Abstract:
It is an object and advantage of this invention to provide an improved device and method that uses targeted laser wavelength to treat a diseased vessel. An advantage of this invention is targeted ablation of diseased vessels without harming non-target tissue. This new technique allows for a controlled ablation, may not require injection of tumescent anesthesia prior to treatment and may decrease unwanted or unintended side effects.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority under 35 U.S.C. 119(e) to U.S. Provisional Application No. 61/867,627, filed Aug. 20, 2013, which is incorporated herein by reference. 
     
    
     FIELD OF INVENTION 
       [0002]    The present invention relates to a medical device and method for treating blood vessels, and more particularly to a laser treatment device and method for causing closure of varicose veins. 
       BACKGROUND OF INVENTION 
       [0003]    Veins are thin-walled and contain one-way valves that control blood flow. Normally, the valves open to allow blood to flow into the deeper veins and close to prevent back-flow into the superficial veins. When the valves are malfunctioning or only partially functioning, however, they no longer prevent the back-flow of blood into the superficial veins. As a result, venous pressure builds at the site of the faulty valves. Because the veins are thin walled and not able to withstand the increased pressure, they become what are known as varicose veins which are veins that are dilated, tortuous or engorged. 
         [0004]    In particular, varicose veins of the lower extremities are one of the most common medical conditions of the adult population. Symptoms include discomfort, aching of the legs, itching, cosmetic deformities, and swelling. If let untreated, varicose veins may cause medical complications such as bleeding, phlebitis, ulcerations, thrombi and lipodermatosclerosis. 
         [0005]    Traditional treatments for varicosities include both temporary and permanent techniques. Temporary treatments involve use of compression stockings and elevation of the diseased extremities. While providing temporary relief of symptoms, these techniques do not correct the underlying cause that is the faulty valves. Permanent treatments include surgical excision of the diseased segments, ambulatory phlebectomy, and occlusion of the vein through chemical or thermal ablation means. 
         [0006]    Surgical excision requires general anesthesia and a long recovery period. Even with its high clinical success rate, surgical excision is rapidly becoming an outmoded technique due to the high costs of treatment and complication risks from surgery. Ambulatory phlebectomy involves avulsion of the varicose vein segment using multiple stab incisions through the skin. The procedure is done on an outpatient basis, but is still relatively expensive due to the length of time required to perform the procedure. 
         [0007]    Chemical occlusion, also known as sclerotherapy, is an in-office procedure involving the injection of an irritant chemical into the vein. The chemical acts upon the inner lining of the vein walls causing them to occlude and block blood flow. Although a popular treatment option, complications can be severe including skin ulceration, anaphylactic reactions and permanent skin staining. Treatment is limited to veins of a particular size range. In addition, there is a relatively high recurrence rate due to vessel recanalization. 
         [0008]    The use of embolic adhesives is also becoming more popular for treatment of varicose veins. Complications may include revascularization or incomplete vein closure that requires additional follow-up treatments and unwanted migration of the embolic adhesive. 
         [0009]    Thermal ablation treatments, such as radiofrequency or laser energy, are becoming the most typical treatment for varicose veins. Endovascular laser therapy is a relatively new treatment technique for venous reflux diseases. Most prior art methods for laser ablation deliver the laser energy by a flexible optical fiber that is percutaneously inserted into the diseased vein prior to energy delivery. An introducer catheter or sheath is typically first inserted into the saphenous vein at a distal location and advanced to within a few centimeters of the saphenous-femoral junction of the great saphenous vein. Once the sheath is properly positioned, a flexible optical fiber is inserted into the lumen of the sheath and advanced until the fiber tip is near the sheath tip but still protected within the sheath lumen. 
         [0010]    Known methods of thermal ablation using laser energy to treat varicose veins typically use with wavelengths between 810-1470 nm and targets absorption by the hemoglobin and/or water in the blood. As the hemoglobin and/or water in blood begin to rapidly heat as a result of energy absorption this creates a “thermal heat zone” or “heat bubble” inside the vessel. The “thermal heat zone” or “heat bubble” commonly leads to radiant or transient heating of the target zone, usually the inner cell lining of the varicose vein, and additionally non-target, healthy tissue surrounding the diseased vessel. One problem with radiant or transient heating is non-target tissue surrounding diseased vein wall, specifically the vein fascia containing nerves, may absorb the heat energy causing tissue temperature to rise above the pain and cell damage threshold of 45-50 degrees Celsius. This high absorption of energy by non-target tissue in turn causes unwanted symptoms in the patient, including vessel perforation, bruising, nerve damage, skin burns, patient pain, and general discomfort during and after treatment. To limit such symptoms tumescent injections are used prior to treatment. 
         [0011]    Tumescent injections, typically a fluid mixture of lidocaine and saline with or without epinephrine, are administered along the entire length of the great saphenous vein using ultrasonic guidance and the markings previously mapped out on the skin surface. The typical tumescent injection process is time consuming and may take up to 30 minutes to complete. The tumescent injections perform several functions, including pain relief; acting as a thermal barrier between the vein wall and surrounding tissue, and a compressive force to reduce the vein diameter providing better contact with the ablation device. The anesthesia inhibits pain caused from application of laser energy at higher wavelengths to the vein resulting in tissue temperatures to rise above the pain and cell damage threshold of 45-50 degrees Celsius. The tumescent injection also provides a barrier between the vessel and the adjacent tissue and nerve structures, which restricts some of the heat damage to within the vessel. However, this barrier does not prevent all non-target tissue damage. As described in more detail below, an object of the current invention is to eliminate the need for tumescent injections. Further, patients can still experience pain and discomfort from undergoing endovenous laser treatment, especially if the tumescent administered is insufficient. Lastly, the requirement of tumescent anesthesia adds to the economic cost of the overall procedure. 
         [0012]    With some of the prior art treatment methods, contact between the energy-emitting face of the treatment device and the inner wall of the varicose vein is recommended to ensure complete collapse of the diseased vessel. For example, U.S. Pat. No. 6,398,777, issued to Navarro at al, teaches either the means of applying pressure over the laser tip or emptying the vessel of blood to ensure that there is contact between the vessel wall and the fiber tip. One problem with direct contact between the laser fiber tip and the inner wall of the vessel is that it can result in vessel perforation and extravasation of blood into the perivascular tissue. This problem is documented in numerous scientific articles including “Endovenous Treatment of the Greater Saphenous Vein with a 940-nm Diode Laser: Thrombotic Occlusion After Endoluminal Thermal Damage By Laser-Generated Steam Bubble” by T. M. Proebstle, MD, in Journal of Vascular Surgery, Vol. 35, pp. 729-736 (April, 2002), and “Thermal Damage of the Inner Vein Wall During Endovenous Laser Treatment: Key Role of Energy Absorption by Intravascular Blood” by T. M. Proebstle, MD, in Dermatol Surg, Vol 28, pp. 596-600 (2002), both of which are incorporated herein by reference. When the fiber contacts the vessel wall during treatment, intense direct laser energy is delivered to the vessel wall. Conversely, by preventing direct contact between fiber and vein wall the energy is delivered to the vessel wall by indirect or radiant thermal energy from the gas bubbles caused by heating of the blood. Laser energy in direct contact with the vessel wall causes the vein to perforate at the contact point and surrounding area. Blood escapes through these perforations into the perivascular tissue, resulting in post-treatment bruising and associated discomfort. 
