Keywords

9.1 Foreskin Disease: Balanitis and Balanoposthitis

9.1.1 Definition and Epidemiology

Balanitis is an inflammation of the glans penis, fairly common, affecting approximately 3–11% of males during their life time, if the inflammatory process involves even the prepuce the condition is termed balanoposthitis [1, 2]. Balanoposthitis involves both the glans and the foreskin and occurs in approximately 6% of uncircumcised males. Balanoposthitis occurs only in uncircumcised males. Balanitis and posthitis could present infectious and noninfectious etiologies, and they are not age related. Approximately 1 in 30 uncircumcised are affected by balanoposthitis, and phimosis represents a risk factor for this kind of condition. Circumcision has a protective role estimated in a 68% lower prevalence of balanitis than uncircumcised males [1, 2].

9.1.2 Pathophysiology

The most common cause of these condition is related to poor local hygiene, since the moist environment under the penile foreskin promotes the growth of organisms that could be the cause of balanitis. Between the normal flora of the foreskin and glans, Candida albicans is the most common yeast causing infection in certain circumstances especially when the patient has underlying pathological conditions such as diabetes, tumors of the glans and foreskin, immunodeficiency, or changes in the Ph baseline [3]. Other infectious causes of balanitis are sexually transmitted diseases (STDs such as gonorrhea, Chlamydia, herpes virus, human papillomavirus, syphilis, and trichomoniasis), Group B and A beta-hemolytic streptococci, and Gardnerella vaginalis infection [4]. Several skin conditions may also trigger balanitis such as psoriasis. Among noninfectious etiologies of balanitis, there are poor hygiene, chemicals irritants (detergent and spermicides) drug allergies, morbid obesity, allergic reaction, and local traumas [5].

9.1.3 Skin Conditions

Between the skin condition that could cause balanitis is important to highlight circinate balanitis (associated with reactive arthritis and HLA-B27), pseudo-epitheliomatous keratotic and micaceous balanitis and zoon balanitis (the latter three have been linked to skin cancer) [6, 7]. Balanitis xerotica obliterans (BXO) is an infiltrative chronic penile skin condition which is histologically identical to lichen sclerosus (hyperkeratosis, atrophy of the stratum spinosum Malpighii associated with hydropic degeneration of the basal cells associated with inflammatory infiltration of the mild dermis and edema), macroscopically characterized by hardened whitish tissue, and edema at the tip of the penis involving foreskin, glans of the penis, and often even the urethral meatus and urethra, leading to phimosis, strictures, and micturition discomfort. Treatment for BXO includes medical options such as topical steroid and surgical procedures including circumcision [8,9,10].

9.1.4 Clinical Findings and Diagnosis

Penile pain irradiating to the glans, redness, and itchiness are frequent symptoms of balanitis. At physical examination, signs frequently found are tight shiny skin on the glans, redness of the glans penis mucosa, swelling, soreness, and a thick white discharge under the foreskin commonly associated with an unpleasant smell. Painful micturition and phimosis could result in case of severe and chronic inflammation [11].

Essentially balanitis is a clinical diagnosis related to history and physical findings. Additional testing are justified by clinical presentation such as purulent discharge (bacterial culture is indicated), vesicular lesions (herpes simplex virus testing), ulcer (syphilis testing), and urethritis (testing for mycoplasma and trichomonas) [6].

9.1.5 Treatment

The strategy to manage a balanitis is to exclude STI, improve, or achieve a proper hygiene with frequent washing and drying off the prepuce. Topical antifungals are the first-line treatment in patients with balanoposthitis for 1–3 weeks with clotrimazole 1% twice daily or miconazole 1%. Nystatin cream is an alternative in patients allergic to imidazoles. Treatment of the partners of patients with balanitis is recommended. In serious case of inflammation, Fluconazole 150 mg orally should be combined with topical imidazole and low potency steroids. If identified and involvement of subcutaneous tissue, a first generation cephalosporin should be administered. In recurrent episodes of balanoposthitis, especially in diabetic and immunocompromised patients, circumcision is recommended [3, 6, 11].

