The Learning Curve in Endoscopic Dacryocystorhinostomy: Outcomes in Surgery Performed by Trainee Oculoplastic Surgeons.

PURPOSE: To report outcomes of endoscopic DCR (En-DCR) performed by oculoplastic trainees and describe factors to improve success rates for trainees. METHODS: Retrospective, single-centre audit of En-DCR procedures performed by three consecutive trainee oculoplastic surgeons, over a 3-year period. Trainees also completed a reflective-learning questionnaire highlighting challenging and technically difficult aspects of En-DCR surgery, with relevant tips. RESULTS: Thirty-eight consecutive independently-performed en-DCR procedures on 38 patients (mean age 58.6 ± 21.4 years) were studied. Mean time spent in the operating-theatre was 95.7 ± 27.3 minutes. Success rate for each year was 15/17(88%), 8/8(100%) and 7/13(54%), respectively, at mean follow-up 12.5 ± 12 months. The lowest success rate year coincided with use of silicone stents in 31% cases compared to 94% and 100% in the previous 2 years. In cases that failed, video-analysis highlighted inadequate superior bony rhinostomy (2 cases), incomplete retroplacement of posterior-nasal mucosal-flaps (3 cases), significant bleeding (1 case). Those who underwent revision surgery (n = 6), were found to have soft-tissue ostium and sac closure requiring flap revision. Two-cases required further bone removal supero-posterior to the lacrimal sac. Trainees-tips that helped improve their surgery related to patient positioning, instrument handling, bone removal and posture. CONCLUSION: Good surgical outcomes are achievable training in en-DCR surgery. Adequate operating time needs to be planned. Failure was primarily due to closure of the soft-tissue ostium, either secondary to inadequate osteotomy and sac-marsupialisation or postoperative scarring. Intra-operative mucosal trauma is higher amongst trainees and adjuvant silicone stenting during the training period may be of value where mucosal adhesions are anticipated.

Positional relationship between medial canthal tendon and common canalicular orifice: A cadaveric study.

PURPOSE: To examine the positional relationship between the medial canthal tendon (MCT) and the common canalicular orifice (CCO) in cadavers. METHODS: This experimental anatomical study was conducted using 75 orbits from 48 embalmed Japanese cadavers fixed in 10% buffered formalin (24 orbits from 17 males and 51 orbits from 31 females; 38 right and 37 left; mean age at time of death, 84.1±9.2 years). The vertical width of the MCT on the level of the medial orbital rim and the angle between the MCT and axial plane were measured. In addition, the vertical distance from the CCO to the lower edge of the MCT was measured. Positive values of the distance were indicated when the CCO was located below the lower edge of the MCT. RESULTS: The vertical distance from the CCO to the lower edge of the MCT was -1.43±1.31mm. Only 13 orbits (17.3%) showed the CCO located on the same level (2 orbits, 2.7%) or below the lower edge of the MCT (11 orbits, 14.7%), while the CCO was located above the lower edge of the MCT in 62 orbits (82.7%). In multiple regression analyses, both the MCT width and angle between the MCT and axial plane were not correlated with the distance (P>0.050). CONCLUSIONS: As the CCO was mostly found to be located above the inferior margin of the MCT, the creation of the bony window up to the MCT's inferior margin is not sufficient in external dacryocystorhinostomy to completely expose the CCO.

An update on endoscopic mechanical and powered dacryocystorhinostomy in acute dacryocystitis and lacrimal abscess.

PURPOSE: To provide a brief review of the literature on the utility and outcomes of endoscopic dacryocystorhinostomy (DCR) in patients with acute dacryocystitis (ADC) and lacrimal abscess. METHODS: The authors performed a PubMed search of all articles published in English on endoscopic powered or mechanical DCR performed during the stage of acute dacryocystitis. Data captured include demographics, clinical presentations, time interval to surgery, intraoperative challenges, post-operative course, complications and outcomes. Specific emphasis was laid on addressing the intra-operative challenges and post-operative outcomes. RESULTS: Increased intra-operative bleeding is a common finding. The use of mitomycin C and silicone intubation are not uncommon and are not reported to have negative influence on the outcomes of surgery. The general consensus is to initiate antibiotics immediately or a day before surgery and continue them in the post-operative period. Symptomatic pain relief was achieved very early (immediate to <3 days) and complete resolution was usually achieved in a week's time. The overall anatomical success rates varied from 81.8 to 96.2% and functional success from 72.7 to 96.2%. Cicatricial closure of the ostium was a common cause of failure. CONCLUSION: Primary endoscopic DCR appears to be an effective modality in the management of ADC and lacrimal abscess, and results in a rapid resolution of inflammation while achieving comparable surgical success with a traditional approach of conservative management with or without drainage and 2nd stage external DCR.

