Patent Publication Number: US-2023149673-A1

Title: Curved balloon catheter retractor

Description:
FIELD OF THE INVENTION 
     The present invention relates to a catheter retractor, and more particularly to a curved balloon catheter retractor. 
     BACKGROUND OF THE INVENTION 
     The retractor is also referred to as a drag hook or retractor for retracting tissue, exposing a desired surgical range, facilitating exploration and operation, and may be divided into two categories: a hand-held pull hook and an automatic pull hook. There are various specifications and sizes of different shapes and sizes, and a suitable hook can be selected according to the operation requirements. 
     Conventional retractors require a larger operating space, which requires a larger surgical wound. At the same time, most of the traditional retractors are made of metals, and usually with a sharp end, which is easy to cause secondary trauma to the patient and damage important organ tissue. 
     Currently, retractable tissue retractors are widely used, and can be passed through the working channel of the retractable endoscope. Tissue retractors are used in endoscopic and open surgeries, including retractable endoscopic, laparoscopic, and general surgical procedures. In order to accommodate specific requirements of surgeries, the length and diameter of such a tissue retractor may be fixed or may vary. A retractable endoscope can be used to fix or secure the organ tissue, to pull it and to operate on it in some manner. 
     The catheter retractor is used for tissue retraction in surgery, which completes the retraction operation through natural lumen interventional surgeries or open surgeries. Surgeries include, but are not limited to, various laparoscopic surgery, cardiovascular surgery, brain surgery, gastrointestinal surgery, urinary surgery, etc. Tissue for retraction including but not limited to gastrointestinal tract, esophagus, airway, urethra, vagina, bladder, etc. The purposes of retraction include, but are not limited to, protecting a particular tissue, and/or removing a particular tissue to facilitate surgical operations. 
     The following example uses atrial fibrillation ablation complications to introduce the use and action of the catheter retractor. Atrial fibrillation is the most common arrhythmia, while atrial fibrillation ablation therapy has been gradually recognized in recent years as a better solution than drug therapy and conventional surgical procedures. The atrial fibrillation catheter ablation surgical therapy technology was reported for the first time in 1996, and has gradually become a clinically mature treatment technology after 20 years of technological progress and experience accumulation. The surgical success rate and the complication rate of atrial fibrillation ablation are all improved year by year, but the serious complication rate thereof is still 1%-3%. The more experienced an operator or surgeon is, the lower the probability of complications. If the atrial fibrillation ablation procedure is expected to be more commonly used in hospitals, improving the safety indicator is most important, and the following complications need to be well controlled. 
     Stroke (Cause: Scab and Thrombus Shedding in Intraoperative Wound), Incidence: 0.1%-0.5%. Heart perforation (Cause: mechanical trauma due to ablation), Incidence: 0.2%-0.5%. Pulmonary vein stenosis (Reason: too deep ablation or ablation site), Incidence: &lt;0.1%. Left Atrial Esophageal Fistula (Cause: ablation causes injury to esophagus), Incidence: 0.3-0.5%, Mortality: &gt;75%. 
     The occurrence of atrial esophageal fistula (“AEF”) complications arises from the spatial relationship between the left atrium and the esophagus. Since the esophagus is behind the posterior mediastinum, the posterior wall of the left atrium is only spaced from the pericardial sinus, while the posterior wall of the left atrium and the anterior wall of the esophagus are both thin, and high energy used in the ablation procedure is likely to cause excessive damage to the esophagus. AEF complications have the following characteristics: extremely high mortality, current rescue success cases are very few, and treatment means are very limited. It has been found that the diagnosis difficulty is high, since the symptoms of AEF complications usually occur after several weeks to months post-surgery. 
