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Ischemic priapism is a urological emergency that has been associated with long-standing and irreversible adverse effects on erectile function. Studies have demonstrated a linear relationship between the duration of critically ischemic episodes and the subsequent development of corporal fibrosis and irreversible erectile function loss. Placement of a penile prosthesis is a well-established therapeutic option for the management of erectile dysfunction secondary to ischemic priapism, and will be the focus of this review. Review of the current literature demonstrates a growing utilization of penile prostheses in the treatment of erectile dysfunction secondary to ischemic priapism. Unfortunately, there is a paucity of randomized-controlled trials describing the use of prosthesis in ischemic priapism. As a result, there is a lack of consensus regarding the type of prosthesis (malleable vs. inflatable), timing of surgery (acute vs. delayed), and anticipated complications for each approach. Both types of prostheses yielded comparable complication rates, but the inflatable penile prosthesis have higher satisfaction rates. Acute treatment of priapism was associated with increased risk of prosthetic infection, and could potentially cause psychological trauma, whereas delayed implantation was associated with greater corporal fibrosis, loss of penile length, and increased technical difficulty of implantation. The paucity of high-level evidence fuels the ongoing discussion of optimal use and timing of penile prosthesis implantation. Current guidance is based on consensus expert opinion derived from small, retrospective studies. Until more robust data is available, a patient-centered approach and joint decision-making between the patient and his urologist is recommended.

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Background Previous studies have documented improvement in erectile function after bilateral cavernous nerve injury (BCNI) in rats with the use of pioglitazone. Our group determined this improvement to be mediated by the insulin-like growth factor-1 (IGF-1) pathway. Aim To eliminate the systemic effects of pioglitazone and evaluate the local delivery of IGF-1 by polymeric microspheres after BCNI in the rat. Methods Male Sprague–Dawley rats aged 10–12 weeks were assigned at random to 3 groups: sham operation with phosphate buffered saline (PBS)-loaded microspheres (sham group), crush injury with PBS-loaded microspheres (crush group), and crush injury with IGF-1–loaded microspheres (IGF-1 group). Poly(lactic-co-glycolic) acid microspheres were injected underneath the major pelvic ganglion (MPG). IGF-1 was released at approximately 30 ng/mL/day per MPG per rat. Outcomes Functional results were demonstrated by maximal intracavernosal pressure (ICP) normalized to mean arterial pressure (MAP). Protein-level analysis data of IGF-1 receptor (IGF-1R), extracellular signal–regulated kinase (ERK)-1/2, and neuronal nitric oxide synthase (nNOS) were obtained using Western blot analysis and immunohistochemistry for both the cavernosal tissue and the MPG and cavernous nerve (CN). Results At 2 weeks after nerve injury, animals treated with IGF-1 demonstrated improved erectile functional recovery (ICP/MAP) at all voltages compared with BCNI (2.5V, P = .001; 5V, P < .001; 7.5V, P < .001). Western blot results revealed that up-regulation of the IGF-1R and ERK-1/2 in both the nervous and erectile tissue was associated with improved erectile function recovery. There were no significant between-group differences in nNOS protein levels in cavernosal tissue, but there was an up-regulation of nNOS in the MPG and CN. Immunohistochemistry confirmed these trends. Clinical Translation Local up-regulation of the IGF-1R in the neurovascular bed at the time of nerve injury may help men preserve erectile function after pelvic surgery, such as radical prostatectomy, eliminating the need for systemic therapy. Strengths & Limitations This study demonstrates that local drug delivery to the MPG and CN can affect the CN tissue downstream, but did not investigate the potential effects of up-regulation of the growth factor receptors on prostate cancer tissue. Conclusion Stimulating the IGF-1R at the level of the CN has the potential to mitigate erectile dysfunction in men after radical prostatectomy, but further research is needed to evaluate the safety of this growth factor in the setting of prostate cancer.

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