| Part I: The safety and efficacy of subxiphoid thoracoscopic thymectomy:a propensity score matching analysisObjective: To evaluate the safety,feasibility and advantages of subxiphoid VATS thymectomy,and to further explore the oncological outcomes and long-term prognostic factors of VATS thymectomy in the treatment of early-stage thymoma.Methods: Using the propensity score matching(PSM)analysis,the clinical and perioperative data of patients(n = 397)who underwent subxiphoid VATS thymectomy(STT)or unilateral VATS thymectomy(UTT)for thymic tumor in our center from January2013 to January 2020 were retrospectively analyzed to confirm the advantages of subxiphoid VATS thymectomy.Kaplan-Meier method was used for survival analysis of patients(n = 134)with regular follow-up,the Cox proportional hazard model was used for uni-and multivariable analysis,so as to further explore the impact of the surgical methods on the long-term oncological outcome and the related factors affecting the prognosis of early-stage thymoma.The cumulative sum(CUSUM)curve was used to describe the learning curve of subxiphoid VATS thymectomy.Results: A total of 171 pairs of patients were successfully matched after PSM.In the matched pairs,there was no significant difference in the incidence of postoperative complications between STT and UTT.However,the STT group had shorter thoracic drainage time(2.31 ± 1.22 d vs.3.47 ± 1.53 d,P = 0.027)and shorter operation time(105.32 ± 32.85 min vs.129.49 ± 37.18 min,P = 0.031),postoperative hospital stays(3.52± 1.60 d vs.5.01 ± 1.98 d,P = 0.032)and lower hospitalization costs(3.31 ± 1.08ten-thousand-yuan vs.4.37 ± 1.31,ten-thousand-yuan,P = 0.045).Compared with UTT group,the visual analogue pain(VAS)score in the STT group was lower on postoperative day 1(POD1)(4.50 ± 1.03 vs.6.31 ± 1.25),POD3(3.01 ± 0.61 vs.5.24 ± 0.89),POD7(1.38 ± 0.32 vs.2.99 ± 0.57)and PDO14(0.77 ± 0.29 VS.1.31 ± 0.38),the difference was statistically significant(P < 0.05).CUSUM curve was used to describe the learning curve of STT.The CUSUM curve showed that fitting curve crossed the top at the 18 th case.The operative time and intraoperative blood loss in learning period were more than those in skilled period.The mean follow-up time of this study was 57.03 ± 24.8 months,with a median follow-up time of 58.5 months.The 5-year overall survival(OS)and 5-year progression-free survival(PFS)of 128 matched patients with early thymoma were 97%and 95%,respectively.Kaplan-Meier survival analysis and uni-and multivariable Cox regression analysis showed that age(≤50-years vs.>50-years,HR = 5.072,95%CI:1.405-16.209,P = 0.018)and comorbidity(No VS.Yes,HR = 4.183,95%CI:1.433-11.681,P = 0.035)and WHO histological type(≤B1 vs.≥B2,HR = 3.212,95%CI: 1.219-6.794,P = 0.024)may be associated with the long-term prognosis after surgical resection of early thymoma.Conclusions: This study confirms that STT was a safe and feasible procedure for the early-stage thymoma,with significant perioperative advantages: shorter chest drainage and postoperative hospital stay,lower hospitalization costs,and less postoperative pain.The CUSUM learning curve for STT was also plotted in this study,and the results showed that the surgeons need 18 cases of STT to cross the learning curve approximately.In this study,we compared the oncological outcomes of STT and UTT for early-stage thymomas and found that subxiphoid and unilateral VATS thymectomy both had the same good oncological outcomes as open surgery.The results also showed that age(> 50-years),comorbidities,and a more aggressive WHO thymoma histological type(B2/B3/C)were associated with poorer OS and PFS.Part II: The prognostic factors of subxiphoid versus unilateral thoracoscopic thymectomy for myasthenia gravisObjective: To evaluate the safety and feasibility of VATS thymectomy via subxiphoid and unilateral thoracic approach in the treatment of myasthenia gravis(MG),and