     By reducing the lethal rate of the procedure, the failure rate of the procedure and the occurrence of doctor-patient disputes will be reduced. Some patients avoid surgery due to fear of the occurrence of AEF complications and lose the opportunity to cure atrial fibrillation. If the occurrence of esophageal fistula can be effectively prevented, many patients who have worried the risk of AEF will be willing to receive AF surgical ablation treatment. In addition, the physician surgeons usually reduce the ablation power used during surgery in order to reduce the risk of AEF complications. As a result, the radical cure rate of the ablation procedure is reduced. By preventing the occurrence of the esophageal fistula, the doctor can perform ablation work on the region near the esophagus using the normal power, thereby improving the root treatment rate of atrial fibrillation. 
     For the patient with AEF, the esophagus and the left atrium are usually too close (about 1 cm), therefore the energy used during the atrial fibrillation ablation surgery can easily injure the esophagus. The technology of esophagus retraction fundamentally solves this problem. It has been proved that the method has a good effect on the control of esophageal injury and the prevention of AEF complications. Therefore the safety and effectiveness of the esophageal retraction are both preliminarily verified. 
     In a study presented at the 2017 A F Symposium, an International Atrial Fibrillation Symposium (“2017 A F Symposium”), a study of 101 patients who had atrial fibrillation ablation with esophageal retraction showed that none of the patients&#39; esophagus temperatures exceeded 38° C. in the study. The study simultaneously recorded various side effects of the digestive tract of 101 patients, such as dysphagia, blood circulation, dyspepsia, and other gastrointestinal symptoms, and follow-up for at least 6 months. The follow-up results showed that only a few patients had dysphagia (occurrence rate of 7%), which occurs immediately after operation and is completely relieved in several days, and no gastrointestinal complications were observed afterwards. 
     At present, most tools for esophageal retraction used in the research are devices without bendable ends and not special made for retraction, such as tracheal probes, endoscopes, etc. These devices have clinical problems such as complex operation procedures, limited retraction deviation distance, and incapability of completely adapting to esophageal structures. 
     In order to make the mechanical structure generate enough rigidity to achieve a satisfactory pulling effect, the mechanical structure generally has a larger diameter, so that the mechanical structure can only be inserted into the esophagus through the mouth, and more discomfort is brought to the patient. Meanwhile, due to the large diameter, the mechanical structure is limited in application field, and cannot be applied to other narrow and structurally complex human cavities. 
     SUMMARY OF THE INVENTION 
     The purpose of the present invention is to provide a curved balloon catheter retractor for natural lumen or cavity intervention or open surgical intervention based on the above problems, and to solve the problem that current catheter retractors are complex in structure, cannot accurately control the pulling force, and have low reliability, thereby achieving a simple and reliable catheter retraction and retractor. 
     In order to achieve the above object, the present invention provides a curved balloon catheter retractor. The distal end of the catheter is provided with a positioning balloon. There is a curved balloon close to the distal end. The positioning balloon and the curved balloon are connected to respective injection ports at the proximal end of the catheter through lumens inside the catheter. The proximal end of the catheter is provided with a handle for adjusting the position of the catheter. In the unused state, the positioning balloon and the curved balloon are tightly attached to the catheter; while in the use state, fluid is injected by the injection port of the positioning balloon, and the positioning balloon is inflated to achieve the positioning effect; and then the fluid is injected into the curved balloon, so that the curved balloon and the catheter portion in the curved balloon are bent or in a bended or curled position, and the retraction is achieved by deviating or shifting the tissue or organ to one side. 
     In the unused state, the positioning balloon and the curved balloon are tightly attached to the catheter and covered by a rigid tubular protective shield. The balloon protective shield is removed when the balloon is in use. The handle has a length scale portion for marking the depth of the catheter insertion. The catheter is made of a material that is not easily twisted, or the catheter is reinforced with a material that is not easily twisted. There are three radiopaque parts or developing devices in the curved balloon, which are used for displaying the relative positions of the proximal end, the middle part and the distal end of the curved balloon respectively. A radiopaque line is provided on the catheter for display under X-ray, for development and use. The length of the curved balloon is preferably 9-11 cm. The number of curved balloon segments is in the range of 5 to 8. 
