[Coronary aneurysm, it exists !]

Coronary aneurysm has an incidence of 1,1 to 4,9 % in patients undergoing a coronary angiography. Many etiologies may be accused, atherosclerosis is associated in up to 50 % of cases. We report the case of a 76-year-old patient with a large coronary aneurysm.

Natural history of the enlarged ascending thoracic aorta: an observational long term study

 

To assess the long-term outcome of patients with an enlarged ascending thoracic aorta (ATA), a retrospective study was performed.

Methods

Inclusion criteria: ATA diameter of 38 mm or more by ETT (813 consecutive cases).

Inclusion period: 1.1.2003–31.12.2016.

Results

At baseline, the mean diameter of the ATA was 42±3 mm, the mean Z-score was 2.7±0.8.

In the subgroup of patients with 2 ETT examinations (and no surgical cure of the ATA), the mean diameter was 41.9±4.8 mm, the mean Z-score 2.4±1.1 after a mean follow-up of 6 years.

During the follow-up, 52 patients had an intervention on the ATA, 26 patients were operated within the first 3 months after the diagnostic echocardiogram. 26 patients were operated during FU.

In the 791 remaining patients (without early intervention), the event rate (death, intervention on the ATA) were assessed by the competing risk model.

In the group of patients with a baseline ATA diameter of less than 41 mm (Group A: n=254), the cumulative incidence of death at 5 and 10 y was 34% and 61%; in the group of patients with an ATA diameter of 41–42 mm (Group B: n=238) the incidence was 34% and 61% respectively, in the group of patients with an ATA diameter of 43–44 mm (Group C: n=147), the incidence was 32% and 58%, in the group of patients with a diameter of 45 and more (Group D: n=150), the incidence was 31.1% and 61% (NS).

The cumulative incidence of surgical interventions on the ATA at 5 and 10 years was 0.4% and 1% in group A, 1.3 and 1.8% in group B, 0.7 and 1.4% in group C and 9.8 and 12.9% in group D (p<0.05).

Similar results were observed in patients according to the Z-scores. In the group of patients (221) with a Z-score >3, the incidence of intervention at 5 and 10 y was respectively 7.6% and 10.7% (p=0.01).

Conclusions

– The mean diameter of the enlarged ATA remained nearly unchanged over a period of 6 years.

– No impact of the enlarged ATA on survival was observed.

– Only patients with an ATA diameter of 45 mm and more (or a Z-score of 3 and more) needed an intervention on the ATA at a rate of ± 10% at 10 y after the initial echocardiographic diagnosis.

Funding Acknowledgement

Type of funding source: None

Case-matched comparison of early and long-term outcomes of everted cervical vein and saphenous vein carotid patch angioplasty

OBJECTIVES

To compare outcomes after carotid endarterectomy (CEA) with saphenous vein patch closure (SV), with cervical vein (external jugular and common facial) patch closure (CV).

DESIGN

A total of 322 cases of CEA was achieved consecutively by using venous patch angioplasty. Propensity scores were calculated followed by a one-to-one basis case-matching.

MATERIALS

This resulted into 90 SV and 90 CV matched cases.

METHODS

The primary endpoint was the incidence of ipsilateral stroke and transient ischaemic attack at any time during follow-up.

RESULTS

Ten-year freedom from stroke was 94.1% ± 3.5% for the SV group and 90.5% ± 4.2% for the CV group (log rank P = 0.230). Ten-year freedom from ipsilateral neurological events (stroke and transient ischaemic attack) was 93.5% ± 3.3% for SV group and 92.4% ± 3.0% for the CV group (log rank P = 0.403). Ten-year freedom from ≥75% stenosis/occlusion was 93.1 ± 4.8% for the SV group and 89.9 ± 6.0% for the CV group (log rank P = 0.481).

CONCLUSIONS

CV is a good alternative to SV patching, particularly when the SV needs to be preserved for further use or is unsuitable.

Practice variability in the management of infrarenal arterial stenoses in seven Belgian hospitals

This multicentre retrospective study describes the variation of therapeutic options, treatment outcomes and costs for treating infrarenal arterial stenoses as observed in daily practice in 1997-99 in seven Belgian hospitals. Data were obtained from clinical record review and from the sickness fund claims database, and included preoperative functional state, presence of acute ischaemia, diabetes and polyvascular disease, state of the lower-leg run-off arteries, anatomical site and type of lesion, type of treatment, result at 30 days and up to 4 years. A total of 442 episodes were studied, but most analyses dealt with a subgroup of 240 lesions in the common iliac up to the superficial femoral artery. The proportion of surgical treatments (as compared to an endovascular or mixed approach) varied from 15% to 81% between the hospitals. In univariate survival analysis, relapse or failure rates at 4 years ranged from 5% for the common iliac artery to 35% for the superficial femoral artery. Polyvascular disease, a poor run-off, multiple stenoses and chronic occlusion were significant risk factors; age and diabetes were not. In the multivariate (stratified Cox regression) analysis, only a location in the superficial femoral artery and a poor preoperative clinical stage were significant risk factors, but type of therapeutic approach was not. The total average cost of treatment was 5300 Euro, of which 15% was contributed by the patient. Surgery was associated with longer stays (median at 12 days) than endovascular treatments (median 2 d), and was 1.9 times more expensive. In conclusion, the results of the present study suggest that a multidisciplinary approach, orienting the patient to the most appropriate therapeutic pathway could increase both the quality and the cost-effectiveness of the care. In many clinical situations, the endovascular approach appears to offer similar long-term results as surgery, but at a substantially lower cost, both for the patient and for society, especially when performed in a (semi-)ambulatory radiology setting.

