Previous studies have demonstrated the advantages of short-term histopathological outcomes and complications associated with transanal total mesorectal excision (TME) compared with laparoscopic TME. However, the long-term oncological outcomes of transanal TME remain ambiguous. This study aims to compare 3-year disease-free survival of transanal TME with laparoscopic TME.

To evaluate 3-year disease-free survival between transanal TME and laparoscopic TME in patients with rectal cancer.

This randomized, open-label, noninferiority, phase 3 clinical trial was performed in 16 different centers in China. Between April 2016 and June 2021, a total of 1115 patients with clinical stage I to III mid-low rectal cancer were enrolled. The last date of participant follow-up was in June 2024.

Participants were randomly assigned in a 1:1 ratio before their surgical procedure to undergo either transanal TME (n = 558) or laparoscopic TME (n = 557).

The primary end point was 3-year disease-free survival, with a noninferiority margin of -10% for the comparison between transanal TME and laparoscopic TME. Secondary outcomes included 3-year overall survival and 3-year local recurrence.

In the primary analysis set, the median patient age was 60 years. A total of 692 male and 397 female patients were included in the analysis. Three-year disease-free survival was 82.1% (97.5% CI, 78.4%-85.8%) for the transanal TME group and 79.4% (97.5% CI, 75.6%-83.4%) for the laparoscopic TME group, with a difference of 2.7% (97.5% CI, -3.0% to 8.1%). The lower tail of a 2-tailed 97.5% CI for the group difference in 3-year disease-free survival was above the noninferiority margin of -10 percentage points. Furthermore, the 3-year local recurrence was 3.6% (95% CI, 2.0%-5.1%) for transanal TME and 4.4% (95% CI, 2.6%-6.1%) for laparoscopic TME. Three-year overall survival was 92.6% (95% CI, 90.4%-94.8%) for transanal TME and 90.7% (95% CI, 88.3%-93.2%) for laparoscopic TME.

In patients with mid-low rectal cancer, 3-year disease-free survival for transanal TME was noninferior to that of laparoscopic TME.

ClinicalTrials.gov Identifier: NCT02966483.

The best approach for total mesorectal excision (TME) remains controversial. Two recently described approaches are robotic TME (RTME) and transanal TME (TaTME). This systematic review and meta-analysis aimed to compare the outcomes between robotic surgery and TaTME in patients undergoing rectal cancer resection.

We structured this systematic review and meta-analysis according to the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) guidelines 2020 and Assessing the Methodological Quality of Systematic Reviews (AMSTAR) guidelines. An electronic search of relevant literature was conducted on 20 May 2023. The protocol was registered in PROSPERO (CRD42023435259).

Eleven eligible nonrandomised studies were included in this study. The study included 2796 patients (RTME = 1800; TaTME = 996). The RTME group had a higher rate of complete TME. However, no significant differences were observed in mortality, morbidity, severe complications, operative time, conversion rate, anastomotic leak, hospital stay, CRM-positive resection margin, distal resection margin, number of harvested lymph nodes, abdominoperineal resection (APR) rate, or local recurrence between the RTME and TaTME groups.

The RTME technique may ensure a higher rate of complete TME than TaTME. However, no significant differences were observed in most postoperative outcomes and oncological safety between the RTME and TaTME groups. Evidence does not conclusively favor one technique over the other, highlighting the need for additional randomized controlled trials to better define their roles in rectal cancer surgery.

While total mesorectal excision is the gold standard for rectal cancer, the optimal surgical approach to achieve adequate oncological outcomes remains controversial. This network meta-analysis aims to compare the histopathological outcomes of robotic (R-RR), transanal (Ta-RR), laparoscopic (L-RR), and open (O-RR) resections for rectal cancer.

MEDLINE, Embase, and the Cochrane Library were screened from inception to June 2024. Of the 4186 articles screened, 27 RCTs were selected. Pairwise comparisons and Bayesian network meta-analyses applying random effects models were performed.

The 27 RCTs included a total of 8696 patients. Bayesian pairwise meta-analysis revealed significantly lower odds of non-complete mesorectal excision with Ta-RR (Odds Ratio, OR, 0.60; 95%CI, 0.33, 0.92; P = .02; I2:11.7 %) and R-RR (OR, 0.68; 95%CI, 0.46, 0.94; P = .02; I2:41.7 %) compared with laparoscopy. Moreover, lower odds of positive CRMs were observed in the Ta-RR group than in the L-RR group (OR, 0.36; 95%CI, 0.13, 0.91; P = .02; I2:43.9 %). The R-RR was associated with more lymph nodes harvested compared with L-RR (Mean Difference, MD, 1.24; 95%CI, 0.10, 2.52; P = .03; I2:77.3 %). Conversely, Ta-RR was associated with a significantly lower number of lymph nodes harvested compared with all other approaches. SUCRA plots revealed that Ta-RR had the highest probability of being the best approach to achieve a complete mesorectal excision and negative CRM, followed by R-RR, which ranked the best in lymph nodes retrieved.

When comparing the effectiveness of the available surgical approaches for rectal cancer resection, Ta-RR and R-RR are associated with better histopathological outcomes than L-RR.

Transanal total mesorectal excision (TaTME) is a promising and innovative approach for lower rectal cancer but requires high technical skill and learning process that can affect patient outcomes. We aimed to determine the learning curve of TaTME and then to assess its impact on 5-year oncologic outcomes.

Over a 54-month period, 94 patients underwent TaTME by experienced laparoscopic colorectal surgeons at our department. To provide a comprehensive overview of success, we used a composite criterion including the most relevant parameters related to the learning process: the conversion rate to an open procedure, TaTME procedure completion, severe postoperative morbidity, mesorectal integrity on macroscopic evaluation, and microscopic margins. Moving average method and cumulative sum analyses were performed.

The operative time continuously decreased over the entire study period. The success rate stabilised after 14 patients in a parallel and balanced analysis of the two surgeons' experiences. Mesorectal completeness was the most sensitive marker for the TaTME learning process (42.9% vs 71.25%; p = 0.06). The learning process did not significantly affect the postoperative morbidity, conversion rate, or R0 resection. Five-year oncological outcomes were similar between the groups.

Even among laparoscopically experienced surgeons, the TaTME learning process influences the oncological quality of the resection but not the postoperative morbidity. Gaining an early command of the surgical anatomy and technical skills and understanding the challenges through specific educational sessions are necessary. The results of this study could help generate a comprehensive training program and define necessary prerequisites for prospective trials.

This study is registered in our Clinical Research Unit (2016_LELONG_01). Our database is registered in the clinicalTrials.gov registry: Institut Paoli Calmettes Colorectal Cancer Database (NCT02869503).