9.2 Foreskin Disease: Phimosis and Paraphimosis

9.2.1 Definition and Epidemiology

Prepuce, or foreskin, is the skin surrounding the glans penis which is at birth physiologically adherent until the 3–4 years of life (physiologic phimosis). As the penis grows, epithelial debris accumulates under the prepuce and produces a progressive separation between the foreskin and the glans forming the preputial sac. Less than 5% of newborns have a completely retractable prepuce, and this condition progressively changes with growth. At 3 years of life, about 90% of child have a fully retractable foreskin [12]. Phimosis is defined as the condition in which the prepuce cannot be retracted over the glans penis. Phimosis can persist over 3 years of age and in this case may be considered pathological; its incidence among 7-year-olds is 8% and progressively decrease to 1% at 17-year-old boys [13, 14].

9.2.2 Pathophysiology

Risk factors for phimosis are trauma (attempt to retraction), recurrent or chronic balanoposthitis, chronic inflammatory conditions like balanitis xerotica obliterans (BXO), a condition characterized by a sclerotic constricting ring in the distal end of the prepuce associated to edema, causing persistent non-retractability of the foreskin (Fig. 9.1). Its definitive diagnosis is based on histological features: hyperkeratosis with follicular atrophy of the spongiosa with hydropic degeneration of basal cell, band-like chronic inflammatory cell infiltration with homogenization of collagen. BXO has an incidence of 0.6%; common onset is characterized by local infection, bleeding before phimosis, meatal stenosis that could cause urinary retention [8, 15].

Fig. 9.1
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Unretractable phimosis in catheterized patient

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9.2.3 Clinical Findings and Diagnosis

Generally, the unretractable foreskin shows inelastic scar tissue that prevent glans penis exposure; whitish color at the tip of the foreskin and edema are typical findings of BXO. In case of severe tightness of the foreskin, acute urinary retention is not a rare complication. Itchiness and redness of the glans penis in frequent when underlying balanitis is present. Diagnosis is related to history and physical findings. Histopathology of the foreskin removed is mandatory to confirm BXO as cause of phimosis.

9.2.4 Treatment

The treatment of choice to manage pathological phimosis is circumcision. In adults, circumcision is undertaken in operating room under local or general anesthesia. With the sleeve technique, a circumferential incision is made overlying the coronal impression of the glans through the skin. On the ventral surface, the skin incision should be in a V-shape opposite the frenulum. Once the foreskin is retracted, a second circumferential incision is made 0.5 cm below the coronal sulcus. On the dorsal surface, a plane superficial to Buck’s fascia between the two circumferential incisions is created through blunt dissection. The ring of the prepuce is incised along this plane and then removed circumferentially. The circumcision is completed reapproximating the skin and the dartos of the inner prepuce with absorbable sutures in separate layers. In those cases, when severe tightness of the foreskin make it impossible to retract it on in case of paraphimosis, a dorsal slit is performed from the tip of the prepuce extending from the circumferential outer skin incision to the inner prepuce below the coronal sulcus [16].

Other options to treat phimosis (not indicated in BXO) are designed to achieve a fully retractile foreskin and can be pharmacological and surgical. Topical steroids such as clobetasol propionate and hydrocortisone together with regular attempts of prepuce retraction can achieve high success rates in 4–8 weeks of therapy, thanks to the anti-inflammatory and immunodepressive action associated to foreskin thinning [17]. Between surgical option, preputioplasty is an attempt to achieve a loosening of the scar tissue through its longitudinal incision which is then sutured in a transverse way [18]. Several preputioplasty techniques have been described: Welsh reported a triple full thickness incision across the stenotic ring followed by transvers suturing. In Wåhlin preputioplasty, three rhomboid incisions along the scarring ring are performed and closed by oblique suturing while Hoffman reported the use of multiple V-Y plasty along the constricting ring [19, 20].

Disposable circumcision suture device has been recently introduced, and it has gained increasing popularity. Shorter operation time, standardization of the technique, better cosmetic appearance, and fewer complications have been reported compared to classic cirumcision [21, 22]. Different disposable devices in different sizes are available and generally consist of a bell-shaped glans pedestal, ring blade, handle, shell, and suture staple. During the procedure, the glans lies under the glans pedestal and the foreskin is wrapped around the rod of the circumcision device. Once the knob is triggered, the foreskin is cut by the ring-shaped blade and staples are placed [22].

