Home About us Editorial board Search Ahead of print Current issue Archives Submit article Instructions Subscribe Contacts Login 


 
 Table of Contents  
ORIGINAL ARTICLE
Year : 2015  |  Volume : 28  |  Issue : 4  |  Page : 918-922

Prevalence of complications associated with tympanostomy tube insertion


Department of Otorhinolaryngology, Faculty of Medicine, Menoufia University, Menoufia, Egypt

Date of Submission31-Oct-2014
Date of Acceptance11-Feb-2015
Date of Web Publication12-Jan-2016

Correspondence Address:
Ahmed Ragab
Department of Otorhinolaryngology, Faculty of Medicine, Menoufia University, Menoufia, 32511
Egypt
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/1110-2098.173673

Rights and Permissions
  Abstract 

Objective
This study aimed to evaluate the prevalence and difficulties during surgery of tympanostomy tube (TT) insertion, complications after surgery, and modalities for management.
Background
In view of the high incidence of otitis media with effusion in children and the fact that TT is one of its major treatments, we decided to conduct the present observational study.
Patients and methods
This study included 220 patients with persistent otitis media with effusion after failed medical treatment for 3 months. All patients underwent TT insertion either unilateral or bilateral in 378 operated ears.
Results
There were 198 problems detected in 378 operated ears. The difficulties during insertion of TT were observed in 82 ears. The most common was the thick mucoid discharge (P = 0.10), followed by the narrow external auditory canals (P = 0.005). Early complications were observed in 42 ears. The most common was early otorrhea (P = 0.03), followed by early extrusion (P < 0.001). Late complications were detected in 74 ears - for example, plugged tubes (P = 0.77) and recurrence of effusion (P = 0.01).
Conclusion
TT insertion is a temporary procedure performed until the Eustachian tube function returns to its normal function; however, this procedure has many problems during and after insertion. Difficulties of insertion and late side effects are common problems that can be anticipated in nearly one-fifth of the cases. Therefore, ORL surgeons must be aware of the type of difficulty and its management before performing the surgery.

Keywords: adverse effects, grommet insertion, otitis media with effusion, T-tube insertion, tympanostomy tube insertion


How to cite this article:
Ragab A, Mohammed AA, Abdel-Fattah AA, Afifi AM. Prevalence of complications associated with tympanostomy tube insertion. Menoufia Med J 2015;28:918-22

How to cite this URL:
Ragab A, Mohammed AA, Abdel-Fattah AA, Afifi AM. Prevalence of complications associated with tympanostomy tube insertion. Menoufia Med J [serial online] 2015 [cited 2020 Feb 28];28:918-22. Available from: http://www.mmj.eg.net/text.asp?2015/28/4/918/173673


  Introduction Top


Otitis media with effusion (OME) is one of the most common diseases in the pediatric population [1] . OME is characterized by the presence of fluid within the middle ear (ME) cavity; in the absence of the symptoms and signs that would indicate an acute infection or tympanic membrane (TM) perforation [2] . Children younger than 7 years are at increased risk for otitis media because of multifactorial pathogenesis such as viral or bacterial infections,  Eustachian tube More Details dysfunction (ETD), immunologic conditions, and allergy [1] . Long-standing bilateral OME may cause long-lasting cognitive and language problem in the affected child [3],[4] .

According to a systemic review published in 2014, the management of OME with either nonsurgical methods such as watchful waiting for 3 months or local and systemic steroid, alone or in combination with an antibiotic, produce faster short-term resolution of OME [5] , but there is no evidence of long-term benefit [6] . Surgical treatment is the best modality of management [7] once OME has persisted in both ears for 3 months or longer and the chance of spontaneous resolution is low [6],[8] .

Tympanostomy tube (TT) insertion is the most common ambulatory surgery performed in the US with an annual insertion of 670 000 TTs [9] .

There are difficulties and complications that may follow this operation. Armstrong [10] said the following at the beginning of the TT era: 'An ideal TT should not clog up or drop out prematurely, should be inserted and removed easily and should have a low rate of complications'.

Difficulties of the surgery of TT insertion are related to general anesthesia and the effect of the TT on the TM and the ME [11] . After TT insertion and sufficient ventilation of the ME, the surgical procedure can lead to squeal such as purulent otorrhea, residual perforation of the TM, TM atrophy, myringosclerosis, and relapse of effusion [12] .

