Canal Wall Down Research Articles

Clinical analysis of 8 cases of delayed facial paralysis after middle ear surgery

Objective:To investigate the possible causes, prevention, treatment and recovery of delayed facial paralysis after middle ear surgery. Method:A retrospectively analysis of the data of 8 patients with delayed facial paralysis after middle ear surgery under general anesthesia, including one case of tympanoplasty （type Ⅰ） , one case of tympanotomy+tympanoplasty c（type Ⅰ） , one case ofepitympanotomy+reconstruction of attic lateral wall+tympanoplasty （type Ⅱ ）, four cases of canal wall down+tympanoplasty （ type Ⅱ） and one case of canal wall up mastoidectomy. After discovering the facial paralysis, the stuffing in the surgical cavity was released and removed for all patients immediately. Necessary stuffing was replaced by dexamethasone gauze （not press hardl）. Meanwhile, patients took methylprednisolone orally and were intramuscularly injected with mecobalamine. Result:Among eight patients, there were six patients with horizontal exposure of facial nerve and two patients with pyramis exposure of facial nerve. There was one case, five cases and two cases of delayed facial paralysis at five days, one week and two weeks after operation respectively. There were six patients suffering from the facial paralysis of HB Ⅱ grade and two patients suffering from the facial paralysis of HB Ⅲ grade. Four patients recovered four weeks and the remaining four patients returned to normal six weeks after surgery. Conclusion:Delayed facial paralysis is one of complications of the middle ear surgery, and most of patients can recover completely after conservative treatment.

Comparing the Incidence of Residual Cholesteatoma Using two Canal Wall Down and Endoscopic-assisted Intact Canal Wall Tympanomastoidectomy Methods

Background: For many years, Canal Wall Down (CWD) tympanomastoidectomy has been the gold standard for treatment of cholesteatoma; however, this method has long-term complications for the patients. The Intact Canal Wall (ICW) tympanomastoidectomy has relatively lower complications, but access to the middle-ear recesses is difficult in this method. Therefore, endoscopy is used to visualize the underexposed recesses. Objective: This study aims to compare the incidence of residual cholesteatoma using the two methods of CWD and endoscopic-assisted ICW. Materials and Methods: In this prospective randomized clinical trial, participants were 40 patients with cholesteatoma in the middle ear and mastoid who were candidates for tympanomastoidectomy. They were randomly divided into two groups. In the first group, ICW was performed with endoscopic assisted visualization, while in the second group, conventional CWD technique was performed without ossicular reconstruction. All the patients were microscopically examined at 3, 6, 9 and 12 months after surgery. Revision middle ear surgery and possible ossicular reconstruction under local anesthesia were performed one year after the surgery. The presence of cholesteatoma pearl in the middle-ear, evaluated by using a 2.7mm 30° endoscope, was recorded as the sign of residual cholesteatoma. Fisher’s exact test and Mann-Whitney U test were used for statistical analysis. Significance level for the tests was set at 5%. Results: The incidence of residual cholesteatoma was not statistically significant between the two groups (P>0.05). In each group, 20% (n=4) had residual cholesteatoma. The difference in time interval from the first to second surgery was not statistically significant between the study groups (P>0.05). Conclusion: Endoscopic-assisted ICW tympanomastoidectomy is comparable with CWD tympanomastoidectomy in eradication of cholesteatoma, having possibly fewer complications. It is recommended that more studies be conducted with a larger sample size and longer follow-up period.

Analysis of surgical effect on middle ear cholesterol granuloma

Objective:To evaluate surgical effects on middle ear cholesterol granuloma（CG）. Method:The patients receiving surgery due to middle ear CG were retrospectively analyzed. The choice of operative methods was made according to medical history, endotoscope, pure-tone audiometry and temporal bone CT. Tympanostomy tube（TT） insertion was performed on 12 patients; canal wall up（CWU） tympanoplasty combined with tympanostomy tube was performed on 40 patients, and canal wall down（CWD） tympanoplasty combined with TT on 14 cases. The pre-and postoperative audiometric results（500, 1000, 2000 and 4000 Hz） were evaluated for each patient. Then the average air-bone gap（ABG） was analyzed. Result:One patient had postoperative tube obstruction. One patient who performed only TT insertion recurred. Secretory otitis media occurred in one case undergoing CWU tympanoplasty after removal of the ventilation tube. For TT insertion group, pre-and postoperative ABG levels were （21.25±5.96） dB and （8.85±6.49） dB, respectively（P<0.01）. For CWU+TT group, pre-and postoperative ABG levels were （34.19±10.43） dB and （23.55±12.48） dB, respectively（P<0.01）. For CWD+TT group, pre-and postoperative ABG levels were （36.43±12.11） dB and （25.71±13.50） dB, respectively（P<0.01）. Conclusion:The aim of surgical treatment for middle ear CG includes thorough removal of lesions, improvement of ventilation and drainage of middle ear. Individualized surgical strategy should be adopted according to the patients' conditions. And long-term follow-up should be done after operation.

