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.

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.

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.

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.

[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.

IRIS U kit usefulness in transanal total mesorectal excision for lower rectal cancer to avoid urethral injury.

Transanal total mesorectal excision (taTME) has improved the laparoscopic dissection for rectal cancer in the narrow pelvis. Although taTME has more clinical benefits than laparoscopic surgery, such as a better view of the distal rectum and direct determination of distal resection margin, an intraoperative urethral injury could occur in excision ta-TME. This study aimed to determine the feasibility and efficacy of the ta-TME with IRIS U kit surgery. This retrospective study enrolled 10 rectal cancer patients who underwent a taTME with an IRIS U kit. The study endpoints were the safety of access (intra- or postoperative morbidity). The detectability of the IRIS U kit catheter was investigated by using a laparoscope-ICG fluorescence camera system. Their mean age was 71.4±6.4 (58-78) years; 80 were men, and 2 were women. The mean operative time was 534.6 ± 94.5 min. The coloanal anastomosis was performed in 80%, and 20% underwent abdominal peritoneal resection. Two patients encountered postoperative complications graded as Clavien-Dindo grade 2. The transanal approach with IRIS U kit assistance is feasible, safe for patients with lower rectal cancer, and may prevent intraoperative urethral injury.

Turnbull-Cutait pull-through coloanal anastomosis versus standard coloanal anastomosis plus diverting ileostomy for low anterior resection: a meta-analysis and systematic review.

PURPOSE: Coloanal anastomosis with loop diverting ileostomy (CAA) is an option for low anterior resection of the rectum, and Turnbull-Cutait coloanal anastomosis (TCA) regained popularity in the effort to offer patients a reconstructive option. In this context, we aimed to compare both techniques. METHODS: PubMed, Cochrane, and Scopus were searched for studies published until January 2024. Odds ratios (RRs) with 95% confidence intervals (CIs) were pooled with a random-effects model. Statistical significance was defined as p < 0.05. Heterogeneity was assessed using the Cochran Q test and I2 statistics, with p-values inferior to 0.10 and I2 >25% considered significant. Statistical analysis was conducted in RStudio version 4.1.2 (R Foundation for Statistical Computing). Registered number CRD42024509963. RESULTS: One randomized controlled trial and nine observational studies were included, comprising 1,743 patients, of whom 899 (51.5%) were submitted to TCA and 844 (48.5%) to CAA. Most patients had rectal cancer (52.2%), followed by megacolon secondary to Chagas disease (32.5%). TCA was associated with increased colon ischemia (OR 3.54; 95% CI 1.13 to 11.14; p < 0.031; I2 = 0%). There were no differences in postoperative complications classified as Clavien-Dindo ≥ IIIb, anastomotic leak, pelvic abscess, intestinal obstruction, bleeding, permanent stoma, or anastomotic stricture. In subgroup analysis of patients with cancer, TCA was associated with a reduction in anastomotic leak (OR 0.55; 95% CI 0.31 to 0.97 p = 0.04; I2 = 34%). CONCLUSION: TCA was associated with a decrease in anastomotic leak rate in subgroups analysis of patients with cancer.

Role of body mass index in anastomotic leakage after curative treatment for rectal cancer.

BACKGROUND: Anastomotic leakage (AL) represents a severe complication after rectal surgery, leading to significant morbidity, mortality, and increased healthcare costs. Despite improvements in surgical methods and perioperative care, the challenge of AL persists. OBJECTIVES: Explore the impact of body mass index (BMI) on the risk of AL following curative treatment for rectal cancer, providing insight into its predictive value. DESIGN: Retrospective review. SETTINGS: Data were collected from a single tertiary center, emphasizing the specialized postoperative outcomes in a high-care setting. PATIENTS AND METHODS: The study population was comprised patients who underwent sphincter-saving surgery combined with neoadjuvant chemoradiation for rectal cancer from 2001 to 2011. Patients with anastomotic stenosis were excluded. MAIN OUTCOME MEASURES: The primary outcome investigated was the occurrence of AL post-surgery. Secondary outcomes included the assessment of local cancer recurrence rates within the AL group. SAMPLE SIZE: 224; 13 excluded. RESULTS: Of 237 patients who underwent surgery, 13 with anastomotic stenosis were excluded from this study. Of the remaining 224, 15 individuals (6.3%) developed AL. A potential association between higher BMI and increased AL risk was identified. Additionally, the study noted a higher incidence of local rectal cancer recurrence in the group that developed leakage. CONCLUSION: The findings suggest BMI as a significant predictive factor for AL after curative rectal cancer treatment. This emphasizes the need for heightened awareness and possible preoperative counseling for obese patients regarding their increased risk of postoperative leakage. LIMITATIONS: The study was retrospective with all the inherit biases of such studies. The sample size was small and this may have introduced a type 2 statistical error.

Anastomotic leakage following rectal cancer laparoscopic surgery: can a transanal drainage tube be an alternative to diverting stoma?

