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Biomedical subjects

R G Williams

Publications and source records attributed to R G Williams.

At least 19 recordsLinked to original sources
PubMed1992

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.

Abnormalities, Multiple↗
PubMed1992

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)

Adolescent↗
PubMed1992

The effect of adenoid and tonsil surgery on nasalance.

The change in nasalance following adenoidectomy, tonsillectomy and adenotonsillectomy was studied in 44 children. A subjective assessment of each child's naso-pharyngeal airway was made preoperatively based on a questionnaire completed by the parents. There was no significant change in the nasalance of children following adenoidectomy, but there was a significant increase in the nasalance following tonsillectomy (P = 0.02) and after adenotonsillectomy (P = 0.001). There was no relationship between the change in nasalance and the adenoid volume removed at operation. There was good agreement between the parental subjective assessment of the naso-pharyngeal airway and the preoperative nasalance score, with the best correlation in the adenoidectomy group (r = -0.8) and the adenotonsillectomy group (r = -0.7). Nasalance is more closely related to the size of the naso-pharyngeal airway than to the actual adenoid volume, and measurements of nasalance are of no benefit in predicting adenoid volume. Tonsillectomy had a significantly greater effect on nasalance than adenoidectomy, and adenotonsillectomy had the greatest effect. Further studies are needed to relate nasalance to the size of the naso-pharyngeal airway, but it appears to relate well to the subjective assessment of the airway and may be of use in patient selection for surgery.

Adenoidectomy↗
PubMed1992

Value of acute-phase angiography in the detection of vascular injuries caused by gunshot wounds to the head: analysis of 12 cases.

A study of the angiographic findings in consecutive civilian patients with cranial gunshot wounds examined in the acute stage has not been done. Most prior clinical studies have evaluated the findings in survivors in the subacute or chronic stages and have often been of war-time casualties. We determined the clinicoradiologic features of six cases of posttraumatic intracranial aneurysm, vascular occlusion, or arteriovenous fistula caused by penetrating missiles among 12 civilian patients who were examined in the acute posttraumatic stage (within 48 hr of injury) during a 1-year period. Three internal carotid/vertebral artery aneurysms, one external carotid artery aneurysm, one combined aneurysm/arteriovenous fistula of the vertebrobasilar circulation, and one cerebral venous occlusion were identified. The 50% overall prevalence of major vascular lesions in this series of civilian patients with penetrating missile injuries examined in the acute stage suggests these injuries are more common than previously suspected. It may indicate that selective cerebral angiography should be considered in the evaluation of the cranial vascular system of such persons.

Cerebral Angiography↗
PubMed1992

Nasal airflow asymmetry and the effects of a topical nasal decongestant.

Nasal airway resistance (NAR) is normally asymmetrical due to the nasal cycle. The aims of this study were to determine the degree of this asymmetry in healthy subjects and those with acute rhinitis associated with common cold, and to investigate how the administration of a topical nasal decongestant (xylometazoline) influenced the asymmetry in NAR. Unilateral NAR was measured by active anterior rhinomanometry, and was shown to be asymmetrical in both healthy subjects and those suffering with acute rhinitis. The asymmetry in NAR was greater in those with acute rhinitis than in the healthy group, with a ratio between "high" and "low" sides of 2.3:1 in the rhinitis group compared to a ratio of 1.7:1 in the healthy subjects. Administration of a topical nasal decongestant caused a significant decrease in total NAR in both groups and abolished the asymmetry in NAR in the healthy subjects (ratio is 1:1 after decongestion). However, significant asymmetry of NAR was still present in the group with acute rhinitis following the administration of decongestant (ratio is 1.5:1 after decongestion). These findings show that the normal asymmetry in NAR was increased during acute rhinitis associated with common cold, and that in healthy subjects (but not in those with rhinitis) the asymmetry was abolished by administration of a topical decongestant. The results are discussed in relation to nasal sympathetic tone and nasal blood flow.

