- Floor is rarely decompressed in isolation: usually combined with medial wall as inferomedial decompression
- Approaches to floor and medial wall similar and are grouped together for discussion
Incisions and approaches
Transcutaneous lower eyelid incision
- Two options after skin incision:
- Skin-muscle flap:
- Orbicularis is traversed below the lid margin (typically leaving 2–3 mm of pretarsal orbicularis inferior to skin incision)
- Septum then followed to orbital rim and opened at arcus marginalis
- Skin flap:
- Faise skin flap below incision to the level of the orbital rim
- Then incise orbicularis and the septum together at rim
- Skin flap approach noted to have higher incidence of ectropion relative to skin-muscle approach, thus latter is preferred (Pospisil, Br J Oral Maxillofac Surg 1984)
- Other transcutaneous options (Bahr, Plast Reconstr Surg 1992; Holtmann, Plast Reconstr Surg 1981; Wray, Br J Plast Surg 1977):
- Direct approach: incision over orbital rim through skin, orbicularis, and septum simultaneously
- Mid eyelid or subtarsal approach:
- Incision of skin and orbicularis below the tarsus
- Follow the orbital septum to rim, and enter orbit there
- Scars more notable than subciliary, thus subciliary the preferred transcutaneous approach
Transconjunctival incision
- Incision on palpebral conjunctival surface of lower eyelid below tarsus
- Incision can vary in placement: some suggest higher incision at 3–4 mm below the tarsus (Barkhuysen, J Craniomaxillofac Surg 2009; O'Malley OPRS 2008), some suggest lower in the fornix (McCord, Ophthalmology 1981)
- Selection of incision position can be related to plane of approach:
- Superior incision typically access to the preseptal plane (Tessier, J Maxillofac Surg 1973)
- Preseptal requires entry to orbit at inferior rim, through arcus marginalis and orbital septum
- Inferior incision typically access to the postseptal plane (Converse, Plast Reconstr Surg 1973)
- Postseptal enters orbit directly, carrying dissection between orbital fat and septum
- Not much literature comparing efficacy and safety of these two planes and choice is based on surgeon preference
- Both can be performed without opening lateral canthus
- If canthus opened: "swinging eyelid" (McCord, Ophthalmology 1981)
- Might increase exposure to the floor and inferolateral wall
Comparisons of transcutaneous and transconjunctival incisions are typically in reference to orbital floor fracture repair, but can be considered:
- Retroseptal transconjunctival and subciliary skin flap:
- Found incidence of ectropion higher with subciliary (Wray, Br J Plast Surg 1977)
- Comparison of preseptal transconjunctival and subciliary skin-muscle flap approaches:
- Incidence of transient ectropion higher in subciliary group at 12% relative to 0% in transconjunctival (Appling, Arch Otolaryngol Head Neck Surg 1993)
- They also noted > 1 mm of scleral show at 3 months in 28% of transcutaneous and 3% of transconjunctival cases
- Meta-analysis of pooled transconjunctival, subciliary and mid eyelid (Ridgway, Plast Reconstr Surg 2009):
- Highest incidence of
- Ectropion in subciliary (14%)
- Entropion in transconjunctival (0.7%)
- Hypertrophic scars in mid eyelid (3.4%)
- Photographic analysis in post fracture patients of transcutaneous versus transconjunctival:
- Incidence of lower eyelid retraction significantly greater with transcutaneous approach, independent of fracture type (Raschke, Clin Oral Invest 2013)
- Transorbital medial wall
Transcutaneous medial canthus incision
(Lynch, Laryngoscope 1921)
- Incision midway between the medial canthus and the nasal bridge
- Periosteum exposed and subperiosteal plane developed
- Might involve disinsertion of the trochlea, cauterization of the ethmoidal bundles and/or reflection of medial canthal tendon and the lacrimal sac
- Scar and webbing can occur and thus not performed widely today; Z-plasty can be used to repair (Esclamado, Laryngoscope 1989)
Coronal incision
(Mourits, Ophthalmology 1990)
- Extended post-hairline incision over course of scalp and developing complex flap to expose orbit
- Supraorbital nerve freed
- Ethmoidal neurovascular bundles cauterized
- Morbidity of this approach is significant (Baldeschi, Orbit 2010):
- Frontal bossing
- Skin necrosis
- Alopecia
- Anesthesia
- Effective direct approaches are common (Cruz, OPRS 2003) thus coronal decompression is rarely performed today
Transcaruncular incision
(Perry, OPRS 2003)
- Initial incision is usually between the caruncle and plica semilunaris
- Incision carried inferiorly and superiorly to the mid orbit
- Can be combined with transconjunctival or swinging eyelid for access to the floor and inferolateral wall (Shorr, Ophthalmology 2000)
- Posterior to caruncle dissection follows plane between Horner's muscle and the orbital septum
- Access to posterior lacrimal crest and medial orbit
- Avoid damage to the lacrimal sac by direct visualization
Transantral incision via superior gingival sulcus
As described by Ogura and Walsh (Ogura, Laryngoscope 1962):
- Access maxillary sinus via Calwell-Luc antrostomy.
