AMS 700™ LGX

What Is the AMS 700 LGX?

The AMS 700 LGX is a 3-piece inflatable penile prosthesis manufactured by Boston Scientific.

It is used for men with erectile dysfunction who have selected penile prosthesis implantation after appropriate assessment and counselling.

The implant is completely internal.

It consists of two inflatable cylinders positioned within the corpora cavernosa, a pump positioned within the scrotum and a separate fluid reservoir placed within the pelvis or lower abdominal region.

The patient manually controls inflation and deflation.

What Does LGX Mean?

LGX identifies the AMS 700 cylinder model designed to provide controlled expansion in both length and girth.

This is the principal feature separating LGX from AMS 700 CX.

CX primarily provides circumferential expansion and axial rigidity.

LGX adds longitudinal cylinder expansion during inflation.

This does not mean LGX automatically produces a predetermined increase in external penile length after implantation.

The patient's corporal anatomy remains the limiting factor.

How the AMS 700 LGX Works

The prosthesis creates rigidity hydraulically.

When the patient repeatedly squeezes the scrotal pump, fluid moves from the separate reservoir into the paired intracavernosal cylinders.

As the cylinders fill, they increase in circumference and rigidity.

LGX cylinders can also elongate as inflation progresses.

After intercourse, the patient activates the deflation mechanism.

Fluid returns to the reservoir and the cylinders become softer.

The penis can then be positioned more comfortably beneath clothing.

Three-Piece Design

AMS 700 LGX has three principal functional components.

The first component is the paired inflatable cylinders.

The second is the scrotal pump.

The third is the separate hydraulic reservoir.

Tubing connects these components into a closed fluid circuit.

This architecture allows substantial fluid to leave the cylinders during deflation, producing a greater difference between erect and resting states than is possible with a continuously semi-rigid implant.

Length Expansion

Longitudinal expansion is the defining feature of LGX.

The cylinder structure allows controlled elongation as the prosthesis is inflated.

Laboratory testing comparing several major inflatable prostheses found measurable longitudinal expansion in the LGX cylinder that was not observed to the same extent in the other tested standard cylinders.

However, cylinder elongation must not be confused with guaranteed external penile enlargement.

The tunica albuginea, corporal fibrosis, scar tissue, previous surgery and baseline penile anatomy determine how much expansion can actually occur in an individual patient.

Girth Expansion

LGX also expands circumferentially.

As hydraulic fluid enters the cylinders, their diameter increases.

This creates both rigidity and increased shaft support.

The device therefore combines circumferential expansion with its longitudinal-expansion characteristic.

The amount of visible postoperative girth varies according to anatomy, cylinder sizing and surrounding tissue.

Does LGX Increase Penile Length?

LGX can support length preservation and controlled expansion, but it should not be marketed as guaranteed penile-lengthening surgery.

One prospective study reported a mean increase of approximately 1.3 cm in fully inflated penile length between baseline and 12 months after implantation.

Another larger clinical series found increased stretched penile length during follow-up.

However, another prospective investigation found that only a minority of patients maintained their preoperative stretched penile length after implantation.

These apparently different findings demonstrate why patient counselling should emphasize preservation and expansion capability rather than guaranteed length gain.

Length Preservation After Implantation

Penile shortening is one of the major concerns expressed by men considering penile prosthesis surgery.

Longstanding erectile dysfunction, radical prostatectomy, Peyronie's disease and corporal fibrosis can all reduce penile dimensions before an implant is inserted.

LGX was developed partly to address this concern by allowing longitudinal cylinder expansion during inflation.

Clinical studies suggest that regular postoperative cycling may allow progressive tissue accommodation in appropriately selected patients.

This should be understood as rehabilitation within anatomical limits rather than a cosmetic enlargement process.

Postoperative Cycling

Once surgical healing is sufficient, patients are commonly instructed to begin regular inflation and deflation exercises according to their surgeon's protocol.

Cycling repeatedly expands the cylinders within the corpora.

With LGX, this may allow the longitudinal expansion capability of the cylinders to interact gradually with compliant corporal tissue.

The timing and intensity of cycling vary by surgeon and individual healing.

Patients should follow their own postoperative instructions rather than adopting an unsupervised aggressive inflation regimen.

AMS 700 LGX vs AMS 700 CX

The principal difference is cylinder expansion.

LGX is designed for controlled length and girth expansion.

CX primarily provides controlled girth expansion and strong axial rigidity.

Neither model is universally superior.

LGX may be particularly attractive when preservation of penile dimensions is a major concern and corporal anatomy can accommodate longitudinal expansion.

CX may be selected when rigidity or management of significant curvature is prioritized.

The final decision depends on anatomy and surgeon judgment.

AMS 700 LGX vs AMS 700 CXR

CXR is the narrower AMS 700 cylinder configuration.

It is intended for patients whose corpora cannot safely accommodate standard-diameter cylinders because of fibrosis or restricted anatomy.

LGX has a different purpose.

Its defining feature is longitudinal and circumferential expansion.

Patients with severe corporal fibrosis may therefore be anatomically unsuitable for LGX even if they would prefer its expansion characteristics.

