Patient positioning for subclavian vein catheterization.

The subclavian vein is a commonly used venous access route. Percutaneous cannulation is associated with complications and malpositioning of the catheter. We studied the potential effect of various body positions on subclavian vein catheterization using gross anatomic dissection and magnetic resonance imaging. Findings show that traditional recommendations for patient positioning with the shoulders retracted and the head turned away can act to distort the subclavian vein anatomy and make successful cannulation more difficult. Positioning the patient flat with the head and shoulders in a neutral position is suggested.

Ductus arteriosus aneurysm in infancy.

An infant with symptoms of congestive heart failure at 6 months of age was found by cardiac catheterization at the age of 1 year to have a fusiform aneurysm of the ductus arteriosus as well as discrete stenosis of the left pulmonary artery and a secundum atrial septal defect. The aneurysm was resected, and a pericardial patch angioplasty corrected the peripheral pulmonary stenosis. The atrial septal defect was closed in a separate procedure. To our knowledge, this case is one of four ductal aneurysms reported in infants that have been diagnosed before operation and successfully treated. The pathophysiology and literature are reviewed.

Endothelial seeding of Dacron and polytetrafluoroethylene grafts: the cellular events of healing.

To detect cellular differences in the healing of polytetrafluoroethylene (e-PTFE) and Dacron grafts up to 7 months after implantation, we studied 108 aortic graft interpositions in dogs. Each prosthesis was alternately prepared by endothelial seeding or by an unseeded control method. The grafts were perfusion fixed and studied with light, scanning, and transmission electron microscopy at intervals from before to 221 days after implantation. Seeding resulted in the development of an extensive endothelial flow surface in two out of three of the e-PTFE and none out of four of the Dacron grafts by 10 days after implantation (p = 0.053). After 30 days a microfibrillar subendothelial matrix ranging from 5 to 11 mu formed in all but three grafts with endothelial coverage. The inner capsule of mature Dacron grafts was significantly thicker (169 +/- 143 mu) than in e-PTFE grafts (22 +/- 32 mu; p = 0.002). Seeded and unseeded Dacron grafts had predominantly fibroblasts in the outer capsule of the graft by 10 days. Surface endothelium, vasa vasorum, fibroblasts, and myointimal cells appeared in the inner capsule between 10 and 30 days after implantation. In Dacron grafts, fibroblasts and myointimal cells predominated in the inner capsule at 30 days, with smooth muscle cells not being definitely identifiable until after 150 days. Neither fibroblasts nor myointimal cells were common (present but sparse in one of four e-PTFE grafts) at 30 days, and transmural vasa vasorum were never seen. The seeded endothelial cells migrated rapidly from the sites of initial adhesion near the e-PTFE onto the flow surface. Only one of four of the unseeded e-PTFE grafts had surface endothelium after 30 days, and only moderate coverage developed during 180 days. We conclude that endothelial healing is more rapid in seeded e-PTFE grafts than in seeded Dacron grafts and occurs by a different mechanism.

Specificity of the suppressor cell activity of intestinal lymphocytes.

Experiments were designed to examine the functional characteristics of lymphocytes harvested from the human intestine. Lymphocytes were harvested from the intestines of patients undergoing intestinal resection for a variety of gut disorders. The mitogenic and allogeneic responses of gut lymphocytes were found to be comparable with the response of peripheral blood lymphocytes. Intestinal suppressor cell activity was found to be more specific against other intestinal lymphocytes than peripheral mononuclear cells. The regulation of the intestinal immune response in various bowel disorders may be determined at a local level to a greater degree than had been previously appreciated.

Surgical management of alkaline reflux gastritis.

