphatic system. Sprouting lymphatics may become separated from the primitive lymph sacs or main lymphatic channels, or lymphatic tissue can form in an abnormal location. LM is characterized by the size of the malformed channels: microcystic, macrocystic, or combined. Isolated tiny mucosal or cutaneous blebs that are not radiographically detectable are microcystic LMs; large channel blebs that cannot be manually compressed are macrocystic LMs. LMs can occur anywhere in the body; those in the head and neck region occur in the neck, cheek, and the cervicofacial region (incorrectly termed cystic hygroma) with extension into the mediastinum or orbit ( Fig. 7 ).

( A ) Mucosal blebs and microcystic LM of tongue. ( B ) Combined microcystic-macrocystic LM of right parotid and cheek. The lesion expands during feeding. ( C ) Cervicofacial LM of the neck and upper mediastinum.
Fig. 7
(
A ) Mucosal blebs and microcystic LM of tongue. (
B ) Combined microcystic-macrocystic LM of right parotid and cheek. The lesion expands during feeding. (
C ) Cervicofacial LM of the neck and upper mediastinum.

Prenatal US in the second trimester can detect large lesions. Most LMs are noted at birth or within the first year of life. LMs enlarge commensurate with the child's growth, but can suddenly expand as a result of cellulitis secondary to an upper respiratory tract infection or intralesional hemorrhage from injury to small vessels within the malformation. If there is LM in the floor of the mouth and tongue, the inflamed tissue can lead to macroglossia with dark-stained vesicles that tend to bleed. This has the potential to cause airway obstruction. Cervicofacial LMs are associated with overgrowth of the mandible and can result in a severe malocclusion and open bite ( Fig. 8 ). Two-thirds of patients with cervicofacial LM require tracheostomy to maintain their airways.

( A ) Frontal view of 10-year-old girl with obvious open bite and protruding tongue. ( B ) Lateral cephalograph shows mandibular prognathism with steep angle and open bite deformity.
Fig. 8
(
A ) Frontal view of 10-year-old girl with obvious open bite and protruding tongue. (
B ) Lateral cephalograph shows mandibular prognathism with steep angle and open bite deformity.

Management

Small or asymptomatic lesions are observed. Intralesional bleeding is treated with pain medication, rest, and/or antibiotics. Because LMs are at risk for infection, good oral hygiene should be maintained. Patients with more than 3 infections in 1 year are typically given daily prophylactic antibiotics. Symptomatic lesions that cause pain, significant deformity, or encroach on vital structures require treatment. Vesicles of the mucous membranes and dorsal tongue can be treated by laser or radiofrequency ablation. Persistent or larger LMs of the dorsal tongue may have to be treated surgically. Most patients require a combination of interventions to adequately treat LM of the lingual base and floor of mouth. Local trauma and/or infection can cause vesicular bleeding that can be controlled by embolization. Sclerotherapy is useful for large or problematic macrocystic/combined LM. Aspiration followed by an injection of an inflammatory agent (eg, ethanol, bleomycin, doxycycline) causes scarring of the cyst walls and the lesion shrinks. More than 90% of macrocystic LMs that are treated with sclerotherapy do not regrow.

Resection is indicated if sclerotherapy is no longer possible because all the macrocysts have been treated or if it will be curative because the lesion is small and well localized. Intraoral resection of the floor of mouth and tongue base should be avoided because of the high likelihood of postoperative functional problems. Aggressive debulking of an enlarged and protruding tongue can negatively affect speech and feeding secondary to insufficient functional lingual mass; however, to provide for optimal speech development, some surgical reduction or control of LMs may have to be undertaken. Many children have speech problems related to not only tongue bulk and reduced lingual mobility but also early tooth loss, palatal immobility, and poor oral competence. Cervicofacial LMs can be disfiguring because of tissue hypertrophy, bony enlargement, and malocclusion. Patients develop progressive mandibular overgrowth and prognathism, causing a class III malocclusion, steep mandibular plane angle, and anterior open bite ( Fig. 8 ). Orthognathic surgery can take place once the tongue size and position are acceptable; postoperative antibiotics (2–3 weeks) are warranted. Preoperative antibiotics are not typically necessary for extractions or resection but the airway must be appropriately managed.

