Guido Michielon

Total anomalous pulmonary venous connection: long-term appraisal with evolving technical solutions

OBJECTIVES To evaluate late outcome of non-isomeric total anomalous pulmonary venous connection (TAPVC) repair, controlling for anatomic subtypes and surgical technique. METHODS Between 1983 and 2001, 89 patients (median age 54 days) underwent repair for supracardiac (38), cardiac (26), infracardiac (16) or mixed (nine) TAPVC. Ten patients (11.2%) presented associated anomalies other than PDA. Twenty-eight patients (31.5%) were emergencies, due to obstructed drainage. Supracardiac and infracardiac TAPVC repair included the double-patch technique with left atrial enlargement in 29 patients and side-to-side anastomosis between the pulmonary venous (PV) confluence and the left atrium in 29 patients. Coronary sinus unroofing was preferred for cardiac TAPVC repair. Total follow-up was 727.16 patient-years (mean 8.55 years, 98.8% complete). RESULTS Early mortality was 7.86% (7/89). Ten patients (11.2%) underwent reintervention, including reoperation (eight), balloon dilation (one) and intraoperative stents placement (one), for anastomotic (four) or diffuse PV stenosis (six), with four late deaths. Kaplan-Meier survival is 87.3+/-0.036 SE% at 18.07 years with no difference according to anatomic type or surgical technique. Freedom from PV reintervention for operative survivors is 86.7+/-0.052 SE% at 18.07 years. Cox proportional hazard indicates associated anomalies (P=0.008) and reoperation for intrinsic PV stenosis (P=0.034) as independent predictors of mortality. According to logistic analysis, preoperative obstruction predicts higher risk of reintervention for intrinsic PV stenosis (P=0.022), while the double-patch technique increased the risk of late arrhythmias (P=0.005). CONCLUSIONS Side-to-side anastomosis provides excellent results for TAPVC repair while left atrial enlargement procedures appear to be associated with higher risk of late arrhythmias. Although early and aggressive reintervention for recurrent PV obstruction is mandatory, intrinsic PV stenosis remains a predictor of adverse outcome.

Genetic syndromes and congenital heart defects: how is surgical management affected?

The population of neonates and children with congenital heart defects presents about a 30% prevalence of associated genetic syndrome or additional extracardiac anomalies and may show an increased risk of death or major complication at cardiac surgery. Since a well-defined pattern of combined cardiac and extracardiac anomalies may be found in relation to specific genetic defects, correct understanding of the genetic issues may help improving diagnosis, surgical approach and final outcome of these patients. Hereby we review the medical and surgical issues correlated to the genetic asset in patients with congenital heart defects and genetic syndromes, including trisomy 21, deletion 22q11, Noonan/LEOPARD, Turner, Marfan and Williams syndromes. Recognition of specific surgical risk factors can lead to the preparation of specific diagnostic and perioperative protocols in order to reduce operative mortality and morbidity.

Orthotopic heart transplantation for failing single ventricle physiology

OBJECTIVE Evaluation of incremental risk factors for early mortality in children undergoing orthotopic heart transplantation (OHT) for failing single ventricle physiology. METHODS Between 1988 and 2002, 25 patients (mean age 9.3+/-7.1 years) underwent OHT for complex congenital heart disease (CHD) with a functional right (15 patients) or left (10 patients) single ventricle. Palliative staging towards Fontan completion had been previously accomplished in 22 patients (88%). Transition to OHT occurred from a shunt stage in 10, a bi-directional cavopulmonary anastomosis (BDG) stage in nine, and after Fontan failure in six patients. RESULTS Thirty-day survival was 68.0+/-9.3% with no additional mortality up to 14.1 years. OHT following BDG staging exhibited 100% long-term survival, as opposed to 66.7+/-15.7% for OHT after systemic-to-pulmonary shunt, and 33.3+/-19.2% for OHT following failing Fontan (p=0.032). Regression logistic modelling indicated failing Fontan circulation as predictor of higher mortality after OHT (p=0.041). Reintervention was necessary in four patients 40+/-11 months after OHT to address residual superior vena cava (two) and isthmic (two) stenosis. Overall freedom from reintervention was 88.3+/-8.1% at 5 years. CONCLUSIONS OHT for structural CHD with single ventricle physiology entails substantial early mortality while BDG enables the best transition to heart transplant. OHT should be considered in the decision-making process as an alternative to Fontan completion in high-risk candidates, since rescue-OHT after failing Fontan seems unwarranted.

