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Internal Iliac Artery Balloon Tamponade in Placenta Accreta: Outcomes From the Largest Tertiary Accreta Referral Centre in British Columbia
OBSTETRICS
Internal Iliac Artery Balloon Tamponade in Placenta Accreta: Outcomes From the Largest Tertiary Accreta Referral Centre in British Columbia Justin M. McGinnis, MD;* Natasha K. Simula, MD; K.S. Joseph, MD, PhD; Jagdeep S. Ubhi, MD Department of Obstetrics and Gynaecology, University of British Columbia, Vancouver, BC
There were no differences in intensive care unit admission, length of stay, disseminated intravascular coagulation, or operative morbidity. J.M. McGinnis
Abstract Objective: Placenta accreta syndromes are well-recognized risk factors for severe postpartum hemorrhage and are associated with significant maternal morbidity. Internal iliac artery balloon tamponade is an adjunctive procedure used to reduce blood loss at the time of Caesarean hysterectomy with variable results in the reported literature. This study investigated the outcomes of preoperative balloon tamponade at the largest tertiary referral centre for placenta accreta in British Columbia. Methods: Women treated with Caesarean hysterectomy for histologically confirmed placenta accreta from 2003 to 2015 were identified through medical records. A retrospective cohort study was performed after categorizing patients by receipt of internal iliac artery balloon tamponade. Statistically significant differences in clinical variables were assessed using Fisher exact and Mann-Whitney tests. Results: The study population included 24 women. There was no significant difference in the primary outcomes of estimated blood loss or number of units of blood products transfused. Among emergency cases (n = 16), there was a significant reduction in the total number of blood products transfused (3.5 units vs. 15 units, P = 0.04). Operative (P = 0.003) and anaesthetic (P = 0.0001) times were longer among those women undergoing balloon tamponade. Key Word: Placenta accreta; morbidly adherent placenta; hysterectomy; Caesarean delivery; hemorrhage; blood loss; transfusion Corresponding author: Dr. Justin M. McGinnis, Department of Obstetrics and Gynaecology, University of British Columbia, Vancouver, BC. [email protected] Competing interests: See Acknowledgements Received on March 15, 2018 Accepted on June 14, 2018 Available online on October 27, 2018
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Conclusion: Internal iliac artery balloon tamponade decreases blood transfusion requirements among women requiring emergency Caesarean hysterectomy for placenta accreta. Balloon insertion in the operating room may be an important factor in ensuring efficacy of this procedure. Further studies are required to clarify the potential benefits of balloon tamponade in the elective setting.
Résumé Objectif : Le placenta accreta est un facteur de risque bien connu d'hémorragie postpartum grave et il est associé à une morbidité maternelle importante. Le tamponnement par ballonnet de l'artère iliaque interne est une intervention complémentaire utilisée pour réduire la perte sanguine au moment d'une césarienne avec hystérectomie. Les résultats décrits dans la littérature sont variables. Cette étude a examiné les issues du tamponnement par ballonnet préopératoire au plus grand centre régional tertiaire pour le placenta accreta en Colombie-Britannique. Méthodologie : Les femmes ayant subi entre 2003 et 2015 une césarienne avec hystérectomie en raison d'un placenta accreta confirmé histologiquement ont été repérées grâce à leurs dossiers médicaux. Une étude de cohorte rétrospective a été réalisée après un classement des patientes selon qu'elles avaient subi ou non un tamponnement par ballonnet de l'artère iliaque interne. Les différences statistiquement significatives dans les variables cliniques ont été évaluées à l'aide du test exact de Fisher et du test de Mann-Whitney. Résultats : La population étudiée comptait 24 femmes. Il n'y avait pas de différence significative dans les issues primaires quant à la perte sanguine estimée ou au nombre d'unités de produits sanguins transfusés. Parmi les cas d'urgence (n = 16), le tamponnement a entraîné une diminution significative dans le nombre total de produits sanguins transfusés (3,5 unités contre 15 unités, P = 0,04). Le temps opératoire (P = 0,003) et le temps d'anesthésie (P = 0,0001) étaient plus longs chez les femmes qui subissaient un tamponnement. Aucune différence n'a été observée quant aux admissions aux soins intensifs, à la durée de l'hospitalisation, à la coagulation intravasculaire disséminée ou à la morbidité opératoire.
Internal Iliac Artery Balloon Tamponade in Placenta Accreta
Conclusions : Le tamponnement par ballonnet de l'artère iliaque interne diminue le besoin de transfusion sanguine des femmes devant subir une césarienne avec hystérectomie d'urgence en raison d'un placenta accreta. L'insertion du ballonnet dans la salle d'opération pourrait être un facteur important pour assurer l'efficacité de l'intervention. D'autres études sont requises pour préciser les avantages potentiels du tamponnement par ballonnet dans le cas d'interventions planifiées. © 2019 The Society of Obstetricians and Gynaecologists of Canada/La Société des obstétriciens et gynécologues du Canada. Published by Elsevier Inc. All rights reserved.
J Obstet Gynaecol Can 2019;41(4):466 472 https://doi.org/10.1016/j.jogc.2018.06.020
standard of treatment is planned Caesarean hysterectomy with thorough interdisciplinary preoperative assessment.8,9 In recent years, conservative management strategies to preserve the uterus have been shown to be associated with an increased risk of complications including sepsis, fistula formation, and delayed hemorrhage.3,5,10,11 An adjunctive surgical technique includes balloon tamponade of the internal iliac arteries to decrease uterine blood flow temporarily at the time of Caesarean hysterectomy. However, the literature on this technique suggests inconsistent benefits for the management of placenta accreta.12 The purpose of this study was to evaluate the effect of internal iliac artery balloon tamponade on maternal outcomes following Caesarean hysterectomy in the largest tertiary placenta accreta referral centre in British Columbia.
INTRODUCTION
METHODS
Placenta accreta is a severe complication of pregnancy that arises from an abnormal attachment of the placenta to the myometrium. Such abnormal attachment causes the placenta to remain adherent to the uterus during the third stage of labour, and this typically results in severe maternal morbidity and mortality as a result of postpartum hemorrhage.1 3 The term placenta accreta is used both to describe a single pathologic condition (placenta accreta vera) and to describe a disease spectrum that includes placenta accreta vera, placenta increta, and placenta percreta, which reflect varying degrees of placental invasion. The term morbidly adherent placenta is also used to describe this disease spectrum. In this article, the term placenta accreta is used as a broad term to describe all forms of the condition.
We performed a retrospective cohort study comparing outcomes of women with histologically proven placenta accreta managed with or without internal iliac artery balloon tamponade at the time of Caesarean hysterectomy. Primary outcomes included estimated blood loss, need for blood transfusion, number and type of units transfused, change of hemoglobin levels before and after delivery, and initiation of a massive transfusion protocol. Change in hemoglobin was defined as preoperative minus postoperative day 2 hemoglobin. Massive transfusion was defined as requiring greater than 10 units in 24 hours, greater than 4 units in 1 hour, or replacement of greater than 50% total blood volume in 3 hours. Secondary outcomes included volume of fluid replaced, use of cell saver technologies, intensive care unit admission, length of postpartum hospital stay, maternal complications (gluteal necrosis, arterial thrombosis, fistula formation), urinary tract injury, need for re-operation, disseminated intravascular coagulation, death, total anaesthetic time, and total operative time.
