John E. McClay, M.D., Octavio Carreno, M.D.,Ashmit Gupta, M.D., and Ayal Willner, M.D.

Treatment of Postcraniotomy

Tension Pneumocephalus

via Endoscopic Closure of

the Nasofrontal Recess

Tension pneumocephalus results when air enteringthe cranial cavity becomes trapped. While pneumo-

cephalus is a common finding in patients who have un-

dergone craniotomy, intracranial air persisting beyondseveral weeks is unusual. Further, intracranial air thatcauses pressure on the brain can lead to neurologic dys-function. Surgical management of this disorder has tra-ditionally required craniotomy. The case of a 14-year-old female with tension pneumocephalus leading totemporary neurologic deficits is presented. This case isunique in that the surgical management was endoscopic.

CASE PRESENTATION

J.P. is a 14-year-old female with a history of a re-

current pilocytic astrocytoma of the skull base andclivus. She had undergone resection of this tumor viacraniotomy six times, the last being approximately sixweeks (in another state) prior to presentation to us. Thepatient had also undergone radiation therapy and had a

ventriculo-peritoneal (VP) shunt placed as part of hermanagement. The last surgical procedure involved ex-

tensive dissection of the medial skull base as well as

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Skull Base Surgery, Volume 8, Number 4, 1998 Department of Otorhinolaryngology, University of Texas-Southwestern Medical Center, Dallas,Texas (J.E.M.), Division of Otolaryngology-Head and Neck Surgery, George Washington University Medical Center, (O.C., A.G.) and LongBeach Memorial Medical Center, Long Beach, California (A.W.). Reprint requests: Dr. John McClay, Department of Otorhinolaryngology, Uni-versity of Texas-Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75235-9035. Copyright © 1998 by Thieme Med-ical Publishers, Inc., 333 Seventh Avenue, New York, NY 10001, USA. Tel.: +1 (212) 760-0888. All rights reserved.

SKULL BASE SURGERY/VOLUME 8, NUMBER 4 1998

cranialization of the frontal sinuses. By the operative re-port and correspondence with the previous surgeon, allmucosa had been stripped from the nasofrontal recessesand they had been packed with betadine-impregnatedgelfoam. Because of her multiple procedures, her cal-varium had to be reconstructed using multiple boneflaps.

The patient's postoperative course from her previ-ous surgery in another state was moderately prolongedbut she was discharged approximately one week aftersurgery and traveled home on an airplane. She devel-oped increasing lethargy and neuromuscular weaknessand was seen at a local hospital. Lateral x-rays of theskull revealed a large amount of intracranial air with ex-tension into the soft tissue over the left temporal areaand the patient was transferred to Children's NationalMedical Center. Transcutaneous needle aspiration of theair and supine bed rest resulted in resolution of the in-tracranial air. However, upon sitting up for severalhours, air re-accumulated. Further radiologic workupshowed a large amount of intracranial extradural air oncomputerized tomographic (CT) imaging with compres-sion of the patient's brain (Figs. 1 and 2). The mostlikely pathway of air into the cranial cavity was felt tobe via the nasofrontal recesses which had been closedwith only gelfoam.

Figure 1. Coronal CT scan showing anterior pneu-mocephalus and bone flap/graft reconstruction.

Figure 2. Axial CT scan showing anterior pneumo-cephalus and bone graft/flap reconstruction.

Due to the risks to the recently placed bone grafts,craniotomy was deferred in favor of an endoscopic ap-proach. After uncinectomy, the anterior ethmoid andfrontal recess air cells were opened until the nasofrontalducts could be visualized from below. Gelfoam wasseen at the entrance to the frontal sinuses (Fig. 3). Acurved suction was introduced into the cranial cavityand the air was easily evacuated. The nasofrontal ductswere packed endoscopically from below with grafts ofmuscle and fascia lata (Fig. 4).

The patient was kept supine for one week and thenallowed to sit up and resume her normal activities. Fol-low-up magnetic resonance imaging (MRI) at 3 and 8months showed complete resolution of the intracranialair. The patient was asymptomatic both then and at 2years following the procedure.

