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Biomedical subjects

R Mathews

Publications and source records attributed to R Mathews.

At least 19 recordsLinked to original sources
PubMed2000

Penile reconstruction combined with bladder closure in the management of classic bladder exstrophy: illustration of technique.

OBJECTIVES: Interest has increased in combining procedures during reconstruction of bladder exstrophy in an effort to reduce the number of procedures required for reconstruction and to improve results. This study illustrates our technique of reconstruction and summarizes our current experience with the combination of epispadias repair and bladder closure during initial reconstruction or following prior failed bladder closure. METHODS: Twenty-four boys with classic bladder exstrophy underwent combined bladder closure and epispadias repair. The mean patient age was 20 months, and 18 boys had a prior failed closure. Osteotomies were performed in all patients. RESULTS: No instances of bladder prolapse or dehiscence were noted on follow-up. Urethrocutaneous fistula developed in 7 patients. Eventual bladder neck reconstruction has been performed in 11 boys (6 boys are dry day and night, 3 are dry during the day with occasional wet episodes at night, 2 have required follow-up bladder augmentation and continent diversion for persistent incontinence), and 1 boy had augmentation at the same time as bladder neck reconstruction. Twelve boys are awaiting adequate capacity for bladder neck reconstruction, and 1 is awaiting bladder augmentation and continent stoma construction. CONCLUSIONS: Epispadias closure can be safely combined with bladder closure in select patients with classic bladder exstrophy. Complication rates and cosmesis approximate that achieved with staging the two procedures. This achievement represents strict patient selection and attentive follow-up.

Abnormalities, Multiple↗
PubMed2000

Bladder neck reconstruction in classic bladder exstrophy: the role of osteotomy in the development of continence.

OBJECTIVE: To assess the role of osteotomy at the time of bladder neck reconstruction (BNR) for continence in classic bladder exstrophy, in which closure of the pelvic ring and reconstitution of the pelvic diaphragm may affect eventual continence. PATIENTS AND METHODS: The results of using osteotomy at the time of BNR in 29 children were reviewed. The mean bladder capacity before BNR was 76 mL. The indications for osteotomy were a wide pubic diastasis and a soft intersymphyseal bar. After osteotomy, all children were maintained in external fixation and lower-extremity traction for 6-8 weeks. RESULTS: Complications of osteotomy were limited to a partial femoral nerve palsy (one patient) and delayed union of fragments (one patient). Complications of BNR included urethral stricture (five patients) and bladder calculi (six patients). Continence results were modest, with 11 of 29 children (38%) dry during the day (dry interval >3 h) and eight of 29 (28%) dry at night. Eight children had daytime dry intervals of approximately 3 h. The mean preoperative bladder capacity in children who were dry both day and night was 101 mL. CONCLUSIONS: The preoperative bladder capacity remains a key determinant for the attainment of continence after BNR in the reconstruction of classic bladder exstrophy. Osteotomy allows pelvic closure and thus improves cosmesis of the mons and stabilizes the BNR in patients with a soft intersymphyseal bar, but seems to have no effect on continence when performed at the time of bladder neck plasty.

Bladder Exstrophy↗
PubMed2000

Cost analysis of the treatment of vesicoureteral reflux: a computer model.

