Comparison of intra-ocular pressure changes with liquid or flat applanation interfaces in a femtosecond laser platform.

Cataract surgery is the most common surgical procedure and femtosecond laser assisted cataract surgery (FLACS) has gained increased popularity. FLACS requires the application of a suction device to stabilize the laser head and focus the laser beam accurately. This may cause a significant escalation in intra-ocular pressure (IOP), which poses potential risks for patients undergoing cataract surgery. In this study we aimed to assess the effect of the Ziemer LDV Z8 femtosecond cataract machine on IOP. We demonstrated through a porcine model that IOP was significantly higher with a flat interface but could be abrogated by reducing surgical compression and vacuum. Pressure was lower with a liquid interface, and further altering angulation of the laser arm could reduce the IOP to 36 mmHg. A pilot series in patients showed comparable pressure rises with the porcine model (30 mmHg). These strategies may improve the safety profile in patients vulnerable to high pressure when employing FLACS with the Ziemer LDV Z8.

Ocular involvement in patients with posttransplant lymphoproliferative disorder.

OBJECTIVES: To describe ocular disease in 3 patients with posttransplant lymphoproliferative disorder (PTLD) and to identify the frequency of such ocular involvement. METHODS: Medical record reviews. Using Kaplan-Meier analysis, we calculated the frequency of ocular involvement among pediatric patients with systemic PTLD after liver transplantation. RESULTS: Each patient had bilateral anterior chamber cells. Biopsy of an iris nodule from a patient who had undergone cardiac transplantation confirmed the diagnosis of PTLD, but no signs of systemic PTLD were found. The other 2 patients had systemic PTLD after liver transplantation; 1 presented with iris nodules in both eyes and a subretinal mass in the left eye, while the other had bilateral anterior chamber cells only. Ocular signs improved slowly after reduction of immunosuppressive drug therapy. Ophthalmological examinations were performed on 22 of 25 pediatric patients with PTLD after liver transplantation; 2 had ocular disease. Kaplan-Meier analysis indicated a 20% risk of ocular involvement at 3 years after development of PTLD (95% confidence intervals, 0%-50%). CONCLUSIONS: Posttransplant lymphoproliferative disorder should be considered in the differential diagnosis of uveitis after organ transplantation. Anterior chamber cells and iris nodules are the most common ocular signs, but the posterior segment can be involved. Ocular involvement can occur without evidence of systemic disease and can be asymptomatic. Reduction of immunosuppressive drug therapy is an appropriate treatment.

Staged surgical approach to neonates with aortic obstruction and single-ventricle physiology.

BACKGROUND: The surgical management of neonatal systemic outflow obstruction and complex single ventricle pathology is variable. METHODS: In 15 neonates (12 boys and 3 girls) with complex forms of single-ventricle pathology and aortic coarctation or interruption, an initial strategy of banding the pulmonary artery and repair of the obstruction from a left thoracotomy was undertaken. RESULTS: The median age at operation was 6 days (range 2 to 33 days) and the median weight was 3.3 kg (range 2 to 4.6 kg). There were no early deaths and one late death after the initial surgical palliation. Of the 14 survivors, 8 have undergone a bidirectional cavopulmonary anastomosis. The median age for bidirectional Glenn was 9.75 months (range 3.5 to 26 months). Seven infants have required Damus-Kaye-Stansel reconstruction for subaortic obstruction (one early death). The median age of the Damus-Kaye-Stansel procedure was 4 months (range 3 weeks to 9 months). Thirteen of 15 patients (87%) are alive and 6 have proceeded to a Fontan operation (median follow-up 68 months). A single failing Fontan required takedown to bidirectional Glenn and central shunt. CONCLUSIONS: Our experience suggests that this high-risk subgroup of neonates with aortic obstruction and single-ventricle pathophysiology is safely managed by initial pulmonary artery banding palliation and repair of aortic obstruction. This strategy, careful surveillance, and early relief of subaortic stenosis can maintain acceptable anatomy and hemodynamics for later bidirectional Glenn and Fontan procedures.

Damus-Stansel-Kaye procedure: current indications and results.

