Artificial intelligence-assisted decision making: Prediction of optimal level of distal mesorectal margin during transanal total mesorectal excision (taTME) using deep neural network modeling.

BACKGROUND: With steep posterior anorectal angulation, transanal total mesorectal excision (taTME) may have a risk of dissection in the wrong plane or starting higher up, resulting in leaving distal mesorectum behind. Although the distal mesorectal margin can be assessed by preoperative MRI, it needs skilled radiologist and high-definition image for accurate evaluation. This study developed a deep neural network (DNN) to predict the optimal level of distal mesorectal margin. METHODS: A total of 182 pelvic MRI images extracted from the cancer image archive (TCIA) database were included. A DNN was developed using gender, the degree of anterior and posterior anorectal angles as input variables while the difference between anterior and posterior mesorectal distances from anal verge was selected as a target. The predictability power was assessed by regression values (R) which is the correlation between the predicted outputs and actual targets. RESULTS: The anterior angle was an obtuse angle while the posterior angle varied from acute to obtuse with mean angle difference 35.5°±14.6. The mean difference between the anterior and posterior mesorectal end distances was 18.6±6.6mm. The developed DNN had a very close correlation with the target during training, validation, and testing (R=0.99, 0.81, and 0.89, P<0.001). The predicted level of distal mesorectal margin was closely correlated with the actual optimal level (R=0.91, P<0.001). CONCLUSIONS: Artificial intelligence can assist in either making or confirming the preoperative decisions. Furthermore, the developed model can alert the surgeons for this potential risk and the necessity of re-positioning the proctectomy incision.

Major colorectal surgery with Hugo™ RAS: initial experience of a German center and a review of the literature.

The recently introduced Hugo RAS robotic platform has mostly been used for well standardized urologic and gynaecologic procedures. Experience with this new system in general surgery and especially in major colorectal surgery is very limited. This is a retrospective series of the first 25 consecutive non-selected colorectal surgeries performed at a single German center. The lessons learned from our initial experience are presented along with a systematic review of the currently available literature on this topic. Ten sigmoid and seven rectal resections, four right and one left hemicolectomies, two Hartmann's reversals and an abdominoperineal resection were performed in 14 women and 11 men at the median age of 66 years for 12 benign findings and 13 malignancies. All procedures were performed using four robotic ports and a single 12 mm assistant port. Median docking, console and total operative times were 12, 170 and 270 min. Median blood loss was < 100 ml, and median stay was 8 days. The literature review identified five case series with a total of 23 colorectal procedures: 9 right and 1 left hemicolectomies, 5 ileocaecal, and 4 rectal and 4 sigmoid resections. Results corresponded to ours despite variations in setup used by different authors. A wide spectrum of major colorectal surgery can be safely and effectively performed with the Hugo RAS, even in a cohort of non-selected patients. Ongoing software and hardware upgrade, introduction of robotic energy devices and increasing surgical experience are expected to facilitate procedures and reduce duration of surgery.

Efficacy of lateral lymph node dissection for local control of rectal cancer: A multicenter study.

Background: This study aimed to evaluate the efficacy of lateral lymph node dissection (LLND) for rectal cancer by comparing the local control in patients with and without pathological lateral lymph node metastasis (LLNM). Methods: We included 189 patients with rectal cancer who underwent total mesorectal excision and LLND at 13 institutions between 2017 and 2019. Patients with and without pathological LLNM were defined as the pLLNM (+) and (-) groups, respectively. Propensity score-matching helped to balance the basic characteristics of both groups. The incidences of local recurrence (LR) and lateral lymph node recurrence (LLNR) were compared between the groups. Results: In the entire cohort, 39 of the 189 patients had pathological LLNM. The 3-year LR and LLNR rates were 18.3% and 4.0% (p = 0.01) and 7.7% and 3.3% (p = 0.22) in the pLLNM (+) and (-) groups, respectively. After propensity score matching, the data from 62 patients were analyzed. No significant differences in LR or LLNR were observed between both groups. The 3-year LR and LLNR rates were 16.4% and 9.8% (p = 0.46) and 9.7% and 9.8% (p = 0.99) in the pLLNM (+) and (-) groups, respectively. Conclusion: LLND would lead to comparable local control in the pLLNM (+) and (-) groups if the clinicopathological characteristics except for LLNM are similar.

