Endoscopic submucosal dissection versus endoscopic mucosal resection for the treatment of rectal lesions involving the dentate line.

BACKGROUND: The ideal treatment of epithelial neoplastic rectal lesions involving the dentate line is a controversial issue. Piecemeal endoscopic mucosal resection (EMR) is the most commonly used resection technique, but it is associated with high recurrence rates. Endoscopic submucosal dissection (ESD) has been shown to be safe and effective for the treatment of rectal lesions, but evidence is lacking concerning its application close to the dentate line. The aim of our study is to compare ESD and EMR for the treatment of epithelial rectal lesions involving the dentate line. METHODS: We identified all cases of endoscopic resections of rectal lesions involving the dentate line performed in two German high-volume centers between 2010 and 2022. Periinterventional and follow-up data were collected and retrospectively analyzed. RESULTS: We identified 68 ESDs and 62 EMRs meeting our inclusion criteria. ESD showed a significant advantage in en bloc resection rates (89.7% vs. 9.7%; P = 0.001) and complete resection rates (72.1% vs. 9.7%; P = 0.001). The overall curative resection rate was similar between both groups (ESD: 92.6%, EMR: 83.9%; P = 0.324), whereas in the subgroup of low-risk adenocarcinomas ESD was curative in 100% of the cases vs. 14% in the EMR group (P = 0.002). There was one local recurrence after ESD (1,5%) vs. 16 (25.8%) after EMR (P < 0.0001), and the EMR patients required an average of three further interventions. CONCLUSION: ESD is superior to EMR for the treatment of epithelial rectal lesions involving the dentate line and should be considered the treatment of choice.

Transanal Endoscopic Microsurgical Submucosal Dissection for Recurrent Rectal Adenomas.

BACKGROUND: The local resection of recurrent rectal adenomas is a technically challenging task associated with increased local recurrence rate. Transanal endoscopic microsurgical submucosal dissection (TEM-ESD) uses traction to better expose the fibrotic submucosal layer, and therefore, is a valuable alternative for the treatment of such lesions. The aim of our study was to assess the feasibility and outcomes of TEM-ESD for the resection of recurrent rectal adenomas. METHODS: We retrospectively analysed all TEM-ESD procedures performed in the Karlsruhe Municipal Hospital between 2012 and 2021 and isolated all cases of recurrent adenomas. Subsequently, we matched these cases 1:1 to TEM-ESD cases for primary rectal adenomas according to the size, localization, and histological type of the lesions and compared the outcomes between the two groups. RESULTS: We identified 19 cases matching our criteria. The median diameter of the lesions was 25 mm and the median operating time 39 min. Macroscopic en bloc resection was achieved in 100% of the cases and histological complete en bloc resection in 78.9%. There was 1 case of conservatively treated postoperative bleeding. After a median follow-up period of 36 months, there was one local recurrence. After comparing those findings to the outcomes of TEM-ESD for primary rectal lesions, we found no significant differences on total operating time, complete en bloc resection rates, adverse events, and local recurrence. CONCLUSION: TEM-ESD is a feasible therapeutic option for the resection of recurrent rectal adenomas, offering short operating times as well as high en bloc resection and low recurrence rates.

Transanal endoscopic microsurgical submucosal dissection (TEM-ESD) for rectal adenomas: a retrospective cohort study of 145 consecutive cases.

