Surgeon assessment of significant rectal polyps using white light endoscopy alone and in comparison to fluorescence-augmented AI lesion classification.

PURPOSE: Perioperative decision making for large (> 2 cm) rectal polyps with ambiguous features is complex. The most common intraprocedural assessment is clinician judgement alone while radiological and endoscopic biopsy can provide periprocedural detail. Fluorescence-augmented machine learning (FA-ML) methods may optimise local treatment strategy. METHODS: Surgeons of varying grades, all performing colonoscopies independently, were asked to visually judge endoscopic videos of large benign and early-stage malignant (potentially suitable for local excision) rectal lesions on an interactive video platform (Mindstamp) with results compared with and between final pathology, radiology and a novel FA-ML classifier. Statistical analyses of data used Fleiss Multi-rater Kappa scoring, Spearman Coefficient and Frequency tables. RESULTS: Thirty-two surgeons judged 14 ambiguous polyp videos (7 benign, 7 malignant). In all cancers, initial endoscopic biopsy had yielded false-negative results. Five of each lesion type had had a pre-excision MRI with a 60% false-positive malignancy prediction in benign lesions and a 60% over-staging and 40% equivocal rate in cancers. Average clinical visual cancer judgement accuracy was 49% (with only 'fair' inter-rater agreement), many reporting uncertainty and higher reported decision confidence did not correspond to higher accuracy. This compared to 86% ML accuracy. Size was misjudged visually by a mean of 20% with polyp size underestimated in 4/6 and overestimated in 2/6. Subjective narratives regarding decision-making requested for 7/14 lesions revealed wide rationale variation between participants. CONCLUSION: Current available clinical means of ambiguous rectal lesion assessment is suboptimal with wide inter-observer variation. Fluorescence based AI augmentation may advance this field via objective, explainable ML methods.

Diagnostic performance of Node Reporting and Data System (Node-RADS) for assessing mesorectal lymph node in rectal cancer by CT.

BACKGROUND: To compare the diagnostic performance of the Node-RADS scoring system and lymph node (LN) size in preoperative LN assessment for rectal cancer (RC), and to investigate whether the selection of size as the primary criterion whereas morphology as the secondary criterion for LNs can be considered the preferred method for clinical assessment. METHODS: Preoperative CT data of 146 RC patients treated with radical resection surgery were retrospectively analyzed. The Node-RADS score and short-axis diameter of size-prioritized LNs and the morphology-prioritized LNs were obtained. The correlations of Node-RADS score to the pN stage, LNM number and lymph node ratio (LNR) were investigated. The performances on assessing pathological lymph node metastasis were compared between Node-RADS score and short-axis diameter. A nomogram combined the Node-RADS score and clinical features was also evaluated. RESULTS: Node-RADS score showed significant correlation with pN stage, LNM number and LNR (Node-RADS of size-prioritized LN: r = 0.600, 0.592, and 0.606; Node-RADS of morphology-prioritized LN: r = 0.547, 0.538, and 0.527; Node-RADSmax: r = 0.612, 0.604, and 0.610; all p < 0.001). For size-prioritized LN, Node-RADS achieved an AUC of 0.826, significantly superior to short-axis diameter (0.826 vs. 0.743, p = 0.009). For morphology-prioritized LN, Node-RADS exhibited an AUC of 0.758, slightly better than short-axis diameter (0.758 vs. 0.718, p = 0.098). The Node-RADS score of size-prioritized LN was significantly better than that of morphology-prioritized LN (0.826 vs. 0.758, p = 0.038). The nomogram achieved the best diagnostic performance (AUC = 0.861) than all the other assessment methods (p < 0.05). CONCLUSIONS: The Node-RADS scoring system outperforms the short-axis diameter in predicting lymph node metastasis in RC. Size-prioritized LN demonstrates superior predictive efficacy compared to morphology-prioritized LN. The nomogram combined the Node-RADS score of size-prioritized LN with clinical features exhibits the best diagnostic performance. Moreover, a clear relationship was demonstrated between the Node-RADS score and the quantity-dependent pathological characteristics of LNM.

Management of internal iliac and obturator lymph nodes in mid-low rectal cancer.

In rectal cancer treatment, the diagnosis and management of lateral pelvic lymph nodes (LLN) are critical for preventing local recurrence. Over time, scholars have reached a consensus: when imaging suggests LLN metastasis, combining neoadjuvant chemoradiotherapy (nCRT) with selective LLN dissection (LLND) can mitigate the risk of recurrence. Selective LLND typically encompasses lymph nodes in the internal iliac and obturator regions. Recent studies emphasize distinctions between internal iliac and obturator lymph nodes regarding prognosis and treatment outcomes, prompting the need for differentiated diagnostic and treatment approaches.

