Int Urol Nephrol (2014) 46:973–977 DOI 10.1007/s11255-013-0618-5
NEPHROLOGY - ORIGINAL PAPER
Acute kidney injury after radical gastrectomy: a single center study Jingping Zhang • Gang Feng • Yanlang Yang Puhong Zhang • Chun Pu • Guohai Zhao
•
Received: 7 October 2013 / Accepted: 25 November 2013 / Published online: 7 December 2013 Ó Springer Science+Business Media Dordrecht 2013
Abstract Objectives To investigate the incidence of acute kidney injury (AKI) and identify risk factors for AKI in patients who undergo radical gastrectomy. Methods This study included 536 patients underwent radical gastrectomy. Primary outcome was AKI, defined as a C50 % increase in serum creatinine relative to baseline during the first three postoperative days. Secondary outcomes were duration of hospitalization and all-cause hospital mortality within 30 days after radical gastrectomy. Results A total of 37 (6.9 %) patients developed postoperative AKI. Age, body mass index (BMI), presence of hypertension, hyperlipidemia, poor blood glucose control, and preoperative higher cystatin C were associated with increased frequency of AKI. By multivariable analyses, the independent risk factors for AKI were age, BMI, hypertension, hyperlipidemia, and preoperative cystatin C. Conclusions Postoperative AKI is not infrequent after radical gastrectomy. Age, BMI, hypertension, hyperlipidemia, and preoperative cystatin C are independently associated with increased risk of postoperative AKI. Keywords Acute kidney injury Radical gastrectomy Risk factor J. Zhang G. Zhao (&) Department of Surgery, Yijishan Hospital of Wannan Medical College, Wuhu 241001, Anhui, China e-mail: [email protected]
Introduction Acute kidney injury (AKI) is defined as the abrupt (e.g., within 48 h) and sustained decrease in renal function. Perioperative AKI is associated with a striking increase in morbidity and mortality among hospitalized patients [1]. The most well studied among all postsurgical AKI is post-cardiac surgery AKI. AKI after cardiac surgery is seen in 5–30 % of patients and 1–5 % of these patients require dialysis after surgery. The mortality in patients with AKI is high as compared to those who do not develop AKI [2–5]. There is little data about AKI after general surgery as compared to AKI after cardiovascular surgery. Kheterpal et al. [6] found incidence of AKI (50 % rise in serum creatinine) was 1 % after general surgery and 0.1 % required dialysis. Radical gastrectomy is a common treatment for gastric cancer. The risk factors for AKI on patient outcomes in the setting of radical gastrectomy are not well understood. Amelioration of renal injury on early stage could offer survival benefit for these patients. Therefore, risk factors for AKI after radical gastrectomy are needed to identify high-risk patients and prevent renal injury on early stage. In this study, we aimed to examine the incidence of AKI and identify risk factors for AKI in patients who undergo radical gastrectomy.
Materials and methods
G. Feng P. Zhang C. Pu Clinical Laboratory, Yijishan Hospital of Wannan Medical College, Wuhu, Anhui, China
Patient population
Y. Yang Department of Nephrology, Yijishan Hospital of Wannan Medical College, Wuhu, Anhui, China
We considered all consecutive patients with localized gastric cancer who underwent radical gastrectomy at Yijishan Hospital of Wannan Medical College between
123
974
January 2011 and September 2013. A total of 536 patients underwent radical gastrectomy during the study period. The study was approved by Yijishan Hospital of Wannan Medical College. Definitions Primary outcome was AKI and was defined as a C50 % increase in serum creatinine (Cr) relative to baseline during the first three postoperative days. We examined a number of variables for their association with AKI, including age, gender, BMI, and blood transfusion during or after operation. We also examined some laboratory variables, including serum Cr, serum blood urea nitrogen (BUN), serum cystatin C, serum triglyceride (TG), serum cholesterol (CHOL), and hemoglobin A1c (HbA1c). Our laboratory ranges for blood variables were as follows: serum Cr [40–130 lmol/L], serum BUN [2.3–7.1 mmol/L], serum cystatin C [0.63–1.25 mg/L], serum TG [0.48–2.30 mmol/ L], serum CHOL [2.30–5.70 mmol/L], and HbA1c [\7.0 %]. Secondary outcomes were duration of hospitalization and all-cause hospital mortality within 30 days after radical gastrectomy. Statistical analyses P values for bivariate relationships between dichotomous variables and continuous variables were two-tailed and derived from t test. Two-tailed P B 0.05 was considered significant. A multivariable logistic model was constructed to predict the occurrence of AKI. Ten variables met these criteria and were forced into a model to predict AKI and then subjected to backward selection (removal of the weakest predictor) until all variables that remained in the model had P B 0.05, adjusted for the other variables that remained in the model. Some variables that were removed late in the selection process were re-inserted into the model to determine whether they were significant, once variables with which they shared some degree of colinearity were removed. All analyses were performed using SAS 9.2 (SAS Institute, Cary, NC).
