1 Background

The external genitalia, particularly the scrotum, is situate between the thighs and is usually heavily clad and hidden which confers on it protective shielding from external gunshot assaults [1, 2]. This explains their uncommon occurrence. 10% of all civilian gunshot wounds (GSWs) involves the genitourinary system [3,4]. Of these 2–4% affects the external genitalia [4, 5]. Even more uncommon are GSWs involving the scrotum only. However, rising insecurity and civil violence promotes possession of guns by untrained individuals, concealed in trouser pockets, for self-defence. This makes the genitalia vulnerable to injuries when the trigger is inadvertently pressed and discharged- a case of “self-defence” turned to “self-destruction” or “self-affliction”. The extent of injury is determined by the velocity, structure and integrity of the projectile from the gun, and the distance from the muzzle to the target [6,7,8]. Thus, isolated scrotal gunshot injury scenarios occurring at very close range are predictive of the caliber of the weapons being of low-velocity [9].

Management of penetrating scrotal injuries involves prompt surgical exploration, meticulous debridement and primary repair of injured tissues [6, 7, 10]. The goal is to retain as much viable tissues as possible, in order to preserve androgenic and spermatogenic functions, as well as cosmetic appearance. The American Association for the Surgery of Trauma (AAST) Testicular Injury Scale is a useful guide for peri-operative evaluation, categorization and treatment of these injuries [11].

We describe the presentation and management of two consecutive cases of isolated scroto-testicular injuries caused by accidental discharges from hand-guns stored in trouser pockets of the patients. The involvement of the scrotum and testes only, sparing the penis, at such close range, is unique and rare.

2 Case presentations

2.1 Case summary 1

A 41-year-old man presented with a 2-h history of gunshot injuries to the left hemi-scrotum and left upper thigh. This occurred following an accidental discharge from a gun carried in his right trouser pocket. The bullet pierced through the left hemi-scrotum and got lodged in the left upper thigh, resulting in left hemi-scrotal swelling and bleeding from the wounds. He could bear weight on the left lower limb and walk with support. Pre-morbid status was normal and he’s married with children. On examination, he was fully conscious, alert and hemodynamically stable. Chest, abdomen and pelvis were grossly normal. External genitalia showed a swollen dark colored left hemi-scrotum with entry and exit wounds on its anterior and lateral surfaces. There was tenderness and bleeding from the wounds. The right hemi-scrotum, testis, penis and urethra were all normal. The adjacent left upper thigh disclosed a 2 cm entry wound oozing blood. A diagnosis of scrotal self-inflicted gunshot injury with associated left thigh injury was made. Scrotal ultrasound scan demonstrated preserved integrity of the tunica albuginea and blood flow on the right testis while these were absent on the left. An X-ray of the left thigh showed a bullet lodged in the soft tissues (Fig. 1). He was resuscitated and promptly taken for scrotal exploration, where the major findings included: left hemi-scrotal hematoma, shattered and necrotic testis and epididymis (AAST grade 5 Testicular injury). Left orchidectomy, debridement and primary closure of scrotal wounds, and debridement followed by daily dressings of the thigh wounds, were the procedures carried out. Wounds healed without complications and patient was discharged on the 18th day post-op. At one year follow-up, he was satisfied with his erectile function, and had no plans to have more children.

Fig. 1
figure 1

X-ray left thigh showing radio-opaque bullet in soft tissue

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2.2 Case summary 2

A 51-year-old male security operative presented with a 3 h history of injury to the scrotum, bleeding, pain and associated injury to the left thigh, following an accidental discharge from a shot gun stored in his right trouser pocket. Pre-morbid status was normal and he was married with children. Examination revealed a patient that was conscious, alert with stable vital signs. The external genitalia demonstrated scrotal lacerations with ruptured tunica albuginea and prolapse of seminiferous tubules of both testes. Again, the penis and urethra were spared. There was associated avulsion of skin of upper medial part of the left thigh (Fig. 2a). A diagnosis of Scrotal self-inflicted gunshot injury was made. X-ray of the left thigh showed multiple pellets lodged in the soft tissues, without bony involvement. At exploration and debridement, 40% of the extruded seminiferous tubules were adjudged viable (bilateral AAST grade 4 Testicular Injuries). Primary repair of the testes and scrotum was carried out with good cosmetic appearance (Fig. 2b and c). A month follow-up showed moderate testicular atrophy and patient was satisfied with his erectile function, and had no plans of future child bearing.

