Not applicable.

The protocol followed the guidelines of the local institution&#39;s human research ethics committee and was approved by the local institutional review board (KEK-BE 2019-00555). All operations were performed in general anesthesia under controlled hypotension in anti-Trendelenburg positioning with standard otological instruments.
1. Preparation of the surgical site
<ol>
	<li>Manually adjust the endoscope screens (see Table of Materials) according to the surgeon&#39;s preferred position (sitting or standing).</li>
	<li>Monitor the facial nerve by checking impedances with a nerve monitoring system (see Table of Materials) and perform a tap test13.</li>
	<li>Disinfect the auricle and the retroauricular region with swabs soaked with commercially available povidone-iodine solution (see Table of Materials).</li>
	<li>Drape the periauricular region with sterile blankets.</li>
	<li>Clean and rinse the external auditory canal (EAC) with a blunt syringe and Ringer solution (see Table of Materials).</li>
	<li>Perform white balancing of the camera with white gauze and apply drops of anti-fog solution to the endoscope lens.</li>
</ol>
2. Exclusive transcanal endoscopic approach
<ol>
	<li>Introduce the 0&#176;, 3mm diameter, and 15cm length endoscope in the EAC (see Table of Materials) and clean the EAC by removing earwax and cutting the hairs in the EAC.</li>
	<li>Perform local anesthesia with 0.5 mL of diluted epinephrine (1:200.000) injection (see Table of Materials), each using four injection sites in all quadrants of the EAC under endoscopic control. Additionally, inject 0.5 mL of diluted epinephrine (1:200.000) to the vascular strip in the posterior-superior quadrant of the EAC.</li>
	<li>Inspect the tympanic membrane and the attic region with the 0&#176; endoscope.</li>
	<li>Elevate a tympanomeatal flap tailored to disease extension using an angled round knife and provide hemostasis with epinephrine (1:1000) soaked cottonoids. 
	NOTE: Additional hemostasis may be applied by electrocoagulation using mono- or bipolar cautery; alternatively, radio-frequency-cautery can be used (see Table of Materials). Be careful to use monopolar at the lowest intensities to minimize risks of spread of electricity to the facial nerve.</li>
	<li>Expose the annulus and, if possible, the chorda tympani; open the middle ear cavity, and evaluate in detail the cholesteatoma extension.</li>
	<li>Carefully separate the cholesteatoma matrix from the eardrum and from the chorda tympani.</li>
	<li>Carefully dissect the cholesteatoma involving the middle ear and the incudostapedial area in case of an intact ossicular chain.</li>
	<li>Perform limited atticotomy using unpowered instruments, bone drilling, or ultrasonic devices (see Table of Materials) by stepwise removal of the lateral portion of the attic and evaluate the extent of cholesteatoma infiltration by following the steps below.
	<ol>
		<li>For atticotomy with unpowered instruments: remove small parts of bone, especially the scutum, by a bone curette using rotatory movements or chisel and hammer.</li>
		<li>For attico- and antrotomy with bone drilling: remove larger parts of bone either in an underwater technique14, followed by cutting burrs at low speed (2000-8000 rpm) or cutting or coarse diamond burrs at slow speed with only a little irrigation. 
		NOTE: For the underwater technique, the EAC is filled with 0.9% of NaCl solution, and the endoscope lens is inserted into the EAC with the burrs. Subsequently, drilling for attico- and antrotomy is performed directly under visual inspection. Occasional suction is required due to bone dust and reduced visibility. Utmost care has to be applied to prevent damage to surrounding structures by direct or heat damage. The delicate lens and shaft of the endoscope have to be kept away from the rotatory instruments to prevent its damage.</li>
		<li>For attico- and antrotomy with ultrasonic devices: remove the larger parts of bone with the curved tip in an underwater technique to prevent heat damage to bone and soft tissues. 
		CAUTION: Do not touch the ossicular chain and the cochlea due to possible inner ear hair cell damage due to transmission of micro-vibrations.</li>
	</ol>
	</li>
	<li>If the cholesteatoma infiltrates deep into the anterior epitympanum or erodes the incus, remove the incus and, if required, the malleus head to entirely remove the cholesteatoma.</li>
	<li>Perform stepwise attico- and antrotomy with different devices (see Table of Materials) to follow and completely extirpate the cholesteatoma. Use angled dissectors if appropriate.</li>
</ol>
3. Middle ear exploration
<ol>
	<li>After completion of cholesteatoma resection, an entire middle ear exploration with an emphasis on residual cholesteatoma and functional considerations with the greatest sparing of healthy mucosa is performed. Use first 0&#176; then a 45&#176; angled lens. 
	NOTE: If appropriate, a 70&#176; endoscope may also be used.</li>
	<li>Check anterior epitympanic space, tegmen tympani, posterior epitympanum, antrum until the posterior limit of the lateral semicircular canal.</li>
	<li>Carefully inspect the retrotympanum, including posterior sinus, sinus tympani, subtympanic sinus, and hypotympanum.</li>
	<li>Check Eustachian tube, protympanum, supratubar recess, tensor fold, and isthmus; restore the ventilation route by tissue removal in case of obstruction.</li>
</ol>
4. Reconstruction of the ossicular chain and scutum
<ol>
	<li>Perform an incision 5 mm posterior to the tragus edge and cut through to the cartilage, then harvest a large piece of cartilage with perichondrium on both sides.</li>
	<li>Reconstruct the scutum with a trimmed piece of cartilage and perichondrium for defect closure after attico- and antrotomy.</li>
	<li>Perform underlay tympanoplasty using a trimmed piece of cartilage with overlapping perichondrium in island-graft technique or temporalis fascia for defect closure of the tympanic membrane. Add perichondrium in case of cartilage use for supporting the construction if necessary.</li>
	<li>If the stapes is intact, inspect the incus or head of the malleolus for possible malleolar head or incus interposition ossiculoplasty; otherwise, use double-block cartilage (Malafronte technique15) or PORP (partial ossicular replacement prosthesis).</li>
	<li>Use a TORP (total ossicular replacement prosthesis) if the stapes supra-structure is also affected by cholesteatoma and needs to be removed.</li>
	<li>Use resorbable gelatinous sponges to secure the reconstruction, reinforce the reconstruction using a pressed perichondrium layer or cartilage in case of PORP/TORP.</li>
</ol>
5. Wound closure
<ol>
	<li>Reposition the tympanomeatal flap and adapt it to the EAC curvature without sutures.</li>
	<li>Splint the tympanic membrane with silicone or silk strips of adequate size for defect coverage.</li>
	<li>Pack the EAC with a resorbable gelatinous sponge and the outer part with an antibiotic (polymyxin, neomycin) and hydrocortisone soaked gauze (see Table of Materials).</li>
</ol>

