Oblique paraspinal approach for thoracic disc herniations using tubular retractor with robotic holder: a technical note

Endoscopic Versus Traditional Thoracic Discectomy: A Multicenter Retrospective Case Series and Meta-Analysis

BACKGROUND AND OBJECTIVES

Surgical treatment for symptomatic thoracic disc herniations (TDH) involves invasive open surgical approaches with relatively high complication rates and prolonged hospital stays. Although advantages of full endoscopic spine surgery (FESS) are well-established in lumbar disc herniations, data are limited for the endoscopic treatment of TDH despite potential benefits regarding surgical invasiveness. The aim of this study was to provide a comprehensive evaluation of potential benefits of FESS for the treatment of TDH.

METHODS

PubMed, MEDLINE, EMBASE, and Scopus were systematically searched for the term "thoracic disc herniation" up to March 2023 and study quality appraised with a subsequent meta-analysis. Primary outcomes were perioperative complications, need for instrumentation, and reoperations. Simultaneously, we performed a multicenter retrospective evaluation of outcomes in patients undergoing full endoscopic thoracic discectomy.

RESULTS

We identified 3190 patients from 108 studies for the traditional thoracic discectomy meta-analysis. Pooled incidence rates of complications were 25% (95% CI 0.22-0.29) for perioperative complications and 7% (95% CI 0.05-0.09) for reoperation. In this cohort, 37% (95% CI 0.26-0.49) of patients underwent instrumentation. The pooled mean for estimated blood loss for traditional approaches was 570 mL (95% CI 477.3-664.1) and 7.0 days (95% CI 5.91-8.14) for length of stay. For FESS, 41 patients from multiple institutions were retrospectively reviewed, perioperative complications were reported in 4 patients (9.7%), 4 (9.7%) required revision surgery, and 6 (14.6%) required instrumentation. Median blood loss was 5 mL (IQR 5-10), and length of stay was 0.43 days (IQR 0-1.23).

CONCLUSION

The results suggest that full endoscopic thoracic discectomy is a safe and effective treatment option for patients with symptomatic TDH. When compared with open surgical approaches, FESS dramatically diminishes invasiveness, the rate of complications, and need for prolonged hospitalizations. Full endoscopic spine surgery has the capacity to alter the standard of care for TDH treatment toward an elective outpatient surgery.

A narrative review of endoscopic spine surgery: history, indications, uses, and future directions

Background and Objective

The concept of endoscopic surgery began in the 1930s and has since undergone numerous advancements in both technology and surgical indications. Its main benefit is providing the opportunity to perform surgery while minimizing disruption to surrounding structures. The purpose of this review is to summarize the history, uses, and future directions for spine endoscopic surgery.

Methods

A review of national databases was performing using key terms "endoscopic", "spine" and "surgery" for literature from 1900 to 2023. Studies that aimed to describe the utilities of endoscopic surgeries, associated outcomes, limitations, and future directions were included. Studies that were not in English were excluded.

Key Content and Findings

This review includes a brief overview of the history of endoscopic surgery and its current two main approaches, transforaminal and interlaminar approaches. It then summarizes the main indications and utilization of endoscopic surgery in the lumbar, cervical and thoracic spine, as well as expansion in managing spine tumors, infections, and outpatient surgical cases.

Conclusions

There are many rising indications and uses for endoscopic spine surgery in nearly every aspect of the spine. Compared to conventional spine surgery, there is early evidence showing endoscopic surgery is associated with less post-operative pain, shorter hospital stays, and possibly quicker recovery times. As current trends in spine surgery move towards minimally invasive techniques, it is anticipated that the use of endoscopic surgery will continue to expand.