Mastoid Obliteration Using Autologous Bone Dust Following Canal Wall Down Mastoidectomy.

To describe a technique for mastoid obliteration following canal wall down (CWD) mastoidectomy for chronic otitis media with cholesteatoma, and review its early results in producing a dry, safe ear, and a small mastoid cavity. Retrospective review. Tertiary referral center. Forty-three consecutive CWD procedures using bone dust obliteration for chronic otitis media. All patients underwent CWD mastoidectomy and, if indicated, concurrent tympanoplasty and ossicular chain reconstruction. Bone dust harvested from healthy mastoid cortex was used to obliterate selected portions of the tympanomastoid defect. Temporalis fascia and/or an inferiorly-based periosteal flap were used for coverage of the bone dust. Postoperative infection, need for mastoid bowl cleaning, incidence of recurrent cholesteatoma, need for revision surgical intervention. At mean follow-up of 29 months, 95% of ears have remained dry and safe since mastoid obliteration, with a lack of symptoms and no evidence of recurrent disease. Cholesteatoma recurrence rate was 5%. Postoperative otorrhea, while rare, was managed successfully with topical medication in all affected patients. Clinical, radiographic, and surgical appearance of grafted bone dust suggests good take with long-term viability. The described technique used for mastoid obliteration using autologous bone dust and cartilage is simple, effective, and safe to reduce the size of the mastoid cavity in patients undergoing CWD mastoidectomy. It might help to reduce morbidity by improving the surgeon's control over mastoid bowl size and shape.

A Simple Technique to Obliterate Canal Wall Down Mastoid Cavity Concurrently in Squamosal Otitis Media: Our Experience.

Chronic suppurative otitis media is a type of otitis media defined as a long standing infection of a part or whole of the middle ear cleft. Squamosal type of CSOM involves parsflaccida characterised by the formation of cholesteatoma. The present study is retrospective analysis of records of patient who underwent canal wall down mastoidectomy with obliteration of cavity using posteroinferiorly based musculoperiosteal flap with autogenous cartilage and bone pate. Study include patients who underwent canal wall mastoidectomy with cavity obliteration at Tertiary care Hospital Yavatmal, Maharashtra, India; during 2year period of 2016-2018. 41 patients (42 ears) who underwent canal wall down mastoidectomy with cavity obliteration procedure were included and 06 patients were excluded as they failed to follow up. The outcomes were measured by Marchant et al. grading scale. As per the study it was observed that 88% (37 out 42 ears) got adequate control of infection with dry cavity, while 12% (5 ears) failed to attain dry ear. So it's been concluded that canal wall down mastoidectomy is an effective surgical procedure in management of squamosal type of CSOM and mastoid obliteration is proved technique to improve outcomes of canal wall down procedure. Technique used to develop posteroinferiorly based flap to obliterate cavity in our study is simple modification of routine surgical steps commonly practiced by otologist helpful in reducing cavity size and promoting healthy epithelization. Cavity obliteration technique used in study is very effective and simple to develop dry and trouble free cavity in around 90% cases.

Mastoid abscess as a Presenting Complaint of Kostmann syndrome in childhood.