<ol>
	<li>Thomassin, J. M., Korchia, D., Duchon Doris, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endoscopic-guided+otosurgery+in+the+prevention+of+residual+cholesteatomas.">Endoscopic-guided otosurgery in the prevention of residual cholesteatomas.</a> The Laryngoscope. 103 (8), 939-943 (1993).</li><li>Tarabichi, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endoscopic+management+of+acquired+cholesteatoma.">Endoscopic management of acquired cholesteatoma.</a> The American Journal of Otology. 18 (5), 544-549 (1997).</li><li>Emre, I. E., Cingi, C., Bayar Muluk, N., Nogueira, J. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endoscopic+ear+surgery.">Endoscopic ear surgery.</a> Journal of Otology. 15 (1), 27-32 (2020).</li><li>Anschuetz, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Management+of+bleeding+in+exclusive+endoscopic+ear+surgery:+Pilot+Clinical+Experience.">Management of bleeding in exclusive endoscopic ear surgery: Pilot Clinical Experience.</a> Otolaryngology-Head and Neck Surgery. 157 (4), 700-706 (2017).</li><li>Alicandri-Ciufelli, M., Molinari, G., Beckmann, S., Caversaccio, M., Presutti, L., Anschuetz, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Epinephrine+use+in+endoscopic+ear+surgery:+Quantitative+safety+assessment.">Epinephrine use in endoscopic ear surgery: Quantitative safety assessment.</a> Journal for Oto-Rhino-Laryngology. 82 (1), 1-7 (2020).</li><li>Hulka, G. F., McElveen, J. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+randomized,+blinded+study+of+canal+wall+up+versus+canal+wall+down+mastoidectomy+determining+the+differences+in+viewing+middle+ear+anatomy+and+pathology.">A randomized, blinded study of canal wall up versus canal wall down mastoidectomy determining the differences in viewing middle ear anatomy and pathology.</a> The American Journal of Otology. 19 (5), 574-578 (1998).</li><li>Kerckhoffs, K. G. P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+disease+recurrence+rate+after+the+canal+wall+up+or+canal+wall+down+technique+in+adults.">The disease recurrence rate after the canal wall up or canal wall down technique in adults.</a> The Laryngoscope. 126 (4), 980-987 (2016).</li><li>Ayache, S., Tramier, B., Strunski, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Otoendoscopy+in+cholesteatoma+surgery+of+the+middle+ear:+What+benefits+can+be+expected.">Otoendoscopy in cholesteatoma surgery of the middle ear: What benefits can be expected.</a> Otology and Neurotology. 29 (8), 1085-1090 (2008).</li><li>Tarabichi, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endoscopic+management+of+limited+attic+cholesteatoma.">Endoscopic management of limited attic cholesteatoma.</a> The Laryngoscope. 114 (7), 1157-1162 (2004).</li><li>Migirov, L., Shapira, Y., Horowitz, Z., Wolf, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Exclusive+endoscopic+ear+surgery+for+acquired+cholesteatoma:+Preliminary+results.">Exclusive endoscopic ear surgery for acquired cholesteatoma: Preliminary results.</a> Otology and Neurotology. 32 (3), 433-436 (2011).</li><li>Marchioni, D., Villari, D., Mattioli, F., Alicandri-Ciufelli, M., Piccinini, A., Presutti, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endoscopic+management+of+attic+cholesteatoma.+A+single-institution+experience.">Endoscopic management of attic cholesteatoma. A single-institution experience.</a> Otolaryngologic Clinics of North America. 46 (2), 201-209 (2013).</li><li>Kozin, E. D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Systematic+review+of+outcomes+following+observational+and+operative+endoscopic+middle+ear+surgery.">Systematic review of outcomes following observational and operative endoscopic middle ear surgery.</a> The Laryngoscope. 125 (5), 1205-1214 (2015).</li><li>Kartush, J. M., Rice, K. S., Minahan, R. E., Balzer, G. K., Yingling, C. D., Seubert, C. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Best+practices+in+facial+nerve+monitoring.">Best practices in facial nerve monitoring.</a> The Laryngoscope. 131 (4), 1-42 (2021).</li><li>Chen, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+treatment+of+cholesteatomas+involving+the+antrum+and+mastoid+using+transcanal+underwater+endoscopic+ear+surgery.">The treatment of cholesteatomas involving the antrum and mastoid using transcanal underwater endoscopic ear surgery.</a> Otology and Neurotology. 41 (10), 1379-1386 (2020).