Everting gynecological brachytherapy applicator
An everting applicator for brachytherapy of body cavities such as the vagina has a flexible sleeve secured to a distal mandrel, both the sleeve and the mandrel having internal lumens. The flexible sleeve has a diverging opening at its distal end, preferably bell-shaped or cone-shaped, such that when the open end is pushed against the mouth of a vagina, the sleeve will evert back upon itself, progressively unrolling to an inside out configuration wherein, fully inserted, the sleeve is fully everted back over the exterior surface of the mandrel. A radiation source, isotopic or electronic, is then inserted into the mandrel lumen to commence a therapeutic irradiation procedure of tissues of the vagina.
1 . A gynecological brachytherapy applicator, comprising:
a flexible generally tubular sleeve of rubbery elastomeric material, having an internal lumen, the sleeve having a sleeve body and a distal end wider than the sleeve body and configured to prevent entry into a body cavity, the lumen terminating at a distal end opening,
a mandrel having an internal mandrel lumen of sufficient size to receive a radiation source inserted into the mandrel lumen and having a distal end connected to a proximal end of the flexible sleeve, and
the flexible sleeve having bending flexibility so as to evert when the distal end of the sleeve is braced against or adjacent to the exterior end of a body cavity such as a vagina and pushed so that the flexible sleeve everts as it enters and extends into the body cavity, with an inner wall of the sleeve's lumen turning outwardly in progressively unrolling contact against the interior surface of the body cavity until the outer surface of the flexible sleeve deeply overlaps the mandrel and engages against the outer surface of the mandrel, with the mandrel thus extending at least partially into the body cavity surrounded by the everted flexible sleeve.
2 . The applicator of claim 1 , wherein the mandrel is stiffer than the flexible sleeve.
3 . The applicator of claim 2 , wherein the mandrel is integrally formed with the flexible sleeve.
4 . The applicator of claim 2 , wherein the distal end of the mandrel is bonded to the proximal end of the flexible sleeve.
5 . The applicator of claim 1 , wherein the mandrel has a closed distal end, not in communication with the lumen of the flexible sleeve.
6 . The applicator of claim 1 , wherein the mandrel has an open distal end in communication with the lumen of the flexible sleeve.
7 . The applicator of claim 1 , wherein the material of the flexible sleeve comprises a silicone elastomer.
8 . The applicator of claim 1 , wherein the material of the flexible sleeve comprises a thermoplastic elastomer.
9 . The applicator of claim 1 , wherein the mandrel has a larger diameter than the flexible sleeve in non-everted configuration.
10 . The applicator of claim 1 , wherein said wider distal end comprises an end that diverges to larger diameter and defines an open end larger than the lumen in the sleeve body.
11 . The applicator of claim 10 , wherein the diverging distal end of the flexible sleeve is generally cone-shaped.
12 . The applicator of claim 11 , wherein the flexible sleeve includes a cuff around the enlarged open end, the cuff comprising an annular lip of thicker material than the rest of the flexible sleeve.
13 . The applicator of claim 1 , wherein the flexible sleeve has embedded within it longitudinally extending reinforcing members to inhibit stretching of the flexible sleeve in the everted portion, as the sleeve is pushed into a body cavity.
14 . The applicator of claim 12 , wherein the reinforcing members comprise cords formed of braided or stranded polyester fibers, molded within or attached to the walls of the flexible sleeve.
15 . The applicator of claim 1 , wherein the flexible sleeve has embedded within it longitudinally extending reinforcing members which help control the radius of bending of walls of the flexible sleeve as the flexible sleeve everts as the sleeve is pushed into a body cavity.
16 . The applicator of claim 15 , wherein the reinforcing members are superelastic Nitinol.
17 . The applicator of claim 1 , wherein the flexible sleeve includes longitudinally extending grooves in the surface of the sleeve which becomes the outer surface when the sleeve is everted, the grooves being effective to facilitate fluid transport along the applicator when the everted flexible sleeve is within a body cavity.
18 . The applicator of claim 1 , further including a radiation sensor with means for communication to a processor, to facilitate monitoring of radiation from a radiation source during an irradiation procedure in a body cavity.
19 . The applicator of claim 1 , wherein the exterior surface of the non-everted sleeve and the exterior surface of the mandrel include eversion locking means to hold an everted position of the applicator when said exterior surface of the everted sleeve is in contact with the exterior surface of the mandrel.
20 . The applicator of claim 19 , wherein the locking means comprises a series of holes or notches on one of the exterior surfaces of the mandrel and the sleeve, and at least one pawl or pin forward on the other of the exterior surfaces, for engagement of one or more pawls or pins in one or more of the holes or notches.
21 . The applicator of claim 1 , further including depth calibration markings on the exterior surface of the mandrel, for indicating the degree of eversion of the sleeve over the mandrel.