Predictive Factors and Risk Model for Positive Circumferential Resection Margin Rate After Transanal Total Mesorectal Excision in 2653 Patients With Rectal Cancer

A comparison of whole-mount and conventional sections for pathological mesorectal extension and circumferential resection margin assessment after total mesorectal excision

INTRODUCTION

The objective of the study is to compare 2 techniques for histological handling of rectal cancer specimens, namely whole-mount in a large block vs conventional sampling using small blocks, for mesorectal pathological assessment of circumferential resection margin status and depth of tumor invasion into the mesorectal fat.

METHODS

This is a prospective study including 27 total mesorectal excision specimens of rectal cancer from patients treated for primary rectal carcinoma between 2020 and 2022 in a specialized multidisciplinary Colorectal Unit. For each total mesorectal excision specimen, 2 contiguous representative tumoral slices were selected and comparatively analyzed with whole-mount and small blocks macroscopic dissection techniques, enabling comparison between them in the same surgical specimen. The agreement between the 2 techniques to assess the distance of the tumor from the circumferential resection margin as well as the depth of tumor invasion was evaluated with the Student's t-test for paired samples, Pearson's correlation coefficient, and the Bland-Altman method comparison analysis.

RESULTS

Complete mesorectal excision was observed in 8% of cases. Circumferential resection margin involvement was observed in only one case (4 %). The whole-mount and small block techniques obtained similar results when we assessed the distance to the circumferential resection margin (t-test P = 0.8, r = 0.92) and the depth of mesorectal infiltration (t-test P = 0.6, r = 0.95).

CONCLUSIONS

Both gross dissection techniques (whole-mount vs multiple small cassettes) are equivalent and reliable to assess the distance to circumferential resection margin and the depth of mesorectal infiltration in the mesorectal fat in rectal cancer staging.

Oncologic outcomes following transanal total mesorectal excision: the United States experience

AIM

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.

METHODS

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.

RESULTS

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%).

CONCLUSION

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.

Predicting the Feasibility of Curative Resection in Low Rectal Cancer: Insights from a Prospective Observational Study on Preoperative Magnetic Resonance Imaging Accuracy

Background and Objectives: A positive pathological circumferential resection margin is a key prognostic factor in rectal cancer surgery. The point of this prospective study was to see how well different MRI parameters could predict a positive pathological circumferential resection margin (pCRM) in people who had been diagnosed with rectal adenocarcinoma, either on their own or when used together. Materials and Methods: Between November 2019 and February 2023, a total of 112 patients were enrolled in this prospective study and followed up for a 36-month period. MRI predictors such as circumferential resection margin (mCRM), presence of extramural venous invasion (mrEMVI), tumor location, and the distance between the tumor and anal verge, taken individually or combined, were evaluated with univariate and sensitivity analyses. Survival estimates in relation to a pCRM status were also determined using Kaplan-Meier analysis. Results: When individually evaluated, the best MRI predictor for the detection of a pCRM in the postsurgical histopathological examination is mrEMVI, which achieved a sensitivity (Se) of 77.78%, a specificity (Sp) of 87.38%, a negative predictive value (NPV) of 97.83%, and an accuracy of 86.61%. Also, the best predictive performance was achieved by a model that comprised all MRI predictors (mCRM+ mrEMVI+ anterior location+ < 4 cm from the anal verge), with an Se of 66.67%, an Sp of 88.46%, an NPV of 96.84%, and an accuracy of 86.73%. The survival rates were significantly higher in the pCRM-negative group (p < 0.001). Conclusions: The use of selective individual imaging predictors or combined models could be useful for the prediction of positive pCRM and risk stratification for local recurrence or distant metastasis.

Nomogram for predicting the surgical difficulty of laparoscopic total mesorectal excision and exploring the technical advantages of robotic surgery

Background

Total mesorectal excision (TME), represents a key technique in radical surgery for rectal cancer. This study aimed to construct a preoperative nomogram for predicting the surgical difficulty of laparoscopic total mesorectal excision (L-TME) and to investigate whether there were potential benefits of robotic TME (R-TME) for patients with technically challenging rectal cancer.

Methods

Consecutive mid-low rectal cancer patients receiving total mesorectal excision were included. A preoperative nomogram to predict the surgical difficulty of L-TME was established and validated. Patients with technically challenging rectal cancer were screened by calculating the prediction score of the nomogram. Then patients with technically challenging rectal cancer who underwent different types of surgery, R-TME or L-TME, were analyzed for comparison.

Results

A total of 533 consecutive patients with mid-low rectal cancer who underwent TME at a single tertiary medical center between January 2018 and January 2021 were retrospectively enrolled. Multivariable analysis demonstrated that mesorectal fat area, intertuberous distance, tumor size, and tumor height were independent risk factors for surgical difficulty. Subsequently, these variables were used to construct the nomogram model to predict the surgical difficulty of L-TME. The area under the receiver operating characteristic curve of the nomogram was 0.827 (95% CI 0.745 - 0.909) and 0.809 (95% CI 0.674- 0.944) in the training and validation cohort, respectively. For patients with technically challenging rectal cancer, R-TME was associated with a lower diverting ileostomy rate (p = 0.003), less estimated blood loss (p < 0.043), shorter procedure time (p = 0.009) and shorter postoperative hospital stay (p = 0.037).

Conclusion

In this study, we established a preoperative nomogram to predict the surgical difficulty of L-TME. Furthermore, this study also indicated that R-TME has potential technical advantages for patients with technically challenging rectal cancer.

Predicting Positive Radial Margin on Restaging MRI of Patients with Low Rectal Cancer: Can We Do Better?

Objective  The aim of this study was to characterize the tissue involving the margin and study if this information will affect margin prediction on restaging magnetic resonance imaging (MRI) in low rectal adenocarcinoma (LRC) patients treated with neoadjuvant long-course chemoradiotherapy (LCCRT). Methods  In this retrospective study of nonmetastatic LRC (distal margin <5 cm from the anal verge) treated with LCCRT followed by surgery, a radiologist blinded to outcome reread the restaging MRI and documented if the radial margin was involved by tumor, fibrosis, or mucin reaction using T2 high-resolution (HR) and diffusion-weighted imaging (DWI). The diagnostic performance of tumor-involving margin on restaging MRI was assessed using surgical histopathology as a reference. Interobserver agreement between three independent radiologists was assessed in a subset. Results  We included 133 patients (80 males and 53 females) with a mean (range) age of 44.7 (21-86) years and 82% of them had well or moderately differentiated adenocarcinoma. Baseline MRI showed T3 ( n  = 58) or T4 ( n  = 60) disease in 89% of the patients. The pathological margin was positive in 21% ( n  = 28) cases. In restaging MRI, the circumferential resection margin (CRM) ≤1 mm in 75.1% ( n  = 100) cases and MRI predicted tumor, fibrosis, and mucin reaction at the margin in 60, 34, and 6%, respectively, and histopathology showed tumor cells in 33, 14.7, and 16.6% of them, respectively. LRC with tumor-involving margin and bad response (MR tumor regression grade [mr-TRG] 3-5) on restaging MRI had fourfold increased risk of positive pathological circumferential resection margin (pCRM). There was moderate and fair inter-reader agreement for the tissue type involving the CRM ( κ  = 0.471) and mr-TRG ( κ  = 0.266), p  < 0.05. The use of both distance criteria and tumor-involving margins improved the diagnostic accuracy for margin prediction from 39 to 66% on restaging MRI. Conclusions  Margin prediction on restaging MRI can be improved by characterizing the tissue type involving the margin in low rectal cancer patients. The inter-reader agreement was moderate for determining the tissue type.

Surgical Outcomes, Long-Term Recurrence Rate, and Resource Utilization in a Prospective Cohort of 165 Patients Treated by Transanal Total Mesorectal Excision for Distal Rectal Cancer

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.

Automated high-throughput genome editing platform with an AI learning in situ prediction model

A great number of cell disease models with pathogenic SNVs are needed for the development of genome editing based therapeutics or broadly basic scientific research. However, the generation of traditional cell disease models is heavily dependent on large-scale manual operations, which is not only time-consuming, but also costly and error-prone. In this study, we devise an automated high-throughput platform, through which thousands of samples are automatically edited within a week, providing edited cells with high efficiency. Based on the large in situ genome editing data obtained by the automatic high-throughput platform, we develop a Chromatin Accessibility Enabled Learning Model (CAELM) to predict the performance of cytosine base editors (CBEs), both chromatin accessibility and the context-sequence are utilized to build the model, which accurately predicts the result of in situ base editing. This work is expected to accelerate the development of BE-based genetic therapies.