Most parents are willing to accept such minor risks in return for improvements in their children's hearing and reduction in ear infections [13] . In the majority of cases, the complications resolve with conservative management; however, sometimes we need to remove tube manually in cases of persistent infection, which did not respond to treatment. We may need surgical intervention in some cases, such as myringoplasty in residual perforation [14] .

In view of the high incidence of this disease in children and the fact that TT is one of its major treatments, we decided to conduct this observational study on patients who underwent TT insertion to evaluate difficulties during surgery, complication after surgery, and management of these problems.


  Patients and methods Top


The present study included 220 patients with OME who underwent TT insertion after failure of medical treatment. They were randomly selected from the outpatient clinic of ORL Department, Menoufia University Hospital and Health Insurance Hospital in Nasr City, during the period from 1 March 2013 until 1 March 2014. Consent was obtained from patients or their parents before surgical intervention, and the study was approved by the ethical committee of Menoufia University Hospital.

Personal history was taken as regards age, sex, residence, special habits of the patients or their relatives and analysis of the complaint of diminution of hearing, other nasal or ENT problems, and other ENT operations performed. This was followed by examination of the ear, nose, oropharynx, and hearing evaluation, including tympanometry and pure-tone audiometry.

Surgery of TT insertion was performed under general anesthesia. Evaluation of the prevalence and difficulties during surgery of TT insertion, complications after surgery, and modalities for management was carried out. Complications that occurred at the first month postoperatively were considered as early complications. Other complications were considered as late complications.

The results were analyzed using descriptive statistical methods and SPSS (17.0; SPSS Inc., Chicago, Illinois, USA). We used mean, Z-test, and the χ2 -test. A P value was significant if it was less than 0.05 and highly significant if it was less than 0.001.


  Results Top


This study included 220 patients (378 ears) with persistent OME despite medical treatment for 3 months. All patients underwent TT insertion. The ages of patients ranged from 3 to 70 years, with a mean age of 23.1 ± 23.806 years. Most patients were less than 12 years and comprised 126 (57.3%) patients. There were 144 (65.5%) male patients and 76 (34.5%) female patients.

Unilateral TT insertion was performed in 62 (28.2%) patients, and bilateral TT insertion was performed in 158 (71.8%) patients. There were 387 operated ears with TT insertion, 286 (75.7%) ears with grommet tube and 92 (24.3%) ears with T tube.

Only 102 (46%) patients underwent TT insertion with no other operation performed; 62 (28%) patients underwent adenoidectomy with TT insertion, 52 (24%) patients underwent adenotonsillectomy, and four (2%) patients underwent radical mastoidectomy at the other site.

In 10 patients, we did pathological assessment after adenoidectomy in unilateral OME. In one patient the biopsy revealed nasopharyngeal carcinoma.

There were 198 problems detected; 82 difficulties were observed during insertion of TT. Early problems were observed in 42 (within the first month) and 74 problems were observed late after tube insertion (after 1 month of TT insertion and until 6 months follow-up; P < 0.001) ([Table 1]).
Table 1 Difficulties, early complications, and late complications of tympanostomy tube insertion


Click here to view


The most common problem observed during insertion of TTs was the thick mucoid discharge in 22 (5.8%) ears (P = 0.10). Some problems were not related to the type of TT, which were observed significantly - for example, narrow canals in 16 (4.2%) ears (P = 0.005), anterior hump in 14 (3.7%) ears (P = 0.002), small ME cavity in four (1%) ears (P < 0.001), very thin TM in four (1%) ears (P < 0.001), large myringosclerotic patch in two (0.5%) ears (P < 0.001), and difficult handling in two (0.5%) ears (P < 0.001) ([Table 2]). The other problems were related to the type of TT, such as bleeding in 12 (3.2%) ears (P < 0.001), difficult insertion in four (1%) ears (P = 0.03), and medially displaced tube in two (0.5%) ears (P = 0.31) ([Table 3]).
Table 2 Difficulties during tympanostomy tube insertion that are not related to the type of tympanostomy tubes


Click here to view
Table 3 Difficulties during tympanostomy tube insertion that are related to the type of tympanostomy tubes


