Iatrogenic fracture of the superomedial orbital rim during frontal trephine irrigation.
Frontal sinus trephination (FST) has numerous applications in the treatment of acute and chronic sinus disease. This procedure involves making an incision at the medial aspect of the supraorbital rim and then drilling the sinus's anterior table. Placement of a frontal trephine allows for irrigation of the frontal recess in order to evacuate the frontal sinus in a minimally invasive manner. Orbital injury is a rare complication of FST. We present a case of previously unreported orbital compartment syndrome secondary to iatrogenic fracture of the superomedial orbital rim as a complication of frontal trephine irrigation. We also review the literature on the applications of FST and its associated complications, and we discuss orbital compartment syndrome as a complication of sinus surgery.
Several surgical approaches to the frontal sinus have been described, including frontal sinusotomy, endoscopic endonasal sinusotomy, and various combined approaches that involve both endoscopic techniques and frontal sinus trephination (FST). In 1750, Runge (1) first described the use of FST in treating complications of acute frontal sinusitis, and its applications have expanded over time.
FST involves making an incision at the medial aspect of the supraorbital rim and then drilling the frontal sinus's anterior table. (2) Because direct endoscopic visualization of the frontal sinus drainage pathway is veiled by the capricious and complex pneumatization pattern of frontoethmoid cells, FST has been used as an adjunct to endoscopic sinus surgery. It is useful for endonasally locating the ostium and subsequently performing outflow tract enlargement. (3) FST also enables frontal recess irrigation in order to evacuate the frontal sinus in a minimally invasive and hence minimally traumatic manner. (3) Significant advantages of a combined approach include reduced morbidity, shorter recovery, and a greater likelihood of preserving sinus mucosa and natural drainage outflow tracts. (2)
Minitrephination of the frontal sinus is associated with a complication rate of 6.4%. (4) The most common is infection, which accounts for approximately one-third of all complications. (4) Others include postoperative stenosis, a poor aesthetic outcome and, in very rare cases, intracranial or orbital penetration. Since FST carries a greater risk of complication than does endoscopic sinus surgery alone, it is reserved for cases in which adequate endoscopic access to and exposure of the frontal recess are limited. (5)
We present a very unusual complication of FST: orbital compartment syndrome. This syndrome occurred secondary to an iatrogenic microfracture of the superomedial orbital rim. We describe its management with emergency lateral canthotomy. To the best of our knowledge, this type of complication has not been previously reported in the literature in association with FST.
A 67-year-old woman presented with a long-standing history of severe nasal polyposis. Her main symptoms were chronic severe headaches and nasal congestion. Computed tomography (CT) showed a complete opacification of the frontal, ethmoid, and sphenoid sinuses bilaterally; these imaging characteristics were suggestive of allergic fungal disease (figure, A). The patient was taken to the operating room for endoscopic sinus surgery.
Intraoperatively, nasal polyps were cleared from the right nasal cavity, and a complete ethmoidectomy was performed on the right. A right frontal trephine was placed through the anterior frontal sinus table, and fluorescein irrigation was used to wash out fungal mucin from the right frontal sinus. Following this, a left frontal trephine was placed through the anterior frontal sinus table and irrigated with fluoresceinized saline to wash out the viscous fungal mucin. Irrigation was noted to be more difficult on the left, but large amounts of fungus were still expressed into the nose.
Before the left ethmoidectomy was started, bulging and tension of the skin of the left upper eyelid developed. Chemosis was seen, and the eye was clearly proptotic. No bleeding was noted in the nose, and the ethmoid sinuses had not yet been dissected on that side, so an arterial bleed was discounted as the cause. No reason for raised intraorbital pressure was seen. An urgent lateral canthotomy was performed, which rapidly reduced the tension on the eyelid, and the eye regained its normal contour. The procedure was then aborted.
Postoperatively in the recovery room, the patient reported no decrease in visual acuity or diplopia. An immediate CT was obtained, and it showed a new fracture line in the superomedial orbital rim (figure, B). The fracture was clearly located at a site distant from the site of the trephine placement. Therefore, the fracture was presumably caused by pressure from the trephine irrigation rather than by the placement of the trephine itself.
