#305 Complications of Minimally Invasive Spinal Surgery (MISS) for Correction of Adult Spinal Deformity – A 5 Year Experience

General Session: Lateral Interbody Fusion

Presented by: N. Anand


N. Anand (1)
B. Khandehroo (1)
S. Kahwaty (1)
E.M. Baron (1)

(1) Cedars Sinai Medical Center, Spine Center, Los Angeles, CA, USA


Introduction: MISS procedures are intended to reduce approach related morbidities and complications. However, the novelty of the approach and the potential for complications has been a big concern for surgeons in adopting these new techniques. In this study we assess if complications in patients undergoing MISS for spinal deformity is comparable to traditional open approaches.

Methods: A retrospective review of MISS cases for correction of thoracolumbar deformity revealed 177 patients. Patients with less than 3 levels fusion were excluded. This identified 102 patients for this study. Deformities included Idiopathic Scoliosis (29), Degenerative Scoliosis (64), Iatrogenic Scoliosis (8) and Kyphosis (1). All underwent a combination of 3 MIS techniques: Posterior instrumentation (100), DLIF (88) and AxiaLIF (51).

Results: Mean follow up was 31mths(3-65mths) with more than one year in 88 patients. Mean age was 63 yrs(21-85yrs). A total of 580 levels were operated with a mean of 5.7 levels per patient (3-13). 29 patients had a total of 32 complications. 19 early complications were noted in 19 patients. 5 were non-technique related in 5 patients: 2 with Illeus, 1 with DVT, 1 with pulmonary embolism and 1 with incidental cerebral hemorrhage. 14 were technique related in 14 patients: 2 pleural effusion who underwent thoracentesis, 4 neurological complications: 3 quadriceps palsy of which 2 made a complete recovery within 6mths and 1 foot drop post DLIF. 1 uretero-pelvic injury with DLIF who underwent nephrostomy and paracentesis, 1 with retrocapsular hematoma with no untoward effect. 2 patients with screw loosening and cut out that needed reinstrumentation, 4 patients with superficial sacral wound dehiscence that underwent debridement. 13 late complications noted in 12 patients. 4 patients had persistent radiculopathy: 1 with heterotopic ossification and 3 with stenosis and all underwent revision microdecompression at 1 year post-op. 5 patients developed a pseudoarthrosis, 2 as a result of late onset infection after 1 year and 18 months post-op and both were revised with removal of the implant, ALIF and iliac screw fixation. 1 patient had delayed union with a 3 level stand alone XLIF and revised with posterior instrumentation and fusion. The fourth patient had L5-S1 non-union with sacral pedicle screw loosening revised with iliac fixation and posterior fusion. All 4 confirmed fusion after revision surgery. 1 patient had asymptomatic pseudoarthrosis at 2 years post-op CT Scan and has had no intervention. 1 patient had PJK at 6 months post-op and underwent revision posterior instrumentation and fusion. 1 patient had a late wound infection at 6 months, 1 patient had adjacent segment osteomyelitis at 2 years post-op and underwent revision surgery, 1 patient had an adjacent segment disc herniation 2 years post-op. There was 1 patient with hardware prominence at 10 months post-op, which revised with screw removal and posterior fusion. Overall complication rate was 31% (n=32), with technique related 26.4% (n=27) and non technique-related 4.9% (n=5).

Conclusion: This study documents a short-term and long-term complication rate of 26.4% with MISS for Spinal Deformity. Most complications were not life threatening and were easily treated with proper intervention. This is considerably less than 40 to 86% complication rate quoted regarding surgery for adult spinal deformity.