Long-term Clinical Outcomes After Bilateral Laminotomy or Total Laminectomy for Lumbar Spinal Stenosis

A Single-institution Experience

Andrea Pietrantonio, MD; Sokol Trungu, MD; Isabella Famà, MD; Stefano Forcato, MD; Massimo Miscusi, MD, PhD; Antonino Raco, MD, PhD


Neurosurg Focus. 2019;46(5):e2 

In This Article


Demographic Data

Between January 2000 and January 2003, 172 patients underwent lumbar laminectomies for DLSS: among these, 105 patients (61%) met the inclusion criteria and are the subject of this review (group 1). Similarly, between January 2005 and January 2008, 109 of the 168 patients (64.9%) who underwent bilateral laminotomies met the inclusion criteria and were included in this review (group 2). The mean age of the entire cohort was 69.5 years (range 58–77 years); there were 117 women (54.7%) and 97 men (45.3%) (M/F ratio 1.2:1)

The duration of symptoms ranged from 6 months to 3 years prior to surgical intervention. The most common clinical symptom was neurogenic claudication, reported by the entire group (214 patients, 100%), followed by low-back pain (70.6%), radiculopathy (58.9%), lower-limb weakness (55.6%), and sphincteric dysfunction (5.1%).

Of the 274 levels treated, the most commonly affected spinal level was L4–5 (142 patients, 51.8%) followed by L3–4 (58 patients, 21.2%), L5–S1 (15%), L2–3 (8.4%), and L1–2 (3.6%). A double-level decompression was performed in 32 patients in group 1 (30.5%) and in 30 patients (27.5%) in group 2.

In the laminectomy group, the average surgical time and intraoperative blood loss per level were 52 minutes and 95 ml, respectively; the average postoperative blood loss from suction drains was 110 ml. In the laminotomy group, the average surgical time per level was a little longer (68 minutes), whereas the intraoperative blood loss was consistently lower (50 ml). The average postoperative length of hospital stay (LOS) was shorter for the laminotomy group.

The comorbidity rate was high and mainly related to the mean age of our patients: 189 patients (88.3%) were affected by several medical diseases, including cardiovascular diseases (70.6%), respiratory diseases (55.6%), diabetes mellitus (54.2%), and obesity (38.8%). The American Society of Anesthesiologists (ASA) score was as follows: none had ASA I, 25 (11.7%) had ASA II, 143 (66.8%) had ASA III, and 46 (21.5%) had ASA IV.

All patients' medical records, including clinical and radiological data, are summarized in Table 1.

Clinical Outcomes

The mean preoperative VAS scores were 7.9 and 8.3 in the bilateral laminotomy and open laminectomy groups, respectively. At final follow-up, the improvement was greater in the laminotomy group (mean value 3.6) than in the laminectomy group (mean value 4.4), and a similar difference was noted at each follow-up visit.

Comparing pre- and postoperative values, both groups showed improvement in ODI and SF-36 scores. At final follow-up, a greater improvement was noted in the laminotomy group (mean ODI value 22.8, mean SF-36 value 70.2), considering the worse preoperative scores (mean ODI value 70, mean SF-36 value 38.4) with respect to the laminectomy group (mean ODI value 68.7, mean SF-36 value 36.3). However, there was no statistically significant difference in clinical outcomes (VAS, ODI, SF-36) between the 2 groups.

In both groups, none of the patients required postoperative rehabilitation. All patients' clinical outcomes are summarized in Table 2.

Reoperation Rate and Complications

In 9 cases (8.6%) in group 1 and in 5 cases (4.6%) in group 2, an incidental durotomy was reported. In the laminectomy group, the dural tear could be identified in all patients and directly repaired at surgery, whereas in 3 patients in the laminotomy group, the point of leakage could not be clearly seen and a dural sealant instead of direct suture had to be used. In these 14 patients, 3 days of postoperative bed rest was advised and no CSF fistula developed after surgery.

We observed 5 superficial wound infections (2.3% of the entire cohort), which resolved with antibiotic therapy and daily medications; 4 (3.8%) in group 1 and 1 (0.9%) in group 2.

During the follow-up period, 4 patients (3.7%) in group 2 underwent reoperation because of inadequate decompression; after a transient and partial relief of symptoms, a second operation had to be performed because of clinical deterioration and MRI evidence of lumbar stenosis at the treated level. All these patients underwent reoperation within 18 months of the first surgery.

In group 1, 16 patients (15.2%) underwent subsequent lumbar fusion surgery within 38 months: in 15 patients (93.7%), lumbar fusion was required to treat a postlaminectomy instability, whereas in the remaining patient a second decompression and fusion was performed to treat a residual stenosis (p = 0.0075).

All patients' reoperation rates and complications are summarized in Table 3.