PubMed Health⌕ Search

Biomedical subjects

J Kestle

Publications and source records attributed to J Kestle.

18 recordsLinked to original sources
PubMed2000

The patterns of late deterioration in patients with transitional lipomyelomeningocele.

INTRODUCTION: Tethering is assumed to be the primary cause of deterioration seen in children with transitional lipomyelomeningocele as they age. The inevitability of deterioration has led to recommendations for prophylactic interventions to stabilize or prevent further clinical deterioration. OBJECTIVE: Determine the frequency and patterns of functional deterioration observed after successful untethering in patients with transitional lipomyelomeningocele and compare functional outcomes with what is known regarding untreated patients. METHODS: Fifty patients having transitional LMMC, treated at a single institution and followed in a multidisciplinary clinic were retrospectively reviewed to determine their clinical status prior to untethering, and the time to development of new symptoms or signs following untethering. RESULTS: 82% of patients were diagnosed and 78% underwent untethering prior to one year of age. All patients had a cutaneous lumbosacral lipoma, 22 patients were considered normal at presentation and 28 showed abnormalities on clinical examination. Forty-nine patients were untethered successfully and all were available for follow-up ranging from 2 to 138 months (mean 39 months). Acute morbidity was limited to transient neurogenic bladder dysfunction and minor wound complications. Late clinical deterioration occurred in the majority of patients. Orthopedic and neurological deterioration occurred over the first 60 months following untethering and urological deterioration occurred thereafter. CONCLUSIONS: Functional loss after untethering is common and the pattern of loss is likely a reflection of the ability to detect abnormalities in this infant population. Untethering does not usually result in permanent acute morbidity, and does not prevent longer-term functional deterioration. The ratio of asymptomatic to symptomatic patients at follow-up in this operative series is similar to age-matched historical series of untreated patients.

British Columbia↗
PubMed2000

The initial treatment of hydrocephalus: an assessment of surgeons' preference between third ventriculostomy and shunt insertion.

Third ventriculostomy is an option for patients who have traditionally received a ventriculoperitoneal shunt. This study has been conducted to determine: 1. How common is third ventriculostomy as the initial treatment of hydrocephalus? 2. Does the frequency of third ventriculostomy vary among surgeons? 3. What factors influence surgeons' decision to choose third ventriculostomy? Surgeons completed a questionnaire addressing patient selection and technique factors. Nine case scenarios were reviewed by surgeons who were then asked to choose a ventriculoperitoneal shunt or a third ventriculostomy as the initial treatment. Forty-three responses were received. The proportion of new patients treated with third ventriculostomy varied widely (0%-100%, median 13%). This was not related to years in practice, type of training or presence of residents/fellows. Factors that increased the chance of a third ventriculostomy were triventricular hydrocephalus on CT/MR, isolated aqueduct stenosis, thin ballooned floor and tectal tumor. Factors that decreased the chance of a third ventriculostomy were dilated subarachnoid spaces, meningitis and head injury. The presence of myelomeningocele or age < 1 year were less likely to influence the choice of operation. Variation in the rate of third ventriculostomy as the first treatment for hydrocephalus is large. It is unlikely that this degree of variation can be explained by differences in patient populations. Further work to refine and disseminate the indications for third ventriculostomy is warranted.

Cerebrospinal Fluid Shunts↗
PubMed2000

Pediatric peri-insular hemispherotomy.

A number of surgical procedures are available for patients with epilepsy associated with diffuse hemispheric disorders. In this report, 16 pediatric patients had hemispherectomy: 5 underwent hemidecortication and 11 had peri-insular hemispherotomy. The clinical records were retrospectively reviewed, and the results and complications of the procedures were documented. The procedure was feasible in very young children and in the absence of ventriculomegaly.

Adolescent↗
PubMed2000

Axillary nerve injuries in children.

Isolated axillary nerve injury is uncommon, particularly in children. The motor deficit of shoulder abduction may not recover spontaneously and can be a substantial handicap. Detection may be difficult initially, as the injury is masked by trauma such as head injury, and concomitant shoulder injury requiring immobilization. After mobilization, patients learn to partially compensate by using alternate muscles. There are few reports of surgical management of this nerve injury. Most concern predominantly adults, and the results are mixed with on average slightly greater than half having a good recovery (defined as grade 4-5 Medical Research Council muscle power). We present our experience with 4 pediatric patients who had axillary nerve injury. Three patients had an interposition nerve graft, and 1 patient underwent neurolysis. All patients recovered to grade 4-5 deltoid muscle power. Children with an axillary nerve injury which fails to recover spontaneously by 4-6 months should strongly be considered for surgical exploration.

