Unilateral Minimally Invasive Across-Midline Vertebral Column Resection Partially Corrects Thoracolumbar Kyphosis - A Case Series

OBJECTIVE

The goal of this study was to describe the indirect and partial correction of spine kyphotic deformities (secondary to various pathologies) achieved by minimally invasive posterolateral extracavitary approach (MIS PLECA) for corpectomy.

METHODS

The authors retrospectively reviewed a consecutive case series of 12 patients undergoing MIS PLECA in a single institution. Perioperative data were collected and follow-up computed tomographies and radiographs were reviewed to assess for interbody arthrodesis.

RESULTS

The mean age was 60.7 ± 20.8 years (58.4% males). The etiologies of deformity included pathological fracture (41.6%), acute trauma (30%), and infection. An expandable cage was used in 66.7% of patients for anterior reconstruction. The mean total estimated blood loss was 764.1 ± 332.9 ml. The mean operative time was 413.3 ± 98.8 minutes. The average length of hospital stay was 5.8 ± 2.5 days. A consistent degree of focal correction of sagittal alignment was seen in all patients with a mean correction of sagittal angle of 7.4 ± 4.3° (P < 0.0001). The mean duration of rehabilitation was 8.5 ± 6.7 days. All patients remained neurologically stable at the last follow-up with a mean follow-up period of 20.1 ± 12.8 months. Successful fusion was achieved in 91.7% at the last follow-up.

CONCLUSIONS

MIS PLECA for corpectomy appears to be a feasible, safe, and effective MIS technique for select patients, particularly those who cannot tolerate the traditional open approach. Additionally, a focal sagittal deformity correction can be achieved using MIS corpectomy.

Costotransversectomy in the Surgical Treatment of Mediolateral Thoracic Disk Herniations: Long-Term Results and Recent Minimally Invasive Technical Adjuncts

Thoracic herniated disks are relatively rare. They account for approximately 2% of all intervertebral herniated disks in large series. Traditional surgery via laminectomy has frequently yielded disappointing results, although the recent literature reports that anterior calcified thoracic herniation was successfully treated with this approach. This issue has encouraged a search for alternatives, such as anterolateral, lateral, and posterolateral approaches to the thoracic spine. From January 2009 to December 2019, we selected 66 patients harboring a symptomatic median-paramedian herniated disk at the level of the thoracic spine, treated at the authors' institutions. The present experience would give further support to the use of costotrasversectomy, along with its "mini-invasive" modifications, as a suitable and safe approach for thoracic disk disease. Although we must admit that endoscopy is likely to become the gold standard of surgical method in the future and that the anterior approach with mini-toracotomy without rib removal will become popular, the future scenario could certainly reserve an important place for the approach we have used in the surgical management of this challenging spinal pathology, mainly because of the approach's versatility and short learning curve.

Anatomical method for rib disconnection during posterior costotransversectomy for paravertebral access to the ventral thoracic spine

Posterior surgical approaches to the thoracic spine are commonly used for degenerative diseases, tumors, trauma, and other operative indications. A posterior approach for access to the paravertebral space is advantageous because it allows for resection of the vertebral body without violating the pleural cavity. Posterior costotransversectomy (PCT) is widely used for this purpose. It involves resection of the rib head after the ligamentous complexes have been disconnected from the transverse process and lateral vertebral body. The current literature provides only vague descriptions of the steps involved in rib disconnection with respect to PCT. A comprehensive knowledge of the anatomical relationships of the ligamentous and soft tissue complexes connecting the rib to the vertebral body is paramount for completing an efficient and safe surgery. This manuscript describes an anatomically directed method for rib disconnection during costotransvrersectomy.

Incidence and degrees of neurologic decline following thoracic costotransversectomy

BACKGROUND CONTEXT

Thoracic costotransversectomies (TCT) are amongst the most invasive spine procedures performed. Of greatest concern to the patient and surgeon is the risk of iatrogenic neurologic injury associated with these procedures. Most available studies limit their assessment of neurologic function to nonspecific scales such as the broader ASIA scoring system of A to E and have not comprehensively described the rates of iatrogenic injury following these procedures by looking more precisely with ASIA motor scoring (0-100) which allows for more in-depth analysis.

PURPOSE

The purpose of this study is to investigate the rates and degree of iatrogenic neurologic decline following TCT and subsequent rates and degree of motor recovery.

STUDY DESIGN/SETTING

Retrospective medical record review at a single institution.

