Obstetrics Simplified - Diaa M. EI-Mowafi

Maternal Obstetric Injuries


These include:

  • Rupture of the uterus.
  • Cervical tears.
  • Vaginal tears.
  • Haematoma of the vulva.
  • Perineal tears.
  • Trauma to the pelvic joints and nerves.

Rupture of the Uterus

Incidence

About 1:4000, 95% of cases occur in multipara particularly grand multipara.

Causes

  • During pregnancy
    • Spontaneous:
      • Rupture of a uterine scar: e.g. previous C.S. especially upper segment, myomectomy, hysterotomy, uteroplasty or perforation.
      • 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.
      • Rupture of a rudimentary horn at the 4th- 5th month.
      • Perforating vesicular mole.
    • Traumatic
      • Perforation during vaginal evacuation.
      • External trauma.
  • During labour:
    • Spontaneous:
      • Obstructed labour.
      • Rupture of a uterine scar.
      • Grand multipara: due to degeneration and overthinning of the uterine muscles.
    • Traumatic:
      • Internal version: particularly after drainage of liquor.
      • Manual separation of the placenta.
      • Destructive operations.
      • Extending cervical tear due to e.g. forceps or ventouse applications before full cervical dilatation.
    • Improper use of oxytocins.

Weak uterine scar may be a result to:

  • Imperfect suture with improper coaptation of the edges.
  • Bad haemostasis results in blood clot formation which prevents good coaptation and predisposes to wound infection.
  • Wound infection.
  • Subsequent implantation of the placenta over it.
  • Subsequent overdistension of the uterus e.g. polyhydramnios or multiple pregnancy.
  • Upper segment caesarean section scar is weaker than lower segment scar.
  • Repeated vaginal deliveries after a previous C.S. weaken the scar .

Types

  • Complete: involving the whole uterine wall including the peritoneum.
  • Incomplete: not involving the peritoneal coat.

Sites

It depends upon the cause of rupture.

  • In obstructed labour:
    • It is usually in lower uterine segment.
    • Usually oblique or transverse.
    • More on the left side due to;
      • dextrorotation of the uterus.
      • 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.
  • In rupture scar:
    • At the site of the scar.

Clinical Picture

Impending rupture

Before actual rupture the following manifestations may be detected:

  • Lower abdominal pain.
  • Tender uterine scar.
  • Vaginal spotting (minimal bleeding).

Actual rupture:

  • Symptoms:
    • Sudden severe abdominal pain: It is differentiated from labour pain being continuous.
    • If the patient was in labour there is cessation of uterine contractions.
    • Shoulder pain on lying down due to irritation of the phrenic nerve by accumulating blood under the diaphragm.
    • Silent rupture: minimal symptoms may occur in rupture lower segment scar due to presence of fibrosis and minimal internal haemorrhage.
  • Signs
    • General examination:
      • Variable degrees of collapse are present according to amount of blood loss. This may appear postpartum in case of traumatic rupture uterus.
    • 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.
    • 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

  • Abruptio placentae.
  • Disturbed advanced extrauterine pregnancy.
  • Other causes of acute abdomen.

Management

Prophylactic:

  • Early detection of causes of obstructed labour as contracted pelvis and malpresentations.
  • Proper use of oxytocins.
  • Version is not done if liquor amnii is drained.
  • Forceps application and breech extraction should not be done before full cervical dilatation.
  • Elective caesarean section for susceptible scars for rupture as upper segment C.S.
  • Exploration of the genital tract after difficult or instrumental delivery.

Curative:

  • Blood transfusion and antishock measures.
  • Immediate laparotomy.
  • Deliver the foetus and placenta.
  • 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.
  • Exploration of the other viscera mainly the bladder.
  • 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.
  • Vaginal repair: may be amenable if there is slight extension of a cervical tear with accessible apex.

Complications

Maternal:

  • Shock.
  • Haemorrhage.     
  • Paralytic ileus.
  • Bladder, ureter or visceral injuries.  
  • Infection.

Foetal:

  • Death due to asphyxia from detachment of the placenta.

