BACKGROUND: Transmyocardial laser revascularization using different lasers is being tested in the treatment of refractory angina. We conducted comparative analysis of the acute and chronic myocardial effects of these different lasers. METHODS: Transmyocardial channels were made in normal dog hearts with either a holmium:yttrium-aluminum garnet or a CO2 laser. Channels were examined histologically 6 to 24 hours, 2 to 3 weeks, and 6 weeks after creation. RESULTS: Regardless of the laser source, the channels were occluded by thrombus within 6 to 24 hours. Subsequently, organization and neovascularization of the channel region occurred. Thermoacoustic damage was initially greater with the holmium:yttrium-aluminum garnet laser, but the channel appearances were indistinguishable from those made with the CO2 laser by 6 weeks. CONCLUSIONS: Histologically, the myocardial effects of the CO2 and holmium:yttrium-aluminum garnet lasers are similar and differ predominantly in the amount of acute thermoacoustic injury. Channels are rapidly occluded by thrombus and are replaced by neovascularized collagen. This suggests that the physiologic effects of these two lasers may be similar and that mechanisms other than blood flow through chronic patent channels should be considered as contributing to the clinical benefits observed with this procedure.
BACKGROUND: Transmyocardial laser revascularization using different lasers is being tested in the treatment of refractory angina. We conducted comparative analysis of the acute and chronic myocardial effects of these different lasers. METHODS: Transmyocardial channels were made in normal dog hearts with either a holmium:yttrium-aluminum garnet or a CO2 laser. Channels were examined histologically 6 to 24 hours, 2 to 3 weeks, and 6 weeks after creation. RESULTS: Regardless of the laser source, the channels were occluded by thrombus within 6 to 24 hours. Subsequently, organization and neovascularization of the channel region occurred. Thermoacoustic damage was initially greater with the holmium:yttrium-aluminum garnet laser, but the channel appearances were indistinguishable from those made with the CO2 laser by 6 weeks. CONCLUSIONS: Histologically, the myocardial effects of the CO2 and holmium:yttrium-aluminum garnet lasers are similar and differ predominantly in the amount of acute thermoacoustic injury. Channels are rapidly occluded by thrombus and are replaced by neovascularized collagen. This suggests that the physiologic effects of these two lasers may be similar and that mechanisms other than blood flow through chronic patent channels should be considered as contributing to the clinical benefits observed with this procedure.
Authors: Miroslaw A Dziuk; Ana Canizales; Nidhal Ali; Hany El-Deeb; Keith E Britton; Duncan S Dymond; Stephen J Edmondson Journal: Int J Cardiovasc Imaging Date: 2005-08 Impact factor: 2.357
Authors: Soren K Estvold; Frederico Mordini; Yifu Zhou; Zu X Yu; Vandana Sachdev; Andrew Arai; Keith A Horvath Journal: Lasers Surg Med Date: 2010-12 Impact factor: 4.025
Authors: Jessika Iwanski; Shannon M Knapp; Ryan Avery; Isabel Oliva; Raymond K Wong; Raymond B Runyan; Zain Khalpey Journal: J Cardiothorac Surg Date: 2017-05-19 Impact factor: 1.637
Authors: Jessika Iwanski; Raymond K Wong; Douglas F Larson; Alice S Ferng; Raymond B Runyan; Steven Goldstein; Zain Khalpey Journal: Springerplus Date: 2016-06-16