Cervical cerclage device

Abstract

The utility model relates to a cervical cerclage device which comprises a suture needle and a cerclage belt, the suture needle is a hollow suture needle internally provided with an air passage, one end of the suture needle is provided with a needle tip, the other end of the suture needle is detachably connected with the cerclage belt, a ventilation cavity communicated with the air passage is arranged in the cerclage belt, and the ventilation cavity is communicated with the air passage. A plurality of elastic membrane bags are arranged on the outer wall of the cerclage belt at intervals, an inflation cavity is formed between the elastic membrane bags and the outer wall of the cerclage belt, and the inflation cavity is communicated with the ventilation cavity through air holes formed in the outer wall of the cerclage belt. According to the cerclage wire, the contact area between the cerclage wire and the cervix uteri can be increased while cerclage of the cervix uteri is achieved and the treatment effect is guaranteed, and damage to the cervix uteri caused by the cerclage wire is effectively relieved.

Description

Technical field:

[0001] The utility model relates to the technical field of surgical instruments, devices or methods, and in particular to a cervical cerclage device. Background technology:

[0002] Cervical insufficiency refers to the disappearance or thinning of the cervix before full-term pregnancy, which leads to dilation of the cervical canal and eventually adverse pregnancy outcomes such as miscarriage and premature birth, with an incidence rate of 0.5%-1.0%. Cervical cerclage is an effective procedure for the treatment of cervical insufficiency, which can improve the pregnancy outcomes of patients with singleton pregnancy and cervical insufficiency. There are two commonly used cervical cerclage procedures during pregnancy, one is the Shirodkar method and the other is the McDonald cerclage, both of which require the use of sutures to cervical cerclage. The patent application number CN201720945786.3 provides a surgical suture for laparoscopic cervical cerclage, the suture comprising: a suture wire, a first straight suture needle connected to the first end of the suture wire, and a second straight suture needle connected to the second end of the suture wire; wherein the suture wire is a multi-strand braided wire. The patent designs the suture needles at both ends of the suture wire as straight suture needles, making the suture more suitable for the use of the new surgical procedure of laparoscopic cervical cerclage. The patent with patent application number CN202211313778.9 discloses a gradient cervical cerclage bandage, including sutures and suture needles. The suture needles are connected at both ends of the suture, and the suture needles are passed through the corresponding points of the cervix. The suture is tightened to make the cervix contract and produce resistance to entry and exit. The cervical cerclage is completed by cutting the suture needle and making a simple surgical knot. The cervical cerclage bandage in this patent adopts a gradual setting. The bandwidth of the first and second gradient sections of the suture gradually decreases from the equal width section to the suture needle end, which causes little damage to the tissue, and the two ends of the suture are made of thin wires, which can be used for smaller suture needles. However, since there is no standard for the sutures required for cervical cerclage at present, the cervix is ​​soft during pregnancy. If the existing sutures are too sharp, it is easy to cause cervical lacerations. If the elasticity is too large, the expected cerclage effect cannot be achieved. Utility model content:

[0003] 1. Technical issues to be resolved

[0004] The utility model aims to provide a cervical cerclage device to solve the problem in the prior art that sutures after cervical cerclage are prone to cause cervical lacerations and the cerclage effect is poor.

[0005] (II) Technical solution

[0006] In order to solve the above technical problems, the utility model adopts the following technical solutions: a cervical cerclage device, comprising a suture needle and a cerclage band, the suture needle is a hollow suture needle with an airway provided therein, one end of the suture needle is provided with a needle tip, and the other end of the suture needle is detachably connected to the cerclage band, a ventilation cavity connected to the airway is provided in the cerclage band, a plurality of elastic membrane bags are provided on the outer wall of the cerclage band at intervals, an inflation cavity is provided between the elastic membrane bag and the outer wall of the cerclage band, and the inflation cavity and the ventilation cavity are connected through air holes provided on the outer wall of the cerclage band.

