Experience with Nonemergent Hysterectomy for Placenta Accreta

Introduction

Placenta accreta has become more common in the United States due to a prevailing higher multiple cesarean section rate for the past 20 to 30 years. ¹ The purpose of this article is to report our updated ² experience with the morbidity of nonemergent hysterectomy for placenta accreta and to examine two cohorts over time to see whether there was a significant difference in morbidity.

Materials and Methods

Results

Seventy-two patients were identified in the database. Eleven surgeries that were clearly emergent were excluded, which left 61 patients whose data were available for analysis. The causes for emergent delivery were bleeding (n = 6), premature labor (n = 3), and premature rupture of membranes with suspected chorioamnionitis (n = 2). Patient characteristics are given in Table 1. Diagnosis was suspected on ultrasound scanning in 54 women (15 women also underwent magnetic resonance imaging) and 7 women were diagnosed intraoperatively by direct vision at the time of repeat cesarean section. Twenty-nine of the 61 patients were referred from the region based on the suspected diagnosis. Nineteen of the women were hospitalized for bleeding before the planned delivery date. Although their cesarean section delivery was done at an earlier date than originally planned (median, 4 weeks), in no case was it emergent.

Comparison of patient characteristics and morbidity between the earlier and more contemporary cohort revealed no significant differences (Tables 3 and 4).

Placement of prophylactic arterial catheters was highly variable and documentation of active utilization (inflation of balloon tips) was inconsistent. Because of the inconsistent placement, location, and use of these catheters, it was not felt to be reasonable to attempt analysis of their effectiveness in this study.

Simultaneously with cesarean section delivery, prophylactic ureteral stents were placed successfully bilaterally in 22 women, unilaterally in 2 women, and unsuccessfully in 3 women. There was no morbidity or additional operative time and minimal cost associated with the placement of these stents. As will be reported later, ureteral transection occurred in patients with and without stents. However, there is not a reasonable analysis of the data that could be done in terms of the relative benefit of the stents.

Fifty-eight patients had a vertical skin incision and three had a Cherney incision. Cases were done in the main operating room when available because of more experienced staff and greater accessibility to major surgical equipment. The operative team varied considerably among the cases. Residents and fellows were involved in all cases. A gynecologic oncologist participated in most of the operations but to a highly variable degree. Because of these variations, it is not possible to analyze the potential effects of level of training or specialty on outcome.

Five patients in whom placenta accreta was suspected based on ultrasound results and despite the desire for sterilization and consent for hysterectomy underwent an attempted removal of the placenta immediately after cesarean delivery. This resulted in immediate severe hemorrhage in three women, and hysterectomy was performed promptly in all five women. Estimated blood loss for these cases ranged from 700 to 3500 cc.

During cesarean delivery in a patient with a low anterior placenta and suspected accreta, the placenta was transected extensively. Massive hemorrhage ensued; by the time the uterus was removed, the patient had received 60 U of blood and became severely coagulopathic. The pelvis was packed, and the patient was taken to interventional radiology. Embolization of bleeding vessels was performed, but persistent hemorrhage required reoperation the next day. This patient then had to be kept in the intensive care unit for several days but subsequently did well.

During hysterectomy, one patient with placenta percreta had bilateral distal ureteral transection (stents had been placed); in two other patients with accreta (but suspected percreta) and percreta, the distal left ureter was transected (no stents). In all three cases, there was complete placenta previa that involved the cervix. In these cases, attempted mobilization of the urinary tract was postponed until the last step of the hysterectomy in hopes of devascularizing, mobilizing, and better defining the area of potential percreta. In these cases, the ureters had been dissected to the ureteral tunnels—but not beyond—because of concerns regarding inciting hemorrhage. The planned line of transection of the cardinal ligaments was deliberately kept lateral to the large vascular mass to prevent massive hemorrhage (all four ureteral transections occurred during this part of the operation). In each case, we attempted to open the paravesical spaces medial to the umbilical ligaments; however, the large cervical–placental mass made this difficult. It was understood during these hysterectomies (the same technique was used for many of the other hysterectomies in this series as well) that the ureters were at risk, but it was believed that the benefit of the planned approach (in terms of avoiding massive hemorrhage) outweighed this risk. All four transections were recognized intraoperatively and repaired successfully by ureteroneocystostomy. The placenta of the patient with suspected percreta invaded to within 1 mL of the anterior cervical margin (increta on pathology) but did not seem to involve the bladder, which was separated without hemorrhage.

