Factors Impacting Postoperative Opioid Use Among Patients Undergoing Implantation of Inflatable Penile Prosthesis.

BACKGROUND: While there is an increasing burden of chronic postoperative opioid use and opioid abuse in the United States, opioid use following inflatable penile prosthesis (IPP) surgery has not been well described. AIM: Describe postoperative opioid use following IPP surgery. METHODS: Seventy-four consecutive patients undergoing IPP implantation by a single surgeon were enrolled. Self-reported diaries tracked the type and amount of medication taken for 2 weeks following IPP surgery. High opioid consumers were defined as those consuming more than the median amount (10 mg) of opioids during the first 2 weeks postoperatively. Multivariate analyses were performed using stepwise backward elimination. OUTCOMES: Quantification of opioid use postoperatively and factors related to high opioid use. RESULTS: Fifty-six patients were included after 7 were excluded for preoperative opioid use and 11 were excluded for inability to contact. Median age was 67.5. Devices used were Boston Scientific (41, 73%) and Coloplast (15, 27%). All patients received local anesthetic. Most surgeries (44, 79%) were performed as outpatient. Preoperative analgesia with acetaminophen, celecoxib, and pregabalin was administered in 44 (78%), 44 (78%), and 28 (50%) of cases respectively; 32 (57%) of patients received 2 medications, 21 (36%) received three medications. In hospital median morphine equivalents was 7.5 (interquartile range [IQR] 0-7.5). Oxycodone prescribed at discharge was 50 mg (29, 52%), 75 mg (4; 7%), and 100 mg (23; 41%). Median milligrams of oxycodone used was 10 mg (IQR 0-23.5) at 7 days and 10 (IQR 0-37.5) at 14 days postdischarge. On univariate analysis, factors associated with an increased likelihood of high opioid use were morphine equivalents utilized in hospital (odds ratio [OR] 1.13, P < .05) and milligrams oxycodone prescribed at discharge (OR 1.05, P < .001) while patient demographics, procedure characteristics, and analgesic types were not found to be predictive of high opioid use. On multivariate analysis, milligrams oxycodone prescribed at discharge (OR 1.04, P < .005) were associated with an increased likelihood of high opioid use after discharge. CLINICAL IMPLICATIONS: Increased understanding of opioid use after IPP surgery may improve prescribing patterns after discharge. STRENGTHS & LIMITATIONS: This study quantified post discharge opioid use over the first 14 postoperative days. It is limited by single surgeon, small sample size, and retrospective design. CONCLUSION: Provider opioid prescribing patterns were associated with high opioid consumption postoperatively and a substantial amount of opioids prescribed at discharge remain unused by patients, suggesting that we can reduce or replace the amount of opioids that are prescribed. Ehlers ME, Mohan CS, Akerman JP, et al. Factors Impacting Postoperative Opioid Use Among Patients Undergoing Implantation of Inflatable Penile Prosthesis. J Sex Med 2021;18:1915-1920.

Systematic Review and Meta-Analysis of Cycling and Erectile Dysfunction.

INTRODUCTION: Conflicting evidence exists on the relationship between bicycle riding and erectile dysfunction (ED). A major limitation to several prior studies is the lack of a validated measure of ED. OBJECTIVE: To assess the relationship between cycling and clinically validated ED based on existing literature. METHODS: We searched several major databases from database inception through 2018 using a variety of search terms relating to "cycling" and "erectile dysfunction." Studies were included if they were written in English, reported original data, compared ED between cyclists and non-cycling controls, and used a validated measure of ED, such as the International Index of Erectile Function or the subset Sexual Health Inventory for Men (SHIM). Age, SHIM score, and comorbidities were extracted for all groups. Primary outcomes for each group were mean SHIM score and presence of ED (SHIM ≤ 21). A generalized linear mixed-effects model was used to fit the collected data for meta-analysis. Main outcome measures were unadjusted odds ratios of ED for cyclists and non-cyclists, mean SHIM score difference between cyclists and noncyclists, and both of these measures adjusted for age and comorbidities. RESULTS: After a systematic evaluation of 843 studies, 6 studies met our inclusion criteria, encompassing 3,330 cyclists and 1,524 non-cycling controls. When comparing cyclists to non-cyclists in an unadjusted analysis, there were no significant differences in the odds of having ED or mean SHIM score. However, when controlling for age and comorbidities, cyclists had significantly higher odds of having ED (odds ratio: 2.00; 95% confidence interval: 1.57, 2.55). CONCLUSIONS: Limited evidence supports a positive correlation between cycling and ED when adjusting for age and several comorbidities. Heterogeneity among studies suggests that further investigation into certain populations of cyclists that may be more vulnerable to ED may be beneficial. Gan ZS, Ehlers ME, Lin FC, et al. Systematic Review and Meta-Analysis of Cycling and Erectile Dysfunction. Sex Med 2021;9:304-311.

