The anterior-to-psoas approach for interbody fusion at the L5-S1 segment: clinical and radiological outcomes

An Update in Complication Rates Associated With Anterior Lumbar Surgery: A Systematic Review and Meta-Analysis

STUDY DESIGN

Systematic Review and meta-analysis.

OBJECTIVE

To conduct an updated systematic review and meta-analysis of complications associated with different anterior fusion techniques/approaches and adjuvant resources (i.e., computed tomography angiography (CTA), rhBMP-2, and access surgeons).

METHODS

A systematic review was conducted from 1/1/2014-4/1/2024 for studies evaluating the incidence of complications associated with anterior lumbar procedures. Comparisons of complications were made between surgical approach, use of CTA, rhBMP-2, and access surgeons. Meta-analyses were conducted using a generalized linear mixed model.

RESULTS

54 studies were included in the final analysis with 8066 patients and an average follow-up of 31.2 months. The overall complication rate associated with anterior lumbar surgery was 13.1%, including an intraoperative complication rate of 3.8%, postoperative complication rate of 7.4%, infection rate of 1.5%, and reoperation rate of 1.7%. Forest plot analysis showed no significant difference in overall complication rates between open and mini-open techniques, although mini-open techniques were associated with lower overall reoperation rates. The use of CTA was associated with an increase in intraoperative and overall complications, and the use of an access surgeon was associated with a decreased risk of reoperation. The use of rhBMP-2 was not associated with overall complication risk.

CONCLUSIONS

While anterior lumbar surgery provides numerous benefits, surgeons and patients alike should be aware of the complication and safety profile prior to surgery. High quality studies are warranted to help elucidate the true benefit of certain techniques and adjuvant resources in reducing complications.

The Alternative Approach to the Lumbosacral Segment: The Right-Sided Oblique Lumbar Interbody Fusion Compared with Anterior Lumbar Interbody Fusion

BACKGROUND

Anterior lumbar interbody fusion with dorsal percutaneous pedicle screw fixation (ALIF+D) is a well-described technique treating lumbosacral degenerative diseases. Mobilizing the common iliac arteries and veins during the ALIF+D approach may increase the risk of bleeding when the bifurcations are low. This study demonstrates that in such cases, the right-sided oblique lumbar interbody fusion with dorsal percutaneous pedicle screw fixation (OLIF+D) offers a novel alternative to the ALIF+D approach.

METHODS

Twenty-one patients were operated on with the ALIF+D approach, and 20 patients were operated on using the right-sided OLIF+D technique. Computed tomography-based imaging and clinical data, such as patient-reported outcomes, were collected.

RESULTS

Both ALIF+D and OLIF+D surgeries elicited a statistically significant decrease (P ≤ 0.001) between the preoperative and postoperative Oswestry disability index and the back and leg pain visual analog scale scores. A significant increase was observed in both techniques between preoperative and postoperative anterior segmental height, posterior segmental height, and segmental lordosis (P ≤ 0.001). There were no statistically significant postoperative differences between patients operated by ALIF+D and patients operated by OLIF+D in the segmental lordosis angle (P = 0.354), anterior segmental height (P = 0.297), posterior segmental height (P = 0.404), Oswestry disability index (P = 0.824), or back and leg visual analog scale scores (P = 0.682 and P = 0.979, respectively). The OLIF+D group showed trend-like higher blood loss (198 ± 118 mL vs. 134 ± 77 mL; P = 0.058) and significantly longer surgical time (199 ± 47 vs. 169 ± 54 minutes; P = 0.009) compared to the ALIF+D group.

CONCLUSIONS

The right-sided lumbosacral OLIF+D approach is an alternative to the ALIF+D approach if the latter is hazardous due to vessel anatomy.

Stand-Alone Percutaneous Pedicle Screw Lumbar Fixation to Indirectly Decompress the Neural Elements in Spinal Stenosis: A Radiographic Assessment Case Series

BACKGROUND

 The ideal surgical treatment of lumbar canal stenosis remains controversial. Although decompressive open surgery has been widely used with good clinical outcome, minimally invasive indirect decompression techniques have been developed to avoid the complications associated with open approaches. The purpose of this study was to evaluate the radiologic outcome and safety of the indirect decompression achieved with stand-alone percutaneous pedicle screw fixation in the surgical treatment of lumbar degenerative pathologies.

