Lateral lumbar interbody fusion in revision surgery for restenosis after posterior decompression

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  • 1 Department of Orthopedic Surgery, Showa University, Tokyo;
  • 2 Department of Orthopedic Surgery, Showa University Koto Toyosu Hospital, Tokyo; and
  • 3 Department of Orthopedic Surgery, Showa University Northern Yokohama Hospital, Kanagawa, Japan
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OBJECTIVE

The purpose of this study was to compare the clinical results of revision interbody fusion surgery between lateral lumbar interbody fusion (LLIF) and posterior lumbar interbody fusion (PLIF) or transforaminal lumbar interbody fusion (TLIF) with propensity score (PS) adjustments and to investigate the efficacy of indirect decompression with LLIF in previously decompressed segments on the basis of radiological assessment.

METHODS

A retrospective study of patients who underwent revision surgery for recurrence of neurological symptoms after posterior decompression surgery was performed. Postoperative complications and operative factors were evaluated and compared between LLIF and PLIF/TLIF. Moreover, postoperative improvement in cross-sectional areas (CSAs) in the spinal canal and intervertebral foramen was evaluated in LLIF cases.

RESULTS

A total of 56 patients (21 and 35 cases of LLIF and PLIF/TLIF, respectively) were included. In the univariate analysis, the LLIF group had significantly more endplate injuries (p = 0.03) and neurological deficits (p = 0.042), whereas the PLIF/TLIF group demonstrated significantly more dural tears (p < 0.001), surgical site infections (SSIs) (p = 0.02), and estimated blood loss (EBL) (p < 0.001). After PS adjustments, the LLIF group still showed significantly more endplate injuries (p = 0.03), and the PLIF/TLIF group demonstrated significantly more dural tears (p < 0.001), EBL (p < 0.001), and operating time (p = 0.04). The PLIF/TLIF group showed a trend toward a higher incidence of SSI (p = 0.10). There was no statistically significant difference regarding improvement in the Japanese Orthopaedic Association scores between the 2 surgical procedures (p = 0.77). The CSAs in the spinal canal and foramen were both significantly improved (p < 0.001).

CONCLUSIONS

LLIF is a safe, effective, and less invasive procedure with acceptable complication rates for revision surgery for previously decompressed segments. Therefore, LLIF can be an alternative to PLIF/TLIF for restenosis after posterior decompression surgery.

ABBREVIATIONS ASA-PS = American Society of Anesthesiologists Physical Status Classification System; CCI = Charlson Comorbidity Index; CSA = cross-sectional area; EBL = estimated blood loss; JOA = Japanese Orthopaedic Association; LLIF = lateral lumbar interbody fusion; PLIF = posterior lumbar interbody fusion; PS = propensity score; SSI = surgical site infection; TLIF = transforaminal lumbar interbody fusion.

OBJECTIVE

The purpose of this study was to compare the clinical results of revision interbody fusion surgery between lateral lumbar interbody fusion (LLIF) and posterior lumbar interbody fusion (PLIF) or transforaminal lumbar interbody fusion (TLIF) with propensity score (PS) adjustments and to investigate the efficacy of indirect decompression with LLIF in previously decompressed segments on the basis of radiological assessment.

METHODS

A retrospective study of patients who underwent revision surgery for recurrence of neurological symptoms after posterior decompression surgery was performed. Postoperative complications and operative factors were evaluated and compared between LLIF and PLIF/TLIF. Moreover, postoperative improvement in cross-sectional areas (CSAs) in the spinal canal and intervertebral foramen was evaluated in LLIF cases.

RESULTS

A total of 56 patients (21 and 35 cases of LLIF and PLIF/TLIF, respectively) were included. In the univariate analysis, the LLIF group had significantly more endplate injuries (p = 0.03) and neurological deficits (p = 0.042), whereas the PLIF/TLIF group demonstrated significantly more dural tears (p < 0.001), surgical site infections (SSIs) (p = 0.02), and estimated blood loss (EBL) (p < 0.001). After PS adjustments, the LLIF group still showed significantly more endplate injuries (p = 0.03), and the PLIF/TLIF group demonstrated significantly more dural tears (p < 0.001), EBL (p < 0.001), and operating time (p = 0.04). The PLIF/TLIF group showed a trend toward a higher incidence of SSI (p = 0.10). There was no statistically significant difference regarding improvement in the Japanese Orthopaedic Association scores between the 2 surgical procedures (p = 0.77). The CSAs in the spinal canal and foramen were both significantly improved (p < 0.001).

CONCLUSIONS

LLIF is a safe, effective, and less invasive procedure with acceptable complication rates for revision surgery for previously decompressed segments. Therefore, LLIF can be an alternative to PLIF/TLIF for restenosis after posterior decompression surgery.

ABBREVIATIONS ASA-PS = American Society of Anesthesiologists Physical Status Classification System; CCI = Charlson Comorbidity Index; CSA = cross-sectional area; EBL = estimated blood loss; JOA = Japanese Orthopaedic Association; LLIF = lateral lumbar interbody fusion; PLIF = posterior lumbar interbody fusion; PS = propensity score; SSI = surgical site infection; TLIF = transforaminal lumbar interbody fusion.