Changes to circulating tumor cells in the central vein during laparoscopic versus transanal endoscopic surgeries for rectal cancer: can surgical approach make a difference?

Background: The oncological safety of transanal total mesorectal excision (taTME) remains uncertain, and its special surgical approach may contribute to tumor cell dissemination. Thus, we conducted a study to investigate the impact of surgical approach on circulating tumor cell (CTC) counts and phenotypes in rectal cancer. Methods: This is a prospective randomized controlled study (ClinicalTrials: NCT05109130). The patients were randomized to either the taTME (n = 49) or laparoscopic TME (laTME) (n = 48) groups. Blood samples were collected from the central vein to measure CTC counts and phenotypes at three time points: preoperative (t1), immediately post-tumor removal (t2), and one week post-surgery (t3). The effect of surgical procedure on CTCs at each time point was analyzed, with the primary endpoint being the change in CTC counts from t1 to t3 for each surgical approach. This study adheres to Consolidated Standards of Reporting Trials Guidelines. Results: The baseline clinicopathologic characteristics of the laTME and taTME groups were balanced. The change in CTC count from t1 to t3 was 1.81 ± 5.66 in the laTME group and 2.18 ± 5.53 in the taTME group. The taTME surgery was non-inferior to laTME in terms of changing CTC counts (mean difference [MD]: -0.371; 95% confidence interval [CI]: -2.626 to 1.883, upper-sided 95% CI of 1.883 < 2, non-inferiority boundary value). Compared with that at t1, the CTC count at t2 did not change significantly. However, higher CTC counts were detected at t3 than at t2 in the taTME (P = 0.032) and laTME (P = 0.003) groups. From t1 to t3, CTC counts significantly increased in both the taTME (P = 0.008) and laTME (P = 0.031) groups. There were no significant differences in CTC phenotype changes between the two groups from t1 to t3. Conclusions: Compared with laTME, taTME did not affect CTC counts and phenotypes. Our findings indicate that taTME is not inferior to laTME in terms of CTC changes from an oncological perspective.

Long-Term Outcomes of Robotic Versus Laparoscopic Total Mesorectal Excisions: A Propensity-Score Matched Cohort study of 5-year survival outcomes.

Objective: To compare long-term outcomes between laparoscopic and robotic total mesorectal excisions (TMEs) for rectal cancer in a tertiary center. Background: Laparoscopic rectal cancer surgery has comparable long-term outcomes to the open approach, with several advantages in short-term outcomes. However, it has significant technical limitations, which the robotic approach aims to overcome. Methods: We included patients undergoing laparoscopic and robotic TME surgery between 2013 and 2021. The groups were compared after propensity-score matching. The primary outcome was 5-year overall survival (OS). Secondary outcomes were local recurrence (LR), distant recurrence (DR), disease-free survival (DFS), and short-term surgical and patient-related outcomes. Results: A total of 594 patients were included, and after propensity-score matching 215 patients remained in each group. There was a significant difference in 5-year OS (72.4% for laparoscopy vs 81.7% for robotic, P = 0.029), but no difference in 5-year LR (4.7% vs 5.2%, P = 0.850), DR (16.9% vs 13.5%, P = 0.390), or DFS (63.9% vs 74.4%, P = 0.086). The robotic group had significantly less conversion (3.7% vs 0.5%, P = 0.046), shorter length of stay [7.0 (6.0-13.0) vs 6.0 (4.0-8.0), P < 0.001), and less postoperative complications (63.5% vs 50.7%, P = 0.010). Conclusions: This study shows a correlation between higher 5-year OS and comparable long-term oncological outcomes for robotic TME surgery compared to the laparoscopic approach. Furthermore, lower conversion rates, a shorter length of stay, and a less minor postoperative complications were observed. Robotic rectal cancer surgery is a safe and favorable alternative to the traditional approaches.

