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Biomedical subjects

D M Barrett

Publications and source records attributed to D M Barrett.

At least 73 records · Page 4Linked to original sources
PubMed1991

Significance of aberrant immunophenotypes in childhood acute lymphoid leukemia.

Leukemic cells from 51 pediatric patients (younger than 18 years) diagnosed with acute lymphoid leukemia by standard morphologic and cytochemical methods were subjected to flow cytometric studies using a panel of monoclonal antibodies against T-cell (CD1, 2, 3, 4, 5, 7, 8), B-cell (CD10, 19, 20, 21), myeloid (CD13, 14, 15, 33), and HLA-DR antigens. Cases of "conventional" acute lymphoid leukemia (leukemic cells with a normal configuration of B-cell or T-cell differentiation antigens) were observed in 26 of 51 (51%) cases, whereas cases of "aberrant" acute lymphoid leukemia (cells with abnormal patterns of B-cell or T-cell antigens or with concomitant myeloid antigens) were noticed in 25 (49%) cases. Myeloid antigen-positive acute lymphoid leukemia was observed in the leukemic cells of eight (16%) individuals. No significant differences were observed between conventional and aberrant ALL in the distribution of sex, age, leukocyte count, hemoglobin concentration, platelet count, blast count, French-American-British (FAB) type, lymphadenopathy, organomegaly, rate or duration of remission, or survival. When only myeloid antigen-positive cases were compared with myeloid antigen negative-cases, no significant correlations were observed except for duration of first remission (myeloid antigen positive, 26+ +/- 22 months; myeloid antigen negative, 40+ +/- 18 months; P less than 0.001), and duration of survival (myeloid antigen positive, 27+ +/- 24 months; myeloid antigen negative, 62+ +/- 17 months; P = 0.001). These data suggest that pediatric patients with ALL blasts possessing myeloid antigens may represent a high-risk group for length of remission and survival.

Adolescent↗
PubMed1991

Particle shedding and migration from silicone genitourinary prosthetic devices.

Of 26 patients undergoing revision of genitourinary prostheses the surrounding reactive fibrous capsule was biopsied in 25 and the draining lymph nodes also were biopsied in 4. The prostheses included 16 inflatable and 14 flexible penile devices, and 10 artificial urinary sphincters. Tissue was examined by light and transmission electron microscopy. X-ray microanalysis was done on intracellular and extracellular foreign material from each specimen. Silicone was found in 18 of the 25 periprosthetic specimens and in all 4 lymph nodes. Foreign body granulomas were identified in 14 of these 29 specimens. Examination of new and explanted versions of each prosthesis by scanning electron microscopy revealed free particles of silicone or silicates on the surface of most devices. Pitting and microfissuring were seen on a few of the new devices and on nearly all of the used ones. Thus, genitourinary prostheses shed silicone particles that can be found in the fibrous capsule and draining lymph nodes.

Adolescent↗
PubMed1991

Artificial bladder and the use of the artificial sphincter.

Gradually, the lifestyle that can be offered to a patient who requires a cystectomy or has a small incontinent bladder is being improved. It is possible to combine sphincter placement with cystoplasty and neobladder formation if the surgery is carried out with care. Further development of the sphincters is required before their use around bowel segments will provide consistently safe results. Concurrently, development of the totally artificial bladder is progressing toward an ideal of a system that is biocompatible and preserves renal function.

Equipment Design↗
PubMed1991

Anastomotic obstruction after stapled enteroanastomosis.

We have recently treated two cases of anastomotic obstruction after side-to-side stapled enteroanastomosis. Complete obstruction of a stapled small-bowel anastomosis has not been reported to our knowledge. The mechanism of the obstruction appears to be the healing together of the cut edges of viable bowel beyond the inverted stapled lines. An alternative method of constructing the functional end-to-end enteroanastomosis that is offered is intended to prevent the occurrence of postoperative anastomotic obstruction.

Adolescent↗
PubMed1990

Artificial urinary sphincter cuff erosion. Experience with reimplantation in 38 patients.

Artificial urinary sphincter cuff erosion has become rare but remains a dreaded consequence of sphincter implantation. Our experience indicates that with rational and systematic management of this problem, sphincter reimplantation can restore continence in many of these patients. During a ten-year period, 412 artificial sphincters were implanted at the Mayo Clinic. Bladder neck or urethral erosion occurred in 64 patients (15.5%). Ultimately, 38 patients had reimplantation, and the outcome was successful in 32 (84%). After the advent of delayed activation, the incidence of cuff erosion decreased greatly--from a peak of 18 percent (12 of 66 cases) in 1977 to 1.3 percent (1 of 79 cases) in 1985.