- Incision made in buccogingival sulcus above the canine fossa
- Leave cuff of tissue above gingiva to suture closed
- Periosteum elevated to infraorbital nerve
- Maxillary sinus entered and osteotomy enlarged
- Position of entry into maxillary sinus selected to avoid infraorbital and superior alveolar nerves
- Suggest making antrostomy in the mid-pupillary line at the floor of the nasal vestibule (Robinson, Laryngosocpe 2005)
- Mucosa stripped as necessary from the roof of the sinus
- Ethmoid air cells can be removed medial to the orbit, exposing the medial orbital wall which can then be removed, together with the floor of the orbit medial to the infraorbital nerve (often with Takahashi and Kerrison rongeurs)
- Removal of the medial wall and floor might result in loss of the orbital strut, with increased risk of consecutive diplopia
- Does not produce an external scar
- Complications:
- Paresthesias and anesthesia in almost all patients immediately postoperatively (Weisman, Arch Otolarynol 1994)
- Long-term anesthesia close to 10%
- Oroantral and gingivolabial fistula (about 1% each)
- Devitalized teeth 0.5% of cases (DeFreitas, Laryngoscope 1988)
Transnasal endoscopic incisions
- Endoscopic decompression pioneered in the early 1990s (Kennedy, Archives of otolaryngology--head & neck surgery 1990)
- Variable technique, with general elements:
- Entry into anterior ethmoidal air cell via, classically, an uncinectomy and excision of ethmoid bullae (Kennedy, Arch Otolaryngol 1985)
- Dissection proceeds posteriorly or can be posterior to anterior
- Medial wall of orbit is identified
- Remaining septae removed to anterior wall of sphenoid sinus
- Key anatomic features to be aware of:
- Anterior and posterior ethmoidal neurovascular bundles (Han, Annals Oto Rhino Laryngol 2008)
- Enter nose laterally at the frontoethmoidal suture.
- Anterior ethmoidal in region of the basal lamella of the middle turbinate
- Posterior complex immediately anterior to anterior wall of the sphenoid sinus
- Intraoperative control of bleeding in endoscopic surgery:
- Pledgets soaked in vasoconstricting substances (e.g., oxymetazoline)
- Gentle cautery
- Rarely, major vessel might require endovascular embolization (Isenberg, Otolaryngol Head Neck Surg 1994)
- Topical hemostatic agents: active and passive
- Active: activate biologic clotting system and help form new clots (Gabay, Pharmacotherapy 2013)
- EVICEL Fibrin Sealant (Ethicon, Cincinnati, Ohio)
- TISSEEL (Baxter International Inc., Deerfield, IL)
- Passive: provide template for platelet aggregation and activation (Emilia, Transfus Apheresis Sci 2011)
- Collagen: surgiflo (Ethicon US, LLC) and floseal (Baxter Healthcare Corporation)
- Gelatin: gelfoam (Pfizer Inc) and surgifoam (Ethicon US, LLC)
- Cellulose: surgicel (Ethicon US, LLC)
- Structures to be aware of:
- Basal lamella of the middle turbinate: disinsertion can destabilize the turbinate and exposes internal maxillary vessels
- Fovea ethmoidalis and skull base
- Potential complications:
- Skull base and orbit:
- Orbit:
- Damage to the recti, intraorbital hemorrhage and vision loss are critical complications (Dutton, OPRS 1986)
- Lacrimal sac might be damaged as well (Seiff, AJO 1988)
- Skull base:
- Perforation into cranial cavity superiorly along the low-lying fovea ethmoidalis and cribriform plate can lead to catastrophic complications (Manigilia, Laryngoscope 1981; McCormick, OPRS 2004)
- Small dural leaks can be patched with a number of substances including nasal mucosa, temporalis fascia, fat, muscle, and acellular dermal grafts
- Sphenoid sinus:
- Injury to carotid artery
- Requires immediate control of hemorrhage and rapid transfer for angiographic balloon occlusion (Isenberg, Otolaryngol Head Neck Surg 1994)
- Anatomical knowledge vital, intra-operative image guidance can be useful in preventing problems (Dubin, Annals Oto Rhino Laryngol 2008)
Comparison of incisions and approaches to the medial wall and floor
- Orbital decompression efficacy primarily related to the bone or fat resection:
- Irrespective of incision or approach
- Morbidities can be related to incisions and approaches
- Two studies investigating coronal vs direct approaches to medial wall and floor:
- Gorman et al. compared 10 transantral to 9 transfrontal
- Increased hospitalization, requirement for head shaving and large scar disadvantages of transfrontal
- Lip anesthsia and contraindication in sinusitis disadvantages of transantral (Gorman, NEJM 1974)
