Vascular malformations of the head, face, and neck” is often used as a general term and includes a number of different abnormalities that usually occur in children or young adults. They may appear as a cosmetic blemish or mass, or may come to attention by causing a disturbance of function. Vascular malformations have received different names depending on the cause.
A hemangioma is a benign blood vessel tumor appearing within the first month of life. The tumor may grow rapidly, disproportional to the child’s growth, during what is known as the proliferative phase, and usually reaches a maximum size when the child is between one and three years of age. The hemangioma then begins to get smaller during the involutive phase.
Eventually, in most cases, all that remains is some excess fatty fibrous tissue (like wrinkled skin) that can easily be removed by a plastic surgeon. Generally, hemangiomas only require treatment early in life if they bleed or result in some obstruction of normal function, for example the inability to close the eye. Embolization of the hemangioma may be performed to stop bleeding or preserve function.
A true vascular malformation, on the other hand, is usually present at birth, grows proportionally with the child, does not go through a proliferative or involutive phase, and does not disappear. Vascular malformations may become apparent later in life as blood flow increases through this abnormal connection between arteries and veins. They may cause cosmetic deformities of the head and neck, face and facial bones, mouth, tongue, nose or eyes, and interfere with normal function in these areas. At times the lesion can result in severe or uncontrollable bleeding.
Vascular malformations may be influenced by hormonal changes occurring during puberty and pregnancy. As opposed to hemangioma, most vascular malformations will require treatment.
Venous vascular malformations, another type of vascular anomaly of the head, neck and face, appear as a bluish discoloration of the skin, lips or inside of the mouth. They tend to increase in size with effort such as crying, pushing or other maneuvers that increase pressure in the venous system. While they can be disfiguring, they usually are not life-threatening. The treatment of venous vascular malformation has markedly advanced with the use of fluoroscopic (viewed by x-ray) guided sclerotherapy.
Sclerotherapy refers to the direct injection of a substance that will produce scarring within the vascular lesion. Different substances (sclerosing agents) have been used to achieve this goal.
A multidisciplinary team of specialists, including endovascular neuroradiologist, plastic and reconstructive surgeons, oral and maxillofacial surgeons, psychologists and other specialists is frequently required to treat these complex problems.
There are several groups of patients in whom bleeding from a tumor needs to be controlled. This may include pre-operative treatment of neck masses (paragangliomas and juvenile angiofibromas) or skull base lesions (meningiomas) to decrease the time and risk of surgery. Other patients with radiation and recurrence of head and neck cancers of the tongue or pharynx/larynx may require treatment to stop bleeding while more definitive treatment is implemented. These patients are usually treated one day to two days prior to surgery.
PARENT ARTERY OCCLUSION & COVERED STENTS
Specific blood vessel lesions are amenable to deconstructive surgery. Patients who have giant cavernous aneurysms may present with headaches and double vision. If there is collateral circulation in the brain, carotid occlusion may be the treatment of choice. When direct flow and pressure is taken off the aneurysm, it may regress and symptoms of double vision resolve. Another group of patients who may benefit from carotid occlusion are those with advanced squamous cell cancer involving the carotid artery in the neck and also skull base tumor affecting the carotid artery. Also some patients with dissecting aneurysms or fistulas may require trapping of an abnormal segment of an artery. Temporary balloon occlusion test is done in these patients to identify those patients at risk for stroke. In some of these cases a covered stent may also be considered if the artery shows signs of tumor invasion and bleeding but cannot be sacrificed. Some trauma patients may need to have an artery blocked off to prevent life threatening blood loss. This may be accomplished with balloons or coils.
The procedure is done under general anesthesia. A sheath is placed in the femoral artery in the groin, and a catheter is navigated into the affected artery. Under fluoroscopic visualization a series of detachable balloons or coils are placed to close off the artery. The catheter is then removed and the patient is wakened from anesthesia. The patient is then kept flat for 24 hours and given bold pressure raising medications to ensure there is sufficient perfusion pressure to the brain. Over the next 3 days, the patient is advanced slowly into an upright position with close neurologic supervision. Patients receive a specific anticoagulation regimen during this time.
SPINAL DURAL AVM/AVF
Vascular lesions affecting the spine and spinal cord are categorized into 4 basic types:
- Arteriovenous fistula (DAVF) arising within the dura of a nerve root with drainage into spinal veins
- Arteriovenous malformation (SAVM) in the spinal cord tissue
- Juvenile AVM (metameric) which involves all of the tissue at contiguous levels
- Perimedullary arteriovenous fistula on the surface of the spinal cord
These malformations lack the normal small blood vessels or capillaries that lay between the arteries and veins, and that serve to slow blood flow and allow it to provide oxygen and nutrients to the tissues. The resulting increase in blood flow may cause an increase in the pressure within the veins that drain off the spinal cord, and a decreased ability of these veins to clear blood from the area. This can result in a loss of spinal cord function or hemorrhage (bleeding) into the spinal cord or the liquid surrounding the spinal cord.