Despite being reported safety, the advantages of transanal minimally invasive proctocolectomy (TAMIP) are controversial, and comparative studies on postoperative defecation function between ileal pouch-anal anastomosis (IPAA) using laparoscopic transanal manipulation (TAMIP-IPAA) and without this technique (traditional IPAA) are lacking. This study analyzed TAMIP's impact on short-term and postoperative defecation function in patients with ulcerative colitis (UC) to evaluate its safety and feasibility.

Inclusion criteria comprised patients with UC undergoing minimally invasive proctocolectomy at our hospital from May 2014 to May 2023. The TAMIP-IPAA approach involved precise rectal mucosa removal while preserving the sphincter muscle during laparoscopic transanal manipulation.

In the evaluation of short-term outcomes for 71 patients undergoing proctocolectomy, the TAMIP group (37 patients) outperformed the non-TAMIP group in operative time (395 vs. 289 min, p < 0.001) and postoperative hospital stay (12 vs. 8 days, p < 0.001). Additionally, TAMIP-IPAA demonstrated advantages over traditional IPAA (seven patients), in operative time (443 vs. 289 min, p = 0.006), intraoperative blood loss (392 vs. 130 mL, p = 0.001), postoperative hospital stay (18 vs. 8 days, p = 0.003), anastomotic leakage (42.9% vs. 8.1%, p = 0.041), and re-admission within 30 days (57.1% vs. 8.1%, p = 0.009). Wexner scores were significantly superior in the TAMIP-IPAA group at 6 months (14.5 vs. 8.0 points, p = 0.029) and 1 year post stoma closure (14.0 vs. 7.0 points, p = 0.020), indicating enhanced short-term outcomes and defecation function compared to traditional IPAA.

TAMIP-IPAA for UC has the potential to offer promising benefits, including the enhancement of short-term outcomes and the improvement of defecation function.

The objective of this study is to develop a nomogram for the personalized prediction of postoperative complication risks in patients with middle and low rectal cancer who are undergoing transanal total mesorectal excision (taTME). This tool aims to assist clinicians in early identification of high-risk patients and in addressing preoperative risk factors to enhance surgical safety.

In this case-control study, 207 patients diagnosed with middle and low rectal cancer and undergoing taTME between February 2018 and November 2023 at The First Affiliated Hospital of Xiamen University were included. Independent risk factors for postoperative complications were analyzed using the Least Absolute Shrinkage and Selection Operator (LASSO) regression and multifactorial logistic regression models. A predictive nomogram was constructed using R Studio.

Among the 207 patients, 57 (27.5%) experienced postoperative complications. The LASSO and multifactorial logistic regression analyses identified operation time (OR = 1.010, P = 0.007), smoking history (OR = 9.693, P < 0.001), anastomotic technique (OR = 0.260, P = 0.004), and ASA score (OR = 9.077, P = 0.051) as significant predictors. These factors were integrated into the nomogram. The model's accuracy was validated through receiver operating characteristic curves, calibration curves, consistency indices, and decision curve analysis.

The developed nomogram, incorporating operation time, smoking history, anastomotic technique, and ASA score, effectively forecasts postoperative complication risks in taTME procedures. It is a valuable tool for clinicians to identify patients at heightened risk and initiate timely interventions, ultimately improving patient outcomes.

This study aimed to review the historical transition of rectal cancer surgery and recent evidence regarding transanal total mesorectal excision (TaTME). Additionally, it outlined the anatomical landmarks and technical considerations essential for successful TaTME. Anatomical studies and surgical techniques were analyzed to identify key landmarks and procedural steps crucial for TaTME. TaTME offers improved visibility and maneuverability even in the deep and narrow pelvis and is expected to contribute to tumor radical cure rates. By securing the circumferential resection margin and distal margin while preserving pelvic autonomic nerve function, TaTME holds promise for maintaining postoperative urinary and sexual functions. Key anatomical landmarks include the endopelvic fascia posteriorly, the S4-pelvic splanchnic nerve laterally, and the prostate or posterior vaginal wall anteriorly. Selecting the appropriate dissection layer based on tumor depth and ensuring precise incision of the tendinous arch of the pelvic fascia contributes to successful TaTME outcomes. TaTME represents a significant advancement in rectal cancer surgery, offering improved outcomes through meticulous attention to anatomical detail and precise dissection techniques. Understanding the historical context of rectal cancer surgery alongside recent evidence on TaTME is essential for optimizing patient outcomes and expanding the safe implementation of this innovative approach.

An unexpectedly large number of patients experienced local recurrence with transanal total mesorectal excision in Norway. This appears to be associated with cancer cell spillage during surgery.

To investigate the surgical field cytology during transanal total mesorectal excision.

This was a prospective cohort study.

This study was conducted at a single center between June and December 2020.

Forty patients with rectal cancer underwent transanal total mesorectal excision. After irrigation of the surgical field, the water specimens were cytologically evaluated at 6 representative steps. The first sample was used as an initial control. The second, third, fourth, fifth, and sixth samples were collected after the first pursestring suture, rectotomy, the second pursestring suture, specimen resection, and anastomosis, respectively. The clinicopathological features and intraoperative complications of the patients were reviewed.

The primary outcome was to evaluate the presence of cancer cells in washing cytological samples.

Of the 40 consecutive patients enrolled in this study, 18 patients underwent neoadjuvant chemoradiotherapy. Incomplete first pursestring suture and rectal perforation were observed in 4 (10.0%) and 3 (7.5%) cases, respectively. In the first sample, 31 patients (77.5%) had malignant cells. Malignant findings were detected in 2 patients (5.0%) from the second to fifth samples. None of the sixth sample exhibited any malignant findings.

This single-center study had a small sample size.

Cancer cells were initially detected by cytology, but only a few were observed throughout the procedure; however, cancer cells were not detected in the final surgical field. Further follow-up and novel studies are required to obtain clinically significant findings using cytology during transanal total mesorectal excision. See Video Abstract .

