Bahaaldin Alsoufi

Extra-corporeal life support following cardiac surgery in children: analysis of risk factors and survival in a single institution.

OBJECTIVEnApplication of extra-corporeal life support (ECLS) following pediatric cardiac surgery varies between different institutions based on manpower availability and philosophy towards ECLS utilization. We examined a large single institution experience with postoperative ECLS in children aiming to identify outcome predictors.nnnMETHODSnHospital records of all children who required postoperative ECLS at our institution were reviewed. Patients demographics, cardiac anatomy, surgical and ECLS support details were entered into a multivariable regression analysis to determine factors associated with survival.nnnRESULTSnBetween 1990 and 2007, 180 consecutive children, median age 109 days (range: 1 day-16.9 years), required postoperative ECLS. Sixty-nine children (38%) had undergone palliative treatment for single ventricle pathology. ECLS support was required for failure to separate from cardiopulmonary bypass (n=83) or for postoperative low cardiac output state (n=97). Forty-eight patients (27%) received rescue extra-corporeal membrane oxygenation (ECMO) support during active chest compression for refractory cardiac arrest. Under ECLS support, 37 patients required surgical revision and 20 received orthotopic heart transplantation. One hundred and nine patients (61%) survived >24h following ECLS discontinuation and 68 (38%) were discharged alive. Hospital survivors required shorter ECLS support duration compared to non-survivors (median 3 vs 5 days, respectively, p=0.05) however survival occurred after up to 16 days of ECLS support. ECLS indication (OR: 0.85 for failure to separate from bypass vs postoperative low cardiac output 95% CI (0.47-1.56), p=0.62) and rescue ECMO (OR: 0.63 for rescue ECMO vs not 95%CI (0.32-1.24), p=0.18) were not associated with risk of mortality. In a multivariable logistic regression model, neurological complications (p=0.0007), prolonged ECLS duration (p=0.003), repeat ECLS requirement (p=0.02), renal dysfunction (p=0.04) and not performing heart transplantation (p=0.04) were significant factors for hospital death.nnnCONCLUSIONnECLS plays a valuable role in children with low cardiac output state following cardiac surgery. More than one third of those patients, including young neonates, older children, patients with single ventricle, or those requiring rescue ECMO can be salvaged. Although prognosis worsens with prolonged ECLS duration, survival can be noted up to 16 days of support. Heart transplantation is often an important ECLS exit strategy and should be considered early in selected children. Patients survival could improve if renal and neurological complications are avoided.

Mechanical valves versus the Ross procedure for aortic valve replacement in children: propensity-adjusted comparison of long-term outcomes.

OBJECTIVEnWe aimed to identify characteristics differentiating children undergoing aortic valve replacement by using mechanical prostheses versus the Ross procedure and to compare survival and the need for aortic valve reoperation after each procedure.nnnMETHODSnFrom 1983 to 2004, 346 children underwent aortic valve replacement (215 underwent the Ross procedure and 131 underwent placement of a mechanical prosthesis). Factors associated with procedure choice were used to construct a propensity score for use as a covariate in regression models to adjust for potential confounding by indication.nnnRESULTSnPatients undergoing the Ross procedure were younger, more likely to have a congenital cause, and less likely to have a rheumatic or connective tissue cause. They had a lower frequency of regurgitation, required more annular enlargement, and had less concomitant cardiac surgery. Competing-risk analysis showed that 16 years after aortic valve replacement, 20% of patients had died without subsequent aortic valve replacement, 25% underwent second aortic valve replacement, and 55% remained alive without further replacement. After propensity adjustment, factors associated with early-phase death included mechanical valves and a nonrheumatic cause. Mechanical valves were also associated with constant-phase mortality. Repeated aortic valve replacement was associated with the Ross procedure and a rheumatic cause. Both factors were also associated with all-cause cardiac reoperation. In children receiving mechanical prostheses, younger age and smaller valve size were significant risk factors for death. Freedom from homograft replacement after the Ross procedure was 82% at 16 years of follow-up.nnnCONCLUSIONnResults from this study showed good outcomes and an acceptable complication rate with both valve choices. Given the significantly increased risk of early and late death in younger children receiving smaller mechanical valves, the Ross procedure confers survival advantage in this age group at the expense of increased reoperation risk, especially in patients with a rheumatic cause.

Aortic and mitral valve replacement in children: is there any role for biologic and bioprosthetic substitutes?

