Minimally invasive lumbar spinal fusion

Two-year clinical and radiographic success of minimally invasive lateral transpsoas approach for the treatment of degenerative lumbar conditions

Background

The lateral transpsoas approach to interbody fusion is a less disruptive but direct-visualization approach for anterior/anterolateral fusion of the thoracolumbar spine. Several reports have detailed the technique, the safety of the approach, and the short term clinical benefits. However, no published studies to date have reported the long term clinical and radiographic success of the procedure.

Materials and methods

The current study is a retrospective chart review of prospectively collected clinical and radiographic outcomes in 62 patients having undergone the Anterolateral transpsoas procedure at a single institution for anterior column stabilization as treatment for degenerative conditions, including degenerative disk disease, spondylolisthesis, scoliosis, and stenosis. Only patients who were a minimum of 2 years postoperative were included in this evaluation. Clinical outcomes measured included visual analog pain scales (VAS) and Oswestry disability index (ODI). Radiographic outcomes included identification of successful arthrodesis.

Results

Sixty-two patients were treated with lateral interbody fusion between 2003 and December 2006. Twenty-six patients (42%) were single-level, 13 (21%) 2-level, and 23 (37%) 3- or more levels. Forty-five (73%) included supplemental posterior pedicle fixation, 4 (6%) lateral fixation, and 13 (21%) were stand-alone. Pain scores (VAS) decreased significantly from preoperative to 2 years follow-up by 37% (P < .0001). Functional scores (ODI) decreased significantly by 39% from preoperative to 2 years follow-up (P < .0001). Clinical success by ODI-change definition was achieved in 71% of patients. Radiographic success was achieved in 91% of patients, with 1 patient with pseudarthrosis requiring posterior revision.

Conclusion

The lateral transpsoas approach is similar to a traditional anterior lumbar interbody fusion, in that access is obtained through a retroperitoneal, direct-visualization exposure, and a large implant can be placed in the interspace to achieve disk height and alignment correction. The 2 years plus clinical and radiographic success rates are similar to or better than those reported for traditional anterior and posterior approach procedures, which, coupled with significant short-term benefits of minimal morbidity, make the lateral approach a safe and effective treatment option for anterior/anterolateral lumbar fusions.

Fusion after minimally disruptive anterior lumbar interbody fusion: Analysis of extreme lateral interbody fusion by computed tomography

BACKGROUND

Less invasive fusion approaches, such as extreme lateral interbody fusion (XLIF), have proliferated, but few reports have critically assessed fusion rates. To date, no studies have reported computed tomography (CT) documented fusion rates following XLIF.

METHODS

An institutional review board-approved prospective radiographic and CT assessment of minimally disruptive anterior lumbar interbody fusion (mini-ALIF) fusions performed through the XLIF approach. Sixty-six patients (88 operative levels) were examined 12 months after XLIF to determine the rate and quality of anterior lumbar fusion.

RESULTS

Eighty five of the 88 levels (96.6%) were judged fused by CT. Sixty-four of the 66 patients (97.0%) were judged fused by CT. Patient satisfaction at 12 months after surgery was high, with 89.4% reportedly "satisfied or very satisfied" with their results. No revisions were necessary for pseudarthrosis.

CONCLUSION

Mini-ALIF using an XLIF approach reliably results in anterior lumbar fusion.

Resident learning curve for minimal-access transforaminal lumbar interbody fusion in a military training program

Object

Minimal-access transforaminal lumbar interbody fusion (TLIF) has gained popularity as a method of achieving interbody fusion via a posterior-only approach with the aim of minimizing injury to adjacent tissue. While many studies have reported successful outcomes, questions remain regarding the potential learning curve for successfully completing this procedure. The goal of this study, based on a single resident's experience at the only Accreditation Council for Graduate Medical Education–approved neurosurgical training center in the US military, was to determine if there is in fact a significant learning curve in performing a minimal-access TLIF.

Methods

The authors retrospectively reviewed all minimal-access TLIFs performed by a single neurosurgical resident between July 2006 and January 2008. Minimal-access TLIFs were performed using a tubular retractor inserted via a muscle-dilating exposure to limit approach-related morbidity. The accuracy of screw placement and operative times were assessed.

Results

A single resident/attending team performed 28 minimal-access TLIF procedures. In total, 65 screws were placed at L-2 (1 screw), L-3 (2 screws), L-4 (18 screws), L-5 (27 screws), and S-1 (17 screws) from the resident's perspective. Postoperative CTs were reviewed to determine the accuracy of screw placement. An accuracy of 95.4% (62 of 65) properly placed screws was noted on postoperative imaging. Two screws (at L-5 in the patient in Case 17 and at S-1 in the patient in Case 9) were lateral, and no revision was needed. One screw (at L-4 in Case 24) was 1 mm medial without symptoms or the need for revision. In evaluating the operative times, 2 deformity cases (Grade III spondylolisthesis) were excluded. The average operating time per level in the remaining 26 cases was 113.25 minutes. The average time per level for the first 13 cases was 121.2 minutes; the amount of time decreased to 105.3 minutes for the second group of 13 cases (p = 0.25).

