Monday, March 19, 2007

Knot Really

Of all the strongly-held beliefs imparted to me in training (and the list is long, indeed), using which suture under what circumstance may be at the top of the list. Emphasis on "strongly" as the operative criterion. That various surgeons had widely divergent views on the matter didn't diminish the near religious intensity of those beliefs. Woe be to the trainee who even questioned it: and forget about actually making up your own mind. If you were working with Doctor X, you used his/her preferred suture. At some point, it's likely you'd hear each one's reasons. Everyone had an understandable basis, I suppose. It's just that it turns out most of them were wrong. Some stuff never really made any sense; other things changed as materials improved, so I guess the old guys should get a pass.

Before getting to the meat of the matter (I could make it a pretty long and ultimately boring post if I enumerated all the examples), here's one thing I'd bet each surgeon has had etched deeply into his/her sensibility: how long the "tails" ought to be when cutting suture. As if giving the most precious of gifts, generous beyond the call, the senior surgeon would allow a new intern to cut the suture he'd just tied. In tern, the young fellow/fellowette would tremulously apply the scissor beyond the knot and snip, knowing with near-certainty that the move would be followed by the loudly-declared "That's too long!" or "That's too short!!" In fairness, too short could lead to a knot untying itself (at least if poorly tied and/or finished off with too few throws [another imprint: how many throws is just right?]). The result, over time, is a stone-carved sense of proper appearance of those two little ends, variation from which can cause a physical sense of unease. It took me many years to realize: the suture may have been placed, for example, around a munch of muscle in closing an incision such that its entire length is well over an inch, maybe two. What possible difference can it make if the ends are a couple of millimeters "too long?" And now, I can tell you, tying and cutting knots laparoscopically -- which gives a very close and magnified view -- can distort one's sense of proportion beyond repair. But enough of minutiae.

The only time I've used wire suture on my own patients was on the trauma service at the county hospital. There, our chief of service insisted on it: wire suture was strong as hell and, more importantly for traumatic and therefore typically contaminated wounds, it was highly unlikely to become a nidus for infection. Despite the fact that tying it many times a day literally rubbed the ulnar aspect of our palms raw and often bloody, and that the knots tended to be uncomfortable (even though we carefully bent them downward) under the skin of the patients and frequently required later removal, it's what we used. Period. Embedded in my brain, the need to close such incisions with wire extended briefly into my early practice days until I was convinced (didn't take much) that the new strong-as-steel but soft and comfortable dissolving materials worked just fine. To his credit, the chief (one of my heroes!) later published a paper confirming the efficacy and he abandoned wire.

At our weekly conference wherein the chief residents on all the various surgical services presented their data, including all complications, one of my friends was profoundly excoriated for brazenly flaunting the party line and closing a long midline abdominal incision with a single running suture in the muscle layer. With no exceptions -- no matter the size and material of the sutures -- no one, NO ONE, closed that layer in any way but with single interrupted stitches, placed and tied one at a time, laboriously, plentifully. Having read some papers on continuous closure, Jerry thought it made sense and gave it a go. Sadly, being at the VA hospital, he unwittingly used nylon material that had been sitting around in storage, left there by George Washington not long after he'd crossed the Delaware River. Brittle and aged, it broke, resulting in a rather dramatic (but ultimately devoid of long-term consequences) reappearance of the man's innards, not in the operating room but in his bed. Yuck. The professors, on hearing the report, went ballistic: the stupidest thing they'd ever heard of. Reckless, idiotic, no understanding of wound healing. Righteous yada yada, indignant. Poor Jerry. Now an internationally respected and universally admired and loved academic surgeon, that was a bad day for him. Suffice it to say, very shortly after finishing training I came to close nearly all of my major incisions with a running suture and never -- not once -- had a reason to regret it. Not only does it save significant time, studies have shown healing is facilitated and pain is less. Who knew?

Wounds heal between sutures. In other words, the tissue actually grasped by the stitch, being squeezed, often doesn't get adequate circulation. More so, the tighter the stitch, the smaller the bite, the more closely placed to the neighboring one. Individually placed and tied sutures, in other words, potentially provide innumerable micro-zones of ischemia. With a running suture, there's essentially no crimped zone. You can, of course, screw anything up. The important thing, in my opinion, is to take larger bites than most people take, and to cinch up the suture gently, getting the edges just together. Otherwise, if I were letting an intern do it, I'd holler "too loose," or "too tight!!"

(Only the very hip will get the photo-pun. And I'm nothing, if not hip.)


Lynn Price said...