OBJECTIVE: Anastomosis leakage in laparoscopic surgery for rectal cancer is still a serious problem affecting the patient's treatment outcome. This study aimed to evaluate the role of a transanal drainage tube compared with a diverting stoma in reducing the rate of anastomosis leakage and limiting surgical complications. PATIENTS AND METHODS: A retrospective study was conducted on 196 rectal cancer patients undergoing laparoscopic low anterior resection from July 2018 to October 2022 at 108 Central Military Hospital. The transanal drainage tube was placed in 133 patients (group A), and diverting stoma was performed in 63 patients (group B). RESULTS: There was no difference between the two groups regarding age, sex, comorbidities, distance from the tumor to the anal verge, and preoperative stage. The amount of blood loss, the method of performing the anastomosis, and the distance from the anastomosis to the anal verge did not differ between the two groups. However, the surgical time was longer in the group with diverting stoma (138.3 ± 25.1 minutes vs. 127.6 ± 31 minutes, p = 0.018). The rate of anastomosis was not significantly different between groups A and B (8.3% in group A and 7.9% in group B, p = 0.936). The proportion of patients with anastomosis requiring reoperation in group A was higher than in group B. However, the difference was not statistically significant (8/11 patients in group A and 2/5 patients in group B, p = 0.29). CONCLUSIONS: Placing a transanal drainage tube in laparoscopic surgery for rectal cancer to reduce the rate of anastomosis can be considered an alternative method for diverting stoma with complications related to the stoma.

Solitary fibrous tumor within the mesorectum: literature review based on a case report of resection by transanal minimally invasive surgery (TAMIS).

PURPOSE: Solitary fibrous tumors (SFT) are a rare entity of in majority benign neoplasms. Nevertheless, up to 20% of cases show a malignant tendency with local infiltration or metastasis. Commonly arising in the thoracic cavity, only few cases of SFT of the mesorectal tissue have been reported in the literature. Complete surgical resection, classically by posterior approach, is the treatment of choice. The purpose of this review is to demonstrate the safety and suitability of transanal minimally invasive surgery (TAMIS) as a surgical approach for the resection of benign pararectal solid tumors. METHODS: We report the case of a 52-year-old man who was diagnosed incidentally with SFT of the distal mesorectum. Resection by TAMIS was performed. Based on this case, we describe the steps and potential benefits of this procedure and provide a comprehensive review of the literature. RESULTS: Histopathology confirms the completely resected SFT. After uneventful postoperative course and discharge on day four, follow-up was recommended by a multidisciplinary board by clinical examination and MRI, which showed a well-healed scar and no recurrence up to 3 years after resection. CONCLUSION: SFT of the mesorectum is a very rare entity. To our knowledge, this is the first report on a TAMIS resection for SFT, demonstrated as a safe approach for complete resection of benign pararectal solid tumors.

MRI-based radiomics feature combined with tumor markers to predict TN staging of rectal cancer.

The aim of this study is to evaluate the predictive ability of MRI-based radiomics combined with tumor markers for TN staging in patients with rectal cancer and to develop a prediction model for TN staging. A total of 190 patients with rectal adenocarcinoma who underwent total mesorectal excision at the First Affiliated Hospital of the Air Force Medical University between January 2016 and December 2020 were included in the study. An additional 54 patients from a prospective validation cohort were included between August 2022 and August 2023. Preoperative tumor markers and MRI imaging data were collected from all enrolled patients. The 190 patients were divided into a training cohort (n = 133) and a validation cohort (n = 57). Radiomics features were extracted by outlining the region of interest (ROI) on T2WI sequence images. Feature selection and radiomics score (Rad-score) construction were performed using least absolute shrinkage and selection operator regression analysis (LASSO). The postoperative pathology TNM stage was used to differentiate locally advanced rectal cancer (T3/4 or N1/2) from locally early rectal cancer (T1/2, N0). Logistic regression was used to construct separate prediction models for T stage and N stage. The models' predictive performance was evaluated using DCA curves and calibration curves. The T staging model showed that Rad-score, based on 8 radiomics features, was an independent predictor of T staging. When combined with CEA, tumor diameter, mesoretal fascia (MRF), and extramural venous invasion (EMVI), it effectively differentiated between T1/2 and T3/4 stage rectal cancers in the training cohort (AUC 0.87 [95% CI: 0.81-0.93]). The N-staging model found that Rad-score, based on 10 radiomics features, was an independent predictor of N-staging. When combined with CA19.9, degree of differentiation, and EMVI, it effectively differentiated between N0 and N1/2 stage rectal cancers. The training cohort had an AUC of 0.84 (95% CI: 0.77-0.91). The calibration curves demonstrated good precision between the predicted and actual results. The DCA curves indicated that both sets of predictive models could provide net clinical benefits for diagnosis. MRI-based radiomics features are independent predictors of T staging and N staging. When combined with tumor markers, they have good predictive efficacy for TN staging of rectal cancer.