Armando Rosales-Velderrain, MD, Fernando Dip, MD, Juan Botero, MD, Brian Burnbaum, MD, Emmanuele Lo Menzo, MD, PHD, Samuel Szomstein, MD, Raul Rosenthal, MD. Cleveland Clinic Florida Department of Bariatric and Metabolic Surgery Departmet of Anesthesia.
Introduction: The elevation of intraabdominal presure is seen in diferent clinical situations, beign abdominal trauma and laparoscopic procedures amongst the most common ones. The effect of intraabdominal pressure on intracraneal pressures is well known. The measurement of intracraneal pressure is fundamental, but can be perfomed only using invasive techniques that are not excempt of complications. The direct relationship between the optic nerve sheat and brain enables to obtain a non-invasive evaluation. Our objective was to estimate through ultrasonography the modifications of the optic nerve sheath diameter after establishing pneumoperitoneum during laparoscopic procedures.
Methods and Procedures: All patients that undewent a laparoscopic procedure in supine position between July and August 2013 were included. Non of the patients had history of ocular pathology. Intraabdominal pressure was controlled at 14 mmHg. The optic nerve sheath diameter was measured with a 12 Mhz transducer sagitally 3-mm from its origin at 0, 15, 30 minutes and at the end of the operation.
Results: There were 44 subjects (female: 16, male: 28, 44.22±10.44 yrs and body mass index of 29.45±6.53 m/kg2. The median optic nerve diameter was 48.13±10.01 mm at baseline, 54.68±10.96 mm at 15 min , 59.16±10.45 mm at 30 min and 51.02±11.93 mm after desinflation of pneumoperitoneum. The diameter increased significantly at 15 min by a median of 6 mm (interquartile range (IQR): 3, 8; p<0.0001) and at 30 min by a median of 10 mm (IQR: 7.5, 14; p<0.0001).
Conclusion: Pneumoperitoneum induced elevation of intraabdominal pressure during laparoscopic procedures significantly increased the optic nerve sheath diameter as an indirect sign of elevated intracranial pressure. All changes are immediately reversible without clinical sequelae.