Adolescent↗
PubMed2000

Long-term follow-up data from the Shunt Design Trial.

BACKGROUND: A previously reported multicenter randomized trial assessed whether 2 new shunt valve designs would reduce shunt failure rates compared to differential pressure valves. The study did not show a significant difference in the time to first shunt failure. Patients entered the trial between October 1, 1993, and October 31, 1995. The primary results were based on the patients' status as of October 31, 1996 (a minimum follow-up of 1 year). This report describes the late complications based on the patients' most recent follow-up. METHODS: Three hundred and forty-four hydrocephalic children at 12 North American and European centers were randomized to 1 of 3 valves: a standard differential pressure valve; a Delta valve (PS Medical-Medtronic) or a Sigma valve (NMT Cordis). Patients were followed until their first shunt failure. Shunt failure was defined as shunt surgery for obstruction, overdrainage, loculation or infection. If the shunt did not fail, follow-up was continued until August 31, 1999. RESULTS: One hundred and seventy-seven patients had shunt failure. Shunt obstruction occurred in 131, overdrainage in 13, loculated ventricles in 2 and infection in 29. The overall shunt survival was 62% at 1 year, 52% at 2 years, 46% at 3 years, 41% at 4 years. The survival curves for the 3 valves were similar to those from the original trial and did not show a survival advantage for any particular valve. CONCLUSIONS: Prolonged follow-up to date does not alter the primary conclusions of the trial: there does not appear to be one valve that is clearly the best for the initial treatment of pediatric hydrocephalus.

Adolescent↗
PubMed1999

Efficacy and complications of morphine infusions in postoperative paediatric patients.

The aim of the study was to evaluate the efficacy and the incidence of clinically significant adverse drug reactions (ADRs) in paediatric patients receiving continuous intravenous morphine infusions for acute postoperative pain. Definitions were established for ADRs and data were collected in an immediately retrospective fashion for a maximum of 72 h in 110 patients >/=5 three months of age (0.3-16.7 years) receiving morphine infusions and admitted to a general ward over a three month convenience sampling period. Inadequate analgesia occurred in 65.5% of patients during the first 24 h of therapy and occurred most frequently in patients with infusion rates of 20 microg.kg-1.h-1 or less. Nausea/vomiting was the most commonly experienced ADR (42.5%). The incidence of respiratory depression was 0% (95% CI=0-3.3%). Other ADRs included: urinary retention (13.5%), pruritus (12.7%), dysphoria (7.3%), hypoxaemia (4.5%), discontinuation of morphine for treatment of an ADR (3.6%), and difficulty in arousal (0.9%). The most common ADRs associated with morphine infusions were inadequate analgesia (in the first 24 h) and nausea/vomiting. There were no cases of respiratory depression. Methods of avoiding initial inadequate analgesia and treating nausea and vomiting associated with morphine infusions are needed.

Acute Disease↗
PubMed1999

Change in ventricular size and effect of ventricular catheter placement in pediatric patients with shunted hydrocephalus.

OBJECTIVE: The multicenter, randomized pediatric cerebrospinal fluid shunt valve design trial found no difference in the rate of shunt failure between a standard valve, a siphon-reducing valve (Delta; Medtronic PS Medical, Goleta, CA), and a flow-limiting valve (Orbis Sigma; Cordis, Miami, FL); however, the valves were expected to have different effects on ultimate ventricular size. Also, the catheter position or local environment of the ventricular catheter tip might have affected shunt failure. Therefore, we performed a post hoc analysis to understand what factors, other than valve design, affected shunt failure and to identify strategies that might be developed to reduce shunt failure. METHODS: Ventricular size was measured at as many as six different intervals, using a modified Evans' ratio (with incorporation of the frontal and occipital dimensions), in 344 patients. Ventricular catheter location was defined as being in the frontal horn, occipital horn, body of the lateral ventricle, third ventricle, embedded in brain, or unknown. The ventricular catheter tip was described as surrounded by cerebrospinal fluid, touching brain, or surrounded by brain parenchyma within the ventricle (slit ventricle). Repeated measures analysis of variance for unbalanced data was used to analyze ventricular size. A Cox model (with incorporation of time-dependent covariates) was used to evaluate the contribution of age, etiology, shunt design, ventricular size, ventricular catheter location, and environment among the cases. RESULTS: Ventricular volume decreased in an exponential fashion, forming a plateau at 14 months, and was similar for the three valves (P = 0.4). Frontal and occipital ventricular catheter tip locations were associated with a reduced risk of shunt failure (hazard ratios, 0.60 [P = 0.02] and 0.45 [P = 0.001], respectively). Ventricular catheter tips surrounded by cerebrospinal fluid or touching the brain were associated with a reduced risk of failure (hazard ratios, 0.21 and 0.33, respectively; P = 0.0001). Patients with myelomeningocele or large ventricles had increased risk of malfunction (hazard ratios, 1.78 [P = 0.006] and 2.33 [P = 0.03], respectively). CONCLUSION: Decline of ventricular size over time is not affected by these different shunt valve designs. This suggests that the mechanical models of hydrocephalus on which the designs were based are inadequate. Ventricular catheter tip location and ventricular catheter environment are important. Techniques to accurately place ventricular catheters and new valve designs that effectively control ventricular size might reduce shunt malfunction.

