Anatomical Relation between Anterior Ethmoidal Sinus and Lacrimal Sac Fossa on High Resolution CT

PURPOSE: To evaluate the anatomical relation between anterior ethmoidal sinus and the lacrimal sac fossa, and thus help prevent complications during dacryocystorhinostomy. MATERIALS AND METHODS: Fifty three people without previous history of trauma, surgery, or paranasal sinus disease were randomly selected, and the 106 lacrimal sac fossas of these subjects were evaluated by high resolution CT. A series of three 2-mm thick axial sections at least 2 mm from the inferior orbital wall were obtained. The bony landmarks of the lacrimal sac fossa were established and the location of the most anterior ethmoid sinus was classified as one of three types. In type 1, no sinuses were anterior to the posterior lacrimal crest. while in type 2, sinuses extended anterior to this crest but remained behind the suture at the anterior edge of the lacrimal bone. In type 3, sinuses extended into the frontal process of the maxilla, anterior to the lacrimal bone suture. In addition, the category of both orbits of the same patient was compared. RESULTS: Among the 106 orbits examined, only seven (6.6%) were classified as type 1, with no ethmoid air cells positioned under the lacrimal sac fossa. Seventy six (71.7%) qualified as type 2, while the remaining 23 (21.7%) were type 3, demonstrating anterior ethmoid air cells within the nasal process of the maxilla. The position of the air cells was symmetric in 41 of the 53 subjects (77.4%) and asymmetric in 12 (22.6%). CONCLUSION: In cases involving surgery of the lacrimal sac fossa, such as dacryocystorhinostomy, a knowledge of the consistent anatomic relationship between the anterior ethmoidal sinus and the lacrimal sac fossa is invaluable.

Anatomical Relation between Anterior Ethmoidal Sinus and Lacrimal Sac Fossa on High Resolution CT

PURPOSE: To evaluate the anatomical relation between anterior ethmoidal sinus and the lacrimal sac fossa, and thus help prevent complications during dacryocystorhinostomy. MATERIALS AND METHODS: Fifty three people without previous history of trauma, surgery, or paranasal sinus disease were randomly selected, and the 106 lacrimal sac fossas of these subjects were evaluated by high resolution CT. A series of three 2-mm thick axial sections at least 2 mm from the inferior orbital wall were obtained. The bony landmarks of the lacrimal sac fossa were established and the location of the most anterior ethmoid sinus was classified as one of three types. In type 1, no sinuses were anterior to the posterior lacrimal crest. while in type 2, sinuses extended anterior to this crest but remained behind the suture at the anterior edge of the lacrimal bone. In type 3, sinuses extended into the frontal process of the maxilla, anterior to the lacrimal bone suture. In addition, the category of both orbits of the same patient was compared. RESULTS: Among the 106 orbits examined, only seven (6.6%) were classified as type 1, with no ethmoid air cells positioned under the lacrimal sac fossa. Seventy six (71.7%) qualified as type 2, while the remaining 23 (21.7%) were type 3, demonstrating anterior ethmoid air cells within the nasal process of the maxilla. The position of the air cells was symmetric in 41 of the 53 subjects (77.4%) and asymmetric in 12 (22.6%). CONCLUSION: In cases involving surgery of the lacrimal sac fossa, such as dacryocystorhinostomy, a knowledge of the consistent anatomic relationship between the anterior ethmoidal sinus and the lacrimal sac fossa is invaluable.

Insertion of a Self-expandable Metallic Stent in Canine Lacrimal Sac: A long-term Evaluation

PURPOSE: To evaluate the feasibility and long-term outcome of the use of self-expandable metallic Z-stents inthe canine lacrimal sac. MATERIALS AND METHODS: Stents were constructed using 0.1 mm stainless steel wire in acylindric zigzag configuration of four bends; their diameter when fully expanded was 2.4 to 3mm, their length was6.0 to 8.0mm, and they were coated with 24-karat gold. Under fluoroscopic guidance and using a 3F cutdown tube, atotal of 12 stents were placed in 12 lacrimal sacs of six adult dogs, which were observed for tearing. After onemonth to three years of observation, the dogs were sacrified and examined grossly and histologically. RESULTS: Stent placement was technically succussful and well tolerated in all but one lacrimal sac, in which the stent wasmisplaced. At three and six months after stent placement, stent wires were not encased by epithelium, but at ninemonths, and one, two and three years after placement, six of the 12 stents had become encased in a proliferationof this where the stent wires contacted the lacrimal sac wall. In no lacrimal system in which stent placement hadbeen successful was migration, stenosis or obstruction of the lacrimal system observed. One misplaced stent causedobstruction of the lacrimal sac, however. CONCLUSION: In 11 of 12 case (92%), fluoroscopic placement of anexpandable metallic stent in the canine lacrimal sac was successful; in 6 of 8 cases (75%), the stent wires becameencased by a proliferation of mucosa, but during long-term follow-up of 9 months to 3 years, no obstruction wasobserved.