PURPOSE: Transanal endoscopic microsurgery (TEM) and endoscopic submucosal dissection (ESD) are currently the two most popular methods for resecting large rectal adenomas en bloc. However, damage to the mesorectum in the case of TEM, plus the technical challenges and long procedure times of flexible ESD, are major disadvantages of these procedures. Transanal endoscopic microsurgical submucosal dissection (TEM-ESD) is a new technique, combining the ergonomic features of TEM with the minimally invasive approach of ESD. The aim of our study was to assess the feasibility and safety of TEM-ESD for resection of large rectal adenomas. METHODS: We retrospectively analyzed all TEM-ESD procedures performed in Karlsruhe Municipal Hospital between 2012 and 2019, isolated all cases of adenomas, and analyzed the perioperative and follow-up data of the patients. RESULTS: We identified 145 cases matching our criteria. The median size of the lesions was 4.2 cm, and the median operating time was 45 min. The en bloc resection rate was 100%, and the complete en bloc resection rate was 78.6%. The overall morbidity rate was 6.9%. In a median follow-up period of 24 months, there was a local recurrence in 4.8% of the cases. CONCLUSIONS: TEM-ESD is a safe and feasible therapeutic option for resecting large rectal adenomas, offering high en bloc resection and low recurrence rates combined with short operating time and low morbidity. TRIAL REGISTRATION NUMBER (CLINICALTRIALS.GOV): NCT04870931.

Local full-thickness excision for sessile adenoma and cT1-2 rectal cancer: long-term oncological outcome.

PURPOSE: We analyzed all patients who underwent local transanal surgery at our institution to determine oncological outcomes and perioperative risk. METHODS: In 1997, we developed a prospective protocol for rectal tumors: transanal local full-thickness excision was considered curative in patients with benign adenoma and early cancers. In this analysis, 404 patients were included. To analyze survival, only those patients exposed to the risk of dying for at least 5 years were considered for the study. RESULTS: The final pathological analysis revealed that 262 (64.8%) patients had benign lesions, whereas 142 had malignant lesions. Postoperative complications were recorded in 12.6%. At the median time of 21 months, 14% of the adenomas and 12% of cancers had recurred, half of which were surgically resected. The overall 5-year survival rate was 94%. CONCLUSION: With similar outcomes and significantly lower morbidity, we found local surgery to be an adequate alternative to radical surgery in selected cases of early rectal cancer.

Endoscopic full-thickness dissection (EFTD) in the rectum: a case series.

BACKGROUND: Rectal endoscopic full- thickness dissection (EFTD) using a flexible colonoscope is an alternative to the well-established trans-anal endoscopic microsurgery (TEM) and the trans-anal minimally invasive surgery (TAMIS) techniques for resecting dysplastic or malignant rectal lesions. This study evaluated EFTD safety by analyzing outcomes of the first patients to undergo rectal EFTD at the University Hospital of North-Norway. METHODS: The first 10 patients to undergo rectal EFTD at the University Hospital of North-Norway April, 2016 and January, 2021, were included in the study. The procedural indications for EFTD were therapeutic resection of non-lifting adenoma, T1 adenocarcinoma (AC), recurrent neuroendocrine tumor (NET) and re-excision of a T1-2 AC. RESULTS: EFTD rectal specimen histopathology revealed three ACs, five adenomas with high-grade dysplasia (HGD), one NET and one benign lesion. Six procedures had negative lateral and vertical resection margins and in three cases lateral margins could not be evaluated due to piece-meal dissection or heat damaged tissue. Two patients experienced delayed post-procedural hemorrhage, one of whom also presented with a concurrent post-procedural infection. No serious complications occurred. CONCLUSION: Preliminary results from this introductory trial indicate that EFTD in the rectum can be conducted with satisfactory perioperative results and low risk of serious complications.

Transanal endoscopic microsurgical submucosal dissection: Are there advantages over conventional ESD?

INTRODUCTION: Transanal endoscopic microsurgical submucosal dissection (TEM-ESD) is a technique that has been recently described for the treatment of large rectal adenomas and early rectal cancer. The purpose of our study is to compare TEM-ESD with flexible endoscopic submucosal dissection (ESD) in an experimental, ex vivo porcine model. MATERIAL AND METHODS: We used TEM-ESD and flexible ESD to resect a total of 100 standardized 4 × 4cm lesions in an ex vivo porcine stomach model, performing 50 resections with each technique. Total procedure time, en bloc resection rate, injuries of the muscularis propria, perforation rate and learning curve were analysed. RESULTS: TEM-ESD was associated with a significantly shorter total procedure time in comparison to ESD (19 min vs. 33 min, p < .001). The rates of en bloc resection, injury of the muscularis propria layer, and perforation were the same in both groups. The learning curve of TEM-ESD was shallower than that of ESD. CONCLUSION: TEM-ESD showed an advantage over ESD in terms of procedure time and learning curve, with similar en bloc resection rates and safety profile in our experimental model.