Revision posterior fusion surgery in previously decompressed segments is technically challenging. Traditionally, posterior lumbar interbody fusion (PLIF) or transforaminal lumbar interbody fusion (TLIF) has been performed through a direct redecompression procedure for symptomatic restenosis. Since previous surgical explorations and tissue healing processes altered the anatomical landmarks in the spine, revision posterior surgeries have been associated with an increased risk of perioperative complications, such as dural tear, neural injury, and surgical site infection (SSI).1–4 Lateral lumbar interbody fusion (LLIF) is a relatively new minimally invasive surgical technique used as an alternative to PLIF/TLIF.5,6 One advantage of LLIF is its feasibility of achieving neural decompression indirectly by reducing disc bulging, elongating the ligamentum flavum by restoring disc height, and reducing spondylolisthesis with ligamentotaxis.7–9

Currently, only a few reports have shown the clinical evaluation of LLIF for revision surgery. Moreover, these studies were performed on heterogeneous patient populations, including LLIF for adjacent-segment disease after previous fusion surgery, LLIF with direct decompression, or LLIF for deformity correction.10–13 Therefore, few studies have exclusively investigated the clinical outcomes of revision LLIF for patients with the most common indication for revision fusion surgery: fusion for recurrent symptoms due to restenosis of the spinal canal or foramen after a decompression procedure.

In this study, we compared the results between revision LLIF and PLIF/TLIF for neural restenosis patients after posterior decompression. Moreover, one major challenge of revision surgery is scar tissue formation due to previous surgery. This scar tissue might prevent adequate indirect decompression of LLIF, as shown in studies evaluating the outcomes of the primary LLIF procedure. Therefore, this study had the following two objectives: 1) to compare the clinical results, including perioperative complications of revision interbody fusion surgery, between LLIF and PLIF/TLIF by utilizing the propensity score (PS) to adjust potential confounders that influence the decision to select between the LLIF and PLIF/TLIF surgical techniques; and 2) to investigate the efficacy of indirect decompression with LLIF in previously decompressed spinal segments based on radiological assessment.

Methods

Patients and Inclusion Criteria

Institutional review board approval was obtained; informed consent from each patient was waived because of the retrospective nature of this study. We reviewed the data of patients undergoing revision interbody fusion surgery between 2014 and 2018 at three institutions. We included patients who underwent primary posterior decompression surgery for neurological symptoms and/or neuropathic leg pain. Patients who had recurrent or new-onset neurological symptoms and/or leg pain underwent revision interbody fusion surgery. We excluded patients with previous instrumentation, fracture, or additional decompression surgery in adjacent segments during revision surgery, and those whose indication for revision surgery was included in a long-construct deformity correction surgery.

LLIF was performed using the extreme lateral interbody fusion system (NuVasive, Inc.) or the oblique lateral interbody fusion system (Medtronic) with percutaneous pedicle screw fixation without direct decompression. PLIF/TLIF was performed using direct decompression and cage insertion by resection of at least the unilateral facet joint. During the surgical procedure, the endplates were carefully prepared without using a rotating shaver. All operations were performed by board-certified spine surgeons with at least 5 years of experience after completing surgical training. The surgical approach was chosen at the discretion of the treating surgeon.

As potential confounders for operative indications for LLIF and PLIF/TLIF, data from the American Society of Anesthesiologists Physical Status Classification System (ASA-PS), the Charlson Comorbidity Index (CCI), indications for primary and revision surgeries, the number of fused levels, the operated level of revision surgery, the time between primary and revision surgeries, and the preoperative Japanese Orthopaedic Association (JOA) scores for lumbar disease14 were collected along with baseline data of patients and compared between the LLIF and PLIF/TLIF groups.

Outcome Measures

We investigated the differences in the following three outcomes between LLIF and PLIF/TLIF patients: 1) the incidence of postoperative complications, including incidental dural tear, and SSI; onset of neurological deficits, including motor and sensory symptoms; endplate injury; and reoperation within 12 months for any reason; 2) operative factors such as estimated blood loss (EBL) and operative time; and 3) postoperative improvement in JOA score for lumbar diseases.

The dural tear was defined as CSF leakage at the surgical site, including definitive dural tear as confirmed through intraoperative findings, and possible dural tear on postoperative imaging as a new-onset pseudomeningocele. SSI was defined as a microbiologically or clinically confirmed bacterial infection, including in the deep and superficial layers, which required additional interventions such as antibiotics or surgical debridement. The neurological injury was defined as new-onset or deterioration of preexisting motor or sensory symptoms, including transient and permanent ones. Endplate injury was defined as endplate violations with > 2 mm of cage subsidence as seen on CT scanning performed intraoperatively or immediately postoperatively.

As an additional analysis in LLIF revision patients, postoperative improvement in the cross-sectional areas (CSAs) of the spinal canal and foramen was evaluated in all LLIF cases according to 3-month follow-up imaging reports. Pre- and postoperative CSAs in the spinal canal and foramen were measured on axial T2-weighted images and sagittal CT reconstruction images, respectively, as described in a previous report.8,9 Based on the institutional protocol for revision fusion surgery, all patients underwent postoperative CT scanning within a few days after the surgery and at the 3-month follow-up visit. Additionally, all patients underwent a postoperative MRI at the 3-month follow-up. All radiographic assessments were performed by two board-certified orthopedic spine surgeons blinded to the patients’ clinical information, using a PACS (INFINITT PACS, INFINITT Healthcare Co., Ltd.).

