Morbidly adherent placenta: A multidisciplinary approach

November 3, 2017|ObGyn

Conservative management

Interest in conservative management – in avoiding hysterectomy when it is deemed to carry much higher risks of hemorrhage or injury to adjacent tissue than leaving the placenta in situ – has resurged in Europe. However, research is still in its infancy regarding the benefits and safety of conservative management, and clear guidance about eligibility and contraindications is still needed (Am J Obstet Gynecol. 2015 Dec;213[6]:755-60).

In this case, a delayed hysterectomy was planned due to the degree of invasion. The neonate was delivered through a fundal classical incision and the placenta was left in-situ.

Still, multidisciplinary programs for complex obstetric surgery may enable careful selection of cases for conservative management, especially when there is good evidence that the placenta is growing into the bladder and the broad ligament. We took a conservative approach, leaving the placenta in situ, in 4 of the 26 patients who were delivered in our complex obstetric surgery program from its inception through June 2017. Of these four cases – all placenta percreta – two had been planned in advance as a two-step process with delayed hysterectomy, whereas we decided during surgery to leave the placenta in situ in the other two based on the degree of placental invasion.

One patient with the placenta left in situ had an urgent hysterectomy within 2 hours of delivery because of vaginal bleeding, with the total blood loss within an acceptable range and without complications. Another required an urgent hysterectomy 6 weeks after delivery because of severe hemorrhaging. The remaining two had nonurgent hysterectomies at least 6 weeks later, with the total blood loss minimized by the period of recovery and by some spontaneous regression of the placental bulk.

As we have gained more experience with conservative management and spent more time shaping multidisciplinary protocols, it has become clear to us that programs must have in place excellent protocols and strict rules for monitoring and follow-up given the risks of life-threatening hemorrhage and other significant complications when the placenta is left in situ.

A conservative approach also may be preferred by women who desire fertility preservation. Currently, in such cases, we have performed segmental or local resection with uterine repair. We do not yet have any data on subsequent pregnancies.

Research conducted within the growing sphere of complex obstetric surgery should help us to improve decision making and management of MAP. For instance, we need better imaging techniques to more accurately predict MAP and show us the degree of placental invasion. A study published several years ago that blinded sonographers from information about patients’ clinical history and risk factors found significant interobserver variability for the diagnosis of placenta accreta and sensitivity (53.5%) that was significantly lower than previously described (J Ultrasound Med. 2014 Dec;33[12]:2153-8).

Dr. Turan’s stepwise dissection

In addition to a multidisciplinary approach, a meticulous dissection technique can help drive improved outcomes. The morbidly adherent placenta is a hypervascular organ; it recruits a host of blood vessels, largely from the vaginal arteries, superior vesical arteries, and vaginal venous plexus.

Moreover, in most cases, this vascular remodeling exacerbates vascular patterns that are distorted to begin with as a result of the scarring process following previous uterine surgery. Scarred tissue is already hypervascular.

I have found that most of the blood loss during hysterectomy occurs during dissection of the poorly defined interface between the lower uterine segment and the bladder and not during dissection of the uterine artery. Identification of the cleavage plane and ligation of each individual vessel using a bipolar or small hand-held desiccation device are key in reducing blood loss. This can take a significant amount of time but is well worth it.

Managing super morbid obesity

The number of pregnant women who require challenging obstetric surgeries is increasing, and this includes women with super morbid obesity (BMI greater than 50 kg/m² or weight greater than 350 lb). Cesarean deliveries for these patients have proven to be much more complicated, involving special anesthesia needs, for instance.

Since women with super morbid obesity are at high risk of intrapartum and postpartum complications, these patients are also managed in our complex obstetric surgery program, with multidisciplinary prenatal assessment and surgical planning including anesthesia consultations. Thus far, these patients have had estimated blood loss that is similar to that of normal weight counterparts at our institution, and rates of complications that are lower than those described in the literature for gravidae with super morbid obesity.

In addition to women with placental implantation abnormalities (MAP and placenta previa, for instance) and those with extreme morbid obesity, the complex obstetric surgery program also aims to manage patients with increased risk for surgical morbidities based on previous surgery, patients whose fetuses require ex utero intrapartum treatment, and women who require abdominal cerclage.

Dr. Turan is director of fetal therapy and complex obstetric surgery at the University of Maryland, Baltimore, as well as an associate professor of obstetrics, gynecology, and reproductive sciences. He reported having no relevant financial disclosures.