Analysis of the therapeutic effect of transanal endoscopic microsurgery on large rectal adenoma.

Purpose: Rectal adenoma, a pre-cancerous lesion, is one of the indications for transanal endoscopic microsurgery (TEM). TEM has its unique advantages in the treatment of rectal adenomas. However, there are few reports on the therapeutic effects of large rectal adenoma (LRA). The objective of this study was to investigate the value of TEM in the treatment of LRA. Materials and Methods: We collected data from patients who underwent surgery at our center from 2007 to 2017. The postoperative pathology of all patients was rectal adenoma and the diameter of the adenoma was 3 cm or greater. Moreover, all patients underwent TEM. We followed up to observe the incidence of no wound healing, rectal stenosis and recurrence rate of rectal adenoma. The risk factors of adenoma recurrence and wound healing were analysed using single- and multiple-factor analysis. Results: The clinicopathological data of 85 patients with LRA were collected through a pre-set table. During the follow-up period, eight patients were lost to follow-up, and three (3.90%) patients developed rectal stenosis. After 2 years of post-operative follow-up, 20 (25.97%) patients had recurrence and 57 (74.03%) patients had no recurrence. Multivariate analysis showed that positive margin was an independent risk factor for recurrence of adenoma. Conclusions: TEM is feasible in the treatment of large rectal tumours in Centers of Expertise with the technique.

Multiparametric MRI-based machine learning models for preoperatively predicting rectal adenoma with canceration.

OBJECTIVES: To propose multiparametric MRI-based machine learning models and assess their ability to preoperatively predict rectal adenoma with canceration. MATERIALS AND METHODS: A total of 53 patients with postoperative pathology confirming rectal adenoma (n = 29) and adenoma with canceration (n = 24) were enrolled in this retrospective study. All patients were divided into a training cohort (n = 42) and a test cohort (n = 11). All patients underwent preoperative pelvic MR examination, including high-resolution T2-weighted imaging (HR-T2WI) and diffusion-weighted imaging (DWI). A total of 1396 radiomics features were extracted from the HR-T2WI and DWI sequences, respectively. The least absolute shrinkage and selection operator (LASSO) was utilized for feature selection from the radiomics feature sets from the HR-T2WI and DWI sequences and from the combined feature set with 2792 radiomics features incorporating two sequences. Five-fold cross-validation and two machine learning algorithms (logistic regression, LR; support vector machine, SVM) were utilized for model construction in the training cohort. The diagnostic performance of the models was evaluated by sensitivity, specificity and area under the curve (AUC) and compared with the Delong's test. RESULTS: Ten, 8, and 25 optimal features were selected from 1396 HR-T2WI, 1396 DWI and 2792 combined features, respectively. Three group models were constructed using the selected features from HR-T2WI (ModelT2), DWI (ModelDWI) and the two sequences combined (Modelcombined). Modelcombined showed better prediction performance than ModelT2 and ModelDWI. In Modelcombined, there was no significant difference between the LR and SVM algorithms (p = 0.4795), with AUCs in the test cohort of 0.867 and 0.900, respectively. CONCLUSIONS: Multiparametric MRI-based machine learning models have the potential to predict rectal adenoma with canceration. Compared with ModelT2 and ModelDWI, Modelcombined showed the best performance. Moreover, both LR and SVM have equal excellent performance for model construction.

Predictors of rectal adenoma recurrence following transanal endoscopic surgery: a retrospective cohort study.