         [0013]    Another problem created by the prior art methods involving contact between the fiber tip and vessel wall is that inadequate energy is delivered to the non-contact segments of the diseased vein. Inadequately heated vein tissue may not occlude, necrose or collapse, resulting in incomplete treatment. 
         [0014]    Additionally, most conventional endovenous laser treatments use forward firing lasers which require high power densities to boil or heat the blood, creating bubbles which are necessary for 360 degree circumferential treatment of the targeted vein. High power densities can cause perforations, bruising, nerve damage, thermal damage to non-targeted tissue and other complications causing the patient additional pain. High power densities also cause charring of blood on the fiber tip. 
         [0015]    Therefore, it would be desirable to provide an endovascular treatment device and method that applies lower power density energy directly to the tissue lining the vessel wall which can be uniformly applied to the vessel while avoiding thermal damage to non-targeted tissue. 
         [0016]    It is also desirable to provide an endovascular treatment device and method which protects the optical fiber fom direct contact with the inner wall of vessel during the emission of laser energy to ensure consistent thermal heating across the entire vessel circumference thus avoiding vessel perforation and/or incomplete vessel collapse. 
         [0017]    It is another purpose to provide and endovascular treatment which eliminates the need for tumescent anesthesia thus avoiding the time, pain and cost associated with the administration of tumescent. 
         [0018]    It is another purpose to provide an endovascular treatment device and method which decreases peak temperatures at the working end of the fiber during the emission of laser energy thus avoiding the possibility of fiber damage and/or breakage due to heat stress caused by thermal runaway. 
         [0019]    It is yet another purpose to provide an endovascular treatment device and method which is fast, effective and low in cost enabling the use of existing laser generator capital equipment. 
         [0020]    Various other purposes and embodiments of the present invention will become apparent to those skilled in the art as more detailed description is set forth below. Without limiting the scope of the invention, a brief summary of some of the claimed embodiments of the invention is set forth below. Additional details of the summarized embodiments of the invention and/or additional embodiments of the invention may be found in the Detailed Description of the Invention. 
       SUMMARY OF INVENTION 
       [0021]    According to one aspect of the present invention, an endovascular laser treatment device for causing closure of a blood vessel is provided. The treatment device uses an optical fiber having a core through which a laser light travels and is adapted to be inserted into a blood vessel. A cladding layer is arranged around the core such that the laser energy is maintained within the core. The fiber core may be etched, scored, cut, or otherwise abrasively altered such that slits or grooves are placed into the fiber core. At a distal end portion of the device, the cladding layer may have slits, holes, or openings to expose the core. The power density of the laser energy escaping through the etching of the core and slits of the cladding may be controlled by the variable pitch or surface area of the etches and slits along the ablation zone. It is an object of this invention to provide an energy device capable of 360 degree, side, radial, or circumferential thermal ablation of the blood vessel. The distal end portion of the device may be coaxially surrounded by a sleeve, diffusor, or spacer which aids in the emission of the laser energy as it passes through the slits. 
         [0022]    As described in more detail below, the energy delivery device may provide substantially lower power density emission, as compared to traditional forward firing energy deliver devices currently known in the art. The reduced power density emission is accomplished by increasing the surface area of exposed fiber core through which laser energy may be emitted. The exposed surface area, or ablation zone, is created by removing the cladding and optionally a portion of the core, in a pattern of etches or slits near the distal portion of the fiber. The pattern may include etches which are angled relative to the longitudinal axis of the device and which vary in pitch, width and/or spacing. The reduced power density lowers peak temperatures in the blood vessel and advantageously prevents thermal runaway, unwanted radiate heating to healthy tissue, and device damage. The reduction in power density also reduces the possibility of vessel perforations, prevents bruising, post-operative pain and other clinical complications. 
         [0023]    In another embodiment of the invention, the distal end portion is further coaxially surrounded by a spacer. The spacer may take the form of an expandable member, such as a balloon or arms, a non-expandable member, such as a diffuser cap, or another spacer type element that is intended to keep the ablation zone of the fiber from direct contact with the vein wall. If the spacer is an expandable balloon this may prevent the fiber from coming into direct contact with the blood vessel and aids in the emission of laser energy to evenly treat the vessel wall. The balloon spacer and fiber embodiment includes a dual lumen outer shaft having an inflation/deflation lumen and a lumen sized for passage of the fiber. 
         [0024]    A method for causing closure of a blood vessel is provided. The method involves inserting into a blood vessel an optical fiber having etches in the fiber core and slits or removed cladding layer at a distal portion of the device. Advantageously, the etching and slits enable a controlled power density emission along the ablation zone at the distal end of the fiber. The power density can be controlled so that the modality of treatment is not radiant heating, as currently used in the art by both laser and RF devices, but rather direct and controlled heating of the inner layer of endothelial cells lining the vein wall. The controlled heating of the inner layer of endothelial cells lining the vein wall reduces the possibility of vessel wall perforations and bruising. Therefore, this method may not require the administration of tumescent anesthesia before the procedure. 
         [0025]    A method for causing closure of a blood vessel using a balloon spacer is also provided. In this embodiment, the distal end portion is also surrounded by a balloon, which, when in an inflated state, is in contact with the vessel wall. An outer shaft is inserted into the blood vessel, the outer shaft providing an inflation/deflation lumen and a lumen for passage of the fiber. The inflation/deflation lumen passes a gas or liquid, including but not limited to carbon dioxide gas, to inflate the balloon once the balloon is within the treatment site. When laser energy passes through the slits, the balloon further aids in radial treatment of the blood vessel while preventing the fiber from coming in direct contact with the vessel wall. The administration of tumescent anesthesia is not required in this method. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0026]      FIG. 1  represents a perspective view of the one embodiment of the side-firing fiber optic laser device and laser generator. 
           [0027]      FIG. 2A  is a longitudinal plan view of the distal section of the optical fiber assembly. 
           [0028]      FIG. 2B  is a cross-sectional view of  FIG. 2A  taken along line A-A. 
           [0029]      FIG. 2C  is a cross-sectional view of  FIG. 2A  taken along line B-B. 
