Anomalous origin of innominate artery from right pulmonary artery in DiGeorge Syndrome.

We experienced a case of anomalous origin of innominate artery from right pulmonary artery (isolated innominate artery). This patient was a 2-month-old baby girl weighing 3.2 kg with DiGeorge syndrome, who was diagnosed with perimembranous ventricular septal defect, atrial septal defect, and patent ductus arteriosus. This type of anomaly is exceedingly rare.

Assisted venous drainage cardiopulmonary bypass in congenital heart surgery.

BACKGROUND: A novel active venous drainage perfusion circuit was designed to achieve effective venous return through small venous cannulas. The efficacy and safety of this new system was investigated and compared with a conventional gravity drainage system. METHODS: Four hundred consecutive patients undergoing open heart repair of congenital heart lesions by one surgeon were studied. The first 200 patients were supported by gravity drainage and the next 200 patients were supported by assisted venous drainage. No patient in the time period was excluded from the study. RESULTS: The two groups did not differ significantly in weight, bypass time, or cross-clamp time. Priming volumes were less in the assisted group than in the gravity group (576+/-232 mL versus 693+/-221 mL, p < 0.001). Venous cannula size was smaller in the assisted group when compared with the gravity group (33.2F+/-7.4F versus 38.5F+/-7.1F, p < 0.001). There was a trend to lower operative mortality in the assisted drainage group (5 of 200, 2.5% versus 11 of 200, 5.5%; p = 0.10). Hospital stay and pulmonary, infectious, and neurologic complications were comparable in both groups. Cardiac complications were less common in the assisted group than in gravity group (22 of 200, 11% versus 38 of 200, 19%; p = 0.017). Hematologic complications were less common in the assisted group than the gravity group (6 of 200, 3% versus 19 of 200, 9.5%; p < 0.01). CONCLUSIONS: These findings suggest that assisted venous drainage is safe in congenital heart operations and facilitates the use of smaller venous cannulas.

Endovascular stent graft treatment of a pulmonary artery pseudoaneurysm.

A 5-year-old girl with pulmonary atresia, ventricular septal defect, hypoplastic pulmonary arteries, and multiple pulmonary artery reconstructive procedures presented with an enlarging pulmonary artery pseudoaneurysm. A previous attempt to occlude the aneurysm was unsuccessful and the aneurysm continued to enlarge. We describe the percutaneous placement of an endovascular stent graft to occlude the aneurysm. This novel use of a covered graft effectively treated a potentially lethal problem without reoperative thoracotomy or sternotomy.

Reducing the trauma of congenital heart surgery.

While describing the circulatory system in De Moto Cordis, in 1628, William Harvey developed precepts for investigation, which could be modified slightly to guide the adoption of new technology and technique in the twenty-first century. Harvey might suggest (1) careful and accurate observation and description of a new technique, (2) a tentative explanation of how the technique improves on existing techniques, (3) a controlled testing of the hypothesis, and (4) conclusions based on the results of the experiments. Also, he might admonish surgery today, with its massively enhanced capabilities for information management, to rigorously test the validity of these conclusions with quantitative reasoning. In the future, precise measurement of the "trauma" of surgery, or even an individual surgeon, may be possible, and the long-term impact of a chest wall incision on a patient's self-esteem may be predictable. Absent such objective measures, justifications for "minimally invasive" deviations from conventional technique in surgery for CHD lack substance. Morbidity, mortality, and physiological endpoints will continue to form the foundation for therapeutic plans; however, the potential for emerging technology to reduce the trauma of these plans remains tantalizing.

Video-assisted cardioscopy for intraventricular repair in congenital heart disease.

BACKGROUND: Video-assisted thoracoscopic surgical techniques have been widely adopted as a means to reduce surgical trauma. By adapting pediatric thoracoscopic instrumentation, we have developed a technique for video-assisted cardioscopy (VAC). We report our experience and describe the technical feasibility of VAC. METHODS: Since June 1995, 409 consecutive patients underwent 431 intracardiac procedures (ventricular septal defect, 150; tetralogy of Fallot or double outlet right ventricle, 101; atrioventricular canal, 52; subaortic stenosis, 43; valve repair, 50; Rastelli procedure, 12; Konno or Ross Konno operation, 11; and miscellaneous, 12) using VAC at Miami Children's Hospital. Using a prospective database, we tracked outcomes and operative events to delineate the usefulness and efficacy of this technique. RESULTS: VAC provided clear and precise imaging of small or remote intracardiac structures during repair of congenital heart defects without technical complications. Procedure times and aortic cross-clamp times using VAC were not prolonged. Intraoperative images were collected for every operation, documenting each patient's cardiac anatomy before and after repair. Surgery through small incisions was facilitated. Operative mortality was 1.2% (5 of 409), and no patient required reoperation before discharge. At a mean follow-up interval of 22 months, the incidence of reoperation for residual or recurrent lesions was 1.2% (5 of 404). CONCLUSIONS: Our experience demonstrates the technical feasibility and clinical utility of routine endoscopic imaging during open heart surgery for congenital heart repair.