</li><li>Malafronte, G., Filosa, B., Mercone, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+new+double-cartilage+block+ossiculoplasty:+Long-term+results.">A new double-cartilage block ossiculoplasty: Long-term results.</a> Otology and Neurotology. 29 (4), 531-533 (2008).</li><li>Barakate, M., Bottrill, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Combined+approach+tympanoplasty+for+cholesteatoma:+Impact+of+middle-ear+endoscopy.">Combined approach tympanoplasty for cholesteatoma: Impact of middle-ear endoscopy.</a> Journal of Laryngology and Otology. 122 (2), 120-124 (2008).</li><li>Verma, B., Dabholkar, Y. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Role+of+endoscopy+in+surgical+management+of+cholesteatoma:+A+systematic+review.">Role of endoscopy in surgical management of cholesteatoma: A systematic review.</a> Journal of Otology. 15 (4), 166-170 (2020).</li><li>Magliulo, G., Iannella, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endoscopic+versus+microscopic+approach+in+attic+cholesteatoma+surgery.">Endoscopic versus microscopic approach in attic cholesteatoma surgery.</a> American Journal of Otolaryngology - Head and Neck Medicine and Surgery. 39 (1), 25-30 (2018).</li><li>Das, A., Mitra, S., Ghosh, D., Sengupta, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endoscopic+versus+microscopic+management+of+attic+cholesteatoma:+A+randomized+controlled+trial.">Endoscopic versus microscopic management of attic cholesteatoma: A randomized controlled trial.</a> The Laryngoscope. 130 (10), 2461-2466 (2020).</li><li>Anschuetz, L., Alicandri-Ciufelli, M., Bonali, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Novel+surgical+and+radiologic+classification+of+the+subtympanic+sinus:+Implications+for+endoscopic+ear+surgery.">Novel surgical and radiologic classification of the subtympanic sinus: Implications for endoscopic ear surgery.</a> Otolaryngology - Head and Neck Surgery. 159 (6), 1037-1042 (2018).</li><li>Salami, A., Mora, R., Dellepiane, M., Crippa, B., Santomauro, V., Guastini, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Piezosurgery&#174;+versus+microdrill+in+intact+canal+wall+mastoidectomy.">Piezosurgery&#174; versus microdrill in intact canal wall mastoidectomy.</a> European Archives of Oto-Rhino-Laryngology. 267 (11), 1705-1711 (2010).</li><li>Kakehata, S., Watanabe, T., Ito, T., Kubota, T., Furukawa, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Extension+of+indications+for+transcanal+endoscopic+ear+surgery+using+an+ultrasonic+bone+curette+for+cholesteatomas.">Extension of indications for transcanal endoscopic ear surgery using an ultrasonic bone curette for cholesteatomas.</a> Otology and Neurotology. 35 (1), 101-107 (2014).</li><li>Mehta, R., Mankekar, G., Mayland, E., Melder, K., Arriaga, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endoscopic+inside-out+mastoidectomy+with+the+ultrasonic+bone+aspirator.">Endoscopic inside-out mastoidectomy with the ultrasonic bone aspirator.</a> OTO Open. 3 (1), 1-4 (2019).</li><li>Vincenti, V., Magnan, J., Saccardi, M. S., Zini, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chemically+assisted+dissection+by+means+of+mesna+in+cholesteatoma+surgery.">Chemically assisted dissection by means of mesna in cholesteatoma surgery.</a> Otology and Neurotology. 35 (10), 1819-1824 (2014).</li><li>de la Torre, C., Villamor, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chemically+assisted+dissection+with+sodium+2+mercaptoethanesulfonate+(MESNA)+in+the+surgical+management+of+pediatric+cholesteatoma.">Chemically assisted dissection with sodium 2 mercaptoethanesulfonate (MESNA) in the surgical management of pediatric cholesteatoma.</a> Otology and Neurotology. 40 (5), 645-650 (2019).</li><li>Lee, C. H., Kim, M. K., Kim, H. M., Won, C., Shin, T. H., Kim, S. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endaural+laser-assisted+single-stage+inside-out+cholesteatoma+surgery+(LASIC)+to+treat+advanced+congenital+cholesteatoma.">Endaural laser-assisted single-stage inside-out cholesteatoma surgery (LASIC) to treat advanced congenital cholesteatoma.</a> Otology and Neurotology. 40 (7), 927-935 (2019).</li><li>Lucidi, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Use+of+IMAGE1+S+technology+for+detection+of+cholesteatoma+in+endoscopic+ear+surgery:+a+retrospective+case+series+on+45+patients.">Use of IMAGE1 S technology for detection of cholesteatoma in endoscopic ear surgery: a retrospective case series on 45 patients.</a> European Archives of Oto-Rhino-Laryngology. 278 (5), 1373-1380 (2021).</li></ol>

