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The major cause of nonsurgical bleeding after cardiopulmonary bypass is delayed recovery of platelet count and function. Recovery of platelet count and function was compared in 27 patients who were randomized preoperatively to receive after cardiopulmonary bypass either 1 unit of fresh whole blood (15 patients) or 10 units of platelet concentrates (12 patients). Platelet count, bleeding time, platelet aggregation (adenosine diphosphate, collagen, epinephrine, and ristocetin) and platelet thromboxane formation were abnormal after cardiopulmonary bypass in all the patients. The increase of platelet count after 1 unit of fresh whole blood (from 115 +/- 32 X 10(9)/L to 148.5 +/- 36 X 10(9)/L) was similar to that achieved by 4 units of platelets (from 140 +/- 61 X 10(9)/L to 171 +/- 60 X 10(9)/L). The increase was doubled after 10 platelet units (from 140 +/- 61 X 10(9)/L to 209 +/- 55 X 10(9)/L). Bleeding time returned to normal values after fresh whole blood or after 8 platelet units. However, platelet thromboxane formation was higher after 1 unit of fresh whole blood than after 10 platelet units (95 +/- 25 versus 46 +/- 35 ng/ml, p less than 0.05), as was platelet aggregation response to collagen and epinephrine. The 24-hour blood loss was smaller in the fresh whole blood group (560 +/- 420 ml versus 770 +/- 360 ml), although the difference was not statistically significant. The results suggest that the hemostatic effect of 1 unit fresh whole blood after cardiopulmonary bypass is at least equal, if not superior, to the effect of 10 units of platelets.

The routine use of an arbitrary fixed left atrial (LA) pressure during volume load after aortocoronary bypass operation was compared with use of an individualized postoperative target LA pressure according to a calculated preoperative LA pressure in two groups of consecutive patients. The preoperative LA pressure of each patient was calculated from the preoperative left ventricular end-diastolic pressure (LVEDP) by the formula: mean LA pressure = 1.16 x LVEDP - 8.53. Left atrial pressure, mean arterial pressure, mean right atrial pressure, and cardiac output were measured simultaneously on arrival at the intensive care unit and 60 minutes later. Cardiac index (CI) and systemic vascular resistance (SVR) were calculated from the variables already mentioned. Results indicated a significantly higher CI and significantly lower SVR in patients in whom volume load was aimed at the calculated preoperative LA pressure. It was concluded that the optimal postoperative LA pressure is specific for each patient and depends on the preoperative LVEDP.

In 20 patients who underwent a modified surgical repair of tetrad of Fallot complete right bundle branch block developed in only 8 (40 percent). Standard and intraoperative conduction studies indicated that in these patients the right bundle branch block was due to injury of the right bundle branch near the ventricular septal defect (proximal right bundle branch block). The modified operative technique is aimed at minimizing the injury to the right ventricle and it includes a significantly shorter than usual ventriculotomy incision and avoidance of the septal (moderator) band during infundibulectomy. Intra- and postoperative hemodynamic studies of these patients revealed that relief of the right ventricular outflow obstruction was optimal.

The results of membranectomy and deep myectomy in the left ventricular outflow tract were compared to those of membranectomy and myotomy in 42 patients who underwent surgical repair of discrete and tunnel subaortic stenosis. Fifteen consecutive patients (Group A) underwent membranectomy and myotomy, and 27 consecutive patients (Group B) underwent membranectomy and myectomy. Two patients of Group A and nine of Group B had tunnel subaortic stenosis. The preoperative mean (+/- standard deviation) peak systolic gradients across the left ventricular outflow tract in patients with discrete subaortic stenosis types I and II were 64 +/- 29 mm Hg in Group A and 52 +/- 3 mm Hg in Group B (p = not significant). In the patients with tunnel subaortic stenosis the preoperative mean gradients were 97 +/- 74 mm Hg in Group A and 73 +/- 26 mm Hg in Group B (p = not significant). In patients with discrete subaortic stenosis types I and II, postoperative catheterization at a mean follow-up of 21 months revealed residual mean gradients of 29 +/- 24 mm Hg in Group A and 10 +/- 13 mm Hg in Group B (p less than 0.01). In the patients with tunnel subaortic stenosis, the postoperative mean gradients were 25 +/- 7 and 30 +/- 30 mm Hg in Groups A and B, respectively (p = not significant). We conclude that in the surgical management of discrete subaortic stenosis types I and II, deep myectomy (in addition to membranectomy) produces better relief of the left ventricular outflow obstruction than do membranectomy and myotomy. In patients with tunnel subaortic stenosis myectomy is less effective than in the non-tunnel type but still produces acceptable results and may delay radical procedures to a later age.

