[Anastomotic vessels between superior mesenteric artery and inferior mesenteric artery: controversies and advances].

The anastomotic vessels between the superior mesenteric artery and the inferior mesenteric artery are vital to maintain the blood supply of the anastomosis and residual colon after colectomy. However, current studies of anastomotic vessels are facing four major obstacles: confusing nomenclature, large variability in data, diversification of research methods and incomplete information records. The existence of marginal artery has been widely proved, and its significance for blood supply is well recognized by relevant studies. In contrast, the Riolan's arch, whose connotations constantly changed over history, can not refer to a specific structure accurately. Researchers should abolish the controversial names such as Riolan's arch, select appropriate research methods and record the anastomotic vessels in detail, so as to improve the comparability between different results. The study of anastomotic vessels can help us to identify potential vascular disease, select the appropriate surgical approach, and provide appropriate treatment of the vessels in the operating area, so as to provide a theoretical foundation and practical basis for fine surgical maneuvers.

[Fat1 inhibits cell proliferation via ERK signaling pathway in esophageal squamous cell carcinoma].

Objective: To clarify the mechanism of Fat1 on the proliferation of esophageal squamous cell carcinoma (ESCC). Methods: KYSE450 cells were transfected with Plko.1-puro-GFP-shRNA-Fat1 plasmid and real time polymerase chain reaction (PCR) was used to verify the efficiency of Fat1 knockdown. The effects of Fat1 and extracellular regulated protein kinase (ERK) pathway inhibitor U0126 on the proliferation of ESCC cells were detected by methyl thiazolyl tetrazolium (MTT). Colony formation assay was used to detect the colony formation ability. Cell cycle was detected by live cell imaging. Western blot was used to observe the level of target protein. Mouse xenograft assay was applied to detect the effect of Fat1 knockdown on KYSE450 cell tumor growth. Immunohistochemistry was used to detect the expressions of related proteins in tumor sections. Results: The efficiency of Fat1 knockdown was (77.1±6.9)% in Fat1 sh1 group and (77.7±7.1)% in Fat1sh2 group. Compared with the control group, the cell proliferation and the expression of p-ERK1/2 were significantly increased in Fat1 sh1 and Fat1sh2 group (P<0.05). After U0126 treatment, the effect of Fat1 knockdown on the proliferation of KYSE450 cells disappeared, and the expression of p-ERK1/2 in KYSE450 cells decreased to a level similar to that in the control group. The number of cell clones in the control group was (72±8), lower than (155±28) and (193±9) in the Fat1sh1 and Fat1sh2 groups, respectively (P<0.05). In KYSE450 cell, division time was shortened from 1 622±32 min in control group to 1 408±29 min in Fat1 sh1 group, the difference was statistically significant (P<0.05). Compared with the control group, the tumor volume of Fat1 knockdown group increased significantly. The tumor weight of control group and Fat1 knockdown group were (0.224±0.028) g and (1.532±0.196) g, respectively, at 4 weeks after inoculation, and the difference was statistically significant (P<0.05). Conclusion: Fat1 inhibits cell proliferation via ERK signaling in ESCC.

[Controversy and consideration of high and low ligation of inferior mesenteric artery in radical resection of rectal cancer].

Radical resection is one of the most important treatment for rectal cancer, which requires not only removal of adequate bowel and mesorectum around the tumor, but also thorough lymphadenectomy. Besides, postoperative complications are surgeons' concerns as well. According to different ways to manage inferior mesenteric artery, procedures could be divided into two groups: inferior mesenteric artery (IMA) high ligation and low ligation, which lead to various outcomes of the extent of lymph nodes dissection, survival, preservation of intestinal blood supply, incidence of anastomotic leakage, and postoperative functions including defecation function, urinary function and sexual function. Author believes that for those patients with clinical stage T1, low ligation and D2 lymph nodes dissection could be considered. However, for patients with locally advanced carcinomas (clinical stage T2+or N+), especially suspicious metastasis of lymph nodes around IMA root, high ligation and D3 lymph node dissection is suggested to ensure en bloc resection. As for those patients with high risks for compromised intestinal blood supply, preservation of left colic artery plus D3 lymph nodes dissection might be a feasible way. Intraoperative indocyanine green fluorescent imaging might play a role in quality control of lymphadenectomy.

[Comparative study of functional prognosis of transanal total mesorectal excision and conventional total mesorectal excision based on propensity score matching].