Deletion of endothelial nitric oxide synthase exacerbates myocardial stunning in an isolated mouse heart model.

BACKGROUND: While endothelial nitric oxide synthase (eNOS) is an important regulator of vascular tone, it is also constitutively expressed in cardiac myocytes and contributes to the regulation of myocardial function. The role of eNOS in ischemia-reperfusion is uncertain, however, with some studies showing beneficial effects while other studies demonstrate increased cardiac injury. We hypothesized that the beneficial effects of eNOS would predominate, and thus that targeted deletion of eNOS would exacerbate myocardial dysfunction following ischemia-reperfusion. MATERIALS AND METHODS: ENOS knockout and wild-type mouse hearts were Langendorff-perfused using Krebs bicarbonate buffer and subjected to 20 min of global normothermic ischemia followed by 30 min of reperfusion. Myocardial function was measured using a ventricular balloon to determine time to onset of contracture, left ventricular developed pressure (LVDP), left ventricular end-diastolic pressure (LVEDP), and rate-pressure product (RPP). RESUKTS: Heart rate and coronary resistance were similar in both groups during baseline and reperfusion periods. Diastolic function as determined by peak LVEDP during ischemia and final LVEDP after reperfusion were worse in the eNOS knockout group vs wild-type (114 and 31 mmHg vs 92 and 18 mmHg, P <.05). Although RPP (heart rate x LVDP), measured as an index of systolic function, was initially better in eNOS knockouts (24216 vs 16353), wild-type hearts recovered more function than did eNOS knockout hearts by the end of 30 min of reperfusion (30892 vs 20522, P <.05). CONCLUSIONS: These data suggest that the deletion of eNOS results in increased myocardial dysfunction following ischemia-reperfusion in an isolated heart model.

Minimally invasive resection of congenital subaortic stenosis.

Fifteen consecutive patients with membranous subaortic stenosis underwent resection by a minimal-access approach through a partial upper sternotomy using a cardioscope. There were no operative deaths and no postoperative complications. Twelve patients (80%) were extubated in the operating room. The mean hospital stay was 3.1 days, and 3 patients (20%) needed blood products. Our experience demonstrates that this modified approach is a safe and effective surgical option for resection of subaortic stenosis.

The Ross operation in a Jehovah's Witness: a paradigm for heart surgery in children without transfusion.

A 3-year-old 18 kg male child of the Jehovah's Witness faith presented with severe aortic regurgitation. A successful Ross procedure was performed using a pulmonary autograft, without the use of blood or blood product transfusion. Blood conservation strategy included: (1) preoperative treatment with recombinant human erythropoietin; (2) intraoperative strategies, including technical modifications to the Ross procedure, and the prophylactic use of fibrin glue; (3) utilization of a heparin-bonded cardiopulmonary bypass circuit and assisted venous drainage; and 4) the use of prebypass phlebotomy, cell-saving device and autotransfusion. The patient was discharged home on postoperative day 7 with a hemoglobin level of 11.9.

The combination of propranolol and magnesium does not prevent postoperative atrial fibrillation.

BACKGROUND: Atrial fibrillation is a common complication of cardiovascular surgery. Beta-blockers have been shown to decrease the incidence of postoperative atrial fibrillation. However, the use of magnesium is more controversial. It was our hypothesis that adjunctive magnesium sulfate would improve the efficacy of beta-blockers alone in the prevention of postoperative atrial fibrillation. METHODS: We prospectively randomized 167 coronary artery bypass patients (mean age 61+/-10 years, 115 men) to receive propranolol alone (20 mg four times daily) or propranolol and magnesium (18 g over 24 hours). Magnesium was begun intraoperatively, and propranolol was started on admission to the intensive care unit. RESULTS: Using an intention-to-treat analysis, the incidence of postoperative atrial fibrillation was 19.5% in the propranolol-treated patients and 22.4% in propranolol + magnesium-treated patients (p = 0.65). Because combination therapy resulted in an excess of postoperative hypotension, which required withholding doses of propranolol, an on-treatment analysis was also performed. In this analysis, the incidence of atrial fibrillation was still not significantly different (18.5% in propranolol-treated patients and 10.0% in propranolol + magnesium-treated patients, p = 0.20). CONCLUSIONS: Adjunctive magnesium sulfate, in combination with propranolol, does not decrease the incidence of postoperative atrial fibrillation.

