A 40-year-old woman, gravida 0, was admitted to Seoul National University Bundang Hospital in August 2011 for elective Cesarean section and prophylactic intraoperative UAE at 36 weeks and 6 days gestational age. Two thirds of the placenta was located in the posterior wall of the uterus and the remaining placenta was located in the anterior lower segment of the uterus resulting in complete covering of the internal os of cervix. Under spinal anesthesia, a low transverse uterine incision was made and after gently penetrating part of the placenta directly behind the incision site, a live 2,815 g baby was delivered. The upper and lower cut edges and each lateral angle of the uterine incision were clamped using Allis forceps. The torn placental margin was also clamped using Allis forceps. An interventional radiologist, who had been already stood by, stepped into the operation field and then inserted an angiographic catheter into the right femoral artery and approached both uterine arteries using portable fluoroscopy. Insertion of the catheter took five minutes. During that time, the surgeon had observed the uterus carefully for detection of bleeding. Embolization was performed with gelfoam under fluoroscopic guidance for bilateral enlarged tortuous uterine arteries and it took 20 minutes (Fig. 1). After confirming via angiography that there was markedly decreased blood flow, the surgeon removed the placenta. However, bleeding from the implantation site was profuse even though both uterine arteries had been embolized. Bleeding was ultimately controlled by over-sewing the implantation site with 0-monofilament absorbable suture and the rest of the surgery was uneventful. Estimated blood loss for this surgery was 2,500 mL. The patient received five units of packed red blood cells and three units of fresh frozen plasma during the operation. The next day, the patient's hemoglobin was 10.1 g/dL and the sheaths were removed. Routine postoperative care was performed and the patient was discharged from the hospital four days after surgery with no complications.

A 32-year-old woman, gravida 2, para 0, was admitted to Seoul National University Bundang Hospital at 35 weeks and 5 days gestational age with symptoms of vaginal bleeding in October 2011. Trans-vaginal ultrasonography revealed that the placenta completely covered the internal os. Approximately two thirds of the placenta was located in the posterior wall of the uterus and the remaining portion was located in the anterior lower segment of uterus. When the patient and her husband were counseled about the risk of hysterectomy, they strongly requested preservation of the uterus for future fertility. Therefore, a Cesarean section with prophylactic intraoperative UAE was planned. Under spinal anesthesia, a uterine incision was made transversely at the lower uterine segment. The surgeon could not avoid tearing the placenta before the female newborn weighing 2,465 g was delivered. The torn placental margins and the cut edges of the uterus were clamped by Allis forceps. During the interventional radiologist tried to insert an angiographic catheter into the right femoral artery for four minutes, the surgeon found a diffuse hemorrhage from the torn placental margin and cut edges of the uterus. At this point, the surgeon abandoned the plan of a prophylactic UAE. The surgeon removed the placenta manually and profuse hemorrhage from the placental bed sites developed. Although the implantation site was repeatedly over-sewn with 0-monofilament absorbable suture, bleeding was quite severe, thus a Cesarean hysterectomy was indicated. However, it was decided that intraoperative UAE would be attempted once more before the Cesarean hysterectomy since massive transfusion was successful. The interventional radiologist inserted an angiographic catheter into the right femoral artery and approached both uterine arteries. Embolization with gelfoam was performed under fluoroscopic guidance for bilateral enlarged tortuous uterine arteries (Fig. 2A). Fortunately, blood flow decreased on angiography and bleeding through the vagina decreased. At this point it seemed possible to avoid a hysterectomy. The uterine wall was repaired after an additional intraoperative UAE. Estimated blood loss was 5,000 mL and massive transfusion (9 packs of RBC and 3 packs of FFP) was performed during the operation. Although bleeding decreased markedly after two attempts of intraoperative UAE, the patient was transferred to the angiography room for another attempt at UAE. Embolization of the uterine artery was performed with a coil in the angiography room (Fig. 2B) and then the patient was transferred to the intensive care unit (ICU) for close observation. While in the ICU, the patient received three more packs of RBC and six more packs of FFP as well as cryoprecipitate and platelet. The next day, her hemoglobin level was 10.2 g/dL and vital signs were stable. She was transferred to the general ward for further postoperative care. On the second day after surgery, the patient presented with a fever of 39.1℃ and after a full fever study, her antibiotic regimen was changed. The fever resolved on the fourth day and the patient was discharged from the hospital 10 days after surgery with no other complications.