[Oxygen consumption during cardiovascular surgery conducted under extra-corporeal circulation]

Whole-body oxygen consumption (VO2) is universally considered both a measure of the metabolic activity of the body and an indicator of the adequacy of tissue perfusion during cardiopulmonary bypass as well. There is little agreement in the literature about the main determinants of oxygen consumption during CPB, except for the role of temperature in reducing the metabolic activity of the body. Many studies, which have been performed both on animals and in humans, have reached some contradictory conclusions about the role of delivery and perfusion flow rates, of haemodynamic variables, of the acid-base status, and of drugs influencing the variations of oxygen consumption during CPB. Aim of this paper is to review the evidences in literature about the determinants of whole-body oxygen consumption during cardiopulmonary bypass in man.

Hypertonicity induces injury to cultured human endothelium: attenuation by glutamine

BACKGROUND

Although most preservation solutions as well as some cardioplegic solutions used for organ storage and transplantation are hypertonic, the effects of extracellular hypertonicity on endothelium are not well established. Aims of this study were to evaluate the response of cultured human saphenous vein endothelial cells to extracellular hypertonicity and to investigate the role of the amino acid glutamine in preventing endothelial damage in vitro.

METHODS

Eight distinct strains of human saphenous vein endothelial cells were studied. Hypertonic (350 and 400 mosm/kg) media were obtained by supplementing culture medium with sucrose. Cell viability was assessed in the absence or the presence of glutamine through the determination of cell number and protein content of the cultures. Confocal microscopy of cells loaded with the fluorescent dye calcein was also performed.

RESULTS

Exposure of human saphenous vein endothelial cells to hypertonic media without glutamine caused significant cell loss within 30 minutes. Cell loss progressed steadily during incubation and after 6 hours reached 50% at 350 mosm/kg and 65% at 400 mosm/kg. In the presence of 2 mmol/L glutamine, endothelial damage was completely prevented at 350 mosm/kg and significantly lessened at 400 mosm/kg compared with glutamine-free media. Confocal microscopy showed that most hypertonicity-treated cells exhibited the typical features of an apoptotic death and confirmed the osmoprotective effect of glutamine.

CONCLUSIONS

These results indicate that the supplementation of hypertonic storage solutions with glutamine might exert a partial osmoprotective effect and suggest that the relationship between endothelial damage and tonicity of storage and cardioplegic solutions should be carefully investigated.

[Surgery of the ascending aorta: the 1984-1995 experience of the cardiac surgery teaching unit in the University of Milan. Multivariate analysis of its risk factors for hospital mortality and reduced long-term survival]

Between 1984 and 1995, 183 patients underwent an ascending aorta procedure at our institution. Their mean age was 60 +/- 12.3 years; 116 (63.4%) patients were male, 35 (19.1%) had a history of congestive heart failure, 72 (39.3%) presented acute type A dissection, 23 (12.6%) were redos and 63 (34.4%) were operated on an emergency basis. In-hospital mortality was 10% (12/120) in elective procedures and 36.5% (23/63) in emergency operations (p < 0.0001). Multivariate stepwise logistic regression analysis identified cardiopulmonary by-pass time, emergency operation, arch replacement and the need for femoral vein cannulation at surgery as independent predictors of in-hospital death. Mean follow-up time was 54 +/- 30 months (median 50 months), with a Kaplan-Meier survival of 69 +/- 4% and of 60 +/- 5% at 5 and 7 years, respectively. Cox regression analysis identified arch replacement, perioperative myocardial infarction, preoperative NYHA class, acute type A aortic dissection, the need for femoral vein cannulation at intervention and redo operations as independent predictors of reduced survival at follow-up. When this kind of analysis was performed on hospital survivors only, postoperative tracheostomy, reexploration for bleeding, and the occurrence of postoperative ventricular arrhythmias emerged as risk factors. In conclusion, multiple factors affect both early and long-term outcome following ascending aorta surgery. Preoperative clinical status of patients, priority of surgery and aortic dissection are the main determinants of the short-term results. Otherwise, in hospital survivors, the main determinant for long-term outcome seems to be the immediate postoperative course.

