Weighty Matters

In general surgical training, we are generally taught that adipose tissue is a bit of nuisance. Too much of it makes access difficult and healing too. When in touch with electrocautery it melts away, when in touch with sutures it rips apart. When present in ample quantities as a subcutaneous layer, you can expect a generous amount as an epicardial spread as well—and good luck with identifying the coronaries. You softly scratch it away with an eye blade and it starts to bleed diffusely—eagerly continuing to do so, unimpressed by protamine.

Back on the ward, fat tends to keep the attention of the surgeon in the form of “adipose tissue necrosis”—which is just a step away from the dreaded deep sternal wound infection. This necrosis adopts a fluid aggregate state and can be expressed through the incision looking like a substantial broth made from Oxo cubes with vegetable inlay and congealing drops of grease on top. Pray that the microbiology swab is (still) negative. Some surgeons like to fight it with prophylactic vacuum drainage or dressing for the first postoperative days, continuously sucking away the accumulating debris. So is fat really good for nothing?

With many of our everyday patients presenting more than an average share of adipose tissue, it is little wonder that basic scientists became increasingly interested. In this issue, we are publishing four articles (three cardiac[1] [2] [3] and one thoracic[4]) analyzing the various, mostly negative, effects of adipose tissue on postoperative outcome, and one more on the effects of omega-3-polyunsaturated fatty acids[5]—those are the supposedly good ones of flax, hemp, and piscine origin. As it seems, the biological functions of adipose tissue are much more wide ranging than its just being a well-meant energy depot for very bad times. Our board member, Stefan Dhein, has written a knowledgeable introduction[6] in which he summarizes the current knowledge about the auto-, endo-, and paracrine effects of the various and numerous “adipokines.” The academic surgeon will hopefully be delighted about this emerging field of scientific activity. The practical surgeon should take it as a message that the stupid yellow blebs are not so stupid after all, but full of actually quite fascinating molecules. Admittedly they remain a nuisance.

Looking back in history, fat has also been attributed with rather positive properties—as Julius Caesar, according to the Bard, remarked before:

Let me have men about me that are fat;

Sleek-headed men, and such as sleep o' nights:

Yond Cassius has a lean and hungry look;

He thinks too much: such men are dangerous!....

Would he were fatter! But I fear him not. [7]

Which, as we know, proved to be a big mistake.

• References

• 1 Rothe S, Busch A, Bittner H , et al. Body mass index affects connexin43 remodelling in patients with atrial fibrillation. Thorac Cardiovasc Surg 2014; 62 (7) 547-553
• 2 Rachwalik M, Zyśko D, Diakowska D, Kustrzycki W. Increased content of resistin in epicardial adipose tissue of patients with advanced coronary atherosclerosis and history of myocardial infarction. Thorac Cardiovasc Surg 2014; 62 (7) 554-560
• 3 Ivanovic B, Tadic M, Bradic Z, Zivkovic N, Stanisavljevic D, Celic V. The influence of the metabolic syndrome on atrial fibrillation occurrence and outcome after coronary bypass surgery: a 3-year follow-up study. Thorac Cardiovasc Surg 2014; 62 (7) 561-568
• 4 Fiorelli A, Vicidomini G, Mazzella A , et al. The influence of body mass index and weight loss on outcome of elderly patients undergoing lung cancer resection. Thorac Cardiovasc Surg 2014; 62 (7) 578-587
• 5 Wilbring M, Ploetze K, Bormann S, Waldow T, Matschke K. Omega-3 polyunsaturated fatty acids reduce the incidence of postoperative atrial fibrillation in patients with history of prior myocardial infarction undergoing isolated coronary artery bypass grafting. Thorac Cardiovasc Surg 2014; 62 (7) 569-574
• 6 Dhein S. Fat and the heart: a more and more complex interplay. Thorac Cardiovasc Surg 2014; 62 (7) 543-546
• 7 Shakespeare W. Julius Caesar. I, 2