AIM:To investigate the 10-year results of treating low rectal cancer by a single surgeon in one institution.METHODS:From Oct 1998 to Feb 2009,we prospectively followed a total of 62 patients with cT2-4 low rectal canc...AIM:To investigate the 10-year results of treating low rectal cancer by a single surgeon in one institution.METHODS:From Oct 1998 to Feb 2009,we prospectively followed a total of 62 patients with cT2-4 low rectal cancer with lower tumor margins measuring at 3 to 6 cm above the anal verge.All patients received neoadjuvant chemoradiation(CRT) for 6 wk.Among them,85% of the patients received 225 mg/m2/d 5-fluorouracil using a portable infusion pump.The whole pelvis received a total dose of 45 Gy of irradiation in 25 fractions over 5 wk.The interval from CRT completion to surgical intervention was planned to be approximately 6-8 wk.Total mesorectal excision(TME) and routine defunctioning stoma construction were performed by one surgeon.The distal resection margin,circumferential resection margin,tumor regression grade(TRG) and other parameters were recorded.We used TRG to evaluate the tumor response after neoadjuvant CRT.We evaluated anal function outcomes using the Memorial Sloan-Kettering Cancer Center anal function scores after closure of the defunctioning stoma.RESULTS:The median distance from the lower margin of rectal cancer to the anal verge was 5 cm:6 cm in 9 patients,5 cm in 32 patients,4 cm in 10 patients,and 3 cm in 11 patients.Before receiving neoadjuvant CRT,45 patients(72.6%) had a cT3-4 tumor,and 21(33.9%) patients had a cN1-2 lymph node status.After CRT,30 patients(48.4%) had a greater than 50% clinical reduction in tumor size.The final pathology reports revealed that 33 patients(53.2%) had a ypT3-4 tumor and 12(19.4%) patients had ypN1-2 lymph node involvement.All patients completed the entire course of neoadjuvant CRT.Most patients developed only Grade 1-2 toxicities during CRT.Thirteen patients(21%) achieved a pathologic complete response.Few post-operative complications occurred.Nearly 90% of the defunctioning stomas were closed within 6 mo.The local recurrence rate was 3.2%.Pathologic lymph node involvement was the only prognostic factor predicting disease recurrence(36.5% vs 76.5%,P = 0.006).Nearly 90% of patients recovered sphincter function within 2 year after closure of the defunctioning stoma.CONCLUSION:Neoadjuvant CRT followed by TME,combined with routine defunctioning stoma construction and high-volume surgeon experience,can provide excellent surgical quality and good local disease control.展开更多
In recent years,defunct satellites mitigation in the geostationary orbit(GEO) has become a hot issue in the space field.How to transfer defunct geostationary satellites to the graveyard orbit safely,economically and e...In recent years,defunct satellites mitigation in the geostationary orbit(GEO) has become a hot issue in the space field.How to transfer defunct geostationary satellites to the graveyard orbit safely,economically and efficiently presents new challenges to spacecraft dynamics and control.This paper conducts an in-depth investigation on tether-tugging de-orbit issues of defunct geostationary satellites.Firstly,a four-phase tether-tugging de-orbit scheme including acceleration,equilibrium,rotation and return is proposed.This scheme takes into consideration how to avoid the risks of tether ripping,tug-target collision,and tether twist,and how to achieve the mission objective of fuel saving.Secondly,the dynamics model of the tether combination system is established based on Lagrange equation,and the four phases of tether-tugging de-orbit scheme are simulated respectively.Simulation results indicate that the scheme is theoretically feasible and satisfies the design objectives of safety,economy and efficiency,providing a technical approach for engineering application.展开更多
Background::Defunctioning stoma is widely used to reduce anastomotic complications in rectal cancer surgery.However,the complications of stoma and stoma reversal surgery should not be underestimated.Furthermore,in som...Background::Defunctioning stoma is widely used to reduce anastomotic complications in rectal cancer surgery.However,the complications of stoma and stoma reversal surgery should not be underestimated.Furthermore,in some patients,stoma reversal failed.Here,we investigated the complications of defunctioning stoma surgery and subsequent reversal surgery and identify risk factors associated with the failure of getting stoma reversed.Methods::In total,154 patients who simultaneously underwent low anterior resection and defunctioning stoma were reviewed.Patients were divided into two groups according to whether their stoma got reversed or not.The reasons that patients received defunctioning stoma and experienced stoma-related complications and the risk factors for failing to get stoma reversed were analysed.Results::The mean