Between October 1983 and August 1991, 29 consecutive Damus-Stansel-Kaye procedures were performed. Indications for operation included restrictive bulboventricular foramen or subaortic stenosis associated with complex univentricular congenital heart disease (25) and Taussig-Bing heart, subaortic stenosis, or both associated with complex biventricular congenital heart disease (4). Twelve patients underwent concurrent Fontan procedures. Average age at operation was 39.8 months (range, 1 to 132 months). Average outflow tract gradient was 28 mm Hg (range, dynamic to 80 mm Hg). Of the 29 patients, 23 were male and 6 were female. There were three early deaths (10%), two in patients who had a concurrent Fontan procedure. Although there was a trend toward lower age and higher outflow tract gradients in nonsurvivors, these and other factors were not statistically significant predictors of death. Actuarial freedom from cardiac-related death was 88% at 5 years (n = 7). In a mean follow-up of 3.5 years (range, 0.1 to 7.7 years), 3 patients have required reoperation (10%), 2 for aortic valve insufficiency (5 days and 2.75 years) and 1 for a gradient across the anastomosis (5.75 years). Actuarial freedom from reoperation related to a failed Damus-Stansel-Kaye procedure was 90% at 4 years and 75% at 6 years (n = 7).

Modified Fontan procedure in patients less than 4 years of age.

BACKGROUND: Initial experience with the modified Fontan procedure in patients < 4 years of age has met with variable success, with early reports showing a high mortality. More recently, improved results with the modified Fontan procedure in younger patients have been achieved. Important advantages of an early Fontan include protection of the pulmonary vascular bed and preservation of ventricular function by reduction in ventricular volume overload and chronic hypoxemia. METHODS AND RESULTS: From 1982 through May 1991, 90 patients < 4 years of age underwent a modified Fontan procedure. The average age was 29 months (range, 7-48 months), and 30 patients were < 2 years of age. Diagnoses included tricuspid atresia in 36, single ventricle in 45, pulmonary atresia intact septum in seven, and hypoplastic left heart syndrome in two patients. An adjustable ASD was placed in 21. Early mortality was 8.9% (eight of 90), which is only slightly higher than our overall Fontan early mortality of 7.4% in 242 patients. The early mortality in the 30 patients < 2 years of age was 6.7% (two of 30). In a mean follow-up of 38 months (range, 7-89 months), there have been three late deaths (3.7%), and one patient has undergone cardiac transplantation. CONCLUSIONS: Early Fontan should be undertaken in patients > 6 months old who present with increasing cyanosis provided good hemodynamics are present. A modified Fontan procedure can be performed safely with good clinical results in patients < 4 years old.

Partial biventricular repair of pulmonary atresia with intact ventricular septum. Use of an adjustable atrial septal defect.

BACKGROUND: Repair of pulmonary atresia with intact ventricular septum (PA-IVS) is one of the more challenging problems in congenital heart surgery. The hypertrophied but hypoplastic right ventricle is suddenly presented with an increased volume load as the right-to-left shunt is abolished by closure of the atrial septal defect (ASD) as part of definitive repair. We have proposed that a restrictive, adjustable ASD that allows a controlled right-to-left shunt may prevent excessive venous hypertension and allow adequate left-sided filling after biventricular repair of PA-IVS. METHODS AND RESULTS: From 1982 through 1991, 39 patients presented for definitive repair of PA-IVS. Nineteen of these patients were thought to be suitable candidates for biventricular repair, and the other 20 underwent a modified Fontan procedure. An adjustable ASD was used in 12 of the 19 patients undergoing biventricular repair. Mean age was 24 months (age range, 5-66 months). Two patients had their ASD snared closed in the operating room after coming off bypass. In the other 10 patients, closure of the ASD could not be tolerated at the time of surgery as evidenced by elevation of right atrial pressures by > 15 mm Hg and decreased blood pressure when closure was attempted. Seven patients had their open ASDs closed by the snare device, and one patient had his ASD narrowed in the early postoperative period. One patient underwent delayed closure 16 months after surgery. There was one hospital death. CONCLUSIONS: The snare-controlled adjustable ASD allows partial biventricular repair of PA-IVS, reducing the risk of low cardiac output and severe venous hypertension in the postoperative period.

