Degradable spacer for pancreatic cancer radiotherapy

Abstract

The invention discloses a degradable spacer for pancreatic cancer radiotherapy, which is beneficial to postoperative recovery and subsequent radiotherapy of a patient through minimally invasive implantation compared with a spacer needing to be implanted through an open operation. After being flattened and curled, the isolation bag is implanted into the abdominal cavity, enters the body and then is unfolded and fixed, then degradable hydrogel is injected, compared with an isolation object in a fixed or semi-fixed shape, the deformation operation greatly increases the size and thickness of the isolation object, and the isolation effect is improved; the bag and the hydrogel of the spacer are both biodegradable materials, can be automatically absorbed in a body and do not need to be taken out through a secondary operation, in addition, the spacer is in a bag shape, the degradable hydrogel is injected through the small holes after the spacer is implanted and fixed in the body, compared with an air bag injected with air, the structural combination is more stable, and the structure is more convenient to use. Even if the bag is locally damaged due to operation or other reasons, the gel cannot flow out quickly due to the shape characteristic of the gel, and the shape of the bag can be basically kept relatively stable within a certain period of time.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, specifically to a biodegradable barrier for radiotherapy of pancreatic cancer. Background Technology

[0002] Radiotherapy is one of the important treatment methods for pancreatic cancer. However, the pancreas is close to radiation-sensitive organs such as the stomach, duodenum, and small intestine. When high-dose stereotactic radiotherapy is performed, these adjacent organs may be over-irradiated, leading to radiation damage such as ulcers, bleeding, and perforation. This severely limits the increase of radiotherapy dose and affects the treatment effect. To reduce irradiation of normal tissues, existing technologies have proposed methods for implanting physical spacers between the target area and sensitive organs. For example, Chinese patent CN 111569277A discloses a target spacer for radiotherapy, which is a sheet-like structure or a tubular structure enclosing the target area, constructed by connecting multiple spacer units. It is mainly used after esophageal cancer surgery, with a spacer distance of approximately 5 mm. However, the above-mentioned existing technologies have the following shortcomings: 1. The isolation space formed after implantation of sheet-like or tubular structures is limited. For stereotactic radiotherapy of pancreatic cancer that requires higher radiotherapy doses and greater isolation distances, the isolation effect may be insufficient. 2. Its structure may not be suitable for implantation through minimally invasive laparoscopic surgery. If open surgery is required, it will be more traumatic, have a slower recovery, and may delay subsequent radiotherapy. 3. If inflatable airbags are used as the isolation material, there is a risk of leakage. Once damaged, they will quickly become ineffective and cannot maintain a stable isolation distance. Therefore, we propose a novel isolation device that can be implanted minimally invasively, provides sufficient and stable isolation distance, and is biodegradable to avoid removal by a second surgery. Summary of the Invention

[0003] In view of the problems existing in the prior art, the present invention discloses a biodegradable spacer for radiotherapy of pancreatic cancer. The technical solution adopted is as follows: the biodegradable spacer includes a sac-like structure composed of two layers of biodegradable material. The biodegradable spacer has multiple strips inside, dividing the interior of the biodegradable spacer into multiple independent partition regions. The biodegradable spacer is provided with an injection port for injecting biodegradable hydrogel. As a preferred embodiment of the present invention, the degradable materials of the upper and lower layers of the spacer are polyglycolic acid. As a preferred embodiment of the present invention, the biodegradable spacer is divided into multiple independent partitions with a maximum height of 1 cm when fully inflated. As a preferred embodiment of the present invention, the biodegradable spacer can be flattened and rolled into a cylindrical shape in a non-implantable state so as to be implanted into the abdominal cavity through a laparoscopic channel. As a preferred embodiment of the present invention, the biodegradable hydrogel is a polyethylene glycol gel. As a preferred embodiment of the present invention, the biodegradable spacer has a wavy structure in cross-section. As a preferred embodiment of the present invention, the biodegradable spacer is located between the stomach, intestines and pancreas after implantation, and is used to provide an isolation distance of at least 10 mm in the pancreatic lesion during stereotactic radiotherapy. A method for implanting a biodegradable spacer for radiotherapy of pancreatic cancer, comprising the following steps: Step 1: Flatten and roll the biodegradable spacer capsule into a cylindrical shape; Step 2: The rolled-up cylindrical sac is implanted into the abdominal cavity through the laparoscopic channel; Step 3: Deploy and secure the sac within the abdominal cavity; Step 4: Inject biodegradable hydrogel into the capsule through the injection port to fill it into the predetermined shape.

[0004] The beneficial effects of this invention are as follows: The isolation device of this invention is implanted minimally invasively, which is beneficial to the patient's postoperative recovery and subsequent radiotherapy compared to isolation devices that require open surgery. The isolation bag is flattened and rolled up before being implanted into the abdominal cavity, then unfolded and fixed inside the body, and then injected with biodegradable hydrogel. Compared with isolation devices with fixed or semi-fixed shapes, this deformation operation greatly increases the volume and thickness of the isolation device, thus increasing the isolation effect. Both the isolation bag and the hydrogel are biodegradable materials that can be absorbed by the body without the need for a second surgery to remove them. In addition, the isolation device is bag-shaped, and after being fixed in the body, biodegradable hydrogel is injected through a small hole. Compared with air-filled balloons, this structural combination is more stable. Even if the bag is partially damaged due to operation or other reasons, the shape of the gel will not flow out quickly, and the shape of the bag can be maintained relatively stably for a certain period of time. The cross-sectional view of the bag is wavy, which, compared to a cubic shape, reduces the amount of biodegradable hydrogel injected while ensuring the isolation effect. Attached Figure Description

