Comparing short-term outcomes of robot-assisted and conventional laparoscopic total mesorectal excision surgery for rectal cancer in elderly patients

BACKGROUND Da Vinci Robotics-assisted total mesorectal excision(TME)surgery for rectal cancer is becoming more widely used.There is no strong evidence that roboticassisted surgery and laparoscopic surgery have similar outcomes in elderly patients with TME for rectal cancer.AIM To determine the improved oncological outcomes and short-term efficacy of robot-assisted surgery in elderly patients undergoing TME surgery.METHODS A retrospective study of the clinical pathology and follow-up of elderly patients who underwent TME surgery at the Department of Gastrointestinal Oncology at the Affiliated Hospital of Nanjing University of Chinese Medicine was conducted from March 2020 through September 2023.The patients were divided into a robotassisted group(the R-TME group)and a laparoscopic group(the L-TME group),and the short-term efficacy of the two groups was compared.RESULTS There were 45 elderly patients(≥60 years)in the R-TME group and 50 elderly patients(≥60 years)in the L-TME group.There were no differences in demographics,conversion rates,or postoperative complication rates.The L-TME group had a longer surgical time than the R-TME group[145(125,187.5)vs 180(148.75,206.25)min,P=0.005),and the first postoperative meal time in the L-TME group was longer than that in the R-TME(4 vs 3 d,P=0.048).Among the sex and body mass index(BMI)subgroups,the R-TME group had better out-comes than did the L-TME group in terms of operation time(P=0.042)and intraoperative assessment of bleeding(P=0.042).In the high BMI group,catheter removal occurred earlier in the R-TME group than in the L-TME group(3 vs 4 d,P=0.001),and autonomous voiding function was restored.CONCLUSION The curative effect and short-term efficacy of robot-assisted TME surgery for elderly patients with rectal cancer are similar to those of laparoscopic TME surgery;however,robotic-assisted surgery has better short-term outcomes for individuals with risk factors such as obesity and pelvic stenosis.Optimizing the learning curve can shorten the operation time,reduce the recovery time of gastrointestinal function,and improve the prognosis.

Beyond total mesorectal excision: The emerging role of minimally invasive surgery for locally advanced rectal cancer

Multivisceral resection and/or pelvic exenteration represents the only potential curative treatment for locally advanced rectal cancer(LARC);however,it poses significant technical challenges,which account for the high risk of morbidity and mortality associated with the procedure.As complete histopathologic resection is the most important determinant of patient outcomes,LARC often requires an extended resection beyond the total mesorectal excision plane to obtain clear re-section margins.In an era when laparoscopic surgery and robot-assisted surgery are becoming commonplace,the optimal approach to extensive pelvic inter-ventions remains controversial.However,acceptance of the suitability of mini-mally invasive surgery is slowly gaining traction.Nonetheless,there is still a lack of evidence in the literature about minimally invasive approaches in multiple and extensive surgical resections,highlighting the need for research studies to explore,validate,and develop this issue.This editorial aims to provide a critical overview of the currently available applications and challenges of minimally invasive abdo-minopelvic surgery for LARC.Furthermore,we discuss recent developments in the field of robotic surgery for LARC,with a specific focus on new innovations and emerging frontiers.

Use of artificial intelligence in total mesorectal excision in rectal cancer surgery: State of the art and perspectives

BACKGROUND Colorectal cancer is a major public health problem,with 1.9 million new cases and 953000 deaths worldwide in 2020.Total mesorectal excision(TME)is the standard of care for the treatment of rectal cancer and is crucial to prevent local recurrence,but it is a technically challenging surgery.The use of artificial intelligence(AI)could help improve the performance and safety of TME surgery.AIM To review the literature on the use of AI and machine learning in rectal surgery and potential future developments.METHODS Online scientific databases were searched for articles on the use of AI in rectal cancer surgery between 2020 and 2023.RESULTS The literature search yielded 876 results,and only 13 studies were selected for review.The use of AI in rectal cancer surgery and specifically in TME is a rapidly evolving field.There are a number of different AI algorithms that have been developed for use in TME,including algorithms for instrument detection,anatomical structure identification,and image-guided navigation systems.CONCLUSION AI has the potential to revolutionize TME surgery by providing real-time surgical guidance,preventing complic-ations,and improving training.However,further research is needed to fully understand the benefits and risks of AI in TME surgery.

