Cryoanalgesia Under Muscle-sparing Thoracotomy

In the 1970's, Foreign thoracic surgeon reduced the postoperative pain through cryoanalgsia with liguid nitrogen, This technique had been popular for a time, But the only blocking intercostals nerves could not control the pain of mass muscle of back which was divided under standard lateral thoracotomy, And sensory function of thoracic wall recovered slowly, This physical analgesia method was spurned. A better analgesia of thoracotomy could not only improve the quality of life ,But reduce the complications caused by pain. So surgeons pay more and more attention on the analgesia of thoracotomy. In this experiment , We combine cryoanalgesia with muscle-sparing thoracotomy, And apply this method to the operation on lung and mediastinum. We enhance the effect of analgesia and postoperative pulmonary function through this method. The first section : Animal experimentThe purpose of this research is to predict the proper range of temperature within which the nerve freezed can regenerate completely, Through establing the animal model of regeneration of peripheral nerve after freezing in different temperature .We select different temperature within this range and freeze the sciatic nerve of rats, Through the methods of pathological diagnosis, gait analysis, measuring the latent of somatosensory evoked potential, We assess the situation of nerve necrosis, regeneration and the recovery of motor and sensory function.The result of this research is below:1 Establing the experimental model of rat.2 Nerval basement membrane can be kept integrity after freezed between -60C and -100C, We speculate that nerve can regenerate completely in this temperature range which the next experiment based on.3 We freeze the rat sciatic nerve in the -60C and -100C individually, And acquire nerval tissue in different parts periodically, The results of pathology show that the injure of nerve in -60C group is lighter than -100C group, And the recovery of nerve is faster.4 The result of SFI show that the functional recovery of hindlimb in -60C group is faster, And approach the common degree in the end.5 The records of SSEP show that the sensory functional have been recovering 30 days after nerve freezed, But the recovery of sensory function lags behind the recovery of nerval anatomy.Conclusion : The myelin sheath of peripheral nerval fiber would be ruptured with the nerval besement membrane integrity in the day freezed between-60C and -100C. In this Range, The higher temperature is ,The faster nerve regenerate and function recover.The second part: Clinic experimentThe purpose of this research is evaluating the clinic significance of MST-INC through comparing the postoperative effect of analgesia ,The function of pulmonary and body between the methods of MST-INC and the PCIA popularly used method .The result of this research is below:1 Effect of analgesia : The VAS of MSC-INC group is significantly lower than PCIA group.2 Pulmonary function: The MSC-INC can not improve the pulmonary function significantly in postoperative 1th week, But the pulmonary function of it is better than PCIA group in the early postoperative time.3 Physical function: Shoulder girdle strength is stronger, And less complication occurred in MST-INC group than the group of PCIA.Conclusion: All the treated group can gain a satisfactory effect of analgesia, But the MSC-INC group can gain a better effect, And only the MSC-INC group can ameliorates the pulmonary function in the early postoperative time and facilitate the body recovery.