Hypospadias is a common congenital malformation of the male lower urinary tract and external genitalia that is autosomal dominant. According to statistics, it accounts for 0.4% to 0.8% of births in male infants.
0.4% to 0.8% of births. Histoplasty suggests that the disease is due to poor integration of the urogenital folds during maternal development, with the external urethral orifice forming a hypospadias below the penis The anatomical features of hypospadias are
1. ectopic external urethral orifice ;
2. downward curvature of the penis;
3. lack of tethering
The formation of the urethra begins in the eighth week of fetal life and is completed in the fifteenth week. Due to the lack of fetal testosterone or its insufficient effect, different types of hypospadias occur at different stages of evolution; and because the urethral groove is gradually closed from the proximal to the distal end, distal hypospadias is more common. Fibrosis of the periurethral corpus cavernosum leads to penile hypospadias.
Clinically, there are five types according to the location of the urethral opening.
(1) Glans type or coronal type: the urethral opening is in the ventral center of the coronal sulcus. This type does not affect the function of urination and sexual intercourse except for the narrower urethral opening, and surgical treatment is not necessary. If you want to emphasize the cosmetic, it is recommended to use surgery to move the urethral opening forward to the normal position;
② Penile type: the urethral opening is on the ventral side of the penis and requires surgical correction;
③ Penile-scrotal type: the urethral opening is at the junction of the scrotum and penis, and the penis is severely curved;
Scrotal type: the urethral opening is located in the scrotum, in addition to the general features of hypospadias, the scrotum is also poorly developed and may have different degrees of dehiscence, and sometimes there is no testicle in it;
(5) Perineal type: The external urethral opening is located in the perineum, the external genitalia are extremely poorly developed, the penis is short and severely hypospadias, and the scrotum is divided and shaped like a female vulva. Urethral hypospadias usually requires surgery, and the goal of treatment is to make the patient’s external genitalia look close to normal, and to be able to urinate standing up and have a normal sexual life in adulthood.
The criteria for success after hypospadias repair are.
① Satisfactory correction of hypospadias deformity;
②The urethral opening is close to the normal position at the head of the penis;
③ Smooth urination;
④No urethral stricture or urinary fistula.
1.Surgical staging
The earliest surgery was performed in two stages, often using the Denis-Browne method, and the success rate reported in China in the 1950s and early 1960s was below 50%.
In 1965, Wu Wenbin et al. used a modified Denis-Browne method to report a success rate of
In 1965, Wu Wenbin et al. used the modified Denis-Browne method to report a success rate of 80% to 90% or more. The two-stage surgery first corrects the downward curvature of the penis in stage I, and the stage II urethroplasty can be performed only after six months. The two-stage procedure adds to the psychological and cost burden of the patient. With the new understanding of the surgical treatment of hypospadias there is a tendency to do a one-stage surgery. This can shorten the treatment period of staged surgery and also reduce the pain and cost of multiple surgeries.
2.Age of surgery, timing of surgery
The timing of surgery for hypospadias is of great importance to the physiological and psychological trauma of the patient, and there is no consensus on whether it should be performed in infancy or before school age. Foreign scholars believe that the ideal age for initial repair of hypospadias is 6 to 18 months, and another age for surgery is 3 to 4 years. These two periods can reduce the physiological and psychological impact of surgery on the child, as well as the psychological burden on the parents. There are also two opinions among domestic scholars:
(1) A few scholars, considering the psychological and penile development of the child, favor corrective surgery in infancy, so that the infant will not be left with adverse effects due to the local deformity.
(2) Most scholars propose to complete all surgeries before school age according to our national conditions, including the interval between staged surgeries and the possible complication management. They believe that the main factors affecting early surgery are anesthesia risk! The tolerance to surgical anesthesia is significantly higher in 3-4 year olds than in infants, which facilitates perioperative management and facilitates successful surgery. However, because of the small penis in young children, surgical operation and care should be more demanding.
However, the failure rate of second-stage urethroplasty is high, and the success rate is only about 50%-70%. Many children have to undergo surgery several times, suffering from physical and mental torture and high financial burden. With the development and improvement of various technologies, early surgery is now advocated, preferably at 6-18 months of age. The success rate of surgery is also gradually increasing.
At the end of 2006, our department took the lead in introducing the “nickel-titanium memory metal urethral stent urethroplasty”, which has achieved a success rate of more than 90% and reached the national leading level. Its advantages are.
