Impact of Health Literacy on Satisfaction Following Male Prosthetic Surgery

OBJECTIVE

To determine whether a patient's health literacy impacts patient satisfaction following inflatable penile prosthesis (IPP) or artificial urinary sphincter (AUS) placement.

METHODS

A retrospective study of patients who underwent IPP or AUS between January 1^st 2016 and July 31^st 2020 was performed. A telephone questionnaire assessed overall satisfaction and if patients would undergo surgery again. Health literacy was measured using the Brief Health Literacy Screen (BHLS). Multivariate ordinal logistic regression was used to assess the association between health literacy and patient satisfaction.

RESULTS

At a median follow up of 2.4 years, 113 (70%) of the 162 IPP patients were either satisfied or very satisfied with their procedure and 120 (74%) patients would undergo surgery again. Of the 76 AUS patients, 65 (86%) were either satisfied or very satisfied with their procedure and 65 (86%) patients would undergo surgery again. After adjustment for potential confounders, increasing BHLS score was significantly associated with satisfaction for both IPP (OR 1.31, 95% CI 1.11-1.54; p=0.001) and AUS surgery (OR 1.25, 95% CI 1.02-1.56; p=0.034), as well as with likelihood of undergoing IPP surgery again (OR 1.53, 95% CI 1.25-1.87; p<0.001). BHLS was not associated, however, with likelihood of undergoing AUS surgery again (p=0.403).

CONCLUSIONS

Men with lower health literacy are less likely to be satisfied following prosthetic surgery. The BHLS is an important tool that can be used to identify patients who may benefit from increased preoperative counseling to improve patient expectations and quality of life following prosthetic surgery.

Are postoperative antibiotics necessary after artificial urinary sphincter insertion?

INTRODUCTION We sought to explore whether patients discharged without antibiotics after artificial urinary sphincter (AUS) insertion were more likely to require device explantation for infection or erosion compared to patients discharged with antibiotics at our institution and compared to patients in other large, contemporary series.

MATERIALS AND METHODS

AUS insertions performed at our institution between 2013 and 2017 were retrospectively reviewed to determine demographics, comorbidities, and perioperative and medium-term outcomes. Patients were grouped based on 1) known risk factors for infectious complications or erosion and 2) postoperative antibiotic prescription status. Patients were placed in Group 1 if they did not demonstrate risk factors and did not receive postoperative antibiotics, Group 2 if they did possess risk factors but did not receive postoperative antibiotics, and Group 3 if they had risk factors and received postoperative antibiotics.

RESULTS

Of the 155 men who met inclusion criteria, 44, 47, and 64 were categorized in Groups 1, 2, and 3, respectively. Median (IQR) follow up was similar across Groups 1, 2, and 3 (12.7 [4.6-25.1] versus 10.7 [4.5-31.3] versus 8.3 [4.4-26.4] months, p = 0.808). Rates of explantation due to device infection (0 versus 2 versus 6%, p = 0.172) or cuff erosion (2 versus 2 versus 8%, p = 0.253) did not vary significantly between Groups 1-3.

CONCLUSIONS

Patients undergoing AUS insertion may be unlikely to benefit from the routine administration of postoperative antibiotics. In light of the known consequences of antibiotic overuse, a randomized controlled trial is warranted.

Erectile Dysfunction Following Pelvic Fracture Urethral Injury

INTRODUCTION

Although pelvic fracture urethral injuries (PFUIs) are rare, approximately half these patients will report erectile dysfunction (ED) after their injuries. The anatomic relations of the cavernosal nerves and arteries to the bones of the pelvis and the urethra put these structures at significant risk at the time of PFUI. This review examines the epidemiology, evaluation, and management of ED in this patient population.

AIM

To evaluate the epidemiology, pathophysiology, diagnosis, and management of patients with ED after PFUI.

METHODS

A literature review was performed to identify articles on PubMed published before May 2017 addressing PFUI and ED.

MAIN OUTCOME MEASURES

Incidence, mechanisms, risk factors, evaluation, and management strategies of ED after PFUI were analyzed.

RESULTS

Patients with pelvic fractures are at risk of post-injury ED, whereas those with PFUI appear to be at even higher risk. Different potential mechanisms contributing to the pathophysiology of ED in this setting have been described in the literature, including damage to the nervous supply to the penis, arterial insufficiency, and veno-occlusive dysfunction. However, there is a lack of consensus on the predominant etiology. Appropriate diagnostic evaluation can help to elucidate the underlying pathophysiology on an individual basis and can help guide management. Oral therapies, intracavernosal injections, and inflatable penile prostheses have shown great success. Furthermore, unlike patients with ED from other causes, select patients with isolated arteriogenic ED are potentially eligible for penile revascularization procedures.

CONCLUSION

Because most patients with pelvic trauma are younger than 40 years with a significant life expectancy, appropriate diagnosis and management of ED after PFUI can greatly improve quality of life and allow resumption of post-injury sexual function. Identification of the causative pathology can help tailor treatment on an individual basis. Johnsen NV, Kaufman MR, Dmochowski RR, Milam DF. Erectile Dysfunction Following Pelvic Fracture Urethral Injury. Sex Med Rev 2018;6;114-123.

