Cesarean Delivery & Cesarean Hysterectomy

Chapter 22 Cesarean Delivery & Cesarean Hysterectomy


18 December 1999

1st year resident, Sang-Yun Oh M.D




Cesarean Delivery


- defined as the birth of a fetus through incisions in the abdominal wall laparotomy) and the uterine wall (hysterotomy).

- Not include removal of the fetus from the abdominal cavity in the case of rupture of the uterus or in the case of an abdominal pregnancy
I Frequency

- The rate for cesarean delivery (F22-1)


- The factors that increase cesarean delivery rate


  • Reduced parity

  • Older women are having children

  • Electronic fetal monitoring

  • Breech presentations

  • The incidence of midpelvic vaginal deliveries has decreased

  • Malpractice litigation

  • Socioeconomic and demographic factors

  • Etc ? maternal height, prepregnancy weight, male fetus


II Indications

The four most frequent indications

1. repeat cesarean

2. dystocia or failure to progress in labor

3. breech presentation

4. fetal distress

T22-2



* The rates of cesarean delivery practices for breech, fetal distress,
and “other” are similar across all populations examined.

* The rates of cesarean deliveries for previous cesareans and labor dystocias differ markedly

--> Thus, any reductions in the rate in the United States will most likely come about by more selective diagnoses of labor dystocia and a wider acceptance of vaginal birth after a previous cesarean.

1. Prior Cesarean Delivery




1) Type of Uterine Incision

A. Transverse scars confined to the lower uterine segment

--> minimal risk of symptomatic scar separation during a subsequent pregnancy

-->this risk does not appear to be affected by the route of delivery, the risk of scar separation is 1.8 % with a trial of labor versus 1.9 % for elective repeat cesarean

--> it appears reasonable to encourage a trial of labor in most women
with a low-transverse scar

--> Women with more than one prior cesarean should not be discouraged from a trial of labor (ACOG 1995b)

--> insignificantly increased risk of rupture in women undergoing labor after two prior cesareans compared with one (Asakura and Myers 1995)

--> three-fold increased risk in women with two prior cesarean incision compared with only one (Kornfield 1996)

--> women with multiple cesarean incisions are at risk for hysterectomy because of abnormal placental adherence. Women with repeat cesarean delivery had a three-fold increase of hysterectomy compared with women undergoing primary cesarean section (Case 1996)

B. Low vertical scar confined to the lower uterine segment ? controversial

--> the risk of scar dehiscence was not different from those3 laboring with a prior low-transverse incision (Rosen 1991, Naef 1995)

C. A uterine incision that has extended into the upper contractile portion of the myomentrium is a contraindication to subsequent labor

--> approximately 12 % incidence of symptomatic and often catastrophic rupture during labor

-->these women are delivered by cesarean upon achievement of fetal pulmonary maturity prior to the onset of labor

2) Indication for Prior Cesarean

T22-3



3) Elective Sterilization

- Desire for permanent sterilization in a woman with a prior cesarean is not an indication for a repeat operation

4) Oxytocin and Epidural Analgesia

- No evidence that the use of oxytocin should be modified in a woman laboring with a prior low-transverse incision (ACOG 1995b)

- Less than 10 % of women with scar separation experience pain and bleeding, and fetal heart rate decelerations are the most likely sign of such an event. everal studies attest to the safety of properly conducted
epidural analgesia (Farmer 1991, Flamm 1994)

5) Examining the Scar

- The integrity of the old scar by palpation following successful vaginal delivery

- There is general agreement that surgical correction of a scar dehiscence is necessary only if significant bleeding is encountered.

- Asymptomatic nonbleeding separations do not generally require exploratory
laparotomy and repair

6) Elective Repeat Cesarean Delivery

- Guidelines for timing an elective operation (ACOG 1991)

T22-4


2. Labor Dystocia


- It is meaningless to classify cesarean delivery performed after 8 hours of contractions at 3 Cm dilatation for “failure to progress” in the same category as a woman undergoing cesarean delivery for arrest of descent after 3 hours of pushing with uterine contractions demonstrating 300 Montevideo units

3. Fetal Distress


- The 1970s - the development of electronic fetal heart rat monitoringas well as elegant descriptions of various fetal heart rate patterns and their association with fetal oxygenation and acid-base status
- Management based upon electronic monitoring neither reduces the risk of cerebral palsy, nor improves any measurable indices of newborn outcome compared with intermittent heart rate auscultation (ACOG 1992, 1995b)

- Facilities giving obstetrical care have the capability of initiation a cesarean delivery within 30 minutes of the decision for operation (ACOG 1992). There is no nationally recognized standard of care that codifies an acceptable time interval for performance of cesarean delivery. In most instances, operative delivery is not necessary within this 30- minute time frame.

