Christos Papakonstantinou

Neurocognitive outcome after coronary artery bypass surgery using minimal versus conventional extracorporeal circulation: a randomised controlled pilot study

Objective Neurocognitive impairment can be a debilitating complication after cardiac surgery. The aim of this study was to assess the effect of minimal extracorporeal circulation (MECC) versus conventional extracorporeal circulation (CECC) on neurocognitive function after elective coronary artery bypass grafting (CABG) and whether this can be attributed to improved cerebral perfusion intraoperatively. Methods and results 64 patients scheduled for elective CABG surgery were prospectively randomly assigned to surgical revascularisation with MECC versus CECC. All patients were continuously monitored for changes in cerebral oxygenation with near-infrared spectroscopy during the procedure. Neurocognitive assessment was performed before surgery, on the day of discharge and at 3 months postoperatively using a battery of standardised neurocognitive tests. Both groups were comparable in terms of demographic and clinical data. MECC was associated with improved cerebral perfusion during cardiopulmonary bypass (CPB). Eleven patients operated on with MECC and 17 with CECC experienced at least one episode of cerebral desaturation (38% vs 55%, p=0.04) with similar duration (10 vs 12.3 min, p=0.1). At discharge patients operated on with MECC showed a significantly improved performance on complex scanning, visual tracking, focused attention and long-term memory. At 3 months significantly improved performance was also evident on visuospatial perception, executive function, verbal working memory and short-term memory. Patients operated on with MECC experienced a significantly lower risk of early cognitive decline both at discharge (41% vs 65%, p=0.03) and at 3-month evaluation (21% vs 61%, p<0.01). Conclusions Use of MECC attenuates early postoperative neurocognitive impairment after coronary surgery compared with conventional CPB. This finding may have important implications on the surgical management strategy for coronary artery disease. Clinical trial registration number The study is registered at ClinicalTrials.gov, number NCT01213511.

Primary Intrathoracic Goiter: A Rare and Potentially Serious Entity

BACKGROUND Here we review primary intrathoracic goiter (P-ITG), a rare but potentially serious congenital entity that is distinct from the much more common secondary intrathoracic goiter. The latter is an extension of cervical thyroid that descends within the mediastinum. In contrast, P-ITGs lack a connection with the cervical thyroid and their blood supply comes from intrathoracic vessels. SUMMARY P-ITGs can coexist with a normal or goitrous thyroid gland. When they coexist, either or both may be independently affected by neoplastic, infectious, or infiltrative processes. P-ITGs are mainly located in the anterosuperior mediastinum. Location in posterior or middle mediastinum is observed in 15% of cases, making the diagnosis challenging. Although P-ITGs are rare, they are important because they may reach large dimensions with serious consequences. Compression of the trachea is the most common clinical finding, but compression of other mediastinal organs is also observed. Computerized axial tomography (CT) and radionuclide imaging can suggest or make the diagnosis in most cases. The differential diagnosis includes other mediastinal tumors that show high attenuation on unenhanced CT. The treatment of choice is surgical resection of the goiter through a thoracic approach. Thoracic surgery for resection of a small primary mediastinal goiter is considered to be a relatively safe procedure. Long-standing P-ITGs may cause pressure on the trachea, however, resulting in tracheomalacia. This development is serious in its own right and complicates thoracic surgery. CONCLUSIONS Resection through a thoracic approach is the appropriate treatment for a P-ITG. Surgical intervention is usually indicated without delay upon the establishment of the diagnosis because these goiters exhibit progressive growth. When P-ITGs are small, this approach should prevent the development of tracheomalacia and other serious complications.

Serum levels of matrix metalloproteinases -1,-2,-3 and -9 in thoracic aortic diseases and acute myocardial ischemia

