Risk factors for artificial urinary sphincter failure

PURPOSE

To analyze revision rates and risk factors for artificial urinary sphincter failure.

METHODS

Eighty-four patients underwent implantation of an artificial urinary sphincter in one reference center. Continence rates were defined by daily pad usage. Influence of predefined risk factors for device explantation, revision, differences in preoperative pad usage, and device survival was analyzed using Chi-squared test, Wilcoxon signed-rank test, and Kaplan-Meier analysis. A multivariate analysis was performed using a logistic regression model. A p value below 0.05 was considered statistically significant.

RESULTS

After a mean follow-up of 39.7 months, the device was still in situ in 64 patients. In univariate analysis, perioperative need of anticoagulation led to a significant increase in urethral erosion (6 vs. 30 %; p = 0.002) and explantation rate (15 vs. 34 %; p = 0.047). Pelvic irradiation increased postoperative infection rates significantly (0 vs. 10 %; p = 0.018). Penoscrotal approach led to significant increase in urethral erosion rate (0 vs. 21 %; p = 0.015). Implantation of a double cuff led to a significant increase in explantation rate (58 vs. 24 %; p = 0.014), revision rate (75 vs. 38 %; p = 0.017), and infection rate (17 vs. 1 %; p = 0.008). When using cuff size of 3.5 cm, revision rate (20 vs. 50 %; p = 0.026) as well as incontinence rates (40 vs. 82 %; p = 0.014) was significantly lower. In multivariate analysis, only perioperative anticoagulation and double-cuff placement were independent predictors of artificial urinary sphincter failure.

CONCLUSIONS

Our findings highlight the influence of perioperative anticoagulative therapy. In addition, the current study provides further evidence that double-cuff implantation should be performed only with caution during primary implantation.

[Prevalence and incidence of dementia among nursing home residents and residents in homes for the aged in comparison to private homes]

Based on a representative epidemiological study on dementia, prevalence and incidence rates of institutionalized individuals aged 75 years and older in comparison to those living in private homes are presented. The study was conducted between 1997 and 1999. Core component assessing cognitive function was the SIDAM (Structured Interview for the diagnosis of Dementia of the Alzheimer type, Multi-infarct dementia and dementias of other etiology according to ICD-10 and DSM-III-R, DSM-IV). If cognitive testing with study participants was not possible (e.g., due to fragility, death before examination) proxy interviews were performed with relatives or staff using the CDR (Clinical Dementia Rating). Prevalence and incidence rates in institutions were four times higher than in private homes. A prevalence rate of dementia for institutionalized individuals 75+ according to DSM-III-R of 47.6% was found; the annual incidence rate was 17.2%. This high proportion of people with dementia in institutions requires the development of new concepts of care to meet the demands of this changing situation in residential and nursing homes.

Prevention of neointimal proliferation by immunosuppression in synthetic vascular grafts

OBJECTIVE

Immunosuppressive agents have been proposed to reduce neointimal hyperplasia in synthetic vascular grafts. Thus, the purpose of the present study was to evaluate the safety and efficacy of rapamycins (systemic vs. local vs. oral administration) and mycophenolate mofetil (MMF) to reduce intimal hyperplasia in infrarenal synthetic vascular grafts of the rat.

METHODS

Fifty-four Wistar rats (250 g) completed the study after a synthetic vascular graft (ePTFE, Gore-tex, 2 mm diameter, 10 mm length) was implanted end-to-end in the infrarenal aorta. The animals were divided into three groups: group 1 consisted of 12 control animals, group 2 consisted of 37 rats receiving rapamycins, either per os (RAD, 1.5 or 3 mg/kg), intraperitoneally (RPM, 1.5 or 3 mg/kg) or locally (RPM soaking of the graft); and in group 3 (n=5), MMF (40 mg/kg) was administered orally. The animals were followed weekly with weight controls and signs of toxicity for 30 (n=37) and 60 (n=17) days, respectively. All animals were sacrificed and underwent histological examination at completion of the study.

RESULTS

All animals survived in groups 1 and 3, but five died in group 2. The weight gain was normal in all groups, except for the subgroup 2a receiving high dose rapamycins orally. All rats in group 3 suffered from diarrhea, whereas animals receiving high dose rapamycins showed toxic signs (hair loss, wound healing problems). Histological examination showed a significant increase in intimal hyperplasia in group 1 (0.03+/-0.01 and 0.14+/-0.05 microm after 30 and 60 days, respectively; P<0.01). Rapamycins in either application or dosage had no significant effect on intimal hyperplasia.

CONCLUSIONS

Local or systemic administration of rapamycins has no effect on intimal hyperplasia in synthetic vascular grafts. In contrast, toxic signs with weight loss were observed in animals treated with high dose rapamycins, but not in those treated with MMF. Thus, in the rat model, immunosuppression with rapamycins or MMF cannot be recommended for the prevention of intimal hyperplasia in the synthetic vascular graft model.