CT scan for early diagnosis of anastomotic leak after colorectal surgery: is rectal contrast useful?

BACKGROUND: Computed tomography (CT) scan with rectal contrast enema (RCE-CT) could increase the detection rate of anastomotic leaks (AL) in the early postoperative period following colorectal surgery, compared to CT scan without RCE. The aim of this study was to assess the benefit of RCE-CT for the early diagnosis of AL following colorectal surgery. METHODS: Patients who had a RCE-CT for suspected AL in the early postoperative period following colorectal surgery with anastomosis between January 2012 and July 2019 at the Dijon University Hospital were retrospectively included. All images were reviewed by two independent observers who were blinded to the original report. The reviewers reported for each patient whether an AL was present or not in each imaging modality (CT scan, then RCE-CT). Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were then calculated to determine the diagnostic performance of each modality. RESULTS: One hundred and thirty-nine patients were included. RCE-CT had an increased NPV compared to CT scan (82% vs 77% (p = 0.02) and 84% vs 68% (p < 0.0001) for observers 1 and 2, respectively). RCE-CT had an increased sensitivity compared to CT scan (79% vs 48% (p < 0.0001) for observer 2). RCE-CT had a significant lower false-negative rate for both observers: 18% vs 23% (p = 0.02) and 16% vs 32% (p < 0.0001). CONCLUSIONS: RCE-CT improved the detection rates of AL in the early period following colorectal surgery. RCE-CT should be recommended when a CT scan is negative and AL is still suspected.

BRAF mutation is not associated with an increased risk of recurrence in patients undergoing resection of colorectal liver metastases.

BACKGROUND: BRAF mutation is associated with a poor prognosis in patients with metastatic colorectal cancer. For patients with resectable colorectal liver metastases (CRLMs), the prognostic impact of BRAF mutation is unknown and the benefit of surgery debated. This nationwide intergroup (ACHBT, FRENCH, AGEO) study aimed to evaluate the oncological outcome of patients undergoing liver resection for BRAF-mutated CRLMs. METHODS: The study included patients who underwent resection for BRAF-mutated CRLMs in 24 centres between 2012 and 2016. A case-matched comparison was made with 183 patients who underwent resection of CRLMs with wild-type BRAF during the same interval. RESULTS: Sixty-six patients who underwent resection for BRAF-mutated CRLMs in 24 centres were compared with 183 patients with wild-type BRAF. The 1- and 3-year disease-free survival (DFS) rates were 46 and 19 per cent for the BRAF-mutated group, and 55·4 and 27·8 per cent for the group with wild-type BRAF (P = 0·430). In multivariable analysis, BRAF mutation was not associated with worse DFS (hazard ratio 1·16, 95 per cent c.i. 0·72 to 1·85; P = 0·547). The 1- and 3-year overall survival rates after surgery were 94 and 54 per cent respectively among patients with BRAF mutation, and 95·8 and 82·9 per cent in those with wild-type BRAF (P = 0·004). Median survival after disease progression was 23·0 (95 per cent c.i. 11·0 to 35·0) months among patients with mutated BRAF and 44·3 (35·9 to 52·6) months in those with wild-type BRAF (P = 0·050). Multisite disease progression was more common in the BRAF-mutated group (48 versus 29·8 per cent; P = 0·034). CONCLUSION: These results support surgical treatment for resectable BRAF-mutated CRLM, as BRAF mutation by itself does not increase the risk of relapse after resection. BRAF mutation is associated with worse survival in patients whose disease relapses after resection of CRLM, as for non-metastatic colorectal cancer.

Inflammatory markers for the early detection of post-operative infection: The same threshold for rectal and colic surgery?

INTRODUCTION: Anastomotic fistula is the most fearsome complication following colorectal surgery. Numerous studies have demonstrated the interest of postoperative CRP assay as an early diagnostic marker. Must the critical threshold for biological inflammatory markers remain the same, whether resection be colic or rectal? PATIENTS AND METHOD: This is a study based on a cohort constituted between 2011 and 2014, including 497 patients with planned colorectal resection. C-reactive protein and pro-calcitonin were measured daily from day before surgery to D4. All postoperative intra-abdominal complications were considered as an anastomotic fistula. Detection thresholds were calculated from the area under the ROC curve. RESULTS: An intra-abdominal septic complication occurred in 16.9% of the patients having undergone rectal resection vs. 9.9% of those having had colectomy (P=0.03). In the absence of complications there was no significant difference between the two groups in terms of postoperative inflammatory response as determined by either CRP or PCT assay. Following rectal resection, optimal area under the curve (AUC=0.87) corresponds to CRP on D4 for a threshold of 100mg/L: sensitivity 83.3%, NPV 95.3%. For colons with the same CRP at 100mg/L (AUC=0.71): sensitivity 63.6%, NPV 93.9%. CONCLUSION: Notwithstanding riskier surgery, the detection threshold for an anastomotic fistula following rectal surgery remains the same: CRP>100mg/L at D4.