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Biomedical subjects

P Burrows

Publications and source records attributed to P Burrows.

At least 37 records · Page 2Linked to original sources
PubMed1993

Nevus of Ota: treatment with high energy fluences of the Q-switched ruby laser.

BACKGROUND: The nevus of Ota is a benign dermal melanocytic lesion that has previously proved difficult to treat. Recently, the Q-switched ruby laser has been reported to be successful in treating benign pigmented lesions and tattoos. OBJECTIVE: Our study evaluates the treatment of 16 patients with nevus of Ota with the Q-switched ruby laser (694 nm). METHODS: Sixteen patients with nevus of Ota were treated with the Q-switched ruby laser with a pulse width of 28 nsec and energy fluences ranging from 7.5 to 10 J/cm2. Response to treatment was assessed by an independent investigator with photographs. RESULTS: The average number of treatments was 3.8 per patient. After two treatments, 44% of patients showed a 50% or greater improvement. After three treatments, 85% of patients showed a 50% or greater improvement; after four treatments, 100% of patients showed 50% or greater improvement. No patients had permanent textural changes or scarring. CONCLUSION: High-energy fluences of the Q-switched ruby laser lead to significant improvement without scarring of nevus of Ota after a few treatments.

Adolescent↗
PubMed1993

Hepatic kinetics and magnetic resonance imaging of gadolinium ethoxybenzyl diethylenetriaminepentacetic acid (Gd-EOB-DTPA) in dogs.

This complex study was designed to measure the transport and excretion characteristics of gadolinium ethoxybenzyl diethylenetriaminepentacetic acid (Gd-EOB-DTPA) in dog's livers following bolus and infusion. Simultaneous T1 magnetic resonance imaging was performed to measure maximum signal enhancement. Anaesthetized dogs had cannulation of the common bile duct and urinary bladder for collections and cannulation of the femoral artery and vein for monitoring, blood sampling and infusion. Gd-EOB-DTPA was administered by bolus (range 12.5-200 mumol/kg) and infusion (range 0.4-6.4 mumol/min per kg). An hepatic transport maximum 0.09-0.15 mumol/min/kg was achieved with a blood concentration of 0.03-0.06 mumol/mL. Marked hepatic affinity for Gd-EOB-DTPA was demonstrated with measurements of liver concentration. Maximum T1 signal enhancement was achieved with blood Gd-EOB-DTPA concentration of 0.02-0.03 mumol/mL and a liver concentration of 1-2 mumol/g. The transport maximum for Gd-EOB-DTPA in the dog was similar to that for ipodate and iodipamide and effective imaging was achieved with sub-maximal doses. The maximum signal enhancement at blood concentrations less than required for maximum transport suggest a wide latitude for effective clinical imaging.

Animals↗
PubMed1992

Multiple cerebral arteriovenous shunts in children: report of 13 cases.

The authors present a series of 13 multiple arteriovenous malformations (MAVMs) in the pediatric population (16.9% of their overall series of brain AVMs in this group). Two types of MAVMs can be distinguished: congenital and acquired. Congenital MAVMs may be of the nidus or fistula type. They may be uni- or bilateral, placed in one or several cerebral lobes, separated or close one to another, or even systematized (Wiburn-Mason syndrome). The symptoms created by these MAVMs are the same as those encountered in the presence of other AVMs, with hemorrhage as revealing symptom in 31% of patients. The responsibility of one particular nidus in the onset of clinical signs is often difficult to determine. From an angioarchitectural point of view, it seems that venous drainage changes are mainly responsible for the symptomatology. The natural history of these MAVMs is difficult to assess; spontaneous regression has been noted in 15% of cases. Acquired cerebral MAVMs can be due to angiogenesis ("sprouting" or "non-sprouting") around a true AVM because of previous hemorrhage or ischemia, or to pial shunts associated with dural arteriovenous malformations. The treatment of MAVMs is difficult. Embolization seems to the authors the best therapeutic modality available, as surgery or radiosurgery are often unable to treat these multifocal lesions. Anatomical cure is rarely obtained; the therapeutic strategy has to be targeted on the symptomatic lesions.

Adolescent↗
PubMed1991

Multifocal dural arteriovenous shunts in children.