Pediatric endonasal dacryocystorhinostomy and operative standardization.

OBJECTIVE: The objective of this study was to confirm that the standardized endonasal dacryocystorhinostomy (DCR) technique routinely performed in adults can be used in children. MATERIALS AND METHODS: A consecutive series of children undergoing endonasal DCR between 2003 and 2017 was analysed. The surgical procedure consisted of: preoperative CT scan, anatomical localization of the ideal surgical zone, access to the nasal cavity via an optional planned enlargement, creation of a mucoperiosteal flap, osteotomy with rongeurs and equatorial resection of the medial wall of the lacrimal sac. This pediatric series was compared to a series of adult patients operated according to the same standardized technique. RESULTS: A total of 20 DCRs (17 patients, with a mean age of 8 years (range: 4-16)) were included. Anatomical localization was effective in 100% of cases without the need for transillumination. With a mean follow-up of 4 years, the success rate was 95%, and no major complications were observed. Comparison with the same surgical technique in adults revealed similar results. DISCUSSION: Our experience suggests that standardized endonasal DCR can be adapted to the nasal cavities of children. Anatomical localization is effective. The physiologically narrow nasal cavity does not constitute a major obstacle with the use of slightly smaller instruments. The results and complications are similar to those observed in adults. CONCLUSION: The same standardized endoscopic endonasal DCR surgical technique can be used in adults and children with a similar good success rate.

Anatomical considerations in endoscopic lacrimal surgery.

PURPOSE: To provide a review of the anatomy of the lacrimal drainage system and lateral wall of the nose pertaining to endoscopic dacryocystorhinostomy. METHODS: The authors performed a PubMed search of articles published pertaining to the anatomy of the lateral wall of the nose and the anatomy of endonasal and external dacryocystorhinostomy surgery. RESULTS: The article covers the regional surface and surgical anatomy for endoscopic dacryocystorhinostomy (DCR), including the maxillary line, middle turbinate, agger nasi air cell, lacrimal sac and fossa and the upper portion of the nasolacrimal drainage system. It also explores the dimensions and location of bony ostium formation to ensure full exposure and marsupialisation of the lacrimal sac. Finally, it covers the anatomy of potential complications of endoscopic DCR surgery including penetration of the skull base and orbit, inadvertent entry to the maxillary sinus and breach of the skin. CONCLUSION: A good understanding of the anatomy of the lacrimal drainage system and the lateral wall of the nose will increase the likelihood of successful surgery and minimize the risk of complications and damage to neighbouring structures such as the orbit and skull base.

[Endocanalicular dacryocystorhinostomy (E-DCR): relevance of materials standardization for outcomes]. / Dacriocistorrinostomía endocanalicular (DCR-E): importancia de la estandarización de materiales en los resultados.

INTRODUCTION AND OBJECTIVES: After 5 years' experience with endocanalicular dacryocystorhinostomy (E-DCR) using diode laser, the introduction of new materials has led to significant technical differences, thus giving rise to this study to evaluate them. MATERIAL AND METHOD: We compare the behaviour of 2 different kinds of laser guide fibre (silica-fluoropolymer-tefzel and silica-silica-polyamide), using the same laser generator, on organic tissues from fresh animal carcases, and we summarize the clinical behaviour of the new materials in lachrymal surgery cases. RESULTS: We have seen significant differences in the clinical behaviour of the two kinds of laser guides, namely the proposed new materials have a worse behaviour on organic tissues than their physical characteristics might theoretically have suggested. Thus, the use of different guide materials could lead to relevant differences in terms of surgical results, as well as in the comparison of the outcomes of series performed by different surgeons. CONCLUSIONS: It is necessary to determine standards for the materials recommended for this surgery, not only for easier technical performance and better effectiveness, but also to allow comparison of results from different authors.

[Transcanalicular laser-assisted dacryocystorhinostomy: initial results]. / Dacriocistorrinostomia transcanalicular com laser diodo: resultados preliminares.