Two patients suspected of having at least placenta increta preoperatively were noted at the time of surgery to have obvious percreta with placenta extending grossly into the right broad ligament. En bloc resection of the uterus with this broad ligament placenta did not create particular challenges beyond what we were finding with the previa accreta cases.

Incidental cystotomy occurred in 10 patients, all during attempts at careful (to avoid hemorrhage) mobilization of the bladder off a large cervical–placental mass. Five of the cystotomies were unintentional. In the other five patients, the bladder muscularis (midline posterior fundus) appeared to be invaded, and an ∼3 to 5 cm disk of bladder was resected with the uterus. One of these five patients was noted to have placental invasion of the bladder during cystoscopic stent placement. Final pathologic findings confirmed percreta in three of the five cases and increta in the other two. All 10 bladders were repaired primarily and healed uneventfully.

Eight patients had a successful supracervical hysterectomy. In all of these patients, the placenta was clearly above a well-formed cervix. Fifty other patients had a planned total hysterectomy. Three patients had an initial attempt at a supracervical hysterectomy. However, significant bleeding required the immediate removal of the cervix in two patients and removal several hours later in the third patient. In addition to the one patient, five other patients required reoperation within 24 hours for postoperative bleeding.

Mean and median estimated blood loss for the cesarean hysterectomies were 4061 and 3000 mL, respectively (range, 500–30,000 mL). Fifty-two patients (85%) received a blood transfusion during or after surgery. Thirty-one of these patients received four or more units of blood. None of the patients experienced major infectious morbidity. Severe coagulopathy that required component therapy intra- and/or postoperatively developed in eight patients (all after large volume blood transfusion). Component therapy included recombinant factor VIIa in three women. Two of these women who received recombinant factor VIIa experienced subsequent thromboembolism (both received two doses). Three other women developed a postoperative lower extremity deep vein thrombosis and one additional patient had a pulmonary embolism. In total, 33 patients (54%) experienced major morbidity (Table 2).

Overall mean length of stay after surgery was 8 days (range, 3–30 days). Thirty patients required postoperative admission to the intensive care unit for a mean of 5 days (range, 1–18 days).

Nine patients were readmitted to the hospital within 6 to 17 days postoperatively for related issues that included pyelonephritis (one patient), thromboembolism (four patients), soft tissue infection (two patients), ileus (one patient), and cardiac issues (one patient).

Histologic examination of the hysterectomy specimens demonstrated unequivocal placenta accreta (38 specimens), increta (6 specimens), or percreta (12 specimens). In five patients, the pathologic finding initially was interpreted as “no accreta.” However, on rereview, it was believed by the pathologist that all of these patients had placenta accreta (clinically, two patients were thought to have increta based on visualization of the placenta just beneath the surface of the uterine–cervical outer surface).

Comparison of patient characteristics and morbidity between the earlier and more contemporary series revealed no significant differences (Tables 3 and 4).

Discussion

An awareness of the major risk factors for placenta accreta (multiple prior cesarean sections in association with placenta previa) and the widespread utilization of high-quality ultrasound have led to antenatal diagnosis and a drop in maternal morbidity and mortality that has been associated with this condition.^1–5 There were no deaths in this series although the condition continues to contribute substantially to maternal mortality in the United States. The patients in this series were a select group that had an antenatal diagnosis, scheduled surgery, and management at a level IV maternal care center by experienced individuals. Antenatal diagnosis of placenta accreta has major advantages that include the ability to plan all aspects of care.

