| | The Evolution of Endonasal DacryocystorhinostomyAbstract Dacryocystorhinostomy is an important treatment in the relief of tearing. Through the years, there have been several advances in this procedure. Once performed only from an external approach, the advent of rigid endoscopes and endoscopic instrumentation has made the endonasal approach a reality. Advantages of the endonasal approach include lack of a cutaneous incision and excellent visualization of intranasal pathology, which is often the cause of dacryocystorhinostomy failure. Preoperative evaluation including a detailed medical history, physical examination with office endoscopy, and imaging, as well as postoperative care are important. Surgical technique with detailed knowledge of intranasal anatomy and meticulous attention to hemostasis are critical. Endonasal laser-assisted dacryocystorhinostomy is also performed today, and special preoperative considerations and key features of the lasers available are important in the selection of a laser for tissue or bone ablation during the procedure. Endoscopic conjunctivodacryocystorhinostomy is performed today, and given the critical nature of proper length and placement of the Jones tube intranasally, provides the significant advantage of intranasal visualization. Endoscopic dacryocystorhinostomy in children is also performed today; however, challenges such as small nasal anatomy and maintenance of the intranasal osteomy postoperatively in a child are significant issues.
The tearing patient is a challenge to the ophthalmologist. Hypersecretion, lacrimal pump dysfunction, and lacrimal outflow obstruction are all causes of tearing. With the advent of dacryocystorhinostomy (DCR), tearing secondary to nasolacrimal duct obstruction is a treatable condition with a high success rate of resolution.
History  External dcr The function of DCR is to divert lacrimal drainage into the nose through an osteomy at the level of the lacrimal bone. This procedure is performed either through an external or endonasal approach. The external approach is the most commonly used. External DCR, as originally described in 1904 by Toti,84 consisted of resecting the lacrimal sac mucosa, bone, and nasal mucosa through an external skin incision. This technique was modified by Dupuy-Dutemps and Bourguet,18 who introduced the concept of nasal and lacrimal mucosal flaps to create an epithelium-lined fistula. This procedure has largely been unchanged and remains the gold standard in the treatment of acquired nasolacrimal duct obstruction. Success rates of greater than 90% are common with this procedure. However, the cutaneous incision and disruption of the medial canthal ligaments with resultant lacrimal pump dysfunction have been cited as significant disadvantages.53, 96 Endonasal dcr Endonasal dacryocystorhinostomy was first proposed by Caldwell in 1893.10 Caldwell used an electric burr to create a middle meatal osteotomy in the area marked by a metal probe. This probe was passed through the nasolacrimal duct to identify the area of blockage. The technique was modified by West in 1914,92 who introduced the idea of a window osteotomy by removal of the lacrimal bone and the superior maxilla to access the nasolacrimal duct. However, the popularity of endonasal DCR did not increase until the 1970s and 1980s.39 Rice demonstrated in cadaver studies that endoscopy was a viable option in DCR.71 The first clinical study of endoscopic DCR was published by McDonough and Meiring in 1989.55 With the introduction of operating microscopes, rigid and semirigid nasal endoscopes, and fiberoptic delivery systems, physicians were able to evaluate intranasal anatomy. Rigid and semi-rigid endoscopes were used with increased frequency, particularly in otolaryngology with the advent of functional endoscopic sinus surgery. Prior to these advances, the endonasal technique was limited due to poor visualization and illumination in the superior nasal cavity and bleeding of the nasal mucosa. Endonasal laser assisted dcr An important discovery by Linberg et al in 1982 was that the healed ostium was only 2% the size of the initial surgical ostium.9, 48 They found that a small healed ostium could provide excellent functional results and that there was no statistical correlation between the size of the bony osteomy and the final size of the healed ostium. Armed with this information, physicians increased the use of endoscopy in lacrimal drainage surgery and investigated the use of lasers in DCR. In 1990, endonasal laser-assisted DCR was introduced by Massaro et al in a cadaveric study using the argon blue-green laser for bone removal.53 This laser had been used with success in other maxillofacial osteoablative procedures,45 and in a two-step technique (coagulation at low power, tissue vaporization at high power), they were able to create 4–6-mm ostia in the lacrimal fossa. Levin and Stormogipson47 introduced endocanalicular laser-assisted DCR in cadaveric specimens followed shortly thereafter by Silkiss et al78 and Michalos and Pearlman.60 In these studies, the Nd:YAG laser or a “thulium-doped or holmium-doped” version was employed. Gonnering et al introduced the first clinical trial of endonasal laser-assisted DCR, which used the carbon dioxide (CO2) and potassium titanyl phosphate (KTP)/neodynium-yttrium-garnet (YAG) laser for bone removal.22 Both of these laser modalities were previously approved for intranasal surgery.20 They reported success rates of 100%, yet at the time of reporting the follow-up period had not been completed. Disadvantages were that the CO2 delivery system was cumbersome, and the CO2 laser had poor coagulation properties. Woog et al detailed the use of the holmium:YAG laser in bone ablation.57, 96 They believed that the holmium:YAG successfully fulfilled the essential characteristics of endolaser DCR:20 efficient bone ablation, excellent hemostasis, minimal damage to surrounding structures, and ability to be delivered through a flexible fiberoptic delivery system. They asserted that its thermal vaporization provides hemostasis through coagulation, and the decrease in energy density with increased distance from the probe decreases the risk of collateral damage. The reported rate of long-term patency was 82%. The authors suggested reasons for the lower success rate included the steep learning curve of the procedure and decreased rate of bone removal with increased char production during the procedure. Javate et al introduced endoscopic DCR with a radiofrequency unit for incision of the nasal mucosa and bone which simultaneously cuts and coagulates with minimal heat damage.38 They also used a Kerrison rongeur to enlarge the bony osteomy, and mitomycin C and silicone stents to prevent closure of the ostium. Clinical studies of endocanalicular laser-assisted DCR by Pearlman and Michalos67 and Leib and Fay44 utilitized the Nd:YAG, reporting success rates of 91% and 84%, respectively. Familiarity with the Nd:YAG laser in bony ablation in sinus surgery, as well as excellent hemostasis in the contact mode are reasons that this type of laser is a popular choice.20 Advantages of the endocanalicular laser DCR procedure include direction of laser energy away from the globe, more familiar instrumentation and technique to the ophthalmologist, rapidity of procedure, use of local anesthestic, and less convalescence time.20 Anatomy Knowledge of the anatomy of the lacrimal drainage system is important prior to performing any lacrimal surgery procedure. The anatomical relationship between the lacrimal drainage system and the lateral nasal wall highlights the advantages of the endonasal procedure (Fig. 1). The lateral nasal wall is formed by turbinates, which are bony projections that are lined by mucus membrane. The meatus is the opening beneath and lateral to the corresponding turbinate. The important structures of the lateral nasal wall Fig. 2, Fig. 3, Fig. 4 in endoscopic DCR include the maxillary line, the middle turbinate, the middle meatus, the agger nasi, bulla ethmoidalis, and the uncinate process. The maxillary line is a ridge on the lateral nasal wall. This ridge lies anterior to the insertion of the middle turbinate (axilla).55 The maxillary