follow-up time was 47.54(range 4.0-164.0)months.During follow-up,19.5%of the patients suffered stoma-related long-term complications.Only 79(51.3%)patients had their stomas reversed.The morbidity of complications after reversal surgery was 45.6%,and these mainly consisted of incision-related complications.Multivariate analyses showed that pre-treatment comorbidity(HR=3.17,95%CI 1.27-7.96,P=0.014),postoperative TNM stage(HR=2.55,95%CI 1.05-6.18,P=0.038),neoadjuvant therapy(HR=2.75,95%CI 1.07-7.05,P=0.036),anastomosis-related complications(HR=4.52,95%CI 1.81-11.29,P=0.001),and disease recurrence(HR=24.83,95%CI 2.90-213.06,P=0.003)were significant independent risk factors for a defunctioning stoma to be permanent.Conclusions::Defunctioning stoma is an effective method to reduce symptomatic anastomotic leakage,but the stoma itself and its reversal procedure are associated with high morbidity of complications,and many defunctioning stomas eventually become permanent.Therefore,surgeons should carefully assess preoperatively and perform defunctioning stomas in very high risk patients.In addition,doctors should perform stoma reversal surgery more actively to prevent temporary stomas from becoming permanent.展开更多
Objective Anastomotic leakage(AL)is one of the serious complications after anterior resection for rectal cancer.Defunctioning stoma(DS)is one of the most widely used approaches to prevent it;however,the effect of DS o...Objective Anastomotic leakage(AL)is one of the serious complications after anterior resection for rectal cancer.Defunctioning stoma(DS)is one of the most widely used approaches to prevent it;however,the effect of DS on the occurrence of AL remains controversial.This study aimed to investigate risk factors of AL and assess the effect of DS after anterior resection for rectal cancer patients.Methods A retrospective analysis was conducted for the data of 1840 patients who underwent anterior resection for rectal cancer from January 2014 to December 2019.Results The results showed the overall AL incidence was 7.5%.Multivariate analyses revealed that males[odds ratio(OR)1.562]and T3–T4 stage(OR 1.729)were independent risk factors for all patients.After propensity score matching analysis,the AL incidence was 14.1%in the group with no DS and 6.4%in the DS group(P<0.001).The clinical AL(grade B+grade C)incidence was 12.4%in no DS group and 4.6%in the DS group(P<0.001).Conclusion The study suggested that males and T3–T4 stage were independent risk factors of AL.In addition,DS could reduce the rate of symptomatic AL.展开更多
文摘AIM:To investigate the 10-year results of treating low rectal cancer by a single surgeon in one institution.METHODS:From Oct 1998 to Feb 2009,we prospectively followed a total of 62 patients with cT2-4 low rectal cancer with lower tumor margins measuring at 3 to 6 cm above the anal verge.All patients received neoadjuvant chemoradiation(CRT) for 6 wk.Among them,85% of the patients received 225 mg/m2/d 5-fluorouracil using a portable infusion pump.The whole pelvis received a total dose of 45 Gy of irradiation in 25 fractions over 5 wk.The interval from CRT completion to surgical intervention was planned to be approximately 6-8 wk.Total mesorectal excision(TME) and routine defunctioning stoma construction were performed by one surgeon.The distal resection margin,circumferential resection margin,tumor regression grade(TRG) and other parameters were recorded.We used TRG to evaluate the tumor response after neoadjuvant CRT.We evaluated anal function outcomes using the Memorial Sloan-Kettering Cancer Center anal function scores after closure of the defunctioning stoma.RESULTS:The median distance from the lower margin of rectal cancer to the anal verge was 5 cm:6 cm in 9 patients,5 cm in 32 patients,4 cm in 10 patients,and 3 cm in 11 patients.Before receiving neoadjuvant CRT,45 patients(72.6%) had a cT3-4 tumor,and 21(33.9%) patients had a cN1-2 lymph node status.After CRT,30 patients(48.4%) had a greater than 50% clinical reduction in tumor size.The final pathology reports revealed that 33 patients(53.2%) had a ypT3-4 tumor and 12(19.4%) patients had ypN1-2 lymph node involvement.All patients completed the entire course of neoadjuvant CRT.Most patients developed only Grade 1-2 toxicities during CRT.Thirteen patients(21%) achieved a pathologic complete response.Few post-operative complications occurred.Nearly 90% of the defunctioning stomas were closed within 6 mo.The local recurrence rate was 3.2%.Pathologic lymph node involvement was the only prognostic factor predicting disease recurrence(36.5% vs 76.5%,P = 0.006).Nearly 90% of patients recovered sphincter function within 2 year after closure of the defunctioning stoma.CONCLUSION:Neoadjuvant CRT followed by TME,combined with routine defunctioning stoma construction and high-volume surgeon experience,can provide excellent surgical quality and good local disease control.