Propensity Score Calculation and Statistical Analysis

Retrospective comparative studies on revision surgery are plagued by the possible selection bias for the choice between LLIF and PLIF/TLIF approaches. Although the indications overlapped, few factors could be considered by the treating surgeons for choosing between these 2 approaches, which should be adjusted appropriately to obtain generalizable results. In this study, we calculated the PS for the decision to choose between the LLIF and PLIF/TLIF surgical techniques and utilized the score for adjusting potential confounders. Comparisons between categorical variables were performed utilizing Fisher’s exact test. Comparisons between continuous variables were performed using the paired t-test or Mann-Whitney U-test. The PS of each patient, defined as the probability of being treated with LLIF or PLIF/TLIF, was calculated using a logistic regression model including all variables. The C-statistic value of the PS regression model was calculated to assess the appropriateness of variable selection. After calculating the PS, logistic regression and linear regression analyses were conducted by setting each outcome measure as a response variable, LLIF or PLIF/TLIF as the predictor variable, and the PS as the single confounding variable. Since the expected numbers of observed events in the logistic regression analyses were small and complete or near-complete separation would occur, we utilized Firth’s bias reduction method for maximum likelihood estimation. Statistical analysis was performed utilizing R software (R for 3.5.1, r-project.org). The statistical significance level was set at p < 0.05.

Results

A total of 56 patients were selected for the study; 21 patients underwent LLIF, and 35 patients underwent PLIF/TLIF. The mean follow-up durations for LLIF and PLIF/TLIF patients were 28.4 months (range 12–49 months) and 31.7 months (range 15–55 months), respectively. There were no statistically significant differences between the treatment groups regarding age, sex, time between surgeries, ASA-PS class, CCI, and preoperative JOA scores. However, there were significant differences in the operated spinal level, number of fused levels, and indications for revision surgery. The summary of demographics and preoperative factors is shown in Table 1. The results of the univariate analyses are summarized in Table 2. The LLIF group had significantly more endplate injury (p = 0.03) and onset of neurological deficits (p = 0.042), whereas the PLIF/TLIF group had significantly more dural tears (p < 0.001), SSIs (p = 0.02), and EBL (p < 0.001). Regarding endplate injury in the LLIF group (7 cases), L4–5 was the most involved level (4 cases, 57%), followed by L3–4, and cage subsidence was detected in 3 cases (43%). No patient required reoperation due to endplate injury, cage subsidence, or pseudarthrosis in either the LLIF or PLIF/TLIF group.

TABLE 1.

Patient demographics in the LLIF and PLIF/TLIF groups

Group
LLIFPLIF/TLIFp Value
No. of patients2135
Median age, yrs (IQR)69.00 (65.00–75.00)73.00 (68.00–77.50)0.317
Sex
 Male12 (57.1)21 (60.0)>0.999
 Female9 (42.9)14 (40.0)
Median follow-up, mos (IQR)28.00 (23.00–34.00)31.00 (21.50–38.50)0.334
Median time btwn 1st & 2nd ops, mos (IQR)43.00 (36.00–60.00)36.00 (30.00–51.00)0.210
Median preop JOA score (IQR)15.00 (13.00–16.00)16.00 (13.00–16.00)0.482
ASA-PS class (%)
 I3 (14.3)8 (22.9)0.722
 II10 (47.6)16 (45.7)
 III8 (38.1)11 (31.4)
CCI
 08 (38.1)12 (34.3)0.473
 12 (9.5)8 (22.9)
 ≥211 (52.4)15 (42.9)
No. of levels fused
 113 (61.9)30 (85.7)0.090
 27 (33.3)4 (11.4)
 31 (4.8)1 (2.9)
Revision level
 L1–20 (0.0)0 (0.0)>0.999
 L2–34 (19.0)1 (2.9)0.060
 L3–412 (57.1)12 (34.3)0.106
 L4–514 (66.7)23 (65.7)>0.999
 L5–sacrum0 (0.0)5 (14.3)0.145
Diagnosis at primary op
 Herniated disc4 (19.0)4 (11.4)0.456
 Degenerative spinal stenosis20 (95.2)32 (91.4)>0.999
 Spondylolisthesis5 (23.8)8 (22.9)>0.999
 Segmental instability14 (66.7)26 (74.3)0.557
Diagnosis at revision
 Central spinal canal stenosis3 (14.3)4 (11.4)>0.999
 Foraminal stenosis13 (61.9)10 (28.6)0.024
 Disc herniation/protrusion9 (42.9)8 (22.9)0.141

Boldface type indicates statistical significance.

TABLE 2.

The unadjusted comparisons of outcome measures between LLIF and PLIF/TLIF groups.

Group
LLIFPLIF/TLIFp Value
No. of patients2135
Complications, n (%)*
 Dural tear0 (0.0)16 (45.7)<0.001
  Definitive0 (0.0)11 (31.4)
  Possible0 (0.0)5 (14.3)
 SSI1 (4.8)11 (31.4)0.021
  Deep0 (0.0)4 (11.4)
  Superficial1 (4.8)7 (20.0)
 Neurological deficit6 (28.6)2 (5.7)0.042
  Permanent0 (0.0)2 (5.7)
  Transient6 (28.6)0 (0.0)
 Endplate injury7 (33.3)3 (8.6)0.030
 No. of patients w/ complications11 (52.4)22 (62.9)0.576
 Additional op1 (4.8)9 (25.7)0.072
Median EBL, ml (IQR)80.0 (80.0–100.0)250.0 (200.0–300.0)<0.001
Median op time, mins (IQR)180.0 (160.0–180.0)180.0 (165.0–210.0)0.111
Median improvement in JOA score (IQR)69.2 (61.5–75.0)62.5 (57.1–70.7)0.129

Boldface type indicates statistical significance.

Some patients had multiple complications.