PURPOSE: To describe the technique and initial results of laser-assisted dacryocystorhinostomy performed through the canaliculi. METHODS: Ten patients with nasolacrimal duct obstruction underwent transcanalicular laser-assisted dacryocystorhinostomy. A silicone tube was inserted through the canaliculi and the ostium into the nasal cavity where it will be kept for 6 months. RESULTS: All ten operations were performed without negative occurrences. One patient presented displacement of the silicone tube one day after surgery. Nine of the ten patients reported disappearance of epiphora at the end of the first week following surgery. During the first month, one of these patients presented with epiphora due to obstruction of the lacrimal-nasal fistula and another lost the silicone tube in the first month following surgery. CONCLUSIONS: Transcanalicular laser-assisted dacryocystorhinostomy is a potentially useful method to perform dacryocystorhinostomy.

[Endoscopic nasal dacryocystorhinostomy: results and advantages over the external approach]. / Dacriocistorrinostomia endoscópica nasal: resultados e vantagens sobre a abordagem externa.

UNLABELLED: Dacryocystorhinostomy (DCR) is a procedure used to create a lachrymal drainage pathway into the nasal cavity in order to reestablish the permanent drainage of a previously obstructed excretory system. AIM: to report our results obtained with endoscopic DCR technique, describing its advantages and disadvantages STUDY DESIGN: Historic cohort. MATERIAL AND METHOD: we retrospectively analyzed thirty-two dacryocystorhinostomies performed at the Otorhinolaryngology Discipline from March 2002 to January 2004 on patients with post-lachrymal sac obstruction confirmed by dacryocystorhinography (DCG). In all cases, the patients were submitted to probing with Crawford probe. RESULTS: surgery was bilateral in ten of the twenty-two analyzed patients, totaling thirty-two procedures, twenty-nine of which were primary surgeries and three revision procedures after unsuccessful external DCR. Our success rate was 79.12%. CONCLUSIONS: endoscopic DCR proved to be a safe and low morbidity technique, which also avoids facial scars and maintains the mechanism of the lachrymal pump, with results similar to those obtained with external DCR.

Anterior suspended flaps: a modified approach for external dacryocystorhinostomy.

BACKGROUND/AIMS: External dacryocystorhinostomy (DCR) is a reliable but difficult surgical technique for the treatment of any obstruction of the lacrimal drainage system lying distal to the internal opening of the common canaliculus. In this prospective study, a simplified external DCR procedure and the results obtained on a series of 45 consecutive patients, in which traditional external DCR was indicated, are described. METHODS: In this modified procedure only very large and mobile anterior flaps of the lacrimal sac and nasal mucosa are created. Thanks to the large size and the great motility the two flaps can be easily sutured. Two double armed 6/0 polyglycolic acid sutures are used to join the two flaps, to elevate them anteriorly in order to avoid adhesions with underlying tissues, and to approximate the deep planes of the wound. The mean operative time was measured. RESULTS: At the end of follow up period (mean 17 months, range 14-24 months) all patients had no sign or symptoms of tearing and normal Jones I dye test. The mean operative time was 28.6 minutes (range 23-44 minutes). CONCLUSION: We believe that our modified technique can be used to simplify and speed up traditional external DCR without decreasing its well known reliability.

[Modern principles of endonasal surgery on the lacrimal duct]. / Sovremennye printsipy éndonazal'noi khirurgii slezootvodiashchikh putei.

Intranasal operations on the lacrimal duct developed in 1910 by G. West are rarely used now. The author analyzes his experience gained in 5000 endonasal dacryocystorhinostomies (96.7% of which were effective) and the advantages of intranasal approach to the lacrimal duct and presents a working classification of dacryocystitis. Indications for endonasal surgery on the lacrimal duct and contraindications precluding it are defined and a table for selecting the appropriate intranasal intervention in cases with abnormal discharge of tears offered. The author emphasizes the efficacy of endonasal operations and advocates wide use of this method in dacryology.

Sleeve technique to maintain a large mucosal ostium during endoscopic dacryocystorhinostomy.

