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Biomedical subjects

M E Mayo

Publications and source records attributed to M E Mayo.

At least 37 records · Page 2Linked to original sources
PubMed1988

Ileocecal bladder augmentation in myelodysplasia.

We discuss 14 children and adolescents with myelodysplasia who underwent bladder augmentation with the ileocecal segment. The bowel was not detubularized nor was the ileocecal valve intussuscepted. Urodynamic evaluation was performed before and after the procedure in 13 patients with a followup of 1 to 8 years. Postoperative capacity and compliance were normal but cecal contractions occurred in 8 patients despite adequate doses of anticholinergics. Reflux was demonstrated at capacity with a cecal contraction in 4 patients but upper tract dilatation and infection were not clinical problems. Three patients required reoperation for complications owing to ureteroileal stenosis and/or urinary tract calculi. Although the clinical results were satisfactory, detubularized segments of bowel with intussuscepted afferent loop valves to prevent reflux may resolve these problems in the future.

Adolescent↗
PubMed1987

Bacteriuria with fever after spinal cord injury.

Urinary tract infection continues to be a common problem among spinal cord injured (SCI) individuals despite the strides that have been made during the last decade in the care of the neurogenic bladder. A critical analysis of the system of drainage compared with the occurrence of bacteriuria with fever (BWF) is reported in a group of 705 SCI patients. At the first year (year 1) follow-up, patients being catheterized by someone else (ICO) were much more likely to have experienced at least one episode of BWF than those on self-intermittent catheterization (SIC) (p less than 0.025) or those using an indwelling catheter (IND) (p less than 0.005). In patients who underwent external sphincterotomy, the incidence of BWF was significantly decreased in year 1 (p less than 0.025) compared to those on ICO.

Bacteriuria↗
PubMed1986

Comparative effects of four prostaglandin synthesis inhibitors on the obstructed kidney in the dog.

Comparative effects of four prostaglandin synthesis inhibitors (PGSI) on the acutely obstructed kidney were studied using an intact canine model. Trigonal vesicostomies were constructed and totally implanted nephrostomy tubes were placed to monitor renal pelvic pressures. After recovery, experiments were run at weekly intervals with one drug administered each week in a random fashion. Complete ureteral obstruction was obtained using a Fogarty balloon catheter passed retrogradely into the distal ureter and inflated. When renal pelvic pressure reached 80 cm./H2O the designated PGSI was given and a repeat dose was given 30 minutes later. Mean blood pressure was also monitored during several experiments. With the first dose significant decreases in renal pelvic pressure were obtained with all drugs tested. Only ibuprofen showed a significant further decrease with the second dose. Ibuprofen showed the greatest decrease in pressure with the first dose, which was significantly greater than the other drugs tested. There was no association between mean blood pressure changes and the nadir of renal pelvic pressure.

Animals↗
PubMed1985

Effect of percutaneous nephrostolithotomy on renal function.

In 15 patients with 17 stone-containing renal units renal function studies were performed before and 2 to 3 months after percutaneous nephrostolithotomy. The creatinine clearance of the operated renal units was calculated from the total creatinine clearance and differential renal function was obtained with radionuclides. Changes in the cortical images of the operated kidney also could be determined from the radionuclide scans. There was no significant change in the creatinine clearances when all of the operated kidneys were considered. However, there was significant improvement in the function of 12 units containing infectious stones in which preoperative function was reduced. Percutaneous nephrostolithotomy preserves or improves renal function and can be used for all types of renal stones.

Catheterization↗
PubMed1985

Infection stones in patients with myelomeningocele and ileal conduit urinary tract diversion.