Functional outcomes and quality of life following open versus laparoscopic versus robot-assisted versus transanal total mesorectal excision in rectal cancer patients: a systematic review and meta-analysis.

BACKGROUND: The standard surgical treatment for rectal cancer is total mesorectal excision (TME), which may negatively affect patients' functional outcomes and quality of life (QoL). However, it is unclear how different TME techniques may impact patients' functional outcomes and QoL. This systematic review and meta-analysis evaluated functional outcomes of urinary, sexual, and fecal functioning as well as QoL after open, laparoscopic (L-TME), robot-assisted (R-TME), and transanal total mesorectal excision (TaTME). METHODS: A systematic review and meta-analysis, based on the preferred reporting items for systematic reviews and meta-analysis statement, were conducted (PROSPERO: CRD42021240851). A literature review was performed (sources: PubMed, Medline, Embase, Scopus, Web of Science, and Cochrane Library databases; end-of-search date: September 1, 2023), and a quality assessment was performed using the Methodological index for non-randomized studies. A random-effects model was used to pool the data for the meta-analyses. RESULTS: Nineteen studies were included, reporting on 2495 patients (88 open, 1171 L-TME, 995 R-TME, and 241 TaTME). Quantitative analyses comparing L-TME vs. R-TME showed no significant differences regarding urinary and sexual functioning, except for urinary function at three months post-surgery, which favoured R-TME (SMD [CI] -0 .15 [- 0.24 to - 0.06], p = 0.02; n = 401). Qualitative analyses identified most studies did not find significant differences in urinary, sexual, and fecal functioning and QoL between different techniques. CONCLUSIONS: This systematic review and meta-analysis highlight a significant gap in the literature concerning the evaluation of functional outcomes and QoL after TME for rectal cancer treatment. This study emphasizes the need for high-quality, randomized-controlled, and prospective cohort studies evaluating these outcomes. Based on the limited available evidence, this systematic review and meta-analysis suggests no significant differences in patients' urinary, sexual, and fecal functioning and their QoL across various TME techniques.

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.

Local Recurrence of Rectal Cancer After Transanal Total Mesorectal Excision and Risk Factors: A Nationwide Multicenter Cohort Study in Japan.

Objective: To investigate the oncological outcomes after transanal total mesorectal excision (TaTME) for rectal cancer and risk factors for local recurrence (LR). Background: A high LR rate with a multifocal pattern early after TaTME has been reported in Norway and the Netherlands, causing controversy over the oncological safety of this technique. Methods: Twenty-six member institutions of the Japan Society of Laparoscopic Colorectal Surgery participated in this retrospective cohort study. A total of 706 patients with primary rectal cancer who underwent TaTME between January 2012 and December 2019 were included for analysis. The primary endpoint was the cumulative 3-year LR rate. Results: A total of 253 patients had clinical stage III disease (35.8%) and 91 (12.9%) had stage IV. Intersphincteric resection was performed in 318 patients (45.0%) and abdominoperineal resection in 193 (27.3%). There was 1 urethral injury (0.1%). A positive resection margin (R1) was seen in 42 patients (5.9%). Median follow-up was 3.42 years, and the 2- and 3-year cumulative LR rates were 4.95% (95% confidence interval: 3.50-6.75) and 6.82% (95% confidence interval: 5.08-8.89), respectively. A multifocal pattern was observed in 14 (25%) of 56 patients with LR. Tumor height from the anal verge, pathological T4 disease, pathological stage III/IV, positive perineural invasion, and R1 resection were significant risk factors for LR in multivariable analysis. Conclusions: In this selected cohort in which intersphincteric resection or abdominoperineal resection was performed in more than half of cases, oncological outcomes were acceptable during a median follow-up of more than 3 years.