           [0030]      FIG. 3  is a partial side view of the distal end of the optical fiber and sleeve prior to manufacture. 
           [0031]      FIG. 4A  is a longitudinal plan view of the distal section of the optical fiber assembly. 
           [0032]      FIG. 4B  is a side view of one embodiment of the distal section of the optical fiber. 
           [0033]      FIG. 4C  is a side view of another embodiment of the distal section of the optical fiber. 
           [0034]      FIG. 5A  is a side view of yet another embodiment of the distal section of the optical fiber. 
           [0035]      FIG. 5B  is a cross-sectional view of  FIG. 5A  taken along line A-A. 
           [0036]      FIG. 5C  is a side view of another embodiment of the distal section of the optical fiber showing helical grooves. 
           [0037]      FIG. 5D  is a side view of another embodiment of the distal section of the optical fiber showing slit grooves. 
           [0038]      FIG. 5E  is a side view of another embodiment of the distal section of the optical fiber showing circular shaped grooves. 
           [0039]      FIG. 5F  is a side view of another embodiment of the distal section of the optical fiber showing longitudinal grooves. 
           [0040]      FIG. 5G  is a side view of another embodiment of the distal section of the optical fiber showing helical shaped grooves with a variable pitch. 
           [0041]      FIG. 5H  is a side view of another embodiment of the distal section of the optical fiber showing annular shaped grooves with a variable groove spacing. 
           [0042]      FIG. 5I  is a side view of another embodiment of the distal end of the optical fiber showing helical shaped grooves with a variable pitch and a sensor. 
           [0043]      FIG. 5J  is an image showing the laser energy being emitted from the distal section of the optical fiber. 
           [0044]      FIG. 5K  is an image showing coagulated blood accumulated on the distal section of the optical fiber after it has been used to ablate tissue. 
           [0045]      FIG. 5L  is an image of prior art forward-firing laser showing coagulated blood accumulated on the distal section of the optical fiber after it has been used to ablate tissue. 
           [0046]      FIG. 6  is a schematic of another embodiment of the device having an expandable member located near the distal section. 
           [0047]      FIG. 7  is a partial side view of the embodiment of  FIG. 6  in a non-deployed state. 
           [0048]      FIG. 8A  is a partial side view of the embodiment of  FIG. 6  in a deployed state. 
           [0049]      FIG. 8B  is a cross-sectional view of  FIG. 8A  taken along line A-A. 
           [0050]      FIG. 8C  is a cross-sectional view of  FIG. 8A  taken along line B-B. 
           [0051]      FIG. 8D  is a cross-sectional view of  FIG. 8A  taken along line C-C. 
           [0052]      FIG. 8E  is an image of the embodiment described in  FIG. 6  showing laser energy being emitted. 
           [0053]      FIG. 9  is a flowchart depicting method steps for performing endovenous laser treatment using one embodiment of the device. 
           [0054]      FIG. 10  is a flowchart depicting method steps for performing endovenous laser treatment using another embodiment of the device. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0055]    The following descriptions and the associated drawings describe exemplary embodiments in the context of certain exemplary combinations of elements and/or functions; it should be appreciated that different combinations of elements and/or functions can be provided by alternative embodiments without departing from the scope of the appended claims. In this regard, for example, different combinations of elements and/or functions than those explicitly described above are also contemplated. 
         [0056]    A first embodiment of the present invention is shown in  FIGS. 1-4C . The endovascular treatment device  1  shown in  FIG. 1  comprises a generator  2 , an optical fiber  3  having a distal portion  12  and a proximal portion  8 , and a proximal connection  7  from the optical fiber to the laser generator. The device may operate in a range of different energy wavelengths, including but not limited to, 200 nm-2500 nm, depending on the laser generator. The proximal connection  7  may have a SMA or similar-type connector, which can be attached to the end of the proximal portion  8  of the fiber  3 . 
         [0057]      FIG. 2A  shows a longitudinal plan view of distal section  12  of the optical fiber of the first embodiment. This embodiment is comprised of a fiber core  5  coaxially surrounded by a cladding layer  10 , and a protective jacket  9  coaxially surrounding the cladding layer  10 . The radial energy emitting section  4  us comprised of the core  5  with etches, a cladding layer  10 , slits  15  of removed cladding, and an outer sleeve  17 . The sleeve  17  may be a fused quartz ferrule or diffuser sleeve used to disperse the laser energy as it passes out of the slits  15 . The sleeve  17  may have a desired length of 5-20 mm from a proximal edge  20  of the sleeve  17  to a distal edge  22  of the sleeve  17 . The proximal edge  20  of the sleeve  17  may abut the distal edge  11  of the jacket  9 . This is where the jacket  9  ends and the sleeve  17  begins. The sleeve  17  has a longitudinal through lumen  18  with an inner diameter so that it can coaxially surround the exposed distal end section  12 , as shown in  FIG. 4B . The distal end  22  of the sleeve  17  may abut the distal tip  19 . The distal tip  19  may be a cap or plug made from similar material as the sleeve  17  and may be attached to the sleeve  17  by various methods, including but not limited to, adhesive, welding, or fusing welded or otherwise attached to the sleeve  17  by known methods in the art. Alternatively, the distal tip  19  may be formed by fusing the distal end of the fiber core  5  with the sleeve  17 , such a technique is described in detail in U.S. application Ser. No. 12/100,309, entitled “DEVICE AND METHOD FOR ENDOVASCULAR TREATMENT FOR CAUSING CLOSURE OF A BLOOD VESSEL”, which is incorporated herein by reference. The distal tip  19  may be a convex shape as shown, or may form various other configurations, such as concave, flat, pointed, or other tip configurations known in the art. A convex distal tip  19  may be advantageous because it may help prevent unwanted vessel perforations or punctures during insertion of the fiber into a tortuous varicose vein. 
         [0058]    As known in the art, cladding  10  is intended to prevent light waves from escaping or being emitted from the core  5 . Light energy travels in the path of least resistance. As light waves travel down the core  5  and encounter the etching of the core  5  and slits  15  of the cladding  10  the waves will begin to escape through the grooves and lists and be emitted into the surrounding vessel. The majority of the light energy will be delivered from the radial energy emitting section  4  because this section of the fiber has the most proximal exposed core surface area which permits light energy to pass through. However, depending on the power of the laser energy and the path of the light waves it is possible that a small percentage of light energy may also be emitted from the distal tip  19 , as shown and described in more detail below. The light escaping from the distal tip  19  is not intended to have the power density sufficient to ablate tissue. Rather it is merely the remaining light energy—which will typically be around less than 5% of the overall light energy—that has not escaped along the radial energy emitting section  4 . 