line corresponds to the area slightly anterior to the junction of the frontal process of the maxilla and the lacrimal bone.8 There may be a bony dehiscence at the suture line located at this junction, which can be useful in accessing the lacrimal sac. The anterior lacrimal crest is formed by the frontal process of the maxilla and the posterior lacrimal crest is formed by the lacrimal bone. The lacrimal fossa is formed by the thicker frontal process of the maxilla and the thinner lacrimal bone. Part or all of the nasolacrimal sac and duct may be seen through the thin lacrimal bone, and this can be confirmed during probing.93 The middle turbinate is a part of the ethmoid bone. Part or all of the middle turbinate may be pneumatized (concha bullosa), which can make access to the lacrimal bone difficult. The agger nasi is a bony protrusion anterior to the insertion of the middle turbinate.12, 37 The ethmoidal air cells (also called agger nasi air cells) are present, and in some patients these air cells extend the entire length of the lacrimal sac fossa.54 The uncinate process is a bony plate with mucosal covering located anterior to the middle turbinate and is more prominent after middle turbinectomy. It is also a landmark for the lacrimal bone, which lies immediately anterior to it.69 The agger nasi and the uncinate process arise from the same fetal bony structure and in some adults may be indistinguishable.37 The bulla ethmoidalis is a rounded projection of the lateral wall that is beneath the middle turbinate.37 The middle meatus is the opening deep to the middle turbinate. This meatus is adjacent to the lacrimal sac fossa.54 The nasolacrimal sac is 10 mm in length and is located in the lacrimal fossa between the anterior and posterior crus of the medial canthal tendon. The nasolacrimal sac is anterior to the middle turbinate.55, 58, 81, 93, 97 Most authors state that the axilla of the middle turbinate (the anterior point of insertion of the middle turbinate to the lateral nasal wall) marks the superior point of the lacrimal sac in most patients.55, 58, 80 However, Wormald et al in his series of patients, found that a major portion of the lacrimal sac lies above the axilla of the middle turbinate.97 The nasolacrimal duct, a continuation of the lacrimal sac, travels laterally and posteriorly through the maxilla for 12 mm and terminates in the inferior meatus, just below the inferior turbinate of the nose.98 Preoperative Preparation Medical history Endonasal DCR is successful only if important preparative techniques are employed. Careful history with special attention to bleeding disorders or diseases that may require anticoagulation are important. A detailed medication history may elicit anticoagulants, and these drugs are discontinued if possible upon consultation with the patient's primary care physician. Coumadin should be discontinued 3 to 4 days prior to surgery, with heparinization stopped 6 hours prior to surgery. Aspirin and aspirin-containing products should be discontinued 2 weeks prior to surgery. Nonsteroidal antiinflammatory medications may be discontinued 3 days prior to surgery because the duration of action is shorter. Appropriate laboratory testing consisting of prothrombin (coumadin), partial thromboplastin (heparin), and bleeding time (aspirin and other nonsteroidal anti-inflammatory drugs) should be performed to assess the patient's coagulation status. Physical examination A detailed ophthalmologic examination with preoperative nasal endoscopy is important to assess the viability of an endonasal procedure. Anatomic hurdles in placement of instruments or intranasal visualization must be identified prior to surgery.54 Discoloration of the nasal mucosa may indicate an allergic rhinitis. This discoloration may be associated with hypertrophy of the middle turbinate. Pneumatization of the middle turbinate (concha bullosa) may cause narrowing of the middle meatus and limitation of visualization. Septal deviations can limit ease of instrumentation in the nose. Nasal polyps and intranasal neoplasms can block the middle meatus, making access difficult. These should be biopsied to evaluate for malignancy or inverted papilloma, a benign tumor that is locally invasive. Preoperative endoscopy is an important step in planning and aids in determining whether or not secondary procedures (e.g., septoplasty or middle turbinectomy) must be performed. Woog, Metson, and Puliafito found that the conversion rate to external DCR intraoperatively was 13%.96 Preoperative imaging Preoperative imaging may be considered in cases where there is a suspicion of lacrimal sac tumor or dacryolith. Dacryocystography is useful in evaluation of anatomy and surgical planning. Dynamic digital subtraction macrodacryocystography with unilateral or bilateral simultaneous injection is the current method of DCG.34, 63 This method relies on distention of the lacrimal system with rapid injection of low-viscosity contrast medium to assess lacrimal drainage flow and timing of flow.24 DCG with or without CT can also help determine the location and extent of blockage and identification of lacrimal sac masses and diverticula.17, 50 DCG can determine the patency of a bony osteum prior to endoscopic surgery for DCR failure.17 It also may be helpful in the determination of a successful outcome52 with localization of a dilated sac. CT is useful for determining abnormalities of the nasal cavity, sinuses, and lacrimal sac, particularly in patients with trauma, history or suspicion for tumor of the lacrimal system or sinuses, and previous facial or sinus surgery. Coronal CT images are helpful in patients with obstruction after sinus surgery. Intraoperative Management Hemostasis Attention to meticulous hemostasis is critically important in performing endonasal DCR. Minimal amounts of bleeding obscure visualization through the endoscope and increase the difficulty of this procedure. Hemostasis of the nasal mucosa can be achieved with placement of nasal packing soaked with decongestants such as 0.04% oxymetazoline hydrochloride or 4% cocaine and is important in maintaining excellent visibility throughout the surgical procedure. Oxymetazoline hydrochloride is effective as a vasoconstrictor, but unlike cocaine it has no anesthetic properties.12 Injection of the nasal mucosa anterior to the middle turbinate with 1% or 2% lidocaine (xylocaine) with 1:100,000 epinephrine is also important in hemostasis. Nasal decongestion Nasal decongestion is important to optimize visibility intranasally. Decongestants such as 0.04% oxymetazoline hydrochloride and 4% cocaine are commonly used. Oxymetazoline hydrochloride can be given both in spray form22 prior to sedation or as a solution impregnated in nasal packing. Anesthesia Attention to anesthesic options is also a key component in surgical preparation. Local or general anesthesia may be used, depending on the anxiety, cooperation, and general health of the patient. Two percent lidocaine with or without bupivicaine given as an infraorbital, anterior ethmoidal, and subcutaneous block is often effective as local anesthesia. Injection of the nasal mucosa with lidocaine and use of neurocottonoid patties soaked in 4% cocaine anesthetize the nasal mucosa as well as provide hemostasis. It is important to note that general anesthesia with common inhalation agents does cause vasodilation and increased bleeding of the surgical field.71 Halothane is contraindicated with cocaine use because both agents sensitize the myocardium.12 Special precautions with laser use An important precaution is avoidance of supplemental oxygen in the surgical field when performing a laser-assisted DCR with local anesthesia to avoid a potential fire.98 The operating room staff should wear protective eyewear during laser use. The patient's eyes and endotracheal tube should also be covered during the procedure,12 and suction should be available for removal of plume created by the laser, which could pose a biologic hazard.12, 42 Surgical technique Methods of visualization during endonasal DCR include loupes and headlight illumination, operating microscope, or endoscopy. Endoscopy with video monitoring is the preferred method for most