By Laird Harrison; Reviewed by M. Reza Vagefi, MD
With a good knowledge of orbital anatomy, and in surgical good hands, lacrimal canalicular lacerations can be readily repaired without problems, according to M. Reza Vagefi, MD.
Lacrimal canaliculi are the small channels in each eyelid that begin at the puncta and run medially to join at the common canaliculus and drain tears into the lacrimal sac, said Dr. Vagefi, an associate professor of ophthalmology who specializes in oculofacial plastic surgery at the University of California, San Francisco.
“Any injury medial to the puncta has the potential for damage to the canaliculus,” he said. “It is thus important to examine this area very carefully at the time of initial evaluation.”
Some of the most common causes of lacerations to the canaliculi are altercations and assaults, dog attacks, falls, and motor vehicle accidents.
“As the injury proceeds medially, the complexity of repair is increased,” Dr. Vagefi said. Sixteen percent of all eyelid lacerations entail canalicular injury. Of these, 50% are from direct injury and 20% are from indirect forces across the eyelid that avulses it from its insertion point. The remainder is from diffuse trauma across the face associated with other soft tissue injuries.
The lower lid is three times more likely to be involved than upper. “Lacerations through the canaliculi are not always readily recognized, so probing of the system is a good idea,” Dr. Vagefi said.
Surgeons begin the repair by finding the two cut ends of the canaliculus. They introduce a silicone stent through the puncta along the normal track. The stent is attached to a rigid probe that allows the surgeon to pass it through the full course of the lacrimal drainage system.
Finding the cut medial end takes patience and good illumination. It looks like a small, white doughnut in a red tissue bed, he noted.
“There are also tricks, like injecting certain substances through the tear drainage apparatus or using specialized instrumentation to find the cut end,” Dr. Vagefi said.
Evolution in silicone stents has “revolutionized” the procedure, eliminating the need for rods and wires, he said.
While stents go back to the mid-1950s, designs have improved in the past 15 years.
“By bridging that divide where the laceration is we can assure for more controlled, uniform healing and bring the two cut ends back together,” he said.
In the past, surgeons sewed the laceration together with multiple fine sutures often using an operating room microscope. Now clinical series have shown that the stent itself can bring the two ends together.
“Only minimal soft tissue repair around the canaliculus is necessary,” Dr. Vagefi said.
Typically, he puts one or two additional sutures in the pericanalicular area using an absorbable suture to ensure the cut ends are supported without tension as they heal.
Overall success is better in the operating room than in the procedure suite, studies have shown. The operating room offers a more controlled environment with better illumination and the necessary instruments to perform a proper repair.
“On top of that, you have the option of general anesthesia or deep sedation,” Dr. Vagefi said. “Often it’s difficult for patients to sit through this type of repair, especially with the nasal manipulation needed to retrieve some stents. Also, local anesthesia in the wound bed is best avoided as it can distort the wound and conceal the cut canalicular ends.”
Several controversies remain, Dr. Vagefi noted.
1. How long after the injury can the surgery be successful? Many studies recommend operating within 48 hours, and some stretch that interval to 5 days. At least one researcher has reported good results up to 10 days. Dr. Vagefi prefers to repair these injuries within a week of the incident.
2. Should you repair a mono-canalicular obstruction? In the past, all stents had two arms, one for each canaliculus, and surgeons were afraid of damaging the healthy canaliculus by inserting the arm intended for it, Dr. Vagefi explained.
Research has demonstrated that the superior and inferior canaliculi have equal roles in lacrimal drainage. Other studies have shown minimal to no impairment of tear drainage with occlusion of one puncta and no symptoms of tearing.
But other patients do develop symptoms from damage to only one canaliculus. With the mono-canalicular stents now available, the risk of repair is minimal, Dr. Vagefi said.
“You need to do the best possible for the patient and ensure that they have an intact tear drainage system because you cannot predict who will develop tearing had the repair not been performed,” he said.
3. What probes are safe to use? The pigtail probe had a “less-than-glamorous introduction” in 1962, Dr. Vagefi said. A barbed end tended to rip through canalicular system when withdrawn, he said.
Twelve years later, CK Beyer introduced one with a blunt probe and islet. Surgeons have since demonstrated its efficacy and safety.
4. When should the stents be removed? There is no consensus, said Dr. Vagefi, but animal models suggest the best time is about 3 months after the surgery because that is when the healing process has finished.
5. Who should do the procedure? Citing a recent article (Ophthal Plast Reconstr Surg. 2014;30:410-414), Dr. Vagefi said training makes a significant difference. Oculofacial plastic surgeons have the best success, followed by their fellows.
M. Reza Vagefi, MD
This article was adapted from Dr. Vagefi’s presentation during Oculofacial Plastic Surgery Subspecialty Day at the 2016 meeting of the American Academy of Ophthalmology. He did not indicate any financial interest in the subject matter.