In Greek, 'cryptos' means hidden and 'orchis' means testicle. Although cryptorchidism was recognised since antiquity, the first studies were by John Hunter. His impression was that the gubernacuium caused the descent of the testes was accepted for years. Cryptorchidism is the most common genitourinary disorder in childhood. Even though the incidence may have slightly changed, there has always been great interest in the management of undescended testes. The role of laparoscopy in diagnosis and management, the timing of surgery, the risk of infertility and cancer and role of hormone therapy are some areas which fascinated both the paediatricians, surgeons and urologists.
Incidence
Cryptorchidism is frequent in premature infants, but spontaneous descent often occurs during the first 3 months of life. The incidence of cryptorchidism tends to follow gestational age rather than weight in the premature child. Overall, there is a 21 percent incidence of cryptorchidism in premature boys. For those infants weighing less than 1500 gm, the incidence is 60-70 percent. In full term male infants, weighing over 2500 gm, the incidence of cryptorchidism at birth is 2.7 to 3.2 percent. By the time child is 6 weeks of age, two thirds of the undescended testes in full - term infants will descend spontaneously. At age 1 year, the incidence of cryptorchidism is 0.8 percent. In adult men who are being examined for military service during World War II, cryptorchidism was reported in 0.4 percent. Spontaneous descent, therefore, does occur in the first 3 month of life, especially in prematures. There is no further descent even in premature boys and the incidence does not change after 1 year of life. In school going children, the incidence is slightly higher because of retractile testis as cremasteric muscle activity is more in this age group. Of boys having cryptorchidism, the condition is bilateral in 10 to 25 percent, with right sided involvement being slightly more common. About 14 percent of patients with undescended testes will have a family history of cryptorchidism.
Classification
Undescended testes can best be classified as palpable or nonpalpable. In non palpable testes, there can be testicular atrophy or agenesis, however the most likely situation is that of intraabdominal undescended testes. The nonpalpable testes may be Transient in an abdominal position but capable of assuming an intracanalicular position. In case of agenesis or atrophy, there is a striking preponderance on the left side.
Palpable testes may be retractile, ectopic or arrested in the normal pathway of descent. The most common is the superficial inquinal testis, which has traversed the inquinal canal but resides superior to the external oblique. Retractile testis may be due to an overactive cremasteric reflux or inadequate scrotal attachment. They are most commonly seen in the preschool age group, although they may be seen until puberty. Usually retractile testes are bilateral, but unilateral cases are not uncommon. Rarely, a short series of human chorionic gonadotropin (hCG) injection e needed for diagnostic assistance.
Ectopic testes are usually perineal and sometimes an abnormal gubernaculum like attachment is demonstrable. They may also located in the opposite scrotal sac, at the base of the penis, or in the thigh. Though it is always assumed that a descended testis remained descended for life, there are now many instances recorded where previously fully descended were found subsequently to "ascend" spontaneously thereafter and to occupy a permanent extrascrotal position. These testes also are subject to the same degenerative process that primary cryptorchid testes will undergo. It is therefore important for the pediatrician to examine the testes and record their position in the scrotum at each annual examination.
The "gliding testes" is a form of cryptorchidism in which the undescended testis can be manipulated in to the upper scrotum but retract immediately when tension on it is released. The two anatomic characteristics of the "gliding testis" are that it has no gubernaculum attachment, which may make it more prone to torsion, and that there is a wide process vaginalis present which make the testis more mobile.Testes may become dislocated secondarily as well, that is, after herniorrhaphy, and may adhere internally to the inquinal scar. In these instances, secondary orchidopexy may be necessary to prevent testicular atrophy, which may subsequently over a period of time, even though the testis was initially normal and fully descended.
Embryology and Natural history of Testicular and etiology of cryptorchidism
At 6 weeks gestation, primordial germ cells from the yolk sac migrate to the genital ridge. At 7 weeks, under the influence of testis-determining genes, these and adjacent cells develop in to a testicle. The testis becomes hormonically active at 8 weeks of gestation and consists mainly of large sertoli cells that line the primitive seminiferous tubules and small Leydig cells. The fetal Sertoli cells, stimulated by follicuiar stimulating hormone(FSH) from the pituitary, secrete Mullerian inhibiting factor(MIF), which causes involution of the ipsiiateral Mullerian ducts. MIF also increases the number of androgen receptors on the Leydig cells, stimulated by placental chorionic gonadotropin and pituitary luteinizing hormone(LH), secrete testosterone, which is essential for Wolffian duct differentiation in to epididymis, vas deference and seminal vesicles.
External genital development is complete by 10 to 15 weeks gestation and is dependent on the conversion of testosterone into dihydrotestosterone (DHT) by the enzyme 5-alpha reductase, which is present in the tissues of the developing external genitalia.DHT binds with the androgen receptors of the external to transform an indeterminate - appearing embryo in to a male fetus.
Normally descended and cryptorchid testes usually have identical histology until age 1 year. Soon thereafter, the cryptorchid testis begins to undergo progressive deterioration, that is, a diminishing number of germ cells, abnormal leydig cells, and peritubular fibrosis. The contralaterai descended testis also sometimes show germ cell loss, though to a lesser extent.
