Clement S.W. Chiu

Coronary artery fistulas: long-term results of surgical correction

BACKGROUND Opinions vary as to whether operation should be offered patients with coronary artery fistula, particularly to those who are asymptomatic. Published studies lacked long-term follow-up data. METHODS We studied 41 patients with coronary artery fistula operated in our unit in the past 30 years with restudies including coronary angiograms in those who agreed to the investigation. RESULTS There was no operative mortality and operative morbidity was low. The mean duration of follow-up was 9.1 years and 96.9% of the patients were asymptomatic. Twenty-one patients had a coronary angiogram. The native coronary artery either remained dilated and tortuous, or more frequently had thromboses with a short proximal stump. (None of these patients had evidence of myocardial ischemia.) Four patients had demonstrable recurrence fistula but without hemodynamic disturbance. CONCLUSIONS We advocate operation for all patients with coronary artery fistulas and demonstrable shunting in view of minimal operative risks. Small asymptomatic fistulas without demonstrable shunting should be left alone. The relatively high incidence of residual or recurrent fistula makes long-term follow-up mandatory.

Peritoneal dialysis after surgery for congenital heart disease in infants and young children

BACKGROUND We determined the risk factors for peritoneal dialysis (PD) in young children undergoing open heart surgery and, in those patients requiring PD, factors associated with prolonged PD and mortality. METHODS The clinical records of 182 children, aged 3 years or younger, who had undergone open heart surgery during a 2-year period were reviewed. Demographic data, preoperative risk factors, intraoperative variables, and postoperative complications were compared between patients requiring PD and those who did not, and between survivors and nonsurvivors of PD. RESULTS Of the 182 patients, 31 (17%) required PD. Patients requiring PD were lighter and more likely to have required preoperative ventilation; had undergone more complex surgery requiring longer bypass and circulatory arrest; and had experienced a pulmonary hypertensive crisis (p < 0.01). Logistic regression identified circulatory arrest (relative risk, 9.4; p = 0.002), cardiopulmonary bypass duration (relative risk, 1.02; p = 0.028), and low cardiac output syndrome (relative risk, 12.9; p < 0.0001) as significant determinants. Peritoneal dialysis was effective in achieving negative fluid balance, although serum urea and creatinine levels remained static. Prolonged PD was associated with younger age, higher preoperative serum creatinine, higher postoperative oxygen requirement, postoperative pulmonary hypertensive crisis, and low cardiac output syndrome (p < 0.05). When compared with survivors (n = 22), nonsurvivors (n = 9) were more likely to have had syndrome disorders and required preoperative ventilation and higher postoperative ventilatory settings (p < 0.05). CONCLUSIONS Risk factors for PD in young children undergoing open heart surgery are circulatory arrest, cardiopulmonary bypass duration, and low cardiac output syndrome. The preoperative and postoperative cardiopulmonary status has a significant bearing on PD duration and patient survival.

Assessment of left ventricular function long term after arterial switch operation for transposition of the great arteries by dobutamine stress echocardiography

Objectives: To use dobutamine stress echocardiography to determine left ventricular (LV) function and wall motion of children long term after arterial switch operation (ASO) for transposition of the great arteries. Design and patients: 31 patients (24 boys) with ASO performed at a mean (SD) of 15.5 (4.3) days of life were studied at an age of 9.4 (2.0) years. All had normal coronary angiographic findings. LV echocardiographic indexes, including fractional shortening, ejection fraction, rate corrected velocity of circumferential fibre shortening (VCFc), and wall stress, as well as LV wall motion abnormalities were determined at rest and under dobutamine stress. The results were compared with those of 20 healthy age matched control participants. Setting: Tertiary paediatric cardiac centre. Results: Fractional shortening, ejection fraction, and VCFc were significantly lower in patients than in controls at rest (all with p < 0.001). Stress–velocity index detected impaired LV contractility in 19 (61%) patients at rest. An older age at operation (p  =  0.01), longer bypass (p  =  0.01) and circulatory arrest times (p  =  0.045), and an unusual coronary artery pattern (p  =  0.059) were associated with impaired resting LV contractility. Dobutamine stress echocardiography unmasked wall motion abnormalities in 23 (74%) patients. Exercise myocardial perfusion scan, performed in 22 patients, showed reversible myocardial perfusion defects in 17. These defects corresponded to segments of hypokinesia as detected by dobutamine stress echocardiography. Conclusion: A significant proportion of children, albeit asymptomatic, had impaired baseline LV contractility and reversible myocardial perfusion defects and mild wall motion abnormalities on stress after ASO.