Objective: To compare the postoperative functional prognosis of transanal mesorectal excision (taTME) and conventional total mesorectal excision (TME) in rectal cancer. Methods: Totally 49 patients underwent taTME and 478 patients underwent conventional TME at Department of Gastroenterological Surgery, Peking University People's Hospital from January 2015 to December 2019 were retrospectively collected. Propensity score matching method was used to perform 1 versus 1 matching between the taTME and conventional TME groups, and 36 pairs of patients were successfully matched. After matching, the median age of patients in taTME group and conventional TME group was 60.5 (16.0) years and 60.5 (13.0) years (M(Q(R))), respectively, and the proportion of male patients was 66.7% (24/36) and 55.6% (20/36) , respectively. EORTC QLQ-C30 scale was used to assess quality of life, low anterior resection syndrome (LARS) scale and Wexner constipation score were used to evaluate anal function, international prostate symptom score (IPSS) was used to evaluate urinary function,international index of erectile function (IIEF) -5 and female sexual function index (FSFI) score were used to evaluate male and female sexual function, respectively, and generalized anxiety disorder (GAD-7) and patient health questionnaire (PHQ-9) scale were used to evaluate psych function. The t test, Mann-Whitney U test, χ(2) test, and Fisher exact test were used for comparison between groups, and Wilcoxon rank sum test or McNemar test was used for comparison between paired data. Results: There were no significant differences in surgery time, postoperative hospital stays, conversion rate, morbidity rate, surgery cost, and numbers of lymph node yield between the two groups (all P>0.05). Compared with the conventional TME group, the intraoperative blood loss in the taTME group was significantly higher (100 (100) ml vs. 80 (50) ml, U=424.5, P=0.010), the prophylactic stoma rate was significantly higher (96.9%(31/36) vs. 63.6%(21/36), χ(2)=11.218, P<0.01), the total hospitalization cost was significantly lower (74 297.7 (16 746.4) CNY vs. 91 781.3 (26 228.4) CNY, U=413.0, P=0.008). There were no significant differences in anal and urinary function between the two groups (LARS scalescore: Z=-0.513, P=0.608, Wexner constipation score: Z=-0.992, P=0.321, IPSS: Z=-1.807, P=0.071). In terms of psych function, significant difference in GAD-7 scale was seen between the two groups (Z=-2.311, P=0.021), patients with generalized anxiety disorder accounting for 26.7% (8/30) and 46.9% (15/32), respectively. Conclusions: Compared with conventional TME surgery, taTME has a significantly increased blood loss and prophylactic stoma rate. There are no significant difference in the incidence of postoperative anal, urinary, and sexual dysfunction between taTME and conventinal TME. taTME can alleviate the financial burden and general anxiety disorder to a certain extent.

[Detection of preoperative chemoradiotherapy sensitivity molecular characteristics of rectal cancer by transcriptome second generation sequencing].

OBJECTIVE: To detect the preoperative chemoradiotherapy sensitivity molecular characteristics of rectal cancer by transcriptome second generation sequencing. METHODS: The clinicopathological data of 30 patients with locally advanced rectal cancer were collected prospectively, including 9 indicators (general conditions, imaging data before radiotherapy and chemotherapy, pathological data of biopsy before radiotherapy and chemotherapy, and tumor differentiation degree, etc.), in order to analyze the correlation between them and tumor regression grading (TRG) after radiotherapy and chemotherapy for rectal cancer. At the same time, frozen specimens of colonoscopy biopsy before neoadjuvant therapy were collected from these 30 patients, and transcriptome second-generation sequencing was performed for bioinformatics analysis to screen out the genes that might drive the radio chemotherapy sensitivity of rectal cancer. RESULTS: Among the 30 patients with rectal cancer, 9 had complete pathological remission, 12 had partial remission, and 9 had poor remission. The degree of pathological TRG remission after radiotherapy and chemotherapy for rectal cancer was negatively correlated with the preoperative MRI T stage (P=0.046), and positively correlated with preoperative MRI rectal cancer extravascular invasion (EMVI) (P=0.003). Transcriptome second-generation sequencing of the obtained 217 transcripts (P<0.05) for signal pathway enrichment analysis, and multiple cell signal transduction pathways related to antigen presentation could be found. The high expression of HSPA1A, HSPA1B and EXOSC2 was positively correlated with postoperative pathological remission (P<0.05). The high expression of DNMBP, WASH8P, FAM57A, and SGSM2 was positively correlated with postoperative pathological remission (P<0.05). CONCLUSION: Preoperative NMR detection of extra-tumoral vascular invasion (EMVI-positive) in patients with rectal cancer was significantly better than that of EMVI-negative patients after chemoradiotherapy. Patients with high expressions of HSPA1A, HSPA1B and EXOSC2 had poor postoperative pathological remission, while patients with high expressions of genes, such as DMNMB, WASH8P, FAM57A, and SGSM2 had good postoperative pathological remission. Based on the molecular characteristics of rectal cancer radiotherapy and chemotherapy, attempts to block or enhance the molecular pathways associated with chemosensitivity of rectal cancer, are to be made to further explore new candidate therapeutic targets that can increase the sensitivity of radiotherapy and chemotherapy for rectal cancer.

