Vassilios Didilis

Surgical treatment of pulmonary aspergillosis/mycosis in immunocompromised patients

Invasive pulmonary aspergillosis is a severe complication in immunosuppressed patients. Surgical resection can be curative in certain patients after antifungal treatment. Over a 7-year period, ten patients with suspected invasive pulmonary aspergillosis of two university hospitals were retrospectively reviewed. A literature review was undertaken. Patients age was 48.1 years (mean); the cause of immunosuppression was a hematological disease with consecutive therapy in seven patients and chronically corticoid therapy in three patients. After an antifungal therapy, surgical resection was performed with lobectomy/segmentectomy in 60% and with wedge-resection in 40%. Postoperative course were uneventful in seven patients, two patients died due to infectional circumstances, and one patient was reoperated because of empyema. The underlying disease marked long-term follow-up. Resection of focal pulmonary invasive aspergillosis can be curative. Clinical circumstances and dissemination must be taken into consideration to indicate surgery. To point out the best pathway randomised prospective studies are necessary.

DYNAMIC MECHANICAL PROPERTIES OF ARTERIAL AND VENOUS GRAFTS USED IN CORONARY BYPASS SURGERY

In this work we studied the frequency dependence of the dynamic mechanical characteristic s of saphenous vein (SV) and internal mammary artery (IMA) grafts. Rectangular longitudinal strips from 14 patients were tested under cyclic uniaxial tensile loading in the frequency range of 0.1–20 Hz, at 37°C in wet conditions. The dynamic mechanical parameters (the storage modulus ES and the hysteresis ratio h (loading/loop area)) together with the collagen phase modulus EH were computed as a function of frequency. The results showed that in all graft types ES and EH varied with frequency in the range 0.5–10 Hz, presenting a maximum in the neighboring of 1 Hz. The hysteresis ratio h was increased in the frequency range 1–20 Hz. It seems from the results that the physical resonance frequency of the components of the tissue responsible for their elastic behavior may lay in the range around 1 Hz, while that for the viscous behavior in the range of 20 Hz or more. Early clinical outcomes of both grafting were studied in parallel. In a one-year postoperative period the follow-up (clinical examination, electrocardiography, echocardiography and stress test) did not reveal any sign of graft occlusion or severe stenosis except one perioperative infraction but without any correlation to the graft quality.

Diltiazem versus Amiodarone to Prevent Atrial Fibrillation in Coronary Surgery

The prophylactic effect of amiodarone on atrial fibrillation after coronary bypass grafting with extracorporeal circulation was compared with that of diltiazem in two groups of 60 patients each. Patients were monitored continuously for 8 days. The incidence of atrial fibrillation was recorded retrospectively in a control group of 60 patients who received our standard prophylactic regimen of an oral beta blocker. The incidence of postoperative atrial fibrillation was not significantly different in the two test groups: 11.7% for the amiodarone group and 10% for the diltiazem group. The incidence of atrial fibrillation in the control group was 23.3% and the differences were marginally significant when compared to the amiodarone (p = 0.093) and diltiazem groups (p = 0.050). The prophylactic use of diltiazem or amiodarone is feasible and safe for patients undergoing coronary bypass, with similar rates of atrial fibrillation.

Accelerated intimal hyperplasia in aortocoronary internal mammary vein grafts in minipigs

BackgroundMore than 50% of aortocoronary saphenous vein grafts are occluded 10 years after surgery. Intimal hyperplasia is the initial critical step in the progression toward occlusion. Internal mammary veins, which are physiologically prone to less hydrostatic pressure, may undergo an accelerated progression to intimal hyperplasia and thus be suitable for investigation of the mechanisms of aortocoronary vein graft disease.MethodsSix minipigs underwent aortocoronary bypass grafting using standard cardiopulmonary bypass and cardioplegic arrest. Mammary vein were grafted in a reversed manner from ascending aorta to left anterior descending coronary artery (LAD). The proximal LAD was ligated, rendering the anterior left ventricle vein graft-dependent. Minipigs were killed after 4 weeks, and vein grafts were harvested. Histological and immunohistological investigation were performed with respect to morphometric analysis, endothelial damage/dysfunction (v-Willebrand-factor (vWF)), smooth muscle cells (α-smooth actin) and proliferation rate (proliferation marker Ki 67).ResultsMean intimal area of vein grafts was increased compared to ungrafted mammary veins. Intimal hyperplasia in vein grafts was characterized by massive accumulation of smooth muscle cells with a high proliferation rate and endothelial perturbation. Significant (p = 0.001) intimal hyperplasia of the grafted mammary vein compared to the ungrafted mammary vein was found. These changes were absent in ungrafted mammary veins.ConclusionThe present study demonstrates a pig model of aortocoronary vein graft intimal hyperplasia which is characterized by an accelerated progression within internal mammary veins. The model is suitable to investigate the pathophysiology of aortocoronary vein graft intimal hyperplasia as well as therapeutic approaches.

