Blood Retention: How Xialla Reduces Venous Outflow

For many men with erectile dysfunction, the difficulty is not achieving an erection but maintaining it. Erections that begin adequately and then fade, or that are lost on changing position, point toward a problem with blood retention rather than blood supply. Xialla is designed for that problem. This article explains the mechanism and the evidence behind it.

Venous leak

An erection depends on blood flowing into the penis and being retained there. During arousal, the cavernosal arteries dilate and the corpora cavernosa fill. As they expand, they compress the draining veins against the tunica albuginea, the fibrous sheath surrounding them. That compression is what holds the blood in place.

When the compression is incomplete, blood drains as quickly as it arrives. Pressure does not build sufficiently, and the erection cannot be sustained. This is venous leak, also called veno-occlusive dysfunction or VOD.

It is a common contributing factor. The perspective article on Xialla published in the International Journal of Impotence Research describes venous leak as an etiological factor contributing to approximately 75% of ED cases, citing Kaba and Pearce.

That wording is worth reading carefully. It means venous leak is present and contributing in around three quarters of cases, not that it is the sole cause in three quarters of cases. Most erectile dysfunction is multifactorial, and a man may have both impaired inflow and impaired retention. The practical implication is not that most men need a constriction device, but that outflow is worth assessing rather than assumed to be intact.

Contributing factors include age-related loss of elasticity in the tunica albuginea, diabetes, Peyronie's disease, pelvic or perineal trauma, prostate surgery, and smoking. For a fuller account, see our guide to venous leak.

Limitations of conventional constriction rings

A constriction ring at the base of the penis slows venous return mechanically, which addresses outflow directly. Conventional rings have two recognized limitations.

They must be tight to occlude, because tightness is the only thing holding them in place. That degree of compression can cause discomfort, numbness, or coldness, and excessive compression can restrict arterial inflow as well as venous outflow.

They can also move during intercourse. A ring that shifts applies varying compression, so occlusion is inconsistent at the point where it is most needed.

How Xialla's anchoring works

Xialla is a soft medical-grade silicone ring with an anchoring system: a loop passes around the scrotum and connects to a band secured to an adhesive pad on the lower back. The band draws the ring rearward and holds it against the body.

Because position is maintained by rearward traction rather than by circumferential tightness, the ring can occlude effectively at lower compression than a conventional ring, and it maintains that compression during movement rather than shifting.

Practical consequences of the design:

• It can be applied to a flaccid or erect penis.
• It can be used alone or alongside a treatment that acts on inflow, such as oral medication, injection, or a vacuum device.
• It can be used with a penile implant, though this should be confirmed with your surgeon.

The same anchoring produces several secondary effects, covered in our overview of Xialla's physiological effects.

The evidence

Xialla is an FDA Class II exempt medical device, classified as an external penile rigidity device.

A clinical evaluation led by Dr. Anthony J. Bella, presented at the World Meeting on Sexual Medicine in 2016, reported enhancement of erectile function in 14 of 21 patients. A subsequent evaluation reported satisfactory treatment salvage in 6 of 11 men with confirmed veno-occlusive dysfunction. Both are described in the perspective article cited above.

These are small evaluations, not randomized controlled trials. The published discussion states that larger multicentre trials are needed to confirm the device's role in ED management, and we agree that this is the accurate characterization of where the evidence currently stands.

We have removed a comparative claim that previously appeared here and elsewhere on this site, stating that Xialla is approximately three times more effective at treating venous leak than conventional constriction rings. That figure was not derived from a controlled comparison, and we should not have presented it as though it were. If a study supporting it is conducted, we will publish the figure with its source, method, and comparator.

Read the published paper: International Journal of Impotence Research, or the PMC version.

Who this is relevant to

The mechanism is relevant to men whose erectile difficulty involves retention: erections that begin and fade, loss of firmness on changing position, or a partial but insufficient response to oral medication.

It is not a treatment for arterial insufficiency, neurological causes, or hormonal causes of ED, and it is not a cure for venous leak. It manages the outflow problem while worn.

If you have not had an evaluation, that is the place to start. A urologist can determine whether inflow, outflow, or both are affected, which determines what is likely to help.

Practical notes

Sizing. The correct size holds position without feeling tight. Too loose and the anchoring will not hold; too tight and it can restrict arterial inflow, which reduces rather than improves the result. Size exchanges are free.

Application. Apply before or after erection, then draw the band rearward to engage the anchoring.

Cleaning. Mild soap and water, following the instructions supplied with the device.

Alongside other measures. Cardiovascular exercise, pelvic floor training, and smoking cessation all support erectile function generally. Discuss combination approaches with your physician, particularly if you take medication for cardiovascular conditions.

Safe use

Observe a maximum of 30 minutes of continuous wear, remove the device before sleeping, and remove it immediately if numbness, coldness, discolouration, or pain occurs.

Men taking anticoagulant or antiplatelet medication, men with sickle cell disease or another bleeding or clotting disorder, and men with reduced penile sensation should consult a physician before use. Reduced sensation is particularly relevant, since it may prevent you from noticing the warning signs above.

References

• Yafi FA, Hammad MAM, Elterman D. Xialla: a novel medical device for addressing erectile dysfunction associated with veno-occlusive dysfunction. Int J Impot Res. 2024;36:551-552. Full text
• Kaba R, Pearce I. Venous leak and erectile dysfunction: an important differential.
• Dean RC, Lue TF. Physiology of Penile Erection and Pathophysiology of Erectile Dysfunction. Urol Clin North Am. 2005.
• Burnett AL, Nehra A, Breau RH, et al. Erectile Dysfunction: AUA Guideline. J Urol. 2018;200(3):633-641.