BACKGROUND: Transanal endoscopic surgery is the treatment of choice in patients with rectal adenomas that cannot be removed by endoscopy. However, the risk of adenoma recurrence and optimal surveillance is not well defined. The objective of this study was to characterize the timing and frequency of rectal adenoma recurrence after removal by transanal endoscopic surgery and identify recurrence risk factors. METHODS: This was a retrospective cohort study of a large, single-center academic institution in Vancouver, BC, Canada. Consecutive patients between May 1, 2007 and September 30, 2016 with pathology-confirmed rectal adenoma treated by primary excision with transanal endoscopic surgery and at least 1 year of confirmed endoscopic follow-up were included. Main outcome measures were recurrence rates following TEM as well as risk factors for recurrence. RESULTS: 297 patients met inclusion criteria. The mean age of patients was 66.5 ± 11.5 years and 57.9% were male. Median follow-up was 623 (range 56-3841) days. A total of 62 recurrences occurred in 41 patients (13.8% of study population). Recurrences were managed with repeat transanal endoscopic surgery or endoscopic resection 67.7% and 25.8% of the time, respectively. Radical resection was required for adenocarcinoma in 4 patients. Recurrence-free survival rates were 93.4% at 1 year, 86.2% at 2 years, and 73.1% at 5 years. After adjusting for individual surgeons, adenoma height, size > 3 cm, high-grade dysplasia, positive margins, and management of the rectal defect, patients who underwent surgery in the latter 5 years of the study had lower odds of recurrence (OR 0.42, 95% CI 0.19, 0.93, p = 0.03). CONCLUSIONS: Rectal adenomas managed by transanal endoscopic surgery are lesions at high risk for recurrence; surveillance should be performed within the first 2 years and continued for a total of at least 5 years. Most recurrences can be successfully treated with repeat TEM or endoscopic resection.

A multi-centre randomized controlled trial of open vs closed management of the rectal defect after transanal endoscopic microsurgery.

AIM: Transanal endoscopic microsurgery (TEM) is a technically challenging strategy that allows expanded indications for local excision of rectal lesions. Transluminal suturing is difficult, so open management of the resultant defect is appealing. Expert opinion suggests there is more pain when the defect is left open. The aim of this study was to determine if closure of the defect created during full thickness excision of rectal lesions with TEM leads to less postoperative pain compared to leaving the defect open. METHOD: At the time of surgery, patients undergoing a full thickness TEM were randomized to sutured (TEM-S) or open (TEM-O) management of the rectal defect. At five Canadian academic colorectal surgery centres, experienced TEM surgeons enrolled patients ≥ 18 years treated by full thickness TEM. The primary outcome was postoperative pain measured by the visual analogue scale. Secondary outcomes included postoperative pain medication use and 30-day postoperative complications, including bleeding, infection and hospital readmission. RESULTS: Between March 2012 and October 2013, 50 patients were enrolled and randomized to sutured (TEM-S, n = 28) or open (TEM-O, n = 22) management of the rectal defect. There was no difference between the two study groups in postoperative pain on postoperative day 1 (2.8 vs 2.6, P = 0.76), day 3 (2.8 vs 2.1, P = 0.23) and day 7 (2.8 vs 1.7, P = 0.10). CONCLUSION: In this multicentre randomized controlled trial, there was no difference in postoperative pain between sutured or open defect management in patients having a full thickness excision with TEM.

Randomised controlled trial of transanal endoscopic microsurgery versus endoscopic mucosal resection for large rectal adenomas (TREND Study).