[Multi-site analysis of acute effects of air pollutants combination exposure on mortality in Jiangsu Province, China].

Objective: To explore the acute effect of fine particulate matters (PM(2.5)), O(3), NO(2) on daily non-accidental mortality, cardiovascular disease mortality and respiratory mortality data in thirteen cities of Jiangsu province. Methods: Daily average concentrations of non-accidental mortality, cardiovascular disease mortality, respiratory mortality data and environmental data were collected from January 1, 2015 to December 31, 2017 in thirteen cities of Jiangsu Province. Daily air quality, mortality and meteorology data were collected from the Information System of Air Pollution and Health Impact Monitoring of Chinese Center for Disease Control and Prevention. We used generalized additive model to evaluate the association between daily concentrations of air pollutants and mortality at single-city level and multi-city level, after adjusting the long-term and seasonal trend, as well as meteorological factors and the effect of "days and weeks" . A multivariate Meta-analysis with random effects was applied to estimate dose-response relationship between air pollutants and mortality. Results: At multi-city level, per interquartile range increase of PM(2.5), O(3), NO(2) was associated with an increase of 1.10% (95%CI: 0.66%, 1.54%), 0.59% (95%CI: 0.18%, 1.00%), 2.00% (95%CI: 1.29%, 2.72%) of daily non-accidental mortality respectively; 1.01% (95%CI: 0.63%, 1.38%), 0.66% (95%CI: 0.02%, 1.30%), 1.62% (95%CI: 1.00%, 2.23%) of daily cardiovascular mortality respectively; 1.09% (95%CI: 0.35%, 1.82%), 0.44% (95%CI: -0.29%, 1.16%), 2.75% (95%CI: 1.42%, 4.08%) of daily respiratory mortality respectively. The air pollutants effect varied across different cities. The strongest effect of PM(2.5) was current day (excess risk (ER)=1.10%, 95%CI: 0.66%, 1.54%)), the strongest effect of O(3) was 2-day lag (ER=1.82%, 95%CI: 0.69%, 2.97%) and the strongest effect of NO(2) was 1-day lag (ER=2.09%, 95%CI: 1.34%, 2.83%) of daily non-accidental mortality respectively. Conclusion: The increases of PM(2.5) and NO(2) concentration could result in the increases of daily non-accidental mortality, cardiovascular disease mortality and respiratory mortality. O(3) could result in the increases of daily non-accidental mortality and cardiovascular disease mortality. The acute effects for non-accidental mortality from high to low were NO(2), PM(2.5) and O(3,) and the strongest effect of PM(2.5) was current day. O(3) and NO(2) had lagged effects.

[Efficacy of Weitan Waifu patch on the postsurgical gastroparesis syndrome of gastrointestinal cancer: a multi-center trial].

Objective: To investigate the safety and efficacy of the Weitan Waifu patch on the postsurgical gastroparesis syndrome (PGS) of gastrointestinal cancer. Methods: The multi-center, double-blind, randomized controlled trial was conducted with superiority design. Patients with PGS of gastrointestinal cancer diagnosed in 4 AAA hospitals and the abdominal symptom manifested as cold syndrome by Chinese local syndrome differentiation were recruited. These patients were randomly divided into two groups according to 1∶1 proportion. Placebo or Weitan Waifu patch was applied in control group or intervention group, respectively, based on the basic treatments, including nutrition support, gastrointestinal decompression, promoting gastric dynamics medicine.Two acupuncture points (Zhongwan and Shenque) were stuck with placebo in control group or patch in treatment group. The intervention course was 14 days or reached the effective standard. Results: From July 15, 2013 to Jun 3, 2015, 128 participants were recruited and 120 eligible cases were included in the full analysis set (FAS), and 60 cases in each group. 88 cases were included in the per-protocol set (PPS), including 45 cases in the treatment group and 43 cases in the control group. In the FAS, the clinical effective rate in the treatment group was 68.3%, significantly superior than 41.7% of the control group (P=0.003). The medium time of effective therapy in the treatment group was 8 days, significantly shorter than 10 days in the control group (P=0.017). In the FAS, 3 adverse events occurred in the treatment group, including mild to moderate decrustation, pruritus and nausea. The incidence rate of adverse events was 5.0% (3/60) and these symptoms were spontaneously remitted after drug withdrawal. No severe adverse events were observed in the control group. There was no significant difference between these two groups (P=0.244). Conclusion: Weitan Waifu patch is a safely and effectively therapeutic method for patients with PGS (cold syndrome) of gastroenterological cancer. Trial registration: International Standard Randomized Controlled Trial Number Register, ISRCTN18291857.

