Chapter 74 Cesarean Birth: Surgical Techniques Grainger S. Lanneau, Patrick Muffley and Everett F. Magann Main Menu Table Of Contents Grainger S. Lanneau, Jr, MD Clinical Instructor, Departments of Family Practice/Ob/Gyn, Puget Sound Family Practice Residency, Bremerton, Washington, Ob/Gyn Residency, Madigan Army Medical Center, Tacoma, Washington, Staff, Department of Ob/Gyn, Naval Hospital Bremerton, BREMERTON Washington (Vol 2, Chaps 74, 75) Patrick Muffley, MD (Vol 2, Chaps 74, 75) Everett F. Magann, MD Professor, Department of Obstetrics & Gynecology, University of Western Australia, Perth Australia, Head, Department of Labor & Delivery, King Edward Memorial Hospital, Perth, Australia (Vol 2, Chaps 74, 75, 97) Table of Content: HISTORY EPIDEMIOLOGY INDICATIONS TECHNIQUE SPECIAL SITUATIONS COMPLICATIONS CONCLUSION REFERENCES A cesarean section is the delivery of a fetus through an abdominal and uterine incision; technically, it is a laparotomy followed by a hysterotomy. 1 This definition considers only the location of the fetus and not whether the fetus is delivered alive or dead. Over the past two decades, cesarean delivery has become more commonly used in the United States, and this increase has generated a number of controversial issues, including what constitutes a suitable indication, what is proper technique, and what is the correct terminology to describe the operation known as cesarean section. Legends and myths about the abdominal delivery of an infant appear in many cultures. One of the earliest Greek myths include the birth of Aesculapius, who according to legend, was cut from his mother's abdomen by Apollo, Bacchus, and Jupiter. 2 Legend holds that Julius Caesar was also delivered abdominally. Because very few neonates would have survived an open laparotomy in those times, his mother's survival well into adult life makes the story highly unlikely. It is the birth of Caesar that some authors have attributed to the origin of the term cesarean delivery. 1,3 Another possible source for the term is the Latin verb caedare, meaning to cut, or the term for the children who were born by postmortem cesarean sections, who were called caesones. The Roman law Lex Regis, which dates from 600 BC, required that infants be delivered abdominally after maternal death to facilitate separate burial; this has also been proposed as the origin of the term. The specific law in question was called the Lex Cesare. 4,5 HISTORY Historic records that elude to the performance of cesarean section date back as far as the second and fifth centuries BC and seem to imply that the outcome for both mother and child were favorable. 1 The earliest authenticated report of a child who survived cesarean birth is a document describing the birth of Gorgias in Sicily in approximately 508 BC. 4 There are no other accurate descriptions of the performance of a cesarean section or the immediate outcome of the mother or the neonate until 1610. 1 Gabert and Bey assessed the evolution of the cesarean section by dividing its development into three eras: before 1500, between 1500 and 1877, and from 1878 until the present. 1 Before 1500, references to cesarean section are often clouded in mystery and misinformation, although some religious texts lead us to believe that cesarean sections were performed with the survival of both the mother and the infant. After 1500, the available literature describing delivery by cesarean section and the success of the operation is more plentiful. In 1500, Nufer is reported to have performed the first successful modern cesarean section, with both the mother and infant surviving. The authenticity of this report is doubtful, because it was not documented until 82 years
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Chapter 74
Cesarean Birth: Surgical Techniques Grainger S. Lanneau, Patrick Muffley and Everett F. Magann Main Menu Table Of Contents
Grainger S. Lanneau, Jr, MD
Clinical Instructor, Departments of Family Practice/Ob/Gyn, Puget Sound Family Practice Residency,
Bremerton, Washington, Ob/Gyn Residency, Madigan Army Medical Center, Tacoma, Washington, Staff,
Department of Ob/Gyn, Naval Hospital Bremerton, BREMERTON Washington (Vol 2, Chaps 74, 75)
Patrick Muffley, MD
(Vol 2, Chaps 74, 75)
Everett F. Magann, MD
Professor, Department of Obstetrics & Gynecology, University of Western Australia, Perth Australia, Head,
Department of Labor & Delivery, King Edward Memorial Hospital, Perth, Australia (Vol 2, Chaps 74, 75, 97)
Table of Content:
HISTORY
EPIDEMIOLOGY
INDICATIONS
TECHNIQUE
SPECIAL SITUATIONS
COMPLICATIONS
CONCLUSION
REFERENCES
A cesarean section is the delivery of a fetus through an abdominal and uterine incision;
technically, it is a laparotomy followed by a hysterotomy.1 This definition considers only
the location of the fetus and not whether the fetus is delivered alive or dead. Over the
past two decades, cesarean delivery has become more commonly used in the United
States, and this increase has generated a number of controversial issues, including what
constitutes a suitable indication, what is proper technique, and what is the correct terminology to describe the operation known as cesarean section.
Legends and myths about the abdominal delivery of an infant appear in many cultures.
