Wednesday 27 January 2016

Endoscopic Fat graft myringoplasty


ENDOSCOPIC FAT GRAFT MYRINGOPLASTY WITH EVICEL(SEALANT) APPLICATIONS
DR.K.K.DESARDA
A prospective study at KEM Hospital Pune
Abstract:
The aim of endoscopic fat graft myringoplasty (FGM) under local anaesthesia  clinical trial was to evaluate the success rate of our newly developed surgical technique We also aimed to assess the correlations between the size of perforations and closure rates, as well as the results of re-gained hearing in successful cases with respect to sizes of perforations. Fifty consecutive patients with persistent tympanic membrane perforation were included in this study. All patients underwent  endoscopic fat graft myringoplasty with evicel (Human selant fibrin glue)  .application.  Treatment success was defined as an intact and mobile tympanic membrane (TM) at the 3-month follow-up visit. Bone conduction (BC) and air conduction (AC) thresholds at the frequencies of 0.5, 1, 2, 3, and 4 kHz were recorded preoperatively and at the 3rd month postoperatively.
The fat graft tympanoplasty can be performed under local anesthesia . The harvesting of the graft is very quick and there is no visible scar and minimum donor site morbidity.  It avoids extensive middle ear manipulation.  It is a safe and simple procedure for the closure of a dry, small central perforation.  Its success rate is as good as tympanoplasty using temporalis fascia or perichondrium.The success rate is 98 to 100% for small central perforations.A fat graft myringoplasty achieves its highest success rate in perforations smaller than 30% of the pars tensa.We strongly recommend the endoscopic fat graft myringoplasty procedures  for small central perforations which achieves 98% graft take up with 15 db air bone gap closure.

