Diagnostic accuracy of urinary intestinal fatty acid binding protein in detecting colorectal anastomotic leakage.

BACKGROUND: Anastomotic leakage (AL) remains a severe complication following colorectal surgery, having a negative impact on both short- and long-term outcomes. Since timely detection could enable early intervention, there is a need for the development of novel and accurate, preferably, non-invasive markers. The aim of this study was to investigate whether urinary intestinal fatty acid binding protein (I-FABP) could serve as such a marker. METHODS: This prospective multicenter cross-sectional phase two diagnostic study was conducted at four centers in the Netherlands between March 2015 and November 2016. Urine samples of 15 patients with confirmed colorectal AL and 19 patients without colorectal AL on postoperative day 3 were included. Urinary I-FABP levels were determined using enzyme-linked immunosorbent assays and adjusted for urinary creatinine to compensate for renal dysfunction. RESULTS: Urinary I-FABP levels were significantly elevated in patients with confirmed AL compared to patients without AL on postoperative day 3 (median: 2.570 ng/ml vs 0.809 ng/ml, p = 0.006). The area under the receiver operating characteristics curve (AUROC) was 0.775, yielding a sensitivity of 80% and specificity of 74% at the optimal cutoff point (> 1.589 ng/ml). This difference remained significant after calculation of I-FABP/creatinine ratios (median: 0.564 ng/µmol vs. 0.158 ng/µmol, p = 0.040), with an AUROC of 0.709, sensitivity of 60% and specificity of 90% at the optimal cutoff point (> 0.469 ng/µmol). CONCLUSIONS: Levels of urinary I-FABP and urinary I-FABP/creatinine were significantly elevated in patients with confirmed AL following colorectal surgery, suggesting their potential as a non-invasive biomarker for colorectal anastomotic leakage.

Urinary volatile organic compound markers and colorectal anastomotic leakage.

AIM: Inflammatory markers such as serum C-reactive protein (CRP) are used as routine markers to detect anastomotic leakage following colorectal surgery. However, CRP is characterized by a relatively low predictive value, emphasizing the need for the development of novel diagnostic approaches. Volatile organic compounds (VOCs) are gaseous metabolic products deriving from all conceivable bodily excrements and reflect (alterations in) the patient's physical status. Therefore, VOCs are increasingly considered as potential non-invasive diagnostic biomarkers. The aim of this study was to assess the diagnostic accuracy of urinary VOCs for colorectal anastomotic leakage. METHODS: In this explorative multicentre study, urinary VOC profiles of 22 patients with confirmed anastomotic leakage and 27 uneventful control patients following colorectal surgery were analysed by field asymmetric ion mobility spectrometry (FAIMS). RESULTS: Urinary VOCs of patients with anastomotic leakage could be distinguished from those of control patients with high accuracy: area under the receiver operating characteristics curve 0.91 (95% CI 0.81-1.00, P < 0.001), sensitivity 86% and specificity 93%. Serum CRP was significantly increased in patients with a confirmed anastomotic leak but with lower diagnostic accuracy compared to VOC analysis (area under the receiver operating characteristics curve 0.82, 95% CI 0.68-0.95, P < 0.001). Combining VOCs and CRP did not result in a significant improvement of the diagnostic performance compared to VOCs alone. CONCLUSION: Analysis by FAIMS allowed for discrimination between urinary VOC profiles of patients with a confirmed anastomotic leak and control patients following colorectal surgery. A superior accuracy compared to CRP and apparently high specificity was observed, underlining the potential as a non-invasive biomarker for the detection of colorectal anastomotic leakage.

Biliary tract visualization using near-infrared imaging with indocyanine green during laparoscopic cholecystectomy: results of a systematic review.

BACKGROUND: Near-infrared imaging with indocyanine green (ICG) has been extensively investigated during laparoscopic cholecystectomy (LC). However, methods vary between studies, especially regarding patient selection, dosage and timing. The aim of this systematic review was to evaluate the potential of the near-infrared imaging technique with ICG to identify biliary structures during LC. METHODS: A comprehensive systematic literature search was performed. Prospective trials examining the use of ICG during LC were included. Primary outcome was biliary tract visualization. Risk of bias was assessed using ROBINS-I. Secondly, a meta-analysis was performed comparing ICG to intraoperative cholangiography (IOC) for identification of biliary structures. GRADE was used to assess the quality of the evidence. RESULTS: Nineteen studies were included. Based upon the pooled data from 13 studies, cystic duct (Lusch et al. in J Endourol 28:261-266, 2014) visualization was 86.5% (95% CI 71.2-96.6%) prior to dissection of Calot's triangle with a 2.5-mg dosage of ICG and 96.5% (95% CI 93.9-98.4%) after dissection. The results were not appreciably different when the dosage was based upon bodyweight. There is moderate quality evidence that the CD is more frequently visualized using ICG than IOC (RR 1.16; 95% CI 1.00-1.35); however, this difference was not statistically significant. CONCLUSION: This systematic review provides equal results for biliary tract visualization with near-infrared imaging with ICG during LC compared to IOC. Near-infrared imaging with ICG has the potential to replace IOC for biliary mapping. However, methods of near-infrared imaging with ICG vary. Future research is necessary for optimization and standardization of the near-infrared ICG technique.

Near infrared fluorescence lymphatic laparoscopy of the colon and mesocolon.

During surgery, a surgeon relies on the vision of his eyes and the touch of his hands. While laparoscopic surgery for colon cancer has proven to be safe and effective, it still remains a technically difficult procedure. Although it is associated with reduced haptic feedback, by enforcing the power of visual guidance, the loss of this feedback can be (partly) compensated for. Here we describe how the use of near-infrared dyes and fluorescence laparoscopy could help improve tumour staging and therefore lead to better selection of patients for postoperative adjuvant chemotherapy. More controversially, and analogous to melanoma and breast cancer surgery with sentinel node biopsy, we speculate that local resection with SLN harvesting in early colon cancer might change the therapeutic and surgical strategy in colon cancer.