Technique and pathophysiology of isolated hypoxic perfusion of the abdomen

Isolated hypoxic perfusion (IHP) is a commonly used technique in the treatm ent of abdominal malignancies. During a phase II-study the pathophysiology of this technique was explored in patients with advanced pancreatic cancer. Twenty perfusions of the abdomen were performed in 17 patients. Under gene ral anesthesia, femoral vessels were dissected and two balloon catheters we re inserted into aorta and vena cava cranial the celiac trunc and the hepat ic veins. After instillation of 40 mg of Mitomycin C (MMC) into the running perfusion system, the perfusion was maintained for further 20 minutes. Blo od samples were taken in 5-minute intervals to determine pH value, blood ga ses as well as concentrations of electrolytes, lactate and MMC in the arter ial blood. Simultanously, blood samples were taken from the perfusion blood via a side-port of the extracorporeal perfusion system. Additionally, perf usion pressures, arterial and central venous pressure, heart rate, and the pressure in the aorta distal the balloon catheter were registered continuou sly. All 20 perfusions had been undertaken without perioperative mortality. After inflating the balloon catheters, blood pressure and heart rate incre ased rapidly. Within 5 minutes of perfusion an increase in pCO(2) and the c oncentrations of K+ and lactate in the perfusate were registered, while pH and pO(2) decreased. Fifteen minutes after instillation of MMC, concentrati ons of MMC in arterial and perfusion blood were equal. Twenty-four hours af ter the perfusion all parameters had returned to normal values. IHP was wel l feasible in 20 consecutive perfusions without major technical problems. A distinct but tolerable combined acidosis resulted from IHP. Despite the ex act positioning and control of the balloon catheters a complete isolation w as not possible.