Endovascular Laser Therapy

Endovascular laser ablation is a minimally-invasive, one-hour procedure that replaces the surgical stripping and binding commonly associated with varicose vein treatment.  Unlike the traditional method, which many patients found very painful and required up to six weeks recovery time, laser vein ablation involves minimal discomfort and immediate recovery for most patients.This procedure is an option for treating greater saphenous vein incompetence, which causes varicose veins.  The laser used in the procedure destroys the greater saphenous vein, relieving the backflow pressure and allows the blood to flow in the right direction.  This eliminates the varicose vein and the pain caused by it.

Laser Vein Ablation

Laser Vein Ablation is an outpatient procedure performed in our office. After anesthetizing the skin, an ultrasound of the veins of the leg is performed. Using the ultrasound as a guide, a thin laser fiber is inserted into the vein. A highly concentrated beam of laser light is sent through the fiber, which eliminates the abnormal vein.

Endovascular laser treatment device

An endovascular laser treatment device preferably includes a catheter having a hub at its proximal end, an optical fiber for insertion into the catheter, a fiber connector attached to the optical fiber at a selected distance from the distal end of the optical fiber, and a temporary stop removably mounted around the optical fiber. The treatment device has two positions: a protective position and an operating position. As the fiber is inserted through the catheter, the temporary stop rests against the hub and places the fiber tip in the protective position where the distal end of the optical fiber is positioned near the distal end of the catheter, but is still disposed inside the catheter. When the temporary stop is removed and the fiber connector is coupled with the catheter hub, the fiber tip is in the operating position where the distal end of the optical fiber extends past the distal end of the catheter by a predetermined distance to expose the fiber tip.

Treatment

Laser therapy allows a specialist to seal veins closed and reroute the flow of blood to other veins deeper within the leg. The procedure itself requires only a few minutes, and a follow-up appointment will help confirm that the veins have completely closed.

UT Southwestern endovascular therapists also use sclerotherapy injections to treat larger varicose veins that do not respond to laser treatments. Both types of treatments are minimally invasive and typically require three to five appointments over a period of three to six months. For patients who are candidates for sclerotherapy, we will use a schlerosing solution or similar medical treatment to absorb the vein and eliminate its appearance.

Endovascular procedures

Doctors often recommend these relatively new surgical procedures to patients who may not be able to withstand the stresses of major surgery, whether because of advanced age or because they have other serious medical conditions. However, these procedures are appropriate for less frail patients, too. Advantages include local or regional anesthesia instead of general anesthesia, shorter recovery time, less pain, smaller incisions, and less stress on the heart. These procedures may be used to treat aneurysms, cerebral vascular malformations, and arteries that have been occluded by plaque.

• Treatment of aneurysms: To repair an aneurysm, or a section of a vessel that has ballooned out, surgeons guide a coil (essentially, an artificial graft) into the damaged blood vessel and anchor it into place. This allows blood to flow normally again through the vessel, lowering the patient’s risk of a future hemorrhagic stroke. A long plastic tube called a catheter, which has been threaded up through a tiny incision in an artery in the thigh up to the trouble spot, is used to position the coil. X-ray imaging is used to guide the catheter.
• Treatment of cerebral vascular malformations: Endovascular surgeons may use a “superglue” substance introduced via a tiny catheter to eliminate or reduce the size of the cerebral vascular malformations. Often this facilitates further microsurgical or radiation treatment. Mechanical removal of blood clots: A new tool for treating hemorrhagic stroke is a tiny device used to physically remove blood clots that are blocking blood vessels within the brain. The Food and Drug Administration recently approved one such device, the Merci Retrieval System, which works like a corkscrew to pluck out clots. In nonbleeding (ischemic) strokes, blood clots damage the brain by depriving brain cells of the oxygen and nutrients (carried in the blood) they need to survive. But when used within the first several hours after a stroke, the device can extract clots and may reduce permanent damage.
• Angioplasty and stenting of vessels in the neck and brain: This new intervention is available at many medical centers. Cerebral angioplasty is similar to the widely used cardiology procedure, in which a tiny balloon attached to the tip of a catheter is threaded into a blocked artery and then inflated. In this case, the vessels are the carotid arteries in the neck, and a tiny tube-shaped bit of wire scaffolding, or a “stent,” is inserted into the blockage to keep it open after the balloon has been withdrawn. This procedure often is offered as an alternative to carotid endarterectomy for patients for whom the more invasive surgery is thought to be too risky, whether because of the patient’s overall health or because of the location of the blockage. Because angioplasty and stenting is fairly new, researchers are still investigating how well the stents hold up and how well the procedure reduces patients’ risk of stroke over the long term.
• Intra-Arterial Thrombolysis: For this procedure, doctors insert a small catheter into the blood vessels of the brain during cerebral angiography and deliver clot-dissolving medications directly to the blocked blood vessel.

