CN112908135B

CN112908135B - Adjustable experimental tool for establishing rat nerve injury model

Info

Publication number: CN112908135B
Application number: CN202110144944.6A
Authority: CN
Inventors: 叶招明; 徐恺成; 黄东骅; 柳萌; 邵佳琦; 滕王锶源
Original assignee: Zhejiang University ZJU
Current assignee: Zhejiang University ZJU
Priority date: 2021-02-02
Filing date: 2021-02-02
Publication date: 2023-03-03
Anticipated expiration: 2041-02-02
Also published as: CN112908135A

Abstract

The invention discloses an adjustable experimental tool for establishing a rat nerve injury model, which comprises two scissors which are mirror images of each other, wherein the two scissors are connected through three connecting shafts, one connecting shaft is arranged at the crossed part of the scissors, and the other two connecting shafts are respectively arranged at two handle parts of the scissors; springs are arranged on the three connecting shafts, the springs are positioned between the two scissors, and the distance between the two scissors is changed by adjusting the compression length of the springs; the contact areas of the spring, the scissors and the connecting shaft are smooth; in the two scissors, the scissor blades positioned on the inner sides are both designed to be in a concave shape below the pointed end, and the inner sides of the concave scissor blades below the pointed end are provided with hooks. The novel experimental tool can adjust the width of the scissors, cut off nerves with corresponding lengths at one time according to different experimental requirements, and simultaneously can stably and safely take out the nerves by utilizing the hook, thereby facilitating further research of subsequent tissue section making and the like.

Description

Adjustable experimental tool for establishing rat nerve injury model

Technical Field

The invention relates to an animal model experimental instrument, in particular to an adjustable experimental tool for establishing a rat nerve injury model.

Background

Peripheral nerves refer to all nerves except the brain and spinal cord, including ganglia, nerve trunks, plexuses and nerve terminal devices, and can be classified into afferent nerves and efferent nerves according to the direction of the transmitted nerve impulses. The afferent nerves transmit nerve impulses to the central nervous system via the periphery to produce sensation, also known as sensory nerve; efferent nerves transmit nerve impulses from the center to the periphery to produce movement, also known as motor nerves.

Peripheral nerve injury is a clinical condition in which the trunk or branches of the peripheral nerve are accidentally injured by external direct or indirect trauma, resulting in dysfunction of the movement, sensation and autonomic nerves of the trunk and limbs [1]. The pathophysiological mechanism of tissues such as bones, muscles and the like after nerve injury is not clear at present, the treatment effect of the nerve injury is not ideal in clinic, and the research on the repair of peripheral nerve injury is still a current hotspot and difficulty.

Nerve injury models commonly used in animal experiments, such as sciatic nerve injury models, tibial nerve injury models, inferior alveolar nerve injury models and the like, all relate to an important link, namely, a section of target nerve is cut and taken out. Taking the model of the damage of the inferior alveolar nerve of the rat as an example, the general process is as follows: an operation incision which is parallel to the lower jaw edge and is about 1.5cm long is made along about 5mm below the lower jaw edge of a rat, after the muscles are separated obtusely by hemostatic forceps and reach the inner bone surface of the lower jaw, the muscles are separated obtusely along the inner side of a mandible ascending branch and continue to be separated obtusely to a mandibular opening and reach a lower alveolar neurovascular bundle, then bent forceps are used for inserting and clamping the lower alveolar nerve, and the nerve is cut off twice by tissue cutting. There are often problems in this process: 1. the peripheral structure has rich blood supply, easy bleeding in the operation process, deep lower alveolar nerve position, unclear operative field and poor nerve exposure; 2. the space available for operation in the lower jaw area of the rat is limited, and the operation of cutting off the nerve by using tissues after the nerve is clamped by the forceps is limited, so that the difficulty is high; 3. after a nerve at one end is cut off by using the tissue scissors, the nerve shrinks, so that the length of the nerve is changed, whether the length of the cut nerve reaches the expected length of the cut nerve in an experiment is difficult to evaluate, if the length of the cut nerve is insufficient, the nerve has the possibility of regeneration and reconnection, and the experimental result is seriously interfered; 4. after the nerves are cut off by the tissue scissors twice, a small cut of the cut nerves can be hidden in the tissue gap and can not be taken out, so that an operator can hardly judge whether the nerve cutting is really finished or not, and the possibility of repairing and reconnecting the severed nerve end is increased by the nerves left in the tissue gap.