Association of Surgical Approaches and Outcomes in Total Mesorectal Excision and Margin Status for Rectal Cancer.

INTRODUCTION: Despite being a key metric with a significant correlation with the outcomes of patients with rectal cancer, the optimal surgical approach for total mesorectal excision (TME) has not yet been identified. The aim of this study was to assess the association of the surgical approach on the quality of TME and surgical margins and to characterize the surgical and long-term oncologic outcomes in patients undergoing robotic, laparoscopic, and open TME for rectal cancer. METHODS: Patients with primary, nonmetastatic rectal adenocarcinoma who underwent either lower anterior resection or abdominoperineal resection via robotic (Rob), laparoscopic (Lap), or open approaches were selected from the US Rectal Cancer Consortium database (2007-2017). Quasi-Poisson regression analysis with backward selection was used to investigate the relationship between the surgical approach and outcomes of interest. RESULTS: Among the 664 patients included in the study, the distribution of surgical approaches was as follows: 351 (52.9%) underwent TME via the open approach, 159 (23.9%) via the robotic approach, and 154 (23.2%) via the laparoscopic approach. There were no significant differences in baseline demographics among the three cohorts. The laparoscopic cohort had fewer patients with low rectal cancer (<6 cm from the anal verge) than the robotic and open cohorts (Lap 28.6% versus Rob 59.1% versus Open 45.6%, P = 0.015). Patients who underwent Rob and Lap TME had lower intraoperative blood loss compared with the Open approach (Rob 200 mL [Q1, Q3: 100.0, 300.0] versus Lap 150 mL [Q1, Q3: 75.0, 250.0] versus Open 300 mL [Q1, Q3: 150.0, 600.0], P < 0.001). There was no difference in the operative time (Rob 243 min [Q1, Q3: 203.8, 300.2] versus Lap 241 min [Q1, Q3: 186, 336] versus Open 226 min [Q1, Q3: 178, 315.8], P = 0.309) between the three approaches. Postoperative length of stay was shorter with robotic and laparoscopic approach compared to open approach (Rob 5.0 d [Q1, Q3: 4, 8.2] versus Lap 5 d [Q1, Q3: 4, 8] versus Open 7.0 d [Q1, Q3: 5, 9], P < 0.001). There was no statistically significant difference in the quality of TME between the robotic, laparoscopic, and open approaches (79.2%, 64.9%, and 64.7%, respectively; P = 0.46). The margin positivity rate, a composite of circumferential margin and distal margin, was higher with the robotic and open approaches than with the laparoscopic approach (Rob 8.2% versus Open 6.6% versus Lap 1.9%, P = 0.17), Rob versus Lap (odds ratio 0.21; 95% confidence interval 0.05, 0.83) and Rob versus Open (odds ratio 0.5; 95% confidence interval 0.22, 1.12). There was no difference in long-term survival, including overall survival and recurrence-free survival, between patients who underwent robotic, laparoscopic, or open TME (Figure 1). CONCLUSIONS: In patients undergoing surgery with curative intent for rectal cancer, we did not observe a difference in the quality of TME between the robotic, laparoscopic, or open approaches. Robotic and open TME compared to laparoscopic TME were associated with higher margin positivity rates in our study. This was likely due to the higher percentage of low rectal cancers in the robotic and open cohorts. We also reported no significant differences in overall survival and recurrence-free survival between the aforementioned surgical techniques.

Comparison of local excision and total mesorectal excision for rectal cancer: Systematic review and meta-analysis of randomised controlled trial.