Incidence, predictors and prognostic implications of positive circumferential resection margin in colon cancer: A retrospective study in a Chinese high-volume cancer center

Positive circumferential resection margin (CRM) was associated with a higher recurrence rate and worse survival in rectal cancer. Predictors of CRM in rectal cancer have widely been investigated. Our study aims to determine the incidence, predictors and prognostic implications of positive CRM following colon cancer (CC) surgery in a Chinese high-volume cancer center. The clinicopathological features and oncological outcomes of CC patients undergoing surgery between January 2008 and December 2018 were identified from Fudan University Shanghai Cancer Center database. Positive CRM was defined as resection margin ≤1 mm. A total of 5268 stage I-IV CC patients were identified in our study, 108 (2.05%) of whom had positive CRM. Multivariate logistic analysis found that advanced N stage, distant metastases and poorly differentiated tumor had increased risk of positive CRM. After propensity score matching, the 5-year overall survival rates of the patients with positive and negative CRM were 33.2% and 39.8% (P=0.005), respectively. Multivariable COX regression model showed that positive CRM was an independent prognostic factor for OS in CC patients. The overall rate of positive CRM in our center is lower than that in western population. Several adverse pathological parameters deserve more attention to identify CC patients at a high risk of positive CRM. Adoption of appropriate surgical techniques and multidisciplinary treatment planning are expected to improve oncological outcomes for high selected CC patients with “high-risk” CRM involvement.

Trans-anal surgery with the taTME technique for rectal gastrointestinal stromal tumors: a retrospective study

PURPOSE

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Comparison between robotic-assisted and laparoscopic sphincter-preserving operations for ultra-low rectal cancer

Aim

Sphincter-preserving operations for ultra-low rectal cancer include low anterior and intersphincteric resection. In low anterior resection, the distal rectum is divided by a transabdominal approach, which is technically demanding. In intersphincteric resection, a perineal approach is used. We aimed to evaluate whether robotic-assisted surgery is technically superior to laparoscopic surgery for ultra-low rectal cancer. We compared the frequency of low anterior resection in cases of sphincter-preserving operations.

Method

We investigated 183 patients who underwent sphincter-preserving robotic-assisted or laparoscopic surgery for ultra-low rectal cancer (lower border within 5 cm of the anal verge) between April 2010 and March 2020. The frequency of low anterior resection was compared between laparoscopic and robotic-assisted surgeries. The clinicopathological factors associated with an increase in performing low anterior resection were analyzed by multivariate analyses.

Results

Overall, 41 (22.4%) and 142 (77.6%) patients underwent laparoscopic and robotic-assisted surgery, respectively. Patient characteristics were similar between the groups. Low anterior resection was done significantly more frequently in robotic-assisted surgery (67.6%) than in laparoscopic surgery (48.8%) (P = 0.04). Multivariate analyses showed that tumor distance from the anal verge (P < 0.01) and robotic-assisted surgery (P = 0.02) were significantly associated with an increase in the performance of low anterior resection. The rate of postoperative complications or pathological results was similar between the groups.

Conclusion

Compared with laparoscopic surgery, robotic-assisted surgery significantly increased the frequency of low anterior resection in sphincter-preserving operations for ultra-low rectal cancer. Robotic-assisted surgery has technical superiority over laparoscopic surgery for ultra-low rectal cancer treatment.

Effect of Tumor Location on Outcome After Laparoscopic Low Rectal Cancer Surgery: A Propensity Score Matching Analysis

BACKGROUND

Dissection of the distal anterolateral aspect of the mesorectum remains a surgical challenge for low rectal cancer, posing a higher risk of residual mesorectum, which might lead to the increased incidence of local recurrence for patients with anterior wall involvement.

OBJECTIVE

This study aimed to assess the effect of tumor location on outcome after laparoscopic low rectal cancer surgery.

DESIGN

This is a single-center, retrospective study.

SETTINGS

The study was conducted at West China Hospital in China.

PATIENTS

Patients with low rectal cancer who underwent laparoscopic total mesorectal excision from 2011 to 2016 were enrolled. Patients were divided into anterior and nonanterior groups according to tumor location. Propensity score matching analysis was used to reduce the selection bias.

MAIN OUTCOME MEASURES

The primary end point was local recurrence. The secondary end points included overall survival, disease-free survival, and the positive rate of circumferential resection margin.

RESULTS

A total of 404 patients were included, and 176 pairs were generated by propensity score matching analysis. Multivariate analysis showed that anterior location was an independent risk factor of local recurrence (HR, 12.6; p = 0.006), overall survival (HR, 3.0; p < 0.001), and disease-free survival (HR, 2.3; p = 0.001). For patients with clinical stage II/III or T3/4, anterior location remained a prognostic factor for higher local recurrence and poorer survival. Local recurrence was rare in patients with clinical stage II/III (1.4%) or T3/4 (1.5%) tumors that were not located anteriorly.

LIMITATIONS

This study was limited by its retrospective nature.

CONCLUSIONS

Anterior location is an independent risk factor of local recurrence, overall survival, and disease-free survival for low rectal cancer. More strict and selective use of neoadjuvant therapy should be considered for patients who have clinical stage II/III or T3/4 tumors that are not located anteriorly. A larger cohort study is warranted to validate the prognostic role of anterior location for low rectal cancer. See Video Abstract at http://links.lww.com/DCR/B622.

IMPACTO DE LA LOCALIZACIN DEL TUMOR EN EL RESULTADO POSTERIOR A CIRUGA LAPAROSCPICA DE CNCER DE RECTO INFERIOR UN PUNTAJE DE PROPENSIN POR ANLISIS DE CONCORDANCIA

ANTECEDENTES:La disección de la cara anterolateral distal del mesorrecto sigue siendo un desafío quirúrgico en el cáncer de recto inferior, constituyendo un alto riesgo de mesorrecto residual, que podría ocasionar una mayor incidencia de recurrencia local en pacientes con compromiso de la pared anterior.OBJETIVO:El objetivo del estudio fue evaluar el efecto de la localización del tumor en el resultado posterior a la cirugía laparoscópica de cáncer de recto inferior.DISEÑO:Estudio restrospectivo de un único centro.ÁMBITO:El estudio se realizó en el West China Hospital en China.PACIENTES:Pacientes con cáncer de recto inferior que se sometieron a excisión mesorrectal total laparoscópica entre 2011 y 2016. Los pacientes se dividieron en grupos, anterior y no anterior, según la localización del tumor. Se utilizó un puntaje de propensión por análisis de concordancia para reducir el sesgo de selección.PRINCIPALES VARIABLES EVALUADAS:El objetivo principal fue la recurrencia local. Los objetivos secundarios incluyeron la sobrevida global, la sobrevida libre de enfermedad y la tasa de positividad del margen de resección circunferencial.RESULTADOS:Se incluyeron un total de 404 pacientes y se generaron 176 pares mediante un puntaje de propensión por análisis de concordancia. El análisis multivariado mostró que la localización anterior era un factor de riesgo independiente de recidiva local (HR = 12,6, p = 0,006), sobrevida global (HR = 3,0, p <0,001) y sobrevida libre de enfermedad (HR = 2,3, p = 0,001). En pacientes con estadio clínico II /III o T3/4, la ubicación anterior continuó como un factor pronóstico para una mayor recurrencia local y una menor sobrevida. La recidiva local fue excepcional en pacientes con tumores en estadio clínico II / III (1,4%) o T3 / 4 (1,5%) que no estaban localizados hacia anterior.LIMITACIONES:Este estudio estuvo limitado por su carácter retrospectivo.CONCLUSIONES:La localización anterior es un factor de riesgo independiente de recidiva local, sobrevida global y sobrevida libre de enfermedad para el cáncer de recto inferior. Se debe considerar un uso más estricto y selectivo de la terapia neoadyuvante para pacientes en estadio clínico II / III o T3 /4 de tumores que no se localizan hacia anterior. Se justifica un estudio de cohorte más grande para validar el impacto pronóstico de una ubicación anterior del cáncer de recto inferior. Consulte Video Resumen en http://links.lww.com/DCR/B622. (Traducción-Dr. Lisbeth Alarcon-Bernes).

Feasibility of the semi-opened method of specimen resection for a circumferential resection margin in rectal cancer surgery: a multicenter study

PURPOSE

A circumferential resection margin (CRM) > 1 mm is a surrogate marker of oncologic outcomes in rectal cancer patients. In Japan, because the mesentery is removed from the rectum, the CRM cannot be measured. This multicenter prospective study evaluates the feasibility of a resected specimen processing method that allows CRM measurement.