[Adenocarcinoma in a Meckel's diverticulum with multiple liver metastases and gastrointestinal hemorrhage: a case report].

Meckel's diverticulum is the most common congenital anomaly of the gastrointestinal tract, affecting approximately 2% of the population. It is a true diverticulum occurring on the anti-mesenteric border of the distalileum, typically within 100 cm of the ileo-caecal valve. Neoplasms arising in Meckel's diverticula are uncommon, and those reported in the literature are mainly carcinoid tumors, followed by gastrointestinal stromal tumors (GIST) and benign leiomyomas. Adenocarcinomas are extremely rare. Tumors in Meckel's present non-specifically with gastrointestinal complaints, such as bleeding, obstruction, inflammation or perforation. The suspicion of a Meckel's tumor is often not thought of at the initial. In this article we describe a 57-year-old woman who presented with massive rectal bleeding and severe anemia, later found to be caused by a adenocarcinoma arising from Meckel's diverticulum. The tumor was unfortunately highly aggressive. Multiple liver metastases had already existed when we discovered the primary mass. Later we performed a partial resection of the ileumto cease the bleeding. Meckel's diverticulum and the tumor were resected simultaneously. The pathological diagnosis confirmed adenocarcinoma arising from the Meckel's diverticulum. The final stage was pT4NxM1, stage IV according to the Union for International Cancer Control (UICC) classification. After operation we gave the patient first-line, mFOLFOX6 chemotherapy, but it turned out to be not effective. Rapid progress of the liver metastases and suspicion of multiple lung metastasis in short time after therapy indicated a bad outcome. We believe this is the first case of adenocarcinoma in a Meckel's diverticulum to be reported in domestic literature. The diagnosis of Meckel's tumor should be considered as inpatients'acute gastrointestinal complaints; when found incidentally at laparotomy, it should be carefully examined for any gross abnormality and resection should be considered.

Screening of molecular markers linked to dwarf trait in crape myrtle by bulked segregant analysis.

Plant height is one of the most important traits of plant architecture as it modulates both economic and ornamental values. Crape myrtle (Lagerstroemia indica L.) is a popular ornamental woody plant because of its long-lasting mid-summer bloom, rich colors, and diversified plant architecture. These traits also make it an ideal model of woody species for genetic analysis of many ornamental traits. To understand the inheritance of plant height and screen for genes modulating plant height in Lagerstroemia, segregation of the plant height trait was analyzed using the F1 population of L. fauriei (standard) x L. indica 'Pocomoke' (dwarf) with 96 seedlings, while dwarf genes were screened using the bulked segregant analysis method, combined with 28 amplified fragment length polymorphism primers and 41 simple sequence repeat primers. The results showed that the dwarf trait of crape myrtle was controlled by a major gene and modified by minor genes. An amplified fragment length polymorphism marker, M53E39-92, which was 23.33 cM from the loci controlling the dwarf trait, was screened. These results provide basic information for marker-assisted selection in Lagerstromia and cloning of dwarf genes in future studies.

[Cross-sectional study of low anterior resection syndrome in patients who have survived more than 5 years after sphincter-preserving surgery for rectal cancer].

