Towards a More Realistic Appraisal of Complications Following Staged Lateral Lumbar Interbody Fusion: A Single Institution Series

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

With steadily increasing implementation of far lateral approaches in spine surgery, surgeons can utilize the advantages of different approaches synergistically to ensure an optimal patient outcome. Our single institution study aimed to assess the complication rates of patients who underwent a lateral interbody fusion as the index procedure and additional anterior or posterior instrumentation as part of a planned staged surgical reconstruction effort.

METHODS

This study was approved by our institutional review board (STUDY2021000113). We included 576 patients who received a lateral lumbar interbody fusion (LLIF) as the index procedure followed by transforaminal lumbar interbody fusion (TLIF), posterior lumbar interbody fusion (PLIF) or anterior lumbar interbody fusion (ALIF) between 2016 and 2020. Primary outcomes were complications identified during the initial inpatient stay, which were categorized into approach-related and secondary complications. Secondary outcomes tracked up to 6 years post-surgery.

RESULTS

The overall complication rate was 19.2% (10.5% approach related, 8.7% secondary complications). Significant intraoperative hemorrhage (mean 659.3 mL vs 131.4 mL, P < .01) was the most common approach related complication with an incidence of 4%, followed by temporary hip flexor weakness in 2.6%. A permanent (femoral) nerve damage was verified in 1 patient. The most common secondary complication was impaired wound healing in 12 patients (2.1%). We identified a 7.1% (41 of 576 patients) rate of revision surgery, on average after 372 days (±34 days).

CONCLUSIONS

We recorded an overall complication rate of 19.2% for staged adult deformity corrective surgeries utilizing far lateral interbody fusions at several lumbar levels followed by a more comprehensive posterior surgical reconstruction.

Full-Endoscopic Technique for Posterior Fossa Decompression in Chiari Malformation

BACKGROUND AND IMPORTANCE

Full-endoscopic techniques are well-described for spinal procedures. Although endoscopic-assisted techniques are reported for posterior fossa decompression (PFD) in Chiari malformation (CM), a full-endoscopic technique is yet to be reported in these patients. The aim of this study was to present and describe a full-endoscopic technique for PFD in patients with CM.

CLINICAL PRESENTATION

Two patients diagnosed with CM were operated on by the full-endoscopic PFD technique. The patients consented to the procedure and to the publication of their image. An endoscope with an oval shaft cross-section with a diameter of 9.3 mm, a working length of 177 mm, a viewing angle of 20°, and a working channel of 5.6 diameters were used. Operative videos were recorded. The surgical steps were easily applied after the clear anatomic landmarks, such as the C1 posterior tubercle and the rectus capitis posterior minor muscles. The patients were followed up for 6 months. Both patients were symptom-free with a significant decrease in Visual Analog Scale score and a good functional outcome assessed by Chicago Chiari Outcome Scale after surgery without any complications.

CONCLUSION

All the steps of the full-endoscopic technique for PFD described by the authors in their previous human cadaveric study were also feasible on patients with CM.

Percutaneous Radiofrequency Disc Decompression: A Study of 27 Patients

BACKGROUND

Percutaneous radiofrequency nucleoplasty is a true minimally invasive technique for treatment for radiculopathy caused by contained disc protrusions. This minimally invasive procedure uses controlled thermoablation for reducing the intervertebral disc and decompressing the lumbar nerve root. Material and Methods: Our study is a prospective analysis of 27 patients aged from 30 to 64 years with lumbar disc protrusion who were treated with percutaneous radiofrequency disc decompression (PRFD) between May 2018 and May 2019. Clinical follow-up was reported at 1 month, 3 months, and 6 months. The outcomes were assessed using a visual analog scale (VAS) and MacNab score.

RESULTS

Of the 27 patients, 14 were female and 13 were male. Their mean age was 53 ± 2 years. In all 27 patients, percutaneous radiofrequency nucleotomy was performed. An excellent outcome as reflected by MacNab score was observed in 17 patients (63%), a good outcome in 8 patients (29.7%), and a poor outcome in 2 patients (7.3%). Prior to treatment, the average back and leg VAS scores were 7.95 and 7.82, respectively. At sixth month follow-up, the back and leg VAS scores were reduced to 3.17 and 3.04, respectively. Patients with a poor outcome developed early recurrent disc prolapse and required endoscopic discectomy.

CONCLUSION

PRFD is a safe and effective treatment of contained disc protrusion. PRFD is a good alternative to surgery. These procedures significantly increase quality of life in patients with lumbar radiculopathy.

Full-endoscopic anterior excision of thoracic disc herniations, including giant and calcified discs with spinal cord compression: surgical technique and outcomes

PURPOSE

Operations on thoracic herniated discs are comparatively rare and often demanding. An individual approach and mastery of different surgical techniques and surgical approaches are necessary. The main factors for the chosen surgical technique and approach are the anatomical localization, consistency of the pathology, the general condition of the patient and the experience of the surgeon. The purpose of this study was to evaluate the technical possibilities and outcomes of the full-endoscopic technique with interlaminar, extraforaminal and transthoracic retropleural approaches in patients with symptomatic herniated discs with anterior neural compression.

METHODS

In 49 patients with thoracic disc herniations, decompression was performed between 2016 and 2020, using a full-endoscopic interlaminar, extraforaminal or transthoracic retropleural approach. Clinical data and imaging were collected during follow-up of 18 months.

RESULTS

Sufficient decompression was achieved in all cases with the full-endoscopic surgical technique. Two patients experienced worsening of myelopathy, one of which was of transient duration, and one patient required reoperation for an epidural hematoma. No other complications were recorded. All other patients experienced a regression or improvement of symptoms.

CONCLUSION

The full-endoscopic technique with interlaminar, extraforaminal or transthoracic retropleural approach is a sufficient and minimally invasive method. All three full-endoscopic approaches of the thoracic spine are required to enable sufficient decompression of the anterior pathologies examined here.

Full-endoscopic technique for posterior fossa decompression in Chiari malformation type I: An anatomical feasibility study in human cadavers

Although endoscope-assisted techniques have been described, a full-endoscopic approach is yet to be performed for posterior fossa decompression (PFD) in Chiari malformation type I (CM-I). This study aims to describe the full-endoscopic PFD technique and evaluate its feasibility. Five fresh-frozen anonymized adult human cadavers were operated on using an endoscope with an oval shaft cross-section with a diameter of 9.3 mm, a working length of 177 mm, and a viewing angle of 20°. It also had an eccentric working channel with a diameter of 5.6 mm, a light guide, a sheath for continuous irrigation, and a rod lens system. The instruments were introduced from the working channel. Posterior craniocervical structures were dissected, and PFD was achieved. The planned steps were performed in all five cadavers. The endoscope was introduced to the posterior craniocervical region, dissecting the structures to easily expose the suboccipital bone and C1 posterior arch. Important structures, such as the C1 posterior tubercle, rectus capitis posterior minor muscles, and posterior atlantooccipital membrane, were used as landmarks. PFD was feasible even with the dural opening. Using the full-endoscopic approach, posterior craniocervical structures can be reached, and PFD can be performed successfully. The instruments used are well-defined for spinal usage; thus, this full-endoscopic technique can be widely used in the surgical treatment of patients with CM-I.

