Dacryocystorhinostomy indications

Dacryocystorhinostomy (DCR) involves removal of the bone lying between the lacrimal sac and the nose, with anastomosis between the lacrimal sac and nasal mucosa; the lacrimal sac, with the internal opening of the common canaliculus, is incorporated into the lateral wall of the nose and provides a direct route for tears to reach the nose.

The usual indication for DCR is complete or partial obstruction of the nasolacrimal duct: such obstruction can cause skin excoriation, visual impairment, social embarrassment, chronic ocular discharge and acute or chronic dacryocystitis. Less common indications for DCR include lacrimal calculi, facial nerve palsy, gustatory lacrimation (crocodile tears), and lacrimal sac trauma. In the presence of lacrimal sac mucocoele, DCR is mandatory prior to intraocular surgery because of the risk of post operative endophthalmitis.

Patients with acute dacryocystitis require treatment with systemic antibiotics prior to undertaking DCR.

Anaesthesia

Open lacrimal surgery can be performed under general or local anaesthesia. Local anaesthesia with sedation provides excellent intraoperative haemostasis, but may be associated with somewhat prolonged post operative nasal oozing. Some patients and surgeons, however, prefer general anaesthesia with controlled intraoperative hypotension; with newer short-acting anaesthetic drugs, daycase surgery under general anaesthesia is readily achievable in most cases.

Local anaesthesia is particularly useful for elderly or debilitated patients who are unfit for general anaesthesia. The anterior nasal space is sprayed with 4% lignocaine and packed with

1-2m of 12-5mm ribbon gauze thoroughly moistened with 2ml of a 10% cocaine solution, this producing very effective intranasal anaesthesia and mucosal vasoconstriction. Using angled nasal forceps, short loops of the ribbon gauze are firmly packed far anteriorly and superiorly within the nasal space - high against the lateral wall of the nose and the anterior aspect of the middle turbinate, at the site of the proposed rhinostomy. Although not essential, the headlight and nasal speculum may aid correct placement of the nasal pack. A regional block of the anterior ethmoidal branch of the nasociliary nerve is given by infiltration of

2-3ml of 0-5% bupivacaine with 1:200,000 adrenaline along the medial wall of the orbit, immediately above the medial canthal tendon and below the trochlea. Additional anaesthesia and vasoconstriction at the site of incision is achieved by skin infiltration with 2-3ml of the same local anaesthetic preparation. To achieve maximal vasoconstriction, the local anaesthetic should be administered at least 10 minutes before surgery commences and may usefully be given just prior to scrubbing, skin preparation and sterile draping; topical ocular anaesthesia, such as 0.5% amethocaine eyedrops, is also required at the time of surgery.

Vasoconstriction and haemostasis

During local anaesthesia, nasal packing with cocaine generally provides sufficient vasoconstriction of the nasal mucosa, although during surgery it can be supplemented by the intramucosal or submucosal injection of a local anaesthetic (such as 2% lidocaine) with 1:200,000 adrenaline. With this technique, intraoperative bleeding tends to be minimal and any oozing into the nasal space may be readily aspirated with a 12G bronchial aspiration catheter placed within the mid-nasal space throughout the procedure. Where general anaesthesia is used, vasoconstriction of the nasal mucosa is equally important and, after preparation of the sterile field, is most conveniently achieved by placing three cotton-tipped applicators, moistened with 1:1000 adrenaline, high in the antero-superior nasal space. Infiltration of local anaesthetic with adrenaline at the site of the skin incision further contributes to vasoconstriction and haemostasis, but is not essential in general anaesthetic cases.