OBJECTIVE: Non-randomised studies suggest that endoscopic mucosal resection (EMR) is equally effective in removing large rectal adenomas as transanal endoscopic microsurgery (TEM), but EMR might be more cost-effective and safer. This trial compares the clinical outcome and cost-effectiveness of TEM and EMR for large rectal adenomas. DESIGN: Patients with rectal adenomas ≥3 cm, without malignant features, were randomised (1:1) to EMR or TEM, allowing endoscopic removal of residual adenoma at 3 months. Unexpected malignancies were excluded postrandomisation. Primary outcomes were recurrence within 24 months (aiming to demonstrate non-inferiority of EMR, upper limit 10%) and the number of recurrence-free days alive and out of hospital. RESULTS: Two hundred and four patients were treated in 18 university and community hospitals. Twenty-seven (13%) had unexpected cancer and were excluded from further analysis. Overall recurrence rates were 15% after EMR and 11% after TEM; statistical non-inferiority was not reached. The numbers of recurrence-free days alive and out of hospital were similar (EMR 609±209, TEM 652±188, p=0.16). Complications occurred in 18% (EMR) versus 26% (TEM) (p=0.23), with major complications occurring in 1% (EMR) versus 8% (TEM) (p=0.064). Quality-adjusted life years were equal in both groups. EMR was approximately €3000 cheaper and therefore more cost-effective. CONCLUSION: Under the statistical assumptions of this study, non-inferiority of EMR could not be demonstrated. However, EMR may have potential as the primary method of choice due to a tendency of lower complication rates and a better cost-effectiveness ratio. The high rate of unexpected cancers should be dealt with in further studies.

Transanal endoscopic microsurgery for giant benign rectal tumours: is large size a contraindication?

PURPOSE: The purpose of this study is to look at our early postoperative results, recurrence rates and need for further radical surgery in treating large (> 5 cm) rectal tumours by transanal endoscopic microsurgery (TEM). METHODS: Patients who underwent TEM for rectal tumours greater than 5 cm were included. Tumour diameter was determined based on fresh specimen measurements. We recorded the demographics, operative details, final pathology, length of hospital stay, complications and recurrence rates. RESULTS: Mean tumour size was 5.9 ± 1.5 cm. 68.4% of tumours (13/19) were in the middle part of the rectum. Three patients (15.8%) developed postoperative complications: two had postoperative bleeding (10.5%), one had wound dehiscence (5.3%). Three patients had involved margins (15.8%). After a median follow up of 25.2 months, there were two recurrences (10.5%). One patient developed rectal cancer 6 years after removal of rectal adenoma. CONCLUSION: TEM is feasible and safe for the treatment of giant benign rectal tumours. It may be an alternative method for proctectomy in selected patients.

Peritoneal perforation is less a complication than an expected event during transanal endoscopic microsurgery: experience from 194 consecutive cases.

BACKGROUND: Indications for transanal endoscopic microsurgery (TEM) have been extended to technically challenging tumors, which may be associated with an increased risk of peritoneal perforation (PP). The aim of the present study was to investigate the occurrence, management and outcome of PP in patients having TEM. METHODS: All the patients who had TEM for rectal adenoma or adenocarcinoma in our unit were included. Patients in whom PP occurred (Group A) were compared to those without PP (Group B). RESULTS: From 2007 to 2015, 194 TEM (116 men, median age 66 [range 21-100] years) were divided into Groups A (n = 28, 14%) and B (n = 166). The latter group included four patients, in whom a laparoscopy did not confirm suspicion of PP made during TEM. In 2 of 28 patients (7%), the diagnosis of PP was made postoperatively during reoperation for peritonitis. For the 26 other patients (93%), routine exploratory laparoscopy was performed with suture of the peritoneal defect on the pouch of Douglas in 24 cases and a rectal suture alone in 2 cases. Independent predictive factors for PP were: distance from the anal verge >10 cm (OR = 3.6), circumferential tumor (OR = 3.0) and anterior location (OR = 2.7). Hospital stay was significantly longer in Group A (7.5 [3-31] days) than in Group B (4 [1-38] days; p < 0.0001), whereas there was no significant difference regarding postoperative morbidity and recurrence rate. CONCLUSIONS: Our results suggested that PP is not a very rare event during TEM, especially in anterior, circumferential and/or high rectal tumors. Laparoscopic treatment of PP is feasible and safe. The occurrence of PP is not associated with poor oncologic results.