Placenta accreta syndromes are well-recognized risk factors for severe postpartum hemorrhage, which remains the leading cause of maternal death worldwide.1 4 Treatment of placenta accreta often requires massive transfusion, intensive care unit admission, and hysterectomy.2 Concerns regarding placenta accreta are increasingly relevant because of the rising incidence of the condition. Women at the highest risk for placenta accreta include those with a history of Caesarean delivery with a current placenta previa. Among women with placenta previa and one, two, three, and four previous Caesarean deliveries, the risk of placenta accreta is 3%, 11%, 41%, and 60%, respectively.5 The rising rate of Caesarean delivery in North America is hypothesized to be the most important cause underlying the increasing incidence of placenta accreta.5 7 Novel and adjunctive techniques for treating placenta accreta have increasing importance. The current surgical
Cases were identified through the Royal Columbian Hospital, Department of Medical Records, using codes for the diagnosis of “placenta accreta” or the procedure “Caesarean hysterectomy.” This case list was validated with a separate list obtained by searching the electronic medical records of relevant obstetricians for the procedure code for “Caesarean hysterectomy.” An attempt was made to obtain all cases from January 1, 2000 through December 31, 2015. However, coding problems in medical records before 2003 meant that patients admitted between January 2000 and March 2003 could not be identified. Therefore, our study period was restricted to the period from April 1, 2003 to December 31, 2015.
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Figure. Final histopathologic diagnosis of placenta accreta, increta, and percreta in women who received and did not receive balloon tamponade. 7
6
6
6 5
5 4
3
3
3
2
were expressed using numbers and proportions (%) for categorical variables and using medians and interquartile ranges for continuous variables. P values were used to guide inference, and a P value of <0.05 was considered significant. Ethics approval was obtained through the University of British Columbia Clinical Research Ethics Board (H15-02902) and the Fraser Health Research Ethics Board (2016-083).
1
1 0 Accreta (n=9)
Increta (n=8)
No balloon tamponade (n=12)
Percreta (n=7)
Balloon tamponade (n=12)
We identified a total of 30 cases of placenta accreta during the study period. Six cases were excluded for factors that affected the risk of hemorrhage or because of the management approach: two cases with twin gestation, three cases of failed conservative management requiring interval Caesarean hysterectomy, and one case of pre-viable delivery at 21 weeks gestational age (GA) as a result of cervical incompetence. Clinical characteristics of patients managed with Caesarean hysterectomy for placenta accreta were compared after stratifying patients by receipt of internal iliac artery balloon tamponade. Stratified analyses were planned to compare outcomes among patients with placenta accreta, increta, and percreta, thus accounting for severity of disease. Analyses were also restricted to women who had an emergency delivery. Statistical analyses were performed using the Fisher exact and Mann-Whitney tests. Differences between groups
RESULTS
Among the 24 women included in the study, the mean age was 33. The median gravidity was four (range two to eight), and the median parity was two (range one to four). Twenty of the women had a previous Caesarean delivery, and the median number of previous Caesarean deliveries was two (range zero to four). Nine women had a history of a dilatation and curettage, one woman had hysteroscopic removal of a uterine septum, and one woman had a previous endometrial ablation. Twenty-two women (92%) had a diagnosis of placenta previa in the current pregnancy. Baseline characteristics of the women in the study cohort stratified by receipt of balloon tamponade are shown in Table 1. The only significant difference between the two groups was related to the GA at antenatal diagnosis of placenta accreta, which occurred earlier in women who underwent balloon tamponade (median GA 27 weeks vs. 31 weeks, P = 0.007). The Figure shows the number of patients diagnosed with placenta accreta, increta, and percreta on final histopathologic examination stratified by receipt of balloon tamponade. There were nine patients with placenta accreta, eight
Table 1. Differences in maternal characteristics and other factors among women who received and did not receive balloon tamponade for placenta accreta Maternal characteristicsa Age Gravidity
P value
No balloon tamponade (n = 12)
95% CI
Balloon tamponade (n = 12)
95% CI
33 (26 37)
31 35
34 (24 44)
29 37
0.3
3.5 (2 6)
2.5 4
3.5 (2 8)
3 5
0.41
Parity
2 (1 3)
1 2
1.91 (1 4)
1 2
0.34
Previous Caesarean delivery, n
1 (0 3)
0 1
2 (1 4)
1 2
0.09
Previous dilatation and curettage, n First trimester hemoglobin, g/L
0 (0 2)
0 1
0 (0 1)
0 1
0.4
127 (113 138)
118 134
132 (113 145)
118 137
0.27
Placenta previa
10 (83%)
51% 97%
12 (100%)
70% 100%
0.23
Antepartum bleeding
5 (42%)
16% 71%
5 (42%)
16% 71%
1.0
GA at diagnosis, weeks
31.6 (23.7 37)
27.9 35
27.1 (17.9 38)
18.3 27.9
0.007b
GA at delivery, weeks
35 (27.9 37.7)
30.9 35.6
33.8 (27 38)
31.4 35.9
0.28
6 (50%)
25% 75%
10 (83%)
51% 97%
0.11
Underwent magnetic resonance imaging CI: confidence interval; GA: gestational age. a
Maternal characteristics presented as median (range) or numbers, proportions (%), and 95% CI. CIs for medians were estimated by bootstrap.
b
Significant value.
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Internal Iliac Artery Balloon Tamponade in Placenta Accreta
Table 2. Primary and secondary maternal outcomes among women who received and did not receive balloon tamponade for placenta accreta Maternal outcomesa
No balloon tamponade (n = 12)
95% CI
Balloon tamponade (n = 12)
95% CI
P value
Estimated blood loss, mL
2750 (1875 3500)
1750 3500
2450 (1500 3125)
1500 3000
0.28
Drop in hemoglobin, g/L
24 (¡2.5 to 29.2)
¡8.5 to 25.5
38 (21 45)
13 38
0.04b
2 (17%)
3% 49%
9 (75%)
43% 93%
0.004b
12 (100%)
70% 100%
10 (83%)
51% 97%
0.47
Use of cell saver, n Required blood transfusion, n
9.5 (4.8 19.2)
4 18.5
5 (2.8 12.0)
2 11
0.41
Packed red blood cell units transfused, n
Total units transfused, n
7 (4.8 12.0)
4 12
5 (2.8 7.5)
1.5 7
0.06
Fresh frozen plasma units transfused, n
1.5 (0 4.2)
0 4.5
0 (0 3)
0 3
0.25
0 (0 1)
0 1
0 (0 0.2)
0 0.5
0.37
Platelet units transfused, n Cryoprecipitate units transfused, n Massive transfusion, n Volume of fluid replacement, mL
0 (0 0.2)
0 0.5
0 (0 0)
0 0
0.34
5 (42%)
16% 71%
4 (33%)
11% 65%
1.00
5643 (4818 8088)
4750 7980
5775 (4984 8973)
4940 8830
0.31
Total operative time, min
129 (100 164)
95 161
194 (151 243)
149 241
0.003b
Total anaesthetic time, min
171 (136 206)
116 210
257 (225 293)
209 291
0.0001b
Disseminated intravascular coagulation, n
1 (8%)
0.4% 40%
1 (8%)
0.4% 40%
1.00
Intensive care unit admission, n
2 (17%)
3% 49%
3 (25%)
7% 57%
1.00
Length of intensive care unit admission, days
0 (0 0)
0 0
0 (0 0.2)
0 0.5
0.41
5.5 (3.8 8.2)
3 8
6 (5 8.2)
5 7.5
0.39
Re-operation required, n
1 (8%)
0.4% 40%
1 (8%)
0.4% 40%
1.00
Urinary tract injury, n
3 (25%)
7% 57%
5 (42%)
16% 71%
0.67
0
—
0
—
1.00
Length of postoperative stay, days
Maternal death, n CI: confidence interval.