Early and late results of ascending aorta surgery: risk factors for early and late outcome

This study was designed to evaluate risk factors for in-hospital mortality and midterm survival in patients undergoing ascending aorta surgery at a single institution during an 11-year period. Between 1984 and 1994 a total of 158 patients underwent an ascending aorta procedure at our institution. Their mean age was 59.6 +/- 12.3; 115 (73%) were male, 33 (21%) had a history of congestive heart failure, 61 (39%) had an acute type A dissection, 21 (13%) underwent redo operations, and 55 (35%) were operated on an emergency basis. In-hospital mortality was 9.7% (10/103) for elective procedures and 36.4% (20/55) for emergency operations (p < 0.0001). Multivariable stepwise logistic regression analysis identified the cardiopulmonary bypass time [odds ratio (OR) = 1.01/min, p = 0.0021], emergency operation (OR = 2.27, p = 0.0022), arch replacement (OR = 2.71, p = 0.0067), and the need of femoral vein cannulation at intervention (OR = 1.89, p = 0.0375) as independent predictors of in-hospital death. When this kind of analysis was performed, evaluating only the variables known before surgery, acute type A dissection (OR = 2.21, p = 0.0009) and preoperative NYHA class (OR = 1.88 per class, p = 0.0290) were independent risk factors for in-hospital death. Follow-up ranged from 10 to 126 months (median 42 months), with Kaplan-Meier survivals of 69 +/- 4%, and 60 +/- 5% at 5 and 7 years, respectively; survival rates for hospital survivors were 85 +/- 4% and 67 +/- 7% at 5 and 7 years, respectively. Cox regression analysis has identified arch replacement [relative risk (RR) = 2.48, p < 0.0001], perioperative myocardial infarction (RR = 2.44, p = 0.0003), preoperative NYHA class (RR = 1.97 per class, p = 0.0009), acute type A aortic dissection (RR = 1.44, p = 0.0238), the need of femoral vein cannulation at intervention (RR = 1.55, p = 0.0332), and redo operation (RR = 1.44, p = 0.0851) as independent predictors of reduced survival at follow-up. When this kind of analysis was performed on hospital survivors only, postoperative tracheostomy (p = 0.0003, RR = 3.42), reexploration for bleeding (p = 0.0003, RR = 3.77), and the occurrence of postoperative ventricular arrhythmias (p = 0.0007, RR = 2.45) emerged as risk factors. Multiple factors affect the early and late outcome after ascending aorta surgery; our data suggest that the preoperative clinical status of the patients and the priority of surgery and aortic dissection are the main determinants of the early results; on the other hand, the early postoperative course is the main determinant of the late outcome of hospital survivors.

Non-invasive evaluation of right gastroepiploic artery with colour Doppler echography

The right gastroepiploic artery has been increasingly used as a coronary bypass graft. Short- and mid-term patency rates support the supposition that the right gastroepiploic artery is a satisfactory bypass conduit. However, conclusive angiographic data on long-term patency rates are still lacking. An echo-colour Doppler method was used to detect patency of the right gastroepiploic artery grafts through an upper abdominal approach. A group of 24 patients with a right gastroepiploic artery graft to the right or posterior descending coronary artery, all of whom also had a postoperative angiographic study which showed 100% patency of the graft were used as a reference group. A second group of 89 patients was also investigated only with echo-colour Doppler during the postoperative period (mean 8.0 (range 1-48) months). A patent right gastroepiploic artery graft showed a biphasic velocity pattern. Systolic peak velocity ranged from 8 to 26 cm and diastolic peak velocity from 4 to 13 cm. The right gastroepiploic artery diameter ranged from 1.7 to 2.4 mm and flow from 10.2 to 58.8 ml. Among the second group were three patients who had, at their echo-colour Doppler examination, a possible occlusion of the right gastroepiploic artery graft; an angiographic study was conducted and the graft closure confirmed in all cases. Serial echo-colour Doppler evaluation of the right gastroepiploic artery blood flow pattern and diameter is a non-invasive and safe method to check the patency and flow capacity of the artery graft in follow-up studies.