Kostmann syndrome is a rare congenital disorder characterized by severe neutropenia due to impairment of myeloid differentiation in the bone marrow, with the neutrophil count being characteristically less than 500_103 cells/lMale child 4.5-year old complains from a bilateral aural discharge of 2years duration. examination there is multiple skin scars, gapped postauricular wound with necrosis in parts and inflamed lower part of mastoid and upper part of neck, and bilateral pinhole central perforation with pulsating discharge. Normal cranial nerve examinations. Hematological investigations were done that reveal severe neutropenia (kostmann syndrome).canal wall down (CWD) mastoidectomy with wide meatoconchoplasty for exteriorization of the cavity was done Removal of infected and necrosed tissues in the postauricular region, undermining of skin and primary repair was done in two layers . after that, ear discharge and postauricular swelling improved and patient with good general condition with an excellent outcome.so mastoid abscess can be a presenting symptom of Kostmann syndrome.

Bone Pate Obliteration in Canal Wall Down Mastoidectomy: Modifications of an Established Technique.

To describe outcomes with obliteration of the mastoid and medial attic following canal wall down mastoidectomy for cholesteatoma. Our technique uses bone pate in the mastoid and cartilage in the epitympanum and supratubal recess. Retrospective observational study. Tertiary medical center. Ten years of sequential canal wall down mastoidectomies with obliteration from one neurotologist were reviewed. This included primary and revision cases in adults and children. Complications, location and extent of cholesteatoma, the presence of a dry ear after surgery, cholesteatoma recidivism, revision procedures, and postoperative hearing. Seventy-eight patients (79 ears) met inclusion criteria. There were few major complications. There was active follow-up of a year or more in 61. For these, the mean follow-up was 3.1 years, and approximately 90% had a dry cavity for the remainder of their follow-up. About half required minimal (if any) maintenance. There were five cases with residual disease, and no cases with recurrent disease. There were five cases that were considered failures, with three taking several years to manifest. There were no cases where cholesteatoma was buried in bone pate. A sizeable minority continued to have active tubotympanic disease despite successful treatment of the attic and mastoid. This seems to be a safe and reliable means to eradicate cholesteatoma and create a dry, low-maintenance cavity. It is not a cure for tubotympanic disease, and a small minority of initially stable cavities may fail several years following surgery. 4.

Comparison of mastoid obliteration with middle temporal artery flap versus open cavity: a comparative study

&lt;p class="abstract"&gt;&lt;strong&gt;Background:&lt;/strong&gt; The objective was to study the outcomes of the canal wall down (CWD) mastoidectomy patients in those with soft canal wall reconstruction by using middle temporal artery (MTA) flap in comparison to those with cavity left open.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Methods:&lt;/strong&gt; A prospective study of 20 patients undergoing CWD surgery was done with 10 in each group of mastoid obliteration and open cavity. The outcomes were studied at 1, 3, 6 and 12 months post-surgery. &lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Results:&lt;/strong&gt; At the final assessment of 12 months post op, the obliteration group had only 10% patients with grade 1 infection while open cavity group had 40% with grade 2 infection. Obliteration of mastoid cavity and reconstruction of canal wall with soft tissue MTA flap gave excellent control of infection.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Conclusions:&lt;/strong&gt; The MTA flap is highly flexible and versatile for otologic reconstruction with an excellent arc of rotation and robust blood supply. It does not have the issues of resorption, dehiscence or fistula formation faced in other obliteration techniques.&lt;/p&gt;

Study of Hearing Status After Canal Wall Down Mastoidectomy with Type-III Tympanoplasty

Objective: To observe hearing status in case of canal wall down mastoidectomy with type III tympanoplasty.&#x0D; Methods: This was a cross sectional study which was carried out in the departments of Otolaryngology and Head-Neck surgery of Bangabondhu Sheikh Mujib Medical University during the period of July’ 2011 to March’ 2012.A Total 38 patients having cholesteatoma underwent canal down mastoidectomy with type III tympanoplasty,were included in this study. Patients were divided into two groups according to their age. Age belonged to 18 years and more than 18 years were considered as child and adult respectively. Patients were examined thoroughly and preoperative hearing level was assessed by pure tone audiometry one one week before operation. Post operative patients were followed up at regular intervals. Pure tone audiogram (PTA) was done after 8 weeks and hearing assessment was compared by closure of air bone gap.&#x0D; Results: In this study majority of patients were within 13-17 years in child group and 18- 35years in adult group. Most of patients were male.Closure of air-bone gap was significantly higher in adults. Improvement of hearing status was more in adults.&#x0D; Conclusion: CWD mastoidectomy with tympanoplasty not only lowers recurrence rate but also improves hearing status although less likely in child and younger age group than adults.&#x0D; Bangladesh J Otorhinolaryngol; April 2017; 23(1): 52-58