Evolution, Current Trends, and Latest Advances of Endoscopic Spine Surgery

Background: The aging of the population in developing and developed countries has led to a significant increase in the health burden of spinal diseases. These elderly patients often have a number of medical comorbidities due to aging. The need for minimally invasive techniques to address spinal disorders in this elderly population group cannot be stressed enough. Minimally invasive spine surgery (MISS) has several proven benefits, such as minimal muscle trauma, minimal bony resection, lesser postoperative pain, decreased infection rate, and shorter hospital stay. Methods: A comprehensive search of the literature was performed using PubMed. Results: Over the past 40 years, constant efforts have been made to develop newer techniques of spine surgery. Endoscopic spine surgery is one such subset of MISS, which has all the benefits of modern MISS. Endoscopic spine surgery was initially limited only to the treatment of lumbar disc herniation. With improvements in optics, endoscopes, endoscopic drills and shavers, and irrigation pumps, there has been a paradigm shift. Endoscopic spine surgery can now be performed with high magnification, thus allowing its application not only to lumbar spinal stenosis but also to spinal fusion surgeries and cervical and thoracic pathology as well. There has been increasing evidence in support of these newer techniques of spine surgery. Conclusions: For this report, we studied the currently available literature and outlined the historical evolution of endoscopic spine surgery, the various endoscopic systems and techniques available, and the current applications of endoscopic techniques as an alternative to traditional spinal surgery.

Comparative Analysis of Transforaminal Endoscopic Thoracic Discectomy and Microscopic Discectomy for Symptomatic Thoracic Disc Herniation

OBJECTIVE

To evaluate the clinical outcomes of transforaminal endoscopic thoracic discectomy (TETD) and microscopic discectomy (MD) for the treatment of symptomatic thoracic disc herniation (TDH).

METHODS

Seventy-seven patients (mean, 55.9 years; follow-up, 11.2 months) with symptomatic TDH were retrospectively reviewed (39 TETD and 38 MD). Radiological factors and perioperative outcomes were reviewed. Visual analogue scale (VAS), Oswestry Disability Index (ODI), and American Spinal Injury Association impairment scale were used to evaluate clinical and functional outcomes. Patient satisfaction was evaluated using modified MacNab criteria.

RESULTS

The levels of surgery and the location of hernia were evenly distributed in the both groups. The operative time (70.6 minutes vs. 175.7 minutes), estimated blood loss (3.8 mL vs. 357.4 mL), and length of hospital stay (7.0 days vs. 13.0 days) were significantly different between the TETD and MD groups (p < 0.05). VAS scores for dorsal back pain and ODI scores were significantly improved in both groups (p < 0.05). Patients who underwent TETD tended to be more satisfied with the outcome in terms of the modified MacNab criteria (89.7% vs. 73.0%, p = 0.059). Two patients in the MD group underwent revision surgery, whereas one patient in the TETD group underwent MD because of incomplete decompression.

CONCLUSION

TETD for the symptomatic TDH is a feasible and safe procedure that could be used for a wider range of surgical levels with a shorter operative time and hospital stay and less blood loss. While achieving similar outcomes, TETD achieved better patient satisfaction because of the use of local anesthesia and its minimal invasiveness.

Full Endoscopic Surgery for Thoracic Pathology: Next Step after Mastering Lumbar and Cervical Endoscopic Spine Surgery?

Thoracic disc herniation and stenosis are relatively rare, and various symptoms make them difficult to diagnose. Due to the complexity of neural and vascular structure, surgical treatment of thoracic pathology is challenging. Endoscopic spine surgery is an emerging minimally invasive surgical option. Based on wide experience on the cervical and lumbar spine, an endoscopic approach for the thoracic pathology can be performed beyond the learning curve. Transforaminal approach for thoracic disc herniation, endoscopic unilateral approach, and bilateral decompression for thoracic stenosis have been reported as favorable and safe surgical options. In the present study, the authors described the detailed surgical procedure as well as tips and tricks.

Full Endoscopic Thoracic Discectomy: Is the Interlaminar Approach an Alternative to the Transforaminal Approach? A Technical Note

BACKGROUND

Various approaches are used for decompressive surgeries in the thoracic spine depending on the location and consistency of the pathology, always avoiding manipulation of the thoracic spinal cord. Recently, there has been an effort to achieve adequate results and reduce morbidity with minimally invasive surgeries. Good outcomes and the advantages of full endoscopic spine surgery (FESS) have been proven for surgerical correction of herniated discs and stenoses in the lumbar and cervical spine. Similar evidence has recently been described for the thoracic spine, but it has not previously been reported in Brazil. Although the transforaminal approach is already established for the thoracic spine, the newly described interlaminar approach is equally efficient, and both techniques must be considered when treating thoracic spine diseases. The objective of the present article was to present the full endoscopic interlaminar and transforaminal techniques in patients with symptomatic disc herniation of the thoracic spine, discuss the rationality for implementing FESS in thoracic spine, and discuss the rationality in choosing between both approaches.