ANTECEDENTES:Un número inesperadamente grande de pacientes experimentó recurrencia local con la escisión total del mesorrecto transanal en Noruega. Esto parece estar asociado con el derrame de células cancerosas durante la cirugía.OBJETIVO:Investigar la citología del campo quirúrgico durante la escisión total del mesorrecto transanal.DISEÑO:Este fue un estudio de cohorte prospectivo.ENTORNO CLINICO:Este estudio se realizó en un solo centro entre junio y diciembre de 2020.PACIENTES:Cuarenta pacientes con cáncer de recto se sometieron a escisión total del mesorrecto transanal. Después de la irrigación del campo quirúrgico, las muestras de agua se evaluaron citológicamente en seis pasos representativos. La primera muestra se utilizó como control inicial. La segunda, tercera, cuarta, quinta y sexta muestras se recolectaron después de la primera sutura en bolsa de tabaco, la rectotomía, la segunda sutura en bolsa de tabaco, la resección de la muestra y la anastomosis, respectivamente. Se revisaron las características clínico-patológicas y las complicaciones intraoperatorias de los pacientes.PRINCIPALES MEDIDAS DE RESULTADO:El resultado primario fue evaluar la presencia de células cancerosas en el lavado de muestras citológicas.RESULTADOS:De los 40 pacientes consecutivos inscritos en este estudio, 18 pacientes se sometieron a quimiorradioterapia neoadyuvante. Se observaron la primera sutura en bolsa de tabaco incompleta y perforación rectal en cuatro (10,0%) y tres (7,5%) casos, respectivamente. En la primera muestra, 31 (77,5%) pacientes tenían células malignas. Se detectaron hallazgos malignos en dos pacientes (5,0%) de la segunda a la quinta muestra. Ninguno de la sexta muestra demostraron hallazgos malignos.LIMITACIONES:Este estudio unicéntrico tuvo un tamaño de muestra pequeño.CONCLUSIONES:Inicialmente se detectaron células cancerosas mediante citología, pero solo se observaron unas pocas durante todo el procedimiento; sin embargo, no se detectaron células cancerosas en el campo quirúrgico final. Se requieren más seguimientos y estudios novedosos para obtener hallazgos clínicamente significativos mediante citología durante la escisión total del mesorrecto transanal. (Traducción- Dr. Francisco M. Abarca-Rendon ).

This study aimed to clarify the efficacy and safety of minimally invasive transabdominal surgery (MIS) with transperineal minimal invasive surgery (tpMIS) for sacrectomy in advanced primary and recurrent pelvic malignancies.

Using a prospectively collected database, we retrospectively analyzed the clinical, surgical, and pathological outcomes of MIS with tpMIS for sacrectomies. Surgery was performed between February 2019 and May 2023. The median follow-up period was 27 months (5-46 months).

Fifteen consecutive patients were included in this analysis. The diagnoses were as follows: recurrent rectal cancer, n = 11 (73%); primary rectal cancer, n = 3 (20%); and recurrent ovarian cancer, n = 1 (7%). Seven patients (47%) underwent pelvic exenteration with sacrectomy, six patients (40%) underwent abdominoperineal resection (APR) with sacrectomy, and two patients (13%) underwent tumor resection with sacrectomy. The median intraoperative blood loss was 235 ml (range 45-1320 ml). The postoperative complications (Clavien-Dindo grade ≥ 3a) were graded as follows: 3a, n = 6 (40%); 3b, n = 1 (7%); and ≥ 4, n = 0 (0%). Pathological examinations demonstrated that R0 was achieved in 13 patients (87%). During the follow-up period, two patients (13%) developed local re-recurrence due to recurrent cancer. The remaining 13 patients (87%) had no local disease. Fourteen patients (93%) survived.

Although the patient cohort in this study is heterogeneous, MIS with tpMIS was associated with a very small amount of blood loss, a low incidence of severe postoperative complications, and an acceptable R0 resection rate. Further studies are needed to clarify the long-term oncological feasibility.

The benefits and short-term outcomes of transanal total mesorectal excision (taTME) for rectal cancer have been demonstrated previously, but questions remain regarding the oncologic outcomes following this challenging procedure. The purpose of this study was to analyze the oncologic outcomes following taTME at high-volume centers in the USA.

This was a multicenter, retrospective observational study of 8 tertiary care centers. All consecutive taTME cases for primary rectal cancer performed between 2011 and 2020 were included. Clinical, histopathologic, and oncologic data were analyzed. Primary endpoints were rate of local recurrence, distal recurrence, 3-year disease recurrence, and 3-year overall survival. Secondary endpoints included perioperative complications and TME specimen quality.

A total of 391 patients were included in the study. The median age was 57 years (IQR: 49, 66), 68% of patients were male, and the median BMI was 27.4 (IQR: 24.1, 31.0). TME specimen was complete or near complete in 94.5% of cases and the rates of positive circumferential radial margin and distal resection margin were 2.0% and 0.3%, respectively. Median follow-up time was 30.7 months as calculated using reverse-KM estimator (CI 28.1-33.8) and there were 9 cases (2.5%) of local recurrence not accounting for competing risk. The 3-year estimated rate of disease recurrence was 19% (CI 15-25%) and the 3-year estimated overall survival was 90% (CI 87-94%).

This large multicenter study confirms the oncologic safety and perioperative benefits of taTME for rectal cancer when performed by experienced surgeons at experienced referral centers.

Comparative outcomes of robotic low anterior resection (rTME) and trans-anal total mesorectal excision (TaTME) in patients with low rectal cancer were evaluated.

A systematic online search was conducted using the following databases: PubMed, Scopus, Cochrane database, The Virtual Health Library, Clinical trials.gov and Science Direct. Comparative studies of rTME versus TaTME for low rectal cancer were included. Primary outcomes were postoperative complications, including anastomotic leak, surgical site infection, and Clavien-Dindo complication rate. Total operative time, conversion to open surgery, intra-operative blood loss, intensive therapy unit (ITU) and total hospital length of stay (LOS), oncological outcomes and functional outcomes were the other evaluated outcome parameters.

A total of 12 studies with a total number of 3025 patients divided between rTME (n = 1881) and TaTME (n = 1144) groups were included. There was no significant difference between the two groups for total operative time (P = 0.39), conversion to open surgery (P = 0.29) and intra-operative blood loss (P = 0.62). Clavien-Dindo ≥ 3 complication rate (P = 0.47), anastomotic leak (P = 0.89), rates of re-operation (P = 0.62) and re-admission (P = 0.92), R0 resections (P = 0.52), ITU LOS (P = 0.63) and total hospital LOS (P = 0.30) also showed similar results between the two groups. However, the rTME group had higher rates of total harvested lymph nodes (P = 0.04) and complete total mesorectal excision (TME) resections (P = 0.05). Albeit with a limited dataset, the Wexner and low anterior resection syndrome (LARS) scores showed better functional results in the rTME group compared with the TaTME group (P = 0.0009 and P = 0.00001, respectively).

Compared with TaTME, rTME seems to provide better functional outcomes, higher lymph node yield and more complete TME resections with a similar post-operative complications profile.

Trans-anal total mesorectal excision (Ta-TME) is a novel approach for the resection of rectal cancer. Low anterior resection syndrome (LARS) is a frequent functional disorder that might follow restorative proctectomy. Data regarding bowel function after Ta-TME are scarce. The aim of this study was to evaluate the incidence and risk factors for the development of LARS following Ta-TME.

A prospectively maintained database of all patients who underwent Ta-TME for rectal cancer at our institution was reviewed. All patients who were operated on from January 2018 to December 2021 were evaluated. The LARS score questionnaire was used via telephone interviews. Incidence, severity and risk factors for LARS were evaluated.

