Introduction
A radical cystectomy (RC) is an effective method for the treatment of invasive bladder cancer, with an ileal orthotopic neobladder (ONB) reconstruction being an ileal method of urinary diversion [
1,
2]. An orthotopic neobladder should enable normal bladder function, keep adequate capacity at low pressure, create a continence mechanism, and prevent upper urinary tract dilatation via an antireflux mechanism [
3].
Initially, as described by Camey, a small tubular bowel segment has been used as a bladder substitute for the creation of an ONB and a tubular bowel segment anastomose is performed to the urethra directly without detubularization [
4]. Subsequently, many different types of orthotopic neobladders using various gastrointestinal segments (ileum, ileo-colon, colon, sigmoid colon) have been reported [
5‐
7]. Nowadays, intestinal detubularization plays a major role in constructing an adequate capacity reservoir with low pressure. While the most popular technique has been the one reported by Studer et al., who created a bladder substitute using a detubularized ileal pouch after an RC [
8], in the MIS era, simple novel intracorporeal techniques have been described of which the Y pouch may be the technique of interest [
9‐
11].
The aim of the study was to explore a new method of constructing an ONB in the Y-pouch configuration. Focusing on patients treated with open RC, we describe the steps followed to create the Y-pouch IONB. We also compared the perioperative and functional outcomes of this approach with those of the Studer neobladder technique.
Discussion
ONB are used for urinary diversion after RC, and the use of different types has been reported. Although novel techniques have been described, controversies related to their efficacy and safety remain, and their use depends chiefly on surgeon preferences and experiences. Thus, the author has intended to perform the neobladder using a Y-pouch formation technique, which is safe and easy to construct and which also ensures a low pressure with an appropriate capacity. Furthermore, the continence function in both the day- and nighttime must be achieved [
14]. The standard technique involves the creation of the Studer neobladder; however, other ileo-colonic neobladder techniques have also been used, such as the Karolinska-modified Studer neobladder, the University of Southern California-modified Studer neobladder, the N pouch, the W pouch, the modified Y-shaped, and other orthotopic neobladders for which the long-term outcomes are comparable in oncological and functional outcomes to standard Studer technique or ileal conduit [
7,
15‐
18]. Although the Studer technique has significant advantages over the other alternatives. The Studer pouch has proved to be a reproducible technique, with good operative and functional outcomes obtained in multiple different centers; many of the largest series have reported daytime and nighttime continence rates reaching 85% and 70%, respectively [
8]. However, no single neobladder technique has been shown to be clearly superior. Adherence to certain surgical guiding principles is paramount. The intracorporeal Studer pouch is a reproducible technique that provides favorable functional outcomes and is currently supported by the largest body of literature. Furthermore, the surgeons often select 1 or 2 additional techniques including a W pouch and Y pouch that are considered suitable and provide the best results and experienced that the Y-pouch technique has shown simple, fast, and less mucus production in the pilot cases. Specifically, in the Y-pouch group, the left side ureter is directly anastomosed to the left afferent limb of the Y-shaped neobladder, while in the Studer group, the left side ureter passes behind the mesentery. This observation emphasizes the significance of an in-place anastomosis between the left side ureter and the left afferent limb of the Y-pouch neobladder, which is considered one of the advantages of the Y-pouch technique over the Studer technique. Furthermore, this advantage makes the Y-pouch neobladder more suitable for laparoscopic or robotic surgery applications, providing increased comfort during the procedure.
The development of surgical techniques that are easy to perform and yield satisfactory long-term results is appreciated and necessary. Therefore, the authors performed a neobladder using a Y-pouch technique. A recent study also reported on this technique using a three-dimensional surgical postoperative pouch evaluation of the Y-pouch neobladder [
18].
