2021 年 9 巻 3 号 p. 60-63
The transverse fundal uterine incision (TFUI), a new cesarean section technique, is effective in cases of abnormal placentation which may cause massive hemorrhage. A 43-year-old multipara woman underwent TFUI cesarean section after being diagnosed with placenta previa. One year and 4 months later, she conceived naturally. The placenta was located on the previous cesarean section scar, and placenta percreta was suspected on magnetic resonance imaging. At 35 weeks and 2 days of gestation, cesarean delivery was performed. After a decision was made not to remove the placenta, total hysterectomy was performed, and bleeding was successfully controlled. Histopathological analysis of the uterus revealed placenta accreta. Although TFUI is a useful cesarean section method, the risk of placenta accreta may increase in the next pregnancy, requiring careful perinatal management.
Transverse fundal uterine incision (TFUI) cesarean section can reduce the need for hysterectomy in cases of placenta accreta and placenta previa covering the entire anterior wall of the uterus.1) This technique reduces bleeding by avoiding transection of the placenta and enables removal of the placenta under direct observation. Since it is a relatively new technique, its effect on subsequent pregnancy is unknown. We report a case of placenta accreta in a pregnancy after TFUI cesarean section.
The patient was a 43-year-old woman, gravida 3, para 2, with an unremarkable medical and family history. She delivered her first baby spontaneously. During the second pregnancy, she was diagnosed with placenta accreta and underwent TFUI cesarean section with intraaortic balloon occlusion. During the operation, the placenta, which was widely attached to the anterior uterine wall from the internal os, spontaneously detached with partial rest. The uterus was conserved with minimal bleeding, and the uterine incision was closed with interrupted sutures in three-layers. No complications were observed during the postoperative period. Five months later, transvaginal ultrasound showed thinning of the uterine muscle at the fundal scar site (Figure 1A).
Trans-vaginal ultrasound.
(A) Five months after previous cesarean section. The scar in the uterine fundus is thin. (B) At 13 weeks of gestation, the placenta covers the scar, and the bottom of the fundus appears to be collapsing; point as allow.
One year and 4 months later, she was diagnosed with intrauterine pregnancy and referred to our hospital. She was informed of the risk of uterine rupture and placenta accreta due to prior TFUI. At 13 weeks of gestation, transvaginal ultrasound revealed the uterine fundus with a rough surface and the placenta covering the fundal scar (Figure 1B). The patient and her family decided to continue with the pregnancy after being explained the high risk of uterine rupture and placenta accreta. At 23 weeks of gestation, transabdominal ultrasound revealed the presence of lacunae in the placenta, which were filled by 33 weeks of gestation (Figure 2A, 2B). At 33 weeks of gestation, magnetic resonance imaging revealed a flow void in the anterior uterine body (Figure 3A, 3B) which continued to the abdominal wall, suggesting placenta percreta through the abdominal wall. She visited our outpatient clinic regularly until 34 weeks of gestation and was then admitted for close observation.
Trans-abdominal ultrasound.
(A) At 23 weeks of gestation, lacunae in the placenta were observed, and blood flow was confirmed in the Doppler mode. (B) At 33 weeks of gestation, lacunae in the placenta grew in size. Placenta accreta was strongly suspected.
T2-weighted magnetic resonance imaging at 33 weeks of pregnancy.
(A) Transverse section. (B) Sagittal section. White arrow indicates the flow void, suggesting placenta percreta.
At 35 weeks and 2 days of gestation, she had a cesarean section. Before surgery, 800 ml of autologous blood was prepared. A vertical abdominal skin incision was made from the symphysis pubis to below the umbilicus. A low anterior transverse uterine incision was made, and a healthy female infant weighing 1,902 g with an Apgar score of 9/10 was successfully delivered. Many blood vessels were exposed on the surface of the anterior uterine wall. The surface of the uterus was even and smooth. The greater omentum coalesced with the anterior uterine body, with no adhesion of the abdominal wall to other organs. The placenta did not detach spontaneously and was left in the uterus. The myometrium of the uterus was closed with continuous sutures. To control bleeding, total hysterectomy was performed immediately. Estimated blood loss was 3,453 ml, and operative time was 2 hours and 17 minutes. The stored autologous blood (800 ml) was transfused, and no allogeneic blood transfusion was required. Histopathological analysis revealed a thin uterine muscular layer in direct contact with the villi, not through the deciduous membrane. The pathological diagnosis was placenta accreta. She had an ileus on postoperative day 4 and fasted for a day. No other complications were noted, and she was discharged on postoperative day 8. The neonate received routine care as a preterm, low-birth-weight infant. On post-delivery day 21, the infant was discharged from the hospital.
TFUI cesarean section was first proposed by Kotsuji et al. in 2004.2) To avoid transecting the placenta, the incision line is preferably determined by intraoperative ultrasound. Cutting through the muscle layer at the uterine fundus reduces blood loss and makes possible the removal of the placenta under direct observation.
The incidence of uterine rupture and placenta accreta increases after cesarean section with an unusual uterine incision. Sumigama et al. reported that 37% of pregnancies with placenta previa were related to former cesarean delivery. The adjusted odds ratio for prior classical (i.e., high vertical) cesarean section relative to low transverse cesarean was 3.23 (95% confidence interval: 1.11-9.39) for uterine rupture and 2.09 (95% confidence interval: 0.69-6.33) for placenta accreta.3) The safety of subsequent pregnancy and occurrence of placenta accreta after TFUI cesarean section have not been investigated in detail. Moreover, while cases of pregnancy after TFUI cesarean section have been reported in Japan,4) no case of placenta accreta following TFUI cesarean section has been reported.
The appropriate timing of admission and delivery after TFUI cesarean section is difficult to determine. Kotsuji et al. recommended an earlier admission at 24 to 25 weeks of gestation and delivery at 33 to 34 weeks of gestation, when fetal pulmonary maturation is expected to have taken place.5) Our patient was followed regularly as an outpatient until 34 weeks of gestation, and cesarean delivery was performed at 35 weeks of gestation, with favorable outcomes for both the mother and baby. The placenta, which covered the thin fundal uterine muscle layer, may have helped prevent uterine rupture.
In conclusion, TFUI cesarean section is a safe procedure for placenta previa, but may be a risk factor for placenta accreta in the next pregnancy. Strategic therapy could lead to favorable maternal and fetal outcomes. The accumulation of more cases will be needed to assess the risks and safety of pregnancy after TFUI cesarean section.
This case report received no financial support.
None to report.
