The development of laparoscopic total mesorectal excision (TME) has been promoting the better understanding of the anatomy in pre-rectal space for surgeons.If the dissection in pre-rectal space was inappropriate and entered into wrong anatomic planes,it would be easier to cause the proper fascia of rectum incomplete and damage the neurovascular bundies,and reduce the radical surgery outcome and induce urinary and sexual dysfunction,finally,affect the prognosis in patients.For surgical approach in pre-rectal space,the author proposed:Based on the related literatures,transecting the Denonvilliers' fascia (DVF) when it's definitely thickened after cutting the peritoneum 0.5 cm anterior to peri-toneal reflection,entering and dissecting in the space between DVF and the proper fascia of rectum,and forming a typical Three-line feature,including the cutting line of peritoneal reflection,the proximal and distal cutting lines of DVF,which can serve as the mark line and mark plane of the entrance to pre-rectal space.Not only this approach can keep the proper completeness of rectal fascia,but also it maximally reserves the DVF.Here,this article discussed the embryonic origins and anatomic characters of DVF,the structures of neurovascular bundles,dissection in the pre-rectal space,surgical approach and clinical outcomes between DVF and laparoscopic TME.

Objective To investigate the safety and short-term outcomes of laparoscopic abdominoperineal resection with pelvic peritoneum closure (LARP-PPC) for low rectal cancer.Methods The retrospective cohort study was conducted.The clinicopathological data of 132 patients with low rectal cancer who were admitted to Ruijin Hospital of Shanghai JiaoTong University School of Medicine from January 2014 to December 2017 were collected.There were 81 males and 51 females,aged from 45 to 83 years,with an average age of 62 years.Among the 132 patients,60 undergoing LARP-PPC were allocated into LARP-PPC group,and 72 patients undergoing conventional LARP were allocated into LARP group.All the patients received standardized preoperative and postoperative treatments.Observation indicators:(1) surgical and postoperative conditions;(2) postoperative pathological examination;(3) postoperative complications.The measurement data with normal distribution were expressed as Mean±SD,and the t test was used for comparison between groups.The measurement data with skewed distribution were expressed as M (range),and the Mann-Whitney U test was used for comparison between groups.The count data were expressed as absolute numbers,and the chi-square test or the Fisher exact probability was used for comparison between groups.Mann-Whitney U test was used for comparison of ordinal data between groups.Results (1) Surgery and postoperative conditions:all the patients in the two groups underwent successful surgery without conversion to open surgery.The operation time,volume of intraoperative blood loss,time to first flatus,and time to first liquid intake of the LARP-PPC group were (163±45) minutes,168 mL(range,85-280 mL),2 days(range,1-5 days),3 days(range,2-6 days),versus (155±39) minutes,160 mL(range,100-305 mL),3 days(range,1-7 days),4 days(range,2-7 days) of the LARP group;there was no differencebetween the two group (t =1.113,Z =-1.623,-1.468,-0.321,P＞0.05).The duration of postoperative hospital stay in the LARP-PPC group and the LARP group were 16 days (range,11-21 days) and 19 days (14-24 days),respectively,with a significant difference between the two groups (Z =-5.888,P＜0.05)].In the LARP-PPC group,time of PPC was (13± 3) minutes.(2) Postoperative pathological examination:the length of specimen,the number of lymph node dissection,tumor diameter,cases with high-,middle-,and low-differentiated tumor in the LARP-PPC group was (18±4)cm,16±t5,(3.7±1.4)cm,10,34,16 in the LARP-PPC group,and (18±4)cm,16±5,(3.9±1.5) cm,13,41,18 in the LARP group,showing no significant difference between the two groups (t =0.779,0.390,0.703,Z=-0.267,P＞0.05).(3) Postoperative complications:cases with perineal wound infection,delayed perineal wound healing,intestinal obstruction,and perineal hernia were 2,1,1,0 in the LARP-PPC group,and 12,10,8,6 in the LARP group,showing significant differences between the two groups (x2 =6.137,6.400,P＜0.05).There were 2 and 4 patients with urinary tract infection in the LARP-PPC group and the LARP group,respectively,showing no significant difference between the two groups (P ＞ 0.05).Conclusion LARP-PPC is safe and feasible for the treatment of low rectal cancer,which can significantly reduce postoperative perineal-related complications and consequently shorten postoperative hospital stay.

