Thierry Bové

Early results of valved bovine jugular vein conduit versus bicuspid homograft for right ventricular outflow tract reconstruction

BACKGROUND Homograft conduits are preferable for right ventricular outflow tract reconstruction in children, but their limited availability remains a major concern. Recently, a valve-containing segment of bovine jugular vein (Contegra, Medtronic Inc, Minneapolis, MN) has been introduced as a potential alternative conduit. METHODS Early clinical and echocardiographic results of right ventricular outflow tract reconstruction were retrospectively compared between 41 children (mean age, 1.9 years), receiving a Contegra conduit and 36 patients (mean age, 2.7 years) with a size-reduced pulmonary homograft. RESULTS Clinical outcome was comparable with two early deaths in the homograft group and one in the Contegra group. There were no conduit-related complications in either population. Early echocardiographic assessment showed only trivial to mild regurgitation in 9 homografts versus 17 Contegra conduits. The peak gradient across the right ventricular outflow tract conduit was comparable for both groups, although a larger number of patients, treated with a downsized homograft, had a small gradient at the distal junction with the pulmonary arteries (12 versus 6 patients). None of the patients had a gradient at the valvar level. CONCLUSIONS The valved bovine jugular vein conduit offers a promising substitute for right ventricular outflow tract reconstruction in infants and children, with an early hemodynamic performance that compares favorably with downsized, bicuspid homografts. Clinical advantages are greater shelf availability and the natural continuity between valve and conduit, which allows proximal infundibular shaping without additional material. However, durability must be determined, even though most of these children will require right ventricular outflow tract reoperation after outgrowing the conduit.

Relation between mixed venous oxygen saturation and cerebral oxygen saturation measured by absolute and relative near-infrared spectroscopy during off-pump coronary artery bypass grafting

BACKGROUND We hypothesized that previously reported contradictory results regarding the equivalence of mixed venous (Smv(O(2))) and cerebral (rS(c)O(2)) oxygen saturation might be related to time delay issues and to measurement technology. In order to explore these two factors, we designed a prospective clinical study comparing with relative (INVOS(®)) and absolute (Foresight(®)) rS(c)O(2) measurements. METHODS Forty-two consenting patients undergoing elective off-pump coronary artery bypass grafting were included. Two INVOS and two Foresight sensors continuously registered rS(c)O(2). Smv(O(2)) was measured continuously via a pulmonary artery catheter. Data were assessed by within- and between-group comparisons and correlation analysis. RESULTS A similar time delay of 19 (4) and 18 (4) s was found for compared with rS(c)O(2) measurements by Foresight and INVOS, respectively, during haemodynamic changes. After adjusting for this time delay, the correlation between Smv(O(2)) and rS(c)O(2) increased from r=0.25 to 0.75 (P<0.001) for Foresight, and from r=0.28 to 0.73 (P<0.001) for INVOS. Comparison of Foresight and INVOS revealed significant differences in absolute rS(c)O(2) values (range 58-89% for Foresight and 28-95% for INVOS). Changes in rS(c)O(2) in response to acute haemodynamic alterations were significantly more pronounced with INVOS compared with Foresight (P<0.001). CONCLUSIONS Considering the important time delay with Smv(O(2)), rS(c)O(2) seems to reflect more appropriately acute haemodynamic alterations. This might suggest its use as a valid alternative to invasive monitoring of tissue oxygen saturation. Relative and absolute rS(c)O(2) measurements demonstrated significant differences in measured rS(c)O(2) values and in the magnitude of rS(c)O(2) changes during haemodynamic alterations.

Assessment of a right-ventricular infundibulum-sparing approach in transatrial-transpulmonary repair of tetralogy of Fallot.

OBJECTIVE The study aimed to evaluate the outcome of transatrial-transpulmonary repair of tetralogy of Fallot in relation to a right-ventricular outflow tract (RVOT)-sparing surgery. METHODS Based on the surgical management of right-ventricular outflow tract obstruction (RVOTO) at repair of tetralogy of Fallot, 140 children were retrospectively divided into three groups: (1) pulmonary valve (PV)-sparing, (2) infundibulum-sparing and (3) extended trans-annular patch (TAP). Clinical and echocardiographic outcome was assessed with regards to three equally divided study time eras between January 1994 and June 2010. RESULTS Over a 15-year study period, median age decreased from 11 (2-101) to 5 (1-11) months (p<0.001), whereas type of RVOT repair changed significantly between the first and the last era (group 1: 18-40%, group 2: 25-40% vs group 3: 57-20% (p=0.002)). Mortality was 0%. Complications were mainly related to clinical restrictive RV physiology (27%) and arrhythmia (10%). This cardiac morbidity remained constant over the eras and was associated with younger age (p=0.04), increased postoperative right ventricle/left ventricle (RV/LV) pressure ratio (p=0.01) and type of RVOT repair at the cost of TAP (p=0.03). Median follow-up of 8 years (1-16 years) showed an overall freedom from RVOT re-operation of 84% and 73%, respectively at 5 and 10 years. Most re-operations were for residual/recurrent RVOTO (12%) occurring more frequently in the latter era: 16% versus 7% in era 1 (p=0.08). Late echocardiographic evaluation revealed a strong correlation between severity of pulmonary regurgitation and increased RV/LV size ratio, which was mainly determined by increased TAP length (p<0.001) and duration of follow-up (p=0.06). CONCLUSION In a 15-years experience with transatrial-transpulmonary correction of tetralogy of Fallot, a valve- and infundibulum-sparing approach has been advanced by lowering the age for elective repair. This change has been performed without compromising immediate clinical outcome, despite an increased early re-operation rate for residual obstruction. However, longer follow-up will disclose whether this approach is protective against progressive and late RV dysfunction.

