Endoscopic transiliac approach to L5-S1 disc and foramen. A cadaver study

Minimally Invasive Approaches for Lumbosacral Plexus Schwannomas

BACKGROUND AND OBJECTIVES

Lumbosacral plexus schwannomas (LSPSs) are benign, slow-growing tumors that arise from the myelin sheath of the lumbar or sacral plexus nerves. Surgery is the treatment of choice for symptomatic LSPSs. Conventional retroperitoneal or transabdominal approaches provide wide exposure of the lesion but are often associated with complications in the abdominal wall, lumbar or sacral plexus, ureter, and intraperitoneal organs. Advances in technology and minimally invasive (MIS) techniques have provided alternative approaches with reliable efficacy compared with traditional open surgery. We describe 3 MIS approaches using tubular retractor systems according to the lesion level.

METHODS

This was a multicenter, retrospective observational cohort study to evaluate the use of MIS tubular approaches for surgical resection of LSPSs. We included 23 lumbar and upper sacral plexus schwannomas. Clinical presentation, spinal level, surgical duration, degree of resection, days of hospitalization, pathological anatomy of the tumor, approach-related surgical difficulties, and outcomes were collected.

RESULTS

The posterior oblique approach was used in 43.5% of the cases, the transpsoas approach in 39.1%, and the transiliac in 17.4%. The mean operative time was 3.3 hours, and the mean hospitalization was 2.5 days. All tumors were WHO grade 1 schwannoma. Postoperative MRI confirms gross total resection in 91.3% of the patients. No patient requires instrumentation. The pros and cons of each approach were summarized.

CONCLUSION

The MIS approaches adapted to the lumbar level may improve surgeons' comfort allowing a safe resection of retroperitoneal LSPS.

[Research progress of unilateral biportal endoscopy technique in treatment of lumbar related diseases]

Objective

To review the application and research progress of unilateral biportal endoscopy (UBE) technique in the treatment of lumbar related diseases.

Methods

The domestic and foreign literature on the application of UBE technique in the treatment of lumbar related diseases was extensively consulted, and the development history, clinical application, operation points and precautions, related complications and adverse reactions, advantages and disadvantages of the technique were reviewed.

Results

As a minimally invasive technique developed in recent years, UBE technique is effective in the treatment of lumbar spinal stenosis caused by different causes, with satisfactory decompression effect, less damage, and good lumbar stability. UBE technique has significant advantages over open surgery and microscopy-assisted surgery in the treatment of lumbar disc herniation. In the treatment of lumbar spondylolisthesis, the postoperative trauma of UBE technique is less than that of conventional surgery, and the fusion rate is satisfactory. There are also complications such as spinal cord injury, spinal epidural hematoma, incomplete decompression or recurrence, nerve root irritation symptoms, and postoperative infection in the treatment of lumbar related diseases with UBE technique. Detailed preoperative planning is essential for patients with lumbar related diseases who are suitable for UBE surgery.

Conclusion

UBE technique is easy to operate, has a gentle learning curve, can use conventional instruments, and has definite effectiveness. It is suitable for a variety of lumbar related diseases, but there are some defects and deficiencies.

[Brief history, global trends, and Chinese mission of unilateral biportal endoscopy technique]

The current unilateral biportal endoscopy (UBE) technique was originated from Argentina and developed in South Korea, which was rapidly growing and popularizing in China. The adoption of spinal endoscopy, using small cameras placed inside body with continuous water irrigation, providing better surgical field with less tissue dissection and quicker recovery for patients. As with other disciplines, the use of spinal endoscopy in spinal surgery will become increasingly widespread. UBE technique will promote the popularization of spinal endoscopy in China with monoportal endoscopy technique. At the same time, biportal endoscopy has better expansibility, the application of accessory incision may provide solution for more complicated spinal disease. Chinese spine surgeon should better understand the trends in spinal endoscopy, seize the opportunity of the rapidly evolving in spinal healthcare, and to promote the popularization of UBE across the globe.

Impact of Body Weight, Height, and Obesity on Selection of Skin Entry Point for Transforaminal Endoscopic Lumbar Discectomy

Background Prospective evaluation of the effect of physical parameters like height, weight and abdominal girth on different skin entry points in transforaminal endoscopic lumbar discectomy (TELD) in lower lumbar discs.

