The Evolution of the Epidural Needles

1. The Evolution of the Epidural Needles Joseph Eldor, MD

2. All Epidural Needles Are Not Created Equal

3. Spectral analysis of epidural needles

4. Epidural needles are composed of Iron (69%), Chromium (18%), Nickel (9%), Manganese (1.5%), Silicone(0.5%) and Molybdenum (between 0.2% to 2.7%). Different needles – different compositions…

5. Hardness of the needles and stilletes

6. Epidural needles differ also by the hardness of the needles and stilletes.

7. For example, BD 18G Tuohy needle is 383 VPN Vs. BD 18G Crawford needle’s 507 VPN. Again, different needles – different composition…

8. Dimensions and clearance of needles

9. Epidural needles differ also by their dimensions. For example, the inner diameter of the BD 18G Tuohy needle is 1.053 mm while the Portex 18G Tuohy needle’s is 1.220 mm…

10. However, Epidural anesthesia is an integral part of today’s practice of Anesthesiology.

11. A change in needle design was significant among the improvements.

12. Epidural needles are often very broadly referred as “Tuohy needles” even though their needle tip configuration is much closer to that of a Hustead needle design.

13. In 1901 the French Radiologist Jean Anthanase Sicard described injecting dilute solutions of cocaine through the sacral hiatus to treat patients suffering from severe intractable pain or lumbago.

14. Dr. JEAN ANTHANASE SICARD (1872-1929)

15. Fernand Cathelin reported similar work 3 weeks later than Sicard. He recognized that sacral injections of cocaine might also be used for surgery.

16. In 1921 a Spanish surgeon Fidel Pagés described a lumbar approach to epidural anesthesia.

17. In 1933 an Italian surgeon Archile Mario Dogliotti performed abdominal surgery with single shot lumbar epidural anesthesia.

18. Most medical historians date the regular use of epidural anesthesia from Dogliotti’s article: Dogliotti AM. A new method of block: segmental peridural spinal anesthesia. Am J Surg 1933;20: 107-18

19. However, a Romanian obstetrician ,Eugene Aburel, injected chinocaine through a silk ureteral catheter to block the lumboaortic plexus of laboring women two years before Dogliotti, in 1931.

20. In the USA, Hingson and Edwards devised a method for continuous caudal anesthesia and used it on 33 laboring patients in 1942.

21. Two years later, in 1944, Hingson and Southworth described a lumbar approach for continuous epidural anesthesia using a 15 gauge Barker spinal needle and a silk ureteral catheter “to but not into the peridural space”. They obtained satisfactory anesthesia in only 10 of 16 patients.

22. BARKER NEEDLE

23. Ralph L. Huber designed in 1946 a needle with a directional tip which allowed anesthesiologists to direct the catheter as it exited the needle tip (US patent 2 409 979. October 22, 1946).

24. Although Huber intended this needle for IV and tissue injections, Edward B. Tuohy recognized that the directional point might facilitate placement of spinal catheters.

25. Tuohy also added a stylet, thereby hoping to further decrease the risk of skin plugging.

26. The Cuban anesthesiologist, Manuel Martinez Curbelo, described in 1949 the use of a 16 gauge Huber (Tuohy) needle with a 3.5 F silk ureteral catheter for continuous segmental lumbar peridural anesthesia.

27. Charles E. Flowers, an obstetrician at Johns Hopkins University, altered the Huber (Tuohy) needle by blunting the bevel and designing the stylet to protrude past the needle tip in 1949.

28. However, Robert Hustead, another Hopkins colleague, called the Tuohy-Flowers modification a “technical nightmare”…

30. However, Flower’s idea of a blunt tip did have appeal, and it became part of further enhancements by Crawford, Weiss, Sprotte and even Hustead himself.

31. Robert Hustead made his own modifications to the Tuohy-Huber needle by hand by using a stone and a needle sharpener…

32. Hustead sanded off the sharp tip of the original Tuohy-Huber needle and changed the angle of the bevel. The result was a needle opening that did not exceed 2.7 mm in length, with an angle of the needle bevel of 12º-15º.

33. Robert F. Hustead (born: 1928)

34. Crawford described in 1951 the use of an epidural needle with a straight tip in 677 patients for thoracic surgery.The Crawford epidural needle was a Quincke type with an extremely short, and thus a very blunt, bevel. The bevel of his needle was very flat (60º if measured from the longitudinal axis of the needle).

35. Oral Bascom Crawford (born: 1921)

36. CRAWFORD EPIDURAL NEEDLE

37. Jess Weiss dulled the needle tip and added “wings” to make it easier to grasp the needle with both hands for placement.

38. Jess Bernard Weiss (born: 1917)

39. WEISS TUOHY NEEDLE

41. Jürgen Sprotte of Würzburg, Germany developed in 1979 a pencil point needle for spinal anesthesia, similar to one designed by Hart and Whitacre but with a noticeable difference in its tip geometry: the original Whitacre needle had a short, cylindrical-tip configuration, whereas Sprotte used the olive-shaped, rounded-tip geometry.

42. In 1987 Sprotte started to experiment to make his needle more suitable for epidural use. He added a special plastic wedge to the inside of the needle tip that would direct an epidural catheter toward the lateral needle hole.

43. Jürgen Sprotte (born: 1945)

44. Epidural Sprotte Spezial Needle

45. Other Epidural Needles

46. Cheng needle was described in 1957. It was the first epidural needle with centimeter markings to indicate depth (US patent no. 2 922 420).

48. Unfortunately, the Cheng needle was described as “cumbersome” to use and “extremely difficult to effect”.

49. There are also the Wagner needle (1957), the Crawley needle (1968), the Foldes needle (1973) and the Bell needle (1975) – all variants of the Huber design with a blunted tip of varying sharpness.

50. There is the Brace needle, a Crawford variant.