Biomedical subjects

N D Bridges

Publications and source records attributed to N D Bridges.

51 records · Page 3Linked to original sources

PubMed1993

Enlarged bronchial arteries after early repair of transposition of the great arteries.

OBJECTIVES: This study was undertaken to define the incidence of enlarged bronchial arteries after early surgical repair of transposition of the great arteries by the arterial switch operation, and to report the results of catheter-directed therapy in five patients. BACKGROUND: Pathologic and angiographic studies have demonstrated enlarged bronchial arteries in patients with transposition of the great arteries. METHODS: A subjective 4-point scale was used to grade postoperative angiograms performed in 119 patients at our institution between January 1983 and December 1991. Grades 0 and 1 were designated if there was no opacification of the pulmonary arteries or veins, whereas grades 2 and 3 were assigned if there was such opacification. The median age at repair was 8 days (range 1 day to 13 months) and the median age at catheterization was 11.2 months (range 3.6 to 58.5). An intact ventricular septum was present in 84 (71%) of 119 patients. RESULTS: Significantly increased bronchial flow (grade 2 or 3) was present in 55 (46%) of 119 patients. Age at repair, age at catheterization and interval between repair and catheterization were not associated with significantly increased bronchial flow; however, an intact ventricular septum was weakly associated with increased flow (p = 0.04). Coil embolization was performed in five patients with complete occlusion of the vessels and no significant complications. CONCLUSIONS: Abnormally enlarged bronchial arteries are frequently identified at postoperative catheterization despite early repair and may explain continuous murmurs or persistent cardiomegaly in patients with otherwise normal noninvasive findings. When clinically indicated, catheter-directed therapy can be performed with good results.

Bronchial Arteries↗

PubMed1993

Prevalence and risk factors for aortopulmonary collateral vessels after Fontan and bidirectional Glenn procedures.

OBJECTIVES: The purpose of this study was to evaluate the prevalence of and risk factors for aortopulmonary collateral vessels in patients who have undergone a bidirectional Glenn or Fontan procedure, or both. BACKGROUND: Aortopulmonary collateral vessels are frequently observed angiographically in patients after a bidirectional Glenn or Fontan procedure. These vessels may provide a source of pulmonary blood flow competitive with anterograde cavopulmonary flow. METHODS: We performed a retrospective study of all patients (n = 196) who underwent catheterization between January 1, 1988 and February 29, 1992 (n = 268) after bidirectional Glenn or Fontan procedures and reviewed clinical, hemodynamic and angiographic phone data. RESULTS: Collateral vessels were diagnosed in 36% of patients. Patients who underwent the bidirectional Glenn procedure were more likely to have collateral vessels than patients who underwent the Fontan procedure (65% vs. 30%, respectively; p < 0.0001). Patients with a history of a Blalock-Taussig shunt were more likely to have collateral vessels than those without (50% vs. 24%, respectively; p = 0.0006). Discretely identifiable collateral vessels were measurable in 54 (20%) of 268 catheterizations. The total estimated cross-sectional area of these vessels averaged 10.7 +/- 7.2 mm2. In patients who underwent the bidirectional Glenn procedure, a step-up in oxygen saturation from the superior vena cava to the distal pulmonary arteries or an upper lobe filling defect, or both, on pulmonary angiogram predicted total estimated cross-sectional area of collateral vessels. Most collateral vessels originated from the internal mammary arteries (34%) and the thyrocervical trunks (22%). Only 9% of collateral vessels arising from the brachiocephalic vessels were visualized by aortogram; the remainder required selective angiography in the subclavian or more distal arteries. CONCLUSIONS: Aortopulmonary collateral vessels are common after bidirectional Glenn and Fontan procedures. Aortograms often fail to diagnose their presence. The left to right shunt carried by these vessels is associated with a step-up in oxygen saturation in the distal pulmonary arteries. The clinical significance and indications for closure of these vessels are not known.

Adolescent↗

PubMed1993

Devices for transcatheter closure of intracardiac defects.

Transcatheter closure of intracardiac defects is an investigational procedure that is in use at a number of centers in North America and Europe. A radiologist should be able to recognize these devices on a chest radiograph, understand their actual physical appearance, and be able to recognize their expected location. This essay summarizes the indications for, technical aspects of, and radiologic appearance of these devices.

