Conservative Surgical Approach for Placenta Accreta Spectrum

Abstract

Placenta accreta spectrum disorder (PAS), which is defined as the situation in which the placenta would not detach after delivery spontaneously, is closely associated with high maternal and neonatal morbidity and mortality resulting from massive bleeding. The prevalence of PAS is increasing globally. When hysterectomy is proposed as the main intervention by international societies, uterine preservation surgery is widely performed in China. Techniques have been developed accordingly, in order to control intraoperative bleeding. In this chapter, we summarize the up-to-date techniques applied in cesarean section for PAS, including precise antenatal diagnosis and assessment (Ultrasound and MRI), preoperative preparation (PAS prenatal grading system and multidisciplinary team), intraoperative hemostasis (applying the Foley catheter on the lower uterine segment, arterial balloon blockade, vascular embolization, artery ligation), modified and/or innovative suture techniques and intraoperative cell salvage.

1. Introduction

Placenta accreta spectrum disorder (PAS) is defined as the situation in which the placenta would not detach after delivery spontaneously, and leads to high maternal and neonatal morbidity and mortality resulting from massive bleeding [1]. According to the pathological characteristics, PAS can be classified into three categories, including placenta creta (PC) when the villi do not invade to the myometrium, placenta increta (PI) when the villi invade into the myometrium, and placenta percreta (PP) when the villi invade throughout the myometrium [1, 2].

Risk factors for PAS were identified as cesarean section (CS), hysteroscopy history, in vitro fertilization and embryo transfer (IVF-ET) and placenta previa, etc. [3, 4, 5, 6, 7]. Jauniaux et al. reported that over 90% of the PAS cases were with prior cesarean delivery [3]. Insufficient decidualization within the scar region triggers the placenta villi to invade further into the myometrium, thus increasing the incidence of PAS [1, 8]. Strong epidemiological data indicated that the rising tendency of PAS is directly associated with the increase of CS rate globally [9]. Even though the World Health Organization (WHO) suggested an ideal CS rate of around 10–15%, CS rate in the real world is rising rapidly from 7% in 1990 to 21% in 2021 [10, 11]. In China, CS rate continuously increases from 28.8% in 2008 to 36.7% in 2018 [12]. The prevalence of PAS in China is 2.2% between 2015 and 2016, which is 10 fold higher than the global PAS incidence (0.17%) [13, 14].

In order to reduce the morbidity and mortality caused by PAS, guidelines were released from several international societies, including Federation of Gynecology and Obstetrics (FIGO) [6, 9, 15, 16, 17], Royal College of Obstetricians and Gynecologists (RCOG) [18], American College of Obstetricians and Gynecologists (ACOG) [19] and Society of Obstetricians and Gynecologists of Canada (SOGC) [20]. Antenatal diagnosis of PAS and standardized management are strongly recommended in all the guidelines. A comprehensive multidisciplinary team (MDT) and expertise in pelvic and abdominal surgeries are essential for patients with PAS [21]. Non-conservative surgical management for PAS is referred to as cesarean hysterectomy, which is considered the most effective way to reduce hemorrhage caused by PAS, especially in health providers with limited access to blood products [17]. In the meanwhile, in order to preserve fertility, approaches to conservative surgical management for PAS have been developed [22, 23]. According to the survey of the Society for Maternal-Fetal Medicine (SMFM), only 15–32% of doctors would apply conservative management for PAS cases [24, 25]. Due to the lack of high-quality clinical trials as well as follow-up studies, standardized surgical management for PAS has not yet been determined.

Conservative surgical management for PAS is mostly accepted in countries, where uterus was associated with woman’s social status and self-esteem. In China, conservative surgery is commonly performed in PAS [26]. A retrospective study from China, which was conducted in 20 hospitals between 2011 and 2015, showed that 82.1% of the PI and PP patients had conservative surgery [7]. A guideline for PAS has been launched from the Chinese Medical Association and the Chinese Medical Doctor Association in 2023, which suggested that cesarean hysterectomy is not necessary for all PAS patients, conservative surgery could be carefully adopted according to precise antenatal diagnosis and optimal intraoperative management [27].