Apart from vasoconstriction, several factors help to reduce or control perioperative haemorrhage. Controlled hypotension during general anaesthesia greatly facilitates the surgery and significant bleeding is unusual with a systolic blood pressure below 90mmHg. A head up tilt also reduces cephalic venous pressure and is helpful during both general and local anaesthetic cases. The continuous use of a sucker in the nondominant hand is a mainstay to aiding viewing, and to displacing tissues and protecting them from other instruments. The appropriate use of bipolar diathermy, careful handling and retraction of the tissues, respect for the surgical planes, and widespread suturing of mucosal flaps, also help to control haemorrhage during open lacrimal surgery. The judicious use of bone wax may, rarely, be necessary to stop persistent haemorrhage from bone.

Surgical technique

A 12-15mm straight skin incision (8-10mm in children), starting just above the medial canthus and extending inferiorly, is made just medial and parallel to the angular vein (Figure 15.1). A straight incision in the thick paranasal skin tends to heal rapidly with an imperceptible scar, whereas more posterior incisions in the concavity of the thinner eyelid skin sometimes heal with a contracted, bridging scar (Figure 15.2). The incision should involve only skin and should not be carried straight down to the bone, as marked haemorrhage is common with the latter approach, due to disruption of the orbicularis muscle and the angular vessels.

The skin is bluntly dissected from the underlying orbicularis oculi muscle, using blunt-tipped scissors directed posteriorly, and the pretarsal and preseptal parts of the orbicularis muscle separated along the line of the fibres down to the bone of the lacrimal crest, using scissors in a spreading motion just lateral to the angular vein. A squint hook is used to retract the preseptal orbicularis and angular vessels medially and any bleeding vessels are carefully cauterised.

A Rollet's rougine is used in an oblique, spreading mode to incise the periosteum on the anterior lacrimal crest, starting at the inferior edge of the medial canthal tendon and

Angular vein

Angular Vein Dcr Surgery

Figure 15.1 Incision for external dacryocystorhinostomy (bold line), just medial to the angular vein; the position relative to the medial canthal tendon and lacrimal system (dotted line) is indicated.

Medial canthal tendon

Naso-lacrimal duct

Figure 15.1 Incision for external dacryocystorhinostomy (bold line), just medial to the angular vein; the position relative to the medial canthal tendon and lacrimal system (dotted line) is indicated.

Figure 15.2 Bowed scar due to contracture in a posteriorly-placed dacryocystorhinostomy incision.

extending to the origin of the nasolacrimal duct. Using the sharp cutting edge of the Rollet's rougine, the medial canthal tendon is transected close to its insertion, the periosteum divided up to the top of the lacrimal sac fossa and the paranasal periosteum reflected as far anteriorly as possible. The sucker is used to displace the lacrimal sac laterally, with its periosteal covering, as the periosteum is stripped backwards as far as the posterior lacrimal crest. At this stage 2/0 silk traction sutures may be passed through the anterior periosteal edge, with encirclement of the orbicularis muscle and angular vessels, and the sutures clipped under tension to the surgical drapes. Similar sutures are used to encircle the orbicularis laterally, the increased surgical exposure and haemostasis being particularly useful for the less-experienced surgeon (Figure 15.3). With local anaesthesia, traction sutures are not possible and a small, self-retaining retractor is a useful alternative.

Having exposed the whole lacrimal sac fossa, the pack or cotton-tipped applicators are removed from the nasal space and the thin bone at the suture between the lacrimal bone and the frontal process of the maxilla is breached with a Traquaire's periosteal elevator. In cases where the bone is extremely thick, a curved haemostat may be required to make the initial break or, failing that, a hammer and chisel may be used to thin the anterior lacrimal crest until the bone can be breached. Some surgeons prefer to use a burr or trephine.

Figure 15.3 Traction sutures are useful for increasing exposure of the operative site, especially for the surgeon in training.