Cost-effective management of pelvic fracture urethral injuries

PURPOSE

To compare the cost-effectiveness of various treatment strategies in the management of pelvic fracture urethral injuries using decision analysis.

METHODS

Five strategies were modeled from the time of injury to resolution of obstructed voiding or progression to urethroplasty. Management consisted of immediate suprapubic tube (SPT) placement and delayed urethroplasty; primary endoscopic realignment (PER) followed by urethroplasty in failed patients; or PER followed by 1-3 direct vision internal urethrotomies (DVIU), followed by urethroplasty. Success rates were obtained from the literature. Total medical costs were estimated and incremental cost-effectiveness ratios (ICERs) were generated over a 2-year follow-up period.

RESULTS

PER was preferred over SPT placement in all iterations of the model. PER followed by a single DVIU and urethroplasty in cases of failure was least costly and used as the referent approach with an average cost-effectiveness of $17,493 per unobstructed voider. The ICER of a second DVIU prior to urethroplasty was $86,280 per unobstructed voider, while the ICER of a third DVIU was $172,205. The model was sensitive to changes in the success rate of the first DVIU, where when the probability of DVIU success is expected to be less than 32% immediate urethroplasty after failed PER is favored.

CONCLUSIONS

Management of pelvic fracture urethral injuries with PER is the preferred management strategy according to the current model. For those who fail PER, a single DVIU may be attempted if the presumed success rate is >32%. In all other cases, urethroplasty following PER is the preferred approach.

Evaluation of the axonics modulation technologies sacral neuromodulation system for the treatment of urinary and fecal dysfunction

INTRODUCTION

Sacral neuromodulation (SNM) remains one of the few effective treatments for refractory bladder and bowel dysfunction. However, SNM is associated with frequent need for surgical intervention, in many cases because of a failed battery. A rechargeable SNM system, with a manufacturer-reported battery life of 15 years or more, has entered post-market clinical testing in Europe but has not yet been approved for clinical testing in the United States. Areas covered: We review existing neuromodulation technologies for the treatment of lower urinary tract and bowel dysfunction and explore the limitations of available technology. In addition, we discuss implantation technique and device specifications and programming of the rechargeable SNM system in detail. Lastly, we present existing evidence for the use of SNM in bladder and bowel dysfunction and evaluate the anticipated trajectory of neuromodulation technologies over the next five years. Expert commentary: A rechargeable system for SNM is a welcome technological advance. However surgical revision not related to battery changes is not uncommon. Therefore, while a rechargeable system would be expected to reduce costs, it will not eliminate the ongoing maintenance associated with neuromodulation. No matter the apparent benefits, all new technologies require extensive post-market monitoring to ensure safety and efficacy.

An update on the use of transdermal oxybutynin in the management of overactive bladder disorder

Antimuscarinic medications are used to treat nonneurogenic overactive bladder refractory to nonpharmacologic therapy. Side effects such as dry mouth, constipation, blurred vision, dizziness, and impaired cognition limit the tolerability of therapy and are largely responsible for high discontinuation rates. Oxybutynin is a potent muscarinic receptor antagonist whose primary metabolite after first-pass hepatic metabolism is considered largely responsible for its associated anticholinergic side effects. Transdermal administration of medications bypasses hepatic processing. Specifically with oxybutynin, whose low molecular weight permits transdermal administration, bioavailability of the parent drug with oral administration is less than 10%, whereas with transdermal delivery is a minimum of 80%. The result has been an improved side effect profile in multiple clinical trials with maintained efficacy relative to placebo; however, the drug may still be discontinued by patients due to anticholinergic side effects and application site reactions. Transdermal oxybutynin is available as a patch that is changed every 3-4 days, a gel available in individual sachets, or via a metered-dose pump that is applied daily. The transdermal patch was briefly available as an over-the-counter medication for adult women, although at this time all transdermal formulations are available by prescription only.

Overactive bladder and autonomic dysfunction: Lower urinary tract symptoms in females with postural tachycardia syndrome

AIMS

Postural Tachycardia Syndrome (POTS) represents an autonomic disorder predominantly affecting females between 15 and 50 years of age. POTS is a chronic disorder (>6 months) characterized by an excessive heart rate increment on standing (>30 beats/min) in the presence of characteristic symptoms of cerebral hypoperfusion or sympathetic activation. Patients have clinically been noted to describe lower urinary tract symptoms (LUTS), although urologic symptoms have not been methodically assessed in the POTS population. Herein, we present data from a pilot study designed to identify and quantitate overactive bladder (OAB) in patients diagnosed with POTS.

METHODS

Patients admitted to the Vanderbilt Autonomic Dysfunction Center between June 2009 and October 2010 for evaluation for the potential diagnosis of POTS completed a validated, standardized questionnaire for OAB (OAB-q) at presentation. Symptom score and subscale analyses were conducted. Subscale health related quality of life (HRQL) scores were transformed into a 0-100 scale, with higher scores reflecting superior HRQL. Data are presented as mean ± SD.

