Myocardial oxygen consumption during histidine-tryptophan-ketoglutarate cardioplegia in young human hearts.

OBJECTIVES: Energy demand and supply need to be balanced to preserve myocardial function during paediatric cardiac surgery. After a latent aerobic period, cardiac cells try to maintain energy production by anaerobic metabolism and by extracting oxygen from the given cardioplegic solution. Myocardial oxygen consumption (MVO2) changes gradually during the administration of cardioplegia. METHODS: MVO2 was measured during cardioplegic perfusion in patients younger than 6 months of age (group N: neonates; group I: infants), with a body weight less than 10 kg. Histidine-tryptophan-ketoglutarate crystalloid solution was used for myocardial protection and was administered during a 5-min interval. To measure pO2 values during cardioplegic arrest, a sample of the cardioplegic fluid was taken from the inflow line before infusion. Three fluid samples were taken from the coronary venous effluent 1, 3 and 5 min after the onset of cardioplegia administration. MVO2 was calculated using the Fick principle. RESULTS: The mean age of group N was 0.2 ± 0.09 versus 4.5 ± 1.1 months in group I. The mean weight was 3.1 ± 0.2 versus 5.7 ± 1.6 kg, respectively. MVO2 decreased similarly in both groups (min 1: 0.16 ± 0.07 vs 0.36 ± 0.1 ml/min; min 3: 0.08 ± 0.04 vs 0.17 ± 0.09 ml/min; min 5: 0.05 ± 0.04 vs 0.07 ± 0.05 ml/min). CONCLUSIONS: We studied MVO2 alterations after aortic cross-clamping and during delivery of cardioplegia in neonates and infants undergoing cardiac surgery. Extended cardioplegic perfusion significantly reduces energy turnover in hearts because the balance procedures are both volume- and above all time-dependent. A reduction in MVO2 indicates the necessity of a prolonged cardioplegic perfusion time to achieve optimized myocardial protection.

Tetralogy of Fallot whit a "contralateral" ductus arteriosus.

Two neonates were taken shortly after birth to our unit with a prenatal diagnosis of [S,D,S] Tetralogy of Fallot with pulmonary atresia and "unusual" aorta to pulmonary connection. The echocardiogram confirmed the main diagnosis showing: a left aortic arch with a vascular connection between the right innominate artery and the origin of the right pulmonary artery in patient A; and right aortic arch with a vascular connection between the left innominate artery and the origin of the left pulmonary artery in patient B.

Conventional versus frozen elephant trunk surgery for extensive disease of the thoracic aorta.

OBJECTIVE: To compare early and mid-term outcomes after repair of extensive aneurysm of the thoracic aorta using the conventional elephant trunk or frozen elephant trunk (FET) procedures. METHODS: Fifty-seven patients with extensive thoracic aneurysmal disease were treated using elephant trunk (n = 36) or FET (n = 21) procedures. Patients with aortic dissection, descending thoracic aorta (DTA) diameter less than 40 mm, and thoracoabdominal aneurysms were excluded from the analysis, as were those who did not undergo antegrade selective cerebral perfusion during circulatory arrest. Short-term and mid-term outcomes were compared according to elephant trunk/FET surgical management. RESULTS: Preoperative and intraoperative variables were similar in the two groups, except for a higher incidence of female sex, coronary artery disease and associated procedures in elephant trunk patients. Hospital mortality (elephant trunk: 13.9% versus FET: 4.8%; P = 0.2), permanent neurologic dysfunction (elephant trunk: 5.7% versus FET: 9.5%; P = 0.4) and paraplegia (elephant trunk: 2.9% versus FET: 4.8%; P = 0.6) rates were similar in the two groups. Follow-up was 100% complete. In the elephant trunk group, 68.4% of patients did not undergo a second-stage procedure during follow-up for a variety of reasons. Of these patients, the DTA diameter was greater than 51 mm in 72.2% and two (6.7%) died due to aortic rupture while awaiting stage-two intervention. Endovascular second-stage procedures were successfully performed in all FET patients with residual DTA aneurysmal disease (n = 3), whereas nine of 11 elephant trunk patients who returned for second-stage procedures required conventional surgical replacement through a lateral thoracotomy. Kaplan-Meier estimate of 4-year survival was 75.8 ±â€Š7.6 and 72.8 ±â€Š10.6 in elephant trunk and FET patients, respectively (log-rank P = 0.8). CONCLUSION: In patients with extensive aneurysmal disease of thoracic aorta, elephant trunk and FET procedures seem to be associated with similar satisfactory early and mid-term outcomes. The FET approach leads to single-stage treatment of all aortic disease in most patients, and facilitates endovascular second-stage treatment in patients with residual DTA disease. The elephant trunk staged-approach appears to leave a considerable percentage of patients at risk for adverse aortic events.