Click here to view


The most common problems early after insertion of TTs were otorrhea in 20 (5.3%) ears (P = 0.03), early extrusion of tubes in eight (2.1%) ears (P < 0.001), plugged tube in eight (2.1%) ears (P < 0.001), otitis externa in four (1%) ears (P = 0.03), and falling of tube in ME in two (0.5%) ears (P = 0.32). ([Table 4]).
Table 4 Prevalence of ears with early complications after tympanostomy tube insertion and relation to the tympanostomy tube type used


Click here to view


In the present study there were 74 late complications in 68 ears after 1 month of tube insertion and for 6-month follow-up. The most common late complications were plugged tubes in 24 (6.3%) ears (P = 0.77), recurrence of the pathology (OME) in 16 (4.2%) ears (P = 0.01), residual perforation in 12 (3.2%) ears (P = 0.22), late otorrhea in 10 (2.6%) ears (P = 0.02), myringosclerosis in six (1.6%) ears (P = 0.56), granulation tissue in four (1%) ears (P = 1.0), and focal atrophy in two (0.5%) ears (P = 0.32) ([Table 5]).
Table 5 Prevalence of late complications after tympanostomy tube insertion and relation to the tympanostomy tube type used


Click here to view



  Discussion Top


Difficulties during insertion of TTs were observed in 21.7% of operated ears. In the literature, there are no complete data on the difficulties faced by the pediatric otorhinolaryngologic surgeons concerning TT insertion.

The most common difficulties during insertion of TTs were mucoid discharge (which is sticky) (5.8%), but Allen et al. [15] recorded mucoid discharge in 36% of operated ears. Using saline irrigation facilitates removal of thick mucoid discharge in all cases (100%), and Bluestone [16] used instillation of saline. There were 16 (4.2%) ears with narrow canal. We used small cone in 12 (75%) ears as mentioned by Bluestone [16] . The authors used 2.7 mm 0° endoscope for insertion of tubes in four (25%) ears [17] . In 14 (3.7%) ears, there were anterior humps. Hirsch [18] inserted the tube in posteroinferior quadrant due to prominent convexity of the anterior bony canal wall. Bleeding occurred in 12 (3.2%) ears, but Allen et al. [15] recorded bleeding in 28% of ears during insertion of tubes. The most common site of bleeding was the anterior meatal wall, mainly due to the anterior hump and narrow canal. We used adrenaline on cotton tip, as described in the study by Hirsch [18] . The ME cavity was very shallow in four (1%) ears. In two ears we widened the incision with forceps. There were four (1%) ears with very thin TM. The needle was used for insertion as described by Bluestone [16] . There were 0.5% of cases with very large myringosclerotic patch; we tried to put the tube far away from the patch fearing necrosis. Difficult insertion due to obesity occurred in 0.5% of cases. They were obese female patients and we could not insert the tube in the right ear with 200 mm lens of microscope, so we used 300 mm lens. This point has not been raised in previous studies. Medially displaced tube during operation occurred in two (0.5%) ears due to large myringotomy incision, so we removed the tubes (which was grommet tube) and put a piece of gel foam as described in the study of Hirsch [18] .

Early complications after TT insertion occurred in 11.6% of operated ears during the 1-month follow-up period.

Transient otorrhea is the most common early complication, which occurred in 20 (5.3%) ears, whereas Erdoglija et al. [19] reported transient otorrhea in 12.5% of the ears operated. The authors used ototopical ciprofloxacin/dexamethasone drops (Dexaflox) in 40% of ears, systemic antibiotic and ototopical drops in 10% of ears, systemic antibiotic and ototopical drops in 20% of ears due to otitis externa, and in 30% of ears otorrhea was not treated and tubes were extruded. In a meta-analysis carried out by Kay et al. [11] , the number of tubes requiring extraction due to otorrhea was 4%, whereas in the present study only 1.6% of tubes required extraction. Allen et al. [15] reported early extrusion of TTs in 1.6% of ears, and Erdoglija et al. [19] reported in 3.9% of ears, whereas in the present study, early extrusion occurred in 2.1% of ears; all of them occurred after the use of grommet-type tube. Early extrusion in 1.6% of ears was due to otorrhea, which did not respond to medical treatment, and in 0.5% of ears the cause of early extrusion was not known. Erdoglija et al. [19] suggested that one of the reasons for premature extrusion of TT was iatrogenic, such as too big myringotomy, which can be avoided by careful otomicroscopy work. In four (1%) ears there was recurrence of OME and the patients were prepared for another operation using T-type tube. Indeed, Epstein et al. [20] recorded a rate of blockage of tube by blood of less than 2% in their study of 430 children, whereas Kay et al. [11] in their meta-analysis reported a blockage rate of 6.9%. However, in the present study early plugged tube rate was 2.1%: half of them plugged with blood clot and the other half plugged with wax. Blood was removed by irrigation with saline/H 2 O 2 and suction, whereas wax removed by suction after use of wax softener eardrops. Otitis externa occurred in four (1%) ears due to excessive otorrhea, which responded to repeated packing with Ab+steroid cream and then with ototopical antibiotic steroids (Ab+) steroid drops+systemic. Erdoglija et al. [19] reported falling of TTs in the ME cavity with a rate of 0.5%, which is the same as that reported in the present study.

