Discectomies for Symptomatic Herniated Discs with Radiculopathy

Although clinically relevant, symptomatic thoracic disc herniations are rare, the traditional thoracotomy approach to treat this condition can result in significant perioperative morbidity. Thoracoscopy has been used successfully to decompress thoracic herniations with equivalent clinical outcomes compared with open approaches. Rosenthal and Dickman were one of the first groups to report their experience with thoracoscopic decompression of thoracic herniation. In their series of 55 patients, they observed shorter operative time, less blood loss, and shorter hospital stay compared with a similar group of patients who underwent costotransversectomy with less perioperative complications. Anand and Regan have reported their results of 100 consecutive cases of thoracic disease treated by VATS with 2-year follow-up. In this series, the mean operative time was 173 minutes and average intraoperative blood loss was 259 mL. After 2 years, the objective clinical success was 70%, with an overall patient satisfactory rate of 84%. In 2002, Han et al. reported the outcomes of 60 thoracoscopic discectomies in 57 patients. A complete decompression was achieved in 98% of the cases. The mean operative time was 3 hours 11 minutes, the estimated blood loss averaged 310 mL, and the mean hospital stay was 2.5 days. Only three patients required a second operation to remove retained disc fragments. The authors concluded that VATS is an efficacious and relatively safe treatment of refractory symptomatic thoracic disc herniations. More recently, in 2005, Oskouian and Johnson reported a prospective study of patients who underwent endoscopic thoracic microdiscectomy. Improvement of two Frankel grades was observed in patients with myelopathy in the thoracoscopic discectomy group, and radiculopathy symptoms improved by 75%. However, the patients in the thoracotomy group with significantly worse conditions before surgery improved one Frankel grade. Collectively, thoracoscopic discectomy yields acceptable surgical results and improved clinical outcomes with less morbidity, as assessed by reduced postoperative pain, blood loss, and length of hospitalization.

Adult Deformity Correction

VATS is a valuable addition to the armamentarium for the treatment of adult secondary degenerative thoracic spinal deformity. The main goals of anterior approaches for adult spinal deformity surgery are to obtain both coronal and sagittal spine balance, to obtain a solid fusion, and to perform the surgery safely with minimal complications. Endoscopic-assisted techniques allow the surgeon to achieve the goals of anterior release and bone grafting in a less invasive fashion with less trauma to surrounding tissues. The senior author’s indications for an anterior release in cases of adult spinal deformity include curves greater than 60 degrees in magnitude with less than 50% correction on bending films, and curves that require stable zone coronal and sagittal plane alignment.

The clinical and radiographic outcomes for VATS are at least comparable with the open approach for anterior transthoracic spine deformity correction. Although most of the published reports examined surgery performed in the adolescent pediatric population, similar results can be expected for correction of adult degenerative thoracic spine deformity. In Mack et al.’s early series of 95 patients who underwent VATS, 27 had anterior spinal release for spinal deformity, reduced morbidity, and shorter length of hospital stay. In another series by King et al., mean correction of scoliosis was 67.3% in 20 patients. Newton et al. report on 9 cases of Scheuermann kyphosis with a preoperative Cobb angle of 78 degrees and a postoperative angle of 44 degrees. This represents close to a 50% correction, which is consistent with open techniques. They also compared the VATS group with a group of patients who had open thoracotomy approaches and found similar complication rates.

In 2005, Al-Sayyad et al. published “the Cincinnati experience” with video-assisted thoracoscopic surgery in a consecutive series of 100 patients with a minimum of 3-year follow-up. The patients’ diagnoses ranged from idiopathic scoliosis (n = 49), neuromuscular spinal deformity (n = 15), Scheuermann kyphosis (n = 15), congenital and infantile scoliosis (n = 5), neurofibromatosis (n = 5), Marfan (n = 1), postradiation scoliosis (n = 1), and repair of pseudoarthrosis (n = 1). One had anterior arthrodesis after fracture-dislocation of the thoracic spine, and another had anterior fusion for vertebral osteomyelitis. Final postoperative scoliosis and kyphosis corrections were 68% and 90%, respectively. Complications occurred in only 8 of 100 patients. Al-Sayyad et al. conclude that VATS is an effective and relatively safe technique for the treatment of thoracic spinal deformities.

In a retrospective study comparing the mini-open thoracoscopically assisted thoracotomy and VATS for anterior release and fusion in thoracic scoliosis and kyphosis in 45 patients, Levin et al. show that VATS allows more extensive access to the thoracic spine, thereby facilitating fusion to more levels. Furthermore, although not significant, there was a trend toward less blood loss per operated level in the VATS group. More importantly, again, VATS was demonstrated to be at least comparable in degree of release to traditional open thoracotomy for adult scoliotic deformity correction. Moreover, with the recent advancement and commercial availability of navigational systems, three-dimensional video assistance, and robotic assistance, the future utility of VATS in the management of spinal deformity is ensured.

Spinal Fractures

It is not uncommon for thoracic and thoracolumbar vertebral compression fractures (VCFs) to require anterior decompression with or without instrumentation for stabilization. Fracture management with VAT-vertebrectomy and fusion with or without supplemental posterior pedicle screw fixation has been tried with measurable success. An early report by Dickman et al. found comparable outcome in fracture treatment between VAT-vertebrectomy and open thoracotomy. In that study, there was no significant difference in both the operative time and intraoperative blood loss between the two groups. The patients in the VAT-vertebrectomy group required significantly less narcotic and had shorter stays in both the ICU and the hospital. In another series, Hertlein et al. report on seven patients with unstable fractures of the upper thoracic spine who underwent a circumferential fusion first with posterior transpedicular screw fixation systems and a simultaneous posterior iliac crest bone graft, followed by delayed anterior thoracoscopic decompression and bone grafting. No postoperative morbidity was reported and no loss of sagittal alignment after an 8-month average follow-up. In 1997, Huang et al. modified the technique to include an extended manipulating VATS channel. In their description, an extended (or working) portal of 5 to 6 cm in length was placed at the injured level to facilitate easy fracture reconstruction.

Recently, Khoo et al. reviewed 371 patients with thoracolumbar fractures managed with either VATS alone (35% of patients) or with VATS and supplemental posterior pedicle screw construct, and found that the VATS-treated patients had a significant reduction in narcotics use and ICU/hospital stay compared with the 30 patients treated with open thoracotomy. The overall major complication rate was 1.3%. Although both the operative time and intraoperative blood loss were comparable between the two groups, they conclude that VATS for spinal fracture reconstruction can be safely and effectively accomplished, and should be considered as an alternative to the conventional thoracotomy and thoracolumbar approaches.

In 2006, Hoshino et al. described a new endoscopic vertebral augmentation technique for the treatment of chronic, painful VCFs. An inflatable balloon catheter is deployed in the vertebral body using a transpedicular approach to provide room for endoscopic visualization. One pedicle is then used as a working portal to evaluate granulation tissue from the vertebral body under endoscopic guidance from the contralateral pedicle. The augmentation is performed by injecting calcium phosphate cement (CPC) into the vertebral body. In Hoshino et al.’s study, 14 patients underwent the procedure with significant improvement in both pain and ambulatory function. Bone formation was observed in all cases secondary to the osteoconductive capacity of CPC, thereby facilitating the ultimate restoration of vertebral ultrastructure and anatomy. The authors conclude that endoscopic-assisted vertebral augmentation is an efficacious procedure for the treatment of chronic, painful VCFs.