Diagnosis of vertebral canal haematoma by myelography and spiral computer tomography in a patient with an implantable cardioverter-defibrillator contraindicating magnetic resonance imaging

Abstract

Editor—We report a case of a large vertebral canal haematoma (VCH) after the insertion of a thoracic epidural catheter in a 78-yr-old man. The patient presented for a laparoscopic sigmoid colon resection at Luebeck University Hospital, Germany. The patient had suffered a myocardial infarction in 2004 after which he received an implantable cardioverter-defibrillator. In addition, he was being treated for hypertension and diabetes mellitus type 2. The evening before surgery deltaparin 5000 IE was administered s.c. at 20:00 h. Before induction of anaesthesia, a thoracic epidural catheter was inserted at the T9/10 interspace with the patient sitting. Sufentanil 20 µg was injected into the epidural catheter and on commencing the operation, an epidural pump was started administering ropivacaine 0.2% at 6 ml h−1. After uneventful surgery, the patient had normal lower limb motor function. At midnight, the patient received his first postoperative dose of deltaparin 5000 IE s.c., and at 04:00 h (postop day 1), he complained that he was unable to move his legs. The anaesthetist on call stopped the patient-controlled epidural analgesia (PCEA) pump and 3 h after that the motor block disappeared. The PCEA pump was then restarted at a reduced rate of 4 ml h−1. During the morning of the second postoperative day, he developed a motor weakness of the right thigh. At 15:00 h, a neurological consult ruled out peripheral nerve damage and at 18:00 h radiological investigation was started. Owing to the implanted automated cardioverter-defibrillator, magnetic resonance imaging (MRI) was withheld, but a high definition spiral computer tomography (CT) did not reveal any pathology. Hence, a conventional, ascending myelography was undertaken which showed a significant bilateral narrowing of the contrast dye at level T6 to T10. The post-myelographic CT confirmed the suspected VCH ranging from T5/6 to T10/11 with complete compression of the subarachnoid space at level T7 to T9 (Fig. 1). At 22:00 h, the patient underwent emergency decompression laminectomy. After 3 weeks, all neurological symptoms had subsided. The low incidence of major complications after central neuraxial block has just been confirmed by a large national audit project.1Cook TM Counsell D Wildsmith JAW Major complications of central neuroaxial block: report on the Third National Audit Project of the Royal College of Anaesthetists.Br J Anaesth. 2009; 102: 179-190Crossref PubMed Scopus (575) Google Scholar The major issue leading to permanent patient harm in the past has been delay in the diagnosis, drainage of a haematoma, or both, as recently reviewed.2Meikle J Bird S Nightingale JJ White N Detection and management of epidural haematomas related to anaesthesia in the UK: a national survey of current practice.Br J Anaesth. 2008; 101: 400-404Crossref PubMed Scopus (32) Google Scholar Notably, at present, there is a debate whether or not implanted cardiac devices prove a contraindication for MRI scanning3Sierra M Machado C Magnetic resonance imaging in patients with implantable cardiac devices.Rev Cardiovasc Med. 2008; 9: 232-238PubMed Google Scholar and a safety protocol for non-cardiac and cardiac MRI in these patients has been proposed.4Nazarian S Roguin A Zviman MM et al.Clinical utility and safety of a protocol for noncardiac and cardiac magnetic resonance imaging of patients with permanent pacemakers and implantable-cardioverter defibrillators at 1.5 tesla.Circulation. 2006; 114: 1277-1284Crossref PubMed Scopus (286) Google Scholar However, if it has been decided that MRI scanning is unsafe for the patient, even a high definition spiral CT may be unable to detect even large VCHs and only conventional myelography with consecutive CT scanning will establish a diagnosis. In our case, the reduction of the PCEA infusion rate on the first postoperative day primarily led to a significant reduction in the motor block, which reoccurred on the second postoperative day. The neurological consultation and the radiological imaging took a considerable amount of time, before the patient finally underwent emergency decompression laminectomy. Despite that time interval, the patient made a full neurological recovery. This case highlights the overall complexity of the management of paraplegia after epidural anaesthesia in a patient unable to undergo MRI scanning. Appendix 4 of the NAP3 report gives an example of an algorithm to manage patients who have weak legs after neuraxial blocks. In addition, it is desirable that the diagnostic pathway is equally predefined, so that patients who are unable to undergo MRI scanning can be diagnosed without delay.