Inguinal Region

The inguinal canal runs obliquely between the external and internal inguinal rings. The anterior wall of the canal is formed by the external oblique aponeurosis; the posterior wall is formed by the inguinal ligament and conjoined tendon. The oblique direction of the inguinal canal allows for the posterior and anterior walls to coapt with increases in intraabdominal pressure.

Testis Descent

(See Nelson Textbook of Pediatrics, p. 2592.)

The testes develop in the lumbar region of the abdominal cavity between the peritoneum and the transversalis fascia at approximately 7 weeks of gestation. By the 8th week of gestation, the gubernaculum extends from the caudal end of the epididymis through the inguinal canal to insert on the internal wall of the scrotum. The processus vaginalis, a finger-like outpouching of the peritoneum, extends adjacent to the gubernaculum to form the inguinal canal. As the processus vaginalis descends into the scrotum, it carries extensions of the abdominal wall layers.

The testis normally descends through the inguinal canal into the scrotum before birth. As the testis and spermatic cord descend through the inguinal canal, they are covered by the three concentric layers of the anterior abdominal fascia ( Fig. 21.1 ). When the testis reaches the scrotum, the testis and surrounding layers of fascia and tunica vaginalis fuse to the dartos of the scrotum. The processus vaginalis is initially patent, leaving a connection between the scrotum and the peritoneal cavity. Normally, the processus vaginalis obliterates, leaving a residual tunica vaginalis surrounding the testis. Typically, the tunica vaginalis contains 1-2 mL of clear fluid.

Descent of the testis from week 7 (postfertilization) to birth. As the testis and spermatic cord descend through the inguinal canal, they are covered by the three concentric layers of the anterior abdominal fascia.

(From Drake RL, Vogl AW, Mitchell AWM, eds. Gray’s Anatomy for Students. 3rd ed. Philadelphia: Churchill Livingstone; 2015:253-420.)

Scrotum

The scrotum has 2 separate compartments, each containing a testis, epididymis, and distal spermatic cord. It comprises multiple layers that are continuous with the superficial layers of the anterior abdominal wall. The external location of the scrotum results in the temperature of the testes being 2-3°F below the core body temperature, which allows for normal spermatogenesis.

Testis

The testes are the male reproductive organs and are suspended in the tunica vaginalis of the scrotum by the spermatic cords. The epididymis, attached to the testis posteriorly, consists of the caput (upper pole), corpus (body), and cauda (tail) ( Fig. 21.2 ). The vas deferens can be palpated as a narrow, firm, tubular structure in the spermatic cord. The epididymis is responsible for sperm maturation and storage. Each testis relies on 3 arteries for its blood supply: the testicular artery, the cremasteric artery, and the deferential artery. Each enters the scrotum through the spermatic cord. The testicle receives both sympathetic and parasympathetic innervation. These autonomic nerves carry impulses that, with testicular stimulation, produce symptoms of deep visceral pain and nausea.

Lateral view of the testis showing the posterior location of epididymis and appendix testes. The appendix testis is present in almost all males, the appendix epididymis is present in approximately 50% of males, and the other appendages are rarely present.

(From Kelalis PP, King LR, Belman AB, eds. Clinical Pediatric Urology. 2nd ed. Philadelphia: WB Saunders; 1985.)

History

In evaluating acute or chronic scrotal swelling, the following historical elements should be established:

• 1.
  

  Onset of pain : Testicular torsion has a very sudden onset and can be precipitated by activity or can occur at rest or during sleep. Epididymitis or torsion of the appendix testis or other testicular appendage often has a more insidious onset over the course of days, with progressive pain and swelling.

  
  
• 2.
  

  Duration of pain : Episodic pain lasting seconds and abating is rarely pathologic, whereas severe pain, persistent pain, or episodes lasting more than 1 hour raise concern.

  
  
• 3.
  

  Associated/radiation of pain : If there is radiation of pain from the flank, then renal or ureteral pathologic processes, such as an obstructing ureteral calculus, should be considered. Inguinal discomfort may suggest hernia or other inguinal pathology.

