Department of Vascular Surgery, Demokritos University of Thrace, Alexandroupolis, Greece Email: mlazarid{at}med.duth.gr
Sir,
We read with interest the article by Bonucchi et al. [1] regarding the preferred vascular access in diabetic patients. The authors correctly reported that diabetic patients commonly display medial calcifications of the peripheral arteries. The latter, when haemodynamically significant, hinder the maturation process in distal (wrist) AV fistulas (AVF) by preventing the compensatory hypertrophy of the feeding artery and the subsequent increase in the arterial flow. Medial calcifications known as Moenckeberg's sclerosis are, however, rare in the brachial artery. On the basis of the previous concept, some authors express little enthusiasm for the creation of forearm AVF in diabetics [2]. The construction of proximal upper-arm AVF as an initial approach has been suggested instead [1,3]. However, articles with opposite views were either misinterpreted or not included in Bonucchi's paper, as Lin's study reporting that diabetes was not significantly associated with primary failures of radiocephalic fistulas [4], or Sediacek's data reporting that diabetics are as good candidates for distal AVF placement as patients without diabetes [5]. Additionally, in the HEMO study diabetes did not correlate with the likelihood of having a fistula in the upper arm rather than the forearm, reflecting the view of the majority of surgeons on this topic [6]. In many diabetics a preoperative plain X-ray of the hand reveals absence of medial sclerosis and therefore the construction of a distal AVF is feasible. We believe that the following algorithm helps in decision-making:
What access in diabetics?
Medial sclerosis (+)Avoid distal AVF, prefer elbow AVF.
Medial sclerosis (-)DOQI [7] order of preference.
In Bonucchi's article the authors suggest performance of upper arm plain X-ray to detect calcified vessels (suggestion no. 3) and prefer elbow AVF as initial access (suggestion no. 6). We believe that preoperative plain hand X-ray is more useful, as proximal calcifications are rare. In our view the only cause justifying the initial creation of an elbow AVF, when cephalic vein is normal, is the presence of severe medial calcification at wrist (Fig. 1). However, functional distal AVF have also been reported and in the presence of ultrasound detected calcifications [5].
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Nephrology Dialysis and Transplantation, University Hospital, Modena, Italy Email: bonuckidney{at}libero.it
Sir,
We thank Dr Lazarides and colleagues for their comments. It is true that editorials score very low in the evidence-based medicine rank of publications [1], but the aim of editorial notes is mainly to stimulate discussion, based on different opinions, eventually leading to new evidence.
As pointed out in their letter, the definition of upper arm (instead of upper limb) is wrong and we agree with the fact that vascular calcifications should be looked for at the forearm by means of plain X-ray. I take responsibility for this mistake.
On the other hand, it is evident that our purpose was to draw attention to some special features in the treatment of the diabetic patient suffering from uraemia; their treatment indeed differs from that of other patients, their survival is short without transplantation and their medical burden is extremely high, especially when vascular access fails.
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