The incidence of cryptorchidism is higher in the neonatal period, but with the growth of the child, the incidence of the disease decreases, but the incidence of cryptorchid still remains 1% at approximately 1 years old[1, 13]. Cryptorchidism can affect reproductive function, cause a decrease of fertility or even infertility, and increase the probability of testicular tumours. Cryptorchidism is also one of the predisposing factors for testicular torsion. Therefore, early active treatment is needed[14–15]. The testes of children with cryptorchidism may continue to descend after birth, but the chance of self-descent after 6 months is obviously reduced. Therefore, children require evaluation for the possibility of a medical intervention after 6 months[16–19].
The treatment of cryptorchidism includes endocrine therapy and surgical treatment, but the effect of endocrine therapy is not accurate. There are some side effects with endocrine therapy, so surgery is still the preferred treatment for cryptorchidism. At present, the main surgical methods for the treatment of cryptorchidism are laparoscopic surgery, inguinal incision surgery and scrotal incision surgery. The choice of surgical technique is made according to the location of the testis, a physical examination and whether the testicle can be explored by ultrasound. Laparoscopic exploration and simultaneous treatment of celiac cryptorchidism is a consensus[6–8].Lower scrotum high position cryptorchidism and sliding testis are basically operated on through a scrotal incision[9–10]; however, there is no consensus on the most appropriate surgical method for inguinal cryptorchidism.
For inguinal cryptorchidism, the traditional operation adopts the transinguinal approach and makes an oblique incision, transverse incision, or scrotal double incision to find the testis; frees the spermatic cord; transverse or ligated sheath process; fully releases the spermatic cord and vas deferens; and fixes the testis in the middle or lower part of scrotum without tension. This surgical procedure is clearly exposed, technically mature and effective. However, this operation must incise the aponeurosis of the external oblique abdominal muscle and destroys the normal anatomical structure and nerve of the inguinal canal, causing great trauma and leaving obvious scars in the inguinal area after the operation that will affect the aesthetic appearance. With the increasing demands of children and their families regarding the aesthetics after surgery, paediatric surgeons need to consider not only achieving the effect of surgery but also achieving an aesthetically pleasing and scarless result.
Because of the short distance between the outer ring orifice and the upper scrotum, the skin is loose and the length of the sheath process in most children with cryptorchidism is shorter than that in normal children. The length of the inguinal canal increases most between the ages of 1 and 3. The length of the inguinal canal in a 1-year-old child is 1.4 cm, is 1.9 cm at the age of 2 and is 2.7 cm at the age of 3. Therefore, an operation through scrotal incision can expose the external ring of inguinal canal, reach high transection or ligation of the sheath process, and completely transect the extraspermatic fascia and intraspermatic fascia to ensure sufficient release of the spermatic cord. Then, the testis can be placed in the scrotum without tension. The operation only needs a single scrotal incision, which does not need to destroy the inguinal structure like the traditional operation. The operation leads to less trauma, less postoperative pain, is simple, and the incision is located in the scrotal fold. There is basically no scar after the operation, and the cosmetic effect is good. In this study, the operation time and incision length of this method were significantly shorter than those of inguinal incision (P < 0.05). However, it took a long time and required traction. The incidence of scrotal swelling after the scrotal incision operation was higher than that after the inguinal incision operation and laparoscopic operation (P < 0.05). Therefore, the operation should be gentle and pay attention to haemostasis, and the scrotum should be slightly compressed after the operation. The scrotal incision has a low location, small incision and relatively small field of vision. The difficulty of the operation lies in fully releasing the spermatic cord vessels and the high ligation or transection of the sheath process. For cases with a high testicular position or older age, the operation is more difficult. In such cases, we can cut the outer ring mouth at 0.5-1.0 cm, which meet the needs of loosening the spermatic cord and ligating the sheath process. In this group, 5 sides of the outer ring mouth were cut, and good results were achieved. However, due to the differences in surgical experience, if it is difficult to release the spermatic cord vessels during the operation (sometimes even if the outer ring mouth is cut 0.5-1.0 cm), a tension-free testicular descent will not be guaranteed. Laparoscopy can be used to further free the spermatic cord or inguinal incision to free the spermatic cord. Therefore, although testicular descent fixation through scrotal incision has the advantages of a short operation time, less trauma and good cosmetic effect, its indications should be understood grasped before the operation.
Laparoscopic testicular descent fixation also has no inguinal incision, no inguinal canal incision, less trauma, less pain, and a good cosmetic effect; additionally, the scope of laparoscopic exploration is large and clear, which can determine whether there is a testis and its location (especially high cryptorchidism) and can fully free the spermatic vessels to the inferior pole of the kidney. It can be carried out under direct vision, thus reducing the damage to the testicular blood supply and ensuring tension-free testicular descent into the scrotum. Although laparoscopic surgery has complications, such as intestinal injury, bladder injury and subcutaneous emphysema caused by CO2 pneumoperitoneum, their incidence is low and can be avoided as long as care is taken during the operation[23–24].
The incidence and severity of postoperative complications are important indicators for judging the safety of surgical procedures. There were no complications, such as testicular atrophy, testicular retraction, inguinal hernia or hydrocele, in the three groups during the perioperative period and at the 1 year follow-up after the operation, and the size of the affected testis was improved to varying degrees. There was no significant difference between the three groups, indicating that scrotal incision, inguinal incision and laparoscopic testicular descent fixation have a good early curative effect for inguinal cryptorchidism and that their curative effect is similar. However, this study is a single-centre retrospective study with a small sample size and short follow-up time. Multi-centre, large sample, medium- and long-term follow-up studies need to be completed to determine the clinical outcomes of these procedures more objectively.