REBOA only for selected cases of placenta accreta spectrum

Placenta previa percreta with surrounding organ involvement: a proposal for management

Placenta accreta spectrum encompasses cases where the placenta is morbidly adherent to the myometrium. Placenta percreta, the most severe form of placenta accreta spectrum (grade 3E), occurs when the placenta invades through the myometrium and possibly into surrounding structures next to the uterine corpus. Maternal morbidity of placenta percreta is high, including severe maternal morbidity in 82.1% and mortality in 1.4% in the recent nationwide U.S. statistics. Although cesarean hysterectomy is commonly performed for patients with placenta accreta spectrum, conservative management is becoming more popular because of reduced morbidity in select cases. Treatment of grade 3E disease involving the urinary bladder, uterine cervix, or parametria is surgically complicated due to the location of the invasive placenta deep in the maternal pelvis. Cesarean hysterectomy in this setting has the potential for catastrophic hemorrhage and significant damage to surrounding organs. We propose a step-by-step schema to evaluate cases of grade 3E disease and determine whether immediate hysterectomy or conservative management, including planned delayed hysterectomy, is the most appropriate treatment option. The approach includes evaluation in the antenatal period with ultrasound and magnetic resonance imaging to determine suspicion for placenta previa percreta with surrounding organ involvement, planned cesarean delivery with a multidisciplinary team including experienced pelvic surgeons such as a gynecologic oncologist, intra-operative assessment including gross surgical field exposure and examination, cystoscopy, and consideration of careful intra-operative transvaginal ultrasound to determine the extent of placental invasion into surrounding organs. This evaluation helps decide the safety of primary cesarean hysterectomy. If safely resectable, additional considerations include intra-operative use of uterine artery embolization combined with tranexamic acid injection in cases at high risk for pelvic hemorrhage and ureteral stent placement. Availability of resuscitative endovascular balloon occlusion of the aorta is ideal. If safe resection is concerned, conservative management including planned delayed hysterectomy at around 4 weeks from cesarean delivery in stable patients is recommended.

The anesthetic approach to a patient with placenta accreta spectrum

PURPOSE OF REVIEW

Placenta accreta poses significant risk of morbidity and mortality to a laboring patient. Here we review available treatment options, highlight trends in bleeding prevention and diagnosis that have been shown to improve patient outcome, and provide best practice suggestions. We also discuss the decision-making process for choice of anesthesia, as it is not based on a gold-standard paradigm.

RECENT FINDINGS

The use of resuscitative endovascular balloon occlusion of the aorta has been gaining popularity around the world. It has been shown to cause an equivocal reduction in perioperative bleeding in placenta accreta spectrum (PAS), reduce the rate of hysterectomies, and is a safe and relatively easy technique. There are other invasive radiology techniques that have also proven to be beneficial in bleeding prevention: balloon occlusion of hypogastric arteries intraoperatively, internal iliac artery embolization, and intraoperative ligation of the hypogastric or uterine arteries.

SUMMARY

Optimal management of PAS begins with early and definitive diagnosis. A multidisciplinary approach along with preparation of special equipment and the use of a check-list maximize the chance for success. Anesthesia could be done with all types of regional or under general, considering case-by-case factors but most importantly choosing according to the institution's best facility and skill.