Carotid endarterectomy

Carotid endarterectomy is a surgical procedure used to remove atherosclerotic plaque (fatty deposits associated with cardiovascular disease) from the carotid arteries. For selected patients who have had minor strokes or transient ischemic attacks (TIAs or ministrokes), carotid endarterectomy can be highly beneficial in preventing future strokes. The primary factor doctors consider when weighing this procedure for an individual patient is the extent to which plaque has narrowed the affected artery (“stenosis”). For patients with less than 50 percent stenosis, the benefits of carotid endarterectomy normally do not outweigh the risks. However, in patients with 70 to 99 percent

stenosis

 who have had recent symptoms caused by the stenosis, the surgery lowers the two-year risk of stroke by about 80 percent

Stereotactic procedures

Stereotactic techniques, which involve placing markers on the patient’s head to create reference points for very precise surgeries, allow surgeons to treat vascular malformations that were previously too difficult to reach. Stereotactic surgeries employ sophisticated computer technology in combination with MRI or CT scans to pinpoint the trouble spot. Using microscope-enhanced methods and delicate instruments, the surgeons can operate without affecting normal brain tissue.

Revascularization

Revascularization is a surgical technique for treating aneurysms or blocked cerebral arteries associated with atherosclerosis or moyamoya disease (a rare disease resulting in narrow or blocked vessels to the brain and irregular blood vessels). The technique essentially provides a new route of blood to the brain by grafting a blood vessel from the surface of the face near the temple to a cerebral artery through a hole in the skull.

Hypothermia

Preliminary studies with techniques that cool the brain or body suggest that doing so may improve outcomes for stroke patients in a variety of situations. Surgeons operating on stroke patients to correct cerebral vascular malformation and aneurysms, for instance, are finding that if they first chill the patient’s brain, he or she may be less likely to suffer another stroke during the surgery. Inducing hypothermia may also give the surgeon extra time to operate.Studies of patients who are comatose after a cardiac arrest have shown that chilling their entire bodies improves their chances of a favorable neurological recovery. This has led other doctors to try cooling down stroke patients. As with stroke, brain injury in cardiac arrest patients is caused by the interruption of the blood flow to the brain. Currently, doctors are trying to determine how long and to what degree the body should be cooled, and whether the risks of cooling outweigh the benefits in stroke patients.

Endovascular (Embolization) Treatment of Aneurysms

What is the Endovascular treatment of aneurysms?

Coil embolization is an alternative to surgery. This treatment has been offered at Toronto Western Hospital since 1992. This is done in the Neuroangiography suite under fluoroscopy. The Neurointerventional radiologist will make a small incision in the groin through which a tiny catheter is guided through the femoral artery into the brain vessels. The catheter is carefully guided into the aneurysm. Soft platinum coils are deposited through the microcatheter into the aneurysm. When in position, the coil is released by an application of a very low voltage current causing the coil to detach from the pusher wire.

The softness of the platinum allows the coil to conform to the often irregular shape of an
aneurysm. An average of 5-6 coils are required to completely pack an aneurysm. The goal of
this treatment is to prevent blood flow into the aneurysm sac by filling the aneurysm with coils and thrombus. This should prevent aneurysm bleeding or re-bleeding.