Practice variability in the management of subrenal arterial stenoses in seven Belgian hospitals

This multicentre retrospective study describes the variation of therapeutic options, treatment outcomes and costs for treating subrenal arterial stenoses as observed in daily practice in 1997-99 in seven Belgian hospitals. Data were obtained from clinical record review and from the sickness fund claims database, and included preoperative functional state, presence of acute ischaemia, diabetes and polyvascular disease, state of the lower-leg run-off arteries, anatomical site and type of lesion, type of treatment, result at 30 days and up to 4 years. A total of 442 episodes were studied, but most analyses dealt with a subgroup of 240 lesions in the common iliac up to the superficial femoral artery. The proportion of surgical treatments (as compared to an endovascular or mixed approach) varied from 15% to 81% between the hospitals. In univariate patency analysis, relapse or failure rates at 4 years ranged from 5% for the common iliac artery to 35% for the superficial femoral artery. Polyvascular disease, a poor run-off, multiple stenoses and chronic occlusion were significant risk factors; age and diabetes were not. In the multivariate (stratified Cox regression) analysis, only a location in the superficial femoral artery and a poor preoperative clinical stage were significant risk factors, but type of therapeutic approach was not. The total average cost of treatment was 5,300 Euros, of which 15% was contributed by the patient. Surgery was associated with longer stays (median at 12 days) than endovascular treatments (median 2 days), and was 1.9 times more expensive. In conclusion, the results of the present study suggest that a multidisciplinary approach, orienting the patient to the most appropriate therapeutic pathway, could increase both the quality and the cost-effectiveness of the care.

Patent foramen ovale: a cause of significant post-coronary artery bypass grafting morbidity

We describe two patients who underwent coronary artery bypass grafting complicated by postoperative hypoxemia due to a patent foramen ovale with right-to-left shunting. We discuss different hypotheses to explain the shunt: decreased right ventricular compliance, right atrial geometric changes due to septal distension or ischemia, exceeding filling pressure and localised haemorragic pericardial tamponade and low atrial pressure when correcting aortic stenosis. We emphasize the close interplay of pericardectomy and the four cardiac chambers including the distortion of the heart axis. The contrast echo produced by microbubbles of air is the safest and the most accurate procedure to detect the shunt. The two patients progressed positively with an extracorporeal circulation of short duration and without complications linked to the intervention. We conclude that postoperative unexplained hypoxemia must always exclude diagnosis of right-to-left shunting due to a patent foramen ovale (PFO).

Six hundred consecutive carotid endarterectomies with temporary shunt and vein patch angioplasty: early and long-term results

PURPOSE

This retrospective study evaluates the long-term clinical outcome and the survival of 600 consecutive carotid endarterectomies performed with a temporary shunt. All arteriotomies were closed by vein patch angioplasty.

MATERIALS AND METHODS

Between November 1989 and November 1998, 600 isolated carotid endarterectomies (CEA) were performed in 540 patients by a uniform surgical technique at the University Clinic of Mont-Godinne. An intraluminal shunt and patch closure were systematically used. The mean age was 68 yr (ranging from 41 to 91 yr), 400 patients were men. The risk factors included hypertension in 73%, smoking history in 60%, coronary artery disease in 51% and hyperlipidemia in 35%. The indications were asymptomatic stenosis in 47%, transient ischemic attack in 40%, vertebrobasilar symptoms in 7% and stroke in 6%.

EARLY RESULTS

The combined 30-day stroke and death rate was 0.9%. There were four deaths. The stroke and TIAs rates were 0.2% and 1.5% respectively. The incidence of early carotid occlusion was 0.5%. Cranial or cervical nerve dysfunction was identified in 6.3%. LATE RESULTS: The median follow-up was 49 months with a range of 2-124 months. Cumulative survival rates at 5 and 10 yr were 92+/-1% and 89+/-2% respectively. Thirty-two patients died during long-term follow-up; the death was stroke-related in only three patients.

CONCLUSION

Carotid endarterectomy using an intraluminal shunt and vein patch closure is a safe and effective procedure associated with low morbidity and mortality rates at short and long-term follow-up.

Beating heart surgery using the Octopus tissue stabilizers: initial experience including triple vessel disease and high-risk patients

OBJECTIVE

The aim of this study was to evaluate initial results in beating heart coronary artery bypass grafting performed on patients with multivessel disease, using suction-based tissue stabilizers.

METHODS

Forty patients (mean age 65.5 years, range 39-83) underwent beating heart coronary bypass by median sternotomy, with the use of the Octopus 1 (n = 27) and Octopus 2 (n = 13) devices. Twenty patients had unstable angina, four had pulmonary oedema, and four required preoperative intra-aortic balloon counterpulsation. Five interventions were repeat procedures. Mean ejection fraction was 54.4%(range 20-82%). Eighteen patients had triple-vessel disease, 18 patients had double-vessel disease and > 50% left main stem stenosis was present in six patients (isolated or in association). The average number of distal anastomoses was 2.5 (range 1-5, total 101). A mean of 1.5 (range 1-3) anastomoses was achieved with arterial grafts (45 mammary and 12 gastroepiploic arteries).

RESULTS

Immediate graft patency was evaluated by Doppler flowmeter and five anastomoses were successfully corrected, based on an occlusion pattern. The perioperative myocardial infarction rate was zero. Transient episodes of supraventricular arrhythmias were detected in 19 patients. The administration of dobutamine at an inotropic concentration > 5 gamma-1 kg-1 min-1 was required in one patient. There were two in-hospital deaths (one non-cardiac-related). Overall survival and cardiac event-free rate at 20 months were 92.4% +/- 4.2% and 81.8% +/- 11.6%, respectively.

