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%.
.
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
PubMed   |  Link to Article
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. 

Saturday, 29 August 2015

EFFICASY OF EVICEL( FIBRIN SEALANT- HUMAN) IN COMPOSITE CARTILAGE GRAFT MYRINGOPLASTY. (PROSPECTIVE STUDY)

INTRODUCTION:

Fibrin sealant has been used for many years and has a wide range of clinical applications for suture support, tissue adhesion, and hemostasis. Fibrin sealant imitates the final phase of the blood coagulation process. Fibrinogen is converted to fibrin on a tissue surface by the action of thrombin, which is then cross-linked by factor XIIIa, creating a mechanically stable fibrin network. This fibrin network is thought to reduce the amount of postoperative bleeding by sealing capillary vessels and enabling raw operative surfaces of cartilage graft to adhere. The potential advantages of the use of such substances include prevention of hematoma, reduction in surgical time, reduction in flap edema, and shorter recovery time andexcellent healing. The physiologic mechanism that creates fibrin sealant was first described by Morawitz in 1905.

 We have reviewed the world literature to find out if any study in micro-ear surgery is done but could not find any confirmed study. Ours is the first pilat study to know the efficacy of evicel sealant in reconstructive tympanoplasty. Fibrin glue was originally described in 1970 and is formed by polymerizing fibrinogen with thrombin and calcium.2 It was originally prepared using donor plasma; however, because of the low concentration of fibrinogen in plasma, the stability and quality of the fibrin glue were low.3 Commercially pretreated fibrin sealant products were developed to increase the efficacy of forming a stable clot.These products are heat treated, which greatly reduces the risk of disease transmission. The fibrin sealant and delivery system are easy to store and rapid to construct, and, therefore, have enjoyed some use in  reconstructive tympanoplasty and cosmetic surgery.

Fibrin sealant (human) (Evicel; Johnson & Johnson– Wound Management, Somerville, New Jersey) is a plasma cryoprecipitate-based sealant that consists of 2 components: (1) biological active component–2 (BAC2), also called human clottable protein, which consists predominantly of fibrinogen and (2) thrombin. BAC2, a concentrated solution of clottable plasma proteins, consists mainly of fibrinogen and other proteins. The thrombin solution contains highly purified human thrombin and calcium chloride for activation of clotting of the final combined product. Thrombin is a highly specific protease that transforms the fibrinogen contained in BAC2 into fibrin. Fibrin sealant (human) (Evicel; Johnson & Johnson– Wound Management, Somerville, New Jersey) is a plasma cryoprecipitate-based sealant that consists of 2 components: (1) biological active component–2 (BAC2), also called human clottable protein, which consists predominantly of fibrinogen and (2) thrombin. BAC2, a concentrated solution of clottable plasma proteins, consists mainly of fibrinogen and other proteins. The thrombin solution contains highly purified human thrombin and calcium chloride for activation of clotting of the final combined product. Thrombin is a highly specific protease that transforms the fibrinogen contained in BAC2 into fibrin. It is indicated as supportive treatment in patients undergoing reconstructive tympanoplasty.

ABOUT EVICEL SEALANT:

u  Thaws within 10 minutes at 37°C (and must not be kept at this temperature for longer than 10 minutes); within 1 hour at 20°C to 25°C (room temperature); or within 1 day at 2°C to 8°C (refrigerator). Once thawed, EVICEL® must not be refrozen. Once at room temperature, EVICEL® must not be refrigerated
u  All-Human formulation – EVICEL® Fibrin Sealant does not contain aprotinin or bovine derivatives and does not expose patients to the risks associated with aprotinin264
u  Multiple, clog-resistant tip options – Standard 6 cm tip or 35 cm Rigid or 45 cm Flexible tip.

IMPORTANT RISK INFORMATION:

u  Do not inject directly into the circulatory system. Intravascular application of EVICEL® may result in life-threatening thromboembolic events.
u  Do not use in individuals known to have anaphylactic or severe systemic reaction to human blood products.
u  Do not use for the treatment of severe or brisk arterial bleeding
            Most common adverse events reported in clinical trials (=5%) are bradycardia,  
            nausea, hypokalemia, insomnia, hypotension, pyrexia, graft infection, vascular  
            graft occlusion, peripheral edema, and constipation.


