Bronchial artery revascularization in lung transplantation: techniques, experience, and outcomes.

PURPOSE OF REVIEW: Lung transplantation (LTX) is routinely performed ignoring the bronchial arteries. In this article, we review the published world experience, including our own, of LTX with direct bronchial artery revascularization (BAR) and describe the anatomy of the bronchial arteries and our surgical technique. RECENT FINDINGS: The published experience of LTX with BAR consists of only a few small single-institution series, all with good success rates and outcomes. The bronchial artery anatomy will allow identification of useful arteries for BAR in most donors and double LTX (DLTX) with BAR is almost always possible. For single LTX (SLTX), BAR is feasible in about 50%. The surgical techniques for DLTX and SLTX with BAR has been well described. Our own combined Copenhagen and Cleveland experience, all BAR procedures performed or supervised by G.B.P., include a total of 131 LTX with BAR. BAR was performed with a success rate of over 90%, DLTX 95%. Success was uniformly associated with normal airway healing and the overall Copenhagen 5 and 10-year survival for DLTX with BAR was superior to that reported by other institutions after sequential bilateral lung transplantation. SUMMARY: LTX with BAR is feasible, successful and well tolerated. Success ensures normal airway healing. The Copenhagen experience suggests possible long-term survival benefit inviting to a multicenter study to define the role of BAR in LTX.

Selective retrograde venous revascularization of the myocardium when PCI or CABG is impossible: investigation in a porcine model.

We investigated the possibility of nourishing the myocardium through selective retrograde coronary venous bypass grafting (CVBG) with an off-pump technique and evaluated various methods of monitoring the physiological effects of this procedure. In a porcine model, the left internal mammary artery (LIMA) was anastomosed to the left anterior descending coronary vein (LAD vein) in an off-pump procedure. The LAD vein was ligated proximal to the anastomosis. The LAD artery was ligated proximally. The physiological effects were monitored using microdialysis, tissue oxygen tension, blood flow in LIMA, blood samples, and hemodynamic and histological analyses. As controls, 5 pigs underwent surgery involving only LAD artery ligation without CVBG. CVBG with LAD ligation was performed in 16 pigs; 12 survived CVBG and were monitored for 2-2.5 hours while in sinus rhythm, a 75% salvage rate after an otherwise lethal LAD artery occlusion. Immediately after LAD artery ligation, the anterior wall of the left ventricle became cyanotic and hypokinetic. Over time it regained color and contractility as flow in the LIMA increased. Microdialysis showed a significant increase in lactate. Initially tissue oxygen tension decreased, but with time some recovery was seen. Cardiac troponin T was elevated. Histological analysis showed ischemic changes. In control pigs, microdialysis was performed for 1.5 hours up to LAD artery ligation, after which all pigs died in ventricular fibrillation arrest. No increase in lactate was observed. These results indicate that after LAD artery occlusion, CVBG can nourish the myocardium to a certain extent and prevent death in the majority of cases, although varying degrees of ischemia remain.

Major aorto-pulmonary collateral arteries of patients with pulmonary atresia and ventricular septal defect are dilated bronchial arteries.

OBJECTIVE: To test the hypothesis that major aorto-pulmonary collaterals (MAPCAs) have the same anatomy as bronchial arteries. METHODS: Two hundred and thirty-eight angiographies performed on 61 patients with pulmonary atresia, ventricular septal defect (VSD), and MAPCAs constituted the basis for this study. This represented all available angiographies performed on this patient group at our institution during the period 1972-2001. MAPCA anatomy was compared to bronchial artery anatomy as described in previous publications. RESULTS: Each patient had one to five MAPCAs (mean 3.2+/-0.94). A mean of 2.6+/-0.66 MAPCAs came from the descending aorta. MAPCAs with anatomy similar to right intercosto-bronchial arteries were found in 87% of the patients. Fifty percent of the patients had MAPCAs originating from the subclavian artery regions. These numbers were all similar to those previously described for bronchial arteries. All MAPCAs had anatomy similar to bronchial arteries. The distribution in different branching patterns of MAPCAs arising from the aorta was similar to the distribution of bronchial arteries described in previous angiographic studies (p=0.32 and p=0.24). CONCLUSIONS: In patients with pulmonary atresia and VSD, MAPCAs are likely to be dilated bronchial arteries. Bronchial arteries may have limited growth potential and their known vasoreactivity might preclude any long-term beneficial effects of unifocalization procedures.

Absent pulmonary valve syndrome. Surgical and clinical outcome with long-term follow-up.

