- August 2008 - Volume 31 · Issue 8:
Dural tears are not uncommon complications of lumbar spine surgery and have been successfully managed using several techniques, including primary repair, closed subarachnoid drainage, tissue grafting, fibrin-adhesive sealant, and bed rest.1-10 When dural tears are recognized early and treated appropriately, most patients do not experience long-term sequelae.1,3 If an incidental durotomy is not appreciated intraoperatively, the majority of symptomatic patients with a cerebrospinal fluid (CSF) leak typically experience headache and/or photophobia as soon as they assume an upright posture in the postoperative period.4,11-12
There have been numerous reports in the literature describing CSF leaks resulting from dural tears; however, most of these reports documented headache as a symptom of incidental durotomy occurring <72 hours postoperatively. This case report documents 2 instances of dural tears following lumbar spine surgery that were asymptomatic for ≥1 week after the initial procedure. These cases demonstrate that spine surgeons should be aware that patients may not exhibit symptoms of CSF leak, particularly headache, until several days after lumbar spine surgery, and their occurrence may indicate a delayed spinal fluid leakage that requires additional surgery and direct repair of the dura to correct the problem and alleviate the symptoms.
A 53-year-old man presented to the spine surgeon in June 1990 reporting a several-month history of C6 nerve root distribution paresthesias and dysesthesias and bilateral leg pain, resulting in difficulty ambulating. Following a comprehensive urologic evaluation that failed to determine a cause for the patient’s urinary hesitancy, coupled with physical examination findings revealing ataxia and sustained right ankle clonus, magnetic resonance imaging was performed, revealing cervical and lumbar spinal stenosis. The following month, a posterior cervical laminoplasty from C3-C7, in combination with a posterior lumbar laminectomy and foraminotomy from L2-L5, was performed.
The procedure was performed under general anesthesia, and postoperatively the patient was found to have normal motor function in his upper and lower extremities bilaterally. The patient successfully recovered from his myelopathy and was relieved of his neurogenic claudication. Five weeks after his initial operation, the patient experienced unrelenting headaches and returned to the surgeon’s office for further evaluation. Magnetic resonance imaging of the lumbar spine showed evidence of a spinal fluid leak. A clinical suspicion of spinal fluid leakage was confirmed upon exploration of the operative site. A pseudomeningocele that developed secondary to a dural tear from a bony spicule was found at the surgical site. A sharp bone edge from previous laminectomy was identified and directly correspondeded to the length and position of a 3-mm dural tear. The bone spicule was removed and the dural tear was successfully repaired with 6-0 prolene monofilament suture in an interrupted fashion. The patient recovered uneventfully following 24 hours of bed rest, and did not experience further episodes of headaches.
A 51-year-old man with a 1-month history of severe left leg pain underwent lumbar discectomy on June 15, 2005, for spinal stenosis and disk herniation at the L4-L5 level. Postoperatively, the patient’s strength and sensation were intact in all 4 extremities, and he experienced almost total relief of his left leg pain and was discharged home the following day.
CT scan of the lumbar spine, transverse view, demonstrating a bone spicule protruding from the superior articular facet of L5 on the right side.
Five days following discharge, the patient experienced orthostatic headaches and returned to the surgeon’s office for evaluation. Magnetic resonance imaging was performed, which revealed a postoperative subfascial epidural fluid collection. A computed tomography myelogram was then performed, which did not demonstrate distention of the dural sac, but was suggestive of a CSF leak. The headache recurred while standing, following 2 days of bed rest. Due to strong suspicion of a spinal fluid leak, the surgical site was explored. Upon examination of the right superior facet process, an osseous spike measuring approximately 3.0×0.5 mm was noted immediately adjacent to the dural sac (Figure). The spicule of bone had eroded through the dural and arachanoid membranes causing spinal fluid leakage. The bone spike was removed and the durotomy was repaired with 6-0 prolene monofilament suture in an interrupted fashion. The patient experienced complete resolution of headaches after repair of the dural tear and 24 hours of bed rest, and had an uneventful postoperative course. At 18-month follow-up, the patient continued to report relief of leg pain and has had no recurrence of headaches.
While the occurrence of a dural tear as a complication of lumbar spine surgery is not uncommon, the late onset of symptoms makes these 2 cases unique. Reports of pseudomeningocele development presenting as localized back pain or radiculopathy several weeks or even months after surgery exist,13-16 but we could find only 1 report detailing a durotomy that was unrecognized at the time of surgery presenting as sudden onset headache 2 weeks following the operation.14 Cammisa et al4 reported 3 patients with persistent headaches diagnosed in the postoperative period as secondary to incidental durotomy at an average interval of 20.8 days subsequent to surgery. It is unclear from this report, however, when the symptoms began relative to surgery, or how long conservative management was attempted before election to reoperate.
The 2 patients described in this case report did not have symptoms of spinal fluid leakage following surgery, and no intraoperative dural tear was noted, suggesting these cases may have been secondary to late postoperative durotomy. The symptoms occurred several days later in 1 case and 5 weeks later in the other case, and in both cases a bone spicule was found to have eroded through the dura. Both patients were tall men with sclerotic bone. They required wide exposures of the dura, their bone was brittle and tended to form spikes, and their spinal fluid column was long. While standing, the resultant intrathecal spinal fluid pressure likely expanded the dura up against a spicule of bone at the edge of the decompression, resulting in erosion of the dura and spinal fluid leakage.
