Regarding "derivation and Validation of a Practical Risk Score for Prediction of Mortality after Open Repair of Ruptured Abdominal Aortic Aneurysms in a U.S. Regional Cohort and Comparison to Existing Scoring Systems".

We read with interest the article by Robinson et al.1Robinson W.P. Schanzer A. Li Y.F. Goodney P.P. Nolan B.W. Eslami M.H. et al.Derivation and validation of a practical risk score for prediction of mortality after open repair of ruptured abdominal aortic aneurysms in a U.S. regional cohort and comparison to existing scoring systems.J Vasc Surg. 2013; 57: 354-361Abstract Full Text Full Text PDF PubMed Scopus (69) Google Scholar Several series have now questioned the validity of the Glasgow Aneurysm Score, Hardman Index, and Vancouver score in the prediction of outcome after ruptured abdominal aortic aneurysm (RAAA).2Leo E. Biancari F. Nesi F. Pogany G. Bartolucci R. De Pasquale F. et al.Risk-scoring methods in predicting the immediate outcome after emergency open repair of ruptured abdominal aortic aneurysm.Am J Surg. 2006; 192: 19-23Abstract Full Text Full Text PDF PubMed Scopus (36) Google Scholar, 3Tambyraja A.L. Lee A.J. Murie J.A. Chalmers R.T. Prognostic scoring in ruptured abdominal aortic aneurysm: a prospective evaluation.J Vasc Surg. 2008; 47: 282-286Abstract Full Text Full Text PDF PubMed Scopus (40) Google Scholar The authors have now also demonstrated a lack of external validity for the Edinburgh Ruptured Aneurysm Score. These four risk-scoring instruments were all derived from clinically diverse Scottish, Australian, and Canadian specialist and nonspecialist vascular practices in an era of exclusively open surgical repair for RAAAs. Poor performance in a contemporary series of selected American patients undergoing open repair of RAAAs, that also offers emergency endovascular aneurysm repair is unsurprising. Twenty years of clinical research has failed to clarify whether outcome in patients with RAAAs can be predicted accurately. The existing literature suggests there are patient-related preoperative variables associated with perioperative death after AAA rupture. However, it must be noted that population-related, institutional-related, health systems-related, and surgeon-related variables have a profound effect on outcome, too.4Dueck A.D. Kucey D.S. Johnston K.W. Alter D. Laupacis A. Survival after ruptured abdominal aortic aneurysm: effect of patient, surgeon and hospital factors.J Vasc Surg. 2004; 39: 253-260Google Scholar, 5Tambyraja A.L. Rodriguez-Lopez J.A. Ramaiah V. Diethrich E.B. Chalmers R.T. Institutional differences in endovascular aneurysm repair and aneurysm morphology.World J Surg. 2012; 36: 2738-2741Crossref PubMed Scopus (4) Google Scholar When faced with such variability, the goal of a precise, reliable instrument with generalizable validity seems unattainable. There are certain universal deficiencies common to the application of all scoring systems. Selection bias in the recruitment of patients to the original data set upon which a scoring instrument is derived can impair performance. The performance of a scoring system is said to work best when it is customized to the behavior of a local environment and population. As a result, our own risk modeling was unique and highly specific toward our data. When applied to data from other centers, it will fail to demonstrate the same good fit. Furthermore, with the introduction of endovascular repair of RAAAs, and the potential improvements in patient survival, risk-scoring data sets require further analysis, remodelling, or recalibration to ensure predictive power is maintained. The quality and utility of the Vascular Study Group of New England (VSGNE) data is irrefutable. Although the number of patients turned down for surgical intervention and the proportion treated with endovascular aneurysm repair would enhance interpretation of the data, this series is a step in the right direction to develop accurate modern risk stratification tools for patients with RAAAs. The VSGNE has the opportunity to first apply the risk tool from this development data set on a separate VSGNE data set to confirm internal validity and permit fine-tuning before application to external data sets. Derivation and validation of a practical risk score for prediction of mortality after open repair of ruptured abdominal aortic aneurysms in a U.S. regional cohort and comparison to existing scoring systemsJournal of Vascular SurgeryVol. 57Issue 2PreviewScoring systems for predicting mortality after repair of ruptured abdominal aortic aneurysms (RAAAs) have not been developed or tested in a United States population and may not be accurate in the endovascular era. Using prospectively collected data from the Vascular Study Group of New England (VSGNE), we developed a practical risk score for in-hospital mortality after open repair of RAAAs and compared its performance to that of the Glasgow aneurysm score, Hardman index, Vancouver score, and Edinburg ruptured aneurysm score. Full-Text PDF Open ArchiveReplyJournal of Vascular SurgeryVol. 58Issue 4PreviewWe thank Tambyraja and colleagues for their thoughtful response to our recent manuscript. Tambyraja and colleagues in Edinburg have extensive experience in this area of study, and they rightly point out that, even after 20 years of research, the prediction of outcome after repair of a ruptured abdominal aortic aneurysm (RAAA) has remained elusive. Full-Text PDF Open Archive