Priapus Shot® Procedure
The Priapus Shot® procedure indicates a specific protocol for treating the penis with blood-derived growth factors: specifically platelet-rich plasma or PRP. The name Priapus Shot® is registered with the US Patent & Trademark office as a “service mark” to protect patients by indicating a specific protocol. The name is not a synonym for the injection of blood in to the penis—such a definition would not be specific enough to warrant protection as intellectual property and so would not indicate any particular quality of care.
The trademark gives a method of teaching a specific protocol that providers agree to follow and develop; this agreement offers a measure of quality control and is being followed and developed by around 500 urologists and interventional radiologists, family practitioners, and internists in multiple countries and by faculty in several medical schools where further studies are being done.
The Priapus Shot® procedure defines a protocol that involves patient selection, patient evaluation & education (including explanation of consent), preparation of the PRP, local anesthesia, PRP injection, post injection use of a penis pump on a daily basis, and (in some men) a daily dose of Tadalafil. Other post injection steps can include: stopping smoking, CoQ10 (12), vitamin E (13), Trimix, and aerobic exercise. Protocol steps vary depending on the problems presented by the patient.
It is the policy of most of our providers of the procedure to offer any patient that is not happy with the Priapus Shot® procedure a complete refund or a repeat procedure.
Patient selection includes identifying those who may need hormonal treatment, or family counseling, or vascular surgery, as well as those who may have co-morbidity or who may be taking drugs that interfere with sexual function. Some patients are not treated with the Priapus Shot® protocol because another treatment or no treatment is more appropriate.
Consulting the patient includes informing him that unexpected side effects could occur and the results can vary with some patients seeing no benefit.
The preparation of the PRP involves a device approved by the FDA for isolating PRP from whole blood for autologous use. Since blood is not a drug, it is not governed by the FDA. Multiple kits have gained FDA approval. Some of the approved kits include Regen, Magellan, TruPRP, Eclipse, Pure Spin, Selphyl, & Emcyte. There are over 8,000 papers on pub med discussing the science of PRP, and not one serious side effect has been documented when FDA approved kits were used to prepare the PRP.
The first indication that PRP may be useful in the penis is in a paper published in Urology in 2003 indicating that, in animal models, using growth factors was successful to treat erectile dysfunction and indicated that such a strategy may be feasible in men— actually providing a way to correct underlying pathology (1). Viagra and Trimix do not correct underlying pathology of penile circulation.
Another animal model study in 2010 showed that transferring adipocyte derived stem cells (ADSCs) into the penis caused endothelia cell growth as well as increased nitric oxide activity in the dorsal nerve. Interestingly, the ADSCs were tagged and perished - so the improvement seen was not from maturation of the ADSCs but rather from recruitment and activation by growth factors of stem cells from within the body. Also, indicating the PRP may demonstrate a similar effect (2).
Dr. Virag (also a pioneer of Trimix injections) published a paper demonstrating improvement in erectile function, size, and correction of Peyronie’s disease with the use of PRP. His studies both published (and to be published) demonstrate a mean increase of 7 on the ED Intensity Score when PRP is injected into the plaque and the corpus cavernosum of the human penis (3).
One of the growth factors (over 20 known) found in PRP includes vascular endothelial growth factor (VEGF). In one animal model study, the animals were castrated to create a penis that demonstrated, on microscopy, atrophy of smooth muscle and nerves as well as endothelial cell pathology. Injecting VEGF directly into the corpus cavernosum prevented the atrophy as effectively as did testosterone replacement. Moreover, VEGF reversed cavernosoetric findings of leakage (4).
The above studies and others not cited indicate an improvement in the health, circulation, and strength (density) of penile tissue.
In regards to improvement in erection firmness, the Priapus Shot® protocol also includes a recommendation of aerobic exercise which by metaanalysis of 5 randomized controlled studies using the IIEF showed an increase of 5 (5,6).
As previously stated, the complete Priapus Shot® protocol, also includes the use of a penis pump, which as a stand-alone therapy has been demonstrated to improve erection both as part of a penile rehabilitation program as well as an adjunct to other therapies (7,8).