Factors influencing survival of patients with heterotaxy syndrome undergoing the Fontan procedure.

OBJECTIVES: This study was undertaken to determine those factors that may influence survival in patients with heterotaxy syndrome undergoing the Fontan procedure. BACKGROUND: The Fontan procedure remains the preferred palliative procedure for patients with heterotaxy syndrome. Although the mortality rate has improved for patients without this syndrome undergoing the Fontan procedure, it remains high for patients with heterotaxy syndrome. METHODS: The medical records of 20 consecutive pediatric patients with asplenia (n = 12) and polysplenia (n = 8) who underwent the Fontan procedure between January 1, 1986 and December 31, 1990 were reviewed. Anatomic and hemodynamic data were collected, as well as data on types of surgical palliative procedures and on outcome of the Fontan procedure. RESULTS: There were two early and two late deaths for a total mortality rate of 20% in the patients with heterotaxy syndrome, as compared with 8.5% for the patients without this syndrome who underwent the Fontan procedure during the same time period. Factors that significantly increased the risk of the Fontan procedure in these patients were 1) preoperative findings of greater than mild atrioventricular valve regurgitation, b) hypoplastic pulmonary arteries, and c) mean pulmonary artery pressure greater than or equal to 15 mm Hg after 6 months of age. Systemic and pulmonary venous anomalies coupled with single-ventricle anatomy were not significant risk factors for determining a poor outcome of the Fontan procedure. CONCLUSIONS: This study suggests that the outcome of the Fontan procedure in patients with heterotaxy syndrome may be improved by early protection of the pulmonary vascular bed, despite the existence of other cardiac anomalies.

Repair of conotruncal abnormalities with the use of the valved conduit: improved early and midterm results with the cryopreserved homograft.

Repair of complex cardiac lesions has been facilitated by the availability of valved conduits to reestablish right ventricular to pulmonary artery continuity. From 1977 to June 1991, 148 patients underwent repair with insertion of a conduit. Their mean age was 6.6 years (11 days to 45 years). The diagnosis was transposition of the great arteries with ventricular septal defect and left ventricular outflow tract obstruction in 51, truncus arteriosus in 36, pulmonary atresia with ventricular septal defect in 25, tetralogy of Fallot in 19, double-outlet right ventricle in 10, pulmonary atresia with intact ventricular septum in 6 and atrioventricular canal with pulmonary atresia in 1. A Dacron porcine-valved conduit was used in 37, a homograft conduit in 106 and a nonvalved conduit in 5. There were 13 early deaths overall (8.8%); 8 (22%) of the early deaths occurred in the 37 patients who received a Dacron graft, 4 (3.8%) occurred in the 106 patients who received a homograft and 1 occurred in a patient with a nonvalved Gore-Tex conduit. An additional patient underwent orthotopic heart transplantation in the early postoperative period. In 117 patients operated on from January 1985 to June 1991 the early mortality rate was 2.6% (3 of 117). Among 28 patients receiving a Dacron porcine-valved graft there were two late deaths (7.1%) after a mean follow-up interval of 93 months, and 8 patients required reoperation for conduit obstruction. Among 102 homograft recipients there were two late deaths (1.9%).(ABSTRACT TRUNCATED AT 250 WORDS)

Partial Fontan: advantages of an adjustable interatrial communication.

Systemic venous hypertension after the Fontan procedure is a major cause of mortality and morbidity, accounting for 11 of 16 deaths in our series of 228 Fontan procedures. A partial Fontan with a residual atrial septal defect (ASD) would allow controlled right-to-left shunting to reduce venous pressure and improve cardiac output while maintaining a reduced but acceptable arterial oxygen saturation. This allows complete or graded closure of the ASD after the discontinuation of cardiopulmonary bypass in the operating room or at any time in the postoperative period by exposing the snare under local anesthesia. From 1987 to 1990, 36 patients undergoing the modified Fontan procedure had placement of an adjustable interatrial communication. Indications for placement of an adjustable ASD included increased pulmonary artery pressures, increased pulmonary vascular resistance, reactive airway disease, previously increased or unknown pulmonary vascular resistance, small pulmonary arteries, and borderline ventricular function. Fourteen patients had the adjustable ASD closed at the time of operation, 8 patients underwent narrowing, and 12 underwent closure of the ASD in the postoperative period. Eight patients were discharged with the ASD partially open, and 2 patients underwent delayed closure. The partial Fontan with an adjustable ASD may increase the safety of the Fontan procedure for high-risk groups such as those with increased pulmonary vascular resistance, pulmonary hypertension, and impaired left ventricular function and for infants, who tolerate venous hypertension poorly. The ability to adjust the ASD in stages depending on the hemodynamic response increases flexibility and safety.

