[Anterior spinal fusion by thoracoscopy. A non-traumatic technique].

PURPOSE OF THE STUDY

Video assisted thoracic surgery (VATS) is a new modality which allows visualization of, and access to the intrathoracic organs without thoracotomy. Recently, this technique has been used for anterior thoracic spine approach to perform surgery which previously required standard postero-lateral thoracotomy. The authors report their initial experience of anterior spinal fusion using thoracoscopy and give a detailed description of their surgical procedure.

MATERIAL AND METHODS

This technique, started on June 1993, was performed only in one level 1 in 10 patients who had thoracic spine trauma with fracture or luxation. The procedure was performed in the lateral decubitus position. The patient was prepared in the standard manner for a full thoracotomy. Surgical instruments that are needed for conversion to an open procedure must be in the operative room. Ventilation was stopped to the ipsilateral lung. Lung's collapse of the surgical side was obtained with a double lumen tube. Carbon dioxide (CO2) insufflation was used to further collapse. The first thoracoscopic portal was placed through the sixth or seventh intercostal space in the posterior axillary line, which was the safest place. All subsequent portals were placed under thoracoscopic visualization, in a triangular way as recommended by Landreneau (1992). Only open trocars were used to avoid complication of CO2 insufflation. Once the target level has been defined, a needle was placed into the disc space and roentgenographic confirmation obtained. The parietal pleura was then divided using monopolar electrocautery. Segmental vessels of the operation field lied transversely across the midportion of the vertebral body. They were mobilised and systematically ligated with endoscopic clip to simplify the procedure. Then the intervertebral space was opened and bone and disc were removed, restricted to the anterior and middle third. The graft was placed into the thoracic cavity by using a high density calcium hydroxyapatite ceramic block. Peroperative radiologic control ascertained the good position of the implant. At the end of the procedure a chest tube was placed through the lower trocar site and the lung re-expanded. A post operative CT Scan controlled good position of the graft and complete lung expansion. Contra-indications for VATS are previous surgical procedures or empyema causing extensive pleural adhesions. Procedures not appropriate for VATS approach are some that require anterior instrumentation for stabilisation, burst fracture, or fracture with posterior wall involved.

RESULTS

The planned procedure was accomplished in all but one patient who required conversion to an open procedure because of segmental artery bleeding. Mean operative time was 1 h 45 mm, and mean estimated blood loss was 650 cc. There was no complication from CO2 insufflation neither postoperative complication. With an average of 2 years follow up, anterior grafting is as good as an open technique, radiologic evaluation according to Uchida (1990) showed good incorporation of each block without any radiolucent line or displacement.

DISCUSSION

According to literature this technique was performed safely in 10 cases, especially without any respiratory complications and chronic pain (impairement of pulmonary function, re-expansion failure, incisional complications, rib fractures, chronic pain and malfunction of the chest wall, limitation of shoulder girdle motion) which are considered to be the main disadvantage of traditional thoracotomy. Many authors previously used VATS for multi level thoracic discectomy for correction of spinal deformities (Mack 1995), spinal reconstructive surgery (Mac Afee 1995) or removal of protrude thoracic disc (Rosenthal 1994).

CONCLUSION

This original technique demonstrates that thoracoscopy for anterior thoracic surgery is better for the patients, reducing surgical trauma of the chest wall and to the lung parenchyma (in term of post operative comfort, sh