Objective: In this study, we aimed to investigate the prevalence of low anterior resection syndrome (LARS) in patients who had survived for more than 5 years after sphincter-preserving surgery for rectal cancer and to analyze its relationship with postoperative time. Methods: This was a single-center, retrospective, cross-sectional study. The study cohort comprised patients who had survived for at least 5 years (60 months) after undergoing sphincter- preserving radical resection of pathologically diagnosed rectal adenocarcinoma within 15 cm of the anal verge in the Department of Gastrointestinal Surgery, Peking University People's Hospital from January 2005 to May 2016. Patients who had undergone local resection, had permanent stomas, recurrent intestinal infection, local recurrence, history of previous anorectal surgery, or long- term preoperative defecation disorders were excluded. A LARS questionnaire was administered by telephone interview, points being allocated for incontinence for flatus (0-7 points), incontinence for liquid stools (0-3 points), frequency of bowel movements (0-5 points), clustering of stools (0-11 points), and urgency (0-16 points). The patients were allocated to three groups based on these scores: no LARS (0-20 points), minor LARS (21-29 points), and major LARS (30-42 points). The prevalence of LARS and major LARS in patients who had survived more than 5 years after surgery, correlation between postoperative time and LARS score, and whether postoperative time was a risk factor for major LARS and LARS symptoms were analyzed. Results: The median follow-up time of the 160 patients who completed the telephone interview was 97 (60-193) months; 81 (50.6%) of them had LARS, comprising 34 (21.3%) with minor LARS and 47 (29.4%) with major LARS. Spearman correlation analysis showed no significant correlation between LARS score and postoperative time (correlation coefficient α=-0.016, P=0.832). Multivariate analysis identified anastomotic height (RR=0.850, P=0.022) and radiotherapy (RR=5.760, P<0.001) as independent risk factors for major LARS; whereas the postoperative time was not a significant risk factor (RR=1.003, P=0.598). The postoperative time was also not associated with LARS score rank and frequency of bowel movements, clustering, or urgency (P>0.05). However, the rates of incontinence for flatus (3/31, P=0.003) and incontinence for liquid stools (8/31, P=0.005) were lower in patients who had survived more than 10 years after surgery. Conclusions: Patients with rectal cancer who have survived more than 5 years after sphincter-preserving surgery still have a high prevalence of LARS. We found no evidence of major LARS symptoms resolving over time.

[Correlation between pelvic relapses of rectal cancer after radical and R0 resection: A regression model-based analysis].

Objective: To propose a new staging system for presacral recurrence of rectal cancer and explore the factors influencing radical resection of such recurrences based on this staging system. Methods: In this retrospective observational study, clinical data of 51 patients with presacral recurrence of rectal cancer who had undergone surgical treatment in the Department of Gastrointestinal Surgery, Peking University People's Hospital between January 2008 and September 2022 were collected. Inclusion criteria were as follows: (1) primary rectal cancer without distant metastasis that had been radically resected; (2) pre-sacral recurrence of rectal cancer confirmed by multi-disciplinary team assessment based on CT, MRI, positron emission tomography, physical examination, surgical exploration, and pathological examination of biopsy tissue in some cases; and (3) complete inpatient, outpatient and follow-up data. The patients were allocated to radical resection and non-radical resection groups according to postoperative pathological findings. The study included: (1) classification of pre-sacral recurrence of rectal cancer according to its anatomical characteristics as follows: Type I: no involvement of the sacrum; Type II: involvement of the low sacrum, but no other sites; Type III: involvement of the high sacrum, but no other sites; and Type IV: involvement of the sacrum and other sites. (2) Assessment of postoperative presacral recurrence, overall survival from surgery to recurrence, and duration of disease-free survival. (3) Analysis of factors affecting radical resection of pre-sacral recurrence of rectal cancer. Non-normally distributed measures are expressed as median (range). The Mann-Whitney U test was used for comparison between groups. Results: The median follow-up was 25 (2-96) months with a 100% follow-up rate. The rate of metachronic distant metastasis was significantly lower in the radical resection than in the non-radical resection group (24.1% [7/29] vs. 54.5% [12/22], χ2=8.333, P=0.026). Postoperative disease-free survival was longer in the radical resection group (32.7 months [3.0-63.0] vs. 16.1 [1.0-41.0], Z=8.907, P=0.005). Overall survival was longer in the radical resection group (39.2 [3.0-66.0] months vs. 28.1 [1.0-52.0] months, Z=1.042, P=0.354). According to univariate analysis, age, sex, distance between the tumor and anal verge, primary tumor pT stage, and primary tumor grading were not associated with achieving R0 resection of presacral recurrences of rectal cancer (all P>0.05), whereas primary tumor pN stage, anatomic staging of presacral recurrence, and procedure for managing presacral recurrence were associated with rate of R0 resection (all P<0.05). According to multifactorial analysis, the pathological stage of the primary tumor pN1-2 (OR=3.506, 95% CI: 1.089-11.291, P=0.035), type of procedure (transabdominal resection: OR=29.250, 95% CI: 2.789 - 306.811, P=0.005; combined abdominal perineal resection: OR=26.000, 95% CI: 2.219-304.702, P=0.009), and anatomical stage of presacral recurrence (Type III: OR=16.000, 95% CI: 1.542 - 166.305, P = 0.020; type IV: OR= 36.667, 95% CI: 3.261 - 412.258, P = 0.004) were all independent risk factors for achieving radical resection of anterior sacral recurrence after rectal cancer surgery. Conclusion: Stage of presacral recurrences of rectal cancer is an independent predictor of achieving R0 resection. It is possible to predict whether radical resection can be achieved on the basis of the patient's medical history.

