Quality analysis of surgical specimens of rectal cancer in the Chinese taTME registry coll-aborative database: a nationwide registered study / 中华消化外科杂志

Objective:To analyze the quality of surgical specimens of rectal cancer in the Chinese transanal total mesorectal excision (taTME) registry collaborative (CTRC) database.Methods:The retrospective and descriptive study was conducted. Based on the concept of real-world research, the clinicopathological data of 1 761 patients with rectal cancer in the CTRC database who underwent taTME in 40 medical centers, including the Beijing Friendship Hospital of Capital Medical University et al, from November 15, 2017 to December 31, 2022 were collected. There were 1 212 males and 549 females, aged 62(range, 53-68)years. Observation indicators: (1) preoperative examinations; (2) neoadjuvant therapy; (3) postoperative examinations. Measurement data with skewed distri-bution were represented as M(range). Count data were described as absolute numbers. Results:(1) Preoperative examinations. Of the 1 761 patients, 1 324 patients underwent preoperative pelvic magnetic resonance imaging examination, and the results showed that 4 cases as clinical T0 stage, 30 cases as clinical T1 stage, 250 cases as clinical T2 stage, 828 cases as clinical T3 stage, 141 cases as clinical T4 stage, 11 cases as clinical Tx stage, 60 cases missing clinical T staging data, 490 cases as clinical N0 stage, 373 cases as clinical N1 stage, 311 cases as clinical N2 stage, 86 cases as clinical Nx stage, 64 cases missing clinical N staging data, 156 cases with mesorectal fascia invasion, 223 cases with extraintestinal blood vessels invasion. The distance from lower margin of tumor to anal margin of 1 324 patients was 50(range, 40-60)mm. (2) Neoadjuvant therapy. Of the 1 761 patients, 873 patients underwent neoadjuvant therapy, including 17 cases receiving radiotherapy alone, 155 cases receiving chemotherapy alone, 43 cases receiving short-course simultaneous chemoradiotherapy, 26 cases receiving short-course simultaneous chemoradiotherapy and delayed surgery, 1 case receiving contact radiotherapy, 277 cases receiving long-course simultaneous chemoradiotherapy, 9 cases receiving other treatments, and 345 cases missing neoadjuvant therapy data. (3) Postoperative examinations. Of the 1 761 patients, 1 584 cases achieved R 0 resection, 23 cases achieved R 1 resection, 1 case achieved R 2 resection, and there were 153 cases missing surgical margin data. The tumor diameter, number of lymph nodes harvest and positive rate of intravascular tumor thrombus were 30(range, 20-45)cm, 13(range, 10-17) and 20.794%(330/1 587) in 1 761 patients. There were 1 647 patients with circumferential margin records, which showed positive in 51 cases, and the minimum distance from deep part of tumor to circumferential margin was 5(rang, 3-13)mm in 1 647 patients. There were 547 cases with distal margin records, which showed positive in 4 cases, and the distance from lower margin of tumor to distal margin was 20(10-25)mm in 547 cases. There were 1 698 patients with specimen integrity records, which showed intact specimen in 1 436 cases, fair specimen in 233 cases, poor specimen in 8 cases, unevaluated specimen in 21 cases, and there were 20 cases with rectal tube perforation. Of the 1 761 patients, cases as pathological T0 stage, Tis stage, T1 stage, T2 stage, T3 stage, T4 stage was 103, 23, 145, 515, 712, 179, respectively, and there were 4 cases of pathology that could not be evaluated and 80 cases missing pathological T staging data. Of the 1 761 patients, cases as pathological N0 stage, N1a stage, N1b stage, N1c stage, N2a stage, N2b stage was 1 117, 189, 133, 66, 109, 68, respectively, and there were 79 cases missing pathological N staging data. Of the 1 761 patients, there were 79 cases with distant metastasis, 1 591 cases without distant metastasis, and 91 cases without data of tumor metastasis. Of the 873 patients undergoing neoadjuvant therapy, there were 405 patients with tumor regression grade records including 105 cases as grade 1, 142 cases as grade 2, 91 cases as grade 3, 43 cases as grade 4, 24 cases as grade 5. Conclusions:In China, the quality of surgical specimens of taTME for rectal cancer is good with low positive rate of resection margin. It is recommended that using a formatted postoperative pathological report for good quality control of pathological report of surgical specimen.

Technical advantages and oncological efficacy of transanal total mesorectal excision for rectal cancer / 中华消化外科杂志

Total mesorectal excision (TME) is an effective surgical method to reduce the local recurrence of rectal cancer and improve patient prognosis. However, there is debate about which surgical platform to use to achieve the best surgical outcome for TME. The emergence and technological progress of transanal total mesorectal excision (taTME) can solve the problem of difficulty in lower rectal resection and achieve better surgical resection results. Based on relevant literatures and combined with team clinical practice, the authors explore the technical advantages and oncological efficacy of taTME in rectal cancer.

