Tuesday, January 8, 2008
Rupture of the Uterus
Incidence: About 1:4000, 95% of cases occur in multipara particularly grand multipara. Causes: (A) During pregnancy (I) Spontaneous: 1.Rupture of a uterine scar: e.g. previous C.S. especially upper segment, myomectomy, hysterotomy, uteroplasty or perforation. 2. Abruptio placenta with severe concealed haemorrhage. Anterior sacculation in case of incarcerated retroverted gravid uterus or posterior sacculation due to previous ventrofixation of the uterus. 4. Rupture of a rudimentary horn at the 4th - 5th month. 5. Perforating vesicular mole. (II) Traumatic 1. Perforation during vaginal evacuation. 2. External trauma. (B) During labour: (I) Spontaneous: 1. Obstructed labour. 2. Rupture of a uterine scar. 3.Grand multipara: due to degeneration and overthinning of the uterine muscles. (II) Traumatic : 1. Internal version: particularly after drainage of liquor. 2. Manual separation of the placenta. 3. Destructive operations. 4.Extending cervical tear due to e.g. forceps or ventose applications before full cervical dilatation. (III) Improper use of oxytocins. Weak uterine scar may be a result to: 1. Imperfect suture with improper coaptation of the edges. 2.Bad haemostasis results in blood clot formation which prevents good coaptation and predisposes to wound infection. 3. Wound infection. 4. Subsequent implantation of the placenta over it. 5. Upper segment caesarean section scar is weaker than lower segment scar. 6. Repeated vaginal deliveries after a previous C.S weaken the scar . 7. Types: 1.Complete : involving the whole uterine wall including the peritoneum. 2. Incomplete: not involving the peritoneal coat. Sites: It depends upon the cause of rupture. (1) In obstructed labour: - It is usually in lower uterine segment. - Usually oblique or transverse. - More on the left side due to; i) dextrorotation of the uterus. ii) left occipito-positions are more common. - Extended tear may pass laterally injuring the uterine vessels leading to broad ligament haematoma formation. This rupture may involve the ureter or bladder. (2)In rupture scar: At the site of the scar. Clinical Picture: (A) Impending rupture : before actual rupture the following manifestations may be detected: 1- Lower abdominal pain. 2- Tender uterine scar. 3- Vaginal spotting (minimal bleeding). (B) Actual rupture: i) Symptoms: 1.Sudden severe abdominal pain : It is differentiated from labour pain being continuous . 2.If the patient was in labour there is cessation of uterine contractions. 3.Shoulder pain on lying down due to irritation of the phrenic nerve by accumulating blood under the diaphragm. 4.Silent rupture: minimal symptoms may occur in rupture lower segment scar due to presence of fibrosis and minimal internal haemorrhage. ii) Signs 1- General examination: Variable degrees of collapse is present according to amount of blood loss. This may appear postpartum in case of traumatic rupture uterus. 2- Abdominal examination: - Scar of the previous operation. - Foetal parts are prominent and felt easy. - The presenting part recedes upwards. - Abnormal foetal attitude and lie. - FHS usually not heard. - The uterus is felt separated from the foetus . - In incomplete rupture, the foetus still inside the uterus with suprapubic painful tender swelling which is an accumulated blood in the vesico-uterine pouch. 3- Vaginal examination: - The presenting part recedes upwards. - Vaginal bleeding may be present. - Contracted pelvis may be detected. - A cervical tear may be found extending to the lower uterine segment and a broad ligament haematoma may be present. Differential Diagnosis: 1. Abruptio placentae. 2. Disturbed advanced extrauterine pregnancy. 3. Other causes of acute abdomen. Management: (A) Prophylactic: 1.Early detection of causes of obstructed labour as contracted pelvis and malpresentations. 2. Proper use of oxytocins. 3. Version is not done if liquor amnii is drained. 4.Forceps application and breech extraction should not be done before full cervical dilatation. 5.Elective caesarean section for susceptible scars for rupture as upper segment C.S. 6.Exploration of the genital tract after difficult or instrumental delivery. (B) Curative: 1- Blood transfusion and antishock measures. 2- Immediate laparotomy. 3- Deliver the foetus and placenta. 4- Explore the rupture site: - If it is amenable for repair and the patient did not complete her family ® repair is done. - If it is not amenable for repair® hysterectomy. Subtotal hysterectomy is less time consuming so it is done if there is no cervical tear. 5- Exploration of the other viscera mainly the bladder. 6- Internal iliac artery ligation may be needed in case of broad ligament haematoma as the uterine artery is usually retracted and difficult to be identified. 7- Vaginal repair: may be amenable if there is slight extension of a cervical tear with accessible apex. Complications: (A) Maternal: 1- Shock. 2- Haemorrhage. 3- Paralytic ileus. 4- Bladder, ureter or visceral injuries. 5- Infection. (B) Foetal :Death due to asphyxia from detachment of the placenta.