surgeons because of superior visualization and magnification of the surgical site. Localization of the Lacrimal Sac Identification and localization of the lacrimal sac is the first important step. Some authors advocate placement of a retinal light pipe.98 A 20-gauge retinal light is placed through the canaliculus and advanced through the sac to the medial wall. The light from the light pipe marks the area of ostium placement. Other authors advocate placement of a Bowman lacrimal probe into the lacrimal sac to guide location of the ostium.12 Some instill 2% flourescein dye with Viscoat in the lacrimal sac for identification.43 A 0° or 30° Hopkins rigid endoscope attached to a camera is then placed to view the field. After proper decongestion and instillation of anesthetic, a sickle knife or Freer periosteal elevator is used to incise the nasal mucosa anterior to the middle turbinate. This incision is carried out vertically or curvilinear fashion down to the bone. Approximately 1–1.5 cm of nasal mucosa is removed with Blakesley or Takahashi forceps. Some physicians excise the middle turbinate to improve visualization of the lacrimal sac and prevention of postoperative synechiae and scarring.80 Others recommend turbinate infracture.7 Care must be taken because manipulation of the middle turbinate can cause significant bleeding and postoperative scarring. Formation of the Osteotomy Once the lacrimal fossa is exposed, the osteotomy is formed initially by fracturing the thin lacrimal bone using the probe of the light pipe or a hemostat (Fig. 5). Thus, the initial placement of the osteotomy is more inferior and posterior. Enlargement of the opening more anteriorly is performed using an otologic cutting drill with diamond burr,50, 96 forceps, currettes, or neurosurgical microrongeurs43, 50, 54 to remove the thicker bone of the maxilla. Placement of the osteomy is important. Osteotomies placed too high cause formation of lacrimal sump syndrome,61, 89 causing DCR failure. The lacrimal sump syndrome occurs when residual lacrimal sac is present, forming a blind pouch with collection of tears and causing recurrent dacryocystitis. Tearing in the setting of a patent system on irrigation and slightly delayed dye disappearance test postoperatively should alert the clinician to this entity. If a laser is used, its function is ablation of the mucosa and thinning of the bone.98 The four types of lasers (argon blue-green, potassium titanyl phosphate:yttrium aluminum garnet (KTP:YAG), holmium:yttrium aluminum garnet (Ho:YAG), carbon dioxide) in use today have three main properties: tissue coagulation, vaporization, and cutting. The KTP:Yag laser is able to coagulate blood vessels as well as cut, coagulate, and vaporize tissue. The Ho:YAG laser has the ability to ablate bone in addition to the above properties. The carbon dioxide laser has good cutting and vaporization properties but is poor at tissue coagulation. In addition, the CO2 laser must be used in a dry surgical field, because part of the laser energy is absorbed by fluid.12 The carbon dioxide laser, unlike the other lasers, is unavailable in a fiberoptic delivery system, which limits its use in the operating room setting. Char is the carbonization of tissue that occurs from overheating and can be prevented with appropriate laser energy levels.12 Char can be removed with use of dilute hydrogen peroxide. Osteotomy sizes of 5–6 mm are ideal in this setting.22, 53, 96 Incision/Removal of Lacrimal Sac Flaps Once the lacrimal sac mucosa is encountered after creation of the bony osteotomy, the lacrimal sac is tented into the surgical site either with a light pipe,96 lacrimal probe,8, 96 or lacrimal cannula.26 This prevents injury to the lateral wall of the lacrimal sac and surrounding orbital structures96 while the lacrimal sac is opened. Incision of the medial wall of the sac is performed with a sickle knife or 11-blade, and the mucosal opening enlarged with angled endoscopic or Takahashi forceps.8, 12 The mucosal opening should be 5–10 mm and the common internal punctum well visualized with the 0- or 30-degree endoscope. Simultaneous placement of the lacrimal probes through the superior and inferior canaliculi to identify the common entry point help to visualize and confirm the area of the common internal punctum.96 Specimens for biopsy can also be obtained during the mechanical removal of the lacrimal sac mucosa. Some authors use the laser for ablation of the lacrimal sac mucosa43, 50 or a radiofrequency unit; however, the ability to obtain a biopsy specimen is lost. Stent Material and Placement Once the ostium is formed, bicanalicular intubation with stents is placed. Absence of sutured flaps necessitates stent placement to prevent closure of the ostium. Most often these are silicone stents; however, some physicians use alternative stent material or no stents at all.87 Some physicians assert that silicone stents increase the risk of ostium closure by causing a granulomatous reaction.1, 3 Because of this possibility, some physicians advocate removal of silicone stents after 6 to 8 weeks.75, 96 The silicone stents may be secured to the lateral nasal wall with a nylon8 or polypropylene14, 74 suture. One author advocates preplacement of suture at three points prior to intubation.29 Red rubber catheters and C-flex lacrimal catheters were also used for stent material.23, 96 Double stents, silicone sleeves, gelfoam-thrombin stents, and silicone sponge implants have also been used to prevent osteomy closure.33, 46, 62, 73 Pharmacologic Wound Manipulation Many authors advocate the use of mitomycin-C to prevent osteotomy closure.76, 99 Mitomycin-C is an alkylating agent that inhibits fibroblast proliferation at the ostium site. Placement of this medication on a cotton-tip applicator at strengths of 0.3–0.5 mg/ml for 3 minutes potentially increases the chance of fistula patency;8 however, this has been disputed by some authors.99 Mitomycin has been used in glaucoma filtration surgery and ptergyium surgery with documented significant side effects, including hypotony-related maculopathy, wound leak, wound infection, scleral ulceration, and corneal epithelial defects and perforation.28, 77, 79 Camara et al, in their investigation of endonasal laser-assisted DCR and mitomycin-C, did not encounter any intranasal complications such as poor wound healing, mucosal necrosis, infection, or abnormal bleeding with intranasal application with mitomycin-C.11 Most physicians consider this medication in reoperations,21 and given the potential for significant ocular and intranasal complications, mitomycin-C is best used with caution in the setting of DCRs with multiple failures. This method and others are performed to avoid secondary intention healing because there is no substitute for direct anastomosis between the lacrimal sac and nasal mucosa. Intraoperative Nasal Packing Nasal packing is effective in hemostasis. There are several types which can be placed at the end of the operation if necessary. Some physicians advocate synthetic polyvinyl acetal sponges (Merocel Corp., Mystic, CT),8, 43 whereas others use gauze strips or finger cots with petroleum gel ointment. Prevention of adhesions and hemostasis are the advantages of the last technique. Gelfoam sponges have been shown to increase the risk of surgical failure secondary to their induced inflammatory response.27 Postoperative Care Postoperative care is important to maximize success rate of these surgical procedures (Table 1).50 If nasal packing is placed intraoperatively, it should be removed at the post-operative day-one visit.8 Systemic antibiotics are recommended for 7–10 days.8, 46, 81 Irrigation of the fistula with saline nasal spray and antibiotic-steroid eye drops are important. Some patients are given intranasal steroid spray after the first postoperative visit. Each postoperative visit may include debridement of crusting around ostium, lacrimal irrigation, and inspection of the surgical site with a speculum or nasal endoscopy. Special attention should be paid to early adhesions, granuloma formation, and position of the middle turbinate (if present). Postoperative care includes cleaning of the fistula site under endoscopic