Bacterial Interactions as Detected by Pooled Antibiotic Susceptibility Testing (P-AST) in Polymicrobial Urine Specimens.

Introduction: Antimicrobial susceptibility is well characterized in monomicrobial infections, but bacterial species often coexist with other bacterial species. Antimicrobial susceptibility is often tested against single bacterial isolates; this approach ignores interactions between cohabiting bacteria that could impact susceptibility. Here, we use Pooled Antibiotic Susceptibility Testing to compare antimicrobial susceptibility patterns exhibited by polymicrobial and monomicrobial urine specimens obtained from patients with urinary tract infection symptoms. Methods: Urine samples were collected from patients who had symptoms consistent with a urinary tract infection. Multiplex polymerase chain reaction testing was performed to identify and quantify 31 bacterial species. Antibiotic susceptibility was determined using a novel Pooled Antibiotic Susceptibility Testing method. Antibiotic resistance rates in polymicrobial specimens were compared with those in monomicrobial infections. Using a logistic model, resistance rates were estimated when specific bacterial species were present. To assess interactions between pairs of bacteria, the predicted resistance rates were compared when a pair of bacterial species were present versus when just one bacterial species was present. Results: Urine specimens were collected from 3,124 patients with symptoms of urinary tract infection. Of these, multiplex polymerase chain reaction testing detected bacteria in 61.1% (1910) of specimens. Pooled Antibiotic Susceptibility Testing results were available for 70.8% (1352) of these positive specimens. Of these positive specimens, 43.9% (594) were monomicrobial, while 56.1% (758) were polymicrobial. The odds of resistance to ampicillin (p = 0.005), amoxicillin/clavulanate (p = 0.008), five different cephalosporins, vancomycin (p = <0.0001), and tetracycline (p = 0.010) increased with each additional species present in a polymicrobial specimen. In contrast, the odds of resistance to piperacillin/tazobactam decreased by 75% for each additional species present (95% CI 0.61, 0.94, p = 0.010). For one or more antibiotics tested, thirteen pairs of bacterial species exhibited statistically significant interactions compared with the expected resistance rate obtained with the Highest Single Agent Principle and Union Principle. Conclusion: Bacterial interactions in polymicrobial specimens can result in antimicrobial susceptibility patterns that are not detected when bacterial isolates are tested by themselves. Optimizing an effective treatment regimen for patients with polymicrobial infections may depend on accurate identification of the constituent species, as well as results obtained by Pooled Antibiotic Susceptibility Testing.

Renal deterioration in multiple sclerosis patients with neurovesical dysfunction.

OBJECTIVES: Our aims were to determine the prevalence of renal ultrasound (RUS) abnormalities over time in multiple sclerosis (MS) patients with lower urinary tract symptoms (LUTS). METHODS: Data were examined retrospectively from MS patients with LUTS, from 2000-2009. Study inclusion requirements were both baseline urodynamics (UD) and RUS data, with followup RUS at ≥ 12 months. Age, time since diagnosis (TSD), MS subtype and the UD/RUS results were evaluated for associations. RESULTS: At presentation, 173 subjects underwent UD and RUS, but only 89 had a repeat RUS at ≥ 12 months. Median followup was 61 months. Initial RUS abnormalities were found in 10 (5.8%) subjects. At followup, upper urinary tract (UUT) abnormalities were seen in 11 (12.4%) subjects. Patients > 49 years old were more likely to have an abnormality (OR 0.181, 95% CI 0.037-0.892, p = 0.04). Patients with abnormal compliance were also more likely to have an abnormal followup RUS (OR 0.185, 95% CI 0.037-0.924, p = 0.04). No other demographic or UD factor was associated with RUS abnormalities. CONCLUSIONS: The development of structural UUT changes is low in MS patients. Urodynamic studies are useful for LUTS treatment strategies in complicated patients, but UD does not appear to have much impact with regard to upper tract changes.

Urethral distortion after placement of synthetic mid urethral sling.

PURPOSE: We retrospectively compared preoperative characteristics in patients with new onset lower urinary tract symptoms after receiving a mid urethral sling who did (group 1) and did not (group 2) have radiographically confirmed urethral distortion during voiding. MATERIALS AND METHODS: After receiving institutional review board approval we reviewed the charts of patients who underwent mid urethral sling excision for new onset lower urinary tract symptoms between January 2003 and July 2009. We collected demographic and questionnaire data, including the Urogenital Distress Inventory, Incontinence Impact Questionnaire and visual analog scale (score 0 to 10) for quality of life, and preoperative urodynamics data, including maximum flow, detrusor pressure at maximum flow and post-void residual urine. Lateral voiding cystourethrogram was done with the patient standing. RESULTS: Of 87 operable patients 23 were excluded from analysis due to lack of a voiding cystourethrogram (16) or of the voiding phase on voiding cystourethrogram (7). Groups 1 and 2 consisted of 51 and 13 patients, respectively. Age, time to sling excision, and Urogenital Distress Inventory, Incontinence Impact Questionnaire and quality of life scores were not significantly different between the groups. Preoperative urodynamic parameters in 37 group 1 and 7 group 2 patients revealed a mean detrusor pressure at maximum flow of 31.1 and 22.2 cm H(2)O, respectively (p = 0.25). Mean preoperative maximum flow was 13.4 and 15.4 ml per second (p = 0.59), and median post-void residual urine was 45.5 and 8.3, ml respectively (p = 0.16). CONCLUSIONS: Despite similar baseline symptoms and uroflow characteristics patients with urethral distortion had 50% higher detrusor pressure and greater post-void residual urine than those without urethral distortion. Flow rate alone may be insufficient to predict the impact of the mid urethral sling on bladder function in patients with new onset lower urinary tract symptoms.

