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					The British Journal of Radiology, 73 (2000), 1323±1325   E   2000 The British Institute of Radiology



Case report
Sacculation of the uterus and placenta accreta:
MRI appearances
D E DEFRIEND, FRCR, P A DUBBINS, FRCR and P M HUGHES, MRCP, FRCR
Department of Radiology, Derriford Hospital, Plymouth PL6 8DH, UK


    Abstract. A case of classic sacculation of the gravid uterus in association with placenta percreta is
    reported. The MRI appearances of these conditions are described. The role of MRI in de®ning
    anatomy and in permitting planned surgical management is discussed.



  Uterine sacculation and placenta accreta are               Discussion
rare complications of pregnancy. We report a
                                                                Uterine sacculation is a rare complication of
patient in whom both conditions occurred simul-
                                                             pregnancy. The condition has been de®ned as a
taneously and describe the MRI appearances.
                                                             transitory pouch or sac-like structure developing
Both conditions are dif®cult to detect antenatally
                                                             from a portion of the gravid uterus and contain-
and cause substantial intrapartum and post-
                                                             ing all layers of the uterus [1]. Possible causes of
partum morbidity.
                                                             uterine sacculation include a primary myometrial
                                                             defect, previous surgery or excessive enzymic
                                                             digestion during implantation of the trophoblast
Case report                                                  [2±4]. The classic form of sacculation as described
                                                             in the present case is thought to result from an
   A 33-year-old Gravida 3 Para 2 presented at 32
                                                             incarcerated retroverted uterus, in which the
weeks of pregnancy with abdominal pain and
                                                             anterior wall hypertrophies as the fetus enlarges
dif®culty in passing urine. She had undergone a
                                                             and the posterior wall forms a sacculation
Caesarean section in her ®rst pregnancy and a
                                                             containing a fetal pole [5±8].
ventouse-assisted delivery in her second. On
                                                                1 in 3000 pregnancies is reported to have
examination, the fetal lie was longitudinal and
                                                             gestational retroversion with incarceration [9].
presentation was cephalic. The cervix could not be
                                                             Symptoms include non-speci®c abdominal pain,
located on vaginal examination and the possibility
                                                             vaginal bleeding, and urinary and bowel symp-
of a uterine sacculation was raised. Ultrasound
                                                             toms [10, 11]. Treatment usually requires manual
showed a probable posterior sacculation of the
uterus displacing the vagina anteriorly, impairing           reduction during the second trimester [6];
visualization of the cervix and limiting views of            Caesarean section is the treatment of choice at
the fetal head. A previous routine ultrasound scan           term [12]. Only about 12 cases of classic saccula-
had not shown any abnormality. On MRI,                       tion or uterine incarceration occurring during the
sagittal T2 weighted spin echo images (Figure 1)             third trimester have been reported [10].
demonstrated a posterior sacculation of the uterus              Previous studies have reported cases exhibiting
with the fetal head in the pouch of Douglas. The             both sacculation and placenta accreta [13, 14], a
lower anterior uterine wall appeared multilayered            placental disorder in which placental villi attach
as a result of the posterior sacculation. In                 directly to the myometrium without intervening
addition, there was placenta percreta superiorly             decidua. In its most severe form, placenta
(Figure 2). A healthy female child was delivered             percreta, the placenta invades through the myo-
by Caesarean section. Operative ®ndings con-                 metrium and may involve adjacent pelvic organs
®rmed the uterine sacculation and showed pla-                [15]. In some cases the placental abnormality
centa percreta at the site of the previous anterior          appears to cause a localized weakness, which
lower segment uterine scar. Total abdominal                  results in sacculation [14]. In the present case, the
hysterectomy was performed because of the                    placenta percreta was most likely owing to a
placenta percreta, which was con®rmed histo-                 combination of the thinned anterior uterine wall
logically.                                                   and the previous Caesarean section.
                                                                Both uterine sacculation and placenta accreta
Received 25 August 2000 and in revised form 31 August        are dif®cult to diagnose. The ultrasound appear-
2000, accepted 25 September 2000.                            ances of placenta accreta have been described [15].

The British Journal of Radiology, December 2000                                                              1323
                                                                  D E DeFriend, P A Dubbins and P M Hughes




Figure 1. Sagittal T2 weighted spin echo image of the
                                                          Figure 2. Sagittal T2 weighted spin echo image show-
lower abdomen and pelvis demonstrating a gravid
                                                          ing the placenta percreta, which has extended through
uterus. There is a posterior sacculation of the uterus
                                                          the myometrium superiorly (arrowhead).
containing the fetal head, which is incarcerated in the
pouch of Douglas. The low anterior uterine wall is        capabilities and no apparent adverse effects on the
effectively multilayered owing to the sacculation
(arrows).                                                 fetus [23]. While MRI is only likely to be used
                                                          where other imaging is inconclusive, this case
Use of MRI to suggest or con®rm a diagnosis of            demonstrates the use of MRI in diagnosing
placenta percreta has been described, but usually         uterine sacculation and placenta percreta that
only in cases with bladder wall invasion [16±19].         could not be fully evaluated by ultrasound.
The present case illustrates that MRI can also
successfully identify placenta percreta, even when
there is no involvement of adjacent organs.               References
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1324                                                           The British Journal of Radiology, December 2000
Case report: Uterine sacculation and placenta accreta

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The British Journal of Radiology, December 2000                                                           1325

				
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