Peyronie’s Disease (PD) results from scar or “plaque” within the penile tunica albuginea. Symptoms include penile pain, shortening, erectile dysfunction, and curvature.¹ Up to 65% of patients may also have focal erectile girth changes such as indentation (unilateral) or hourglass (circumferential) deformity.² In some instances, this may cause buckling during penetrative sexual intercourse, also known as “hinge effect.”

PD treatments include traction therapy, intralesional injections, and surgical straightening.¹ An increasing number of patients are receiving injections, but there is limited evidence that intralesional therapy improves girth.^3,4 Surgery is a reliable means to correct deformity and is only recommended in the chronic/stable phase, defined by the 2015 AUA PD guidelines panel as symptom duration ≥12 months with stable symptoms for 3-6 months.¹ Several algorithms have been proposed taking underlying erectile dysfunction (ED) into account.⁵ Penile prosthesis with straightening maneuvers is recommended for patients with significant ED. Plication is associated with excellent outcomes for those with maintained erectile function and mild/moderate curvature. With severe curvature and/or severe indentation/hourglass, plaque incision and grafting can correct straightening and improve severe indentation. However, even with careful patient selection and expert technique, there is a significant risk for side effects including ED and permanent sensation change.^1,6 With severe deformity where intercourse is difficult or impossible, some patients will accept this risk profile after appropriate shared decision-making. In contrast, with less severe curvature deformity, the idea that one could be significantly worse off from treatment-related side effects is less appealing.

In 2018, Dr Tom Lue and colleagues published the first report of extratunical grafting (ETG) to correct indentation deformity.⁷ With this approach, a biologic grafting material is sutured outside of the tunica albuginea overlying the area of maximum indentation. The technique was developed to minimize postoperative risks for ED and sensory change. Lue and colleagues used a cadaveric fascia lata graft (Suspend) secured with absorbable sutures to “fill in” the indentation. Plication is performed concurrently for patients with curvature. In their series (n=18), 94% of patients reported feeling “satisfied” or “very satisfied” postoperatively.⁷

ETG has gained popularity among urologists who regularly treat PD. The ideal candidate for ETG has bothersome indentation/hourglass with or without associated mild or moderate penile curvature and adequate erectile function (Figure 1). Patients with severe curvature, indentation with associated buckling (hinge effect), and severe penile shortening may be better served with plaque incision and grafting. Those with underlying ED or significant risk factors should strongly consider penile prosthesis placement.

Figure 1. Example of a candidate for extratunical grafting: a 64-year-old male with 45-degree dorsal/lateral curvature and moderate severity indentation.

Like most new approaches, ETG is an evolving technique. The original series from Dr Lue’s group described using a ventral-longitudinal incision,⁷ which has been suggested for better cosmesis and less sensation change relative to circumcising incision, albeit with limited exposure for complex deformities. Preference/experience and a willingness to perform both approaches as needed are in the best interest of both patient and surgeon (Figure 2, A and B).

Figure 2. Extratunical grafting with or without penile plication can be performed through a ventral midline penile incision (A) or a subcoronal/degloving approach (B).

Figure 3. Extratunical graft (ETG) secured underneath Buck’s fascia (BF) to the tunica albuginea (TA) overlying the point of maximum indentation.

Another consideration is the grafting material. Examples include cadaveric fascia lata, bovine pericardium, porcine dermis, and equine collagen fleece.^7-9 Our preference is to use cadaveric human pericardium (Tutoplast). It is readily available at our institution and is routinely used for plaque incision and grafting procedures. This material can also be “tailored” to the depth of the indentation deformity by folding it over on itself as needed. The graft edges are secured with interrupted 4-0 polydioxanone, a long-active absorbable monofilament suture (Figure 2, B). To date, there are no definitive data comparing grafting materials (similar to grafting with plaque incision/grafting), so surgeon preference and institutional availability drive graft choice.⁶

A third consideration is whether to place the ETG above or below Buck’s fascia. ETG was originally described with the grafting material placed above Buck’s, with the proposed benefit of minimizing the risk for sensation change, particularly with circumferential hourglass deformities where dorsal neurovascular bundle mobilization may be required with incision and grafting.⁷ In the original series, slight hypoesthesia was reported by 12% of patients. A subsequent study from Dr Allen Morey and colleagues reported hypoesthesia in only 1/15 ETG patients at follow-up.⁸ A trade-off with this technique appears to be graft palpability. The graft is sewn in place when the penis is erect, so it may bunch up slightly when flaccid. Fifty percent of patients with >6 months follow-up could feel the graft when the penis was flaccid.⁸ In my early experience, several patients were bothered by this palpability, so in some instances I will place the grafting material directly on top of the tunica albuginea after carefully mobilizing Buck’s fascia (Figure 3). Anecdotally, I find that the grafting material is less palpable this way, though it is a careful balancing act. Patients need to be counseled about theoretical risks for sensation change. However, in experienced hands, the risk for long-term severe sensory changes even with more extensive neurovascular mobilization for plaque incision/grafting is low.¹⁰

A final consideration is whether ETG provides any structural support to the penis in the setting of penile buckling/hinge effect. There are advocates for and against this hypothesis, but ultimately it is unclear whether added tissue bulk outside of the narrowed tunica provides structural reinforcement beyond penile straightening alone.^7-9 Part of the reason for this uncertainty is that we do not know what happens to the grafting material long term after ETG—resorption with deformity recurrence vs tissue ingrowth vs scarring? Longer-term follow-up will provide more clarity.

In summary, ETG is an important addition to our treatment algorithm for men with PD. Longer-term studies are needed to confirm the early published results and help us to refine the technique.