to to identify the factors affecting MG prognosis.Methods: From January 2013 to December 2019,a total of 137 consecutive MG patients received subxiphoid VATS thymectomy(STT,n = 65)or conventional unilateral VATS thymectomy(UTT,n = 72).Complete stable remission(CSR)was set as the primary end point and general clinical remission(CSR + PR + MM + I)was set as the secondary end point in this study.Kaplan-Meier method was used to draw the cumulative CSR curve,and uni-and multivariable Cox regression models were used to determine the factors related to postoperative CSR.Results: The patients receiving STT had significantly shorter drainage duration(2.20 ± 1.13 d VS.3.51 ± 1.42 d,P = 0.006)and postoperative hospital stay(3.41 ± 1.70 d VS.5.32 ± 2.94 d,P = 0.002)and lower hospitalization expenses(5.21 ± 1.03 thousand USD VS.7.60 ± 1.91 thousand USD,P = 0.004).The average follow-up of the 134 patients was 54.3 ± 24.18 months,with a CSR rate of 30.6%,overall effective rate of 87.3%,and 5-year cumulative probability of CSR of 22.3%.Through uni-and multivariable analysis,shorter symptom duration(< 1 year,HR = 3.908,95%CI: 1.583-9.681,P = 0.019)and Myasthenia Gravis Foundation of America(MGFA)(class I,HR = 3.271,95%CI:1.295-6.84,P = 0.035)were independent predictors for CSR in MG patients receiving thymectomy.Conclusions: The present study showed that STT was a safe and feasible technique for MG,with a potentially faster postoperative recovery and equivalent remission rate.Despite the inherent limitations of the single-center retrospective study,it could still suggest that MG patients with shorter symptom duration(< 1 year)and MGFA class I may have a higher remission rate.Part III: The safety and feasibility of non-intubated subxiphoid thoracoscopic thymectomy: a propensity score matching analysisObjective: To evaluate the safety,feasibility and advantages of non-intubated subxiphoid VATS thymectomy(NI-STT).Methods: Using the PSM analysis,a retrospective analysis of patients(n = 71)who underwent subxiphoid VATS thymectomy under non-intubation or single-lumen endotracheal intubation anesthesia for thymic tumor in our hospital from June 2019 to June 2021 was performed to confirm the feasibility,safety,and advantages of NI-STT.Results: A total of 32 pairs of patients were successfully matched after PSM.In the matched cohort,there was no statistical difference between the two groups in intraoperative anesthesia induction time,lowest Sp O2,highest Et CO2,operative time and blood loss.The incidence of postoperative sore throat and irritating cough in the endotracheal intubation group was significantly higher than that in NI-STT group,and the difference was statistically significant(P < 0.05).Cough scores in the NI-STT group were significantly lower than in the endotracheal intubation group on POD1(0.06 ± 0.35 vs.0.50 ± 1.08,P = 0.042)and POD3(0.03 ± 0.18 vs.0.281 ± 0.73,P = 0.031).Interleukin-6(IL-6)levels in NI-STT group were significantly lower than those in the endotracheal intubation group on POD1(7.26 ± 1.44 pg/m L vs.8.85 ± 1.11 pg/m L,P = 0.013)and POD3(6.70 ± 1.26 pg/m L vs.8.57 ± 0.74 pg/m L,P = 0.001).C-reactive protein(CRP)in NI-STT group was significantly lower than those in the endotracheal intubation group on POD1(8.18 ± 1.21 mg/L vs.9.78 ± 1.03 mg/L,P = 0.005)and POD3(7.46 ± 1.10 mg/L vs.8.75 ± 0.86 mg/L,P = 0.008).Conclusions: Compared with the traditional endotracheal intubation anesthesia technique,the NI-STT was a safe and feasible anesthetic management and surgical approach for the treatment of thymoma,without any increase in operation time and postoperative complications.And at the same time,it had a lower incidence of sore throat and irritating cough,and a lower level of inflammatory factors,which confirmed that NI-STT had obvious perioperative advantages and was of great significance to ERAS. |
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