Evaluation of Renal Defect Healing, Hemostasis, and Urinary Fistula after Laparoscopic Partial Nephrectomy with Oxidized Cellulose

Abstract

Laparoscopic partial nephrectomy (LPN) has been performed at several institutions using oxidized cellulose (OC) as a means of bleeding and urinary fistula (UF) prevention. However, a foreign-body reaction mimicking either abscess or tumor recurrence has been associated with the use of OC. We evaluated renal-defect healing after LPN with and without OC. Sixteen female Landrace pigs underwent lower-pole excision; all the collecting systems were entered and then closed with absorbable running suture. In group 1, hemostatic U-shaped stitches were the only method of hemostasis. In group 2, a bolster of OC was added to the renal defect. The pigs were sacrificed at 1, 4, 7, or 21 days, and gross findings such as perirenal collection were observed. A catheter was advanced up to the kidney, and methylene blue was injected with collecting system pressure observation; burst pressure was defined as the appearance of extravasation. High risk for UF was defined as burst pressure <10 mm Hg. Neither hemorrhage nor urinoma was observed during sacrifice. One pig from group 2 had a burst pressure of 4 mm Hg At 7 days (high risk for UF). At 21 days in group 2, the tissue was grossly solid, apparently a granuloma. Suppuration tended to be greater in group 2. The foreign-body reaction was more intense in group 2 and was strongly present at 4, 7, and 21 days. The use of OC is associated with higher scores of suppuration and foreign-body reaction. After LPN with OC, postoperative day 7 might be a critical time for the development of urinary leakage.