title: Visceral to total obesity ratio and severe hydronephrosis are independently associated with prolonged pneumoperitoneum operative time in patients undergoing laparoscopic radical nephroureterectomy for upper tract urothelial carcinoma.
abstract: BACKGROUND
  Our aim was to evaluate the effect of visceral obesity and impact of severe hydronephrosis on surgical complexity in patients undergoing laparoscopic radical nephroureterectomy (LRNU).
  
  
  METHODS
  From January 2000 to December 2013, 169 patients underwent radical nephroureterectomy at our institution. We retrospectively reviewed the medical records of 70 patients who underwent LRNU. We measured total fat area (TFA) and visceral fat area (VFA) at the level of the umbilicus using computed tomography. We defined accumulated visceral fat distribution as a VFA/TFA ratio ≥0.45. Ipsilateral hydronephrosis was graded from 0 to 4 by two uro-radiologists blinded to the clinical outcomes.
  
  
  RESULTS
  Among the 70 patients, VFA/TFA ratio was ≥0.45 in 40 patients (57.1%) and 28 (40.0%) had severe hydronephrosis (grade 3 or greater). Patients with a VFA/TFA ratio ≥0.45 had significantly longer pneumoperitoneum and total operation times compared to their counterparts (p = 0.047 and p = 0.002, respectively). Patients with severe hydronephrosis had significantly longer pneumoperitoneum and total operative times compared to their counterparts (p = 0.006 and p = 0.002, respectively). Multivariate logistic regression analysis showed that a high VFA/TFA and severe hydronephrosis were independent predictive factors for prolonged pneumoperitoneum (p = 0.048, HR = 2.90; p = 0.015, HR = 3.82, respectively) and total operative times (p < 0.001, HR = 18.7; p = 0.003, HR = 10.7; respectively). Other pre-clinical factors such as age, gender, BMI, clinical stage, tumor size, location, laterality, degree of perinephric stranding, and surgical procedure did not affect the operation times.
  
  
  CONCLUSIONS
  The present data indicated that the visceral type of adipose accumulation and presence of severe hydronephrosis could provide preoperative information on the degree of technical difficulty associated with LRNU.
authors.affiliation: Department of Urology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582 Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Shigeta
authors.affiliation: Department of Urology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582 Japan.
authors.forename: Eiji
authors.initials: E
authors.lastname: Kikuchi
authors.affiliation: Department of Urology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582 Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Hagiwara
authors.affiliation: Department of Urology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582 Japan.
authors.forename: Seiya
authors.initials: S
authors.lastname: Hattori
authors.affiliation: Department of Urology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582 Japan.
authors.forename: Gou
authors.initials: G
authors.lastname: Kaneko
authors.affiliation: Department of Urology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582 Japan.
authors.forename: Masanori
authors.initials: M
authors.lastname: Hasegawa
authors.affiliation: Department of Urology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582 Japan.
authors.forename: Toshikazu
authors.initials: T
authors.lastname: Takeda
authors.affiliation: Department of Diagnostic Radiology, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Jinzaki
authors.affiliation: Department of Diagnostic Radiology, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Akita
authors.affiliation: Department of Urology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582 Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Miyajima
authors.affiliation: Department of Urology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582 Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Nakagawa
authors.affiliation: Department of Urology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582 Japan.
authors.forename: Mototsugu
authors.initials: M
authors.lastname: Oya
keywords: Laparoscopic radical nephroureterectomy; Severe hydronephrosis; Upper tract urothelial carcinoma; Visceral obesity