Nestoras Papadopoulos

Selective antegrade cerebral perfusion and mild (28°C-30°C) systemic hypothermic circulatory arrest for aortic arch replacement: results from 1002 patients.

OBJECTIVES The use of selective antegrade cerebral perfusion (ACP) makes deep hypothermia nonessential for aortic arch replacement. Consequently, a growing tendency to increase the body temperature during circulatory arrest with ACP has recently been reported from various institutions. However, very little is known about the clinical effect of different modes of ACP (unilateral vs bilateral) on neurologic morbidity. Also, the safe limits of this approach for spinal chord and visceral organ protection are yet to be defined. METHODS Between January 2000 and January 2011, 1002 consecutive patients underwent aortic arch repair during ACP (unilateral, 673; bilateral, 329) with mild systemic hypothermia (30°C ± 2°C; range, 26°-34°C) at 2 centers in Germany. The mean patient age was 62 ± 14 years, 663 patients (66%) were men, and 347 patients (35%) had acute type A dissection. Hemiarch replacement was performed in 684 patients (68%), and 318 (32%) underwent total arch replacement. RESULTS The cardiopulmonary bypass time accounted for 158 ± 56 minutes and the myocardial ischemic time, 101 ± 41 minutes. Isolated ACP was performed for 36 ± 19 minutes (range, 9-135). We observed new postoperative permanent neurologic deficits in 28 patients (3%; stroke in 25 and paraplegia in 3) and transient neurologic deficits in 42 patients (4%). All 3 cases of paraplegia occurred in patients with acute type A dissection and a broad range of ACP times (24, 41, and 127 minutes). A trend was seen toward a reduced permanent neurologic deficit rate after unilateral ACP (P = .06), but no difference was seen in the occurrence of transient neurologic deficits (P = .6). Overall, the early mortality rate was 5% (n = 52). Temporary dialysis was necessary primarily after surgery in 38 patients (4%). When corrected for the unequal distribution of type A dissection, neurologic morbidity, early mortality, and the need for temporary dialysis were independent of the duration of ACP and were not affected by unilateral versus bilateral ACP. CONCLUSIONS Current data suggest that ACP and mild systemic hypothermic circulatory arrest can be safely applied to complex aortic arch surgery even in a subgroup of patients with up to 90 minutes of ACP. Unilateral ACP offers at least equal brain and visceral organ protection as bilateral ACP and might be advantageous in that it reduces the incidence of embolism arising from surgical manipulation on the arch vessels.

Long-Term Results After Surgical Repair of Postinfarction Ventricular Septal Rupture by Infarct Exclusion Technique

BACKGROUND Ventricular septal defect (VSD) is one of the most serious and life-threatening complications of acute myocardial infarction. The aim of this study was to evaluate the early and long-term results of the patients after surgical repair of postinfarction VSD by infarct exclusion technique. METHODS A total of 32 consecutive patients (mean age, 62.5 +/- 10.5 years) underwent postinfarction VSD repair using a standardized technique in our department. A retrospective analysis of clinical and operative data, predictors of early mortality, and long-term survival was performed. The localization of VSD was posterior in 50% and anterior in 50% of the patients. RESULTS The hospital mortality was 31.2% (10 patients). The most common cause of hospital death was persistent low cardiac output. The mortality of the posterior VSD group was significantly lower than that of the anterior VSD group (18.7% and 43.7%, respectively, p = 0.01). Intra-aortic balloon pump support and absence of cardiac shock were significantly associated with a lower risk of hospital mortality (p = 0.0001 and p = 0.0009, respectively). The actuarial survival rates of in-hospital survivors at 5 and 10 years were 79% +/- 2% and 51% +/- 3%, respectively. CONCLUSIONS The repair of postinfarction VSD by the infarct exclusion is feasible and safe. This technique seems to offer sufficient favorable early and long-term results compared with other techniques. Early indication, preoperative intra-aortic balloon pump support may improve the surgical results. Preoperative cardiogenic shock carries a poor prognosis for this patient group.

Surgical repair for acute type A aortic dissection in octogenarians.

