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Biomedical subjects

J T Benson

Publications and source records attributed to J T Benson.

At least 37 records · Page 2Linked to original sources
PubMed1999

Female pelvic organ prolapse: diagnostic contribution of dynamic cystoproctography and comparison with physical examination.

OBJECTIVE: The aim of this study was to assess the contribution of dynamic cystoproctography to the evaluation of female pelvic organ prolapse and to compare this contribution with that of physical examination. MATERIALS AND METHODS: The presence or absence of rectocele, enterocele, sigmoidocele, and cystocele on physical examination and on cystoproctography was retrospectively analyzed in 170 consecutive patients. For each of these diagnostic methods, organ prolapse was graded as small, moderate, or large on the basis of specific, defined measurements. RESULTS: A rectocele was detected by proctography in 155 patients (91%); 119 (77%) of these rectoceles were also found on physical examination. Barium trapping at proctography was related to rectocele size. Proctography showed an enterocele in 47 patients (28%); 24 (51%) of these enteroceles were also found on physical examination. Physical examination also found 44 enteroceles that could not be corroborated radiologically. At proctography, the enteroceles were relatively large, extending an average of 7.3 cm below the vaginal apex. Eight patients had sigmoidoceles, none of which were found on physical examination. A cystocele was shown by cystoproctography in 159 patients (94%); 132 (83%) of these cystoceles were also found on physical examination. CONCLUSION: The correlation between finding prolapsed pelvic organs on dynamic cystoproctography and finding them on physical examination varies. Most radiographically detected rectoceles and cystoceles are found on physical examination, whereas the correlation for enteroceles and sigmoidoceles is poor. Dynamic cystoproctography provides direct visualization and quantification of female pelvic organ prolapse, information that usually can only be inferred by physical examination.

Adult↗
PubMed1998

Urethral sphincter needle electromyography in women: comparison of periurethral and transvaginal approaches.

Needle electromyography (EMG) of the striated urethral sphincter is the only technique that permits detection of individual motor unit action potentials (MUAPs) and is a valuable diagnostic tool in the evaluation of women with urinary incontinence and voiding disorders. The purpose of this study was to compare two methods of urethral needle EMG with respect to the number of MUAPs identified, the amount of patient discomfort, and the duration of the examination. Twenty consecutive women referred for electrodiagnostic testing to evaluate symptoms of urinary incontinence and/or voiding dysfunction underwent both methods of the needle examination in a prospective randomized cross-over study design with each patient acting as her own control. A full cross-over analysis was conducted to detect period and sequence effects using analysis of variance with a power of 0.85 and a significance level of P < 0.05. Twice as many MUAPs were identified using the periurethral approach (8.8 versus 3.9) with a mean difference of 5.0 (P=0.0008). There was a non-significant trend to greater patient discomfort with the periurethral approach; however, the discomfort was generally rated as mild to moderate. The length of time required to count all identifiable MUAPs did not vary significantly between the two methods. We conclude that the periurethral approach is superior to the transvaginal approach with respect to the quantity of electrodiagnostic information obtained and propose that this method be standardized to characterize more accurately the neurogenic component of urinary incontinence and voiding dysfunction for future electrodiagnostic studies.

Action Potentials↗
PubMed1997

A prognostic model for the outcome of liver transplantation in patients with cholestatic liver disease.

We studied the outcome of 436 patients with primary biliary cirrhosis (PBC) or primary sclerosing cholangitis (PSC) who underwent orthotopic liver transplant (OLT) at three major liver transplant centers. Univariate predictors of outcome included age, Karnofsky score, Child's class, Mayo risk score, United Network for Organ Sharing (UNOS) status, nutritional status, serum albumin, serum bilirubin, international normalized ratio, and the presence of ascites, encephalopathy, renal failure (serum creatinine > 2 mg/dL), and edema refractory to diuretics. Using these predictors, we developed a four variable mathematical prognostic model to help the liver transplant physician predict the following: 1) the amount of intraoperative blood loss; 2) the number of days in the intensive care unit (ICU); and 3) severe complications after surgery. The model uses age, renal failure, Child's class, and United Network for Organ Sharing status. This study is the first to model the outcome of liver transplant in patients with a specific etiology of chronic liver disease (PBC or PSC). The model may be used to help select patients for OLT and to plan the timing of their transplantation.

Analysis of Variance↗
PubMed1997

Transvaginal electrical stimulation for female urinary incontinence.