Although sometimes nonspecific, associated manifestations are also important:

• 1.
  

  General systemic : Fever, chills, or rigors suggest an infectious cause.

  
  
• 2.
  

  Abdominal signs/symptoms : Nausea, vomiting, and abdominal or inguinal pain are common but nonspecific. They may indicate an intestinal process.

  
  
• 3.
  

  Urologic signs/symptoms : Dysuria, urinary frequency, hematuria, or penile discharge suggests an infectious process such as urinary tract infection, urethritis, or epididymitis.

  
  
• 4.
  

  Unusual rashes : Henoch-Schönlein purpura may result in vasculitis of the spermatic cord with associated scrotal pain and swelling.

In addition, a thorough medical history is imperative and should include the following:

• 1.
  

  History of urinary tract infections or renal calculi.

  
  
• 2.
  

  Prior sexual activity, which would raise the possibility of a sexually transmitted infection.

  
  
• 3.
  

  History of any surgical procedures on the groin, scrotum, or abdomen. Often an orchiopexy performed for an undescended testis places the testis in a dartos pouch, which would make testicular torsion unlikely in the future.

  
  
• 4.
  

  History of any previous episodes of testicular pain. Previous episodes of intermittent or severe pain in the same testis may be secondary to intermittent torsion of the testis.

  
  
• 5.
  

  Lower urinary tract pathologic processes, such as posterior urethral valves, neuropathic bladder, or urethral stricture (e.g., after trauma or hypospadias repair) may predispose to urinary tract infection, which could cause bacterial epididymitis.

Physical Examination

Examination of the scrotal contents should be performed in any male patient presenting with abdominal, inguinal, or scrotal pain. Essential components include inspection, palpation, and transillumination of any masses.

Laboratory Data

Basic laboratory evaluation of acute and chronic testicular swelling includes urinalysis, urine culture, and tests for Chlamydia and gonorrhea if the patient is sexually active (see Chapter 18 ).

Imaging Studies

Imaging studies are often helpful in determining the cause of acute and chronic testicular or scrotal swelling. They should not be substituted for a thorough history and careful physical examination performed by a surgical specialist. The conditions necessitating immediate surgical treatment include testicular torsion, incarcerated inguinal hernia, and testicular rupture secondary to trauma; testicular tumor mandates urgent surgical attention. If the history and physical examination strongly support the diagnosis of testicular torsion, then prompt surgical exploration is recommended, without confirmation by an imaging study. If the history or physical findings are equivocal for testicular torsion, or if an alternate diagnosis requires investigation, color Doppler ultrasonography should be obtained. Sonography provides a relatively accurate image of the testis and epididymis, and color Doppler imaging assesses blood flow. It is performed by examining the uninvolved testis first and adjusting the color flow settings to detect normal flow. The affected testis is then examined for decreased or absent flow in comparison with the normal testis. Color flow Doppler imaging distinguishes between the increased collateral blood flow within the scrotal skin and the decreased blood flow to the testis in patients with testicular torsion. The sensitivity of Doppler ultrasonography for detecting testicular torsion ranges from 69-100%, and specificity ranges from 77-100%. Sonography can also help determine if a scrotal hematoma represents a testicular rupture. Color flow Doppler imaging accurately demonstrates increased flow resulting from torsion of the appendix testis or epididymitis, but is usually unable to distinguish these 2 entities. It also cannot distinguish viral from bacterial epididymitis. If a tumor is present, sonography can demonstrate whether the mass arises from the testis or paratesticular structures. It can also distinguish the presence of hydrocele, cyst, tumor, or varicocele. The test is quick, easy to perform, and noninvasive. There are several important limitations of color Doppler imaging:

• 1.
  

  If the duration of torsion is brief and if the torsional rotation is incomplete, there may be venous congestion without impairment of arterial blood flow; color Doppler imaging may demonstrate normal or decreased blood flow.

  
  
• 2.
  

  In the prepubertal testis, blood flow may be difficult to demonstrate, even when the testes are normal, and absence of flow may be misinterpreted for testicular torsion.

  
  
• 3.
  

  The color Doppler aspect of the study is user dependent.