6 Jul

Eyelid tumours in dogs and cats – part 3

James Oliver, Renata Stavinohova

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Eyelid tumours in dogs and cats – part 3

ABSTRACT

This review – part three of a series – provides a clinical and surgical approach to the most frequently diagnosed and most important eyelid neoplasms in dogs and cats.

Part one discussed the anatomy and examination of the eyelids in dogs and cats. The remainder of part one, and part two were focused on common canine and feline eyelid tumours respectively. Here, a detailed description of basic and more advanced surgical procedures to address eyelid tumours, in dogs and cats, is provided.

Treatment should be tailored to the individual tumour type following systemic assessment of the patient.

Factors to consider prior to any therapy include malignancy, rate of growth, localisation, local invasiveness, presence of metastases, degree of corneoconjunctival irritation, and response to previous and current therapy (Maggs, 2013).

Eyelid tumours are mostly treated surgically, often with adjunctive therapy such as cryotherapy, brachytherapy, carbon dioxide laser therapy, photodynamic therapy, radiation therapy, chemotherapy or immune therapy.

Adjunctive therapy should always be considered if complete resection of the tumour is not possible to obtain (Maggs, 2013).

Surgical preparation for adnexal procedures

Head position of the patient should be supported using, for example, a vacuum-aided bead-filled cushion (Figures 1a and 1b).

Figures 1a. A vacuum-aided bead‑filled cushion.
Figures 1a. A vacuum-aided bead‑filled cushion.
Figures 1b. A vacuum-aided bead‑filled cushion.
Figures 1b. A vacuum-aided bead‑filled cushion.

Head loupes – headband system (Figure 2) or glass-mounted (2× to 6× magnification) – with an inbuilt source of illumination are advised.

Figure 2. Head-mounted loupes.
Figure 2. Head-mounted loupes.

A povidone-iodine aqueous solution (10ml of 1:50) diluted in sterile sodium chloride 0.9% should be used to flush the cornea and conjunctival fornices. Then sterile cellulose spears (Figure 3) soaked in the 1:50 povidone‑iodine solution are used to remove any mucus or debris. A minimum contact time of five minutes is required (Maggs, 2018).

Figure 3. Sterile cellulose spears.
Figure 3. Sterile cellulose spears.

After that, 10ml of sterile saline solution is used to flush out the antiseptic solution.

At the end, swabs soaked in a 1:10 povidone‑iodine solution are used to prepare the outer eyelid skin.

Surgical instruments

Surgical instruments should be kept in either plastic or steel surgical sterilisation trays (Figure 4).

Figre 4. Basic eyelid surgical kit in a plastic sterilisation tray.
Figure 4. Basic eyelid surgical kit in a plastic sterilisation tray.

A basic eyelid surgical kit (Figures 5a to 5d) should include the following instruments:

  • eyelid speculum (eg, Castroviejo, Barraquer),
  • Bennett’s cilia forceps
  • chalazion Desmarres forceps
  • Brown-Adson thumb tissue forceps
  • fine rat tooth forceps
  • Bard-Parker handle
  • Beaver scalpel handle
  • Derf needle holder
  • Castroviejo (non-locking) needle holder
  • straight and curved haemostats
  • Steven’s tenotomy scissors
  • Calipers (eg, Jameson and Castroviejo)
  • Jaeger lid plate
  • Nettleship’s dilator
  • straight Metzenbaum scissors (Figure 6a)
  • curette (Figure 6b)
Figures 5a to 5c. Basic eyelid surgical kit. From left: eyelid speculum (Castroviejo, Barraquer), Bennett’s cilia forceps with rounded, smooth, blunt tips to avoid damage to the lid margins, chalazion Desmarres forceps, Brown-Adson thumb tissue forceps, fine rat tooth forceps, Bard-Parker handle, Beaver scalpel handle, Derf needle holder, Castroviejo (non-locking) needle holder, straight and curved haemostats, Steven’s tenotomy scissors, Calipers (Jameson and Castroviejo), Jaeger lid plate and Nettleship’s dilator. Figure 5d. Detail of the atraumatic rounded tip of the Bennett’s cilia forceps

Disposables consist of biopsy punch (Figure 6c); adhesive and non-adhesive paper drapes; cellulose tipped spears or absorbent sticks (Figure 7); No.11 or No.15 Bard-Parker scalpel blades; and Beaver blades, for instance No.65 (Figure 8).