Hemorrhagic shock secondary to ruptured hypogastric artery pseudoaneurysm. A rare complication of colorectal anastomotic leakage.

Massive bleeding due to rupture of hypogastric artery pseudoaneurysm is an exceptional complication of colorectal anastomotic leakage. A 41-year-old woman with history of rectal cancer surgery, who debuted with massive rectorrhagia and hypovolemic shock due to rupture of a hypogastric artery pseudoaneurysm as a late complication of a colorectal anastomosis leak. The ruptured hypogastric artery pseudoaneurysm should be taken into account in the differential diagnosis of patients with massive rectorrhagia and history of colorectal anastomosis leak. Endovascular embolization is considered the first-line treatment.

La hemorragia masiva por rotura de un pseudoaneurisma de la arteria hipogástrica es una complicación muy rara de la fuga anastomótica colorrectal. Mujer de 41 años con antecedentes de cirugía por cáncer de recto, que debutó con un cuadro de rectorragias masivo y shock hipovolémico secundario a la rotura de un pseudoaneurisma de la arteria hipogástrica como complicación tardía de una fuga de la anastomosis colorrectal. La rotura de un pseudoaneurisma de la arteria hipogástrica se debe tener presente en el diagnostico diferencial de pacientes con rectorragia masiva y antecedentes de dehiscencia de anastomosis colorrectal. La embolización endovascular es actualmente el tratamiento de elección.

Evaluation of Neoadjuvant Chemoradiotherapy Response in Rectal Cancer Using MR Images and Deep Learning Neural Networks.

INTRODUCTION: The aim of the study was to develop deep-learning neural networks to guide treatment decisions and for the accurate evaluation of tumor response to neoadjuvant chemoradiotherapy (nCRT) in rectal cancer using magnetic resonance (MR) images. METHODS: Fifty-nine tumors with stage 2 or 3 rectal cancer that received nCRT were retrospectively evaluated. Pathological tumor regression grading was carried out using the Dworak (Dw-TRG) guidelines and served as the ground truth for response predictions. Imaging-based tumor regression grading was performed according to the MERCURY group guidelines from pre-treatment and post-treatment para-axial T2-weighted MR images (MR-TRG). Tumor signal intensity signatures were extracted by segmenting the tumors volumetrically on the images. Normalized histograms of the signatures were used as input to a deep neural network (DNN) housing long short-term memory (LSTM) units. The output of the network was the tumor regression grading prediction, DNN-TRG. RESULTS: In predicting complete or good response, DNN-TRG demonstrated modest agreement with Dw-TRG (Cohen's kappa= 0.79) and achieved 84.6% sensitivity, 93.9% specificity, and 89.8% accuracy. MR-TRG revealed 46.2% sensitivity, 100% specificity, and 76.3% accuracy. In predicting a complete response, DNN-TRG showed slight agreement with Dw-TRG (Cohen's kappa= 0.75) with 71.4% sensitivity, 97.8% specificity, and 91.5% accuracy. MR-TRG provided 42.9% sensitivity, 100% specificity, and 86.4% accuracy. DNN-TRG benefited from higher sensitivity but lower specificity, leading to higher accuracy than MR-TRG in predicting tumor response. CONCLUSION: The use of deep LSTM neural networks is a promising approach for evaluating the tumor response to nCRT in rectal cancer.

Minimally invasive approach for retrorectal tumors above and below S3: a multicentric tertiary center retrospective study (MiaRT study).