Even after PS score adjustments, the LLIF group still had significantly more endplate injury (p = 0.03), and the PLIF/TLIF group demonstrated significantly more dural tears (p < 0.001), EBL (p < 0.001), and operating time (p = 0.04). There was no significant difference regarding SSI, but the PLIF/TLIF group showed a trend suggesting more infections (p = 0.10). The overall incidences of neurological deficits were not significantly different after PS adjustment. However, all neurological complications in the LLIF group were transient and recovered soon after surgery, while motor paralysis remained in 2 cases in the PLIF/TLIF group. Improvement in the JOA score in the LLIF group was acceptable (69.2%), and there was no significant difference between the 2 surgical procedures (p = 0.77). No patient required additional direct decompression in the LLIF group (Table 3).

TABLE 3.

Results of logistic and linear regression analyses with propensity score adjustment

Valuep Value
LLIF OR (95% CI)
 Complications
  Dural tear0.02 (0.00 to 0.27)<0.001
  SSI0.19 (0.01 to 1.36)0.102
  Neurological deficit2.18 (0.28 to 18.94)0.455
  Endplate injury7.47 (1.20 to 58.22)0.031
  All complications0.65 (0.15 to 2.73)0.553
  Additional op0.22 (0.02 to 1.73)0.160
LLIF regression coefficient (95% CI)
 EBL−215.6 (−283.9 to −147.2)<0.001
 Op time−22.2 (−43.4 to −0.96)0.041
 Improvement in JOA score1.25 (−7.4 to 9.8)0.770

Boldface type indicates statistical significance.

In the LLIF group, the mean preoperative spinal canal and foraminal CSAs were 106.4 ± 48.0 mm2 and 85.2 ± 24.8 mm2, respectively, which were significantly greater than the postoperative CSAs of the spinal canal and the mean of the bilateral foramina (143.2 ± 44.4 mm2 and 119.6 ± 24.7 mm2, respectively). Improvements in the CSAs in the spinal canal and foramen were 44.4% (p < 0.001) and 44.7% (p < 0.001), respectively (Table 4). Examples of CSA measurements in the LLIF group are shown in Fig. 1.

TABLE 4.

Preoperative and postoperative radiological measurements in the LLIF group

PreopPostopChangep Value
Spinal canal CSA106.4 (48.0) mm2143.2 (44.4) mm244.4 (30.6); range 4.3 to 150.0%<0.001
Foraminal CSA (bilat mean)85.2 (24.8) mm2119.6 (24.7) mm244.7 (24.1); range 6.8 to 98.0%<0.001
Slip2.3 (3.7) mm1.0 (1.7) mm−1.3 (2.4); range −5.8 to 6.0 mm0.006
Subsidence1.0 (1.0) mm

Values represent the mean (SD) unless stated otherwise. Boldface type indicates statistical significance.

FIG. 1.
FIG. 1.

Images obtained in a 78-year-old female patient with a 6-year history of L2–5 posterior decompression surgery showing reduction of L4–5 slippage and improvement of central spinal and foraminal stenoses in L3–4 and L4–5. A: Preoperative lateral radiograph showing L4–5 grade 2 slippage. B: Preoperative sagittal T2-weighted MR image showing a disc bulge and mild spinal canal stenosis at L3–4 as well as slippage and mild spinal canal stenosis at L4–5. C: Preoperative axial T2-weighted MR image at L3–4 indicating stenosis in the right lateral recess and bilateral foramina. D: Preoperative axial T2-weighted MR image at L4–5 showing bilateral foraminal stenosis. E: Postoperative lateral radiograph showing LLIF cages in the L3–4 and L4–5 disc spaces and pedicle screws from L3 to L5. The L4–5 slippage was successfully reduced. F: Postoperative sagittal T2-weighted MR image showing improvement of spinal canal stenosis. G: Postoperative axial T2-weighted MR image obtained at L3–4 showing improvement of spinal canal and bilateral foraminal stenoses. H: Postoperative axial T2-weighted MR image obtained at L4–5 showing improvement of spinal canal and bilateral foraminal stenoses.

Discussion

To the best of our knowledge, this is the first study to clinically and radiologically demonstrate the efficacy of indirect decompression of LLIF compared with PLIF/TLIF after revision spinal surgery by using PS adjustment. Application of the LLIF technique showed significantly fewer dural tears, EBL, and operative time, with comparable improvements in JOA scores.

In previous reports, the LLIF technique was applied to revision surgeries. However, the patient populations of those studies were heterogeneous and included patients with adjacent-segment disease,12,13 those requiring salvage for infection and pseudarthrosis,11 and those with recurrent disc herniation after percutaneous endoscopic lumbar discectomy.15 In this study, we applied strict inclusion criteria to elucidate the safety and efficacy of LLIF for revision interbody fusion, specifically at previously decompressed levels. This study is also unique in that we utilized PS to adjust the potential bias associated with the procedure selection. After adjustment with PS, the LLIF group showed favorable outcomes in terms of complications, EBL, and operative time. Moreover, our results indicated that indirect decompression of LLIF worked effectively even in the spinal levels with previous surgical exposure.