RESULTS

Thirty-two females presented for evaluation of symptoms consistent with POTS. Twenty-nine women were subsequently diagnosed with POTS with 19 of these patients completing the OAB-q questionnaire (65.5% response rate). Average age was 33.5 ± 8.3 years. Symptom severity transformed score was 26.0 ± 16.4, with 13 of 19 patients (68.4%) meeting clinical criteria for diagnosis of probable clinically significant OAB. Nocturia was the most bothersome symptom, followed by increased daytime frequency and urgency.

CONCLUSIONS

This pilot study describes bothersome lower urinary tract dysfunction in patients presenting with POTS as assessed by patient-reported questionnaire data. Nocturia demonstrated the greatest negative impact on health-related quality of life (HRQL), while social interaction was the least affected HRQL domain. In patients with dysautonomia, this data provides a critical baseline for mechanistic insight into both disease-specific and global pathophysiology of nocturia and OAB. Neurourol. Urodynam. 36:610-613, 2017. © 2016 Wiley Periodicals, Inc.

A BACTERIOLOGICAL STUDY OF "COLDS" ON AN ISOLATED TROPICAL ISLAND (ST. JOHN, UNITED STATES VIRGIN ISLANDS, WEST INDIES

Studies in the Virgin Islands, Labrador, and Alabama, suggest that colds are incited by some specific agent with which we are not yet familiar. They suggest also that the secondary and more severe symptoms associated with colds may be due to certain aerobic flora commonly found in the nasopharynx. Types of pneumococci which are virulent (to white mice) and true Pfeiffer's bacilli requiring both V and X substance (and forming indol?) seem to be of particular importance in these secondary infections. The studies indicate that the specific agent which initiates colds is infectious in nature, and spread by direct contact, with an incubation period of 1 to 3 days. There is strong evidence that environmental factors, particularly reduction in atmospheric temperature, have some influence upon the incidence of colds.

Open renal biopsy: comorbidities and complications in a contemporary series

STUDY TYPE

Therapy (case series) Level of Evidence 4.

OBJECTIVE

To report the indications and outcomes of a contemporary series of patients with contraindications to percutaneous renal biopsies (PRBs) who had an operative RB (ORB), as although ORB is a relatively infrequent procedure, it remains an important and underreported operation.

PATIENTS AND METHODS

In a retrospective review of patients who had an ORB we examined comorbidities, indications, and 30-day morbidity and mortality. Preoperative comorbidities were stratified according to the Charlson comorbidity index.

RESULTS

In all, 115 patients had ORB between 1991 and 2006 (mean age 48 years, range 18-83); 60% of the patients were American Society of Anesthesiologists class >or=3. The median Charlson comorbidity index score was 3, with a score of 0 in 20.9%, 1-2 in 27.8%, 3-4 in 30.4% and >or=5 in 20.9% of patients. Indications for an ORB included morbid obesity, failed PRB, coagulopathy, and solitary kidney. In all, 47.8% of patients had a serum creatinine level of <3.0 mg/dL, 34.8% of >3.0 mg/dL and 17.4% were dialysis-dependent. There were 43 complications in 36 patients. The mortality rate after surgery was 0.8%. There were eight major complications in seven patients (6.1%) including cardiac arrest, stroke, sepsis, reoperation and re-intubation. There were minor complications 34 times in 31 patients (27%), the most common being wound infection, pneumonia, intraoperative transfusion of >2 units, arrhythmia, postoperative retroperitoneal bleed, and seep vein thrombosis.

CONCLUSIONS

This study shows that there are significant comorbidities in patients referred to urologists for an ORB. With a mortality rate of 0.8% and major and minor complication rates of 6.1% and 27%, respectively, the ORB, while infrequent, carries a significant risk in this population that should be included in preoperative decision making and used for patient counselling.

Results of sacral neuromodulation therapy for urinary voiding dysfunction: outcomes of a prospective, worldwide clinical study

PURPOSE

This 5-year, prospective, multicenter trial evaluated the long-term safety and efficacy of sacral neuromodulation in patients with refractory urge incontinence, urgency frequency and retention.

MATERIALS AND METHODS

A total of 17 centers worldwide enrolled 163 patients (87% female). Following test stimulation 11 patients declined implantation and 152 underwent implantation using InterStim. Of those treated with implantation 96 (63.2%) had urge incontinence, 25 (16.4%) had urgency frequency and 31 (20.4%) had retention. Voiding diaries were collected annually for 5 years. Clinical success was defined as 50% or greater improvement from baseline in primary voiding diary variable(s).

RESULTS

Data for all implanted cases were reported. For patients with urge incontinence mean leaking episodes per day decreased from 9.6 +/- 6.0 to 3.9 +/- 4.0 at 5 years. For patients with urgency frequency mean voids per day decreased from 19.3 +/- 7.0 to 14.8 +/- 7.6, and mean volume voided per void increased from 92.3 +/- 52.8 to 165.2 +/- 147.7 ml. For patients with retention the mean volume per catheterization decreased from 379.9 +/- 183.8 to 109.2 +/- 184.3 ml, and the mean number of catheterizations decreased from 5.3 +/- 2.8 to 1.9 +/- 2.8. All changes were statistically significant (p <0.001). No life threatening or irreversible adverse events occurred. In 102 patients 279 device or therapy related adverse events were observed. At 5 years after implantation 68% of patients with urge incontinence, 56% with urgency frequency and 71% with retention had successful outcomes.

