The usual surgical sequence during cesarean section for placenta previa start with delivery of the baby through the placenta. Then if the placenta was adherent the surgeon may decide to do hysterectomy, at this point the blood loss will be significant, due to incising the placenta and the time taken in dissecting the bladder (9, 12, 13, 14).
In this paper we compare the outcome of two approaches for cesarean delivery in cases of placenta previa (transecting or avoiding incising the placenta) regarding the amount of blood loss, packed RBCs needed, ICU admission and the length of hospital stay. It has shown that avoid transecting the placenta decreases the blood loss, the need for blood transfusion, ICU admission and the length of hospital stay.
In this paper primigravida were excluded because we do not do classical cesarean section on unscarred uterus as we believe that usually the placenta will separate easily although there is still a risk for massive hemorrhage when transecting the placenta. Patients with posterior placenta previa were excluded as well because the concept of our approach is to avoid incising the placenta so opening the lower segment is feasible in these cases.
There are few studies relate the amount of blood loss during operation with delivering through the placenta. One study showed that anterior placenta previa is at high risk of massive blood loss during operation (17). A retrospective study compared between transecting or avoiding the placenta during surgery, with larger sample size and they concluded that avoidance of placenta will decrease blood loss and the need for blood transfusion (18).
The described surgical approach in our article focuses on two concepts. The first concept is to dissect the bladder and free the adhesions around the lower uterine segment assuming that the patient may have placenta accreta and she may need hysterectomy. The second concept is to avoid the placenta by doing high vertical incision at the fundus to decrease the blood loss. Same concept applied by Pradip Kumar Saha et al (2) on 12 cases suspected to have placenta accrete which resulted in less hemorrhage and no reported case of bladder or ureteric injury.
In reviewing guidance for surgical approach in placenta previa, no committee gives a clear guidance on how to perform the surgery. The RCOG recommends avoiding the placenta and using intraoperative ultrasound to localize the placenta (19). In this described surgical technique, we keen on opening the abdominal wall by midline incision because it will give better access to the upper segment, so the uterine incision can be done away from the placenta. Moreover, the midline incision will give better access to the broad ligament so surgeon can start dissecting the bladder laterally where there are no adhesions.
We recommend opening the upper uterine segment vertically for two main reasons. First the transverse incision may extend to the broad ligament, second the uterine smooth muscles are arranged in a vertical pattern (20) thus, in a high vertical incision we transect less muscle fiber and make it easy to repair. Eric Verspyck et al compared between two surgical method one of them aims to avoid the placenta by circumventing it and avoiding the placenta was possible in 67% of the cases (16). In our 12 cases, avoiding the placenta was possible even if the placenta extended to the anterior wall but the surgeon may need to open the fundus in some case (Fig. 2) and (Fig. 3). Some may rise the concern about the next pregnancy, but increasing the expected risk of rupture uterus and adhesions in the next pregnancy is worth the value of significant decrease in maternal mortality and morbidity keeping in mind that we do not apply this approach on unsacred uterus or placenta previa posterior.
As any retrospective study the frequency of each outcome was not aimed to be calculated. Hence, the results of our study can be applied in well-designed prospective trial. Moreover, our study has some limitation and potential bias. First, the two approaches were done by different surgeon thus the surgical experience may influence the outcome. Second, there are no clear policy to calculate blood loss in our hospital and it depends completely on surgeon’s estimation but still, the number of packed RBCs given hints the amount of blood loss during operation.
Finally, restoring the anatomy before incising the uterus and avoid transecting the placenta may decrease blood loss. But still, well designed study is needed to confirm.