METHODS

 Twenty-eight patients presenting with spinal degenerative diseases including concomitant central and/or lateral stenosis were treated with stand-alone percutaneous pedicle screw fixation. Radiographic measurements were made on axial and sagittal magnetic resonance (MR) images, performed before surgery and after a mean follow-up period of 25.2 months. Measurements included spinal canal and foraminal areas, and anteroposterior canal diameter.

RESULTS

 Percutaneous screw fixation was performed in 35 spinal levels. Measurements on the follow-up MR images showed statistically significant increase in the cross-sectional area of the spinal canal and the neural foramen, from a mean of 88.22 and 61.05 mm2 preoperatively to 141.52 and 92.18 mm2 at final follow-up, respectively. The sagittal central canal diameter increased from a mean of 4.9 to 9.1 mm at final follow-up. Visual analog scale (VAS) pain score and Oswestry Disability Index (ODI) both improved significantly after surgery (p < 0.0001).

CONCLUSION

 Stand-alone percutaneous pedicle screw fixation is a safe and effective technique for indirect decompression of the spinal canal and neural foramina in lumbar degenerative diseases. This minimally invasive technique may provide the necessary decompression in cases of common degenerative lumbar disorders with ligamentous stenosis.

A novel surgical approach using the "lateral corridor" for minimally invasive oblique lumbar interbody fusion at L5-S1: a clinical series and technical note

PURPOSE

The minimally invasive oblique lumbar interbody fusion (MI-OLIF) L5-S1 was introduced to overcome the limitations of conventional fusion techniques, however, MI-OLIF is not possible using the standard method due to vascular structures in some cases. We aimed to introduce the "lateral corridor" and report the details of the surgical technique with a clinical case series.

METHODS

We utilized the lateral access route of the left common iliac vein and named it the "lateral corridor", to distinguish the technique from the standard technique (central corridor). The type and frequency of branch vessels that required additional manipulations were reviewed, and the frequency of intraoperative vascular injury was investigated.

RESULTS

Among the 107 patients who underwent MI-OLIF L5-S1, 26 patients (24.3%) who received the "lateral corridor" technique were included. Branch vessel ligation was required in 42.3% of the patients. The types of branch vessels that required ligation were seven cases (26.9%) of the iliolumbar vein (ILV) and six cases (23.1%) of ascending lumbar vein (ALV). The ILV and ALV were ligated in two cases. None of the patients developed intraoperative vascular injuries.

CONCLUSION

We introduced the "lateral corridor" as an alternative approach for MI-OLIF L5-S1, implemented it in 24.3% of the patient cohort, and reported favorable outcomes devoid of vascular complications. The "lateral corridor" necessitated ligation of the ILV or ALV in 42.3% of cases. The "lateral corridor" approach appears to be a promising surgical technique, offering feasibility even in instances where the vascular anatomy precludes the employment of the conventional approach.

New Axially Expandable Oblique Cage Designed for Anterior to Psoas (ATP) Approach: Indications-Surgical Technique and Clinical-Radiological Outcomes in Patients with Symptomatic Degenerative Disc Disease

Background: Standard oblique cages cannot cover endplates side-to-side, which is an important biomechanical factor for reducing the risk of cage subsidence and for restoring correct segmental lordosis. The aim of this study is to evaluate the radiological and clinical results of a new oblique lumbar interbody fusion (OLIF) axially expandable cage. Methods: This is a prospective observational case-control study. From March 2018 to June 2020, 28 consecutive patients with lumbar degenerative disease underwent an ATP approach, with the insertion of a new axially expandable cage, which was used as a stand-alone procedure or followed by posterior percutaneous pedicle fixation. Results: Twenty-eight patients in both groups met the inclusion criteria. The mean follow-up time was 31.2 months (range of 13-37). The clinical results were not significantly different, although in the control group, two major intraoperative complications were recorded, and slight improvements in ODI and SF-36 scores were observed in the study group. The radiological results showed a less frequent incidence of subsidence and a higher rate of fusion in the study group compared to controls. Conclusions: The axially expandable oblique cage for lumbar inter body fusion, specifically designed for the ATP approach, represents an innovation and a technical improvement. The insertion and the axial expansion technique are safe and easy. The large footprint could obtain solid and effective arthrodesis, potentially reducing the risk of subsidence.

