Endoscopic surgery on the thoracolumbar junction of the spine

The Role and Future of Endoscopic Spine Surgery: A Narrative Review

Many types of surgeries are changing from conventional to minimally invasive techniques. Techniques in spine surgery have also changed, with endoscopic spine surgery (ESS) becoming a major surgical technique. Although ESS has advantages such as less soft tissue dissection and normal structure damage, reduced blood loss, less epidural scarring, reduced hospital stay, and earlier functional recovery, it is not possible to replace all spine surgery techniques with ESS. ESS was first used for discectomy in the lumbar spine, but the range of ESS has expanded to cover the entire spine, including the cervical and thoracic spine. With improvements in ESS instruments (optics, endoscope, endoscopic drill and shaver, irrigation pump, and multiportal endoscopic), limitations of ESS have gradually decreased, and it is possible to apply ESS to more spine pathologies. ESS currently incorporates new technologies, such as navigation, augmented and virtual reality, robotics, and 3-dimentional and ultraresolution visualization, to innovate and improve outcomes. In this article, we review the history and current status of ESS, and discuss future goals and possibilities for ESS through comparisons with conventional surgical techniques.

Video-Assisted Thoracoscopic Surgery for Re-Collapse of Vertebrae after Percutaneous Vertebral Augmentation (PVA)

INTRODUCTION

Due to the increase in osteoporosis accompanying the aging society in Japan, osteoporotic vertebral fractures (OVFs) are increasing. Percutaneous vertebral augmentation (PVA) has been widely used for OVFs because it reduces pain immediately with less invasiveness. Re-collapse of vertebral body after PVA is a rare, but important, complication. Once the re-collapse has occurred, patients should undergo an additional invasive salvage surgery.

METHODS

We treated 5 patients with re-collapse after PVA in our hospital. For re-collapse after PVA, we performed anterior column reconstruction with video-assisted thoracoscopic surgery (VATS), posterior fixation with percutaneous pedicle screws (PPSs) and minimally invasive spine stabilization (MISt).

RESULTS

The mean postoperative follow-up was at 62.8 months. At the final follow-up, the patients were free of low back pain, and bony union was achieved in all cases. The postoperative correction loss was 6 degrees. Perioperative complications included aspiration pneumonia in one patient and bone fracture of an adjacent vertebral body in two patients. There were no reoperation cases.

CONCLUSIONS

We perform minimally invasive combined anterior and posterior surgery with VATS for re-collapse after PVA. This procedure is useful in elderly patients with less reserve capacity.

Retroperitoneal Extrapleural Approach for Corpectomy of the First Lumbar Vertebra : Technique and Outcome

Objective

Corpectomy of the first lumbar vertebra (L1) for the management of different L1 pathologies can be performed using either an anterior or posterior approach. The aim of this study was to evaluate the usefulness of a retroperitoneal extrapleural approach through the twelfth rib for performing L1 corpectomy.

Methods

Thirty consecutive patients underwent L1 corpectomy between 2010 and 2016. The retroperitoneal extrapleural approach through the 12th rib was used in all cases to perform single-stage anterior L1 corpectomy, reconstruction and anterior instrumentation, except for in two recurrent cases in which posterior fixation was added. Visual analogue scale (VAS) was used for pain intensity measurement and ASIA impairment scale for neurological assessment. The mean follow-up period was 14.5 months.

Results

The sample included 18 males and 12 females, and the mean age was 40.3 years. Twenty patients (67%) had sensory or motor deficits before the surgery. The pathologies encountered included traumatic fracture in 12 cases, osteoporotic fracture in four cases, tumor in eight cases and spinal infection in the remaining six cases. The surgeries were performed from the left side, except in two cases. There was significant improvement of back pain and radicular pain as recorded by VAS. One patient exhibited postoperative neurological deterioration due to bone graft dislodgement. All patients with deficits at least partially improved after the surgery. During the follow-up, no hardware failures or losses of correction were detected.

Conclusion

The retroperitoneal extrapleural approach through the 12th rib is a feasible approach for L1 corpectomy that can combine adequate decompression of the dural sac with effective biomechanical restoration of the compromised anterior load-bearing column. It is associated with less pulmonary complication, no need for chest tube, no abdominal distention and rapid recovery compared with other approaches.

