Browsing by Author "Kanter, Adam"

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    ItemOpen Access
    Does MIS Surgery Allow for Shorter Constructs in the Surgical Treatment of Adult Spinal Deformity?
    (Neurosurgery, 2017-03) Uribe, Juan S; Beckman, Joshua; Mummaneni, Praveen V; Okonkwo, David; Nunley, Pierce; Wang, Michael Y; Mundis, Gregory M; Park, Paul; Eastlack, Robert; Anand, Neel; Kanter, Adam; Lamarca, Frank; Fessler, Richard; Shaffrey, Chris I; Lafage, Virginie; Chou, Dean; Deviren, Vedat; MIS-ISSG Group

    Background

    The length of construct can potentially influence perioperative risks in adult spinal deformity (ASD) surgery. A head-to-head comparison between open and minimally invasive surgery (MIS) techniques for treatment of ASD has yet to be performed.

    Objective

    To examine the impact of MIS approaches on construct length and clinical outcomes in comparison to traditional open approaches when treating similar ASD profiles.

    Methods

    Two multicenter databases for ASD, 1 involving MIS procedures and the other open procedures, were propensity matched for clinical and radiographic parameters in this observational study. Inclusion criteria were ASD and minimum 2-year follow-up. Independent t -test and chi-square test were used to evaluate and compare outcomes.

    Results

    A total of 1215 patients were identified, with 84 patients matched in each group. Statistical significance was found for mean levels fused (4.8 for circumferential MIS [cMIS] and 10.1 for open), mean interbody fusion levels (3.6 cMIS and 2.4 open), blood loss (estimated blood loss 488 mL cMIS and 1762 mL open), and hospital length of stay (6.7 days cMIS and 9.7 days open). There was no significant difference in preoperative radiographic parameters or postoperative clinical outcomes (Owestry Disability Index and visual analog scale) between groups. There was a significant difference in postoperative lumbar lordosis (43.3° cMIS and 49.8° open) and pelvic incidence-lumbar lordosis correction (10.6° cMIS and 5.2° open) in the open group. There was no significant difference in reoperation rate between the 2 groups.