Embolization does not repair areas of the brain already injured. The patient will be admitted either the night prior or the morning of the procedure. The treatment is done under a general anaesthetic. A minimum 2-night stay is required after the procedure.

The Procedure

Embolization is not an open surgical procedure and requires specialized training. Most endovascular therapists are neuroradiologists or neurosurgeons who have completed training (ranging from one to two years) in endovascular techniques after their medical (five years) and speciality training (five to seven years).

Before admission
Preadmission will be done one day or two prior to the embolization and routine blood tests may be done. After midnight, no food or drink is allowed.

The Day of the Procedure

After midnight, no food or drink is allowed. You will be taken from the “same day unit” or “preadmission area” to the Neuroangiography suite where the procedure will be performed. Just before the procedure, the nurses will shave one or both groins. Embolization is done under general anaesthesia. After the anaesthetic is administered, a catheter will be threaded up a blood vessel in your groin all the way up into the aneurysm. Very tiny catheters are used. This is a similar procedure to a cerebral angiography except that in addition to dye being injected to show the aneurysm, these tiny catheters are positioned near the aneurysm and platinum coils are inserted into the aneurysm to embolize it.

The length of the procedure is often not predictable, and waiting family members need not to be frightened because a case may takes longer than expected. If the doctors do not think that they can safely embolize the aneurysm, then the embolization procedure will be discontinued.

After Treatment

You will be taken to the Neurosurgical Intensive Care Unit or Step-down Unit where you will be observed closely overnight. Your doctor will instruct you to remain still, lying flat in bed for up to eight hours. This rest period allows the groin artery to heal.

If all goes well, you will be transferred to a neuroscience floor the next day and discharged home the following day. Most patients treated by embolization will also need to return for a follow-up angiogram or magnetic resonance angiogram (MRA), usually performed several months after the treatment to confirm that the outcome of the treatment is stable in time.

What are the Side Effects?
 

The risk of embolization is low. Possible complications include stroke like symptoms such as weakness in one arm or leg, numbness, tingling, speech disturbances and visual problems.Serious complications such as permanent stroke or death are rare.The estimated risk should be discussed with your doctor.

 
Detachable balloon occlusion

Sometimes the size, shape or location of an aneurysm makes coil embolization and surgery impossible. In this case the doctor may choose to block off the parent artery itself. A preliminary test occlusion is often required. A balloon occlusion of the parent artery may be required for an aneurysm at the base of the skull or a very large aneurysm.

A detachable balloon may be placed distal and proximal to the aneurysm. This will permanently close the artery, therefore no blood will reach the aneurysm. The patient is often tested in advance to assure he can tolerate the occlusion of the artery. This is called a balloon test occlusion.

Endovascular Repair of a Descending Thoracic Aortic Pseudoaneurysm Using a Tapered Endoprosthesis

Introduction

Endovascular approaches are being increasingly utilized to treat a variety of thoracic aortic pathologies, including aneurysms, dissections, and transections . Ongoing challenges to endovascular strategies for thoracic aortic pathology include relatively restricted endoprosthesis configurations, lack of FDA-approved devices of appropriate size for the small thoracic aorta, and problems associated with endovascular access. Here we present a case of a descending thoracic aortic pseudoaneurysm treated with a tapered endoprosthesis that illustrates a number of these challenges.