         [0059]      FIG. 2B  shows a cross-sectional view along line A-A′ of  FIG. 2A  which represents the configuration of the fiber  3  including the core  5 , cladding  10 , and jacket  9 . As disclosed herein, the fiber core  5  may range from 200-1000 microns in diameter. Preferably, the core  5  may be 400 or 600 microns. The cladding layer  10  creates a barrier which the laser energy cannot penetrate, thus causing the energy to move longitudinally through the fiber  3  to a radial energy emitting section  4  of the fiber  3 . The jacket  9  prevents the fiber from breaking during use or during transport. The jacket  9  may also have markings on it as described in more detail below. 
         [0060]      FIG. 2C  represents a cross-sectional view of radial energy emitting section  4  line B-B′ of  FIG. 2A . The radial energy emitting section  4  comprises the core  5  and grooves  14  in core  5 , cladding layer  10  and slits  15  in cladding layer  10 , and sleeve  17 . The cladding layer  10  may have slits  15  or openings. The slits  15  align with the grooves  14  in the core  5 . Grooves  14  are etched into the core  5  using a laser or other known technique in the art. The depth of the grooves  14  may vary depending on the desired resulting power density. It is an intention of this embodiment that the grooves  14  extend toward the central axis of the fiber core  5 . The grooves  14  will generally have a semispherical geometry. The grooves  14  will create a surface in the core  5  so when light energy hits the grooves  14  the angle of refraction created by the grooves  14  permit the light energy to escape. The index of refraction (n) for fused silica glass ranges from 1.4-1.5 in the wavelengths of 800 nm to 2000 nm, respectively. Therefore, the grooves  14  are sized such that the light energy, in the wavelength ranges 800 nm-2000 nm, when refracted creates angles ranging from 40-45 degrees; enabling light energy to escape through the sleeve  17 . 
         [0061]    In one exemplary aspect, the fiber may be a 600 micron fiber, the core  5  may be about 0.600 mm+/−0.010 mm in diameter and the thin cladding layer  10  may have 0.030 mm+0.005/−0.010 mm outer diameter. In another aspect, the fiber may be a 400 micron fiber, the core  5  having a 0.400 mm+/−0.010 mm diameter and a cladding of 0.030 mm+0.005/−0.010 mm. The fiber  3  may be comprised of a silica based core  5  and a polymer cladding layer  10  (e.g., fluoropolymer). In another aspect, the optical fiber  3  may be comprised of a glass core  5  and a glass (e.g., doped silica) cladding layer  10 . For this embodiment, the outer surface of the cladding layer  10  and inner surface of the sleeve  17  may have an interference fit. 
         [0062]    Referring to  FIG. 3 , which shows the components before assembly of the radial energy emitting section  4  of the device  1 , the fiber  3  is shown with the protective jacket  9  partially removed from the distal end  11  the fiber  3 . The sleeve  17 , in this embodiment is made from glass or silica, has an inner lumen  18  which extends from a proximal end  22  to a distal end  20 . Prior to assembly of the fiber and sleeve  17 , the cladding layer  10  is partially removed to form the slits  15  by known methods in the art, and as described below and seen in  FIG. 4A-FIG .  4 C. Once the slits  15  have been formed in the cladding layer  10  the fiber core  5  may then be etched with the desired grooves, as described above. First, removing the cladding  10  to create slits  15  prior to etching the core  5  ensures that the cladding material  10  does not mix or contaminate the core  5  during the etching process. Next, the sleeve  17  is secured to the fiber  3  so that it coaxially surrounds the portion of the fiber  3  having the slits  15 . The proximal end  20  of the sleeve  17  abuts adjacent to the proximal end  11  of the jacket  9 . As discussed above, the distal end  22  of the sleeve  17  is joined together or created into the distal tip  19 . 
         [0063]    Referring to  FIG. 4A-FIG .  4 C, which depicts the distal section of the fiber, the dimensions and geometry of the cladding  10  slits  15  and etching  14  in core  5  may be in any configuration to allow radial emission of laser energy without departing from the scope of the invention. For this embodiment, the dimensions and surface area of the grooves  14  and slits  15  will directly impact the resulting power density along the radial energy emitting section  4 . For example, the resulting power density along the radial energy emitting section  4  can be controlled by altering and customizing the size, placements and number of slits  15 . By way of example, the total slit length  15 A, slit width  15 B, the pitch of the slits relative to the longitudinal axis of the fiber may be varied to form unique slit patterns designed to deliver optimal energy densities along the treatment zone. Adjusting the overall dimension and geometry of the slits  15  will directly impact the amount of light energy leakage or radial light energy dissipation, power density delivered along treatment section, direction of light energy, and power density that will escape from distal end  19  of the fiber  3 . The double helical configuration of the slit length  15 A, as seen in  FIG. 4A , may ensure a radial or complete and even 360 degree treatment of the vessel. A double helix slit  15  configuration consists of two congruent helices with the same axis that differ by translation along the axis. 
         [0064]      FIGS. 4B and 4C  show the distal end section  12  of the fiber with alternative slit  15  configurations from the previous embodiment. The jacket  9  has been removed and slit  15  pattern is created before the sleeve  17  is attached. The radial energy emitting section  4  of  FIG. 4B  shows a spiral or cork-screw slit configuration, while the radial energy emitting section  4  of  FIG. 4C  depicts a zigzag or triangle pattern of slits  15 . The slits  15  may be formed using various techniques. For example, one method of creating the slits  15  is to remove only sections of the cladding  10  along the distal end, as seen in  FIG. 4B-4C . The slits  15  may take may different forms and patterns, including but not limited to, helical, spiral, radial, circular, zigzag, wedge-shaped or dotted. 
         [0065]    Referring now to  FIG. 5A-5B , another embodiment of the device is shown. A related problem with endovascular laser treatment of varicose veins using a conventional fiber device is fiber tip damage during laser energy emission caused by localized heat build up at the working end of the fiber, which may lead to thermal runaway. Thermal runaway occurs when temperature at the fiber tip reaches a threshold where the core and/or cladding begin to absorb the laser radiation. As the fiber begins to absorb the laser energy it heats more rapidly, quickly spiraling to the point at which the emitting face begins to burn back like a fuse. One cause of the heat build up is the high power density at the emitting face of the fiber. A conventional fiber includes a cladding layer immediately surrounding the fiber core. Laser energy emitted from the distal end of the device may create thermal spikes with temperatures sufficiently high to cause the cladding layer to burn back. By removing the cladding  10  for a selected distance from the distal end of the core  5 , the possibility of burn back of the cladding  10  is eliminated. In this embodiment the cladding layer  10  may be completed removed from distal section of core  5 . Grooves  14  are then etched directly into the core  5  at variable pitches. The grooves  14  may be etched into the core  5  using a laser or other known technique in the art. The depth and pitch of the grooves  14  may vary depending on the desired power density. It is an intention of this embodiment that the grooves  14  extend toward the central axis of the fiber core  5 . As shown in  FIG. 5B , which represents a cross-sectional view along line  10   a  in  FIG. 5A , the grooves  14  may generally have a semispherical geometry. 
