The overall goal of this procedure is to create a tier bypass in cases of absolute infrasacal nasolacrimal duct obstruction. This modern procedure offers the possibility to effectively treat nasolacrimal duct obstruction safely and quickly, while at the same time reducing complication rates when compared to established protocols. The main advantage of this technique is that it is minimally invasive.
After putting the patient under general anesthesia, according to the text protocol, insert the video-assisted endoscope into the nasal cavity by carefully advancing it through the nostril. Tilt the endoscope towards the lateral nasal wall to visualize the anterior margin of the middle turbinate. Next, put on protective glasses and set up the laser equipment by connecting the laser fiber optic to the diode laser.
Set the diode laser to six to eight watts, 200 millisecond pulse duration and 100 millisecond exposition pause. Fit the laser fiber optic into the handpiece for maneuvering and then through a blunt cannula. Let two to three millimeters of the fiber stick out at the tip of the cannula.
Perform carbonization of the laser fiber tip by holding it on a wooden spatula and applying laser energy for a few seconds, until the tip is sufficiently blackened. This will limit unwanted energy distribution to the lacrimal sac. Next, to dilate the upper and lower punctum, insert a lacrimal probe, vertically at first, and then position it horizontally before further advancing it towards the lacrimal sac.
Begin by vertically inserting the laser fiber into the lower canaliculus before tilting it toward the temple horizontally, to follow the physiological formation of the lower canaliculus. Carefully advance the laser fiber into the lacrimal sac until it touches the lateral nasal wall, i.e. the medial lacrimal sacal wall.
Then, aim the tip in an anteroinferior direction so that it points to the anterior margin of the middle turbinate. To create a sufficient nasolacrimal bypass while maintaining constant contact to the nasal wall while not applying pressure, vaporize the tissue by applying laser energy. It is very important that the laser fiber is not actively pressed to the wall or subjected to lateral stress.
This is because retraction or breaking of the fiber may cause heating of the metal cannula, therefore causing thermal injury. When the lateral nasal wall has been penetrated, pull the laser fiber back a bit and enlarge the ostium by carefully vaporizing the margins in a circular manner. Try to create as large a bypass as possible.
Using a Bangerter probe, verify the patency of the ostium by saline irrigation. If a patent ostium was created, successful irrigation should be visible endoscopically. Through the lower punctum, insert a monocanalicular silicone tube and carefully advance it until the leading metal tip passes the bony ostium and protrudes into the nasal cavity.
Use Blakesley forceps to grab the tip from inside the nasal cavity and pull the silicone tube out of the nose and into position. And then, use a pair of scissors to cut them short. Perform silicone intubation via the upper canaliculus and remove the endoscope.
Then, use a pair of scissors to shorten the silicone tubes so that the ends are not sticking out of the nose. Carry out postoperative care according to the text protocol. Upon examination, the day after transcanalicular laser-assisted DCR, a little swelling of the eyelid can be present in about 60%of cases.
This slight swelling always resolves completely within a maximum of three days. However, because bicanalicular silicone intubation is performed during the procedure, epiphora may persist until the tubes are removed. This table gives an overview of the results.
Functional success, meaning complete resolution of symptoms at the six months mark, can be achieved in 78%of patients. In about 22%of cases, restenosis may occur. The most likely reason is scar tissue forming in the bony ostium and secondary external DCR can become necessary.
Serious complications are rare, however, when the utilized laser equipment is not handled carefully, the tip of the laser fiber can slip back into the metal cannula, which will cause heating of the metal. This results in thermal injury to the canaliculus or lacrimal sac. In conclusion, laser DCR is a minimally invasive technique with high functional success rates, few complications and no need for a skin incision.
Once mastered, this technique can be done in 15 to 25 minutes if it is performed properly. While attempting this procedure, it's important to remember to create as large an ostium as possible since smaller diameter osteotomies facilitate early scarring. If following this procedure, restenosis occur, secondary external dacryocystorhinostomy can still be performed without an increase in complication rates.
After its development, this technique paved the way for researchers in the field of oculoplastics to further explore laser-assisted lacrimal bypass surgery and its possible combinations with the use of fibrosis inhibiting drugs and internasal apparatus. After watching this video, you should have a good understanding of how to perform transcanalicular dacryocystorhinostomy using a diode laser to create nasal lacrimal bypass. Don't forget that working with lasers can be hazardous and precautions, such as wearing protective goggles, should always be taken while performing this procedure.
