Handle for a Rotational Atherectomy Device

Description

The present invention relates to a handle for a rotational atherectomy device which is a device for removing material, such as stenotic lesions, from the interior of a blood vessel such as a human artery by rotating a drive shaft with an abrasive element thereon within the vessel to partially or completely ablate the unwanted material.

Atherosclerosis, the clogging of arteries, is a leading cause of coronary heart disease. Blood flow through the peripheral arteries (e.g., carotid, femoral, renal etc.), is similarly affected by the development of atherosclerotic blockages. A conventional method of removing or reducing blockages in blood vessels is known as rotational atherectomy. A long guidewire is advanced into the diseased blood vessel and across the stenotic lesion. A hollow drive shaft formed from a torque transmitting coiled wire(s) is advanced over the guidewire. The distal end of the drive shaft terminates in a burr provided with an abrasive surface formed from diamond grit or diamond particles. The burr is positioned against the occlusion and the drive shaft rotated at extremely high speeds (e.g., 20,000-160,000 rpm).

As the burr rotates, the physician slowly advances it so that the abrasive surface of the burr scrapes against the occluding tissue and disintegrates it ^~ feducing the occlusion and improving the blood flow through the vessel. Such a method and a device for performing the method are described in, for example, U.S. Patent No. 4,990,134 to Auth. It is also known from U.S. Patent No. 6,132,444 to Shturman (the instant inventor) et al., to provide a drive shaft which is also formed from a single layer of torque transmitting coiled wire or wires but different to the device described in US Patent No. 4,990,134 to Auth, mentioned above, by having an eccentric enlarged diameter section located proximally to and spaced away from the distal end of the drive shaft formed from a single layer of torque transmitting coiled wire(s). According to US Patent 6,132,444 to Shturman, abrasive particles are located around a maximum diameter of the eccentric segment of the drive shaft

thereby forming an eccentric abrasive element positioned proximally to and spaced away from the distal end of the drive shaft formed from said single layer of torque transmitting coiled wire(s).

A rotational atherectomy device with distal embolic protection capability is known from WO 2006/126076 to Shturman (the current inventor). In the preferred embodiment of the Shturman application the distal end of the fluid impermeable drive shaft is advanced across the stenotic lesion to be treated and flushing fluid is pumped through the drive shaft in an antegrade direction to enter the vessel through at least one luminal opening located distally to the abrasive element As a result of a continued flow of flushing fluid into the vessel in this way, a fluid pressure is generated in the vessel distal to the abrasive element which is sufficient to generate a retrograde flow of at least a portion of the flushing fluid around the abrasive element and the fluid impermeable drive shaft. This retrograde flowing flushing fluid entrains stenotic debris abraded by the rotating abrasive element and flows into a lumen of stationary drive shaft thereby preventing migration of debris along the treated vessel. In the most preferred embodiment, abraded debris are not only being removed from the treated vessel but from the patient altogether.

It is known from WO 2006/126076, to provide a handle for a rotational atherectomy device that couples a rotatable drive shaft to a detachable non-rotatable (and therefore in WO 2006/126076 referred to as 'stationary') flushing fluid supply tube, the proximal end of the drive shaft being received within, and attached to, the distal end of a prime mover shaft rotatably mounted on bearings within the housing. The detachable 'stationary' flushing fluid supply tube extends into the proximal end of the rotatably mounted prime mover shaft and is coaxial with the longitudinal axis of the drive shaft and the prime mover shaft Flushing fluid is supphed from the distal end of the detachable 'stationary' flushing fluid supply tube into the rotating prime mover shaft and flows from the prime mover shaft into the lumen m the drive shaft. A releasable coupling is provided, the detachable 'stationary' flushing fluid supply tube being carried by a detachable coupling member which engages with the handle that forms the cooperating part of the coupling and in which is

received the prime mover and drive shaft. The coupling enables the flushing fluid supply tube to be attached to, and detached from, the handle as and when necessary.

It will be appreciated that, due to the very high rotational speeds of the drive shaft, it is essential that the flushing fluid supply tube and the prime mover shaft in which it is received remain coaxial with each other so that there is no contact between the rotating prime mover shaft and the stationary flushing fluid supply tube received therein. In practice, this is very difficult to achieve with a coupling such as described in the Applicant's previous application as it requires the components of the handle to be made to very tight tolerances.

