Should the aortic valve be replaced in patients with mild aortic stenosis admitted for coronary surgery?

BACKGROUND: The question whether the aortic valve in patients with mild aortic stenosis undergoing coronary artery bypass grafting (CABG) should be replaced or left alone is still controversial. METHODS: Between 01/1995 and 03/2004, 38 patients (30 male, 8 female, mean age 70.9 +/- 7.8 years) required redo AVR 7.1 +/- 4.8 years after primary CABG, while 202 patients (125 male, 77 female, mean age 72.7 +/- 7.8 years) underwent combined AVR and CABG (1.9 +/- 0.8 grafts/patient). To evaluate the different approaches, the data of the redo-AVR group were compared with the data of a propensity-score matched group of AVR + CABG patients. RESULTS: All patients survived the procedure; the 30-day survival was 94.7 % in both groups. The 1- and 5-year survival rates were 94.7 % and 83.8 % in the AVR after CABG group, and 94.7 % and 86.9 % in the AVR + CABG group, respectively. The late mortality was 28.9 % in the AVR after CABG and 25 % in the AVR + CABG group. Statistically, significant differences regarding perioperative mortality and morbidity could not be detected, neither with nor without propensity score analysis. CONCLUSION: Combined AVR and CABG in patients with coronary artery disease and mild to moderate aortic stenosis seems advisable in an institution with an equally low perioperative risk for both procedures, because the patient will need only one surgical procedure instead of undergoing surgery with all the associated risks twice.

The effects of interrupted or continuous administration of sevoflurane on preconditioning before cardio-pulmonary bypass in coronary artery surgery: comparison with continuous propofol.

Volatile anaesthetics have been shown to exert cardioprotective properties in experimental and clinical studies. However, the mode of administration may influence these cardioprotective effects. The present study was designed to compare the effect of interrupted administration of sevoflurane before cardiopulmonary bypass with continuous sevoflurane administration and with propofol-only anaesthesia, on cardioprotection as assessed by left ventricular performance and myocardial cell damage during coronary artery bypass grafting. Forty-two patients scheduled for coronary bypass surgery were randomly assigned to one of three groups: propofol-only (P; n = 14), continuous (SevoC; n = 14) and interrupted sevoflurane administration (SevoI; n = 14). Myocardial cell damage as assessed by Troponin T (cTNT) and creatine kinase MB (CK-MB) were chosen as the primary endpoints and echocardiographic myocardial performance index (MPI) measurements were also performed. Up to 48 h postoperatively, in group SevoI, postoperative cTNT values (mean (SD) 0.13 (0.04) ng x ml(-1)) were significantly (p < 0.05) lower than both the P (0.26 (0.31) ng x ml(-1)) and SevoC (0.25 (0.17) ng x ml(-1)) groups. CK-MB levels were also significantly (p < 0.05) lower in the SevoI group at 24 h after surgery and MPI significantly improved compared with both the P and SevoC groups. There was, however, no difference with respect to cytokine release and length of stay in either the intensive care unit or in the hospital. We conclude that prior interrupted sevoflurane administration confers some cardioprotection as compared with continuous sevoflurane administration or propofol-based anaesthesia.

[Arterial grafts in coronary surgery for diabetic patients]. / Koronare Revaskularisation bei Diabetikern--Stellenwert von arteriellen Grafts.

Surgical revascularization allows especially for the diabetic patient with coronary multi-vessel disease a superior long-termperspective compared to percutaneous coronary interventions. However, the specific advantages and also risks associated with the expanded use of arterial grafts as coronary conduits in diabetics are not clearly answered. A systemic analysis of the current literature underlines the following statements: The radial artery is, compared to the internal mammary artery, to a higher extent prone to atherosclerosis, especially in diabetic patients. Better long-term survival for patients with bilateral IMA-grafts has also been assessed for diabetic patients. The risk of thoracic wound infections is not obligatory increased for diabetics with double IMA-grafts. Revascularization with radial arteries can be performed with low perioperative risks. Long-term results or studies on radial artery bypass grafting especially in diabetics are not available. In our own experience (3,548 isolated coronary operations, 01/2001 until 05/2005), diabetic patients have no increased perioperative mortality, even when using more complex arterial grafting. Conclusively, diabetic patients should also significantly benefit from the use of the second mammary artery. Regarding conduit quality, a second IMA appears favorable over the radial artery.

Immediate postoperative extubation after minimally invasive direct coronary artery surgery (MIDCAB).

We were interested whether immediate postoperative extubation and early discharge of the intensive care unit (ICU) is safe in minimally invasive direct coronary artery surgery (MIDCAB) patients. Therefore we retrospectively analyzed the data from 217 patients undergoing MIDCAB from 2/99 to 4/02. Immediate postoperative extubation was possible in 182/217 (83.9%) with eight patients needing reintubation (11.5+/-3.3 h). Ventilation time of the remaining 35 patients was less than 24 h in 31 patients (8.8+/-5.3). Sixty-nine patients (31.8%) were directly transferred from the ICU. Immediate extubation after MIDCAB surgery is safe resulting in an effective use of resources.

