A Novel Microwave Catheter Can Perform Noncontact Circumferential Endocardial Ablation in a Model of Pulmonary Vein Isolation

Abstract

A microwave catheter can be designed to produce a circumferential thermal lesion on noncontact ablation and may have possible applications for pulmonary vein isolation.

The impact of frequency on the performance of microwave ablation

“…Microwave ablation (MWA) is being investigated for a variety of medical therapies including treatment of endometrial bleeding [1], uterine myomas [2], atrial fibrillation [3], and cancerous tumours in the liver [4][5][6], kidneys [7], pancreas [8], lungs [9], and breast [10]. A MWA probe typically consists of a coaxial cable feeding an interstitial antenna that radiates electromagnetic (EM) power into the tissue surrounding the antenna.…”

“…Most studies of MWA have been conducted at 915 MHz [8,[11][12][13][14] and 2.45 GHz [2,3,6,7,9,10,[15][16][17][18][19][20]. Similarly, most if not all commercial MWA systems to date operate at one of these two frequencies.…”

Sensitivity analysis of critical parameters affecting the efficacy of microwave ablation using Taguchi method

“…The use of microwaves for thermal cancer treatment was first reported in 1980s for the treatment of liver tumors . Subsequently, MWA method has been employed for ablating variety of tumors in the bone, kidney, lung, pancreas, and breast, as well as for non‐oncologic applications, as follows, treatment of endometrial bleeding, uterine myomas, and atrial fibrillation . The basic MWA system typically consists of the microwave power generator, an interstitial antenna applicator, and a cooling system.…”

“…4 Subsequently, MWA method has been employed for ablating variety of tumors in the bone, 5,6 kidney, 7,8 lung, [9][10][11] pancreas, 12 and breast, 13 as well as for non-oncologic applications, as follows, treatment of endometrial bleeding, 14 uterine myomas, 15 and atrial fibrillation. 16 The basic MWA system typically consists of the microwave power generator, an interstitial antenna applicator, and a cooling system. Most of the studies available in the literature on MWA have been conducted utilizing electromagnetic wave frequencies of 915 MHz or 2.45 GHz to produce frictional tissue heating by the process known as dielectric hysteresis.…”

Transcatheter non-contact microwave ablation may enable circumferential renal artery denervation while sparing the vessel intima and media

“…Microwave energy has properties that are highly suited for RDN. Microwave heating is dielectric and not contact-dependent, making it possible to heat deeper tissues directly while simultaneously avoiding high temperatures in the renal artery wall, which is cooled by adjacent blood flow 13,14 . We hypothesised that a microwave catheter centred in a renal artery could create a thermal lesion that is: (i) circumferential around the renal artery, and (ii) deeper than radiofrequency ablation with the potential to encompass the majority of renal nerves; while (iii) avoiding thermal injury to a subendothelial zone thick enough to spare the renal artery intima and media.…”