Conclusions

In summary, minimal-access TLIF can be safely performed in a training environment without a significant complication rate due to the expected learning curve.

Mid-term to long-term clinical and functional outcomes of minimally invasive correction and fusion for adults with scoliosis

Object

The goal of this study was to assess the operative outcomes of adult patients with scoliosis who were treated surgically with minimally invasive correction and fusion.

Methods

This was a retrospective study of 28 consecutive patients who underwent minimally invasive correction and fusion over 3 or more levels for adult scoliosis. Hospital and office charts were reviewed for clinical data. Functional outcome data were collected at each visit and at the last follow-up through self-administered questionnaires. All radiological measurements were obtained using standardized computer measuring tools.

Results

The mean age of the patients in the study was 67.7 years (range 22–81 years), with a mean follow-up time of 22 months (range 13–37 months). Estimated blood loss for anterior procedures (transpsoas discectomy and interbody fusions) was 241 ml (range 20–2000 ml). Estimated blood loss for posterior procedures, including L5–S1 transsacral interbody fusion (and in some cases L4–5 and L5–S1 transsacral interbody fusion) and percutaneous screw fixation, was 231 ml (range 50–400 ml). The mean operating time, which was recorded from incision time to closure, was 232 minutes (range 104–448 minutes) for the anterior procedures, and for posterior procedures it was 248 minutes (range 141–370 minutes). The mean length of hospital stay was 10 days (range 3–20 days). The preoperative Cobb angle was 22° (range 15–62°), which corrected to 7° (range 0–22°). All patients maintained correction of their deformity and were noted to have solid arthrodesis on plain radiographs. This was further confirmed on CT scans in 21 patients. The mean preoperative visual analog scale and treatment intensity scale scores were 7.05 and 53.5; postoperatively these were 3.03 and 25.88, respectively. The mean preoperative 36-Item Short Form Health Survey and Oswestry Disability Index scores were 55.73 and 39.13; postoperatively they were 61.50 and 7, respectively. In terms of major complications, 2 patients had quadriceps palsies from which they recovered within 6 months, 1 sustained a retrocapsular renal hematoma, and 1 patient had an unrelated cerebellar hemorrhage.

Conclusions

Minimally invasive surgical correction of adult scoliosis results in mid- to long-term outcomes similar to traditional surgical approaches. Whereas operating times are comparable to those achieved with open approaches, blood loss and morbidity appear to be significantly lower in patients undergoing minimally invasive deformity correction. This approach may be particularly useful in the elderly.

Early outcomes and safety of the minimally invasive, lateral retroperitoneal transpsoas approach for adult degenerative scoliosis

Object

The object of this study was to evaluate an alternative surgical approach to degenerative thoracolumbar deformity in adults. The authors present their early experience with the minimally invasive, lateral retroperitoneal transpsoas approach for placing interbody grafts and providing anterior column support for adult degenerative deformity.

Methods

The authors retrospectively reviewed a prospectively acquired database of all patients with adult thoracolumbar degenerative deformity treated with the minimally invasive, lateral retroperitoneal transpsoas approach at our institution. All patient data were recorded including demographics, preoperative evaluation, procedure used, postoperative follow-up, operative time, blood loss, length of hospital stay, and complications. The Oswestry Disability Index and visual analog scale (for pain) were also administered pre- and postoperatively as early outcome measures. All patients were scheduled for follow-up postoperatively at weeks 2, 6, 12, and 24, and at 1 year.

Results

The authors identified 25 patients with adult degenerative deformity who were treated using the minimally invasive, lateral retroperitoneal transpsoas approach. All patients underwent discectomy and lateral interbody graft placement for anterior column support and interbody fusion. The mean total blood loss was 53 ml per level. The average length of stay in the hospital was 6.2 days. Mean follow-up was 11 months (range 3–20 months). A mean improvement of 5.7 points on visual analog scale scores and 23.7% on the Oswestry Disability Index was observed. Perioperative complications include 1 patient with rhabdomyolysis requiring temporary hemodialysis, 1 patient with subsidence, and 1 patient with hardware failure. Three patients (12%) experienced transient postoperative anterior thigh numbness, ipsilateral to the side of approach. In this series, 20 patients (80%) were identified who had more than 6 months of follow-up and radiographic evidence of fusion. The minimally invasive, lateral retroperitoneal transpsoas approach, without the use of osteotomies, did not correct the sagittal balance in approximately one-third of the patients.

