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Biomedical subjects

G K Danielson

Publications and source records attributed to G K Danielson.

At least 55 records · Page 3Linked to original sources

Partial anomalous pulmonary venous connection: diagnosis by transesophageal echocardiography.

OBJECTIVE: This study sought to demonstrate that with proper technique, identification of the normal and abnormal pulmonary venous connection can be made with confidence using transesophageal echocardiography (TEE). BACKGROUND: Partial anomalous pulmonary venous connection (PAPVC) is an uncommon congenital anomaly whose diagnosis has classically been made using angiography. METHODS: We performed a retrospective review of all patients of all ages with PAPVC diagnosed at the Mayo Clinic who had undergone TEE because of either right ventricular volume overload or suspected intracardiac shunting by transthoracic echocardiography or intraoperatively. RESULTS: A total of 66 PAPVCs were detected in 43 patients (1.5/patient); in 2 additional patients, TEE suggested, but did not diagnose, PAPVCs. Shortness of breath was the most common presenting symptom (42.2%), followed by heart murmur and supraventricular tachycardia. Right-sided anomalous veins were identified in 35 patients (81.4%), left-sided in 7 (16.3%) and bilateral in 1 (2.3%). There was a single anomalous connecting vein in 23 patients (53.5%), two in 18 (41.9%), three in 1 (2.3%) and four in 1 (2.3%). The connecting site was the superior vena cava (SVC) in 39 veins (59.1%), right atrial-SVC junction in 6 (9.1%), right atrium in 8 (12.1%), inferior vena cava in 1 (1.5%) and the coronary sinus in 2 (3.0%). Ten anomalous left pulmonary veins were connected by a vertical vein to the innominate vein (15.1%). Sinus venosus atrial septal defect (ASD) was the most common associated anomaly in 22 patients (49%), followed by ostium secundum ASD in 6 and patent foramen ovale in 4. Fifteen patients had an intact atrial septum. Thirty-one patients (68.8%) underwent surgical repair. PAPVC was confirmed in all patients, including the two whose TEE results were suggestive of PAPVC. All 49 PAPVCs detected by TEE preoperatively were confirmed at the time of operation. CONCLUSIONS: TEE is highly diagnostic for PAPVC and can obviate angiography. Accurate anatomic diagnosis may influence the need for medical and surgical management. TEE should be performed in patients with right ventricular volume overload when the precordial examination is inconclusive.

Adult↗

Transesophageal echocardiography: unusual case of anomalous pulmonary venous connection to the azygos vein.

Partial anomalous pulmonary venous connection, a rare congenital anomaly, most commonly involves the right lung, with one or more pulmonary veins anomalously connecting most frequently to the superior vena cava and less commonly to the right atrium or inferior vena cava. This article describes an unusual case of anomalous pulmonary venous connection of the right lung to the azygos vein in an adult. This anomaly was clearly delineated with angiography, computed tomography of the chest, and transesophageal echocardiography. The transesophageal echocardiographic features of the anomaly are described as a means to prevent further diagnostic misinterpretation.

Angiography↗

Permanent pacing in Ebstein's anomaly.

Patients with Ebstein's anomaly present unique challenges to permanent pacing due to anatomical variations and tricuspid valve replacement. We retrospectively reviewed our experience with permanent pacing in patients with Ebstein's anomaly between 1976 and 1993. We identified 401 patients with Ebstein's anomaly, of whom 15 (3.7%) required permanent pacing (1 of the 15 was implanted elsewhere). Of the 15, there were 8 females and 7 males (mean age 32 years [range 7-74]); the indications for pacing were AV block in 11 and sinus node dysfunction in 4. Eight patients were programmed with VVI and seven with DDD. All VVI patients were paced epicardially. Two patients with DDD pacemakers had transvenous atrial and ventricular leads, 4 DDD patients had transvenous atrial leads and epicardial ventricular leads, and 1 patient had both epicardial and transvenous systems. Associated surgical procedures included tricuspid valve replacement in 14 of 15, atrial septal defect repair in 10 of 15, atrioplasty in 7 of 15, prior tricuspid annuloplasty in 4 of 15, pulmonary vein dilation in 1 of 15, and conduction system ablation in 2 of 15. Patients had a mean follow-up of 35 months (range 1-168 months). Complications requiring operative intervention occurred in four patients. One patient had displacement of a transvenous ventricular lead. A second patient had an epicardial lead failure. A third patient had a nonfunctioning atrial lead that displaced across the tricuspid valve, causing severe tricuspid regurgitation. The fourth patient had multiple epicardial and endocardial leads exit block with secondary diaphragmatic stimulation. Permanent pacemakers were required in 3.7% of patients with Ebstein's anomaly, with the indication being intrinsic conduction disease in the majority of patients. Ninety-three percent of patients required tricuspid valve replacement, suggesting more severe manifestation of Ebstein's anomaly. Twenty-seven percent had complications requiring surgical intervention. Thus, permanent pacing in patients with Ebstein's anomaly can be challenging and should be approached by an experienced physician.

