Surgical data and early postoperative outcomes after minimally invasive lumbar interbody fusion: results of a prospective, multicenter, observational data-monitored study

Abstract

Minimally invasive lumbar interbody fusion (MILIF) offers potential for reduced operative morbidity and earlier recovery compared with open procedures for patients with degenerative lumbar disorders (DLD). Firm conclusions about advantages of MILIF over open procedures cannot be made because of limited number of large studies of MILIF in a real-world setting. Clinical effectiveness of MILIF in a large, unselected real-world patient population was assessed in this Prospective, monitored, international, multicenter, observational study.

Objective: To observe and document short-term recovery after minimally invasive interbody fusion for DLD.

Materials and methods: In a predefined 4-week analysis from this study, experienced surgeons (≥ 30 MILIF surgeries pre-study) treated patients with DLD by one- or two-level MILIF. The primary study objective was to document patients' short-term post-interventional recovery (primary objective) including back/leg pain (visual analog scale [VAS]), disability (Oswestry Disability Index [ODI]), health status (EQ-5D) and Patient satisfaction.

Results: At 4 weeks, 249 of 252 patients were remaining in the study; the majority received one-level MILIF (83%) and TLIF was the preferred approach (94.8%). For one-level (and two-level) procedures, surgery duration was 128 (182) min, fluoroscopy time 115 (154) sec, and blood-loss 164 (233) mL. Time to first ambulation was 1.3 days and time to study-defined surgery recovery was 3.2 days. Patients reported significantly (P < 0.0001) reduced back pain (VAS: 2.9 vs 6.2), leg pain (VAS: 2.5 vs 5.9), and disability (ODI: 34.5% vs 45.5%), and a significantly (P < 0.0001) improved health status (EQ-5D index: 0.61 vs 0.34; EQ VAS: 65.4 vs 52.9) 4 weeks postoperatively. One adverse event was classified as related to the minimally invasive surgical approach. No deep site infections or deaths were reported.

Conclusions: For experienced surgeons, MILIF for DLD demonstrated early benefits (short time to first ambulation, early recovery, high patient satisfaction and improved patient-reported outcomes) and low major perioperative morbidity at 4 weeks postoperatively.

Fig 1. Flow diagram of patient follow up.

Fig 2. Back pain intensity (a) and leg pain intensity scores (b) reported preoperatively and postoperatively on a 10-cm visual analog scale (VAS), where 0 = minimal pain intensity or pain frequency and 10 = maximal pain intensity or pain frequency (total population; N = 252).

P < 0.0001 for difference between preoperative (B: 6.2 ± 2.3; L: 5.9 ± 2.8), and 4-week postoperative scores (B: 2.9 ± 2.2; L: 2.5 ± 2.6).

Fig 3. Oswestry Disability Index (ODI) scores reported preoperatively and 4-week postoperatively on a 0% to 100% scale, where 0% = minimal disability and 100% = maximal disability (total population; N = 252).

P < 0.0001 for difference between preoperative (45.5 ± 15.4) and 4-week postoperative scores (34.5 ± 17.3).

Fig 4. EQ VAS scores reported preoperatively and 4-week postoperatively on a 0 to 100 scale, where 0 = maximal health-related problems and 100 = minimal health-related problems (total population; N = 252).

P < 0.0001 for difference between preoperative (52.9 ± 19.5) and 4-week postoperative scores (65.4 ± 18.6).

Fig 5. Five individual EQ-5D domains were reported preoperatively and 4-week postoperatively.

At 4 weeks, the percentages of patients who reported no health-related problems increased from preoperative values in each domain: mobility (40.3% vs 11.1%), self-care (63.3% vs 54.3%), usual activities (23.4% vs 9.6%), pain/discomfort (14.9% vs 1.4%), and anxiety/depression (63.5% vs 49.5%).