Acute Disease↗
PubMed1992

Immunocytochemical and electrophysiological investigations of central neurones in the parasitic nematode Ascaris suum.

Here we report on preliminary investigations into the morphological, neurochemical and electrophysiological characteristics of central neurones in the parasitic nematode Ascaris suum. The neurones do not display all or none action potentials and apparently have low resting membrane potentials. Neurones have been shown to respond to acetylcholine. Immunoreactivity to a diverse range of neuropeptides has been demonstrated.

Acetylcholine↗
PubMed1992

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.

Anastomosis, Surgical↗
PubMed1992

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.

Aortic Valve↗
PubMed1991

Natural history of the eosinophilia-myalgia syndrome.

OBJECTIVE: To describe the natural history and disease progression of the eosinophilia-myalgia syndrome and to assess the therapeutic effects of orally administered steroids on the disorder as of October 1990. DESIGN: Case-series analysis. A cohort of 45 patients with the eosinophilia-myalgia syndrome was followed prospectively by periodic telephone interviews and medical examinations for an average of 14 months after onset of illness. SETTING: Washington state. PATIENTS: The cases of 47 patients were reported to the Washington State Department of Health from 1 July to 12 December 1989. Two patients were unavailable for follow-up, and the remaining 45 completed the study. MAIN RESULTS: Patients were predominantly non-Hispanic white women (87%) with an average age of 49 years. Symptoms typically progressed from early onset of myalgia and fatigue to later development of neurologic and scleroderma-like skin changes. Six (13%) patients recovered completely within 2 to 5 months of symptom onset. After 14 months of illness, over half of the patients who initially presented with myalgia, fatigue, or scleroderma-like skin changes remained symptomatic. The average severity of each major symptom was measured using interviews and patient self-reports and has improved subjectively by at least 40%. Statistical analyses showed no significant difference in long-term symptom duration or severity between patients treated and those not treated with prednisone. CONCLUSIONS: The eosinophilia-myalgia syndrome is a long-term illness characterized by progressive improvement during the first 25 weeks after symptom onset, followed by a protracted phase of symptom resolution. We could not show a clear-cut benefit of prednisone in reducing the long-term severity or duration of the disease.

Adolescent↗
PubMed1991

Impact of intraoperative echocardiography on surgical management of congenital heart disease.

Intraoperative echocardiography was performed by epicardial, 2-dimensional, low- and high-pulsed repetition frequency, continuous-wave Doppler and color flow mapping in 50 patients. Forty studies were performed before and 44 studies after cardiopulmonary bypass. Studies before cardiopulmonary bypass agreed with preoperative evaluation. After cardiopulmonary bypass, studies revealed that 11 of 25 patients who underwent repair of ventricular septal defects had residual ventricular septal defects, and 1 of 25 patients who underwent atrial septal repair had 1 residual atrial communication. One patient with a "Swiss cheese" ventricular septum underwent repeat cardiopulmonary bypass to close residual ventricular septal defects. The patient with a residual atrial communication required immediate reoperation because of a right to left shunt after a modified Fontan procedure. Eight of 10 remaining residual ventricular septal defects spontaneously closed 1 to 41 days after operation. Assessment of postcardiopulmonary bypass and postoperative valvular regurgitation in 21 valves revealed good correlation (p less than 0.01). However, 1 patient required reoperation for mitral valve replacement on the sixth postoperative day. The correlation was fair between postcardiopulmonary bypass and postoperative residual stenotic pressure gradients in 12 surgically repaired stenotic lesions. This study shows that little additional information is added to a comprehensive preoperative evaluation by precardiopulmonary bypass intraoperative echocardiography. Postcardiopulmonary bypass intraoperative echocardiography is useful in identifying residual shunts. Assessment of stenotic gradients and valvular regurgitation must be interpreted in light of a changing hemodynamic state.

Cardiopulmonary Bypass↗
PubMed1991

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.

Animals↗
PubMed1991

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.

Adolescent↗
PubMed1991

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.

Adolescent↗