Eighty-five patients underwent Ta-TME for rectal cancer between January 2018 and December 2021. Thirty-five patients were excluded due to ostomy status, death, local disease recurrence, ileal pouch or lack of compliance. Fifty patients were included in the analysis. LARS was diagnosed in 76% of patients. Anastomosis distance from dentate line was identified as a risk factor for LARS via multivariate analysis (p = 0.042). Neo-adjuvant therapy, hand sewn anastomosis and anastomotic leak did not increase the risk of LARS.

LARS is a frequent condition following ta-TME, as it is used for other approaches to low anterior resection. Anastomosis distance from dentate line is an independent risk factor for LARS. In this study neo-adjuvant therapy, hand sewn anastomosis and anastomotic leak did not increase the risk of LARS. Further studies with longer follow-up times are required to better understand the functional outcomes following Ta-TME.

Intensive treatment is typically considered for very high-risk patients with locally advanced prostate cancer and an expected survival time of 5 years or longer. Herein, we report a case of locally advanced prostate cancer with rectal infiltration treated with laparoscopic total pelvic exenteration combined with transanal total mesorectal excision.

A 73-year-old man presented with a ring-shaped mass around the rectum. He was diagnosed with prostate cancer with rectal infiltration and underwent laparoscopic total pelvic exenteration combined with transanal total mesorectal excision following neoadjuvant androgen deprivation therapy. Twenty-two months postoperatively during ongoing androgen deprivation therapy, no biochemical recurrence was observed.

To our knowledge, this is the first report of a laparoscopic total pelvic exenteration combined with transanal total mesorectal excision for prostate cancer with rectal infiltration. We believe this surgery may be considered a new option for high-risk prostate cancer patients with rectal infiltration.

Transanal TME (taTME) combines abdominal and transanal dissection to facilitate sphincter preservation in patients with low rectal tumors. Few phase II/III trials report long-term oncologic and functional results. We report early results from a North American prospective multicenter phase II trial of taTME (NCT03144765).

100 patients with stage I-III rectal adenocarcinoma located ≤ 10 cm from the anal verge (AV) were enrolled across 11 centers. Primary and secondary endpoints were TME quality, pathologic outcomes, 30-day and 90-day outcomes, and stoma closure rate. Univariable regression analysis was performed to assess risk factors for incomplete TME and anastomotic complications.

Between September 2017 and April 2022, 70 males and 30 females with median age of 58 (IQR 49-62) years and BMI 27.8 (IQR 23.9-31.8) kg/m2 underwent 2-team taTME for tumors located a median 5.8 (IQR 4.5-7.0) cm from the AV. Neoadjuvant radiotherapy was completed in 69%. Intersphincteric resection was performed in 36% and all patients were diverted. Intraoperative complications occurred in 8% including 3 organ injuries, 2 abdominal and 1 transanal conversion. The 30-day and 90-day morbidity rates were 49% (Clavien-Dindo (CD) ≥ 3 in 28.6%) and 56% (CD ≥ 3 in 30.4% including 1 mortality), respectively. Anastomotic complications were reported in 18% including 10% diagnosed within 30 days. Higher anastomotic risk was noted among males (p = 0.05). At a median follow-up of 5 (IQR 3.1-7.4) months, 98% of stomas were closed. TME grade was complete or near complete in 90%, with positive margins in 2 cases (3%). Risk factors for incomplete TME were ASA ≥ 3 (p = 0.01), increased time between NRT and surgery (p = 0.03), and higher operative blood loss (p = 0.003).

When performed at expert centers, 2-team taTME in patients with low rectal tumors is safe with low conversion rates and high stoma closure rate. Mid-term results will further evaluate oncologic and functional outcomes.

The objective of this study was to evaluate treatment outcomes in patients who underwent the TaTME procedure for cancer of the middle and low rectum in an expert center. Prospective analysis of the outcomes of all consecutive patients treated using the TaTME technique for cancer of the middle and distal rectum at the our medical center between March 1, 2015, and March 31, 2022. A total of 128 patients (34 women, 94 men; mean age 66.01 [38-85] years) with cancer of the middle and distal rectum qualified for TaTME. TaTME procedures were performed in 127/128 (99.22%) patients. Complications of surgery were observed in 22/127 (17.32%) patients. Negative proximal and distal margins were confirmed in all 127 patients. Complete (R0) resection of the mesorectum was confirmed in 125/127 (98.43%) and nearly complete (R1) resection was confirmed in 2/127 (1.57%) patients. The average follow-up period was 795 days (296-1522) days. Local recurrence was detected during the follow-up period in 2/127 (1.57%) patients. This study showed that the TaTME procedure is an effective and safe method for the minimally invasive treatment of middle and low rectal cancers, particularly within an expert center setting.

Transanal total mesorectal excision (taTME) is a technique where rectal dissection is begun transanally in a "bottom-up" fashion. This technique facilitates dissection of the most distal part of the rectum and allows the establishment of the distal margin for rectal cancer. TaTME has proven its utility in facilitating low rectal dissection with significantly lower conversion rates and acceptable perioperative, oncological, and functional outcomes. However, taTME remains a challenging technique to learn and adopt. This article describes the technique, indications, and outcomes of taTME in rectal cancer during the last decade.

Transanal total mesorectal excision (TaTME) has been proposed to overcome surgical difficulties encountered during rectal resection, especially for patients having high body mass index or low rectal cancer. The aim of this study was to evaluate oncologic outcomes following TaTME.

This retrospective study included all consecutive patients with rectal cancer who had a TaTME from 2013 to 2019. The main outcome was the incidence of locoregional recurrence by the end of the follow-up period.

Among a total of 81 patients, 96.3% were male, and their mean age was 63±9 years. The mean body mass index was 30.3±5.7 kg/m2, and the median distance from tumor to anal verge was 5.0 cm (interquartile range [IQR], 4.0-6.0 cm). Most patients had a low anterior resection performed (n=80, 98.8%) with a diverting ileostomy (n=64, 79.0%). Distal and circumferential resection margins were positive in 2.5% and 6.2% of patients, respectively. Total mesorectal excision was complete or near complete in 95.1% of patients. A successful resection was achieved in 72 patients (88.9%). After a median follow-up of 27.5 months (IQR, 16.7-48.1 months), 4 patients (4.9%) experienced locoregional recurrence. Anastomotic leaks were observed in 21 patients (25.9%). At the end of the follow-up, 69 patients (85.2%) were stoma-free.

TaTME was associated with acceptable oncological outcomes, including low locoregional recurrence rates in selected patients with low rectal cancer. Although associated with a high incidence of postoperative morbidities, the use of TaTME enabled a high rate of successful sphincter-saving procedures in selected patients who posed a technical challenge.

Minimally invasive (MI) surgery has revolutionised surgery, becoming the standard of care in many countries around the globe. Observed benefits over traditional open surgery include reduced pain, shorter hospital stay, and decreased recovery time. Gastrointestinal surgery in particular was an early adaptor to both laparoscopic and robotic surgery. Within this review, we provide a comprehensive overview of the evolution of minimally invasive gastrointestinal surgery and a critical outlook on the evidence surrounding its effectiveness and safety.