Case Presentation

The patient is a 33 year old male with a history of juxtaductal coarctation who underwent a repair early in infancy. The patient had a recurrence of the coarctation and underwent a second open repair and left diaphragm plication at 2 years of age. He was lost to follow-up until recently when he presented to an emergency room with a several week history of hemoptysis and left back pain. The patient’s physical exam was remarkable only for a well-healed left thoracotomy incision. The patient was afebrile with equal blood pressures in all 4 extremities. The patient’s white count was normal. A CT scan of the chest demonstrated a saccular aneurysm of the proximal descending thoracic aorta measuring approximately 6cm in diameter . The patient was transferred to the Oregon Health and Sciences University for further management.
At our institution a dedicated CT angiogram of the chest was obtained to better define the morphology of the patient’s arch and aneurysm. This confirmed the finding of a saccular aneurysm just distal to the left subclavian artery takeoff. Because of the patient’s prior history of coarctation recurrence and repair, this was felt most likely to represent a pseudoaneurysm, possibly at the site of a patch repair. Aortic reconstructions of the CT angiogram showed no evidence for recurrence of the coarctation . There was, however, a size discrepancy in the diameter of the aorta above and below the aneurysm. The diameter of the aortic arch between the left carotid and left subclavian arteries was 13mm. The diameter of the descending thoracic aorta distal to the aneurysm was 23mm.

Because of the patient’s prior coarctation repairs and the morphology of the pseudoaneurysm, an endovascular repair was felt to be desirable. Based on preoperative measurements of the CT angiogram, a tapered endoprosthesis 9.5cm in length with 16mm proximal diameter and 20mm distal diameter (W.L. Gore & Associates, Inc.), originally marketed as an iliac limb, was selected for use. The patient was taken to the operating room. After induction of general anesthesia, percutaneous right femoral artery access was obtained and a measuring pigtail catheter was advanced into the distal aortic arch. An aortogram was performed which demonstrated the aortic arch and pseudoaneurysm morphology .

At our institution a dedicated CT angiogram of the chest was obtained to better define the morphology of the patient’s arch and aneurysm. This confirmed the finding of a saccular aneurysm just distal to the left subclavian artery takeoff. Because of the patient’s prior history of coarctation recurrence and repair, this was felt most likely to represent a pseudoaneurysm, possibly at the site of a patch repair. Aortic reconstructions of the CT angiogram showed no evidence for recurrence of the coarctation . There was, however, a size discrepancy in the diameter of the aorta above and below the aneurysm. The diameter of the aortic arch between the left carotid and left subclavian arteries was 13mm. The diameter of the descending thoracic aorta distal to the aneurysm was 23mm.

Because of the patient’s prior coarctation repairs and the morphology of the pseudoaneurysm, an endovascular repair was felt to be desirable. Based on preoperative measurements of the CT angiogram, a tapered endoprosthesis 9.5cm in length with 16mm proximal diameter and 20mm distal diameter (W.L. Gore & Associates, Inc.), originally marketed as an iliac limb, was selected for use. The patient was taken to the operating room. After induction of general anesthesia, percutaneous right femoral artery access was obtained and a measuring pigtail catheter was advanced into the distal aortic arch. An aortogram was performed which demonstrated the aortic arch and pseudoaneurysm morphology.

The length of the delivery catheter of the selected tapered endoprosthesis to be used for pseudoaneurysm repair was noted to be 55cm. Based on patient measurements using the right femoral measuring pigtail catheter, it was clear that the endoprosthesis delivery catheter was of insufficient length to allow deployment from the left common femoral artery. A 3cm transverse incision was therefore made over the left external iliac artery. The left external iliac artery was controlled and the patient was heparinized. An 18 Fr sheath was advanced from the left external iliac artery into the distal aorta.

Selective angiography of the left subclavian artery was performed to confirm an intact posterior cerebral circulation. The proximal left subclavian artery was occluded with two 10mm Amplatzer vascular plugs which were introduced via the left external iliac sheath. An angiogram of the distal aortic arch and descending thoracic aorta was then performed to obtain a roadmap of the proximal and distal landing zones . 

The tapered endoprosthesis was passed through the left external iliac sheath, positioned appropriately under fluoroscopic guidance, and deployed. An arch angiogram showed good endoprosthesis placement. Because of the relatively short proximal landing zone length (1cm), a 10 x 40mm Palmaz stent was placed and ballooned to 16mm proximally to achieve good radial fixation. The distal end of the endoprosthesis was ballooned. Completion angiography showed occlusion of the left subclavian artery and exclusion of the pseudoaneurysm .

