464
SUPPLEMENT ARTICLE The Evolution of the Inflatable Penile Prosthesis Reservoir and Surgical Placement Tariq Hakky, MD, MS,* Aaron Lentz, MD,† Hossein Sadeghi-Nejad, MD,‡ and Mohit Khera, MD, MPH, MBA§ *Urology, USF, Tampa, FL, USA; †Urology, Duke, Raleigh, NC, USA; ‡Urology, Rutgers, Hackensack, NJ, USA; §Surgery, Baylor College of Medicine, Houston, TX, USA DOI: 10.1111/jsm.13011
ABSTRACT
The traditional inflatable penile prosthesis (IPP) reservoir placement is below the transversalis fascia in the space of Retzius. In 2002, Dr. Steve Wilson described ectopic reservoir placement, thereby providing a safe and effective alternative for implant surgeons. This new approach obviated the need for a second incision and decreased operative times during surgery. In the manuscript, he also described the introduction of a reservoir lock-out valve, which prevents autoinflation of the penile implant. The development of lockout valves and flat reservoirs has contributed to the early success and feasibility of submuscular placement techniques. Thirteen years after Dr. Wilson’s pivotal study, this technique should be in the armamentarium of all urologic prosthetic surgeons. Accordingly, in certain subsets of patients, ectopic/ submuscular reservoir site placement should be considered a safe, effective alternative to standard reservoir placement in the space of Retzius. Hakky T, Lentz A, Sadeghi-Nejad H, Khera M. The evolution of the inflatable penile prosthesis reservoir and surgical placement. J Sex Med 2015;12(suppl 7):464–467. Key Words. Penile Prosthesis; Erectile Dysfunction; Penis; Impotence; Reservoir; Lock-Out Valve; Ectopic Placement
Introduction
I
n the 1970s, Scott et al. developed the first inflatable penile prosthesis (IPP) that ushered in a new era in the management of erectile dysfunction [1]. Since their inception, multiple innovations have been made to reduce device infection rates and to improve the function, reliability, and cosmesis of penile implants. Early IPP reservoir modifications that improved longevity included the developments of a seamless, spherical reservoir, kink resistant tubing, and elimination of the internal reinforcing rod or stem [2]. To date, there are two reservoirs available on the market. American Medical Systems (AMS, Minnetonka, MN, USA) has developed the Conceal™ (AMS) reservoir, which is used with the AMS inflatable implants. The Conceal has the capacity to hold up to 65–100 mL, depending upon surgeon preference. Coloplast utilizes a Cloverleaf™ (Coloplast, Minneapolis, MN, USA) reservoir system that
J Sex Med 2015;12(suppl 7):464–467
comes in two sizes: 75 cc and 125 cc. Both Titan Cloverleaf reservoirs also employ a specially engineered lock-out valve at the neck of the reservoir designed to prevent auto-inflation [2,3]. Auto-Inflation
Despite high satisfaction rates for the majority of patients with IPPs, a small subset report dissatisfaction with outcomes due to mechanical malfunction. A variety of mechanical failures can occur, including auto-inflation of the IPP, which can be annoying, embarrassing, and uncomfortable. Currently, most experts in the field attribute autoinflation to formation of a constrictive capsule surrounding the prosthesis reservoir balloon [4]. This issue commonly occurs in the early postoperative period, and it is caused by abdominal pressure forcing fluid from the reservoir into the cylinders [4]. While auto-inflation is generally a benign problem, it has been documented to cause © 2015 International Society for Sexual Medicine
465
Evolution of the Inflatable Penile Prosthesis Reservoir
Figure 1 Lockout valve figure. Pressure generated in the reservoir pushes the poppet down; thereby, “locking out” leakage that causes autoinflation. During implant inflation a vacuum is created by the bulb squeeze, which pushes the membrane inward so that it pushes the poppet open, allowing fluid to flow from the reservoir to the cylinders. At rest, the membrane relaxes and the poppet returns to the closed state. The pump/cylinder set generates back-pressure that pushes the membrane away from the poppet protecting against accidental contact [7].