METHODS

Fifty patients with rectal cancer were enrolled. Resected specimens were processed as previously reported. The primary outcomes were CRM measurement and the rate of CRM positivity. The secondary outcomes were the quality of total mesorectal excision, the possibility to visualize and sample the tumor, the number of harvested lymph nodes, and comparison between the pathological CRM and preoperative mesorectal fascia (MRF) involvement. This study was registered in the University Hospital Medical Information Network (UMIN) Clinical Trials Registry under identification number UMIN000031735.

RESULTS

The CRM was measurable in all patients and found to be positive in three (6%). We confirmed tumor localization, sampled the tumor, and measured the distal margin in all patients. A median of 20 lymph nodes were harvested. The concordance rate between preoperative MRF involvement and pathological CRM status was 90%.

CONCLUSION

A semi-opened rectal specimen with transverse slicing is a feasible method for measuring the CRM.

Limitations and Concerns with Transanal Total Mesorectal Excision for Rectal Cancer

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.

Clinical Status and Future Prospects of Transanal Total Mesorectal Excision

Low rectal cancer has always posed surgical challenges to gastrointestinal surgeons. Transanal total mesorectal excision (taTME) is a novel approach to radical resection for low rectal cancer. Compared with conventional laparoscopic TME (laTME), taTME is relevant to the benefits of better vision of the mesorectal plane, feasibility of operating in a narrow pelvis, and exact definition of distal resection margin, which may lead to a higher possibility of free circumferential resection margin, better quality of TME specimen, and lower conversion rate. Although there are concerns about its long-term oncological outcomes and complex learning curve, taTME is a promising alternative for rectal cancer. In this review, we discuss the application status and prospects of taTME.

Transanal versus laparoscopic total mesorectal excision: a comparative study of long-term oncological outcomes

BACKGROUND

Transanal total mesorectal excision (TaTME) is the most recent approach developed to improve pelvic dissection in surgery for mid and low rectal tumors. There are still inconsistencies regarding the technique's oncological results. The aim of this study was to analyze clinical and oncological outcomes of the learning curve of TaTME in comparison to laparoscopic TME (lapTME).

METHODS

Rectal cancer patients who had TaTME and lapTME in two Portuguese colorectal units between March 2016 and December 2018 were eligible. Primary endpoints were 5-year overall survival, disease-free survival, and local recurrence. Secondary endpoints were clinical and pathological outcomes.

RESULTS

Forty-four patients underwent TaTME (29 men) and 39 lapTME (27 men) with a median age of 69 and 66 (p = 0.093), respectively. No differences were observed concerning baseline characteristics, emphasizing their comparability. In the TaTME group, there were more hand-sewn anastomosis (0 lapTME versus 7 TaTME, p = 0.018) with significantly less distance to the dentate line (40 mm lapTME versus 20 mm TaTME, p = 0.005) and significantly more loop ileostomies performed (28 lapTME versus 41 TaTME, p = 0.001). There were no differences in post-operative mortality, morbidity, readmissions, and stoma closure. Groups were similar in relation to specimen quality, margins, and resectability; however, TaTME had a significantly higher node yield (14 lapTME versus 20 TaTME, p = 0.002). Finally, no disparities were noted in oncological outcomes, namely local and distant recurrence, 5-year overall survival, and disease-free survival.

CONCLUSIONS

Even with the disadvantage of the learning curve of a new technique, TaTME appears to be comparable to lapTME, with similar long-term oncological outcomes. It has, however, a demanding learning curve, significant risk for morbidity and should be used only for selected patients.

Laparoscopic Proctocolectomy With Transanal Total Mesorectal Excision for Ulcerative Colitis

Transanal total mesorectal excision (TaTME) refers to endoscopic retrograde total mesorectal excision and is becoming increasingly popular worldwide. TaTME improves surgical manipulation and minimizes the risk of local recurrence of rectal cancer by ensuring circumferential resection margins. TaTME is mainly indicated for patients in whom transabdominal approaches are expected to be technically challenging. We extended the indications for TaTME to include surgery for ulcerative colitis lesions that might be cancerous in the rectum. Here, we report a case of proctocolectomy with TaTME for ulcerative colitis. A 38-year-old woman who was receiving treatment for ulcerative colitis underwent a biopsy for random samples from the transverse colon to the rectum. Histopathological findings revealed noninvasive dysplasia with p53 overexpression, suggestive of cancer. We extended the indication of TaTME to surgery for ulcerative colitis. We formed two surgical teams and performed laparoscopic proctocolectomy with TaTME simultaneously. This simultaneous operation reduced the duration of the procedures in the present case. The patient was discharged without any complications and underwent loop ileostomy closure four months postoperatively. The patient recovered without significant loss of the anal sphincter function and is doing well four months after the second surgery. We propose laparoscopic proctocolectomy with TaTME to be conducted simultaneously by two teams as a safe and effective technique that is associated with a shorter operation time than that reported previously. Additionally, TaTME was useful in confirming the appropriate dissection layer as well as in surgical manipulation. Hence, TaTME could serve as a useful therapeutic option for ulcerative colitis surgery.

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 36 male) 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: postoperative morbidity (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.

The role of transanal total mesorectal excision

At inception, transanal total mesorectal excision (TaTME) was hypothesized to be a solution for several problems encountered in pelvic surgery, particularly for distal rectal cancer. The transanal part of the procedure is less hampered by patient related factors such as visceral obesity and a narrow bony pelvis and can thus overcome access and visualization problems encountered with a pure abdominal approach. Clearly, as for any new technique, a learning curve needs to be negotiated, ideally without unacceptable harm to patients. Once in experienced hands, TaTME might overcome challenges found in anatomically challenging rectal cancer patients as well as for other indications. The role of TaTME is not to replace, but rather complement its abdominal counterpart.

Influence of Minimally Invasive Resection Technique on Sphincter Preservation and Short-term Outcome in Low Rectal Cancer in the Netherlands

BACKGROUND

Transanal and robotic-assisted total mesorectal excision are techniques that can potentially overcome challenges encountered with a pure laparoscopic approach in patients with rectal cancer.

OBJECTIVE

The aim of this study was to evaluate the proportion and predictive factors of restorative procedures and subsequent short-term outcomes of 3 minimally invasive techniques to treat low rectal cancer.

DESIGN

This is a nationwide observational comparative registry study.

SETTINGS

Patients with rectal cancer were selected from the mandatory Dutch ColoRectal Audit.

PATIENTS

Patients with low rectal cancer (≤5 cm) who underwent curative minimally invasive total mesorectal excision between 2015 and 2018 were included.

MAIN OUTCOME MEASURES

The primary outcomes measured were the proportion of restorative procedure, positive circumferential resection margin, and postoperative complications.

RESULTS

A total of 3466 patients were included for analysis, of which 33% underwent a restorative procedure. Resections were performed laparoscopically in 2845 patients, transanally in 448 patients, and were robot-assisted in 173 patients, with a proportion of restorative procedures of 28%, 66%, and 40%. The transanal approach was independently associated with a restorative procedure (OR, 4.11; 95% CI, 3.21-5.26; p < 0.001). Independent risk factors for a nonrestorative procedure, irrespective of the surgical technique, were age >75 years, ASA physical status ≥3, BMI >30, history of abdominal surgery, clinical T4-stage, mesorectal fascia ≤1 mm, neoadjuvant therapy, and having a procedure in 2015 to 2016 versus 2017 to 2018. The circumferential resection margin involvement was similar for all 3 groups (5.4%, 5.1%, and 5.1%). Short-term postoperative complications were less favorable for the newer techniques than for the laparoscopic approach.

LIMITATIONS

This study was limited because of the registry's variables and different group sizes.

CONCLUSION

Patients with low rectal cancer in the Netherlands are more likely to receive a restorative procedure with a transanal approach, compared with a laparoscopic or robotic procedure. Short-term oncological outcomes are comparable between the 3 minimally invasive techniques. See Video Abstract at http://links.lww.com/DCR/B608.