Minimally Invasive Endoscopic Approach to the Cervicothoracic Junction for Vertebral Osteomyelitis

The selection of an anterior, lateral, or posterior approach to the cervicothoracic junction for surgical treatment of vertebral osteomyelitis is still a matter of debate. These ordinary approaches generally require an extensile exposure. This article describes a less invasive approach case of a vertebral osteomyelitis of T2/3 using a video-assisted operating technique of thoracic surgery (VATS). A 78-year-old female underwent anterior debridement and interbody fusion with bone graft at T2/3 using a lateral surgical approach through a right thoracotomy with VATS. The VATS through two small skin incisions in the axillary region provides a good view without requiring elevation of the scapula with extensile muscle dissection and rib resection. There was no complication without partial lobectomy due to pleural adhesion during the perioperative period. Currently, at 1 year after operation, the patient has no back pain with neurologically normal findings and no inflammation findings (CRP was 0.01 mg/dl). Although the operating field of the upper thoracic level in the lateral approach is generally deep and narrow, the VATS provides a good view and allows us to perform adequate debridement and bone fusion at the T2/3 level with a less invasive approach than those previously described anterior or laterally or posterior approach.

Safety and Efficacy of Single-Stage versus 2-Stage Spinal Fusion via Posterior Instrumentation and Anterior Thoracoscopy: A Retrospective Matched-Pair Cohort Study with 247 Consecutive Patients

OBJECTIVE

Posterior-anterior spondylodesis is often used to stabilize the spine in various pathologies. The anterior procedure is often performed via thoracoscopy. It is unclear whether the anterior procedure should be performed immediately after posterior instrumentation or after the patient has convalesced. This retrospective study compared perioperative safety and morbidity in 1-stage versus 2-stage posterior-anterior fusion surgery with a thoracoscopic anterior approach.

METHODS

All consecutive patients who underwent surgery for posterior-anterior spinal stabilization from 2006 to 2013 were included. American Society of Anesthesiologists score, preoperative and postoperative laboratory values, operation duration, blood loss, intensive care unit stay, pain, postoperative hospital stay, perioperative complications, and preoperative and postoperative Eastern Cooperative Oncology Group and Frankel scores were assessed. A subset of the cohort was selected by propensity score matching to eliminate possible selection bias.

RESULTS

There were 247 patients who underwent 1-stage (n = 104) or 2-stage (n = 143) stabilization with thoracoscopic fusion. Spinal pathologies were fracture, malignancy, pyogenic spondylodiscitis, degenerative spinal disorders, and failed previous surgery. One-stage and 2-stage procedures were similar in terms of preoperative, surgical, and postoperative variables, including complication rates, except that the 1-stage procedure was associated with greater pain 2 days after surgery and shorter hospital stay. The propensity score-matched cohort of 64 pairs yielded similar results with only 1-stage patients showing elevated visual analog scale score on postoperative day 2 (3.8 vs. 2.4, P = 0.043).

CONCLUSIONS

One-stage stabilization was as safe as 2-stage stabilization and associated with shorter hospitalization. Greater pain after the 1-stage procedure, which resolved 30 days after surgery, reflects the fact that 2-stage patients already had pain relief when they underwent thoracoscopy.

The Role of a Miniopen Thoracoscopic-assisted Approach in the Management of Burst Fractures Involving the Thoracolumbar Junction

Thoracoscopic spinal surgery is a minimally invasive open endoscopic approach to the anterior thoracolumbar spine for decompression and stabilization. It offers an alternative to open thoracotomy for thoracolumbar burst fractures, anterior spinal cord decompression, and spinal reconstruction with interbody and anterolateral plate instrumentation for restoration of biomechanical stability and alignment. Posterior instrumentation may not sufficiently stabilize a significantly disrupted anterior load-bearing spinal column, and the high access morbidity of open procedures is of significant concern. The adoption by spine surgeons of minimally invasive thoracoscopic techniques used by thoracic surgeons has expanded to include treatment of most anterior thoracolumbar disorders.