     Further, the proximal end or tail portion of the catheter is provided with a main shaft for holding and rotating, and the proximal end of the main shaft is provided with a fixing screw for clamping the catheter passing through the interior of the main shaft. A head portion of the main shaft is provided with a locking sliding block for fixing or loosening the catheter passing through the interior of the main shaft for adjusting the position of the catheter. The main shaft head portion has two connecting buckles for connecting a fixing headband such that the main shaft and the entire catheter are fixed relative to the patient&#39;s head. 
     Further, one end of a high-pressure braided tube is further provided with a syringe, and another end of the high-pressure braided tube is connected with an injection port of the curved balloon or positioning balloon at the distal end of the catheter. A two-way valve is further provided with a switch in the middle of the two-way valve. The two-way valve can be connected between the injection port and the high-pressure braided tube when needed to control fluid injection so as to maintain the pressure within the balloon. 
     Preferably, the head band is further provided with a main body portion located at the back of the head, and the main body portion is provided with a large hole for accommodating a protruding portion at the back head, making it more comfortable to wear. The main body portion is provided with four connecting belts, and each connecting belt is provided with a string of connecting holes which can clamp and connect with the two connecting buckles of the head portion of the main shaft. 
     Preferably, a sheath tube is further provided, which is a hollow tube, and the sheath tube can form a fixed non-rotating protective portion, so that an upper portion of the natural lumen or human body cavity is not damaged by rotation of the catheter. A radiopaque line is embedded in the sheath tube, and the position and state of the sheath tube can be observed by X-ray development when entering and within the human body. The sheath tube is provided with a hole for spraying a developing solution to display the position where the curved balloon is placed or located. The bottom of the sheath tube is provided with a three-way round joint, and one end of the sheath tube is connected with the round joint, and one end of the round joint is connected with the main shaft so as to accommodate the catheter, and the side edge of the round joint is provided with a hole for injecting a developing solution. 
     Further, the sheath tube auxiliary device is a flexible or soft solid tube, and the solid tube has a smooth head and an oval bottom. The sheath tube auxiliary device is used to smoothly enter the human cavity by using the characteristics of the flexible solid tube, and meanwhile guide the sheath tube, so that the sheath tube is prevented from being inserted directly to the cavity in such a way as to cause the sheath tube edge to scratch the human cavity, such as the nasal mucosa or the esophageal wall. After the sheath tube is introduced into the cavity, the sheath tube auxiliary device can be pulled out smoothly. The catheter is then inserted into the sheath tube. 
     The beneficial effects of the present invention are as follows: the air bag or balloon structure is adopted, and compared with a metal structure, the air bag has better protection for the human tissue against the traction part, and does not easily puncture the human tissue. At the same time, the catheter can be made more flexible, the outer wall of the catheter is thinner, and the human body is more comfortable during insertion. Because the air bag is made of a non-compliant or semi-compliant material, the shape of the air bag can be controlled by the air pressure, and the traction can be accurately and reliably achieved. Because use of the air bag structure is adopted, the diameter of the air bag is small, the flexibility is high, the air bag can enter a narrow cavity or a complex cavity, and meanwhile the comfort degree of the patient is improved. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic structural view of a catheter portion according to the present invention. 
         FIG.  2    is a schematic view of a main shaft portion of the present invention. 
         FIG.  3    is a schematic view of the high-pressure braided tube and the two-way valve of the present invention. 
         FIG.  4    is a schematic view of the headband of the present invention. 
         FIG.  5    is a schematic view of a sheath tube of the present invention. 
         FIG.  6    is a schematic view of a three-way circular joint at the bottom of the sheath tube of the present invention. 
         FIG.  7    is a schematic diagram of the curved balloon catheter retractor after filling according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. 
     Referring first to  FIG.  1   ,  FIG.  1    is a schematic structural diagram of a catheter portion according to the present invention. As shown in  FIG.  1   , the distal end of the catheter  10  of the present invention has a positioning balloon  11 , the catheter  10  has a curved balloon  12  near the distal end, and the balloon  11  and the curved balloon  12  are respectively connected to respective injection ports at the proximal end of the catheter by lumens inside the catheter  10 . 