METHODS

Two patients were submitted to thoracic FESS. A transforaminal approach was chosen for a T10-T11 foraminal disc herniation; an interlaminar approach was selected for a paramedian T7-T8 disc extrusion. Data regarding operating time, intraoperative images, hospital stay, visual analog scales before and after FESS, course of recovery, and surgery satisfaction were evaluated.

RESULTS

The patients had eventless surgeries, improved from preoperative pain without morbidity. Both were satisfied and recovered well. Hospital stay was less than 6 hours after surgery.

CONCLUSIONS

Transforaminal and interlaminar FESS for thoracic disc herniation are safe, efficient, and minimally invasive alternatives.

CLINICAL RELEVANCE

Despite being an innovative technique with evident advantages, it should be carefully considered along with conventional technique for the treatment of thoracic spine diseases, since its clinical relevance is yet to be determined.

LEVEL OF EVIDENCE: 4

Spinal endoscopy: evidence, techniques, global trends, and future projections

The utilization of indirect visualization during procedures has been increasingly replacing traditional forms of direct visualization across many different surgical specialties. The adoption of arthroscopy, using small cameras placed inside joints, has transformed musculoskeletal care over the last several decades, allowing surgeons to provide the same anatomic solutions with less tissue dissection, resulting in lower requirements for inpatient care, reduced costs, and expedited recovery.  For a variety of reasons, spine surgery has lagged behind other specialties in the adoption of indirect visualization.  Nonetheless, patient demand for less invasive spine procedures and surgeon drive to provide these solutions and improve care quality has driven global adoption of spinal endoscopy.  There are numerous endoscopic platforms and techniques currently utilized, and these systems are rapidly evolving.  Additionally, the variance in technology and health system incentives across the globe has generated tremendous regional heterogeneity in the utilization of spinal endoscopic procedures.  We present a consolidated review, including the background, evidence, techniques, and trends in spinal endoscopy, so that clinicians can gain a deeper understanding of this rapidly evolving domain of spinal healthcare.

Posterior Minimally Invasive Transpedicular Approach for Giant Calcified Thoracic Disc Herniation

STUDY DESIGN

Retrospective case series.

OBJECTIVE

Posterior surgery for thoracic disc herniation was associated with increased morbidity and mortality and new minimally invasive approaches have been recommended for soft disc herniation but not for calcified central disc. The objective of this study is to describe a posterolateral microscopic transpedicular approach for central thoracic disc herniation.

METHODS

This is a single center retrospective review of all the cases of giant thoracic calcified disc herniation as defined by Hott et al. Presence of myelopathy, percentage of canal compromise, T2 hypersignal, ASIA score, and ambulatory status were recorded. This posterolateral technique using a tubular retractor was thoroughly described.

RESULTS

Eight patients were operated upon with a mean follow-up of 16 months. Mean canal compromise was 61%. Mean operative time was 228 minutes and mean operative bleeding was 250 mL. There were no cases of dural tear or neurologic degradation.

CONCLUSION

This is the first report of posterior minimally invasive transpedicular approach for giant calcified disc herniation. There were neither cases of neurological deterioration nor increased rate of dural tears. This technique is thus safe and could be recommended for treatment of this rare disease.

Thoracic Disc Herniation Manifesting as Abdominal Pain Alone Associated with Thoracic Radiculopathy

Symptomatic thoracic disc herniation (TDH) with thoracic radiculopathy alone is an extremely rare condition. Here, we report a rare case of TDH in a 52-year-old man who presented with medically refractory severe right flank pain. Based on pain distribution, pain intensity changes according to truncal position, ineffectiveness of intercostal nerve block, and radiological findings, his pain was determined to be caused by TDH at T9-10 level. Symptomatic TDH often requires invasive surgery. However, TDH with radiculopathy alone can be treated via a posterior approach without spinal cord manipulation or spinal fusion. We could eliminate the pain by removing TDH with hemilaminectomy and microdiscectomy using an O-arm-based navigation system.

Transforaminal Thoracic Interbody Fusion for Thoracic Disc Prolapse: Surgicoradiological Analysis of 18 Cases

STUDY DESIGN

Retrospective observational study.

