Autogenous Fascia Augmentation of a Partially Extirpated Muscle With a

Subperiosteal Medial Orbitotomy Approach Abdulaziz H. Awad, MD," Grace S. Shin, M D , b Arthur L. Rosenbaum, M D , b and Robert L. Goldberg, MD b

Introduction: Endoscopic sinus surgery can result in serious extraocular muscle dysfunction. The medial rectus muscle is more frequently affected than other extraocular muscles. Methods: A transconjunctival subperiosteal medial orbitotomywas successful in retrieving a partially extirpated medial rectus muscle after endoscopic sinus surgery. Besults:A previous attempt to localize this muscle by conventional surgery with extensive exploration was unsuccessful. A Hummelsheim procedure was also abandoned after a rupture of the nasal aspect of the inferior rectus muscle occurred. Conclusion: The approach we describe allowed adequate visualization of the posterior orbital content, as well as adequate space for suture placement. (J AAPOS 1997;1:138-42)

D iplopia is a well-recognized rare complication of intranasal sinus surgery and is related to direct or indirect injury to the extraocular muscle, its

nerve, or vascular supply. 1-5 During the past decade, endoscopic sinus surgery has become an increasingly popular treatment for chronic sinus disease. Medial rectus muscle injury has been reported because of inadvertent orbital entry of the endo-scopic surgical instrument though the lamina papyracea and periorbita.1- 5 Inferior rectus and superior oblique dysfunction has also been reported. 6,7 Diplopia can be transient when it is related to edema or minor trauma to the periorbital region. 4 However, constant diplopia with marked limitation of duction may occur as a result of direct extraocular muscle trauma.

We report a patient with a partially extirpated medial rectus muscle after endoscopic sinus surgery. The patient had intractable diplopia. Improved ocular alignment was ob-tained by recovery of the proximal portion of the medial rectus muscle with use of a transconjunctival subperiosteal medial orbitotomy approach combined with temporalis fascia augmenta- tion to restore integrity between the muscle and sclera.

Front King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia," and Jules Stein Eye Institute, University of California Los Angeles School of Medicine? Reprint requests: Arthur L. Rosenbaum, MD, Chief, Division of Pediatric Ophthalmol- ogy, Vice ChaiTvuan, Department of Ophthalmology, Jules Stein Eye Institute/UCLA, 100 Stein Plaza, Los Angeles, CA 90095-7001. Copyright © 1997 by the American Association for Pediatric Ophthalmology and Sts'abismus. 1091-8531/9755.00 + 0 75/1/81209

CASE R E P O R T

A 60-year-old otherwise healthy man underwent endoscopic sinus surgery through the right and left nostrils for chronic sinusitis. On the first postoperative day the patient had horizontal diplopia, exotropia, and inability to adduct the left globe. Computed tomographic scanning showed that a large segment of the medial rectus muscle was missing. The proximal part of the medial rectus had retracted into the orbit close to the optic nerve. Ten days after the sinus surgery, the patient underwent extensive surgical exploration through a limbal approach in an attempt to retrieve the proximal segment of the medial rectus muscle. Because this attempt was unsuccessful after 3 hours of exploration, the muscle was considered irretrievable. At that time, the surgeon decided to proceed with a nasal partial transposition of the superior and inferior rectus muscles. Because the inferior rectus muscle was split, the nasal aspect of the muscle ruptured. The ruptured segment was sutured together, and the transposition procedure was abandoned.

The distal portion of the transected medial rectus muscle was still attached at the insertion. The unattached end of this distal portion was sutured to the periosteum of the nasal orbital wall to act as a mechanical leash.

After surgery the patient demonstrated persistent horizontal and vertical diplopia. He was able to fuse in a small area in the left gaze with a chin-up position. A trial of prism glasses was unsuccessful.

When first examined by us, the patient demonstrated 20 degrees of right face turn and 5-degree chin-up position to fuse with his eyes in moderate left and slightly downward gaze. His uncorrected visual acuity was 20/20 in each eye at distance.

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Awad et aL 139 Journal of AAPOS Volume 1 Number 3 September 1997

FIG. 1. Clinical appearance of patient on his initial evaluation.

FIG. 2. Dynamic magnetic resonance image with surface coil. Arrow denotes proximal segment of left medial rectus width with eye in abduction.

FIB. 3. Dynamic magnetic resonance image with surface coil showing increase in width of proximal segment of medial rectus muscle (arrow) as eye moves from abduction (see Figure 2) to adduction.