severe consequences such as cylinder erosion described by Kobayashi et al. where the right cylinder eroded through the corpora caused by chronic auto-inflation [5]. Wilson et al. recommend that a capsulotomy be performed in order to reposition the reservoir. Additionally, laparoscopic ablation of the capsule has also been described, albeit this is difficult in the more obese patient [4,6]. Current auto-inflation rates in the literature are 2–3% of patients receiving the AMS 700CX implant and to date the only reported Coloplast rate of auto-inflation is that by Wilson et al. at 1.3% [4,6]. The rate of autoinflation may increase with increasing placement of ectopic reservoirs in the subfascial space hence the creation of a lockout valve has been quintessential in the surgeon’s transition from the space of Retzius (SOR) to ectopic reservoir placement. Lockout Valve
In 2000, Mentor Corporation (Santa Barbara, CA, USA), now Coloplast Corporation (Minneapolis, MN, USA) added an enhanced reservoir with a lockout valve to their line of IPPs. The lock-out mechanism contains a “poppet” valve that does not allow fluid to exit when pressure is applied to the reservoir [4]. Specifically, the lock-out valve works by responding to fluid pressure changes in the tubing to the prosthesis and not to pressure from the reservoir. During cylinder deflation, the valve opens to positive pressure in the tubing. During cylinder inflation, when the collapsed bulb recovers, negative pressure opens the valve (Figure 1). Therefore, negative pres-
sure must be created from the pump side to allow fluid to flow from the reservoir, and furthermore elevated reservoir pressure does not result in fluid flow into the cylinders. In contrast to Coloplast, AMS introduced the MS pump with a lock out valve in the pump itself in 2006. Dr. Wilson et al. published their experience with the Mentor Alpha-1 penile prosthesis with reservoir lock-out valve in 2002 [4]. From January 1, 1998 until April 1, 2001, 499 patients received an Alpha-1 penile prosthesis. All implants were placed via a high scrotal incision by a single surgical team. The standard nonlock-out reservoir was used in 284 virgin implants and 55 revision replacement implants. The newer lock-out valve reservoir was used in 114 virgin implants and 46 revisions. Of note, eight patients underwent ectopic reservoir placement between the anterior abdominal wall musculature and the transversalis fascia due to the obliterated retropubic space. In the immediate postoperative period, each patient in the lock-out valve group was specifically asked about experience with auto-inflation and additionally the penis was examined for evidence of auto-inflation. In the group with standard reservoir placement, early auto-inflation was recorded as a complaint in 37 patients (11%). In 20 cases the problem resolved and in 11 patients the problem persisted but was not considered bothersome enough to indicate additional surgery. Six patients (2%) elected capsulotomy to correct the problem. Of the eight lock-out valve implants placed ectopically, none of these patients reported autoinflation despite the theoretical higher pressure exerted in the submuscular space. No revision surgeries were performed for mechanical failure, infection, or patient dissatisfaction [4]. Although the Mentor Alpha-1 lock-out valve is certainly an example of keen mechanical engineering, the most noteworthy contribution of this article is the utilization of an ectopically placed lock-out valve reservoir in a subset of patients with an obliterated retropubic space. This landmark article could not have been timelier as it was published on the precipice of the robotic surgery revolution in which the standard retropubic approach to radical prostatectomy has been nearly abandoned for the intraperitoneal robot-assisted laparoscopic prostatectomy. Reservoir Placement Locations
Several different approaches for placement of the IPP have been reported, including penoscrotal, J Sex Med 2015;12(suppl 7):464–467
466 infrapubic, suprapubic, and perineal locations, each with advantages and disadvantages. The penoscrotal approach is the most commonly used, with rates of 80% [3,5]. Traditional reservoir placement is in the SOR, which is in close proximity to the iliac vein and bladder. In an effort to avoid the time and morbidity of a second incision, Wilson et al. described ectopic placement of IPP reservoirs in 2002 [4]. This transition would not have been as fluid without the advance of the lockout valve on the reservoir. Dr. Henry et al. recently stressed the perils of traditional reservoir placement based on the anatomical proximity of major structures in the prevesical space [8]. Based on cadaveric measurements, the external inguinal ring was only 2.5– 4 cm from the external iliac vein, 5.3–8 cm from the decompressed