# I. Introduction he concept of obliteration of the mastoid cavity was first introduced by Mosher in 1911 to promote healing of a mastoidectomy defect [1] . Mosher originally used a superiorly based post auricular soft tissue flap. Kisch described the use of a pedicled temporalis muscle flap that was further expanded on by Rambo [2,3] . Popper described the use of a periosteal flap used to line, rather than obliterate the mastoid cavity [4] . Palva went on to describe a modification of Popper's flap as a musculoperiosteal flap to obliterate the mastoid bowl [5] . Palva further added the use of bone chips and bone pate´ in combination with a musculoperiosteal flap [6] . In addition to bone pate´, other materials that have been described for mastoid obliteration include fat grafts, diced cartilage, fascia, bone chips, and ceramic materials such as hydroxyapatite [7][8][9][10][11] . # II. Large Cavity Problems The primary goal of surgical intervention for chronic ear disease is the development of a safe, dry, low-maintenance and hearing ear [12,13] . Exteriorization of attic, mastoid and middle ear with a CWD mastoidectomy has a high rate of success in achieving a safe and dry ear [12] , but there is a need for continuous inspection of the cavity and a high incidence of moisture resulting in discharge [14] . Persistent moisture, infection, and discharge may cause problems in as many as one-third of patients requiring revision surgery following CWD mastoidectomy [14] , which may be attributed to mucosalized surfaces, persistent cell tracts, or poorly ventilated areas opening into the mastoid bowl [13] . Despite careful observation of best practices including mastoid saucerization, removal of the mastoid tip, lowering of the facial ridge, and creation of an adequate-size meatus [15] , moisture may still persist in areas of the mastoid bowl leading to stasis of mucoid exudate, localized areas of infection, and underlying mucosal changes. Open mastoid procedures have been criticized for the unfavorable cosmetic appearance due to a large meatoplasty, the need for regular cleaning, as well as the increased incidence of discharge and recurrent infections [13,16] . These concerns have led some to primarily advocate the use of Canal-Wall-Up (or Intact Canal Wall) mastoidectomies [15] , or propose the reconstruction of the ear canal-mastoid partition [17] or obliteration of the mastoid cavity [13,[18][19][20] . # III. Techniques for Mastoid Obliteration Many techniques for mastoid obliteration have been described in the literature. Palva described a meatally based musculoperiosteal flap in combination with the use of cortical bone chips and bone pate´ for mastoid obliteration [5,6] . Moffat and colleagues described the use of bone pate´ and a superiorly based temporalis musculoperiosteal flap for mastoid obliteration [21] . Some authors even advocated the use of mastoid obliteration for canal wall-up mastoidectomy in an attempt to prevent retraction pockets and recurrent cholesteatoma [22,23] . Montandon and colleagues described the use of cartilage to block the aditus and an abdominal fat graft for the canal wall-up mastoidectomy cavity [22] . Gantz and colleagues described reconstruction of the posterior canal wall and mastoid obliteration [24] . Their technique consisted of removal of the posterior bony canal wall with a micro sagittal saw. The mastoid cavity is obliterated with bonepate´ and bone chips followed by replacement of the posterior canal wall segment. An anteriorly based musculoperiosteal Palva flap is used to cover the obliterated mastoid cavity. Some authors described the use of the Temporo Parietal Fascial Flap (TPFF) based on the superficial temporal artery for mastoid obliteration. East and colleagues and Cheney and colleagues [25,26] described the successful use of this TPFF flap for mastoid obliteration. It provides an excellent option when standard pedicled muscle or periosteal flaps are not available as in revision cases with scar tissue or in patients with previous irradiation. There are numerous reports in the literature, of the use of calcium phosphate ceramic granules and hydroxyapatite for mastoid obliteration. Hartwein and colleagues described the use of hydroxyapatite to obliterate the mastoid bowl while reconstructing the posterior canal wall with autologous conchal cartilage [27] . Yung and colleagues in their series describe 34 cases of mastoid obliteration using hydroxyapatite granules and an inferiorly based periosteal flap [28] . Proponents of the use of synthetic materials such as hydroxyapatite point out the minimal resorption of these materialsover time [29] . Mahendran and colleagues describe the use of hydroxyapatite cement for mastoid obliteration [30] . In their study, however, there was a significant incidence of postoperative infection with 50% of the patients requiring revision surgery and removal of the foreign material (hydroxyapatite). # IV. How we do it A post auricular incision 5mm posterior to the post auricular groove is made. A thorough canal-wall down mastoidectomy is performed and saucerized, adequate lowering