To report the first and largest systematic review and meta-analysis of radomised controlled trials (RCTs) to compare the efficacy and safety of transanal endoscopic microsurgery (TEM) and total mesorectal excision (TME) for rectal cancer for perioperative and oncological outcomes. Methods: We conducted a systematic literature retrieval via PubMed, Embase, Web of Science, and Cochrane until December 2022 for RCTs which evaluated the efficacy and/or safety between TEM and TME for rectal cancer. Outcomes included operative time, blood loss, transfusion rates, hospital stay, complication rates, recurrence rates, and mortality. Results: A total of 5 RCTs involving 545 patients (272 TEM versus 273 TME) were included for the meta-analysis. There were no significant differences between the two groups for age, gender, and distance from lower border of tumor to anal verge. Meta-analysis found that the TEM group was significantly favorable than the TME group for blood loss (WMD: 172.01; 95 % CI: 212.78, -131.24; P < 0.00001), hospital stay (WMD: 2.58; 95 % CI: 3.01, -2.16; P < 0.00001), operative time (WMD: 81.86; 95 % CI: 87.51, -76.21; P < 0.00001) and transfusion rates (RR: 0.05; 95 % CI: 0.01, 0.38; P = 0.004). The complication rates (RR: 0.60; 95 % CI: 0.32, 1.11; P = 0.10), recurrence rates (RR: 1.10; 95 % CI: 0.66, 1.83; P = 0.72), and mortality (RR: 1.23; 95 % CI: 0.67, 2.26; P = 0.51) were similar in the two groups. Conclusions: TEM was an effective and safe approach with advantages in perioperative outcomes compared with TME approach. Caution should be exercised in interpreting the differences in surgical complications between TEM and TME group due to significant heterogeneity and instability.

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 robotic-assisted 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 robot-assisted 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 outcomes 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.

Robotic transanal minimally invasive surgery (r-TAMIS): perioperative and short-term outcomes for local excision of rectal cancers.

BACKGROUND: Transanal minimally invasive surgery (TAMIS) is an advanced technique for excision of early rectal cancers. Robotic TAMIS (r-TAMIS) has been introduced as technical improvement and potential alternative to total mesorectal excision (TME) in early rectal cancers and in frail patients. This study reports the perioperative and short-term oncological outcomes of r-TAMIS for local excision of early-stage rectal cancers. METHODS: Retrospective analysis of a prospectively collected r-TAMIS database (July 2021-July 2023). Demographics, clinicopathological features, short-term outcomes, recurrences, and survival were investigated. RESULTS: Twenty patients were included. Median age and body mass index were 69.5 (62.0-77.7) years and 31.0 (21.0-36.5) kg/m2. Male sex was prevalent (n = 12, 60.0%). ASA III accounted for 66.7%. Median distance from anal verge was 7.5 (5.0-11.7) cm. Median operation time was 90.0 (60.0-112.5) minutes. Blood loss was minimal. There were no conversions. Median postoperative stay was 2.0 (1.0-3.0) days. Minor and major complication rates were 25.0% and 0%, respectively. Seventeen (85.0%) patients had an adenocarcinoma whilst three patients had an adenoma. R0 rate was 90.0%. Most tumours were pT1 (55.0%), followed by pT2 (25.0%). One patient (5.0%) had a pT3 tumour. Specimen and tumour maximal median diameter were 51.0 (41.0-62.0) mm and 21.5 (17.2-42.0) mm, respectively. Median specimen area was 193.1 (134.3-323.3) cm2. Median follow-up was 15.5 (10.0-24.0) months. One patient developed local recurrence (5.0%). CONCLUSIONS: r-TAMIS, with strict postoperative surveillance, is a safe and feasible approach for local excision of early rectal cancer and may have a role in surgically unfit and elderly patients who refuse or cannot undergo TME surgery. Future prospective multicentre large-scale studies are needed to report the long-term oncological outcomes.

Long-term restoration of bowel continuity after rectal cancer resection and the influence of surgical technique: A nationwide cross-sectional study.

