Cerebrospinal fluid (CSF) leakage due to inadvertent durotomy during anterior cervical discectomy and fusion (ACDF) has been thought to be a relatively rare complication, with rates in the literature ranging from 0.5-1%. However, ACDF is a high volume procedure at most institutions that perform spine surgery, so this complication will be encountered at least a handful of times each year at most busy spine centers. Given that the entire literature on this topic consists of case reports and one case series of 13 patients, Dr. Syre and his colleagues from the University of Pennsylvania reviewed their cases of CSF leaks during ACDF. Over an 11 year period, three surgeons performed 1,223 ACDFs and noted 13 CSF leaks during the primary operation (1% rate). Patients with ossification of the posterior longitudinal ligament (OPLL) were excluded. All patients underwent indirect repair during the index operation with a combination of a patch (Gelfoam, Duragen, Surgicel or muscle) and a sealant (fibrin glue or Duraseal). Primary repair was successful in 9 of the 13 patients, with 8 having no post-operative symptoms and 1 suffering a headache that resolved after 2 days of being positioned with the head of bed elevated to at least 30 degrees. The remaining 4 patients had signs and symptoms of persistent CSF leak (some in a delayed fashion) and had lumbar drains placed. This intervention was successful in only one of these patients. Two patients were found to have hydrocephalus and had placement of VP shunts, and one patient had placement of an LP shunt. Permanent CSF diversion resulted in the resolution of symptoms in these three patients. Based on their findings and a literature review, the authors proposed a treatment algorithm that begins with indirect repair at the time of discovery followed by 24 hours with elevation of the head of bed. If there are persistent signs or symptoms of CSF leak, a lumbar drain is placed for 3 days, followed by re-operation and further efforts at repair if CSF drainage fails. For patients with persistent leakage despite re-operation and a lumbar drain, the authors recommend consideration of indwelling CSF diversion, especially in cases of hydrocephalus.
This article is an important case series that provides some very practical guidance for a complication that is likely underreported and understudied. Given that most high volume spine centers will have to deal with CSF leaks following ACDF somewhat regularly, it is helpful to have some guidance about how to treat them in a systematic fashion. It is reassuring that the majority of leaks can be repaired with a patch and sealant without any clinical sequelae. More challenging are cases with persistent leakage, and this study suggested that lumbar drainage was not always successful, with only 1 of 4 patients having resolution with a lumbar drain in this series. The use of indwelling CSF diversion for persistent leakage had not been discussed in the literature previously, and this appears to have been a successful salvage for three patients in this series. While this study provides some much needed guidance for CSF leaks in ACDF, it also raises some important questions. What is the best technique of indirect repair, namely what type of patch and sealant is most effective? What is the role of elevation of the head of bed following surgery? Should the bed be raised to 30 degrees, 60 degrees or 90 degrees? If the patient has a persistent headache, should flat bedrest be considered? What are the risk factors for CSF leak other than OPLL and revision surgery? If there is delayed leakage from the wound or drain site, should this be sutured or does closure increase the risk of meningitis? This is a partial list of the unanswered questions that surgeons face when managing CSF leaks after ACDF. Unfortunately, answering these questions would require a large, prospective, multicenter study, and it seems unlikely that such a study will be undertaken. For now, this study and the proposed algorithm provides surgeons with some much-needed guidance about how to deal with this complication.
Please read Dr. Syre’s article on this topic in the July 15 issue. Does it change your approach to managing CSF leaks following ACDF? Let us know by leaving a comment on The Spine Blog.
Adam Pearson, MD, MS
Associate Web Editor