Adolescent↗

Diagnosis of sinus venosus atrial septal defect with transesophageal echocardiography.

BACKGROUND: Sinus venosus atrial septal defect (SVD) is underdiagnosed with transthoracic echocardiography because of its posterior (far field) location. Transesophageal echocardiography (TEE) should be ideally suited to diagnose SVD, given the proximity of the transducer to the defect. METHODS AND RESULTS: A retrospective study was undertaken that used the medical history, echocardiographic findings, and surgical data of patients identified from computer records as having the diagnosis of SVD during the period in which TEE has been in use (1987 to 1995). Twenty-five patients (14 females and 11 males; median age, 45 years; range, 10 to 75 years) with SVD had TEE between 1987 and 1995. Prior transthoracic echocardiography clearly defined the SVD in 3 of these patients, and it was suspected in another 11 on the basis of color-flow imaging. Ten patients had unexplained dilatation of the right side of the heart, which prompted TEE examination. SVD was visualized with TEE in all 25 patients and ranged in size from 1 to 3 cm. Thirty-seven right-sided anomalous pulmonary venous connections were identified in 23 patients. No left-sided anomalous pulmonary venous connections were detected. Anatomic confirmation was obtained in all 23 surgical patients. No patient required preoperative cardiac catheterization for diagnosis. CONCLUSIONS: TEE is accurate for the diagnosis of SVD and should be undertaken in any patient with unexplained dilatation of the right side of the heart. The associated pulmonary venous abnormalities can be identified with TEE. Cardiac catheterization for diagnostic purposes should not be required before surgical correction.

Adolescent↗

Extent of clinical improvement after surgical treatment of hypertrophic obstructive cardiomyopathy.

BACKGROUND: A subgroup of patients with hypertrophic obstructive cardiomyopathy remain severely symptomatic despite optimal medical therapy. Septal myectomy reduces or eliminates left ventricular outflow obstruction and produces marked symptomatic improvement. With the recent advent of alternative methods for treatment of this disorder, such as dual-chamber pacing, it is necessary to establish the risks and benefits of septal myectomy in the modern surgical era. METHODS AND RESULTS: The clinical, ECG, echocardiographic, cardiac catheterization, and surgical data were analyzed for 65 patients 20 to 70 years old with hypertrophic obstructive cardiomyopathy who had surgical treatment between 1986 and 1992. Specific symptoms and overall functional status were evaluated before surgery and at the end of the first postoperative year. Subsequent long-term clinical postoperative follow-up was also obtained. The extent of postoperative improvement was measured by the presence and severity of persistent symptoms, overall New York Heart Association (NYHA) functional class, and patients' self-perceptions of overall improvement. Of the patients, 95% were in NYHA functional class III or IV before surgery: 95% had dyspnea, 62% had angina, 63% had near-syncope, and 23% had syncope. The overall early mortality rate was 4.6%; there was no mortality among the 45 patients who underwent isolated septal myectomy. At the 1-year postoperative evaluation, 89% of survivors were in NYHA functional class I or II, and 47% believed that they had 100% improvement. Significant improvement (as defined) was seen in 67% of patients with dyspnea, 90% with angina, 86% with near-syncope, and 100% with syncope. The 5-year survival rate was 92%. CONCLUSIONS: The results of the present study reaffirm the efficacy of surgical treatment of hypertrophic obstructive cardiomyopathy in patients who are severely symptomatic despite optimal medical therapy and serve as a useful reference by which the surgical approach can be compared with new and potentially promising treatment alternatives.