Anomalous coronary artery origin from the pulmonary artery: correlation between surgical timing and left ventricular function recovery

BACKGROUND This study investigates the correlation between surgical timing and 15-year longitudinal left ventricular and mitral valve function, after repair of anomalous coronary artery origin from the pulmonary artery. METHODS Between 1987 and 2002, 31 patients (median age, 7.1 months) underwent repair for anomalous origin of the left (n = 28), right (n = 2), or both (n = 1) coronary arteries from the pulmonary artery. Repair was accomplished by subclavian interposition in 5 patients, intrapulmonary tunnel in 12, and direct aortic reimplantation in 14. Primary mitral valve repair was never associated with coronary revascularization. Total follow-up was 186.4 patient-years (mean, 77.2 months). RESULTS Fifteen-year actuarial survival was 92.9% +/- 4.9% for coronary transfer, 40.0% +/- 21.9% for subclavian interposition, and 89.9% +/- 7.5% for intrapulmonary tunnel (p = 0.019). Five patients required further intervention for supravalvular pulmonary stenosis (n = 3), baffle leak (n = 1), and mitral valve replacement (n = 1). Coronary transfer allowed best freedom from long-term reoperation (92.3% +/- 7.4%). Left ventricular shortening fraction increased from 17.3% +/- 6.3% before operation to 34.1% +/- 4.6% at last follow-up (p < 0.01). Regression analysis demonstrated a linear relationship between age at repair and shortening fraction recovery (r(2) = 0.573, p < 0.01). Patients younger than 6 months of age showed worse preoperative shortening fraction (15.9% +/- 5.2%) and best longitudinal shortening fraction recovery (36.4% +/- 5.1%; p < 0.001). Major improvement in mitral valve function was observed within 1 year from surgery in 90.4% of survivors. CONCLUSIONS Repair of anomalous coronary artery origin from the pulmonary artery in younger symptomatic infants offers the best potential for recovery of left ventricular function, despite a worse initial presentation. Coronary transfer is associated with superior long-term survival and freedom from reoperation. Most patients with patent two-coronary repair will recover normal mitral valve function; therefore, simultaneous mitral valve surgery seems unwarranted.

Orthotopic Heart Transplantation for Congenital Heart Disease: An Alternative for High-Risk Fontan Candidates?

Objective—Evaluation of incremental risk factors for early mortality in children undergoing orthotopic heart transplantation (OHT) for congenital heart disease. Methods—Between 1988 and 2002, 43 patients (mean age 9.1±7.2 years) underwent 44 OHT for complex TGA (6), DORV (4), single ventricle (21), and other end-stage structural heart disease (11). Two discernible ventricular chambers were present in 18 pts (41.8%). Previous reconstructive or palliative procedures had been previously accomplished in 35 pts (83.3%), including atrial switch (5), systemic-to-pulmonary shunts (10), cavopulmonary anastomosis (9), Fontan completion (6), and others (5). Results—30-day survival for the 2-ventricle subgroup was 94.4±5.4% compared with 67.2±9.5% for the single ventricle subgroup (P =0.04) (overall 78.6%±3.3%). OHT following single ventricle staging to bi-directional cavopulmonary anastomosis exhibited 100% early survival, as opposed to 62.5±17.1% for OHT after systemic-to-pulmonary shunts, and 33.3±19.2% for OHT following failing Fontan (P =0.010). HLHS diagnosis (0.0085) and failing Fontan (P =0.003) were identified as independent predictors of early mortality by regression logistic modeling, while Fontan stage represented the only predictor of overall mortality by Cox proportional hazard. Overall 10-year survival was 54.3±11%. Conclusions—OHT for structural congenital heart disease with single ventricle physiology entails substantial early mortality and bi-directional cavopulmonary anastomosis enables the best transition to heart transplant. OHT should be considered in the decision making process as an alternative to Fontan completion in high-risk candidates, since rescue-OHT after failing Fontan seems unwarranted.

