Background: Wound infection is a common complication in diabetic patients. The progressive spread of infections and development of drug-resistant strains underline the need for further insights into bacterial behavior in the host in order to develop new therapeutic strategies. The aim of our study was to develop a large animal model suitable for monitoring the development and effect of bacterial infections in diabetic wounds. Methods: Fourteen excisional wounds were created on the dorsum of diabetic and non-diabetic Yorkshire pigs and sealed with polyurethane chambers. Wounds were either inoculated with 2 × 10⁸ Colony-Forming Units (CFU) of Staphylococcus aureus or injected with 0.9% sterile saline. Blood glucose was monitored daily, and wound fluid was collected for bacterial quantification and measurement of glucose concentration. Tissue biopsies for microbiological and histological analysis were performed at days 4, 8, and 12. Wounds were assessed for reepithelialization and wound contraction. Results: Diabetic wounds showed a sustained significant infection (>10⁵ CFU/g tissue) compared to non-diabetic wounds (p < 0.05) over the whole time course of the experiment. S. aureus-inoculated diabetic wounds showed tissue infection with up to 8 × 10⁷ CFU/g wound tissue. Non-diabetic wounds showed high bacterial counts at day 4 followed by a decrease and no apparent infection at day 12. Epidermal healing in S. aureus-inoculated diabetic wounds showed a significant delay compared with non-inoculated diabetic wounds (59% versus 84%; p < 0.05) and were highly significant compared with healing in non-diabetic wounds (97%; p < 0.001). Conclusion: Diabetic wounds developed significantly more sustained infection than non-diabetic wounds. S. aureus inoculation leads to invasive infection and significant wound healing delay and promotes invasive co-infection with endogenous bacteria. This novel wound healing model provides the opportunity to closely assess infections during diabetic wound healing and to monitor the effect of therapeutical agents in vivo.

Diabetic wounds result in significant morbidity, prolonged hospitalization, and enormous health‐care expenses. Pigs have been shown to have wound healing resembling that in humans. The aim of this study was to develop a large‐animal model for diabetic wound healing. Diabetes was induced by streptozotocin injection in Yorkshire pigs. Full‐thickness wounds were created and dressed with a sealed chamber. Nondiabetic pigs with or without high glucose wound fluid concentration served as controls. Glucose concentration in serum and wound fluid was measured and collected. Wound contraction was monitored, and biopsies were obtained for measurement of reepithelialization. Wound fluid was analyzed for insulin‐like growth factor‐1 (IGF‐1), platelet‐derived growth factor, and transforming growth factor. Glucose concentration in wound fluid initially followed serum levels and then decreased to undetectable on day 9. Reepithelialization was significantly delayed in diabetic pigs. In nondiabetic pigs, wounds treated in a local hyperglycemic environment, and thus excluding the effects of systemic hyperglycemia, showed no difference in wound closure compared with controls. This suggests that delayed wound healing in diabetes is not induced by local high‐glucose concentration itself. Analysis of growth factor expression showed a marked reduction in IGF‐1 in the diabetic wounds. Diabetic pigs have impaired healing that is accompanied by a reduction of IGF‐1 in the healing wound and is not due to the local hyperglycemia condition itself.

We present data on long-term functional and cosmetic results after hypospadias surgery. Males older than 18 years with hypospadias treated in Sweden were asked to participate in the study, as well as age matched controls and circumcised men. All participants answered questionnaires, and a subgroup was examined during an outpatient visit. Relationships with outcome were analyzed using analysis of variance and regression analysis. A total of 167 patients with a mean age of 34 years and 169 controls with a mean age of 33 years answered the questionnaire. Of the patients 63% had distal, 24% mid and 13% proximal hypospadias. A total of 46 patients and 49 controls presented for physical examination. Patients were significantly less satisfied with the penile cosmetic outcome regarding all parameters of the Penile Perception Score. There was a difference in penile length between patients and controls (mean 9.7 vs 11.6 cm, p <0.001). More patients than controls reported voiding dysfunction symptoms (p = 0.003). Patients had a lower maximum urinary flow rate than controls (p = 0.001). These differences were most prominent between patients with proximal hypospadias and controls. Men operated on for hypospadias were less satisfied with the cosmetic result than controls, and had a shorter penile length. Patients presented with more symptoms of voiding dysfunction and displayed a lower maximum urinary flow rate. Patients with proximal hypospadias were more affected than those with milder hypospadias. Our results indicate that patients with hypospadias can be subgrouped and that those with severe phenotypes should be followed more closely during childhood as well as later in adulthood.

Randomized controlled trials (RCTs) are at the top of the pyramid of evidence as they offer the best answer on the efficacy of a new treatment. RCTs are true experiments in which participants are randomly allocated to receive a certain intervention (experimental group) or a different intervention (comparison group), or no treatment at all (control or placebo group). Randomization, along with other methodological features such as blinding and allocation concealment, safeguard against biases. This review will focus on parallel group RCT design as it is the most common design in the field of Pediatric Urology. RCTs can be designed using a superiority, equivalency, or non-inferiority hypothesis, and are usually preceded by a pilot, where the trial protocol is implemented in a small number of patients, mimicking the larger, definitive study. Even though regarded as the best available option to bring out scientific data, RCTs might be prone to mislead. If RCTs are small and underpowered, a difference of even one single event between groups, may completely change the trial results. To safeguard against RCTs weakness, a fragility concept of statistical significance was developed and called the Fragility Index (FI). RCTs may not be appropriate, ethical, or feasible for all surgical interventions. They may have limitations such as prohibitive cost and unrealistic large sample sizes. Nearly 60 % of surgical research questions cannot be answered by RCTs. Therefore, clinical practice should be based on the best available evidence on a given topic, regardless of the study design. However, even in these situations, conclusions drawn from observational studies must be interpreted with caution.