BackgroundMatrix metalloproteinases (MMPs) constitute a family of zinc-dependent proteases (endopeptidases) whose catalytic action is the degradation of the extracellular matrix components. In addition, they play the major role in the degradation of collagen and in the process of tissue remodeling. The present clinical study investigated blood serum levels of metalloproteinases- 1, -2, -3 and -9 in patients with acute and chronic aortic dissection, thoracic aortic aneurysm and acute myocardial ischemia compared to healthy individuals.MethodsThe blood serum levels of MMP-1, -2, -3 and -9 were calculated in 31 patients with acute aortic dissection, 18 patients with chronic aortic dissection, 18 patients with aortic aneurysm and in 13 patients with acute myocardial ischemia, as well as in 15 healthy individuals who served as the control group. Serum MMP levels were measured by using an ELISA technique.ResultsThere were significantly higher levels of MMP-3 in patients with acute myocardial ischemia as compared to acute aortic dissection (17.33 ± 2.03 ng/ml versus 12.92 ± 1.01 ng/ml, p < 0.05). Significantly lower levels of MMP-1 were found in healthy controls compared to all groups of patients (1.1 ± 0.38 ng/ml versus 2.97 ± 0.68 in acute aortic dissection, 3.09 ± 0.98 in chronic dissection, 3.16 ± 0.51 in thoracic aortic aneurysm and 4.58 ± 1.04 in acute myocardial ischemia, p < 0.05). Higher levels of MMP-1 and MMP-3 were detected on males. There was a positive correlation with increasing age (r = 0.38, p < 0.05). In patients operated for acute type A aortic dissection, the levels of MMP-1, MMP-3 and MMP-9 increased immediately after surgery, while the levels of MMP-2 decrease. At 24 hours postoperatively, levels of MMP -1, -2 and -9 are almost equal to the preoperative ones.ConclusionMeasurement of serum MMP levels in thoracic aortic disease and acute myocardial ischemia is a simple and relatively rapid laboratory test that could be used as a biochemical indicator of aortic disease or acute myocardial ischemia, when evaluated in combination with imaging techniques.

Hybrid approach of ventricular assist device and autologous bone marrow stem cells implantation in end-stage ischemic heart failure enhances myocardial reperfusion

We challenge the hypothesis of enhanced myocardial reperfusion after implanting a left ventricular assist device together with bone marrow mononuclear stem cells in patients with end-stage ischemic cardiomyopathy. Irreversible myocardial loss observed in ischemic cardiomyopathy leads to progressive cardiac remodelling and dysfunction through a complex neurohormonal cascade. New generation assist devices promote myocardial recovery only in patients with dilated or peripartum cardiomyopathy. In the setting of diffuse myocardial ischemia not amenable to revascularization, native myocardial recovery has not been observed after implantation of an assist device as destination therapy. The hybrid approach of implanting autologous bone marrow stem cells during assist device implantation may eventually improve native cardiac function, which may be associated with a better prognosis eventually ameliorating the need for subsequent heart transplantation. The aforementioned hypothesis has to be tested with well-designed prospective multicentre studies.

Haematological effects of minimized compared to conventional extracorporeal circulation after coronary revascularization procedures.

During the last decade, minimized extracorporeal circulation (MECC) systems have shown beneficial effects to the patients over the conventional cardiopulmonary bypass (CECC) circuits. This is a prospective randomized study of 99 patients who underwent coronary artery bypass grafting (CABG) surgery, evaluating the postoperative haematological effects of these systems. Less haemodilution (p=0.001) and markedly less haemolysis (p<0.001), as well as better preservation of the coagulation system integrity (p=0.01), favouring the MECC group, was found. As a clinical result, less bank blood requirements were noted and a quicker recovery, as far as mechanical ventilation support and ICU stay are concerned, was evident with the use of MECC systems. As a conclusion, minimized extracorporeal circulation systems may attenuate the adverse effects of conventional circuits on the haematological profile of patients undergoing CABG surgery.

Left Ventricular Decompression During Peripheral Extracorporeal Membrane Oxygenation Support With the Use of the Novel iVAC Pulsatile Paracorporeal Assist Device

Extracorporeal membrane oxygenation (ECMO) has become a widely accepted short-term mechanical circulatory support device in patients with refractory cardiogenic shock. A major drawback of the peripheral venoarterial extracorporeal membrane oxygenation is that in patients with profoundly reduced left ventricular contractility associated with high left-heart filling pressure, there is always concern for venting the failing ventricle. We describe a minimally invasive technique for decompressing the left ventricle in this setting using a novel pulsatile paracorporeal assist device, the iVAC 3L (PulseCath, Groningen, The Netherlands). It is implanted through the right axillary artery and provides hemodynamic support while directly off-loading the left ventricle.

The management of post-intubation tracheal stenoses with self-expandable stents: early and long-term results in 11 cases.