Preoperative Ultrasound-Guided Wire Localization of the Lateral Femoral Cutaneous Nerve.

BACKGROUND: Difficulty and sometimes inability to find the lateral femoral cutaneous nerve (LFCN) intraoperatively is well known. Variabilities in the course of the nerve are well documented in the literature. In a previous paper, we defined a tight fascial canal that completely surrounds the LFCN in the proximal thigh. These 2 factors sometimes render finding the nerve intraoperatively, to treat meralgia paresthetica, very challenging. OBJECTIVE: To explore the use of preoperative ultrasound to minimize operative time and eliminate situations in which the nerve is not found. METHODS: Since 2011, we have used preoperative ultrasound-guided wire localization (USWL) in 19 cases to facilitate finding the nerve intraoperatively. Data were collected prospectively with recording of the timing from skin incision to identifying the LFCN; this will be referred to as the skin-to-nerve time. RESULTS: In 2 cases, the localization was incorrect. In the 17 cases in which the LFCN was correctly localized, the skin-to-nerve time ranged from 3 min to 19 min. The mean was 8.5 min, and the median was 8 min. CONCLUSION: Preoperative USWL is a useful technique that minimizes the time needed to find the LFCN. For the less experienced surgeon, it is extremely valuable. For the experienced surgeon, it can identify anatomical abnormalities such as duplicate nerves, which may not be readily recognizable without ultrasound. Collaboration between the surgeon and the radiologist is very important, especially in the early cases.

Immunohistochemical assessment of rat nerve isografts and immunosuppressed allografts.

OBJECTIVE: Autologous peripheral nerve grafts are commonly used clinically as a treatment for peripheral nerve injuries. However, in research using an autologous graft is not always feasible due to loss of function, which in many cases is assessed to determine the efficacy of the peripheral nerve graft. In addition, using allografts for research require the use of an immunosuppressant, which creates unwanted side effects and another variable within the experiment that can affect regeneration. The objective of this study was to analyze graft rejection in peripheral nerve grafts and the effects of cyclosporine A (CSA) on axonal regeneration. METHODS: Peripheral nerve grafts in inbred Lewis rats were compared with Sprague-Dawley (SD) rats to assess graft rejection, CSA side effects, immune responses, and regenerative capability. Macrophages and CD8+ cells were labeled to determine graft rejection, and neurofilaments were labeled to determine axonal regeneration. RESULTS: SD rats without CSA had significantly more macrophages and CD8+ cells compared to Lewis autografts, Lewis isografts, and SD allografts treated with CSA. Lewis autografts, Lewis isografts, and SD autografts had significantly more regenerated axons than SD rat allografts. Moreover, allografts in immunosuppressed SD rats had significantly less axons than Lewis rat autograft and isografts. DISCUSSION: Autografts have long been the gold standard for treating major nerve injuries and these data suggest that even though CSA is effective at reducing graft rejection, axon regeneration is still superior in autografts versus immunosuppressed allografts.

Basic techniques for long distance axon tracing in the spinal cord.

The regeneration of axons after a spinal cord injury or disease is attracting a significant amount of interest among researchers. Being able to assess these axons in terms of morphology, length and origin is essential to our understanding of the regeneration process. Recently, two specific axon tracers have gained much recognition; biotinylated dextran amine (BDA) 10 kDa as an anterograde tracer and cholera toxin-B as a retrograde tracer. However, there are still several complexities when using these tracers, including the volume that should be administered and the best administration site so that a significant amount of axons are labeled in the area of interest. In this article, we describe some simple procedures for injecting the tracers and detecting them. We also quantified the number of axons at different locations of the spinal cord. Our results show axons labeled from motor cortex injections traveled down to the lumbosacral spinal cord in 2 weeks, while BDA injections into the lateral vestibular nucleus and reticular formation took 3 weeks to label axons in the lumbosacral spinal cord. Moreover, this protocol outlines some basic procedures that could be used in any laboratory and gives insight into the number of axons labeled and how procedures could be tailored to meet specific researcher's needs.