Browsing by Subject "Patient Positioning"

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    ItemOpen Access
    A Comparison of Three Different Positioning Techniques on Surgical Corrections and Postoperative Alignment in Cervical Spinal Deformity (CD) Surgery.
    (Spine, 2021-05) Morse, Kyle W; Lafage, Renaud; Passias, Peter; Ames, Christopher P; Hart, Robert; Shaffrey, Christopher I; Mundis, Gregory; Protopsaltis, Themistocles; Gupta, Munish; Klineberg, Eric; Burton, Doug; Lafage, Virginie; Kim, Han Jo; International Spine Study Group

    Study design

    Retrospective review of a prospective multicenter cervical deformity database.

    Objective

    To examine the differences in sagittal alignment correction between three positioning methods in cervical spinal deformity surgery (CD).

    Summary of background data

    Surgical correction for CD is technically demanding and various techniques are utilized to achieve sagittal alignment objectives. The effect of different patient positioning techniques on sagittal alignment correction following CD remains unknown.

    Methods

    Patients with sagittal deformity who underwent a posterior approach (with and without anterior approach) with an upper instrumented vertebra of C6 or above. Patients with Grade 5, 6, or 7 osteotomies were excluded. Positioning groups were Mayfield skull clamp, bivector traction, and halo ring. Preoperative lower surgical sagittal curve (C2-C7), C2-C7 sagittal vertical axis (cSVA), cervical scoliosis, T1 slope minus cervical lordosis (TS-CL), T1 slope (T1S), chin-brow vertebral angle (CBVA), C2-T3 curve, and C2-T3 SVA was assessed and compared with postoperative radiographs. Segmental changes were analyzed using the Fergusson method.

    Results

    Eighty patients (58% female) with a mean age of 60.6 ± 10.5 years (range, 31-83) were included. The mean postoperative C2-C7 lordosis was 7.8° ± 14 and C2-C7 SVA was 34.1 mm ± 15. There were overall significant changes in cervical alignment across the entire cohort, with improvements in T1 slope (P < 0.001), C2-C7 (P < 0.001), TS-CL (P < 0.001), and cSVA (P = 0.006). There were no differences postoperatively of any radiographic parameter between positioning groups (P > 0.05). The majority of segmental lordotic correction was achieved at C4-5-6 (mean 6.9° ± 11). Additionally, patients who had bivector traction applied had had significantly more segmental correction at C7-T1-T2 compared with Mayfield and halo traction (4.2° vs. 0.3° vs. -1.7° respectively, P < 0.027).

    Conclusion

    Postoperative cervical sagittal correction or alignment was not affected by patient position. The majority of segmental correction occurred at C4-5-6 across all positioning methods, while bivector traction had the largest corrective ability at the cervicothoracic junction.Level of Evidence: 4.
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    ItemOpen Access
    A positioning QA procedure for 2D/2D (kV/MV) and 3D/3D (CT/CBCT) image matching for radiotherapy patient setup.
    (Journal of applied clinical medical physics, 2009-10-06) Guan, Huaiqun; Hammoud, Rabih; Yin, Fang-Fang
    A positioning QA procedure for Varian's 2D/2D (kV/MV) and 3D/3D (planCT/CBCT) matching was developed. The procedure was to check: (1) the coincidence of on-board imager (OBI), portal imager (PI), and cone beam CT (CBCT)'s isocenters (digital graticules) to a linac's isocenter (to a pre-specified accuracy); (2) that the positioning difference detected by 2D/2D (kV/MV) and 3D/3D(planCT/CBCT) matching can be reliably transferred to couch motion. A cube phantom with a 2 mm metal ball (bb) at the center was used. The bb was used to define the isocenter. Two additional bbs were placed on two phantom surfaces in order to define a spatial location of 1.5 cm anterior, 1.5 cm inferior, and 1.5 cm right from the isocenter. An axial scan of the phantom was acquired from a multislice CT simulator. The phantom was set at the linac's isocenter (lasers); either AP MV/R Lat kV images or CBCT images were taken for 2D/2D or 3D/3D matching, respectively. For 2D/2D, the accuracy of each device's isocenter was obtained by checking the distance between the central bb and the digital graticule. Then the central bb in orthogonal DRRs was manually moved to overlay to the off-axis bbs in kV/MV images. For 3D/3D, CBCT was first matched to planCT to check the isocenter difference between the two CTs. Manual shifts were then made by moving CBCT such that the point defined by the two off-axis bbs overlay to the central bb in planCT. (PlanCT can not be moved in the current version of OBI1.4.) The manual shifts were then applied to remotely move the couch. The room laser was used to check the accuracy of the couch movement. For Trilogy (or Ix-21) linacs, the coincidence of imager and linac's isocenter was better than 1 mm (or 1.5 mm). The couch shift accuracy was better than 2 mm.
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    ItemOpen Access
    Effect of Prone Positional Apparatus on the Occurrence of Acute Kidney Injury After Spine Surgery.
    (World neurosurgery, 2019-08) Jin, Seok-Joon; Park, Yong-Seok; Kim, Sung-Hoon; Kim, Dongseop; Shim, Woo-Hyun; Jang, Dong-Min; Shaffrey, Christopher I; Naik, Bhiken I

    Background and objective

    Increased intra-abdominal pressure with prone positioning for spinal surgery is associated with intraoperative hemodynamic alterations and the potential for postoperative complications. This study investigated the incidence of postoperative acute kidney injury (AKI) in patients undergoing spine surgery on a Jackson spinal table or a Wilson frame.