This same penis pump strategy, even without the PRP, has been demonstrated to increase penis size by 2-3 cm, while traction (another physical therapy that can be included as part of the Priapus Shot® protocol) was shown to increase penis length by 1.5-2.5 cm (8, 9). Adding PRP to the protocol shows improved results according to data collected by urologists currently utilizing the Priapus Shot® protocol - to be presented later this year. It should be noted that the 2.5 cm improvement seen with the penis pump alone is in the 10-20% growth range for the average sized penis. As previously stated, while patient results vary, any patients that are not happy with the procedure are given a complete refund.
Ultrasound studies of humans, post treatment, by Dr. Virag and by the physicians currently utilizing the Priapus Shot® protocol demonstrate improved blood flow and an increase in endothelium (improved health) as well as such results being indicated animal model studies, only some of which have been cited.
Dr. Virag’s studies, using the injection of PRP as a stand-alone (without physical therapies), also demonstrate improvement in the angle of the penis in men suffering with Peyronie’s disease (3). Also, strict adherence to a penis pump regimen is part of the Priapus Shot® protocol and the pump alone improves the angle significantly in over one-half of those studied in one study in the British Journal of Urology (10). This same study demonstrated growth of the penis using the pump alone (without the PRP injection) though the growth was not as significant as in the other studies previously cited. The PRP alone, in Dr Virag’s study, out-performed the pump with demonstration of remodeling of the plaque.
Studies show that the non-surgical treatment of Peyronie’s is most effective when a synergy of multiple modalities is engaged (11). So, the Priapus Shot® procedure includes the injection of PRP (demonstrated effective by Dr. Virag) combined with daily physical therapy using a penis pump for ten minutes twice a day and a daily low-dose of Taladafil. Further, other modalities are also used in the Priapus Shot® procedure that have been demonstrated to be synergistic: stopping smoking, CoQ10 (12), vitamin E (13), Trimix, and aerobic exercise. Such strategies are not intended to take the place of surgical correction or of the use of chemical surgery with collagenase—but rather to offer the man suffering with Peyronie’s disease the optimal non-surgical treatment as a first step with surgery reserved if non-surgical therapies fail.
The Priapus Shot® protocol does not intend to make any particular therapy obsolete but rather offer a protocol for enhancing an overall, synergistic approach to pathology of the penis. The surgical treatment of Peyronie’s disease can be unsatisfying and lead to serious complications (14); we are seeing the safety profile of PRP and the Priapus Shot® protocol offer an appealing conservative step to take before proceeding to surgery.
For, example the penis pump alone (part of the Priapus Shot® protocol) has been shown to improve the effectiveness of Cialis and of Trimix injections (8). We are seeing men decrease the dosage of Viagra and/or Trimix by about 50 percent when the complete Priapus Shot® protocol is used.
Most men find the procedure very comfortable if a topical lidocaine cream is used since a 1/2 inch 30 gauge needle is used for injection (similar to a Trimix injection). However, some men do ask for a dorsal nerve block which can easily be done using 1% lidocaine without epinephrine for a near painless procedure (since this same block can be used for prosthesis placement, it makes a 30 gauge needle completely painless for most men) (15).
Considering the duration of effectiveness and risks involved it’s useful to consider the nature of the cell biology employed. A review article considering the basic science discusses the fact that the autologous growth factors are exactly what’s generated to propagate healing should the man have surgery. The healing peptides, chemotactic factors, and pluripotent stem cells employed are exactly what’s generated by the normal healing process and offered no inherent risk for infection or allergy (16).
In over 8,000 papers published about PRP on pub med, there is not one serious sequelae reported that I can identify (multiple review article speaks of the safety). This seems logical when you consider the material being injected is autologous and normally produced to help healing and to fight infection.
Wound care studies demonstrate the nature of multiple tissue types being regenerated (with no reported risk of neoplasia in multiple biopsy studies (17-20).
Moreover, in rat studies (where biopsy of the dorsal nerve is feasible), PRP has been shown to help regenerate nerve tissue and restore erectile function when prostate surgery is modeled with crush injury to the dorsal nerve (21,22). Some studies of stem cell therapies demonstrate that the stem cells do not actually mature into healthy tissue but rather signal for the improvement of the involved ganglion and nerve conduction by recruitment of stem cells to the area - exactly what happens with PRP.
