Biomedical subjects

D A Rivas

Publications and source records attributed to D A Rivas.

64 records · Page 4Linked to original sources

PubMed1994

Cystoscopic autogenous fat injection treatment of vesicoureteral reflux in spinal cord injury.

The purpose of this investigation was to determine the safety and efficacy of subtrigonal, periureteral injections of autogenous fat grafts for the treatment of vesicoureteral reflux. Seven patients (12 renal units) with vesicoureteral reflux were treated with subtrigonal autogenous fat injection. Fat harvesting was obtained from abdominal and thigh subcutaneous tissue. Approximately 2 ml of fat was injected beneath each ureteral orifice with a modified 10 Fr needle through a 23.5 Fr rigid cystoscope. Two of the seven patients experienced durable (six months) resolution of reflux. In three patients, reflux resolved but recurred within three months and another developed recurrent reflux within six months. In one patient with a periureteral diverticulum, proper positioning of the needle tip for effective fat injection was not possible, resulting in persistent reflux. Two of the five patients with persistent reflux demonstrated a diminished grade of reflux on follow-up cystography. Neither complications nor ureteral obstruction have been encountered. The subtrigonal injection technique can be used with autogenous adipose tissue to treat vesicoureteral reflux. Anatomic variation may determine those patients less likely to enjoy durable results. Clinical success and reabsorption of the fat cannot be predicted or controlled at the present time. The ideal periureteral bulking agent for the treatment of vesicoureteral reflux remains to be determined.

Adipose Tissue↗

PubMed1994

Complications associated with the use of vacuum constriction devices for erectile dysfunction in the spinal cord injured population.

The vacuum constriction device has generally been regarded as a safe and effective alternative to pharmacologic intracorporal injections or surgical placement of a penile prosthesis for the treatment of erectile dysfunction. This paper serves to exemplify the potential complications of the device when used to treat erectile dysfunction in the spinal cord-injured (SCI) population. Two cases of subcutaneous penile hemorrhage in patients using anticoagulant therapy (one treated with subcutaneous heparin and one with coumadin) and one case of penile gangrene occurred in three different SCI males. Physicians managing erectile dysfunction in SCI patients should be aware of these potential serious morbidities. The management and means of prevention of these complications are presented.

Adult↗

PubMed1994

DDAVP in the urological management of the difficult neurogenic bladder in spinal cord injury: preliminary report.

The purpose of this study is to determine the efficacy of desmopressin (DDAVP), a synthetic analogue of antidiuretic hormone, as an alternative therapy in the management of spinal cord injured (SCI) patients with neurogenic bladder dysfunction unresponsive to conventional therapy. Seven SCI patients (three men and four women) were treated with DDAVP after urodynamic evaluation. Despite treatment with anticholinergic agents, urodynamic evaluation demonstrated uninhibited detrusor contractions exceeding 30 cm H2O pressure at less than 300 ml cystometric capacity in all seven patients. Three patients had been managed with intermittent self-catheterization, but had socially unacceptable short intervals between catheterizations. Two women with incomplete injury were afflicted with significant nocturia (> 3 episodes/night). The remaining two patients managed with intermittent self-catheterization were troubled with nocturnal enuresis. The patients received 10 micrograms intranasal DDAVP once every 24 hours. Prior to DDAVP administration, the four patients who used DDAVP nightly experienced a median of four episodes of nocturia. After one month of DDAVP treatment, two patients had only one episode of nocturia per night and in the other two patients, nocturnal enuresis was completely eliminated. Three patients used daytime DDAVP administration at work to avoid frequent catheterization. The median period between bladder catheterizations increased from 2.5 hours before DDAVP to 6 hours while using DDAVP. Symptomatic improvement persisted during the follow-up period of 6-20 months (mean = 12). Side effects were infrequent; only one patient complained of transient headaches. Neither hyponatremia nor serum electrolyte abnormalities occurred. Our preliminary results suggest that DDAVP is safe and effective in the symptomatic management of complicated neurogenic bladder dysfunction in selected SCI patients.

Administration, Intranasal↗

PubMed1994

Prospective comparison of external sphincter prosthesis placement and external sphincterotomy in men with spinal cord injury.