Methods This prospective study involved 174 patients with unilateral radicular pain or discogenic back pain, central, paracentral disc herniations and lateral canal stenosis at the level from L3 to S1 radiologically confirmed by magnetic resonance imaging (MRI) and failed conservative trial for 6 weeks. All patients underwent measurements of height, weight, body mass index (BMI), and abdominal girth preoperatively. All the four possible entry points, i.e., 45 to 45, posterolateral (PL), tip of spinous process (TOSP), and dorsum of the facet joint, were marked and point midway between PL and TOSP (PL-TOSP) skin entry was used.

Results The change in the value, i.e., distance from midline of all the entry points with physical parameters like height, weight, BMI, and abdominal circumference was statistically significant. The visual analog scale score decreased from a preoperative value of 7.98 to 1.84 at 6 months follow-up. The Oswestry disability index score improved from 72.53 to 16.26.

Conclusion The entry point in TELD is not a fixed value as it varies with the physical parameters like weight and abdominal girth of the patient. PL-TOSP is a safe entry point for common pathologies like central, paracentral herniations and lateral canal stenosis in lower lumbar levels and can be predicted preoperatively by proposed formula.

Anatomic Image-Based Classification of Lumbar Intervertebral Disc Pathologies

Introduction

Several minimally invasive spine approaches and techniques have been developed in recent years. While the disease processes affecting the spinal motion segment have remained largely the same, the emerging technologies have changed treatment options radically and not necessarily in an organized fashion. The current diagnostic techniques, also evolving, have helped us appreciate the disease's pathoanatomy in minute details. A comprehensive classification method accounting for all anatomical variations in the disc disease, tailored to treatment options, is necessary. Such a classification will allow the surgeon to choose an appropriate surgical option in a consistent fashion. We feel that our classification system will help the spine surgeon make that important decision consistently, with minimal risk of leaving behind a significant lesion or disrupting an otherwise normal structure of the spinal motion segment. Furthermore, we feel such a comprehensive classification will help surgeons and other caregivers to standardize treatment approaches to the various presentations of disc disease, and apply the evolving technology in an organized fashion.

Purpose

To develop a comprehensive, treatment-orientated classification of the lumbar disc disease.

Materials and Methods

The literature was reviewed for the classification of disc disease. The morphology of the disc disease, the topography of the disc lesion, and the symptom-complex produced by the disc lesion are identified and graded. The features so identified and graded are placed in a matrix. The combinations of the anatomical features and symptoms are then computed as shown in the matrix. The MRI database held in the office was studied to determine the most frequent combinations of the disc disease and symptom complex.

Results

A total of 494 combinations were identified, but most have no clinical relevance. The retrospective study of the clinical data and MRI studies of 93 patients (50 male and 43 female) revealed the most affected motion-segment was L5-S1 (male = 19.3%, and female = 23.8%). The most common patho-anatomy is a globally bulging disc (T3L1), representing 37.6% of the total. The second most common combination is a degenerated disc with central, intra-annular tear T4L1), representing 20.4% of the total. At 11.8%, globally bulging with severe axial pain and moderate radicular pain represented the most common patho-anatomic/clinical classification (T3L1B4R2). The most frequent top 10 patho-anatomic/clinical classifications represented 15.5% of the total.

Conclusion

In light of the multiple surgical options for excision of the herniated lumbar disc, including the conventional and minimally invasive, and the fact that the imaging technology allows spine surgeons to see in great detail, the disease status of each of the components of the spinal motion segment, it is imperative to develop comprehensive classification systems which take account of the unique characteristics of the disease entity and guide treatment strategies. The classification system presented here is fairly complex, but the software technology will be utilized for the classification system along with the most appropriate treatment approach.

Risk Factors for Recurrent L5-S1 Disc Herniation After Percutaneous Endoscopic Transforaminal Discectomy: A Retrospective Study

Background

This retrospective study aimed to investigate the risk factors associated with the recurrence of L5–S1 disc herniation after percutaneous endoscopic transforaminal discectomy (PETD).