Late complications after TT insertion occurred in 19% of operated ears during the 6-months follow-up period.

In the present study, delayed plugged tube was the most common problem (6.3%); in 3.2% of ears we used only suction to remove it, and in 2.1% of ears we gave wax softener first and performed suction after 1 week. In four (1%) ears we could not remove wax and we extracted the tubes. Erdoglija et al. [19] reported TT obstruction in 9.5% of ears, which was treated with local 3% hydrogen peroxide eardrops. In a British report on patients with bilateral OME, 5-28% of the ears still showed signs of OME 10 years after the first myringotomy or tube insertion [21] . In the present study, recurrence of OME occurred in 16 (4.2%) ears. In 10 (2.6%) ears we inserted T-type tube, and in four (1%) ears grommet tubes were inserted; the other two (0.5%) ears were improved with medical treatment. Persistent late perforation is one of the most serious complications following TT insertion, because it requires additional intervention. Perforation of the TM was observed in 1% of patients in a study conducted by Curley [22] , in 13-18% of patients by Matt et al. [23] , and in 3.1% of patients by McLelland [24] . In the present study, residual perforation occurred in 12 (3.2%) ears, in eight (2.1%) ears after T-tube insertion and in four (1.1%) ears after grommet tube insertion, and we prepared patients for myringoplasty. Saki et al. [25] reported delayed otorrhea in 8.2% of operated ears, and Kay et al. [11] reported delayed otorrhea in 26% of cases. In the present study, delayed otorrhea was reported in 10 (2.6%) ears: in eight (2.1%) ears after T-type tube insertion, in two (0.5%) ears only after grommet tube insertion. In four (1%) ears it occurred after acute attack of otitis media, which was resolved with medical treatment, in two (0.5%) ears it was due to granulation tissue, which did not resolve until we removed the tube, and in four (1%) ears it resolved with ototopical drops with unknown cause. Myringosclerosis was reported to be 52% by Pichichero et al. [26] and 32% by Kay et al. [11] , whereas it was only 1.6% in the present study. In all ears no effect on hearing was detected. Kay et al. [11] reported a 5% incidence of granulation tissue around TT in their meta-analysis, and Saki et al. [25] reported an incidence of 3.4%. However, Erdoglija et al. [19] reported granulation tissue in 1.1% of cases, which is nearly similar to that reported in the present study in which granulation tissue occurred in four (1%) ears. Two (0.5%) ears were managed with local Ab/steroid drops, and the other two (0.5%) ears did not respond to local drops and otorrhea was persistent and we removed the tubes. Johnston et al. [27] reported atrophy of the TM in 74.7% of ears with tubes. Maw and Bawden [22] and Yaman et al. [1] found TM atrophy in 22 and 23.5% of ears with tubes, respectively. In the present study, we found atrophy in 0.5% of ears that had been operated on, with no effect on hearing.


  Conclusion Top


TT insertion is a temporary procedure performed until the Eustachian tube function returns to its normal function; however, this procedure has many problems during and after insertion. Difficulties of insertion and late side effects are common problems that can be anticipated in nearly one-fifth of the cases. Therefore, ORL surgeons must be aware of the type of difficulty and its management before performing the surgery.


  Acknowledgements Top


Conflicts of interest

None declared.