PURPOSE: Surgical intervention for vesicoureteral reflux is generally limited to children who have recurrent infection despite adequate antimicrobial prophylaxis or in whom compliance with followup cannot be ensured. In addition, surgical therapy is considered in children with persistent reflux after a reasonable period of surveillance. We used a model based on the management of a theoretical population of girls with various grades of reflux and followed the costs incurred during a 5-year management period. MATERIALS AND METHODS: The literature on vesicoureteral reflux was used to create a set of assumptions regarding epidemiology, likelihood of resolution, need for operative intervention, risk of infection and appropriate regimen for nonoperative surveillance. These parameters were evaluated in infants and children as noted in the literature. A 5-year management period was considered. Patients in whom reflux did not resolve with medical management at the end of 5 years were assumed to have undergone surgical correction. Costs were calculated based on the amounts billed, managed care reimbursement and Medicaid reimbursement in Maryland. The costs of up front surgical management were calculated and compared to those of 5 years of standard management. All costs were discounted at a rate of 10%. RESULTS: Calculated costs of standard management were lower for lower grades than those for higher grades of reflux. The costs of surgical management were lower than those of standard management for higher reflux grades using nondiscounted costs. However, when costs were discounted to present value, the costs of standard management were significantly lower than those of up-front surgery for all scenarios studied. CONCLUSIONS: The cost of vesicoureteral reflux is considerable when whole patient groups are considered. Using cost as the only parameter the standard management of reflux is less costly than up-front surgery. In the individual surgical intervention usually is predicated by patient and family factors which were not considered in this model. This computer based construct allows data from different institutions to be analyzed to project costs of the management of reflux.

Child↗
PubMed2000

Orchiopexy using 2 mm. laparoscopic instruments: 2 techniques for delivering the testis into the scrotum.

PURPOSE: We describe modified techniques of laparoscopic orchiopexy using 2 mm. instruments that enable straightforward delivery of the testis into the scrotum. MATERIALS AND METHODS: The preferred technique involves a radially dilating trocar advanced over the 2 mm. grasper placed antegrade through the new internal ring. The other method is similar but Amplatz dilators are used when a radially dilating trocar system is not available. RESULTS: We used these techniques with complete success to deliver 18 testes into the scrotum. CONCLUSIONS: The testis may be safely and effectively delivered to the scrotum using 2 mm. instruments and disposable fascial dilators or a radially dilating trocar system.

Child, Preschool↗
PubMed1999

Anomalies of the inferior vena cava and renal veins: embryologic and surgical considerations.

Anomalies of the inferior vena cava and renal veins occur infrequently but if unidentified can lead to significant morbidity during surgical exploration. An understanding of the embryologic development of the vena cava and its tributaries is necessary to understand the genesis of these sometimes complex anomalies and their accompanying anatomic variants. Newer radiologic modalities in the form of spiral computed tomography (CT) and three-dimensional reconstruction of spiral CT allow clear definition of the anatomy of these anomalies. Variations in the embryologic evolution of the vena cava dictate the different venous anomalies that may be encountered in the retroperitoneum. Additionally, the utility of newer radiologic modalities in the identification of these anomalies is discussed.

Humans↗
PubMed1999

Single system ureteral ectopia in boys associated with bladder outlet obstruction.

PURPOSE: Ureteral ectopia is frequently associated with dysplasia of the associated renal segment in girls with ureteral duplication. However, single system ureteral ectopia is an uncommon anomaly more frequently noted in boys. We report on 6 boys with single system ureteral ectopia into the prostatic urethra above the verumontanum, who presented with radiological and clinical findings of bladder outlet obstruction. MATERIALS AND METHODS: Antenatal ultrasound in 3 boys demonstrated renal abnormalities and postnatal studies suggested the diagnosis of posterior urethral valve obstruction. Older boys presented with symptoms suggestive of bladder outlet obstruction. RESULTS: An ectopic ureter inserting into the prostatic urethra was noted in all 6 boys. The distal ureter was dilated elevating the bladder neck causing outlet obstruction. Surgical management consisted of nephrectomy and transurethral endoscopic incision of the distal ureter or nephroureterectomy with reconstruction of the prostatic urethra. In 2 younger boys voiding dysfunction with inability to empty developed. CONCLUSIONS: Single system ectopic ureters in boys may present with symptomatic and radiological findings resembling posterior urethral valves. Surgical treatment should include nephroureterectomy with reconstruction of the hypoplastic prostate. Some patients may have later voiding dysfunction.

Adolescent↗
PubMed1999

Neural innervation of the newborn exstrophic bladder: an immunohistochemical study.

