Coronary artery bypass without cardiopulmonary bypass: analysis of short-term and mid-term outcome in 220 patients

Two hundred twenty patients, preferentially those with high-risk conditions, underwent coronary artery bypass grafting without cardiopulmonary bypass. Early unfavorable outcome events included operative mortality (7 patients, 3.2%), nonfatal perioperative myocardial infarction (6 patients, 2.7%), cerebrovascular accident (1 patient, 0.4%), and sternal infection (3 patients, 1.4%). There were two deaths (13%) among 15 patients with calcified aorta and four (12%) in 33 patients who underwent emergency operation. Multivariate analysis revealed these two risk factors to be the only predictors of early mortality (odds ratios, 8.0 and 9.8, respectively). Preoperative risk factors such as left ventricular dysfunction (ejection fraction < or = 35%) (40 patients, 18%), congestive heart failure (46 patients, 21%), acute myocardial infarction (59 patients, 27%), cardiogenic shock (7 patients, 3%), age 70 years or older (59 patients, 27%), renal failure (19 patients, 9%), and cerebrovascular accident and carotid disease (11 patients, 5%) were not found to be major predictors of early mortality or unfavorable outcome. During 12 months of follow-up (range 1 to 21 months), there were four cardiac and three noncardiac deaths (1-year actuarial survival 93%) and 17 cases (7.7%) of early return of angina. Calcified aorta, nonuse of the internal mammary artery, reoperation, and diabetes mellitus were independent predictors of unfavorable events. We conclude that coronary artery bypass grafting without cardiopulmonary bypass can be done with relatively low operative mortality, although there seems to be an increased risk for early return of angina. This procedure should therefore be considered for patients with appropriate coronary anatomy, in whom cardiopulmonary bypass poses a high risk. This procedure is still hazardous with calcified aorta or emergency operation.

Irradiation of fresh whole blood for prevention of transfusion-associated graft-versus-host disease does not impair platelet function and clinical hemostasis after open heart surgery

Since our previous studies suggested that the transfusion of 1 unit fresh whole blood (FWB) after cardiopulmonary bypass (CPB) using a bubble oxygenator may provide hemostatic benefit equivalent to 8-10 units of platelet concentrates, we have routinely used FWB at the termination of CPB. Two patients who received FWB and developed transfusion-associated graft-versus-host disease (TA-GVHD) prompted us to investigate the effect of irradiation of FWB on platelet and clinical hemostasis. Twenty-four patients were randomized to receive either 1 unit FWB (12 patients), or 1 unit irradiated FWB (IrFWB, 1,500 cGy,12 patients) after CPB. Platelet aggregation on extracellular matrix, studied by a scanning electron microscope and graded from 1 to 4 (from poor to excellent aggregation), was similar in both groups preoperatively [3.3 +/- 0.9 (FWB) and 3.5 +/- 0.5 (Ir FWB)], and at the end of CPB [1.8 +/- 1.2 (FWB) and 1.9 +/- 0.9 (IrFWB)]. Platelet aggregation was similar after transfusion of FWB (3.0 +/- 1.0) and after IrFWB (3.2 +/- 0.8), as was the increase in platelet count. Twenty-four hours total postoperative bleeding was similar (560 +/- 420 and 523 +/- 236 ml for FWB and IrFWB, respectively). We conclude that irradiation of FWB for prevention of TA-GVHD does not impair platelet aggregating capacity, and can be used when blood is donated by the patient's next of kin.

Aprotinin improves hemostasis after cardiopulmonary bypass better than single-donor platelet concentrate

Platelet transfusion and aprotinin administration improve platelet function and clinical hemostasis after extracorporeal circulation. To compare two methods of improving postoperative hemostasis, we preoperatively randomized 40 patients undergoing various open heart procedures into two groups. Group A included 20 patients who, immediately after bypass, received single-donor plateletpheresis concentrates collected from ABO-compatible donors (Baxter Autopheresis-C System). They were compared with 20 patients who received high-dose aprotinin (6 x 10(6) KIU) before and during cardiopulmonary bypass (group B). Group A patients showed significantly higher platelet count after single-donor plateletpheresis concentrate transfusion (157 +/- 36 x 10(9)/L compared with 118 +/- 42 x 10(9)/L (p < 0.05). However, platelet aggregation on extracellular matrix was better in group B (3.4 +/- 0.7 versus 2.8 +/- 0.9; p < 0.05). Total 24-hour blood loss and exposure to homologous blood products were significantly less in group B (396 +/- 125 mL and 1.1 +/- 1.6 units compared with 617 +/- 233 mL and 5.4 +/- 3.4 units; p < 0.01). Despite higher platelet count in patients after single-donor plateletpheresis concentrates transfusion, hemostasis in patients receiving aprotinin is better due to improved platelet function.

Synthesis and histamine H2-receptor antagonist activity of 4-(1-pyrazolyl)butanamides, guanidinopyrazoles, and related compounds

A series of 4-(1-pyrazolyl)butanamides, pyrazolylalkyl cyanoguanidines, and related compounds with diverse functional groups (e.g. nitro, amino, guanidino groups) in the 3-position of the pyrazole ring was prepared via 4-(3-nitro-1-pyrazolyl)butanenitrile (5) and the corresponding carboxylic acid 7 as central intermediates. The amides 9a-d were prepared from the primary amines 8a-d which represent partial structures of the H2-receptor antagonists roxatidine, cimetidine, ranitidine, and famotidine. The roxatidine-derived 4-(3-nitro-1-pyrazolyl)butanamide (9a) proved to be the compound with the highest H2-receptor antagonist activity of 23 compounds tested at the isolated guinea pig right atrium preparation, achieving about 6 times famotidine's or 160 times cimetidine's potency. By contrast, in Ghosh-Schild rats 9a did not inhibit histamine-stimulated gastric acid secretion at a dosage of 0.1 mumol/kg i.v. Compounds 20a (the 3-(trifluoroethyl-guanidino)pyrazole analogue of 9a, 12a (the cyanoguanidine analogue) and N-(4-[3-(trifluoroethylguanidino)-1-pyrazolyl]butyl)cyanogua nidine (29), which are about as active as famotidine in the atrium, turned out to be very potent inhibitors of gastric acid secretion as well (e.g., 29: 74% inhibition at 0.025 mumol/kg). These compounds are comparable to famotidine in the rat stomach and by far superior to cimetidine and ranitidine in this test system.

