Abstract:
In accordance with the invention, an intubation set is provided having an improved connector between the tube and a probe. In a preferred embodiment, the connector includes a deformable sleeve which at one end receives an end of the tube and at the other end is tapered to converge on the probe where it is permanently attached. The tube contains a solid insert which can be set in a compound such as silicone rubber and the sleeve is deformed radially inwardly to trap part of the tube containing the insert thereby locking the tube to the sleeve and hence to the probe. A method of making the intubation set is also provided. The invention also provides an improved intubation set for use in intubating the canaliculi without probing a healthy nasolacrimal duct.

Description:
FIELD OF THE INVENTION 
     The present invention relates to devices for intubating lacrimal ducts and more particularly to intubation sets for positioning a length of tubing in the lacrimal ducts. 
     BACKGROUND OF THE INVENTION 
     The insertion of an elongate length of tubing member in the lacrimal ducts is a common surgical procedure for reconstruction or other remedial purposes. Lacrimal fluid or tears are continuously supplied from the lacrimal gland to wash across the sclera and other conjunctival components and the cornea. The excess lacrimal fluid is drained through a network of passages commencing with the puncta which appear as small papilla adjacent the inner canthus or inner corner of the eye, the lacrimal fluid being collected in the lacrimal sac by a number of canaliculi connecting the puncta with the lacrimal sac. The lacrimal sac is drained through the nasolacrimal duct which passes into the inferior nasal meatus. This network of passages is referred to hereinafter as the lacrimal ducts. 
     Closures of the lacrimal ducts can occur as a result of congenital anomalies, accidents, inflammation, advanced aging, as well as other physiological conditions. The closures prevent drainage of tears so that the affected eyes are continually brimming over with fluid, causing much personal discomfort to the patient, and often causing infection and/or inflammation of the mucous membranes as well as other undesirable conditions. 
     Known devices for correcting blocked lacrimal ducts include an intubation set disclosed in U.S. Pat. No. 4,380,239 to Dr. John Crawford, et al. The intubation set includes a probe consisting of a light resilient wire which can be readily deflected through an angle of at least 90 degrees to permit the probe to pass from the nasolacrimal duct to the inferior nasal meatus. The probe has a tip or distal end which is slightly enlarged and rounded to limit the possibility of damage to tissue when the probe is inserted, and a proximal end provided with an enlargement. A very flexible tube of minimal rigidity has a first end which is in engagement over the wire at the proximal end and into contact with the enlargement. Adhesive can be used to improve the connection. 
     When in use, the probe is inserted through either an upper punctum or a lower punctum of the lacrimal ducts and is guided downwardly through the lacrimal ducts to the inferior nasal meatus whereupon a tool in the form of a hook (shown in the Crawford patent) is used to pull the probe through the nostril leaving a length of tubing extending through the full length of the lacrimal ducts. 
     Although the Crawford intubation set provides a relatively secure connection between the tube and the probe, in rare instances these components have been found to separate during the intubation procedure. The cause is believed to be contact with bony structure which tends to roll the tube off the wire. Although this event is unusual, it would be preferable to provide an intubation device which benefits from the principles taught in the Crawford patent and which also has a connection between the probe and the tube which is less likely to suffer from this problem. 
     It is also possible for a closure to occur in the canaliculi and not in the nasolacrimal duct. For instance, the canaliculi may suffer traumatic injury while the nasolacrimal duct remains unaffected. It is therefore also desirable to provide an intubation set adapted to position a length of tubing in the region of the canaliculi without probing the healthy nasolacrimal duct in order to facilitate intubation by a physician. 
     SUMMARY OF THE INVENTION 
     In accordance with an aspect of the invention, an intubation set is provided having an improved connector between a tube and a probe. In a preferred embodiment, the connector includes a deformable sleeve which at one end receives an end of the tube and at the other end is tapered to converge on the probe where it it is permanently attached. The tube contains a solid insert which can be set in a compound such as silicone rubber and the sleeve is deformed radially inwardly to trap part of the tube containing the insert thereby locking the tube to the sleeve and hence to the probe. A method of making the intubation set is also provided. 
     The invention also provides an improved intubation set for use in intubating the canaliculi without probing a healthy nasolacuimal duct. In this case the probe is bent into a predefined spiral configuration and preferably lies in a plane. A tip on the probe can be pulled out of the plane to create a spiral for easier insertion. The spiral can be clockwise or anticlockwise depending on which way the tip is pulled out of the plane. 