bladder, and 2–4 cm from the filled bladder. Due to the proximity of the iliac vessels and the bladder to the space of retzius explains its occasional injury when the reservoir is placed in this location [8]. Previous pelvic surgery alters the surgical planes and makes injury more likely. To minimize the risk of adverse outcomes, alternative sites for abdominal reservoir placement have been described. Alternative reservoir placement sites include: intrabadominal, submusclar, lateral retroperitoneal placement via second incision, subcutaneous placement via second incision, and scrotally after orchiectomy [9,10]. Although serious complications such as vascular, bladder and bowel injuries are rare, they have been associated with retropubic reservoir placement and are disastrous when they occur. In a recent literature review by Ross et al., the most common complication of SOR reservoir placement was erosion of the reservoir into the bladder; which compromised 15/37(41%) of the cases. Presenting with common symptom of bladder erosion was hematuria. Compression of the external iliac vein was also a frequently reported complication noted in 5/37 (14%) cases [3]. Complications from SOR reservoir placement exist even in low risk patients and for this reason, ectopic reservoir placement has gained popularity in recent years. This paradigm shift in reservoir placement would be difficult without the lock-out valve thus preventing autoinflation. Reservoir placement is generally divided into location based on the reservoirs location in relation to the transversalis fascia as described by Stembler et al. [11] Once the transversalis fascia is perforated, the SOR is entered; however, an J Sex Med 2015;12(suppl 7):464–467
Hakky et al. “ectopic” location is commonly coined phrase of reservoir placement between the transversallis fascia and the rectus muscle. Prior to creation of the reservoir space, the bladder is emptied by having the patient void preoperatively or via catheterization intra-operatively. During creation of the space, the pubic tubercle is used as a landmark for guiding the finger into the external inguinal ring. Dissection is then made medial to the external ring and superior to the pubic bone. In patients without any scarring in the SOR due to pelvic surgery, using a finger, scissors, pointed clamp, or nasal speculum can be used to gently perforate transversalis fascia in a downward fashion thus entering the SOR. The reservoir lies behind the pubic bone if performed penoscrotally or more toward the head if an infrapubic approach is utilized [9,11]. In patients where scarring exists in the retroperitoneum the SOR may no be easily accessible resulting in inadvertent intraperitoneal reservoir placement. The most commonly used approach when placing a reservoir ectopically is to create the space for the reservoir without perforating the tranversalis fascia while using a nasal speculum, finger or forceps to perforate the back wall of the inguinal canal, thus creating a space anterior to transversalis fascia but posterior to the muscle layers of the abdomen. A single suture can be preplaced across the ostium of the space to prevent postoperative reservoir displacement during valsalva. This location offers the advantage of reduced risk of injury to intra-abdominal structures but may be more palpable and prone to herniation [9]. In April 2015, Coloplast’s cloverleaf reservoir with lock-out valve received approval from The Center for Devices and Radiological Health of the Food and Drug Administration for changes in labeling instruction for use to incorporate ectopic reservoir placement [12]. This approval is the first of its kind and gives prosthetic surgeons a new, alternative surgical method for men undergoing IPP placement where hitherto all ectopic reservoir placement was done off label. Ectopic Outcomes
Since Dr. Wilson’s publication in 2002, many prominent urologic prosthetic surgeons have documented the safety and efficacy of ectopic reservoir placement in both infrapubic and penoscrotal cases [2,10,11,13]. The importance of alternative placements was highlighted during the Sexual Medicine Society of North America annual