Operative outcome of minimal access aortic valve replacement versus standard procedure.

Abstract Background: to determine the advantages and/or risks of minimal access aortic valve replacement compared to standard sternotomy procedure. Methods: from January 1997 to December 2001, 271 consecutive adult patients underwent isolated aortic valve replacement of which 174 underwent a minimal access procedure (Group 1) and 97 a standard procedure (Group 2).The preoperative variables of both groups were comparable. Retrospective analysis of postoperative outcome was performed. Results: follow-up was complete and ranged from 6 months to 4 years. Overall in-hospital mortality was 3.3% (respectively 2.8 and 4.1%). No statistical difference was noted regarding operative time variables, mortality rate and hospital stay. There was a significant higher incidence of revision (p = 0.018) and late pericardial effusion (p = 0.022) in the minimal access group. Also trends were in favour of the standard group for incidence of postoperative pneumothorax and pericarditis constrictiva. Conclusions: minimal access aortic valve replacement is a safe and reliable technique, but carries the risk of incision-related morbidity. Proper patient selection and perioperative management is mandatory.

The effect of retrograde autologous priming volume on haemodilution and transfusion requirements during cardiac surgery

OBJECTIVES Many cardiac procedures using cardiopulmonary bypass (CPB) still require intraoperative transfusion. Retrograde autologous priming (RAP) has been introduced to decrease haemodilution and the blood transfusion rate. This study is designed to determine the influence or RAP on intraoperative haematocrit, transfusion and its clinical consequences. METHODS The RAP effect was retrospectively studied in 753 patients during contemporary cardiac surgery, targeting a haematocrit of 25%. Multivariate linear regression analysis was performed to identify the independent factors influencing intraoperative haematocrit, transfusion rate and transfusion quantity. RESULTS RAP was used in 498 patients and compared with 255 controls. RAP decreased the haemodilution level (nadir haematocrit 26.8 standard deviation [SD] 4.0% in RAP vs 25.8 SD 3.6% in controls; P = 0.001) and transfusion frequency (26.1 vs 33.3%, P = 0.04), despite smaller patients (body surface area [BSA] 1.86 SD 0.20 m(2) vs 1.91 SD 0.21 m(2) in RAP vs controls; P = 0.002) with lower preoperative haematocrit (38.9 SD 4.4% vs 40.5 SD 4.6%; P < 0.001). Optimal RAP volume was overall 475 ml (ROC area 0.55; 95% confidence interval [CI] 0.50-0.60; P = 0.04) and 375 ml in patients with BSA <1.7 m(2) (ROC area 0.63; 95% CI 0.54-0.73; P = 0.008) to decrease the transfusion incidence. Multivariate analysis revealed RAP volume as a significant determinant of nadir haematocrit (β = 0.003, 95% CI 0.002-0.004, P < 0.001) and transfusion rate (odds ratio (OR) = 0.997, 95% CI 0.996-0.999, P < 0.001), independent of BSA, gender and preoperative haematocrit. CONCLUSIONS Retrograde autologous priming is an effective adjunct to decrease the blood transfusion rate, coping with the CPB-related haemodilution and its adverse clinical effects. A RAP volume individualized to each patient offers most benefit as part of a multidisciplinary blood conservation approach.