Impact of different cannulation strategies on in-hospital outcomes of aortic arch surgery: a propensity-score analysis.

BACKGROUND: The impact of different cannulation strategies on outcomes of aortic arch surgery remains controversial. This retrospective study sought to evaluate central cannulation (ascending aorta, right axillary, and innominate artery) compared with femoral artery cannulation for aortic arch surgery, and to identify among preoperative and intraoperative variables the independent predictors of death and permanent neurologic dysfunction (PND) in aortic arch surgery. METHODS: All patients were operated through a median sternotomy using antegrade selective cerebral perfusion with moderate hypothermia as a method of brain protection. Treatment bias was addressed by use of propensity-score matching and multivariate regression analysis. Logistic regression models were used to identify the independent predictors of hospital mortality and PND. RESULTS: Of the 473 patients undergoing aortic arch surgery, 273 (57.7%) underwent femoral cannulation (FC), and 200 (42.3%) underwent central cannulation (CC). The CC and FC cannulation were associated with similar risk of in-hospital death (absolute risk reduction [ARR]: 0.7%; p = 0.880) and PND (ARR:-2.6%, p = 0.361) in the overall cohort and after adjusting for propensity-based matching (ARR for hospital mortality: 2.2%, p = 0.589; ARR for PND: 3.4%, p = 0.271). Female gender (odds ratio [OR]:2.1, p = 0.030), type A acute dissection or intramural hematoma (OR: 2.2; p = 0.041), and CPB time (OR: 1.010/minute, p = 0.015) were independent predictors of in-hospital death. Female gender (OR: 2.4; p = 0.033), type A acute dissection or intramural hematoma (OR: 4.2; p = 0.005), and diabetes (OR: 6.6, p = 0.007) were independent predictors of PND. CONCLUSIONS: During aortic arch surgery, CC and FC are associated with a similar risk of postoperative death and PND. Type A acute aortic dissection and cardiopulmonary bypass time remain strong risk factors for mortality and PND.

Delayed management of blunt traumatic aortic injury: open surgical versus endovascular repair.

BACKGROUND: A growing body of evidence has shown that delayed management of traumatic injury of the thoracic aorta determines survival benefits as compared with immediate treatment. However, few data exist comparing outcomes after delayed open surgical or endovascular management. Accordingly, we reviewed our experience with delayed management, stratifying the data according to type of repair; open surgical versus endovascular. METHODS: Since 1992, delayed aortic repair has represented our first-line management for all blunt traumatic thoracic aortic injury (BTTAI) patients, except for those who presented with or became unstable due to impending aortic rupture. These patients were converted to urgent primary aortic repair. Thus, between 1992 and 2010, a total of 77 BTTAI patients were managed according to this policy. There were 57 (74%) men having a mean age of 33.4 years. Thirty-one (41.3%) patients underwent open surgical repair (SR), 44 (58.6%) underwent endovascular repair (ER), and 2 died while awaiting aortic repair. At admission, the clinical and trauma characteristics were similar in both groups. The trauma-to-repair time span (in days) was 200 (Q1-Q3: 27 to 340) and 10 (Q1-Q3: 2 to 79) for SR and ER patients, respectively (p = 0.001). Due to unpaired hemodynamic or imaging signs of impending aortic rupture, 15 patients required urgent repair, which was endovascular in 11 (25%) cases and surgical in 4 (12.9%). RESULTS: Overall, hospital mortality was 3.9% (n = 3), being 0% in SR patients and 2.3% (n = 1) in ER patients (p = 0.398). No new postoperative paraplegia occurred; a cerebellar stroke occurred in 1 (2.3%) ER patient receiving intentional coverage of the left subclavian artery. During follow-up (96.1% complete at 95 ± 70 months), no late deaths occurred. At 15 years, the estimates of survival and freedom from secondary aortic procedures were 96% and 100%, respectively. CONCLUSIONS: Delayed management of traumatic aortic injury was associated with satisfactory short- and long-term results without significant differences between open surgical and endovascular repair. However, the reduced invasiveness of endovascular repair can optimize operative timing allowing prompt aortic repair in unstable patients, earlier repair in stable patients, and, when indicated, easier concomitant non-aortic surgery.

Reoperative surgery on the thoracic aorta.

