PubMed Health⌕ Search

Biomedical subjects

J Edgerton

Publications and source records attributed to J Edgerton.

6 recordsLinked to original sources
PubMed2001

Left mini-thoracotomy for beating heart bypass grafting: a safe alternative to high-risk intervention for selected grafting of the circumflex artery distribution.

BACKGROUND: Progression of disease and bypass graft attrition results in a population of patients who require repeated coronary interventions. Frequently, these patients have patent internal mammary artery grafts and require isolated intervention to the circumflex distribution. As an alternative to high-risk repeated sternotomy and conventional bypass surgery or catheter-based intervention, the circumflex marginal vessels may be approached by thoracotomy. We reviewed our experience in revascularizing the circumflex distribution with off-pump techniques via left mini-thoracotomy. METHODS AND RESULTS: Thirty-two patients underwent off-pump bypass grafting of the circumflex vessels via thoracotomy from December 1995 to April 2000. Twenty-seven patients presented with circumflex disease after having previous bypass grafting. Five patients, who presented with circumflex disease and either nondiseased or ungraftable disease in their other arteries, were revascularized as a primary procedure. There was no observed mortality. Seven patients (22%) required inotropes on leaving the operating room, and 3 patients (9.4%) received transfusion of packed red blood cells. There was 1 reoperation for bleeding and 1 patient with a postoperative neurological deficit. There were no perioperative myocardial infarctions. The average length of stay was 4.8 days from time of surgery to discharge. CONCLUSIONS: Off-pump grafting via thoracotomy provides a safe and effective alternative approach for patients requiring limited revascularization. Potential cardiac injury and danger to viable grafts from repeated sternotomy is minimized, and manipulation of the diseased ascending aorta is avoided. Morbidity, hospital length of stay, and cost are less than for conventional repeated coronary bypass surgery.

Arteries↗
PubMed1999

Off-pump multivessel coronary artery bypass utilizing the Octopus tissue stabilization system: initial experience in 374 patients from three separate centers.

BACKGROUND: Renewed interest in coronary artery bypass without heart-lung support has lead to the development of specialized instrumentation to permit surgical exposure and grafting in all territories of the beating heart. This report summarizes the results of a multicenter, prospective trial using a single system of mechanical stabilization for multivessel revascularization without cardiopulmonary bypass. METHODS: Three principal investigators at different institutions performed off-pump coronary grafting utilizing the Medtronic Octopus suction stabilization system which provides a motionless region encompassing the target coronary artery. Positioning and stabilization strategies evolved during the trial but eventually lead to a consistent approach for accessing all regions of the heart. Clinical data sets were collected prospectively and pooled for evaluation of early and short-term endpoints of success. RESULTS: A total of 374 patients underwent beating heart coronary bypass procedures with only a single death for an in-hospital 30-day mortality rate of 0.26%. There were 140 single-vessel revascularizations (37.4% of patients), 119 double coronary grafts (31.8%), 90 triple-vessel grafts (24.1%), and 25 four-vessel grafts (6.7%), for a mean of 1.96 grafts per patient. If the single vessel cases are removed from analysis, the mean number of grafts performed in the multivessel cohort was 2.6 grafts per patient. All anatomic regions of the heart were successfully grafted including traditionally difficult locations such as the obtuse marginal branches of the circumflex and posterior descending branches of the right coronary artery. Only one patient suffered a new neurologic deficit which occurred 15 days postoperatively, for an overall incidence of only 0.26%. No patient required a new intra-aortic balloon pump or dialysis for renal insufficiency. The incidence of atrial fibrillation (12.8%) was age related and essentially unchanged from the overall incidence observed in patients operated at the same institutions using conventional techniques. CONCLUSIONS: Multivessel grafting on the beating heart using the Octopus stabilization system results in remarkably low perioperative mortality and morbidity, with very low incidences of cerebrovascular, renal, and respiratory complications. However, the incidence of postoperative atrial fibrillation is not reduced. Expanded clinical use of beating heart surgery with suction-based stabilization appears to be a promising technique for achieving global revascularization without the need for cardiopulmonary bypass.

Coronary Artery Bypass↗
PubMed1997

Identification of functionally distinct isoforms of the N-type Ca2+ channel in rat sympathetic ganglia and brain.

The N channel is critical for regulating release of neurotransmitter at many synapses, and even subtle differences in its activity would be expected to influence the efficacy of synaptic transmission. Although several splice variants of the N channel are expressed in the mammalian nervous system, their biological importance is presently unclear. Here, we show that variants of the alpha1B subunit of the N channel are expressed in sympathetic ganglia and that alternative splicing within IIIS3-S4 and IVS3-S4 generate kinetically distinct channels. We further show a striking difference between the expression pattern of the S3-S4 variants in brain and peripheral ganglia and conclude that the brain-dominant form of the N channel gates 2-to-4-fold more rapidly than that predominant in ganglia.

Alternative Splicing↗
PubMed1995

Electroporation-induced damage in mammalian cell DNA.

Electroporation induced damage in the DNA of HL60 cells has been investigated by alkaline elution techniques. DNA damage is minimised by reducing the total charge applied (i.e., voltage x capacitance). Reduction of either of these electrical parameters, however, compromises the induced permeability of the cells to small molecules. The data presented concerning the effects of voltage and capacitance on DNA damage and the permeability of cells can be used to specify optimum conditions for electroporation in which DNA damage is minimised. The duration for which the current is applied can be seen to have a significant effect on the level of DNA damage. A modest temperature rise may occur when an electric charge is passed through electroporation buffer, but this event alone does not induce DNA damage in cells. The effect of voltage upon the permeability of HL60 cells to fluorescent-labelled molecules of varying molecular weight is reported.

Buffers↗
PubMed1991

The subpectoral pocket: the preferred implant site for pediatric pacemakers.

Implantation technique for pediatric pacemaking has evolved from predominantly epicardial to predominantly endocardial. One of the potential problems with endocardial pacing in children is their very thin subcutaneous tissue, which can result in an unpleasant cosmetic result. The superficialness of the pacemaker pulse generator also may render it more susceptible to erosion and infection. A series is presented of pediatric patients who underwent implantation of a transvenous bipolar pacing system in the pediatric catheterization laboratory. The pacemaker was implanted under the pectoralis major muscle after a muscle spreading incision was made. The lead was also introduced into the subclavian vein under the pectoralis muscle. No complications resulted, and the cosmetic result was judged to be good to excellent by the parents and physicians. No infections or erosions occurred. The subpectoral pocket is recommended as the preferred site for implantation of transvenous pacemakers in pediatric patients.

Adolescent↗