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Biomedical subjects

A R Mundy

Publications and source records attributed to A R Mundy.

At least 37 records · Page 2Linked to original sources
PubMed2001

Effect of antibiotics on enterocystoplasty urinary nitrosamine levels.

OBJECTIVES: To evaluate the microbiologic characteristics of enterocystoplasty urine and assess the influence of bacteria type and effect of prophylactic and therapeutic antibiotic administration on the urinary nitrosamine levels of patients with enterocystoplasty. Nitrosamines have been implicated in the development of cancer in patients with an enterocystoplasty. Urinary tract infection (UTI) is associated with elevated nitrosamine levels. METHODS: Urine samples were collected to determine the urinary nitrosamine levels and for microscopy, culture, and sensitivity from 42 patients with an enterocystoplasty and 6 normal controls. A subgroup of 5 enterocystoplasty patients with proven UTI was also evaluated by measuring the urinary nitrosamine levels before and after a therapeutic course of antibiotics. RESULTS: Of the 42 cystoplasty patients, 22 had a proven UTI; none of the controls had one. Sixteen of the cystoplasty patients were taking prophylactic antibiotics and had mean N-nitrosamine levels equivalent to the control levels. The mean nitrosamine levels were highest in patients with a UTI (1.9 micromol/L). Escherichia coli was the most common infecting organism (11 patients) and resulted in the highest mean nitrosamine levels (2.1 micromol/L). The nitrosamine levels fell with UTI treatment to within the control range. CONCLUSIONS: UTI occurs in 51% of enterocystoplasty patients and is associated with elevated mean urinary nitrosamine levels. E. coli is the infecting organism in 50% of cases. Antibiotic prophylaxis reduces the nitrosamine levels to those of the controls. UTI treatment results in a rapid reduction of elevated nitrosamine levels to control levels.

Adolescent↗
PubMed2001

Factors causing variation in urinary N-nitrosamine levels in enterocystoplasties.

OBJECTIVE: To establish the presence or absence of any diurnal or long-term variation in N-nitrosamine levels (which might be important in the development of cancer in enterocystoplasties) in enterocystoplasty urine, and to assess other factors that might alter enterocystoplasty N-nitrosamine levels. Patients, subjects and methods Thirty-six patients with enterocystoplasties and six normal controls were assessed. Urine samples were collected every 4 h over a 24-h period and N-nitrosamine levels determined using a modification of the Pignatelli METHOD: An additional urine sample was assessed by microscopy, culture and sensitivity. In a subgroup of 16 patients with an enterocystoplasty, the urinary N-nitrosamine levels were re-measured at 3-monthly intervals. RESULTS: No diurnal or long-term variation in urinary N-nitrosamine levels was identified. The mean N-nitrosamine levels were significantly higher in the cystoplasty group than in the controls (1.7 vs 1.0 micromol/L; P = 0.008). Mean N-nitrosamine levels were also significantly higher in enterocystoplasty patients with sterile pyuria than in those with no pyuria (P = 0.01). Those taking prophylactic antibiotics had significantly lower mean N-nitrosamine levels than those not doing so (P = 0.05). Individuals with infected urine and those needing to intermittently catheterize had higher N-nitrosamine levels than their counterparts, but this difference was not significant. Conclusion There were no diurnal or long-term variations in urinary N-nitrosamine levels. Levels were consistently higher in patients with inflamed or infected cystoplasties, those using intermittent self-catheterization and those not taking antibiotic prophylaxis.

Adolescent↗
PubMed2001

The Barbagli procedure gives the best results for patch urethroplasty of the bulbar urethra.

OBJECTIVE: To compare the surgical outcome using buccal mucosal free grafts in the Barbagli procedure (dorsal stricturotomy and patch technique) with the traditional ventral approach, for long bulbar urethral strictures. PATIENTS AND METHODS: Over a period of 6 years, a total of 71 patients with bulbar urethral strictures underwent buccal mucosal graft urethroplasty. Twenty-nine patients had a traditional ventral urethroplasty and 42 were managed by the Barbagli procedure with the stricturotomy and patch on the dorsal aspect of the urethra. RESULTS: At 5 years of follow-up 5% of patients who underwent the Barbagli procedure developed recurrent strictures, compared to 14% in the traditional ventral stricturotomy group. All patients developed postmicturition dribble of urine to some degree, which was troublesome in 17% in the Barbagli group and 21% in the ventral stricturotomy group. Complications attributable to out-pouching of the graft were not seen in either group. CONCLUSIONS: The dorsal stricturotomy and patch (Barbagli) procedure had a higher success rate than the traditional ventral urethroplasty. Comparing these results with our experience of skin inlay urethroplasty, buccal mucosal grafts seem to have advantages however they are used.

