Video-assisted thoracoscopic surgery as a diagnostic and therapeutic instrument in non-tubercular spondylodiscitis

Discussion

Spondylodiscitis can be classified as pyogenic, granulomatous (tuberculosis, brucellosis, fungal) or parasitic. ^{1, 4} The pathogenesis of pyogenic spondylodiscitis can be haematogenous, by external inoculation or by spread from contiguous tissues.1 Haematogenous pyogenic spondylodiscitis is predominant,1 with Staphylococcus aureus as the most common causative agent,^{1, 4} followed by enterobacteria.¹ Pseudomona aureaginosa is often seen in intravenous drug users. Also Coagulase negative staphylococci, Streptococci and Enterococci have been described.¹ Proteus mirabilis is less common and was found in 0.9% of cases.⁴

X-rays may be useful if spondylodiscitis is suspected. However, large destructive spondylodiscitis is not always recognized on X-rays as changes may take months to appear. Moreover, it can be difficult to distinguish infection from degenerative changes.¹ This is evident in the present case; the abnormalities seen on X-rays eight days prior to admission were probably an indication of spondylodiscitis. Gadoliniumenhanced MRI is the imaging modality of choice for diagnosing spondylodiscitis. CT is the best imaging modality to delineate areas of bone destruction, which is useful for surgical planning.¹

Initial therapy for spondylodiscitis is drug treatment. Also when surgery is indicated, additional drug treatment is essential. Indications for surgical treatment include compression of neural elements, spinal instability due to bone destruction, severe deformities such as kyphosis or if conservative treatment does not improve the patients’ condition. The presence of spinal cord compression is an indication for immediate surgical decompression.¹ However, if a patient is paralyzed preoperatively, surgical decompression is unlikely to undo paralysis.⁴

Open surgery is nowadays still the standard, particularly in cases of large bone destruction.¹ However, indications for VATS are similar to those requiring open techniques. VATS can be used when lesions involve the anterior spinal column, from T2-L1.³ The VATS procedure has been described in literature mostly in cases of thoracic disk herniation and scoliosis. ² VATS can also be a useful alternative to conventional thoracotomy in tubercular thoracic spondylitis. ^{2, 3} However, thoracoscopy is not indicated for all patients. The contraindications for this technique are patients’ intolerance to one-lung ventilation or severe pleural adhesions.^{2, 3}

Major advantages of VATS are the reduction of intraoperative blood loss, shorter postoperative stay and cosmetically appealing minor surgical scars along with less postoperative pain, when compared with thoracotomy.²

In this study, VATS offered a minimally invasive access to obtain the diagnosis of pyogenic spondylodiscitis and provided treatment with abscess drainage and decompression of the spinal cord. VATS can be considered as a valuable diagnostic and therapeutic instrument for spondylodiscitis, due to its minimal invasive approach.