- Cruz et al. compared 49 transconjunctival cases with 45 coronal cases
- Morbidity of coronal as per Gorman + described 1 case of vision loss
- Anesthesia of infraorbital nerve noted in transorbital + 1 case of eyelid retraction
- Conclusion was that a coronal flap is unnecessary in most cases (Cruz, OPRS 2003)
- Review papers suggest that coronal approach can involve unique complications (Baldeschi, Orbit 2010; Mourits, BJO 2009):
- Dysesthesia
- Bossing
- Temporalis paralysis
- Flap necrosis
- As compared to periorbital that might have complications related to eyelid malpositions
- Few groups report persistent use of the coronal approach the inferomedial orbit
- Direct comparisons between transorbital, transantral and/or transnasal approaches are uncommon
- Systematic review by Leong et al. (Leong, Laryngoscope 2009), found these rates of complications:
- Transantral 15.6%
- Transnasal 5.2%
- Transorbital:
- Transconjunctival 4.2%
- Transcaruncular 5.8%
- Transcutaneous 12.8%
- Types and severity of the complications are not reported
- It's difficult to draw firm conclusions from data, however, there is a suggestion that transconjunctival/caruncular approaches perform similarly to endonasal, whereas transantral, transcutaneous and coronal might have higher rates of incision-related complications.
Bone removal strategies
Orbital floor
- Any of the above-described approaches provide access to floor and medial wall
- The extent of bone removal varies widely in the literature, as does the treatment of the periosteum, orbital fat and adjacent neurovascular bundles
- Original descriptions floor decompression involve removal of entire floor:
- Posterior to anterior
- Medial and lateral to the infraorbital nerve
- Some cases nerve removed (Moran, Plast Reconstr Surg 1972)
- Modifications later adopted to reduce hypoglobus, strabismus, and numbness:
- Bone removed only medial to the infraorbital nerve
- Anteriorly some suggest leaving 10 mm of bone under globe to prevent hypoglobus or not opening the periorbita (Mainville, OPRS 2014)
Medial orbital wall
Many variations in removal of lamina papyracea have been described:
- Anterior extent:
- Maximal anterior extent is typically the posterior lacrimal crest
- Some described mobilizing lacrimal sac and dissecting anterior to this (Weisman, Arch Otolaryngol 1994)
- Others suggest not to extend anteriorly beyond anterior ethmoidal foramen (Goldberg, Expert Techniques 2015)
- Posterior extent:
- Typically to anterior wall of sphenoid sinus
- Can extend as far as optic canal, some describe canal decompression as part of surgery for dysthyroid optic neuropathy (DON) (Schaefer, Laryngoscope 2003)
- Evidence is not compelling that this is necessary for effective surgical treatment of DON
- In some cases, anterior wall of sphenoid might extend anteriorly and require removal for decompression to annulus of zinn (Gormley, Eye 1997)
- Superior extent:
- Most describe dissection to frontoethmoidal suture.
- At this level, inadvertent entry into cranial cavity through fovea ethmoidalis has been reported (Badilla, Orbit 2008; McCormick, OPRS 2004)
- Ethmoidal neurovascular bundles serve as landmarks for this position
- Inferior extent
- Inferomedial orbital strut separates medial and inferior wall
- Authors have argued for removing this strut in maximal decompression (McCord, Ophthalmology 1981)
- Others suggest leaving the strut to avoid hypoglobus and diplopia (Goldberg, OPRS 1992; Wright, J Otolaryngol 1999)
- Inferomedial posterior:
- Orbital process of palatine bone
- Removal allows for connection of inferior and medial dissections
- Some suggest important in decompression for DON (Goldberg, Expert Techniques 2015)
- Superomedial posterior nasal cavity:
- About 11%–18% of people will have an Onodi cell (Meloni, Surg Rad Anat 1992; Arslan, Auris Nasus Larynx 1999)
- Might be > 50% in Asian populations (Thanaviratananich, Ear Nose Throat J 2003)
- Posterior projection of posterior ethmoid along superiomedial orbital wall and into sphenoid sinus
- Typically abut the optic nerve in this position
- Can extend into orbital apex and can cause apex syndrome when inflamed (Chee, Orbit 2009)
- Decompression for DON might require removal of Onodi cells in some cases
- Preoperative analysis of imaging studies can be helpful
Management of periosteum
- Periosteum will minimize prolapse of tissue after decompression unless opened (Harvey, OPRS 1989).