CONCLUSIONS

Satisfactory results can be achieved in multivessel disease high-risk patients with beating heart coronary bypass surgery.

Effective prevention of atrial fibrillation by continuous atrial overdrive pacing after coronary artery bypass surgery

OBJECTIVES

The present study was aimed to evaluate the efficacy of a specific algorithm with continuous atrial dynamic overdrive pacing to prevent atrial fibrillation (AF) after coronary artery bypass graft (CABG) surgery.

BACKGROUND

Atrial fibrillation occurs in 30% to 40% of patients after cardiac surgery with a peak incidence on the second day. It still represents a challenge for postoperative prevention and treatment and may have medical and cost implications.

METHODS

Ninety-six consecutive patients undergoing CABG for severe coronary artery disease and in sinus rhythm without antiarrhythmic therapy on the second postoperative day were randomized to have or not 24 h of atrial pacing through temporary epicardial wires using a permanent dynamic overdrive algorithm. Holter ECGs recorded the same day in both groups were analyzed to detect AF occurrence.

RESULTS

No difference was observed in baseline data between the two study groups, particularly for age, male gender, history of AF, ventricular function, severity of coronary artery disease, preoperative beta-adrenergic blocking agent therapy or P-wave duration. The incidence of AF was significantly lower (p = 0.036) in the paced group (10%) compared with control subjects (27%). Multivariate analysis showed AF incidence to increase with age (p = 0.051) but not in patients with pacing (p = 0.078). It decreased with a better left ventricular ejection fraction only in conjunction with atrial pacing (p = 0.018).

CONCLUSIONS

We conclude that continuous atrial pacing with an algorithm for dynamic overdrive reduces significantly incidence of AF the second day after CABG surgery, particularly in patients with preserved left ventricular function.

Adaptive mechanisms of arterial and venous coronary bypass grafts to an increase in flow demand

OBJECTIVE

To compare the mechanisms by which arterial and venous grafts increase their flow during pacing induced tachycardia, early and later after coronary bypass surgery.

DESIGN

43 grafts (13 epigastric artery, 15 mammary artery, 15 saphenous vein) evaluated early (9 (3) days (mean (SD)) after bypass surgery were compared with 41 other grafts (15 epigastric, 11 mammary, 15 saphenous vein) evaluated later after surgery (mean 23 months, range 6 to 168 months) by quantitative angiography and intravascular Doppler velocity analysis during atrial pacing. Controls were 17 normal coronary arteries.

RESULTS

Baseline graft flow tended to be lower later after surgery than early (41 (16) v 45 (21) ml/min, NS). Blood flow increased during pacing by 30 (16)% early after surgery, less than later after surgery (+46 (18)%, p < 0.001) and less than in normal coronary arteries (+54 (27)%, p < 0.001 v early grafts; NS v late grafts). There was no difference between venous and arterial grafts. No significant vasodilatation was observed during pacing early after surgery in arterial and venous grafts. Later after surgery, significant vasodilatation was observed only in arterial grafts (mammary and epigastric grafts), from 2.41 (0.37) to 2.53 (0. 41) mm (+5.1% v basal, p < 0.001). Early after surgery and in venous grafts later after surgery, the increase in flow was entirely due to an increase in velocity. In later arterial grafts, the relative contribution of the increase in velocity to the increase in flow during pacing was lower in arterial grafts (70 (22)%) than in venous grafts (102 (11)%, p < 0.001) and similar to normal coronary arteries (68 (28)%).

CONCLUSIONS

Early and later after surgery, arterial grafts and venous grafts both increase their flow similarly during pacing. Early arterial grafts and venous grafts increase their flow only through an increase in velocity. Later after surgery, arterial grafts act as more physiological conduits and increase their flow in the same way as normal coronary arteries, through an increase in velocity and calibre mediated by the endothelium.

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.

The Ross operation: mid-term results

BACKGROUND

The Ross operation, although more demanding, is now widely accepted as an alternative solution for aortic valve replacement in young adults and children. A review of our experience to assess the mid-term results with the Ross operation is presented.

METHODS

From June 1991 through October 1997, 80 patients (mean age, 31 years) underwent aortic valve or root replacement with pulmonary autografts. Indications for operation were predominant aortic stenosis in 38 patients, aortic incompetence in 42 patients including endocarditis in 3 patients. Congenital lesions were present in 57 patients, either at pediatric (27 patients) or adult age (30 patients). Transthoracic echocardiography was performed preoperatively in all patients and serially after operation with the aims of measuring aortic and pulmonary annuli, evaluating transvalvular gradients and incompetence, and studying the left ventricular function. Intraoperative transesophageal echocardiography was used routinely. Complete root replacement was performed in 52 patients, intraluminal cylinder in 25 patients, and subcoronary implantation in 3 patients.

RESULTS

One patient died in the early postoperative period (1.2%). There was no late death. The actuarial survival at 5 years was 98%+/-1%. All survivors remained in New York Heart Association functional class I and were free of complications and medications. No gradient or significant aortic incompetence could be demonstrated in 73 patients. One patient developed late aortic incompetence grade 3 and reoperation is considered. On the pulmonary outflow tract, 6 patients had gradients between 20 and 40 mm Hg as calculated on echocardiography.

CONCLUSIONS

The pulmonary autograft gives excellent mid-term results with low mortality and no morbidity. It completely relieves the abnormal loading conditions of the left ventricle, resulting in a complete recovery of left ventricular function in most patients.

Intraoperative flow measurements in gastroepiploic grafts using pulsed Doppler

OBJECTIVE

The patency of a pedicled right gastroepiploic artery (RGEA) graft can be compromised by intraoperative twists, kinks or spasms. Therefore, a systematic flow assessment was made in RGEA grafts and was compared with similar measurements made in other types of bypass conduits.

