Comparison of Pneumoperitoneum Volumes in Lift Laparoscopy With Variable Lift Locations and Tensile Forces.

OBJECTIVE Evaluate the effect of peritoneal lift location and tensile force on peritoneal volume. STUDY DESIGN Complete randomized block design. ANIMALS Eleven fresh canine cadavers. METHODS Cadavers underwent abdominal computed tomography (CT) scans after each treatment; 1) no lift, 2) umbilical lift with 15% body weight (BW) tension, 3) umbilical lift with 20% BW, 4) umbilical lift with 25% BW, 5) caudal lift with 15% BW, and 6) both umbilical and caudal lift with 15% BW shared equally between devices (dual lift). Isobaric pneumoperitoneal volume, instrument working distances, and transverse measures were calculated and normalized for each dog and compared across treatments. RESULTS Increasing tensile force created a correspondingly larger pneumoperitoneal volume for the umbilical lift (0.34-0.40 total abdominal volume). Dual lifting created a larger pneumoperitoneal volume than either location alone at the same tension (0.39 total abdominal volume). Increasing lift tensions increased working distances, except to caudal abdominal structures. Increasing lift tensions at the umbilical location reduced the transverse diameter of the abdomen at the level of the kidney (0.92-0.86 total abdominal volume) and increased the transverse diameter at the midperitoneum (1.0-1.05 total abdominal volume). CONCLUSIONS Larger isobaric penumoperitoneal volumes are produced with increased tensile force, or with dual lifting at lower force. A caudal lift leads to a small pneumoperitoneal volume but equivalent working space to caudal abdominal structures. Using an umbilical lift with moderate tensile force is preferable, providing good visualization and working space. Caudal lifting may be utilized to access caudal abdominal structures.