Lacrimal surgery is a sub-specialized area of oculoplastic surgery dealing with the diagnosis and treatment of problems with the lacrimal system, which includes the structures that produce and drain tears.
Common problems that may require lacrimal surgery include blocked nasolacrimal passages, chronic epiphora, and infections of the tear ducts or sac. Dacryocystorhinostomy (DCR) is one of the most common lacrimal procedures.
Oculoplastic surgeons perform DCR to treat nasolacrimal duct obstruction by creating a new drainage pathway for tears from the lacrimal sac directly to the nasal cavity. DCR is performed when the nasolacrimal duct is blocked or narrowed due to a congenital or acquired obstruction.
If not treated, this typically leads to epiphora, discharge, and recurrent infections (dacryocystitis). The DCR procedure can be performed externally or endoscopically.
Overview of external dacryocystorhinostomy
External DCR is the traditional method, which involves making a small incision near the side of the nose, removing a small amount of bone, and then creating a new opening between the lacrimal sac and the nasal cavity. The incision is usually placed in the crease between the nose and the upper cheek, so that it is minimally noticeable once healed.
The procedure is typically performed under general anesthesia and may require a longer recovery time compared to endoscopic DCR. A small silicone tube is then inserted into the new opening into the middle meatus, to keep the new passage patent during the healing process. The tube is usually removed after several weeks or months, depending on the surgeon’s preference.
8 key steps to perform an external DCR
1. Administer anesthesia
The patient is typically given general anesthesia to ensure comfort during the procedure. Local anesthesia, using an equal mixture of lidocaine and bupivacaine, with 1:100,000 epinephrine, is injected into the medial canthus, incision site, and nasal mucosa.
Nasal packing soaked in 4% cocaine, lidocaine, or oxymetazoline is placed to assist with mucosal vasoconstriction in the middle meatus. Hemostasis is critical for DCR surgery.
2. Create the incision.
The surgeon makes a curvilinear incision on the side of the nose near the inner corner of the eye. The precise location of the incision may vary depending on the surgeon's preference and the patient's specific anatomy. Most external DCR incisions are curvilinear shaped and measure approximately 10 to 12mm in length.
3. Access the lacrimal sac.
The surgeon carefully dissects through the soft tissues to gain access to the lacrimal sac. Care must be taken to ensure proper hemostasis, particularly in the area of the angular artery.
4. Create a bony ostium.
Using rongeurs, the surgeon removes a small area of bone from the lacrimal sac and the adjacent nasal cavity. This step creates a connection between the lacrimal sac and the nasal cavity, allowing tears to bypass a blocked or narrowed tear duct.
The anterior and posterior mucosal flaps may be sutured. Any purulent discharge encountered in the lacrimal sac is swabbed and sent for culture.
5. Place the stent or bypass tube.
A silicone tube or stent is inserted into the new opening to maintain its patency and assist in the drainage of tears. This tube may be left in place for weeks to months, depending on the surgeon's preference and the patient's condition.
6. Close the incision.
Once the desired connection is established, the surgeon closes the incision in a layered fashion with sutures. Dissolvable or non-dissolvable sutures may be used to close skin.
7. Provide post-operative care.
After the procedure, the patient is monitored in a post-operative care area. Antibiotic ophthalmic eye drops or ointment are prescribed to prevent infection. The pain usually responds to Tylenol, and nonsteroidal anti-inflammatory drugs (NSAIDs) are avoided to minimize post-operative bleeding and ecchymosis. The patient is instructed to apply ice for the first 48 to 72 hours to minimize edema.
8. Follow-up with the patient.
Follow-up appointments are scheduled to evaluate the healing process, remove any non-absorbable skin sutures at 1 week, remove any temporary stents or tubes at subsequent appointments, and assess the improvement in tear drainage with lacrimal probing and irrigation.