visualization and removal of the silicone tubing at 2–6 months.58 Patients should avoid heavy lifting, bending or straining, or nose blowing for the first week after the surgery.8 Complications Complications secondary to endoscopic DCR include bleeding from the nasal mucosa, ethmoid air cells, or nutrient vessels of the anterior lacrimal crest. Nasal packing, anesthetic injection with epinephrine, and gelfoam placement are helpful in resolution of bleeding. Orbital injury from posterior bone removal is also possible. CSF leak can occur with fractures of the ethmoid bone extending superiorly to the cribiform plate. This can occur secondary to bone removal by rongeurs in a torsion motion.49 Scarring of the osteomy site may occur because of granulomatous inflammatory reaction from silicone tubing, and adhesions from septum and middle turbinate.49, 70 Laser usage during this procedure can also cause thermal injury and charring of surrounding medial canthal, lacrimal, and canalicular tissue, and severe orbital edema.43 Stent displacement can also occur, with resulting punctal and canalicular erosion, and corneal abrasions. Stent displacement also increases the rate of DCR failure. Boush et al reported that primary endonasal DCR success rate of 81% with tube retention for 4 months and 22% without tube retention.7 Endoscopic versus External DCR Several reports have compared endoscopic and external DCR.5, 26 Most show that external DCR has a higher primary success rate. Hartikainen found that secondary success rate of both procedures was the same.26 Success rates with secondary revision have been reported as 80–95%.7, 43 Advantages of endoscopic DCR include lack of a cutaneous incision, direct access and visualization of the osteotomy site, and avoidance of disruption of the medial canthus and lacrimal pump function. Disadvantages include limited visualization of the nasolacrimal sac and duct to inspect for pathology, and the need for meticulous hemostasis. This technique also poses a significant technical challenge in patients with facial trauma.38, 95, 98 The intranasal anatomy and lack of familiarity with the surgical instruments pose a significant challenge in learning the surgical technique for most ophthalmologists. The equipment required and skill of ancillary personnel may incur a significant cost. The advantages of external DCR include ease of inspection of the lacrimal sac for pathology (such as tumors and dacryoliths), and ease of suturing mucosal flaps. Disadvantages include placement of a cutaneous incision, increased bleeding, and prolonged operating times. Some authors5 assert that hemostasis is comparable83 in both procedures and that most patients with bleeding postoperatively have an underlying disorder. Bartley also asserts that the cutaneous incision is not a cosmetic blemish if placed in skin tension lines and that both procedures performed in experienced hands require comparable surgical time.5 Although the primary success rate is less than external DCR,43, 96 secondary success rates of endoscopic DCR approach are comparable.26 Endoscopic Revision of Failed DCR Endoscopic DCR has been shown to be a valuable tool in the revision of external and endoscopic DCR. This idea was initially reported by Jones, in which the procedure consisted of mucosal elevation and tissue excision.40 Allen et al described using the nasal endoscope to visualize intranasal anatomy and evaluate the etiology of DCR failure.16 Primary failure rates of external DCR have been shown to be less than 10%.2, 35, 36, 90 Primary failure rates of endoscopic DCR range from 10–33%.26, 99 Failure of DCR is secondary to common canalicular obstructions,56 intranasal abnormalities,36, 66, 82 adhesions to the nasal septum, and lacrimal fossa pathology. Welham and Henderson,91 Allen and Berlin,1 and Steadman81 state that soft tissue obstruction of the rhinostomy site is the most common cause of DCR failure. Synechiae between the rhinostomy site and the septum or middle turbinate occur secondary to posterior placement of the osteomy site. A granulomatous membrane can form, often in the setting of silicone stent placement, causing stent failure.1 Fibrosis of the osteomy can also occur. Because of the multitude of potential intranasal abnormalities,66 endoscopic revision of failed DCR procedures is a good choice in evaluation of intranasal anatomy and surgical management. Endoscopic revision has several advantages including lack of a cutaneous incision, direct visualization of the lacrimal sac, and assessment of intranasal pathology. It can be utilized as an outpatient procedure, and is safely performed under local anesthetic. Angled instruments developed for endoscopic sinus surgery allow for direct visualization and surgical enlargement and positioning of the ostium, without damage to surrounding tissues. In addition, an assortment of secondary procedures can be performed at the time of endoscopic revision.58 Procedures such as middle turbinectomy, anterior and posterior ethmoidectomy, septoplasty, and maxillary antrostomy are utilized to decrease postoperative adhesions, enhance surgical exposure of the lacrimal sac, and remove accompanying sinus disease. Obstructive intranasal pathologies, such as polypoidal disease, middle turbinate hypertrophy, large agger nasi cells, and deviated septa, are easily treated under direct visualization. Endoscopic revisions (as well as primary endonasal DCR procedures) typically do not involve suturing of mucosal flaps, and there has been some controversy as to whether or not this decreases the success rate.41, 58, 72 However, Becker reported performing external DCR without flaps and achieved a success rate of 92.5%,6 suggesting that flaps are not necessarily essential for effective DCR procedures. The disadvantages of endonasal DCR (particularly in revision procedures) include need for meticulous hemostasis58 and limited exposure for inspection of malignancies or other abnormalities. Endonasal DCR may be suboptimal in obtaining biopsy material, but some physicians dispute this.86, 96 Woog et al used angled endoscopic forceps to biopsy the lacrimal sac mucosa in their series of patients undergoing the procedure. There is also difficulty in bone removal in endonasal DCR, and the use of lasers and drills are associated with thermal damage that can cause scarring and increase the chance of DCR failure.13, 80, 96 Some physicians advocated performing endoscopic DCR only in the setting of revision, when the obstruction of the osteomy is secondary to a soft tissue, rather than bony abnormality.19 Success rates of endoscopic DCR for revision cases has been 83%,7, 19 75%,58 and 80%.52 Lacrimal sac cicatrization and intranasal synechia formation are associated with lower success rates.52 Endoscopic DCR does facilitate evaluation and management of the surgical ostium and any associated intranasal pathology, with an additional cosmetic benefit. Endoscopic Conjunctivodacryocystorhinostomy Endoscopic Conjunctivodacryocystorhinostomy (CDCR) with Jones tube placement has been described. Most reports of CDCR have described the external approach, whereby a medial canthal incision is utilized to create the bony osteotomy and position the pyrex tube. CDCR is performed as a primary procedure after failed DCR for canalicular stenosis or obstruction16, 40, 90 or to alleviate severe lacrimal pump dysfunction.16 Placement of a Jones tube bypasses the lacrimal system and creates a new outflow channel. Endoscopic visualization is critical in the placement of the Jones tube. It allows the surgeon excellent intranasal visualization to assess the proper length and positioning of the tube. This is important to facilitate drainage and decrease the potential for trauma to the middle turbinate and septum. The Jones tube is placed in the tear lake next to the caruncle or lower fornix. The tube is then positioned intranasally in the middle meatus after the osteomy is made. Under direct endoscopic visualization, a metal trochar or lacrimal probe with a catheter is passed from the medial fornix in the medial canthus through the thin lacrimal bone inferiorly into the middle meatus. The trochar serves as a marker for placement of the