OBJECTIVE The optimal management of post-intubation tracheal stenoses is surgical reconstruction of the airway. Stenting of the trachea using silastic T-tubes or one of the various types of tracheal stents are the alternative ways to surgical reconstruction for the management of post-intubation tracheal stenoses. The early and long-term results of 11 patients with post-intubation tracheal stenosis, who underwent tracheal stenting with self-expandable metallic stents (SEMSs), are presented. METHODS Twelve patients (10 men, mean age: 47.8±20.4 years) with post-intubation tracheal stenosis were referred for tracheal stenting with SEMS (2000-2004). In three cases, the upper tracheal stenosis extended within the subglottic larynx. Stenting was successful in 11 patients, while, in one patient with involvement of the subglottic larynx, the attempt to insert the stent failed. Follow-up time varied from 6 to 96 months, and it was made with virtual and fiberoptic bronchoscopy. RESULTS Immediate relief of obstructive symptoms was observed in all the 11 patients, where an SEMS was successfully inserted. Stent dislodgement occurred shortly after the procedure in two patients, and it was treated with insertion of a new stent in the first case and a stent-on-stent insertion in the second. Good patency of the stent was observed in three patients for 60-96 months. Three patients with good patency of the stent died from other reasons 24-48 months after stent insertion. Four patients developed obstructive granulation tissue at the ends of the stent after 12-43 months, requiring further treatment with thermal lasers and/or tracheostomy. One patient underwent stent removal and successful laryngotracheal reconstruction 6 months after stent insertion. CONCLUSIONS The application of SEMS in post-intubation tracheal stenoses results in immediate improvement of obstructive symptoms without significant perioperative complications. SEMSs have the potential risks of migration and of granulation tissue formation at the end of the stent. SEMS should be applied only in strictly selected patients with post-intubation tracheal stenosis, who are considered unfit for surgery and/or with limited life expectancy.

Intraoperative Infusion of S(+)-Ketamine Enhances Post-thoracotomy Pain Control Compared With Perioperative Parecoxib When Used in Conjunction With Thoracic Paravertebral Ropivacaine Infusion

OBJECTIVE The authors explored the use of continuous postoperative subpleural paravertebral ropivacaine alone combined with intraoperative S(+)-ketamine or perioperative parecoxib as a new approach to pain control after major thoracotomy. DESIGN A randomized study. SETTINGS A single university hospital. PARTICIPANTS Eighty patients underwent elective thoracotomy under general anesthesia. METHODS Study patients were assigned to 1 of 3 groups: group K (n = 27) received intraoperative S(+)-ketamine (0.5 mg/kg as a preincisional bolus followed by a continuous infusion 400 μg/kg/h), group P (n = 27) received perioperative parexocib (40 mg before extubation and 12 hours postoperatively), and group C (n = 26) served as the control group. At the end of surgery, all patients received a subpleural paravertebal infusion of ropivacaine. MEASUREMENTS AND MAIN RESULTS Pain was assessed by visual analog scores and supplemental morphine consumption with PCA up to 48 hours postoperatively. The duration of stay and postoperative functional parameters also were collected. Compared with ropivacaine alone, S(+)-ketamine significantly reduced pain scores at rest and during movement at 4, 12, 24, and 48 hours postoperatively. Moreover, at 24 and 48 hours, pain was less after S(+)-ketamine compared with parexocib. S(+)-ketamine also reduced morphine needs in comparison to placebo at 4, 12, 24, and 48 hours and in comparison to parexocib at 48 hours after thoracotomy. There were no differences in parameters for lung or bowel function, mobilization time, or ICU and hospital stay. CONCLUSIONS In patients with thoracotomy, postoperative paravertebral ropivacaine combined with intraoperative S(+)-ketamine provided better early postoperative pain relief than ropivacaine and perioperative parexocib or ropivacaine alone.

Use of minimal extracorporeal circulation circuit for left ventricular assist device implantation.

We describe successful use of a minimal extracorporeal circulation circuit (MECC) as an alternative to conventional cardiopulmonary bypass (CPB) for the implantation of left ventricular assist device (LVAD) in a 65-year-old patient with ischemic dilated cardiomyopathy. A Jarvik 2000 was implanted through a median sternotomy with the outflow graft anastomosed to the ascending aorta. MECC circuit provides optimal circulatory support throughout the procedure and prevents hemodynamic instability caused by marked displacement of the heart for exposure of the left ventricular apex, while minimizing the adverse effects of conventional CPB.

Use of Minimized Extracorporeal Circulation System in Noncoronary and Valve Cardiac Surgical Procedures—A Case Series

The aim of this report is to explore application of minimized cardiopulmonary bypass (CPB) circuits in areas of cardiac surgery other than coronary bypass grafting and aortic valve surgery. We report three cases operated under minimal extracorporeal circulation support. Replacement of the descending thoracic aorta was performed in two patients; one with a descending aortic aneurysm and one with pseudoaneurysm formation after previous coarctation repair. We have also implanted a left ventricular assist device for destination therapy. The minimized extracorporeal circulation system provides optimal circulatory support, while it is associated with reduced postoperative morbidity, minimizing the side effects from the use of CPB. Moreover, when off-pump technique is attempted, it can be used as a standby circuit connected to the patient so as to enhance safety of the procedure. Minimized extracorporeal circulation systems can be used with safety and efficacy in a wide range of cardiac surgeries including descending aorta pathology and assist device implantation.