title: Factors affecting blood loss during percutaneous nephrolithotomy using balloon dilation in a large contemporary series.
abstract: OBJECTIVE
  Renal hemorrhage is a common and worrisome complication of percutaneous nephrolithotomy (PNL). We review factors affecting blood loss and transfusion requirements in a large contemporary series of patients undergoing PNL utilizing balloon dilation.
  
  
  METHODS
  We retrospectively reviewed all patients undergoing PNL at one institution from July 2000 to January 2008. Demographics, stone parameters, perioperative factors, complications, and stone-free rates were evaluated. Hemorrhage was estimated using hematocrit and blood transfusion requirement. Various factors were assessed for their association with blood loss using univariate models.
  
  
  RESULTS
  The 225 patients reviewed had a mean stone size of 3.5 +/- 1.8 cm (range, 0.6-9.0 cm), with 54 (23.4%) staghorn and 93 (40.3%) partial staghorn calculi. One hundred and seventy-five (75.8%), 173 (74.9%), and 80 (34.6%) had pelvic, lower pole, and upper pole calculi, respectively. Multiple access tracts were used in 12 (5.2%) patients, with overall stone-free and complication rates of 80.4% and 14.1%. Complications included postoperative fever in 15 patients (6.4%), clinically insignificant pleural effusion in 8 patients (3.4%), 2 (0.8%) renal artery pseudoaneurysms requiring angioembolization, and 1 (0.4%) urinoma requiring stent placement. Mean hematocrit decrease was 6.1 +/- 4.3%, with three (1.3%) patients receiving blood transfusions. On univariate analysis no other statistically significant differences were found between hematocrit decrease and stone size or location, presence of partial or complete staghorn calculi, diabetes, or number of access tracts.
  
  
  CONCLUSIONS
  We report a comparable stone-free rate and a lower incidence of blood transfusion among patients undergoing PNL using balloon dilation.
authors.affiliation: Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, USA. tomaszewskijj@upmc.edu
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Tomaszewski
authors.forename: Marc C
authors.initials: MC
authors.lastname: Smaldone
authors.forename: Tina
authors.initials: T
authors.lastname: Schuster
authors.forename: Stephen V
authors.initials: SV
authors.lastname: Jackman
authors.forename: Timothy D
authors.initials: TD
authors.lastname: Averch
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016063:Blood Loss, Surgical; D002404:Catheterization / Q000009:adverse effects*; D003710:Demography; D005260:Female; D006801:Humans; D007669:Kidney Calculi / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009403:Nephrostomy, Percutaneous / Q000009:adverse effects*; D011300:Preoperative Care; D055815:Young Adult