Lung transplantation in Hong Kong: 12 years of experience.

BACKGROUND AND OBJECTIVE: A lung transplant programme was launched in August 1994 at Grantham Hospital in Hong Kong with the first single-lung transplant performed in July 1995. A retrospective study was undertaken of all patients who had undergone lung transplantation and their outcomes analysed. METHODS: Data were collected from hospital and outpatient records. RESULTS: There were 12 transplants (two single-lung and 10 double-lung) performed in the 12 years to December 2006. No postoperative or early mortality was observed. In addition to the usual complications there were two cases of early pulmonary tuberculosis and one rare case of delayed fungal sternotomy infection. The 1-year, 3-year and 5-year survival rates were 100%, 100% and 76.2%, respectively. All fatalities were related to the consequences of chronic rejection or its treatment. CONCLUSIONS: Despite the limited experience and the small case volume, the survival of patients was good and comparable with international experience.

Aortic root dilation and aortic elastic properties in children after repair of tetralogy of Fallot.

Analyses of aortic specimens obtained from patients with tetralogy of Fallot (TOF) revealed elastic fiber fragmentation. This study sought to determine the prevalence of aortic root dilation and aortic regurgitation (AR) in children after TOF repair and tested the hypothesis that aortic elastic properties are altered and related to aortic root dilation in these patients. Aortic dimensions, adjusted for body surface area and expressed as z scores, and AR were assessed echocardiographically in 67 children 8.3 +/- 5.6 years after TOF repair. The aortic elastic properties were compared with those in 50 age-matched controls. The prevalence of aortic dilation (z score >2) was 88%, 87%, 61%, and 63% at the annulus, sinus of Valsalva, sinotubular junction, and ascending aorta, respectively. The z scores of the annulus (r = 0.41, p <0.001) and sinus (r = 0.33, p <0.01) were correlated with body surface area. Multivariate analysis identified the duration of follow-up after surgery as the only significant determinant of z scores of the annulus (beta = 0.41, p = 0.001) and sinus (beta = 0.33, p = 0.009). AR was present in 12% of patients who tended to have larger z scores at all aortic levels. Compared with controls, patients had significantly increased aortic stiffness (p <0.001) and reduced strain (p <0.001) and distensibility (p = 0.002). Aortic stiffness was correlated positively, whereas aortic strain and distensibility were correlated negatively, with the aortic root z scores at all levels. In conclusion, this study shows a high prevalence of aortic root dilation in children after the repair of TOF. Aortic stiffening occurred in these patients and may play a role in progressive aortic root dilation.

Treatment and outcome of biopsy-proven fulminant myocarditis in adults.

Fulminant myocarditis may be rapidly fatal with severe haemodynamic compromise in previously healthy patients. We reviewed our experience with eight cases of biopsy-proven fulminant myocarditis (seven cases with lymphocytic myocarditis and one with eosinophilic myocarditis). Immunosuppression was given in seven out of eight cases. Mechanical circulatory support was required in 50% of the patients. Time from onset of illness to recovery of ventricular function varied from 12 to 17 days. All except one patient were alive at a mean follow-up of 4.4 years after the acute illness. Patients with acute fulminant myocarditis should be treated aggressively with immunosuppression and, if necessary, mechanical circulatory support during the first 2 to 3 weeks of the illness because of the reversible nature of this illness and good long-term prognosis.

Long-term anticoagulation therapy and thromboembolic complications after the Fontan procedure.

BACKGROUND: The necessity for chronic anticoagulation of Fontan patients remains controversial. We determined the prevalence of thromboembolic complications after the Fontan procedure in relation to different long-term anticoagulation strategies. METHODS: The clinical outcomes, postoperative anticoagulation strategies and occurrence of thromboembolic complications in 102 ethnic Chinese patients who had undergone Fontan procedure between 1980 and 2002 were reviewed. RESULTS: The early and late surgical mortalities, all unrelated to thromboembolism, were 10.8% (11/102) and 5.8% (6/104), respectively. Of the 85 survivors, 46 (54%) were maintained on long-term warfarin therapy, 8 (9%) on aspirin prophylaxis while 31 (37%) were not on chronic anticoagulation. Four (4.5%) patients, two with and two without warfarin prophylaxis, developed thromboembolic complications at 0.14 to 7.7 years after the Fontan procedure (0.74%/patient-year). Three had a grossly dilated right atrium after atriopulmonary connection, two of whom had atrial fenestrations. The other had atrial tachycardia. Freedom from development of thromboembolic complications (mean+/-S.E.) at 1, 5 and 10 years after surgery was 97+/-19%, 96+/-2.5% and 92+/-4.2%, respectively. When compared with those on long-term warfarin therapy, patients without chronic anticoagulation were followed-up longer (p=0.001), more likely to have undergone atriopulmonary connection (p<0.001), less likely to have fenestrations (p=0.02) and cardiac arrhythmias (p=0.02) but not predisposed to increased risk of thromboembolism (p=1.00). CONCLUSION: The study supports the contention that chronic anticoagulation may not be required for majority of ethnic Chinese Fontan patients. Nonetheless, it may perhaps be considered in those with grossly dilated right atrium, cardiac arrhythmias and residual right-to-left shunts.

