Impact of Radiation and Transcorporeal Artificial Sphincter Placement in Patients with Prior Urethral Cuff Erosion: Results from a Retrospective Multicenter Analysis.

PURPOSE: Many providers elect to use a transcorporeal approach for artificial urinary sphincter placement in an attempt to minimize risks, given the increased risk of complications in revision cases. We present outcomes in a multicenter retrospective analysis of artificial urinary sphincter cuff reimplantation in patients with prior cuff erosion with special consideration given to the transcorporeal approach. MATERIALS AND METHODS: We compiled a multi-institutional database of patients who underwent artificial urinary sphincter reimplantation after prior urethral erosion. Of the 34 identified patients 24 underwent transcorporeal cuff replacement. Patients with transcorporeal cuff replacement were further analyzed with specific stratification for radiation therapy. RESULTS: The rate of subsequent complications after eroded cuff reimplantation was 32.4% (11 of 34 patients). The most frequent complication was recurrent erosion, which developed in 9 of the 34 patients (26.4%). Repeat artificial urinary sphincter complications developed more frequently in patients with history of radiation compared to nonirradiated patients (8 of 16 or 50% vs 3 of 18 or 16.7%). However, this difference was not statistically significant (p = 0.066). The transcorporeal technique was applied in 24 of 33 patients (70.5%) and relative to the nontranscorporeal group there was no difference in the complication rate (p = 0.438). On subgroup analysis of the transcorporeal group there was a higher rate of repeat complications in irradiated patients (p = 0.006). CONCLUSIONS: These data suggest that transcorporeal cuff reimplantation may not decrease the incidence of repeat complications after prior cuff erosion. However, radiation therapy is associated with a worse outcome even when transcorporeal cuff placement is performed.

Prior Radiation Therapy Decreases Time to Idiopathic Erosion of Artificial Urinary Sphincter: A Multi-Institutional Analysis.

PURPOSE: Substantial controversy and conflicting data exist regarding the survival of the artificial urinary sphincter in patients with prior radiation therapy. We present data from a multi-institutional analysis examining the effect of prior radiation for prostate cancer on device survival. MATERIALS AND METHODS: A database was compiled of patients with artificial urinary sphincter cuff erosion, which included demographic and comorbid patient characteristics, functional analyses and interventions. We identified 80 patients with iatrogenic or idiopathic artificial urinary sphincter erosion. Idiopathic erosion cases were further analyzed to determine factors influencing device survival with specific stratification for radiation therapy. RESULTS: A total of 56 patients were identified with idiopathic artificial urinary sphincter erosion. Of those men 33 (58.9%) had not undergone radiation treatment while 23 (41.1%) had a history of brachytherapy or external beam radiotherapy. In patients without radiation erosion-free median device survival was 3.15 years (95% CI 1.95-5.80), in contrast to the median device survival of only 1.00 year (95% CI 0.36-3.00) in irradiated patients. The erosion-free survival experience of patients with vs without radiation differed significantly (Wilcoxon-Breslow test for equality of survivor functions p = 0.03). CONCLUSIONS: Radiation therapy in patients with known idiopathic cuff erosion in this contemporary analysis correlated with significantly increased time to erosion. Mean time to idiopathic cuff erosion was accelerated by approximately 2 years in irradiated cases. To our knowledge these data represent the first demonstration of substantial outcome differences associated with radiation in patients with an artificial urinary sphincter who present specifically with cuff erosion.

Urethral Stricture Outcomes After Artificial Urinary Sphincter Cuff Erosion: Results From a Multicenter Retrospective Analysis.

OBJECTIVE: To evaluate the influence of both repair type and degree of cuff erosion on postoperative urethral stricture rate. Sparse literature exists regarding patient outcomes after artificial urinary sphincter (AUS) cuff erosion. Surgeons from 6 high-volume male continence centers compiled a comprehensive database of post-erosion patients to examine outcomes. MATERIALS AND METHODS: This retrospective multi-institution study included 80 patients treated for AUS cuff erosions. Seventy-eight patients had specific information regarding post-cuff erosion urethral strictures. Erosion patients were categorized into 1 of 3 repair types at the time of explant surgery: catheter only, single-layer capsule-to-capsule repair (urethrorrhaphy), and formal urethroplasty. Operative notes and available medical records were extensively reviewed to collect study data. RESULTS: Twenty-five of 78 patients manifested a urethral stricture after AUS cuff erosion (32%). More strictures occurred among patients who underwent urethrorrhaphy (40% vs 29% for catheter only and 14% for urethroplasty). Stricture rates did not vary significantly by repair type (P = .2). Strictures occurred significantly more frequently in patients with complete cuff erosions (58%) as compared to partial erosions (25%, P = .037). A trend was detected regarding increased percentage of erosion correlating with increased stricture rate, but this did not reach statistical significance (P = .057). Partially eroded patients were more likely to undergo urethrorrhaphy repair (60%, P = .002). CONCLUSION: Urethral stricture was more likely to occur after complete cuff erosion as opposed to partial erosion in this multicenter retrospective population. Repair type, whether catheter only, urethrorrhaphy, or formal urethroplasty, did not appear to influence postoperative stricture rate.

Generation, validation and humanisation of a novel insulin resistant cell model.

Insulin resistance is a characteristic of type 2 diabetes and is a major independent risk factor for progression to the disease. In particular, insulin resistance associates with increased body fat and almost certainly contributes to the dramatic increase in risk of type 2 diabetes associated with obesity. Therefore, in order to design truly effective insulin sensitising agents, targeted at the mechanism of disease development, we aimed to generate an obesity-related insulin resistant cell model. Rat hepatoma cells were grown in the presence of serum isolated from obese rodents or obese human volunteers, and the insulin sensitivity of the cells monitored over time by measuring a well-characterised insulin regulated gene promoter. Higher insulin concentrations were required to fully repress the gene in the cells grown in obese rodent serum compared with those grown in serum from lean rodents (almost a 10-fold shift in insulin sensitivity). This was reversed by restoration of normal growth medium, while the insulin resistance was prevented by pioglitazone or metformin. Meanwhile, growth of cells in serum collected from obese human volunteers with diabetes also reduced the insulin sensitivity of the rat cells. No clinical marker predicted the degree of insulin resistance that was generated by the human serum. We have developed a novel insulin resistant cell model for the study of the molecular development of obesity-linked insulin resistance, screen for compounds to overcome obesity-related insulin resistance and potentially search for novel serum biomarkers of insulin resistance.