The classic approach to access the anterior thoracic spine is either a thoracotomy or thoracoabdominal exposure, both of which require extensive soft tissue dissection. Video-assisted thoracoscopy surgery (VATS) has gained interest recently as an alternative approach to treating anterior thoracic pathology. By using endoscopic visualization and small working portals, this technique provides a less invasive method of accessing this difficult area of the spine with fewer postoperative morbidities.
Indications for VATS
Thoracic disc degeneration or herniation
Thoracic spinal stenosis
Adult secondary degenerative thoracic deformity
Contraindications to VATS
Extensive scarring and adhesions from prior open thoracotomy
Acute or severe respiratory insufficiency
Empyema, pleurodesis, or bullous lung pathology
Narrow anteroposterior chest diameter, spine deformity, or both, which would limit the space to work
Advantages of VATS
Less postoperative pain
Less blood loss
Smaller, more cosmetic incisions
Less ventilatory compromise
Less operative time and shorter hospital stay
Disadvantages of VATS
Expensive, specialized instruments
Specially trained personnel needed
Increased cost compared with open procedures
Although the lateral position may be more familiar anatomically, the prone position allows the mediastinal organs to fall away, making retraction unnecessary.
For discectomy, the rib head is removed over the involved disc except for levels below T11.
Partial release of the anterior longitudinal ligament is often all that is necessary.
Ligation of the segmental vessels is unnecessary when no instrumentation is used.
The function of the double-lumen tube must be continuously monitored to minimize complications.
The first portal should be made at the midchest level to avoid penetration through the diaphragm into the abdomen.
Risk for aortic injury is approximately equal with endoscopic and open techniques, so care must be taken.
Operative levels should be checked by first counting the ribs and then verifying with an intraoperative radiograph.
Video-assisted thoracoscopy surgery (VATS) is a relatively new technique that uses a minimally invasive approach to treat anterior spinal pathology. It involves the use of an endoscope for visualization and magnification through small working portals. The primary goal is to effectively treat anterior spine pathology in a less invasive way, whereas concomitantly decreasing collateral tissue damage, thereby reducing the approach-related morbidity. In addition, it is reported to provide better access to the thoracic spine.
Although the history of endoscopic-assisted surgery dates back to 1850s, Jacobaeus, from Stockholm, Sweden, was the first to perform diagnostic and therapeutic thoracoscopic and laparoscopic procedures for the lysis of tuberculosis lung adhesion in 1910. In the 1970s and 1980s, the gynecologists and general surgeons championed the successful use of laparoscopic techniques for therapeutic procedures. Furthermore, innovative advances in anesthetic techniques played a significant role in the success of endoscopic-assisted surgeries. In orthopedics, endoscopic techniques are now used to effectively treat both knee and shoulder pathologies. However, it was not until Mack et al. demonstrated the application of VATS for spine disease that the technique was shown as a valuable alternative for treatment of anterior spine conditions and gained rapid recognition across the United States.
As stated previously, the application of VATS represents a new technique with the same goals and objectives as the traditional approach. The classic approach to gain access to the anterior spine is either a thoracotomy or thoracoabdominal exposure. These exposures usually involve extensile incisions, significant muscle dissection, rib resections, and sometimes violation of the diaphragm. Intrapleural manipulation of the chest organs is necessary, which oftentimes affects normal pulmonary and shoulder girdle function. Furthermore, the patients develop significant postoperative pain that requires excessive analgesic use, which may extend their hospitalization. In addition, the patients are routinely dissatisfied with the cosmetic results of their surgeries. For these reasons, VATS, with its attendant advantages of smaller, more cosmetic incisions, less postoperative pain, and earlier functional restoration, is attractive to surgeons as an alternative method for the difficult to treat anterior and anterolateral spine conditions. Recent reports in the literature have demonstrated the benefits of VATS and provide reasonable evidence for its future utility for the treatment of anterior spine conditions.
VATS has been adopted for the treatment of thoracic degenerative spine disorders. Transthoracic microsurgical discectomies, anterior release of adult scoliotic or kyphotic deformities, osteotomies, and bone grafting for fusion can now be safely performed using this technique. In addition, newer applications of this technique include corpectomy, anterior spinal reconstruction and instrumentation, and resection of spinal tumors. More recently, McLain and St. Clair have described the use of video-assisted anterolateral decompression and spinal reconstruction of ventrally located spinal tumors.
PREREQUISITES AND CONTRAINDICATIONS FOR VIDEO-ASSISTED THORACOSCOPY SURGERY
Prerequisites for successful video-assisted thorascopic procedure come from proper patient selection, supportive and equipped operating rooms, and skilled, competent surgeons. Suitable candidates for VATS are those patients with preexisting pulmonary function compromise from either restrictive or obstructive lung pathology. In addition, thoracoscopy is better suited for patients with bleeding disorders and other metabolic derangements that affect proper cardiorespiratory functions. Moreover, it is important for the spine surgeons performing these procedures to have a detailed understanding of both the anterior spine anatomy and the surgical technique. In rare cases when the planned thoracoscopic procedure is aborted, a thoracic surgeon should be available unless the surgeon is both comfortable and competent to perform a traditional open thoracotomy. Furthermore, institutions must have appropriate anesthesia resources for management of double-lumen intubations, trained operating room personnel to perform both thoracotomy and VATS procedures, and available intensive care units (ICUs) for possible postoperative monitoring.
An absolute contraindication to VATS is extensive postoperative scarring and adhesions from prior open thoracotomy. Another contraindication is acute or severe respiratory insufficiency with associated high positive airway pressure ventilation. Other co-morbidities that will make a patient unsuitable for VATS include empyema, pleurodesis, bullous lung pathology, a narrow anterior posterior chest diameter, and/or significant vertebral rotation at the apex, which reduces the available working space. Although the decision whether to use VATS is case specific, patients with severe deformities might be better treated through an open thoracotomy.
INDICATIONS AND CLINICAL OUTCOMES
Degenerative thoracic spine pathologies of the anterior or anterolateral thoracic spine are rare, but when they become symptomatic, they can be treated with VATS with good clinical outcome. Conditions that are treated with VATS include thoracic disc degeneration, symptomatic disc herniation, thoracic spinal stenosis, adult secondary degenerative thoracic spinal deformity, and corpectomy with decompression and stabilization for spinal fractures.
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.
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.
ADVANTAGES AND DISADVANTAGES
VATS is a minimally invasive technique, and its potential benefits and pitfalls are similar to other approaches within this family. The advantages of VATS include improved visualization of the target tissues; less postoperative pain (because of less muscle dissection and no rib spreading); less blood loss; smaller, more cosmetic incisions; less ventilatory compromise; reduced recovery time with minimal shoulder dysfunction; and reduced ICU/hospital stay ( TABLE 13-1 ). An additional advantage of VATS is a reduction in infection rate because of decreased exposures in the operating room. Because VATS can be performed in the prone position, circumferential spinal fusion can be done without the need to flip the patient. This carries the added advantage of less operative time and can lead to decreased overall health care costs.