 
  References Top

1.
Yaman H, Yilmaz S, Alkan N, Subasi B, Guclu E, Ozturk O. Shepard grommet tympanostomy tube complications in children with chronic otitis media with effusion. Eur Arch Otorhinolaryngol 2010; 267 :1221-1224.  Back to cited text no. 1
    
2.
Bluestone CD, Klein JO. Otitis media in infants and children. 3rd ed. Philadelphia: W.B. Saunders; 2001.  Back to cited text no. 2
    
3.
Roark R, Petrofski J, Berson E, Berman S. Practice variations among pediatricians and family physicians in the management of otitis media. Arch Pediatr Adolesc Med 1995; 149 :839-844.  Back to cited text no. 3
    
4.
Bluestone CD, Swarts JD. Human evolutionary history: consequences for the pathogenesis of otitis media. Otolaryngol Head Neck Surg 2010; 143 :739-744.  Back to cited text no. 4
    
5.
http://www.ncbi.nlm.nih.gov/pubmed/?term=Mikals%20SJ%5BAuthor%5D&cauthor=true&cauthor_uid=24287958, Mikals SJ, http://www.ncbi.nlm.nih.gov/pubmed/?term=Brigger%20MT%5BAuthor%5D&cauthor=true&cauthor_uid=24287958, Brigger MT. Adenoidectomy as an adjuvant to primary tympanostomy tube placement: a systematic review and meta-analysis. http://www.ncbi.nlm.nih.gov/pubmed/24287958. JAMA otolaryngology-head & neck surgery. JAMA Otolaryngol Head Neck Surg. 2014 Feb;140(2):95-101. doi: 10.1001/jamaoto.2013.5842.  Back to cited text no. 5
    
6.
Zulkiflee S, Asma A, Philip R, Siti Sabzah MH, Sobani D, Nik Khairulddin NY, et al. A systematic review of management of otitis media with effusion in children. Br J Med Med Res 2014; 4 :2119-2128.  Back to cited text no. 6
    
7.
http://www.ncbi.nlm.nih.gov/pubmed/?term=Schilder%20AG%5BAuthor%5D&cauthor=true&cauthor_uid=24259344. Schilder AG, http://www.ncbi.nlm.nih.gov/pubmed/?term=Burton%20MJ%5BAuthor%5D&cauthor=true&cauthor_uid=24259344. Burton MJ, http://www.ncbi.nlm.nih.gov/pubmed/?term=Shin%20JJ%5BAuthor%5D&cauthor=true&cauthor_uid=24259344. Shin JJ, http://www.ncbi.nlm.nih.gov/pubmed/?term=Rosenfeld%20RM%5BAuthor%5D&cauthor=true&cauthor_uid=24259344. Rosenfeld RM. Extracts from the Cochrane Library: interventions for the prevention of postoperative ear discharge after insertion of ventilation tubes (grommets) in children. http://www.ncbi.nlm.nih.gov/pubmed/24259344. Otolaryngology-head and neck surgery: official journal of American Academy of Otolaryngology-Head and Neck Surgery. Otolaryngol Head Neck Surg. 2013 Dec;149(6):813-6. doi: 10.1177/0194599813512081.  Back to cited text no. 7
    
8.
American Academy of Otolaryngology-Head and Neck Surgery. Clinical practice guideline: tympanostomy tubes in children. Available at: http://oto.sagepub.com/content/149/1_suppl/S1. Accessed 1 July 2013.  Back to cited text no. 8
    
9.
Cullen KA, Hall MJ, Golosinskiy A. Ambulatory surgery in the United States, 2006. Natl Health Stat Report 2009; 11 :1-25.  Back to cited text no. 9
    
10.
Armstrong BW. What your colleagues think of tympanostomy tubes. Laryngoscope 1968; 78 :1308-1313.  Back to cited text no. 10
[PUBMED]    
11.
Kay DJ, Nelson M, Rosenfeld RM. Meta-analysis of tympanostomy tube sequelae. Otolaryngol Head Neck Surg 2001; 124 :374-380.  Back to cited text no. 11
    
12.
Kenna MA. Diagnosis and management of acute otitis media and otitis media with effusion. In: Wetmore RF, Muntz HR, McGill TJ, Postic WP, Healy GB, Lusk RP, editors. Pediatric otolaryngology: Principles and practice pathways. New York: Thieme; 2000. pp. 272-7.  Back to cited text no. 12
    
13.
Inglis AF, Gates GA. Acute otitis media and otitis media with effusion. In: Cummings CW, Harker LA, Haughey BH, Richardson MA, Robbins KT, et al., editors. Flint PW. 4th ed. Philadelphia: Mosby Elsevier; 2005. pp. 44-56.  Back to cited text no. 13
    