Results Of 536 patients, 184 were female and 352 were male. The mean age was 58.9 ± 13.8 years. The frequencies of hypertension (SBP C 140 mmHg or DBP C 90 mmHg), hyperlipidemia (TG [ 2.3 mmol/L or CHOL [ 5.7 mmol/L), and poor blood glucose control (HbA1c C 7.0 %) among the patient population were 37.1, 25.0, and 6.3 %, respectively; 28 (5.2 %) patients had all three comorbidities. Thirty-seven (6.9 %) patients had C50 % increase in serum Cr relative to baseline during the first three
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Int Urol Nephrol (2014) 46:973–977
postoperative days (Fig. 1). Three of the 37 patients developed severe AKI that required dialysis. The distributions of risk factors that were associated with AKI are described in Table 1. Gender did not influence the frequency of postoperative AKI. The age in patients with AKI was significantly higher than that in patients without AKI (P = 0.029). The BMI in patients with AKI was also significantly higher than that in patients without AKI (P = 0.043). Hypertension, hyperlipidemia, and poor blood glucose control associated with increased frequency of AKI. Among the laboratory variables of renal function before radical gastrectomy, we could not find the significant difference in BUN and Cr between the group with and without AKI (P = 0.114, P = 0.060); however, cystatin C levels were higher preoperatively in patients who developed postoperative AKI, as compared with those who did not (P = 0.027). By multivariate analyses (Table 2), the independent risk factors for developing AKI included age, BMI, hypertension, hyperlipidemia, and preoperative cystatin C. After radical gastrectomy, 4 patients with AKI and 1 patient without AKI died. In patients with AKI, 3 patients died of multiorgan failure and 1 patient died of bleeding. One patient without AKI patient died of abdominal infection. The overall hospital mortality after radical gastrectomy was low (0.9 %; n = 5). Table 3 showed that duration of hospitalization was significantly greater among patients with AKI as compared with those without AKI (20.7 vs. 11.2 days; P = 0.007).