Primer caso de escisión mesorrectal total transanal (TaTME) para el tratamiento del cáncer de recto medio en un centro docente universitario: descripción de la técnica / First case of transanal total mesorectal excision (TaTME) for middle rectal cancer in a teaching tertiary center: technical aspects / Primeiro caso de excisão total do mesorreto transanal (TaTME) para tratamento de câncer de reto meio em um centro universitário de ensino: aspectos tecnicos

La escisión mesorrectal transanal (TaTME: transanal total mesorectal escision) es la última de una larga lista de desarrollos técnicos y tecnológicos para el tratamiento del cáncer de recto medio y bajo. Incluso para los cirujanos colorrectales experimentados, lograr una escisión mesorrectal total (emt) de calidad en cirugía oncológica no siempre es sencillo, por la dificultad de obtener un adecuado acceso a la pelvis. Los estudios realizados han mostrado resultados comparables al abordaje laparoscópico, con tasas elevadas de escisiones mesorrectales completas y bajo porcentaje de margen circunferencial radial (CRM: circumferential radial margin) y distal positivos, con un adecuado número de ganglios resecados. Como toda técnica nueva, su implementación puede traer consecuencias no intencionales. La complejidad del abordaje, la dificultad en la identificación de nuevos repères y planos anatómicos, ha llevado a complicaciones graves como la lesión uretral o la siembra tumoral pelviana. Por ello, la comunidad quirúrgica ha retrasado la implementación masiva de la técnica y desarrollado estrategias de enseñanza y monitorización de este procedimiento para su realización en centros de alto volumen. El objetivo de esta publicación es presentar el primer caso de TaTME en un centro docente universitario y difundir en nuestra comunidad científica el fundamento de la técnica, sus indicaciones, describir los principales pasos técnicos, complicaciones, resultados oncológicos y funcionales.

Transanal total mesorectal excision (TaTME) is the last of a long list of technical and technological developments for treatment of middle and low rectal cancer. Even for skilled colorectal surgeons, achieving a good quality total mesorectal excision (TME) in oncology surgery is not always simple, due to the difficulty of obtaining optimal access to the pelvis. So far, studies have shown similar results to laparoscopic surgery, with high rates of complete mesorectal excisions and low rate of circumferential radial margin (CRM) and distal margin with an appropriate number of resected lymph nodes. Like every new technique, its implementation can bring unwanted consequences. The complexity of the approach, the difficulty in the identification of new landmarks and anatomic planes, has led to serious complications such as urethral injury or tumoral seeding. This has made slowdown the massive implementation of the technique among the surgical community, addressing the need of developing training programs and mentoring of this procedure that belongs to high volume centers. The aim of this publication is to present the first case of TaTME in a teaching tertiary center and spread, in our scientific community, the principles of the technique, its indications, main technical steps, complications and functional and oncologic results.

A excisão mesorretal transanal (TaTME: transanal total mesorectal escision) é o mais recente de uma longa linha de desenvolvimentos técnicos e tecnológicos para o tratamento do câncer retal inferior e médio. Mesmo para cirurgiões colorretais experientes, nem sempre é fácil obter uma excisão total do mesorreto (EMT) de qualidade em cirurgia de câncer, devido à dificuldade de obter acesso adequado à pelve. Os estudos realizados mostraram resultados comparáveis ​​à abordagem laparoscópica, com altas taxas de excisões completas do mesorreto e baixo percentual de margem radial circunferencial positiva (CRM: circumferential radial margin) e distal, com número adequado de linfonodos ressecados. Como qualquer nova técnica, sua implementação pode ter consequências não intencionais. A complexidade da abordagem, a dificuldade em identificar novos repères e planos anatômicos, levou a complicações graves, como lesão uretral ou semeadura de tumor pélvico. Por esse motivo, a comunidade cirúrgica atrasou a implementação massiva da técnica e desenvolveu estratégias de ensino e acompanhamento desse procedimento para sua realização em centros de alto volume. O objetivo desta publicação é apresentar o primeiro caso de TaTME em um centro de ensino universitário e divulgar em nossa comunidade científica as bases da técnica, suas indicações, descrever as principais etapas técnicas, complicações, resultados oncológicos e funcionais.

Actively participate in international high-quality clinical trials for improving the research level of colorectal surgery in China / 中华消化外科杂志

The number of colorectal cancer patients in China ranks the top in the world, but there are few international guidelines for the diagnosis and treatment of colorectal cancer formulated by Chinese, nor high-level evidence-based medicine research of colorectal cancer from China. Transanal total mesorectal excision (taTME) is a new technology in the field of colorectal surgery in recent years. At present, clinical practice related to taTME has been carried out simul-taneously with clinical researches in the world. Based on the experience of participating in the top clinical trials in the field of international colorectal surgery, like the COLOR series prospective research, the authors introduce the organization and implementation of COLOR Ⅲ research in China. It is hoped that the COLOR series trials will become an example in the field of high-quality surgical clinical research, so as to improve the clinical research level of colorectal surgery in China.

Current status of research on short-term urogenital function after transanal total mesorectal excision and laparoscopic total mesorectal excision / 中华胃肠外科杂志

Thanks to the new surgical approach, transanal total mesorectal excision (taTME) has a better operative field exposure than laparoscopic-assisted total mesorectal excision (laTME), especially for male patients with obesity, pelvic stenosis or prostate hypertrophy. Nevertheless, whether the urogenital function and quality of life after taTME are better as compared to laTME requires further study. According to the existing studies, taTME and laTME are not significantly different in symptoms of the urology system for male patients, but some large sample clinical studies show that the incidence of urethral mechanical injury after taTME is higher. Unfortunately, there is no elaboration on that for females. The sexual function of male patients after taTME and laTME is both impaired. The sexual function of male patients will be relieved to different degrees over time, but there is no significant difference. Compared with laTME, taTME shows advantages in the sexual function for female patients. There is no significant difference in short-term urogenital system function between taTME and laTME at present. As a new surgical approach, the impact on urogenital system function after taTME is acceptable. However, whether there is a significant difference in urogenital function between taTME and laTME needs further research. In addition, functional results still need comprehensive evaluation, and preoperative baseline evaluation also needs to be enhanced. The functional evaluation for male and female should be carried out separately rather than confused. Questionnaire for evaluation of functional results also needs to be verified.