SAVMs may present with abrupt pain, progressive loss of strength or sensation, or bowel, bladder or sexual dysfunction. The diagnosis of this condition can usually be made with MRI images of the spine, but spinal angiogram is required to confirm the diagnosis and to delineate the spinal cord vascular anatomy, which is essential for planning treatment.
A multidisciplinary team of specialists including endovascular surgeons, neurosurgeons, neurologists and neurophysiologists is required to treat this condition.
Treatment options are dictated by the location of the lesion and the patient’s condition. Lesions on the surface of the spinal cord may be safely treated with embolization. The new generation of liquid embolic material and microcatheters has made interventional treatment of spinal cord malformations safer and with better results. Microcatheterization is very important in achieving effective results. Delivery of embolic material to the nidus of the lesion reduces the spinal malformation and reduces the risk of inadvertent embolization of normal vessels.
AVM’s consist of artery to vein abnormal connections, which pass through a nidus of rapidly shunting channels. AVF’s are direct end to end connections from artery to vein with fast flow, and they may be single or multiple. Some AVM’s have fistulous components. This group of spinal lesions is treated differently from one another depending on the arterial supply to the lesion, degree of cord involvement, and location arteries supplying the cord itself. They may be treated by a single modality or they may require a combination embolization, surgery or radiation therapy.
As part of the work up for a spinal vascular lesion most patients undergo an MRI study with gadolinium contrast enhancement. MRA with gadolinium may also be of assistance to identify the levels of involvement. The definitive diagnostic study is spinal angiography, which may be done under local anesthesia. The goal is to identify both normal and pathologic vascular anatomy to allow proper decision-making. We work closely with our Neurology department in the care of these patients.
Research indicates that osteoporosis can be caused by a diet lacking in calcium, excessive alcohol consumption (particularly in men), menopause, chronic steroid therapy and smoking. It is estimated that 1 in 3 women and 1 in 8 men over the age of 50 has osteoporosis-worldwide. Fractures, which result from abnormal bone thinning, can result in pain and disability. Vertebroplasty and kyphoplasty are minimally invasive methods of treating patients with compression fractures of the spine. Medical bone cement is injected into the collapsed vertebral body to stabilize and in some cases improve vertebral body height. Vertebroplasty can also be used to stabilize vertebrae affected by tumors such as hemangiomas, metastases, lymphoma or myeloma. Patients are evaluated in our department and may undergo tests such as plain x-rays, CT scan or MRI of the spine to identify their condition.
In most cases vertebroplasty is performed as day procedure with local anesthesia which also may include IV medications for relaxation and pain control. Patients are placed prone on the procedure table. After sterile preparation and administration of local anesthesia, a needle is placed in the affected vertebral body along the pedicles. Under direct fluoroscopic visualization, a mixture of polymethyl methacrylate cement (PMMA) and an opacifying agent such as barium are injected into the bone. When the appropriate amount has been administered, the needle is removed and a bandage is placed over the small incision. Many patients experience instant relief of painful symptoms. These are safe procedures and patients are watched for several hours in the hospital and can be sent home the same day.
Advantages of Vertebroplasty -
Vertebroplasty is considered for patients with painful compression fractures in the spine, often caused by osteoporosis. Because the treatment often results in a dramatic decrease in pain, the advantages are numerous.
Decreased pain— A compression fracture causes sharp and debilitating pain. Those suffering from these fractures are often prescribed bed rest and pain medication which may cause gastric and renal problems. Vertebroplasty eliminates pain in more than 90% of cases and in some cases eliminates the need for pain medication, and it also restores mobility in many patients.
Increased functional abilities— The pain from a compression fracture is usually sharp and debilitating, leaving people unable to perform everyday tasks. Vertebroplasty stabilizes the fracture, decreases pain immediately and allows a return to the previous level of activity at the earliest.
Prevention of further vertebral collapse—The cement fills spaces in bones made porous by osteoporosis, strengthening the bone so that it does not fracture again. None of these can be accomplished with analgesics, oral calcium and braces alone.
Kyphoplasty is a minimally invasive spinal surgery procedure. It is used to treat painful progressive vertebral body collapse/fracture (VCFs). The VCFs may be caused by osteoporosis or the spread of tumor to the vertebral body.
Osteoporosis is age related softening of bones. It causes the building blocks of the spine to weaken and collapse. This results in severe pain and a progressive hunchback. Certain forms of cancer also weaken the bone and cause the same problems.