Discussion Gastric cancer is the fourth most common cancer worldwide but the second leading cause of cancer mortality [7], and it is more common in men and in developing countries. Up to now, surgery has been the most common treatment. For radical gastrectomy, conventional elective gastric resection and perioperative care are associated with a mortality of 0.8–10 % [8] and a postoperative hospital stay of 8–13 days [9]. The high rate of complications leads to prolonged duration of hospital stay and increased costs of hospitalization. AKI may be the consequence or the acute manifestation of a primary kidney disease; in fact, it is by far more frequently complicating other diseases and is thereby known to lead to prolonged length of hospital stay, increased morbidity and mortality, and consecutively generates high medical costs [10]. Lafrance et al. [11] also demonstrate that postsurgical AKI not only lead to increase in shortterm mortality, but it also lead to increase in long-term mortality. The overall mortality after radical gastrectomy was 0.9 % in this study. Although the overall mortality
Int Urol Nephrol (2014) 46:973–977
975
Fig. 1 The preoperative value and maximum postoperative value for serum Cr of patients with AKI Table 1 Risk factors for AKI after radical gastrectomy Risk factor
AKI (n = 37)
No AKI (n = 499)
Gender Female (n = 184)
11
173
Male (n = 352)
26
326
Table 2 Risk factors for AKI: multivariable analysis P value
Risk factor
Odds ratio
95 % confidence interval
P value
0.595
Age (per year increase)
1.81
1.60–1.87
0.042
BMI (per unit increase) Hypertension
1.85
1.78–1.95
0.028
2.37
1.39–3.88
0.012
Hyperlipidemia
2.64
1.21–4.21
0.008
Cystatin C
3.17
1.06–3.88
0.006
Age (year)
73.9
57.8
0.029
BMI
23.2
19.7
0.043
SBP (mmHg)
146
128
0.034
DBP (mmHg)
115
96
0.031
TG (mmol/L)
2.89
1.84
0.025
CHOL (mmol/L)
7.35
3.26
0.019
HbA1c (%) Blood transfusion (ml)
7.4 146
5.2 128
0.038 0.069
6.6
5.9
0.114
116.3
102.5
0.060
Preoperative renal function BUN (mmol/L) Cr (lmol/L) Cystatin C (mg/L)
1.48
0.93
0.027
after radical gastrectomy was low, it should be noted that most of the patients (80 %) who died had developed AKI. In addition, duration of hospitalization was significantly greater in the AKI group compared with those without AKI. Various studies have examined the risk factors associated with AKI after cardiopulmonary bypass. The risk
Table 3 Outcomes measures after radical gastrectomy Outcome
AKI
No AKI
P value
Duration of hospitalization (days) Hospital mortality (within 30 days)
20.7
11.2
0.007
4/37 (10.8 %)
1/499 (0.2 %)
0.000
factors include preoperative deranged renal function, older age, low ejection fraction, presence of congestive heart failure, diabetes, peripheral vascular disease, preoperative use of intra-aortic balloon pump, revision surgery, valvular surgery, chronic obstructive pulmonary disease, and the need of emergency surgery [12–14]. About the risk factors associated with AKI after general surgery, Thakar et al. [15] found that the independent risk factors for AKI after
123
976
gastric bypass surgery were BMI, hyperlipidemia, and preoperative use of ACE-I or ARB. Our study indicates that age, BMI, hypertension, hyperlipidemia, and preoperative cystatin C were independent predictors for AKI after radical gastrectomy by multivariable analysis. We also examined laboratory variables of renal function, including serum Cr, serum BUN, and serum cystatin C before radical gastrectomy. The levels of serum BUN and serum Cr before radical gastrectomy in patients with AKI were higher than in those without AKI, but the difference between two groups did not reach statistical significance (P = 0.114, P = 0.060). These findings may be explained by some facts. First, the study population was relatively small. Second, the levels of serum BUN and serum Cr change significantly according to many dietary factors and the muscle mass of the body. Cystatin C production in the body is a stable process that is not influenced by renal conditions, increased protein catabolism, or dietetic factors. Moreover, it does not change with age or muscle mass like Cr does. Its biochemical characteristics allow free filtration in the renal glomerulus, and subsequent metabolism and reabsorption by the proximal tubule. Therefore, serum cystatin C has been suggested to be an ideal endogenous marker of GFR [16–18]. The preoperative renal insufficiency is probably the most important risk factor for development of AKI. The level of cystatin C could indicate a reliable functional state of the kidney. In our study, the level of preoperative cystatin C was significantly higher in the AKI group compared with those without AKI (P = 0.027). This result is consistent with the study of Wald et al. [19]. Preoperative cystatin C may be an important predictor for development of postsurgical AKI in patients who underwent radical gastrectomy. Before radical gastrectomy, the predictors such as age, BMI, hypertension, hyperlipidemia, and cystatin C could be analysis for screening high-risk patients. Furthermore, avoiding toxic influences, management of underlying diseases, maintaining fluid and electrolyte balance must be strict enough in these patients. There are some limitations to our study. We examined more than 500 patients, which from a single institution. The frequency of AKI was relatively low, which may have limited our ability to test for a large number of risk factors in a multivariable model. The multicentric and large-scale prospective validation studies are required in order to confirm our present findings.
