title: Prediction and management of a low-lying costal arch which restricts the operative working space during laparoscopic cholecystectomy.
abstract: OBJECTIVE
  Laparoscopic cholecystectomy is difficult to perform in patients with a low-lying costal arch that entirely covers the liver. We conducted this study to clarify the factors related to a low-lying costal arch and establish countermeasures to circumvent this characteristic.
  
  
  METHODS
  The study included 103 consecutive patients who underwent a laparoscopic cholecystectomy. The possible clinical factors associated with a low-lying costal arch restricting the operative working space were analyzed. The position of the liver against the costal arch and the presumed surgical visual angle for laparoscopic cholecystectomy, comprising the hepatic porta, umbilicus, and costal arch, were estimated with abdominal multidetector computed tomography (MDCT).
  
  
  RESULTS
  Seven (7%) patients had a low-lying costal arch presenting an inadequate exposure of Calot's triangle and restricted instrument mobility during laparoscopic cholecystectomy, and three patients required conversion to a laparotomy. A low-lying costal arch was significantly associated with advanced age, shorter stature, lighter body weight, coexisting kyphoscoliosis, gallbladder pathology, laparotomy conversion, and most of all, the liver edge lying above the costal arch and a narrow surgical visual angle upon MDCT. Of the seven patients with a critical low-lying costal arch, four underwent a successful laparoscopic cholecystectomy, this being done by lifting the right costal arch to create a workable surgical field; the rib-lifting procedure was planned as part of the scheduled procedure in the other three patients because the preoperative MDCT examination indicated a poor working space for a laparoscopic cholecystectomy.
  
  
  CONCLUSIONS
  A low-lying costal arch is a substantial risk factor for conversion to a laparotomy when performing a laparoscopic cholecystectomy. However, the operative difficulty related to a low-lying costal arch can be predicted by using preoperative MDCT images and can be managed with proper planning and the appropriate use of the rib-lifting technique.
authors.affiliation: Department of Surgery, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1 Sakamoto, Nagasaki 852-8501, Japan. ytajima@net.nagasaki-u.ac.jp
authors.forename: Yoshitsugu
authors.initials: Y
authors.lastname: Tajima
authors.forename: Tamotsu
authors.initials: T
authors.lastname: Kuroki
authors.forename: Amane
authors.initials: A
authors.lastname: Kitasato
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Adachi
authors.forename: Taiichiro
authors.initials: T
authors.lastname: Kosaka
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Okamoto
authors.forename: Fumihiko
authors.initials: F
authors.lastname: Fujita
authors.forename: Kengo
authors.initials: K
authors.lastname: Kanetaka
authors.forename: Seiya
authors.initials: S
authors.lastname: Susumu
authors.forename: Satoshi
authors.initials: S
authors.lastname: Mochizuki
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Torashima
authors.forename: Takashi
authors.initials: T
authors.lastname: Kanematsu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016009:Chi-Square Distribution; D017081:Cholecystectomy, Laparoscopic / Q000379:methods*; D005260:Female; D006801:Humans; D008099:Liver / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012272:Ribs / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D012307:Risk Factors; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome