Single-site access robot-assisted epicardial mapping with a snake robot: preparation and first clinical experience.

CardioARM, a highly flexible "snakelike" medical robotic system (Medrobotics, Raynham, MA), has been developed to allow physicians to view, access, and perform complex procedures intrapericardially on the beating heart through a single-access port. Transthoracic epicardial catheter mapping and ablation has emerged as a strategy to treat arrhythmias, particularly ventricular arrhythmias, originating from the epicardial surface. The aim of our investigation was to determine whether the CardioARM could be used to diagnose and treat ventricular tachycardia (VT) of epicardial origin. Animal and clinical studies of the CardioARM flexible robot were performed in hybrid surgical-electrophysiology settings. In a porcine model study, single-port pericardial access, navigation, mapping, and ablation were performed in nine animals. The device was then used in a small, single-center feasibility clinical study. Three patients, all with drug-refractory VT and multiple failed endocardial ablation attempts, underwent epicardial mapping with the flexible robot. In all nine animals, navigation, mapping, and ablation were successful without hemodynamic compromise. In the human study, all three patients demonstrated a favorable safety profile, with no major adverse events through a 30-day follow-up. Two cases achieved technical success, in which an electroanatomic map of the epicardial ventricle surface was created; in the third case, blood obscured visualization. These results, although based on a limited number of experimental animals and patients, show promise and suggest that further clinical investigation on the use of the flexible robot in patients requiring epicardial mapping of VT is warranted.

Identification and characterization of hydroxyquinone hydratase activities from Sphingobium chlorophenolicum ATCC 39723.

Hydroxyquinol, a common metabolite of aromatic compounds, is readily auto-oxidized to hydroxyquinone. Enzymatic activities that metabolized hydroxyquinone were observed from the cell extracts of Sphingobium chlorophenolicum ATCC 39723. An enzyme capable of transforming hydroxyquinone was partially purified, and its activities were characterized. The end product was confirmed to be 2,5-dihydroxyquinone by comparing UV/Vis absorption spectra, electrospray mass spectra, and gas chromatography-mass spectra of the end product and the authentic compound. We have proposed that the enzyme adds a H2O molecule to hydroxyquinone to produce 2,5-dihydroxycyclohex-2-ene-1, 4-dione, which spontaneously rearranges to 1, 2,4,5-tetrahydroxybenzene. The latter is auto-oxidized by O2 to 2,5-dihydroxyquinone. The proposed pathway was supported by the overall reaction stoichiometry. Thus, the transformation of hydroxyquinol to 2,5-dihydroxyquinone involves two auto-oxidation of quinols and one enzymatic reaction catalyzed by a hydratase. The specific enzymatic step did not require O2, further supporting the assignment as a hydratase. To our knowledge, this is the first identification of a quinone hydratase, enhancing the knowledge on microbial metabolism of hydroxyquinone and possibly leading to the development of enzymatic method for the production of 2,5-dihydroxyquinone, a widely used chemical in various industrial applications.