OBJECTIVES

Thoracic disc prolapse (TDP) surgeries have reported complications ranging from paraplegia to approach related complications. This study is to present a series of TDP patients surgically treated with transforaminal thoracic interbody fusion (TTIF). Emphasis on surgical technique and strategies to avoid complications are analyzed.

METHODS

Eighteen patients with TDP were included. Imagings were analyzed for end-plate changes and calcification. Type of disc prolapse (central/para-central) and percentage of canal occupancy were noted. Objective outcome was quantified with Visual Analogue Scale (VAS), modified Nurick's grade, and ASIA (American Spinal Injury Association) score. All complications were noted.

RESULTS

Eighteen patients (average age 43.65 years) having total 22 levels operated, that included double level (n = 2) and missed level (n = 2) are reported. All patients had myelopathy. Calcification of disc (n = 13), central disc prolapses (n = 9), para-central (n = 11) and more than 50% canal occupancy (n = 8) were noted. VAS back pain, modified Nurick's grade and ASIA grade improved significantly in all patients. One patient had postoperative transient deficit. The functional score achieved its maximum at 1 year follow-up and remained static at final follow-up of 65.05 months. Union was achieved in all patients.

CONCLUSIONS

The most important factor for outcome in TDP is the technical aspect of avoiding cord manhandling and avoiding wrong level surgeries. TTIF is not devoid of complications but can give good results to posterior approach trained surgeons.

Overview of Minimally Invasive Spine Surgery

Minimally invasive spine surgery (MISS) has continued to evolve over the past few decades, with significant advancements in technology and technical skills. From endonasal cervical approaches to extreme lateral lumbar interbody fusions, MISS has showcased its usefulness across all practice areas of the spine, with unique points of access to avoid pertinent neurovascular structures. Adult spine deformity has also recognized the importance of minimally invasive techniques in its ability to limit complications and to provide adequate sagittal alignment correction and improvements in patients' functional status. Although MISS has continued to make significant progress clinically, consideration must also be given to its economic impact and the learning curve surgeons experience in adding these procedures to their armamentarium. This review examines current innovations in MISS, as well as the economic impact and future directions of the field.

Transforaminal endoscopic thoracic discectomy with foraminoplasty for the treatment of thoracic disc herniation

Background

Symptomatic thoracic disc herniation (TDH) is a rare clinical entity and surgical intervention for it is even more uncommon. Despite several surgical techniques being described for thoracic discectomy, considering the unique surgical challenges, none of them have been accepted universally. Minimally invasive techniques have brought in a paradigm shift in the management of cervical/lumbar spinal disorders and similar techniques have been extrapolated to the thoracic region too. The purpose of this paper is to describe our technique, surgical experience, and the clinical results of transforaminal endoscopic thoracic discectomy (TETD).

Methods

Consecutive patients who underwent TETD (2001-2018) were reviewed. Patients who had a minimum of 6 months of follow-up, and without cervical and lumbar spine surgery or trauma during the follow-up period were included in the study. TETD was performed in patients who presented with symptomatic disc herniation of the thoracic spine and did not respond to conservative treatments. Patients with calcified disc herniation or concomitant ossification of the posterior longitudinal ligament (OPLL) were excluded. Under local anesthesia and intravenous sedation, a 4.7-mm endoscope (TESSYS, Joimax GmbH, Germany) was introduced via transforaminal approach with foraminoplasty using reamer. Patient outcome was evaluated using visual analogue scale (VAS) and Oswestry disability index (ODI) scores. Patient satisfaction was measured using Macnab's criteria.

Results

Ninety-two consecutive patients (mean age was 48.9 years, 57 males) who underwent TETD from 2001 to 2018 met the inclusion criteria. Patients underwent surgery at different levels: 16 patients for T2-3 to T5-6 level, 41 cases for T6-7 to T8-9, and 35 patients for T9-10 to T12-L1. During follow-up for an average of 38.4 months, all patients showed a significant improvement of pain (7.6 to 1.6 in VAS and 68.2 vs. 13.2 for ODI, P<0.05 for both). There was one patient who had transient motor weakness.

Conclusions

TETD for soft, paramedian or lateral symptomatic TDH is a feasible and effective minimally invasive treatment option with favorable clinical results.