Female↗
PubMed1990

Primary lymphoma of prostate: transrectal ultrasonic appearance.

In the case presented, primary lymphoma of the prostate was diagnosed by ultrasonically guided transrectal biopsy. Primary lymphoma of the prostate should be included in the differential diagnosis of a hypoechoic lesion found on ultrasonic evaluation of the prostate in a young adult.

Adult↗
PubMed1990

Application of the AS-800 artificial sphincter for intractable urinary incontinence in females.

Intractable incontinence is a challenging problem, especially in females who have been operated upon frequently for the correction of this problem. Twenty-four such females (age 11 to 78 years) received an artificial sphincter (AS-800). The mean follow-up time was 41 months (range of eight to 66 months). Detubularized augmentation cystoplasty was performed upon six patients, simultaneously with sphincter implantation in three patients and in two stages in the others. Seventeen patients reported "good" continence, and three reported continence as "fair, improved." The four failures occurred in patients in whom the sphincter had been extracted because of erosion and infection of the bladder neck cuff. A total of 12 revisions were necessary, nine during the first two years after sphincter implantation (0.5 revisions per patient). Two patients who had successful pregnancies underwent deactivation of the sphincter in the third trimester. Strict attention to surgical principles, postoperative care and careful selection of patients have made the AS-800 artificial sphincter a reliable option in treating intractable sphincteric incontinence in females.

Adolescent↗
PubMed1989

Augmentation cystoplasty and the artificial genitourinary sphincter.

In 18 patients with urinary incontinence secondary to decreased bladder compliance and sphincteric incompetence, augmentation cystoplasty and the artificial genitourinary sphincter were combined successfully to produce complete urinary control. Insertion of the sphincter was simultaneous with augmentation cystoplasty in 11 patients. In 6 patients the artificial sphincter was placed before augmentation cystoplasty. One patient underwent placement of a sphincter subsequent to enterocystoplasty and failed Young-Dees reconstruction of the vesical neck. It is noteworthy that in all 6 patients who underwent sphincteric placement before bladder augmentation decreased bladder compliance and urinary incontinence developed with time, and upper tract deterioration developed in 2 patients. Fifteen patients empty the bladder by intermittent self-catheterization, and 3 teenagers void by relaxation of the pelvic musculature and abdominal straining. In selected patients with complex urinary incontinence augmentation cystoplasty and placement of an artificial genitourinary sphincter cuff can be combined successfully without increase in morbidity over that with either procedure performed separately.

Adult↗
PubMed1989

Combined implantation of artificial sphincter and penile prosthesis.

Concurrent sphincteric incontinence and organic impotence are not uncommon; they can be caused by many congenital and acquired conditions. In the past simultaneous implantation of the artificial sphincter and penile prosthesis was met with skepticism. Of 65 patients who had concurrent implantation of the artificial sphincter and various categories of penile prosthesis 60 were followed for a mean of 35.74 months (range 8 to 55 months). Continence was graded as good or satisfactory in 95 per cent of the patients and poor in 5 per cent. The penile implants were functional in 98 per cent of the patients. Of the 60 patients 33 required 59 corrections, for an average of 0.98 correction per patient. These results indicate that staged or concurrent implantation of dual prostheses is feasible technically, functionally and cosmetically, and without increased risk for surgical or mechanical problems.

Adult↗
PubMed1989

Mayo Clinic experience with use of the AMS800 artificial urinary sphincter for urinary incontinence following radical prostatectomy.

The model AMS800 artificial urinary sphincter was implanted in 117 patients with urinary incontinence resulting from radical prostatectomy. The indication for implantation was total incontinence in 107 patients and stress incontinence in 10. All patients had bulbous urethral cuff insertion and 20 had previous pelvic irradiation. Followup questionnaire indicated a 90% significantly improved continence rate and a 90% satisfaction rate among patients. There were 64 surgical revisions required in 37 patients: inadequate cuff compression in 21 (33%), tubing kinks in 10 (16%), urethral cuff erosion in 8 (13%), scrotal hematoma in 6 (9%), control assembly malfunction in 4 (6%) and cuff leaks in 4 (6%). Of the 20 patients with previous pelvic radiation 2 (10%) had at least 1 erosion, compared to 5 of 97 (5%) in the nonirradiated group. At followup 5 patients did not have at least 1 component of the AMS800 device indwelling (2 cuffs and 3 entire devices had been removed).