Facial LMs that are amenable to resection, either because of their size or location (nonairway or nonorbital), or have been reduced and/or scarred by sclerotherapy, may be excised. As in hemangiomas, access incisions are placed in an anatomic margin or relaxed tension line. The parents should be informed that LMs are difficult to eradicate and that regrowth is possible. Also, postoperative scarring may alter the overlying soft tissue contour ( Fig. 9 ).

( A ) Before surgery and before administration of intralesional (saline) sclerosant to LM of left cheek. Two courses of intralesional therapy were performed 1 year apart. ( B , C ) Two years after excision through nasolabial and submental approaches. Note the skin contour irregularity and dimpling after healing. This was later grafted with fat and decellularized dermal allograft to restore the contour.
Fig. 9
(
A ) Before surgery and before administration of intralesional (saline) sclerosant to LM of left cheek. Two courses of intralesional therapy were performed 1 year apart. (
B ,
C ) Two years after excision through nasolabial and submental approaches. Note the skin contour irregularity and dimpling after healing. This was later grafted with fat and decellularized dermal allograft to restore the contour.

Venous Malformation

VMs are the most common type of vascular malformation. They are developmental abnormalities of veins composed of thin-walled, dilated channels of variable size and mural thickness with normal endothelial lining and deficient smooth muscle. The lesions expand, flow stagnates, and, as a result, clotting can occur. These lesions are blue-purple in color, soft, compressible, and nonpulsatile ( Fig. 10 ). A phlebolith is occasionally palpable and may cause pain, distention, and tenderness. In 90% of patients, VMs are solitary ; multifocal forms should raise the suspicion that there is a hereditary basis (eg, glomuvenous malformation, cutaneomucosal VM, cerebral cavernous malformation, blue rubber bleb nevus syndrome ).

An 8-month-old girl with VM of left lower lip and buccal mucosa.
Fig. 10
An 8-month-old girl with VM of left lower lip and buccal mucosa.

Although VMs usually grow in proportion with the child, enlargement can occur with trauma, puberty, and/or pregnancy. VMs can cause progressive distortion of facial features by causing skeletal alteration and hypertrophy without intraosseous involvement. Oral VMs can cause malocclusion as a result of the mass effect on the dentoalveolus. They rarely interfere with speech and feeding. Spontaneous and significant bleeding or life-threatening thrombosis is uncommon, although reports of life-threatening hemorrhage have occurred. Patients are usually not at risk for thromboemboli because the deep venous system is rarely affected. However, stasis in large or extensive venous anomalies is frequently associated with localized or generalized intravascular coagulopathy, which must be corrected before any surgical intervention.


Management

The first-line treatment of problematic VMs is sclerotherapy. The injected sclerosing agent causes cellular destruction, thrombosis, and intense inflammation. Scarring shrinks the lesion in 75% to 90% of patients and it often alleviates symptoms. However, VMs usually reexpand via recanalization and thus may require multiple treatments. Resection is indicated to reduce bulk and to improve contour and function. Resection without preoperative sclerotherapy is indicated for small, solitary VMs in anatomic sites that are dangerous to sclerose because of immediate proximity to vital structures like the eye or major nerves. Resection should usually take place following completion of sclerotherapy. Although complete excision of the VM is the therapeutic goal, this is often not possible because of the extent of the lesion and proximity to vital anatomic structures. In this case, only subtotal resection or contour resection is possible. Jaw surgery can be undertaken following preoperative treatment of localized coagulopathy, protection of the airway with tracheostomy, and the use of preoperative sclerotherapy.


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