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Biomedical subjects

L Baert

Publications and source records attributed to L Baert.

At least 163 records · Page 9Linked to original sources
PubMed1991

Acquired cystic disease of the kidney analyzed by microdissection.

Four cases of acquired cystic disease of the kidney (ACDK) were studied by the microdissection technique (MD) of Darmady and Baert to analyze the cystic transformation. No patient had a history or clinical evidence of the adult polycystic disease of the kidney (APDK). Hypothetical models related the pathogenesis of cystic transformation to either obstructive or degenerative factors. Microdissection was performed in four nephrectomy specimens of hemodialyzed patients and a total of 155 nephrons were isolated. The atrophy of the glomeruli has already been described histopathologically but MD demonstrated the existence of nephrons consisting of sclerotic glomeruli and enlarged segments between the atrophic convoluted proximal and distal tubules. Diverticula and cysts were located, above all along the proximal (mainly dilated) convoluted tubules: they were always in continuity with the tubules. Phase contrast microscopy showed a patent lumen in 80% of the proximal and distal convoluted tubules, and a regular lining of the cysts. These data support the hypothesis that ACDK is the result of hyperplasia and dilation of remaining nephrons, rather than a result of obstruction and/or fibrosis.

Adult↗
PubMed1991

The percutaneous operative gastrostomy for gastric decompression in major urological surgery.

When postoperative gastric decompression is necessary a percutaneous gastrostomy tube is an alternative to nasogastric intubation. The percutaneous insertion of a suprapubic bladder catheter is an easy procedure without notable complications that increases the comfort of the patient in the immediate postoperative period. We advocate its use in all major urological abdominal operations.

Aged↗
PubMed1991

Interstitial temperature measurements during transurethral microwave hyperthermia.

Microwave hyperthermia is presently being investigated as a treatment for alleviating the symptoms of urinary outlet obstruction associated with benign prostatic hyperplasia. Two clinical techniques using intracavitary microwave applicators are being evaluated for safety and efficacy at various institutions. The transrectal technique uses a directional microwave radiator that is inserted into the rectum adjacent to the prostate. The transurethral approach uses a symmetrically radiating applicator located within the prostatic urethra. Transrectal prostatic heating techniques require surface cooling to prevent hazardous temperatures in the intervening rectal mucosa. Since transurethral applicators radiate from within the prostatic urethra, heating is confined to the obstructive tissue immediately surrounding the applicator. Concern has been expressed regarding the possibility of thermal injury to the prostate and adjacent rectum during transurethral hyperthermia treatment. In this report we present interstitial temperature measurements of prostatic and rectal temperatures in 5 patients. Temperature was observed to decrease at a rate of about 6C/cm. outward from the applicator. No clinically significant temperature increase was observed beyond 1 cm, outside the prostatic capsule or in the rectal mucosa.

Aged↗
PubMed1991

High energy pulsed dye laser lithotripsy: management of ureteral calcium oxalate monohydrate calculi.

High energy pulsed dye laser lithotripsy (Candela MDL-2000), with energy output upgraded to a maximum of 140 mJ. at the laser fiber tip using the 320 mu core fiber, was compared to the initially commercialized device, with the energy output fixed at 60 mJ. using the 200 mu core fiber (Candela MDL-1). A total of 31 treatments in 28 patients was performed with the Candela MDL-1 device. Complete disintegration or at least fragmentation to spontaneously passable fragments occurred in 18 of 31 cases (58%). Only in 11 of the 24 calcium oxalate monohydrate calculi (46%) was fragmentation achieved. Another 73 laser lithotripsies in 72 patients were performed with the Candela MDL-2000 device. Complete disintegration or at least fragmentation to spontaneously passable fragments was achieved in 67 of 73 treatments (92%). Calcium oxalate monohydrate calculi were successfully treated in 41 of 45 procedures (91%). There was no response to the laser treatment in the only cystine calculus.

Adolescent↗
PubMed1991

Electromagnetic extracorporeal shock wave lithotripsy in children.