CONCLUSIONS

This long-term study demonstrates that InterStim therapy is safe and effective for restoring voiding in appropriately selected cases refractory to other forms of treatment.

Management of refractory urinary urge incontinence following urogynecological surgery with sacral neuromodulation

AIMS

We sought to explore our patient outcomes utilizing sacral neuromodulation in the management of refractory urinary urge incontinence following urogynecological surgical procedures.

METHODS

A total of 25 women with urinary urge incontinence following urogynecological surgery were selected for SNS therapy and retrospectively analyzed. All patients completed a comprehensive urological evaluation. Clinical data was recorded to determine outcomes and identify parameters that would be predictive of response to neuromodulation. Outcomes were determined via subjective patient questionnaire and graded as follows: significant response (> or =80% improvement), moderate response (> or =50% and <80% improvement), and poor response (<50% response).

RESULTS

Nineteen patients had a previous pubovaginal sling (10 with concomitant pelvic prolapse repair), 3 a previous retropubic suspension, and 3 a transperitoneal vesicovaginal fistula repair. Urethrolysis was performed in 4 patients to alleviate bladder outlet obstruction prior to sacral neuromodulation. Mean patient age was 59.8 years and length of follow-up was 7.2 months. Twenty-two women (88%) had the IPG placed during a Stage 2 procedure. Twenty patients maintained at least a 50% improvement in clinical symptoms at last follow-up and 6 patients were continent. Overall, the number of pads/day improved from 4.2 to 1.1 (P < 0.001). There were no significant differences in response to neuromodulation based upon age, duration of symptoms, type of surgery, or urodynamic parameters.

CONCLUSION

Sacral neuromodulation appears to be an effective therapy in patients with refractory urge incontinence following urogynecological surgery. Larger prospective studies with longer follow-up are needed to assess the durability of this therapeutic modality.

The long-term effect of doxazosin, finasteride, and combination therapy on the clinical progression of benign prostatic hyperplasia

BACKGROUND

Benign prostatic hyperplasia is commonly treated with alpha-adrenergic-receptor antagonists (alpha-blockers) or 5alpha-reductase inhibitors. The long-term effect of these drugs, singly or combined, on the risk of clinical progression is unknown.

METHODS

We conducted a long-term, double-blind trial (mean follow-up, 4.5 years) involving 3047 men to compare the effects of placebo, doxazosin, finasteride, and combination therapy on measures of the clinical progression of benign prostatic hyperplasia.

RESULTS

The risk of overall clinical progression--defined as an increase above base line of at least 4 points in the American Urological Association symptom score, acute urinary retention, urinary incontinence, renal insufficiency, or recurrent urinary tract infection--was significantly reduced by doxazosin (39 percent risk reduction, P<0.001) and finasteride (34 percent risk reduction, P=0.002), as compared with placebo. The reduction in risk associated with combination therapy (66 percent for the comparison with placebo, P<0.001) was significantly greater than that associated with doxazosin (P<0.001) or finasteride (P<0.001) alone. The risks of acute urinary retention and the need for invasive therapy were significantly reduced by combination therapy (P<0.001) and finasteride (P<0.001) but not by doxazosin. Doxazosin (P<0.001), finasteride (P=0.001), and combination therapy (P<0.001) each resulted in significant improvement in symptom scores, with combination therapy being superior to both doxazosin (P=0.006) and finasteride (P<0.001) alone.

CONCLUSIONS

Long-term combination therapy with doxazosin and finasteride was safe and reduced the risk of overall clinical progression of benign prostatic hyperplasia significantly more than did treatment with either drug alone. Combination therapy and finasteride alone reduced the long-term risk of acute urinary retention and the need for invasive therapy.

Efficacy of shunt surgery for refractory low flow priapism: a report on the incidence of failed detumescence and erectile dysfunction

PURPOSE

The reported success rate for surgical cavernosa-to-spongiosum shunts in patients with refractory low flow priapism is variable and yet it is reported to be as high as 100% in terms of achieving detumescence. The long-term potency rate after the introduction of the shunt procedure is also as high as 50%. We reviewed the efficacy of various shunts in terms of achieving detumescence and we clarified the rate of erectile dysfunction at long-term followup.

MATERIALS AND METHODS

Patients were included in the analysis if they had painful low flow priapism more than 4 hours in duration that was refractory to conservative management, ultimately requiring a surgical shunt. Data, including etiology, duration and initial treatment measures, were retrospectively compiled in the last 12 years and the type of surgical shunts performed were recorded. Followup erectile function was assessed by clinical notes and a telephone survey using the International Index of Erectile Function.

RESULTS

Of the 28 consecutive patients included in the study 13 (46.4%) required more than 1 operation for failed detumesence, of whom 12 (92.3%) initially underwent a Winter shunt. Only 2 of the 20 men (10%) with available followup reported preservation of pre-morbid erectile function. Three men (15%) achieved partial erection without the assistance of oral or injectable agents.