机器人辅助腹腔镜下超低位直肠癌根治术(D3+TME)

直肠癌的全系膜切除手术(total mesorectal excision,TME)已经成为中低位直肠癌的标准术式,完全系膜的切除大大减少了直肠癌的局部复发率,从腹腔镜到机器人技术的应用引领着结直肠癌手术进入精细外科时代,活动的机械关节使得机器人手术在低位直肠癌中左右逢源,直肠周围神经解剖知识的更新、邓氏筋膜的显露和保留可以让功能保护做到更加细致,精准的手术操作符合肿瘤学根治原则和加速康复外科理念,尤其机器人手术在3D视野和精准电外科器械的加持下,更加契合TME理论中完整系膜切除的要求,减少了患者术后肿瘤复发的风险,值得在直肠恶性肿瘤手术中推广和应用.

Laparoscopic total mesorectal excision with natural orifice specimen extraction

AIM:To introduce transvaginal or transanal specimen extraction in laparoscopic total mesorectal excision surgery to avoid an abdominal incision. METHODS:Between January 2009 and December 2011,21 patients with rectal cancer underwent laparoscopic radical resection and the specimen was retrieved by two different ways:transvaginal or transanal rectal removal.Transvaginal specimen extraction approach was strictly limited to elderly post-menopausal women who need hysterectomy.Patients aged between 30 and 80 years,with a body mass index of less than 30 kg/m2, underwent elective surgery.The surgical technique and the outcomes related to the specimen extraction,such as duration of surgery,length of hospital stay,and the complications were retrospectively reviewed. RESULTS:Laparoscopic resection using a natural orifice removal approach was successful in all of the 21 patients.Median operating time was 185 min(range,122-260 min)and the estimated blood loss was 48 mL. The mean length of hospital stay was 7.5 d(range,2-11 d).One patient developed postoperative ileus and had an extended hospital stay.The patient complained of minimal pain.There were no postoperative complications or surgery-associated death.The mean size of the lesion was 2.8 cm(range,1.8-6.0 cm),and the mean number of lymph nodes harvested was 18.7(range, 8-27).At a mean follow-up of 20.6 mo(range,10-37 mo),there were no functional disorders associated with the transvaginal and transanal specimen extraction. CONCLUSION:Transvaginal or transanal extraction in L-TME is a safe and effective procedure.Natural orifice specimen extraction can avoid the abdominal wall incision and its potential complications.

Total mesorectal excision for mid and low rectal cancer: laparoscopic vs robotic surgery

AIM: To compare the short- and long-term outcomes of laparoscopic and robotic surgery for middle and low rectal cancer.METHODS: This is a retrospective study on a prospectively collected database containing 111 patients who underwent minimally invasive rectal resection with total mesorectal excision (TME) with curative intent between January 2008 and December 2014 (robot, n = 53; laparoscopy, n = 58). The patients all had a diagnosis of middle and low rectal adenocarcinoma with stage I-III disease. The median follow-up period was 37.4 mo. Perioperative results, morbidity a pathological data were evaluated and compared. The 3-year overall survival and disease-free survival rates were calculated and compared.RESULTS: Patients were comparable in terms of preoperative and demographic parameters. The median surgery time was 192 min for laparoscopic TME (L-TME) and 342 min for robotic TME (R-TME) (P < 0.001). There were no differences found in the rates of conversion to open surgery and morbidity. The patients who underwent laparoscopic surgery stayed in the hospital two days longer than the robotic group patients (8 d for L-TME and 6 d for R-TME, P < 0.001). The pathologic evaluation showed a higher number of harvested lymph nodes in the robotic group (18 for R-TME, 11 for L-TME, P < 0.001) and a shorter distal resection margin for laparoscopic patients (1.5 cm for L-TME, 2.5 cm for R-TME, P < 0.001). The three-year overall survival and disease-free survival rates were similar between groups.CONCLUSION: Both L-TME and R-TME achieved acceptable clinical and oncologic outcomes. The robotic technique showed some advantages in rectal surgery that should be validated by further studies.