4. Breech Presentation


- Increased risk of cord prolapse and head entrapment if delivered vaginally
compared with those presenting as a vertex

- With proper selection, certain fetuses may deliver vaginally in breech presentations with minimal risk. But in many of studies, increased death or permanent neurological damage was repeated in the groups delivered vaginally. A significant fourfold increase in both perinatal mortality and traumatic morbidity for planned vaginal versus planned cesarean birth (Cheng 1993)

III Methods to Decrease Cesarean Delivery Rates


- Encouraging a trial of labor after prior transverse cesareans, and restricting cesareans for labor dystocia to women who meet strictly defined criteria

IV Maternal Mortality and Morbidity


- Maternal mortality : 650/100,000 births in 1940 ? 14.1/100,000 birthsin 1988 (Rochat 1988)

- The major sources of operative mortality in women undergoing cesarean delivery

  • Anesthetic accidents

  • Hemorrhage

  • Infection

  • Thromboembolic events

- The factors decreasing mortality

  • Improved anesthetic techniques and training

  • Antimicrobial agents

  • Modern blood-banking techniques

- The relative risk of death for elective cesareans under epidural analgesia was actually lower than that associated with all vaginal births

- Although maternal death is an infrequent sequel of cesarean birth, morbidity is increased dramatically compared with vaginal delivery

- Major morbidity


  • Endomyometritis
  • Hemorrhage
  • Urinary tract infection
  • Nonfatal thromboembolic events


V Birth Trauma


- Numerous reports attest to the occurrence of Erb palsy, skull fractures,and fractures of other long bones in infants delivered by cesarean (Kaplan 1987, Skajaa 1987, Vasa 1990)





Peripartum Management



1. Preoperative Care


- Hematocrit should be rechecked

- Oral intake is stopped at least 8 hours before surgery

- Antacid given shortly before the induction minimizes the risk of lung injury from gastric acid

2. Intravenous Fluids


- Hct of 30 or more and a normally expanded blood volume and extracellular fluid volume most often tolerates blood loss up to 1500 mL without difficulty

- Unappreciated bleeding through the vaginal during the procedure, bleeding concealed in the uterus after its closure, or both, commonly lead to underestimation.

- Blood loss averages about 1 L but is quite variable

- Lactated Ringer solution or a similar solution with 5 % dextrose, 1 to 2 L are infused during and immediately after the operation

3. Recovery Suite


- Must be monitored closely

  • BP, urine flow ( > at least 30mL/hr )
  • the amount of bleeding from the vagina
  • uterine fundus contraction

- Effective analgesics

  • Meperidine 75~100 mg or morphine 10~15 mg, IM or IV

-Encouraging deep breathing and coughing

Subsequent Care



1. Analgesia


- Meperidine 75~100 mg or morphine sulfate 10~15 mg, IM every 3~4 hours as needed for discomfort

2. Vital Signs




- BP, pulse, urine flow, amount of bleeding, and status of the uterine fundus evaluated at least hourly for 4 hours at the minimum

- Thereafter, for the first 24 hours, these are checked at interval of 4 hours

3. Fluid and Diet


- 3L of fluid should prove adequate during the first 24 hours after surgery

- If urine output falls below 30mL/hr, then the woman should be reevaluated promptly. - The cause of the oliguria may range from unrecognized blood loss to an antidiuretic effect from infused oxytocin

4. Bladder and Bowel Function


- The bladder catheter most often can be removed by 12 hours after operation

- In uncomplicated cases, solid food may be offered within 8 hours of surgery

- In most cases of cesarean delivery, adynamic ileus is of short duration. Symptoms include abdominal distention and gas pains, an inability to pass
flatus or stool

--> Treatment : nasogastric decompression, intravenous fluid, electrolyte supplementation, 10-mg bisacodyl rectal suppository