Evolution of the Inflatable Penile Prosthesis Reservoir meeting in 2011. More than 100 registered attendees participated in a poll querying opinions on alternative IPP reservoir placement. Participants reported that IPP reservoirs are either sometimes (46%) or frequently (36%) harder to place in the space of Retzius among robotic-assisted laparoscopic prostatectomy patients and that reservoir placement outside of the space of Retzius is sometimes (54%) or frequently (35%) advantageous for patients’ safety. Respondents agreed (97%) that physician-training courses should specifically include content relating to alternative reservoir placement techniques [10]. Stembler et al. did a retrospective review of 2,687 patients who had ectopic reservoir IPP reservoir placement. Bladder injury occurred in two patients (0.09%), herniation occurred in eight patients (1.4%), and two patients (0.09%) had autoinflation [10]. A potential downside to ectopic placement include reservoir palpability is more likely to occur in slender patients. This occurred in the series in 15 patients (3.4%); however, only two desired corrective surgery [13]. In an effort to decrease the rates of hernia formation and palpability, Dr. Morey introduced a high submuscular approach [13]. Chunge et al. did a retrospective report on their 2-year experience with high submusclar IPP reservoir placement and included a patient questionnaire. Instead of using scissors or a nasal speculum, a Foerster lunggrasping clamp is used to create a submuscular tunnel cephalad to the external inguinal ring through a scrotal incision. Of the 96 patients who underwent IPP placement with high submuscular reservoir placement, the reservoir was nonpalpable by the surgeon 73% of cases. The patients selfreported a satisfaction rate was 96% with only one patient in the series needing to undergo revision surgery for palpability [14]. Conclusions
Penile implants today provide high patient satisfaction with a lower rate of infection and mechanical failure [1]. The pioneering work of Dr. Wilson popularized the lock-out valve and the utility of ectopic reservoir placement. These innovations have been embraced by prosthetic urologists who strive for safe and predictable outcomes. As we witness the continued evolution of the IPP, we need to appreciate the innovative steps that have helped to evolve and improve this surgery. Accordingly, in certain subsets of patients, ectopic/submuscular
467
reservoir site placement should be considered a safe, effective alternative to standard reservoir placement in the space of Retzius. Corresponding Author: Tariq Hakky, MD, MS, Advanced Urology, 1557 Janmar Road, Snellville, GA 30087, USA. Tel: 678-344-8900; Fax: 678-6665201; E-mail: [email protected] Conflict of Interest: The author(s) report no conflicts of interest. References 1 Henry GD. Historical review of penile prosthesis design and surgical techniques: Part 1 of a three-part review series on penile prosthetic surgery. J Sex Med 2009;6:675–81. 2 Levine LA, Hoeh MP. Review of penile prosthetic reservoir: Complications and presentation of a modified reservoir placement technique. J Sex Med 2012;9:2759–69. 3 Simon R, Hakky TS, Henry G, Perito P, Martinez D, Parker J, Carrion RE. Tips and tricks of inflatable penile prosthesis reservoir placement: A case presentation and discussion. J Sex Med 2014;11:1325–33. 4 Wilson SK, Henry GD, Delk JR Jr, Cleves MA. The Mentor Alpha I penile prosthesis with reservoir lock-out valve: Effective prevention of auto-inflation with improved capability for ectopic reservoir placement. J Urol 2002;168:1475–8. 5 Kobayashi K, Hisasue S, Shimizu T, Itoh N, Tsuksamoto T. Erosion of an inflatable penile prosthesis due to autoinflation. J Urol 2004;50:515–7. 6 Abbosh PH, Thom MR, Bullock A. Laparoscopic capsulotomy to treat autoinflation of inflatable penile prostheses. J Sex Med 2012;9:1212–5. 7 Figure 1. (2012). Titan® The Serious Solution [Brochure]. Minneapolis, MN: Coloplast USA. 8 Henry G, Jones L, Carrion R, Bella A, Karpman E, Christine B, Kramer A. Pertinent anatomical measurements of the retropubic space: A guide for inflatable penile prosthesis reservoirs shows that the external iliac vein is much closer than thought. J Sex Med 2014;11:273–8. 9 Perito PE, Wilson SK. Traditional (retroperitoneal) and abdominal wall (ectopic) reservoir placement. J Sex Med 2011;8:656–9. 10 Karpman E, Sadeghi-Nejad H, Henry G, Khera M, Morey AF. Current opinions on alternative reservoir placement for inflatable penile prosthesis among members of the sexual medicine society of North America. J Sex Med 2013;10:2115–20. 11 Stember DS, Garber BB, Perito PE. Outcomes of abdominal wall reservoir placement in inflatable penile prosthesis implantation: A safe and efficacious alternative to the space of retzius. J Sex Med 2014;11:605–12. 12 U.S. Food and Drug Administration, Center for Devices and Radiological Health. FDA PMA supplemental approval. Approval for changes in the labeling of the Titan Inflatable Penile Prosthesis surgical protocol to incorporate ectopic placement. Silver Spring, MD: U.S. Food and Drug Administration; 2015. 13 Morey AF, Cefalu CA, Hudak SJ. High submuscular placement of urologic prosthetic balloons and reservoirs via transscrotal approach. J Sex Med 2013;10:603–10. 14 Chung PH, Morey AF, Tausch TJ, Simhan J, Scott JF. High submuscular placement of urologic prosthetic balloons and reservoirs: 2-year experience and patient-reported outcomes. Urology 2014;84:1535–40.
