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Biomedical subjects

J L Cameron

Publications and source records attributed to J L Cameron.

At least 289 records · Page 16Linked to original sources
PubMed1982

Surgical management of unresectable carcinoma of the pancreas.

The benefits palliative surgery for carcinoma of the pancreas were reviewed in over 8,000 patients in the English literature from 1965 to 1980. The results suggest that biliary bypass prolongs survival, relieves the sequelae of extrahepatic biliary obstruction, and improves the quality of survival. Cholecystojejunostomy to a jejunal loop is easily and safely constructed and should be used instead of choledochojejunostomy unless tumor encroaches near the choledochocystic junction. Percutaneous internal biliary drainage can offer an effective alternate form of palliation in the poor-risk operative candidate or in the patient known to have nonresectable disease. Concomitant gastroenterostomy is recommended in all patients undergoing surgery when prolonged survival is expected. The addition of gastroenterostomy does not increase the operative mortality rate in these patients. If gastroenterostomy is not performed, 13% can be expected to develop subsequent duodenal obstruction. Intraoperative chemical splanchniectomy with 50% ethanol is effective in relieving pancreatic cancer-related pain. Surgical intervention, as well as providing diagnosis and feasibility of resection, also offers considerable palliative benefit for the patient with nonresectable pancreatic cancer.

Common Bile Duct↗
PubMed1982

The role of ischemia in acute pancreatitis: studies with an isolated perfused canine pancreas.

Recent clinical studies have suggested that ischemia may be an important factor in the pathogenesis of acute pancreatitis. The effects of ischemia on the pancreas were investigated utilizing the isolated perfused canine pancreas. Six control glands were perfused with autologous blood with an arterial Po2 ranging from 250 to 350 mm Hg. During the 4-hour perfusion period, gross appearance remained normal, weight gain was minimal (7 gm), and mean amylase levels (853 Caraway units [CU]/dl) remained within normal limits (less than or equal to 1,000 CU/dl). Lowering the arterial Po2 (range 30 to 60 mm Hg) in six glands while maintaining the flow at control levels elicited no significant change. Similarly, decreasing the flow (25% of control) with the arterial Po2 at 250 to 350 mm Hg produced no significant change in gross appearance, weight gain, or mean amylase levels. Combining low flow and low arterial Po2 in six glands also elicited no significant change as compared with controls. Four glands were subjected to total ischemia for 1 hour before being perfused. The glands became hyperemic, but mean weight gain (13 gm) and mean amylase levels (740 CU/dl) wee similar to those of controls. In contrast, in six glands subjected to total ischemia for 2 hours gross edema developed during the subsequent 4-hour perfusion. Mean weight gain (52 gm) and mean amylase levels (1,825 CU/dl) were significantly higher than in controls. These experimental data demonstrate that in the isolated perfused canine pancreas severe ischemia can produced significant injury. They therefore support the hypothesis that ischemia can clinically initiate acute pancreatitis.

Acute Disease↗
PubMed1982

Intrahepatic abscess as a complication of long-term percutaneous internal biliary drainage.

One hundred five patients with obstructive jaundice have undergone percutaneous transhepatic internal biliary drainage at the Johns Hopkins Hospital. Many of these patients subsequently underwent corrective or palliative surgery, whereas other died of malignant disease after relatively short periods of catheter decompression, Seven of these patients with percutaneous internal biliary drainage, however, have been followed for over 8 months. Three of these seven patients developed intrahepatic abscesses at a mean of 16 months after catheter placement. Two of the three patients died of sepsis. In two of the patients the abscesses communicated with the biliary tree, in the third it did not. Intrahepatic abscess formation may be a common complication of long-term percutaneous transhepatic internal biliary drainage, and it should be suspected in any patient with fever or signs of sepsis who has been followed with catheter drainage for over 6 months.

Adenoma, Bile Duct↗
PubMed1982

Portal hypertension, hepatic infarction, and liver failure complicating pancreatic islet autotransplantation.

