Lumbar TDR Revision Strategies

Abstract

At the University of Maryland St Joseph Medical Center (UMSJMC), we have become a tertiary referral center for revision anterior retroperitoneal and transperitoneal approaches. To date we have performed over 500 repeat anterior approaches and over 100 revisions for failed lumbar arthroplasty referred from Elsewhere General.

With current lumbar TDR designs, the lumbar spine is approached anteriorly for numerous reasons. These include (1) minimal morbidity allowing for short recovery times; (2) unobstructed visualization of the disc space, allowing for total discectomy and accurate implant sizing; (3) the absence of the need to enter or retract posterior neural structures in the spinal canal; and (4) the familiarity of territory for many spine and vascular surgeons. Accordingly, the approach-related risks are both predictable and relatively low. In contrast, revision approaches to the anterior lumbar spine are about six times higher risk for major bleeding or thromboembolic complications due to adhesion formation, which prevent accurate identification of the great vessels. The anterior lumbar spine therefore remains a relatively facile approach as an index procedure but is fraught with potential complications in any revision situation. In our experience, many failures of lumbar disc replacement could have been avoided as they can be traced to surgeon-specific factors (as opposed to patient-specific factors) such as incomplete discectomy, improper device insertion, or inappropriate indications.

Our approach for revisions is to over-prepare – assume you will have suboptimal visualization between fascial planes. This means we place ureteral stents to palpate the ureters. In addition, in the event of inadvertent entering of the ureter, the stent facilitates suture repair by acting as a conduit in the early postoperative period. Occasionally for high-risk cases, we also prophylactically cannulate the femoral vessels. This allows faster intraoperative endovascular passage of balloons intraoperatively to assist hemostasis. In addition we can pass covered vascular stents up from the femoral vein and artery in an endovascular technique in the event of friable vessels with limited exposure in a deep retroperitoneal revision.