EULAR points to consider for the use of imaging to guide interventional procedures in patients with rheumatic and musculoskeletal diseases (RMDs)

OBJECTIVES

To develop evidence-based Points to Consider (PtC) for the use of imaging modalities to guide interventional procedures in patients with rheumatic and musculoskeletal diseases (RMDs).

METHODS

European Alliance of Associations for Rheumatology (EULAR) standardised operating procedures were followed. A systematic literature review was conducted to retrieve data on the role of imaging modalities including ultrasound (US), fluoroscopy, MRI, CT and fusion imaging to guide interventional procedures. Based on evidence and expert opinion, the task force (25 participants consisting of physicians, healthcare professionals and patients from 11 countries) developed PtC, with consensus obtained through voting. The final level of agreement was provided anonymously.

RESULTS

A total of three overarching principles and six specific PtC were formulated. The task force recommends preference of imaging over palpation to guide targeted interventional procedures at peripheral joints, periarticular musculoskeletal structures, nerves and the spine. While US is the favoured imaging technique for peripheral joints and nerves, the choice of the imaging method for the spine and sacroiliac joints has to be individualised according to the target, procedure, expertise, availability and radiation exposure. All imaging guided interventions should be performed by a trained specialist using appropriate operational procedures, settings and assistance by technical personnel.

CONCLUSION

These are the first EULAR PtC to provide guidance on the role of imaging to guide interventional procedures in patients with RMDs.

Early recognition of patients with axial spondyloarthritis—evaluation of referral strategies in primary care

Objective

Chronic inflammatory back pain (IBP) is frequently reported in axial SpA (axSpA) but also in the general population. We evaluated a recently proposed two-step referral system for early recognition of axSpA in primary care and compare it with other combinations of symptoms and SpA-related items.

Methods

Consecutive chronic back pain patients ≤45 years of age answered a questionnaire and were seen by a primary care physician who decided whether HLA-B27 needed to be determined. They were then referred to a rheumatologist who made the diagnosis. Generally sticking to the two-step system with HLA-B27 as an additional option, combinations with a sensitivity ≥90% and a likelihood ratio &gt;4 were compared.

Results

A total of 326 patients were included, 46 of whom were diagnosed with axSpA (14.1%). The sensitivity of the strategy was 87%, the specificity was 56.8% and the positive and negative predictive values were 24.8% and 96.4%, respectively. A ‘good response to NSAIDs’, ‘morning stiffness &gt;30 min’ and ‘elevated C-reactive protein’ performed best, with a sensitivity of 91%, specificity of 67%, positive predictive value of 31% and negative predictive value of 98%. On that basis, only three patients had to be seen by a rheumatologist to diagnose one.

Conclusion

The earlier proposed referral system worked well but was outperformed by other combinations with high sensitivity and better specificity, which deserve to be prospectively studied.

Surgical treatment of anterior cervical osteophytes causing dysphagia

PURPOSE

Dysphagia due to anterior cervical osteophytes is a rare condition. However, it can become serious enough to permanently impair the quality of life up to making normal food intake impossible. If conservative treatment fails, there is the option of surgical resection of the osteophytes. The objective of this study was to assess the outcomes of resections of anterior cervical osteophytes causing spondylogenic dysphagia, taking literature into consideration.

METHOD

Resection of anterior cervical osteophytes using a standard anterior approach was performed in 14 consecutive patients with spondylogenic dysphagia between 2009 and 2015. Indomethacin or radiation was used to prevent recurrence. Imaging and clinical data were collected in follow-up examinations over an average of 50 months.

RESULTS

The osteophytes were sufficiently resected in all cases. Anterior plates were placed in three patients due to pronounced segmental mobility. Five patients were given recurrence prevention in the form of indomethacin, nine with radiation. One patient required revision surgery for a hematoma. No other serious complications were observed. All patients had significant improvement of their symptoms. No recurrences or signs of increasing instability were found during the follow-up period.

CONCLUSION

When conservative treatment fails, surgical resection of cervical osteophytes is a sufficient method for treating spondylogenic dysphagia. High patient satisfaction and improvement of the quality of life are achieved with a low complication rate. Routine additional stabilization has been discussed as recurrence prevention. Prophylaxis using indomethacin or radiation, known primarily from hip replacement, also appears to be an option.

AOSpine Consensus Paper on Nomenclature for Working-Channel Endoscopic Spinal Procedures

STUDY DESIGN

International consensus paper on a unified nomenclature for full-endoscopic spine surgery.

OBJECTIVES

Minimally invasive endoscopic spinal procedures have undergone rapid development during the past decade. Evolution of working-channel endoscopes and surgical instruments as well as innovation in surgical techniques have expanded the types of spinal pathology that can be addressed. However, there is in the literature a heterogeneous nomenclature defining approach corridors and procedures, and this lack of common language has hampered communication between endoscopic spine surgeons, patients, hospitals, and insurance providers.

METHODS

The current report summarizes the nomenclature reported for working-channel endoscopic procedures that address cervical, thoracic, and lumbar spinal pathology.

RESULTS

We propose a uniform system that defines the working-channel endoscope (full-endoscopic), approach corridor (anterior, posterior, interlaminar, transforaminal), spinal segment (cervical, thoracic, lumbar), and procedure performed (eg, discectomy, foraminotomy). We suggest the following nomenclature for the most common full-endoscopic procedures: posterior endoscopic cervical foraminotomy (PECF), transforaminal endoscopic thoracic discectomy (TETD), transforaminal endoscopic lumbar discectomy (TELD), transforaminal lumbar foraminotomy (TELF), interlaminar endoscopic lumbar discectomy (IELD), interlaminar endoscopic lateral recess decompression (IE-LRD), and lumbar endoscopic unilateral laminotomy for bilateral decompression (LE-ULBD).

CONCLUSIONS

We believe that it is critical to delineate a consensus nomenclature to facilitate uniformity of working-channel endoscopic procedures within academic scholarship. This will hopefully facilitate development, standardization of procedures, teaching, and widespread acceptance of full-endoscopic spinal procedures.

Worldwide research productivity in the field of full-endoscopic spine surgery: a bibliometric study

PURPOSE

To investigate the quantity and quality of articles in the field of full-endoscopic spine surgery (FESS) from different countries and assess characteristics of worldwide research productivity.

METHODS

Articles published from 1997 to July 23, 2018, were screened using the Web of Science database. All studies were assessed for the following parameters: the number of total publications, h-index, contribution of countries, authors, journals, and institutions.

RESULTS

A total of 408 articles were identified between 1997 and 2018. Between 1997 and 2017, the number of published articles tended to increase by 41 times. The largest number of articles was from China (30.15%), followed by South Korea (28.68%), the USA (13.97%), Germany (9.31%), and Japan (4.90%). The highest h-index was found for articles from South Korea (23), followed by the USA (18), Germany (16), China (11), and Japan (7). The highest number of articles was published in World Neurosurgery (12.50%), followed by Pain Physician (10.29%), Spine (6.62%), European Spine Journal (4.66%), and Journal of Neurosurgery: Spine (4.17%). Wooridul Spine Hospital published the largest number of articles (10.29%), followed by Tongji University (5.88%), University of Witten/Herdecke (5.39%), Brown University (5.15%), and Third Military Medical University (3.43%).