[Surgical therapy for prosthetic infections of the thoracic aorta. Conservative approach]

The prosthetic graft infection of the thoracic aorta is a dreaded complication and it is associated with a high mortality rate. There is not substantial agreement in literature about how to manage a vascular graft infection, except for local anti-septic irrigation with a systemic antibiotic therapy. The main point of discussion is if it is mandatory to remove or not the infected thoracic aorta prosthesis: some authors prefer to eliminate all the thoracic aortic prostheses which may be infected, while others propose graft removal only when the sutures lines are involved. In this paper we report our experience on the conservative management of infected thoracic aorta prostheses using a local antiseptic irrigation, a perigraft debridement and leaving the original graft "in situ" when there is evidence of graft damage especially or involvement of the sutures lines. This approach has been performed in three patients: two had an infected aortic arch prosthesis, while one had a descending thoracic aorta prosthesis infection.

Surgery of descending thoracic aortic aneurysms with centrifugal pump support

Fifty-five patients with descending thoracic aortic aneurysms were operated upon between October 1987 and October 1994. All patients were supported by a centrifugal pump during operation. The mean(s.d.) duration of cross-clamping was 39(13) min. In order to evaluate the efficacy of the centrifugal pump, haemodynamic and metabolic measurements were made on four occasions (before cross-clamping, immediately after cross-clamping and before cross-clamp removal) and again after cross-clamp removal. The haemodynamic data remained stable throughout the procedure: central venous pressure (15(4.6) versus 16(4.8) versus 16(4.6) versus 15(4.6) mmHg; P = n.s.), pulmonary artery pressure (25(6.2) versus 24(5.1) versus 22(5.3) versus 23(4.4) mmHg; P = n.s.), radial systolic pressure (119(19.9) versus 116(25.2) versus 111(25.9) versus 111(20.7) mmHg; P = n.s.) and heart rate (75(12.6) versus 77(14) versus 76(15.6) versus 78(16) beats/min; P = n.s.). The acid-base status deteriorated slowly during surgery. Values before and after cross-clamping were: pH (7.42 (0.04) versus 7.37(0.06); P < 0.05), base excess (-0.67(2.20) versus -3.70(2.50); P < 0.05) and bicarbonates (24(8.9) versus 20(1.9); P < 0.05). The cerebrospinal fluid pressure remained constant: 20(5.7) versus 19(5.9) versus 18(5) versus 19(5) mmHg; P = n.s. Renal function, measured before, and at 1, 3 and 7 days after the operation also remained stable (creatinine: 1.1(0.4) versus 1.2(0.4) versus 1.2(0.4) versus 1.2(0.4); P = n.s.; blood urea nitrogen: 46(18.7) versus 46(18.6) versus 51(24.9) versus 55(27.9); P = n.s.). Step-wise multiple linear regression comparing cerebrospinal fluid pressure against haemodynamic and metabolic data showed that during aortic cross-clamping there was a significant relationship between central venous pressure (P < 0.0013) and arterial pH (P < 0.0148), while before and after cross-clamping multivariate analysis showed a relationship only between central venous pressure and cerebrospinal fluid pressure (P < 0.0035). The results confirm that centrifugal pump support is effective in stabilizing haemodynamics and protecting the kidney during thoracoabdominal aneurysm repair.

Mid-term follow-up of 183 arterial myocardial revascularization procedures

OBJECTIVE

To evaluate the mid-term results of complete arterial myocardial revascularization performed with arterial conduits.

METHODS

From July 1987 to December 1994, 183 patients underwent a myocardial revascularization procedure with the use of at least two arterial grafts (IMAs, rGEA, IEA) at our institute. Their mean age was 56 +/- 8.7 years, the redo-operation rate was 16.9% (31/183), two-vessel disease was present in 61 patients (33.3%), three-vessel disease in 122 (66.7%).

RESULTS

The LIMA was used in 179 patients (97.8%), the RIMA in 116 (63.4%), the rGEA in 66 (36.1%) and the IEA in 41 (22.4%). In-hospital mortality was 1.1% (2/183), while the perioperative myocardial infarction (MI) rate was 2.2% (4/183). The angiographic restudy, performed on 87 (47.5%) patients during the early postoperative period (median 38 days) showed the following grafts patency rates: LIMA 98.8 (86/87), RIMA 97.1 (34/35), IEA 85.7 (24/28), rGEA 97.05 (33/34) and saphenous vein 90.9% (10/11). The median follow-up was 35 months. Kaplan-Meier survival was 96 +/- 2% at 3 and 5 years, freedom from angina 94 +/- 2% at 3 years and 91 +/- 3% at 5 years, while the Kaplan-Meier freedom from cardiac events was 90 +/- 3% at 3 years and 88 +/- 3% at 5 years. Cox regression analysis identified perioperative MI (P = 0.03, relative risk 3.6) as the only prognostic factor for mortality at follow-up. With regards to recurrence of angina, multivariate analysis has shown that incremental risk factors for the return of angina are redo-operation (P < 0.01, relative risk 2.7) and the persistence of hypertension after surgery (P < 0.01; relative risk 3.2), while the use of the RIMA in the operation has emerged as a protective factor (P = 0.02; relative risk 0.43). Finally, only redo-operation (P < 0.01; relative risk 2.3), has emerged as a predictor of cardiac complications.

