Minimally Invasive Robotic-Assisted Thoracic Spine Surgery

30 Minimally Invasive Robotic-Assisted Thoracic Spine Surgery

Mick J. Perez-Cruet and Jorge Mendoza-Torres

Abstract

This chapter discusses the minimally invasive assisted robotic spine surgery (MARSS) for resection of paraspinal tumors. This advanced minimally invasive robotic-guided technique for removal of thoracic tumors is particularly ideal for patients with well-circumscribed apical lung tumors that can be difficult to resect using traditional thoracotomy approaches. Additionally, MARSS avoids the morbidity of open thoracotomy approaches and the technical limitations of thoracoscopic techniques. This chapter reviews the preoperative workup and approach developed that facilitates removal of thoracic tumors. This technique does require specialized training and equipment including use of the da Vinci robotic surgical system. With further refinements in instrumentation, this approach will expand in its indications and ultimately result in improved patient outcomes.

Keywords: MARSS, da Vinci robot, thoracic tumors, minimally invasive

30.1 Introduction

The da Vinci robotic surgical system has been in use since its Food and Drug Administration (FDA) approval in 2000 and was initially approved for use in general, urologic, and gynecologic laparoscopic procedures.¹ During this time period, the da Vinci System has also been indicated for thoracic surgeries of the lungs, mediastinum, and esophagus. These include lung resection, parathyroid gland resection, and thymectomy among others.² Furthermore, we have described use of the da Vinci system in combination with minimally invasive surgery (MIS) posterior approach for the resection of complex paraspinal schwannomas with thoracic extension.³ Minimally invasive robotic surgery has also been shown to potentially provide patients with better outcomes and fewer complications, as well as a cost-effective alternative to traditional open procedures.⁴

In this chapter, we will describe our technique that we call minimally invasive assisted robotic spine surgery (MARSS) for resection of paraspinal tumors using the da Vinci robotic system. However, the da Vinci robot could potentially be used for sympathectomies for palmar hydrosis, trauma, and degenerative disc conditions. The main limitation of this system for expanded indications is the lack of the necessary surgical tools needed by the surgeon.

30.2 Indications and Contraindications

As described earlier, the initial use of the da Vinci robotic surgical systems covered the following:

• General surgery.⁵

• Urologic surgery.⁵

• Gynecologic laparoscopic procedures.⁵

• Thoracic surgery of the lungs, mediastinum, and esophagus, including the following:

◦ Lung resection, parathyroid gland resection, and thymectomy.²

◦ Minimally invasive resection of complex paraspinal schwannomas with thoracic extension.³

A lack of long-term outcomes and quality of life data for da Vinci robotic procedures in the spine precludes a meaningful comparison with open approaches. Thus, few contraindications to using the da Vinci system have been defined, though contraindications are expected to be similar to thoracoscopic procedures and include significant pleural scarring that may precludes a safe approach. Additionally, use of the da Vinci robotic system requires specialized surgeon training.

30.3 Preoperative Planning

Patients typically present with apical thoracic lesions. An “ideal” patient in our opinion has well-circumscribed lesions such as schwannomas. As better instrumentation for spinal surgery using the da Vinci system is developed, the indications should expand. For patients presenting with apical thoracic schwannomas, imaging studies include contrasted thoracic spinal MRI. Contrast-enhanced CT is also useful for accurately identifying the level of origin and determining the neural foramen from which the tumors originate ( Fig. 30.1). This is critical to the resection of the tumor attached to the exiting nerve root to avoid traction injury to the spinal cord and/or root evulsion. A sagittal CT starting at the sacrum can help accurately determine the level of the lesion. For proper surgical level determination, the following images are ordered: chest X-ray and thoracic and lumbar anteroposterior (AP) and lateral images. Intraoperative fluoroscopy is used to accurately determine the level by counting vertebral bodies starting at the sacrum or ribs on the AP chest view. In the case of removal of thoracic schwannomas, no implant instrumentation is needed.

