Ultrasonic spine surgery for every thoracic disc herniation: a 43-patient case series and technical note demonstrating safety and efficacy using a partial transpedicular thoracic discectomy with ultrasonic aspiration and ultrasound guidance

OBJECTIVE Thoracic disc herniations (TDHs) are a challenging pathology. A variety of surgical techniques have been used to achieve spinal cord decompression. This series elucidates the versatility, efficacy, and safety of the partial transpedicular approach with the use of intraoperative ultrasound and ultrasonic aspiration for resection of TDHs of various sizes, locations, and consistencies. This technique can be deployed to safely remove all TDHs. METHODS A retrospective review was performed of patients who underwent a thoracic discectomy via the partial transpedicular approach between January 2014 and December 2020 by a single surgeon. Variables reviewed included demographics, perioperative imaging, and functional outcome scores. RESULTS A total of 43 patients (53.5% female) underwent 54 discectomies. The most common presenting symptoms were myelopathy (86%), motor weakness (72%), and sensory deficit (65%) with a symptom duration of 10.4 ± 11.6 months. A total of 21 (38.9%) discs were fully calcified on imaging and 15 (27.8%) were partially calcified. A total of 36 (66.7%) were giant TDHs (> 40% canal compromise). The average operative time was 197.2 ± 77.1 minutes with an average blood loss of 238.8 ± 250 ml. Six patients required ICU stays. Hospital length of stay was 4.40 ± 3.4 days. Of patients with follow-up MRI, 38 of 40 (95%) disc levels demonstrated < 20% residual disc. Postoperative Frankel scores (> 3 months) were maintained or improved for all patients, with 28 (65.1%) patients having an increase of 1 grade or more on their Frankel score. Six (14%) patients required repeat surgery, 2 of which were due to reherniation, 2 were from adjacent-level herniation, and 2 others were from wound problems. Patients with calcified TDHs had similar improvement in Frankel grade compared to patients without calcified TDH. Additionally, improvement in intraoperative neuromonitoring was associated with a greater improvement in Frankel grade. CONCLUSIONS The authors demonstrate a minimally disruptive, posterior approach that uses intraoperative ultrasound and ultrasonic aspiration with excellent outcomes and a complication profile similar to or better than other reported case series. This posterior approach is a valuable complement to the spine surgeon’s arsenal for the confident tackling of all TDHs.

690 Intracranial Hypotension Due to CSF Leak Secondary to Ventral Thoracic Osteophyte Complex: Resolution After Transdural Thoracic Discectomy and Dural Repair

The hallmark symptom of spontaneous intracranial hypotension (SIH) is orthostatic headaches which manifests secondary to cerebrospinal fluid (CSF) hypovolaemia. Well-recognised aetiologies include trauma which includes procedures such as lumbar punctures and spinal surgery. More recently, structural defects such as bony osteophytes and calcified or herniated discs have been attributed to mechanically compromising dural integrity consequently resulting in CSF leak and symptom manifestation. A thorough literature review noted only a handful of such cases. We report the case of a thirty-two-year-old Asian female who presented with a one-month history of new-onset progressively worsening orthostatic headaches. Workup included MRI of the thoracic spine which revealed an epidural collection of CSF consequently prompting a dynamic CT-myelogram of the spine which not only helped to confirm severe cerebral hypotension but also suggested the underlying cause as being a dorsally projecting osteophyte-complex at level T2-3. Conservative and medical management including bed rest, analgesia, mechanical compression, and epidural blood patches failed to alleviate symptoms and a permanent surgical cure was eventually sought. The surgery involved T2-T3 laminectomy and osteophytectomy and at a 3-month follow-up, complete resolution of symptoms was noted.