In this article we have described successful use of WCS placed in the lower uterine segment to achieve hemostasis in patients with placenta previa. To our knowledge, this is the largest case series using WCS in patients with placenta previa.
There are several challenges when performing cesarean sections in patients with placenta previa: the rapid accumulation of blood in the operation field obscures the bleeding site, and it is difficult to stop the bleeding. In an emergency situation, complex surgical procedures are not easy for inexperienced physicians. As a suitable adjunct for hemostasis, the compression sutures should fulfill three basic requirements. They should be simple, effective, and safe.
After the classic B-Lynch suture first reported in 1997,[3] a diversity of surgical sutures have been devised to treat postpartum hemorrhage, such as the square suturing technique, parallel vertical compression, and circular isthmic-cervical suture.[6, 7, 9] Thus far, no high-level evidence has demonstrated whether one suturing technique is more efficient and safer than another.[12] Cho et al.[6] reported a square suture hemostasis technique in 2000. It required four stitches to form a square; each square required to pass through the uterine wall at least eight times, and multiple squares were required. However, due to tight compression and insufficient blood supply, there is the possibility of uterine wall necrosis and uterine cavity synechiae.[12] Subsequently, Hwu et al.[9] modified this method and developed parallel vertical compression in 2005. The suture did not penetrate the entire\ posterior wall. Therefore, the hemostasis effect is uncertain and it could induce laceration of the posterior wall when the suture is tightened.[13] In 2008, Dedes and Ziogas[7] reported circular isthmic-cervical suturing to control hemorrhage from the lower segment during cesarean section in patients with placenta previa. However, there is an associated of uterine cavity occlusion because blood clots and debris entrapment are more likely to occur.[12]
Our study revealed that 91.1% of patients with thin anterior walls and uterine atony in the lower uterine segment could achieve hemostasis using WCS. No hysterectomy was required in any cases using WCS first-line. The results of our study demonstrate that this technique is effective in achieving hemostasis in patients with placenta previa with thin anterior walls and uterine atony in lower uterine segment and it has the potential to prevent hysterectomy.
Placenta previa is attached to the lower uterine segment, reaching or covering the inner cervix. The smooth muscle of lower uterine segment is relatively thin and the inner cervix is mainly composed of connective tissue with few muscle fibers. During the cesarean section in placenta previa, the lower uterine segment is unable to contract adequately and stop the flow of blood in the open vessels.[14] The anterior wall of the uterus is the weakest part of the lower uterine segment, particularly for patients with multiple cesarean sections. When the placenta is attached to the anterior wall of the uterus, the incidence of hemorrhage is higher than that when it is attached to the posterior wall.[15]
The WCS is mainly aimed at the thin anterior wall of the lower uterine segment. The principle is: first, the thin anterior walls of the lower uterine segment overlap each other to rapidly reduce the surface of the uterine wall from which the placenta detached. Second, this suture can occlude the uterine vessel beds and provide mechanical compression of the vascular sinuses of the anterior wall of the uterus to reduce blood flow to the lower uterine segment. Third, the WCS can restore the anatomical structure of the anterior wall of the uterus and contribute to postpartum uterine involution. In other words, the WCS has dual action in hemostatic compression of the bleeding surface and restoration of the anatomical structure.
In addition, our WCS has other advantages. First, the suture does not stitch the anterior and posterior walls together. It will not affect the morphology of uterine cavity. The lochia and necrotic debris can therefore be drained without the potential formation of pyometra. Second, it has no effect on the uterine blood supply, which promotes healing. Third, the thread traverses a short distance, possibly shorter than any other suture. This type of compression suture may provide greater direct tension to the compressed tissue. Fourth, WCS can be performed conveniently and quickly. Our WCS technique can be performed within a few minutes and does not require great expertise. This means the technique can be easily mastered and performed by junior surgeons in an emergency situation. Fifth, its punctures are done under direct vision, where there are no important structures such as great vessels or the ureter in the vicinity and do not injure adjacent organs.
Nevertheless, WCS has potential weakness because it is mainly aimed at the anterior wall of the lower uterine segment, it has limited ability to achieve hemostasis in other parts of the uterus, and therefore other hemostatic methods may be required. In our study, for hemorrhage from the inner cervix or uterine body, UAL, CHM or Bakri tamponade was required. Further the bladder must be pushed down to facilitate the procedure. If adhesions are present as a result of previous cesarean section, the operation is difficult and could cause injury to the bladder.
After surgery, there were no complications attributable to the WCS. All the women undergoing the WCS had normal postpartum lochia and normal menstruation following the cessation of breastfeeding. As a result of experiencing life-threatening delivery, women are often hesitant about future pregnancies, which may have made the reproductive analysis difficult. Of the five patients who had a second pregnancy, there were no intrauterine adhesions or uterine abnormalities caused by WCS. No ectopic or incision pregnancies occurred. Throughout the 5 years of observation and follow-up, we confirmed the safety of WCS.