OBJECTIVE: Our purpose was to determine the objective and subjective efficacy of transvaginal electrical stimulation for treatment of common forms of urinary incontinence in women. STUDY DESIGN: A prospective, double-blind, randomized clinical trial included 121 women with either urinary incontinence caused by detrusor instability or genuine stress incontinence, or both (mixed incontinence). Participants used the assigned device for 8 weeks. Identical preintervention and postintervention assessment included multichannel urodynamic testing, quality-of-life scale, and urinary diaries. RESULTS: A total of 121 women completed this study at four North American urogynecology centers. Detrusor instability was cured (stable on provocative cystometry) in 49% of women with detrusor instability who used an active electrical device (p = 0.0004, McNemar's test), whereas there was no statistically significant change in the percentage with detrusor instability in the sham device group. There was no statistically significant difference between the preintervention and postintervention rates of genuine stress incontinence for either the active device group or the sham device group. CONCLUSION: This form of transvaginal electrical stimulation may be effective for treatment of detrusor overactivity, with or without genuine stress incontinence.

Adult↗
PubMed1996

Levator ani muscle in women with genitourinary prolapse: indirect assessment by muscle histopathology.

The objective of this study was to assess the state of innervation in levator ani muscle sites using muscle histopathology. Asymptomatic women and patients with genitourinary prolapse were included. Histopathologic analysis allows indirect assessment of a muscle's innervation. Therefore, levator ani muscle was collected in a standardized fashion during abdominal surgery and frozen in the operating room using isopentane slush cooled by liquid nitrogen. Serial sections of levator ani muscle in cross-section were studied with standard histochemical and immunohistochemical techniques. The staining patterns from these histochemical techniques allowed quantitative determination of the ratios of fiber types I, IIA, and IIB and their fiber diameters. Objective assessment of fiber type grouping was performed. The distribution of both fiber type percentage and diameter were non-parametric. Therefore, the Mann-Whitney U-test was used to analyze the data for statistical differences between the means for these variables. There was no statistical difference in levator ani muscle fiber type percentage and diameter in patients with prolapse and/or urinary incontinence when compared to asymptomatic women. Levator ani muscles have a higher proportion of slow fibers (66%) than found in other human female muscle (48%). There was no evidence for denervation/reinnervation in any of the biopsy specimens. In this study, levator ani muscle biopsies from incontinent and/or prolapse patients were neither denervated nor reinnervated.

Adult↗
PubMed1996

Vaginal versus abdominal reconstructive surgery for the treatment of pelvic support defects: a prospective randomized study with long-term outcome evaluation.

OBJECTIVES: Our purpose was to determine whether a vaginal or abdominal approach is more effective in correcting uterovaginal prolapse. STUDY DESIGN: Eighty-eight women with cervical prolapse to or beyond the hymen or with vaginal vault inversion > 50% of its length and anterior vaginal wall descent to or beyond the hymen were randomized to a vaginal versus abdominal surgical approach. Forty-eight women underwent a vaginal approach with bilateral sacrospinous vault suspension and paravaginal repair, and 40 women underwent an abdominal approach with colposacral suspension and paravaginal repair. Ancillary procedures were performed as indicated. Detailed pelvic examination was performed postoperatively by the nonsurgeon coauthor yearly up to 5 years. The women were examined while standing during maximum strain. Surgery was classified as optimally effective if the woman remained asymptomatic, the vaginal apex was supported above the levator plate, and no protrusion of any vaginal tissue beyond the hymen occurred. Surgical effectiveness was considered unsatisfactory if the woman was symptomatic, the apex descended > 50% of its length, or the vaginal wall protruded beyond the hymen. RESULTS: Eighty women (vaginal 42, abdominal 38) were available for evaluation at 1 to 5.5 years (mean 2.5 years). The groups were similar in age, weight, parity, and estrogen status, and 56% had undergone prior pelvic surgery. There was no significant difference between the groups in morbidity, complications, hemoglobin change, dyspareunia, pain, or hospital stay. The vaginal group had longer catheter use, more urinary tract infections, more incontinence, decreased operative time, and lower hospital charge. Surgical effectiveness was optimal in 29% of the vaginal group and 58% of the abdominal group and was unsatisfactory leading to reoperation in 33% of the vaginal group and 16% of the abdominal group. The reoperations included procedures for recurrent incontinence in 12% of the vaginal and 2% of the abdominal groups. The relative risk of optimal effectiveness by the abdominal route is 2.03 (95% confidence interval 1.22 to 9.83), and the relative risk of unsatisfactory outcome using the vaginal route is 2.11 (95% confidence interval 0.90 to 4.94). CONCLUSIONS: Reconstructive pelvic surgery for correction of significant pelvic support defects was more effective with an abdominal approach.

Abdomen↗
PubMed1995

Effect of enteric nonnutrient infusions on motor patterns in neurally intact and neurally isolated canine jejunum.

