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Biomedical subjects

R B Towbin

Publications and source records attributed to R B Towbin.

At least 37 records · Page 2Linked to original sources
PubMed1996

Left pulmonary artery sling: diagnosis and delineation of associated tracheobronchial anomalies with MR.

BACKGROUND: The left pulmonary artery sling anomaly (SLPA) has generated controversy about its diagnosis, imaging and management particularly with regard to associated tracheobronchial anomalies. Objective. To evaluate the role of MR imaging in defining airway and vascular relationships in SLPA. MATERIALS AND METHODS: Retrospective review of the imaging and clinical records of three children with SLPA who underwent MRI including three dimensional image reconstruction. MR was compared and correlated with other imaging methods: plain chest radiographs (3); bronchoscopy (3); barium esophagram (1); echocardiography (2); cineangiography (2). RESULTS: MRI was vastly superior to other methods for clearly depicting airway and vascular anatomy and interrelationships. Good quality imaging and safe sedation was easily achieved in young infants. MR also provided accurate noninvasive evaluation of the reconstructed pulmonary artery and airway postoperatively. CONCLUSION: MR is capable of differentiating the two subtypes of SLPA. Specific delineation of vascular and airway anatomy and spatial relationships is essential for surgical management: reimplantation of LPA in type I and both LPA reimplantation and airway reconstruction in type II because of associated long segment airway stenosis.

Airway Obstruction↗
PubMed1996

Long-term outcome after sagittal synostosis operations.

We evaluated 27 children who had been operated on 5-10 years previously for sagittal synostosis. The mean age at operation was 0.55 years. Twenty-two children were treated by the senior author's technique, 4 by the Pi craniectomy technique and 1 by parasagittal sagittal strip craniectomies. The mean age at follow-up was 9.6 years. The cosmetic appearance of the head was graded independently by 3 examiners. Skull radiographs were graded by 2 examiners according to the appearance and presence of beaten copper markings. The cephalic index was measured. Frequent headaches were reported in 7 of 27 children and were migrainous in 3 of the 7. No child had papilledema. The children's appearance was considered to be normal or mildly abnormally by the parents in every case and by the medical observers in 25 of 27 (93%). The only 2 children with an unacceptable appearance were either operated late (3.3 years) or had a craniofacial syndrome. Skull radiographs revealed a normal or mildly abnormal appearance in 18-19 children, depending on the observer. Beaten copper markings were observed to some extent in 14 of 27 cases and did not correlate with the presence of headaches. The cranial index ranged from 62 to 78 with a mean of 70 (normal 81). Sagittal reconstructions resulted in an acceptable appearance 5-10 years postoperatively in all cases operated on at less than 1 year of age who had no syndrome. The need for long-term follow-up of children after sagittal synostosis operations cannot be determined from this sample size.

Cephalometry↗
PubMed1996

Imaging in liver transplantation.

Thoughtfully planned and skillfully executed diagnostic and interventional imaging is indispensible in preoperative assessment of the pediatric liver transplant candidate and for the detection and management of the myriad postoperative complications that may affect the liver recipient.

Child↗
PubMed1996

Interventional procedures in the gastrointestinal tract in children.

Significant growth and innovation in interventional procedures involving the gastrointestinal tract has occurred over the last 15 years. The authors discuss historical background, procedural planning, sedation, and monitoring during the procedure, technique, postprocedural care, and potential procedural complications in the pediatric population.

Child↗
PubMed1994

Intervention in the critically ill patient.

In summary, interventional techniques are well-established and offer safe and effective alternatives for management of patients in the intensive care unit or other setting. It is likely that the radiologist will become more involved in the management of ill children and adults. It is hoped that this will reduce the need for opened surgical procedures, reduce the complexity of surgery, and provide treatment options for complications.

Adult↗
PubMed1993

Preradiation chemotherapy in advanced medulloblastoma. A Pediatric Oncology Group pilot study.

BACKGROUND: Children diagnosed with medulloblastoma whose tumor involves the brain stem or has spread through the cerebrospinal fluid pathways to other areas of the brain or spinal cord have a poor prognosis despite therapy with surgery, craniospinal irradiation (CSI), and chemotherapy. Preradiation chemotherapy may improve the outlook for these patients. METHODS: To further study the role and feasibility of preradiation chemotherapy, children between the ages of 4 and 21 years diagnosed with advanced medulloblastoma and measurable disease were enrolled in the Pediatric Oncology Group 8695 study. Patients were treated with a 9-week course of vincristine, cisplatin, and cyclophosphamide followed by CSI. Imaging films were reviewed centrally for eligibility and response to chemotherapy. Toxicity to chemotherapy and radiation as well as delays and modifications in subsequent CSI were recorded. RESULTS: Thirteen of 30 fully evaluable patients achieved complete or partial response (43%) to chemotherapy. Toxicity was mostly fever and neutropenia after cyclophosphamide, which is predictable and tolerable. Radiation therapy was delivered in full doses and volumes in most patients but was delayed in its start in most patients. Central review of films revealed frequent use of different imaging modalities at baseline and after therapy, making accurate assessment of tumor response difficult. CONCLUSION: Preradiation chemotherapy with vincristine, cisplatin, and cyclophosphamide is active in patients with advanced medulloblastoma but should be modified to minimize the risk of progressive disease while on therapy and to avoid delays in starting radiation therapy. Consistent use of the same neuroimaging modality is essential in documenting response.

Adolescent↗
PubMed1993

Pediatric sedation: short-term effects.