The ophthalmology service was consulted to assist in ongoing management, which consisted of regular vision checks and natural tear irrigation. On postoperative day 5, a lateral canthopexy was performed to resuspend the lower lid, and the patient was sent home.
The optimal trephine diameter and placement location have been evaluated and debated in the literature. A maximum diameter of 5 mm has been recommended to minimize soft-tissue prolapse and cosmetic deformity. (5)
Previously, the optimal location of trephine placement was considered to be 10 mm from the midline at the level of the medial aspect of the eyebrow. (6) However, a subsequent evaluation of the safety of FST with standard frontal trephination instruments of 7 mm in length revealed no significant difference between sinus depth at various distances (5, 10, and 15 mm) from the midline. (3) Nevertheless, because of the variability in the location of the intersinus septum among individuals, the risk of crossed trephination is higher when the trephine is placed closer to the midline. (3)
Once the trephine has been placed, aspiration with a saline-filled syringe should be performed to ensure correct placement. The presence of a clear aspirate may indicate intracranial penetration, which is an indication that the trephine should be removed. (6) In nearly 15% of patients with nonhypoplastic frontal sinuses, the depth at a particular point from the midline may not be adequate, which increases the risk of inadvertent entry through the sinus's posterior table. (3) Since women have smaller frontal sinuses than do men, women represent the majority of these patients. (3)
Regardless of the patient's sex, a detailed preoperative review of CT images should be performed to ensure that the frontal sinus is not too shallow for the trephination instrument. Sagittal reconstructions of CT images best evaluate the anterorposterior dimension of the frontal sinus, and they should be used in conjunction with axial and coronal views. (2,3)
Other complications of FST include (1) supratrochlear and supraorbital nerve and vessel injury with resultant hypoesthesia of the ipsilateral forehead and scalp, (2) poor wound healing, and (3) possibly hypertrophic scarring. (2) The risk of associated complications increases with a more lateral incision, so the supraorbital nerve notch should be palpated as a means of preventing this. (3) Superomedial orbital injury can lead to hemorrhage and vision loss because the ophthalmic artery courses through this area and branches into the anterior and posterior ethmoid arteries.
Seiberling et al described two complications that occurred when a trephine was placed into a frontal mucocele that had eroded the orbital rim and lamina papyracea. (6) After trephine flushing, one patient developed increased intraocular pressure and temporary proptosis, while the other developed brief asystole secondary to activation of the ocular carotid reflex. In view of these findings, if there is evidence of erosion of the floor or posterior wall secondary to frontal disease, fluorescein flushing must be performed judiciously. If resistance is encountered or if the fluorescein is not visualized intranasally, it should be stopped immediately.
An acute rise in intraorbital pressure is a hallmark of orbital compartment syndrome. The onset of this syndrome represents a surgical emergency that can develop in seconds to minutes. Its most common cause is orbital hemorrhage. (4) The orbit contains extraocular muscles, fat, the lacrimal gland and lacrimal apparatus, neurovascular structures, the globe, and surrounding fascia. Anteriorly, the orbit is bounded by the eyelids, orbital septum, and on three of its sides by four firm, bony walls. Its volume of approximately 30 ml is fixed in nature. (7) Forward movement of the globe and fat prolapse are compensatory mechanisms that occur during acute increases in intraorbital pressure. However, forward movement is limited by the medial and lateral canthal tendons that attach the eyelids to the bony orbital rim. Consequently, a continuous rise in intraorbital pressure begets a decrease in perfusion. (7)
Signs of orbital compartment syndrome can be categorized as external, ophthalmoscopic, and neuro-opthalmic. (4)
* External signs include chemosis, external ophthalmoplegia, increased resistance to retropulsion, orbital ecchymosis, proptosis, and subconjunctival hemorrhage. (4)
* Ophthalmoscopic signs include central retinal artery pulsation or occlusion, elevated intraocular pressure, op tic disc swelling, retinal edema, and venous congestion. (4)
* Neuro-opthalmic signs include afferent pupillary defect, dyschromatopsia, and in some cases changes in visual acuity. (6)
Intraoperatively, external signs are most useful for detecting raised intraocular pressure. Two of the earliest signs are acute proptosis and a loss of orbital compliance. (4) Early recognition of injury to the orbit and immediate intervention are required to prevent serious, long-term ophthalmologic complications.