METHODS

Intraoperative pulsed Doppler flowmeter measurements obtained in a series of 556 consecutive patients undergoing at least one coronary bypass grafting onto the right coronary system were studied. Eighty-five RGEA grafts were compared with 1427 bypass grafts implanted in the same group of patients and consisted of the following conduits: 442 left internal mammary (LIMA), 149 right internal mammary (RIMA), 831 greater saphenous vein (GSV) and five inferior epigastric (EPIG) grafts. Sequential grafts were excluded from the analysis.

RESULTS

Flow measurements and Doppler waveforms were abnormal and required graft repositioning, and the addition of a distal graft or intragraft papaverine injection (only in GSVs) in 29 cases (2.0% of all grafts). These graft corrections were necessary in 5.9% RGEAs, 3.4% LIMAs, 2.0% RIMAs, and 0.7% GSVs (P < 0.001). The relative risk for graft correction was eight times higher for RGEAs than for GSVs (P = 0.002). Flow increased from 8 +/- 2 to 54 +/- 5 ml/min (P < 0.0001). Flow data were significantly influenced by the type of run-off bed (P < 0.001), the measurements obtained in grafts implanted onto the right coronary artery and the left anterior descending artery being superior. Flows in RGEAs, however, were comparable with values obtained in other grafts implanted onto the same recipient coronary artery.

CONCLUSIONS

A significantly higher incidence of graft malpositioning caused inadequate flows in RGEAs. However, normal flow values could be restored simply by assigning a better graft orientation under pulsed Doppler flowmeter control. Overall flow capacity of the RGEA did not differ from values obtained in other arterial and venous grafts implanted onto the same recipient arteries.

Recurrent supra-anastomotic aneurysm following infrarenal aortic repair

A 72-year-old woman presented with a recurrent proximal aortic true aneurysm 7 years after an abdominal aortic aneurysmectomy. It was complicated by a contained rupture into the right psoas. The repair was successfully realized through a thoraco-abdominal approach. A tube graft was interposed between the proximal aorta and the old graft, associated with the reimplantation of the renal arteries. A systemic follow-up of abdominal aortic grafts by reliable diagnostic methods is advocated to provide a timely and appropriate surgical treatment of this major complication.

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.

Noninvasive functional assessment of left internal mammary artery grafts by transcutaneous Doppler echocardiography

A noninvasive method to assess left internal mammary artery (LIMA) patency and function would be useful because this vessel is frequently used for revascularization of the left anterior descending coronary artery. The purpose of this study was to assess the feasibility of measuring changes in LIMA velocities by transcutaneous Doppler during dipyridamole-induced vasodilation. Twenty-five patients with a LIMA graft anastomosed to the left anterior descending coronary artery were studied at least 1 month after surgery by the use of a 5 MHz transducer placed in the left supraclavicular fossa. Doppler velocity parameters were measured at baseline and after intravenous administration of dipyridamole. Dipyridamole increased mean velocity by 127% +/- 54% (p < 0.001), systolodiastolic velocity time integral by 89% +/- 31% (p < 0.001), and diastolic-to-systolic peak velocity ratio from 0.7 +/- 0.3 to 1.2 +/- 0.4 (p < 0.001). The dipyridamole-to-baseline mean velocity ratio was 2.3 +/- 0.5. We conclude that it is possible to measure dipyridamole-induced changes in LIMA flow velocities and thus obtain an index of LIMA blood velocity reserve by transcutaneous Doppler echocardiography.

Long-term survival after aortic valve replacement for native active infective endocarditis

BACKGROUND

The objective of this study was to analyse the impact of acute surgery for native aortic valve endocarditis and its influence on the long-term prognosis after surgery.

METHODS

A total of 161 patients underwent aortic valve replacement for native active aortic valve endocarditis (NAAVE) during a 29-year period, from 1967 to 1995 (age range: 10 to 72 years; mean 48 +/- 12). The main indication for surgery was progressive congestive heart failure (76%). Other indications were untreatable sepsis (27%), peripheral or central emboli (12%) and, from 1978, echocardiographic evidence of friable, pedunculated vegetations (3%). Streptococcal and staphylococcal infections predominated. Concomitant procedures were performed in 27% of the patients, including mitral and tricuspid valve surgery and coronary bypass procedures.

RESULTS

Operative mortality was 8% in the majority of cases caused by heart failure or multi-organ failure. Multivariate logistic regression analysis identified NYHA class IV to be an independent predictor for postoperative death. Long-term survival for discharged patients was 75% at 10 years and 58% at 15 years, with a mortality rate of 3.6%/patient/year. Cox regression analysis identified the year of operation, trivalvular endocarditis and staphylococcal infection as independent predictors of survival. At 10 and 15 years after aortic valve replacement, 91% and 84% of the patients, respectively, were free of recurrent endocarditis. The presence of an abscess cavity at first operation was found to be predictive of recurrent endocarditis.

CONCLUSIONS

Valve replacement for NAAVE offers a good chance for a cure and satisfactory long-term survival. Improvements in pre- and per-operative management of the very ill patient, and the use of allograft valves are likely to further improve long-term results. Finally, the presence of staphylococcal endocarditis requires long-term postoperative antibiotic therapy.

[Unexpected origin of recurrent ascites: apropos of 2 cases]

The authors report the cases of two patients suffering from ascites attributed for several years to a non pericarditic aetiology. The first patient presented with a diagnosis of right cardiac failure secondary to a right myocardial infarction. Cardiac catheterisation, magnetic resonance imaging and transoesophageal echocardiogram allowed to establish the diagnosis. In the second case, ascites was attributed to cirrhosis. Presence of pericardial calcifications, visible on a chest X-Ray led to suspect constrictive pericarditis. In both cases, ascites contained a high protein level. A pericardectomy allowed a favourable outcome in both cases. Thus, a diagnosis of constrictive pericarditis must be evoked in face of ascites of unclear origin and a normal cardiac size.