Audit of Outcomes of Endoscopic Cholesteatoma Ear Surgery

Background: The objective of cholesteatoma surgery is not only to eradicate disease, but also reduce the risk of recurrence. While the use of the endoscope has been shown to reduce the rate of residual disease, there is currently insufficient data on recidivism and hearing outcomes following exclusive endoscopic use in cholesteatoma ear surgery. Objectives: Auditing outcomes of exclusive endoscopic surgery (EES) for the surgical management of cholesteatoma, with a secondary aim of comparing recidivism and hearing outcomes of 4 different surgical techniques, namely, EES, microscopic canal wall down (CWD), microscopic canal wall up (CWU) and combined endoscopic-microscopic techniques (CEM). Methods: A retrospective chart review was conducted at two tertiary academic hospitals in Cape Town, namely, Red Cross War Memorial Children’s Hospital (RCWMH) for patients below13 years and Groote Schuur Hospital (GSH) for patients above 13 years, over a 5 year period, between January 2012 and December 2016. Results: 128 cholesteatoma surgeries overall; 110 patients were from GSH and 18 from RCWMH. Eight RCWMH patients underwent EES, 7 had CWU, 2 had CWD and 1 underwent CEM. Overall recidivism in the RCWMH population was 33% (6/18), 2 underwent EES, 2 underwent a microscopic CWU, 1 had a CWD and 1 underwent CEM. The mean postoperative hearing in this group was 40 dB from 50.3 decibels (dB) preoperatively. In the GSH group, 23 underwent an EES, 42 had a CWU, 40 underwent CWD and 5 underwent CEM. Overall recidivism for the GSH group was 17% (19/110). Of those, 7 underwent EES, 8 underwent microscopic CWU, 1 underwent CWD and 3 underwent CEM. Mean postoperative hearing was 47.4 dB from 48.4 dB preoperatively. Conclusions: The CWD technique demonstrated superior outcomes. In the GSH group, the EES approach had the same recurrence rate as CWU. Much higher recidivism was observed in the RCWMH group. Management of cholesteatoma requires a highly individualized approach to determine the most appropriate surgical treatment paradigm.

Human Tonsil-Derived Mesenchymal Stem Cells-Loaded Hydroxyapatite-Chitosan Patch for Mastoid Obliteration.

Canal wall down (CWD) mastoidectomy is a surgical procedure that is essential to eradicate chronic ear diseases but results into bone defects due to the resulting mastoid cavity. This study investigated the ability of human tonsil-derived mesenchymal stem cells (hTMSCs) combined with a hydroxyapatite (HAp)-chitosan patch to promote osteogenesis in the treatment of postoperative temporal bone defects using an animal model. At 12 weeks postsurgery, the obliteration ratio and bone formation in the tympanic bulla of rats that were grafted with hTMSCs and a hydroxyapatite (HAp)-chitosan patch or not were compared using histopathological observation and computed tomography (CT) imaging. The group of rats that was administered the Patch group and the group of rats that was administered hTMSCs + Patch group both showed significantly remarkable obliteration ratios and bone formation compared with the Sham and hTMSCs groups. Moreover, the hTMSCs + Patch group showed bone formation in both the periphery and the central region of the tympanic bulla cavity, indicating prominently enhanced osteogenesis compared to the Patch group. Altogether, the results showed that combining hTMSCs with a HAp-chitosan patch accelerated osteogenesis for reconstruction of postoperative temporal bone defects. These findings demonstrate that the hTMSCs + Patch scaffolds are promising for treatment of the bone defects in the tissue engineering.

Repair effect of xenogeneic acellular dermal matrix during external auditory canal reconstruction after canal wall down mastoidectomy