9.3 Paraphimosis

9.3.1 Definition, Epidemiology, and Treatment

Paraphimosis is an urological/andrological emergency whose clinical manifestation is a foreskin left retracted due to entrapment of a tight of the tissue proximal to the corona, leading to venous and lymphatic congestion. Signs in a patient with paraphimosis are glans engorgement, edema, and erythema of the prepuce; if the condition persist for few hours, bluish discoloration, tears, and necrosis of the superficial tissue may happen. Firstly, a manual reduction should be attempted, pushing forcefully the glans and retracting the foreskin in the natural position; in case of severe edema, multiple punctures to the edematous tissue before manual reduction are recommended. If manual reduction is achieved, some authors advise circumcisions because of paraphimosis tendency to recur; whereas when manual resolution is not possible, a dorsal slit is mandatory [23, 24].

9.4 Short Frenulum

9.4.1 Definition, Epidemiology, and Treatment

Frenulum breve, or short frenulum, is a dysmorphism in which the frenulum of the penis, which is an elastic band of tissue under the glans penis that connects to the foreskin and helps contract it over the glans, is too short and thus hinders the movement of the foreskin, preventing full retraction of the foreskin.

The presence of a frenulum breve is a common cause for dyspareunia in males, often resulting in painful intercourse and trauma to the frenulum. Frenuloplasty is commonly performed under local anesthesia (either in day surgery or in an outpatient setting) as an alternative to circumcision for frenular pain and scarring, very effective procedure giving excellent functional results and patient satisfaction. Commonly, frenuloplasty is performed through a transverse incision of the frenulum which is then suture longitudinally with interrupted sutures. Careful hemostasis is mandatory due to the risk of severe bleeding from the frenula artery and its branches. Alternative techniques include the V-Y plasty and Z-plasty. The “pull and burn” technique described by Gyftopoulous is a sutureless approach involving the diathermy applied to the point of maximum tension of the frenulum followed by a controlled vertical tear [25, 26].

9.5 Micropenis

9.5.1 Definition and Epidemiology

Micropenis is a specific genitalia disorder whose incidence is about 1.5 per 10,000 newborns diagnosed through a thorough physical examination. The definition of micropenis is based on the stretched penile length (SPL; Fig. 9.2) measured from the pubis to the tip of the stretched penis (Table 9.1). 2.5 standard deviations less than the mean for the age without other pathological conditions of the penile shaft and distal urethra (i.e., hypospadias) [27, 28].

Fig. 9.2
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Stretched penile length measured from the pubis to the tip of the stretched penis. (Picture by Mr. David Ralph, St. Peters Andrology Centre, London, UK)

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Table 9.1 Normal SPL according to age and the corresponding 2.5 standard deviation defining micropenis [27, 28]
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9.5.2 Pathophysiology

Micropenis is a result of a hormonal abnormality occurring after 12 weeks of gestation. Sexual male differentiation is linked to the presence of SRY gene (sex-determining region Y) on the Y chromosome. The gonadal differentiation into testicular tissue mediated by SRY gene involves three hormones: AMH (anti-Mullerian hormone), testosterone, and DHT (dihydrotestosterone). AMH induces regression of the paramesonephric ducts; testosterone stimulates the development of the mesonephric ducts (Wolffian ducts) into seminal vesicle, vas deferens, and epididymis; dihydrotestosterone supplies growth to male sexual characteristics including scrotal sac maturation, penile, and testicular size [29]. At 8 weeks of gestation, gonadotropin from placenta stimulates the fetal Leydig cells to produce testosterone, thus inducing differentiation of genital tubercle, genital folds, and genital swelling into glans penis, shaft of the penis, and the scrotum, respectively. During the second and the third trimester, the growth of the penis occurs through fetal androgens, produced under stimulation by fetal pituitary gonadotropin. In the postnatal period, further growth takes place under the influence of the hypothalamic-pituitary axis leading to an high androgen levels between the first and the third month of life, then these levels reduce to the lowest until puberty [28].