BACKGROUND: Retrorectal tumors are uncommon lesions developed in the retrorectal space. Data on their minimally invasive resection are scarce and the optimal surgical approach for tumors below S3 remains debated. METHODS: We performed a retrospective review of consecutive patients who underwent minimally invasive resection of retrorectal tumors between 2005 and 2022 at two tertiary university hospital centers, by comparing the results obtained for lesions located above or below S3. RESULTS: Of over 41 patients identified with retrorectal tumors, surgical approach was minimally invasive for 23 patients, with laparoscopy alone in 19, with transanal excision in 2, and with combined approach in 2. Retrorectal tumor was above S3 in 11 patients (> S3 group) and below S3 in 12 patients (< S3 group). Patient characteristics and median tumor size were not significantly different between the two groups (60 vs 67 mm; p = 0.975). Overall median operative time was 131.5 min and conversion rate was 13% without significant difference between the two groups (126 vs 197 min and 18% vs 8%, respectively; p > 0.05). Final pathology was tailgut cyst (48%), schwannoma (22%), neural origin tumor (17%), gastrointestinal stromal tumor (4%), and other (19%). The 90-day complication rates were 27% and 58% in the > S3 and < S3 groups, respectively, without severe morbidity or mortality. After a median follow-up of 3.3 years, no recurrence was observed in both groups. Three patients presented chronic pain, three anal dysfunction, and three urinary dysfunction. All were successfully managed without reintervention. CONCLUSIONS: Minimally invasive surgery for retrorectal tumors can be performed safely and effectively with low morbidity and no mortality. Laparoscopic and transanal techniques alone or in combination may be recommended as the treatment of choice of benign retrorectal tumors, even for lesions below S3, in centers experienced with minimally invasive surgery.

Indocyanine green near-infrared fluorescence-assisted video endoscopic inguinal lymph node dissection for rectal cancer: a single-center experience.

BACKGROUND: This study aimed to investigate the safety and feasibility of indocyanine green near-infrared fluorescence (ICG-NIR) fluorescence-guided video-endoscopic inguinal lymphadenectomy (VEIL) for rectal cancer with inguinal lymph node metastasis (ILNM). METHODS: A retrospective analysis was conducted on 11 patients with rectal cancer who underwent ICG-NIR fluorescence-guided VEIL, assessing various parameters such as operation time, intraoperative bleeding, number of harvested lymph nodes, intraoperative and postoperative complications, and follow-up. RESULTS: Regarding surgical procedures for ILNM, unilateral surgery was performed in 7 cases (54.5%) and bilateral surgery in 4 cases (45.5%). Among these 15 ICG-NIR-guided VEIL surgeries in 11 patients, positive fluorescence visualization was achieved in 13 operations (86.7%). The median estimated blood loss was 10 ml, and the median operation time was 90 min. One case (6.7%) required conversion to open surgery. The median duration of the drain tube was 12 days, and the median length of postoperative hospital stay was 20 days. Postoperative complications were observed, including incisional infection in 2 cases (18.2%), lymphatic leakage in 5 cases (45.5%), urinary infection in 1 case (9.1%), and pneumonia in 3 cases (27.3%). Complications such as skin necrosis, lower limb venous thrombosis, lower limb swelling, or impaired movement were observed during the postoperative follow-up period. No cases of primary lesion, groin, or pelvic lymph node recurrence were observed. CONCLUSION: ICG-NIR fluorescence-guided VEIL is a safe and feasible surgical treatment for rectal cancer with ILNM. ICG fluorescence guidance holds promise as a more personalized and precise approach for VEIL in rectal cancer surgery.

Low anterior resection with transanal transection and single-stapled anastomosis: technical aspects and initial results.

BACKGROUND: Rectal cancer (RC) is a surgical challenge due to its technical complexity. The double-stapled (DS) technique, a standard for colorectal anastomosis, has been associated with notable drawbacks, including a high incidence of anastomotic leak (AL). Low anterior resection with transanal transection and single-stapled (TTSS) anastomosis has emerged to mitigate those drawbacks. METHODS: Observational study in which it described the technical aspects and results of the initial group of patients with medium-low RC undergoing elective laparoscopic total mesorectal excision (TME) and TTSS. RESULTS: Twenty-two patients were included in the series. Favourable postoperative outcomes with a median length of stay of 5 days and an AL incidence of 9.1%. Importantly, all patients achieved complete mesorectal excision with tumour-free margins, and no mortalities were reported. CONCLUSION: TTSS emerges as a promising alternative for patients with middle and lower rectal tumours, offering potential benefits in terms of morbidity reduction and oncological integrity compared with other techniques.

Low Hartmann's procedure versus abdominoperineal resection for rectal cancer, a propensity score matching cohort study.