Pleural effusions, water balance mediators and the influence of lisinopril after completion Fontan procedures

OBJECTIVE To investigate whether the duration of pleural drainage after Fontan completion operations can be influenced by postoperative lisinopril administration or can be related to water balance hormone levels. METHODS In a prospective trial 21 patients scheduled for total cavopulmonary connection were randomized into two groups, with group I receiving lisinopril postoperatively, and group II receiving no angiotensin converting enzyme inhibitor. Plasma levels of antidiuretic hormone, renin and aldosteron were analyzed preoperatively and at four-time points postoperatively. Groups were comparable for age, preoperative saturation and pulmonary pressure, cardiopulmonary bypass time, cross-clamp time and preoperative hormone levels. RESULTS Mean duration of pleural drainage was comparable for both groups (group I: 9.6+/-8 days vs group II: 10+/-7 days; p=0.78). The hormone profiles in each group changed significantly at 1 and 24h postoperatively compared to preoperative values (p<0.05), with no significant differences between the treatment groups. The duration of pleural drainage correlated significantly with hormone levels at 24h postoperatively, and with longer bypass times. At multivariate analysis only aldosteron and antidiuretic hormone level at 24h came out as factors reaching significance for prolonged pleural drainage. CONCLUSIONS The Fontan completion induces significant changes in the levels of antidiuretic hormone, aldosteron and renin. Prolonged drainage correlates significantly with elevated levels of aldosteron, renin and antidiuretic hormone postoperatively, and with longer bypass time, but is not influenced by lisinopril. The eventual adjunct therapy with aldosteron antagonists warrants further study.

Acute and chronic effects of dysfunction of right ventricular outflow tract components on right ventricular performance in a porcine model: implications for primary repair of tetralogy of fallot

OBJECTIVES This study investigates the contribution of infundibular versus pulmonary valve (PV) dysfunction on right ventricular (RV) function in a porcine model. BACKGROUND Clinical outcome after repair of tetralogy of Fallot is determined by the adaptation of the right ventricle to the physiological sequelae of the right ventricular outflow tract (RVOT) reconstruction. Recent surgical techniques are pursuing a PV-versus infundibulum-sparing approach. METHODS In a porcine model, 3 types of RVOT dysfunction were created and compared with sham-operated controls: infundibular dysfunction (INF), PV insufficiency (PI), and combined infundibular-PV dysfunction (TAP). Both acute and chronic effects on RV function were studied by using conductance technology and magnetic resonance imaging. RESULTS In animals with PI, pulmonary regurgitant fraction progressed more in the presence of concomitant INF (54% in TAP versus 14% in PI; p = 0.03). Subsequently, RV end-systolic and end-diastolic volume increased more in both groups, resulting in decreased ejection fraction after 3 months. Preload-independent systolic indices showed acute impairment of RV contractility in all treatment groups but most in animals with infundibular scarring (INF and TAP). Further chronic deterioration was observed in animals of the TAP group. RV compliance improved proportionally most in the PI and TAP groups in relation to the extent of RV dilation. CONCLUSIONS Surgical RVOT dysfunction, whether it includes the infundibulum and/or the PV, has an immediate effect on RV performance. Although impaired RV contractility is due to intrinsic myocardial damage by infundibular distortion, it is chronically furthered by PI-related RV dilation. These findings support the adoption of a RVOT-sparing strategy to treat tetralogy of Fallot.

Disease-specific outcome analysis of palliation with the modified Blalock-Taussig shunt.

Background: Albeit being a simple surgical procedure, adverse outcomes with the modified Blalock-Taussig shunt (MBTS) are commonly reported in generalizing terms, independent of the underlying heart disorder. Methods: From August 1995 to December 2013, a total of 150 children underwent an MBTS for tetralogy of Fallot (TOF; n = 44, 29%), pulmonary atresia with ventricular septal defect (PA/VSD; n = 28, 19%), pulmonary atresia with intact ventricular septum (PA/IVS; n = 17, 11%), transposition of the great arteries with ventricular septal defect (TGA/VSD) with pulmonary stenosis (PS; n = 12, 8%), Ebstein malformation (n = 2, 1%), and complex univentricular anomalies (n = 47, 31%). Outcome analysis focused on operative mortality and survival until shunt takedown, adjusted to the underlying disease. Results: In-hospital mortality was 8.7% (n = 13), and interstage mortality was 5.1% (n = 7), resulting in 86.1% survival to the next surgery. Hospital mortality was 14% in PA/VSD, 13% in univentricular heart, and 18% in PA/IVS, while no mortality was observed in TOF, TGA/VSD/PS, and Ebstein disease. A shunt-related complication was observed in 18% (n = 27) of the children, including acute thrombosis (n = 7, 5%), shunt stenosis (n = 3, 2%), overshunting (n = 7, 5%), and pulmonary artery stenosis (n = 10, 7%). Multivariate analysis of shunt-dependent time survival identified a shunt complication occurring in a univentricular circulation (hazard ratio [HR] 4.10, 95% confidence interval [CI] = 1.05-17.43, P = .01) and increased shunt size-to-weight ratio (HR 2.72, 95% CI = 0.80-9.18, P = .04) as risk factors. Shunt thrombosis was also a negative outcome predictor in PA/VSD, when requiring associated unifocalization (P = .05). Conclusion: This study shows that the outcome of palliation with the MBTS is importantly affected by the occurrence of a shunt-related complication, whose circulatory effect is even more dismal in single ventricle hearts. Since an increased shunt size-to-weight ratio additionally compromises the shunt-dependent survival, it emphasizes that the choice of the shunt with regard to size as well as surgical approach remains critical.

