WO1999038549A1

WO1999038549A1 - Tubing system to maintain fluid pressure during surgery

Info

Publication number: WO1999038549A1
Application number: PCT/US1999/002058
Authority: WO
Inventors: David Bastable
Original assignee: Mentor Corporation
Priority date: 1998-01-28
Filing date: 1999-01-27
Publication date: 1999-08-05

Abstract

Fluid flow in a body chamber such as the eye (42) during surgery may be managed using an aspiration tube (22) and an irrigation tube (20), one being disposed within the other. A method and apparatus for supplying fluid to and withdrawing fluid from the chamber (42) during surgery includes a first tube (22), and a second tube (20) disposed around the first tube (22) and forming a space around the first tube (22). A check valve (14) at the proximal end of the second tube (20) may be used to avoid flow of fluid out of the chamber (42). A system for performing surgery may include a surgical instrument connected to the first and second tube (22, 20) arrangement.

Description

TUBING SYSTEM TO MAINTAIN FLUID PRESSURE DURING SURGERY Background of the Invention This invention relates to maintaining fluid 5 pressure in a body chamber such as the eye during surgery.

The anterior region of the eye is a small, fluid- filled chamber. During eye surgery, fluid balance in the eye is maintained by supplying irrigation fluid to the 0 eye and aspirating fluid from the eye using a surgical instrument. One such instrument, particularly useful in removing cataracts, is a phaco-emulsification instrument. A phaco-emulsification instrument includes an ultrasonically vibrated hypodermic needle inserted into s an incision in the eye to break up the cataract lens. The lens fragments and aspirated fluid are removed by suction through the needle.

The surgical instrument is connected to a source of irrigation fluid and a drainage container by a tube o set that includes a series of individual, interconnected irrigation and aspiration tubes. Typically, the tubes run along parallel lines and are connected along at least a portion of their lengths.

To avoid damaging the eye during surgery, the rate 5 at which irrigating fluid is supplied to the eye and aspirated is controlled to ensure that the intraocular pressure remains within acceptable limits. The rate of fluid flow in a tube set for irrigating and aspirating fluid may be controlled, e.g., by a peristaltic pump that 0 induces a vacuum in the aspiration tube. One example of such a tube set that includes an integral reservoir used to measure pressure within the eye is described in U.S.S.N. 08/472,884, entitled "Controlling Pressure in the Eye During Surgery, " which is incorporated herein by 5 reference. During phaco-emulsification surgery, lens particles from the eye may collect in the tip of the needle and occlude the aspiration flow out of the eye. Such an occlusion causes the fluid pressure in the aspiration tube to drop as fluid continues to be withdrawn from the tube by the induced vacuum.

When the occlusion breaks, aspiration fluid rapidly surges out of the eye into the aspiration tube due to the induced vacuum. If uncontrolled, the fluid surge may damage the eye. Devices currently employed to avoid surging either restrict the uncontrolled flow of fluid out of the eye or use electronic sensors and valves to react to the surge after the occlusion has broken.

Summary of the Invention This invention features managing fluid flow in the eye during surgery using an aspiration tube and an irrigation tube, one being disposed within the other. This arrangement causes fluid to be injected into the eye at the same rate it is withdrawn when an occlusion at the tip of the surgical instrument is broken, thus maintaining the stability of the fluid pressure in the eye .

In general, in one aspect, the invention features an apparatus for supplying fluid to and withdrawing fluid from a body chamber during surgery, including a first tube for carrying fluid, and a second tube disposed around the first tube and forming a space around the first tube for carrying fluid. In general, in another aspect, the invention features an apparatus for supplying fluid to and withdrawing fluid from a body chamber during surgery, including a first tube for carrying fluid and having a proximal end and a distal end, a second tube for carrying fluid disposed around the first tube, and a check valve at the proximal end of the second tube for avoiding flow of fluid out of the chamber (e.g., backflow through the second tube) . In general, in another aspect, the invention features a system for performing surgery on a body chamber, including a surgical instrument for supplying fluid to and withdrawing fluid from the chamber, and a first tube and a second tube connected to the instrument, the second tube being disposed around the first tube and forming a space around the first tube. In general, in another aspect, the invention features a method for maintaining fluid pressure of a body chamber during surgery, including withdrawing fluid from the chamber by a first tube and supplying fluid to the chamber by a second tube disposed around the first tube.

