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Biomedical subjects

J Stark

Publications and source records attributed to J Stark.

At least 91 records · Page 5Linked to original sources

The use of polyglyconate in surgery of congenital heart defects: comparison with polypropylene.

Absorbable suture material has several theoretical advantages in operations for congenital heart defects performed in infancy. This study compares handling characteristics of absorbable polyglyconate (Maxon) and non-absorbable polypropylene used in a variety of operations for congenital heart defects. There was no difference in mortality and morbidity between the two groups (50 patients each). Satisfactory tensile strength was noted in both groups. Maxon had more suppleness and first throw holding but more tissue drag when compared with polypropylene. Maxon was considered to be a suitable suture material in operations for congenital heart defects when the use of absorbable material is indicated.

Adolescent↗

Surgical treatment of aortic coarctation in infants younger than three months: 1985 to 1990. Success of extended end-to-end arch aortoplasty.

There remains controversy regarding the appropriate surgical treatment of coarctation of the aorta in infants. In 1985 we introduced the extended end-to-end repair into our practice and now wish to present a review of our recent experience. One hundred fifty-one infants younger than 3 months of age underwent repair of coarctation between 1985 and 1990. In 25% and 33% of the patients, there was hypoplasia of the isthmus and of the transverse arch, respectively. Surgical procedures were as follows: subclavian flap angioplasty in 15 patients, resection with a traditional end-to-end anastomosis in 43, and resection with an extended end-to-end anastomosis into the arch in 77. In 30 patients, the extension was proximal to the origin of the left carotid artery (radically extended end-to-end anastomosis). Other procedures were used in 16 patients. Mortality (13 early and 12 late deaths) was related on multivariate analysis to the presence of an associated major heart defect, preoperative resuscitation, and direct postoperative gradient over the arch. This immediate postoperative gradient was significantly lower after both extended and radically extended end-to-end anastomosis if there was a hypoplastic isthmus, and after radically extended end-to-end anastomosis if the transverse arch was hypoplastic. Actuarial freedom from recoarctation at 4 years was 57% (confidence limits 28% to 78%) after subclavian flap angioplasty, 77% (confidence limits 60% to 87%) after end-to-end anastomosis, 83% (confidence limits 66% to 92%) after extended end-to-end anastomosis and 96% (confidence limits 77% to 100%) after radically extended end-to-end anastomosis. We conclude that the extended end-to-end anastomosis and radical end-to-end anastomosis appear to offer the best prognosis for all infants with coarctation. The technique can be applied successfully to almost all types of arch anomalies.

Age Factors↗

Pulmonary artery sling.

Eighteen patients who underwent surgical treatment of pulmonary artery sling at this institution since 1969 were reviewed. Four of them had associated tracheal stenoses produced by complete cartilaginous rings (stovepipe trachea). All patients underwent operation. The median age at operation was 180 days (range, 27 days to 54 months). In the 14 patients with isolated pulmonary sling, the operation consisted of division of left pulmonary artery and reimplantation into the main pulmonary artery anterior to the trachea. In the 4 patients with stovepipe trachea, the stenotic tracheal segment was resected on cardiopulmonary bypass and the left pulmonary artery was brought anterior to the trachea before the latter was reanastomosed to the main pulmonary artery. There were no early deaths. One patient died late. The pulmonary artery anastomosis was patent in all 14 patients investigated postoperatively. Three patients have residual tracheobronchial problems. One patient is mentally retarded and is institutionalized. All other patients are symptom-free and growing normally and have normal chest radiographs.

Child, Preschool↗

Surgical treatment of persistent ductus arteriosus complicated by bacterial endocarditis.

A seven-year-old girl with persistent ductus arteriosus developed acute bacterial endocarditis with large vegetations in the ductus and the left pulmonary artery. Conservative management was not successful: repeated embolisation to the lungs necessitated operation during the acute endocarditis. Details of the operative technique are presented and discussed.

Child↗

Minimisation of priming volume and blood saving in paediatric cardiac surgery.

We started a programme of donor blood reduction for open heart surgery in children in 1983. At first, only meticulous surgical and perfusion techniques were used. Later, increased haemodilution was added. Miniaturisation of the perfusion circuit and introduction of blood taken prior from the patient further decreased donor blood requirements. In 1989, we used 0.89 l per patient compared to 3.2 l per patient in 1983. Miniaturisation of the circuit was tested in a pilot study on 30 children undergoing the Senning operation in 1988. Priming volume was reduced from 661 +/- 72 ml to 421 +/- 62 ml. In 1989, 167 out of 194 children (86%) received a clear prime. Ninety-seven of 100 children whose weight was over 15 kg received a clear prime: 55 did not require subsequent transfusion. Prime miniaturisation and autotransfusion can considerably reduce blood requirements for open heart surgery.

Blood Donors↗

The impact of respiratory infections on asthma.