Aortic allograft and pulmonary autograft for aortic valve replacement: mid-term results

Between April 1990 and August 1996, 138 patients (median age 42 years, range 10 days to 66 years) underwent aortic valve or root replacement with allografts (n = 70) or autografts (n = 68). Aortic stenosis was the main indication (80 patients, 58%) followed by aortic incompetence (31 patients, 22%). Twenty-five patients had endocarditis (18%) and two patients had truncus repair (2%). Some 140 allograft valves were inserted (70 pulmonary, 70 aortic). Most of the valves were conditioned and cryopreserved by the European Homograft Bank, Brussels, Belgium. Subcoronary implantation was performed in 46 patients, intraluminal cylinder in 29 and root replacement in 63. Peroperative transoesophageal echocardiography was routinely used. Three patients required valves replacement by mechanical valves at the time of surgery due to technical failure. Seven patients (5%) died early, while 131 were followed up from 1 to 76 months (mean 32 months). There were two late deaths. All survivors are in NYHA class I and currently free of any medication. There have been no thromboembolic events. Three patients developed endocarditis (2%). Transthoracic echocardiography was performed routinely in all patients; an initial study showed grade 1 aortic incompetence in nine patients and grade 2 in two. Late studies up to 6 years after surgery showed progression of aortic incompetence in 18 of 43 survivors with subcoronary implantation and in four of 75 survivors who underwent other techniques (P < 0.002). In congenital patients with preoperative aortic incompetence, the left ventricular function has been prospectively analysed by echocardiography. Risk factors have been identified as dilated ventricles with spherical shapes, thin wall and reduced velocities by measuring ejection fraction and velocity of shortening of myocardial fibres. Allograft and autograft replacement of the aortic valve can be performed with excellent results. Considering the risk of degeneration of allografts, and the growth potential of the pulmonary autograft, this should be regarded as the optimal method of treatment for diseased aortic valves in neonates, children and young adults.

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.

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.

Myocardial revascularization for severe left ventricular dysfunction. Factors influencing early and late survival

The results of coronary bypass surgery have been assessed in 102 patients with severe left ventricular dysfunction who had a preoperative left ventricular ejection fraction of < or = 0.35 (mean (s.e.m.) 0.29 (0.01)). Independent risk factors influencing operative mortality were obesity (P = 0.0290) and the need for preoperative intra-aortic balloon counterpulsation (P = 0.0010). Cox regression analysis using as its end-point 'cardiac-related death' demonstrated three variables; the need for preoperative intra-aortic balloon counterpulsation (P < 0.001), advanced age (P = 0.011), and obesity (P = 0.36). In a subset of 43 patients who did not have these risk factors, the 4-year cardiac-related death rate was 95.1 (3.4)%. The operative mortality and long-term survival can be expected to be satisfactory in patients with severe left ventricular dysfunction, provided they have a viable myocardium rather than myocardial fibrosis.

Retention of endothelium-dependent properties in human mammary arteries after cryopreservation

BACKGROUND

We investigated the effects of cryopreservation and antibiotic treatment on endothelium-dependent vasomotor properties of human internal mammary arteries (IMAs).

METHODS

Sixty IMA specimens from routine coronary artery bypass grafting procedures were randomly assigned to six groups. Group I (controls) were immediately tested after harvest. Remaining groups were prepared according to a stepwise design: group II, 6 hours of warm ischemia; group III, 6 hours of warm ischemia + 24 hours at 4 degrees C (without antibiotics); group IV, 6 hours of warm ischemia + 24 hours of 4 degrees C antibiotic disinfection; group V, 6 hours of warm ischemia + 24 hours at 4 degrees C (without antibiotics) + cryopreservation; and group VI, 6 hours of warm ischemia + 24 hours of 4 degrees C disinfection+cryopreservation. The IMA specimens were cut into rings and the tension of vascular smooth muscle was recorded. The IMA rings were contracted with norepinephrine (3 x 10(-6) mol/L) and tested with cumulative concentrations of acetylcholine (from 1 x 10(-9) to 1 x 10(-5) mol/L), contracted with endothelin-1 (from 1 x 10(-11) to 1 x 10(-6) mol/L), and contracted with the nitric oxide-synthase inhibitor NG-monomethyl-L-arginine (1 x 10(-4) mol/L). Rings were also tested for their capacity to generate 6-keto-prostaglandin F1 (the stable metabolite of prostacyclin), and endothelial cell viability rate was finally evaluated with the trypan blue dye exclusion method.

RESULTS

Our results show that a complete cryopreservation protocol does not significantly modify (p > 0.05) the relaxant activity to acetylcholine in norepinephrine-precontracted IMA rings (controls; 90.2% +/- 4.2% vs group VI, 77.1% +/- 6.2%) or the vasoconstrictor response induced by endothelin-1 (controls, 62.6% +/- 2.8% versus group VI, 73.7% +/- 4.8%) and NG-monomethyl-L-arginine (controls, 22.4% +/- 1.5% versus group VI, 18.9% +/- 1.9%). Furthermore, IMA cryopreservation does not significantly modify (p > 0.05) the endothelial release of prostacyclin either in basal conditions (-20% versus controls) or during pharmacologic intervention with acetylcholine (-18% versus controls), endothelin-1 (-17% versus controls), and NG-monomethyl-L-arginine (-18% versus controls).