Cryptorchidism can occur as an isolated anomaly or may be an associated feature of other congenital, endocrine, chromosomal, or intersex disorder. Although the exact mechanisms involved with testicular descent remain unidentified, it is generally agreed that endocrine , mechanical, and neural factors all potentially play significant roles. Several salient features lead to testicular descent: formation of the process vaginalis and the attachment of the gubernaculum to the lower end of the epididymis between 5 and 8 weeks of gestation; also, differential body growth of the embryo, causing transabdominal descent of the testis to the level of the internal inquinal ring, which is completed by 12 weeks gestation. The testis lies dormant at this level until 26 to 28 weeks gestation. In addition, transinguinal testicular descent occurs during the last trimester of pregnancy. During this time, the gubernaculum swells to form the inquinai canal, and the testis follows in to the scrotum. The genitofemoral nerve innervates the gubernacuium and produce neurotransmitter, resulting in rhythmic gubernacular contractions that guide testis through the inquinai canal in to the scrotum. Mechanical components of testicular descent, including traction on the epididymis by the gubernaculum and cremasteric muscle and elevated abdominal pressure, also may play a role.
Pathophysiology
Fertility : Fertility is the most important consideration in the case of the undescended testicle. The bilateral cryptorchid male who goes untreated will be sterile with a very rare exception. Of those successfully treated, the fertility rate may be only 40 percent. The fertility rate in unilateral cryptorchidism after surgery varies from 40 to 80 percent, with a mean of 60 percent. Part of the reason for infertility is the frequency of congenital abnormalities of the ductal system which occur in one third of the cases. The higher the testes, the more likely the spermatic duct is to be abnormal.
Germinal epithelium degenerative changes are heat- mediated, as the scrotum is 1.5 to 2.5 degrees Celsius cooler than the abdomen. In unilateral cryptorchid mate, low fertility rate is due to degenerative changes in the scrotal testes, as a result of autoantibodies. It is postulated that weakness of the Sertoli cell junction may be present or that a heat mediated insult may produce antigens to spermatids, which may escape into the somatic environment to be exposed to the host immune system. Antitestis antibodies may cause the deposition of immune complexes in the seminiferous tube wall. The result is decreased permeability of the basement membrane of both the cryptorchid and the descended testes to substances required for spermatogenesis. Bilateral testicular dysfunction occurs. The possibility of avoiding this pathophysiologic development by early orchidopexy is enticing.
Endocrine function
Endocrine disorders : These do not result from cryptorchidism. There is no effect on basal testosterone produqtion. The values for serum LH and follicle-stimulating hormone (FSH) are increased in bilateral anorchidic individuals. Elevated levels of FSH correlate with compromised testicular function, while increased LH indicates lack of gonadal tissue. If LH levels are increased in presence of no palpable testicular tissue, there is no need for retroperitoneal exploration. There is no effect of the undescended testicle on libido, development of secondary sex characteristics, male attitude, growth, development and closure of epiphyseal growth centers.
Malignancy., Malignancy occurs with greater frequency in the patient with cryptorchidism than in patients whose testes have descended normally and bilaterally. Even the scrotal testicle in the unilaterally cryptorchid patient is associated with a significantly greater incidence of malignancy. The cryptorchid patient has a 42 fold greater chance of developing a malignancy. A compilation of several series found the incidence of cryptorchid patients having cancer to be 11.6 percent. At AlI India Institute Rotary Cancer Hospital, in a series of 164 patients of testicular cancer, 24 (14%) were found to have cryptorchidism. It has been suggested that if surgery is accomplished early enough, there is a diminished chance of a malignancy developing. It is felt that there is something inherent in the testicle that predisposes to malignant degeneration., Although the temperature in the abdominal and inquinal area is same, abdominal testicles are associated with an incidence of malignancy that is 6 times higher. Cryptorchidism and testicular cancer may be related to a common risk factor- excess free estrogens in the first trimester of pregnancy.
Orchidopexy may produce positive and negative effects should malignancy subsequently develop. The tumours develop in the treated patients who are slightly older, i.e., 40 years versus 32 years. in older patients, the percentage of seminoma increases and prognosis is better for these tumours. Orchidopexy alter lymphatic drainage, making inquinal and abdominal lymph node dissection advisable. In cryptorchid male, risk of malignancy in the testicle is rare after the age of 32 years, therefore no treatment is advised for cryptorchidism in adults who present after the age of 32 years.
Testicular torsion : Torsion of an undescended testicle can occur anytime during intrauterine development or later. It probably accounts for many cases of unilateral anorchia discovered at inquinal exploration for an empty scrotum. Postnatal torsion of the undescended testis is uncommon.
Associated lesions : Hernias are commonly associated with cryptorchidism in about 60 percent of cases. If hernia is troublesome, it should be corrected regardless of age and the testicle should be placed in the scrotum during the same procedure.