INFLUENCIA DE LA TCNICA DE RESECCIN MINIMAMENTE INVASIVA CON PRESERVACIN DE ESFNTERES EN LA RESOLUCIN A CORTO PLAZO EN CANCER DE TERCIO INFERIOR DE RECTO EN LOS PASES BAJOS

ANTECEDENTES:La excisión mesorrectal transanal y asistida por robot son técnicas que potencialmente pueden superar algunos obstáculos que podemos encontrar en un abordaje exclusivamente laparoscópico en pacientes con cáncer de recto.OBJECTIVOS:El objetivo de este estudio es evaluar la proporción y los factores de predicción positivos de los procedimientos restauradores y los resultados subsecuentes a corto plazo de tres técnicas mínimamente invasivas para tratar el cáncer de tercio inferior de recto.DISEÑO:Es un estudio comparativo observacional del registro nacional.ESCENARIO:Pacientes con cáncer de recto seleccionados del Registro Oficial de la Auditoría Holandesa Colo-rectal.PACIENTGES:Pacientes con cáncer de tercio inferior de recto (≤5 centimetros) sometidos a excision mesorrectal total mínimamente invasiva curativa.PRINCIPALES PARAMETROS DE EFECTIVIDAD:Proporción de procedimientos restauradores, margen de resección circunferencial positivo y complicaciones postoperatorias.RESULTADOS:Se incluyeron un total de 3,466 pacientes para análisis, de los cuales 33% fueron sometidos a procedimiento restaurador. Las resecciones fueron laparoscópica en 2,845 pacientes, transanal en 448 y asistidas por robot en 173, con una proporción de procedimientos restauradores en 28%, 66% y 40% respectivamente. El abordaje transanal se correlacionó en forma independiente con el procedimiento restaurador (OR 4.11; 95% CI 4.11; 95% CI 3.21-5.26; p<0.001). Los factores de riesgo independientes para un procedimiento no restaurador, sin tomar en cuenta la técnica quirúrgica fueron: edad >75, American Society of Anesthesiologist ≥3, índice de masa corporal >30, antecedente de cirugía abdominal, Estadio clínico T4, fascia mesorrectal ≤1 millimetro, terapia neoadyuvante y haber sido sometido al procedimiento en 2015-2016 y no en 2017-2018. El margen circunferencial de resección involucrado fue similar para los tres grupos (5.4%, 5.1% y 5.1%). Las complicaciones postquirúrgicas a corto plazo fueron menos favorables para las técnicas nuevas comparadas con el abordaje laparoscópico.LIMTANTES:El estudio tiene la limitación de las variables dependientes del registro y la diferencia entre el número de pacientes en cada grupo.CONCLUSION:Los pacientes con cáncer de tercio inferior de recto en Holanda se tratan con mayor frecuencia mediante un procedimiento restaurador transanal en comparación con los abordajes laparoscópico o robótico. Los resultados favorables desde el punto de vista oncológico a corto plazo son comparables entre las tres técnicas de invasión mínima. Consulte Video Resumenhttp://links.lww.com/DCR/B608.

Transperineal minimally invasive abdominoperineal excision for rectal cancer based on anatomical analysis of the muscular structure

INTRODUCTION

Transperineal minimally invasive abdominoperineal excision (TpAPE) may help minimize surgical invasiveness and make it possible to perform two-team surgery, although this procedure is regarded as difficult. The anatomical structures are complicated and have not been clearly defined, particularly on the anterior side of the anorectal junction in men. We investigated the anatomical configuration around the anterior wall of the anorectal junction, focusing on the structure of the striated muscles, to establish a standard procedure for TpAPE.

METHODS

We scrutinized the T₂ -weighted MRI scans of 106 men, and two male cadavers were used to examine the muscular structure surrounding the anorectal junction. We established our standardized procedure for TpAPE based on these anatomical studies. We also analyzed the clinicopathological findings from five men who had undergone TpAPE at our institution.

RESULTS

Using MRI, we detected band-like muscles bilaterally, just medial to the puborectal muscle in all analyzed patients, which we termed the rectal anterolateral muscle. We also detected the muscles that may correspond to the rectal anterolateral muscle when inspecting the cadavers. The standardized TpAPE procedures were carried out uneventfully for the five cases, and intraoperative complications such as urethral injury and inadvertent rectal perforation did not occur.

CONCLUSION

We standardized the TpAPE procedure based on anatomical examination of the muscular structure around the anal canal. The findings can contribute to safe implementation of TpAPE.

Options for Low Rectal Cancer: Robotic Total Mesorectal Excision

Low rectal cancers (LRCs) may offer a difficult technical challenge even to experienced colorectal surgeons. Although laparoscopic surgery offers a superior exposure of the pelvis when compared with open approach, its role in rectal cancer surgery has been controversial. Robotic platforms are well suited for difficult pelvic surgery due to its three-dimensional visualization, degree of articulation of instruments, precise movements, and better ergonomics. The robot may be suitable especially in the anatomically narrow pelvis such as in male and obese patients. Meticulous dissection in critical steps, such as splenic flexure takedown, nerve-sparing mesorectal excision, and distal margin clearance, are potential technical advantages. In addition, robotic rectal resections are associated with lower conversion rates to open surgery, less blood loss, and shorter learning curve with similar short-term quality of life outcomes, similar rates of postoperative complications, and equivalent short-term surrogate outcomes compared with conventional laparoscopy. Robotic surgery approach, if used correctly, can enhance the skills and the capabilities of the well-trained surgeon during minimally invasive procedures for LRC.

Predictors of Positive Circumferential Resection Margin in Rectal Cancer: A Current Audit of the National Cancer Database

BACKGROUND

Positive circumferential resection margin is a predictor of local recurrence and worse survival in rectal cancer. National programs aimed to improve rectal cancer outcomes were first created in 2011 and continue to evolve. The impact on circumferential resection margin during this time frame has not been fully evaluated in the United States.

OBJECTIVE

The purpose of this study was to determine the incidence and predictors of positive circumferential resection margin after rectal cancer resection, across patient, provider, and tumor characteristics.

DESIGN

This was a retrospective cohort study.

SETTINGS

The study was conducted using the National Cancer Database, 2011-2016.

PATIENTS

Adults who underwent proctectomy for pathologic stage I to III rectal adenocarcinoma were included.

MAIN OUTCOME MEASURES

Rate and predictors of positive circumferential resection margin, defined as resection margin ≤1 mm, were measured.

RESULTS

Of 52,620 cases, circumferential resection margin status was reported in 90% (n = 47,331) and positive in 18.4% (n = 8719). Unadjusted analysis showed that patients with positive circumferential resection margin were more often men, had public insurance and shorter travel, underwent total proctectomy via open and robotic approaches, and were treated in Southern and Western regions at integrated cancer networks (all p < 0.001). Multivariate analysis noted that positive proximal and/or distal margin on resected specimen had the strongest association with positive circumferential resection margin (OR = 15.6 (95% CI, 13.6-18.1); p < 0.001). Perineural invasion, total proctectomy, robotic approach, neoadjuvant chemoradiation, integrated cancer network, advanced tumor size and grade, and Black race had increased risk of positive circumferential resection margin (all p < 0.050). Laparoscopic approach, surgery in North, South, and Midwest regions, greater hospital volume and travel distance, lower T-stage, and higher income were associated with decreased risk (all p < 0.028).

LIMITATIONS

This was a retrospective cohort study with limited variables available for analysis.

CONCLUSIONS

Despite creation of national initiatives, positive circumferential resection margin rate remains an alarming 18.4%. The persistently high rate with predictors of positive circumferential resection margin identified calls for additional education, targeted quality improvement assessments, and publicized auditing to improve rectal cancer care in the United States. See Video Abstract at http://links.lww.com/DCR/B584.

PREDICTORES PARA UN MARGEN POSITIVO DE RESECCIN CIRCUNFERENCIAL EN EL CNCER DE RECTO UNA AUDITORA VIGENTE DE LA BASE DE DATOS NACIONAL DE CANCER

