Minimally invasive/endoscopic vs “open” posterior cervical laminoforaminotomy: do the risks outweigh the benefits?☆

Although the spine literature is increasingly bombarded with minimally invasive alternatives to the posterior cervical laminoforaminotomy, little is stated regarding the “learning curve” for these procedures, and the resultant risks/complications. Although many agree that posterior approaches are optimal to treat lateral/foraminal spondylosis/spur or disk herniations, there is much disagreement regarding the required degree of exposure: microendoscopic, minimally invasive, or the typical “open” key hole foraminotomy. When any of these procedures are performed, careful preoperative screening is mandatory (usually requiring both magnetic resonance and computed tomography–based studies) to ensure that these lateral and foraminal spurs/disks are accessible from a posterior approach. A major concern, however, is that these operations are extremely difficult even with the maximal exposure provided by the open key hole laminoforaminotomy. Optimal exposure is critical to minimize injuries to the exiting nerve root, spinal cord, and/or surrounding structures (ie, vertebral artery). The open procedure, performed under an operating microscope, allows for greater maneuvering with small down-biting curettes and microinstruments to facilitate adequate decompression and resection of spurs and/or disk herniations. There is therefore no restriction of movement or dissection encountered with the open approach as compared with either of the minimally invasive procedures. Furthermore, the greater exposure helps limit major complications (ie, nerve root, spinal cord, vertebral artery, cerebrospinal fluid fistulas). Of interest, several minimally invasive/endoscopic laminoforaminotomy series describe the performance of posterior decompressions alone without the excision of spurs and/or disk herniations. Although these limited exposures may allow for “safe” decompressions only, one must question whether these procedures are truly effective.

1. Learning curve for minimally invasive/microendoscopic laminoforaminotomy 

Do we know the true complication rates (on or off the “learning curve”) associated with minimally invasive/endoscopic laminoforaminotomies? Major complications of these procedures as indicated above may result in significant major morbidity and/or mortality. A brief review of 10 articles revealed that 2 studies reported 2% to 8% frequencies of cerebrospinal fluid fistulas, respectively [1], [3]. Furthermore, in a latter study, comparing microendoscopic laminoforaminotomy (25 cases) to open laminoforaminotomy (26 cases), comparable outcomes for both procedures were documented [3]. Nevertheless, as fewer complications are reported in the spinal literature (discoverable in a court of law), more adverse events are appearing in medico-legal case studies (suits). I recently reviewed cases/suits directly related to complications of cervical spine surgery (data obtained from medico-legal journal, Verdict Search, East Islip, NY) over the last 10 years. One of the 78 cases identified concerned a minimally invasive posterior cervical laminoforaminotmy. The suit involved a well-known New York orthopedic surgeon at a major institution who performed a bilateral minimally invasive laminoforaminotomy at the C4-5 level on a fellow physician. Postoperatively, the patient awakened with a complete bilateral deltoid plegia that never resolved; he remains totally disabled. Because of the inherent delay within the medico-legal system, more recently performed minimally invasive suits will surely follow. In addition, malpractice attorneys approach spine surgeons all the time to review cases and/or to testify regarding injuries sustained from spinal procedures. They will soon focus on morbidity associated with minimally invasive procedures in general, and minimally invasive/endoscopic laminoforaminotomies in particular. Our increased awareness of major complications resulting from these procedures should prompt some form of action. How therefore can we address these issues?

2. Raising awareness 

Perhaps it would be sufficient if we simply raised awareness regarding largely unknown (unpublished) and, therefore, unacknowledged risks and complications of minimally invasive/endoscopic laminoforaminotomy. Certainly, minimally invasive surgical procedures, in all fields, are part of an ongoing “vogue.” Yet informal discussions with colleagues reveal an initial interest followed by a progressive disillusionment with these procedures; many are reverting back to open operations. The literature documents high success rates for the classic open laminoforaminotomy (up to 92.8%), whereas morbidity remains low [2], [4], [5]. We, as physicians, do not want to harm patients, colleagues, or, ultimately, ourselves and should therefore encourage each other to perform the “best,” “safest,” and most effective procedures, even if we lose some patients to “minimally invasive surgeons.” Furthermore, we should be more vocal regarding problems raised by minimally invasive surgeons, as we increasingly address their complications. Posterior cervical excision of spur/disks should not be about the size of the incision, but rather about the safety and efficacy of the operation being performed. We all need to address (present, publish) the complications of minimally invasive surgery in general and minimally invasive/endoscopic laminoforaminotomy in particular to make it clear when minimally invasive is not only minimally effective, but also potentially “maximally” harmful.