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Biomedical subjects

P Dasgupta

Publications and source records attributed to P Dasgupta.

At least 37 records · Page 2Linked to original sources

Prolonging the life of the flexible ureterorenoscope.

The lifespan of medical equipment must be maximised to ensure cost-effectiveness. Flexible ureterorenoscopes have become widely used in the diagnosis and treatment of urolithiasis. They are relatively expensive and current literature shows that they require frequent repair and replacement. We have analysed our data for the number of procedures and repairs required for each new instrument we have used. So far we have used four new flexible ureteroscopes, which have been used for a total of 375 procedures, an average of 94 procedures each. On average each required repair twice. We believe that a few simple precautions taken during use and storage help to maximise the lifespan of the flexible ureterorenoscope and our results would appear to support this.

Durable Medical Equipment↗

Pseudoaneurysm formation after flexible ureterorenoscopy and electrohydraulic lithotripsy.

Although electrohydraulic lithotripsy (EHL) is regularly used to fragment urinary calculi, it has the potential to cause significant renal tract damage. We report a complication of EHL use during flexible ureterorenoscopy, where recovery was complicated by delayed, prolonged haematuria secondary to the formation of a pseudoaneurysm in an interlobar renal artery. Embolisation was achieved by the insertion of a coil.

Adult↗

Percutaneous nephrolithotomy in early pregnancy.

Most cases of urolithiasis in pregnancy are managed conservatively either with ureteric stents or percutaneous nephrostomy tubes, which need to be changed at regular intervals. Definitive management of the stone is usually delayed till after delivery. We describe a patient who presented with pyonephrosis in the fifth week of gestation, due to a stone obstructing the right ureteropelvic junction. This was managed by insertion of a nephrostomy tube. She declined nephrostomy tube/stent changes during the rest of her pregnancy and requested termination as an alternative. She successfully underwent percutaneous nephrolithotomy in the 14th week of pregnancy, with radiation exposure strictly localised to the kidney for 6 s. A healthy male baby was delivered at term.

Adult↗

A systematic review of hand-assisted laparoscopic live donor nephrectomy.

We provide a systematic review of hand-assisted laparoscopic live donor nephrectomy (HALDN), a relatively new procedure. Medline search of HALDN between 1995 and 2002 was conducted. Published studies were scored by two independent assessors using a modified form of 11 generic questions. All questions required one of three responses: 0--criterion not reported, 1--criterion reported but inadequate, 2--criterion reported and adequate. The studies were placed according to their scores in category A (score 20-22), category B (17-19) and category C (16 or less). Higher scores indicate better quality of studies. Where possible, statistical analysis of comparative data was performed. Most reports of HALDN are expert series, some comparative and a few prospective. There was good correlation between the assessors (r = 0.91), and of the seven published series on HALDN, two fell into category B and five into category C. At present, there is only one published randomised-controlled trial of HALDN vs. open donor nephrectomy; this is the only such trial in laparoscopic urology. HALDN allows kidneys to be harvested with short operating and warm ischaemia times and fewer ureteric complications. HALDN is a relatively new and effective technique, designed to make kidney donation more attractive and minimally invasive without affecting recipient outcomes. More prospective data of this technique is needed, and wide variation in reported outcome parameters need to be standardised to allow meaningful comparison.

Humans↗

Flexible ureterorenoscopy: prospective analysis of the Guy's experience.

OBJECTIVE: To report our outcomes with small diameter, actively deflectable flexible ureterorenoscopy from a prospective database. PATIENTS AND METHODS: 114 flexible ureterorenoscopies were performed in 105 patients (mean age, 49.5 years; range, 19-85 years; 71 males, 34 females) over a 9-month period. Of these, 101 were for refractory stones following failed ESWL and 13 for diagnostic reasons. An Olympus URF P3 flexible ureteroscope with pressure irrigation was used. Electrohydraulic lithotripsy was used to fragment stones and the fragments were retrieved with Graspit, triradiate graspers or tipless baskets. RESULTS: Stents had previously been placed in 53% and dilatation of the ureteric orifice was necessary in 15%. In the stone group, the median operating time was 55 min (range, 15-210 min) and the median screening time 2.2 min (range, 0.3-9.1 min). Success was defined as complete stone clearance or good fragmentation to 2 mm or less. Overall success in this group was 72.3%. There was no statistically significant difference between lower and other calyces (P=0.83 Chi-square test). Successful outcome was achieved in 72% for stone size 10 mm or less, 80% for 11-20 mm and 50% for greater than 20 mm. Two or more procedures were needed in 8 patients. In the diagnostic group, the median operating time was 45 min (range, 20-60 min) and the median screening time 2 min (range, 0.3-8.3 min). The majority were for upper tract filling defects. Access and successful diagnosis was achieved in all cases. The major complication rate was 2.6%. The ureteroscope needed repair once during this series. CONCLUSIONS: Flexible ureterorenoscopy is an effective diagnostic and therapeutic tool in a select group of patients. It should be considered for ESWL-resistant upper tract stones but the results are poor in stones larger than 20 mm and percutaneous nephrolithotomy may be a better option in these patients.