a Maternal outcomes presented as median (interquartile range) or numbers, proportions (%), and 95% CI. P value was calculated with Mann-Whitney test for continuous variables and with Fisher exact test for categorical variables. CIs for medians were estimated by bootstrap. b
Significant value.
patients with placenta increta, and seven patients with placenta percreta. Placenta percreta was more common in the balloon-treated group (6 vs. 1, P = 0.02). Twelve women in the study cohort underwent balloon tamponade, and 12 women did not. Differences in primary and secondary outcomes between women who underwent balloon tamponade and those who did not are shown in Table 2. Estimated blood loss (2450 mL vs. 2750 mL) and the number of units of blood products transfused (5 vs. 9.5) were lower among women who underwent balloon tamponade. However, these differences were not statistically significant. There was a significant difference in drop of hemoglobin between the two groups (24 g/L vs. 38 g/L, P = 0.04), with the decrease being larger among the women who had balloon tamponade. Patients undergoing balloon tamponade were more likely to have cell saver technologies used during their procedure (17% vs. 75%, P = 0.004), have longer operative times (129 minutes vs. 194 minutes, P = 0.003), and a longer duration of anaesthesia (171 minutes vs. 257 minutes, P = 0.0001). There were
no differences in admission to or length of stay in the intensive care unit, total length of postoperative stay, or associated maternal morbidities (disseminated intravascular coagulation, reoperation, urinary tract injury). There were no complications associated with balloon tamponade (e.g., gluteal necrosis, arterial thrombosis, or fistula) or maternal deaths in either group. Restricted analysis of the 16 women managed with emergency delivery is shown in Table 3. Women in this subgroup presented to the delivery suite at a median GA of 33+6 (range 31+2 to 35+2). Reasons for emergency delivery included antepartum hemorrhage, spontaneous onset of labour, and premature rupture of the membranes. There was a significant reduction in the composite outcome of total number of blood products transfused among women undergoing balloon tamponade (3.5 units vs. 15 units, P = 0.04). This appears to be largely driven by a reduction in the number of packed red blood cell units transfused (3.5 units vs. 9.5 units, P = 0.06). There were no significant differences in transfusion of fresh
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Table 3. Primary and secondary maternal outcomes among women delivered via emergency Caesarean hysterectomy who received and did not receive balloon tamponade for placenta accreta Maternal outcomesa
P value
No balloon tamponade (n = 10)
95% CI
Balloon tamponade (n = 6)
95% CI
Estimated blood loss, mL
3000 (2125 3500)
2000 to 3500
1950 (1500 2850)
1000 3000
0.12
Drop in hemoglobin, g/L
24 (¡1.8 to 26.2)
¡10 to 25.5
38 (19 40)
13 40
0.17
Use of cell saver, n
1 (10%)
0.5% 46%
3 (50%)
19% 81%
0.12
10 (100%)
66% 100%
5 (83%)
36% 99%
0.38
Total units transfused, n
15 (4.2 19.8)
3 20
3.5 (2.2 3.8)
1 11
0.04b
Packed red blood cell units transfused, n
9.5 (4.2 12)
3 12
3.5 (2.2 5.5)
1 6
0.06
Fresh frozen plasma units transfused, n
3 (0 4.8)
0 5
0 (0 1.5)
0 2
0.08
0 (0 1)
0 1.5
0 (0 0)
0 0.5
0.21
Required blood transfusion, n
Platelet units transfused, n Cryoprecipitate units transfused, n Massive transfusion, n Volume of fluid replacement, mL
0 (0 0.8)
0 2.5
0 (0 0)
0 0
0.18
5 (50%)
23% 85%
1 (17%)
0.9% 64%
0.31
5642 (4943 8313)
3600 8500
7215 (5150 8958)
4150 9000
0.27
Total operative time, min
136 (102 171)
88.5 172
156 (135 181)
88 188
0.12
Total anaesthetic time, min
175 (124 225)
111 234
220 (200 238)
196 258
0.01b
Disseminated intravascular coagulation, n
1 (10%)
0.5% 46%
2 (33%)
6% 76%
0.52
Intensive care unit admission, n
2 (20%)
4% 56%
0 (0%)
0% 48%
0.50
Length of intensive care unit admission, days
0 (0 0)
0 0.5
0 (0 0)
0 0
0.27
7 (5 8.8)
4 9
6 (5 8.5)
5 9
0.38
Re-operation required, n
1 (10%)
0.5% 46%
0 (0%)
0 48%
1.00
Urinary tract injury, n
3 (30%)
8% 65%
2 (33%)
6% 76%
1.00
0
—
0
—
1.00
Length of postoperative stay, days
Maternal death, n CI: confidence interval.
a Maternal outcomes presented as median (interquartile range) or numbers, proportions (%), and 95% CI. P value was calculated with Mann-Whitney test for continuous variables and with Fisher exact test for categorical variables CIs for medians were estimated by bootstrap. b
Significant value.
frozen plasma, platelets, or cryoprecipitate. Women undergoing balloon tamponade had a longer duration of anaesthesia (220 minutes vs. 175 minutes, P = 0.01). DISCUSSION
This study represents the largest Canadian cohort of women with placenta accreta managed with Caesarean hysterectomy and internal iliac artery balloon tamponade. Our study shows that the use of internal iliac artery balloons is associated with lower rates of estimated blood loss and lower blood transfusion requirements than in controls in our greater cohort. These differences were not statistically significant in our greater cohort, although a similar and statistically significant reduction in transfusion occurred among women with placenta accreta who were delivered on an emergency basis. Total operative and anaesthetic times were longer for women who underwent balloon tamponade, and there were no complications associated with the use of this technology.