Material/Methods

There were 484 patients L5–S1 disc herniation who underwent PETD who were divided into the recurrence group (n=46) and the non-recurrence group (n=438). Transforaminal endoscopic approaches included modifications of the Yeung endoscopy spine system (YESS) (the intraforaminal intradiscal approach) and the transforaminal endoscopic spine system (TESSYS) (intraforaminal extradiscal approach). Demographic and clinical characteristics and imaging data were analyzed. The two study groups were compared to determine the factors associated with the recurrence of L5–S1 disc herniation. The patients underwent postoperative follow-up for between one and four years.

Results

At follow-up, 9.504% of patients (46/484) with the recurrence of L5–S1 disc herniation following PETD when compared with the non-recurrence group showed no significant difference for time to return to work, gender, history of diabetes mellitus, trauma, duration of symptoms, smoking and alcohol history, hypertension, location of disc herniation, transverse process length, intervertebral space height, and pelvic incidence angle (P>0.05). However, age, body mass index (BMI), the degree of disc degeneration, sagittal range of motion, lumbar lordosis angle, and sacral slope were significantly associated with the recurrence of L5–S1 disc herniation following PETD (P<0.05). Logistic regression analysis supported these main associations.

Conclusions

The recurrence of L5–S1 disc herniation following PETD was significantly associated with increased age and BMI, more severe disc degeneration, increased sagittal range of motion, increased lumbar lordosis, and sacral slope.

Suprailiac versus transiliac approach in transforaminal endoscopic discectomy at L5-S1: a new surgical classification of L5-iliac crest relationship and guidelines for approach

Background

Approach to the L5-S1 level with transforaminal access can be challenging. Some surgeons employ the interlaminar or paraspinal endoscopic approach as an alternative apart from the other minimally invasive posterior surgical options. To precisely target and safely access disc herniations at L5-S1, the authors attempted to stratify patients into trans and supra iliac approach groups and propose a simple surgical classification based on the radiographic findings.

Methods

A prospective study was performed on a cohort of 90 patients with L5-S1 disc herniation who underwent transforaminal endoscopic discectomy through suprailiac or transiliac approach depending on the best trajectory to access the herniated disc. Preoperative radiological assessment was done on anteroposterior and lateral radiographs of the lumbosacral spine by two independent observers. The proposed classification and approach guidelines were used to stratify patients for the preferred access route. The outcome was measured as mean VAS and ODI scores pre-operative and at 6 months post-operative and compared using the null hypothesis (P value) and the paired t-test. The interrater reliability was calculated as the percentage agreement between different observers.

Results

The L5-S1 disc herniation was treated with the transforaminal approach in 46 patients via the suprailiac and in the remaining 44 patients via the transiliac approach. There were statistically significant VAS and ODI reductions in patients of both groups (P<0.05). Interrater reliability of 92.5% using percent agreement shows strong level of agreement.

Conclusions

This surgical approach classification based on radiographs aids in the preoperative planning for selection of patients to either suprailiac or transiliac approach for transforaminal endoscopic surgery at L5-S1 level.

Posterior resection of fifth lumbar giant schwannoma combined with a recapping transiliac approach: case report and technical note

A two-stage combined anterior and posterior approach is commonly used for total resection of giant spinal tumors. However, an anterior approach at the lower lumbar level is technically challenging because of the anatomy of the iliac wing, major vessels and nerves of the lumbosacral plexus. We report a case of fifth vertebral tumor treated posteriorly with a newly devised surgical procedure combined with a recapping transiliac approach. A 45-year-old female diagnosed with giant schwannoma of the fifth lumbar vertebra underwent single-stage posterior tumor resection combined with osteotomy of the lateral part of the iliac crest. Without an anterior approach, tumor excision was completed with a wide view into the fifth lumbar vertebral body. Autogenous bone graft was harvested and used to treat the bone defect. The resected iliac bone was recapped and fixed with screws. The patient was monitored for 8 years without recurrence, and postoperative lumbar alignment remained unchanged. This surgical procedure is safe and a useful adjunct approach for posterior total resection of giant spinal tumors at the lower lumbar level.

Application of transiliac approach to intervertebral endoscopic discectomy in L5/S1 intervertebral disc herniation

Objective

To discuss the significance and the short-term effect of bone puncture technique in transiliac approach to intervertebral endoscopic discectomy for the treatment of L5/S1 intervertebral disc herniation.