BACKGROUND Despite limited data, the necessity for immediate surgical intervention in octogenarians with acute type A aortic dissection (AAD) has recently been questioned because the surgical risk may outweigh its potential benefits. At the same time, evolving stent graft technologies are pushing in the market for pathology within the ascending aorta, even for treatment of AAD. Against this background, we analyzed our institutional experience in this patient cohort during the last 8 years. METHODS Between October 2005 and October 2013, 39 patients aged older than 80 years (82 ± 2 years) underwent surgical repair for AAD, of which 29 patients (74%) were men. Owing to patient age and comorbidities, we aimed to limit the operation to supracoronary hemiarch replacement whenever possible. Clinical data were prospectively entered into our institutional database. Late follow-up was 3.6 ± 2.8 years and was 100% complete. RESULTS Hemiarch replacement was performed in 32 patients (82%), and full arch replacement was necessary in the remaining 7. In 31 patients (79%), the aortic root could be glued and reconstructed or remained untouched. The remaining 8 patients (21%) underwent the bio-Bentall procedure. Mean ventilation time was 46 ± 23 hours, and the intensive care unit stay was 5 ± 9 days. We observed new postoperative permanent neurologic deficits in 2 patients (5%) and transient neurologic deficits in 3 (8%). The 30-day mortality was 26% (n = 10). Kaplan-Meier estimates for late survival were 46% ± 16% at 5 years. CONCLUSIONS Given the guidelines regarding the predicted risk of death in patients with untreated AAD, current data suggest a survival benefit with immediate open surgical intervention even in octogenarians. Similarly to the early days of transcatheter-based aortic valve implantation, open surgical reference data are warranted to set the bar for upcoming endovascular treatment of AAD in octogenarians.

Multiple Electrode Aggregometry for the Assessment of Acquired Platelet Dysfunctions during Extracorporeal Circulation

BACKGROUND There have been many reports on how the usage of extracorporeal circulation (ECC) is independently associated with the induction of platelet dysfunctions. The aim of the present investigation was to study the capability of the multiple electrode aggregometry (MEA) using the Multiplate (Roche AG, Grenzach, Germany) device to reflect the extent of ECC-associated platelet dysfunctions. PATIENTS AND METHODS The study population consisted of patients who were treated with either hypothermic (cardiopulmonary bypass [CPB]) or normothermic (extracorporeal membrane oxygenation) ECC. Hemostatic analyses included conventional laboratory coagulation tests and aggregometric measures following stimulation with different agonists using MEA. The area under the aggregation curve in the ADPtest (ex vivo adenosine diphosphate induced platelet aggregation) of the MEA was defined as the primary end point. The analyses were performed before the usage of ECC (baseline) and 90 minutes (T1), 120 minutes (T2), 150 minutes (T3), and 180 minutes (T4) after the usage of ECC. In the hypothermic ECC group, additional hemostatic analyses were performed after the patients postoperative admission to the intensive care unit (T5). Periprocedural data and results of other hemostatic testing were defined as secondary end points. RESULTS A total of n = 40 patients were assessed for eligibility and n = 25 patients were finally enrolled into the study (hypothermic ECC group: n = 20; normothermic ECC group: n = 5). The extent of ADP-induced platelet aggregation decreased significantly between baseline and consecutive measuring points during hypothermic ECC and remained unchanged between T4 and T5. In the normothermic ECC group, ADP-induced aggregability was significantly lower at T1 compared with baseline and remained unchanged from T1 onward. CONCLUSION Data from the present study indicate that ex vivo ADP-induced platelet aggregation in MEA reflects the time-dependent extent of ECC-induced platelet dysfunction.

Midterm Survival After Decalcification of the Mitral Annulus

BACKGROUND The aim of this study is to determine the midterm outcomes of patients who underwent decalcification and patch-reconstruction of the mitral annulus during mitral valve surgery in our department. METHODS Between 1996 and 2004, a total of 81 consecutive patients with a mean age of 64 +/- 13 years underwent mitral valve surgery in the presence of extensive calcification of mitral annulus. In the majority of cases (n = 42, 52%), a mitral valve repair was performed after decalcification and patch-reconstruction of the mitral annulus. The remaining 39 patients (48%) received a mitral valve prosthesis (biological n = 20, mechanical n = 19). Retrospective analysis of preoperative, operative, and postoperative information of these 81 patients was performed. The follow-up period ranged between 4 and 10 years (mean follow-up, 5.8 +/- 3.1). RESULTS The 30-day mortality was 8.7% (n = 7). The actuarial survival rates at 5 years were 79% +/- 3%. At the latest follow-up, 34 patients (55.7%) were in New York Heart Association class I, 23 (37.7%) were in class II, and 4 (6.5%) were in class III. The freedom from reoperation at 5 years was 90.5% +/- 2%. There was only 1 stroke (1.6%), which occurred 1 year after the operation. CONCLUSIONS These results show that despite the increased perioperative risk and the difficult approach of the pathology in this patient group, decalcification and patch-reconstruction of the mitral annulus during mitral valve surgery can be performed safely with satisfactory and stable clinical midterm results.

