Ординатура / Офтальмология / Английские материалы / Surgical Atlas of Orbital Diseases_Mallajosyula_2009

However, the beginner finds it a little difficult with these approaches. Lynch incision is simpler, and a better procedure for the beginner.If the lesion is

Decision Making 283

large, Lynch incision is my choice (Figures 19.33A to 19.34B).

Lesions of inferior peripheral space, can be approached either through the skin or conjunctiva (Figures 19.35A and B).

Subciliary is more popular of the skin approaches. It still leaves a scar, which is mostly cosmetically

acceptable. However, trans-conjunctival approaches are without a visible scar (Figures 19.36A to 19.38B). Swinging lower eyelid approach causes a scar which is hidden in the crow's feet.

Swinging lower eye lid approach is one of my favorite procedures for large lesions in peripheral surgical space, for optic nerve decompression in thyroid associated orbitopathy, and orbital floor fractures. The advantages include an excellent exposure of field of surgery, possibility of 3-wall decompression and very minimal scar (Figures 19.39A to 19.43B).

Thyroid associated orbitopathy: In India, I find the clinical presentation of thyroid orbitopathy less aggressive than in western reports. This is the same observation of almost all my colleagues in India. However, I came across many Indians at Vancouver whose presentation of thyroid associated orbitopathy

was as severe as in the Caucasians. The weather conditions or the life style may be the reason for this difference and requires a systematic evaluation.

In thyroid orbitopathy, steroids are indicated when the patient has inflammatory symptoms or diplopia. Optic nerve compression is another indication, before surgical decompression is performed. Radiotherapy with linear accelerators in non-diabetics patients is an option when the inflammatory signs and symptoms are controlled with steroids. Surgery is usually in stages, decompression followed next by muscle surgery for squint/diplopia, and then lid surgery for blepharochalasis/lid retraction.

REFERENCES

1.Kaur A, Agrawal A : "Orbital tuberculosis - an interesting case report", Int Ophthalmol. 2005;26(3):107-9.

2.Shome D, Honavar SG, Vemuganti GK, Joseph J. "Orbital tuberculosis manifesting with enophthalmos and causing a diagnostic dilemma" Ophthal Plast Reconstr Surg. 2006; 22(3):219-21.

3.Aversa do Souto A, Fonseca AL, Gadelha M, Donangelo I, Chimelli L, Domingues FS, "Optic pathways tuberculoma mimicking glioma: case report" Surg Neurol. 2003; 60(4):349-53.

4.Aggarwal D, Suri A, Mahapatra AK, "Orbital tuberculosis with abscess" J Neuroophthalmol. 2002;22(3): 208-10.

5.Mavrikakis I, Rootman J.: "Diverse clinical presentations of orbital sarcoid", Am J Ophthalmol. 2007;144(5): 769-77.

6.Biswas J, Krishnakumar S, Raghavendran R, Mahesh L: Lid swelling and diplopia as presenting features of orbital sarcoid"Indian J Ophthalmol. 2000;48(3):231-3.

7.Segal EI, Tang RA, Lee AG, Roberts DL, Campbell GA: "Orbital apex lesion as the presenting manifestation of sarcoidosis"J Neuroophthalmol.2000;20(3):156-8.

8.Ahmad SM, Esmaeli B. "Metastatic tumors of the orbit and ocular adnexal" Curr Opin Ophthalmol. 2007;18(5): 405-13.

9.Sivagnanavel V, Riordan-Eva P, Jarosz J, Portmann B, Buxton-Thomas M; "Bilateral orbital metastases from a neuroendocrine tumor" J Neuroophthalmol. 2004;24(3):240-2.

10.Bakri SJ, Krohel GB, Peters GB, Farber MG: " Spermatic cord leiomyosarcoma metastatic to the orbit" Am J Ophthalmol. 2003;136(1):213-5.

11.McCulley TJ, Yip CC, Bullock JD, Warwar RE, Hood DL: "Cervical carcinoma metastatic to the orbit", Ophthal Plast Reconstr Surg. 2002;18(5):385-7.

12.Mohadjer Y, Wilson MW, Fuller CE, Haik BG: "Primary pelvic telangiectatic osteosarcoma metastatic to both orbits", Ophthal Plast Reconstr Surg. 2004;20(1):77-9.