A literature review was conducted to identify relevant articles for the topic of this review. The literature search was performed using Medical Subject Heading terms on PubMed. The methodology for evidence synthesis was in line with the four steps for narrative reviews outlined in current literature. The key words used were minimally invasive, robotic, laparoscopic colorectal, colon, rectal surgery.

The introduction of minimally surgery has revolutionised patient care. Despite the evidence supporting this technique in gastrointestinal surgery, several controversies remain. Here we discuss some of them; the lack of high level evidence regarding the oncological outcomes of TaTME and lack of supporting evidence for robotic colorectalrectal surgery and upper GI surgery. These controversies open pathways for future research opportunities with RCTs focusing on comparing robotic to laparoscopic with different primary outcomes including ergonomics and surgeon comfort.

Transanal Total Mesorectal Excision (TaTME) represents the latest surgical approach in rectal cancer management. We present a rare case of vesicorectal fistula (VRF) following a complication of TaTME surgery.

A 67-year-old male underwent a Hartmann's procedure for perforated rectosigmoid cancer in 2019. He was lost to follow-up and re-presented in 2021 with synchronous cancer of the transverse colon and rectum. A two-team surgical approach was utilized: open subtotal colectomy (transabdominal approach) with concurrent excision of rectal stump (TaTME approach). Intraoperatively, an inadvertent bladder injury was identified and repaired. 8 months later, he re-presented with the passage of urine per rectum. Imaging and endoscopy revealed a VRF with cancer recurrence at the rectal stump.

VRF is an uncommon complication of TaTME that carries a significant physical and psychological impact on the patient. While shown to be a safe and useful technique, the long-term oncological outcomes of TaTME are still awaited. Unique complications have been reported with TaTME, including gas embolism and injuries to the genitourinary structures, in which the latter caused the eventual VRF formation in our patient.

Revisional surgery for recurrent disease is challenging and can result in rare complications, especially in patients with distorted anatomy and when new surgical techniques are utilized. Radiotherapy further causes unpredictable tissue healing quality. The challenge remains for proper patient selection with individualization of surgical approaches, while keeping a close eye on the oncological outcomes of the patient.

A transanal total mesorectal excision (taTME) is a smart alternative to a conventional TME. However, worrisome reports of a high recurrence and complications triggered a moratorium in a few countries. This study assessed the outcomes and resource utilization of a taTME. Consecutive patients with distal rectal cancer treated by a taTME were prospectively included. Outcomes were reported as the median and interquartile range (IQR). One hundred sixty-five patients (67% male and 33% female) with a tumor 7 cm (IQR 5-10) from the anal verge were followed for 50 months (IQR 32-79). The resection margins were threatened in 25% of the patients, while 75% of the patients received neoadjuvant radiochemotherapy. A good mesorectal dissection and clear margins were achieved in 96% of the specimens, and 27 lymph nodes (IQR 20-38) were harvested. Ninety-day major morbidity affected 36 patients (21.8%), including 12 with anastomotic leakages (7.2%). A recurrence occurred locally in 9 patients (5.4%), and 44 patients had a distant metastasis (26.7%). The five-year disease-free survival and overall survival were 67% and 90%, respectively. A multivariate analysis found a long operation and frailty predicted an anastomotic leak, while a positive distal margin and lymph nodes predicted a local recurrence and distant metastasis. A two-team taTME saved 102 min of operative time and EUR 1385 when compared to a one-team approach. Transanal total mesorectal excision produced sound surgical quality and excellent oncologic outcomes.

Transanal total mesorectal excision (taTME) is a promising surgical procedure for middle and low rectal cancer; however, it is linked to significant morbidity. This study aimed to determine the incidence of postoperative surgical complications and anastomotic leakage following taTME and to identify their associated risk factors.

The prospective clinical data of 114 patients, who underwent taTME and primary anastomosis for mid-low rectal cancer between November 2016 and June 2022, were retrospectively analyzed. Univariate and multivariate analyses were performed to identify clinical characteristics and risk factors for predicting surgical complications and anastomotic leakage.

Surgical complications occurred in 40 (35.1%) patients within the first 30 days following surgery. Based on the Clavien-Dindo classification, minor complications (Clavien-Dindo grades I + II) accounted for 30.7%, while major complications (Clavien-Dindo grades III + IV) accounted for only 4.4%. None of the patients died within 30 days. The incidence of anastomotic leakage was 15.8%: 4.4% as grade A (5 cases), 9.6% as grade B (11 cases), and 1.8% as grade C (2 cases). Preoperative T3-4 was identified as an independent risk factor for surgical complications (p = 0.031) by multivariate analysis. American Society of Anesthesiology score ≥ 3 (P = 0.021) and incomplete total mesorectal excision specimens (P = 0.030) were significantly associated with the risk of anastomotic leakage.

In this study, the incidence of surgical complications and anastomotic leakage in taTME aligned with previously reported rates. Preoperative T3-4 was significantly associated with surgical complications. American Society of Anesthesiology score ≥ 3 and incomplete TME specimens independently increased the risk of anastomotic leakage.

Laparoscopic total mesorectal excision (LaTME) is a technically challenging for ultralow-lying rectal cancer in obese male patients. Herein, we introduced modified serial techniques "ASTRO" to facilitate LaTME, and the short-term outcomes were presented.

A prospective study (NCT05067413) was conducted between December 2020 and January 2022. The modified serial surgical techniques "ASTRO" included 5 key steps: (1) Anterior peritoneal reflection (APR) dissection at the highest line along with a "n"-shaped membrane bridge; (2) suspending the APR with a purse-string suture through the bladder peritoneum to enlarge the operating space of the anterior rectal wall; (3) traction and counter-traction continuously of the rectum applied with a cotton tape around the rectum; (4) resection of the pelvic rectum on tripartition, followed by the sequence of "posterior > anterior > lateral" principle; and (5) the trans-anterior Obturator nerve gateway was adapted to transect the distal rectum. The operative data and postoperative short-term outcomes were collected.

Twenty-four consecutive patients underwent this procedure successfully. The average body mass index (BMI) was 29.9±1.3. The average of tumor height from anal verge was 4.0 cm (range, 3.0-4.5 cm). The median operating time and blood loss was 217 min (range, 165-420 min) and 50 ml (range, 20-100 ml) respectively. The anterior operation space at the midsagittal plane of the pelvis inlet was increased by 2.0 ± 0.3 cm. The calculated dominant angle was 20 ± 3°. The length of stapling line was 6.8 ± 1.0 cm with 11 cases by one cartridge and 13 cases by 2 cartridges. Eight patients developed postoperative complications including 4 with anastomosis leakage (16.7%), 2 with urinary retention (8.3%), one with anastomotic stenosis (4.2%) and one with ileus (4.2%). All the complications were relatively mild and the patients recovered well.

