Research progress in predicting the difficulty of surgery for middle and low rectal cancer based on pelvic measurement / 中华消化外科杂志

Total mesorectal excision (TME) has become the basic principle of surgical treat-ment for middle and low rectal cancer. Some of patients with ultra-low rectal cancer require under-going intersphincteric resection (ISR). Due to the limitation of the narrow pelvis, TME and ISR put forward higher requirements for the precise separation of the anatomical level and the protection of neurological function during the operation. At present, evaluation of the difficulty of surgery for middle and low rectal cancer is mainly based on the subjective judgment of chief surgeon, and there is no unified and objective scoring system or prediction model that can classify the difficulty of surgery for middle and low rectal cancer before surgery. The authors review relevant literatures and summarize the existing studies related to pelvic measurement for predicting the difficulty of surgery for middle and low rectal cancer, in order to provide significant guidance for the selection of surgical approach for patients with middle and low rectal cancer.

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.

Difficulties and strategies of total mesorectal excision for middle and low rectal cancer after neoadjuvant therapy / 中华消化外科杂志

Patients with local advanced rectal cancer (LARC) can benefit from neoadju-vant chemoradiotherapy (nCRT) of reducing local recurrence rate and improving survival rate. However, tissue edema after nCRT may lead to unclear tissue spaces, making it challenging for lymph node dissection and nervous system protection. The difficulty in locating inferior margin of tumor after clinical complete remission or closing to clinical complete remission, as well as the increasing risk of anastomotic leakage after nCRT, pose difficulties and new challenges of total mesorectal excision for middle and low rectal cancer. Based on literatures and clinical experiences, the authors summarize the difficulties and strategies of total mesorectal excision after nCRT, in order to provide reference for colleagues.

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.

Câncer de reto: qual a melhor técnica para excisão total do mesorreto laparoscópica ou robótica? / Rectum cancer: which is the best technique for total excision of the mesorectum laparoscopic or robotic?

Introdução: As operações laparoscópicas, assistidas por robô e a abertas são técnicas cirúrgicas comumente utilizadas na vida diária. A viabilidade e os resultados em curto e longo prazos dos procedimentos laparoscópicos e robóticos têm sido amplamente relatados. Objetivos: Comparar os dados clínicos e oncológicos da cirurgia assistida por robô e laparoscópica no câncer retal. Métodos: Foram pesquisados o Pubmed/Medline, Embase, e Cochrane Library para artigos relevantes publicados até 2021. Estudos baseados na comparabilidade entre operação assistida por robô e laparoscópica para câncer retal foram designados. Os parâmetros analisados incluíram tempo operatório, conversão para procedimento aberto, perda estimada de sangue, tempo de recuperação da função intestinal, tempo de internação, vazamento da anastomose e complicações pós-operatórias. Resultados: Operação assistida por robô foi associada com maior tempo operatório (342 vs.192 min na cirurgia laparoscópica, p<0,001), menor conversão para procedimento aberto, menor tempo de internação hospitalar e recuperação mais rápida da função intestinal, menores complicações pós-operatórias de forma significativa (p=0,041). A perda estimada de sangue, a taxa de vazamento da anastomose e os resultados oncológicos, incluindo o número de linfonodos extraídos, não mostraram diferenças significativas entre os grupos. Conclusão: A cirurgia assistida por robô para câncer retal mostrou maior tempo operatório, menor conversão, taxas de recuperação da função intestinal mais rápidas e menor permanência no hospital. Seus resultados oncológicos forram semelhantes à cirurgia laparoscópica.

Introduction: Laparoscopic surgery, robot-assisted surgery and open surgery are the most commonly used surgical techniques in daily living. The feasibility and short- and long-term results of laparoscopic and robotic procedures have been widely reported. Objectives: To compare the clinical and oncological results of robot-assisted and laparoscopic surgery for rectal cancer. Methods: PubMed/Medline, Embase, The Cochrane Library were searched for relevant articles published until 2021. Studies based on comparability between robot-assisted and laparoscopic surgery for rectal cancer were designed. The parameters analyzed included operative time, conversion to open surgery, estimated blood loss, bowel function recovery time, length of hospital stay, anastomosis leak, and postoperative complications. Results: The robot-assisted surgery group was associated with longer operative time (342 vs. 192 min in laparoscopic surgery,p <0.001), lower conversion to open surgery, shorter length of hospital stay, faster bowel function recovery and lower postoperative complications significantly (p=0.041). Estimated blood loss, anastomosis leak rate, and oncological outcomes including the number of lymph nodes extracted showed no significant differences between groups. Conclusion: Robot-assisted surgery for rectal cancer showed longer operative time, lower conversion, faster bowel function recovery rates, shorter hospital stay, and similar oncological outcomes compared to laparoscopic surgery.

