CASE 9132 Published on 26.03.2011

Post partum uterine rupture following caesarean section

Section

Genital (female) imaging

Case Type

Clinical Cases

Authors

Kaduthodil M, Elliot L, Prasad D
Department of Radiology, Bradford Teaching Hospitals, Bradford, U.K.

Patient

35 years, female

Categories
Area of Interest Genital / Reproductive system female ; Imaging Technique Ultrasound, CT
Clinical History
A 35-year-old lady, 6 days post lower segment caesarean section suddenly developed abdominal pain and shortness of breath. On examination she was tachycardic, tachypnoeic and pyrexial with abdominal distention and guarding.
Laboratory results showed haemoglobin 9 mg/dl, neutrophilic leucocytosis (16,000) and raised C-reactive protein (120mg/L).
Imaging Findings
CT scan of the abdomen and pelvis done within a few hours demonstrated fluid collection (10 HU) anterior to the uterus. A low attenuation tract was noted to extend from the endometrial cavity to the fluid collection, traversing the myometrium in the right anterior aspect of the lower uterus, at the level of the caesarean scar.

Small bowel and colon were unremarkable.

A CT urogram was also performed which excluded iatrogenic urinary bladder injury as a cause for the pelvic fluid collection.

Ultrasound scan done later that day showed a septated fluid collection in the anterior aspect of the lower uterine segment at the level of the caeserean scar. There was irregularity to the outline of the uterus with low echo tract in the uterine wall at this level further suggesting the presence of scar dehiscence.

Subsequently a laparatomy was performed which confirmed the caesarean section scar dehiscence.
Discussion
The terms uterine rupture and dehiscence has been interchangeably used by clinicians although some suggest that separation of all the uterine wall layers constitutes rupture whereas the serosa remains intact in dehiscence.

Uterine rupture remains a very rare complication of pregnancy and postpartum (0.05%) in spite of increasing incidence of cesarean sections [1]. Howerver it remains one of the most important causes (7%) of maternal mortality and around 20% of deaths from haemorrhage alone [2].

Uterine rupture is usually an acute presentation with haemodynamic instability and abdominal discomfort. However as in the reported case, symptoms can temporarily settle on fluid resuscitation and analgesia which can be falsely reassuring.

Direct clinical examination of uterine cavity may reveal the rupture but failure to see an obvious tear does not rule out the diagnosis especially in presence of haematoma and postpartum changes [3].

Also postpartum haemorrhage, pelvic infection and conditions like pulmonary embolism can have similar clinical presentation.

Hence early imaging is essential to make a prompt diagnosis and initiate appropriate treatment.

Ultrasound is the initial investigation of choice especially as it avoids ionising radiation in a young patient and can be performed at the bedside. Moreover, ultrasound provides excellent soft tissue resolution and the uterine wall integrity can be visualised in most cases. It can also demonstrate the indirect signs like fluid collection and haematoma. Patient compliance might be an issue if in a lot of pain.

CT scans has a high sensitivity in diagnosing uterine rupture. In addition to accurately demonstrating a pelvic collection, it may demonstrate the site of rupture as in this case. A low attenuation tract extending from the lower segment of the uterus (site of caesarean section) into a pelvic collection is highly suggestive of uterine dehiscence, in the appropriate clinical setting.

MR would delineate this abnormality better due to superior tissue contrast capability, but it is difficult to obtain an MR scan in the acute clinical setting and also the patient may not be able to comply with the longer examination times at MRI.

Uterine dehiscence needs to be excluded in a postpartum patient who presents with sepsis and haemodynamic instability. Awareness of this condition and recognition of the typical imaging findings are of paramount importance as this requires urgent surgical intervention.
Differential Diagnosis List
Post partum uterine wall dehiscence with pelvic abcess.
Post partum haemorrhage
Puerperal infection
Final Diagnosis
Post partum uterine wall dehiscence with pelvic abcess.
Case information
URL: https://www.eurorad.org/case/9132
DOI: 10.1594/EURORAD/CASE.9132
ISSN: 1563-4086