    Conclusion

    MIS techniques for ASD may reduce construct length, reoperation rates, blood loss, and length of stay without affecting clinical and radiographic outcomes when compared to a similar group of patients treated with open techniques.
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    Intermediate-term clinical and radiographic outcomes with less invasive adult spinal deformity surgery: patients with a minimum follow-up of 4 years.
    (Acta Neurochir (Wien), 2020-04-14) Wang, Michael Y; Park, Paul; Tran, Stacie; Anand, Neel; Nunley, Pierce; Kanter, Adam; Fessler, Richard; Uribe, Juan; Eastlack, Robert; Shaffrey, Christopher I; Bess, Shay; Mundis, Gregory M; Brusko, G Damian; Mummaneni, Praveen V; MIS-ISSG Group
    BACKGROUND: Little information exists regarding longer-term outcomes with minimally invasive spine surgery (MISS), particularly regarding long-segment and deformity procedures. We aimed to evaluate intermediate-term outcomes of MISS for adult spinal deformity (ASD). METHODS: This retrospective review of a prospectively collected multicenter database examined outcomes at 4 or more years following circumferential MIS (cMIS) or hybrid (HYB) surgery for ASD. A total of 53 patients at 8 academic centers satisfied the following inclusion criteria: age > 18 years and coronal Cobb > 20°, pelvic incidence-lumbar lordosis (PI-LL) > 10°, or sagittal vertical axis (SVA) > 5 cm. RESULTS: Radiographic outcomes demonstrated improvements of PI-LL from 16.8° preoperatively to 10.8° and coronal Cobb angle from 38° preoperatively to 18.2° at 4 years. The incidence of complications over the follow-up period was 56.6%. A total of 21 (39.6%) patients underwent reoperation in the thoracolumbar spine, most commonly for adjacent level disease or proximal junctional kyphosis, which occurred in 11 (20.8%) patients. Mean Oswestry Disability Index (ODI) at baseline and years 1 through 4 were 49.9, 33.1, 30.2, 32.7, and 35.0, respectively. The percentage of patients meeting minimal clinically important difference (MCID) (defined as 12% or more from baseline) decreased over time, with leg pain reduction more durable than back pain reduction. CONCLUSIONS: Intermediate-term clinical and radiographic improvement following MISS for ASD is sustained, but extent of improvement lessens over time. Outcome variability exists within a subset of patients not meeting MCID, which increases over time after year two. Loss of improvement over time was more notable in back than leg pain. However, average ODI improvement meets MCID at 4 years after MIS ASD surgery.
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    ItemOpen Access
    Is There a Patient Profile That Characterizes a Patient With Adult Spinal Deformity as a Candidate for Minimally Invasive Surgery?
    (Global spine journal, 2017-10) Eastlack, Robert K; Mundis, Gregory M; Wang, Michael; Mummaneni, Praveen V; Uribe, Juan; Okonkwo, David; Akbarnia, Behrooz A; Anand, Neel; Kanter, Adam; Park, Paul; Lafage, Virginie; Shaffrey, Christopher; Fessler, Richard; Deviren, Vedat; International Spine Study Group
    Retrospective review.The goal of this study was to evaluate the baseline characteristics of patients chosen to undergo traditional open versus minimally invasive surgery (MIS) for adult spinal deformity (ASD).A multicenter review of 2 databases including ASD patients treated with surgery. Inclusion criteria were age >45 years, Cobb angle minimum of 20°, and minimum 2-year follow-up. Preoperative radiographic parameters and disability outcome measures were reviewed.A total of 350 patients were identified: 173 OPEN patients and 177 MIS. OPEN patients were significantly younger than MIS patients (61.5 years vs 63.74 years, P = .013). The OPEN group had significantly more females (87% vs 76%, P = .006), but both groups had similar body mass index. Preoperative lumbar Cobb was significantly higher for the OPEN group (34.2°) than for the MIS group (26.0°, P < .001). The mean preoperative Oswestry Disability Index was significantly higher in the MIS group (44.8 in OPEN patients and 49.8 in MIS patients, P < .011). The preoperative Numerical Rating Scale value for back pain was 7.2 in the OPEN group and 6.8 in the MIS group preoperatively, P = .100.Patients chosen for MIS for ASD are slightly older and have smaller coronal deformities than those chosen for open techniques, but they did not have a substantially lesser degree of sagittal malalignment. MIS surgery was most frequently utilized for patients with an sagittal vertical axis under 6 cm and a baseline pelvic incidence and lumbar lordosis mismatch under 30°.
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    ItemOpen Access
    Management of high-grade spondylolisthesis.
    (Neurosurgery clinics of North America, 2013-04) Kasliwal, Manish K; Smith, Justin S; Kanter, Adam; Chen, Ching-Jen; Mummaneni, Praveen V; Hart, Robert A; Shaffrey, Christopher I
    Management of high-grade spondylolisthesis (HGS) remains challenging and is associated with significant controversies. The best surgical procedure remains debatable. Although the need for instrumentation is generally agreed upon, significant controversies still surround the role of reduction and anterior column support in the surgical management of HGS. Complications with operative management of HGS can be significant and often dictate the selection of surgical approach. This review highlights the pathophysiology, classification, clinical presentation, and management controversies of HGS, in light of recent advances in our understanding of the importance of sagittal spinopelvic alignment and technologic advancements.
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    Minimally Invasive Spinal Deformity Surgery: Analysis of Patients Who Fail to Reach Minimal Clinically Important Difference.
    (World neurosurgery, 2020-02-12) Wang, Michael Y; Uribe, Juan; Mummaneni, Praveen V; Tran, Stacie; Brusko, G Damian; Park, Paul; Nunley, Pierce; Kanter, Adam; Okonkwo, David; Anand, Neel; Chou, Dean; Shaffrey, Christopher I; Fu, Kai-Ming; Mundis, Gregory M; Eastlack, Robert; Minimally Invasive Surgery-International Spine Study Group
    BACKGROUND:It is well known that clinical improvements following surgical intervention are variable. While all surgeons strive to maximize reliability and degree of improvement, certain patients will fail to achieve meaningful gains. We aim to analyze patients who failed to reach minimal clinically important difference (MCID) in an effort to improve outcomes for minimally invasive deformity surgery. METHODS:Data were collected on a multicenter registry of minimally invasive surgery adult spinal deformity surgeries. Patient inclusion criteria were age ≥18 years, coronal Cobb ≥20 degrees, pelvic incidence-lumbar lordosis ≥10 degrees, or a sagittal vertical axis >5 cm. All patients had minimum 2 years' follow-up (N = 222). MCID was defined as 12.8 or more points of improvement in the Oswestry Disability Index. Up to 2 different etiologies for failure were allowed per patient. RESULTS:We identified 78 cases (35%) where the patient failed to achieve MCID at long-term follow-up. A total of 82 identifiable causes were seen in these patients with 14 patients having multiple causes. In 6 patients, the etiology was unclear. The causes were subclassified as neurologic, medical, structural, under treatment, degenerative progression, traumatic, idiopathic, and floor effects. In 71% of cases, an identifiable cause was related to the spine, whereas in 35% the cause was not related to the spine. CONCLUSIONS:Definable causes of failed MIS ASD surgery are often identifiable and similar to open surgery. In some cases the cause is treatable and structural. However, it is also common to see failure due to pathologies unrelated to the index surgery.
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    Minimally Invasive Surgery for Mild-to-Moderate Adult Spinal Deformities: Impact on Intensive Care Unit and Hospital Stay.
    (World neurosurgery, 2019-07) Chou, Dean; Mundis, Gregory; Wang, Michael; Fu, Kai-Ming; Shaffrey, Christopher; Okonkwo, David; Kanter, Adam; Eastlack, Robert; Nguyen, Stacie; Deviren, Vedat; Uribe, Juan; Fessler, Richard; Nunley, Pierce; Anand, Neel; Park, Paul; Mummaneni, Praveen; International Spine Study Group