Analysis of indications for surgical closure of subarterial ventricular septal defect without associated aortic cusp prolapse and aortic regurgitation

Subarterial ventricular septal defect (VSD) is relatively common in Orientals. We reviewed the outcome of 214 patients (137 males) who were followed for 8.6 +/- 5.2 years (range 0.1 to 24.3) and addressed the issue regarding the necessity and optimum timing of closing subarterial defects before development of aortic valve deformities. Demographic data, transthoracic and transesophageal echocardiographic findings, cardiac catheterization results, and operative findings were reviewed. Kaplan-Meier actuarial analysis was performed to assess the development of aortic valve complications over time. Seventy-five patients with heart failure and pulmonary hypertension underwent surgical closure of VSD at the age of 2.4 +/- 2.9 years. No patient had aortic cusp prolapse before operation and none developed aortic cusp prolapse or aortic regurgitation (AR) on follow-up. In contrast, of the 139 asymptomatic patients managed conservatively, 102 (73%) developed aortic cusp prolapse, 78% of whom (80 of 102) developed AR. The prevalence of aortic cusp prolapse and AR at 1, 5, 10, and 15 years old was 8%, 30%, 64%, and 83%, and 3%, 24%, 45%, and 64%, respectively. Significant prolapse or AR prompted surgical closure of VSD with (n = 22) or without (n = 26) valvoplasty in 48 of 102 patients (47%). The size of the VSD was significantly larger in patients with heart failure (9.6 +/- 3.3 mm) or aortic cusp prolapse (11.7 +/- 4.1 mm) compared with those without heart failure (4.5 +/- 1.4 mm, p <0.001). All patients with aortic cusp prolapse and all but 1 with heart failure had a defect size of > or =5 mm. In conclusion, subarterial VSD of > or =5 mm should be closed as early as possible to prevent development of aortic cusp prolapse and AR. Asymptomatic patients with small defects <5 mm could be managed conservatively.

Risk factors prolonging ventilation in young children after cardiac surgery: Impact of noninfectious pulmonary complications.

Objective To determine risk factors for prolonged ventilation after cardiac surgery in young children and assess the impact of noninfectious pulmonary complications on ventilatory duration. Design Retrospective case series analysis. Setting A tertiary pediatric cardiac center. Patients Clinical records of 222 consecutive children aged ≤3 yrs undergoing cardiac surgery for congenital heart disease were reviewed. Fifteen patients, consisting of six premature babies and nine who died within 72 hrs of surgery, were excluded. Measurements and Main Results The demographic data, preoperative risk factors, surgical procedures performed, intraoperative variables, and postoperative complications of the remaining 207 children were reviewed. Univariate analysis was performed to compare patients who required prolonged ventilation (>72 hrs) to those who could be extubated at ≤72 hrs, and multivariate analyses were performed to identify significant determinants on ventilatory duration and impact of noninfectious complications. Of the 182 patients undergoing open heart surgery, 45 (25%) required prolonged ventilation for a median of 8 days. The latter were significantly younger in age and lighter in weight and were more likely to have Down syndrome, preoperative pulmonary hypertension and ventilatory support, undergone more complex surgery requiring longer bypass and circulatory arrest time, postoperative cardiovascular and pulmonary complications, and extubation failure (all p values <.01). Of the 25 patients who had closed heart surgery, five (20%) required prolonged ventilation for a median of 14 days. The latter were more likely to require preoperative ventilation, have undergone more complex surgery, had postoperative cardiovascular and pulmonary complications, and had extubation failure (all p values <.05). Cox proportional hazard regression identified body weight (p < .001), Down syndrome (p = .02), need for preoperative ventilation (p < .001), complexity of surgery (p < .001), cardiovascular complications (p < .001), and infective (p < .001) and noninfective (p < .001) pulmonary complications to be significant factors that determined the ventilatory duration. Noninfectious pulmonary complications occurred in 31.9% (58/182) and 20% (5/25) of patients after open and closed heart surgery, respectively. In the absence of other risk factors, the median time to extubation was similar between patients with and without noninfectious complications (1 vs. 0.8 day). However, in the presence of other risk factors, noninfectious pulmonary complications prolonged the median time to extubation from 8 to 18 days. Logistic regression identified Down syndrome (p = .005), preoperative ventilation (p = .001), complexity of surgery (p = .006), and bypass time (p = .005) as risk factors for development of noninfectious pulmonary complications. Conclusions Noninfectious pulmonary complications that occurred commonly after cardiac surgery in young children prolong ventilatory duration only in the presence of other risk factors, with which it acts in a synergistic fashion.

