Is it useful to measure supratentorial ICP in the presence of a posterior fossa lesion? Absence of transtentorial pressure gradients in an animal model

Abstract

Previous studies with animal models of supratentorial ICP elevation have demonstrated a pressure gradient between the supratentorial and the infratentorial compartments. The present study was designed to investigate the possible presence of such a gradient in the case of infratentorial ICP elevation. An inflatable infratentorial balloon catheter was implanted in seven domestic pigs. The infratentorial ICP (ICPi) was measured in the left cerebellar hemisphere, and the supratentorial ICP (ICPs) was measured in the left cerebral hemisphere. The corresponding pulse amplitudes (ICPi-PA, ICPs-PA) were recorded in both compartments, and the cerebral perfusion pressure (CPP) was calculated. ICPi and ICPs values prior to balloon inflation were 4.4 (SD 2.2) and 4.1 (SD 2.3) mm Hg, respectively, and increased to 63.1 (SD 32.6) and 62.3 (SD 28.1) mmHg after balloon inflation. ICPi-PA rose from 3.1 (SD 0.43) to 12.8 (SD 8.0) mmHg, and ICPs-PA rose from 3.2 (SD 0.63) to 13.0 (SD 7.1) mmHg. CPP decreased from 86.1 (SD 12.0) to 55.4 (SD 14.6) mm Hg. The paired difference between ICPi and ICPs values was 0.44 (SD 1.96) mmHg, and the paired difference of ICP amplitudes was 0.03 (SD 1.19) mmHg. All these differences in infratentorial and supratentorial values were statistically not significant. In conclusion, infratentorial ICP elevation in the presented pig model leads to a uniform ICP elevation in the intracranial space without development of a considerable pressure gradient below and above the tentorium. In the low pressure part of the ICP curve, cerebrospinal fluid connects the compartments and contributes to the pressure equilibrium. The early obstruction of the foramen magnum by intruding cerebellar tissue seems to isolate the infratentorial from the spinal compartment. In the high-pressure part of the curve, the upwards cerebellar transtentorial herniation takes over the pressure transfer, and the whole intracranial space can be considered as a single compartment in the pig.

Use of hemoglobin-based oxygen-carrying solution–201 to improve resuscitation parameters and prevent secondary brain injury in a swine model of traumatic brain injury and hemorrhage

“…Second, alternative pathways of CSF absorption in large animals have been described, 6,7,31,32 and these may lead to lower ICP in situations involving brain injury. Baseline supratentorial ICP values in the swine have been reported to be 4.1 Ϯ 2.3 mm Hg, 37 lower than the commonly accepted range in adult humans (5-15 mm Hg). Previous findings from our studies of CCI in swine demonstrate that ICP rarely rises above 10 mm Hg in the postimpact observation period, despite significant brain injury.…”

Intracranial pressure monitoring in posterior fossa lesions—systematic review and meta-analysis

“…Four other studies contained animals in a preclinical experimental setting including a total of 26 pigs and eight dogs [ 2 , 9 , 10 , 14 ]. Of these four studies, three studies investigated mass lesions in the epidural frontal/temporal and basal ganglia region by the injection of autologous blood [ 6 , 9 , 14 ].…”

“…In total, eight studies were included in the systematic review, containing four studies with humans and four studies with primates (Fig. 1) [2,[7][8][9][10][11][12]14]. Data were extracted in standardized data collection forms.…”

“…Four other studies contained animals in a preclinical experimental setting including a total of 26 pigs and eight dogs [2,9,10,14]. Of these four studies, three studies…”

“…Previously, there have been several reports of patients, cadavers, and primates showing significant differences of ICP values depending on the location of mass and ICP monitoring. We therefore aimed to perform a systematic review and meta-analysis of the literature focusing on supraand infratentorial ICP measurements to clarify the issue of intracranial compartments and ICP monitoring in case of infratentorial mass lesions [6][7][8][9][10][11][12][13][14].…”