Stem cells are not directly prepared as part of the Priapus Shot® procedure, but we are seeing similar results as what’s reported with stem cell studies. Stem Cell studies often use PRP as a carrier for the stem cells, bringing into question which is the active agent (23-24).
The idea of safety is further emphasized by the literature indicating that not only are there no reports of serious allergic reactions to PRP, but research also shows that PRP can attenuate the autoimmune response. One split-scalp study (with placebo control) showed improvement in alopecia areata, with the use of PRP, that out-performed triamcinolone (25). Another study using PRP in the genitalia of women, showed improvement in lichen sclerosus as determined by both patient survey and by 2 blinded dermatopathologists (26). This attribute of PRP, that of attenuation of the autoimmune response, could partly explain the effectiveness of the Priapus Shot® protocol for the treatment of both Peyronie’s disease and erectile dysfunction.
In summary, multiple studies support the idea that blood-derived growth factors (when prepared in a proper way using a kit approved by the FDA for the preparation of PRP), as used in the Priapus Shot® protocol, support the health and function of the penis. Erectile dysfunction is associated with anhedonia, and successful treatment leads to better function, better relationships, and more pleasure in life (27).
2. Garcia MM, Fandel TM, Lin G, Shindel AW, Banie L, LinC-S, and Lue TF. Treatment of erectile dysfunction in the obese type 2 diabetic ZDF rat with adipose tissue-derived stem cells. J Sex Med 2010;7:89–98
3. Virag R. A New Treatment of Lapeyronie’s Disease by Local Injections of Plasma Rich Platelets (PRP) and Hyaluronic Acid. Preliminary Results. e-mémoires de l'Académie Nationale de Chirurgie. 2014;13(3):96-100.
4. Rogers R. Intracavernosal vascular endothelial growth factor (VEGF) injection and adeno-associated virus-mediated VEGF gene therapy prevent and reverse venogenic erectile dysfunction in rats. International Journal of Impotence Research. 2003;15:S24-9.
5. Lamina S, Agbanusi E, Nwacha RC. Effects of Aerobic Exercise in the Management of Erectile Dysfunction: A Meta Analysis Study on Randomized Controlled Trials. Ethiopian Journal of Health Sciences. 2011;21(3):195-201.
6. Esposito K, Giugliano F, Di Palo C, et al. Effect of Lifestyle Changes on Erectile Dysfunction in Obese Men: A Randomized Controlled Trial. JAMA. 2004;291(24):2978-2984. doi:10.1001/jama.291.24.2978.
8. Pahlajani G,Raina R, Jones S, Ali M, and Zippe C. Vacuum erection devices revisited: Its emerging role in the treatment of erectile dysfunction and early penile rehabilitation following prostate cancer therapy. J Sex Med 2012;9:1182–1189.
12. Safarinejad M. Safety and efficacy of coenzyme Q10 supplementation in early chronic Peyronie’s disease: a double-blind, placebo-controlled randomized study. International Journal of Impotence Research. 2010;22(5):298-309.
16. Sanchez-Gonzales J. Platelet-Rich Plasma Peptides: Key for Regeneration. International Journal of Peptides. 2012;10:1-10.
18. Yuan T, Zhang C-Q, Wang JH-C. Augmenting tendon and ligament repair with platelet-rich plasma (PRP). Muscles, Ligaments and Tendons Journal. 2013;3(3):139-149.
20. Conde-Montero, E., Horcajada-Reales, C., Clavo, P., Delgado-Sillero, I. and Suárez-Fernández, R. (2014), Neuropathic ulcers in leprosy treated with intralesional platelet-rich plasma. Int Wound J. doi:10.1111/iwj.12359
24. Fandel T. Recruitment of Intracavernously Injected Adipose-Derived Stem Cells to the Major Pelvic Ganglion Improves Erectile Function in a Rat Model of Cavernous Nerve Injury. European Urology. 2012;61(1):201-210.
26. Goldstein A. ISSVD 2015 Abstracts. Autologous Platelet Rich Plasma (PRP) Intradermal Injections for the Treatment of Vulvar Lichen Sclerosus. Journal of Lower Genital Tract Disease. 2015;19(3):S1-S25.