initial incision in the nasal mucosa and for bone removal. After the opening around the trochar is enlarged, the trochar is removed and the Jones tube placed. Assessment of tear drainage from the tube with irrigation is then easily performed with nasal endoscopy. The Jones tube is secured into position with a suture. Postoperative complications include tube dislodgement and migration, and intranasal trauma secondary to tube displacement. Trotter and Meyer85 evaluated the external CDCR vs endoscopic CDCR in 10 patients with canalicular stenosis. They looked at surgical times, estimated blood loss, postoperative adjustment, and rate of reoperation. They found that the blood loss and surgical time were comparable in both procedures, with endoscopic CDCR having slightly less OR time and blood loss. The success rate for both procedures was the same (100%). The advantages of endoscopic CDCR were the same as those cited for DCR: lack of cutaneous scar, less OR time, less blood loss. The disadvantages included higher equipment cost and increased time and effort in learning technique. The endoscopic approach is also easier in the setting of a revision procedure, given that the bony osteotomy has already been formed and the assessment of intranasal anatomy at the rhinostomy site is excellent with the endoscope. Given the critical nature of accurate intranasal Jones tube placement to the success of a primary or revision CDCR procedure, the endoscopic method provides the distinct advantage to the external approach of superior intranasal visualization. Endoscopic DCR in Children Endoscopic DCR has been reported in small series in children. Although congenital nasolacrimal duct obstruction occurs in 6%–20% of all infants,51, 68 the rate of spontaneous resolution is 85–96% within the first year.76, 78 Ninety-five percent of children who do not resolve spontaneously improve with nasolacrimal duct probing.88 However, the success of probing decreases with increasing age of the child. This small percentage of patients (usually older than 12 months) who are unresponsive to probing is the group who are candidates for external or endoscopic DCR. Children who have mucoceles or recurrent dacryocystitis neither resolve spontaneously nor respond to nasolacrimal duct probing and are also candidates for DCR. The success rate of external DCR in children ranges from 83% to 96%,25, 64, 88 with higher success rates in patients with congenital anomalies and nasolacrimal duct obstruction without canalicular disease. Cunningham and Woog15 reported on 4 children who underwent primary or revision endoscopic DCR. All of the patients had successful clinical outcomes after follow-up of 10–24 months. They state that endoscopic DCR is technically more difficult given the smaller size of the child's nasal passage but that combined otolaryngologic and ophthalmologic expertise along with proper otolarynogologic equipment increase the safety and efficacy of this procedure. Wong et al94 also reported cases that underwent primary endoscopic DCR with successful outcomes. General anesthesia is required, and the 4.0- and 2.7-mm endoscopic telescopes are used because of better illumination, wider field of vision, and better accommodation of the narrow passages of the children. Meticulous hemostasis is important, particularly because of the small surgical site and because of the smaller total blood volume in a child. Identification of the lacrimal sac is also important, as it is in adult cases, and light pipes and probes are used. Additional procedures such as anterior ethmoidectomy and maxillary antrostomy were performed to enhance exposure of the surgical site.15, 94 Removal of bone in the pediatric nares can be problematic, with posterior bone removal easier but with increased potential for orbital injury. Otologic drills,15 hand trephines,30 hemostats, and microrongeurs59 are used to create a large osteomy. Bicanalicular intubation with silicone stents are placed and left in position for several months.32, 65 Postoperative management can be difficult, and general anesthesia may be required to perform inspection, irrigation, and debridement of the osteomy site. Complications secondary to stent intubation are common15, 88 and include stent displacement (particularly during play) and granuloma formation. Some physicians advocate limited patching at night postoperatively to avoid stent displacement,88 whereas others propose intraoperative measures, such as intranasal fixation of the stent31 or use of lacrimal intubation sets with sutures that can be placed exteriorly on the skin.4 Intranasal steroids are a possible remedy for granuloma formation in older children but may not be feasible in small children because of dosing issues and compliance.15 Scarring and adhesions do occur in pediatric DCR, and several authors suggest intranasal revisions in children after external DCR.32, 59 Authors conclude that endoscopic DCR is feasible in children despite increased technical challenge, although clinical studies are early and limited to date. Conclusion The evolution of endonasal DCR continues. As economic constraints increase and patient expectations remain high, this procedure must constantly be refined to approach the safety and efficacy of external DCR. Physician preference, patient selection, availability of equipment, and monetary constraints will determine the choice as to whether or not to perform surgery to relieve outflow obstruction externally or endoscopically, with or without lasers, in adults or children. Consultation with otolarynoglogists can be useful in patients with pre-existing nasal or sinus disease, previous facial or sinus surgery, facial trauma, or congenital midface abnormalities. The ophthalmologist and the patient together must discuss and evaluate the options to accomplish the goals of the procedure, the relief of tearing and infection. Method of Literature Search The database used in this search was Medline. The years searched were from 1970 until 2001. A few select articles published before 1970 were included for historical purposes, but the review is based mainly on articles published in the last three decades. The search words used included dacryocystorhinostomy, endoscopic dacryocystorhinostomy, lacrimal, tearing, laser-assisted dacryocystorhinostomy, endoscopic conjunctivodacryocystorhinostomy, pediatric dacryocystorhinostomy, congenital nasolacrimal duct obstruction, acquired nasolacrimal duct obstruction. All articles judged to be of clinical importance were included as well as additional references of key articles. These articles were chosen to provide a clear, comprehensive view of critical aspects and technique of endoscopic dacryocystorhinostomy, with special emphasis on anatomy, incorporation of laser devices, use in children, and postoperative care. The articles included also were used to delineate the historical context of this procedure in the evolution of lacrimal drainage surgery. Non-peer reviewed articles and non-English abstracts were excluded. Acknowledgements The authors would like to thank Scott Turley for his help in preparing the manuscript and Bob Galla for his illustrations. The authors reported no proprietary or commercial interest in any product mentioned or concept discussed in this article. References 1.
1
Allen K, Berlin AJ.
Dacryocystorhinostomy failure (association with nasolacrimal silicone intubation).
Ophthalmic Surg. 1989;20:486–489. 2.
2
Allen KM, Berlin AJ, Levine HL.
Intranasal endoscopic analysis of dacrocystorhinostomy failure.
Ophthal Plast Reconstr Surg. 1988;4:143–145. MEDLINE 3.
3
Anderson RL, Edwards JJ.
Indications, complications and results with silicone stents.
Ophthalmology. 1979;86:1474–1487. Abstract 4.
4
Arnold RW.
Bilateral monocanalicular silicone loop (predictable home removal of nasolacrimal stents).
J Pediatr Ophthalmol Strabismus. 1995;32:200–201. MEDLINE 5.
5
Bartley GB.
The pros and cons of laser dacryocystorhinostomy.
Am J Ophthalmol. 1994;117:103–106. MEDLINE 6.
6
Becker BB, Berry FD, Koller H.
Balloon catheter dilatation for treatment of congenital nasolacrimal duct obstruction.
Am J Ophthalmol. 1996;121:304–309. MEDLINE 7.
7
Boush GA, Lemke BN, Dortzbach RK.
