Physiologic response to a simplified venovenous perfusion-induced systemic hyperthermia system

Area of Science:

• Cardiovascular Physiology
• Thermoregulation
• Medical Device Engineering

Background:

• Previous venovenous perfusion-induced systemic hyperthermia (vv-PISH) systems were complex and faced dialysis-related issues.
• Lung cancer patients showed improved survival with earlier vv-PISH systems, necessitating simpler, safer alternatives.

Purpose of the Study:

• To evaluate a simplified vv-PISH circuit, excluding a hemodialyzer, for delivering whole-body hyperthermia.
• To investigate the physiological responses to whole-body hyperthermia using the simplified vv-PISH system in a porcine model.

Main Methods:

• A simplified vv-PISH circuit utilizing an Avalon Elite cannula, modified heat exchanger, and centrifugal pump was tested in healthy adult female swine (n=7).
• Therapeutic core temperature (42°C) was achieved and monitored via rectal, bladder, and esophageal probes for homogeneous heat distribution.
• Physiological parameters including heart rate, mean arterial pressure, pulmonary artery pressure, and arterial blood electrolytes were continuously monitored.

Main Results:

• The simplified vv-PISH system successfully achieved a therapeutic core temperature of 42°C in six out of seven swine, with minimal temperature variation (<0.5°C).
• Transient alterations in heart rate and mean arterial pressure were safely managed; pulmonary artery pressure significantly elevated during heating but normalized in most subjects.
• Arterial blood electrolytes remained stable without dialysis, and major organ function stayed within normal limits, indicating the circuit's efficacy and safety.

Conclusions:

• The simplified vv-PISH circuit reliably delivers therapeutic hyperthermia without the need for dialysis.
• This simplified system demonstrates potential for safer and more manageable application in clinical settings, warranting further investigation for cancer therapy.