A large rhinostomy is fashioned using bone punches, trephine or a burr. When using punches, it is easiest to first enlarge the opening to at least 1cm in front of the anterior lacrimal crest, as far superiorly as possible; the Traquaire's periosteal elevator being used in a sweeping motion, between bites, to separate the underlying nasal mucosa from the bone. The mucosa is more adherent and more friable anteriorly, where greater care is required. Bone removal from the side of the nose, anterior to the frontal process of the maxilla, is directed inferiorly to about the level of the orbital floor - thereby creating an L-shaped rhinostomy (Figure 15.4); in so doing, the thick bone of the anterior lacrimal crest is significantly weakened and removed relatively easily with a downward-cutting bone punch. The thin bone lying between the upper part of the nasolacrimal duct and the nasal mucosa, the hamular process of the lacrimal bone, is then removed using a Jensen bone nibbler. Attention is now directed superiorly, where further bone should be carefully removed to extend the rhinostomy to the skull base; this is essential to ensure that the internal opening of the common canaliculus is not obstructed by bone or scarring after surgery. Excessive tearing forces should be avoided during bone removal from the upper part of the rhinostomy, as this may very rarely result in a hairline fracture of the cribriform plate and cerebrospinal fluid leak. The rhinostomy should extend posteriorly into the anterior ethmoid air cells, where it is generally necessary to remove small flakes of ethmoid bone to allow an adequate mucosal anastomosis.

Having completed the rhinostomy, a "00" Bowman lacrimal probe is passed via the inferior canaliculus into the lacrimal sac. The probe tents the medial wall of the sac (Figure 15.5), which is then incised using a No. 11 style blade, directed away from the internal opening of the common canaliculus to avoid damaging it. The sac must be widely

Rhinostomy
Figure 15.4 Creating the rhinostomy: the arrows indicate the easiest direction of bone removal, relative to the lacrimal sac (dotted line).

opened from the fundus down into the nasolacrimal duct using Westcott scissors or Werb's angled scissors and a common error is to open the relatively thick overlying fascia only, leaving the very thin sac mucosa intact. The lumen of the sac should be examined and the free patency of the internal opening of the common canaliculus confirmed; if the opening is obstructed by a membrane, the obstruction should be carefully excised, using Westcott scissors or a No. 11 blade, and silicone intubation placed.

Being careful to avoid damage to the nasal septum, the nasal mucosa is incised with a

Canalicular probe

Figure 15.5 Creating mucosal flaps: the canalicular probe tents the medial wall of the lacrimal sac and the dotted lines indicate incisions in the lacrimal sac and nasal mucosa.

Canalicular probe

Figure 15.5 Creating mucosal flaps: the canalicular probe tents the medial wall of the lacrimal sac and the dotted lines indicate incisions in the lacrimal sac and nasal mucosa.

No. 11 blade to create a larger anterior flap (about two-thirds of the antero-posterior extent) and a smaller posterior flap and, after cauterisation wherever possible, relieving incisions are made at the superior and inferior bone edges to mobilise both flaps. Incising the nasal mucosa often results in some bleeding which, under general anaesthesia, can be controlled by passing the sucker up the nose and positioning it just behind the posterior flap - thus acting similarly to the second, intranasal "sump" drain placed during surgery under local anaesthesia. A 6/0 absorbable suture on an 8mm diameter half-circle needle is passed through the middle of the free edge of the anterior nasal flap and the ends secured with a bulldog clip, with the needle left attached. This is slung across the nasal bridge to retract the anterior flap medially whilst suturing the posterior flaps (Figure 15.6).

The posterior mucosal flaps are approximated and sutured using a similar 6/0 absorbable suture, the needle being reverse-mounted in an angled, non-locking needle holder in such a way that its entire length is used - this facilitating maximum suture rotation at quite a distance below the small incision. Either a locked continuous suture, or three or four interrupted sutures, is placed from the sac to the nasal mucosa. Keeping the

Lacrimal probe

Lacrimal probe

Figure 15.6 Anastomosis of the posterior mucosal flaps, with the anterior nasal mucosal flap held aside by a traction suture resting across the nasal bridge.