基金supported by the National Hi-Tech Research and Development Program of China ("863" Project) (Grant No. 2011AA7044026)
文摘In recent years,defunct satellites mitigation in the geostationary orbit(GEO) has become a hot issue in the space field.How to transfer defunct geostationary satellites to the graveyard orbit safely,economically and efficiently presents new challenges to spacecraft dynamics and control.This paper conducts an in-depth investigation on tether-tugging de-orbit issues of defunct geostationary satellites.Firstly,a four-phase tether-tugging de-orbit scheme including acceleration,equilibrium,rotation and return is proposed.This scheme takes into consideration how to avoid the risks of tether ripping,tug-target collision,and tether twist,and how to achieve the mission objective of fuel saving.Secondly,the dynamics model of the tether combination system is established based on Lagrange equation,and the four phases of tether-tugging de-orbit scheme are simulated respectively.Simulation results indicate that the scheme is theoretically feasible and satisfies the design objectives of safety,economy and efficiency,providing a technical approach for engineering application.
基金This work was supported by a grant from the Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences(CIFMS,No.2016-I2M-1-007).
文摘Background::Defunctioning stoma is widely used to reduce anastomotic complications in rectal cancer surgery.However,the complications of stoma and stoma reversal surgery should not be underestimated.Furthermore,in some patients,stoma reversal failed.Here,we investigated the complications of defunctioning stoma surgery and subsequent reversal surgery and identify risk factors associated with the failure of getting stoma reversed.Methods::In total,154 patients who simultaneously underwent low anterior resection and defunctioning stoma were reviewed.Patients were divided into two groups according to whether their stoma got reversed or not.The reasons that patients received defunctioning stoma and experienced stoma-related complications and the risk factors for failing to get stoma reversed were analysed.Results::The mean follow-up time was 47.54(range 4.0-164.0)months.During follow-up,19.5%of the patients suffered stoma-related long-term complications.Only 79(51.3%)patients had their stomas reversed.The morbidity of complications after reversal surgery was 45.6%,and these mainly consisted of incision-related complications.Multivariate analyses showed that pre-treatment comorbidity(HR=3.17,95%CI 1.27-7.96,P=0.014),postoperative TNM stage(HR=2.55,95%CI 1.05-6.18,P=0.038),neoadjuvant therapy(HR=2.75,95%CI 1.07-7.05,P=0.036),anastomosis-related complications(HR=4.52,95%CI 1.81-11.29,P=0.001),and disease recurrence(HR=24.83,95%CI 2.90-213.06,P=0.003)were significant independent risk factors for a defunctioning stoma to be permanent.Conclusions::Defunctioning stoma is an effective method to reduce symptomatic anastomotic leakage,but the stoma itself and its reversal procedure are associated with high morbidity of complications,and many defunctioning stomas eventually become permanent.Therefore,surgeons should carefully assess preoperatively and perform defunctioning stomas in very high risk patients.In addition,doctors should perform stoma reversal surgery more actively to prevent temporary stomas from becoming permanent.
基金supported by grants from the National Natural Science Foundation of China(No.81974382)the Major Scientific and Technological Innovation Projects in Hubei Province(No.2018ACA136)the Innovative Team for Human Major Diseases Program,Tongji Medical College,Huazhong University of Science and Technology.
文摘Objective Anastomotic leakage(AL)is one of the serious complications after anterior resection for rectal cancer.Defunctioning stoma(DS)is one of the most widely used approaches to prevent it;however,the effect of DS on the occurrence of AL remains controversial.This study aimed to investigate risk factors of AL and assess the effect of DS after anterior resection for rectal cancer patients.Methods A retrospective analysis was conducted for the data of 1840 patients who underwent anterior resection for rectal cancer from January 2014 to December 2019.Results The results showed the overall AL incidence was 7.5%.Multivariate analyses revealed that males[odds ratio(OR)1.562]and T3–T4 stage(OR 1.729)were independent risk factors for all patients.After propensity score matching analysis,the AL incidence was 14.1%in the group with no DS and 6.4%in the DS group(P<0.001).The clinical AL(grade B+grade C)incidence was 12.4%in no DS group and 4.6%in the DS group(P<0.001).Conclusion The study suggested that males and T3–T4 stage were independent risk factors of AL.In addition,DS could reduce the rate of symptomatic AL.