ANTECEDENTES:El margen positivo de resección circunferencial es un predictor de recurrencia local y peor sobrevida en el cáncer de recto. Los programas nacionales destinados a mejorar los resultados del cáncer de recto se crearon por primera vez en 2011 y continúan evolucionando. La repercusión del margen de resección circunferencial durante este período de tiempo no se ha evaluado completamente en los Estados Unidos.OBJETIVO:Determinar la incidencia y los predictores para un margen positivo de resección circunferencial posterior a la resección del cáncer de recto, según las características del paciente, el proveedor y el tumor.DISEÑO:Estudio de cohorte retrospectivo.AMBITO:Base de datos nacional de cáncer, 2011-2016.PACIENTES:Adultos que se sometieron a proctectomía por adenocarcinoma de recto con un estadío por patología I-III.PRINCIPALES VARIABLES EVALUADAS:Tasa y predictores para un margen positivo de resección circunferencial, definido como margen de resección ≤ 1 mm.RESULTADOS:De 52,620 casos, la condición del margen de resección circunferencial se informó en el 90% (n = 47,331) y positivo en el 18.4% (n = 8,719). El análisis no ajustado mostró que los pacientes con margen positivo de resección circunferencial se presentó con mayor frecuencia en hombres, tenían un seguro social y viajes más cortos, se operaron de proctectomía total abierta y robótica, y fueron tratados en las regiones del sur y el oeste en redes integradas de cáncer (todos p <0,001). El análisis multivariado destacó que el margen proximal y / o distal positivo de la pieza resecada tenía la asociación más fuerte con el margen postivo de resección circunferencial (OR 15,6; IC del 95%: 13,6-18,1, p <0,001). La invasión perineural, la proctectomía total, el abordaje robótico, la quimioradioterapia neoadyuvante, la red de cáncer integrada, el tamaño y grado del tumor avanzado y la raza afroamericana tenían un mayor riesgo de un margen de una resección positiva circunferencial (todos p <0,050). El abordaje laparoscópico, la cirugía en las regiones Norte, Sur y Medio Oeste, un mayor volumen hospitalario y distancia de viaje, estadio T más bajo y mayores ingresos se asociaron con una disminución del riesgo (todos p <0,028).LIMITACIONES:Estudio de cohorte retrospectivo con variables limitadas disponibles para análisis.CONCLUSIONES:A pesar del establecimiento de iniciativas nacionales, la tasa de margen positivo de resección circunferencial continúa siendo alarmante, 18,4%. El índice continuamente elevado junto a los predictores de un margen positivo de resección circunferencial hace un llamado para una mayor educación, evaluaciones específicas de mejora de la calidad y difusión de las auditorías para mejorar la atención del cáncer de recto en los Estados Unidos. Vea el resumen de video en http://links.lww.com/DCR/B584. Consulte Video Resumen en http://links.lww.com/DCR/B584.

Local Recurrence and Disease-Free Survival After Transanal Total Mesorectal Excision: Results From the International TaTME Registry

BACKGROUND

The oncologic safety of transanal total mesorectal excision (TaTME) for rectal cancer has recently been questioned, with high local recurrence (LR) rates reported in Dutch and Norwegian experiences. The objective of this study was to evaluate the oncologic safety of TaTME in a large cohort of patients with primary rectal cancer, primarily in terms of LR, disease-free survival (DFS), and overall survival (OS).

PATIENTS AND METHODS

This was a prospective international registry cohort study, including all patients who underwent TaTME for primary rectal adenocarcinoma from February 2010 through December 2018. The main endpoints were 2-year LR rate, pattern of LR, and independent risk factors for LR. Secondary endpoints included 2-year DFS and OS rates. Kaplan-Meier survival analysis was used to calculate actuarial LR, DFS, and OS rates.

RESULTS

A total of 2,803 patients receiving primary TaTME were included, predominantly men (71%) with a median age of 65 years (interquartile ratio, 57-73 years). After a median follow-up of 24 months (interquartile ratio, 12-38 months), the 2-year LR rate was 4.8% (95% CI, 3.8%-5.8%) with a unifocal LR pattern in 99 of 103 patients (96%). Independent risk factors for LR were male sex, threatened resection margin on baseline MRI, pathologic stage III cancer, and a positive circumferential resection margin on final histopathology. The 2-year DFS and OS rates were 77% (95% CI, 75%-79%) and 92% (95% CI, 91%-93%), respectively.

CONCLUSIONS

This largest TaTME cohort to date supports the oncologic safety of the TaTME technique for rectal cancer in patients treated in units that contributed to an international registry, with an acceptable 2-year LR rate and a predominantly unifocal LR pattern.

The learning curve of transanal total mesorectal excision for rectal cancer is associated with local recurrence: results from a multicentre external audit

AIM

Transanal total mesorectal excision (TaTME) has been suggested as a potential solution for the resection of challenging mid and low rectal cancer. This relatively complex procedure has been implemented in many centres over the last years, despite the absence of long-term safety data. Recently, concern has arisen because of an increase in local recurrence in the implementation phase. The aim of this study was to assess the correlation between accumulated experience and local recurrences.

METHOD

An independent clinical researcher performed an external audit of consecutive series of all TaTME procedures in six centres in the Netherlands. Kaplan-Meier estimated local recurrence rates were calculated and multivariate Cox proportional hazards regression analysis performed to assess risk factors for local recurrence. Primary outcome was the local recurrence rate in the initial implementation (cases 1-10), continued adoption (cases 11-40) and prolonged experience (case 41 onward).

RESULTS

Six hundred and twenty-four consecutive patients underwent TaTME for rectal cancer with a median follow-up of 27 months (range 1-82 months). The estimated 2- and 3-year local recurrence rates were 4.6% and 6.6%, respectively. Cox proportional hazards regression revealed procedural experience to be an independent factor in multivariate analysis next to advanced stage (ycMRF+, pT3-4, pN+) and pelvic sepsis. Corrected analysis projected the 3-year local recurrence rates to be 9.7%, 3.3% and 3.5% for the implementation, continued adoption and prolonged experience cohorts, respectively.

CONCLUSION

This multicentre study shows a high local recurrence rate (12.5%) after implementation of TaTME which lowers to an acceptable rate (3.4%) when experience increases. Therefore, intensified proctoring and further precautions must be implemented to reduce the unacceptably high risk of local recurrence at units starting this technique.

Quantitative T2*-Weighted Imaging and Reduced Field-of-View Diffusion-Weighted Imaging of Rectal Cancer: Correlation of R2* and Apparent Diffusion Coefficient With Histopathological Prognostic Factors

Purpose

To assess T2*-weighted imaging (T2*WI) and reduced field-of-view diffusion-weighted Imaging (rDWI) derived parameters and their relationships with histopathological factors in patients with rectal cancer.

Methods

Fifty-four patients with pathologically-proven rectal cancer underwent preoperative T2*-weighted imaging and rDWI in this retrospective study. R2* values from T2*-weighted imaging and apparent diffusion coefficient (ADC) values from rDWI were compared in terms of different histopathological prognostic factors using student’s t-test or Mann-Whitney U-test. The correlations of R2* and ADC with prognostic factors were assessed by Spearman correlation analysis. The diagnostic performances of R2* and ADC were analyzed by receiver operating characteristic curves (ROC) separately and jointly.

Results

Significant positive correlation was found between R2* values and T stage, lymph node involvement, histological grades, CEA level, the presence of EMVI and tumor deposit (r = 0.374 ~ 0.673, p = 0.000–0.006), with the exception of CA19-9 level, CRM status and tumor involvement in the circumference lumen (TIL). Meanwhile, ADC values negatively correlated with almost all the prognostic factors (r = −0.588 to −0.299, p = 0.000–0.030), except CA19-9 level. The AUC range was 0.724–0.907 for R2* and 0.674–0.887 for ADC in discrimination of different prognostic factors. While showing the highest AUC of 0.913 (0.803–1.000) in differentiation of T stage, combination of R2* and ADC with reference to different prognostic factors did not significantly improve the diagnostic performance in comparison with individual R2*/ADC parameter.

Conclusions

R2* and ADC were associated with important histopathological prognostic factors of rectal cancer. R2* might act as additional quantitative imaging marker for tumor characterization of rectal cancer.

Systematic review of transanal total mesorectal excision literature according to the ideal framework: The evolution never ends

BACKGROUND

Designing studies to assess critically novel procedures can be challenging; thus, the process to achieve robust evidence is frequently problematic. The aim of this systematic review was to evaluate if literature on transanal total mesorectal excision is evolving according to the Idea, Development, Exploration, Assessment, and Long-term results framework.

METHODS

Literature on transanal total mesorectal excision was searched according to the preferred reporting items for systematic reviews and meta-analyses statement, and these variables were recorded: bibliometric data, design, corresponding author's nationality, number of patients enrolled, and Idea, Development, Exploration, Assessment, and Long-term results stages (stage 0, stage 1, stage 2, stage 3, and stage 4).

RESULTS

Out of 447 articles retrieved, 247 were selected (76.5% single center and 23.5% multicenter collaborations), including 35 reviews, 15 meta-analyses, 24 other publications, and 173 articles classified according to Idea, Development, Exploration, Assessment, and Long-term results stages (19 stage 0, 27 stage 1, 111 stage 2, 7 stage 3, and 9 stage 4). Overall, impact factor produced was 634.10. Reviewing corresponding authors' nationalities, 32 countries were identified, and the most reported were the United States, China, and the United Kingdom; nearly all were from the Northern Hemisphere. Publication of stage 3 and 4 articles started in 2014, whereas stage 0 and 1 articles were stably published over time. The number of patients increased in correspondence with the Idea, Development, Exploration, Assessment, and Long-term results stages (case series with >51 patients, respectively, 100.0% stage 3, 77.8% stage 4, and 33.3% stage 2, P = .005).