The incidence of dural tears during revision lumbar surgery was much higher (as high as 30%) than that of primary surgery in previous studies (4%–9%).3,4,16–18 Although most of these studies suggest that the incidence of dural tears does not affect surgical outcomes,17,19 a dural tear poses risks of reoperation and leads to longer hospitalization.20 In this study, the incidence of dural tears seemed to be higher (45.7%) than that seen in previous reports. The main reason for this discrepancy was that we included postoperative CSF leakage without an obvious intraoperative dural tear as a possible dural tear. When limited to definitive intraoperative dural tears, the incidence was comparable to those in previous reports (31.4%). Additionally, our patient populations were exclusively same-level postdecompression cases requiring redecompression, whereas previous studies potentially included patients without redecompression. We surmised that, in revision surgery, the real incidence of dural tears in revision PLIF/TLIF surgery with direct redecompression was much higher than previously reported. In contrast, there were no incidences of dural tear with LLIF because the previously decompressed segments were not directly exposed. This is the most significant benefit of indirect decompression utilizing LLIF in revision surgery compared with PLIF/TLIF. This trend was also observed after PS adjustments.

In this study, 6 patients (28.6%) in the LLIF group and 2 patients (5.7%) in the PLIF/TLIF group experienced a neurological deficit. Although the incidence of neurological deficit in the LLIF group was higher than that in the PLIF/TLIF group, all symptoms associated with LLIF recovered fully within 2 weeks, whereas 2 patients from the PLIF/TLIF group showed a permanent motor deficit. The incidence of symptomatic neurological complications after posterior revision surgeries varied, by 3.5%–32%, in previous reports.4,21 However, one report showed that one of 4 cases of neurological complications was permanent after PLIF.21 Regarding LLIF, approach-related neurological symptoms, such as quadriceps weakness and anterior thigh sensory disturbance, were reported as common issues (10%–30%).22 However, since the symptoms are transient, such patients have a better prognosis than those with the neurological complications due to PLIF/TLIF. Since potentially dangerous surgical scar tissue removal is not necessary for LLIF, the risk of direct dissection of the nerve root is expected to be very low, even during revision surgery of previously decompressed segments. We believe that this is one of the advantages of selecting LLIF for revision surgery.

In terms of SSI, there were 4 cases of deep infection and 7 cases of superficial infection in the PLIF/TLIF group and only 1 superficial infection in the LLIF group. Among infection cases in the PLIF/TLIF group, multiple reoperations were required in 3 patients, while only one minor additional surgery was needed in the LLIF group. Although a significant difference was not detected, a moderate trend (p = 0.10) of lower infection risk in the LLIF group was shown in the analyses with PS adjustment. Currently, no studies have specifically investigated the infection rates between PLIF and LLIF procedures for revision. Since the incidence of clinically important infection is low, further studies with larger sample sizes will be needed to reach an agreeable conclusion.

As a drawback of LLIF for revision, we noted the occurrence of endplate injury in 33% (7/21) of patients who underwent LLIF, whereas only 8.6% (3/35) of PLIF/TLIF patients had this complication. We speculated that surgeons might choose relatively taller cages to gain indirect decompression in patients undergoing LLIF. In this study, L4–5 was the most involved level (57%) for endplate injury. The possible reason is that the iliac crest often makes it difficult to approach L4–5 parallel to the endplates. In LLIF, endplate injuries may pose the risk of cage subsidence, resulting in loss of indirect decompression, which further worsens outcomes.23 Therefore, surgeons should be aware of preparing the endplate and choosing the size of the cage.

Previous studies have suggested some limitations regarding the effect of indirect decompression with LLIF in certain conditions.6,7,24 In these reports, osteophytes in the lateral recess, foraminal stenosis, and ossification of the posterior longitudinal ligament were risk factors for unplanned additional direct decompression. In this study, no LLIF patients required additional posterior decompression, although there were 3 cases of restenosis due to excessive bony formation in the LLIF group. This suggested that the abovementioned risk factors may not always be contraindications for revision LLIF. Hence, a robust conclusion was not possible with our data, and further studies are needed to refine the indication of LLIF for restenosis. As the current best practice, we recommend that surgeons should carefully evaluate the underlying conditions, such as instability or the location of the stenosis, and inform the patient of the possibility of additional direct decompression when they choose LLIF as the revision procedure.

Although we used PS to adjust multiple potential variables for treatment selection, this study has several limitations. First, this study was retrospective with a small sample size. Due to limited numbers of patients with certain complications, the event per variable in the logistic regression analyses was smaller than the recommended number of 10 events per variable. Although a report has stated that this rule could be relaxed for confounder adjustment,25 the overfitting of regression models can be detrimental, which should be addressed in future studies. Second, the data regarding osteoporosis, which might have a significant influence on endplate injury and cage subsidence, were not available because of the retrospective nature of this study. In this study, we compared LLIF for indirect decompression and PLIF/TLIF for direct decompression in revision fusion surgery. Although there is no doubt that investigating in more detail the differences between instrumentation systems and approaches (such as oblique lateral interbody fusion vs extreme lateral interbody fusion and PLIF vs TLIF in revision surgery) is clinically relevant, we could not include these factors due to data availability issues. Additionally, the operated level is an important issue in terms of the neurological deficit after LLIF. Since there were several cases with multiple-level fusion in this study, it was difficult to define the responsible level precisely. Further studies with larger sample sizes are warranted.

Conclusions

We demonstrated the efficacy of indirect decompression of LLIF compared with PLIF/TLIF in revision spinal surgery in clinical and radiological evaluation using logistic and regression analyses with PS adjustments. LLIF was associated with fewer dural tears, intraoperative blood loss, and operative time while resulting in more endplate injury compared with PLIF/TLIF. Our results suggest LLIF as a safe, effective, and less invasive procedure with acceptable complication rates for revision surgery for previously decompressed segments. LLIF can be an alternative to PLIF/TLIF for restenosis after posterior decompression surgery.

Disclosures

The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper.