CONCLUSIONS

The number of articles published in the field of FESS has increased rapidly in the past 20 years. In terms of quantity, China is the most contributive country based on the number of publications. High-quality papers as measured by h-index and the large quantity is from South Korea (second only to China). These slides can be retrieved under Electronic Supplementary Material.

3309Complement activation leads to C3 and C5 dependent prothrombotic alterations of fibrin clots

Background and aims

Alterations of clot structure with thin fibres, small pores and prolonged fibrinolysis are associated with an increased cardiovascular risk. We previously demonstrated complement C3 to be incorporated into fibrin clots resulting in prolongation of fibrinolysis, an effect which was exaggerated in patients with diabetes. Patients with diabetes are known to display higher levels of complement activation. However, the role of complement activation in particular activation of C3 and C5 on clot lysis time remains unexplored. Thus, the present study seeks to determine whether activation of complement C3 and C5 by cobra venom factor (CVF) has an impact on fibrin clot structure and clot lysis.

Materials and methods

Fibrin clot structure and lysis were determined in a plasma pool of healthy controls in the presence and absence of the complement C3 and C5 activator CVF using a validated turbidimetric assay and scanning electron microscopy. C3 activation was inhibited by the addition of the small 14-AA-peptide Cp40, while C5 activation was blocked by the addition of the FDA approved monoclonal antibody eculizumab (Emab).

Results

Complement activation with CVF leads to a prothrombotic clot structure with thinner fibres (Co 0.20±0.001 au, CVF 0.13±0.001 au; p<0.0001) and prolongation of clot lysis time (Co 864±32 sec, CVF 1665±17 sec; p<0.0001), which was confirmed by electron microscopy (Co 94.7±1.44 nm, CVF 60.7±0.96 nm; p<0.0001). Inhibition of C3 activation by Cp40 improved clot structure resulting in thicker fibres (Co 0.20±0.001 au, CVF 0.13±0.001 au, CP40 0.20±0.002 au; p<0.0001) and shorter clot lysis time (Co 100%, CVF 181±8.9%, CP40 139±7.8%; p<0.0001), while scrambled protein had no effect on either clot structure or lysis time. As CVF can also activate C5 convertase we next investigated the inhibition of complement C5 activation with eculizumab. The latter improved both fibre thickness (Co 0.20±0.002 au, CVF 0.13±0.003 au, Emab 0.16±0.006 au; p<0.0001) and clot lysis time (Co 100%, CVF 192±12%, Emab 140±11%; p<0.001). The combined inhibition of C3 and C5 activation using both, Cp40 and eculizumab in combination optimized clot structure (Co 0.22±0.001 au, CVF 0.13±0.0006 au, Cp40/Emab 0.21±0.001 au; Co vs. Cp40/Emab p=0.003) and restored clot lysis time (Co 100%, CVF 226±6%, CP40/Emab 104±1%; Co vs. Cp40/Emap p=0.8). The results were confirmed by electron microscopy (fibre thickness: Co 93±1.4 nm, CVF 68±1.3 nm, Cp40 83±1.4 nm, Emab 78±1.7 nm, CP40/Emap 95±1.6 nm).

Conclusions

Complement activation at the level of complement C3 and C5 has a detrimental impact on clot properties. Blocking C3 and C5 activation can restore both clot density and prolongation of clot lysis time. Further studies are needed to determine the underlying binding sites on fibrin(ogen) to pave the way for molecules improving clot properties without affecting immune responses.

Acknowledgement/Funding

KS is supported by the German Research Foundation (DFG) (SFB/TRR219 C-07; HE 5666/1-2 to KS (née Hess)]

[Minimally invasive decompression techniques for spinal cord stenosis]

BACKGROUND

Lumbar spinal canal stenosis is frequently found among elderly patients and significantly limits their quality of life. Non-surgical therapy is an initial treatment option; however, it does not eliminate the underlying pathology. Surgical decompression of the spinal canal has now become the treatment of choice.

OBJECTIVE

Minimalization of surgical approach strategies with maintaining sufficient decompression of the spinal canal and avoiding disadvantages of macrosurgical techniques, monolateral paravertebral approach with bilateral intraspinal decompression, specific surgical techniques.

MATERIALS AND METHODS

Minimally invasive decompression techniques using a microscope or an endoscope are presented and different surgical strategies depending on both the extent (mono-, bi-, and multisegmental) and the location of the stenosis (intraspinal central, lateral recess, foraminal) are described.

RESULTS

Minimally invasive microscopic or endoscopic decompression procedures enable sufficient widening of the spinal canal. Disadvantages of macrosurgical procedures (e. g., postoperative instability) can be avoided. The complication spectrum overlaps partially with that of macrosurgical interventions, albeit with significantly less marked severity. Subjective patient outcome is clearly improved.

CONCLUSIONS

Referring to modern minimally invasive decompression procedures, surgery of lumbar spinal canal stenosis represents a rational and logical treatment alternative, since causal treatment of the pathology is only possible with surgery.

Surgical treatment of cervical subaxial intraspinal extradural cysts using a full-endoscopic uniportal posterior approach

PURPOSE

Symptomatic intraspinal extradural cysts of the cervical subaxial spine are rare, but usually require surgery. Conventional posterior decompression is the gold standard. However, there is increasing experience with endoscopic surgical techniques. The purpose of the study is to evaluate the technical implementation and outcomes of a full-endoscopic uniportal technique via the posterior approach in patients with symptomatic intraspinal extradural cysts of the cervical subaxial spine.

METHODS

Seven consecutive patients with a subaxial location of symptomatic intraspinal extradural cysts were decompressed in a full-endoscopic uniportal technique via the posterior approach between 2009 and 2015. Imaging and clinical data were collected in follow-up examinations for 18 months.

RESULTS

In all cases, the cyst was completely removed and adequate decompression was achieved using the full-endoscopic uniportal technique. One patient developed a dural leak that was sutured and covered intraoperatively. No other complications requiring treatment were observed. All patients had a good clinical outcome with stable regression of the radicular and central nerve pain or neurological deficits. The imaging follow-up showed sufficient decompression in all cases. No evidence was found of increasing instability during the follow-up period.

CONCLUSION

The full-endoscopic uniportal operation with a posterior approach allows the resection of the cyst and can minimize trauma and destabilization and has technical benefits and a low complication rate. It is an alternative surgical method that can offer advantages and is considered by the authors to be the surgical technique of choice for cervical subaxial intraspinal extradural cysts.

The full-endoscopic uniportal technique for decompression of the anterior craniocervical junction using the retropharyngeal approach: an anatomical feasibility study in human cadavers and review of the literature

Objective

Acute or progressive myelopathy may necessitate direct anterior decompression of the craniocervical junction and odontoidectomy. Different techniques with individual advantages and disadvantages can be used. In addition to the gold standard-the transoral approach-there is also increasing experience with the endoscopic transnasal technique. Other alternative methods are also being developed to reduce technical and perioperative problems. The aim of this anatomical study was to investigate the feasibility of the full-endoscopic uniportal technique with a retropharyngeal approach for decompression of the craniocervical junction, taking into consideration the specific advantages and disadvantages compared with conventional methods and the currently available data in the literature.

Methods

Five fresh adult cadavers were operated on. The endoscope used has a shaft cross-section of 6.9 × 5.9 mm and a 25° viewing angle. It contains an eccentric intraendoscopic working channel with a diameter of 4.1 mm. An anterior retropharyngeal approach was used. The anatomical structures of the anterior craniocervical junction were dissected and the bulbomedullary junction was decompressed.