    Methods

    A total of 1374 patients who underwent spine surgery were divided into 2 groups: Jackson spinal table (n = 598) and Wilson frame group (n = 776). After 1:1 propensity score matching, a final analysis was performed on 970 patients. The primary endpoint was a comparison of the incidence of AKI in the 2 groups.

    Results

    After propensity score matching analysis, the mean ± standard deviations of spine surgery invasiveness index were 4.7 ± 3.5 and 2.1 ± 1.4 in patients with the Jackson spinal table and the Wilson frame, respectively (P < 0.001). Considering the differences in surgical invasiveness, operative time, estimated blood loss, and administration of packed red blood cells were higher in the Jackson spinal table group than in the Wilson frame group (P < 0.001). However, the incidence of AKI was less with the Jackson spinal table than with the Wilson frame (1.7% vs. 3.7%, 2.25 [0.978-5.175], P = 0.056), not reaching statistical significance.

    Conclusion

    This analysis showed that postoperative AKI in patients undergoing spine surgery in the prone position was not different with the Wilson frame than in the Jackson spinal table despite higher surgical severity, longer operative times, and more blood loss in the latter group. In spine surgery, the appropriate selection of prone positioning apparatus can potentially be an important consideration in reducing the risk of AKI.
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    ItemOpen Access
    Surgical management of complex spinal deformity.
    (The Orthopedic clinics of North America, 2012-01) Erickson, Melissa M; Currier, Bradford L
    Surgical treatment of complex cervical spinal deformities can be challenging operations. Patients often present with debilitating conditions ranging from generalized decreased quality of life to quadriplegia. Surgical treatment can be divided into anterior, posterior, or combined procedures. A thorough understanding of anatomy, pathology, and treatment options is necessary. This article focuses on the surgical treatment of complex spinal deformity.
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    ItemOpen Access
    Ventilator Mode Does Not Influence Blood Loss or Transfusion Requirements During Major Spine Surgery: A Retrospective Study.
    (Anesthesia and analgesia, 2020-01) Dunn, Lauren K; Taylor, Davis G; Chen, Ching-Jen; Singla, Priyanka; Fernández, Lucas; Wiedle, Christopher H; Hanak, Mark F; Tsang, Siny; Smith, Justin S; Shaffrey, Christopher I; Nemergut, Edward C; Durieux, Marcel E; Blank, Randal S; Naik, Bhiken I

    Background

    Blood loss during adult spinal deformity surgery is multifactorial. Anesthetic-related factors, such as mode of mechanical ventilation, may contribute to intraoperative blood loss. The aim of this study was to determine the influence of ventilator mode and ventilator parameters on intraoperative blood loss and transfusion requirements in patients undergoing prone position spine surgery.

    Methods

    This single-center retrospective study examined electronic medical records of patients ≥18 years of age who underwent elective prone position spine surgery between May 2015 and June 2016. Associations between ventilator mode and ventilator parameters with intraoperative estimated blood loss (EBL), packed red blood cells (PRBCs), fresh-frozen plasma (FFP), cryoprecipitate and platelet transfusions, and subfascial drain output were examined using multiple linear regression models controlling for age, sex, American Society of Anesthesiologist (ASA) physical status score, body mass index (BMI), preoperative blood coagulation parameters and laboratory values, operative levels, cage constructs, osteotomies, transforaminal lumbar interbody fusions, laminectomies, reoperation, spine surgery invasiveness index, and operative time. In a secondary analysis, EBL, blood product transfusions, and postoperative drain output were compared between pressure-controlled ventilation (PCV) and volume-controlled ventilation (VCV) propensity score-matched cohorts.

    Results

    Nine hundred forty-six records were reviewed, and 822 were included in the analysis. After adjusting for confounding, no statistically significant associations were observed between mode of ventilation and intraoperative EBL (estimate, -2; 95% confidence interval [CI], -248 to 245; P = .99) or blood product transfusions (PRBC: estimate, -9; 95% CI, -154 to 135; P = .90; FFP: estimate, -3; 95% CI, -59 to 54; P = .93; cryoprecipitate: estimate, -14; 95% CI, -70 to 43; P = .63; platelets: -7; 95% CI, -39 to 24; P = .64). After propensity score matching (n = 27 per group), no significant differences were observed in EBL (mean difference, 525 mL; 95% CI, -15 to 1065; P = .056) or blood transfusions (PRBC: mean difference, 208 mL; 95% CI, -23 to 439; P = .077; FFP (mean difference, 34 mL; 95% CI, -17 to 84; P = .19); cryoprecipitate (mean difference, 55 mL; 95% CI, -24 to 133; P = .17); or platelets (mean difference, 26 mL; 95% CI, -12 to 64; P = .18) between PCV and VCV groups.

    Conclusions

    In prone position spine surgery, neither mode of mechanical ventilation nor airway pressure is associated with intraoperative blood loss or need for allogeneic transfusion. Use of modern ventilation strategies using lung protective techniques may mitigate differences in blood loss previously observed between PCV and VCV modes.