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Despite the increasing incidence of placenta accreta syndromes, the optimal management strategy to reduce maternal morbidity has not been determined. Different approaches have been described in the literature, including conservative management with uterine preservation,3,10,11 and planned Caesarean hysterectomy with or without adjunctive procedures such as balloon tamponade or uterine artery embolization.2,9,12,13 Our study suggests that balloon tamponade is safe, and the reduced blood loss and transfusion requirements associated with the procedure indicate that it may be the preferred management strategy. The Royal Columbian Hospital in New Westminster, British Columbia, has become a specialized placenta accreta centre of excellence. Patients are managed by a multidisciplinary team because this strategy has consistently shown excellent patient outcomes.8,9 Internal iliac artery balloon tamponade before elective Caesarean hysterectomy has become our preferred management approach. On the basis of the placenta previa literature,14 patients with placenta accreta are scheduled for delivery at 36 weeks gestation in
Internal Iliac Artery Balloon Tamponade in Placenta Accreta
an effort to minimize both maternal and neonatal morbidity. In the operating room the interventional radiologist inserts bilateral internal iliac artery balloons, and the balloons are left deflated. Caesarean delivery is performed. After delivery of the fetus, the balloons are inflated, the placenta is left undisturbed, and immediate hysterectomy follows. Once hysterectomy is completed, the balloons are deflated, and hemostasis is confirmed. Iliac artery balloons are removed after abdominal closure. In 2006 an advanced, fluoroscopically enabled operating room was built, enabling insertion of iliac balloons with the patient in optimal position on the operating table. Of those women in our cohort who underwent balloon tamponade, 11 patients (92%) were managed exclusively in the fluoroscopically enabled operating room. To our knowledge, this is the only published cohort of women managed with balloon tamponade in the operating room, thus obviating the need for patient transfer and repositioning. Subsequent patient transfer may lead to balloon displacement and may have been responsible for the reported lack of benefit of balloon tamponade in previous studies.12,15,16 Community-based sites face unique challenges in how to manage an undiagnosed placenta accreta recognized only at the time of Caesarean delivery. Expert opinion favours performing a stabilizing procedure and transferring the patient to a higher level of care, should maternal and fetal status allow such a delay.2 Alternatively, a hysterotomy can be made well above the placenta, the placenta is left undisturbed, the uterus and abdomen are closed, and the patient is transferred to a higher level of care for expert consultation. In our study population estimated blood loss and blood transfusion were reduced in all patients undergoing balloon tamponade. However, these differences were statistically significant only when the study population was restricted to patients undergoing emergency Caesarean delivery. Confounding by indication (i.e., the higher severity of placenta accreta in the balloon tamponade group) (Figure) likely explains the lack of significance in the unrestricted study population. The relatively small study size, the increased use of cell saver technologies in the balloon-treated group, and the lower blood loss associated with elective Caesarean delivery are other potential explanations for the differences in findings between the overall study population and emergency cases.17 Although our study represents the largest Canadian cohort of women with placenta accreta managed with Caesarean hysterectomy and internal iliac artery balloon tamponade, the small sample size may introduce both type 1 and type 2 statistical errors. Conducting multiple
analyses on a small sample of data may increase the likelihood of type 1 error. Furthermore, the sample size may be too small to detect some biologically significant effects (type 2 error). Two previous studies of varying size (nine and 69 cases, respectively) evaluated balloon tamponade and failed to show reductions in estimated blood loss and blood transfusion.15,16 However, in both these studies patients were transported to the operating room after insertion of the iliac artery balloons, and this practice may have dislodged the balloon catheters. Two other studies reported significant reductions in estimated blood loss and blood transfusion following balloon tamponade for placenta accreta18,19; the first was a retrospective review of 25 cases,18 and the second was a prospective follow up of 163 cases.19 These studies were limited by the lack of histopathologic confirmation of the diagnosis of placenta accreta, with less than one half of the cases subjected to pathologic examination in the first study18 and only 6% in the second study.19 Sixty-seven percent (n = 16) of cases in our cohort were managed with emergency delivery. Because the majority of these women presented with unstable placenta previa-accreta they were at extremely high risk of hemorrhage. These women presented at a median GA of 33 +6 weeks. Planning elective delivery at 35 weeks, as opposed to the current practice of scheduled delivery at 36 weeks, would have prevented the emergency delivery of five additional cases. Such a change should be considered because it has the potential to further reduce maternal morbidity from placenta accreta. The strengths of our study include uniform pathologic diagnosis with routine hysterectomy in all cases, a high rate of antenatal diagnosis, management in a multidisciplinary centre with significant expertise in the diagnosis and management of placenta accreta, and placement of iliac artery balloons in the operating room, thereby obviating the need for patient transfer or repositioning. Study limitations include small size, a higher incidence of placenta percreta in the intervention group, and a high overall rate of emergency procedures. The latter limitation may necessitate a review of the optimal timing of planned delivery. Further research is required to evaluate the benefit of internal iliac artery balloon tamponade in the elective setting. CONCLUSION
Internal iliac artery balloon tamponade decreases blood transfusion requirements for patients following emergency
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Caesarean hysterectomy for placenta accreta. Insertion of internal iliac artery balloons in the operating room, which obviates the need for patient transfer and prevents potential displacement of the balloons, may be an important factor in ensuring efficacy of this procedure. Further studies are needed to clarify the benefit of balloon tamponade in the elective setting and to identify the optimal timing of scheduled delivery for women with placenta accreta.
7. Silver RM. Implications of the first cesarean: perinatal and future reproductive health and subsequent cesareans, placentation issues, uterine rupture risk, morbidity, and mortality. Semin Perinatol 2012;36:315–23. 8. Silver RM, Fox KA, Barton JR, et al. Center of excellence for placenta accreta. AM J Obstet Gynecol 2015;5:561–8. 9. Eller AG, Nennett MA, Sharshiner M, et al. Maternal morbidity in cases of placenta accreta managed by a multidisciplinary team compared with standard obstetric care. Obstet Gynecol 2011;117:331–7. 10. Amsalem H, Kingdom J, Farine D, et al. Planned cesarean hysterectomy versus “conserving” cesarean section in patients with placenta accreta. J Obstet Gynaecol Can 2011;33:1005–10.
Acknowledgements
This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. There are no conflicts of interest to declare. The views represented in this manuscript are of the authors own and do not represent the institutions in which the research was conducted. The authors would like to thank Arianne Albert from the Women’s Health Research Institute for her expertise in statistical analysis.
11. D’Souza DL, Kingdom JC, Amsalem H, et al. Conservative management of invasive placenta using combined prophylactic internal iliac artery balloon occlusion and immediate postoperative uterine artery embolization. Can Assoc Radiol J 2015;66:179–84. 12. Dilauro MD, Dason S, Athreya S. Prophylactic balloon occlusion of internal iliac arteries in women with placenta accreta: literature review and analysis. Clin Radiol 2012;67:515–20. 13. Angstman T, Gard G, Harrington T, et al. Surgical management of placenta accreta. Am J Obstet Gynecol 2010;202:38.e1–9. 14. Blackwell SC. Timing of delivery for women with stable placenta previa. Semin Perinatol 2011;35:249–51.
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17. Chua S, Joung S, Aziz R. Incidence and risk factors predicting blood transfusion in caesarean section. Aust N Z J Obstet Gynaecol 2009; 49:490–2.
4. Mehrabadi A, Hutcheon JA, Liu S, et al. Impact of placenta accreta on the incidence of postpartum hemorrhage and severe postpartum hemorrhage. Obstet Gynecol 2015;125:814–21.
18. Tan CH, Tay KH, Sheah K, et al. Perioperative endovascular internal iliac artery occlusion placement in management of placenta accreta. AJR Am J Roentgenol 2007;189:1158–63.