Currently, many surgeons use bicanalicular silicone tubes as a stent to keep the intranasal mucosal ostium patent when they perform endoscopic dacryocystorhinostomy. The authors describe the sleeve technique using bicanalicular silicone tubes. After inserting the bicanalicular silicone tube, a sleeve is passed over it. The sleeve prevents the nasal mucosa from obstructing the intranasal mucosal ostium and enlarges the mucosal ostium. In primary acquired nasolacrimal duct obstruction, the sleeve technique was applied to 61 cases (group 1); the other 75 cases (group 2) were intubated by bicanalicular silicone tube only. The overall success rate was 95.1% in group 1 and 90.7% in group 2 (P = .51), and the average mucosal ostium at 6 months postoperatively was 3.2 ± 1.1 and 1.9 ± 1.0 mm (P = .04), respectively. The authors believe that the sleeve technique has the advantage of maintaining a larger intranasal mucosal ostium.

Cost-efficiency of endoscopic and external dacryocystorhinostomy.

BACKGROUND: In most centres in the United Kingdom, endoscopic dacryocystorhinostomy is currently undertaken as a joint operation between ophthalmologists and otolaryngologists. The addition of an extra surgeon, the use of endoscopic equipment and the relatively lower success rate of this procedure made us compare endoscopic dacryocystorhinostomy and external dacryocystorhinostomy with regards to costs and income for our hospital. METHODS: All 38 primary endoscopic dacryocystorhinostomy cases performed in our centre in 2001-2003 were retrospectively compared with the 49 external dacryocystorhinostomy cases performed in 1993-2000. Cost-income calculations were made based on: rate of local anaesthesia, success rate, rate of day case admission, hospital reference cost for dacryocystorhinostomy, and the income per case extracted from national tariffs (based on the Health Resources Group). Also, the average number of cases per session was used to calculate the income gained per session for each method. RESULTS: The following rates between the endoscopic and the external dacryocystorhinostomy were found: local anaesthesia, 29 vs 6 per cent, respectively; day-case operation, 95 vs 12 per cent, respectively; and success rate, 87 vs 94 per cent, respectively. The average number of endoscopic dacryocystorhinostomy cases conducted in a single theatre session was twice that of external dacryocystorhinostomy cases. Endoscopic dacryocystorhinostomy generated approximately twice the income of external dacryocystorhinostomy (6585 pounds vs 3292 pounds, respectively). CONCLUSION: Endoscopic dacryocystorhinostomy is more cost-effective than external dacryocystorhinostomy, despite having a lower success rate and greater usage of resources, as the endoscopic procedure generates more income. This is mainly due to the higher number of cases per session and the higher rates of local anaesthesia and day case operations possible.

Endonasal dacryocystorhinostomy: a report by the American Academy of Ophthalmology.

OBJECTIVE: This document describes endonasal dacryocystorhinostomy (DCR) and examines the evidence to answer key questions about the effectiveness of the procedure compared with external DCR; the relative indications, contraindications, advantages, and limitations of the procedure; and patient selection, surgical technique, postoperative care, and complications. METHODS: A literature search conducted for the years 1968 to 2000 retrieved 93 citations. The panel members reviewed 71 of these articles and selected 64 for the panel methodologist to review and rate according to the strength of evidence. A level I rating is assigned to properly conducted, well-designed, randomized clinical trials; a level II rating is assigned to well-designed cohort and case-control studies; and a level III rating is assigned to case series and poorly designed prospective and retrospective studies, including case-control studies. RESULTS: The published literature includes two reports that describe clinical trials comparing endonasal with external DCR with a 1-year follow-up. The success rate was 91% for the external DCR group in both reports and 63% and 75% for the endonasal DCR groups, defined by patency to irrigation. A longitudinal cohort study included a control group of age-matched external DCR patients who were compared with a study group of endonasal DCR patients. The reported success rate at 9 months following surgery for the endonasal cohort was 90% and was not statistically significantly different from the 94% success rate noted in the external DCR control group. Remaining data on reported success rates of primary and revision endonasal DCR were obtained from a collection of uncontrolled observational case studies with varying periods of follow-up and success rates ranging from 59% to 100%. CONCLUSIONS: It is difficult to make definite evidence-based determinations about the relative efficacy of endonasal and external DCR because of the deficiencies in the reported literature. Based on level III evidence, the available data suggest that endonasal DCR may be a viable option for the correction of acquired nasolacrimal duct obstruction and complex forms of congenital dacryostenosis in selected patients. This procedure may be indicated on a primary basis or as revisional surgery following failed external or endonasal DCR. Some studies comparing endonasal DCR with external DCR suggested lower success rates in the endonasal group; other studies yielded success rates comparable with or exceeding those of external surgery. Reported complications of endonasal DCR do not generally appear to be greater in frequency or magnitude than those associated with external DCR. Disadvantages of endonasal DCR include the preferred use of general anesthesia by many surgeons, the high cost of expensive equipment and instrumentation, and the relatively steep learning curve for this procedure. Depending on the preference of the surgeon, more postoperative care may be required for patients undergoing endonasal DCR than external DCR. Both the advantages and the limitations of endonasal DCR relative to external DCR should be carefully discussed with patients who are contemplating endonasal surgery.