     The catheter  10  has a fixed handle  14  at the proximal end and a length scale portion  15  at a handle portion or handle  14 . 
     In the unused state, the positioning balloon  11  and the curved balloon  12  are attached to the catheter  10  covered by and within a rigid tubular protective shield or tube  16 . 
     In the use state, the balloon protective shield  16  is removed, and fluid is injected via the injection port of the positioning balloon  11 , and the positioning balloon  11  is inflated to clamp or move the esophagus or tissue, so as to play a role in positioning. Fluid is then injected into the curved balloon  12  such that the curved balloon  12  and the catheter  10  therein are partially curved or bent and the esophagus is deviated, pulled or moved to one side. 
     The user may adjust the position of the curved balloon  12  through use of the handle  14  and may estimate the relative position of the curved balloon  12  by the length scale portion  15  of the handle  14 . 
     The catheter  10  is made of a material that is not easily twisted, or may be a combination of a multi-lumen tube and a braided tube, or other combinations. When the part of catheter  10  left outside the human body cavity is rotated, the part of the catheter  10  within the cavity rotates at the same time by a certain proportion. At the same time, the catheter  10  has the length scale portion  15  for marking the depth of insertion of the catheter  10 . 
     The fluid used here is typically liquid and gas. When the curved balloon  12  is inflated with fluid, it is bent toward one side. In one embodiment, the fluid is injected through the injection port by a syringe. Closing the catheter and valve after injection of the fluid may cause the curved balloon  12  to maintain fluid pressure. Generally, the curved balloon  12  is located outside the catheter  10 , and the catheter portion where the positioning balloon  11  and the curved balloon  12  are located is provided with a radiopaque part so that its relative position can be displayed under X-rays. The radiopaque part may be a radiopaque material, such as tantalum, platinum iridium alloy, tungsten, etc. Other positioning devices, such as infrared or radio frequency tags, may also be used. In some embodiments, the catheter  10  is provided with a radiopaque line as a display under X-ray. There are three radiopaque parts within the curved balloon  12 , located at the proximal, middle and distal ends of the curved balloon  12  respectively, which may display the relative position of the curved balloon  12 , as well as the position of the largest curved or deviated portion. 
     In terms of the preferable length of the curved balloon  12 , because the curved balloon  12  curves, moves or deviates the esophagus by forming a semicircle, the deviation distance relates to the radius of the semi-circle. That is, the longer the curved balloon  12  is, the more pronounced the deviation effect is. However, due to the configuration of the human esophagus, the distance between the second and third esophagus constriction or stenosis is from 11 cm to 15 cm, which is related to the person&#39;s height. When the curved balloon  12  is bent, if the curved balloon is located at the esophagus constriction, the curvature is limited at the esophagus constriction. Therefore the length of the balloon should satisfy the distance between the second and third constriction or stenosis of all people, and the longer the length of the balloon is, the better. Therefore, the length of the curved balloon  12  is preferably 9-11 cm. 
     The shape of the curved balloon  12  is segmented, but the entirety is internally connected or in communication; a single segment cannot constitute a curved balloon. Regarding the preferable number of segments of the curved balloon  12 , the bending of curved balloon  12  is driven by the asymmetry of its shape and different degrees of expansion on both sides. The more segments there are, the increased asymmetry makes it easier for the curved balloon  12  to bend. If the curved balloon  12  bends into a semi-circle, it is the best. For two curved balloons  12  with different numbers of segments that are bent into the same semi-circle, a larger number of segments of the curved balloon  12  will make the diameter of the curved balloon  12  smaller, thereby reducing the stiffness of the curved balloon  12 . The curved balloon  12  needs to meet a certain rigidity after being bent into a semicircle, and therefore the preferable number of segments of the curved balloon  12  is from 5 to 8. 
     Please refer to  FIG.  2   , which is a schematic diagram of a main shaft portion or main shaft of the present invention in  FIG.  2   . The main shaft  20  is configured to hold or be held and to rotate. 