One of the earliest Greek myths include the birth of Aesculapius, who according to
legend, was cut from his mother's abdomen by Apollo, Bacchus, and Jupiter.2 Legend
holds that Julius Caesar was also delivered abdominally. Because very few neonates
would have survived an open laparotomy in those times, his mother's survival well into
adult life makes the story highly unlikely. It is the birth of Caesar that some authors
have attributed to the origin of the term cesarean delivery.1,3 Another possible source
for the term is the Latin verb caedare, meaning to cut, or the term for the children who
were born by postmortem cesarean sections, who were called caesones. The Roman
law Lex Regis, which dates from 600 BC, required that infants be delivered abdominally
after maternal death to facilitate separate burial; this has also been proposed as the
origin of the term. The specific law in question was called the Lex Cesare.4,5
HISTORY
Historic records that elude to the performance of cesarean section date back as far as
the second and fifth centuries BC and seem to imply that the outcome for both mother
and child were favorable.1 The earliest authenticated report of a child who survived
cesarean birth is a document describing the birth of Gorgias in Sicily in approximately
508 BC.4 There are no other accurate descriptions of the performance of a cesarean section or the immediate outcome of the mother or the neonate until 1610.1
Gabert and Bey assessed the evolution of the cesarean section by dividing its
development into three eras: before 1500, between 1500 and 1877, and from 1878
until the present.1Before 1500, references to cesarean section are often clouded in
mystery and misinformation, although some religious texts lead us to believe that cesarean sections were performed with the survival of both the mother and the infant.
After 1500, the available literature describing delivery by cesarean section and the
success of the operation is more plentiful. In 1500, Nufer is reported to have performed
the first successful modern cesarean section, with both the mother and infant surviving.
The authenticity of this report is doubtful, because it was not documented until 82 years
after the operation was performed. In his book Treatise on Caesarean Section published
in 1581, Roussett advised that the cesarean operation be performed on a living woman;
as such, he was the first physician to do so.4 In 1610, Trautmann performed a well-
documented cesarean section in Wittenberg. Unfortunately, the patient died from
infectious complications on postoperative day 25. In 1692, a patient who had died 14
years after delivering a child by cesarean section underwent autopsy. The accuracy of the claimed cesarean section was validated by finding a well-healed scar on her uterus.
During this time period, the cesarean operation remained crude at best. The abdominal
incision was made lateral to the rectus muscles, and the uterus was incised at
whichever portion was accessible through the laparotomy incision. The uterine
musculature was not reapproximated, and the patient had to be physically restrained during the procedure because anesthesia was not available.1
By the modern era of cesarean section (1878 to present), several modifications were
being made in the cesarean operation. The Porro operation was instituted and became
popular in the United States and England as it became evident that this procedure was
associated with decreased maternal mortality. The operation consisted of a laparotomy
and hysterotomy followed by supracervical hysterectomy and bilateral salpingo-
oophorectomy. The rationale behind this radical cesarean section was that with removal
of the uterus and adnexa, the rates of uterine infection, sepsis, and hemorrhage would
decrease.1,4 Sterility and premature menopause were unfortunate side effects of the Porro procedure.
The first step toward the cesarean operation as it is currently performed was described
by Sanger.6,6A He proposed a procedure that was much less radical and designed to
conserve fertility. His operation did not involve hysterectomy and adnexectomy but
instead consisted of removing the peritoneum from a portion of the anterior uterine wall
and performing a 2-cm-wide wedge resection of the anterior uterine wall. The wedge
was cut so that a thick edge of myometrium was adjacent to the peritoneum and a thin
edge was adjacent to the endometrial cavity. These modifications allowed the serosal
edges to be incorporated into the closure with interrupted silk sutures.1,4 The technique
was further improved on by Garrigues, who did not resect the myometrium but instead
simply closed the uterine incision. Other modifications included not dissecting the
uterine serosa from the uterus and the introduction of silver wire to approximate the myometrium in addition to the interrupted silk sutures on the serosal surface.1
Operative techniques continued to improve during the 18th and 19th centuries.
Cesarean section became a safer operation that could be used at an earlier stage in
difficult labors, and a number of perioperative and intraoperative modifications
emerged. The bladder and the rectum were emptied preoperatively, with catheters and
enemas, respectively, to decrease the volume of these organs in the operative field,
thereby reducing the risk of injury during the surgical procedure. Preoperative
antimicrobial preparation was introduced by Lister in 1876 and included shaving the
operative area and applying antiseptic solutions to the operative field. Vaginal douching was also introduced and routinely performed before performing cesarean deliveries.1
The technique of laparotomy and site of hysterotomy incision were vigorously debated
and modified. Abdominal incisions were made to the right or left of the rectus muscles
or in the midline along the linea nigra. The uterine incision was made vertically in the
midline, obliquely, transversely through the contractile myometrium, laterally 7.2 to 10 cm from the fundus, or on the posterior aspect of the uterus.1
The first report of uterine closure was not until 1769. A number of suture materials were
used to close the uterus, including silver wire, silk, and catgut. Uterine closure was
associated with decreased perioperative blood loss. Early surgeons often sutured the
uterine incision to the anterior abdominal wall to encourage adhesion formation to reinforce the uterus and allow it to tolerate future gestations.1
Closure of the abdominal incision slowly evolved from choosing to leave the wound open
and apply only bandages to allow healing by secondary intention to full closure of the
abdominal wall. However, the proponents of abdominal closure were in disagreement
regarding which layers required reapproximation. Many closed only the skin, whereas others closed all layers. Drainage of the surgical site was also introduced.
