Published online before print September 27, 2012, doi: 10.3174/ajnr.A3360
AJNR 2012 33: E129

R.A.P. Falero^a and O.L. Piloto^a
aDepartment of Neurosurgery
Hospital Hermanos Ameijeiras
La Habana, Cuba

When one reads “Age-Related Complications following Endovascular Treatment of Unruptured Intracranial Aneurysms,” one should expect an article that focuses on unexpected events, strictly associated with the aging process during an endovascular procedure.¹

Elderly patients who undergo invasive procedures are prone to complications, mostly related to atherosclerotic hardening and plugging of the arteries, arrhythmias, autoregulation disturbances, cardiovascular insufficiency, and endocrine and renal failure, among others related to muscle weakness and degenerative osseous changes. Although there are some controversies about this subject,² we agree with the predisposition of elderly people to complications in surgical and endovascular procedures,^2,3 but we do not think the design and results of Khosla et al¹ are strong enough support this predisposition.

Of the 110 complications, 41 (37%) were major. Among them, 26 (6.6% of all procedures) did not result in neurologic deficits at discharge, and these included temporary neurologic deficits (n = 13, 3.3%), subarachnoid hemorrhage (n = 8, 2.0%), acute anemia requiring transfusion (n = 3, 0.8%), seizures (n = 1, 0.25%), and 1 patient with an occlusion of the common femoral artery requiring thrombectomy (0.25%).

According the previous data, there was a significant statistical difference between nonelderly and elderly patients (7.4% versus 17%), but this was general and nonspecific information. The authors gave only details about the ones that might be aggravated by the aging process.

We found some inconsistencies in this analysis. For example, temporary neurologic deficits outnumbered other complications, but how can we explain them? During endovascular procedures, distal embolism or vasospasm is the most common cause of transient deficits; therefore were the intravascular thrombi or emboli, which occurred in 30 patients (7.6%), really asymptomatic? Could the authors provide any other plausible reason for these deficits, or could they just be secondary to the known difficult arterial navigation in elderly patients? However, even if this was the actual reason, why use “compromised vascular reserve” as an explanation? Then, what criteria did the authors use to differentiate these cases from the ones with neurologic deficits after the procedure: 13 patients (3.3%) with ischemic infarctions and 2 patients (0.5%) with fatal infarctions?

On the other hand, why were subarachnoid hemorrhages, acute anemia, or seizures increased in the elderly group, or were they just unwanted but “expected” results of the endovascular procedure? We cannot see, either, the relationship between age and increased risk of this therapy in this group.

Regardless of these opinions, the high proficiency of Khosla et al¹ in dealing with this complex medical problem is clear; therefore, we encourage them to continue the research into this subject with a prospective and well-designed study.

References

1. Khosla A, Brinjikji W, Cloft H, et al. Age-related complications following endovascular treatment of unruptured intracranial aneurysms. AJNR Am J Neuroradiol 2012;33:953–57 » Abstract/FREE Full Text
2. Ryttlefors M, Enblad P, Kerr RS, et al. International subarachnoid aneurysm trial of neurosurgical clipping versus endovascular coiling: subgroup analysis of 278 elderly patients. Stroke 2008;39:2720–26 » Abstract/FREE Full Text
3. Johansson M, Norback O, Gal G, et al. Clinical outcome after endovascular coil embolization in elderly patients with subarachnoid hemorrhage. Neuroradiology 2004;46:385–91 » CrossRef » Medline

Reply

Published online before print September 27, 2012, doi: 10.3174/ajnr.A3364
AJNR 2012 33: E130

A. Khosla^a, W. Brinjikji^a, H. Cloft^a, G. Lanzino^a and D.F. Kallmes^a
aDepartment of Radiology
Mayo Clinic
Rochester, Minnesota

We greatly appreciate the comments of Drs Falero and Piloto regarding our article “Age-Related Complications following Endovascular Treatment of Unruptured Intracranial Aneurysms.” In our article, the most common complication, intravascular thrombus or embolus without substantial neurologic compromise at hospital dismissal, was considered minor. Temporary neurologic deficits were the most common major complication in our study population. In our analysis, as shown in Table 2 of the article, nonelderly and elderly patients had rates of complications that were not significantly different from each other. We did not delve into the causes of temporary neurologic deficits because there was no significant difference between elderly and nonelderly patients. It is likely that intraprocedure thrombus and embolus played a role, but not more than they do in nonelderly patients.

In addition, we noted in our article that major complications without neurologic deficits included such complications as temporary neurologic deficit, subarachnoid hemorrhage, seizures, and anemia. As stated above, these complications were listed together as major complications without neurologic deficits and showed no significant difference between elderly and nonelderly patients.

We focused on major complications, particularly with neurologic deficits. It was noted that these were significantly more common within the elderly population. These included ischemic infarctions, both nonfatal and fatal. We attributed these complications in particular to the diminished vascular reserve within the elderly population. However, as you state, diminished vascular reserve is only 1 of the contributing factors to the increased complication rate. We agree with you that elderly patients do have more tortuous vasculature and increased atherosclerosis, making them more prone to complications, particularly major complications with neurologic deficits.

Taken together, our findings should provide guidance to patients and providers regarding the nature and extent of the risk associated with endovascular aneurysm therapy in the elderly. We agree that this topic warrants further investigation and a prospective trial may be of benefit. Since 2008, we have been examining outcomes prospectively of treated and untreated aneurysms and will be presenting the results when the analysis is complete.