A simple shape, resembling that of the original bladder configuration, and ease of use are the main advantages of the Y-pouch. A 40-cm ileal segment is used, and a uretero-ileal anastomosis is performed between the spatulated ureters into the intestinal mucosa of both the Y limbs of the neobladder using the modified Lich-Gregoir technique, directly mucosa-to-mucosa without any anti-reflux method or by creating a chimney. The major concerns surrounding the anastomosis stricture explain why we do not follow the antireflux method; another reason is to ensure its ease of use with the intracorporeal neobladder. While a critical point to be aware of when performing an orthotopic neobladder reconstruction is the protection of the upper urinary tract, our technique did not account for this. Moreover, the meta-analysis showed that the overall incidence of vesicoureteral reflux was higher with direct anastomosis than anti-reflux anastomosis, and the rate of vesicoureteral reflux was not directly related to the impairment of RFn. The anti-reflux mechanism of ONB was positively associated with a higher incidence of significant ureteroenteric anastomotic stricture compared to the direct approach, which can lead to kidney damage and an increased risk of secondary surgical procedures [
19].
However, compared to that in previous literature, the volume of blood loss in this study was higher, which was a point of concern. The issue of high blood loss in our study is indeed an important consideration. Radical cystectomy is a complex surgical procedure that involves meticulous dissection and removal of the bladder, along with lymph node dissection and urinary diversion. Despite our efforts to minimize blood loss during the procedure, certain factors may contribute to higher blood loss in our series. Such as the open approach and complexity of bladder cancer and the experience of surgeons.
The urethra strictures in 2 patients (11.1%) receiving the Y-pouch technique and 4 patients (14.8%) receiving the Studer technique required additional endoscopic treatment. A uretero-neobladder anastomosis was not found in any of the patients (0%) that underwent the Y-pouch technique; however, 1 patient that underwent the standard technique (3.7%) experienced this complication and was treated with additional open surgery. In our study, we observed a significant difference in the need for cystostomy between patients who underwent the Studer neobladder procedure and those who had the Y-pouch neobladder technique. The Studer neobladder, which involves constructing a reservoir using a longer segment of the ileum, often leads to increased mucus production, necessitating the use of cystostomy as an alternative method for urinary drainage. However, it is important to note that many centers do not utilize cystostomy after Studer pouch construction, which challenges the advantage previously suggested for the Y-pouch neobladder technique, and it is crucial to reevaluate the advantages of the Y-pouch neobladder. Although the absence of cystostomy in patients with the Y-pouch neobladder may not be a distinct advantage, it could still contribute to improved patient comfort and satisfaction. Furthermore, it is plausible that the lack of cystostomy in Y-pouch neobladder patients may have a favorable impact on postoperative urinary function and continence outcomes, without increasing the risk of inadequate drainage complications.
Metabolic acidosis occurring in the postoperative period and detected during the follow-up have been reported by several studies [
7,
8]; for example, in 1 study, 48% of patients with an ileal neobladder required alkalizing treatment for an acidotic imbalance [
7]. Moreover, the advantages of using a terminal ileal segment for an orthotopic urinary diversion to avoid metabolic complications have also been reported [
20]. Ideally, the terminal ileal loop is the most suitable bowel segment for an ONB. No metabolic complications in our patients during either the early or the mid-term follow-up periods were observed. The creatinine and eGFR values between the 2 groups showed significant differences and better results for the Y-pouch neobladder.
Our hypothesis is explained by the lower urinary contact area of the small bowel. Theoretically, a smaller urinary contact area in the small bowel segment of the Y-pouch neobladder might result in a reduced urine absorption and also by less mucus production from this technique, and it has been suggested that the Y-pouch neobladder technique may lead to less mucus production compared to Studer approaches.
Moreover, patients with bladder substitution achieved daytime control more rapidly than those who underwent a radical prostatectomy, and stress urinary incontinence was reported rarely. Additionally, it mentions that stress urinary incontinence (involuntary leakage of urine during physical activities or exertion) was rarely reported in the context of bladder substitution [
21]. Also, other results of continence in our cohort compared to other types of pouch such as N-shaped orthotopic ileal neobladder exhibited daytime continence rates were better than nighttime rates [
22].
The rate of outlet obstruction by local recurrence was 2%, that of gross hematuria 1%, and that of entero-reservoir fistulas 1–2%. Daytime continence at 12 months was 92%, while nighttime continence was lower around 80%. Transient or permanent urinary retention was seen in 11–12% of male patients. In both series, long-term upper urinary tract safety was good. The risk of stenoses of the uretero-intestinal anastomosis with consecutive loss of renal function decreased with the introduction of non-refluxing implantation techniques. The rate of long-term metabolic complications remains low when adequate substitution with sodium bicarbonate is guaranteed in patients with impaired renal function. Patient selection and meticulous postoperative follow-up contributed to achieve good long-term results after cystectomy and orthotopic ileal neobladder substitution of the two large series of patients from the Universities of Ulm and Bern [
23].
