








































Key Words Competing Interests Article Information

 Placenta accreta spectrum, placenta 
percreta, placenta accreta, placenta increta, 
multidisciplinary management

None declared. Received on August 6, 2021 
Accepted on September 7, 2021 
This article has been peer reviewed.

Soc Int Urol J. 2022;3(1):28–32

DOI: 10.48083/OLRA4694

28 SIUJ  •  Volume 3, Number 1  •  January 2022 SIUJ.ORG

This is an open access article under the terms of a license that permits non-commercial use, provided the original work is properly cited.  
© 2022 The Authors. Société Internationale d'Urologie Journal, published by the Société Internationale d'Urologie, Canada.

ORIGINAL RESEARCH

Urological Involvement in the Multidisciplinary 
Management of Placenta Accreta Spectrum  
in a Centralised, High-Volume Centre:  
A Retrospective Analysis
Brian D. Kelly,1,2 Rebecca Moorhead,1,3 David Wetherell,1 Tracey Gilchrist,3 Marcalain Furrer,1  
Marlon Perera,4 Briony Norris,1 David Wrede,3,4 Mark Umstad,3,4 Jamie Kearsley,1 Faris Al-Shammaa3,5

1 Department of Urology, The Royal Melbourne Hospital, Melbourne, Australia 2 Department of Surgery, Peter MacCallum Cancer Centre, University of Melbourne, 
Melbourne, Australia 3 Department of Obstetrics and Gynaecology, The Royal Women's Hospital, Melbourne, Australia 4 Department of Surgery, University of Melbourne, 
Melbourne, Australia 5 Department of Obstetrics and Gynaecology, The University of Melbourne, Melbourne, Australia

Abstract

Objectives Placenta accreta spectrum (PAS) significantly increases the complexity of childbirth and frequently 
involves urologic organs. Multidisciplinary team (MDT) care is paramount to ensure optimal outcomes. We aimed to 
evaluate urologic interventions in patients with PAS at a centralised, tertiary referral centre.

Methods An analysis of a prospectively collected data set, consisting of all women presenting with PAS at our 
institution between November 2013 and June 2019. Patients who required urological intervention were identified, and 
perioperative details were retrieved.

Results Forty-two cases of PAS were identified. The mean maternal age was 35 years, and mean gestational age 
at delivery was 34 weeks. Thirty-seven cases were managed electively, with 5 cases managed conservatively (no 
hysterectomy) and 5 requiring emergency management. Fifteen patients (36%) had suspected bladder invasion on 
MRI. A total of 36 patients (86%) had ureteric catheters inserted, 14 (33%) required bladder repair, and 2 had ureteric 
injuries (5%).

Conclusions  PAS frequently requires urological intervention to prevent and repair injury to the urinary bladder 
and ureter. PAS is a rare condition that is best managed in an MDT setting in a centralised, tertiary, high-volume 
centre with access to a variety of medical and surgical sub-specialities.

Introduction

Placenta accreta spectrum (PAS) describes the range of pathologic adherence of the placenta: accreta, in which 
placental villi encroach on the decidual layer; increta, in which the myometrium is invaded; and percreta, in which 
the myometrium is fully penetrated by placental villi, breaching the serosa and invading adjacent organs including 
the bladder (most common), broad ligament, or sigmoid colon[1,2]. These disorders confer substantial risk for foetal 
and maternal death, with maternal mortality rates of up to 7%[3]. The overall incidence ranges from 1 in 435 to 1 in 
5882 deliveries[4]. Placenta previa and increasing number of prior Caesarean section deliveries are independent risk 
factors for abnormally adherent placenta[5]. Other risk factors include advancing maternal age, in vitro fertilisation 
and other assisted reproductive technologies, previous operative uterine procedures, and previous PAS[4].

