Keywords
previa - devascularisation - hemorrhage - cesarean
The incidence of placenta previa ranges between 0.4 and 0.5% of all pregnancies.[1] Antenatal diagnosis of placenta previa is typically achieved via transvaginal ultrasound.
Ultrasonography generally allows for appropriate planning, with the goal to reduce
maternal morbidity and mortality. Placenta previa is defined as, when the placental
edge covers the internal cervical os.[2] In uncomplicated pregnancies, hemostasis in a cesarean delivery is achieved through
myometrial contraction, which leads to compression of spiral arteries. Women with
placenta previa are at an increased risk of peripartum hemorrhage, which is believed
to occur secondary to lack of contractile myometrium in the lower uterine segment,
resulting in ineffective compression of the spiral arteries and insensitivity to standard
administration of uterotonics. Management of uncomplicated placenta previa consists
of delivery by cesarean between 360 and 376 weeks.[3] In these cases, hemostasis is generally attempted with the administration of standard
medications, such as uterotonics, and with operative techniques, like balloon tamponade,
uterine packing, compression sutures, and uterine artery embolization.[4] Recently, hemostatic drugs, such as tranexamic acid and topical factor VII, have
been suggested as promising therapeutic agents for obstetric hemorrhage.[5]
[6]
In this manuscript, we describe a stepwise devascularizarion technique that we developed
and achieved hemostasis in the 3 cases of placenta previa with minimal maternal comorbidities.
Cases
In the 3 cases chronicled below, we describe a novel surgical approach that may be
applied to the cases of placenta previa ([Figs. 1]
[2]
[3]). In each case, we performed a stepwise approach of surgical devasculatization ([Table 1]) that consists of bilateral uterine artery ligation, both proximal and distal to
the uterine incision ([Fig. 1]). If this procedure failed to achieve hemostasis, we ligated individual arterial
bleeders in series with figure-of-eight sutures and then controlled the remaining
brisk bleeding in the placental bed with transmural horizontal mattress sutures ([Figs. 2] and [3]). The cases are summarized in [Table 2].
Table 1
Stepwise approach for achieving hemostasis in patients with placenta previa undergoing
cesarean delivery
|
Sequence of steps to progressive devascularization
Indication: continued dwelling of blood from the placental insertion site[a]
|
|
Step 1
|
Bilateral uterine artery ligation proximal / distal to the hysterotomy incision site
|
|
Step 2
|
Ligation of individual arterial bleeders using figure-of-eight technique
|
|
Step 3
|
Series of transmural horizontal mattress suturing over lower uterine segment below
hysterotomy incision site
|
a If hemostasis is achieved at any point between steps 1 and 3 in the sequence, the
sequence is terminated.
Table 2
Summary of cases
|
Skin incision
|
Operative findings
|
Fetal presentation
|
Bleeding description
|
Hemostasis technique
|
|
Case 1
|
Midline infraumbilical vertical
|
Low-transverse hysterotomy
|
Cephalic
|
Lower uterine segment bleeding
|
Bilateral uterine artery ligation proximal and distal to the hysterotomy, ligation
of arterial bleeders using the figure-of-eight sutures, and transmural horizontal
mattress sutures through the anterior surface of the cervix and the lower uterine
segment
|
|
Case 2
|
Midline infraumbilical vertical
|
Low-transverse hysterotomy
|
Footling breech
|
Uterine atony
|
Bilateral uterine artery ligation proximal and distal to the hysterotomy
|
|
Case 3
|
Low transverse
|
Low-transverse hysterotomy
|
Cephalic
|
Profuse bleeding from the anterior, inferior, and lower uterine segments bilaterally
|
Bilateral uterine artery ligation proximal and distal to the hysterotomy
|
Fig. 1 Bilateral uterine artery ligation proximal/distal to the hysterotomy incision site.
Fig. 2 Series of transmural horizontal mattress suturing over lower uterine segment below
hysterotomy incision site.
Fig. 3 Series of transmural horizontal mattress suturing over lower uterine segment below
hysterotomy incision site.
Case 1
A 29-year-old gravida (G) 5/para (P) 3/abortus (A) patient, with anterior complete
placenta previa at 36 weeks of gestation, underwent a scheduled cesarean delivery
under general anesthesia via a midline infraumbilical vertical skin incision through
the anterior abdominal wall. The hysterotomy was performed via a low-transverse incision
and extended laterally and cephalad via the Manu–Kerr technique. The amniotic cavity
was entered with a spontaneous rupture of membranes, and the fetus was noted to be
cephalic in presentation. The placenta was delivered through manual extraction. Closure
of the hysterotomy was complicated by lower uterine segment bleeding from the placental
bed, requiring bilateral uterine artery ligation proximal and distal to the hysterotomy,
ligation of arterial bleeders using figure-of-eight sutures, and transmural horizontal
mattress sutures through the anterior surface of the cervix and the lower uterine
segment to achieve hemostasis. Preoperatively, the patient's hemoglobin level was
12.9 g/dL, and postoperatively her hemoglobin level was 6.9 g/dL. Intraoperative blood
loss was estimated to be 2,000 mL.