of the facial ridge and clearance of all mucosa and squamous epithelium in all the mastoid air cell systems is done. The temporalis muscle is exposed. A postero-superiorly based temporalis muscle flap is fashioned (Fig. 1). The flap receives abundant blood supply mainly from the posterior deep temporal artery which courses upward and backward in the area of the muscle included in the flap. The flap is now rotated into the mastoid cavity and hence used to obliterate the cavity (Fig. 2). The senior author has performed over 950 mastoid surgical procedures which includes about 360 canal-wall-down (CWD) mastoidectomies in a span of 25 years. He has used the Rambo Flap for obliteration of the cavity in about one third (about 120) of the CWD mastoidectomies where the final size of the cavities appeared too large and necessitated obliteration to reduce the size. The temporalis fascia is then placed over the flap and under the tympanic membrane remnant. An adequate meatoplasty is performed to facilitate good inspection of the thus reduced-size cavity. # V. Conclusion In the modern era of ear surgeries, mastoid cavities due to canal-wall-down mastoidectomy are obliterated using various techniques and materials. In our experience, the Rambo Flap, described as early as 1958, is an effective method to obliterate the mastoid cavities in CWD mastoidectomies. 12![Fig. 1: Schematic Diagram Demonstrating the Fashioning of the Rambo Flap (Right Ear)](image-2.png "Fig. 1 :Fig. 2 :") ## Abbreviations CWD -Canal-Wall-Down. TPFF -Temporo-Parietal Fascial Flap. * A method of filling the excavated mastoid with a flap from the back of the auricle HPMosher Laryngoscope 21 1911 * Temporal muscle grafts in the radical mastoid operation JKisch J. Laryngol 735 1928 * Primary closure of the radical mastoidectomy wound: a technique to eliminate postoperative care JHRambo Laryngoscope 68 1958 * Periosteal flap grafts in mastoid operations OPopper S. Afr. Med. J 1935 9 77 * Operative technique in mastoid obliteration TPalva Acta Otolaryng 75 1973 * Mastoid obliteration TPalva Acta Otolaryngol Suppl 360 1979 * Surgical modification of the difficult mastoid cavity JLDornhoffer Otolaryngol Head Neck Surg 120 1999 * Hydroxyapatite canal wall reconstruction/mastoid obliteration SAEstrem GHighfill Otolarngol Head Neck Surg 120 1999 * Biphasic ceramics and fibrin sealant for bone reconstruction in ear surgery MBD'arc GDaculsi NEmam Ann Otol Rhinol Laryngol 113 2004 * Surgical management of the discharging mastoid cavity RPMills J Laryngol Otol Suppl 16 1988 * Mastoid obliteration with bone MCShea GGardner Jr MESimpson Otolaryngol Clin North Am 1972 1 * Glasscock-Shambaugh Surgery of the Ear. People's Medical Publishing House AJGulya LBMinor GlasscockM EPoe D 2010 USA * Revision mastoidectomy JNadolJr 39:723-40. vi-vii. Otolaryngol Clin North Am 2006 Pub Med: 16895781] * Canal wall down mastoidectomy: A long term commitment to the outpatients? HSKhalil PCWindle-Taylor BMC Ear Nose Throat Disord 1. 3 2003 Pub Med: 12956889] * Cholesteatoma surgery: Canal wall down procedures JLSheehy Ann Otol Rhinol Laryngol 97 1988 Pub Med: 3277524] * The behavior of mastoidectomy cavities following modified radical mastoidectomy GThiel JARutka DDPothier Laryngoscope 124 2014 Pub Med: 24459037] * Ceravital reconstruction of canal wall down mastoidectomy: Long-term results DellaSantina CCLee SC Arch Otolaryngol Head Neck Surg 132 2006 Pub Med: 16785406] * Mastoidectomy and mastoid obliteration with autologous bone graft: A quality of life study GKurien KGreeff NGomaa 42:49 J Otolaryngol Head Neck Surg 2013 Pub Med: 24330542] * Postauricular periosteal-pericranial flap for mastoid obliteration and canal wall down tympanomastoidectomy RamseyM JMerchant SNMckenna MJ Otol Neurotol 25 2004 Pub Med: 15547414] * Mastoid obliteration RPMehta JPHarris Otolaryngol Clin North Am 39 2006 Pub Med: 17097437] * Mastoid obliteration using bone pate´ DAMoffat GrayR FIrving RM Clin Otolaryngol 19 1994 * Modified canal wall-up mastoidectomy with mastoid obliteration for severe chronic otitis media PMontandon MBenchaou JPGuyot ORL 57 1995 * Mastoid obliteration in intact canal wall mastoidectomy EVartiainen RHarma Clin Otolaryngol 12 1987 * Canal wall reconstruction tympanomastoidectomy with mastoid obliteration BJGantz WilkinsonE PHansen MR Laryngoscope 115 2005 * Mastoid obliteration with the temporoparietal fascialflap CAEast MDBrough HRGrant J Laryngol Otol 105 1991 * Mastoid obliteration and lining using the temporoparietal fascial flap MLCheney CAMegerian MTBrown Laryngoscope 105 1995 * A technique for the reconstruction of the posterior canal wall and mastoid obliteration in radical cavity surgery JHartwein KHormann Am J Otol 11 3 1990 * The use of hydroxyapatite granules in mastoid obliteration MWYung Clin Otolaryngol 21 1996 * Reconstruction of the ear canal wall using hydroxylapatite with and without mastoid obliteration and by obliteration with bone chips TGyllencreutz Acta Otolaryngol (Stock) 1992 Suppl 492 * Mastoid obliteration with hydroxyapatite cement: the Ipswich experience SMahendran MWYung Otol Neurotol 25 2004