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Biomedical subjects

J L Cameron

Publications and source records attributed to J L Cameron.

At least 253 records · Page 14Linked to original sources

The role of resection margin frozen section in the surgical management of Crohn's disease.

The use of frozen section examination of resection margins in selecting the site for an ileocolonic anastomosis was evaluated in patients with Crohn's disease. Seventy-nine patients with ileitis or ileocolitis who underwent first resection with removal of all apparent disease and primary ileocolonic anastomosis were studied. The patients with a resection margin examined by frozen section (FS group, n = 38) and those with margins chosen on the basis of visual inspection alone (NO-FS group, n = 41) were compared. Frozen section examination was found to be poor at detecting margin involvement: although 60 of 61 margins examined by frozen section were reported as negative at the time of operation, 20 of 61 were actually involved by Crohn's disease. Furthermore, despite the use of frozen section examination, the prevalence and severity of margin involvement in the FS and NO-FS groups were not statistically significantly different. Short term and long term clinical outcome were also not statistically different; the incidence of postoperative anastomotic leakage and obstruction was 13 per cent in the FS group and 5 per cent in the NO-FS groups (p NS). Clinical recrudescence rates by life table analysis in the FS and NO-FS groups were 37 +/- 9 per cent and 50 +/- 8 per cent, respectively, at five years, and 60 +/- 12 per cent and 66 +/- 9 per cent at ten years (p NS). Reoperation rates were 18 +/- 8 per cent at five years in both groups and 36 +/- 13 per cent in the FS group and 32 +/- 12 per cent in the NO-FS group at ten years. The findings support conservative resection to achieve grossly uninvolved margins rather than sacrifice of functional intestine in an attempt to achieve histopathologically uninvolved margins on frozen section.

Actuarial Analysis↗

The evaluation of mesoatrial shunt patency with computed tomography.

The mesoatrial shunt is performed in patients with the Budd-Chiari syndrome when the inferior vena cava is occluded and not available for a conventional portosystemic shunt. Computed tomography (CT), with injection of contrast media, was used to evaluate mesoatrial shunt patency with five examinations in four patients. Shunt patency was demonstrated by CT and confirmed by angiography in two studies. Total shunt occlusion diagnosed by CT in two additional cases was confirmed by angiography or operation. Partial graft occlusion diagnosed by CT in a fifth study was verified by both angiography and operation. CT is recommended instead of angiography in the evaluation of mesoatrial shunts because it is less invasive, it may be performed on an outpatient basis, and it yields additional useful information related to shunt patency, such as the volume of ascites, collateral vascularity, and the size of the spleen.

Adult↗

Carcinoma arising in Barrett's esophagus.

Between 1951 and 1983, 32 patients who had adenocarcinoma develop in Barrett's esophagus were identified at our institution. Twenty-nine patients were male (91 per cent) and 29 were white. Amongst the 23 patients in whom the relevant data were available, 78 per cent admitted to regular alcohol intake and 78 per cent smoked. Only one of these patients did not smoke or drink alcohol. Surprisingly, only 61 per cent of the patients had symptoms suggestive of gastroesophageal reflux and reflux was demonstrated roentgenographically in only 41 per cent. Twenty-one of the patients underwent esophagogastrectomy. Life table analysis revealed a survival rate of 34 per cent at two years and 14.8 per cent at five years.

Adenocarcinoma↗

Crohn's disease of the colon. Is there a role for limited resection?

Forty-one patients underwent resection for Crohn's disease of the large bowel. Twelve patients had a total proctocolectomy for diffuse disease of the colon and rectum, and 29 patients with segmental disease of the large bowel underwent limited resection. Thirteen of the 29 patients had a subtotal colectomy, with 7 patients undergoing immediate ileoproctostomy and 6 having an ileostomy. Further surgery was required in 9 f the 13 patients, and long-term enteric continuity was maintained in only 3 patients. Sixteen patients with more localized Crohn's disease of the colon underwent segmental resection. Seven patients required additional surgery, and enteric continuity was restored in 12 of the 16 patients. There was no mortality among these 29 patients. This study suggests that Crohn's disease of the colon may be successfully treated by limited resection when involvement is segmental. In the patient with more extensive disease of the colon with only rectal sparing, morbidity is high and the probability of maintaining enteric continuity is low. Therefore, in these patients total proctocolectomy should be considered.

Adolescent↗

Sclerosing cholangitis. Anatomical distribution of obstructive lesions.