The patient did not require any blood product transfusions during her hospital stay
and was discharged on postoperative day (POD) #2, after receiving standard postpartum
care with no complications.
Case 2
A 32-year-old G4/P2/A1 patient, at 34 weeks of gestation with anterior complete placenta
previa, underwent a cesarean delivery under general anesthesia via an infraumbilical
vertical skin incision through the anterior abdominal wall. The hysterotomy was performed
via a low-transverse incision. The amniotic cavity was entered, and the fetus was
noted to be in footling breech. The placenta was delivered through manual extraction.
Upon closure of the hysterotomy, brisk bleeding was noted, and a decision was made
to perform a bilateral uterine artery ligation, proximal and distal, to the hysterotomy.
Hemostasis was achieved and it was decided to proceed with further devascularization.
Concomitant administration of uterotonics (methylergonovine and prostaglandin F2α)
was administered as well. Intraoperative blood loss was estimated to be 2,000 mL.
The patient's preoperative hemoglobin level was 12.1 g/dL, and postoperatively her
hemoglobin level was 8.9 g/dL.
The patient developed symptomatic anemia and opted to receive 1 unit of packed red
blood cells postoperatively. The patient was discharged on POD #3 after receiving
standard postpartum care with no complications.
Case 3
A 40-year-old G5/P4/A0 patient, at 36 weeks of gestation with anterior complete placenta
previa, underwent a cesarean delivery under general anesthesia via a low-transverse
skin incision through the anterior abdominal wall. The low-transverse incision was
extended laterally and cephalad via the Manu–Kerr technique. The amniotic cavity was
entered bluntly with an Allis clamp, and the fetus was noted to be cephalic. The placenta
was delivered through manual extraction. Upon closure of the hysterotomy, profuse
bleeding from the anterior, inferior, and lower uterine segments was noted, and a
decision was made to perform a bilateral uterine artery ligation, proximal and distal,
to the hysterotomy. Hemostasis was achieved and no further devascularization procedures
were required. Intraoperative blood loss was estimated to be 2,000 mL. The patient's
preoperative hemoglobin level was 12.1 g/dL, and postoperatively her hemoglobin level
was 7.7 g/dL.
Postoperatively, the patient developed symptomatic anemia and opted to receive 2 units
of packed red blood cells. The patient was discharged on POD #3, after receiving standard
postpartum care with no complications.
On POD #15, the patient presented to the emergency department with yellow-mucoid wound
discharge consistent with wound infection. The patient was prescribed a 7-day course
of antibiotics and instructed to follow up as an outpatient in 3 weeks.
Discussion
Placenta previa affects up to 5 out of every 1,000 pregnancies.[7] It may be a major source of intrapartum morbidity and is often associated with profuse
hemorrhage, intensive care unit admission, and peripartum hysterectomy.[8]
[9] Nowadays, the diagnosis of placenta previa is mainly based on the transvaginal ultrasonography.[2] Ultrasound findings suggestive of placenta previa include placental edge above the
cervical os; if the edge is within 2 cm of the cervical os, the term “low lying placenta”
is used instead.
Antenatal diagnosis of placenta previa typically allows for adequate preoperative
arrangements to be made, as an effort to reduce maternal morbidity. Patients should
be counseled regarding potential complications, including third-trimester bleeding,
need for cesarean delivery, intrapartum hemorrhage, abnormal placentation (3% and
above), and the risk for peripartum hysterectomy. Patients with a history of prior
cesarean deliveries should be informed that the increasing number of cesarean deliveries
is associated with an increased risk of maternal comorbidities and complications[10]
The opinions expressed in the literature regarding other procedures using uterine
compressive sutures, balloon tamponade, and uterine packing are highly variable.[11] The available evidence comes mainly from case reports and case series.[11] In some cases, selective arterial embolization has been reported. There are limited
data as, which uterine conservative modality is superior.[12] Moreover, most of these cases involved severe cases of placenta accreta spectrum
(PAS) disorders (percreta) and were later complicated by delayed hysterectomy, septic
shock, and hemorrhage.[13]
[14]
[15]
[16]
Since in all three cases described, placenta removal was not easy (manual extraction
was performed) and histological diagnosis for PAS disorders could not be obtained
for obvious reasons, placenta creta could not be confirmed. Hence, it is important
to mention that the present described technique can be useful in such cases, especially
when it is “focal”.
Our surgical approach seemed to carry little additional morbidity as compared with
traditional management of placenta removal, tamponade, or other conservative strategies.
We have used this approach in 3 patients and achieved hemostasis in each. For patients
with placenta previa and a low risk for placenta creta, counseling should include
the risk for maternal morbidity and criteria for pursuing a peripartum hysterectomy;
it should also include our surgical approach. For clinicians who struggle to achieve
hemostasis in these types of cases, we recommend consideration of our devascularization
approach.
