DOI: https://doi.org/10.21203/rs.3.rs-1774584/v1
Background: Uterine compression sutures have been reported to be an effective intraoperative hemostatic method in placenta previa or accreta. Nonetheless, this suture narrows the cavity of the lower uterine segment, making additional hemostatic measures difficult. Furthermore, extensive blockage of blood perfusion, in both the anterior and posterior walls, increases the risk of ischemia.
Patients and Methods: We developed a V-shaped uterine suture (VUS), in which the suture was applied only on the side of placental detachment, including the area of the internal uterine ostium. Of the 20 cases of partial and total placenta previa diagnosed by transvaginal ultrasonography, between January 2018 and December 2021, VUS was performed in 14 cases using the following criteria: 1) gushing bleeding from the vicinity of the internal uterine ostium; 2) once the bleeding was removed, the time taken to re-fill the uterine cavity below the uterine incision, was 5 s or less.
Results: The mean intraoperative blood loss was 1212±463 ml (range: 700-2100 ml). All procedures were completed in < 5 min, without the need for blood transfusion. Ultrasonography showed no uterine abnormalities on the fourth postoperative day or during the one-month follow-up evaluation.
Conclusion: VUS is a simple and quick suturing technique to control massive hemorrhage in placenta previa or accreta with no narrowing of the lower part of the uterus and minimal blockage of the uterus.
We suggest that VUS should be performed first, to obtain reliable hemostasis and prevent critical hemorrhagic damage.
Various hemostatic methods have been reported for bleeding from the uterine body during Cesarean section [1, 2]. For placenta previa or accreta, interventional radiology technique, such as intra-arterial balloon occlusion and intraoperative uterine artery embolization, have been used to reduce intraoperative bleeding in placenta previa and placenta accreta [3, 4]. Nonetheless, the intra-arterial balloon occlusion only temporarily obstructs blood flow to the uterus and does not maintain hemostasis, whereas the intraoperative uterine artery embolization takes longer to achieve hemostasis. Both interventions require X-ray exposure and elaborate preoperative preparation.
In contrast, compression sutures on the lower segment of the uterus have been reported for intraoperative hemostasis in placenta previa or accrete [5–7].
The problem with compression sutures is that they compress both the anterior and posterior walls of the lower uterus, and narrows the cavity of the lower uterine segment, making additional hemostatic measures difficult, when bleeding persists. Furthermore, extensive blockage of blood perfusion in both the anterior and posterior walls increases the risk of ischemia. Therefore, further innovations in hemostatic suturing are required for placenta previa and accreta. Ideally localized sutures should be applied directly to the bleeding area adjacent to the internal uterine ostium.
We developed a new hemostatic suture method for V-shaped uterine sutures (VUS) and reported its technique and efficacy.
This was a retrospective observational study, conducted at Uji-Tokushukai Medical center in Kyoto, Japan.
In cases of placenta previa that underwent cesarean section at the
department, between January 2018 and December 2021, partial and total placenta previa diagnosed by transvaginal ultrasonography were included, excluding marginal placenta previa. Total placenta previa was defined as coverage 2cm or more of the internal uterine ostium by the placenta. Partial placenta previa was defined as coverage less than 2 cm of the internal uterine ostium by the placenta.
Cesarean sections in case of placenta previa do not always result in excessive bleeding, and no special hemostatic maneuvers are required. To exclude overtreatment with VUS, the following criteria was used to defined excessive bleeding for which VUS was indicated in the present study.
1, Blood gushing from the vicinity of the internal uterine ostium
2, If the time taken to re-fill the lower uterine cavity was 5 s or less after the accumulated blood was removed.
The “V-shaped uterine suture (VUS)” technique：
1. The steps before fetal delivery were performed in the same way as a typical cesarean section, under combined spinal epidural anesthesia and in the lithotomy position.