The present invention seeks to overcome or substantially alleviate the problem described above.

According to the present invention, there is provided a handle for providing flow of pressurised fluid from a detachable fluid supply tube into a lumen of a flexible drive shaft carrying an abrasive element mounted to the drive shaft proximal to and spaced away from its distal end, the handle comprising an elongate prime mover housing and a hollow prime mover shaft rotatably mounted within the prime mover housing, a proximal end portion of the flexible drive shaft being connected to a distal end portion of the hollow prime mover shaft for rotation together with the prime mover shaft, the handle also comprising a coupling member which supports a stationary fluid supply tube coaxial with and permanently received within a proximal end portion of the hollow prime mover shaft, the prime mover shaft being rotatable around the stationary fluid supply tube, the detachable fluid supply tube being releasably connectable to the handle for providing flow of pressurised fluid from the detachable fluid supply tube into the lumen of the flexible drive shaft via the stationary fluid supply tube and the hollow prime mover shaft.

In a preferred embodiment, the stationary fluid supply tube has a plurality of openings proximal to its distal end such that a portion of pressurized fluid flows through these openings to form a fluid bearing between the stationary fluid supply tube and the hollow prime mover shaft.

In a preferred embodiment, the stationary fluid supply tube is received within a lumen formed in the coupling member and is bonded to the coupling member.

The stationary fluid supply tube may be integrally formed with the coupling member.

In one embodiment, the coupling member is received within a proximal end of the prime mover housing and is bonded thereto.

In another embodiment, the coupling member at least partially extends over a proximal end of the prime mover housing and is bonded thereto.

The coupling member may be integral with the prime mover housing.

The stationary fluid supply tube may extend through the housing coupling member.

In one preferred embodiment, the prime mover housing coupling member includes a connecting element for releasably connecting the detachable fluid supply tube thereto.

The connecting element may comprise a female cooperating part and a male cooperating part, one of each being associated with the coupling member and the other being associated with the detachable fluid supply tube.

In a preferred embodiment, the stationary fluid supply tube has radially outward directed openings therein near its distal end for the flow of fluid therethrough, said fluid flow through the radially outward directed openings forming a fluid bearing between the distal end portion of the stationary fluid supply tube and the rotatable prime mover shaft.

Preferably, there is a drain hole in the housing for the egress of flushing fluid out of the housing that has flowed in a retrograde direction along the shaft between the stationary fluid supply tube and the prime mover shaft.

In one embodiment, the stationary fluid supply tube extends through the housing coupling member and the connecting element.

According to another aspect of the invention, there is provided a rotational atherectomy device incorporating the handle according to the invention.

According to another aspect of the invention, there is provided a method of assembling a handle of a rotational atherectomy device to fluidly communicate the distal end of detachable fluid supply tube with a proximal end portion of a flexible fluid impermeable drive shaft carrying an abrasive element rotatable together with said flexible drive shaft, the handle comprising an elongate prime mover housing within which is rotatably mounted a prime mover shaft having a longitudinal axis and proximal and distal end portions, the proximal end portion of the flexible fluid impermeable drive shaft being connected to the prime mover shaft for rotation together with said prime mover shaft, the handle also comprising a prime mover housing coupling member which has inner and outer ends and which supports a stationary fluid supply tube, the method comprising the steps of:

(a) placing an elongate, cylindrical, positioning mandrel within the prime mover shaft, the positioning mandrel having a first large diameter section which locates the positioning mandrel coaxially within the prime mover shaft and a second smaller diameter section coaxial with the first larger diameter section, the second smaller diameter section extending proximally out of the prime mover shaft,

(b) sliding the stationary fluid supply tube, which is mounted to or integral with a coupling member, over the second smaller diameter section of the positioning mandrel so as to position the stationary fluid supply tube within the prime mover shaft so that the positioning mandrel locates the prime mover shaft and the stationary fluid supply tube with their longitudinal axes coaxial to each other, and

(c) bonding the coupling member to the housing so that the prime mover shaft and the connecting tube are fixed coaxially relative to each other and,

(d) removing the positioning mandrel from the prime mover shaft and the stationary fluid supply tube.