The anatomical feasibility of anterior intra- and extra-bifurcation approaches to L5-S1: an anatomic study based on lumbar MRI

BACKGROUND CONTEXT

The anterior approach at L5-S1 has many advantages, however, vascular complications are challenging for spinal surgeons who may not be familiar with the variability of vascular anatomy. There are three different anterior approaches (intra-bifurcation approach and extra-bifurcation: left-, and right-sided prepsoas approaches) described in previous studies to respond to the variability of anterior vascular anatomy for reduction in vascular injury, while no guidance for the choice of approach preoperatively.

PURPOSE

To analyze the anatomical feasibility of three anterior approaches to access the L5-S1 disc space according to a practical framework.

STUDY DESIGN

Retrospective study.

PATIENT SAMPLE

Lumbar magnetic resonance imaging (MRI) from patients who visited our outpatient clinic were reviewed, with 150 cases meeting the inclusion criteria.

OUTCOME MEASURES

The following radiographic parameters were measured on axial T2-weighted MRI at the lower endplate of L5 and the upper endplate of S1: width of the vascular corridor, position of the left and right common iliac vein (CIV), and presence of perivascular adipose tissue (PAT). Moreover, we designed a safe line to evaluate the feasibility of left- and right-sided prepsoas approaches. Cases of lumbosacral transitional vertebrae were identified.

METHODS

The feasibility of the intra-bifurcation approach was determined by the width of the vascular corridor, presence of PAT, and the position of the CIV. The feasibility of the prepsoas approach was determined by the relative position of the CIV to the safe line, presence of PAT, and the intersection point of the CIV and vertebral body.

RESULTS

Sixty-eight percent, 64.7%, and 75.3% cases allowed the intra-bifurcation, left-, and right-sided prepsoas approach to L5-S1, respectively. The cases in this study had at least one of three anterior approaches to access L5-S1 disc space, and 74% of cases had more than one anatomical feasibility of anterior approach. The right-sided prepsoas approach was feasible in the majority of cases because of the vertical course of the right CIV with a significantly higher proportion of presence of PAT. Patients with lumbosacral transitional vertebrae (24 cases) may prefer the prepsoas approaches, and only six cases (25.0%) were determined to be feasible for the intra-bifurcation approach.

CONCLUSIONS

Our study proposes a practical framework to determine whether the three different anterior approaches are feasible access at L5-S1. According to the framework, all cases had the anatomical feasibility of using an anterior approach to access L5-S1, and three-fourths of cases had a replaceable anterior approach when encountering intraoperative difficulties.

Stand-Alone Oblique Lumbar Interbody Fusion (OLIF) for the Treatment of Adjacent Segment Disease (ASD) after Previous Posterior Lumbar Fusion: Clinical and Radiological Outcomes and Comparison with Posterior Revision Surgery

Background: Radiological evidence of adjacent segment disease (ASD) has been reported to have a prevalence of more than 30% and several risk factors have been reported. The aim of this study is to evaluate the clinical and radiological outcomes of patients with symptomatic ASD treated with stand-alone OLIF and compare results with a posterior revision surgery cohort. Methods: This is a retrospective case-control study. Clinical-patient-reported outcomes were obtained at preoperative, postoperative and final follow-up visits using the Short Form (SF-36) scale, the Oswestry Disability Index (ODI) and the visual analog scale (VAS). Radiological measures include lumbar lordosis (LL), segmental lordosis (SL), pelvic incidence-lumbar lordosis (PI-LL) mismatch, segmental coronal Cobb angle and intervertebral disc height (DH). The data are compared with a retrospective series of patients that underwent a posterior revision surgery for ASD. Results: Twenty-eight patients in the OLIF group and 25 patients in the posterior group meet inclusion criteria. The mean ages at the time of the surgery are 65.1 years and 67.5, respectively. The mean follow-up time is 36.1 months (range of 14-56). The clinical outcomes significantly improve from preoperative values from the surgery in both groups. The radiological parameters are significantly improved postoperatively and were maintained at the last follow-up in both groups. A statistically significant difference is observed between the two groups for minor complication rate, length of surgery, blood loss and DH restoration. Conclusions: Stand-alone OLIF is an effective and safe technique with low morbidity and complication rates for the treatment of selected patients with symptomatic ASD following a previous lumbar fusion.

