Managing dysfunction after penile fracture

Penile fracture is caused by a blunt trauma to the penis. In most cases, injury to the erect penis  occurs during intercourse when the erect penis slips out of the vagina and is subsequently thrust against the partner’s perineum or pubic bone. In a meta-analysis that 58 studies with 3,213 patients were included it was revealed that sexual intercourse (46%), forced flexion (21%), masturbation (18%) and rolling over (8.2%) were the most causes of penile fracture, respectively [6]. In another meta-analysis, man-on-top and “doggy-style” positions were found as mostly associated positions with penile fracture [7]. Under physiological conditions, intracorporeal pressure increases up to 80-100 mmHg during intercourse [8]. Rupture of the tunica albuginea occurs due to the marked thinning from a resting thickness of 2 mm down to 0.25–0.5 mm on erection together with the associated marked short-term pressure increases (intracavernous pressures exceeding 450 mmHg), which approach or exceed the tunical tensile strength during acute abrupt loading or bending of the penis [9]. It was also shown that structural anomalies, such as fibrosclerosis and inflammatory cellular infi ltration composed of lymphocytes and histiocytes, could alter the mechanical properties of the tunica albuginea, representing a weakening factor of the corpora cavernosa and thus, a predisposing factor for the traumatic rupture of the penis [10]. The fracture is mostly located ventrally on right side and proximal part of the tunica albuginea [11]. This can be explained with the differences of tunica albuginea thickness at specific locations. In an anatomical study, it was shown that the thickness of the tunica measured at the 7, 9 and 11 o’clock positions was 0.8 ± 0.1 mm., 1.2 ± 0.2 mm. and 2.2 ± 0.4 mm, and the stress on the tunica at penetration (breaking point pressure) measured at the 7, 9 and 11 o’clock positions was 1.6 ± 0.2 X 107 N/m2, 3.0 ± 0.3 X 107 N/m2 and 4.5 ± 0.5 X 107 N/m2, respectively [12]. The long-term outcomes of penile fracture include erectile dysfunction (ED), Peyronie’s disease (PD), palpable plaque/nodule and painful erection [3,6]. Aging, >50 years at presentation and bilateral corporal involvement were thought to be the main risk factors for subsequent development of ED [11].

There are some studies examining the underlying mechanism of ED after penile fracture and it was shown that ED could not only be explained simply with the tunical structural differences and disruption resulting cavernosal insufficiency but also arterial insufficiency, site-specific defects on erectile tissue in corpus cavernosum and psychogenic factors.

In penile fracture, a bending of the erected penis as an accident may significantly increase intracavernous pressure, exceeding the tensile strength of tunica albuginea. This consequently results in tunical disruption, which leads to site-specific cavernosal insuffi ciency. A sudden increase in intracavernous pressure may also compromise the penile arterial system.

Furthermore, trauma causes intracorporeal bleeding, which in the long-term may lead to fibrosis and poorly compliant focal areas of erectile tissue [9]. These mechanisms were also supported by a study on penile vascular abnormalities observed long-term after penile fracture. In was revealed that 26.7%, 20% and 6.7% of patients had cavernosal insuffi ciency, arterial insufficiency or mixed vascular disease, respectively, which means 54.3% of patients had penile vascular abnormalities of varying degrees [2].

Penile fracture involves blood extravasation outside of the corpus cavernosum. Microtrauma may lead to bleeding and fi brosis trapped in the subtunical space and between the layers of the tunica albuginea. It may be thought that microhematoma caused by microtrauma may be a precursor lesion for PD.

In one study, three patients without penile fracture who had circumscribed septal lesions containing hematomas on ultrasound were evaluated. The hematoma was aspirated under ultrasound guidance. Two of these patients who underwent early aspiration returned normal erectile function, while the patient who underwent late aspiration showed ED and PD [13]. This may indicate that microhematomas caused by microtraumas following sexual intercourse may lead to PD even without obvious penile fracture.

The widely accepted gold standard management of penile fracture is immediate surgical exploration, and repair of the tunica tear and, eventually, of the associated urethral injury to minimise fibrosis deposition in the cavernosal spaces and, in consequence, to lessen the risk oflong-term complications including ED. In a meta-analysis the long-term outcomes of surgically managed 393 patients and conservatively managed 81 patients with penile fracture were compared. The outcomes of surgically managed patients were signifi cantly better in terms of ED (1.9% vs 22%), PD and/or plaques/nodules (14% vs 23.1%) and painful erection (1.4% vs 5%) [6].

Another important issue is timing of surgical intervention. Classically, it is advocated to perform early intervention to achieve better outcomes. High-quality systematic review on penile fracture management identifi ed 14 articles composed of 438 patients between 2012 and 2017 discussing surgical management of penile fracture with long-term functional outcomes. The timing of surgical repair was recorded (stratifi ed by 48 hours after injury). The authors demonstrated that overall complication rates (ED, voiding symptoms, PD, and urethral stricture) were lower in the early surgical intervention groups relative to the delayed groups [14]. In another systematic review, authors evaluated early vs delayed repair for penile fracture. They found that ED rates were lower in the early vs delayed repair group at <12 months follow-up period. However, thi  difference was no longer signifi cant with follow-up >12 months, suggesting that perhaps the short-term benefi ts of early repair on sexual function dissipate with time. No significant difference was observed in rates of palpable penile plaque between the study groups. Penile pain and PD incidences were signifi cantly lower in the early repair group relative to the delayed repair group [15]. In another systematic review, the authors compared outcomes between early and delayed surgical repair of penile fractures, motivated by the recent published series over the last decade reporting acceptable outcomes with delayed intervention. Articles queried in this study included 12 articles (composed of 512) with only those evaluating early repair (<24 hours) vs delayed repair (>24 hours) of penile fracture. The authors reported that combined rates of postoperative ED, tunical scarring, and PD were 6.6%, 5.4%, and 1.8%, respectively in the early repair group and it was 4.5% for each in the delayed repair group. There was no statistical difference for ED and tunical scarring between the early and delayed groups, although a significantly lower rate of PD occurred in the early repair group [16].

There are two common incision techniquescommonly employed in the repair of penile fracture:
distal circumcising-degloving or vertical penoscrotal. A sub-coronal, distal degloving incision is the most popular reported technique for repairing a penile fracture. The advantage of this incision is that it allows full inspection of the corporal body and can aid in the detection of contralateral corporal body or urethral injuries and facilitate an easier repair. The vertical penoscrotal incision provides direct exposure to the tunica defect by only incising the overlying penile skin. There are no publications that directly compare long-term patient outcomes between the two incision techniques [17].

Which suture material should be used for corporal repair is still under debate. Most investigators favour the use of slow absorbable sutures of strong tensile strength for tunica repair because the use of non-absorbable sutures often results in painful palpable knots [3].

As a conclusion, immediate penile exploration and tunica repair should be the main approach of management. It should be noted that even with surgical intervention for penile fracture, long term complications are possible, including ED and PD. ED can be caused by different underlying mechanisms including cavernosal and/or arterial insufficiency and corporeal fibrosis after penile fracture.

• To learn more, you can attend the lectures on “Genital consequence of pelvic trauma” at EAU25 on Monday, 24 March 10:45 – 12:15 – Purple Area, Room 2