2. After the fetus was delivered, we waited for spontaneous detachment of the placenta. Soon after placental detachment, the uterus was exteriorized and bimanual compression was applied to the lower segment, with direct inspection of the bleeding site.
3. If active bleeding remained and met the inclusion criteria, VUS was immediately performed.
4. In VUS, the suture needle and thread used were dedicated 80-mm double-ended straight blunt needles, developed by Alfresa Pharma Corporation and Osaka University for use with a 90-cm No. 2 polydioxanone suture (2-Monodiox®), which was designed for uterine compression sutures [8].
5. In cases of placenta previa with posterior wall attachment, one end of the Monodiox needle thread was transfixed straight backwards into the posterior wall, at the level of the inner uterine ostium, to penetrate the full layer (Step 1). The tip of the needle should be guided by the surgeon's finger, so that it emerges at the midline of the posterior wall of the cervix, taking care to avoid the rectum.
6. Next, the needle on the other side of the thread (second needle) was transfixed approximately 4-5 cm above the left side of the first needle, to penetrate the entire layer of the posterior wall (Step 2). The knots were inserted as tightly as possible, to control active bleeding (Step 3).
7. After suturing was completed on the left side, the suturing methodology was repeated on the right side of the lower uterus (Step 4). The VUS at the lower apex, at the level of the internal ostium, was placed in the posterior wall of the lower uterus (Figures 1 and 2).
8. The area of the suture can be expanded according to the size of the bleeding area, by adjusting the transfixion level of the second needle.
The effectiveness of VUS was assessed by the following items.
1. Comparison of re-filling times before and after VUS.
2. Estimated intraoperative blood loss.
3. Additional hemostatic measures.
We performed this suture within the normal scope of practice and started this study with prior safety assurance. On admission, written informed consent for publication on an anonymous basis was obtained from the all patient participating in this study.
This technique was approved by the Ethics Committee of Tokushukai Medical Center. This study has been performed in accordance with the Declaration of Helsinki.
Of the 20 sequential cases of partial or total placenta previa, 14 met the criteria for VUS (twin pregnancy, n=2; placenta accreta, n=2; Table 1). In all 14 cases, the main site of placental attachment was the posterior uterine wall.
Blood re-filling times of the lower uterine cavity were 4.3 s of the mean value in the pre-VUS, and 15 s and more in the post -VUS, respectively.
The VUSs were completed within 5 min, and the operation times were almost the same as usual in all cases. Images of stitches and knots in the posterior wall are shown in Figure 3. The condition of the lower part of the uterus before and after VUS is shown in Figure 4.
The mean estimated amount of intraoperative blood loss was 1212±463 ml, (range, 700-2100 ml). All procedures were completed without the need for a blood transfusion (Table 1).
Four patients had intraoperative bleeding of >1500 ml (two twin pregnancies and two partial placenta accreta). Among them, two cases were complicated by a bleeding volume > 2000 ml (cases 7 and 10). Additional measures were performed in these cases, including Bakri-balloon tamponade, in the case of atonic bleeding with twin pregnancy (case 7), and gauze packing, in the case of placenta accreta (case 10), in which persistent bleeding was easily stopped.
In singleton pregnancies with placenta previa, the bleeding was <1500 ml in all 12 cases with quick hemostasis after the knots were tied, and no additional requirement of hemostatic measures or blood transfusion was required.
On the fourth postoperative day, ultrasound examination was performed in all cases and showed no abnormal findings, including unusual uterine blood pooling or arteriovenous malformation. One month after the delivery, ultrasonography revealed no uterine abnormalities. All 14 women resumed normal menstruation. In case 2, 2 years later, the woman had a spontaneous pregnancy, and a full-term baby was delivered via cesarean section.
For bleeding with uterine atony in postpartum or cesarean section, various methods of hemostatic suture and balloon tamponade in the uterine body have been reported, including the B-lynch suture and Bakri-balloon [1, 2].