PATIENT SAMPLE

Around 116 consecutive patients undergoing TCT operations.

OUTCOME MEASURES

Neurological changes from preprocedure to final follow-up assessed by lower extremity motor score.

METHODS

A retrospective chart review of patients undergoing TCT between May 2008 and April 2018 was carried out. Clinical, surgical, and intraoperative neuromonitoring data were collected. Patients who demonstrated an initial postoperative decline in lower extremity motor scores (LEMS) were followed through their final follow up to assess recovery.

RESULTS

Around 116 patients underwent TCT between T2 and T12 between May 2008 and April 2018. Seven (6.0%) patients demonstrated an immediate postoperative decline as defined by a drop of more than 4 points (mean 15.1; range 5-50) in motor score. All patients who demonstrated an initial postoperative motor score decline returned to within 4 LEMS points of their preoperative LEMS by final follow up. IOMN changes were noted only in half of all monitored patients who were noted to have a decline.

CONCLUSIONS

In our series, 6.0% of patients undergoing TCT experienced an initial decline in motor score with 94.0% demonstrating an unchanged or improved examination compared to preoperative exam. In our series, all patients who exhibited a decline recovered to within 4 points of the preoperative motor score within the first year postoperatively.

Combined, Rib-Sparing, Bilateral Approach to the Ventral Mid and Low Thoracic Spine: Study on Comparative Anatomy and Surgical Feasibility

BACKGROUND

Pathologies of the ventral thoracic spine represent a challenge, igniting arguments about which should be the ideal surgical approach to access this area. Anterior transthoracic thoracotomy and a number of posterolateral routes have been developed. Among the latter, costotransversectomy has demonstrated to provide good ventral exposure with a lower, but not negligible, morbidity. The optimal approach should be the one minimizing surgical morbidity on both neural and extraneural structures while optimizing exposure.

METHODS

The authors described the combined, rib-sparing, bilateral approach (CRBA) to the ventral mid/low-thoracic spine. The technique combines a transfacet pedicle partially sparing approach on one side and a transpedicular with transverse process resection on the contralateral one. A laboratory investigation was conducted. The technique was applied in a surgical setting, and a case was reported.

RESULTS

CRBA is rib-sparing, completely extracavitary, and does not require pleural exposure and paraspinal muscle splitting, thus minimizing potential morbidity. The combination of 2 corridors ensures the greatest exposure compared with standard posterolateral approaches. The only blind corner is limited to a small area just in front of the dural sac. A bimanual approach optimizes control during surgical manipulation, even if the area of maneuverability and cross-section areas of surgical corridors are slightly limited compared to traditional costotransversectomy due to the minimally invasive nature of the procedure.

CONCLUSIONS

CRBA represents a safe and effective option to access the ventral mid/low thoracic spine. It provides great exposure and bimanual manipulation of the surgical target, minimizes potential morbidity, and avoids entrance into the thoracic cavity and paraspinal muscle splitting.

Costotransversectomy plus hemilaminectomy as alternative surgical approach for extramedullary intradural thoracic schwannoma resection with and without extradural extension in pediatric population three cases and literature review

Extramedullary intradural tumors constitute up to 25% of the spinal tumors. Commonly, schwannomas that presents with extradural and intradural compromise are called dumbbell-shaped tumor. The thoracic spine is a common localization for these tumors, especially in pediatric population. Given this surgically difficult localization, some classic approaches for spine tumors can be mixed with modified approaches like the costotransversectomy. The main objective of this report is expose three different pediatric cases in which mixed approach (costotransversectomy plus hemilaminectomy) was implemented for thoracic spine dumbbell-shaped schwannoma resection. It was achieved complete surgical resection without major perioperative complications in the three cases.

Thoracic corpectomy for neoplastic vertebral bodies using a navigated lateral extracavitary approach-a single-center consecutive case series: technique and analysis