AIM: Literature on nationwide long-term permanent stoma rates after rectal cancer resection in the minimally invasive era is scarce. The aim of this population-based study was to provide more insight into the permanent stoma rate with interhospital variability (IHV) depending on surgical technique, with pelvic sepsis, unplanned reinterventions and readmissions as secondary outcomes. METHOD: Patients who underwent open or minimally invasive resection of rectal cancer (lower border below the sigmoid take-off) in 67 Dutch centres in 2016 were included in this cross-sectional cohort study. RESULTS: Among 2530 patients, 1470 underwent a restorative resection (58%), 356 a Hartmann's procedure (14%, IHV 0%-42%) and 704 an abdominoperineal resection (28%, IHV 3%-60%). Median follow-up was 51 months. The overall permanent stoma rate at last follow-up was 50% (IHV 13%-79%) and the unintentional permanent stoma rate, permanent stoma after a restorative procedure or an unplanned Hartmann's procedure, was 11% (IHV 0%-29%). A total of 2165 patients (86%) underwent a minimally invasive resection: 1760 conventional (81%), 170 transanal (8%) and 235 robot-assisted (11%). An anastomosis was created in 59%, 80% and 66%, with corresponding unintentional permanent stoma rates of 12%, 24% and 14% (p = 0.001), respectively. When corrected for age, American Society of Anesthesiologists classification, cTNM, distance to the anorectal junction and neoadjuvant (chemo)radiotherapy, the minimally invasive technique was not associated with an unintended permanent stoma (p = 0.071) after a restorative procedure. CONCLUSION: A remarkable IHV in the permanent stoma rate after rectal cancer resection was found. No beneficial influence of transanal or robot-assisted laparoscopy on the unintentional permanent stoma rate was found, although this might be caused by the surgical learning curve. A reduction in IHV and improving preoperative counselling for decision-making for restorative procedures are required.

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.

Management of lateral pelvic lymph nodes in rectal cancer: Is it time to reach an Agreement?

In this editorial, we proceed to comment on the article by Chua et al, addressing the management of metastatic lateral pelvic lymph nodes (mLLN) in stage II/III rectal cancer patients below the peritoneal reflection. The treatment of this nodal area sparks significant controversy due to the strategic differences followed by Eastern and Western physicians, albeit with a higher degree of convergence in recent years. The dissection of lateral pelvic lymph nodes without neoadjuvant therapy is a standard practice in Eastern countries. In contrast, in the West, preference leans towards opting for neoadjuvant therapy with chemoradiotherapy or radiotherapy, that would cover the treatment of this area without the need to add the dissection of these nodes to the total mesorectal excision. In the presence of high-risk nodal characteristics for mLLN related to radiological imaging and lack of response to neoadjuvant therapy, the risk of lateral local recurrence increases, suggesting the appropriate selection of strategies to reduce the risk of recurrence in each patient profile. Despite the heterogeneous and retrospective nature of studies addressing this area, an international consensus is necessary to approach this clinical scenario uniformly.

A dynamic nomogram for predicting pathologic complete response to neoadjuvant chemotherapy in locally advanced rectal cancer.