Cardiac Catheterization↗

PubMed1993

Intraoperative device closure of ventricular septal defects.

BACKGROUND: Surgical repair of muscular ventricular septal defects (VSDs) has been associated with significant morbidity and mortality when the defects are multiple, associated with complex cardiac lesions, or requiring left ventriculotomy. Transcatheter VSD closure may be difficult in patients weighing less than 7 kg or those with limited vascular access. We attempted intraoperative device closure of muscular VSDs during surgical repair of associated lesions. METHODS AND RESULTS: We considered intraoperative umbrella closure in 10 patients, 8 with additional complex heart lesions. "Swiss cheese" defects were present in 4. Median patient age was 4.7 months. Device closure was not attempted in 1 patient due to an inadequate septal rim. Nine umbrellas, 12 to 40 mm in diameter, were positioned to straddle the septum in all 9 patients. There were 3 early deaths, 2 in patients who were moribund preoperatively. The third was due to severe ventricular dysfunction. Among the 6 survivors, 3 had a Qp:Qs < or = 2 and right ventricular or pulmonary artery pressure less than half systemic. These patients had no further intervention. The other 3 had a Qp:Qs > 2. One died unexpectedly 5 weeks after cardiac surgery. The other 2 had subsequent closure of residual VSDs. All 5 survivors are well at follow-up of 8 to 25 months. CONCLUSIONS: Intraoperative umbrella VSD closure appears less successful than VSD closure in the catheterization laboratory. In selected patients, particularly very small infants, intraoperative device placement may be advantageous. Completeness of closure is difficult to assess intraoperatively.

Cardiac Catheterization↗

PubMed1993

Transcatheter closure of atrial and ventricular septal defects.

The clamshell double umbrella (Bard Clamshell Septal Umbrella, USCI Division, C. R. Bard, Billerica, MA) was developed to allow closure of septal defects, both atrial and ventricular. The device and delivery system and the techniques for implanting the device in atrial and ventricular defects are described in detail. Although fractures of the arms supporting the umbrellas in some patients have lead to modification of the device, the early experience in clinical trails are encouraging.

Cardiac Catheterization↗

PubMed1992

Effect of baffle fenestration on outcome of the modified Fontan operation.

BACKGROUND: The "fenestrated Fontan" (surgical baffle fenestration followed by transcatheter test occlusion and permanent closure after postoperative recovery) was adopted in an effort to reduce perioperative mortality and morbidity. This study assesses the effect of baffle fenestration on outcome. METHODS AND RESULTS: Patients having a modified Fontan operation with a cavocaval baffle and cavopulmonary anastomosis were retrospectively selected for study. Those with baffle fenestration (n = 91) were compared with those without baffle fenestration (n = 56) with respect to preoperative risk factors, age, anatomy, surgical date, and presence or absence of a previous bidirectional cavopulmonary anastomosis. Outcome variables were failure (death or take-down) and duration of postoperative pleural effusions and hospitalization. Survival and clinical status after hospital discharge were ascertained. The two groups did not appear to differ with respect to age or anatomic diagnosis. Patients having baffle fenestration were at significantly greater preoperative risk by univariate and multivariate analysis (p < 0.01). Operative failure was low in both groups (11% without and 7% with baffle fenestration, p = NS). Durations of pleural effusions and hospitalization were significantly shorter with baffle fenestration (p < 0.01). Neither date of surgery nor a previous bidirectional cavopulmonary anastomosis appeared to contribute to improved outcome. Patients with baffle fenestration had lower postoperative systemic venous pressure (p < 0.01). There were no late deaths. Functional status in both groups is good (82% in New York Heart Association class I). CONCLUSIONS: Baffle fenestration is associated with low mortality, significantly less pleural effusion, and significantly shorter hospitalization among high-risk patients having a modified Fontan operation.

Cardiac Surgical Procedures↗

PubMed1992

Transcatheter closure of patent foramen ovale after presumed paradoxical embolism.