The nerve injury animal model commonly used at present is difficult to guarantee to accurately cut off the nerve of required length in the operation process, and the human subjective operation influence factor is big, and simultaneously, the length of the nerve to be cut off is different under different experimental animals, different positions and different experimental requirements. At present, in an animal experiment needing to construct a nerve injury model, two ends of a nerve need to be cut off successively by an existing tissue cutter twice, after one end of the nerve is cut off, the length of the nerve changes due to contraction of the nerve, the length of the nerve needed cannot be guaranteed when the other end of the nerve is cut off, the nerve at a deeper position is often difficult to completely take out after the nerve is cut off, and the technical requirement that the nerve cannot be self-healed can not be met in the experiment. In the prior art, an experimental tool applied to a rat sciatic nerve injury model can cut off a section of nerve at one time, but the technology is limited to research on sciatic nerve injury, the length of the cut nerve is fixed to be 2mm, a hook of the experimental tool hooks the nerve and is easy to hook muscles, and the nerve is easy to slip off from the hook in the taking-out process.

Disclosure of Invention

In order to overcome the defects, the invention provides a novel experimental tool which can cut two ends of a required nerve at the same time to avoid the problem of nerve retraction and completely take out the cut nerve for further experimental requirements such as subsequent tissue section preparation and the like; meanwhile, the distance between the scissors can be adjusted, so that the length of the cut nerves is changed, and the method is conveniently applied to nerve injury modeling of different parts of experimental animals.

The technical scheme adopted by the invention for solving the technical problems is as follows:

an adjustable experimental tool for establishing a rat nerve injury model comprises two scissors which are mirror-symmetric to each other and are connected through three connecting shafts, wherein one connecting shaft is arranged at the crossed part of the scissors, and the other two connecting shafts are respectively arranged at two handle parts of the scissors; springs are arranged on the three connecting shaft connecting shafts, the springs are positioned between the two scissors, and the distance between the two scissors is changed by adjusting the compression degree of the springs; the contact areas of the spring, the scissors and the connecting shaft are smooth; in the two scissors, the scissors blades positioned at the inner sides are designed to be concave under the pointed ends, so that the scissors can conveniently extend into the lower parts of nerves, and the nerves are fully exposed; the inner side of the concave scissor blade under the sharp head is provided with a hook for hooking the nerve so as to take out the nerve.

In the above technical solution, further, the connecting shaft sequentially includes a scale section, a threaded section and a spring section; the screw thread section is provided with a screw cap, the spring is arranged on the spring section, and the compression length of the spring is changed by rotating the screw cap so as to change the distance between the two scissors. By changing the length of each section of the connecting shaft and the length of the internal thread of the nut, various experimental requirements for establishing a rat nerve injury model can be met.

Furthermore, the maximum displacement of the nut on the connecting shaft is equal to the length of the scale segment.

Further, the lower edge of the hook extends from the side surface of the shear blade and is inwards angled, the bottom of the upper edge of the hook is flush with the upper edge of the cutting edge of the shear blade, and the upper edge of the hook is parallel to the cutting edge of the shear blade on which the hook is arranged.

Furthermore, the angle formed between the lower edge of the hook and the scissor blade is 15-30 °

In the invention: the two scissors are connected through a specially designed shaft, and the scissors have the function of cutting off a section of nerve at one time; the connecting shaft comprises a scale section, a threaded section and a spring section, the threaded section is provided with a nut, the distance between the two scissors is adjusted by rotating the nut to adjust the compression length of the spring (the spring is always in a compression state, so that the two scissors are parallel to each other and keep stable), the length of a cut nerve can be changed according to different experimental requirements, and an operator can observe scales on the connecting shaft to determine the current distance between the two scissors; two inboard scissors pieces design for the prong concave surface is convex, probes into from neural below during convenient operation, makes neural fully expose, catches on neural with two hooks of scissors piece inboard simultaneously, and the neural drop when preventing to withdraw from the scissors. The lower edge of the hook is angled inwards from the blade wall to form a flat edge, the bottom of the upper edge of the hook is flat with the upper edge of the blade of the shear blade, the nerve is prevented from being dragged to influence the actual length due to the inconsistent height, and the upper edge of the hook is parallel to the blade of the shear blade where the upper edge of the hook is located, so that the nerve can be hooked conveniently and stably.

The beneficial effects of the invention are:

the novel experimental tool can adjust the width of the scissors, cut off nerves with corresponding lengths at one time according to different experimental requirements, and simultaneously can stably and safely take out the nerves by utilizing the hook, thereby facilitating further researches such as subsequent tissue section preparation and the like.

Drawings

FIG. 1 is a schematic backside view of a test device;

FIG. 2 is a schematic front view of the experimental device;

FIG. 3 is a schematic illustration of a connecting shaft;

FIG. 4 is a schematic view of a hook hooking a nerve;

the device comprises a connecting shaft A1, a connecting shaft B2, a connecting shaft C3, a hook 4, a scale section 5, a thread section 6, a spring section 7 and a nut 8.

