You may have noticed that I haven’t been paying as close attention to the ol’ blog as usual over the last three days, leading to a bit of hyperbole in the comments section of at least one post without my responding until today. Indeed, here’s a secret: Most of the posts that have appeared since Friday were written Thursday or earlier and scheduled.
My wife happened to have some time off; so I took a rare three-day weekend off work. We took a road trip to Philadelphia to check out an exhibit at the Franklin Institute that we both had wanted to see before it left Philadelphia: Gunther von Hagens’ Body Worlds. As a surgeon, I found it to be a fascinating experience, albeit a vaguely troubling one.
For those not familiar with Body Worlds, it’s an exhibition of real human bodies that have undergone the process of plastination and are dissected and posed in a way that shows various aspects of their anatomy. People donate their bodies to anatomist Gunther von Hagens’ Heidelberg-based Institute for Plastination, which offers plastinated specimens for educational use and puts together the Body Worlds exhibition. Here is a description of the plastination process found on Franklin Institute website:
A process at the interface of the medical discipline of anatomy and modern polymer chemistry, plastination makes it possible to preserve individual tissues and organs that have been removed from the body of the deceased as well as the entire body itself. Like most inventions, plastination is simple in theory: in order to make a specimen permanent, decomposition must be halted. Decomposition is a natural process triggered initially by cell enzymes released after death and later completed when the body is colonized by putrefaction bacteria and other microorganisms. By removing water and fats from the tissue and replacing these with polymers, the plastination process deprives bacteria of what they need to survive. Bodily fluids cannot, however, be replaced directly with polymers, because the two are chemically incompatible. Dr. Gunther von Hagens found a way around this problem: In the initial fluid-exchange step, water in the tissues (which comprises approximately 70% of the human body) and fatty tissues are replaced with acetone, a solvent that readily evaporates. In the second step, the acetone is replaced with a polymer solution.
The trick that first proved to be critical for pulling the liquid polymer into each and every cell is what he calls “forced vacuum impregnation.” A specimen is placed in a vacuum chamber and the pressure is reduced to the point where the solvent boils. The acetone is suctioned out of the tissue at the moment it vaporizes, and the resulting vacuum in the specimen causes the polymer solution to permeate the tissue. This exchange process is allowed to continue until all of the tissue has been completely saturated–while a matter of only a few days for thin slices, this step can take weeks for whole bodies.
The second trick is selecting the right polymer. For this purpose, “reactive polymers” are used, i.e., polymers that cure (polymerize) under specific conditions, such as the presence of light, heat, or certain gases.
The process is summarized thusly:
The invention of plastination is an aesthetically sensitive method of preserving meticulously dissected anatomical specimens and even entire bodies as permanent, life-like materials for anatomical instruction. The body cells and natural surface structures retain their original forms and are identical to their condition prior to preservation, even at a microscopic level. The specimens are dry and odorless, and remain unchanged for a virtually unlimited amount of time, making them truly accessible. These characteristics lend plastinated specimens inestimable value both for training prospective doctors and for educating non-professionals in the field of medicine.
The results of this process are truly astonishing. Meticulously dissected human specimens are shown posed in a dynamic fashion. Examples included a hurdler posed in mid-leap, a basketball player in mid-dribble, a pair of figure skaters, the man lifting the woman above him, her back arched, a chess player sitting and contemplating a chessboard. Each of these were dissected in a unique way to show muscles, internal organs, etc. in a different light. To me it was clear that a lot of this was designed to be more art more than science or education.
It was profoundly unsettling to come face-to-face with these specimens. Because of the plastination process, they were more like statues than cadavers–incredibly detailed anatomic statues, but statues nonetheless. They almost don’t look real. I had to remind myself that these were real cadavers, that these had once been real people with lives, hopes, and dreams like everyone else. I hadn’t experienced this feeling, this need to remind myself of the former humanity of these shells, since my first year in medical school, when I took Gross Anatomy for the first time. The smell of the formalin preservative, rubberiness of the preserved tissues, gray and unyielding unlike living flesh, had forced me to remind myself of the same thing. It was somewhat easier then, though, because the cadavers we were dissecting, even though preservation had rendered the bodies rubbery, unyielding, and rather greyish, still looked like cadavers. Here, the bodies were solidly impregnated with various colored plastics to highlight their anatomy.
