INCREASED MEDIASTINAL PRESSURE AND DECREASED CARDIAC-OUTPUT DURING LAPAROSCOPIC NISSEN FUNDOPLICATION

Background. Laparoscopic Nissen fundoplication (LNF) is gaining popula rity. Although the hemodynamic effects of the typical pneumoperitoneum have been studied, the additional consequences of the hiatal dissecti on necessary far LNF have not. Methods. Seven female pigs were anesthe tized, intubated, and ventilated with a volume ventilator and hemodyna mic and mechanical pressure monitoring devices were placed. Pressures were recorded every IS minutes for 1 hour after each of four intervent ions: (1) anesthesia induction (2) CO2 pneumoperitoneum (15 mm Hg), (3 ) LNF, and (4) release of pneumoperitoneum (and removal of ports). Res ults. Right atrial, inferior vena caval, mediastinal, pleural, airway, and pulmonary capillary wedge pressures all increased after pneumoper itoneum (p < 0.05). Only mediastinal pressure (8.6 vs 13.7 mm Hg, pneu moperitoneum vs LNF; p < 0.05) and pleural pressure (2.6 vs 3.5 mm Hg, pneumoperitoneum vs LNF; p. < 0.05) showed a further significant incr ease after LNF. in addition, cardiac output fell significantly after L NF (5.9 vs. 4.6 L/min; p < 0.05). Mediastinal pressure and cardiac out put remained significantly altered after the release of pneumoperitone um. Conclusions. Surgical disruption of the esophageal hiatus during L NF causes both increased mediastinal and pleural pressure and a signif icant reduction in cardiac output. These findings uncover a previously unsuspected physiologic determent that may occur during.