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"Outside-in" technique, clinical results, and indications with transforaminal lumbar endoscopic surgery: a retrospective study on 220 patients on applied radiographic classification of foraminal spinal stenosis.

Lewandrowski KU - Int J Spine Surg (2014)

Bottom Line: According to the Macnab criteria, excellent and good results were obtained in 85% (186/220) of patients with monoradiculopathy.The mean VAS score decreased from 7.5 ± 1.5 preoperatively to 2.8 ± 1.9 at the final follow-up (P < 0.01).Less favorable outcomes were observed in patients with concomitant contained disc herniations when compared to extruded disc herniations (P < 0.03) as well in patients older than 50 years of age (P < 0.021).

View Article: PubMed Central - PubMed

Affiliation: Center for Advanced Spinal Surgery of Southern Arizona, Tucson, AZ.

ABSTRACT

Objective: To analyze and describe appropriate surgical indications for endoscopically performed transforaminal decompression with the outside-in technique with foraminoplasty in patients with lateral stenosis with and without herniated disc.

Background and significance: Endoscopic microdiscectomy is growing in popularity for the removal of lumbar disc herniations. Recent advances in surgical techniques allow for percutaneous endoscopically assisted bony decompression as well.

Materials and methods: A retrospective study of 220 consecutive patients undergoing percutaneous endoscopic transforaminal foraminoplasty and microdiscectomy at 228 levels was conducted with intent of identifying appropriate surgical indications in patients with monoradiculopathy. The mean follow up was 46 months ranging from 26 to 54 months. Preoperatively, foraminal and lateral recess stenosis was graded on preoperative MRI and CT scans by dividing the lumbar neuroforamen into three zones: a) entry zone, b) middle zone, and c) exit zone. In addition, the presence of disc herniation causing neural element compression in the lateral recess and neuroforamen was noted. Disc herniations, if present, were recorded as either extruded and contained disc herniations. Surgical outcomes were classified according to the Macnab criteria. In addition, reductions in VAS scores were assessed.

Results: According to the Macnab criteria, excellent and good results were obtained in 85% (186/220) of patients with monoradiculopathy. The mean VAS score decreased from 7.5 ± 1.5 preoperatively to 2.8 ± 1.9 at the final follow-up (P < 0.01). Concomitant extruded disc herniations and contained disc bulges were recorded in 24 and 82 patients, respectively. There were no approach-related complications. Clinical failures occurred in patients with bony stenosis in the lateral recess and entry zone of the neuroforamen. Less favorable outcomes were observed in patients with concomitant contained disc herniations when compared to extruded disc herniations (P < 0.03) as well in patients older than 50 years of age (P < 0.021).

Conclusions: Percutaneous, endoscopic decompression using outside-in technique works well in patients with monoradiculopathy due to lateral stenosis in the mid and exit zone of the neuroforamen. Decompression in the entry zone maybe inadequate using the transforaminal outside-in approach. Future studies with greater statistical power should determine as to whether pain relief was achieved via microdiscectomy or foraminoplasty.

No MeSH data available.


Related in: MedlinePlus

Preoperative CT scans of a 70 year old male: a) panel on the left shows axial CT cuts from L3 to L5, b-d) panel shows sagittal CT cuts through the entry (shaded orange), middle (shaded turquoise), and exit zone (shaded green) of the lumbar neuroforamina, e) axial CT cut through the L3-4 disc space showing the stenotic lesion in the middle zone at that level, f-g) sagittal CT cuts through the middle zone at L3-4, and the L4-5 level. The neuroforaminal height (orange shade area) is less than 5 mm. The neuroforaminal width is less than 2 mm. Both indicators are consistent with spinal stenosis.
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Figure 0001: Preoperative CT scans of a 70 year old male: a) panel on the left shows axial CT cuts from L3 to L5, b-d) panel shows sagittal CT cuts through the entry (shaded orange), middle (shaded turquoise), and exit zone (shaded green) of the lumbar neuroforamina, e) axial CT cut through the L3-4 disc space showing the stenotic lesion in the middle zone at that level, f-g) sagittal CT cuts through the middle zone at L3-4, and the L4-5 level. The neuroforaminal height (orange shade area) is less than 5 mm. The neuroforaminal width is less than 2 mm. Both indicators are consistent with spinal stenosis.

Mentions: Lee's classification of foraminal and lateral recess stenosis was used to define the location of the offending pathology within the neuroforamen by dividing it from medial to lateral into entry (dura to pedicle; zone 1), middle (medial pedicle wall to center pedicle; zone 2), and exit zone (center pedicle to lateral border of the facet joint; zone 3).14 Foraminal and lateral recess stenosis were stratified according to the main offending pathology: extruded herniated disc, disc bulge, and bony stenosis. In the entry zone, Lee described hypertrophy of the superior articular face as the predominant pathology. In the mid-zone, it was often due to an osteophytic process underneath the pars interarticularis, and in the exit zone due a subluxed and hypertrophic facet joint (Figure 1).14


"Outside-in" technique, clinical results, and indications with transforaminal lumbar endoscopic surgery: a retrospective study on 220 patients on applied radiographic classification of foraminal spinal stenosis.