CONCLUSION

The number of stage 3 and 4 articles is still low; however, the technical innovation of transanal total mesorectal excision is a non-stopping process with preclinical studies stably published over time.

Short-term outcomes of medium-low rectal cancer treated by taTME and experience of 22 cases

BACKGROUND AND METHODS

Transanal total mesorectal excision (taTME) is a novel radical resection technique that may address the unsatisfactory functional and oncological outcomes of medium-low rectal cancers. Although its oncological safety remains unclear, taTME has demonstrable value in surgery, complications, and oncological outcomes. Here, we explore the short-term outcomes of rectal cancer after taTME and discuss the surgical experience. Twenty-two patients with medium-low rectal cancer who underwent taTME were retrospectively evaluated. Comprehensive demographic, oncological, and clinical data were analyzed and the perioperative state and postoperative follow-up were evaluated.

RESULTS

Over a median follow-up period of 24.4 (4-36) months, local recurrence occurred in one patient at 6 months postsurgery. Fecal incontinence was the most common postoperative complication, and 3-6 months of pelvic-floor-rehabilitation training greatly improved  anal function CONCLUSIONS: taTME achieved satisfactory short-term outcomes in oncological complications and postoperative functions. Accurate intraoperative anatomical location, identification of the rectovesical fascia, and neuroprotection are critical. However, this procedure has a steep learning curve, and large samples and multicenter studies are required to substantiate its effectiveness.

DISCUSSION

We retrospectively analyzed the oncological and functional prognosis of 22 patients with colorectal cancer undergoing taTME surgery and preliminarily concluded taTME can be regarded as a safe and feasible treatment.

Verification of data in a nationwide transanal total mesorectal excision registry in China

BACKGROUND AND OBJECTIVES

Transanal total mesorectal excision is a surgical procedure for mid- and low rectal cancer. The Chinese TaTME Registry Collaborative is a nationwide database collecting information on patients who have undergone this procedure.

METHODS

Centers were invited by the registry committee to participate in a three-part data audit project: remote audits for data completeness and deviation values, onsite source verification of data accuracy, and an online survey of the characteristics of data managers.

RESULTS

Twenty-three tertiary centers participated in this project. The median case volume registered by the centers was 51 (interquartile range, 25-89). The overall data completeness for 30 verified variables was 89.1%. Eight centers achieved a high data completeness rate (>95%). The source data of eight centers were verified onsite. The overall accuracy rate was 90.4% (85.3%-97.6% across centers). Postoperative complications, mortality, and proximal/distal resection margin involvement were accurately reported in >95% of cases. The data completeness rate was higher if the data manager was a surgeon/surgical resident (94.2% vs. 84.8%, p = 0.045).

CONCLUSIONS

The completeness and accuracy of the data in the Chinese TaTME Registry Collaborative are acceptable. The quality of the data is highest when entered by colorectal surgeons and residents.

Transanal Total Mesorectal Excision: Short-term Outcomes of 1283 Cases from a Nationwide Registry in China

BACKGROUND

Transanal total mesorectal excision is a promising surgical procedure for mid to low rectal cancer.

OBJECTIVE

This study aimed to determine the short-term outcomes of Chinese patients treated with transanal total mesorectal excision.

DESIGN

This was an observational study using data from an online registry system.

SETTING

Study participants were recruited from 40 different centers across 15 provinces in China.

PATIENTS

Patients with either benign or malignant rectal disease who underwent transanal total mesorectal excision procedure and were registered in the Chinese Transanal Total Mesorectal Excision Registry Collaborative from May 2010 to November 2019 were included.

INTERVENTION

Patients underwent transanal total mesorectal excision.

MAIN OUTCOME MEASURES

The primary outcomes measured were the postoperative complications and pathological outcomes.

RESULTS

In total, 1283 patients, comprising 888 men (69.2%) and 395 women (39.8%) with a median age of 61 (22-92) years and a median BMI of 23.6 (14.5-46.3) kg/m2, were analyzed. Among 40 participating centers, the average number of registered cases was 32.1±34.7, and 12 centers (30%) registered >40 cases in the registry. Among 849 patients with rectal cancer who underwent laparoscopic-assisted transanal total mesorectal excision, the conversion rate was 0.5% in the abdominal phase and 1.9% in the perineal phase. Three patients reported urethral injury (0.5%). The postoperative complication rate and the anastomotic leakage incidence were 18.4% and 5.8%. The quality of the total mesorectum excision specimens was found to be complete in 81.9% of patients. In addition, the positive circumferential resection margin rate was 2.8%.

LIMITATIONS

The primary limitation of this registry study was the high percentage of missing data (10.8% overall), and, for some of the analyzed variables, up to 35% of the data was missing. Postoperative complications were not monitored after discharge, resulting in a lower morbidity rate than the 30-day morbidity rate reported in other studies.

CONCLUSIONS

The short-term outcomes of patients who underwent transanal total mesorectal excision procedures in China were acceptable. See Video Abstract at http://links.lww.com/DCR/B414.

EXCISIN TOTAL DEL MESORRECTO POR VA TRANSANAL RESULTADOS A CORTO PLAZO DE CASOS DE UN REGISTRO NACIONAL EN CHINA

ANTECEDENTES:La excisión total del mesorrecto por vía transanal es un procedimiento quirúrgico prometedor para el cáncer de recto medio y bajo.OBJETIVO:Determinar los resultados a corto plazo de los pacientes chinos tratados con escisión mesorrectal total transanal.DISEÑO:Estudio observacional con datos de un sistema de registro en línea.AJUSTE:Los participantes del estudio fueron reclutados en 40 centros diferentes en 15 provincias de China.PACIENTES:Se incluyeron pacientes con enfermedad rectal benigna o maligna que se sometieron a una cirugía de excisión total del mesorrecto por vía transanal y que se registraron en el Registro Colaborativo de Excisión Total del Mesorrecto por vía Transanal en China desde mayo de 2010 hasta noviembre de 2019.INTERVENCIÓN:Excisión total delmesorrecto por vía transanal.PRINCIPALES MEDIDAS DE RESULTADO:Complicaciones postoperatorias y resultados patológicos.RESULTADOS:Fueron analizados un total de 1.283 pacientes, que comprendían 888 hombres (69,2%) y 395 mujeres (39,8%) con una mediana de edad de 61 (22-92) años y una mediana de índice de masa corporal de 23,6 (14,5-46,3) kg / m2. Entre los 40 centros participantes, el promedio de casos registrados fue de 32,1 ± 34,7, y 12 centros (30%) inscribieron > 40 casos en el registro. Entre 849 pacientes con cáncer de recto que se sometieron a excisión total del mesorrecto pééor vía transanal asistida por laparoscopia, la tasa de conversión fue del 0,5% en la fase abdominal y del 1,9% en la fase perineal. Tres pacientes refirieron una lesión uretral (0,5%). La tasa de complicaciones posoperatorias y la incidencia de fuga anastomótica fueron del 18,4% y el 5,8%, respectivamente. La calidad de las muestras de excisión total del mesorrecto se evaluó como completa en el 81,9% de los pacientes. Además, la tasa de margen de resección circunferencial positiva fue del 2,8%.LIMITACIONES:La principal limitación del presente estudio de registros fue el alto porcentaje de datos faltantes (10,8% en general), y para algunas de las variables analizadas, faltaba hasta el 35% de los datos. Las complicaciones postoperatorias no fueron verificadas después del alta, lo que resultó en una tasa de morbilidad más baja que la tasa de morbilidad a 30 días informada en otros estudios.CONCLUSIONES:Los resultados a corto plazo de los pacientes que se sometieron al procedimiento de excisión total del mesorrecto por vía transanal en China fueron aceptables. Consulte Video Resumen en http://links.lww.com/DCR/B414. (Traducción-Dr. Xavier Delgadillo).

Association of Transanal Total Mesorectal Excision With Local Recurrence of Rectal Cancer

IMPORTANCE

Proponents of novel transanal total mesorectal excision (TME) suggest the procedure overcomes the technical and oncologic challenges of conventional approaches for treating rectal cancer. Recently, however, there has been controversy regarding the oncologic safety of the procedure.

OBJECTIVE

To assess the association of transanal TME with the incidence of local recurrence (LR) of cancer and the probability of remaining free of LR during follow-up.

