Anastomotic leakage after cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) for colorectal cancer.

BACKGROUND: Anastomotic leakage (AL) after colorectal surgery is well-researched, yet the effect of Hyperthermic Intraperitoneal Chemotherapy (HIPEC) after Cytoreductive Surgery (CRS) is unclear. Assessment of risk factors in these patients may assist surgeons during perioperative decision making. METHODS: This was a single-center, retrospective study of patients who underwent CRS-HIPEC for colorectal peritoneal metastases. Main outcome measures were anastomotic leakage and associated morbidity. RESULTS: AL was observed in 17 of the 234 (7.3%) anastomoses in 17 of the total of 165 (10.3%) of patients. No association was observed between the number and location of anastomoses and AL, although only one in 87 small bowel anastomoses showed leakage. The only factor associated with AL was administration of bevacizumab within 60 days prior to surgery with an odds ratio (OR) of 6.13 (1.32-28.39), P = 0.03. Deviating stomata were not statistically protective of increased morbidity, although more AL occurred in the patients with colocolic and colorectal anastomoses when no concomitant deviating stoma was created. Deviation stomata were reversed in 52.6%, and no AL was observed after stoma reversal. CONCLUSION: The overall AL rate of CRS-HIPEC is comparable to colorectal surgery, and there is no cumulative risk of multiple anastomoses - especially in the case of small bowel anastomoses. Deviating stomata should be considered in patients with colocolic or colorectal anastomosis, although there is a significant chance that the stoma will not be reversed in these patients. Due to increased AL-risk surgeons should be aware of previous bevacizumab treatment, and plan the CRS-HIPEC at least 60 days after the treatment-day.

Radiofrequency versus microwave ablation for intraoperative treatment of colorectal liver metastases.

INTRODUCTION: Intraoperative radiofrequency ablation (RFA) and the newer technique of microwave ablation (MWA) can both be of additional value in parenchyma preserving surgical treatment of colorectal liver metastases (CRLM). MWA is less influenced by the heat-sink effect of surrounding vessels and can generate more heat in less time but RFA is still widely used. True comparing studies are scarce. METHODS: This single centre retrospective cohort study analyzed patients who underwent ultrasound guided intraoperative ablation as a part of the surgical treatment of CRLM between 2013 and 2018. In September 2015, MWA was substituted for RFA. Outcomes included unsuccessful ablation rates at 1-year postoperative, 30-days major complication rates, progression free survival (PFS) and overall survival (OS). Logistic regression models were used for univariable and multivariable analyses to identify predictors of unsuccessful ablation. RESULTS: Forty-one patients underwent RFA of 98 lesions (median 2) and 79 patients underwent MWA of 193 lesions (median 2). The median diameter of the ablated lesions was 9 mm for both RFA and MWA. Unsuccessful ablation was observed in 7 metastases (7.1%) after RFA and 14 metastases (7.3%) after MWA (p = 1.000). Complications requiring re-intervention were observed after 8 procedures, 2 complications in the RFA group (4.9%) versus 6 complications in the MWA group (7.6%, p = 0.714), of which 6 were liver-related. Ninety-day mortality did not occur. Ablation technique was not associated with unsuccessful ablations. CRLM size was associated with unsuccessful ablation in the per lesion analysis (p < 0.001). CONCLUSION: Intraoperative RFA and MWA were equally effective for treatment of small CRLM.

Detection of tumor-derived cell-free DNA from colorectal cancer peritoneal metastases in plasma and peritoneal fluid.

Tumor-derived cell-free DNA (cfDNA) is an emerging biomarker for guiding the personalized treatment of patients with metastatic colorectal cancer (CRC). While patients with CRC liver metastases (CRC-LM) have relatively high levels of plasma cfDNA, little is known about patients with CRC peritoneal metastases (CRC-PM). This study evaluated the presence of tumor-derived cfDNA in plasma and peritoneal fluid (i.e. ascites or peritoneal washing) in 20 patients with isolated CRC-PM and in the plasma of 100 patients with isolated CRC-LM. Among tumor tissue KRAS/BRAF mutation carriers, tumor-derived cfDNA was detected by droplet digital polymerase chain reaction (ddPCR) in plasma of 93% of CRC-LM and 20% of CRC-PM patients and in peritoneal fluid in all CRC-PM patients. Mutant allele fraction (MAF) and mutant copies per ml (MTc/ml) were lower in CRC-PM plasma than in CRC-LM plasma (median MAF = 0.28 versus 18.9%, p < 0.0001; median MTc/ml = 21 versus 1,758, p < 0.0001). Within patients with CRC-PM, higher cfDNA levels were observed in peritoneal fluid than in plasma (median MAF = 16.4 versus 0.28%, p = 0.0019; median MTc/ml = 305 versus 21, p = 0.0034). These data imply that tumor-derived cfDNA in plasma is a poor biomarker to monitor CRC-PM. Instead, cfDNA detection in peritoneal fluid may offer an alternative to guide CRC-PM treatment decisions.