Indications and Outcomes From 32 Consecutive Patients for the Treatment of Rectal Lesions by Transanal Minimally Invasive Surgery.

BACKGROUND: The aim of this study was to evaluate the feasibility, safety, perioperative morbidity, and short-term outcomes of the transanal minimally invasive surgery (TAMIS) technique. METHODS: This is a descriptive review of prospectively collected data from 32 consecutive patients who underwent TAMIS procedures in our colorectal unit over a 40-month period. GelPOINT Path port was used in all cases. Demographic data, indications, tumor characteristics, morbidity, and follow-up data were collected. Primary endpoints included feasibility, safety, perioperative morbidity, and resection quality. RESULTS: Fifteen adenomas, 12 carcinomas, 1 gastrointestinal stromal tumor, and 1 neuroendocrine tumor were locally excised. Additionally, 3 pelvic abscesses were drained transanally using the TAMIS port. Mean distance from the anal verge was 5.6 ± 1.5 cm. Early postoperative complications occurred in 22%, with only one case of major complication (3.1%) requiring reoperation, and no postoperative mortality. Four carcinomas were understaged (33.3%) and 1 adenoma overstaged (6.7%) preoperatively. Three carcinomas were not suspected preoperatively (25%). Microscopic positive lateral margin was found in one case, and no affected deep margin was found. Fragmentation rate was 6.9%, 2 cases, both lesions over 20 cm2. In cases of fit patients with high-risk carcinomas, 2 underwent immediate salvage surgery and another 2 refused and were treated with adjuvant radiotherapy. With a median follow-up of 26 months, the overall recurrence rate was 10.3%, 1 adenoma and 2 carcinomas. CONCLUSION: TAMIS seems to be a safe and reproducible procedure for local excision of well-selected rectal lesions with low morbidity and good functional outcomes.

Transanal endoscopic microsurgery for giant circumferential rectal adenomas.

AIM: Transanal endoscopic microsurgery (TEM) was originally invented by Buess et al. (Chirurg, 1984, 55, 677-80) for the treatment of infraperitoneal rectal adenomas. Its indications have progressively expanded to include larger and more advanced lesions. The aim of the study was to report the results of TEM used for the treatment of circumferential rectal lesions. METHOD: We retrospectively reviewed the medical records of 17 consecutive patients [median age 69 (32-89) years; nine men] who underwent TEM for a circumferential rectal lesion in our department between September 2010 and January 2015. RESULTS: The median distance from the anal verge was 4 (3-11) cm, the median longitudinal extent was 7 (3-10) cm and the median surface area was 75 (40-255) cm(2) . An end-to-end anastomosis without proximal bowel mobilization was completed endoscopically in all cases. The median operating time was 120 (40-240) min. Persistent, endoscopically uncontrollable endoluminal bleeding in one patient was successfully treated with a second TEM procedure. One patient underwent preoperative radiotherapy for adenocarcinoma detected at the preoperative assessment. Surgical histology showed a pT3 cancer in one patient who refused further surgery, a pT2 cancer in two who subsequently underwent abdominoperineal resection, a pT1 cancer in four and a ypT0 in one patient. All are at present free of disease. No patients developed faecal incontinence or urinary or sexual dysfunction. Four patients required endoscopic balloon dilatation for stenosis. CONCLUSION: Transanal endoscopic microsurgery is a feasible and safe technique for large circumferential lesions with a satisfactory outcome. Preoperative staging may be inaccurate.

[TEO: minimally invasive surgery of the rectum. A short review]. / TEO: Minimálisan invazív rectumsebészet. Rövid áttekintés.