[0007] The suture needle is used to pull the cerclage band to perform a suture needle cerclage operation on the cervix. During the cerclage operation, the needle tip can be connected to an inflation device, and air can be inflated into the cerclage band through the ventilation cavity. The gas enters the inflation cavity through the air hole to expand the elastic membrane bag, thereby increasing the contact area between the cerclage band and the cervix, reducing the pressure of the cerclage band on the cervical tissue, and avoiding cutting. At the same time, the expansion of the elastic membrane bag can also increase the cerclage force on the cervix to ensure the cerclage effect. There are several elastic membrane bags, and they are arranged at intervals. Since the suture needle punctures the cervix at intervals, the elastic membrane bags are fixed on the cervix in sequence from the tail end to the head end of the cerclage band. Each time one elastic membrane bag is fixed, the ventilation cavity is inflated through the needle tip to expand and fix it. After the inflation is completed, the cerclage band is knotted under the winding and puncture operation of the suture needle to close the ventilation cavity at the corresponding position to ensure that the air pressure in the elastic membrane bag is stable, while the unclosed ventilation cavity remains connected to the needle tip, and excess gas can be released from the needle tip to keep the other unclosed elastic membrane bags in a contracted state, which is convenient for continuing puncture and cerclage. By repeating this reciprocating operation, several elastic membrane bags can be fixed on the cervix in a ring shape to fix the cervical cerclage.

[0008] Furthermore, an insertion head is provided at one end of the suture needle connected to the cerclage band, and a binding groove is provided on the insertion head, and the suture needle and the cerclage band are connected via a binding groove. The insertion head is used to insert into the ventilation cavity of the cerclage band to connect the suture needle to the cerclage band, and the binding groove is used to bind the suture needle to the cerclage band tightly, and the binding groove is wound in the binding groove to ensure a firm connection without affecting the patency of the ventilation cavity.

[0009] Furthermore, a sealing block and a plugging head are provided in the airway, a vent hole is provided on the sealing block, the plugging head cooperates with the vent hole, the plugging head is connected to a push block provided on the outside of the suture needle through a connecting rod, a slide groove is provided on the outer wall of the suture needle, the connecting rod passes through the slide groove, an elastic sealing belt for sealing the slide groove is provided in the slide groove, and both sides of the connecting rod are connected to the elastic sealing belt. The plugging head can be moved by the push block operation to control the opening and closing of the vent hole. When it is necessary to inflate the ventilation cavity to expand the elastic membrane bag, the plugging head is separated from the sealing block by controlling the vent hole to open the vent hole, and then the needle tip is connected to the inflation device for inflation. After inflation, the vent hole is closed by controlling the plugging head to ensure the sealing of the ventilation cavity and avoid gas leakage causing insufficient inflation of the elastic membrane bag.

[0010] Furthermore, the vent hole is a conical hole, the plugging head is a conical head, the plugging head matches the vent hole, a raised ring is provided on the plugging head, an elastic ring is provided in the vent hole, and the outer diameter of the raised ring is greater than the inner diameter of the elastic ring. The raised ring is used to cooperate with the elastic ring to improve the effectiveness and stability of the seal and avoid the free slip of the plugging head resulting in poor sealing effect.

[0011] The cervical cerclage device of the utility model also includes an inflatable cylinder used in conjunction with the suture needle, the inflatable cylinder includes a cylinder body and an elastic rubber block arranged in the cylinder body, a piston is also arranged in the cylinder body, and the piston is connected to a push rod. When the cerclage band needs to be inflated, the needle tip of the suture needle is inserted into the cylinder body through the elastic rubber block, and the piston is pushed to inflate, which is convenient for repeated inflation operations.

[0012] Furthermore, a barrier net is provided in the cylinder, and the barrier net is provided between the elastic rubber block and the piston. The barrier net is used to limit the insertion depth of the needle tip into the cylinder, so as to prevent the needle tip from being inserted too deeply and puncturing the piston to affect the inflation effect.

[0013] Furthermore, the cerclage band is a low-elastic medical plastic band or a medical rubber band, and the elasticity of the cerclage band is less than the elasticity of the elastic membrane bag. When the low-elastic cerclage band is filled with gas in the ventilation cavity, it can avoid itself from expanding too much, which affects its penetration in the cervical tissue, and the gas in the ventilation cavity mainly enters the elastic membrane bag to expand the elastic membrane bag.