http://SIUJ.org
mailto:marlonLperera%40gmail.com?subject=SIUJ


Major maternal morbidity is due to the risk of 
massive maternal haemorrhage, subsequent major 
transfusions, and associated sequelae such as peripar-
tum hysterectomy, ICU admission, cystotomy, infec-
tions, multi-organ failure, and even death[6,7]. Three 
main approaches to delivery have been described in 
women with PAS, all involving Caesarean section. 
These include Caesarean hysterectomy, the extirpative 
approach (in which the adherent placenta is removed 
post-delivery), and conservative management. Conser-
vative management (when preservation of fertility is 
desired) involves delivery by Caesarean section without 
hysterectomy, with the placenta or part of it left in situ. 
Specific concerns with this approach include massive 
secondary postpartum haemorrhage and sepsis. The 
extirpative approach is widely criticised because of the 
significant rate of increased maternal morbidity and 
massive postpartum haemorrhage[6,8]. Scheduled 
Caesarean hysterectomy and avoidance of placental 
removal is associated with reduced maternal morbidity 
and is the preferred management[6]. Placenta percreta is 
the leading cause of peripartum hysterectomy in West-
ern countries[2].

Urologist intervention is not uncommon in the 
management of PAS[9,10]. The rate of urinary tract 
injury during Caesarean hysterectomy for PAS is 29% 
compared with 4.8% in standard hysterectomy[11]. This 
risk plus the potential of bladder invasion requires ante-
natal diagnosis for prevention of injury (via ultrasound, 
magnetic resonance imaging and/or cystoscopy) and 
cohesive multidisciplinary team (MDT) involvement 
throughout the entire pregnancy[12,13]. In 2016, we 
published a retrospective analysis of women present-
ing with PAS to a major tertiary centre, showing the 
need for urological intervention in these patients[9]. 
We have prospectively maintained a database of cases 
to strengthen the case for multidisciplinary involve-
ment. We aimed to evaluate urological interventions in 
patients with placenta accreta spectrum at a centralised, 
tertiary referral centre.

Materials and Methods
Forty-two women who presented to The Royal Women’s 
Hospital (RWH) with PAS between November 2013 and 
June 2019 were identified. A retrospective analysis of 
the prospectively collected data was undertaken using 
perioperative details. Further data pertaining to imaging 
and pathology results were retrieved retrospectively 
from the medical records of patients. All data were 
collected with permission granted by The Human 
Research and Ethics Committees at The Royal Women’s 
Hospital (Project AQA 20/18).

The management of PAS is centralised to The RWH 
in Melbourne, with smaller peripheral hospitals in the 

City of Melbourne and surrounding areas in the State 
of Victoria referring patients to this service. The MDT 
consists of obstetricians, specialised nursing staff, 
gynaecological surgical oncologists, urologists, general 
surgeons, paediatricians, diagnostic radiologists, 
and interventional radiologists. When a patient with 
suspected PAS is referred, Doppler-enhanced ultrasound 
is repeated in the RWH radiology department and, if 
necessary, an MRI of the pelvis is performed to further 
characterise the PAS. The case is then discussed at a PAS 
MDT and a date decided to perform surgery and a deter-
mination made whether hysterectomy or conservative 
management (no hysterectomy) will be attempted. All 
team members are also aware of the case in the event 
of emergency admission and subsequent emergency 
surgery.

Urological involvement primarily consisted of rigid 
cystoscopy for assessment of bladder involvement of 
the placenta and placement of ureteric catheters before 
Caesarean section. Experienced urologists scrubbed 
in with the gynaecologist during hysterectomy and 
performed cystotomy and repair when necessary. 
For more advanced cases, interventional radiologists 
inserted internal iliac artery occlusion balloons, and an 
intraoperative cell salvage machine was available in the 
event of catastrophic haemorrhage. All patients were 
managed in intensive care postoperatively.

Results
Between November 2013 and June 2019, a total of 42 
patients presented with an antenatally suspected PAS. 
Patient characteristics are shown in Table 1. The mean 
maternal age was 35 (SD 4.9). Within this cohort, the 
mean number of prior Caesarean section deliveries was 
2, and mean gestational age at delivery 34 weeks. For 
39 patients, intended treatment was primarily planned 
admission for elective Caesarean hysterectomy; for 3 
patients, it was planned conservative management (no 
hysterectomy). Elective operations eventuated in 37 
patients, with 5 requiring emergency management.

