Malfunction and mechanical failure of the inflatable penile prosthesis: a narrative review of etiologies and management

Introduction

Erectile dysfunction (ED) affects nearly 18 million men in the United States alone (1,2) and is projected to affect 322 million men worldwide by 2025 (3) with up to 10.3 million men in the US diagnosed with ED in 2022 (4). Phosphodiesterase 5 (PDE5) inhibitors, intracavernosal injections, and vacuum-assisted devices are successful in some men, others choose or progress to penile prosthesis placement. While medical management is a less invasive and satisfactory method of inducing erections for many individuals, it is not always successful. PDE5 inhibitors, typically the first line of management, have a 30–45% failure rate (5) and immune checkpoint inhibitor (ICI) had 14% failure rate with 14–48% of men discontinuing use (6). Of vacuum-assisted devices, 69% reported continued use after 2 years (7). There is no doubt that conventional and less invasive interventions often provide erections suitable for intercourse; however, the fact remains that many men do not respond to these interventions which necessitate placement of an inflatable penile prosthesis (IPP).

Due to the irreversibility of surgical management and risks of complications, penile prosthetics were reserved for patients with ED refractory to medical management or patients in whom medical management was contraindicated due to comorbidities (8). Complications of prosthetic placement include infection, device malfunction, bleeding, perforation, and even loss of tissue/necrosis. Furthermore, the IPP operation is considered irreversible as natural erectile function is no longer possible due to the damage done to the corpora even if the IPP is removed (9). However, current American Urologic Association (AUA) and European Association of Urology (EAU) guidelines recommend discussing all treatment modalities with patients, regardless of invasiveness, to find the best option for each individual (10,11). As a result, penile prosthetic surgery is now an option for patients with refractory ED or those who do not desire conservative medical therapy. The IPP consists of three components: the reservoir which stores fluid; the pump which controls both inflation and deflation; and the cylinders which reside in the corpora cavernosa and inflate when an erection is desired. Additionally, these components are connected via tubing through which the fluid is transferred between components. These devices allow for both a flaccid and rigid state which more closely resembles the natural physiological state of the male penis in comparison to malleable prosthetics. Two-piece inflatable penile prostheses, which lack the separate reservoir placed in the space of Retzius, also exist. However, for the purposes of this manuscript, the term IPP will be used to refer only to 3-piece inflatable devices. Three-piece IPP devices are durable, with overall IPP survivability as high as 96%, 86%, and 53% at 5-, 10-, and 20-year post-surgery respectively (12). Moreover, these devices are associated with satisfaction rates greater than 90% and are more popular compared to their 2-piece IPP and malleable prosthetic counterparts (1,12).

Yet as a result of this multi-component design, there is a risk for mechanical failure in one or more components of the IPP, requiring surgical correction for proper function. Mechanical failure is reported to account for nearly 50% of all IPP revision surgeries (13,14). Revision is associated with a higher risk of complications, particularly infection, which has been reported to be as high as 18% (15). This is particularly concerning for patients with significant comorbidities such as diabetes whose risk of infection further increases by 2–10-fold during revision surgery compared to virgin implantations (16). For a non-infected malfunctioning device, prosthetic surgeons must decide whether to replace a single component of the device or the entire prosthesis. While theoretically decreasing surgical morbidity and overall cost, concerns of infection with device retention during a partial IPP revision have left surgeons unsure of which approach to use when patients present with a malfunctioning device. In this review, we aimed to evaluate the literature for contemporary rates of mechanical failure. Additionally, we sought to stratify rates of failure by individual components and by manufacturer, identify risk factors for mechanical failure, determine methods for detection of component failure, and evaluate treatment strategies for mechanical malfunction and failure. We present this article in accordance with the Narrative Review reporting checklist (available at https://amj.amegroups.com/article/view/10.21037/amj-23-110/rc).

Methods

A literature review of the IPP was performed. Literature from 1988 to 2023 was included. Searches were performed using PubMed and Google Scholar. Specific keywords included “IPP” “IPP Malfunctions”, “IPP Failures”, “mechanical failure”, “IPP survivorship”, as well as more specific terms based on components (“cylinder failure”, “pump failure”, and “reservoir failure”) or other topics of interest (“IPP infections”, “partial vs. complete revision”, and “IPP Imaging”) (Table 1). Studies were reviewed if: (I) the study was a primary source, (II) the full manuscript was available, (III) the study was available in English, and (IV) the study included devices currently on the market (Table 1).