         [0066]    After the grooves  14  have been etched into the core  5 , an outer cap  16 , which may be made from glass or fused silica similar to the sleeve described above, is placed over the core  5  and attached to the jacket  9  using an adhesive or other known method in the art. The outer cap  16  gives the fiber  3  a convex distal tip  19 . This convex shaped tip  19  helps ease the advancement of the fiber. The outer cap  16  is sized such that there is a space between the outer cap  16  and core  5  creating an air gap  23  around the distal end of core  5 . The light energy remains inside the fiber core  5  as a result of the cladding layer  10  and the air gap  23  which acts as an additional cladding layer only for the section of core  5  that does not have any grooves  14 . The light energy remains inside the fiber core  10  as a result of the cladding layer  10  and the air gap  23  which acts as an additional cladding layer. 
         [0067]    The air gap  23  will be present and fill this void as seen in  FIG. 5B , representing a cross-sectional view of  FIG. 5A  taken along line A-A. In this embodiment, air will have a lower refractive index than the outer cap  16 . For example, the outer cap  16  may be comprised of a fused silica or other glass material that has a similar index of refraction as the core  5 . The air gap  23  functions as an additional or secondary cladding layer. The grooves  14  cause a void along the smooth surface of the core  5 . The voids provide a necessary interface that will expel the light waves from the core  5  through the air  23  and subsequent cap  16 . The voids introduce sharp angled surfaces into the core  5  that will be able to surpass the critical angle established by the indices of refraction of the interface between the air  23  and core  5  that would have otherwise been unachievable. Some light waves will hit the grooves  14  at an angle less than the critical angle for total internal reflection to occur. The critical angle of incidence is a function of the indices of refraction for the two materials at the interface; in this case, the two materials are core  5  and air  23 . Once outside the core  5 , the light waves are able to be transmitted through the outer cap  16  because its index of refraction is higher than that of the air gap  23  which prevents total internal reflection. 
         [0068]    The outer cap  16  may also has concave  27  shape along its inner wall at its distal end. The inner wall concave shape  27  may facilitate reflection of any remaining forward emitting light back through the core  5 . As the laser energy travels down the fiber  3  toward the distal tip  19 , the small percentage of forward firing light energy will reach the concave shape  27  and reflect the light back towards the core  5  and thereby reduce the amount of light passing through the distal tip  19  of the outer cap  16 . 
         [0069]    It is an advantage of this invention that the power density of the laser energy emitted along the radial energy emitting section  4  can be precisely controlled using variable pitches of the grooves  14 . It is intended that this device will have a lower overall power density that what is currently used in forward firing lasers in the art but still have enough power density to cause thermal death to the inner cell wall of the target vein. The purpose of lowering the overall power density is to prevent unwanted vessel wall perforations or unwanted radiant heating that damages healthy tissue surrounding the target vessel. Currently tumescent anesthesia is used in part to act as a heat barrier between the energy device and the healthy surrounding tissue to decrease this unwanted radiant heating of non-targeted tissue. This device may solve the problem of unwanted radiant heating and not require the use of tumescent by controlling the amount of power density and light escaping the fiber along the radial energy emitting section  4 . 
         [0070]    By controlling the groove  14  pitch, groove size, groove  14  depth, groove  14  surface area and number of the grooves  14  along the radial energy emitting section  4  it will be possible to control and/or customize the power density of the emitted light energy along the entire length of the radial energy emitting section  4 . Light energy travels in the path of least resistance so the amount of energy that is released along the radial energy emitting section  4  through the proximal edge  24  of the radial energy emitting section  4  is generally greater than the energy being released at the distal edge of the slits  26 , for any given uniform slit pattern. In other words, there will be less available light energy to escape through the grooves  14  closer to the distal edge  26  of the radial energy emitting section  4 . By varying the spacing, pitch, and other slit pattern characteristics, the energy emitted along the length of the emitting section  4  can be controlled. The proximal edge  24  of the radial energy emitting section  4  has grooves  14  that are spaced apart and few in number. As the groove  14  pitch moves towards the distal edge  26  the grooves  14  and pitch will become more numerous and closer together with a steeper pitch. The reason for increasing number of grooves  14  towards the distal edge  26  is to allow the maximum available light energy to escape in an effort to equalize the amount of light energy escaping along the radial energy emitting section  4 . It is an intention of this device that the power density along the length of the radial energy emitting section  4  will be equal and sufficient enough to generate heat in the range of the 45-50 C at the vessel wall, the cell death threshold, but insufficient to cause unwanted radiant heating of non-target tissue, and thereby eliminating or minimizing the need for tumescent anesthesia. 
         [0071]    The grooves  14  may be configured in any configuration stated above, but in this embodiment they are helical and have a groove pattern length  15 A of approximately up to 15 mm. Furthermore, the groove pattern length  15 A is comprised of a first or proximal zone  31 , a second or intermediate zone  32 , and a third or distal zone  33 . The three zones preferably divide the groove length  15 A into three equal sections. The zones are created to release a uniform radial band of laser energy. Therefore the grooves  14  will be configured so that the energy output of the first zone will equal the energy output of the second zone which will equal the energy output of the third zone  33 . As seen in  FIG. 5A , the number of grooves  14  may increase from the first zone  21  to the third zone  33 , thereby controlling the power density of the laser energy being emitted. The first zone  31  may have the least number of grooves  14  to prevent the majority of the laser energy from escaping and to facilitate more laser energy traveling further down the fiber  3 . The second zone  32  may have a greater number of grooves  14  than there are in the first zone  31 , but a lesser number of grooves  14  than there are in the third zone  33 . The third zone  33 , which is close to the distal most tip  19 , has more grooves  14  than either the first  31  or second  32  zone to allow the remaining amount laser energy to escape. In a similar manner, the steepness of the pitch in the slit pattern may be varied from shallowest at the proximal zone  31  to the steepest at the distal zone  33 . The remaining light energy that has not escaped through any of the zones may be reflected back towards the fiber core  3  due to the concave shape  27  of the outer cap  16 , as described above. 
         [0072]    The laser generator may generate up to 10 Watts of laser energy, In one embodiment using 5 Watts of power about less than 0.5 Watts of the laser energy will be emitted from the distal tip  19  which results in approximately 4.5 Watts of laser energy that will uniformly and radially be emitted from the radial energy emitting section  4 . However, if desired, the amount of laser energy that is released out of the distal tip  19  can be increased by removing the concave distal end  27  from the outer cap  16 , changing the angle of the reflective surface  27  or by changing the configuration of the grooves  14 . 
