Dimitrios Dougenis

Surgery of the Thoracic Aorta

The modern surgical treatment of disorders of the thoracic aorta began in the early 1950s when Gross, Swan, Lam, and DeBakey and their associates1–4 reported successful treatment of coarctation and aneurysms of the descending thoracic aorta using segmental resection and replacement with several types of grafts. In 1956, Cooley and DeBakey5 reported the first successful operation for resection and graft replacement of the ascending aorta using cardiopulmonary bypass. In 1957, DeBakey and colleagues,6 also using cardiopulmonary bypass, reported the first successful resection and graft replacement of an aneurysm of the aortic arch. Since then, important advances in the diagnosis .xa0.xa0.

Reoperations on the Aortic Root and Ascending Aorta

BACKGROUNDnReoperations on the aortic root and the ascending aorta are being performed with increasing frequency and remain a challenging problem.nnnMETHODSnEighty-one patients (age range, 14 to 78 years) underwent reoperations on the aortic root or the ascending aorta during a 14.5-year interval ending October 1996. The previous operations were aortic valve procedure (28%), coronary artery bypass grafting (25%), aortic root replacement (24%), ascending aortic replacement (19%), and miscellaneous (5%). Twenty-two patients (27%) had had two or more previous operations. The principal indications for reoperation were true or false aneurysm (35%), acute or chronic dissection (28%), and malfunction of an aortic valve substitute (27%). The reoperations performed were aortic root replacement (composite graft, allograft, or autograft) in 48 patients and graft replacement of the ascending aorta in 33 patients. Concomitant procedures included aortic arch replacement in 43 patients (55%) and coronary artery bypass grafting in 33 patients (41%).nnnRESULTSnThe 30-day mortality rate was 8.6% (7 patients). It was 8.3% for aortic root replacement and 9.1% for ascending aorta replacement (p > 0.05). Using stepwise multivariate logistic regression analysis of 23 variables, preoperative functional class III/IV (p = 0.047) and duration of cardiopulmonary bypass (p = 0.007) were significant independent predictors of early death. The mean duration of follow-up was 3.6 years. The 1-year, 5-year, and 10-year survival rates were 89%, 81%, and 69%, respectively. Freedom from reoperation on the heart or ascending aorta was 98%, 92%, and 69%, respectively. Reoperation for false aneurysm (p = 0.050) and the presence of coexisting coronary artery disease requiring bypass grafting (p = 0.010) were the only significant predictors of late mortality.nnnCONCLUSIONSnReoperations on the aortic root and the ascending aorta can be accomplished with acceptable early mortality and satisfactory long-term results. More frequent resection of the aneurysmal or dissected segments of the ascending aorta and aortic root at the initial operation may reduce the need for subsequent reoperation.

Pharmacologic prophylaxis for atrial fibrillation following cardiac surgery: a systematic review

Atrial Fibrillation (AF) is the most common arrhythmia occurring after cardiac surgery. Its incidence varies depending on type of surgery. Postoperative AF may cause hemodynamic deterioration, predispose to stroke and increase mortality. Effective treatment for prophylaxis of postoperative AF is vital as reduces hospitalization and overall morbidity. Beta - blockers, have been proved to prevent effectively atrial fibrillation following cardiac surgery and should be routinely used if there are no contraindications. Sotalol may be more effective than standard b-blockers for the prevention of AF without causing an excess of side effects. Amiodarone is useful when beta-blocker therapy is not possible or as additional prophylaxis in high risk patients. Other agents such as magnesium, calcium channels blocker or non-antiarrhythmic drugs as glycose-insulin - potassium, non-steroidal anti-inflammatory drugs, corticosteroids, N-acetylcysteine and statins have been studied as alternative treatment for postoperative AF prophylaxis.

Neuronal Cell Death in the Ischemic Spinal Cord: The Effect of Methylprednisolone

