Editorial Comment: When durability is overlooked

Abstract

The paper of Azuma et al. [1] described the results of a nonrandomized, non-prospective, multicentre study (35 centres), in which the results of a so-called next generation, customized, precurved and fenestrated endograft were presented. The device was used for the repair of aortic arch aneurysms with challenging anatomy, that is to say, short proximal necks of <20 mm. All patients were operated upon electively. This homemade device consists of an inner skeleton (self-expandable Z-stents) sutured to an outer graft made from polytetrafluoroethylene. It possesses eight types of fenestrations. Deployment is facilitated by a number of peculiarities. Concerning patient selection, the authors asserted that participating physicians selected patients with ‘serious risk factors for open surgical repair’. Given that pulmonary, cardiac and renal function was not specified or quantified in the manuscript, it is unclear exactly what this means. The fact that general anaesthesia was used in most of them probably indicates that their vital functions were not so deficient at all. I am surprised by the argument that in the most ‘challenging’ cases (for me entering the arch is always challenging), ‘patients did not have access to any alternative method for preventing aneurysm rupture except through the use of the fenestrated stentgraft’. This is, of course, the result of the specific study design, but it appears that the patients were not offered many alternatives. This is curious at the very least. The paper starts with an introduction in which the authors announce that conventional repair of arch abnormalities is associated with a mortality of 6–20% and a stroke rate of 12%. In doing so, they refer to a paper that did not mention the words ‘mortality’ or ‘stroke rate’! It would be much more legitimate to refer to contemporary series with excellent and verifiable results, such as that of Yutaka et al. [2], who reported a mortality of 4.7%, with 3.5% permanent neurological deficit and 6.7% transient neurological deficit; or another recent paper of Zierer et al. [3], who reported 5% mortality, 3% permanent neurological deficit, 4% temporary neurological deficit and a freedom from reoperation of 97% at 8 years. The significance of a 99.2% technical success rate is uncertain. If patients are well selected, one should reach 100% because, as I understand it, these devices are deployed with one’s eyes closed, such that even a non-interventionalist could use it successfully. When I see the images of the device with the fenestrations in it, I wonder how large these holes are and how many fenestrations were used in each graft. This information is missing. If one had to use extra commercially available devices to reinforce the distal aneurysm portion (which was ‘occasionally’ the case, again without specifying how many times), it could mean that the device has serious shortcomings. What about the results? Hospital mortality is 1.5%. The initial success rate (and it is unclear to the reader over what time frame this was assessed) was 95.4%, yielding 4.6% type I and III endoleaks vs. 13.7% with the first-generation device. Stroke occurred in only 1.7% of cases; it was not segregated into permanent and transient deficits. These are simply very promising and encouraging immediate results. But what will happen with these aneurysms and stent grafts after 3 months, 1 or 2 years or longer? A very weak point of this study, perhaps the weakest, is that there are no follow-up data available. This 2-year study started in January 2010. Considering the time required for data gathering and analysis, writing and reviewing, one can deduce that the follow-up period must be very short, almost nonexistent. It is not yet known whether endoleaks, aorto-enteric fistulas or even aortic rupture might occur. Durability, the capability of maintaining the integrity of the structures to perform the functions for which they are designed and constructed, is overlooked here. ‘Thus this device opens the door for innovative implant strategy in arch aneurysms’. This statement is questionable based on the results of this study. Making things easier, less invasive and less complex by introducing new techniques is one of the principal goals in surgery. It may even differentiate good surgeons from not so good surgeons. But the absolute condition is that the same excellent and durable results can be proved using the proposed new technique. In biology, ecology, finances, engineering, cancer prevention, energy problems, education and in life in general, long-term vision is critical. Here, there is no doubt that scrupulous follow-up was undertaken, but there is simply no follow-up mentioned. As Dwight D. Eisenhower once said, the train of future will run over us if we lie down on the tracks of history. However, to me the introduction of fenestrated endografts for the treatment of arch aneurysms is only like the passing of an empty train; quick and without any impact for the future.