In one embodiment, the positioning mandrel is inflatable and the method includes the steps of inflating the mandrel once it has been positioned within both the prime mover shaft and the stationary fluid supply tube and, deflating the inflatable positioning mandrel after the coupling member has been bonded to the prime mover housing so that the position of the prime mover shaft and the stationary fluid supply tube are permanently coaxially positioned relative to each other.

The step of bonding the coupling member to the handle may include the step of applying bonding material to the prime mover housing and/or the coupling member and curing said bonding material using curing time shortening means. The curing time shortening means may conveniently comprise ultraviolet light and/or heat and the like.

In an alternative embodiment, the step of bonding the coupling member to the handle includes the step of welding them together.

In another embodiment, the step of welding the coupling member to the handle includes the step of ultrasonically welding them together.

In another embodiment, the step of welding the coupling member to the handle includes the step of laser welding them together.

Embodiments of the present invention will now be described, by way of example only, with reference to Figures 9 to 22 of the accompanying drawings, Figures 1 to 8 representing the handle for an atherectomy device of the prior art known from WO 2006/126076.

FIGURE 1 is a side sectional view of a prior art rotational atherectomy device, the device shown advanced into a vessel to be treated. Figure 1 illustrates that the device has been advanced across a stenotic lesion to a position in which the distal

counterweight is located distal to the stenotic lesion and the proximal counterweight is intentionally located proximal to the stenotic lesion to be treated. The device has been advanced across the stenotic lesion over a guidewire. Figure 1 illustrates that the guidewire has been partially withdrawn from the device;

FIGURE 2 shows the same view as Figure 1, but after the guidewire has been completely removed from the device;

FIGURE 3 shows the same view as Figures 1 and 2, but after a detachable stationary fluid supply tube has been inserted into a hollow prime mover shaft of a turbine prime mover;

FIGURE 4 shows the same view as Figure 3, but after a flow of pressurized fluid has been initiated in an antegrade direction along a lumen of the drive shaft. The pressuri2ed fluid flowing along the lumen of the drive shaft is entering the vessel only through an opening at a distal end of the drive shaft. The pressurized fluid is shown to flow along the treated vessel in a retrograde direction around the abrasive element and across the stenotic lesion to be treated;

FIGURE 5 illustrates a prior art embodiment of a handle of the rotational atherectomy device. In this prior art embodiment, the detachable stationary fluid supply tube is carried by a detachable coupling member which is configured for coaxial placement of the stationary fluid supply tube within the hollow prime mover shaft;

FIGURE 6 illustrates the same view as Figure 5 but after the detachable coupling member has been releasably attached to the prime mover housing and the detachable stationary fluid supply tube has been inserted into a proximal end portion of the hollow prime mover shaft;

FIGURE 7 illustrates the same view as Figure 6 but after the locking ring has been moved from its proximal to its distal position thereby locking the detachable coupling member to the prime mover housing. Figure 7 also shows that the flow of

the pressurized fluid from the stationary fluid supply tube into the hollow prime mover shaft has been initiated;

FIGURE 8 illustrates the same view as Figure 7 but after the flow of compressed gas to the turbine wheel of the prime mover has been initiated;

FIGURE 9 is a longitudinal cross-sectional view of a proximal end portion of a first embodiment of a handle of the present invention in which an outer surface of the coupling member is bonded to an inner surface of the prime mover housing. The first and other embodiments of the present invention differ from the prior art embodiment of the handle shown in Figures 5 to 8 in that they comprise a stationary fluid supply tube which is permanently received within a proximal end portion of the hollow prime mover shaft. This stationary fluid supply tube is carried by a coupling member which is permanently attached to the prime mover housing, thereby making the stationary fluid supply tube a permanent component of the handle;

FIGURE 10 illustrates a second embodiment of the handle of the invention, in which the handle is similar to the handle shown in Figure 9, but in which an inner surface of the coupling member is bonded to an outer surface of the prime mover housing;

FIGURE 11 illustrates a third embodiment of the handle of the invention in which the handle is similar to the handle shown in Figure 10, but in which the stationary fluid supply tube is integral with the coupling member;

