Spinal & 
Epidural Needles

Ballpen® (2000)

In 2000, an article was published describing a new needle for spinal anesthesia (pictured above). Launched by the French industry Rusch™, was baptized with the name Ballpen®. In fact, it is a design very similar to the Levy needle from 1957. The prominent and sharp stylet in the original needle was replaced by a tip with the same characteristics, but incorporated into the main structure of the artifact. Among the acclaimed advantages of this design highlights the fact that at the time of withdrawal of the mandrel, the entire drainage and administration orifice will be in the subarachnoid space. Thus, unlike the lateral orifice needles in which you can introduce partly the orifice in the desired compartment, in this model the incidence of failure must be, at least theoretically, lower.

The Evolution of Spinal and Epidural Needles
From the Origins to the Current
Below is a list of some of the most commonly used spinal and epidural needles, used throughout the history of anesthesiology. This list is not exhaustive and certainly cannot address all models currently in existence. We often observe disputes among various authors trying to get recognition for the introduction of certain technique or needle. This explains some differences between the information published in different sources. Some of these pioneers have not published their studies until others, after them, took the initiative and absorbed the credit for these discoveries. In addition, several researchers have made only minor changes in previously published materials or procedures, requesting the public recognition of it for them. The history of  the development of the spinal needles is made out of failures, complications and changes, sometimes subtle or even  significant, until we reached  the standard for the current used needles.
Corning (1885)

American neurologist who performed the first subarachnoid block by accidentally administering cocaine in this space of a dog causing paralysis of its rear end. Soon afterwards he began to use this technique in humans to treat various neurological disorders. Despite not having used the technique for surgical anesthesia, Corning saw this possibility and thus is considered the precursor of spinal anesthesia. His needle (drawing below), was described in the New York Journal of Medicine in 1901. It was made of a flexible material, with an introducer and a limiter to keep the equipment fixed whilst approaching to the subarachnoid space. The tip of the needle consisted of a short and sharp bevel, based on the hypodermic needle by Alexander Wood in 1853.

Bier (1898)

The next significant step in the development of neuraxial anesthesia techniques derives from the work of a German physician, Karl Von Augustus Bier. In 1898, he and his assistant performed the first spinal anesthesia using cocaine as a local anesthetic. The researchers were used as guinea pigs. Initially, the assistant performed a lumbar puncture in Bier, whom felt a great pain in the leg during the puncture. As it was difficult to connect the syringe to the needle, there was significant loss of part of the anesthetic solution and drainage of large quantities of liquor which led to a failure of the block obtained. Then, Bier conducted a successful block on his helper. Finally, he experienced and described for the first time a common complication that, over 113 years later, is still not adequately outlined: the post-dural puncture headache. Nevertheless, this author continued his investigations within the technique, publishing in 1899, six reports of surgery on the lower limbs with this anesthetic technique. He described his own needle (drawing below). Bier understood that the use of dilators and sheaths, required for the thinner needles used until then, made the blockade more difficult to perform. Thus, his advocated needle was thick (15 or 17 Gauge), equipped with a sharp tip and a long bevel.

Quincke (1891)

In 1891, Heinrich Irenaeus Quincke, German physician, published a paper describing the technique of lumbar puncture by beveled cutting needle to drainage of cerebrospinal fluid in patients with intracranial hypertension. This pattern of tip, described by Quincke, served as a reference for many researchers and developers (detail in the figure below). Nowadays, the needle for lumbar puncture with these characteristics are widely used and defined with his name.

Bainbridge (1900)

American physician who described and published a subarachnoid puncture needle that he used for spinal analgesia in children in 1900. He was one of the first researchers to worry about the question of contamination of the injected solutions, recommending an aseptic technique and a method of sterilization of the anesthetic solution. This method consisted of dissolving the cocaine in ether, subsequent crystallization, and then again dissolving this time in a boiled and filtered water. The needle was equipped with what he described to an end with a short adapter ring, for connecting the syringe, a sharp beveled tip and with a mandrel corresponding to the length of the needle.