Scarless two-stage delayed coloanal anastomosis: a technique description

Introduction: In current clinical practice, immediate coloanal anastomosis (ICA) remains the standard technique for restoring the gastrointestinal tract following coloproctectomy for low rectal cancer. This anastomosis still requires a temporary diverting stoma to decrease the postoperative morbidity, which remains significantly high. As an alternative, some authors have proposed a two-stage delayed coloanal anastomosis (TS-DCA). This article reports on the surgical technique of TS-DCA. Methods: The case described is of a 53-year-old woman, without any particular history, in whom colonoscopy motivated by rectal bleeding revealed an adenocarcinoma of the low rectum. Magnetic resonance imaging showed a tumor ~ 1 cm above the puborectalis muscle, graded cT3N +. The extension workup was negative. Seven weeks after chemoradiotherapy, a coloproctectomy with total mesorectal excision (TME) was performed. A TS-DCA was chosen to restore the digestive tract. Conclusion: Two-stage delayed coloanal anastomosis is a safe and effective alternative for restoring the digestive tract after proctectomy for low rectal cancer. Recent data seem to show a clear advantage of this technique in terms of morbidity. (AU)

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.

Anatomical observation and clinical significance of the prostatic part of neurovascular bundle in total mesorectal excision / 中华胃肠外科杂志

Objective: To observe the anatomical architecture of the prostatic part of the neurovascular bundle (NVB) in total mesorectal excision (TME). Methods: A descriptive cohort study and an anatomical observation study were carried out. A total of 38 male patients with rectal cancer who underwent TME in the Department of Colorectal Surgery at the affiliated Union hospital of Fujian Medical University between November 2013 and March 2015 were included. A total of 4 hemipelvis were examined at the Laboratory of Clinical Applied Anatomy, Fujian Medical University. The following outcomes were observed: 1) the clinical significance of bleeding of the prostatic part of NVB: surgical videos were reviewed and the incidence of bleeding was recorded. The urogenital function was assessed using the International Prostate Symptom Score (IPSS) and International Index of Erectile Function (IIEF) score. The correlation between prostatic part bleeding and postoperative urogenital function was evaluated. 2) anatomical observation: the vessels, nerve fibers, as well as their surrounding fatty tissue from the prostatic part were treated as a whole, namely, the fat pad of the prostatic part. The anatomical architecture of the prostatic part in the surgical videos was reviewed and interpreted with the cadaveric findings. Categorical variables were compared between groups using a Fisher exact probability. while continuous variables with skewed distribution were compared between groups using the Mann-Whiteny U test. Results: The median age of the included 38 patients was 57 years (range, 31-75), and the median tumor distance to the anal verge was 6 cm (range, 1-8). Of them, a total number of 21 (55.3%) patients had bleeding of the prostatic part of NVB (bleeding group), while the rest had not (17 cases, 44.7%, non-bleeding group). 1) the clinical significance of bleeding of the prostatic part of NVB. The urinary function significantly decreased in patients in the bleeding group according to IPSS score after the 3rd month and the 6rd month of the surgery [7 (0-16) vs. 2 (0-3), Z=-1.787, P=0.088; 2 (0-15) vs. 0 (0-2), Z=-2.270, P=0.028]. There was no difference regarding the IPSS score between the two groups after 1 year of the surgery (P>0.05). With a total of 23 patients with normal preoperative sexual activity included, 87.5% (7/8) of patients in the non-bleeding group can expect to return to their preoperative baseline, this incidence was significantly higher than that of only 40% (6/15) in the bleeding group (P=0.029). 2) anatomical observation: for cadaveric observation, the prostatic part of NVB was located in the narrow triangular space composed of anterolateral walls of the rectum, the posterolateral surface of the prostate and the medial surface of the levator ani musculature. The tiny vascular branches and nerve fibers from the prostatic part were hard to identify. The cavernosal nerves cannot reliably be distinguished from the neural supply to the prostate, rectum and levator ani. In the cross-section of levels of prostatic base and mid-prostate in cadaveric hemipelvis specimens, the boundary of the prostatic part fat pad was partly overlapped and merged with the boundary of the mesorectum. Intraoperative observation showed that the areas of overlap referred to the rectal branches from the prostatic part piercing the proper fascia to supply the mesorectum, which carried the largest tension and high risk of bleeding during circumferential dissection toward the perirectal plane. The ultrasonic scalpel was required to pre-coagulate the rectal branches at the point close to the proper fascia of the rectum to prevent bleeding. In the cross-section of the prostatic apex level, the prostatic part approached ventrally and its boundary was away from the boundary of the mesorectum. Conclusions: NVB prostatic part injury is one of the causes of urogenital dysfunction after TME. The nerve fibers from the prostatic part were tiny, and its functional zones cannot be distinguished during operation. Therein, the fat pad of the prostatic part should be protected as a whole. Understanding the morphology of the fat pad of the prostatic part provides invaluable surgical guidance to dissect this critical area. When dissecting around the anterolateral rectal wall, appropriate anti-traction tension should be maintained and the rectal branches from the prostatic part should be coagulated with an ultrasonic scalpel to prevent bleeding.