LA is a consultant for Stryker ENT. All other authors declare no conflict of interest.

This article describes a step-by-step guide as a surgical manual for endoscopic removal of limited attic cholesteatoma. Different techniques for cholesteatoma dissection and bone removal techniques for atticotomy as curettage, bone drills, and ultrasonic devices (piezoelectric devices, ultrasonic bone curettes) are presented. However, single-handed surgery requires habituation, and particular care has to be taken to avoid damage to surrounding structures directly or indirectly during attico- and antrotomy with powered instruments.
Since the first description of exclusive endoscopic cholesteatoma surgery for limited cholesteatoma by Tarabichi in 19972, several studies have been published reporting its successful application in cases of limited attic cholesteatoma. Tarabichi presented in 2004 a cohort of 73 procedures in 69 patients, who all received transcanal exclusive endoscopic cholesteatoma removal, showing 5 cases of recurrence in a mean follow-up period of 43 months9. In 2008, Barakate and Botrill presented 68 procedures of endoscopic cholesteatoma surgery in 66 cases, all of them receiving a second look procedure within a mean of 16 months16. In the second look procedure, 10 ears revealed residual disease, and 4 ears presented a recurrence. Migirov et al. demonstrated no residual disease in 18 patients after exclusive endoscopic cholesteatoma eradication after more than 1 year10. In 2013 Marchioni et al. reported on 146 patients with attic cholesteatoma and 120 patients undergoing an exclusive endoscopic approach; 26 patients underwent an endoscopic procedure combined with mastoidectomy11. Thereof, 7 patients presented with residual cholesteatoma, with no case having limited attic cholesteatoma in the beginning. Thus, the residual and recurrent cholesteatoma rate of 6.4% after endoscopic assisted or exclusive endoscopic removal seems to be comparable to the rate after most CWD procedures with 0%-13.2%, while using a minimally invasive approach7,17. In addition, direct comparison of endoscopic with microscopic techniques revealed significantly better middle ear structural visibility, reduced pain scores, and faster wound healing as further advantages of an endoscopic minimally-invasive approach8,18. Thus, the endoscopic approach seems to be particularly suitable for limited attic cholesteatoma.
Nevertheless, the inaccessibility of cholesteatoma extending deep into the mastoid remains one of the limiting factors in the success of the transcanal exclusive endoscopic approach. Despite the use of angled optics, complete endoscopic explorability is not always feasible, especially in the case of more excavated retrotympanal regions20.
Extended atticotomy was mainly performed by curettes or bone drilling until recently. To avoid the rough and time-consuming bone removal with curettes and possible facial nerve or tympanomeatal flap injury caused by drills, ultrasonic devices may provide a safe and precise alternative in cholesteatoma surgery21. With the transcanal endoscopic retrograde mastoidectomy technique, even removing cholesteatoma extensions into the antrum in a sclerotic mastoid can be achieved by an exclusive endoscopic transcanal approach22,23. However, extensive cholesteatoma formation inside the mastoid or severe hemorrhage might require switching to a microscopic retroauricular approach.
Additionally, there are also recent developments described in the literature to reduce the residual rate of cholesteatoma with chemically or physically assisted dissections. Mesna (sodium 2-mercaptoethanesulfonate) is reported as a possible chemical agent to reduce the residual rate of cholesteatoma by breaking disulfide bridges between different tissues24,25. For physically assisted dissection, different types of lasers known from stapes mobilization procedures have also been used in cholesteatoma surgery, resulting in a low recurrence rate around the ossicular chain26. In addition to white light endoscopy, other image processing technologies based on spectral separation may further improve cholesteatoma removal by recognizing residual cholesteatoma in the final overview27.
Therefore, applying endoscopic cholesteatoma surgery with improved technical devices and chemically or physically assisted dissection is promising to further evolve the minimally invasive approach and reduce the residual disease rate.

The introduction and successive spread of endoscopic ear surgery led to considerable changes in the treatment of cholesteatoma in the past two decades. The first intraoperative use of endoscopes to prevent residual cholesteatoma was already described in 1993 by Thomassin et al.1, followed by the first description of exclusive endoscopic cholesteatoma surgery in 1997 for cases of limited cholesteatoma2. Compared to the excellent but straight-line view with limited illumination in the microscopic approach, the endoscopic approach provides a panoramic view combined with high resolution, high magnification, and the ability to use angled lenses. The technique experiences increasing interest, despite the loss of binocular vision and two-handed working possibility3. As a consequence of the one-handed technique, safe and sufficient hemostasis is required to reap the benefits of superior visualization of the endoscopic technique4,5.
Traditional microscopic approaches might require a canal wall down (CWD) technique with excessive temporal bone drilling for improved visualization and complete removal of the cholesteatoma6. A less invasive alternative for limited cholesteatoma is the canal wall up (CWU) technique, although the limited visualization is often associated with a higher rate of residual cholesteatoma7. Endoscopes were therefore incorporated as an adjunct in canal wall up surgery to reduce the residual rate of cholesteatoma after CWU surgery1,8. Proceeding from this, the transcanal exclusive endoscopic approach has emerged as a possible alternative approach in cholesteatoma surgery as a minimally invasive approach. This resulted in excellent results in limited cholesteatoma with a comparable rate of residual cholesteatoma compared to the traditional CWD technique9,10,11. Nowadays, the exclusive use of endoscopes in cholesteatoma surgery is increasingly documented in the literature, and indications for exclusive endoscopic approaches are continuously expanding12. This work presents an insight into the different technical refinements and latest technological developments for exclusive endoscopic cholesteatoma surgery.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Antifog Solution</td>
			<td>Karl Storz</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr>
			<td>Epinephrine 1 mg/mL</td>
			<td>Dr. Bichsel AG</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr>
			<td>Gelatinous sponge (Gelfoam)</td>
			<td>Pfizer</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr>
			<td>HOPKINS Optic 0&#176;</td>
			<td>Karl Storz</td>
			<td>7220AA</td>
			<td></td>
		</tr>
		<tr>
			<td>HOPKINS Optic 30&#176;</td>
			<td>Karl Storz</td>
			<td>7220BA</td>
			<td></td>
		</tr>
		<tr>
			<td>HOPKINS Optic 45&#176;</td>
			<td>Karl Storz</td>
			<td>7220FA</td>
			<td></td>
		</tr>
		<tr>
			<td>HOPKINS Optic 70&#176;</td>
			<td>Karl Storz</td>
			<td>7220CA</td>
			<td></td>
		</tr>
		<tr>
			<td>Image 1S 4K</td>
			<td>Karl Storz</td>
			<td>TH120</td>
			<td></td>
		</tr>
		<tr>
			<td>ME 102</td>
			<td>KLS Martin</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr>
			<td>Monitor 32&#34; 4K/3D</td>
			<td>Karl Storz</td>
			<td>TM350</td>
			<td></td>
		</tr>
		<tr>
			<td>NIM-Neuro 3.0</td>
			<td>Medtronic</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr>
			<td>OsseoDuo</td>
			<td>Bien Air</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr>
			<td>Otosporin (polymyxin, neomycin, hydrocortison)</td>
			<td>GlaxoSmithKline</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr>
			<td>Piezosurgery device</td>
			<td>Mectron</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr>
			<td>PM2 Line Drill</td>
			<td>Bien Air</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr>
			<td>Povidone-iodine (Betadine)</td>
			<td>Mundi-Pharma</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr>
			<td>Ringer Solution</td>
			<td>B. Braun</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr>
			<td>Standard otological instruments</td>
			<td>Karl Storz</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr>
			<td>Steel and diamand burrs</td>
			<td>Bien Air</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr>
			<td>Syringe Injekt Solo 10 mL</td>
			<td>B. Braun</td>
			<td>N/A</td>
			<td></td>
		</tr>
	</tbody>
</table>