Extracorporeal shock wave lithotripsy (ESWL) was performed for the treatment of urinary tract calculi in 28 children. All treatments were done with the standard Siemens Lithostar device in situ: no special adaptations for adequate positioning of children are required to target the stone precisely. A total of 42 calculi in 30 renal units was treated, requiring 50 ESWL sessions. The mean energy used was 16.4 kv. and the number of shock waves averaged 3,188. Mean fluoroscopy time per session was 1.5 minutes. In 26 of 50 sessions (52%) general anesthesia was needed for the child to remain perfectly still. A complete stone-free rate was achieved in 38 of 42 calculi (90.5%): after 1 session in 30 (71.4%), after 2 sessions in 6 (13.7%) and after 3 sessions in 2 (4.8%). Five staghorn calculi were treated with ESWL monotherapy. A complete stone-free result was obtained after 3 treatments in 2 patients, while 2 had residual fragments in the lower pole (5 mm. after 6 sessions and 11 months of followup in 1, and 7 mm. after 3 sessions and 3 months of followup in 1). A cystine staghorn stone necessitated open nephrolithotomy after 3 sessions without any fragmentation. One impacted sacroiliac ureteral stone required endoscopic laser lithotripsy. Except for these 2 failures no adjuvant procedures were needed. There were no intraoperative or postoperative complications and minor skin bruising at the coupling site after 3 treatments did not require any therapy. We conclude that electromagnetic ESWL with the standard Lithostar unit is a safe and effective method to treat calculi throughout the urinary tract in children.

Adolescent↗
PubMed1991

Is there a place for conservative surgery in the treatment of renal carcinoma?

Since 1981, 31 patients have undergone conservative surgery for malignant renal tumours and have been followed up for at least 2 years. The techniques included enucleation or resection (wedge resection or partial nephrectomy). In 10 patients the indications for kidney-sparing surgery were absolute, while in the remainder the conservative surgical approach was a deliberate choice. The tumours varied in diameter from 1.3 to 12 cm and no metastases were detected on pre-operative screening. One patient died post-operatively from myocardial infarction. In the remaining 30 there were no local recurrences. Two patients died from skeletal metastases (1 with bilateral malignancy) and 2 underwent surgery in the post-operative period for haemorrhagic complications. The efficacy of conservative surgery in the local control of renal cancer is an argument in favour of its wider use.

Adenocarcinoma↗
PubMed1991

Anaesthesia-free extracorporeal shock wave lithotripsy in patients with renal calculi.

Modern extracorporeal shock wave lithotripsy can be performed with combined ECG and respiratory triggered shock wave release. Disconnecting the ECG triggering increases the risk of ventricular arrhythmias, including potentially malignant ones. The aim of this study was to assess the relationship of any sympatho-adrenal excitation as a possible explanation for the occurrence of cardiac arrhythmia. Plasma catecholamine levels were assessed in 5 patients during and after 50 min of anaesthesia-free extracorporeal shock wave lithotripsy for the treatment of calculi in the upper pole of the left kidney. Venous blood sampling showed no significant increase in catecholamines (epinephrine, norepinephrine and dopamine) during or after treatment. The heart rate and arterial blood pressure were measured simultaneously and showed no significant increase when shock waves were released during ECG triggering. However, when disconnecting the ECG-triggering mode, the incidence of ventricular extrasystoles on Holter monitoring became more apparent during respiratory triggered shock wave release only, although there was no rise in plasma catecholamine levels. These data suggest that cardiac arrhythmias are related to direct and accidental mechanical stimulation of the heart rather than to any sympatho-adrenal discharge during shock wave release.

Anesthesia, General↗
PubMed1991

Experience with the intraprostatic spiral.

Thirty-six patients have been followed up after insertion of an indwelling intraurethral device for prostatic obstruction. Follow-up exceeded 1 year in some cases. The main problem was dislocation of the spiral not only in the early stages but also after several months. Endoscopic assessment of the obstruction seems important during the pre-operative investigations. The ideal indication is prostatic obstruction in patients who are unsuitable for surgery and who need relief of acute retention for a limited time only. In selected patients the prostatic spiral has a place in the treatment of obstructive prostatism.

