Compensatory Structural and Functional Adaptation after Radical Nephrectomy for Renal Cell Carcinoma According to Preoperative Stage of Chronic Kidney Disease.
OBJECTIVE
We investigated structural hypertrophy and functional hyperfiltration as compensatory adaptations after radical nephrectomy in patients with renal cell carcinoma according to the preoperative chronic kidney disease stage.


METHODS
We retrospectively identified 543 patients who underwent radical nephrectomy for renal cell carcinoma between 1997 and 2012. Patients were classified according to preoperative glomerular filtration rate as no chronic kidney disease--glomerular filtration rate 90 ml/minute/1.73 m(2) or greater (230, 42.4%), chronic kidney disease stage II--glomerular filtration rate 60 to less than 90 ml/minute/1.73 m(2) (227, 41.8%) and chronic kidney disease stage III--glomerular filtration rate 30 to less than 60 ml/minute/1.73 m(2) (86, 15.8%). Computerized tomography performed within 2 months before surgery and 1 year after surgery was used to assess functional renal volume for measuring the degree of hypertrophy of the remnant kidney, and the preoperative and postoperative glomerular filtration rate per unit volume of functional renal volume was used to calculate the degree of hyperfiltration.


RESULTS
Among all patients (mean age 56.0 years) mean preoperative glomerular filtration rate, functional renal volume and glomerular filtration rate/functional renal volume were 83.2 ml/minute/1.73 m(2), 340.6 cm(3) and 0.25 ml/minute/1.73 m(2)/cm(3), respectively. The percent reduction in glomerular filtration rate was statistically significant according to chronic kidney disease stage (no chronic kidney disease 31.2% vs stage II 26.5% vs stage III 12.8%, p <0.001). However, the degree of hypertrophic functional renal volume in the remnant kidney was not statistically significant (no chronic kidney disease 18.5% vs stage II 17.3% vs stage III 16.5%, p=0.250). The change in glomerular filtration rate/functional renal volume was statistically significant (no chronic kidney disease 18.5% vs stage II 20.1% vs stage III 45.9%, p <0.001). Factors that increased glomerular filtration rate/functional renal volume above the mean value were body mass index (p=0.012), diabetes mellitus (p=0.023), hypertension (p=0.015) and chronic kidney disease stage (p <0.001).


CONCLUSIONS
Patients with a lower preoperative glomerular filtration rate had a smaller reduction in postoperative renal function than those with a higher preoperative glomerular filtration rate due to greater degrees of functional hyperfiltration.
Department of Urology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea; Department of Urology, Uijeongbu St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Uijeongbu (BHP), Korea.
Don Kyoung
DK
Choi
Department of Urology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea; Department of Urology, Uijeongbu St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Uijeongbu (BHP), Korea.
Se Bin
SB
Jung
Department of Urology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea; Department of Urology, Uijeongbu St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Uijeongbu (BHP), Korea.
Bong Hee
BH
Park
Department of Urology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea; Department of Urology, Uijeongbu St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Uijeongbu (BHP), Korea.
Byong Chang
BC
Jeong
Department of Urology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea; Department of Urology, Uijeongbu St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Uijeongbu (BHP), Korea.
Seong Il
SI
Seo
Department of Urology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea; Department of Urology, Uijeongbu St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Uijeongbu (BHP), Korea.
Seong Soo
SS
Jeon
Department of Urology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea; Department of Urology, Uijeongbu St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Uijeongbu (BHP), Korea.
Hyun Moo
HM
Lee
Department of Urology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea; Department of Urology, Uijeongbu St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Uijeongbu (BHP), Korea.
Han-Yong
HY
Choi
Department of Urology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea; Department of Urology, Uijeongbu St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Uijeongbu (BHP), Korea. Electronic address: hwanggyun.jeon@samsung.com.
Hwang Gyun
HG
Jeon
D000222:Adaptation, Physiological; D002292:Carcinoma, Renal Cell / Q000150:complications* / Q000601:surgery*; D005260:Female; D006801:Humans; D007668:Kidney / Q000033:anatomy & histology* / Q000502:physiology*; D007680:Kidney Neoplasms / Q000150:complications* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009392:Nephrectomy / Q000379:methods; D051436:Renal Insufficiency, Chronic / Q000150:complications*; D012189:Retrospective Studies; D012720:Severity of Illness Index
carcinoma; glomerular filtration rate; hypertrophy; nephrectomy; renal cell