Spermatic duct abnormalities may be associated in about 11 percent of cases of cryptorchidism. Sometimes there is a history cystic fibrosis or congenital rubella, but often there is no history of these associated conditions.
Urinary tract abnormalities in patients with cryptorchidism and the congenital rubella syndrome may reach 18 percent, but in general the incidence is so low as to not justify routine excretory urography. With bilateral undescended testes, the incidence may be higher. The surgeon should look for these abnormalities, and if present, family should be informed of its presence and significance.
Diagnosis
Many patients with cryptorchidism can be diagnosed by visual inspection. Retractile testes can frequently be seen residing in the scrotum prior to palpation of the scrotum. It is important to have a calm patient for examination and few moments devoted to this end are worthwhile. The examiner should run some warm water over his or her hand. Usually the inquinal or upper scrotal testicle can be felt and some impression of the cord length can be obtained. With experience, atrophic gonadal tissue, cord structures, or even a hernia sac extending beyond the nonpalpable testicle may be felt. When no testicle is found in the usual area, ectopic sites, including the perineum and opposite side of the scrotum must be examined.
When no testicle is palpable, there are three possibilities- agenesis, atrophy, or an intra- abdominal testicle. In these situations, agenesis is unusual but the other two possibilities are common. Atrophy is suspected by palpation of cord like structures with no testicle.
When no testes are palpable on either side, the presence or absence of testicular tissue can be determined by hCG stimulation of serum testosterone levels. Failure of testosterone levels to rise several fold in response to hCG stimulation indicates absence of testicular tissue.
Investigations
A variety of investigations are employed in clinical practice to search for the impalpable testes. These include herniography, ultrasonography, computed tomography(CT) scanning, magnetic resonance imaging (MRI), testicular arteriography and or venography, and pediatric laparoscopy. Herniography is the oldest but least commonly practiced test because of unacceptable high incidence of false-positive and false-negative results. Ultrasound scanning has been helpful in locating the testis only if it is located underneath the aponeurosis of the external oblique muscle or is intraabdominal. Ultrasound is not very reliable.
CT scanning may be useful in bilateral impalpable testis to document their location but the test is expansive, emit radiation and sometimes is difficult to perform in young child. MIRI is more helpful than CT scan but like CT scanning may be difficuft in young child. It is however least invasive of all investigations.
Angiography of the testicular vessels is technically difficult and its complications (e.g. femoral thrombosis) may have disastrous consequences. Testicular venography has less morbidity than arteriography but is still an invasive procedure. Venography relies on the fact that when the pampiniform plexus of veins is visualised, the testis presumably is always present. However if the plexus is not visualized or if the testicular vein is blind ending, one can not equivocally state that the testis is absent on that side.
Pediatric laparosoopy has evolved as an important toot in the search of the impalpable testis and is replacing all other investigations. Diagnostic laparoscopy can be combined with the treatment of undescended testis under the same anaesthesia. If the testicular vessels are seen ending blindly, it signifies that the testis is absent on that side and that no surgical exploration is necessary. If the vessels are seen entering the inquinal ring, an inquinal exploration is all that is required. When the testis is seen in the abdomen, a decision is to be made for laparoscopic orchidopexy in one or two stages or laparoscopic orchidectomy.
Surgical therapy
Age at treatment : Historically the age at operation has progressively moved toward the date of birth. It is recommended that the surgery should be performed in the first year of life or at least at the beginning of the second year.
Indicatons : The indications of treatment of cryptorchidism is to enhance fertility, to prevent malignancy and to avoid psychological impact on the child.
Contraindicatlons : There are circumstances in which patients will not benefit from orchidopexy, with no likelihood of increased fertility, with no decreased chance of malignancy, or with no improvement in body self image. These states include deficient testes, testes associated with severe endocrine or enzyme defects, mental incapacity, and ejaculatory disorders.
Surgical techniques
Orchidopexy
Inquinal approach is the most commonly approach for orchidopexy. Bevan in 1899 emphasized the principles of orchidopexy. They are - mobilization of the spermatic cord, repair of associated hernia and adequate scrotal fixation without tension. These principles should be followed. The dartos pouch technique is usually preferred. If the testis won't go in to the scrotum without undue tension, the surgeon has four options:
Orchiectomy
Staged orchidopexy
Vessel transaction as described by Fowler Stephens
Autotransplantation.
Orchidectonry: If the testis is small atrophic or dysgenic, and if a normal contralateral testis is present, orchidectomy is a reasonable option. A prosthesis may be placed in the scrotum at this time if the option has been discussed with the family otherwise at a later date.
Staged orchidopexy : This has been recommended by Persky and Albert in which the testis is sutured to the external inquinal ring or the pubis and second stage repair is done 8-10 months later. The procedure results loss of testis in one third of the boys.
Orchidopexy using Fowler Stephens principle : Fowler and Stephens and many others have demonstrated many proximal anastomoses among the three major arterial supplies to the testis and epididymis- the cremasteric vessels, the artery of vas deference, and the testicular or internal spermatic artery. Thus the basic principle of the Fowler and Stephens orchidopexy is that, these anastigmatic connections are maintained, the testis will remain viable.