Although we routinely inspect the dura for spinal fluid leakage and the margins of the spinal canal decompression for bone spicules prior to wound closure, we found neither at the time of initial surgery. While we cannot prove the absence of durotomy at the time of closure, we suspect that the durotomy occurred later, when the patients became symptomatic. The incidence of durotomy has been noted to be increased in patients undergoing revision spine surgery secondary to adhesions and scarring of the dura.9 As this was the first spine operation for both cases reported, we feel strongly that residual bone spikes are responsible for puncturing the dural sac postoperatively.
Diagnosis of a dural tear postoperatively usually requires some combination of clinical history, physical examination, and imaging studies. The cases reported here had no visible subcutaneous fluid collection or wound drainage on physical examination; however, they did have a history of severe postural headaches suspicious for CSF leakage, which was confirmed with imaging studies. We feel the weight of suspicion for CSF leakage should lie with information obtained from taking a detailed history.
While no specific algorithm for management of postoperative dural tears exists at our institution, we opt for a trial of 48 hours bed rest prior to a repeat trip to the operating room if symptoms arise within a short period of time from the initial surgery. For patients in which >1 month has elapsed since the initial operation, or in the case of development of a pseudomeningocele or fistula, we opt for immediate surgical repair. Once a postoperative durotomy has been repaired, we recommend an additional 24-hour period of trial bed rest prior to assuming an upright posture. In both cases presented here, there was no further complaint of headache beyond the 24-hour period of bed rest.
The important lesson in both cases is to listen to the patient and recognize the significance of the new onset of an orthostatic headache. This may be the only symptom of a late spinal fluid leak.
- Eismont FJ, Wiesel SW, Rothman RH. Treatment of dural tears associated with spinal surgery. J Bone Joint Surg Am. 1981; 63(7):1132-1136.
- Kitchel SH, Eismont FJ, Green BA. Closed subarachnoid drainage for management of cerebrospinal fluid leakage after an operation on the spine. J Bone Joint Surg Am. 1989; 71(7):984-987.
- Wang JC, Bohlman HH, Riew KD. Dural tears secondary to operations on the lumbar spine. Management and results after a two-year minimum follow-up of eighty-eight patients. J Bone Joint Surg Am. 1998; 80(12):1728-1732.
- Cammisa FP Jr, Girardi FP, Sangani PK, Parvataneni HK, Cadag S, Sandhu HS. Incidental durotomy in spine surgery. Spine. 2000; 25(20):2663-2667.
- Barrios C, Ahmed M, Arrotegui JI, Bjornsson A. Clinical factors predicting outcome after surgery for herniated lumbar disc: an epidemiological multivariate analysis. J Spinal Disord. 1990; 3(3):205-209.
- Black P. Cerebrospinal fluid leaks following spinal surgery: use of fat grafts for prevention and repair. Technical note. J Neurosurg. 2002; 96(2 suppl):250-252.
- Jones AA, Stambough JL, Balderston RA, Rothman RH, Booth RE Jr. Long-term results of lumbar spine surgery complicated by unintended incidental durotomy. Spine. 1989; 14(4):443-446.
- Shaikh S, Chung F, Imarengiaye C, Yung D, Bernstein M. Pain, nausea, vomiting, and ocular complications delay discharge following ambulatory microdiscectomy. Can J Anaesth. 2003; 50(5):514-518.
- Tafazal SI, Sell PJ. Incidental durotomy in lumbar spine surgery: incidence and management. Eur Spine J. 2005; 14(3):287-290.
- Cain JE Jr, Dryer RF, Barton BR. Evaluation of dural closure techniques. Suture methods, fibrin adhesive sealant, and cyanoacrylate polymer. Spine. 1988; 13(7):720-725.
- Hodges SD, Humphreys SC, Eck JC, Covington LA. Management of incidental durotomy without mandatory bed rest. A retrospective review of 20 cases. Spine. 1999; 24(19):2062-2064.
- Khan MH, Rihn J, Steele G, et al. Postoperative management protocol for incidental dural tears during degenerative lumbar spine surgery: a review of 3,183 consecutive degenerative lumbar cases. Spine. 2006; 31(22):2609-2613.
- Aldrete JA, Ghaly R. Postlaminectomy pseudomeningocele. An unsuspected cause of low back pain. Reg Anesth. 1995; 20(1):75-79.
- Hadani M, Findler G, Knoler N, Tadmor R, Sahar A, Shacked I. Entrapped lumbar nerve root in pseudomeningocele after laminectomy: report of three cases. Neurosurgery. 1986; 19(3):405-407.
- O’Connor D, Maskery N, Griffiths WE. Pseudomeningocele nerve root entrapment after lumbar discectomy. Spine. 1998; 23(13):1501-1502.
- Rinaldi I, Hodges TO. Iatrogenic lumbar meningocele: report of three cases. J Neurol Neurosurg Psychiatry. 1970; 33(4):484-492.
Drs Brookfield, Randolph, Eismont, and Brown are from the Department of Orthopedics, University of Miami, Jackson Memorial Hospital, Miami, Florida.
Drs Brookfield, Randolph, Eismont, and Brown have no relevant financial relationships to disclose.
Correspondence should be addressed to: Kathleen Brookfield, MD, PhD, MPH, Department of Orthopedics, University of Miami, Jackson Memorial Hospital, PO Box 016960, (R-2), Miami, FL 33136.