CONCLUSIONS

In contrast to previously reported success rates, approximately 50% of our patients required reoperation for failed detumescence following a cavernosa-to-spongiosum shunt. In our experience the Winter shunt was the least successful operation, whereas reoperation was uncommonly required following an Al-Ghorab or Quackels shunt. As many as 90% of our patients had erectile dysfunction at followup.

Measurement of thermal effects on the optical properties of prostate tissue at wavelengths of 1,064 and 633 nm

BACKGROUND AND OBJECTIVE

The extent of thermal injury during laser prostatectomy is dependent on the light distribution in laser-irradiated tissue. As tissue is irradiated, the optical properties change as a function of temperature due to an alteration of molecular and cellular structure. The purpose of the present study was to determine how the exposure of both fresh and previously frozen canine prostate tissue to elevated temperatures affects the optical properties.

STUDY DESIGN/MATERIALS AND METHODS

Optical properties were measured by using a double integrating sphere spectrophotometer with an inverse adding-doubling algorithm. Measurements were made at two wavelengths (1,064 nm and 633 nm) on samples heated in a waterbath in 5 degree-10 degree increments for 10 min through a 50 degrees C temperature range.

RESULTS

Upon coagulation, the absorption coefficient of fresh tissue decreased from the baseline measurement for both wavelengths (0.027 +/- 0.003 to 0.019 +/- 0.002 for lambda = 1,064 nm; 0.073 +/- 0.007 to 0.061 +/- 0.006 for lambda = 633 nm). However, the scattering coefficient increased sharply from the baseline measurement following coagulation (3.06 +/- 0.26 to 6.05 +/- 0.29 for lambda = 1,064 nm; 4.89 +/- 0.23 to 7.22 +/- 0.30 for lambda = 633 nm). Thermal coagulation occurred during exposure to temperatures between 60 degrees C and 70 degrees C.

CONCLUSION

Data obtained in this study indicate that thermal coagulation of tissue alters the optical properties. The extent to which these changes occur was found to be dependent on wavelength and freshness of tissue. These results are significant because they suggest how thermally induced changes in the optical properties may limit the depth of light penetration in tissue thus compromising treatment.

Sacral neuromodulation in the treatment of urgency-frequency symptoms: a multicenter study on efficacy and safety

PURPOSE

Neuromodulation of sacral nerves has shown promising results in correcting voiding dysfunction. We report the results of a multicenter trial designed to assess the efficacy of sacral nerve neuromodulation in patients presenting with refractory urinary urgency-frequency.

MATERIALS AND METHODS

A total of 51 patients from 12 centers underwent baseline assessment, including a detailed voiding diary, urodynamic evaluation and percutaneous test stimulation of the sacral nerves at S3 and/or S4. All patients enrolled in the study had undergone prior conventional treatment, such as pharmacotherapy, hydrodistention and surgical intervention, which failed. All patients demonstrated a satisfactory response to trial stimulation and were randomly divided into a stimulation group (25 patients) and a control group (26). A sacral nerve stimulation device was implanted after 6 months in the control group. Patients were followed at 1, 3 and 6 months, and at 6-month intervals for up to 2 years after implantation of a neuroprosthetic InterStim* system. dagger The study variables included the number of voids daily, volume voided per void and degree of urgency before void.

RESULTS

Compared to the control group, 6-month voiding diary results demonstrated statistically significant improvements (p <0.0001) in the stimulation group with respect to the number voids daily (16.9 +/- 9.7 to 9.3 +/- 5.1), volume per void (118 +/- 74 to 226 +/- 124 ml.) and degree of urgency (rank 2.2 +/- 0.6 to 1.6 +/- 0.9). Patients in the control group showed no significant changes in voiding parameters at 6 months. Significant improvements in favor of the stimulation group were noted in various parameters with respect to water cystometry and quality of life (SF-36). At 6 months after implant, neurostimulators were turned off in the stimulation group and urinary symptoms returned to baseline values. After reactivation of stimulation sustained efficacy was documented at 12 and 24 months.

CONCLUSIONS

Neuromodulation of the sacral nerves is an effective, safe therapy that successfully treats significant symptoms of refractory urgency-frequency.

Evaluation of renal resistive index, maximum velocity, and mean arterial flow velocity in a hydronephrotic partially obstructed pig model

RATIONALE AND OBJECTIVES

The authors investigate, in a controlled pig model, the usefulness of Doppler sonographic measurements of resistive index (RI), maximum velocity (Vmax), and mean velocity (Vmean) in diagnostic evaluation of the partially obstructed kidney.

METHODS

Seven female pigs underwent surgical partial unilateral renal obstruction at the ureteropelvic junction. Doppler parameters of RI, Vmax, and Vmean were measured preoperatively and postoperatively in obstructed and contralateral nonobstructed kidneys. The General Linear Model multivariate analysis of variance was used for statistical analysis of data.