Thoracic myelopathy is often caused by vertebral body fractures resulting from neoplastic conditions, traumatic events, or infectious diseases. One of the preferred procedures for treating it is the lateral extracavitary approach (LECA) with single-level or multilevel decompressive corpectomy and reconstruction. The aim of this retrospective study was to analyze the thoracic lateral extracavitary approach with corpectomy using vertebral body replacement systems (VBR-S) and dorsal reconstruction. Twenty-four patients with metastatic or primary lesions of thoracic vertebrae T2-T12 underwent spinal decompression and ventral column reconstruction with correction of spinal deformity via a LECA. One-level to four-level corpectomies were performed with additional navigated dorsal pedicle screw fixation at an average of two levels above and below the corpectomy lesion. None of the patients received preoperative spinal embolization, and the majority of the patients were admitted to radiotherapy postoperatively. Their mean age was 56 years (± 15), with a female-to-male sex ratio of 8 to 16. Patients with a minimum follow-up period of 16 months were included. The Karnofsky index, preoperative and postoperative numeric rating scale (NRS), and Frankel scale were measured. In addition, intraoperative loss of blood (LOB), units of packed red blood cell (PRBC) transfusions, the duration of the operation, and the hospitalization period were evaluated and correlated with preoperative and postoperative values. The majority of the patients were suffering from metastatic lesions and were treated with a 1 level corpectomy (median 1 level, range 1 to 4). The mean duration of surgery was 288 min (± 121) and the mean LOB was 1626 mL (± 1486 mL), with approximately two PRBC units per patient used. All patients were transferred to the intensive care unit (ICU) postoperatively, with a mean ICU stay of 2.0 days (± 1 day). The mean hospitalization period was 13 days (± 7 days). No implant-related failures or procedure-related deaths were observed. Significant differences were noted between the preoperative and postoperative Karnofsky index (74 vs. 84%) and NRS (4 vs. 2). One patient required revision surgery due to a superficial wound infection, and another needed revision surgery due to a dural tear. In another patient, an iatrogenic dural tear was repaired during the same surgical procedure and did not lead to postoperative complications. Four pleural effusions and one pneumothorax were observed, so that the overall complication rate was approximately 33%. Four of the patients died within 2 years of the operation due to progression of the primary disease. Lateral corpectomy and sagittal reconstruction of the thoracic spine using VBR-S conducted via a navigated LECA approach yields favorable results, despite the burden of neoplastic disease. These challenging procedures are accompanied by increased LOB and hospitalization periods, with moderate transfusion requirements. Surgery-related complications are low and local tumor control is satisfactory, despite the progression of the underlying neoplastic disease. However, optimal surgical therapy does not ensure long-term survival.Study design Retrospective analysis of thoracic corpectomiesLevel of evidence 4.

Surgical Strategy for Spinal Dumbbell Tumors: A New Classification and Surgical Outcomes

STUDY DESIGN

One hundred twenty-four patients with spinal dumbbell tumors were analyzed retrospectively using a new classification.

OBJECTIVE

To recommend a novel classification of spinal dumbbell tumors based on the characteristics of surgical approach.

SUMMARY OF BACKGROUND DATA

Current classifications of cervical dumbbell tumor are excessively convoluted with an impractical number of variables or lack of quantitative indicators for the choice of surgical approach, and there are few classifications described in the literature which related to thoracic or lumbar dumbbell tumors. An ideal classification must be simple and reproducible based on commonly identified clinical and radiographic parameters.

METHODS

The clinical records of a series of 124 patients with spinal dumbbell tumors were analyzed retrospectively using a new classification. We divided the largest transverse section of the tumor into four areas, and different areas need different surgical procedures.

RESULT

Ninety-two patients were treated using the posterior approach alone, 13 patients underwent surgery by lateral cervical approach, and 19 cases were excised using combined anterior and posterior approach. Tumors total removal was 123 cases, with partial resection in one patient. Concomitant spinal fixation and fusion was performed in 18 patients. A total of 97 cases had follow-up with clinical and radiographic outcome variables ranged from 12 to 52 months (mean, 46.3 months). Eighty-eight patients (90.7%) had clinical improvement, whereas clinical status was the same in seven (7.2%), two patients (2.1%) demonstrated neurologic deterioration, and magnetic resonance imaging at last follow-up revealed no recurrence in any patient.

CONCLUSION

The new classification of spinal dumbbell tumors is a simple way of identifying patients who require a different surgical approach.

LEVEL OF EVIDENCE

4.

Novel Bilateral Extracavitary Approach for Thoracolumbar Decompression

BACKGROUND

Bilateral extracavitary approach (BECA) is an option for decompression cases that require a more extended ventral approach. The clear advantage is increased accessibility to the most ventral aspects of the spine from a bilateral perspective.

OBJECTIVE

To assess the safety and efficacy of thoracic and thoracolumbar decompression and/or reconstruction from BECA.

METHODS

A retrospective chart review was performed reviewing all patients who underwent BECA for thoracolumbar decompression from 2003 to 2012 at our institution. We recorded patient baseline characteristics, physical exam, surgical indications, perioperative interventions, and outcomes.