A patient with chronic pancreatitis who underwent subtotal pancreatectomy and pancreatic islet tissue autotransplantation by portal vein embolization developed marked portal hypertension requiring surgical portal systemic decompression. The patient subsequently developed extensive hepatic infarction and died fo liver failure. Postmortem studies showed organizing thromboemboli containing pancreatic acinar and islet tissue in the intrahepatic portal venous radicles and widespread ischemic infarcts with periportal sparing. Factors contributing to hepatic infarction were thrombosis of portal venous radicles, portasystemic shunting, and systemic arterial hypotension. Marked portal hypertension, hepatic infarction, and liver failure are potential complications of pancreatic islet tissue autotransplantation.

Humans↗
PubMed1982

The role of topical antibiotics in "high-risk" biliary surgery.

Controlled studies have demonstrated that systemic prophylactic antibiotics significantly reduce the sepsis rate after biliary tract surgery. Other studies have documented the efficacy of topical antibiotic irrigation in decreasing the incidence of wound infection after a wide variety of procedures. Whether systemic antibiotics or the combination of systemic and topical antibiotics provide any advantage over topical antibiotics alone, however, has not been determined. Therefore, a prospective, randomized study was carried out comparing topical intra-abdominal and wound antibiotic irrigation (neomycin and polymyxin) with topical antibiotic irrigation plus parenteral antibiotics (gentamicin and penicillin) in 54 patients undergoing "high-risk" biliary surgery. All patients underwent either an elective common bile duct exploration or a biliary-enteric anastomosis for obstructive jaundice. Twenty-five patients were randomized to the group receiving only topical antibiotics, and 29 received topical plus systemic antibiotics. The two groups were similar with respect to age, sex, presence of common duct stones, incidence of jaundice, positive bile cultures at surgery, and type of surgery performed. There were three wound infections in each group, and no patient developed an intra-abdominal abscess. Other infectious complications occurred with similar frequency in the two study groups. This study suggests that topical antibiotics provide effective prophylaxis in biliary tract surgery and that broad-spectrum systemic antibiotic therapy is of no additional benefit. Topical antibiotics provide an alternative means of prophylaxis for patients discovered intraoperatively to be at "high risk" for infection.

Administration, Topical↗
PubMed1982

Crohn's disease: are enteroenteral fistulas an indication for surgery?

Currently many physicians consider enteroenteral fistulas an indication for surgery in Crohn's disease. In an attempt to document the natural history of these fistulas, the courses of 64 patients with Crohn's disease complicated by enteroenteral fistulas were reviewed. The fistulas were diagnosed radiologically in 48 patients (75%) and at operation or by examination of the resected specimen in 16 (25%). Twenty-four of the 48 patients whose fistulas were diagnosed radiologically underwent early operation. The remaining 24 initially had nonoperative management and thus provided information about the natural history of enteroenteral fistulas. Ten of these 24 patients had nonoperative treatment for less than 1 year. All required surgery because of intestinal obstruction, enterovesical fistula, or failed response to medical therapy. Fourteen patients were managed nonoperatively for a mean period of 3.5 years (range 1 to 9 years). Eight of these patients eventually required operation, but the remaining six have to date not needed surgery. In two of these patients the fistulas can no longer be demonstrated radiographically. Patients who initially received nonoperative therapy and later required operation did not have any increased mortality or morbidity as compared with those treated with early surgery. Enteroenteral fistulas are frequently associated with and are the result of active inflammatory disease. The fistulas are usually asymptomatic and are by themselves not considered an indication for operation.

Adolescent↗
PubMed1982

Urinary fistulas in Crohn's disease.

Sixteen patients with urinary fistulas complicating Crohn's disease are reported upon. Fifteen of the fistulas were diagnosed by a history of pneumaturia. Roentgenologic procedures used to confirm the diagnosis were of little value. Specific surgical therapy varied with the locality of the fistula but, generally, consisted of division of the fistula, resection of the involved intestine with primary anastomosis and closure of the bladder. Long term follow-up showed excellent results.

Adolescent↗
PubMed1981

Factors affecting mortality in biliary tract surgery.