BACKGROUND: This study aimed to compare low Hartmann's procedure (LHP) with abdominoperineal resection (APR) for rectal cancer (RC) regarding postoperative complications. METHOD: RC patients receiving radical LHP or APR from 2015 to 2019 in our center were retrospectively enrolled. Patients' demographic and surgical information was collected and analyzed. Propensity score matching (PSM) was used to balance the baseline information. The primary outcome was the incidence of major complications. All the statistical analysis was performed by SPSS 22.0 and R. RESULTS: 342 individuals were primarily included and 134 remained after PSM with a 1:2 ratio (50 in LHP and 84 in APR). Patients in the LHP group were associated with higher tumor height (P < 0.001). No significant difference was observed between the two groups for the incidence of major complications (6.0% vs. 1.2%, P = 0.290), and severe pelvic abscess (2% vs. 0%, P = 0.373). However, the occurrence rate of minor complications was significantly higher in the LHP group (52% vs. 21.4%, P < 0.001), and the difference mainly lay in abdominal wound infection (10% vs. 0%, P = 0.006) and bowel obstruction (16% vs. 4.8%, P = 0.028). LHP was not the independent risk factor of pelvic abscess in the multivariate analysis. CONCLUSION: Our data demonstrated a comparable incidence of major complications between LHP and APR. LHP was still a reliable alternative in selected RC patients when primary anastomosis was not recommended.

Treatment of Locally Advanced Rectal Cancer in the Era of Total Neoadjuvant Therapy: A Systematic Review and Network Meta-Analysis.

Importance: Treatment of locally advanced rectal cancer (LARC) involves neoadjuvant chemoradiotherapy plus total mesorectal excision and adjuvant chemotherapy. However, total neoadjuvant therapy (TNT) protocols (ie, preoperative chemotherapy in addition to radiotherapy) may allow better adherence and early treatment of distant micrometastases and may increase pathological complete response (pCR) rates. Objective: To assess the efficacy and tolerability of TNT protocols for LARC. Data Sources: MEDLINE, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), and Web of Science Core Collection electronic databases and ClinicalTrials.gov for unpublished studies were searched from inception to March 2, 2024. Study Selection: Randomized clinical trials including adults with LARC who underwent rectal resection as a final treatment were included. Studies including nonoperative treatment (watch-and-wait strategy), treatments other than rectal resection, immunotherapy, or antiangiogenic agents were excluded. Among the initially identified studies, 2.9% met the selection criteria. Data Extraction and Synthesis: Two authors independently screened the records and extracted data. Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA)-compliant pairwise and network meta-analyses with a random-effects model were performed in a frequentist framework, and the certainty of evidence was assessed according to the confidence in network meta-analysis approach. Main Outcomes and Measures: The primary outcome was pCR, defined as the absence of residual tumor at pathological assessment after surgery. Secondary outcomes included tolerability, toxic effects, perioperative outcomes, and long-term survival. Results: Of 925 records identified, 27 randomized clinical trials, including 13 413 adults aged 18 years or older (median age, 60.0 years [range, 42.0-63.5 years]; 67.2% male) contributed to the primary network meta-analysis. With regard to pCR, long-course chemoradiotherapy (L-CRT) plus consolidation chemotherapy (relative risk [RR], 1.96; 95% CI, 1.25-3.06), short-course radiotherapy (S-RT) plus consolidation chemotherapy (RR, 1.76; 95% CI, 1.34-2.30), and induction chemotherapy plus L-CRT (RR, 1.57; 95% CI, 1.09-2.25) outperformed standard L-CRT with single-agent fluoropyrimidine-based chemotherapy. Considering 3-year disease-free survival, S-RT plus consolidation chemotherapy (RR, 1.08; 95% CI, 1.01-1.14) and induction chemotherapy plus L-CRT (RR, 1.12; 95% CI, 1.01-1.24) outperformed L-CRT, in spite of an increased 5-year locoregional recurrence rate of S-RT plus consolidation chemotherapy (RR, 1.65; 95% CI, 1.03-2.63). Conclusions and Relevance: In this systematic review and network meta-analysis, 3 TNT protocols were identified to outperform the current standard of care in terms of pCR rates, with good tolerability and optimal postoperative outcomes, suggesting they should be recognized as first-line treatments.

Impact of lymph node retrieval on prognosis in elderly and non-elderly patients with T3-4/N+ rectal cancer following neoadjuvant therapy: a retrospective cohort study.