Safety and prognosis analysis of transanal total mesorectal excision versus laparoscopic mesorectal excision for mid-low rectal cancer / 中华胃肠外科杂志

Objective: To compare the short-term and long-term outcomes between transanal total mesorectal excision (taTME) and laparoscopic total mesorectal excision (laTME) for mid-to-low rectal cancer and to evaluate the learning curve of taTME. Methods: This study was a retrospective cohort study. Firstly, consecutive patients undergoing total mesorectal excision who were registered in the prospective established database of Division of Colorectal Diseases, Department of General Surgery, Peking Union Medical College Hospital during July 2014 to June 2020 were recruited. The enrolled patients were divided into taTME and laTME group. The demographic data, clinical characteristics, neoadjuvant treatment, intraoperative and postoperative complications, pathological results and follow-up data were extracted from the database. The primary endpoint was the incidence of anastomotic leakage and the secondary endpoints included the 3-year disease-free survival (DFS) and the 3-year local recurrence rate. Independent t-test for comparison between groups of normally distributed measures; skewed measures were expressed as M (range). Categorical variables were expressed as examples (%) and the χ(2) or Fisher exact probability was used for comparison between groups. When comparing the incidence of anastomotic leakage, 5 variables including sex, BMI, clinical stage evaluated by MRI, distance from tumor to anal margin evaluated by MRI, and whether receiving neoadjuvant treatment were balanced by propensity score matching (PSM) to adjust confounders. Kaplan-Meier curve and Log-rank test were used to compare the DFS of two groups. Cox proportional hazard model was used to analyze and determine the independent risk factors affecting the DFS of patients with mid-low rectal cancer. Secondly, the data of consecutive patients undergoing taTME performed by the same surgical team (the trananal procedures were performed by the same main surgeon) from February 2017 to March 2021 were separately extracted and analyzed. The multidimensional cumulative sum (CUSUM) control chart was used to draw the learning curve of taTME. The outcomes of 'mature' taTME cases through learning curve were compared with laTME cases and the independent risk factors of DFS of 'mature' cases were also analyzed. Results: Two hundred and forty-three patients were eventually enrolled, including 182 undergoing laTME and 61 undergoing taTME. After PSM, both fifty-two patients were in laTME group and taTME group respectively, and patients of these two groups had comparable characteristics in sex, age, BMI, clinical tumor stage, distance from tumor to anal margin by MRI, mesorectal fasciae (MRF) and extramural vascular invasion (EMVI) by MRI and proportion of receiving neoadjuvant treatment. After PSM, as compared to laTME group, taTME group showed significantly longer operation time [(198.4±58.3) min vs. (147.9±47.3) min, t=-4.321, P<0.001], higher ratio of blood loss >100 ml during surgery [17.3% (9/52) vs. 0, P=0.003], higher incidence of anastomotic leakage [26.9% (14/52) vs. 3.8% (2/52), χ(2)=10.636, P=0.001] and higher morbidity of overall postoperative complications [55.8%(29/52) vs. 19.2% (10/52), χ(2)=14.810, P<0.001]. Total harvested lymph nodes and circumferential resection margin involvement were comparable between two groups (both P>0.05). The median follow-up for the whole group was 24 (1 to 72) months, with 4 cases lost, giving a follow-up rate of 98.4% (239/243). The laTME group had significantly better 3-year DFS than taTME group (83.9% vs. 73.0%, P=0.019), while the 3-year local recurrence rate was similar in two groups (1.7% vs. 3.6%, P=0.420). Multivariate analysis showed that and taTME surgery (HR=3.202, 95%CI: 1.592-6.441, P=0.001) the postoperative pathological staging of UICC stage II (HR=13.862, 95%CI:1.810-106.150, P=0.011), stage III (HR=8.705, 95%CI: 1.104-68.670, P=0.040) were independent risk factors for 3-year DFS. Analysis of taTME learning curve revealed that surgeons would cross over the learning stage after performing 28 cases. To compare the two groups excluding the cases within the learning stage, there was no significant difference between two groups after PSM no matter in the incidence of anastomotic leakage [taTME: 6.7%(1/15); laTME: 5.3% (2/38), P=1.000] or overall complications [taTME: 33.3%(5/15), laTME: 26.3%(10/38), P=0.737]. The taTME was still an independent risk factor of 3-year DFS only analyzing patients crossing over the learning stage (HR=5.351, 95%CI:1.666-17.192, P=0.005), and whether crossing over the learning stage was not the independent risk factor of 3-year DFS for mid-low rectal cancer patients undergoing taTME (HR=0.954, 95%CI:0.227-4.017, P=0.949). Conclusions: Compared with conventional laTME, taTME may increase the risk of anastomotic leakage and compromise the oncological outcomes. Performing taTME within the learning stage may significantly increase the risk of postoperative anastomotic leakage.