OBJECTIVE: To identify a large group of patients operated for absent pulmonary valve syndrome (APVS), and describe the outcomes of various subgroups and surgical strategies. METHODS: Thirty-six consecutive patients operated during 1979-2004 were included. Thirty-one percent furthermore had other vascular abnormalities. Eighty-three percent had airway obstruction symptoms before surgery. Twenty-eight percent were ventilator dependent, while 72% underwent repair electively. The median age and weight at repair were 0.8 years (4 days-24 years) and 6.7 kg (1.8-56 kg). The surgical approach was modified several times, including the following: homograft conduit (14%), monocusp valve (39%), and no pulmonary valve (47%). All patients underwent ventricular septal defect (VSD) patching. Seventy-four percent underwent right ventricular outflow tract resection and 91% underwent transannular patching. Pulmonary artery reduction plasty was performed in 86%. RESULTS: The follow-up was 94% complete. Nineteen percent had died. The median follow-up time was 9.2 years (1 day-20.5 years). Survival after repair was 82% at 1 year and 79% at 5, 10, and 15 years. Postoperative survival was strongly associated to preoperative ventilator dependency (p=0.002). The current New York Heart Association (NYHA) classification was established in 93% of survivors. Eighty-nine percent were in NYHA 1 or 2, 11% were in NYHA 3. No patient was in NYHA 4. Freedom from reoperation 1, 5, and 10 years after repair was 78, 65, and 55%, respectively. CONCLUSIONS: The surgical outcome of APVS was closely related to preoperative ventilator dependency. Efforts to improve the surgical outcome should be focused on identifying and correcting this.

High-vacuum drains rival conventional underwater-seal drains after pediatric heart surgery.

OBJECTIVE: The collection of fluid in the mediastinum after cardiac surgery is traditionally prevented using underwater seal drains that may be connected to low-pressure suction. High-vacuum drains (redivac drains) are a potential alternative to this arrangement and have previously been utilized in areas of general surgery, as well as in the treatment of post-sternotomy mediastinitis. There has been no study to date addressing the safety and efficacy of these drains following pediatric cardiac surgery. METHODS: Five hundred and forty-six patients were prospectively randomised to receive either the redivac drains or the conventional underwater-seal drains attached to low-pressure wall suction. We sought to test the null hypothesis that there was no difference in the incidence of residual pericardial or pleural collections requiring drainage between the 2 drainage systems. Secondary endpoints included time to drain removal, volume of drainage and drain size. Analysis was performed on an intention to treat basis. RESULTS: Two hundred and thirty-seven patients were allocated to the redivac group, while 241 were allocated to the conventional drain group. Age and gender distribution, the use of cardiopulmonary bypass, numbers of patients with univentricular morphology and number of drains utilized were similar in the 2 groups. The use of redivac drains resulted in a significantly lower incidence of residual pleural effusions requiring drainage (4 vs. 18, P=0.003). There was no difference in the incidence of pericardial effusion requiring drainage. Redivac drains drained an equivalent volume through smaller calibre tubes (12 Ch vs. 16 Ch, P<0.0001) over a shorter period of time (42h (IQR 22-45) vs. 43h (IQR 27-52), P<0.01) than the conventional drainage system. CONCLUSIONS: Redivac drains are as safe and effective as conventional drains in the pediatric setting, and resulted in a lower incidence of residual pleural effusions requiring drainage. Together with their ease of care, earlier mobilisation of patients and greater cost-effectiveness, the routine use of high-vacuum drains can be recommended following pediatric heart surgery.

Mechanisms of a reduced cardiac output and the effects of milrinone and levosimendan in a model of infant cardiopulmonary bypass.