PURPOSE: Continence in bladder exstrophy is not always easy to attain. Some patients have a small noncontractile bladder while in others an adequate capacity bladder may not contract normally. Innervation of the detrusor determines its ability to contract. The exstrophic bladder during organogenesis does not store urine. Therefore, its requirements for contraction are limited and its innervation would potentially reflect this difference in function. The availability of specific immunostains allows better differentiation of the neural elements in tissue specimens. Our study focuses on myelinated nerves innervating the newborn exstrophic detrusor. MATERIALS AND METHODS: Biopsies were obtained from the anterior wall of 10 newborn exstrophic bladders at the time of initial closure and compared to 10 newborn controls. Patient age at bladder closure ranged from 1 to 90 days (mean 22). Specimens were formalin fixed and paraffin embedded. Then 4 micro. thick sections were stained with S100, an immunostain that stains neural crest elements including Schwann's elements (myelinated nerve fibers). The entire tissue section was examined. Microscopic fields were sequentially examined with a morphometric system comprising a microscope, video camera and personal computer with a video frame grabber. The output image was displayed on a second monitor and the nerves in each field and numbers of fields in each section were counted. To be considered, fields had to have greater than 75% tissue coverage. The average number of nerves per field was compared between the exstrophic bladders and normal controls. RESULTS: The average number of myelinated nerves per field in the newborn exstrophic bladders (0.13 per field) was significantly reduced compared to normal controls (1.25 per field) and statistically significant (p<0.001). This reduction in nerve fibers appeared to be due to lack of smaller fibers with preservation of larger fibers. There was no difference in innervation in cases closed at birth compared to those closed after month 1 of life. CONCLUSIONS: The newborn exstrophic bladder has fewer myelinated nerve fibers than normal controls primarily due to reduction in the smaller fibers which may represent a maturational delay in the development of the exstrophic bladder. Another possible explanation may be degeneration of the fibers due to lack of bladder contraction but no indication of nerve degeneration was evident in our study. Followup studies of patients at various stages of reconstruction will determine the evolution of neural innervation in the exstrophic bladder.

Bladder Exstrophy↗
PubMed1999

Hyperbaric oxygen therapy for radiation induced hemorrhagic cystitis.

PURPOSE: Radiation therapy has been used successfully to treat pelvic malignancy but morbidity from hemorrhagic cystitis remains a major long-term sequela in 1 to 2% of patients. Obliterative endarteritis secondary to ionizing radiation leads to tissue hypoxia and poor healing. Hyperbaric oxygen therapy has been demonstrated to improve angiogenesis and promote healing in radiation injured tissue, including the bladder. We describe the treatment and long-term followup of a cohort of patients treated with hyperbaric oxygen for hemorrhagic cystitis. MATERIALS AND METHODS: A total of 17 patients (mean age 62 years) with hemorrhagic cystitis received hyperbaric oxygen following failure of standard treatment modalities. Hyperbaric oxygen was administered on a once daily schedule (mean number of treatments 14) until hematuria resolved. Followup ranged from 9 to 60 months (mean 21). RESULTS: Hematuria resolved completely in 11 of 17 patients (64%), 2 had only residual microscopic hematuria, 2 had improvement but died of complications relating to cancer shortly after completion of treatment and 2 had recurrence of gross hematuria. Early application of hyperbaric oxygen was associated with earlier resolution of hemorrhagic cystitis. CONCLUSIONS: Radiation induced hemorrhagic cystitis that does not respond to standard regimens can be successfully treated with hyperbaric oxygen. This modality is well tolerated even in patients debilitated by advanced cancer and blood loss. Long-term remission can be achieved in the majority of patients.

Aged↗
PubMed1998

The structure and autonomic innervation of the vesico-ureteric junction in cases of primary ureteric reflux.

