Introduction

Figure 1. Fat injection complication: poor cosmesis (asymmetric atrophy/hyperplasia).

Figure 2. A, B, Penuma erosion.

Figure 3. Hyaluronic acid complication: phimosis.

Figure 4. Hyaluronic acid complication: paraphimosis and poor cosmesis from filler migration.

Throughout history, society has often associated a man’s penis size with notions of masculinity, power, and positive self-esteem.¹ The average man has a flaccid penile length of 9.16 cm with a circumference of 9.31 cm and an erect length of 13.12 cm with a circumference of 11.66 cm.² Approximately 55% of men are satisfied with their penis size,³ however, some men with penile dysmorphophobia (a type of body dysmorphia focused on the penis) may resort to extreme measures to address their girth concerns when they lack access to rational health care providers.⁴ In this article, we aim to distinguish between facts and fiction in elective penile girth enhancement procedures.

Penile Fillers

Potential catastrophic complications of exogenous materials such as liquid silicone, paraffin, Vaseline, oils (motor, baby, cod liver), and other materials injected into the penis for girth enhancement have been reported and their use is not medically advised.^5–11 Silicone for injectable use has been fraught with complications. In some cases, surgical procedures are required for removal of silicone deposits and correction of deformities.^12,13 Finally, there is no formal role or evidence for injection of platelet-rich plasma, stem cells, or other regenerative medical procedures for penile girth enhancement.

The soft tissue filling materials that have received US Food and Drug Administration (FDA) approval for cosmetic purposes since 2004 include polylactic acid, polymethylmethacrylate microspheres, hyaluronic acid (HA), and autologous fat obtained through excision or liposuction.¹⁴ The use of these fillers for penile girth enhancement is considered off-label. Of the 3.4 million soft-tissue filler procedures that were performed in the US in 2020, HA injection stands out as the most popular filler, accounting for an estimated 78% of all injectable dermal fillers.¹⁵

HA is the chief glycosaminoglycan polysaccharide in mammalian extracellular matrix. It is cross-linked ex vivo in a lab in order to prevent or delay resorption by the body.¹⁶ However, highly cross-linked HA increases the risk of local responses, inflammation, edema, and granulomas.¹⁶ HA filler can be reversed by administering hyaluronidase in absence of local infection or allergy to bee stings and/or hyaluronidase. A recent systematic review/meta-analysis demonstrated reasonable durability and safety of penile girth enhancement with HA with up to 18 months of follow-up.¹⁷ Although individual results may vary, HA injections can durably enhance the diameter of the flaccid and erect penis by a reported average of 2.27 ± 1.26 cm at 4 weeks postprocedure.¹⁷ There have been observational reports of debilitating and catastrophic complications of “safer” FDA-approved fillers including fulminant penile infections,¹⁸ severe ulceration, and disfigurement requiring skin grafts or other operative management.^19,20 Due to the anecdotal nature of reports, it is unclear whether improper technique, hygiene, and/or filler material is to blame for each case.

Fat Injection

A single center reviewed 355 cases of cosmetic elongation, enlargement, and combined elongation/enlargement phalloplasty with autologous fat obtained from liposuction. They found significant improvement in resting penile length, stretched length, and circumference. Common complications of autologous fat injection are well documented and include pain, nodular hyperplasia/hypertrophy of fat, fat atrophy, contracture, scars, and hematoma/wound complications.^21,22 Critically, there is a case report of a fatal fat embolism in a 30-year-old man following aesthetic penile surgery involving autologous fat injection for girth enhancement.^23,24 The injection of fat cells into the penis is not safe or reproducibly effective.

The Penuma Implant

The Penuma implant (rebranded as the Himplant) is a tailorable soft silicone sleeve penile implant that has received FDA clearance for its use in the correction of soft tissue deformities.^25,26 However, there are no absolute indications for Penuma. This implant is distinct from implants that treat erectile disfunction as it is anchored distally at the coronal sulcus between Buck’s and dartos fascia and provides no erectile function. Access is via penile inversion either through an infrapubic incision or by a “concealed” lateral scrotal incision near the penoscrotal junction.²⁷

The Penuma implant has been shown to increase the midshaft circumference of the penis postoperatively to an average of 13.4 ± 1.9 cm from a preoperative average of 8.5 ± 1.2 cm (P < .001); regarding flaccid penile length, an increase from 9.1 + 0.7 cm to 11.3 + 0.4 cm was noted before and after implantation (P < .1).²⁵ In the retrospective analysis of the first 400 cases, the authors reported the following complications: 19 (4.8%) seromas, 18 (4.5%) hypertrophic scar formations at incision site, 5 (1.25%) superficial ulcerations penile skin, 4 (1%) hematomas, and 13 (3.2%) wound infections between 5 and 12 months. Device removal occurred in 12 (3%) cases due to 4 infections, 4 implant perforations, 2 suture detachments and resultant mispositioning of implant, 1 implant fracture, and 1 hematoma. Temporary adverse events included 6 cases (1.5%) of temporary loss of glans sensation (recovered 2-3 days post surgery). There were no reports of thrombosis, implant migration, sepsis, venous or arterial injury, urinary bother, penile curvature, or erectile/sexual dysfunction. Other retrospective cohort studies have corroborated initial reports, but no high-quality prospective studies have been published.^28,29

Despite the retrospective cohort series reported above, life-changing irreversible complications and poor patient satisfaction with aesthetic penile girth enhancement implant surgeries are garnering mainstream media attention³⁰ and a class action lawsuit was filed in 2021. Explants can be done via a circumcising incision and degloving, however we recommend a penile inversion approach to best access the distal implant tacking sutures.³¹ Although some authors report good results following explant and penile rehab,^27,29 our group has described a case of significant curvature and penile retraction leading to loss of function (“penile cripple”) following the removal of an infected Penuma implant. This occurred despite close postoperative supervision and penile rehabilitation efforts with tadalafil 5 mg every other day, L-arginine 1000 mg daily, pentoxifylline 400 mg twice a day, and penile stretching and vacuum devices.³¹

Conclusion

HA and soft silicone implants are emerging for penile girth enhancement. Importantly, no devices or techniques for penile girth enhancement have undergone rigorous, prospective, long-term study to ensure their safety over an extended period. Furthermore, patient satisfaction is uncertain, given the lack of validated questionnaires in this population seeking penile girth enhancement. As such, there are no FDA-approved options for penile girth enhancement. Penile girth enhancement should continue to be experimental by default and further scientific evaluation is warranted.