RESULTS

There was no significant difference in the preoperative control values of RI (P = 0.71), Vmax (P = 0.27), and Vmean (P = 0.12). There was a statistically significant decrease in the Vmax and Vmean after postoperative day 5 in the obstructed kidney compared with the contralateral nonobstructed kidney (P = 0.01 and 0.03, respectively). There was no statistically significant difference in RI during the study.

CONCLUSIONS

In this study, RI was not a reliable indicator of partial renal obstruction. Measurements of maximal and mean blood flow velocities reached discriminatory significance only after the fifth postobstructive day, proving insensitive in the immediate postobstructive period. Vmax and Vmean demonstrated a decrease in the partially obstructed renal collecting system after 5 days of obstruction and may serve as useful parameters in the evaluation of obstruction after the immediate acute period, when compared with a nonobstructed contralateral system.

Techniques of coagulation laser prostatectomy for narrow divergence angle fibers

Although laser prostatectomy has become an accepted technique for the treatment of obstructive prostatism, considerable debate remains about which laser prostatectomy method to use in various treatment situations. This article discusses the different methods of noncontact side-firing coagulation laser prostatectomy using narrow divergence angle fibers (< 30 degrees). Static treatment strategies that have been successfully employed with widely divergent beams are not appropriate for fibers producing narrow divergence angle beams. Narrow divergence angle beams produce a small diameter spot on the prostatic urethra and far larger power density. Additionally, neodymium/yttrium aluminum garnet light scatters relatively poorly within prostatic tissue. Most light continues along the path of through transmission until ultimate tissue absorption and conversion into heat. The width and total volume of the coagulated lesion is therefore limited when using a narrow divergence angle fiber to produce static lesions. Probe movement is essential. Rapid (> 2 mm/s) probe movement produces only superficial coagulation. An initial dwell period of approximately 3 s is also important to maximize coagulated tissue volume. Scanning strategies where the fiber is moved through the prostatic urethra in longitudinal and radial directions are discussed and compared. Radial and longitudinal scanning methods produce similar coagulation defects. Treatment using a rocking motion within a limited volume of tissue may increase coagulation depth. No technique is ideal for all clinical situations. Vaporization prostatectomy or contact laser transurethral incision of the prostate is appropriate for primary treatment of glands < 30 g or as adjunctive therapy to facilitate early catheter removal. Alternative treatment methods are compared to noncontact coagulation prostatectomy.

Evaluation and management of the urologic consequences of neurologic disease

Neurologic disorders create important functional urinary tract abnormalities. Loss of bladder reflex inhibition and coordination due to neurologic disease or injury to higher centers may lead to morbidity such as recurrent urinary tract infection, hydronephrosis, urinary tract stones and loss of renal function. This paper discusses neurogenic bladder disease using a descriptive urodynamic format. The importance of detrusor hyperreflexia and internal and external sphincter dyssynergia are discussed in detail. Finally, a practical clinical management plan is discussed for patients with urologic dysfunction due to cerebrovascular accident, Parkinson's disease, multiple sclerosis, spinal cord injury, and peripheral neuropathy.

Prevention and treatment of incontinence after radical prostatectomy

Postoperative complications after radical prostatectomy have only recently been studied in a formal prospective manner. A survey of existing literature yields widely disparate rates of postoperative incontinence. Classically, about 5% of patients were believed to be incontinent. More recent studies that involve patient questionnaires and a specific continence history indicate that nearly 30% of patients experience some urinary leakage with activity. Evolving new operative techniques such as modified apical dissection and construction of a tubularized neourethra have potential to improve continence rates considerably. Patients who do experience urinary incontinence should be offered appropriate evaluation and treatment. In addition to cystourethroscopy, all patients should undergo cystometry and Valsalva leak-point testing to differentiate sphincteric dysfunction from detrusor instability. Injection of bovine cross-linked collagen into the preexternal sphincter zone or implantation of the artificial urinary sphincter are options for treatment of intrinsic sphincter dysfunction. Detrusor instability is best treated with pharmacotherapy. This article discusses the details of prevention, evaluation, and treatment of postprostatectomy incontinence.

Laser prostatectomy devices and their tissue effects

Laser systems used for prostatectomy may be right-angle (sidefiring) devices, which are either refractive or reflective, or contact devices. The tissue physics of these systems differ, and as a result, there are very real differences in the optimal exposure techniques. An understanding of the device being used is essential for producing a satisfactory result.

Intrapelvic pressure monitoring in the partially obstructed porcine kidney

OBJECTIVES

The diagnosis of urinary obstruction in newborns and infants remains difficult because the diagnostic studies available at present are fraught with many problems. It is our premise that precise measurement of renal pelvic pressures under physiologic conditions in patients with urinary tract dilation will allow diagnosis of obstruction and prediction of further renal damage. This study evaluates an intrapelvic pressure monitoring system.

METHODS

Four porcine subjects had partial ureteropelvic junction obstruction created surgically; two subjects were used as controls. Doppler ultrasound and MAG-3 furosemide renography were performed preoperatively and each week pressures were measured with a Millar 5 F solid-state pressure transducer and the analog signals were converted on line to digital information to allow signal processing and later data analysis. Antegrade nephrostograms were obtained at the same sitting and showed that the model remained stable over time. Measurements were obtained at physiologic flow rates as well as at the standard Whitaker infusion rate of 10 cc/min.