     A fixing screw  21  at the proximal end of the main shaft  20  can be used to clamp the catheter  10  passing through the main shaft  20 . The distal part of the main shaft  20  is provided with a locking slider  22  for fixing or loosening the catheter  10  passing through the main shaft  20  to adjust the position of the catheter  10 . 
     The distal portion of the main shaft  20  has two connecting buckles  23  for connecting a fixing headband so that the main shaft  20  and the entire catheter  10  are fixed relative to the head. 
     Referring to  FIG.  3   , which is a schematic diagram of a high-pressure braided tube and a two-way valve of the present invention. 
     One end of the high-pressure braided tube  30  is connected to the syringe  31 , and another end of the high-pressure braided tube  30  is connected to the injection ports  32  of the curved balloon  12  or the positioning balloon  11 . A switch  34  is provided in the middle of the two-way valve  33  and can be connected between the injection port  32  and the high-pressure braided tube  30  when needed for controlling fluid injection so as to maintain the pressure in the balloon. 
     Please refer to  FIG.  4   , which is a schematic diagram of the headband of the present invention. The headband  40  is formed by a main body portion  41  to located at the back of a head, and the main body portion  41  is provided with a large hole  42  for accommodating a protruding portion behind or at the back of the head, making it more comfortable to wear. The main body portion  41  is provided with four connecting belts  43 , and the connecting belt  43  is provided with a string of connecting holes  44  to clamp the two connecting buckles  23  at the head or head portion of the main shaft  20   
     Please refer to  FIG.  5   , which is a schematic diagram of the sheath tube of the present invention. The sheath tube  50  is a hollow tube, and the tube is provided with a hole  51  for spraying a developing solution to display the position of the sheath tube. At the same time, because the catheter  10  needs to be rotated and pulled in the cavity, if such operation of the catheter  10  is performed in a human body cavity, such as the nasal cavity, it may cause a risk of scratching damage. However, the sheath tube  50  can form a fixed non-rotating protective portion, so that the upper portion of the human body cavity is not damaged by rotation and pulling of the catheter. 
     Please refer to  FIG.  6   , which is a schematic diagram of a three-way round joint at the proximal end of the sheath tube  50  of the present invention. The proximal end of the sheath tube  50  is provided with a three-way round joint  52 , one end  53  of which is connected with the sheath tube, and another end  54  of which is connected with the main shaft  20  so as to accommodate the catheter  10 . A side of the sheath tube  50  is provided with a hole  55  for injecting a developing solution. 
     The sheath tube auxiliary device  56  is a flexible solid tube having a smooth head  57  and an elliptical bottom  58 . 
     The sheath tube auxiliary device  56  functions to smoothly enter the cavity by using the characteristics of the flexible solid tube, and simultaneously guide the sheath tube  50 , so as to prevent the sheath tube  50  from being directly inserted into the cavity, such as the nasal mucosa or the esophageal wall, and to prevent the cavity from being scratched by the edge of the sheath tube. After the sheath tube  50  is introduced into the cavity by the sheath tube auxiliary device  56 , the sheath tube auxiliary device can be pulled out smoothly. The catheter  10  is then inserted into the sheath tube  50 . 
       FIG.  7    is a schematic diagram of the curved balloon catheter retractor after inflation according to an embodiment of the present invention. In  FIG.  7   , the positioning balloon  11  and the curved balloon  12  at the distal end of the catheter  10  are in an inflated state. 
     The present invention also provides a retraction method, which can be expanded into an arc-shaped curved balloon  12  through a single-lumen/multi-lumen catheter, and which can be used to intervene or retract tissue in a human body. The curved balloon  12  is located outside the catheter  10 . The catheter  10  can be offset towards the convex direction of the curved balloon  12  and can be provided with an operating handle  14  and other related accessories for use in combination. The said curved balloon catheter retractor can be used in surgeries for tissue retraction which is accomplished through interventional procedures or surgeries. Procedures or surgeries include, but are not limited to, various laparoscopic procedures, cardiovascular surgery, brain surgery, digestive tract surgery, urinary surgery, etc. The tissue to be retracted includes, but is not limited to, gastrointestinal tract, esophagus, trachea, urethra, vagina, bladder, etc. The purpose of the retraction include, but are not limited to, protecting a particular tissue, or removing a particular tissue to facilitate operation. 
