In Reply

We regarded it as our task to present level I evidence for the interventional acute treatment of ischemic stroke, which has become available for the first time in almost 20 years, and to explain the ensuing consequences for stroke management and neuroradiological imaging (1).

However: in studies of mechanical thrombectomy (MT), IV-rtPA was the standard for all patients except those with contraindications.

When such contraindications did not simultaneously rule out MT, this procedure was used without IV-rtPA. None of the studies was designed to compare MT plus IV-rtPA with MT alone.

In this setting, what generally applies is as follows: the absence of a difference does not prove equivalence, and neither does it prove non-inferiority. It therefore remains true that we have level I evidence for combined therapy IV-rtPA plus MT in the patient groups described.

The following issue is another one in which we probably do not disagree much with what Koch writes in his letter: no one wants to withhold MT from a patient with proximal vascular occlusion and substantial neurological deficit.

However, it is our responsibility to apply the new method in a targeted fashion and to remain as close to the protocols used in the study as it is possible in clinical practice. It cannot be in our patients’ interest to use MT uncritically far beyond the 6 hours—for example, because of lengthy transport times.

In order to identify such potential problems as early as possible (and also in order to establish the conditions under which very late recanalizations are safe and effective in clinical practice) we would ask for further studies and, simultaneously, very strict quality assurance, such as is possible by means of the German Stroke Registry, combined with the database of the DGNR/DeGir.

Our position is less close to that of Kiesewetter. We agree only in one aspect: even after MT has been identified as an evidence based extension of acute therapy after ischemic stroke, a whole lot remains to be done—even after therapy with IV-rtPA and MT, the assumption is that 50% of patients who have had a stroke will continue to have substantial impairments.

It is therefore our credo that it is important to support stroke research and to ensure that basic research is supported on the one hand, and that as many hospitals with stroke units include their patients in clinical studies, on the other hand.

With regard to hemodilution, evidence for positive effects in ischemic stroke is lacking (2).

The relevant meta-analysis provided neither indications for improved survival nor for functional recovery after ischemic stroke. On the contrary, there is hard evidence that hemodilution with HAES is nephrotoxic in critically ill patients and increases mortality (3).

For completeness’s sake we wish to add that HAES is now contraindicated in intracranial or cerebral hemorrhage (4), for the reasons explained. An attempt at cure using HAES cannot be recommended in ischemic stroke.