As always, you throw out an interesting post. I'm in the middle of writing a chapter where the doc is teaching med students how to do stitches on chicken legs - really happened when we were in the Amazon jungle - and find your comments helpful in giving me added reality.

As an old seamstress from another age, I always feared the running stitch because if one end came undone, bango, my daughter's prom dress could be in a heap on the dance floor. A lovely sight for her date, agonizing hell for Daughter. Even more agonizing hell for Mother. I assume that the surgeon's running stitch is far stronger and less likely to unravel than a seamstress', yes? If so, how?

Another question: Why do docs call it "throwing down" a stitch? Makes it sound like you have a bag of them and you reach in and toss one into an organ.

"(Only the very hip will get the photo-pun. And I'm nothing, if not hip.)"

God, I'm so uhip. I give. What's the pun?

Sid Schwab said...

lynn: the suture material I used for running closure was big and strong. #1 vicryl, to be specific. It's absorbable, meaning it entirely disappears, but only after at least a couple of months, by which time it's all healed. It's impossible to break the stuff, and it's quite thick so it won't pull through. Barring manufacturing defect (which I've never seen or heard of), and assumint the initial and final knots are well-tied, ain't no way it'll come loose.

"Throwing down" (not a universally used phrase, I'd say) refers, I think, to the act of tying each knot, as opposed to place the stitch in the first place. When tying one-handed, the loop is made and sort of thrown down to the knot with the index (or sometimes the middle) finger. Sling, push, pop.

And I'm waiting until I see if anyone gets it before explaining the pun.

Anonymous said...

Here's a hint: right click on the image and then go to [save image as]...

ps Dr. Schwab, I loved your book (I think I read it all in one sitting - couldn't put it down)... please keep your illuminating posts coming.

Lynn Price said...

"Here's a hint: right click on the image and then go to [save image as]..."

I got that when I clicked directly on the photo. I figured the guy was a rapper named Too Short. Being an old broad, I don't do rap, so I can only guess.

Thanks for the explanations, Sid. I've heard that term "throwing down" from any number of places.

Still loving your book. Wish I could just sit and eat it up in one sitting like Anon did. Lucky stiff!

Anonymous said...

on suturing: approximate, don't strangulate

Anonymous said...

I was told that there were two ways that the medical student can cut a suture: too long and too short. This is true.

One fellow student was set on getting things exactly right and was allowed by an attending doc to close. True to form, Dr. Attending yelled, "Too short! Too long! I want them one centimeter [pronounced the bizarro-surgeon way as "sahnnimeeter"], exactly!" He called for a sterile ruler. Still, the sutures ran 1.2cm, 0.9cm, 1.1cm... Student sees his surgical career fading incrementally with each millimeter (the sutures were plentiful, as Dr. Schwab notes, and the running commentary was interminable). At the end, the surgeon said "Good job!" and walked out laughing. Don't know what specialty the student ended up in.

Anonymous said...

Don't know what specialty the student ended up in.

Malpractice attorney.

Bongi said...

one thing i've learned in the blogosphere is that the surgical world is small. our old (very old) professor used to say centimeter in that same way, "sahnnimeeter". i just thought he was old and perculiar. once again i see there is nothing unique to us but rather a constant thread that binds us all together.

i feel a tear welling up in my eye...

Bard-Parker said...

I myself am a big fan of the double-stranded #1 PDS. The loop eliminates the need to tie in the corners and you can start one from either end and tie in the middle.
Of course if all else fails there is the old retention closure with the "dead man's stitch" of #2 nylon with cut up red rubber catheters.

Sid Schwab said...

Yep, been there, done those!

Anonymous said...

It must be a surgeon thing:
English speaking surgeons using the French pronunciation for "centimeter";
another favourite, of course, is "debridement".

Anonymous said...

My ortho surgeon used staples to close the wound. Because of a planned trip I had to ask him to remove them several days before it was scheduled. Have to say each snip (fourteen) smarted but was not unbearable! Now, nine months later, there's hardly a visible scar.

I finished your book in one setting, also! It was great. Love your blog and hope you write another book!

Dr. Rob Oliver said...

Sorry Sid, but Vicryl & other short-acting absorbables for closing laparotomy incisions have substancially higher hernia rates then PDS, Dexon, or the permanent sutures (steel, nylon, polyester). Your other comments I agree with 100%.

Sid Schwab said...

Hmm. I always thought of dexon and vicryl as interchangeable: both polyglycolic acid. Our hospital bought vicryl. I used #1 vicryl for running closure, and had no problems with it.