Kyphoplasty is not appropriate for:
* Patients with young, healthy bones or those who sustained a vertebral body fracture or collapse in a major accident
* Patients with spinal curvature such as scoliosis or kyphosis that is due to causes other than osteoporosis
* Patients who suffer from spinal stenosis or herniated discs with nerve or spinal cord compression and loss of neurological function not associated with a vertebral compression fracture
The kyphoplasty procedure involves the use of a balloon to restore the vertebral body height and shape. This is followed by bone cement to strengthen it. The procedure may be performed under intravenous sedation. The patient may need local anesthetic or general anesthetic. The patient lies face-down on the operating room table. The interventionist makes two small (less than 3mm) incisions. He or she inserts a thin metallic tube into the center of the vertebral body. Through this tube, balloons are placed in the center of the vertebral body. Then the balloons are inflated. This pushes the bone back towards its normal height and shape. It also helps create a cavity. Then the cavity is filled with the bone cement.
Early results show kyphoplasty is a safe and effective method of vertebral reconstruction and stabilization in the treatment of osteoporotic compression fractures. Like all surgeries, kyphoplasty does have risks.
Complications may require additional treatments. These may be medications or surgery. Kyphoplasty is associated with excellent pain relief due to the vertebral body collapse. Well over 95 percent of patients rate their treatment a success. They are able to return to all of their pre-fracture function. Patients typically do not need any form of physical therapy or rehabilitation after a kyphoplasty procedure. Because bone cement hardens within 15 minutes, there is really no healing that needs to happen from the patient’s standpoint.
Occasionally, patients complain of persistent pain after kyphoplasty. This may be due to irritation of tissues involved in the procedure itself. It is more likely due to the underlying arthritis and degeneration of the spine.
* Pain due to the procedure will typically diminish within two weeks.
* If the pain is due to the arthritic degenerative changes in the spine, the usual treatment is medications and an ongoing exercise program.
Restoring vertebral body height and size is best accomplished when kyphoplasty is performed soon after the fractures happen. After kyphoplasty, severe osteoporosis may cause other fractures at other levels in some patients. All patients must take bone-strengthening medications during treatment. If more vertebrae collapse, kyphoplasty can also be used at those other levels. Kyphoplasty has a tendency to help prevent more fractures. It keeps the spine lined up in its native upright position.
* The usual risks of local or general anesthetics apply. These risks depend on the patient’s overall health.
* There is a small risk of the bone cement leaking from within the boundaries of the vertebral body. In most cases, this rare event (occurrence less than 10 percent) does not cause any problems.
* In very rare circumstances the cement may irritate or damage the spinal cord or nerves. This can cause pain, altered sensation, or even, very rarely, paralysis (estimated risk is less than 1 in 10,000). Should the cement leak further, more significant surgery may be needed to stop the irritation of the nerves or spinal cord.
* There is also a very small chance of the cement traveling to lungs. There is an even smaller chance of the cement block becoming infected at the time of surgery or even years later.
VENOUS SINUS OCCLUSIVE DISEASE
An uncommon vascular abnormality is that of venous occlusive disease. This may result from a variety of hypercoagulable states such as paraneoplastic syndromes, birth control pills, and genetic variations in which clotting factors are abnormal. As a result the slow flow within the veins may lead to clot formation. This affects normal circulation in the brain and can lead to edema, stroke or hemorrhage. In the hospital a CT venogram or MR venogram will be obtained to make the diagnosis. The Neurologist will likely treat with anticoagulation medications including heparin and possibly oral anticoagulant medications. If patients present with serious neurologic deficit, an interventional procedure to lyse the clot may be necessary. This is accomplished under general anesthesia, and the procedure may last 4-6 hours. A sheath is placed in the femoral artery, and an angiogram is done to look at the circulation in the brain from the arteries to the veins. When the clot is identified, a second sheath is placed in the vein and a catheter is placed next to the clot in the affected venous sinus. A microcatheter is passed through the clot and medication is administered to break up the thrombus (tPA or urokinase). The sheaths may be left in for a few days in case a second treatment is necessary. Patients are monitored in the Neuro-intensive care unit.