Preferred embodiments of any of these aspects may include the following features. The first tube may be configured to withdraw the fluid from the chamber and the second tube may be configured to supply the fluid to the chamber. At least one of the first tube or said second tube may be configured to deform in response to a vacuum level. Also, the first and second tubes, which may be coaxial or concentric, may be made from silicone rubber or polyvinylchloride .

The apparatus may include a spacer, which may be in the form of an elongated strip of material, connected between the first tube and the second tube. The first and second tubes and the spacer may be formed as an integral unit from a unitary piece of material, which may be autoclavable .

The proximal end of the tubes may be connectable to a fluid source and a pump, and the distal ends may be connectable to a surgical instrument . The surgical instrument of the system may be a phaco-emulsification instrument .

An advantage of this invention is the use of tubes to balance fluid flow into and out of the eye during surgery, rather than relying on electronic or other external devices. The check valve may help to avoid flow of fluid out of the eye when an occlusion breaks. The use of spacers also helps in the priming of the surgical system prior to use.

Another advantage of this invention is the formation of the tube arrangement as an integral unit, which may be autoclavable.

A further advantage of this arrangement is avoiding an extended evacuated aspiration tube that may quickly fill with fluid from the eye when the occlusion breaks .

Other features and advantages of the invention will become apparent from the following detailed description, and from the claims.

Brief Description of the Drawings Fig. 1 schematically shows an eye surgery system. Fig. 2 illustrates a lengthwise view of an arrangement of concentric aspiration and irrigation tubes and the flow of fluid therein.

Fig. 3 shows a cross section of the tubes of Fig. 2.

Fig. 4 illustrates the deformation of the aspiration tube in the arrangement of Fig. 2 during an occlusion.

Fig. 5 shows a cross section of the tubes of Fig. 2 formed as an integral unit .

Description of the Preferred Embodiments Fig. 1 shows a system 10 for supplying fluid to and withdrawing fluid from the eye during surgery. Fluid is supplied to the eye by irrigation tube 20 and is withdrawn from the eye by aspiration tube 22. The proximal end of irrigation tube 20 is connected to an IV bottle 12 which supplies fresh fluid. The proximal end of aspiration tube 22 is disposed within a waste disposal container 18. The distal ends of irrigation and aspiration tubes 20 and 22 are inserted into a handpiece 30, including a hydraulic nozzle 32, of a surgical instrument such as a phaco-emulsification unit for manipulation in eye 42.

The fluid pressure at the proximal end of the irrigation tube 20 is determined by the height of the IV 5 bottle 12 above the patient's eye (typically 60 cm) .

Fluid flows into irrigation tube 20 when a pinch valve 16 is opened by the user, as discussed below.

As described in U.S.S.N. 08/472,884, referred to above, a peristaltic pump 50 induces a vacuum in o aspiration tube 22 by alternately contracting and releasing a section 22a of tube set 22. The induced vacuum draws aspirated fluid from eye 42 into aspiration tube 22.

As shown in Figs. 1, 2 and 3, aspiration tube 22 s is disposed within irrigation tube 20 along a section 40 between an endpiece 52 and a fitting 54 on handpiece 30. Section 40 is preferably 6 to 10 feet long, or approximately half the length of the fluid path from source 12 to the eye 42. Tubes 20 and 22 are coaxial, o and preferably concentric, in section 40. Endpiece 52 preferably has connectors such as luers (not shown) for attaching irrigation tube 20 and aspiration tube 22 between section 40, and fluid source 12 and disposal container 18, respectively. 5 Irrigation and aspiration tubes 20 and 22 may be made, e.g., from silicone rubber, polyvinylchloride (PVC) or a similar pliable, biocompatible material. In particular, the material should be sufficiently pliable to allow for both compression and expansion of aspiration 0 tube 22, and return to its original shape after deformation.