Catheters, Indwelling↗
PubMed1991

Instrumentation of a gravity feed extruder and the influence of the composition of binary and ternary mixtures on the extrusion forces.

A gravity feed extruder was adapted to monitor the extrusion forces, the temperature during processing and the rotational speed of the extruding cylinders. The extruder was used to evaluate the influence of particle size of insoluble material and of product solubility on the extrusion forces. Microcrystalline cellulose, dicalcium phosphate dihydrate and different lactoses were used as model compounds. Difference in lactose and microcrystalline cellulose particle size did not influence extrusion forces. The amount of water in the mixtures to be processed and the initial difference in solubility for some of the lactose types investigated influenced the extrusion forces dramatically. Extrusion forces recorded during processing of a mixture previously granulated in a high shear granulator were higher than when processed in a planetary mixture. Loss of water during high shear granulation is probably the main cause of this phenomenon.

Calcium Phosphates↗
PubMed1991

Implantation of the urethral stent for treatment of complex urethral strictures. Evaluation of the functional and radiological results.

We describe the results after implantation of a urethral stent in 6 patients with recurrent urethral strictures. Four patients had strictures located in close vicinity to the external sphincter. In 3 of these 4 patients open urethroplasty procedures had failed. The treatment was successful in 5 of the 6 patients with a follow-up of 6-10 months. However, in 1 patient who had a complex stricture close to the sphincter, dense fibrotic strictures recurred at the proximal end of the stent where a short segment of the stricture was left uncovered in order to preserve continence. We conclude that implantation of the stent is a valuable treatment for complex strictures in the vicinity of the sphincter on condition that the stent covers the whole stricture.

Aged↗
PubMed1991

Balloon dilation of the prostate. Critical evaluation.

We describe the results of prostatic balloon dilation in 7 patients with a follow-up of 9 months. Symptom scores dramatically fell in 5 patients (success rate 71%), which is confirmed by a significant improvement in peak flow in 4 of them. Two patients failed to improve and needed a subsequent intervention which revealed a stage A2 prostatic carcinoma in one. During subsequent open prostatectomy, a condition analogous to dilation with the Deisting dilator was seen. We conclude that the indications and results obtained with the balloon dilator are similar to those with the Deisting dilator.

Aged↗
PubMed1991

Anesthetic requirements during electromagnetic extracorporeal shock wave lithotripsy.

An important aspect of modern extracorporeal shock wave lithotripsy is the ability to perform the procedure without anesthesia. Between June 1987 and April 1990, a total of 7,500 treatments were performed in our Lithotripsy Unit, using the Lithostar (Siemens AG, Erlangen, FRG): moreover 80% of the treatments were carried out as an anesthesia-free outpatient service. All treatments were reviewed for anesthetic requirements. Epidural anesthesia was performed in 74/7,500 (0.98%) treatments: during the initial period, the first 70 procedures were systematically performed under epidural anesthesia, and in 4 later cases of simultaneous endoscopic stone manipulation. Local skin infiltration was applied at the coupling site in 658/7,500 (8.7%) treatments. With increasing experience and technological improvement, 6,229/7,500 (83%) procedures were performed later on with only mild sedation: 1 mg of lorazepam orally 30 min before the treatment. Intravenous sedation was required in 510/7,500 (6.8%) cases because of painful local irritation, especially when treating calculi close to sites where shock waves can progress along the ribs. General anesthesia was required in all 28 children (0.4%).

Adult↗
PubMed1991

Extracorporeal shock wave lithotripsy in situ treatment for ureteral stones.

Three hundred and sixteen patients with ureteral stones were treated in situ (without retrograde stone manipulation) with and without stent bypass (DJ stent, ureteral catheter). Results were generally better with stent bypass, but only marginally so for stones larger than 10 mm in diameter. Regardless of whether or not the ureter was stented, lower ureteral stones were more difficult to fragment than upper ureteral stones and pre-sacral stones did not respond well to in situ treatment. We observed that evaluation of stone disintegration and fragment evacuation could only be properly assessed after approximately 3 weeks post-ESWL.

Adolescent↗