Lateral Transpsoas Retractor Technology

Fig. 14.1
Photograph showing the MaXcess® (NuVasive, Inc.) retractor with detachable handle, table mount, and anterior retractor


Fig. 14.2
Intraoperative illustrations showing evoked-EMG stimulation in MaXcess off the posterior (center) blade electrode over the sequential dilators while rotating (a, b) the retractor to provide directional and distance EMG information about motor nerves posterior to the retractor

The MaXcess retractor’s primary feature is a split-blade design, with three main blades, one in the posterior orientation to the surgical approach and one each in cranial and caudal orientations (Fig. 14.3). The diameter of the closed blades is approximately 12 mm. Each of these blades can be manipulated independently of each other both to retract separately in cranial, caudal, and/or anterior orientations (by the cranial-caudal blades) simultaneously and posteriorly, if needed, by the posterior blade (Fig. 14.4). Each of the cranial and caudal blades can also be splayed either inwardly or outwardly to allow for additional or less cranial or caudal surgical site exposure without extension of the surgical incision (Fig. 14.5). Light sources are placed into each of the cranial and caudal blades for visualization of the lateral disk and working space (Fig. 14.6). A shim is placed down the posterior blade and into the disk space to hold the retractor in the chosen position. A fourth retractor blade can be placed anterior to the cranial and caudal blades, primarily to realize the potential space anterior to the anterior longitudinal ligament (ALL) or to provide a barrier between those structures and the working space (Fig. 14.1). Intraoperatively, the MaXcess retractor allows for broad visibility of the working corridor and disk space (Fig. 14.7).


Fig. 14.3
Illustration of the surgeon’s point of view in XLIF® (NuVasive, Inc.), with the three unretracted blades of the MaXcess retractor (posterior, cranial, and caudal) with a K-wire in the disk space and the NVM5® (NuVasive, Inc.) stimulating electrode shown in the posterior blade


Fig. 14.4
Lateral illustration showing the MaXcess retractor with anterior-only retraction by the cranial and caudal retractor blades with the posterior blade NVM5 EMG electrode and visual discrete threshold feedback clip (green clip on electrode)


Fig. 14.5
Anterior illustration of XLIF with MaXcess showing individual blade splay for surgical site expansion or retraction without change in incision size


Fig. 14.6
Surgeon’s point of view illustration in XLIF showing the MaXcess retractor with lighting elements in place in each of the cranial and caudal blades


Fig. 14.7
Anterior intraoperative fluororadiography showing and XLIF corpectomy using the MaXcess retractor and the anterior (fourth blade) spatula attachment for lung deflection

Categorically, the features of the MaXcess retractor include:

  • Access: Sequential dilation under real-time, surgeon-directed, evoked EMG with discrete threshold responses in directional orientations.

  • Mounting: Table mounted.

  • Blades: Split, with three blades, with each retractable separately and with inward and outward splay capabilities for the cranial and caudal blades. Optional fourth blades include ALL retractor or spatula accessories, the latter for tumor, trauma, and thoracic applications (Fig. 14.8). The closed retractor diameter is 12 mm.


    Fig. 14.8
    (a) Lateral intraoperative fluororadiograph showing exposure and imaging view capability with the MaXcess retractor in XLIF. (b) Anterior intraoperative fluororadiograph showing the posterior blade shim in place in the disk with limited retraction to expose only the disk

  • Neuromonitoring: Evoked EMG (NVM5) integrated into approach (dilator) and procedural instrumentation, including the posterior blade of the retractor (Fig. 14.9).
Sep 23, 2017 | Posted by in NEUROLOGY | Comments Off on Lateral Transpsoas Retractor Technology
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