Invited Commentary

Abstract

German researchers have always been very fond of enigmata. They even called one of the most sophisticated encrypting machines ever simply “Enigma.” It was first patented in 1918 and was used widely during the Second World War until its code system was finally broken at Bletchley Park [1Hinsley F.H. Stripp A. Codebreakers: The Inside Story of Bletchley Park. Oxford University Press, Oxford, UK1993Google Scholar]. One enigma still unsolved 70 years later is the blood supply of the spinal cord and its protection during operations on the thoracic or thoracoabdominal aorta. Interestingly enough, the crucial steps to understand both the Enigma machine and spinal cord blood supply were taken by Poles: Marian Rejewski and Albert Adamkiewicz, respectively. Pig models have been used for a long time for further understanding, despite of some basic anatomic differences [2Wadouh F. Arndt C.F. Metzger H. Hartmann M. Wadouh R. Borst H.G. Direct measurements of oxygen tension on the spinal cord surface of pigs after occlusion of the descending aorta.J Thorac Cardovasc Surg. 1985; 89: 787-794PubMed Google Scholar, 3Etz C.D. Kari F.A. Mueller C.S. et al.The collateral network concept: a reassessment of the anatomy of spinal cord perfusion.J Thorac Cardiovasc Surg. 2011; 141: 1020-1028Abstract Full Text Full Text PDF PubMed Scopus (212) Google Scholar]. An academic debate regarding the role of the so-called artery of Adamkiewicz [4Adamkiewicz A. Die Blutgefässe des menschlichen Rückenmarkes I: Die Gefässe der Rückenmarkssubstanz. Sitzungsberichte der kais. Akademie der Wissenschaften zu Wien.Math Naturwissenschaftl Classe. 1881; 84: 469-502Google Scholar, 5Adamkiewicz A. Die Blutgefässe des menschlichen Rückenmarkes II: Die Gefässe der Rückenmarlsoberfläche. Sitzungsberichte der kais. Akademie der Wissenschaften zu Wien.Math Naturwissenschaftl Classe. 1882; 85: 101-130Google Scholar] has been ongoing, including the respective protective approaches derived from the defended opinion [6Wadouh F. Arndt C.F. Oppermann E. Borst H.G. Wadouh R. The mechanism of spinal cord injury after simple and double aortic cross-clamping.J Thorac Cardiovasc Surg. 1986; 92: 121-127PubMed Google Scholar, 7Griepp R.B. Ergin M.A. Galla J.D. et al.Looking for the artery of Adamkiewicz: a quest to minimize paraplegia after operations for aneurysms of the descending thoracic and thoracoabdominal aorta.J Thorac Cardiovasc Surg. 1996; 112: 1202-1215Abstract Full Text Full Text PDF PubMed Scopus (247) Google Scholar, 8Heinemann M.K. Brassel F. Herzog T. Dresler C. Becker H. Borst H.G. The role of spinal angiography in thoracic aortic surgery: myth or reality?.Ann Thorac Surg. 1998; 65: 346-351Abstract Full Text Full Text PDF PubMed Scopus (71) Google Scholar]. Now, Haldenwang and colleagues have applied the porcine model to simulate modern surgical strategies [9Haldenwang P.L. Prochnow N. Baumann A. et al.Spinal cord ischemia after selective cerebral perfusion in a porcine “frozen elephant trunk” simulation model.Ann Thorac Surg. 2015; 99: 1624-1631Google Scholar]. Given the background of the previous studies, it is not so surprising that the lower (lumbar) regions were more susceptible to ischemic damage even after indirect (selective cerebral) perfusion at moderate hypothermia (28°C). Some perfusion is probably almost always better than none, and the colder the better is still valid for tissue protection. This report nicely shows that even seemingly less invasive techniques such as endovascular stent-grafting are still troubled by one of the most enigmatic enigmata in medicine. Definitive deciphering is still bound to take a while, and it is to be hoped that this group will continue its valuable research. Spinal Cord Ischemia After Selective Cerebral Perfusion in a Porcine “Frozen Elephant Trunk” Simulation ModelThe Annals of Thoracic SurgeryVol. 99Issue 5PreviewThe “frozen elephant trunk” procedure (FET) represents the therapy of choice for extended aortic diseases. The aim of our study was to analyze whether 90 minutes of selective cerebral perfusion (SCP) at 28°C followed by permanent occlusion of the thoracic segmental arteries (TSA) would cause spinal cord ischemia in a porcine model. Full-Text PDF