Technical feasibility of laparoscopic extended surgerybeyond total mesorectal excision for primary or recurrentrectal cancer

Relatively little is known about the oncologic safety of laparoscopic surgery for advanced rectal cancer.Recently, large randomized clinical trials showed that laparoscopic surgery was not inferior to open surgery, as evidenced by survival and local control rates. However, patients with T4 tumors were excluded from these trials. Technological advances in the instrumentation and techniques used by laparoscopic surgery have increased the use of laparoscopic surgery for advanced rectal cancer. High-definition, illuminated, and magnified images obtained by laparoscopy may enable more precise laparoscopic surgery than open techniques, even during extended surgery for T4 or locally recurrent rectal cancer. To date, the quality of evidence regarding the usefulness of laparoscopy for extended surgery beyond total mesorectal excision has been low because most studies have been uncontrolled series, with small sample sizes, and long-term data are lacking. Nevertheless, laparoscopic extended surgery for rectal cancer, when performed by specialized laparoscopic colorectal surgeons, has been reported safe in selected patients, with significant advantages, including a clear visual field and less blood loss. This review summarizes current knowledge on laparoscopic extended surgery beyond total mesorectal excision for primary or locally recurrent rectal cancer.

Evolution of transanal total mesorectal excision for rectal cancer:From top to bottom

The gold standard for curative treatment of locally advanced rectal cancer involves radical resection with a total mesorectal excision(TME). TME is the most effective treatment strategy to reduce local recurrence and improve survival outcomes regardless of the surgical platform used. However, there are associated morbidities, functional consequences, and quality of life(QoL) issues associated with TME; these risks must be considered during the modern-day multidisciplinary treatment for rectal cancer. This has led to the development of new surgical techniques to improve patient, oncologic, and QoL outcomes. In this work, we review the evolution of TME to the transanal total mesorectal excision(TaTME) through more traditional minimally invasive platforms. The review the development, safety and feasibility, proposed benefits and risks of the procedure, implementation and education models, and future direction for research and implementation of the TaTME in colorectal surgery. While satisfactory short-term results have been reported, the procedure is in its infancy, and long term outcomes and definitive results from controlled trials are pending.As evidence for safety and feasibility accumulates,structured training programs to standardize teaching,training, and safe expansion will aid the safe spread of the TaTME.

Low-pressure pneumoperitoneum with abdominal wall lift in laparoscopic total mesorectal excision for rectal cancer:initial experience

AIM To evaluate the safety and feasibility of a new technology combining low-pressure pneumoperitoneum(LPP) and abdominal wall lift(AWL) in laparoscopic total mesorectal excision(TME) for rectal cancer.METHODS From November 2015 to July 2017,26 patients underwent laparoscopic TME for rectal cancer using LPP(6-8 mm Hg) with subcutaneous AWL in Qilu Hospital of Shandong University,Jinan,China.Clinical data regarding patients' demographics,intraoperative monitoring indices,operation-related indices andpathological outcomes were prospectively collected.RESULTS Laparoscopic TME was performed in 26 cases(14 anterior resection and 12 abdominoperineal resection) successfully,without conversion to open or laparoscopic surgery with standard-pressure pneumoperitoneum.Intraoperative monitoring showed stable heart rate,blood pressure and paw airway pressure.The mean operative time was 194.29 ± 41.27 min(range:125-270 min) and 200.41 ± 20.56 min(range:170-230 min) for anterior resection and abdominoperineal resection,respectively.The mean number of lymph nodes harvested was 16.71 ± 5.06(range:7-27).There was no positive circumferential or distal resection margin.No local recurrence was observed during a median follow-up period of 11.96 ± 5.55 mo(range:5-23 mo).CONCLUSION LPP combined with AWL is safe and feasible for laparoscopic TME.The technique can provide satisfactory exposure of the operative field and stable operative monitoring indices.

Transanal total mesorectal excision: Myths and reality

Transanal total mesorectal excision(TaTME) is a new and promising approach for the treatment of rectal cancer. Whilst the experience is still limited, there are growing evidences that this approach might overcome the limits of standard low anterior resection. TaTME might help to decrease the conversion rate especially in difficult patients, and to improve the pathological results, while preserving the urogenital function. Evaluation of data from large registries and randomized studies should help to draw firmer conclusions. Beyond these technical considerations, the next challenge seems to be clearly the safe introduction of this approach, motivating the development of dedicated courses.