Systematic unciformectomy for a standardized endonasal dacryocystorhinostomy.

PURPOSE: To describe a standardized osteotomy method for endonasal dacryocystorhinostomy (en-DCR) and the results obtained. DESIGN: Prospective nonrandomized, noncomparative, interventional case series study. PARTICIPANTS: One hundred consecutive adult patients (81 females, 19 males) underwent en-DCR performed by the same team of oculoplastic and rhinologic surgeons. METHODS: A standardized procedure was used in all cases. This included endoscopic assessment of the surgical site from the nasal aspect, diaphanoscopy of the common canaliculus, and endonasal osteotomy. Anterior unciformectomy was followed by resection of the lacrimal bone and protected drilling of the maxillary bone of the lacrimal fossa to expose the entire medial aspect of the lacrimal sac. The middle turbinate was preserved whenever atraumatic dissection of the nasal mucosa was possible or when it was resected partially before osteotomy. MAIN OUTCOME MEASURES: Rate of direct localization of the lacrimal fossa, rate of turbinectomy/septoplasty, rate of residual postoperative tearing, rate and nature of complications RESULTS: Transillumination of the common canaliculus was obtained directly in 94% of cases; transillumination, required the opening of an ethmoidal cell in 2%, partial resection of the middle turbinate in 3%, and unciformectomy in 1%. Access to the surgical site required partial resection of the middle turbinate in 21% of cases, but no septoplasty. Osteotomy was initiated in 90% of cases by cleavage of the anterior insertion of the uncinate process, and in 5% by cleavage of the first, overdeveloped ethmoidal cell. The cleavage opened directly to the medial aspect of the lacrimal fossa in these 95 cases. Osteotomy was achieved by drilling alone in only five cases. Perioperative complications were limited to significant bleeding in six cases. Postoperative complications included one case of resolved frontal sinusitis on day 3, and one case of inferior lid hematoma with emphysema. CONCLUSIONS: The authors suggest that anterior resection of the uncinate process is the most important surgical step to expose the medial aspect of the lacrimal fossa during endonasal DCR, whereas partial resection of the middle turbinate can be considered optional.

Dacriocistorrinostomia transcanalicular com laser diodo: resultados preliminares / Transcanalicular laser-assisted dacryocystorhinostomy: initial results

OBJETIVO: Descrever a técnica e os resultados iniciais da dacriocistorrinostomia com laser diodo, realizada pela via transcanalicular. MÉTODOS: Dez pacientes com diagnóstico de obstrução lacrimal baixa foram submetidos à dacriocistorrinostomia com laser diodo, realizada pela via transcanalicular. A via lacrimal foi entubada com silicone, onde deveria permanecer por 6 meses. RESULTADOS: Todas as dez cirurgias foram realizadas sem intercorrências. Um paciente apresentou saída do tubo de silicone, um dia após a cirurgia. Após uma semana, os outros nove, relataram desaparecimento da epífora. Durante o primeiro mês de seguimento, mais um paciente apresentou perda do tubo de silicone e outro voltou apresentar epífora, por obstrução da fístula lacrimonasal. CONCLUSÕES: A dacriocistorrinostomia assistida por laser diodo, realizada pela via transcanalicular, é novo método para tratamento da obstrução das vias lacrimais. Com o desenvolvimento desta técnica espera-se aumento no índice de sucesso cirúrgico, tanto imediato como a longo prazo.