OBJECTIVE: To determine the histological structure and autonomic innervation of the vesico-ureteric junction (VUJ) in cases of primary ureteric reflux, to compare the results with those reported previously for non-refluxing VUJs and thus determine possible structural anomalies which could be responsible for vesico-ureteric reflux (VUR). MATERIALS AND METHODS: Nineteen specimens of VUJs with reflux were obtained from four males and 10 females undergoing ureteric reimplantation. Serial frozen sections were cut and stained either with Masson's trichrome or immunostained for protein gene product (PGP 9.5), a general nerve marker, dopamine beta hydroxylase (D beta H), a marker for noradrenergic nerves, or neuropeptide Y (NPY). RESULTS: Longitudinally orientated muscle bundles of narrow diameter accompanied the ureter to its termination at the ureteric orifice. Where they merged with those of the superficial trigone. In some specimens, an additional muscle component was identified, situated on the outer aspect of the ureteric muscle coat, consisting of an incomplete layer of distinctive muscle whose constituent cells formed an interlacing mesh-work. Occasionally, specimens included detrusor muscle which consisted of relatively large diameter compact bundles separated from the ureter by a connective tissue sheath. D beta H- and NPY-immunoreactive (-IR) nerves were numerous among the ureteric muscle bundles. Many NPY-IR nerves occurred within the detrusor muscle while D beta H-IR nerves were mainly perivascular. When present, the outer muscle component was richly innervated by both D beta H- and NPY-IR nerves. PGP immunoreactivity varied among regions in the same section, PGP-IR nerves frequently being less numerous than those containing D beta H or NPY. CONCLUSION: These results indicate that the morphology of the VUJ in cases of VUR is indistinguishable from the normal VUJ described previously. Furthermore, the density and distribution of D beta H- and NPY-IR nerves is identical to that in controls. However, the antigenicity of PGP in the reflux specimens appears to be masked in some regions by an unknown factor.

Autonomic Nervous System↗
PubMed1998

Breakfast and cognition: an integrative summary.

In this supplement, the papers presented at the International Symposium on Breakfast and Performance in Napa, CA in 1995 are summarized and integrated with data published since that time. In particular, the focus is on issues of research design, measurements, mechanisms, potential effect modifiers (eg, age), and relevance for public policy. No definitive conclusions can be drawn from the existing data on either the long- and short-term benefits of breakfast on cognition and school learning or the mechanisms that mediate this relation. The pooled data suggest that omitting breakfast interferes with cognition and learning, an effect that is more pronounced in nutritionally at-risk children than in well-nourished children. At the very least, breakfast consumption improves school attendance and enhances the quality of the students' diets.

Child↗
PubMed1998

Combined bladder closure and epispadias repair in the reconstruction of bladder exstrophy.

PURPOSE: Children with bladder exstrophy in whom initial closure fails are less likely to achieve adequate bladder capacity for later bladder neck reconstruction and continence. Repeat bladder closure may be combined with epispadias repair as initial management, decreasing the need for repeat anesthesia as well as providing increased outlet resistance to permit bladder growth in preparation for later bladder neck reconstruction. We compared results in boys who underwent combined bladder closure and epispadias repair or staged reconstruction. MATERIALS AND METHODS: A total of 16 boys with a mean age of 22 months with bladder exstrophy were referred for bladder closure after previous closure had failed in 15 and for delayed primary closure in 1. Osteotomies were performed in all patients, with bladder closure and epispadias repair as initial treatment. Results were compared to those in 21 boys with a mean age of 26 months in whom exstrophy closure had failed, and who underwent standard staged reconstruction by repeat closure followed by epispadias repair and subsequent bladder neck reconstruction in those who achieved adequate bladder capacity. RESULTS: At a mean followup of 87 months fistula rates were similar in the 2 groups. Eventual bladder neck reconstruction was possible in 69% of the patients in each group. In addition, 2 boys in the combined repair group achieved continence before bladder neck reconstruction was performed. CONCLUSIONS: We recommend epispadias repair combined with bladder exstrophy closure for treating failed exstrophy closure or late initial closure. Operative complications and results are comparable to those in patients in whom previous exstrophy closure failed and who undergo standard staged repair.