Mechanical survivorship over time

The first IPP, introduced in 1973 by Dr. Scott, consisted of two non-distensible Dacron-reinforced silicone cylinders each connected by tubing to subcutaneous scrotal pumps and a shared reservoir system (2,17). First manufactured by American Medical Systems (AMS; now Boston Scientific, Marlborough, MA, USA), these devices were prone to cylinder leakage and aneurysms with rates as high as 70% (2,18,19). Since its inception, the AMS IPP has undergone several modifications to improve mechanical reliability over time. From 1974 to 1986 modifications consisted of a single-pump system, a seamless rounded reservoir, expandible cylinders, polytetrafluoroethylene (PTFE) sleeves, kink-resistant tubing (KRT), and rear tip extenders (RTEs) (2). However, devices were still prone to varying rates of mechanical failure with studies reporting 32–40% failure over ~3 years (20) and up to 60% failure over 3–11 years (2,18). In 1987, AMS introduced the CX model which consisted of a 3-ply cylinder design of inner silicone, Dacron-Lycra-woven fabric, and outer silicone to promote controlled and even cylinder expansion. This reduced the rates of aneurysmal dilation and subsequent fluid leakage due to cylinder wall weakening that promoted tearing (21). Later, AMS would produce several different iterations of the CX model in 1990 including: the AMS 700 CXM and AMS Ultrex. The AMS 700 CXM featured the same 3-ply design with an overall smaller diameter of 9.5–14.2 mm compared to the 12–18 mm girth expansion of the CX model. The AMS Ultrex featured a 3-ply design, however, the fabric layer was woven bidirectionally to additionally allow for length expansion by 20% (22). In 2000 and 2001, they would coat their cylinders in a parylene material to improve durability by reducing frictional forces and inhibiZone to reduce infection (2).

The other major competitor of modern IPP’s is the company Coloplast (Minneapolis, MN, USA), formally known as Mentor. Mentor IPP’s were first introduced in 1983 featuring a proprietary material, Bioflex^® (2,21). Made of a polyurethan material, Bioflex^® was thought to be seven times stronger than the silicone materials used in AMS devices without compromising its biocompatibility (2). The first device Mentor device modification, Mentor Alpha 1, was introduced in 1989 as a closed, pre-filled system to reduce risks of connector leakage. However, tube leakages were still a significant cause of mechanical failure, particularly at the proximal component junctions due to wear (2). Then in 1992, Mentor release the enhance Mentor Alpha 1 device with reinforced tubing, improving the device 5-year survival rate from 75.3% to 92.5% (2). Coloplast malleable devices came into the market in 2002 and Mentor was inflatable 3-piece device was quickly acquired in 2006. They released their Coloplast Titan device in 2008 and subsequently continued to make improvements to their Bioflex^® cylinders, pumps, and reservoirs thereafter. Additionally, Coloplast used a hydrophilic coating that decreases bacterial attachment which can bind antibiotics to reduce infection rates (2).

The aforementioned modifications are cited as being the major contributions to reducing overall IPP revision surgeries for both mechanical and non-mechanical complications, decreasing rates to 10–13% (2,18). However, over time, these devices have continued to be optimized with updated pumps, reservoirs, and cylinders to improve ease of use and functional outcomes of the patients who receive them.

The rates of mechanical failure reported in the literature are highly variable and are shown in Table 2. In studies that evaluated the AMS 700 CX model alone, rates vary from 1.9–7.3% (19,20,23-25). However, many studies evaluate mechanical failure by grouping devices (including CX, CXM, Ultrex, LGX, etc.) and manufacturers (AMS vs. Coloplast), and as a result, do not stratify rates by these factors. The overall rates of mechanical failure for AMS devices reported in the literature range from 1.9% to 21.6% (19,20,22-28). Device survivability over time is also quite variable in the literature. For AMS devices alone, rates vary from 91.6–98.2% at 2–3 years (20,23,25,27), 90.0–93.3% at 5–6 years (19,22,25,27-29), and 76.5–81.3% at 10 years (26-28). However, nearly all of these studies include devices from a wide range of years which likely include different device models and updates but fail to identify/describe the number of devices with specific modifications. This may account for some of the variability of mechanical failure reported in the literature. Additionally, nearly all of the studies did not include information on pump design within their cohort, likely due to the majority of failure being related to cylinder and tubing failure.

