Resynthesis of sternal dehiscence with autologous bone graft and autologous platelet gel.

Postoperative management of sternal dehiscence requires the organised effort of a multidisciplinary medical team, including orthopaedic surgeons, plastic surgeons, microbiologists, critical care nurses and rehabilitation experts. Clinical care of this complication impacts heavily on health-care costs, length of hospital stay, and the time to full recovery and return to regular work activity. There are various surgical approaches to sternal resynthesis, but they are often unsuccessful. In this paper, we describe the case of a 67-year-old male complaining of chronic pain due to sternal dehiscence after coronary artery bypass grafting surgery. We first report a technique for sternal resynthesis, performed in the cardiac surgery setting, using a combination of autologous bone graft and autologous platelet-derived gel (APG), and describe its postoperative management and outcome. The four-month follow-up was uneventful and a CT scan confirmed full healing of the nonunion site with solid bridging bone.

Evaluation of ear function after cardiopulmonary bypass with otoacoustic emissions: a pilot study.

OBJECTIVES: During extracorporeal circulation (ECC) there is a great hemodynamic stress with possible impact on the microcirculation, including cochlear one. Previous studies have evaluated the effect of ECC on inner ear with contrasting results. The aim of this study is to evaluate possible modifications of the outer hair cells (OHC) function after open heart surgery (OHS) under ECC with transient evoked (TEOAEs) and distortion product otoacoustic emissions (DPOAEs). METHODS: Ten patients (5 F and 5 M), undergoing OHS with ECC, were subjected to an audiological assessment pre- and postoperatively. We compared the pre-operative and post-operative mean auditory thresholds, mean TEOAEs reproducibility and amplitude, and mean DPOAEs amplitude. Student's t-test was used to compare different values. RESULTS: No significant differences were found between pre- and post-operative audiological assessment both in hearing level and in otoacoustic emissions. CONCLUSION: OHC function seems to be not affected by hemodynamic stress induced by ECC. Further studies on a larger scale will be necessary to confirm our preliminary data.

Intermittent warm blood cardioplegia induces the expression of heat shock protein-72 by ischemic myocardial preconditioning.

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.

Simvastatin attenuates leucocyte-endothelial interactions after coronary revascularisation with cardiopulmonary bypass.

OBJECTIVE: To investigate the effects of preoperative simvastatin treatment on leucocyte-endothelial interactions following coronary artery bypass surgery with cardiopulmonary bypass. DESIGN: Double blind crossover study. Experiments on polymorphonuclear cells (neutrophils) were done at the end of cardiopulmonary bypass and one hour postoperatively. Endothelial P-selectin expression and neutrophil/endothelial adhesion were evaluated under either normoxic or hypoxic conditions. SETTING: University hospital (tertiary referral centre). PATIENTS: Three groups of patients undergoing coronary bypass surgery: 20 patients taking simvastatin for cholesterol control, 16 patients not responsive to simvastatin, and 20 controls. MAIN OUTCOME MEASURES: Expression of neutrophil CD11b and endothelial P-selectin; adhesion of neutrophils to endothelium. RESULTS: Cardiopulmonary bypass resulted in a significant increase in neutrophil CD11b expression in all groups. Similarly, the exposure of saphenous vein to hypoxia/reoxygenation induced an augmentation of endothelial P-selectin. However, both neutrophil CD11b expression and endothelial P-selectin exocytosis were less in the simvastatin groups than in the controls. Cardiopulmonary bypass and controlled hypoxia/reoxygenation stimulated neutrophil/endothelial adhesion, but the number of adhering cells was less in the simvastatin groups than in the controls, irrespective of the cholesterol concentration. Treatment of endothelial cells with L-NAME completely reversed the effects of simvastatin. CONCLUSIONS: Pretreatment with simvastatin reduces neutrophil adhesion to the venous endothelium in patients undergoing coronary surgery, irrespective of its efficacy at lowering cholesterol concentration.

Pseudoaneurysm of the thoracic aorta in patients with human immunodeficiency virus infection.

Arterial pseudoaneurysm has been reported as a possible complication of immunodeficiency virus infection. We report two cases of HIV-positive patients with a pseudoaneurysm at the level of the descending thoracic aorta. The first patient refused surgery and has been followed up to 14 months, whereas the second patient underwent successful surgical repair. The importance of magnetic resonance imaging in the diagnosis of thoracic aorta pseudoaneurysm is also discussed.

