Retrospective Cohort Study
Copyright ©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Surg. Jul 27, 2019; 11(7): 308-321
Published online Jul 27, 2019. doi: 10.4240/wjgs.v11.i7.308
Vascular calcification does not predict anastomotic leak or conduit necrosis following oesophagectomy
Benjamin J Jefferies, Emily Evans, James Bundred, James Hodson, John L Whiting, Colm Forde, Ewen A Griffiths
Benjamin J Jefferies, James Bundred, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, United Kingdom
Emily Evans, Colm Forde, Department of Radiology, University Hospitals Birmingham NHS Foundation Trust, Birmingham B15 2WB, United Kingdom
James Hodson, Institute of Translational Medicine, University Hospitals Birmingham NHS Foundation Trust, Birmingham B15 2TT, United Kingdom
John L Whiting, Ewen A Griffiths, Department of Upper Gastrointestinal Surgery, University Hospitals Birmingham NHS Foundation Trust, Birmingham B15 2TH, United Kingdom
Ewen A Griffiths, Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham B15 2TT, United Kingdom
Author contributions: Jefferies BJ, Forde C, Whiting JL and Griffiths EA designed the research; Jefferies BJ, Bundred J and Evans E performed the research; Jefferies BJ and Hodson J analysed the data; Jefferies BJ and Griffiths EA wrote the manuscript; all authors critically reviewed and approved the manuscript.
Institutional review board statement: The study was registered No. CARMS-15096 with University Hospitals Birmingham Clinical Audit Registration and Management System (CARMS), who granted ethical approval.
Informed consent statement: Local ethical review was obtained and confirmed that no consent was needed due to the non-interventional nature of the study.
Conflict-of-interest statement: The authors declare no conflicts of interest.
STROBE statement: The authors have read the STROBE checklist, and the manuscript was prepared and revised according to the STOBE statement checklist.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Ewen A Griffiths, MD FRCS, Consultant Surgeon, Department of Upper Gastrointestinal Surgery, University Hospitals Birmingham NHS Foundation Trust, Mindelsohn Way, Birmingham B15 2TH, United Kingdom. ewen.griffiths@uhb.nhs.uk
Telephone: +44-12-13715883 Fax: +44-12-1371 5896
Received: May 2, 2019
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
ARTICLE HIGHLIGHTS
Research background

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.

Research motivation

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.

Research objectives

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.

Research methods

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.

Research results

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.

Research conclusions

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.

Research perspectives

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.