Scrotum Anatomy PPT Slides PDF

Chapter 23 SCROTUM Anatomy Sac at houses testicles of the Protection and temperature regulation Scrotum Two “halves” Separated by median raphe externally Separated by tunica dartos internally  TESTES Symmetric, oval-shaped g...

Chapter 23 SCROTUM Anatomy Sac at houses testicles of the Protection and temperature regulation Scrotum Two “halves” Separated by median raphe externally Separated by tunica dartos internally  TESTES Symmetric, oval-shaped glands Endocrine function: produce testosterone Exocrine function: produce sperm Anatomy (spermatogenesis) of the Testis measures 3-5 x 2-4 x 3 cm (adult) Scrotum Each testis divided into > 250 to 400 conical lobules containing the seminiferous tubules Tubules converge at apex of each lobule and anastomose to form rete testis in mediastinum Rete testis drains into head of epididymis through efferent ductules Testicular A&P Spermatogenesis Pathway of sperm: Seminiferous tubules Tubuli recti Rete testis Efferent ductules Ductus epididymis Vas deferens Anatomy of the Scrotum Testicles appear as smooth, medium gray structures with fine echo texture Anatomy of the Scrotum EPIDIDYMIS 6- to 7-cm tubular structure beginning superiorly and then coursing posterolaterally to testis Contains 10 to 15 efferent ductules from rete testis, which converge to form single duct in body and tail Divided into head, body, and tail Anatomy of the Scrotum EPIDIDYMIS Head: Largest part Superior to upper pole of testicle 10-12 mm in width Body: Smaller than head Follows posterolateral aspect of testis from upper to lower pole Tail : Slightly larger and positioned posterior to lower pole of testis EPIDIDYMIS Normal epididymis: Isoechoic or hypoechoic to testicle Echo texture coarser Anatomy of the Scrotum MEDIASTINUM Each testicle is covered by dense, fibrous tissue termed tunica albuginea Tunica albuginea extends posteriorly and enters the testicle to help form mediastinum testis Multiple septa are formed from tunica albuginea at mediastinum Course through testis and separate it into lobules Mediastinum supports vessels and ducts coursing within testis  Mediastinum Testis Mediastinum often seen on sonography as bright hyperechoic line coursing craniocaud within testis  Anatomy of the Scrotum Tunica vaginalis lines inner walls of scrotum, covering each testis and epididymis Consists of two layers Parietal and visceral: Parietal layer is inner lining of scrotal wall Visceral layer surrounds testis and epididymis Anatomy of the Scrotum Small bare area, which is posterior At this site, testicle is against scrotal wall, preventing torsion Blood vessels, lymphatics, nerves, spermatic ducts travel through area Hydroceles form in space between layers of tunica vaginalis The tunica vaginalis is well demonstrated because of the hydrocele.  Anatomy of the Scrotum Vas deferens Continuation of ductus epididymis Thicker and less convoluted Dilates at terminal portion near seminal vesicles Vas deferens joins duct of seminal vesicles to form ejaculatory duct, which empties into urethra.  Anatomy of the Scrotum Spermatic cord Suspends testis in scrotum Travels through inguinal canal Contains: Vas deferens Testicular arteries Venous pampiniform plexus Lymphatics Nerves Cremaster muscle Vascular Supply Aorta Common Testicular iliac artery Artery Internal External Capsular iliac artery iliac artery artery Inferior Centripetal Vesical epigastric artery artery artery Recurrent Deferential Cremasteri rami artery c artery (artery) Arterioles & capillaries Vascular Supply  Cremasteric and deferential arteries accompany testicular artery within spermatic cord to supply extratesticular structures Vascul Have anastomoses with testicular artery and may provide some flow to testis ar Cremaster Supply Branches from inferior epigastric ic artery artery (branch of external iliac artery) Provides flow to cremaster muscle and peritesticular tissue Deferentia Arise from vesicle artery (branch of l artery internal iliac artery) Supplies epididymis and vas deferens Vascular Supply Vascula r Supply Spectral Doppler showing the normal low resistance pattern of the intratesticular arteries. Vascular Anatomy Venous drainage of the scrotum occurs through veins of pampiniform plexus Exits from mediastinum testis and courses in spermatic cord Converges into three sets of anastomotic veins: Testicular Deferential Cremasteric Vascular Anatomy Right testicular vein drains into inferior vena cava Left testicular vein drains into left renal vein Deferential vein drains into pelvic veins Cremasteric vein drains into tributaries of epigastric and deep pudendal veins Sonography of the Scrotum Supine position Penis positioned on abdomen and covered with towel Patient asked to place legs close together to provide support for scrotum Rolled towel placed between thighs can support scrotum  Apply generous amount of warmed gel to scrotum High-frequency probes (10 to 14 MHz) Bilateral exam, with asymptomatic side used as comparison for symptomatic Sonograph side y of the Assess each testicle in sagittal and transverse Scrotum Size, echogenicity, and structure of each testis evaluated Testicular parenchyma should be uniform with an equal echogenicity between sides  Palpable mass, scrotal pain, swollen scrotum, or other reason? Patient Ask patient to describe symptoms, History including history, location, and duration of pain Question If mass is palpable, ask patient to s find lump. Place probe exactly over this location & scan Any injury or trauma? When did trauma occur? Surgical procedure? When?  