PURPOSE: The optimal number of lymph nodes to be resected in patients with rectal cancer who undergo radical surgery after neoadjuvant therapy remains controversial. This study evaluated the prognostic variances between elderly and non-elderly patients and determined the ideal number of lymph nodes to be removed in these patients. METHODS: The Surveillance, Epidemiology, and End Results (SEER) datasets were used to gather information on 7894 patients diagnosed with stage T3-4/N+ rectal cancer who underwent neoadjuvant therapy from 2010 to 2019. Of these patients, 2787 were elderly and 5107 were non-elderly. A total of 152 patients from the Longyan First Affiliated Hospital of Fujian Medical University were used for external validation. Overall survival (OS) and cancer-specific survival (CSS) were evaluated to determine the optimal quantity of lymph nodes for surgical resection. RESULTS: The study found significant differences in OS and CSS between elderly and non-elderly patients, both before and after adjustment for confounders (P < 0.001). The removal of 14 lymph nodes may be considered a benchmark for patients with stage T3-4/N+ rectal cancer who undergo radical surgery following neoadjuvant therapy, as this number provides a more accurate foundation for the personalized treatment of rectal cancer. External data validated the differences in OS and CSS and supported the 14 lymph nodes as a new benchmark in these patients. CONCLUSION: For patients with T3-4/N+ stage rectal cancer who undergo radical surgery following neoadjuvant therapy, the removal of 14 lymph nodes serves as a cutoff point that distinctly separates patients with a favorable prognosis from those with an unfavorable one.

Treatment trajectories of individuals diagnosed with rectal cancer: an interpretative phenomenological study.

Rectal cancer affects almost every aspect of an individual's daily life. However, there are gaps in understanding the complete spectrum of experiences spanning from diagnosis to recovery. Therefore, the aim of this study was to explore the treatment trajectories of individuals diagnosed with rectal cancer. Adopting an interpretative phenomenological approach, seven participants were recruited using purposive sampling. Data were collected using semi-structured, in-depth interviews that were digitally recorded, transcribed and analysed using thematic analysis. Study rigour was established following the four-dimension criteria of credibility, dependability, transferability and confirmability. Four prominent themes emerged from the participants' experiences of undergoing rectal cancer treatment: uncovering the inner battles; navigating the physical challenges; anchors of support and conquering the summit. These findings contribute to knowledge and practice by highlighting the importance of providing a comprehensive and individualised treatment plan for individuals that takes account of the physical and psycho-emotional implications of rectal cancer treatment.

"WATCH AND WAIT" STRATEGY IN RECTAL CANCER PATIENTS WITH A COMPLETE CLINICAL RESPONSE AFTER NEOADJUVANT CHEMORADIATION THERAPY: A SINGLE-CENTER EXPERIENCE.

BACKGROUND: The non-operative management of rectal adenocarcinoma (RA) after neoadjuvant chemoradiation therapy (nCRT) has gained increasing attention. The "Watch and Wait" ("W&W") strategy allows one to avoid surgery-related reduction in the quality of life due to permanent pelvic organ dysfunction or irreversible stoma. Still, the oncological safety of this strategy is under evaluation. AIM: To share a single-center experience of the "W&W" strategy. MATERIALS AND METHODS: The retrospective analysis of 125 patients who received nCRT in 2016-2021 was performed. Patients who met the European Society for Medical Oncology (ESMO, 2017) criteria of clinical complete response (cCR) and received non-operative management were analyzed. RESULTS: Ten patients (8%) were re-staged after nCRT as cCR and followed the "W&W" strategy. Patients' characteristics: 7 female, 3 male; mean age 67.3 years. Tumor characteristics: pre-treatment N+ was present in 7 cases; G1 adenocarcinoma in a majority of cases; mean tumor distance from the anal verge - 5.85 cm; mean tumor circumference - 71%; mean tumor length - 3.87 cm. The mean follow-up time was 30 months. Local regrowth or/and distant metastases developed in 3 cases. The 2-year disease-free survival was 70%. CONCLUSIONS: Most of the patients following the "W&W" strategy have benefited. However, to reduce the number of relapses, it is necessary to perform a more careful selection of patients.

[A Case of Consciousness Disorder Due to Hyperammonemia Induced by Modified FOLFOX6 for Multiple Liver Metastasis from Rectal Cancer].

A 74-year-old man underwent laparoscopic-assisted high anterior resection with D3 lymph node dissection for rectal cancer, which was simultaneously accompanied by multiple liver metastases. The patient received mFOLFOX6 therapy for liver metastases 1 month after the surgery. Anorexia, nausea, and vomiting appeared on the second day of treatment. On the third day of treatment, impaired consciousness(JCS Ⅱ-20)and flapping tremors appeared. Blood tests revealed hyperammonemia, and the patient was diagnosed with impaired consciousness due to hyperammonemia, which was inferred to be caused by 5-fluorouracil(5-FU). Intravenous infusion and branched-chain amino acids were administered, and the patient recovered. The underlying disease of renal dysfunction, constipation, and dehydration due to chemotherapy might have induced the hyperammonemia. It is important to note that hyperammonemia can lead to a disturbance of consciousness during chemotherapy including 5-FU.