Pena surgery

Pena surgery is used for the surgical treatment of middle and high rectal and anal malformations. The surgery was designed in 1980 by the Mexican scholar Pena A. He systematically anatomically studied the rectal and anal parts of children with high and medium rectal anal atresia, and clarified the relationship between the external anal sphincter and the levator ani muscle. He pointed out that the anal sphincter system consists of four groups of muscles: the subcutaneous outer sphincter, the proximal levator ani muscle, the deep external sphincter and the muscle complex. The muscle complex is composed of the puborectal muscle part of the levator ani muscle and the deep fibers of the external anal sphincter. These fibers are integral with each other and cannot be separated. The dorsal external sphincter subcutaneous fibers of the muscle complex and the superficial fibers of the external sphincter constitute longitudinal muscle fibers, which terminate in the tailbone. The deep and superficial external sphincters form the upper part of the levator ani muscle. When the levator ani muscle is electrically stimulated, the lower part of the complex undergoes strong contraction, while the superficial and subcutaneous fibers of the external anal sphincter only slightly contracted up and down. In the posterior rectum, the external anal sphincter and the levator ani muscle merge into one body to form a muscle complex. Starting point.

Based on the above understanding, the author proposes a median longitudinal incision through the iliac crest to the perineum, completely dissecting the muscle complex, so that the dragged rectum passes through the center of the muscle complex, and restores the normal anatomical relationship of the rectum and anus. Controlling bowel movements will play an important role.

Treatment of diseases: rectal vaginal fistula

Indication

Pena surgery is suitable for high-middle anal atresia or combined with rectal urethral fistula and recto-vaginal fistula.

Preoperative preparation

1. The position of the blind end of the rectum should be determined before surgery to determine which type of deformity it belongs to. 1 Photograph of inverted pelvic X-ray lateral film: Newborn swallowing air must reach the rectum for more than 12 hours, so the film should be taken 12 to 24 hours after birth, and the inversion time is more than 2 minutes. Anal crypt disposal lead type sign. At the moment of filming, choose the inhalation of the sick child. Attention should be paid to the X-ray projection angle when shooting, generally perpendicular to the film, and the illuminating point is the pubic symphysis so that important anatomical landmarks can be clearly displayed. This test result is often higher than the actual position of the rectal blind end, mainly because the rectal blind end is filled with sticky fetus, sometimes the gas is not easy to reach the apex, and the sick child is crying, the levator ani muscle contraction is large, and sometimes the rectum can be compressed. Blind end retraction. 2 In recent years, the application of B-ultrasound, CT and magnetic resonance imaging (MRI) has been helpful in determining the position of the blind end and estimating the state of the sphincter before surgery. 3 Some people also advocate the use of puncture and suction to determine the position of the blind end of the rectum. The specific method is to use a thick needle to puncture from the anal crypt, while sucking into the needle. Once the fetus is taken out, the depth of the needle is the distance between the blind end of the rectum and the skin. When puncture, it should be noted that the needle angle is inclined from the vertical line of the anus by 5° to 10° to prevent the needle from entering too deep and the needle is too strong to penetrate the bladder or other organs in the abdominal cavity.

2. Conduct a comprehensive physical examination to determine whether there are other system malformations. In particular, attention should be paid to whether congenital malformations such as congenital heart disease, esophageal atresia, and paralysis directly threaten the life of sick children.

3. The urethra should be preserved before surgery as a sign to separate the rectum during surgery to prevent damage to the urethra during free rectum.

4. Preoperative infusion to correct water and electrolyte disorders. For those who have no vomiting without digestive tract obstruction, it is not necessary to infusion.

5. Place the gastrointestinal decompression tube.

6. Prophylactic antibiotics. At the same time, vitamin K1110mg was given, intramuscular injection, 2/d to improve coagulation function.

7. Patients with combined fistula or colostomy should be cleaned before surgery to remove all feces. The blind end can be injected with 1% neomycin solution or metronidazole solution 12 hours before surgery.

Surgical procedure

1. Incision: From the top of the gluteal groove along the median line down to the anal crypt.

2. After cutting the skin, cut the skin with a bipolar electric knife and carefully stop the bleeding. Cut the subcutaneous longitudinal fibers of the external anal sphincter. Longitudinal opening of the tailbone.

3. The incision was retracted with a multi-tooth retractor. Under the guidance of the electrical stimulator, the superanal sphincter and the levator ani muscle were incised from the median longitudinal direction, and the muscle complex was cut downward.

4. Separate the adipose tissue, find the blind end of the rectum, cut the fascia around the rectum, and carefully separate the rectum. If there is a fistula, make 4 support lines at the blind end of the rectum. Cut the rectal wall longitudinally.

5. After cutting the rectal wall, the fistula can be revealed, and a support line can be made on the rectal wall around the fistula, and then the fistula can be removed from the intestinal wall.

6. Fully suture the fistula, then push the peritoneum back.

7. The distal end of the rectum is shaped like a tail. Because the rectal wall is dilated and hypertrophied, it is difficult to pass through the muscle complex. The distal end of the rectum was inverted with a "V" incision, a portion of the intestine wall was removed, and the rectal wall was sutured with a 3-0 absorbable suture or a continuous full layer.

8. The levator ani muscle is sutured to the posterior wall of the rectum, and the formed rectum is placed in the middle of the muscle complex to fix the muscle complex to the intestinal wall. Repair the muscle complex at the back, the superficial and subcutaneous layers of the external anal sphincter.

9. Excision of the excess rectal intestine, suture the distal end of the rectum and the anus, and the anus only retains 1 cm in diameter to prevent rectal mucosal eversion. The normal caliber of the anus is obtained after anal expansion.

complication

1. Loss of urination: The main reason is the extensive dissection of the pelvic tissue. The free rectum should be close to the rectum during surgery.

2. After rectal caudal plastic surgery, rectal fistula or rectal epigas can sometimes occur, especially in children who have not had sigmoid colostomy before surgery. Therefore, before performing this procedure, the sigmoid colostomy should be performed as required to ensure postoperative wound healing and reduce intestinal fistula.

3. Stubborn constipation: Some scholars believe that the rectal caudal plastic surgery and the repair of the muscle complex and the suturing of the levator ani muscle in this operation make the lower rectum wrapped in the muscles too wide, and some patients have stubborn constipation after operation. The method of prevention is that it is not suitable to fix the muscle complex and the levator ani muscle during the operation, and it is not close to the physiological state.

4. Anal stenosis: the anus should be adhered to after surgery.

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