Protein-losing enteropathy after Fontan surgery: resolution after cardiac transplantation.

Protein-losing enteropathy (PLE), defined as severe loss of serum protein into the intestine, occurs in 4% to 13% of patients after the Fontan procedure. We report a case of PLE reversal after heart transplantation in a 14-year-old boy with Fontan circulation who previously was treated unsuccessfully with medical therapy. The protein loss continued after heart transplantation. We administered total parenteral nutrition to rest the bowel. After 16 months, we observed a gradual decrease in protein loss. The patient is doing well 5 years after heart transplantation and had has a normal serum albumin level.

Impact of DEL22q11, trisomy 21, and other genetic syndromes on surgical outcome of conotruncal heart defects

OBJECTIVE Genetic syndromes occur in more than 20% of patients with conotruncal heart defects. We investigated the impact of genetic syndromes on the surgical outcome of conotruncal anomalies in infancy. METHODS This retrospective study reviews the outcome of 787 patients (median age 6.3 months) who underwent primary (598) or staged (189) repair of a conotruncal defect between 1992 and 2007. RESULTS Proven genetic syndrome was diagnosed in 211 patients (26.8%), including del22q11 (91 patients), trisomy 21 (29 patients), VACTERL (18 patients), and other syndromes (73 patients). Primary repair was accomplished in 80.9% of nonsyndromic patients and 74.4% of syndromic patients (P = .18) Fifteen-year cumulative survival was 84.3% +/- 2.3% in nonsyndromic patients and 73.2% +/- 4.2% in syndromic patients (P < .001). Primary and staged repair allowed similar 15-year survival (81.4% +/- 4.5% vs 79.1% +/- 5.1%, P = .8). Freedom from noncardiac cause of death was significantly lower in syndromic patients (P = .0056). Fifteen-year Kaplan-Meier survival was 87.6% +/- 3.9% for del22q11, 95.8% +/- 4.1% for trisomy 21, 56.8% +/- 6.3% for VACTERL, and 62.3% +/- 12.7% for patients with other syndromes (P = .022). Total intensive care unit stay was 10.8 +/- 4.9 days in syndromic patients and 5.1 +/- 1.7 days in nonsyndromic patients (P < .001). Freedom from reintervention 15 years after repair was 79.6% +/- 4.9% in nonsyndromic patients and 62.4% +/- 7.4% in syndromic patients (P = .007). CONCLUSION Del22q11 and trisomy 21 do not represent risk factors for mortality after repair of conotruncal anomalies, whereas other syndromes adversely affect the surgical outcome for predominant noncardiac attrition. Higher morbidity and lower mid-term freedom from reintervention can be predicted in syndromic patients.

Mechanical Assist Device as a Bridge to Heart Transplantation in Children Less Than 10 Kilograms

BACKGROUND Despite the remarkable advances with the use of ventricular assist devices (VAD) in adults, pneumatic pulsatile support in children is still limited. We report a retrospective review of our experience in very small children (<10 kg of body weight). METHODS Ten consecutive children weighing less than 10 kg were offered mechanical support with Berlin Heart (Berlin Heart AG, Berlin, Germany) as a bridge to heart transplant from March 2002 to March 2010. RESULTS The median patient age was 10.4 months (38 days to 2.2 years). The median patient weight was 6.4 kg (2.9 to 10 kg). Prior to VAD implantation, all children were managed by multiple intravenous inotropes and mechanical ventilation (8) or extracorporeal membrane oxygenation (2). The median pre-VAD pulmonary vascular resistance index was 5.7 Woods units/m(2). Three patients required biventricular mechanical support, but in all other cases a single left VAD proved sufficient. The median duration of VAD support was 61 days (2 to 168 days). Four deaths occurred; from stroke in three and sepsis in one. Five patients were successfully bridged to heart transplantation after a median duration of mechanical support of 89 days (37 to 168 days) and another is still waiting a suitable organ after 77 days of VAD support. There were no complications related to postoperative bleeding. Five patients required at least one pump change. Of 5 patients undergoing heart transplant, 3 developed an extremely elevated (>60%) panel reactive antibody by enzyme-linked immunosorbent assay, confirmed by Luminex (Luminex Corp, Austin, TX). All 3 experienced at least one acute episode of rejection in the first month after heart transplant, needing plasmapheresis. The survival rate after heart transplantation was 100% with a median follow-up of 7.5 months. CONCLUSIONS Mechanical support in very small children with end-stage heart failure is an effective strategy of bridge to heart transplantation with a reasonable mortality rate. The high rate of complications suggests to optimize indications and timing of VAD implantation.