Author Contributions

Conception and design: Kudo. Acquisition of data: Kudo, Matsuoka, Maruyama. Analysis and interpretation of data: Kudo, Okano. Drafting the article: Kudo. Critically revising the article: Kudo, Okano, Ishikawa, Hoshino. Reviewed submitted version of manuscript: Okano, Toyone, Matsuoka, Maruyama, Yamamura, Ishikawa, Hayakawa, Tani, Sekimizu, Hoshino, Ozawa, Shirahata, Fujita, Oshita, Emori, Omata, Inagaki. Approved the final version of the manuscript on behalf of all authors: Kudo. Statistical analysis: Kudo, Okano. Study supervision: Toyone, Inagaki.

Supplemental Information

Previous Presentations

An abstract of this research was presented at the 26th Annual Meeting of the Japan Society for the Study of Surgical Technique for Spine and Spinal Nerves, Chiba-city, Japan, October 2–3, 2019, and received the Best Presentation Award. In addition, it was accepted by the 2020 Global Spine Congress to have been held in Rio de Janeiro, Brazil, May 20–23, 2020, which was cancelled because of the 2019–2020 coronavirus outbreak (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

References

  • 1

    Tormenti MJ, Maserati MB, Bonfield CM, Perioperative surgical complications of transforaminal lumbar interbody fusion: a single-center experience. J Neurosurg Spine. 2012;16(1):4450.

    • Search Google Scholar
    • Export Citation
  • 2

    Selznick LA, Shamji MF, Isaacs RE. Minimally invasive interbody fusion for revision lumbar surgery: technical feasibility and safety. J Spinal Disord Tech. 2009;22(3):207213.

    • Search Google Scholar
    • Export Citation
  • 3

    Khan IS, Sonig A, Thakur JD, Perioperative complications in patients undergoing open transforaminal lumbar interbody fusion as a revision surgery. J Neurosurg Spine. 2013;18(3):260264.

    • Search Google Scholar
    • Export Citation
  • 4

    Kang MS, Park JY, Kim KH, Minimally invasive transforaminal lumbar interbody fusion with unilateral pedicle screw fixation: comparison between primary and revision surgery. Biomed Res Int. 2014;2014:919248.

    • Search Google Scholar
    • Export Citation
  • 5

    Ozgur BM, Aryan HE, Pimenta L, Taylor WR. Extreme Lateral Interbody Fusion (XLIF): a novel surgical technique for anterior lumbar interbody fusion. Spine J. 2006;6(4):435443.

    • Search Google Scholar
    • Export Citation
  • 6

    Malham GM, Parker RM, Goss B, Blecher CM. Clinical results and limitations of indirect decompression in spinal stenosis with laterally implanted interbody cages: results from a prospective cohort study. Eur Spine J. 2015;24(suppl 3):339345.

    • Search Google Scholar
    • Export Citation
  • 7

    Oliveira L, Marchi L, Coutinho E, Pimenta L. A radiographic assessment of the ability of the extreme lateral interbody fusion procedure to indirectly decompress the neural elements. Spine (Phila Pa 1976). 2010;35(26)(suppl):S331S337.

    • Search Google Scholar
    • Export Citation
  • 8

    Sato J, Ohtori S, Orita S, Radiographic evaluation of indirect decompression of mini-open anterior retroperitoneal lumbar interbody fusion: oblique lateral interbody fusion for degenerated lumbar spondylolisthesis. Eur Spine J. 2017;26(3):671678.

    • Search Google Scholar
    • Export Citation
  • 9

    Fujibayashi S, Hynes RA, Otsuki B, Effect of indirect neural decompression through oblique lateral interbody fusion for degenerative lumbar disease. Spine (Phila Pa 1976). 2015;40(3):E175E182.

    • Search Google Scholar
    • Export Citation
  • 10

    Formica M, Zanirato A, Cavagnaro L, Extreme lateral interbody fusion in spinal revision surgery: clinical results and complications. Eur Spine J. 2017;26(suppl 4):464470.

    • Search Google Scholar
    • Export Citation
  • 11

    Orita S, Nakajima T, Konno K, Salvage strategy for failed spinal fusion surgery using lumbar lateral interbody fusion technique: a technical note. Spine Surg Relat Res. 2018;2(1):8692.

    • Search Google Scholar
    • Export Citation
  • 12

    Louie PK, Varthi AG, Narain AS, Stand-alone lateral lumbar interbody fusion for the treatment of symptomatic adjacent segment degeneration following previous lumbar fusion. Spine J. 2018;18(11):20252032.

    • Search Google Scholar
    • Export Citation
  • 13

    Zhu G, Hao Y, Yu L, Comparing stand-alone oblique lumbar interbody fusion with posterior lumbar interbody fusion for revision of rostral adjacent segment disease: a STROBE-compliant study. Medicine (Baltimore). 2018;97(40):e12680.

    • Search Google Scholar
    • Export Citation
  • 14

    Fujiwara A, Kobayashi N, Saiki K, Association of the Japanese Orthopaedic Association score with the Oswestry Disability Index, Roland-Morris Disability Questionnaire, and Short-Form 36. Spine (Phila Pa 1976). 2003;28(14):16011607.

    • Search Google Scholar
    • Export Citation
  • 15

    Qiao G, Feng M, Wang X, Revision for endoscopic diskectomy: is lateral lumbar interbody fusion an option? World Neurosurg. 2020;133:e26e30.

    • Search Google Scholar
    • Export Citation
  • 16

    Lakkol S, Bhatia C, Taranu R, Efficacy of less invasive posterior lumbar interbody fusion as revision surgery for patients with recurrent symptoms after discectomy. J Bone Joint Surg Br. 2011;93(11):15181523.

