A Novel Radiometry‐Guided Ablation Catheter to Reliably Treat Barrett's Esophagus

摘要

ABSTRACT In the fight to eradicate esophageal cancer, Symple Surgical aims to develop a low-cost versatile ablation system for Barrett's esophagus (BE). BE is a serious complication of gastro-esophageal reflux disease (GERD) which affects ~40% of the US population. In more than 1.6% of people, chronic exposure to acid reflux induces BE, an esophageal epithelium abnormality that can develop into lethal esophageal adenocarcinoma (EAC). Associated with obesity, as GERD and BE, EAC is increasing in incidence more rapidly than any cancer in recent years. Current endoscopic monitoring can detect precancerous BE, which is treated usually with radiofrequency ablation (RFA), available in major hospitals. However, RFA requires multiple yearly procedures with a variety of expensive target-specific applicators. More importantly, RFA treatments ablate mostly the surface epithelium, often leaving potentially precancerous cells intact deeper in the mucosal layer. Considering the rise of deadly esophageal cancer, overcoming current overall cost and procedural challenges is thus an urgent clinical need. We thus propose to integrate reliable and versatile heating mechanism with real-time accurate thermal feedback into a novel low-cost ablation device. Our DirectAblate GRIZZLY™ Microwave Ablation Catheter technology uses a dual–purpose microwave antenna with unique advantages: i) dependable ablation zone targeting the complete mucosa; ii) real-time dosimetry and guidance by passively collecting thermal radiation from multiple sensing volumes. The immediate goal is to implement radiometric sensing in our BE microwave ablation catheter and test the system in realistic phantoms, in ex-vivo tissues and in a swine in-vivo model. The long-term objective is to significantly reduce EAC incidence by improving BE ablation reliability and accuracy with precise abnormal cell targeting and real-time thermal dosimetry. The rationale for our approach is that low-cost cutting-edge mobile communication technologies can be used for affordable microwave ablation systems with radiometric feedback. Our underlying hypothesis is that by combining innovative microwave heating and thermal sensing technologies into a single disposable catheter, we can optimally and affordably ablate BE precancerous lesions. To prove our hypothesis, we propose these specific aims: 1) Integrate multiband radiometric sensing into a versatile ablation catheter for continuous accurate control during BE ablation; 2) Test the ability to accurately feedback microwave heating in realistic phantoms, ex-vivo pig esophageal tissue and in-vivo swine. Specific milestones to prove success are: 1) Optimized integration of radiometric hardware in an endoscopic microwave ablation catheter; 2) Algorithm to reconstruct temperature at multiple depths from esophageal surface; 3) Validation of reliable heating in realistic BE phantom models for several clinical scenarios; 4) Initial assessment of ablation quality in ex-vivo and in-vivo pig esophagi. The expected outcome is a new BE ablation catheter with controllable heating pattern and real-time thermal dosimetry. We anticipate that GRIZZLY™ system will be widely adopted also in low- resource settings to remove reliably precancerous BE lesions, ultimately reducing esophageal cancer deaths.