CONCLUSION

Myocardial revascularization with at least two arterial grafts can be performed with very low perioperative morbidity and mortality and good mid-term follow-up. The mid-term results of arterial myocardial revascularization are less favourable in cases of redo-operations or when the RIMA is not used.

Aprotinin and deep hypothermic circulatory arrest: there are no benefits even when appropriate amounts of heparin are given

OBJECTIVE

To evaluate retrospectively the effect of 'high-dose' aprotinin on blood losses, donor blood requirements and morbid events on patients undergoing ascending aorta and/or aortic arch procedures with the employ of deep hypothermic circulatory arrest (HCA).

METHODS

During the period 1987-1994, 39 patients underwent a thoracic aorta procedure with the employ of circulatory arrest; of these 18 (46.2%) were operated on during the period 1990-1994 and were given aprotinin intraoperatively following the 'high-dose' protocol (group I), while 21 (53.8%) who underwent surgery during the years 1987-1989, did not receive intraoperative aprotinin and served as historical controls (group II). Twenty-seven (69.2%) patients were male, 18 (46.2%) were operated on on an emergency basis, 15 (38.5%) were acute type A dissections, and two (5.1%) were redo-operations. Circulatory arrest times were not significantly different between the two groups (40 +/- 4 (S.E.) group I vs. 43 +/- 4 min group II, P = 0.62) likewise cardiopulmonary bypass (CPB) times (181 +/- 9 vs. 201 +/- 20 mm, P = 0.74) and the amount of heparin administered (32056 +/- 1435 vs. 31 691 +/- 1935 IU, P = 0.56).

RESULTS

Postoperative blood loss was comparable between the two groups (1213 +/- 243 (median 850) group I vs. 1528 +/- 377 (median 880) ml group II, P = 0.87), as well as the number of units of donor blood transfused (9.4 +/- 3.0 (median 6) vs. 9.9 +/- 3.6, (median 5) P = 0.87), and revisions for bleeding (2/18, 11.1% vs. 3/21, 14.3%, P = 0.77). In-hospital mortality rate was not statistically different (5/18, 27.7% group I vs. 6/21, 28.6% group II, P = 0.92). There were no significant differences between the two groups in myocardial infarction (2/18, 11.1% vs. 0/21, 0%, P = 0.21), and postoperative renal failure rates (3/18, 16.7% vs. 2/21, 9.5%, P = 0.65). On the other hand, there was a trend towards an increased incidence of permanent neurological deficit (5/18, 27.7% group I vs. 1/21, 4.8% group II, P = 0.07) and towards a more complicated postoperative course (perioperative renal failure and/or myocardial infarction and/or neurological deficit either transient or permanent) (8/18, 44.4% group I vs. 4/21, 19% group II, P = 0.09) in group I patients. Forward stepwise logistic regression analysis, performed on the whole group of patients, identified chronic obstructive pulmonary disease (P = 0.010, Odds ratio (OR) = 5.7), aprotinin use (P = 0.017, OR = 5.1), and the number of units of blood collected intraoperatively by the cellsaver (P = 0.045, OR = 1.3/unit) as independent predictors of complicated postoperative course in the whole group of patients. CPB time (P = 0.040, OR = 1.032/min), circulatory arrest time (P = 0.053, OR = 1.22/min), and overall donor blood units transfused (P = 0.067, OR = 1.37/unit) emerged as independent risk factors for in-hospital mortality at multivariate analysis.

CONCLUSIONS

Even when appropriate amounts of heparin are administered, 'high-dose' aprotinin probably is not an effective blood-sparing drug in deep HCA. Aprotinin should be employed cautiously in this clinical setting because of its possible correlation with an increased rate of postoperative morbid events.

