Posterior approach for plexus tumors in the apical and mediastinal regions

Abstract

I enjoyed Ladas and colleagues’ [1Ladas G. Rhys-Evans P. Goldstraw P. Anterior cervical transsternal approach for resection of benign tumors at thoracic outlet.Ann Thorac Surg. 1999; 67: 785-789Abstract Full Text Full Text PDF PubMed Scopus (32) Google Scholar] description of an anterior cervical transsternal approach for resection of four neural tumors at the apex of the lung and thoracic inlet. This appears to be a very direct and thus useful approach to the upper mediastinum. I have not had experience with the authors’ technique but have had a relatively large experience with posterior subcapular exposure usually with removal of the posterior portion of the first and occasionally the second rib. Such an approach was modified from that proposed by Clagett [2Clagett O.T. Research and proresearch.J Thorac Cardiovasc Surg. 1962; 44: 153-166PubMed Google Scholar] for thoracic outlet syndrome. This subcapular approach has been useful for some medial traumatic injuries to the plexus, complex and previously operated thoracic outlet cases, some cases of irradiation plexitis, as well as selected plexus tumors [3Kline D. Kott J. Barnes G. Bryant L. Exploration of selected brachial plexus lesions by the posterior subscapular approach.J Neurosurg. 1978; 49: 872-880Crossref PubMed Scopus (33) Google Scholar, 4Horowitz J. Kline D. Keller S. Schwannoma of the brachial plexus mimicking an apical lung tumor.Ann Thorac Surg. 1991; 52: 555-556Abstract Full Text PDF PubMed Scopus (14) Google Scholar]. Most of the tumors that are benign in this area are of neural sheath origin such as schwannomas and neurofibromas either in association or not with von Recklinghausen’s disease. Thus, apical and mediastinal tumors when neural in origin usually arise within a plexus element such as a nerve root or plexus trunk. They often have intraforaminal as well as extraforaminal involvement and on occasion can even extend into the spinal canal. The posterior subscapular approach permits a posterior foraminotomy and thus an approach to the intraforaminal portion of such lesions away from the vertebral artery. If need be, a semihemilaminectomy or even laminectomy can also be done from this approach and yet the apical pleural and mediastinal portions of the tumor can be removed satisfactorily. These tumors are usually intraneural in origin so an intraneural dissection is necessary to work tumor away from fascicles as well as adjacent plexus elements. This is a different type of dissection than might be used for tumors of sympathetic chain origin such as the authors’ cases 1 to 3 but might have been used in their case 4 to spare as much neural function as possible. This is, of course, something that is not always possible with any approach including the posterior subcapular one. In a series reported in 1993 there were 22 neural tumors operated upon satisfactorily in this fashion. Included were five schwannomas, ten neurofibromas, three neurogenic sarcomas of the plexus, two ganglioneuromas, one lymphangioma, and one plasmocytoma [5Dubuison A. Kline D. Weinshel S. Posterior subscapular approach to the brachial plexus. Report of 101 cases.J Neurosurg. 1993; 79: 319-330Crossref PubMed Scopus (52) Google Scholar]. Since then my group has operated on an additional 12 medially located lower plexus element tumors by the posterior subcapular route. Indications for the posterior subcapular approach for apical plexus lesions include (1) tumors involving the plexus and extending into the mediastinum or compressing apical pleural/lung, (2) tumors with both intraforaminal as well as extraforaminal and lateral components, and (3) especially tumors involving lower plexus elements such as C7, C8, T1, and middle and lower trunks. Although the incidence of complications is low, they can occur and these include (1) scapular winging (4%), (2) instability of cervical spine and need for fixation if a number of facets are removed, and (3) pleural tears, pneumothorax or hemothorax or phrenic nerve palsy, vascular injury, or new and further damage to the plexus. These latter difficulties also can occur with any anterior operation. However, there has been one operative death recently due to uncontrollable bleeding from a massive tumor and the mediastinal portion of the subclavian artery. The anterior cervical transsternal approach appears useful for some apical neural tumors but it may not provide the exposure necessary for neural sheath tumors that are intraforaminal, intraspinal, or extend laterally in the plexus. Need for an intraneural as well as extensive plexus dissection favors a larger exposure as provided by the posterior subscapular route.