Dural tears are a recognized complication in spinal surgery. For routine microdiscectomy, recent trials have found a 4% risk.1 With the increasing complexity of surgery, this rate of risk increases, with revision microdiscectomies having up to a 17.4% chance of dural tear.2 In the majority of cases, the defect can be managed by either primary repair, application of tissue sealants or blood patches, and tissue grafting. However, further intervention is required in a small number of cases (<2%)3 to divert cerbrospinal fluid (CSF) from the tear.

Many surgeons place an extradural gravity drain after surgery, allowing approximately 80 to 100 mL of CSF to drain per shift. Keeping the gravity drain to obviate suction theoretically allows the subfascial CSF pressure to dictate the amount of drainage, without extracting additional CSF from the subdural space. The diversion of CSF decreases the CSF pressure differential between the intradural and extradural space, allowing the dural breach to heal. Drainage of 120 to 360 mL/d for 3 to 5 days has a 90% to 92% success rate in the treatment of a CSF fistula. Such drains can be helpful in decompressing the subfascial space to prevent the buildup of CSF, which is caustic to tissue and may lead to the formation of a fistula.

We advocate the use of a simple easily constructible drain in small CSF leaks. In our experience, current drainage systems are expensive and may not be a regularly ordered and retained item of stock. We have devised an external lumbar drainage system that can be easily constructed at minimal cost using 4 items commonly stocked in any surgical department and have used this without any complications. We advocate its usage for small CSF leaks in which the cost and monitoring of a specific drainage system would outweigh the benefits, as well as in the emergency setting when there is no other drainage system available. A portex epidural catheter connected to a Lectocath, which is then attached to a gravity drainage bag by means of a 3-way stop-clock connector, which is then attached to a gravity drainage bag, forms an effective lumbar drainage system at a total cost of £58.59 in comparison with the Becker drainage system at £667 (Fig. 1).

FIGURE 1:

Lectocath male luer lock, 77p; 3-way stop clock, 32p; a 16-G portex epidural catheter, £7.50; gravity drain, £50.

1. Weinstein JN, Tosteson TD, Lurie JD, et al. Surgical vs nonoperative treatment for lumbar disk herniation. The Spine Patient Outcomes Research Trial (SPORT): A Randomized Trial. JAMA. 2006;296:2441–2450 2. Stolke D, Sollmann W, Seifert V. Intra- and postoperative complications in lumbar disc surgery. Spine. 2000;25:2663–2667 3. 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 (Phila Pa 1976). 2006;22:2609–2613