Minimal extracorporeal circulation reduces the incidence of postoperative major adverse events after elective coronary artery bypass grafting in high-risk patients. A single-institutional prospective randomized study.

Coronary artery bypass grafting (CABG) using minimal extracorporeal circulation (MECC) has been associated with an improved short-term clinical outcome compared to conventional extracorporeal circulation (CECC). The aim of this study was to evaluate the impact of MECC compared to CECC on postoperative major adverse events in high-risk patients undergoing elective coronary revascularization procedures. Two hundred patients undergoing elective CABG were randomized into two groups. In Group A (n=100), MECC was used while Group B (n=100) included patients who were operated on CECC. The incidence of postoperative major adverse events (myocardial infarction, renal failure, stroke, death) was the primary end-point of the study. MECC was associated with a 77% relative risk reduction in the incidence of major adverse events compared to CECC (p=0.004). The rate of major adverse events occurring in the high-risk patient subgroup (preoperative left ventricular ejection fraction ≤40%, age >65 years, EuroSCORE II >5) operated on with MECC was significantly lower in comparison to their CECC counterparts. Based on our results, cardiac centres should be encouraged to use MECC as the standard circuit when performing elective coronary procedures, even in a high-risk population.

The role of surgery in the management of malignant pleural mesothelioma.

Malignant pleural mesothelioma (MPM) is a relatively rare multifocal pleural tumor with low metastatic potential. Surgery can be used in MPM for diagnostic and therapeutic purposes. Thoracoscopy is a useful tool to obtain tissue biopsy to establish a definitive diagnosis and to perform talc poudrage of the pleural cavity in order to prevent reaccumulation of fluid. Cytoreductive procedures, such as pleurectomy/ decortication (PD) and extrapleural pneumonectomy (EPP) are also used in multimodal treatment protocols. The available evidence until now suggests that EPP offers better palliation of dyspnea and orthopnea due to a trapped lung and ventilation perfusion mismatch and better adjuvant radiation therapy planning when compared to PD. Better local disease control and obvious survival benefit by using EPP instead of PD are at the moment unproven. However, EPP is connected with high mortality and morbidity rates, especially if performed in centers without expertise with this complex procedure. EPP and thoracoscopic parietal pleurectomy are now tested in two ongoing prospective randomized trials for their efficacy in the treatment of this disease. In the absence of any controlled randomized trial, EPP should be considered as part of the treatment of MPM only within the context of a prospective randomized trial or in special centers with expertise in the procedure and always within a tri-modal or four-modal treatment protocol, including also chemotherapy, radiotherapy, intrapleural immunochemotherapy and laser photodynamic therapy.

Fibrous tumor of the lung: diagnostic and therapeutic considerations apropos of two cases.

Solitary fibrous tumor (SFT) of the pleura and the lung is an uncommon spindle cell neoplasm arising from the visceral pleura in the majority of the cases. Current diagnostic and therapeutic considerations are discussed apropos of 2 recent cases. 1st case: A 46-year-old male, heavy smoker, presented with nonspecific complaints and a mass in the left posterior mediastinum at the level of the 5th thoracic vertebra. Computed tomography (CT) and magnetic resonance imaging (MRI) of the chest confirmed the position of the mass in proximity to the thoracic wall at that level. Through a left posterolateral thoracotomy, a 4 x 5 x 2 cm mass, mushroom-shaped, stalky, completely covered by the lung parenchyma, was resected. Histopathological examination revealed a SFT of the lung. 2nd case: A 54-year-old woman presented with symptoms of respiratory distress and persistent hypoglycaemia. CT scan of the chest showed a huge mass within the right hemithorax, compressing the mediastinum and the contralateral lung. The mass was initially detected on chest radiography and CT scan 3 years before resection. Fine needle biopsy (FNB) results were inconclusive and resection of the mass through a right thoracotomy established the diagnosis of malignant SFT. Resection of the mass resulted in recovery of respiratory function and the paraneoplastic hypoglycaemia. Radiologic features and inconclusive fine needle aspiration (FNA)/FNB results make preoperative diagnosis of SFTs of the pleura and lung difficult. Diagnosis of SFT will be established with certainty after surgery. Resection with clear margins is the main important prognostic factor.

