Effects of steep Trendelenburg position and pneumoperitoneum on middleear pressure in patients undergoing robotic radical prostatectomy

Ocular blood flow in steep Trendelenburg positioning during robotic-assisted radical prostatectomy

Purpose:

Several ischemic optic neuropathies that occurred during robotic-assisted laparoscopic radical prostatectomy (RALRP) have been reported to be due to the Trendelenburg position, which lowers ocular perfusion pressure (OPP). We examined changes in pulsatile ocular blood flow (POBF) and its correlation with OPP during RALRP in the steep Trendelenburg position.

Methods:

Pulsatile ocular blood flow and intraocular pressure (IOP) were measured in 50 patients by the OBF Langham System 5 times during RALRP. The mean arterial blood pressure (MAP), heart rate, plateau airway pressure, and end-tidal CO2 (EtCO2) at each time point were recorded. Ocular perfusion pressure was calculated from simultaneous IOP and MAP measurements.

Results:

Pulsatile ocular blood flow was 15.53 ± 3.32 µL/s at T0, 18.99 ± 4.95 µL/s at T1, 10.04 ± 3.24 µL/s at T2, 11.45 ± 3.02 µL/s at T3, and 15.07 ± 3.81 µL/s at T4. Ocular perfusion pressure was 70.15 ± 5.98 mm Hg at T0, 64.21 ± 6.77 mm Hg at T1, 57.71 ± 7.07 mm Hg at T2, 51.73 ± 11.58 mm Hg at T3, and 64.21 ± 12.37 mm Hg at T4. Repeated-measures analysis of variance on POBF and OPP was significant (p>0.05). This difference disappeared when the correlation between MAP and POBF, EtCO2 and POBF, and EtCO2 and OPP were considered, while correlation between MAP and OPP confirmed the difference. The regression analysis between POBF and OPP showed a statistically significant difference at T0 and T3 (r = 0.047, p = 0.031 and r = 0.096, p = 0.002, respectively).

Conclusions:

Pulsatile ocular blood flow and OPP reached the lowest level at the end of surgery.

Robot-assisted radical cystectomy: patient selection and special considerations

Robot-assisted (RA) procedures are increasingly being performed as minimally invasive surgical approaches. Less insensible losses due to a closed abdomen, smaller incisions with less retractor strain, decreased analgesic requirements, and earlier postoperative ambulation are suggested advantages of robot-assisted radical cystectomy (RARC). Patients who undergo open radical cystectomy are also candidates for RARC procedure. However, the steep Trendelenburg position and pneumoperitoneum develop a non-physiological condition. Intra-abdominal adhesions preventing the placement of the ports and patients who cannot tolerate the pneumoperitoneum and/or steep Trendelenburg position are special contraindications of RARC. Besides, body mass index >30 kg/m2, presence of extravesical disease, bulky lymphadenopathy, previous vascular surgery, previous distal colorectal surgery, previous pelvic radiation, previous pelvic trauma, and/or preexisting cardiovascular/pulmonary disease that is compromised with positioning are not certainly contraindicated but unwanted conditions in which the RARC may be performed successfully as the surgeons gain experience.