Results

The planned steps of the operation were performed in all cadavers. The retropharyngeal approach allowed the target region to be accessed easily. The anatomical structures of the anterior craniocervical junction could be identified and dissected. The bulbomedullary junction could be adequately decompressed. No resections of the anterior arch of the atlas were necessary in the odontoidectomy.

Conclusions

Using the full-endoscopic uniportal technique with an anterior retropharyngeal approach, the craniocervical region can be adequately reached, dissected, and decompressed. This is a minimally invasive technique with the known advantages of an endoscopic procedure under continuous irrigation. The retropharyngeal approach allows direct, sterile access. The instruments are available for clinical use and have been established for years in other operations of the entire spine.

Full-endoscopic uniportal retropharyngeal odontoidectomy for anterior craniocervical infection

BACKGROUND

Infections of the anterior craniocervical junction may require surgery. There are various techniques with individual advantages and disadvantages. This study evaluates the full-endoscopic uniportal technique via the anterior retropharyngeal approach for odontoidectomy, decompression, and debridement.

MATERIAL AND METHODS

Three patients with an infection of the anterior craniocervical junction with retrodental involvement were operated on between 2014 and 2016 using the full-endoscopic uniportal technique. Posterior stabilization was also performed with the same procedure for all patients.

RESULTS

The operation was technically satisfactory in all cases. No problems due to swelling of the pharyngeal soft tissue occurred. No other complications were observed. All patients had a satisfactory outcome with stable regression of the myelopathy symptoms and/or complete healing of the infection. The follow-up images showed sufficient decompression of bone and soft tissues in all cases.

CONCLUSIONS

The full-endoscopic uniportal technique with an anterior retropharyngeal approach can be an adequate and minimally invasive surgical technique for odontoidectomy, decompression, and debridement in infections of the craniocervical junction and can reduce access-related problems. The transoral, transnasal, and retropharyngeal approaches have different surgical fields due to the access trajectories, which must be taken into consideration depending on the anatomy and pathology when selecting a suitable technique.

Operation of Soft or Calcified Thoracic Disc Herniations in the Full-Endoscopic Uniportal Extraforaminal Technique

Background: Surgery for thoracic disc herniation and stenosis is comparatively rare and often demanding. The goal is to achieve sufficient decompression without manipulating the spinal cord and to minimize surgical trauma and its consequences. Individual planning and various surgical techniques and approaches are required. The key factors for selecting the technique are anatomical location, consistency of the pathology, general condition of the patient, and the surgeon’s experience. Objectives: The objective of the study was the evaluation of the technical implementation and outcomes of a full-endoscopic uniportal technique via the extraforaminal approach in patients with symptomatic soft or calcified disc herniation of the thoracic spine, taking specific advantages and disadvantages and literature into consideration. Study Design: Retrospective study Setting: A center for spine surgery and pain medicine. Methods: Between 2009 and 2015, decompression was performed on 26 patients with thoracic disc herniation or stenosis with radicular or myelopathic symptoms in a full-endoscopic uniportal technique with an extraforaminal approach. No patients underwent additional posterior stabilization. Imaging and clinical data were collected in follow-up examinations for 18 months. Results: Sufficient decompression was achieved in the full-endoscopic uniportal technique in all cases. The individual selection of the respective approach made it possible to reach the target area without manipulating the spinal cord. One patient experienced deterioration of a myelopathy. No other serious complications were observed. All patients, except one, experienced regression or improvement of symptoms. No evidence of increasing instability was found in imaging. Limitations: This is a retrospective study. The limited number of cases must be considered. Conclusions: The full-endoscopic uniportal technique with an extraforaminal approach was found to be a sufficient and minimally invasive method with the known advantages of an endoscopic procedure under continuous irrigation for monosegmental disc herniations. The inclusion criteria must be taken into consideration. If they are not met, an alternative full-endoscopic approach (interlaminar, transthoracic retropleural) or decompression in a conventional method must be selected. Additional stabilization does not appear to be necessary due to the low level of trauma. Key Words: Extraforaminal approach, thoracic disc herniation, giant disc herniation, Fullendoscopic, minimally invasive, thoracic spine

Operation of Soft or Calcified Thoracic Disc Herniations in the Full-Endoscopic Uniportal Extraforaminal Technique

BACKGROUND

Surgery for thoracic disc herniation and stenosis is comparatively rare and often demanding. The goal is to achieve sufficient decompression without manipulating the spinal cord and to minimize surgical trauma and its consequences. Individual planning and various surgical techniques and approaches are required. The key factors for selecting the technique are anatomical location, consistency of the pathology, general condition of the patient, and the surgeon's experience.

OBJECTIVES

The objective of the study was the evaluation of the technical implementation and outcomes of a full-endoscopic uniportal technique via the extraforaminal approach in patients with symptomatic soft or calcified disc herniation of the thoracic spine, taking specific advantages and disadvantages and literature into consideration.

STUDY DESIGN

Retrospective study.

SETTING

A center for spine surgery and pain medicine.

METHODS

Between 2009 and 2015, decompression was performed on 26 patients with thoracic disc herniation or stenosis with radicular or myelopathic symptoms in a full-endoscopic uniportal technique with an extraforaminal approach. No patients underwent additional posterior stabilization. Imaging and clinical data were collected in follow-up examinations for 18 months.

RESULTS

Sufficient decompression was achieved in the full-endoscopic uniportal technique in all cases. The individual selection of the respective approach made it possible to reach the target area without manipulating the spinal cord. One patient experienced deterioration of a myelopathy. No other serious complications were observed. All patients, except one, experienced regression or improvement of symptoms. No evidence of increasing instability was found in imaging.

LIMITATIONS

This is a retrospective study. The limited number of cases must be considered.

CONCLUSIONS

The full-endoscopic uniportal technique with an extraforaminal approach was found to be a sufficient and minimally invasive method with the known advantages of an endoscopic procedure under continuous irrigation for monosegmental disc herniations. The inclusion criteria must be taken into consideration. If they are not met, an alternative full-endoscopic approach (interlaminar, transthoracic retropleural) or decompression in a conventional method must be selected. Additional stabilization does not appear to be necessary due to the low level of trauma.

KEY WORDS

Extraforaminal approach, thoracic disc herniation, giant disc herniation, Full-endoscopic, minimally invasive, thoracic spine.

Full-endoscopic uniportal decompression in disc herniations and stenosis of the thoracic spine using the interlaminar, extraforaminal, or transthoracic retropleural approach

OBJECTIVE Surgery for thoracic disc herniation and spinal canal stenosis is comparatively rare and often challenging. Individual planning and various surgical techniques and approaches are required. The key factors for selecting the technique and approach are anatomical location, consistency of the pathology, general condition of the patient, and the surgeon's experience. The objective of the study was to evaluate the technical implementation and outcomes of a full-endoscopic uniportal technique via the interlaminar, extraforaminal, or transthoracic retropleural approach in patients with symptomatic disc herniation and stenosis of the thoracic spine, taking specific advantages and disadvantages and literature into consideration. METHODS Between 2009 and 2015, decompression was performed in 55 patients with thoracic disc herniation or stenosis using a full-endoscopic uniportal technique via an interlaminar, extraforaminal, or transthoracic retropleural approach. Imaging and clinical data were collected during follow-up examinations for 18 months. RESULTS Sufficient decompression was achieved in the full-endoscopic uniportal technique. One patient required revision due to secondary bleeding, and another exhibited persistent deterioration on myelopathy. No other serious complications were observed. All but one patient experienced regression or improvement of their symptoms. CONCLUSIONS The full-endoscopic uniportal technique with an interlaminar, extraforaminal, or transthoracic retropleural approach was found to be a sufficient and minimally invasive method. To cover the entire range of thoracic disc herniations and stenosis within the criteria named, all full-endoscopic approaches are required.