(1) All surgeries are completed in one time, which significantly increases the success rate and reduces the number of surgeries;
(2) No suprapubic or perineal fistula is required, which reduces surgical trauma;
(3) Early surgery causes less psychological damage to the child (including psychosexual development and gender confirmation);
(4) Early and successful surgery can also remove the psychological burden of parents as early as possible.
The nickel-titanium urethral stent tube is a spiral spring-shaped stent tube with good stretchability, which can be easily restored to its original shape after pulling and is soft but can be kept in the shape of a tube. At the same time, a smaller diameter silicone tube or urinary catheter can be inserted through the stent tube to the bladder to drain the urine.
The traditional drainage method mainly drains urine from the bladder, but not from the urethra. The existing drainage methods are:
(1) suprapubic cystostomy: Although there is no urine flowing through the urethra to exclude the irritation of urine to the new urethra, but at the same time, due to the edema of the new urethra, the entire urethra is actually in a closed state, similar to a solid organ, once there is fluid, to the distal urethral orifice poor drainage, can only follow the urethra poorly healed local continue to break out, the end is the formation of urethral fistula.
(2) Catheter drainage: The urethra is built with a catheter to drain urine, and since the catheter is placed close to the new urethra and there is no gap between the catheter and the new urethra, once the urethral wound is poorly healed, it is very difficult to drain the secretions out of the urethral orifice through the new urethra and the urethra, and from the mechanical point of view, the local weakness is used to break through, and the result is still the formation of a urinary fistula.
(3) Catheter drainage with side holes: This method is used to flush the new urethra with urine containing antibiotics, and when there is secretion, it can also flow into the urethra through the side holes and be discharged. This is a relatively reasonable way of drainage, but this silicone tube is not stretchable and hard, and the penis is a free end, with erectile function, in this activity, silicone stent tube is easy to damage the new urethra; and silicone tube histocompatibility is poor, easy to cause irritation to the wound; in addition, the density of the side hole is limited, and its drainage effect is also limited.
(4) Perineal fistula, i.e., a small incision is made in the perineum equivalent to the urethral bulb to lead a urinary catheter into the bladder to drain urine, and then a silicone stent tube is led from the fistula to the glans to form a new urethral stent, which is pulled out half a month after surgery. This increases the surgical trauma.
Advantages of using a nitinol urethral stent tube:
①The stent tube is a spiral spring instead of a sealed tube, and when straightened, it is a metal wire. The secretion produced anywhere in the new urethra can be easily drained out through the wall of the stent tube, and even if another urine drainage tube is inserted in the stent tube, the gap between the two walls is sufficient to drain the secretion out of the urethral orifice.
Even if the reconstructed urethra is partially opened or infected for various reasons, the stent tube has good drainage, so that urine and secretions can be discharged smoothly from the urethral orifice, and the local wound will not continue to penetrate deeper due to unobstructed drainage. Since the nickel-titanium urethral stent tube can stay in the body for a longer period of time, it can prevent urethral stricture and ensure that the lateral pressure on the wound at the beginning of healing is not too great due to urethral edema and narrowing of the tube, which may eventually lead to reopening of the newly healed wound. Regardless of the method used to reconstruct the urethra, there is a risk that the wound will not reach stage I healing, resulting in a gaping wound somewhere in the urethra. The role of the nitinol urethral stent is to surface the newly created urethral wound within the penis, allowing the reconstructed urethra to communicate directly with the outside world through the threaded gap in the nitinol urethral stent. Even if the urethral wound is dehiscent, infected, or does not reach stage I healing, it will eventually heal as a scar, just like a wound on the surface of the body, and will not break through to the deeper surface (the surface of the penis) to form a urethral fistula. With the use of a nickel-titanium urethral stent, we basically use a transverse foreskin island flap to reconstruct the urethra,
This simplifies the operation and shortens the operation time. The nickel-titanium urethral stent tube, through its “tube not tube” spiral tube characteristics, allows the reconstruction of the urethra buried in the body of the penis to communicate directly with the outside world, and the reconstruction of the urethra “wound surface”, drainage is reliable, avoiding the occurrence of urinary fistula of the reconstruction of the urethra. The stent tube can be left in place for a longer period of time, thus preventing the occurrence of urethral strictures.