Background: In some cases, there is insufficient external auditory canal (EAC) skin to cover the reconstructed canal wall after canal wall down (CWD) mastoidectomy. Acellular dermal matrix (ADM) can help to repair the skin, mucosa and other epidermal tissue defects.Aims: To investigate the repair effect of xenogeneic ADM (xeno-ADM) for EAC skin defects.Material and Methods: We retrospectively analyzed 28 patients who underwent open mastoidectomy combined with canal wall reconstruction and mastoid obliteration in our hospital. The xeno-ADM was used to repair the EAC skin defect. The epithelialization time, dressing change times, complications and hearing improvement post-operation were summarized and analyzed.Results: Reasons for using xeno-ADM included: 11 (39.3%) cases suffered from extensive middle ear cholesteatoma, three (10.7%) cases suffered from advanced EAC cholesteatoma, eight (28.6%) cases to solve the cavity-related problems, and six (21.4%) patients had a narrow EAC. The postoperative epithelialization time was 5.8 ± 1.6 weeks, and the number of dressing changes was 4.8 ± 1.6 times. There was no xeno-ADM rejection and related complications, the postoperative hearing improvement was statistically significant (p = .013).Conclusions and Significance: Xeno-ADM could be a safe, effective and simple method for repairing skin defect in the reconstruction of EAC after CWD mastoidectomy.

Usefulness of Anterior-Based Periosteal (Palva) Flap for Obliteration of Mastoid Cavity in Canal Wall Down Mastoidectomy

Usefulness of Anterior-Based Periosteal (Palva) Flap for Obliteration of Mastoid Cavity in Canal Wall Down Mastoidectomy

Chronic Draining Ear and Cholesteatoma Recidivism: A Retrospection from Clinical, Imaging, and Surgical Perspectives.

To evaluate the reasons for persistent draining ear and cholesteatoma recidivism following canal wall down (CWD) tympanomastoidectomy by studying the sensitivity of high-resolution computed tomography (HRCT) scanning in different potential etiologies, corroborating through appropriate surgical intervention, and thereby, to suggest proper preventive measures. In this observational study, 32 chronic, refractory draining ears were subjected to revision surgery following a radical or a modified radical mastoidectomy. Besides disease (cholesteatoma/granulations) eradication, pitfalls of the primary surgeries were addressed. Data were interpreted for studying the epidemiologic profile, the clinical presentation at recurrence, the type of primary surgery, the sites of recidivism, the probable causes, and the best possible management at revision. Of the 32 patients/ears, 23 had residual/recurrent cholesteatoma. Major reasons were inadequate disease clearance, contracted/inadequate conchomeatoplasty, no cavity obliteration, and inappropriate bone work. HRCT predicted persistent bridge and lateral semicircular canal dehiscence with 100%, and ossicular integrity and bony overhang with >80% sensitivity. Sinus tympani and oval window niche were the commonest sites of recurrence. At revision, radical/modified radical mastoidectomies were associated with cavity obliteration and appropriate revision of conchomeatoplasty in 28 patients. Recurrence of cholesteatoma/granulations is an important cause for chronic drainage from post-CWD cavities. Revision surgery explores the surgical pitfalls, and ensures clearance of disease from hidden areas, adequate bone work, and optimum conchomeatoplasty following cavity obliteration to provide a safe, dry ear with hearing improvement whenever feasible.

Anterior Attico-antrostomy with Cortical Mastoidectomy and Attic Reconstruction with or without Ossiculoplasty Versus Canal Wall Down Mastoidectomy with Ossiculotympanoplasty using Tragal Cartilage sh

Anterior Attico-antrostomy with Cortical Mastoidectomy and Attic Reconstruction with or without Ossiculoplasty Versus Canal Wall Down Mastoidectomy with Ossiculotympanoplasty using Tragal Cartilage sh

Evaluation of middle ear risk index in patients undergoing tympanoplasty.

Tympanoplasty is a standard surgical procedure for the treatment of chronic otitis media. In this study, we aimed to determine the effect of the predictive factors of middle ear risk index (MERI) in patients undergoing tympanoplasty. A total of 200 patients who underwent tympanoplasty surgery from 2008 to 2018 at Khalili hospital in Shiraz were evaluated. In this study, variables such as age, sex, systemic diseases (diabetes mellitus, hypertension), location and size of tympanic membrane perforation (TMP), health of the opposite ear, dryness duration of the ear, presence or absence of myringosclerosis during surgery, type of operation and the risk of MERI were evaluated. The success rate for a 6-month follow-up of patients was 88%. Results showed that there was a significant difference between the MERI scores and the three types of operation of intact canal wall (ICW), canal wall down (CWD) and non mastoidectomy (P < 0.001). The longer the dryness duration of the ear, the MERI score was lower. When MERI score is low, the patient doesn't need mastoidectomy. Also, the worse the opposite ear, the higher the MERI score was. The highest MERI score was in patients undergoing CWD, and the lowest MERI score was in patients undergoing simple tympanoplasty. MERI score is a useful tool for predicting the success rate of tympanoplasty and helps the surgeon planning the type of tympanoplasty.