Short-term complications after transanal total mesorectal excision for mid-low rectal cancer / 中华胃肠外科杂志

Objective: To summarize short-term postoperative complications of transanal total mesorectal excision (taTME) in the treatment of middle-low rectal cancer. Methods: A descriptive case series of cases was constructed. Clinical data of consecutive 83 patients with mid-low rectal cancer who received taTME treatment from November 2016 to April 2021 at Department of General Surgery of Beijing Friendship Hospital, Capital Medical University were collected. Among 83 patients, 58 (69.9%) were males, with a mean age of (61.4±11.8) years; 42 (50.6%) were low rectal cancer, 41 (49.4%) were middle rectal cancer. Short-term postoperative complication was defined as complication occurring within 30 days after operation. The complication was graded according to the Clavien-Dindo classification. At the same time, the morbidity of short-term postoperative complication in the first 40 patients and that in the last 43 patients were compared to understand the differences before and after passing the taTME learning curve. Results: Two patients (2.5%) were converted to laparotomy ; 78 (94.0%) completed anastomosis.While 5 (6.0%) underwent permanent stoma. The total operation time of transabdominal+ transanal procedure was (246.9±85.0) minutes, and the median intraoperative blood loss was 100 (IQR: 100) ml. Seventy-five cases (75 /78, 96.2%) underwent defunctioning stoma, including 74 cases of diverting ileostomy, 1 case of diverting transverse colostomy and 3 cases without stoma. The morbidity of complication within 30 days after operation was 38.6% (32/83), and the morbidity of complication after discharge was 8.4% (7/83). Minor complications accounted for 31.3% (26/83) and major complications accounted for 7.2% (6/83). No patient died within 30 days after operation. The incidence of anastomotic leakage was 15.4% (12/78). Eight patients (9.6%) were hospitalized again due to complications after discharge. The median postoperative hospital stay was 7 (IQR: 3) days. All the patients with minor (I-II) complications received conservative treatment. One patient with grade C anastomotic leakage was transferred to intensive care unit and received a second operation due to sepsis and multiple organ dysfunction. Two patients with paralytic ileus (Clavien-Dindo IIIa) underwent endoscopic ileus catheter placement. There were 3 patients with Clavien-Dindo III or above respiratory complications, including 1 patient with pleural effusion and ultrasound-guided puncture, 2 patients with respiratory failure who were improved and discharged after anti-infection and symptomatic treatment. One patient underwent emergency ureteral stent implantation due to urinary infection (Clavien-Dindo IIIb). The morbidity of postoperative complication in the first 40 cases was 50.0% (20/40), and that in the latter 43 cases decreased significantly (27.9%, 12/43), whose difference was statistically significant (χ(2)=4.270, P=0.039). Conclusions: The procedure of taTME has an acceptable morbidity of short-term postoperative complication in the treatment of mid-low rectal cancer. The accumulation of surgical experience plays an important role in reducing the morbidity of postoperative complication.

Quality indicators of transanal total mesorectal excision (TaTME) for rectal cancer

Introduction: Transanal total mesorectal excision (TaTME) has revolutionized the surgical techniques for lower-third rectal cancer. The aim of the present study was to analyze the outcomes of quality indicators of TaTME for rectal cancer compared with laparoscopic TME (LaTME). Methods: A cohort prospective study with 50 (14 female and 36male) patients, with a mean age of 67 (range: 55.75 to 75.25) years, who underwent surgery for rectal cancer. In total, 20 patients underwent TaTME, and 30, LaTME. Every TaTME procedure was performed by experienced colorectal surgeons. The sample was divided into two groups (TaTME and LaTME), and the quality indicators of the surgery for rectal cancer were analyzed. Results: There were no statistically significant differences regarding the patients and the main characteristics of the tumor (age, gender, American Society of Anesthesiologists [ASA] score, body mass index [BMI], tumoral stage, neoadjuvant therapy, and distance from the tumor to the external anal margin) between the two groups. The rates of: postoperativemorbidity (TaTME: 35%; LaTME: 30%; p=0.763);mortality (0%); anastomotic leak (TaTME: 10%; LaTME: 13%; p=0.722); wound infection (TaTME: 0%; LaTME: 3.3%; p=0.409); reoperation (TaTME: 5%; LaTME: 6.6%; p=0.808); and readmission (TaTME: 5%; LaTME: 0%; p=0.400), as well as the length of the hospital stay (TaTME: 13.5 days; LaTME: 11 days; p=0.538), were similar in both groups. There were no statistically significant differences in the rates of positive circumferential resection margin (TaTME: 5%; LaTME: 3.3%; p=0.989) and positive distal resection margin (TaTME: 0%; LaTME: 3.3%; p=0.400), the completeness of the TME (TaTME: 100%; LaTME: 100%), and the number of lymph nodes harvested (TaTME: 15; LaTME: 15.5; p=0.882) between two groups. Conclusion: Transanal total mesorectal excision is a safe and feasible surgical procedure for middle/lower-third rectal cancer. (AU)

Perirectal fascial anatomy and pelvic autonomic nerve preservation during the transanal total mesorectal excision / 中华胃肠外科杂志

The difficulty of transanal total mesorectal excision (TME) is to find the correct dissection plane of perirectal space. As a complex new surgical procedure, the fascial anatomic landmarks of transanal approach operation are more likely to be ignored. It is often found that dissection plane is false after the secondary injury occurs during the operation, which results in the damage of pelvic autonomic nerves. Meanwhile, the mesorectum is easily damaged if the dissection plane is too close to the rectum. Thus, the safety of oncologic outcomes could be limited by difficulty achieving adequate TME quality. The promotion and development of the theory of perirectal fascial anatomy provides a new thought for researchers to design a precise approach for transanal endoscopic surgery. Transanal total mesorectal excision based on fascial anatomy offers a solution to identify the transanal anatomic landmarks precisely and achieves pelvic autonomic nerve preservation. In this paper, the authors focus on the surgical experience of transanal total mesorectal excision based on the theory of perirectal fascial anatomy, and discuss the feature of perirectal fascial anatomy dissection and technique of pelvic autonomic nerve preservation during transanal approach operation.