Modified serial techniques "ASTRO" could expand the operating space and facilitate LaTME in obese male patients, thereby reducing the risk of conversion to open and transanal dissection.

Currently, hand-sewn anastomosis is the standard procedure for inter-sphincteric resection (ISR); however, distal purse-string suturing during transanal total mesorectal excision (TaTME) has allowed a single-stapling technique (SST). Although it was originally intended for cases requiring anastomosis of 2 cm or more above the anorectal junction (ARJ), SST could be safely performed in ISR. The aim of this trial is to determine the superiority of SST over hand-sewn anastomosis in ISR with TaTME.

The Super SST trial is a multicentre randomized clinical trial comparing stapled and hand-sewn anastomoses in ISR with TaTME. The trial will recruit patients scheduled for TaTME with anastomosis below the ARJ, who will be allocated 1:1 to receive either hand-sewn or stapled anastomosis. The primary endpoint is anastomosis-related complications within 30 postoperative days. Secondary endpoints include all early and late complications, operating time, reoperation, mortality rate, length of postoperative hospital stay, readmission, incidence of anal pain and rectal mucosal prolapse, length of temporary stoma retention, the proportion of patients with a temporary stoma at 1 year after surgery, and anorectal function at 1 year after surgery.

This trial will provide important clinical insights for new and promising anastomotic options for patients with very low rectal cancer. Registration number: UMIN000047818 (https://www.umin.ac.jp/ctr/index-j.htme).

Transanal total mesorectal excision (taTME) has been rapidly accepted as a promising surgical approach to the distal rectum. The benefits include ease of access to the bottom of the deep pelvis linearly over a short distance in order to easily visualize the important anatomy. Furthermore, the distal resection margins can be secured under direct vision. Additionally, a two-team approach combining taTME with a transabdominal approach could decrease the operative time and conversion rate. Although taTME was expected to become more rapidly popularized worldwide, enthusiasm for it has stalled due to unfamiliar intraoperative complications, a lack of oncologic evidence from randomized trials, and the widespread use of robotic surgery. While international registries have reported favorable short- and medium-term outcomes from taTME, a Norwegian national study reported a high local recurrence rate of 9.5%. The characteristics of the recurrences included rapid, multifocal growth in the pelvis, which was quite different from recurrences following traditional transabdominal TME; thus, the Norwegian Colorectal Cancer Group reached a consensus for a temporary moratorium on the performance of taTME. To ensure acceptable baseline quality and patient safety, taTME should be performed by well-trained colorectal surgeons. Although the appropriate indications for taTME remain controversial, the transanal approach is extremely important as a means of goal setting in difficult TME cases and as an aid to the transabdominal approach in various types of extended pelvic surgeries. The benefits in transanal lateral lymph node dissection and pelvic exenteration are presented herein.

Total mesorectal excision (TME) for rectal cancer can be achieved using open (OpTME), laparoscopic (LapTME), robotic (RoTME), or transanal techniques (TaTME). However, the optimal approach for access remains controversial. The aim of this network meta-analysis was to assess operative and oncological outcomes of all four surgical techniques.

Ovid MEDLINE, EMBASE, and PubMed databases were searched systematically from inception to September 2020, for randomised controlled trials (RCTs) comparing any two TME surgical techniques. A network meta-analysis using a Bayesian random-effects framework and mixed treatment comparison was performed. Primary outcomes were the rate of clear circumferential resection margin (CRM), defined as > 1 mm from the closest tumour to the cut edge of the tissue, and completeness of mesorectal excision. Secondary outcomes included radial and distal resection margin distance, postoperative complications, locoregional recurrence, disease-free survival, and overall survival. Surface under cumulative ranking (SUCRA) was used to rank the relative effectiveness of each intervention for each outcome. The higher the SUCRA value, the higher the likelihood that the intervention is in the top rank or one of the top ranks.

Thirty-two RCTs with a total of 6151 patients were included. Compared with OpTME, there was no difference in the rates of clear CRM: LapTME RR = 0.99 (95% (Credible interval) CrI 0.97-1.0); RoTME RR = 1.0 (95% CrI 0.96-1.1); TaTME RR = 1.0 (95% CrI 0.96-1.1). There was no difference in the rates of complete mesorectal excision: LapTME RR = 0.98 (95% CrI 0.98-1.1); RoTME RR = 1.1 (95% CrI 0.98-1.4); TaTME RR = 1.0 (95% CrI 0.91-1.2). RoTME was associated with improved distal resection margin distance compared to other techniques (SUCRA 99%). LapTME had a higher rate of conversion to open surgery when compared with RoTME: RoTME RR = 0.23 (95% CrI 0.034-0.70). Length of stay was shortest in RoTME compared to other surgical approaches: OpTME mean difference in days (MD) 3.3 (95% CrI 0.12-6.0); LapTME MD 1.7 (95% CrI - 1.1-4.4); TaTME MD 1.3 (95% CrI - 5.2-7.4). There were no differences in 5-year overall survival (LapTME HR 1.1, 95% CrI 0.74, 1.4; TaTME HR 1.7, 95% CrI 0.79, 3.4), disease-free survival rates (LapTME HR 1.1, 95% CrI 0.76, 1.4; TaTME HR 1.1, 95% CrI 0.52, 2.4), or anastomotic leakage (LapTME RR = 0.92 (95% CrI 0.63, 1.1); RoTME RR = 1.0 (95% CrI 0.48, 1.8); TaTME RR = 0.53 (95% CrI 0.19, 1.2). The overall quality of evidence as per Grading of Recommendations Assessment, Development and Evaluation (GRADE) assessments across all outcomes including primary and secondary outcomes was deemed low.

In selected patients eligible for a RCT, RoTME achieved improved distal resection margin distance and a shorter length of hospital stay. No other differences were observed in oncological or recovery parameters between (OpTME), laparoscopic (LapTME), robotic (RoTME), or trans-anal TME (TaTME). However, the overall quality of evidence across all outcomes was deemed low.

Anus-preserving surgery in overweight patients with low rectal cancer has been a challenge due to the narrow operating space. Intersphincteric resection (ISR) was once a standard therapeutic option for low rectal cancer. The effectiveness of transanal total mesorectal excision (taTME) in treating this group of patients remains uncertain as a new surgical strategy. The aim of this study was to evaluate the short-term effects of taTME with ISR in overweight patients with low rectal cancer.

A total of 53 patients with low rectal cancer were treated with taTME in 31 cases and ISR in 22 cases. The surgery-related data, pathological manifestations of surgical specimens, postoperative recovery, and postoperative complications were compared.