Barker (1907)

Arthur Edward James Barker, an English physician, was one of the most responsible for popularizing the spinal anesthesia. Initially he started using a modified Bier needle. However, reported difficulties with the too elongated bevel. He said that the partial introduction of this bevel into subarachnoid space could lead to an adequate flow of cerebrospinal fluid, but with the deposition of the anesthetic solution in an improper place (this is still recognized as one of the most common causes of failed spinal anesthesia). Thus, described and published his own needle in 1907. It was a large-bore needle, 18 or 19 gauge, which was related to a very high incidence of post-dural puncture headache. It was equipped with a cutting bevel of medium size and a mandrel corresponding to its length. Previously only the needles were covered with a layer of nickel which led to a rapid wear and discoloration. Barker suggested that its composition should be entirely of "hard nickel", which consisted of a breakthrough in the manufacture of these artifacts. It is also worth mentioning that this Barker needle was used by Tuohy in 1944 when he introduced the techniques of continuous spinal anesthesia by placing a silk ureteral catheter (number 4) in the subarachnoid space of a patient.
Babcock (1914)

Since the end of the nineteenth century it was assumed that the cause of post-dural puncture headache was the loss of cerebrospinal fluid by the injury caused by dural puncture needle (Jean-Athanase Sicard, 1898 - image at left). Thus, in subsequent years was advised the use of smaller caliber
needles in order to minimize this complication.  Based on this principle, William Wayne Babcock described a needle in 1914 that was similar to the original Corning needle but had a smaller caliber (20 gauge). It was made of platinum or gold and also known as Quincke-Babcock needle. It was a widespread and successful model, becoming the standard spinal needle for comparison in future studies.
Labat (1921)

Gaston Labat was a French physician, settled in North America. In 1920’s he was one of the most responsible for popularizing the spinal anesthesia in both the U.S. and in Europe. In 1921, he designed a nickel "unbreakable" spinal  needle. It consisted of a medium-gauge needle with a mandrel inside equal to its length. The novelty was that it was equipped with a bevel shorter than those used so far. According to Labat, the shorter bevel serve to push the tissue away instead of cutting them, reducing injury following its dural penetration and minimizing the occurrence of post dural puncture headache. This idea of "push the tissue" was taken up later with the idealization of the conical tip needles, widely used today.

Hoyt (1922)

In 1922, Randall Hoyt published his theory that the large-bore needle commonly used  then, due to its rigidity, were responsible for the extensive dural lesion that was observed with its use. So he designed this set of needles for spinal puncture. The external, which served as an usher, was used to penetrate tissue and ligaments to the vicinity of the dura mater and resembled that described by Bier. Then a thinner needle was inserted inside to the dural approach. The use of this needle was associated with lower incidence of post-dural puncture headache back then. The description of Hoyt, despite using a variation of the classic model of Corning, was the basis for the development of the introducers for thin needles (27 or 29 Gauge) we observed in clinical use at this time.

Greene (1926 ou 1950)

In 1923, Herbert Merton Greene published his experimental laboratory studies on differences in the holes on the dura mater of different calibers and types of needle tip. He concluded that a smaller diameter hole resulted from the use of blunt needles compared to those with sharp edges. He continued his investigations, and in 1926 he published another study with a description of an "atraumatic needle with thin end" (picture below). Greene in his experiments showed that this form of needle tip was able to pass between the dural fibers rather than through them. Thus, at the time reported an incidence of post dural puncture headache less than 4%. At the end of life, the author became blind due to cataracts and an advanced keratitis (pictured above).

There are divergences in the available literature about the year of publication and responsibility for the design of this needle. Although the orginal Greene’s studies, some authors claim the recognition for the description of this type of needle to Barnett Greene that, in 1950, published the use of a 26 gauge needle through a 21-gauge introducer (picture above).