Predicting prognosis of rectal cancer patients with total mesorectal excision using molecular markers

AIM:To explore the prognostic variables in rectal cancer patients undergoing curative total mesorectal excision and the effect of postoperative chemotherapy in advanced rectal cancer. METHODS:A total of 259 consecutive rectal cancer patients treated with curative total mesorectal excision between 1999 and 2004 were collected. p53,p21,PCNA,and CD44v6 were examined using immunohistochemistry (IHC). The correlation between clinicopathological or molecular variables and clinical outcomes,including local recurrence,metastasis,disease-free survival and overall survival,was analyzed. RESULTS:The median follow-up was 44 mo. Five-year survival rates and 5-year disease free survival rates were 75.43% and 70.32%,respectively. Multi-analysis revealed TNM staging,preoperative CEA,and CD44v6 level were independent risk factors predicting overall survival or disease free survival. The hazard ratio of peroperative CEA was 2.65 (95% CI 1.4-5) and 3.10 (95% CI 1.37-6.54) for disease free survival and overall survival,respectively. The hazard ratio of CD44v6 was 1.93 (95% CI 1.04-3.61) and 2.21 (95% CI 1.01-4.88) for disease free survival and overall survival,respectively. TNM staging was the only risk factor predicting local recurrence. Postoperative chemotherapy without radiotherapy did not improve patients' outcome. CONCLUSION:TNM staging,preoperative CEA and CD44v6 were independent prognostic factors for rectal cancer patients with total mesorectal excision. Postoperative chemotherapy may be only used together with radiotherapy for rectal cancer patients.

Routine defunctioning stoma after chemoradiation and total mesorectal excision:A single-surgeon experience

AIM:To investigate the 10-year results of treating low rectal cancer by a single surgeon in one institution.METHODS:From Oct 1998 to Feb 2009,we prospectively followed a total of 62 patients with cT2-4 low rectal cancer with lower tumor margins measuring at 3 to 6 cm above the anal verge.All patients received neoadjuvant chemoradiation(CRT) for 6 wk.Among them,85% of the patients received 225 mg/m2/d 5-fluorouracil using a portable infusion pump.The whole pelvis received a total dose of 45 Gy of irradiation in 25 fractions over 5 wk.The interval from CRT completion to surgical intervention was planned to be approximately 6-8 wk.Total mesorectal excision(TME) and routine defunctioning stoma construction were performed by one surgeon.The distal resection margin,circumferential resection margin,tumor regression grade(TRG) and other parameters were recorded.We used TRG to evaluate the tumor response after neoadjuvant CRT.We evaluated anal function outcomes using the Memorial Sloan-Kettering Cancer Center anal function scores after closure of the defunctioning stoma.RESULTS:The median distance from the lower margin of rectal cancer to the anal verge was 5 cm:6 cm in 9 patients,5 cm in 32 patients,4 cm in 10 patients,and 3 cm in 11 patients.Before receiving neoadjuvant CRT,45 patients(72.6%) had a cT3-4 tumor,and 21(33.9%) patients had a cN1-2 lymph node status.After CRT,30 patients(48.4%) had a greater than 50% clinical reduction in tumor size.The final pathology reports revealed that 33 patients(53.2%) had a ypT3-4 tumor and 12(19.4%) patients had ypN1-2 lymph node involvement.All patients completed the entire course of neoadjuvant CRT.Most patients developed only Grade 1-2 toxicities during CRT.Thirteen patients(21%) achieved a pathologic complete response.Few post-operative complications occurred.Nearly 90% of the defunctioning stomas were closed within 6 mo.The local recurrence rate was 3.2%.Pathologic lymph node involvement was the only prognostic factor predicting disease recurrence(36.5% vs 76.5%,P = 0.006).Nearly 90% of patients recovered sphincter function within 2 year after closure of the defunctioning stoma.CONCLUSION:Neoadjuvant CRT followed by TME,combined with routine defunctioning stoma construction and high-volume surgeon experience,can provide excellent surgical quality and good local disease control.