Results of total cavopulmonary connection in the treatment of patients with a functional single ventricle.

Total cavopulmonary connection was proposed as a modification of the Fontan procedure that might have greater benefits than previous methods. To assess this procedure we reviewed case histories of 38 patients (aged 17 months to 30 years) who underwent Fontan procedures with cavopulmonary anastomoses between January 1987 and December 1989. The group included 32 patients with univentricular heart, 2 with pulmonary atresia and intact ventricular septum, 3 with tricuspid atresia, and 1 with hypoplastic left heart syndrome. One or more previous palliative procedures were performed in 34 patients, including 19 systemic-pulmonary shunts, 16 pulmonary artery bandings, 7 atrial septectomies/septostomies, 7 Glenn shunts, and 1 patent ductus arteriosus ligation. Preoperative hemodynamics showed a pulmonary artery pressure of 12 mm Hg (range 6 to 22 mm Hg), pulmonary-systemic flow ratio of 1.6 (range 0.37 to 3.0), left ventricular end-diastolic pressure 9 mm Hg (range 3 to 15 mm Hg), and systemic arterial oxygen saturation of 82% (range 67% to 94%). Concomitant with cavopulmonary connection, 13 patients underwent additional procedures, including 9 atrioventricular valve annuloplasties, 4 Damus-Stansel-Kaye procedures, and 2 resections of subaortic membranes. Modifying the Fontan procedure in this fashion was particularly useful in the management of 2 patients with pulmonary atresia and intact ventricular septum who had right ventricular-dependent coronary blood flow. Cavopulmonary anastomosis and atrial septectomy were performed in both patients, with resultant inflow of oxygenated blood to the right ventricle and coronary arteries. Excellent postoperative results were noted in each. Postextubation hemodynamics for the entire group included a mean right atrial pressure of 13 mm Hg (range 11 to 17 mm Hg), a mean left atrial pressure of 6 mm Hg (range 3 to 12 mm Hg), and a room air oxygen saturation of 96% (range 92% to 98%). Seven patients had pleural effusions, 3 required postoperative pacemaker placement, and 2 required reoperation for tamponade. A venous assist device was required in one patient on the second postoperative day, but the patient was weaned successfully within 24 hours. One early death (2.6%) occurred in a patient who had intractable ventricular fibrillation 2 days after operation. There was one late cardiac death (2.7%) caused by ventricular failure and one late noncardiac death. These results demonstrate that total cavopulmonary connection provides excellent early definitive treatment, with low morbidity and mortality, for a variety of complex congenital heart lesions.

Total cavopulmonary anastomosis versus conventional modified Fontan procedure.

The total cavopulmonary anastomosis, lateral tunnel Fontan, has been advocated as a preferred method for Fontan type repair. From 1987 to July 1990, 39 patients underwent total cavopulmonary anastomoses (group 1) and 39 patients underwent modified Fontan procedures (group 2); patients receiving adjustable atrial septal defects were excluded. Diagnoses in group 1 included tricuspid atresia in 5 patients, single ventricle in 32, and pulmonary atresia and intact ventricular septum in 2. Diagnoses in group 2 included tricuspid atresia in 20, single ventricle in 17, hypoplastic left heart syndrome in 1, and pulmonary atresia and intact ventricular septum in 1. There were no significant differences in age, weight, cross-clamp time, duration of inotropic support, postoperative effusions, or hospital stay between the two groups. Early mortality in group 1 was 7.7% (3/39) and in group 2, 2.6% (1/39). There was no difference in the incidence of early dysrhythmias or early pacemaker placement. Late mortality was 2.8% in group 1 and 8% in group 2 with a mean follow-up of 18 and 25 months, respectively. Follow-up in group 1 revealed 33 patients in normal sinus rhythm and 1 patient with episodes of supraventricular tachycardia; no additional patients have required pacemakers. Follow-up in group 2 revealed 27 patients in normal sinus rhythm and supraventricular tachycardia in 4 patients; 5 additional patients have required pacemaker placement. There is no apparent difference in early outcome between the total cavopulmonary anastomosis and the conventional modified Fontan. However, there appears to be an increased incidence of late dysrhythmias and the need for pacemaker placement in the conventional modified Fontan group compared with the lateral tunnel group.

