Effects of indirect foraminal decompression during anterior cervical disc fusion procedure: preliminary results of a prospective study with clinical and radiological outcomes

INTRODUCTION

The respective effects of direct and indirect decompression in the clinical outcome after anterior cervical disc fusion (ACDF) is still debated. The main purpose of this study was to analyze the effects of indirect decompression on foraminal volumes during ACDF performed in patients suffering from cervico-brachial neuralgias due to degenerative foraminal stenosis, i.e. to determine whether implant height was associated with increased postoperative foraminal height and volume.

METHODS

A prospective follow-up of patients who underwent ACDF for cervicobrachial neuralgias due to degenerative foraminal stenosis was conducted. Patient had performed a CT-scan pre and post-operatively. Disc height, foraminal heights and foraminal volumes were measured pre and post operatively.

RESULTS

37 cervical disc fusions were successfully performed in 20 patients, with a total of 148 foramina studied. Foraminal height and volume were measured bilaterally on the pre- and post-operative CT scans (148 foramina studied). After univariate analysis, it was found a significant improvement for every radiological parameter, with a significant increase in disc height, foraminal height and foraminal volume being respectively +3,22 mm (p < 0,001), +2,12 mm (p < 0,001) and +54 mm3 (p < 0,001). Increase in disc height was significantly associated with increase in foraminal height (p < 0,001) and foraminal volume (p < 0,001). At the same time, increase in foraminal height was significantly correlated with foraminal volume (p < 0,001), and seems to be the major component affecting increasing in foraminal volume.

CONCLUSION

Indirect decompression plays an important part in the postoperative foraminal volume increase after ACDF performed for cervicobrachial neuralgias.

Tomodensitometric bone anatomy of the intervertebral foramen of the lower cervical spine: measurements and comparison of foraminal volume in healthy individuals and patients suffering from cervicobrachial neuralgia due to foraminal stenosis

PURPOSE

Degenerative foraminal stenosis of the cervical spine can lead to cervicobrachial neuralgias. Computed tomography (CT)-scan assists in the diagnosis and evaluation of foraminal stenosis. The main objective of this study is to determine the bony dimensions of the cervical intervertebral foramen and to identify which foraminal measurements are most affected by degenerative disorders of the cervical spine. These data could be applied to the surgical treatment of this pathology, helping surgeons to focus on specific areas during decompression procedures.

METHODS

A descriptive study was conducted between two groups: an asymptomatic one (young people with no evidence of degenerative cervical spine disorders) and a symptomatic one (experiencing cervicobrachial neuralgia due to degenerative foraminal stenosis). Using CT scans, we determined a method allowing measurements of the following foraminal dimensions: foraminal height (FH), foraminal length (FL), foraminal width in its lateral part ((UWPP, MWPP and IWPP (respectively Upper, Medial and Inferior Width of Pedicle Part)) and medial part (UWMP, MWMP and IWMP (respectively Upper, Medial and Inferior Width of Medial Part)), and disk height (DH). Foraminal volume (FV) was calculated considering the above data. Mean volumes were measured in the asymptomatic group and compared to the values obtained in the symptomatic group.

RESULTS

Both groups were made up of 10 patients, and a total of 50 intervertebral discs (100 intervertebral foramina) were analyzed in each group. Comparison of C4C5, C5C6 and C6C7 levels between both groups showed several significant decreases in foraminal dimensions (p < 0.05) as well as in foraminal volume (p < 0.001) in the symptomatic group. The most affected dimensions were UWPP, MWPP, UWMP, MWMP and FV. The most stenotic foraminal areas were the top of the uncus and the posterior edge of the lower plate of the overlying vertebra.

CONCLUSION

Using a new protocol for measuring foraminal volume, the present study refines the current knowledge of the normal and pathological anatomy of the lower cervical spine and allows us to understand the foraminal sites most affected by degenerative stenosis. Those findings can be applied to foraminal stenosis surgeries. According to our results, decompression of the foramen in regard of both uncus osteophytic spurs and inferior plate of the overlying vertebra might be an important step for spinal nerves release.

Blood loss and perioperative transfusions related to surgery for spinal tumors. Relevance of tranexamic acid

INTRODUCTION

Tranexamic acid (TXA) has been shown to reduce bleeding. Patients with spinal tumors are fragile and acute anemia may be harmful. Tumor excision surgery is reputed to be hemorrhagic and treatment may increase thromboembolic complications. The aim of this study was to compare blood loss with or without perioperative TXA injection. The transfusion-related and postoperative complications were documents.

METHOD

This retrospective analysis of prospectively collected data involved 83 patients with spinal tumors who underwent decompressive surgery associated with bone fixation. Tranexamic acid was used arbitrarily in 36 of them, while the other 47 did not receive TXA. The overall, intraoperative and postoperative blood loss was recorded. Blood loss was reported relative to the number of fixed levels and the number of levels decompressed by laminectomy. Transfusions were quantified in number of red blood cell packets and erythrocyte volume. Postoperative complications were documented.

RESULTS

Epidemiological and morphological data were similar between groups. There were no significant differences between the two groups in the overall, intraoperative, and postoperative blood loss. A significant reduction in postoperative bleeding was found in the TXA group when the volume was related to the number of decompressed levels. A significant reduction (P<0.05) in the volume of transfused blood was identified in the treated group. No predictor of blood loss was identified, and no additional complications occurred.

CONCLUSION

The efficacy of TXA appears to be moderate during spinal tumor surgery since it does not lead to a reduction in perioperative bleeding. However, a significant reduction in transfusion volume was found without an increase in complications.

Symptomatic compressive pneumocephalus following lumbar decompression surgery

We report a case of symptomatic postoperative pneumocephalus after lumbar decompression. A 69-year-old man was operated on for a severe lumbar stenosis with a L2-L4 arthrodesis and a spinal decompression. No cerebrospinal fluid leakage was visible but one of the two aspirative drains was accidentally disconnected in recovery room. After 1 day, computed tomography was performed to explore intense lumbar pain and revealed a voluminous pneumorachis. Then, the patient experienced a generalized tonic-clonic seizure. Imaging revealed a voluminous pneumocephalus responsible for a significant space-occupying effect on the frontal lobe. A conservative treatment was initiated, including bed rest, oxygen therapy, neurological monitoring and anti-epileptic therapy. Symptoms gradually improved and he was discharged without any deficit after 10 days. A total radiological regression was noted in 21 days. Prevention of postoperative pneumocephalus should include a systematic repair of iatrogenic dural tear. Even in presence of severe symptomatic manifestations, a conservative treatment is possible.