To evaluate the effect of fresh whole blood transfusion versus platelet concentrates transfusion on platelet aggregation after cardiac operations, 24 patients were randomized to receive either one unit of fresh whole blood (12 patients) or 10 platelet units (12 patients) after cardiopulmonary bypass. Platelet aggregation on extracellular matrix, platelet count, and mean platelet volume were studied preoperatively, at termination of cardiopulmonary bypass, after protamine administration, and after the transfusion of fresh whole blood or after transfusion of each two platelet units. Extracellular matrix produced by cultured bovine corneal cells closely resembles the vascular subendothelial basal lamina, and is an ideal in vitro model in the study of platelet interaction with the subendothelium. Platelet aggregation on extracellular matrix, studied by a scanning electron microscope, was graded from 1 to 4, wherein grade 1 represents nonactivated platelets and grade 4 a mature platelet aggregate. With this grading system, the two groups were similar in preoperative values (3.3 +/- 0.9 versus 3.7 +/- 0.4) and values after cardiopulmonary bypass (1.5 +/- 1.0 in both groups). One unit of fresh whole blood restored platelet aggregation on extracellular matrix to preoperative status (3.0 +/- 1.0), whereas eight platelet units were needed for the same result (3.2 +/- 0.8). One unit of fresh whole blood increased platelet count in a manner similar to that achieved by six platelet units and increased mean platelet volume to a level higher than that achieved by 10 platelet units. These results suggest that the effect of one unit of fresh whole blood on platelet aggregation after cardiopulmonary bypass is at least equal, if not superior, to the effect of 8 to 10 platelet units.

The effectiveness of deep systemic hypothermia (20 degrees C) in myocardial protection during aortic cross-clamping was elevated. Seventy-one consecutive patients undergoing coronary artery bypass grafting were divided into two groups. In group A (32 patients) systemic temperature was reduced to an average of 26.8 degrees C (range 24 degrees to 28 degrees C) and the amount of cardioplegic solution infused totalled 1,000 to 1,200 cc. In Group B (39 patients) systemic temperature was reduced to an average of 20.8 degrees C (17 degrees to 23 degrees C) and the total amount of cardioplegic solution infused was 100 to 300 cc. The mean number of coronary (distal) anastomoses per patient was 4.46 in Group A and 4.51 in Group B. There were no surgical deaths, perioperative infarcts, or neurologic damage in either group. Postoperative catecholamine dependence was used as an indicator for inadequate myocardial protection. Catecholamine support was required by 18 patients (56.25%) in Group A and two patients (5.13%) in Group B (p less than 0.0001). Patients of both groups who received five or six coronary anastomoses, whose aortic cross-clamp time was 60 minutes or more, and whose preoperative left ventricular ejection fractions were above 50% were compared: Ten of the 11 (91%) in Group A required catecholamine support as opposed to none of the 12 in Group B (p less than 0.0001). No significant difference in the incidence of catecholamine requirement was found between patients of both groups whose aortic cross-clamp time was less than 60 minutes (2/13 patients in Group A and 2/21 patients in Group B), regardless of their preoperative left ventricular ejection fraction. We conclude that when aortic cross-clamp time exceeds 60 minutes, that is, when multiple distal anastomoses are performed, deep systemic hypothermia is a simple and effective method for myocardial preservation.

The phenomenon of a pressure gradient between central and radial arteries was evaluated in 48 patients immediately after coronary artery bypass operations. All were in stable hemodynamic condition, none receiving catecholamine support. In eight patients (Group A) mean femoral pressure was significantly higher than mean radial pressure (range 10 to 30 mm Hg). In the remaining 40 (Group B) radial and femoral pressures were equal. Mean cardiac index (thermodilution) was 3.3 +/- 0.68 versus 2.1 +/- 0.4 L/min/m2, systemic vascular resistance 1,181 +/- 218.4 versus 2,049 +/- 501 dynes/sec/cm-5, toe temperature 23.8 degrees +/- 1.2 degrees C versus 24.02 degrees +/- 0.9 degrees C, core temperature 33.9 degrees +/- 0.5 degrees C versus 34.1 degrees +/- 0.6 degrees C, mixed venous oxygen saturation 78% +/- 3% versus 62% +/- 5%, and peak radial dP/dt 1,485 +/- 366 versus 2,028 +/- 392 in Groups A and B, respectively. These data indicate, first, that the low radial pressures measured in Group A patients did not represent the true central aortic pressures; that is, they were false. Second, these low pressures had nothing to do with compromised cardiac function; rather, they were due to peripheral constriction and volume factors and also probably to proximal shunting. It is therefore recommended that while the chest is still open, if a discrepancy exists between a low radial artery pressure, a high palpable aortic pressure, and a satisfactory cardiac contraction, a femoral cannula for pressure measurement should be inserted. Treatment is by blood infusion until the femoral-radial gradient has been abolished.

One hundred and fifty nine patients underwent surgery for abdominal aortic aneurysm (AAA) from 1975 to 1985. Of these, a tube graft was inserted in 86 patients (55.1%). Immediate and late results of these 86 patients were evaluated retrospectively as to the effect of concomitant common iliac artery (CIA) disease on early and late results. There were 77 males and nine females aged 35-91 (average 70.7) years. Surgery was elective in 44 patients (51.2%), and as an emergency due to expanding, ruptured or thrombosed AAA in 42 patients (48.8%). The CIAs showed unilateral or bilateral aneurysmal dilatation or atherosclerotic changes in 47 patients (54.7%). At the time of surgery additional bypass grafting from the tube graft to one femoral artery was performed in four patients, and patch angioplasty to the CIA in one. Operative mortality was 4.6% (two patients) in the elective group, and 45.2% (19 patients) in the emergency operations. Follow-up was 94% complete for a mean of 4.1 (range 0.5-10) years). Late mortality for the whole series was 20.0% (12 patients). Only one patient died of a cause related to the AAA operation. All but one of the 48 late survivors are free of any peripheral vascular problems. We conclude that tube graft replacement of AAA is a good choice even in the presence of some degree of CIA atherosclerosis or aneurysmal dilatation.