BACKGROUND: Many have proposed a relation between presence of a patent foramen ovale, with or without atrial septal aneurysm, and cryptogenic stroke. The effect of foramen ovale closure on the risk for subsequent strokes is unknown. METHODS AND RESULTS: Transcatheter closure of a patent foramen ovale was undertaken in 36 patients with known right-to-left atrial shunting and presumed paradoxical emboli (31 strokes, 25 transient neurological events, four systemic arterial emboli, and two brain abscesses). Individual patients had between one and four such events. None had a left heart or carotid source of embolism; 31 of 35 had no known risk factors for stroke. Events occurred in 12 patients while they were taking warfarin. At cardiac catheterization, patent foramina ovalia were significantly larger than predicted for age in 67% of the patients. Implantation of a double-umbrella device in the patent foramen ovale was achieved in all without serious procedural complications. Of 34 who have returned for follow-up, one has a residual atrial communication that may be clinically important, five had trivial leaks, and 28 have complete closure. There have been no strokes during a mean follow-up of 8.4 months. CONCLUSIONS: Transcatheter closure of a patent foramen ovale can be accomplished with little morbidity and may reduce the risk of recurrence. Further investigations directed toward identifying the population at risk and assessing the effect of intervention are warranted.

Actuarial Analysis↗

PubMed1992

Transcatheter closure of atrial septal defects: hemodynamic complications and anesthetic management.

Transcatheter closure of atrial septal defects using a double-umbrella (clamshell) device can now be performed during an overnight hospital stay with little morbidity and no mortality. The initial 2-yr experience with anesthetic care for the procedure was collected and subsequently analyzed. Primary anesthetic care was given in 118 cases and urgent anesthetic intervention was required in another four cases. Anesthesia with spontaneous ventilation in patients with unprotected airways using intravenous ketamine and midazolam (average cumulative doses 1.4 and 0.17 mg.kg-1.h-1, respectively) was used in 93 cases (77%); mean maximum PaCO2 value was 41 +/- 6 mm Hg. In 29 patients (23%) tracheal intubation and muscle paralysis were used to facilitate control of airway and ventilation. Anesthetic-related complications occurred in three patients: ventilatory compromise developed in two patients in the spontaneous ventilation group and one patient experienced awareness during endotracheal anesthesia with paralysis. Procedural complications that altered anesthetic management were more frequent, including embolization of the clamshell device requiring surgical retrieval in two of six embolizations, intracardiac air embolization (four cases), tricuspid regurgitation (one case), device malplacement requiring late operation (one case), and transient brachial plexus injury (three cases). Anesthesia for transcatheter atrial septal defect closure allows precise device placement, prompt control of hemodynamic complications, and transesophageal echocardiographic monitoring of device placement. Although general anesthesia with spontaneous ventilation using ketamine and midazolam was usually safe and effective, tracheal intubation for control of airway and ventilation was sometimes necessary for safety and for optimal operating conditions. Familiarity with transcatheter closure techniques and close communication with the catheterization team is essential to minimize and treat associated complications.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1992

The fenestrated Fontan procedure.

In 90 patients with characteristics placing them at increased risk for a Fontan operation, a fenestration was created in the atrial baffle at the time of the Fontan repair. The rational was to allow a right to left shunt which would maintain cardiac output and limit right atrial pressure in the presence of conditions which limit pulmonary blood flow. Early mortality was 4/90 (4%), with an additional two patients having the Fontan repair taken down to a bidirectional cavopulmonary anastomosis. Postoperative right atrial pressures were low (average 13 mm Hg), as was the incidence of prolonged pleural effusions (13%). At short-term (average 13 months) follow-up, 77% of patients have had closure of the fenestration, and 92% are in New York Heart Association Class I. We conclude that baffle fenestration with subsequent transcatheter closure results in decreased mortality and morbidity among high risk patients undergoing a Fontan repair, and that the high functional level at short-term follow-up justifies continued aggressive management of such patients.

Adolescent↗

PubMed1992

Factors associated with marked reduction in mortality for Fontan operations in patients with single ventricle.

