Felix Haas

Preoperative Positron Emission Tomographic Viability Assessment and Perioperative and Postoperative Risk in Patients With Advanced Ischemic Heart Disease

OBJECTIVES This study sought to investigate whether determination of tissue viability by means of positron emission tomography (PET) before coronary artery bypass graft surgery (CABG) affects clinical outcome with respect to both in-hospital mortality and 1-year survival rate. BACKGROUND Patients with coronary artery disease (CAD) and severe left ventricular (LV) dysfunction are at higher risk for perioperative complications associated with CABG. Therefore, the selection of patients who will benefit from CABG is an important clinical issue. METHODS This study retrospectively evaluated 76 patients with advanced CAD and LV dysfunction (LV ejection fraction < or = 0.35) who were considered candidates for CABG. Thirty-five patients were selected for CABG on the basis of clinical presentation and angiographic data (group A), and 34 of 41 patients were selected according to extent of viable tissue determined by PET (group B) in addition to clinical presentation and angiographic data. RESULTS There were four in-hospital deaths (11.4%) in group A and none in group B (p = 0.04). After 12 months, the survival rate was 79% in group A and 97% in group B (p = 0.01). Postoperatively, group B patients had a less complicated recovery (p = 0.05). They required lower doses of catecholamines (p = 0.002) and demonstrated a significantly decreased incidence of low output syndrome (p = 0.05). CONCLUSIONS This retrospective data analysis suggests that selection of patients with impaired LV function on the basis of extent of viability supplementary to clinical and angiographic data may lead to postoperative recovery with a low early mortality and promising short-term survival. Therefore, viability studies permit selection of patients who are at low risk for serious perioperative complications.

Long-term survival and functional follow-up in patients after the arterial switch operation

BACKGROUND For many years, the arterial switch operation (ASO) has been the therapy of choice for patients with transposition of the great arteries (TGA). Although excellent short- and mid-term results were reported, long-term results are rare. METHODS Between May 1983 and September 1997, ASO was performed on 285 patients with simple TGA (n = 171), TGA with ventricular septal defect (VSD) (n = 85), and Taussig-Bing (TB) anomaly (n = 29). This retrospective study describes long-term morbidity and mortality over a 15-year period. RESULTS Hospital mortality was 3.5% for simple TGA, 9.4% for TGA with VSD, and 13.8% for TB anomaly. Late death occured in 2 patients, 1 with simple TGA and 1 with TGA and VSD. The cumulative survival for all patients at 5 and 10 years is 93%, and at 15 years is 86%. Reoperations were required in 31 patients and were most common for stenosis of the right ventricular outflow tract (RVOT). However, no correlation was found between technical variations on pulmonary artery reconstruction and this type of complication. Forty-six patients underwent follow-up angiography, which revealed five cases with coronary occlusion or stenosis. Follow-up is complete in 96% of the patients from 1 to 15.2 years. Sinus rhythm is present in 97%; 88% of the patients show no limitations on exertion. CONCLUSIONS The ASO can be performed with low early mortality, almost absent late mortality, and infrequent need for reoperation. The favorable long-term results demonstrate that the ASO can be considered as the optimal approach for patients with TGA and special forms of double-outlet right ventricle.

A prospective study of paediatric cardiac surgical microsystems: assessing the relationships between non-routine events, teamwork and patient outcomes

Objective Paediatric cardiac surgery has a low error tolerance and demands high levels of cognitive and technical performance. Growing evidence suggests that further improvements in patient outcomes depend on system factors, in particular, effective team skills. The hypotheses that small intraoperative non-routine events (NREs) can escalate to more serious situations and that effective teamwork can prevent the development of serious situations were examined to develop a method to assess these skills and to provide evidence for improvements in training and performance. Methods This mixed-method design, using both quantitative and qualitative measures, relied on trained human factor observers who observed and coded NREs and teamwork elements from the time of patient arrival into the operating room to patient handover to the intensive care unit. Real-time teamwork observations were coupled with microsystem preparedness measures, operative duration, assessed difficulty of the operation and patient outcome measures. Behaviour was rated based on whether it hindered or enhanced teamwork. Results 40 paediatric cardiac surgery cases were observed. Surgeons displayed better teamwork during complicated procedures, particularly during the surgical bypass/repair epoch. More procedural NREs were associated with a more complicated postoperative course (Muncomplicated=9.08; Mminor complications=11.11; Mmajor morbidity=14.60, F(2,26)=3.46, p<0.05). Procedural NREs decreased substantially over time (M1=13.5; M2=7.1, F(1,37)=33.07, p<0.001). Conclusions Structured observation of effective teamwork in the operating room can identify substantive deficiencies in the system and conduct of procedures, even in otherwise successful operations. High performing teams are more resilient displaying effective teamwork when operations become more difficult.