Objective:To investigate the clinical efficacy and prognosis of simultaneous resection of synchronous colorectal liver metastasis in patients admitted in different phases.Methods:The retrospective cohort study was conducted. The clinicopathological data of 346 patients who underwent simultaneous resection of synchronous colorectal liver metastasis in the First Affiliated Hospital of Naval Medical University (Changhai Hospital of Shanghai) from January 2000 to April 2021 were collected. There were 217 males and 129 females, aged (58±12)years. Patients under-went simultaneous resection of synchronous colorectal liver metastasis. Observation indicators: (1) clinicopathological features of patients with synchronous colorectal liver metastasis in 2000?2010 and 2011?2021; (2) surgical and postoperative situations of patients with synchronous colorectal liver metastasis in 2000?2010 and 2011?2021; (3) analysis of prognosis of patients with synchro-nous colorectal liver metastasis in 2000?2010 and 2011?2021. Follow-up was conducted using telephone interview or outpatient examination to detect survival of patients. The follow-up was performed once every 3 months, including blood routine test, liver and kidney function test, car-cinoembryonic antigen (CEA) test, CA19-9 test, abdominal B-ultrasound examination, and once every 6 months, including chest computed tomography (CT) plain scan, liver magnetic resonance imaging (MRI) and/or CT enhanced scan, abdominal or pelvic MRI and/or CT enhanced scan, within postoperative 2 year. The follow-up was performed once every 6?12 months within postoperative 2?5 years including above reexaminations. Electronic colonoscopy was performed once a year after operation. The follow-up was up to November 12, 2021. Measurement data with normal distribution were represented as Mean± SD, and comparison between groups was conducted using the t test. Measurement data with skewed distuibution were represented as M(range). Count data were described as absolute numbers, and comparison between groups was conducted using the chi-square test. Comparison of ordinal data was conducted using the rank sum test. Kaplan-Meier method was used to calculate survival rates and draw survival curves, and Log-Rank test was used to conduct survival analysis. Results:(1) Clinicopathological features of patients with synchronous colorectal liver metastasis in 2000?2010 and 2011?2021. Of the 346 patients, 59 cases underwent simultaneous resection within 2000?2010 and 287 cases underwent simultaneous resection within 2011?2021. The gender (males and females), cases with or without fundamental diseases, cases with the number of lymph nodes harvested in primary lesion as <12 or ≥12, the tumor diameter of primary lesion, the tumor diameter of liver metastasis lesion, the number of liver metastasis lesions, cases with or without preoperative treatment, cases with or without postoperative treatment, cases with adjuvant therapy as perioperative treatment, surgery or other treatment were 47, 12, 36, 23, 19, 40, (5.5±2.4)cm, (2.1±0.7)cm, 1.6±0.5, 59, 0, 16, 16, 0, 16, 43 in patients admitted in 2000?2010, respectively. The above indicators in patients admitted in 2011?2021 were 170, 117, 121, 166, 58, 229, (4.2±2.0)cm, (3.0±2.0)cm, 1.9±1.4, 208, 79, 34, 235, 74, 29, 184, respectively. There were significant differences in the above indicators between patients admitted in 2000?2010 and 2011?2021 ( χ2=8.73, 7.02, 4.07, t= 4.40, ?6.04, ?3.10, χ2=21.05, 28.82, 26.68, P<0.05). (2) Surgical and postoperative situations of patients with synchronous colorectal liver metastasis in 2000?2010 and 2011?2021. Cases with surgical methods as complete open surgery or laparoscopy combined with open surgery, the operation time, time to postoperative initial liquid food intake, cases with or without postoperative complications, cases with postoperative duration of hospital stay as ≤10 days or >10 days were 58, 1, (281±57)minutes, (5±1)days, 33, 26, 14, 45 in patients admitted in 2000?2010, respec-tively. The above indicators in patients admitted in 2011?2021 were 140, 147, (261±82)minutes, (3±1)days, 233, 54, 198, 89, respectively. There were significant differences in the above indicators between patients admitted in 2000?2010 and 2011?2021 ( χ2=49.04, t=2.24, 7.53, χ2=17.56, 26.02, P<0.05). There was no death in the 346 patients. (3) Analysis of prognosis of patients with synchro-nous colorectal liver metastasis in 2000?2010 and 2011?2021. Of the 346 patients, 295 cases were followed up for 47(range, 1?108)months. Of the 29 patients admitted in 2000?2010 who were followed up, there were 27 cases died. The median survival time, 1-, 3-, 5-year overall survival rates, 1-, 3-, 5-year disease free survival rates of patients admitted in 2000?2010 were 18.0 months (95% confidence interval as 12.7?23.3 months), 82.8%, 11.5%, 3.8%, 53.6%, 8.3%, 4.2%, respec-tively. Of the 266 patients admitted in 2011?2021 who were followed up, there were 109 cases died. The median survival time, 1-, 3-, 5-year overall survival rates, 1-, 3-, 5-year disease free survival rates of patients admitted in 2011?2021 were 54.0 months (95% confidence interval as 38.1?70.4 months), 93.3%, 61.8%, 47.0%, 68.2%, 33.7%, 28.3%, respectively. There were significant differences in overall survival rate and disease free survival rate between patients admitted in 2000?2010 and 2011?2021 ( χ2=47.57, 9.17, P<0.05). Conclusions:With the increase of the operation volume of simultaneous resection of synchronous colorectal liver metastasis, the operation time, time to postoperative initial liquid food intake, postoperative duration of hospital stay and postoperative complications have significantly decreased, while the overall survival rate and disease free survival rate have significantly increased.