Anterior To Psoas lumbar and lumbosacral combined with posterior reconstruction in Adult Spinal Deformity: A bicentric European study

Introduction

Lateral lumbar fusion via the trans-psoas approach is popular in adult deformity reconstruction. To overcome its limitations (neurological damage to the plexus and lack of applicability to the lumbosacral junction), a modified anterior-to-psoas (ATP) approach has been described and used.

Research question

To investigate the results of ATP lumbar and lumbosacral fusion, in a cohort of adult patients treated with combined anteroposterior approaches for adult spinal deformity (ASD).

Materials and methods

ASD patients surgically treated at two tertiary spinal centres were followed up. Forty patients were treated with combined ATP and posterior surgery: 11 with open lumbar lateral interbody-fusions (lumbotomy LLIF) and 29 with lesser invasive oblique lateral interbody-fusions (OLIF). Preoperative demographics, aetiology, clinical characteristics, and spinopelvic parameters were comparable between the two cohorts.

Results

At a minimum 2-year follow-up, both cohorts showed significant improvements in patient reported outcome measures (PROMs), i.e. Visual Analogue Scale and Core Outcome Measures Index, as well as radiological parameters, with no significant differences based on the type of surgical approach. No significant differences were found in major (P ​= ​0.457) and minor (P ​= ​0.071) complications between the two cohorts.

Discusson and conclusion

Anterolateral lumbar interbody fusions, whether performed via a direct or oblique approach, proved to be safe and effective adjuvants to posterior surgery in patients with ASD. No significant complication differences were noted between techniques. In addition, the anterior-to-psoas approaches limited the risks of post-operative pseudoarthrosis by providing solid anterior support to lumbar and lumbosacral segments, demonstrating a positive impact on PROMS.

OLIF versus ALIF: Which is the better surgical approach for degenerative lumbar disease? A systematic review

PURPOSE

The aim of this study was to compare the clinical and radiographical outcomes between OLIF and ALIF in treating lumbar degenerative diseases.

METHODS

We searched PubMed, Embase, Web of Science, and Cochrane Library for relevant studies. Changes in disc height (DH), segmental lordosis angle (SLA), lumbar lordosis (LL), visual analogue scale (VAS) score, and Oswestry disability index (ODI) between baseline and final follow-up, along with other important surgical outcomes, were assessed and analysed. Data on the global fusion rate and main complications were collected and compared.

RESULTS

Approximately, 2041 patients from 36 studies were included, consisting of 1057 patients who underwent OLIF and 984 patients who underwent ALIF. The results reveal no significant difference in DH, SLA, VAS score, and ODI between the two groups (all P > 0.05). The operation time, estimated blood loss, and length of hospital stay were also comparable between the two groups. Over 90% of the fusion rate was achieved in both groups. The OLIF group showed a higher complication rate than the ALIF group (OLIF 18.83% vs ALIF 7.32%).

CONCLUSIONS

OLIF leads to a higher complication rate, with the most notable complication being cage subsidence. Both OLIF and ALIF are effective treatments for degenerative lumbar diseases and have similar therapeutic effects. ALIF was expected to be more expensive for patients because of the necessity of involving vascular surgeons.

Radiographic comparison of L5-S1 lateral anterior lumbar interbody fusion cage subsidence and displacement by fixation strategy: anterior plate versus integrated screws

OBJECTIVE

The aim of this study was to radiographically compare cage subsidence and displacement between L5-S1 lateral anterior lumbar interbody fusion (ALIF) cages secured with an anterior buttress plate and cages secured with integrated screws.

METHODS

Consecutive patients who underwent L5-S1 lateral ALIF with supplemental posterior fixation by a single surgeon from June 2016 to January 2021 were reviewed. Radiographs were analyzed and compared between the two groups based on the type of fixation used to secure the L5-S1 lateral ALIF cage: 1) anterior buttress plate or 2) integrated screws. The following measurements at L5-S1 were analyzed on radiographs obtained preoperatively, before discharge, and at latest follow-up: 1) anterior disc height, 2) posterior disc height, and 3) segmental lordosis. Cage subsidence and anterior cage displacement were determined radiographically.