Assessing and improving teamwork in cardiac surgery

Objective Cardiac surgery (PCS) has a low error tolerance, is dependent upon sophisticated organisational structures and demands high levels of cognitive and technical performance. The aim of the study was to assess the role of intraoperative non-routine events (NREs) and team performance on paediatric cardiac surgery outcomes. The current paper focuses on improving methods for studying teamwork; a companion paper will report on the empirical results. Methods The authors trained human factors observers to observe and code the NREs and teamwork from time of arrival of the patient into the operating room (OR) to the patient handover in the intensive care unit. The observers underwent immersive training in which each observer attended 10 operations, learnt in detail about the technical procedures and clinical tasks and received practice in coding teamwork. Two observers were used interchangeably to observe OR teamwork. The authors instigated a rigorous training and assessment protocol, with independent assessment of their performance by both senior medical and human factors experts using video-based assessment. Real-time teamwork observations were supplemented with process mapping, questionnaires on safety culture, level of preparedness by the team, difficulty of the operation and outcome measures. Results 19 PCS cases were observed. The observers observed a total of 255 hr of operations, including the first 10 training cases. We found that 68% of events were observed by one observer but only 32% of all events were observed by both observers. If an event was coded by both observers, 76% was coded in the same way, resulting in high levels of inter-rater agreement. The inter rater reliability of the four main teamwork categories was 91% with Cohen kappa of 0.77. Recommendations were developed for observing teamwork in the operating room, for instance ‘train observers on video recordings of real operations (not scripted performance), preferably of at least 1–2 h in duration’ and ‘Rate teamwork in real time and not afterwards.’ Conclusions PCS is an ideal model to explore team performance. A challenge for the future is to make observations of teamwork in healthcare settings more efficient and robust.

Results of staged total cavopulmonary connection for functionally univentricular hearts; comparison of intra-atrial lateral tunnel and extracardiac conduit

OBJECTIVES This study aims to compare the outcome of the two co-existing modifications of staged total cavopulmonary connection (TCPC) - the intra-atrial lateral tunnel (ILT) and the extracardiac conduit (ECC). METHODS We included 209 patients after staged TCPC (102 ILT and 107 ECC), operated on between 1988 and 2008. Medical and surgical records were reviewed for (1) patient demographics and cardiac anatomy; (2) pre-Fontan procedures; (3) pre-Fontan haemodynamics and cardiac functional status; (4) operative details; (5) postoperative hospital course; (6) follow-up information on arrhythmias and thrombo-embolic events; (7) post-Fontan interventions; and (8) clinical status at last follow-up until June 2008. RESULTS Median follow-up duration was 4.3 years (interquartile range 1.5-7.4 years). At 6-year follow-up, freedom from Fontan failure (i.e., mortality or re-operations for Fontan failure) was 83% for the ILT and 79% for the ECC groups (p=0.6); freedom from late re-operations (other than re-operations for Fontan failure) was 79% for the ILT and the ECC groups and freedom from arrhythmias was 83% for the ILT, and 92% for the ECC groups (p=0.022). Multivariable Cox regression analysis identified intensive care unit stay and cardiopulmonary bypass time as risk factors for Fontan failure, but they were not strong predictors. Right ventricular morphology was identified as a risk factor for arrhythmias. The occurrence of thrombo-embolic events was low with no difference between the ILT and the ECC groups, and irrespective of the postoperative use of anticoagulant or anti-platelet aggregation therapy. At most recent follow-up, sinus rhythm was present in 70% of patients; in 23% of the patients, ventricular function was found to be moderately or severely impaired at echocardiography. CONCLUSIONS Outcome after staged ILT- and ECC-type Fontan operations is good, with comparable freedom from late re-operations and freedom from Fontan failure at 6-year follow-up. The incidence of arrhythmias was significantly lower in the ECC group. Right ventricular morphology was identified as a risk factor for arrhythmias.

