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Biomedical subjects

R L Varco

Publications and source records attributed to R L Varco.

At least 37 records · Page 2Linked to original sources
PubMed1982

Comparisons between jejunoileal and gastric bypass operations for morbid obesity.

At the University of Minnesota, under the supervision of one staff surgeon, both the jejunoileal bypass (JIB) and gastric bypass (GIB) operations have been done for weight reduction in morbidly obese individuals. Over the past 11 years, end-to-end (40 to 4 cm) JIB performed for 727 patients. In addition, antecolic GIB was performed for 364 patients over the past 6 years. This report is based primarily on a comparison of 205 JIB and 106 GIB patients with surgery between July 1975 and July 1979. Adequate weight loss was seen in 75% of each group. The percentage of excess body weight loss was similar for the first year (65% for JIB and 62% for GIB); however, the JIB patients started at 214% of ideal weight and GIB patients at 197% of ideal weight. The operative mortality rate for either operation was well below 1%, and the immediate operative morbidity rate was low and only rarely delayed discharge from the hospital. The long-term complications for JIB were 37.7% arthralgia or arthritis, 7.1% oxalate urolithiasis, 5.6 incisional hernia, and 1.4% liver failure; complications of GIB were 10.2% nausea and/or vomiting, 1.9% reflux esophagitis, and 2.8% anastomotic problems. At 1 year, plasma cholesterol reductions for JIB patients averaged 42% (P less than 0.001), whereas for the GIB patients it ws only 14% (P less than 0.001). At 1 year after operation, 49% of 88 JIB patients showed progression of liver disease on sequential biopsies, with 31% unchanged and 20% improved. In 43 GIB patients, the biopsies showed improvement in 58%, an unchanged status in 30%, and worsening in 12%. The levels of serum glutamic oxaloacetic transaminase and alkaline phosphatase increased after JIB and eventually returned to normal, while GIB patients had only minor fluctuations of liver function tests. Comparable therapeutic weight results occurred with JIB and GIB; however, the GIB was associated with far fewer serious long-term complications and the JIB with a far greater cholesterol lowering. A percentage of the GIB patients showed progression of liver disease at 1 year after bypass.

Body Weight↗
PubMed1981

The production of malignant tumors of the lung and pleura in dogs from intratracheal asbestos instillation and cigarette smoking.

Nine dogs were given early intratracheal instillations of crocidolite asbestos for periods up to three years. The maximum dose totalled 66 mg/kg. In addition, seven of these dogs smoked nine cigarettes per day, five days per week for six years. A malignant pleural and/or peritoneal mesothelioma developed in six of these dogs, and adenocarcinoma of the lung developed in four, one of which had areas of squamous differentiation. The first animal died of a malignant tumor six years after the onset of exposure, and the last animal died eight years after the onset.

Adenocarcinoma↗
PubMed1981

Positive results of jejunoileal bypass surgery: emphasis on lipids with comparison to gastric bypass.

The positive results of jejunoileal bypass are briefly reviewed: significant weight reduction, lowering of blood pressure, mitigation of diabetes, improved physical functions, amelioration of osteoarthritis and thrombophlebitis, and improved self-esteem and socialization. A major benefit of jejunoileal bypass is the marked and permanent plasma cholesterol and triglyceride reductions. At one year plasma cholesterol is reduced 42 percent, with plasma triglyceride lowered 35 percent. In a comparable series of gastric bypass patients one year after operation, the plasma triglyceride lowering was identical at 35 percent; however, the plasma cholesterol reduction was only 14 percent. Although we currently perform mostly gastric bypasses as the primary metabolic operation for morbid obesity, we believe the jejunoileal bypass should not be discarded from the armamentarium of the surgeon committed to the treatment of this malignant disease.

Adolescent↗
PubMed1980

Intraarterial infusion chemotherapy for hepatic carcinoma using a totally implantable infusion pump.