A Novel, Minimally Invasive Hybrid Technique to Approach Intracanal Herniated Thoracic Discs

BACKGROUND

Multiple options exist for thoracic disc herniation (TDH). However, when a specific technique is chosen, the goal is to avoid the manipulation of the spinal cord, which is already compressed.

OBJECTIVE

To describe a hybrid endoscopic technique for intracanal TDH by combining an oblique paraspinal approach (OPA) and transforaminal full-endoscopic discectomy.

METHODS

We describe the step-by-step operative technique and present the clinical and radiological outcomes of a case series of hybrid endoscopic thoracic discectomy.

RESULTS

A total of 3 patients were treated. We observed the usefulness of an OPA to enlarge the intervertebral foramen through the rigid tubular retractor and the feasibility of a full-endoscopic transforaminal approach to reach intracanal TDHs.

CONCLUSION

Early experience with the hybrid endoscopic technique for TDHs demonstrated acceptable clinical and radiological outcomes in the 3 patients treated; however, a larger sample size and a methodologically advantageous study to compare this procedure with conventional options are necessary to probe the full benefits of the hybrid technique.

Percutaneous endoscopic thoracic discectomy via posterolateral approach: A case report of migrated thoracic disc herniation

RATIONALE

Minimally invasive surgeries for thoracic disc herniation (TDH) evolved rapidly in recent years, and multiple approaches have been put forward. Thoracic discectomy via percutaneous spine endoscopy (PSE) is inadequately documented because of the low prevalence of TDH and the high difficulty of thoracic spine endoscopy techniques. Herein, we present a TDH case who underwent percutaneous endoscopic thoracic discectomy.

PATIENT CONCERNS

A 28-year-old male suffered backpain and partial paralysis in lower extremities.

DIAGNOSES

Magnet resonance imaging demonstrated T11-12 TDH, with cranially migrated disc fragment.

INTERVENTIONS

The patient underwent percutaneous endoscopic thoracic discectomy via posterolateral approach with the assistance of endoscopic reamer in the procedure of foramino-laminaplasty.

OUTCOMES

The patient's muscle force improved immediately, and the backpain relieved after 5 days post-surgery. In the 6-month follow-up, he had normal muscle force without paresthesia in lower limbs.

LESSONS

The innovative design of endoscopic reamer provides effective plasty and access establishment with lower risk and difficulty, which ensures the vision and the operating space of the procedure of decompression. With this technique, the indications of thoracic PSE were broadened to both ventral and dorsal thoracic stenosis.

Percutaneous Endoscopic Thoracic Discectomy in the Upper and Midthoracic Spine: A Technical Note

Despite the successful application of percutaneous endoscopic thoracic discectomy (PETD), its technical feasibility and outcomes for symptomatic upper and midthoracic disc herniation have not been reported yet. The purpose of this article was to evaluate the feasibility of the percutaneous transforaminal endoscopic approach to remove disc herniations in the upper and midthoracic spine. Fourteen consecutive patients (mean age, 42.4 years; 12 males, 2 females) who underwent PETD were included in the analysis. The procedure was performed under local anesthesia and intravenous sedation using the standard endoscopy instrument set. The transforaminal approach combined with foraminoplasty was used to access the herniated areas. Treatment outcomes were evaluated using visual analogue scale (VAS) scores, Oswestry Disability Index (ODI) scores, and the modified MacNab criteria. Four discectomies were performed at T2–3, 5 at T3–4, and 5 at T5–6. The mean follow-up period was 43.4 months, and all patients showed statistically significant postoperative improvement (VAS: 7.3 to 2.3, ODI: 53.5 to 16.9, p<0.05 for all). No serious complications were reported during follow-up. PETD for upper and midthoracic disc herniation is a feasible and effective minimally invasive treatment option with favorable clinical results.