Johnson first described a lower segment uterine incision in 1786.1 In 1908, Selheim
suggested that a uterine incision made in the lower uterine segment rather than the
contractile segment of the myometrium would decrease blood loss at surgery and
decrease blood loss in the event of uterine dehiscence.1,4
The development of the modern cesarean operation has not been a recent
accomplishment but instead represents a series of innovations over many centuries of
trial and error. Many aspects of the operation as it is commonly performed today are
not based on randomized trial or techniques that have been proven to be superior by
rigorous study, but instead are the culmination of many years of trial and error.
EPIDEMIOLOGY
In 1965, the total cesarean rate in the United State was 4.5%.7 By 1988, the cesarean
rate had increased to an all-time high of 24.7% and accounted for more than 965,000
live births that year. The cesarean rate continues to fluctuate and was 24.49% in
2001.8 The high incidence of cesarean delivery has caused a great deal of debate over
the past several years among health care providers, third-party payers, and health
policy developers. The questions debated include what is an appropriate cesarean rate,
are cesareans necessary for optimal patient care, and how should the cost of abdominal
delivery be addressed (Fig. 1)?
Fig. 1. Total and primary cesarean rate and VBAC rate in the
United States from 1989 to 2001. (Macdormon MF: Annual
Summary of Vital Statistics, Pediatrics 110:1037–1052, 2002.)
The vaginal birth after cesarean (VBAC) rate in 1985 rate was 6.6 per 100 deliveries by
women with a previous cesarean section. The VBAC rate increased 33% between 1991
and 1996 (from 21.3 to 28.3 per 100 births to women with a previous cesarean) but
then decreased 17% between 1996 and 1999 (to 23.4 per 100 births). The dramatic
increase in VBAC rates between 1991 and 1996, followed by its subsequent decrease,
was experienced by women of all ages and for each major race/ethnicity group. The
VBAC rate in 1993 had increased to 25.4 per 100 deliveries by previous cesarean
patients.9 These increases in the cesarean section rate were the impetus for a number
of investigators to assess the causes of these trends and to search for possible methods
to decrease the cesarean birth rate.8 The Healthy People 2000 Work Group
recommended a target national cesarean delivery rate of 15% for the year 2000
(including the specific targets of 12% for primary [first time] cesarean deliveries and
65% for repeat cesarean deliveries among women who had a previous cesarean
delivery); it is evident that this goal was not met. A Department of Health and Human
Services expert working group on cesarean delivery rates, which included ACOG
representatives, discussed the Healthy People 2010 objectives and developed evidence-
based cesarean delivery rate goals for the year 2010. The National Center for Health
Statistics (NCHS) has determined the cesarean delivery rates for two major categories
of patients from 1996 birth certificate data. Target cesarean delivery rates determined
by the expert working group were based on the 25th and 75th percentiles of state
ranking for these two categories. Targets for the two major categories should be set at
the 25th percentile for primary cesarean delivery rates and the 75th percentile for VBAC
rates. The task force has adopted 1996 rates to be consistent with NCHS and the expert working group rates, but uses 1997 national vital statistics elsewhere in this report.
The expert working group proposes the following cesarean delivery rate benchmarks:
nulliparous women at 37 weeks of gestation or greater with single fetuses with vertex
presentations, the national 1996 cesarean delivery rate for this group was 17.9%; the expert working group goal at the 25th percentile for this group is 15.5%.
Multiparous women with one previous low-transverse cesarean delivery at 37 weeks of
gestation or greater with singleton fetuses with vertex presentations: The national 1996
VBAC rate for this group was 30.3%; the expert working group goal at the 75th percentile is 37%.
Cesarean section and VBAC rates differ among geographic regions, demographic
populations, and third-party payer sources. For example the cesarean section rate
continues to be highest in the southern and northeastern United States compared with
the West and the Midwest. Conversely, the VBAC rates tend to be lowest in the southern and northeastern regions of the United States8,9 (Figs. 2A and 2B).
Fig. 2. A. State ranking of cesarean delivery rates
in the United States in 1997 (Ventura SJ, Martin
JA, Curtin SC et al: Births: Final data for 1997.
Natl Vital Stat Rep 47:1–84, 1999). B. State
ranking of VBAC rates in the United States in
1997. VBAC indicates vaginal birth after cesarean
delivery. (Ventura SJ, Martin JA, Curtin SC et al:
Births: Final data for 1997. Natl Vital Stat Rep
47:1–84, 1999.)
Fig. 2. Continued.
The rate of cesarean delivery was also increased in women older than age 35 years, in
hospitals with more than 500 beds, in for-profit hospitals, and in patients with private
insurance.10 The cesarean section rate in the United States, when compared with that in
other developed countries, is the among the highest in the world.10,11
Several authors have examined the incidence of cesarean section by indication. An
analysis of cesarean deliveries at the University of Vermont by Pollard and Capeless
revealed the that the total cesarean section rate was 14.4% and the primary cesarean section rate was 11.4%.12
Abnormal presentation and dystocia were the major indications for cesarean delivery. A
much smaller proportion was performed for nonreassuring fetal surveillance, failed induction, and 25% for other indications.
