Chronic kidney disease classification stratifies mortality risk after elective stent graft repair of the thoracic aorta.
OBJECTIVE
Risk factors for perioperative and late mortality after thoracic endovascular aortic repair (TEVAR) remain ill-defined. In this study, we examined the prognostic significance of chronic kidney disease (CKD), a well-known predictor of death after thoracic aorta open repair, employing a stratification based on CKD stages derived from glomerular filtration rate (GFR) values.


METHODS
A prospective database was evaluated for 179 consecutive patients electively submitted to TEVAR between 1999 and 2007. Preoperative GFR was estimated by using the Cockcroft-Gault equation. Patient groups were stratified into four quartiles by baseline serum creatinine (SC) and GFR values, with quartile I being the lowest, and quartile IV the highest, and into the five CKD stages in reverse order (I GFR >or= 90 ml/min/1.73 m(2); II 60-89; III 30-59; IV 15-29; V < 15). Prognostic significance of preoperative GFR values and CKD stages were investigated by means of univariate and multivariate analyses, and the Kaplan-Meier log-rank method.


RESULTS
A primary technical success was achieved in 166 of 179 patients (92.7%), and an initial clinical success in 158 (88.3%). Thirty-day mortality was 5% (nine cases). Paraplegia or paraparesis were observed in 11 (6.1%) patients, and completely resolved in six cases after cerebrospinal fluid drainage. Preoperative GFR quartiles and CKD stages were significant predictors of 30-day mortality (P = .004 and P < .0001 respectively), whereas SC quartiles did not affect the outcome (P = .12). In particular, GFR quartile I (<60 ml/min/1.73 m(2)) was associated with a ten-fold greater risk of perioperative death compared with the other three quartiles (Odds Ratio 11.4, 95% Confidence Interval 2.3-57.0, P = .003). Midterm survival was 88.8% (159 of 179) at a mean follow-up of 35.6 +/- 23.7 months. Actuarial survival at 60 months was 57.8%, 81.1%, 92.3%, and 100% for GFR quartiles I to IV respectively (P < .0001), and 0.0%, 66.7%, 59.2%, 88.6%, and 100% (P < .0001) for CKD stage V to I respectively. At univariate analyses, age (P = .019), preoperative SC quartiles (P = .001), GFR quartiles (P = .0002), and CKD stages (P < .0001) were all predictive of mid-term mortality. At multivariate Cox proportional hazards regression analysis, only CKD stages remained independently associated with the outcome (P = .008).


CONCLUSIONS
GFR is an accurate prognostic predictor in patients submitted to TEVAR. Also, perioperative and midterm mortality directly correlate with the severity of CKD stages, allowing a risk stratification model to be employed both for risk-adjusted preoperative evaluation, and to establish accurate matching criteria for comparative studies.
Marrocco-Trischitta
Massimiliano M
MM
Department of Vascular Surgery, San Raffaele Scientific Institute, Università Vita-Salute, Milan, Italy. max_marrocco@yahoo.com
Melissano
Germano
G
Kahlberg
Andrea
A
Calori
Giliola
G
Setacci
Francesco
F
Chiesa
Roberto
R
D000368:Aged; D001018:Aortic Diseases / Q000150:complications / Q000401:mortality / Q000503:physiopathology / Q000601:surgery*; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects / Q000295:instrumentation* / Q000401:mortality; D002908:Chronic Disease; D003404:Creatinine / Q000097:blood; D019992:Databases as Topic; D017558:Elective Surgical Procedures; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D053208:Kaplan-Meier Estimate; D007674:Kidney Diseases / Q000150:complications* / Q000401:mortality / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D015607:Stents; D013997:Time Factors; D016896:Treatment Outcome
D003404:Creatinine