Micropenis can be a result of a disturbance of the process started before, although true micropenis is considered to occur only from hormonals abnormality arising after 12 weeks of gestation (Table 9.2). The etiologies can be divide into five groups: deficient testosterone secretion (hypogonadotropic hypogonadism and hypergonadotropic hypogonadism), incomplete form of 5 alpha reductase deficiency or androgen receptor defects, idiopathic and associated with other congenital abnormalities [30]. In hypogonadotropic hypogonadism or secondary hypogonadism, the gonadal failure is due to abnormal pituitary gonadotropin levels related to absent or inadequate hypothalamic GnRH secretion or failure of pituitary gonadotropin secretion. Kallmann syndrome associated with anosmia or Prader-Willi syndrome associated with low height, hyperphagia and hypotonia can be diagnosed in patients with micropenis. In hypergonadotropic hypogonadism, the primary testicular defect is due to gonadal dysgenesis or associated with poly Y syndromes such as Klinefelter’s syndrome. Consanguinity or drugs used during pregnancy in particular anti-androgen medications (flutamide, testolactone, enzalutamide, and spironolactone) are possible cause of Idiopathic micropenis [28, 31].

Table 9.2 Common cause of micropenis
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9.5.3 Diagnosis

Physical examination is essential to produce an accurate diagnosis: in the first instance, the clinicians must have a clear definition of micropenis and how to measure the penis properly, hence to exclude confounding condition such as webbed penis and hidden penis.

Stretched penile length measurement is taken from the pubic bone, taking care to compress the suprapubic fat pad, to the distal tip of the penis which is put on maximal stretch with retracted foreskin. Assessment of the penile shaft circumference, volume of the testicles, and size of the scrotum are also recommended to rule out hypoplastic corpora cavernosa, cryptorchidism or small volume testicle and hypoplastic scrotum particularly in pediatric and adolescent population. Location of the urethral meatus and curvature of the penile shaft are other important characteristics to investigate. Endocrinological evaluation is recommended and a baseline measurement of gonadotropin releasing hormone (GnRH), luteinizing hormone (LH), and follicle stimulating hormone (FSH) are mandatory in case of clinical suspicion of hypogonadotropic hypogonadism which can be associated to adrenocorticotropic and growth hormone deficiency. Levels of prolactin help to understand the level of the defect in the hypothalamus-pituitary axis: high level is linked to hypothalamic defects whereas low level of prolactin is related to the pituitary glans [31]. Testicular function may also be assessed through serum testosterone levels and dihydrotestosterone. When abnormal laboratory findings are shown, ultrasound of the testis and brain MRI to evaluate the pituitary glands are indicated [32].