Multidrug-resistant tuberculosis in a lung transplant recipient

Tuberculosis infection has been a relatively rare complication after lung transplantation. However, as more countries in which Mycobacterium tuberculosis infection remains endemic embark on lung transplant programs, the occurrence of multidrug-resistant tuberculosis after transplantation is a genuine threat. We report the first case of multidrug-resistant tuberculosis in a double-lung transplant recipient who probably acquired the disease from the donor. We discuss the problems in clinical management of post-transplant tuberculosis infection and of drug-resistance.

Outcome of infants with right atrial isomerism: is prognosis better with normal pulmonary venous drainage?

Objective: To compare the outcome of infants and children who have right atrial isomerism and normal pulmonary venous drainage with those who have anomalous drainage, and to determine factors associated with poor outcome. Design and patients: Retrospective review of management and outcome of 116 infants and children determined to have right atrial isomerism between January 1980 and December 2000. Setting: Tertiary paediatric cardiac centre. Results: The 116 patients presented at a median of one day (range 1 day to 3.7 years) with cyanosis in the majority (96%). No interventions were planned in 31 (27%) patients, all of whom died. The early surgical mortality for pulmonary venous repair was 25% (2 of 8), Fontan procedure 26% (5 of 19), cavopulmonary shunting 7.7% (1 of 13), and systemic pulmonary arterial shunt insertion 1.9% (1 of 53). Late mortality was related to infection (n = 10), sudden death of unknown aetiology (n = 7, 5 with history of arrhythmia), and documented arrhythmia (n = 1). Patients with obstructed anomalous pulmonary venous drainage had the worst survival (p < 0.001). The mean (SEM) survival estimates for those with normal pulmonary venous drainage at 1, 5, 10, and 15 years was 81 (5.3)%, 67 (6.6)%, 60 (7.8)%, and 43 (12)%, respectively, similar to those for patients with non-obstructed anomalous drainage (p = 0.06). Independent risk factors for mortality included pulmonary venous obstruction (relative risk 3.8, p = 0.001) and a single ventricle (relative risk 2.9, p = 0.016). An analysis of only patients with normal pulmonary venous drainage identified no risk factors for mortality. Conclusions: The long term outcome of infants and children with right atrial isomerism in association with a normal pulmonary venous drainage remains unfavourable. Sepsis and sudden death that may potentially be related to cardiac arrhythmia are major causes of late mortality.

Evolution of the management approach for pulmonary atresia with intact ventricular septum

Objective: To review the evolution of the management approach for pulmonary atresia with intact ventricular septum (PAIVS) in the past two decades and to assess its impact on patient outcomes. Design and patients: Retrospective review of the management and outcomes of 94 patients (55 male patients) with PAIVS diagnosed between July 1980 and August 2003. Settings: Tertiary paediatric cardiac centre. Results: Seven patients died before interventions. Of the remaining 87 patients who underwent intervention at a median age of 9 days (from 1 day to 2 years), 12 had right ventricular outflow tract reconstruction (RVOTR), 42 had closed pulmonary valvotomy (CPV), and 15 had laser assisted valvotomy with balloon valvoplasty. A systemic–pulmonary shunt was inserted in 18 patients, six of whom had subsequent RVOTR (n  =  4) or laser assisted valvotomy (n  =  2). Since 1990, catheter intervention accounted for 38% (17 of 45) of the right ventricular outflow procedures. The mean (SEM) freedom from reintervention was 93 (7)%, 71 (12)%, and 57 (13)% after RVOTR, 75 (7)%, 40 (8)%, and 14 (6)% after CPV, and 54 (13)%, 24 (12)%, and 16 (10)% after laser assisted valvotomy at one month, six months, and one year, respectively (RVOTR versus CPV, p < 0.001; RVOTR versus laser assisted valvotomy, p  =  0.001). Low cardiac output syndrome was significantly less common after catheter intervention than after RVOTR (0% v 44%, p  =  0.003) or CPV (0% v 29%, p  =  0.01). The overall mean (SEM) survival was 77 (5)% and 70 (5)% at one and five years, respectively, and the overall mortality was 33% (29 of 87). There were no significant differences in survival between the three groups. Conclusions: Multiple interventions are often required in the treatment algorithm of PAIVS. The shift towards increased use of the transcatheter approach has reduced the occurrence of postprocedural low cardiac output syndrome.