CONCLUSIONS

We conclude that the IMA endothelial function does not seem significantly injured by any of the current steps of disinfection and cryopreservation.

Flow-mediated vasodilation during pacing of the free epigastric artery bypass graft early and late postoperatively

OBJECTIVES

The free epigastric artery bypass graft is proposed as an alternative conduit to the saphenous vein graft, known for its high rate of attrition. The aim of our study was to assess its endothelial function in vivo.

BACKGROUND

The endothelium of arterial bypass grafts plays a role in both the performance and the patency of such grafts.

METHODS

We studied 73 epigastric grafts early (mean +/- SD 10 +/- 3 days) and 36 late (12 +/- 5 months) after coronary bypass surgery with quantitative angiography at rest, after 2 min of atrial pacing (130 beats/min) and after injection of isosorbide dinitrate (1 to 2 mg) into the graft.

RESULTS

At rest, mean epigastric graft diameter was lower in the late than in the early postoperative period (2.26 +/- 0.39 vs. 2.61 +/- 0.49 mm, p < 0.001). Early after operation, epigastric grafts with a small or an intermediate runoff, but not those with a large runoff, were capable of vasodilation with nitrates (+0.09 +/- 0.10 mm). Late after operation, vasodilation after administration of isosorbide dinitrate was similar in epigastric grafts with a large runoff and in those with a small or intermediate runoff (+ 0.23 +/- 0.09 vs. +0.23 +/- 0.18 mm). Significant vasodilation during pacing was observed late (+4 +/- 9%, p < 0.01) but not early postoperatively, except in a subset of patients with grafts capable of vasodilation after nitrates. A correlation between the response to nitrates and the response during pacing was observed early (r = 0.579, p < 0.001) and late postoperatively (r = 0.530, p = 0.02).

CONCLUSIONS

Flow-mediated vasodilation during pacing was observed in most epigastric grafts late, but not early, after operation. This endothelium-dependent dilation was correlated with the importance of the vasodilation observed with nitrates (endothelium-independent), which was related to the importance of the runoff only in the early postoperative period. The ability of epigastric grafts late postoperatively to dynamically adapt their dimensions to an acute increase in demand could contribute to the good functional results of this new alternative arterial graft.

Current status of the inferior epigastric artery

The current trend is to use more arterial conduits for myocardial revascularization. The rationale for this trend is that the late patency rate of internal thoracic artery grafts has been shown to be superior to that of saphenous vein grafts. The desire to achieve complete myocardial revascularizations only with arterial conduits has led to consideration of new arteries as coronary artery bypass grafts. Recently, the inferior epigastric artery has been proposed as one of these alternative grafts. It is expected that this new conduit will provide the same advantages as the free internal thoracic artery used in similar circumstances, but this assumption has not been validated yet. This article will review the clinical experience currently gained with the use of the inferior epigastric artery as a coronary artery bypass graft.

Revascularization of the circumflex artery with the pedicled right internal thoracic artery: clinical functional and angiographic midterm results

Retroaortic crossing of the pedicled right internal thoracic artery for revascularization of the circumflex artery used in combination with a pedicled left internal thoracic artery anastomosed to the left anterior descending artery and its branches is an attractive technique to achieve an extensive arterial revascularization of the left ventricle. However, there is a suspicion that pulling the right internal thoracic artery through the transverse sinus could compromise its blood flow capacity and patency. Between January 1990 and July 1994 this technique was applied in 256 patients (202 men, 54 women; average age 62 years, range 31 to 80 years). Sixty-one patients had two-vessel disease and 195 had three-vessel disease. Seventeen patients were undergoing a reoperation. Twenty-two had a left ventricular ejection fraction of 40% or less. Thirty had diabetes. Twenty-eight had morbid obesity. The right internal thoracic artery was directed to the circumflex artery (259 anastomoses) through the transverse sinus and the left internal thoracic artery was anastomosed to the left anterior descending artery and its branches (375 anastomoses) in all patients. The 195 patients with three-vessel disease received additional coronary artery bypass grafts to the right coronary artery (93 saphenous vein grafts, 89 free inferior epigastric artery grafts, 12 pedicled right gastroepiploic artery grafts). In total, the 256 patients received 833 distal anastomoses (average 3.2, maximum 5 per patient) and 634 distal anastomoses were internal thoracic artery anastomoses (average 2.4, maximum 4 per patient). Three patients died early and eight had a nonfatal myocardial infarction. Seven patients needed postoperative intraaortic balloon pump support. Six patients underwent early reoperation because of excessive bleeding. Sternal dehiscence occurred in four patients. One of these four patients died of the complication 10 months after the operation. No patient was lost to follow-up (average 33 months). During follow-up, two sudden deaths and six noncardiac deaths occurred. Two patients had a nonfatal myocardial infarction and 12 had recurrence of angina. There were no late reoperations. One patient underwent a successful percutaneous balloon angioplasty of a native left anterior descending artery. Seventy-four patients, enrolled in prospective angiographic studies, underwent a postoperative recatheterization (average 13.2 months, range 6 to 58 months). Seventy-three of the 74 right internal thoracic artery grafts were patent. In comparison, 74 of 74 of the left internal thoracic artery grafts (106/107 anastomoses) were patent. Maximal stress thallium-201 scintigraphy results, obtained in 25 of those patients, did not reveal ischemia in the area of the circumflex artery.(ABSTRACT TRUNCATED AT 400 WORDS)

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.

