Does flow character of cardiopulmonary bypass make a difference?

The influence of pulsatile bypass flow on the performance of the cardiovascular system, fluids and blood balance, acid-base equilibrium, and splanchnic function was investigated. One hundred patients scheduled for elective coronary artery bypass grafting were randomly divided into a group of standard perfusion (NP) and a group of pulsatile perfusion (PP). At the end of the operation, similar cardiac performance developed in both groups that was higher than before bypass: left ventricular stroke work index after bypass, 56.8 +/- 2.7 gm/beat per square meter in the NP group and 56.7 +/- 2.6 gm/beat per square meter in the PP group (not significant). Further determinations did not differ among the groups. After discontinuation of cardiopulmonary bypass, bypass grafts flow measured using an electromagnetic probe did not differ among the groups. During the postbypass period, mean arterial pressure and systemic vascular resistance were similar (mean arterial pressure 86.8 +/- 1.6 mm Hg in the NP group and 88.5 +/- 1.7 in the PP group; systemic vascular resistance 817 +/- 33 dyne.sec/cm5 in the NP group and 881 +/- 34.5 in the PP group), as were further determinations. However, severe hypotension requiring the administration of vasoconstrictors was observed more frequently in PP group of patients (20 versus 6%; p < 0.05). Fluid balance determined at the second postoperative day was similar among the groups (+1307 +/- 239 ml in the NP group and +1535 +/- 266 ml in the PP group). Blood loss was 1122 +/- 120 ml in the NP group and 1263 +/- 119 ml in the PP group during the first postoperative day (p = 0.407). Urine output during bypass was lower in the PP group (261 +/- 25 versus 341 +/- 26 ml/hr; p = 0.028). The creatinine clearance was 96.4 +/- 10.3 ml/min in the NP group and 92.6 +/- 7.0 ml/min in the PP group (not significant); amylase and lipase clearance did not differ among the groups. Finally, no significant difference was detected in arterial lactic acid determinations and acid-base balance assessment between the groups postoperatively. Thus equivalent cardiovascular hemodynamics, a good control of fluids and blood balance, acid-base equilibrium, and a satisfactory protection of the function of kidneys and pancreas were obtained with both types of perfusion.

Intraoperative hemodynamic assessment of gastroepiploic artery and saphenous vein bypass grafts: a comparative study.

OBJECTIVE: Blood flow characteristics of right gastroepiploic artery and saphenous vein conduits were compared during bypass surgery. METHODS: This study is based on a consecutive series of 97 patients undergoing a bypass graft to the right coronary artery, posterior descending artery, or posterolateral branch using either a pediculated right gastroepiploic artery (n = 52) or a saphenous vein (n = 45) bypass graft. Flows and velocity profiles were measured with an 8-MHz pulsed-wave Doppler ultrasound flowmeter. Thorough flow measurements were made (1) after cessation of cardiopulmonary bypass and (2) before chest closure. RESULTS: At the end of cardiopulmonary bypass, flow in the right gastroepiploic artery (59. 0 +/- 6.7 mL/min) did not differ (P =.08) from flow in the saphenous vein (46.1 +/- 2.7 mL/min). Mean trace velocity was 11.9 +/- 0.7 cm/s in the right gastroepiploic artery and 11.6 +/- 0.8 cm/s in the saphenous vein (P =.80), but peak systolic velocity was 29.4 +/- 1.2 cm/s for the right gastroepiploic artery and 23.1 +/- 1.3 cm/s for the saphenous vein (P <.001). Likewise, before chest closure, flow was 57.1 +/- 4.7 mL/min in the right gastroepiploic artery and 46.5 +/- 4.0 mL/min in the saphenous vein (P =.10), mean velocity was 12. 9 +/- 0.7 and 11.6 +/- 0.8 cm/s, respectively (P = .22), and systolic peak velocity was 30.0 +/- 1.2 and 22.3 +/- 1.2 cm/s, respectively (P < .001). CONCLUSIONS: There were no flow differences between right gastroepiploic artery and saphenous vein grafts implanted into the same coronary bed in comparable groups of patients. Waveform shape of the right gastroepiploic artery grafts was characterized by a wider spectral dispersion resulting in a higher maximal frequency.

Coronary bypass with both internal mammary and inferior epigastric arteries.