It is apparent that the effects of viral respiratory infections on the development of airway hyperresponsiveness are multiple and interrelated and involved the production of viral specific IgE, upregulation of leukocyte inflammatory activity, enhancement of the factors involved in the generation of late phase allergic responses, altered beta-adrenergic and cholinergic nervous system activity, and damage to the airway epithelium. The summation of these effects is the development of airway inflammation rather than a direct effect on bronchial smooth muscle, per se. An understanding of this pathogenesis underscores the relative importance of anti-inflammatory rather than antimicrobial therapy in viral-induced exacerbations in asthma symptoms.

Adolescent↗

Radiosensitivity and responsiveness to recombinant interleukin-2 of effector cells of graft vs. host disease and mixed lymphocyte reaction in mice.

Synergistic effects of recombinant interleukin-2 (IL-2) or irradiated spleen cells were investigated in vivo and in vitro. Irradiated (750 cGy) C57BL/6 spleen cells infused to sublethally irradiated (500 cGy) BALB/c mice treated with IL-2 (1,000 U 3 times/day) caused graft vs. host-like disease (GVHD) in 3 of 11 mice. Similarly irradiated allogenic spleen cells caused no GVHD in irradiated recipients not administered IL-2. No sign of autologous GVHD was found in mice that received irradiated syngeneic spleen cells with IL-2. Addition of recombinant IL-2 in vitro to mixed lymphocyte reactions (MLR) using irradiated (500 cGy) allogeneic responder spleen cells augmented the 3H-TdR uptake fourfold compared to cultures without IL-2, but was 44-fold below the allogeneic response of nonirradiated C57BL/6 spleen cells. Il-2-induced cell proliferation was also noted in syngeneic MLR, but did not lead to GVHD in in vivo experiments. The data suggest that IL-2 may potentiate GVHD and alloreactivity induced by an adequate number of irradiated, nondividing but viable allogeneic spleen cells and/or that secretion of IL-2 by alloactivated T lymphocytes, supplied exogenously in the present study, may play a role in the GVHD syndrome. Since neither viable but nonreplicating T cells nor IL-2 alone caused GVHD, it is suggested that endogenously produced IL-2 by alloactivated T lymphocytes may be important in the development of the GVHD syndrome, independent of its main function of enhancing T lymphocyte proliferation. On the other hand, the lack of GVHD following administration of high numbers of irradiated or nonirradiated syngeneic spleen cells with IL-2 implies that allogeneic T lymphocytes and not IL-2 activated MHC-nonrestricted cytotoxic cells play a role in inducing the GVHD syndrome in vivo.

Animals↗

Current surgical technique to repair Fallot's tetralogy with absent pulmonary valve syndrome.

The experience with surgical repair of Fallot's tetralogy and absent pulmonary valve syndrome is reviewed. Twenty-two patients aged 1 day to 8 years were treated between 1982 and 1989 using one surgical technique. This consisted of resection of the main pulmonary artery and large parts of the anterior wall of the right and left pulmonary artery. The ventricular septal defect was closed with a patch, and an aortic or pulmonary homograft (size, 8 to 24 mm) was interposed between the right ventricle and the pulmonary artery. Two of the 8 infants operated on died; there was one late death. All 14 older children survived the operation. All survivors are well up to 7 years follow-up (mean follow-up, 3.6 years). We recommend early treatment of infants; older children can be treated electively. The technique used in our series gives excellent results.

Child↗

Pulmonary hypertensive crises following surgery for congenital heart defects in young children.

In this clinical study, 20 high risk infants and neonates were monitored to identify and characterize pulmonary hypertensive crises following surgery for congenital cardiac defects. Monitoring included right ventricular or pulmonary artery pressure catheters and transcutaneous oximetry. Eleven patients also had continuous analog recording of hemodynamic data so that antecedents of crises and the sequence of events following treatment could be reconstructed. Eleven of the 20 patients had one or more crises. Six of these ultimately died whereas 5 patients survived with aggressive vasodilator therapy. Four patients without crises but with episodic pulmonary hypertension benefitted from pulmonary vasodilator therapy to ease weaning from ventilatory support. Typically, each crisis was associated with a stress event. Crises were difficult to ablate if not rapidly treated and multiple crises would often cluster following an initial event. High dose narcotic (fentanyl) analgesia was found to be important in the postoperative management. Tolazoline and oxygen were the most consistently useful vasodilators, but isoproterenol and nitrates also played a role. Five of the children who died were examined post mortem: histologically, there was increased pulmonary arterial muscularization in 2, in none were there changes of fixed pulmonary vascular disease. The postoperative management must be individualized on the basis of monitored responses of pulmonary circulation.

Biopsy↗

Surgical treatment of aortico-left ventricular tunnel.