Repeat cesarean deliveries account for a large percentage (37%) of the cesarean
sections in the United States.9 It is believed that through both patient and health care
provider education, the number of repeat cesarean sections can be reduced. VBAC
success rates in excess of 70% have been reported in diverse populations with the
implementation of an aggressive VBAC policy. Strategies to improve VBAC rates might
include educating women about the risks for complications and benefits of VBAC,
ensuring careful selection of VBAC candidates, developing guidelines for management of
labor, and educating health care providers about reducing VBAC risks.5 Further work is
required to encourage patients and physicians to accept this alternative to repeat
cesarean delivery. The indications, contraindications, and predictors of success for VBAC
are discussed later in this chapter.
The diagnosis of dystocia is another important contributor to the high rate of cesarean
delivery. In 1995, Pollard and Capeless found that more than 35% of cesarean sections
in their institution were performed for either arrest of dilation or arrest of
descent.12 Diagnoses such as dystocia, cephalopelvic disproportion, and failure to
progress are unacceptably vague and do not reflect the true reason why the labor is not
progressing as anticipated. An accurate recording of the reason that labor has not
progressed should include the adequacy of the maternal pelvis, the fetal size and
position, and strength and frequency of the uterine contractions. To more thoroughly
evaluate the cause of the dystocia, an attempt to achieve active-phase labor should be
undertaken. It is important to note that a primary cesarean section for dystocia occurs
primarily in first labors, it is a relatively uncommon event in parous patients,13 and also
that the majority of repeat cesarean operations result from primary cesarean deliveries
for dystocia.13 Therefore, the thorough evaluation of patients with evidence of dystocia
in labor and the exhaustive search for the underlying cause, with reasonable attempts to alleviate correctable problems, could significantly impact the cesarean section rate.
Fetal malpresentation currently accounts for approximately 3% to 4% of cesarean
sections in the United States.13 Because of the International Term Breech Trial,
cesarean section is routinely offered to nonvertex infants. Because of these changes,
external cephalic version has emerged as a realistic means of correcting fetal
malpresentations prior to labor and therefore avoiding an unnecessary abdominal
delivery.14,15,16 The ACOG defines dystocia as difficult labor or childbirth resulting
from abnormalities involving the cervix and uterus, the fetus, the maternal pelvis, or combinations of these factors.17
Fetal intolerance of labor contributes minimally to the overall cesarean rate. However,
the cesarean section rate has increased with the widespread use of electronic fetal
monitoring.18,19,20,21,22 The use of centralized fetal monitoring increases the cesarean
rate even more.23 Because of the well-documented low specificity of a nonreassuring
fetal heart rate pattern, further assessment by other diagnostic means should be
undertaken in all but the most pressing cases. Fetal heart rate acceleration with scalp
stimulation or a normal scalp pH in the fetus with repetitive late decelerations is
reassuring of fetal well being. Scalp pH, which is time consuming and may be difficult to
obtain, may be replaced by a newer technology. Fetal pulse-oximetry is currently used
in Europe but has failed to become a standard of care in this country pending a more
thorough evaluation of its benefit.24
A number of other programs have been implemented at various institutions in an
attempt to reduce the cesarean section rate. A labor-adjusted cesarean rate has been
proposed as a more accurate indicator of the appropriateness of the rate of cesarean
section than raw numbers and rates.25 This labor-adjusted rate excludes patients who
are determined not to be candidates for vaginal delivery by a reasonable
physician standard. For example, excluded patients would include women with a history
of classical cesarean section, proven pelvic inadequacy, invasive cervical malignancy,
suspected ruptured uterus before labor, maternal disease that may be life-threatening
because of the physiologic changes involved in labor, macrosomia, macrocephaly, funic
presentation, monoamniotic twins, and nonreassuring fetal heart rate on antenatal
surveillance. In one population in which the labor-adjusted rate was studied, the
adjusted cesarean rate was almost one third of the raw cesarean rate.
Peer review committees have also been established in many hospitals to evaluate
cesarean section indications and rates.25 Although the institution of a peer review
process for cesarean deliveries has not been shown to significantly decrease the
cesarean section rate, it remains an excellent method of evaluating and adjusting
medical practice within a hospital community.
INDICATIONS
Indications for cesarean delivery vary depending on the clinical situation, resources
available for patient care, and individual physician management techniques. There are no
definitive algorithms available to the practicing obstetrician to direct when an abdominal
delivery will benefit the mother and/or the fetus in every clinical situation. The decision to
perform an abdominal delivery remains a joint judgment between the physician and
patient after carefully weighing the pros and cons of a cesarean delivery versus continued labor and/or operative or spontaneous vaginal delivery.
Primary Cesarean Section and Repeat Cesarean Section
Primary cesarean section is the delivery of the fetus through the maternal abdomen in a
gravida who has not previously undergone a cesarean delivery. Repeat cesarean section
refers to the gravid who refuses trial of labor or who is not a candidate for vaginal
delivery. Common indications for repeat cesarean deliveries include complete placenta
previa, breech presentation, fetal lie other than longitudinal after failed external cephalic
version, nonreassuring fetal assessment that cannot be further evaluated, clinically
proven inadequate maternal pelvis, and severe preeclampsia hemolysis, elevated liver
enzymes, and thrombocytopenia (HELLP) syndrome that is clinically worsening and is
remote from delivery, cervical cancer, obstructing fibroid, and acquired immune
deficiency. Indications for cesarean delivery can be divided into indications that are of
benefit to the mother, the fetus, or both.
