Conjunctivodacryocystorhinostomy (CDCR) with the insertion of a bypass tube (Table 12.1) is a procedure in which a new lacrimal route from the conjunctival sac into the nasal cavity is created and a drainage tube is inserted between the inner canthus and the nasal cavity (Fig. 12.1). The tube in place is considered a life-long prosthesis. The procedure is mostly indicated if the upper and lower ipsilateral canaliculi are completely obstructed [11, 23]. The success rate of the procedure varies from 80 to 90% [24].

Fig. 12.1. Total lower and upper canalicular obstructions with Jones tube insertion. (From [14])

Canalicular Picture

Fig. 12.1. Total lower and upper canalicular obstructions with Jones tube insertion. (From [14])

The canalicular obstructions, especially a proximal canalicular obstruction, represent a problematic and therapeutically the most difficult part of lacrimal surgery. In the medial canalicular obstructions and/ or common canaliculus obstructions, a proximal patent part of canaliculi can be used for the lacrimal system reconstruction, e.g., canaliculodacryocystorhi-nostomy; however, it is usually not possible to use canaliculi for the reconstruction in proximal cana-licular or complete canalicular obstructions. Many attempts have been made for the relief of the proximal canalicular or extensive canalicular obstructions (see Table 11.2) to produce an epithelial lined tract between the conjunctival sac and the lacrimal sac and nasal cavity, ethmoidal, or antral sinus [11, 21]. The conjunctival flaps have been pulled towards the lacrimal sac and/or the mucosa or grafts of veins have been pulled towards the conjunctiva and/or grafts of veins or the mucosa has been used. Those operations were called lacodacryostomy, lacoductostomy, con-juctivorhinostomy, conjunctivocystorhinostomy, or conjunctivodacryocystorhinostomy, and at present they are rarely performed (Fig. 12.2). The main disadvantage of those techniques is, despite this new epi-

Syringing Lacrimal Ducts
Fig. 12.2. Transposition of a lacrimal sac in a canalicular obstruction. a External conjunctivocystorhinostomy with the transposition of lacrimal sac. b Lacrimal sac is fixed in the medial canthus. (From [14])

Table 12.2. Etiology of extensive canalicular obstructions

Canalicular trauma Radiotherapy

Congenital punctal and canalicular agenesis

Infections (herpes simplex zoster, chlamydia, trachoma, etc.)

Cytostatic therapy (5-fluorouracil)

Following medial canthal tumor excision with extirpation of lacrimal system

Following failed canalicular and other lacrimal surgery Idiopathic thelial-lined tract opened for syringing, the patients are not usually free of epiphora due to nonfunctioning of the lacrimal pump [21].

A glass bypass tube between the conjunctival sac and the nasal cavity was used for the first time in 1925 by J. Heermann, a German otorhinolaryngologist. The tube was inserted through the lower canaliculus [4, 9]. In the ophthalmology literature this procedure is connected with the name of Lester Jones, who described the surgery in 1962. While Heermann used an endonasal approach for the procedure, Jones used an external approach and this technique has prevailed for many years. The procedure is known as Jones' conjunctivodacryocystorhinostomy or dacryocysto-rhinostomy + bypass tube, conjunctive dacryocystorhinostomy, or dacryocystorhinostomy + Jones tube [11-14].

The renaissance of endonasal approach has been widely accepted for lacrimal surgery since the 1980s with the advent of new instruments: rigid fiberoptic endoscope and techniques for endoscopic sinus surgery, with which the procedures can be performed easily and safely. The nasal endoscopy in CDCR enables to perform dacryocystorhinostomy, placement of a tube, and adjunctive intranasal procedures such as a middle turbinectomy or septoplasty. Endoscopy is helpful in the maintenance of a tube, which is often the most challenging and critical aspect of the procedure. The choice of endoscopic vs external CDCR, however, remains that of the lacrimal surgeon guided by his or her surgical experience and the specific surgical case at hand [27].

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