Acquired left ventricular-right atrial communication caused by infective endocarditis detected by transesophageal echocardiography: case report and review of the literature

Acquired left ventricular-right atrial communication due to infective endocarditis was diagnosed in a 64-year-old patient by transesophageal echocardiography and confirmed by cardiac catheterization. The patient was initially treated medically and then referred for corrective surgery.

Transcriptional activation of a ras-like gene (kir) by oncogenic tyrosine kinases

We report the characterization of a member of the ras gene family that is overexpressed in cells transformed by abl tyrosine kinase oncogenes. The gene, named kir (for kinase-inducible ras-like), is induced at the transcriptional level. kir mRNA has a rapid turnover and encodes a protein of 33 kDa with guanine nucleotide-binding activity but undetectable intrinsic GTPase activity. kir was cloned by differential screening of genes present in fully malignant versus growth factor-independent cell lines expressing wild-type or mutant forms of BCR/ABL. BCR/ABL and v-Abl induce transcription of the kir gene via specific signaling pathway(s), but kir overexpression alone is not sufficient to mediate transformation.

Coronary artery by-pass without cardiopulmonary by-pass for patients with severe left ventricular dysfunction

OBJECTIVES

To evaluate results of coronary artery bypass grafting (CABG) without cardiopulmonary by-pass (CPB) for patients with severe left ventricular dysfunction.

MATERIALS AND METHODS

Fifty-three patients with severe LV dysfunction (EF < 35%) underwent CABG without cardiopulmonary by-pass (CPB) between December 1991 and December 1993. They comprise 22% of 242 patients operated on without CPB by one of the authors (RM) in this period. There were 45 (85%) males and eight (15%) females. Twelve (23%) patients were over 70 years. Nine (17%) were re-do CABG. Ten (19%) were referred for operation within the first 24 hours of evolving MI, and 13 (25%) up to two weeks after acute MI. Nine (17%) had preoperative EF < 20%, and six patients (11%) were in cardiogenic shock. Mean number of grafts/pt was 1.8 and IMA was used in 41 (77%). Only 14 patients (26%) received a graft to a circumflex marginal artery. Ischemic time was 8 +/- 4 min/graft (mean +/- SD) when anastomosed to the LAD or RCA, and 14 +/- 7 min/graft when anastomosed to a marginal branch.

RESULTS

One patient (1.9%) died perioperatively, and two (3.7%) suffered a non-fatal MI. At two-year follow-up there were three late deaths, one of them from cancer. Three patients had return of angina, two of them were reoperated upon.

CONCLUSIONS

These results suggest that CABG without CPB may be advantageous for patients with severe LV dysfunction.

Coronary by-pass reoperations without cardiopulmonary by-pass: the Israeli experience

OBJECTIVES

To evaluate results of coronary artery by-pass grafting (CABG) reoperations without cardiopulmonary by-pass (CPB).

MATERIALS AND METHODS

Thirty-two patients underwent CABG reoperation with CPB between December 1991 and December 1993. There were 29 (91%) males, and 3 (9%) females. Mean age was 62 +/- 7 years. Five (16%) were operated on emergently, two (6%) of them during cardiogenic shock. Three (9%) were referred for operation up to two weeks following acute MI. Six (19%) had preoperative EF < 35%. Significant associated systemic diseases included previous CVA in two patients (6%), calcified aorta in two (6%), peripheral vascular disease in six (19%), renal failure in one (3%), and severe COPD in one (3%). Mean number of grafts/pt was 1.5 (range 1-3), and IMA was used in 26 (81%) of patients. Only nine patients (28%) received a graft to a circumflex marginal artery, six (66%) of whom were operated on through left thoracotomy.

RESULTS

Only two patients (6%) had low output syndrome postoperatively; one was supported with catecholamines, and the other with intraaortic balloon pump. Hospital stay was 6.1 +/- 1.5 days (mean +/- SD). Early unfavorable outcome included operative death in one patient (3.1%), non-fatal MI in two (6%), and sternal infection in one (3%). Follow-up (10 +/- 5 months, mean +/- SD) showed two late deaths (one cardiac, and one carcinoma), one (3%) non-fatal MI, and return of angina in three (9%) patients.

CONCLUSIONS

CABG reoperations without CPB should be considered, particularly for revascularization of the LAD and RCA systems. Left thoracotomy is optional for patients with disease confined to circumflex and LAD systems.

Basaloid squamous cell carcinoma of floor of mouth

BACKGROUND

Only five cases of basaloid squamous cell carcinoma (BSCC), a rare tumor of head and neck, have been reported to involve the floor of mouth.

METHODS

Clinicopathologic and immunohistochemical features of eight BSCC of floor of mouth were studied to evaluate the significance of the basaloid features.