- Many variations in opening:
- Some suggest opening completely (Perry, OPRS 2003).
- Others suggest cross-hatching (Ogura, J Laryngol Otol 1978) or linear incisions (Platt, Facial Plast Surg 2009).
- Extensive opening of periosteum has been associated with greater rates of postoperative strabismus (Mainville, OPRS 2014).
- Modifications proposed to decrease diplopia:
- Inferiorly: Leave a cuff of periosteum under globe (Seiff, OPRS 2000) or under the inferior rectus (Leone, Arch Ophthalmol 1980).
- Medially: Leave a strip of periosteum medial to the medial rectus (Metson, Laryngoscope 2002).
Management of neurovascular bundles
- Infraorbital nerve options:
- Remove bone only medial to the nerve (most common) (Baylis, Ophthalmology 1980)
- Skeletonize nerve and leave as a hammock (Leone, Arch Ophthalmol 1980)
- Leave bony canal and dissect on either side (Hurwitz, Arch Ophthalmol 1985)
- Can be removed, but will cause significant permanent anesthesia and rarely performed
- Ethmoidal neurovascular bundles:
- Cauterize and clip one or both (Chang, Plast Reconstr Surg 2003)
- Leave both undisturbed (Hurwitz, Arch Ophthalmol 1985)
Proptosis reduction
- Floor alone:
- Average proptosis reduction about 4 mm (Leone, Arch Ophthalmol 1980)
- Inferomedial alone:
- Widely variable effect, dependent on the extent of bony removal, management of the periosteum and adjunctive fat decompression
- Methodological variability makes direct comparison difficult
- Transantral and transorbital: pooled data from multiple centers (Mourits, BJO 2009) and meta-analysis (Leong, Laryngoscope 2009; Borumandi, BJO 2011) suggest:
- Proptosis reduction: 4–5 mm
- Transnasal endoscopic suggest slightly less:
- Proptosis reduction: about 3.5 mm (Mourits, BJO 2009; Leong, Laryngoscope 2009)
Complications: diplopia and strabismus
- Transantral approach:
- Garrity et al. (n = 428) (Garrity, AJO 1993) removed bone medial to infraorbital nerve with crosshatching of the periobita.
- Reported new onset diplopia in 62% of patients
- Other results included mean proptosis reduction: 4.7 mm and improvement or resolution of optic nerve edema and visual field defects in 94% and 91% of patients respectively
- Other studies of transantral technique report similar rates of new onset or worsening diplopia: in the range of 45% to 75% (Tallstedt, Acta Ophthalmol Scand 2000; Fatourechi, Ophthalmology 1994; Warren, Laryngoscope 1989)
- Transnasal and transorbital approaches:
- New onset and worsening diplopia typically less common than transantral
- Many studies with varying technique describe rates in range of 10%–35%.
- Reviewed extensively in multiple publications (Paridaens, Eye 2006; Borumandi, BJO 2011; Leong, Laryngoscope 2009)
- Modifications of transorbital and transnasal proposed to reduce diplopia:
- Bone: some suggest leaving the inferomedial strut intact and thereby reduce globe dystopia (Goldberg, OPRS 1992) and diplopia (Jordan, OPRS 2000; Wright, J Otolaryngol 1999).
- Periosteum:
- No opening of periosteum: no new onset diplopia in a small series (Harvey, OPRS 1989)
- Leave 10–15 mm of periobita intact along floor: no new onset diplopia in a small series (Seiff, OPRS 2000)
- Longitudinal slit versus periosteal excision might reduce new-onset diplopia (May, Otorhinolaryngology 2001).
- Selective periosteal sling over medial rectus also reported to reduce new onset diplopia (Jimenez-Chobillon, Eur Ann Otorhinolaryngol 2010)
- However, note that decreasing periosteal release might lessen proptosis reduction effect.
- Balance competing priorities of diplopia prevention and proptosis reduction.
- Although not a surgical technique issue, it is noteworthy that patients with preoperative motility restriction ("type II" patients) might be more likely to develop new onset or worsening diplopia after decompression (Nunery OPRS 1997) regardless of technique.
Other complications
Complications (uncommon, < 1%) include
- CSF leak
- Epistaxis
- Eyelid and conjunctival swelling
- Sensory anesthesia
- Orbital hemorrhage
- Infection
- Sinusitis
- Vision loss is rare (Garrity, AJO 1993)