Adult↗

Value of dynamic respiratory changes in left and right ventricular pressures for the diagnosis of constrictive pericarditis.

BACKGROUND: Conventional cardiac catheterization criteria for the diagnosis of constrictive pericarditis (CP) rely on equalization of intracardiac pressures and have many recognized limitations. Recently, Doppler echocardiographic methods have been used to examine dynamic respiratory changes of increased ventricular interdependence and dissociation of intrathoracic and intracardiac pressures for the diagnosis of CP. These pathophysiological features may be best delineated by cardiac catheterization. Therefore, we studied the accuracy of these dynamic respiratory changes in left ventricular and right ventricular pressure for the diagnosis of CP at cardiac catheterization. METHODS AND RESULTS: High-fidelity manometric catheters and respirometry were used to study 36 patients: 15 patients with surgically proven CP (group 1) and 21 patients with other causes of heart failure (group 2). Conventional cardiac catheterization variables used to establish the diagnosis of CP lacked sensitivity and specificity and failed to distinguish between these groups. However, the finding of discordance between right ventricular and left ventricular pressures during inspiration, a sign of increased ventricular interdependence, accurately distinguished patients in group 1 from those in group 2 (P < .05). CONCLUSIONS: Examination of dynamic respiratory changes indicating increased ventricular interdependence may be helpful in the diagnosis of CP in the cardiac catheterization laboratory.

Adult↗

Comparison of techniques for implantation of aortic valve allografts.

BACKGROUND: Various implantation techniques for allograft aortic valve replacement have evolved over the years. Our objective was to examine the effects of different implantation methods on subsequent valve performance and durability. METHODS: Between May 1985 and January 1994, 137 patients underwent allograft aortic valve replacement. The first 59 aortic valve allografts were inserted by the freehand scalloped technique with removal of the aortic sinuses, and the last 78 valves were inserted by the cylinder technique, in which the aortic sinuses and sinotubular junction were retained. The mean age of the 91 men and 46 women was 53.7 years (range, 18 to 83 years). Preoperative diagnoses were aortic stenosis (n = 57), aortic regurgitation (AR, n = 40) and aortic stenosis/AR (n = 40); 27 patients had prior aortic valve operations and 1 patient had a previous heart transplantation. Active endocarditis was present in 29 patients. Associated procedures included coronary artery bypass (n = 33), ascending aneurysm repair (n = 4), left ventricular aneurysmectomy (n = 3), repair of atrial septal defect (n = 2), mitral valve repair or replacement (n = 6), and aortic root enlargement (n = 24). Follow-up was complete in 133 patients (97%) a mean of 4.9 years (range, 1 day to 9.8 years) after allograft aortic valve replacement. RESULTS: Operative mortality was 6.5% for all patients but only 1.9% for patients without infection having isolated aortic valve replacement. Early echocardiography (mean of 8.4 days postoperatively) demonstrated no AR or mild AR and a mean gradient of 10.6 +/- 6.2 mm Hg in all patients. The cumulative risk of development of grade III or IV AR at 7 years postoperatively was 26.2% +/- 6.3% in the scallop group and 12.4% +/- 5.6% in the cylinder group (p = 0.4). Late postoperatively, transvalvular gradient by echocardiography was 13.1 +/- 9.4 mm Hg, and was similar in the two study groups. Late AR led to reoperation in 13 patients (22%) who had initial implantation with the scallop method and only 4 patients (5.4%) who had the valve inserted with the cylinder method. However, because duration of follow-up was longer for patients in the scallop group, cumulative risk of reoperation was similar at 5 years postoperatively (scallop, 13.7% [95% confidence interval, 76.7% to 95.8%]; cylinder, 11.5% [95% confidence interval, 75.5% to 99.1%]). CONCLUSIONS: The insertion of an aortic valve allograft as a cylinder, retaining the sinotubular junction, appears to result in less aortic regurgitation at 7 years postoperatively, and with additional follow-up may result in less reoperation for AR.

Adolescent↗

Hypertrophic obstructive cardiomyopathy: preoperative echocardiographic predictors of outcome after septal myectomy.