Is the parenchyma homogeneous or heterogeneous? Clinical Is there a mass? If so, is it cystic or solid? Questions … Is the mass intratesticular or extratesticular? Is one testis much larger than other? Is one side swollen, or is one side shrunken? (Each testis should appear similar in size and shape) Is epididymis normal? Is skin thickened? Is there an absence of flow in testis or is it hyperemic? How does color Doppler compare between sides? Scanning Protocol SAGITTAL Long axis mid testis with long & AP measurements Long axis mid with Color and PW Doppler Must document arterial & venous flow Lateral to medial sweep Epididymal head with superior testis Scanning Protocol TRANSVERSE Mid testis with measurement Superior to inferior sweep Transverse view showing both testes Epididymal head Color Doppler of epididymal head  Explain procedure and preparation to patient; patient will get ready in private Image of right and left testicle Sonograph together for comparison in both gray scale and color Doppler. er Tips Perform Valsalva maneuver when varicocele suspected Sensitize color Doppler for slow flow when evaluating torsion  UNDESCENDED TESTICLE During embryonic growth, testes first appear in retroperitoneum near kidneys Testes should descend into scrotum from Cryptorchidi inguinal canal shortly before birth sm Testis usually found in inguinal canal; often palpable Cryptorchidism is bilateral in 10% to 25% of cases Associated with future infertility and malignancy  Cryptorchidis m Sonographic Findings: Undescended testicle is smaller and less echogenic than normal testis Usually oval with homogeneous texture Mediastinum rarely seen Undescended left testicle with normal right testicle. The undescended testis is smaller and hypoechoic compared with the normal right testis. Testicular Ectopia Very rare condition Ectopic testicle cannot be manipulated into correct path of descent Most common site for ectopic testicle to rest is superficial inguinal pouch Other sites include: Perineum Femoral canal Suprapubic area Penis Diaphragm Other scrotal compartment  Rare condition Anorchi Unilateral anorchia a (monorchidism) found in 4% of patients with nonpalpable testis More common on left side; definitive diagnosis depends on surgical diagnosis Causes: Intrauterine testicular torsion or other forms of decreased vascular supply to testicle in utero Polyorchidis m (Testicular Duplication) Very rare disorder; more common on left side (75%) Bilateral in 5% of cases Associated with: Malignancy Cryptorchidism Inguinal hernia Torsion Supernumerary testicle is usually small  Torsion Appendages Fluid Collections Trauma Scrotal Varicocele Inflammation Pathology Epididymitis Orchitis Epididymo-orchitis Microlithiasis Masses  Arterial blood supply to testicle is interrupted Torsion secondary to twisting of spermatic cord Commonly due to Bell clapper deformity Tunica vaginalis completely surrounds testis, epididymis, distal spermatic cord, allowing them to move and rotate freely within scrotum. Bilateral More common in adolescence (12-18 years)  Torsion Compromises blood flow to testis, epididymis, and intrascrotal portion of spermatic cord Venous flow affected first with occluded veins, causing swelling of scrotal structures on affected side If torsion continues, arterial flow obstructed and testicular ischemia follows 360-degree torsion affects all vessels  Torsion is a surgical emergency! Surgery within 6 hours of onset of pain, 80% to 100% of testes can be saved Between 6-12 hours salvage rate is 70% After 12 hours only 20% will be saved After 24 hours, typically not salvageable Torsion Clinical S&S: Acute onset pain (often during sleep) Possible lower abdomen or inguinal pain Swollen testis/scrotum Nausea & vomiting Malposition of testicle Torsion Sonographic Appearance: Enlargement of spermatic cord, epididymis and testicle Absent or diminished intratesticular flow Heterogenous, hypoechoic testicle Hydrocele Thick scrotal wall  Normal finding, may not be seen in absence of fluid Embryologic remnants Small pieces of tissue originating from: Testicle – between head of epi and superior pole of testicle Appendag Epididymis – at head of epi Appendages can become torsed es Most common cause of acute scrotal pain in prepubertal boys “Blue-dot sign” After torsion, appendix becomes mobile and calcified – scrotal pearl Appendices  Potential space exists between visceral and Fluid parietal layers of tunica Collection vaginalis This space is where a s hydrocele, pyocele, or hematocele may develop.  Hydrocele Collection of serous fluid Most common cause of painless scrotal swelling. May be idiopathic, but commonly associated with epididymo-orchitis and torsion  Pyocele Collection of pus. Occur with untreated infection or when an abscess ruptures into space between layers of tunica vaginalis Hematocele Collection of blood Secondary to trauma Sonographic appearance: Varies with age of injury Acute hematocele - Echogenic with numerous, highly visible echoes that can be seen to float or move in real time Over time, hematoceles show low-level echoes and develop fluid-fluid levels or septations