Abnormalities, Multiple↗
PubMed1998

Cloacal exstrophy--improving the quality of life: the Johns Hopkins experience.

PURPOSE: Exstrophy of the cloaca is a multisystem anomaly involving the gastrointestinal, nervous, musculoskeletal and genitourinary tracts which should be managed with a multidisciplinary approach. Improvement in management has led to survival for the majority of infants, and the focus has shifted to improvement in quality of life. The experience with management of cloacal exstrophy at a large center is evaluated. MATERIALS AND METHODS: Demographic data as well as functional results of management of the multiple anomalies in 37 patients with cloacal exstrophy were evaluated. Surgical reconstruction was aimed at providing the best functional and cosmetic results. RESULTS: Average patient age at review was 13.6 years. Most patients (32 of 37) had undergone an initial attempt at bladder closure from birth to greater than 24 months of age. Colostomy was performed when possible and if initial ileostomy was performed, the bowel was augmented later with the hindgut segment. When the hindgut segment was not used for bowel reconstruction, it was preserved for bladder augmentation or genital reconstruction. While urinary continence was achievable in many children, it was usually after augmentation and/or continent diversion. CONCLUSIONS: Improvements in perinatal management have increased survival in cloacal exstrophy. Therefore, the focus of reconstruction has shifted to reduction in the numbers of incontinent stomas, assistance with ambulation and improved cosmesis. All of these goals are achievable using a multidisciplinary approach to the management of this complex anomaly.

Abnormalities, Multiple↗
PubMed1998

Hernia development in CAPD patients and the effect of 2.5 l dialysate volume in selected patients.

The aim of this study was to estimate the prevalence of hernia formation in CAPD patients and to study the effect of increased dialysate volume (2.5 l) in selected population of patients who could tolerate it. We reviewed the charts of 454 individuals treated with CAPD in our center during a five-year period (September 1991-September 1996). Out of 404 patients who used 2.0 l dialysate exchange volume forty-nine (11%) developed hernia (umbilical 53%, inguinal 33%, incisional 14%) after having been on CAPD for an average of 10 +/- 11 months, while only one of the 50 patients who would tolerate 2.5 l developed a hernia (inguinal 2%), after having been on CAPD for 12 months. All hernias were repaired surgically and most of the patients returned to CAPD after temporary intermittent peritoneal dialysis. Age, sex, nutritional status, polycystic kidneys, and diabetes do not seem to be predisposing factors for hernia formation, while previous operation for aortic abdominal aneurysm repair, or low body weight (< 60 kg) were risk factors. The use of increased dialysate volume (2.5 l) in patients who could tolerate it, did not result in a higher frequency of hernia development. Surprisingly, patients with hernias seem to have a higher mortality than those without.

Adult↗
PubMed1997

Increased G alpha q/11 immunoreactivity in postmortem occipital cortex from patients with bipolar affective disorder.

As disturbances in guanine nucleotide binding (G) protein-coupled phosphoinositide second messenger systems have been implicated in bipolar disorder, we examined whether the abundance of G alpha q/11 and phospholipase C (PLC)-beta 1 two key transducing proteins in this signaling pathway, are altered in this disorder. Compared with the controls, immunoreactive levels of G alpha q/11 were significantly elevated by 62% (p = .047) in occipital cortex of bipolar subjects. A similar increase (52%) in the PLC-beta 1 immunolabeling was also found in the occipital cortex of the bipolar subjects, but only reached marginal statistical significance (p = .07). In contrast, frontal and temporal cortex G alpha q/11 or PLC-beta 1 immunolabeling did not differ between bipolar and control subjects. Cerebral cortical immunoreactive levels of G beta 1 or G beta 2, included as a negative control, were not different between comparison groups. These findings support and extend earlier observations suggesting that disturbances in G protein-coupled second messenger signaling pathways may play an important role in the pathophysiology of bipolar affective disorder.