A patient having undergone triple coronary artery bypass grafting with the left internal mammary artery and both shorter saphenous veins was reoperated on because of occlusion of the venous grafts. As there was no other vascular substitute available, the right internal mammary artery and both inferior epigastric arteries were used to achieve myocardial revascularization. This case demonstrates that bilateral internal mammary arteries and inferior epigastric arteries can be used safely.

Intraoperative electromagnetic flowmeter measurements in coronary artery bypass grafts.

This study attempts to relate flow findings in internal mammary (IMA) and saphenous vein coronary artery bypass grafts to postoperative outcome. From 262 patients undergoing coronary artery bypass grafting, 601 electromagnetic flow measurements were obtained in IMA and saphenous vein grafts, and free graft flow was measured in 227 IMAs prior to grafting. Retrograde flushing of the IMA with diluted papaverine hydrochloride resulted in a marked increase in IMA free flow (124 +/- 4 mL/min versus 66 +/- 5 mL/min; p < 0.001). However, IMA free flow did not correlate with electromagnetic flow measurements after grafting to the left anterior descending coronary artery. The use of IMAs with free flows lower than 50 mL/min did not affect clinical outcome. Flow measured in saphenous vein grafts (66 +/- 9 mL/min) with an electromagnetic flowmeter was significantly greater (p < 0.001) than that in the IMA grafted on the left anterior descending coronary artery (36 +/- 3 mL/min) under comparable hemodynamic conditions. For the purpose of data analysis, patients were separated into three groups based on increasing incidence of complications: levels 0, 1, and 2. Patients with an uneventful outcome had a mean graft flow at chest closure of 51 +/- 3 mL/min versus 51 +/- 4 mL/min for patients in complication level 1 and 45 +/- 11 mL/min for patients in complication level 2 (p = not significant). Free flow measured in a vasodilated IMA was a poor predictor of flow into a grafted IMA and did not affect clinical outcome. We were unable to validate any flow limit to use of the IMA.(ABSTRACT TRUNCATED AT 250 WORDS)

Treatment of incessant reciprocating atrioventricular tachycardia by a closed heart surgical technique.

The case of a 40-year-old woman having disabling symptoms of incessant atrioventricular reciprocating tachycardia is reported. She underwent surgical therapy by a closed heart technique. Operative technique and the advantages of the epicardial approach in the present case are detailed.

Closed heart cryoablation of the His bundle using an anterior septal approach.

His bundle cryosurgical ablation using a closed heart anterior septal approach was used in 6 patients. There were 3 men and 3 women, aged 24 to 73 years. Three patients had atrial fibrillation and 2 patients had atrial flutter (2 with combined episodes of atrial tachycardia). One patient had atrial tachycardia. Five patients had no structural heart disease and 1 patient had left ventricular dilatation (ejection fraction, 0.35). All patients undergoing His bundle cryosurgical ablation had permanent heart block without intraoperative complications (mean follow-up, 25 months). Closed heart anteroseptal cryoablation of the His bundle is effective and is an alternative to attempted catheter ablation.

Unusual pitfall of use of retrograde cardioplegia.

The use of retrograde cardioplegia can lead to several complications, mainly related to injuries during the cannulation of the coronary sinus. We herein present a case report of injury to the right coronary artery related to kinking due to the pursestring on the right atrium.

Right internal mammary artery extended with an inferior epigastric artery for circumflex and right coronary bypass.

The right in situ internal mammary artery extended end to end with a free inferior epigastric artery was used through the transverse sinus for sequential grafting to one marginal branch of the circumflex artery and one or both distal branches of the right coronary artery. This procedure was applied in 5 patients with three-vessel disease who received in addition a left in situ internal mammary artery as a sequential graft to the left anterior descending coronary artery and one of its diagonal branches. The postoperative course was uneventful in all cases. A postoperative coronary angiogram obtained on day 10 in 4 patients showed all the grafts and anastomoses patent.

Mitral valve Carpentier-Edwards bioprosthetic replacement, thromboembolism, and anticoagulants.