Previous work in our laboratory has shown that nonnutrient mechanical factors initiate changes in motility patterns in local and remote regions of the small intestine. Our aims were to determine how isolated duodenal and jejunoileal nonnutrient infusions alter interdigestive motor patterns locally and distantly and whether these effects are neurally mediated. Ten dogs were prepared with duodenal and proximal jejunal infusion and manometry catheters and a proximal jejunal diverting cannula. Five of these dogs served as neurally intact controls (Group 1) and five also underwent in situ neural isolation of the entire jejunoileum (Group 2: extrinsic denervation; disruption of enteric myoneural continuity with duodenum). After recovery, nonnutrient infusions at 0-15 ml/min for 5 hr into proximal duodenum or jejunum did not consistently affect cycling of the migrating motor complex (MMC). The period and duration of individual phases of the MMC and time to first phase III after the start of infusion were similar in both groups. In Group 2, duodenal characteristics (period and duration of phase II, time to first phase III) increased slightly with increasing rates of jejunal but not duodenal infusion. Motility indices, although greater in Group 2, were not altered by enteric infusions. Differing rates of nonnutrient enteric flow limited to duodenum or jejunoileum did not affect markedly local or distant motor patterns. Alterations in interdigestive motility patterns by postprandial nonnutrient intraluminal content are not mediated directly by intraluminal flow.

Animals↗
PubMed1994

Neurophysiology of the female pelvic floor.

The neurogenic theory of female pelvic floor dysfunction suggests a common thread for malfunction of pelvic visceral and support activities. Support for the neurogenic hypothesis has been promoted by recent literature showing that more central neuropathic processes, such as in the cauda equina or pelvic plexus, can be associated with the previously described peripheral neuropathies and are linked to pelvic floor disorders. Damage by vaginal dissection has been suggested as another etiologic factor. This concept has further been supported by studying the effects of pudendal nerve blockade. Methods for investigating pelvic floor neurophysiology are becoming more refined and widespread, and therapeutic horizons are described including nerve stimulation and surgical therapy of nerve compression.

Electromyography↗
PubMed1994

Randomized double-blind trial of terodiline in the treatment of urge incontinence in women.

OBJECTIVE: To evaluate the effects of terodiline in women with urge incontinence. METHODS: After a 2-week run-in period, 93 women with urinary frequency and urge incontinence were randomized to either placebo or terodiline, 25 mg twice daily, in a double-blind study for 4 weeks. Symptoms were evaluated using daily frequency-volume charts to record voiding frequency, number of incontinent episodes, absorbent pad use, and quality of life. RESULTS: The terodiline group showed a 70% decrease in the mean (+/- standard deviation) number of incontinent episodes per week (15.8 +/- 24, decreasing to 4.9 +/- 11.9; P < .01), which persisted throughout the study period. The placebo group achieved a 9% reduction in the mean number of incontinent episodes (13.0 +/- 11.3, decreasing to 11.9 +/- 16; P < .05) only in the final week of treatment. Side effects, especially anticholinergic side effects, were more common in the terodiline group, but resulted in only one dropout. Both the treated and placebo groups improved in daytime frequency and quality-of-life indices. CONCLUSION: Terodiline is well tolerated and effective in reducing urge incontinent episodes in women.

Butylamines↗
PubMed1994

Absorption of simple nutrients from the in vivo neurally isolated canine jejunum and ileum.

BACKGROUND: The effects of intestinal transplantation on enteric absorptive function are not well understood. Our aim was to determine the effects of in situ isolation of the jejunoileum, a large animal model of jejunoileal autotransplantation, on absorption of simple nutrients from the jejunum and ileum separately. METHODS: Four groups of dogs were prepared with modified Thiry-Vella loops: group 1, neurally intact jejunum; group 2, neurally isolated jejunum; group 3, neurally intact ileum; and group 4, neurally isolated ileum. Intestinal loops were perfused with five different isosmolar solutions of NaCl alone, 30 mmol/L glucose, 2.5 mmol/L glycine, 2.5 mmol/L phenylalanine, and 5 mmol/L oleic acid at 1 to 2 weeks and 8 to 9 weeks after operation. RESULTS: Net absorption of water and electrolytes, glucose, glycine, phenylalanine, and oleic acid were not different statistically between neurally intact and neurally isolated intestinal loops at either time point. Ileal loops absorbed more than jejunal loops. CONCLUSIONS: Absorption of simple nutrients from the canine jejunum and ileum is not altered by this model of intestinal autotransplantation. These observations suggest that the extrinsic denervation that accompanies intestinal transplantation does not affect the transport systems for glucose, glycine, phenylalanine, or oleic acid.

Amino Acids↗
PubMed1994

Evacuation proctography (defecography): an aid to the investigation of pelvic floor disorders.