In this chapter, we would like to summarize the up-to-date techniques applied in conservative surgery for PAS, including antenatal diagnosis, preoperative preparation, placenta management, intraoperative hemostasis, modified and/or innovative suture techniques and autologous blood transfusion.

2. Conservative surgery for PAS

2.1 Preoperative evaluation, diagnosis and preparation

Antenatal diagnosis of PAS is highly advisable, which is closely associated with surgery options, bleeding management and success of uterine preservation. Current diagnostic approaches include imaging examination, PAS prenatal grading system and MDT.

2.1.1 Imaging examination: ultrasonography and magnetic resonance imaging (MRI)

Severe complications of PAS (particularly in case of PP), such as substantial hemorrhage and organ injury, are closely related to the placental position and trophoblast invasion depth [28]. Ultrasonography and MRI are major imaging means for prenatal diagnosis.

Ultrasonography is recommended as the primary imaging diagnostic approach for PAS, which can be applied as early as the first trimester [19, 21, 29, 30]. The grayscale ultrasonographic abnormalities include numerous large or irregular vascular lacunae within the placenta, loss of hypoechoic zone between the placenta and myometrium, reduced myometrium thickness and abnormal interface between the uterine serosa and bladder [2, 19, 31]. In the color flow Doppler imaging, hypervascularity within the placenta or myometrium, and bridging vessels between the uterus and bladder are usually found in PAS case [2, 19]. The European Working Group on Abnormally Invasive Placenta proposed standardized definitions of nine common ultrasound findings of PAS in 2016 (Table 1) [32].

Modality	Findings	Description
2D grayscale	Loss of the clear zone	Disappear of the hypoechoic zone between the myometrium and the placental bed
	Myometrial thinning	Less than 1 mm of the myometrial thickness, or undetectable of the myometrium layer
	Placental lacunae or lakes	Irregular, large and numerous sonolucent intraplacental space
	Bladder wall interruption	Irregularity, interruption or loss of the bladder wall or the hyperechoic line between the uterine serosa and the bladder lumen
	Placental bulge	Placenta bulge outward into the surrounding tissue of the uterus
	Exophytic mass	Focal exophytic mass of the placenta invades through the myometrium and the uterine serosa into the adjacent organs
2D color Doppler	Subplacental and/or uterovesical hypervascularity	Excessive dilatation of the uteroplacental circulation in addition to the spiral arteries
	Placental lacunae feeder vessels	Vessels with high velocity blood flow from vessels of the myometrium
	Bridging vessels	Vessels bridging between the uterus and the bladder

Table 1.

Description of main ultrasound findings in PAS [1, 32].

The development of the MRI technique plays an indispensable role in PAS antenatal diagnosis. The major advantage of MRI lies in the assessment of trophoblast invasion topography as well as reviewing the adjacent organs within the pelvis, especially in case of posterior placentation or high maternal body mass index [18, 33]. A meta-study showed that the MRI and ultrasonography shared similar sensitivity (0.89 vs. 0.90, respectively) and specificity (0.87 vs. 0.83, respectively) in PAS diagnosis [34]. Chen et al. reported that the integration of MRI imaging omics analysis, deep learning by artificial intelligence and three-dimensional image reconstruction extends the MRI application in PAS diagnosis, prediction and surgical plan [35]. Palacios-Jaraquemada and his colleagues showed that the comprehensive surgical staging, which combined the ultrasound and MRI findings, increases the efficacy of antenatal diagnosis by 50% [36].

2.1.2 PAS prenatal grading system and surgical risk assessment

In 2015, a grading system for PAS diagnosis was conceived by Collins et al. [37]. Developed from the Collins’ system, the FIGO classification for PAS was performed at delivery [38]. In order to provide prenatal counseling, an ultrasound grading system was generated, which showed a close correlation with the FIGO staging system, surgical outcome and invasion depth [28].

In China, the ultrasound scoring system for PAS established by Zhao et al. is widely used, which includes 8 ultrasonic parameters together with CS history to predict the types of PAS, intraoperative blood loss and hysterectomy odds (Table 2) [27, 39]. A case with a total score between 6 and 9 is predicted as PI, while a case with a total score ≥ 10 is predicted as PP (Figure 1). This system has an accuracy rate of 83.9–92% to predict the pathologic types of PAS [39].