Myocardial revascularization procedures on multisegment diseased left anterior descending artery: endarterectomy or multiple sequential anastomoses (jumping)?

Complete revascularization is the primary goal in coronary surgery because of its superior long term results. However, in some patients the extent of the coronary artery disease is such that the usual coronary bypass technique may not allow to perform a complete myocardial surgical revascularization and, consequently, a satisfactory myocardial perfusion: so complementary revascularization techniques may become mandatory, especially when the diseased vessel is LAD or its branches. As a consequence, alternative procedures should be undertaken: coronary endarterectomy (EA) and multiple sequential anastomoses on a single vessel (jump), which guidelines are actually somehow controversial. Between January, 1989, and May, 1992, 53 patients underwent a myocardial revascularization procedure on LAD system unsuitable for single distal bypass; of them 35 (66%) underwent coronary endarterectomy, while in 18 (34%) multiple sequential anastomoses (jumping) were performed on the same vessel. About preoperative variables, average NYHA class (2.7 jump vs 2.1 EA group, p < 0.05), the history of more than 1 myocardial infarction (22.2% jump vs 2.9% EA, p < 0.04) and the presence of preoperative nitrates e.v (33.3% vs 8.6%, p < 0.04) were statistically higher in the jump group, suggesting a more unstable clinical status, while other clinical echocardiographic and catheterization features were not statistically different. For what operative and postoperative features are concerned, the number of anastomoses performed was statistically higher in the jump group, as exasperated (3.8 vs 2.7, p < 0.002) while perfusion (138 vs 141 min) and crossclamp time (103 vs 106 min) were similar. Furthermore we found a statistically lower incidence of perioperative myocardial infarction (0% jump is 22.8% EA group, p < 0.04); the postperfusion inotropic drugs requirement (22.2% vs 37.1%), the need of an intraaortic counterpulsation (0% vs 2.9%) and the in-hospital mortality (0% vs 5.7%) were lower in the jumping group too, also if they didn't reach statistical significance. Our experience suggest, also with the limits imposed by a retrospective case review and by a low number of cases reported, that myocardial revascularization of a multisegment diseased LAD system may be safely performed with the jumping technique with a low incidence of postoperative complications: it should be the first choice technique when conventional revascularization procedures are not enough to achieve complete myocardial revascularization. We advocate the use of EA technique only in that cases characterized by a diffuse atherosclerotic core and a well delimited plane of dissection, associated to a very poor runoff, which really excludes any chance to multiple anastomoses.

[Heart surgery, cardiopulmonary bypass, and organic inflammatory response. Part II: changes in leukocytes, arachidonic acid derivatives, and hormones]

The use of cardiopulmonary bypass for surgical cardiac procedures is characterized by a whole-body inflammatory reaction due to the contact of blood through nonendothelialized surfaces; this stimulates the organism to recognize the cardiopulmonary bypass system as "nonself" and to activate specific (immune) and nonspecific (inflammatory) responses. These responses are then related with postoperative damage to many body systems of the body, like pulmonary, renal or brain dysfunction, excessive bleeding and postoperative sepsis. In this paper, present knowledge on untoward responses of the patient to cardiopulmonary bypass in cardiac surgery is reviewed and discussed, particularly focusing on the perturbation of the leukocytes, of the hormones and of the products of the arachidonic acid cascade.

[Heart surgery, cardiopulmonary bypass and inflammatory response. I. Changes in hemostasis and complement]

The use of cardiopulmonary bypass for surgical cardiac procedures is characterized by a whole-body inflammatory reaction due to the contact of blood through nonendothelialized surfaces; this stimulates the organism to recognize the cardiopulmonary bypass system as "nonself" and to activate specific (immune) and nonspecific (inflammatory) responses. These responses are then related with postoperative damage to many body systems, like pulmonary, renal or brain dysfunction, excessive bleeding and postoperative sepsis. In this paper, present knowledge on untoward responses of the patient to the use of cardiopulmonary bypass in cardiac surgery is reviewed and discussed, particularly focusing on the perturbation of the hemostasis and of the complement activation system.

Midterm angiographic study of five recycled mammary arteries during four coronary redos

BACKGROUND

Recently the technical feasibility of reusing the left internal mammary artery (IMA) in coronary artery reoperation has been documented, but the patency of "recycled" IMAs has not yet been established.