Correction of tetralogy of Fallot: does the time period of surgery influence the outcome?

BACKGROUND: The perioperative outcome of patients with tetralogy of Fallot (TOF) seems to have improved over the last four decades. METHODS: To prove this hypothesis, we retrospectively analysed the data of 269 TOF patients operated on between 1975 and 1999 in our institution. RESULTS: Over the years, younger patients (median age 1975 - 1980: 4.5 years, 1995 - 1999: 0.9 years) were operated on with a lower mortality (1975 - 1980: 8.6 %, 1995 - 1999: 2.4 %). Residual defects such as pulmonary stenosis or insufficiency and VSD occurred with a similar frequency over time, whereas rhythm disturbances were significantly reduced (1981 - 1985: 51.2 %, 1995 - 1999: 24.4 %, p = 0.012). Postoperative length of hospital stay was significantly (p < 0.05) shorter in the years 1995 - 1999 (11.0 - 11.4 days) than in 1975 - 1980 (16.9 +/- 16.5 days). CONCLUSIONS: Over time periods, there was a trend towards lower mortality and towards operating on patients in a younger age. The rate of rhythm disturbances and the LOS after surgery proved to be reduced during the last decade. These differences did not turn out to be statistically significant. Therefore, we conclude that the time period of surgery has only little impact on the early outcome of patients after definitive correction of TOF.

Low-potassium dextran solution ameliorates reperfusion injury of the lung and protects surfactant function.

OBJECTIVE: This study was designed to compare the effect of lung preservation with low-potassium dextran solution and Euro-Collins solution on reperfusion injury and surfactant function by using an in situ model of warm ischemia. METHODS: The left lungs of 6 minipigs were selectively perfused with Euro-Collins solution. In an additional 6 animals low-potassium dextran solution was used for flush perfusion. After 90 minutes of warm ischemia, the lungs were reperfused, and the contralateral pulmonary artery and bronchus were clamped. Hemodynamic and respiratory measurements were obtained for 7 hours of reperfusion. Surface tension of bronchoalveolar lavage and surfactant small and large aggregates were determined before perfusion (right lung) and after 2 hours of reperfusion (left lung). RESULTS: In the group receiving Euro-Collins solution, right heart failure developed within 215 +/- 39 minutes of reperfusion. An increase in minimal surface tension (P =.03), surfactant small aggregates/large aggregates ratio (P =.003), and bronchoalveolar lavage protein content (P =.012) were found after 2 hours of reperfusion. In the group receiving low-potassium dextran solution, all minipigs survived (P =.0001). Dynamic lung compliance (P =.034) and oxygen tension/inspired oxygen fraction ratios were higher (P =. 0001). Lung water content was lower (P =.049). The increase of minimal surface tension (P =.02) and bronchoalveolar lavage protein concentration (P =.015) were significantly less. CONCLUSION: Preservation of the lung with Euro-Collins solution leads to a reduction of physical surfactant function during reperfusion. Low-potassium dextran solution protects surfactant function and metabolism, thereby reducing reperfusion injury of the lung.

[Primary leiomyosarcoma of the pulmonary artery--a case report]. / Primäres Leiomyosarkom der Pulmonalarterie--eine Fallbeschreibung.

A case of a primary pulmonary leiomyosarcoma originating in the right pulmonary artery in a 61-year-old woman is reported. Patient's complaints were non-specific and after non-invasive diagnostics a chronic thromboembolic event was suspected to have occurred a long time ago. During a heart catheter investigation prior to planned surgical embolectomy a small specimen was taken from the pulmonary artery. Histological examination revealed malignant the tumour and by immunohistological staining its smooth muscle differentiation was confirmed. Complete resection of the tumour was achieved by radical surgery, including pneumonectomy and extensive resection of pulmonary vessels with subsequent implantation of a Goretex prosthetic. There was no evidence of recurrence or metastasis of the primary leiomyosarcoma of the pulmonary artery in a 14-month follow-up period after operation.

[Experimental xenogenic lung transplantation]. / Experimentelle xenogene Lungentransplantation.

Lung transplantation has become a valuable therapeutical option for patients with end stage vascular and parenchymal pulmonary disease. The main limitation is the donor organ shortage, which is for lung transplantation even more pronounced than for other solid organs. Therefore, the search for alternative sources in the field of xenotransplantation as potential bridging to human allograft transplantation has emerged over the last few years. Pulmonary xenotransplantation at this stage is still an experimental procedure. Different concordant and discordant models have been investigated for specific organ functions, but in subhuman models no long-term function could be achieved to date. The purpose of this article is to present recent results in pulmonary xenotransplantation models.

Exogenous surfactant improves survival and surfactant function in ischaemia-reperfusion injury in minipigs.