Heparin-coated cardiopulmonary bypass circuit: clinical effects in pediatric cardiac surgery.

OBJECTIVES: Heparin-coated cardiopulmonary bypass (CPB) circuits have been reported to reduce complement activation and the inflammatory response associated with CPB. We retrospectively compared patients utilizing heparin-coated perfusion circuits with those using noncoated circuits to determine the clinical effects of the different circuits in pediatric cardiac surgery. METHODS: Between July 1995 and July 1997, 203 patients weighing < 10 kg underwent cardiac surgery, 153 patients using heparin-coated bypass circuits and 50 patients using noncoated circuits. The 50 patients operated on with the noncoated circuit (Group N) were matched to 100 patients operated on with coated circuits (Group H) in age, weight, and type of procedure. Urine output during bypass, blood products used after bypass, postoperative ventilation days, hospital stay, morbidity, and mortality were compared between these groups. RESULTS: Body weight, perfusion time, and procedure time were not different between the two groups. Urine output during bypass was notably greater in Group H than in Group N (11.3 +/- 10.5 mL/kg per hour vs 4.8 +/- 3.1 mL/kg per hour, respectively, p < 0.0001). Postoperative mechanical ventilation markedly decreased in Group H (Group H vs N = 2.8 +/- 2.7 days vs 5.1 +/- 7.5 days, respectively, p < 0.05). Red blood cell usage, hospital stay, morbidity, and mortality were not statistically different, although there was a tendency toward decreased transfusion of red cell and platelets in Group H (Group H vs N = 61.2 +/- 121.1 mL/kg vs 102.0 +/- 176.7 mL/kg, respectively, in red cell, p = 0.15; and Group H vs N = 7.9 +/- 13.7 mL/kg vs 13.2 +/- 24.5 mL/kg, respectively, in platelets, p = 0.16). CONCLUSIONS: Patients operated on with the use of heparin-coated circuits had increased urine output during bypass and required less time postoperatively on the ventilator. These results suggest a reduction in the acute inflammatory response, capillary leakage, and overall systemic edema. We now routinely use coated circuits on all pediatric pump cases.

Nonanticoagulant heparin prevents coronary endothelial dysfunction after brief ischemia-reperfusion injury in the dog.

BACKGROUND: Coronary endothelial dysfunction after brief ischemia-reperfusion (IR) remains a clinical problem. We investigated the role of heparin and N-acetylheparin, a nonanticoagulant heparin derivative, in modulating coronary endothelial function after IR injury, with an emphasis on defining the role of the nitric oxide (NO)-cGMP pathway in the heparin-mediated effect. METHODS AND RESULTS: Male mongrel dogs were surgically instrumented, and the effects of both bovine heparin and N-acetylheparin on coronary endothelial vasomotor function, expressed as percent change from baseline flow after acetylcholine challenge, were studied after 15 minutes of regional ischemia of the left anterior descending artery (LAD) followed by 120 minutes of reperfusion. In dogs treated with placebo (saline), coronary vasomotor function was significantly (P

Heparin preserves nitric oxide activity in coronary endothelium during ischemia-reperfusion injury.

BACKGROUND: Brief episodes of ischemia followed by reperfusion adversely affect endothelial vasomotor function. We hypothesized that heparin may impart a protective effect on the coronary endothelium during ischemia-reperfusion injury possibly via the nitric oxide pathway. METHODS: Eighteen anesthetized dogs were randomly assigned to one of two treatment groups: saline solution or bovine heparin (6.0 mg x kg intravenously). A flow probe and cannula were placed in the left anterior descending artery. Functional recovery of the coronary endothelium was assessed after 15 minutes of ischemia and during 120 minutes of reperfusion after acetylcholine and nitroprusside challenge. In a separate group (n = 10), nitric oxide activity was measured as nitrate/nitrite levels and cyclic guanosine monophosphate levels in the left anterior descending artery. RESULTS: Control dogs displayed a significant decrease in percent change of left anterior descending artery flow at 15, 30, and 60 minutes of reperfusion (67%+/-8%, 76% +/-11%, and 84%+/-8%) when compared with preischemic values (108+/-6; p < 0.01). Heparinized dogs, however, showed preservation of coronary endothelial function after acetylcholine challenge throughout reperfusion. Heparin-treated dogs also displayed a significant increase in nitrate/nitrite levels during reperfusion (37.3+/-4.1 micromol/L) when compared with the saline group (24.3+/-0.8 micromol/L; p < 0.03). Left anterior descending artery levels of cyclic guanosine monophosphate were also significantly increased after heparin administration (3.0+/-0.3 pmol/mg) when compared with ischemia-reperfusion alone (0.7+/-0.1 pmol/mg; p < 0.03). CONCLUSIONS: Heparin preserves the vasoregulatory function of the coronary endothelium during brief episodes of ischemia-reperfusion injury, in part, via the nitric oxide pathway. Administration of heparin may have important therapeutic implications in the prevention of coronary endothelial dysfunction associated with reperfusion injury.