Thirteen children (age range 6 h-11 years, median 4 months) operated upon for aortico-left ventricular tunnel since 1971 are reported. All patients had systolic and diastolic murmurs, 4 of 5 neonates were in severe congestive heart failure. Twelve children had left ventricular hypertrophy on ECG with an ischaemic pattern in the neonates. Chest X-ray revealed cardiomegaly with a broad upper mediastinal shadow from the enlarged aorta. Echocardiography (2DE) revealed a tubular communication between the aorta and the left ventricle bypassing the aortic valve and massive regurgitation through this tunnel demonstrated by Doppler sonography. In 8 patients, the diagnosis was confirmed by angiography. The tunnel arose from the right coronary sinus in 12 and from the left coronary sinus in 1 patient. The tunnel was closed at both ends in 8, at the aortic end only in 3 and at the ventricular end in the remaining 2 cases. One 6-day-old infant, operated upon in 1971 died postoperatively. There was 1 non-cardiac related late death due to a brain tumour. Echocardiographic analysis of left ventricular size and function was carried out in 9 children up to 39 months after surgery. Mild to moderate aortic incompetence was detected during the follow-up period in 2 of 12 patients. All surviving children are leading normal lives.

Aorta↗

The use of the right atrial flap in total cavopulmonary connection.

A technical modification of total cavopulmonary anastomosis (TCPC) is described. Inferior vena cava (IVC) channel is constructed from the right atrial wall in a fashion similar to Senning's operation. The use of Gore-TexR (W.L. Gore & Associates, Inc.) patch or tube is avoided. We have used the technique in 11 patients between 1988 and 1991 (six complex transpositions or double outlets with one hypoplastic ventricular chamber and/or straddling of the atrioventricular (AV) valve, four double inlet ventricles with pulmonary stenosis, and one tricuspid atresia). Superior vena cava (SVC)/IVC to pulmonary artery gradient was less than 2 mmHg in all patients. SVC/IVC pressure was 10-15 mmHg (mean 12.3 mmHg), transpulmonary gradient 5-8 mmHg (mean 6.4 mmHg). We have not observed any adverse effects such as arrhythmias or increased pleural drainage when we compared those patients with 85 children in whom the TCPC was performed with Gore-TexR patch/tube. The presented technique is simple, avoids the use of anticoagulants, and may have a possible long-term advantage in allowing growth of the IVC channel.

Anastomosis, Surgical↗

Continuous infusion of interleukin-2 and cyclophosphamide as treatment of advanced cancers: a National Biotherapy Study Group Trial.

We have evaluated the effect of Interleukin-2 [IL-2] after Cyclophosphamide (C) chemotherapy in 41 patients with metastatic cancer. IL-2 was given as a continuous infusion priming cycle 36 hours after C at 1 gm/m2 intravenously. In 39 evaluable patients, there were no complete remissions [CR], 2 partial remissions [PR], and 1 had a minor response [MR]. Stable disease for 30 days was seen in 16 patients whereas 20 progressed. The durations of partial and minor responses were brief, ranging from 1-6 months. Grade 3-4 neutropenia was seen in 41%. This was more severe than seen with IL-2 alone or IL-2 combined with lower doses of C. The marrow suppression was due to the chemotherapy. This combination of IL-2 and C appears to be reasonably well tolerated by patients, but toxicity is greater and the response rate is no better than results achieved by IL-2 alone. Responses of 26 patients with renal cancer appear to be inferior to our historical data using IL-2/LAK cells without C. Immune monitoring demonstrated changes expected with C chemotherapy (i.e., a non-selective decline in immune function). C induced no further differences in IL-2 induced changes in immune function.

Adult↗

Management of major tracheal hemorrhage after repair of complex congenital heart defects.

Two patients with complex congenital heart defects (a 4-year-old with transposition of the great arteries, ventricular septal defect, and left ventricular outflow tract obstruction and a 3 1/2-year-old with double-outlet right ventricle, subpulmonary stenosis, and complete atrio-ventricular septal defect) suffered multiple major hemorrhages from the tracheobronchial tree (28 and 7 bleeding events, respectively). Successful management included tracheostomy, sedation and paralysis, systemic hypotension, and systemic hypothermia for a period of seven days. Both patients survived.

Anesthesia↗

Successful surgical treatment of tracheal compression following right pneumonectomy in infancy. Long-term follow-up.

Two patients (aged 10 and 16 months) underwent right pneumonectomy: one for an oesophageal bronchus, the other for a hypoplastic right lung with sequestration. Both patients subsequently developed severe stridor. The heart rotated to the right and the aortic arch compressed the trachea. This unusual vascular compression was treated by a bypass graft between the ascending and descending aorta and division of the aortic arch between the left carotid and left subclavian artery at the age of 5 years and 4 months, and 20 months respectively. The postoperative recovery was uneventful in the first patient. The second patient required 7 weeks of ventilatory support. Both patients are well (14 and 7 years after surgery). Cardiac catheterisation and angiography in the first patient and Doppler echocardiography in the second demonstrated unrestricted flow through the graft into the descending aorta. Pulmonary function studies showed a restrictive defect with some obstruction in both children. Despite this finding, both patients enjoy a normal life with some sporting activities. The long-term results suggest the effectiveness of this procedure in the treatment of this rare but severe complication of pneumonectomy in infancy.

Aorta↗