Urologists performed cystoscopy and placement of 
bilateral ureteric catheters in 36 patients (86%); fluo-
roscopy was not used. Bladder wall involvement was 
suspected on preoperative imaging (placental MRI) in 15 
cases (35%). However, only 7 patients were found to have 
bladder invasion intraoperatively. In another 7 cases, 
inadvertent iatrogenic cystotomies were performed with 
no imaging to suggest bladder involvement. Placen-
tal invasion of the bladder requiring cystotomy and 
repair by the urology team intraoperatively was found 
at Caesarean hysterectomy in 14 cases (33%). There were 
2 cases of ureteric injury. One case had ureteric cathe-
ters in situ and the other was an emergency case where 
ureteric catheters were not placed. Both ureteric injuries 

29SIUJ.ORG SIUJ  •  Volume 3, Number 1  •  January 2022

Urological Involvement in the Multidisciplinary Management of Placenta Accreta Spectrum in a Centralised, High-Volume Centre

http://SIUJ.org


were recognised intraoperatively, and the ureters were 
re-implanted. Five emergency cases did not have ureteric 
catheters inserted in the interests of time and patient 
safety. There was 1 case of a small suspected placenta 
accreta in which ureteric catheters were not inserted as 
advised by the MDT.

Average blood loss across all cases was 3025 mL, 
ranging from 700 mL to 17 litres. On further analysis, 
those who underwent elective procedure had an aver-
age loss of 2541 mL whereas those requiring emergency 

management had and mean loss of 6600 mL. There were 
8 cases of placenta percreta in which balloon catheters 
were inserted into the internal iliac arteries. There was 
no maternal mortality. One case of foetal death in utero 
occurred when the mother suffered major blood loss per 
vaginam requiring Caesarean hysterectomy at 19 weeks’ 
gestation.

Discussion
Patients within our own institution are identified and 
their cases brought forward for discussion at our PAS 
MDT. Other institutions within the City of Melbourne 
or the State of Victoria also refer patients to our MDT 
for further management. The MDT meetings are 
arranged with an obstetrician, a radiologist, a urologist, 
and a g y naecologic surgica l oncologist present. 
Other members of the extended MDT team include 
representatives from the haematology department to 
ensure plans are in place for catastrophic haemorrhage, 
as well as members of the general surgery, vascular 
surger y, and neonatolog y teams. An anaesthetic 
team with significant obstetric and complex surgical 
experience with massive haemorrhage is required. The 
appropriate surgical expertise is paramount for these 
complex cases[13].

Intraoperative cell salvage is not always required 
but is set up in the operating theatre for all cases. The 
first intraoperative role of the urology team is to assess 
the urothelium of the bladder and then the placement 
of ureteric catheters. The urology team will remain in 
theatre during the Caesarean section and hysterectomy 
to reduce the risk of bladder or ureteric injury and for 
reconstruction as required. The placement of ureteric 
catheters reduces the risk of ureteric injury but also 
allows for the earlier identification of injury[14,15]. Most 
patients in our series received preoperative ureteral cath-
eterisation with resulting low risk of ureteric injury.

The accurate diagnosis of PAS is imperative for the 
management planning of these cases. All suspected cases 
in our institution have repeat imaging in our radiology 
department with Doppler-enhanced ultrasound and 
MRI. There is evidence to suggest that there is less severe 
haemorrhage when PAS is correctly identified antena-
tally rather than as an incidental finding at the time of 
elective or emergency delivery[6,16]. The reported sensi-
tivity of MRI for the diagnosis of PAS is 80% to 85% and 
the specificity is 65% to 100%[17]. Interestingly, MRI 
does not necessarily improve upon the accuracy of ultra-
sound imaging[18]. In our series, the MRI had suggested 
7 cases of bladder involvement but had not identified 7 
others that were recognised intraoperatively. However, 
as these cases are managed in a high-volume unit, a urol-
ogist was present in the operating theatre for all cases, as 
per our MDT protocol.

30 SIUJ  •  Volume 3, Number 1  •  January 2022 SIUJ.ORG

 ORIGINAL RESEARCH

TABLE 1. 