Conclusions Postoperative AKI is not infrequent after radical gastrectomy. Although the overall postoperative mortality is low,
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Int Urol Nephrol (2014) 46:973–977
AKI is associated with increased duration of hospital stay. Age, BMI, hypertension, hyperlipidemia, and preoperative cystatin C were independent predictors for AKI after radical gastrectomy. Our results may lead to strategies for ameliorating perioperative AKI and provide short-term benefits in reducing morbidity and costs of care in patients who undergo radical gastrectomy. Acknowledgments This research was supported by Wannan Medical College (WK2011F26 and YR201112). Conflict of interest of interest.
The authors declare that they have no conflict
References 1. Chertow GM, Burdick E, Honour M et al (2005) Acute kidney injury, mortality, length of stay, and costs in hospitalized patients. J Am Soc Nephrol 16:3365–3370 2. Tuttle K, Worrall N, Dahlstrom L et al (2003) Predictors of ARF after cardiac surgical procedures. Am J Kidney Dis 41:76–83 3. Rosner MH, Okusa MD (2006) Acute kidney injury associated with cardiac surgery. Clin J Am Soc Nephrol 1:19–32 4. Dasta JF, Kane Gill SL, Durtschi AJ et al (2008) Costs and outcomes of acute kidney injury following cardiac surgery. Nephrol Biol Transplant 23:1970–1974 5. Hoste EA, Cruz DN, Davenport A et al (2008) The epidemiology of cardiac surgery associated acute kidney injury. Int J Artif Organs 31:158–165 6. Kheterpal S, Tremper KK, Englesbe MJ et al (2007) Predictors of postoperative renal failure after noncardiac surgery in patients with previously normal renal function. Anesthesiology 107:892–902 7. Price TJ, Shapiro JD, Segelov E et al (2012) Management of advanced gastric cancer. Expert Rev Gastroenterol Hepatol 6:199–208 8. Sasako M, Sano T, Yamamoto S et al (2008) D2 lymphadenectomy alone or with para-aortic nodal dissection for gastric cancer. N Engl J Med 359:453–462 9. Wang D, Kong Y, Zhong B et al (2010) Fast-track surgery improves postoperative recovery in patients with gastric cancer: a randomized comparison with conventional postoperative care. J Gastrointest Surg 14:620–627 10. Obermu¨ller N, Geiger H, Weipert C et al (2013) Current developments in early diagnosis of acute kidney injury. Int Urol Nephrol. doi:10.1007/s11255-013-0448-5 11. Lafrance JP, Miller DR (2010) Acute kidney injury associates with increased long term mortality. J Am Soc Nephrol 21:345–352 12. Lombardi R, Ferreiro A (2008) Risk factors profile for acute kidney injury after cardiac surgery is different according to the level of baseline renal function. Ren Fail 30:155–160 13. Arora P, Rajgopalam S, Ranjan R et al (2008) Preoperative use of angiotensin converting enzyme inhibitors/angiotensin receptor blockers is associated with increased risk of acute kidney injury after cardiovascular surgery. Clin J Am Soc Nephrol 3:1266–1273 14. Karkouti K, Wijeysundera DN, Yau TM et al (2009) Acute kidney injury after cardiac surgery: focus on modifiable risk factors. Circulation 119:495–502 15. Thakar CV, Kharat V, Blank S et al (2007) Acute kidney injury after gastric bypass surgery. Clin J Am Soc Nephrol 2:426–430
Int Urol Nephrol (2014) 46:973–977 16. Knight EL, Verhave JC, Spiegelman D et al (2004) Factors influencing serum cystatin C levels other than renal function and the impact on renal function measurement. Kidney Int 65:1416–1421 17. Ahlstro¨m A, Tallgren M, Peltonen S et al (2004) Evolution and predictive power of serum cystatin C in acute renal failure. Clin Nephrol 62:344–350