     These and other aspects of the invention will be better understood with reference to the following description and drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Preferred embodiments of the invention will now be described with reference to the drawing in which 
     FIG. 1 is a diagrammatic view of an intubation set according to a first preferred embodiment of the invention; 
     FIG. 2 is a side sectional view taken generally on line  2 — 2  of FIG.  1  and drawn to a larger scale to illustrate a connector used to attach a tube to a probe of the intubation set; 
     FIG. 3 is a diagrammatic view of part of an intubation set according to a second preferred embodiment of the invention; and 
     FIG. 4 is a diagrammatic view showing the intubation set of FIG. 3 in use to intubating the canaliculi of a patient. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Reference is first made to FIG. 1 which illustrates an intubation set designated generally by the numeral  20  according to a first preferred embodiment of the invention. The intubation set  20  can be used according to a procedure described in the aforementioned U.S. Pat. No. 4,380,239 to Dr. Crawford. The procedure has become well established and uses a tool described in the Crawford patent. The same tool can be used with the present intubation set  20  to pull the probe from the nasal passage. 
     The intubation set  20  preferably includes a pair of similar thin probes  22 ,  24  of a light stainless steel wire which can be resiliently deflected to pass from the nasolacrimal duct to the inferior nasal meatus. The probes  22 ,  24  have enlarged and olive-shaped tips  28 ,  30 , respectively, to limit the possibility of damage to tissue when one of the probes  22 ,  24  is inserted, and proximal end portions  32 ,  34  respectively. 
     It has been found that an olive-shaped tip meets with less resistance than a more rounded tip, as taught by the Crawford patent and results in easier insertion of the probe through the lacrimal ducts. 
     The end portions  32 ,  34  of probes  22 ,  24 , respectively, are securely coupled by connectors  33 ,  35  to respective first and second end portions  36 ,  38  of a very flexible resiliently deformable, medical grade silicone rubber tube  40  of minimal rigidity, as will be described. 
     A length of silk 6/O suture  41  extends through the tube  40  along its full length and is used to tie cut ends of the tube  40  together after the tube  40  has been positioned in the lacrimal ducts, as is common in the art. 
     FIG. 2 illustrates the connector  33  in more detail. This connector is also typical of connector  35  and connects the end portion  36  of the tube  40  to the proximal end portion  32  of the probe  22 . 
     A thin-walled stainless steel tubular sleeve designated generally by reference numeral  42 , has a tapered leading end  44 , a trailing end  46  and a crimped intermediate portion  50 . The leading end  44  is silver soldered to the end portion  32  of the probe  22  with a portion of the proximal end portion  32  of the probe  22  extending within the sleeve  42 . 
     The end portion  36  of the tube  40  extends inside the sleeve  42  and is secured by the combination of a cylindrical insert  48  of solid stainless steel, and the crimped portion  50  of the trailing end  46  of the sleeve  42  as will be described. 
     The insert  48  is assembled in the connector by first entering a first quantity of uncured silicone sealer  56  into the tube, followed by the insert  48  and finally by a second quantity of uncured sealer  52 . 
     After curing, the tube, together with a sealer and the insert  48 , is entered into the sleeve  42  and deformed by crimping to form the portion  50  which locks the tube in place. The cured silicone will combine with the insert  48  to create a structure which can not be withdrawn through the radially decreased crimped intermediate portion  50 . The resistance to separation is enhanced by the rigid insert  48  because the insert is larger than the internal diameter of the crimped intermediate portion  50 . Also, because the silicone locks the insert in the tube, the insert cannot escape from the tube to allow the tube to be removed without the insert. 
     The connector  33  provides a smooth tapered transition from the probe  22  to to a generally cylindrical portion  49  of the sleeve  42 . Consequently, as the intubation set  20  is advanced in the lacrimal ducts, the smooth transition will ensure there will be little likelihood of snags thereby minimizing the discomfort to the patient. 
     The dimensions and other characteristics of the intubation set  20  will now be discussed followed by a discussion of alternative structures. 
     The probes  22 ,  24  are of tempered stainless steel wire having a diameter of approximately 0.4 mm and exhibit a resistance to deflection to retain their original shape after being subjected to small deflections as they are moved through the lacrimal ducts. Such fine wires would, of course, puncture tissue if the ends of the wires did not include the enlarged tips  28 ,  30 . 
     The length of the probes  22 ,  24  is approximately 110 mm. The silicone rubber tube  40  has an outer diameter of about 0.6 mm, an inner diameter of about 0.3 mm and a length of about 300 mm. The sleeve  42  is deformable stainless steel having a length of about 11 mm. The generally cylindrical portion  49  of the sleeve  42  has an outer diameter of about 0.8 mm and an inner diameter of about 0.6 mm. 