RESULTS

Thirteen pressure studies were performed on 9 kidneys. Each study was classified as normal (4), partial obstruction (8), or total obstruction (1), based on ultrasound and nephrostogram criteria. The normal units had baseline pressures of 4.12 +/- 0.94 cm water (H2O), which increased to 9.12 +/- 1.38 cm H2O with infusion. In the partially obstructed group, baseline was 16.4 +/- 3.83 cm H2O and increased to 35.3 +/- 15.9 cm H2O with infusion. The kidney with total obstruction showed a baseline pressure of 27 cm H2O, which increased to 68 cm H2O with infusion. These pressure measurements were also compared to furosemide renography.

CONCLUSIONS

Intrapelvic pressures correlated well with conventional ultrasound and nephrostogram in the evaluation of partial obstruction. However, the results of furosemide renography and the Whitaker test were quite variable and did not accurately define partial obstruction or correlate with intrapelvic pressure. The Millar solid-state transducer monitoring system is an accurate method of evaluating the intrapelvic pressure and could possibly become a standard for diagnosing significant urinary obstruction against which other studies can be evaluated.

Urological manifestations of sacrococcygeal teratoma

A review was done of 29 patients diagnosed with sacrococcygeal teratoma between 1978 and 1991. Urological disorders included total urinary retention (6 patients), hydronephrosis (6), hydrocele (4) and undescended testis (1). Ultrasonography and voiding cystourethrography were performed on the 6 patients in total urinary retention. These studies revealed cystic retrorectal lesions frequently with intralesional calcifications, and anterior and superior displacement of the bladder. Bladder wall trabeculation occurred in 2 of these 6 patients, and 4 had moderate or severe hydronephrosis. Upper urinary tract dilatation was found in 2 patients not in total retention. Hydronephrosis appeared to be related to poor bladder emptying and presumably high intravesical pressures, since each case resolved spontaneously after tumor resection. No primary upper tract anomalies were identified.

Calcium-accentuated ischemic damage during reperfusion: the time course of the reperfusion injury in the isolated working rat heart model

The purpose of this study was to determine the time course of calcium-induced postischemic reperfusion injury to the myocardium, using an initial short-term calcium-enriched reperfusion solution. The isolated rat heart model was subjected to 30 min of normothermic potassium cardioplegia-induced ischemic arrest. Control hearts received normal calcium Krebs-Henseliet buffer (KHB) reperfusion. Experimental hearts were challenged with 10 min of calcium-enriched (KHB) reperfusion starting at 0, 1, 2, 5, 15, and 30 min after the beginning of reperfusion. Aortic flow recovery 60 min after reperfusion was used to determine functional recovery. Control hearts recovered 82 +/- 3% of preischemic aortic flow. Hearts which received calcium challenge at 0 and 1 min after the start of reperfusion recovered 43 +/- 4 and 69 +/- 3% of preischemic aortic flow, respectively (P less than 0.01 and P less than 0.05, respectively). Hearts which received calcium challenge 2, 5, 15, and 30 min after reperfusion recovered 75 +/- 2, 80 +/- 2, 85 +/- 2, and 83 +/- 2% of preischemic aortic flow, respectively. Our results indicate that the postischemic myocardium is very susceptible to calcium-accentuated ischemic damage during the initial period of reperfusion. The postischemic heart, however, quickly recovers its ability to withstand a calcium challenge. Five minutes after the start of reperfusion the heart is not influenced by calcium challenge.

Terminal magnesium cardioplegia: protective effect in the isolated rat heart model using calcium accentuated ischemic damage

We have developed a modified isolated working rat heart model to study the effect of potassium and magnesium cardioplegia given just prior to reperfusion, "terminal cardioplegia," on preservation of aortic flow following a standard ischemic insult. The model incorporates a short-term calcium challenge at the beginning of reperfusion to accentuate ischemic injury. All hearts were given initial potassium cardioplegia and subjected to 30 min of normothermic ischemia. Terminal cardioplegia was given for the 2 min prior to reperfusion. Calcium-challenged hearts were reperfused initially with calcium-enriched reperfusate and then switched to standard reperfusate. Aortic flow prior to and 60 min after ischemia was used to determine functional protection. Hearts recovered 82 +/- 3% of preischemic aortic flow when reperfused with normocalcemic reperfusate. When the initial reperfusate was enriched with calcium, aortic flow was only 43 +/- 4% of control. Hearts given terminal magnesium cardioplegia and then challenged with calcium-enriched reperfusate recovered 79 +/- 4% of control aortic flow. Hearts given terminal potassium cardioplegia recovered only 53 +/- 5% of control aortic flow when challenged with calcium-enriched initial reperfusate. Our results indicate that the recovery of aortic flow is significantly reduced by short-term postischemic calcium challenge. This damage is blocked by terminal magnesium cardioplegia, but not by terminal potassium cardioplegia.

