title: Evaluation of renal defect healing, hemostasis, and urinary fistula after laparoscopic partial nephrectomy with oxidized cellulose.
abstract: OBJECTIVE
  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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Division of Urology, Federal University of São Paulo, São Paulo, Brazil.
authors.forename: Luis
authors.initials: L
authors.lastname: Sabino
authors.forename: Cassio
authors.initials: C
authors.lastname: Andreoni
authors.forename: Eliney F
authors.initials: EF
authors.lastname: Faria
authors.forename: Paulo S V S
authors.initials: PS
authors.lastname: Ferreira
authors.forename: Alexandre R
authors.initials: AR
authors.lastname: Paz
authors.forename: Walid
authors.initials: W
authors.lastname: Kalil
authors.forename: Luiz P
authors.initials: LP
authors.lastname: De Figueiredo
authors.forename: Valdemar
authors.initials: V
authors.lastname: Ortiz
mesh_terms: D000818:Animals; D002483:Cellulose, Oxidized; D005260:Female; D005355:Fibrosis; D005549:Foreign-Body Reaction / Q000209:etiology / Q000473:pathology; D006488:Hemostasis, Surgical / Q000009:adverse effects / Q000379:methods*; D006490:Hemostatics; D010535:Laparoscopy / Q000379:methods*; D023421:Models, Animal; D009336:Necrosis; D009392:Nephrectomy / Q000379:methods*; D011183:Postoperative Complications / Q000209:etiology / Q000473:pathology; D034421:Sus scrofa; D014548:Urinary Fistula / Q000473:pathology* / Q000517:prevention & control; D014945:Wound Healing
chemical_list: D002483:Cellulose, Oxidized; D006490:Hemostatics