(022) Penile Implant Reservoir Placement: The Current Utilized Various Techniques and the Associated Outcome: Systematic Review and Meta-Analysis
Authors: Mahdi M , Khalafalla K , El-Achkar A , Algahiny A T , Slovacek H , Nguyen T , Wang R 
Published: March 2024

Abstract

Introduction
Many innovations in the field of inflatable penile prosthesis (IPP) has been emerged. Since the introduction of the IPP, reservoir positioning in the space of Retzius (SOR) was considered the classical approach that had been utilized for many years. However, in certain group of patients, reservoir insertion in such space might be difficult or even risky. As a result, many alternatives for the reservoir placement outside the SOR has emerged with the intent of safe and reliable reservoir placement.

Objective
To conduct a systematic review for the studies evaluating the outcomes of different techniques used for IPP reservoir placement to look for possible superiority of any approach over others.

Methods
A systemic review was performed utilizing (PRISMA) statement. The PubMed and Google scholar were used to look for articles published up to January 2023. Original articles reporting different techniques for IPP reservoir placement and evaluating the associated outcomes were included. Data regarding study design, sample size, approach of reservoir placement, surgical technique, device type and reported outcomes (infection rate, bladder/bowel/vascular injury, reservoir herniation, mechanical failure, auto-inflation, reservoir palpability and patients’ satisfaction) were collected. Pooled proportion was calculated and included in the meta-analysis. The Newcastle-Ottawa scale was used for assessing the quality of the studies.

Results
A total of 23 articles meeting the inclusion criteria, all were retrospective reviews. 11 compared more than one technique for reservoir placement whereas 12 described a single technique. In total, techniques for 6 main different reservoir locations has been reported, including SOR (7 studies), submuscular/subrectus (6 studies), Lateral retroperitoneal (1 study), subcutaneous (1 study), sub external oblique (1 study) and intraperitoneal (1 study). Another 7 modifications have been described for the SOR technique (traditional SOR, accessing SOR using blunt scissor in post-prostatectomy patients, accessing SOR using blunt scissor in virgin cases, dilating SOR using catheter balloon, accessing SOR under direct vision, accessing SOR through external oblique fascia incision, and the addition of The Tubing Hitch&Lasso, Intussusception Anchor technique (THALIA)). Another 6 modifications for the submuscular/subrectus approach have been described (posterior to transversalis fascia (PTF), anterior to transversalis fascia (ATF), high submuscular, subrectus using counter incision, subrectus with the addition of THALIA, low submuscular with trans-fascial-fixation (TFF)). None of the studies have proven the superiority of one technique over others, with most of the techniques has comparable intra-operative and post-operative outcomes (table 1). The addition of anchoring step (THALIA or TFF) resulted in neglected risk of reservoir herniation, however, related studies has small sample size with no comparison groups. Meta-analysis for the studies of SOR (n=7) and submuscular/subrectus (n=6) groups showed a statistically significant difference only in the herniation rates (figure 1). 10 studies were of strong quality (8 stars) while the remaining 13 studies were of poor quality.

Conclusions
Modest evidence suggests a comparable favorable outcome of various approaches used for IPP reservoir placement. The lack of enough prospective trials, short term follow up, and diversity in the techniques prescribed prevent the ability to build strong evidence. For the purpose of supporting the superiority of any technique, further prospective studies on a larger number of patients with long-term follow up are needed to reach a solid verdict.

Disclosure
No.