Inflammatory cytokines in pediatric cardiac surgery and variable effect of the hemofiltration process.

Cardiac surgery with cardiopulmonary bypass (CPB) elicits an inflammatory response and has a multitude of biological consequences, ranging from subclinical organ dysfunction to severe multiorgan failure. Pediatric patients are more prone to have a reaction that can jeopardize their outcome. Cytokines are supposed to be important mediators in this response: limiting their circulating levels is, therefore, appealing. We investigated the pattern of cytokine release during pediatric operation for congenital heart anomalies in 20 patients, and the effect of hemofiltration. Tumor necrosis factor a (TNF-α) was elevated after anesthesia induction and showed significant decrease during CPB. Hemofiltration reduced its concentration, but the effect disappeared on the following day. Interleukin-1 (IL-1) increased slowly at the end of CPB and hemofiltration had no effect. Interleukin-6 (IL-6) showed a tendency toward augmentation during rewarming and hemofiltration did not significantly affect the course. Soluble interleukin-6 receptor (sIL-6r) had a pattern similar to TNF-α, but hemofiltration had no effect. On the other hand, interleukin-8 (IL-8) behaved like IL-6. Our findings suggest that baseline clinical status, anesthetic drugs, and maneuvers before incision may elicit a cytokine response, whereas rewarming is a critical phase of CPB. Hemofiltration is effective in removal of TNF-α, but its role is debatable for the control of IL-1, IL-6, sIL-6r and IL-8 levels.

Modified Button-Bentall Operation for Aortic Root Replacement: The Miniskirt Technique

BACKGROUND The aim of this study was to evaluate the midterm results of a modified button-Bentall operation (modified-bB) specifically designed to incorporate any type of prosthetic valve in composite conduit aortic root replacement. METHODS Between 1991 and 2000, a total of 135 patients underwent modified-bB for annuloaortic ectasia (74 patients), type A dissection (31), or aortic aneurysm without dissection (30). Of these, 34 were emergencies (25.2%). A total of 50 bioprostheses (study group 1) and 85 bileaflet mechanical prostheses (study group 2) were implanted. Group 1 mean age was 66.9 +/- 7.4 years versus 51.5 +/- 12.1 years in group 2 (p < 0.001). Composite-conduit creation occurred during proximal suture line construction as a single-step maneuver. Interrupted extracardiac polyester mattress sutures sequentially entered the aortic annulus, the prosthetic valve ring, and the vascular graft 7 mm from its free edge (miniskirt). Running monofilament suture line secured proximal hemostasis, buttressing aortic remnants and graft edge. Coronary reimplantation was accomplished in all cases by the button technique. Concomitant procedures were performed in 51 patients (37.8%). RESULTS The 30-day mortality was 5.18% (7/135 patients). Eight patients (5.9%) required revision for proximal (1 patient), coronary button (3), or distal (4) anastomosis leakage. Three patients (2.2%) perioperatively developed nonfatal inferior myocardial infarction. Kaplan-Meier 9-year survival is 91.8% +/- 0.026 SE with 88.1% (95% confidence limits 71.7% to 95.5%) reoperation freedom. According to the Cox proportional hazard method, stratification of the risk for death according to prosthesis type indicates previous operation (p = 0.001) and emergency (p = 0.0465) as independent predictors of hospital mortality. Associated procedures to modified-bB increased risk of reoperation (p = 0.031). CONCLUSIONS Modified-bB was associated with low mortality, excellent midterm survival, and freedom from reoperation. Absence of valve-to-graft tapering, reduced coronary button anastomosis tension, and prosthesis selection according to patient profile, are apparent advantages of modified-bB.