[Influence of different sphincter-preserving surgeries on postoperative defecation function].

Advances in surgical techniques and treatment concept have allowed more patients with low rectal cancer to preserve sphincter without sacrificing survival benefit. However, postoperative dysfunctions such as fecal incontinence, frequency, urgency, and clustering often occur in patients with low rectal cancer. The main surgical procedures for low rectal cancer include low anterior rectum resection (LAR), intersphincteric resection (ISR), coloanal anastomosis (Parks) and so on. The incidence of major LARS after LAR is up to 84.6%. The postoperative function of ISR is even worse than LAR. Moreover, the greater the extent of resection ISR surgery, the worse the postoperative function. There are few studies on the function of Parks procedure. Current evidence suggests that the short-term function of Parks procedure is inferior to LAR, but function can gradually recovered over time. Colorectal surgeons have attempted to improve postoperative defecation by modifying bowel reconstructions. Current evidence suggests that J pouch or end-to-side anastomosis during LAR does not reduce the incidence of defecation disorders. Pouch reconstruction during ISR cannot reduce the incidence of severe LARS either. In general, the protection of postoperative defecation function in patients with low rectal cancer still has a long way to go.

[Research progress of colorectal surgery in 2021 and future prospects].

In recent years, with the wide application of immune score and liquid biopsy to guide the accurate diagnosis and precise treatment of colorectal cancer, colorectal surgery develops more rationally and scientifically. The strategy of organ function protection in colorectal surgery gradually attracts more and more attention. The continuous development of comprehensive treatments, such as targeted therapy and immunotherapy, provides more choices for colorectal cancer patients. Several significant progress in surgical strategies for benign colorectal diseases challenges the traditional concepts as well. The advances in medical science and the innovation of concepts and ideas set high new standards for the development of colorectal surgery in China. Efforts are required to improve the standardization of diagnosis and treatment of colorectal disease. There is still a long way to go to explore patient-centered new technologies, new concepts and new fields of accurate diagnosis and precise treatment in colorectal surgery.

[Pros and cons of perioperative therapy in the protection of organ function in rectal cancer].

The goal of rectal cancer treatment should be to better protect organ function and improve patients' quality of life on the basis of ensuring radical resection. The current evidence has proved the superiority of perioperative chemoradiotherapy in reducing local recurrence and improving long-term survival. From the perspective of organ function protection, however, perioperative chemoradiotherapy has both disadvantages and advantages. Despite the great help in improving long-term outcomes, adverse reactions of chemoradiotherapy can aggravate defecation, urination and sexual dysfunction. Also, for patients with significant or complete remission, if the treatment strategy of local resection or close follow-up is selected, organ function can be preserved to the greatest extent. The key to the choice of treatment is to evaluate preoperatively whether pathological complete response is achieved. It should be kept in mind that preserving organ itself is not the same as protecting organ function. For patients who need perioperative chemoradiation, the optimal treatment methods should be chosen based on the patient's condition. Surgeons should fully evaluate organ function before operation, select the appropriate treatment strategy, pay special attention to the protection of important organs and nerves during surgeries, and carry out close postoperative follow-up and organ function rehabilitation as soon as possible, so as to reduce the incidence of dysfunction and the impact on the quality of life.

[Research progress of different bowel reconstructions for postoperative functional protection during low anterior resections of rectal cancer].

Straight coloanal anastomosis (SCA), colonic J-pouch anastomosis (CJP), transverse coloplasty pouch anastomosis (TCP), and side-to-end anastomosis (SEA) are the most commonly used procedures of bowel reconstructions in the low anterior resections (LAR) of rectal cancer. Different bowel reconstruction procedures greatly affect postoperative bowel function, urinary function and sexual function. SCA is the most traditional procedure. CJP has been studied extensively and well-developed reconstruction method; however, recent studies have shown that CJP has the highest morbidity of complications, so the clinical application of CJP is limited. SEA is not inferior to CJP and SCA in the short-term and long-term defecation function, urination function, and sexual function, with reliable operational safety, so it is expected to become an alternative to SCA and CJP. The research on TCP is lacking, but there are some related clinical trials currently underway, and the results are worth expecting. The improvement and innovation of bowel reconstructions provide a bright prospect for better functional prognosis in patients with rectal cancer.

