Complications associated with hemodialysis vascular access procedures: the case for a classification.

Abstract

For a valuable quality assessment of health care deliv-ery, relevant data on outcomes must be obtained in astandardized and reproducible fashion to allow com-parison among different centers, between differenttherapies and within a center over time.Complicationdata are an important componentof outcome data.Any classification system used must be clear and con-cise so that reporting standards between the varioussubspecialties may be comparable. Otherwise, whenanalyzing the medical literature meaningful and reli-able comparisons are not possible (1).Today, physicians representing several specialties areperforming vascular access procedures. Unfortu-nately no one specialty uses a comprehensive classifi-cation system that is useful and reproducible for all.The absence of consensus within the surgery, radiol-ogy and nephrology communities on the best way toreport vascular access complications has hamperedproper evaluation of the vascular access work and im-peded progress in this field. The Clinical PracticeCommittee of American Society of Diagnostic and In-terventional Nephrology (ASDIN) has written a posi-tion statement on the “Classification of ComplicationsAssociated with Hemodialysis Access Procedures” inan attempt to rectify this problem by decreasing sub-jectivity in the use of a classification system (2).Vascular access procedure-related complications arecategorized first by the type of event and then by theseverity. Ten vascular access procedure-related com-plications are identified and then graded on a scale ofone through four, in a similar manner described bythe Society of Interventional Radiology (SIR) classifi-cation scheme (3). As opposed to the surgical classi-fication scheme, in which all adverse events occurringwithin thirty days are considered to be post-operativecomplications, the ASDIN classification scheme doesnot include complications which are not directly re-lated to a percutaneous procedure (4).The position statement is well written and very thor-ough. It provides an excellent, comprehensive frame-work for identifying all vascular access procedure-related complications. However, it does not define theexpected complication rates and thresholds. In orderfor any such system to be useful in clinical practice,quality assurance, or clinical research, the ranges andacceptable limits of complications in clinical practicemust be established. This comprehensive classification may be consideredby some to be too cumbersome for practical use andmay not be widely accepted by other specialties per-forming the same procedures. Vascular access proce-dures are only a part of the spectrum of proceduresperformed by vascular surgeons and interventionalradiologists. The Society of Vascular Surgery and theSociety of Interventional Radiology may not find thisclassification scheme applicable to their fields on thewhole.The Vascular Access Society (VAS) and the VascularAccess Society of the Americas (VASA) welcome theproposal of ASDIN to spread knowledge of their po-sition statement on complications of vascular accessprocedures among their members. This documentprovides the basis of cooperation among specialistsdealing with the same daily work, and it will hopefullyallow to better compare data of future publications inthis field. Any classification system must be validated. Accept-ability and reproducibility of any classification systemmust be documented, including centers in the UnitedStates and around the world. It would be necessary tosurvey practitioners involved in vascular access pro-cedures and assess if the criteria for reporting com-