Prism cover testing revealed 14 prism diopters of exotropia and 12 prism diopters of right hypertropia in the primary position at distance and near. The exotropia increased markedly in progressive right gaze and was slightly reduced in left gaze. The right hypertropia measured 4 prism diopters less in left gaze than in right gaze. Ductions revealed inability to adduct the left globe past the vertical midline. In

addition, there was mild limitation of abduction and moderate limitation of upward rotation of the left globe. Clinically, the patient demonstrated a moderate floating adduction saccadic movement of the left eye (Figure 1).

Each pupil was 4.0 mm in size and reacted well to light and accommodation. Slit-lamp examination results were unremarkable. Dilated funduscopic examination showed a

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FIR. 5. Temporalis fascia in place as itwas sutured.

"<-,~

FIR. 4. Medial rectus (proximal segment) as itwas isolated from fracture site and freed of scar tissue, being sutured with a 6-0 Novafil suture.

central 0.2 disc diameter cup in the right eye and a 0.3 disc diameter cup in the left eye. Intraocular pressure measured 24.0 mm Hg in each eye, by applanation tonometry. Cycloplegic retinoscopy results were OD +0.25 +0.50 × 180 degrees; OS +0.25 +0.25 × 180 degrees.

Dynamic high-resolution magnetic resonance imaging (MRI), with use of a surface coil, was performed. The test demonstrated that a 20.0 mm segment of the middle portion of the medial rectus muscle was missing. The proximal segment of the muscle showed increased diameter on attempted adduction, indicating that this portion of the muscle was still capable of contracting (Figures 2 and 3). An iris fluorescence angiogram showed marked delay in filling of the radial iris blood vessels in all areas, except the superior quadrant of the left iris.

Surgical approach and postoperative course

Because of the persistent exotropia in the primary position and the profound inability to adduct the left globe past the vertical midline, the patient elected to proceed with further strabismus surgery in an attempt to achieve better alignment. A standard limbal conjunctival peritomy was fashioned. The insertional segment of the remaining medial rectus muscle was isolated, and surrounding scar tissue removed in the area where the muscle had been sutured to the periosteum. Further dissection was continued posteriorly. However, the proximal segment of the medial rectus muscle could not be visualized through this conventional approach.

The decision was made to approach the proximal segment of the medial rectus muscle through an anterior medial

orbitotomy. Access to the medial orbital wall, just behind the lacrimal outflow system, was made through a conjunctival incision at the lateral border of the carunde. Blunt dissection was carried posteriorly along the medial orbital wall through the subperiosteal space to the fracture site by using a periosteal elevator. Two malleable retractors were inserted to separate billowing orbital fat from the medial rectus muscle. The proximal end of the muscle was identified at the fracture site after dissection through a dense layer of scar tissue. This end was then removed from the fracture site.

An autogenous piece of temporalis fascia was then harvested from the patient's scalp. This graft was sutured to the edge of the freed proximal segment of the medial rectus muscle with a nonabsorbable suture (6-0 Novafil; Sherwood-Davis & Geck, St. Louis) (Figure 4). The nonsutured end of the temporalis fascia was then passed through a fenestration in Tenon's capsule toward the globe. This edge of the temporalis fascia was isolated through the previously created limbal conjunctival incision. The temporalis fascia was sutured to the sclera 6.0 mm posterior to the limbus after the length of the temporalis fascia had been fashioned and adjusted to maintain the globe in the apparent primary position (Figure 5). The conjunctival flap was closed.

After surgery, the patient could fuse with a small right face turn and was aligned near the primary position with ability to rotate the left globe about 10 degrees past the midline into the adducted field (Figure 6). He has been observed for more than 11/2 years since the surgery and has /maintained that alignment.

D I S C U S S I O N

A summary of previously reported cases of damaged medial rectus muscles after nonendoscopic and endo-

Journal of AAPOS Volume 1 Number 3 September 1997 Awad et al. 141

FIG. 6. Clinical appearance of patient 1 year after surgery. Note improved alignment in primary position and minimal adduction ability.