Is obesity a risk factor for failure and complications after surgery for incontinence and prolapse in women?

PURPOSE: Obese women (body mass index 30 kg/m2 or greater) are considered to be at risk for postoperative complications and failure after stress incontinence surgery. We compare the outcomes in this population with nonobese women (body mass index less than 30 kg/m2) undergoing rectus fascia, porcine dermis and polypropylene sling procedures. MATERIALS AND METHODS: We retrospectively identified 412 women with a body mass index less than 30 kg/m2 (94 autologous rectus fascia, 157 acellular porcine dermis, 161 transobturator polypropylene mid urethral sling) and 297 with a body mass index of 30 kg/m2 or greater (66 autologous rectus fascia, 114 acellular porcine dermis, 117 transobturator polypropylene mid urethral sling) who underwent sling procedures and other pelvic surgery. Evaluation included SEAPI assessment and quality of life questionnaires. Global cure equaled subjective SEAPI composite=0 and subjective satisfaction. Stress urinary incontinence cure equaled SEAPI (S)=0 and negative cough stress test. Chart review for perioperative data was conducted. Groups and outcomes were statistically compared. RESULTS: All women had a minimum followup of 12 months. After controlling for body mass index preoperative demographics, SEAPI scores and quality of life indices were not statistically different within each sling group. Global cure and stress urinary incontinence cure rates were significantly higher for nonobese women in each sling group. Statistically significant improvement in SEAPI scores and quality of life indices was achieved for all groups, and there were no statistical differences within each sling group. Overall obese women had no increase in complications compared with nonobese women. The incidence of obstructive sequelae was statistically higher in nonobese women undergoing autologous rectus fascia and transobturator polypropylene mid urethral sling procedures. CONCLUSIONS: Although cure rates are lower, obese women have significant improvements in quality of life after surgery for stress urinary incontinence. Obesity does not appear to be a risk factor for additional complications during sling and prolapse surgery.

Mesh kits for anterior vaginal prolapse are not cost effective.

INTRODUCTION AND HYPOTHESIS: To analyze the cost-effectiveness of traditional anterior colporrhaphy (AC), hand-cut mesh, and mesh kit anterior vaginal prolapse (AVP) repair. METHODS: A decision analysis model was built using mean operating room (OR) times, mesh extrusion rates, and recurrence rates obtained from a meta-analysis along with Medicare reimbursement for surgeon fees and office visits, and hospital costs of supplies, OR time, and room and board. RESULTS: Non-kit mesh repair was $3,380, AC $3,461, and mesh kit $4,678. One-way sensitivity analyses demonstrated recurrence rate of AC would need to be 28% to be equally cost effective. Mesh kit repair did not reach cost equivalence even at 0 min OR time. Two-way sensitivity analysis comparing mesh extrusion and AC recurrence demonstrated AC is more cost effective if recurrence is <20% or extrusion >25%. CONCLUSIONS: Mesh kits for AVP repair are not cost effective, regardless of the OR time saved.

Demographic and urodynamic factors associated with persistent OAB after anterior compartment prolapse repair.

INTRODUCTION: Overactive bladder (OAB) symptoms often accompany pelvic organ prolapse. While there seems to be a relationship between symptom resolution and anatomic repair, a subset of patients will not experience improvement in OAB symptoms. Our aim was to identify preoperative demographic and urodynamic (UD) parameters related to persistence of OAB symptoms after anterior vaginal prolapse (AVP) repair. METHODS: This retrospective cohort study examined demographic and UD data from patients undergoing AVP surgery. Pre- and post-operative Urogenital Distress Inventory (UDI-6) scores for frequency, urge urinary incontinence (UUI), and difficulty voiding were analyzed, as were correlations between scores and pre-operative UD data. RESULTS: From 2002 to 2008, 88 patients underwent AVP repair and were included in the final analysis. Surgery resulted in a reduction of frequency (33%), UUI (49%), and difficulty voiding (74%) at median 21 months follow-up. Change in symptom scores was unrelated to age, parity, BMI, or AVP grade, although older women reported greater improvement in difficulty emptying after repair. Improvement in difficulty emptying was related to a larger pre-operative post-void residual (PVR) (129 ml vs. 31 ml, P = 0.0008). Persistent UUI after repair was significantly related to a higher preoperative P(det)Q(max) (OR 1.056, 95% CI 1.003-1.11, P = 0.04). Other pre-operative UDS variables were not significantly related to the persistence of OAB symptoms. CONCLUSIONS: AVP repair reduces lower urinary tract symptoms (LUTS); however, 67% and 51% of patients will report persistent frequency and UUI, respectively, post-operatively. In this cohort, persistent OAB symptoms were not related to age, parity, BMI, or prolapse grade, but rather to pre-operative P(det)Q(max).

Incidence and management of vaginal extrusion of acellular porcine dermis after incontinence and prolapse surgery.

We report our experience with vaginal extrusion of acellular porcine dermis in women undergoing pelvic reconstructive surgery. Over 5 years, 270 patients received a Pelvicol pubovaginal sling (PVS) or prolapse repair using interposition graft. Charts were retrospectively evaluated for evidence of graft extrusion, management, and outcomes. Chi-square analysis was conducted to evaluate the association of extrusion with perioperative variables. Nineteen women (7%) had partial or complete vaginal graft extrusion. After a PVS, 11 of 13 women healed by re-epithelialization and remained continent, while 2 required operative debridement. Four of six patients receiving interposition grafts healed after small incisional separations. Two women underwent additional surgery to address extensive extrusion, and both prolapses recurred. After statistical analysis, vaginal extrusion was significantly associated with PVS and concomitant urethral diverticulectomy. Small incisional separations frequently heal and cause no symptom recurrence. Larger areas of extrusion may require debridement and may contribute to recurrence of symptoms.