Internal thoracic artery side branch ligation for post coronary surgery ischemia.

Two cases of internal thoracic artery side-branch ligation in patients with recurrent angina after coronary bypass are reported with long-term follow-up. Ligation was performed with clips via a left thoracotomy. Treadmill stress testing after 3 and 4 years did not provoke any myocardial ischemia. These findings suggest that an unligated side-branch can produce a steal phenomenon.

Pulmonary invasion in multisystem Langerhans cell histiocytosis.

A 19-year-old woman was admitted with a simultaneous bilateral spontaneous pneumothorax. She had a history of multisystem Langerhans cell histiocytosis and first presented with diabetes insipidus 6 years ago. Langerhans cell histiocytosis mainly occurs in younger age groups. It can present as a single or multiple lesion and can affect one or several organ systems. In most patients the disease is limited to the lung and in some cases it can develop into progressive fibrotic lung disease and respiratory failure. Our patient was treated with corticosteroids and recently with chemotherapy which is thought to provoke pneumothorax. A computed tomographic scan, 1 month before admission, showed extensive pulmonary invasion, with diffuse bullus destruction of both lungs (Fig 1, upper lobes) and mainly in the lower lobes (Fig 2). The patient underwent a twostage bilateral bullaectomy and pleurodesis. At operation, the right lower lobe parenchyma showed a trabecular appearance (Fig 3). The histopathologic examination of the open biopsy specimen confirmed the diagnosis. Figure 4 shows a typical Langerhans nodule composed of Langerhans cells admixed with lymphocytes, plasma cells, eosinophil polymorphonuclear leukocytes, and macrophages. Langerhans cells (arrow) are characterized by their large kidney-shaped nuclei and the abundant amphiphilic cytoplasm. Immunohistochemical investigation confirmed the histiocytic origin of the cells (CD 31 and S-100 were markedly positive). The patient’s early postoperative course was uneventful. Address reprint requests to Prof. Bougioukas, Department of Cardiothoracic Surgery, General Hospital of Alexandroupolis, 19 Dimitras Str, 68100 Alexandroupolis, Greece; e-mail: gbougiou@med.dutb.gr. Fig 1. Fig 2.

The effect of amifostine on lung ischaemia–reperfusion injury in rats

OBJECTIVES Lung ischaemia-reperfusion injury (LIRI) frequently occurs after lung transplantation or cardiac surgery with cardiopulmonary bypass, thus increasing postoperative morbidity and mortality. As LIRI is associated with the release of reactive oxygen species and a subsequent inflammatory reaction, we tested whether amifostine, a thiol and free radical scavenger, has a beneficial effect on LIRI. METHODS A total number of 72 Wistar rats were subjected to LIRI with or without a single or double dose of amifostine (100 mg/kg, intraperitoneally). Experimental induction of LIRI was performed by clamping either the left lung hilum or the pulmonary artery alone for 60 min, followed by 90 min of reperfusion. Control groups consisted of LIRI and NaCl, a sham group and a no intervention group (baseline). At the end of the experiments, the left lung was analysed by quantitative RT-PCR of inflammatory marker gene expression, western blot of activated nuclear factor-κB (NF-κB) and light and electron microscopy. RESULTS In placebo and amifostine groups, the expression levels of pro-inflammatory markers were increased significantly and to a similar extent independent of the type of ischaemia induction. In contrast, amifostine reduced the activation of NF-κB in comparison with placebo. This effect was present independent of the type of ischaemia or the application of a single or double dose of amifostine. However, oedema formation, blood-gas barrier damage and inflammatory reaction were similar in all amifostine or placebo LIRI groups. CONCLUSIONS Despite a significant reduction in NF-κB activation, amifostine failed to decrease the inflammatory response and structural changes induced by LIRI in this experimental setting.

