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Biomedical subjects

R A Jonas

Publications and source records attributed to R A Jonas.

At least 163 records · Page 9Linked to original sources
PubMed1992

Factors associated with choreoathetosis after cardiopulmonary bypass in children with congenital heart disease.

BACKGROUND: Choreoathetosis (CHO) after congenital heart surgery has been described since 1960. Risk factors and patient outcome have not been well defined. METHODS AND RESULTS: As our complexity of cases increased and management of pH on cardiopulmonary bypass (CPB) evolved, we noted the appearance of CHO among patients beginning in 1986. We reviewed the hospital course and follow-up of all 19 affected children, including eight younger patients (median age, 4.3 months) who developed a mild transient form of CHO, all of whom survived and had complete resolution of CHO; seven of these eight patients had deep hypothermic circulatory arrest (DHCA). Eleven older patients (median age, 16.8 months) developed severe persistent CHO; 11 had DHCA, 10 were cyanotic, seven had anatomic pulmonary atresia, and three others were physiologically analogous with a systemic to pulmonary artery shunt-dependent circulation. Five of six patients who had pertinent preoperative angiography had systemic to pulmonary collateral vessels arising from the head and neck arteries. Mortality in severe patients was 36% (four of 11); the seven survivors showed improvement, but only one had a normal neurological examination after 60 months of follow-up. When severe CHO patients were compared with 17 age- and diagnosis-matched patients without neurological complications, no differences were found in CPB or DHCA times, arterial blood gases, or hematocrits. Time from onset of CPB to onset of DHCA (time to shutoff) was shorter in the severe persistent CHO group than for comparison patients (22 +/- 7 versus 40 +/- 29 minutes, p = 0.053). CONCLUSIONS: Factors that may be associated with the development of severe persistent CHO include 1) age beyond early infancy, 2) cyanotic heart disease with systemic to pulmonary collaterals, particularly those arising from the head and neck vessels, and 3) the duration of the cooling period used in conjunction with deep hypothermic circulatory arrest. We advocate earlier reparative surgery, precise preoperative diagnosis and preoperative or intraoperative control of systemic to pulmonary artery collaterals, and further study of pH effects during CPB on development of CHO.

Athetosis↗
PubMed1992

Surgical management of late right ventricular failure after Mustard or Senning repair.

BACKGROUND: Information on surgical management and outcome in patients who develop symptomatic right ventricular failure after prior Mustard or Senning operations is limited. METHODS AND RESULTS: From March 1987 to March 1991, 10 patients 3.6-23.5 years old (median, 7.0 years) with transposition of the great arteries and prior Mustard (six patients) or Senning (four patients) repairs (performed at ages 2 months to 5 years; median, 6 months) underwent surgical intervention for symptomatic right ventricular failure. In five of 10 patients, anatomic correction with either an arterial switch operation (three patients) or a pulmonary artery-to-aorta anastomosis and right ventricle-to-pulmonary artery conduit (two patients) was performed. Before anatomic correction in these five patients, four of five patients had a pulmonary artery band to prepare the left ventricle. The interval between preparation and correction ranged from 8 days to 12 months (median, 2 months). One patient died after an arterial switch operation. In the remaining five patients, coexisting left ventricular dysfunction precluded anatomic correction; all five patients survived cardiac transplantation. Survival for the entire group of 10 patients is 90%, and the median postoperative hospital stay was 17 days. During follow-up (12-62 months; median, 27 months), there were no deaths. Neoaortic insufficiency after anatomic correction was common (mild in one patient, moderate in two patients, and severe in one patient who required aortic valve replacement 4 months after surgery). In the transplantation group, one patient developed lymphoma 3 months after transplantation but is currently in remission after reduction of immunosuppression. CONCLUSIONS: In patients who develop late right ventricular failure after Mustard or Senning repair, surgical intervention with either anatomic correction or cardiac transplantation can be done with acceptable morbidity and low mortality. Neoaortic valve insufficiency demands close follow-up after anatomic correction.

Aorta, Thoracic↗
PubMed1992

Experimental comparison of albumin-sealed and gelatin-sealed knitted Dacron conduits. Porosity control, handling, sealant resorption, and healing.

Two high-porosity knitted Dacron vascular grafts sealed with aldehyde cross-linked gelatin or albumin were compared with respect to the following characteristics. Porosity control by the absorbable sealant was assessed with a water porosity meter at 120 mm Hg pressure. Ease of suturing was determined by an objective needle penetration test. Sealant resorption was assessed histologically in a subcutaneous immature rat model as well as in circulatory implants. Gross and microscopic healing characteristics were compared in circulatory implants in the thoracic aorta of sheep with use of a composite conduit in every animal, which allowed direct comparison of the two graft materials and minimized differences in healing between individual animals. Both grafts demonstrated excellent porosity control and better handling characteristics than woven Dacron. Sealant resorption was generally rapid, although residual albumin sealant was often seen adjacent to anastomoses. Residual sealant appeared to result in focally poor healing with focal loss of adhesion of surrounding tissue to graft. We conclude that details of sealant preparation and application can importantly influence the performance of presealed knitted Dacron grafts and should be carefully evaluated in the laboratory before clinical implantation is begun.