endoscopic cholesteatoma surgery

Implementation of endoscopes in cholesteatoma surgery resulted in considerable changes in the management of cholesteatoma in the last two decades. Compared to the microscopic approach with an excellent but straight-line view and limited illumination, the introduction of endoscopes provides a wide-angled panoramic view. Moreover, angled lenses allow the surgeon to visualize the middle ear and its hidden recesses through a transcanal, minimally-invasive approach. The endoscope enables the surgeon to remove limited cholesteatoma of the middle ear and its recesses using an exclusive endoscopic technique by taking advantage of these benefits. This reduces the rate of residual disease and sparing external incisions and excessive temporal bone drilling as in a transmastoid approach. Since transcanal endoscopic access is mainly a one-handed technique, it implies the need for specific procedures and technical refinements. This article describes a step-by-step guide as a surgical manual for endoscopic removal of epitympanic cholesteatoma. Different techniques for cholesteatoma dissection and bone removal for epitympanectomy, including curettage and powered instruments such as drills and ultrasonic devices with their outcomes, are discussed. This may offer ear surgeons insight into technical refinements and the latest technological developments and open the horizon for different techniques.

A total of 43 consecutive cases of exclusive endoscopic cholesteatoma surgery were analyzed for this study. One surgeon performed all operations; cases needing conversion to a microscopic or combined approach were excluded. Preoperative computed tomography suspected an epitympanal cholesteatoma extension in every case. The mean age (&#177;standard deviation) at the surgery date was 37.36 years (&#177;15.64 years). Seven cases (16.3%) were revision surgeries, thirty-six cases (83.7%) were patients undergoing first cholesteatoma removal. The left side was operated in 26 cases (60.5%), the right side in 17 cases (39.5%).
Surgical Results 
All operations were completed without significant complications like facial nerve palsy or postoperative sensorineural hearing loss, as illustrated in Figure 1. Cartilage was used as grafting material in 38 cases (88.4%) and fascia in 5 cases (11.6%). The graft intake rate (GIR) was 90.7% showing 3 cases of postoperative perforations (7.3%). The mean follow-up was 17.4 months (&#177;10 months), with 40 cases (93%) having no recurrent cholesteatoma at the last follow-up.
Audiological Results 
Each patient underwent standard audiological testing before and after surgery. One patient was already deaf before surgery; thus, no hearing improvement was expected. Two more patients had no postoperative audiogram. Preoperative air bone gap (ABG) of 23.8 dB &#177; 12.6 dB improved significantly (paired t-test with p = 0.0005) to a postoperative ABG of 18.2 dB &#177; 10 dB after surgery. The detailed surgical results are presented in Table 1.
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/63315/63315fig01.jpg" /> 
Figure 1: Overview of the essential surgical steps. <a href="https://www.jove.com/files/ftp_upload/63315/63315fig01large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Age</td>
			<td>37.4 years (14-80 years)</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Side</td>
			<td>26 left side</td>
			<td>17 right side</td>
			<td></td>
		</tr>
		<tr>
			<td>Revision surgery</td>
			<td>36 primary surgery</td>
			<td>7 revision surgery</td>
			<td></td>
		</tr>
		<tr>
			<td>Grafting sucess</td>
			<td>39 successful</td>
			<td>3 perforations</td>
			<td>1 missing follow up</td>
		</tr>
		<tr>
			<td>Grafting material</td>
			<td>38 cartilage</td>
			<td>5 fascia</td>
			<td></td>
		</tr>
		<tr>
			<td>Recidive</td>
			<td>40 without recidive</td>
			<td>3 with recidive</td>
			<td></td>
		</tr>
		<tr>
			<td>Mean ABG</td>
			<td>23.8 &#177; 12.6 dB preoperative</td>
			<td>18.2 &#177; 10 dB postoperative</td>
			<td></td>
		</tr>
	</tbody>
</table>
Table 1: Detailed surgical results.

Watch this Scientific Journal Video about Endoscopic Cholesteatoma Surgery at JoVE.com

Endoscopic Cholesteatoma Surgery

The present protocol describes a step-by-step guide for the complete endoscopic removal of epitympanic cholesteatoma with different techniques for cholesteatoma dissection and bone removal for epitympanectomy.

Implementation of endoscopes in cholesteatoma surgery resulted in considerable changes in the management of cholesteatoma in the last two decades. ...

Research

JoVE Journal

Medicine

9.5K Views.  Inselspital, Bern University Hospital, University of Bern. The present protocol describes a step-by-step guide for the complete endoscopic removal of epitympanic cholesteatoma with different techniques for cholesteatoma dissection and bone removal for epitympanectomy.