The effectiveness and complications of the treatment of detrusor-external sphincter dyssynergia (DESD) and voiding pressure > 60 mm H2O using an endoluminal urethral sphincter prosthesis (Urolume) were compared with those of conventional external sphincterotomy in 46 men with spinal cord injury (SCI) (mean age 34 years; range 18-58 years). Twenty-six patients elected the Urolume, and 20 chose sphincterotomy. The age and level and duration of SCI were similar in the two groups. Follow-up ranged from 6 to 20 months. After prosthesis placement, voiding pressure dropped from 88 +/- 29 cm H2O to 38 +/- 22 cm H2O at 6 months (n = 23) and 35 +/- 16 cm H2O at 12 months (n = 18) (P < 0.001). The residual urine volume fell from 180 +/- 145 mL preoperatively to 85 +/- 125 mL at 12 months (P < 0.001), while the maximum cystometric capacity remained constant (P = 0.75). External sphincterotomy achieved similar statistically significant decreases in voiding pressure and residual urine volume, and bladder capacity was maintained. The preoperative and follow-up urodynamic measures were similar in the two groups. Prosthesis placement was associated with a significantly shorter operation (P = 0.001) and length of hospitalization (P = 0.01), a lower hospitalization cost (P = 0.01), and less bleeding (change in hemoglobin concentration) (P = 0.01) than external sphincterotomy. The complications of stent insertion were device migration (n = 4) and secondary bladder neck obstruction (n = 2). One patient with continuing reflux required bilateral ureteral implantation. The complications of sphincterotomy were bleeding necessitating transfusion (n = 2), recurrent obstruction (n = 2), and erectile dysfunction (n = 1). The sphincter prosthesis is as effective as sphincterotomy in the treatment of DESD, while being technically easier, less morbid, and less expensive.

Adult↗

PubMed1994

Similarity of the American Urological Association Symptom Index among men with benign prostate hyperplasia (BPH), urethral obstruction not due to BPH and detrusor hyperreflexia without outlet obstruction.

OBJECTIVE: To compare the specificity of the American Urological Association (AUA) Symptom Index for benign prostatic hyperplasia (BPH) versus other urodynamically verified micturitional dysfunction in men. PATIENTS AND METHODS: Fifty-seven consecutive men who had been referred for video-urodynamic evaluation of voiding symptoms were evaluated. The patients were divided into three groups: (i) BPH group (n = 24); (ii) non-BPH obstructed group (n = 20; nine bladder neck obstruction, 11 bulbous urethral stricture); and (iii) detrusor hyper-reflexia group: detrusor hyper-reflexia without outlet obstruction (n = 13). RESULTS: The mean AUA symptom score for the BPH group was 18.9 (range 7-28). The mean score for the 20 non-BPH obstructed group was 17.6 (range 4-28) and the mean score for the 13 men with detrusor hyper-reflexia was 20.5 (range 12-27). There was no statistical difference in the AUA symptom score among the three groups. CONCLUSION: The AUA Symptom Index does not specifically identify BPH or bladder outlet obstruction. The index cannot differentiate the site of obstruction as noted by the similar scores among men with BPH from those with bladder neck obstruction and urethral strictures. Moreover, The AUA Symptom Index scores are similar between men with voiding symptoms secondary to bladder dysfunction and bladder outlet obstruction.

Aged↗

PubMed1993

American Urological Association symptom index for women with voiding symptoms: lack of index specificity for benign prostate hyperplasia.

An evaluation of the American Urological Association (AUA) symptom index was recently published as a valid symptom score for benign prostatic hyperplasia (BPH). To determine the specificity prospectively of the index for BPH and bladder outlet obstruction, we chose to administer the index to 38 consecutive women with voiding symptoms who were previously scheduled for video urodynamic evaluation. In each case the index was self-administered before the urodynamic study. Index determination was then repeated 1 to 4 months after the institution of therapy. Only 3 of the 38 women demonstrated true urethral obstruction. One patient exhibited urethral compression after a pubovaginal sling urethral suspension, 1 with multiple sclerosis demonstrated detrusor external sphincter dyssynergia and 1 suffered bladder neck obstruction caused by a leiomyoma. The AUA symptom index for the 35 nonobstructed women ranged from 4 to 33 (mean 17.6) Of the women 15 scored between 8 and 18, while 14 had a score of greater than 18. The mean score decreased to 9.4 after the institution of therapy, which included bladder suspension surgery, anticholinergics, timed voiding and pelvic floor exercises. Of the 3 women with bladder outlet obstruction the mean score was 22.7 before and 11.0 after therapy. A greater decrease in the AUA symptom index occurred among the obstructed group after urological therapy compared to the nonobstructed group. Our results indicate that the AUA symptom index is not specific for BPH. The index score for the women in our study rivaled the scores reported for men with BPH.

Adult↗

PubMed1993

Neurological manifestations of baclofen withdrawal.

Baclofen is a central nervous system agent that is commonly used for the treatment of muscle spasticity in spinal cord injury patients. Acute withdrawal of this medication can induce the development of neurological symptoms, including seizure disorder, psychosis, hallucinations and visual disturbances. We report 3 cases of acute central nervous system symptoms that developed in spinal cord injury patients. Each patient had been chronically maintained on a baclofen regimen to control muscle spasticity. Symptoms developed shortly after baclofen therapy was interrupted following genitourinary surgery. It is important that urologists become familiar with the symptomatology of baclofen withdrawal, the methods of its prevention and the appropriate therapy should the syndrome develop.

