Apport du scanner multi-détecteurs dans la prise en charge des volvulus du sigmoïde

Relationship Between Sigmoid Volvulus Subtypes, Clinical Course, and Imaging Findings

Background: Recent studies indicate that the organo-axial subtype of a sigmoid volvulus is more prevalent than the conventional mesentero-axial subtype. Our study aimed to assess the clinical and radiological findings that differentiate between these two subtypes, as well as to ascertain treatment outcomes and prognostic characteristics. Methods: A retrospective review included 54 patients, during which abdominal plain radiographs and computed tomography images were analyzed by two radiologists, and data on recurrence, mortality, and treatment outcomes were documented. Results: The mesentero-axial subtype comprised 40 cases (74%). No distinct radiographic findings were observed to differentiate between the two groups. In computed tomography, the sole significant parameter for differentiation was the number of transition zones. The diameter of the segment exhibiting a volvulus was greater in instances of the mesentero-axial subtype. The endoscopic detorsion treatment proved ineffective in five patients within the mesentero-axial sigmoid volvulus cohort. Conclusions: Identifying these two types of SV on CT images is essential because of their distinct prognoses and therapeutic results.

Sigmoid volvulus-Can CT features predict outcomes and recurrence?

OBJECTIVES

Sigmoid volvulus (SV) is a common cause of bowel obstruction, especially in older patients. SV can be mesenteroaxial (M-SV) or organoaxial (O-SV). The purpose of this study was to assess if CT findings in SV are associated with clinical outcomes. including recurrence, choice of management, and mortality.

MATERIALS AND METHODS

This study includes patients with SV and a CT within 24 hours of presentation. CT features, including mesenteraoxial/organoaxial arrangement, direction of rotation, transition points, distension, whirl-sign, ischemia, and perforation were determined. Demographics, treatment, recurrence, and outcome data were recorded.

RESULTS

One hundred and seventeen cases were diagnosed in 80 patients (54 male). The mean age was 70 years (± 17.1). M-SV and O-SV were equally prevalent (n = 39 vs. n = 41, respectively). M-SV was significantly more common with anticlockwise rotation in the axial plane (p = 0.028) and clockwise rotation in the coronal plane (p = 0.015). All patients with imaging features of ischemia underwent surgery (n = 6). There was no significant difference in outcome variables (30-day mortality, 30-day readmission, recurrence) between the O-SV and M-SV groups. The degree of bowel distension on initial presentation was a significant predictor of recurrence, with ≥ 9 cm vs < 9 cm associated with an increased odds of any recurrence (OR: 3.23; 95%CI: 1.39-7.92).

CONCLUSION

In SV, sigmoid distension of more than 9 cm at baseline CT was associated with an increased risk of recurrence. Imaging features of ischemia predicted surgical over endoscopic intervention. Organoaxial and mesenteroaxial SV had similar prevalence, but the type of volvulus was not associated with clinical outcomes or choice of management.

CLINICAL RELEVANCE STATEMENT

There is a risk of recurrent sigmoid volvulus with colonic distension greater than 9 cm. This work, comparing volvulus subtypes, shows that this finding at the initial presentation could expedite consideration for surgical management.

KEY POINTS

Reports of outcomes for different subtypes and rotational directions of volvuli have been contradictory. No difference in measured outcomes was found between subtypes; distension ≥ 9 cm predicted recurrence. CT features can aide management of sigmoid volvulus and can prompt surgical intervention.

A tale of two twists: mesentero-axial and organo-axial sigmoid volvulus

INTRODUCTION

Sigmoid volvulus is a potentially devastating and life-threatening condition associated with sigmoid colon redundancy. Many of the classical radiological signs are considered to represent the two adjacent loops of bowel in a mesentero-axial volvulus. However, limited case reports and series have reported on an organo-axial subtype of sigmoid volvulus. This clinical entity is not widely understood. In this study, we assess the radiological and clinical features of mesentero-axial and organo-axial sigmoid volvulus.

METHODS

After institutional board approval (CH62/6/2016-228), all computed tomography (CT) studies from 2011 to 2017 reported as sigmoid volvulus at a single institution were reviewed. The cases were reviewed by three radiologists retrospectively and the course of the bowel followed with a focus on assessing its rotational axis. In each case, the sigmoid volvulus was independently subclassified as mesentero-axial or organo-axial volvulus based on the axis of rotation of the volvulus. In addition, X-ray signs including disproportionate sigmoid dilatation, distended inverted 'U' in sigmoid, coffee bean sign, opposed wall sign, direction of apex of sigmoid loop, liver overlap sign, northern exposure sign and proximal colonic dilatation and CT features including whirl sign, 'X' marks the spot sign, split wall sign and number of transition points were reported for each case. The clinical management and outcomes including morbidity, mortality, endoscopic decompression and need for surgery were also evaluated. The subtype of volvulus was correlated with the above X-ray signs, CT features and clinical management and outcomes. Statistical analysis was conducted using Stata/MP, version 15 (StataCorp LP, College Station, TX, USA).