Endoscopic dacryocystorhinostomy
Endoscopic DCR is a newer, less invasive technique that uses an endoscope—a thin tube with a camera—to create a new drainage pathway. This technique is less invasive than external DCR and has the advantage of not requiring an external incision. Instead, small incisions are made inside the nose, and the endoscope is used to guide the surgical instruments.
During the procedure, the surgeon makes a small incision inside the nose and uses the endoscope to locate the lacrimal sac. The bone overlying the sac is removed with a small drill, burr, or rongeurs, and an ostium is created between the sac and the nasal cavity.
The surgeon then places a stent, typically a silicone tube, from the lacrimal punctum and guides it through the canaliculus internally through the new opening, reinforcing the new lacrimal drainage pathway and promote healing. Endoscopic DCR can be performed under general anesthesia or local anesthesia with sedation.
Patient selection for external and endoscopic DCR
Both external and endoscopic DCR can be effective treatments for blocked tear ducts, and the choice between them depends on individual patient factors as well as the surgeon's preferences and experience. Patients typically do very well after DCR, with success rates of up to 90 to 95% for the external approach.
Intranasal evaluation with a handheld endoscope at the time of in-office consultation is helpful in assessing a patient’s candidacy for the endoscopic technique. Good visualization of the middle turbinate and wide nares are positive findings for favorable surgical maneuvering and likely success with endoscopic DCR surgery. Success rates with endoscopic DCR are comparable to those of external DCR.
Advantages of endoscopic DCR:
- Less invasive: The procedure is less invasive, which means there is less tissue damage, less scarring, and less bleeding. Patients may experience less pain and a faster recovery time.
- No external scar: Because there is no external incision, patients do not have a visible scar after the procedure.
- Good outcomes: Endoscopic DCR has been shown to have comparable success rates to external DCR.
Potential disadvantages to endoscopic DCR:
- Higher cost: The equipment used in endoscopic DCR can be more expensive than the instruments used in external DCR.
- Learning curve: Endoscopic DCR can be more challenging for surgeons who are new to using endoscopic equipment.
Complications of DCR
Surgery is not without risks, and complications may occur both during and after DCR surgery.
Intra-operative complications of DCR:
- Scarring
- Hemorrhage
- Cerebrospinal fluid leak from cribriform plate injury
- Canalicular injury
- Orbital injury from rongeurs or drill
- Nasal or lacrimal mucosal damage, preventing proper flap formation
- Lacrimal sump syndrome due to inadequate inferior bone removal
- This may cause DCR failure from a lacrimal sac remnant inferiorly, which retains tears and interrupts transit into the nose
Post-operative complications of DCR:
- Infection
- Hemorrhage
- Premature silicone tube extrusion
- Incomplete improvement, persistent tearing
- Fibrosis or closure of the ostium
- Persistent epiphora and need for additional surgery
- Sinusitis
Further lacrimal procedures to consider
In addition to DCR, other types of lacrimal surgical procedures include:
- Lacrimal probing: This is a minimally invasive procedure in which a thin, flexible probe (typically a Bowman probe) is inserted into the tear duct to open up any blockages.
- Balloon dacryoplasty: This is a technique in which a small balloon catheter is inserted into the tear duct and inflated to open up the blockage.
- Jones tube placement: This involves inserting a small glass tube into the lacrimal system from the conjunctiva into the nasal cavity to bypass any blockages and allow tears to drain properly.
- Canalicular repair: lacerated or obstructed lacrimal canaliculi may be bypassed by mono-canalicular stents (mini-Monoka) or traditional bicanalicular stents
Final thoughts
In summary, DCR surgery is a common oculoplastic surgery performed to treat nasolacrimal duct obstruction by creating a new lacrimal drainage pathway. Residents may assist with external and endoscopic DCR techniques during their ophthalmology training. As with any ophthalmic surgery, proper patient counseling and expectation management are crucial.
Successful DCR surgery improves symptomatic epiphora and is a definitive treatment for dacryocystitis. Immediate recovery time from surgery is typically 1 week, and patients should be counseled that final results are determined once nasolacrimal stents are removed.