977 18. Pei X, Liu Q, He J et al (2012) Are cystatin C-based equations superior to creatinine-based equations for estimating GFR in Chinese elderly population? Int Urol Nephrol 44:1877–1884 19. Wald R, Liangos O, Mary C et al (2010) Plasma cystatin C and acute kidney injury after cardiopulmonary bypass. Clin J Am Soc Nephrol 5:1373–1379
123
NEPHROLOGY - ORIGINAL PAPER
Acute kidney injury after radical gastrectomy: a single center study Jingping Zhang • Gang Feng • Yanlang Yang Puhong Zhang • Chun Pu • Guohai Zhao
•
Received: 7 October 2013 / Accepted: 25 November 2013 / Published online: 7 December 2013 Ó Springer Science+Business Media Dordrecht 2013
Abstract Objectives To investigate the incidence of acute kidney injury (AKI) and identify risk factors for AKI in patients who undergo radical gastrectomy. Methods This study included 536 patients underwent radical gastrectomy. Primary outcome was AKI, defined as a C50 % increase in serum creatinine relative to baseline during the first three postoperative days. Secondary outcomes were duration of hospitalization and all-cause hospital mortality within 30 days after radical gastrectomy. Results A total of 37 (6.9 %) patients developed postoperative AKI. Age, body mass index (BMI), presence of hypertension, hyperlipidemia, poor blood glucose control, and preoperative higher cystatin C were associated with increased frequency of AKI. By multivariable analyses, the independent risk factors for AKI were age, BMI, hypertension, hyperlipidemia, and preoperative cystatin C. Conclusions Postoperative AKI is not infrequent after radical gastrectomy. Age, BMI, hypertension, hyperlipidemia, and preoperative cystatin C are independently associated with increased risk of postoperative AKI. Keywords Acute kidney injury Radical gastrectomy Risk factor J. Zhang G. Zhao (&) Department of Surgery, Yijishan Hospital of Wannan Medical College, Wuhu 241001, Anhui, China e-mail: [email protected]
Introduction Acute kidney injury (AKI) is defined as the abrupt (e.g., within 48 h) and sustained decrease in renal function. Perioperative AKI is associated with a striking increase in morbidity and mortality among hospitalized patients [1]. The most well studied among all postsurgical AKI is post-cardiac surgery AKI. AKI after cardiac surgery is seen in 5–30 % of patients and 1–5 % of these patients require dialysis after surgery. The mortality in patients with AKI is high as compared to those who do not develop AKI [2–5]. There is little data about AKI after general surgery as compared to AKI after cardiovascular surgery. Kheterpal et al. [6] found incidence of AKI (50 % rise in serum creatinine) was 1 % after general surgery and 0.1 % required dialysis. Radical gastrectomy is a common treatment for gastric cancer. The risk factors for AKI on patient outcomes in the setting of radical gastrectomy are not well understood. Amelioration of renal injury on early stage could offer survival benefit for these patients. Therefore, risk factors for AKI after radical gastrectomy are needed to identify high-risk patients and prevent renal injury on early stage. In this study, we aimed to examine the incidence of AKI and identify risk factors for AKI in patients who undergo radical gastrectomy.