Patients with pelvic floor disorders frequently have associated anorectal dysfunction, which can be evaluated by a variety of laboratory tests. Evacuation proctography (defecography) documents the process of rectal evacuation and therefore demonstrates disorders of defecation, particularly those of an obstructive nature. It provides objective information about rectocele size and emptying and demonstrates coexistent enteroceles, many of which are missed on physical examination. This radiographic technique is the method of choice for recognizing rectal intussusception, the mechanism by which rectal prolapse occurs. Proctography suggests the diagnosis of spastic pelvic floor (anismus), a disorder amenable to biofeedback therapy. Proctography has limited application in anal incontinence unless there are associated obstructive symptoms. Evaluation of bladder dysfunction is aided by concomitant cystography. Gynecologists managing pelvic floor disorders should assess coexistent anorectal dysfunction, as undiagnosed enteroceles and disorders of defecation are an important cause of persistent or recurrent symptoms following pelvic floor repair. A comprehensive interdisciplinary approach to pelvic floor disorders is recommended.

Anal Canal↗
PubMed1993

The Q-tip test and urethrovesical junction mobility.

OBJECTIVE: To determine the accuracy of the Q-tip test to measure urethrovesical junction mobility. METHODS: One hundred fourteen women with urinary incontinence or genital prolapse were evaluated with a Q-tip test and perineal ultrasound scanning to measure urethrovesical junction mobility with strain. The sensitivity, specificity, and positive and negative predictive values of the Q-tip test to diagnose urethrovesical junction hypermobility were calculated using ultrasound as the standard. Repeat Q-tip and ultrasound measurements were obtained in ten subjects and analyzed for reproducibility. RESULTS: The Q-tip test had a sensitivity of 25%, specificity of 78%, positive predictive value of 67%, and negative predictive value of 37%. The Q-tip and ultrasound measurements were reproducible, as the within-subject variation was significantly small when compared to between-subject variation (P = .0001). CONCLUSION: The Q-tip test is inaccurate for measurement of urethrovesical junction mobility and should not be used in the manner described to diagnose urethrovesical junction hypermobility.

Female↗
PubMed1993

Intravaginal maximal electrical stimulation in the treatment of urinary incontinence.

Urinary incontinence imposes a large economic burden, estimated at $10 billion per year. As the cost of health care continues to rise, conservative therapeutic measures are becoming more attractive. Anecdotal reports suggest that electrical stimulation may be up to 87% effective in the treatment of urinary incontinence. Investigators use different stimulation devices and protocols and make a comparison of results difficult. The true efficacy of electrical stimulation for the treatment of urinary incontinence is unknown since there have been no controlled clinical trials. Within our referral-based urogynecology practice, we employ intermittent, intravaginal maximal electrical stimulation in conjunction with bladder drills and pelvic floor exercises. Over a one-year period we treated 76 women with urinary incontinence: 19 with stress incontinence (SUI), 30 with detrusor instability (DI) and 27 with mixed incontinence (MI). After six weeks, our overall objective improvement rate was 76%; 89% of patients with SUI, 73% with DI and 70% with MI met the criteria for improvement. Long-term follow-up averaged 6 months, with a range of 2-12. Of patients who showed an initial objective improvement, 87% maintained that improvement. Intravaginal electrical stimulation may be effective therapy for urinary incontinence. Controlled clinical trials are needed to determine its efficacy and standardize stimulation protocols before its widespread use.

Adult↗
PubMed1993

The effect of vaginal dissection on the pudendal nerve.

OBJECTIVE: To determine the effect of vaginal dissection on the pudendal nerve. METHODS: Pudendal and perineal nerve terminal motor latencies were measured before and at least 6 weeks after either abdominal or vaginal surgery for genital tract prolapse with or without urinary and fecal incontinence. Forty-eight women were studied prospectively in a randomized, blinded fashion. RESULTS: All women in this study had pelvic floor prolapse, and their mean preoperative pudendal and perineal nerve terminal motor latencies were prolonged compared to previously established normal values. The 27 women undergoing vaginal dissection demonstrated significant mean increases in pudendal nerve terminal motor latency (0.63 milliseconds, 95% confidence interval [CI] 0.33-0.93; P = .001) and perineal nerve terminal motor latency (1.33 milliseconds, 95% CI 0.80-1.86; P = .0001). In the 21 who had abdominal operations without vaginal dissection, essentially no mean change was noted. Clinically significant increases (more than 2 standard deviations) in pudendal or perineal nerve terminal motor latency occurred in 20 women (74%) in the vaginal dissection group and in seven women (33%) in the abdominally operated group. The odds ratio of producing such neuropathy by vaginal dissection compared to operating abdominally without vaginal dissection was 5.78 (95% CI 1.6-20). CONCLUSIONS: All women had abnormal preoperative pudendal nerve function, supporting previous reports linking pudendal neuropathy with pelvic floor prolapse. Pelvic floor surgery involving vaginal dissection produces neuropathy of the pudendal nerve as measured by terminal motor latency.

Abdomen↗