         [0073]    As shown in  FIGS. 5C-5H , various other embodiments of the radial energy emitting section  4  are shown. These various embodiments of the different type of radial energy emitting section  4  are intended to be used with the device embodiment previously described and shown in  FIG. 5A . For clarity purposes only  FIGS. 5C-5H  only depict the fiber core  5  with grooves  14 , however it is intended that the other device components described and shown in  FIG. 5A  would be combined. Referring to  FIG. 5C , the grooves  14  are etched into the core  5  in a double helix pattern. A double helix groove  14  configuration consists of two congruent helices with the same axis that differ by translation along the axis. Referring to  FIG. 5D , the grooves  14  are etched into the core  5  in a slit or half-moon pattern. In this embodiment the individual grooves  14  may not extend fully around the core  5 . Referring to  FIG. 5E , the grooves  14  are etched into the core  5  in a dot pattern. Referring to  FIG. 5F , the grooves  14  are etched into the core  5  in a longitudinal triangular or wedge pattern. 
         [0074]    Referring to  FIG. 5G-FIG .  5 H, the grooves  14  are etched into the core  5  in a variable pitch pattern. Here, the grooves  14  of the first zone  31  are in a double helix pattern. The grooves  14  of the second zone  32  are also in a double helix pattern but are closer together with a steeper pitch than the grooves  14  of the first zone  31 . The grooves  14  of the third zone  33  are also in a double helix pattern and are closer together and more in number than that of the second zone  32 . Also, a first space  31   a  is between the first zone  31  and second zone  32 , and a second space  32   a  is between the second zone  32  and third zone  33 . It is understood that the type of groove  14  pattern may differ depending on the desired resulting power density. For example, the first zone  31  may be a double helix, as shown in  FIG. 5E , however it is conceived that the second zone  32  groove  14  pattern may be that of slits, as seen in  FIG. 5D , and the third zone  33  groove  14  pattern may be a single helix or cork-screw, as seen in  FIG. 5A . Referring to  FIG. 5H , of the groove  14  pattern for the variable pitch may be circular around the axis of the core  5 . 
         [0075]    In yet another patter (not shown), it may be possible to have multiple radial energy emitting sections along the length of the device. For such an embodiment sections of the cladding layer may be removed and the exposed core may have grooves etched in any of the patters previously described. The advantage of having multiple radial energy emitting sections along the length of the device is that the treatment time may be reduced because the amount of treatment zones that can have energy delivered will increase. 
         [0076]    As seen in  FIG. 5I , another embodiment of the device is shown. In this embodiment, the device comprises of a core  5  with a radial energy emitting section  4  having varying pitch grooves  14  as described in  FIG. 5G  above. This embodiment also has a sleeve  17  coaxially aligned with and secured to the fiber. The sleeve  17  may be made of similar material as described in previous embodiments above, such as glass or fused silica. The distal most end  102  of the sleeve  17  may be a selected distance proximal from the distal most end  100  of the core  5 . A sensor  103  may be securely attached to the distal most end  100  of the core  5 . An electrical wire  101  may be connected to the sensor  103  and extend back towards the generator (not shown). The purpose of the sensor  103  in this embodiment is to measure the amount of light energy escaping from the front of the core  5  and not escaping from the radial energy emitting section  4 . The sensor  103  may measure temperature of the core  5 , light wavelengths, light energy, or the temperature of surrounding fluid or tissue. An example of such a sensor  103  is a photodiode sensor used to measure optical power. By measuring the optical power being delivered from the front of the device, and knowing the total wattage being used, it is possible to equate what percentage of the laser energy is being delivered through the radial energy emitting sections  4 . An advantage of using a sensor  103  to measure the optical power escaping from the front of the device is that the power wattage may be adjusted to ensure that proper laser energy is being emitted from the radial energy emitting sections  4 . The sensor may communicate with a processor within the laser generator which may include an algorithm, or other software component, that can automatically change (either lower or higher) the wattage being delivered to the fiber based on the feedback and information received from the sensor  103 . For example, if the sensor  103  is measuring optical power that indicates the light energy delivered by radial energy emitting sections  4  is lower than the power density threshold sufficient for cell death then the system may automatically increase the wattage until the desired power is measured. Therefore, the sensor  103  may act as a feedback mechanism sending information to the generator that can be calculated and the power or wattage may then automatically change (i.e., increased or decreased) depending on the information received. In yet another embodiment, there may be an adjustable second cladding sleeve which can be coaxially advanced or retracted to expose or cover portions of the slits or grooves. This embodiment allows for a single product to be adjusted based on the needs of the clinical users. Advantageously, this allows a manufacturer to produce less inventory and thereby reduce overall product manufacturing costs. 
         [0077]    As shown in  FIG. 5J , is an image of the light energy being emitted by the device of the embodiment shown in  FIG. 5A . The image shows the majority of the light energy being emitted by the radial energy emitting sections  4 , as can be seen by the intensity and brightness of this light. The picture also shows that only a small amount of the light energy is being emitted in a forward direction  4   a , as can be seen by the low intensity and dullness of this light. 
         [0078]    As shown in  FIG. 5K , an image of the distal section of the device, as described in previous embodiment  FIG. 5A , after it has been used to treat a blood vessel. The fiber  3  and distal portion of sleeve  17  show little to no coagulated blood indicating that any light energy escaping through these portions was not sufficient to thermally induce coagulation and cause cell death. The majority of the clotted blood  105  is shown over the portion of the device that is the radial energy emitting section. This indicates that the power density of the light energy delivered by the radial energy emitting sections  4  was sufficient to thermally induce coagulation and cause cell death.  FIG. 5L  shows a device currently known in the prior art and is a forward firing laser. The fiber  3  and sleeve  17   a  of a forward firing device has no blood accumulation because no light energy escapes. However, a large amount of coagulated blood  107  can be seen at the distal most end of the sleeve  17   a , indicating the majority of the power density is being delivered in a forward direction. 
         [0079]    Referring to an alternative embodiment as shown in  FIGS. 6-8D , the device  1  may be provided with a spacer  120 . Spacer  120  may be expandable, such as an inflatable balloon, expandable basket, expandable arms, cage with expandable arms or non-expandable element, such as an outer ferrule, or a diffuser cap as known in the art. 
         [0080]    The spacer  120  of this embodiment may be a balloon and may be made out of PTFE, latex or other similar material well-known in the art to make medical grade balloons. The spacer  120  is comprised of a body  122 , a distal tapering cone  126 , a proximal tapering cone  121 , and a distal neck  123 . In the deployed state, an outer wall of the spacer  120 A ( FIG. 8C ) at the body  122  of the spacer  120  is in contact with a vessel wall  50 . When the spacer  120  is deployed, the slit configuration  15  may be centered within the vein lumen. 