30.4 Surgical Technique

The patient is initially positioned in the prone position on a Jackson table or Wilson frame with all pressure points adequately padded. Double-lumen intubation is done to allow collapsing of the lung on the thoracic approach side. Intraoperative electrophysiologic monitoring is used to measure somatosensory evoked potentials and motor evoked potentials. AP and lateral fluoroscopy is used to help localize the level. An incision is then made lateral to the midline based on preoperative image analysis ( Fig. 30.2). A muscle dilating technique is used to approach the spine over which a tubular retractor is placed. Under microscopic visualization, the ipsilateral lamina and facet are exposed. A bone cutting drill with an M8 cutting burr is used to perform an adequate ipsilateral laminectomy and facetectomy, exposing the tumor within the neural foramen and the dura. The contralateral aspect of the spine is not dissected. The drilled bone is collected using a BoneBac Press (Thompson MIS; Fig. 30.3). The sheath of the tumor is opened and the tumor is removed in a piecemeal fashion. If the exiting nerve root is infiltrated in tumor, it is ligated with silk ties. To prevent potential cerebral spinal leakage into the thoracic cavity, the area can be covered with Gelfoam and thrombin sealant. Once complete hemostasis is achieved, the facet and laminectomy defects are reconstructed using the morselized autograft that was collected in the BoneBac Press ( Fig. 30.4). Gross total removal of the tumor extending into the spinal canal is achieved ( Fig. 30.5). The tubular retractor is removed, allowing the paraspinous muscles to return to their normal anatomic position. The fascia is closed using 2–0 interrupted Vicryl suture. A subcuticular interrupted suture is applied and the skin incision is closed with skin glue.

Fig. 30.1 Tumor extending out of the right T2–T3 neural foramen into the right chest cavity. (a) Axial CT. (b) Chest radiography. (c) Coronal view. (d) Sagittal view. (e) Axial contrast-enhanced MRI.

The patient is then repositioned in the lateral position on a sandbag to allow for adequate unilateral thoracic approach to the tumor. A thoracoscope can then be used for proper port placement ( Fig. 30.6). Thoracoscopic ports are placed and the da Vinci robot is positioned adequately. Instruments are placed in the da Vinci robot for retraction of the tumor and cautery removal of the tumor from the chest cavity. A separate port is used to place a suction to remove cautery smoke. Detaching the tumor from its spinal canal attachment allows for gross total removal and limits potential traction injury to the spinal cord. Once the tumor is resected, it can be placed into a gallbladder bag and removed via one of the thoracoscopic ports. The thoracic ports are moved, a chest tube is placed, and the incisions are closed in a routine fashion. Reinflation of the lung is performed before the final closure. Patients are typically transferred to the intensive care unit for at least an overnight stay.

Fig. 30.2 (a) Axial contrast-enhanced MRI used to identify skin incision location 3 cm lateral to the midline. (b) Patient in the prone position for first stage of the procedure. (c) Use of tubular retractor to remove the posterior portion of the tumor extending from the spinal canal into the thoracic cavity.

30.5 Clinical Cases

30.5.1 Case 1: Schwannoma Lesion

The patient presented with symptoms of upper thoracic chest pain and discomfort. Imaging studies revealed a right apical thoracic mass, which extended out of the right T2–T3 neural foramen ( Fig. 30.1). The tumor was biopsied and found to be a schwannoma. The patient was in his 70 s and had a history of cerebral stroke and had multiple other medical comorbidities, making him a poor surgical candidate. The patient initially underwent focused radiation to the tumor; however, the tumor continued to grow and the patient’s symptoms increased. He was deemed a good candidate for a minimally invasive spinal approach using the da Vinci robot since his medical condition precluded an open thoracotomy. The patient was initially placed prone on a radiolucent Jackson table (Mizuho OSI), and the tumor level was determined with AP thoracic fluoroscopy, counting from the first rib to the location of the tumor. A 2-cm incision parallel to the spinous processes was made approximately 3 cm lateral to the midline, based on preoperative MRI imaging ( Fig. 30.2). Serial muscle dilation was used to dock a tubular retractor on the right T2–T3 facet complex using fluoroscopic guidance. A small amount of soft tissue was removed using a Bovie cautery to expose the facet complex and ipsilateral lamina. Laminectomy and facetectomy were performed to expose the intraspinal portion of the tumor. All drilled bone was collected using the BoneBac Press (Thompson MIS) and used to reconstruct the lamina and facet after tumor resection ( Fig. 30.3). The tumor sheath was cut, and the tumor was debulked in a piecemeal fashion. Duragen (Integra LifeSciences) and Tisseel (Baxter) were placed over the dura to prevent cerebrospinal fluid leakage into the thoracic cavity. Morselized autologous bone collected during the procedure with the BoneBac Press (Thompson MIS) was used to perform a posterolateral arthrodesis at the T2–T3 level ( Fig. 30.4). The intraspinal component of the tumor was gross totally removed ( Fig. 30.5). The retractor was removed, and the incision closed in a routine manner.