Plasma levels of atrial and brain natriuretic peptides as indicators of recovery of left ventricular systolic function after coronary artery bypass.

OBJECTIVE: The purpose of this study was to investigate the effectiveness of atrial and brain natriuretic peptides (ANP and BNP, respectively) as indicators of recovery of left ventricular (LV) function after coronary surgery. METHODS: We measured the concentrations of these peptides in 31 patients with poor LV function (ejection fraction, EF<35%) undergoing coronary artery bypass, and evaluated their correlation with the echocardiographic indexes of LV function. RESULTS: Pre-operatively, the plasma levels of both ANP and BNP were markedly higher in coronary patients than in normal control subjects, and strongly correlated with both EF (BNP: r=-0.8, P<0.001; ANP: r=-0.6, P<0.001) and wall motion score index (WMSI). At post-operative follow up, plasma levels of both natriuretic peptides were markedly reduced compared with pre-operative values in 21 patients. In addition, the post-operative-pre-operative differences of BNP (Delta(BNP)) and ANP (Delta(ANP)) plasma levels strongly correlated with the differences of both EF (r=-0.7, P<0.0001 vs. Delta(BNP); r=-0.6, P=0.0003 vs. Delta(ANP)) and WMSI (r=0.6, P=0.002 vs. Delta(BNP); r=0.6, P=0.04 vs. Delta(ANP)). Finally, by logistic regression analysis, BNP appeared a significant predictor of LVEF recovery after surgery. CONCLUSION: Plasma levels of ANP and BNP might be used in routine clinical practice as a support to echocardiography in detecting recovery of the LV function after coronary surgery.

Surgical myocardial revascularization (CABG) in patients with pulmonary disease: beating heart versus cardiopulmonary bypass.

BACKGROUND: Adverse effects on the respiratory system can be severe in many instances after coronarv artery bypass grafting (CABG) with cardiopulmonary bypass (CPBP). Recently, operative techniques without CPBP have gained widespread consent, thanks to the newly developed retractors that allow satisfactory immobilisation of the surgical field. METHODS: Thirty-seven patients operated upon in our Institution between April 1997 and April 1998 showed an obstructive and/or restrictive pulmonary disease. Twenty-one patients were operated on without CBPB (group A), while 16 patients were operated using CPBP (group B, control). The allocation in each group had been randomised. RESULTS: The length of the operation in group A was less than in group B (196+/-35 minutes vs 235+/-60 minutes), (p=0.014). A significant difference was found in postoperative bleeding: 562+/-381 ml vs 776+/-378 (p=0.046), in postoperative red cell count, hemoglobin level and Hct. Permanence on the ventilator was 19.1+/-13 hours in group B and 13.1+/-6.1 hours in group A (p=0.03). The length of stay in ICU was significantly different: 33.8+/-16.2 hours for group A vs 53.6+/-29.3 hours for group B (p=0.01). No respiratory failure occurred in group A; two patients experienced slow weaning from ventilation assistance and one died from that complication in group B. CONCLUSIONS: Myocardial revascularization without CPBP allows a better postoperative clinical course in patients with advanced pulmonary disease.

Duromedics original prosthesis: what do we really know about diagnosis and mechanism of leaflet escape?

The Edwards-Duromedics (ED) is a bileaflet pyrolitic carbon mechanical valve introduced by Hemex Scientific Inc in 1982, subsequently acquired by Baxter Healthcare Corp, withdrawn from the market in 1988, and modified and reintroduced in 1990. From 1982 to date, 46 cases of leaflet escape have been registered by the manufacturer of an estimated total of 20,000 valves implanted. Disc embolization 12 years after an ED mitral prosthesis implantation is reported in a 45-year-old man operated on when he was in cardiogenic shock because a preliminary transthoracic Doppler echocardiography did not show malfunction of the valve. A correct diagnosis was made four days after the onset of the symptoms by transesophageal echocardiography. During the operation, the posterior leaflet of the ED valve was not found, a 29 mm St Jude Medical bileaflet mechanical prosthesis was implanted and the patient died in the intensive care unit because of low cardiac output syndrome. Cavitation damage is generally considered the most frequent mechanism in cases of such fracture. Thus, any patient with a mechanical valve presenting with acute pulmonary edema must be immediately transferred to a surgical unit; cinefluoroscopy or transesophageal echocardiography may be performed rapidly to achieve successful management of patients with leaflet embolization.

Open chest myocardial biopsy: a simple and safe method.