[0014] Furthermore, several of the elastic membrane bags are made of materials with different elasticity, and their elasticity increases successively as the position of the elastic membrane bag approaches the tail of the cerclage band. When the elastic membrane bag is inflated, due to the different elasticity of each elastic membrane bag, the gas will preferentially flow into the elastic membrane bag with large elasticity, and expand from the tail of the cerclage band to the head in sequence, which is consistent with the order of tying and fixing the elastic membrane bag during cervical cerclage, effectively improving the convenience of operation.

[0015] (III) Beneficial effects

[0016] Compared with the prior art, the beneficial effects produced by the utility model are as follows: by providing a suture needle and a cerclage band that are detachably connected to each other, the suture needle is a hollow suture needle with an airway arranged inside, a needle tip is arranged at one end of the suture needle, a ventilation cavity connected to the airway is arranged inside the cerclage band, a plurality of elastic membrane bags are arranged at intervals on the outer wall of the cerclage band, an inflation cavity is arranged between the elastic membrane bag and the outer wall of the cerclage band, and the inflation cavity and the ventilation cavity are connected through the air holes arranged on the outer wall of the cerclage band; during the cerclage operation, air can be inflated into the cerclage band through the ventilation cavity, and the gas enters the inflation cavity through the air holes to expand the elastic membrane bag, thereby increasing the contact area between the cerclage band and the cervix, reducing the pressure of the cerclage band on the cervical tissue, and avoiding cervical injury. At the same time, the expansion of the elastic membrane bag can also increase the cerclage force on the cervix to ensure the cerclage effect. Description of the drawings:

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model, the drawings required for use in the embodiments are briefly introduced below.

[0018] Figure 1 It is a front view of the cervical cerclage device in the uninflated state according to the first or second embodiment of the utility model;

[0019] Figure 2 It is a front view of the cervical cerclage device in the inflated state according to the first or second embodiment of the utility model;

[0020] Figure 3 is a cross-sectional view of the cervical cerclage device described in Embodiment 1 of the present utility model;

[0021] Figure 4 It is a partial enlarged cross-sectional view of the insertion head of the cervical cerclage device described in Embodiment 1 or 2 of the present utility model;

[0022] Figure 5 It is a partial enlarged cross-sectional view of the elastic membrane bag of the cervical cerclage device described in Embodiment 1 or 2 of the utility model when it is expanded;

[0023] Figure 6 is a cross-sectional view of the cervical cerclage device described in Example 2 of the utility model;

[0024] Figure 7 It is a partial enlarged cross-sectional view of the occluding head portion of the cervical cerclage device described in the second embodiment of the utility model when it is not occluded;

[0025] Figure 8 It is a partial enlarged cross-sectional view of the occluding head of the cervical cerclage device according to the second embodiment of the utility model when the occluding head is occluding;

[0026] Fig. 9 It is a cross-sectional view of the inflatable cylinder of the cervical cerclage device described in the second embodiment of the utility model;

[0027] Fig.10 It is a schematic diagram of the cervical cerclage band of the cervical cerclage device of Embodiment 1 or 2 of the present utility model when in use;

[0028] In the figure: 1, suture needle; 2, cerclage band; 3, airway; 4, needle tip; 5, ventilation cavity; 6, elastic membrane sac; 7, inflation cavity; 8, air hole; 9, insertion head; 10, binding groove; 11, binding band; 12, sealing block; 13, plugging head; 14, vent hole; 15, connecting rod; 16, push block; 17, slide groove; 18, elastic sealing belt; 19, raised ring; 20, elastic ring; 21, inflation cylinder; 211, cylinder body; 212, elastic rubber block; 213, piston; 214, push rod; 215, barrier net; Specific implementation method:

[0029] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0030] Embodiment 1

[0031] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Fig.10 A cervical cerclage device shown includes a suture needle 1 and a cerclage band 2. The suture needle 1 is a hollow suture needle with an airway 3 provided therein. A needle tip 4 is provided at one end of the suture needle 1, and the other end of the suture needle 1 is detachably connected to the cerclage band 2. A ventilation cavity 5 connected to the airway 3 is provided inside the cerclage band 2. A plurality of elastic membrane bags 6 are provided at intervals on the outer wall of the cerclage band 2. An inflation cavity 7 is provided between the elastic membrane bag 6 and the outer wall of the cerclage band 2. The inflation cavity 7 is connected to the ventilation cavity 5 via an air hole 8 provided on the outer wall of the cerclage band 2.