OBJECTIVEnThe ideal valve substitute in children does not exist. Biologic and bioprosthetic valves do not require anticoagulation, however their use is complicated by accelerated degeneration and requirement for reoperation. We examine results following mitral (MVR) or aortic (AVR) replacement with biologic and bioprosthetic valves at our institution.nnnMETHODSnMedical records of children who underwent AVR or MVR from 1986 to 2006 were reviewed. Median follow-up duration was 10.5 years. Competing-risks methodology determined time-related prevalence and associated factors for three mutually exclusive end states: death, valve reoperation, and survival without subsequent reoperation.nnnRESULTSnOne hundred and ten children (age 15.6+/-2.6 years, 80% females) underwent 123 valve replacements with biologic and bioprosthetic substitutes including 87 MVR and 36 AVR (13 had both). Underlying pathology was mainly rheumatic fever (91%). Thirty-nine patients (35%) had undergone a previous cardiac surgery. Most common mitral substitute was Hancock (73%) and homograft (8%); most common aortic substitute was homograft (41%) and Carpentier-Edwards (39%). Competing-risks analysis showed that 15 years after valve replacement, 16% of patients had died without subsequent reoperation, 66% underwent valve reoperations, and only 18% remained alive without further reoperation. Factors associated with increased reoperation risk included younger age at surgery (p=0.005), AVR (p=0.005), male gender (p=0.02) and homograft use (p=0.007) especially in the mitral position (p=0.002). Fifteen-year freedom from endocarditis was 97% while freedom from bleeding and thrombo-embolic complications was 100%. Majority of patients (95%) were in NYHA functional classes I/II at last follow-up.nnnCONCLUSIONnWhile valve reoperation is inevitable following AVR and MVR with biologic and bioprosthetic substitutes; favorable results such as low valve-related morbidity rate, good long-term survival and functional status encourage their consideration as valid replacement alternatives in selected children especially females. Valve durability is higher in the mitral position and longevity of bioprosthetic valves is greater than that of homografts especially in the mitral position.

Current outcomes of the Glenn bidirectional cavopulmonary connection for single ventricle palliation

OBJECTIVESnThe Glenn bidirectional cavopulmonary connection (BCPC) is an established procedure in multistage palliation of various single ventricle (SV) anomalies. We aimed to report the current outcomes following BCPC and to examine risk factors affecting survival and progression to the next palliation stage.nnnMETHODSnTwo hundred and twenty-seven consecutive children with variable SV pathologies underwent BCPC from 2002 to 2007. Competing risk analyses were performed to model events after BCPC (death and transition to Fontan) and subsequently after Fontan (death and cardiac reoperation) and to examine the associated risk factors for poor outcomes.nnnRESULTSnThere were 139 males (61%) with a median age of 7.6 months [interquartile range (IQR) 6.0-10.8] and median weight of 6.2 kg (IQR 5.2-7.4). Forty-three patients (19%) had primary BCPC and 184 (81%) had prior palliation: aortopulmonary shunt (APS) (n=83), Norwood (n=55), pulmonary artery (PA) band (n=48), atrial septectomy (n=25), PA reconstruction (n=14), anomalous pulmonary venous connection repair (n=7) and other (n=8). Predominant ventricle was left morphology (n=122, 54%), right morphology (n=95, 42%) and two equally developed ventricles (n=10, 4%). Twenty-six patients (12%) had bilateral superior vena cava. Concomitant surgery included atrioventricular valve repair (n=18), PA augmentation (n=80), percutaneous Fontan preparation (n=34) and other (n=24). Competing risk analysis showed that 5 years following BCPC, ∼17% have died, 76% have undergone Fontan and 7% were alive awaiting or not qualifying for Fontan. On multivariable analysis, risk factors for death prior to Fontan were pulmonary vascular resistance (PVR) index of >3 WU/M2 [hazard ratio (HR) 3.9, P=0.001], dominant right ventricle (HR 2.1, P=0.03) and prior palliation other than APS (HR 0.4, P=0.03). Competing risk analysis showed that 3 years following 172 Fontan operations, ∼10% have died, 6% have undergone further cardiac surgery and 84% were alive and free from reoperation. Overall, 8-year survival following BCPC was only 74%.nnnCONCLUSIONSnDespite established selection criteria and improved surgical technique and medical management, there is a continuous failure and attrition risk following BCPC. Outcomes are influenced by underlying cardiac anomaly; patients with dominant left ventricle (i.e. tricuspid atresia, double inlet left ventricle) having the best survival while those with dominant right ventricle (i.e. hypoplastic left heart syndrome, double outlet right ventricle with heterotaxy) having the worst survival. Increased PVR remains a significant factor affecting mortality.