Figure 6. Click/hover over each image for caption.
Figure 7. Absorbent sticks.
Figure 7. Absorbent sticks.
Figure 8 (left). Bard-Parker scalpel blades No.11 (8a) and No.15 (8b), and Beaver blade No.65 (8c).
Figure 8 (left). Bard-Parker scalpel blades No.11 (8a) and No.15 (8b), and Beaver blade No.65 (8c).

Surgical principles of eyelid surgery

Eyelid skin requires gentle handling, technique and fine instruments.

Surgical procedures depend on the site of the eyelid mass and the eyelid margin involvement. The upper lid is larger and more mobile than the lower lid, and it plays an important role in covering the cornea during blinking. Therefore, it is important for upper eyelid defects to be accurately repaired to maintain eyelid anatomy and function (Manning, 2002).

Resection of the lesion adjacent to, or involving, the medial canthus is more difficult as the skin is very tightly adhered to periorbital tissue (Stades and Van der Woerdt, 2013; Figure 9).

Figure 9. Clinical presentation of the meibomian gland adenoma involving the medial lower eyelid; lower eyelid punctum was visualised by flushing the upper eyelid punctum and it was repositioned medially.
Figure 9. Clinical presentation of the meibomian gland adenoma involving the medial lower eyelid; lower eyelid punctum was visualised by flushing the upper eyelid punctum and it was repositioned medially.

Regarding the lacrimal puncta, the lower one should be preserved if possible to prevent epiphora (tear overflow) (Stades and Van der Woerdt, 2013; Figure 10).

Figure 10. Clinical presentation of the meibomian gland adenoma involving the medial lower eyelid; lower eyelid punctum was visualised by flushing the upper eyelid punctum and it was repositioned medially.
Figure 10. Clinical presentation of the meibomian gland adenoma involving the medial lower eyelid; lower eyelid punctum was visualised by flushing the upper eyelid punctum and it was repositioned medially.

The lid margin is the most important area during blepharoplasty, and precise apposition of eyelid margins is required to avoid corneal and conjunctival damage (Figure 11).

Figure 11. Appearance of the upper eyelid two weeks after a mass removal via a four‑sided eyelid resection.
Figure 11. Appearance of the upper eyelid two weeks after a mass removal via a four‑sided eyelid resection.

Maintaining/restoring the conjunctival fornix will prevent disruption of tear collection and movement. Blunt dissection and tissue undermining should be minimal to avoid tissue damage, swelling and decreased blood supply to the lid (Gelatt, 2014).

Lid flaps and grafts have a tendency to contract postoperatively; therefore, they should be planned appropriately larger than the true size of the eyelid defect (Gelatt, 2014).

For precise surgical planning, a marker pen to outline the skin incision and calipers are used. The resection should be at least one meibomian gland orifice or 1mm beyond the margins of the tumour (Manning, 2002; Stades and Van der Woerdt, 2013).

In feline squamous cell carcinoma, complete excision with margins up to 5mm is recommended (Murphy, 2013). The average length of the palpebral fissure when stretched by calipers is approximately 33mm in most medium to large-breed dogs (Stades and Van der Woerdt, 2013). In canine, about a quarter of the eyelid length can be safely removed by a wedge excision, shaped either as V or four-sided defect (Figures 12a to 12d), to be able to achieve primary closure (Gelatt and Blogg, 1969; Gwin, 1980; Hamilton et al, 1999). When more than 25% of eyelid length is removed, blepharoplasty should be performed.

Figures 12a to 12c. Four-sided eyelid resection. Figure 12d. Appearance of the right eye four weeks post-surgery.