Efficacy of transanal hand-sewn reinforcement in low rectal stapled anastomosis in preventing anastomotic leak after transanal total mesorectal excision / 中华胃肠外科杂志

Objective: To explore the efficacy and feasibility of transanal hand-sewn reinforcement of low stapled anastomosis in preventing anastomotic leak after transanal total mesorectal excision (taTME). Methods: A descriptive cohort study was conducted. Clinical data of 51 patients with rectal cancer who underwent taTME with transanal hand-sewn reinforcement of low stapled anastomosis at Department of Colorectal Surgery, the Sixth Affiliated Hospital of Sun Yat-sen University from January 2019 to December 2020 were retrospectively collected. Inclusion criteria: (1) age >18 years old; (2) rectal cancer confirmed by preoperative pathology; (3) distance from tumor to anal verge ≤ 8 cm according to pelvic MR; (4) the lesion was evaluated to be resectable before operation; (5) with or without neoadjuvant chemotherapy and radiotherapy; (6) taTME, end-to-end stapled anastomosis, and reinforcement in the anastomosis with absorbable thread intermittently were performed, and the distance between anastomosis and anal verge was ≤ 5 cm. Exclusion criteria: (1) previous history of colorectal cancer surgery; (2) emergency surgery due to intestinal obstruction, bleeding or perforation; (3) patients with local recurrence or distant metastasis; (4) the period of postoperative follow-up less than 3 months. The procedure of transanal hand-sewn reinforcement was as follows: firstly, no sign of bleeding was confirmed after checking the anastomosis. Then, the anastomosis was reinforced by suturing the muscle layer of rectum intermittently in a figure-of-eight manner using 3-0 single Vicryl. The entry site of the next suture was close next to the exit site of the last one. Any weak point of the anastomosis could also be reinforced according to the specimen from the circular stapler. The primary outcome were the incidence of anastomotic leak, methods of the secondary operation, anastomotic infection, anastomotic stricture, and conditions of Intraoperative and postoperative. Results: All the 51 enrolled patients completed surgery successfully without any conversion to open surgery. The median operative time was 169 (109-337) minutes, and the median intraoperative blood loss was 50 (10-600) ml. The median postoperative hospital stay was 8 (5-16) days. The mssorectum was complete and distal resection margin was negative in all patients. Postive circumferential resection margin was observed in 1 patients (2.0%). Twelve (23.5%) patients underwent prophylactic ileostomy. One patient developed anastomosis stricture which was cured by digital dilatation of the anastomosis. ISREC grade C anastomotic leak was observed in 3 (5.9%) male patients, of whom 2 cases did not received prophylactic ileostomy during the operation, and were cured by a second operation with the ileostomy and anastomotic repair. The other one healed by transanal repair of the anastomosis and anti-infection therapy. One (2.0%) patient suffered from perianal infection and healed by sitz bath and anti-infection therapy. No death was reported within 30 days after operation. Conclusion: Transanal hand-sewn reinforcement in low rectal stapled anastomosis in preventing anastomotic leak after taTME is safe and feasible.

Incidence and risk factors of anastomotic leak after transanal total mesorectal excision in China: a retrospective analysis based on national database / 中华胃肠外科杂志

Objective: Transanal total mesorectal excision (taTME) was a very hot topic in the first few years since its appearance, but now more introspections and controversies on this procedure have emerged. One of the reasons why the Norwegian Ministry of Health stopped taTME was the high incidence of postoperative anastomotic leak. In current study, the incidence and risk factors of anastomotic leak after taTME were analyzed based on the data registered in the Chinese taTME Registry Collaborative (CTRC). Methods: A case-control study was carried out. Between November 15, 2017 and December 31, 2020, clinical data of 1668 patients undergoing taTME procedure registered in the CTRC database from 43 domestic centers were collected retrospectively. After excluding 98 cases without anastomosis and 109 cases without complete postoperative complication data, 1461 patients were finally enrolled for analysis. There were 1036 males (70.9%) and 425 females (29.1%) with mean age of (58.2±15.6) years and mean body mass index of (23.6±3.8) kg/m(2). Anastomotic leak was diagnosed and classified according to the International Study Group of Rectal Cancer (ISREC) criteria. The risk factors associated with postoperative anastomotic leak cases were analyzed. The impact of the cumulative number of taTME surgeries in a single center on the incidence of anastomotic leak was evaluated. As for those centers with the number of taTME surgery ≥ 40 cases, incidence of anastomic leak between 20 cases of taTME surgery in the early and later phases was compared. Results: Of 1461 patients undergoing taTME, 103(7.0%) developed anastomotic leak, including 71 (68.9%) males and 32 (31.1%) females with mean age of (59.0±13.9) years and mean body mass index of (24.5±5.7) kg/m(2). The mean distance between anastomosis site and anal verge was (2.6±1.4) cm. Thirty-nine cases (37.9%) were classified as ISREC grade A, 30 cases (29.1%) as grade B and 34 cases (33.0%) as grade C. Anastomotic leak occurred in 89 cases (7.0%,89/1263) in the laparoscopic taTME group and 14 cases (7.1%, 14/198) in the pure taTME group. Multivariate analysis showed that hand-sewn anastomosis (P=0.004) and the absence of defunctioning stoma (P=0.013) were independently associated with anastomotic leak after taTME. In the 16 centers (37.2%) which performed ≥ 30 taTME surgeries with cumulative number of 1317 taTME surgeries, 86 cases developed anastomotic leak (6.5%, 86/1317). And in the 27 centers which performed less than 30 taTME surgeries with cumulative number of 144 taTME surgeries, 17 cases developed anastomotic leak (11.8%, 17/144). There was significant difference between two kinds of center (χ(2)=5.513, P=0.019). Thirteen centers performed ≥ 40 taTME surgeries. In the early phase (the first 20 cases in each center), 29 cases (11.2%, 29/260) developed anastomotic leak, and in the later phase, 12 cases (4.6%, 12/260) developed anastomotic leak. The difference between the early phase and the later phase was statistically significant (χ(2)=7.652, P=0.006). Conclusion: The incidence of anastomotic leak after taTME may be reduced by using stapler and defunctioning stoma, or by accumulating experience.