         [0081]      FIG. 6  shows the embodiment with a balloon spacer  120  comprising the radial light emitting section  15  of the optical fiber  3  and an outer shaft  34  having a hub  30 . The hub  30  may further comprise a homeostasis valve  35 , a side arm or Y-connector  38 , a stopcock  40 , and a through-lumen  36  for insertion and passage of the optical fiber  3  to the outer shaft  34 . The outer shaft  34  terminates with the balloon body at the distal tip  37 . The side arm  38  is in communications with the inflation/deflation lumen  115  positioned within outer shaft  34  and terminating within the balloon body. 
         [0082]    As used herein, the outer shaft  34  can be a sheath, dilator or any other tubular device designed to aid in insertion and advancement of the optical fiber  3  through a blood vessel. The homeostasis valve  35  is a passive one-way valve that prevents the backflow of blood from the through-lumen  36  while simultaneously allowing the introduction of fibers, guidewires, and other interventional device to the outer shaft  34 . The valve  35  is located within the lumen  36  of the hub  30 . The valve  35  is made of elastomeric material such as a PTFE or silicone, as commonly found in the art. The valve  35  opens to allow insertion of the fiber  3  and then seals around the inserted fiber  3 . However, the valve  35  does not open in response to pressure from the distal side of the device in order to prevent back-flow of blood or other fluids. The valve  35  also prevents air from entering the outer shaft  34 . 
         [0083]    The stopcock  40  and side arm tubing  38  provide multiple fluid/gas paths for administering optional procedural fluids and gases during a treatment session as described in more detail below. The stopcock  40  may be a three-way valve with a small handle (not shown) that can be moved to alter the fluid/gas path. The position of the handle controls the active fluid/gas path by shutting off the flow from one or both ports of the stopcock  40 . 
         [0084]    The fiber  3  runs coaxially within the through-lumen  36  of the outer shaft  34 . During manufacture, the fiber is permanently bonded to the hub  30  using an adhesive or other known technique. Advantageously, the adhesive secures the fiber  3  to the hub  30  so that there can be no independent movement of the fiber  3  relative to the outer shaft  34  during use. When the fiber  3  is inserted through the outer shaft  34  and fiber  3  is bonded to the hub  30 , the laser treatment device is in a locked operating position. In that operating position, the fiber tip  19  extends past the distal tip  37  of the outer shaft  34  by a set amount to expose the distal end section  12 . The tip  37  ends within the balloon spacer  120  so that it allows carbon dioxide gas to pass through the inflation/deflation lumen  115  from the side-arm lumen  38  where the administration of the carbon dioxide gas is controlled by the stopcock  40 . 
         [0085]    Referring to  FIGS. 7-8C , the method of using the above endovascular device embodiment is shown. If the spacer  120  is a balloon, then gas, including but not limited to C 02 , would likely be used to inflate the balloon because the gas will not lower the energy as light travels through the slits  15  and towards the vein walls. A key aspect of this embodiment is that laser energy is intended to be delivered as close to the inner vessel wall as possible with the lowest amount of power loss possible. Using carbon dioxide gas instead of fluid, such as saline solution, may be advantageous because the laser energy will travel through gas without being absorbed. The laser energy will emit through the sides of the balloon that are in contact with the vessel wall. Carbon dioxide is a safe inflation mass because it is regularly removed by the human body, so if the balloon  120  were to rupture the carbon dioxide could be naturally removed from the body. The expandable spacer  120  is attached or connected onto the outer shaft  34  at proximal bond point  124  and to the sleeve  17  at distal bond point  125 . 
         [0086]    The outer shaft  34  may be a dual lumen catheter having an inflation/deflation lumen  115  and a second lumen sufficient for passage of the fiber  3  as shown in  FIG. 8B , which depicts a cross-sectional view along line A-A′ in  FIG. 8A . The fiber  3  is shown positioned inside vessel  50 . The device is comprised of an outer shaft  34  including an inflation lumen  115  positioned within the wall of the shaft  34 . Within the fiber lumen is shown the components of the fiber; the jacket  9 , cladding  10  and core  5 .  FIG. 8C  represents a cross-sectional view along line B-B′ where the core  5  is coaxially surrounded by a portion of the cladding  10  having no slits and core  5  having no grooves. At this point, the cladding  10  is surrounded by the glass sleeve  17  instead of the protective jacket  9 , which has been removed from this section of the fiber. The glass sleeve is coaxially surrounded by the inflated balloon  120  which touches the wall of the vein lumen  50 . 
         [0087]      FIG. 8D  represents a cross-sectional view along the line C-C′ at the midpoint of the balloon body  122 . Here, the laser energy escapes from the core  5  through the grooves  14  and the slits  15  in the cladding. The laser energy travels through the glass sleeve  17  and the CO2 in the balloon  120  with little to no loss in power density because neither sleeve  17  nor CO2 will absorb the light wavelength. The laser energy will be absorbed by the vessel wall  50  which is in contact with the outer wall of the balloon  120 A. An advantage of this embodiment is that a large percentage of power density is being directly absorbed by the vessel wall  50  because neither the sleeve  17  nor CO2 absorb the light wavelength. This means that the device does not need to deliver as high a power density as forward firing lasers or radial lasers in the art which rely on radiant heating (i.e., heating the blood first and this heat energy is the transferred to the vein wall). 
         [0088]    As shown in  FIG. 8E , an image of the embodiment described above and shown in  FIGS. 6-8D . The image shows the radial energy emitting section  4  emitting laser energy while the balloon spacer  122  is inflated. 
         [0089]    Methods of using the optical fiber device for endovenous treatment of varicose veins and other vascular disorders will now be described with reference to  FIG. 9 , which illustrates the procedural steps associated with performing endovenous treatment using the optical fiber device  1 . To begin the procedure, the target vein is accessed using a standard Seldinger technique well known in the art. Under ultrasonic guidance, a small gauge needle is used to puncture the skin and access the vein. A 0.018 inch guidewire is advanced into the vein through the lumen of the needle. The needle is then removed leaving the guidewire in place. 
         [0090]    A micropuncture sheath/dilator assembly is then introduced into the vein over the guidewire. A micropuncture sheath dilator set, also referred to as an introducer set, is a commonly used medical kit, for accessing a vessel through a percutaneous puncture. The micropuncture sheath set includes a short sheath with internal dilator, typically 5-10 cm in length. This length is sufficient to provide a pathway through the skin and overlying tissue into the vessel, but not long enough to reach distal treatment sites. Once the vein has been accessed using the micropuncture sheath/dilator set, the dilator and 0.018 inch guidewire are removed, leaving only the micropuncture introducer sheath in place within the vein. A 0.035 inch guidewire is then introduced through the introducer sheath into the vein. The guidewire is advanced through the vein until its tip is positioned near the sapheno-femoral junction or other starting location within the vein. 