5. Ambulation


- At least the day after surgery, with assistance, should get out of bed

- With early ambulation, venous thrombosis and pulmonary embolism are uncommon

6. Wound care


- Inspected each day

- The skin sutures are removed on the fourth day after surgery

- By the third postpartum day, bathing by shower is not harmful

7. Laboratory


- Hct should be checked

8. Breast care


- Breast feeding can be initiated by the day after surgery

- If not to breast feed, a breast binder that supports the breasts without marked compression will usually minimize discomfort

9. Discharge from the Hospital


- Generally discharged on the third postpartum day

10. Prevention of postoperative infection


- Preoperative skin preparation, with a povidone-iodine scrub is essential to the reduction of postoperative febrile morbidity

- No benefit to the addition of an antibacterial agent to the standard iodine scurb technique (Magann 1993b)

- One or three doses of an antimicrobial given at the time of cesarean delivery were found to decrease infection morbidity appreciably

- Several predictors of prophylactic antibiotic failure

  • The number of vaginal examinations
  • Nulliparity
  • Early gestational age
  • Use of cefazolin

- It is emphasized that the woman with clinically diagnosed chorioamnionitis should be given continuous antimicrobial therapy postoperatively until she is afebrile




Technique of Cesarean Delivery


Type of Uterine Incision

  • 1. Classical vertical incision
  • 2. Lower-segment transverse incision
  • 3. Low-vertical incision

1. Lower Segment Transverse Incision


For a chphalic presentation - most often the operation of choice

Advantages

1) less blood loss

2) easier to repair

3) least likely to rupture with extrusion of the fetus into the abdominal cavity during a subsequent pregnancy

4) does not promote adherence of bowel or omentum to the incisional line

1) Choice of Abdominal Incision

A. Infraumbilical midline vertical incision ? quickest

- Its length should correspond with the estimated fetal size

- Sharp dissection is performed to the level of the anterior rectus sheath

- Expose a strip of fascia in the midline about 2 Cm wide

- Make a small opening and then incise the fascial layer with scissors

- The rectus and the pyramidalis muscles are separated in the midline by sharp and blunt dissection to expose transversalis fascia and peritoneum

- The transversalis fascia and preperitoneal fat are dissecdted carefully to reach the underlying peritoneum

- The peritoneum is incised superiorly to the upper pole of the incision and downward to just above the peritoneal reflection over the bladder

B. The modified Pfannenstiel incision

- The skin and subcutaneous incision is made at the level of the pubic hairline and is extended somewhat beyond the lateral borders of the rectus muscles

- The fascia is incised transversely the full length of the incision

- The superior edges of the fascia are grasped with suitable clamps
and then elevated by the assistant as the operator separates the fascial sheath from the underlying rectus muscles by blunt dissection. The separation is carried near enough to the umbilicus to permit an adequate midline longitudinal incision of the peritoneum.

- The rectus muscles are separated in the midline to expose the underlying peritoneum

- The peritoneum is opened

- Advantage of the transverse skin


  • Cosmetic
  • Stronger with less likelihood of dehiscence or hernia



- Disadvantages

  • Exposure of the pregnant uterus and appendages in some women is not as good

- When a transverse incision is desired and more room is needed, the Maylard incision provides a safe option

2) Uterine Incision

- With thick meconium or infected amnionic fluid, some operators prefer to lay a moistened laparotomy pack in each lateral peritoneal gutter to absorb fluid and blood that escape from the opened uterus

F 22-4



- The loose vesicouterine serosa is grasped with the forceps. The hemostat tip points to the upper margin of the bladder

F22-5



- The loose serosa above the upper margin of the bladder is elevated and incised laterally

F22-6



- Dissection of bladder off uterus to expose lower uterine segment

- In general, the separation of bladder should not exceed 5 Cm in depth and usually less

F22-7



- The myometrium is being incised carefully to avoid cutting the fetal head

- The uterus is opened through the lower uterine segment about 1 Cm below the upper margin of the peritoneal reflection

F22-8



- After entering the uterine cavity, the incision is extended laterally
with either fingers or bandage scissors

3) Delivery of the Infant











4) Repair of the Uterus

- The upper and lower cut edges and each angle of the uterine incision are examined carefully for bleeding vessels

- The uterine incision is closed with one or two layers of continuous 1-0 absorbable suture. Traditionally, chromic suture was used

F22-12



- The initial suture is placed just beyond one angle of the incision.