RESULTS

Five patients were male and three were female. Their mean age was 52 years (range, 39-59). At presentation, one patient was diagnosed with Stage II disease, four were diagnosed with Stage III disease, and three were diagnosed with Stage IV disease. Aside from typical squamous differentiation, each patient had a component of basaloid cells arranged in irregular nests, cords, or pseudoglandular spaces with a brisk mitotic rate, myxoid stroma, and marked tendency for perineural invasion. A panel of immunostains yielded the following results: keratin, +8/8; carcinoembryonic antigen, +3/8; and S-100, chromogranin, and neuron-specific enolase were negative. Mucin stains were negative in all cases. Ultrastructural characterization of three BSCC revealed squamous differentiation of the basaloid cells and a peculiar basal membrane-like material in between them. No neurosecretory granules were present. Seven patients underwent surgery; six of them were also treated with postoperative radiation therapy. In two cases, chemotherapy was added at recurrence. One nonresectable patient received radiation and chemotherapy. At the last follow-up, five patients were dead of disease within 13 months from the diagnosis. One patient died of an unknown cause. Two patients were still alive at the time of this report, 4 and 2 months after treatment. Seven patients had recurrent disease. The authors compared these data with a control group of patients with conventional squamous cell carcinoma (SCC).

CONCLUSIONS

The authors' results indicate that BSCC of floor of mouth is an aggressive variant of SCC and is prognostically worse than the conventional SCC, regardless of the grade of the latter.

Tricuspid valve surgery: recent experience at the Chaim Sheba Medical Center

From 1 January 1989 to 30 June 1992, 35 patients underwent cardiac surgery that included a tricuspid valve (TV) procedure. All had severe TV dysfunction documented by echocardiography, and were in NYHA functional class III-IV. The etiology of TV dysfunction was rheumatic-functional in 19 patients, rheumatic-organic in 13, and infective in 3. Nineteen (54%) had had at least one previous cardiac operation, and in 29 an associated procedure (MVR, AVR, DVR, DVR + CABG) had been performed. The TV was repaired in 27 patients, was replaced by a bioprosthesis in 7, and was excised in 1. There were three (8.6%) operative and two late deaths. Except for two, all surviving patients are in NYHA functional class I-II. In two patients with organic lesions who underwent repair, residual moderate tricuspid regurgitation was observed. We conclude that in these critically ill patients TV surgery can be performed with acceptable results. Long-term fate of a bioprosthesis in the tricuspid position is yet to be determined.

Basaloid squamous cell carcinoma of floor of mouth

BACKGROUND

Only five cases of basaloid squamous cell carcinoma (BSCC), a rare tumor of head and neck, have been reported to involve the floor of mouth.

METHODS

Clinicopathologic and immunohistochemical features of eight BSCC of floor of mouth were studied to evaluate the significance of the basaloid features.

RESULTS

Five patients were male and three were female. Their mean age was 52 years (range, 39-59). At presentation, one patient was diagnosed with Stage II disease, four were diagnosed with Stage III disease, and three were diagnosed with Stage IV disease. Aside from typical squamous differentiation, each patient had a component of basaloid cells arranged in irregular nests, cords, or pseudoglandular spaces with a brisk mitotic rate, myxoid stroma, and marked tendency for perineural invasion. A panel of immunostains yielded the following results: keratin, +8/8; carcinoembryonic antigen, +3/8; and S-100, chromogranin, and neuron-specific enolase were negative. Mucin stains were negative in all cases. Ultrastructural characterization of three BSCC revealed squamous differentiation of the basaloid cells and a peculiar basal membrane-like material in between them. No neurosecretory granules were present. Seven patients underwent surgery; six of them were also treated with postoperative radiation therapy. In two cases, chemotherapy was added at recurrence. One nonresectable patient received radiation and chemotherapy. At the last follow-up, five patients were dead of disease within 13 months from the diagnosis. One patient died of an unknown cause. Two patients were still alive at the time of this report, 4 and 2 months after treatment. Seven patients had recurrent disease. The authors compared these data with a control group of patients with conventional squamous cell carcinoma (SCC).

CONCLUSIONS

The authors' results indicate that BSCC of floor of mouth is an aggressive variant of SCC and is prognostically worse than the conventional SCC, regardless of the grade of the latter.

Platelet protection by low-dose aprotinin in cardiopulmonary bypass: electron microscopic study

To evaluate the effect of low-dose aprotinin during cardiopulmonary bypass on platelet function and clinical hemostasis, 30 patients undergoing various cardiopulmonary bypass procedures employing bubble oxygenators were randomized to receive either low-dose aprotinin (2 x 10(6) KIU in the cardiopulmonary bypass priming solution, 15 patients [group A]) or placebo (15 patients [group B]). Blood samples were collected before and after cardiopulmonary bypass to assess platelet count and aggregation on extracellular matrix, which was studied by a scanning electron microscope. On a scale of 1 to 4 preoperative mean platelet aggregation grades were similar in both groups (3.8 +/- 0.5 and 3.5 +/- 0.5 for groups A and B, respectively). Postoperatively, platelet aggregation on extracellular matrix decreased slightly in group A (2.8 +/- 1.3; p < 0.01) and significantly in group B (1.3 +/- 0.5; p < 0.001). Eleven of the 15 patients in group A remained in aggregation grade 3 or 4 compared with none of the group B patients. Platelet count was similar in both groups preoperatively and postoperatively. Total 24-hour postoperative bleeding and blood requirement were lower in the aprotinin group (487 +/- 121 mL and 2.3 +/- 1.0 units) than in the placebo group (752 +/- 404 mL and 6.8 +/- 5.1 units; p < 0.01). These results show that the use of low-dose aprotinin during cardiopulmonary bypass provides improved postoperative hemostasis, which might be related to the protection of the platelet aggregating capacity.

Aprotinin prevents cardiopulmonary bypass-induced platelet dysfunction. A scanning electron microscope study

BACKGROUND

Administration of aprotinin during extracorporeal circulation reduces blood loss and improves platelet function.