Video: Endoscopic Cholesteatoma Surgery

Murine Flexor Tendon Injury and Repair Surgery

Tendon connects skeletal muscle and bone, facilitating movement of nearly the entire body. In the hand, flexor tendons (FTs) enable flexion of the fingers and general hand function. Injuries to the FTs are common, and satisfactory healing is often impaired due to excess scar tissue and adhesions between the tendon and surrounding tissue. However, little is known about the molecular and cellular components of FT repair. To that end, a murine model of FT repair that recapitulates many aspects of healing in humans, including impaired range of motion and decreased mechanical properties, has been developed and previously described. Here an in-depth demonstration of this surgical procedure is provided, involving transection and subsequent repair of the flexor digitorum longus (FDL) tendon in the murine hind paw.&#160;This technique can be used to conduct lineage analysis of different cell types, assess the effects of gene gain or loss-of-function, and to test the efficacy of pharmacological interventions in the healing process. However, there are two primary limitations to this model: i) the FDL tendon in the mid-portion of the murine hind paw, where the transection and repair occur, is not surrounded by a synovial sheath. Therefore this model does not account for the potential contribution of the sheath to the scar formation process. ii) To protect the integrity of the repair site, the FT is released at the myotendinous junction, decreasing the mechanical forces of the tendon, likely contributing to increased scar formation. Isolation of sufficient cells from the granulation tissue of the FT during the healing process for flow cytometric analysis has proved challenging; cytology centrifugation to concentrate these cells is an alternate method used, and allows for generation of cell preparations on which immunofluorescent labeling can be performed. With this method, quantification of cells or proteins of interest during FT healing becomes possible.

Flexor tendons in the hand are commonly injured, leading to impaired hand function. However, the scar-tissue healing response is not well characterized. A murine model of flexor tendon healing is demonstrated here. This model can enhance overall understanding of the healing process and assess therapeutic approaches to improve healing.

Tendon connects skeletal muscle and bone, facilitating movement of nearly the entire body. In the hand, flexor tendons (FTs) enable flexion of the fingers ...

Discovering Middle Ear Anatomy by Transcanal Endoscopic Ear Surgery: A Dissection Manual

The middle ear is located in the center of the temporal bone and bears a highly complex anatomy. The recently introduced exclusively endoscopic transcanal approach to the middle ear is a minimally invasive technique sparing the bone and mucosa of the mastoid bone, since the middle ear is accessed through the external auditory canal. This emerging method has several advantages over the traditional (microscopic) approaches to the middle ear such as the panoramic wide-angle views of the anatomy, the possibility to approach and magnify tiny structures, and the possibility of looking around the corner using angled endoscopes.
The cadaveric dissection method presented here consists of an overview on the technical requirements and a precise description of a step-by-step protocol to discover the anatomy of the middle ear. Each step and anatomical structure is carefully described in order to provide a comprehensive guide to endoscopic ear anatomy. In our opinion, this is particularly important to any novice in endoscopic ear surgery as it provides thorough anatomical knowledge and may improve surgical skills.

The aim of this article is to describe the methodology of exclusively endoscopic cadaveric middle ear dissection. Moreover, we aim to provide a comprehensive guide to endoscopic middle ear anatomy.

The middle ear is located in the center of the temporal bone and bears a highly complex anatomy. The recently introduced exclusively endoscopic transcanal ...

Endoscopic Septoplasty with Limited Two-line Resection: Minimally Invasive Surgery for Septal Deviation

Endoscopic septoplasty is a surgical procedure in otolaryngology that is commonly performed to treat nasal airway obstruction caused by nasal septal deviation. It has a long history with multiple variations. In this article, a modified endoscopic septoplasty procedure using the limited two-line resection (2LoRs) technique at the posterior and inferior junction of the cartilaginous and bony septum is presented based on embryologic and anatomic knowledge of the nasal septum and the biomechanics of cartilaginous behavior. With this procedure, the quadrangular cartilage can be preserved as much as possible, which is helpful in retaining the supporting framework and rigidness of the septum. 2LoRs has been proven effective and sound for the correction of nasal septal deviation with rare complications. This modified procedure can be applied to correct the deviated nasal septum in the absence of any external nasal deformity to improve nasal patency or to improve access to the middle meatus or to the axillary region of the middle turbinate. It may also be used to expand the indications of septoplasty to children and adolescents because of its minimally invasive approach.

Endoscopic septoplasty is a time-honored surgical procedure with multiple variations. This paper focuses on a step-by-step surgical approach to perform a modified septoplasty procedure known as limited two-line resection. This surgical technique can be applied to correct a deviated nasal septum in the absence of an external nasal deformity.

Endoscopic septoplasty is a surgical procedure in otolaryngology that is commonly performed to treat nasal airway obstruction caused by nasal septal ...

Synergizing Antegrade Endoscopic with Bridging Vein Harvesting for Improvement of Great Saphenous Vein Graft Quality from the Lower Leg

Antegrade endoscopic harvesting of autografts for bypass grafting may be an optimal strategy addressing excellent graft quality and reduced post-operative wound complications. This standardized protocol for antegrade endoscopic vein harvesting (EVH) from the lower leg has the potential to be introduced to routine coronary artery bypass grafting (CABG). Patients undergoing CABG surgery are positioned on a surgical table with two additional foam rollers below the extended legs, enabling antegrade EVH from the lower leg. Following minimally invasive surgical access through a bridging vein harvest technique, an endoscopic optical dissector is inserted antegrade into the wound. The main vessel and side branches are dissected under continuous optical control of vein quality status and the working channel. After, an endoscopic optical retractor is inserted with an internal bipolar electrocoagulation device for precise, safe, and tissue-protective interruption of side branches. After release of the vein, the vessel is cut off at the proximal and distal ends under optical control, retrieved from the wound, then cannulated and flushed with heparinized saline. Finally, all side branches of the vein graft are double-clipped. Vascular histology is analyzed in a randomized selection of vein samples. After applying this standardized EVH protocol, the learning curve was shown to be steep, and graft quality was sufficient for coronary artery bypass grafting in every case. There was no conversion to surgical harvesting and low risks for tissue damage and bleeding. Leg positioning and synergizing EVH with bridging vein harvesting improved procedural success and vein graft quality. In our hands, antegrade EVH from the lower leg was feasible, demonstrating straightforward graft dissection as well as adequate macroscopic and microscopic graft quality with preserved endothelial integrity. In conclusion, the introduced technique is safe, shows excellent vein autograft quality, and illustrates feasibility for elective and urgent isolated CABG and combined CABG scenarios.

