Randomized comparison of ultrasonic aspiration versus conventional electrocautery for dissection of the human internal thoracic artery

AbstractThe most common technique currently employed to harvest the internal thoracic artery for coronary artery bypass grafting is conventional electrocautery. This study compared an alternative method, electrocautery with an ultrasonic aspirator, for harvesting the internal thoracic artery. Patients were randomly assigned to one of six experimental groups (conventional electrocautery, ultrasonic aspirator at settings of 60%, 80%, and 100% power output, and ultrasonic aspirator in 100% CAVI-Pulse modes 1 and 3). Ring segments of internal thoracic artery were studied in an organ bath. Contraction responses were elicited with 123 mmol/L potassium physiologic salt solution, KPSS, KPSS solution containing noradrenaline, and a cumulative noradrenaline dose-contraction curve. Relaxation studies were performed with the vasodilators acetylcholine, bradykinin, and sodium nitroprusside. Forty percent of the electrocauterized vessels were traumatized or damaged and failed to respond to contractile stimuli, whereas only 10% of the vessels in ultrasonic aspirator groups 60%, 80%, and 100% failed to respond. All vessels in the group harvested by ultrasonic aspirator in 100% CAVI-Pulse mode 1 responded, whereas 20% of the vessels in the group harvested by ultrasonic aspirator in 100% CAVI-Pulse mode 3 failed to respond. All settings of electrocautery with an ultrasonic aspirator produced a greater contractile response to KPSS and noradrenaline. Acetylcholine and sodium nitroprusside produced similar relaxations in all groups, but the bradykinin responses were significantly improved in all groups undergoing 100% electrocautery with an ultrasonic aspirator. These results suggest that 100% electrocautery with an ultrasonic aspirator, particularly in 100% CAVI-Pulse mode 1, resulted in less damage and trauma than conventional electrocautery during harvesting of the internal thoracic artery. (J T HORAC CARDIOVASC SURG 1996;111:1194-9

Uso de câmara úmida em enxertia hipocotiledonar de maracujazeiro-amarelo sobre três porta-enxertos Use of humid chamber in hypocotyledonary grafting of yellow passion fruit on three rootstocks

Com o objetivo de avaliar o desenvolvimento e a sobrevivência de plantas de maracujazeiro-amarelo (Passiflora edulis Sims) enxertadas sobre três porta-enxertos com uso de câmara úmida, instalou-se este experimento em um viveiro de mudas no município de Adamantina - SP, no período de dezembro de 2005 a abril de 2006. O delineamento foi em blocos ao acaso, em esquema fatorial 3 x 2, com quatro repetições. Os fatores avaliados foram três porta-enxertos (Passiflora edulis, P. alata e P. gibertii) em dois ambientes (com e sem câmara úmida). Foi utilizada a enxertia hipocotiledonar pelo método de garfagem tipo fenda cheia. Avaliaram-se a altura das plantas, o diâmetro do caule do porta-enxerto e do enxerto, o número de folhas, o comprimento do entrenó, a porcentagem de sobrevivência das plantas e a fitomassa seca da parte aérea e das raízes. Observou-se que o método de enxertia utilizado foi bem-sucedido para as três espécies de porta-enxertos estudadas. P. gibertii e P. edulis proporcionaram melhores resultados como porta-enxertos. O porta-enxerto P. alata proporcionou menor altura de planta, menor diâmetro do enxerto e do porta-enxerto e menor índice de sobrevivência. O uso da câmara úmida não favoreceu nenhuma das variáveis estudadas.<br>The experiment was installed in Adamantina, SP, Brazil, from December 2005 to April 2006, aiming to evaluate yellow passion fruit plants (Passiflora edulis Sims) development and survival, when they were grafted on three rootstocks during the nursery phase. The experimental design was in randomized blocks in a factorial scheme 3 x 2, with four replications. The studied factors were three rootstocks (Passiflora edulis, P. alata and P. gibertii) in two environments (with and without humid chamber). Seedlings were grafted by the cleft grafting method. The variables evaluated were: grafts height, rootstocks and grafts stem diameter, leaf number, internode length, survival percentage, aerial portion and roots fresh and dry weight. It was observed that the hypocotyledonary grafting was efficient for the three species of passion fruit. The species P. gibertii and P. edulis presented better result as rootstocks. The treatment with P. alata presented lower height plant, lower rootstock and graft diameter and lower survival percentage. The use of humid chamber did not favour any of the studied variables