referring to the drawings , a preferred embodiment of the valvulotome device according to the present invention is illustrated and generally indicated as 10 in fig1 - 16 . the valvulotome device 10 comprises bifurcated assembly 12 operatively associated with a handle 14 through a catheter wire 16 encased inside the lumen of a flexible catheter 17 . the bifurcated assembly 12 provides a means for cutting valves in a vein of a patient as well as a guide means for maintaining the cutting means in a continual centralizing , self - alignment within the lumen of the vein when operated by the handle 14 . referring to fig2 a and 3 , the bifurcated assembly 12 comprises a hollow conduit member 18 joined between a distal portion 20 having a cutter head 24 including a plurality of retractable , radially oriented cutting blades 28 and proximal portion 22 having a guide head 26 including a plurality of retractable , radially oriented guide fins 30 . the distal portion 20 defines a first chamber 50 in communication with a plurality of slots 84 ( fig4 a ) defined around the cutter head 24 adapted to permit each cutting blade 28 to extend radially outward , while the proximal portion defines a second chamber 52 that communicates with the first chamber 50 through a passageway 54 defined by conduit member 18 . similarly , second chamber 52 communicates with a plurality of slots 86 ( fig4 a ) which permit the guide fins 30 to extend radially outward from the guide head 26 . the catheter wire 16 is received within the bifurcated assembly 12 at the proximal portion 22 through the first chamber 50 and passageway 54 , before terminating inside second chamber 52 . in addition , the catheter 17 is operatively associated with a swivel component 23 disposed inside the second chamber 52 . referring to fig5 , each cutting blade 28 comprises a blade body 82 extendable through the slot 84 defined by cutter head 24 and a blade end 80 disposed inside the first chamber 50 . the blade end 80 is pivotally attached to a rearward part of the cutter head 24 and defines a channel portion 88 , while the blade body 82 terminates in a formed free end 90 . as further shown in fig5 a , the blade body 82 defines a long flat bottom edge 96 , ending in a formed free end 90 where there is a sharp edge 98 that is adapted for cutting valves of a vein . referring back to fig3 , the guide head 26 preferably includes a set of four guide fins 30 radially disposed equidistantly around the proximal portion 22 with each guide fin 30 having a guide body 94 extending through slot 86 and disposed inside second chamber 50 . the guide end 92 is pivotally attached to a rearward part of proximal portion 20 . similar to the cutting blade 28 , each end 92 defines a channel portion 89 , while the guide body 94 terminates in a formed free end 91 . the catheter wire 16 defines a distal terminal end 100 operatively engaged with a first wedge member 32 moveably disposed inside the proximal portion 20 . referring to fig1 , the first wedge member 32 comprises a wedge body 40 and a stem 72 with wedge member 32 being movable within the first chamber 50 and adapted to engage the long flat bottom edge 96 of the blade body 82 when the catheter wire 16 is manipulated by handle 14 as shall be discussed in greater detail below . preferably , the wedge body 40 includes a set of opposing four - sided depression portions 66 and has the general appearance of a maltese cross , although other suitable configurations that fall within the scope of the present invention are contemplated . the manipulation of the catheter wire 16 by handle 14 causes the first wedge member 32 to move which engages the long flat bottom edge 96 of each cutting blade 28 with each respective peak 67 of first wedge member 32 . since the first wedge member 32 has a slightly greater diameter than the long flat bottom edge 96 of each cutting blade 28 this structural arrangement permits the wedge member 32 to gradually push each cutting blade 28 outwardly through slot 84 as illustrated in the sequence of fig4 a , 4b and 4 c . in fig4 a , the cutting blades 28 are fully retracted inside first chamber 50 , while in fig4 b the moving engagement of the first wedge member 32 against each cutting blade 28 causes the blades 28 to extend through each slot 84 . as such , the incremental advancement of the first wedge member 32 in relation to each cutting blade 28 effectively changes the degree to which the blade 28 emerges above the surface of the cutter head 24 from first chamber 50 into a cutting position as the first wedge member 28 moves along the long flat bottom edge 96 of each blade 28 as shown in fig . 4c . in operation , each cutting blade 28 acts as a spring so that once the force from the first wedge member 32 is removed each cutting blade 28 returns to the originally fully retracted position inside the first chamber 50 ( fig4 a ). by this structural arrangement , the effective cutting diameter of the cutting blades 28 can be adjusted by the handle 14 through manipulation of the catheter wire 16 in a forward and backward movement with respect to bifurcated assembly 12 . as illustrated in fig1 and 15 a , the effective cutting diameter of the cutting blades 28 in the fully retracted position and the fully expanded position are shown . preferably , the cutter head 24 includes a set of opposing four - sided depression portions 66 and has the general appearance of a maltese cross , although other suitable configurations that fall within the scope of the present invention are contemplated . fig1 and 16 a illustrate the effective diameter of the guide fins 30 in the fully retracted position and the fully expanded position . preferably , the guide head 26 includes a set of opposing four - sided depression portions 66 and has the general appearance of a maltese cross , although other suitable configurations that fall within the scope of the present invention are contemplated . similarly , second wedge member 34 is operatively engaged to catheter wire 16 and slidably disposed within second chamber 52 of guide head 26 . when the catheter wire 16 