History of Retractor Technologies for Percutaneous Pedicle Screw Fixation Systems

Minimally invasive techniques aimed at minimizing surgery-associated risk and morbidity of spinal surgery have increased in popularity in recent years. Their potential advantages include reduced length of hospital stay, blood loss, and requirement for post-operative analgesia and earlier return to work. One such minimally invasive technique is the use of percutaneous pedicle screw fixation, which is paramount for promoting rigid and stable constructs and fusion in the context of trauma, tumors, deformity and degenerative disease. Percutaneous pedicle screw insertion can be an intimidating prospect for surgeons who have only been trained in open techniques. One of the ongoing challenges of this percutaneous system is to provide the surgeon with adequate access to the pedicle entry anatomy and adequate tactile or visual feedback concerning the position and anatomy of the rod and set-screw construct. This review article discusses the history and evolution of percutaneous pedicle screw retractor technologies and outlines the advances over the last decade in the rapidly expanding field of minimal access surgery for posterior pedicle screw based spinal stabilization. As indications for percutaneous pedicle screw techniques expand, the nuances of the minimally invasive surgery techniques and associated technologies will also multiply. It is important that experienced surgeons have access to tools that can improve access with a greater degree of ease, simplicity and safety. We here discuss the technical challenges of percutaneous pedicle screw retractor technologies and a variety of systems with a focus on the pros and cons of various retractor systems.

Management of thoracolumbar spine trauma: An overview

Thoracolumbar spine fractures are common injuries that can result in significant disability, deformity and neurological deficit. Controversies exist regarding the appropriate radiological investigations, the indications for surgical management and the timing, approach and type of surgery. This review provides an overview of the epidemiology, biomechanical principles, radiological and clinical evaluation, classification and management principles. Literature review of all relevant articles published in PubMed covering thoracolumbar spine fractures with or without neurologic deficit was performed. The search terms used were thoracolumbar, thoracic, lumbar, fracture, trauma and management. All relevant articles and abstracts covering thoracolumbar spine fractures with and without neurologic deficit were reviewed. Biomechanically the thoracolumbar spine is predisposed to a higher incidence of spinal injuries. Computed tomography provides adequate bony detail for assessing spinal stability while magnetic resonance imaging shows injuries to soft tissues (posterior ligamentous complex [PLC]) and neurological structures. Different classification systems exist and the most recent is the AO spine knowledge forum classification of thoracolumbar trauma. Treatment includes both nonoperative and operative methods and selected based on the degree of bony injury, neurological involvement, presence of associated injuries and the integrity of the PLC. Significant advances in imaging have helped in the better understanding of thoracolumbar fractures, including information on canal morphology and injury to soft tissue structures. The ideal classification that is simple, comprehensive and guides management is still elusive. Involvement of three columns, progressive neurological deficit, significant kyphosis and canal compromise with neurological deficit are accepted indications for surgical stabilization through anterior, posterior or combined approaches.

Thoracolumbar spine trauma: Evaluation and surgical decision-making

Introduction:

Thoracolumbar spine trauma is the most common site of spinal cord injury, with clinical and epidemiological importance.

Materials and Methods:

We performed a comprehensive literature review on the management and treatment of TLST.

Results:

Currently, computed tomography is frequently used as the primary diagnostic test in TLST, with magnetic resonance imaging used in addition to assess disc, ligamentous, and neurological injury. The Thoracolumbar Injury Classification System is a new injury severity score created to help the decision-making process between conservative versus surgical treatment. When decision for surgery is made, early procedures are feasible, safe, can improve outcomes, and reduce healthcare costs. Surgical treatment is individualized based on the injury characteristics and surgeon's experience, as there is no evidence-based for the superiority of one technique over the other.

Conclusions:

The correct management of TLST involves multiple steps, such as a precise diagnosis, classification, and treatment. The TLICS can improve care and communication between spine surgeons, resulting in a more standardized treatment.

The direct anterior approach to the thoracolumbar junction: an anatomical feasibility study

INTRODUCTION

The thoracolumbar junction (TJ) is traditionally exposed by lateral or posterior approaches. This usually requires splitting of the diaphragm, or extensile removal of the posterior elements. A circumferential exposure (i.e. simultaneous anterior and bilateral exposure) of the vertebral body is not possible. Direct anterior access would allow circumferential exposure of the vertebral body, with adjacent disc levels, and would avoid splitting the diaphragm or extensive removal of the posterior bony structures.

MATERIALS AND METHODS

Twelve Thiel cadavers (8 f/4 m) were dissected to access T12 or L1 via a midline laparotomy. Supra- and infragastric laparatomy techniques were investigated. Six cadavers were used to reach T12 through the lesser omentum, six to reach L1 through the greater omentum.