Systematic review of oncological outcomes following laparoscopic vs open total mesorectal excision

AIM: To systematically analyze the randomized trials comparing the oncological and clinical effectiveness of laparoscopic total mesorectal excision(LTME) vs open total mesorectal excision(OTME) in the management of rectal cancer.METHODS: Published randomized, controlled trials comparing the oncological and clinical effectiveness of LTME vs OTME in the management of rectal cancer were retrieved from the standard electronic medical databases. The data of included randomized, controlled trials was extracted and then analyzed according to the principles of meta-analysis using RevMan? statistical software. The combined outcome of the binary variables was expressed as odds ratio(OR) and the combined outcome of the continuous variables waspresented in the form of standardized mean difference(SMD). RESULTS: Data from eleven randomized, controlled trials on 2143 patients were retrieved from the electronic databases. There was a trend towards the higher risk of surgical site infection(OR = 0.66; 95%CI: 0.44-1.00; z = 1.94; P < 0.05), higher risk of incomplete total mesorectal resection(OR = 0.62; 95%CI: 0.43-0.91; z = 2.49; P < 0.01) and prolonged length of hospital stay(SMD,-1.59; 95%CI:-0.86--0.25; z = 4.22; P < 0.00001) following OTME. However, the oncological outcomes like number of harvested lymph nodes, tumour recurrence and risk of positive resection margins were statistically similar in both groups. In addition, the clinical outcomes such as operative complications, anastomotic leak and all-cause mortality were comparable between both approaches of mesorectal excision.CONCLUSION: LTME appears to have clinically and oncologically measurable advantages over OTME in patients with primary rectal cancer in both short term and long term follow ups.

Laparoscopy-assisted transanal total mesorectal excision for lower rectal cancer:A feasible and innovative technique

BACKGROUND Transanal total mesorectal excision(taTME)is a new technique with many potential technical advantages.Laparoscopy-assisted taTME is a combination of transabdominal taTME and transluminal endoscopic surgery taTME.Laparoscopy-assisted taTME is a combination of techniques such as minimally invasive surgery,intersphincter-assisted resection,natural orifice extraction,ta minimally invasive surgery,and ultralow-level preservation of the anus.AIM To verify the feasibility and safety of an innovative technique of taTME for treatment of cancer located in the lower rectum.METHODS From January 2016 to March 2018,we attempted to perform laparoscopy-assisted taTME surgery in 24 patients with lower rectal cancer.RESULTS The new technique of laparoscopy-assisted taTME was successfully performed in all 24 patients.Mean operating time was 310.0 min and mean intraoperative blood loss was 69.1 mL.The mean time to passing of first flatus was 3.1 d,and mean postoperative hospital stay was 9.2 d.Two patients were given postoperative analgesics due to anal pain.Twenty-three patients were able to walk in first 2 d,and five patients had postoperative complications.CONCLUSION Laparoscopy-assisted taTME is suitable for selected patients with lower rectal cancer,and this technique is worthy of further recommendation.

Sphincter-preserving R0 total mesorectal excision with resection of internal genitalia combined with pre-or postoperative chemoradiation for T4 rectal cancer in females

AIM: To evaluate the impact of chemoradiation admi- nistered pre- or postoperatively on prognosis in females following R0 extended resection with sphincter- preserving total mesorectal excision (TME) for locally advanced rectal cancer and to assess the association between chemoradiation and intra- and postoperative variables. METHODS: Twenty-one females were treated for locally advanced but preoperatively assessed as primarily resectable rectal cancer involving reproductive organs. Anterior resection with TME and excision of internal genitalia was combined with neo- or adjuvant chemoradiation. Two-year disease-free survival analysis was performed with the Kaplan-Meier method and log- rank test. The association between chemoradiation and other variables was evaluated with the Fisher’s exact test and Mann-Whitney test. RESULTS: Survival rate decreased in anaemic females (51.5% vs 57.4%), in patients older than 60 years (41.8% vs 66.7%) with poorly differentiated cancers (50.0% vs 55.6%) and tumors located ≤ 7 cm from the anal verge (42.9% vs 68.1%) but with the lack of importance. Patients with negative lymph nodes and women chemoradiated preoperatively had significantly favourable prognosis (85.7% vs 35.7%; P= 0.03 and 80.0% vs 27.3%; P = 0.01, respectively). Preoperative chemoradiation compared to adjuvant radiochemotherapy was not significantly associated with the duration of surgery, incidence of intraoperative bowel perforation and blood loss ≥ 1 L, rate of postoperative bladder and anorectal dysfunction, and minimal distal resection margin. It significantly influenced minimal radial margin (mean 4.2 mm vs 1.1 mm; P < 0.01). CONCLUSION: Despite involving internal genitalia, long-term disease-free survival and sphincter preservation may be achieved with combined-modality therapy for females with T4 locally advanced rectal carcinoma. Neoadjuvant chemoradiation does not compromise functional results and may significantly improve oncological outcomes probably due to enhanced radial clearance.