In placenta previa and accreta, heavy hemorrhaging is often encountered with gushing from the lower part of the uterus. This hemorrhaging is difficult to stop, and effective hemostatic methods are limited, especially for bleeding from the area around the internal uterine ostium. In such cases, conventional methods such as direct suturing, gauze filling, and uterine balloon tamponade were used, as in the case of uterine atony [9,10].
Meanwhile, compression sutures, in which the lower anterior and posterior uterine walls are compressed to stop bleeding, have also been reported [5,6]. A typical method of compression suturing on the lower segment of the uterus is the parallel vertical compression suture (PVCS), devised by Hwu et al. [5]. This suture penetrated the anterior wall of the lower uterus, but not the posterior wall, only through the muscle layer. On the other hand, Tanaka et al. [6] reported a full-thickness suture penetrating the anterior-posterior wall of the uterus. This allows the lower part of the uterus to be easily compressed to stop the bleeding. Furthermore, Li et al. [7] reported a method of revising the suturing position spanning over the uterine incision.
These compression sutures on the lower segment of the uterus are easy and quick to perform; however, some problems remain. First, compression sutures reduce the cavity of the lower uterus; therefore, if required, additional hemostatic measures are difficult to perform. In particular, gauze packing or Bakri-balloon tamponade can be difficult and inadequate, owing to narrowing of the cervix. Second, compression sutures involve extensive blockages of both the anterior and posterior walls of the lower uterus, which may have an adverse impact on subsequent pregnancy.
Finally, when the suture is placed too laterally to the uterus, it may damage the uterine artery, whereas when it is placed too close to the median, it may obstruct the cervical canal, resulting in poor evacuation of the lochia.
Considering the abovementioned details, we developed VUS as a simple and quick method to achieve hemostasis in placenta previa during laparotomy, which overcomes the disadvantages of PVCS. VUS is designed to be effective for hemostasis, even when the bleeding site involves the internal ostium, because direct sutures can be applied on the involved site.
We used a straight blunt needle to penetrate the uterine wall, developed by Matsuzaki et al.[8], which enabled minimal invasion of the fragile surface of placental detachment, due to the blunt needle, and easy control of the needle tip during penetration, due to the straight needle. Nonetheless, when performing VUS in clinical practice, it is not necessary to use this special, long needle. Unlike compression sutures which require a long needle in the case of VUS, the conventional needle is sufficient in size because only one side of the uterine wall is penetrated. This is an important clinical advantage of VUS.
Thus, VUS is characterized by suturing only one side of the lower uterine wall surrounding the bleeding site of the placental detachment. This is the first report of localized hemostatic suturing on the side of placental abruption that is sufficient for hemostasis in placenta previa and accreta.
The most commonly used parameter to assess the hemostatic efficacy of intraoperative procedures is estimated intraoperative blood loss. The mean estimated intraoperative blood loss in our 14 patients with VUS was 1212 ± 463 ml (range, 700-2100 ml). Furthermore, in the 12 singleton cases, the mean blood loss was even lower (1130 ± 429 ml). In five cases of total placenta previa, blood loss was <1500 ml in the present study. Blood transfusion was not required in any of the 14 patients.
In comparison with previous reports, the amount of estimated blood loss with VUS was less than that with other methods for placenta previa and accreta (Table 2). These results indicate that VUS is much more effective for hemostasis, with less intra-operative blood loss than conventional compression sutures.
As to placenta accrete, there were two cases in the present study. In Case 10, it took a few minutes to detach the placenta manually, and persistent bleeding occurred from the remaining placenta, which caused a large amount of bleeding (2100 ml). Notably, after VUS, bleeding stopped completely. In Case 14, as an empirical precaution, VUS was performed immediately on the remaining placenta, and the resultant blood loss was a usual amount of 750 ml. These results strongly suggest that even in placenta accreta, VUS is an effective technique for reducing intraoperative hemorrhaging.
Comparing with PVCS, the characteristics of VUS are summarized below.