Detailed Description

The invention is further described with reference to the following figures and specific embodiments.

Fig. 1 and 2 show an adjustable experimental tool for establishing a rat nerve injury model according to the present invention, the experimental tool includes two scissors which are mirror images of each other and are connected by three connecting shafts, wherein the connecting shaft A1 is arranged at the crossing position of the scissors, and the connecting shaft B2 and the connecting shaft C3 are respectively arranged at the two handle positions of the scissors; springs are arranged on the three connecting shafts, are positioned between the two scissors and change the distance between the two scissors by adjusting the compression length of the springs; the contact areas of the spring, the scissors and the connecting shaft are smooth; in the two scissors, the scissor blades positioned at the inner sides are both designed to be concave under the pointed head, and the inner sides of the concave scissor blades under the pointed head are provided with hooks 4.

Referring to fig. 3, the three connecting shafts A1, B2 and C3 include a scale section 5, a threaded section 6 and a spring section 7, the threaded section 6 is provided with a nut 8, the spring is provided on the spring section 7, and the distance (e.g. 5-10 mm) between the two scissors is changed by rotating the nut 8 to compress the spring. The maximum displacement of the nut on the connecting shaft is equal to the length of the scale section 5. The upper end of the nut 8 can be rotated from the uppermost graduation mark to the uppermost end of the threaded section 6, thereby changing the length of the nerve cut. The lower edge of the hook 4 extends from the side surface of the shear blade and is inwards angled (the angle can be 15-30 degrees), and the bottom of the upper edge of the hook is level with the upper edge of the cutting edge of the shear blade, so that the nerve is prevented from being pulled to influence the actual length due to inconsistent height; the upper edge of the hook 4 is parallel to the blade of the scissor blade, which is convenient for stably hooking nerves.

As shown in fig. 4, the hooks can hook the nerves, and the two hooks 4 can fix the nerves, thereby avoiding the nerves from self-anastomotic repair.

Example 1

Taking the construction of a mandibular nerve injury model of SD rat as an example: 2% sodium pentobarbital 0.2ml/100g, anaesthetized by intraperitoneal injection, fixed SD rat, and sterilized by topical iodophor. An operation incision parallel to the lower jaw edge of the rat and about 1.5cm long is made along about 5mm below the lower jaw edge of the rat, after the muscles are separated bluntly by the hemostatic forceps reach the inner bone surface of the mandible, the muscles are separated bluntly along the inner side of the mandible ascending branch until reaching the mandibular opening, and the inferior alveolar neurovascular bundle is white, about 1mm thick and tough. The length of a nerve to be cut off is determined according to experimental requirements, and three nuts 8 on the rotary connecting shafts A1, B2 and C3 are adjusted to corresponding scales, so that the distance between the two scissors is consistent with the length of the nerve to be cut off; the scissors blade with the concave shape under the pointed end penetrates through the lower part of the nerve, the nerve is hooked by the hooks 4 on the two scissors, then the nerve is cut off, the nerve is taken out under the closed state of the scissors, the nerve is prevented from being anastomosed and repaired by self, and the artery and vein of the lower alveolar are protected. The operation area is repeatedly washed by normal saline, and layered suture is carried out after sufficient hemostasis.

Claims

1. An adjustable experimental tool for establishing a rat nerve injury model is characterized by comprising two scissors which are mirror images of each other, wherein the two scissors are connected through three connecting shafts, one connecting shaft is arranged at the crossed part of the scissors, and the other two connecting shafts are respectively arranged at two handle parts of the scissors; springs are arranged on the three connecting shafts, the springs are positioned between the two scissors, and the distance between the two scissors is changed by adjusting the compression length of the springs; the contact areas of the spring, the scissors and the connecting shaft are smooth; in the two scissors, the scissor blades positioned at the inner sides are both designed to be in a downward concave shape with pointed ends, and the inner sides of the downward concave scissor blades with the pointed ends are provided with hooks;

the lower edge of the hook extends out from the side surface of the shear blade and forms an inward angle, the bottom of the upper edge of the hook is level with the upper edge of the cutting edge of the shear blade, and the upper edge of the hook is parallel to the cutting edge of the shear blade; an angle formed between the lower edge of the hook and the shear blade is 15-30 degrees;

the connecting shaft sequentially comprises a scale section, a threaded section and a spring section; the screw thread section is provided with a screw cap, the spring is arranged on the spring section, and the compression length of the spring is changed by rotating the screw cap so as to change the distance between the two scissors.

2. The adjustable experimental kit for establishing a rat nerve injury model according to claim 1, wherein the maximum displacement of the nut on the connecting shaft is equal to the length of the scale segment.