Risk factors for mechanical failure

Only a handful of studies have attempted to evaluate risk factors for overall IPP revisions, with the majority focused on non-mechanical complications such as infection. A few studies have evaluated the effect Peyronie’s disease (PD) has on overall IPP complications, however, their results are conflicting. DiBlasio et al. (30) retrospectively evaluated the effect of PD on IPP durability and malfunction compared to a non-PD cohort. They found patients with PD have a higher rate of component malfunction and failure than those without PD [33.3% (3/9) vs. 4.3% (3/70), P=0.007]. Additionally, the authors found PD was a predictor of component malfunction and failure in both univariate and multivariate analysis (P=0.002 and P=0.001). Miller et al. more recently attempted to identify risk factors, including PD, for mechanical failure requiring revision surgery in a cohort of 305 patients receiving virgin and revision IPPs. On the contrary to previous evidence, they did not find patients with PD at a higher risk of mechanical failure compared to those without PD in all implants (P=0.71), virgin-only implants (P=0.80), and revision-only implants (P=0.36) (16). One explanation for the differences in findings could be attributed to the smaller percentage of patients with PD in DiBlasio et al. (n=9 with PD, 11%) compared to Miller et al. (n=43 with PD, 16.1%). Another possible explanation could lie in the difference in PD severity. In patients with PD, the curvature of the penis places wall strain on the cylinders which may lead to weakening over time and result in aneurysms or leakage. Additionally, at the time of IPP placement, many patients undergo manual penile modeling to correct the curvature, again placing a large amount of mechanical stress on the cylinders and pump at the time of surgery. Chung et al. previously observed that patients with a >60° curvature or who received concomitant plaque incision were associated with higher rates of mechanical failure compared to those with ≤60° curvature (31). While this association was not statistically significant (P>0.05), the study may have been underpowered. Additionally, the authors reported lower 5-year mechanical reliability rates of 91% for AMS devices and 87% for Coloplast devices (31) for their PD-only cohort compared to other studies (Table 2). Unfortunately, neither DiBlasio et al. or Miller et al. provided information on the severity of penile curvature or the need for concomitant plaque incision procedures in their respective PD cohorts. Thus, the reason for different conclusions about the effect of PD on mechanical failure remains unclear and further investigation is needed.

Miller et al. also reported smoking to be associated with adverse complications (OR 4.14, P<0.01) in patients receiving IPPs. This observation also held true when evaluating the association between smoking and device malfunction (OR 3.14, P=0.04). However, this association for device malfunction was not significant when evaluating virgin-only implants (OR 2.98, P=0.13). Interestingly, smoking was not associated with an increased risk of infectious complications in either the total (P=0.08) or virgin-only cohorts (P=0.21) (16). The relationship between smoking and poor wound healing and/or infection leading to worsened postoperative outcomes is understandable. However, a pathophysiologic mechanism for increased device malfunction and failure is unclear. The authors attempt to address this relationship by stating their cohort had several cylinder erosions and pump migrations which matched that of previous studies evaluating the effect of smoking on postoperative IPP complications (16). Many surgeons would not consider cylinder erosion or pump migration to be a true failure of the implant, but rather related to host factors. This highlights one of the main limitations within the literature regarding loose definitions of device malfunction or failure. Nevertheless, the lack of association with virgin-only implants could suggest a confounding variable, such as the quality of tissue due to scarring in patients receiving revision implants.

Overall, while several loose associations have been made between various risk factors, such as PD and smoking, and mechanical failure, much of the data is limited and of low quality. Other risk factors that have been evaluated include; prostate cancer, diabetes mellitus, hypertension, coronary artery disease, obesity, age, concomitant procedures, prior IPP surgeries, and skin prep (16,30). Interestingly, only a single study, Jorissen et al. (29), evaluated the effect of surgical approach on mechanical failure. This is unsurprising as most studies evaluating mechanical complications perform their IPP surgeries using a single approach (Table 2). Jorissen et al. reported a higher rate of mechanical failure in patients with the infrapubic approach (11.5%) vs. penoscrotal approach (4.0%); however, this association did not reach statistical significance. This again highlights the need for further investigation into risk factors for mechanical failure with larger cohorts.

Differences in mechanical failure location by manufacturer

It is critical to recognize that the majority of studies within the literature primarily focus on the rates of mechanical failure in AMS devices. This is unsurprising due to AMS having the most extensive history dating back to the 1970s while Coloplast Titan was only introduced in the 2000s. However, it should be noted that Garber et al. (32) discussed the reliability of Mentor Alpha I IPP devices in 2003. Out of a 442 patients cohort, 22 devices (5.0%) experienced a known malfunction. Garber stratified malfunctions based on type of placement (scrotal vs. infrapubic). Six failures occurred out of the 154 with infrapubic placement and 16 failures occurred out of the 288 with scrotal placement. There was a total of 1 reservoir failure (1/19, 5.3%), 3 tubing failures at the connection to the cylinders (3/19, 15.8%), and 1 patient did not allow for reoperation (1/19, 5.3%). In patients who had a scrotal placement, 1 patient experienced reservoir failure (1/19, 5.3%), 1 patient experienced pump failure (1/19, 5.3%), 8 had tubing fractures between tubing from the reservoir and pump (8/19, 42.1%), 4 had tubing fractures between tubing and cylinders (4/19, 21.1%), and 2 patients did not allow for reoperation (2/19, 10.5%). However, this device was replaced by the Coloplast Titan devices as previously mentioned. Thus, for the remainder of our discussion, we decided to focus on devices currently being used in prosthetic surgery.