Univentricular heart and Fontan staging: analysis of factors impacting on body growth

OBJECTIVES The optimal timing of the Fontan staging for a univentricular heart and its impact on growth remains debateable. In a Fontan cohort, the influence of staged interventions and patient factors on somatic development was explored. METHODS We reviewed 64 total cavopulmonary connection (TCPC) patients treated since 1992. Serial anthropometric parameters recorded from birth to the latest follow-up (mean 12.5 ± 6.1 years) and at each intervention [neonatal surgery, bidirectional cavopulmonary anastomosis (BCPA), TCPC, catheter treatment] were converted to z-scores. The influence of saturation, heart failure treatment and surgery intervals on growth was determined. RESULTS The mean z-scores for weight and height changed significantly at each surgery up to the TCPC (-0.3 ± 1.2 and 0 ± 1 at birth, -1.3 ± 1.9 and -0.9 ± 1.7 at neonatal surgery, -2.1 ± 1.2 and -1.6 ± 1.3 at the BCPA, -1.2 ± 1.3 and -0.7 ± 1.4 at the TCPC for weight and height, respectively; P < 0.05 for each interval), with the largest decline before the BCPA, and the most marked improvement before the TCPC. Z-scores did not change significantly after the TCPC. Younger age at the BCPA had a positive influence on the weight z-score at the TCPC (P < 0.05); somatic growth at the latest follow-up (FU) was negatively influenced by heart failure treatment (P < 0.05). CONCLUSIONS Body growth is severely impaired in Fontan patients. A close interstage follow-up between the first surgery and the BCPA must be targeted at optimizing nutritional support to counter the important growth retardation occurring before the BCPA. The better catch-up growth at the TCPC when the BCPA is performed earlier in life supports the current trend to perform the BCPA at a younger age. Heart failure treatment after a Fontan completion is independently associated with decreased late somatic development.

Short-term systolic and diastolic ventricular performance after surgical ventricular restoration for dilated ischemic cardiomyopathy.

OBJECTIVE Based on the adverse relationship between left ventricular (LV) remodeling and clinical outcome in ischemic cardiomyopathy, surgical ventricular restoration (SVR) is proposed as a valuable adjunct procedure. This study reports on the short-term clinical and hemodynamical performance of SVR. METHODS Using end-systolic LV volume as indication for SVR, 78 patients with ischemic cardiomyopathy are divided in two groups: group 1 comprised 55 patients treated by coronary revascularization and mitral annuloplasty, group 2 comprised 23 patients undergoing additional SVR. Hemodynamic investigation included echocardiographic assessment of systolic and diastolic function. Clinical follow-up focused on survival and functional status with exercise performance. RESULTS Both surgical approaches resulted in improvement of NYHA class (2.9-1.6 in group 1; 3.3-1.5 in group 2, p<0.001), achieving similar exercise performance (peak VO2 13.7 vs 15.4 ml/kgmin in groups 1 and 2, p=0.25) and plasma BNP values (group 1: 1350 pg/ml and group 2: 767 pg/ml, p=0.23). SVR provided additional benefit as patients basically had a worse NYHA class (2.9 in group 1 vs 3.3 in group 2, p=0.03). Within mean follow-up of 20 months, survival rate was 84% in group 1 and 74% in group 2 (p=0.11), including operative mortality of 7% and 13% (p=0.42). Through effective volume reduction (LVEDVI 41%; LVESVI 49%) systolic function improved immediately after SVR (LVEF 27-39% in group 2, p<0.05). Worsening of diastolic function was specifically observed after SVR within the first year (E/A-ratio 1.38-1.74 cm/s, p=0.02). Recurrent mitral regurgitation (p=0.004) and secondary remodeling (p=0.01) were major determinants of decreasing LV compliance. Clinical outcome in terms of cardiac events and survival was compromised by restrictive diastolic function (p=0.02) and increased LV volumes (p=0.04). CONCLUSION SVR in addition to coronary revascularization and restrictive mitral annuloplasty results in significant clinical improvement in selected patients with advanced ischemic heart disease and severely dilated ventricles. SVR entails immediate improvement of systolic function, which remains sustained during short-term follow-up. Serial assessment of diastolic function is mandatory as LV compliance seems more sensitive to early changes induced by recurrence of mitral regurgitation and secondary ventricular dilation. Moreover, worsening of diastolic dysfunction should be timely recognized because of its adverse clinical impact.