Okutucu T M, Telli O, Ozturk E, Suer E, Hamidi N, Burgu B
Department of Urology, Ankara University School of Medicine, Ankara, Turkey.
Department of Pediatric Urology, Ankara University School of Medicine, Ankara, Turkey.
J Pediatr Urol. 2015 Apr;11(2):86.e1-6. doi: 10.1016/j.jpurol.2014.12.008. Epub 2015 Mar 4.
Bladder augmentation is used for the treatment of bladder dysfunction in order to minimize intravesical pressure and increase bladder capacity. However, less-invasive procedures, such as autoaugmentation, have been proposed due to several complications that have occurred using bowel and gastric segments. The technique of autoaugmentation involves wide excision of the detrusor by leaving the bladder mucosa intact and has shown increased bladder capacity and compliance. An additional step to keep the achieved surface area of this non-contractible bladder segment and, thus, bladder capacity, was reported by using an intravesical balloon to prevent shrinkage of the surgically achieved diverticulum during autoaugmentation. On the other hand, adhesion barriers (AB) with absorbable hydrogel, which can spare tissue and organ plans, are used to prevent postsurgical adhesions. The efficacy of sprayable AB has been demonstrated in animal models and it is now mostly used in laparoscopic surgeries.
The present study aimed to compare the efficacy of AB and/or intravesical balloon insertion, which might potentially improve the urodynamic and histopathological outcomes of autoaugmentation in a rabbit model.
A total of 25 New Zealand rabbits were included in the study. Following the surgical reduction to form a low-capacity bladder model (35-40% of the initial volume), standard detrusorotomy was performed in all groups except the sham group. Group 2 had only autoaugmentation as the control group. The bladders in Group 3 were supported with an intravesical balloon. An Adhesion Barrier System (CUI Tissue Expander) was used for all bladders in Group 4, without balloon inflation. In Group 5, both intravesical balloon inflation and adhesion barrier application were performed following autoaugmentation. Urodynamic evaluations were performed at day 0 before reduction, day 0 after reduction, and the 90th postoperative day. Capacity and compliance measurements were noted. Bladders were histopathologically evaluated. Expression of CD31 (microvessel density) and fibrosis were noted.
Autoaugmentation does not result in a reliable increase in bladder capacity and compliance when compared to a sham group. Urodynamic measurements were similar in balloon-inflated groups (Group 3 and Group 5), showing a statistically significant improvement. Sprayable AB system alone revealed a slight, but not statistically significant, increase (Table). No significant differences between all five groups were detected regarding microvessel density (CD31 expression) and fibrosis.
In the present study, the intravesical balloon application (IVBA) efficiency was investigated alone and in combination with AB. The main basis of this study were the previous findings, which demonstrated prevention or decrease in the contraction of diverticula by IVBA. The role of AB alone or within a combination was also evaluated. Adhesion barriers are mostly used in laparoscopic gynecologic and colorectal operations. They decrease the postoperative adhesions by forming a physical barrier. In the present study, it was thought that AB might reduce postoperative adhesions and enhance the outcome of autoaugmentation. One of the most important outcomes was the inconsistency of fibrosis density with final bladder capacity and compliance values; this finding did not support the role of fibrosis prevention with IVBA. The present study had some limitations: the partial cystectomy method, which was used to form a low-compliance bladder, is a different clinical condition to neurogenic bladder, and a rectal catheter was not used during urodynamic evaluation. General anesthesia and muscle relaxant were performed during urodynamy and abdominal contractions were not seen.
Bladder autoaugmentation in a rabbit model, followed by intravesical balloon inflation offers improvement in bladder capacity and compliance. The use of sprayable adhesion barrier hydrogel technology may facilitate tissue healing and result in it being easier to maintain the success achieved by surgery when only supported with an intravesical balloon.
膀胱扩大术用于治疗膀胱功能障碍，以尽量降低膀胱内压力并增加膀胱容量。然而，由于使用肠段和胃段进行膀胱扩大术出现了多种并发症，因此有人提出了如自体扩大术等侵入性较小的手术方法。自体扩大术技术包括在保留膀胱黏膜完整的情况下广泛切除逼尿肌，已显示出膀胱容量和顺应性增加。据报道，在自体扩大术中使用膀胱内球囊可防止手术形成的憩室收缩，从而保持该不可收缩膀胱段的表面积，进而维持膀胱容量。另一方面，可吸收水凝胶制成的粘连屏障（AB）可避免组织和器官粘连，用于预防术后粘连。可喷涂AB在动物模型中的疗效已得到证实，目前主要用于腹腔镜手术。
本研究旨在比较AB和/或膀胱内插入球囊的疗效，这可能会改善兔模型中自体扩大术的尿动力学和组织病理学结果。
本研究共纳入25只新西兰兔。手术缩小膀胱容量以形成低容量膀胱模型（初始容量的35 - 40%）后，除假手术组外，所有组均进行标准逼尿肌切开术。第2组仅进行自体扩大术作为对照组。第3组的膀胱用膀胱内球囊支撑。第4组所有膀胱均使用粘连屏障系统（CUI组织扩张器），不进行球囊充气。第5组在自体扩大术后同时进行膀胱内球囊充气和应用粘连屏障。在缩小膀胱容量前的第0天、缩小膀胱容量后的第0天以及术后第90天进行尿动力学评估。记录容量和顺应性测量值。对膀胱进行组织病理学评估。记录CD31（微血管密度）的表达和纤维化情况。
与假手术组相比，自体扩大术并未可靠地增加膀胱容量和顺应性。球囊充气组（第3组和第5组）的尿动力学测量结果相似，显示出统计学上的显著改善。单独使用可喷涂AB系统显示出轻微增加，但无统计学意义（表）。在微血管密度（CD31表达）和纤维化方面，所有五组之间未检测到显著差异。
在本研究中，单独及联合AB研究了膀胱内球囊应用（IVBA）的效果。本研究的主要依据是先前的研究结果，即IVBA可预防或减少憩室收缩。还评估了单独使用AB或联合使用AB的作用。粘连屏障主要用于腹腔镜妇科和结直肠手术。它们通过形成物理屏障减少术后粘连。在本研究中，认为AB可能会减少术后粘连并提高自体扩大术的效果。最重要的结果之一是纤维化密度与最终膀胱容量和顺应性值不一致；这一发现不支持IVBA预防纤维化的作用。本研究存在一些局限性：用于形成低顺应性膀胱的部分膀胱切除术方法与神经源性膀胱的临床情况不同，并且在尿动力学评估期间未使用直肠导管。尿动力学检查期间进行了全身麻醉和肌肉松弛，未观察到腹部收缩。
兔模型中的膀胱自体扩大术，随后进行膀胱内球囊充气可改善膀胱容量和顺应性。使用可喷涂粘连屏障水凝胶技术可能有助于组织愈合，并且在仅用膀胱内球囊支撑时，更容易维持手术取得的效果。