Impact of preoperative aortic cusp prolapse on long-term outcome after surgical closure of subarterial ventricular septal defect.

BACKGROUND: Previous reports on the long-term outcome of surgical closure of subarterial ventricular septal defect were based on a relatively small number of patients. METHODS: We reviewed the long-term outcome of 135 patients who underwent closure of their defect and, in light of the findings, assessed the impact of preoperative aortic cusp prolapse and surgical interventions on occurrence of aortic regurgitation (AR) in the long-term. The patients were categorized into three groups for comparison: group I consisted of 79 patients with no aortic cusp prolapse and underwent simple closure of ventricular septal defect, group II comprised 39 patients with mild to moderate cusp prolapse who similarly had only closure of the defect performed, whereas group III comprised 17 patients who had additional aortic valvoplasty for greater than moderate to severe cusp prolapse. RESULTS: Group I patients had significantly higher pulmonary arterial pressure (p < 0.001) and ratio of pulmonary blood flow to systemic blood flow (p < 0.001). None of these patients had AR before their operation, and none experienced AR afterward at a median follow-up of 6.1 years. Of the 39 group II patients, 30 (77%) had trivial or mild AR preoperatively. The AR improved in 15 patients, remained trivial or mild in 14 and absent in 7, but progressed to trivial or mild in 3 at a median follow-up of 3.1 years. None required further interventions. In contrast, 14 (82%) of the 17 group III patients had moderate to severe AR before operation. The regurgitation improved in 10, but remained moderate or severe in 4 and worsened further in 3 at a median follow-up of 4.6 years. The freedom from failure of aortic valvoplasty was (mean +/- standard error of the mean) 71%+/-11%, 64%+/-12%, and 43%+/-19% at 1, 5, and 10 years, respectively. An older age at latest follow-up was the only identifiable significant risk factor (p = 0.03). CONCLUSIONS: Our data do not support the need of aortic valvoplasty for mild to moderate aortic cusp prolapse. Close follow-up is warranted in those with greater than moderate to severe cusp prolapse despite valvoplasty as there is continued failure on follow-up. Nothing, however, is better than early closure of defects before development of aortic valve complications.

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.

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 72 hrs) to those who could be extubated at

Plasma brain natriuretic peptide levels, right ventricular volume overload and exercise capacity in adolescents after surgical repair of tetralogy of Fallot.

BACKGROUND: Right ventricular (RV) volume overload secondary to pulmonary regurgitation contributes to long-term morbidities in patients after tetralogy of Fallot (TOF) repair. We tested the hypothesis that plasma brain natriuretic peptide (BNP) levels relate to RV volume overload, pulmonary regurgitation, and exercise capacity in adolescents after TOF repair. METHODS: We assessed the RV function echocardiographically and plasma BNP levels in 32 postoperative TOF patients aged 14.7+/-3.1 years and 20 age-matched controls. Eighteen patients further underwent cardiovascular magnetic resonance imaging and 26 had exercise testing. RESULTS: Compared with controls, patients had significantly higher BNP levels (p=0.027), greater indexed RV end-diastolic dimension (p<0.001), increased RV myocardial performance index (p=0.005), and reduced tricuspid annular systolic velocity (p=0.008). Multivariate analysis identified indexed RV end-diastolic dimension as the only significant determinant of plasma BNP levels (beta=0.69, p<0.001). Plasma BNP levels correlated positively with indexed RV end-diastolic volume (r=0.6, p=0.009) and pulmonary regurgitant fraction (r=0.54, p=0.026), and negatively with exercise duration (r=-0.45, p=0.021), peak oxygen consumption (r=-0.43, p=0.03), and minute ventilation at maximal exercise (r=-0.52, p=0.006). Multivariate analysis demonstrated BNP levels (beta=-0.43, p=0.034) and body mass index (beta=-0.40, p=0.036) to be independent predictors of peak oxygen consumption. No relations were found between BNP levels and RV myocardial performance index, tricuspid annular velocities and RV ejection fraction. CONCLUSIONS: In adolescent patients after TOF repair, plasma BNP levels relate to RV volume overload, pulmonary regurgitation and exercise capacity.

Pneumatic pump reduces leg wound complications in cardiac patients.