Interpretation of international expert consensus guidance on indications, implementation and quality measures for transanal total mesorectal excision / 中华胃肠外科杂志

In recent years, transanal total mesorectal excision (taTME) has been a hot spot in the field of colorectal surgery. Compared with the traditional laparoscopic technique, taTME has potential advantages in the treatment of rectal diseases. However, the procedural safety and effectiveness of taTME need further verification. In order to ensure the safe and standardized implementation of this procedure, the European Society of Coloproctology, together with 14 international academic organizations related to colorectal surgery and minimally invasive surgery, has developed the international expert consensus guidance on indications, implementation and quality measures for taTME. This paper introduces the background of the international consensus guidance, and interprets its core contents, including the surgical indications (complex pelvic conditions, malignant and benign rectal diseases), surgical quality and outcome evaluation, structured training, and expert center. It is expected to provide reference and guidance for Chinese colorectal surgery colleagues performing taTME.

Technical points of 4K laparoscopic assisted transanal total mesorectal excision / 中华消化外科杂志

Surgical treatment of low rectal cancer is a difficult point in colorectal surgery, which has the problem of mutual restriction between radical resection and functional protection. With the development of laparoscopic total mesenterectomy, minimally invasive operation through anal endoscopy and the gradual improvement of the concept of natural orifice transluminal endoscopic surgery, the transanal total mesorectal excision (taTME) is formed in line with the principle of radical resection of rectal cancer. On the premise of ensuring radical resection, taTME can maximize organ preservation and function protection, and improve the quality of life of patients. 4K laparoscopic system can provide a clear surgical field and improve the surgical precision, which is helpful for the accurate anatomy of low rectal cancer. The authors share the clinical experience of 4K laparoscopy assisted taTME in order to provide references for surgical colleagues.

Short term efficacy of laparoscopic assisted transanal total mesorectal excision for low rectal cancer: a prospective, multicenter, case registration study / 中华消化外科杂志

Objective:To investigate the short term efficacy of laparoscopic assisted transanal total mesorectal excision (taTME) for low rectal cancer.Methods:The prospective study was conducted. The clinicopathological data of 80 patients who underwent laparoscopic assisted taTME for low rectal cancer in 8 medical centers，including 27 cases in the First Affiliated Hospital of Jilin University，16 cases in the Daping Hospital of Army Medical University，15 cases in the Beijing Friendship Hospital of Capital Medical University，10 cases in the Peking University Cancer Hospital，7 cases in the Peking Union Medical College Hospital of Chinese Academy of Medical Sciences，2 cases in the Peking University People′s Hospital，2 cases in the Liaoning Cancer Hospital Institute，1 case in the Ruijin Hospital of Shanghai Jiaotong University School of Medicine，from August 2017 to September 2018 were collected. Observation indicators：(1) clinical data of enrolled patients；(2) surgical situations；(3) postoperative histopathological examination；(4)postoperative complications and hospitalization. Measurement data with skewed distribution were represented as M(range). Count data were described as absolute numbers and (or) percentages. Results:(1) Clinical data of enrolled patients：a total of 80 patients were selected for eligibility. There were 59 males and 21 females，aged from 53 to 79 years，with a median age of 61 years. (2）Surgical situations：all 80 patients underwent surgery successfully，including 73 cases undergoing low anterior resection，4 cases undergoing Hartmann operation，1 case undergoing intersphincteric and abdominoperineal resection，1 case undergoing other operations and 1 case missing operation information. Nineteen of the 80 patients underwent transabdominal and transanal operations simultaneously. The operation time of 80 patients was 255 minutes (range，211?305 minutes). Of 80 patients，77 cases had the volume of intraoperative blood loss ≤500 mL，3 cases had the volume of intraoperative blood loss >500 mL，44 cases underwent instrumental anastomosis，24 cases underwent manual anastomosis，12 cases were missing anastomosis information，66 cases had specimens been taken out through anus，2 cases had specimens been taken out through Pfannens-tiel incision，10 cases had specimens been taken out through other ways，2 cases were missing the information of specimens removal ways，57 cases underwent preventive stoma，32 cases under-went anal canal indwelling，30 cases underwent free of splenic flexure and 2 cases were converted to open surgery. (3) Postoperative histopathological examination：of 80 patients，68 cases had the integrity of mesorectal specimens with complete，5 cases had the integrity of mesorectal specimens with near complete，1 case had the integrity of mesorectal specimens with not complete，6 cases were missing the information of integrity of mesorectal specimens，1 case had rectal perforation，1 case had positive circumferential margin and 1 case had positive distal margin. The number of lymph node dissected and diameter of tumor were 12(range，9?16) and 3.0 cm(range，1.9?4.0 cm) of 80 patients. Four of 80 patients achieved pathological complete remission. Cases with tumor stage as T0 stage，Tis stage，T1 stage，T2 stage，T3 stage or T4 stage of the pT staging，cases with tumor stage as N0 stage，N1 stage or N2 stage of the pN staging，cases with tumor stage as M0 stage or M1 stage of the pM staging were 4，2，11，24，35，4，55，21，4，75，5 of 80 patients. (4) Postopera-tive complications and hospitalization：8 of 80 patients underwent anastomotic leakage，including 2 cases with grade A anastomotic leakage，4 cases with grade B anastomotic leakage and 2 cases with grade C anastomotic leakage.Seven of 80 patients underwent intestinal obstruction. The 2 cases with grade A anastomotic leakage were improved after symptomatic drug treatment，the 4 cases with grade B anastomotic leakage were improved after treatment with antibiotics or catheter drainage and the 2 cases with grade C anastomotic leakage were improved after operation. The duration of hospital stay of 80 patients was 14 days(range，11?21 days). No patient died during hospitalization.Conclusion:Laparoscopic assisted taTME for low rectal cancer is safe and feasible，which has a good short term efficacy.