Indications for cesarean delivery for maternal benefit include any situation in which it is
inadvisable to continue to strive for a vaginal delivery out of concern for maternal
outcome. In these situations, the gravida undergoes a major abdominal operation for indications that are likely to decrease her risk for morbidity and/or mortality.
In contrast, when a cesarean section is performed for fetal indications, the mother is
undergoing major abdominal surgery when there is no immediate benefit to her but there
is potential benefit to the neonate. In these situations, fetal health would be
compromised if further efforts toward vaginal delivery are pursued. Indications for
time available to deliver the infant, and skill of the surgeon. Midline vertical incisions are
generally more hemostatic and require less dissection; therefore, less time from incision to
birth than transverse incisions. Transverse incisions fall along the lines of expression of the
anterior abdominal wall and therefore should create less pronounced scarring and risk of dehiscence. Transverse incisions have also been associated with less postoperative pain.
Fig. 3. Abdominal incisions. A. Pfannenstiel incision
should be made in a curvilinear fashion
approximately 2 cm above the pubic
symphysis. B.Joel-Cohen incision should be made
in a linear fashion approximately 2 to 3 cm above
the traditional placement of the Pfannenstiel
incision. C.Midline vertical incision should be made
in the midline and extend from just below the
umbilicus to just above the symphysis pubis and
may be continued around the umbilicus if more
exposure is necessary. D. Wiser (right
paramedian) incision should be made several cm
to the right side of the umbilicus and somewhat
higher than the normal midline vertical incision.
TRANSVERSE INCISIONS
Although transverse incisions are commonly performed because of the widely held belief
that there is a decreased incidence of wound dehiscence and incisional hernia and greater
cosmetic appeal, more recent studies have not supported this belief and point to infection as
the greatest risk for dehiscence regardless of incision type.30,31,32 The Pfannenstiel incision is
made transversely in the maternal abdomen approximately 3 cm above the symphysis pubis
and is curvilinear, with the lateral apices of the incision smiling up toward the anterior
superior iliac spines (see Fig. 3). This incision is performed sharply to the level of the
anterior rectus fascia. The anterior rectus fascia is then sharply incised with the scalpel in a
transverse manner in the midline to expose the belly of the rectus muscle on either side of
the midline. At this time, the incision in the anterior rectus fascia may be extended laterally using either the scalpel or the Mayo scissors.
Care must be taken not to cut the underlying rectus muscles. This may be accomplished by
placing the Mayo scissors, with the tip up, underneath the fascia, and then sliding the
scissors laterally along the length of the proposed fascial incision, opening the blades of the
scissors at the proposed apex of the incision and withdrawing the scissors before closing the
blades. At this point, the Mayo scissors can be used to extend the fascial incision laterally by
merely pushing the blades of the scissors against the fascia. Care should be taken to avoid
the transverse oblique muscle when incising the fascia. After the fascia is incised, the
anterior rectus fascia can then be dissected from the underlying rectus muscles in both the
cephalad and caudad directions. This is accomplished by grasping the cut edges of the fascia
with a pair of strait Kocher clamps and using a combination of blunt and sharp dissection to
free the muscle from the overlying fascia. This dissection allows the rectus muscles to be
retracted laterally without being cut. During this dissection, care must be taken to identify
and ligate or electrocoagulate the perforating vessels between the rectus muscles and the
anterior fascia; this can be performed at entry, or in the event of an emergency cesarean
delivery, at the time of closure. The posterior sheath consists of the fascia of the
transversalis muscle and is closely opposed to the peritoneum. These tissues may be incised
in either a longitudinal and transverse manner. Regardless of which manner is chosen, the
entry point should be high in the operative field to avoid injury to the maternal bladder.
Sharpening of the peritoneum may be performed by elevating the peritoneal membrane
between two hemostats, palpating the opposing pieces of membrane for evidence of
entrapped bowel, and making circumcision with a scalpel or by bluntly introducing a finger
through the peritoneum at the level of the umbilicus. Once the peritoneal cavity is entered,
the peritoneal incision is extended using Metzenbaum scissors to maximize surgical
exposure, with care being taken to avoid inadvertent damage to the bladder or to any bowel or omentum that may be adherent to the anterior abdominal wall.
The Maylard and Cherney incisions differ from the Pfannenstiel incision in the manner in
which the anterior rectus sheath and the rectus muscles are approached. With the Maylard
incision, once the anterior rectus sheath is incised in a transverse fashion, the fascia is not
dissected free from the underlying rectus muscles; instead, the inferior epigastric arteries
are identified and ligated, and the rectus muscles are incised, usually with electrocautery to
minimize bleeding. The posterior rectus sheath and the peritoneum are then incised in a
The Cherney incision is performed in the same manner as the Pfannenstiel and the Maylard
incisions except that the rectus fascia is not entered; instead, the rectus muscles are cut
free from the symphysis pubis at their tendinous insertion and reflected superiorly. There are few if any indications for the use of this type of incision for an abdominal delivery.