Presented here is a protocol for antegrade endoscopic vein harvesting from the lower leg, which can safely be introduced in routine coronary artery bypass grafting. Vein grafts present excellent graft quality following this standardized protocol with positioning of the legs, minimally invasive access to the vein, and antegrade endoscopic vein harvesting.

Antegrade endoscopic harvesting of autografts for bypass grafting may be an optimal strategy addressing excellent graft quality and reduced post-operative ...

Endaural Endoscopic Atticoantrotomy (Retrograde Mastoidectomy) using a Constant Suction Bone-drilling Technique

Endoscopic middle ear surgery is a widely employed minimally invasive surgical technique to address middle ear and mastoid pathology. Bone drilling is the main technical challenge of endoscopic middle ear surgery. The accompanying video describes the detailed protocol of a constant-suction bone-drilling technique and the procedure of endaural exclusive endoscopic atticoantrotomy (retrograde mastoidectomy) using this technique. The main components of this bone-drilling technique include a soft and flexible suction tube, which is placed into the tympanic cavity to provide constant suction, and a soft sleeve, which is wrapped around the drill shaft to prevent the high-speed rotating shaft from damaging the lens of the endoscope. With these simple modifications, the traditional otological electrodrill can be used for drilling a tiny endaural incision in endoscopic middle ear surgery. Based on this bone-drilling technique, endaural endoscopic atticoantrotomy (retrograde mastoidectomy) can be successfully established for the removal of various amounts of bone, depending on the extent of the lesion. The short-term postoperative outcome seems promising.

Endaural Endoscopic Atticoantrotomy Retrograde Mastoidectomy using a Constant Suction Bone-drilling Technique

In this paper, we present the protocol and short-term outcomes of endaural exclusive endoscopic atticoantrotomy using a constant suction bone-drilling technique.

Endoscopic middle ear surgery is a widely employed minimally invasive surgical technique to address middle ear and mastoid pathology. Bone drilling is the ...

Step-by-Step Stapedotomy through Transcanal Exclusive Endoscopic Approach

In recent years there has been an increasing trend in the use of the endoscope to treat a variety of middle ear pathologies, including otosclerosis. Several studies comparing traditional microscopic and endoscopic stapes surgery have reported similar hearing results and an overall low rate of complications. The endoscope has unraveled its full potential in demanding settings of stapes surgery, such as unfavorable anatomy of the oval window niche or revision cases. Reduced manipulation of the chorda tympani and low rate of post-operative dysgeusia are further benefits to mention for endoscopic stapes surgery.
Being a one-handed technique, management of bleeding, positioning, and crimping of the prosthesis may be challenging for novice endoscopic surgeons, so some training in endoscopic ear surgery is recommended before performing endoscopic stapedotomy. The problem of sharing the surgical field between the endoscope and the operating instruments could be easily overcome if proper instruments positioning is understood. One-handed bleeding control in the narrow space of the ear canal may represent an issue during the elevation of the tympano-meatal flap, possibly discouraging the surgeon since the preliminary steps of surgery. Following appropriate technique to raise the flap and the collaboration with the anesthesiology team in keeping the blood pressure low guarantee an adequate bleeding control in most cases.
The aim of this article is to describe the entire surgical procedure of a transcanal exclusive endoscopic stapedotomy, from operating room set up and patient positioning to post-operative care. A step-by-step description of the surgical maneuvers with technical hints is reported, to guide the surgeon across the procedure and allow any ear surgeon to perform stapes surgery endoscopically.

The aim of this article is to provide a step-by-step method for endoscopic stapes surgery from operating room setting and patient positioning to post-operative care. This work would represent a guide for any otologic surgeon who is willing to treat otosclerosis with endoscopic transcanal technique.

In recent years there has been an increasing trend in the use of the endoscope to treat a variety of middle ear pathologies, including otosclerosis. ...

Endoscopic Ultrasound-Guided Biliary Drainage: Endoscopic Ultrasound-Guided Hepaticogastrostomy in Malignant Biliary Obstruction

Patients with unresectable malignant biliary obstruction often require biliary drainage to decompress the biliary system. Endoscopic Retrograde Cholangiopancreatography (ERCP) is the primary biliary drainage method whenever possible. Percutaneous Transhepatic Biliary Drainage (PTBD) is used as a salvage method if ERCP fails. Endoscopic Ultrasound-Guided Biliary Drainage (EUS-BD) provides a feasible alternative biliary drainage method where one of the methods is EUS guided Hepaticogastrostomy (EUS-HGS). Here we describe the EUS-HGS technique in a case of unresectable malignant hilar biliary obstruction to achieve biliary drainage.
Presented here is the case of a 71-year-old female with painless jaundice and weight loss for 2 weeks. Computed Tomography (CT) imaging showed a 4 x 5 cm hilar tumor with lymphadenopathy and liver metastasis. EUS fine needle biopsy (FNB) of the lesion was consistent with cholangiocarcinoma. Her bilirubin levels were 212 &#181;mol/L (&lt;15) during presentation.
A linear echoendoscope was used to locate the left dilated intrahepatic ducts (IHD) of the liver. The segment 3 dilated IHD was identified and punctured using a 19 G needle. Contrast was used to opacify the IHDs under fluoroscopic guidance. The IHD was cannulated using a 0.025-inch guidewire. This was followed by the dilation of the fistula tract using a 6 Fr electrocautery dilator along with a 4 mm biliary balloon dilator. A partially covered metallic stent of 10 cm in length was deployed under fluoroscopic guidance. The distal part opens in the IHD and the proximal part was deployed within the working channel of the echoendoscope that subsequently released into the stomach. The patient was discharged three days after the procedure. Follow up performed in the second and fourth weeks showed that the bilirubin levels were 30 &#181;mol/L and 14 &#181;mol/L, respectively. This indicates that EUS-HGS is a safe method for biliary drainage in unresectable malignant biliary obstruction.