Long-term outcomes of watch&wait (W&W) after neoadjuvant treatment in patients with rectal cancer / 中华放射肿瘤学杂志

Objective:To compare the outcomes of watch&wait (W&W) strategy in patients with locally advanced rectal cancer who achieved complete clinical response (cCR) after neoadjuvant therapy, with those who obtained pathological complete response (pCR) after total mesorectal excision (TME).Methods:This is a retrospective cohort analysis study. Patients histologically proven with locally advanced rectal adenocarcinoma (stage Ⅱ-Ⅲ) who had received neoadjuvant chemotherapy were eligible between January 2014 and December 2019. In whom we included patients who had cCR offered management with W&W strategy after completing neoadjuvant therapy and follow-up ≥1 year (W&W group), and patients who did not have cCR but pCR after TME (pCR group). The primary endpoints were 3-year and 5-year overall survival (OS), colostomy-free survival (CFS), disease-free survival (DFS), non-local regrowth disease-free survival (NR-DFS), and organ preservation rate. Kaplan-Meier analysis was used for survival analysis and log-rank test was performed. For comparative analysis, we also derived one-to-one paired cohorts of W&W versus pCR using propensity-score matching (PSM).Results:A total of 118 patients were enrolled, 49 of whom had cCR and managed by W&W, 69 had pCR, with a median follow-up period of 49.5 months (12.1-79.9 months). No difference was observed in the 3-year OS (97.1% vs. 96.7%) and 5-year OS (93.8% vs. 90.9%, P=0.696) between the W&W and pCR groups. Patients managed by W&W had significantly better 3-year and 5-year CFS (89.1% vs. 43.5%, P<0.001), better 3-year DFS (83.6% vs. 97.0%) and 5-year DFS (83.6% vs. 91.2%, P=0.047) compared with those achieving pCR. The 3-year NR-DFS (95.9% vs. 97.0%) and 5-year NR-DFS (92.8% vs. 97.0%, P=0.407) did not significantly differ between the W&W and pCR groups. Local regeneration occurred in six cases, and 87.7% of patients had successful rectum preservation in the W&W group. In the PSM analysis (34 patients in each group), absolutely better CFS (90.1% vs. 26.5%, P<0.001) was noted in the W&W group. A median interval of 17.5 weeks was observed for achieving cCR, while only 23.9% of patients achieved cCR within 5 to 12 weeks from radiation completion. Patients with short-course sequential chemoradiotherapy achieved cCR significantly later when compared with those with long-course concurrent chemoradiotherapy (19.0 vs. 9.8 weeks, P<0.001). Conclusions:The oncological outcomes of W&W strategy in patients with locally advanced rectal cancer are safe and effective, significantly improving the quality of life. Longer interval for cCR evaluation may improve rectal organ preservation rate.