The few studies that included Coloplast devices in their cohorts, Jorissen et al. in 2019 (29) and Miller et al. in 2020 (16), did not evaluate the differences in failure rates of each component between different manufacturers. While similar in design, the inherent property differences in the materials used, specifically in the cylinders, could affect how these devices fail.

Jorissen et al. did report that of their cohort which experienced mechanical failure, 77.8% (7/9) occurred in the AMS devices (29). However, they failed to report what components most commonly failed in AMS vs. Coloplast devices. Chung et al. sought to evaluate mechanical failure in patients randomized to AMS 700 CX and Coloplast Titan devices, however, their cohort consisted only of patients with PD who all received manual penile modeling at the time of implantation (31). In their study, 5% (7/138) of patients required revision surgery for mechanical failure, most commonly cylinder leakage; however, they failed to report if there were other components that malfunctioned. Nevertheless, they found no significant difference in overall implant survivorship in their cohort at 5 years (91% AMS vs. 87% Coloplast, P>0.05).

Smelser and colleagues recently published a study evaluating differences in component failure by location between different manufacturers in patients who received revision surgery for mechanical failure. Overall, the authors reported that tubing failure accounted for 50% (34/68) of all revisions in their total cohort. However, tubing failure was more common in Coloplast devices than AMS devices [86.4% (19/22) vs. 32.6% (15/46), P<0.001]. Tubing fractures, leading to fluid leakage, are one of the most common causes of IPP mechanical malfunction and failure reported in the literature (Table 2). The most significant modification to device tubing occurred in 1986 with the addition of KRT to AMS devices (2). While modern AMS and Coloplast devices use KRT, tubing fractures continue to occur in both devices. Tubing fractures typically occur at two locations, (I) proximal to the pump mechanism at the end of the KRT and (II) at the junction between the tubing and a connector (1,13). Both of these locations are susceptible to acute bending during the manipulation of the devices during inflation and deflation. Additionally, areas where the tubing may rub against one another, such as proximal to the pump mechanism, are more susceptible to fractures due to the silicone weakening over time. Smelser et al. hypothesized that differences in the rates of tube fractures between device brands were likely due to differences in pump design and mechanics which influence ease of use. Coloplast uses Titan Classic and Titan Touch pumps which have been previously cited as being more difficult to deflate compared to the pump in AMS devices due to the differences in the size of the deflation nipple (33,34). User difficulty could potentially result in more torque forces being applied to the tubing possibly leading to an increased rate of tubing fractures (13). However, this hypothesis has not been tested in any studies. Additionally, the authors reported Coloplast devices were more often implanted in younger patients (Coloplast 63.3 years vs. AMS 67 years, P=0.14) and had longer cylinders (median length, Coloplast 20 cm vs. AMS 18 cm, P<0.001). While the demographic variables did not reach statistical significance, the authors suggested younger patients may be associated with a higher risk of IPP revision due to frequency of use (13). Additionally, larger cylinders require an increased number of pumps in order to fully inflate the device. Thus, increased sexual frequency and additional pumps required to inflate the device could result in more frequent torquing and sheering of the tubing, accelerating wear and tear. Nevertheless, as this study is one of few in evaluating component failure by the manufacturer in a small cohort of patients, more research is required to further understand the mechanism of component failure.

Another significant cause of mechanical failure is cylinder leakage. Smelser et al. found that cylinder failure was more common in AMS devices than Coloplast devices [21.7% (10/46) vs. 0% (0/22), P=0.026]. The most significant difference between these device cylinders lies in their inherent material design. AMS devices use a triple-ply design of an inner silicone elastic layer, a middle Dacron-Lycra-woven fabric layer, and an outer silicone layer. The silicone layers also have a parylene coating to reduce wear. In contrast, Coloplast uses a proprietary polyurethane material, Bioflex, which has been reported as having seven times the tensile strength of silicone (2). This difference in tensile strength could account for the differences in cylinder failure between devices.