RESULTS

One hundred thirty-nine patients (mean age 60.0 ± 14.3 years) were included for analysis. Sixty-eight patients were treated with an anterior buttress plate (mean follow-up 12 ± 5 months), and 71 were treated with integrated screws (mean follow-up 9 ± 3 months). Mean age, sex distribution, preoperative L5-S1 lordosis, preoperative L5-S1 anterior disc height, and preoperative L5-S1 posterior disc height were statistically similar between the two groups. After surgery, the segmental L5-S1 lordosis and L5-S1 anterior disc heights significantly improved for both groups, and each respective measurement was similar between the groups at final follow-up. Posterior disc heights significantly increased after surgery with integrated screws but not with the anterior buttress plate. As such, posterior disc heights were significantly greater at final follow-up for integrated screws. Compared with patients who received integrated screws, significantly more patients who received the anterior buttress plate had cage subsidence cranially through the L5 endplate (20.6% vs 2.8%, p < 0.01), cage subsidence caudally through the S1 endplate (27.9% vs 0%, p < 0.01), and anterior cage displacement (22.1% vs 0%, p < 0.01).

CONCLUSIONS

In this radiographic analysis of 139 patients who underwent lateral L5-S1 ALIF supplemented by posterior fixation, L5-S1 cages secured with an anterior buttress plate demonstrated significantly higher rates of cage subsidence and anterior cage displacement compared with cages secured with integrated screws. While the more durable stability afforded by cages secured with integrated screws suggests that they may be a more viable fixation strategy for L5-S1 lateral ALIFs, there are multiple factors that can contribute to cage subsidence, and, thus, definitive presumption cannot be made that the findings of this study are directly related to the buttress plate.

Lumbar interbody fusion using oblique (OLIF) and lateral (LLIF) approaches for degenerative spine disorders: a meta-analysis of the comparative studies

STUDY DESIGN

Systematic review and meta-analysis.

OBJECTIVE

Historically, posterior approaches to the lumbar spine have allowed surgeons to manage degenerative conditions affecting the lumbar spine. However, spinal muscles injury, post-surgical vertebral instability, cerebrospinal fluid (CSF) leakage, and failed back surgery syndrome (FBSS) represent severe complications that may occur after these surgeries. Lumbar interbody fusion using anterior (ALIF), oblique (OLIF), or lateral (LLIF) approaches may represent valuable surgical alternatives, in case fusion is indicated on single or multiple levels.

METHODS

The present study is a systematic review, conducted according to the PRISMA statement, of comparative studies on OLIF, and LLIF for degenerative spine disorders, and a meta-analysis of their clinical-radiological outcomes and complications.

RESULTS

After screening 1472 papers on PubMed, Scopus, and Cochrane Library, only 3 papers were included in the present study. 318 patients were included for data meta-analysis, 128 in OLIF group, and 190 in LLIF group. There were no significative differences in terms of surgical (intraoperative blood loss and surgical duration) and clinical (VAS-back, VAS-leg, and ODI scores) outcomes, or fusion rates at last follow-up (> 2 years). Significantly higher rates of abdominal complications, system failure, and vascular injuries were recorded in the OLIF group. Conversely, postoperative neurological symptoms and psoas weakness were significatively more common in LLIF group.

CONCLUSIONS

The meta-analysis suggests that OLIF and LLIF are both effective for lumbar degenerative disorders, although each of them presents specific complications and this should represent a relevant element in the surgical planning.

Oblique lateral interbody fusion in heterogenous lumbar diseases: Anterolateral screw fixation vs. posterior percutaneous pedicle screw fixation - A single center experience

Background

Oblique lateral interbody fusion (OLIF) is a type of minimally invasive lateral lumbar interbody fusion technique used for treating lumbar degenerative diseases. This study aimed to analyze the clinical and radiographic efficacy of OLIF with anterolateral screw fixation alone and OLIF requiring fixation with conventional posterior percutaneous pedicle screws for lumbar diseases.