Early discharge of patients with new-onset atrial fibrillation after cardiovascular surgery.

BACKGROUND: Atrial fibrillation is one of the most frequent complications after cardiovascular surgery. It may result in thromboembolic events, hemodynamic deterioration, and an increased length and cost of hospitalization. METHODS: We retrospectively studied 504 consecutive adult patients undergoing cardiovascular surgery to determine whether patients with new-onset postoperative atrial fibrillation could be safely discharged in atrial fibrillation after ventricular rate had been controlled and anticoagulation initiated. RESULTS: Postoperative atrial fibrillation occurred in 79 (16.2%) of the 487 survivors. Of these patients, 67 were discharged in sinus rhythm, whereas the remaining 12 were discharged in atrial fibrillation. Patients discharged in atrial fibrillation tended to be older, have higher Parsonnet risk scores, and have an increased incidence of valvular heart surgery. Despite this result, this cohort had a shorter length of hospital stay (7.3+/-2.0 days vs 10.9+/-9.3 days, p = 0.006), decreased hospital costs ($14,188+/-$2635 vs $23,016+/-$21,963, p = 0.002), and decreased hospital charges ($37,878+/-$7420 vs $58,289+/-$50,980, p = 0.003) compared with patients with atrial fibrillation discharged in sinus rhythm. In the 12 persons discharged home in atrial fibrillation, no repeat hospitalizations, bleeding complications, or thromboembolic events occurred. CONCLUSION: A strategy of early discharge of patients with persistent postoperative atrial fibrillation appears promising and deserves prospective testing on a larger scale.

Heparin and nonanticoagulant heparin preserve regional myocardial contractility after ischemia-reperfusion injury: role of nitric oxide.

OBJECTIVES: These studies were performed to determine the effect of heparin and nonanticoagulant heparin on myocardial function after ischemia-reperfusion and to further evaluate the role that the nitric oxide-cyclic guanosine monophosphate pathway plays in mediating the effect of heparin. METHODS: Fifteen dogs were subjected to 15 minutes ischemia followed by 120 minutes reperfusion and pretreated with either saline solution, bovine heparin (6.0 mg/kg intravenously), or N-acetyl heparin (6.0 mg/kg intravenously), a heparin derivative without anticoagulant properties. The left anterior descending artery was occluded for 15 minutes and regional systolic shortening, a unitless measure of myocardial contractility, assessed during reperfusion. To evaluate the role of nitric oxide, the inhibitor N(omega)-nitro-L-arginine, 1.5 mg/kg intracoronary, was given before heparin administration. Myocardial levels of cyclic guanosine monophosphate, the second messenger of nitric oxide, were also measured in the N-acetyl heparin group using radioimmunoassay. RESULTS: Regional systolic shortening was significantly decreased in the saline group during 60 and 120 minutes compared with before ischemia (9.2 +/- 1.0 and 9.0 +/- 0.9 vs 12.2 +/- 1.2, p < or = 0.0003). Heparin and N-acetyl heparin-treated dogs, however, showed preservation of systolic shortening throughout reperfusion. Administration of nitro-L-arginine significantly attenuated the protective effect of heparin (9.2 +/- 1.2 vs 12.7 +/- 1.1, p < or = 0.0001) and N-acetyl heparin (9.3 +/- 0.3 vs 12.8 +/- 0.4, p < or = 0.0001) during 120 minutes reperfusion. Myocardial levels of cyclic guanosine monophosphate were also significantly increased in the N-acetyl heparin group compared with saline (199.1 +/- 7.1 vs 103.5 +/- 4.5 pmol/mg, p < or = 0.0001). CONCLUSIONS: Heparin preserves myocardial contractility after ischemia-reperfusion independent of its anticoagulant properties. Furthermore, the protective effects of heparin during ischemia-reperfusion are mediated, at least in part, through a nitric oxide-cyclic guanosine monophosphate pathway.