                             
Evicel is provided as a single-use human surgical sealant kit consisting of 2 packages, the first containing 1 vial each of frozen sterile solutions of BAC2 (Biological Active Componant 2) and thrombin and the second containing the sterile application device. It is the only totally human protein–derived, bovine-free fibrin sealant commercially available in the United States. The unit cost for 2 mL of fibrin sealant plus the applicator is $200(1Rs.12000). The vials are stored in a freezer; when removed and thawed, they are stable for 24 hours. The vials are readily thawed in 5 minutes without the use of a rapid-warming device. After the BAC2 and thrombin solutions are thawed, they are drawn into a unique trilumenal (2 syringe lumens and 1 air lumen for spraying) catheter application device. As the plungers are depressed simultaneously, the solutions are mixed by the applicator and sprayed into the operative site.

The applicator gently sprays the fibrin sealant into the operative wound as a thin layer and, therefore, allows a relatively small volume (1 mL) of sealant to be delivered evenly. The solutions mix as they exit the catheter during administration, are applied topically by dripping and once applied are transparent. The reconstituted preparation mimics the final steps in physiologic coagulation. Fibrinogen is converted to fibrin on the wound surface in presence of calcium ions by the actions of thrombin and factor XIII, all derived from human plasma. A stable cross-linked fibrin clot is formed over the neotympanum.

Recently we have done 50 cases of type one tympanoplasties with inlay composite cartilage graft. After the surgical procedure is over the evicel (1.5 ml) solution is applied over the surface of the graft material by the evicel triluminal applicator and it was kept for over 3 to 5 minutes to form a solid layer over the neotympanum. So far 50 casers being treated with this technique and found to be excellent in graft take up (98%) and without medialization or lateralization . No complications encountered during evicel application. Graft take was 98% post operatively. More study will be required for its efficacy in reconstructive tympanoplasty.We plan to do more cases with varied middle ear pathology like ossiculoplasty, ossiousplasty ( Bony defect reconstruction as attic, defect, PSQ defect and canal wall defect. Its effect on graft fixing is very encouraging which inspired us to take up this study in middle ear reconstruction.

RESULTS:

u  The results were evaluated in the form of graft uptake, hearing outcome and complications.
u  Healed neo-tympanic membrane, which moves on seigelization was taken as successful graft take-up, while any residual perforations or retraction of neo-tympanum were taken as failures.
u  Postoperative and preoperative pure-tone audiograms were compared. Hearing gain and mean residual gaps were evaluated in speech frequencies of 500, 1000, and 2000 Hz.

ADVANTAGES:

u  Reduction in the graft displacement as a cause of failure
u  Ease of use. Comes with the application device and is easy to set up and ready to use.
u  Works on all types of grafts so your primary surgery does not need any alterations.
u  Application takes just an extra few minutes at the end of the surgery.

      DRAWBACKS

u  Need for a longer study with more number of cases to prove its statistical significance
u  Affordability and Availability of the fibrin sealant.






TO SUMMURIZE:


u  A failure rate of around 10 % for a type 1 Tympanoplasty is still high by today’s standards.
u  The pilot study shows promising results.
u  Encourage ENT surgeons to use a fibrin sealant and publish your results and feedback regarding the same.



Tuesday, 21 April 2015

Robotic Surgery Applications in Otolaryngology & HNS An Emerging Wave.

Robotic surgery Applications in Otolaryngology & HNS

An Emerging Wave.