Risk factors associated with adverse outcome following extracorporeal life support: analysis from 360 consecutive patients

Objective: Risk factors for adverse outcome after extracorporeal life support (ECLS) are yet to be defined. For this purpose, we reviewed our institutional data from more than a decade, focusing on patients with ECLS. Methods: Between December 2001 and June 2013, 360 consecutive cardiac surgical patients received ECLS for post-cardiotomy cardiogenic shock, with high mortality risk despite optimal conventional therapy. Patient demographics, clinical characteristics, ECLS-related morbidity, as well as in-hospital and long-term mortality were analysed. Multivariate logistic regression analysis was performed to identify independent predictors of adverse outcome (failed ECLS weaning, in-hospital mortality). Results: The mean age was 62±17 years, 76% were male and the mean preoperative ejection fraction was 35±16%. ECLS was established through peripheral (90%) or central thoracic cannulation. The mean duration of ECLS was 7±1 days. Intra-aortic balloon pumps were implanted in 22% of the patients. ECLS weaning was successful in 58% and 30% could be discharged from hospital. The main cause of death was sepsis (69%). Overall, major cerebrovascular events occurred in 12% (bleeding 3%, embolic 9%), limb ischaemia in 13%, gastrointestinal complications in 16% and renal replacement therapy in 61%. Independent risk factors for adverse outcome were prior cardiorespiratory resuscitation (OR: 4.1, 95%CI: 0.34-4.21, p=0.04), pH <7.1 (OR: 2.8, 95%CI: 0.45-3.28, p=0.01), serum lactate >120 mg/dL (OR: 2.6, 95%CI: 0.75-2.96, p< 0.01), norepinephrine dosage >0.5 µg/kg/min (OR: 2.4, 95%CI: 0.35-2.92, p=0.02) and age >75 years (OR: 2.0, 95%CI: 0.41-2.88, p=0.02). Kaplan Meier estimates for long-term survival were 26±3% at one year and 22±2% at five years. Conclusion: ECLS therapy offers one-year survival to one quarter of patients with an otherwise fatal prognosis. Procedural mortality is low and morbidity at the implantation site typically moderate. Thus, prolonged metabolic deterioration in combination with high-dose vasopressor support prior to ECLS therapy should be avoided, particularly in younger patients.

The effect of normovolemic modified ultrafiltration on inflammatory mediators, endotoxins, terminal complement complexes and clinical outcome in high-risk cardiac surgery patients.

Objective: The clinical benefit of normovolemic modified ultrafiltration (N-MUF) after cardiac surgery is still debated. As we have shown in a previous publication, there is a significant improvement in platelet function, so we were interested in whether ultrafiltration can reduce plasma levels of endotoxins, terminal complement complexes and cytokines after cardiopulmonary bypass (CPB) in adults with increased risk profiles. Methods: In this single-center, prospective, randomized trial, fifty high-risk patients (mean logistic EuroSCORE II: 17.5%) who underwent cardiac surgery were randomized. After CPB, Group 1 (n = 25) served as the control and in, Group 2 (n= 25), an N-MUF of 3000 ml was performed, using a BC140plus filter after weaning from CPB. Blood samples were taken after the induction of anesthesia, before CPB, before CPB weaning, 30 minutes after CPB and at 6, 24 and 48 hours postoperatively. Primary outcomes were plasma levels of lipopolysaccharide-binding protein (LBP), terminal complement complex (C5b9) and cytokines (IL-6, IL-10, IL-1beta, TNF-α). Secondary outcomes focused on differences in the clinical outcome. Results: A significant reduction in LBP concentration (preoperatively: 23.8±8.4 pg/ml, postoperatively: 14.2±12.9 pg/ml) and C5b9 (preoperatively: 4.18±2.6 pg/ml, postoperatively: 3.05±2.39 pg/ml) were detected 6 hours after N-MUF. In the N-MUF group, significantly lower concentrations of lactate could be detected in the early postoperative period. Furthermore, postoperative chest tube blood loss was significantly lower in the N-MUF group at 24 and 48 hours. Conclusions: N-MUF leads to a significant reduction of lipopolysaccharide-binding protein and terminal complement complex and was associated with reduced blood loss and postoperative lactate concentrations shortly after surgery.

Secondary Repair of Incompetent Pulmonary Valves

BACKGROUND Secondary repair of the pulmonary valve after right ventricular outflow tract (RVOT) reconstruction is infrequently reported. This article describes possible techniques of secondary pulmonary valve repair and reports follow-up results. METHODS Secondary pulmonary valve repairs in 7 patients (5 children and 2 adults) in our institution were reviewed. All patients presented with a severe pulmonary valve regurgitation associated with RV dilatation and dysfunction after primary RVOT reconstruction. RESULTS The surgical techniques varied in our series, but secondary repair of the incompetent pulmonary valve was possible in all patients. Follow-up was complete, with a mean follow-up of 4.1 +/- 2.7 years. There were no operative or late deaths in our group. All valves were repaired successfully, with a mean regurgitation grade of 1.28 +/- 0.5 postoperatively. The mean transvalvular gradient was 20 +/- 4.1 mm Hg for children and 22.5 +/- 3.5 mm Hg for adults, and no significant increase of pulmonary valve regurgitation occurred during follow-up. The mean RV dilatation index (RVDI) decreased significantly from 0.85 +/- 0.25 to 0.6 +/- 0.2 for children and from 1.4 +/- 0.01 to 0.9 +/- 0.05 for adults. CONCLUSIONS Our results showed functional recovery of the right ventricle after reoperation, with RVDI recovering to almost normal values in children. No significant regurgitation of the secondarily reconstructed pulmonary valve was observed during the 4-year follow-up period. Secondary repair for pulmonary valve incompetence after RVOT procedures might be a valuable alternative to conduit replacement.