13.Heerema A, Sudilovsky D: "Mucinous adenocarcinoma of the ovary metastatic to the eye: report of a case with diagnosis by fine needle aspiration biopsy", Acta Cytol. 2001;45(5):789-93.

14.Saikia B, Dey P, Saikia UN, Das A : "Fine needle aspiration cytology of metastatic scalp nodules", Acta Cytol. 2001;45(4):537-41.

General Principles

Before undertaking any surgery in the orbit, a thorough knowledge of the normal eyelid and orbital anatomy is essential. In addition we always evaluate every case starting with a thorough history, meticulous examination, imaging and laboratory investigations. This helps us to arrive at a differential diagnosis. As a general rule, an excisional biopsy is indicated for well circumscribed lesions or those which are benign, while an incisional biopsy is performed for a lesion which is suggestive of malignancy or inflammation.

Thorough understanding of CT and MRI is a must and we must emphasize that familiarity with surgical approaches is essential. One should observe and assist orbital surgeries before one embarks into this independently.

One should also understand the instrumentation needed for this surgery. When using electric saws one needs to ensure safety of the patient's eyeball as well as of the surgeon and the team. Protective glasses should be worn along with face masks to prevent inadvertent spillage of blood and bone fragments. Use of retractors is required to provide adequate exposure. One also needs to be careful not to exert pressure on the globe when using the retractors. Wright's and malleable ribbon retractors are used not only to expose the tissues but also to protect the surrounding tissues. Proper illumination and adequate magnification is essential to visualize the orbital structures.1

The key to safe surgery is good surgical exposure. The surgical incision should be of adequate length. This can be supplemented by traction sutures at

appropriate locations. While cosmesis is desirable, safe and adequate surgical access is the aim. Patience is required when dissecting lesions in the orbit. Gentle blunt dissection is performed using a Freer elevator or lens spatulas to separate the orbital mass from the surrounding tissues. Repositioning of the retractors is essential as the dissection proceeds. In order to perform dissection, the blunt tipped Westcott tenotomy scissors is used. The little finger is a useful instrument to palpate the lesion and perform blunt dissection. Gentle counter traction is needed when dissecting an orbital mass. A cryoprobe can be used to hold the mass and pull it gently while dissection is going on.2

Adequate hemostasis needs to be ensured during orbital surgery. Hypotensive anesthesia is advantageous. However the anesthetist should bring back the blood pressure to normal following surgery, to ensure adequate intraoperative hemostasis. Bipolar cautery should be used in the orbit. When the source of bleed cannot be identified, simple packing with gauze should be performed. Indirect pressure over the closed lids is also useful. Bone wax or gel foam soaked in thrombin can also be used to stem bleeding during orbital surgery.

For an accurate pathological diagnosis, it is necessary to obtain a sample of adequate size, representing the lesion and undamaged by cautery or surgical instrumentation. Routine samples are usually sent in formalin. If a fresh sample needs to be sent or frozen section analysis is required, it is best to inform the pathologist beforehand. The requisition form sent to the pathologist should have detailed clinical findings.

Approaches

Many approaches can be used to gain access to the orbit.3 The various types of incisions are demonstrated in Figure 20.1.

The approaches can be

1.Anterior orbitotomy

a.Approach to the superior orbit

—Benedict incision4

—Upper lid crease incision

—Byron Smith lid split incision5

b.Approach to the inferior orbit

—Mc Cord swinging lower lid incision6

—Subciliary incision

c.Approach to the medial orbit

—Lynch incision

—Gull wing incision

—Transcaruncular incision

2.Lateral orbitotomy

3.Transnasal endoscopic approach

4.Transantral or Calwell–Luc approach

5.Transfrontal orbitotomy.

Anterior Orbitotomy

This approach is useful for anterior orbital lesions, for the drainage of hematomas and abscesses and incision biopsy of posteriorly placed orbital lesions.

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For superior lesions a transcutaneous approach through the upper lid skin crease leaves a less visible scar. However approach thorough the lower lid skin can leave an unsightly scar. The Byron Smith lid split incision which can be used to access large superomedial lesions is not very popular.

A Lynch incision can be used to approach the medial subperiosteal space. A transcaruncular approach is also useful and may be combined with a lateral orbitotomy.

For inferior orbital lesions a lower eyelid transconjunctival approach is the least disfiguring.