5. Silver RM, Landon MB, Rouse DJ, et al. Maternal morbidity associated with multiple repeat cesarean deliveries. Obstet Gynecol 2006;107:1226–32.
19. Fan Y, Gong X, Wang N, et al. A prospective observational study evaluating the efficacy of prophylactic internal iliac artery balloon catheterization in the management of placenta previa-accreta: a STROBE compliant article. Medicine (Baltimore) 2017;96:e8276.
6. Klar M, Michels KB. Cesarean section and placental disorders in subsequent pregnancies a meta-analysis. J Perinat Med 2014;42:571–83.
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Internal Iliac Artery Balloon Tamponade in Placenta Accreta: Outcomes From the Largest Tertiary Accreta Referral Centre in British Columbia Justin M. McGinnis, MD;* Natasha K. Simula, MD; K.S. Joseph, MD, PhD; Jagdeep S. Ubhi, MD Department of Obstetrics and Gynaecology, University of British Columbia, Vancouver, BC
There were no differences in intensive care unit admission, length of stay, disseminated intravascular coagulation, or operative morbidity. J.M. McGinnis
Abstract Objective: Placenta accreta syndromes are well-recognized risk factors for severe postpartum hemorrhage and are associated with significant maternal morbidity. Internal iliac artery balloon tamponade is an adjunctive procedure used to reduce blood loss at the time of Caesarean hysterectomy with variable results in the reported literature. This study investigated the outcomes of preoperative balloon tamponade at the largest tertiary referral centre for placenta accreta in British Columbia. Methods: Women treated with Caesarean hysterectomy for histologically confirmed placenta accreta from 2003 to 2015 were identified through medical records. A retrospective cohort study was performed after categorizing patients by receipt of internal iliac artery balloon tamponade. Statistically significant differences in clinical variables were assessed using Fisher exact and Mann-Whitney tests. Results: The study population included 24 women. There was no significant difference in the primary outcomes of estimated blood loss or number of units of blood products transfused. Among emergency cases (n = 16), there was a significant reduction in the total number of blood products transfused (3.5 units vs. 15 units, P = 0.04). Operative (P = 0.003) and anaesthetic (P = 0.0001) times were longer among those women undergoing balloon tamponade. Key Word: Placenta accreta; morbidly adherent placenta; hysterectomy; Caesarean delivery; hemorrhage; blood loss; transfusion Corresponding author: Dr. Justin M. McGinnis, Department of Obstetrics and Gynaecology, University of British Columbia, Vancouver, BC. [email protected] Competing interests: See Acknowledgements Received on March 15, 2018 Accepted on June 14, 2018 Available online on October 27, 2018
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Conclusion: Internal iliac artery balloon tamponade decreases blood transfusion requirements among women requiring emergency Caesarean hysterectomy for placenta accreta. Balloon insertion in the operating room may be an important factor in ensuring efficacy of this procedure. Further studies are required to clarify the potential benefits of balloon tamponade in the elective setting.
Résumé Objectif : Le placenta accreta est un facteur de risque bien connu d'hémorragie postpartum grave et il est associé à une morbidité maternelle importante. Le tamponnement par ballonnet de l'artère iliaque interne est une intervention complémentaire utilisée pour réduire la perte sanguine au moment d'une césarienne avec hystérectomie. Les résultats décrits dans la littérature sont variables. Cette étude a examiné les issues du tamponnement par ballonnet préopératoire au plus grand centre régional tertiaire pour le placenta accreta en Colombie-Britannique. Méthodologie : Les femmes ayant subi entre 2003 et 2015 une césarienne avec hystérectomie en raison d'un placenta accreta confirmé histologiquement ont été repérées grâce à leurs dossiers médicaux. Une étude de cohorte rétrospective a été réalisée après un classement des patientes selon qu'elles avaient subi ou non un tamponnement par ballonnet de l'artère iliaque interne. Les différences statistiquement significatives dans les variables cliniques ont été évaluées à l'aide du test exact de Fisher et du test de Mann-Whitney. Résultats : La population étudiée comptait 24 femmes. Il n'y avait pas de différence significative dans les issues primaires quant à la perte sanguine estimée ou au nombre d'unités de produits sanguins transfusés. Parmi les cas d'urgence (n = 16), le tamponnement a entraîné une diminution significative dans le nombre total de produits sanguins transfusés (3,5 unités contre 15 unités, P = 0,04). Le temps opératoire (P = 0,003) et le temps d'anesthésie (P = 0,0001) étaient plus longs chez les femmes qui subissaient un tamponnement. Aucune différence n'a été observée quant aux admissions aux soins intensifs, à la durée de l'hospitalisation, à la coagulation intravasculaire disséminée ou à la morbidité opératoire.
Internal Iliac Artery Balloon Tamponade in Placenta Accreta
Conclusions : Le tamponnement par ballonnet de l'artère iliaque interne diminue le besoin de transfusion sanguine des femmes devant subir une césarienne avec hystérectomie d'urgence en raison d'un placenta accreta. L'insertion du ballonnet dans la salle d'opération pourrait être un facteur important pour assurer l'efficacité de l'intervention. D'autres études sont requises pour préciser les avantages potentiels du tamponnement par ballonnet dans le cas d'interventions planifiées. © 2019 The Society of Obstetricians and Gynaecologists of Canada/La Société des obstétriciens et gynécologues du Canada. Published by Elsevier Inc. All rights reserved.
J Obstet Gynaecol Can 2019;41(4):466 472 https://doi.org/10.1016/j.jogc.2018.06.020
standard of treatment is planned Caesarean hysterectomy with thorough interdisciplinary preoperative assessment.8,9 In recent years, conservative management strategies to preserve the uterus have been shown to be associated with an increased risk of complications including sepsis, fistula formation, and delayed hemorrhage.3,5,10,11 An adjunctive surgical technique includes balloon tamponade of the internal iliac arteries to decrease uterine blood flow temporarily at the time of Caesarean hysterectomy. However, the literature on this technique suggests inconsistent benefits for the management of placenta accreta.12 The purpose of this study was to evaluate the effect of internal iliac artery balloon tamponade on maternal outcomes following Caesarean hysterectomy in the largest tertiary placenta accreta referral centre in British Columbia.
INTRODUCTION
METHODS
Placenta accreta is a severe complication of pregnancy that arises from an abnormal attachment of the placenta to the myometrium. Such abnormal attachment causes the placenta to remain adherent to the uterus during the third stage of labour, and this typically results in severe maternal morbidity and mortality as a result of postpartum hemorrhage.1 3 The term placenta accreta is used both to describe a single pathologic condition (placenta accreta vera) and to describe a disease spectrum that includes placenta accreta vera, placenta increta, and placenta percreta, which reflect varying degrees of placental invasion. The term morbidly adherent placenta is also used to describe this disease spectrum. In this article, the term placenta accreta is used as a broad term to describe all forms of the condition.