OBJECTIVES: The purpose of this study was to determine whether two-dimensional and Doppler echocardiography are predictive of clinical outcome in patients with hypertrophic obstructive cardiomyopathy who undergo septal myectomy. BACKGROUND: Surgical myectomy provides excellent relief of symptoms in most patients with hypertrophic obstructive cardiomyopathy who are severely symptomatic despite medical therapy. There is a subset of patients who will remain symptomatic even after operation. Because comprehensive two-dimensional and Doppler echocardiography can define the range of anatomic and associated pathophysiologic abnormalities, it was hypothesized that preoperative echocardiographic variables may be predictive of clinical outcome after septal myectomy. METHODS: The clinical, electrocardiographic (ECG), echocardiographic and surgical data of 47 adult patients with hypertrophic cardiomyopathy who underwent isolated septal myectomy from 1986 to 1992 were analyzed. Specific symptoms were evaluated both preoperatively and at 1 year postoperatively. Electrocardiography and echocardiography were performed preoperatively and postoperatively. The ECG and echocardiographic variables were analyzed to determine whether any were predictive of residual symptoms 1 year postoperatively. RESULTS: The mean [+/-SD] age of the patients was 47 +/- 15 years. All were New York Heart Association functional class III or IV. Dyspnea was present in all 47 patients and was severe in 70%. Most patients experienced symptomatic improvement at 1 year; dyspnea persisted in 26 patients (55%). The preoperative echocardiographic variables of asymmetric hypertrophy, severe systolic anterior motion of the mitral leaflet(s) and prolonged isovolumetric relaxation time were independent predictors of mild or no residual dyspnea postoperatively. CONCLUSIONS: This initial study shows that the preoperative echocardiographic variables of asymmetric hypertrophy, severe systolic anterior motion of the mitral leaflet(s) and prolonged isovolumetric relaxation time can identify patients who are most likely to benefit from septal myectomy.

Adult↗

Improved early morbidity and mortality after Fontan operation: the Mayo Clinic experience, 1987 to 1992.

OBJECTIVES: This study sought to evaluate changes in early morbidity and mortality as well as predictors of outcome in our most recent 339 patients undergoing modified Fontan operations. BACKGROUND: The Fontan operation is the preferred definitive palliation for patients with functional single ventricles. Previously reported early mortality rates after Fontan operation have been substantial. METHODS: Records of 339 consecutive patients who had a Fontan operation at the Mayo Clinic between 1987 and 1992 (recent cohort) were reviewed. This cohort was compared with the previous 500 patients who had Fontan operations performed between 1973 and 1986 (early cohort). RESULTS: Recently, overall early mortality after Fontan has decreased significantly compared with that for the early cohort (from 16% to 9%, p = 0.002). This decline occurred despite increased anatomic complexity of patients. Short-term posthospital survival has also improved significantly in recent patients. One-year survival improved to 88% from 79%, and 5-year survival to 81% from 73% (p = 0.006). Patients with common atrioventricular valves and those who took daily preoperative diuretic medication or had either postoperative renal failure or elevated postbypass right atrial pressure were at increased risk for early mortality. Young age was not found to be a risk factor for early mortality. Early mortality for patients with heterotaxia decreased dramatically: recent 30-day mortality was 15% compared with 41% in the early heterotaxy cohort. CONCLUSIONS: Many factors may have contributed to decreased early mortality after Fontan. Improved patient selection, younger age at time of operation, refinements in surgical techniques and postoperative management may all have had important roles. Proposed technical modifications of the Fontan operation must be evaluated in light of these improved results.

Age Factors↗

Hypertrophic obstructive cardiomyopathy in pediatric patients: results of surgical treatment.

