Hydrocele and Spermatocele

Hydrocele and Spermatocele




Hydroceles were described as early as the 16th century by the French surgeon Ambroise Paré and refer to an abnormal collection of serous fluid between the parietal and visceral layers of the tunica vaginalis. They are the most common cause of painless, nonacute scrotal swelling, with an estimated incidence of 1% in the adult population (1) and are more commonly seen after the age of 40 years.

Embryology and Etiology

In order to understand how hydroceles form, one must understand the embryologic origin of the inguinal canal and the process of testicular descent. As the testis develops, it is anchored by two ligaments, the cranial and the caudal suspensory ligaments. The caudal suspensory ligament, also known as the gubernaculum, fixes the testis within the scrotum and directs its course during descent. At approximately the seventh week of development, shortening of the gubernaculum pulls the testis from the level of the 10th thoracic vertebra through the inguinal canal and toward the scrotum. As the gubernaculum shortens, its most ventral peritoneal cover invaginates to develop a semicircular blind-ending cavity, known as the processus vaginalis. The growth of the processus vaginalis is directed inferiorly and drags the various layers of the abdominal wall with it, leading to the formation of the inguinal canal (2).

Testicular descent is divided into two phases: the intraabdominal phase and the inguinal-scrotal phase. During the intra-abdominal phase between the 7th and 12th weeks of gestation, the gubernaculum shortens and pulls the testis down to the level of the deep inguinal ring. The testis remains in the vicinity of the deep ring until the seventh month of gestation then, in response to multiple factors including hormonal changes, the inguinal-scrotal phase begins and the testis descends through the inguinal canal and into the scrotum by the ninth month of gestation. Just before term delivery, the testis has completely entered the scrotum, and the gubernaculum has atrophied to a ligament that attaches the lower pole of the testis to the scrotum.

As the testis descends and the processus vaginalis develops, each layer of the abdominal wall contributes to the spermatic cord. The first layer encountered by the processus vaginalis is the transversalis fascia—this layer will become the internal spermatic fascia of the spermatic cord. Because the transversus abdominis muscle is not completely developed near the inguinal canal, this layer does not contribute to any of the layers. Next, the processus vaginalis pulls the fascia of the internal oblique muscle with it, which becomes the cremasteric fascia of the spermatic cord. Finally, the processus vaginalis evaginates into a thin layer of external oblique muscle, which becomes the external spermatic fascia (3) (Fig. 73.1).

The processus vaginalis surrounds the testis to form the visceral and parietal layers. After testicular descent, the proximal end of the processus vaginalis located within the inguinal canal normally seals, leaving a small patent remnant surrounding the testis called the tunica vaginalis. If the proximal aspect fails to seal (patent processus vaginalis), communication between the tunica vaginalis and the abdominal cavity remains, and the tunica vaginalis will fill with serous fluid leading to formation of a communicating hydrocele. In some instances, the communication may be large enough to allow development of an indirect hernia (Fig. 73.2). A patent processus vaginalis is the most common cause of hydrocele in the pediatric population and usually resolves spontaneously by 18 to 24 months of age (4).

Hydroceles in the adult population are generally acquired, noncommunicating hydroceles in which serous fluid accumulates within the tunica vaginalis. In the majority of cases, they are idiopathic (1), caused by either excess fluid production or inadequate drainage of fluid. Oversecretion of fluid may occur in response to infection or inflammation (e.g., orchitis), tumor (e.g., testicular cancer), obstructing testicular lymphatics, or trauma to the scrotum or inguinal canal. Inadequate drainage may develop as a result of prior inguinal or pelvic surgery. For example, one common cause of acquired hydrocele is nonmicrosurgical varicocelectomy (5) in which cord lymphatics, present in abundance within the sheath of the internal spermatic veins, are ligated along with the veins. Other surgical procedures such as inguinal hernia repair and renal transplant have been associated with hydrocele development. In addition, infection may cause lymphatic obstruction, such as in patients with the nematode parasitic infection Wuchereria bancrofti and, more commonly, severe or recurrent epididymitis or orchitis.

Diagnosis and Preoperative Patient Preparation

The normal scrotum contains 2 to 3 mL of fluid between the tunical layers with continuous production and drainage maintaining this volume at equilibrium. Sonographically detected hydroceles have been reported in as many as 65% of healthy men (6). The volume at which tunica vaginalis fluid becomes a hydrocele is not clearly defined. Even in cases of an obvious hydrocele on physical examination, the amount of fluid can be extremely variable among patients and may range from small and soft to large and tense.

Most commonly, patients present with complaints of painless swelling in one or both sides of the scrotum, occasionally reporting a vague scrotal pain or sensation of heaviness.
Men may seek evaluation due to scrotal discomfort during intercourse or physical activity, anxiety in regard to the cosmetic appearance of the scrotum, concerns about damage to the reproductive organs, or fear of malignancy. Cases of painful and acute-onset hydrocele are usually secondary to trauma, infection, or testicular torsion and should be investigated promptly.

FIGURE 73.1 Anterior view of testis detailing the layers of the scrotum and their embryologic origins: (A) visceral tunica vaginalis, (B) parietal tunica vaginalis, (C) internal spermatic fascia, (D) cremaster muscle, (E) external spermatic fascia, (F) dartos layer, and (G) skin.

FIGURE 73.2 Types of hydrocele: (A) noncommunicating hydrocele, (B) hydrocele of the cord, and (C) communicating hydrocele.

In the pediatric population, the parent may report that the degree of scrotal swelling fluctuates in size, often noting enlargement of scrotal swelling with increased abdominal pressures, such as during crying episodes. This finding usually suggests a patent processus vaginalis.

The diagnosis of hydrocele is made clinically by appreciating fluid around the testis, and one can usually transilluminate the scrotum. In patients with long-standing hydroceles in which the tunica vaginalis is thick, highly inflamed, and fibrotic, the fluid collection may fail to transilluminate. In all cases of suspected hydrocele, especially when the testis cannot be palpated due to the size of the hydrocele, an ultrasound is warranted to confirm the diagnosis and to rule out testicular lesions suspicious for malignancy (7). Additional investigations, such as complex imaging, are generally not required. It is important to assess for presence of a patent processus
vaginalis or a concomitant inguinal hernia, as an inguinal approach would be appropriate for hydrocele repair in such circumstances. An inguinal approach is also necessary when neoplasm is suspected on scrotal ultrasound but not definitively diagnosed preoperatively.

Indications for Treatment

Hydroceles can cause discomfort and embarrassment due to size and may have a negative impact on work performance, sexual function, and daily activity, particularly in patients with advanced lymphedema and large hydrocele caused by lymphatic filariasis (8). Treatment is indicated when the patient complains of discomfort or disability due to size of the hydrocele. Data are scarce related to the possible effect of hydrocele on testicular function. It has been postulated that hydrocele may act as an insulator, leading to an increase in scrotal temperature with a possible subsequent negative impact on spermatogenesis (9). Tense hydroceles may cause pressure atrophy of the testis and increase the resistive index of the subcapsular artery (10).

Apr 24, 2020 | Posted by in UROLOGY | Comments Off on Hydrocele and Spermatocele

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