Impact of freezing time and balloon size on the thermodynamics and isolation efficacy during pulmonary vein isolation using the second generation cryoballoon.

BACKGROUND: The differences in ablation characteristics of freezing time and balloon size using second generation cryoballoon are still unknown. METHODS AND RESULTS: Twenty-six dogs underwent pulmonary vein (PV) isolation. Balloon and tissue temperatures (left atrial-PV junction, phrenic nerve, and internal esophagus) were monitored. The ablation duration was randomized to either 3 or 4 minutes, which did not show significant differences in temperature profiles, PV isolation success rate, complications, or histological changes. Twenty dogs underwent cryoablation using 28-mm cryoballoon, 6 dogs were done using the 23-mm cryoballoon. Positioning of the 23-mm cryoballoon was more distal in the PV, which resulted in better PV occlusion. Temperature profiles showed lower temperatures in the 23-mm cryoballoon than in the 28-mm cryoballoon (inner balloon, median [range]: -51.5 [-66.0 to -31.0] versus -43.0 [-64.0 to -26.0]°C, P<0.001; balloon surface: -43.0 [-60.0 to -15.8] versus -6.5 [-46.2 to 28.9]°C, P<0.001; left atrial-PV junction: -6.7 [-20.0 to 21.4] versus 15.8 [-14.4 to 35.1]°C, P<0.001), and trended toward a higher PV isolation success rate in the 23-mm cryoballoon. Histologically, deeper extensions of ablative lesions into the PV were seen with 23-mm cryoballoon, and larger ablative lesions were seen in the left atrial antrum using 28-mm cryoballoon. CONCLUSIONS: The efficacy of 3-minute ablation was not significantly different from 4-minute ablation in dogs. The 23-mm cryoballoon had a greater cooling effect than the 28-mm cryoballoon for small PVs, but showed narrower ablative lesions in the left atrial antrum.

Spatial and time-course thermodynamics during pulmonary vein isolation using the second-generation cryoballoon in a canine in vivo model.

BACKGROUND: Thermodynamics in the left atrium-pulmonary vein (PV) junction, phrenic nerve, and esophagus during PV isolation (PVI) using the second-generation cryoballoon are not known. METHODS AND RESULTS: Twenty dogs underwent PVI using second-generation cryoballoon. Ablations were performed for ≤2 deliveries based on PVI without a bonus freeze. Inner balloon, balloon surface, and tissue temperatures were monitored during cryoablation. The tissue thermocouples were placed on the epicardial surface of the left atrium-PV junction, as well as on the phrenic nerve and within the esophagus. A total of 259 cryoballoon and 229 tissue tissue thermocouples profiles during 53 cryoablations of 40 PVs were analyzed. Acutely, PVI was achieved in 36 of 40 PVs (90%). Conductive tissue cooling spread radially from the balloon-left atrium-PV contact point. The lowest tissue temperatures were dependent on the distance of the tissue thermocouples to the balloon surface (r=0.85; P<0.001). In addition, blood flow leaks around the balloon had a warming effect on the balloon and tissue temperature profiles. Chronic isolation (mean, 48±16 days) was achieved in 27 of 36 PVs (75%). In 8 of 9 acutely isolated but with chronic reconnection PVs, the blood flow leak location was concordant with chronic reconnection gap. Although only 1 esophageal ulcerated lesion was observed, neither phrenic nerve palsy nor severe PV stenosis was seen in any dogs. CONCLUSIONS: Variance in tissue thermodynamics during cryothermal ablation depends on the distance from balloon and peri-balloon blood flow leaks. This information may be useful for successful PVI without severe complications.

Endoscopic treatments of obesity and metabolic disease: are we there yet?

Obesity and metabolic diseases represent a major problem for our society. For this reason, a number of medical, behavioral, hygienic-dietetic and surgical therapies have been used in an attempt to solve or palliate this problem. In these last years, we have seen a growing number of endoscopic therapies directly targeted to treat obesity and its complications, and its clinical usefulness is relatively unknown. The current review attempts to update what is known on the different endoscopic therapies for obesity, paying special attention to technical aspects and the existing evidence of their usefulness in clinical practice.

Tratamiento endoscópico de la obesidad y los trastornos metabólicos: ¿una realidad? / Endoscopic treatments of obesity and metabolic disease: are we there yet?

La obesidad y sus complicaciones representan un problema mayor en nuestra sociedad. Por este motivo se han empleado diversos tratamientos médicos, conductuales, higiénico dietéticos y quirúrgicos, con la intención de paliar o solventar este problema. En estos últimos años hemos visto aparecer múltiples tratamientos endoscópicos destinados al tratamiento de la obesidad y sus complicaciones, pero su utilidad real es poco conocida. La presente revisión tiene como objetivo realizar una puesta al día sobre las diferentes alternativas existentes para el tratamiento endoscópico de la obesidad, incidiendo en aspectos técnicos y en la evidencia existente en la literatura sobre su utilidad clínica (AU)

Obesity and metabolic diseases represent a major problem for our society. For this reason, a number of medical, behavioral, hygienic-dietetic and surgical therapies have been used in an attempt to solve or palliate this problem. In these last years, we have seen a growing number of endoscopic therapies directly targeted to treat obesity and its complications, and its clinical usefulness is relatively unknown. The current review attempts to update what is known on the different endoscopic therapies for obesity, paying special attention to technical aspects and the existing evidence of their usefulness in clinical practice (AU)