is manipulated , the second wedge member 34 is movable in a forward and backward movement inside second chamber 52 and engageable with the inner edge of each guide fin 30 . since the second wedge member 34 has a slightly greater diameter than the inner edge of each guide fin 30 this structural arrangement permits the second wedge member 34 to push the guide fins 30 outwardly through slot 86 as the second wedge member 34 advances along the inner edge of each guide fin 30 . the incremental advancement of the second wedge member 34 in relation to the guide body 94 effectively changes the degree to which each guide fin 30 emerges above the surface of the guide head 26 from the second chamber 52 . similar to the operation of the cutter head 24 , the guide fins 30 collectively act as a spring so that once the force from the second wedge member 34 is removed by manipulation of the catheter wire 16 , the guide fins 30 return to their originally retracted position inside second chamber 52 ( fig4 a ). as such , manipulation of the catheter wire 16 controls the effective diameter of the guide fins 30 as well as function to maintain the bifurcated assembly 12 in a centralized position inside the lumen of the vein during operation of the valvulotome device 10 . because the first and second wedge members 32 and 34 are centrally disposed within the first and second chambers 50 , 52 , respectively , the cutting blades 28 and guide fins 30 emerge equidistantly therefrom to ensure the centralized passage through the lumen of the vein of the bifurcated assembly 12 as well as uniform cutting of the venous valves by the cutter body 24 , while avoiding damage to the venous luminal walls . as such , the simultaneous adjustability of the cutting blades 28 and guide fins 30 permits the user to adjust the valvulotome device 10 “ on - the - fly ” when a vein of varying inner diameter is presented during the cutting procedure . preferably , the effective diameter of the cutting blades 28 in the fully retracted position is 2 . 0 mm , while in the fully expanded position the effective cutting diameter is 4 . 0 mm . this calibration system provides the user of the valvulotome device 10 with the capability to adjust the effective cutting diameter of the cutting blades 28 to a midrange value of 3 . 0 mm by manipulation of the catheter wire 16 . accordingly , the valvulotome device 10 provides the ability to adjust the effective cutting diameter of the cutter head 24 to 2 . 0 mm , 3 . 0 mm and 4 . 0 mm by the user . fig7 illustrates the means for enabling the user to control the effective cutting diameter of the cutter head 24 . as noted above , manipulation of the catheter wire 16 directly affects simultaneous movement of the first and second wedge members 32 , 34 , which in turn respectively engage the cutting blades 28 and guide fins 30 . because of this direct relational movement between these various structural components , the valvulotome device 10 can be directly calibrated such that a desired incremental distance of remote movement of the first and second wedge members 32 , 34 within the bifurcated assembly 12 can be accurately achieved by the user by effecting the identical , incremental distance movement of the catheter wire 16 at handle 14 . in addition , the bifurcated assembly 12 is free to swivel about its axis within the lumen of the vein , as seen in fig6 . the catheter 17 has attached to its distal end a swivel component 23 . the swivel component 23 consists of a profile change of the catheter 17 to create a flange . the swivel component 23 , which is permanently fixed the distal end of the catheter 17 , is housed inside the guide head 22 . the swivel component 23 remains fixed while the bifurcated assembly 12 can rotate about its axis . the bifurcated assembly 12 is fixed from motion in the longitudinal direction . the catheter wire 16 is free to pass through the swivel component 23 unobstructed and does not rotate . referring to fig7 - 11 , the handle 14 is adapted for use by a single hand of the user for manipulating the catheter wire 16 and adjusting the cutting blades 28 and guide fins 30 . the handle 14 comprises a handle body 36 having right housing 56 and left housing 58 that encases a retainer rack 44 and defines an opening 74 having a dial 46 rotatably disposed therethrough . as shown , the dial 46 defines a gripping surface 64 along the periphery thereof adapted for movement by a user &# 39 ; s thumb and a pinion 78 adapted for operative engagement to the retainer rack 44 for manipulation of the catheter wire 16 . in addition , the dial 46 includes a plurality of visual indicia , such as indicator dots , for providing the user a visual verification of the diameter setting related to the effective cutting diameter of the cutting blades 28 . retainer rack 44 includes a first rack 60 and second rack 62 which are operatively engaged to the proximal end 76 of catheter wire 16 . as further shown , catheter 17 is engaged through a relief strain 48 for defining the front portion of handle 14 . to ensure that the cutting blades 28 remain at the desired effective cutting diameter , the handle 14 further includes a locking mechanism 38 having locking notches 102 . legs 104 of the first and second racks 60 , 62 are adapted to engage corresponding locking notches 102 to lock the catheter wire 16 in a locked position . referring to fig1 , the handle 14 is shown in the closed position for locking the catheter wire 16 in place . in the closed position , the pinion 78 is engaged to one portion of retainer rack 44 ( fig1 a ). in the closed position shown in fig1 , the pinion 78 is engaged to another portion of retainer rack 44 ( fig1 a ). it should be understood from the foregoing that , while particular embodiments of the invention have been illustrated and described , various modifications can be made thereto without departing from the spirit and scope of the invention as will be apparent to those skilled in the art . such changes and modifications are within the scope and teaching of this invention as defined in the claims appended hereto .