AMS 700 LGX vs Coloplast Titan

LGX and Coloplast Titan are both 3-piece inflatable penile prostheses.

Their expansion behavior differs.

LGX is specifically engineered to expand in length and girth.

Titan is primarily characterized by girth expansion and strong axial rigidity.

Laboratory testing has demonstrated measurable differences in length change, girth and rigidity between these systems.

The clinical significance of those bench differences varies from patient to patient.

Neither device has been shown to be universally superior.

AMS 700 LGX vs Rigicon Infla10 AX

Both AMS 700 LGX and Rigicon Infla10 AX are designed for dual expansion.

Both provide longitudinal and circumferential expansion.

AMS 700 LGX has a much longer history of clinical use and a more mature published evidence base.

Infla10 AX is a newer system with contemporary pump, reservoir and coating technologies but shorter long-term follow-up.

There is currently insufficient high-quality independent evidence to declare one universally superior.

AMS 700 LGX vs AMS Ambicor

LGX is a 3-piece prosthesis with a separate reservoir.

Ambicor is a 2-piece prosthesis with fluid-storage chambers integrated into the cylinder system.

LGX provides dedicated longitudinal and circumferential expansion.

Ambicor does not use a dedicated length-expanding cylinder design.

Ambicor may be useful when avoiding placement of a separate abdominal or pelvic reservoir is particularly desirable.

LGX may offer greater expansion flexibility and a larger difference between inflated and deflated states.

LGX and Penile Rigidity

LGX provides hydraulic rigidity adequate for penetrative intercourse.

Its design balances rigidity with the ability to expand longitudinally and circumferentially.

Some other prosthesis models may demonstrate greater rigidity under specific laboratory loading conditions.

This does not mean LGX lacks clinically effective rigidity.

Real-world function depends on cylinder size, inflation pressure, corporal anatomy and patient use.

InhibiZone™ Antibiotic Treatment

Current AMS 700 LGX configurations are available with InhibiZone antibiotic treatment.

InhibiZone incorporates rifampin and minocycline into the device surface.

This technology is designed to reduce bacterial colonization around the implant.

It differs from hydrophilic prosthesis coatings that absorb an antimicrobial solution chosen during surgical preparation.

No antibiotic treatment completely eliminates infection risk.

Non-InhibiZone Configurations

Boston Scientific also lists non-InhibiZone LGX configurations.

This is important for patients with medication-related considerations and for markets where different configurations are supplied.

The CMS should therefore state that InhibiZone is available rather than implying that every LGX manufactured worldwide necessarily contains the same antibiotic treatment.

Current Cylinder Lengths

Boston Scientific currently lists AMS 700 LGX cylinders in:

12 cm

15 cm

18 cm

21 cm

These configurations are available in current ordering information.

Rear-tip extenders can be added when necessary to achieve the measured corporal length.

Rear-Tip Extenders

Rear-tip extenders are placed at the proximal end of the cylinders.

They help match the prosthesis to the patient's measured corporal length.

The surgeon chooses the cylinder and extender combination after intraoperative measurement.

Rear-tip extenders should not be used to artificially increase external penile length.

Correct sizing is necessary to avoid excessive pressure, pain and erosion.

Scrotal Pump

The AMS 700 system uses a pump implanted within the scrotum.

The patient manually locates the pump through the skin.

Repeated compression transfers fluid from the reservoir into the cylinders.

The deflation control allows fluid to return to the reservoir.

Patients therefore require sufficient hand dexterity to use the prosthesis effectively.

Separate Reservoir

LGX uses a separate fluid reservoir positioned within a suitable pelvic or abdominal location.

This reservoir stores the majority of the hydraulic fluid when the implant is deflated.

Because the reservoir is separate, the cylinders can become relatively soft after deflation.

Previous pelvic surgery may require alternative reservoir placement.

Modern ectopic reservoir techniques allow many post-prostatectomy and other pelvic-surgery patients to receive a 3-piece implant safely.

AMS 700 LGX After Radical Prostatectomy

Persistent erectile dysfunction after radical prostatectomy is a common indication for penile prosthesis implantation.

Some patients also report reduced penile length following prostatectomy.

LGX may be attractive in this setting because of its longitudinal expansion capability.

However, it cannot reverse all shortening caused by tissue fibrosis, anatomical changes or loss of erectile tissue compliance.

Patients should be counselled according to their preoperative dimensions rather than promised restoration to a previous historical length.

LGX and Peyronie's Disease

Men with Peyronie's disease and severe erectile dysfunction may be treated with an inflatable penile prosthesis.

LGX may be appropriate in selected cases, particularly when preserving penile dimensions is a priority.

However, severe curvature or fibrosis can reduce the ability of the corpora to accommodate longitudinal expansion.

Patients requiring aggressive modeling or reconstructive straightening may be better suited to a different cylinder configuration depending on anatomy and surgeon preference.

LGX and Corporal Fibrosis

Corporal fibrosis limits tissue compliance.

It may develop following prolonged ischemic priapism, previous prosthesis infection, penile surgery, Peyronie's disease or other corporal injury.

