COMPARTMENT SYNDROME IN EXPERIMENTAL CHRONIC OBSTRUCTIVE PANCREATITIS- EFFECT OF DECOMPRESSING THE MAIN PANCREATIC DUCT

Chronic pancreatitis is characterized by persistent and severe pain, w hich can be relieved by decompression of the main pancreatic duct (MPD ). Both ductal and interstitial pressures have been shown to be increa sed in chronic pancreatitis in patients. A study was carried out of pa ncreatic interstitial pressure and pancreatic blood flow in normal cat s and those in which chronic obstructive pancreatitis had been induced 5 weeks earlier to determine the effect of decompression of the MPD. In the normal pancreas, median(interquartile range (i.q.r.)) basal int erstitial pressure was 0.05(1.2) mmHg and median(i.q.r.) basal pancrea tic blood flow 58.3(24.3)mmHg per min per 100 g. Secretory stimulation did not change the interstitial pressure significantly, but was assoc iated with a 40 per cent increase in median(i.q.r.) blood flow to 81.8 (45.8)ml per min per 100 g. In contrast, in chronic obstructive pancre atitis, the median(i.q.r.) basal interstitial pressure was 2.0(1.5) mm Hg, which was significantly higher than in the normal gland, and media n(i.q.r.) pancreatic blood flow was 38.3(9.8) ml per min per 100 g, si gnificantly lower than in the normal pancreas. Furthermore, secretory stimulation was associated with a significant increase in median(i.q.r .) interstitial pressure to 3.3(1.6) mmHg and a simultaneous decrease in median(i.q.r.) blood flow to 31.5(13.7)ml per min per 100 g. After decompression of the MPD in cats with chronic obstructive pancreatitis , the median(i.q.r.) basal interstitial pressure was 2.0(1.4) mmHg and on secretory stimulation 1.8(1.5) mmHg. Decompression thus prevented the increase in interstitial pressure seen in the animals,with obstruc tion. In contrast, ductal decompression improved the median(i.q.r.) ba sal pancreatic blood flow to 45.9(38.4) ml per min per 100 g and, furt hermore, this increased significantly on secretory stimulation to a me dian(i.q.r.) of 81.4(47.8)ml per min per 100 g. Decompression thus res tored the normal pattern of secretory hyperaemia. Within the confines of this model, these observations demonstrate that chronic obstructive pancreatitis exhibits a compartment syndrome that is relieved by duct drainage.