Cardiomyogenic potential of human adult bone marrow mesenchymal stem cells in vitro.

BACKGROUND: The aim of this study was to investigate the ability of adult human bone marrow mesenchymal stem cells to differentiate towards a cardiomyogenic phenotype IN VITRO. METHODS: Bone marrow samples were aspirated from 30 patients undergoing open heart surgery from the anterior iliac crest. Second passaged cells were treated with 10 microM 5-azacytidine. As control groups we used cells not expanded in culture and cells untreated with 5-azacytidine. Morphologic characteristics were analysed by confocal and electron microscopy. The expression of the cytoskeletal protein vimentin and muscle-specific myocin heavy chain was analysed by immunohistochemistry. The expression of the cardiomyocyte specific genes alpha-cardiac actin, beta-myocin heavy chain and cardiac troponin-T was detected by reverse transcriptase polymerase chain reaction. RESULTS: Mesenchymal stem cells were spindle-shaped with irregular processes. Cells treated with 5-azacytidine assumed a stick-like morphology. They connected with adjoining cells to form myotube-like structures. Numerous myofilaments were detected in induced cells which were immunohistochemically positive for myosin heavy chain and vimentin. The mRNAs of all specific cardiac genes were expressed in both induced and uninduced cells. CONCLUSION: These results indicate that adult human bone marrow mesenchymal stem cells treated with 5-aza can differentiate towards a cardiomyogenic lineage IN VITRO.

The effect of milrinone on metabolism after cardiopulmonary bypass.

AIM: The aim of this study was to examine the effects of milrinone on tissue metabolism perioperatively in cardiac surgery patients using extracorporeal circulation, in comparison to adrenaline and placebo. These effects were measured indirectly by measuring serum lactate, base excess and glucose levels at standard intervals. METHODS: Seventy-seven consecutive patients, who underwent elective cardiac surgery, were allocated in 3 groups. Inotropic support was initiated coming off CPB (cardiopulmonary bypass) if there was evidence of hypotension (mean arterial pressure [MAP] <60 mmHg), after adequate preload (pulmonary capillary wedge pressure [PCWP] >10 mmHg). Milrinone was used in patients with pulmonary hypertension (MPAP >20 mmHg). Group 1 (N.=26) received no inotropes, placebo. Group 2 (N.=32) received adrenaline. Group 3 (N.=19) received adrenaline + milrinone at 0.5 microg/kg/min infusion. Adrenaline was infused at a variable dose (0.01-0.02 microg/kg/min) to achieve a MAP >60 mmHg. The serum lactate, base excess and glucose levels were measured at standard intervals in all 3 groups. Diabetic, hepatic or renal failure patients (serum creatinine >2 mg/dL), were excluded from the study. Patient demographic and clinical characteristics were similar in all 3 groups. RESULTS: Repeated measure analysis of variance between groups showed significantly lower serum lactate levels and higher base excess in the milrinone group (P<0.05), after 2 to 4 hours of treatment. Serum glucose levels were higher in the adrenaline group (P=0.01). There were no immediate complications, morbidity or mortality in the study groups. CONCLUSION: These findings suggest that milrinone has a beneficiary effect on aerobic tissue metabolism after extracorporeal circulation, reflected on serum lactate, base excess and glucose levels, possibly due to a combination of positive inotropic and peripheral vasodilatory effect of the drug.

Secondary endovascular repair of a reconstructed superior vena cava in a patient with a malignant thymic epithelial neoplasm.

