Abstract: A minimally invasive coronary anastomosis procedure includes providing an incision in an intercostal space between two ribs of a patient, the incision providing access to a selected anastomosis site on a blocked coronary artery. A spreader device is inserted between the two ribs, the spreader device spreading the two ribs apart to sufficiently widen the incision for the procedure to be performed through the incision. An internal mammary artery is dissected from the thoracic wall, and the heart is pharmaceutically treated to substantially reduce its heartbeat. The blocked coronary artery is clamped at two spaced-apart positions at the selected anastomosis site. The blocked coronary artery is incised, and the dissected internal mammary artery is sutured to the incision at the anastomosis site.

Abstract: A hydrostatic coupling with a housing fastened on a first coupling shaft. Several gears which operate as geared pumps are contained in recesses of the housing and are arranged in a planetary manner about a gear fastened on a second coupling shaft as a sun gear. The sun gear fastened on the second coupling shaft forms a geared pump with each of the planetary gears driven by the sun gear. The sun gear as well as the planetary gears on the one hand engage against the smooth inner housing wall, and on the other hand engage against a sealing plate which is axially externally adjustable against spring force. This sealing plate, according to axial adjustment, entirely or partially closes the circulation passages of the geared pumps.