The Ross procedure in children: preoperative haemodynamic manifestation has significant effect on late autograft re-operation.

OBJECTIVESnThe Ross procedure is the aortic valve-replacement procedure of choice in children. Nonetheless, late autograft re-operation for dilatation and/or valve regurgitation is of concern. We examined whether preoperative haemodynamic manifestation (e.g., stenosis, regurgitation and mixed aortic valve disease) affected late re-operation risk.nnnMETHODSnMedical records of 227 children who underwent the Ross procedure (1991-2004) were reviewed. Competing-risks methodology determined time-related prevalence and associated factors for two mutually exclusive end-states after the Ross procedure: (1) death prior to subsequent autograft re-operation and (2) autograft re-operation, with the remainder of patients being alive and free from subsequent autograft re-operation.nnnRESULTSnThere were 162 male patients (71%) in this study. Median age at surgery was 12.1 years (range: 1 week-18 years). The haemodynamic aortic valve dysfunction was primarily stenosis (n=40, 18%), primarily regurgitation (n=109, 48%) and mixed disease (n=78, 35%). Underlying pathology was rheumatic fever (n=104, 46%), congenital heart disease (n=113, 50%) and endocarditis (n=8, 3%). Competing-risks analysis showed that, at 10 years following the Ross procedure, ∼5% of patients had died, 16% had undergone autograft re-operation with aortic valve replacement and 79% were alive and free from autograft re-operation. Ten-year freedom from autograft re-operation for patients with preoperative stenosis, regurgitation and mixed disease was 97%, 69% and 93%, respectively, (p<0.001 for regurgitation vs others). Risk factors for increased risk of autograft re-operation were rheumatic fever (parameter estimates (PEs): 2.09 ± 0.75, p=0.006), and earlier year of surgery (PE: 0.20 ± 0.06, p=0.001). Ten-year freedom from homograft replacement was 81% and was not dependent on haemodynamic manifestation (PE: -0.16 ± 0.38, p=0.68). Significant factors for homograft replacement included fresh homografts (PE: 2.2 ± 0.63, p=0.01) and annular enlargement (PE: 1.11 ± 0.3, p=0.01). Ten-year freedom from cardiac re-operation other than auto-/homograft was 85%, higher in patients with preoperative aortic regurgitation (PE: 1.01 ± 0.42, p=0.02). Concomitant cardiac surgery was a significant factor for late cardiac re-operation other than auto-/homograft replacement (PE: 1.79 ± 0.39, p<0.001).nnnCONCLUSIONSnThe Ross procedure in children is associated with excellent survival. Late autograft re-operation may be required; however, it is more common in children with preoperative aortic regurgitation, especially those with rheumatic fever. Better patient selection in later era has mitigated the risk of autograft re-operation. Continued improved candidate selection, along with modifications in autograft implantation and root/sinotubular stabilisation techniques, may further decrease late autograft failure.

Surgical Strategy to Establish a Dual-Coronary System for the Management of Anomalous Left Coronary Artery Origin From the Pulmonary Artery

BACKGROUNDnOptimal repair of anomalous origin of left coronary artery from pulmonary artery (ALCAPA) relies on the creation of a dual-coronary system. If the anomalous coronary arises at a long distance from the aorta, we use various coronary extension techniques to facilitate tension-free implantation.nnnMETHODSnThirty patients underwent ALCAPA operations using direct coronary transfer (n = 11) or coronary extension techniques (n = 19). Surgical outcomes were analyzed.nnnRESULTSnMedian age and weight were 5.7 months (range, 46 days to 5.45 years) and 5.35 kg (range, 3.3 to 15.9 kg). Five patients had concomitant mitral annuloplasty. Mean cardiopulmonary bypass and ischemic times were 108 +/- 38 and 57 +/- 25 minutes. Two patients required intraoperative revision of the implantation. There were three hospital deaths (10%) and no late deaths. Follow-up echocardiograms demonstrated significant improvement postoperatively vs preoperatively in shortening fraction (35% +/- 2% vs 16% +/- 2%, p < 0.00001), ejection fraction (64% +/- 3% vs 32% +/- 4%, p < 0.00001), and mitral regurgitation (11% moderate vs 70% moderate or severe, p = 0.0002). Left ventricular end-diastolic dimension Z-score decreased from 9.1 +/- 0.9 to 1.2 +/- 0.5 (p < 0.00001). Both techniques were equally effective. Two patients underwent reoperation 1 and 12 years postoperatively (coronary artery bypass grafting, 1; mitral repair with coronary angioplasty, 1). Surviving patients remain asymptomatic (p < 0.00001).nnnCONCLUSIONSnDual-coronary system can be established in patients with ALCAPA. Coronary extension implantation techniques have acceptable operative mortality and excellent cardiac recovery and late survival. Although the rate of late coronary occlusion is low, continual ventricular or mitral dysfunction should trigger evaluation of persistent coronary compromise.

