Biomechanical Effects of Facet Joint Violation After Single-Level Lumbar Fusion With Transpedicular Screw and Rod Instrumentation.

STUDY DESIGN: In vitro biomechanical study. OBJECTIVE: This study aimed to investigate the biomechanical effects of facet joint violation (FV) on mobility and optically tracked intervertebral disc (IVD) surface strains at the upper level adjacent to L4-5 pedicle screw-rod fixation. SUMMARY OF BACKGROUND DATA: FV is a complication that can occur when placing lumbar pedicle screws; the reported incidence is as high as 50%. However, little is known about how FV affects superior adjacent-level spinal stability, and especially IVD strain, after lumbar fusion. METHODS: Fourteen cadaveric L3-S1 specimens underwent L4-5 pedicle-rod fixation, 7 in the facet joint preservation (FP) group and 7 in the FV group. Specimens were tested multidirectionally under pure moment loading (7.5 Nm). Colored maps of maximum (ε1) and minimum (ε2) principal surface strain changes on the lateral L3-4 disc were generated, with the surface divided into 4 quarters anterior to posterior (Q1, Q2, Q3, and Q4, respectively) for subregional analyses. Range of motion (ROM) and IVD strain were normalized to intact upper adjacent-level and compared between the groups using analysis of variance. Statistical significance was set at P <0.05. RESULTS: Normalized ROM was significantly greater with FV vs. FP in flexion (11% greater; P =0.04), right lateral bending (16% greater; P =0.03), and right axial rotation (23% greater; P =0.04). Normalized L3-4 IVD ε1 during right lateral bending was greater on average for the FV group than the FP group: Q1, 18% greater; Q2, 12% greater; Q3, 40% greater ( P <0.001); Q4, 9% greater. Normalized ε2 values during left axial rotation were greater in the FV group, the highest increase being 25% in Q3 ( P =0.02). CONCLUSIONS: Facet joint violation during single-level pedicle screw-rod fixation was associated with increased superior adjacent level mobility and alteration of disc surface strains, with significant increases in selected regions and directions of loading.

Biomechanical Assessment of a Novel Sharp-Tipped Screw for 1-Step Minimally Invasive Pedicle Screw Placement Under Navigation.

BACKGROUND: The objective of this study was to assess the pullout force of a novel sharp-tipped screw developed for single-step, minimally invasive pedicle screw placement guided by neuronavigation compared with the pullout force for traditional screws. METHODS: A total of 60 human cadaveric lumbar pedicles were studied. Three different screw insertion techniques were compared: (A) Jamshidi needle and Kirschner wire without tapping; (B) Jamshidi needle and Kirschner wire with tapping; and (C) sharp-tipped screw insertion. Pullout tests were performed at a displacement rate of 10 mm/min recorded at 20 Hz. Mean values of these parameters were compared using paired t tests (left vs right in the same specimen): A vs B, A vs C, and B vs C. Additionally, 3 L1-L5 spine models were used for timing each screw insertion technique for a total of 10 screw insertions for each technique. Insertion times were compared using 1-way analysis of variance. RESULTS: The mean pullout force for insertion technique A was 1462.3 (597.5) N; for technique B, it was 1693.5 (805.0) N; and for technique C, it was 1319.0 (735.7) N. There was no statistically significant difference in pullout force between techniques (P > 0.08). The average insertion time for condition C was significantly less than that for conditions A and B (P < 0.001). CONCLUSIONS: The pullout force of the novel sharp-tipped screw placement technique is equivalent to that of traditional techniques. The sharp-tipped screw placement technique appears biomechanically viable and has the advantage of saving time during insertion. CLINICAL RELEVANCE: Single-step screw placement using high resolution 3-dimensional navigation has the potential to streamline workflow and reduce operative time.

Rod Attachment Induces Significant Strain in Lumbosacral Fixation.