Pitkin (1927)

The next suggested modification in relation to the tip of the spinal needles was performed by American surgeon George Praha Pitkin in 1927. At the time, Pitkin was an ardent advocate of regional anesthesia as a safer alternative to general anesthesia. The needle that he had proposed had a short bevel with an angle of approximately 45 degrees from the longer stem to the shorter. This design, according to the author, aimed at two main functions: first, the relatively blunt tip of this design would provide a more accurate sense of the appropriate and correct subarachnoid positioning of the needle after dural puncture and, secondly, it aimed to open a tip "flap" in the dura mater which would naturally be obliterated with the CSF pressure, thus avoiding an excessive leakage of CSF. In the 1990s, this theory of "dural flap" would again be remembered by some authors that recommended the use of the paramedian access routine as a way to get this feature in the dural lesion.

Rovenstine (1944)

Andrew Emery Rovenstein, American physician, embraced the idea of the lateral hole in the needle. He published the description of his device in 1944. His major change consisted of obliterating the distal orifice of the needle (figure below). Thus, the flow of the anesthetic solution would necessarily be directed at the lateral hole creating, as he believed, a directional block more reliable and consistent. His theory was later disregarded by some authors who demonstrated that the initial flow direction of the anesthetic had little influence on the spread of subarachnoid block (Tarkilla et al, 1995).

Touhy (1945)

Edward Boyce Touhy was a prominent American anesthesiologist in the first half of last century. In 1944, he used a Barker’s needle for introducing a catheter into the subarachnoid space, thus avoiding the use of flexible needles previously recommended for this technique. Later, he made a significant change in the tip of this needle by adopting a standard described by the dentist Ralph L Huber (figure below).

Huber developed a tip for hypodermic needles with long, sharp, and fundamentally curved bevel (patent image below). His purpose was to reduce the pain during injections and minimize the risk of tissue fragments be allocated at the needle tip and subsequently inoculated into other deeper tissues. Tuohy figured that this curvature of the bevel needle tip would facilitate the introduction of catheters in the subarachnoid space, facilitating their cephalic or caudal direction.

In turn, it was not until 1949 that the Cuban anesthesiologist Manuel Martínez Curbelo published an article describing the use of Tuohy needle to epidural catheters location. He used silk urethral catheters, size 3.5 F, for the realization of segmental epidural anesthesia.

This pattern of needle, described by Tuohy (figure below), remains one of the most used worldwide to perform punctures and location of epidural catheters.

Cappe & Deutsch (1953)

Following the advent of conical tip needles for spinal anesthesia it was expected the appearance of similar artifacts to continuous spinal anesthesia. Although Tuohy had launched a few years before the concept of this technique with the use of malleable catheters rather than needles, the caliber of needles and catheters used by him led to the development of a high incidence of post-dural puncture headache. Thus, for continuous spinal anesthesia, following the profile of the use of malleable needles suggested for Lemmon and Hingson, Bernard Edward Cappe (illustration) and Enoch Deutsch described a malleable conical tip needle in 1953. It was a 20-gauge needle with a tip similar to Whitacre’s needle. The puncture was performed with the assistance of a 18 gauge introducer. The middle portion of the needle was looped and flexible to enable its attachment to the surface curvature at the patient's skin. It had a limiter adjustable to facilitate the set stabilization and immobilization (figure below).


Levy (1957)

In 1957, Walter Howard Levy proposed a modification of Sise’s original needle, from 1928. It was the second generation of needles with a protruded stylet. The device proposed by this author was 20 gauge with a narrow tip similar to the conical needles. It had also a sharp and cutting internal stylet that extended about 2 to 3 mm beyond the tip of the needle (figure below). Levy's needle was not widely used because it had some manufacturing problems: there was difficulty fixing the stylet beyond the tip of the needle during the puncture and the transition between the needle and the stylet was not as smooth as it should, and may cause more injury than expected in the dural fibers.

Sprotte (1987 e 1989)

After the 1960s emerged the diposable needles. Initially, the acceptance of it was not very significant in part because of its high initial cost, which was gradually reduced, and in part by the lack of an adequate quality control in the first years. However, these needles were responsible for a significant reduction in some of the more serious neurological deficits secondary to spinal anesthesia: those caused by residues of detergents and other cleaning solutions used in reusable needles.