Swinging Lower Lid Flap

The first step is to make a mark on the skin horizontally at the lateral canthus. A bridle suture is placed through the inferior rectus muscle and then a mosquito artery forceps is applied to the lateral canthus along the skin mark to provide hemostasis when the incision is made. The skin is then incised with a Bard parker knife or a Colorado needle. After cutting the lateral canthus, inferior cantholysis is performed. Two 4/0 silk traction sutures are passed through the lower lid margin through the grey line of the lower lid. The traction sutures are secured to provide exposure. A conjunctival incision is then made at the inferior border of the tarsus or slightly lower starting laterally and then extending it medially. The plane between the orbicularis muscle

290 Surgical Atlas of Orbital Diseases

and the orbital septum is dissected to the inferior orbital margin. Further traction sutures can be placed through the conjunctiva and inferior retractors to improve visualization. A Desmarre's retractor can be used to give traction and expose the tissues. The periosteum or septum is then opened. With the help of retractors the lesion is exposed and blunt dissection performed to separate the lesion and perform a biopsy. Adequate hemostasis is ensured. The edges of the periosteum are sutured with 6.0 vicryl interrupted sutures. The conjunctiva is closed with interrupted 6/0 vicryl sutures and the lateral canthotomy is repaired by using 6/0 prolene sutures to secure the tarsus to the lateral orbital periosteum. Closure is performed in 2 layers with 6/0 vicryl for the soft tissues and 6/0 prolene for the skin. Antibiotic ointment is instilled and a pressure dressing is applied. The steps of this technique have been demonstrated in Figures 20.2A to Q.

Lateral Orbitotomy

This is a useful technique for lesions in the intraconal space and lesions lateral to the optic nerve. In addition this is useful for large lesions anywhere as this can be combined with other approaches to allow the globe to be moved laterally for increasing surgical exposure. The Berke-Reese incision disturbs the lateral canthus and leaves a less satisfactory scar.7 The modified Stallard Wright approach is a good approach. We are presently using a lid crease approach which gives aesthetically pleasing results.

Stallard-Wright Lateral Orbitotomy8

The first step is to pass 4/0 silk sutures below the insertions of the lateral and superior rectus muscles and form a loop. This is tied to get a hold on the muscle and for identifying the muscle as surgery progresses to avoid any inadvertent damage to the muscles. An incision is made on the skin. The incision starts from just below the lateral aspect of the brow and ends in a rhytid over the anterior zygomatic arch. The skin incision is made with a no. 11 BardParker blade. Under stretch and lifting the tissues, the subcutaneous tissues are dissected down to the periosteum using a radiofrequency monopolar probe. As this dissection proceeds, one must ensure that adequate hemostasis is achieved by using a bipolar cautery. Multiple 4/0 silk traction sutures are placed

to gain exposure. The periosteum is exposed over the whole lateral orbital margin. The periosteum is cut with a monopolar probe about 4 mm behind the orbital rim starting superiorly and ending inferiorly just above the zygomatic arch. Relaxing incisions need to be given to the periosteum. The periosteum is then reflected. The periorbita is also lifted away from the orbital bone upto the anterior one third of the orbit. This has to be performed with care to avoid any breach. The zygomaticotemporal and zygomaticofacial vessels may bleed and may need to be cauterized. The temporalis muscle also needs to be separated laterally and reflected. This muscle is very vascular and adequate hemostasis needs to be ensured. Incision lines are made on the bone about 3 mm above the frontozygomatic suture superiorly and just above the zygomatic arch inferiorly. A Desmarre's retractor is placed to pull the skin and subcutaneous tissue laterally and a lid guard is placed inside the orbit to protect the contents of the orbit. Using an oscillating saw, cuts are made along the incision lines on the bone. Irrigation is performed as the saw is being used. Drill holes may be made on both sides adjacent to the bone cut. Once the cuts have been made, the bone fragment is held with a bone rongeur and moved back and forth until it fractures posteriorly. It is then removed and wrapped in wet saline gauze. The bone can be further nibbled with a bone punch or removed with a burr for further exposure. Hemostasis is essential especially in the region of the temporal fossa. Bone wax may be used to cover any bleeding points in the bone. A T shaped incision is made in the periorbita. This is done with a no 15 Bard Parker blade or a blunt tipped Westcott tenotomy scissors. The incision is then extended circumferentially. A nick is made posteriorly and the periorbita at the cut edges is grasped and gently spread apart to extend the cut posteriorly. Dissection of the orbital mass is performed by blunt dissection. Location of the orbital mass can be confirmed by gentle palpation. Wrights retractors and malleable retractors are used to gently retract the globe and keep the orbital fat away from the area of dissection. Hemostasis is achieved by bipolar forceps. The pupil is checked at regular intervals.9 A cryoprobe can be used to aid delivery of the lesion. If it is an encapsulated lesion, dissection is performed close to the capsule using a Freer elevator. Once the orbital