Adult↗

PubMed1993

Clinical effect of alpha-1 antagonism by terazosin on external and internal urinary sphincter function.

The purpose of this investigation was to determine the effectiveness of alpha-1 blockade in the treatment of bladder outlet obstruction in the spinal cord injured (SCI) patient. We evaluated terazosin, a selective alpha-1 blocker, in 15 normotensive SCI patients. Detrusor-external sphincter dyssynergia (DESD), without obstruction of the bladder neck or prostate, was documented in all patients using video-urodynamic evaluation. Urodynamic testing was performed both before and during treatment with terazosin (5 mg nightly). Voiding pressure before and during terazosin therapy averaged 92 +/- 17 and 88 +/- 27 cm H2O, respectively (p = 0.48). After subsequent external sphincterotomy or sphincter stent placement, the voiding pressure was reduced to 38 +/- 15 cm H2O (p < 0.001). Nine other patients suffered from persistent difficulty voiding after previous sphincterotomy. Each was subsequently treated with oral terazosin. In five patients who improved with this treatment, urodynamic parameters demonstrated obstruction only at the bladder neck, with no evidence of obstruction at the level of the external sphincter. The four patients who failed to improve were documented to have an open bladder neck but obstruction at the level of the external sphincter. Our data show that alpha-1 sympathetic blockade has no effect on external sphincter function and does not significantly relieve functional obstruction caused by DESD. It was also noted that terazosin is helpful in diagnosing and treating internal sphincter (bladder neck and prostate) obstruction especially in patients who have persistent difficulty voiding after external sphincterotomy.

Adolescent↗

PubMed1993

Flexible cystoscopy during urodynamic evaluation of spinal cord-injured patients.

Eighty-one consecutive flexible cystoscopic examinations were performed on 69 patients with spinal cord injury (SCI) at the time of their urodynamic study. The indications for cystoscopy included hematuria, recurrent urinary tract infections, symptoms of bladder outlet obstruction, the presence of an intraurethral sphincter stent requiring evaluation, neurogenic vesical dysfunction requiring endourodynamic study (cystometrogram through the working port of the flexible cystoscope), or bladder calculi. Flexible cystoscopy was accomplished in all patients, whether lying supine or seated in a wheelchair (N = 16). Only 6 of 39 patients with previous episodes of autonomic dysreflexia became hypertensive during cystoscopy. When a urodynamic catheter could not be inserted, the flexible cystoscope was particularly useful in defining the urethral anatomy or obstruction and in performing endourodynamic evaluation. The only complication was the development of febrile urinary tract infection in four patients. The flexible cystoscope is a valuable tool in the urodynamic laboratory caring for patients with SCI and is effective for use in endourodynamics, especially when patient positioning or catheter placement is difficult. The procedure is well tolerated, causes minimal stimulation leading to the development of autonomic dysreflexia, and provides accurate cystometric data.

Adolescent↗

PubMedDate not supplied

Spermatogenesis in early and chronic phases of experimental spinal cord injury in the rodent model.

A rodent model was used to study the degree and dynamics of potential spermatogenic alterations during both acute and chronic phases after experimental spinal cord injury (SCI). Sexually mature Sprague-Dawley rats underwent controlled impact SCI by exposure of the thoracic spine, T-10 laminectomy, and intraoperative somatosensory-evoked potential latency and amplitude. A 50 gm-cm SCI was produced in 35 experimental subjects. Sham surgery was performed on 16 control subjects through exposure of the dura without weight drop. SCI was verified by obliteration of the somatosensory-evoked potential following injury and subsequent neurologic assessment (modified hindlimb Tarlov scale) 4 weeks after injury. Flow cytometry with acridine orange as the DNA probe was used to measure potential spermatogenic alterations in testicular cell development and integrity of epididymal sperm chromatin structure between 2 and 20 weeks following SCI. Flow cytometric analysis revealed that nine of the 35 SCI animals demonstrated altered spermatogenesis; it is not clear whether these effects are specific or nonspecific stress related. These responder animals contributed to dramatic differences in relative percent testicular haploid cells (spermatids) and concurrent differences in percent diploid cells at 2, 4, 8, 12, and 16 weeks. Percentages within the three spermatid populations (round, elongating, and elongated) also differed at these time points. The sperm chromatin structure assay (SCSA) revealed significant epididymal sperm nuclear structure differences at 2, 4, and 12 weeks (P < 0.001). These findings are in concordance with our clinical observations of spermatogenesis in spinal cord injured men and suggest that significant spermatogenic deficit may occur, even in the early phase of injury.

Acute Disease↗