Pre and intraoperative findings of chronic otitis media

Chronic otitis media (COM) is still highly prevalent in developing countries and often become main cause of deafness and morbid complication. Appropriate management may decrease the morbidity and mortality rate. The aim of the study are to evaluate preoperative and intraoperative finding among COM patients. A descriptive study was conducted at Mohammad Hoesin Hospital Palembang from April 2015 to April 2018. A secondary data was taken from medical records. A total of 252 patients were included in this study with the highest incidence was at 21-30 years old group (29,36 %) with male predominance. The most frequent preoperative assessment were total perforation of tympanic membrane in 104 patients (41.26 %), moderately severe mixed hearing loss in 61 patients (24,2%), and mastoiditis with cholesteatoma in computed tomography (CT) finding in 158 patients (62,69 %). In intraoperative finding, there were 202 patients (80,15%) with cholesteatoma whereas 103 patients (40,87 %) with granulation tissue. Ossicular chain destruction were found in 141 patients (55,95 %). Canal Wall Down Mastoidectomy (CWD) were performed in 190 patients (75,39 %). The prevalence of COM with cholesteatoma at Mohammad Hoesin hospital is still high. Operative management using CWD technique is preferred in cases of COM with cholesteatoma.

A Clinical Study on Audiological Evaluation in Patients with Active Squamous Variety of Chronic Otitis Media Following Canal Wall Down Mastoidectomy with Ossicular Reconstruction.

To evaluate hearing results following canal wall down mastoidectomy with ossicular reconstruction for Chronic Suppurative Otitis Media of Active Squamosal variety & evaluate various factors related to surgery impacting hearing results. This prospective study involves 40 patients of active squamosal variety of chronic otitis media who attended ENT OPD and underwent canal wall down mastoidectomy with ossiculoplasty during the period from November 2014 to October 2015. All the patients were subjected to pre and 3months post-op hearing assessment. Based on the hearing outcome, we expressed our study results into two groups, those with statistically significant improvement after surgery (T1) and those whose hearing got worsened or remained the same (T2). The mean post operative hearing gain of patients was 5.25 ± 7.30dB, The median post-op hearing gain was 5.20dB. Mean pre-operative hearing loss (AB gap) was 41.28dB. Mean post-operative hearing loss (AB gap) was 36.24 with the average 3months post-operative hearing gain was 5.2dB, which reflects a definite improvement. There is a statistically significant hearing improvement (with an average of 5.2dB AB gap closure) following Canal Wall Down Mastoidectomy with ossiculoplasty as established in the study.

External Auditory Canal Reconstruction and Mastoid Obliteration Using Modified Palva Flap in Canal Wall Down Mastoidectomy With Tympanoplasty.

To evaluate the effectiveness of a modified Palva flap used for external auditory canal reconstruction and mastoid obliteration in canal wall down mastoidectomy. We retrospectively analyzed patients who underwent canal wall down mastoidectomy with tympanoplasty using modified Palva flap. All patients underwent pure tone audiometry and temporal bone computed tomography (CT) before surgery, and the same tests were performed in the first year after surgery. The external auditory canal volumes were calculated by summing the areas of each section selected in temporal bone CT. For each patient, the ratio of external auditory canal volume was calculated from CT taken before and after surgery. The mean of external auditory canal volume after canal wall down with a modified Palva flap was about 1.4 times larger than before surgery. The modified Palva flap is effective for the reconstruction of the external auditory canal. Both pure tone audiometry level and air-bone gap showed statistically significant improvement after surgery ( Ps = .001 and .002, respectively). The external auditory canal volume slightly increased, but the status of mastoid obliteration was well maintained 1 year after surgery. The modified Palva flap used in this study is an easy and effective method in external auditory canal reconstruction and mastoid obliteration.

Use of Biodesign® Otologic Graft in Canal Wall Down Mastoidectomy: A Prospective, Randomized Trial

Use of Biodesign® Otologic Graft in Canal Wall Down Mastoidectomy: A Prospective, Randomized Trial