Published online Jul 27, 2019. doi: 10.4240/wjgs.v11.i7.308
Peer-review started: May 9, 2019
First decision: June 12, 2019
Revised: June 17, 2019
Accepted: July 24, 2019
Article in press: June 24, 2019
Published online: July 27, 2019
Processing time: 90 Days and 8.4 Hours
Anastomotic leaks (AL) are a serious complication following oesophagectomy, resulting in a reduction in both quality and quantity of life. When severe, AL can lead to conduit necrosis (CN) and complete breakdown of the anastomosis, resulting in pneumonia, sepsis and very poor patient outcomes. The formation and continued integrity of the anastomosis and gastric conduit is reliant on adequate perfusion of the gastric tube by the gastro-epiploic arcades.
One of the factors with the ability to affect perfusion at the anastomosis is calcification of the arteries supplying the gastric conduit and remnant oesophagus. Recent evidence has inconsistently linked calcification of these arteries with AL and CN. Arterial calcification, which can be routinely measured on pre-operative computed tomography (CT) scan, could, therefore, become an important aid in both patient selection and anastomotic risk assessment.
The objectives of this study were therefore to evaluate whether an association exists between calcification of arteries supplying the gastric conduit, namely the proximal aorta, distal aorta, coeliac trunk and branches of the coeliac trunk, and AL.
Utilising routine pre-operative CT thorax, abdomen and pelvis scans, two blinded reviewers independently score vessel calcification according to the visual grading system proposed by van Rossum et al. Our prospectively maintained departmental database of patients undergoing oesophagectomy between 2006 and 2017 was examined to identify patients experiencing post-operative AL or CN. Inter-rater reliability of scoring of vessel calcification was statistically assessed using quadratic weighted kappa analyses. Univariable analyses was then performed to identify demographic and operative factors associated with AL. Subsequently, multivariable binary logistic regression models were produced to optimise the accuracy of AL prediction by artery calcification.
Of 411 patients with available data, 65 (15.8%) developed a AL post-operatively. Additionally, 4 patients had a CN not associated with AL. Rates of AL were higher in female patients (P = 0.047) and rates of CN were higher in female patients (P = 0.014), diabetic patients (P = 0.014), positive smoking history (P = 0.008) and higher ASA grade (P = 0.024). Inter-rater reliability scoring found excellent agreement between the two reviewers (absolute agreement 95.6%-99%). None of the calcification scores were associated with AL or CN on univariable or composite score analysis. Additionally, increasing calcification score was not associated with increasing severity of complications as defined by Esophagectomy Complications Consensus Group criteria.
This study found no association between vascular calcification and AL or CN. Previous literature is highly heterogenous with regards to the location of calcification assessed, published leak definitions and AL rates. At the time of writing, this is the first study to aim to identify an association between vascular calcification in the aorta and coeliac axis branches within a United Kingdom population.
This study and others will inform large prospective multi-centre studies currently being conducted, including the Oesophago-Gastric Anastomosis Audit, which aims to provide more definitive data with regards to factors associated with AL. Our results suggest that it is micro-perfusion of the gastric conduit that may be more important in anastomotic leakage that the calcification of the main abdomino-thoracic blood vessels. As such a larger, multicentre, prospective study assessing both these variables by pre-operative CT assessment of calcification of the large vessels together with intra-operative micro-perfusion of the gastric conduit by indo-cyanine green perfusion may well be the best method to definitively answer this research question.