### Description

Sorbellini et al developed a nomogram for predicting the risk of renal insufficiency following a partial or total nephrectomy. This can help provide informed consent to the patient about one of the serious complications that can occur following surgery. The authors are from Memorial Sloan-Kettering Cancer Center and the Cleveland Clinic Foundation.

Endpoint: probability of renal insufficiency at 7 years after the surgical procedure

Parameters:

(1) age of the patient in years

(2) gender

(3) ASA score

(4) preoperative serum creatinine in mg/dL

(5) percent change in kidney volume as result of the surgery

percent change in renal volume =

= ((volume before surgery) - (volume after surgery)) / (volume before surgery) * 100%

 Parameter Finding Points age of the patient in years < 10 0 10 - 100 (0.3083 * (age)) - 3.0833 > 100 27.75 gender female 0 male 6.2 ASA score I or II 0 III 4.75 IV or V 5.2 percent change in volume (0.0925 * (percent)) + 9.25 preoperative creatinine 0 to 1 mg/dL (61.9 * (creatinine)) 1 to 2 mg/dL (15.1 * (creatinine)) + 46.8 2 to 9 mg/dL see below > 9 mg/dL 100

where:

• The paper refers to ASA scores from 0 to 4. My experience has been with the scale from I to V.

• The range for percent change in renal volume will usually be from 0 to 100%. The nomogram includes points for negative percent change, which would entail hypertrophy of the remaining kidney, if any. Considering that a partial or total nephrectomy is done, this would involve significant hypertrophy.

• Using linear equations for serum creatinine from 0 to 1 and from 1 to 2 mg/dL may not be the most accurate way for point assignment but is the simplest.

points for serum creatinine from 2 to 9 mg/dL =

= (-0.03214 * ((creatinine)^2)) + (3.637 * (creatinine)) + 69.79

total score =

= SUM(points for all 5 parameters)

Interpretation:

• minimum score: 0 (practically 5, since the kidney is unlikely to be larger after surgery)

• maximum score: around 160

• The higher the score the greater the chances of renal insufficiency within 7 years.

 Total Score Probability of Not Having Renal Insufficiency < 92.3 > 0.99 92.3 - 107.5 (-0.005921 * (points)) + 1.5365 107.5 - 116.3 (-0.001794 * ((points)^2)) + (0.3781 * (points)) - 19.02 116.3 - 123.9 (-0.001128 * ((points)^2)) + (0.2172 * (points)) - 9.30 123.9 - 132 (0.003461 * ((points)^2)) - (0.9215 * (points)) + 61.34 > 132 < 0.01