Conclusions

Degenerative scoliosis of the adult spine is secondary to asymmetrical degeneration of the discs. Surgical decompression and correction of the deformity can be performed from an anterior, posterior, or combined approach. These procedures are often associated with long operative times and a high incidence of complications. The authors' experience with the minimally invasive, lateral retroperitoneal transpsoas approach for placement of a large interbody graft for anterior column support, restoration of disc height, arthrodesis, and realignment is a feasible alternative to these procedures.

Perioperative and short-term advantages of mini-open approach for lumbar spinal fusion

It has been widely reported a vascular and neurologic damage of the lumbar muscles produced in the classic posterior approach for lumbar spinal fusions. The purpose of this study is to demonstrate a better clinical and functional outcome in the postoperative and short term in patients undergoing minimal invasive surgery ("mini-open") for this lumbar spinal arthrodesis. We designed a prospective study with a 30 individuals cohort randomized in two groups, depending on the approach performed to get a instrumented lumbar circumferential arthrodesis: "classic posterior" (CL group) or "mini-open" approach (MO group). Several clinical and functional parameters were assessed, including blood loss, postoperative pain, analgesic requirements and daily life activities during hospital stay and at the 3-month follow-up. Patients of the "mini-open approach" group had a significant lower blood loss and hospital stay during admission. They also had significant lower analgesic requirements and faster recovery of daily life activities (specially moderate efforts) when compared to the patients of the "classic posterior approach" group. No significant differences were found between two groups in surgery timing, X-rays exposure or sciatic postoperative pain. This study, inline with previous investigations, reinforces the concept of minimizing the muscular lumbar damage with a mini-open approach for a faster and better recovery of patients' disability in the short term. Further investigations are necessary to confirm these findings in the long term, and to verify the achievement of a stable lumbar spinal fusion.

Minimally invasive multilevel percutaneous correction and fusion for adult lumbar degenerative scoliosis: a technique and feasibility study

STUDY DESIGN

Prospective evaluation of 12 patients undergoing surgery for lumbar degenerative scoliosis.

OBJECTIVE

To assess the feasibility of minimally invasive spine surgery (MIS) techniques in the correction of lumbar degenerative deformity.

SUMMARY OF BACKGROUND DATA

Patient age, comorbidities, and blood loss may be limiting factors when considering surgical correction of lumbar degenerative scoliosis. MIS may allow for significantly less blood loss and tissue disruption than open surgery.

METHODS

Twelve patients underwent circumferential fusion. The age range of these patients was 50 to 85 years (mean of 72.8 y). Of the 12 patients, 7 were men and 5 were women. All patients underwent direct lateral transpsoas approach for discectomy and fusion with polyetheretherketone cage and rh-BMP2. All fusions to the sacrum included L5-S1 fusion with the Trans1 Axial Lumbar Interbody Fusion technique. Posteriorly, multilevel percutaneous screws were inserted using the CD Horizon Longitude system. Radiographs, visual analog scores (VAS), and treatment intensity scores (TIS) were assessed preoperatively and at last postoperative visit. Operative times and estimated blood loss were recorded.

RESULTS

Mean number of segments operated on was 3.64 (range: 2 to 8 segments). Mean blood loss for anterior procedures (transpsoas discectomy/fusion and in some cases L5-S1 interbody fusion) was 163.89 mL (SD 105.41) and for posterior percutaneous pedicle screw fixation (and in some cases L5-S1 interbody fusion) was 93.33 mL (SD 101.43). Mean surgical time for anterior procedures was 4.01 hours (SD 1.88) and for posterior procedures was 3.99 hours (SD 1.19). Mean Cobb angle preoperatively was 18.93 degrees (SD 10.48) and postoperatively was 6.19 degrees (SD 7.20). Mean preoperative VAS score was 7.1; mean preoperative TIS score was 56.0. At mean follow-up of 75.5 days, mean VAS was 4.8; TIS was 28.0.

CONCLUSIONS

A combination of 3 MIS techniques allows for correction of lumbar degenerative scoliosis. Multisegment correction can be performed with less blood loss and morbidity than for open correction.

Maximizing the potential of minimally invasive spine surgery in complex spinal disorders

Minimally invasive surgery (MIS) in the spine was primarily developed to reduce approach-related morbidity and to improve clinical outcomes compared with those following conventional open spine surgery. Over the past several years, minimally invasive spinal procedures have gained recognition and their utilization has increased. In particular, MIS is now routinely used in the treatment of degenerative spine disorders and has been shown to be as effective as conventional open spine surgeries. Although the procedures are not yet widely recognized in the context of complex spine surgery, the true potential in minimizing approach-related morbidity is far greater in the treatment of complex spinal diseases such as spinal trauma, spinal deformities, and spinal oncology. Conventional open spine surgeries for complex spinal disorders are often associated with significant soft tissue disruption, blood loss, prolonged recovery time, and postsurgical pain. In this article the authors review numerous cases of complex spine disorders managed with MIS techniques and discuss the current and future implications of these approaches for complex spinal pathologies.