Cervical Lacerations

Aetiology

  • Forceps, ventouse or breech extraction before full cervical dilatation.
  • Manual dilatation of the cervix.
  • Improper use of oxytocins.
  • Precipitate labour.

Predisposing Factors

  • Cervical rigidity.
  • Scarring of the cervix.
  • Oedema as in prolonged labour.
  • Placenta praevia due to increased vascularity.

Types

  • Unilateral: more common on the left side due to:
    • Dextro-rotation of the uterus.
    • Left occipito-anterior position is the commonest.
  • Lateral .
  • Stellate: multiple tears extending radially from the external os like a star.
  • Annular detachment.

Diagnosis

  • Postpartum haemorrhage, in spite of well contracted uterus.
  • Vaginal examination: The tear can be felt.
  • Speculum examination: using a posterior wall self retaining speculum or vaginal retractors and 2 ring forceps to grasp the anterior and posterior lips of the cervix so the tear can be visualised.

Complications

  • Postpartum haemorrhage.
  • Rupture uterus due to upward extension.
  • Infection: cervicitis and parametritis.
  • Cervical incompetence leading to future recurrent abortion or preterm labour.
  • Ureteric injury: from the extension of the tear or during its repair.

Management

  • Immediate repair: is carried out under general anaesthesia with good light exposure.
    • An assistant applies downward pressure on the uterus while the operator is grasping the anterior and posterior lips in a downward direction.
    • The vaginal walls are held apart with retractors.
    • Interrupted cut gut dexon or vicryl sutures are taken starting from above the apex of the tear to control bleeding from the retracted blood vessels.
    • If the apex is not easily seen a traction on a stitch taken as high as possible in the tear will show the apex.
  • In cases of annular detachment: there is usually no bleeding due to ischaemia at the edges of detachment. Sutures are rarely indicated.

Vaginal Lacerations

Causes

  • Primary lacerations less common and caused by:
    • Forceps application.
    • Destructive operations.
    • Vacuum extraction if the cup sucks a part from the vaginal wall.
  • Secondary lacerations: more common and are due to extension from perineal or cervical tears.

Management

  • Immediate repair: Continuous locked cut gut sutures are taken starting from above the apex to control bleeding from the retracted blood vessels.
  • Tight pack: may be needed to control bleeding from a raw surface area. Foley's catheter should be inserted before packing and both are removed after 12-24 hours.

Haematoma of the Genital Tract

Vulval (Infra-Levator) Haematoma

Causes:

  • Traumatic due to:
    • incomplete haemostasis during repair of episiotomy or tear.
    • Direct trauma as kick or falling down.
  • Spontaneous: due to rupture of a varicose vein.

Clinical picture:

  • The haematoma usually appears 12-48 hours after delivery.
  • The collection of blood is limited by the levator ani above but laterally it may extend to fill the ischiorectal fossa reaching a volume of 500 ml or more.
  • There is a progressive enlarged, painful, tender, tense, bluish swelling at the vulva.
  • Manifestations of hypovolaemia (e.g. hypotension and rapid pulse) and anaemia may be present.

Management:

  • Small not- increasing haematoma: is managed conservatively as it usually resolves spontaneously. Prophylactic antibiotic may be given to guard against secondary infection.
  • Large increasing haematoma:
    • It is incised longitudinally,
    • evacuation of the clotted blood,
    • bleeding points are ligated,
    • the gap is closed in layers.

Vaginal (Supra-Levator) Haematoma

Causes:

Deep vaginal lacerations (see before).

Clinical picture:

  • The blood is collected paravaginally above the levator ani muscle.
  • It may not be visible externally.
  • It may not be painful until reaching a large size.
  • Manifestations of hypovolaemia and anaemia may be present.

Management:

As vulval haematoma.

Broad Ligament (Retroperitoneal) Haematoma

Causes

Upper vaginal,cervical or uterine tears which usually involve the vaginal or uterine artery.

Clinical picture:

  • Hypovolaemia, anaemia or shock: is usually present due to large amount of internal haemorrhage.
  • Swelling on one side of the uterus which increasing over a period of hours or days and may reach up to the lower pole of the kidney or even the diaphragm.
  • The uterus is felt separate and deviated to the opposite side.
  • Fever, ileus and unilateral leg oedema: may develop later.