The Fontan operation was originally employed for patients with tricuspid atresia, but its application has been extended to those with a variety of complex defects in which there is functionally only a single ventricular chamber. The outcome of 225 modified Fontan operations carried out between 1984 and 1990 at the Children's Hospital, Boston, for patients with defects other than tricuspid atresia was reviewed. Overall 30 patients (13.3%) had failure of this operation (death or takedown). Results improved significantly during the period of the study, with failure rates of 6.5% (2 of 31) and 3.4% (2 of 59) in the last 2 years of the review. Multivariate analysis showed that pulmonary artery distortion, pulmonary artery pressure, age less than 3 years, use of a nonoxygenated glucose K+ cardioplegic solution, and cardiopulmonary bypass time greater than 180 minutes were associated with worse outcome, while "favorable" atrioventricular valve anatomy (non-left atrioventricular valve stenosis/atresia or common atrioventricular valve) and age greater than 9 years were associated with improved outcome. Excluding cardiopulmonary bypass time from the multivariate analysis, the technique of atrial partitioning for patients with left atrioventricular valve atresia/stenosis became the most important variable, followed by the others noted in the initial multivariate analysis except for age greater than 9 years. In the last 2 years of the study 31.1% of patients were less than 3 years of age. During the period of the study there was no significant decline in preoperative risk factors. These results show that modified Fontan operations can be carried out with a high likelihood of success in properly selected patients with complex defects in whom there is functionally a single ventricle.

Age Factors↗

PubMed1991

Transcatheter closure of a large patent ductus arteriosus with the clamshell septal umbrella.

In 14 patients undergoing transcatheter closure of a large (greater than 4 mm diameter) patent ductus arteriosus, occlusion was attempted with use of the Bard Clamshell septal umbrella. Patient age ranged from 0.7 to 30.4 years. Isolated patent ductus arteriosus was present in 11 patients; 3 had additional congenital heart lesions. Moderate or severe pulmonary hypertension was present in four patients. The diameter of the patent ductus arteriosus ranged from 4.5 to 14 mm, as determined by contrast injection through an 11F sheath or by balloon sizing; it appeared larger by this method than by the standard angiographic method. All 14 patent ductus arteriosi were successfully closed. Prior embolization of a Rashkind umbrella was the reason for using a Clamshell device in three patients; one additional embolization of a Clamshell device occurred. All errant devices were retrieved at cardiac catheterization, without associated hemodynamic instability. No other complications occurred. Among the 14 patients, 11 had complete ductal closure by Doppler color flow mapping at last follow-up and 3 had trivial residual flow. All four patients having associated complex lesions or pulmonary hypertension, or both, had symptomatic improvement after the procedure, although one child (with Shone's anomaly) died 3 months later. The Clamshell device provides stable and effective closure of a large patent ductus arteriosus, and allows transcatheter closure to be offered to some patients who were previously considered unsuitable for this procedure.

Adolescent↗

PubMed1991

Preoperative transcatheter closure of congenital muscular ventricular septal defects.

BACKGROUND: Surgical repair of muscular ventricular septal defects, particularly those associated with complex heart lesions carries a higher risk of reoperation and death than the repair of membranous defects. Closing a muscular defect through an incision in the systemic ventricle may cause late ventricular dysfunction. In a collaborative approach to this problem, we undertook preoperative transcatheter closure of muscular ventricular septal defects remote from the atrioventricular and semilunar valves, followed by the surgical repair of associated conditions. METHODS: In 12 patients selected jointly by a cardiologist and a cardiac surgeon, we attempted preoperative transcatheter umbrella closure of 21 defects. Half the patients had associated complex heart lesions; the others had had pulmonary-artery banding to reduce the amount of left-to-right shunting. Half had severe ventricular septal deficiency. RESULTS: All 21 defects were successfully closed without major complications. Subsequent cardiac surgery for associated conditions in 11 of the 12 patients resulted in a mean pulmonary-to-systemic flow ratio of 1.1, indicating minimal residual left-to-right shunting; 1 patient awaited surgical repair. No deaths, reoperations, or late complications have occurred after a follow-up of 7 to 20 months. CONCLUSIONS: A collaborative approach using transcatheter closure followed by the surgical repair of associated cardiac lesions may decrease rates of operative mortality, reoperation, and left ventricular dysfunction in patients with muscular ventricular septal defects.