A prospective investigation on the short-term effects of various sedation regimens on 549 nonhospitalized magnetic resonance (MR) patients was performed. The drugs evaluated were chloral hydrate, pentobarbital, midazolam, and diazepam (fentanyl was used for enhancement after any of these drugs). The overall safety and efficacy were quite good with all the regimens. Overall, 84% of children slept less than 8 h after the examination, 90% were drowsy and/or unsteady for less than 8 h after they awoke, and 97% resumed their usual activities by 24 h. Significant hyperactivity was seen only with pentobarbital and occurred in 8.4% of children over 8 years of age. The multiple-dose regimen of pentobarbital and fentanyl had a significant short-term effect on the children less than 8 years of age, with 35% sleeping longer than 8 h after the MR. Ten children who had needed the multiple-dose pentobarbital regimen or who had failed prior pentobarbital sedation presented for repeat sedation. Midazolam was effective in 9 of these 10 children.

Child, Preschool↗
PubMed1993

Percutaneous gastrojejunostomy versus Nissen fundoplication for enteral feeding of the neurologically impaired child with gastroesophageal reflux.

To determine the optimal method of providing enteral feeding to neurologically impaired children with gastroesophageal reflux, Nissen fundoplication with simultaneous gastrostomy tube placement (NGT) was compared with anterograde percutaneous gastrojejunostomy (APGJ), a nonsurgical procedure performed under fluoroscopic guidance. The records of 112 neurologically impaired children with gastroesophageal reflux were retrospectively reviewed; 68 had undergone NGT and 44 APGJ. Follow-up data were available for 45 NGT patients (mean age, 6.4 years) and 34 APGJ patients (mean age, 7.9 years). Mean follow-up was 1.8 years in the NGT group and 2.5 years in the APGJ group. Complications resulting from either procedure were classified either as major, which included treatment failures or morbidity resulting in prolonged hospitalization, or as minor, those requiring outpatient treatment only or not directly caused by the procedure. The NGT group had a significantly higher incidence of major complications in comparison with the APGJ group (33.3% vs 11.8%, p < 0.05). Ten patients (22.2%) in the NGT group required reoperation for complications; six required a second NGT for wrap hernia, failure, and continued gastroesophageal reflux. Two patients (5.9%) in the APGJ group required surgery for complications; one of these eventually required an NGT, and the other had an intussusception that necessitated a small-bowel resection. Minor complications were more common in the APGJ group than in the NGT group (44.1% vs 6.6%); the majority of complications were related to the jejunostomy tube. Premature replacement or reinsertion of the jejunostomy tube was necessary in 14 APGJ patients (32%). The mortality rate was 8.8% in the NGT group and 5.9% in the APGJ group (p = not significant). No death occurred within 30 days of either procedure. We conclude that APGJ is a safe alternative method for feeding the neurologically impaired child with gastroesophageal reflux.

Adolescent↗
PubMed1991

Real-time US guidance during renal biopsy in children: a different approach. Technical note.

To minimize procedural failures and complications, a real-time ultrasound (US) approach was developed for percutaneous renal biopsy in the pediatric population. With use of a 3- or 5-MHz transducer, the medial border of the kidney is localized and a line, which parallels the renal axis, is drawn on the skin. The lower pole and renal hilum are identified, and lines are drawn perpendicular to the long axis. After the patient is sedated, the entry site is selected above the lower pole. The transducer is placed on the child's side in an oblique transverse plane parallel to the axis of the kidney, the needle is guided into the renal cortex, and a specimen is obtained. Sixty-five biopsies were performed in 63 children. Fifty-five specimens were obtained from native kidneys. Success was achieved in all cases with only three minor complications. This approach appears to be an easy, safe, and accurate guide for renal biopsy in the pediatric population.

Adolescent↗
PubMed1991

Pediatric interventional radiology.

Hydrostatic reduction of intussusception has, until recently, been accomplished using barium sulfate or meglumine sodium diatrizoate, and has resulted in successful reduction in up to 80% of cases. Pneumatic reduction is an old technique but is new to North America. In a short time, air reduction has been widely accepted. It is easy to perform and success is achieved in over 80% of cases. The advantages of pneumatic reduction include a lower cost, shorter procedure time, and if perforation occurs, there is a lower likelihood of fecal contamination of the peritoneum. The vein of Galen malformation was initially described in 1895. The age at which symptoms occur and the severity of the clinical syndrome depend on the magnitude of arteriovenous shunting. Cross-sectional imaging techniques are helpful for diagnosis and management planning. In infants with high-output congestive heart failure, neurointervention is now the treatment of choice.

Cerebral Angiography↗
PubMed1990

Percutaneous transgastric drainage of the lesser sac in children.

In four children (5-14 years old), lesser sac fluid collections (3 pseudocysts and 1 abscess) were externally drained using a percutaneous transgastric approach. With ultrasound or CT guidance and fluoroscopic monitoring, a sheathed needle is inserted through the stomach into the lesser sac fluid collection, the catheter is exchanged, secured in place and connected to external drainage. All four fluid collections were complications of pancreatitis (3 acute post-traumatic, 1 post-surgical). All four fluid collections were successfully drained without need for surgical intervention. There were no major complications. Three minor complications occurred as a result of reinsertion of catheters: transient gastric venous bleeding, hematuria, and bleeding into the pseudocyst. Percutaneous transgastric drainage can be performed successfully in children, and provides an alternative to surgical intervention of lesser sac fluid collections. Drainage early in the course of pancreatic pseudocysts may lessen the morbidity, potential mortality, and prolonged hospitalization usually necessary for standard medical and surgical management of these patients.

Abscess↗