Fifty-six patients were treated surgically for alkaline reflux gastritis, in each a consequence of subtotal gastrectomy and vagotomy for ulcer disease. Of these, 41 available for follow-up, 18 of whom had had Henley loop jejunal interpositioning and the remaining 23 Roux-en-Y (long-loop) gastroenterostomy. The conditions of most patients improved with respect to reflux symptoms of pain, vomiting, and weight loss, but the patients with Roux-en-Y procedure had uniformly better results that did those with the Henley loop. Although the Henley loops in this series of patients may have been too short to be completely effective in preventing bile reflux into the stomach, we prefer the Roux-en-Y diversion because it is technically easier and safer.

Ultrastructure of gastric myxofibroma with intracytoplasmic collagen.

Electron microscopy of a small mass removed from the stomach of a 65-year-old women demonstrated a myxofibroma composed of a pure population of fibroblasts, many of which contained intracytoplasmic, membrane-bound collagen fibers similar to those found in a few other human tumors and in certain experimental conditions. This ultrastructural documentation supports the hypothesis that pure fibrous neoplasms of the stomach do occur. Electron microscopy of gastric mesenchymal tumors almost always allows for confident differentiation among fibrous, neural, and smooth muscle neoplasms.

Management of lateral duodenal fistulas: a study of fourteen cases.

Fourteen patients with lateral duodenal fistulas were treated over an 8-year period. Fistulas occurred after abdominal trauma (7) or as complications of operations for peptic ulcer (4) and biliary tract disease (3). Six patients with posttraumatic fistulas had had a delay of longer than 24 hours in recognition of the initial duodenal injury. Immediate correction of fluid and electrolyte imbalances, aggressive control of infection with surgical drainage and antibiotics, localization of the fistulous discharge, and early total parenteral nutrition were paramount in treatment. Ten patients had fistulas that persisted despite these measures; they required definitive operation. Surgical treatment consisted largely of diversion and decompression of the involved duodenum (8 patients); duodenorrhaphy reinforced with a jejunal serosal patch and resection of the involved bowel was done once each. Definitive operations performed in the presence of uncontrolled infection and with inadequate duodenal decompression were followed by fistula recurrence (3 patients). There was one fistula-related death (a 7% mortality rate). These results suggest that (1) lateral duodenal fistulas have a low rate of spontaneous closure; (2) when maximal nonoperative management fails, operative diversion and decompression of the duodenum can simplify management and reduce the mortality rate; and (3) definitive therapy is best reserved for situations in which infection is controlled.

Intraoperative choledochoscopy: an efficacious adjunct to common duct exploration in calculous biliary tract disease.

The authors review their experience with 59 consecutive patients undergoing common duct exploration for calculous biliary tract disease, 33 of whom underwent operative choledochoscopy. It is shown that choledochoscopy is not associated with an increase in the amount of time required to perform cholecystectomy and common duct exploration. It is similarly shown that there is no increase in the incidence of postoperative complications occurring in conjunction with the use of the choledochoscope. Because of the safety of the technique and the subjective satisfaction afforded by its use, the authors, now include choledochoscopy as a routine measure in common duct exploration.

Effect of stress and aspirin on extrahepatic portal hypertension in rats.

Extrahepatic portal hypertension was induced in rats by portal venous constriction. Portal pressures on the fourth postconstriction day were significantly elevated in PVC rats when compared to control rats. Splenoportograms showed decreased hepatic flow and venous collaterals. Histologic sections showed gastric mucosal congestion in PVC rats. Gastric acid production and H+ ion equilibration were similar in PVC and control rats. Rats with portal hypertension had a significant increase (p less than 0.001) in mucosal erosions when subjected to a 7-hr restraint stress. Erosion formation was significantly augmented by aspirin administration. Although the exact relationship between the stress of a respiratory infection and variceal bleeding is unknown, these data demonstrate an increased susceptibility of PVC rats to nonhemorrhagic stress. This response is clearly augmented by aspirin treatment. Gastric congestion and the known effect of aspirin on gastric mucosal permeability and the gastric mucosal barrier are implicated in these observations. These findings correlated with clinical observations and strongly suggest avoidance of aspirin therapy in children with extrahepatic portal hypertension.