FIGURE 12 illustrates a fourth embodiment of the handle of the invention in which the handle is similar to the handle shown in Figure 11, but in which the coupling member is integral with the prime mover housing and the stationary fluid supply tube extends through the integral coupling member;

FIGURE 13 is similar to Figure 12 except that it shows a distal end of a detachable fluid supply tube;

FIGURE 14 illustrates the same view as Figure 13 but after connection of the detachable fluid supply tube to the stationary fluid supply tube and to the handle;

FIGURE 15 illustrates the same view as Figure 14, but after a flow of pressurized fluid from the detachable fluid supply tube into the stationary fluid supply tube has been initiated. A wall of the stationary fluid supply tube comprises multiple openings located proximal to its distal end. A portion of the pressurized fluid flows radially outward through these openings to form a fluid bearing between the stationary fluid supply tube and the rotatable prime mover shaft;

FIGURE 16 shows an exemplary embodiment of the rotational atherectomy device comprising the handle of the invention. Figure 16 shows that in this exemplary embodiment of the rotational atherectomy device, the solid counterweights have been replaced by fluid inflatable counterweights. The device of Figure 16 also differs from the prior art device in that it does not require a guidewire for advancement towards and across a stenotic lesion to be treated;

FIGURE 17 illustrates how the prime mover housing of Figure 10 may be assembled using a mandrel that facilitates coaxial positioning of the stationary fluid supply tube within the hollow prime mover shaft;

FIGURE 18 is similar to FIGURE 17 except that it shows the stationary fluid supply tube positioned around the mandrel;

FIGURE 19 is the same view as Figure 18, but after a bonding material has been applied to the outer surface of the prime mover housing;

FIGURE 20 is the same view as Figure 19, but after the coupling member has been advanced over the prime mover housing and bonded thereto using the bonding material placed on the outer surface of the prime mover housing. It also shows that the bonding material is exposed to external curing means to fix the relative

positions of the coupling member and the prime mover housing prior to removal of the mandrel;

FIGURE 21 is the same view as Figure 20 but showing the mandrel partially withdrawn after the bonding material has cured and the position of the coupling member and the prime mover housing has been fixed; and

FIGURE 22 shows how an inflatable positioning mandrel may be used instead of a solid one. The inflatable mandrel should be deflated after the bonding material has cured to allow removal of the mandrel from the prime mover housing and coupling member.

Reference is made to "distal" and "proximal" ends and to flow of fluid in an "antegrade" and "retrograde" direction. For the avoidance of doubt, and for the purpose of this specification, the distal end is considered to refer to the end of the device which is inserted into the vessel in the body of the patient and the proximal end is the end of the device which remains outside the body of the patient and is connected to a handle assembly for both rotating and longitudinally moving the drive shaft within the treated vessel. Antegrade flow refers to a direction of flow from the proximal towards the distal end of the device. Similarly, retrograde flow refers to a direction of flow in the opposite direction, i.e. from the distal to the proximal end of the device. In Figures 1 to 22, flow of fluid through the atherectomy device in an antegrade direction is indicated by arrows 'AF' or 'FF', and the flow of fluid around the device in a retrograde direction is indicated by arrows marked 'RF'.

Figures 1 to 4 illustrate in longitudinal cross-sections a prior art rotational atherectomy device with distal protection capability. This rotational atherectomy device is comprised of an abrasive element 1 which is mounted to a flexible drive shaft 2 between and spaced away from two solid counterweights. One of these two counterweights is located at the distal end of the drive shaft 2 and is referred to as a distal counterweight 3. The other counterweight is referred to as a proximal counterweight 4. The abrasive element 1 and the counterweights 3, 4 are rotatable

together with the drive shaft 2. In the embodiment of Figures 1 to 4 a distal end of the rotational atherectomy device coincides with the distal end of the flexible drive shaft 2. The drive shaft 2 comprises a torque transmitting coil 7 and a long lumen 8 for the transport of pressurized fluid to the distal end of the device. A fluid impermeable membrane 9 lines the torque transmitting coil 7 and forms a fluid impermeable wall of the long lumen 8 of the drive shaft 2. The long lumen 8 also serves as a guidewire lumen for advancing the device across the stenotic lesion 60 over the guidewire 66.