Materials and methods
G. Feng P. Zhang C. Pu Clinical Laboratory, Yijishan Hospital of Wannan Medical College, Wuhu, Anhui, China
Patient population
Y. Yang Department of Nephrology, Yijishan Hospital of Wannan Medical College, Wuhu, Anhui, China
We considered all consecutive patients with localized gastric cancer who underwent radical gastrectomy at Yijishan Hospital of Wannan Medical College between
123
974
January 2011 and September 2013. A total of 536 patients underwent radical gastrectomy during the study period. The study was approved by Yijishan Hospital of Wannan Medical College. Definitions Primary outcome was AKI and was defined as a C50 % increase in serum creatinine (Cr) relative to baseline during the first three postoperative days. We examined a number of variables for their association with AKI, including age, gender, BMI, and blood transfusion during or after operation. We also examined some laboratory variables, including serum Cr, serum blood urea nitrogen (BUN), serum cystatin C, serum triglyceride (TG), serum cholesterol (CHOL), and hemoglobin A1c (HbA1c). Our laboratory ranges for blood variables were as follows: serum Cr [40–130 lmol/L], serum BUN [2.3–7.1 mmol/L], serum cystatin C [0.63–1.25 mg/L], serum TG [0.48–2.30 mmol/ L], serum CHOL [2.30–5.70 mmol/L], and HbA1c [\7.0 %]. Secondary outcomes were duration of hospitalization and all-cause hospital mortality within 30 days after radical gastrectomy. Statistical analyses P values for bivariate relationships between dichotomous variables and continuous variables were two-tailed and derived from t test. Two-tailed P B 0.05 was considered significant. A multivariable logistic model was constructed to predict the occurrence of AKI. Ten variables met these criteria and were forced into a model to predict AKI and then subjected to backward selection (removal of the weakest predictor) until all variables that remained in the model had P B 0.05, adjusted for the other variables that remained in the model. Some variables that were removed late in the selection process were re-inserted into the model to determine whether they were significant, once variables with which they shared some degree of colinearity were removed. All analyses were performed using SAS 9.2 (SAS Institute, Cary, NC).
Results Of 536 patients, 184 were female and 352 were male. The mean age was 58.9 ± 13.8 years. The frequencies of hypertension (SBP C 140 mmHg or DBP C 90 mmHg), hyperlipidemia (TG [ 2.3 mmol/L or CHOL [ 5.7 mmol/L), and poor blood glucose control (HbA1c C 7.0 %) among the patient population were 37.1, 25.0, and 6.3 %, respectively; 28 (5.2 %) patients had all three comorbidities. Thirty-seven (6.9 %) patients had C50 % increase in serum Cr relative to baseline during the first three
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Int Urol Nephrol (2014) 46:973–977
postoperative days (Fig. 1). Three of the 37 patients developed severe AKI that required dialysis. The distributions of risk factors that were associated with AKI are described in Table 1. Gender did not influence the frequency of postoperative AKI. The age in patients with AKI was significantly higher than that in patients without AKI (P = 0.029). The BMI in patients with AKI was also significantly higher than that in patients without AKI (P = 0.043). Hypertension, hyperlipidemia, and poor blood glucose control associated with increased frequency of AKI. Among the laboratory variables of renal function before radical gastrectomy, we could not find the significant difference in BUN and Cr between the group with and without AKI (P = 0.114, P = 0.060); however, cystatin C levels were higher preoperatively in patients who developed postoperative AKI, as compared with those who did not (P = 0.027). By multivariate analyses (Table 2), the independent risk factors for developing AKI included age, BMI, hypertension, hyperlipidemia, and preoperative cystatin C. After radical gastrectomy, 4 patients with AKI and 1 patient without AKI died. In patients with AKI, 3 patients died of multiorgan failure and 1 patient died of bleeding. One patient without AKI patient died of abdominal infection. The overall hospital mortality after radical gastrectomy was low (0.9 %; n = 5). Table 3 showed that duration of hospitalization was significantly greater among patients with AKI as compared with those without AKI (20.7 vs. 11.2 days; P = 0.007).