    Objective

    To compare circumferential minimally invasive (cMIS) versus open surgeries for mild-to-moderate adult spinal deformity (ASD) with regard to intensive care unit (ICU) and hospital lengths of stay (LOS).

    Methods

    A retrospective review of 2 multicenter ASD databases with 426 ASD (sagittal vertical axis <6 cm) surgery patients with 4 or more fusion levels and 2-year follow-up was conducted. ICU stay, LOS, and estimated blood loss (EBL) were compared between open and cMIS surgeries.

    Results

    Propensity matching resulted in 88 patients (44 cMIS, 44 open). cMIS were older (61 vs. 53 years, P = 0.005). Mean levels fused were 6.5 in cMIS and 7.1 in open (P = 0.368). Preoperative lordosis was higher in open than in cMIS (42.7° vs. 40.9°, P = 0.016), and preoperative visual analog score back pain was greater in open than in cMIS (7 vs. 6.2, P = 0.033). Preoperative and postoperative spinopelvic parameters and coronal Cobb angles were not different. EBL was 534 cc in cMIS and 1211 cc in open (P < 0.001). Transfusions were less in cMIS (27.3% vs. 70.5%, P < 0.001). ICU stay was 0.6 days for cMIS and 1.2 days for open (P = 0.009). Hospital LOS was 7.9 days for cMIS versus 9.6 for open (P = 0.804).

    Conclusions

    For patients with mild-to-moderate ASD, cMIS surgery had a significantly lower EBL and shorter ICU stay. Major and minor complication rates were lower in cMIS patients than open patients. Overall LOS was shorter in cMIS patients, but did not reach statistical significance.