[0005] Figure 1 This is a schematic diagram of the structure of the biodegradable separator of the present invention in a fully filled state; Figure 2 A is a cross-sectional schematic diagram of the biodegradable separator of the present invention in a non-filled state; Figure 2 B is a schematic cross-sectional view of the biodegradable separator of the present invention in a fully filled state; Figure 2 C is a schematic diagram of a vertical cross-section of the biodegradable separator of the present invention in a fully filled state; Figure 3 A is a schematic diagram of the biodegradable separator of the present invention in a flattened state; Figure 3 B is a schematic diagram of the biodegradable separator of the present invention rolled into a cylindrical shape for implantation; Figure 4 A is a schematic diagram of the implantation of the spacer through the laparoscopic channel according to the present invention; Figure 4 B is a schematic diagram of the present invention involving fixing a spacer in the abdominal cavity and injecting hydrogel; Figure 5 A is a top view of the abdominal cavity after the implantation of the isolation device of the present invention is completed; Figure 5 B is a cross-sectional schematic diagram after the isolation device of the present invention has been implanted, showing its positional relationship between the isolated stomach, intestines and pancreas. In the image: 1. Degradable spacer; 2. Abdominal cavity; 3. Pancreatic lesion; 4. Pancreas; 5. Stomach; 6. Intestine. Detailed Implementation

[0006] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but the scope of protection of the present invention is not limited to the following embodiments. like Figures 1 to 2 As shown in Figure C, the biodegradable spacer 1 of the present invention is a bladder, the upper and lower layers of which are composed of biodegradable films made of polyglycolic acid; the interior of the bladder is divided into multiple interconnected compartments by several welded or sewn strips. This structure allows the bladder to maintain a predetermined shape and thickness after inflation and prevents excessive flow of the contents; the cross-section of the bladder is designed to be wavy, see [reference]. Figure 2 B, Compared to the cube design, this design effectively reduces the volume of filler while maintaining the same maximum isolation distance; the capsule is equipped with an injection port with a self-sealing valve; The implantation process of the spacer is as follows: First, such as Figure 3 A and Figure 3 As shown in B, the dried, flattened capsules are tightly rolled into a compact cylindrical shape in vitro.

[0007] Next, as Figure 4 As shown in Figure A, the curled sac is inserted into the abdominal cavity through a standard laparoscopic trocar.

[0008] Then, as Figure 4As shown in B, under laparoscopic vision, instruments are used to unfold the cyst at the target position, and absorbable sutures are used to fix it at a predetermined position in front of the pancreas 4. Then, a predetermined amount of polyethylene glycol gel is injected into the cyst through an injection catheter connected to the injection port to fully inflate it. Finally, withdraw the injection catheter and close the self-sealing valve at the injection port to prevent gel leakage.

[0009] like Figure 5 A and Figure 5 As shown in B, the implanted and filled barrier is located between the pancreas 4 and its pancreatic lesion 3 and the stomach 5 and intestine 6, forming a barrier of at least 10 mm. During stereotactic radiotherapy, this barrier can effectively attenuate the radiation dose and protect the stomach 5 and intestine 6 from high-dose radiation. After the radiotherapy cycle ends, the polyglycolic acid material that makes up the capsule will begin to hydrolyze and degrade, and the polyethylene glycol gel inside the capsule will gradually dissolve and be absorbed by the body. Eventually, the entire barrier will be completely metabolized and will not need to be removed by surgery again. Components not described in detail in this article are existing technologies. The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A biodegradable barrier for radiotherapy of pancreatic cancer, characterized in that, The invention includes a biodegradable spacer (1), which is a sac-like structure composed of two layers of biodegradable material. The biodegradable spacer (1) has multiple strips inside, which divide the interior of the biodegradable spacer (1) into multiple independent partition regions. The biodegradable spacer (1) has an injection port for injecting biodegradable hydrogel.

2. The biodegradable barrier for radiotherapy of pancreatic cancer according to claim 1, characterized in that: The degradable spacer (1) has two layers of degradable material made of polyglycolic acid.

3. The biodegradable barrier for radiotherapy of pancreatic cancer according to claim 1, characterized in that: The biodegradable spacer (1) is divided into multiple independent partitions with a maximum height of 1 cm when fully filled.

4. The biodegradable barrier for radiotherapy of pancreatic cancer according to claim 1, characterized in that: The biodegradable spacer (1) can be flattened and rolled into a tube in a non-implanted state so that it can be implanted into the abdominal cavity (2) through the laparoscopic channel.

5. A biodegradable barrier for radiotherapy of pancreatic cancer according to claim 1, characterized in that: The biodegradable hydrogel is a polyethylene glycol gel.

6. A biodegradable barrier for radiotherapy of pancreatic cancer according to claim 1, characterized in that: The biodegradable spacer (1) has a wavy structure in cross-section.

7. A biodegradable barrier for radiotherapy of pancreatic cancer according to claim 1, characterized in that: The biodegradable spacer (1) is located between the stomach (5), intestine (6) and pancreas (4) after implantation, and is used to provide an isolation distance of at least 10 mm in the pancreatic lesion (3) for stereotactic radiotherapy.

8. A method for implanting a biodegradable spacer for radiotherapy of pancreatic cancer according to any one of claims 1-7, characterized in that: Includes the following steps: Step 1: Flatten and roll the biodegradable spacer (1) capsule into a cylindrical shape; Step 2: Insert the rolled-up sac into the abdominal cavity (2) through the laparoscopic channel; Step 3: Deploy and secure the sac within the abdominal cavity; Step 4: Inject biodegradable hydrogel into the capsule through the injection port to fill it into the predetermined shape.

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