AMS devices also had higher rates of pump malfunction compared to Coloplast, although this did not reach significance [19.6% (9/46) vs. 4.5% (10/22), P=0.102]. Very rarely, AMS 700 devices (10/306) may develop “Stiction Syndrome”, typically after >6 weeks of inactivity. As a result of static forces between the pin, sealant ring, and valve, the pump becomes locked in the deflate mode. This prevents the transfer of fluid between the reservoir and cylinders (35). This can be resolved by manually deflating the cylinders while holding the deflate button on the pump, however, all patients may not have the dexterity to perform such maneuvers. In patients with a Coloplast implant, a similarly rare (29/550) malfunction was also observed where the pump bulb had very high resistance due to a valve disc being stuck. With Coloplast devices, squeezing the pump bulb firmly resolved the issue (32). While IPP device malfunctions typically require surgical revision, pump malfunctions may sometimes be resolved conservatively.

Overall, Smelser et al. demonstrated AMS devices may typically have a more even distribution of component failure compared to Coloplast devices (13). This highlights how knowledge of the type of implant is critical to predicting what components may have failed when a patient presents with a malfunctioning device. More dedicated research evaluating component failure by the manufacturer is likely needed to further support the study’s findings as their cohort was small (68 total patients) (13). Yet, similar to Chung et al., the authors did not find a significant difference in time to failure (P=0.096) or overall implant survival after 5 years (P>0.05). Thus, both devices are reasonable options, and a device selection should still occur after thorough patient-physician discussions.

Management of malfunctioning IPP: partial vs. complete revision

In most cases, the management of a malfunctioning IPP requires surgical intervention. In the setting of device malfunction, the prosthetic surgeon must decide whether to only revise the malfunctioning component and retain the functioning piece(s) or replace the whole device. Partial-component revision aims to decrease surgical morbidity and cost; however, retaining components that likely contain a biofilm raises concerns over infection risk. Due to the inherent risks associated with the different approaches, the prosthetic surgeon must balance these risks and benefits in each case.

A single-center study investigating infection rates between no component exchange vs. revision with component exchange found no significant difference in infection rates after 12 weeks (P=0.109) (36). This study suggests that exposure, manipulation, and subsequent retention of components are not associated with an increased risk of infection when sterile technique and precautions are used. However, a multicenter, retrospective study found that partial exchange had a significantly higher infection rate compared to complete component exchange (7.1% vs. 2.2%, P=0.031) (37). Although it appears the two studies produce conflicting results, both studies ask fundamentally different questions (36,37). Campbell et al. included both IPP and artificial urinary sphincter (AUS) devices and compared men who had revision surgery without component exchange to those undergoing component exchange. Examples of revision without component exchange include repositioning of high-riding scrotal pumps, herniated reservoirs, or malpositioned cylinders (36). In the series by Barham and colleagues, only IPPs were included and men who experienced pump, reservoir, or cylinder repositioning without component exchange were excluded (37). Based on these differing studies, it appears that there is no increased risk of infection when revising a malpositioned component. However, in the scenario where the malfunctioning component requires replacement, it is beneficial to replace the whole IPP to reduce infection risk. With regards to partial vs. complete component exchange, removal of the original device coated in a biofilm reduces the nidus for infection, thus, potentially decreasing risks of infection.

Additionally, Barham et al. found that the partial exchange group had a significantly higher rate of unspecified device malfunction (3.5% vs. 0.2%, P=0.022), pump malfunction (2.4% vs. 0%, P=0.035), and tubing breakage (2.4% vs. 0%, P=0.035) (37). In a subgroup analysis of the partial exchange group, the highest rate of complications occurred when the pump alone was revised (non-infectious complications 30.4%, infectious complications 13%) (37). This further supports the conclusion that despite the increased invasive nature of a complete revision, it may be associated with reduced morbidity and risk of requiring future interventions due to infection or mechanical complications.

The risk for further interventions after the initial IPP revision is critical because subsequent revisions are associated with increased complications. In a 2018 study of 88 IPP implantations, the rate of infection was found to increase with each IPP replacement. In the individuals with a single IPP placement, 7% had infection (3/44). In individuals with a second (4/22), third (4/12), fourth (4/8), and fifth (2/2) IPP placement, 18%, 33%, 50%, and 100% had infections, respectively (R2 =0.90, P=0.01) (38). It is apparent that an increasing number of IPP revision surgeries increases the risk of infection significantly, thus highlighting the importance of a thoughtful approach to revision surgery to decrease future morbidity.