METHODS

In 4 patients undergoing coronary reoperation, five internal mammary arteries (3 left IMAs and 2 right IMAs) that were patent but severely stenotic at the anastomotic site were taken down and reused. In 2 cases the IMAs were reanastomosed to the same target coronary artery, in 2 cases the IMAs were rerouted to another coronary artery, and in 1 case an interposition of a short segment of the greater saphenous vein was needed to reach the target coronary artery.

RESULTS

Angiographic midterm evaluation, performed between 7 and 35 months postoperatively, showed patency of all the reused grafts without stenoses.

CONCLUSIONS

When feasible, recycling of the IMAs may be considered if one or both IMAs have been previously used and are stenotic in the perianastomotic area, or when there is a stenosis in the native coronary artery distal to the anastomosis itself.

The effect of multiple blood conservation techniques on donor blood exposure in adult coronary and valve surgery performed with a membrane oxygenator: a multivariate analysis on 1310 patients

The object of the study was to retrospectively evaluate protective and risk factors for receiving donor blood products and red cell transfusions after coronary and valve surgery performed with a hollow-fiber oxygenator and with multiple blood-saving techniques. During the period of January 1991 to June 1993, 1310 patients underwent primary coronary and valve surgery using a hollow-fiber oxygenator at our institution; the mean age of this population was 61 +/- 10 years; 977 patients were men (74.6%). Of these patients, 73.5% (963/1310) underwent coronary, 21.5% (281/1310) valve, and 5% (66/1310) combined surgery. Two hundred seventy-six (21.1%) needed donor blood product transfusions, while 153 (11.7%) patients underwent red cell transfusions. Significant risk factors for homologous blood product exposure after multivariate logistic regression analysis were, in order of importance: (1) postoperative blood loss (O.R. = 1.0009 per mL, p = 0.0000); (2) cardiopulmonary bypass (CPB) time (O.R. = 1.008 per min, p = 0.0001); (3) age at intervention (O.R. = 1.031 per calendar year, p = 0.0026); and (4) reoperation for bleeding (O.R. = 1.71, p = 0.0078). Protective factors were: (1) male gender (O.R. = 0.56, p = 0.0000); (2) preoperative withdrawal of autologous blood (O.R. = 0.66, p = 0.0018); and (3) a preoperative hematocrit greater than 34% (O.R. = 0.76, p = 0.0005).(ABSTRACT TRUNCATED AT 250 WORDS)

One month follow-up of haemostatic variables in patients undergoing aortocoronary bypass surgery. Effect of aprotinin

It is already known that activation of the coagulation and fibrinolytic system occurs in patients undergoing cardiopulmonary bypass (CPB). We have thus studied twenty patients (10 treated with aprotinin during CPB and 10 untreated) both during the intraoperative period and during thirty days follow up. In untreated patients D-dimer levels increased 4-fold during CPB and the levels were above baseline for the whole follow up (p < 0.0001). D-dimer levels were reduced in aprotinin treated patients in comparison to untreated patients (p = 0.0172); levels then gradually increased to the values of the untreated patients over the following 24 h later and remained higher during the thirty day follow up. The behavior of haemostatic variables in the 24 h after CPB did not vary between untreated and aprotinin treated patients. In particular, five minutes after protamine sulphate administration, levels of F1 + 2 and TAT rose significantly (p = 0.0054, p = 0.0022 respectively), whereas fibrinogen significantly decreased (p < 0.0001) and PAI-1 antigen levels were reduced. Two days after CPB the concentrations of F1 + 2 and TAT lowered, whereas fibrinogen and PAI-1 antigen levels increased. On the 5th, 8th and 30th days after CPB, F1 + 2 and TAT levels remained higher than those reported at baseline in both groups of patients, whereas fibrinogen levels increased over basal levels in aprotinin treated patients only. Thus, in addition to the activation of the coagulation and fibrinolytic system occurring during the intraoperative period, in patients undergoing CPB, there are alterations of haemostatic variables up to thirty days from surgery.

False hydatic aneurysm of the thoracic aorta

In this article we report the successful treatment of a lower descending thoracic aorta hydatidosis that mimicked a posterior saccular aneurysm; surgical excision was performed and the aorta was repaired with a prosthetic Dacron patch. At a 26-month follow-up, the patient is alive and conducting a normal life. Discussion about the management of this rare case also is given.