AIM: To explore the clinical factors associated with pathologic complete response (pCR) for locally advanced rectal cancer (LARC) patients treated with neoadjuvant chemoradiotherapy (nCRT) and develop a web-based dynamic nomogram. METHODS: Retrospective analysis of patients with examination confirmed LARC from 2011 to 2022. Patients from the Union Hospital of Fujian Medical University were included as the training cohort (n = 1579) and Zhangzhou Hospital of Fujian Medical University as the external validation cohort (n = 246). RESULTS: In the training cohort, after nCRT, 350 (22.2%) patients achieved pCR. More stomas were avoided in pCR patients (73.9% vs. 69.7%, p = 0.043). After a median follow-up time of 47.7 months (IQR 2-145) shown OS (5-year: 93.7% vs. 81.0%, HR = 0.310, 95%CI: 0.189-0.510, p < 0.001) and DFS (5-year: 91.2% vs. 75.0%, HR = 0.204, 95%CI: 0.216-0.484, p < 0.001) were significantly better among patients with pCR than non-pCR. Multivariable Logistic analysis shown pCR was significantly associated with Pre-CRT CEA (HR = 0.944, 95%CI: 0.921-0.968; p < 0.001), histopathology (HR = 4.608, 95%CI: 2.625-8.089; p < 0.001), Pre-CRT T stage (HR = 0.793, 95%CI: 0.634-0.993; p = 0.043), Pre-CRT N stage (HR = 0.727, 95%CI: 0.606-0.873; p = 0.001), Pre-CRT MRI EMVI (HR = 0.352, 95%CI: 0.262-0.473; p < 0.001), total neoadjuvant therapy (HR = 2.264, 95%CI: 1.280-4.004; p = 0.005). Meanwhile, the online version of the nomogram established in this study was publicized on an open-access website (URL: https://pcrpredict.shinyapps.io/LARC2/). The model predicted accuracy with a C-index of 0.73 (95% CI: 0.70-0.75), with an average C-index of 0.73 for the internal cross validation and 0.78 (95% CI: 0.72-0.83) for the external validation cohort, showing excellent model accuracy. Delong test results showed the model has an important gain value for clinical characteristics to predict pCR in rectal cancer. CONCLUSIONS: Patients with pCR had a better prognosis, including OS and DFS, and were independently associated with Pre-CRT CEA, histopathology, Pre-CRT T/N stage, Pre-CRT MRI EMVI, and TNT. A web-based dynamic nomogram was successfully established for clinical use at any time.

Robotic low anterior resection with complete splenic flexure mobilization and defunctioning left-sided loop colostomy: a case series.

A defunctioning stoma is used to alleviate the consequences of anastomotic leakage after low anterior resection for rectal cancer. A loop ileostomy is often preferred but may lead to dehydration and kidney injury. Here, we present a case series for an alternative: the left-sided loop colostomy. A convenience sample of four patients underwent robotic low anterior resection for rectal cancer. A complete splenic flexure mobilization and a total mesorectal excision were performed. To defunction the anastomosis, the redundant left colon was brought up to a stoma site in the left iliac fossa and matured as a loop colostomy. Two patients experienced minor stoma leaks and one also had a small prolapse, while all patients had their colostomies reversed on average 7 months after surgery without complications. There were no dehydration episodes and creatinine levels remained within baseline levels at end of follow-up (on average 18 months).

Analysis of Bacterial Culture of Fluid in the Surgical Area in Transanal Total Mesorectal Excision and Laparoscopic Total Mesorectal Excision.

Purpose: To investigate the clinical value of the bacterial culture of fluid in the surgical area in laparoscopic transanal total mesorectal excision (Lap-taTME) and laparoscopic total mesorectal excision (Lap-TME). Methods: Clinical data of 106 patients with rectal cancer who had undergone surgery were retrospectively collected, including 56 patients in the Lap-taTME group and 50 patients in the Lap-TME group. In the Lap-taTME group, the initial pelvic fluid, the rectal cavity fluid after purse-string suture, and the pelvic cavity fluid after anastomosis were collected and recorded as culture No. 1, No. 2, and No. 3, respectively. In the Lap-TME group, culture No. 1 and No. 3 were collected as done in the Lap-taTME group. The culture results and postoperative complications were statistically analyzed. Results: The positive rate of culture No. 1 was zero in both groups, and there were 6 cases (10.7%) with positive culture No. 2 in the Lap-taTME group. However, the number of patients with positive culture No. 3 (7, 12.5%) and cumulative positive culture cases (11, 19.6%) in the Lap-taTME group were significantly higher than those in the Lap-TME group (0) (all P < .05). Pelvic infection occurred in 4 (7.1%) of the 11 cases (19.6%) with positive culture in the Lap-taTME group, accounting for 36.4% (4/11). There were no significant intergroup differences in anastomotic leakage and pelvic infection (all P > .05). Conclusion: Positive bacterial culture of fluid during Lap-taTME indicates an increased risk of pelvic infection after operation. Lap-taTME is more prone to intraoperative contamination than Lap-TME but does not significantly increase the risk of postoperative pelvic infection.