In patients who undergo IPP revision for mechanical malfunction, prosthetic urologists have considered leaving the previous reservoir in place. Removal of a non-infected reservoir carries risk of bowel, bladder, or major vascular injury (37). Although rare, these can be major life-threatening events. In an effort to reduce these major risks, the idea to “drain and retain” the reservoir has been popularized. However, there is a case report showing late infection of the retained reservoir (39). Cefalu et al. found no difference in infection risk (1.8% vs. 1.5%, P=0.88) and device malfunction (2.6% vs. 0.5%, P=0.15) in patients who retained an IPP or AUS reservoir after revision surgery compared to virgin IPPs (40). Furthermore, Rajpurkar et al. only reported one infection within their cohort of 85 patients who had retained reservoirs after revision surgery, reinforcing that infections with retained reservoirs are rare (41). This suggests the reservoir can be left in place safely while avoiding the serious risk complications associated with component removal.

No studies have directly evaluated time to revision and complication rates in partial component exchange. As demonstrated by Barham et al., urologists tend to perform partial component exchanges earlier compared to complete revision with a mean time to revision of 3.7 vs. 14 years (P<0.01). Yet, while partial revisions occurred sooner, they were still associated with higher postoperative complications, including infection. If time to revision influences the complication rate of partial exchanges, the ideal duration to perform partial revision is unknown. Given this ambiguity, further research is warranted.

Limitations and areas of future research

We are limited by what is available in the current literature and the granularity of that information. Many studies used in this literature did not stratify the IPP device by the specific model, making it difficult to assess reliability improvements in more recent models. Furthermore, the majority of the studies are small series or single surgeon experiences. Additionally, all the current literature is limited by the retrospective nature of the current studies and inherent selection bias of this type of research.

While AMS and Coloplast IPPs remain the predominant devices used today, a new device, Rigicon Infla10, was introduced in 2019 and is currently undergoing FDA safety trials. Like Coloplast, the device features a hydrophilic coating for antimicrobial solution absorption but instead features four-ply reinforced cylinders. The outer silicone layer is coated with a dry lubricant to reduce frictional forces and thus wear damage to the cylinders (42). Earlier this year, Wilson et al. published data suggesting implant survivorship at 2 and 3 years to be 95% and 94% respectively. In their cohort of 535 implants, 19 (3.5%) required revision with 63.2% (12/19) being from mechanical failure (43). The most common source of failure was fluid leakage from the reservoir tubing. This data suggests overall implant survivorship comparable to that of AMS and Coloplast devices discussed in this review. Moreover, similar to Coloplast with its triple-ply reinforced cylinders, tubing failure appears to be the most common cause of mechanical failure in Rigicon devices. Long-term outcome data on this manufacturer is still required but will not be available for some time as these products have only been on the market for a relatively short amount of time. Still, outcome data is promising for its use.

Conclusions

Since its introduction in 1973, the three-piece IPP has undergone numerous modifications to improve device longevity and reduce postoperative infections, particularly within the cylinders. The rates of mechanical malfunction leading to device failure are highly variable with fluid leakage from tubing or cylinder failure being the most common. However, these devices demonstrate excellent mechanical reliability for the first 10 years. The literature lacks high-quality studies evaluating risk factors for mechanical failure with loose associations being made between PD and smoking. Although overall mechanical malfunction rates between manufacturers appear similar, Coloplast devices have higher rates of tubing fracture whereas the distribution is more even among all components for AMS devices. The management of mechanical malfunction should be individualized to decrease morbidity and risks. Complete device replacement is associated with less morbidity than revising only the malfunctioning component. Overall, the quality of data on the incidence and management of IPP mechanical malfunction is limited and further data is needed to better understand the incidence, risk factors, and ideal management.

Acknowledgments

Funding: None.

Footnote

Reporting Checklist: The authors have completed the Narrative Review reporting checklist. Available at https://amj.amegroups.com/article/view/10.21037/amj-23-110/rc

Peer Review File: Available at https://amj.amegroups.com/article/view/10.21037/amj-23-110/prf

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://amj.amegroups.com/article/view/10.21037/amj-23-110/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