Decompression for cervical disc herniation using the full-endoscopic anterior technique

OBJECTIVE

Resection of a cervical disc herniation using a full-endoscopic technique with an anterior approach.

INDICATION

Fresh disc herniation with monoradicular symptoms in the upper extremity.

CONTRAINDICATIONS

Pure neck pain, cervical myelopathy, older and calcified disc herniations, higher grade of instability and deformity.

SURGICAL TECHNIQUE

Introduction of a guidewire and dilatator to a cervical disc using an anterior approach. Under full-endoscopic view, preparation of the posterior parts of the annulus, opening of the annulus and posterior longitudinal ligament and resection of the herniated fragment from the epidural space.

POSTOPERATIVE MANAGEMENT

Immediate mobilisation, isometric/coordinative exercises, functional exercises from week 3, building up strength from week 6.

RESULTS

A total of 120 patients were operated using the full-endoscopic or microsurgically assisted technique and were followed up for 24 months. Significant improvement was achieved in both groups. The group of full-endoscopic operated patients returned to work significantly earlier and 89% of all patients would undergo the operation again.

Full-endoscopic interlaminar operations in lumbar compressive lesions surgery: prospective study of 350 patients - "ENDOS" Study

BACKGROUND

Full-endoscopic operations of lumbar spine are truly minimally invasive surgical procedures. Endoscopic techniques have become the standard in many areas because of the advantages they offer intraoperatively and after surgery. With the interlaminar and transforaminal approach, two full-endoscopic procedures are available for lumbar compressive lesion operations. Our aim was to present and explain all aspects of the full-endoscopic operative technique, and presentation of results of lumbar discectomies and monosegmental decompression in full-endoscopic interlaminar technique performed during 3-year period in comparison with conventional microsurgical operations reported in literature.

METHODS

A series of 350 patients underwent full-endoscopic interlaminar lumbar discectomy, and spinal canal decompression, during a 3-year period, is analyzed. In addition to general and specific parameters, VAS and ODI scale are used as measuring instruments.

RESULTS

In our clinical series of full-endoscopic operations 88% of the patients no longer had leg pain postoperatively, and 7% had only occasional pain. In 7 (2%) patients minor nerve damage resulted in transient paresthesias, and in 2 patients resulted in neurological deficit. Dural tear occurred in 8 (2.3%) patients, and only 1 had reoperation for direct dural repair. The recurrence rate was 5.7% (3.7% had reoperation). Resection of the herniated disc and sufficient decompression was technically possible in all cases.

CONCLUSIONS

The clinical results of the full-endoscopic technique are at least equal to those of the conventional microsurgical discectomy with advantages such as reduced tissue trauma, improved patient mobility, and lower overall complication rate. With the possibility of selecting the most adequate approach, lumbar disc herniations inside and outside the spinal canal, can be sufficiently removed using the full-endoscopic technique, when taking the appropriate indication criteria into account.

Bilateral spinal decompression of lumbar central stenosis with the full-endoscopic interlaminar versus microsurgical laminotomy technique: a prospective, randomized, controlled study

BACKGROUND

Extensive decompression with laminectomy, where appropriate, is often still described as the method of choice when operating on degenerative lumbar spinal stenosis. Nonetheless, tissue-sparing procedures are becoming more common. Endoscopic techniques have become the standard in many areas because of the surgical advantages they offer and the benefits for rehabilitation. One key issue when operating on the spine was the development of instruments to provide sufficient bone resection under continuous visual control. This was achieved by using endoscopes for operations carried out in cases of spinal canal stenosis.

OBJECTIVE

This study of patients with degenerative lumbar central spinal stenosis compares the results of spinal decompression using the full-endoscopic interlaminar technique (FI) with a conventional microsurgical laminotomy technique (MI).

STUDY DESIGN

Prospective, randomized, controlled study.

SETTINGS

135 patients with microsurgical or full-endoscopic decompression were followed up for 2 years. Alongside general and specific parameters, the following measuring instruments were also used for the investigation: Visual Analog Scale (VAS), German version of the North American Spine Society Instrument (NASS), Oswestry Low-Back-Pain-Disability Questionnaire (ODI).

RESULTS

Postoperatively 72 % of the patients no longer had leg pain or the pain was almost completely reduced and 21.2 % experienced occasional pain. The clinical results were the same in both groups. The rate of complications and revisions was significantly reduced in the FI Group. The full-endoscopic techniques brought advantages in the following areas: operation, complications, traumatization, rehabilitation.

LIMITATIONS

Lack of placebo control group.

CONCLUSIONS

The recorded results demonstrate that the full-endoscopic interlaminar bilateral decompression adopting a unilateral approach provides an adequate and safe supplement and alternative to the conventional microsurgical bilateral laminotomy technique when the indication criteria are fulfilled. At the same time, it offers the advantages of a minimally invasive intervention.

Operation of Lumbar Zygoapophyseal Joint Cysts Using a Full-Endoscopic Interlaminar and Transforaminal Approach

In appropriate situations, extensive decompression with laminectomy often continues to be described as the method of choice for operations involving lumbar zygoapophyseal joint (z-joint) cysts. Tissue-sparing procedures are nevertheless becoming more common. Endoscopic techniques have become the standard procedures in many areas because of the advantages they offer in terms of surgical technique and in rehabilitation. One key aspect in spinal surgery was the development of instruments for sufficient bone resection carried out under continuous visual control. This enabled endoscopes to be used when operating on z-joint cysts. The objective of this prospective study was to examine the technical possibilities for the full-endoscopic interlaminar and transforaminal technique in lumbar z-joint cysts. A total of 74 patients were followed up for 2 years. The results show that 85% of the patients no longer have any leg pain or that the pain had been almost completely eliminated, and 11 % experience occasional pain. The complication rate was low. The full-endoscopic techniques brought advantages in the following areas: operation, complications, traumatization, and rehabilitation. The recorded results show that full-endoscopic resection of a z-joint cyst using an interlaminar and transforaminal approach provides an adequate and safe supplement, and is an alternative to conventional procedures when the indication criteria are fulfilled. It also offers the advantages of a minimally invasive intervention.

The current state of endoscopic disc surgery: review of controlled studies comparing full-endoscopic procedures for disc herniations to standard procedures

BACKGROUND

Neuropathic pain originating from spinal disc herniations is a very common problem. The majority of disc surgeries are performed to alleviate this pain once conservative measures and targeted injections have failed. Endoscopic spinal surgery is increasingly popular because it minimizes access trauma and hastens recovery from the intervention. This clinically oriented review evaluates controlled studies that investigate the clinical results and the complications of full-endoscopic lumbar and cervical procedures for symptomatic disc herniations in comparison to a microsurgical standard procedure. This review focuses exclusively on modern, full-endoscopic disc surgery irrespective of the specific access technique (e.g., interlaminar vs. transforaminal) and irrespective of the spinal region.