The cholangiograms of 36 patients with sclerosing cholangitis were reviewed. The mean age of the patient group was 43 years, and the mean disease duration was 4.5 years. Seventeen of the patients had associated inflammatory bowel disease. The mean serum bilirubin was 6.8 mg/dl, the mean SGOT was 105 IU/L, the mean SGPT was 108 IU/L, and the mean serum alkaline phosphatase was 534 IU/L. The cholangiograms demonstrated involvement of the extrahepatic bile ducts in 33 patients, involvement of the hepatic duct bifurcation in 33 patients, and involvement of the intrahepatic bile ducts in 35 patients. The cholangiograms were graded as to the areas of the most severe obstructive involvement. In 24 patients the area of most severe involvement was the hepatic duct bifurcation. In eight additional patients the hepatic duct bifurcation, along with the extrahepatic ducts and/or the intrahepatic ducts, were felt to be the areas most severely affected. This predilection for severe obstructive disease at the hepatic duct bifurcation in sclerosing cholangitis held for both patients with and without inflammatory bowel disease. Thus, most patients with sclerosing cholangitis have cholangiographic evidence of diffuse extrahepatic and intrahepatic biliary tract disease, with the hepatic duct bifurcation being the area generally most severely affected.

Adult↗

The role of oxygen-derived free radicals in the pathogenesis of acute pancreatitis.

Acute pancreatitis may be initiated in the ex vivo, perfused canine pancreas preparation by a variety of stimuli. These include oleic acid infusion (FFA), partial duct obstruction with secretin stimulation (POSS), and a 2-hour period of ischemia (ISCH). In each model, pancreatitis is characterized by weight gain, edema, and hyperamylasemia. Oxygen-derived free radicals such as superoxide, hydrogen peroxide, and the hydroxyl radical are highly reactive toxic substances that are normally produced in small amounts during oxidative metabolism. Ordinarily, these substances are detoxified by endogenous intracellular enzymes called free radical scavengers (FRS), such as superoxide dismutase (SOD) and catalase (CAT). These studies were undertaken to evaluate the possible role of oxygen-derived free radicals in the initiation of acute pancreatitis in the isolated canine model. All preparations were perfused for 4 hours with autologous blood. Controls (N = 6): these glands remained normal in appearance, gained minimal weight (6 +/- 1 g), and serum amylase remained normal (less than 1000 u/dl). FFA pancreatitis, FFA alone (N = 6): these glands became edematous, gained weight (113.5 +/- 27.0 g), and developed hyperamylasemia (2087 +/- 387 u/dl). FFA + FRS (N = 6), SOD (50 mg) and CAT (50 mg) were added to the perfusate at time zero: these glands became only minimally edematous, gained less weight (31.8 +/- 10.1 g, p less than 0.05), and amylase remained normal (p less than 0.05). POSS pancreatitis, POSS alone (N = 8): these glands became edematous, gained weight (38.6 +/- 4.6 g), and developed marked hyperamylasemia (9522 +/- 3226 u/dl). POSS + FRS (N = 6): these glands did not develop edema, gained less weight (15.1 +/- 2.6 g, p less than 0.05), and serum amylase only increased to 1815 +/- 343 u/dl, (p less than 0.05). ISCH pancreatitis, ISCH alone (N = 6): these glands became edematous, gained weight (75.8 +/- 25 g), and developed hyperamylasemia (1679 +/- 439 u/dl). ISCH + FRS (N = 6): these glands did not develop edema, gained only 18.3 +/- 9.0 g (p less than 0.005), and serum amylase remained normal (p less than 0.05). These studies demonstrate that, in this canine preparation, acute pancreatitis is significantly ameliorated by oxygen-free radical scavengers. Since this was true whether the pancreatitis was produced by FFA infusion, POSS, or ischemia, it suggests that oxygen-derived free radicals may mediate a common essential step in the pathogenesis of all forms of pancreatitis.

Acute Disease↗

Mesoatrial shunt: a prosthesis modification.

The mesoatrial shunt is the indicated treatment in the Budd-Chiari syndrome when the inferior vena cava is occluded and not usable for the standard portasystemic shunts. As the mesoatrial shunt courses from the abdomen into the right side of the chest, it passes posterior to the xiphoid and sternum and frequently is compressed at this point. A prosthesis modification is reported whereby an exterior silicone rubber cuff is bonded to the Dacron or Gortex graft at the point at which it passes posterior to the sternum. This obviates the possibility of graft compression and should increase long-term patency.

Adult↗

Adenocarcinoma in Barrett's esophagus after elimination of gastroesophageal reflux.

A 56-yr-old man with severe reflux esophagitis, Barrett's esophagus, and a peptic lower esophageal stricture underwent subtotal resection of the Barrett's esophagus with colonic interposition. After the interposition procedure, gastroesophageal reflux was eliminated, as evidenced by absence of clinical and radiographic findings and by the results of a later continuous pH probe recording. Despite the absence of reflux, 8 yr after the colonic interposition the patient was found to have adenocarcinoma in the remnant of the Barrett's esophagus. This case indicates that elimination of gastroesophageal reflux does not necessarily lead to regression of Barrett's mucosa, nor does it prevent development of adenocarcinoma. As a result, patients with Barrett's esophagus should remain under long-term surveillance for dysplasia and adenocarcinoma, even after successful antireflux therapy. If esophagectomy is performed, every attempt should be made to resect all of the esophagus lined by Barrett's mucosa.