Management:

  • Small not-increasing haematoma: is managed conservatively as vulval haematoma.
  • Large increasing haematoma:
    • Laparotomy.
    • Incision in the anterior leaflet of the broad ligament.
    • Evacuation of the blood clots.
    • Securing haemostasis, bilateral internal artery ligation or hysterectomy may be indicated.

Perineal Lacerations

Anatomy

The perineal body is a pyramidal mass of tissues about 4´ 4 cm between the lower vagina anteriorly, the anal canal and lower rectum posteriorly.

It is composed of the following layers respectively:

  • Skin.
  • Superficial fascia.
  • Perineal muscles;
    • external anal sphincter, 
    • superficial and deep perinei muscles,
    • bulbocavernosus, and
    • ischiocavernosus.
  • The decussation of the levator ani muscles between the vagina and rectum forms the apex of the perineal body.

N.B. -  All the perineal muscles, except the ischiocavernosus, are inserted in the central part of the perineal body.

  • They contract during intercourse and defecation.
  • During delivery, they may be markedly stretched and teared.

Aetiology

  • Lack of perineal elasticity:
    • Elderly primigravida.
    • Excessive scarring from a previous operation as posterior colpoperineorrhaphy.
    • Friability due to perineal oedema.
  • Marked perineal stretch:
    • Allowing head extension before crowning.
    • Macrosomic baby.
    • Face to pubis delivery.
    • Forceps delivery.
    • Narrow subpubic angle pushing the head backward.
  • Rapid perineal stretch:
    • Precipitate labour.
    • Rapid delivery of the after-coming head in breech presentation.

Degrees

  • First degree: involves the perineal skin, fourchette and the posterior vaginal wall.
  • Second degree: involves the previous structures + the muscles of the perineal body but not the external anal sphincter.
  • Third degree: involves the previous structures + the external anal sphincter.
  • Fourth degree: involves the previous structures + the anterior wall of the anal canal or rectum.

N.B

  • Incomplete perineal tear = 1st or 2nd degrees.
  • Complete perineal tear = 3rd or 4th degrees.
  • Hidden perineal tear: The levator ani muscle is teared without apparent perineal tear predisposing to future prolapse.

Complications

  • Postpartum haemorrhage.    
  • Puerperal infection.
  • Incontinence of stool and flatus in unrepaired or imperfectly repaired 3rd or 4th degree tear.
  • Residual recto-vaginal fistula in imperfectly repaired 4th degree tear.
  • Future genital prolapse. 
  • Dyspareunia due to tender vaginal scar.

Prevention

  • Proper management of second stage of labour.
  • Episiotomy in the proper time.

Treatment

Any perineal tear should be repaired within 24 hours.

  • Incomplete perineal tear:
    • Can be repaired under local infiltration anaesthesia.
      • First degree tear: The vaginal wall is repaired with continuous locked or interrupted sutures and the skin with interrupted sutures.
      • Second degree tear:
        • The perineal muscles are approximated by interrupted chromic cut gut sutures including the torn ends of the levator ani.
        • The vagina is sutured as in the 1st degree tear.
        • The superficial perineal muscles are sutured by interrupted chromic cutgut.
        • The skin is sutured as in the 1st degree tear.
  • Complete perineal tear:
    • Third degree tear:
      • The torn ends of the external anal sphincter is identified and sutured together by interrupted cutgut.
      • The levator ani muscles are approximated in front of the rectum.
      • The vagina, superficial muscles and skin are sutured as before.
    • Fourth degree tear:
      • The rectal wall is sutured by 2 layers of inverted interrupted cutgut not including the mucosa.
      • The external sphincter, levator ani, superficial muscles and skin are sutured as before.

Post-operative care

  • The perineal wound is kept clean and sterile by using antiseptic solution after each micturition or defecation.
  • In the complete perineal tear:
    • Intravenous fluid for 48 hours,
    • clear fluids for the next 24 hours,
    • soft, low residue diet for an additional 48 hours,
    • regular diet after that,
    • laxatives are not used in the first 4-5 days, but stool softeners are allowed.
  • Prophylactic antibiotic is given.

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Edited by Aldo Campana,