STUDY DESIGN

Comprehensive review of the literature.

OBJECTIVE

To assess the clinical outcomes and complication rates of full-endoscopic disc surgery compared to the microsurgical standard procedures.

METHODS

A PubMed and Embase search was performed, considering entries up to January 2013. All 504 results were screened and categorized. Only 4 randomized controlled trials (RCTs) and one controlled studies (CS) could finally be considered for evaluation. All 5 manuscripts were meticulously analyzed with regards to randomization mode, inclusion/exclusion criteria, clinical results, and complication rates.

RESULTS

Overall, the endoscopic techniques had shorter operating times, less blood loss, less operative site pain, and faster postoperative rehabilitation/shorter hospital stay/faster return to work than the microsurgical techniques. There were no significant differences in the main clinical outcome criteria between the endoscopic and the microsurgical techniques in any of the trials. All 5 studies had fewer complications with the endoscopic technique and this was statistically significant in 2 of the studies. One study showed a lower rate of revision surgeries requiring arthrodesis with the endoscopic technique.

LIMITATIONS

All 5 studies that could be considered originate from experienced investigators and all 4 RCTs came from one group. This limits the transferability of their results to surgeons less experienced in endoscopic disc surgery.

CONCLUSIONS

The studies show that full-endoscopic disc surgery can achieve the same clinical results in symptomatic cervical and lumbar disc herniations as the microsurgical standard techniques. This does not appear to come at the price of higher complication rates.

Disc volume reduction with percutaneous nucleoplasty in an animal model

Study Design

We assessed volume following nucleoplasty disc decompression in lower lumbar spines from cadaveric pigs using 7.1Tesla magnetic resonance imaging (MRI).

Purpose

To investigate coblation-induced volume reductions as a possible mechanism underlying nucleoplasty.

Methods

We assessed volume following nucleoplastic disc decompression in pig spines using 7.1-Tesla MRI. Volumetry was performed in lumbar discs of 21 postmortem pigs. A preoperative image data set was obtained, volume was determined, and either disc decompression or placebo therapy was performed in a randomized manner. Group 1 (nucleoplasty group) was treated according to the usual nucleoplasty protocol with coblation current applied to 6 channels for 10 seconds each in an application field of 360°; in group 2 (placebo group) the same procedure was performed but without coblation current. After the procedure, a second data set was generated and volumes calculated and matched with the preoperative measurements in a blinded manner. To analyze the effectiveness of nucleoplasty, volumes between treatment and placebo groups were compared.

Results

The average preoperative nucleus volume was 0.994 ml (SD: 0.298 ml). In the nucleoplasty group (n = 21) volume was reduced by an average of 0.087 ml (SD: 0.110 ml) or 7.14%. In the placebo group (n = 21) volume was increased by an average of 0.075 ml (SD: 0.075 ml) or 8.94%. The average nucleoplasty-induced volume reduction was 0.162 ml (SD: 0.124 ml) or 16.08%. Volume reduction in lumbar discs was significant in favor of the nucleoplasty group (p<0.0001).

Conclusions

Our study demonstrates that nucleoplasty has a volume-reducing effect on the lumbar nucleus pulposus in an animal model. Furthermore, we show the volume reduction to be a coblation effect of nucleoplasty in porcine discs.

[Differential diagnosis of back pain in patients with ankylosing spondylitis: instable cervical spine fracture]

HISTORY AND ADMISSION FINDINGS

A 65-year-old patient with longstanding ankylosing spondylitis (AS) complained of persistent pain in the right shoulder and the neck; elevation of the shoulder was impaired. The symptoms had started a week before admission after a fall. Physical examination revealed generally decreased mobility of an already hyperkyphotic cervical spine (CS) and decreased thoracic excursion. The paravertebral muscles were stiff .

CLINICAL INVESTIGATIONS

Because of the trauma extensive imaging procedures with conventional radiographs, magnetic resonance imaging (MRI) and computed tomography (CT) of the CS were performed. These showed a compression fracture of C5, detachment of the dorsal and ventral ligaments and a ventral dislocation of C4 with dislocation (Type C fracture).

TREATMENT AND COURSE

After immediate consultation of the cooperating center for spinal surgery corpectomy of C5 and ventral fusion of C3-7 were performed on the same day, together with a dorsal transpedicular fusion. During the imaging procedures symptoms of a beginning paraplegia occurred. After successful surgery and early postoperative rehabilitation, the patient was discharged to an in-patient rehabiltation unit. At discharge, there was but a slight paresis of the right arm.

CONCLUSION

Patients with AS and advanced spinal ankylosis are at increased risk of vertebral fracture after minor accidents. Regardless of the initial report of clinical symptoms it is mandatory to perform appropriate imaging procedures usually including MRI.

Percutaneous disc decompression with nucleoplasty-volumetry of the nucleus pulposus using ultrahigh-field MRI

PURPOSE

To evaluate changes in nucleus pulposus volume as a potential parameter for the effects of disc decompression.

METHODS

Fifty-two discs (T8 to L1) were extracted from 26 pigs and separated into thoracic (T8 to T11) and thoracolumbar discs (T12 to L1). The discs were imaged using 7.1 Tesla ultrahigh-field magnetic resonance imaging (MRI) with acquisition of axial T2-weighted turbo spin-echo sequences for determination of baseline and postinterventional nucleus pulposus volumes. Volumes were calculated using OsiriX® (http://www.osirix-viewer.com). After randomization, one group was treated with nucleoplasty, while the placebo group was treated with an identical procedure but without coblation current. The readers analyzing the MR images were blinded to the kind of procedure performed. Baseline and postinterventional volumes were compared between the nucleoplasty and placebo group.

RESULTS

Average preinterventional nucleus volume was 0.799 (SD: 0.212) ml. Postinterventional volume reduction in the nucleoplasty group was significant at 0.052 (SD: 0.035) ml or 6.30% (p<0.0001) (thoracic discs) and 0.082 (SD: 0.042) ml or 7.25% (p = 0.0078) (thoracolumbar discs). Nucleoplasty achieved volume reductions of 0.114 (SD: 0.054) ml or 14.72% (thoracic) and 0.093 (SD: 0.081) ml or 11.61% (thoracolumbar) compared with the placebo group.

CONCLUSIONS

Nucleoplasty significantly reduces thoracic and thoracolumbar nucleus pulposus volumes in porcine discs.