Pericardial effusion after open heart surgery for congenital heart disease

Objectives: To determine the prevalence and time course of pericardial effusion after open heart surgery for congenital heart diseases and to identify predisposing risk factors. Design and patients: Prospective assessment of development of pericardial effusion in 336 patients (163 males) undergoing open heart surgery for congenital heart disease by serial echocardiography on days 5, 7, 14, 21, and 28 postoperatively. Setting: Tertiary paediatric cardiac centre. Results: The prevalence of pericardial effusion was 23% (77 of 336). Of the 77 patients who developed effusion, 43 (56%) had moderate to large effusions and 18 (23%) were symptomatic. Patients who had a large amount of effusion were more likely to be symptomatic than those with only a small to moderate amount (47.4% v 15.5%, p = 0.01). The mean (SD) onset of pericardial effusion was 11 (7) days after surgery, with 97% (75 of 77) of cases being diagnosed on or before day 28 after surgery. The prevalence of effusion after Fontan-type procedures (60%, 6 of 10) was significantly higher than that after other types of cardiac surgery: repair of left to right shunts (22.1%, 43 of 195), repair of lesions with right ventricular outflow tract obstruction (22.6%, 19 of 84), arterial switch operation (6.7%, 1 of 15), and miscellaneous procedures (25%, 8 of 32) (p = 0.037). Univariate analyses showed that female patients (p = 0.009) and those receiving warfarin (p = 0.002) had increased risk of postoperative pericardial effusion. A greater pericardial drain output in the first four hours after surgery also tended to be significant (p = 0.056). Multivariate logistic regression similarly identified warfarin treatment (β = 1.73, p = 0.009) and female sex (β for male = −0.63, p = 0.037) as significant determinants. Conclusions: Pericardial effusion occurs commonly after open heart surgery for congenital heart disease. Serial echocardiographic monitoring up to 28 days postoperatively is indicated in selected high risk patients such as those with symptoms of postpericardiotomy syndrome and those given warfarin.

Intraoperative TEE Assessment of Ventricular Septal Defect With Aortic Regurgitation

BACKGROUND It is desirable to repair but not replace the aortic valve in patients with ventricular septal defect and acquired aortic regurgitation. Precise definition of the valvar pathology with monitoring of its repair perioperatively would enhance the surgical management of this condition. METHODS Fourteen consecutive patients (age, 10.6 +/- 6 years; weight 29.7 +/- 5.7 kg) who underwent repair of ventricular septal defect with aortic regurgitation were studied by intraoperative transesophageal echocardiography. The severity of prolapse of each of the individual aortic cusps and its adjacent sinus was assessed and the valvar regurgitation quantified by Doppler-derived regurgitant indices. The echocardiographic and surgical findings were correlated and the preoperative and postoperative echocardiographic data were compared to assess the effectiveness of operation. RESULTS Eight subarterial and six perimembranous defects were located accurately and their sizes (11.8 +/- 3.0 mm) correlated well (r = 0.80) with the surgical measurements. Transesophageal echocardiography detected prolapse of the aortic valve and its sinus in all 14 patients. The severity of the prolapse was severe in 10, moderate in 4, and mild in 5 leaflets. One the basis of these findings, together with the Doppler-derived mean regurgitant indices, exploration of the valve and valvuloplasty were executed appropriately in 12 of 14 patients. In all 14 patients, transesophageal echocardiography after bypass revealed no further cuspal prolapse and significant reduction of the mean regurgitant index (0.55 +/- 0.23 to 0.17 +/- 0.15, p < 0.0001). Residual ventricular septal defect was detected in 5 patients and the only patient with significant shunting who required reexploration was identified correctly. CONCLUSIONS Intraoperative transesophageal echocardiography can assess effectively the surgical repair of ventricular septal defect with aortic regurgitation and provide information that directs and alters surgical plans to the benefit of patients.