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Key Features:   Endoscope,fat graft, evicel sealant glue,.myringoplasty
INTRODUCTION:
  A prospective clinical study of  endoscopic fat graft myringoplasty  for small  central tympanic membrane perforations due to: trauma, infection, post-tympanostomy tube extraction and post myringoplasty residual perforations was carried out at KEM  and Sahyadri speciality Hospital Pune during 2014 to 2015. Fifty cases of fat graft myringoplasties were done using evicel selant ( J & J co. ltd ) application .The post op results were excellent about (98%) were analysed.Temporalis fascia  and  perichondrium  use to be the most common grafts being used in closure of the tympanic perforations.   However for a dry, small central perforation the adipose tissue fat is a good alternative. 
 A myringoplasty is one of the most common operations performed in Otosurgery, due to the high incidence of tympanic membrane perforation.  The first attempt to close the tympanic perforation was done by Banzer in 1640 who inserted a small tube of elkhorn covered with pig’s bladder.1  Berthold in 1878 used a full-thickness free skin graft for tympanic membrane closure.2  Ringenberg used a fat tympanoplasty for the first time for the closure of a small tympanic perforation.
 The fat graft tissue tympanoplasty has certain advantages as this procedure can be done in an office basis or on an outpatient basis. The patient goes home on the same day. There is very limited postoperative care.  Fat can be harvested in a very short time and it avoids invasive extensive surgical manipulation of the middle ear.  It avoids general anesthesia and is very safe for a dry, small, central perforation.  It is a simple and cost effective technique in managing small tympanic membrane perforation and the success rate of a fat-plug myringoplasty is comparable with the results of temporalis fascia tympanoplasty.
Fifty patients aged between 20 to 55 years; with fat graft myringoplasty were operated endoscopically for closure of tympanic membrane perforation at KEM  and Sahyadri speciality Hospital Pune during 2014 to 2015 under local anaesthesia Follow up visits for tympanic membrane evaluation, were in the 1, 3, 6 and 12th post-operative months. Failure cases were counted at the end of the 1st month post-operatively. Hearing evaluation was done pre-operatively and in the 4th postoperative month. Closure of the air bone gap was the parameter of hearing improvement. The outcome measures were the post-operative state of tympanic membrane, hearing improvement in closure of the air-bone gap and incidence of failures and complications.Three groups of the patients were selected for fat graft myringoplasty procedure The groups included. Were residual perforation,traumatic perforations and post grommet extrusion perforations.All perforations were small central type with minimum conductive hearing loss.  
 The Mean operative time was 30 minutes. No side effects or operative complication occurred during the procedure.The successful procedures were (98%) from the entire patient group. Post-operatively, the mean improvement in the air/bone gap was about 15 dB for the successful cases.
Materials  and  Methods:
A retrospective study was done in the Department of Otorhinolaryngology, KEM and Sahyadry Hospital Pune during 2014 to 2015, to evaluate myringoplasty using only fat (adipose tissue) to close the eardrum perforation.    All the surgeries were done by the first author.  A total of 50 cases that underwent consequent fat-plug myringoplasty were included in the study.  30 adult male and 20 female patients were selected for this procedure under local anaesthesia.The children age group was excluded from this study because of their recurrent URTI and Eustachian tube dysfunction.
  The perforation was situated in the anterior inferior quadrant in twenty cases,and posterior inferior quadrant in thirty cases . The criteria for the small perforation was that the size of the perforation be approximately 5 by 5 mm or 25  to 30%  of the drum's surface .Free fat grafts have been known to reduce in size during long-term follow up. This is the reason why the grafts used were approximately two times larger than the size of the perforation. In this study subtotal and total perforations were excluded. The subsequent otoendoscopic evaluation revealed closure of the perforation which was considered as successful criteria for a fat-graft myringoplasty.  The subsequent post.op. audiometric evaluations were done and compared with pre.op.audiometrtic profie which revealed closure of AB gap bt 15db.
  Surgical Technique:
  Endoscopic Transcanal transtympanic approach without raising
  tympanomeatal flap:
  Graft Harvesting:
The ear lobe was infiltrated using 2% lidocaine with 1:200,000 adrenaline and a 5 mm incision was made at the medial surface of the tip of the ear lobe with no. 15 blade. The skin was undermined and an amount of fat as twice as the size of the perforation was harvested in one piece and was put in a sterile saline solution. The incision was closed by one or two 5–0 absorbable sutures(Fig.1)
With 4 mm zero degree endoscopic  vision, the edges of perforation were freshened. The middle ear was filled with antibiotic soaked gelfoam.The fat was trimmed at an approximately twice the size of the perforation or lesser. It was placed over the perforation and plugged in it as an hourglass through the perforation using a pick or blunt needle. The lateral fat bulge should not be too high to help epithelial closure of the perforation. Oversized fat plug may cause a tear in the tympanic membrane or overstretching of the perforation margins leading to atrophy or necrosis later on. Undersized fat plug should be avoided to prevent dehiscence in grafting .The graft was kept humidified by pieces of gelfoam upon and around the outer portion of the fat and stabilized by using a thin film of evicel selant (human fibrin glue) covering the tympanic membrane. The external ear was filled with pieces of gelfoam soaked with local antibiotic drops  The external ear opening is sealed with a merocel ear pack. No ear dressing was used. The merocel pack was removed after 48 hrs.

                       The sequential pictures of fat graft myringoplasty:


Fig.1       Fat graft harvesting from post.surface of ear lobule.





Fig.2  Endoscopically  freshening of edges of perforation of Small CP

                                                          Small cenral perforation
                                
                                                      Freshening the edges

                                                     Removal of perforation ring      
        
post excision of perforation                                                              



Fig.3                 Endoscopically  Fat plugging of the perforation

         



Fig .4                        Gelfoam packing & Evicel glue application

                                                           Geifoam packing     
                                         
                                                  Evicel sealant application


  
Fig.5.        Endoscopic  fat graft  pictures pre & post  operation after 8 wks
                
A)      Pre op central perforation.          B) post op fat graft  as neotympanum
                                                                    
           The clinical criteria established by Fiorino and Barbieri for admission to fat
            graft myringoplasty

1. Period of time elapsed from previous surgery equal to or longer than 6 months.
2. Perforation of the pars tensa no larger than 5 mm.
3. Non-marginal localization, i.e. not involving the annulus or exposing the
    malleus handle.
4. Absence of calcific plaques or atrophic areas adjacent to the perforation.
5. Normal appearance of mucosa in the tympanic cavity.
6. Absence of any acute inflammation.
7. Absence of middle ear discharge in last 3 months.
8. No evidence of cholesteatoma.
9. No planned ossicular reconstruction.
10. Absence of major Eustachian tube dysfunction.