Adult↗

PubMed1990

Baffle fenestration with subsequent transcatheter closure. Modification of the Fontan operation for patients at increased risk.

Ventricular dysfunction, elevated pulmonary vascular resistance, and residual distal pulmonary artery distortion contribute to early mortality after a Fontan operation; they may be transient or reversible. A baffle fenestration, allowing right-to-left shunting, maintains cardiac output and limits right atrial pressure. A baffle fenestration was surgically created at the time of a modified Fontan repair in 20 consecutive patients. Risk factors included pulmonary artery pressure of 18 mm Hg or more, end-diastolic pressure of 12 mm Hg or more, valvar regurgitation, pulmonary artery distortion, pulmonary vascular resistance of 2 Woods' units or more, ventricular outflow obstruction, and complex anatomy. Nineteen of 20 patients survived. After the operation, mean arterial oxygen saturation was 86%, mean right atrial pressure was 15 mm Hg, and mean duration of pleural effusions was 6 days. Twelve of 19 survivors tolerated early test occlusion and had permanent transcatheter umbrella closure. Four patients failed early test occlusion, with a significant decrease in venous O2 saturation and a rise in central venous pressure, due to ventricular dysfunction, pulmonary artery distortion, or aortopulmonary collaterals. Three of four had successful late closure of the fenestration after correction of these abnormalities.

Cardiac Catheterization↗

PubMed1990

Bidirectional cavopulmonary anastomosis as interim palliation for high-risk Fontan candidates. Early results.

Thirty-eight patients considered to be at increased risk for a Fontan repair underwent bidirectional cavopulmonary anastomosis. Twenty-one of the 38 had concurrent pulmonary artery reconstruction. Fontan risk factors included pulmonary artery distortion, elevated pulmonary artery resistance (greater than 2 Woods units) and/or pulmonary artery pressure (mean, greater than 18 mm Hg), atrioventricular valve regurgitation, systemic ventricular dysfunction, complex venous anatomy, and subaortic obstruction. There were no deaths, either early or late. Median arterial oxygen saturation increased from 79% to 84% (p less than 0.01). Median hospital stay was 8 days. No patient had pleural effusions after 7 days. Three patients had significant surgical complications. Five patients had inadequate relief of cyanosis; three of these had venous collaterals and two had severe ventricular dysfunction; the latter two patients subsequently had strokes. One of the patients with persistent cyanosis required a systemic-to-pulmonary artery shunt. We conclude that a bidirectional cavopulmonary shunt, with pulmonary artery reconstruction when indicated, provides adequate relief of cyanosis in most patients with single-ventricle lesions who are considered to be at increased risk for a Fontan repair. Relief of ventricular volume overload and pulmonary artery distortion may improve Fontan candidacy. Also, patients with persistent cyanosis after bidirectional cavopulmonary anastomosis should be catheterized for location and occlusion of venous collaterals. Further follow-up is necessary to determine the place of bidirectional cavopulmonary anastomosis in the management of patients at increased risk for a Fontan repair.

Anastomosis, Surgical↗

PubMed1989

Pulmonary artery index. A nonpredictor of operative survival in patients undergoing modified Fontan repair.

The importance of pulmonary artery size and the value of a standardized pulmonary artery index (PAI) in predicting outcome after Fontan's repair have previously been reported and questioned. We retrospectively reviewed 29 patients undergoing modified Fontan repair at The Children's Hospital of Philadelphia to examine the relation between preoperative PAI (determined echocardiographically) and operative mortality. Twenty-four of these 29 patients underwent pulmonary artery augmentation at the time of Fontan repair. PAIs ranged from 48 to 541 mm2/m2. Operative mortality was 21%. PAI ranged from 68 to 233 mm2/m2 in nonsurvivors and from 48 to 541 mm2/m2 in survivors. There was no statistically significant difference in PAI between survivors and nonsurvivors; the lowest PAI associated with survival (48 mm2/m2) was one fourth of the lowest PAI value previously reported. There was a trend, not statistically significant, toward increased survival in those with larger PAIs. We conclude that patients should not be excluded from consideration for Fontan's repair solely on the basis of pulmonary artery size.

Child↗