RESULTS

T12 after bluntly dissecting the lesser omentum, the lesser gastric curvature and the caudate lobe of the liver were utilised as landmarks. A small retroperitoneal incision was performed to mobilise the aorta allowing exposure of the T12 vertebra and its adjacent discs. Discectomy, corpectomy and insertion of an anterior column support were possible. The L1 level can be reached through the greater omentum by mobilising the pancreas as a single retroperitoneal structure, leaving the aorta and celiac trunk as landmarks. Retraction of the great vessels is necessary to expose L1 with its adjacent discs. Implantation of an anterior column support was possible utilising this approach.

CONCLUSION

Direct anterior access to the TJ is feasible in a reproducible manner. This approach would avoid splitting the diaphragm, or dissection of the erector spinae muscles, and is likely to be less invasive than standard lateral or posterior approaches. This technique may offer a significant time reduction to surgery, especially in exposing the spine. Anterior column support can easily be performed, offering a better avoidance of kyphotic deformities.

Subphrenic hematoma after thoracoscopic discectomy: description of a very rare adverse event and review of the literature on complications

The authors describe a very rare and previously unreported complication of thoracoscopic discectomy. Endoscopic spine surgery has evolved as a safe and effective treatment, and thoracoscopic discectomy, in particular, provides several advantages over open approaches, although it can be associated with intraoperative or postoperative complications. The most frequently observed adverse events are intercostal neuralgia, retained disc fragments, durotomies, atelectasis, extensive bleeding, and emergency conversion to open thoracotomy for vascular injuries. Even rare complications, such as chylorrhea or brain hemorrhagic infarction, have been reported. Nonetheless, a literature review did not reveal any case of postoperative intraabdominal hematoma following thoracoscopic discectomy. A 43-year-old woman, with no history of hematological or vascular disorders or thoracic surgery, underwent a right-sided thoracoscopic discectomy for T11–12 disc herniation. No apparent surgical technique–related complications were encountered, but intermittently repeated difficulties with single-lung ventilation occurred. The resultant dysventilation allowed partial right lung reexpansion, along with increased abdominal pressure. The latter induced an upward ballooning of the right diaphragm with consequent obstruction of the surgical field of view, requiring constant and continuous pressure applied to the thoracic surface of the diaphragm via a metal fan retractor and thus counteracting the increased abdominal pressure. Postoperatively, a large subdiaphragmatic hematoma originating from a bleeding right inferior phrenic artery was diagnosed and required urgent endovascular occlusion. The patient made an uneventful recovery with conservative treatment. A very rare and previously unreported complication—that is, early subdiaphragmatic hematoma after thoracoscopic discectomy—is described here. The authors submit that conversion to an open approach is safer when persistent anesthesia-related complications are encountered in thoracoscopic discectomy.

Compression and contact area of anterior strut grafts in spinal instrumentation: a biomechanical study

Background

Anterior bone grafts are used as struts to reconstruct the anterior column of the spine in kyphosis or following injury. An incomplete fusion can lead to later correction losses and compromise further healing. Despite the different stabilizing techniques that have evolved, from posterior or anterior fixating implants to combined anterior/posterior instrumentation, graft pseudarthrosis rates remain an important concern. Furthermore, the need for additional anterior implant fixation is still controversial. In this bench-top study, we focused on the graft-bone interface under various conditions, using two simulated spinal injury models and common surgical fixation techniques to investigate the effect of implant-mediated compression and contact on the anterior graft.

Methods

Calf spines were stabilised with posterior internal fixators. The wooden blocks as substitutes for strut grafts were impacted using a “pressfit” technique and pressure-sensitive films placed at the interface between the vertebral bone and the graft to record the compression force and the contact area with various stabilization techniques. Compression was achieved either with posterior internal fixator alone or with an additional anterior implant. The importance of concomitant ligament damage was also considered using two simulated injury models: pure compression Magerl/AO fracture type A or rotation/translation fracture type C models.