Furthermore, when 60% to 90% of the eyelid is involved, more extensive blepharoplasty procedures are required.

In cats where eyelids are more tightly apposed, blepharoplasty should be considered even for small defects (Gould and Carter, 2016).

Commonly used suture material for adnexal surgery is either absorbable (such as polyglactin) or non-absorbable (such as nylon), sized 6‑0 with a curved reverse cutting needle (Mitchell and Oliver, 2015). The authors prefer absorbable suture material as suture removal may require sedation, especially in cats.

The resultant defect is closed in two layers, rather than one, to avoid a V notch at the eyelid margin. Two-layer suturing consisting of a tarsal plate suture (6/0, absorbable suture material) and a figure of eight suture (6/0, absorbable suture material) dictates not only good apposition, but also wound strength (Figures 13a and 13b).

Figure 13a. The tarsal plate suture is buried within eyelid tissue following a far-near-across-near‑far suture pattern.
Figure 13a. The tarsal plate suture is buried within eyelid tissue following a far-near-across-near‑far suture pattern.
Figure 13b. The figure of eight suture: the needle is first placed in the skin away from the eyelid margin and directed obliquely to the other side of the defect to exit the eyelid margin through meibomian gland orifices, equidistant from the incision. The needle is then directed to the other side of the defect to enter the meibomian gland orifice equidistant from the incision. It is then directed to the other side of the wound, equidistant from the incision. After closure, the eyelid margin should be aligned precisely. The ends of the suture material can be caught in the knots of the adjacent simple, interrupted suture.
Figure 13b. The figure of eight suture: the needle is first placed in the skin away from the eyelid margin and directed obliquely to the other side of the defect to exit the eyelid margin through meibomian gland orifices, equidistant from the incision. The needle is then directed to the other side of the defect to enter the meibomian gland orifice equidistant from the incision. It is then directed to the other side of the wound, equidistant from the incision. After closure, the eyelid margin should be aligned precisely. The ends of the suture material can be caught in the knots of the adjacent simple, interrupted suture.

Tarsal plate suturing will also reduce postoperative haemorrhage from wounded conjunctiva. The tarsal plate suture is followed by a simple, continuous suture, with the knots buried, to appose the tarsoconjunctival layer (6/0, absorbable suture material).

Very thin eyelids may be sutured with a figure of eight suture only. The eyelid muscle/skin is apposed with a simple, interrupted suture (6/0 non‑absorbable/absorbable suture material). The knot of a figure of eight suture should be directed away from the cornea.

Postoperative treatment consists of topical antibiotics (7 to 10 days) and systemic NSAIDs (3 to 5 days). Systemic antibiotics may be indicated for extensive procedures (Stades and Van der Woerdt, 2013) or for patients that are difficult to treat topically. An Elizabethan collar is advised to prevent the patient from rubbing and possibly interrupting the surgical site (Stades and Van der Woerdt, 2013).

Basic surgery techniques

Basic eyelid surgery techniques in cats and dogs (Stades and Van der Woerdt, 2013) include:

  • V/four-sided eyelid resection and primary closure of an eyelid defect after neoplasm excision from the upper or lower eyelid:
    • A full–thickness excision of the mass with appropriate margins is performed.
    • Free eyelid margin incisions are performed by a scalpel blade No.11 or No.15, or Beaver blade No.65.
    • The incision is expanded as a V shape or four-sided shape on the outer eyelid skin. The V‑shaped excision is performed by oblique cutting of meibomian glands, whereas a four‑sided or house-shaped excision is created by rectangular cutting of the eyelids (Figures 9 and 12a to 12d).
    • The tumour is then excised “en bloc” using Steven’s tenotomy scissors.
    • The resultant defect is closed in two layers (a tarsal plate suture and a figure of eight suture) with absorbable 6/0 suture material, as previously described.
  • Blepharoplasty (Stades and Van der Woerdt, 2013): Blepharoplasty should be performed if primary closure of an eyelid margin defect is not possible by direct suturing.
  • “House inverted-triangle” blepharoplasty (Figures 14 and 15):
    • A one-step procedure, indicated for small upper and lower eyelid lesions.
    • A full or partial excision of the mass with appropriate margins is performed.
    • Removal of masses of 25% to 50% of the eyelid length; especially when the stretched lid fissure reaches less than 33mm after closing the defect after eyelid mass removal.
    • The resultant defect is closed in two layers (a tarsal plate suture and a figure of eight suture) with absorbable 6/0 suture material, as previously described.
    • A full-thickness incision at the lateral canthus, in the direction of the eyelid that is being lengthened, is performed.
    • A triangle of skin (a relaxation triangle) is excised at the lateral end of the skin (the direction of the triangle is reversed to the location of the eyelid mass), which allows the skin to be slid medially.
    • The resultant defect is closed in two layers with absorbable 6/0 suture material.
    • No scar formation will occur within the new lid margin at the tumour removal site, and trichiasis will be restricted to the lateral margin (Figure 16).
Figure 14. Click/hover over each image for caption.
Figures 15a to 15h. A “house inverted‑triangle” blepharoplasty. Clinical case. A caliper is used to measure the length of the palpebral fissure and size of the tumour.
Figure 16. Appearance of the left eye three weeks after “house inverted‑triangle” blepharoplasty. Trichiasis was restricted to the lateral part of the upper eyelid with no further complications.
Figure 16. Appearance of the left eye three weeks after “house inverted‑triangle” blepharoplasty. Trichiasis was restricted to the lateral part of the upper eyelid with no further complications.
  • Sliding skin – outer lid margin flap (Landolt; Figure 17):
    • A one-step procedure, indicated for larger upper and lower eyelid tumours.
    • A full or partial excision of the mass with appropriate margins is performed.
    • After lid splitting, a large flap of 10mm to 15mm in depth is dissected, followed by excision of a relaxation triangle at the end of the wound (the direction of the triangle is reversed to the location of the eyelid mass), which allows the skin to be slid medially.
    • The sliding skin-outer lid margin flap is closed in one layer by a simple, interrupted suture (6/0 non-absorbable/absorbable suture material).
    • The lid margin will undergo scar formation.
Figures 17a and 17b. Sliding lateral canthoplasty (Landolt).
  • H-figure sliding graft (H-plasty; Figures 18a to 18c):
    • A one-step procedure, indicated for larger upper and lower eyelid neoplasm more than half of the eyelid margin.
    • A full or partial thickness excision of the mass with appropriate margins is performed.
    • An adjacent partial thickness advancement flap is created. For a full thickness defect, adjacent conjunctiva is advanced first into the defect and sutured with non-absorbable 6/0 (continuous pattern with buried suture).
    • Two vertical slightly divergent skin incisions are continued at the base of the wound and they should be 1.5 to 2 times the length of the defect’s height.
    • Two equal-sized relaxation triangles of skins are excised at the base of both skin excisions to enable shifting of the graft into the surgical wound.
    • The skin flap is undermined and advanced into the defect; the leading edge of the skin graft should be slightly beyond (0.5mm to 1mm) the adjacent eyelid margin.
    • The resultant defect is closed in two layers. The deeper tarsoconjunctival layer can be apposed by simple, continuous or interrupted absorbable sutures with the knots buried. The remaining muscle-skin lid is apposed with a simple, interrupted suture starting at the angled area (6/0 non‑absorbable/absorbable suture material).
    • The potential disadvantages are trichiasis and a scarred new eyelid margin. Since the lower eyelid is less mobile, the incidence of trichiasis and keratitis after this procedure is lower.
Figure 18. An H-plasty.

Advanced blepharoplasties

For even larger eyelid margin excisions, other advanced blepharoplasties are indicated. These include a Z-plasty procedure (Figures 19a to 19c), mucocutaneous subdermal plexus (lip to lid; Figures 20a to 20d), Mustardé technique or Roberts and Bistner technique (Figures 21a and 21b; Roberts and Bistner, 1968; Munger and Gourley, 1981; Pavletic et al, 1982; Esson, 2001; Hagard, 2005; Hunt, 2006; Whittaker et al, 2010; Stades and Van der Woerdt, 2013). All of them apart from the Mustardé technique are one‑step techniques.

