V.A. Obodov, E.S. Borzenkova (Ekaterinburg Center of the Scientific and Technical Complex "Microsurgery of the Eye", Director – O.V. Shilovskikh) Abstract. The first stage is an endonasal endoscopic dacryocystorhinostomy. Then, through a 2-mm diameter tunnel made in the soft tissues with a trephine, a lacoprosthesis is intubated, passing through the rhinostomy into the nasal cavity, with endoscopic control of its position. The advantages of this method: 1) the correct, more physiological position of the lacoprosthesis with three supporting elements and a guarantee against displacement; 2) performing an endoscopic cystorhinostomy first creates conditions for minimally invasive formation of a tunnel between the lacrimal lake and the lacrimal sac. Lacrimal drainage duct obliteration using the proposed technique can be recommended for cases of obliteration of the entire horizontal lacrimal duct, coarse cicatricial structures in the medial third of both lacrimal canaliculi, and recurrent dacryocystitis after unsuccessful surgeries. Restoring tear drainage in cases of subtotal and total lacrimal canaliculi obliteration, combined with deformities of the inner canal with post-traumatic cicatricial deformities of the horizontal lacrimal duct, represents one of the most challenging tasks in dacryosurgery. Despite numerous reconstructive techniques based on restoring their anatomical integrity, functional results are often not achieved. In clinical practice, lacrimal drainage duct obstruction (lacidacryostomy) or conjunctivodacryostomy (conjunctivodacryostomy) are used to create an anastomosis between the lacrimal lake and the lacrimal sac. If this is ineffective or the nasolacrimal duct is also obstructed, lacrimal drainage duct obstruction (lacyrrhoea) is performed to create a new anastomosis between the lacrimal lake and the nasal cavity. and V.V.Motorny (2000) [2] proposed a simplified method of lacorinostomy that does not require a skin incision and performing an external dacryocystorhinostomy. Communication between the lacrimal lake and the nasal cavity is achieved in this method by forming a 4-5 mm wide tunnel incision with a linear knife in the direction of the lacrimal fossa, perforating the bone with a trocar-perforator. Then the opening is widened with Bowman probes to No. 9-10 and an individually prepared lacorinoprosthesis is inserted into the resulting anastomosis. In connection with the development of micro- and endosurgical technologies, opportunities have arisen to improve the lacorinostomy technology in terms of minimizing trauma and invasiveness due to visualization of manipulations in the performance of all stages of the operation, achieving a more physiological, durable location of the lacorinoprosthesis. The aim of the study was to develop a modern improved technique of lacorinocystorhinostomy. Materials and methods. Five patients with cicatricial post-traumatic obliteration of both lacrimal canaliculi were operated on using the proposed method. Previous attempts to restore the lacrimal drainage system in other clinics had been unsuccessful. An Azimut videoendoscopic system, an Eleps shaver system, and endo- and microsurgical instruments were used. The method is performed as follows. General anesthesia (endotracheal anesthesia) was administered. This ensures the preservation of the existing anatomical relationships of the soft structures in the surgical area and the precision of the manipulations performed (no tissue edema). Initially, an endonasal endoscopic dacryocystorhinostomy is performed. Technique: turundas with a mixture of 0.1% galazolin and 2% lidocaine solutions are used to anemize the nasal mucosa. Then, under the guidance of a rigid endoscope (rhinoscope) with a 4 mm diameter and end-on optics, a 2% ultracaine solution with epinephrine is injected submucosally in front of the middle turbinate at the site of the lacrimal sac. This ensures a virtually bloodless procedure. Next, a valve-shaped incision is made in the nasal mucosa with a sickle knife in the projection of the floor of the lacrimal fossa and the beginning of the nasolacrimal canal; the mucosal flap is folded back and removed with a shaver. Next, a 4 x 4 mm hole is made in the bone in the projection of the floor of the lacrimal fossa with a shaver with an aggressive tip. Palpation of the skin in the area of ??the lacrimal sac projection reveals a bulge of its medial wall into the bony opening. Under endoscopic guidance, the lacrimal sac is fenestrated with a sickle knife or trephine. The next step is performed under an operating microscope. The lower half of the