Albumins↗
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↗
PubMed1992

The dimensions of the right ventricular outflow tract and pulmonary arteries in tetralogy of Fallot and pulmonary stenosis.

Studies were undertaken of the cineangiograms in 196 consecutive patients entering two institutions with tetralogy of Fallot and pulmonary stenosis, none of whom had previously undergone a surgical procedure. The median age of the patients at the time of the study was 5.9 months. The diameters of the right ventricular infundibulum, pulmonary trunk, and the entirety of the right and left pulmonary arteries were measured (in millimeters), corrected for magnification, and expressed in standard deviation units (Z-values). The median values of the cineangiographically determined diameters of the right ventricular infundibulum and pulmonary trunk were smaller than those of 95% of normal individuals. The median values throughout the right and left pulmonary arteries were within the range of normal. Those of the distal branches of both the right and left pulmonary arteries were similar to the mean values in normal individuals. However, great variability of the dimensions between individuals, and along the pathway in individuals, characterized patients with tetralogy of Fallot. Diffuse narrowing of the pathways both proximally and distally was uncommon. The relation between the diameters of the pulmonary "anulus" and of the distal pulmonary trunk and origin of the left pulmonary artery explained the difficulty of extending an enlarging patch into a wide area distally in some patients.

Cineangiography↗
PubMed1992

Morphologic and surgical determinants of outcome events after repair of tetralogy of Fallot and pulmonary stenosis. A two-institution study.

Survival after entry and survival after repair (94%, 91%, and 91% at 1 month, 1 year, and 5 years, respectively) were similar in two institutions treating 196 consecutive patients, and there was no advantage (and a possible disadvantage) of a protocol of preliminary shunting and later repair in very young patients. Size and configuration of the right and left pulmonary arteries had no demonstrable effect on survival, prevalence of transannular patching, or postrepair right ventricular-left ventricular pressure ratio. Small size of the pulmonary "anulus" and trunk were risk factors for death, transannular patching, and high postrepair pressure ratio. High postrepair pressure ratio was a risk factor for death after repair. Very young age (less than about 3 months) was a risk factor for death after repair, particularly when other risk factors coexisted. The prevalence of transannular patching in patients with mild infundibular and pulmonary anulus and trunk hypoplasia decreased across the time of the study, without ill effect. The usefulness of measuring postrepair right ventricular-left ventricular pressure ratio is emphasized by the data.

Female↗
PubMed1992

Growth of composite conduits utilizing longitudinal arterial autograft in growing lambs.

We examined the growth potential of a longitudinal strip of autologous aortic wall incorporated in an autologous pericardial conduit in 10 lambs (mean age 26 days, mean weight 10.1 kg). A 15 mm length of descending thoracic aorta (diameter 11.5 +/- 7 mm) was excised and replaced with a composite autograft conduit of autologous pericardium with a longitudinally inserted aortic strip 5 mm in width taken from the excised aortic tissue. Radiopaque markers along all suture lines allowed determination of growth of the aortic strip relative to growth of the composite conduit and descending aorta, in addition to growth assessment by pathologic analysis. Plain x-ray films and aortograms were performed at 7 days (baseline) and at 3, 6, 9, and 12 months. No graft became stenotic or aneurysmal. The diameter of the descending aorta distal to the conduit increased from 11.7 +/- 1.3 mm to 18.7 +/- 2.1 mm. Appropriate growth of the autograft conduit was demonstrated by a minimal change in the diameter ratio of conduit to distal aorta from 1.00 to 1.02 during a period of 12 months. The aortic strip increased to 172% +/- 19%, 148% +/- 15%, and 256% +/- 31% of baseline width, length, and area, respectively (p less than 0.05). Histologic study confirmed the maintenance of normal architecture in the aortic strip and colonization of the pericardial tissue by aortic intimal and medial elements. A clinical implant with an autologous aortic strip in an aortic homograft in a 4-year-old child with tetralogy and pulmonary atresia has also grown, according to angiography, from 15 to 21 mm in diameter at 1 year's follow-up. This study confirms that the incorporation of a free autologous arterial patch graft as part of cardiovascular reconstructive procedures permits growth.

Animals↗
PubMed1991

Pulmonary valve-moderator band distance and association with development of double-chambered right ventricle.