The patient had an uneventful postoperative course. He had no left arm symptoms. A postoperative CT scan showed good placement of the endoprosthesis and vascular plugs and no endoleak . The patient was discharged to home on postoperative day 2 .

Radiation Safety in Endovascular Brachytherapy

Endovascular brachytherapy (EBT) is a treatment modality to prevent restenosis, which is when after a blood vessel stenosis has been opened by angioplasty, it becomes blocked again. It has been proven that radiation prevents restenosis. Endovascular brachytherapy can be used for cardiac blood vessels and in extremities. In coronary endovascular brachytherapy, sources are inserted into the coronary arteries. These sources have a much lower strength than HDR sources, but radiation safety is still a critical issue in this multidisciplinary endeavour. There are several types of sources used in EBT, such as double-layered balloon catheters with a radioactive coating between the layers, balloon catheters filled with a radioactive liquid or gas and radioactive stents. These sources are generally used for coronary endovascular brachytherapy, but standard remote afterloading devices with gamma-emitting radionuclides can be used for peripheral endovascular brachytherapy. Since irradiation is targeting to parts of the arterial wall to a depth of 0-3 mm, sources are mainly beta ray or low-energy gamma ray radionuclides

Is my treatment lab sufficiently shielded for EBT?

A qualified expert in radiotherapy physics should determine this.

It is common for EBT for coronary arteries to be performed in catheterisation labs, which might not have been initially designed for radioactive materials, but to protect against X radiation. If beta sources are used in the treatment, no room shielding is generally needed but if gamma ray sources are used it is likely that shielding will be needed. In particular, some endovascular treatment of peripheral vessels might be performed using standard HDR brachytherapy equipment, which would necessitate dedicated HDR treatment rooms with high shielding requirements. A qualified expert in radiotherapy physics should be engaged to ascertain the fulfilment of shielding requirements.

How do I know that the source has been placed in the correct location in the patient?

The actual position of the source inside the patient should be verified by fluoroscopy.

A radiation survey outside the patient is not sufficient. If there is a discrepancy between the planned and the actual location that cannot be rectified by further source movement, but by pulling the source back into the delivery device. Before putting the catheter in place, it a visual inspection is needed, also for mechanical integrity using a non-active dummy source. Kinks in the catheter may lead to accidental exposure, as shown in reports of catheter kinks leading to unintended dose distributions in endovascular brachytherapy.

Is there a risk of calculation mistakes leading to unintended absorbed dose?

Yes – you should ensure independent verification of calculations.

As in all radiotherapy, there is a risk of mistakes in the calculation of treatment times. An example of this was reported (IAEA TECDOC 1488) where the diameter of the artery was used for calculation purposes instead of the intended radius, causing a near doubling of the intended absorbed dose to the patient. Endovascular brachytherapy is a discipline where the time between determination of treatment parameters, treatment planning and treatment delivery is very short and, thus, where there is a potential for mistakes being made due to unclear communication. As always, calculations need to be independently verified.

What should I do if the normal return movement of the EBT source fails?

You should follow the local emergency procedure.

It is very important that a local emergency procedure is put in place for this type of emergency situations, already as part of the clinical commissioning of the EBT procedure. This procedure should be well posted, known by staff and tests should be performed.Source return can fail due to breakdown of power backup, failure of mechanics or obstructions in the catheter. The built-in emergency source retraction system should be used to position the source inside the storage container of the delivery device. It is important that persons not directly involved in the emergency procedure leave the room.

What if the emergency source retraction system also fails to retract the source?

You need to manually remove the source from inside the patient.

It should be noted that availability of appropriate emergency containers in the treatment room is always needed –

plastic shielded containers for beta sources and lead containers of appropriate thickness for gamma sources.An emergency procedure is needed, containing the following instructions: Try to locate the source by using X ray fluoroscopy.and remove the catheter from the patient, taking care to avoid touching the catheter near the active source. Use emergency equipment, such as forceps, tongs or tweezers, to move the catheter to the emergency container (which might be handled by another person for practical reasons). It is important that persons not directly involved in the emergency procedure leave the room.