Application value of multidisciplinary team model in normatively carrying out transanal total mesorectal excision / 中华消化外科杂志

With certain advantages of superior surgical fields and better chances for anus reservation,transanal total mesorectal excision (TaTME) is a novel surgical approach for low rectal cancer.Guidelines recommend muhidisciplinary team (MDT) work as a clinical routine for standardized treatment of rectal cancer.Indication of TaTME depends on multidisciplinary discussion including preoperative staging,prediction of recurrence risks.Standardized preoperative evaluation by MDT and decisions after MDT discussion are the guarantee for the startdardized implementation and reasonable promotion of TaTME.Meanwhile,as a procedure for improving local efficacy of rectal cancer,TaTME could save a part of patients with low rectal cancer the trouble of neoadjuvant chemoradiotherapy based on accurate staging by radiologists.That might upgrade status of colorectal.surgeons in the MDT and contribute to optimize both curative effects and health economics.

Application value of multidisciplinary team model in normatively carrying out transanal total mesorectal excision / 中华消化外科杂志

With certain advantages of superior surgical fields and better chances for anus reservation, transanal total mesorectal excision (TaTME) is a novel surgical approach for low rectal cancer. Guidelines recommend multidisciplinary team (MDT) work as a clinical routine for standardized treatment of rectal cancer. Indication of TaTME depends on multidisciplinary discussion including preoperative staging, prediction of recurrence risks. Standardized preoperative evaluation by MDT and decisions after MDT discussion are the guarantee for the stan-dardized implementation and reasonable promotion of TaTME. Meanwhile, as a procedure for improving local efficacy of rectal cancer, TaTME could save a part of patients with low rectal cancer the trouble of neoadjuvant chemoradiotherapy based on accurate staging by radiologists. That might upgrade status of colorectal surgeons in the MDT and contribute to optimize both curative effects and health economics.

A combination treatment of transanal total mesorectal excision and Turnbull-Cutait abdominoperineal pull-through procedure for a low rectal cancer

ABSTRACT Surgical treatment for low rectal cancer has changed dramatically during the preceding several decades, and the optimal surgical approach remains incompletely developed. Transanal total mesorectal excision is likely the most promising approach for the dissection of the distal part of the mesorectum in a manner that allows for a technically easy and oncologically safe operation. Long after it was first described, the Turnbull-Cutait abdominoperineal pull-through procedure has recently been reintroduced in surgical practice for the treatment of patients with complex anorectal conditions. The current report describes a case of distal rectal cancer involving successful surgical treatment with a combination of the two aforementioned methods and patient discharge without a diverting stoma.

RESUMO tratamento cirúrgico para o câncer de reto baixo mudou drásticamente durante as últimas décadas, mas uma abordagem cirúrgica de excelência ainda continua incompletamente desenvolvida. A excisão total do mesorreto por via transanal parece ser a abordagem mais promissora para a dissecção da parte distal do mesorreto de forma a assegurar uma cirurgia oncológicamente segura com uma técnica simples. Muito depois de sua descrição, o pull-through abdominoperineal de Turnbull-Cutait tem sido reintroduzido na prática cirúrgica para o tratamento de pacientes com enfermidades anorretais complexas. Este relato descreve um caso de câncer de reto baixo que se beneficiou de um tratamento cirúrgico bem sucedido a partir da combinação das duas técnicas supracitadas com o paciente recebendo alta hospitalar sem ostomia de proteção.