Whether through curiosity, reverence, or a combination of the two, the crowd, which started out rather boisterous, seemed to become more quiet and attentive as we moved through the exhibit. Even from teenagers, rude jokes were not to be heard. Also, perhaps it was because of the seeming unreality of these formerly living statues that people, including me, had no qualms about putting their faces mere inches from the cadavers that weren’t in glass cases to take a closer look. Touching was not allowed, but people came about as close to touching the specimens as they could without actually doing it. The specimens exuded a faint smell that seemed to be a mixture of plastic and preservative, but it was only noticeable with some specimens and very faint. When I moved in to get a closer look, I couldn’t help but try to identify individual structures. Median nerve? There it is! Where’s the subclavian artery? There! How about the celiac trunk? Found it!
Whether art, science, or education, this exhibit managed to surprise even me, a surgeon. I’ve seen human anatomy in the O.R. and in the anatomy lab, but I’ve never seen it like this before. For example, one specimen had the entire nervous system carefully dissected out, with organs and muscles that would get in the way removed. The specimens that fascinated me the most were the ones in which the vasculature had been injected in such a meticulous manner that every blood vessel could be visualized right down to the capillary. Somehow, the anatomists could then carefully digest away all the surrounding tissue, leaving casts of the vessels and capillaries. I could see the vasculature as I had never seen it before, either in the O.R. or in any anatomy or surgery textbook. The capillaries appeared as feathery tufts resembling red clouds that permeated the entire body. The most striking example of this was a display in which a man, woman, and child had been treated and posed as a happy family, with the man and woman side-by-side and the child sitting on the man’s shoulders.
Perhaps the most difficult to stomach to me was a pregnant woman, who had been posed reclining, the wall of the uterus opened to display the fetus of eight months gestation. A sign explained that the woman had donated her body knowing that she had a fatal condition that might kill her before she gave birth. It did, and apparently doctors were unable to save the baby. Surrounding her in the gallery was a collection of plastinated embryos and fetuses at different stages of gestation. What was unnecessary was the collection of plastinated fetuses with various abnormalities, including hydrocephalus, anencephaly, and Siamese twins. My wife complained that they lent an air of a freak show to this whole part of the exhibit, and I had to agree.
One area where the plastination process seemed to be of less utility is in the preservation of individual organs, of which there were many specimens displayed. Having seen these organs in situ in living human bodies, I couldn’t help but notice that, in comparision to the whole cadaver specimens, preservation and plastination process seemed to have robbed these organs of all their color. For example, the human liver is generally a reddish-brown color. Plastinated livers on display in this exhibit were pale, almost white. To me, again, they didn’t look real.
One thing that was apparent was the evolution of von Hagen’s approach to producing specimens. Earlier in the exhibit, the displays were more straightforward: a man standing, the basketball player in mid-dribble, the chess player. These were the older pieces, dating back to the mid-1990’s. However, towards the end of the exhibit, the more recent pieces appear to be more daring and intentionally artistic, including a gymnast on a balance beam, a pair of figure skaters, and a woman kneeling and releasing two doves, both of which had been treated to show their blood vessels, as the man, woman, and child had been.
I left the exhibit somewhat conflicted. On the one hand, many of the specimens, through their meticulous and artistic dissection, had shown me human anatomy in a manner I had never imagined possible. On the other hand, I couldn’t help but feel that there was something exploitive about the whole endeavor; given the sold-out attendance and the not inexpensive price for tickets, plus all the merchandise on sale in the obligatory gift shop that the exhibit exited into, clearly this exhibit is raking in money hand over fist.
Even so, given the way that this exhibit sparked so much interest in anatomy in the children visiting it, perhaps it’s worth a little exploitation.
ADDENDUM: It appears that the Body Worlds exhibit is heading to PZ‘s neck of the woods. It’s going to St. Paul, MN on May 5.