We performed a retrospective cohort study comparing outcomes of women with histologically proven placenta accreta managed with or without internal iliac artery balloon tamponade at the time of Caesarean hysterectomy. Primary outcomes included estimated blood loss, need for blood transfusion, number and type of units transfused, change of hemoglobin levels before and after delivery, and initiation of a massive transfusion protocol. Change in hemoglobin was defined as preoperative minus postoperative day 2 hemoglobin. Massive transfusion was defined as requiring greater than 10 units in 24 hours, greater than 4 units in 1 hour, or replacement of greater than 50% total blood volume in 3 hours. Secondary outcomes included volume of fluid replaced, use of cell saver technologies, intensive care unit admission, length of postpartum hospital stay, maternal complications (gluteal necrosis, arterial thrombosis, fistula formation), urinary tract injury, need for re-operation, disseminated intravascular coagulation, death, total anaesthetic time, and total operative time.
Placenta accreta syndromes are well-recognized risk factors for severe postpartum hemorrhage, which remains the leading cause of maternal death worldwide.1 4 Treatment of placenta accreta often requires massive transfusion, intensive care unit admission, and hysterectomy.2 Concerns regarding placenta accreta are increasingly relevant because of the rising incidence of the condition. Women at the highest risk for placenta accreta include those with a history of Caesarean delivery with a current placenta previa. Among women with placenta previa and one, two, three, and four previous Caesarean deliveries, the risk of placenta accreta is 3%, 11%, 41%, and 60%, respectively.5 The rising rate of Caesarean delivery in North America is hypothesized to be the most important cause underlying the increasing incidence of placenta accreta.5 7 Novel and adjunctive techniques for treating placenta accreta have increasing importance. The current surgical
Cases were identified through the Royal Columbian Hospital, Department of Medical Records, using codes for the diagnosis of “placenta accreta” or the procedure “Caesarean hysterectomy.” This case list was validated with a separate list obtained by searching the electronic medical records of relevant obstetricians for the procedure code for “Caesarean hysterectomy.” An attempt was made to obtain all cases from January 1, 2000 through December 31, 2015. However, coding problems in medical records before 2003 meant that patients admitted between January 2000 and March 2003 could not be identified. Therefore, our study period was restricted to the period from April 1, 2003 to December 31, 2015.
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Figure. Final histopathologic diagnosis of placenta accreta, increta, and percreta in women who received and did not receive balloon tamponade. 7
6
6
6 5
5 4
3
3
3
2
were expressed using numbers and proportions (%) for categorical variables and using medians and interquartile ranges for continuous variables. P values were used to guide inference, and a P value of <0.05 was considered significant. Ethics approval was obtained through the University of British Columbia Clinical Research Ethics Board (H15-02902) and the Fraser Health Research Ethics Board (2016-083).
1
1 0 Accreta (n=9)
Increta (n=8)
No balloon tamponade (n=12)
Percreta (n=7)
Balloon tamponade (n=12)
We identified a total of 30 cases of placenta accreta during the study period. Six cases were excluded for factors that affected the risk of hemorrhage or because of the management approach: two cases with twin gestation, three cases of failed conservative management requiring interval Caesarean hysterectomy, and one case of pre-viable delivery at 21 weeks gestational age (GA) as a result of cervical incompetence. Clinical characteristics of patients managed with Caesarean hysterectomy for placenta accreta were compared after stratifying patients by receipt of internal iliac artery balloon tamponade. Stratified analyses were planned to compare outcomes among patients with placenta accreta, increta, and percreta, thus accounting for severity of disease. Analyses were also restricted to women who had an emergency delivery. Statistical analyses were performed using the Fisher exact and Mann-Whitney tests. Differences between groups
RESULTS
Among the 24 women included in the study, the mean age was 33. The median gravidity was four (range two to eight), and the median parity was two (range one to four). Twenty of the women had a previous Caesarean delivery, and the median number of previous Caesarean deliveries was two (range zero to four). Nine women had a history of a dilatation and curettage, one woman had hysteroscopic removal of a uterine septum, and one woman had a previous endometrial ablation. Twenty-two women (92%) had a diagnosis of placenta previa in the current pregnancy. Baseline characteristics of the women in the study cohort stratified by receipt of balloon tamponade are shown in Table 1. The only significant difference between the two groups was related to the GA at antenatal diagnosis of placenta accreta, which occurred earlier in women who underwent balloon tamponade (median GA 27 weeks vs. 31 weeks, P = 0.007). The Figure shows the number of patients diagnosed with placenta accreta, increta, and percreta on final histopathologic examination stratified by receipt of balloon tamponade. There were nine patients with placenta accreta, eight
Table 1. Differences in maternal characteristics and other factors among women who received and did not receive balloon tamponade for placenta accreta Maternal characteristicsa Age Gravidity
P value
No balloon tamponade (n = 12)
95% CI
Balloon tamponade (n = 12)
95% CI
33 (26 37)
31 35
34 (24 44)
29 37
0.3
3.5 (2 6)
2.5 4
3.5 (2 8)
3 5
0.41
Parity
2 (1 3)
1 2
1.91 (1 4)
1 2
0.34
Previous Caesarean delivery, n
1 (0 3)
0 1
2 (1 4)
1 2
0.09
Previous dilatation and curettage, n First trimester hemoglobin, g/L
0 (0 2)
0 1
0 (0 1)
0 1
0.4
127 (113 138)
118 134
132 (113 145)
118 137
0.27
Placenta previa
10 (83%)
51% 97%
12 (100%)
70% 100%
0.23
Antepartum bleeding
5 (42%)
16% 71%
5 (42%)
16% 71%
1.0
GA at diagnosis, weeks
31.6 (23.7 37)
27.9 35
27.1 (17.9 38)
18.3 27.9
0.007b
GA at delivery, weeks
35 (27.9 37.7)
30.9 35.6
33.8 (27 38)
31.4 35.9
0.28
6 (50%)
25% 75%
10 (83%)
51% 97%
0.11
Underwent magnetic resonance imaging CI: confidence interval; GA: gestational age. a
Maternal characteristics presented as median (range) or numbers, proportions (%), and 95% CI. CIs for medians were estimated by bootstrap.
b
Significant value.