A proximal end portion of the flexible drive shaft 2 is connected to a distal end portion of a hollow prime mover shaft 10 for rotation by a gas powered turbine prime mover. The turbine prime mover is comprised of a turbine wheel 11 mounted to the hollow prime mover shaft 10. The hollow prime mover shaft 10 is mounted within an elongate prime mover housing 20 by a pair of bearings 31, 32. The elongate prime mover housing 20 is slidably received within a drive shaft sheaf housing 40. A stationary drive shaft sheaf 44 extends in a distal direction from the sheaf housing 40 around the flexible drive shaft 2. This stationary sheaf 44 forms an outer wall of a long annular drainage lumen 50 around the rotatable drive shaft 2. The elongate prime mover housing 20 comprises a proximal end portion of a handle of the rotational atherectomy device and the drive shaft sheaf housing 40 comprises a distal end portion of a handle of the rotational atherectomy device.

Figure 1 shows the prior art rotational atherectomy device advanced across a stenotic lesion 60 to be treated. Figure 1 illustrates that the device has been advanced to a position in which the distal counterweight is located distal to the stenotic lesion and the proximal counterweight is intentionally located proximal to the stenotic lesion to be treated. The device has been advanced across the stenotic lesion over a guidewire 66 which has to be withdrawn from a distal end portion of the drive shaft 2 prior to initiating rotation of the drive shaft. Rotation of the drive shaft with counterweights around a distal end portion of the guidewire has been found to cause fatigue fracture along the distal end portion of the guide wire. Figure 1 shows that a distal end portion of the guidewire has been withdrawn from a distal end portion of the drive shaft.

Figure 2 shows the same view as Figure 1, but after the guidewire 66 has been completely removed from the device. The guidwire 66 should be completely removed from the device to allow insertion of the detachable stationary (i.e. non- rotatable) fluid supply tube into the hollow rotatable prime mover shaft 10 of the turbine prime mover.

Figure 3 shows the same view as Figure 2, but after a detachable stationary fluid supply tube 67 has been inserted into a hollow prime mover shaft 10 of a turbine prime mover. In this Figure, the stationary fluid supply tube 67 is shown inserted into the hollow prime mover shaft 10 but without any means to retain it in place coaxial with the prime mover shaft.

Figure 4 shows the same view as Figure 3, but after a flow of pressurized fluid has been initiated in an antegrade direction 'AF' from the stationary fluid supply tube 67 into a hollow prime mover shaft 10 and further into the lumen of the flexible drive shaft 2. The pressurized fluid flowing along the lumen of the drive shaft is entering the vessel only through an opening at a distal end of the drive shaft. A portion of pressurized fluid is shown to flow along the treated vessel in a retrograde direction 'RF' around the abrasive element 1 and across the stenotic lesion 60 to be treated. Figure 4 shows that the retrograde flowing fluid RF is aspirated into the drainage lumen 50 and out of the patient's body. Any embolic particles (not shown) which may be abraded from the stenotic lesion become entrained by the retrograde flowing fluid RF and are removed from the treated vessel and from the patient's body.

Figure 5 illustrates a prior art embodiment of a handle of the rotational atherectomy device. In this prior art embodiment, the detachable stationary fluid supply tube 77 is carried by a detachable coupling member 90 which is configured for co-axial placement of the stationary fluid supply tube 77 within the hollow prime mover shaft 110. The detachable stationary fluid supply tube 77 extends through the coupling member 90. A locking ring 95 is disposed around the coupling member 90

to allow the coupling member to be releasably attached to the prime mover housing 120.

Figure 6 illustrates the same view as Figure 5 but after the detachable coupling member 90 has been releasably attached to the prime mover housing 120 and the detachable stationary fluid supply tube 77 has been inserted into a proximal end portion of the hollow prime mover shaft 110.

Figure 7 illustrates the same view as Figure 6 but after the locking ring 95 has been moved from its proximal to its distal position thereby locking the detachable coupling member 90 to the prime mover housing 120. Figure 7 also shows that the flow of the pressurized fluid from the stationary fluid supply tube 77 into the hollow prime mover shaft 110 has been initiated.