J Sex Med 2015;12(suppl 7):464–467
SUPPLEMENT ARTICLE The Evolution of the Inflatable Penile Prosthesis Reservoir and Surgical Placement Tariq Hakky, MD, MS,* Aaron Lentz, MD,† Hossein Sadeghi-Nejad, MD,‡ and Mohit Khera, MD, MPH, MBA§ *Urology, USF, Tampa, FL, USA; †Urology, Duke, Raleigh, NC, USA; ‡Urology, Rutgers, Hackensack, NJ, USA; §Surgery, Baylor College of Medicine, Houston, TX, USA DOI: 10.1111/jsm.13011
ABSTRACT
The traditional inflatable penile prosthesis (IPP) reservoir placement is below the transversalis fascia in the space of Retzius. In 2002, Dr. Steve Wilson described ectopic reservoir placement, thereby providing a safe and effective alternative for implant surgeons. This new approach obviated the need for a second incision and decreased operative times during surgery. In the manuscript, he also described the introduction of a reservoir lock-out valve, which prevents autoinflation of the penile implant. The development of lockout valves and flat reservoirs has contributed to the early success and feasibility of submuscular placement techniques. Thirteen years after Dr. Wilson’s pivotal study, this technique should be in the armamentarium of all urologic prosthetic surgeons. Accordingly, in certain subsets of patients, ectopic/ submuscular reservoir site placement should be considered a safe, effective alternative to standard reservoir placement in the space of Retzius. Hakky T, Lentz A, Sadeghi-Nejad H, Khera M. The evolution of the inflatable penile prosthesis reservoir and surgical placement. J Sex Med 2015;12(suppl 7):464–467. Key Words. Penile Prosthesis; Erectile Dysfunction; Penis; Impotence; Reservoir; Lock-Out Valve; Ectopic Placement
Introduction
I
n the 1970s, Scott et al. developed the first inflatable penile prosthesis (IPP) that ushered in a new era in the management of erectile dysfunction [1]. Since their inception, multiple innovations have been made to reduce device infection rates and to improve the function, reliability, and cosmesis of penile implants. Early IPP reservoir modifications that improved longevity included the developments of a seamless, spherical reservoir, kink resistant tubing, and elimination of the internal reinforcing rod or stem [2]. To date, there are two reservoirs available on the market. American Medical Systems (AMS, Minnetonka, MN, USA) has developed the Conceal™ (AMS) reservoir, which is used with the AMS inflatable implants. The Conceal has the capacity to hold up to 65–100 mL, depending upon surgeon preference. Coloplast utilizes a Cloverleaf™ (Coloplast, Minneapolis, MN, USA) reservoir system that
J Sex Med 2015;12(suppl 7):464–467
comes in two sizes: 75 cc and 125 cc. Both Titan Cloverleaf reservoirs also employ a specially engineered lock-out valve at the neck of the reservoir designed to prevent auto-inflation [2,3]. Auto-Inflation
Despite high satisfaction rates for the majority of patients with IPPs, a small subset report dissatisfaction with outcomes due to mechanical malfunction. A variety of mechanical failures can occur, including auto-inflation of the IPP, which can be annoying, embarrassing, and uncomfortable. Currently, most experts in the field attribute autoinflation to formation of a constrictive capsule surrounding the prosthesis reservoir balloon [4]. This issue commonly occurs in the early postoperative period, and it is caused by abdominal pressure forcing fluid from the reservoir into the cylinders [4]. While auto-inflation is generally a benign problem, it has been documented to cause © 2015 International Society for Sexual Medicine
465
Evolution of the Inflatable Penile Prosthesis Reservoir
Figure 1 Lockout valve figure. Pressure generated in the reservoir pushes the poppet down; thereby, “locking out” leakage that causes autoinflation. During implant inflation a vacuum is created by the bulb squeeze, which pushes the membrane inward so that it pushes the poppet open, allowing fluid to flow from the reservoir to the cylinders. At rest, the membrane relaxes and the poppet returns to the closed state. The pump/cylinder set generates back-pressure that pushes the membrane away from the poppet protecting against accidental contact [7].