         [0091]    After removing the micropuncture sheath, a treatment sheath/dilator set is advanced over the 0.035 inch guidewire until its tip is positioned near the sapheno-femoral junction or other reflux point. Unlike the micropuncture introducer sheath, the treatment sheath is of sufficient length to reach the location within the vessel where the laser treatment will begin, typically the sapheno-femoral junction. Typical treatment sheath lengths are 45 and 65 cm. Once the treatment sheath/dilator set is correctly positioned within the vessel, the dilator component and guidewire are removed from the treatment sheath. 
         [0092]    The optical fiber assembly  1  is then inserted into the treatment sheath lumen and advanced until the fiber assembly distal end is flush with the distal tip of the treatment sheath. A treatment sheath/dilator set as described in U.S. Pat. No. 7,458,967, incorporated herein by reference, may be used to correctly position the protected fiber tip with spacer assembly  1  of the current invention within the vessel. The treatment sheath is retracted a set distance to expose the fiber tip, typically 1 to 2 cm. If the fiber assembly has a connector lock as described in U.S. Pat. No. 7,033,347, also incorporated herein by reference, the treatment sheath and fiber assembly are locked together to maintain the 1 to 2 cm fiber distal end exposure during pullback, as seen in  FIG. 6 . 
         [0093]    At this time, prior art methods require the administration of tumescent anesthesia along the vein, which can take up to 30 minutes. The present invention emits laser energy radially, directing the energy to the vessel wall and as a result, only requires a low power density, which eliminates perforations and thermal damage to surrounding tissue and nerves. Therefore the present invention may not require the administration of tumescent anesthesia. However, if tumescent is required then the physician may inject at this time. 
         [0094]    Once device  1  has in proper treatment position relative to the sapheno-femoral junction, the laser generator  2  is turned on and the laser light enters the optical fiber  3  from its proximal end via the proximal connection to the laser generator  7 . While the laser light is emitting laser light through the distal end section  4 , the treatment sheath/fiber assembly is withdrawn through the vessel at a variable rate, ranging at 50-80 J/cm for 2-3 millimeters per second, and also depending on the size of the vessel being treated. Alternatively, in another embodiment of the method the physician may withdraw the sheath/fiber assembly in a pulsed manner. The laser energy travels along the optical fiber  3  through the slits  15  and into the vein lumen where the laser energy is uniformly delivered radially to heat the vein wall, thus damaging the vein wall tissue, causing cell necrosis and ultimately causing collapse/occlusion of the vessel. Forward firing of the lasers which require high power densities to boil or heat the blood, creating bubbles which are necessary for 360 degree circumferential treatment of the targeted vein. High power densities can cause perforations, bruising, nerve damage, thermal damage to non-targeted tissue and other complications causing the patient additional pain. High power densities also cause charring of blood on the fiber tip. Advantageously, the method of using this invention does not require high power density in a forward firing direction and therefore these risks are diminished or removed from the treatment. 
         [0095]    The outer jacket  9  of fiber  3  may include visual markings/markers. Markings are used by the physician to provide a visual indication of insertion depth, tip position and speed at which the device is withdrawn through the vessel during delivery of laser energy. The markings may be numbered to provide the physician with an indication as to distance from the distal end section of the fiber  12  to the access site during pullback. The markings may be positioned around the entire circumference of the fiber shaft or may cover only a portion of the shaft circumference. 
         [0096]    Once the targeted tissue is treated, the laser generator  2  is turned off. The procedure for treating the varicose vein is considered to be complete when the desired length of the great saphenous vein has been exposed to laser energy. Normally, the laser generator is turned off when the fiber tip  19  is approximately 3 centimeters from the access site. The combined sheath/endovascular laser treatment device  1  is then removed from the body as a single unit. 
         [0097]    Prior art methods provide a cladding that does not have slits therethrough and thus delivers laser energy via an emitting face at the distal tip of the fiber which causes charring and blood build-up on the tip. By emitting laser energy through the slits  15 , the device provides radial treatment and reduces the laser energy emitted out of the distal tip  19 . Because minimal energy is emitted from the distal tip  19 , treatment using the present invention does not result in charring. 
         [0098]    Methods of using the optical fiber device with balloon spacer for endovenous treatment of varicose veins and other vascular disorders will now be described with reference to  FIG. 10 , which illustrates the procedural steps associated with performing endovenous treatment using this embodiment of the optical fiber device  1 . Using much of the same steps as the previous method, the optical fiber  3  is inserted and advanced to the treatment location with a balloon  120  in the deflated position as shown in  FIG. 8A . If tumescent anesthesia is required, the physician should administer it after the fiber has been advanced to the treatment location. However, the hub  30  and catheter  34  enable the filling of the balloon  120  via the stopcock  40  and side-arm  38  which defines the inflation deflation lumen  115 . Prior to activating the laser generator, the balloon  120  is deployed by injecting inflation gas through the inflation lumen  115  into the balloon  120  as shown in  FIGS. 7-8A . As the gas fills the balloon  120  it expands and the outer wall of the expandable member  120  contacts the inner vessel wall  50  centering the radial energy emitting section  4  within the vein lumen. The deployed balloon  120  maintains the position of the distal end section  12  of the fiber  3  within the vein lumen and out of contact with the vessel wall. 
         [0099]    In this embodiment, markings can be placed on the catheter  34  instead of jacket  9 , as in the previous embodiment so that the physician can measure the rate at which the fiber  3  is being pulled back. The catheter  34 /fiber  3  assembly is slowly withdrawn together through the vein. The connection between the fiber connector  31  and hub connector  32  ensures that the distal end section  4  remains exposed beyond the catheter tip  37  by the recommended length for the entire duration of the treatment procedure. Once treatment is complete, the expandable member  120  is deflated and device is removed. This embodiment has the ability to inflate and/or deflate as the device is moved through the vessel to accommodate varying diameter vein segments. 
         [0100]    As may be recognized by those of ordinary skill in the pertinent art, blood vessels other than the great saphenous vein and other hollow anatomical structures can be treated using the device and/or methods of the invention disclosed herein. 
         [0101]    The above disclosure is intended to be illustrative and not exhaustive. This description will suggest many modifications, variations, and alternatives that may be made by those of ordinary skill in this art without departing from the scope of the invention. Those familiar with the art may recognize other equivalents to the specific embodiments described herein. Accordingly, the scope of the invention is not limited to the foregoing specification.