- A running-lock suture is then carried out, with each suture penetrating the full thickness of the myometrium

- Similar outcomes in the one- versus two-layer closure groups (Chapman 1996)

F22-13



- Serosal edges overlying the uterus and bladder in the past have been approximated with a continuous 2-0 chromic catgut suture

- When both visceral and parietal peritoneum were left open ? reduced need for postoperative analgesia and a quicker return of bowel function (Hull & Varner 1991)

5) Abdominal Closure

2. Classical Cesarean Section


1) Some indications

  • 1) If the lower uterine segment cannot be exposed or entered safely because
    the bladder is adherent densely from previous surgery
  • If a myoma occupies the lower uterine segment
  • If there is invasive carcinoma of the cervix
  • 2) When there is a transverse lie of a large fetus, especially if the membranes
    are ruptured and the shoulder is impacted in the birth canal
  • 3) In some cases of placenta previa with anterior implantation
  • 4) In some cases of very small fetuses, especially presenting as breech,
    in which the lower uterine segment is not thinned out

2) Incisions

- Incision is initiated with a scalpel beginning above the level of the attached bladder

- Once sufficient room is made with the scalpel, the incision is extended cephalad with bandage scissors until it is sufficiently long to permit
delivery of the fetus

- As soon as the fetus has been delivered, oxytocin is administered and the placenta delivered

3) Uterine repair

- One method employs a layer of continuous 1-0 chromic catgut to approximate the inner halves of the incision.

- The outer half of the uterine incision is then closed with similar suture, using either a continuous stitch or figure-of-eight sutures

- The edges of the uterine serosa are approximated with continuous 2-0 chromic catgut



Cesarean Hysterectomy



1. Indications




  • Intrauterine infection
  • Grossly defective scar
  • Markedly hypotonic uterus
  • Laceration of major uterine vessels
  • Large myomas
  • Severe cervical dysplasia or carcinoma in situ
  • Placenta accreta or increta


2. Technique


- Following delivery, the major bleeding vessels are clamped and ligated quickly

- The placenta is removed

- The uterine incision can be approximated with a continuous suture. If the incision is not bleeding appreciably, closure is not necessary

F22-15



- The round ligaments close to the uterus are divided and doubly ligated

- The incision in the vesicouterine serosa is extended laterally and upward through the anterior leaf of the broad ligament to reach the incised round ligaments

F22-16



- The posterior leaf of the broad ligament adjacent to the uterus is perforated just beneath the fallopian tube, utero-ovarian ligaments and ovarian vessels

- Then, these are doubly clamped close to the uterus

F22-17



- The posterior leaf of the broad ligament is divided inferiorly toward
the uterosacral ligaments

F22-18



- The bladder is further dissected from the lower uterine sefment by
blunt dissection with pressure directed towards the lower segment and not
bladder. Sharp dissection may be necessary

- The bladder is dissected free for about 2 Cm below the lowest margin
of the cervix to expose the uppermost part of the vagina

F22-19



- The ascending uterine artery and veins on either side are identified and near their origin are doubly clamped immediately adjacent to the uterus and divided

- The vascular pedicle is doubly suture ligated

F22-20



- The cardinal and uterosacral ligaments and many large vessels the ligaments contain are doubly clamped systematically with Heaney curved clamps and incised and suture ligated

- These steps are repeated until the level of the lateral vaginal fornix is reached

In this way, the descending branches of the uterine vessels are clamped, cut, and ligated

F22-21



- Immediately below the level of the cervix, a curved clamp is swung in across the lateral vaginal fornix, and the tissue is incised medially to the clamp

F22-22



- Each of the angles of the lateral vaginal fornix are secured to the cardinal and uterosacral ligaments

F22-23



- A running-lock stitch is placed through the edge of the vaginal mucosa

F22-24



- Reperitonealization of the pelvis





1. Cesarean section is defined as the delivery of the fetus

through___________________?

2. What steps should be taken if the placenta is encountered in the line of the uterine incision?

3. In cesarean section, what can be done to aid the delivery of an infant whose head is tightly wedged into the pelvis?

4. What type of dosage of analgesia is recommended for the postoperative cesarean section patient?

5. At what intervals should the vital signs of the patient be monitored during the first 24 hours after cesarean section?

6. What are the two major dangers/complications of cesarean hysterectomy?

7. In a total cesarean hysterectomy, what is the advantage of using a running-rock stitch around the vaginal mucosal edge rather than a series of figure-of-eight sutures?

8. What might contribute to the underestimation of blood loss from cesarean delivery?