Full-endoscopic Operations of the Spine in Disk Herniations and Spinal Stenosis

Degenerative constrictions of the spinal canal with compression of neural elements arise as a result of bony, disk, capsular, or ligament structures. The most frequent causes are disk herniations and spinal stenoses. The lumbar and cervical spine is the most prominent cause. After conservative treatments have been exhausted, surgical intervention may be necessary. Today, microsurgical, microscopically assisted decompression is regarded as the standard procedure for disk herniation and spinal stenosis in the lumbar region, while in the cervical spine microsurgical, microscopically assisted anterior decompression and fusion are standard. Both procedures demonstrate good clinical results but present problems associated with the operation. Decompressions in the area of the spine must be carried out under continuous visualization and must entail the possibility of adequate bone resection. Taking this into account, completely new endoscopes and instrument sets were developed for full-endoscopic operations in tandem with the development of the lateral transforaminal and interlaminar approaches for the lumbar spine and the posterior and contralateral anterior approaches for the cervical spine. The possibilities and results of comparable, established standard procedures were used as a benchmark in the course of clinical validation. The development of surgically created approaches and the new rod lens endoscopes combined with appropriate instrument sets have laid the technical foundations for full-endoscopic operation in the lumbar spine on all primary and recurrent disk herniations inside and outside the spinal canal and on spinal stenoses. This development has also permitted resection of soft disk herniations in the cervical spine. The use of the relevant approaches depends on anatomical and pathological inclusion and exclusion criteria. The clinical results of standard procedures are achieved, which must be regarded as a minimum criterion for the introduction of new technologies. On the basis of EBM criteria, it can be established that using the full-endoscopic techniques developed, adequate decompression is achieved in the defined indications with reduced traumatization, improved visibility conditions, and positive cost benefits. Today, full-endoscopic operations may be regarded as an expansion and alternative within the overall concept of spinal surgery.

Surgical treatment for lumbar lateral recess stenosis with the full-endoscopic interlaminar approach versus conventional microsurgical technique: a prospective, randomized, controlled study

OBJECT

Extensive decompression with laminectomy where appropriate is often still described as the method of choice in surgery for lateral recess stenosis. Nonetheless, tissue-sparing procedures are becoming more common. Endoscopic techniques have become the standard in many areas because of the advantages they offer in surgical technique and in rehabilitation. Transforaminal and interlaminar access provide 2 full-endoscopic (FE) techniques for lumbar spine surgery. The goal of this prospective randomized controlled study was to compare the surgical results for the FE technique via the interlaminar approach with those of the conventional microsurgical technique in patients with degenerative lateral recess stenosis.

METHODS

A total of 161 patients with FE or microsurgical decompression underwent follow-up for 2 years. In addition to general and specific parameters, the following measuring instruments were used: visual analog scale, German version of the North American Spine Society instrument, and the Oswestry low-back pain disability questionnaire.

RESULTS

The results show that 74.5% of patients reported no longer having leg pain, and 20.5% had only occasional pain. The clinical results were the same in both groups. The rate of complications and revisions was significantly reduced in the FE group. The FE techniques brought advantages in the following areas: operation, complications, traumatization, and rehabilitation.

CONCLUSIONS

The clinical results of the FE interlaminar technique are equal to those of the microsurgical technique. At the same time, there are advantages in the operation technique, such as reduced traumatization. The FE interlaminar spinal decompression procedure is a sufficient and safe supplement and alternative to microsurgical procedures.

Result of full endoscopic uniportal lumbar discectomy: preliminary report

OBJECTIVE

Several techniques of minimal invasive spinal surgery are now becoming common roles in the treatment of spinal diseases in many spinal centers. In the present report, the authors present a retrospective, cohort evaluation of 46 consecutive patients who underwent full endoscopic lumbar discectomy. The purpose of the present report was to present outcomes in this initial series of patients and to present outlines of the operative technique; the full endoscopic uniportal lumbar discectomy. The present research is the first preliminary report in Thailand to analyze and evaluate this new surgical technique.

MATERIAL AND METHOD

Forty-six lumbar disc herniation operations were performed in two spinal centers between February and June 2008, using the full endoscopic uniportal with Vertebris instrumentation system. The operations were carried out by interlaminar and transforaminal approach using an 8 mm-diameter uniportal endoscopy of Vertebris instrumentation. The outcome was clinically assessed, on immediate post-operation and one month after surgery, by using Visual Analogue Scale (VAS), the Thai Version of the modified Oswestry disability index (ODI) questionnaire (version 1.0), and modified McNab criteria.

RESULTS

Excellent and good outcome was achieved in 87.4% of patients from Modified McNab criteria. Forty-three patients (93.5%) had significant improvement of sciatic pain immediately after the operation. Eight postoperative complications were demonstrated and discussed.

CONCLUSION

Full endoscopic uniportal lumbar discectomy is a novel and effective minimally invasive spinal surgical technique. However, the technique requires surgical skill training and experience.

Use of newly developed instruments and endoscopes: full-endoscopic resection of lumbar disc herniations via the interlaminar and lateral transforaminal approach

OBJECT

Even with good results, conventional disc operations may result in subsequent damage due to trauma. Endoscopic techniques have become the standard in many areas because of the advantages they offer intraoperatively and postoperatively in rehabilitation. The goal of this prospective study was to examine the expanded technical possibilities of full-endoscopic transforaminal and interlaminar resection of herniated lumbar discs in which the authors used newly developed optics and instruments. The focus was on questions of achieving sufficient decompression, as well as the advantages and disadvantages of the minimally invasive procedure.

METHODS

Two hundred thirty-two patients underwent follow up for 2 years after undergoing surgery. In addition to general and specific parameters, the following measuring instruments were used: a visual analog scale, the German version of the North American Spine Society instrument, and the Oswestry Disability Index of low-back pain disability. Postoperatively 84% of the patients no longer had leg pain, and 12% had only occasional pain. The results of decompression were equivalent to those of conventional procedures. The incidence of traumatization was reduced. Epidural scarring was minimized. The recurrence rate was 6.0%. No serious surgical complications were observed. Resection of the herniated disc was technically possible in all cases in which the new instruments were used.

CONCLUSIONS

The authors view the aforedescribed techniques, which offer the advantages of a truly minimally invasive procedure, as a sufficient and safe supplementation and alternative to conventional procedures, when the appropriate indication criteria are heeded. The new endoscope with its 4.2-mm working channel and corresponding instruments significantly reduced the technical problems.

Use of newly developed instruments and endoscopes: full-endoscopic resection of lumbar disc herniations via the interlaminar and lateral transforaminal approach

OBJECT

Even with good results, conventional disc operations may result in subsequent damage due to trauma. Endoscopic techniques have become the standard in many areas because of the advantages they offer intraoperatively and postoperatively in rehabilitation. The goal of this prospective study was to examine the expanded technical possibilities of full-endoscopic transforaminal and interlaminar resection of herniated lumbar discs in which the authors used newly developed optics and instruments. The focus was on questions of achieving sufficient decompression, as well as the advantages and disadvantages of the minimally invasive procedure.

METHODS

Two hundred thirty-two patients underwent follow up for 2 years after undergoing surgery. In addition to general and specific parameters, the following measuring instruments were used: a visual analog scale, the German version of the North American Spine Society instrument, and the Oswestry Disability Index of low-back pain disability. Postoperatively 84% of the patients no longer had leg pain, and 12% had only occasional pain. The results of decompression were equivalent to those of conventional procedures. The incidence of traumatization was reduced. Epidural scarring was minimized. The recurrence rate was 6.0%. No serious surgical complications were observed. Resection of the herniated disc was technically possible in all cases in which the new instruments were used.

CONCLUSIONS

The authors view the aforedescribed techniques, which offer the advantages of a truly minimally invasive procedure, as a sufficient and safe supplementation and alternative to conventional procedures, when the appropriate indication criteria are heeded. The new endoscope with its 4.2-mm working channel and corresponding instruments significantly reduced the technical problems.