Operative risk assessment in coronary artery bypass surgery, 1990-1993: evaluation of perioperative variables

Patient characteristics and the results of cardiac surgery change with time. To achieve the best possible treatment a continual analysis of results is necessary. The present study analyzes 1225 consecutive patients undergoing isolated aortocoronary bypass surgery for the four-year period ending September 1993. Average age was 63 years (range 32-86 years), 927 (75.7%) patients were male and 298 (24.3%) were female. Hospital mortality was 2.2% (17/787) for elective surgery, 6.3% (21/336) for urgent surgery, and 9.8% (8/82) for emergency surgery. Intraoperative variables increasing independently operative mortality as evidenced by multivariate analysis were the following: prolonged aortic cross-clamping time (p < 0.0001), absence of cold-blood cardioplegia (p = 0.0012), absence of bilateral use of internal mammary artery (p = 0.0035). Likewise, intraoperative variables influencing major adverse outcome (operative mortality and/or need for intra-aortic balloon pulsation) were the following: prolonged aortic cross-clamping time (p < 0.0001), absence of cold-blood cardioplegia (p = 0.0360). In conclusion, global ischemic time was the dominant variable in predicting operative outcome. Furthermore, a protective effect of cold blood cardioplegia and bilateral internal mammary artery grafting was evidenced.

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)

Functional evaluation of internal mammary artery bypass grafts in the early and late postoperative periods

OBJECTIVES

We sought to determine whether internal mammary artery grafts adapt to an increase in myocardial flow demand and whether they restore maximal flow reserve.

BACKGROUND

Although mammary grafts are now considered the graft of choice for coronary artery bypass surgery, there is still controversy about whether they can provide adequate flow at periods of peak myocardial demand.

METHODS

Of 28 patients with a mammary graft anastomosed to the left anterior descending coronary artery, 15 were studied early (mean [+/- SD] 8 +/- 2 days) and 13 late (19 +/- 15 months) after operation by quantitative angiography and selective intravascular Doppler analysis at baseline, during pacing and after injection of papaverine and isosorbide dinitrate into the graft. Eleven patients with a normal left anterior descending artery served as control subjects.

RESULTS

At baseline, mean graft diameter (2.39 +/- 0.41 vs. 2.42 +/- 0.45 mm) and bypass flow (38 +/- 22 vs. 30 +/- 12 ml/min) were similar in the early and late postoperative periods. Significant and similar vasodilation was observed in mammary grafts after administration of papaverine (+6 +/- 5% vs. +9 +/- 6%) and nitrates (+14 +/- 7% vs. +16 +/- 9%) both early and late after bypass surgery. Graft diameter increased during pacing late (+6 +/- 3%, p < 0.05) but not early after operation. Bypass flow increased similarly during pacing in both groups, but maximal flow reserve induced by papaverine was significantly lower in mammary grafts studied early (2.70 +/- 0.62) than those studied late (3.66 +/- 0.81, p < 0.01) and in normal coronary arteries (4.05 +/- 0.96, p < 0.001).

CONCLUSIONS

An increase in myocardial blood flow induced by pacing resulted in vasodilation of mammary grafts in the late but not in the early postoperative period. Significant vasodilation of mammary grafts after papaverine and isosorbide dinitrate administration was observed both early and late after operation. However, bypass flow reserve after papaverine injection was significantly lower in the early postoperative period but normalized over time. This finding seems unrelated to the conduit; rather, it appears to be related to the periphery and could be the result of injury to the microvasculature during operation.

Coronary artery bypass grafting with the inferior epigastric artery. Midterm clinical and angiographic results

Between December 1988 and September 1993, 157 patients (141 men, 16 women, average age 60.2 years, range 37 to 78 years) underwent a complete myocardial revascularization with 157 inferior epigastric artery grafts and 285 internal mammary artery grafts (281 in situ, 4 free grafts). A total of 543 distal arterial anastomoses (average 3.4, range two to five per patient) were constructed, 376 with the internal mammary artery and 167 with the inferior epigastric artery. The inferior epigastric artery grafts were anastomosed to two left anterior descending, 5 diagonal, 34 circumflex, and 126 right coronary arteries. The indications for the use of the inferior epigastric artery were the unavailability of conventional conduits in 56 patients and a favorable anatomy or a young age in 101 selected patients. The clinical follow-up averages 31.8 months (range 6 to 62 months). Four patients died early, and there were three perioperative nonfatal myocardial infarctions. Eight patients required early reoperation for thoracic bleeding (2) or drainage of an abdominal parietal collection (6). There were four late deaths (2 sudden deaths, 2 noncardiac causes) and one nonfatal myocardial infarction. Angina recurred in nine patients, of whom one required reoperation and three underwent successful percutaneous balloon angioplasty of a native coronary artery (2) or an old saphenous vein graft (1). An early recatheterization was obtained before discharge (average 11 days) in 135 patients: 132 of 135 inferior epigastric artery grafts were patent. Seventy-seven patients underwent a second angiographic restudy 6 to 43 months after the operation. Forty-four of the 48 inferior epigastric artery grafts restudied within the first postoperative year (average 8.5 months) were patent, but eight showed a diffuse narrowing. Twenty-eight of the 29 inferior epigastric artery grafts examined angiographically between 13 and 43 months (average 25 months) were open, and among those 29, 25 were widely patent, perfectly matching the receiving coronary artery. Most of the occluded or narrowed inferior epigastric artery grafts were grafted onto coronary arteries with mild stenosis at restudy. Five patients underwent a third angiographic reexamination up to 60 months after the operation (average 39 months). All five inferior epigastric artery grafts were widely patent. The early attrition rate of the inferior epigastric artery, as for any free arterial graft, is probably the result of both the loss of a true pedicle and the need for constructing an additional proximal anastomosis. The fact that the patency rate of the inferior epigastric artery graft seems to remain stable beyond 1 year could suggest a good durability in the future.