Follow-Up Studies↗
PubMed2001

Substitution urethroplasty with buccal mucosal-free grafts.

PURPOSE: Buccal mucosal grafts and the Barbagli technique are recent developments in the treatment of urethral strictures. MATERIALS AND METHODS: We reviewed the results of and experience with urethroplasty using buccal mucosal graft in 128 patients. RESULTS: The re-stricture rate was 11% for patch grafts and 45% for tube grafts. There were no other complications. CONCLUSIONS: Buccal mucosal graft is at least as good as any other material for substitution urethroplasty with fewer complications. The 2-stage is more reliable than the stage 1 approach for circumferential reconstruction of the urethra.

Adolescent↗
PubMed2001

Cadaveric dissection for the rectal surgeon.

The benefits of total mesorectal excision are due to the complete excision of the mesorectum with preservation of the pelvic autonomic nerve plexuses, the hypogastric nerves and nervi erigentes. Several important structures are incompletely seen at operation, and cadaveric dissection of an intact lower trunk and a sagittally hemisected pelvis is a valuable exercise in demonstrating them. A method for dissection is described which illustrates the key anatomical points.

Autonomic Nervous System↗
PubMed2001

The nature of urethral injury in cases of pelvic fracture urethral trauma.

PURPOSE: We examine the urethral injury associated with pelvic fracture that is said to be due to a shearing force through the membranous urethra which inevitably destroys the urethral sphincter mechanism. MATERIALS AND METHODS: A total of 20 asymptomatic cases were prospectively studied, including symptomatically, radiologically, endoscopically and urodynamically, 1 to 4 years after an apparently successful anastomotic repair of a pelvic fracture urethral distraction defect. RESULTS: There was evidence of urethral sphincter function, including urodynamically in 11 (55%), endoscopically in 13 (65%) and functionally in 17 (85%) patients. CONCLUSIONS: These findings, coupled with surgical observation, suggest that the urethral injury associated with pelvic fracture is avulsion of the membranous urethra from the bulbar urethra rather than a shearing through the membranous urethra, and that some degree of urethral sphincter function is preserved in a significant percentage of patients.

Accidents, Traffic↗
PubMed2001

A new approach to recording the electromyographic activity of detrusor smooth muscle.

PURPOSE: Extracellular recordings from the whole intact mammalian bladder of the electrical events leading to contraction of the organ have been elusive for almost 50 years despite the widespread potential applications of such a technique. The principal problem is the need to isolate the small real signals reflecting membrane depolarization from the large electromechanical artifact generated as the organ contracts. In this preliminary study we determined whether electrical signals may be isolated and verified as biological using extracellular bipolar reversible suction electrodes. MATERIALS AND METHODS: Six whole excised guinea pig bladders were mounted in an especially constructed organ bath. Electrical activity resulting from nerve stimulation of the organ was recorded using a novel 10 bipolar Pt/PtCl suction electrode simultaneously with changes in intravesical pressure. Mechanical and pharmacological control experiments were performed to determine the true origin of these signals. RESULTS: A predominantly biphasic electrical signal of a mean amplitude plus or minus standard deviation of 647 plus or minus 301 microV. and a mean duration of 293 plus or minus 51 milliseconds was consistently recorded from the serosal surface of all guinea pig bladders. In all cases the electrical signal and mechanical response to stimulation were completely abolished by 1 microM. tetrodotoxin. The signal always preceded any change in intravesical pressure. It was sensitive to changes in the CaCl2 concentration of the superfusate, abolished by purinergic but not cholinergic neuromuscular blockade and independent of electromechanical artifact. CONCLUSIONS: In this preliminary report we describe a novel technique by which nerve mediated detrusor electrical activity leading to contraction of the whole intact guinea pig bladder may be isolated from artifact and verified as real. We hope that development of this technique may enable its application to the in situ human bladder. However, to our knowledge whether electromyographic activity may be recorded from human detrusor remains to be determined.

Animals↗
PubMed2000

'Nerve-sparing' cystectomy in women.