METHODS AND RESULTS

To evaluate the protective effect of aprotinin on platelets, 50 patients undergoing cardiopulmonary bypass were randomized before surgery to one of three groups. Seventeen patients (group A) received continuous high-dose aprotinin (7 x 10(6) KIU) during cardiopulmonary bypass, 17 (group B) received a single bolus of aprotinin in the pump prime (2 x 10(6) KIU), and 16 (group C) received placebo. Scanning electron microscopy was used to evaluate platelet aggregation on extracellular matrix. The platelet function was graded from 1 to 4, with grade 4 being normal aggregation. Immediately after cardiopulmonary bypass, 16 patients in group A (94%) reached preoperative aggregation grade (mean grade, 3.4 +/- 0.7) compared with nine of 17 in group B (52%) (mean grade, 2.9 +/- 1.2), and none in group C (0%) (mean grade, 1.4 +/- 0.5; p < 0.001). Postoperative platelet count did not differ significantly among the three groups. After surgery, group A bled less than groups B and C (395 +/- 120 versus 488 +/- 135 and 780 +/- 408 ml, respectively; p < 0.01). Patients in the aprotinin groups received fewer red blood cell units (0.9 +/- 1.2 and 1.9 +/- 1.2 versus 3.4 +/- 1.9, respectively; p < 0.01) and were exposed to less homologous blood products (1.3 +/- 1.7 and 2.1 +/- 1.1 versus 6.1 +/- 5, respectively; p < 0.001).

CONCLUSIONS

By preserving platelet function, aprotinin improves postoperative hemostasis in all patients who receive high dose and in most who receive low dose.

Synergism between infarct-borne left ventricular dysfunction and cardiomegaly in increasing the risk of coronary bypass surgery

The effect of cardiomegaly on operative and late mortality in patients with left ventricular dysfunction undergoing coronary bypass operation was investigated. The study group consisted of 178 patients whose left ventricular ejection fraction was below 45% and who were operated on from 1978 through 1985. Forty-five patients (group A) had severe left ventricular dysfunction (ejection fraction < 30%) and 133 (group B) had moderate dysfunction (30% > ejection fraction > 45%). Twenty-four of group A (53%) and 54 of group B (41%) patients had cardiomegaly (cardiothoracic ratio on chest x-ray films > 0.5). There were 10 (6%) hospital deaths, four in group A (9%) and six in group B (4.5%). All four deaths in group A and the six deaths in group B were patients who had cardiomegaly. Regardless of the severity of the left ventricular dysfunction, there was no operative death among patients with normal heart size (p < 0.001). Age over 65, bypass time longer than 2 hours, and incomplete revascularization emerged as risk factors. Follow-up ranged from 5 to 13 years (mean 7.8 years). Overall 5-year actuarial survival, including hospital mortality, was 80% +/- 3%. Reduced 5-year survival was observed in patients with cardiomegaly (67% +/- 5% versus 91% +/- 3%, p < 0.05). Five- and 10-year survival of patients from group A with cardiomegaly was 53% +/- 7% and 18% +/- 13%, respectively.

Platelet protection by aprotinin in cardiopulmonary bypass: electron microscopic study

To evaluate the functional integrity of platelets in patients administered the proteinase inhibitor aprotinin during cardiopulmonary bypass, 20 patients undergoing a complicated and prolonged open heart operation were studied. They were randomized to receive either a high dose of aprotinin (total dose, 6 to 7 x 10(6) KIU) before and during cardiopulmonary bypass (10 patients) or a placebo (10 patients). Blood samples were collected preoperatively, at the termination of bypass, and 90 minutes thereafter to assess platelet count and aggregation on extracellular matrix, which was studied by scanning electron microscopy. On a scale of 1 to 4, mean preoperative platelet aggregation grades were similar in both groups (3.5 +/- 0.5). Postoperatively, at the termination of cardiopulmonary bypass and 90 minutes thereafter, all 10 patients treated with aprotinin revealed normal, unchanged platelet aggregation (grade, 3.5 +/- 0.5), whereas all placebo-treated patients showed severely disturbed aggregation (grade, 1.4 +/- 0.5) (p less than 0.001). The platelet count was similar in both groups before and after operation (preoperatively, 182 +/- 75 x 10(9)/L and 146 +/- 30 x 10(9)/L, and postoperatively, 87 +/- 13 x 10(9)/L and 80 +/- 27 x 10(9)/L for the aprotinin and placebo groups, respectively). Total 24-hour postoperative bleeding and blood requirement were significantly lower in the aprotinin group (371 +/- 84 mL and 2 +/- 0.7 units, respectively) compared with the placebo group (608 +/- 28 mL and 3.4 +/- 1.3 units, respectively) (p less than 0.01). These results demonstrate that improved postoperative hemostasis is directly related to the complete preservation of platelet function achieved by the protective properties of aprotinin.

Fresh blood units contain large potent platelets that improve hemostasis after open heart operations

Twenty units of fresh whole blood were separated into fresh packed red blood cells (PC) and platelet-rich plasma (PRP) and were transfused to 40 patients immediately after coronary bypass grafting. Patients were preoperatively randomized to receive either PRP (group A, 20 patients) or PC (group B, 20 patients). Platelet number in the PRP group was greater, but not significantly greater, than in the PC group (7.5 +/- 3 versus 5.9 +/- 2.2 x 10(10); p = not significant). However, mean platelet volume in the PC group was significantly greater (8.75 +/- 1.1 versus 6 +/- 0.7 fL). Postoperatively, group A patients bled more than group B (566 +/- 164 versus 327 +/- 41 mL; p less than 0.01) and received more red blood cell units (2.7 +/- 1.2 versus 1.6 +/- 0.7 U; p less than 0.05) and a larger number of blood products (5.9 +/- 3.7 versus 2.6 +/- 1.2 U; p less than 0.05). Transfusion of PRP to group A increased platelet count from 128 +/- 20 to 148 +/- 110 x 10(9)/L; however, platelet functions did not improve. Administration of PC to group B increased platelet count from 139 +/- 22 to 156 +/- 23 x 10(9)/L, improved platelet aggregation (with collagen from 33% +/- 20% to 53% +/- 23%, with epinephrine from 36% +/- 24% to 51% +/- 20%; p less than 0.05), and corrected the prolonged bleeding time. The results suggest that the improved hemostasis observed after fresh whole blood administration is related to the large, potent platelets that remained in the PC and were not separated to the PRP during standard platelet concentrate preparation.