Results of endonasal laser-assisted dacryocystorhinostomy.
Ophthalmology. 1994;101:955–959. Abstract 8.
8
Buerger DE, Woog JJ.
Expert commentary-endonasal and revisional dacryocystorhinostomy.
In:
Mauriello JA editors. Unfavorable Results of Eyelid and Lacrimal Surgery (Prevention and Management). Boston: Butterworth Heinemann; 2000;p. 558–560. 9.
9
Bumsted RM, Linberg JV, Anderson RL, Barreras R.
External dacryocystorhinostomy. A prospective study comparing the size of the operative and healed ostium.
Arch Otolaryngol. 1982;108:407–410. MEDLINE 10.
10
Caldwell GW.
Two new operations for obstruction of the nasal duct with preservation of the canaliculi.
Am J Ophthalmol. 1893;10:189. 11.
11
Camara JG, Bengzon AU, Henson RD.
The safety and efficacy of mitomycin C in endonasal endoscopic laser-assisted dacryocystorhinostomy.
Ophthal Plast Reconstr Surg. 2000;16:114–118. MEDLINE |
CrossRef
12.
12
Carter KD, Nerad JA.
Primary acquired nasolacrimal duct obstruction.
In:
Bosniak S editors. Principles and Practice of Ophthalmic Plastic and Reconstructive Surgery. Philadelphia: WB Saunders; 1996;p. 784–796. 13.
13
Christenbury JD.
Translacrimal laser dacryocystorhinostomy.
Arch Ophthalmol. 1992;110:170;
. MEDLINE 14.
14
Christmann LM.
Crawford tubes—a technique to avoid dislocation.
J Pediatr Ophthalmol Strabismus. 1991;28:290–291. MEDLINE 15.
15
Cunningham MJ, Woog JJ.
Endonasal endoscopic dacryocystorhinostomy in children.
Arch Otolaryngol Head Neck Surg. 1998;124:328–333. MEDLINE 16.
16
Doucet TW, Hurwitz JJ.
Canaliculodacryocystorhinostomy in the management of unsuccessful lacrimal surgery.
Arch Ophthalmol. 1982;100:619–621. MEDLINE 17.
17
Dudley DF, Orcutt JC, Hillel AD.
Expert commentary—endonasal and revisional dacryocystorhinostomy.
In:
Mauriello JA editors. Unfavorable Results of Eyelid and Lacrimal Surgery (Prevention and Management). Boston: Butterworth Heinemann; 2000;p. 561–565. 18.
18
Dupuy-Dutemps MM, Bourguet ET.
Note preliminaire sur un proded de daryocystorhinostomie.
Ann D'Ocul (Paris). 1920;157:1445–1447. 19.
19
El-Guindy A, Dorgham A, Ghoraba M.
Endoscopic revision surgery for recurrent epiphora occurring after external dacryocystorhinostomy.
Ann Otol Rhinol Laryngol. 2000;109:425–430. MEDLINE 20.
20
Fay AM, Michalos P, Rubin PA.
Endocanalicular Nd (YAG laser dacryocystorhinostomy).
Int Ophthalmol Clin. 1999;39:177–184. MEDLINE |
CrossRef
21.
21
Goldberg RA.
Expert commentary—Standard endonasal dacryocystorhinostomy.
In:
Mauriello JA editors. Unfavorable Results of Eyelid and Lacrimal Surgery (Prevention and Management). Boston: Butterworth Heinemann; 2000;p. 535–536. 22.
22
Gonnering RS, Lyon DB, Fisher JC.
Endoscopic laser-assisted lacrimal surgery.
Am J Ophthalmol. 1991;111:152–157. MEDLINE 23.
23
Griffiths JD.
Nasal catheter use in dacryocystorhinostomy.
Ophthal Plast Reconstr Surg. 1991;7:177–186. MEDLINE 24.
24
Guzek JP, Ching AS, Hoang TA, et al.
Clinical and radiologic lacrimal testing in patients with epiphora.
Ophthalmology. 1997;104:1875–1881. Abstract 25.
25
Hakin KN, Sullivan TJ, Sharma A, Welham RA.
Paediatric dacryocystorhinostomy.
Aust NZ J Ophthalmol. 1994;22:231–235. 26.
26
Hartikainen J, Antila J, Varpula M, et al.
Prospective randomized comparison of endonasal endoscopic dacryocystorhinostomy and external dacryocystorhinostomy.
Laryngoscope. 1998;108:1861–1866.
CrossRef
27.
27
Hawes MJ.
Gelfoam dacryocystorhinostomy stent (one cause of surgical failure?).
Ophthalmic Surg. 1988;19:824–825. 28.
28
Hayasaka S, Noda S, Yamamoto Y, Setogawa T.
Postoperative instillation of mitomycin C in the treatment of recurrent pterygium.
Ophthalmic Surg. 1989;20:580–583. 29.
29
Hedges CC.
Lacrimal intubation stay suture.
Ophthalmic Surg. 1989;20:672–673. 30.
30
Heher KL, Katowitz JA.
Expert commentary—Pediatric dacryocystorhinostomy.
In:
Mauriello JA editors. Unfavorable Results of Eyelid and Lacrimal Surgery (Prevention and Management). Boston: Butterworth Heinemann; 2000;. 31.
31
Hunter LR.
Crawford tubes (with suture) secured with absorbable suture.
J Pediatr Ophthalmol Strabismus. 1995;32:197–199. MEDLINE 32.
32
Hunts JH, Patrinely JR, Anderson RL.
Pediatric dacryocystorhinostomy.
In:
Mauriello JA editors. Unfavorable Results of Eyelid and Lacrimal Surgery (Prevention and Management). Boston: Butterworth Heinemann; 2000;p. 461–469. 33.
33
Hurwitz JJ, Archer KF, Gruss JS.
Double stent intubations in difficult post-traumatic dacryocystorhinostomy.
Ophthalmic Surg. 1988;19:33–36. 34.
34
Hurwitz JJ, Kassel EE.
Dacryocystography.
In:
Hurwitz JJ editors. The Lacrimal System. Philadelphia: Lippincott-Raven; 1996;p. 63–72. 35.
35
Hurwitz JJ, Rutherford S.
Computerized survey of lacrimal surgery patients.
Ophthalmology. 1986;93:14–19. Abstract 36.
36
Hurwitz JJ.
Teflon tubes for stenting and bypassing the lacrimal drainage pathways.
Ophthalmic Surg. 1989;20:855–859. 37.
37
Janfaza P, Montgomery WW, Salman SD.
Nasal cavities and paranasal sinuses.
In:
Janfaza P, Nadol J, Galla R, et al. editor. Surgical Anatomy of the Head and Neck. Lippincott-Williams and Wilkins: Philadelphia; 2001;p. 272–285. 38.
38
Javate RM, Campomanes BS, Co ND, et al.
The endoscope and the radiofrequency unit in DCR surgery.
Ophthal Plast Reconstr Surg. 1995;11:54–58. MEDLINE 39.
39
Jokinen K, Karja J.
Endonasal dacryocystorhinostomy.
Arch Otolaryngol. 1974;100:41–44. MEDLINE 40.
