Clinical investigation of the Paraperm EW rigid gas-permeable contact lens.

Paraperm EW is a high oxygen flux silicone/acrylate rigid lens material currently under clinical investigation for extended wear. The purpose of this paper is to report the clinical findings after 12 months of a 2-year investigation of 18 patients fitted with this material. Fifteen were successfully wearing Paraperm EW lenses at 1 year. The only significant clinical finding was keratometric flattening at the 1-month visit. It was concluded that the Paraperm EW lens was durable, comfortable, and provided excellent visual acuity during the course of this investigation without inducing any of the ocular complications sometimes associated with extended wear of hydrogel lenses.

Gastric hypersecretion after formation of small bowel conduits: a common factor in several clinical states.

As a preliminary step in studying the effect on gastric acid secretion in dogs following biliary diversion through isolated intestinal conduits, blind-ended intestinal conduits were constructed and the biliary channel was left undisturbed at this time. The results were surprising in that a significant absolute increase in gastric acid secretion occurred in all dogs, within the range of 65-286%, by merely disconnecting a segment of small bowel from the mainstream of flow of intestinal contents. This effect may be due to the "intestinal phase of gastric secretion hormone" and may in itself provide a partial explanation for the well-documented increase in gastric acid production caused by the Exalto-Mann-Williamson procedure and by choledochoenterostomy utilizing a Roux loop.

Carcinoma of the pancreas and periampullary region.

Over a 21 year period, 245 cases of cancer of the pancreas were operated upon and followed-up at UCLA Hospital. A further 34 cases of periampullary tumor were treated by partial or total pancreatectomy. Apparent clearance of tumors at the time of pancreaticoduodenectomy that was confirmed by subsequent histopathology resulted in a patient survival time of 20.3 months as compared with a figure of 12.9 months when the pathological examination revealed tumor in a resection margin, although the surgeon believed that excision had been complete at the time of operation. Frozen section examination of resection margins is therefore mandatory. The result of performing a pancreaticoduodenectomy in which tumor was seen to be left behind was a survival time of only 6.8 months, which is similar to the survival time of 6.2 months following a palliative biliary bypass. Pancreaticoduodenectomy in patients over the age of 70 resulted in an average survival of only 7.6 months. Of patients having a palliative biliary bypass alone, 13% required subsequent reoperation to bypass distressing duodenal obstruction. A duodenal bypass should therefore be a routine concomitant of a biliary bypass. Total pancreatectomy with duodenectomy for pancreatic cancer gave an increased average survival of 26 months, and it is likely that the frequency of performance of this operation will increase.