    • Search Google Scholar
    • Export Citation
  • 17

    Wang J, Zhou Y, Zhang ZF, Minimally invasive or open transforaminal lumbar interbody fusion as revision surgery for patients previously treated by open discectomy and decompression of the lumbar spine. Eur Spine J. 2011;20(4):623628.

    • Search Google Scholar
    • Export Citation
  • 18

    Potter BK, Freedman BA, Verwiebe EG, Transforaminal lumbar interbody fusion: clinical and radiographic results and complications in 100 consecutive patients. J Spinal Disord Tech. 2005;18(4):337346.

    • Search Google Scholar
    • Export Citation
  • 19

    Bono CM, Brick GW. Revision surgery for lumbar stenosis: techniques, results, and complications. Semin Spine Surg. 2007;19(3):150164.

    • Search Google Scholar
    • Export Citation
  • 20

    Rajaee SS, Kanim LEA, Bae HW. National trends in revision spinal fusion in the USA: patient characteristics and complications. Bone Joint J. 2014;96-B(6)(B6):807816.

    • Search Google Scholar
    • Export Citation
  • 21

    Yamashita T, Okuda S, Aono H, Controllable risk factors for neurologic complications in posterior lumbar interbody fusion as revision surgery. World Neurosurg. 2018;116:e1181e1187.

    • Search Google Scholar
    • Export Citation
  • 22

    Winder MJ, Gambhir S. Comparison of ALIF vs. XLIF for L4/5 interbody fusion: pros, cons, and literature review. J Spine Surg. 2016;2(1):28.

    • Search Google Scholar
    • Export Citation
  • 23

    Tohmeh AG, Khorsand D, Watson B, Zielinski X. Radiographical and clinical evaluation of extreme lateral interbody fusion: effects of cage size and instrumentation type with a minimum of 1-year follow-up. Spine (Phila Pa 1976). 2014;39(26):E1582E1591.

    • Search Google Scholar
    • Export Citation
  • 24

    Nakashima H, Kanemura T, Satake K, Unplanned second-stage decompression for neurological deterioration caused by central canal stenosis after indirect lumbar decompression surgery. Asian Spine J. 2019;13(4):584591.

    • Search Google Scholar
    • Export Citation
  • 25

    Vittinghoff E, McCulloch CE. Relaxing the rule of ten events per variable in logistic and Cox regression. Am J Epidemiol. 2007;165(6):710718.

    • Search Google Scholar
    • Export Citation

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Contributor Notes

Correspondence Yoshifumi Kudo: Showa University, Tokyo, Japan. kudo_4423@med.showa-u.ac.jp.

INCLUDE WHEN CITING DOI: 10.3171/2020.6.FOCUS20361.

Disclosures The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper.

  • View in gallery

    Images obtained in a 78-year-old female patient with a 6-year history of L2–5 posterior decompression surgery showing reduction of L4–5 slippage and improvement of central spinal and foraminal stenoses in L3–4 and L4–5. A: Preoperative lateral radiograph showing L4–5 grade 2 slippage. B: Preoperative sagittal T2-weighted MR image showing a disc bulge and mild spinal canal stenosis at L3–4 as well as slippage and mild spinal canal stenosis at L4–5. C: Preoperative axial T2-weighted MR image at L3–4 indicating stenosis in the right lateral recess and bilateral foramina. D: Preoperative axial T2-weighted MR image at L4–5 showing bilateral foraminal stenosis. E: Postoperative lateral radiograph showing LLIF cages in the L3–4 and L4–5 disc spaces and pedicle screws from L3 to L5. The L4–5 slippage was successfully reduced. F: Postoperative sagittal T2-weighted MR image showing improvement of spinal canal stenosis. G: Postoperative axial T2-weighted MR image obtained at L3–4 showing improvement of spinal canal and bilateral foraminal stenoses. H: Postoperative axial T2-weighted MR image obtained at L4–5 showing improvement of spinal canal and bilateral foraminal stenoses.

  • 1

    Tormenti MJ, Maserati MB, Bonfield CM, Perioperative surgical complications of transforaminal lumbar interbody fusion: a single-center experience. J Neurosurg Spine. 2012;16(1):4450.

    • Search Google Scholar
    • Export Citation
  • 2

    Selznick LA, Shamji MF, Isaacs RE. Minimally invasive interbody fusion for revision lumbar surgery: technical feasibility and safety. J Spinal Disord Tech. 2009;22(3):207213.

    • Search Google Scholar
    • Export Citation
  • 3

    Khan IS, Sonig A, Thakur JD, Perioperative complications in patients undergoing open transforaminal lumbar interbody fusion as a revision surgery. J Neurosurg Spine. 2013;18(3):260264.

    • Search Google Scholar
    • Export Citation
  • 4

    Kang MS, Park JY, Kim KH, Minimally invasive transforaminal lumbar interbody fusion with unilateral pedicle screw fixation: comparison between primary and revision surgery. Biomed Res Int. 2014;2014:919248.

    • Search Google Scholar
    • Export Citation
  • 5

    Ozgur BM, Aryan HE, Pimenta L, Taylor WR. Extreme Lateral Interbody Fusion (XLIF): a novel surgical technique for anterior lumbar interbody fusion. Spine J. 2006;6(4):435443.