BACKGROUNDnCell death occurs by either necrosis or apoptosis. The role of apoptosis in the neuronal degeneration after ischemia remains to be defined. We studied (1) the nature of neuronal death and (2) the neuroprotective action of methylprednisolone in a rat model of spinal cord ischemia.nnnMETHODSnSpinal cord ischemia was induced in adult Long-Evans rats by occluding the aortic arch for 14 minutes and simultaneously equilibrating the femoral artery pressure to the atmospheric pressure. Twenty rats were subjected to ischemia without treatment and another twenty to ischemia after treatment with methylprednisolone (30 mg/kg, 4 hours before ischemia). The animals were sacrificed and the lumbar spinal cords were examined on postoperative days 1 and 2.nnnRESULTSnOn day 1, neurons with morphology indicative of apoptosis were present in the gray matter. Their numbers increased from the ventral to the dorsal location. There were significantly fewer apoptotic neurons in the dorsal horn of the methylprednisolone-treated animals. DNA obtained from the spinal cord of untreated rats on days 1 and 2 showed laddering after electrophoresis, a feature of apoptosis. Pretreatment with methylprednisolone inhibited the development of DNA laddering. Methylprednisolone treatment was not associated with significantly improved neurologic function in the postoperative period.nnnCONCLUSIONSnApoptotic neuronal death occurs in the rat spinal cord after transient ischemia and is attenuated by pretreatment with methylprednisolone.

Pancoast tumors: characteristics and preoperative assessment

Superior sulcus tumors (SSTs), or as otherwise known Pancoast tumors, make up a clinically unique and challenging subset of non-small cell carcinoma of the lung (NSCLC). Although the outcome of patients with this disease has traditionally been poor, recent developments have contributed to a significant improvement in prognosis of SST patients. The combination of severe and unrelenting shoulder and arm pain along the distribution of the eighth cervical and first and second thoracic nerve trunks, Horners syndrome (ptosis, miosis, and anhidrosis) and atrophy of the intrinsic hand muscles comprises a clinical entity named as Pancoast-Tobias syndrome. Apart NSCLC, other lesions may, although less frequently, result in Pancoast syndrome. In the current review we will present the main characteristics of the disease and focus on the preoperative assessment.

Safety of Magnetic Resonance Imaging in Patients With Implanted Cardiac Prostheses and Metallic Cardiovascular Electronic Devices

Magnetic resonance imaging (MRI) in patients with implanted cardiac prostheses and metallic cardiovascular electronic devices is sometimes a risky procedure. Thus MRI in these patients should be performed when it is the only examination able to help with the diagnosis. Moreover the diagnostic benefit must outweigh the risks. Coronary artery stents, prosthetic cardiac valves, metal sternal sutures, mediastinal vascular clips, and epicardial pacing wires are not contraindications for MRI, in contrast to pacemakers and implantable cardioverter-defibrillators. Appropriate patient selection and precautions ensure MRI safety. However it is commonly accepted that although hundreds of patients with pacemakers or implantable cardioverter-defibrillators have undergone safe MRI scanning, it is not a safe procedure. Currently, heating of the pacemaker lead is the major problem undermining MRI safety. According to the US Food and Drug Administration (FDA), there are currently neither MRI-safe nor MRI-compatible pacemakers and implantable cardioverter-defibrillators. In this article we review the international literature in regard to safety during MRI of patients with implanted cardiac prostheses and metallic cardiovascular electronic devices.

Modified maximal thymectomy for myasthenia gravis: effect of maximal resection on late neurologic outcome and predictors of disease remission.

BACKGROUNDnAlthough thymectomy is a standard practice of care in patients with myasthenia gravis, the best approach to thymic resection remains controversial. This study was conducted to assess the effect of maximal resection on neurologic outcome and identify predictors of disease remission.nnnMETHODSnData of 78 myasthenic patients who underwent modified maximal thymectomy during a 17-year period were retrospectively analyzed. The primary study end point was the achievement of complete remission. Separate analysis was performed for thymoma and nonthymoma patients regarding the factors predicting the neurologic outcome.nnnRESULTSnNo patients died perioperatively. Surgical morbidity was 7.7%. The rate of postoperative myasthenic crisis was 3.8%. Thymoma and nonthymoma patients experienced comparable complete stable remission prediction (74.5% vs 85.7% at 15 years; p = 0.632). The absence of steroids in the preoperative medical treatment was statistically related to the prediction for complete stable remission in both thymoma (95% confidence interval [CI], 2.687 to 339.182, p = 0.006) and nonthymoma patients (95% CI, 1.607 to 19.183; p = 0.007) in multivariate analysis. In thymomatous myasthenia gravis, there was a statistically significant association between disease remission and the World Health Organization (WHO) histologic classification (95% CI, 0.262 to 0.827; p = 0.009).nnnCONCLUSIONSnMaximal resections are recommended in myasthenic patients. Disease severity represents the prime determinant of the neurologic outcome after thymectomy. The neurologic outcome in patients after thymectomy may be statistically associated with the WHO classification subtypes but not necessarily with the aggressiveness of these tumors.