Thymic epithelial tumors can cause venous obstruction from compression or direct invasion of the superior vena cava (SVC) or the innominate veins. We report a case of a 40-year-old patient with a Masaoka stage III thymoma that resulted in obstruction of the left innominate vein and extrinsic compression of the SVC. All macroscopic tumors were resected together with ligation of the left innominate vein and reconstruction of the SVC with an ePTFE graft. Early graft thrombosis occurred in the first postoperative month with clinical signs of SVC syndrome. Endovascular repair was performed with the deployment of self-expanding nitinol stents, resulting in immediate relief of symptoms. The stented graft has remained patent for a follow-up period of 7 months.

Thoracic splenosis twenty-nine years after traumatic splenectomy mimicking intrathoracic neoplasm.

Thoracic splenosis refers to a condition of ectopic splenic tissue in the thoracic cavity. It is usually a consequence of splenic tissue seeding in the pleural cavity after thoracoabdominal trauma. A rare case of thoracic splenosis, in a 62-year-old man who had had a traumatic splenectomy due to thoracoabdominal trauma 29 years earlier, is reported. The patient, a heavy smoker, was admitted for evaluation of a left-side thoracic lesion discovered on a plain chest film. Bronchoscopy, CT scan and needle biopsy proved inconclusive for the diagnosis. Exploratory thoracotomy was necessary to establish the diagnosis. During the operation, a thoracic splenosis was confirmed. To date, only 28 cases of thoracic splenosis have been reported in the literature. The purpose of this report is to present a new case of splenosis of the thoracic cavity simulating intrathoracic neoplasm.

The supportive value of pre-bypass L-glutamate loading in patients undergoing coronary artery bypass grafting.

AIM: Experimental studies have demonstrated that an exogenous supply of glutamate improves mechanical function and recovery of ischemic myocardium. The aim of the present study was to investigate the effect of myocardial pre-bypass loading with glutamate on myocardial protection during global ischemia and reperfusion of patients undergoing coronary artery bypass grafting (CABG). METHODS: The study was double blinded. Twenty patients undergoing elective CABG were randomized to receive L-glutamate (n = 10) or normal saline (n = 10). Intracellular levels of glutamate, ATP and lactate were measured in left ventricular biopsies collected 10 min after aortic clamp release. Hemodynamic data, and postoperative release of CK-MB and troponin T were also measured. RESULTS: Pre-bypass administration of glutamate resulted in myocardial glutamate loading since glutamate levels were significantly higher in the glutamate group of patients than in controls (18.6 +/- 3.1 versus 8.7 +/- 1.2 microg/g tissue, P < 0.001). In the same group ATP levels were also significantly higher (2.4 +/- 0.7 versus 1.5 +/- 0.4 microg/g tissue, P < 0.05) and lactate levels significantly less than in controls (6.9 +/- 1.9 versus 12.0 +/- 2.1 microg/g tissue, P < 0.001). Glutamate patients had statistically significantly superior post-bypass hemodynamic performance (cardiac index, left ventricular stroke work index, systemic vascular resistance and pulmonary vascular resistance). Statistically significantly lower levels of CK-MB (6 h postoperative), total and peak CK-MB, troponin T (24 h postoperative), and total troponin T were found in the glutamate group. CONCLUSIONS: The results of this preliminary study indicate that pre-bypass intravenous administration of glutamate in patients undergoing CABG has a supportive effect on myocardial metabolism during global ischemia and reperfusion, improves patients' postoperative hemodynamic performance and reduces postoperative cardiac enzyme release.

Non hypoxia-related splenic infarct in a patient with sickle cell trait and infectious mononucleosis.

Splenic infarction in patients with sickle cell trait is usually related to hypoxic conditions, while non-hypoxia-related infarcts are extremely rare. We report on a case of a 17-year-old male patient, living at sea level, who developed a severe left upper quadrant abdominal pain during the course of a febrile episode. On physical examination he had a mildly palpable but extremely painful spleen. A spleen scan revealed 2 areas of impaired radionucleide distribution. Hepatic enzymes were moderately increased and the IgM anti-EBV antibodies positive. Hemoglobin electrophoresis revealed the presence of 42% of hemoglobin S. A probable diagnosis of splenic infarction was established in a patient with sickle cell trait, during the course of infectious mononucleosis. The patient was treated symptomatically. The conditions of splenic congestion induced by the EBV infection and the high-grade fever may have contributed to splenic sequestration and subsequent infarcts.