Neurological Injury After Neonatal Cardiac Surgery A Randomized, Controlled Trial of 2 Perfusion Techniques

Background— Complex neonatal cardiac surgery is associated with cerebral injury. In particular, aortic arch repair, requiring either deep hypothermic circulatory arrest (DHCA) or antegrade cerebral perfusion (ACP), entails a high risk of perioperative injury. It is unknown whether ACP results in less cerebral injury than DHCA. Methods and Results— Thirty-seven neonates with an aortic arch obstruction presenting for univentricular or biventricular repair were randomized to either DHCA or ACP. Preoperatively and 1 week after surgery, magnetic resonance imaging was performed in 36 patients (1 patient died during the hospital stay). The presence of new postoperative cerebral injury was scored, and results were entered into a sequential analysis, which allows for immediate data analysis. After the 36th patient, it was clear that there was no difference between DHCA and ACP in terms of new cerebral injury. Preoperatively, 50% of patients had evidence of cerebral injury. Postoperatively, 14 of 18 DHCA patients (78%) had new injury versus 13 of 18 ACP patients (72%) (P=0.66). White matter injury was the most common type of injury in both groups, but central infarctions occurred exclusively after ACP (0 vs 6/18 [33%]; P=0.02). Early motor and cognitive outcomes at 24 months were assessed and were similar between groups (P=0.28 and P=0.25, respectively). Additional analysis revealed lower postoperative arterial PCO2 as a risk factor for new white matter injury (P=0.04). Conclusions— In this group of neonates undergoing complex cardiac surgery, we were unable to demonstrate a difference in the incidence of perioperative cerebral injury after ACP compared with DHCA. Both techniques resulted in a high incidence of new white matter injury, with central infarctions occurring exclusively after ACP. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT01032876.Background— Complex neonatal cardiac surgery is associated with cerebral injury. In particular, aortic arch repair, requiring either deep hypothermic circulatory arrest (DHCA) or antegrade cerebral perfusion (ACP), entails a high risk of perioperative injury. It is unknown whether ACP results in less cerebral injury than DHCA. Methods and Results— Thirty-seven neonates with an aortic arch obstruction presenting for univentricular or biventricular repair were randomized to either DHCA or ACP. Preoperatively and 1 week after surgery, magnetic resonance imaging was performed in 36 patients (1 patient died during the hospital stay). The presence of new postoperative cerebral injury was scored, and results were entered into a sequential analysis, which allows for immediate data analysis. After the 36th patient, it was clear that there was no difference between DHCA and ACP in terms of new cerebral injury. Preoperatively, 50% of patients had evidence of cerebral injury. Postoperatively, 14 of 18 DHCA patients (78%) had new injury versus 13 of 18 ACP patients (72%) ( P =0.66). White matter injury was the most common type of injury in both groups, but central infarctions occurred exclusively after ACP (0 vs 6/18 [33%]; P =0.02). Early motor and cognitive outcomes at 24 months were assessed and were similar between groups ( P =0.28 and P =0.25, respectively). Additional analysis revealed lower postoperative arterial Pco2 as a risk factor for new white matter injury ( P =0.04). Conclusions— In this group of neonates undergoing complex cardiac surgery, we were unable to demonstrate a difference in the incidence of perioperative cerebral injury after ACP compared with DHCA. Both techniques resulted in a high incidence of new white matter injury, with central infarctions occurring exclusively after ACP. Clinical Trial Registration— URL: . Unique identifier: [NCT01032876][1]. # CLINICAL PERSPECTIVE {#article-title-31} [1]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT01032876&atom=%2Fcirculationaha%2F129%2F2%2F224.atom

Long-term restoration of the human T-cell compartment after thymectomy during infancy: a role for thymic regeneration?

Thymectomy during early childhood is generally thought to have serious consequences for the establishment of the T-cell compartment. In the present study, we investigated the composition of the T-cell pool in the first 3 decades after thymectomy during infancy due to cardiac surgery. In the first 5 years after thymectomy, naive and total CD4(+) and CD8(+) T-cell numbers in the blood and T-cell receptor excision circle (TREC) levels in CD4(+) T cells were significantly lower than in healthy age-matched controls. In the first years after thymectomy, plasma IL-7 levels were significantly elevated and peripheral T-cell proliferation levels were increased by ∼ 2-fold. From 5 years after thymectomy onward, naive CD4(+) and CD8(+) T-cell counts and TRECs were within the normal range. Because TREC levels are expected to decline continuously in the absence of thymic output, we investigated whether normalization of the naive T-cell pool could be due to regeneration of thymic tissue. In the majority of individuals who had been thymectomized during infancy, thymic tissue could indeed be identified on magnetic resonance imaging scans. Whereas thymectomy has severe effects on the establishment of the naive T-cell compartment during early childhood, our data suggest that functional regrowth of thymic tissue can limit its effects in subsequent years.