9.5.4 Treatment

Treatment can be divided in medical and surgical, and its aim is to achieve normal sexual and urinary function in the standing position. Regarding medical therapy, it is important to highlight that testosterone treatment of child on masculinization during puberty is still not fully clear and better long-term data are needed to fully understand the effects of treatment. Testosterone is available as intramuscular (IM) and topical: IM testosterone enanthate 25 mg is recommended every 3 weeks for 3 months, topical 5% testosterone cream in children and infants who are less than 8 years of age. Significant increase in penile length is reported but, if an unsatisfactory response is achieved after a short period of treatment, repeated administration for short periods may be performed. Dihydrotestosterone has been reported some efficacy especially in infants with 5 alpha reductase deficiency with an estimated 150% increase in penile length [33, 34]. Human recombinant FSH and LH treatment has been reported in children with micropenis in hypogonadotropic hypogonadism with a significant increase only in testicular volume and not satisfactory increase in penile size [35]. Surgical therapy is an alternative in the management of micropenis in those patients who proved unsatisfactory achievement with endocrinological therapy. Sex reassignment surgery in case of absence of testicular tissue was reported in the late 70th but more recently, this approach has been taken into consideration less frequently due to the psychological impact of gender reassignment [36, 37]. Taking into consideration the significant psychosexual problems in those adults who underwent sex reassignment surgery and the conflicting data regarding this kind of surgery, it should be undertaken with extreme caution in high volume centers [38, 39]. Reconstructive surgery is nowadays a challenging but valid option for the treatment of micropenis. The first series was reported in the early 1970s, and in the following decades, advances in penile reconstruction surgery have been described [40]. The harvesting of a fasciocutaneous neophallus on a free flap on the radial artery or anterolateral thigh flap (ALT) has been reported with satisfactory outcomes, and more recently, the osteocutaneous fibula flap, the free scapular flap, the suprapubic abdominal wall flap, and the vertical rectus abdominis flap have been proposed as surgical options for the treatment of micropenis [41, 42]. The radial forearm free flap is the gold standard site to penile reconstruction surgery, mostly applied in female to male transsexualism, which consists in a microsurgical dissection of a radial forearm flap, possibly the nondominant arm should be chosen for flap harvest, and construction of a tube-within-a-tube phallus while the flap is still pedicled to the forearm [41, 43, 44] (Fig. 9.3a, b). It is a versatile flap because it is possible also to transfer tactile sensation through incorporation of the medial or lateral antebrachial cutaneous nerve. A small skin flap and a full thickness skin graft is sutured proximally to the glans area to create the balanopreputialis sulcus. The receptor vessels are to the common femoral artery and the greater saphenous vein. The antebrachial cutaneous nerve is anastomosed to the ilio-inguinal nerve for protective sensation and the median nerve to one of the dorsal penile/clitoral nerves for erogenous sensation. Three months after surgery, the glans can be tattooed in order to create a more realistic glans appearance; the patient can undergo to implantation prosthesis surgery after a 12-month period when protective sensation has returned to the tip of the penis. The most common complications are related urinary fistulas, urethral strictures wound closure of the harvest site, flap anastomosis. Cosmetic and functional results are acceptable especially when a prosthesis is implanted but complications are frequent, and for this reason, a multidisciplinary team approach in high volume centers is recommended [41, 43, 44].

Fig. 9.3
figure 3

(a) Pre-operative appearance of micropenis; (b) post-operative results in patients with micropenis underwent to radial forearm flap; the native glans penis is preserved and left ventrally to keep erogenous sensation. (Picture by Mr. David Ralph, St. Peters Andrology Centre, London, UK)

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9.6 Buried Penis

9.6.1 Definition and Epidemiology

Buried penis is a penile abnormality in which the penis of normal corporal size and length barely protrudes from the body since it can be partially or completely hidden below the surface of the skin (Fig. 9.4). The penis can be located beneath the abdomen or the scrotum while in the most complex cases, it can lie beneath skin of the thigh. The differential diagnosis with micropenis lies in the normal size of the phallus which is affected by poor exposure [45]. Some authors use the term concealed penis as it allows a further sub-classification of the disease into trapped buried and complex penis. Buried penis was first classified by Crawford into partial and complete types in 1977: the partial type is characterized by the proximal half of the penile shaft buried in the subcutaneous tissue and gives rise to a “stumpy-looking” penis; whereas the complete type, the phallus is completely invisible and the glans is covered only by foreskin buried below the abdominal wall [46].

Fig. 9.4
figure 4

Buried penis in obese patient. (Picture by Mr. David Ralph, St. Peters Andrology Centre, London, UK)

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9.6.2 Pathophysiology

Buried penis can be caused by congenital or acquired conditions. Whereas acquired type of buried penis, in which the phallus is normal sized encompassed by skin, subcutaneous tissue and fat in the prepubic area, is often associated with other pathological conditions including obesity, balanitis xerotica obliterans (BXO), lymphedema, and complication of penile surgery. In case of obesity, the overexpression of the central abdominal and suprapubic fat pad can be responsible of buried penis; particularly, the fat in the suprapubic area can be difficult to loose and surgery represents the only option in these patients. This aspect is highlighted by the rate of patients surgically treated for buried penis who are obese in the 87% of the cases [47]. Balanitis xerotica obliterans (BXO) and recurrent infection in diabetic patients can cause sclerosis of the glans, urethra and foreskin can result in a scar of the skin of the penile shaft and prepuce with consequent entrapment of the penis below the suprapubic skin. Complications following circumcision could be responsible of buried penis in case of excessive foreskin removed or scarring of the suture line that can trap the penis and push it below the suprapubic area. A telescope mechanism of the penile shaft to the surrounding dartos and skin is at the base of the dysgenic dartos as cause of buried penis. In these patients, dartos fascia does not fix the penile skin to the deep fascia of the suspensory ligament and the consequent hypermobility of skin and fascia determines the retraction of the corpora and glans penis into the scrotum or below the pubis [47, 48].