Endoscopic Ultrasound-Guided Biliary Drainage (EUS-BD) is an alternative method of biliary decompression in malignant biliary obstruction. Here we describe the technique of EUS guided-Hepaticogastrostomy (EUS-HGS) in a case of unresectable malignant hilar biliary obstruction.

Patients with unresectable malignant biliary obstruction often require biliary drainage to decompress the biliary system. Endoscopic Retrograde ...

Fully Endoscopic Mitral Valve Repair with Percutaneous Cannulation of Groin Vessels

Endoscopic mitral valve surgery (EMS) has become a standard of care at specialized heart centers, further reducing surgical trauma compared to a traditional minimally invasive, thoracotomy-based approach. Exposure of the groin vessels for the establishment of cardiopulmonary bypass (CPB) via surgical cutdown in minimally invasive surgery (MIS) may result in wound healing disorders or seroma formation. The avoidance of surgical exposure of the groin vessels by using fully percutaneous techniques for the insertion of a CPB cannula with the implementation of vascular pre-closure devices has the potential to reduce these complications and improve clinical results. Herein, we present the utilization of a novel plug based vacsular closure device with a resobable collagen plug and the absence of suture material for closure of the arterial access for CPB in MIS. While this device was initially predominantly used in transcatheter aortic valve implantation (TAVI) procedures, with its safety and feasibility shown, we herein show that it can be used in CPB cannulation, since it is capable of closing arterial access sites up to 25 French (Fr.) in size. This device may be suitable to significantly reduce groin complications in MIS and simplify the establishment of CPB. Here, we describe the fundamental steps of EMS, including percutaneous groin cannulation and decannulation using a vascular closure device.

This protocol demonstrates in detail how to perform fully endoscopic mitral valve surgery (EMS) with percutaneous cannulation of the groin vessels, using a percutaneous plug-based vascular closure device. Fundamental steps and useful instructions are described in detail for each step.

Endoscopic mitral valve surgery (EMS) has become a standard of care at specialized heart centers, further reducing surgical trauma compared to a ...

Gasless Endoscopic Thyroidectomy via the Trans-Axillary Approach

For patients with early, low-risk papillary thyroid carcinoma, an increasing number are opting for endoscopic thyroid surgery due to its ability to achieve favorable therapeutic outcomes while maintaining excellent cosmetic results. Among the available endoscopic procedures, the Gasless Endoscopic Thyroidectomy Trans-axillary Approach (GETTA) has gained popularity among surgeons. This is attributed to its straightforward cavity construction, spacious operating area, precise visual field exposure, and manageable learning curve. However, few studies have provided detailed descriptions of the specific surgical steps involved in GETTA. Drawing from a synthesis of existing literature and our own clinical expertise, we present a comprehensive outline of the GETTA procedure. This process can be categorized into five distinct stages: positioning and incision planning; establishment of surgical cavities; identification and protection of the recurrent laryngeal nerve, inferior parathyroid gland, and central neck dissection; localization and preservation of the superior laryngeal nerve, superior parathyroid gland, and dissection of the thyroid's superior pole; transection of the thyroid isthmus followed by en bloc resection of the thyroid gland and central neck lymph nodes. The five-step approach of GETTA is easy to learn and can be adapted for resecting both benign and malignant thyroid and parathyroid diseases.

Gasless Endoscopic Thyroidectomy via the Trans-Axillary Approach

This protocol presents the procedure for conducting thyroidectomy using the gasless endoscopic thyroidectomy trans-axillary approach (GETTA).

For patients with early, low-risk papillary thyroid carcinoma, an increasing number are opting for endoscopic thyroid surgery due to its ability to ...

A 3-Channel Endoscopic Technique for Lumbar Stenosis and Contralateral Herniation

The Third Channel-Assisted Unilateral Biportal Endoscopic Technique for Lumbar Spinal Stenosis Combined with Contralateral Disc Herniation

Unilateral biportal endoscopic (UBE) spine surgery is an emerging minimally invasive surgical (MIS) technique that has gained popularity for treating lumbar spinal stenosis, particularly in Eastern Asia. The traditional UBE technique, with two portals on one side, can achieve successful unilateral laminotomy for bilateral decompression (ULBD) and, therefore, demonstrates favorable clinical outcomes. However, in the case of lumbar spinal stenosis combined with contralateral disc herniation, it is very difficult to remove the contralateral disc herniation, especially the loose disc fragment within the deep disc. Here, a third channel of the traditional UBE technique was developed to do the discectomy within the ipsilateral endoscopic vision, with which the instruments can go vertically into the contralateral disc, allowing easy discectomy. This technique can not only achieve adequate decompression of the bilateral spinal canal but also effectively remove contralateral herniated disc fragments. This technique avoids performing another UBE procedure on the opposite side, which can potentially shorten the duration of the operation, minimize blood loss and tissue damage, and ensure sufficient neural decompression. This paper will introduce the indications and surgical operation procedures, as well as present a classical case report and follow-up data, to facilitate the application of the third channel-assisted UBE (T-UBE) technique for spine surgeons.

Author Spotlight: Unveiling the Potential of TUBE Technique in Spinal Surgery

Here, we present the third channel-assisted UBE technique, which allows for the vertical removal of herniated disc fragments. This technique can effectively address the limitations of traditional UBE techniques. This article will systematically elaborate on this procedure.

Unilateral biportal endoscopic (UBE) spine surgery is an emerging minimally invasive surgical (MIS) technique that has gained popularity for treating ...