The next big advent in the design of spinal needles was performed by the German physician Jürgen Sprotte in 1987. Nearly 37 years after the Whitacre proposed needle, this author suggested some modifications to it: an elongated tip in an attempt to promote a more gradual separation of the dural fibers, and in particular, a lateral orifice larger and oval (picture below). This larger orifice intended to facilitate the flow of cerebrospinal fluid and allow a better dispersion of the anesthetic solution administered. Some of the criticisms of these changes were based on the fact that the long end was more susceptible to trauma and subsequent breaks, and the side orifice too long could lead to an incomplete insertion into the subarachnoid space with loss of part of the anesthetic to the epidural space (figure below). In the early 1990's the orifice was slightly reduced in the models produced as a way to minimize these inconveniences.

Sprotte also gave his contribution to the epidural needles. In 1989, the researcher implemented the technique of continuous epidural by conical tip needles. He added a plastic edge to the inner distal face of its needle in order to direct the catheter through the lateral orifice. The needle is conventionally called the Special Sprotte Needle (figures below. Note in the first of it the dashed line corresponding to the distribution of this plastic piece).

Whitacre (1951)

As evidences grew, especially after Greene’s studies, that the dural fibers suffer fewer injuries and sections when the puncture was performed with non-sharp pointed needles, it appeared from the middle of last century a new category of spinal needle that would fundamentally change the use of these devices to modern times: conical pointed needles. Based on studies from Rovenstine and Kirschner, who designed needles with side holes, the North American anesthesiologists James R Hart and Rolland John Whitacre published in 1951, a study describing a conical tip and sided orifice spinal needle (figures below). Whitacre was a famous anesthesiologist at this time and became president of the American Society of Anesthesiologists (ASA). Unfortunately, he had an early death in 1956, at age 46.

The needle developed by these authors had a point described as "resembling a sharpened pencil" and a distal side orifice next to it. This description became popular and called these conical tip needles: “pencil point needles”.

One of the problems reported with the use of original Whitacre needle was the small size of the lateral orifice, making the flow of cerebrospinal fluid and administration of the anesthetic solution difficult. Despite this and after minor changes in its original design, the Whitacre needle is one of the most currently used for spinal and advocated, by many authors, for use in obstetric patients.

The Hart and Whitacre names are associated with the pioneering description of this conical tip needle. However, also in 1951 and only a few months before these authors, Sixten Haraldson published in Anesthesiology (figure below) an article describing a very similar needle design. This Haraldson needle did not get much recognition. Perhaps because he had only a local production of a small number of needles or, maybe, because it was a Swedish physician while the formers were famous Americans anesthesiologists at that time.


Brace (1955)

Even after the advent and popularization of the conical tip needles for spinal anesthesia, some authors continued to propose changes in those that had sharp bevels. At that time, with the advance of machinery for manufacturing and especially after the discovery and improvements in the composition of stainless steel, most authors were looking for thinner-gauge needles. In this context, Donald E Brace in 1955 developed a thinner gauge needle than those used previously (25 Gauge). He believed this was a more important factor than the type of point in the incidence of post dural puncture headache. Thus, his proposed needle had a medium size and sharp bevel (figure below). We now know that both the caliber and the type of the needle used represent preponderant factors in the incidence of post-dural puncture headache.

Lemmon (1940)

While most authors sought changes to the design of the needles to minimize the complications of the technique, other investigators began to look for alternatives and solutions that would enable the increased use of spinal anesthesia for surgical procedures. A major limitation was the time of surgical anesthesia provided. Thus, in 1940, William T Lemmon described and advocated a needle to be used in a technique of continuous spinal anesthesia. This needle was made of a malleable alloy of nickel/silver and used with an introducer. It had a short and sharp bevel and a lateral hole to facilitate a free flow of CSF (figure below). After the puncture, was folded and fixed on the skin surface and connected to a rubber tube through which local anesthetic was administered if needed. Finally, the patient had to be positioned on a surgical table mattress with a hole in which the needle protruding dorsal could be adequately accommodated.


Eldor (1990 e 1996)

Joseph Eldor, Israeli anesthesiologist, is a contemporary researcher and a strong promoter of regional anesthesia techniques. From the 1990s, this author described his needles for subarachnoid puncture and for use in combined spinal-epidural anesthesia.