Transapical Aortic Valve Implantation in Patients With Previous Cardiac Surgery

BACKGROUND This study compared surgical outcomes of patients with previous cardiac surgery undergoing transapical transcatheter aortic valve implantation (PCS-TA-TAVI) with those of patients undergoing transapical transcatheter aortic valve implantation as an initial procedure (initial TA-TAVI) by using propensity analysis. METHODS From January 2005 through January 2013, 267 consecutive high-risk patients underwent transapical transcatheter aortic valve implantation using a pericardial xenograft fixed within a stainless steel, balloon-expandable stent (Edwards SAPIEN). Of these, 59 patients underwent PCS-TA-TAVI (coronary artery bypass grafting: n = 31; valve surgery: n = 28), and the remaining 208 had an initial TA-TAVI procedure. Logistic regression analysis was used to identify covariates among 10 baseline patient variables. Using the significant regression coefficients, each patients propensity score was calculated, allowing selectively matched subgroups of 45 patients in the two groups. Operative outcomes were analyzed for differences. Follow-up was 4 ± 2 years and 100% complete. RESULTS There was no significant difference between PCS-TA-TAVI and initial TA-TAVI patients in operative time, postoperative bleeding, 30-day survival (91% versus 93%), and survival at late follow-up (63% versus 68%; p ≥ 0.28). Overall incidence of early stroke was low with 0% for the PCS-TA-TAVI and 4% for initial TA-TAVI group (p = 0.56). Transapical transcatheter aortic valve implantation was successfully performed in all but 1 patient from the initial TA-TAVI group who required conversion to sternotomy. CONCLUSIONS Transapical transcatheter aortic valve implantation has simplified surgical treatment of high-risk patients with previous cardiac surgery and severe aortic valve stenosis and is associated with minimal risk of stroke. Furthermore, current data suggest that the presence of previous cardiac surgery does not impair outcomes after transapical transcatheter aortic valve implantation, making this subset of patients particularly applicable for this evolving approach.

Normovolemic modified ultrafiltration is associated with better preserved platelet function and less postoperative blood loss in patients undergoing complex cardiac surgery: A randomized and controlled study

OBJECTIVE The purpose of the investigation was to study the impact of normovolemic modified ultrafiltration (N-MUF) on hemostasis and perioperative blood loss. METHODS Fifty patients scheduled for elective complex cardiac surgery were enrolled in this prospective, randomized, and controlled study. Patients were randomized into a control group (n = 25) or an N-MUF group (n = 25). N-MUF was performed using a BC140plus Filter (Maquet Cardiopulmonary AG, Hirrlingen, Germany) in the N-MUF group. Blood samples were taken before (T1) and 30 minutes after (T2) N-MUF in the N-MUF group and at corresponding time points in the control group. Platelet function analyses (TRAPtest, ASPItest, ADPtest) using multiple electrode aggregometry (Multiplate, Dynabyte, Munich, Germany), thrombelastometry (ROTEM, Pentapharm GmbH, Munich, Germany), and conventional laboratory coagulation analyses were performed at each time point. Intraoperative and postoperative transfusion requirements, hemostatic therapy, and blood loss were recorded. RESULTS There were no significant group differences in demographic or surgical data. At T1, platelet aggregation revealed no significant group differences in the TRAPtest, ASPItest, or ADPtest. Platelet aggregation at T2 was significantly higher in the N-MUF group compared with the control group in the TRAPtest (65 [50/87] U vs 44 [28/51]; P < .001), the ASPItest (52 [36/69] U vs 22 [8/47] U; P = .001), or the ADPtest (39 [28/51] U vs 28 [19/39] U; P = .009). The postoperative chest tube blood loss was significantly lower in the N-MUF at 24 hours (890 [500/1100] mL vs 1075 [800/1413] mL in the N-MUF group vs the control group; P = .039) and 48 hours (900 [550/1350] mL vs 1400 [900/1750] mL; P = .026) postoperatively. Conventional laboratory coagulation analyses and thrombelastometric parameters did not differ within the groups at T1 or T2. CONCLUSIONS N-MUF improved general platelet aggregation and reduced postoperative blood loss in a significant manner. However, performing N-MUF did not result in less postoperative transfusion requirements.