OBJECTIVES: A low cardiac output state is an important cause of morbidity after pediatric cardiopulmonary bypass. The objectives of our study were to define the early precipitants of the reduced cardiac output and to investigate the effects on these of milrinone and levosimendan in a model of pediatric cardiopulmonary bypass. DESIGN: Experimental study. SETTING: : Research laboratory at a university-affiliated, tertiary pediatric center. SUBJECTS: Eighteen piglets. INTERVENTIONS: Piglets, instrumented with systemic, pulmonary arterial, and coronary sinus catheters, pulmonary and circumflex arterial flow probes, and a left ventricular conductance-micromanometer-tipped catheter, underwent cardiopulmonary bypass with aortic cross-clamp and cardioplegic arrest. At 120 mins, they were assigned to control, milrinone, or levosimendan groups and studied for a further 120 mins. MEASUREMENTS AND MAIN RESULTS: In controls, between 120 and 240 mins, cardiac output decreased by 15%. Systemic vascular resistance was unchanged, but pulmonary vascular resistance increased by 19%. Systemic arterial elastance increased by 17%, indicating increased afterload. End-systolic elastance was unchanged, and coronary sinus oxygen tension decreased by 4.0 +/- 1.7 mm Hg. In animals receiving milrinone cardiac output was preserved, and in animals receiving levosimendan cardiac output increased by 14%. Both drugs prevented an increase in arterial elastance and pulmonary vascular resistance after cardiopulmonary bypass. Systemic vascular resistance decreased by 31% after levosimendan, and end-systolic elastance increased by 48%, indicating improved contractility. Both agents prevented a decrease in coronary sinus oxygen tension. CONCLUSIONS: Increased afterload, which is not matched by an equivalent elevation in contractility, contributes to the reduced cardiac output early after pediatric cardiopulmonary bypass in this model. This increase is prevented by milrinone and levosimendan. Both agents exert additional beneficial effects on pulmonary vascular resistance and myocardial oxygen balance, although levosimendan has greater inotropic properties.

Cor triatriatum: presentation, diagnosis and long-term surgical results.

BACKGROUND: Cor triatriatum sinister is a rare, surgically correctable, congenital cardiac anomaly. Fewer than 250 cases have been reported. It can occur as an isolated defect (classic) or in association with other congenital cardiac anomalies (atypical). METHODS: A retrospective review of 28 consecutive patients diagnosed at the Royal Children's Hospital in Melbourne, Australia during a 22-year span from 1981 to 2003. RESULTS: There were 13 men (46%) and 15 women (54%). Fifteen patients were less than 1 year of age (neonates, [n = 7], 25%; infants, [n = 8], 29%). 17 patients (61%) had a communication between the right atrium and either the proximal or distal chamber. Fifteen patients (54%) had atypical cor triatriatum. Median age at presentation was 6 months (range, 0.6 to 240). Twenty-four patients (86%) had presented by 5 years of age. Five patients (18%) underwent emergency surgery. Median age at operation was 7 months (range, 1 to 243). Twenty-seven patients (96%) underwent preoperative transthoracic echocardiography. Nine patients (32%), all with atypical cor triatriatum, required cardiac catheterization for diagnosis. Twenty-seven patients (96%) were correctly diagnosed before treatment. Twenty-seven patients (96%) were treated surgically. The defect was approached through the right atrium in 26 patients (93%). There was 1 early death and 1 patient died 10 years after repair. Follow-up was 86% complete. At a median follow-up of 98 months (range, 0.2 to 284), all patients including those with atypical cor triatriatum were in New York Heart Association's function class 1. Post-repair survival was 96% and 88% at 5 and 15 years, respectively. CONCLUSIONS: Surgery offers good early and long-term results for both classic and atypical cor triatriatum.

Pulmonary atresia with ventricular septal defects and major aortopulmonary collateral arteries: unifocalization brings no long-term benefits.

OBJECTIVES: We sought to evaluate the contribution of unifocalization procedures in the management of patients with pulmonary atresia, ventricular septal defect, and major aortopulmonary collateral arteries. METHODS: From 1975 through 1995, 82 consecutive patients were entered in a multistage approach and had 189 sternotomies and thoracotomies to perform 119 shunts, 130 major aortopulmonary collateral artery transplantations, and 76 major aortopulmonary collateral artery ligations. The serial angiographies and the follow-up of these patients were reviewed. RESULTS: The concurrent follow-up rate was 80%. The hospital mortality of the preliminary procedures was 4% (7/189). Fifty-three (65%) patients had a complete repair. The hospital mortality of the repair was 8% (4/53), and 9 late deaths occurred after repair, all of which were cardiac related. The overall survival of all patients to the age of 30 years was 58% +/- 7%. Survival 12 years after complete repair was 51% +/- 14%. On angiography, central shunts promoted growth of central pulmonary arteries in all cases (29 patients). Sixty unifocalized major aortopulmonary collateral arteries were identified in 31 patients. After a mean of 3.2 +/- 4 years, 26 thrombosed, and 12 presented with a stenosis of greater than 50%. Serial measurements of 29 major aortopulmonary collateral arteries showed no signs of growth (P = .25). CONCLUSION: Long-term survival into adulthood of patients with pulmonary atresia, ventricular septal defect, and major aortopulmonary collateral arteries has been achieved with a multistage approach. However, late survival depends exclusively on the growth of the native pulmonary circulation. The few unifocalized major aortopulmonary collateral arteries that did not thrombose failed to grow.