     The catheter  10  of the curved balloon  12  of the retractor is controlled by the handle  14  during use to intervene with tissue within the body. With the help of the image device, the position and rotation angle of the catheter  10  can be adjusted with the handle  14 . The positioning and angle can be locked with the set screw  21  on the main shaft  20 . Inflation of the curved balloon  12  may be accomplished by the fluid injection port  32  to which the handle  14  is attached, or any other pathway. The curved balloon  12  expands and is bent after being filled with fluid, and at least one section of the lumen or balloon of the catheter  10  is bent to varying degrees, and finally the bent portion of the catheter can achieve the effect of moving, pulling or deviating the tissue. 
     The effect of the catheter retractor is described by taking atrial fibrillation ablation complications as an example. Atrial fibrillation is the most common arrhythmia, while atrial fibrillation radiofrequency ablation therapy has been gradually recognized in recent years as a better solution than drug therapy and conventional surgical procedures. The occurrence of atrial esophageal fistula complications arises from the spatial relationship between the left atrium and the esophagus. Since the esophagus is located in the posterior mediastinum and is only separated from the posterior wall of the left atrium by the pericardial sinus, the posterior wall of the left atrium and the anterior wall of the esophagus are both thin, and high temperature and high energy used during the ablation procedure are likely to cause excessive damage to the esophagus. The atrial esophageal fistula complications have extremely high mortality. In order to make the surgery more safe, the esophagus must be pulled away from the heart. With the present invention, the catheter  10  provided with the curved balloon  12  is inserted into the patient&#39;s body cavity, and the curved balloon  12  is partially inserted into the desired position within the tissue to be retracted, or a desired positioning effect. The catheter  10  is filled with fluid to inflate the balloon. The curved balloon  12  bends and pulls the catheter  10  to curve or bend and causes the patient&#39;s body cavity, such as the esophagus, to move or bend, thereby achieving the deviation displacement. 
     When in use, the catheter  10  is inserted into the esophagus from the nasal cavity, and when the positioning balloon  11  at the distal end enters between the esophagus second and third constrictions, the positioning balloon  11  at the distal end is inflated and pushed to the third constriction. Then the curved balloon  12  in the middle is expanded to bend or curve and drive or move the esophagus to deviate. During use, the catheter  10  and the balloon are driven to rotate by rotating the handle  14 , so that the deviate direction of the esophagus changes, thereby avoiding the ablation point of the cardiac ablation all the time. The aperture may also be used to spray the developer such that the esophageal deviated portion and position is able to be seen or developed under x-rays. 
     Specifically, when the catheter is used for esophageal traction or retraction, the catheter is inserted into the esophagus through the nasal cavity or oral cavity first. After reaching the desired position, the relative position of the esophagus to the heart and bending or curving direction can be determined based on the markers  15  on the catheter  10  and the handle  14 . Then the curved balloon  12  is inflated with fluid and is stiffened to bend, move or deviate the esophagus to a desired retraction position. When the position of the curved, bent or retraction balloon is rotated and adjusted on the desired horizontal section (when the ablation point is changed during cardiac ablation), the entire catheter  10  is rotated through the handle  14 , and the curved balloon  12  is driven to rotate, thereby retracting the esophagus in a new direction to a new desired retraction position to make it stay away or keep it away from the new ablation point. The curved balloon  12  is located between the second and third constriction of the esophagus when the esophagus is deviated. The diameter of the positioning balloon  11  after expansion is greater than the diameter of the inner wall of the esophagus at the constriction. The length of the curved balloon  12  is 10-15 cm, the working air pressure is 2-8 atm, and the deviated displacement distance is 2-4 cm. Those skilled in the art can still make other modifications within the spirit of the present disclosure, and various modifications derived according to the spirit of the present disclosure shall fall within the scope of protection of the present disclosure.