A Review of Minimally Invasive Surgical Techniques for the Management of Thoracic Disc Herniations

Thoracic disc herniation (TDH) is a rare, but technically challenging, disorder. Apart from their unfamiliarity with this condition, surgeons are often posed with challenges regarding the diverse methods available to address TDH, the neurological disturbances accompanying the disorder, the prospect of iatrogenic cord damage during surgical procedures, and the complications associated with various surgical approaches. In today's era, when minimally invasive surgery has been incorporated into almost every aspect of managing spine disorders, it is necessary for surgeons to be aware of the various minimally invasive techniques available for the management of these rare and difficult conditions. In this review article, we provide a synopsis of the epidemiology, clinical features, and technical aspects of TDH, starting from level identification to intraoperative neuromonitoring and including important steps and guidance for all the minimally invasive approaches to TDH. We conclude the review by providing insights into the clinical decision-making process and outline the specific aspects of "giant" thoracic discs and indications for fusion in certain conditions. Outcomes of minimally invasive surgery for these conditions are generally favorable. The location of herniation is an important factor for surgical planning.

Analysis of the learning curve of the surgical procedure for the treatment of thoracic disc herniation using anterolateral transthoracic approach with the aid of image-guided system

BACKGROUND

In surgery, the learning process represents one of the critical topics in the development of a young surgeon where there is often no standardized learning program. The learning curve is defined by plotting proficiency as a function of time, or the number of repetitions. In this study, we analyzed the learning process for a rare and surgically demanding pathology such as thoracic disc herniations (TDHs) treated with an antero-lateral trans-thoracic approach.

METHODS

We analyzed a consecutive series of patients admitted with a diagnosis of TDHs. All patients underwent surgery using a standard antero-lateral trans-thoracic approach, assisted by navigation system based on intraoperative 3D imaging performed with O-Arm^™ (Medtronic; Dublin, Ireland) system.

RESULTS

Twenty-one patients underwent surgery from January 2012 to June 2017. The time analysis shows a progressive reduction in time from the first to the last case with continued improvement in operating time but progressively less dramatic, this is explicable considering the classic learning curve model. Predictably, a slow learning curve was charted - typical for a technically demanding procedure associated with a rare incidence of pathology.

CONCLUSIONS

A learning curve is an easy and efficient way to gauge the growth of a surgeon. After 21 cases we obtained an intermediate profile of learning curve between steep and shallow. Despite different alternatives for speeding up the learning process it is not always possible to standardize and reflect them in a learning process. Today, the use of technology is often considered in this but does not always affect the process itself.

Multi-level spine endoscopy: A review of available evidence and case report

In the last ten years, there has been an exponential increase in endoscopic spinal surgery practice.

With improvements in equipment quality and the availability of high definition camera systems, cervical endoscopic disc resection is now a viable alternative to anterior cervical decompression and fusion (ACDF) or disc arthroplasty for the treatment of disc prolapse and low grade stenosis.

Based on the current literature, there is now strong evidence to support the use of transforaminal endoscopic approaches for the treatment of thoracic disc prolapse.

There is now level I evidence to show that outcomes following transforaminal endoscopic discectomy (TED) are at least equivalent to those after open microdiscectomy, with an expected shorter operating time, lesser requirement for analgesia, reduced duration of post-operative disability, more rapid rehabilitation and lower costs of care. However, it should be recognised that there is a significant learning curve for TED.

New endoscopic techniques with interlaminar approaches allow the decompression of central and lateral recess stenosis. Future developments will facilitate vision and access to the spine with 3D imaging and robotics at the forefront.

We present a case report of whole spine endoscopic decompression to illustrate the potential of endoscopic surgery at all spinal levels.

Cite this article: EFORT Open Rev 2017;2:317-323. DOI: 10.1302/2058-5241.2.160087

Circumferential Decompression via a ModifiedCostotransversectomy Approach for the Treatment of Single Level Hard Herniated Disc between T10 -L1

OBJECTIVE

To describe a novel surgical strategy for circumferentially decompressing the T10 -L1 spinal canal when impinged upon by single level hard thoracic herniated disc (HTHD) via a modified costotransversectomy approach.

METHODS

This is a retrospective review of 26 patients (17 men, 9 women; mean age at surgery 48.5 years, range 20-77 years) who had undergone single level HTHD between T10 -L1 by circumferential decompression via a modified costotransversectomy approach. The characteristics of the approach are using a posterior midline covered incision, which keeps the paraspinal muscle intact and ensures direct visualization of circumferential spinal cord decompression of single level HTHD between T10 -L1 .