Between April 1975 and May 1995, 25 pediatric patients on one hospital service underwent extended left ventricular septal myectomy because of hypertrophic obstructive cardiomyopathy. Ages ranged from 2 months to 20 years (mean, 11.2 years). Seventeen patients had moderate to severe mitral valve insufficiency. Medical therapy had failed in all patients and one patient had undergone dual-chamber pacemaker implantation without improvement. Left ventricular outflow tract gradients ranged from 50 to 154 mm Hg (mean, 99.9 +/- 25.2). Concomitant cardiac procedures included mitral valve repair (n = 2), automatic implantable cardioverter defibrillator implantation (n = 1), and closure of atrial septal defect (n = 1). Intraoperative premyectomy left ventricular outflow tract gradients ranged from 20 to 117 mm Hg (mean, 60.4 + 26.2) and postmyectomy gradients ranged from 0 to 20 mm Hg (mean, 6.6 +/- 5.9). Postmyectomy mitral insufficiency was reduced to a regurgitant fraction of 0% to 12%, and no patient required mitral valve replacement. One patient required a pacemaker because of complete heart block; on subsequent follow-up, normal sinus rhythm had returned. There was no early mortality and no instance of aortic or mitral valve injury or ventricular septal defect. Follow-up ranged from 10 months to 20 years (mean, 6.4 years). There were no late deaths. Left ventricular outflow tract gradients by echocardiography were a mean of 14.2 mm Hg with a median of 5.0 mm Hg. All patients had normal sinus rhythm. Reoperation because of recurrent left ventricular outflow tract obstruction was necessary in two patients at 3.2 years and 12.4 years after initial myectomy, respectively. All patients but one have New York Heart Association class I or II function. We conclude that extended septal myectomy is a safe and effective means of relieving cardiac symptoms and left ventricular outflow tract obstruction in pediatric patients with severe hypertrophic obstructive cardiomyopathy unresponsive to medical management, and late survivorship compares favorably with the natural history of the disease.

Adolescent↗

Protein-losing enteropathy after the Fontan operation.

Patients were observed after the Fontan operation to determine the frequency and severity of protein-losing enteropathy. A total of 427 patients who survived for 30 days after the Fontan operation, performed between 1973 and January 1987, were analyzed and, thus far, protein-losing enteropathy has developed in 47 of 427. The cumulative risk for the development of protein-losing enteropathy by 10 years was 13.4% among 30-day survivors, and 5-year survival after the diagnosis was 46%. Hemodynamic studies done coincident with the diagnosis of protein-losing enteropathy have shown increased systemic venous pressure, decreased cardiac index, increased pulmonary vascular resistance, and increased ventricular end-diastolic pressure. Medical management of protein-losing enteropathy was only partially successful. Statistical analysis has shown that factors related to protein-losing enteropathy were ventricular anatomy, increased preoperative ventricular end-diastolic pressure, longer operative bypass time, increased length of hospital stay, and postoperative renal failure. This study suggests that scrupulous selection of cases for the Fontan operation is mandatory and that certain perioperative factors may predispose to this serious complication of the Fontan procedure.

Age Factors↗

Risk of thromboembolism with the aortic Carpentier-Edwards bioprosthesis.

Porcine bioprostheses provide an excellent alternative to mechanical prostheses for heart valve replacement in patients unable to comply with systemic anticoagulation and in the elderly. Long-term results of this prosthesis, however, demonstrated identical survival and parallel event-free status, albeit at a lower rate than the mechanical valves. Some discrepancy exists as to the need for and duration of systemic anticoagulation in the bioprosthesis, and some evidence exists to contraindicate anticoagulation due to a higher late mortality rate in patients with an aortic bioprosthesis. The records of 561 patients having the Carpentier-Edwards bioprosthesis in the aortic position as an isolated valve procedure were reviewed. The overall rate of bioprosthetic failure events was low (0.23%/patient year) and the survival (5 year, 74.8 +/- 2.4%; 10 year, 52.9 +/- 4.9%) and event-free statistics (5 year, 67.9 +/- 2.6%; 10 year, 42.4 +/- 5.1%) were excellent. No gender difference was present. A vulnerable period for neurologic events was identified by hazard function whereby the incidence of stroke was high; these were increased in the patient variables of compromised ejection fraction (0.54; p < or = 0.003), older age (< or = 73 years; p < or = 0.02), and preoperative atrial fibrillation or paced rhythm (p < or = 0.01). This pattern was similar for both transient ischemic events and strokes and rapidly decreased over the first few months of the first year and the first few years of the 12-year follow-up. These patients were not routinely anticoagulated.(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗

Repair of congenital and acquired pulmonary vein stenosis.