DESIGN, SETTING, AND PARTICIPANTS

This multicenter cohort study used data from 8 high-volume rectal cancer academic institutions from across Canada on all consecutive patients with primary rectal cancer treated by transanal TME at the participating centers. The study was conducted between January 2014 and December 2018, and data were analyzed from April 1, 2020, to September 15, 2020.

EXPOSURE

Transanal TME.

MAIN OUTCOMES AND MEASURES

The incidence of LR was reported as a direct measure of quality of resection. The cumulative probability of LR- and systemic recurrence (SR)-free survival at 36 months was estimated. Local recurrence and SR were defined as radiologic or endoscopic evidence of 1 or more new lesions in or outside the pelvis, respectively, documented during surveillance after the removal of the primary tumor.

RESULTS

Of 608 total patients included in the analysis, 423 (69.6%) were male; the median age was 63 years (interquartile range [IQR], 54-70 years). Local recurrence was identified in 22 patients (3.6%) after a median follow-up of 27 months (IQR, 18-38 months). The median time to LR was 13 months (IQR, 9-19 months). Sixteen of the 22 patients with LR (72.7%) were male, 14 (63.6%) received neoadjuvant chemoradiation, and 12 (54.5%) had American Joint Committee on Cancer stage III disease. Of those with LR, 16 (72.7%) had a negative circumferential radial margin and 20 (90.9%) had a negative distal resection margin, 2 (9.1%) experienced conversion to open surgery, and 15 (68.2%) also developed SR. The probability of LR-free survival at 36 months was 96% (95% CI, 94%-98%). According to the Cox proportional hazards regression model, the hazard ratio of LR was estimated to be 4.2 (95% CI, 2.9-6.2) times higher among patients with a positive circumferential radial margin than among those with a negative circumferential radial margin.

CONCLUSIONS AND RELEVANCE

In this cohort study, transanal TME performed by experienced surgeons was associated with an incidence of LR and SR that is in line with the published literature on open and laparoscopic TME, suggesting that transanal TME may be an acceptable approach for management of rectal cancer.

Laparoscopic versus open rectal resection: a 1:2 propensity score-matched analysis of oncological adequateness, short- and long-term outcomes

BACKGROUND

Laparoscopic resections for rectal cancer are routinely performed in high-volume centres. Despite short-term advantages have been demonstrated, the oncological outcomes are still debated. The aim of this study was to compare the oncological adequateness of the surgical specimen and the long-term outcomes between open (ORR) and laparoscopic (LRR) rectal resections.

METHODS

Patients undergoing laparoscopic or open rectal resections from January 1, 2013, to December 31, 2019, were enrolled. A 1:2 propensity score matching was performed according to age, sex, BMI, ASA score, comorbidities, distance from the anal verge, and clinical T and N stage.

RESULTS

Ninety-eight ORR were matched to 50 LRR. No differences were observed in terms of operative time (224.9 min. vs. 230.7; p = 0.567) and postoperative morbidity (18.6% vs. 20.8%; p = 0.744). LRR group had a significantly earlier soft oral intake (p < 0.001), first bowel movement (p < 0.001), and shorter hospital stay (p < 0.001). Oncological adequateness was achieved in 85 (86.7%) open and 44 (88.0%) laparoscopic resections (p = 0.772). Clearance of the distal (99.0% vs. 100%; p = 0.474) and radial margins (91.8 vs. 90.0%, p = 0.709), and mesorectal integrity (94.9% vs. 98.0%, p = 0.365) were comparable between groups. No differences in local recurrence (6.1% vs.4.0%, p = 0.589), 3-year overall survival (82.9% vs. 91.4%, p = 0.276), and disease-free survival (73.1% vs. 74.3%, p = 0.817) were observed.

CONCLUSIONS

LRR is associated with good postoperative results, safe oncological adequateness of the surgical specimen, and comparable survivals to open surgery.

Trans-anal total mesorectal excision in low rectal cancers: Preliminary oncological results of a comparative study

OBJECTIVE

The management of lower rectal cancers is a therapeutic challenge both from the oncological and functional viewpoints. The aim of this study is to assess the oncological results and postoperative morbidity after transanal total mesorectal excision (TaTME) for low rectal cancer.

MATERIAL AND METHODS

In this monocentric retrospective study, we compared the quality of carcinologic resection and the morbidity-mortality between a group of 20 patients undergoing TaTME and 21 patients treated by abdomino-perineal resection (APR) between 2016 to 2019.

RESULTS

More patients had a positive circumferential resection margin (CRM) (≤1mm) in the APR group (47.6% vs. 5%; P<0.0036). The difference in the rates of grades I-II and III-IV complications (Clavien-Dindo classification) between the two groups was not statistically significant (50% vs. 57.1% and 5% vs. 9.5% in TaTME and APR, respectively; P=0.7579, P=1.00). The median follow-up was longer in the TaTME group (20 months vs. 11 months; P=0.58). The local recurrence rate did not differ between the two groups (5% vs. 4.8%; P=1.00) CONCLUSION: TaTME provides a reliable total mesorectal resection with an acceptable CRM. However, like any new technique, it requires experience and the learning curve is long.

Transanal total mesorectal excision achieves equivalent oncologic resection compared to laparoscopic approach, but with functional consequences

BACKGROUND

This study compared transanal total mesorectal excision (taTME) to laparoscopic total mesorectal excision (laTME) for the treatment of low rectal cancer. Adequacy of oncologic resection as well as postoperative outcomes were analyzed.

METHODS

We retrospectively reviewed all proctectomy for low rectal cancer by a single surgeon at our institution from January 2014 to September 2019.

RESULTS

There were 20 taTME and 30 laTME patients. TaTME patients had more distal tumors with no difference in pathologic resection margins or frequency of positive distal margin. Operative times were longer for taTME, but there were no differences in short-term outcomes or complications. TaTME patients had a higher rate of postoperative fecal incontinence.

CONCLUSION

TaTME may be a good option for the most distal tumors, when distal margins may be compromised. TaTME provides equivalent oncologic resection, but there is a higher incidence of postoperative fecal incontinence.

Early Experience With Transanal Total Mesorectal Excision Compared With Laparoscopic Total Mesorectal Excision for Rectal Cancer: A Propensity Score-Matched Analysis

BACKGROUND

Laparoscopic total mesorectal excision is widely used for rectal cancers; however, it is sometimes challenging, especially in obese patients with low tumors, particularly after chemoradiotherapy. Transanal total mesorectal excision was developed to overcome these limitations in terms of visualization, dissection, and stapling.

OBJECTIVE

The purpose of this study was to compare the pathologic and early oncologic outcomes of the laparoscopic and transanal approaches.

DESIGN

This was a retrospective comparative study using propensity score-matched analysis.

SETTING

The study was conducted at a tertiary hospital specializing in oncology.

PATIENTS

In total, 722 inpatients who underwent total mesorectal excision for rectal cancer from January 2014 to December 2017 were included.

INTERVENTIONS

Laparoscopic (N = 514) and transanal (N = 208) total mesorectal excision were performed.

MAIN OUTCOME MEASURES

The primary outcome was pathologic outcome including circumferential and distal resection margin involvement. The secondary outcomes were intraoperative and postoperative complications and overall survival, recurrence-free survival, and local recurrence rates.

RESULTS

The 2 groups of the cohort had several differences; thus, we performed propensity score matching. The circumferential resection margin was involved in 13.4% and 12.9% of the laparoscopic and transanal groups (p = 0.88). The distal resection margin was involved in 1% and 3% of the laparoscopic and transanal groups (p = 0.28). Complete or nearly complete total mesorectal excision was 98.0% and 96.5% in the laparoscopic and transanal groups (p = 0.41). Postoperative complications with Clavien-Dindo grade III or higher did not differ significantly between groups (p = 0.54) but were significantly higher in patients with tumors <5 cm from the anal verge who underwent laparoscopy (laparoscopic group = 11.9%; transanal group = 1.7%; p = 0.04). There were no statistical differences in the 3-year overall survival, recurrence-free survival, or local recurrence rates between groups.

LIMITATIONS

This was a retrospective study design with a short follow-up period.