Methods

Nineteen patients were diagnosed as L5/S1 disc herniation and treated using transiliac approach to endoscopic discectomy (group I), and 20 patients were diagnosed as non-L5/S1 disc herniation and underwent conventional approach (group R). Leg pain was evaluated by VAS. MacNab ratings of the last follow-up were recorded to evaluate early clinical efficacy, and postoperative complications were recorded to evaluate surgical safety. The imaging changes of the patients 3 months after surgery were observed.

Results

One patient in group I, who felt abnormal in nerve roots, underwent symptomatic treatments, such as rehydration and hormone, and the abnormalities disappeared 3 days after treatment. There were no significant significances in operative time and intraoperative fluoroscopy times between groups I and R (p > 0.05), but there was a higher tendency in group I. The VAS scores of post-operation were significantly lower than that of pre-operation in the two groups (p < 0.05), but there were no significant differences between the two groups (p > 0.05). The MacNab score of the last follow-up showed excellent rate (95%) and good rate (90%) in groups I and R, respectively.

Conclusions

Bone puncture-combined transiliac approach to intervertebral endoscopic surgery could locate iliac puncture point individually, and establish a good iliac channel, which is safe, effective, and minimally invasive.

Endoscopic trans-iliac approach to L5-S1 disc and foramen - a report on clinical experience

BACKGROUND

The lumbosacral junction is a difficult area for spine surgery because of the complex anatomy. In the era of minimally invasive spine surgery, the presence of the iliac wing has, at the level of lumbosacral junction, created a major obstacle in the paths of two of the major approaches, namely, the direct lateral and percutaneous posterolateral endoscopic approaches. A trans-iliac cadaver study published by the senior author and co-workers in 1997, suggested the possibility of an alternative approach to the lumbosacral junction.

PURPOSE

To determine the feasibility of percutaneous, endoscopic trans-iliac approach to the L5-S1 disc and foramen.

STUDY DESIGN

Prospective case series study.

MATERIALS AND METHODS

15 consecutive patients undergoing the transiliac approach to L5-S1 disc and foramen were included in the study. Pre- and postoperative visual analogue scale (VAS); Oswestry Disability Index (ODI); and intra-operative blood loss and operative time, were obtained for the study. Preoperative MRI or CT scan was used to determine the need for trans-iliac access. The procedure was performed with the patient in prone position and under monitored sedation for decompression. Endotracheal anesthesia was used for fusion cases. The transiliac access was established with a cannulated drill or core drill through the iliac wing. Once the trans-iliac window had been created, the rest of the procedure proceeded as for percutaneous endoscopic transforaminal decompression and fusion.

RESULTS

15 patients (9 male and 6 female) participated in the study. The VAS for back and leg pain significantly improved in all patients. The ODI dropped by more than 50%. There was minimal blood loss, and transient post-operative dysesthesia in 2 cases which resolved after 3 weeks.

CONCLUSION

Endoscopic trans-iliac approach to the L5-S1 disc and foramen is feasible and safe. Decompression can be performed safely via trans-iliac access with minimal blood loss, and in a short operative time.

The "inside out" transforaminal technique to treat lumbar spinal pain in an awake and aware patient under local anesthesia: results and a review of the literature

Surgical management of back and leg pain is evolving and changing due to a better understanding of the patho-anatomy well correlated with its pathophysiology. Pain is better understood with in vivo visualization and probing of the pain generators using an endoscopic access rather than just relying on symptoms diagram and image correlation. This has resulted in a shared decision making involving patient and surgeon, focused on a broader spectrum of surgical as well as non-surgical treatments, and not just masking the pain generator. It has moved away from decisions based on diagnostic images alone, that, while noting the image alterations, cannot explain the pain experienced by each individual as images do not always show variations in nerve supply and patho-anatomy. The ability to isolate and visualize "pain" generators in the foramen and treating persistent pain by visualizing inflammation and compression of nerves, serves as the basis for transforaminal endoscopic (TFE) surgery. This has also resulted in better pre surgical planning with more specific and defined goals in mind. The "Inside out" philosophy of TFE surgery is safe and precise. It provides basic access to the disc and foramen to cover a large spectrum of painful pathologies.