Correlation between myocardial ischemia and changes in arterial resistance during coronary artery bypass surgery

The arterial resistometer provides continuous on-line monitoring of changes in arterial resistance. Resistance index (Ri), which bears a direct relationship to systemic vascular resistance (SVR), is defined by the equation Ri = P'/(dP'/dt), where dP'/dt is the peak dP/dt of the arterial waveform, and P' is the pressure at dP'/dt. In 42 patients with unstable angina, changes in Ri were studied at six periods during aortocoronary bypass surgery before tracheal intubation, during tracheal intubation, leg elevation, presternotomy, sternotomy, and dissection of the internal mammary artery. Thirty-four episodes of ischemia (0.1 mV ST segment changes) were observed in 26 patients. All ischemic episodes were associated with increased Ri (mean increase, 102 +/- 52%). Elevation of the pulmonary capillary wedge pressure correlated with ischemia during the preintubation, intubation, and sternotomy periods, but not in the remaining periods. Changes in arterial pressure and heart rate were not good predictors of ischemia. The prevalence of ST segment changes increased markedly during all periods of anesthesia with increase in Ri (P less than 0.05). Ninety-one percent of ST segment changes were associated with a 25% increase from the baseline Ri. Raising the cutoff point to a greater than or equal to 75% increase in Ri improved the specificity of Ri in ischemia detection from 61% to 92%. An increase of greater than or equal to 75% in Ri occurred in only 8% of cases without ST segment changes. It was found that an increase in Ri as depicted by the arterial resistometer was the best hemodynamic correlate of myocardial ischemia.

Left ventricular thrombectomy in the early postinfarction period

Emergency left ventricular thrombectomy was performed on four patients soon after infarction. In three patients surgery was carried out after embolisation had occurred and when a large, residual, protruding, mobile thrombus remained in the left ventricle. Surgery was performed in the fourth patient after a high risk thrombus was detected and initial attempts to lyse it had failed. All four patients had an uneventful recovery and were discharged within two weeks of surgery. These cases indicate that the therapeutic option of left ventricular thrombectomy is feasible for patients with acute infarcts and problematic left ventricular thrombi.

Is transfusion of fresh plasma after cardiac operations indicated?

Patients undergoing cardiac operations constitute the majority of recipients of fresh frozen plasma. In most centers the reason for transfusing fresh frozen plasma is to replace clotting factors. However, the decrease of clotting factors during cardiopulmonary bypass is not sufficient in most patients to cause abnormal bleeding. One of the major causes of nonsurgical bleeding after cardiac operations is acquired platelet dysfunction, which can be corrected by transfusion of 1 unit of fresh whole blood. Because plasmatic factors in fresh whole blood may be responsible for this improvement, a study was designated to evaluate the effect of transfusing fresh plasma on platelet function after cardiac operations. Forty patients undergoing cardiopulmonary bypass were randomized to receive either fresh plasma or the fresh packed cell fraction. Administration of packed cells increased platelet number (118 +/- 8.5 to 154 +/- 7.6 x 10(9)/L, p less than 0.05), shortened bleeding time (7.57 +/- 0.4 to 4.0 +/- 0.3 minutes, p less than 0.05), and improved platelet aggregation in response to collagen and epinephrine (32% +/- 4.7% to 50% +/- 5.6% and 37% +/- 5.8% to 50% +/- 5.8%, respectively, p less than 0.05). Fresh plasma, however, neither increased platelet number nor improved bleeding time or platelet aggregation. Each group later received the remainder of the blood unit, with similar results. The results suggest that improvement of platelet function in patients receiving fresh whole blood after cardiac operations is not related to plasmatic factors. Therefore the massive use of fresh frozen plasma in patients after cardiopulmonary bypass should be reconsidered.

Transfusion of fresh whole blood stored (4 degrees C) for short period fails to improve platelet aggregation on extracellular matrix and clinical hemostasis after cardiopulmonary bypass

It has recently been shown that the hemostatic effect of 1 unit of fresh whole blood is equivalent to the effect of 8 to 10 platelet units. This study was designed to evaluate the effect of short periods of cold (4 degrees C) storage on the hemostatic effect of fresh whole blood transfusion in 36 patients immediately after cardiopulmonary bypass. Twelve patients (group A) received unrefrigerated fresh whole blood, 12 (group B) received fresh whole blood after 5 hours' storage at 4 degrees C, and 12 (group C) after 24 hours' storage at 4 degrees C. For evaluation of platelet function, a method with an extracellular matrix and an electron microscope was used. The platelet function was graded from 1 to 4, with grade 4 being normal aggregation. Postoperatively, group A patients bled less than groups B and C (267 +/- 42 versus 397 +/- 72 and 601 +/- 172 ml/24 hr, respectively, p less than 0.001) and therefore received fewer blood units (1.4 +/- 0.5 versus 2 +/- 0.9 and 3 +/- 1.4, respectively, p less than 0.01). Five patients of group A (42%) reached grade A aggregation after transfusion of unstored fresh whole blood, compared with two (17%) of group B and none (0%) of group C (p less than 0.01). Posttransfusion platelet count and mean platelet volume were not significantly different in the three groups. We conclude that storage at 4 degrees C, even for a short period of 5 hours, diminishes the hemostatic effect of fresh whole blood by decreasing platelet aggregability.