Non-anticoagulant heparin increases endothelial nitric oxide synthase activity: role of inhibitory guanine nucleotide proteins.

Heparin, which is widely used clinically, has recently been shown to have specific properties affecting the vascular endothelium. We hypothesized that heparin stimulates endothelial nitric oxide synthase (eNOS) activity by a mechanism independent of its anticoagulant properties and dependent on an inhibitory guanine nucleotide regulatory protein (Gi). We determined the effect of both heparin and N-acetyl heparin (Non-Hep), a heparin derivative without anticoagulant properties, on eNOS activity in cultured bovine aortic endothelial cells and on endothelium-dependent relaxation in isolated vascular rings. The eNOS activity was determined by measuring both citrulline and nitric oxide (NO) metabolite formation. Heparin and Non-Hep dose-dependently increased basal eNOS activity (ED50 1.0 microgram/ml or 0.15 U/ml), an effect that was significantly inhibited by pertussis toxin (100 ng/ml), a Gi-protein inhibitor. Agonist-stimulated (acetylcholine, 10 microM) eNOS activity was potentiated following pre-treatment with both heparin and Non-Hep and reversed by pertussis toxin. Heparin and Non-Hep induced a dose-dependent relaxation in preconstricted thoracic aortic rings, an effect that was significantly inhibited by pertussis toxin, endothelial inactivation (following treatment with sodium deoxycholate) and NG-nitro-L-arginine-methyl ester (L-NAME). We conclude that heparin and non-anticoagulant heparin induce endothelium-dependent relaxation following activation of eNOS by a mechanism involving a Gi-protein. Administration of heparin derivatives without anticoagulant properties may have therapeutic implications for the preservation of eNOS in conditions characterized by endothelial dysfunction.

Development of an enterprise-wide clinical data repository: merging multiple legacy databases.

We describe the development of a clinical data repository whose core consists of four years of inpatient administrative and billing data from the mainframe legacy systems of the University of Virginia Health System (UVAHS). To these data we have linked a cardiac surgery clinical database and our physician billing data (inpatient and outpatient). Other databases will be merged in the future. A relational database management system (Sybase) running on a dedicated IBM RS/6000 minicomputer was employed to assemble 2.5 Gigabytes of core data describing approximately 100,000 hospital admissions over the four year period. To enable convenient data queries, the system has been equipped with a custom-built WWW user interface, which generates Structured Query Language (SQL) automatically. We illustrate the rapid reporting capabilities of the resulting system with reference to patients undergoing coronary artery bypass graft surgery (CABG). We conclude that this information system: a) constitutes a convenient and low-cost method to increase data availability across the UVAHS; b) provides clinicians with a tool for surveillance of patient care and outcomes; c) forms the core of a comprehensive database from which clinical research may proceed; d) provides a flexible interface empowering a wide variety of clinical departments to share and enrich their own clinical data.

Initial postoperative serum lactate levels predict survival in children after open heart surgery.

OBJECTIVE: To evaluate the relationship between postoperative serum lactate levels and outcome in children undergoing open heart surgery. DESIGN: Prospective, noninterventional study. SETTING: Pediatric intensive care unit (PICU) of a university hospital. PATIENTS: 41 nonconsecutive children who had had cardiopulmonary bypass for repair of congenital heart disease. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: Serum lactate levels were measured on admission to the PICU immediately after open heart surgery. Lactate levels were correlated with bypass and cross clamp times, estimated intraoperative blood loss, lowest temperature on bypass, admission Pediatric Risk of Mortality score, anion gap, and measures of postoperative morbidity. Mean lactate levels on admission to the PICU were 6.86 +/- 0.79 mmol/l for nonsurvivors (n = 7) and 2.38 +/- 0.13 mmol/l for survivors (n = 34) (p < 0.0001), and 4.87 +/- 0.7 mmol/l and 2.35 +/- 0.19 mmol/l, for patients with (n = 11) and without (n = 30) multiple organ system failure, respectively (p < 0.0001). Admission lactate levels correlated with all measurements of postoperative morbidity. A serum lactate level of greater than 4.2 mmol/l had a positive predictive value of 100% and a negative predictive value of 97% for postoperative death. CONCLUSIONS: Initial postoperative serum lactate levels after pediatric open heart surgery may be predictive of outcome. Lactate levels are also higher in patients who go on to develop multiple organ system failure. Elevated postoperative lactate levels may reflect intraoperative tissue hypoperfusion, and measures aimed at increasing oxygen delivery, with normalization of lactate, may improve patient outcome.