STUDY DESIGN: This was a laboratory investigation. OBJECTIVE: Rod attachment can induce significant pedicle screw-and-rod pre- strain that may predispose the instrumentation to failure. This study investigated how in vitro L5-S1 rod strain and S1 screw strain during rod-screw attachment (pre-strain) compared with strains recorded during pure-moment bending ( test- strain). SUMMARY OF BACKGROUND DATA: The lumbosacral junction is highly vulnerable to construct failure due to rod fatigue fracture, sacral screw pull-out, and screw fatigue fracture. MATERIALS AND METHODS: Twelve cadaveric specimens were instrumented with L2-ilium pedicle screws and rod. Strain gauges on contoured rods and sacral screws recorded strains during sequential rod-to-screw tightening (pre-strains). The same instrumented constructs were immediately tested in a 6-degree-of-freedom apparatus under continuous loading to 7.5 Nm in multidirectional bending while recording instrumentation test-strains. Rod and screw pre-strains and test-strains were compared using 1-way repeated-measures analysis of variance followed by Holm-Sidák paired analysis (significant at P <0.05). RESULTS: The mean first (171±192 µE) and second (322±269 µE) rod attachment pre-strains were comparable to mean test-strains during flexion (265±109 µE) and extension (315±125 µE, P ≥0.13). The mean rod attachment pre-strain was significantly greater than mean test-strains during bidirectional lateral bending (40±32 µE ipsilateral and 39±32 µE contralateral, P <0.001) and axial rotation (72±60 µE ipsilateral and 60±57 µE contralateral, P <0.001). The mean first and second sacral screw pre-strains during rod attachment (1.03±0.66 and 1.39±1.00 Nm, respectively) did not differ significantly ( P =0.41); however, the mean sacral screw pre-strain during final (second) rod attachment was significantly greater than screw test-strains during all directions of movement (≤0.81 Nm, P ≤0.03). CONCLUSIONS: Instrumentation pre-strains imposed during in vitro rod-screw attachment of seemingly well-contoured rods in L2-ilium fixation are comparable to, and at times greater than, strains experienced during in vitro bending. Spine surgeons should be aware of the biomechanical consequences of rod contouring and attachment on construct vulnerability.

Biomechanical Effects of Proximal Polyetheretherketone Rod Extension on the Upper Instrumented and Adjacent Levels in a Human Long-Segment Construct: A Cadaveric Model.

OBJECTIVE: The high mechanical stress zone at the sudden transition from a rigid to flexible region is involved in proximal junctional kyphosis (PJK) physiopathology. We evaluated the biomechanical performance of polyetheretherketone (PEEK) rods used as a nontraditional long semirigid transition phase from a long-segment metallic rod construct to the nonfused thoracic spine. METHODS: Pure moment range of motion (ROM) tests (7.5 Nm) were performed on 7 cadaveric spine segments followed by compression (200 N). Specimens were tested in the following conditions: (1) intact; (2) T10-pelvis pedicle screws and rods (PSRs); and (3) extending the proximal construct to T6 using PEEK rods (PSR+PEEK). T10-11 rod strain, T9 anterolateral bone strain, and T10 screw bending moments were analyzed. RESULTS: At the upper instrumented vertebra (UIV)+1, PSR+PEEK versus PSR significantly decreased ROM in flexion (115%, p = 0.02), extension (104%, p = 0.003), left lateral bending (46%, p = 0.02), and right lateral bending (63%, p = 0.008). Also, at UIV+1, PSR+PEEK versus intact significantly decreased ROM in flexion (111%, p = 0.01) and extension (105%, p = 0.003). The UIV+1 anterior column bone strain was significantly reduced with PSR+PEEK versus PSR during right lateral bending (p = 0.02). Rod strain polarities reversed with PEEK rods in all loading directions except compression. CONCLUSION: Extending a long-segment construct using PEEK rods caused a decrease in adjacent-level hypermobility as a consequence of long-segment immobilization and also redistributed the strain on the UIV and adjacent levels, which might contribute to PJK physiopathology. Further studies are necessary to observe the clinical outcomes of this technique.

Impact of Intraoperative Magnetic Resonance Imaging (i-MRI) on Surgeon Decision Making and Clinical Outcomes in Cranial Tumor Surgery.