Patients undergoing mitral valve replacement (MVR) using a bioprosthesis are frequently placed on long-term anticoagulant treatment, and thereby lose the main advantage conferred by the bioprosthesis. To assess predictive factors of the need for long-term anticoagulant treatment, 100 consecutive patients surviving bioprosthetic MVR between 1977 and 1987 were followed up. The estimated thromboembolism-free survival was 88.9% +/- 3.6% after 6 years of follow-up. Preoperative risk factors for thromboembolism were supraventricular arrhythmia (p = 0.013) and a history of thromboembolism (p = 0.039). Among the preoperative and postoperative factors, only postoperative rhythm significantly influenced (p = 0.007) the thromboembolism-free survival, as determined by Cox regression analysis. Permanent anticoagulant treatment was instituted in 39 patients. Preoperative and peroperative risk factors associated with the need for long-term anticoagulant treatment, as evidenced by Fisher linear discriminant analysis, were supraventricular arrhythmia (p < 0.001), septal myotomy (p = 0.013), and predominant mitral stenosis (p = 0.013). Thus, in those patients with predominant mitral stenosis and supraventricular arrhythmia preoperatively, the subsequent need for permanent postoperative anticoagulant treatment is high, and the implantation of a mechanical valve is therefore recommended, providing there are no strict contraindications to anticoagulant treatment.

Intraoperative assessment of coronary artery bypass grafts using a pulsed Doppler flowmeter.

A pulsed Doppler flowmeter was used in a series of 352 consecutive patients undergoing isolated coronary artery bypass grafting. Doppler flow measurements were available on 909 single terminolateral bypass grafts (327 internal mammary arteries and 582 saphenous veins) and 58 sequential bypass grafts anastomosed to combinations of arteries. Flow (mL/min) categorized as a function of the recipient artery was distributed as follows: left anterior descending coronary artery, 69.9 +/- 2.5; right coronary artery, 68.0 +/- 5.0; diagonals, 61.0 +/- 4.1; obtuse marginals, 55.9 +/- 2.2; and posterior descending coronary artery, 53.3 +/- 3.0 (p < 0.001). Graft outflow obstruction resulting from torsion of the graft pedicle or anastomotic stricture was identified in 7 patients (2%). After graft revision, flow increased from 9 +/- 4 mL/min to 69 +/- 13 mL/min (p = 0.023), and velocity rose from 4.6 +/- 1.1 cm/s to 18.1 +/- 2.4 cm/s (p = 0.009). In conclusion, the system was adequate for operative use and allowed identification and correction of technical errors.

Assessment of continuous cold blood cardioplegia in coronary artery bypass grafting.

BACKGROUND: A method of cold blood cardioplegia (CBCP) delivered continuously and in a retrograde manner was compared with methods differing only by their rate (intermittent) or way (antegrade) of administration. METHODS: This study comprises 298 consecutive patients undergoing isolated coronary artery bypass grafting procedures performed by the same surgeon from 1992 to 1995. Three-vessel disease characterized 58.8% of the cases, and the left ventricular ejection fraction was less than 0.40 in 22.8%. In group I (n = 100), CBCP was administered in an antegrade and intermittent fashion; in group II (n = 87), CBCP was given in a retrograde and intermittent manner; in group III (n = 111), CBCP delivery was retrograde and continuous. RESULTS: The incidence of major cardiac adverse outcome (death or need for intraaortic balloon counterpulsation) was 7.0% in group I, 8.0% in group II, and 0.9% in group III (p = 0.040). Repeated-measures analysis of hemodynamic indices showed a marked superiority of continuous retrograde compared with antegrade intermittent blood cardioplegia regarding left ventricular stroke work index (p < 10(-4)) and compared with both methods of intermittent CBCP regarding right ventricular stroke work index (p < 10(-5)). CONCLUSIONS: The use of continuous CBCP resulted in a significant reduction in major cardiac events, better left ventricular performance, and a marked improvement of right ventricular function in comparison with similar solutions of blood cardioplegia administered intermittently, independent of their way of delivery.

Initial experience with low-potassium cold blood cardioplegia: a clinical comparative study.