severe consequences such as cylinder erosion described by Kobayashi et al. where the right cylinder eroded through the corpora caused by chronic auto-inflation [5]. Wilson et al. recommend that a capsulotomy be performed in order to reposition the reservoir. Additionally, laparoscopic ablation of the capsule has also been described, albeit this is difficult in the more obese patient [4,6]. Current auto-inflation rates in the literature are 2–3% of patients receiving the AMS 700CX implant and to date the only reported Coloplast rate of auto-inflation is that by Wilson et al. at 1.3% [4,6]. The rate of autoinflation may increase with increasing placement of ectopic reservoirs in the subfascial space hence the creation of a lockout valve has been quintessential in the surgeon’s transition from the space of Retzius (SOR) to ectopic reservoir placement. Lockout Valve
In 2000, Mentor Corporation (Santa Barbara, CA, USA), now Coloplast Corporation (Minneapolis, MN, USA) added an enhanced reservoir with a lockout valve to their line of IPPs. The lock-out mechanism contains a “poppet” valve that does not allow fluid to exit when pressure is applied to the reservoir [4]. Specifically, the lock-out valve works by responding to fluid pressure changes in the tubing to the prosthesis and not to pressure from the reservoir. During cylinder deflation, the valve opens to positive pressure in the tubing. During cylinder inflation, when the collapsed bulb recovers, negative pressure opens the valve (Figure 1). Therefore, negative pres-
sure must be created from the pump side to allow fluid to flow from the reservoir, and furthermore elevated reservoir pressure does not result in fluid flow into the cylinders. In contrast to Coloplast, AMS introduced the MS pump with a lock out valve in the pump itself in 2006. Dr. Wilson et al. published their experience with the Mentor Alpha-1 penile prosthesis with reservoir lock-out valve in 2002 [4]. From January 1, 1998 until April 1, 2001, 499 patients received an Alpha-1 penile prosthesis. All implants were placed via a high scrotal incision by a single surgical team. The standard nonlock-out reservoir was used in 284 virgin implants and 55 revision replacement implants. The newer lock-out valve reservoir was used in 114 virgin implants and 46 revisions. Of note, eight patients underwent ectopic reservoir placement between the anterior abdominal wall musculature and the transversalis fascia due to the obliterated retropubic space. In the immediate postoperative period, each patient in the lock-out valve group was specifically asked about experience with auto-inflation and additionally the penis was examined for evidence of auto-inflation. In the group with standard reservoir placement, early auto-inflation was recorded as a complaint in 37 patients (11%). In 20 cases the problem resolved and in 11 patients the problem persisted but was not considered bothersome enough to indicate additional surgery. Six patients (2%) elected capsulotomy to correct the problem. Of the eight lock-out valve implants placed ectopically, none of these patients reported autoinflation despite the theoretical higher pressure exerted in the submuscular space. No revision surgeries were performed for mechanical failure, infection, or patient dissatisfaction [4]. Although the Mentor Alpha-1 lock-out valve is certainly an example of keen mechanical engineering, the most noteworthy contribution of this article is the utilization of an ectopically placed lock-out valve reservoir in a subset of patients with an obliterated retropubic space. This landmark article could not have been timelier as it was published on the precipice of the robotic surgery revolution in which the standard retropubic approach to radical prostatectomy has been nearly abandoned for the intraperitoneal robot-assisted laparoscopic prostatectomy. Reservoir Placement Locations
Several different approaches for placement of the IPP have been reported, including penoscrotal, J Sex Med 2015;12(suppl 7):464–467
466 infrapubic, suprapubic, and perineal locations, each with advantages and disadvantages. The penoscrotal approach is the most commonly used, with rates of 80% [3,5]. Traditional reservoir placement is in the SOR, which is in close proximity to the iliac vein and bladder. In an effort to avoid the time and morbidity of a second incision, Wilson et al. described ectopic placement of IPP reservoirs in 2002 [4]. This transition would not have been as fluid without the advance of the lockout valve on the reservoir. Dr. Henry et al. recently stressed the perils of traditional reservoir placement based on the anatomical proximity of major structures in the prevesical space [8]. Based on cadaveric measurements, the external inguinal ring was only 2.5– 4 cm from the external iliac vein, 5.3–8 cm from the decompressed bladder, and 