The incidence of cryptorchidism is higher in the neonatal period than in later stages of development, but the incidence of cryptorchid remains 1% at approximately 1 years of age[1,15]. Cryptorchidism can affect reproductive function, cause decreased fertility or even infertility, and increase the probability of testicular tumours. Cryptorchidism is also a predisposing factor for testicular torsion. Therefore, early active treatment is needed[16-17]. 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 medical intervention after 6 months[18-20].
For inguinal cryptorchidism, the current surgical methods are mainly laparoscopic surgery, transinguinal incision surgery and transscrotal incision surgery. The traditional operation adopts the transinguinal approach and involves an oblique incision, transverse incision, or double scrotal incision to find the testis; then, the spermatic cord is freed, the sheath process is transected or ligated, the spermatic cord and vas deferens are fully released, and the testis is fixed in the middle or lower part of the scrotum without tension. This surgical procedure provides clear exposure and is technically mature and effective; however, this surgery leaves 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 achieving not only an effective surgery but also an aesthetically pleasing and scarless result.
The length of the inguinal canal increases most between the ages of 1 and 3. The length of the inguinal canal in a 1-, 2- and 3-year-old child is 1.4 cm, 1.9 cm, and 2.7 cm, respectively, and most children with cryptorchidism have a shorter inguinal canal than other children[21]. Therefore, performing surgery through a scrotal incision can expose the external ring of the inguinal canal and allow high transection or ligation of the sheath process and complete transection of 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 requires only a single scrotal incision that does not destroy the inguinal structure as in the traditional operation. The operation is simple and leads to less trauma and postoperative pain, and the incision is located in the scrotal fold. Essentially no scar is left after the operation, and the cosmetic effect is good. In this study, we performed this procedure in children with low inguinal cryptorchidism, and the operative duration of this method was significantly shorter than that of the traditional surgery (P<0.05). The scrotal incision is low and small and provides a relatively small field of view. The difficulty of the operation lies in fully releasing the spermatic cord vessels and achieving high ligation or transection of the sheath process. In patients with a high testicular position or older age, the operation is more difficult[22]. Therefore, we chose to apply this operation in cases of low inguinal cryptorchidism. In such cases, if the spermatic cord vessels could not be fully released and the sheath process could not be ligated or transected, the outer ring mouth could be cut at 0.5-1.0 cm to fully release the spermatic cord and ligate or transect the sheath process. In this group, the side of the outer ring mouth was cut in 5 cases, and good results were achieved. Therefore, although testicular descent and fixation through a scrotal incision has the advantages of a short operative duration and good cosmetic effect, its indications should be well understood prior to the operation.
For patients with high inguinal cryptorchidism, laparoscopic testicular descent and fixation was used. This surgical procedure involves no inguinal incision and no inguinal canal incision and thus results in a good cosmetic effect. Additionally, the scope of the laparoscopic exploration is large and clear, allowing determination of the presence and location of the testis (especially in high cryptorchidism) and full freeing of the spermatic vessels to the inferior pole of the kidney. The surgery can be carried out under direct vision, thus reducing damage to the testicular blood supply and ensuring tension-free testicular descent into the scrotum. Although laparoscopic surgery carries the risk of complications, such as intestinal injury, bladder injury and subcutaneous emphysema caused by CO2 pneumoperitoneum, these complications have a low incidence and can be avoided if care is taken during the operation[23-24].
High inguinal cryptorchidism can easily occur with patent processus vaginalis. Due to the difficulty of high ligation, hydrocele or inguinal hernia as complications after surgery are common concerns. A study by Ceccanti S et al. reported that high ligation of the processus vaginalis was not performed for a high-traversing processus vaginalis and that this procedure did not increase the risk of an indirect inguinal hernia or hydrocoele[25]. Handa R et al. demonstrated that the absence of ligatures or sutures in the inner ring orifice during laparoscopic testicular descent and fixation also did not increase in the risk of an indirect hernia or hydrocoele[26]. At our centre, we also did not perform high ligation of the processus vaginalis in cases of a high-traversing processus vaginalis, and there were no cases of hydrocele or inguinal hernia as complications in this study.
The incidence and severity of postoperative complications are important indicators for judging the safety of surgical procedures. Scrotal hematoma was a common postoperative complication that occurred mostly in children who underwent surgery with a transverse scrotal incision for testicular descent and fixation in this study. The main process of creating the scrotal incision is concentrated in the scrotum, which causes greater damage to the scrotal tissue and therefore increases the risk of scrotal hematoma after surgery. Therefore, the operation should be performed gently. Attention should be paid to haemostasis and minimizing pressurize on the scrotum after surgery to reduce the occurrence of scrotal hematoma. There were no cases of testicular atrophy, testicular retraction, inguinal hernia or hydrocele in either group during the perioperative period or at the 1 year follow-up after the operation, and the size of the affected testis improved to varying degrees. There was no significant difference between the two groups, which indicated that the minimally invasive surgery and traditional surgery had good and similar clinical effects.
This single-centre retrospective study had 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.