The Joel-Cohen incision is performed in a transverse manner several cm above the location
of a Pfannenstiel incision and is linear, not curvilinear. The fascia is not dissected off of the
rectus muscles, and the peritoneum is entered transversely, as in the Maylard incision. An
advantages of this type of incision include decreased operating time, however there are no maternal or fetal advantages other than speed.33,34
In the moderately obese patient, a variation of the Pfannenstiel incision is performed several
cm higher than the true Pfannenstiel to avoid placing the incision in the fold created by the
abdominal pannus and thereby decreasing the rate of wound complications.
VERTICAL INCISIONS
Historically, the midline vertical skin incision has been the preferred incision for cesarean
section because of the speed and ease of entry into the peritoneal cavity. The decreased
dissection that is required reduces intraoperative blood loss. Vertical incisions remain useful
in situations such as cesarean section for fetal bradycardia and in the morbidly obese
patient in whom a transverse incision may not allow for adequate exposure of the operative
field. The incision is performed vertically from just below the umbilicus and extended to just
above the symphysis pubis and can easily be extended around the umbilicus if exposure of
the upper abdomen is required. When making a midline vertical incision, it is important to
remember that the linea nigra may not represent the true midline. The incision is carried
sharply down to the level of the rectus sheath, which is then incised sharply with the scalpel
in a vertical direction. This incision may be completed with the scalpel or by using the Mayo
scissors. The fascial edge closest to the midline is then grasped with a pair of Kocher
clamps, and sharp and blunt dissections are used to separate the rectus muscles from the
overlying fascia. The rectus muscles are then separated in the midline, and the peritoneum is entered vertically as described previously.
A right paramedian incision is useful in the morbidly obese patient in whom the abdominal
pannus is grossly displaced when the patient is placed in the left lateral tilt position.
Advantages of this incision are that once the skin has been incised, an incision that is
continued perpendicular toward the floor of the operating room will incise the fascia
approximately in the midline of the patient, resulting in better exposure for the delivery of
the infant.
Repeat cesarean delivery account for the majority of cesareans. In patients undergoing
repeat cesarean delivery, the abdominal scar may be revised at the time of repeat
operation. In the case of an emergency cesarean section, any scar revision should be
performed at the time of abdominal closure and not at entry. It is also important to
remember that the choice of skin incision should be that which the primary surgeon believes
will be most beneficial for the present operation and should not be dictated by the location of a previous scar.
Uterine Incisions
There are three standard uterine incisions that can be performed for delivery of the fetus:
low transverse, low vertical, and classical (Fig. 4). The specific type of uterine incision
should be determined by the primary surgeon at the time of the operation based on gestational age and lie of the fetus and any uterine anomalies.
Fig. 4. Uterine incisions. A. Low-transverse uterine incision should be made through the
thin, noncontractile portion of the lower uterine segment in a curvilinear fashion. Also
pictured is a low-vertical incision, which is made through the noncontractile lower uterine
segment in a vertical fashion. B. J-extension of the low-transverse incision. When
additional exposure to the uterine cavity is required to deliver the fetus, the low-transverse
incision can be extended laterally and cephalad to increase the length of the incision
without endangering the uterine arteries. C. Another option in this situation is to use a T-
extension in the midline. D. The classical uterine incision is made through the contractile
portion of the myometrium above the bladder reflection.
Historically, the creation of a bladder flap was advocated before making any uterine
incisions. More recently, randomized controlled trials have noted that the omission of the
bladder flap provides short term advantages such as reduction of operating time and
Fig. 8. Single-layer repair of the low-transverse uterine incision. To
obtain optimal hemostasis of the incision in a single layer, the surgeon
should be careful to include all layers of incised myometrium while
taking care to avoid including excess decidua and serosa.
Uterine closure may be performed with either a single- or double-layer closure technique.
Single-layer closure using a running locking stitch (Fig. 8) has been shown to be associated
with decreased operative time and fewer additional hemostatic sutures. A large Canadian
study found a four-fold increase in the risk of uterine rupture in woman who had a single layer closure in their previous pregnancy.43,44,45,46,47
Chromic catgut has been the suture of choice for closure of the uterine incision by many
obstetricians for a number of years. However, the use of a synthetic absorbable suture, such
as polyglycolic acid or polyglactin, has several advantages over the use of catgut. The
method of absorption of catgut suture is by phagocytosis, and this results in significantly
more inflammation than the absorption of synthetic sutures by hydrolysis.48 The decreased
inflammation associated with synthetic absorbable sutures, as well as the increased time interval to the loss of suture strength, are both advantageous in this situation.