Discussion Gastric cancer is the fourth most common cancer worldwide but the second leading cause of cancer mortality [7], and it is more common in men and in developing countries. Up to now, surgery has been the most common treatment. For radical gastrectomy, conventional elective gastric resection and perioperative care are associated with a mortality of 0.8–10 % [8] and a postoperative hospital stay of 8–13 days [9]. The high rate of complications leads to prolonged duration of hospital stay and increased costs of hospitalization. AKI may be the consequence or the acute manifestation of a primary kidney disease; in fact, it is by far more frequently complicating other diseases and is thereby known to lead to prolonged length of hospital stay, increased morbidity and mortality, and consecutively generates high medical costs [10]. Lafrance et al. [11] also demonstrate that postsurgical AKI not only lead to increase in shortterm mortality, but it also lead to increase in long-term mortality. The overall mortality after radical gastrectomy was 0.9 % in this study. Although the overall mortality
Int Urol Nephrol (2014) 46:973–977
975
Fig. 1 The preoperative value and maximum postoperative value for serum Cr of patients with AKI Table 1 Risk factors for AKI after radical gastrectomy Risk factor
AKI (n = 37)
No AKI (n = 499)
Gender Female (n = 184)
11
173
Male (n = 352)
26
326
Table 2 Risk factors for AKI: multivariable analysis P value
Risk factor
Odds ratio
95 % confidence interval
P value
0.595
Age (per year increase)
1.81
1.60–1.87
0.042
BMI (per unit increase) Hypertension
1.85
1.78–1.95
0.028
2.37
1.39–3.88
0.012
Hyperlipidemia
2.64
1.21–4.21
0.008
Cystatin C
3.17
1.06–3.88
0.006
Age (year)
73.9
57.8
0.029
BMI
23.2
19.7
0.043
SBP (mmHg)
146
128
0.034
DBP (mmHg)
115
96
0.031
TG (mmol/L)
2.89
1.84
0.025
CHOL (mmol/L)
7.35
3.26
0.019
HbA1c (%) Blood transfusion (ml)
7.4 146
5.2 128
0.038 0.069
6.6
5.9
0.114
116.3
102.5
0.060
Preoperative renal function BUN (mmol/L) Cr (lmol/L) Cystatin C (mg/L)
1.48
0.93
0.027
after radical gastrectomy was low, it should be noted that most of the patients (80 %) who died had developed AKI. In addition, duration of hospitalization was significantly greater in the AKI group compared with those without AKI. Various studies have examined the risk factors associated with AKI after cardiopulmonary bypass. The risk
Table 3 Outcomes measures after radical gastrectomy Outcome
AKI
No AKI
P value
Duration of hospitalization (days) Hospital mortality (within 30 days)
20.7
11.2
0.007
4/37 (10.8 %)
1/499 (0.2 %)
0.000
factors include preoperative deranged renal function, older age, low ejection fraction, presence of congestive heart failure, diabetes, peripheral vascular disease, preoperative use of intra-aortic balloon pump, revision surgery, valvular surgery, chronic obstructive pulmonary disease, and the need of emergency surgery [12–14]. About the risk factors associated with AKI after general surgery, Thakar et al. [15] found that the independent risk factors for AKI after
123
976
gastric bypass surgery were BMI, hyperlipidemia, and preoperative use of ACE-I or ARB. Our study indicates that age, BMI, hypertension, hyperlipidemia, and preoperative cystatin C were independent predictors for AKI after radical gastrectomy by multivariable analysis. We also examined laboratory variables of renal function, including serum Cr, serum BUN, and serum cystatin C before radical gastrectomy. The levels of serum BUN and serum Cr before radical gastrectomy in patients with AKI were higher than in those without AKI, but the difference between two groups did not reach statistical significance (P = 0.114, P = 0.060). These findings may be explained by some facts. First, the study population was relatively small. Second, the levels of serum BUN and serum Cr change significantly according to many dietary factors and the muscle mass of the body. Cystatin C production in the body is a stable process that is not influenced by renal conditions, increased protein catabolism, or dietetic factors. Moreover, it does not change with age or muscle mass like Cr does. Its biochemical characteristics allow free filtration in the renal glomerulus, and subsequent metabolism and reabsorption by the proximal tubule. Therefore, serum cystatin C has been suggested to be an ideal endogenous marker of GFR [16–18]. The preoperative renal insufficiency is probably the most important risk factor for development of AKI. The level of cystatin C could indicate a reliable functional state of the kidney. In our study, the level of preoperative cystatin C was significantly higher in the AKI group compared with those without AKI (P = 0.027). This result is consistent with the study of Wald et al. [19]. Preoperative cystatin C may be an important predictor for development of postsurgical AKI in patients who underwent radical gastrectomy. Before radical gastrectomy, the predictors such as age, BMI, hypertension, hyperlipidemia, and cystatin C could be analysis for screening high-risk patients. Furthermore, avoiding toxic influences, management of underlying diseases, maintaining fluid and electrolyte balance must be strict enough in these patients. There are some limitations to our study. We examined more than 500 patients, which from a single institution. The frequency of AKI was relatively low, which may have limited our ability to test for a large number of risk factors in a multivariable model. The multicentric and large-scale prospective validation studies are required in order to confirm our present findings.