Infection renal calculi are serious complications of urinary tract diversion in patients with myelomeningocele. During a 12-month period, 10 renal units containing calculi were managed surgically. The kidneys were in patients with multiple previous operations and medical problems. Nine of the ten stones had a staghorn configuration, filling the renal pelvis with calyceal extensions. Nephrectomy was necessary for a nonfunctional kidney and a conventional nephrolithotomy was done in one case. Endourologic techniques were used for treatment of eight renal units. Endourologic methods depended on placement of a percutaneous nephrostomy tube. The nephrostomy tract was dilated, then renal calculi were disintegrated under direct vision using ultrasound, and the stone fragments were removed. Six of eight kidneys (75%) were rendered stone-free using these methods. The other two kidneys had residual stone fragments located in isolated calyces with little potential for obstruction. Skin breakdown occurred in two patients, and two patients required transfusions. These results compared favorably with the results of conventional open surgery. Major advantages of percutaneous nephrolithotomy were evident during the postoperative period. Since there was minimal incision discomfort, patients were easily mobilized and there were no pulmonary problems. Patients were able to resume oral intake on the day of surgery and usually resumed full activities within one week of discharge. Percutaneous methods are a valuable aspect of a total therapeutic program for infection renal calculi in patients with myelomeningocele.

Adolescent↗
PubMed1985

Manual stimulation of reflex voiding after spinal cord injury.

Thirty-four urodynamic studies were performed in 20 patients with spinal cord injury (SCI) to determine the most effective triggering mechanism for reflex voiding. The studies were performed at a time when the patient was normally scheduled for catheterization, which avoided stimulation of the detrusor and sphincter by bladder filling via a catheter. The three methods chosen were used in a random sequence. Suprapubic tapping and jabbing were equally effective in producing a rise in detrusor pressure, and the sphincter responses were almost identical. Cutaneous stimulation of the thigh rarely produced any change in detrusor and sphincter activity. When detrusor contractions were produced, a dyssynergic sphincter response prevented voiding in 46% of the studies; however, voiding always occurred when the sphincters were either coordinated or showed no change. Both tapping and jabbing were more effective as the time from injury increased, which reflects the natural recovery from spinal shock.

Humans↗
PubMed1984

Current treatment of infection stones in high risk patients.

During a 12-month interval we removed struvite calculi from 20 kidneys in high risk patients, including 10 kidneys with branched stones. Endourological methods were used for primary treatment of 16 renal units and 12 (75 per cent) are free of stones. Endoscopic removal of residual stone fragments also was successful in 2 of 3 patients following a conventional open operation. The remaining stone fragments were located in isolated calices. Endourology presently is an integral component of a total therapeutic program for management of complicated patients with struvite calculi.

Persons with Disabilities↗
PubMed1983

Experimental study of ureteral calculus disease: effects of calculus size, obstruction and hydration.

A chronic canine model was developed to study the immediate mechanical effects of ureteral calculi. Totally implanted nephrostomy tubes were used to measure renal pelvic pressure and optical sensors recorded ureteral activity. Surrogate calculi were inserted in a retrograde fashion via a trigonal vesicostomy. Complete obstruction was more common with larger calculi and these all passed spontaneously, by which time ureteral activity had ceased. Reduction in urine output delayed the rise in renal pressure and thus prolonged the time the calculus was retained in the ureter. If large calculi, which normally obstruct, had holes drilled in them to allow free urine flow they remained in the ureter for at least 2 hours and had to be extracted. Therefore, in the first few hours increased proximal hydrostatic pressure was the most important factor responsible for the spontaneous passage of obstructing calculi.

Animals↗
PubMed1983

Clinical experience with upper tract urodynamics.

Of 25 upper tract urodynamic studies performed in 22 patients 9 positive results were obtained. The diagnosis of intrinsic ureterovesical junction obstruction was suspected in 11 children but only confirmed in 2. However, in 6 other children changes in bladder volume markedly affected upper tract function. While diuretic renography may confirm obstruction in many doubtful cases, when function is poor and the system is dilated massively a urodynamic study often will be the only definitive diagnostic procedure.

Adolescent↗
PubMed1981

The effect of autonomic drugs on ureteric peristalsis: a canine in vivo study.

An in vivo canine model was developed in which the renal pelvis was perfused by a cannula nephrostomy and ureteric activity assessed by monitoring bolus volume and interperistaltic interval. The effect of autonomic drugs showed that the ureter contained alpha-adrenergic receptors which on stimulation caused an increase in ureteric contraction rate and a decrease in bolus volume. With beta-adrenergic receptor stimulation, there was complete inhibition of ureteric peristalsis for a variable period and evidence is presented that the beta-adrenergic receptors may be beta 1 rather than beta 2. Cholinergic stimulation of ureteric rate was observed, but seemed to be mediated indirectly via alpha-adrenergic receptors. No significant change was seen in ureteric activity with adrenergic blocking agents alone, suggesting that the physiological importance of these receptors in normal activity is questionable.