Because LGX depends partly on tissue accommodation for longitudinal expansion, severe fibrosis can reduce the practical value of that feature.

If corporal diameter is substantially restricted, a narrower implant such as AMS 700 CXR may be required.

Mechanical Reliability

LGX has a substantial published reliability record.

A very large database analysis involving more than 55,000 AMS 700 CX and Ultrex/LGX implants compared revision-free survival between the length-and-girth-expanding and girth-expanding cylinder families.

Parylene-coated Ultrex/LGX devices demonstrated approximately 88.7% estimated survival at seven years.

This was statistically similar to approximately 89.5% for CX.

The analysis found no significant difference in seven-year survival between the two expansion designs.

Role of Parylene Coating

Modern AMS 700 cylinders use parylene coating on cylinder wall surfaces.

The coating reduces friction between layers during repeated inflation and deflation.

Large-scale survival analyses found lower revision rates for mechanically enhanced parylene-coated cylinders compared with earlier non-coated designs.

Parylene should not be confused with InhibiZone.

Parylene is related to mechanical durability, while InhibiZone is an antibiotic treatment.

Large Clinical LGX Series

A 342-patient single-surgeon study of AMS 700 LGX recipients reported one infection and ten mechanical failures during follow-up.

The same study found increases in mean stretched penile length at 3, 6 and 12 months.

These outcomes support the clinical functionality of LGX but represent shorter follow-up than the large device-survival database.

Reliability Should Not Be Interpreted as Device Lifespan

An 88.7% seven-year revision-free survival figure does not mean an LGX implant lasts exactly seven years.

Many implants function substantially longer.

Others may require revision earlier because of mechanical failure, infection, erosion or another complication.

Device-survival statistics describe populations rather than predicting the lifespan of one patient's prosthesis.

Mechanical Failure

Potential mechanical failures involve cylinders, pump, tubing, connectors, reservoir or hydraulic fluid loss.

Typical symptoms include inability to achieve normal rigidity, progressive loss of inflation, pump malfunction or difficulty deflating.

Confirmed mechanical failure generally requires surgical revision.

Depending on device age and findings, the surgeon may replace one component or the entire prosthesis.

Infection

Infection remains one of the most serious complications of penile prosthesis surgery.

InhibiZone contributes to infection-prevention strategy but does not make infection impossible.

Risk is also influenced by diabetes control, previous implant surgery, active infection, tissue quality and operative factors.

Deep prosthetic infection can require device removal or salvage surgery.

Erosion

A cylinder can rarely erode through corporal, urethral or distal penile tissues.

Risk can be increased by infection, tissue damage, reduced sensation, fibrosis, previous implant surgery or inappropriate cylinder sizing.

Persistent pain, visible components or abnormal urinary symptoms require specialist assessment.

Concealability

Because the LGX uses a separate reservoir, fluid can leave the cylinders when the implant is deflated.

The penis becomes substantially softer than with a malleable implant.

This generally allows good concealment under clothing.

Actual resting appearance varies with anatomy, cylinder size, scar tissue and healing.

Sensation and Orgasm

AMS 700 LGX primarily restores penile rigidity.

It does not directly restore sexual desire, penile sensation or orgasm.

Patients who retain normal sensory pathways and orgasmic function before implantation generally retain these functions afterward.

Men who have lost ejaculation because of radical prostatectomy will not regain ejaculation simply because a penile implant is inserted.

Does LGX Restore a Natural Erection?

No penile prosthesis restores the natural vascular erectile mechanism.

LGX creates rigidity mechanically by transferring fluid into implanted cylinders.

The resulting erection is controlled by the patient rather than occurring through normal arterial filling.

The benefit is that reliable rigidity can be achieved even when vascular or neurological erectile mechanisms are severely impaired.

Revision Surgery

LGX can be replaced if mechanical failure, infection, erosion or another serious prosthetic problem develops.

Revision surgery can be more complex than primary implantation because scar tissue forms around prosthetic components.

Repeated operations may also increase corporal fibrosis.

Patients should therefore understand that penile implantation is a long-term prosthetic treatment that may eventually require additional surgery.

Who May Be a Good Candidate for AMS 700 LGX?

LGX may be particularly suitable for men with severe erectile dysfunction who want a 3-piece inflatable prosthesis and place importance on preserving penile dimensions.

It may also be relevant after prostatectomy when shortening is an important concern.

Patients should have sufficient corporal tissue compliance to benefit from longitudinal expansion.

They must also be able to operate a scrotal pump.

Final suitability depends on anatomy, fibrosis, curvature, previous surgery and surgeon assessment.

What Should Patients Weigh Before Choosing AMS 700 LGX?

The principal strength of LGX is its combination of hydraulic rigidity with controlled length and girth expansion.

Its long clinical history and substantial evidence base are additional advantages.

The main trade-offs include the mechanical complexity of a 3-piece system, reservoir placement, pump operation and the possibility of future revision.

Most importantly, its length-expansion feature should not create unrealistic expectations.

The goal is restoration of reliable erections with the potential for controlled dimensional expansion within the limits of the patient's anatomy.