[0032] Preferably, an insertion head 9 is provided at one end of the suture needle 1 connected to the cerclage band 2, and a binding groove 10 is provided on the insertion head 9, and the suture needle 1 and the cerclage band 2 are connected by a binding band 11. The insertion head 9 is used to insert into the ventilation cavity 5 of the cerclage band 2 to connect the suture needle 1 and the cerclage band 2, and the binding band 11 is used to bind the suture needle 1 and the cerclage band 2 tightly, and the binding band 11 is wound in the binding groove 10 to ensure a firm connection without affecting the patency of the ventilation cavity 5.

[0033] Preferably, the cerclage band 2 is a low-elastic medical plastic band or medical rubber band, and its diameter when inflated is no more than 5 mm, and the elasticity of the cerclage band 2 is less than the elasticity of the elastic membrane sac 6. The diameter of the elastic membrane sac 6 after expansion is between 0.5-1 cm, and when the low-elastic cerclage band 2 is filled with gas in the ventilation cavity 5, it can avoid itself from expanding too much, which affects its penetration in the cervical tissue, and the gas in the ventilation cavity 5 mainly enters the elastic membrane sac 6 to expand the elastic membrane sac 6.

[0034] Preferably, several elastic membrane bags 6 are made of materials with different elasticity, and their elasticity increases successively as the position of the elastic membrane bag 6 approaches the tail of the cerclage band 1. When the elastic membrane bag 6 is inflated, due to the different elasticity of each elastic membrane bag 6, the gas will preferentially flow into the elastic membrane bag 6 with large elasticity, and expand from the tail of the cerclage band 2 to the head in sequence, which is consistent with the order of tying and fixing the elastic membrane bag 6 during cervical cerclage, effectively improving the convenience of operation.

[0035] Embodiment 2

[0036] like Figure 1 , Figure 2 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 , Fig. 9 and Fig.10 A cervical cerclage device shown includes a suture needle 1 and a cerclage band 2. The suture needle 1 is a hollow suture needle with an airway 3 provided therein. A needle tip 4 is provided at one end of the suture needle 1, and the other end of the suture needle 1 is detachably connected to the cerclage band 2. A ventilation cavity 5 connected to the airway 3 is provided inside the cerclage band 2. A plurality of elastic membrane bags 6 are provided at intervals on the outer wall of the cerclage band 2. An inflation cavity 7 is provided between the elastic membrane bag 6 and the outer wall of the cerclage band 2. The inflation cavity 7 is connected to the ventilation cavity 5 via an air hole 8 provided on the outer wall of the cerclage band 2.

[0037] Preferably, an insertion head 9 is provided at one end of the suture needle 1 connected to the cerclage band 2, and a binding groove 10 is provided on the insertion head 9, and the suture needle 1 and the cerclage band 2 are connected by a binding band 11. The insertion head 9 is used to insert into the ventilation cavity 5 of the cerclage band 2 to connect the suture needle 1 and the cerclage band 2, and the binding band 11 is used to bind the suture needle 1 and the cerclage band 2 tightly, and the binding band 11 is wound in the binding groove 10 to ensure a firm connection without affecting the patency of the ventilation cavity 5.

[0038] Preferably, a sealing block 12 and a plugging head 13 are provided in the airway 3, a vent hole 14 is provided on the sealing block 12, the plugging head 13 cooperates with the vent hole 14, the plugging head 13 is connected to a push block 16 arranged outside the suture needle 1 through a connecting rod 15, a slide groove 17 is provided on the outer wall of the suture needle 1, the connecting rod 15 passes through the slide groove 17, an elastic sealing belt 18 is provided in the slide groove 17 to seal the slide groove 17, and both sides of the connecting rod 15 are connected to the elastic sealing belt 18. The plugging head 13 can be moved by the push block 16 to control the opening and closing of the vent hole 14. When it is necessary to inflate the ventilation cavity 5 to expand the elastic membrane sac 6, the plugging head 13 is separated from the sealing block 12 by controlling the vent hole 14 to open the vent hole 14, and then the needle tip 4 is connected to the inflation device for inflation. After inflation, the vent hole 14 is closed by controlling the plugging head 13 to ensure the sealing of the ventilation cavity 5 and avoid gas leakage causing insufficient inflation of the elastic membrane sac 6. The elastic sealing band 18 is used to close the slide groove 17 to ensure the sealing of the airway 3 when the push block 16 and the connecting rod 15 move.