The authors present four consecutive cases of multiple dural arteriovenous (AV) shunts in children. This entity represents a rare but severe clinical situation. The etiology of the shunts is not known. There is clinical and radiological evidence that they are evolutionary lesions. The clinical presentation in this series was usually by cardiac manifestations (one case), cerebrospinal fluid disorders (two cases), neurological symptoms (three cases), including intracranial hemorrhage (two cases), and cranial bruits (four cases). No radical treatment leading to anatomical cure of all dural AV shunts was thought to be possible using current methods, including modern endovascular and surgical techniques, in any of the four cases. Therefore, treatment was only symptomatic and directed at some of the AV shunts. Targeted arterial embolization with permanent embolic agents represents the most rational technique for symptomatic relief in these patients. However, clinical recurrence often happens without evidence of recanalization. Secondary multifocal pial AV shunts opening into the abnormal sinus occurred in two of the cases; they may have been induced by venous sump from the sinus draining the dural AV shunts. Mechanical occlusion (or excision) in multiple dural AV shunts in children does not represent a satisfactory goal, as the shunts can be the expression of a more complex and yet unknown disease.

Cerebral Angiography↗
PubMed1991

Thromboexclusion of the right ventricle in children with pulmonary atresia and intact ventricular septum.

Twelve children with pulmonary atresia and intact ventricular septum underwent closure of the tricuspid valve as a part of a new surgical procedure. In two cases a concomitant Fontan operation was performed. In each patient the right ventricle was very small and right ventricular pressure was higher than systemic pressure. Ventricle-coronary connections provided flow of desaturated blood from the right ventricle into the coronary arteries in 11 of 12 cases. Five of the 12 children did not survive operation and postmortem examination of each revealed severe acute and chronic myocardial ischemic damage and high-grade obstruction or interruption of the proximal left anterior descending coronary artery. Preoperative angiography demonstrated occlusive changes in the coronary arteries, resulting in right ventricular dependent circulation, in all five children who died and in one child who survived operation. Seven children who survived operation are well 4 months to 3.5 years later. Two have undergone subsequent successful Fontan operation and two others are considered suitable candidates for this operation. Tricuspid valve closure is recommended for a carefully selected group of infants with pulmonary atresia and intact ventricular septum provided a right ventricular-dependent coronary circulation can be excluded on the basis of preoperative coronary cineangiography.

Child↗
PubMed1990

Multiple cerebral arteriovenous malformations (AVMs). Review of our experience from 203 patients with cerebral vascular lesions.

From our series of 203 patients with cerebral vascular lesions, 18 (9%) could be included in the multiple arteriovenous malformation category. There were five patients with Rendu-Osler-Weber, one with Wyburn-Mason syndromes and two with concurrent arteriovenous malformations. The remaining ten patients (4%) had multiple brain arteriovenous malformations. Careful angiography with magnification is necessary to try to diagnose multiple brain AVMs, since these sometimes become apparent only after embolization of a larger dominant AVM. The incidence of multiple brain arteriovenous malformations is likely to have been underestimated due to the failure to recognize micro-arteriovenous malformations associated with larger arteriovenous malformations.

Adult↗
PubMed1990

An unusual case of craniofacial fibrous dysplasia presenting in early infancy.

Fibrous dysplasia (FD) of bone is one of the most frequently encountered anomalies of skeletal development. It may involve one or more bones and, particularly when polyostotic, is sometimes associated with abnormal skin pigmentation and endocrine abnormalities. FD occurs mainly in large limb bones, ribs, and craniofacial bones in older children and young adults. Usually craniofacial involvement is detected because of local swelling or asymmetry of the face or head. Neurological symptoms, primarily due to involvement of the foramina, have been reported but are not common. Infantile fibrous dysplasia of the craniofacial region has rarely been reported.

Angiography↗
PubMed1989

Balloon dilatation of congenital aortic valve stenosis in infants and children: short term and intermediate results.

Percutaneous balloon dilatation of the aortic valve was attempted in 25 consecutive patients with stenosis. The aortic valve diameters were normal for age. The balloon catheters were placed retrogradely, and their diameters were within 1-2 mm of the valve diameter and 3 (13 patients) or 6 cm (recent 12 patients) long. After dilatation the pressure gradients across the aortic valve were reduced significantly and the valve areas, measured in 10 patients, increased. Aortic regurgitation was detected in six patients before (grade I) the procedure and in 15 patients (6 grade I, 6 grade II, 3 grade III) after the procedure. In one patient the aortic valve could not be crossed and in three there was no reduction in the pressure drop. Nine patients have a sustained reduction in Doppler assessed gradients. There were vascular complications in 12 and these required surgical intervention in three patients. Balloon dilatation seems to be an effective short term palliative procedure in patients with congenital stenosis of the aortic valve.

Adolescent↗
PubMed1989

[True and false cerebral venous malformations. Venous pseudo-angiomas and cavernous hemangiomas].