     One of the advantages of the present invention is that there is provided a very secure means of connecting the tube  40  to the probes  22 ,  24  such that the risk of separation of the tube  40  from any one of the probes  22 ,  24  is minimized. 
     Many variations to the intubation set  20  thus described and the method of its manufacture are possible within the scope of the invention. For example, the length of the probe may range from about 50 mm to about 150 mm. 
     As well, the length of the sleeve may be from about 6 mm to about 16 mm. Further, the outer diameter of the generally cylindrical portion of the sleeve may be from about 0.7 mm to about 1.0 mm. 
     Additionally, the deformation of the sleeve resulting in portion  50  may be by any suitable method, including rolling or swaging. 
     The intubation set may consist of a single probe coupled to a tube rather than a pair of probes coupled to respective ends of a tube. 
     Further, the tube need not contain a length of silk suture extending therethrough. 
     Reference will now be made to FIGS. 3 and 4 which illustrate an intubation set designated generally by reference numeral  60  according to a second preferred embodiment of the invention. The intubation set  60  is specially adapted for intubating only the upper and lower canaliculi  62 ,  64  respectively, without probing the nasolacrimal duct  66  (FIG.  4 ). Thus, the intubation set  60  is to be preferred to the intubation set  20  when a blockage occurs only in the canaliculi of the patient. In such case, it would be simpler and easier to probe the canaliculi using the intubation set  60  than to probe the canaliculi and nasolacrimal duct using the intubation set  20 . 
     The intubation set  60  is similar in every respect to the intubation set  20  except for the dimensions of the component parts, and the configuration and material of the probes. Specifically, the intubation set  60  includes a pair of similar spiral probes  68 , (one of which is shown) bent into a predefined spiral shape. The probe is a resilient, stiff, stainless steel wire having a proximal end portion  74  secured to a portion  70  of a very flexible resiliently deformable silicone rubber tube  72  of minimal rigidity containing a length of 6/0 silk suture  83  extending through the full length of the tube  72 . 
     The intubation set may be used in two ways. One ways illustrated in FIG. 4, is to insert the probe through an upper punctum  80 , feed the probe into the upper canaliculus  62 , move the probe downwardly into and through the lower canaliculus  64 , and finally move the probe out through the lower punctum  82 . The probe  68  is then pulled away from the patient by the tip  76  until a portion of the tube  72  is positioned through the canaliculi. Afterwards, the tube  72  is cut in two locations adjacent respective upper and lower puncta  80 ,  82 . Portions of the tube  72  near the cut ends thereof are peeled away revealing ends of the silk suture  83  which are then tied together, thereby forming the portion of the tube  72  retained in the canaliculi into a loop, in accordance with established practice. 
     Another method of using the intubation set  60 , which is not illustrated, involves inserting one of the spiral probes through one of the upper and lower puncta, inserting the other of the spiral probes through the other of the upper and lower puncta, and feeding the probes through respective canalicula until they meet at a location where the canaliculus is severed due to trauma to the region. The probes are then removed through an incision or open wound in the patient at the severed location, thereby leaving a length of tubing in the canaliculi. The tube is then cut in two locations adjacent the incision or wound, to form cut ends of the tube and suture. The cut ends of the tube are peeled away to reveal cut ends of the silk suture, and the cut ends of the silk suture are then tied together to form the tube into a loop. 
     The intubation set  60  further includes connectors  84  (one of which is seen) coupling the probe  68  to the tube  72  in the same manner as described with reference to the intubation set  20 . 
     The wire of the probe has a diameter of about 0.6 mm and a length of about 50 mm. 
     As in the case of the intubation set  20  according to the first preferred embodiment, variations to the second preferred embodiment are possible without departing from the scope of the invention. 
     For example, the probe set shown in FIGS. 3 and 4 has a different use from the probe set  20  and may be made using known connections between the tube and the probes while still providing a novel structure. The spiral probe may be secured to the silicone tube in any number of ways such as by using an adhesive or the joint taught in U.S. Pat. No. 4,380,239 to Crawford et al. 
     The spiral probe may be made of annealed stainless steel which is more easily deformable and less resilient. 
     The wire of the probe may have a diameter of from about 0.4 mm to about 0.8 mm, and a length of from about 37 mm to about 75 mm. 
     The intubation set may consist of a single spiral probe secured to a tube rather than a pair of spiral probes secured to respective end portions of a tube. 
     It should be understood that the foregoing description of the preferred embodiments are by way of example only and should not be construed as limiting the scope of the invention as defined by the following claims.