In Figs. 2 and 3, arrows 34 and 36 show the flow of fluid in aspiration tube 22 and irrigation tube 20 in section 40. In Fig. 3, arrow 34 shows fluid flow into 5 the page, and arrows 36 show fluid flow out of the page. A check valve 14 is disposed in irrigation tube 20 at endpiece 52 to avoid flow of irrigation fluid out of the eye .

In section 40, irrigation tube 20 is sized to allow adequate fluid flow around aspiration tube 22. For 5 example, the inner diameter 26 and outer diameter 28 of aspiration tube 22 may be .065 in. and .105 in., respectively, thereby defining an aspiration tube wall thickness of .020 in. The coaxial irrigation tube may have an outer diameter of .250 in. and a thickness of ιo .032 in. This provides an annular chamber having a width 29 of .081 in.

The spacing between tubes 20, 22 in section 40 is maintained by spacers 24 located along the length of tubes 20 and 22. The spacers preferably form four is chambers in the space between the irrigation and aspiration tubes. Spacers 24 may be thin pieces of material connected to the outer surface of aspiration tube 22 and the inner surface of irrigation tube 20. In the example described above, the spacers may have a width

2o of .010 in. Spacers 24 allow fluid to flow around aspiration tube 22 in irrigation tube 20 within section 40. In particular, spacers 24 prevent the inner tube from coiling within the outer tube, which would block the flow of fluid in the tubes. The use of spacers 24 also

25 aids in the evacuation of air from the system during priming, as discussed below.

The irrigation tube 20, aspiration tube 22 and spacers 24 are preferably manufactured as a single, integral unit from a unitary piece of material, e.g., by

30 extrusion molding (Fig. 5) . Such an integral unit may be disposable or reusable if made from an autoclavable material .

In operation, prior to the surgical procedure, the user connects the irrigation and aspiration tubes 20 and

35 22, which are sterilized. The proximal end of irrigation tube 20 is connected to IV bottle 12. The proximal end of aspiration tube 22 is disposed within disposal container 18, and tube portion 22a is placed in pump 50. Irrigation tube 20 and aspiration tube 22 are then attached to endpiece 52 of section 40. The distal ends of tubes 20 and 22 at the distal end of section 40 are connected to handpiece 30 of the surgical instrument by fitting 54. Handpiece 30 is constructed to receive irrigation fluid from tube 20 and expel irrigation fluid into tube 22 through fitting 54. The irrigation and aspiration lines may be coaxial within handpiece 30, but other types of handpieces may be used with the combination of irrigation tube 20 and aspiration tube 22.

When the surgical procedure is started, system 10 is primed by opening pinch valve 16 and completely filling tubes 20 and 22 with irrigation fluid from IV bottle 12. Fluid may be pumped directly into aspiration tube 22 before it is connected to handpiece 30, or a test chamber placed over nozzle 32 allows fluid to flow from the irrigation tube 20 into aspiration tube 22. For example, priming is accomplished by repeatedly applying a relatively strong vacuum to aspiration tube 22 several times using pump 50 and allowing fluid to flow into irrigation tube 20. Priming eliminates air or other gases from the tubes. Spacers 24 provide increased surface area for the fluid that pushes against the air in the tubes during priming.

During the surgical procedure, fresh irrigating fluid flows into the eye from IV bottle 12 through irrigation tube 20. Pump 50 continuously operates on tube portion 22a to aspirate fluid from the eye into drainage .

The purpose of the arrangement in which the aspiration tube 22 is disposed inside the irrigation tube 20 is to reduce the surge of fluid out of the eye caused by the aspiration tube 22 returning to its original shape after having been collapsed due to a temporary occlusion at the tip of the surgical instrument.