Background Although intraoperative magnetic resonance imaging (iMRI) has an established role in guiding intraoperative extent of resection (EOR) in cranial tumor surgery, the details of how iMRI data are used by the surgeon in the real-time decision-making process is lacking. Materials and Methods The authors retrospectively reviewed 40 consecutive patients who underwent cranial tumor resection with the guidance of iMRI. The tumor volumes were measured by volumetric software. Intraoperative and postoperative EOR were calculated and compared. Surgeon preoperative EOR intention, intraoperative EOR assessment, and how iMRI data impacted surgeon decisions were analyzed. Results The pathology consisted of 29 gliomas, 8 pituitary tumors, and 3 other tumors. Preoperative surgeon intention called for gross total resection (GTR) in 28 (70%) cases. After resection and before iMRI scanning, GTR was 20 (50.0%) cases based on the surgeon's perception. After iMRI scanning, the results helped identify 19 (47.5%) cases with unexpected results consisting of 5 (12.5%) with unexpected locations of residual tumors and 14 (35%) with unexpected EOR. Additional resection was performed in 24 (60%) cases after iMRI review, including 6 (15%) cases with expected iMRI results. Among 34 cases with postoperative MRI results, iMRI helped improve EOR in 12 (35.3%) cases. Conclusion In cranial tumor surgery, the surgeon's preoperative and intraoperative assessment is frequently imprecise. iMRI data serve several purposes, including identifying the presence of residual tumors, providing residual tumor locations, giving spatial relation data of the tumor with nearby eloquent structures, and updating the neuro-navigation system for the final stage of tumor resection.

Rolandic Cortex Morphology: Magnetic Resonance Imaging-Based Three-Dimensional Cerebral Reconstruction Study and Intraoperative Usefulness.

Background During brain surgery, the neurosurgeon must be able to identify and avoid injury to the Rolandic cortex. However, when only a small part of the cortex is exposed, it may be difficult to identify the Rolandic cortex with certainty. Despite various advanced methods to identify it, visual recognition remains an important backup for neurosurgeons. The aim of the study was to find any specific morphology pattern that may help to identify the Rolandic cortex intraoperatively. Materials and Methods Magnetic resonance imaging of the brain from patients with various conditions was used to create the three-dimensional cerebral reconstruction images. A total of 216 patients with 371 intact hemispheres were included. Each image was inspected to note the morphology of the Rolandic cortex and the suprasylvian cortex. Additionally, other two evaluators exclusively inspected the morphology of the suprasylvian cortex. Their observation results were compared to find the agreements. Results Several distinctive morphology patterns have been identified at the Rolandic cortex and the suprasylvian cortex including a genu, or a knob at the upper precentral gyrus, an angulation of the lower postcentral gyrus, a strip for pars opercularis, a rectangle for the lower precentral gyrus, and a triangle for the lower postcentral gyrus. Combined total and partial agreement of the suprasylvian cortex morphology pattern ranged from 60.4 to 85.2%. Conclusion The authors have demonstrated the distinctive morphology of the Rolandic cortex and the suprasylvian cortex. This information can provide visual guidance to identify the Rolandic cortex particularly during surgery with limited exposure.

Subtle segmental angle changes of single-level lumbar fusions and adjacent-level biomechanics: cadaveric study of optically measured disc strain.

OBJECTIVE: Changes to segmental lordosis at a single level may affect adjacent-level biomechanics and overall spinal alignment with an iatrogenic domino effect commonly seen in adult spinal deformity. This study investigated the effects of different segmental angles of single-level lumbar fixation on stability and principal strain across the surface of the adjacent-level disc. METHODS: Seven human cadaveric L3-S1 specimens were instrumented at L4-5 and tested in 3 conditions: 1) neutral native angle ("neutral"), 2) increasing angle by 5° of lordosis ("lordosis"), and 3) decreasing angle by 5° of kyphosis ("kyphosis"). Pure moment loads (7.5 Nm) were applied in flexion, extension, lateral bending, and axial rotation, followed by 400 N of axial compression alone and together with pure moments. Range of motion (ROM), principal maximum strain (E1), and principal minimum strain (E2) across different surface subregions of the upper adjacent-level disc (L3-4) were optically assessed. Larger magnitudes of either E1 or E2 indicate larger tissue deformations and represent indirect measures of increased stress. RESULTS: At the superior adjacent level, a significant increase in ROM was observed in kyphosis and lordosis versus neutral in flexion (p ≤ 0.001) and extension (p ≤ 0.02). ROM was increased in lordosis versus neutral (p = 0.03) and kyphosis (p = 0.004) during compression. ROM increased in kyphosis versus neutral and lordosis (both p = 0.03) in compression plus extension. Lordosis resulted in increased E1 across the midposterior subregion of the disc (Q3) versus neutral during right lateral bending (p = 0.04); lordosis and kyphosis resulted in decreased E1 in Q3 versus neutral with compression (p ≤ 0.03). Lordosis decreased E1 in Q3 versus neutral during compression plus flexion (p = 0.01), whereas kyphosis increased E1 in all quartiles and increased E2 in the midanterior subregion versus lordosis in compression plus flexion (p ≤ 0.047). Kyphosis decreased E1 in Q3 (p = 0.02) and E2 in the anterior-most subregion of the disc (Q1) (p = 0.006) versus neutral, whereas lordosis decreased E1 in Q3 (p = 0.008) versus neutral in compression plus extension. CONCLUSIONS: Lumbar spine monosegmental fixation with 5° offset from the neutral individual segmental angle altered the motion and principal strain magnitudes at the upper adjacent disc, with induced kyphosis resulting in larger principal strains compared with lordosis. Segmental alignment of single-level fusion influences adjacent-segment biomechanics, and suboptimal alignment may play a role in the clinical development of adjacent-segment disease.