This study presents the results of bypass grafting in 96 patients operated on for triple-vessel coronary artery disease between May 1988 and September 1990. In the first 54 patients a cold crystalloid solution was employed, and in the 42 more recent patients cold blood low-potassium cardioplegia was employed. There were no differences in postoperative cardiac index or left ventricular stroke work index. Yet, in patients with impaired prebypass left ventricular stroke work index, postbypass left ventricular performance correlated negatively with duration of aortic cross-clamping in the cold crystalloid group (r = -0.441, p = 0.045). In contrast, no correlation was found in the cold blood low-potassium group (r = 0.125, p = 0.587). The incidence of myocardial infarction, need for inotropic support, and need for intraaortic balloon counterpulsation were similar among the groups. Release of the myocardial isoenzyme creatine kinase-MB from 12 to 30 hours after operation was significantly less in the low-potassium blood cardioplegia group. The use of low-potassium blood cardioplegia resulted in a marked reduction in the operative administration of fluids (1,527 +/- 87 versus 3,511 +/- 148 mL; p less than 0.001). In conclusion, low-potassium cold blood cardioplegia is a simple and effective method of myocardial protection. The fact that left ventricular stroke work index recovery was not dependent on the duration of aortic occlusion and that release of the MB isoenzyme of creatine kinase was reduced in the low-potassium blood cardioplegia group implies better myocardial protection.

Operation for unstable angina pectoris: factors influencing adverse in-hospital outcome.

Coronary artery bypass grafting for the treatment of unstable angina is still associated with increased operative risk and postoperative morbidity. The impact of the extended use of arterial grafts on early results is incompletely defined. In a 7-year period (1986 to 1993), 474 patients (average age, 65 years; range, 34 to 85 years) underwent coronary artery bypass grafting for the treatment of unstable angina. Sixty-eight patients were operated on emergently and 406 urgently. They received an average of 3.0 distal anastomoses (range, 1 to 6). Seventy-nine patients had exclusively venous grafts, 316 had one internal thoracic artery graft, 79 had bilateral internal thoracic artery grafts, and 20 had inferior epigastric artery grafts. Sequential internal thoracic artery grafting was performed in 70 patients. Redo operations were performed in 26 patients. Thirty-four patients (7.2%) experienced a new myocardial infarction. Eighty-nine patients (18.8%) had an intraaortic balloon pump inserted preoperatively, intraoperatively, or postoperatively. Eight patients (1.7%) died intraoperatively and 24 patients (5.1%) died postoperatively. Seventy-seven patients (16.2%) had an adverse outcome, as shown by the need for an intraaortic balloon pump (intraoperatively or postoperatively) or hospital death, or by both. Forty variables were examined by multivariate analysis for their influence on the occurrence of an adverse outcome. Aortic cross-clamp time (p = 0.0004), transfer from the intensive care unit (p = 0.0023), female sex (p = 0.0023), operation performed in early years (p = 0.0041), left ventricular aneurysm (p = 0.0068), the number of diseased coronary vessels (p = 0.0312), and reoperation (p = 0.0318) were all found to be significant independent predictors of increased risk.(ABSTRACT TRUNCATED AT 250 WORDS)

Pulsed Doppler intraoperative flow assessment and midterm coronary graft patency.

BACKGROUND: This study was designed to assess the value of hemodynamic measurements taken intraoperatively in predicting midterm patency of coronary bypass grafts. METHODS: A pulsed Doppler flowmeter was routinely used during operation to determine the hemodynamic parameters of coronary bypass grafts. During a 7-year period, 85 patients underwent angiographic evaluation. As a result, a thorough hemodynamic assessment of 214 grafts (89 arterial and 125 venous) at initial operation was available for analysis. RESULTS: The overall patency rate was 88.3%. The mean flow measured intraoperatively in 168 intact grafts was 60+/-3 mL/min (range, 9 to 230 mL/min), and the resistance was 1.8+/-0.1 peripheral resistance units (range, 0.3 to 9.0 peripheral resistance units). The mean flow was 36+/-5 mL/min (range, 2 to 107 mL/min), and the resistance was 5.9+/-2.0 peripheral resistance units (range, 0.6 to 46.0 peripheral resistance units) in 25 grafts found occluded at angiographic evaluation. Multivariate analysis identified three independent variables associated with a reduced patency rate: increased resistance as measured in the graft (p = 0.012), increasing interval of control angiography (p = 0.006), and preoperative cardiogenic shock (p = 0.040). CONCLUSIONS: The prognosis for midterm patency of aortocoronary bypass grafts depends on the intraoperative hemodynamic status.

Viability of long-term cryopreserved human saphenous veins.