The authors report their classification of venous anomalies and abnormalities within the central nervous system. The so-called venous angiomas are developmental venous anomalies (D.V.A.). The different forms encountered express the extreme variations in the transcerebral venous system. Their symptomatic character depends on the aging changes that the cerebral venous system undergoes or the frequent association of D.V.A. with cavernomas of the central nervous system. The cavernous hemangiomas are true tumors that present a proliferative character. They are localized in the dura or in the extradural space intracranially or at the spinal level. They must be considered as tumors and can be seen at angiography as they present a fine parenchymatous stain. The cavernomas of the central nervous system are true vascular malformations of the venous type; they are locally multiple, but can also be disseminated within the intracranial space. Some familial forms have been reported. They are often associated with D.V.A. They have a high bleeding potential, which does not carry a high morbidity or mortality incidence. However, the natural history of this lesion is poorly known at present. The spinal cord posterior fossa and paraventricular localizations present probably the least favorable localizations. Only the cavernomas deserve to belong to the vascular malformation group. The same comments and observations apply to spinal cord venous lesions.

Brain Neoplasms↗
PubMed1989

Perinatal nonimmune hydrops: diagnostic ultrasonography and related aspects of management.

Nonimmune hydrops fetalis may become the commonest form of hydrops seen in Western countries during the perinatal period, and it has at least a 50% mortality. This report describes five infants with nonimmune hydrops associated with maternal hydramnios and with congenital fetal lesions or disorders, ie, mediastinal teratoma, pulmonary leiomyosarcoma, Beckwith-Weidemann syndrome with omphalocele, fetal tachycardia, and Down's syndrome. Three of the infants survived the neonatal period and two of these underwent surgery for resection of their tumors early in the neonatal period. The third had an omphalocele repaired at 6 hours of age. The literature is reviewed with respect to the pathophysiology of nonimmune hydrops. Its diagnosis and treatment are discussed, with special emphasis on the role of ultrasound in its early diagnosis and optimal prenatal and postnatal management, and on the morbidity seen in survivors.

Female↗
PubMed1988

[Intracranial arteriovenous vascular lesions in children. Role of endovascular technics apropos of 44 cases].

The clinical and radiological files of 44 children with intracranial arteriovenous malformations (AVM (20 AVMs with ectasia of the vein of Galen, 21 parenchymatous or choroid AVMs without ectasia of the vein of Galen and 3 congenital dural AV fistulas) were reviewed. Clinical symptoms, architecture and the used therapy are analyzed. The only specific features of the pediatric population are the clinical systemic manifestations. In comparison to the adult population, a higher percentage of multiple lesions (20%), mostly direct AV fistulas were observed and conversely less associated arterial ectasias. Because of the high mortality associated to the natural history of these lesions in children, one must look for a complete and stable disappearance of the lesion. Among the therapeutic modalities available, embolization has proven a precise and efficient treatment. As the sole treatment, anatomic cure was obtained in 16.6% of patients; significant clinical improvement was obtained in an additional 50% of patients. The morbidity of the technique is low: 3.1% of neurologic complications (all being transitory). Embolizations associated to surgery achieved 3 more anatomic cure. The use of all these combinations allowed us to reach 79.2% of very good results (30.4% of anatomic cure). 3 cases of vein of Galen aneurysms died in our series (newborn during open surgery, one child 24 hours after thrombosis of the vein of Galen by endovascular means, a third one (newborn) one week after partial embolization as a defavorable outcome of major cardiac and hepatic insufficiency.

Adolescent↗
PubMed1987

The morphology of the right ventricular outflow tract after percutaneous pulmonary valvotomy: long term follow up.

Twenty nine patients (19 male, mean (SD) age 6.25 (0.5) years (range 0.16-15 years] with typical pulmonary valve stenosis were treated by balloon dilatation of the pulmonary valve. They were studied by echocardiography before the procedure, immediately after it, and at follow up (mean (SD) 10.2 (5.6) months, n = 18). The morphology of the pulmonary valve, the right ventricular-pulmonary artery gradient, and ratio of the systolic to diastolic endocardial dimensions (infundibular ratio) were examined. No patient had pulmonary regurgitation before the study. The valve gradient was significantly reduced (47%) from a mean (SD) of 72 (31) to 37 (23) mm Hg with no short term change in cardiac index after dilatation with a balloon with a mean (SD) diameter that was 118 (10.8)% of the valve annulus. The infundibular ratio was unchanged by the procedure (0.49 (0.11) (n = 21) before dilatation and 0.47 (0.14) (n = 16) after dilatation). In twenty seven patients the commissure of the pulmonary valve was seen to be torn after dilatation. Two patients with bicuspid valves had flail leaflets. Doppler examination at follow up showed mild pulmonary insufficiency in all 29 patients; the mean (SD) valve gradient (31 (+/- 21) mm Hg) at follow up was no different from the gradient found immediately after the procedure and infundibular ratio (0.58 (0.15) was not abnormal. These data indicate that commissural tears are the primary mechanism of valve disruption and demonstrate that the dynamic right ventricular outflow tract obstruction relaxes and gradient reduction persists at follow up.