Catheters, Indwelling↗
PubMed1999

An assessment of observer bias in the shunt design trial.

INTRODUCTION: An international multicenter randomized trial comparing standard pressure differential valves, Orbis Sigma valves and PS Medical Delta valves, for children with newly diagnosed hydrocephalus failed to show a difference in the time to first shunt failure (power 80%). In order to avoid observer bias, the primary endpoint, shunt failure, was defined by detailed clinical and radiological criteria. Surgeons notified the data center when their patient reached endpoint. Their decision was blindly reviewed by a centralized adjudication process. The current analysis asks: (1) Did the surgeons and the blinded adjudication process agree on the presence of shunt failure? (2) Do the shunt survival curves change when the surgeons' assessment of outcome is used? METHODS: The two methods of outcome assessment (surgeons' decision and adjudication process) were compared with a kappa statistic for the presence of shunt failure and a log rank statistic for time to shunt failure. RESULTS: The surgeon and the adjudication process agreed on the presence of the primary outcome in 313/344 patients in the trial (kappa = 0.81). The 31 cases of disagreement were evenly distributed among the three shunts. The survival curves generated from the surgeons' decision were not significantly different from those generated by the adjudication process (log rank = 0.70, p = 0.37) and did not alter the study conclusions. DISCUSSION: Observer bias in the assessment of outcome is always a concern in an unblinded clinical trial such as this one. We did not detect an observer bias of sufficient magnitude to alter the study conclusions.

Child↗
PubMed1999

The shunt design trial: variation in surgical experience did not influence shunt survival.

INTRODUCTION: An international multicenter randomized trial comparing standard pressure differential valves, Orbis Sigma valves and PS Medical Delta valves for children with newly diagnosed hydrocephalus failed to show a difference in the time to first shunt failure. Surgeons' prior experience with the three valves varied. This analysis was performed to assess whether lack of surgical experience with any of the valves could explain the overall negative result. METHODS: (1) Shunt survival was compared at high- and low-volume centers. (2) The 1-year shunt survival rates (+/-95% confidence interval) for patients entered in the first quarter and the last quarter of the 25-month accrual period were compared (for all patients, and for each shunt). RESULTS: Survival curves for high- and low-volume centers were similar. Ninety of the 344 randomized patients were accrued in the first quarter and 93 in the last quarter. The 1-year shunt survival for all patients entered in the first quarter was 72% (+/-11%) compared to 64% (+/-10%) for patients entered in the last quarter. The shunt-specific results were 66% (+/-20%) compared to 54% (+/-20%) for Delta valve patients, 75% (+/-20%) compared to 70% (+/-17%) for standard valve patients and 76% (+/-18%) compared to 66% (+/-16%) for Orbis Sigma patients. DISCUSSION: Shunt survival did not improve as surgeons accumulated experience over the course of the study. Although participating surgeons had varying levels of experience with the different shunts at the start of the trial, this does not appear to explain the overall negative trial result.

Adult↗
PubMed1997

Effect of hyperventilation on regional cerebral blood flow in head-injured children.