Myocardial revascularization is usually considered "complete" if all stenosed major coronaries are bypassed. Attempts were made to compare the results of this method with an approach by which each of the following five left ventricular infarct-prone segments is revascularized if ischemic: anteroseptal, anterolateral, posterosuperior, posteroinferior, and diaphragmatic. Two subsets of patients were studied. A total of 366 patients (Group A) who underwent aortacoronary bypass operations from 1980 to 1982 were followed up for a mean of 16.3 (6 to 43) months and were retrospectively divided into two groups: Group A1 (120 patients) had incomplete segmental revascularization (mean of 3.4 grafts per patient) and Group A2 (246 patients) had complete segmental revascularization (4.0 grafts per patient) (p less than 0.0001). Groups A1 and A2 were identical in all clinical and angiographic parameters: unstable angina, 60%; previous myocardial infarction, 70%; left main stenosis, 10%; and ejection fraction less than 30%, 2%. Overall operative mortality was 2.3%. Results in Groups A1 and A2, respectively, were as follows: operative mortality, 5.8% versus 0.8% (p less than 0.005); perioperative myocardial infarction, 6.9% versus 0.8% (p less than 0.0005); 35 month survival rate, 93.3% versus 97.9% (p less than 0.02); total freedom from symptoms, 54.1% versus 68.3% (p less than 0.025). In addition, 151 patients operated on in 1984 (Group B) were studied prospectively with regard to operative mortality and perioperative myocardial infarction, and the results were identical to those in Group A. Compared to conventional complete revascularization, complete segmental revascularization provides better results.

Continuous postoperative right and left ventricular diastolic pressures were measured in 12 consecutive patients undergoing pulmonic valvotomy and in 13 consecutive patients undergoing membranectomy and myectomy for discrete subaortic stenosis. All 25 patients had positive preoperative diastolic ventricular pressures. Negative ventricular diastolic pressure was detected immediately postoperatively in all 25. The lowest left ventricular negative diastolic pressure was -38 mm Hg, and the lowest right ventricular negative diastolic pressure was -28 mm Hg. Intravenous administration of volume (blood) reduced the right ventricular negative diastolic pressure significantly (from -14.8 +/- 9.2 to -6.4 +/- 6.8 mm Hg, p less than 0.001) and decreased right ventricular rate of pressure rise from 1100 +/- 320 to 380 +/- 180. Left ventricular negative diastolic pressure was not significantly affected (from -17 +/- 11 to -14.7 +/- 11 mm Hg). Left ventricular negative diastolic pressure disappeared spontaneously 6 to 9 hours postoperatively in association with a spontaneous decrease of left ventricular rate of pressure rise (from 3450 +/- 610 to 2100 +/- 660 mm Hg/sec). We conclude that negative right and left ventricular pressures are common findings immediately after surgical relief of outflow obstructions. Hypercontractility is the main reason for these phenomena. Volume load reduces the right ventricular negative diastolic pressure, but has insignificant effect on left ventricular negative diastolic pressure. The pathogenesis of the hypercontractility is discussed.

Between 1980 and 1987, 40 patients with ischemic mitral insufficiency underwent mitral valve replacement (with a mechanical prosthesis) and coronary bypass grafting, 3.5 grafts per patient. The posterior mitral leaflet was preserved in 17 and resected in 23. Five arrived at operation in cardiogenic shock, 15 after recurrent episodes of pulmonary edema, and 20 electively, but in congestive heart failure. Twenty-five had unstable angina, and the remaining had chronic angina. Perioperative and early deaths occurred only in patients with an ejection fraction less than 35%. None of the 21 patients with an ejection fraction greater than 35% died, whereas eight of 19 with an ejection fraction less than 35% died, whereas eight of 19 with an ejection fraction less than 35% died (p less than 0.001). When causes of death in patients with an ejection fraction less than 35% were studied, operative and early mortality was zero of seven with preservation of the posterior mitral leaflet versus eight of 11 with excision of the leaflet (p = 0.035). We concluded that the high mortality in mitral valve replacement for ischemic mitral insufficiency is linked to an ejection fraction less than or equal to 35% and, in this particular group of patients, is due to the surgical destruction of the left ventricular chordae tendineae supportive apparatus. Preservation of this apparatus by preservation of the posterior mitral leaflet drastically reduces operative and early mortality. Preoperative cardiogenic shock, left ventricular aneurysmectomy, and multiple grafting (up to five grafts per patient) did not increase the risk of operation. Extensive revascularization (3.5 grafts per patient) provides improved long-term results.