Transesophageal echocardiographic detection of gas embolism and cardiac valvular dysfunction during Laparoscopic nephrectomy

We used transesophageal echocardiography (TEE) to monitor venous gas embolism, cardiac performance, and the hemodynamic effects of positioning and pneumoperitoneum in 16 healthy kidney donors undergoing laparoscopic nephrectomy. A four-chamber view was used continuously, except at predetermined intervals, when a complete TEE examination for cardiac function was performed. Other clinical variables recorded include systolic, diastolic, and mean arterial blood pressure; heart rate (HR), pulse oximetric saturations; and end-tidal CO2. Baseline valvular incompetence was seen in 13 of the 16 patients when supine and asleep. After positioning for surgery and induction of pneumoperitoneum, TEE revealed valvular incompetence with regurgitation more pronounced from baseline in 15 of the 16 patients. In one patient, during renal vein dissection, gas entered the right atrium from the inferior vena cava, worsening tricuspid regurgitation. Hemodynamic variables and ejection fraction were tested by using repeated-measures analysis of variance for significance (P < 0.05). Pneumoperitoneum increased (P < 0.05) systolic blood pressure (from 102.8 +/- 3.89 to 120.8 +/- 3.88 mm Hg) and HR (from 68.9 +/- 3.19 to 75.6 +/- 2.62). Ejection fraction was unchanged. The high incidence of valvular incompetence indicates that further studies are needed to assess these effects during laparoscopic nephrectomy with cardiac disease. Laparoscopic surgery has gained popularity as a procedure for the removal of donated kidneys. Although the insufflation of gas necessary for this relatively simple approach poses a low risk of venous air embolism, it may increase the risk of changes in valvular competency.