Patient characteristics and perioperative data 

Number of 
patients
N = 42

Preoperative Characteristics

Mean (SD) age, years 35 (4.9)

Mean (SD) previous Caesarean sections 2 (1.1)

Preoperative bladder involvement on imaging 15 (35%)

Mean gestational age (SD) at delivery, weeks 34 (3.4)

Planned Caesarean hysterectomy 39 (93%)

Planned conservative 3 (7%)

Perioperative Data

Mean (SD) blood loss, mL 3025 (3147)

Ureteric catheter/stent placement 36 (86%)

Elective surgery 37 (88%)

Emergency surgery 5 (12%)

Bladder invasions with repair 14 (33%)

Ureteric injury with ureteric reimplantation 2 (5%)

Postoperative Diagnosis

Percreta 29 (70%)

Increta 8 (19%)

Accreta 4 (9%)

Non-PAS 1* (2%)

*  Antenatal suspected mild accreta on imaging, no evidence found 
intra operatively or on formal histology

http://SIUJ.org


One case in our series was identified as a placenta 
accreta on the basis of ultrasound imaging and MRI. At 
the time of surgery, it was found to not be a case of PAS, 
but this potential high-risk case was managed appropri-
ately as per our MDT protocol.

We had 8 cases of placenta percreta in which inter-
ventional radiologists inserted balloon catheters into 
the internal iliac arteries. Upon delivery of the neonate, 
the balloons were inflated to reduce blood loss. Many 
high-volume centres also perform this procedure for 
selected placenta percreta cases, but it is not without 
risks. There is evidence that it can result in tissue infarc-
tion, infection, and elevated temperature postopera-
tively. A recent randomised controlled trial identified 
that balloon catheter occlusion of the internal iliac artery 
was not cost-effective, had significantly higher rates of 
postoperative fever, and made no significant difference 
in the rates of blood transfusion[19–21].

The neonatal paediatric team are also an integral part 
of the MDT. They are present in theatre at the time of 
delivery. Some series have advocated delivery at 34 to 
35 weeks’ gestation[12,22]. In our series the mean gesta-
tional age was 34 weeks. PAS may not have an adverse 
effect on neonatal outcomes, but given that the neonates 
are in general born pre-term, early involvement of the 
neonatal team will maintain high standards of care[23].

All patients in our series were admitted postoper-
atively to the ICU at The Royal Melbourne Hospital 
(RMH), an adjoining building. The RWH does not have 
an ICU, and the RMH has access to 24 hour on-call 
interventional radiology, general surgery, vascular 
surgery, and urology. If patients require embolization or 
a return to theatre, it is more practical for these patients 
to be managed at the RMH for the initial postoperative 
period. Liaising with the haematology department is 
also undertaken early; in our series, the mean blood loss 
was 3025 mL but the maximum blood loss recorded was 
17 litres. The mean was higher for emergency cases at 
6600 mL. Given the risk of having to instigate a massive 
transfusion protocol, it is imperative that the haematol-

ogy department is fully aware in advance of the planned 
elective cases, and in the event of its proceeding as an 
emergency.

Other high-volume series have discussed the impor-
tance of multidisciplinary planning in all aspects of 
the journey from diagnosis of PAS, intraoperative 
management and postoperative care[12,13,24,25].  
In our current series of 42 PAS cases there were 36 
(86%) that required ureteric catheter insertion and 
14 (33%) that required bladder repair, and there were 
2 ureteric injuries (5%) managed with a tension-free 
ref luxing ureteric reimplantation. The rate of blad-
der repair is similar to that in our series of 49 cases 
published in 2016, but there are fewer ureteric injuries 
in our current series.

Limitations of this work include the nature of a retro-
spective review of a prospectively maintained database. 
Despite this, meaningful conclusions may be drawn 
from the current data. While rare, PAS can have cata-
strophic outcomes for both the mother and the foetus. 
We highlight the acceptable outcomes of a centralised 
multidisciplinary service.

Conclusions
The evolution of the MDT management of these 
complex cases is paramount to maintain high standards 
and outcomes. These rare conditions are best managed 
in an MDT setting in a centralised, tertiary high-
volume centre with access to a variety of medical sub-
specialities.