Endoscopic transforaminal decompression, interbody fusion, and percutaneous pedicle screw implantation of the lumbar spine: A case series report

Background

On the basis of the experiences gained from conventional open spinal procedures, a long list of desirable objectives have emerged with the evolution of the lesser invasive spinal procedures. At the top of that list is the desire to minimize the trauma of surgery. The rest of the objectives, which include reductions of operating time, surgical blood loss, hospital stay, postoperative narcotic medication, convalescence, complication rates, and escalating health care costs, as well as the desire of elderly patients to continue rigorous physical activities, largely depend on the ability to minimize the trauma of surgery. The purpose of this study was to investigate the feasibility of the least invasive lumbar decompression, interbody fusion and percutaneous pedicle screw implantation, to minimize surgical trauma without compromising the quality of the treatment outcome, as well as to minimize risk of complications.

Methods

In this case series, 60 patients with diagnoses of degenerative disc disease, degenerative motion segments with stenosis, and spondylolisthesis, in whom nonoperative treatments failed, were treated with endoscopic transforaminal decompression and interbody fusion by 1 surgeon in 2 centers. The outcome measures were as follows: operating time, intraoperative blood loss, hospital stay, Visual Analogue Scale (VAS) scores for back and leg pain, scores on the Roland-Morris Disability Questionnaire, and postoperative imaging studies. A consecutive series of patients who met the treatment criteria completed VAS forms and Roland-Morris questionnaires preoperatively. Surgical procedures included arthroscopic decompression of the foramina and the discs; endplate preparation and implantation of allograft bone chips and bone morphogenetic protein 2 on absorbable collagen sponge into the disc space; and percutaneous implantation of pedicle screws. Postoperatively, the patients again completed the VAS forms and Roland-Morris questionnaires. Their charts were reviewed for office notes, operative notes, hospital stay, medications, and imaging studies. The latest X-ray and computed tomography scan films were reviewed and analyzed. Patients were followed up for a minimum of 6 months. The literature was reviewed for comparison of outcomes.

Results

Sixty patients met the inclusion criteria. The mean age was 52.8 years. The duration of illness averaged 5 years. Follow-up ranged from 6 to 25 months, with a mean of 12 months. Preoperative diagnoses included degenerative disc disease, degenerative motion segments with stenosis, and spondylolisthesis. The mean time in the operating room was 2 hours 54 minutes. Estimated blood loss averaged 57.6 mL. The duration of the hospital stay averaged 2.6 days. Preoperative back pain and leg pain were significantly reduced (P < .005). Forty-seven imaging studies obtained at the last visit, including X-ray and computed tomography scans, showed solid fusion in 28 patients (59.6%), stable fixation in 17 (36.2%), and osteolysis around the pedicle screws in 2 (4.2%). All patients had improvement of motor function, whereas 2 patients complained of residual numbness. In addition, 8 patients (13%) complained of residual discomfort on extension of the lumbar spine. Two patients had pedicle screw–related complications requiring surgery. A review of the literature showed that endoscopic transforaminal decompression and interbody fusion performed better than open transforaminal lumbar interbody fusion/posterior lumbar interbody fusion, minimally invasive transforaminal lumbar interbody fusion, and extreme lateral lumbar interbody fusion, with regard to most parameters studied.

Conclusions

The endoscopic transforaminal lumbar decompression, interbody fusion, and percutaneous pedicle screw instrumentation consistently produced satisfactory results in all demographics. It performed better than the alternative procedures for most parameters studied.

Minimally invasive lateral lumbar interbody fusion and transpsoas approach–related morbidity

Object

Recently, the minimally invasive, lateral retroperitoneal, transpsoas approach to the thoracolumbar spinal column has been described by various authors. This is known as the minimally invasive lateral lumbar interbody fusion. The purpose of this study is to elucidate the approach-related morbidity associated with the minimally invasive transpsoas approach to the lumbar spine. To date, there have been only a couple of reports regarding the morbidity of the transpsoas muscle approach.

Methods

A nonrandomized, prospective study utilizing a self-reported patient questionnaire was conducted between January 2006 and June 2008 at Northwestern University. Data were collected in 53 patients with a follow-up period ranging from 6 months to 3.5 years. Only 2 patients were lost to follow-up.

Results

Thirty-six percent (19 of 53) of patients reported subjective hip flexor weakness, 25% (13 of 53) anterior thigh numbness, and 23% (12 of 53) anterior thigh pain. However, 84% of the 19 patients reported complete resolution of their subjective hip flexor weakness by 6 months, and most experienced improved strength by 8 weeks. Of those reporting anterior thigh numbness and pain, 69% and 75% improved to their baseline function by the 6-month follow-up evaluations, respectively. All patients with self-reported subjective hip flexor weakness underwent examinations during subsequent clinic visits after surgery; however, these examinations did not confirm a motor deficit less than Grade 5. Subset analysis showed that the L3–4 and L4–5 levels were most often affected.