    • Search Google Scholar
    • Export Citation
  • 6

    Malham GM, Parker RM, Goss B, Blecher CM. Clinical results and limitations of indirect decompression in spinal stenosis with laterally implanted interbody cages: results from a prospective cohort study. Eur Spine J. 2015;24(suppl 3):339345.

    • Search Google Scholar
    • Export Citation
  • 7

    Oliveira L, Marchi L, Coutinho E, Pimenta L. A radiographic assessment of the ability of the extreme lateral interbody fusion procedure to indirectly decompress the neural elements. Spine (Phila Pa 1976). 2010;35(26)(suppl):S331S337.

    • Search Google Scholar
    • Export Citation
  • 8

    Sato J, Ohtori S, Orita S, Radiographic evaluation of indirect decompression of mini-open anterior retroperitoneal lumbar interbody fusion: oblique lateral interbody fusion for degenerated lumbar spondylolisthesis. Eur Spine J. 2017;26(3):671678.

    • Search Google Scholar
    • Export Citation
  • 9

    Fujibayashi S, Hynes RA, Otsuki B, Effect of indirect neural decompression through oblique lateral interbody fusion for degenerative lumbar disease. Spine (Phila Pa 1976). 2015;40(3):E175E182.

    • Search Google Scholar
    • Export Citation
  • 10

    Formica M, Zanirato A, Cavagnaro L, Extreme lateral interbody fusion in spinal revision surgery: clinical results and complications. Eur Spine J. 2017;26(suppl 4):464470.

    • Search Google Scholar
    • Export Citation
  • 11

    Orita S, Nakajima T, Konno K, Salvage strategy for failed spinal fusion surgery using lumbar lateral interbody fusion technique: a technical note. Spine Surg Relat Res. 2018;2(1):8692.

    • Search Google Scholar
    • Export Citation
  • 12

    Louie PK, Varthi AG, Narain AS, Stand-alone lateral lumbar interbody fusion for the treatment of symptomatic adjacent segment degeneration following previous lumbar fusion. Spine J. 2018;18(11):20252032.

    • Search Google Scholar
    • Export Citation
  • 13

    Zhu G, Hao Y, Yu L, Comparing stand-alone oblique lumbar interbody fusion with posterior lumbar interbody fusion for revision of rostral adjacent segment disease: a STROBE-compliant study. Medicine (Baltimore). 2018;97(40):e12680.

    • Search Google Scholar
    • Export Citation
  • 14

    Fujiwara A, Kobayashi N, Saiki K, Association of the Japanese Orthopaedic Association score with the Oswestry Disability Index, Roland-Morris Disability Questionnaire, and Short-Form 36. Spine (Phila Pa 1976). 2003;28(14):16011607.

    • Search Google Scholar
    • Export Citation
  • 15

    Qiao G, Feng M, Wang X, Revision for endoscopic diskectomy: is lateral lumbar interbody fusion an option? World Neurosurg. 2020;133:e26e30.

    • Search Google Scholar
    • Export Citation
  • 16

    Lakkol S, Bhatia C, Taranu R, Efficacy of less invasive posterior lumbar interbody fusion as revision surgery for patients with recurrent symptoms after discectomy. J Bone Joint Surg Br. 2011;93(11):15181523.

    • Search Google Scholar
    • Export Citation
  • 17

    Wang J, Zhou Y, Zhang ZF, Minimally invasive or open transforaminal lumbar interbody fusion as revision surgery for patients previously treated by open discectomy and decompression of the lumbar spine. Eur Spine J. 2011;20(4):623628.

    • Search Google Scholar
    • Export Citation
  • 18

    Potter BK, Freedman BA, Verwiebe EG, Transforaminal lumbar interbody fusion: clinical and radiographic results and complications in 100 consecutive patients. J Spinal Disord Tech. 2005;18(4):337346.

    • Search Google Scholar
    • Export Citation
  • 19

    Bono CM, Brick GW. Revision surgery for lumbar stenosis: techniques, results, and complications. Semin Spine Surg. 2007;19(3):150164.

    • Search Google Scholar
    • Export Citation
  • 20

    Rajaee SS, Kanim LEA, Bae HW. National trends in revision spinal fusion in the USA: patient characteristics and complications. Bone Joint J. 2014;96-B(6)(B6):807816.

    • Search Google Scholar
    • Export Citation
  • 21

    Yamashita T, Okuda S, Aono H, Controllable risk factors for neurologic complications in posterior lumbar interbody fusion as revision surgery. World Neurosurg. 2018;116:e1181e1187.

    • Search Google Scholar
    • Export Citation
  • 22

    Winder MJ, Gambhir S. Comparison of ALIF vs. XLIF for L4/5 interbody fusion: pros, cons, and literature review. J Spine Surg. 2016;2(1):28.

    • Search Google Scholar
    • Export Citation
  • 23

    Tohmeh AG, Khorsand D, Watson B, Zielinski X. Radiographical and clinical evaluation of extreme lateral interbody fusion: effects of cage size and instrumentation type with a minimum of 1-year follow-up. Spine (Phila Pa 1976). 2014;39(26):E1582E1591.

    • Search Google Scholar
    • Export Citation
  • 24

    Nakashima H, Kanemura T, Satake K, Unplanned second-stage decompression for neurological deterioration caused by central canal stenosis after indirect lumbar decompression surgery. Asian Spine J. 2019;13(4):584591.

    • Search Google Scholar
    • Export Citation
  • 25

    Vittinghoff E, McCulloch CE. Relaxing the rule of ten events per variable in logistic and Cox regression. Am J Epidemiol. 2007;165(6):710718.

    • Search Google Scholar
    • Export Citation

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