Patients in both groups completed the surgery successfully. There were no significant differences in operative time, blood loss, anastomotic distance from the anal verge and ileostomy between the two groups (P > 0.05). TaTME group performed or virtually finished resection of the rectal mesentery, and no positive cases of Circumferential Resection Margin (CRM) or Distal Resection Margin (DRM) were detected in either group. The number of lymph nodes found in surgical specimens did not change significantly between the two groups (P = 0.391). In the subgroup analysis, however, more lymph nodes were detected in female patients undergoing taTME than in male patients (P = 0.028). The ISR group took less time to remove the drainage tubes (P = 0.013) and the same results were obtained in both groups of male patients in the subgroup analysis (P = 0.011). There were no statistically significant differences in time to start liquid diet, time to remove catheters, time to start flatus, time to begin ambulation, postoperative hospital stay, and readmission within 30 days after surgery between the two groups (P > 0.05). However, female patients in the taTME group were initiated ambulation earlier than males in the subgroup analysis (P = 0.034). The difference was insignificant in the occurrence of postoperative complications between the two groups (P > 0.05).

taTME is safe and feasible for the treatment of overweight patients with low rectal cancer.

Rectal gastrointestinal stromal tumors (GISTs) surgery is often challenging owing to the anatomical constraints of the narrow pelvis and tumor hugeness. Despite the increasing number of patients undergoing trans-anal total mesorectal excision (taTME) globally, the feasibility of trans-anal surgery with the taTME technique for rectal GISTs remains unclear. We aimed to evaluate the feasibility of trans-anal surgery with the taTME technique for rectal GISTs.

Using a prospectively collected database, we retrospectively analyzed the clinical findings, surgical outcomes, pathological outcomes, urinary and anal functions, and prognoses of patients who underwent trans-anal surgery with the taTME technique for primary rectal GISTs at the National Cancer Center Hospital East from September 2014 to March 2020.

Twenty-one patients with primary rectal GISTs were included in this study. The median distance from the anal verge to the lower edge of the tumor was 40 mm (range, 15-60 mm), and the median tumor size was 59 mm (range, 11-175 mm). Moreover, seven and 14 patients underwent one-team and two-team surgeries, respectively, with curative intent. Nineteen patients (90.5%) underwent anus-preserving surgery, and the urinary tracts were preserved in all cases. Two-team surgery showed a significantly lower blood loss volume and shorter operation time than one-team surgery (58 vs. 222 mL, P = 0.017; 184 vs 356 min, P = 0.041, respectively). The pathological negative-margin resection rate was 100%. During the follow-up period, no patient developed local GIST recurrence and one (4.8%) developed distant metastasis.

Trans-anal surgery with the taTME technique is feasible for rectal GISTs, and two-team surgery may be more advantageous than one-team surgery in terms of operation time and blood loss.

Malnutrition and deconditioning impact postoperative morbidity and mortality. Computed tomography (CT) body composition variables are used as markers of nutritional status and sarcopenia. The objective of this study is to evaluate the impact of sarcopenia, using CT variables, on postoperative outcomes following transanal total mesorectal excision (TaTME) for rectal cancer.

This was an institutional retrospective cohort analysis of consecutive rectal cancer patients who underwent TaTME between April 2014 and May 2020. Psoas muscle index (PMI) was calculated from diagnostic CT scans. Based on previous studies, patients in the lowest PMI tertile by gender were considered sarcopenic. Fisher's exact and Mann-Whitney U test were used to compare categorical and continuous variables, respectively. Readmission rates and postoperative complications were compared between groups. Backward stepwise logistic regression was used to determine the association between sarcopenia and 30-day postoperative complications.

85 patients were analyzed, of which 63% were male, with a median age of 59 (IQR: 51-65), and median BMI of 28 (IQR: 24-32). Of the entire cohort, 34% (n = 29) were sarcopenic (median PMI 5.39 IQR: 4.49-6.71). No significant difference in baseline characteristics between sarcopenic and nonsarcopenic patients were observed. 55% of sarcopenic patients experienced a complication within 30 days compared to 24% of nonsarcopenic patients (p = 0.01). 41% of sarcopenic patients required hospital readmission within 30 days compared to 17% of their nonsarcopenic counterparts (p = 0.014). Sarcopenic patients also experienced significantly higher rates of post-operative small bowel obstruction (10% vs. 0%, p = 0.04). Multivariable analyses identified that sarcopenic patients have a fourfold increase in odds of experiencing a 30-day postoperative complication (OR: 4.44, 95%CI: 1.6-12.4, p < 0.05) after adjusting for gender.

Preoperative sarcopenia is associated with increased 30-day postoperative complications following TaTME for rectal cancer. Postoperative complications can have serious oncologic implications by delaying adjuvant chemotherapy. Therefore, preoperative recognition of sarcopenia prior to undergoing TaTME for rectal cancer may provide an opportunity for early intervention with prehabilitation programs.

Since transanal total mesorectal excision (taTME) was introduced, it has become an important topic in rectal cancer treatment. Many previous studies reported positive relevant short-term results, histopathological results, and associated complications. Recently, concerns regarding the oncological safety of taTME have been raised due to reports showing high local recurrences (LR) rates. Therefore, this study aimed to compare the 3-year outcomes between taTME and laparoscopic total mesorectal excision (laTME) for mid-low rectal cancer.

A total of 104 patients who underwent taTME were matched with 208 patients treated by laTME. The primary endpoint was 3-year LR rate; secondary endpoints in this matched-cohort study included the perioperative outcomes and histopathological outcomes.

taTME was associated with lower permanent ostomy rate (1% vs 13.5%) and lower conversion rate (0% vs 3.4%) compared to laTME. A similar quality of resected specimens was detected for each group. In both groups, the local recurrence rate was 3.8%. Within 3 years after surgery, the disease-free survival (DFS) rates were 78.8% in the taTME group and 76.9% in the laTME group (P = 0.640), while the overall survival (OS) rates were 93.3% in the taTME group and 89.9% in the laTME group (P = 0.327).

No significant differences regarding 3-year local recurrence rate (3.8%) were observed in the taTME group compared to laTME group.

Transanal total mesorectal excision (TaTME) has the potential advantages for patients with low rectal cancer. The objective of this meta-analysis was to identify the pathologic outcomes between the TaTME and laparoscopic total mesorectal excision (LaTME) in rectal cancer.

The literature searches were conducted in PubMed, Cochrane Library, and EMBASE with English language restriction. The primary endpoint was circumferential margin (CRM), and the secondary endpoints were distal resection margin (DRM), mesorectal excision quality, and harvested lymph nodes.