Hemodynamic effects of peri-operative statin therapy in on-pump cardiac surgery patients

BackgroundPeri-operative statin therapy in cardiac surgery cases is reported to reduce the rate of mortality, stroke, postoperative atrial fibrillation, and systemic inflammation. Systemic inflammation could affect the hemodynamic parameters and stability. We set out to study the effect of statin therapy on perioperative hemodynamic parameters and its clinical outcome.MethodsIn a single center study from 2006 to 2007, peri-operative hemodynamic parameters of 478 patients, who underwent cardiac surgery with cardiopulmonary bypass, were measured. Patients were divided into those who received perioperative statin therapy (n = 276; statin group) and those who did not receive statin therapy (n = 202; no-statin group). The two groups were compared together using Kolmogorov-Smirnov-Test, Fisher’s-Exact-Test, and Student’s-T-test. A p value < 0.05 was considered as significant.ResultsThere was no significant difference in the preoperative risk factors. Onset of postoperative atrial fibrillation was not affected by statin therapy. Extended hemodynamic measurements revealed no significant difference between the two groups, apart from Systemic Vascular Resistance Index (SVRI) . The no-statin group had a significantly higher SVRI (882 ± 206 vs. 1050 ± 501 dyn s/cm5/m2, p = 0.022). Inotropic support was the same in both groups and no significant difference in the mortality rate was noticed. Also, hemodynamic parameters were not affected by different types and doses of statins.ConclusionsPerioperative statin therapy for patients undergoing on-pump coronary bypass grafting or valvular surgery, does not affect the hemodynamic parameters and its clinical outcome.

Coronary artery bypass surgery in a patient with Kartagener syndrome: a case report and literature review

Kartagener syndrome consists of congenital bronchiectasis, sinusitis, and total situs inversus in half of the patients. A patient diagnosed with Kartagener syndrome was reffered to our department due to 3-vessel coronary disease. An off-pump coronary artery bypass operation was performed using both internal thoracic arteries and a saphenous vein graft. We performed a literature review for cases with Kartagener syndrome, coronary surgery and dextrocardia. Although a few cases of dextrocardia were found in the literature, no case of Kartagener syndrome was mentioned.

Factors affecting post minimally invasive direct coronary artery bypass grafting incidence of myocardial infarction, percutaneous transluminal coronary angioplasty, coronary artery bypass grafting and mortality of cardiac origin.

In the present study we identify parameters which influence the incidence of myocardial infarction (MI), need for percutaneous coronary intervention (PCI), coronary artery bypass grafting (CABG) and cardiac mortality after minimal invasive coronary artery bypass grafting (MIDCABG). With a mean follow-up of 30+/-11.2 months, 390 patients were assessed with Wald test-corrected chi(2) analysis to identify preoperative factors which correlate with a higher incidence of post-MIDCABG MI, PCI, CABG and mortality from cardiac causes. We found an increased incidence of postoperative MI in patients with 2-vessel (8.7%) and 3-vessel (7.7%) vs. 1.3% 1-vessel coronary artery disease (CAD) (P=0.023), and in patients with preceding cardiac procedure (CABG and PCI: 8.4% vs. 2.0% without, P=0.023). Also diabetes was associated with higher post-MIDCABG frequency of MI (P=0.035). Severity of angina was associated with lesser post-MIDCAB-PCI (P=0.011) while preceding CABG predicted a higher incidence (P=0.012). Preoperative low ejection fraction (EF) (multivariate, P<0.001), preoperative MI (P=0.007) and extent of CAD (P=0.001) were associated with a higher post-MIDCABG mortality. None of the parameters correlated with subsequent CABG MIDCABG. The extent and history of CAD, history of cardiac interventions and low EF seem to influence the outcome adversely and should be considered deciding pro or against the MIDCAB-option.