lacrimal probe in the sac helps to identify and protect the internal opening while the mucosal flaps are being united, and this can later be replaced by intubation where there is common canalicular disease or a markedly inflamed lacrimal sac. The absorbable suture retracting the anterior nasal flap is then used to unite the anterior mucosal flaps and three or four sutures are usually necessary to secure a good anastomosis (Figure 15.7). The cut medial canthal tendon is sutured to the medial periosteum using the same suture, and closure of the orbicularis is not usually necessary if the fibres were bluntly separated in the plane between the palpebral and orbital parts. Skin closure is achieved with 6/0 nylon interrupted or continuous mattress sutures, antibiotic ointment instilled into the conjunctival sac, and a pressure dressing applied to the incision. Post operative haemorrhage is infrequent with primary anastomosis of the mucosal edges, and packing of the nasal space is not required routinely, but an adrenaline-moistened pack may be placed if there is persistent brisk haemorrhage after surgery is completed; such a pack should be left undisturbed for five days.

Post operative management

In the immediate post operative period the patient is nursed semi-erect on bed rest to

Figure 15.7 Closure of the anterior mucosal flaps.

Figure 15.6 Anastomosis of the posterior mucosal flaps, with the anterior nasal mucosal flap held aside by a traction suture resting across the nasal bridge.

Figure 15.7 Closure of the anterior mucosal flaps.

reduce the nasal venous congestion that can contribute to nasal oozing and, for similar reasons, hot drinks should be avoided for 24 hours. A topical combined antibiotic and antiinflammatory medication is prescribed for a few weeks and, unless systemic antibiotics have been given during surgery, a short course of oral antibiotics is recommended to reduce the incidence of post operative infection. The pressure dressing is removed on the first post operative day and nose blowing discouraged for the first week, to reduce the risk of secondary epistaxis or subcutaneous emphysema. Skin sutures are removed at about one week after surgery and the intubation at about four weeks after surgery, by which time epithelialisation of the surgical fistula has been completed.

Complications

Serious complications due to external lacrimal surgery are extremely rare, but there are several minor complications (Box 15.1).

In cases of severe continued haemorrhage, nasal packing may be required either with ribbon gauze moistened with a mixture of 1:1000 adrenaline and antibiotics, with an absorbable haemostatic sponge, or with a commercially available expanding nasal tampon.

Minor leak of cerebrospinal fluid may, extremely rarely, result from an inadvertent fracture of the cribriform plate. Once identified, the site of leakage may be plugged with a slip of orbicularis oculi muscle obtained from the surgical field, and post operative systemic antibiotics administered. Although most cases resolve without further complication, close post operative monitoring is required for continued CSF rhinorrhoea or meningitis and neurosurgical advice is recommended.

Orbital fat prolapse may occur if the lateral wall of the lacrimal sac or the orbital periosteum is breached while incising the lacrimal sac or performing a membranectomy. To avoid the risk of orbital haemorrhage,

Box 15.1 Complications of external lacrimal surgery

Peri-operative

• Canalicular damage

• Haemorrhage

• Cerebrospinal fluid leak

• Inadvertent orbital entry

Post operative

• Haemorrhage

• Wound infection

• Wound necrosis

• Preseptal/orbital cellulitis

Hypertrophic scar

• Lacrimal tube prolapse

• Medial migration (cheesewiring) of lacrimal tubes traction on the orbital fat should be avoided in such cases, but a small fat prolapse does not require any specific treatment.

Whilst early post operative nasal oozing is common and requires no treatment except upright positioning of the patient and avoidance of hot beverages, continued brisk primary haemorrhage is very rare. If simple measures, such as pinching of the nasal bridge or icepacks applied to the nasal bridge, do not control brisk primary haemorrhage, then the nose should be packed with 12-5mm ribbon gauze moistened in 1:1000 adrenaline, the pack being left undisturbed for five to seven days and a systemic antibiotic given for that period.