Patients with placenta accreta are treated generally with hysterectomy, elective or emergent. Uterine preservation, most commonly leaving the placenta in situ, appears to be a viable option. ⁶ Maternal morbidity in the form of hemorrhage and infection is associated with this approach. As such, uterine preservation is most appropriate in the setting of the strong desire to retain child bearing or when substantial operative difficulty is anticipated (complete placenta previa—especially when associated with deep invasion into or through the myometrium, cervical invasion, extensive bladder involvement, or morbid obesity).

The challenges posed by cesarean hysterectomy for placenta accreta include intraoperative hemorrhage and urinary tract injury.^1–5 An increase in procedural difficulty and rate of complications may be expected when there is a complete placenta previa, especially when associated with deep invasion into or through the myometrium. ⁷ It is part of our standard treatment to place ureteral stents electively in these patients. This also gives us an opportunity to evaluate the bladder for possible placental invasion. Other institutions have also recommended prophylactic placement of ureteral stents for these women. ⁵ Although ureteral stents do not always prevent ureteral injury, as seen in the present series, they are easier to recognize. Furthermore, it has been our experience that frequent palpation of the stents during hysterectomy precludes the necessity for more extensive (and potentially hemorrhage inciting) dissection.

To reduce the likelihood of hemorrhage and urinary tract injury during hysterectomy for placenta accreta, surgical technique should include thorough but cautious mobilization of the bladder, judicious traction of the uterus and counter traction of the anterior soft tissues, and tight control of the pedicles against the uterus. Avoiding any type of placental trauma is quite important as even minor placental trauma may lead to massive hemorrhage; however, it may not always be possible to avoid such trauma, especially if the placenta is located anteriorly and impinges on the site of hysterotomy.

Cesarean hysterectomy for a deeply invading placenta is inherently more difficult than other elective cesarean hysterectomies as it is necessary to maintain a safe margin away from the vascular cervical–placental mass and to protect the urinary tract. As the urinary tract must be mobilized without invading the plane of the placenta,^1,4 the operation often assumes features of a modified radical hysterectomy. ⁸

However, when the placenta is clearly above a well-formed cervix and does not extend deeply into the myometrium, the operation is much more straightforward, and a supracervical hysterectomy is appropriate.

Placenta percreta with bladder invasion deserves special comment. This condition may be suspected preoperatively (based on imaging and, occasionally, hematuria) and/or intraoperatively (cystoscopy and/or gross invasion of placenta into the bladder muscularis). When the diagnosis is suspected and the placenta appears to be encroaching on the bladder muscularis, the surgeon should assume that placenta percreta is present. In selected cases (e.g., anticipated loss of a large portion of bladder, unusual surgical difficulty), consideration is given to leaving the placenta in place.^9–11 Attempts to separate the bladder from the uterus and cervix in this instance (even in the absence of overt bladder invasion) may result in massive hemorrhage. Placenta percreta usually involves the lower uterine segment and the mid posterior dome of the bladder. A defined surgical approach by individuals experienced with such cases will help to minimize both urinary tract morbidity and hemorrhage. ⁸

The most serious morbidity that occurred in this series and that has been associated with placenta accreta in general is hemorrhage. Potential strategies to reduce the likelihood of massive hemorrhage include prophylactic arterial catheters, prehysterectomy embolization, uterine conservation with conservative management of the placenta left in situ, abortion hysterectomy (in the rare case in which the diagnosis is suspected strongly early in pregnancy), and delayed hysterectomy.^12–15 Most important are a relatively gentle delivery that avoids trauma to the placenta and meticulous attention to some important surgical principles.^1–5,8 These principles relate to precise lateral control of blood supply and the “no-touch” technique regarding the placenta.

Conclusion

The results of this study and others indicate that elective cesarean hysterectomy for placenta accreta is associated with significant morbidity that is related to hemorrhage and urinary tract injury. Although we continue to gain experience with managing placenta accreta, to date there has not been a reduction in morbidity.