Answer:
Canalicular repair:
A. Use loupes or operating scope magnification.
B. The punctum should be located and dilated to allow pasage of a probe to identify the lumen of the canaliculus.
C. Identifying the medial stump can be difficult as it may retract.
D. The most popular method of repair requires passage of silicone tubing wedged onto a metal stent in an encircling fashion through the canalicular-lacrimal system. The intact canaliculus is intubated and the metal probe is passed through the nasolacrimal duct to exit under the inferior meatus. The oppposite end of the tubing is then passed thru the punctum of the lacerated canaliculus and subsequently out of the temporal cut end. It is next passed into the lumen of the medial cut end of the canaliculus, lacrimal sac, and nasolacrimal duct to exit the inferior meatus, thus creating an encircling element.
E. Tension on the tubing approximates the cut ends so that 9-0 sutures can be placed.
F. Suture the deep tissues of the lid and the cut ends of the medial canthal tendon to reduce tension on the repair.
G. If the medial canthal tendon is difficult to locate an additional incision is made over the frontal process of the maxilla, the proximal portion of the tendon is exposed and a selective cantholysis of the inferior crus of the lateral canthal tendon is performed.
H. The Worst pigtail probe is a sharply curved instrument that is inserted into the punctum of the unaffected canaliculus, into the common canaliculus, and back thru the severed canaliculus, where it emerges into the area of the laceration. Silicone tubing is then passed thru the punctum of the cut cannaliculus and exits next to the pigtail probe to which it is affixed. Upon withdrawal of the pigtail probe, the canalicular system, including the laceration, is stented. The external silicone tubes are sutured together and are removed after several weeks.
I. Other methods of canalicular stenting include a Viers or Johnson metal rod. Placement of an encicling silicone tube is the preferred technique.
Dacryocystorhinostomy:
A. Local or general anesthesia.
B. Nasal cavity inspected with a speculum and headlight to determine if there is medial turbinate hypertrophy or septal deviation.
C. Nasal packing soaked in 4% cocaine is insertd into the involved side.
D. Lacrimal punctum is dilated then methylene blue is injected.
E. A skin incision is made slightly below the medial canthal tendon and extended downward and slightly outward for approximately 25 mm.
F. The incision is extended by sharp and blunt dissection to the underlying periosteum of the frontal process of the maxilla and the anterior lacrimal crest.
G. The angular vessels are retracted or ligated as required.
H. A subperiosteal dissection is performed posteriorly over the lacrimal groove as far posterior as the posterior lacrimal crest and inferiorly to the nasolacrimal canal.
I. A circular section of bone approximately 10 mm in diameter is removed from an area situated slightly below and anterior to the lacrimal groove without perforating the nasal mucoperiosteum.
J. The bony opening is enlarged to a diameter of 15-20 mm, the diameter of the sac, which is usually dilated by the accumulation of secretion as a result of the obstruction of the nasolacrimal duct. A vertical I-shaped incision is made through the sac and through the nasal periosteum.
K. The posterior nasal flap is sutured to the posterior flap of the lacrimal sac. A drill hole is prepared for the attachment of the medial canthal tendon.
L. The suturing of the anterior flaps is begun. The transosseous wires have been passsed through the medial canthal tendon.
M. Suturing is completed, wires twisted, and traction is exerted from the contralateral medial wall to maintain fixation of the medial canthal tendon and canthus.