Acknowledgements
We would like to acknowledge the department of 
obstetrics and gynaecology, radiology, haematology, 
and paediatrics at The Royal Women’s Hospital and the 
Department of Urology, The Royal Melbourne Hospital. 
M.P. is sponsored by the Australian-America Fulbright 
Commission administered through a 2021–2022 
Fulbright Future Scholarship funded by The Kinghorn 
Foundation.

31SIUJ.ORG SIUJ  •  Volume 3, Number 1  •  January 2022

Urological Involvement in the Multidisciplinary Management of Placenta Accreta Spectrum in a Centralised, High-Volume Centre

http://SIUJ.org


References

1. Wortman AC, Alexander JM. Placenta accreta, increta, and percreta. 
Obstet Gynecol Clin North Am.2013. ar;40(1):137–154. doi: 10.1016/j.
ogc.2012.12.002

2. Marcellin L, Delorme P, Bonnet MP, Grange G, Kayem G, Tsatsaris 
V, et al. Placenta percreta is associated with more frequent severe 
maternal morbidity than placenta accreta. Am J Obstet Gynecol.2018 
Aug;219(2):193.e1-193.e9. doi:10.1016/j.ajog.2018.04.049

3. O’Brien JM, Bar ton JR, Donaldson ES. The management of 
placenta percreta: onser vative and operative strategies. Am 
J Obstet Gyneco l.19 9 6 Dec;175 (6):16 32–16 3 8. doi:10.1016/
S0002-9378(96)70117-5

4. Carusi DA. The placenta accreta spectrum: epidemiology and risk 
factors. Clin Obstet Gynecol.2018 Dec;61(4):733–742. doi:10.1097/
GRF.0000000000000391

5. Bowman ZS, Eller AG, Bardsley TR, Greene T, Varner MW, Silver RM. 
Risk factors for placenta accreta: A large prospective cohort. Am J 
Perinatol.2014 Oct;31(9):799–804. doi:10.1055/s-0033-1361833

6. Eller AG, Porter T T, Soisson P, Silver RM. Optimal management 
strategies for placenta accreta. BJOG.2009 Apr;116(5):648–654. 
doi:10.1111/j.1471-0528.2008.02037.x

7. Eller AG, Bennett MA, Sharshiner M, Masheter C, Soisson AP, Dodson 
M, et al. Maternal morbidity in cases of placenta accreta managed 
by a multidisciplinary care team compared with standard obstetric 
care. Obstet Gynecol.2011 Feb;117(2 Pt 1):331–337. doi:10.1097/
AOG.0b013e3182051db2

8. Garmi G, Salim R. Epidemiology, etiology, diagnosis, and management 
of placenta accreta. Obstet Gynecol Int.2012. Article ID 873929.  
doi:10.1155/2012/873929

9. Norris BL, Everaerts W, Posma E, Murphy DG, Umstad MP, Costello AJ, 
et al. The urologist’s role in multidisciplinary management of placenta 
percreta. BJU Int.2016 Jun;117(6):961–965.doi:10.1111/bju.13332

10. Ng MK, Jack GS, Bolton DM, Lawrentschuk N. Placenta percreta with 
urinary tract involvement: the case for a multidisciplinary approach. 
Urology.2009 Oct;74(4):778–782. doi:10.1016/j.urology.2009.01.071

11. Vakili B, Chesson RR, Kyle BL, Abbas S, Echols KT, Gist R, et al. The 
incidence of urinary tract injury during hysterectomy: A prospective 
analysis based on universal cystoscopy. Am J Obstet Gynecol.2005 
May;192(5):1599–1604. doi:10.1016/j.ajog.2004.11.016

12. Shamshirsaz AA, Fox KA, Erfani H, Belfort MA. The role of centers 
of excellence with multidisciplinary teams in the management of 
abnormal invasive placenta. Clin Obstet Gynecol.2018 Dec;61(4):841–
850. doi:10.1097/GRF.0000000000000393

13. Shamshirsaz A A, Fox K A, Erfani H, Clark SL, Salmanian B, Baker 
BW, et al. Multidisciplinary team learning in the management of 
the morbidly adherent placenta: outcome improvements over time. 
Am J Obstet Gynecol.2017 Jun;216(6):612.e1–612.e5. doi:10.1016/j.
ajog.2017.02.016