Adult↗

Long-term outcomes of brachiobasilic transposition fistula for haemodialysis.

OBJECTIVES: The transposed basilic vein to brachial artery arteriovenous fistula provides secondary vascular access for haemodialysis. The long-term results of such fistula are assessed in this retrospective series. MATERIAL AND METHODS: Over a 5-year period 75 brachiobasilic transposition fistulae were performed in 74 patients. There was a median follow up of 14 months. RESULTS: Primary patency was achieved in 69 (92%) of the fistulae, and secondary patency in 74 (99%) of the fistulae. Successful interventions included angioplasties in four, and saphenous vein interposition in one, whilst three patients had failed thrombectomies. Dialysis was performed using 69 (92%) of the fistulae while 6 (8%) were never used. Of the 75 fistulae 47 (63%) were patent at follow up. Cumulative secondary patency was 66% at 1 year, 52% at 2 years, and 43% at 3 years. Complications developed in 41 (55%), and included thrombosis, infection, stenosis, arm oedema, bleeding, steal syndrome and microaneurysm formation. CONCLUSIONS: Brachiobasilic transposition fistulae have good long-term patency rates. The complication rate, although high, is lower than that reported for PTFE grafts. Brachiobasilic fistulae should be used in preference to PTFE grafts for secondary access.

Adolescent↗

Short-term temporal variation in PM2.5 mass and chemical composition during the Atlanta Supersite Experiment, 1999.

Measurements in urban Atlanta of transient aerosol events in which PM2.5 mass concentrations rapidly rise and fall over a period of 3-6 hr are reported. The data are based on new measurement techniques demonstrated at the U.S. Environmental Protection Agency (EPA) Atlanta Supersite Experiment in August 1999. These independent instruments for aerosol chemical speciation of NO3-, SO4(2-), NH4+, and organic and elemental carbon (OC and EC), reconstructed the observed hourly dry PM2.5 mass to within 20% or better. Data from the experiment indicated that transient PM2.5 events were ubiquitous in Atlanta and were typically characterized by a sudden increase of EC (soot) and OC in the early morning or SO4(2-) in the late afternoon. The frequent temporal decoupling of these events provides insights into their origins, suggesting mobile sources in metro Atlanta as the main contributor to early morning PM2.5 and more regionally located point SO2 sources for afternoon PM2.5 events. The transient events may also have health implications. New data suggest that short-term PM2.5 exposures may lead to adverse health effects. Standard integrated filter-based techniques used in PM2.5 compliance monitoring networks and in most past PM2.5 epidemiologic studies collect samples over 24-hr periods and thus are unable to capture these transient events. Moreover, health-effects studies that focus on daily PM2.5 mass alone cannot evaluate the health implications of the unique and variable chemical properties of these episodes.

Aerosols↗

Testis-sparing surgery for benign and malignant testicular tumours.

We report the technique of testis-sparing surgery in three young men with testicular tumours, two of which were found to be benign (Leydig cell tumour and benign teratoma) and one malignant (seminoma) on frozen section and final pathological evaluation. The principles of clamping the spermatic cord with a soft bowel clamp, testicular cooling with ice slush, tumour enucleation with clear margins, meticulous haemostasis and frozen section analysis were followed. Testicular preservation was successful in the patients with benign disease. The patient with seminoma was found to have a separate nodule of invasive, poorly differentiated seminoma in the residual testis, which had not been detected on preoperative ultrasound scanning. As a result he was converted to radical orchidectomy.

Adult↗

Spheromak as a relaxed state with minimum dissipation.

The principle of minimum dissipation of energy is utilized to obtain the spheromak configuration as a relaxed state. The Euler-Lagrange equation for the minimum dissipative relaxed state is solved in terms of Chandrasekhar-Kendall eigenfunctions analytically generalized in the complex domain. This state is non-force-free and further shows the nonconstancy of the ratio of parallel current to the magnetic field.

Journal Article↗

Radical prostatectomy in Britain and Ireland at the millennium.

OBJECTIVE: To report a national questionnaire survey of all consultant urologists, providing a 'snapshot' of attitudes, current practice and referral patterns for radical prostatectomy (RP) in Britain and Ireland at the millennium. METHODS: During 1999/2000 a simple questionnaire about RP was sent to the 487 urologists registered as full BAUS members. From 418 (86%) returns nine were excluded, to leave a study group of 409 urologists. RESULTS: In all, 157 (38%) consultants were undertaking RP, whilst 252 (62%) were not; 29 (18.5%) performed > 20 operations/year, 44 (28%) undertook 11-20, but 84 (53.5%) carried out < or= 10. During the survey period, 741 (51%) RPs were conducted in teaching hospitals and 724 (49%) in district general hospitals. Of the 252 not undertaking RP, 23 (9%) stated they wished to learn the technique. CONCLUSIONS: This questionnaire suggests that the number of urologists undertaking RP in the UK and Ireland has stabilized but confirms that over half perform < or = 10/year; outcome data are now required. Any change towards concentrating cases will have significant consequences for patient distribution and resources.

Attitude of Health Personnel↗