surgery has been completed, the periorbita can be closed with 6/0 interrupted vicryl sutures. The bone fragment may be replaced and either a wiring through the holes is performed or the cut edges are stuck with cyanoacrylate glue. The periosteum is then closed with 6/0 vicryl sutures. The subcutaneous tissues are apposed with 6/0 vicryl sutures and the skin is closed with 6/0 prolene continuous sutures. Intravenous steroids are preferably given at the end of the procedure. A suction drain may or may not be placed. A pressure dressing is placed after applying antibiotic ointment. The steps of this technique have been demonstrated in Figures 20.3A to S.

Transcarcuncular Approach

This approach through the conjunction for medial orbital lesions is technically difficult but can give better cosmesis than a skin approach. This can be combined with a lateral orbitotomy for greater exposure.

Transnasal Endoscopic Approach and Transantral Approach

This is best performed by or with the assistance of an ENT surgeon and is especially useful for biopsy of lesions near the orbital apex or arising from the sinuses. This is also a useful approach to remove any bone fragments that may be impinging on the optic nerve following an orbital fracture. This is useful for inferior lesions especially those arising predominantly from the maxillary or ethmoidal sinuses for performing a biopsy of these lesions.10

Transfrontal Orbitotomy11-13

This approach is performed to access lesions at the orbital apex. A team approach including a neurosurgeon is needed. There are potential complications in this procedure especially ptosis and extraocular muscle palsy.

A bicoronal flap is created. The frontal bone flap is hinged laterally, still attached to the temporalis muscle and pericranium. This provides good exposure of the medial, superior and lateral orbital apex. If the lesion is confined to the orbit, an extradural approach is undertaken. For orbital lesions extending into the cranium, an intradural approach is needed. The orbital roof is removed, keeping the periorbita intact. The frontal nerve is an important landmark, which runs

Orbitotomies 291

anteroposteriorly over the levator muscle. Entry into the orbit is made medially avoiding the area of the superior orbital fissure. The orbital roof is reconstructed by using an alloplastic material or using the inner table of the frontal bone flap.

Complications

This is a major surgery and there can be complications.14

1.Vascular

a.Bleeding

b.CRVO, BRVO

c.Vitreous hemorrhage

d.Short posterior ciliary artery occlusion

2.Neural/Muscular

a.Corneal anesthesia

b.Internal ophthalmoplegia

c.Extraocular muscle paresis

d.Lateral rectus adhesion

e.Ptosis

f.Optic neuropathy

g.CSF leak

h.hypoesthesia

Postoperative Management

The patient is advised bed rest with the head elevated and advised not to strain to prevent increase in the venous pressure. Steroids and anti-inflammatory medication is prescribed. Systemic antibiotics may be prescribed. The vision, pupil, ocular motility and fundus is assessed.

CASE ILLUSTRATIONS

Case 1

(Swinging lower lid incision of McCord)

A 7-year-old girl presented with complaints of a palpable mass below right eye, gradually increasing in size over 3 months (Figure 20.2A). Clinically a firm to hard mass was palpable in the anterior inferior orbit (arrow indicates the inferomedial orbital mass) (Figure 20.2B). The mass was immobile and non-tender. The mass was causing superior displacement of the globe. Anterior segment and fundus examination were normal except for indentation effect of the mass on the globe, seen inferiorly. There was no limitation of ocular movements.

Figure 20.2A: A 7-year-old girl presented with a mass below the right eye (arrow) with history of gradual increase in size over 3 months

Figure 20.2C: 4/0 silk sutures are passed through the lower lid margin, one near the lateral canthus and one centrally

Figure 20.2D: Mark is made on the skin horizontally at the lateral canthus and a lid speculum is placed. An artery forceps is used to crush the tissues along the mark