Parameters	0 score	1 score	2 score
Placenta position	Normal	Marginal or low	Complete placental previa
Placental thickness	<3 cm	3–5 cm	>5 cm
Continuity of the clear space	Continuous	Interrupted	Disappeared
Bladder line	Continuous	Interrupted	Disappeared
Lacuna	None	Present	Fused with boiling water sign
Subplacental vascularity	Normal	Increased or as cluster	cross-border sign
Cervical sinus	None	Present	Fused with boiling water sign
Cervical morphology	Complete	Incomplete	Disappeared
CS history	None	Once	≥2 times

Table 2.

Ultrasound scoring system for antenatal diagnosis of PAS [39].

Figure 1.

Images of a patient with PAS. The patient with placenta previa was at 33 weeks of gestation, with a score of 12 in the ultrasound scoring system for preoperative diagnosis of PAS [39]. Images of transabdominal ultrasound longitudinal view (A) and MRI (B) were shown. “P” indicates placenta, “B” indicates bladder.

According to the experience from our center, cases with scores between 6 and 9 usually have delivery between 35 and 37 weeks of gestation. The incidence of platelet transfusion and intraoperative cell salvage (IOCS) is high. For patients with prior abdominal or pelvic surgery history, preoperative administration of ureteral stent is preferable. MDT can be provided when necessary. Postpartum intensive care unit (ICU) admission rate is moderate. For cases with a total score of ≥ 10, delivery can be expected between 34 and 37 weeks of gestation. IOCS, ureteral stent, MDT and balloon occlusion of abdominal aorta should be prepared prior to surgery. After surgery, patients are admitted to ICU. When delivery is inevitable before 34 weeks of gestation, magnesium sulfate is administrated for fetal neuroprotection, and dexamethasone is for fetal lung maturation [27].

One retrospective multi-center study, which included more than 2000 PAS patients, found that the ultrasound scoring system combined with the PAS history can increase the prediction sensitivity and optimize perioperative management [40]. A comprehensive preoperative staging system for PAS is desirable for future application, which combines patient obstetrical history, ultrasound and MRI imaging findings and biomarkers specific to PAS.

2.1.3 Multidisciplinary team (MDT)

It is recommended that PAS patients be managed in medical facilities where the MDT service could be provided, especially for PI and PP cases [6, 27]. PAS-related MDT is composed of experts in medical imaging, obstetrics, anesthesiology, intensive care medicine, interventional radiology, neonatology, transfusion medicine, gynecologic oncology and urology. After revising the case detail, MDT sets up the surgical plan and possible alternatives, including types of PAS, anesthesia means, skin and uterine incision, placental management (complete or partial removal), vessel ligation, blood product preparation, IOCS, cystoscopy evaluation, ureteral stent, balloon occlusion of the abdominal aorta, iliac artery occlusion or embolization, neonatal care and complications.

2.2 Intraoperative management

The purpose for conservative management of PAS patients is to reduce bleeding, avoid organ injury, preserve uterus and maintain uterine function. As the concept of uterine preservation is accepted by more and more practitioners, conservative surgical techniques were developed accordingly.

2.2.1 Skin incision and abdominal adhesion management

The principal for choosing the incision is to get proper exposure of the surgical view in case of massive bleeding, as a result, vertical abdominal incision is frequently used (Figure 2) [19]. FIGO and SOGC guidelines suggested a midline long incision, which ensures the upper uterine segment incision away from the placental margin [21].

Figure 2.

Skin incision. A. Skin incisions for low transverse incision (a) and midline vertical incision (b). B. Surgical view of skin midline vertical incision. “b” indicates the midline.

In patients with prior cesarean delivery, abdominal adhesion is often observed, which might change the pelvic anatomy. The bladder was usually pushed upward to the middle of the uterus and adhesion was formed between the bladder and uterus. Therefore, the location of bladder should be carefully identified to protect the bladder from injury. Frequently, the bladder or bowel is adherent to the peritoneum. It is suggested to start the separation of the peritoneum away from the bladder.