DISCUSSION

Pneumocephalus occurs acutely in every patientundergoing a craniotomy and is usually subdural. In thepostoperative course, the incidence decreases in thefirst, second, and third week to 75%, 60%, and 26%, re-spectively.' Importantly, the natural course of postoper-ative pneumocephalus can help differentiate a patho-logic from a non-pathologic condition.

Tension pneumocephalus is a rare condition inwhich trapped intracranial air causes compression of thebrain resulting in neurological changes. It results whenair is able to enter, but not exit, the cranial cavity. Ten-sion pneumocephalus has been reported followingtrauma, intranasal surgery, and neurosurgical proce-dures.2 A one-way valve usually occurs at the interfacebetween the nose or paranasal sinuses and the skullbase. In this particular case, it is likely that the patient'sVP shunt was also involved in the pathologic process.When she sat upright, the shunt acted as a siphon todrain the cerebrospinal fluid from around the brain andthereby decrease the intracranial pressure. Because the

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EN DOSCOPIC TREATMENT OF PNEUMOCEPHALUS-McCLAY ET AL

MTI

Figure 3 Endoscopic view of the left nasofrontal re-cess via 300 telescope showing gelfoam pledgets (GF),middle turbinate (MT) and patent opening of the frontal re-cess (FR).

nasofrontal recess allowed air to enter the cranial vault,this process continued and led to the accumulation of asignificant amount of intracranial air.

Surgical management of tension pneumocephalushas traditionally been performed through a craniot-omy.3A4 The air is usually extradural and repair focuseson finding and obliterating the intranasal-intracranialconnection. Fascia, fat, muscle, and bone chips withgelfoam, surgicel, thrombin, and fibrin glue have allbeen used in the treatment of this problem.5 Intranasalrepairs of dural defects associated with tension pneumo-cephalus via external ethmoidectomy have been re-ported as well.5

Endoscopic repair of intranasal-intracranial con-nections has occurred both before and after the popular

..:.: ......

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Figure 4. Endoscopic view of the left superior mid-dle meatus showing the fascia lata/muscle plugs (FL) un-der the middle turbinate (MT) lateral nasal wall ([NW),septum (S).

use of endoscopic procedures for sinus disease. Repairwith fat, fascia, free mucosal grafts, turbinate grafts,pedicled septal grafts, and bone combined with gelfilm,gelfoam, and fibrin glue have been reported with goodresults. These techniques of repair have been used tocontrol cerebrospinal fluid leaks.6,7t8

The decision to attempt endoscopic closure of thenasofrontal ducts was made secondary to concernsabout devascularization of the recently grafted calvarialbone and overlying irradiated skin and galea. A factorinfluencing both the infection rate and the degree ofbone graft resorption is the vascularization of bone graftreconstruction. Vascularized bone grafts have a moresuccessful chance of maintaining viability than freebone grafts, which depend upon their incorporation bythe surrounding tissue bed.9 Removing the overlyingscalp from the grafts in this patient could have disruptedthe revascularization process and increased both the riskof infection and the amount of bone lost to resorption.

CONCLUSION

While pneumocephalus is a common and benignpost-craniotomy occurrence, tension pneumocephalusresulting in increased intracranial pressure can have se-rious neurologic consequences. In most cases, it is ex-tradural caused by a one-way valve into the cranial vaultfrom the paranasal sinuses. Traditional surgical man-agement is via craniotomy with careful obliteration ofthe valve, mainly found in the nasofrontal recess area.This case is interesting in that the development of ten-sion pneumocephalus occurred not only secondary tothe patency of the nasofrontal ducts, but the negative in-tracranial pressure generated as the patient sat up andthe VP shunt drained CSF. This is, to our knowledge,the first report of an endoscopic closure of the na-sofrontal ducts as the treatment of this entity. Such anon-traditional approach is warranted when significantrisks are associated with craniotomy and only after itcan be ascertained that prior complete removal of thefrontal sinus mucosa has been performed.

REFERENCES

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3. Sekerci Z, Akalam N, Kilic C, Demirkazik M. Pneumocephalus atthe cerebellopontine angle secondary to chronic otitis media.Clin Neurol Neurosurg 1990;92(2):155-157

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