Methods

Medical records of consecutive patients admitted to Cheng-Hsin Hospital who received OLIF between January 2019 and December 2020 were retrospectively reviewed. Patients were divided into two groups by screw fixation: patients who received anterolateral screw fixation alone were defined as one-stage OLIF (n = 9) and patients who received fixation with conventional posterior percutaneous pedicle screw were defined as two-stage OLIF (n = 16). Patient clinical characteristics, medical history, intraoperative blood loss, length of hospital stay, peri-operative, and post-operative complications were evaluated in all patients.

Results

During the study period, a total of 25 patients were successfully treated with OLIF (n = 9 one-stage; n = 16 two-stage). Two-stage OLIF was associated with longer operation times, longer hospital stays, shorter bed-rest time, and a greater likelihood of having a blood transfusion compared with the one-stage OLIF group. A higher proportion of grade I subsidence was observed at 6 months and 1 year after surgery in the two-stage group compared with the one-stage group. Post-operative complications included ileus, dystonia, and dystonia were higher in the two-stage OLIF group. Improvements in radiographic parameters were demonstrated after OLIF, and the improvements were comparable between one-stage and two-stage OLIF.

Conclusions

One-stage OLIF is a feasible and efficacious treatment method for single- and multiple-level degenerative lumbar diseases. Additional clinical follow-up is necessary to confirm long-term outcomes.

Extreme lateral interbody fusion (XLIF) approach for L5-S1: Preliminary experience

Study Design

Technical report.

Objective

Evaluate technical feasibility of extreme lateral interbody fusion (XLIF) at the L5-S1 level and provide an elaborate description of the surgical technique.

Summary of Background Data

With the development of surgical techniques, the indications for oblique lumbar interbody fusion (OLIF) surgery have been broadened to the L5/S1 segment. However, this technique also has limitations. Different from OLIF, the L5/S1 segment used to be considered the main contraindication for XLIF. To date, no authors have reported the application of XLIF at the L5/S1 level.

Methods

Only patients whose preoperative lumbar MRI showed the position of the psoas major muscles and blood vessels at the L5/S1 level were similar to those seen at supra-L5 levels were seleted. By folding the operating table, the iliac crest was moved downward to expose the L5/S1 intervertebral space during the operation. The remaining surgical procedures were consistent with routine XLIF surgery.

Results

8 patients successfully underwent XLIF at the L5/S1 level. The L5/S1 disk spaces were always exposed sufficiently for disk preparation and cage insertion. The post operative radiographs showed a satisfactory L5/S1 reconstruction with good cage position. Only 1 patient (12.5%) felt thigh numbness, and the symptoms gradually resolved after surgery and were no longer present in a month. There were no cases of psoas hematoma, retrograde ejaculation or vascular injury. The postoperative VAS score showed that all the patients achieved satisfactory results.

Conclusions

XLIF at L5-S1 is feasible in strictly selected cases after thorough preoperative preparation and careful intraoperative procedures. However, we did not recommend XLIF as a routine surgical option at the L5/S1 level.

The Morphological Changes in Adjacent Segments Amongst Patients Receiving Anterior and Oblique Lumbar Interbody Fusion: A Retrospective Study

Adjacent segment disease (ASD) is troublesome condition that has proved to be highly related to spinal malalignment after spinal surgery. Hence, we aimed to evaluate the morphological changes after anterior lumbar interbody fusion (ALIF) and oblique LIF (OLIF) to establish the differences between the two surgical methods in terms of possible ASD avoidance. Fifty patients, half of whom received ALIF while the other half received OLIF, were analyzed with image studies and functional outcomes during the pre-operative and post-operative periods, and 2 years after surgery. Image measurements obtained included spinal-pelvic parameters, index lordosis (IL), segmental lordosis (SL), anterior disc height (ADH), posterior disc height (PDH) and adjacent segment disc angle (ASDA). The ADH and PDH in the adjacent segment decreased in the two groups while OLIF showed greater decrease without radiological ASD noted at 2-year follow-up. Both groups showed an increase in IL after surgery while ALIF showed greater improvement. No statistical difference was identified in functional outcomes between LIFs. We suggest that both ALIF and OLIF can restore adequate lordosis and prevent ASD after surgery. However, it should be noted that patient selection remains crucial when making any decision involving which of the two methods to use.