[Research progress of single-incision laparoscopic radical gastrectomy].

Gastric cancer is one of the most common malignant diseases in the world, which has a high incidence in our country and threatens people's health seriously. Laparoscopic radical gastrectomy is one of the main methods of surgical treatment for gastric cancer, whose clinical application has a history of near 30 years. With the in-depth understanding of minimally invasive surgery and the improvement of patients' cosmetic demand, single-incision laparoscopic surgery has emerged. Since the first report of single-incision laparoscopic radical gastrectomy in 2010, its safety has been preliminarily confirmed. While this result still needs to be further verified by more prospective randomized controlled studies. Compared with traditional laparoscopic radical gastrectomy, single-incision laparoscopic radical gastrectomy has the advantages of less trauma, less postoperative pain and faster postoperative recovery. So it has been favored by surgeons. However, the steeper learning curve and difficult operation of single-incision laparoscopic radical gastrectomy limit its promotion in clinical applications. At present, there are still controversies and confusions in the single-incision laparoscopic radical gastrectomy. This article elucidates the advances and existing problems of single-incision laparoscopic radical gastrectomy.

[Investigation on the status quo of diagnosis and treatment related to the protection of defecation function in sphincter-preserving resections for rectal cancer: a cross-sectional study of Chinese colorectal surgeons].

Objective: To understand the current status of diagnosis and treatment regarding the protection of defecation function in Chinese surgeons performing sphincter-preserving resections (SPR) for rectal cancer in order to discover the problems existing in the function protection during SPR and provide support and reference for the standardized clinical management of rectal cancer. Methods: A cross-sectional survey was performed. Colorectal surgeons who obtained the medical qualifications and volunteered to participate in this study were included, and respondents with incomplete information were excluded. From October 18 to 22, 2020, randomized sampling was conducted among Chinese colorectal surgeons from Chinese Association of Colorectal Surgeons, Chinese Colorectal Cancer Committee, Chinese Sexology Association Anal functional Surgery Committee and National Health Commission Capacity Building and Continuing Education Committee. The questionnaire included basic information of the respondents, assessment of defecation function before SPR, intraoperative details, postoperative follow-up, evaluation and intervention of patients with low anterior resection syndrome (LARS). Observation indicator: results of the questionnaire survey. Result: A total of 231 questionnaires were collected, and 230 were effective, with an effective rate of 99.6%. Among these participants, 217 (94.3%) were males; 107 (46.5%) had medical doctor degrees; 129 (56.1%) were national commission members in colorectal surgery; 137 (59.6%) performed more than 50 SPR operations per year; 211 (91.7%) assessed defection function by auxiliary examinations before SPR. Rigid sigmoidoscopy (n=116, 55.0%) and anorectal manometer (n=81, 38.4%) were the most commonly used method. Among the 230 respondents, 64.8% (n=149) of surgeons used 2D laparoscopy for SPR surgery most commonly, and 51.3% (n=118) of surgeons performed direct colorectal anastomosis for reconstruction, and 98.3% (n=226) used staplers during anastomosis. All the surgeons indicated that they would follow up patients after SPR, and outpatient clinic was the most common method (84.4%, 184/230). When LARS occurred, 50.0% (115/230) of surgeons chose defecation function scale and 78.7% (181/230) actively provided guidance and intervention for patients. Conclusions: Chinese colorectal surgeons still have shortcomings in the protection of defecation function during SPR for rectal cancer. They do not make enough preoperative functional evaluation and postoperative functional recovery estimate for patients. The knowledge and use of defecation function scales and interventions on LARS are expected to be standardized.

[Research progress of sexual dysfunction following rectal cancer surgery].

Sexual dysfunction with the incidence of 5%-90% is a common postoperative complication of rectal cancer and the ratio of men and women is similar. Sexual function is innervated by the abdominal-pelvic autonomic nerve. Different sexual dysfunctions can be caused by different parts and degrees of injury in autonomic nerve during operations of rectal cancer. With the development of pelvic autonomic nerves preservation in rectal cancer radical resection, postoperative sexual function can be protected. There may be many factors increasing the incidence of postoperative sexual dysfunction in rectal cancer, such as postoperative psychological factors, stoma, abdominal-perineal resection and radiotherapy. The effects of laparoscopic surgery, robotic surgery, transanal total mesorectal excision and lateral lymph node dissection on postoperative sexual function remain controversial. Based on the multidisciplinary cooperation model, attention should be paid to psychological intervention of patients and their partners. In clinical practice, for male using phosphodiesterase-5 inhibitors, vacuum erectile devices, injection of vasodilators through the penis or urethra, and for female local application of estrogen and lubricants in the vagina are effective treatment for postoperative sexual dysfunction of rectal cancer. In addition, stem cell therapy has a promising prospect for sexual dysfunction.