Conclusions Postoperative AKI is not infrequent after radical gastrectomy. Although the overall postoperative mortality is low,
123
Int Urol Nephrol (2014) 46:973–977
AKI is associated with increased duration of hospital stay. Age, BMI, hypertension, hyperlipidemia, and preoperative cystatin C were independent predictors for AKI after radical gastrectomy. Our results may lead to strategies for ameliorating perioperative AKI and provide short-term benefits in reducing morbidity and costs of care in patients who undergo radical gastrectomy. Acknowledgments This research was supported by Wannan Medical College (WK2011F26 and YR201112). Conflict of interest of interest.
The authors declare that they have no conflict
References 1. Chertow GM, Burdick E, Honour M et al (2005) Acute kidney injury, mortality, length of stay, and costs in hospitalized patients. J Am Soc Nephrol 16:3365–3370 2. Tuttle K, Worrall N, Dahlstrom L et al (2003) Predictors of ARF after cardiac surgical procedures. Am J Kidney Dis 41:76–83 3. Rosner MH, Okusa MD (2006) Acute kidney injury associated with cardiac surgery. Clin J Am Soc Nephrol 1:19–32 4. Dasta JF, Kane Gill SL, Durtschi AJ et al (2008) Costs and outcomes of acute kidney injury following cardiac surgery. Nephrol Biol Transplant 23:1970–1974 5. Hoste EA, Cruz DN, Davenport A et al (2008) The epidemiology of cardiac surgery associated acute kidney injury. Int J Artif Organs 31:158–165 6. Kheterpal S, Tremper KK, Englesbe MJ et al (2007) Predictors of postoperative renal failure after noncardiac surgery in patients with previously normal renal function. Anesthesiology 107:892–902 7. Price TJ, Shapiro JD, Segelov E et al (2012) Management of advanced gastric cancer. Expert Rev Gastroenterol Hepatol 6:199–208 8. Sasako M, Sano T, Yamamoto S et al (2008) D2 lymphadenectomy alone or with para-aortic nodal dissection for gastric cancer. N Engl J Med 359:453–462 9. Wang D, Kong Y, Zhong B et al (2010) Fast-track surgery improves postoperative recovery in patients with gastric cancer: a randomized comparison with conventional postoperative care. J Gastrointest Surg 14:620–627 10. Obermu¨ller N, Geiger H, Weipert C et al (2013) Current developments in early diagnosis of acute kidney injury. Int Urol Nephrol. doi:10.1007/s11255-013-0448-5 11. Lafrance JP, Miller DR (2010) Acute kidney injury associates with increased long term mortality. J Am Soc Nephrol 21:345–352 12. Lombardi R, Ferreiro A (2008) Risk factors profile for acute kidney injury after cardiac surgery is different according to the level of baseline renal function. Ren Fail 30:155–160 13. Arora P, Rajgopalam S, Ranjan R et al (2008) Preoperative use of angiotensin converting enzyme inhibitors/angiotensin receptor blockers is associated with increased risk of acute kidney injury after cardiovascular surgery. Clin J Am Soc Nephrol 3:1266–1273 14. Karkouti K, Wijeysundera DN, Yau TM et al (2009) Acute kidney injury after cardiac surgery: focus on modifiable risk factors. Circulation 119:495–502 15. Thakar CV, Kharat V, Blank S et al (2007) Acute kidney injury after gastric bypass surgery. Clin J Am Soc Nephrol 2:426–430
Int Urol Nephrol (2014) 46:973–977 16. Knight EL, Verhave JC, Spiegelman D et al (2004) Factors influencing serum cystatin C levels other than renal function and the impact on renal function measurement. Kidney Int 65:1416–1421 17. Ahlstro¨m A, Tallgren M, Peltonen S et al (2004) Evolution and predictive power of serum cystatin C in acute renal failure. Clin Nephrol 62:344–350
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