BACKGROUND: Congenital pulmonary vein stenosis is a rare cause of obstruction of pulmonary venous blood flow with a high mortality. Acquired pulmonary vein stenosis is an equally serious condition. METHODS: Eight patients (age range, 3 months to 43 years; median age, 1.5 years) underwent surgical relief of pulmonary vein stenosis. Two had congenital pulmonary vein stenosis, 5 had pulmonary vein stenosis that was acquired after surgical treatment of total anomalous pulmonary venous connection, and 1 had pulmonary vein stenosis associated with idiopathic mediastinal fibrosis and calcification. RESULTS: One infant died 2 months after correction of acquired pulmonary vein stenosis. At follow-up extending to 16 years (median follow-up, 6.5 years), 6 patients are in New York Heart Association functional class I, and 1 patient is in class II. CONCLUSIONS: In view of the dismal natural history of untreated pulmonary vein stenosis, prompt surgical relief of the stenosis may be a rewarding undertaking.

Adolescent↗

Partial atrioventricular canal defect: long-term follow-up after initial repair in patients > or = 40 years old.

OBJECTIVES: This study was undertaken to determine the results of repair of partial atrioventricular (AV) canal in patients > or = 40 years old. BACKGROUND: Although postoperative outcomes in younger patients have been well documented, the fate of older patients with repaired partial AV canal is less clear. METHODS: From 1958 to 1990, 31 patients 40 to 71 years old (mean age 51) had repair of partial AV canal. Twenty-three patients had repair of the cleft mitral valve; two had mitral valve replacements; and six needed no mitral valve operation. RESULTS: Early mortality was 6%. One patient was lost to follow-up. Nine of the early survivors are known to have died. There is a small but significant development over the long term of atrial arrhythmias, complete heart block, subaortic stenosis, recurrent mitral regurgitation and, rarely, mitral stenosis. Three of the 28 patients available for follow-up had mitral valve reoperation and subaortic stenosis developed in 2. Nineteen patients were alive in 1991 (mean follow-up 14 years). Seven patients were in New York Heart Association functional class I, eight were in class II, and four were in class III. Fifteen of the 19 patients reported sustained postoperative improvement. CONCLUSIONS: Patients > or = 40 years old can have partial AV canal repair with low risk. Long-term survival is good, with subjective improvement in symptoms. Late complications occur but are uncommon, suggesting that long-term follow-up is warranted.

Adult↗

High risk of thromboemboli early after bioprosthetic cardiac valve replacement.

OBJECTIVES: We studied the rate of thromboembolism in patients undergoing bioprosthetic replacement of the aortic or mitral valve, or both, at serial intervals after operation and the effects of anticoagulant or antiplatelet treatment and risk factors. BACKGROUND: Thromboembolism appears to occur early after operation, but the incidence, timing and risk factors for thromboembolism and the role, timing, adequacy, effectiveness, duration and risk of anticoagulation and antiplatelet agents are uncertain. METHODS: The rate of thromboembolism was studied at three time intervals after operation (1 to 10, 11 to 90 and > 90 days) in 816 patients who underwent bioprosthetic replacement of the aortic or mitral valve, or both, at the Mayo Clinic from January 1975 to December 1982. The effect of antithrombotic therapy (warfarin, aspirin or dipyridamole, alone or in combination) was evaluated. RESULTS: Median follow-up of surviving patients was 8.6 years. The rate of thromboembolism (%/year) decreased significantly (p < 0.01) at each time interval after operation (1 to 10, 11 to 90 and > 90 days) for mitral valve replacement (55%, 10% and 2.4%/year, respectively) and over the first time interval for aortic valve replacement (41%, 3.6% and 1.9%/year, respectively). During the first 10 days, 52% to 70% of prothrombin time ratios were low (< 1.5 x control). Patients with mitral valve replacement who received anticoagulation had a lower rate of thromboembolism for the entire follow-up period (2.5%/year with vs. 3.9%/year without anticoagulation, p = 0.05). Of 112 patients with a first thromboembolic episode, permanent disability occurred in 38% and death in 4%. Risk factors for emboli were lack of anticoagulation, mitral valve location, history of thromboembolism and increasing age. Only 10% of aortic, 44% of mitral and 17% of double valve recipients had anticoagulation at the time of an event. Patients with bleeding episodes (2.3%/year) were older and usually underwent anticoagulation. Blood transfusions were required in 60 of 111 patients (1.2%/year), and 13 patients (0.3%/year) died. CONCLUSIONS: Thromboembolic risk was especially high for aortic and mitral valve replacement for 90 days after operation, and overall was increased with lack of anticoagulation, mitral valve location, previous thromboembolism and increasing age. Anticoagulation reduced thromboemboli and appears to be indicated in all patients as early as possible for 3 months and thereafter in those with risk factors, but needs prospective testing.