 Results

Fifty patients were included in this endoscopic study,  fourty two  patients had unilateral, while eight patients had bilateral perforations.who had fat graft myringoplasty. The eight bilateral perforation cases were all due to post-long term tympanostomy tube extraction and the selection of which ear to be operated upon was the ear with a larger air bone gap. If both air bone gaps are equal, the larger perforation was operated first. The second ear was operated upon after 3 months of complete healing of the 1st ear.
There was no side effect or complication at the time of the procedures. The mean operative time for the procedure counted from the beginning of the marginal refreshing of the perforation to closure of external ear canal by merocel pack was 30 min.
Fat graft myringoplasty procedure has a minimal technique failure especially if the selection criteria were applied to the patients for this surgery. All cases had evicel selant(Fibrin glue ) application for graft take up.The graft take up was 98% in all cases and failure cases  were 4%.The advantages of fat graft include: It does not need support from the middle ear side to prevent collapse like underlay grafts especially at the area near the anterior annulus.



Discussion
Ringenberg first described FM, with a success rate of 87% for small perforations. [Since then, studies have shown success rates ranging from 85% to 92% in cases of small perforations.  Deddens et al. had reported that size of TM perforation was a crucial factor. Perforations, in their series, were 5-30% of the drum surface, which was a good prognostic factor for an FM as compared to larger perforations for fat graft alone as was also observed by us. 

The fat graft can be harvested from the abdomen, buttock and ear lobule. The ear lobule fat harvesting is much simpler as it is done from the same sterile area of the surgical field prepared for the fat tympanoplasy and its scar is almost invisible. The fat of ear lobule is denser with big revascularization activity and acts as a good template for mucosal and epithelial growth.  There is significant bulging postoperatively on the TM till the end of the 3 rd month and after that it progressively disappears and gets converted into a smooth sclerotic area on the TM at the 5 thmonth .  This phenomenon was also observed by us in patients where graft uptake was there. There are two histological theories of fat grafts."The host cell replacement theory" of Neuhof and "The cell survival theory" of Peer. The host cell replacement theory states that all the original cells die and are totally replaced by new wondering adipocytes or by fibroblasts. The cell survival theory states that not all the original adipose cells die. Those fat cells which receive adequate blood supply survive whereas remaining degenerate, thus explaining loss of volume. The transplanted fat cells are not replaced by scar tissue, instead a connective tissue capsule outside the fat graft begins 3 weeks after transplantation, which becomes progressively thinner over the course of a year. Fat tissue provides the basic requirement for the grafting of the TM with its own favorable characteristics. 




