A severe attack of common sense

Needle in. Wire through the needle. Needle off over the wire. Catheter onto the wire. Catheter in. Wire out. If you have put a line into anybody in the last fortnight — central, arterial, a vascath, a PICC, a drain, a percutaneous trache, an ECMO cannula — you performed a Swedish radiologist's name, and the odds are you have never wondered whose.

He was alive until 1998. He could have been telephoned.

What the problem actually was

Before 1953 there were two ways to get a catheter into an artery, and both were bad. You could cut down and expose the vessel surgically — Seldinger's own description of that is “time-consuming, troublesome and may present certain risks”. Or you could puncture percutaneously with a very large needle, twelve to fifteen gauge, and thread a catheter down the inside of it. That worked, after a fashion, and it left a hole in the artery necessarily larger than the catheter filling it, which is an arrangement that bleeds.

The constraint underneath is hydraulic, and Seldinger said so himself in plain terms: by Poiseuille, flow through a long narrow tube varies with roughly the fourth power of the diameter. He was injecting contrast. A catheter that must fit inside a needle is a thin catheter, and a thin catheter is a slow one. The question was not only how to stop the bleeding. It was how to get a decent bolus of contrast into an artery before the picture was taken.

His answer inverted the geometry. Let the catheter be as large as the hole rather than smaller than the needle. The Swedish biographical dictionary puts the gain at catheters fifty to a hundred per cent wider, something like five times the flow, and injection times cut by about four fifths.

Three objects in his hand

The moment is documented, which is rarer than you would think, and it is documented by Seldinger himself in a retrospective essay he wrote in 1987. He had been trying a workaround of his own — a catheter with a side hole cut in it so a needle could pass through and protrude a millimetre or two past the tip — and it had just failed again.

After an unsuccessful attempt to use this technique I found myself disappointed and sad, with three objects in my hand — a needle, a wire and a catheter — and … in a split second I realized in what sequence I should use them.

Then the sequence, in his own beats, and it is longer than the version we teach: Needle in — wire in — needle off — catheter on wire — catheter in — catheter advance — wire off.

Asked afterwards where the idea came from, he said this:

I have been asked how this idea turned up and I quote Phokion, the Greek. “I had a severe attack of common sense.”

The contribution was the order, not the hardware

It is worth being precise about what was new, because he was precise about it. Wires were not new. Stig Radner, at Lund, had used a wire guide to stiffen catheters in 1948. Percutaneous puncture was not new; Peirce had published the large-needle method in 1951. Catheterisation of an exposed artery went back to Fariñas in 1941, and translumbar aortography to dos Santos in 1929. Seldinger cited all of them.

What was new was that the wire holds the hole open while the needle leaves. That is the whole of it. Every component was on the table already and had been for years; the invention was the order in which you pick them up. This is why his own account dwells on sequence and says almost nothing about equipment, and it is why the paper — nine pages in Acta Radiologica, volume 39, 1953 — is mostly six lettered steps and a diagram.

What his department made of it

Here is the part that your Swedish colleague may or may not know, and the part this piece is really about.

Seldinger wanted to take a doctorate. The obvious subject was the technique, and the obvious argument was the one the technique had already proved in practice: that every artery in the human body could now be reached by a simple percutaneous procedure. According to Greitz, his chief at the Karolinska radiology department did not think that was enough to form the basis for a thesis.

So he did something else. He spent the next decade applying his own access principle to the bile ducts, and defended a dissertation on percutaneous transhepatic cholangiography on 31 May 1966 — thirteen years after the paper that every hospital in the world was by then using daily. He took his docentur the following year at Gothenburg, not at Karolinska. On 1 January 1968 he became head of radiology at the hospital in Mora, the small town in Dalarna where he had been born, and he stayed there until 1986.

The arithmetic of recognition

I would rather give you dates than adjectives, so here they are. The paper is 1953. The first substantial international honour I can document is the Valentine Award of the New York Academy of Medicine in 1975 — twenty-two years later. The American Journal of Roentgenology gave him an eleven-page tribute in January 1984, with contributions from Charles Dotter among others. Uppsala gave him an honorary doctorate on 30 May 1984, thirty-one years after the paper, and from Uppsala rather than from Karolinska. Case Western Reserve made him a named professor of radiology in 1991, when he was seventy.

Set against that: in 1956, three years after Seldinger published the access method that made cardiac catheterisation an ordinary procedure, the Nobel Prize in Physiology or Medicine went to Forssmann, Cournand and Richards for cardiac catheterisation. That is not a complaint about the 1956 award, which was plainly deserved. It is an observation about what gets seen. The destination was a discovery. The road to it was a technique.

And on the Nobel question specifically, a word of discipline: you will occasionally see it claimed that Seldinger was nominated. Nomination records are sealed for fifty years, so for any plausible year the archive cannot yet be consulted. Anybody asserting it — in either direction — is asserting something they cannot know.

What we teach is not quite what he did

One last wrinkle, and it is a nice one for a Friday. What is now taught as the “traditional Seldinger technique”, with its deliberate through-and-through puncture of both vessel walls, is not what Seldinger illustrated. His 1953 diagram shows a single anterior wall puncture. The double-wall version appears to have arrived by conflation with the Cournand needle, which was in concurrent use, and it has carried his name ever since.

So the eponym has drifted from the man twice over. We attribute to him a technique whose components he did not invent, in a form he did not describe, under a name he never used — he called it nothing at all, and in Sweden it was known for years simply as S-metoden, the S-method.

Mora

His mother's family were the clockmakers of Mora, which is a real trade and not a decorative detail: the Mora clock is a Swedish object the way the Dala horse is, and the family ran the mechanical workshop in the town. One of his great-grandfathers is the bearded watchmaker in Anders Zorn's painting Djos Mats, and Zorn described the men of that workshop as technical geniuses. The family name was Svensson before it was Seldinger.

He went back there in 1968 and ran a district radiology department for eighteen years, and he died in his house in Mora in February 1998, at seventy-six. Whether the return was retreat, preference or simply going home, no source says, and I am not going to invent a motive for a man who declined to supply one himself.

What can be said is this. Somewhere in your unit tonight, probably within the hour, somebody will hold a needle, a wire and a catheter, and will use them in the order a disappointed Swede worked out while standing in a Stockholm X-ray department in 1953 — the order that his own department thought too slight to build a doctorate on.