40
Jones LT.
The cure of epiphora due to canalicular disorders, trauma, and surgical failures of the lacrimal passages.
Trans Am Acad Ophthalmol Otolarngol. 1975;62:506–524. 41.
41
Kinoshian HJ.
A new technique for dacryocystorhinostomy.
Arch Ophthalmol. 1963;70:33–37. MEDLINE 42.
42
Kokosa JM, Eugene J.
Chemical composition of laser-tissue interaction smoke plume.
J Laser Appl. 1989;1:59–63. 43.
43
Kong YT, Kim TI, Kong BW.
A report of 131 cases of endoscopic laser lacrimal surgery.
Ophthalmology. 1994;101:1793–1800. Abstract 44.
44
Leib ML, Fay AM: Trancanalicular endonasal laser assisted dacryocystorhinostomy [abstract]. Presented at the American Society of Ophthalmic Plastic and Reconstructive Surgeons, 1997, San Francisco, CA 45.
45
Lenz H, Eichler J, Schafer G, et al.
Production of a nasoantral window with an Ar+-laser.
J Maxillofac Surg. 1977;5:314–317. MEDLINE |
CrossRef
46.
46
Leone CR.
Gelfoam-thrombin dacryocystorhinostomy stent.
Am J Ophthalmol. 1982;94:412–413. MEDLINE 47.
47
Levin PS, StormoGipson DJ.
Endocanalicular laser-assisted dacryocystorhinostomy. An anatomic study.
Arch Ophthalmol. 1992;110:1488–1490. MEDLINE 48.
48
Linberg JV, Anderson RL, Bumsted RM, Barreras R.
Study of intranasal ostium external dacryocystorhinostomy.
Arch Ophthalmol. 1982;100:1758–1762. MEDLINE 49.
49
Linberg JV.
Expert commentary-Standard endonasal dacryocystorhinostomy.
In:
Mauriello JA editors. Unfavorable Results of Eyelid and Lacrimal Surgery (Prevention and Management). Boston: Butterworth Heinemann; 2000;p. 531–533. 50.
50
Lyon DB.
Endonasal and revisional dacryocystorhinostomy.
In:
Mauriello JA editors. Unfavorable Results of Eyelid and Lacrimal Surgery (Prevention and Management). Boston: Butterworth Heinemann; 2000;p. 551–557. 51.
51
MacEwen CJ, Young JD.
Epiphora during the first year of life.
Eye. 1991;5:596–600. 52.
52
Mannor GE, Millman AL.
The prognostic value of preoperative dacryocystography in endoscopic intranasal dacryocystorhinostomy.
Am J Ophthalmol. 1992;113:134–137. MEDLINE 53.
53
Massaro BM, Gonnering RS, Harris GJ.
Endonasal laser dacryocystorhinostomy. A new approach to nasolacrimal duct obstruction.
Arch Ophthalmol. 1990;108:1172–1176. MEDLINE 54.
54
Mauriello JA, Rosen A.
Surgical anatomy of the lacrimal drainage system.
In:
Mauriello JA editors. Unfavorable Results of Eyelid and Lacrimal Surgery (Prevention and Management). Boston: Butterworth Heinemann; 2000;p. 361–380. 55.
55
McDonogh M, Meiring JH.
Endoscopic transnasal dacryocystorhinostomy.
J Laryngol Otol. 1989;103:585–587. MEDLINE 56.
56
McLachlan DL, Shannon GM, Flanagan JC.
Results of dacryocystorhinostomy (analysis of the reoperations).
Ophthalmic Surg. 1980;11:427–430. 57.
57
Metson R, Woog JJ, Puliafito CA.
Endoscopic laser dacryocystorhinostomy.
Laryngoscope. 1994;104:269–274. 58.
58
Metson R.
Endoscopic surgery for lacrimal obstruction.
Otolaryngol Head Neck Surg. 1991;104:473–479. MEDLINE 59.
59
Meyer DR.
Expert commentary—Pediatric dacryocystorhinostomy.
In:
Mauriello JA editors. Unfavorable Results of Eyelid and Lacrimal Surgery (Prevention and Management). Boston: Butterworth Heinemann; 2000;. 60.
60
Michalos P, Pearlman SJ, Avila EN, Newton JC.
Hemispheric tip contact Nd:YAG translacrimal-nasal dacryocystorhinostomy.
Ocul Surg News. 1995;13:40. 61.
61
Migliori ME.
Endoscopic evaluation and management of the lacrimal sump syndrome.
Ophthal Plast Reconstr Surg. 1997;13:281–284. MEDLINE 62.
62
Mirabile TJ, Tucker C.
Dacryocystorhinostomy with silicone sponge.
Arch Ophthalmol. 1965;74:235–236. MEDLINE 63.
63
Nixon J, Birchall IW, Virjee J.
The role of dacryocystography in the management of patients with epiphora.
Br J Radiol. 1990;63:337–339. MEDLINE |
CrossRef
64.
64
Nowinski TS, Flanagan JC, Mauriello J.
Pediatric dacryocystorhinostomy.
Arch Ophthalmol. 1985;103:1226–1228. MEDLINE 65.
65
Nowinski TS.
Expert commentary—Pediatric dacryocystorhinostomy.
In:
Mauriello JA editors. Unfavorable Results of Eyelid and Lacrimal Surgery (Prevention and Management). Boston: Butterworth Heinemann; 2000;. 66.
66
Paulsen FP, Thale AB, Maune S, Tillmann BN.
New insights into the pathophysiology of primary acquired dacryostenosis.
Ophthalmology. 2001;108:2329–2336. Abstract | Full Text |
Full-Text PDF (421 KB)
|
CrossRef
67.
67
Pearlman SJ, Michalos P, Leib ML, Moazed KT.
Translacrimal transnasal laser-assisted dacryocystorhinostomy.
Laryngoscope. 1997;107:1362–1365.
CrossRef
68.
68
Petersen RA, Robb RM.
The natural course of congenital obstruction of the nasolacrimal duct.
J Pediatr Ophthalmol Strabismus. 1988;15:246–250. MEDLINE 69.
69
Raut VV, Yung MW, Logan BM.
Endoscopic dacryocystorhinostomy (anatomical approach).
Rev Laryngol Otol Rhinol (Bord). 2000;121:53–55. MEDLINE 70.
70
Rebeiz EE, Shapshay SM, Bowlds JH, Pankratov MM.
Anatomic guidelines for dacryocystorhinostomy.
Laryngoscope. 1992;102:1181–1184.
CrossRef
71.
71
Rice DH.
Endoscopic intranasal dacryocystorhinostomy. A cadaver study.
Am J Rhinol. 1988;2:127.
CrossRef
72.
72
Romanes GJ.
Dacryocystorhinostomy (clinical report of fifty cases).
Br J Ophthalmol. 1955;39:237–240. MEDLINE |
CrossRef
73.
73
Rosen N, Sharir M, Moverman DC, Rosner M.
Dacryocystorhinostomy with silicone tubes (evaluation of 253 cases).
Ophthalmic Surg. 1989;20:115–119. 74.
74
Rutherford S, Crawford JS, Hurwitz JJ.