Our research identified 1090 articles, and 26 studies met the inclusion criteria for the meta-analysis. The positive CRM was lower in the TaTME than the LaTME (OR = 0.72; 95% CI = 0.53, 0.98; P = 0.04). There was no significant difference in the positive CRM between the TaTME and LaTME published after 2016 (OR = 0.80; 95% CI = 0.57, 1.12; P = 0.19), prospective study (OR = 2.70; 95% CI = 0.51, 14.24; P = 0.24), respective study (OR = 0.76; 95% CI = 0.55, 1.04; P = 0.09), BMI > 26 (OR = 1.00; 95% CI = 0.63, 1.58; P = 0.98), or sample size > 100 (OR = 0.84; 95% CI = 0.57, 1.23; P = 0.38). In addition, there was no significant difference observed between the TaTME and LaTME in terms of DRM, mesorectum incompleteness, and harvested lymph nodes.

The TaTME is associated with lower positive CRM compared to the LaTME and similar pathologic outcomes including DRM, harvested lymph node, and mesorectal excision quality.

Evidence and practice recommendations on the use of transanal total mesorectal excision (TaTME) for rectal cancer are conflicting.

We aimed to summarize best evidence and develop a rapid guideline using transparent, trustworthy, and standardized methodology.

We developed a rapid guideline in accordance with GRADE, G-I-N, and AGREE II standards. The steering group consisted of general surgeons, members of the EAES Research Committee/Guidelines Subcommittee with expertise and experience in guideline development, advanced medical statistics and evidence synthesis, biostatisticians, and a guideline methodologist. The guideline panel consisted of four general surgeons practicing colorectal surgery, a radiologist with expertise in rectal cancer, a radiation oncologist, a pathologist, and a patient representative. We conducted a systematic review and the results of evidence synthesis by means of meta-analyses were summarized in evidence tables. Recommendations were authored and published through an online authoring and publication platform (MAGICapp), with the guideline panel making use of an evidence-to-decision framework and a Delphi process to arrive at consensus.

This rapid guideline provides a weak recommendation for the use of TaTME over laparoscopic or robotic TME for low rectal cancer when expertise is available. Furthermore, it details evidence gaps to be addressed by future research and discusses policy considerations. The guideline, with recommendations, evidence summaries, and decision aids in user-friendly formats can also be accessed in MAGICapp: https://app.magicapp.org/#/guideline/4494 .

This rapid guideline provides evidence-informed trustworthy recommendations on the use of TaTME for rectal cancer.

Solitary fibrous tumors require complete surgical resection to avoid recurrence. Large solitary fibrous pelvic tumors are difficult to resect completely with conventional surgical methods. We herein report a case in which a joint surgical approach was required for resection due to the location and size of tumor.

A 45-year-old man had a large solitary fibrous tumor in the pelvis, which extended into the left obturator foramen. The patient underwent tumor resection with vesico-prostatectomy, transanal total mesorectal excision, and opening of the foramen obturatum. The tumor was grossly resected completely. No recurrence was noted nine months after surgery.

A multidisciplinary team approach with transanal total mesorectal excision may provide complete resect of large pelvic solitary fibrous tumors.

Transanal total mesorectal excision (TaTME) was developed to overcome the technical challenges of a minimally invasive (ultra-) low anterior resection. This new technique has recently come under careful scrutiny as technical pitfalls were reported, in specific relation to the transanal approach. Patients are at risk for urologic lesions. Moreover, carbon dioxide embolism is a rare but potentially life-threatening complication. The benefit of TaTME from an oncological point of view has neither been clarified. Hypothetically, better visualization of the lower rectum could lead to better dissection and total mesorectal excision (TME) specimens, resulting in better oncologic results. Up until now, retrospective multicenter reports seem to show that short-term oncologic results are not inferior after TaTME as compared with after laparoscopic TME. Alarming reports have however been published from Norway suggesting a high incidence and particular multifocal pattern of early local recurrence. In this article, a balanced overview is given of the most important technical pitfalls and oncological concerns arising with this new procedure.

Transanal surgery has gained in popularity during the latter part of the last decade for both rectal cancer and benign disease. The current role for local excision of early rectal neoplastic lesions has expanded due to better understanding of risk factors for lymph node metastasis and heightened awareness for the long-term sequelae of radical surgery. Transanal resection of the rectum (both for cancer or inflammatory bowel diseases) has now been established as a successful procedure that overcomes some of the limitations of the abdominal approaches. Once the feasibility, safety, and the oncologic results of transanal minimally invasive approaches for patients with rectal cancer have been acknowledged, quality of life and functional outcomes have become increasingly important issues. This article provides an overview of the different techniques currently available for the minimally invasive transanal treatment of rectal lesions, particularly focusing on functional outcomes.

It is important to understand advances in treatment options for rectal cancer. We attempt to highlight advances in rectal cancer treatment in the form of a systematic review. Early-stage rectal cancer focuses on minimally invasive endoluminal surgery, with importance placed on patient selection as the driving factor for improved outcomes. To achieve a complete pathologic response, various neoadjuvant chemoradiation regimens have been employed. Short-course radiation therapy, total neoadjuvant chemotherapy, and others provide unique advantages with select patient populations best suited for each. With a clinical complete response, a "watch and wait" non-operative surveillance has been introduced with preliminary equivalency to radical resection. Various modalities for total mesorectal excision, such as robotic or transanal, have advantages and can be utilized in select patient populations. Tumors demonstrating solid organ or peritoneal spread, traditionally defined as unresectable lesions conveying a terminal diagnosis, have recently undergone advances in hepatic and pulmonary metastasectomy. Hepatic and pulmonary metastasectomy has demonstrated clear advantages in 5-year survival over standard chemotherapy. With the peritoneal spread of colorectal cancer, HIPEC with cytoreductive therapy has emerged as the preferred treatment. Understanding the various therapeutic interventions will pave the way for improved patient outcomes.

Since 2010, laparoscopic transanal total mesorectal excision (TaTME) has been increasingly used for low and very low rectal cancer. It is supposed to improve visibility and access to the dissection planes in the pelvis. This study reports on short- and long-term outcomes of the first 100 consecutive patients treated with TaTME in a certified German colorectal cancer center.

Data were derived from digital patient files and official cancer registry reports for patients with TaTME tumor surgery between July 2014 and January 2020. The primary outcome was the 3-year local recurrence rate and local recurrence-free survival (LRFS). Secondary endpoints included overall survival (OAS), disease-free survival (DFS), operation time, completeness of local tumor resection, lymph node resection, and postoperative complications. The Kaplan-Meier method was employed for the survival analyses; competing risks were considered in the time-to-event analysis.

During the observation period, the average annual operation time decreased from 272 to 178 min. Complete local tumor resection was achieved in 97% of the procedures. Major postoperative complications (Clavien-Dindo 3-4) occurred in 11% of the cases. At a median follow-up time of 2.7 years, three patients had suffered from a local recurrence. Considering competing risks, this corresponds to a 3-year cumulative incidence rate for local recurrence of 2.2% and a 3-year LRFS of 81.9%. 3-year OAS was 82.9%, and 3-year DFS was 75.7%.

TaTME is associated with favorable short and long-term outcomes. Since it is technically demanding, structured training programs and more research on the topic are indispensable.