OBJECTIVES: To study cerebral blood flow and cerebral oxygen consumption in severe head-injured children and also to assess the effect of hyperventilation on regional cerebral blood flow. DESIGN: Prospective cohort study. SETTING: Pediatric intensive care unit at a tertiary-level university children's hospital. PATIENTS: Twenty-three children with isolated severe brain injury, whose admission Glasgow Coma Scores were <8. INTERVENTIONS: PaCO2 was adjusted by altering minute ventilation. Cerebral metabolic measurements were made at three levels of PaCO2 (>35, 25 to 35, and <25 torr [>4.7, 3.3 to 4.7, and <3.3 kPa]) after allowing 15 mins for equilibrium. MEASUREMENTS AND MAIN RESULTS: Thirty-eight studies (each study consisting of three sets of measurements at different levels of PaCO2) were performed on 23 patients. At each level of PaCO2, the following measurements were made: xenon-enhanced computed tomography scans; cerebral blood flow; intracranial pressure; jugular venous bulb oxygen saturation; mean arterial pressure; and arterial oxygen saturation. Derived variables included: cerebral oxygen consumption; cerebral perfusion pressure; and oxygen extraction ratio. Cerebral blood flow decreased below normal after head injury (mean 49.6 +/- 14.6 mL/min/100 g). Cerebral oxygen consumption decreased out of proportion to the decrease in cerebral blood flow; cerebral oxygen consumption was only a third of the normal range (mean 1.02 +/- 0.59 mL/min/100 g). Neither cerebral blood flow nor cerebral oxygen consumption showed any relationship to time after injury, Glasgow Coma Score at the time of presentation, or intracranial pressure. The frequency of one or more regions of ischemia (defined as cerebral blood flow of <18 mL/min/100 g) was 28.9% during normocapnia. This value increased to 73.1% for PaCO2 at <25 torr. CONCLUSIONS: Severe head injury in children produced a modest decrease in cerebral blood flow but a much larger decrease in cerebral oxygen consumption. Absolute hyperemia was uncommon at any time, but measured cerebral blood flow rates were still above the metabolic requirements of most children. The clear relationship between the frequency of cerebral ischemia and hypocarbia, combined with the rarity of hyperemia, suggests that hyperventilation should be used with caution and monitored carefully in children with severe head injuries.

Adolescent↗
PubMed1997

A randomized clinical trial to compare selective posterior rhizotomy plus physiotherapy with physiotherapy alone in children with spastic diplegic cerebral palsy.

A randomized controlled single-blind trial was performed to compare lumbo-sacral selective posterior rhizotomy (SPR) followed by intensive physiotherapy, with intensive physiotherapy alone in improving motor function in children with spastic diplegic cerebral palsy. Fifteen patients were randomly assigned to each treatment modality. Patients in the SPR group had rhizotomy within 1 month, followed by intensive outpatient physiotherapy for 9 months. Patients assigned to physiotherapy alone had identical intensive physiotherapy. There was a statistically significant and clinically important difference in improvement in motor function in favor of the SPR group, with a mean increase in total Gross Motor Function Measure (GMFM) score of 11.3% at 9 months for the SPR group compared with 5.2% for the physiotherapy-only group (P = 0.007). Significant improvements in spasticity (P < 0.001) and range of movement (P < 0.001) were noted in the SPR group compared to the physiotherapy-only group. The results indicate that the improvement in motor function after SPR is more than can be explained by the associated intensive physiotherapy.

Cerebral Palsy↗
PubMed1996

A randomized trial to assess the efficacy of surgery in addition to radiotherapy in patients with a single cerebral metastasis.

BACKGROUND: Cerebral metastasis is a common oncologic problem that occurs in 15-30% of cancer patients; approximately half such metastases are single. Previous retrospective studies and two randomized trials reported that the addition of surgical extirpation prior to radiation therapy increased survival, neurologic function, and quality of life compared with radiation alone in patients with a single brain metastasis. METHODS: A randomized controlled trial was conducted in which patients with a single brain metastasis were allocated to undergo radiation alone or surgery plus radiation. Radiation consisted of 3000 centigray to the whole brain in 10 fractions. RESULTS: Forty-three patients received radiation alone and 41 patients surgery plus radiation. All but two of the study patients died. No difference in survival was detected between the groups; the median survival for the radiation group was 6.3 months (95% confidence interval, 3-11.4) compared with 5.6 months for the surgery plus radiation group (95% confidence interval, 3.9-7.2) (P = 0.24). Most patients died within the first year (69.8% in the radiation arm vs. 87.8% in the surgery plus radiation arm). There were no significant differences in the 30-day mortality, morbidity, or causes of death. Extracranial metastases was an important predictor of mortality (relative risk, 2.3). The mean proportion of days that the Karnofsky performance status was > or = 70% did not differ between the 2 groups. CONCLUSIONS: This trial failed to demonstrate that the addition of surgery to radiation therapy improved outcome of patients with a single brain metastasis. Thus, the efficacy of surgery plus radiation compared with radiation alone needs to be addressed by further clinical trials and/or a meta-analysis.