Application value of stereotactic digital navigation system assisted three-dimensional lapa-roscopic total mesorectal excision for rectal cancer / 中华消化外科杂志

Objective:To investigate the application value of stereotactic digital naviga-tion system assisted three-dimensional (3D) laparoscopic total mesorectal excision (TME) for rectal cancer.Methods:The retrospective and descriptive study was conducted. The clinicopathological data of a healthy volunteer recruited by the Second Affiliated Hospital of Army Medical University and 3 patients who underwent stereotactic digital navigation system assisted 3D laparoscopic TME for rectal cancer in the Second Affiliated Hospital of Army Medical University from May to September 2019 were collected. The healthy volunteer was male, aged 25 years. Of the 3 rectal cancer patients, there were 2 males and 1 female, with the age of 48 years, 63 years and 67 years, respectively. Ten special patches were placed at the anterior superior iliac spine, pubic tubercle and pubic symphysis of the volunteer's bilateral inguen as skin reference points in intraoperative localization and system registration. On the day of operation, patients were placed 10 special patches as skin reference points according to the test results of the volunteer and were completed the enhanced scan of totally abdominal computed tomography examination. Seven fixed anatomical markers in the abdominal cavity of the patients, including abdominal aortic bifurcation, sacrum scapula, bilateral anterior superior iliac spine, bilateral intersection of ureter and iliac artery and median point of peritoneal reflection, were selected for verifying the accuracy of the correspondence between the instrument tip and the system image. Patients underwent 3D laparoscopic TME for rectal cancer assisted by stereotactic digital navigation system. Observation indicators: (1) test results; (2) surgical situations; (3) accuracy of stereotactic digital navigation system. Measurement data with normal distribution were represented as Mean± SD. Results:(1) Test results. The 10 skin reference points of the volunteer were successfully registered in the stereotactic digital navigation system, with the registration error of 2.8 mm. (2) Surgical situations. All the 3 patients underwent stereo-tactic digital navigation system assisted 3D laparoscopic TME for rectal cancer successfully. The operation time of the 3 patients were 193 minutes, 175 minutes, 210 minutes, respectively, in which the set time of the stereotactic digital navigation system were 34 minutes, 25 minutes, 45 minutes, respectively. The volume of intraoperative blood loss of the 3 patients were 60 mL, 30 mL, 80 mL, respectively. Results of postoperative pathological examination showed 3 patients with adenocar-cinoma, including 1 case with mucinous adenocarcinoma. The tumor diameter and the numbers of lymph nodes dissected of the 3 patients were 2.3 cm, 1.5 cm, 4.0 cm and 12, 12, 13, respectively. No patient had lymph node metastasis. The 3 patients in preoperative clinical TNM stage cT3bN0M0, stage cT4aN1M0, stage cT3bN1M0 were in yield pathological TNM stage ypT1N0M0, stage ypT4aN0M0, stage ypT2N0M0 after neoaduvant chemotherapy, respectively. No patient had complication, and the duration of postoperative hospital of the 3 patients was 7 days, 6 days, 7 days, respectively. (3) Accuracy of stereotactic digital navigation system. The registration errors of the skin reference points were 2.8 mm, 2.6 mm, 2.9 mm and the accuracy errors of the abdominal cavity reference points were (2.5±0.4)mm, (2.3±0.7)mm, (2.6±0.6)mm for the 3 patients.Conclusion:The stereotactic digital navigation system assisted 3D laparoscopic TME for rectal cancer is safe and feasible.

A new insights of mesorectum / 中华胃肠外科杂志

Total mesorectal excision (TME) represents the gold standard for radical resection in rectal cancer. The development in radiology and laparoscopic surgical equipment and the advancement in technology have led to a deepened understanding of the mesorectum and its surrounding structures. Both the accuracy of preoperative staging and the preciseness of the planes of TME surgical dissection have been enhanced. The postoperative local recurrence rate is reduced and the long-term survival of rectal cancer patients is improved. The preservation of the pelvic autonomic nervous system maintains the patient's urinary and sexual functions to the greatest extent possible, which in turn improves the patient's postoperative quality of life. A thorough understanding of the anatomy of the mesorectum and its surrounding structures is a prerequisite for successful TME. Herein, we review the basic concepts and the anatomy of the mesorectum in the current literature. Some important clinical issues are also discussed systematically in terms of imaging, surgery, and pathology.

