Bugeja Simon, Ivaz Stella L, Frost Anastasia, Andrich Daniela E, Mundy Anthony R
Reconstructive Urology Unit, University College London Hospitals, London, UK.
BJU Int. 2016 Apr;117(4):669-76. doi: 10.1111/bju.13324. Epub 2015 Oct 12.
To investigate the concept of 'urethral atrophy', which is often cited as a cause of recurrent incontinence after initially successful implantation of an artificial urinary sphincter (AUS); and to investigate the specific cause of the malfunction of the AUS in these patients and address their management.
Between January 2006 and May 2013, 50 consecutive patients (mean age 54.3 years) with recurrent incontinence had their AUS explored for malfunction and replaced with a new device with components of exactly the same size, unless there was a particular reason to use something different. Average time to replacement of the device was 10.1 years. The mean follow-up after replacement of the device was 24.7 months. All patients without an obvious cause for their recurrent incontinence had preoperative urodynamic evaluation, including measurement of the Valsalva leak point pressure (VLPP) and the retrograde cuff occlusion pressure (RCOP). After explantation of the AUS in patients without any apparent abnormality of the device at the time of replacement, the pressure generated by the explanted pressure-regulating balloon (PRB) was measured manometrically, when this was possible. In a select group of six consecutive patients of this type, the fibrous capsule surrounding the old cuff was incised then excised to expose and evaluate the underlying corpus spongiosum.
In 31 of the 50 patients (62%) undergoing exploration, a specific cause for the malfunction of their AUS was defined. In the other 19 patients (38%) no cause was found, either preoperatively or at the time of exploration, other than a low VLPP and RCOP. A typical 'waisted' or 'hour-glass' appearance of the underlying corpus spongiosum was demonstrable, to some degree, on explanting the cuff in all cases. In the six patients in whom the restrictive sheath surrounding the cuff was excised, the urethral circumference immediately returned to normal after the compressive effect of the sheath was released. Manometry of the explanted PRBs, when this was possible, showed a loss of pressure in all instances. Replacement of the explanted AUS with a new device with the same size cuff and PRB in 14 of these 19 patients was successful in 12 (85.7%).
These results, and other theoretical considerations, suggest that recurrent incontinence, years after initially successful implantation of an AUS, is because of material failure of the PRB, probably attributable to its age and consequent loss of its ability to generate the pressure it was designed to produce, and that urethral atrophy does not occur. Simply replacing the old device with a new one with the same characteristics, unless there is a particular reason to do otherwise, is usually successful and avoids the complications of alternatives such as as cuff downsizing, implanting a PRB with a higher pressure range, implantation of a second cuff or transcorporeal cuff placement, all of which have been advocated in these patients.
探讨“尿道萎缩”这一概念，其常被认为是人工尿道括约肌（AUS）首次植入成功后复发性尿失禁的原因；并研究这些患者中AUS功能障碍的具体原因及处理方法。
2006年1月至2013年5月，连续50例（平均年龄54.3岁）复发性尿失禁患者因AUS功能障碍接受探查，并更换为尺寸完全相同部件的新装置，除非有特殊原因使用不同的部件。装置更换的平均时间为10.1年。装置更换后的平均随访时间为24.7个月。所有无明显复发性尿失禁原因的患者术前行尿动力学评估，包括测定瓦尔萨尔瓦漏点压力（VLPP）和逆行袖带闭塞压力（RCOP）。对于更换时装置无明显异常的患者，在取出AUS后，若可行，通过测压法测量取出的压力调节球囊（PRB）产生的压力。在一组连续的6例此类患者中，切开并切除围绕旧袖带的纤维囊，以暴露并评估其下方的海绵体。
在接受探查的50例患者中，31例（62%）明确了AUS功能障碍的具体原因。在另外19例患者（38%）中，术前或探查时除VLPP和RCOP较低外未发现其他原因。在所有病例中，取出袖带时，在一定程度上可显示出下方海绵体典型的“束腰”或“沙漏”样外观。在6例切除袖带周围限制性鞘膜的患者中，鞘膜压迫作用解除后尿道周长立即恢复正常。在可行的情况下，对取出的PRB进行测压，结果显示所有情况下压力均丧失。在这19例患者中的14例，用尺寸相同的袖带和PRB的新装置替换取出的AUS，其中12例（85.7%）成功。
这些结果以及其他理论考虑表明，AUS首次植入成功数年之后出现的复发性尿失禁是由于PRB的材料故障，可能归因于其使用年限以及随之而来的无法产生其设计压力的能力丧失，且不存在尿道萎缩。除非有特殊原因，简单地用具有相同特征的新装置替换旧装置通常是成功的，并且可避免诸如袖带缩小、植入压力范围更高的PRB、植入第二个袖带或经体部袖带放置等替代方法的并发症，而这些替代方法在这些患者中均有人主张使用。