Results

In type A injury models, 1 mm-oversized grafts for impaction grafting provided good compression and fair contact areas that were both markedly increased by the use of additional compressing anterior rods or by shortening the posterior fixator construct. Anterior instrumentation by itself had similar effects. For type C injuries, dramatic differences were observed between the techniques, as there was a net decrease in compression and an inadequate contact on the graft occurred in this model. Under these circumstances, both compression and the contact area on graft could only be maintained at high levels with the use of additional anterior rods.

Conclusions

Under experimental conditions, we observed that ligamentous injury following type C fracture has a negative influence on the compression and contact area of anterior interbody bone grafts when only an internal fixator is used for stabilization. Because of the loss of tension banding effects in type C injuries, an additional anterior compressing implant can be beneficial to restore both compression to and contact on the strut graft.

Advances made in the treatment of thoracolumbar fractures: current trends and future directions

Thoracolumbar fractures are common injuries after blunt trauma and are accompanied with significant morbidity, including neurologic deficit. Parallel to the evolution of initial management during the past few years, efforts have been concentrated on determining clear indications for surgical treatment, as there is no agreement over superiority of conservative or operative treatment. Various classification systems have been used for identifying those injuries requiring surgical intervention. Moreover, novel trends in surgical techniques, including minimal invasive surgery, implants and rehabilitation protocols have provided new, promising aspects regarding the treatment and outcomes of thoracolumbar fractures. The present review focuses on these recent advances.

[Current status of thoracoscopic surgery for thoracic and lumbar spine. Part 1: general aspects and treatment of fractures]

INTRODUCTION

Thoracoscopic surgery or video-assisted thoracic surgery (VATS) of the thoracic and lumbar spine has greatly evolved since it appeared less than 20 years ago. Nowadays, it is indicated in a large number of processes and injuries. The aim of this article, in its 2 parts, is to review the current status of VATS in treatment of the thoracic and lumbar spine in its entire spectrum.

DEVELOPMENT

After reviewing the current literature, we develop each of the large groups of indications where VATS is used, one by one. This first part contains a description of general thoracoscopic surgical technique including the necessary prerequisites, transdiaphragmatic approach, techniques and instrumentation used in spine reconstruction, as well as a review of treatment and specific techniques in the management of spinal fractures.

CONCLUSIONS

Thoracoscopic surgery is in many cases an alternative to conventional open surgery. The transdiaphragmatic approach has made endoscopic treatment of many thoracolumbar junction processes possible, thus widening the spectrum of therapeutic indications. These include the treatment of fractures and deformities, as well as the reconstruction of injured spinal segments and decompression of the spinal canal in any etiological processes if the lesion placement is favourable to antero-lateral approach. Good clinical results of thoracoscopic surgery are supported by the growing experience reflected in a large number of articles. The degree of complications in thoracoscopic surgery is comparable to open surgery, with benefits in morbidity of the approach and subsequent patient recovery.

Comparison of mini-open anterior corpectomy and posterior total en bloc spondylectomy for solitary metastases of the thoracolumbar spine

Object

The object of this study was to compare the mini-open anterior corpectomy procedure with posterior total en bloc spondylectomy (TES) in treating patients with solitary metastases of the thoracolumbar spine.

Methods

From 2004 to 2010, 41 patients with solitary metastases of the thoracolumbar spine were treated in our hospital using either a mini-open anterior corpectomy or posterior TES. Intraoperative and diagnostic data, including perioperative complications, were collected using retrospective chart review. The surgical outcomes were assessed according to survival status, neurological function, local recurrence, and pain before and after surgery.

Results

Seventeen patients underwent posterior TES and 24 underwent mini-open anterior corpectomy. Mean blood loss (TES, 1721 ± 293 ml; mini-open corpectomy, 1058 ± 263 ml; p < 0.05), and mean operative time (TES, 403 ± 55 minutes; mini-open corpectomy, 175 ± 38 minutes; p < 0.05) were recorded and calculated. Neurological improvement by at least 1 American Spinal Injury Association Impairment Scale grade was noted in 35 (97.2%) of the 36 cases with preoperative deficits. After the operation, 68.4% of nonambulatory patients became ambulatory again, including 84.6% after mini-open corpectomy and 33.3% after posterior TES (p > 0.05). The visual analog scale scores of the patients were significantly reduced after both procedures, with no difference between the procedures (p > 0.05). The local tumor recurrence rate of the TES group was significantly lower than that of the mini-open corpectomy group (p < 0.05), while the postoperative survival rates within 2 years after surgery were similar. The complication rate in the mini-open corpectomy group (29.2%) was higher than that in the TES group (11.8%), but this difference was not statistically significant (p = 0.185). There was no hardware failure and no loss of the sagittal Cobb angle in either group. Slight subsidence (< 3 mm) of the mesh cage was observed with a successful fusion in 3 (17.6%) of 17 patients in the TES group. No subsidence of polymethylmethacrylate block/autograft was recorded in the mini-open group.