Adenocarcinoma↗

Evaluation of the efficacy of Alka-Seltzer Effervescent in gastric acid neutralization.

A commercially available antacid, a mixture of sodium and potassium bicarbonates and citric acid (Alka-Seltzer Effervescent), was evaluated experimentally and clinically for its efficacy in neutralizing 0.1 N HCl and gastric contents. In an in vitro titration study, Alka-Seltzer Effervescent buffered 5-30 times the volume of HCl with a pH between 1.0 and 2.0 to above a pH of 2.5. In an isolated canine pulmonary lobe model, aspiration of the antacid or acid-antacid mixture caused only a mild increase in lobe weight and did not increase intrapulmonary shunting. In the clinical study, when the antacid was given 5-40 min before administration of general anesthesia in a group of patients for emergency surgery, the pH of the gastric contents in each patient was increased to above 4.0. This contrasts with the control group of patients, which showed 50% (P less than 0.05) of the patients were at risk when no antacid was administered. Preoperative administration of Alka-Seltzer effectively increases the pH of the gastric contents in patients undergoing emergency surgery.

Adolescent↗

Management of hemobilia associated with transhepatic internal biliary drainage catheters.

Hemobilia developed as a complication in nine patients with transhepatic biliary drainage catheters. Arteriography revealed pseudoaneurysms of the hepatic artery in five patients and hepatic arterio-portal venous fistulas in three patients. In one patient no arteriographic abnormality was seen. Seven of eight patients were treated successfully with angiographic embolization of the bleeding site. Hemobilia stopped spontaneously in one patient without therapeutic intervention.

Adult↗

Azathioprine and acute pancreatitis: studies with an isolated perfused canine pancreas.

Recent controlled clinical trials have documented the development of acute pancreatitis in 5% of patients receiving azathioprine for Crohn's disease, by far the highest incidence of drug-induced pancreatitis recorded to date. In an effort to evaluate the effects of azathioprine on the pancreas, the isolated ex vivo perfused canine pancreas model was used. No significant changes in gross appearance, weight, or serum amylase occurred in azathioprine-treated glands compared to controls. Azathioprine administration, however, resulted in a significant increase in secretory volume (two fold) and bicarbonate output (two fold), and a profound depression of trypsin output compared to controls. These preliminary studies demonstrate that azathioprine has marked effect on pancreatic function in this model.

Acute Disease↗

Solid and papillary neoplasm of the pancreas. A potentially curable surgical lesion.

Two patients with a recently recognized pancreatic neoplasm are reported. In both cases the tumors occurred in young women (21 and 24 years) who presented with an abdominal mass. Both tumors were large (approximately 12 x 12 cm), one requiring a distal 85% pancreatectomy and the other a total pancreatectomy. Gross pathologic examination revealed apparent encapsulation, cystic degeneration, and hemorrhagic necrosis. Microscopically, the tumors were characterized by distinctive solid and papillary patterns. Such lesions have been reported recently in the pathology literature as "solid and papillary" or "papillary-cystic" neoplasms of the pancreas. Approximately 60 such cases have been reported to date. The histogenesis of these lesions is debatable. They may be diagnosed incorrectly as adenocarcinomas, islet cell tumors, cystadenomas, or cystadenocarcinomas. Assessing the degree of malignancy can be difficult since this tumor is capable of local invasion but usually does not metastasize. There is only one report of a patient dying from distant metastases. Both patients presented here are alive and well seven and 24 months post-surgery. It would appear that despite their large size these pancreatic tumors are potentially curable by surgical resection.

Adult↗

Percutaneous transhepatic management of complex biliary problems.

A series of 27 patients with complex biliary problems secondary to previous biliary operations is presented. The patients are divided into two groups: (1) patients with acute perioperative biliary problems; all had biliary leak with abscess, biliary cutaneous fistula, and/or stricture following cholecystectomy or common duct exploration and (2) patients with chronic postoperative biliary problems; all had previous repair of biliary stricture or injuries with late stricture formation. Early management of all patients included placement of a percutaneous biliary stent. Abscesses were drained operatively, and biliary leaks or fistulas were allowed to close spontaneously. Jaundice and cholangitis were allowed to resolve. Following stabilization, management of stricture, if present, was addressed. Eight acute patients had strictures, of which four were partial and three were dilated percutaneously. Four were complete and required operative repair. All 12 chronic patients had strictures, of which six were partial and successfully managed with percutaneous dilatation. Four patients also had common duct stones which were successfully crushed percutaneously. The authors conclude that percutaneous transhepatic drainage offers significant advantages in the early stabilization and treatment of patients with complex biliary problems, and that partial strictures of the biliary tree may be managed successfully by percutaneous dilatation.

Adolescent↗