14.
Umapathy N, Dekker PJ. Myringoplasty: is it worth performing in children?. Arch Otolaryngol Head Neck Surg 2003; 129 :1053-1055.  Back to cited text no. 14
    
15.
Allen J, Morton RP, Ahmad Z. Early post-operative morbidity after tympanostomy tube insertion. J Laryngol Otol 2005; 119 :699-703.  Back to cited text no. 15
    
16.
Bluestone CD. Tympanostomy tubes and related procedures chapter 1]. In: Bluestone CD, Rosenfeld RM, editors. The surgical atlas of pediatric otolaryngology. Hamilton, ON: BC Decker Inc.; 2002. 1-20.  Back to cited text no. 16
    
17.
El-Haussieny S, El-Rashedy A, Ragab A, El-Demerdash A. Role of otoendoscopy in diagnosis and treatment of otitis media with effusion MSc thesis]. Menoufia: Menoufia University School of Medicine; 2007.  Back to cited text no. 17
    
18.
Hirsch BE. Otitis media, myringotomy, and tympanostomy tubes. In: Myers EN. Operative otolaryngology. 2nd ed. Philadelphia: WB Saunders; 2008. 1125-1132.  Back to cited text no. 18
    
19.
Erdoglija M, Jelena Sotirovi J, Baleti N. Early postoperative complications in children with secretory otitis media after tympanostomy tube insertion in the Military Medical Academy during 2000-2009. Vojnosanit Pregl 2012; 69 :409-413.  Back to cited text no. 19
    
20.
Epstein JS, Beane J, Hubbell R. Prevention of early otorrhea in ventilation tubes. Otolaryngol Head Neck Surg 1992; 107 (Pt 1):758-762.  Back to cited text no. 20
    
21.
Maw AR, Bawden R. Tympanic membrane atrophy, scarring, atelectasis and attic retraction in persistent, untreated otitis media with effusion and following ventilation tube insertion. Int J Pediatr Otorhinolaryngol 1994; 30 :189-204.  Back to cited text no. 21
    
22.
Curley JW. Grommet insertion: some basic questions answered. Clin Otolaryngol Allied Sci 1986; 11 :1-4.  Back to cited text no. 22
[PUBMED]    
23.
Matt BH, Miller RP, Meyers RM, Campbell JM, Cotton RT. Incidence of perforation with Goode T-tube. Int J Pediatr Otorhinolaryngol 1991; 21 :1-6.  Back to cited text no. 23
    
24.
McLelland CA. Incidence of complications from use of tympanostomy tubes. Arch Otolaryngol 1980; 106 :97-99.  Back to cited text no. 24
[PUBMED]    
25.
Saki N, Nikakhlagh S, Salehe F, Darabifard A. Incidence of complications developed after the insertion of ventilation tube in children under 6 years old in 2008-2009. Iran J Otorhinolaryngol 2012; 24 :15-18.  Back to cited text no. 25
    
26.
Pichichero ME, Berghash LR, Hengerer AS. Anatomic and audiologic sequelae after tympanostomy tube insertion or prolonged antibiotic therapy for otitis media. Pediatr Infect Dis J 1989; 8 :780-787.  Back to cited text no. 26
    
27.
Johnston LC, Feldman HM, Paradise JL, Bernard BS, Colborn DK, Casselbrant ML, Janosky JE. Tympanic membrane abnormalities and hearing levels at the ages of 5 and 6 years in relation to persistent otitis media and tympanostomy tube insertion in the first 3 years of life: a prospective study incorporating a randomized clinical trial. Pediatrics 2004; 114:58-67.  Back to cited text no. 27
    



 
 
    Tables

  [Table 1], [Table 2], [Table 3], [Table 4], [Table 5]



 

Top
 
 
  Search
 
Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
Access Statistics
Email Alert *
Add to My List *
* Registration required (free)

 
  In this article
Abstract
Introduction
Patients and methods
Results
Discussion
Conclusion
Acknowledgements
References
Article Tables

 Article Access Statistics
    Viewed1852    
    Printed7    
    Emailed0    
    PDF Downloaded127    
    Comments [Add]    

Recommend this journal


[TAG2]
[TAG3]
[TAG4]