Combined Interlaminar and Paraisthmic Approach for Co-existing Intracanal and Foraminal Lesion

Abstract

Objective: Stenosis or herniated nucleus pulposus (HNP) occupying lumbar intracanal and foraminal area is an important cause of double radicular symptoms. Using the combined interlaminar and paraisthmic approach, we performed decompression surgery in patients with co-existing intracanal and foraminal lesions. The objective of this study is to describe usefulness and outcome of combined interlaminar and paraisthmic approach surgery and to analysis the cause of poor outcome.

Methods: Between Apr 2009 and Apr 2014, 78 patients (42 males and 36 females) with intracanal and foraminal lesions were enrolled in this study. Patients with a vacuum disc, spondylolisthesis, instability or an isthmic defect on the preoperative dynamic view radiograph were excluded from this study. All patients underwent surgery through a combined approach for discectomy and decompression. The outcome of surgery was evaluated and classified into excellent, good, fair and poor.

Results: The results were excellent in 53 patients, good in 9, fair in 6 and poor in 10 during the follow-up. The outcome of the combined approach was excellent to fair in 87% (68 of 78) patients in our study. In the poor outcome group, three patients complained of early-onset relapsed pain (<1 month) and another seven patients complained of delayed-onset pain (>3 months).

Conclusion: Combined approach for both intracanal and foraminal area lesions may be useful if selectively performed on patients whose facet joint is relatively intact, and that it is worthy of consideration as an alternative to fusion surgery; however, further studies are needed.

Keywords: Lumbar; Radiculopathy; Spinal stenosis.

Fig. 1. Preoperative magnetic resonance (MR) images obtained at level L5-S1. (A) Axial T2-weighted MR image shows a herniated disc effacing both the central and the left foraminal zones. (B) Parasagittal T1-weighted image showing a left L5-S1 foraminal stenosis with perineural fat obliteration surrounding the nerve root compared with adjacent levels.

Fig. 2. Anatomical diagram showing the bony resection area (circle) of the combined interlaminar and paraisthmic approach for decompression surgery.