Double-chambered right ventricle (DCRV), a form of right ventricular outflow obstruction that sometimes accompanies a ventricular septal defect (VSD), is associated with superior and rightward displacement of the septal insertion of the moderator band. It was hypothesized that this superior displacement is present and identifiable by echocardiography in patients with a VSD even before right ventricular outflow tract obstruction develops. Eight patients who had a previous echocardiographic study showing a VSD alone were echocardiographically diagnosed as having DCRV. Their initial echocardiographic studies were reviewed, and superior displacement of the moderator band was quantified by measuring the distance between the pulmonary valve and moderator band, normalized to tricuspid anulus diameter. These measurements were compared with those from the initial studies of the following 3 other groups: (1) an age-matched group of 10 patients with no structural heart disease; (2) an age-matched group of 10 patients with a VSD who did not develop DCRV; and (3) a group (not age-matched) of 10 patients with VSD and DCRV in whom subpulmonary obstruction was present on the initial study. The 8 patients who eventually developed subpulmonary obstruction had significant superior displacement of the moderator band at the time of their initial echocardiogram compared with that of the 2 age-matched control groups (p less than 0.01). In contrast, there was no significant difference in moderator band displacement between these patients and the 10 with DCRV who already had right ventricular outflow obstruction at their initial study (p = not significant).(ABSTRACT TRUNCATED AT 250 WORDS)

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↗
PubMed1991

Coarctation: do we need to resect ductal tissue?

A review of the literature as well as a retrospective review of 100 neonates undergoing operation for coarctation at Children's Hospital in Boston between 1972 and 1984 has not established clear superiority for either resection and end-to-end anastomosis or subclavian flap aortoplasty with respect to risk of recurrent coarctation. However, there is histological evidence that the juxtaductal coarctation shelf is composed of smooth muscle of ductal origin, which subsequently fibroses. This abnormal tissue may be at risk for late aneurysm development, particularly if balloon dilatation angioplasty is required. The fact that this abnormal tissue is not removed by the subclavian flap procedure is one of the inherent disadvantages of that procedure. Other disadvantages include the need to sacrifice the left subclavian artery and the fact that, unlike resection and end-to-end anastomosis, the subclavian flap procedure does not lend itself to augmentation of the hypoplastic distal aortic arch. Furthermore, occasionally a secondary coarctation membrane is present within the distal aortic arch, and though it is readily detected during the resection procedure, it can be missed with the subclavian flap procedure. Based on these considerations rather than on a demonstrated superiority of either procedure, my colleagues and I currently prefer resection and end-to-end anastomosis over subclavian flap aortoplasty.

Anastomosis, Surgical↗
PubMed1991

Intermediate procedures after first-stage Norwood operation facilitate subsequent repair.

Actuarial analysis of survival after first-stage palliative reconstructive operation for hypoplastic left heart syndrome has revealed a high out-of-hospital attrition rate over the first 18 months to 2 years postoperatively. Some of this mortality is related to development of anatomical problems such as restrictive atrial septal defect, neoaortic arch obstruction, and pulmonary artery distortion. The bidirectional Glenn shunt has proved to be an ideal adjunctive procedure for high-risk patients at the time of operation to correct such intermediate-term problems. The fenestrated Fontan procedure, which involves fenestration of the interatrial baffle placed as part of our current standard Fontan procedure, is applied for patients considered to be at moderate risk for a Fontan procedure. The decision regarding closure of the fenestration is made by hemodynamic study including temporary balloon occlusion of the fenestration. The fenestration is closed with the double-clamshell device, which is placed percutaneously in the catheterization laboratory and which is currently used for secundum atrial septal defect closure. Appropriate selection of patients for the bidirectional Glenn shunt or fenestrated Fontan procedure with or without fenestration closure has resulted in a dramatic decrease in mortality and morbidity for patients with all forms of single ventricle and for patients with hypoplastic left heart syndrome.

Actuarial Analysis↗
PubMed1991

Predictors of survival in neonates with critical aortic stenosis.

BACKGROUND: Failure of infants with critical aortic stenosis to survive after adequate valvotomy despite a left ventricular size that appears to be adequate indicates that additional preoperative anatomic features may contribute to mortality. METHODS AND RESULTS: Discriminant analysis was used to determine which of several echocardiographically measured left heart structures were independent predictors of survival after valvotomy for neonatal critical aortic stenosis. It was possible to predict outcome after classic valvotomy (two-ventricle-type repair) with 95% accuracy based on mitral valve area, long-axis dimension of the left ventricle relative to the long-axis dimension of the heart, diameter of the aortic root, and body surface area. Left ventricular volume was not a major determinant in this study, in part because patients who had initial valvotomy had been preselected in favor of an adequately sized left ventricle. Patients with multiple small left ventricular structures were found to have significantly improved survival after initial Norwood operation. In contrast, balloon valvotomy with subsequent Norwood procedure was usually unsuccessful. CONCLUSIONS: The adverse effects of small inflow, outflow, and/or cavity size of the left ventricle are cumulative. The accuracy of prediction of outcome based only on preoperative anatomy indicates that adequacy of valvotomy is not generally a limiting factor for survival in this group of patients. It is possible to identify subjects whose chance of survival is better after a Norwood procedure rather than valvotomy, even if left ventricular volume is not critically small.