Fifteen clinical and laboratory parameters in 155 consecutive patients having bile duct surgery over a 3 year period were analyzed in an effort to define the factors associated with a poor outcome and to define the subpopulation of patients at greatest risk. Ten of the 15 parameters evaluated were found to correlate significantly (p < 0.05) with hospital mortality. Five or more risk factors correlated significantly with mortality (p < 0.0001) and with postoperative renal failure, bacteremia and upper gastrointestinal hemorrhage (p < 0.005). This risk-factor analysis has the advantages of providing information rapidly and employing only clinical observations and readily available laboratory tests. Patients with five or more risk factors should be considered for preoperative percutaneous transhepatic decompression.

Adolescent↗
PubMed1981

Pancreatic islet transplantation in dogs. Critical factors in technique.

Total pancreatectomy and intrasplenic autotransplantation of islet tissue was carried out in dogs. The resected pancreas was prepared by the partial islet isolation technique of gland distention, mincing and collagenase digestion. The influence of variations in technique was studied. Using otherwise identical methods, five collagenase lots were compared. Three lots were effective, resulting in successful transplants in 23 of 26 dogs. Two ineffective lots produced no successes in six dogs (p < 0.001). When minced particle size was varied, particles which would pass freely through a 16 gauge needle resulted in no successes in six dogs. With a larger particle size that would pass freely only through a 15 gauge needle, 15 of 15 transplants were successful (p < 0.001). When tissue was minced by hand, 8 of 11 transplants were successful, compared with 15 of 15 when mechanical mincing was used. With variation in collagenase concentration, success occurred in four of six using 300 units of collagenase/ml of minced tissue, in four of six using 600 units and three of six using 1,200 units. It is concluded that minced particle size and collagenase lot are critical variables in this technique of islet transplantation. Mincing method and concentration of collagenase do not appear to be important variables.

Animals↗
PubMed1981

Distal pancreatectomy and islet autotransplantation for chronic pancreatitis.

Eight patients with chronic pancreatitis underwent 95% pancreatectomy and islet autotransplantation. The partially purified islet material was transplanted into the liver at the time of surgery via embolization into the portal vein. Hyperglycemia requiring insulin therapy developed in all patients immediately followed surgery. Six patients subsequently became normoglycemic an average of 28 days following the transplant (range: 8-90 days). Three of these patient have remained normoglycemic on a regular diet nine, 18, and 22 months following transplant. The other three redeveloped hyperglycemia and insulin dependency three, six, and eight months after surgery. Indirect measurement of functioning islet cell mass by intravenous glucose tolerance testing preoperatively was predictive of the outcome of the transplant. All patients developed portal hypertension (14-60 cm H2O) during tissue injection into the portal vein. Portal hypertension persisted in one patient and required treatment with a mesocaval shunt. The patient subsequently died of hepatic necrosis. Postoperative catheterization in four patients, three to 12 months posttransplant, revealed that portal pressure had returned to normal. Clinically, all seven surviving patients were improved following surgery.

Adult↗
PubMed1981

Aspiration pneumonia: treatment with osmotically active agents.

Utilizing the ex vivo perfused ventilated canine pulmonary lobe, we evaluated the effects of three osmotically active agents on pulmonary function after acid aspiration. Control lobes were stable during a 44-hour perfusion with minimal weight gain, stable pulmonary artery and end-inspiratory pressures, and no increase in intrapulmonary shunting. After acid aspiration during a 44-hour perfusion period, massive weight gain occurred (228 gm), pulmonary artery and end-inspiratory pressure increased, and marked intrapulmonary shunting (44%) developed. When mannitol (molecular weight 182) or dextran 40 (molecular weight 40,000) were added to the perfusate of the acid-instilled lobes, no significant modifications of the acid-induced response were seen during the 44-hour perfusion. The administration of albumin (molecular weight 69,000), however, markedly modified the acid-induced response. Weight gain (53 gm) was almost completely eliminated, pulmonary artery and end-inspiratory pressures were stable, and intrapulmonary shunting increased only minimally (10%). It is concluded that despite the permeability change in the capillary-alveolar membrane produced by acid aspiration, albumin is retained within the vascular space and is effective in reducing the injury response.

