Mass spectrometry transanal minimally invasive surgery (MS-TAMIS) to promote organ preservation in rectal cancer

James Alexander,James Kinross,Liam Poynter,Petra Paizs,Ara Darzi,Zoltan Takats,Afeez Adebesin,Eftychios Manoli,Robert Goldin,Sam Mason

doi:10.1007/s00464-019-07140-y

Abstract

BackgroundTransanal minimally invasive surgery (TAMIS) is deployed for organ preservation in early rectal cancer and significant rectal polyps. Rapid evaporative ionisation mass spectrometry (REIMS) provides biochemical tissue analysis, which could be applied intraoperatively to give real-time tissue feedback to the surgeon and decrease the risk of an involved margin. However, the accuracy and feasibility of this approach have not been established.MethodsIn this prospective observational study, patients undergoing resection of rectal adenomas or carcinomas were recruited. An electrosurgical handpiece analysed tissues ex vivo using diathermy, with the aerosol aspirated into a Xevo G2-S ToF mass spectrometer. The relative abundance of lipids underwent predictive statistical modelling and leave-one-patient-out cross-validation. The outcomes of interest were the ability of REIMS to differentiate normal, adenomatous and cancerous tissue, or any disease subtype from normal. REIMS was coupled with TAMIS for in vivo sampling, assessing the accuracy of tissue recognition and distinguishing bowel wall layers.ResultsForty-seven patients were included, yielding 266 spectra (121 normal, 109 tumour and 36 adenoma). REIMS differentiates normal, adenomatous and cancerous rectal tissues with 86.8% accuracy, and normal and adenomatous tissue with 92.4% accuracy and 91.4% accuracy when differentiating disease from normal. We have performed the first five in-man mass spectrometry augmented TAMIS (MS-TAMIS). In real time, MS-TAMIS can differentiate rectal mucosa and submucosa based on their relative abundance of triglycerides and glycerophospholipids. The ex vivo accuracy distinguishing diseased and normal tissues is maintained in vivo at 90%, with negative predictive value of 95%. The system identified a deep and lateral involved tumour margin during TAMIS.ConclusionsREIMS distinguishes rectal tissue types based on underlying lipid biology, and this can be translated in vivo by coupling it to TAMIS. There is a role for this technology in improving the efficacy of resection of early rectal cancers.

Highlights

Transanal minimally invasive surgery (TAMIS) is deployed for organ preservation in early rectal cancer and significant rectal polyps
We present an augmentation to the TAMIS platform by linking it to our previously described rapid evaporative ionisation mass spectrometry (REIMS) method, which provides real-time analysis of lipid molecules present in the diathermy plume generated during electrosurgical tissue dissection [4,5,6]
It has been demonstrated that it is feasible to augment TAMIS with Rapid evaporative ionisation mass spectrometry (REIMS) to potentially provide the surgeon with accurate and meaningful clinical data

Summary

Introduction

Transanal minimally invasive surgery (TAMIS) is deployed for organ preservation in early rectal cancer and significant rectal polyps. The outcomes of interest were the ability of REIMS to differentiate normal, adenomatous and cancerous tissue, or any disease subtype from normal. REIMS was coupled with TAMIS for in vivo sampling, assessing the accuracy of tissue recognition and distinguishing bowel wall layers. REIMS differentiates normal, adenomatous and cancerous rectal tissues with 86.8% accuracy, and normal and adenomatous tissue with 92.4% accuracy and 91.4% accuracy when differentiating disease from normal. MS-TAMIS can differentiate rectal mucosa and submucosa based on their relative abundance of triglycerides and glycerophospholipids. The ex vivo accuracy distinguishing diseased and normal tissues is maintained in vivo at 90%, with negative predictive value of 95%. Conclusions REIMS distinguishes rectal tissue types based on underlying lipid biology, and this can be translated in vivo by coupling it to TAMIS. There is a role for this technology in improving the efficacy of resection of early rectal cancers

Methods

Results

Conclusion