Simple instruments facilitating achievement of transanal total mesorectal excision in male patients

AIM To assess the efficacy of a modified approach with transanal total mesorectal excision(ta TME) using simple customized instruments in male patients with low rectal cancer.METHODS A total of 115 male patients with low rectal cancer from December 2006 to August 2015 were retrospectively studied. All patients had a bulky tumor(tumor diameter ≥ 40 mm). Forty-one patients(group A) underwent a classical approach of transabdominal total mesorectal excision(TME) and transanal intersphincteric resection(ISR), and the other 74 patients(group B) underwent a modified approach with transabdominal TME,transanal ISR, and ta TME. Some simple instruments including modified retractors and an anal dilator with a papilionaceous fixture were used to perform ta TME. The operative time, quality of mesorectal excision, circumferential resection margin, local recurrence, and postoperative survival were evaluated.RESULTS All 115 patients had successful sphincter preservation. The operative time in group B(240 min, range: 160-330 min) was significantly shorter than that in group A(280 min, range: 200-360 min; P = 0.000). Co m pa r e d w it h g r o up A, m o r e c o m p le t e d is t a l mesorectum and total mesorectum were achieved in group B(100% vs 75.6%, P = 0.000; 90.5% vs 70.7%, P = 0.008, respectively). After 46.1 ± 25.6 mo followup, group B had a lower local recurrence rate and higher disease-free survival rate compared with group A, but these differences were not statistically significant(5.4% vs 14.6%, P = 0.093; 79.5% vs 65.1%, P = 0.130). CONCLUSION Retrograde ta TME with simple customized instruments can achieve high-quality TME, and it might be an effective and economical alternative for male patients with bulky tumors.

Meta-analysis of transanal vs laparoscopic total mesorectal excision of low rectal cancer:Importance of appropriate patient selection

BACKGROUND Achieving a clear resection margins for low rectal cancer is technically challenging.Transanal approach to total mesorectal excision(TME)was introduced in order to address the challenges associated with the laparoscopic approach in treating low rectal cancers.However,previous meta-analyses have included mixed population with mid and low rectal tumours when comparing both approaches which has made the interpretation of the real differences between two approaches in treating low rectal cancer difficult.AIM To investigate the outcomes of transanal TME(TaTME)and laparoscopic TME(LaTME)in patients with low rectal cancer.METHODS A comprehensive systematic review of comparative studies was performed in line with Preferred Reporting Items for Systematic Reviews and Meta-Analyses standards.Intraoperative and postoperative complications,anastomotic leak,R0 resection,completeness of mesorectal excision,circumferential resection margin(CRM),distal resection margin(DRM),harvested lymph nodes,and operation time were the investigated outcome measures.RESULTS We included twelve comparative studies enrolling 969 patients comparing TaTME(n=969)and LaTME(n=476)in patients with low rectal tumours.TaTME was associated with significantly lower risk of postoperative complications(OR:0.74,P=0.04),anastomotic leak(OR:0.59,P=0.02),and conversion to an open procedure(OR:0.29,P=0.002)in comparison with LaTME.Moreover,the rate of R0 resection was significantly higher in the TaTME group(OR:1.96,P=0.03).Nevertheless,TaTME and LaTME were comparable in terms of rate of intraoperative complications(OR:1.87;P=0.23),completeness of mesoractal excision(OR:1.57,P=0.15),harvested lymph nodes(MD:-0.05,P=0.96),DRM(MD:-0.94;P=0.17),CRM(MD:1.08,P=0.17),positive CRM(OR:0.64,P=0.11)and procedure time(MD:-6.99 min,P=0.45).CONCLUSION Our findings indicated that for low rectal tumours,TaTME is associated with better clinical and short term oncological outcomes compared to LaTME.More randomised controlled trials are required to confirm these findings and to evaluate long term oncological and functional outcomes.