Fractures of the Nasolacrimal Fossa and Canal: CT Findings and Clinical significance

PURPOSE: This study aimed to determine the CT findings of nasolacrimal fossa and their clinical significance. MATERIALS AND METHODS: Twenty-nine of 116 patients who underwent facial CT scanning after trauma showed evidenceof nasolacrimal fracture. We retrospectively analyzed CT findings to evaluate fracture patterns of thenasolacrimal fossa and canal and associated facial fractures. To determine the frequency of associatedcomplications, clinical records were reviewed were reviewed. RESULTS: Three types of fracture were identified:avulsion, comminuted, and linear Forty-one nasolacrimal fractures, 20 of which involved the nasolacrimal fossa and21 the nasolacrimal canal, were found in the 29 patients. Of the 20 fractures involving the nasolacrimal fossa,ten were avulsion, eight were linear, and two were comminuted. Seventeen of 21 fractures involving thenasolacrimal canal were comminuted and four were linear ; all nasolacrimal fractures were associated with otherfacial fractures. Twenty-five of 29 fractures were the complex midfacial-type (naso-ethmoid) ; the remaining fourwere simple and unilateral. Nasolacrimal sac and dvct-related complications were documented in only two patients ;they experienced epiphora associated with avulsion fracture of the nasolacrimal fossa, though the problem wasresolved by conservative treatment without surgery. CONCLUSION: Fractures of the nasolacrimal fossa and canalwere accompanied by simple or complex facial fractures. Injury-associated complications were rare, and all wereassociated with avulsion fractures of the nasolacrimal fossa.

Invention of a Nasolacrimal Stent Retrieval Hook

PURPOSE: To evaluate the clinical usefulness of a nasolacrimal stent retrieval hook. MATERIALS AND METHODS:The retrieval hook consisted of two parts, a hook and pusher. The head of the hook part was made of 0.7 mm stainless steel wire and was question mark-spaped, while the body of this part was constructed by soldering together four stainless steel pipes ranging in thickness from 1.25 to 3.5 mm, serially. The pusher part was made of two plastic tubes and was designed in such a way that the hook grasped the stent tightly. The device was used to remove 46 stents in 40 patients, and tested for 1) average number of trials ; 2) success rate; and 3) average time of the procedure. RESULTS: The average number of trials, success rate, and average time taken to remove the stent was 4.7, 91%, and 1.8 minutes, respectively. CONCLUSION: In the removal of nasolacrimal stents, the retrieval hook was easy to use, useful and effective.

Nasolacrimal Duct Stent Insertion: Causes of Insertion Failure and Reobstruction

PURPOSE: We performed this study to evaluate the most common site of the nasolacrimal systemic obstruction and causes of the nasolacrimal stent insertion failure and reobstruction following the insertion of the stent. MATERIAL AND METHODS: Nasolacrimal stent insertion was attempted in 26 cases(24 patients) of 30 cases (25 patients) with complete obstruction of the nasolacrimal system at the dacryocystography. We retrospectively assessed the obstruction site of nasolacrimal system, and evaluated the rate and causes of stent insertion failure and reobstruction following insertion of the stent on follow-up. RESULT: The obstructive sites of then asolacrimal system were junction level of the lacrimal sac and nasolacrimal duct(80%), common canaliculi(10%),and nasolacrimal duct(10%). In seven cases, we failed to insert the nasolacrimal stent. Four of the seven cases had a history of previous operation on paranasal sinus or nasolacrimal system. At 4 weeks follow up, epiphorare developed in four of 10 cases(reobstruction rate, 40%). Inflammatory process around the nasolacrimal duct stent was conndered to be the cause of reobstruction in two of the four reobstructed cases. CONCLUSION: Success rate of nasolacrimal duct stent insertion was 73%, and failure rate was 27%. The causes of the stent insertion failure included fibrosis and granulation tissue due to the previous operation around nasolacrimal duct system and paranasal sinus area. Inflammatory process around the stent caused recurrent obstruction.

Usefulness of a Hook in Nasolacrimal Balloon Dilatation and Stent Placement

PURPOSE: To evaluate the usefulness of a hook developed for pulling out the guide wire in nasolacrimal balloon dilatation and stent placement. MATERIALS AND METHODS: The head was made of stainless steel wire in ashape of a question mark, and the body was made of four stainless steel pipes. The head was attached to the body in three different ways : A) the head was anterior to the body, B) the head was posterior to the body, and C) the head was angled of 30 degrees forward from the direction of the body. 90 epiphora patients took part in a test tocompare and evalvate the usefulness of different types of hook. Average number of trials, success rate and average time of the procedure were recorded. RESULTS: The average trial number for different attachment methods A, B, andC was 4.5, 6.4, and 2.5, respectively, and the success rate 83, 70, and 97%, respectively. The average time of the procedure was 31 minutes. CONCLUSION: The C type hook was the most effective, and the new technique using the hook was more convenient and time-saving than the old technique using a nasal endoscopy.