References

1. Dinerman BF, Eid JF. Inflatable penile prosthesis malfunction after prostatic urethral lift. Urol Case Rep 2020;33:101384. [Crossref] [PubMed]
2. Pastuszak AW, Lentz AC, Farooq A, et al. Technological Improvements in Three-Piece Inflatable Penile Prosthesis Design over the Past 40 Years. J Sex Med 2015;12:415-21. [Crossref] [PubMed]
3. Ayta IA, McKinlay JB, Krane RJ. The likely worldwide increase in erectile dysfunction between 1995 and 2025 and some possible policy consequences. BJU Int 1999;84:50-6. [Crossref] [PubMed]
4. Rojanasarot S, Williams AO, Edwards N, et al. Quantifying the number of US men with erectile dysfunction who are potential candidates for penile prosthesis implantation. Sex Med 2023;11:qfad010. [Crossref] [PubMed]
5. Moses RA, Anderson RE, Kim J, et al. Erectile dysfunction management after failed phosphodiesterase-5-inhibitor trial: a cost-effectiveness analysis. Transl Androl Urol 2019;8:387-94. [Crossref] [PubMed]
6. Prabhu V, Alukal JP, Laze J, Makarov DV, Lepor H. Long-term satisfaction and predictors of use of intracorporeal injections for post-prostatectomy erectile dysfunction. J Urol 2013;189:238-42. [Crossref] [PubMed]
7. Cookson MS, Nadig PW. Long-term results with vacuum constriction device. J Urol 1993;149:290-4. [Crossref] [PubMed]
8. O'Rourke TK Jr, Erbella A, Zhang Y, et al. Prevention, identification, and management of post-operative penile implant complications of infection, hematoma, and device malfunction. Transl Androl Urol 2017;6:S832-48. [Crossref] [PubMed]
9. Cayetano-Alcaraz AA, Yassin M, Desai A, et al. Penile implant surgery-managing complications. Fac Rev 2021;10:73. [Crossref] [PubMed]
10. Miller LE, Khera M, Bhattacharyya S, et al. Long-Term Survival Rates of Inflatable Penile Prostheses: Systematic Review and Meta-Analysis. Urology 2022;166:6-10. [Crossref] [PubMed]
11. Salonia A, Bettochhi C, Capogrosso P, et al. EAU guidelines on sexual and reproductive health. 2023. Available online: https://d56bochluxqnz.cloudfront.net/documents/pocket-guidelines/EAU-Pocket-on-Sexual-and-Reproductive-Health-2023.pdf
12. Chierigo F, Capogrosso P, Dehò F, et al. Long-Term Follow-Up After Penile Prosthesis Implantation-Survival and Quality of Life Outcomes. J Sex Med 2019;16:1827-33. [Crossref] [PubMed]
13. Smelser AM, VanDyke ME, Nealon SW, et al. Mechanical indications for inflatable penile prosthesis revision: analysis and implications for revision surgery. J Sex Med 2023;20:1044-51. [Crossref] [PubMed]
14. Chan EP, Punjani N, Campbell JD, et al. Indications for Penile Prosthesis Revision: Lessons Learned to Limit Technical Causes of Reoperation. J Sex Med 2019;16:1444-50. [Crossref] [PubMed]
15. Lotan Y, Roehrborn CG, McConnell JD, et al. Factors influencing the outcomes of penile prosthesis surgery at a teaching institution. Urology 2003;62:918-21. [Crossref] [PubMed]
16. Miller JA, Bennett NE Jr. Comparing Risk Factors for Adverse Outcomes in Virgin Inflatable Penile Prosthesis Implantations and Revisions: A Retrospective Cohort Study. Sex Med 2020;8:388-95. [Crossref] [PubMed]
17. Scott FB, Bradley WE, Timm GW. Management of erectile impotence. Use of implantable inflatable prosthesis. Urology 1973;2:80-2. [Crossref] [PubMed]
18. Wilson SK, Wahman GE, Lange JL. Eleven years of experience with the inflatable penile prosthesis. J Urol 1988;139:951-2. [Crossref] [PubMed]
19. Quesada ET, Light JK. The AMS 700 inflatable penile prosthesis: long-term experience with the controlled expansion cylinders. J Urol 1993;149:46-8. [Crossref] [PubMed]
20. Woodworth BE, Carson CC, Webster GD. Inflatable penile prosthesis: effect of device modification on functional longevity. Urology 1991;38:533-6. [Crossref] [PubMed]
21. Dinerman BF, Telis L, Eid JF. New Advancements in Inflatable Penile Prosthesis. Sex Med Rev 2021;9:507-14. [Crossref] [PubMed]
22. Daitch JA, Angermeier KW, Lakin MM, et al. Long-term mechanical reliability of AMS 700 series inflatable penile prostheses: comparison of CX/CXM and Ultrex cylinders. J Urol 1997;158:1400-2. [Crossref] [PubMed]
23. Knoll LD, Henry G, Culkin D, et al. Physician and patient satisfaction with the new AMS 700 momentary squeeze inflatable penile prosthesis. J Sex Med 2009;6:1773-8. [Crossref] [PubMed]