[0039] Preferably, the vent hole 14 is a conical hole, the plugging head 13 is a conical head, the plugging head 13 matches the vent hole 14, a raised ring 19 is provided on the plugging head 13, an elastic ring 20 is provided in the vent hole 14, and the outer diameter of the raised ring 19 is greater than the inner diameter of the elastic ring 20. The raised ring 19 is used to cooperate with the elastic ring 20 to improve the effectiveness and stability of the seal and avoid the free slip of the plugging head 13 resulting in poor sealing effect.

[0040] The cervical cerclage device in this embodiment also includes an inflatable cylinder 21 used in conjunction with the suture needle 1. The inflatable cylinder 21 includes a cylinder body 211 and an elastic rubber block 212 disposed in the cylinder body 211. A piston 213 is also disposed in the cylinder body 211, and the piston 213 is connected to a push rod 214. When the cerclage band 2 needs to be inflated, the needle tip 4 of the suture needle 1 is inserted into the cylinder body 211 through the elastic rubber block 212, and the piston 213 is pushed to inflate, which is convenient for repeated inflation operations.

[0041] Preferably, a barrier net 215 is provided in the cylinder 211, and the barrier net 215 is arranged between the elastic rubber block 212 and the piston 213. The barrier net 215 is used to limit the insertion depth of the needle tip 4 into the cylinder 211, preventing the needle tip 4 from being inserted too deeply and piercing the piston 213 to affect the inflation effect.

[0042] Preferably, the cerclage band 2 is a low-elastic medical plastic band or medical rubber band, and its diameter when inflated is no more than 5 mm, and the elasticity of the cerclage band 2 is less than the elasticity of the elastic membrane sac 6. The diameter of the elastic membrane sac 6 after expansion is between 0.5-1 cm, and when the low-elastic cerclage band 2 is filled with gas in the ventilation cavity 5, it can avoid itself from expanding too much, which affects its penetration in the cervical tissue, and the gas in the ventilation cavity 5 mainly enters the elastic membrane sac 6 to expand the elastic membrane sac 6.

[0043] Preferably, several elastic membrane bags 6 are made of materials with different elasticity, and their elasticity increases successively as the position of the elastic membrane bag 6 approaches the tail of the cerclage band 1. When the elastic membrane bag 6 is inflated, due to the different elasticity of each elastic membrane bag 6, the gas will preferentially flow into the elastic membrane bag 6 with large elasticity, and expand from the tail of the cerclage band 2 to the head in sequence, which is consistent with the order of tying and fixing the elastic membrane bag 6 during cervical cerclage, effectively improving the convenience of operation.

[0044] The method of using the cervical cerclage device described in the utility model is as follows:

[0045] When performing the cervical cerclage operation, the suture needle 1 and the cerclage band 2 are first tied and connected by the bandage 11, and then the first needle suture is performed, and the elastic membrane sac 6 closest to the tail end of the cerclage band 2 is first made to fit the cervical periphery, and then the push block 16 is pushed to open the vent 14, and the needle tip 4 is inserted into the cylinder 211 of the inflation cylinder 21, and the piston 213 is pushed to inflate the cerclage band 2 through the airway 3 and the ventilation cavity 5, and the gas enters the inflation cavity 7 to expand the elastic membrane sac 6, thereby increasing the contact area between the cerclage band 2 and the cervix, reducing the pressure of the cerclage band 2 on the cervical tissue, and avoiding cutting. At the same time, the expansion of the elastic membrane sac 6 can also increase the cervical cerclage strength and ensure the cervical cerclage effect. After the elastic membrane sac 6 expands to a suitable volume, the suture needle 1 is used to continue to puncture and wrap around the cervix, and a section of the ventilation cavity 5 corresponding to its front end is tied tightly, so that the expanded elastic membrane sac 6 is closed, and the expanded state is maintained to avoid air leakage. If gas enters other elastic membrane bladders 6 during inflation, it can be squeezed by hand to make as much gas as possible enter the elastic membrane bladder 6 that needs to be inflated, or it can be released through the airway 3; if it is necessary to ensure the closure of the ventilation cavity 5 during suturing, the plugging head 13 can be pushed to close the vent 14 by pushing the push block 16, thereby improving the convenience of operation. After the inflated elastic membrane bladder 6 is closed, the vent 14 can be opened by operating the push block 16 to release the excess gas in the ventilation cavity 5, and the suturing and fixing operation of the next elastic membrane bladder 6 can be continued. Since there are several elastic membrane bags 6 and they are arranged at intervals, the puncture of the cervix by the suture needle 1 is also performed at intervals. Therefore, the elastic membrane bags 6 are fixed on the cervix from the tail end to the head end of the cerclage band 2 in sequence. Each time an elastic membrane bag 6 is fixed, air is inflated into the ventilation cavity 5 through the needle tip 4 to expand and fix it. After the inflation is completed, the cerclage band 2 is knotted under the winding and puncture operation of the suture needle 1, and the ventilation cavity 5 at the corresponding position is closed to ensure that the air pressure in the elastic membrane bag 6 is stable, while the unclosed ventilation cavity 5 is kept in communication with the needle tip 4, and the excess gas can be released from the needle tip 4 to keep the other unclosed elastic membrane bags 6 in a contracted state, which is convenient for continuing the puncture and cerclage; such reciprocating operation can make several elastic membrane bags 6 fixed on the cervix in a ring shape to fix the cervical cerclage.

[0046] In summary, the utility model provides a cervical cerclage device, which solves the problem in the prior art that sutures after cervical cerclage are prone to cause cervical lacerations and the cerclage effect is poor.

[0047] The present invention is described above by way of examples, but the present invention is not limited to the above specific embodiments, and any changes or modifications based on the present invention belong to the scope of protection required by the present invention.

Claims

1. A cervical cerclage device, comprising a suture needle and a cerclage band, characterized in that: The suture needle is a hollow suture needle with an airway provided therein, one end of the suture needle is provided with a needle tip, and the other end of the suture needle is detachably connected to the cerclage band, a ventilation cavity connected to the airway is provided in the cerclage band, a plurality of elastic membrane bags are provided at intervals on the outer wall of the cerclage band, an inflation cavity is provided between the elastic membrane bag and the outer wall of the cerclage band, and the inflation cavity is connected to the ventilation cavity via an air hole provided on the outer wall of the cerclage band.

2. A cervical cerclage device according to claim 1, characterized in that: An insertion head is provided on one end of the suture needle connected to the cerclage band, and a binding belt groove is provided on the insertion head. The suture needle is connected to the cerclage band through the binding belt.

3. A cervical cerclage device according to claim 1, characterized in that: A sealing block and a plugging head are provided in the airway, the sealing block is provided with a vent hole, the plugging head cooperates with the vent hole, the plugging head is connected to a push block arranged on the outside of the suture needle through a connecting rod, a slide groove is provided on the outer wall of the suture needle, the connecting rod passes through the slide groove, an elastic sealing belt is provided in the slide groove for sealing the slide groove, and both sides of the connecting rod are connected to the elastic sealing belt.

4. A cervical cerclage device according to claim 3, characterized in that: The vent hole is a conical hole, the plugging head is a conical head, a raised ring is arranged on the plugging head, an elastic ring is arranged in the vent hole, and the outer diameter of the raised ring is greater than the inner diameter of the elastic ring.

5. A cervical cerclage device according to claim 1, characterized in that: Also included is an inflatable cylinder used in conjunction with the suture needle. The inflatable cylinder includes a cylinder body and an elastic rubber block arranged in the cylinder body. A piston is also arranged in the cylinder body, and the piston is connected to a push rod.

6. A cervical cerclage device according to claim 5, characterized in that: A barrier net is arranged in the cylinder, and the barrier net is arranged between the elastic rubber block and the piston.

7. A cervical cerclage device according to claim 1, characterized in that: The cerclage band is a low-elastic medical plastic band or a medical rubber band, and the elasticity of the cerclage band is less than the elasticity of the elastic membrane bag.

8. A cervical cerclage device according to claim 1, characterized in that: The plurality of elastic membrane bags are made of materials with different elasticity, and the elasticity thereof increases in sequence as the position of the elastic membrane bag approaches the tail of the cerclage band.

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