Animals↗
PubMed1981

Management of ileal conduit stomal obstruction: a urodynamic study.

Urodynamic perfusion studies have shown that edema or incrustation and ulceration may produce stomal obstruction in patients with ileal conduits. High emptying pressures may be present before there is any increase in the residual or conduit capacity, or before upper tract deterioration has occurred. Nine patients with early stomal obstruction were treated medically with acidification of the urine in the collecting bag and were compared to 6 patients who had stomal obstruction owing to irreversible changes and who were treated by surgical revision. In both groups emptying pressure returned to normal after treatment.

Adolescent↗
PubMed1981

The effect of glucagon and diazoxide on the normal and obstructed upper urinary tract.

The effect of diazoxide and glucagon were studied on the freely draining upper urinary tract and after varying periods of obstruction in dogs. Without obstruction, diazoxide produced longer inactive periods than glucagon and recovery was associated with less retrograde activity. Following obstruction for 5--10 min, 6 and 24 h, diazoxide decreased renal pressure and the effect was greatest when the upper tract was obstructed for the shortest period. Glucagon also produced an overall reduction in pressure after 5--10 min and 6-hour periods of obstruction, but there was an initial rise in pressure after 5--10 min of obstruction. At 24 h there was an increase, but no overall decrease in pressure after glucagon. Diazoxide produced a greater fall in pressure after 5--10 min and 24 h of obstruction, and a faster fall in pressure after 5--10 min and 6 h of obstruction as compared to glucagon. Diazoxide may be a more effective therapeutic agent in the management of ureteral calculus disease than glucagon.

Animals↗
PubMed1980

The clinical use of epididymal aspiration cultures in the management of selected patients with acute epididymitis.

Culture and sensitivity testing of specimens obtained by percutaneous and intraoperative needle aspiration of the epididymis have been of clinical importance in choosing proper antimicrobial therapy in selected patients with acute non-venereal epididymitis. We have found aspiration cultures to be valuable in patients 1) with indwelling urethral catheters, 2) who fail to respond to initial antimicrobial therapy, 3) who have epididymitis found on surgical exploration for torsion of the teticle and 4) with recurrent epididymitis in whom the etiologic agent is uncertain.

Acute Disease↗
PubMed1980

The effect of bladder function on the dynamics of the ureterovesical junction.

Upper tract perfusion studies in suspected ureterovesical junction obstruction should always be performed with measurement of intravesical pressure and with variation in bladder volume. Obstruction observed with increasing bladder volumes may be related to a non-compliant bladder wall, mechanical obstruction at or near the junction itself or a combination of both factors.

Adolescent↗
PubMed1980

Increased residual urine in patients with bladder neuropathy secondary to suprasacral spinal cord lesions.

Multichannel urodynamic studies were done on 30 patients with incomplete bladder emptying secondary to suprasacral spinal cord lesions. In 11 patients fluoroscopy was done simultaneously. A single most important factor accounting for the increased residual urine was present in 21 cases: inadequate detrusor contraction in 10, sphincter dyssynergia in 6 and bladder neck obstruction in 5. A combination of 2 of these factors was present in 3 patients. Although the initial residual urine volume was high in 6 patients voiding during the urodynamic study was efficient and no residual urine was demonstrated at that time. Urethral pressure profiles were variable, depending on whether a spastic external sphincter contraction was present during the procedure. It is concluded that bladder pressure and sphincter electromyographic measurement during voiding, combined with fluoroscopy, are ideal methods to identify the factors responsible for incomplete emptying in problem cases. The urethral pressure profile is of limited value in the initial assessment of these patients.

Electromyography↗
PubMed1979

Urodynamic assessment of incontinence after prostatectomy.

There were 15 men with incontinence after prostatectomy who were assessed with a urethral pressure profile and a multichannel filling and voiding study with sphincter electromyography. Of these 15 patients 7 had sphincter weakness alone, 7 had sphincter weakness and detrusor hyperreflexia, and 1 had detrusor hyperreflexia alone. Full urodynamic assessment is essential before treatment can be recommended for incontinence after prostatectomy.

Aged↗