Uterine catheters are often used to perfuse the uterus with fluid. Perfusion may be used in various diagnostic procedures, such as for the detection of uterine pathology, for example, polyps or the like. This may involve the perfusion of a radio-opaque medium for hysterosalpingography (HSG), perfusion of an ultrasound contrast medium for HyCoSe, perfusion of a saline solution for salpingography, or perfusion of a coloured dye for laparoscopy. Perfusion may also be used in various treatment procedures such as: tubal perfusion with prepared sperm, injection of air under pressure to overcome minor obstructions in the fallopian tubes, or the infusion of fluid to dislodge ectopic pregnancies or remove debris (a process called hydrotubation).

Current uterine catheters used to perfuse fluid have some means of sealing the catheter in the region of the cervix. This may take the form of a small cuff inflated within the uterus against the internal os. Alternatively, a small flange or the like on the catheter may be located to engage with the external os and form a seal in this region. The seal provided by these current catheters may not provide a complete seal in some situations. Also, the seal may be compromised if the sealing member is inadvertently moved away from the tissue with which it is to seal. Leakage is a disadvantage because the fluids infused in the uterus are often very expensive (in the case of the contrast media) or are only available in small quantities (in the case of prepared sperm).

It is an object of the present invention to provide an alternative uterine catheter.

According to one aspect of the present invention there is provided a uterine catheter of the above-specified kind, characterised in that the cuff is elongate and longer than the cervical canal so that opposite ends of the cuff protrude from the internal and external os and can be inflated to form a seal with both the internal and external os.

The catheter preferably has an inflation lumen opening into the cuff at two locations towards opposite ends of the cuff. The cuff is preferably of an elastic material, such as silicone rubber. The diameter of the shaft is preferably about 2mm and the length of the cuff is preferably about 70mm. The patient end of the shaft is preferably rounded and closed, the shaft opening through a side opening. The catheter may include a Y-connector at its machine end, the Y-connector having two side arms making connection respectively with an inflation lumen for the cuff and a bore through the shaft. The catheter may include a stopcock connected with a side arm of the Y-connector making connection with the inflation lumen.

A uterine perfusion catheter according to the present invention, will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a partly sectional plan view of the catheter with the cuff deflated; Figure 2 is an enlarged cross-sectional view through the shaft of the catheter along line II-II of Figure 1 ; and Figure 3 is a plan view showing the patient end of the catheter with the cuff inflated.

The catheter has a shaft 1 of a plastics material, such as PVC, with an external diameter of 2mm and a length of about 250mm. The shaft 1 is extruded with a major, large bore lumen 2 and a minor, inflation lumen 3, as shown in Figure 2. The patient end tip 4 of the shaft 1 is rounded and closed, the catheter opening from the major lumen 2 through a side aperture 5 set back from the tip by about 2mm.

A sealing cuff 10 is attached to the shaft 1 at opposite ends 11 and 12, such as by means of an adhesive, the patient end 11 of the cuff being set back from the patient end tip 4 by about 1 Omm. The cuff 10 is of an elastic material, such as a silicone rubber, natural or synthetic latex, and closely embraces the shaft in its uninflated state. The cuff 10 is about 70mm long, that is, its length is about 35 times the diameter of the shaft. The minor, inflation lumen 3 opens to the interior of the cuff 10 through two openings 13 and 14 formed through the outer wall of the shaft 1 and located within the cuff about 6mm from opposite ends 11 and 12.

A Y-connector 20 is moulded onto the rear end of the shaft 1, the connector having two side arms 21 and 22 that make fluid connection with the major lumen 2 and the inflation lumen 3 respectively.

A flexible fluid line 23 is bonded at one end into the side arm 21 of the connector 20 and at its other end is bonded to a female luer connector 24. Optionally, a stopcock 25 may be attached with the connector 24. A second flexible, inflation line 26 is bonded at one end into the other side arm 22 of the connector 20 and at its other end is bonded to an inflation indicator balloon 27 and a combined female connector and valve 28. The connector 28 includes a conventional, normally-closed spring-loaded valve, which can be opened by inserting the nose of a syringe, not shown.

The catheter is introduced in the usual way through the cervical canal 30 so that the patient end 4 is located in the uterus 31 and so that the inflatable sealing cuff 10 extends through the cervical canal with opposite ends 11 and 12 projecting beyond the internal os 32 and the external os 33 respectively. The length of the cuff 10 is specifically selected to be longer than the cervical canal 30 in the patient within which the catheter is being used, but this may vary from patient to patient according to her build. A syringe is then connected to the valved connector 28 on the inflation line 26, to open the valve, and a metered volume of fluid (usually air or saline solution) is supplied to the cuff 10 via the openings 13 and 14 so that it is inflated to the extent shown in Figure 3. The cuff 10 is inflated sufficiently for opposite ends of the cuff, located outside the cervical canal 30 to expand and contact the tissue around the internal os 32 and external os 33. The two openings 13 and 14 ensure that fluid is not prevented from entering the ends of the cuff 10 because of pressure applied to the cuff by tissue of the cervical canal 30. There will usually be little expansion of the cuff 10 within the cervical canal 30. In this way, a double seal is formed, with both the internal os 32 and the external os 33. The inflation of opposite ends 11 and 12 of the cuff 10 produces a self-centring effect and ensures that both inflated portions are held in contact with the tissue around the respective os.

Once the cuff 10 has been inflated, fluid can be supplied to the uterus 31 via the main bore 2 of the catheter, by connecting a fluid-filled syringe or similar device, not shown, to the connector 24 or stopcock 25, where this is used. After use, the cuff 10 is deflated by reconnecting a syringe to the connector 28 and applying suction. The catheter can then be removed.

The catheter of the present invention enables fluids to be infused to the uterus with a minimum of leakage. The invention could be used in other uterine catheters including catheters located in the cervix and providing a passage through which other catheters can be inserted into the uterus.