As shown in Fig. 4, aspiration tube 22 collapses due to the induced vacuum in the tube when there is an occlusion at the tip of the surgical instrument. Aspiration tube 22 deforms due to the pliable characteristics of the material from which it is made. As shown by arrows 36, fluid from IV bottle 12 fills the extra space created between the irrigation tube 20 and the collapsed aspiration tube 22. After the occlusion breaks free, aspiration tube 22 returns to its original shape. In returning to its original shape, the expanding inner diameter of aspiration tube 22 acts as a pump to draw fluid out of the eye, while the expanding outer diameter pumps irrigation fluid from the space between the tubes into the eye. When the displaced fluid flows through the space between the tubes, check valve 14 at endpiece 52 limits the flow of fluid out of the eye 42. Thus, after an occlusion breaks, fluid is pulled out of the eye by the expanding aspiration tube 22 in section 40, and fluid flows into the eye from irrigation tube 20. The singular action of the expanding aspiration tube 22 in section 40 causes fluid flow in both directions at the same time and in the same proportions. This fluid flow avoids damage to the eye during the surge that results from an occlusion that has broken free, without requiring additional equipment to maintain the proper fluid flow.

Other embodiments are within the scope of the following claims. For example, the irrigation tube 20 may be located within the aspiration tube 22. The spacers 24 may be located periodically along the length of section 40. The irrigation tube 20, aspiration tube 22 and spacers 24 may be manufactured as separate pieces that are connected together, with the spacers molded to either of the tubes by extrusion. The arrangement of a pliable aspiration tube within the irrigation tube may also be used to control chamber stability of any body chamber undergoing a surgical procedure requiring irrigation and aspiration, such as for liposuction in which canulas are used to pump fluid into and out of the body.

What is claimed is:

Claims

1. Apparatus for supplying fluid to and withdrawing fluid from a body chamber during surgery, comprising a first tube for carrying fluid; and a second tube disposed around said first tube and forming a space around said first tube for carrying fluid.

2. The apparatus of claim 1 wherein said first tube is configured to withdraw said fluid from the chamber and said second tube is configured to supply said fluid to said chamber.

3. The apparatus of claim 1 wherein at least one of said first tube or said second tube is configured to deform in response to a vacuum level .

4. The apparatus of claim 1 wherein said first tube and said second tube are coaxial .

5. The apparatus of claim 1 wherein said first tube and said second tube are concentric .

6. The apparatus of claim 1 further comprising a spacer connected between said first tube and said second tube .

7. The apparatus of claim 6 wherein said spacer is an elongated strip of material.

8. The apparatus of claim 6 wherein said first tube, said second tube and said spacer are formed as an integral unit from a unitary piece of material .

9. The apparatus of claim 8 wherein said integral unit is autoclavable.

10. The apparatus of claim 1 wherein said tubes comprise silicone rubber.

11. The apparatus of claim 1 wherein said tubes comprise polyvinylchloride.

12. A system for performing surgery in a body chamber, comprising a surgical instrument for supplying fluid to and withdrawing fluid from the chamber; and a first tube and a second tube connected to said instrument, said second tube being disposed around said first tube and forming a space around said first tube.

13. The system of claim 12 wherein said first tube is configured to withdraw said fluid from the chamber and said second tube is configured to supply said fluid to said chamber.

14. The system of claim 12 wherein at least one of said first tube or said second tube is configured to deform in response to a vacuum level .

15. The system of claim 12 wherein said instrument is a phaco-emulsification instrument.

16. Apparatus for supplying fluid to and withdrawing fluid from a body chamber during surgery, comprising a first tube for carrying fluid having a proximal end and a distal end; a second tube for carrying fluid disposed around said first tube; and a check valve at the proximal end of said second tube for avoiding flow of fluid out of the chamber.

17. The apparatus of claim 16 wherein said proximal end is connectable to a fluid source.

18. The apparatus of claim 17 wherein said proximal end is further connectable to a pump.

19. The apparatus of claim 16 wherein said distal end is connectable to a surgical instrument.

20. A method for maintaining fluid pressure of a body chamber during surgery, comprising withdrawing fluid from the chamber by a first tube ; and supplying fluid to the chamber by a second tube disposed around said first tube.

21. The method of claim 20 wherein said withdrawing includes applying a vacuum to said first tube .

22. The method of claim 20 wherein fluid is supplied to the chamber through a space formed between said second tube and said first tube during said supplying step.

23. The method of claim 20 further comprising avoiding flow of fluid out of the chamber.