Evaluation of intra-abdominal pressures and gas embolism during laparoscopic partial nephrectomy in a porcine model

Purpose: Gas embolization is a well documented complication of laparoscopic surgery. We evaluated the association of gas embolization with increased intra-abdominal pressure (LAP) in the porcine model during laparoscopic partial nephrectomy with real-time transesophageal echocardiography. Materials and Methods: Eight domestic pigs weighing 143 to 162 pounds underwent unilateral transperitoneal laparoscopic heminephrectomy with renal artery clamping with varied IAPs. The renal vein was not clamped, allowing the exposure of venous tributaries to the pneumoperitoneum. IAP was increased in 5 mm Hg increments in 4 pigs each by 1) insufflation pressure adjustment to a maximum of 30 mm Hg and 2) intermittent application of an argon beam coagulator (ABC) to the cut kidney surface. Transesophageal echocardiography was used to monitor embolism. Results: None of the 4 animals subjected to increased CO₂ insufflation pressure (maximum 30 mm Hg) demonstrated gas embolization during partial nephrectomy. The ABC caused gas embolization during partial nephrectomy at an IAP of 30 to 50 mm Hg in 4 animals. The volume of embolized gas was 4 to 20 ml. None of the animals showed intraoperative hemodynamic compromise. Conclusions: Gas embolization was not seen during laparoscopic partial nephrectomy with typical insufflation pressures. The ABC can rapidly increase IAP and cause argon embolization at IAPs greater than 30 mm Hg. Prophylactic maneuvers to prevent gas embolization, such as intra-abdominal venting or renal vein clamping, should be considered when applying the ABC.