The effect of "high dose" aprotinin and other factors on bleeding and revisions for bleeding in adult coronary and valve operations: an analysis of 2190 patients during a five-year period (1987-1991)

We retrospectively evaluated risk factors for postoperative bleeding and for revisions due to bleeding in 2190 adult coronary and valve patients who underwent surgery at our hospital during the 5-year period from 1987 to 1991. During this period 889 (40.6%) patients were given "high dose" aprotinin. Their mean age was 59.3 +/- 8.8 years, 1636 (74.7%) were males, 200 (9.1%) underwent surgery on an emergency basis and 72 patients (3.3%) underwent redo-operations. The patients were divided into four groups according to the type of surgery: all patients pooled together (2190), coronary artery surgery patients (1384, 63.2%, group I), valve surgery patients (706, 32.2%, group II) and combined (coronary plus valve) surgery patients (100, 4.6%, group III). Stepwise logistic regression analysis, performed to assess the risk factors for revisions due to bleeding showed aprotinin treatment to be the sole protective factor in all patients, group I and group II. In group III only the use of a hollow fiber membrane oxygenator proved a protective factor. Risk factors for revisions for bleeding were found to be aortic cross-clamp time in all patients, group I and group II. Use of the internal thoracic artery (ITA) was significant in group I patients and age at operation in group II. Multiple stepwise linear regression analysis, performed to evaluate the effect of various risk factors on cumulative postoperative blood loss in all patients, confirmed aprotinin as the only factor capable of reducing blood loss, while aortic cross-clamp time, coronary surgery and male gender showed a positive linear relation with postoperative bleeding.(ABSTRACT TRUNCATED AT 250 WORDS)

Composite valve graft replacement of the ascending aorta and the aortic valve by a modified button technique: the influence of aortic pathology on early mortality and late survival

The risk factors for in-hospital mortality and mid-term survival in patients undergoing composite graft replacement of the aortic root with reimplant or coronary arteries by a modified button technique were evaluated with special emphasis on the underlying aortic pathology. Between 1985 and 1993 74 patients underwent replacement of the ascending aorta and the aortic valve following a modified button technique. The patients were divided into three groups according to aortic pathology: annuloaortic ectasia (43.58%), type A dissection (18.24%), and miscellaneous (13.18%). In-hospital mortality rates were 4.7%, 33.3% and 23.1%, respectively (P = 0.011). Univariate analysis showed that aortic pathology, NYHA class, emergency operation, redo operation, acute aortic dissection, preoperative cardiogenic shock, preoperative cardiac tamponade, longer cardiopulmonary bypass (CPB) and aortic cross-clamp times, and the need of femoral vein or femoral artery cannulation at intervention had univariate influence on in-hospital mortality. Multivariable stepwise logistic regression analysis identified CPB time odds ratio (OR) = 1.021/min, P = 0.007), the need of femoral vein cannulation at intervention (OR= 4.85, P = 0.008) and preoperative cardiac tamponade (OR = 3.11, P = 0.07) as independent predictors of in-hospital death. Follow-up ranged from 1 to 98 months (mean 39 +/- 30 months) with an actuarial survival rate of 75 +/- 9%, 52 +/- 13% and 67 +/- 14% at 5 years in annuloaortic ectasia, type A dissection, and miscellaneous patients, respectively (P = 0.18); when survival was evaluated in hospital survivors only, Kaplan-Meier survival rates were 77 +/- 9%, 79 +/- 14% and 89 +/- 10% at 5 years (P = 0.87). Comparing survival of annuloaortic ectasia patients (5-year survival 75 +/- 9%) versus survival of all other patients pooled together (5-year survival 55 +/- 11%), there was a statistically significant difference (P < 0.05); such a difference was no longer significant when comparing hospital survivors alone (5-year survival rate 77 +/- 9% annuloaortic ectasia patients vs 79 +/- 12% all other patients P = 0.61). Although aortic root replacement carries higher in-hospital mortality in some high-risk subgroups of patients, mid-term survival seems to be less affected by aortic pathology; high-risk patients are expected to have an out-hospital outcome comparable to the low-risk ones.