TABLE 1. Previous cases of damaged medial rectus muscles after sinus surgery

Author Initial surgery Strabismus surgery

Mark and Kennerdell ~ (1979) Patient 1: Transnasal ethmoidectomy

Patient 2: Nasal polypectomy and CaldwelI-Luc procedure

Flynn et a12 (1979)

Buus et al. 7 (1990)

Eitzen and Elsas 3 (1991)

Patient 1: Nasal polypectomy and anterior ethmoidectomy

Patient 2: Nasal polypectomy and anterior ethmoidectomy

Patient 1: Intranasal ethmoidectomy

Patient 1: Endoscopic ethmoidectomy

Patient 2: Endoscopic ethmoidectomy and polypectomy

Ipsilateral lateral rectus recession 7.00 mm transposition of superior and inferior recti to medial rectus insertion

July 1976, ipsilateral lateral rectus recession 8.00 mm. Medial rectus resection 10.00 mm

September 1976, transposition of superior and inferior recti to medial rectus insertion

Ipsilateral lateral rectus recession 10.00 mm and traction suture to anchor globe in adduction position for 3 weeks

Ipsilateral lateral rectus recession 8.00 mm. Medial rectus resection to 10.00 mm

Transposition of superior and inferior recti to medial rectus insertion

Ipsilateral lateral rectus recession 900 mm. Medial rectus resection 8.00 mm

None (patient had small, well-controlled deviation)

scopic sinus surgery is shown in Table 1 with the corrective extraocular muscle surgery. It is obvious that the majority needed a transposition procedure or a recess- resect procedure to correct the deviation, depending on the severity of the damage to the medial rectus muscle. Our patient had several problems: a large central section of the muscle was extirpated, the distal segment of the muscle was small and nonfunctioning, and a previously attempted vertical rectus muscle transposition had failed. An iris fluorescein angiogram demonstrated that the anterior segment circulation was compromised. These factors seemed to limit the surgical options to a further attempt at vertical rectus muscle transposition with preservation of

the anterior ciliary vessels, or as chosen, a further attempt to retrieve the proximal segment of the medial rectus muscle.

An anterior medial orbitotomy approach provided excellent visualization of this portion of the muscle. Conceivably, recovery of a "lost" completely intact medial rectus muscle would be easier through this approach. In the largest reported series of 25 patients with confirmed lost rectus muscle, the medial rectus was the most common (10 of 25) and had the lowest retrieval rate (1 of 10), necessitating transposition procedures. 8 Recently, a transnasal endoscopic approach to the medial rectus muscle was described by McKeown et al. 9 The procedure

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was described as a cadaver study but not in an actual patient with a lost medial rectus muscle. The innovative approach deserves further study. However, it seems that an endoscopic approach is surgically difficult and provides a very limited field of view and working space, which makes identification and suture placement in the muscle more difficult. Using a medial orbitotomy approach, we were able to achieve adequate exposure to identify the muscle and to place sutures at its borders with ease.

We hope that this surgical approach will provide the surgeon with another option to localize and retrieve a traumatized or lost medial rectus muscle.

References

Mark LE, Kennerdell JS. Medial rectus injury from intranasal surgery. Arch Ophthalmol 1979;97:459-61.

2. FlynnJT, Mitchell KB, Fuller DG, London HB, Cohen HH. Ocular motility complications following intranasal surgery. Arch Ophthalmol 1979;97:453-8.

3. Eitzen JP, Elsas FJ. Strabismus following endoscopic intranasal sinus surgery. J Pediatr Ophthalmol Strabismus 1991 ;28:168-70.

4. Stanldewicz JA. Complications of endoscopic sinus surgery. Otolaryngol Clin North Am 1989;22:749-58.

5. Smith LF, Brindley PC. Indications, evaluation, complications, and results of functional endoscopic sinus surgery in 200 patients. Otolaryngol Head Neck Surg 1993;108:688-96.

6. Rosenbaum AL, Astle WF. Superior oblique and inferior rectus muscle injury following frontal intranasal sinus surgery. J Pediatr Ophthalmol Strabismus 1985;22:194-202.

7. Bnns DR, Tse DT, Farris BK. Ophthalmic complications of sinus surgery. Ophthalmology 1990;97:612-9.

8. Plager DA, Parks MM. Recognition and repair of the "lost" rectus muscle. A report of 25 cases. Ophthalmology 1990;97:131-7.

9. McKeown C, Metson RB, Dunya IM, Shore JW, Joseph MP. Transnasal endoscopic approach m expose the medial rectus from the annulus of Zinn to the penetration of Tenon's capsule. J Pediatr Ophthalmol Strabismus 1996;33:225-9.