Transforaminal endoscopic decompression for radiculopathy secondary to intracanal noncontained lumbar disc herniations: outcome and technique

Abstract

Background context: In 1973 Kambin and Gellman introduced the concept of percutaneous posterolateral extracanal approach in the management of radiculopathy secondary to lumbar disc herniation (LDH). This new surgical approach was recognized as potentially even less invasive compared with the microscope-assisted transcanal technique. However, the development of the posterolateral extracanal approach has witnessed a slow and complicated technique and equipment evolution. Purpose: To report the surgical outcome, complications and technique of decompressing radiculopathy secondary to noncontained intracanal LDH using percutaneous extracanal access, the transforaminal endoscopic approach. Study design/setting: Consecutive cases of LDHs from L3–S1 who had at least 1-year postoperative follow-up were included in this retrospective review. Patient sample: Two hundred nineteen patients met inclusion criteria. There were 136 (62.1%) male patients, average age 41.5 years, and 83 (37.9%) female patients, average age 42.5 years. The age range was 17 to 71 years. Methods: Two outcome measures were used. The first part was a surgeon-performed assessment. The second used a patient-based outcome questionnaire. Outcome measures: The surgeon's retrospective assessment of excellent, good, fair and poor is a modified MacNab classification. The same terminology is used in the patient-based outcome questionnaire. Poor outcome resulting from technique failure is identified. Results: Two hundred nineteen patients met the inclusion criteria. One hundred ninety-three patients also send back their completed questionnaire. The surgeon graded 88% percent of the 219 patients had a good or excellent result and the questionnaire subgroup 91.2%. The fair results were 5% of the 219 patients, 3.6% for the questionnaire patients. The poor results were 6.8% of the 219 patients and 5.2% for the questionnaire subgroup. The overall complication rate was 2.7% and missed fragment rate 0.9%. Conclusions: Noncontained intracanal LDH fragments are accessible using the transforaminal endoscopic technique and equipment described. Retrospective outcome reviews of our clinical material showed results comparable to the reported findings in the literature for both the endoscopic and open transcanal decompression techniques.