Right ventricular pressure dynamics after operation for pulmonary stenosis

Right ventricular pressure dynamics were monitored during the first 24 hours after operation for relief of pulmonary stenosis in 9 patients with dysplastic pulmonary valves who underwent total valvectomy. Rather than the expected immediate drop in pressure after total removal of the obstruction, right ventricular pressures required 18 to 24 hours to decrease to physiological values. In 7 patients, the pressures decreased steadily, but in 2, there was an increase in pressure immediately postoperatively, followed by a gradual decrease.

Results of operation for hypertrophic obstructive cardiomyopathy in children and adults less than 40 years of age

Forty-seven consecutive patients aged 1-38 years underwent operation for hypertrophic obstructive cardiomyopathy (HOCM) between 1972 and 1986. Isolated myectomy-myotomy was performed in 43 patients, three patients underwent myectomy and concomitant aortic valve repair, and one patient underwent concomitant mitral valve replacement. The peak systolic pressure gradient from the left ventricle to the aorta decreased from 70 +/- 33 mm Hg (mean +/- SEM) preoperatively to 10 +/- 15 mm Hg immediately after repair (p less than 0.001). Moderate or severe mitral insufficiency was identified in 16 patients preoperatively and was corrected by myectomy alone in 15. There was no operative mortality; two late deaths occurred during follow-up (median, 5 years; maximum, 16 years) for estimated 5- and 10-year survivals of 97 +/- 2% and 88 +/- 10%, respectively. Reoperation was required for aortic valve replacement (n = 2), remyectomy (n = 2), and permanent pacemaker implantation (n = 3). Preoperative symptoms were relieved in 24 of 29 (83%) patients with dyspnea, in 18 of 19 (95%) with angina, and in six of 10 (60%) with syncope. These results support myectomy-myotomy for symptomatic children and young adults with HOCM. Also, it appears that late survival after myectomy-myotomy in these young patients may be improved over that observed in historical controls treated with medications alone; operation should be considered for asymptomatic children and adults less than 40 years of age with large (greater than 80 mm Hg) left ventricular outflow gradients.

Assessment of adverse drug events during the clinical investigation of a new drug

Identification and documentation of adverse drug events (ADEs) is an essential prerequisite for the evaluation of the therapeutic value of drug treatment. The present article focuses on the methods used to elicit ADEs during the early drug development phase. These methods vary in the sources of information (patient or physician) used to identify and document ADEs and in the areas (e.g., general scales or special motor performance scales) studied for ADEs.

The outcome of surgical treatment of hypertrophic obstructive cardiomyopathy. Experience over 15 years

From 1972 through 1987, 115 patients between the ages of 1 and 83 years (mean, 44.5 years) underwent operation for hypertrophic obstructive cardiomyopathy. Methods of relief of left ventricular outflow obstruction were septal myectomy/myotomy (n = 109), mitral valve replacement (n = 4), and myectomy/myotomy plus mitral valve replacement (n = 2); concomitant procedures included coronary artery bypass (n = 19) and aortic valve replacement (n = 9). Systolic gradient (peak-to-peak) from the left ventricle to the aorta decreased from 70 +/- 38 mm Hg (mean +/- standard deviation) to 9 +/- 11 mm Hg. There were six hospital deaths, for an overall operative risk of 5.2%; one death occurred among 83 patients less than age 65 years (operative risk, 1.2%), and five deaths occurred in 32 older patients (operative risk, 15.6%; p = 0.008 for difference between age groups). Four (22.2%) of 18 patients with a residual gradient greater than 15 mm Hg died, compared with two (2.1%) of 97 patients with a lower gradient (p = 0.003). Follow-up ranged from 0.5 to 16 years (mean, 5.1 years), and 5-year actuarial survival rate, including hospital deaths, was 84% +/- 4%. The 5-year survival rate was decreased in patients who had operative procedures other than myectomy/myotomy (69% versus 91%, p less than 0.005) and in patients aged 65 years or older (54% versus 93%, p less than 0.005). No correlation was found between preoperative symptoms, functional class, left ventricle-aorta pressure gradient, or mitral valve insufficiency and operative or late mortality. Preoperative symptoms were relieved in 57 (76%) of 75 patients with dyspnea, 49 (83%) of 59 patients with angina, and 22 (96%) of 23 patients with syncope. This experience confirms the effectiveness of operation for relief of symptoms in patients with the obstructive form of hypertrophic cardiomyopathy. The current operative mortality rate is low, especially in patients less than 65 years of age (1.2%). Our experience suggests that incomplete relief of left ventricular outflow obstruction may increase the risk of early postoperative death.

The effect of transfusion of fresh whole blood versus platelet concentrates after cardiac operations. A scanning electron microscope study of platelet aggregation on extracellular matrix

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 hemostatic effect of transfusing fresh whole blood versus platelet concentrates after cardiac operations

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.

Overview of postmarketing experience with ofloxacin in Germany

Clinical trials with ofloxacin have shown that adverse drug events (ADEs) occurred in between 2.4% (Phase II) and 3.1-7.3% (Phase IV) of patients treated and were mostly mild. As with any other drug the true spectrum of rare events can only be fully appreciated after marketing. Since the launch of ofloxacin in June 1985 about 3.5 million patients have been treated in Germany, calculated on the basis of a mean daily dose of 400 mg ofloxacin and a mean duration of treatment of seven days. During these 2.5 years 985 spontaneous national reports of ADEs have been obtained and include rare adverse events (e.g. hallucination, psychotic reaction and shock), not seen in clinical trials. The present status of results from postmarketing surveillance is shown and discussed. The favourable overall risk:benefit ratio of ofloxacin appears unchanged.