Adolescent↗
PubMed1987

Two-dimensional and pulsed Doppler echocardiography in the postoperative evaluation of total anomalous pulmonary venous connection.

The role of combined two-dimensional and pulsed Doppler echocardiography in the postoperative assessment of patients with total anomalous pulmonary venous connection was evaluated. Twenty-two cases with a median age of 9.5 weeks at the initial examination were evaluated. Serial ultrasound examinations were performed throughout the study period. The ultrasound results were compared with chest radiographs obtained during the same period. Of the 22 patients, 16 had normal pulmonary venous flow profiles characterized by low-velocity laminar flow. Of this group 12 had persistent radiographic postoperative pulmonary edema that cleared in all by 4 months. Six patients with pulmonary venous obstruction were identified, the diagnosis being confirmed at catheterization or autopsy. The venous flow pattern in this group was uniformly high velocity and turbulent. It was possible to localize the site of obstruction in each case. Although pulmonary edema was present in each patient, the chest radiograph did not provide reliable information as to the exact site of obstruction. Combined two-dimensional and Doppler echocardiography is a useful adjunct in the postoperative evaluation of patients with total anomalous pulmonary venous connection.

Child, Preschool↗
PubMed1986

Developmental venous anomalies (DVA): the so-called venous angioma.

Following a review of the literature it is possible to demonstrate the "normality" of the so called venous angiomas. They should be named Developmental Venous Anomaly (DVA). They illustrate in their two extreme types (superficial and deep) the hemodynamic equilibrium of the transcortical venous drainage in the periependymal zones. Venous ectasias and varices which can be encountered, associated with DVA constitute an acquired feature in relation to a venous outlet obstacle. The sinus pericranii represents an extracerebral DVA, but also corresponds to a normal variation. As any extreme anatomical variant, each DVA corresponds to a weak situation which may express itself clinically; only rare situations justify a radical treatment.

Cerebral Veins↗
PubMed1986

Cross-sectional echocardiography in the evaluation of aortic valve prolapse associated with ventricular septal defect.

Twenty consecutive patients with ventricular septal defect and aortic valve prolapse were evaluated by cross-sectional echocardiography. Angiographic confirmation was available in all and surgical confirmation was found in 17. In 19, the right coronary cusp was involved and appeared to plug the defect in the precordial long- and short-axis cut. The cusp was deformed and appeared to pivot from the crest of the interventricular septum. In all 19 angiography demonstrated prolapse of the right cusp. Noncoronary cusp prolapse was observed in two by cross-sectional echocardiography and in six by angiocardiography. The ventricular septal defect was perimembranous in 14 and doubly committed subarterial in six by echocardiography. Angiographically, the ventricular septal defect was felt to be perimembranous in 15 and doubly committed in five. Aortic regurgitation was detected by Doppler interrogation in seven, all of whom underwent plication of the right coronary cusp. Angiographic evidence of regurgitation was noted in 11, but four were mild and possibly related to catheter position. Five patients had associated muscular right ventricular outflow tract obstruction and three had a subaortic ridge. Combined cross-sectional and pulsed Doppler echocardiography provide a reliable assessment of right coronary cusp prolapse associated with a ventricular septal defect. Noncoronary cusp prolapse appears more difficult to detect. This technique should help optimize the management of patients by providing a means of early detection prior to the development of aortic regurgitation.

Adolescent↗
PubMed1986

Lumbo-peritoneal shunt malfunction. A new, simple and reliable CT sign.

Sixty CT scans in 31 patients who underwent lumboperitoneal shunting for communicating hydrocephalus showed that the size of the ventricles did not represent a good indicator of shunt malfunction. Instead, we discovered that the size of the basal cisterns around the brain stem enabled us to predict blockage earlier and more reliably. In a well functioning shunt, the basal cisterns are usually not visualized. In children with clinical shunt malfunction the cisterns dilate and become visible again. This occurs earlier and more frequently than ventricular enlargement. We therefore conclude that visible cisterns in association with persistent symptoms of malfunction are more reliable predictors of a true blockage that requires shunt revision than serial studies of ventricular size.

Brain↗