Intraoperative fluorescence angiography and risk factors of anastomotic leakage in mini-invasive low rectal resections.

BACKGROUND: One of the prerequisites for proper healing of the anastomosis after a colorectal resection is adequate blood supply to the connected intestinal segments. It has been proposed that adequate visualization of the blood flow using indocyanine green (ICG) could lead to the reduction in the incidence of anastomotic leakage (AL). The aim of this study was to assess the effectiveness of intraoperative fluorescence angiography (FA) in decreasing the incidence of AL after minimally invasive low anterior resection (LAR) with total mesorectal excision (TME) in rectal cancer patients and to determine predictors of anastomotic leak. METHODS: From August 2015 to January 2019, data from 100 patients who underwent mini-invasive TME for rectal cancer using FA with indocyanine green (ICG) were prospectively collected and analyzed. They were compared with retrospectively analyzed data from a historical control group operated by one team of surgeons before the introduction of FA from November 2012 to August 2015 (100 patients). All patients from both groups were operated sequentially in one oncological center in Nový Jicín. RESULTS: The incidence of AL was significantly lower in the ICG group (19% vs. 9%, p = 0.042, χ2 test). In fifteen patients in the ICG group (15%), the resection line was moved due to insufficient perfusion. Using Pearson's χ2 test, diabetes (p = 0.036) and application of a transanal drain (NoCoil) (p = 0.032) were identified as other risk factors (RFs) for AL. CONCLUSION: The use of ICG to visualize tissue perfusion in low rectal resections for cancer can lead to a reduction of AL.

Urogenital dysfunction in patients after miniinvasive restorative low anterior resection with total mesorectal excision.

Introduction: Over the last decades outcomes for rectal cancer surgery have improved, with increasing survival rates. Nevertheless, functional disorders are still frequent. Aim: To evaluate sexual and urinary outcomes of miniinvasive total mesorectal excision (TME). Material and methods: Between March 2016 and June 2018 patients with rectal cancer who underwent miniinvasive TME with a sphincter-saving procedure were enrolled. The questionnaires were completed before therapy, and 6, 12, and 24 months after stoma closure. We used the Female Sexual Function Index (FSFI), the International Prostate Symptom Score (IPSS) and the International Index of Erectile Function questionnaire (IIEF). Results: Ninety-eight patients completed the questionnaires. Only patients who underwent laparoscopic (39) or robotic TME (27) were enrolled. The characteristics and surgical outcomes did not differ significantly between these groups. The IPSS between the groups was comparable before and after the operation with no significant difference, increased at 6 months and then decreased consecutively. In comparison with baseline, IPSS was significantly lower in the laparoscopic and robotic groups at 6 months and was comparable to baseline at 24 months in both groups. Oppositely, the IIEF was significantly lower at 6 months after ileostomy closure in the robotic group (p < 0.05), but not in the laparoscopic group (p = 0.59) and both returned to baseline at 24 months. FSFI was significantly lower in the laparoscopic group (p = 0.017) 6 months after surgery and returned to baseline at 24 months in both groups. Conclusions: Laparoscopic and robotic TME showed similar functional results 2 years after stoma resection.

Tumor microRNAs Identified by Small RNA Sequencing as Potential Response Predictors in Locally Advanced Rectal Cancer Patients Treated With Neoadjuvant Chemoradiotherapy.

BACKGROUND/AIM: Rectal cancer accounts for approximately one-third of all colorectal cancers. Currently, the standard treatment for locally advanced rectal cancer (LARC) is neoadjuvant chemoradiotherapy (CRT) with capecitabine or 5-fluorouracil followed by curative surgery. Unfortunately, only 20% of patients with LARC present complete pathological response after CRT, whereas in 20-40% cases the response is poor or absent. The aim of our study was to evaluate whether microRNAs (miRNAs) in tumor biopsy specimen have the potential to predict therapeutic response in LARC patients. PATIENTS AND METHODS: In total 87 LARC patients treated by CRT were enrolled in our prospective study. To identify predictive miRNAs, we used small RNA sequencing in 40 tumor biopsy samples of LARC patients (20 responders, 20 non-responders) and qPCR validation of selected miRNA candidates. RESULTS: In the discovery phase of the study, we identified 69 miRNAs to have significantly different expression between the group of responders (TRG 1,2) and a group of non-responders (TRG 4,5) to neoadjuvant CRT. Among these miRNAs, 48 showed a lower expression and 21 showed higher expression in tumor tissues from poorly responding LARC patients. Five miRNAs were selected for validation, but only miR-487a-3p was confirmed to have a significantly higher expression in the tumor biopsy specimens of non-responders to neoadjuvant CRT (p<0.0006, AUC=0.766). Gene Ontology (GO) clustering and pathway enrichment analysis of the miR-487a-3p mRNA targets, revealed potential mechanisms behind miR-487a-3p roles in chemoradioresistance (e.g. TGF-beta signaling pathway, protein kinase activity, double-stranded DNA binding, or microRNAs in cancer). CONCLUSION: By combination of miRNA expression profiling and integrative computational biology we identified miR-487a-3p as a potential predictive biomarker of CRT response in LARC patients.