Follette Dm

Effects of pulsatile assistance and nonpulsatile flow on subendocardial perfusion during cardiopulmonary bypass

We compared the effects of pulsatile and nonpulsatile perfusion in 12 dogs on extracorporeal circulation. In beating empty and fibrillating hearts at 37 degrees and 28 degrees C, coronary blood flow was measured by flowmeter and microspheres at diastolic pressures ranging between 50 and 130 mm Hg. At fixed systemic flow rates (range, 600 to 2,400 ml/min), pulsatile perfusion produced a transient (3 to 4 second) augmentation of diastolic pressure and then resulted in the following: (1) decreased peripheral vascular resistance (p less than 0.05); (2) unchanged peak diastolic pressure (compared with nonpulsatile perfusion); (3) decreased mean aortic pressure (6 to 37%) (p less than 0.05); (4) decreased coronary blood flow (10 to 45%) (p less than 0.05); and (5) decreased subendocardial blood flow (from 512 to 438 ml/100 gm/min) (p less than 0.05). Pulsatile perfusion in beating hearts (37 degrees or 28 degrees C) did not reduce subendocardial vascular resistance, but did improve subendocardial perfusion by 27% and 36% in fibrillating hearts at 37 degrees and 28 degrees C, respectively. We conclude that with the exception of ventricular fibrillation, pulsatile assistance offers no advantage over nonpulsatile perfusion and has the potential disadvantage of requiring higher pump flow rates to achieve any desired level of coronary and subendocardial flow.

Gastroesophageal fundoplication for reflux in infants and children.

Fifteen infants and young children with symptomatic gastroesophageal reflux underwent fundoplication during a 6 1/2-yr period. Standard barium esophagrams clearly demonstrated reflux in only 10 of the 15 patients; however, cine esophagrams indicated reflux in the remaining patients. Esophagoscopy with mucosal biopsy demonstrated esophagitis in 9 of the 10 patients in whom it was performed, and it is a very helpful diagnostic procedure. Esophageal manometry showed low sphincter pressures in each of 7 patients. Fundoplication was performed when there was (1) persistent reflux after a 3-wk hospital course of vigorous medical management, (2) failure to gain weight, (3) malnutrition, (4) recurrent aspiration, (5) esophagitis, or (6) stricture. Concomitant gastrostomy prevented the gas bloat syndrome in all patients. All strictures were successfully relieved by postoperative dilatation (average four per patient). Esophageal replacement is rarely indicated for strictures due to reflux in children. No deaths or major complications occurred following operation. Each of the patients has been relieved of clinical reflux, and each has gained weight more rapidly than preoperatively. Follow-up esophagrams on each of the patients show absence of reflux, and manometry shows the low esophageal sphincter pressure to be increased an average of 10 mm Hg above preoperative values. Since the results of Nissen fundoplication to correct reflux in infants and young children are highly satisfactory, and since the consequences of persistent reflux may be severe, a fairly aggressive approach should be taken in the management of symptomatic reflux.

Coronary artery bypass in hereditary factor XI deficiency.

Hereditary factor XI deficiency is a disorder of coagulation that has been associated with postoperative bleeding. Because cardiopulmonary bypass itself induces transient abnormalities in hemostasis, the patient with factor XI deficiency could be at increased risk for bleeding after cardiac surgical procedures. We report the successful management of a 61-year-old man with hereditary factor XI deficiency who had coronary artery bypass. Treatment with low-dose aspirin, begun 24 hours postoperatively for graft patency, was well tolerated. Once recognized and aggressively treated, factor XI deficiency does not appear to be a contraindication to potentially life-saving procedures like coronary revascularization.