OBJECTIVE: The objective of our study was to report our hospital and long-term results after reinterventions on the thoracic aorta. METHODS: Between 1986 and 2011, 224 reoperations on the proximal thoracic aorta after previous aortic surgery were performed in our institution. The number of reinterventions quadrupled during the course of the study period. Mean patient age was 58.1 years, and 174 patients (77.7%) were male. An urgent/emergency operation was performed in 39 patients (17.4%). Indications for surgery included degenerative and chronic postdissection aneurysm (n = 166), false aneurysm (n = 31), active prosthetic infection (n = 16), acute dissection (n = 10), and other (n = 1). Surgical procedures involved the aortic root in 40.6% of patients, the ascending aorta in 9.4%, the aortic arch in 24.6%, and the entire proximal thoracic aorta in 25.4%. RESULTS: Hospital mortality was 12.1%. On multivariate analysis, cardiopulmonary bypass time (odds ratio, 1.1023/minute; P < .001), and urgent/emergency status (odds ratio, 5.6; P < .001) emerged as independent predictors of hospital mortality. The follow-up was 98.7% complete. Estimated 1-, 5-, and 10-year survival rates were 84.4%, 72.5%, and 48.5%, respectively. Eighteen reinterventions were performed during follow-up-16 because of the progression of aortic disease at the proximal aorta (n = 2) and downstream aorta (n = 14). Freedom from reoperation at 1, 5, and 10 years was 95.6%, 90.2%, and 81.5%, respectively. CONCLUSIONS: Reoperative aortic surgery was associated with satisfactory short- and long-term results, especially if carried out on an elective basis. The extent of the aortic replacement did not impact survival and was associated with a reduced need for reintervention. The progressive nature of aortic disease and the favorable results of elective primary aortic interventions suggest favoring aggressive aortic resections at initial surgery.

Re-operations on the proximal thoracic aorta: results and predictors of short- and long-term mortality in a series of 174 patients.

OBJECTIVE: The aim of this study was to report results and to identify predictors of hospital and long-term mortality in patients undergoing re-operations on the proximal thoracic aorta. METHODS: Between 1986 and 2009,174 re-operations on the proximal thoracic aorta after previous aortic surgery were performed in our Institution. The patients' mean age was 58 years, 132 (75.9%) were men. The mean time from last operation was 9.9 years. An urgent operation was performed in 35 (20.1%) patients. Indications for surgery included degenerative and chronic post-dissection aneurysm (n=133), acute dissection (n=8), false aneurysm (n=22), and active prosthetic infection (n=11). Root procedures were performed in 65 (37.3%) patients, ascending aorta replacement in 27 (15.5%), different extents of aortic arch replacement in 39 (22.4%), and root, ascending aorta and arch replacement in 43 (24.7%). RESULTS: Hospital mortality was 12.6%. On multivariate analysis, cardiopulmonary bypass (CPB) time (odds ratio (OR)=1.1018 per min), New York Heart Association (NYHA) class III-IV (OR=3.86), and active endocarditis (OR=5.15) emerged as independent predictors of hospital mortality. Mean follow-up time was 56 months. The estimated 1-, 5-, and 10 years' survival were 81.6%, 74.2%, and 44.5%, respectively. On Cox regression analysis, age (hazard ratio (HR)=1.037 per year) and CPB time (HR=1.010 per min) emerged as independent risk factors of late mortality. CONCLUSIONS: Short- and long-term survival was satisfactory being excellent in patients with degenerative aneurysms and dismal in those with active endocarditis. Extensive aortic resections did not increase hospital mortality and were associated with a reduced need for aortic re-interventions. CPB time remains the most important risk factor for reduced survival in aortic surgery.

Facilitated aortic arch repair with the frozen elephant trunk technique.

The frozen elephant trunk, combining together surgical and endovascular techniques, has been developed to treat patients with extensive disease of the thoracic aorta. In this article, we report three cases in which the frozen elephant trunk could facilitate surgical arch repair and patients' management.

Aortic valve-sparing operations.

Ascending aortic aneurysms involving the aortic root are usually treated with replacement of the ascending aorta and the aortic valve using a composite valved conduit. However, the aortic valve is usually normal and the dysfunction is due to an impairment of the other components of the aortic root. In these cases, the aortic root can be replaced, sparing the native aortic valve. Aortic valve-sparing operations have been demonstrated to be effective and durable. This article summarizes the principal methods of valve-sparing procedures, and describes the advantages and disadvantages of each method, and their impact on patient outcomes.