After the uterus is closed and has been returned to the peritoneal cavity, irrigation can be
employed. Routine irrigation in low-risk populations does not reduce intrapartum or
postpartum maternal morbidity.49 Next, attention should be turned to ensuring that the
operative field is hemostatic, with special attention given to the uterine incision and bladder
flap, if these have been previously placed on tension because of exteriorization of the
uterus, and to the rectus muscles. Hemostasis may be achieved by either suture ligation or
electrocoagulation of bleeding points. There is no advantage to closure of the visceral or
parietal peritoneum. When repaired with suture, the peritoneum undergoes more
inflammation and scarring in animal models.50 Operating time and postoperative analgesia
requirements are reduced in patients who do not undergo closure of the visceral and parietal
peritoneum. There is also a decrease in adhesions found at repeat operation when the visceral and parietal peritoneum is not closed.51
Fascial closure in a Pfannenstiel incision is performed in a single layer with a synthetic
absorbable suture. In patients who have undergone more than one laparotomy through the
same scar, or in patients who are at increased risk for fascial separation or dehiscence such
as diabetic patients or patients who are on chronic corticosteroids, the use of a synthetic
delayed absorbable suture such as polydioxanone may be preferable because of its ability to
maintain suture strength for a longer period of time.52 For the closure of a vertical fascial
incision, a continuous running delayed absorbable suture has been shown to be as effective
as the Smead-Jones closure and to reduce operating time without increasing morbidity.
Whenever sutures are placed within the fascia, it is important to remember that a 10-mm
zone of collagenolysis occurs surrounding the incision; therefore, sutures should be placed
more than 1 cm from the fascial edge to achieve maximal wound strength.53
The subcutaneous tissue may be closed with an absorbable suture or simply reapproximated
by closure of the skin. Closing this layer has not been associated with decreased rates of
superficial wound disruption in several studies.54 Skin closure may be accomplished by
either a subcuticular stitch or staples. Subcuticular stitch has been associated with less
immediate postoperative pain and more cosmetically appealing at 6 weeks when compared to the stapling device.55
Postoperative Care
There is little literature to support any specific postoperative regimen in postcesarean
patients; however, common sense and extrapolation of data from other postlaparotomy
patients allow for the development of a rational plan of care. Most cesarean sections are
relatively uncomplicated, and in these patients, care should be similar to that given after a vaginal delivery.
In the first hour after cesarean section, the patient should be monitored closely in a
recovery area where urine output, pulse, blood pressure, respirations, and any evidence of
bleeding can be closely observed; if the patient remains stable and without complication, she may then be transferred to the postpartum ward.
Once any nausea and vomiting has abated, the patient should be encouraged to take fluids
orally. This may be followed by oral intake of solid food as soon as the patient feels that she
is ready; this should occur no later than the first postoperative day. Early institution of
feeding in the postsurgical patient with minimal intraoperative bowel manipulation does not
increase the incidence of postoperative ileus.56
Early ambulation should also be encouraged. Getting the patient out of bed as soon as
regional anesthesia has worn off or as soon as she has recovered from general anesthesia
will decrease the incidence of pulmonary complications such as atelectasis and pneumonia
and the incidence of thrombotic complications. This will also facilitate the removal of bladder
catheters, therefore decreasing the incidence of catheter-associated urinary tract infections.
In the uncomplicated patient with adequate urine output, the catheter should be removed
no later than the first postoperative day. Encouragement of deep breathing and coughing
with the use of incentive spirometry will also help prevent collapse of alveoli in the lung and resulting infection.
Routine laboratory studies are probably unnecessary in most postcesarean patients who
have no unexpected symptoms. However, a single hemoglobin determination on
postoperative day one or two is probably reasonable to screen for significant anemia. Most
postpartum patients with asymptomatic anemia respond well to oral iron therapy.
The wound should be cared for in the standard manner, with occlusive dressings removed
on the first postoperative day and the wound examined daily during the hospitalization for
evidence of infection, seroma, or hematoma. Skin staples can be removed on the second or
third postoperative day with Pfannenstiel incisions and at the fifth to seventh postoperative
day with vertical incisions. The placement of SteriStrips after staple removal may help maintain skin edge approximation with earlier removal.
The patient may be discharged when she is able to care for herself and her newborn. Many
patients are ready to leave the hospital by postoperative day two or three. Discharge
instructions should include patient education concerning expectations on activity level,
lochia, breastfeeding or milk suppression, contraception, and newborn care.
SPECIAL SITUATIONS
Vaginal Birth After Cesarean Section
VBAC has become less common in the United States, and between 1996 and 1999 the rate
decreased by 17 % to 23.4 %.7 The VBAC rate is defined as the number of vaginal births
to women with a previous cesarean section per 100 deliveries to women who had a
previous cesarean delivery. In 1999, the United States VBAC rate was 23.4.7 Since the
early 1980s, a number of reports have shown that vaginal delivery after a previous low-
transverse or low-vertical cesarean section is safe for both the mother and the
fetus.39,60,61 However, more recently the safety of VBAC has come under closer scrutiny.
Despite literature supporting the practice, most generated in university and tertiary-level
centers, there have been no randomized trials to prove that maternal and fetal outcomes
are improved by VBAC over repeat cesarean section. There have even been reports to
indicate that there are maternal and infant complications associated with an unsuccessful trial of labor.57,58,59 These facts demonstrate the need for a continued study in this area.