Disposition of the aromatic amine, benzidine, in the rat: characterization of mutagenic urinary and biliary metabolites

The mutagenic and carcinogenic aromatic amine, benzidine (BZ), underwent extensive biotransformation in the rat. Three days after po (5.0 mg/kg) or iv (2.5 mg/kg administration of [14C]BZ, 90% of the radiolabel had been excreted in the urine (25%) and feces (65%); 7% was recovered in the animal. As the dose was increased from 0.5 to 50 mg/kg, the percentage of the dose excreted in urine increased twofold. In distribution studies, a major portion of the iv dose accumulated in the intestinal tract due to the excretion of 71% of the administered radiolabel in bile. The liver, which is a primary target organ of BZ carcinogenicity in rats, contained a higher concentration of radiolabel than other tissues studied. A minimum of 17 urinary and/or biliary metabolites were separated by HPLC. The major metabolites were N-acetyl-BZ(ABZ), N,N'-diacetyl-BZ(DABZ), BZ-N-glucuronide, ABZ-glucuronide, N-OH-DABZ glucuronide, 3-OH-DABZ glucuronide, and a glutathione conjugate of DABZ (3-GSH-DABZ). At low doses (0.5 to 5 mg/kg), 3-OH-DABZ glucuronide, 3-GSH-DABZ, and DABZ were the major urinary or biliary metabolites. However, at higher doses (50 mg/kg), N-OH-DABZ glucuronide, which was a minor metabolite at low doses, became a major urinary and biliary metabolite. Several urinary and biliary metabolites displayed significant mutagenicity in the Salmonella typhimurium (strain TA98)-liver S9-beta-glucuronidase assay. However, N-OH-DABZ glucuronide exhibited a mutagenic potency 10X greater than the other urinary metabolites. Results of these studies demonstrate that BZ is rapidly metabolized via N-acetylation, N-hydroxylation, and aromatic hydroxylation to a variety of mutagenic metabolites which are excreted in urine or bile primarily as glucuronide and/or glutathione conjugates. The most potent mutagen studied was also a major urinary and biliary metabolite.

Metabolism, distribution, and excretion of the carcinogenic aromatic amine, 3,3'-dimethoxybenzidine in the rat. Formation of mutagenic urinary and biliary metabolites

The carcinogenic aromatic amine 3,3'-dimethoxybenzidine (DMOB) was rapidly metabolized in the rat. Thirty minutes after iv administration of 14C-DMOB, less than 2% of the dose could be recovered from the animal as the parent compound. Extensive biliary excretion (70% of the dose) resulted in the accumulation of approximately 50% of the dose in the intestinal tract. Three days after either oral or iv dosing, 50% of the administered radiolabel had been excreted in the feces and 30-40% excreted in the urine while 45% of the radiolabel remaining in the animal was present in the liver in the form of covalently bound metabolites. GC/MS studies of urine and bile demonstrated the presence of eight previously unidentified metabolites formed via N-acetylation, hydroxylation, O-demethylation, and glucuronidation. DMOB was mutagenic to Salmonella typhimurium strain TA98 only after metabolic activation by liver enzymes. N-Acetyl-DMOB was a more potent bacterial mutagen than either DMOB, N,N'-diacetyl-DMOB, or other biliary metabolites.

Autosomal recessive eye and brain anomalies: Warburg syndrome

Two siblings are reported who appear to have an autosomal recessive disorder of eye and central nervous system anomalies. The findings in fourteen previously described and similarly affected patients are summarized. Ocular anomalies include microphthalmos, megalocornea, the Peter anomaly, cataract, coloboma, persistent hyperplastic primary vitreous, and retinal detachment with retinal dysplasia. Central nervous system malformations include agyria-pachygyria, cerebellar dysplasia, encephalocele, Dandy-Walker cyst, and hydrocephalus. We suggest that this disorder be known as Warburg syndrome.

Metabolism of the human carcinogen, benzidine, in the isolated perfused rat liver

14C-Benzidine (BZ) was added to the recirculating perfusate of the isolated perfused rat liver. The system was monitored at timed intervals for the disappearance of BZ and the appearance of metabolites. BZ was extensively metabolized by this system and after 2 hr of perfusion greater than 95% of the administered radiolabel was in the form of metabolic products. In the perfusate the concentration of BZ declined rapidly whereas the concentration of N-acetyl-BZ (ABZ) increased temporarily and then declined. The concentration of N,N'-diacetyl-BZ (DABZ) increased with time and by 1 hr DABZ had become the major metabolite in the system. In the bile, which contained 22% of the dose after 2 hr, BZ-N-glucuronide and ABZ-glucuronide were the major metabolites initially, but after 1 hr of perfusion N-hydroxy-DABZ-glucuronide had become the major biliary metabolite. Addition of BZ and 35S-Na2SO4 to the perfusate resulted in at least one 35S-containing metabolite. Other major metabolites excreted in bile included 3-hydroxy-DABZ glucuronide, ABZ, and DABZ. DABZ underwent deacetylation to ABZ and N-hydroxy-DABZ underwent rapid reduction to DABZ when added to the isolated liver system. Qualitatively similar biliary metabolite patterns at later times were observed when either BZ, DABZ, or N-hydroxy-DABZ was added to the perfusate.