Leg wound complications at the site of vein harvest for coronary artery bypass graft, although infrequent, cause significant morbidity. Pneumatic pressure therapy is valuable in venous and lymphatic diseases, but its usefulness after leg vein harvest has not been determined. A prospective randomized controlled trial was conducted on 200 patients, half of whom had sequential pneumatic leg pump therapy postoperatively. Wound healing, extent of lower limb edema, patient satisfaction, and the financial implications of pneumatic pressure therapy were assessed. In the study group, 71 patients had satisfactory wound healing vs. 23 in the control group. The leg wound infection rate in the study group was 3% vs. 15% in the control group ( p = 0.003). Lower limb edema was significantly reduced in the study group in the early postoperative period ( p < 0.05), and the mean postoperative length of hospital stay was reduced by 2.6 days in patients given pneumatic pressure therapy ( p = 0.003). The sequential pneumatic leg pump is an effective, inexpensive, and convenient device that reduces leg wound complications after coronary artery bypass grafting.

Mitral valve annuloplasty with Carpentier-Edwards physio ring: mid-term results.

The mid-term results of mitral valve repair with the Carpentier-Edwards Physio annuloplasty ring were assessed in 97 consecutive patients in a single tertiary-referral cardiothoracic surgical center. The mean follow-up time was 3.9 years (range, 1 month to 8.9 years). Most patients were in functional class II and III before the operation. Ejection fraction was < 40% in 8 patients. Causes of mitral regurgitation included degenerative disease (66%), infective endocarditis (13.4%), rheumatic disease (10.3%), and ischemic heart disease (9.3%). Thirty-day mortality was 2.1%. Actuarial survival and freedom from re-operation at 8 years were 91% and 90.8%, respectively. The only significant risk factor for re-operation was residual mitral regurgitation. Four patients suffered thromboembolic complications, giving an overall event-free survival of 93% +/- 3.7% during the follow-up period. The Carpentier-Edwards Physio ring provides safe and effective repair of mitral regurgitation on mid-term follow-up.

Non-infectious aortitis: an important cause of severe aortic regurgitation.

From 1995 to 2004, 13 patients with severe aortic regurgitation due to non-infectious aortitis underwent aortic valve surgery at our center. Twenty-eight operations (18 aortic valve replacements and 10 Bentall procedures including 1 aortic root replacement with a homograft) were performed due to a high incidence of prosthetic valve or valved conduit dehiscence (54%). Steroid therapy reduced the incidence of re-operation for anastomotic dehiscence within one year from 90% to 18%. Strategies to prevent dehiscence of the prosthetic aortic valve, which include institution of immunosuppression, replacement of the diseased aorta, and monitoring inflammatory indices, are discussed.

Fate of the unligated vertical vein after repair of supracardiac anomalous pulmonary venous connection.

OBJECTIVE: To determine the fate of the unligated vertical vein after repair of isolated supracardiac total anomalous pulmonary venous connection (TAPVC). METHODS: We reviewed the outcome of 28 patients who were diagnosed to have isolated supracardiac TAPVC and determined the fate of the unligated vertical vein. RESULTS: Of the 28 patients, four died before surgery. The remaining 24 patients underwent surgical correction of TAPVC with (n = 5) or without (n = 19) ligation of vertical vein at a median age of 20 days (range: 1-574 days). There were no significant differences in age, weight, presence of pulmonary venous obstruction, need for preoperative inotropic and ventilatory support, cardiopulmonary bypass duration, postoperative pulmonary hypertensive crisis and requirement of peritoneal dialysis between patients with and those without vertical vein ligation. The in-hospital surgical mortality was 50% (12/24), with 83% (10/12) of deaths occurring before 1990. Patients who died after surgery were significantly younger (median age: 5.5 days vs 37 days, P = 0.005), lighter (3.3 +/- 0.5 kg vs 3.9 +/- 0.6 kg, P = 0.016), more likely to have pulmonary venous obstruction preoperatively (75% vs 12%, P = 0.039) and have undergone surgery before 1990 (83% vs 33%, P = 0.036). The 12 survivors were followed up for a median of 4.7 years (range: 2.3-18.1 years), 10 of whom had their vertical vein unligated. The vertical vein remained patent in five (50%) patients, while stenosis of pulmonary venous anastomosis was only present in one patient. Of these five patients, three had subsequently undergone surgical ligation of the vertical vein to eliminate a large left-to-right shunt. CONCLUSIONS: Patency of the unligated vertical vein is common after the repair of supracardiac TAPVC, even in the absence of pulmonary venous obstruction. The degree of left-to-right shunt through the patent vertical vein may be so significant as to warrant surgical ligation.

A simple method of treating seromas involving modified Blalock-Taussig shunts.

We treated seromas developing in two patients in relation to left-sided modified Blalock-Taussig shunts by reattaching the original graft to the descending aorta. We postulate that seromas may develop because of the large area of contact between the graft and blood. Shortening the length of the Gore-Tex graft may therefore be a feasible treatment.