Conclusions

The minimally invasive, transpsoas muscle approach to the lumbar spine has a number of advantages. The data show that a percentage of the patients undergoing the transpsoas approach will have temporary sensory and motor symptoms related to this approach. The majority of the symptoms are thought to be related to psoas muscle inflammation and/or stretch injury to the genitofemoral nerve due to the surgical corridor traversed during the operation. No major injuries to the lumbar plexus were encountered. It is important to educate patients prior to surgery of the possibility of these largely transient symptoms.

Percutaneous endoscopic lumbar discectomy by transiliac approach: a case report

STUDY DESIGN

Case report.

OBJECTIVE

The authors report a new percutaneous endoscopic lumbar discectomy (PELD) technique for the treatment of lumbar disc herniation with a high iliac crest via a transiliac approach.

SUMMARY OF BACKGROUND DATA

When the iliac crest is high, the L4-L5 and L5-S1 disc spaces are located deep in the pelvis, so they are not easily accessible via a suprailiac route.

METHODS

A 51-year-old man manifested left gluteal and leg pain due to an up-migrated soft disc herniation at the L4-L5 level. Transforaminal PELD via a transiliac approach was performed to remove the herniated fragment, achieving complete decompression of the nerve root.

RESULTS

The symptom was relieved and the patient was discharged the next day.

CONCLUSION

When a conventional transforaminal PELD is impossible due to the presence of a high iliac crest, PELD via a transiliac route could be a alternative option in selected cases.

Minimally invasive lumbar spinal fusion

Minimally invasive techniques for lumbar spine fusion have been developed in an attempt to decrease the complications related to traditional open exposures (eg, infection, wound healing problems). Anterior minimally invasive procedures include laparoscopic and mini-open anterior lumbar interbody fusion as well as the lateral transpsoas and percutaneous presacral approaches. Posterior techniques typically use a tubular retractor system that avoids the muscle stripping associated with open procedures. These techniques can be applied to both posterior and transforaminal lumbar interbody fusion procedures. Many initial reports have shown similar clinical results in terms of spinal fusion rates for both traditional open and minimally invasive posterior approaches. However, the anterior minimally invasive procedures are often associated with significantly greater incidence of complications and technical difficulty than their associated open approaches. There is a steep learning curve associated with minimally invasive techniques, and surgeons should not expect to master them in the first several cases.

Percutaneous endoscopic interlaminar discectomy for intracanalicular disc herniations at L5-S1 using a rigid working channel endoscope

OBJECTIVE

Percutaneous endoscopic transforaminal discectomy is often used as a minimally invasive procedure for lumbar disc herniation. However, a transforaminal approach posts limitations at the L5-S1 level owing to anatomic constraints, such as a high iliac crest or small intervertebral foramen and especially for migrated large intracanalicular disc herniations. We discuss the procedure and clinical results of percutaneous endoscopic interlaminar discectomy using a rigid working channel endoscope at the L5-S1 level and the relevant surgical anatomy.

METHODS

We performed percutaneous endoscopic discectomy through the interlaminar approach in 67 patients who satisfied our inclusion criteria during the period from March 2002 to November 2002. All procedures were performed under local anesthesia. Under fluoroscopic guidance, we performed discography using indigocarmine mixed with radio-opaque dye. The 6-mm working channel endoscope was then introduced into the epidural space. Herniated disc material was removed using forceps and laser under clear endoscopic visualization. We retrospectively evaluated the 65 cases with more than 1.5 years of follow-up. The patients were evaluated using the visual analogue scale (VAS) and the Oswestry Disability Index (ODI).

RESULTS

VAS for leg pain (preoperative mean, 7.89; postoperative mean, 1.58) and ODI (preoperative mean, 57.43; postoperative mean, 11.52) showed statistically significant (P = 0.00) improvement in their values at the last follow-up examination compared with preoperative scores. Of the study group, 90.8% individuals showed favorable result. The mean hospital stay was 12 hours. The average time to return to work was 6.79 weeks. Complications included two cases of dural injury with cerebrospinal fluid leakage, nine cases of dysesthesia that were transient, and one case of recurrence. Two patients required conversion to open procedure at the initial operation. There was no evidence of infection in any patients.