Reperfusion injury is the major cause of early morbidity and mortality after lung transplantation. This complication has been experimentally linked to dysfunction of pulmonary surfactant. Therefore, the hypothesis that reperfusion injury might be preventable by exogenous surfactant treatment was tested. Left lungs of minipigs were exposed to 120 min of ischaemia, and the lungs were then reperfused for up to 7 h. Animals were divided into a control group and a surfactant group (n=5 each). The surfactant group received 50 mg x kg(-1) Alveofact intrabronchially via a bronchoscope at the beginning of the ischaemic period. Bronchoalveolar lavage was performed at baseline before ischaemia and 90 min after reperfusion. Surfactant treatment significantly improved short-term survival. Pulmonary vascular resistance increased markedly in control animals leading to right heart failure and death within 3 h after reperfusion whereas the surfactant-treated animals survived the 7 h observation period. After reperfusion, alveolar accumulation of neutrophils and exuded proteins was present in both groups to the same extent. Surfactant activity after reperfusion deteriorated markedly in the control group but was preserved in the surfactant group. In conclusion, early surfactant treatment alleviates the deterioration of surfactant function and improves survival in this minipig model of ischaemia-reperfusion injury.

Ten year survival after heart transplantation: palliative procedure or successful long term treatment?

OBJECTIVE: To investigate the long term outcome and prognostic factors after heart transplantation. SETTING: University hospital. SUBJECTS: 120 heart transplant patients (98 male, 22 female; underlying disease: dilated cardiomyopathy in 69, coronary artery disease in 42, miscellaneous in nine) who had undergone heart transplantation between October 1984 and October 1987. Immunosuppressive treatment was comparable in all patients and rejection episodes were treated in a uniform manner. METHODS: Functional status, quality of life, and potential predictors for long term survival were investigated. RESULTS: Actuarial survival rates were 65% at five years and 48% at 10 years; 58 patients survived > 10 years. The major causes of death were cardiac allograft vasculopathy (39%), acute rejection (18%), infection (11%), and malignancy (11%). Long term survivors had good exercise tolerance assessed by the New York Heart Association classification: 47 (81%) in grade I/II; 11 (19%) in grade III/IV. Echocardiography showed good left ventricular function in 48 patients. On angiography, severe allograft vasculopathy was present in only 16 patients (28%). Renal function was only slightly impaired, with mean (SD) serum creatinine of 148.5 (84.9) micromol/l. Multiple potential predictors of long term survival were analysed but none was found useful. CONCLUSIONS: Heart transplantation represents a valuable form of treatment. Survival for more than 10 years with a good exercise tolerance and acceptable side effects from immunosuppression can be achieved in about 50% of patients.

Influenza vaccination in heart transplant recipients.

Seventy-nine heart transplant recipients were vaccinated with a trivalent influenza virus vaccine 1996/97 containing the strains A/Singapore/6/86 (H1N1), A/Wuhan/395/95 (H3N2), and B/Beijing/184/93. The proportions of patients with protective levels of antibody (HI > or = 40) after vaccination ranged from 100% (A/Singapore [H1N1]) to 31.6% (B/Beijing) and their mean fold titer increases were lower than those recorded for vaccination of 109 healthy subjects with the same batch of vaccine. The vaccinations were tolerated well and did not result in serious side effects, such as graft rejections. Our findings indicate that influenza vaccination can induce protective antibody levels in a substantial proportion of heart transplant recipients and lend support to the recommendation to vaccinate such patients annually against influenza.

ON-X bileaflet valve in aortic position--early experience shows an improved hemodynamic profile.

BACKGROUND: Despite considerable progress during the last decades, mechanical heart valves still have significant disadvantages in performance compared to native valves. To optimize the hemodynamic profile, a new mechanical bileaflet valve (ON-X) was developed and introduced in 1997. It was the aim of this study to assess the feasibility, safety, and the early postoperative hemodynamics with this new valve in vivo. METHODS: We analyzed 19 patients (11 male, 8 female; 63.2 +/- 8.2 years; aortic stenosis: n = 13; aortic incompetence: n = 2; combined aortic lesion: n = 2), undergoing aortic valve replacement with this prosthesis (valve size 19 mm: n = 1; 21 mm: n = 6; 23 mm: n = 8; 25 mm: n = 4; additional CABG: n = 4). In addition to intraoperative pressure gradient measurements, echocardiography was performed early postoperatively and after 3 months, evaluating pressure loss, effective orifice area, and regression of left-ventricular hypertrophy. RESULTS: No major perioperative complications were observed. The echocardiographic evaluation demonstrated a significantly increased effective orifice area and lower transvalvular gradients in all valve sizes compared with literature values for the St. Jude Medical prosthesis. Effective regression of left-ventricular hypertrophy (-23.6%) was observed over the first three months. CONCLUSIONS: These preliminary data confirm the favorable hemodynamic characteristics of the ON-X valve as compared to standard bileaflet designs. Implantation was feasible and safe, and no major postoperative complications such as thrombembolic events were observed.