Silicone tubing used in intubating the lacrimal system. Joining the ends for easy removal.
Ophthalmology. 1984;91:963–965. Abstract 75.
75
Seiff SR, Carter SR.
Expert commentary—Standard endonasal dacryocystorhinostomy.
In:
Mauriello JA editors. Unfavorable Results of Eyelid and Lacrimal Surgery (Prevention and Management). Boston: Butterworth Heinemann; 2000;p. 533–534. 76.
76
Seppa H, Grenman R, Hartikainen J.
Endonasal CO2-Nd:YAG laser dacryocystorhinostomy.
Acta Ophthalmol (Copenh). 1994;72:703–706. 77.
77
Shields MB, Scroggs MW, Sloop CM, Simmons RB.
Clinical and histopathologic observations concerning hypotony after trabeculectomy with adjunctive mitomycin C.
Am J Ophthalmol. 1993;116:673–683. MEDLINE 78.
78
Silkiss RZ, Axelrod RN, Iwach AG, et al.
Transcanalicular THC:YAG dacryocystorhinostomy.
Ophthalmic Surg. 1992;23:351–353. 79.
79
Skuta GL, Beeson CC, Higginbotham EJ, et al.
Intraoperative mitomycin versus postoperative 5-fluorouracil in high- risk glaucoma filtering surgery.
Ophthalmology. 1992;99:438–444. Abstract 80.
80
Sprekelsen MB, Barberan MT.
Endoscopic dacryocystorhinostomy (surgical technique and results).
Laryngoscope. 1996;106:187–189.
CrossRef
81.
81
Steadman MG.
Transnasal dacryocystorhinostomy.
Otolaryngol Clin North Am. 1985;18:107–111. MEDLINE 82.
82
Sternberg I, Levine MR.
Ethmoidal sinus osteoma—a primary cause of nasolacrimal obstruction and dacryocystorhinostomy failure.
Ophthalmic Surg. 1984;15:295–297. 83.
83
Sweet RM, Hofmann RF.
Surgical considerations for dacryocystorhinostomy with special emphasis on hemostatic techniques.
Ophthalmic Surg. 1983;14:317–321. 84.
84
Toti A.
Nuovo metodo conservatore dicura radicale delle suppurazioni croniche del sacco lacrimale (dacriocistorinostomia).
Clin Mod Firenze. 1904;10:385. 85.
85
Trotter WL, Meyer DR.
Endoscopic conjunctivodacryocystorhinostomy with Jones tube placement.
Ophthalmology. 2000;107:1206–1209. Abstract | Full Text |
Full-Text PDF (136 KB)
|
CrossRef
86.
86
Tucker N, Chow D, Stockl F, et al.
Clinically suspected primary acquired nasolacrimal duct obstruction (clinicopathologic review of 150 patients).
Ophthalmology. 1997;104:1882–1886. Abstract 87.
87
Unlu HH, Ozturk F, Mutlu C, et al.
Endoscopic dacryocystorhinostomy without stents.
Auris Nasus Larynx. 2000;27:65–71. Abstract | Full Text |
Full-Text PDF (1019 KB)
|
CrossRef
88.
88
Welham RA, Hughes SM.
Lacrimal surgery in children.
Am J Ophthalmol. 1985;99:27–34. MEDLINE 89.
89
Welham RA, Wulc AE.
Management of unsuccessful lacrimal surgery.
Br J Ophthalmol. 1987;71:152–157. MEDLINE |
CrossRef
90.
90
Welham RA, Guthoff R.
The Lester-Jones tube (a 15-year follow-up).
Graefes Arch Clin Exp Ophthalmol. 1985;223:106–108.
CrossRef
91.
91
Welham RA, Henderson PH.
Results of dacryocystorhinostomy analysis of causes for failure.
Trans Ophthalmol Soc UK. 1973;93:601–609. MEDLINE 92.
92
West J.
A window resection of the nasal duct in cases of stenosis.
Trans Am Ophthalmol Soc. 1995;12:659. 93.
93
Whittet HB, Shun-Shin GA, Awdry P.
Functional endoscopic transnasal dacryocystorhinostomy.
Eye. 1993;7:545–549. 94.
94
Wong JF, Woog JJ, Cunningham MJ, et al.
A multidisciplinary approach to atypical lacrimal obstruction in childhood.
Ophthal Plast Reconstr Surg. 1999;15:293–298. MEDLINE 95.
95
Woog JJ, Kennedy RH, Custer PL, et al.
Endonasal dacryocystorhinostomy (a report by the American Academy of Ophthalmology).
Ophthalmology. 2001;108:2369–2377. Abstract | Full Text |
Full-Text PDF (104 KB)
|
CrossRef
96.
96
Woog JJ, Metson R, Puliafito CA.
Holmium:YAG endonasal laser dacryocystorhinostomy.
Am J Ophthalmol. 1993;116:1–10. MEDLINE 97.
97
Wormald PJ, Kew J, Van Hasselt A.
Intranasal anatomy of the nasolacrimal sac in endoscopic dacryocystorhinostomy.
Otolaryngol Head Neck Surg. 2000;123:307–310. Abstract | Full Text |
Full-Text PDF (75 KB)
|
CrossRef
98.
98
Yeatts RP.
Lacrimal drainage system surgery.
In:
Albert DM, Jakobiec FA editor. Principles and Practice of Ophthalmology. Philadelphia: WB Saunders; 1999;p. 3555–3571. 99.
99
Zilelioglu G, Ugurbas SH, Anadolu Y, et al.
Adjunctive use of mitomycin C on endoscopic lacrimal surgery.
Br J Ophthalmol. 1998;82:63–66. MEDLINE |
CrossRef
1 Ophthalmic Plastic, Orbital, Reconstructive, and Cosmetic Surgery, Department of Ophthalmology, Boston, MA, USA 2 Department of Otology and Laryngology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA, USA  Reprint address: Peter A.D. Rubin, MD, FACS, Massachusetts Eye and Ear Infirmary, 243 Charles St., Boston, MA, USA 02114
PII: S0039-6257(02)00397-1 © 2003 Elsevier Science Inc. All rights reserved. | |
|
FULL TEXT00397-1/journalimage?img=PIIS0039625702003971.gr1.lrg.gif&fig=FIG1&kwhquery=&issn=0039-6257&ishighres=false&allhighres=false&free=yes','journalimage');)
00397-1/journalimage?img=PIIS0039625702003971.gr2.lrg.gif&fig=FIG2&kwhquery=&issn=0039-6257&ishighres=false&allhighres=false&free=yes','journalimage');)
00397-1/journalimage?img=PIIS0039625702003971.gr3.lrg.gif&fig=FIG3&kwhquery=&issn=0039-6257&ishighres=false&allhighres=false&free=yes','journalimage');)
00397-1/journalimage?img=PIIS0039625702003971.gr4.lrg.gif&fig=FIG4&kwhquery=&issn=0039-6257&ishighres=false&allhighres=false&free=yes','journalimage');)
00397-1/journalimage?img=PIIS0039625702003971.gr5.lrg.gif&fig=FIG5&kwhquery=&issn=0039-6257&ishighres=false&allhighres=false&free=yes','journalimage');)