The perioperative fate of residual gradients after repair of discrete subaortic stenosis and time-related blood levels of catecholamines

The fate of the residual peak systolic left ventricular-aortic gradient was studied perioperatively in 14 patients with membranous discrete subaortic stenosis. In nine (group A) the initial postrepair left ventricular-aortic gradient was greater than 35 mm Hg (mean 56.8 +/- 13.4), and in five (group B) there was no significant postoperative gradient (mean 15.3 +/- 3.2 mm Hg). The operation included membranectomy and myectomy. Peak left ventricular-aortic pressure gradient, endogenous levels of norepinephrine, peak rate of rise of left ventricular pressure, cardiac index, systemic vascular resistance, heart rate, and central venous pressure were recorded at the end of cardiopulmonary bypass and in 3-hour intervals for the next 9 hours. In group A during that period there was a 67% reduction in peak systolic left ventricular-aortic gradient (from 56.8 +/- 13.4 to 18 +/- 14 mm Hg, p less than 0.001). Concomitant reduction in the initial endogenous norepinephrine level was observed (from 982.1 +/- 181 to 422.6 +/- 109 pg/ml, p less than 0.001). A consistent linear relationship between norepinephrine levels and peak systolic left ventricular-aortic gradient was found (r = 0.78). Systolic left ventricular pressure decreased from 174.2 +/- 24.8 to 113.8 +/- 14.7 mm Hg (p less than 0.001). Marked reduction in peak rate of rise of left ventricular pressure (from 3455 +/- 636 to 2161 +/- 680 mm Hg/sec, p less than 0.001) was observed. Cardiac index increased and systemic vascular resistance decreased during the study period (from 2.11 +/- 0.2 to 3.07 +/- 0.26 L/min, p less than 0.001, and from 2172 +/- 331 to 1233 +/- 202 dynes/sec/cm-5, p less than 0.001, respectively). There were no significant changes in heart rate (p = not significant) and central venous pressure p = not significant).

CONCLUSION

Some of the residual perioperative left ventricular-aortic gradients in patients with discrete subaortic stenosis undergoing repairs are dynamic and transient, and are probably related to increased postoperative sympathetic activity.

Preservation of the posterior leaflet during mechanical valve replacement for ischemic mitral regurgitation and complete myocardial revascularization

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.

Relationship of right and left ventricular negative diastolic pressures, hypercontractility, and relief of outflow tract obstructions

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.

A method for continuous on-line monitoring of systemic vascular resistance (COMS) after open heart procedures

A new method for continuous on-line measurement (COMS) of systemic vascular resistance (SVR) utilizing simple computer analysis of the peripheral arterial waveform is presented. The fundamental equation of this method is: (Formula: see text) where SVR is systemic vascular resistance, dP/dt is the peak dP/dt of the peripheral arterial waveform, and P' is the pressure at the time of peak dP/dt. F and a are calibration constants determined by taking simultaneous measurements by an independent method (thermodilution) before (low SVR) and immediately after (high SVR) aortocoronary bypass operations. In 22 patients 255 COMS of SVR readings were recorded simultaneously with thermodilution cardiac output measurements. Patients were exposed to situations such as temperature changes, volume load, blood loss, and the effect of drugs such as various catecholamines, nitroglycerin, and nitroprusside. Linear regression analysis was performed to compare the SVR calculated from thermodilution with the COMS-SVR measurements. SVR values ranged from 450 to 4400 dynes/sec/-5 and correlation between COMS and thermodilution was r = 0.98. Correlation coefficients of individual patients ranged from r = 0.9 to r = 0.986. We found COMS SVR measurements accurate, reliable, and extremely helpful in the management of hemodynamically unstable patients.

Inaccuracy of radial artery pressure measurement after cardiac operations

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.

Parathyroid sonography: diagnostic accuracy related to shape, location, and texture of the gland

The sonographic features of 51 pathological parathyroid glands detected pre-operatively were analysed. Atypical texture was found in 23.5% and variation in shape in 15.6% of the cases. Cystic parathyroid glands are difficult to differentiate from thyroid cysts, and may be the cause of false positive diagnosis, as in three cases in this series. Topographic assessment showed a relatively low sensitivity in detecting disease in the right upper gland (50%) and in the upper mediastinum (70%). The decreased accuracy in these regions is probably because of the particular anatomical location of the right upper gland and sonographic limitations in screening the mediastinal region. Awareness by the radiologist and surgeon of the variations in texture and location may influence both diagnosis and intraoperative detection of the abnormal parathyroid gland.

Side effects of ofloxacin in clinical trials and in postmarketing surveillance

Data derived from clinical trials of ofloxacin in 15,962 patients show that the incidence rate of adverse drug events was 4.27 per 100 patients. Symptoms were generally mild and related to the gastrointestinal tract, nervous system or hypersensitivity reactions in rank order. On the other hand, spontaneous reports obtained during postmarketing surveillance involving 1.5 million patients showed that the most frequent adverse drug events were related to the nervous system; next in order of frequency were hypersensitivity reactions and gastrointestinal symptoms. A comparison of the data obtained from clinical trials and postmarketing surveillance revealed no change in the favourable overall benefit:risk ratio of ofloxacin. Possible reasons for the different patterns of adverse drug events are discussed.

Platelet size and mass as an indicator for platelet transfusion after cardiopulmonary bypass

Platelet count, mean platelet volume (MPV), and plateletcrit (PCT) were studied in 51 patients after cardiopulmonary bypass (CPB). MPV was significantly lower in 10 patients who developed postoperative bleeding (bleeders) compared to 41 with no significant bleeding (nonbleeders) (7.7 +/- 0.86 vs 8.5 +/- 1.2 fl, p less than .05). Postoperative platelet count was significantly lower in the group of bleeders (93.3 +/- 22.4 vs 127.5 +/- 43 X 10(9)/liters, p less than .02). A cutoff point of MPV or platelet count that would include bleeders and exclude nonbleeders could not be found due to the large overlap between the two groups. However, such a cutoff point does exist for PCT (PCT = total platelet mass). PCT was significantly lower among the bleeders (0.072 +/- 0.02% vs 0.108 +/- 0.036%, p less than .05) and a cutoff point of PCT less than 0.1% included all the bleeders and excluded 65% of nonbleeders. The low PCT and bleeding tendency can be corrected by platelets transfusion. In 15 patients (eight bleeders and seven nonbleeders) with low postoperative PCT (0.078 +/- 0.014), transfusion of 10 platelet units increased platelet count from 101 +/- 32 to 169 +/- 22 X 10(9)/liter, increased PCT to 0.128 +/- 0.2%, and stopped bleeding in all bleeders. A finding of PCT less than 0.1% after CPB is a clear indication for platelet transfusion in patients who develop post-CPB bleeding. This supports the observation that large platelets are more active than smaller ones, and that PCT, rather than PLT counts, predicts the risk of bleeding in patients with thrombocytopenia.