In 1990, the author described his proposal needle for use in the combined technique. It consists of a variation of the Coombs needle. Unlike the previous one which has a double lumen throughout its length, the Eldor needle has only a lateral conduit (right or left) where the spinal needle should be inserted (figure below). Like the Coombs needle, allows the location of the catheter first before spinal anesthesia, allows the use of needles of any size and there is no need to use long needles. These are significant advantages of these special needles on the combined technique performance in relation to the "needle-through-needle" traditional method.

Later, in 1996, Eldor described a conical tip needle for use in spinal anesthesia. It is a needle with a tip similar to Whitacre but with a twist: instead of a single lateral orifice, it has two contra-lateral openings (figure below). Each of these holes in the Eldor needle is smaller than that described in the Sprotte needle, but the sum of its areas equals the size of it oval orifice. The idea behind this double hole is to allow a better dispersion of the anesthetic in the CSF, minimizing failures and neurological complications arising from the bad distribution of the anesthetic reported with small-bore needles. It also allows a faster flow of CSF when compared to the single orifice needle. (Text with the needles inventor collaboration)

Hingson (1943)

In 1943, the American physicians Robert Hingson and Waldo Edwards published their proposed modifications to Lemmon’s needle. Their needle also had a side hole near the distal end. However, the distal and proximal portions were rigid, with a central region looped and flexible. The connector had been modified from the original needle to facilitate attachment to the tube for administration of the anesthetic solution. However, positioning the patient in the supine position also demanded care (bed and table with holes) imperative for the use of Lemmon’s needle. After this, these authors practically abandoned their proposition, starting the use of malleable catheters for continuous epidural analgesia in parturients.

Flowers (1950)

One of the first proposed changes to the Tuohy needle was  suggested by the obstetrician Charles E Flowers. In 1950, he published an article on suggestions of improvement, according to his point of view: he reduced the opening of the bevel, made the same blunt and no more cutting and placed a mandrel that was a few millimeters larger than the needle, being protruded beyond the tip of it (pictures below). He justified the proposed bevel changes in order to reduce the chance of inadvertent puncture of the dura mater. The protuded mandrel in its turn, intended to facilitate the insertion of the needle through the skin. This model seems not to have worked as intended. The mandrel protruding tended to double up on the tip of the needle and making it difficult or even impossible to remove. However, the Flowers’s idea of a blunt tip seemed logical and feasible. Later, other authors followed his suggestion incorporating this data in the design of their needles as we will see (Weiss, Crawford, Hustead, Sprotte).


Tapered Needles (1960s)

In the 1960's it was already well established the concept that the caliber of the needles is a major factor in the genesis of post dural puncture headache. However, a minimum diameter was technically capable of be manufactured and used on occasion. The minimum size that they could get on the needles while maintaining stiffness and hence the security needed for a spinal tap was that of 25 Gauge. To circumvent this obstacle, it was developed needles with progressive decrease of their diameter from base to tip (20 Gauge in the base and 24 Gauge in the end). Two types were suggested: the first one had a decrease only in the distal end (distal tapper), while the second had a gradual reduction in the diameter from the base to the end (gradual tapper), as shown in the figures below.

These needles were not successful and did not gain large acceptance. First, it was reported a relatively high incidence of post dural puncture headache possibly because of its sharp beveled tip. Finally, the diameter at the base of these needles made it difficult to progress through the ligaments and tissues with the same hole made by  a smaller caliber tip. The force required for this progression could lead to breakage of needle’s distal end. The factors of failure of these needles are discussed in an article from 1994 by Sakai and Yoshikawa, published in the journal Anesthesia and Analgesia.

Hustead (1954)

Robert F. Hustead, American anesthesiologist, was one of those responsible for the popularity of epidural analgesia for labor and one of the founders of the Society for Obstetric Anesthesia and Perinatology (SOAP). Strong advocate of this technique, developed his own needle through changes in the Tuohy-Huber original needle. His prototype of this device, developed in the mid-1950s, was handcrafted using a "stone and a needle sharpening". Only in 1965 he found an industry interested in producing his needle on a commercial scale. Compared to the original Touhy needle, the device proposed by Hustead had a shorter, more angulated and less sharp bevel in order to minimize the chance of inadvertent puncture of the dura mater and possible injuries and sections of the catheter (Figure below).

