UNASSIGNED: 473 Background: The word heminephrectomy originally referred to the removal of half of a kidney with a duplicated collecting system. In the era of partial nephrectomies, heminephrectomy is sometimes used to describe the removal for @entity5 of >30% of the parenchyma of a non-duplicated kidney. We herein propose a new definition of heminephrectomy: excision of the upper or lower pole of the kidney, removing at least 30% of the parenchymal mass, cutting to hilar fat, and transecting the collecting system. METHODS: Our institutional database of robotic and laparoscopic partial nephrectomies was queried for @entity1 who underwent a partial nephrectomy for @entity5 between 2002 and 2011. @entity1 who had a heminephrectomy for obstruction in a duplicated collecting system were excluded. The @entity1 who had a heminephrectomy by our strict definition were compared to the remainder of @entity1 who had a partial nephrectomy. Logistic regression was used to compare outcomes between the two groups. RESULTS: 61 @entity1 met our strict definition of heminephrectomy out of 643 @entity1 who underwent a partial nephrectomy for @entity5 . Heminephrectomy and non-heminephrectomy @entity1 were similar in age, gender, BMI, ASA score, proportion of left- versus right-sided @entity5 , solitary kidney status, preoperative @entity1011 and GFR. (all p>0.1). The @entity5 in the heminephrectomy group were larger (5.1 vs. 2.8 cm, p<0.001) and had a higher R.E.N.A.L nephrometry score (8.5 vs. 6.5, p<0.001). Operative outcomes reflected the high complexity of performing a heminephrectomy. Estimated @entity190 was greater (373 vs. 267 ml, p=0.04), operative time was longer (214 vs. 185 minutes, p<0.001), warm @entity63 time was longer (25 vs. 20 minutes, p=0.002), and the rate of intra-operative complications was greater (11% vs. 4%, p=0.02) in the heminephrectomy group. On multivariable analysis adjusted for age, preoperative GFR, R.E.N.A.L. score, and warm @entity63 time, heminephrectomy was a significant predictor of lower post-operative GFR (p<0.001). CONCLUSIONS: Our strict definition of heminephrectomy performed for @entity5 in a non-duplicated system will allow precise clinical and research communication about heminephrectomy @entity1 and may aid in the prediction of outcomes after partial nephrectomy.

Defining heminephrectomy for XXXX .

@entity1 :: ('9606', 'Species') :: ['Patients', 'patients'] @entity63 :: ('MESH:D007511', 'Disease') :: ['ischemia'] @entity5 :: ('MESH:D009369', 'Disease') :: ['tumor', 'tumors'] @entity190 :: ('MESH:D006473', 'Disease') :: ['blood loss'] @entity1011 :: ('MESH:D003404', 'Chemical') :: ['creatinine']
@entity5 :: (MESH:D009369,Disease) :: ['cancer']