CONCLUSIONS

Early experience with the transanal approach showed similar pathologic outcomes as those of conventional laparoscopy; hence, it should be considered as a surgical option for lower rectal cancer. See Video Abstract at http://links.lww.com/DCR/B352. EXPERIENCIA TEMPRANA CON LA ESCISIÓN MESORRECTAL TOTAL TRANSANAL EN COMPARACIÓN CON LA ESCISIÓN MESORRECTAL TOTAL LAPAROSCÓPICA PARA EL CÁNCER DE RECTO: UN ANÁLISIS DE PUNTUACIÓN DE PROPENSIÓN: La escisión mesorrectal total laparoscópica se usa ampliamente para los cánceres rectales; Sin embargo, a veces es un desafío, especialmente en pacientes obesos con tumores bajos, particularmente después de la quimiorradioterapia. La escisión mesorrectal total transanal se desarrolló para superar estas limitaciones en términos de visualización, disección y grapado.Comparar los resultados patológicos y oncológicos precoces de los enfoques laparoscópico y transanal.estudio comparativo retrospectivo con puntaje de propensión-análisis emparejadoHospital terciario especializado en oncología.En total, se incluyeron 722 pacientes hospitalizados que se sometieron a una escisión mesorrectal total por cáncer rectal desde Enero de 2014 hasta Diciembre de 2017.Se realizó escisión mesorrectal total laparoscópica (n = 514) y transanal (n = 208).El resultado primario fue el resultado patológico, incluyendo el involucramiento del margen de resección circunferencial y distal. Los resultados secundarios fueron complicaciones intraoperatorias, postoperatorias y supervivencia general, supervivencia libre de recurrencia y tasas de recurrencia local.Los dos grupos de la cohorte tuvieron varias diferencias; así, realizamos un emparejamiento de puntuación de propensión. El margen de resección circunferencial estuvo involucrado en 13.4% y 12.9% de los grupos laparoscópico y transanal, respectivamente (p = 0.88). El margen de resección distal estuvo involucrado en 1% y 3% de los grupos laparoscópico y transanal, respectivamente (p = 0.28). La escisión mesorrectal total completa o casi completa fue de 98.0% y 96.5% en los grupos laparoscópico y transanal, respectivamente (p = 0.41). Las complicaciones postoperatorias con Clavien-Dindo grado ≥ III no difirieron significativamente entre los grupos (p = 0,54), pero fueron significativamente mayores en pacientes con tumores de < 5 cm del borde anal que se sometieron a laparoscopia (grupo laparoscópico, 11,9%; grupo transanal, 1,7%; p = 0,04). No hubo diferencias estadísticas en la supervivencia general a 3 años, la supervivencia libre de recurrencia y las tasas de recurrencia local entre los grupos.Diseño de estudio retrospectivo, corto período de seguimiento.La experiencia temprana con el enfoque transanal mostró resultados patológicos similares a los de la laparoscopia convencional; por lo tanto, debe considerarse como una opción quirúrgica para el cáncer rectal mas bajo. Consulte Video Resumen en http://links.lww.com/DCR/B352. (Traducción-Dr Yesenia Rojas-Khalil).

Comparison of the perioperative outcomes of laparoscopic surgery, robotic surgery, open surgery, and transanal total mesorectal excision for rectal cancer: An overview of systematic reviews

Regarding the surgical approaches for rectal cancer, many techniques have been reported in randomized controlled trials, meta-analyses, and reviews of comparisons between two techniques, e.g. open surgery vs laparoscopic surgery, laparoscopic surgery vs robotic surgery, or laparoscopic surgery vs transanal total mesorectal excision. Since robotic surgery and transanal total mesorectal excision were developed after laparoscopic surgery had become an established minimally invasive technique, they have each been compared with laparoscopic surgery. Therefore, a review was performed to compare the surgical outcomes of robotic surgery and transanal total mesorectal excision, and to perform such comparisons among ≥3 of the above mentioned approaches, in the expectation that this review will serve as a reference for aiding treatment selection in future. The results of the current review suggest that all of the examined procedures have advantages and disadvantages, but that there are no decisive factors that could be used to select one procedure over any other. At the present time it cannot be demonstrated that laparoscopic surgery, robotic surgery, transanal total mesorectal excision, or open surgery is superior to the other techniques, and it is important to select the best technique for each patient from among those that a surgeon can perform. It is also important to maintain a flexible attitude that allows new techniques to be adopted as needed in the future.

Transanal total mesorectal excision: 3-year oncological outcomes

BACKGROUND

Rectal cancer treatment has evolved with the implementation of new surgical techniques. Transanal total mesorectal excision (TaTME) is the most recent approach developed to facilitate pelvic dissection of mid- and distal rectal tumours. The purpose of this study was to analyse the short- and mid-term oncological outcomes of TaTME.

METHODS

A study was conducted on patients treated with TaTME for rectal cancer at two colorectal units in Portugal between March 2016 and December 2018. Clinical, pathological and oncological data were retrospectively analysed. Primary endpoints were 3-year overall survival, disease-free survival and local recurrence. Secondary endpoints were clinical and pathological outcomes.

RESULTS

Fifty patients (31 males, [62%], median age 66 years [range 40-85 years]) underwent TaTME, 49 (98%) for malignant and 1 (2%) for benign disease. There were no cases of conversion, 49 (98%) patients had complete or near-complete mesorectum, all the resections were R0 with adequate distal and circumferential margins. With a median follow-up of 36 months, there were 2 cases (4%) of local recurrence and 3-year estimated overall survival and disease-free survival were 90% and 79%, respectively.

CONCLUSIONS

TaTME can provide safe mid-term oncological outcomes, similar to what has been published for classic and laparoscopic TME. Our results also show how demanding this novel approach can be and the consequent need for audited data and standardized implementation.

Preoperative predictive risk to cancer quality in robotic rectal cancer surgery

BACKGROUND

Circumferential resection margin (CRM) involvement is widely considered the strongest predictor of local recurrence after TME. This study aimed to determine preoperative factors associated with a higher risk of pathological CRM involvement in robotic rectal cancer surgery.

METHODS

This was a retrospective review of a prospectively maintained database of consecutive adult patients who underwent elective, curative robotic low anterior or abdominoperineal resection with curative intent for primary rectal adenocarcinoma in a tertiary referral cancer center from March 2012 to September 2019. Pretreatment magnetic resonance imaging (MRI) reports were reviewed for all the patients. Risk factors for pathological CRM involvement were investigated using Firth's logistic regression and a predictive model based on preoperative radiological features was formulated.

RESULTS

A total of 305 patients were included, and 14 (4.6%) had CRM involvement. Multivariable logistic regression found both T3 >5 mm (OR 6.12, CI 1.35-36.44) and threatened or involved mesorectal fascia (OR 4.54, CI 1.33-17.55) on baseline MRI to be preoperative predictors of pathologic CRM positivity, while anterior location (OR 3.44, CI 0.72-33.13) was significant only on univariate analysis. The predictive model showed good discrimination (area under the receiver-operating characteristic curve >0.80) and predicted a 32% risk of positive CRM if all risk factors were present.

CONCLUSION

Patients with pre-operatively assessed threatened radiological margin, T3 tumors with greater than 5 mm extension and anterior location are at risk for a positive CRM. The predictive model can preoperatively estimate the CRM positivity risk for each patient, allowing surgeons to tailor management to improve oncological outcomes.

Transperineal minimally invasive APE: preliminary outcomes in a multicenter cohort

Background

Abdominoperineal excision (APE) for rectal cancer is associated with a relatively high risk of positive margins and postoperative morbidity, particularly related to perineal wound healing problems. It is unknown whether the use of a minimally invasive approach for the perineal part of these procedures can improve postoperative outcomes without oncological compromise. The aim of this study was to evaluate the feasibility of minimally invasive transperineal abdominoperineal excision (TpAPE)

Methods

This multicenter retrospective cohort study included all patients having TpAPE for primary low rectal cancer. The primary endpoint was the intraoperative complication rate. Secondary endpoints included major morbidity (Clavien–Dindo ≥ 3), histopathology results, and perineal wound healing.

Results

A total of 32 TpAPE procedures were performed in five centers. A bilateral extralevator APE (ELAPE) was performed in 17 patients (53%), a unilateral ELAPE in 7 (22%), and an APE in 8 (25%). Intraoperative complications occurred in five cases (16%) and severe postoperative morbidity in three cases (9%). There were no perioperative deaths. A positive margin (R1) was observed in four patients (13%) and specimen perforation occurred in two (6%). The unilateral extralevator TpAPE group had worse specimen quality and a higher proportion of R1 resections than the bilateral ELAPE or standard APE groups. The rate of uncomplicated perineal wound healing was 53% (n = 17) and three patients (9%) required surgical reintervention.

Conclusions

TpAPE seems to be feasible with acceptable perioperative morbidity and a relatively low rate of perineal wound dehiscence, while histopathological outcomes remain suboptimal. Additional evaluation of the viability of this technique is needed in the form of a prospective trial with standardization of the procedure, indication, audit of outcomes and performed by surgeons with vast experience in transanal total mesorectal excision.