14. Tam Tam KB, Dozier J, Martin JN Jr. Approaches to reduce urinary 
tract injury during management of placenta accreta, increta, and 
percreta: a systematic review. J Matern Fetal Neonatal Med.2012 
Apr;25(4):329–334. doi:10.3109/14767058.2011.576720

15. Merritt AJ, Crosbie EJ, Charova J, Achiampong J, Zommere I, 
Winter-Roach B, et al. Prophylactic pre-operative bilateral ureteric 
catheters for major gynaecological surgery. Arch Gynecol Obstet.2013 
Nov;288(5):1061–1066. doi:10.1007/s00404-013-2853-5

16. Warshak CR, Ramos GA, Eskander R, Benirskche K, Saenz CC, Kelly 
TF, et al. Effect of predelivery diagnosis in 99 consecutive cases of 
placenta accreta. Obstet Gynecol.2010 Jan;115(1):65–69. doi:10.1097/
AOG.0b013e3181c4f12a

17. Gielchinsky Y, Mankuta D, Rojansky N, Laufer N, Gielchinsky I, 
Ezra Y. Perinatal outcome of pregnancies complicated by placenta 
accreta. Obstet Gynecol.2004 Sep;104(3):527–530. doi:10.1097/01.
AOG.0000136084.92846.95

18. Berkley EM, Abuhamad AZ. Prenatal diagnosis of placenta accreta: 
is sonography all we need? J Ultrasound Med.2013 Aug;32(8):1345–
1350. doi:10.7863/ultra.32.8.1345

19. Ballas J, Hull AD, Saenz C, Warshak CR, Roberts AC, Resnik RR, et al. 
Preoperative intravascular balloon catheters and surgical outcomes in 
pregnancies complicated by placenta accreta: a management paradox. 
Am J Obstet Gynecol.2012 Sep;207(3):216.e1–5. doi:10.1016/j.
ajog.2012.06.007

20. Bishop S, Butler K, Monaghan S, Chan K, Murphy G, Edozien L. Multiple 
complications following the use of prophylactic internal iliac artery 
balloon catheterisation in a patient with placenta percreta. Int J Obstet 
Anesth.2011 Jan;20(1):70–73. doi:10.1016/j.ijoa.2010.09.012

21. Yu SCH, Cheng YKY, Tse WT, Sahota DS, Chung MY, Wong SSM, et al. 
Perioperative prophylactic internal iliac artery balloon occlusion in the 
prevention of postpartum hemorrhage in placenta previa: a randomized 
controlled trial. Am J Obstet Gynecol.2020 Jul;223(1):117.e1–117.e13. 
doi:10.1016/j.ajog.2020.01.024

22. Robinson BK, Grobman WA. Effectiveness of timing strategies 
for deliver y of individuals with placenta previa and accreta. 
O b stet Gy n e c o l . 2 0 10 O c t ;116 ( 4 ) : 8 3 5 – 8 4 2 . d oi:10 .10 9 7/
AOG.0b013e3181f3588d

23. Balayla J, Bondarenko HD. Placenta accreta and the risk of adverse 
maternal and neonatal outcomes. J Perinat Med. 2013 Mar;41(2):141–
149. doi: 10.1515/jpm-2012-0219

24. Silver RM, Fox KA, Barton JR, Abuhamad AZ, Simhan H, Huls CK, et al. 
Center of excellence for placenta accreta. Am J Obstet Gynecol.2015 
May;212(5):561–568. doi:10.1016/j.ajog.2014.11.018

25. Al-Khan A, Gupta V, Illsley NP, Mannion C, Koenig C, Bogomol A, et 
al. Maternal and fetal outcomes in placenta accreta after institution 
of team-managed care. Reprod Sci.2014 Jun;21(6):761–771. 
doi:10.1177/1933719113512528

32 SIUJ  •  Volume 3, Number 1  •  January 2022 SIUJ.ORG

 ORIGINAL RESEARCH

http://SIUJ.org