Weiss (1961)

In 1961, Jess Bernard Weiss, American anesthesiologist, made changes in the Tuohy-Huber epidural needle. Adept of the hanging drop technique for identifying the epidural space, he made changes in the needle to facilitate this technique. Weiss, like Hustead had previously done, shortened the bevel becoming it less sharp. However, its major modification consisted of adding two side flaps next to the connector. These flaps were intended to facilitate the grip and its progression as he watched the hanging drop aspiration at the time of the epidural space approach (figure below). These flaps are still widely used by those who prefer the aspiration technique (hanging drop) to identify the epidural space.

Crawford (1951)

Oral Bascom Crawford, an American anesthesiologist, developed and published an epidural needle puncture in 1951. Unlike the concept of curved Huber tip needle used by Touhy, Crawford preferred a needle tip nearly straight. Thus, described a needle with a extremely short and, thereby, little sharp bevel. He used this needle mainly for thoracic punctures, with the identification of the epidural space through the hanging drop technique. In an article published in 1951, he described this technique in 677 thoracic surgeries, especially thoracoplasty, using thoracic epidural anesthesia.


Atraucan® (1993)

In 1993, the B Braun Medical™ developed a subarachnoid puncture needle with a cutting bevel. This model was baptized with the name Atraucan®. It was the return of the cutting tip needles. In the release article (pictured above), the authors claimed that the conical pointed needles had blunt tips, requiring a greater force for its progression. In addition, the side orifices far from the distal end could cause higher incidence of blocking failure than expected.

The Atraucan® has a characteristic tip with two rows of sharp bevels. Theoretically, the most sharp tip promotes the initial incision in the tissues and in the dura mater, and then the second part of the bevel enlarges the hole created instead of causing new tissue and dural fibers sections. One of the drawbacks of this design is the thinnest  and relatively fragile tip which may fracture during the puncture.


Kirschner (1932)

The studies and the development of needles continued in subsequent years with the emergence of those with side holes near its distal end. This pattern has become one of the theoretical bases for the appearance of modern conical tip needles. There are controversies about the creator of this standard and this drawing. Some sources claim to Barker’s (creator of the famous needle in 1907) this idea. However, a publication of the author himself in 1912 contradicts this information (figure below).

Indeed, it seems to have been the German physician Kirschner the first to publish the use of needles with lateral orifice and directional flow in 1932. He claimed that this lateral orifice would permit a unilateral block, cephalic or caudal according to the positioning of the needle during puncture. Kirschner's study did not have a great repercussion at the time. However, some authors later used his idea and developed needles with these characteristics as we will see. Below figure with examples of needles with side holes near the distal end.

Sise (1928)

While most publications at that time were regarding to the characteristics of the cutting tip of the needle, LF Sise suggested a pattern of innovative needle that, over time, was occasionally modified and also recommended by others. In 1928, this author signed two articles and, in the second of them published in the Journal of The American Medical Association (JAMA), reported his proposal for the design of a new spinal needle (figures below).

Sise stated that needles with long and sharp tips should not be used, as part of its orifice could be out of the subarachnoid space during puncturing, therefore a failed block could occur. Thus, he suggested a modification of the original Greene’s needle making its tip tapered and completely straight. Puncture through the skin, ligaments, and the dura mater was performed by an internal stylet in this needle. This stylet would have a thin and sharp edge, stretching for a few mm beyond the needle. In the figure we have the example of the tip of a needle similar to that described by the author.
Gertie Marx® (1990s)

Gertie Florentine Marx (1912-2004), an anesthesiologist, was born in Germany and immigrated to the United States in 1937 to escape from the rise of Nazism in her country and after the Jews were forbidden to attend German universities. She was one of the biggest boosters, promoters and defender of regional analgesia for labor in the middle of last century. She had remarkable performance in anesthesiology societies and specialized journals.