Fig. 2
figure 2

a Grade 4 AAST Testicular injuries with extruded seminiferous tubules. b Repaired testes after meticulous debridement c Post-operative repair appearance

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3 Discussion

The external genitalia constitute 1% of the total body surface area and receives relative protective shield from the thighs against external gunshots. When the guns are stored in trouser pockets or waist band, the genitalia become exposed and vulnerable to accidental discharges and such are said to be self-inflicted [5, 6, 12]. This has been attributed to improper handling and use of guns [5]. Genital gunshot wounds are rare and constitutes < 1% of all gunshot injuries [13]. The self-inflicted variety involving only the scrotum and contents can be said to be very rare.

Knowledge of GSW ballistics is vital to proper evaluation and management of these injuries. It has been observed that the extent of the injury is determined by the velocity of the projectile, its structure, integrity and the distance from the gun to the target [6,7,8, 14]. Thus, the higher the velocity, and the closer the target, the more extensive the injury [14,15,16]. Therefore, going by the extent of injuries observed in the two patients, it can be deduced that the guns were of the low velocity caliber (200–300 m/sec).

In standardizing the evaluation of injury severity, the American Association for the Surgery of Trauma (AAST) designed a testis injury scale in 1995 [11]. It is graded from I–V, with grades III, IV, V, representing laceration of the tunica albuginea with < 50% parenchymal loss; major laceration of the tunica albuginea with 50% or greater parenchymal loss; and total testicular destruction or avulsion, respectively. Patient 1 in this report sustained unilateral grade V, while patient 2 sustained bilateral grade IV injuries. The grade V injury involved the left testis similar to that recorded by Obi et al. [12]. Bilateral testicular injuries are rare [6, 17]. Gomez et al. [17] and Sinham et al. [10] in their series of 23 and 97 patients with genital gunshot injuries reported bilateral testicular injuries in 1 and 6 patients, respectively.

The anatomic domiciliation of civilian GSWs of the external genitalia follows no predictable pattern. However, there seems to be a preponderance of scrotal over penile injuries in most series [4, 10, 13, 14, 17,18,19]. Conversely, penile injuries predominate in a few series [20, 21].

The approach to the management of these patients includes brief ample and ballistic history [6,7,8, 17, 21], detailed general and genital examination with a view to determining urgency of surgical intervention [6]. Associated extragenital injuries should be noted and given attention, as injury to major vessels can result in fatality [8]. The commonest associated injury as demonstrated in this report and by most authors is injury to the lower extremity [5, 8, 10, 12, 14, 22]. Our index patients had associated injuries to the left thigh. This is explicable as the guns were stored in the right trouser pockets with the muzzle facing the left thigh. Scrotal ultrasonography is the main investigative modality and is useful in assessing tunical integrity and testicular blood flow in equivocal cases or of a contralateral uninjured testis [6, 11]. The first index patient disclosed these signs on the right testis while the left was adjudged non-viable. Where the seminiferous tubules are extruded from ruptured tunica albuginea, assessment is best carried out on table [6]. In our second patient, scrotal ultrasound scan was unnecessary.

Definitive treatment for penetrating scrotal injuries consists of emergency scrotal exploration, meticulous debridement and primary repair of injured testis and scrotum [6, 10, 13, 14, 17, 23, 24]. The commonest surgical procedure carried out for scrotal GSWs in one series was repair of lacerations of testis or scrotum [13].When this is done, testicular salvage rate of 35%–75% has been recorded by most authors [6, 8, 10, 13, 14, 16, 18, 20]. In this series, out of three (3) testes injured, two (66.7%) were salvaged by primary repair alone. Where the testis is viable but primary approximation, due to deficiency of the tunica albuginea is not feasible, tunica vaginalis graft can be used to interpose the defect and effect a repair [15, 23, 25, 26]. For devitalized, non-viable testes, orchidectomy is the treatment of choice. In one large series, orchidectomy rate of 48% was recorded [10]. This is consistent with orchidectomy rate of 23%–55% in most series [10, 13, 17]. Most orchidectomies carried out for genital GSWs are unilateral [27], and this is exemplified by patient 1 in this report.

4 Conclusion

Genital gunshot wounds can be extensive involving both penis and scrotum or confined to the scrotum only. This is contingent on the velocity and caliber of the weapon. The self-inflicted variety results from improper handling of guns tucked in trouser pockets or waistband and the frequency seems to be rising. Observance of the principles of prompt surgical exploration, careful debridement and primary repair of injured testes and scrotum leads to satisfactory outcomes.