PETROUS SINUS SAMPLING
Bilateral simultaneous sampling of the inferior petrosal sinuses is an extremely sensitive, specific, and accurate test for diagnosing Cushing disease and distinguishing between that entity and the ectopic ACTH syndrome. It is also valuable for lateralizing small hormone-producing adenomas within the pituitary gland. The inferior petrosal sinuses connect the cavernous sinuses with the ipsilateral internal jugular veins. The anatomy of the anastomoses between the inferior petrosal sinus, the internal jugular vein, and the venous plexuses at the base of the skull varies, but it is almost always possible to catheterize the inferior petrosal sinus. In addition, variations in size and anatomy are often present between the two inferior petrosal sinuses. Advance preparation is required for petrosal sinus sampling. Teamwork is a critical element, and each member of the staff should know what he or she will be doing during the procedure. The samples must be properly labeled, processed, and stored. Specific needles, guide wires, and catheters are recommended for this procedure. The procedure is performed with specific attention to the three areas of potential technical difficulty: catheterization of the common femoral veins, crossing the valve at the base of the left internal jugular vein, and selective catheterization of the inferior petrosal sinuses. There are specific methods for dealing with each of these areas. Images must always be obtained to document correct catheter position. The patient must be given an adequate dose of heparin, and injection of contrast material into the inferior petrosal sinuses and surrounding veins must be done gently and carefully. When the procedure is performed, both inferior petrosal sinuses can be catheterized in more than 98% of patients. The complication rate is low, and the theoretical risk of major morbidity or death is less than 1%.
A cirsoid aneurysm of the scalp is an abnormal fistulous connection between the feeding arteries and draining veins, without an intervening capillary bed. Soft tissue arteriovenous fistulae occur most commonly in the scalp. Although only 14% of the body surface area is in the head, 50% of the integument arteriovenous fistulae occur in this region. When these abnormal fistulae enlarge to a size that is clinically recognizable and there are large, dilated draining veins, the lesions are termed cirsoid aneurysms.
Most congenital lesions become symptomatic in the third decade of life. Sixty per cent of the affected persons are male. The location of scalp cirsoid aneurysms is roughly evenly distributed among the frontal, temporal and parietal regions.
Although controversy still exists regarding the cause of these lesions, it is generally accepted that they may be either of congenital or traumatic origin. In our series, 20% of the lesions could be directly related to trauma (blunt, non-penetrating trauma in the majority). Penetrating trauma as a cause is well described, including iatrogenic-induced fistulae after hair transplantation, arthroscopy of the temporomandibular joint and craniotomy for intracranial procedures. Almost all patients present with a scalp swelling that has gradually increased in size from birth or after head trauma. Rapid increases in size have been reported to occur at puberty, during menstruation and during pregnancy. Associated symptoms and signs include pain, throbbing headaches and bruits. Hemorrhage from the lesion is uncommon. Large lesions have also been associated with scalp necrosis.
The diagnosis is clinical in the majority of patients. Angiography is undertaken to delineate the lesion and to exclude an intracranial component. This takes the form of an enlarged middle meningeal artery with fine feeding vessels running through the bone feeding the malformation.
Indications for treatment are the prevention of hemorrhage, tinnitus and the cosmetic relief of the pulsatile swelling. Treatment options include surgical transarterial and transvenous embolization, injection of sclerosant into the nidus and surgical excision. In the past, treatment of arteriovenous malformation of the scalp and face was primarily reliant on surgical excision or ligation of the feeding arteries. Some lesions were so large that excision was not possible. Ligation of feeding arteries has been particularly troublesome because of the recruitment of a collateral vessel supply and the loss of access to the fistula for further embolization. Transarterial and transvenous embolization of scalp cirsoid aneurysms has been used as an adjunct to surgery or as definitive therapy. Embolization alone could remedy a scalp arteriovenous fistula and improve the grotesque feature without scalp ischemia.
In direct-puncture embolization, the targeted vessel is the venous structure just distal to the arteriovenous connection. Occlusion of the vascular structures with this technique thus involves no risk of ischemic skin complications. Immediate venous occlusion allows continuous redistribution of the embolic agent to adjacent vascular spaces and effective devascularization occurs without complications. In most lesions, a large, high-flow arteriovenous fistula often is associated with the aneurysm and the embolus must, therefore, be large; otherwise, the embolus may pass into the pulmonary circulation. Temporary manual compression of the venous drainage during NBCA injection slows down the blood flow and can prevent inadvertent washout into the distal venous outflow tract and pulmonary circulation.
Lodging of embolic materials like coils in proximal feeding vessels lessens the blood supply and has been a helpful adjunct to surgery but rarely is curative. Recent developments in the design of microcatheters and distal navigation techniques have made possible the catheterization of feeding arteries close to the nidus. Injection of NBCA with a microcatheter wedged into the nidus may lead to permanent devascularization of an arteriovenous malformation without risk of ischemia of the adjacent normal tissue. But total devascularization involving transarterial embolization of the multiple feeding arteries may, however, be ineffective or technically difficult. So transarterial route of embolization can only be used as an adjunct to direct-puncture embolization of cirsoid aneurysms.