PubMed Health⌕ Search

Biomedical subjects

R L Fisk

Publications and source records attributed to R L Fisk.

11 recordsLinked to original sources
PubMed1978

Hypothermic coronary perfusion for myocardial protection during aortocoronary bypass.

Numerous methods have been used in an attempt to prevent myocardial injury that results from the interruption of aortic flow during cardiac operations. The authors describe a relatively simple means of inducing cardioplegia during coronary bypass surgery by coronary perfusion with cold lactated Ringer's solution through the aortic root. When the results following the employment of hypothermic coronary perfusion for intraoperative cardioplegia were compared with those obtained without its use, the procedure was found to confer a degree of intraoperative myocardial protection and appeared to lead to a decrease in intraoperative myocardial infarction, subendocardial ischemia and intraoperative mortality.

Coronary Artery Bypass↗
PubMed1978

Myocardial protection during aortic valve replacement: normothermia versus hypothermia.

The operative results in 32 patients who underwent aortic valve replacement with aortic occlusion and normothermic myocardium (group 1) were compared with 54 similar patients in whom the myocardium was protected by hypothermic coronary perfusion through the aortic root (group 2). The operative mortality and the incidence of heart failure, subendocardial ischemia and myocardial infarction were the same in the two groups. The maximal concentrations of cardiac enzymes after operation in group 2 patients were significantly lower than those in group 1. The postoperative cardiac performance was significantly different in that only 5.6% of group 2 patients required inotropic agents after operation compared with 25% of group 1 patients. The patients in group 2 were easier to defibrillate after cardiopulmonary bypass.

Adult↗
PubMed1977

Hypothermic coronary perfusion for intraoperative cardioplegia.

Hypothermic asanguineous perfusion has been used to arrest 170 hearts at the beginning of 1/2 to 2 hours of intraoperative coronary ischemia. This method of producing cardioplegia has facilitated valve replacement and coronary artery bypass operations. Inadequate myocardial protection has not been experienced since we began using this method of arresting the heart for cardiac operations.

Adult↗
PubMed1977

Missile migration from lung to heart with delayed systemic embolization.

A bullet migrated from the heart to the left femoral artery in a youth ten days after he sustained a gunshot wound to the right chest. The bullet apparently traversed the pulmonary venous system at the time of the injury and lodged in the interior of the left ventricle. The production of an embolism in the systemic circulation was a delayed and unanticipated event.

Adolescent↗
PubMed1977

Accidental pneumatic rupture of the esophagus.

A case of accidental pneumatic rupture of the thoracic esophagus in a 6-year-old boy is reported. Early operation with transthoracic esophageal repair resulted in survival of the patient, and follow-up at 18 months has demonstrated normal esophageal function and anatomy. A search of the literature has yielded 11 similar cases.

Child↗
PubMed1976

Experience with the radial artery graft for coronary artery bypass.

Forty-eight radial artery grafts and 22 saphenous vein grafts in 37 patients undergoing coronary bypass procedures were studied early postoperatively. Most of the saphenous vein grafts were patent, but one-half of the radial artery grafts were occluded. Failure of the radial artery grafts could not be attributed to unfavorable runoff in the recipient vessels. Radial arteries carrying higher flows and those to vessels having more severe degrees of proximal stenosis occluded with a higher frequency. The radial artery should not be used for coronary bypass.

Aged↗
PubMedDate not supplied

Case report: chronic disseminated intravascular coagulation due to occult carcinoma.

A patient with a relatively localized occult carcinoma of the lung and hemorrhage secondary to chronic disseminated intravascular coagulation (DIC) which continued for eight months is described. Despite continuing DIC two major operations were performed without excessive blood loss. Preoperative heparinization, in vitro clotting of the arterial graft, and temporary postoperative reversal of systemic heparin were utilized for abdominal aortic aneurysm resection. Blood product replacement therapy facilitated an emergency laparotomy. The patient was also managed successfully for several months without anticoagulant therapy. A hypothesis that vascular thrombi are not a necessary prerequisite for DIC is proposed. This hypothesis is based on the absence of thrombi or evidence of ischemia in this patient and in others and is supported by experimental observations made by other investigators.

Aged↗
PubMedDate not supplied

Total pericardial replacement. Design and preliminary evaluation in greyhounds.

Existing pericardial substitutes, used for the prevention of pericardial and pleural adhesions to the epicardium, are in the form of a patch. To improve on this concept, an elastic, anatomically correct, implantable sac has been developed for total pericardial replacement. Total pericardial substitutes fabricated from Silastic silicone rubber and Mitrathane polyetherurethane urea were implanted in greyhound dogs and harvested at 8 weeks. Pericardial adhesions were prevented by the substitutes that remained intact. Fibrous tissue formation had occurred on the epicardium underlying the substitutes, the extent being more severe in response to the Silastic compared with the Mitrathane. However, the Silastic was superior to the Mitrathane in retention of its tensile strength and elastic modulus over the implant period (p less than 0.05). Further development of total pericardial substitutes from different materials shows promise.

Animals↗
PubMedDate not supplied

In vivo results of hydrogel composite pericardial substitutes.

In this study, two improved pericardial patches were developed and evaluated for their efficacy as pericardial substitutes. The patches are composites consisting of a hydrogel (PHEMA) that coats an underlying mesh (either ETFE or PET). Studies were conducted using subcutaneous implants in rats and pericardial patch implants in greyhound dogs. Adhesions between the substitute and pericardium and the epicardium were minimal. The ETFE composite patch caused an unacceptable epicardial reaction. The PET patch results were encouraging; the epicardium was largely unaffected by the patch.

Animals↗
PubMedDate not supplied

A hydrogel pericardial patch.

Patients undergoing repeat cardiac operations are higher operative risks than those undergoing an initial cardiac procedure because adhesion formation can occur if the native pericardium is not closed. A unique composite patch that may be used to augment the pericardial tissue when primary closure is not possible has been developed. The patch is made of a hydrogel, poly (2-hydroxyethyl methacrylate), reinforced with an ethylene tetrafluoroethylene (ETFE) mesh. The mesh provides the needed mechanical properties, whereas the patch's surface properties are comparable to the hydrogel. Two types of patches were fabricated: one with the mesh weave at a perpendicular orientation and one at 45 degrees to the principle loading direction. The patches were mechanically tested and compared with canine pericardium. Ultimate tensile strength of the patches is not significantly different from canine pericardium (p less than 0.05), are the patch suture strength is nearly twice that of canine pericardium. The perpendicular patch is stiffer than canine pericardium, whereas the 45 degree patch is not (p less than 0.05). The 45 degree patch shows considerable promise as a pericardial substitute because it closely matches the properties native canine pericardium.

Animals↗