title: Should PCNL patients have a CT in the prone position preoperatively?
abstract: OBJECTIVE
  Lower pole percutaneous nephrostomy is performed frequently for percutaneous nephrolithotomy (PCNL), using a variety of imaging modalities such as fluoroscopic, computed tomography (CT) or ultrasound guidance. This study was performed to estimate the potential risk of colonic injury during lower pole percutaneous nephrostomy for PCNL.
  
  
  METHODS
  We observed the position of the colon relative to the kidney in 134 patients who underwent CT kidney, ureter, bladder (KUB) examinations in the prone position.
  
  
  RESULTS
  We found the prevalence of colon lying posterior to the kidney (i.e. retrorenal) in males to be 13.6% on the right, and 11.9% on the left, whilst in females it was 13.4% on the right and 26.2% on the left.
  
  
  CONCLUSIONS
  Patients at higher risk for retrorenal colon should be considered for preoperative imaging to identify those patients in whom the colon may be situated posterior to the kidney, allowing for appropriate alterations in technique to be made, such as the use of ultrasound or CT guidance.
authors.affiliation: Department of Urology, NHS Lanarkshire, United Kingdom.
authors.forename: Venu
authors.initials: V
authors.lastname: Chalasani
authors.forename: Darren
authors.initials: D
authors.lastname: Bissoon
authors.forename: Ashok K
authors.initials: AK
authors.lastname: Bhuvanagir
authors.forename: Adrian
authors.initials: A
authors.lastname: Mizzi
authors.forename: Ian B
authors.initials: IB
authors.lastname: Dunn
mesh_terms: D000328:Adult; D000368:Aged; D003106:Colon / Q000000981:diagnostic imaging / Q000293:injuries*; D005260:Female; D006801:Humans; D007416:Intestinal Perforation / Q000000981:diagnostic imaging* / Q000209:etiology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009403:Nephrostomy, Percutaneous / Q000009:adverse effects* / Q000379:methods*; D056888:Patient Positioning / Q000379:methods*; D011183:Postoperative Complications; D015995:Prevalence; D016684:Prone Position; D011857:Radiographic Image Interpretation, Computer-Assisted; D018570:Risk Assessment; D012307:Risk Factors; D012737:Sex Factors; D014057:Tomography, X-Ray Computed