Although the indications for cystectomy other than for cancer are few, it is occasionally necessary for severe interstitial cystitis or hemorrhage due to radiation cystitis. The use of substitution cystoplasty after cystectomy has increased in men in the last decade, and this has resulted in the development of 'nerve-sparing' approach to cystectomy to improve continence and potency. The use of substitution cystoplasty in women after cystectomy has lagged behind that in men because it was considered necessary to remove the entire urethra, making orthotopic substitution impossible. Recently the need to remove the entire urethra has been questioned, with the finding that if the bladder neck is free of tumour, recurrence of disease in the urethra has not so far been found to occur. In addition, it appears possible to substitute on to the urethra without incontinence. This has led to the development of a 'nerve-sparing' technique of cystectomy, and renewed interest in the anatomy of the urethra. This paper reviews the current literature on 'nerve-sparing' cystectomy and describes our technique.

Cystectomy↗
PubMed2000

Towards a minimum dataset in urology.

OBJECTIVE: To establish and prospectively collect data for a minimum dataset in urology by agreeing a dataset amongst a group of urologists, designing structured forms around the data items and implementing them in clinical practice. METHODS: Consultant urologists decided the initial dataset. Structured forms, which incorporated the dataset items, were designed. These forms were piloted before implementation in two urology departments. They were used to document clinical information instead of writing this in the traditional medical record. After use forms were 'scanned' before being filed in the medical record, thus storing the data in an electronic format. RESULTS: Nine forms were designed; inpatient and outpatient activity was captured separately. There were six outpatient forms; a generic new patient form and five specific follow-up forms (lower urinary tract symptoms, oncology, erectile dysfunction, female urology and stones). Three generic inpatient forms were designed. The forms were used by nine registrars, five senior house officers and six clinical nurse practitioners, who required minimal training. CONCLUSION: It is possible to agree a minimum dataset amongst a relatively small group of urologists. The information can be acquired prospectively using structured forms instead of the traditional medical record. This locally agreed dataset could form the basis for a national consensus on a minimum dataset in urology.

Data Collection↗
PubMed2000

The long-term outcome of artificial urinary sphincters.

PURPOSE: We reviewed the outcome of artificial urinary sphincters inserted more than 10 years ago. MATERIALS AND METHODS: We analyzed the records of 100 patients and mailed a questionnaire to those without recent followup. RESULTS: Overall 84 patients were continent, including 36 with the original artificial urinary sphincter in place who were dry at a median followup of 11 years and 27 in whom the device was successfully replaced due to mechanical failure who were previously continent for a median of 7 years. In 21 patients it was removed due to infection or erosion and reimplantation was successful 3 to 6 months later or they remained dry without another artificial urinary sphincter. Of the male patients with a bulbar and bladder neck sphincter 92% and 84%, respectively, were continent at 10 years as well as 73% of the females. Device survival was 66% at 10 years. Overall 37% of the prostheses were removed due to infection or erosion in the 10-year period with the highest risk in females (56%) and lowest in males with a bulbar sphincter (23%). CONCLUSIONS: The artificial urinary sphincter is effective long-term treatment for incontinence in male patients. In female patients the risk of erosion is high, although overall long-term continence is satisfactory.

Adolescent↗
PubMed1999

Pelvic fracture injuries of the posterior urethra.

Posterior urethral injuries are not common and take a low priority in the management of patients with pelvic fracture injuries as these individuals almost always have multiple injuries of more serious consequence. Most patients are best treated by a suprapubic catheter for 3 months and then an end-to-end anastomotic urethroplasty in those who have developed urethral occlusions. There are roles for delayed primary repair and for endourological management in selected patients, but their exact roles have yet to be defined.

Erectile Dysfunction↗
PubMed1999

Pelvic fracture injuries of the female urethra.

OBJECTIVE: To review pelvic fracture urethral injuries in women, generally regarded as rare and thus discussed infrequently. PATIENTS AND METHODS: Twelve patients (age range 7-51 years) with such injuries were reviewed; most had associated injuries, generally more severe than seen in males with urethral injuries. RESULTS: Patients with milder injuries, perhaps damaging just the innervation of the urethra, presented with incontinence; more severe injuries seemed to cause a longitudinal tear in the urethra but again patients presented mainly with incontinence problems. The most severe injuries were associated with complete rupture of the urethra and a distraction defect suggesting an avulsion injury. These problems were difficult to treat both reconstructively and in providing continence. CONCLUSIONS: Pelvic fracture urethral injuries occur in females, but less often than in males. The female urethra seems relatively resistant to injury; differing degrees of severity of pelvic trauma cause different types of urethral injury but in general, a more severe injury is needed to damage it than is necessary in males.

Adolescent↗