Conclusions

Mini-open anterior corpectomy can be accomplished with less blood loss, fewer fixation instrumentations, and shorter surgical time than that required for TES, but patients who undergo a mini-open corpectomy might have a greater tendency to experience local recurrence. A mini-open anterior corpectomy has a relatively mild learning curve and involves fewer technical difficulties. With smaller incisions, mini-open anterior corpectomy is an option in treating solitary metastases of the thoracolumbar spine.

Impact of magnetic resonance imaging on decision making for thoracolumbar traumatic fracture diagnosis and treatment

INTRODUCTION

The role of magnetic resonance imaging (MRI) has recently been enhanced in the diagnosis of thoracolumbar fractures due to its ability to examine soft tissue injury.

MATERIAL AND METHODS

We conducted a prospective study to analyze the usefulness of MRI in fracture diagnosis and its influence on treatment decision making. Thirty-three patients were enrolled after suffering an acute traumatic thoracolumbar fracture. Osteoporotic or pathologic fractures were excluded. Fractures were initially classified using X-ray and CT scan following the AO classification. Afterward, a selective MRI protocol was performed with T1 and T2-weighted FS/STIR sequences. Subsequently, fractures were classified according to the TLICS system and reclassified following the AO system. Analysis was performed before and after MRI, focusing on: diagnostic changes, occult fractures and differences in treatment decision making.

RESULTS

Thirty patients (15 males, 15 females) with an average age of 39.9 years were studied. Forty-one fractures were initially diagnosed using plain X-rays and CT scans, while MRI diagnosed 50 fractures and 9 vertebral contusions. MRI modified our diagnosis in 40% of our patients (discovering 18 occult injuries), the classification of fracture pattern in 24% of the fractures (mostly upgrading type A to type B patterns) and the therapeutic management in 16% of our patients.

CONCLUSIONS

MRI seems to be a useful tool in the evaluation of thoracolumbar acute fractures, as it allows a better visualization of the posterior complex integrity and of the levels involved, offering additional information compared to traditional diagnostic tools.

[Reconstruction after spinal fractures in the thoracolumbar region]

The morbidity of anterior approaches has significantly influenced the development of therapeutic concepts for the treatment of thoracolumbar spine fractures. Minimally-invasive techniques such as mini-open and endoscopic have enlarged the numbers of anterior reconstruction after spinal fractures in the thoracolumbar region. These minimally-invasive approaches have been facilitated by the development of special implants adapted to the new technique and to the local anatomical requirements.Two multi center studies in Germany (MCSI and II) showed the trend towards minimal invasive procedures and anterior approaches in the German speaking spine centers. Since the first report on thoracoscopic anterior procedures in Germany in 1997 a growing number of spine centers established this method. There is still no evidence based high level literature to substantiate a significant benefit for the patients by anatomical reduction and reconstruction of the anterior spinal column. However, there are some reports on better short outcomes in radiological parameters as well as better clinical results in 5 to 8 year follow-ups.The minimal invasive anterior approach seems to be advantageous for the patients by reducing significantly additive operation morbidity. It has become more important over the last two decades for anterior reconstruction after trauma and posttraumatic malalignment of the thoracolumbar spine.

Thoracoscopic assisted en bloc resection of a spine tumor

Spine tumors are fairly common and the management is through a multimodality approach. Lesions of the thoracic and lumbar vertebrae have been treated with such extensive anterior and/or posterior approaches. The authors present a case of a 56-year-old lady with solitary T11 metastases from colonic carcinoma and a case of a 43-year-old lady with T5-T6 high-grade osteogenic sarcoma. The treatment consists of a wide vertebrectomy by posterior approach, after anterior release and sub-pleural dissection using a thoracoscopic approach. A thoracoscopic assisted anterior approach could reduce the duration and the morbidity of a vertebrectomy without affecting oncological management.