RESULTS

The average operative time was 208 ± 36 min (range, 154-300 min), mean blood loss 789 ± 361 mL (range, 300-2000 mL), mean preoperative and postoperative mJOA scores 5.2 ± 1.5 and 9.0 ± 1.3, respectively (t = 19.7, P < 0.05). The rate of recovery of neurological function ranged from 33.3% to 100%. The ASIA grade improved in 24 patients (92.3%) and stabilized (no grade change) in two (7.7%). MRI indicated that the cross-sectional area of the dural sac at the level of maximum compression increased from 45.0 ± 5.8 mm(2) preoperatively to 113.5 ± 6.1 mm(2) postoperatively (t = 68.2, P < 0.05). Anterior tibialis muscle strength of the 15 patients with foot drop had a mean recovery rate of 95% at final follow-up. One patient who resumed work early after the surgery showed a significantly augmented Cobb angle. One patient had transient postoperative cerebrospinal fluid leakage. No patients showed neurological deterioration.

CONCLUSIONS

This procedure achieves sufficient direct visualization for circumferential decompression of the spinal cord via a posterior midline covered costotransversectomy approach with friendly bleeding control and without muscle sacrifice. It is a reasonable alternative treatment option for thoracic myelopathy caused by single level HTHD between T10 -L1 .

Robotics and the spine: a review of current and ongoing applications

OBJECT

Robotics in the operating room has shown great use and versatility in multiple surgical fields. Robot-assisted spine surgery has gained significant favor over its relatively short existence, due to its intuitive promise of higher surgical accuracy and better outcomes with fewer complications. Here, the authors analyze the existing literature on this growing technology in the era of minimally invasive spine surgery.

METHODS

In an attempt to provide the most recent, up-to-date review of the current literature on robotic spine surgery, a search of the existing literature was conducted to obtain all relevant studies on robotics as it relates to its application in spine surgery and other interventions.

RESULTS

In all, 45 articles were included in the analysis. The authors discuss the current status of this technology and its potential in multiple arenas of spinal interventions, mainly spine surgery and spine biomechanics testing.

CONCLUSIONS

There are numerous potential advantages and limitations to robotic spine surgery, as suggested in published case reports and in retrospective and prospective studies. Randomized controlled trials are few in number and show conflicting results regarding accuracy. The present limitations may be surmountable with future technological improvements, greater surgeon experience, reduced cost, improved operating room dynamics, and more training of surgical team members. Given the promise of robotics for improvements in spine surgery and spine biomechanics testing, more studies are needed to further explore the applicability of this technology in the spinal operating room. Due to the significant cost of the robotic equipment, studies are needed to substantiate that the increased equipment costs will result in significant benefits that will justify the expense.

Calcified giant thoracic disc herniations: considerations and treatment strategies

INTRODUCTION

Giant herniated thoracic discs (GHTD) remain a surgical challenge. When combined with calcification, these discs require altered surgical strategies and have only been infrequently described. Our objective was to describe our surgical approaches in the management of calcified GHTD.

METHODS

This was a retrospective cohort study of all patients with calcified GHTD operated between 2004 and 2012. Data were collected from review of patients' notes and radiographs and included basic demographic and radiological data, clinical presentation and outcome, operative procedure and complications.

RESULTS

During the study period, there were 13 patients with calcified GHTD, including 6 males and 7 females (mean age 55 years, range 31-83 years). The average canal encroachment was 62% (range 40-90%); mean follow-up 37 months (12-98). All patients were treated with anterior thoracotomy, varying degrees of vertebral resection, removal of calcified disc and with or without reconstruction. The average time for surgery was 344 min (range 212-601 min) and estimated blood loss 1,230 ml (range 350-3,000 ml). Post-operatively, 8 patients improved by 1 Frankel grade (62%), 2 improved by 2 grades (15%) and 3 did not change their grade (23%). The complication rate was 4/13 (31%; 3 patients with durotomies (2 incidental, 1 intentional) and 1 with recurrence).

DISCUSSION

Calcified GHTD remain a surgical challenge. Anterior decompression through a thoracotomy approach, and varying degrees of vertebral resection with or without reconstruction allowed us to safely remove the calcified fragment. All patients remained the same (23%) or improved by at least 1 grade (77%) neurologically, without radiographic failure at final follow-up.