2.2.2 Uterine incision

With respect to the uterine incision, the principal is to keep away from the placenta margin [9]. Most practitioners choose transverse or vertical incisions above the placental margin. For placental position in the lower uterine segment, a “T” sharp incision was proposed, in order to perform hemostasis in the lower uterine segment or cervix. In addition, parallel transverse incision provides another option [41] (Figure 3). The first transverse incision is on the upper uterine segment away from the placental margin, to ensure less blood loss before the fetal delivery. After the fetal delivery, close this transverse incision immediately. The second transverse incision is made around the lower uterine segment. Since the baby is born, surgeons concentrate on the placental invasion and hemostasis. The uterine artery can be temporally stopped, in order to target the bleeding spots around the lower uterine segment or even the cervix. The parallel dual incision allows precise hemostasis, as the bleeding sites were directly observed. In addition, uterine reconstruction and bladder reinforcement can be easily performed [41, 42].

Figure 3.

Parallel transverse incision. A. Upper incision. B. Lower incision.

2.2.3 Assessment of uterine preservation odds

It is of importance to make the intraoperative evaluation of the PAS types and the possibility to preserve the uterus, which is largely dependent on the actual placenta invasion situation and surgeon’s experience. FIGO proposed not to perform conservative surgery for PAS with invasion below the bladder triangle because the success rate is low [17]. However, with the development of devascularization and compression sutures, PAS with bladder triangle invasion can also be considered using the conservative approach. Of note, a good scoring system, which could help to predict the uterine preservation rate and complications related, is needed.

2.2.4 Bladder management

For PAS with placenta invading to the anterior wall of the uterus, dissection between the bladder and the lower uterine segment is required for hemostasis or uterine reconstruction. It is recommended to dissect from the sideway to the midline carefully without forcibly stretching (Figure 4). In case of neovascularization between the uterus and bladder, vessel ligation is performed. If the placenta has invaded into the bladder, partial removal of the bladder wall is needed. Before the separation of the posterior region of the bladder, inject methylene blue or normal sailing into the bladder to make the bladder border visible.

Figure 4.

Blunt dissection of the bladder with finger.

2.2.5 Placenta management

There are three approaches applied in placenta management in PAS, including manual separation of placenta, one-step conservative surgery and leaving the placenta in situ.

From our experience, removing the complete placenta can effectively reduce bleeding, and infection and preserve the uterus. Yang et al. showed that on the premise of sufficient hemostasis and a clear surgical view, the invasive placenta can be dissected completely, which promotes the uterus contraction and acquires favorable outcomes [43]. A practical key point involves gently dissecting the uterine serosa without tearing tissues. When the placenta invades extensively into the uterus and is unable to separate between, it is also possible to leave the placenta in situ (small amount) and monitor the postpartum infection and blood loss. Yang and her colleagues reported that by applying ring butterfly sewing in a case with the placenta leaving in situ (6 mm × 5 mm), the postoperative bleeding and infection were controllable. Ultrasound follow-up in 59 days postpartum revealed few effusions inside the uterus cavity without placental indication, suggesting that the small amount of invasive placenta could detach automatedly and was extracted together with lochia or absorbed.

One-step conservative surgery is referred to remove placenta together with the invaded myometrium and perform uterine reconstruction and/or bladder repair [44]. This method is usually applied in PP case, where dissecting placenta is not possible. One-step conservative surgery has a low risk of secondary bleeding and infection, as compared to total hysterectomy, and the incidence of recurrent PAS is also low (2/108) [9]. Zhao et al. reported a study where 62 cases of PAS were performed with one-step conservative surgery and followed by uterine reconstruction, the intraoperative blood loss and hysterectomy rate was low [45]. Nieto-Calvache and his colleagues showed in a multi-center prospective study that one-step conservative surgery is a safe and valid procedure in most patients with PAS [46].

Leaving the placenta in situ means that after the baby is delivered, cut the umbilical cord close to the placenta insertion and close the uterus without the attempt to remove the placenta. This approach leaves the placenta to detach on its own, therefore, it is not recommended in the case of PP. Antibody administration is required postpartum since the infection incidence is high. In theory, followed by the delivery, blood supply to the pelvic area, uterus and placenta is diminished. Under such circumstances, the trophoblast would undergo necrosis. Placenta, even for invasive placenta, will be detached from the uterus and other organs, and eventually expelled from the vaginal. Given the high incidence of bleeding, sepsis and coagulation dysfunction during this process, close postpartum monitoring is crucial. Using this method, the success rate of uterine preservation is around 78%, while the severe obstetrical complications rate is about 6% [47]. About 20–30% of the patients with this treatment had secondary hysterectomy because of infection and postpartum hemorrhage [7]. As a result, this approach is not recommended in areas with limited medical resources.