Adult↗
PubMed1997

Initial experience with the modified vaginal wall sling in the treatment of female stress urinary incontinence.

From March 1995 to March 1996 24 women aged 29-73 years with stress urinary incontinence underwent a modified vaginal wall sling procedure following videourodynamic evaluation. Of these 24, 2 had stress urinary loss due to urethral hypermobility (UH), 3 had intrinsic sphincter deficiency (ISD) and 19 had both UH and ISD. Thirteen (54%) had preoperative urge incontinence, 13 (54%) had associated pelvic floor weakness, including cystocele, and 12 (50%) had had previous pelvic surgery and bladder neck suspension. Twenty-two patients were evaluable for a mean follow-up of 14 months (range 9-21 months). Stress urinary incontinence was resolved in all patients (100%). Of the patients with preoperative urge symptoms, 58% reported resolution but in 42% the urge symptoms remained unresolved. One new patient developed urge and occasional urge incontinence. Out of 22 patients 20 (90.9%) are totally continent; 2 (9.1%) are incontinent and both have documented detrusor instability and occasionally wear pads. The vaginal wall sling is an ideal procedure for the treatment of the various forms of stress urinary incontinence in women. In our series the early results indicate excellent patient acceptability and continence. Long-term follow-up will determine the durability of the procedure.

Adult↗
PubMed1997

Immunohistochemical and ultrastructural study of rhabdosphincter component of the prostatic capsule.

PURPOSE: There has been no complete agreement on functional anatomy of muscular components of the urethral sphincteric mechanism, particularly in the male patient. The prostatic capsule was studied to define its histological structure and to determine whether its rhabdosphincter component (prostatocapsular rhabdosphincter) consists only of slow twitch or slow and fast twitch striated myofibers. MATERIALS AND METHODS: We studied 11 whole prostates, including 1 obtained at autopsy and 10 by radical prostatectomy. Samples of prostatic capsule from 4 operative specimens were studied by electron microscopy. Whole mount paraffin sections from transverse slices of the remaining 7 prostates were double labeled with avidin biotin conjugate immunostaining using the primary monoclonal antibodies anti-alpha smooth muscle actin plus anti-alpha sarcomeric actin (all striated myofibers) or antiskeletal myosin fast (fast myofibers only). Tissue components of the prostatic capsule, including smooth muscle and slow versus fast twitch striated myofibers, were quantified by computerized image analysis. RESULTS: The prostatic capsule consisted of collagen, smooth muscle and striated myofibers. It varied in thickness and proportion of the 3 components among specimens, and in each in relation to transverse circumferential aspect and craniocaudal (horizontal) level of the prostate. Collagen and smooth muscle were equally important components. Striated muscle elements within the capsule consisted of fast twitch and dominant slow twitch myofibers, and were much more abundant in the caudal (distal, lower) than the cranial (proximal, upper) half of the capsule, where they were deficient ventrally (anteriorly) and dorsally (posteriorly). The prostatocapsular rhabdosphincter thus had a butterfly-like appearance, with a thick posteriorly open ring at the apex and 2 thinner, divergent leaflets tapering toward the base at the bladder neck. The fast myofiber population decreased progressively from apex to base of prostate. CONCLUSIONS: Proof is provided for mixed slow and fast twitch myofiber structure of the prostatocapsular component of human male rhabdosphincter. Sustained (tonic) contraction of slow myofibers probably reinforces the role of urethral smooth muscle in maintaining continence during bladder filling. Swift contraction of fast myofibers that abound caudally in the capsule probably supplements urethral closure by the bulkier membranous urethral part of the rhabdosphincter in preventing leakage of urine under stress when voiding is imminent or willfully withheld.

Aged↗