2–4 cm from the filled bladder. Due to the proximity of the iliac vessels and the bladder to the space of retzius explains its occasional injury when the reservoir is placed in this location [8]. Previous pelvic surgery alters the surgical planes and makes injury more likely. To minimize the risk of adverse outcomes, alternative sites for abdominal reservoir placement have been described. Alternative reservoir placement sites include: intrabadominal, submusclar, lateral retroperitoneal placement via second incision, subcutaneous placement via second incision, and scrotally after orchiectomy [9,10]. Although serious complications such as vascular, bladder and bowel injuries are rare, they have been associated with retropubic reservoir placement and are disastrous when they occur. In a recent literature review by Ross et al., the most common complication of SOR reservoir placement was erosion of the reservoir into the bladder; which compromised 15/37(41%) of the cases. Presenting with common symptom of bladder erosion was hematuria. Compression of the external iliac vein was also a frequently reported complication noted in 5/37 (14%) cases [3]. Complications from SOR reservoir placement exist even in low risk patients and for this reason, ectopic reservoir placement has gained popularity in recent years. This paradigm shift in reservoir placement would be difficult without the lock-out valve thus preventing autoinflation. Reservoir placement is generally divided into location based on the reservoirs location in relation to the transversalis fascia as described by Stembler et al. [11] Once the transversalis fascia is perforated, the SOR is entered; however, an J Sex Med 2015;12(suppl 7):464–467
Hakky et al. “ectopic” location is commonly coined phrase of reservoir placement between the transversallis fascia and the rectus muscle. Prior to creation of the reservoir space, the bladder is emptied by having the patient void preoperatively or via catheterization intra-operatively. During creation of the space, the pubic tubercle is used as a landmark for guiding the finger into the external inguinal ring. Dissection is then made medial to the external ring and superior to the pubic bone. In patients without any scarring in the SOR due to pelvic surgery, using a finger, scissors, pointed clamp, or nasal speculum can be used to gently perforate transversalis fascia in a downward fashion thus entering the SOR. The reservoir lies behind the pubic bone if performed penoscrotally or more toward the head if an infrapubic approach is utilized [9,11]. In patients where scarring exists in the retroperitoneum the SOR may no be easily accessible resulting in inadvertent intraperitoneal reservoir placement. The most commonly used approach when placing a reservoir ectopically is to create the space for the reservoir without perforating the tranversalis fascia while using a nasal speculum, finger or forceps to perforate the back wall of the inguinal canal, thus creating a space anterior to transversalis fascia but posterior to the muscle layers of the abdomen. A single suture can be preplaced across the ostium of the space to prevent postoperative reservoir displacement during valsalva. This location offers the advantage of reduced risk of injury to intra-abdominal structures but may be more palpable and prone to herniation [9]. In April 2015, Coloplast’s cloverleaf reservoir with lock-out valve received approval from The Center for Devices and Radiological Health of the Food and Drug Administration for changes in labeling instruction for use to incorporate ectopic reservoir placement [12]. This approval is the first of its kind and gives prosthetic surgeons a new, alternative surgical method for men undergoing IPP placement where hitherto all ectopic reservoir placement was done off label. Ectopic Outcomes
Since Dr. Wilson’s publication in 2002, many prominent urologic prosthetic surgeons have documented the safety and efficacy of ectopic reservoir placement in both infrapubic and penoscrotal cases [2,10,11,13]. The importance of alternative placements was highlighted during the Sexual Medicine Society of North America annual