2.2.6 Hemostasis

Hemostasis plays a central role in conservative surgery for PAS. Massive bleeding in PAS is resulted from the open vessels followed by the removal of the placenta. Main approaches for hemostasis include uterine devascularization, uterine compression sutures and uterine packing. Frequently, more than one hemostasis strategies are applied, according to the types of PAS and practitioners experience.

2.2.6.1 Uterine devascularization

The purpose of uterine devascularization is to reduce bleeding within the surgical wound and provide a better surgical view. The most frequently used methods include tourniquet on the lower uterine segment, uterine artery ligation, artery balloon occlusion and artery embolization.

Temporarily applying the Foley catheter as a tourniquet on the lower uterine segment is a fast and effective way to stop bleeding (Figure 5). After the fetal delivery, the uterus is pulled out and the lower uterine segment is placed with the Foley catheter. Often, the catheter needs to be loosed every 10–15 min to ensure the blood supply to the normal tissue. Such treatment could also be replaced by Satinsky clamping, which could reach even lower position of the uterus (Figure 6). Uterine artery ligation is commonly used to reduce uterine blood supply, especially in the ascending branch.

Figure 5.

Tourniquet around the lower uterine segment with Foley catheter.

Figure 6.

Satinsky clamping of the uterine artery.

Abdominal aortic balloon occlusion is also widely applied in PAS cases, especially for catastrophic bleeding. Before the operation, a balloon is placed into the abdominal aorta under the guidance of the X-ray or ultrasound [48, 49]. When massive bleeding appears during the placenta removal, normal saline is injected into the balloon to occlude the abdominal aorta. This method allows the operators to perform sutures within 15 min, then the vessel needs to be reopened again. A meta-study, which included 5150 PAS cases, indicated that prophylactic balloon occlusion reduced blood loss volume, blood transfusion volume and hysterectomy rate [50].

Artery embolization (bilateral internal iliac artery or uterine artery) is also considered to be performed in PAS [27], especially during the postpartum period. An absorbable gelatin sponge has been reported as a safe and effective embolic agent, which will be absorbed within 2–6 weeks [51].

2.2.6.2 Uterine compression sutures

Uterine compression sutures, which facilitate hemostasis and reconstruct the uterus wall in the meantime, play an important role in the conservative management of PAS. For PAS limited to the superficial area of the myometrium, local uterine suture is frequently used. Folding sutures are suitable for large and deep invasive cases (e.g. PI or PP), where the thin myometrium layer could hardly support hemostasis and uterine reconstruction. After removing the placenta with large myometrium tissue involved, surgical wound is closed by folding the thin myometrium layer together with the surrounding thick myometrium tissue to reshape the uterine wall. When the lower uterine segment is involved, the suture strategy is to bring the anterior and posterior lower uterine segment together, which stops the bleeding around the lower uterine segment. Different suture strategies are applied in combination, according to the types and positions of PAS, as well as the experiences of the operator. Detailed descriptions of each uterine suture are listed below (Table 3).

