Spinal Dural Arteriovenous Fistula Presenting as a Recurrent Nucleus Pulposus Herniation: A Case Report and Literature Review

Extravertebral low back pain: a scoping review

BACKGROUND

Low back pain (LBP) is one of the most common reasons for consultation in general practice. Currently, LBP is categorised into specific and non-specific causes. However, extravertebral causes, such as abdominal aortic aneurysm or pancreatitis, are not being considered.

METHODS

A systematic literature search was performed across MEDLINE, Embase, and the Cochrane library, complemented by a handsearch. Studies conducted between 1 January 2001 and 31 December 2020, where LBP was the main symptom, were included.

RESULTS

The literature search identified 6040 studies, from which duplicates were removed, leaving 4105 studies for title and abstract screening. Subsequently, 265 publications were selected for inclusion, with an additional 197 publications identified through the handsearch. The majority of the studies were case reports and case series, predominantly originating from specialised care settings. A clear distinction between vertebral or rare causes of LBP was not always possible. A range of diseases were identified as potential extravertebral causes of LBP, encompassing gynaecological, urological, vascular, systemic, and gastrointestinal diseases. Notably, guidelines exhibited inconsistencies in addressing extravertebral causes.

DISCUSSION

Prior to this review, there has been no systematic investigation into extravertebral causes of LBP. Although these causes are rare, the absence of robust and reliable epidemiological data hinders a comprehensive understanding, as well as the lack of standardised protocols, which contributes to a lack of accurate description of indicative symptoms. While there are certain disease-specific characteristics, such as non-mechanical or cyclical LBP, and atypical accompanying symptoms like fever, abdominal pain, or leg swelling, that may suggest extravertebral causes, it is important to recognise that these features are not universally present in every patient.

CONCLUSION

The differential diagnosis of extravertebral LBP is extensive with relatively low prevalence rates dependent on the clinical setting. Clinicians should maintain a high index of suspicion for extravertebral aetiologies, especially in patients presenting with atypical accompanying symptoms.

Acquired Lumbosacral Spinal Dural Arteriovenous Fistula in Association with Degenerative Lumbosacral Disc Herniation and Spinal Canal Stenosis: Report of Two Cases and Review of the Literature

The authors describe two cases harboring lumbosacral spinal dural arteriovenous fistulas (SDAVFs) manifested with nonspecific initial symptoms, leading to misdiagnosis and unnecessary procedures. A curvilinear flow void in the lumbar region and thoracic cord congestion with subtle perimedullary flow voids were detected on magnetic resonance imaging (MRI) in both patients. Contrast-enhanced magnetic resonance angiography and spinal angiography confirmed the SDAVFs in the lower lumbar and sacral region. Both fistulas were located at the same level of disc herniation and spinal canal stenosis and supplied by branches of the internal iliac arteries (i.e., iliolumbar and lateral sacral arteries) with cranial drainage from the dilated vein of the filum terminale, corresponding to a curvilinear flow void, to the perimedullary veins. The first case was successfully treated with embolization. Another case had recanalization of the fistula 4 months after endovascular treatment and was successfully treated with surgical interruption of the fistula. Our two case reports may provide additional evidence supporting an acquired etiology of SDAVFs, probably secondary to lumbosacral disc herniation and spinal canal stenosis. The authors also reviewed literature about preexistent lumbosacral SDAVFs associated with disc herniation and spinal canal stenosis. From our review, the level of SDAVFs in most patients is correlated with the level of disc herniation, spondylolisthesis, and/or spinal stenosis.