Figure 19. A Z-plasty can be used for tumours involving lateral canthal defects.
Figure 20a. Lip to lid transposition graft. The upper lip and the lip commissure is used to repair the large eyelid defect after full‑thickness excision of the neoplasm involving the upper eyelid and lateral canthus. A marker pen is used to outline the incisions. Figure 20b. A full‑thickness dissection of the lip is performed; this oral mucosa junction will play a role as the new eyelid margin. The dissection is followed by separation of the skin and subdermal plexus from the deeper structures to allow the flap to be rotated to the eyelid defect. Releasing skin incisions are made ventral to the lower eyelid to connect the two areas. The incised skin between the eyelid defect and the lip pedicle is excised, and the flap is rotated into the defect. Figure 20c. The pedicle is sutured in place in two layers, started at the eyelid/flap margins by a modified tarsal plate suture and figure of eight suture. Figure 20d. Detail of the blepharoplasty.
Figure 21. The Roberts and Bistner technique.

The resultant defect is closed in one/two layers. The deeper tarsoconjunctival layer can be apposed by simple, continuous, absorbable sutures with the knots buried. The remaining muscle/skin lid is apposed with a simple, interrupted suture (6/0 non-absorbable/absorbable suture material).

The posterior aspects of the H–figure sliding graft, Z-plasty procedures may be overgrown by conjunctival cells spontaneously or can be lined, for instance, by adjacent mucosa.

The first step of the Mustardé technique involves sharp dissection of the neoplasm of the recipient region of the upper eyelid followed by construction of a full‑thickness donor graft of the lower eyelid. The graft is then transposed to the upper eyelid defect and sutured in place.

The second step includes sectioning of the connection of the graft to the lower eyelid two weeks after the first procedure.

Closure of the lower eyelid defect can be achieved with various techniques – for instance, an advancement sliding skin graft (H plasty) or lip to lid.

The Mustardé technique should preferably be performed by an experienced ophthalmologist as complications are common.

Invasive neoplasms may require enucleation or orbital exenteration. If after enucleation the defect cannot be closed in a primary fashion then a caudal auricular axial pattern or an axial pattern flap can be performed (Stiles et al, 2003; Jacobi et al, 2008).

All of these advanced blepharoplasties are complex and referral to an ophthalmic surgeon should be considered.

Indications, pros and cons for eyelid procedures are detailed in Table 1.

Table 1. Eyelid techniques: indication, pros and cons
Eyelid procedure Indication Advantages Disadvantages
V/four-sided wedge excision Both eyelids, tumour smaller than 25 per cent One-step procedure, primary closure of an eyelid defect N/A
House inverted-triangle Both eyelids One-step procedure
No scarred new lid margin at the tumour removal site
Trichiasis of the lateral eyelid margin
Sliding skin – outer lid margin flap Both eyelids One-step procedure Scarred new lid margin at the tumour removal site
H-figure sliding graft Both eyelids One-step procedure Trichiasis (commonly occur on the upper eyelid)
Scarred new lid margin at the tumour removal site
Z-plasty Both eyelids One-step procedure Trichiasis
Scarred new lid margin at the tumour removal site
Lip to lid Lower eyelid, lateral canthus/lateral upper eyelid One-step procedure
Maintaining smooth new eyelid-like margins
Trichiasis
Wound dehiscence
Mustardé technique Upper lid Maintaining smooth eyelid margins
The resulting eyelid margins are functionally and anatomically normal
Two-step procedure
During the first stage, the visual axis is partially obscured
Micropalpebral fissure
Trichiasis
Wound dehiscence
Roberts and Bistner technique Both eyelids One-step procedure Trichiasis
  • Figures 13a and 13b, 14a and 14b, 17a and 17b, 18a to 18c, 19a to c and 21a and b are modified drawings from Stades and Van der Woerdt (2013).