Biomechanics of a laterally placed sacroiliac joint fusion device supplemental to S2 alar-iliac fixation in a long-segment adult spinal deformity construct: a cadaveric study of stability and strain distribution.

OBJECTIVE: S2 alar-iliac (S2AI) screw fixation effectively enhances stability in long-segment constructs. Although S2AI fixation provides a single transarticular sacroiliac joint fixation (SIJF) point, additional fixation points may provide greater stability and attenuate screw and rod strain. The objectives of this study were to evaluate changes in stability and pedicle screw and rod strain with extended distal S2AI fixation and with supplemental bilateral integration of two sacroiliac joint fusion devices implanted using a traditional minimally invasive surgical approach. METHODS: Eight L1-pelvis human cadaveric specimens underwent pure moment (7.5 Nm) and compression (400 N) tests under 4 conditions: 1) intact (pure moment loading only); 2) L2-S1 pedicle screw and rod with L5-S1 interbody fusion; 3) added S2AI screws; and 4) added bilateral laterally placed SIJF. Range of motion (ROM), rod strain, and screw-bending moment (S1 and S2AI) were analyzed. RESULTS: Compared with S1 fixation, S2AI fixation significantly reduced L5-S1 ROM in right lateral bending by 50% (0.11°, p = 0.049) and in compression by 39% (0.22°, p = 0.003). Compared with fixation ending at S1, extending fixation with S2AI significantly decreased sacroiliac joint ROM by 52% (0.28°, p = 0.02) in flexion, by 65% (0.48°, p = 0.04) in extension, by 59% (0.76°, p = 0.02) in combined flexion-extension, and by 36% (0.09°, p = 0.02) in left axial rotation. The addition of S2AI screws reduced S1 screw-bending moment during flexion (0.106 Nm [43%], p = 0.046). With S2AI fixation, posterior L5-S1 primary rod strain increased by 124% (159 µE, p = 0.002) in flexion, by 149% (285 µE, p = 0.02) in left axial rotation, and by 99% (254 µE, p = 0.04) in right axial rotation. Compared with S2AI fixation, the addition of SIJF reduced L5-S1 strain during right axial rotation by 6% (28 µE, p = 0.04) and increased L5-S1 strain in extension by 6% (28 µE, p = 0.02). CONCLUSIONS: Long-segment constructs ending with S2AI screws created a more stable construct than those ending with S1 screws, reducing lumbosacral and sacroiliac joint motion and S1 screw-bending moment in flexion. These benefits, however, were paired with increased rod strain at the lumbosacral junction. The addition of SIJF to constructs ending at S2AI did not significantly change SI joint ROM or S1 screw bending and reduced S2AI screw bending in compression. SIJF further decreased L5-S1 rod strain in axial rotation and increased it in extension.

Placement accuracy of the second electrode in bilateral deep brain stimulation surgery.

PURPOSE: Due to brain shift during bilateral deep brain stimulation (DBS) surgery, placement of the second electrode may be subjected to more error than that of the first electrode. The authors aimed to investigate the accuracy of second electrode placement in this setting. MATERIALS AND METHODS: Fifty-five patients with Parkinson's disease who underwent bilateral DBS surgery (110 electrodes) were retrospectively evaluated. The targets were subthalamic nucleus (STN) and globus pallidus interna (GPi) in 40 and 15 cases, respectively. Preoperative planning and postoperative electrode images were co-registered to compare the error margin between the two sides. RESULTS: There is a statistically significant difference in the directional axis error along the y axis only when comparing each laterality (posterior 0.04 ± 1.21 mm vs anterior 0.41 ± 1.07 mm, p = 0.006). There is no significant difference of other error parameters, final track location, and number of microelectrode recording passes between the two sides. In a subgroup analysis, there is a significant difference in directional axis error along the y axis only in the STN subgroup (posterior 0.40 ± 1.05 mm vs anterior 0.18 ± 1.04 mm, p = 0.003). CONCLUSION: Although a statistically significant difference in directional axis error along the y axis was found between first and second electrode placements in the STN group but not in the GPi group, its magnitude is well below the clinically significant threshold.