 

Introduction:
A role of Robotic surgery technology in otolaryngology is beginning to emerge, particularly where precision is required or visualization is limited, and there are a number of pioneering contributions. The first otolaryngologic application of robotics occurred as early as 2002 with several reports from the Terris group at the Medical College of Georgia exploring endoscopic neck procedures.7-10 The first human application was described by McLeod and Melder11 with a case report of excision of a vallecular cyst. Hockstein and colleagues further pursued oral and oropharyngeal applications of robotic technology with a stepwise experimental approach.12,13 Finally, interest in robotic skull base surgery has emerged with the work of Hanna and colleagues.14

Experimental Origins

The first use of robotics for otolaryngologic applications was explored in a porcine model of neck surgery that included parotidectomy, submandibular gland resection, and selective neck dissection.8 This work built on previous promising findings for totally endoscopic neck surgery (also described by Terris and collaborators15,16) and provided proof of principle, in that the safety and efficacy of endorobotic neck surgery was demonstrated, and quickly established that advantages in duration of surgery could be easily achieved with the addition of robotic technology.

Robotic-assisted surgery is poised to become a standard technique for many head and neck surgical procedures, according to experts. Robotics has already been approved for prostate surgery, heart surgery, gastric bypass, and hysterectomy. If preliminary results in early studies of some head and neck surgical procedures are borne out, transoral robotic surgery (TORS) should also be approved by the FDA
The purpose of these studies was to learn how to position the da Vinci arms in a patient's mouth, Dr. weinstein described robotic-assisted procedures as follows: the surgeon sits at a console where the surgical field is displayed in high-quality, three-dimensional video, and small joysticks are used to control the robotic arms. The patient is positioned remotely, approximately 10 feet away.



Figure.Transoral robotic surgery, offering a three-dimensional visual environment, is being studied for use in a number of head and neck procedures.
U

TYPES OF PROCEDURES

Several types of head and neck surgical procedures are amenable to robotic-assisted surgery. Robotics can be used to resect benign and malignant tumors of the oral cavity, including the pharynx and larynx, tonsil, tongue base, supraglottis, glottis, pyriform sinus, and the parapharyngeal space.
Transoral robotic surgery is presently ideal for cancers or benign tumors of the oropharynx and supraglottis, and this technique is also useful for tumors in the pyriform sinus, but access is more difficult. It should be used for tumors not lower than the vocal cords and not higher than the lower nasopharynx.
Robotic-assisted surgery has a potential use not only for treating benign and malignant tumors, but also for treating inflammatory conditions such as chronic lingual tonsillitis in the back of the tongue. When a patient complains of chronic tongue base tonsillitis that does not respond to antibiotics, it is a real problem for the patient and the surgeon  as it is difficult to remove the tongue base tonsils using standard techniques. At the University of Pennsylvania, preliminary studies in a few patients suggest that robotic-assisted surgery takes only about 15 minutes to remove the tongue base tonsils, and no further infections have been seen with long-term follow-up.

 

BENEFITS TO PATIENTS

The benefits of TORS are numerous, according to surgeons interviewed for this article.
Some tonsil- or tongue-based cancers require large, complex, long operative procedures involving tracheostomy, complex skin reconstruction, and splitting the jaw, Dr. Weinstein explained. Blood transfusions are often required for these large open procedures. Only one patient who underwent TORS at the University of Pennsylvania required a blood transfusion, he commented.
We can avoid tracheostomy, complex skin reconstruction, and jaw splitting with robotics, using one three-hour procedure and then a second procedure for another three hours to take out lymph nodes.
Robotics causes less injury to speech and swallowing structures, and less cosmetic damage, because it is less invasive than open surgery. Also, robotics shortens surgical times from six to 18 hours to two hours. Robotics also allows good control of bleeding. With robotics, we can use both hands for surgical procedures, whereas endoscopic-based procedures are typically done with one hand, because the other hand holds the endoscope.
For other lesions, such as lesions in the supraglottis or larynx, the major advantages of robotics over open surgery are better access and faster surgical times.
Robotics offers a three-dimensional visual environment that puts the surgeon right where the surgery is happening. This unique perspective allows the surgeon to operate at the same level as the anatomy of interest. 'Master' control manipulators then allow the surgeon to use precise instruments in situations and in ways that were never before possible. For instance, the surgeon can rotate a given instrument 540 degrees and overcome the limitations of the human wrist.