Hemodynamic responses to isolated increments in heart rate by atrial pacing after a Fontan procedure.

The physiologic role of the right ventricle has long been a subject of interest to physiologists. The Fontan operation provides a human model for studying the circulation in series devoid of a subpulmonic right ventricle. The hemodynamic response to isotonic exercise in this setting has been established, and differs appreciably from normal. However, the physiologic response to an increase in heart rate (atrial pacing) as an isolated variable has not been examined and compared to atrial pacing in hearts with two concordant subarterial ventricles. Accordingly, we compared the supine bicycle exercise response to rate-equivalent right atrial pacing in nine patients after atriopulmonary anastomoses (the Fontan operation) for single ventricle or tricuspid atresia. Cardiac index increased 77% with exercise (rest 2.6 L/min/m2; exercise 4.6 L/min/m2) but decreased 12% with atrial pacing (rest 2.5 L/min/m2; pacing 2.2 L/min/m2). Pulmonary arterial oxygen saturation declined significantly during exercise (rest 68%; exercise 31%) and during atrial pacing (control 72%; pacing 64%). The mean increment in pulmonary arterial pressure was 1.3 times greater with exercise (rest 14 mm Hg; exercise 20 mm Hg) than with pacing (control 12 mm Hg; pacing 16 mm Hg). Peak systemic arterial systolic pressure increased 14% with exercise but was unchanged by pacing. Systemic and pulmonary vascular resistances fell with exercise but changed insignificantly during atrial pacing. Stroke volume rose slightly with exercise but fell significantly with pacing.(ABSTRACT TRUNCATED AT 250 WORDS)

Results of the Senning procedure in infants with simple and complex transposition of the great arteries.

Because of interest in the arterial switch operation, recent experience with the Senning operation in patients with simple and complex transposition of the great arteries (TGA) was examined. Between 1982 and 1985, 35 patients with simple TGA (group I) and 10 patients with complex TGA (group II) underwent a Senning operation. Mean duration of follow-up was 14 months for group I and 24 months for group II. In group I, 1 patient died early and no patient died late; infrequently, right ventricular dysfunction, tricuspid regurgitation, baffle obstruction or arrhythmias occurred. In group II, no patient died early and 3 died late. In addition, many patients required prolonged digoxin therapy. Because the arterial switch operation has a high early mortality risk and an undetermined long-term morbidity and mortality risk, the Senning operation (or other venous switch operations) is considered the preferred surgical approach for simple TGA. In contrast, an arterial switch operation is performed in patients with complex TGA (without subpulmonic obstruction). Comparison of the early and late morbidity and mortality of the arterial vs the venous switch operation may be helpful in selecting the appropriate surgical approach to complex TGA.

Effect of Ca2+ antagonists on mechanical function in the neonatal heart.

The effect of verapamil and diltiazem on mechanical function was studied in the isolated arterially perfused neonatal and adult rabbit heart. The negative inotropic effect of these drugs in the newborn was significantly greater than in the adult. At concentrations 10(-7) M of verapamil and 10(-6) M of diltiazem, resting tension was significantly increased in the newborn, but not in the adult. In both age groups, verapamil and diltiazem inhibited the positive inotropy of staircase, but did not alter the inotropic effect of hyperosmolarity (116 mM mannitol). The positive inotropy of paired electrical stimulation was eliminated by these drugs in the newborn, but not in the adult. These data suggest that the neonatal heart as compared with the adult heart is more dependent on transsarcolemmal calcium influx for contraction and transsarcolemmal calcium efflux for relaxation.