24. Nickas ME, Kessler R, Kabalin JN. Long-term experience with controlled expansion cylinders in the AMS 700CX inflatable penile prosthesis and comparison with earlier versions of the Scott inflatable penile prosthesis. Urology 1994;44:400-3. [Crossref] [PubMed]
25. Deuk Choi Y, Jin Choi Y, Hwan Kim J, et al. Mechanical reliability of the AMS 700CXM inflatable penile prosthesis for the treatment of male erectile dysfunction. J Urol 2001;165:822-4. [Crossref] [PubMed]
26. Dhar NB, Angermeier KW, Montague DK. Long-term mechanical reliability of AMS 700CX/CXM inflatable penile prosthesis. J Urol 2006;176:2599-601. [Crossref] [PubMed]
27. Kim DS, Yang KM, Chung HJ, et al. AMS 700CX/CXM inflatable penile prosthesis has high mechanical reliability at long-term follow-up. J Sex Med 2010;7:2602-7. [Crossref] [PubMed]
28. Ji YS, Ko YH, Song PH, et al. Long-term survival and patient satisfaction with inflatable penile prosthesis for the treatment of erectile dysfunction. Korean J Urol 2015;56:461-5. [Crossref] [PubMed]
29. Jorissen C, De Bruyna H, Baten E, et al. Clinical Outcome: Patient and Partner Satisfaction after Penile Implant Surgery. Curr Urol 2019;13:94-100. [Crossref] [PubMed]
30. DiBlasio CJ, Kurta JM, Botta S, et al. Peyronie's disease compromises the durability and component-malfunction rates in patients implanted with an inflatable penile prosthesis. BJU Int 2010;106:691-4. [Crossref] [PubMed]
31. Chung E, Solomon M, DeYoung L, et al. Comparison between AMS 700™ CX and Coloplast™ Titan inflatable penile prosthesis for Peyronie's disease treatment and remodeling: clinical outcomes and patient satisfaction. J Sex Med 2013;10:2855-60. [Crossref] [PubMed]
32. Garber BB, Khurgin JL, Stember DS, et al. Pseudo-malfunction of the Coloplast Titan Inflatable Penile Prosthesis One-Touch Release Pump. Urology 2014;84:857-9. [Crossref] [PubMed]
33. Masterson JM, Horodyski L, Patel R, et al. Impact of key pinch strength on patient preference for inflatable penile prosthesis: a prospective study comparing Coloplast™ and AMS™ models. Int J Impot Res 2020;32:113-6. [Crossref] [PubMed]
34. Otero JR, Cruz CR, Gómez BG, et al. Comparison of the patient and partner satisfaction with 700CX and Titan penile prostheses. Asian J Androl 2017;19:321-5. [Crossref] [PubMed]
35. Kavoussi NL, Viers BR, VanDyke ME, Pagliara TJ, Morey AF. "Stiction Syndrome": Non-Operative Management of Patients With Difficult AMS 700 Series Inflation. J Sex Med 2017;14:1079-83. [Crossref] [PubMed]
36. Campbell SP, Kim CJ, Allkanjari A, et al. Infection rates following urologic prosthetic revision without replacement of any device components compared to partial or complete device exchange: a single-center retrospective cohort study. Int J Impot Res 2023;35:725-30. [Crossref] [PubMed]
37. Barham DW, Choi E, Hammad M, et al. Partial Component Exchange of a Non-Infected Inflatable Penile Prosthesis is Associated With a Higher Complication Rate. Urology 2023;174:128-34. [Crossref] [PubMed]
38. Montgomery BD, Lomas DJ, Ziegelmann MJ, et al. Infection risk of undergoing multiple penile prostheses: an analysis of referred patient surgical histories. Int J Impot Res 2018;30:147-52. [Crossref] [PubMed]
39. Hsi RS, Hotaling JM, Spencer ES, et al. Isolated infection of a decommissioned penile prosthesis reservoir with Actinomyces neuii. J Sex Med 2011;8:923-6. [Crossref] [PubMed]
40. Cefalu CA, Deng X, Zhao LC, et al. Safety of the "drain and retain" option for defunctionalized urologic prosthetic balloons and reservoirs during artificial urinary sphincter and inflatable penile prosthesis revision surgery: 5-year experience. Urology 2013;82:1436-9. [Crossref] [PubMed]
41. Rajpurkar A, Bianco FF Jr, Al-Omar O, et al. Fate of the retained reservoir after replacement of 3-piece penile prosthesis. J Urol 2004;172:664-6. [Crossref] [PubMed]
42. Wilson SK, Wen L, Rossello M, et al. Initial safety outcomes for the Rigicon Infla10® inflatable penile prosthesis. BJU Int 2023;131:729-33. [Crossref] [PubMed]
43. Wilson SK, Haxhimolla H, Kua B, et al. Survival From Revision Surgery for New Rigicon Infla10 Three-piece Inflatable Penile Prosthesis Is Comparable to Preceding Devices. Urology 2023;180:257-61. [Crossref] [PubMed]