Peroperative hemodynamic study of left internal mammary artery grafts

The present study was undertaken to analyse hemodynamic features of an arterial graft and to determine parameters which influence primarily flow and velocity. A total of 284 consecutive patients having isolated coronary bypass surgery underwent peroperative hemodynamic assessment by pulsed Doppler ultrasonics of a left internal mammary artery bypass graft implanted onto the left anterior descending artery. Internal mammary artery free flow was 109.2 +/- 3.7 ml/min and flow in the internal mammary artery measured after completion of the distal anastomosis was 70.9 +/- 2.7 ml/min. All values quoted are mean +/- standard error of the mean. Mean velocity was 21.2 +/- 0.6 cm/sec, internal diameter was 2.65 +/- 0.04 mm and pulsatility index was 2.24 +/- 0.12. Resistance was expressed as mmHg/(ml . min-1) and averaged 1.65 +/- 0.13 for total resistance, 0.87 +/- 0.05 for graft resistance, and 0.73 +/- 0.13 for coronary resistance. From a set of 35 variables, stepwise multiple regression analysis selected two parameters influencing independently flow in internal mammary artery (R2 = 0.8762): flow velocity (p < 10(-4)) and internal diameter (p < 10(-4)). Variables influencing velocity (R2 = 0.3071) were: pulsatility index, which is a dimensionless expression of peripheral resistance (p < 10(-4)), and free internal mammary artery flow (p = 0.0007). Furthermore, a significant correlation between internal diameter and total resistance was observed (R = -0.5363, p < 10(-4), Y = 1.676X-1.545), and the exponentially fitted regression line was characterized by a marked increase of resistance at diameters less than 2 mm.(ABSTRACT TRUNCATED AT 250 WORDS)

Quantitative angiographic follow-up study of the free inferior epigastric coronary bypass graft

BACKGROUND

Attempts to improve late results of bypass coronary surgery have focused on the use of arterial conduits because of the high attrition rate of venous grafts.

METHODS AND RESULTS

In our institution, 150 patients received an inferior epigastric artery (EPIG) as a free bypass graft, anastomosed to the right coronary artery in 73% and to a marginal branch in 20% of cases. These patients were followed prospectively by qualitative and quantitative angiography. Angiographic studies were performed in 122 patients (81%) early after surgery (11 +/- 5 days), and in 72 cases, a late evaluation (11 +/- 6 months) was also obtained. Quantative angiography (basal and after isosorbide dinitrate [ISDN]) was performed on the in situ EPIG in a large subset of these patients, as well as in 59 patients before bypass surgery. The patency rate was 98% at early control and remained high (93%) at late control. However, at late control, 14 EPIGs were occluded or threadlike, but of these 14, eight were grafted on a coronary artery with a moderate stenosis (< or = 60%) and with good anterograde perfusion. Mean basal EPIG diameter increased from 2.23 +/- 0.42 mm before surgery to 2.57 +/- 0.52 mm at 11 days (P < .01) but decreased to 2.20 +/- 0.47 mm in late study (P < .01 versus 11 days and P = NS versus before surgery). Vasodilation of EPIG with ISDN was observed before surgery (+0.34 +/- 0.20 mm, P < .001) and at late control (+0.20 +/- 0.17 mm, P < .001) but not in the early postoperative period for the whole group. Early after surgery, basal diameter was not different from native EPIG dimensions after ISDN (2.57 +/- 0.52 versus 2.56 +/- 0.39 mm), suggesting maximal dilation. However, vasodilation with ISDN was observed in a subgroup of patients at this time. These responder patients (n = 51) had a smaller basal diameter (2.47 +/- 0.49 versus 2.67 +/- 0.54 mm, P < .05) and a smaller runoff (P < .001) than nonresponder patients.

CONCLUSIONS

EPIG grafts have a good early patency rate. The mid-term patency rate remains high and seems to depend, at least partially, on flow through the native coronary artery. EPIGs initially increase their lumen size, probably to meet the increased blood flow due to myocardial requirements. Over time, EPIG diameters decrease mainly as a result of a higher basal vasomotor tone. Long-term angiographic follow-up (eg, 5 to 10 years) is needed to assess late patency rate and the relation with these early findings and will define the place of this new coronary bypass conduit.

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.

Doppler flow measurement in coronary artery bypass grafts and early postoperative clinical outcome

The present investigation attempts to correlate flow measurements made intraoperatively in coronary bypass grafts with clinical outcome. A total of 352 consecutive patients undergoing isolated coronary artery surgery underwent hemodynamic assessment of their bypass grafts (328 internal thoracic artery and 582 saphenous vein grafts) at the end of cardiopulmonary bypass (CPB) by using a 8 MHz pulsed Doppler ultrasound flowmeter. The total patient population was divided into three groups of distinct outcome (A: normal, 228 patients; B: complicated, 106 patients; C: poor, 18 patients) on the basis of a combination of the following parameters: difficult weaning from bypass, use of inotropic drugs, reduced left-ventricular stroke work index, myocardial infarction, intraaortic balloon counterpulsation, and death of cardiac origin. Univariate analysis has shown clinical outcome to be influenced by preoperative clinical condition and not by flow in bypass grafts (average flow per graft [ml/min] was 60 +/- 2 [mean +/- SEM] in group A, 58 +/- 3 in group B and 43 +/- 6 in group C: NS by analysis of variance). Multivariate analysis (Fisher linear discriminant analysis) selected only the two following factors leading to normal (group A) or adverse (groups B and C) outcome: unstable angina (p = 0.026) and duration of additional CPB after unclamping the aorta (p < 10(-5). To conclude, clinical outcome was not influenced by flow as measured in well-functioning bypass grafts by pulsed Doppler technique.

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)

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.