Results after mitral valve replacement with mechanical prostheses in young children

OBJECTIVEnWe examined outcomes after mitral valve replacement in children younger than 8 years.nnnMETHODSnMedical records of patients who underwent mitral valve replacement from 1990 to 2006 were reviewed. Competing-risks methodology determined time-related prevalence and associated factors for death, repeated valve replacement, and survival without reoperation.nnnRESULTSnIn total, 79 patients, median age 24 months (40 days-8 years) underwent 91 mitral valve replacements (10 had repeated procedures). Underlying pathology was congenital heart disease in 95% of cases. Forty-six patients (58%) had undergone previous operations. Operative mortality was 18%, 30% for those 2-years old and younger and 6% for those older than 2 years. Competing-risks analysis showed that 10 years after initial mitral valve replacement, 40% of patients had died without repeated replacement, 20% had undergone a second replacement, and 40% remained alive without further replacement. Factors associated with death included higher prosthesis size/patient weight ratio (P < .0001) and longer crossclamp time (P < .0001). Second replacement 6 +/- 4 years after initial replacement was necessary for 10 survivors. At second replacement, larger prostheses were implanted (mean 24 mm vs 19 mm initially). Repeated MVR was associated with younger age at surgery (p = .006). Permanent pacemaker implantation was eventually needed by 11% of hospital survivors.nnnCONCLUSIONSnMortality and repeated valve replacement are common after mitral valve replacement in children younger than 8 years, especially younger patients with significantly oversized valves. At valve reoperation, larger prostheses could be implanted, suggesting continued annular growth.

The Rastelli Procedure for Transposition of the Great Arteries: Resection of the Infundibular Septum Diminishes Recurrent Left Ventricular Outflow Tract Obstruction Risk

BACKGROUNDnThe Rastelli procedure is the standard surgical treatment of d-transposition of great arteries (d-TGA), ventricular septal defect (VSD), and pulmonary stenosis. Late morbidity is significant due to recurrent left ventricular outflow obstruction (LVOTO), early conduit obstruction, and arrhythmias, with troublesome late mortality. To avoid recurrent LVOTO, we routinely enlarge the VSD and resect the infundibular septum before LV baffling to the aorta. We examined the efficacy of this approach in mitigating recurrent LVOTO risk.nnnMETHODSnLate echocardiographic and time-related clinical results of patients undergoing the Rastelli procedure were examined. Demographics and operative variables affecting outcomes were analyzed.nnnRESULTSnThe Rastelli cohort comprised 36 patients with d-TGA, VSD, and pulmonary stenosis. Median age at operation was 2.4 years (range, 0.3 to 8.3 years). Pulmonary stenosis was present in 31 and atresia in 5. Twenty-two patients had undergone a previous aortopulmonary shunt, and 6 had an atrial septectomy. No operative or late deaths occurred. Time-related freedom from permanent pacemaker implantation, recurrent LVOTO on echocardiogram, and conduit replacement at 10 years was 82%, 100%, and 49%, respectively. Systolic function was normal in all but 3 patients and 92% were in New York Heart Association functional class I and II. None of the patients had late arrhythmias or required heart transplantation.nnnCONCLUSIONSnEarly and midterm survival after the Rastelli procedure is satisfactory. Aggressive resection of the infundibular septum to enlarge the VSD has mitigated the risk of LVOTO recurrence. Late conduit obstruction remains an important source of morbidity and frequently requires reintervention.