The equipment and technique of transanal endoscopic microsurgery was developed by Buess in the early 80s. The technique was more refined, and the indication was widened since then. Excellent oncological results can be achieved with good patient selection with this less invasive technique and the complication rate is very low in contrast to conventional techniques. Nowadays the transanal endoscopic microsurgery is the "gold standard" in the treatment of benign lesions and low risk T1 cancer of the rectum.

[Is it radical enough? Transanal endoscopic microsurgery for the treatment of rectal neoplasia -- clinicopathological viewpoint]. / Kelloen radikális? Transanalis endoscopos mikrosebészeti technika szerepe a rectum daganatainak ellátásában -- egy év tapasztalatainak klinikopatológiai értékelése.

The transanal endoscopic microsurgery (TEM) provides lower relapse and complication rate for the the surgical treatment of the neoplasms of the middle and lower third of the rectum in selected cases. Hence, it can be an alternative method of the conventional approaches, if it does not compromise oncological radicality. The TEM procedure has been started at the 1st Department of Surgery, Semmelweis University in the fall of 2013. In this short study we have evaluated the clinicopathological characteristics of patients undergoing TEM between September 2013 and September 2014. Fourty-four patients were included in our retrospective analysis. 12 patients had low grade adenoma, 14 patients had high grade adenoma, 17 patients had invasive adenocarcinoma, while one was operated for a neuroendocrine tumor. There was no difference in the size of neoplasms between the low and high grade adenomas or adenocarcinomas (p = 0.210), tumors below the size of 30 mm or over 30 mm displayed no significant difference either (p = 0.424). The surgical margins were free of tumor in 41 cases (95.3%). In 13 out of 44 cases the preoperative histology proposed a lower grade neoplasm than the final report (p < 0.001). These results demonstrate that the surgical treatment of large adenomas with TEM technique, which involves excision of the whole bowel wall, is more appropriate than the fractionated removal or polypectomy supplemented by mucosectomy. The pT2 stage tumours might be subjected to the TEM method in selected cases (e.g. following neoadjuvant treatment or palliative care), but this has to be confirmed with prospecively evaluated large series clinical studies which are currently ongoing.

Diagnostic advantages of transrectal ultrasound with gastrointestinal agent instillation for rectal adenoma and early-stage rectal cancer: comparison of conventional transrectal ultrasound techniques.

Background: Despite being a major focus of medical research for decades, rectal cancer remains a major threat to human health. This study aimed to compare and analyze the diagnostic value of transrectal ultrasonography (TRUS) for rectal adenoma and early-stage rectal cancer before and after gastrointestinal agent instillation. Methods: In this prospective study, patients diagnosed with rectal adenomas and early-stage rectal cancer by ultrasound were randomly selected for inclusion. All patients underwent ultrasound examination at the Outpatient Department of the First Affiliated Hospital of China Medical University and underwent surgical treatment at the First Affiliated Hospital of China Medical University. Patients with a lesion located 13 cm or more from the edge of the anus, or history of surgery, and a history of radiation and chemotherapy were excluded. A gastrointestinal agent was directly instilled into the rectal cavity during conventional TRUS to compare and analyze the display of rectal lesions before and after such instillation and to evaluate the infiltration depth of rectal lesions. These findings were compared to the pathological findings to determine the diagnostic efficacy. Results: Both the conventional TRUS and TRUS with gastrointestinal agent instillation were able to show the rectal wall structure and rectal lesions; the detection rate of rectal lesions of the former was 75.0%, and that of the latter was 97.1% (P<0.001). Of the 27 rectal adenomas, conventional TRUS detected 10, and TRUS with gastrointestinal agent instillation detected 25 lesions. The accuracy [90.54%; 95% confidence interval (CI): 81.48-96.11%; P=1.05E-08], specificity (87.88%; 95% CI: 71.80-96.60%; P=1.09E-05), and sensitivity (92.68%; 95% CI: 80.08-98.47%; P=1.05E-08) of TRUS in diagnosing early-stage rectal cancer were consistent with the pathological findings (P<0.001). The accuracy (95.95%, 95% CI: 88.61-99.16%; P=3.82E-11), specificity (93.94%, 95% CI: 79.77-99.26%; P=1.31E-07), and sensitivity (97.56%, 95% CI: 87.15-99.94%; P=3.82E-11) of TRUS after gastrointestinal agent infusion in diagnosing early-stage rectal cancer were consistent with the pathological findings (P<0.001). The specificity (87.88%; 95% CI: 71.80-96.60%; P=1.09E-05) of TRUS in diagnosing rectal adenomas was consistent with the pathological finding (P<0.001), but the accuracy (65%; 95% CI: 51.60-76.87%; P=0.25) and sensitivity (37.04%, 95% CI: 19.40-57.63%; P=0.25) were not (P>0.05). Meanwhile, the accuracy (93.33%; 95% CI: 83.80-98.15%; P=5.65E-06), specificity (93.94; 95% CI: 79.77-99.26%; P=1.31E-07), and sensitivity (92.59%; 95% CI: 75.71-99.09%; P=5.65E-06) of TRUS after gastrointestinal agent infusion in diagnosing rectal adenomas were consistent with the pathological findings (P<0.001). Conclusions: TRUS with gastrointestinal agent instillation had significantly improved accuracy in diagnosing early-stage rectal cancer and detecting intrarectal adenomatoid lesions.

