A development study of drain fluid gastrografin as a biomarker of anastomotic leak.

PURPOSE: Anastomotic leakage (AL) is the anathema of colorectal surgery. Its occurrence leads to increased morbidity and mortality and a prolonged hospital stay. Much work has gone into studying various biomarkers in drain fluid to facilitate early detection of AL. This stage 2a development study aims to assess the safety and feasibility of reliably detecting the iodine in Gastrografin (GG; Bayer Australia Ltd.) in drain fluid and stool samples by dual-energy computed tomography (DECT). METHODS: This is a prospective, observational, controlled, consecutive cohort study establishing the safety and feasibility of the detection of GG in surgical drain fluid and stool as a biomarker of AL when patients with a low pelvic colorectal anastomosis undergo luminal flushing of the rectal tube with GG. RESULTS: Ten consecutive patients were allocated to the saline flush group and the following 10 to the GG flush group. Three patients in the saline flush group developed an AL. One patient in the GG flush group developed an AL. An elevation in the drain fluid GG was detected using DECT on the day of clinical deterioration. None of the patients in the control group were found to have a positive result on DECT. CONCLUSION: This study demonstrates the safety of a novel approach to the early detection of AL from extraperitoneal colorectal anastomoses. The technique requires validation in a larger cohort and a multicenter study is planned to investigate the efficacy of GG rectal tube flushes as an early biomarker of AL in low pelvic anastomoses.

Gastrografin can be detected in ex vivo biological specimens by dual-energy CT scanning.

BACKGROUND: Dual-energy CT is able to distinguish between materials based on differences in X-ray absorption at different X-ray beam energies. The strong k-edge photoelectric effect of materials with a high atomic number makes this modality ideal for identifying iodine-containing compounds. We aim to evaluate dual-energy CT for the detection of Gastrografin (GG) (diatrizoate, Bayer PLC, Reading, UK) enteric contrast medium and validate the conditions for the measurement in ex vivo samples. METHODS: Dual-energy CT acquisitions were performed to detect Gastrografin in serial dilutions of water, saline and body fluids. We also evaluated the stability of Gastrografin solutions over time at room temperature. Stool specimens were examined to validate the proposed study protocol for clinical applications. RESULTS: Concentrations as low as 0.2% of Gastrografin were reproducibly detected in vitro and ex vivo samples by DECT, with linear readings ranging from 0.2% to 25% Gastrografin. Gastrografin was shown to be stable in ex vivo biological samples, and there was no difference in detection over time. Gastrografin was detected in stool specimens when administered orally. The detection curves followed the expected saturation effect at high concentrations of iodine. CONCLUSIONS: Dual-energy CT offers a convenient, quick, reliable and reproducible method for detecting and quantifying the presence of Gastrografin in ex vivo clinical specimens. Biological solutions containing Gastrografin are stable over time. A minimum dilution level of 25% is suggested to avoid beam saturation and inaccurate results.

Simultaneous positron emission tomography and magnetic resonance imaging for the detection and characterisation of liver lesions in patients with colorectal cancer: A pictorial review.

Patients with colorectal cancer undergo frequent diagnostic imaging to stage the extent of metastatic disease and assess response to treatment. Imaging is typically via diagnostic contrast-enhanced CT or combined FDG-PET/CT. However, recent research has demonstrated promising benefits of combined FDG-PET/MRI in oncologic imaging due to the superior soft-tissue contrast of MRI. The extent of both intrahepatic and extrahepatic disease is important in establishing treatment options for colorectal cancer patients, and FDG-PET/CT and dedicated liver imaging are often both required. FDG-PET/MRI offers the advantage of a single examination which can be completed within a similar duration as dedicated liver MRI imaging. This improves patient convenience and anatomical co-registration between PET and MRI imaging and provides a potential cost benefit. The diagnostic benefits of FDG-PET/MRI include the simultaneous characterisation of focal liver lesions, exclusion of extrahepatic disease, the detection of additional hepatic metastases and extrahepatic disease, and the multi-parametric assessment of treatment response. This pictorial review highlights examples of these benefits.

A Randomized Controlled Trial to Determine the Appropriate Time to Initiate Peritoneal Dialysis after Insertion of Catheter (Timely PD Study).

BACKGROUND: The optimal time for the commencement of peritoneal dialysis (PD) after PD catheter insertion is unclear. If dialysis is started too soon after insertion, dialysate leaks and infection could occur. However, by starting PD earlier, morbidity and costs can be reduced through lesser hemodialysis requirements. This is the first randomized controlled trial to determine the safest and shortest interval to commence PD after catheter insertion. METHODS: All consecutive patients undergoing PD catheter insertion at the Royal Brisbane and Women's Hospital and Rockhampton Hospital from 1 March 2008 to 31 May 2013 who met the inclusion and exclusion criteria were invited to participate in the trial. Participants were randomized to 1 of 3 groups. Group 1 (G1) commenced PD at 1 week, group 2 (G2) at 2 weeks and group 3 (G3) at 4 weeks after PD catheter insertion. These groups were stratified by hospital and the presence of diabetes. Primary outcomes were the incidence of peritoneal fluid leaks or PD-related infection during the 4 weeks after commencement of PD. RESULTS: In total 122 participants were recruited, 39, 42, and 41 randomized to G1, G2, and G3, respectively. The primary outcome catheter leak was significantly higher in G1 (28.2%) compared with G3 (2.4%, p = 0.001) but not compared with G2 (9.5%, p = 0.044), based on intention to treat analysis. These differences were even more marked when analyzed with per protocol method: G1 had a significantly higher percentage (32.4 %) compared with G3 (3.3%, p = 0.003) but not compared with G2 (10.5%, p = 0.040). Event percentages of leak were statistically higher in G1 and occurred significantly earlier compared with other groups (p = 0.002). Amongst diabetics, technique failure was significantly higher (28.6%) in G3 compared with 0% in G1 and 7.1% in G2 (p = 0.036) and earlier in G3 at 163.2 days vs 176.8 and 175.8 (p = 0.037) for G1 and G2, respectively. CONCLUSION: Leaks were higher in participants commencing PD at 1 week after catheter insertion compared with the other 2 groups, and technique failure was higher in diabetics starting PD at 4 weeks.