1. EPIGLOTTIC ENTRAPMENT: CLINICAL OUTCOMES AND RACE DAY PERFORMANCE Daniel Shaw B.V.SC M.R.C.V.S Cert ap(E-SO) Singapore Turf Club

2. NEW ZEALAND Home of lord of the rings

3. EPIGLOTTIC ENTRAPMENT- CLINICAL EVIDENCE IN PRACTICE Sub epiglottic tissue becomes entrapped over the epiglottis First described 40 years ago- Boles (1978) JAVMA Forces of Evil Without symptoms, associated with poor performance

4. PERFORMANCE Shortened epiglottic length? Tulleners (1990) Predisposed to dorsal dislocation of soft palate Fulton (2012)

5. LARANGOTOMY CURVED BIOUSTRY HOOK Honnas et al (1988)- Epiglottic entrapment a transnasal surgical approach to divide the aryepiglottic fold in the axially in the standing horse- Vet Surgery ENDOSCOPE GUIDED INTRANASAL IN STANDING HORSE

6. COMPLICATIONS- EVOLUTION TO NEW METHODS LACERATION OF SOFT PALATE Holcombe et al (1994) Surgical repair of iatrogenic soft palate defects in 2 horses JAVMA ANAETHESIA INTRA ORAL ROSS et al (1993) Trans oral axial division under endoscopic guidance JAVMA Minimal complications, superior race performance to laryngotomy. Lumsden(1994) Surgical treatment for epiglottic entrapment in horses 51 cases JAVMA

7. RISK OF GENERAL ANESTHESIA Laser in standing horse Tulleners(1990) JAVMA Safety hook Lacourt (2009) How to use a safety hook to treat EE in the horse AAEP Intra oral in standing horse Perkins et al(2007) 15 horse, standing, intra oral, endoscope guided Vet Surgery

8. TO OPERATE OR IGNORE? Operate in most cases, variety of techniques Don’t recommend surgery REF Brown et al EVJ (2005) Post racing survey 744 tb horses in Victoria Detected EE in 7 horses Associated with superior athletic performance “Surgical correction may not be necessary”

9. VET IS AN IDIOT!

10. DAIRY VS EQUINE SURGERY MATAMATA NZ HOBBITON

11. EVIDENCE BASED MEDICINE STRONG EVIDENCEWEAK EVIDENCE CASE SERIES CASE STUDY OPINION EXPERIENCE MEMORY IINTERVENTION STUDIES Randomized prospective controlled blind CONTROLLED OBSERVATION STUDIES Cohort Study Case Control Study Cross Sectional Study

12. BEARD AND WATSON VET CLIN EQUINE (2007)REVIEW –EVIDENCE BASED EQUINE UPPER RESPIRATORY SURGERY Good EBM for EE is lacking-variety of reasons Can review the literature-critical appraisal Can perform clinical audit Design a good observational study- prospective matched controls

13. MATERIAL AND METHODS 2008-2012 Epiglottic Entrapments and Singapore Turf Club. Pulled from the records of Rx works Able to determine race record post surgery web site

14. MATERIALS AND METHODS Able to find a match control from the next MRA number up that was racing at the time of surgery. Race records from the website Able to search Rx works for history of horse post op for any complications. Able to identify a group of horses that raced with the epiglottis entrapment present, and compare race records with same horses post surgery and matched controls. (Better than pre and post surgery, and survey studies)

15. METHOD OF SURGERY- MACAU RUSSEL AND WAINSCOT(2007) THE VET RECORD Injectable GA Simple equipment Knock down room only Horse on right side, person on left side

17. KEEP ENTRAPPING UNTIL NO LONGER SITS ON EPIGLOTTIS HAND SIZE, SHARP TEETH. CUT IN TO THE TONGUE..

18. STATISTICS……..”MAGIC” Big Mistake. Strongly encourage to learn and do Excellent on line masters refreshers courses.

19. CASE SERIES 32 CASES OVER 5 YEARS INCIDENCE OF 0.6% PREVALENCE 7 cases 750 horses in Victoria (0.9 %) “NOT uncommon in equine racetrack practice”

20. CASE SERIES Minor Complication “Normal Finding” ACVS 2014 Sub epiglottic Tissue Thickened adhered tissue Chronic cases Improved with time, conservative treatment Raced normally Re entrapped, 2 nd surgery More common with Laryngotomy techniques Raced normally between and after surgeries. Acute or months-years

21. COMPLICATION RATE –CASE SERIES 1/32 (3%) – 2 nd surgery 2/32 –(6%) Incomplete clearance 3/32- (9%) “Excess granulation tissue” 18 % Total Reported rate 10% ACVS 2013 regardless of method

22. CASE SERIES Using this method is a safe, effective, comparative complication rates with other methods. Problems with case series…bias, uncontrolled, not blind, surgeon evaluating own work. Level of evidence –low

23. COHORT STUDY Matched controls Compared race records post surgery The exposure factor surgery to correct an epiglottic entrapment, outcome race day performance Matched cohort of horses without epiglottic entrapment, similar age, race experience, time in Singapore

24. COHORT STUDY Total RacesWINSPLACINGS HORSES POST SURGERY N=32 4502689 MATCHED CONTROLS N=32 4503279

25. COHORT STUDY winnersplacerslosers Post surgery 32 14126 Matched controls 32 1589

26. COHORT STUDY

28. RESULTS STATISTICS CHI SQUARED TESTS ON TOTAL RUNS, WINS,PLACINGS CHI SQUARED TESTS ON WINNERS, PLACERS, LOSERS. WILCOXON SIGNED RANK TEST FOR NUMBER STARTS,WINS,PLACINGS POST SURGERY DATE (MATCHED CONTROLS NON NORMAL DISTRIBUTION)

29. COHORT STUDY- CONCLUSIONS UNABLE TO REJECT THE NULL HYPOTHESIS (p>0.05) “NO SIGNIFICANT DIFFERENCE BETWEEN THE CASES AND MATCHED CONTROLS” (INCORRECT STATEMENT…. Can either Reject the null hypotheses. Find a significant difference (p<0.05), or not reject. ……Cannot say the 2 groups are “the same” Type 2 error versus type 1 error)

30. 2 ND COHORT STUDY- HORSES RACED WITH EPIGLOTTIC ENTRAPMENT PRESENT. RX works, diagnosed pre race Stewards report-Post race examinations 19 Horses raced 20 times with an epiglottic entrapment present. Had surgery and raced 289 times post surgery

31. 2 ND COHORT STUDY N=19First 3 finish (%) Last 3 finish (%) Horses with EE565 Horses post EE correction2934 Matched controls2438

32. FINISHING POSITION- EE PRESENT, CORRECTED, MATCHED CONTROLS

33. 2 ND COHORT STUDY –RESULTS There is a significantly lower chance of the horses running in the first 3 (p=0.05) There is a significantly great chance of the horses running in last 3 (p=0.03)

34. 2 ND COHORT STUDY –RESULTS Individually, some horses can perform well with epiglottic entrapment(1 winner) Overall, horses will run first 3 less often and last 3 more often, if running with EE Evidence moderate Selection bias, numbers.

35. CONCLUSIONS………THE END! Attempted to apply EBM to a clinical problem in practice Intra oral EE axial cutting using curved hook under GA is a safe and effective method of correcting EE Post surgery, horses can be expected to go on and have normal race careers. Some horses can race well with EE present, but overall performance will be significantly improved by surgical correction.