In properly selected patients, the success rate for trial of labor is between 60% and
80%,60,62,63,64 which is not grossly different from the vaginal delivery rate of the entire
obstetric population in the United States in recent years. A successful trial of labor is less
likely in patients who have not had a previous vaginal delivery, have a history of
dysfunctional labor, have nonreassuring fetal surveillance, undergo induction of labor, have
a fetus with evidence of intrauterine growth restriction, or have fetal–pelvic disproportion.65
Several authors have attempted to predict which patients are more likely to undergo
successful VBAC by various historic parameters and the physical examination at the time
of admission for delivery. Jakobi and colleagues66 found that previous cesarean section
performed for a nonrepetitive indication such as breech presentation, history of a previous
successful VBAC, station of −1 or more, unruptured membranes at admission, and dilation
of 4 cm or more at admission were all positively correlated with increased likelihood of
successful VBAC. A history of previous cesarean section for arrest of labor was significantly
associated with an increased risk of unsuccessful trial of labor. Using these criteria
retrospectively, the authors would have correctly predicted the success of a trial of labor in
more than 94% of candidates but would have correctly predicted failure of trial of labor in
Flamm and Geiger67 examined similar data to develop a scoring system in an attempt to
predict the success of trial of labor. These authors found that maternal age younger than
40 years, indication other than failure to progress, cervical effacement of more than 75%
on admission, and cervical dilation of more than 4 cm at admission were all significantly
correlated with increased success of trial of labor. When these factors were weighted and
placed in a scoring system in an attempt to predict the success of attempted VBAC, the
authors found that as the number of these factors increased, the likelihood of successful
trial of labor increased. Patients with only one or two of these characteristics had a 49% to
59% success rate, whereas patients with four or more of these characteristics had a
greater than 90% success rate. The ability to more accurately predict the likely success of
trial of labor is clinically useful, because there is increased maternal morbidity is associated
with a failed trial of labor.68 These women have an increased risk of operative injury, infectious morbidity, and uterine rupture.
Morbidity associated with VBAC has been well established. Uterine rupture occurs in
approximately .3% to 1.5% of trials of labor with a low-transverse scar.69,70,71 The uterine
rupture rate is 1% to 7% with a low-segment vertical scar. The incidence of uterine
rupture may be increased in patients with a previous single-layer closure.72,36 However, in
patients with a previous classic uterine incision, the risk of uterine rupture may be as high
as 9%, with one third of these occurring before the onset of clinical labor.74 In patients for
whom documentation of the type of previous uterine incision is not available, there is no
increased risk of uterine rupture.73 More than one previous low-segment uterine incision is
not a contraindication to trial of labor.75
In the event of uterine rupture, fetal mortality and morbidity is excessive. When a classic
uterine incision ruptures, the fetal mortality is in excess of 50%, compared with 12% in the event of rupture of a prior low transverse incision.76
In evaluating a patient as a candidate for trial of labor, it is important to consider the
patient's history and physical examination, the patient's wishes concerning elective repeat
cesarean section versus trial of labor after appropriate counseling, and the environment
where the trial of labor is to be performed. Most studies that established the safety of
VBAC were conducted in tertiary care centers or teaching institutions.75 The availability of
operating room staff and anesthesia support in the event of uterine rupture or
nonreassuring fetal monitoring in these settings may vary considerably in private and small community hospitals.
After the patient has been appropriately counseled and has consented to a trial of labor,
labor management should not significantly differ from the management of a patient with
an unscarred uterus. Cervical ripening, oxytocin augmentation,73,77 and regional anesthesia78,79,80,81 may be used as clinically indicated with close monitoring of the patient.
Population-based studies have demonstrated the increased morbidity (uterine rupture
rates of 24.5/1000) associated with the use of prostaglandin cervical ripening agents in a
scarred uterus. This prompted ACOG to release a committee opinion discouraging their use
for the purpose of induction during VBAC attempts.82,83
Perimortem Cesarean Section
One of the first indications for cesarean section was for the delivery of the fetus in the case
of maternal death. Currently, the performance of a rapid cesarean delivery in the event of
sudden maternal cardiac arrest can be lifesaving for the fetus. In the event of maternal
cardiac arrest with a viable fetus, cesarean section should be initiated within 4 minutes of
cardiac arrest, with the goal of delivering the fetus within 5 minutes of onset of cardiac
arrest. This has been shown to allow neurologically intact survival of all infants
delivered.84Delivery after 5 minutes have elapsed results in increasing neurologic sequelae
in surviving infants but may still be beneficial to the majority of infants up until 15 minutes
after cardiac arrest. However, the goal should always be delivery of the neonate within 5
minutes of the loss of maternal cardiac function. Immediate abdominal delivery
accomplishes two goals in this setting: the removal of the fetus from what has become an
extremely hostile uterine environment and the increase of maternal blood return to the
heart by relieving uterine pressure on the maternal inferior vena cava. The perimortem
operation should be performed only when the fetus is suspected to be clinically viable. This
procedure should benefit both the mother and the fetus. As with any cardiac resuscitation
situation, the likelihood of good maternal and fetal outcome decreases with increased
interval to delivery time and increased time to the return of spontaneous circulation.85,86 It
is important to remember that the performance of a perimortem cesarean delivery outside
of an operating room under nonsterile conditions is not likely to negatively impact
maternal survival, because survival to discharge after a witnessed, in-hospital, cardiac
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