The current study analyzed the urodynamic findings of patients who underwent RC with ONB using a Y-shaped reconstruction compared to the Studer neobladder. The main findings were that Y-shaped neobladders met the requirement of a reservoir with high capacity, low pressure, appropriate voiding, and preservation of renal function compared to the Studer technique.
To date, there are no standard urodynamic values for the ileal neobladder. However, when compared to reference values of a native bladder in 50-year-old men, the urodynamic profile of our Y-shaped ICUD was consistent with a normo-capacity (300–600 ml) and normo-compliant bladder (low compliance less than 30 ml/cm H
2O for non-neurogenic bladder) [
24]. Although there is no widely accepted absolute normal compliance, it has been suggested that H
2O values > 12.5–30 ml/cm represent the lower limit of normal. Our patients in this cohort study had UDS outcomes similar to those with a Studer neobladder in our study and other studies in terms of compliance and capacity [
25‐
28], despite the absence of an afferent ileal segment an non-double-folding reconfiguration. Uroflowmetry data also showed mostly unobstructed maximum urinary flow (
Qmax > 10 ml/s) with low PVR in most of the patients, suggesting satisfactory bladder emptying. There were some patients who need clean intermittent-self catheterization as compared to other reports with the rate ranging from 0 to 20% [
27‐
32], but most of these patients had their urodynamic evaluation at 12 months, suggesting possible improvement of neobladder voiding over time. Interestingly, some patients in our series had neobladder wall over-activity during the cystometry filling phase, potentially causing transitory high internal pressure. This phenomenon, already reported in other series [
20,
23], might be caused by the residual peristaltic activity of the ileum and requires further urodynamic assessment. Despite this, none of our patients had any deterioration in renal function emphasizing that the Y-shaped ONB appeared to be safe and satisfactory from the urodynamic point of view.
Pouch calculi occurred in patients with stapled neobladders but were absent in those with hand-sewn pouches. The common symptom was gross hematuria, and the calculi, typically less than 1 cm in diameter, were detected using KUB system CT scans during follow-up. Transurethral endoscopic lithotripsy successfully treated the calculi without functional complications. Calcium oxalate was the stone component in all cases. Although stapled neobladders may increase the risk of pouch calculi, a previous study reported comparable rates of stone formation to hand-sewn neobladders. Intermittent self-catheterization was the only variable predicting stone formation. We understand that the management of pouch calculi can vary depending on factors such as the size, composition, and location of the calculi. Surgical removal may be necessary in some cases, while preventive measures such as maintaining appropriate hydration, implementing dietary modifications, and regular surveillance may help minimize the risk of pouch calculi formation [
33]. Furthermore, in addition to actions aimed to prevent infectious stones such as bladder and pouch irrigation, we recommended these patients undergo a full metabolic workup with targeted dietary changes and medical therapies.
However, there were some limitations of this study. It was a retrospective study that employed a small sample size of 36 patients who received the Y-pouch compared with the 54 patients who received the Studer neobladder. We also failed to present any long-term results (the follow-up period ended at 12 months postoperatively). However, the functional results and postoperative complication rate in the initial period associated with this technique were acceptable, and the trend of renal function parameters after an RC appeared better than that of the Studer technique. Future studies should include a larger number of patients and employ a prospective design to overcome the existing limitations. The Studer procedure and the Y-pouch technique presented in this study provide comparable perioperative outcomes in patients undergoing radical cystectomy with an ONB, at both the early and mid-term assessments. The Y-shaped neobladder meets the requirement of a reservoir with high capacity, low pressure, appropriate voiding, and preservation of renal function. Therefore, we propose the Y-pouch neobladder to be one of the alternative ileal neobladder techniques to the Studer neobladder. No questionnaires were used for sexual function or incontinence. Further prospective, randomized, controlled, comparative studies are needed to confirm its efficacy.
Publisher’s Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.