Differential effect of preconditioning on post-ischaemic myocardial performance in the absence of substantial infarction and in extensively infarcted rat hearts.

OBJECTIVES: There is controversy concerning the beneficial effects of ischaemic preconditioning during short periods of ischaemia (stunning). The aim of the study was to investigate post-ischaemic myocardial performance after various periods of ischaemia in both non-preconditioned and preconditioned hearts and to compare these results with infarct volume estimation. METHODS: Isolated perfused rat hearts were subjected to various periods of sustained ischaemia (15, 20, 30, and 45 min). Haemodynamic parameters, infarct size and lactate dehydrogenase (LDH) leakage were recorded in both preconditioned and non-preconditioned hearts. RESULTS: After 15 min of ischaemia, preconditioned hearts revealed significantly lower developed pressure than non-preconditioned hearts (80+/-4.1 vs. 95+/-0.3%, P=0.02). In the 20 min ischaemia group, preconditioning resulted in non-significantly lower developed pressure (76+/-3.1% in preconditioned hearts vs. 87+/-5.3% in non-preconditioned hearts, P=0.11). In these groups infarct volume was small and not different between non-preconditioned and preconditioned hearts. After 30 min of ischaemia, preconditioning significantly improved developed pressure (66+/-3.1% in preconditioned and 44+/-5% in non-preconditioned hearts, P=0.002). LDH leakage was significantly higher in non-preconditioned hearts compared with preconditioned hearts (16+/-2.3 vs. 9.0+/-1.3, P=0.04), whereas infarct volume was not (12.5+/-0.8 and 9.8+/-1.5, respectively, P=0.1). Non-preconditioned hearts of this group, subjected to inotropic stimulation at the end of reperfusion, responded poorly. Significantly higher developed pressure was attained by preconditioned hearts (150+/-3.1 vs. 123+/-7.5%, P=0.01). After 45 min of ischaemia, preconditioning resulted in 69% limitation of infarct volume (P<0.0001) and 53% reduction in LDH release (P=0.009). Developed pressure was 57+/-8.5% in preconditioned hearts and 32+/-4.5% in non-preconditioned hearts (P=0.02). CONCLUSIONS: When ischaemic insult results in minimally lethal injuries, preconditioned hearts do not have the advantage of not being prone to stunning rather than non-preconditioned. If ischaemic insult is potentially able to produce extensive infarction, improvement in post-ischaemic myocardial function is mainly due to infarct size limitation evoked by preconditioning.

Long-term surgical outcome of closed mitral commissurotomy.

Seven hundred and fifty-four patients who underwent closed mitral commissurotomy (CMC) between 1958 and 1993 (71% female, 29% male; mean age 39 years) for acquired mitral stenosis were reviewed postoperatively. Particular attention was given to those patients who later required mitral valve replacement (MVR). The total follow up experience was 9,607.9 years. Eighty-two patients (11%) needed a repeat CMC and 30% of these patients had subsequent MVR. In all, 146 patients (19, 3%) required MVR a mean of 17.0 years after commissurotomy (range one to 35 years). Preoperative factors associated with an unsatisfactory postoperative course and with later MVR included preoperative functional class, calcification of the mitral valve and subvalvular fusion. The adequacy of valvulotomy assessed at operation was also related to outcome. Postoperatively, poor functional improvement, congestive heart failure and the necessity for a repeat CMC were associated with late MVR. The indications for MVR were restenosis (59%), residual stenosis with or without mild mitral regurgitation (30%), and moderate to severe regurgitation (11%). Among survivors, 88% improved at least one functional class after MVR and the majority was free of congestive heart failure. It is concluded that CMC provides excellent long term clinical improvement in appropriately selected patients. The mean time interval of 17 years between CMC and late MVR reveals the efficacy of CMC to achieve satisfactory long term results.