9.6.3 Clinical Findings and Diagnosis

Physical examination is essential to establish the stretched penile length and exclude micropenis. The evidence of whitish phimotic skin and glans fusion are suggestive of BXO while abdominal and suprapubic examination often shows overhanging suprapubic fat. Commonly, patients complain of LUTS including straining to void and weak urine flow, post void dribbling and recurrent urinary tract infection. These symptoms are frequently related to coexisting meatal or urethral stricture. Inability to have sexual intercourse or painful erection are often reported by patients. During examination, the penis should be delivered in order to assess the glans, the urethral meatus, and the penile skin. In case of suspect of a urethral stricture, a urethrocystography or urethrocystoscopy is recommended [49, 50].

9.6.4 Treatment

The aim of the treatment of buried penis is to achieve voiding standing and restore sexual and cosmetic function. The authors report about the 87% improvements in voiding and up to the 94% in the sexual function [51]. In case of obesity, weight loss should be the first step with bariatric surgery for patients with a BMI >40 or over. In obese patients, surgical options include fat removal from the lower abdomen a suprapubic area. Panniculectomy, abdominoplasty, and suprapubic lipectomy are common surgical techniques used to reduce the amount of fat causing buried penis. During panniculectomy, which is indicated for the removal of subcutaneous fat and excessive skin following weight loss or bariatric surgery, a V-shaped incision is performed above the mons pubis from the skin level down to the rectus fascia. The suprapubic lipectomy includes the removal of the suprapubic fat through a W-shaped incision starting a couple of centimeters from the base of the penis. The amount of tissue removed can be linked to the intraoperative bleeding that can be significant in case of large panniculi. Abdominoplasty involves removal of the fat and skin in excess below the umbilicus and tightening (plication of the rectus abdominus) of the fascia of the abdominal wall with relocation of the umbilicus. Following fat removal, tacking suture from tunica albuginea to the ventral dartos is recommended in order to prevent retraction on the penile shaft [49, 50] and grafting of the penile shaft previously buried may be necessary (Fig. 9.5).

Fig. 9.5
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Post-operative appearence following suprapubic lipectomy and split thickness skin grafts to the penile shaft in obese patient. (Picture by Mr. David Ralph, St. Peters Andrology Centre, London, UK)

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In case of buried penis related to BXO, iatrogenic loss of penile skin or scarring and lymphedema, the approach is based on first instance on the removal of the skin affected by the disease and grafting in case of skin deficiency. If primary closure is not feasible, techniques used to correct the defects are flaps or autografting. When autografting, the surgeon has to deal with two choices: thickness of the skin graft and the harvest site suitable for the recipient site; commonly used harvest sites are the abdomen, lateral thigh, and in selected patients supraclavicular and postauricular skin; split thickness skin grafts (0.003 mm) are often used due to their good survival rated, the lack or hair follicle and good aesthetic match and no need for a local flap or subsequent grafting for the donor site, a compressive dressing is required; however, thick split graft tends to provide more mechanical resistance and less shrinkage rates at the cost of a major donor site care. In the first 24–48 h, the graft is without blood supply and appears white (nutrient and oxygen passively diffuse to the graft), then formation of vascular anastomose between the graft and the host begins producing capillary refill leading to a cyanotic appearance, finally the revascularization occurs. The graft over time may become hypopigmented or hyperpigmented. Following the harvest, the skin graft is placed on the recipient site, with quilting suture, or bolster and negative pressure wound dressing to prevent mobilization of the graft; in order to prevent hematomas and seromas, a graft’s healing disruptors, if using a not meshed skin graft, “pie crusting technique” is required, this technique entails creating perforation in the graft with blade [49, 52].