The feasibility of maintaining long-term viability of human venous allografts by cryopreservation has been investigated. Segments of vein were obtained from 85 patients undergoing a stripping operation for varicose veins. The venous segments were immersed in a dimethylsulfoxide 15% solution, deep frozen at -196 degrees C in liquid nitrogen and preserved for a duration of 1 week to 24 months. Light microscopy (n = 126) failed to demonstrate striking differences between control veins and any of the cryopreserved veins. The types of damage observed at scanning electron microscopy included endothelial cell separation, endothelial cell loss, exposed basement membrane and exposed fibrillar collagen, which were graded on a scale. The score for short term (less than 3 weeks) stored veins was 8.1 +/- 0.9 (mean +/- SEM) and did not differ from the long-term (greater than 10 weeks) stored veins score (6.3 +/- 1.0, p NS). The tissue enzymes LDH, GOT, GPT, CPK were measured in the frozen vein groups (n = 115) after thawing to room temperature. Cryopreservation did not alter any of the tissue enzymes measured when compared to controls. Endothelial fibrinolytic activity (FA) of 58 venous segments cryopreserved for a mean duration of 20 months was 6136.4 +/- 292.1 Tissue Activator Units (TAU) and did not differ from FA of 11 controls (5989.1 +/- 696.8 TAU). Synthesis of 6-Keto-PGF1-alpha-2, a stable breakdown product of PGI2, measured in 10 venous segments cryopreserved for 10 months, was significantly higher than in 13 veins stored in saline for 12 hours at 4 degrees C (2.8 +/- 0.4 vs 0.4 +/- 0.1 PG ml-1mg-1min-1, respectively; p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Off-pump myocardial revascularization for left main stem disease in a high-risk patient.

Off-pump complete myocardial revascularization for three-vessel disease is often limited by the difficulty to approach the obtuse marginal branches. A method of coronary artery bypass grafting without cardiopulmonary bypass used in a high risk patient with left main stem and three-vessel disease is described.

Scheduling of elective surgical cases within allocated block-times: can the future be drawn from the experience of the past?

UNLABELLED: We determined a strategy to regulate the elective occupation of operating rooms; it was based on the determination of a median operating room occupation time, per procedure and per operator. METHODS: Median occupation times were determined from a retrospective analysis of 12 consecutive months of operating activity (966 patients). These data were prospectively used in surgical planning, with a daily occupation limit set at 10 hours. After four months collecting data, daily recorded (ROT) and predicted (POT) occupation times were compared. The surgical activity during that test period (group A) was compared to the activity of the same period in the previous year (group B) and the evolution of the waiting lists for surgery were analysed for each of the operators. RESULTS: At the end of the four-month observation period, 317 surgical cases spread over 105 operating days were recorded. The correlation between ROT and POT was strong (r = 0.911, p < 0.001). The relative error in this prediction was 13 +/- 11 min. In comparison with group B, group A was characterized by a significant reduction in occurrence (p = 0.015) and duration (p = 0.007) of time limit overruns and in variability of daily occupation time (p < 0.001). The waiting list was reduced for all operators at the end of the test period. CONCLUSION: Determination of individualized median occupation times, associated with definition of a daily limit, resulted in reduction of time overruns and delays before surgery.

Horseshoe kidney and abdominal aortic aneurysm.

Three cases of horseshoe kidney associated with an abdominal aortic aneurysm are reported. The pathology, diagnosis and management are discussed. The review of the literature indicates that successful treatment depends on an accurate knowledge of the blood supply to the kidney.

Infected abdominal aortic aneurysm associated with a psoas abscess, aorto-duodenal and sigmoid fistulas. Case report and review of the literature.

A case of atherosclerotic abdominal aortic aneurysm, complicated by aortoenteric fistulizations and infected by Escherichia coli, is presented. Chronic contained rupture resulted in the formation of a huge left psoas abscess which was responsible for the symptoms. No similar case has been reported in the literature. Resection and extra-anatomic vascular reconstruction were curative.

Persistent left superior vena cava: transoesophageal echocardiographic findings and surgical strategies.

Two cases of casual discovery of persistent left superior vena cava during cardiac surgery are reported. Diagnoses were suspected at the time of peroperative transoesophageal echocardiography in the first case, and of preoperative fluoroscopy during a Swan-Ganz catheter insertion procedure in the second case. For both patients, a peroperative echo contrast study permitted to confirm the anomaly before initialization of cardiopulmonary bypass. Embryology, echocardiographic findings and surgical management, including cardioplegia delivering and left upper venous system drainage, are reviewed.