Transthoracic approach for the treatment of calcified giant herniated thoracic discs

OBJECTIVE

This study aimed at reporting the results of a transthoracic approach in the treatment of patients with calcified giant herniated thoracic discs (HTDs).

METHODS

Fifteen consecutive patients, 11 males and 4 females with a mean age of 46 years (range 33-61), with calcified giant HTDs underwent transthoracic decompression and segmental instrumentation with interbody fusion from November 2004 to September 2010. Clinical data retrospectively examined and compared were levels and types of disc herniation, operative time, blood loss, pre- and postoperative Frankel grades and Japanese Orthopedic Association (JOA) score, and complications.

RESULTS

Of the 15 patients, 2 had HTDs at two levels and affected discs were primarily at the T11/12 level (60%). Presenting symptoms included myelopathy, axial back pain, urinary symptoms, and radiculopathy. Disc herniations were classified as central (40%) or paracentral (60%). All discs were successfully removed without dural tears or cerebral spinal fluid leakage. The mean operation time was 179 ± 27 min (range 140-210 min), and the mean estimated blood loss was 840 ± 470 ml (range 300-2,000 ml). Frankel grades improved in 9 patients postoperatively and 12 patients at the last follow-up. The mean JOA score improved from 4.9 to 7.7. All patients reported improvement in symptoms. The average duration of follow-up was 45 ± 24 months (range 7-77 months).

CONCLUSIONS

Transthoracic decompression combined with reconstruction, fusion, and fixation is an effective method for the treatment of these lesions and is associated with a low rate of complications, morbidity, and neurological impairment.

Intracranial hypotension with a sixth cranial nerve palsy subsequent to massive thoracic CSF hygroma: a rare complication of thoracic disc excision

BACKGROUND

Thoracic cerebrospinal fluid (CSF) hygroma is a rare and potentially devastating complication of the anterior thoracic approach to the spine. We present two cases in which this complication resulted in acute cranial nerve palsy and discuss the pathoanatomy and management options in this scenario.

CASE REPORTS

Two male patients presented to our department with neurological deterioration due to a giant herniated thoracic disc. The extruded disc fragment was noted pre-operatively to be calcified in both patients. A durotomy was performed at primary disc prolapse resection in the first patient, whereas an incidental durotomy during the procedure caused complication in the second patient. These were repaired primarily or sealed with Tachosil(®). Both patients re-presented with acute diplopia. Imaging of both patients confirmed a massive thoracic cerebrospinal fluid hygroma and evidence of intracranial changes in keeping with intracranial hypotension, but no obvious brain stem shift. The hemithorax was re-explored and the dural repair was revised. The first patient made a full recovery within 3 months. The second patient was managed conservatively and took 5 months for improvement in his ophthalmic symptoms.

CONCLUSIONS

The risk of CSF leakage post-dural repair into the thoracic cavity is raised due to local factors related to the chest cavity. Dural repairs can fail in the presence of an acute increase in CSF pressure, for example whilst sneezing. Intracranial hypotension can result in subsequent hygroma and possibly haematoma formation. The resultant cranial nerve palsy may be managed expectantly except in the setting of symptomatic subdural haematoma or compressive pneumocephaly.

Posterior internal fixation plus vertebral bone implantation under navigational aid for thoracolumbar fracture treatment

The aim of this study was to investigate the method of posterior thoracolumbar vertebral pedicle screw reduction and fixation combined with vertebral bone implantation via the affected vertebral body under navigational aid for the treatment of thoracolumbar fractures. The efficacy of the procedure was also measured. Between June 2005 and March 2011, posterior thoracolumbar vertebral pedicle screw reduction and fixation plus artificial bone implantation via the affected vertebral pedicle under navigational aid was used to treat 30 patients with thoracolumbar fractures, including 18 males and 12 females, ranging in age from 21 to 57 years. Compared with the values prior to surgery, intraspinal occupation, vertebral height ratio and Cobb angle at the follow-up were significantly improved. At the long-term follow-up, the postoperative Cobb angle loss was <1° and the anterior vertebral body height loss was <2 mm. Posterior thoracolumbar vertebral pedicle screw reduction and fixation combined with vertebral bone implantation via the affected vertebral body under navigational aid may increase the accuracy and safety of surgery, and it is an ideal method of internal implantation. Bone implantation via the affected vertebral body may increase vertebral stability.