Consumer Behavior↗
PubMed1989

The genitourinary spheroidal membrane: an experimental study of a new percutaneously inserted prosthetic device for the control of urinary incontinence.

The genitourinary spheroidal membrane, composed of silicone rubber, has been developed along with a mechanical delivery instrument that allows transcutaneous insertion of the prosthetic sphere in the periurethral tissues to enhance outlet resistance in incontinent patients. An experimental study was undertaken in six female mongrel dogs to evaluate the safety and efficacy of this concept. The leak-point pressure increased from five to 38 cm. H2O (mean increase, 16.8 cm. H2O). This increase is statistically significant (p less than 0.024, two-sided t test). During the 90-day experiment, there was no migration of the spheres, minimal local inflammatory response, and no granuloma formation or inflammatory response in various organs studied. Although the leak-point pressure was increased in all of the dogs, none developed difficulty voiding. We conclude that the design concept is sound and safe, the delivery system is reliable, and it is possible to place the spheroidal membrane into an anatomic location that will increase outlet resistance.

Animals↗
PubMed1989

The artificial sphincter (AS-800). Experience in children and young adults.

From reviewing our experience in the application of the AS-800 sphincter for the management of incontinence in children, we conclude that implantation is indicated after conservative and less invasive therapy has been attempted. The bladder neck is the site of choice for cuff placement in children. Primary deactivation and moderate or low reservoir pressures (61 to 70 and 71 to 80 cm H2O) are indicated, especially in patients with previous bladder neck surgery or an inadvertent bladder neck injury. Excess residual urine should be evacuated by clean intermittent catheterization. The AS-800 is mechanically reliable (9 mechanical failures in 45 sphincters). When the sphincter is implanted in a select group of patients, upper tract function is maintained in a stable state. Detubularized augmentation cytoplasty must be used to supplement the sphincter in patients with low-compliance, low-capacity, and nonresponsive hyperreflexic bladders. In all patients, long and careful follow-up is necessary to identify late changes in bladder function and consequent upper tract damage. An overall satisfactory result (fair to good) was obtained in 88 per cent of patients during an average follow-up period of 35 months, and 0.6 modifying procedure per patient was done in the sphincters.

Adolescent↗
PubMed1988

Comparison of techniques for vesicourethral anastomosis: simple direct versus modified Vest traction sutures.

Radical retropubic prostatectomy has become a mainstay surgical procedure in the treatment of cancer of the prostate. There has been controversy, however, regarding the most appropriate method of vesicourethral reconstruction. We examined the records of 692 consecutive patients who underwent a radical retropubic prostatectomy from 1978 through 1984 at the Mayo Clinic. Of these, 416 patients underwent a modified Vest procedure, and in 276 patients a direct simple anastomosis was fashioned. In comparing these two methods, our review showed no substantial difference in complications, including the rate of urinary incontinence.

Adenocarcinoma↗
PubMed1988

Urinary incontinence in adults.

Abnormalities of the micturition cycle are responsible for a large number of visits to the urologist. Some of these abnormalities produce annoying symptoms; others may lead to hazardous and disabling changes in the urinary tract. Urinary incontinence in adults results from an abnormality of one or more of the factors involved in the two phases of the micturition cycle: filling-storage and emptying. Proper management requires judicious selection among the pharmacologic and surgical alternatives.

Adult↗
PubMed1987

An alternative technique for undiverting the sigmoid conduit.

A technique for undiverting a colonic conduit of limited capacity and with short ureters is described. The colonic segment of the conduit and an additional segment of small bowel are patched together to form a low pressure cystoplasty of large capacity. This technique incorporates 3 principles that are believed to be important in reconstructing any type of cystoplasty: large capacity, increase in diameter and disruption of the strong circular muscle layer of the bowel by detubularization.

Adolescent↗
PubMed1987

Urodynamic evaluation of patients after the Camey operation.

Ten patients were evaluated urodynamically 3 to 18 months after they underwent the Camey operation. Of these patients 2 had total diurnal and nocturnal continence, 1 was totally incontinent and 6 were incontinent to various degrees that necessitated the use of 1 to 3 pads or diapers per day. All but 2 of the Camey neobladders had cystoplasty contractions at a capacity of 50 to 200 ml. The 2 totally continent patients had no cystoplasty contractions. The bladder in the totally incontinent patient had good capacity, good compliance and low pressure contractions up to a volume of 400 ml. The condition in this patient may be attributed to sphincteric incontinence. Urinary flow is achieved by abdominal straining and is interrupted. Vesicoureteral reflux occurred in 3 of 20 renal units.

Aged↗