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H N Whitfield

Publications and source records attributed to H N Whitfield.

At least 55 records · Page 3Linked to original sources
PubMed1992

Prediction of response to lithotripsy--the use of scanning electron microscopy and X-ray energy dispersive spectroscopy.

A single urine sample was obtained from each of 38 patients before and immediately after treatment with a Wolf Piezolith 2300. Each sample was analysed for crystals using scanning electron microscopy and X-ray energy dispersive spectroscopy. In all cases it was possible to make a stone diagnosis prior to treatment and there was 100% correlation between the pre- and post-treatment diagnosis. All stones smaller than 90 mm2 on plain X-ray cleared with piezoelectric lithotripsy alone, regardless of composition. Larger stones composed of calcium oxalate were all successfully fragmented, but 5 of 15 mixed or phosphate stones failed to respond.

Adolescent↗
PubMed1991

Detubularisation in cystoplasty: clinical review.

Cystoplasty using a detubularised bowel segment is preferable to using a tubularised length of intestine. This has been shown experimentally to result in a reduction in the contractility of the neobladder, although contractions are not completely abolished. Incontinence, especially nocturnal, may still be a problem. Assessment of renal function has shown a marked incidence of upper tract dysfunction despite detubularisation. All patients remain at risk of upper tract obstruction following cystoplasty. Because bowel contraction waves are brought on by distension, it may be possible either to postpone or to prevent the onset of contractions by avoiding an excessive build-up of bladder volume. Clean intermittent self-catheterisation is an efficient means of emptying the bladder, although sphincter rebalancing may also be required.

Adult↗
PubMed1991

Diagnostic and surgical aspects of renal carcinoma with involvement of the inferior vena cava.

Over the past 10 years, 13 patients presented with operable renal carcinoma and tumour extension within the inferior vena cava. This was diagnosed accurately in all but 1 patient, using ultrasound. Radical nephrectomy with removal of tumour within the inferior vena cava was performed in all 13 cases, 2 requiring cardiac bypass. There were no operative deaths and 6 patients remain alive and well with a mean follow-up of 2 years. The presence and level of vena caval extension did not appear to have an adverse affect on prognosis.

Adult↗
PubMed1990

Computerisation of urothelial carcinoma records: 16 years' experience with the TNM system.

Details of 554 patients with urothelial carcinomas have been recorded on computer forms between 1973 and 1988 inclusive. Essential information from initial assessment and follow-up examinations was printed out on specially designed urothelial update sheets, copies of which were given to patients and urologists as well as being filed in the hospital notes. The survival status of all patients was established as accurately as possible in the last 2 years of the study. Multivariate analysis of 462 bladder cancer patients with adequate follow-up indicated that T category was the most important discriminating variable, followed by histological grade. After replacing T category by microscopic depth of invasion and bimanual examination, the latter was found to be the most important single variable. The omission of the findings on bimanual examination from the 1987 revision of the TNM classification therefore appears to be wrong.

Aged↗
PubMed1990

Cystoplasty: tubularisation or detubularisation?

Previous studies on substitution or augmentation cystoplasty have highlighted the profusion of surgical techniques available, but there is disagreement as to which is the best. We established an animal model to compare various types of cystoplasties, tubularised and detubularised, using ileum and caecum. Detubularisation did not abolish intrinsic bowel contractions but delayed their onset. No differences were noted in the frequency and amplitude of such contractions after detubularisation or between large and small bowel cystoplasties. Although intravenous urography did not demonstrate any abnormality in upper tract anatomy, a significant number of animals had some functional disturbance of the kidney after cystoplasty demonstrable on isotope renography, irrespective of the surgical technique. It may be possible to prevent these contractions with their associated harmful effects by preventing the bladder volume from building up excessively.

Animals↗
PubMed1989

Clinical experience using the Wolf Piezolith device at 2 British stone centers.

Machines using the principle of piezoelectric extracorporeal shock wave lithotripsy have been developed. This has allowed the prospect of painless treatment for renal and ureteral calculi. The experience with use of 2 Wolf Piezolith machines for 1 year is presented. Different second generation lithotriptors have varying techniques of production of shock waves and different imaging methods. The Wolf Piezolith device uses ultrasound imaging and piezoelectric crystals for shock wave generation. Between June 1987 and May 1988, 545 patients 5 to 84 years old were treated with the Wolf Piezolith device. Of these patients 2-month followup data are available for 367 (398 renal units). Outpatient treatment was used routinely. For renal calculi complete fragmentation (into particles less than 2 mm. in size) was achieved in 94 per cent of the patients, with 53 per cent being completely free of stone at 2 months. For ureteral stones treated in situ the best results were obtained in the upper and lower ureter. Over-all, 62 per cent of the patients required more than 1 treatment, with the number of treatment sessions required increasing with the size of the stone treated. Morbidity was low. Ultrasound imaging has proved to be as effective as x-ray imaging. Compared to Dornier HM-3 lithotripsy, installation and running costs were low. The machine offers a favorable alternative to first generation lithotriptors.

Adolescent↗
PubMed1989

Irrigation and acute ureteric dilatation--as for ureteroscopy.

The effects of irrigation with sterile and infected saline after acute ureteric dilatation by graded Teflon dilators were evaluated renographically and histologically in minipigs. The minipig ureter was dilated from its normal calibre of 4 F to 10 F, and 100 ml of sterile or infected saline were then introduced from a height of 60 cm under gravity. One week after irrigation and dilatation the ipsilateral kidney was either functioning less than 10% or there was an obstructive nephropathy. Histology at 3 months suggested that extravasation of infected irrigating fluid was the most likely cause of ureteric stricture formation.

Animals↗
PubMed1989

Biofilms, bacteria and bladder catheters. A clinical study.

Biofilms were present on 16 of 33 urethral catheters examined. In 11 cases the catheter carried a different microbial flora from that of the bladder urine. The length of time the catheter was in situ did not influence biofilm formation, and all types of materials tested supported biofilm growth. Biofilms were seen on 2 of the 7 catheters where prophylactic antibiotics had been used.

Bacteria↗
PubMed1989

Plasma lignocaine levels during transurethral prostatectomy.

It has been reported that transurethral absorption of lignocaine may cause systemic toxicity when associated with mucosal damage within the urethra. We measured the serum levels of lignocaine in 30 patients after the transurethral administration of 400 mg lignocaine gel just before transurethral prostatectomy. In 11 patients additional lignocaine was given as part of the anaesthetic induction (Group A). In 19 patients no additional lignocaine was given (Group B). Two patients in Group A and three patients in Group B also underwent Otis urethrotomy. The mean peak plasma lignocaine concentration as measured by sequential venous samples was 1424 ng/ml in Group A and 72 ng/ml in Group B. We conclude that 400 mg lignocaine gel applied endourethrally before transurethral resection of the prostate results in plasma concentrations well below the toxic levels.

Aged↗
PubMed1988

The steinstrasse: a legacy of extracorporeal lithotripsy?

32 steinstrasse formations in the first 600 extracorporeal shockwave lithotripsy treatments required intervention. Their radiological appearance has been classified into 3 types and the aetiology of each type is discussed. 24 cases received a primary needle nephrostomy to relieve obstruction and of these 18 passed spontaneously, 5 required ureteroscopic manipulation and 1 underwent open surgery. Primary ureteroscopic removal was successful in 3 out of 5 cases. 3 upper ureteric steinstrassen were removed by a percutaneous intrarenal approach. A suggested plan of management for complicated steinstrassen is outlined.

Adult↗