Changes in systemic vascular resistance detected by the arterial resistometer: preliminary report of a new method tested during percutaneous transluminal coronary angioplasty

A recently developed apparatus provides on-line continuous monitoring of systemic vascular resistance (SVR) by means of simple computer analysis of the peripheral arterial waveform. The fundamental equation of this method is Ri = P'/(dP/dt), where dP/dt is the peak dP/dt of the peripheral arterial waveform, P' is the pressure at time of peak dP/dt, and Ri is a resistance index that bears a direct relation to SVR. Eleven patients undergoing percutaneous transluminal coronary angioplasty (PTCA) were studied to evaluate the changes in SVR associated with myocardial ischemia (angina detection). There were 49 balloon inflations, all of which were associated with an increase in Ri (from 38.4 +/- 12 to 81.2 +/- 36 X 10(-3) sec; p less than .01) and a decrease in dP/dt (from 2076 +/- 257 to 1327 +/- 326 mm Hg/sec; p less than .01). In 42 of the balloon inflations these changes were associated with electrocardiographic ST-T changes and in 23 it was also associated with anginal pain. When angina was present, a further increase in Ri (to 97.5 +/- 43 X 10(-3) sec; p less than .01) and a decrease in dP/dt (to 1218 +/- 338 mm Hg/sec; p less than .01) was observed. It was found that myocardial ischemia is associated with an increase in the resistance index and a decrease in dP/dt and can be detected by the resistometer.

Effect of cardiac operation on platelets

The effect of extracorporeal circulation on platelet count and size (mean platelet volume) was studied in 65 patients (nine bleeders and 56 nonbleeders). In addition to the above, in 20 of the patients platelet aggregation response to adenosine diphosphate, collagen, and ristocetin was measured. Platelet counts dropped postoperatively both in the bleeder and in the nonbleeder groups. The difference between them was not significant. However, the bleeders had a significantly lower mean platelet volume (7.7 +/- 0.84 versus 8.68 +/- 1.1 fl) and lower volume percentage of platelets in whole blood (0.075% +/- 0.02% versus 0.116% +/- 0.04%) (p less than 0.05) than the nonbleeders. None of the bleeders had a volume percentage of platelets in whole blood higher than 0.095%. All 20 patients studied for platelet functions had an abnormal postoperative aggregation response to adenosine diphosphate, collagen, and ristocetin. Three patterns of disturbed response to ristocetin were observed: grade I, delayed onset (14 patients); grade II, incomplete aggregation (five patients); and grade III, total lack of aggregation (one patient). All patients with delayed-onset response to ristocetin had a normal bleeding time, whereas the six patients with grade II and III responses had prolonged bleeding times and three of them had clinically significant bleeding. Factor VIII procoagulant activity, factor VIII-related antigen, factor VIII-ristocetin cofactor, and factor VIII two-dimensional electrophoresis were found normal, which suggests that the von Willebrand-like reaction to ristocetin observed in this study was caused by a defect in platelet membrane rather than by factor VIII changes.

Negative right ventricular diastolic pressure after operation for pulmonary valve stenosis: the phenomenon and its relation to volume load and conal contraction

The phenomenon of negative right ventricular diastolic pressure immediately after operation for relief of isolated pulmonary valve stenosis was investigated in 11 patients. Pressures in the right ventricle and pulmonary artery were measured with a catheter tip micromanometer. One patient had a negative right ventricular diastolic pressure before operation. At the end of operation right ventricular diastolic pressure was negative in all 11 patients. The greater the right ventricular hypertrophy, the lower were these diastolic pressures. Negative right ventricular diastolic pressure is thus common in patients after pulmonary valvotomy, but fluid administration may eliminate it. Negative right ventricular diastolic pressure may be the result of hypercontraction and reduced volume of the hypertrophied right ventricle after relief of right ventricular outflow tract obstruction.

Speech rehabilitation outcome after Blom-Singer tracheoesophageal puncture

This study evaluated speech rehabilitation outcome and length of training needed for laryngectomized patients who underwent the Blom-Singer tracheoesophageal (TE) puncture procedure. Preoperative patient selection criteria included: 1) acceptable stoma size, 2) adequate motivation and manual dexterity, 3) absence of constrictor spasm. Training focused on coordination of breath control, articulation, muscle relaxation, and proper handling and maintenance of the "duckbill" prosthesis. Speech intelligibility in 12 patients was evaluated following the completion of their speech rehabilitation program, using the CID Everyday Sentences. Each patient was videotaped; the tape then was presented to unbiased listeners who recorded the sentences. The median percentage of intelligibility for the 12 patients was 89.5%; only one patient had a median score less than 60%. The mean length of formal training for the group was only 3.2 hours (range 1 to 7 hours). The percentage of patients attaining speech and the quality of their speech intelligibility was found to be higher than with esophageal speech, which is both time consuming and often difficult to learn. TE puncture followed by proper fitting and training in voice prosthesis usage improves speech rehabilitation outcome for the laryngectomized patient.