A Comparison Between the Prone and Lateral Position for Performing a Thoracoscopic Anterior Release and Fusion for Pediatric Spinal Deformity

Purpose: The lateral position has traditionally been used when performing a thoracoscopic anterior spinal release and fusion (ASF) during a single stage ASF/PSF with instrumentation. Although some have reported the thoracoscopic technique in the prone position there are no direct comparison studies. The purpose of this study was to analyze the results of patients undergoing a thoracoscopic ASF comparing those performed prone with those in the lateral position.

Methods: A retrospective review was performed of all patients who had a single stage thoracoscopic ASF/PSF with posterior instrumentation. The medical record was reviewed to determine positioning of the patient, levels fused, anesthesia time, operative time, chest tube drainage, chest x-ray results and complications. Radiographs were reviewed to determine curve magnitude and curve correction. The student’s t test was used and statistical significance was defined as p<0.05.

Results: There were 16 patients in the prone group (P) and 27 in the lateral group (L). All patients had a single stage thoracoscopic ASF/PSF with instrumentation. In group P, the patient was positioned prone on a Hall-Relton frame for both the ASF and PSF. There were no differences between the P and L groups with respect to age, sex, height, weight and curve magnitude (73.8E vs 71.5E). There was a slightly less number of fused anterior levels in the P group (5.3 vs 6.2) (p=0.05). When analyzing parameters which reflect potential difficulties imposed by the prone position, there were no differences between group P and L in anterior operative time/disc (24.3 vs 25.9 min/disc), blood loss/anterior disc level (33.5 vs 26.8 cc/disc), total chest tube drainage (445 vs 419 cc) or days with the chest tube in place (2.2 vs 2.3 days). There were significant differences between the P and L groups with respect to anesthesia preparation time (42.8 vs 64.8 min), delay between the completion of the anterior procedure and the start of the posterior procedure (11.8 vs 69.5 min) and the incidence of complications related to the use of single lung ventilation (0 vs 14.8%)(p<0.05). Patients in the P group required less time on oxygen postoperatively (34.8 vs 51.6 hrs) and were discharged earlier (4.6 vs 5.5 days) (p<0.05).

Conclusions: A thoracoscopic ASF in the prone position appears to achieve the same results as when performed in the lateral position. The prone position saves time in the operating room due to decreasing the time needed by the anesthesiologists and the transition time between the ASF and PSF. Potentially serious complications related to single lung ventilation are avoided with bilateral lung ventilation in the prone position.