All Products
Also known as
High submuscular reservoir placement, Submuscular reservoir placement, Alternative reservoir placement, Nontraditional reservoir placement, Abdominal wall reservoir placement, Ectopic IPP reservoir placement
Definition
Reservoir placement is the step of three-piece inflatable penile prosthesis (IPP) surgery in which the saline-filled fluid reservoir is positioned in the lower abdomen. The device consists of paired cylinders in the corpora cavernosa, a pump in the scrotum and a reservoir placed either in the retropubic space (space of Retzius) or under the rectus abdominis or external oblique musculature.1 The space of Retzius remains a familiar location for first-time implants, whereas submuscular placement has gained popularity for its versatility and lower risk of visceral injury.2 In the high submuscular, or ectopic, technique the reservoir lies anterior to the transversalis fascia but beneath the abdominal muscles.3 Because retropubic placement is usually performed blindly, the patient is at risk of bowel, bladder or vascular injury,4 and the EAU Guidelines describe non-infectious reservoir complications including injury to the bladder, bowel and blood vessels.5 Other alternative sites include the high extraperitoneal space, the lateral retroperitoneal space for a hostile pelvis and, mainly in very obese patients, a subcutaneous position.2,6
Clinical Context
Patient history, such as prior prostatectomy, may lead surgeons to choose ectopic rather than retropubic reservoir placement.7 The risk of injury during reservoir insertion is greatest in men with a history of radical prostatectomy, cystectomy, pelvic radiotherapy or mesh hernia repair, where scarring obliterates natural planes, and for such hostile pelvic anatomy a high submuscular, extraperitoneal or other ectopic site is recommended as the primary strategy.6 Reviews also list radical cystectomy with neobladder reconstruction, kidney transplantation and inguinal hernia repair among challenging prior pelvic operations.8 In 12 men who had undergone radical cystectomy, transfascial high submuscular placement was described as a safe method, with one reservoir herniation during follow-up.9 For patients considered at high risk of complications with reservoir placement, such as after previous abdominal surgery, the EAU Guidelines consider a two-piece inflatable prosthesis a viable option,5 because it avoids an intra-abdominal reservoir.10
Technique aims to protect the bladder and secure the intended layer. Urethral catheterisation before reservoir placement is a critical step to reduce the risk of bladder perforation.11 Correct placement and a back-pressure test after filling are described as mandatory to prevent autoinflation.12 For ectopic placement, a space is developed above the transversalis fascia and the reservoir is moved as far superiorly as possible; Scarpa’s fascia must be cleared, otherwise the reservoir ends up subcutaneous, creating a visible and palpable bulge.3 A separate counter-incision or a direct-vision transfascial approach can replace blind transinguinal passage.8
A systematic review of 70 articles covering 9,565 patients found no elevated rates in safety outcomes between retropubic and ectopic placement and judged ectopic placement comparable in safety, efficacy and patient satisfaction.7 On cross-sectional imaging, high submuscular reservoirs were less likely than retropubic ones to cause a mass effect on the bladder (9% vs 72%) or iliac vessels (4% vs 34%).13 Blind placement is nevertheless imprecise: in a cadaver model, 80% of high submuscular reservoirs lay anterior to the transversalis fascia, but 10% were retroperitoneal, 5% preperitoneal and 5% intraperitoneal.14 In patients, this variability did not seem to affect safety, and reservoir-related complications remained rare.15 Palpability is the main trade-off: 64.3% of men with high submuscular reservoirs could feel the reservoir immediately after surgery, although this disappeared in 80% of that group (BMI above 26.5) once a capsule had formed at 3 months; 88% of these men were satisfied, compared with 81% after retropubic placement.16