Airway Resistance↗
PubMed1981

The management of proximal biliary tract tumors.

Although a relatively unusual tumor, carcinoma of the proximal biliary tree merits inclusion in the differential diagnosis of all cases of obstructive jaundice. A confident preoperative diagnosis is possible, in the majority of cases, with percutaneous transhepatic cholangiography. The improved accuracy of diagnosis of the tumor has indicated that the incidence is higher than hitherto suspected. Early diagnosis and careful evaluation and selection of cases both preoperatively and intraoperatively should improve overall resectability rates as well as survival. In the past, the overall results of treatment of bile duct cancer were unsatisfactory, with the majority of patients dead within one year of liver failure and sepsis. Now, however, as well as possible cures, extended periods of effective palliation can be provided by current techniques. Transhepatic Silastic biliary stents and U tubes provide lasting palliation. New techniques in radiotherapy allow delivery of massive doses of radiation locally to the tumor site. The results of the transhepatic intubation procedures with or without curative resection, combined with radiotherapy, are encouraging and merit continued evaluation. Chemotherapy treatment using currently available regimens appears to offer very little benefit to these patients.

Bile Duct Neoplasms↗
PubMed1981

Prospective clinical trial of antibiotics for pulmonary resections.

One hundred and seventy-one patients undergoing pulmonary resection were included in a prospective randomized clinical study evaluating the efficacy of prophylactic antibiotics. Eight-three patients randomly chosen received no parenteral antibiotics and 88 received a short course of cephalothin intravenously. Topical antibiotics were used in the pleural cavity and would of all patients. There were no statistically significant differences between the two groups in terms of days of postoperative fever, number of postoperative septic complications and length of postoperative stay. However, when postoperative infectious complications developed in the antibiotic group, they were often secondary to gram-negative organisms resistant to cephalothin.

Administration, Topical↗
PubMed1981

Thrombosis of the portal vein following splenectomy for myeloid metaplasia.

The records of 28 patients undergoing splenectomy for myeloid metaplasia were reviewed. Portal and mesenteric venous thrombosis was proved or suspected in five patients. The time interval between splenectomy and portal and mesenteric venous thrombosis varied from six days to three years. The incidental postmortem finding of portal vein thrombosis in one patient suggests that the incidence may be greater than clinically appreciated and may, at times, be asymptomatic. Postsplenectomy thrombocytosis was not found to be a significant risk factor, occurring in only one of the five patients in whom portal vein thrombosis developed. Recommendations for prevention include ligation of the splenic vein close to its junction with the inferior mesenteric vein at the time of splenectomy. In addition, prophylactic anticoagulation therapy or the use of antiplatelet drug therapy postoperatively, or both, should be considered.

Adult↗
PubMed1981

Pulmonary injury caused by free fatty acid: evaluation of steroid and albumin therapy.

Intrapulmonary free fatty acid (FFA) release has been suggested as a pathogenetic mechanism in respiratory failure caused by acute pancreatitis and fat embolism. Utilizing the isolated perfused ventilated canine pulmonary lobe, we evaluated the effects of FFA infusion and its subsequent modification by albumin and steroid therapy. In control lobes perfused for a 4-hour period, there was minimal weight gain (11 gm), intrapulmonary shunting did not occur, and compliance remained within normal limits. When 1 ml of oleic acid was infused into the pulmonary artery lobe weight tripled (188 gm), intrapulmonary shunting (20%) developed, and compliance was significantly decreased compared to controls. When 30 gm of human salt-poor albumin was added to the perfusate immediately after FFA infusion, the lobe response was similar to that of untreated oleic acid lobes. In contrast, when 400 mg of methylprednisolone succinate was added to the perfusate immediately after FFA infusion, lobe weight gain was significantly reduced (94 gm) compared to oleic acid lobes, intrapulmonary shunting did not occur, and compliance was within normal limits. This study suggests that steroids may be of benefit in the treatment of respiratory insufficiency secondary to acute pancreatitis and fat embolism.

Airway Resistance↗