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.

Current research status on pelvic autonomic nerve monitoring in rectal cancer surgery / 中华胃肠外科杂志

Rectal cancer is a common malignant tumor of the digestive tract, and surgery is the main treatment strategy. Disorders of bowel, anorectal and urogenital function remain common problems after total mesorectal resection (TME), which seriously decreases the quality of life of patients. Surgical nerve damage is one of the main causes of the complications, while TME with pelvic autonomic nerve preservation is an effective way to reduce the occurrence of adverse outcomes. Intraoperative nerve monitoring (IONM) is a promising method to assist the surgeon to identify and protect the pelvic autonomic nerves. Nevertheless, the monitoring methods and technical standards vary, and the clinical use of IONM is still limited. This review aims to summarize the researches on IONM in rectal and pelvic surgery. The electrical nerve stimulation technique and different methods of IONM in rectal cancer surgery are introduced. Also, the authors discuss the limitations of current researches, including methodological disunity and lack of equipment, then prospect the future direction in this field.

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)

Robotic versus laparoscopic total mesorectal excision surgery in rectal cancer: short-mid term oncological outcomes / 中华普通外科杂志

Objective:To investigate the safety and mid-term efficacy of robotic versus laparoscopic total mesorectal excision surgery in rectal cancer.Methods:A total of 240 patients were diagnosed with rectal cancer at the Anorectal Department of Gansu Provincial Hospital from Aug 2015 to Mar 2021, 112 patients underwent laparoscopic total mesorectal excision (L-TME group) and 128 patients did robotic-assisted total mesorectal excision (R-TME group).Results:Compared to the R-TME group, the L-TME group had higher conversion rate (5.4% vs. 0.8%, χ2=4.417, P=0.036), higher incidence of complications (32.1% vs. 17.2%, χ2=7.290, P=0.007), higher circumferential resection margin involvement (7.1% vs. 1.6%, χ2=4.658, P=0.031), lower 3-year DFS and OS(74.1% vs. 85.2%, χ2=4.962, P=0.026) and (81.3% vs. 91.4%, χ2=5.494, P=0.019), lower 3-year DFS and OS in AJCC stage Ⅲ(52.5% vs. 76.1%, χ2=5.799, P=0.016) and (65.0% vs. 84.8%, χ2=4.787, P=0.029). Conclusion:R-TME can achieve better oncological outcomes and is more beneficial for RC patients compared with L-TME, especially for those with stage Ⅲ rectal cancers.

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.

Chinese consensus on Denonvilliers' fascia preserving total mesorectal excision (iTME) (2021 version) / 中华胃肠外科杂志

In 1982, total mesorectal excision(TME) was proposed by Professor R. J. Heald, which was a milestone-style for rectal cancer surgery. The concept of TME has reduced the local recurrence rate of mid-low rectal cancer (MLRC) significantly, thus becomes the gold standard for MLRC surgery. However, the incidence of urogenital dysfunction after TME remains high, among which urinary dysfunction reaches 30%-60%, and sexual dysfunction reaches 50%-70%. In recent years, studies have shown that the removal of Denonvilliers' fascia (DVF) during TME is an important cause of postoperative urination and sexual dysfunction. Therefore, DVF preserving total mesorectal excision (iTME) has been recognized by more and more surgical experts. On the basis of existing literature and clinical practice, we organize experts to discuss and vote, put forward recommendations for several issues of iTME, and finally formulate this expert consensus. The formulation of this consensus aims to increase surgeons' awareness of the value and functional protection of DVF during TME surgery, clarify the indications and contraindications of iTME, and standardize the procedure of iTME, so as to reduce postoperative urination and sexual dysfunction and improve the quality of life of patients with MLRC. The level of evidence and recommendation of this consensus is determined by Grading Recommendations, Assessment, Development and Evaluation (GRADE), and the consensus content is determined through expert voting and Delphi method.