Intraarterial infusion chemotherapy has several theoretical advantage over conventional therapy for the treatment of unresectable malignancies. However, the catheter problems and patient restriction to the hospital associated with its use have resulted in infrequent application and a notable lack of progress in this field of oncology. This paper describes the use of a totally implantable, percutaneously refillable infusion pump in 5 patients with primary or metastatic carcinoma of the liver. The infusion cannulae were placed into the hepatic arteries under direct vision at laparotomy, and the pumps were placed in subcutaneous pockets. Four patients received infusions of 5-fluorodeoxyuridine at rates of 0.2-0.5 mg/kg/day for periods of three to 29 weeks; the pump in the fifth patient was defective and was removed. The implanted pumps were well tolerated in these subjects, who received chemotherapy as outpatients; the only adverse effects noted were related to FUDR toxicity. This implantable infusion pump appears to be a practical means of delivering long-term intraarterial infusion chemotherapy to outpatients.

Antineoplastic Agents↗
PubMed1980

The effect of partial ileal bypass on plasma lipoproteins.

Plasma lipids and lipoprotein cholesterol concentrations were determined before and at 3 months and 1 year after partial ileal surgery in 28 male survivors of first myocardial infarction (eight normolipidemic subjects and eight type II-A, two type II-B, eight type IV and two type V hyperlipoproteinemic subjects). All subjects had marked reductions in plasma total cholesterol (average 45% and 33% in the type V subjects and 37% and 31% in the other 26 subjects at 3 months and 1 year after surgeryyy). Except for the two type V subjects, all had even more marked reductions in low-density lipoprotein (LDL)-cholesterol than in the total plasma cholesterol, averaging 51% at 3 months and 49% at 1 year after surger. There were no significant changes in high-density lipoprotein (HDL)-cholesterol levels. The hypertriglyceridemic subjects had marked reductions in plasma triglycerides and very low density lipoprotein-cholesterol, whereas the normotriglyceridemic subjects (normals and II-A) had slight increases in these two measurements after surgery. Partial ileal bypass tends to normalize elevated plasma lipid and lipoprotein levels and results in a maximal lowering in LDL-cholesterol concentrations without altering the HDL-cholesterol level.

Adult↗
PubMed1980

Combined hypolipidemia of portacaval transposition and ileal resection in the dog.

The effects of portacaval transposition in combination with exclusion of the distal part of the intestine upon the plasma cholesterol and triglyceride levels was studied in dogs. The dogs tolerated distal intestinal resection, portacaval transposition and their combination well; survival and weight maintenance probably being superior to that of dogs having a standard end-to-side portacaval shunt. Plasma triglyceride levels significantly decreased after portacaval transposition and after intestinal resection; an additional and significant lowering of triglyceride levels was observed after a combination of these procedures. Portacaval transposition significantly lowered the plasma cholesterol level of dogs given a normal chow diet but did not protect them from diet-induced hypercholesterolemia. Distal intestinal resection did not significantly lower the plasma cholesterol level of nonhypothyroid, normocholesterolemic dogs fed regular chow but did protect them from dietary hypercholesterolemia. Portacaval transposition plus intestinal resection demonstrated the addition of these effects upon the plasma cholesterol level. The combination of a portal diversion operation and an intestinal exclusion procedure may provide a synergistic approach to lipid reduction.

Animals↗
PubMed1980

Retarding Novikoff tumor growth by altering host rat cholesterol metabolism.

Tumor cells, in vitro, must derive the majority of their required cholesterol from their host milieu. To determine if limiting tumor-available cholesterol results in limited tumor growth in vivo, Holtzman rats were given 10 X 10(6) Novikoff ascites tumor cells subcutaneously. Prior to inoculation, animals received either distal small bowel exclusion or sham operation plus either standard chow or estrone-containing chow (0.0025% or 0.01%) diets. In three separate experiments it was shown that (1) tumor weight was positively correlated with whole plasma cholesterol levels (r = 0.495; P less than 0.05); (2) the lowest tumor weights were correlated with the lowest plasma cholesterol; (3) low density and very low density lipoprotein cholesterol levels were both individually and in combination positively correlated with tumor weight (R2 = 0.828; P less than 0.01); and (4) survival of subcutaneous tumor inoculated animals was significantly greater in those animals shown to have the lowest plasma cholesterol, 27 +/- 1 days versus 29 +/- 1 days; (P less than 0.05). These data support the concept that limiting tumor-available cholesterol by altering host cholesterol metabolism will limit tumor growth.