Types	PAS position	Practical key points	Advantages	Disadvantages
Circular butterfly suture	Anterior wall of the lower uterine segment.	Suture starts from the posterior to the anterior wall, folds once in the anterior wall and ends from the anterior to posterior wall (Figure 7).	Easy and fast. Restricted to the invaded region [43, 52].	Lack of long-term follow-up data.
Braided suture	Lower uterine segment with thin myometrium.	Suture starts from the cervix and continuously toward the upper uterine segment. Suture goes through the full thickness of the myometrium (Figure 8).	Fast. Good hemostatic effect with lower uterine segment reconstruction [53].	Lack of long-term follow-up data.
Breakwater suture	The posterior wall of the lower uterine segment with substantial myometrium.	A continuous suture is made transverse within the ridge structure of the myometrium layer (Figure 9). The ridge structure is located in the placenta wound and is filled with vessels.	Fast. Good hemostatic effect. Low uterine necrosis risk [54].	Limited hemostatic area. Lack of long-term follow-up data.
Cervical lifting suture	PAS invades the cervical region.	Cervical tissues are lifted with an Allis clamp and sutured with the lower uterine segment (Figure 10).	In situ tissues provide extra materials for compression suture [55, 56].	Risk of bladder injury is high. Long-term effect of cervical malformation cannot be evaluated.
Big 8 suture	Large invaded PP close to the cervix.	The first suture starts 2 mm below the placenta margin, and ends 2 mm above the placenta margin. The second suture is performed 5 mm away from the first one and ligates the two threads together. In addition, the lower uterine segment is ligated with the myometrium of the upper uterine segment (Figure 11).	This is an intrauterine suture method, regardless to abdominal adhesion [57].	For cases with severe abdominal adhesion, suture can cause organ injury.
Uterine spiral suture	Lower uterine segment	The lower uterine segment is divided into 4 areas. Within each area, continuous suture starts from the cervical level (intrauterine) and ends 1 cm higher than the upper bleeding site (Figure 12).	Suture is directly made in the bleeding spots—good hemostatic effect [58, 59].	Limited hemostatic area. Lack of long-term follow-up data.
Nausicaa compression suture	In both anterior or posterior wall of the uterus.	Suture starts from the uterine serosa to encompass the bleeding area, and ends at the other side of the uterine serosa. The sutures penetrated the whole myometrium layer (Figure 13).	Simple and effective [60].	In case of severe pelvic adhesion where the lower uterine segment is difficult to expose, this suture cannot be performed. Lack of long-term follow-up data.
Cho suture	In both the anterior and posterior walls of the uterus.	Transfixes the uterus from anterior to posterior (multiple square) (Figure 14).	Simple and fast. [61]	Uterine necrosis, pyometra, uterine synechiae [62].
Funnel compression suture	Lower uterine segment	The bladder needs to be separated and pushed downward. Suture starts from 1 cm above the upper edge of the cervix, transfixes the anterior and posterior wall of the uterus and returns at 2 cm above the upper border of the lower uterine segment. Then the needle is inserted again at 1 cm above the cesarean incision and emerges at 1 cm below the cesarean incision (Figure 15).	Good hemostasis [63].	For severe intrauterine bleeding cases, the hemostatic effect is not good. Lack of long-term follow-up data.

Table 3.

Summary of uterine compression sutures.

Figure 7.

Circular butterfly suture.

Figure 8.

Braided suture.

Figure 9.

Breakwater suture.

Figure 10.

Cervical lifting suture.

Figure 11.

Big 8 suture.

Figure 12.

Uterine spiral suture.

Figure 13.

Nausicaa compression suture.

Figure 14.

Cho suture.

Figure 15.

Funnel compression suture.

2.2.6.3 Uterine packing

In case of intrauterine oozing after uterine devascularization, intrauterine balloon tamponade or gauze can be applied, such as Bakri and BT-cath [64]. Administration of intrauterine tamponade is around 8–12 h, with the maximal period less than 24 h [65]. Administration of intrauterine gauze is around 24–48 h postpartum, except for patients with infection symptoms (removal of the gauze 12 h postpartum). In the meantime, hemodynamics and patient temperature should be closely monitored.

2.2.7 Intraoperative cell salvage (IOCS)

Compared to the allogeneic blood transfusion, IOCS, which harvests autologous red cells shed while removing the platelets and coagulation factors during surgery, provides a safe and cost-effective strategy for massive hemorrhage [66]. The application of IOCS in obstetrics raised concerns on the risk of amniotic fluid embolus and maternal exposure to fetal blood [66]. The amniotic fluid embolus was resulted from fetal squamous cells, however, the same levels of these cells present in normal maternal circulation at delivery [67]. Additionally, no case of the amniotic fluid embolus in IOCS application has been reported, therefore, this technique would not increase the risk of amniotic fluid embolus [67, 68]. The association of anesthetists guidelines (2018) indicated that there is mixed data to prove the efficacy of leucocyte depletion filters (LDFs) application in obstetrics, given the slow reinfusion flow rate via the LDFs [69]. According to the SALVO study, serious adverse events, such as hypotension, tachycardia and dyspnea, have been observed in LDFs application [70]. The risk of maternal exposure to fetal blood in IOCS cases is increased. Hence, for pregnancy in RhD-negative mums with RhD-positive fetuses, a dose of 1500 IU anti-D immunoglobulin is administrated within 72 h of IOCS [71].