CONCLUSION

Percutaneous endoscopic interlaminar discectomy is a safe, effective, and minimally invasive procedure for the treatment of intracanalicular disc herniations at the L5-S1 level in properly selected cases, especially when the transforaminal approach is not possible because of anatomic constraints.

Conical working tube: a special device for endoscopic surgery of herniated lumbar discs

Object. The instrumentation for endoscopic discectomy continues to evolve to allow for acceptable clinical outcomes and expanding applications. The authors describe their experience in using a conical working tube equipped with a guide for angular entry of the telescope to perform endoscopic discectomy in patients with lumbar disc herniation.

Methods. Fifty-one patients (38 men and 13 women) with herniated lumbar discs underwent endoscopic lumbar surgery during the past 2.5 years at the authors' institutions. A conical working tube was inserted over sequential coaxial dilators via a muscle-splitting approach. Conventional neurosurgical instruments were used in conjunction with an angled insertion telescope. Endoscopic discectomy was performed at the L1–2 (one case), L3–4 (two cases), L4–5 (32 cases), and L5—S1 (18 cases) levels. The surgical approach was bilateral in two patients: bilateral L4–5 in one, and right L4–5 and left L5—S1 in the other. The remaining patient suffered adjacent two-level (right-sided L4–5 and L5—S1) herniations. Outcome was assessed at a mean of 11 months after surgery by using modified Macnab criteria.

Outcomes were excellent in 46 (90%), fair in three (6%), and poor in two patients (4%). Complications occurred in four patients and included a dural tear in one case, postoperative neurological deterioration in two, and discitis in two; in two of these patients open surgical exploration was required.

Conclusions. A separate angled entry of the telescope shortens the effective length of the working sheath and creates a better working space, thereby allowing greater instrument maneuverability and ability to use conventional neurosurgical instruments. In addition, use of this telescope in other endoscopic procedures reduces overall cost of instrumentation and treatment, and results are comparable to those reported in association with microscopic lumbar discectomy.

Endoscopic lateral transpsoas approach to the lumbar spine

STUDY DESIGN

A description of a novel surgical approach to the lumbar spine and a prospective evaluation of the early surgical outcomes.

OBJECTIVES

Describe the early postoperative results and the operative technique of a new, minimally invasive transpsoas approach for anterior fusion of the lumbar spine that minimizes the risk to large vessels and other critical structures.

SUMMARY OF BACKGROUND DATA

Standard anterior endoscopic approaches to the lumbar spine require mobilization of the great vessels and sympathetic plexus. Vascular injury and retrograde ejaculation are complications clearly associated with this approach. A retroperitoneal, transpsoas approach to the lumbar spine may reduce these risks.

METHODS

From 1996 to 2002, 21 patients (13 females, 8 males; mean age 50.0 years) underwent an endoscopic, retroperitoneal transpsoas approach for exposure of the lumbar spine. Surgical indications included discogenic pain in 14 patients, spinal instability at a level adjacent to a previous fusion in 3 patients, and progressive degenerative scoliosis in 4 patients. Data were reviewed to document the early postoperative results for this procedure. Illustrations were created to clearly describe this approach.

RESULTS

Average operative time for the single level cases was 149 minutes (range 120-170 minutes); blood loss was 150 cc (range 50-650); postoperative hospital stay was 4.1 days. At long-term follow-up, visual analogue scale scores had decreased an average of 5.9. Mean follow-up was 3.1 years (range 2 months-6.0 years). Six patients (30%) experienced paresthesias in the groin/thigh region. Five of these same patients also complained of groin/thigh pain (27%). Two patients had symptoms that lasted longer than 1 month. One patient was converted to a mini-open lateral approach. There were no vascular injuries.

CONCLUSIONS

Early results show the endoscopic lateral transpsoas approach to the lumbar spine to be a safe, minimally invasive method for anterior fusion of the first through the fourth lumbar vertebrae. Although there is a risk of groin/thigh numbness or pain, and these symptoms are mostly transient. This approach allows for exposure of the lumbar spine without mobilization of the great vessels or sympathetic plexus.