Problem of the carbon dioxide embolism during the procedure of transanal total mesorectal excision / 中华胃肠外科杂志

Carbon dioxide embolization is a special complication of laparoscopic colorectal surgery. It is rarely reported in conventional laparoscopic colorectal surgery, and has not been well recognized by surgeons. Transanal total mesorectal excision (taTME) is an increasingly popular sphincter-preserving surgery for low rectal cancer in recent years. Although the number of cases worldwide is not large, carbon dioxide embolization after operation has been reported successively. Once serious carbon dioxide embolization occurs, the mortality is extremely high. The main related factors of carbon dioxide embolization in taTME include high pressure of pneumoperitoneum, narrow space, abundant blood supply of prostate and vaginal wall, Trendelenburg position, etc. The key of prevention and treatment is to pay attention to the control of related risk factors, identify the early signs of carbon dioxide embolism, and take active and effective symptomatic treatment. Reducing the pressure of pneumoperitoneum perfusion can reduce the occurrence of CO2 embolism. Transesophageal echocardiography is the most sensitive way to monitor intravenously CO2, but it is difficult to carry out in clinical practice. The sudden decrease of end expiratory CO2 partial pressure is an important sign of early detection of CO2 embolism. If there is a suspicious lacuna in the operation, it is possible to reduce or stop the pneumoperitoneum when it is unable to distinguish between normal tissue gap or vascular lumen. If the "bubble sign" is observed, CO2 may enter the vein. The risk of venous embolism should be considered.

Mechanism and anatomy recognition of neurovascular bundle injury from different perspectives of transabdominal and transanal approach / 中华胃肠外科杂志

The neurovascular bundle (NVB) starts at the lateral angle of the seminal vesicle (the initial part), passes posterolateral of the prostate gland (the main part), and ends at the cavernous body of the penis (the cavernous part). In low rectal surgery, different transabdominal and transanal perspectives result in different NVB injury risks. In the perspective of transabdominal operation, the separation between the initial part of NVB and Denonvilliers fascia and the anatomical variation of the two lateral sides of Denonvilliers fascia increases the risk of NVB injury, and conformation separation may take into account the convenience of separationand the protection of NVB. In the perspective of transanal operation, when separating the main part with NVB and mesorectum, the perspective of the transanal, unidirection traction and excessive dissection increase the risk of NVB main exposure. Clear anatomical identification helps the protection of NVB in the transanal operation. At present, the medical evidence on the difference of NVB injury in different perspectives of transabdominal and transanal approach is still in need of relevant clinical researches.

Transanal lateral lymph node dissection surgery for 5 cases of mid-low rectal cancer / 中华胃肠外科杂志

Objective@#To evaluate the feasibility and safety of transanal lateral lymph node dissection for mid-low rectal cancer.@*Methods@#A descriptive case series research method was used. Clinical and pathological data of 5 mid-low rectal cancer patients who underwent transanal lateral lymph node dissection at Department of Colorectal Surgery, the Sixth Affiliated Hospital of Sun Yat-sen University from November 2018 to May 2019 were retrospectively collected and analyzed. Of 5 cases, 4 were male and 1 was female with mean age of (43.2±13.2) years and mean body mass index of (21.2±2.6) kg/m2; the mean diameter of tumor was (3.2±2.4) cm; the mean distance between tumor and anus was (6.3±2.5) cm; 3 received preoperative neoadjuvant chemotherapy. In preoperative TNM staging, 2 cases were T3N1M0, 1 was T3cN2aM0, 1 was T3cN2bM0, and 1 was T2N1M0. All the patients had no intestinal obstruction before operation. Surgical methods: (1) total mesorectal excision: using general transanal and transabdominal methods to mobilize and resect total mesorectum, and dissect No.252, No.253 lymph nodes; (2) transanal lateral lymph node dissection: dissect the adipose lymphoid tissue on the surface of the iliococcygeal muscle, the coccygeal muscle, and the obturator muscle (the No.283 lymph nodes) upward, and dissect No.263d and No.263p lymph nodes with fat tissue sequentially till the bifurcation of the internal and external iliac artery; (3) take out the specimen from anus, and make anastomosis between proximal colon and anal canal. Intraoperative and postoperative variables was observed.@*Results@#All the 5 patients completed surgery successfully, and no patient needed to convert to open approach. The mean operative time was (295.6±97.7) minutes, and the median intraoperative blood loss was 70 (50-500) ml. The mean length of specimen was (12.9±3.0) cm, and the mean number of harvested lymph node was 30.4±9.9. The positive lateral lymph nodes were founder in 4 patients. The median distance between tumor and distal resection margin was 1.5 (1.2-8.0) cm. The resection margin in all the patients was negative. The mean time to postoperative flatus was (4.2±1.6) days, the mean postoperative spontaneous urination was (3.0±1.9) days, time to drainage tube removal was (5.6±1.9) days, and the mean postoperative hospital stay was (9.4±2.1) days. The postoperative TNM staging by pathology was 1 case with T1N0M0, 1 with T2N1M0, 1 with T3N2bM0, and 2 with T3N2M0. Five patients were moderately differentiated adenocarcinoma. Only 1 patient developed postoperative abdominal bleeding, who was healed after conservative treatment. The other 4 patients did not develop any perioperative complications, such as incision infection, presacral abscess, pelvic abscess, anastomotic leakage, or anastomotic stricture. Four patients underwent postoperative chemotherapy. All the patients were followed up for 2 to 28 weeks after surgery and they all felt well. The patients with stoma had fluent bowel.@*Conclusions@#Transanal lateral lymph node dissection is feasible and safe in the treatment of mid-low rectal cancer, which can achieve the purpose of extended radical resection of mid-low movement rectal cancer. Moreover, this procedure is a new method to treat rectal cancer patients with lateral lymph node metastasis.