Aortic Valve Stenosis↗
PubMed1991

Influence of time from donor death to graft harvest on conduit function of cryopreserved aortic allografts in lambs.

We examined the influence of time from donor death to graft harvest on conduit function of aortic allografts in the thoracic aortic position in 18 lambs (mean weight, 11.4 kg). Five grafts were harvested immediately after donor death (fresh), seven at 24 hours, and six at 48 hours following cadaver storage at 4 degrees C. All grafts were treated with antibiotics and were stored by cryopreservation. All animals were catheterized postoperatively and at 3, 6, 9, and 12 months. One animal in the 24-hour group developed an allograft aneurysm, and another one died from a ruptured allograft; one graft in the fresh group occluded by nine months. No animal, however, in the 48-hour group either developed an aneurysm or occluded. There was in fact minimal change in graft diameter over time (p greater than 0.05), while the native aorta grew appropriately (greater than 50%, p less than 0.01). Forty-eight hour delay from donor death to graft harvest did not have significant effect on conduit function. This information may expand the donor pool for allografts.

Animals↗
PubMed1991

Corrected transposition in situs inversus. Biventricular repair of associated cardiac anomalies.

Corrected transposition of the great arteries (C-TGA) in situs inversus [I,D,D] is a rare variant of C-TGA (5-8% of the cases). Few anatomic and surgical data on this anomaly have been published. Between 1974 and 1990, 13 such patients (mean age, 12.7 +/- 8.6 yr) underwent repair of associated cardiac anomalies, including ventricular septal defect (VSD) and pulmonary outflow tract obstruction (POTO) in all 13 patients and atrial septal defect (ASD) in 11. Systemic venous anomalies were present in four. Nine patients also had dextrocardia. Patches to close the VSD were placed on the right side of the ventricular septum (through a right [systemic] ventriculotomy) in two patients and on the left side of the ventricular septum in the other 11 via a left ventriculotomy in one or a morphological right (left-sided) atriotomy in 10. The POTO was relieved directly in five patients and bypassed by a left ventricle-pulmonary artery conduit in the other eight. There was one early death due to cerebral hemorrhage. Two patients required a pacemaker for permanent heart block. Other rhythm disturbances included transient heart block in three patients and late atrial fibrillation in one. All the survivors are asymptomatic as late as 15.5 years after the repair. One patient had conduit revision 10.5 years after the initial operation, two had residual POTO of greater than 40 mm Hg, and none had residual VSD. In conclusion, patients with [I,D,D] C-TGA present with a relatively uniform subset of anatomic lesions, including predominantly ASD, VSD, and POTO.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Vessel Prosthesis↗
PubMed1991

Neonatal repair of tetralogy of Fallot with and without pulmonary atresia.

Our experience with the arterial switch operation for transposition of the great arteries has confirmed the attainability of excellent results with elective neonatal surgery. Up to this time, we have repaired tetralogy of Fallot during the neonatal period only when symptoms, either severe persistent cyanosis or cyanotic spells, have been present. This review assesses the results of such nonelective neonatal correction of tetralogy between 1973 and 1988. Twenty-seven neonates with either symptomatic tetralogy of Fallot or symptomatic tetralogy of Fallot with valvar pulmonary atresia underwent repair. Mean age at repair was 8 +/- 8.4 days and mean weight was 3.0 +/- 0.7 kg. Unsatisfactory palliative shunts had previously been placed elsewhere in four patients. Twenty-five transannular patches and two conduits were used for reconstruction of the right ventricular outflow tract. There were five deaths in the hospital, three of which were due to avoidable technical problems. All deaths occurred in patients with pulmonary artery (Nakata) index less than 150 mm2/m2. One premature child weighing 2.3 kg displayed an absent pulmonary valve-like syndrome after repair and died late of respiratory complications caused by aneurysmal branch pulmonary arteries. Actuarial survival at 5 years was 74%. There was a single rapidly declining hazard phase for death, with the hazard approaching zero at 1 1/2 years after repair. Actuarial freedom from need for reoperation was 76% at 5 years. Postoperative catheterization of 15 long-term survivors showed right ventricular pressure less than 70% systemic in 13 cases. All patients are symptomatically well and functioning in sinus rhythm 1 to 15 years after repair (mean, 5 +/- 4 years). This experience with neonates with symptoms suggests that, if mortality is lower in the absence of symptoms, elective repair of tetralogy of Fallot could be reasonably undertaken during the first months of life.

Abnormalities, Multiple↗