The authors describe a simple method to perform left ventricular biopsies during open heart surgery. An automatic gun shaped device is used by one hand of the surgeon: the sample is obtained in a few seconds, at any time of the surgical procedure. It consists of a transmural piece of tissue, averaging 18 mm3 in quantity. The device has been used in 20 patients who underwent coronary artery revascularization. All the biopsies were successful. No complications occurred.

[Surgical revascularization in acute myocardial infarction]. / La rivascolarizzazione chirurgica nell'infarto miocardico acuto.

Surgical treatment of acute myocardial infarction (AMI), while pathogenetically impeccable, has severe limitations in the time factor. Outside of clinical-experimental situations in some pilot-centers, operation for AMI are performed in case of accidents post-PTCA, in patients already hospitalized in cardiology or cardiac-surgery wards, or in case of post-infarction complications. The results in 10 cases of emergency revascularization for AMI after PTCA (2 deaths), 36 cases of AMI treated in hospitalized patients (4 deaths), and 24 septal ruptures (12 deaths) are reported. AMI can be favourably treated surgically, with the aid of modern cardioplegic and reperfusion techniques, if the operation is performed early, and complete revascularization is achieved.

Pacemaker malfunction due to subcutaneous emphysema--a case report.

The authors describe a cas of pacemaker malfunction due to a critical increase of impedance resulting from air entrapment in the pacemaker pocket.

Effect of complete cardiac denervation on atrial natriuretic factor release in baboons.

We investigated the influence of cardiac innervation on atrial natriuretic factor (ANF) release in baboons. For this purpose, plasma ANF levels were measured in control conditions and in response to head-down (-45 degrees) and head-up tilt (+45 degrees) in six anesthetized baboons before and after complete cardiac denervation obtained by orthotopic autotransplantation of the heart. Cardiac denervation did not modify baseline plasma ANF levels (60.4 +/- 17 pg/ml before and 63.1 +/- 16 pg/ml after heart autotransplantation). In contrast the significant ANF responses to changes in central venous pressure (CVP) induced by postural maneuvers (-45 degrees, + 16.2 +/- 4 pg/ml; +45 degrees, -18.5 +/- 4 pg/ml) were markedly altered after cardiac denervation (-45 degrees, +5.8 +/- 2 pg/ml; +45 degrees, -7.6 +/- 1 pg/ml). The changes in CVP and systemic blood pressure evoked by the postural challenges were comparable before and after cardiac denervation. These results demonstrate that cardiac nerves play a role in the control of ANF release.

Modulatory role of angiotensin-II in the secretion of atrial natriuretic factor in rabbits.

This study was designed to investigate whether the increase in circulating atrial natriuretic factor (ANF) levels produced by angiotensin II (Ang II) is a consequence of the hemodynamic changes or whether it occurs also in the absence of pressor changes. For this purpose in anesthetized and awake rabbits we evaluated the effects of Ang II (0.1 micrograms/kg.min) alone or during the simultaneous infusion of sodium nitroprusside (NP) at a dose titrated to abolish the pressor effects. Systemic blood pressure increased from 76 +/- 4 to 113 +/- 5 mm Hg (P less than 0.001) during Ang II and from 76 +/- 2 to 75 +/- 3 mm Hg (P = NS) during Ang II plus NP. The alpha-adrenergic agonist phenylephrine, used as a control, raised blood pressure from 65 +/- 2 to 101 +/- 8 mm Hg (P less than 0.001), and its pressor effect was abolished by the concomitant infusion of NP (64 +/- 2 to 61 +/- 1 mm Hg; P = NS). The increase in plasma ANF levels produced by Ang II alone (from 36.5 +/- 5 to 237 +/- 57 pg/ml; P less than 0.001) was not different from that observed during Ang II plus NP (from 46 +/- 10 to 207 +/- 88 pg/ml; P less than 0.001). In contrast, the stimulatory effect on ANF release of phenylephrine (from 56.1 +/- 9 to 202 +/- 40 pg/ml; P less than 0.001) was completely abolished when its pressor effects were prevented by the combined infusion of NP (from 58.5 +/- 15 to 42.3 +/- 10 pg/ml; P = NS). These results show that the stimulatory effect of Ang II on ANF release can be clearly dissociated from its pressor effect, whereas the increase in plasma ANF levels caused by phenylephrine is strictly related to its hemodynamic effect. Therefore, Ang II is capable of modulating ANF secretion in a manner that is independent of its pressor actions. In addition, our results suggest that ANF release is not solely linked to myocyte stretch.