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Internal Iliac Artery Balloon Tamponade in Placenta Accreta
Table 2. Primary and secondary maternal outcomes among women who received and did not receive balloon tamponade for placenta accreta Maternal outcomesa
No balloon tamponade (n = 12)
95% CI
Balloon tamponade (n = 12)
95% CI
P value
Estimated blood loss, mL
2750 (1875 3500)
1750 3500
2450 (1500 3125)
1500 3000
0.28
Drop in hemoglobin, g/L
24 (¡2.5 to 29.2)
¡8.5 to 25.5
38 (21 45)
13 38
0.04b
2 (17%)
3% 49%
9 (75%)
43% 93%
0.004b
12 (100%)
70% 100%
10 (83%)
51% 97%
0.47
Use of cell saver, n Required blood transfusion, n
9.5 (4.8 19.2)
4 18.5
5 (2.8 12.0)
2 11
0.41
Packed red blood cell units transfused, n
Total units transfused, n
7 (4.8 12.0)
4 12
5 (2.8 7.5)
1.5 7
0.06
Fresh frozen plasma units transfused, n
1.5 (0 4.2)
0 4.5
0 (0 3)
0 3
0.25
0 (0 1)
0 1
0 (0 0.2)
0 0.5
0.37
Platelet units transfused, n Cryoprecipitate units transfused, n Massive transfusion, n Volume of fluid replacement, mL
0 (0 0.2)
0 0.5
0 (0 0)
0 0
0.34
5 (42%)
16% 71%
4 (33%)
11% 65%
1.00
5643 (4818 8088)
4750 7980
5775 (4984 8973)
4940 8830
0.31
Total operative time, min
129 (100 164)
95 161
194 (151 243)
149 241
0.003b
Total anaesthetic time, min
171 (136 206)
116 210
257 (225 293)
209 291
0.0001b
Disseminated intravascular coagulation, n
1 (8%)
0.4% 40%
1 (8%)
0.4% 40%
1.00
Intensive care unit admission, n
2 (17%)
3% 49%
3 (25%)
7% 57%
1.00
Length of intensive care unit admission, days
0 (0 0)
0 0
0 (0 0.2)
0 0.5
0.41
5.5 (3.8 8.2)
3 8
6 (5 8.2)
5 7.5
0.39
Re-operation required, n
1 (8%)
0.4% 40%
1 (8%)
0.4% 40%
1.00
Urinary tract injury, n
3 (25%)
7% 57%
5 (42%)
16% 71%
0.67
0
—
0
—
1.00
Length of postoperative stay, days
Maternal death, n CI: confidence interval.
a Maternal outcomes presented as median (interquartile range) or numbers, proportions (%), and 95% CI. P value was calculated with Mann-Whitney test for continuous variables and with Fisher exact test for categorical variables. CIs for medians were estimated by bootstrap. b
Significant value.
patients with placenta increta, and seven patients with placenta percreta. Placenta percreta was more common in the balloon-treated group (6 vs. 1, P = 0.02). Twelve women in the study cohort underwent balloon tamponade, and 12 women did not. Differences in primary and secondary outcomes between women who underwent balloon tamponade and those who did not are shown in Table 2. Estimated blood loss (2450 mL vs. 2750 mL) and the number of units of blood products transfused (5 vs. 9.5) were lower among women who underwent balloon tamponade. However, these differences were not statistically significant. There was a significant difference in drop of hemoglobin between the two groups (24 g/L vs. 38 g/L, P = 0.04), with the decrease being larger among the women who had balloon tamponade. Patients undergoing balloon tamponade were more likely to have cell saver technologies used during their procedure (17% vs. 75%, P = 0.004), have longer operative times (129 minutes vs. 194 minutes, P = 0.003), and a longer duration of anaesthesia (171 minutes vs. 257 minutes, P = 0.0001). There were
no differences in admission to or length of stay in the intensive care unit, total length of postoperative stay, or associated maternal morbidities (disseminated intravascular coagulation, reoperation, urinary tract injury). There were no complications associated with balloon tamponade (e.g., gluteal necrosis, arterial thrombosis, or fistula) or maternal deaths in either group. Restricted analysis of the 16 women managed with emergency delivery is shown in Table 3. Women in this subgroup presented to the delivery suite at a median GA of 33+6 (range 31+2 to 35+2). Reasons for emergency delivery included antepartum hemorrhage, spontaneous onset of labour, and premature rupture of the membranes. There was a significant reduction in the composite outcome of total number of blood products transfused among women undergoing balloon tamponade (3.5 units vs. 15 units, P = 0.04). This appears to be largely driven by a reduction in the number of packed red blood cell units transfused (3.5 units vs. 9.5 units, P = 0.06). There were no significant differences in transfusion of fresh
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Table 3. Primary and secondary maternal outcomes among women delivered via emergency Caesarean hysterectomy who received and did not receive balloon tamponade for placenta accreta Maternal outcomesa
P value
No balloon tamponade (n = 10)
95% CI
Balloon tamponade (n = 6)
95% CI
Estimated blood loss, mL
3000 (2125 3500)
2000 to 3500
1950 (1500 2850)
1000 3000
0.12
Drop in hemoglobin, g/L
24 (¡1.8 to 26.2)
¡10 to 25.5
38 (19 40)
13 40
0.17
Use of cell saver, n
1 (10%)
0.5% 46%
3 (50%)
19% 81%
0.12
10 (100%)
66% 100%
5 (83%)
36% 99%
0.38
Total units transfused, n
15 (4.2 19.8)
3 20
3.5 (2.2 3.8)
1 11
0.04b
Packed red blood cell units transfused, n
9.5 (4.2 12)
3 12
3.5 (2.2 5.5)
1 6
0.06
Fresh frozen plasma units transfused, n
3 (0 4.8)
0 5
0 (0 1.5)
0 2
0.08
0 (0 1)
0 1.5
0 (0 0)
0 0.5
0.21
Required blood transfusion, n
Platelet units transfused, n Cryoprecipitate units transfused, n Massive transfusion, n Volume of fluid replacement, mL
0 (0 0.8)
0 2.5
0 (0 0)
0 0
0.18
5 (50%)
23% 85%
1 (17%)
0.9% 64%
0.31
5642 (4943 8313)
3600 8500
7215 (5150 8958)
4150 9000
0.27
Total operative time, min
136 (102 171)
88.5 172
156 (135 181)
88 188
0.12
Total anaesthetic time, min
175 (124 225)
111 234
220 (200 238)
196 258
0.01b
Disseminated intravascular coagulation, n
1 (10%)
0.5% 46%
2 (33%)
6% 76%
0.52
Intensive care unit admission, n
2 (20%)
4% 56%
0 (0%)
0% 48%
0.50
Length of intensive care unit admission, days
0 (0 0)
0 0.5
0 (0 0)
0 0
0.27
7 (5 8.8)
4 9
6 (5 8.5)
5 9
0.38
Re-operation required, n
1 (10%)
0.5% 46%
0 (0%)
0 48%
1.00
Urinary tract injury, n
3 (30%)
8% 65%
2 (33%)
6% 76%
1.00
0
—
0
—
1.00
Length of postoperative stay, days
Maternal death, n CI: confidence interval.
a Maternal outcomes presented as median (interquartile range) or numbers, proportions (%), and 95% CI. P value was calculated with Mann-Whitney test for continuous variables and with Fisher exact test for categorical variables CIs for medians were estimated by bootstrap. b
Significant value.
frozen plasma, platelets, or cryoprecipitate. Women undergoing balloon tamponade had a longer duration of anaesthesia (220 minutes vs. 175 minutes, P = 0.01). DISCUSSION
This study represents the largest Canadian cohort of women with placenta accreta managed with Caesarean hysterectomy and internal iliac artery balloon tamponade. Our study shows that the use of internal iliac artery balloons is associated with lower rates of estimated blood loss and lower blood transfusion requirements than in controls in our greater cohort. These differences were not statistically significant in our greater cohort, although a similar and statistically significant reduction in transfusion occurred among women with placenta accreta who were delivered on an emergency basis. Total operative and anaesthetic times were longer for women who underwent balloon tamponade, and there were no complications associated with the use of this technology.