Treatment of congestive heart failure by altering loading conditions of the heart.

We have not emphasized the traditional approaches to the treatment of congestive heart failure, because there is abundant literature detailing the importance of rest and comfort for the patient, reduction of solute load, and administration of digitalis and diuretics. Instead, we have sought to emphasize the therapeutic interventions that are aimed at changing the mechanical loading conditions of the heart. Treatment expectations must be viewed within an age- or maturity-dependent framework. Thus, when a preterm or full-term newborn infant requires cardiocirculatory support, diminished cardiac reserve limits the benefits derived from diverse treatment methods. This unique fragility of the developing heart and circulation places a premium on the astute manipulation of all of the factors that determine optimum cardiovascular adaptation to stress. Beyond infancy, although cardiovascular reserve increases, it remains imperative to modify therapy by using cardioactive drugs that deal specifically with the separate mechanical and contractile variables to assure optimum survival.

New concepts and drugs in the treatment of congestive heart failure.

This article seeks to make clear the basic differences in the treatment of heart failure between therapeutic maneuvers that are aimed at improving the mechanical loading conditions of the heart and those that are aimed at augmenting the fundamental contractile or inotropic state of the myocardium. Emphasis is placed on recognizing that treatment expectations must be viewed within an age- or maturity-dependent framework, since a diminished margin of cardiocirculatory reserve exists in the smallest and youngest patients that limits the extent of benefit that may be derived from diverse treatment approaches.

Experience with the Fontan procedure.

From 1975 to the present, 45 patients have undergone modifications of the Fontan procedure for complex congenital heart disease. There were 30 males and 15 females ranging in age from 2 to 38 years (mean 13 years). Primary diagnoses were tricuspid atresia in 19, univentricular heart in 24, and pulmonary atresia with intact ventricular septum in two. Right atrial-pulmonary arterial connections were performed in 32 patients, 11 with conduits (seven with valves and four without) and 21 by direct anastomosis with patch augmentation. Right atrial-right ventricular connections were made in 13 patients, six with valved conduits and seven without conduits. Follow-up ranged from 0.1 to 9 years, with a mean of 2.3 years. There were three early deaths (less than 30 days) (7%) and two late deaths (5%) in this series, all in patients with a univentricular heart. The late deaths were both related to venous hypertension. A venous assist device was used in eight patients in the immediate postoperative period and was effective in improving cardiac output and reducing fluid accumulation. Postoperative Doppler flow studies in 15 patients revealed biphasic pulmonary artery flow in all without distinction between the type of connection or the presence of a valve. Cardiac catheterization was performed in 16 patients a mean of 14 months postoperatively (range 1 to 42 months) and revealed a reduced cardiac index at rest. Exercise testing in eight patients demonstrated a marked rise in right atrial pressure with a reduced rise in the cardiac index, even in those without functional limitations. With a mean follow-up of 2.3 years, 78% of patients were in New York Heart Association Class I, 17% in Class II, and 5% in Class III. We conclude that the Fontan procedure is an excellent operation in carefully selected patients with tricuspid atresia and other forms of complex congenital heart disease.

Caffeine effect on myocardial mechanical function in the neonatal rabbit heart.

The effects of 20 mM caffeine on myocardial mechanical function were studied in isolated, arterially perfused cardiac preparations of newborn and adult rabbits. Caffeine caused a significant increase in the maximal rate of tension development in the adult (141% of control) but not in the newborn (111%). The resting tension increased significantly in both age groups. However, the increase in the adult (245% of control) was also significantly greater than in the newborn (132%). At the points of maximum effect, caffeine perfusion in the newborn resulted in a decrease in the maximal rate of relaxation (29% of control) and an increase in the half relaxation time (144% of control) that were significantly greater than they were in the adult (41% and 103%, respectively). These data show distinct age-related differences in the effects of caffeine on myocardial mechanical function. These differences may be due to maturational changes that occur in the sarcoplasmic reticulum and T tubule system of the rabbit heart. However, maturational changes in the activity of phosphodiesterase and/or the sympathetic nervous system may play a role.