RESULTS

A total of 38 scans were reviewed. There were 19 patients identified. Of these, six (32%) were reported as mesentero-axial and 13 (68%) as organo-axial volvulus. No X-ray signs were able to distinguish the two types of volvulus. The number of transition points on CT was predictive of volvulus subtype (OR 25, 95% CI: 1.30-1295.30, P = 0.01). Within the limitations of a small cohort, there was no statistically significant difference in unsuccessful endoscopic decompression, need for colectomy, repeated admissions or mortality between the groups.

CONCLUSION

This study has demonstrated that organo-axial sigmoid volvulus may be as common as mesentero-axial volvulus. Distinguishing organo-axial from mesentero-axial volvulus can be achieved on CT, but not on abdominal X-ray. The number of transition points (two for mesentero-axial and one for organo-axial) may be used as a diagnostic feature for differentiating the two forms of volvulus.

The steel pan sign of sigmoid volvulus-A case series

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The CT scan finding of sigmoid volvulus is closely resembles to the percussion instrument known as “steel pan”.

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This Steel pan sign has not yet been described in the literature for sigmoid volvulus.

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The sign is easier to recognize on CT scan of the abdomen and in some cases on plain abdominal X- rays.

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This easily recognized symbol enables faster diagnosis and earlier treatment of this disease, thus reducing the morbidity and mortality.

Introduction

Signs in radiology are usually based on many common objects or patterns that are easily recognizable in everyday life. The objective behind this association is to aid in the understanding and diagnosis of the disease process. These signs can be seen in different imaging modalities such as plain radiograph and computed tomography.

Presentation of case

4 consecutive cases of sigmoid volvulus presented at our tertiary hospital between January 2016 and June 2017. 2 of these cases were managed surgically and others were managed conservatively. The CT scan and abdominal radiographs in these patients were reviewed with consultant radiologist, which bear resemblance to the percussion instrument known as the steel pan.

Discussion

The literature has described few radiological signs of sigmoid volvulus in the past. In the following case series, we would like to introduce the “Steel pan Sign”, a novel radiological pattern which bears a close resemblance to the percussion instrument known as the steel pan. The Steel pan sign is easier to recognize on CT scan of the abdomen. However, in some cases it can be seen on plain X-Rays.

Conclusion

The appearance of sigmoid volvulus on CT scans as well as on plain abdominal X-rays bears a significant resemblance to the pattern observed on the face of the Trinidadian steel pan, the recognition of which can aid in the diagnosis of this disease.

Organo-axial volvulus of the small intestine: radiological case report and consideration for its mechanism

Gastrointestinal volvulus is mainly classified into two subtypes, mesentero-axial volvulus and organo-axial volvulus. The detailed imaging findings of organo-axial volvulus of the small intestine have never been reported as far as we know. In this article, we report a case of organo-axial volvulus of the small intestine, focusing on the computed tomography (CT) findings. An 80-year-old man was radiologically diagnosed as having organo-axial volvulus of the terminal ileum and it was confirmed by open surgery without adhesion or any other anatomical abnormalities. CT showed two specific findings, split-bowel sign and rotating-C sign, which we think reflect pathophysiologic features of organo-axial volvulus. We think the pathogenic mechanism of organo-axial volvulus can be explained by the convergence of the reversed-rotational twist following the formation of a twisted but non-obstructive circular loop, even if there is no adhesion. Radiologists should be aware that organo-axial volvulus can occur even in the small intestine, and in the case of small bowel obstruction with single transition point, the two pathophysiologic signs mentioned above must be looked for to diagnose the possibility of organo-axial volvulus.

Closed loop obstruction: pictorial essay

Closed loop obstruction occurs when a segment of bowel is incarcerated at two contiguous points. The diagnosis is based on multiple transitional zones. The incarcerated loops appear in U or C form or present a radial layout around the location of the obstruction. It's very important to specify the type of obstruction because, in patients with simple bowel obstruction, a conservative approach is often advised. On the other hand, a closed loop obstruction immediately requires a surgical approach because of its high morbidity and the risk of death in case of a late diagnosis.