Management of Postoperative Cerebrospinal Fluid Leaks

Chapter 60 Management of Postoperative Cerebrospinal Fluid Leaks



image Videos corresponding to this chapter are available online at www.expertconsult.com.


Egress of cerebrospinal fluid (CSF) from the subarachnoid space into surgical wounds may result in leakage of CSF from the wound, the ear canal (if the tympanic membrane is not intact), or the nose (via the eustachian tube). CSF follows the path of least resistance. Any procedure that encounters the subarachnoid space can be complicated by a postoperative CSF leak. These leaks result from failure to obtain watertight dural closure or from an inadequate seal of dural defects. CSF leaks are a concern because the defect provides a potential portal of entry for infection to seed the leptomeninges. Meningitis in this setting is accompanied by significant morbidity and mortality. CSF leaks should be corrected promptly to avoid more serious complications. This chapter describes the various techniques for treating postoperative CSF leaks.



PRESSURE DRESSING


For cases in which an abdominal fat graft has been used during closure to plug dural defects, a pressure dressing can be applied to control CSF leaks. The pressure dressing works by pushing the fat back into the dural defect, sealing off the subarachnoid space. In cases in which fat has been used, most leaks stop with a pressure dressing. If a subcutaneous CSF collection (pseudomeningocele) is present, it may be aspirated before the placement of the pressure dressing. If performed, aspiration should be done with sterile technique. Cases involving incisional wound leaks may be treated by a simple suture overclosure of the leaking portion of the incision and a pressure dressing.



Technique


The dressing is applied in similar manner to the initial postoperative dressing. First, a vertical gathering tie is placed in the temporal fossa. Dressing sponges (4 × 4) are folded in half and placed directly over the fat graft and in the postauricular sulcus to support the auricle (Fig. 60-1A). Next, fluffed Kerlix is placed over the 4 × 4 sponges and the auricle (Fig. 60-1B). A tight wrap of roller gauze is applied (Fig. 60-1C). The direction of the wrap should be from the ear toward the occiput, which ensures that the auricle is not damaged by anterior folding. Also, the vertical tie must be as lateral as possible in the temporal fossa to avoid a pressure point on the forehead. Pressure necrosis of forehead skin can develop easily if attention is not given to this point.



The last layer of this dressing is a 3-inch elastic bandage, which provides the final compression (Fig. 60-1D). The elastic bandage should be wrapped firmly, but patient comfort must be accommodated. Usually, the last several turns can be altered to adjust the exact amount of compression. Ideally, a pressure dressing should be left in place for 4 or 5 days, which allows time for healing of the CSF leak site to occur. A minimum of 48 hours without leakage must pass before the dressing is removed.


In addition to the pressure dressing, other conservative actions should be undertaken. These measures all are directed at decreasing CSF pressure. Straining (Valsalva maneuver) is strictly avoided, and the patient is kept at bed rest with the head elevated 45 degrees. Limited activity, such as bathroom privileges or brief periods of sitting up in a chair, is at the surgeon’s discretion. Stool softeners and cough suppressants can be used. Acetazolamide (Diamox) may be given to decrease CSF production.



LUMBAR DRAIN


The next step in CSF leak treatment is a lumbar subarachnoid spinal fluid drain. By removing CSF from the system at a site away from the dural defect, CSF pressure is decreased, and healing can occur. Some surgeons routinely place a lumbar drain at the time of surgery to assist with intraoperative CSF removal and decompression in the postoperative period.



Technique


To place the catheter, a lumbar puncture is performed at the L4-L5 level. The patient is placed in either a sitting or a lateral decubitus position. The spinous processes are palpated, and L4-L5 is identified at the level of the iliac crest. The patient is asked to flex the back and bring the knees and chin to the chest. A prepared catheter kit contains all the necessary supplies for preparing, draping, and anesthetizing the site. A 14 gauge Tuohy needle is introduced in the midline with a slightly superior angle between the spinous processes (Fig. 60-2). The obturator is removed at intervals so that the surgeon can look for a flow of CSF. When a good flow of CSF is established, the epidural catheter is introduced through the needle and threaded into the epidural space. The opened side of the bevel of the needle faces the patient’s left or right side on penetrating the spinous ligaments and arachnoid. Before the catheter is threaded, the bevel is turned to open superiorly, facilitating directing the catheter cephalad. With a flow of CSF established, the needle is withdrawn, and the connector is placed on the end of the catheter so that a connection to intravenous tubing can be made. An empty intravenous fluid bag is attached to the tubing, and all connections are secured with tape (Fig 60-3A).



Several methods of regulating CSF output exist. This regulation is important because, if CSF is removed too rapidly, tension pneumocephalus and brain herniation can occur.13

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Jun 14, 2016 | Posted by in OTOLARYNGOLOGY | Comments Off on Management of Postoperative Cerebrospinal Fluid Leaks

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