Cardiovascular surgery (London, England)最新文献

Since elderly patients are being referred for surgery in increasing numbers, we reviewed the clinical outcome of 459 consecutive patients aged 70 to 89 years, who had aortic valve replacement between 1993 and 2000. We subdivided the study population into three groups: in Group 1 we included patients aged 70–74 years old; in Group 2 patients aged 75–79 years old; and in Group 3 patients aged 80 years old or older.

An isolated AVR was performed in 289 patients (63%), concomitant coronary artery bypass graft (CABG) in 168 patients (36.6%), an isolated ventricular septal defect (VSD) closure in one patient (0.2%) and an isolated atrial septal defect (ASD) closure in one patient (0.2%). The overall perioperative mortality rate was 7% (32 patients), without significant differences among the three groups (P=0.88).

Our study confirms the good outcome of aortic valve replacement in elderly patients even in octagenarians and only concomitant CABG procedures increase the operative risk, reducing long-term survival (P<0.05).

Objective: Recent studies have demonstrated that the induction of heat shock protein-72 (HSP72) by different stimuli preserves the heart function after cardioplegic arrest. Based on these findings, we investigated whether intermittent warm blood cardioplegia would induce changes in the myocardial expression of HSP72.

Methods: Forty patients scheduled for aortocoronary bypass were randomly assigned to receive either cold or warm intermittent blood cardioplegia. In all patients HSP72 and HSP72 mRNA were assayed in biopsies from the right atrium at baseline, and during the reperfusion period. Plasma CK-MB and troponin-T, and myocardial oxygen extraction and lactate release were also measured.

Results: In both groups, myocardial expression of HSP72 increased throughout the reperfusion period, but the values of HSP72 band lengths were significantly higher in the warm group. Correspondingly, HSP72 mRNA levels increased progressively in both groups, with significant difference between groups observed in biopsies at the reperfusion. Warm blood cardioplegia was associated with lower levels of CK-MB and troponin-T. Myocardial oxygen extraction and lactate release were higher during intermittent warm cardioplegia, indicating a more profound ischemic anaerobic metabolism in the warm group.

Conclusions: Intermittent warm blood cardioplegia induces an increased expression of HSP72 and it is associated with a better myocardial protection, by a mechanism involving a variant of the classical ischemic preconditioning model.

The purpose of this study was to investigate the effect of N-acetylcysteine (NAC) on spinal cord ischemia–reperfusion (I–R) in rabbits. Thirty rabbits were divided into five equal groups, group I (sham-operated, no I–R), group II (control, only I–R), group III (I–R+NAC), group IV (I–R+hypothermia), group V (I–R+NAC+hypothermia). Spinal cord ischemia was induced by clamping the aorta both below the left renal artery and above the aortic bifurcation. Forty-eight hours postoperatively, the motor function of the lower limbs was evaluated in each animal according to Tarlov Score. Spinal cord samples were taken to evaluate the histopathological changes. The sham-operated rabbits (group I) showed no neurologic deficit (Score=4). Paraplegia (Score=0) developed in all rabbits in the control group (group II). Administration of 50 mg/kg of NAC (group III) resulted in significant reduction of motor dysfunction (Score=3.1±1.3, p=0.002). Application of hypothermia alone (group IV) showed significant recovery of motor functions (Score=3.0±1.1, p=0.002), and combination of hypothermia and 50 mg/kg of NAC (group V) showed complete recovery of lower limb motor function (Score=4, p=0.001). Histologic examination of the spinal cord in rabbits with paraplegia revealed several injured neurons. The cords of animals with no motor function deficits showed only minimal cellular infiltrates in the gray matter, and there was good preservation of nerve cells. NAC showed protective effects of the spinal cord. Moderate hypothermia alone also showed protective effects. Combined use of NAC and hypothermia resulted in highly significant recovery of spinal cord function.

The optimum day for discharge after coronary artery bypass graft (CABG) surgery has been subject to some debate yet there has been a steady increase in the number of patients discharged within 5 days of surgery. Delayed discharges may result in the under use of surgical capacity and impact upon patient outcomes.

The author conducted a retrospective; correlational study of 333 patients to investigate the variables associated with delayed discharge after CABG. The results suggest it is possible to identify patients likely to achieve a 5-day discharge from their age and Parsonnet score [Circulation, 79(Suppl. I), 1989, 3]. The introduction of a policy of adopting a 5-day discharge for those patients could maximise surgical capacity and improve patient outcomes. Further prospective study is recommended after the policy has been implemented to evaluate the effectiveness of age and Parsonnet score to predict a 5-day discharge.

The role of radial artery as an arterial conduit for myocardial revascularisation is well established. Minimally invasive approaches for the harvesting of conduits are desirable for clinical and cosmetic reasons. We report our experience with two techniques of endoscopic radial artery harvesting. The techniques are illustrated and their relative advantages discussed.