Does the Choice of Spinal Interbody Fusion Approach Significantly Affect Adjacent Segment Mobility?

STUDY DESIGN: Biomechanical study of range of motion (ROM) at the vertebral levels adjacent to the construct of posterior pedicle screw-rod fixation with different types of lumbar interbody fusion techniques (LIF). OBJECTIVE: To investigate the differences in adjacent segment mobility among three types of LIF: lateral lumbar interbody fusion (LLIF), transforaminal lumbar interbody fusion (TLIF), and posterior lumbar interbody fusion (PLIF). SUMMARY OF BACKGROUND DATA: Previous studies have concluded that LLIF, TLIF, and PLIF with posterior pedicle screw-rod fixation (PSR) provide equivalent stability in cadaveric specimens and are comparable in fusion rate and functional outcome. However, long-term complications, such as adjacent segment degeneration associated with each type of interbody device, are currently unclear. Little is known about the biomechanical effects of interbody fusion technique on the mobility of adjacent segments. METHODS: Normalized ROM data at the levels adjacent to L3-L4 PSR fixation with three different types of lumbar interbody fusion approaches (LLIF, TLIF, and PLIF) were analyzed. Intact (n = 21) and instrumented (n = 7 per group) L2-L5 cadaveric specimens were tested multidirectionally under pure moment loading (7.5 Nm). Analysis of variance of adjacent segment ROM among the groups was performed. Statistical significance was set at P < 0.05. RESULTS: Normalized ROM was significantly greater with PLIF than with LLIF in all directions at both proximal and distal adjacent segments (P ≤ 0.02) except for axial rotation at the distal adjacent segment (P = 0.07). TLIF also had greater normalized ROM than LLIF during lateral bending at the proximal adjacent segment (P = 0.008) and during flexion, extension, and lateral bending at the distal adjacent segment (P ≤ 0.03). Normalized ROM was not significantly different between PLIF and TLIF. CONCLUSION: The choice of lumbar interbody fusion approach influences adjacent segment motion in a cadaveric model. LLIF had the least adjacent segment motion.Level of Evidence: 3.

Adjacent-segment effects of lumbar cortical screw-rod fixation versus pedicle screw-rod fixation with and without interbody support.

OBJECTIVE: Cortical screw-rod (CSR) fixation has emerged as an alternative to the traditional pedicle screw-rod (PSR) fixation for posterior lumbar fixation. Previous studies have concluded that CSR provides the same stability in cadaveric specimens as PSR and is comparable in clinical outcomes. However, recent clinical studies reported a lower incidence of radiographic and symptomatic adjacent-segment degeneration with CSR. No biomechanical study to date has focused on how the adjacent-segment mobility of these two constructs compares. This study aimed to investigate adjacent-segment mobility of CSR and PSR fixation, with and without interbody support (lateral lumbar interbody fusion [LLIF] or transforaminal lumbar interbody fusion [TLIF]). METHODS: A retroactive analysis was done using normalized range of motion (ROM) data at levels adjacent to single-level (L3-4) bilateral screw-rod fixation using pedicle or cortical screws, with and without LLIF or TLIF. Intact and instrumented specimens (n = 28, all L2-5) were tested using pure moment loads (7.5 Nm) in flexion, extension, lateral bending, and axial rotation. Adjacent-segment ROM data were normalized to intact ROM data. Statistical comparisons of adjacent-segment normalized ROM between two of the groups (PSR followed by PSR+TLIF [n = 7] and CSR followed by CSR+TLIF [n = 7]) were performed using 2-way ANOVA with replication. Statistical comparisons among four of the groups (PSR+TLIF [n = 7], PSR+LLIF [n = 7], CSR+TLIF [n = 7], and CSR+LLIF [n = 7]) were made using 2-way ANOVA without replication. Statistical significance was set at p < 0.05. RESULTS: Proximal adjacent-segment normalized ROM was significantly larger with PSR than CSR during flexion-extension regardless of TLIF (p = 0.02), or with either TLIF or LLIF (p = 0.04). During lateral bending with TLIF, the distal adjacent-segment normalized ROM was significantly larger with PSR than CSR (p < 0.001). Moreover, regardless of the types of screw-rod fixations (CSR or PSR), TLIF had a significantly larger normalized ROM than LLIF in all directions at both proximal and distal adjacent segments (p ≤ 0.04). CONCLUSIONS: The use of PSR versus CSR during single-level lumbar fusion can significantly affect mobility at the adjacent segment, regardless of the presence of TLIF or with either TLIF or LLIF. Moreover, the type of interbody support also had a significant effect on adjacent-segment mobility.