PURPOSE: To describe the technique and initial results of laser-assisted dacryocystorhinostomy performed through the canaliculi. METHODS: Ten patients with nasolacrimal duct obstruction underwent transcanalicular laser-assisted dacryocystorhinostomy. A silicone tube was inserted through the canaliculi and the ostium into the nasal cavity where it will be kept for 6 months. RESULTS: All ten operations were performed without negative occurrences. One patient presented displacement of the silicone tube one day after surgery. Nine of the ten patients reported disappearance of epiphora at the end of the first week following surgery. During the first month, one of these patients presented with epiphora due to obstruction of the lacrimal-nasal fistula and another lost the silicone tube in the first month following surgery. CONCLUSIONS: Transcanalicular laser-assisted dacryocystorhinostomy is a potentially useful method to perform dacryocystorhinostomy.

Dacriocistorrinostomia endoscópica nasal: resultados e vantagens sobre a abordagem externa

A Dacriocistorrinostomia (DCR) consiste em criar uma via de drenagem lacrimal para a cavidade nasal, tendo como objetivo restabelecer a drenagem permanente deste sistema excretor previamente obstruído. OBJETIVO: Relatar nossos resultados com a técnica de DCR endoscópica, expondo vantagens e desvantagens em relação à técnica externa. FORMA DE ESTUDO: Coorte histórica. MATERIAL E MÉTODO: Foram analisadas retrospectivamente trinta e duas dacriocistorrinostomias realizadas pela Disciplina de Otorrinolaringologia de março de 2002 a janeiro de 2004 em pacientes com obstrução pós-saco lacrimal comprovada por dacriocistografia (DCG). Todos foram submetidos à sondagem com sonda de Crawford. RESULTADOS: Dos vinte e dois pacientes analisados, a cirurgia foi bilateral em dez totalizando trinta e dois procedimentos, sendo vinte e nove cirurgias primárias e três casos revisionais de insucessos com DCR externa. Nossa taxa de sucesso foi de 79,12 por cento. CONCLUSÕES: A DCR endoscópica mostrou ser uma técnica segura, com baixa morbidade, além de evitar cicatrizes faciais e manter o mecanismo de bomba lacrimal, com resultados semelhantes à DCR externa.

Dacriocistorrinostomía endocanalicular (DCR-E): importancia de la estandarización de materiales en los resultados / Endocanalicular dacryocystorhinostomy (E-DCR): relevance of materials standardization for outcomes

Introducción y objetivos: Después de un periodo de 5 años de experiencia con la dacriocistorrinostomía endocanalicular (DCR-E) con láser diodo, la introducción de nuevos materiales ha originado diferencias técnicas significativas que motivan el presente trabajo para su evaluación. Material y método: Se compara el comportamiento de dos tipos distintos de fibra de guía de láser (sílice-fluoropolímero-tefzel y sílice-sílice-poliamida), usando un mismo generador, sobre tejido orgánico de cadáver animal fresco, y se resume el comportamiento clínico de los nuevos materiales en una serie de casos de cirugía lagrimal. Resultados: Hemos observado diferencias relevantes en el comportamiento clínico de dos tipos distintos de fibras de guía de láser, y se objetiva que los nuevos materiales propuestos tienen un comportamiento sobre tejido orgánico peor de lo que sus características físicas teóricas hacen suponer. Así, la utilización de diferentes materiales de guía puede implicar diferencias relevantes en los resultados de la cirugía, así como en el momento de evaluar estas técnicas en diferentes series realizadas por distintos cirujanos. Conclusiones: Debe buscarse una estandarización de los materiales recomendados para estas cirugías, tanto por su utilidad y efectividad clínica como en la comparación de resultados de diferentes series (AU)

Introduction and objectives: After 5 years’ experience with endocanalicular dacryocystorhinostomy (E-DCR) using diode laser, the introduction of new materials has led to significant technical differences, thus giving rise to this study to evaluate them. Material and method: We compare the behaviour of 2 different kinds of laser guide fibre (silica-fluoropolymer-tefzel and silica-silica-polyamide), using the same laser generator, on organic tissues from fresh animal carcases, and we summarize the clinical behaviour of the new materials in lachrymal surgery cases. Results: We have seen significant differences in the clinical behaviour of the two kinds of laser guides, namely the proposed new materials have a worse behaviour on organic tissues than their physical characteristics might theoretically have suggested. Thus, the use of different guide materials could lead to relevant differences in terms of surgical results, as well as in the comparison of the outcomes of series performed by different surgeons. Conclusions: It is necessary to determine standards for the materials recommended for this surgery, not only for easier technical performance and better effectiveness, but also to allow comparison of results from different authors (AU)