Since orbital compartment syndrome is a surgical emergency, an ophthalmologist should be consulted immediately. Initially, cantholysis should be performed, including both a lateral canthotomy and canthal tendon disinsertion. In lateral canthotomy, the lateral canthal tendon is cut along its length; in canthal tendon disinsertion, the lateral canthal tendons inferior crus is disinserted from the tubercle of Whitnall on the bony orbit. (8) In the management of orbital compartment syndrome secondary to orbital hemorrhage, cantholysis has been shown to lead to a significantly greater reduction in intraocular pressure than that which can be accomplished by either lateral canthotomy or canthal tendon disinsertion alone. (8)
Immediately following this procedure, the patients clinical status should be reevaluated. If there is no improvement within a few minutes, the surgeon should consider proceeding with disinsertion of the superior canthal tendon, followed by transconjunctival or transcutaneous division of the orbital septum from its attachment to the orbital rim. (9) If these measures fail, extensive osseous decompression may be required.
The prognosis for patients with orbital compartment syndrome depends on how much time has elapsed between onset and treatment, the presence of globe tenting (which may predict visual compromise), the patient's age, and the underlying etiology. (9) Findings on postoperative orbital CT and magnetic resonance imaging correlate well with the clinically localized site of injury and can assist in elucidating the etiology of complications related to endoscopic sinus surgery. (9)
(1.) Runge LH. De Morbis Praecipuis Sinuum Ossis Frontis et Maxillae Superioris et Quibusdam Mandibulae Inferioris. Rinteln, Germany: Enax; 1750.
(2.) Sillers M, Lindman JP. Operative trephination for non-acute frontal sinus disease. Operative Techniques in Otolaryngology-Head and Neck Surgery 2004;15(1):67-70.
(3.) Lee AS, Schaitkin BM, Gillman GS. Evaluating the safety of frontal sinus trephination. Laryngoscope 2010;120(3):639-42.
(4.) Dunya IM, Salman SD, Shore JW. Ophthalmic complications of endoscopic ethmoid surgery and their management. Am J Otolaryngol 1996;17(5):322-31.
(5.) Bent JP III, Spears RA, Kuhn FA, Stewart SM. Combined endoscopic intranasal and external frontal sinusotomy. Am J Rhinol 1997;11(5):349-54.
(6.) Seiberling K, Jardeleza C, Wormald PJ. Minitrephination of the frontal sinus: Indications and uses in today's era of sinus surgery. Am J Rhinol Allergy 2009;23(2):229-31.
(7.) Lima V, Burt B, Leibovitch I, et al. Orbital compartment syndrome: The ophthalmic surgical emergency. Surv Ophthalmol 2009;54(4):441-9.
(8.) Yung CW, Moorthy RS, Lindley D, et al. Efficacy of lateral canthotomy and cantholysis in orbital hemorrhage. Ophthal Plast Reconstr Surg 1994;10(2):137-41.
(9.) Bhatti MT, Schmalfuss IM, Mancuso AA. Orbital complications of functional endoscopic sinus surgery: MR and CT findings. Clin Radiol 2005;60(8):894-904.
Douglas Angel, MD; Rebecca Zener, MD; Brian W. Rotenberg, MD, MPH, FRCSC
From ENT Consultants, St. John's, Newfoundland (Dr. Angel); and the Department of Diagnostic Radiology and Nuclear Imaging (Dr. Zener) and the Department of Otolaryngology-Head and Neck Surgery (Dr. Rotenberg), Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ont. The case described in this article occurred at the University of Western Ontario.
Corresponding author: Dr. Brian W. Rotenberg, Department of Otolaryngology-Head and Neck Surgery, St. Josephs Health Care London, 268 Grosvenor St., London, ON N6A 4V2, Canada. Email: brian. firstname.lastname@example.org
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|Title Annotation:||ORIGINAL ARTICLE|
|Author:||Angel, Douglas; Zener, Rebecca; Rotenberg, Brian W.|
|Publication:||Ear, Nose and Throat Journal|
|Article Type:||Clinical report|
|Date:||Dec 1, 2014|
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