Brain Neoplasms↗
PubMed1996

Rationale and methodology of the multicenter pediatric cerebrospinal fluid shunt design trial. Pediatric Hydrocephalus Treatment Evaluation Group.

Cerebrospinal fluid shunt failure remains a common and at times overwhelming problem in pediatric patients with hydrocephalus. Two new shunt valve designs, the Orbis-Sigma (Cordis Corporation, Miami, Florida) and the Delta valve (PS Medical, Goletta, California), have flow/pressure characteristics dramatically different from those of standard differential pressure valves which have been used for over three decades. Both new designs reduce the siphoning effect in the upright position, and have been reported to reduce shunt failure rates in uncontrolled series, allegedly due to reduction in shunt overdrainage. Most mechanical shunt failure in the first 2 years after implantation is due to proximal shunt obstruction, overdrainage, and loculated ventricles. By reducing the incidence of slit ventricles associated with standard valves, both new designs could be envisioned as reducing the early mechanical complications. The improved results with both new valves could, however, also be to a large extent due to other confounding effects of shunt surgery, including patient selection, surgical technique, and specific configuration of the components of the shunt other than the valve. There are also theoretical reasons why these valve designs might be worse than their predecessors, including the narrow orifice and high resistance of the Orbis-Sigma, and the flexible membrane of the siphon control portion of the Delta valve, which may increase the ventricular pressure in the upright position or become blocked by encasing scar tissue. For this reason a randomized trial is required to determine efficacy, and a standard differential pressure valve is required as the control design. A significant reduction in early shunt failure would dramatically improve the morbidity and mortality of pediatric hydrocephalic patients, as well as providing substantial savings to the health care system. Failure to determine any difference would focus attention on other issues surrounding shunt surgery, such as patient characteristics or surgical technique.

Cerebrospinal Fluid Shunts↗
PubMed1996

Effect of macular edema on surgical visual outcome in eyes with idiopathic epiretinal membrane.

OBJECTIVE: To determine whether macular edema affects the surgical outcome in eyes with idiopathic epiretinal membrane. DESIGN: Case series. SETTING: University-based referral practice in Vancouver. PATIENTS: Sixty-one patients (63 eyes) (37 women and 24 men ranging in age from 47 to 96 [mean 70] years) who underwent pars plana vitrectomy with membrane peeling for idiopathic epiretinal membrane. OUTCOME MEASURES: Degree of macular edema on preoperative fluorescein angiograms (none, mild or severe), as rated independently by two masked observers, and preoperative and postoperative Snellen visual acuity. RESULTS: Of the 63 eyes 32 had no macular edema, 21 had mild edema, and 10 had severe edema. Fifty-two eyes (83%) had an improvement in visual acuity. The mean number of lines of improvement in visual acuity for the three groups was 2.2, 3.7 and 2.6 respectively. Multiple regression analysis showed that the factor with the greatest adverse effect on visual outcome was intraoperative macular hole formation. The presence of macular edema preoperatively did not significantly affect visual outcome. CONCLUSIONS: Our results suggest that even eyes with significant macular edema secondary to idiopathic epiretinal membranes may benefit from vitrectomy with membrane peeling.

Aged↗
PubMed1995

Model for the cost analysis of shunted hydrocephalic children.

This paper describes a model for forecasting the treatment costs for hydrocephalic patients with ventriculoperitoneal shunts. Modeling with institution-specific or reported failure rates allows the prediction of shunt failure in real and/or theoretical populations. The addition of costing factors (derived from hospitalization, operative and drug costs) to the model allows the derivation of partial or total cost estimates. The effects of varying the failure rate, infection rate, number of new patients, number of lost patients and costing factors can be simulated and measured. Basing this model on data from our institution, decreasing the rate of failure during the first year following shunt insertion or revision has the potential for greater cost savings over time than either decreasing the shunt infection rates or the duration of hospital stay. By combining shunt performance and financial data, an estimate of the cost of the treatment of a population with hydrocephalus, over time, can be derived. These data can be critical for institutional and program budgeting and serve as an estimate of the economic effects of treatment changes proposed in clinical trials.

Child↗