[Retrospective study of the efficacy of aprotinin in heart valve surgery in adults]

Aprotinin effects on postoperative bleeding, redo operations due to excessive bleeding and postoperative blood products use have been retrospectively evaluated on a population of 894 consecutive patients operated upon between 1987 and 1991 for valvular surgery. In this period, aprotinin has been routinely used following the "High Dose" protocol starting from January 1990. To analyse results, all the patients considered (Group I) were divided into subgroups, following the heart valve operated upon, in "mitral" patients (391 patients, 43.7%, Group II), "aortic" patients (375 patients, 41.9%, Group III) and "mitro-aortic" patients (128 patients, 14.3%, Group IV). Each of these Groups has been subsequently split depending on whether or not they received aprotinin (Subgroups IA, IIA, IIIA, IVA with aprotinin, subgroups IB, IIB, IIIB, IVB without aprotinin). Considering the whole population (Group I), aprotinin determined a significant reduction of post-operative bleeding (499 +/- 634 ml Group IA versus 713 +/- 572 Group IB, p = 0.000), redo operations for bleeding (15/410, 3.7% Group IA versus 45/484, 9.3% Group IB, p = 0.0000) and consequently the percentage of patients exposed to blood products transfusion (37/410, 9% Group IA versus 163/484, 54.3% Group IB p = 0.0000). When the other Groups (II, III and IV) were considered, aprotinin determined a significant reduction of postoperative bleeding and of donor blood transfusions, while redo operations for bleeding, although less in total number, were not significantly reduced. Moreover, aprotinin has been effective in reducing postoperative blood losses, redo-operation for bleeding and blood use independently of the kind of oxygenator used: bubble vs hollow fibers.(ABSTRACT TRUNCATED AT 250 WORDS)

Prostacyclin production by different human grafts employed in coronary operations

Segments of human saphenous vein, internal mammary artery, right gastroepiploic artery, and inferior epigastric artery were incubated in vitro in Krebs-Henseleit solution and compared in terms of their capacity to generate and release into the medium 6-keto-prostaglandin F1 alpha (PGF1 alpha), the stable metabolite of prostacyclin. The four vascular conduits were also challenged with endothelin-1 (40 ng/mL), and accumulation of the lipidic material in the bathing fluid was also studied. The results obtained show clearly that under both normal and endothelin-1-stimulated conditions, the four vascular segments generate a substantial amount of 6-keto-PGF1 alpha. Multiple-comparisons analysis of the results indicates that the rank order in producing 6-keto-PGF1 alpha is as follows: inferior epigastric artery > internal mammary artery > right gastroepiploic artery > saphenous vein (p < 0.01). A similar order of potency was obtained in vascular conduits stimulated with endothelin-1. The rate of formation of immunoreactive 6-keto-PGF1 alpha under both normal and stimulated conditions by the inferior epigastric artery (normal, 301 +/- 8 pg/mg of tissue; stimulated, 519 +/- 15 pg/mg of tissue) was at 10 minutes more than 2 times (p < 0.01) that of the saphenous vein and about 1.5 times (p < 0.01) that of the right gastroepiploic artery.(ABSTRACT TRUNCATED AT 250 WORDS)

Reoperative cardiac valve surgery: a multivariable analysis of risk factors

From December 1983 to March 1992, of 1650 patients who underwent a cardiac valve procedure 41 (2.5%) underwent reoperation on prosthetic heart valves. The indications for reoperation were: structural degeneration (13 patients, 32%), non-structural dysfunction (nine patients, 22%), prosthetic valve endocarditis (seven patients, 17%), valve thrombosis (four patients, 10%), native valve pathology (three patients, 7%), aortic ascending pathology (five patients, 12%). The hospital mortality rate for mitral valve reoperation was 12% (two of 17) and for reoperation on the aortic prosthesis 26% (five of 19). No deaths occurred for associated mitral and aortic replacement (zero of five). The mortality rate for associated procedures was 24% (four of 17) versus 12% (three of 24) for isolated procedures. Preoperative and operative variables were analysed to determine risk factors for hospital mortality. New York Heart Association functional class, ascites, endocarditis and surgical timing had a univariate influence on operative mortality. The pulmonary capillary wedge pressure and preoperative creatinine level were also higher in non-survivors. Elective reoperation had a mortality rate of 7%, while that for emergency procedures was 38%. Multivariable analysis indicated a longer extracorporeal circulation time and the urgent-emergency status as predictors of mortality. Reoperation before severe haemodynamic impairment occurs is recommended.