Older children at the time of the Norwood operation have ongoing mortality vulnerability that continues after cavopulmonary connection

OBJECTIVESnDelayed first-stage palliation of children with hypoplastic left heart syndrome and related pathologies can be associated with poor outcomes because of development of progressive pulmonary vascular disease and volume load effects on the systemic ventricle and atrioventricular valve. We examine the current eras survival in this subgroup.nnnMETHODSnFifty-five infants older than 2 weeks underwent the Norwood operation (2003-2007). Separate competing risk analyses were performed to model outcomes (death and transition to the next stage) after the Norwood operation and after bidirectional cavopulmonary connection.nnnRESULTSnMedian age was 32 days (range, 15-118 days). Forty-seven percent had hypoplastic left heart syndrome, and 53% had other complex univentricular variants. Mean ascending aortic size was 4.4 ± 1.9 mm, 10% had impaired ventricular function, 11% had moderate atrioventricular valve regurgitation, and 32% had restrictive pulmonary venous return. Pulmonary blood flow was established through an aortopulmonary shunt (n = 30) or Sano shunt (n = 25). After the Norwood operation, patients required longer ventilation and more oxygen and nitric oxide and had higher inotropic scores compared with those undergoing the traditional management protocol. Competing risks analysis showed that 2 years after the Norwood operation, 39% had died, and 57% underwent bidirectional cavopulmonary connection. Four years after bidirectional cavopulmonary connection, 15% had died, and 85% underwent the Fontan operation. Overall 3-year survival after the Norwood operation was 53%. Factors associated with mortality were age, lower weight at the time of the Norwood operation, impaired ventricular function, longer circulatory arrest, and lower pre-bidirectional cavopulmonary connection saturation.nnnCONCLUSIONSnChildren older than 2 weeks undergoing the Norwood operation frequently require postoperative pulmonary vasodilatation and high inotropic support. A significant hazard of death persists through all steps of multistage palliation. Increased pulmonary vascular resistance and volume load effects, such as systemic ventricular impairment and atrioventricular valve regurgitation, are commonly evident in patients in whom treatment fails or who do not qualify to proceed to the next stage of palliation. Those patients should be closely monitored for timely referral for heart transplantation when indicated.

Outcomes and associated risk factors for mitral valve replacement in children

OBJECTIVEnWe aim to report time-related outcomes following mitral valve replacement (MVR) in children and to identify factors affecting outcomes.nnnMETHODSnClinical records from 307 children who underwent MVR between 1985 and 2004 were reviewed. Competing-risks methodology determined time-related prevalence of three mutually exclusive end-states: death, mitral reoperation and survival without subsequent MVR, and their associated risk factors.nnnRESULTSnMean age was 11.4 ± 5.6 years including 36 (12%) patients < 2 years old. There were 154 (50%) males. Underlying pathology was rheumatic fever (n = 195, 64%), congenital (n = 83, 27%) and other (n = 29, 9%) with congenital pathology predominant in younger children while rheumatic fever predominant in older children. Hemodynamic manifestation was regurgitation (83%), stenosis (5%), or mixed disease (12%). One hundred and twenty-six patients (41%) had undergone a prior cardiac surgery including mitral surgery (n = 96, 31%). Initial mitral prosthesis was mechanical (n = 229, 75%), tissue (n = 71, 23%), or homograft (n = 7, 2%). Concomitant cardiac surgery was required in 141 patients (46%). Competing-risks analysis predicted that 20 years following MVR, approximately 17% of patients have died, 51% have undergone mitral reoperation and only 33% were alive and free from mitral reoperation. Risk factors for death without mitral reoperation included younger age < 3 years [PE (parameter estimates): +1.66 ± 0.31, p < 0.001], longer cross-clamp time (PE: +0.11 ± 0.04/10 min, p = 0.005), postoperative complications (PE: +1.5 8 ± 0.31, p < 0.001), and higher prosthesis size/body surface area (BSA)-predicted mitral annulus ratio (PE: + 0.48 ± 0.10, p < 0.001). Risk factors for mitral reoperation included implantation of homograft or tissue prosthesis (PE: +1.12 ± 0.23, p < 0.001) and smaller prosthesis size (PE: +0.06 ± 0.03/1 mm, p = 0.05). Fifteen-year freedom from pacemaker implantation, endocarditis, bleeding, and thromboembolism was 92%, 96%, 82%, and 92%, respectively.nnnCONCLUSIONSnMortality and mitral reoperation are common after MVR in children and outcomes can be predicted based on patients age, prosthesis size, and other associated factors. Some modifiable factors such as avoiding oversized prostheses may improve outcomes especially in the smallest children.