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Radiology
Prophylactic rerioperative bilateral internal iliac artery balloon occlusion in placenta percreta
Case 33: Contributed by Dr. Bhavesh Popat
A 31-year-old woman presented for her obstetric US examination at 28 gestational weeks with a history of intermittent vaginal bleeding. Her past obstetric history included two cesarean deliveries (one with a classic incision and the other with a low transverse incision). Abdominal ultrasound was performed and demonstrated a normal-appearing 26-week fetus with an anterior, low-lying placenta that was a complete placenta previa. There was a loss of the retro placental hypoechoic zone with interruption of the hyperechoic border between the uterine serosa and bladder (Fig 1).
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Fig. 1 |
Fig. 2 |
A color Doppler examination showed prominent vessels or lakes within the placenta and myometrium (Fig 2).
The presumptive sonographic diagnosis of placenta previa with percreta was made. The possibility of bladder wall invasion was suggested; however, the patient did not have a documented history of hematuria. She continued to bleed intermittently throughout the remainder of her pregnancy, and the US findings persisted on follow-up obstetric sonograms.
At 34 gestational weeks, the patient continued to have low-level vaginal bleeding, and the decision to perform a Cesarean section was made. The patient was thought to be at extreme risk for intraoperative bleeding because of the presence of placenta previa with percreta and possible bladder wall invasion and the possible complication of adhesions from her prior multiple surgeries. The obstetricians did not believe that they could deliver the fetus without putting the patient and fetus at risk. Therefore, the vascular interventional radiology service was consulted for the prophylactic placement of balloon catheters in both internal iliac arteries.
6 Fr access via both the common femoral arteries was secured. Taking into account the radiation exposure to the fetus, we placed balloon catheters (Arrow International, Germany ) within the anterior divisions of both the internal iliac arteries under strict collimation. (Fig 3)
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Fig. 3 |
With these uninflated occlusion balloon catheters in place, the balloons could be inflated to occlude blood flow to the uterus in the event of severe hemorrhage. The infant was delivered atraumatically through a high transverse fundal (classic) incision, which avoided the placenta. The obstetrician found that the lower anterior uterine segment was adherent to the bladder wall. At this point, the patient began to bleed slowly. We inflated the balloon catheters to decrease the degree of blood loss while the obstetricians placed the placenta back into the uterus and closed the incision. However since the patient’s systolic blood pressure had fallen to 90 mm Hg even after 45 minutes of inflation, plan for embolization of anterior division of internal iliac arteries was made and the patient was shifted back to DSA lab (Fig 4).
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Fig. 4 |
Selective angiograms of anterior divisions of both internal iliac arteries demonstrated dilated tortuous uterine arteries supplying the placental tissue. (Fig 5 & 6)
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| Fig. 5 | Fig. 6 | ||
Both the anterior divisions were embolised using platinum coils. The post embolization angiogram revealed complete occlusion of the anterior divisions (Fig 7 & 8).
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| Fig. 7 | Fig. 8 | ||
She was given methotrexate injections after 48 hrs once adequate collaterals would have had developed .She recovered uneventfully and was discharged 10 days after surgery.
DISCUSSION:
In a normal pregnancy, the placenta is formed at the implantation site by a combination of the chorion frondosum from the developing embryo and the decidua basalis. When the decidua is partially or completely absent, abnormal placental implantation may occur.
Depending on the location of the implantation, the condition is referred to as placenta accreta, placenta increta, or placenta percreta. (Fig 9)
- Placenta accreta : If the placental villi extend beyond the confines of the endometrium and attach to the superficial aspect of the myometrium, the term placenta accreta is used.
- Placenta increta : refers to a situation in which the villi invade the myometrium, whereas
- Placenta percreta : is used if the villi advance into the serosa or parametria
Placenta accreta is the most common form of placental invasion (76% of cases), followed by placenta increta (17%) and placenta percreta (5%).
The primary risk factors are placenta previa, advanced maternal age, and prior cesarean section.
Postpartum hemorrhage is a serious complication of placenta accreta, percreta, and increta that can cause considerable morbidity and can potentially be fatal. Most cases of maternal morbidity and mortality are caused by uncontrollable hemorrhage or hemorrhage complicated by sepsis. Antenatal recognition of placenta accreta and careful planning by the obstetrician can decrease blood loss during delivery and reduce the risk of serious maternal complications.
Traditionally, the treatment of placenta accreta has been a cesarean hysterectomy. More conservative treatment with dilation and curettage with embolization is also an option. Bleeding may also be controlled by surgical ligation of uterine or internal iliac arteries, but this technique is less effective for placenta accreta and more effective in minimizing hemorrhage for uterine atony and midline perforation. In a review of the obstetrics literature, surgical ligation of the internal iliac artery as a means to control hemorrhage led to a failure rate of 57% because of significant pelvic collateral vessels. In addition, pelvic dissection with clamping of the internal iliac arteries was believed to be too difficult and time-consuming. If the patient were acutely hemorrhaging, the time consumed in defining the anatomy of the internal iliac arteries could be life threatening.
Although optimal indications for prophy lactic catheter placement have yet to be established, we recommend placing balloon catheters within the anterior division of the internal iliac arteries for patients with placenta accreta and placenta percreta. Occlusion of the internal iliac arteries does not halt blood flow to the uterus because there is a rich supply of collaterals. However, the technique does reduce pulse pressure distal to the site of occlusion, thus minimizing blood loss during hysterectomy.
Bilateral insufflation of the catheters allows hemodynamic stability and optimal exposure of pelvic organs during surgery. The potential need for blood products is therefore reduced. The technical aspects of the procedure are straightforward with minimal procedure-associated risks. In addition, it is performed quickly with minimal fetal radiation exposure. Coil embolization should be taken in selective cases and can be planned if clinically indicated. The success rate in patients with normal clotting system is 90%.
In conclusion, abnormal placentation such as placenta accreta or percreta is a potentially life-threatening hemorrhagic condition. The use of prophylactic occlusive arterial catheters during cesarean hysterectomy is effective option in management for hemostsis.