The effect of nephrotomy on renal function and morphology in dogs.

OBJECTIVE

To determine whether bisection or intersegmental nephrotomy adversely affects glomerular filtration rate (GFR) and whether bisection nephrotomy has less adverse effect than intersegmental nephrotomy.

STUDY DESIGN

Dogs assigned to 5 groups of 3 dogs each, depending on time of euthanasia at postoperative day 1, 4, 8, 15, or 29.

ANIMALS

Fifteen healthy adult intact female dogs.

METHODS

Within 4 days of total and single kidney GFR measurements using technetium Tc 99m-DTPA, left intersegmental nephrotomy and right bisection nephrotomy were performed. The GFR measurements were repeated the day before dogs were killed except for the day 1 group. Histologic examination was performed on kidneys harvested from day 1, 4, 8, and 29 groups. Severity of lesions was scored on a 0 to 4 scale. Single kidney GFR was compared in each kidney before and after nephrotomy. Histologic and GFR changes were compared between bisection and intersegmental nephrotomy kidneys for each time period.

RESULTS AND CONCLUSIONS

Three days after surgery, total GFR was increased from baseline by 176%, with no difference in percent change in single kidney GFR between intersegmental and bisection nephrotomy. By day 7, total and single kidney GFR were not different than baseline. Bisection nephrotomy caused more intrarenal hemorrhage and cortical infarction and inflammation than intersegmental nephrotomy. By 4 weeks, no significant histologic differences were observed between the 2 techniques.

CLINICAL RELEVANCE

Neither intersegmental nor bisection nephrotomy adversely affected GFR. As intersegmental nephrotomy requires additional surgical manipulation and time, bisection nephrotomy is the technique of choice for nephrotomy in dogs.