RESULTS

We performed 82 lateral extracavitary approaches and 10 BECAs. BECA indications included neoplasm, infection, and kyphotic deformity. Average patient age was 58 yr; 80% of BECA patients were male. Estimated blood loss was typically 1 to 3 L. Average length of stay postoperative was 12 d. Two patients required revisions; one for infection and one for revision of misplaced hardware. Eight patients improved at least one grade on the American Spinal Injury Association Impairment Scale (ASIA) or was originally ASIA E. Two patients declined 1 to 2 ASIA grades. Average length of follow-up was 16.8 mo.

CONCLUSION

BECA is an efficient technique with acceptable complication rates and similar risks to unilateral approaches. It should be considered when extensive bilateral decompression and/or reconstruction of the anterior thoracic or thoracolumbar spine is required.

The lateral extracavitary approach to the thoracolumbar spine: a case series and systematic review

OBJECT

Since its introduction in 1976, the lateral extracavitary approach (LECA) has been used to access ventral and ventrolateral pathology affecting the thoracolumbar spine. Reporting of outcomes and complications has been inconsistent. A case series and systematic review are presented to summarize the available data.

METHODS

A retrospective review of medical records was performed, which identified 65 consecutive patients who underwent LECA for the treatment of thoracolumbar spine and spinal cord pathology. Cases were divided according to the presenting pathology. Neurological outcomes and complications were detailed. In addition, a systematic review of outcomes and complications in patients treated with the LECA as reported in the literature was completed.

RESULTS

Sixty-five patients underwent the LECA to the spine for the treatment of thoracic spine and spinal cord pathology. The most common indication for surgery was thoracic disc herniation (23/65, 35.4%). Neurological outcomes were excellent: 69.2% improved, 29.2% experienced no change, and 1.5% were worse. Two patients (3.1%) experienced a complication. The systematic review revealed comparable neurological outcomes (74.9% improved) but a notably higher complication rate (32.2%).

CONCLUSIONS

The LECA provides dorsal and unilateral ventrolateral access to and exposure of the thoracolumbar spine and spinal cord while allowing for posterior instrumentation through the same incision. Although excellent neurological results can be expected, the risk of pulmonary complications should be considered.

A quantitative analysis of posterolateral approaches to the ventral thoracic spinal canal

BACKGROUND CONTEXT

Various posterolateral approaches exist to access ventral thoracic spinal canal pathologies. Selecting the optimal surgical approach requires sound understanding of the exposure and working angle afforded by each approach.

PURPOSE

The purpose of this study was to quantify exposure of the ventral spinal canal with various posterolateral thoracic spinal approaches and to determine how regional anatomical differences affect measurements.

STUDY DESIGN

This is a quantitative anatomical cadaveric study.

METHODS

Four fresh cadaveric C7-L1 specimens were used with a saline infusion model to mimic in vivo thecal sac dimensions. Using stereotactic navigation, we measured exposure (expressed as percentage of total width) and maximum approach angle of the ventral spinal canal without thecal sac retraction after each surgical condition: laminectomy (L), 50% medial facetectomy (MF), transpedicular (TP), costotransversectomy (CTV), and lateral extracavitary (LE). The thoracic spine was divided into four regions (T1-T2, T3-T6, T7-T10, and T9-T12). A two-sided paired t test was used.

RESULTS

At T1-T2, visualized exposures were 25.8%, 31.5%, 42.3%, 45.1%, and 46.8%, respectively, after each surgical condition. Costotransversectomy and LE did not provide significant increase in exposure compared with the preceding condition. At T3-T6, exposures were 19.1%, 29.6%, 38.7%, 44.4%, and 44.5%, respectively. Only LE did not provide significant increase in exposure compared with the preceding condition. At T7-T10, visualized exposures were 17.9%, 30.6%, 39.9%, 44.9%, and 53.3%, respectively. All successive surgical conditions provided a significant increase in exposure. At T11-T12, visualized exposures were 14.2%, 25.8%, 43.1%, 47.7%, and 52.7%, respectively. Only LE did not provide a significant increase in exposure compared with the preceding condition. Each successive surgical condition provided a significantly increased lateral approach angle compared with the preceding condition, except LE at T1-T2. Maximum approach angle was more favorable at T1-T2 for L, MF, TP, and CTV compared with other thoracic regions.