Revisiting the Trans-Sacral Approach for Large Rectal Adenomas, Surgical Technique, and Oncological Outcome: a Case Series.

The standard oncologic surgeries for rectal carcinoma are radical trans abdominal procedures, However, these radical procedures are not suitable for large rectal adenomas. The transsacral approach for rectal adenoma was first described by Kraske and since then it has been utilized for various benign conditions of low and mid-rectum as well as for certain cancers. We are presenting a series of 5 consecutive cases of trans-sacral resection done in the past 7 years between January, 2016, until June, 2023, at the Department of Surgical Oncology, Cancer Research Institute, HIMS Dehradun, for large mid- and lower rectal adenoma. There were 5 patients who underwent transsacral excision of rectal adenoma. Three patients were male and 2 were female. All the patients underwent surgery after confirming the diagnosis of adenoma and metastatic work up. The postoperative histopathological examination showed adenocarcinoma infiltrating submucosa (T1) in one patient; however, other 4 patients had adenoma reconfirmed. The transsacral approach may not be the method of choice for the rectal carcinoma but it is a very useful surgical alternative to the large rectal adenoma where there is no invasive component and which cannot be managed by any other methods.

Endoscopic Submucosal Dissection, Endoscopic Mucosal Resection, and Transanal Minimally Invasive Surgery for the Management of Rectal and Anorectal Lesions: A Narrative Review.

Endoscopic submucosal dissection (ESD), endoscopic mucosal resection (EMR), and transanal minimally invasive surgery (TAMIS) are modern techniques that now play a crucial role in the treatment of colorectal lesions. ESD is a minimally invasive endoscopic procedure that allows for the resection of lesions of any size in a single piece, with clear advantages regarding oncological outcomes and recurrences. However, it is a complex technique, requiring high endoscopic skills, expertise, and specialized training, with higher rates of adverse events expected compared with EMR. EMR is another endoscopic technique used to remove superficial gastrointestinal tumors, particularly those that are limited to the mucosal layer. It is a faster and more accessible procedure, with fewer adverse events, although it only allows for an en-bloc resection of lesions measuring 15-20 mm. TAMIS is a minimally invasive surgical technique used to remove rectal tumors, involving the insertion of a single-port device through the anus, allowing for a better visualization and removal of the tumor with minimal disruption. This article reviews the current applications and evidence regarding these techniques, in search for the most adequate treatment for the removal of lesions in the rectum and anorectal junction, as these locations possess distinct characteristics that demand a more specific approach.