1. Additional hemostatic measures are possible.
The internal cavity of the lower uterus is wider even after VUS; therefore, additional hemostatic measures, such as gauze packing, Bakri-balloon tamponade, and PVCS can be easily performed in cases of continued bleeding.
2. The area of blood blockage is localized compared to PVCS. In VUS, the suturing area is localized to one side of the uterine wall with the placental abruption. Therefore, the adverse effects caused by hypoperfusion or ischemic changes within the suturing area, such as wound thinning or suture failure, are less likely to occur during postoperative recovery.
3. It is possible to control the bleeding from the vicinity of the cervical canal. The lower end of the suture reaches the level of the internal uterine ostium, so that it can directly stop the refractory bleeding, which comes from the uterine cervix via the fine collateral channels from the vagina.
4. Ensured cervical patency and avoidance of artery insult. In VUS, the suture is placed on one side of the uterine wall and the needle is inserted away from the uterine artery. Accordingly, cervical patency is ensured and the uterine artery insult is avoidable, with VUS.
5. The suture area is adjustable. Whether the placenta is attached anteriorly, laterally, or posteriorly, VUS can be applied to stop bleeding, by shifting the position of the needle. Furthermore, VUS allows the upper end of the suturing area to be extended cephalad until cover the bleeding area completely,
There are few knacks on how VUS can be performed in practice. First, needle insertion of both the left and right threads at the level of the internal ostium should be performed at the same point in the midline. Second, the tip of the needle should be carried straight backwards, emerging at the midline of the posterior surface of the cervix (Figure 2). These techniques reduce bleeding from the vicinity of the internal ostium and prevent damage to the bilateral uterine arteries. Finally, it is better to perform VUS as early as possible after placental detachment, because, while the surgeon is debating whether to use VUS, bleeding increases and often reaches approximately >2000 ml. VUS is strongly recommended as the first-line treatment for active bleeding, immediately after placental detachment.
Regarding limitations, our study has a bias, which is the small sample size and lack of multivariate analysis to analyze the variable factors. Although the results of our study were superior to those of previous studies, it is necessary to collect more cases and perform multivariate analysis to accurately analyze the effect of VUS.
The present retrospective study focused on the suturing technique. The strength of the present study is that this is the first report of VUS, which is a new technique and an alternative to compression uterine suture, resulting in the least amount of blood loss compared to previous reports
Hemostatic suturing of the bleeding area is a basic clinical procedure and VUS was performed within the scope of this basic technique to stop bleeding in the lower part of the uterus. In addition, compression sutures, which include extensive compression area, are already recognized clinically. Therefore, this minimally invasive VUS is considered clinically necessary and appropriate.
We conclude that VUS is a simple and quick suturing technique with minimal blockage for the control of continuous bleeding in placenta previa or accreta that does not obliterate the lower uterine space and allows for additional hemostatic procedures in laparotomy. We suggest that VUS should be attempted first to obtain reliable hemostasis and prevent critical hemorrhagic damage.
V-shaped uterine suture
parallel vertical compression suture
Ethics approval and consent to participate
This study has been performed in accordance with the Declaration of Helsinki.
We performed this suture within the normal scope of practice and started this study with prior safety assurance.
All patients enrolled in this study provided their written informed consent.
This study was approved by the Ethics Committee of Tokushukai Medical Center. (No.2022-05)
Consent for publication
On admission, written informed consent for publication on an anonymous basis was obtained from the all patient participating in this study.
Availability of data and materials
All authors share these raw data.
The datasets used and/or analyzed during the current study available from the corresponding author on reasonable request.
Competing interests
The authors have no conflicts of interest relevant to this article
Funding
No sources of funding for research involved in this study.
Author contributions
All of the authors are obstetricians and gynecologists who performed cesarean sections, either as a surgeon or as an assistant surgeon.
Acknowledgements
The authors acknowledge all of those involved in the treatment, management, and care of these patients.
Tables 1 to 2 are available in the Supplementary Files section