lacrimal caruncle is excised to ensure a gaping opening for the lacrimal prosthesis and prevent its possible blockage. Hemostasis is achieved using a radiofrequency microcoagulator (Mira OS 3000). Using a 2 mm diameter ophthalmic trephine, a tunnel is formed in the soft tissues, obliquely downwards from the level of the lacrimal caruncle at an angle of 50-60°, passing through the lacrimal sac. The passage of the trephine through the walls of the sac and further into the nasal cavity is monitored with an endoscope via a monitor. The lacrimal prosthesis is inserted into the formed trephine channel using a No. 5 Bowman probe. We used lacrimal prosthesis from FCI (France) in the form of a 40 mm long silicone tube with an outer diameter of 2 mm, an inner diameter of 1.5 mm, and a cap-sleeve at the proximal end of 4 mm. The prosthesis passes through the formed channel, through the soft tissue of the inner canthus, the lacrimal sac, and the rhinostomy, and its nasal end is placed in the common nasal meatus at the bottom of the nasal cavity. The ocular end of the prosthesis is secured with two 7:0 Vicryl sutures to the surrounding conjunctiva and one loop suture to the skin of the supraorbital area for 2 weeks. Results and discussion. All interventions were uneventful, and the results were monitored for up to 5 months. One patient (a 13-year-old child) removed the lacoprosthesis after 1 week and underwent re-implantation. Postoperatively, the lacoprosthesis was rinsed every 2 weeks, and endoscopic rhinoscopy with nasal cavity cleaning and inspection of the nasal end of the prosthesis was performed. Lacrimation ceased in all patients. The ocular end of the prosthesis was virtually invisible. Among the advantages of this method are: placement of a 2 mm diameter lacoprosthesis in a 2 mm diameter tunnel ensures rapid formation of a dense, fibrous, supportive framework along it, which is one of the prerequisites for proper prosthesis fixation. Passage of the lacoprosthesis through the lacrimal sac also ensures its correct, physiological, near-vertical position with additional support and free tear drainage due to the higher hydrostatic pressure of the fluid within it. Small rhinostomy incisions are less traumatic and fibrosize more quickly, fitting the nasal end of the lacoprosthesis like a sphincter, thereby creating a third anchoring element and preventing displacement. Initially performing a minimally invasive cystorhinostomy—without a skin incision or disruption of the anatomy and fixation of the lacrimal sac—creates the conditions for minimally invasive formation of the lacrimal lake-lacrimal sac tunnel. Lacocystorhinostomy using the proposed technique can be recommended for obliteration of the entire horizontal lacrimal duct, severe cicatricial strictures in the medial third of both lacrimal canaliculi, and recurrent dacryocystitis after unsuccessful surgeries. We believe this type of surgery can also be performed for obliteration of the lacrimal sac. Thus, endoscopic lacocystorhinostomy with permanent intubation is a gentle option for eliminating "intractable" lacrimation. The standard 40 mm long FCI lacoprosthesis is optimally suited for this technology; the location of the nasal end of the prosthesis at the bottom of the nasal cavity enhances the tear suction effect due to nasal breathing. ENDOSCOPIC LACOCYSTORINOSTOMY WITH PERMANENT IMPLANT V.A. Obodov, E.S. Borzenkova (IRTC "Eye Microsurgery" Ekaterinburg Center) The aim of this paper is to develop a modern, advanced technology for lacocystorinostomy. Stage 1 includes endonasal endoscopic dacryocystorinostmy, and then a lacoprosthesis is implanted through the stoma into the nasal cavity with endoscopic control of its position. This method has the following advantages: 1) correct, more physiologic lacoprosthesis position with three supporting elements and guarantee against dislocation; 2) initial endoscopic cystorinostomy creates conditions for microinvasive forming of the tunnel from the lacrimal lacus to the lacrimal sac. Lacocystorinostomy according to the suggested variant may be recommended in cases with obliteration of the entire horizontal portion of the lacrimal pathways, rough scars in the medial third of both lacrimal canaliculi, recurrent dacryocystites after failed surgery. Five patients with posttraumatic obliteration of both lacrimal canaliculi have been operated according to the suggested technique with positive results. Literature. Diseases of the lacrimal organs. Samara, 2001. Pp. 191-215. , V.V.Motorny. Practical guide to the treatment of diseases of the lacrimal organs. Minsk, 2000. Pp.