In the 1990s, the Gertie Marx® needles for neuroaxial anesthesia were developed by the International Medical Development™ to make up a complete set of artifacts for epidural, subarachnoid and for use in combined spinal-epidural anesthesia. It is noteworthy that this researcher is not responsible for the design of these needles were thus named in her tribute.

The spinal needle has a conical tip similar to Whitacre needle. But unlike the latter, has a lateral orifice shorter and distal to minimize the chance of its partial introduction in the subarachnoid space. In the figures below we have the representation of one of these needles and a comparison of the tip of this device over other spinal needles.

Among the epidural needles puncture of this mark, we have those similar of the Tuohy-Huber needles but are also available atraumatic conical tip needles similar to that suggested by Sprotte (figure below).


Hanaoka (1986)

The combined spinal-epidural anesthesia is gaining more space and adepts in obstetric analgesia and anesthesia. On this, we are able to associate the advantages of a spinal block with the presence of an epidural catheter for block extension or continuation if and when necessary. Unfortunately, the chances of complications inherent to each technique are also added.

The first association with a spinal epidural anesthesia was first described in 1937 by Soresi. This author, using the needles available at that time, made an epidural puncture and administered part of the anesthetic solution, and afterward, progressed this same needle to the subarachnoid space where it was administered another part of the anesthetic solution. This technique remained forgotten for many years. In 1979, Curelaru used it in a series of 150 patients by the technique of double puncture. Initially, an epidural catheter was passed into a lumbar intervertebral space and then a subarachnoid puncture was performed 1 to 2 spaces above. Again special needles were not described for those punctures. It is worth mentioning that this technique of "double puncture" is still one of the most used for the combined technique to the present. Next, in order to avoid the trauma secondary to a double puncture, Coates in England and, simultaneously, a group of Swedish researchers (Mumtaz, Daz and Kuz) described in 1982, the "needle-through-needle" technique (picture below). On this option of combined block an epidural puncture is performed and the needle is leased in the space. Then, another needle longer than the first is inserted in the subarachnoid space. Again it was not described the use of special needles except for the use of a longer spinal needle than usual.

However, in 1986, Hanaoka came up with the idea of a needle with innovative features for the realization of the combined spinal-epidural. It was a standard Tuohy-Huber needle but, in its turn, had another orifice aligned with its longest longitudinal axis close to its distal end. On this orifice, called "back hole", passed the spinal needle inserted through the interior of the epidural needle (figure below). Thus, the dural puncture was performed at a right angle rather than at angles of approximately 30 degrees as seen in the original "needle-through-needle" technique. This facilitates the subarachnoid puncture, increasing your chance of success. In fact, the concept of the back orifice in the Huber needle tip had already been patented by this inventor in 1953. However, Hanaoka was the first to report the combined technique with the use of needles with these characteristics.


Coombs (1987)

In 1987, Dennis Coombs, American researcher, filed a patent for a double-lumen needle for combined spinal-epidural anesthesia (figures below). He is the pioneer of the idea of performing this technique through a single puncture but without using the "needle-through-needle" method. In the following year and in separate publications, Eldor and Torrieri reported the use of this type of needle in clinical practice.


Cheng (1957)

In 1957, Peter Aiming Cheng proposed his epidural needle design. It was a short-bevel needle, similar to Hustead but with a diagonal cut a few millimeters from the tip so that it stayed bent. However, its great novelty was the fact that it was the first epidural needle marked with centimeters so that the operator could evaluate the real distance from skin to epidural space (figures below). This measure was intended to facilitate the determination of the length of the catheter placed. This needle has not obtained wide use and acceptance since it was described by some as heavy and difficult to use. However, the idea of marking the puncture needle remained and is present in many models currently available.


Lutz (1963)

With the great popularity of the conical tip needles in previous years it did not take long to arise a similar novelty to epidural needles. In 1963, Lutz described the first conical tip epidural needle (figure below). It was a device for single epidural puncture through which he was not able to place a catheter. Because of this, it did not achieve widespread use especially in obstetric patients. However his design is still commercially available until today being offered by some manufacturers.