Figure 8 illustrates the same view as Figure 7 but after the flow of compressed gas 'G' to the turbine wheel 11 of the prime mover has been initiated.

Figure 9 is a longitudinal cross-sectional view of a proximal end portion of a first embodiment of a handle of the present invention in which an outer surface of the coupling member is bonded to an inner surface of the prime mover housing. The first and other embodiments of the present invention differ from the prior art embodiment of the handle shown in Figures 5 to 8 in that they comprise a stationary fluid supply tube 177 which is permanently received within a proximal end portion of the hollow prime mover shaft 210. This stationary fluid supply tube 111 is carried by a coupling member 190 which is permanently attached to the prime mover housing 220, making the stationary fluid supply tube a permanent component of the prime mover housing 220 and the whole handle. Figure 9 shows that the stationary fluid supply tube is received within a lumen of the coupling member 190. Figure 9 shows an embodiment in which the stationary fluid supply tube extends only along a wider distal end portion of the lumen 179 of the coupling member 190. The lumen of the coupling member 190 should be coaxial with a lumen of the stationary fluid supply tube 177. Figure 9 shows that the stationary fluid supply tube is bonded to the coupling member along the wider distal end portion of the lumen

179 of the coupling member 190 such that a distal end portion of the stationary- fluid supply tube 177 permanently extends into a proximal end portion of the hollow prime mover shaft 210. A wall of the stationary fluid supply tube 177 comprises multiple openings 185 located proximal to its distal end 186. A portion of the pressurized fluid flows radially outward through these openings 185 to form a fluid bearing between the stationary fluid supply tube 177 and the rotatable prime mover shaft 210. The hollow prime mover shaft 210 is supported by a pair of bearings 31, 32 within the prime mover housing 220. Figure 9 shows that a male portion 188 of a connector extends in a proximal direction from the coupling member 190. In this embodiment, a female portion of the connector should be carried by the detachable fluid supply tube (not shown in this drawing). It should be noted that the arrangement of male/female portions of the connector may be reversed. It should be also noted that any of the portions of the connector may be formed integrally with or attached to the stationary fluid supply tube. It should also be noted that any type of the connector may be used including a rectangular fluid connector. In addition, a lumen perpendicular to a longitudinal axis X-X of the stationary fluid supply tube may be formed in the coupling member, therefore permitting a portion of the connector to be located sidewise with respect to the axis X-X and the lumen 179 of the coupling member 190.

Figure 10 illustrates a second embodiment of the handle of the invention, in which the handle is similar to the handle shown in Figure 9, but in which an inner surface of the coupling member 190' is bonded to an outer surface of the prime mover housing 220.

Figure 11 illustrates a third embodiment of the handle of the invention in which the handle is similar to the handle shown in Figure 10, but in which the stationary fluid supply tube 177' is integral with the coupling member 190".

Figure 12 illustrates a fourth embodiment of the handle of the invention in which the handle is similar to the handle shown in Figure 11, but in which the coupling member 190'" is integral with the prime mover housing 220' and the stationary fluid supply tube 177 extends through the integral coupling member 190".

Figure 13 is similar to Figure 12 except that it shows a distal end of a detachable fluid supply tube 234, the detachable fluid supply tube carrying a female part 233 of the fluid connector and the prime mover housing 220' or the stationary fluid supply tube 177 comprising the male portion 188 of the fluid connector.

Figure 14 illustrates the same view as Figure 13 but after the detachable fluid supply tube 234 has been connected to the stationary fluid supply tube 177.

Figure 15 illustrates the same view as Figure 14, but after a flow of pressurized fluid FF from the detachable fluid supply tube 234 into the stationary fluid supply tube 177 has been initiated. A portion of the pressurized fluid flows radially outward through openings 185 located proximal to the distal end of the stationary fluid supply tube 177, and forms a fluid bearing between the stationary fluid supply tube 111 and the rotatable prime mover shaft 210. Excess fluid is drained from the prime mover housing through a drainage opening 240.