Prophylactic systemic antibiotics reduce the risk of post operative infection (Figure 15.8) and probably reduce the risk of surgical failure. A single dose of a systemic antibiotic is as effective as a post operative course, but antibiotics should be continued after surgery where there has been significant preoperative infection, placement of a nasal tamponade, or significant primary or secondary epistaxis. Use of nasal packs also increases the risk of post operative infection.

Dacryocystorhinostomy Scar
Figure 15.8 Early post operative infective cellulitis around the dacryocystorhinostomy site.

Figure 15.9 Post operative skin necrosis at the dacryocystorhinostomy incision in a patient with previous radiotherapy.

Although the incision line after almost all external DCR is imperceptible by six months, the incision may rarely heal with excessive scar contracture, especially with posteriorly sited incisions (Figure 15.2). Subcutaneous sutures may also increase the tendency to hypertrophic scar formation. Prominent scars may become less noticeable as they mature, especially if massaged or if pressure is applied by, for example, the wearing of glasses on the scar. Very rarely revision of an operative scar is required for unacceptably tight scars, and generally involves a double Z-plasty technique. Wound necrosis is occasionally seen at the incision margins after prior radiotherapy or in patients with Wegener's granulomatosis (Figure 15.9).

Summary

External DCR surgery is a safe and effective procedure for managing troublesome epiphora.

With attention to patient preparation, meticulous surgical technique, an appreciation of the surgical anatomy and careful tissue handling, the surgery should not be unduly difficult and success rates are unmatched by other techniques. For patients without canalicular or lid abnormalities, the "volume" symptoms (due to retention of fluid within the lacrimal sac) can be cured in everybody, whereas "flow" symptoms (due to the tear line height) are affected by canalicular conductance and these symptoms will be improved in at least 95% of cases. Failure is usually due to inadequate primary rhinostomy, failure to create a primary epithelial anastomosis, excessive fibrosis at the rhinostomy site (due to secondary intention healing), stenosis of the canalicular system, or lid abnormalities.

Further reading

Dresner SC, Klussman KG, Meyer DR, Linberg JV. Outpatient dacryocystorhinostomy. Ophthalmic Surg 1991; 22:222-4.

Ezra EJ, Restori M, Mannor GE, Rose GE. Ultrasonic assessment of rhinostomy size following external dacryocystorhinostomy. Br J Ophthalmology 1998; 82:786-9.

Hanna IT, Powrie S, Rose GE. Open lacrimal surgery: a comparison of admission outcome and complications after planned daycase or inpatient management. Br J Ophthalmol 1998; 82:392-6. Hartikainen J, Grenman R, Pukka P, Seppa H. Prospective randomized comparison of external dacryocystorhinostomy and endonasal laser dacryocystorhinostomy. Ophthalmology 1998; 105:1106-13. Jordan DR. Avoiding blood loss in outpatient dacryocystorhinostomy. Ophthal Plast Reconstr Surg 1991; 7:261-6.

Jordan DR, Miller D, Anderson RL. Wound necrosis following dacryocystorhinostomy in patients with Wegener's granulomatosis. Ophthalmic Surg 1987; 18:800-3.

Linberg JV. Lacrimal surgery; contemporary issues in ophthalmology volume 5. New York: Churchill Livingstone, 1988.

McNab AA. Diagnosis and investigation of lacrimal disease. In McNab AA. Manual of orbital and lacrimal surgery (2nd ed.) Oxford: Butterworth Heinemann, 1988. Neuhaus RW, Baylis HI. Cerebrospinal fluid leakage after dacryocystorhinostomy. Ophthalmology 1983; 90:1091-5. Tarbet KJ, Custer PL. External dacryocystorhinostomy. Surgical success, patient satisfaction, and economic cost. Ophthalmology 1995; 102:1065-70. Walland MJ, Rose GE. Soft tissue infections after open lacrimal surgery. Ophthalmology 1994; 101:608-11.

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Responses

  • GILLY
    What is the use of adernaline in dcr surger?
    2 years ago
  • TONY
    What is the dacryocystorhinostomy?
    2 years ago

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