Lewandrowski KU - Int J Spine Surg (2014)

Preoperative CT scans of a 70 year old male: a) panel on the left shows axial CT cuts from L3 to L5, b-d) panel shows sagittal CT cuts through the entry (shaded orange), middle (shaded turquoise), and exit zone (shaded green) of the lumbar neuroforamina, e) axial CT cut through the L3-4 disc space showing the stenotic lesion in the middle zone at that level, f-g) sagittal CT cuts through the middle zone at L3-4, and the L4-5 level. The neuroforaminal height (orange shade area) is less than 5 mm. The neuroforaminal width is less than 2 mm. Both indicators are consistent with spinal stenosis.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4325483&req=5

Figure 0001: Preoperative CT scans of a 70 year old male: a) panel on the left shows axial CT cuts from L3 to L5, b-d) panel shows sagittal CT cuts through the entry (shaded orange), middle (shaded turquoise), and exit zone (shaded green) of the lumbar neuroforamina, e) axial CT cut through the L3-4 disc space showing the stenotic lesion in the middle zone at that level, f-g) sagittal CT cuts through the middle zone at L3-4, and the L4-5 level. The neuroforaminal height (orange shade area) is less than 5 mm. The neuroforaminal width is less than 2 mm. Both indicators are consistent with spinal stenosis.
Mentions: Lee's classification of foraminal and lateral recess stenosis was used to define the location of the offending pathology within the neuroforamen by dividing it from medial to lateral into entry (dura to pedicle; zone 1), middle (medial pedicle wall to center pedicle; zone 2), and exit zone (center pedicle to lateral border of the facet joint; zone 3).14 Foraminal and lateral recess stenosis were stratified according to the main offending pathology: extruded herniated disc, disc bulge, and bony stenosis. In the entry zone, Lee described hypertrophy of the superior articular face as the predominant pathology. In the mid-zone, it was often due to an osteophytic process underneath the pars interarticularis, and in the exit zone due a subluxed and hypertrophic facet joint (Figure 1).14

Bottom Line: According to the Macnab criteria, excellent and good results were obtained in 85% (186/220) of patients with monoradiculopathy.The mean VAS score decreased from 7.5 ± 1.5 preoperatively to 2.8 ± 1.9 at the final follow-up (P < 0.01).Less favorable outcomes were observed in patients with concomitant contained disc herniations when compared to extruded disc herniations (P < 0.03) as well in patients older than 50 years of age (P < 0.021).

View Article: PubMed Central - PubMed

Affiliation: Center for Advanced Spinal Surgery of Southern Arizona, Tucson, AZ.

ABSTRACT

Objective: To analyze and describe appropriate surgical indications for endoscopically performed transforaminal decompression with the outside-in technique with foraminoplasty in patients with lateral stenosis with and without herniated disc.

Background and significance: Endoscopic microdiscectomy is growing in popularity for the removal of lumbar disc herniations. Recent advances in surgical techniques allow for percutaneous endoscopically assisted bony decompression as well.

Materials and methods: A retrospective study of 220 consecutive patients undergoing percutaneous endoscopic transforaminal foraminoplasty and microdiscectomy at 228 levels was conducted with intent of identifying appropriate surgical indications in patients with monoradiculopathy. The mean follow up was 46 months ranging from 26 to 54 months. Preoperatively, foraminal and lateral recess stenosis was graded on preoperative MRI and CT scans by dividing the lumbar neuroforamen into three zones: a) entry zone, b) middle zone, and c) exit zone. In addition, the presence of disc herniation causing neural element compression in the lateral recess and neuroforamen was noted. Disc herniations, if present, were recorded as either extruded and contained disc herniations. Surgical outcomes were classified according to the Macnab criteria. In addition, reductions in VAS scores were assessed.

Results: According to the Macnab criteria, excellent and good results were obtained in 85% (186/220) of patients with monoradiculopathy. The mean VAS score decreased from 7.5 ± 1.5 preoperatively to 2.8 ± 1.9 at the final follow-up (P < 0.01). Concomitant extruded disc herniations and contained disc bulges were recorded in 24 and 82 patients, respectively. There were no approach-related complications. Clinical failures occurred in patients with bony stenosis in the lateral recess and entry zone of the neuroforamen. Less favorable outcomes were observed in patients with concomitant contained disc herniations when compared to extruded disc herniations (P < 0.03) as well in patients older than 50 years of age (P < 0.021).

Conclusions: Percutaneous, endoscopic decompression using outside-in technique works well in patients with monoradiculopathy due to lateral stenosis in the mid and exit zone of the neuroforamen. Decompression in the entry zone maybe inadequate using the transforaminal outside-in approach. Future studies with greater statistical power should determine as to whether pain relief was achieved via microdiscectomy or foraminoplasty.

No MeSH data available.


Related in: MedlinePlus