Surgical management of rectal cancer with synchronous treatment of prostate cancer.

PURPOSE: To assess the safety and efficacy of synchronous treatments for rectal (RC) and prostate (PC) cancers. METHODS: Single-center retrospective study (2007-2021) of patients treated with neoadjuvant radiotherapy (RT) and total mesorectal excision (TME) for RC with synchronous PC treatment. The endpoints were 30-day postoperative severe complications, R0 resection rates, 3-year disease-free survival (DFS) and 3-year overall survival (OS). RESULTS: Among the 16 patients, 15 (93.7%) received neoadjuvant pelvic RT (40-50.4 Gray) followed by either transperineal high dose rate prostate brachytherapy (62.5%), prostate external RT boost (25.0%), or androgen deprivation therapy (ADT) alone (6.3%). One (6.3%) patient received neoadjuvant rectal brachytherapy and ADT. Pelvic RT was combined with chemotherapy in 87.5% of cases. TME was performed in all patients with low anterior resection (87.5%) or abdominoperineal resection (12.5%), primarily using minimally invasive surgery (87.5%). The R0 resection rate was 93.8%. Six (37.5%) patients experienced 30-day Clavien-Dindo grade IIIb complications, including one (7.1%) anastomotic leak. After a median follow-up of 39.0 months, 63.6% of diverting ileostomies were reversed. Three-year DFS from RC was 71.4% (CI 40.2-88.3) and 3-year OS was 84.4% (CI 95% 50.4-95.9). No PC recurrence or death occurred. CONCLUSIONS: Synchronous management of RC and PC with pelvic RT followed by curative prostate RT doses and TME showed acceptable morbidity and oncologic results. Prostate brachytherapy, the most commonly used treatment modality, allowed avoidance of prostatectomy and additional external RT to the rectum. PC should not limit the curative intent of RC, as all recurrences were from rectal origin.

Conversion rate to open surgery during transanal total mesorectal excision (TaTME) for rectal cancer: a single-center experience.

Minimally invasive techniques for rectal cancer have demonstrated considerable advantages in terms of faster recovery and less post-operative complications. However, due to the complex anatomy and a limited surgical field, conversion to open surgery is still sometimes required, with a negative impact on the short-and long-term outcomes. The purpose of this study was to analyse the conversion rate to open abdominal surgery during laparoscopic transanal total mesorectal excision (TaTME) procedures performed at a high-volume Italian referral center. All consecutive TaTME performed for mid-to-low rectal cancer between 2015 and 2023 were reviewed, independently if treated with a primary anastomosis (with/without a diverting ostomy) or an end stoma. All procedures were performed using a standardized approach by the same surgical team. Patients with benign diagnosis that underwent different-from rectal resection procedures and cases pre-operatively scheduled for open surgery were excluded. The primary outcome of interest was the rate of conversion, defined as an un-planned intraoperative switch to open surgery using a midline laparotomy. Secondary aims included the comparison of patients who had a longer vs shorter operative time. Out of 220 patients, 210 were selected. In 187 cases, a primary anastomosis was performed, while 23 patients received a terminal colostomy (1 in the converted group; 22 in the full MIS- TaTME group, 10.6%). A surgical approach modification occurred in two cases, with a conversion rate of 0.95%. Median operative time was 281 min. Reasons for conversions included intra-operative difficulties impairing the mini-invasive procedure without intra-operative complications in one case, and difficulties in the laparoscopic control of an intraoperative bleeding due to a splenic lesion in another patient. Male sex and a higher BMI were found to be statistically significantly associated to longer operative time (respectively: p = 0.001 and p = 0.0025). In a high-volume center, a standardized TaTME is associated to a low conversion rate to open abdominal surgery.