Increasing duration of circulatory arrest, but not antegrade cerebral perfusion, prolongs postoperative recovery after neonatal cardiac surgery.

OBJECTIVE Deep hypothermic circulatory arrest (DHCA) and antegrade cerebral perfusion (ACP) are 2 cardiopulmonary bypass techniques applied in aortic arch repair. In recent literature, cerebral effects of both techniques have received most attention, whereas the consequences for other organs have not been thoroughly investigated. Therefore, in this study, the impact of duration of DHCA and ACP on postoperative recovery was analyzed in a cohort of neonates undergoing aortic arch reconstruction. METHODS All consecutive neonates who underwent aortic arch reconstruction from 2004 to 2009 were included in this retrospective study. Length of stay on the intensive care unit (ICU-LOS), duration of mechanical ventilation, inotrope score, and areas under the curve (AUC) for lactate and creatinine were compared with respect to durations of DHCA and ACP, respectively. Correction for confounders was performed using multivariable linear regression. RESULTS Eighty-three neonates were included, with a 30-day mortality of 4.8%. Longer duration of DHCA was associated with longer ICU-LOS both in univariable and multivariable analyses. Similarly, duration of mechanical ventilation and lactate and creatinine AUCs increased with duration of DHCA. Inotrope score was only associated with DHCA duration in univariable analysis. Duration of ACP did not affect any of the outcome parameters. CONCLUSIONS Increasing duration of DHCA, but not ACP, during neonatal aortic arch reconstruction prolongs short-term postoperative recovery. This suggests all efforts should be made to reduce the duration of DHCA to the shortest period possible, which may be achieved by exclusive use of ACP or a combination of the 2 perfusion techniques.

Comparability of Z-score equations of cardiac structures in hypoplastic left heart complex.

BACKGROUND Hypoplastic left heart complex (HLHC) is characterized by a mitral valve or an aortic valve annular Z score < -2, antegrade flow in the ascending aorta, ductal dependency, coarctation or aortic arch hypoplasia, and absence of significant (sub)valvar stenosis. The Z scores of the mitral and aortic valve annuli are major determinants of HLHC. Therefore, the algorithm for Z-score calculation is essential for diagnosis. However, no single universal method of calculation is in use. In the scientific literature addressing HLHC, various Z-score calculation methods have been applied. The aim of this study was to evaluate Z scores derived from two-dimensional echocardiographic dimensions in patients with HLHC. METHODS To compare the different published methods using two-dimensional echocardiographic measures for Z-score calculation, a cohort of 18 newborns diagnosed with HLHC was retrospectively evaluated. In addition, the methods to determine body surface area in newborns were evaluated. RESULTS Three Z-score calculation methods were included and compared. Using the method of Daubeney et al. to calculate Z scores in our cohort illustrated a lack of correlation beyond a Z score < 0, compared with the methods of Zilberman et al. and Pettersen et al. Z scores calculated using Zilberman et al.s and Pettersen et al.s methods were fairly consistent. The equations used by Pettersen et al. are based on the largest population of neonates. CONCLUSION Although the different methods for calculating Z scores for mitral and aortic valve dimensions correspond fairly well in the normal range, Z scores < -2 diverge substantially. A useful scientific comparison of published data and outcomes of patients with HLHC remains elusive. The Z-score calculation algorithms used by Pettersen et al. appear to be the most appropriate for use in an evaluation of HLHC. Because these different methods can yield different values, reporting the method as well as the Z score is essential for an accurate diagnosis. Similarly, the method used to determine body surface area should be reported.

Aortoesophageal fistula due to double aortic arch and prolonged nasogastric intubation: case report and review of the literature

BackgroundThe authors present a patient and describe other cases from the literature which demonstrate that prolonged use of nasogastric tubes can result in life-threatening aortoesophageal fistula formation in patients with a double aortic arch.ConclusionAortoesophageal fistula (AEF) is an abnormal communication between the esophagus and the aorta. It can cause massive gastrointestinal hemorrhage. We present an infant with an operatively corrected double aortic arch, who developed this complication after prolonged nasogastric intubation.