Rolandic Cortex Morphology: Magnetic Resonance Imaging-Based Three-dimensional Cerebral Reconstruction Study and Intraoperative Usefulness.

BACKGROUND: During brain surgery, the neurosurgeon must be able to identify and avoid injury to the Rolandic cortex. However, when only a small part of the cortex is exposed, it may be difficult to identify the Rolandic cortex with certainty. Despite various advanced methods to identify it, visual recognition remains an important backup for neurosurgeons. The aim of the study was to find any specific morphology pattern that may help to identify the Rolandic cortex intraoperatively. MATERIALS AND METHODS: Magnetic resonance imaging of the brain from patients with various conditions was used to create the three-dimensional cerebral reconstruction images. A total of 216 patients with 371 intact hemispheres were included. Each image was inspected to note the morphology of the Rolandic cortex and the suprasylvian cortex. In addition, other two evaluators exclusively inspected the morphology of the suprasylvian cortex. Their observation results were compared to find the agreements. RESULTS: A number of distinctive morphology patterns have been identified at the Rolandic cortex and the suprasylvian cortex including a genu, or a knob at the upper precentral gyrus (pre-CG), an angulation of the lower postcentral gyrus (post-CG), a strip for pars opercularis, a rectangle for the lower pre-CG, and a triangle for the lower post-CG. Combined total and partial agreement of the suprasylvian cortex morphology pattern ranged 60.4%-85.2%. CONCLUSION: The authors have demonstrated the distinctive morphology of the Rolandic cortex and the suprasylvian cortex. This information can provide visual guidance to identify the Rolandic cortex particularly during surgery with limited exposure.

Catheter guided cerebral glioma resection combined with awake craniotomy: its usefulness and surgical outcome.

Purpose: A challenging aspect of glioma surgery is to distinguish tumour tissue from surrounding eloquent structures and perform resection with accuracy. Various technologies have been used to address this issue including neuronavigator, intraoperative magnetic resonant imaging, intraoperative ultrasound, and fluorescence, each of which has certain drawbacks and limitations. In this study, authors demonstrate the technique of using stereotactically placed catheters as guidance during cerebral glioma resection and report the surgical outcomes. Materials and methods: This study included patients with intrinsic cerebral tumour adjacent to the eloquent structures. Catheter trajectories were planned using three-dimensional cerebral reconstruction on navigation software and catheters were stereotactically placed to mark the intended extent of resection. All craniotomies were performed in awake fashion under neurophysiologic mapping and continuous physical examination for safe maximal resection. Clinical outcome and intended versus actual extent of resection were analysed. Results: Between January 2015 and December 2016, 15 consecutive patients (8 males and 7 females) with intrinsic cerebral tumour underwent craniotomy with this technique. Median age was 43 years. Seven patients (46.7%) had worsening neurological status within 24 h postoperatively. Of these 7 patients, 6 patients (85.7%) regained preoperative neurological status by 6 months. The intended extent of resections were total, subtotal and partial in 3 (20%), 9 (60%), and 3 (20%) patients, respectively. The actual extent of resections were total, subtotal and partial in 3 (20%), 8(53.3%), and 4 (26.7%) patients, respectively. There were no catheter related complications. There was no 30-day postoperative mortality. Conclusions: Catheter guided resection along with awake surgery and neurophysiologic monitoring is a valid technique for infiltrative tumour, especially for ones locating near eloquent structures where the margin of error is low. This is a simple and economical technique which requires only standard equipment widely available to neurosurgical operating theatres.