Evolution of the Inflatable Penile Prosthesis Reservoir meeting in 2011. More than 100 registered attendees participated in a poll querying opinions on alternative IPP reservoir placement. Participants reported that IPP reservoirs are either sometimes (46%) or frequently (36%) harder to place in the space of Retzius among robotic-assisted laparoscopic prostatectomy patients and that reservoir placement outside of the space of Retzius is sometimes (54%) or frequently (35%) advantageous for patients’ safety. Respondents agreed (97%) that physician-training courses should specifically include content relating to alternative reservoir placement techniques [10]. Stembler et al. did a retrospective review of 2,687 patients who had ectopic reservoir IPP reservoir placement. Bladder injury occurred in two patients (0.09%), herniation occurred in eight patients (1.4%), and two patients (0.09%) had autoinflation [10]. A potential downside to ectopic placement include reservoir palpability is more likely to occur in slender patients. This occurred in the series in 15 patients (3.4%); however, only two desired corrective surgery [13]. In an effort to decrease the rates of hernia formation and palpability, Dr. Morey introduced a high submuscular approach [13]. Chunge et al. did a retrospective report on their 2-year experience with high submusclar IPP reservoir placement and included a patient questionnaire. Instead of using scissors or a nasal speculum, a Foerster lunggrasping clamp is used to create a submuscular tunnel cephalad to the external inguinal ring through a scrotal incision. Of the 96 patients who underwent IPP placement with high submuscular reservoir placement, the reservoir was nonpalpable by the surgeon 73% of cases. The patients selfreported a satisfaction rate was 96% with only one patient in the series needing to undergo revision surgery for palpability [14]. Conclusions
Penile implants today provide high patient satisfaction with a lower rate of infection and mechanical failure [1]. The pioneering work of Dr. Wilson popularized the lock-out valve and the utility of ectopic reservoir placement. These innovations have been embraced by prosthetic urologists who strive for safe and predictable outcomes. As we witness the continued evolution of the IPP, we need to appreciate the innovative steps that have helped to evolve and improve this surgery. Accordingly, in certain subsets of patients, ectopic/submuscular
467
reservoir site placement should be considered a safe, effective alternative to standard reservoir placement in the space of Retzius. Corresponding Author: Tariq Hakky, MD, MS, Advanced Urology, 1557 Janmar Road, Snellville, GA 30087, USA. Tel: 678-344-8900; Fax: 678-6665201; E-mail: [email protected] Conflict of Interest: The author(s) report no conflicts of interest. References 1 Henry GD. Historical review of penile prosthesis design and surgical techniques: Part 1 of a three-part review series on penile prosthetic surgery. J Sex Med 2009;6:675–81. 2 Levine LA, Hoeh MP. Review of penile prosthetic reservoir: Complications and presentation of a modified reservoir placement technique. J Sex Med 2012;9:2759–69. 3 Simon R, Hakky TS, Henry G, Perito P, Martinez D, Parker J, Carrion RE. Tips and tricks of inflatable penile prosthesis reservoir placement: A case presentation and discussion. J Sex Med 2014;11:1325–33. 4 Wilson SK, Henry GD, Delk JR Jr, Cleves MA. The Mentor Alpha I penile prosthesis with reservoir lock-out valve: Effective prevention of auto-inflation with improved capability for ectopic reservoir placement. J Urol 2002;168:1475–8. 5 Kobayashi K, Hisasue S, Shimizu T, Itoh N, Tsuksamoto T. Erosion of an inflatable penile prosthesis due to autoinflation. J Urol 2004;50:515–7. 6 Abbosh PH, Thom MR, Bullock A. Laparoscopic capsulotomy to treat autoinflation of inflatable penile prostheses. J Sex Med 2012;9:1212–5. 7 Figure 1. (2012). Titan® The Serious Solution [Brochure]. Minneapolis, MN: Coloplast USA. 8 Henry G, Jones L, Carrion R, Bella A, Karpman E, Christine B, Kramer A. Pertinent anatomical measurements of the retropubic space: A guide for inflatable penile prosthesis reservoirs shows that the external iliac vein is much closer than thought. J Sex Med 2014;11:273–8. 9 Perito PE, Wilson SK. Traditional (retroperitoneal) and abdominal wall (ectopic) reservoir placement. J Sex Med 2011;8:656–9. 10 Karpman E, Sadeghi-Nejad H, Henry G, Khera M, Morey AF. Current opinions on alternative reservoir placement for inflatable penile prosthesis among members of the sexual medicine society of North America. J Sex Med 2013;10:2115–20. 11 Stember DS, Garber BB, Perito PE. Outcomes of abdominal wall reservoir placement in inflatable penile prosthesis implantation: A safe and efficacious alternative to the space of retzius. J Sex Med 2014;11:605–12. 12 U.S. Food and Drug Administration, Center for Devices and Radiological Health. FDA PMA supplemental approval. Approval for changes in the labeling of the Titan Inflatable Penile Prosthesis surgical protocol to incorporate ectopic placement. Silver Spring, MD: U.S. Food and Drug Administration; 2015. 13 Morey AF, Cefalu CA, Hudak SJ. High submuscular placement of urologic prosthetic balloons and reservoirs via transscrotal approach. J Sex Med 2013;10:603–10. 14 Chung PH, Morey AF, Tausch TJ, Simhan J, Scott JF. High submuscular placement of urologic prosthetic balloons and reservoirs: 2-year experience and patient-reported outcomes. Urology 2014;84:1535–40.
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