Animals↗
PubMed1980

Long-term, continuous intravenous heparin administration by an implantable infusion pump in ambulatory patients with recurrent venous thrombosis.

We studied the effect of long-term intravenous heparin infusion, delivered by a self-recycling, totally implantable infusion pump developed in our laboratory, in 21 patients with recurrent thromboembolic disease. Continuous infusions were maintained in these patients from 1 to 36 months, during which pumps were refilled by percutaneous needle injection at 4- to 8-week intervals. We maintained plasma heparin levels between 0.1 and 0.3 U/ml plasma. This regimen prevented thromboembolic phenomena in all except one patient, who apparently is refractory to heparin as well as oral anticoagulant drug therapy. Marked reduction of pain and improvement of mobility were reported by several patients with vena cava ligature syndrome. No spontaneous hemorrhagic complications occurred; however, several episodes of pump site hemorrhage were associated with pump refills. Bone mineral densities measured in eight subjects after 1 year of heparin infusion [1.00 +/- 0.06 (SE) gm/cm] were not significantly (P = 0.5) different from baseline values (0.98 +/- 0.08 gm/cm); however, osteoporosis did occur in one subject. Serum calcium, phosphorus, alkaline phosphatase, cholesterol, and triglycerides also remained unchanged in these subjects. These data suggest that continuous long-term heparin infusion is a viable therapeutic alternative in subjects with refractory thromboembolic disease.

Adult↗
PubMed1979

Increased hepatic cholesterol synthesis in normal rats by cross-circulation with ileal bypassed partners.

Aortic cross-circulation between Holtzman rat littermates was employed to investigate the possible role of a blood-borne factor from the small intestine in the regulation of hepatic cholesterol synthesis. Experimental pairs, consisting of a normal rat and a distal 50% small bowel excluded partner, demonstrated significantly increased combined hepatic cholesterol synthesis when compared to control pairs, consisting of two normal rats, both at 3 and 5 days following parabiosis. This difference was accounted for by increased hepatic cholesterol synthesis in the normal rat in each experimental pair. Neither weight loss nor differences in dietary intake contributed to this effect. Whole blood cholesterol in the common circulation of both experimental and control pairs was lowered; while hepatic cholesterol content was transiently increased, at 3 but not 5 days following parabiosis. Thus, the intestinal bypassed rat stimulates, or releases inhibition of, hepatic cholesterol synthesis in a non-bypassed parabiotic partner. The mechanism for this phenomenon has yet to be defined.

Acetates↗
PubMed1979

Plasma lipoproteins and coronary arteriography in subjects in the program on the surgical control of the hyperlipidemias. Preliminary report.

Coronary arteriographic findings, plasma lipid and lipoprotein levels, and cigarette smoking history are reported for the first 101 male post myocardial infarction survivors who have been entered into the POSCH clinical trial. Estimates of the extent of stenosis in the major coronary arteries were made using 4 models ranging from a simple determination of the number of the 3 major vessels having significant (i.e. 50% or greater stenosis) disease to more complex methods of determining overall extent of disease in 14 major segments of the coronary arteries. Age was shown to be an important factor in the extent of vessel disease. When controlling for age, plasma cholesterol and LDL-cholesterol levels were shown to be related to the extent of disease, especially in Type II hyperlipoproteinemia subjects. Multiple linear regression analysis demonstrated that age and LDL-cholesterol had positive associations and HDL-cholesterol had an inverse association with the coronary artery disease indices. In this comparatively "healthy" subgroup of the overall population of first MI survivors the major CHD risk factors are limited to plasma lipids and cigarette smoking. This preliminary report of 10% of the recruitment objective of the project supports the currently held views of the lipid--atherosclerosis hypothesis regarding the effects of age-total plasma cholesterol, LDL--cholesterol, and HDL--cholesterol on the extent of coronary atherosclerotic plaques, as determined by coronary arteriography.

Adult↗