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Despite the increasing incidence of placenta accreta syndromes, the optimal management strategy to reduce maternal morbidity has not been determined. Different approaches have been described in the literature, including conservative management with uterine preservation,3,10,11 and planned Caesarean hysterectomy with or without adjunctive procedures such as balloon tamponade or uterine artery embolization.2,9,12,13 Our study suggests that balloon tamponade is safe, and the reduced blood loss and transfusion requirements associated with the procedure indicate that it may be the preferred management strategy. The Royal Columbian Hospital in New Westminster, British Columbia, has become a specialized placenta accreta centre of excellence. Patients are managed by a multidisciplinary team because this strategy has consistently shown excellent patient outcomes.8,9 Internal iliac artery balloon tamponade before elective Caesarean hysterectomy has become our preferred management approach. On the basis of the placenta previa literature,14 patients with placenta accreta are scheduled for delivery at 36 weeks gestation in
Internal Iliac Artery Balloon Tamponade in Placenta Accreta
an effort to minimize both maternal and neonatal morbidity. In the operating room the interventional radiologist inserts bilateral internal iliac artery balloons, and the balloons are left deflated. Caesarean delivery is performed. After delivery of the fetus, the balloons are inflated, the placenta is left undisturbed, and immediate hysterectomy follows. Once hysterectomy is completed, the balloons are deflated, and hemostasis is confirmed. Iliac artery balloons are removed after abdominal closure. In 2006 an advanced, fluoroscopically enabled operating room was built, enabling insertion of iliac balloons with the patient in optimal position on the operating table. Of those women in our cohort who underwent balloon tamponade, 11 patients (92%) were managed exclusively in the fluoroscopically enabled operating room. To our knowledge, this is the only published cohort of women managed with balloon tamponade in the operating room, thus obviating the need for patient transfer and repositioning. Subsequent patient transfer may lead to balloon displacement and may have been responsible for the reported lack of benefit of balloon tamponade in previous studies.12,15,16 Community-based sites face unique challenges in how to manage an undiagnosed placenta accreta recognized only at the time of Caesarean delivery. Expert opinion favours performing a stabilizing procedure and transferring the patient to a higher level of care, should maternal and fetal status allow such a delay.2 Alternatively, a hysterotomy can be made well above the placenta, the placenta is left undisturbed, the uterus and abdomen are closed, and the patient is transferred to a higher level of care for expert consultation. In our study population estimated blood loss and blood transfusion were reduced in all patients undergoing balloon tamponade. However, these differences were statistically significant only when the study population was restricted to patients undergoing emergency Caesarean delivery. Confounding by indication (i.e., the higher severity of placenta accreta in the balloon tamponade group) (Figure) likely explains the lack of significance in the unrestricted study population. The relatively small study size, the increased use of cell saver technologies in the balloon-treated group, and the lower blood loss associated with elective Caesarean delivery are other potential explanations for the differences in findings between the overall study population and emergency cases.17 Although our study represents the largest Canadian cohort of women with placenta accreta managed with Caesarean hysterectomy and internal iliac artery balloon tamponade, the small sample size may introduce both type 1 and type 2 statistical errors. Conducting multiple
analyses on a small sample of data may increase the likelihood of type 1 error. Furthermore, the sample size may be too small to detect some biologically significant effects (type 2 error). Two previous studies of varying size (nine and 69 cases, respectively) evaluated balloon tamponade and failed to show reductions in estimated blood loss and blood transfusion.15,16 However, in both these studies patients were transported to the operating room after insertion of the iliac artery balloons, and this practice may have dislodged the balloon catheters. Two other studies reported significant reductions in estimated blood loss and blood transfusion following balloon tamponade for placenta accreta18,19; the first was a retrospective review of 25 cases,18 and the second was a prospective follow up of 163 cases.19 These studies were limited by the lack of histopathologic confirmation of the diagnosis of placenta accreta, with less than one half of the cases subjected to pathologic examination in the first study18 and only 6% in the second study.19 Sixty-seven percent (n = 16) of cases in our cohort were managed with emergency delivery. Because the majority of these women presented with unstable placenta previa-accreta they were at extremely high risk of hemorrhage. These women presented at a median GA of 33 +6 weeks. Planning elective delivery at 35 weeks, as opposed to the current practice of scheduled delivery at 36 weeks, would have prevented the emergency delivery of five additional cases. Such a change should be considered because it has the potential to further reduce maternal morbidity from placenta accreta. The strengths of our study include uniform pathologic diagnosis with routine hysterectomy in all cases, a high rate of antenatal diagnosis, management in a multidisciplinary centre with significant expertise in the diagnosis and management of placenta accreta, and placement of iliac artery balloons in the operating room, thereby obviating the need for patient transfer or repositioning. Study limitations include small size, a higher incidence of placenta percreta in the intervention group, and a high overall rate of emergency procedures. The latter limitation may necessitate a review of the optimal timing of planned delivery. Further research is required to evaluate the benefit of internal iliac artery balloon tamponade in the elective setting. CONCLUSION
Internal iliac artery balloon tamponade decreases blood transfusion requirements for patients following emergency
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Caesarean hysterectomy for placenta accreta. Insertion of internal iliac artery balloons in the operating room, which obviates the need for patient transfer and prevents potential displacement of the balloons, may be an important factor in ensuring efficacy of this procedure. Further studies are needed to clarify the benefit of balloon tamponade in the elective setting and to identify the optimal timing of scheduled delivery for women with placenta accreta.
7. Silver RM. Implications of the first cesarean: perinatal and future reproductive health and subsequent cesareans, placentation issues, uterine rupture risk, morbidity, and mortality. Semin Perinatol 2012;36:315–23. 8. Silver RM, Fox KA, Barton JR, et al. Center of excellence for placenta accreta. AM J Obstet Gynecol 2015;5:561–8. 9. Eller AG, Nennett MA, Sharshiner M, et al. Maternal morbidity in cases of placenta accreta managed by a multidisciplinary team compared with standard obstetric care. Obstet Gynecol 2011;117:331–7. 10. Amsalem H, Kingdom J, Farine D, et al. Planned cesarean hysterectomy versus “conserving” cesarean section in patients with placenta accreta. J Obstet Gynaecol Can 2011;33:1005–10.
Acknowledgements
This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. There are no conflicts of interest to declare. The views represented in this manuscript are of the authors own and do not represent the institutions in which the research was conducted. The authors would like to thank Arianne Albert from the Women’s Health Research Institute for her expertise in statistical analysis.
11. D’Souza DL, Kingdom JC, Amsalem H, et al. Conservative management of invasive placenta using combined prophylactic internal iliac artery balloon occlusion and immediate postoperative uterine artery embolization. Can Assoc Radiol J 2015;66:179–84. 12. Dilauro MD, Dason S, Athreya S. Prophylactic balloon occlusion of internal iliac arteries in women with placenta accreta: literature review and analysis. Clin Radiol 2012;67:515–20. 13. Angstman T, Gard G, Harrington T, et al. Surgical management of placenta accreta. Am J Obstet Gynecol 2010;202:38.e1–9. 14. Blackwell SC. Timing of delivery for women with stable placenta previa. Semin Perinatol 2011;35:249–51.
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