The Learning Curve In Endoscopic Pituitary Surgery

OBJECTIVE:In this study,we analyzed the operation time and effect of patients undergoing endoscopic transsphenoidal surgery for pituitary adenomas.to explore the relationship between the operation time and the effect of endoscopic transsphenoidal pituitary tumor surgery in different stages,and through the relationship to demonstrate whether the learning curve exists,and what kind of form it will be if it exists.We hope to provide a theoretical basis for improving the efficiency of endoscopic learning by studying the learning curve of endoscopic transsphenoidal pituitary tumor surgery.METHODS:From 2018 to 2019,54 patients who underwent neuroendoscopic transsphenoidal surgery for pituitary adenomas in the Department of Neurosurgery of Kunming Medical University were analyzed retrospectively.The screening conditions were patients with pituitary adenomas whose age was between 18 and 75 years old,had no history of surgery for nasal and pituitary adenomas,whose volume of pituitary adenomas was 10-50mm and whose Knosp classification was less than grade 3(to avoid excessive deviation between surgical data as much as possible by limiting tumor size and invasion).The patients were arranged in order according to the operation date,and then were divided into pre-operation group and late operation group averagely.The demographic data,tumor type(size,invasiveness,classification),operation time,complications(cerebrospinal fluid leakage,diabetes insipidus and operation-related epistaxis)and gross tumor resection rate(that is,the ratio of gross total resection of tumors to the total number of patients in each group)were analyzed.Then 6 patients were divided into 9 groups according to the order of operation period,and the average value was drawn to observe the relationship between operation time and operation date.We use the operation time to reflect the efficiency of the operator and his team,and the incidence of complications and the tumor resection rate during the operation to reflect the effect of the operation(indirect response to the maturity of the operator's skills).And included in the demographic data and tumor types to see whether it has a certain impact on the time of operation.By studying the correlation between the operation time of each operation period and the incidence of complications and tumor resection rate,to judge whether the above research projects will develop regularly with the passage of time.(Knosp grading method is shown in Table 1)RESULTS:There was no significant difference in age,sex,tumor size,invasiveness and classification among the groups involved in the study(P>0.05).The average operation time(SD)scores of early operation group and late operation group were 151.48min(34.28)and 75.74min(9.62),which were statistically significant.In the nine groups,there was a "steep" trend between group C and group F,and it was the most significant in group Dmure.After group F,it entered a relatively flat period.In terms of complications,cerebrospinal fluid leakage existed in all groups,including 5 cases in the early group and 4 cases in the late group.The number of postoperative diabetes insipidus was 4 cases in the early stage and 1 case in the later stage.The data of cerebrospinal fluid leakage and postoperative diabetes insipidus among the groups were not statistically significant.The above symptoms of cerebrospinal fluid leakage and diabetes insipidus were cured and did not recur before discharge.Epistaxis was statistically significant(Please 0.038).There were 2 patients with epistaxis during and after operation,but no epistaxis occurred in the later stage.In terms of gross total resection rate,there was no significant difference in gross total resection rate between the two groups(Purge 0.362).Among them,the gross total resection rate of tumor in the early operation group was 66.7%,and that in the later operation group was 77.8%.Multiple Logistic regression analysis showed that the gross resection rate was significantly correlated with the degree of tumor invasion(P<0.001),but not with tumor size(P>0.05).The effect of tumor size and invasion degree on gross tumor resection rate was significantly correlated with tumor invasion degree(P<0.05),but not with tumor size(P<0.05).CONCLUSION:Through the results of this study,it was found that there was a"steep" learning curve in endoscopic transsphenoidal surgery for pituitary adenomas,and the learning efficiency was the highest in 27(±3)operations.After about 36 operations,they entered the opposite platform and reached the end of the learning curve.In terms of the incidence of complications,the incidence of epistaxis decreased significantly after experiencing the learning curve.Although cerebrospinal fluid leakage and diabetes insipidus were not statistically significant,the incidence of cerebrospinal fluid leakage and diabetes insipidus decreased gradually with the increase of learning time.Therefore,this is not enough to show that the enrichment of learning experience will not reduce the incidence of these two complications.In terms of gross total resection rate of tumor,the gross total resection rate of tumor in the late operation group was better than that in the previous stage,but it was not statistically significant,which may be related to the insufficient sample size and the rich experience in the treatment of pituitary adenomas.In view of the results of our group's study of the learning curve,we will analyze and discuss its impact on safety,effectiveness and subspecialist necessity.