A New full-endoscopic technique for the interlaminar operation of lumbar disc herniations using 6-mm endoscopes: prospective 2-year results of 331 patients

Even with good results, conventional disc operations may result in consecutive damage due to traumatisation. Endoscopic techniques have become the standard in many areas because of the advantages they offer in surgical technique and in rehabilitation. The transforaminal operation is the most common full-endoscopic procedure in surgery of the lumbar spine. It is frequently necessary to reach the spinal canal directly in order to achieve sufficient resection of lumbar disc herniations. Even in using a lateral approach, the authors recognise the clear limitations of the transforaminal procedure. The objective of this prospective study was to examine the technical possibility of a full-endoscopic interlaminar access. The focus was on questions of sufficient decompression, as well as advantages and disadvantages of the minimally invasive procedure. 331 patients were followed for 2 years. The results show that 82 % reported no longer having leg pain, and 13 % had only occasional pain. The decompression results are equivalent to those of conventional procedures. Traumatisation of both the access pathway and the spinal canal structures was reduced. Epidural scarring was minimised. The recurrence rate was 2.4 %. No serious surgical complications were observed. The authors view the technique described, which offers the advantage of a truly minimally invasive procedure, as a sufficient and safe alternative to conventional procedures, when the appropriate indication criteria are heeded. There are technical problems because of the small instruments. In conjunction with the transforaminal procedure, this is an expansion of the spectrum for full-endoscopic surgery of lumbar disc herniations.

An extreme lateral access for the surgery of lumbar disc herniations inside the spinal canal using the full-endoscopic uniportal transforaminal approach-technique and prospective results of 463 patients

STUDY DESIGN

Prospective study of patients with lumbar disc herniations who were operated on with a full-endoscopic uniportal transforaminal approach using an extreme lateral access.

OBJECTIVES

To examine the technical possibilities of an extreme lateral access for full-endoscopic uniportal transforaminal surgery of lumbar disc herniations within the spinal canal. Also, to assess sufficient decompression, and the advantages and disadvantages of the minimally invasive procedure.

SUMMARY OF BACKGROUND DATA

Conventional prolapsed disc operations can result in consecutive damage as a result of traumatization. The usual transforaminal access is posterolateral, and is associated with problems in reaching the epidural space directly with unhindered vision and, thus, with problems of sufficient decompression in lumbar disc herniations within the spinal canal.

METHODS

A total of 463 patients were observed for 1 year. In addition to general and specific parameters, the following measuring instruments were used: visual analog scale, German version North American Spine Society Instrumentarium, Oswestry low back pain disability questionnaire.

RESULTS

There were no complications. Of the patients, 81% reported no longer having leg pain, and 14% had occasional pain. There was no worsening. The results were constant and are equal to those of conventional procedures. No patients presented with neural scarring; 7% had recurrence of the prolapse. The extreme lateral access was necessary to reach the sequestered material.

CONCLUSIONS

The technique presented is an adequate and safe alternative to conventional procedures, and has the advantages of a truly minimally invasive procedure. The extreme lateral access is required for the indications described. There are clear limitations outside these indications. The possibility of selecting an access from posterolateral to extreme lateral now enables surgery of lumbar disc herniations inside and outside the spinal canal.

Endoscopic surgery of the lumbar epidural space (epiduroscopy): results of therapeutic intervention in 93 patients

Determination and therapy of the underlying pathology in chronic pain syndrome in the lumbar spine is frequently difficult. Minimally invasive and microsurgical techniques may offer advantages. Epiduroscopy is available for visualization of the lumbar epidural space. 93 patients with chronic back-leg pain syndrome were epiduroscopically operated. When findings were appropriate, mechanical instruments and the holmium:YAG laser were applied therapeutically. 45.9 % of these patients presented with positive results in postoperative examination. Pathomorphological processes corresponding to the multifactorial pain processes, which escape detection in modern imaging procedures, can be diagnosed in the epidural space using epiduroscopy Therapeutic intervention is basically possible. However, use is limited due to technical difficulties. Navigation of the endoscope is especially limited in access via the hiatus sacralis.

Application of holmium:YAG laser in epiduroscopy: extended practicabilities in the treatment of chronic back pain syndrome

OBJECTIVE

Minimally invasive and endoscopic techniques offer advantages in the treatment of chronic back pain syndrome and may provide for expanded indications and visualization. Epiduroscopy for the visualization of the epidural space still is burdened with technical problems. The mechanical instruments now available, coupled with the narrow working canal, result in marked limitations. The aim of this study was to assess the possibilities and technical requisites for the use of the holmium:YAG laser in lumbar epiduroscopy.

BACKGROUND DATA

Epiduroscopy has been used for visualization of the lumbar epidural space since the 1930s. Studies have been performed to evaluate the effects and possibilities of epiduroscopy in chronic back pain. Most of them only describe the anatomical aspects.

MATERIALS AND METHODS

Forty-seven patients were epiduroscopied and treated, for findings of corresponding epidural adhesions, with the holmium:YAG laser. The examinations concentrated on the general applicability of the holmium:YAG laser in epiduroscopy and the technical parameters necessary for this procedure. The clinical evaluation of therapy was made prospectively in comparison with the preoperative status and compared to already recorded groups in previous studies.

RESULTS

Bending behavior without negative impact of the epiduroscope was only attained with laser fibers less than 300 microm, so a fiber with a diameter of 265 microm was used as the standard. The minimum energy output of the laser required for an adequate ablative effect was 0.8 J at a frequency of 8 Hz. The total energy output was 0.256-1.4 kJ. Complications did not occur intraoperatively nor following the procedure. The follow-up examinations showed no deterioration of the complaints in any patient. There was no occurrence of relevant laser-related edemas or adhesions. The proportion of painful conditions that could be positively influenced corresponded to that in a control group treated only by mechanical means.

CONCLUSION

The results show that the holmium:YAG laser considerably expands therapeutic possibilities and aids in solving the technical problems of epiduroscopy. No negative effects occurred when the laser is used.

[Epiduroscopic diagnosis and treatment of epidural adhesions in chronic back pain syndrome of patients with previous surgical treatment: first results of 31 interventions]

AIM

Scars in the epidural space play an important role in the chronic lumbar pain syndrome of patients with previous surgical treatment. The results of surgical resection are frequently unsatisfactory. Discrepancies to imaging diagnostics are conspicuous. These are known from experience with endoscopic operations. Minimal adhesions may promote pain. Epiduroscopy is available for visualization of the epidural space. The objective of this study was to examine its possibilities in patients with previous surgical treatment.

METHOD

31 patients with chronic lumbar pain syndrome who had previously received surgical treatment were operated epiduroscopically. Mechanical instruments and the holmium:YAG laser were used for epidural adhesion.

RESULTS

All patients showed adhesions. 24 patients also presented with adhesions on the contralateral side. There were marked discrepancies between imaging and intraoperative findings. The use of mechanical instruments was limited. The use of laser fibers resulted in greater possibilities. Back pain could be better influenced than leg pain. The procedure was limited by still-existing technical problems.

CONCLUSION

Epiduroscopy offers a novel view of this compartment. Minimal adhesions which are not visible in imaging ean promote pain. They can be partially diagnosed and treated by epiduroscopy. There are still marked limitations to epiduroscopy due to technical problems. These must be minimized.