Perineal tear is a severe trauma to the soft tissue between the anus and the external genitalia, resulting in a visible crack in the perineum that is partially puffed up and thinned, or even torn to the anus in severe cases. Causes of perineal tear 1. Labor: delivery of the fetal head is the most important step in the process of delivery. When the fetal head is about to be delivered through the vagina, the vaginal opening and surrounding tissues are compressed due to the continuous descent of the fetal head, and the local puffing and thinning or even shining is visible. 2, dry stool: due to fire or hot weather, the stool is easy to dry, will also lead to perineal tears. 3.Sex life: Because of inflammation, the vagina is prone to dryness and loss of elasticity, and the perineum can be injured or even torn when having intercourse. How to protect the perineum when the fetal head is delivered When the fetal head is about to be delivered, one of the important things that the health care provider must pay attention to during labor is to protect the perineum. If the provider believes that there is a risk of perineal tearing, he or she will perform a lateral perineotomy. After the lateral incision, the midwife can help the fetus to be delivered slowly with the contractions of the uterus, and after the fetus is delivered, the incision will be closed. This can prevent the perineum from tearing and the fetal head from being damaged by prolonged pressure. When the fetal head is delivered, the mother should slow down the delivery speed, too fast will be too late to protect the perineum. When the uterus starts to contract, the mother should do the following steps: 1. bend the legs and separate them; 2. relax the waist as much as possible and do not exert force; 3. relax the limbs and grab the sides of the delivery bed with both hands; 4. open the mouth slightly and breathe with an open mouth; 5. take short and shallow breaths when no force is needed, like after a long run. 6.Listen to the midwife’s command, take a deep breath and hold it when the contraction comes, grasp both sides of the delivery bed with both hands and push hard against the jaw like defecation. Classification of perineal laceration I degree perineal laceration: refers to perineal skin and mucous membrane laceration, including labia and vestibular mucous membrane rupture. II degree perineal laceration: perineal skin, mucosa and muscle laceration, but anal sphincter is intact. Grade III perineal laceration: complete laceration of perineal skin, mucosa, perineal body, and anal sphincter, mostly accompanied by rectal wall laceration. Repair methods There are two common surgical repair methods for complete perineal laceration: (a) layered method The surgical steps are as follows: 1. 2. Scrub the vulva and vagina with soapy water and gauze. Rinse well with water and then rinse the vulva and vagina with Neosporin 1:1000. The rectum is built with gauze rolls to avoid spillage of intestinal secretions, and the vaginal wall can be disinfected with 75% alcohol again before cutting. 3.Expose the surgical field: lay the sterilization sheet to separate the labia minora to both sides and sew on the labia majora and sterilization sheet. 4.Incision: hold the end of the ruptured rectovaginal wall with tissue forceps. Make an incision at the junction of vaginal mucosa and rectal mucosa next to the lateral side of the depression on both sides of the anus, i.e. lateral to the fold of the anal sphincter retracted into the broken end. Trim away the remaining scar tissue. 5. Separate the vaginal and rectal walls: The vaginal wall is pulled with tissue forceps and the vaginal-rectal division is reached with curved blunt-tipped scissors. With the blunt tip facing anteriorly, separate the vaginal wall and rectal wall by holding the blunt tip at the midline while moving upward. The fingers are covered with gauze and peeled upward and to both sides as free as possible, with a wide rectal free surface. Then the tension can be reduced when suturing the rectal wall to avoid cracking at the suture and affecting the healing. 6, repair the anterior rectal wall: the first layer of interrupted sutures with chromium 00 intestinal thread, not through the mucosa. The first stitch is the most important and should be sewn above the top of the wound. The second stitch is at the tip with interrupted sutures, with about 1/2 cm between the two stitches. The second layer is sutured with continuous Lombard’s sutures, starting above the first stitch of the first layer, enhancing and burying the first layer. It is desirable to sew a third layer, including some muscle fibers and connective tissue, to turn the second layer in and push the rectum posteriorly. 7. Finding the broken end of the anal sphincter: The broken end of the retracted anal sphincter can be found in the depression of the anal skin folds. First, reach into the subcutaneous tissue with curved vascular forceps to separate the gap; then reach into this gap with tissue forceps, and strive to hold out the severed end of the sphincter at one time, to avoid several pulls, resulting in damage to the residual few muscle fibers. After finding the severed ends on both sides and traction to the midline, one finger was stretched into the anus to experience the sensation of constriction of the anal finger. The sphincter is sutured with 2-3 stitches of medium silk suture, and the sphincter can be performed later because the outer opening becomes smaller after suturing the sphincter, which affects the internal levator muscle. 8. Symmetrical suturing of the levator muscle. Later attention is paid to the establishment of the perineal body in accordance with the posterior vaginal wall repair. (ii) Mucosal flap method No suture is needed to close the rectal wall, and there is less chance of infection. It has its advantages: if the rectal defect is wider scarred, more layered method is used, and the suture tension affects the wound healing. It is suitable for diseases with short fissures in the rectal wall. For example, if the fissure is long and the mucosal flap that is turned down to cover the fissure needs to be long, it is feared that the blood circulation at the distal end of the fissure is not sufficient as follows: make an inverted V-shaped incision in the posterior vaginal wall, such as the lower end of both sides of the “semicircular” incision, outside the depression of the anal skin fold, reach into the vagina with the index finger of the left hand, and use a tissue forceps to pull the vaginal mucosa outward with the big finger inside the vagina The mucosa of the vagina is pulled outward with the tissue forceps, and the gauze is used to cover the fingers to peel the wall of the vagina down to the end of the fissure. This step must be done carefully to avoid thinning or perforation of the mucosal flap. If the middle of the mucosa is perforated, the previous work is lost and the layered method can only be used again.