Uniport video-assisted thoracoscopic surgery for thoracic Eden type IV dumbbell tumor

A 27-year-old woman without any significant history was referred to our clinic for a well-defined soft-tissue lesion in the left apical thorax. The patient was asymptomatic. T-spine magnetic resonance imaging revealed a dumbbell tumor 31 mm in length and 25 mm in width extending into the left T2-T3 intervertebral foramen with T2 hyperintensity. The left pedicle of T2 was eroded by the tumor, so the width of its neuroforamen was 3 times wider than the normal side (Figure 1). A multidisciplinary surgical team consisting of a thoracic surgeon, a neurosurgeon, and a neurologist discussed the surgical principle. The patient provided written informed consent for publication of the case, and institutional review board approval was not required.

Under general anesthesia, the patient was intubated with a double-lumen endotracheal tube and placed in the prone position for the possible contingency of laminectomy via a posterior approach. A 3-cm incision was made over the left mid-axillary line at the fourth intercostal space level (Figure 2, A). The key point of this skin incision for uniport VATS was to incise along the line of tumor, aortic arch, and wound to avoid intense jamming and interference with instruments. The parietal pleura around the tumor's posterior mediastinal area was carefully excised using an ultrasonic scalpel. There was an intact arachnoid membrane between the sympathetic trunk and tumor capsule. The intercostal vessels were separated and clamped safely. Once the tumor sufficiently mobilized and dissected into neuroforamen, we changed to both blunt dissection and the use of a bipolar device to minimize energy spreading and reduce potential damage to the dura and spinal cord. The other key for uniport VATS was to minimize excessive traction of the tumor to avoid spinal cord injury and bleeding. Blunt dissection was applied between the tumor and spinal dura to avoid tearing of the spinal dura. A hemoclip was applied at the tumor base and dura to avoid cerebrospinal fluid leakage (Figure 2, B and Video 1). A 14-Fr pigtail drain was inserted. The surgical time was 80 minutes, and total blood loss was 100 mL. We removed the pigtail drainage on postoperative day 1, and the patient was discharged on postoperative day 2 without neurologic deterioration. Pathology showed schwannoma with a well-demarcated capsule without rupture.

A dumbbell tumor was reported to be treated with wide posterolateral thoracotomy and concomitant laminectomy in 1983. The complications included excessive operative time, blood loss, and tissue damage. As instruments and surgical technology improved over time, complex uniport VATS intervention became viable and resulted in reduced tissue damage. Gonzalez-Rivas and colleagues introduced the use of uniport thoracoscopic lobectomy in 2011. To the best of our knowledge, there has been no previous surgical report on uniport VATS dumbbell tumor resection.

Most dumbbell tumors are well capsuled with benign origin, and more than 60% are schwannomas. Eden type IV dumbbell tumors involve foraminal and mediastinal components; consequently, a posterior approach is a challenging task and not necessarily needed. In the past, it was the standard treatment. Uniport VATS can provide clear exposure and preserve facet joints, lamina, and ligaments.

Some scholars have suggested it is unsafe to remove a tumor without first separating the tumor from its attachment to the spinal cord. Percutaneous spinal endoscopy combined with thoracoscopy has been reported. However, type IV dumbbell tumors do not invade the spinal canal and do not closely adhere to the spinal dura. Intraoperative nerve monitoring is not necessary as well. We demonstrated that the attachment to the spinal cord of a type IV dumbbell tumor can be identified clearly and cut off under uniport VATS. We suggest that uniport VATS for type IV dumbbell tumor resection is a safe, feasible procedure. It provides clear exposure, less bony resection, less tissue trauma, and better recovery.