[Safety and efficacy of adjuvant chemotherapy with oxaliplatin and S-1 for patients with locally advanced gastric cancer after D2 lymph nodes dissection].

Objective: To investigate the safety and efficacy of oxaliplatin combined with S-1 (SOX) as adjuvant chemotherapy after D2 radical gastrectomy for locally advanced gastric cancer. Methods: A descriptive case series study was applied. Case inclusion criteria: (1) locally advanced gastric cancer confirmed by endoscopic biopsy or surgical specimen pathology as gastric adenocarcinoma; (2) receiving D2 radical gastric resection followed by SOX regimen adjuvant chemotherapy. Case exclusion criteria: (1) postoperative pathological TNM stage I or IV; (2) acute complications and emergency surgeries; (3) receiving neoadjuvant therapy; (4) concurrent malignancies and complications compromising patients' treatment or survival; (5) without receiving adjuvant SOX chemotherapy. A total of 94 patients with stage II-III gastric cancer who underwent D2 radical gastrectomy and postoperative adjuvant SOX chemotherapy at department of Gastrointestinal Surgery, Peking University People's Hospital from January 2014 to December 2019 were retrospectively enrolled. Chemotherapy-related adverse events, overall survival (OS) and progression-free survival (PFS) were analyzed. Kaplan-Meier survival analysis was performed and log rank test was used to analyze the difference between groups. P<0.2 or clinically significant indicators in univariate analysis were included in Cox regression model for multivariate survival analysis. Results: Among these 94 patients, there were 65 males and 29 females with an average age of (58.2±12.1) years; 33 patients with hypertension, diabetes mellitus, or cardiovascular and cerebrovascular diseases, 11 patients with family history of gastrointestinal tumors; 59 patients with tumors locating in the antrum or pylorus, 16 patients in the gastric body, 19 patients in the gastric fundus or cardia; 29 patients underwent total gastrectomy, 5 patients underwent proximal subtotal gastrectomy, and 60 patients underwent distal subtotal gastrectomy. In this study, 73 patients (77.7%) completed at least 5 cycles of adjuvant SOX regimen chemotherapy. Grade 3-4 adverse reactions included thrombocytopenia (23.4%, 22/94), nausea and vomiting (18.1%, 17/94) and peripheral neurotoxicity (6.4%, 6/94). Eighty-nine patients (94.7%) completed follow-up with a median follow-up time of 32 months. The 3-year and 5-year OS rates were 89.8% and 83.7%, respectively, and the 3-year and 5-year PFS rates were 81.4% and 78.1%, respectively. Taking 5 chemotherapy cycles as the cut-off point, the 3-year OS rate and 3-year PFS rate were 72.2% and 53.9% in the adjuvant chemotherapy < 5 cycles group, and 93.7% and 87.1% in the adjuvant chemotherapy ≥5 cycles group, respectively; the differences were statistically significant (P=0.029, P=0.006). Univariate analysis showed that the adjuvant chemotherapy < 5 cycles group was associated with worse 3-year OS (P=0.029). Multivariate analysis showed that insufficient chemotherapy cycle (HR=9.419, 95% CI: 2.330-38.007, P=0.002) was an independent risk factor for 3-year OS. Meanwhile, univariate analysis showed that the adjuvant chemotherapy <5 cycles (P=0.006), preoperative CEA > 4.70 µg/L (P=0.035) and adjacent organ resection (P=0.024) were associated with worse 3-year PFS. Multivariate analysis showed that adjuvant chemotherapy <5 cycles (HR=10.493, 95% CI: 2.466-44.655, P=0.001) and adjacent organ resection (HR=127.518, 95% CI: 8.885-1 830.136, P<0.001) were independent risk factors for 3-year PFS. Conclusions: Oxaliplatin combined with S-1 as an adjuvant chemotherapy regimen for locally advanced gastric cancer has high efficacy and low incidence of adverse reactions. At least 5 cycles of SOX regimen adjuvant chemotherapy can significantly improve prognosis of patients with stage II-III gastric cancer.