The  transcanal approach seems to be safer for the patient in comparison to the classic myringoplasty techniques since no manipulations of the middle ear are performed and the related complications are avoided. Fat is not the only material used when the tympanic membrane is approached via the external auditory meatus but it is somewhat easy to harvest and handle. Dursun et  compared the effectiveness of perichondrium and fat in repairs of perforations smaller than 3mm in 30 patients and found no statistically significant differences in the use of the two techniques. In fat subgroups, 2mm and 3mm perforations had an 90% success rate and 1mm perforations a 100% success rate again equal to the perichondrium results
 Free fat grafts have been known to reduce in size during long-term follow up. This is the reason why the grafts used were approximately two times larger than the size of the perforation. Nishimura et observed in an experimental study that apoptotic cells were present 30 days after transplantation.
Although fat graft myringoplasty is a simple, safe and cost-effective procedure, it has been underused despite its numerous advantages.7 However, it cannot be always an alternative procedure to the classic surgical myringoplasty in every tympanic membrane perforation. Certain clinical criteria should be fulfilled and applied for the perforation to have the highest possibility of this procedure’s success
 The clinical criteria established by Fiorino and Barbieri for admission to fat graft myringoplasty were sufficient for the selection of patients eligible for this procedure ..
The first utilization of fat plug myringoplasty was reported by Ringenberg8 with the success rate of 90%. In the following studies the success rate was ranging from 80% to 92% in cases of small perforations including primary procedures. In this study, the success rate of the entire group of patients was 98%.
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The failure rate for this study was 4 out of 50 ears (8%) with a mean air bone gap of 10 dB and the causes were due to infection, detached fat graft and dehiscence due to undersized grafts. Fiorino and Barbieri  attributed the failure causes to: immediate failures due to technical difficulties such as anterior perforations, inadequate graft support, poor vascular supply or infection; and delayed failures due to tympanic membrane atrophy, infections or Eustachian tube dysfunction. Fat graft myringoplasty procedure has a minimal technique failure especially if the selection criteria were applied to the patients for this surgery. All cases had evicel selant(Fibrin glue ) application for graft take up.
Local anaesthesia was used in most of the literature as the procedure is easy, simple, fast and minimally invasive. 
In this study, the traumatic, the tubotympanic chronic otitis media, the post tympanostomy tube extraction perforation groups were operated upon after 3 months of dryness and failure of closure, while the post myringoplasty residual perforation cases were operated upon after 6 months of failure of closure.
Technical operative points during fat grafting (such as graft size in the perforation, degree of lateral bulge of the fat plug and moistening of the lateral side of the graft are also considered to be important factors of success in the fat grafting procedure.
Fat is also an active material containing angiogenic and survival factors e.g. Monobutyrin, prostaglandins, interleukins 1 and 6, cytokines and tumour necrosis factor which, stimulate restoration and repair of the fibrous layer and promote revascularization which are both essential for survival of the free flap. Fat graft promotes growth factors including vascular endothelial growth factor, transforming growth factor beta, platelet derived growth factor and fibroblast growth factor which promote the process of the tissue repair. Fat contains high population of multipotent cells referred as adipose-derived stem cells which are similar in activity to those of the bone marrow derived mesenchymal stem cells in the ability to differentiate into mesenchymal tissues such as endothelial and fibrous types promoting the healing process of the tympanic membrane.



Conclusion

Fat graft myringoplasty is an easy, simple, fast and minimally invasive procedure for the repair of small tympanic membrane perforations with favourable hearing results. It can be performed under local . It can be done for small tympanic membrane perforations due to: trauma, infection, post  tympanostomy tube extraction and post myringoplasty persistent residual perforations with good success rate without complication
The evicel sealant (Ethicon J&J co.Ltd) applied as thin film gets absorbed in two weeks leaving the neo-tympanum intact because of its adhesive properties.We strongly recommend this  endoscopic fat graft myringoplasty procedures  for small central perforations which achieves 98% graft take up.A fat graft myringoplasty achieves its highest success rate in perforations smaller than 30% of the pars tensa. Tympanosclerosis should not be a contraindication for fat grafting.


References
1.Ringenberg JC. Fat graft tympanoplasty.  Laryngoscope. 1962;72:188-192
2.Sterkers JM. Ultra-thin adipogenic graft for tympanoplasty (obtained by crushing subcutaneous adipose tissue under pressure) [in French].  Ann Otolaryngol Chir Cervicofac. 1964;81:265-270
PubMed
3,Terry RM, Bellini MJ, Clayton MI, Gandhi AG. Fat graft myringoplasty—a prospective trial.  Clin Otolaryngol Allied Sci. 1988;13(3):227-229
PubMed   |  Link to Article
4.Gross CW, Bassila M, Lazar RH, Long TE, Stagner S. Adipose plug myringoplasty: an alternative to formal myringoplasty techniques in children.  Otolaryngol Head Neck Surg. 1989;101(6):617-620
PubMed
5.Landsberg R, Fishman G, DeRowe A, Berco E, Berger G. Fat graft myringoplasty: results of a long-term follow-up.  J Otolaryngol. 2006;35(1):44-47
PubMed   |  Link to Article
6. Landsberg R, Fishman G, DeRowe A, et al. Fat graft myringoplasty: results of a long-term follow-up. J. Otola
7.Terry RM, Bellini MJ, Clayton MI, et al. Fat graft myringoplasty – a prospective trial. Clin. Otolaryngol. Allied Sci. 1988;13:227–229. [PubMedryngol. 2006;35:44–47. [PubMed]
8.Bertoli GA, Barbaro M, Giangande V, Bava G, Seta ED, Filipo R. Fat graft myringoplasty: An office procedure for the repair of small perfoations of the tympanic membrane. Mediterr J Otol 2007;3:120-5.