Adult↗

Results of an autologous tissue reconstruction for replacement of obstructed extracardiac conduits.

Between May 1983 and March 1, 1995, 50 patients had replacement of an obstructed pulmonary ventricle-pulmonary artery conduit with an autologous tissue reconstruction in which a prosthetic roof was placed over the fibrous tissue bed of the explanted conduit. The roof was constructed with xenograft pericardium (most recently) (n = 42), homograft dura mater (n = 5), or Dacron fabric (n = 3). Patient ages ranged from 5 to 34 years (median 16 years). The explanted conduits were Hancock conduits (n = 33), Tascon conduits (n = 6), homograft (n = 4), Dacron tube (n = 3), and others (n = 4). Preoperative maximum systolic gradients ranged from 44 to 144 mm Hg (median 78 mm Hg). Thirty-seven concomitant cardiac procedures were done in 29 patients. When a valve was necessary (n = 15), it was possible to place a large-sized valve in the autologous tissue reconstructions (range 22 to 29 mm, median 26 mm). Cardiopulmonary bypass times ranged from 34 to 223 minutes (median 84 minutes), and aortic crossclamp times ranged from 0 (in 32 patients) to 109 minutes (median 0 minutes). Intraoperative postrepair peak systolic gradients from pulmonary ventricle to pulmonary artery ranged from 0 to 33 mm Hg (median 13 mm Hg). There was one early death (2%) in a patient who had additional cardiac procedures. Follow-up was complete in all patients and ranged from 1 month to 11.8 years (median 7.5 years). There were two sudden late deaths: conduits in both were known to be free from obstruction. Forty-four of the 47 surviving patients had evaluation of the gradient by echocardiography or cardiac catheterization 1 month to 11 years (median 7 years) after operation. The gradients ranged from 5 to 45 mm Hg (median 20 mm Hg). None of the conduits developed an obstructive peel, valve obstruction, or valve incompetence. At 10 years, the freedom from reoperation for conduit obstruction was 100%, and freedom from reoperation for any cause was 81%. This technique simplifies conduit replacement, allows for a generous-sized outflow tract, has a low risk, and yields late results that appear superior to those of cryopreserved homografts or other types of extracardiac conduits.

Adolescent↗

The modified Fontan operation. An analysis of risk factors for early postoperative death or takedown in 702 consecutive patients from one institution.

To better understand risk factors associated with early postoperative death or failure, we reviewed our entire experience with 702 consecutive patients who had the modified Fontan operation at the Mayo Clinic between October 1973 and December 1989. The event rate for takedown of repair or death during the initial hospitalization or within 30 days of the operation was 14.8% (successful takedown of the repair, n = 6; death, n = 98). To identify variables associated with early death or Fontan takedown, we analyzed 33 clinical and hemodynamic variables in a univariate and multivariate manner. On the basis of a stepwise logistic discriminant analysis, patients who were younger and operated on before 1980 with a higher preoperative pulmonary artery mean pressure, asplenia, higher intraoperative (after Fontan operation) right atrial pressure, longer aortic crossclamp time, and pulmonary artery ligation were more likely to have the outcome event of interest (p values < 0.05). A new variable, corrected pulmonary artery pressure (that is, mean preoperative pulmonary artery pressure divided by the ratio of pulmonary to systemic flow if the ratio of pulmonary to systemic flow is greater than 1.0), was significantly associated with the outcome event univariately (p = 0.002), but was no more predictive than the preoperative pulmonary artery mean pressure. Variables less predictive of the outcome event in this analysis included multiple prior operations, polysplenia syndrome, complex anatomy other than asplenia syndrome, and systemic atrioventricular valve regurgitation. These results represent the largest single-institution review of the Fontan operation and suggest that some anatomic and hemodynamic variables previously predictive of poor early outcome have been nullified by current operative methods.

Child↗