Figure 16 illustrates an exemplary embodiment of the rotational atherectomy device with distal protection capability. The device shown in Figure 16 incorporates the stationary fluid supply tube 177 permanently received within a proximal end portion of the hollow prime mover shaft 210. The stationary fluid supply tube is carried by a coupling member 190'" which is either made integrally with the prime mover housing 220' as shown in Figure 16, or is carried by the coupling members 190, 190' and 190" which are permanently attached to the prime mover housing 220' as shown in Figures 9, 10 and 11 respectively. Figure 16 shows an embodiment in which the stationary fluid supply tube 177 extends through the coupling member 190'". The rotational atherectomy device shown in Figure 16 differs from the prior art device shown in Figures 1 to 4 in that its counterweights 300, 400 are fluid inflatable. Figure 16 shows that the distal fluid inflatable counterweight 300 is formed from a single fluid impermeable membrane 700. The fluid impermeable membrane 700 extends around an anchoring sleeve 800 and a distal portion of the torque transmitting coil 200 of the drive shaft 600. Another fluid impermeable membrane 777 extends around a proximal portion of the torque transmitting coil

200 and forms a fluid impermeable wall of the proximal portion of the long lumen 500 of the drive shaft 600. The long lumen 500 of the drive shaft 600, the torque transmitting coil 200 of the drive shaft 600 and the hollow prime mover shaft 210 have common longitudinal axis X-X. The fluid impermeable membrane 700 crosses the longitudinal axis X-X at the distal end 1000 of the device, thereby preventing pressurized fluid (not shown) flowing along the lumen 500 of the drive shaft 600 from entering the treated vessel in the direction of said longitudinal axis X-X. Therefore, the pressurized fluid has to pass through and inflate the distal fluid inflatable counterweight 300, prior to exiting from the device through outflow openings 333 in the distal fluid inflatable counterweight 300 in a direction different from the direction of the longitudinal axis X-X of the torque transmitting coil 200 and the lumen 500 of the drive shaft 600.

Figure 16 shows that the proximal fluid inflatable counterweight 400 is formed from a separate fluid impermeable membrane 777. It also shows that the anchoring sleeve 800 extends around the torque transmitting coil 200 only along a distal end portion of the drive shaft 600, and that the wall of the long lumen 500 of the drive shaft 600 along its proximal end portion is made fluid impermeable only by the separate fluid impermeable membrane 777.

Figure 16 illustrates that the drive shaft 600 of the device is rotated by a turbine prime mover similar to one shown in Figures 1 to 8 and Figures 9 tol5. This compressed gas powered prime mover is comprised of a turbine wheel 11 mounted to the hollow prime mover shaft 210. The hollow prime mover shaft 210 is mounted within an elongate prime mover housing 220' by a pair of bearings 31, 32. The elongate prime mover housing 220' is slidably received within a drive shaft sheath housing 40. The drive shaft sheath housing 40 comprises a distal end portion of the handle of the device, and the elongate prime mover housing 220' comprises a proximal end portion of the handle of the device.

Figure 17 illustrates how the prime mover housing of Figure 10 may be assembled using a mandrel 2000 that facilitates coaxial positioning of the stationary fluid supply tube 177 within the hollow prime mover shaft 210;

Figure 18 is similar to Figure 17 except that it shows the stationary fluid supply tube 177 positioned around the mandrel 2000;

Figure 19 is the same view as Figure 18, but after a bonding material 2100 has been applied to the outer surface of the prime mover housing 220;

Figure 20 is the same view as Figure 19, but after the coupling member 190' has been advanced over the prime mover housing 220 and bonded thereto using the bonding material 2100 placed on the outer surface of the prime mover housing 220. It also shows that the bonding material 2100 is exposed to external curing means 3000 to fix the relative positions of the coupling member 190' and the prime mover housing 220 prior to removal of the mandrel 2000;

Figure 21 is the same view as Figure 20 but showing the mandrel 2000 partially withdrawn after the bonding material has cured and the position of the coupling member 190' and the prime mover housing 220 has been fixed;

Figure 22 shows how an inflatable positioning mandrel 4000 may be used instead of a solid one. The inflatable mandrel 4000 should be deflated after the bonding material has cured to allow removal of the mandrel 4000 from the prime mover housing 202 and coupling member 190'.