LIMITATIONS OF ROBOTIC-ASSISTED SURGERY

One limitation of robotic-assisted surgery, with present techniques, is limited access. Some tumors are located too deep in the laryngopharynx to allow access, Dr. Weinstein said. With current technology, it is difficult to have greater access beyond present boundaries (i.e., tumors not lower than the vocal cords and not higher than the lower nasopharynx), Dr. O'Malley commented.
Also, at present there are no robotic instruments for drilling and removing bone. ENTs use a lot of drills, and it is expected that companies will be developing rongeurs and drills along with the software to drive these tools using the robot.
It would also be desirable to have haptic or tactile feedback with robotics, such as is used by the military. At present, we have to rely on the tremendous three-dimensional visualization for feedback. As we take the surgical robot into new frontiers, such as skull-based surgery, it would be advantageous to have a system for tactile feedback,
According to Dr. Holsinger, at present the CO2 laser is used with endoscopy to resect tumors and develop planes, but this has limitations. The ideal technique would combine the precise tissue handling properties of the CO2 laser with robotics. Research efforts are aimed at trying to find an optimal laser to combine with robotics, he said.

TRAINING FOR ROBOTIC-ASSISTED SURGERY

The first workshop and formal educational program in robotics for head and neck was taught by Drs. Weinstein and O'Malley at the Intuitive Surgery Training Facility in California. That course included a core group of 12 head and neck surgeons from several institutions, including the Mayo Clinic, M. D. Anderson Cancer Center, and Mount. Sinai Medical Center. These individuals, including Dr. Holsinger, have now gone back to their respective institutions to initiate IRB-approved studies of TORS. Drs. Weinstein and O'Malley are conducting an IRB-approved study at the University of Pennsylvania that is still open. Thus far, 120 patients have entered the trial, and only two of them had anatomy that was inaccessible for a robotic-assisted procedure.
If TORS gains FDA approval based on these studies, the University of Pennsylvania will offer a training course in robotics procedures. The plan is to have a two-day course, with one day in the laboratory and another day of observation. Other institutions will undoubtedly offer courses in robotics as well.
The University of Pennsylvania also plans to erect a special building for research and training in robotics, Dr. O'Malley said. We hope that the people we trained [at the first training session last year] will set up their own programs and spread the seed-establishing more research and developing new procedures and applications, he added.

THE FUTURE OF ROBOTICS

In the future, it would be ideal to have smaller instruments to allow deeper access beyond presently defined boundaries, Dr. Weinstein said. Smaller instruments will be developed to allow access to the nasal cavity as an alternative to endoscopic surgery.
While the first TORS skull base surgery cases have been reported from the University of Pennsylvania, further miniaturization of instruments and more flexible instruments, tactile feedback, and techniques for skull based procedures will probably be developed.
 Dr. O'Malley saidtransoral approaches through the nose to the skull base are being studied in the cadaver model using robotic-assisted techniques. If skull base procedures can be done with robotics, surgery could carry much less morbidity.
Another pressing need, according to Dr. O'Malley, is two-handed, delicate, fine magnification procedures for the vocal cords or subglottis, which may also be applicable to skull base surgery. The technology is not there yet, but it should be in the next five or 10 years. The team at the University of Pennsylvania is studying robotic-assisted surgery for skull-based procedures. There is a need to refine and hone instruments for these procedures.
We are just at the beginning of discovering uses for robotics in head and neck surgery, similar to when DOS was the only operating system for computers. At present, robotics allows removal of tumor and provides a bird's eye view in areas that heretofore had difficult transoral access. I don't have a crystal ball, but the types of approaches for robotics will continue to increase dramatically,.It is an incredibly exciting time.
There is unlimited potential for the application of robotics in head and neck surgery, said Dr. O'Malley. He predicted that 80% of the range of types of ENT surgeries will be performed with some aspects of robotics within the next 25 years, including head and neck, ear, sinus, certain cosmetic and skull-based procedures.

Thank you,
Dr.Desarda.K.K.
Emeritus Prof. & Head
Otolaryngology.
KEM Hospital

Pune