CONCLUSIONS

Medial facetectomy and TP approaches provide significantly increased exposure of the ventral spinal canal at all thoracic regions. Costotransversectomy provided significantly increased exposure compared with TP at T3-T12. Lateral extracavitary only provided significantly increased exposure compared with CTV at T7-T10. The results of this study can be used preoperatively to determine the optimal approach based on quantitative measurements and region-specific anatomical differences.

Thoracic lateral extracavitary corpectomy for anterior column reconstruction with expandable and static titanium cages: clinical outcomes and surgical considerations in a consecutive case series

OBJECTIVE

Many surgical interventions have emerged as effective means of restoring mechanical stability of the anterior column of the spine. The lateral extracavitary approach (LECA) allows for broad visualization and circumferential reconstruction of the spinal column. However, early reports demonstrated significant complication rates, protracted operative times, and prolonged hospitalizations. More recent reports have highlighted concerns for subsidence, particularly with expandable cages. Our work seeks to describe a single-surgeon consecutive series of patients undergoing LECA for thoracic corpectomy. Specifically, the objective was to explore the surgical considerations, clinical and radiographic outcomes, and complication profile of this approach.

METHODS

A retrospective study examined data from 17 consecutive patients in whom single or multi-level corpectomy was performed via a LECA by a single surgeon. Vertebral body replacement was achieved with either a static or expandable titanium cage. The Karnofsky Performance Scale (KPS) was utilized to assess patient functional status before and after surgery. Radiographic outcomes, particularly footplate-to-body ratio and subsidence, were assessed on CT imaging at 6 weeks after surgery and at follow-up of at least 6 months.

RESULTS

The majority of patients had post-operative KPS scores consistent with functional independence (≥70, 12/17 patients, 71%). Fourteen patients had improved or maintained function by last follow-up. In both groups, all patients had a favorable footplate-to-body ratio, and rates of subsidence were similar at both time points. Notably, the overall complication rate (24%) was significantly lower than that published in the literature, and no patient suffered a pneumothorax that required placement of a thoracostomy tube.

CONCLUSION

The LECA approach for anterior column reconstruction with static or expandable cages is an important surgical consideration with favorable surgical parameters and complication rates. Further, use of expandable cages may allow for reconstruction over a larger segment without increased risk of subsidence.

Biomechanics of the lower thoracic spine after decompression and fusion: a cadaveric analysis

BACKGROUND CONTEXT

Few studies have evaluated the extent of biomechanical destabilization of thoracic decompression on the upper and lower thoracic spine. The present study evaluates lower thoracic spinal stability after laminectomy, unilateral facetectomy, and unilateral costotransversectomy in thoracic spines with intact sternocostovertebral articulations.

PURPOSE

To assess the biomechanical impact of decompression and fixation procedures on lower thoracic spine stability.

STUDY DESIGN

Biomechanical cadaveric study.

METHODS

Sequential surgical decompression (laminectomy, unilateral facetectomy, unilateral costotransversectomy) and dorsal fixation were performed on the lower thoracic spine (T8-T9) of human cadaveric spine specimens with intact rib cages (n=10). An industrial robot was used to apply pure moments to simulate flexion-extension (FE), lateral bending (LB), and axial rotation (AR) in the intact specimens and after decompression and fixation. Global range of motion (ROM) between T1-T12 and intrinsic ROM between T7-T11 were measured for each specimen.

RESULTS

The decompression procedures caused no statistically significant change in either global or intrinsic ROM compared with the intact state. Instrumentation, however, reduced global motion for AR (45° vs. 30°, p=.0001), FE (24° vs. 19°, p=.02), and LB (47° vs. 36°, p=.0001) and for intrinsic motion for AR (17° vs. 4°, p=.0001), FE (8° vs. 1°, p=.0001), and LB (12° vs. 1°, p=.0001). No significant differences were identified between decompression of the upper versus lower thoracic spine, with trends toward significantly greater ROM for AR and lower ROM for LB in the lower thoracic spine.

CONCLUSIONS

The lower thoracic spine was not destabilized by sequential unilateral decompression procedures. Addition of dorsal fixation increased segment rigidity at intrinsic levels and also reduced overall ROM of the lower thoracic spine to a greater extent than did fusing the upper thoracic spine (level of the true ribs). Despite the lack of true ribs, the lower thoracic spine was not significantly different compared with the upper thoracic spine in FE and LB after decompression, although there were trends toward significance for greater AR after decompression. In certain patients, instrumentation may not be needed after unilateral decompression of the lower thoracic spine; further validation and additional clinical studies are warranted.