The need for intra aortic balloon pump support following open heart surgery: risk analysis and outcome.

BackgroundThe early and intermediate outcome of patients requiring intraaortic balloon pump (IABP) was studied in a cohort of 2697 adult cardiac surgical patients.Methods136 patients requiring IABP (5.04%) support analysed over a 4 year period. Prospective data collection, obtained.ResultsThe overall operative mortality was 35.3%. The operation specific mortality was higher on the Valve population.The mortality (%) as per time of balloon insertion was: Preoperative 18.2, Intraopeartive 33.3, postoperative 58.3 (p < 0.05).The incremental risk factors for death were: Female gender (Odds Ratio (OR) = 3.87 with Confidence Intervals (CI) = 1.3-11.6), Smoking (OR = 4.88, CI = 1.23- 19.37), Preoperative Creatinine>120 (OR = 3.3, CI = 1.14-9.7), Cross Clamp time>80 min (OR = 4.16, CI = 1.73-9.98) and IABP insertion postoperatively (OR = 19.19, CI = 3.16-116.47).The incremental risk factors for the development of complications were: Poor EF (OR = 3.16, CI = 0.87-11.52), Euroscore >7 (OR = 2.99, CI = 1.14-7.88), history of PVD (OR = 4.99, CI = 1.32-18.86).The 5 years survival was 79.2% for the CABG population and 71.5% for the valve group. (Hazard ratio = 1.78, CI = 0.92-3.46).ConclusionsIABP represents a safe option of supporting the failing heart. The need for IABP especially in a high risk Valve population is associated with early unfavourable outcome, however the positive mid term results further justify its use.

Bronchial carcinoid of an accessory tracheal bronchus.

We present a rare case of bronchial carcinoid tumor arising in an accessory right tracheal bronchus and involving the associated tracheal lobe in a 48-year-old man, who presented with a history of recurrent respiratory infections and recent onset of hemoptysis. Diagnosis was established on preoperative bronchoscopy and biopsy. The tumor was completely removed by right upper lobectomy with the tracheal bronchus resected flush to its origin from the right lower tracheal wall. Final histology revealed a typical carcinoid tumor.

What is the best approach in a patient with a failed aortic bioprosthetic valve: transcatheter aortic valve replacement or redo aortic valve replacement?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether transcatheter aortic valve-in-valve replacement (viv-TAVR) or redo aortic valve replacement (rAVR) is the best strategy in a patient with a degenerative bioprosthetic aortic valve. Altogether, 162 papers were found using the reported search, of which 12 represented the best evidence to answer the question. The authors, journal, date, country of publication, patient group, study type, outcomes and results of papers are tabulated. The results of the studies provided interesting results. All the studies are retrospective. Four papers reported the results of redo aortic valve replacement in patients with failed aortic bioprosthetic valve, six papers demonstrated their results with transcatheter aortic valve-in-valve replacement for the same indication and two papers reported their propensity-matched analysis of outcomes between viv-TAVR and rAVR in patients with previous cardiac surgery. Thirty-day mortality for rAVR was 2.3-15.5% and 0-17% for viv-TAVR. For rAVR, survival rate at 30 days was 83.6%, 76.1% at 1 year, 70.8% at 3 years, at 51.3-66% at 5 years, 61% at 8 years and 61.5% at 10 years. For viv-TAVR, the overall Kaplan-Meier survival rate at 1 year was 83.2%. After viv-TAVR at 1 year, 86.2% of surviving patients were at New York Heart Association (NYHA) class I/II. The complications after rAVR were stroke (4.6-5.8%), reoperation for bleeding (6.9-9.7%), low-cardiac output syndrome (9.9%) whereas complications after viv-TAVR at 30 days were major stroke (1.7%), aortic regurgitation of at least moderate degree (25%), new permanent pacemaker implantation rate (0-11%), ostial coronary obstruction (2%), need for implantation of a second device (5.7%) and major vascular complications (9.2%). It is noteworthy to mention that there is a valve-in-valve application that provides information to surgeons for choosing the correct size of the TAVR valve. Transcatheter aortic valve-in-valve procedures are clinically effective, at least in the short term, and could be an acceptable approach in selected high-risk patients with degenerative bioprosthetic valves. Redo AVR achieves acceptable medium and long-term results. Both techniques could be seen as complementary approaches for high-risk patients.