THORASCOPIC ANTERIOR RELEASE – A NEW TECHNIQUE

Abstract

INTRODUCTION: Thorascopic techniques are an accepted and useful technique for spinal surgery. For certain clinical indications (ie thoracic kyphosis), an anterior spinal release followed by a posterior instrumentation may be indicated. The standard technique for a thorascopic anterior release is with the patient in the lateral decubitus position and intubated with a double lumen endotracheal tube (ETT), allowing one lung to be deflated for access to the spine. Placing a double lumen ETT and repositioning the patient before the posterior surgery both add to the duration of surgery. We report our initial experience using standard ETT ventilation, low pressure CO₂ insufflation into the thorax to push the lung away from the operative field, and prone positioning, for thorascopic anterior spinal release, followed by posterior instrumentation. Although previously described for thoracic surgery ^1,2, this technique has not been reported for spinal procedures.

METHODS: Five male patients, mean age 15.4 years (13–17 years) have undergone thorascopic anterior release and posterior instrumentation as described CO₂ insufflation pressure was maintained at 6 above. mm Hg or less. There were three cases of Scheuermanns disease and two progressive kyphosis post laminectomy for intradural tumours. Clinical, operative (including intraoperative physiological measurements) and radiological data have been collected by a retrospective chart review.

RESULTS: In all cases the anterior release was performed successfully followed by posterior instrumentation. Three portals were used in each and three to five levels released. Mean time from start of anaesthesia to completion of anterior release was 140 minutes. Intra-operative physiological measurements (EtCO₂, SaO₂, pulse, BP) remained stable in all cases during the endoscopic procedure. All patients were extubated post-operatively, spent 24 hours in ICU, and remained in hospital for a mean of nine days (7 – 13 days). There were no significant complications. Mean kyphosis angle improved from 82 degrees pre-operatively to 50 degrees postoperatively.

DISCUSSION: Our initial experience with this new technique has been encouraging. There have been concerns regarding the physiological effects of inducing a tension pneumothorax³, although our results are similar to others who have found low pressure CO₂ insufflation to be safe². The prone positioning is especially suited for anterior release of a kyphotic spine as it allows the lung to fall away from the spine. Overall we feel this is a useful technique for anterior release of a kyphotic spine.