2.3 Workflow of conservative management in PAS

Chandraharan et al. proposed the classical “Triple-P” management in 2012, which includes perioperative placental localization, pelvic devascularization and placental non-separation with myometrial excision and uterine reconstruction [72]. Derived from the “Triple-P” management, we summarized a programmed hemostasis workflow with the updated knowledge (Figure 16). Specifically, this programmed hemostasis workflow starts from the fetal delivery. Temporary hemostasis is applied to reduce the uterine blood supply, including tourniquet around or Satinsky clamping of the lower uterine segment and abdominal aorta or iliac artery balloon occlusion, for manual removal of the placenta. When the placenta cannot be removed completely, the placenta together with the invaded myometrium is dissected before the uterine compression sutures and uterine reconstruction. When the placenta can be removed completely, uterine compression sutures and uterine reconstruction are performed. If the hemostasis is optimal, intrauterine balloon is placed into the uterus and the conservative surgery is ended with uterus preservation. When the bleeding continues, uterine artery is ligated to stop the bleeding. If the bleeding still cannot be controlled, hysterectomy is performed.

Figure 16.

Programmed hemostasis workflow.

3. Complications with conservative management

Conservative management of PAS involves multiple steps, and each approach might induce short- or long-term adverse outcomes. Given that total hysterectomy is recommended for PAS, limited cases of conservative management have been reported.

In the literature, short-term complications with conservative management include postpartum hemorrhage, sepsis, fistula, uterine necrosis, injury to the adjacent organs, deep vein thrombophlebitis, acute pulmonary edema, acute renal dysfunction, secondary hysterectomy and maternal death [9]. Apart from the types of PAS, complications of the conservative treatment are also determined by the surgical strategy and experience of the practitioners. It has been shown that the prolonged intraoperative hemostasis (e.g. Tourniquet applied in lower uterine segment, devascularization), leads to uterine necrosis, infection, uterine synechiae [27]. Pan et al. showed that few postpartum complications occurred in PAS patients with uterine artery ligation and uterine compression suture, including 2% postpartum infection, 2% bladder injury and 0.5% secondary surgery [73].

More follow-up data were coming from the postpartum hemorrhage management. Matsubara et al. reviewed 11 different uterine compression sutures and found that Cho suture is associated with a high rate of uterine necrosis and synechiae, which is attributed to the tightness of compression [62]. Good hemostasis requires compression tightness, which deprives the focal blood supply. Similar findings were reported by Subbaiah et al., which indicated that patients with uterine compression sutures were related to high intrauterine adhesion rate, although the obstetrical outcomes in the subsequent pregnancy were similar [74]. The fertility follow-up study in the use of intrauterine balloon tamponade for severe postpartum hemorrhage showed that similar subsequent pregnancy rate was observed between the treatment and the control group (42.9% vs. 45.9%, P = 0.81) [75]. Doumouchtsis and his colleagues systematically reviewed 28 studies relating to uterine-sparing surgical interventions in severe postpartum hemorrhage, including embolization, artery ligation, compression suture and tamponade [76]. They found that the radiological and surgical techniques would not increase the incidence of adverse outcomes in the following menstruation and fertility.

In the future, large prospective studies are needed to demonstrate the efficacy and safety of each conservative treatment in PAS, especially relating to the uterine function, e.g. subsequent menstruation, pregnancy rate and recurrent PAS.

4. Conclusion

With the development of surgical techniques, total hysterectomy is not the only option for PAS. Conservative management to preserve the uterus is becoming more and more accepted by practitioners. The purpose of conservative management in PAS is to ensure a safe delivery, reduce blood loss and complications and maintain organ function. Large randomized control trials and long-term follow-up studies are needed to evaluate the efficacy and safety of the management approaches in the future.