Robotic transanal total mesorectal excision:Is the future now?

Total mesorectal excision(TME)is the standard surgical treatment for the curative radical resection of rectal cancers.Minimally invasive TME has been gaining ground favored by the continuous technological advancements.New procedures,such as transanal TME(TaTME),have been introduced to overcome some technical limitations,especially in low rectal tumors,obese patients,and/or narrow pelvis.The earliest TaTME reports showed promising results when compared with the conventional laparoscopic TME.However,recent publications raised concerns regarding the high rates of anastomotic leaks or local recurrences observed in national series.Robotic TaTME(R-TaTME)has been proposed as a novel technique incorporating the potential benefits of a perineal dissection together with precise control of the distal margins,and also offers all those advantages provided by the robotic technology in terms of improved precision and dexterity.Encouraging short-term results have been reported for R-TaTME,but further studies are needed to assess the real role of the new technique in the long-term oncological or functional outcomes.The present review aims to provide a general overview of R-TaTME by analyzing the body of the available literature,with a special focus on the potential benefits,harms,and future perspectives for this novel approach.

Feasibility and limitations of combined treatment for lateral pelvic lymph node metastases in rectal cancer

Colorectal cancer ranks among the most commonly diagnosed cancers globally,and is associated with a high rate of pelvic recurrence after surgery.In efforts to mitigate recurrence,pelvic lymph node dissection(PLND)is commonly advocated as an adjunct to radical surgery.Neoadjuvant chemoradiotherapy(NACRT)is a therapeutic approach employed in managing locally advanced rectal cancer,and has been found to increase the survival rates.Chua et al have proposed a combination of NACRT with selective PLND for addressing lateral pelvic lymph node metastases in rectal cancer patients,with the aim of reducing recurrence and improving survival outcomes.Nevertheless,certain studies have indicated that the addition of PLND to NACRT and total mesorectal excision did not yield a significant reduction in local recurrence rates or improvement in survival.Consequently,meticulous patient selection and perioperative chemotherapy may prove indispensable in ensuring the efficacy of PLND.

Real-time in vivo distal margin selection using confocal laser endomicroscopy in transanal total mesorectal excision for rectal cancer

BACKGROUND Transanal total mesorectal excision(TaTME)allows patients with ultralow rectal cancer to be treated with sphincter-saving surgery.However,accurate delineation of the distal resection margin(DRM),which is essential to achieve R0 resection for low rectal cancer in TaTME,is technically demanding.AIM To assess the feasibility of optical biopsy using probe-based confocal laser endomicroscopy(pCLE)to select the DRM during TaTME for low rectal cancer.METHODS A total of 43 consecutive patients who were diagnosed with low rectal cancer and scheduled for TaTME were prospectively enrolled from January 2019 to January 2021.pCLE was used to determine the distal edge of the tumor as well as the DRM during surgery.The final pathological report was used as the gold standard.The diagnostic accuracy of pCLE examination was calculated.RESULTS A total of 86 pCLE videos of 43 patients were included in the analyses.The sensitivity,specificity and accuracy of real-time pCLE examination were 90.00%[95%confidence interval(CI):76.34%-97.21%],86.96%(95%CI:73.74%-95.06%)and 88.37%(95%CI:79.65%-94.28%),respectively.The accuracy of blinded pCLE reinterpretation was 86.05%(95%CI:76.89%-92.58%).Furthermore,our results show satisfactory interobserver agreement(κ=0.767,standard error=0.069)for the detection of cancer tissue by pCLE.There were no positive DRMs(≤1 mm)in this study.The median DRM was 7 mm[interquartile range(IQR)=5-10 mm].The median Wexner score was 5(IQR=3-6)at 6 mo after stoma closure.CONCLUSION Real-time in vivo pCLE examination is feasible and safe for selecting the DRM during TaTME for low rectal cancer(clinical trial registration number:NCT04016948).