How to prepare an animal model of laryngeal paralysis?

  (1) The method of replication is to select experimental dogs, anesthetize them by intramuscular injection of ketamine hydrochloride at a dose of 30-50 mg/kg body weight. After the animal is under general anesthesia, fix it on its back and take a median incision in the neck, cut the skin, and cut the anterior band muscles along the neck. The midline is separated to expose the thyroid cartilage, cricoid cartilage and trachea. One side of the recurrent laryngeal nerve is found in the tracheoesophageal sulcus. After electrical stimulation is confirmed to be the recurrent laryngeal nerve, it is cut off 1cm, and both ends are ligated. Animal model of lateral throat paralysis. If an animal model of bilateral laryngeal palsy is required, the same method can be used to cut off the other recurrent laryngeal nerve.

  (2) Features of the model The feature of this model is that after cutting off one side of the recurrent laryngeal nerve and ligating the outer branch of the superior laryngeal nerve, the vocal cords on the surgical side are obviously fixed in the para-median position, and gradually atrophy with time, and the most obvious atrophy is at 16 weeks after surgery. ; But after a certain period of time, it no longer shrinks, and the other side of the vocal cord shows compensatory hypertrophy with the extension of the modeling time. Early after modeling, the model animals had hoarseness and poor breathing. The volume of the adductor muscle of the model animal was significantly smaller than the adductor muscle of the contralateral side. Electromyographic examination showed that the waveform of the adductor muscle of the model animal was different from that before the animal laryngeal paralysis. Larger; laryngeal adductor motor end plate (MEP) is significantly reduced, the longer the resection time, the less MEP, and its shape is extremely irregular. Histopathological observation under the microscope showed that the adductor muscle fibers of the laryngeal muscle appeared atrophy, the morphology and structure were blurred, and were replaced by connective tissue. The adductor muscle lesions gradually worsened as the model time became longer.

  (3) Comparative medicine. There are many reasons for human Laryngeal Paralysis in clinical practice, but surgical injury is the main reason, and thyroidectomy is one of the most common causes. Others such as tumor compression, inflammation and unexplained characteristics Primary paralysis of the larynx is also one of the causes of vocal cord paralysis. Clinically, cases of recurrent laryngeal nerve palsy caused by various reasons can cause vocalization and respiratory dysfunction in patients. In the model replicated by this method, when the animal’s recurrent laryngeal nerves are injured, especially when the bilateral recurrent laryngeal nerves are injured, the adduction and abduction function of the laryngeal muscles is restricted, causing the bilateral vocal cords to be located in the paramedian position, which easily leads to breathing Difficult, usually requires tracheotomy to restore respiratory function. This model has ideal research value in human vocal cord adduction and abduction function and recurrent laryngeal nerve injury repair.