Underactive bladder has been described as a complex of symptoms related to detrusor weakness. The post-residual urine is a frequent problem of this condition, being necessary to solve it in order to prevent upper urinary tract damage as well as to avoid bladder overdistension. A safe option to promote bladder emptying has been the clean intermittent catheterization (CIC). Professional support to provide instructions on catheterization is important to achieve and to maintain the adherence to the treatment. However, an early withdrawal rate of about 20% has still been described (1). The major challenge of this treatment is to maintain regularity during catheterizations, avoiding discontinuation. The preferential use of hydrophilic catheters is still controversial (2) and studies involving non-neurogenic patients are still scarce.
The aim of the study was to compare complications, satisfaction, and performing rates between the use of standard and hydrophilic coated catheters in non-neurogenic patients submitted to long term bladder intermittent catheterization.

It was a controlled, prospective, “before and after” analysis study. Eligible patients for this study were older than 18 years with non-neurogenic underactive bladder. Patients were asked to answer the Underactive Bladder Questionnaire (UAB-q). They were invited to participate of the study if the score answered was ≥ 5, post-voiding residual urine > 150ml, and to be able to perform the CIC without previous experience. Patients submitted to surgical procedures in the lower urinary tract previously were excluded as well as any neurological condition or cognitive/mental impairment. Recruitment occurred in an outpatient clinic by the direct approach of the investigator. Initially, all patients were submitted to training for intermittent-self catheterization by the same nurse. In the first phase, all patients used 10-French Standard Polyvinyl Chloride (PVC) and gel lubricant (Xylocaine ® lubricant) for 45 days. They were evaluated after 15 and 45 days (visits 1 and 2 - Phase 1). After this period, the patients received the hydrophilic catheters (Speedicath® 10 Fr specific for gender) and were evaluated after 15 and 45 days of use (visits 3 and 4 - Phase 2). Visual Analogue Scale and the Assessment of user perception in bladder catheter use scale were used, respectively, to the patients show their pain level (Visits 1 to 4), and the perception of the catheter use by the patient (visits 2 and 4).
There was no previous estimation of the sample size because no epidemiological study about non-neurogenic underactive bladder patients that needs CIC have been described. This study was approved by the Institutional Ethics Committee (CAEE: 96211318.4.0000.5192) and all participants signed informed consent.
Sociodemographic and baseline clinical data were described by means and standard deviation or median. The Wilcoxon test was used to compare scores between the groups of standard catheter and hydrophilic coated catheter.  A level of 5% (p < 0.05) was considered statistically significant.

A total of 29 subjects with underactive bladder (UAB-q >5) were enrolled in the present study, 15 women and 14 men, with a mean age of 53 ± 13 (SD) and body mass index (BMI) of 28.3 ± 4.5 (SD). The sociodemographic and clinical data are described in table 1.
The incidence of complications is described in table 2. There was difference between standard and hydrophilic coated catheter in relation to the presence of symptomatic UTI in men, urethral bleeding, and pain. The incidence of asymptomatic bacteriuria was similar using both types of catheters. The overall perception reported by the participants about the hydrophilic coated catheter was significantly better for all the items.

The use of standard catheter is also associated to symptomatic UTI more frequently in neurogenic patients as described in previous study (3). However, the asymptomatic bacteriuria rate did not differ significantly between the catheters. Urethral bleeding occurred only with the use of standard catheter.  These results suggest that the systematic use of hydrophilic coated catheter might be relevant in prevention of urethral complications in long-term bladder management. Hydrophilic coated catheter was also associated with less discomfort and better perception and these aspects can be important in non-neurological patients with underactive bladder and preserved urethral sensitivity. Discomfort has been considered an important factor to the discontinuation of this procedure.
The impossibility of blinding the participants and clinicians about the type of catheter as well as the use of self-reported symptoms and limited sample size were potential weaknesses in this study.

The hydrophilic coated catheters may be considered more appropriate in non-neurogenic patients than standard catheters. However, further clinical and cost-effectiveness studies are necessary to standardize its use as first choice in long-term bladder management in patients with preserved sensitivity.

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