Biomedical subjects
J H Duff
Publications and source records attributed to J H Duff.
Specialism and generalism in the future of general surgery.
The progressive specialism that has characterized the practice of medicine over the last 100 years has occurred almost entirely in a scientific context. Societal needs and social changes have had little influence. As we near the end of the 20th century the benefits of scientific specialism are being questioned. New historical studies of specialism have shown that factors other than new knowledge are the driving force for the creation of some subspecialties. The process by which a new subspecialty is established requires both a national institute and a certification examination. Certification is intended to identify those with specific knowledge and skill by inclusion, but is being perceived increasingly as a process that works by exclusion. General surgery, one of the few "generalist" disciplines, finds itself at a crossroads. Further subspecialization with certification will fragment and destroy the discipline. There are cogent arguments, based on economics and care-delivery issues, to preserve general surgery. Making this choice will commit general surgeons to accept the concept of scientific generalism and to the development of the specialty of general surgery in a social context.
Margaret Irving Handy: a lady and a doctor.
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Biliary tract reconstruction in liver transplantation.
Refinements in biliary tract reconstruction and the frequent use of cholangiography have produced a marked decline in the number of deaths from biliary complications after liver transplantation. The authors' method of reconstruction differs from those of others in that it employs no stents or T tubes and retains the donor gallbladder, allowing access to the biliary tract for radiologic purposes in the post-transplant period. In a series of 161 consecutive liver transplants, the frequency of biliary complications was 13.6% (15 anastomotic and 7 gallbladder-related). Of three deaths that occurred in patients with biliary complications, one was due to the complication itself. A Roux-en-Y reconstruction with anastomosis to the donor duct was associated with the lowest anastomotic complication rate (2.2%). Upper abdominal surgery before transplantation, especially shunting, was a major risk factor for biliary complications.
Liver transplantation: the University Hospital-Children's Hospital of Western Ontario experience.
Patients who currently benefit the most from liver transplantation are those with end-stage, non-malignant liver disease. Primary biliary cirrhosis and cirrhosis from chronic active hepatitis (hepatitis B negative) have been the most common indications in our experience. Overall survival rates in excess of 70% at 1 year are now common and those patients who live the first year have a very good prospect of long-term survival. Complete rehabilitation occurs in about 80% of survivors. Patients on life support systems before transplantation and those awaiting urgent retransplantation have the highest mortality rates. Modern anesthetic and surgical techniques have made the operation much safer and more straightforward. Biliary tract complications remain common, especially in patients with a history of previous upper abdominal surgery. Cyclosporine has had a major impact, but in the context of its use in combination with other immunosuppressive agents (antilymphocyte globulin, steroids, azathioprine and OKT3).
Multiorgan failure in critically ill patients.
Of 1136 patients admitted consecutively to two medical-surgical intensive care units, 100 were found to have multiorgan failure, defined as failure of more than two organ systems. The average duration of stay in the intensive care units was 13.4 days. The overall death rate was 78% compared with 12.8% for patients without multiorgan failure. The most common initiating illnesses or insults were sepsis, surgery, accidental trauma and cardiogenic shock. Of potential risk factors studied, shock, sepsis, surgery, pre-existing organ disease and age over 65 years were the most common. Although sepsis occurred before or during the course of multiorgan failure in 78 patients, in only 34 was sepsis judged to be the prime insult leading to multiorgan failure. Surgery during the course of multiorgan failure had neither an adverse nor beneficial effect on outcome. The mean number of organ systems failing was 4.36 for survivors and 5.03 for nonsurvivors. The most common systems to fail were central nervous, cardiovascular and respiratory.
Liver transplantation without venous bypass.
Fifty consecutive orthotopic liver transplants were performed without venous bypass in 41 recipients. Seven patients were transplanted twice and one patient received 3 transplants. The average age of the recipients was 37 years. The commonest indications for transplantation were primary biliary cirrhosis and cirrhosis from chronic active hepatitis. Fifty-eight percent of the recipients had undergone previous upper abdominal surgery. During the anhepatic period systolic blood pressure decreased by 21% to an average of 98 mm. of mercury. Cardiac output decreased by 52% to a mean (+/- SEM) of 3.89 +/- 0.21 L/min., and there was a doubling of the systemic vascular resistance. The hemodynamic alterations promptly returned to preclamping levels following hepatic revascularization. The average intraoperative transfusion requirements were 13 units of packed red blood cells, 9.6 units of platelets, 14.5 units of plasma and 6.6 L of crystalloid. Patients with previous surgery and retransplants required an average of 13 and 17 units of packed red blood cells, respectively. There was no deterioration in renal function in the postoperative period and no patient required hemodialysis. The 30 day survival was 87.8%. The 90-day and one-year actuarial survival is 80.5% and 68.8%, respectively. It is concluded that venous bypass is not necessary as a routine in orthotopic liver transplantation.
Blood transfusion requirements and renal function in patients undergoing liver transplantation without venous bypass.
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Sporadic hemorrhagic colitis associated with Escherichia coli, type O157:H7: unusual presentation mimicking ischemic colitis.
Hemorrhagic colitis is a bacterial infection of the colon, associated with a verotoxigenic strain of Escherichia coli, commonly serotype O157:H7. This recently described disease is usually self-limiting. Because fecal cultures are negative for the usual pathogens and the clinicopathologic features closely mimic ischemic colitis, the patient is exposed to the risk of unnecessary surgery. One such situation is described and differentiation between hemorrhagic and ischemic colitis is discussed.
Renal function after nephrectomy for donor organs.
Thirty-three living related kidney donors were investigated at a mean of 5.8 years after donor nephrectomy (range 3-18 years) to detect late adverse effects. They were evaluated for hypertension, the presence of proteinuria and renal dysfunction as assessed by serum creatinine value and creatinine clearance. There was a significant rise in both diastolic blood pressure and serum creatinine levels and a trend towards significance in the decline in creatinine clearance. Eleven individuals had diastolic blood pressure greater than or equal to 90 mmHg but only 1 required treatment. Although the rise in serum creatinine reached significance the mean serum creatinine (104.91 mumol/l) remained within the normal range. Two patients showed a minimal rise in proteinuria. The overall results confirm that kidney donation is safe and indicate that there are no significant late sequelae.
Major operative trauma increases peripheral amino acid release during the steady-state infusion of total parenteral nutrition in man.
The effect of major operative trauma on skeletal muscle metabolism was examined in nine patients receiving a constant infusion of calories (1460 kcal/m2/day) and protein (75 gm of amino acids/m2/day) for 5 days before and 4 days after an operation. Compared with the preoperative state, 72 hours after the operation there was a significant rise in arterial levels of glucagon, cortisol, norepinephrine, and inactive triiodothyronine and a drop in concentrations of insulin, active triiodothyronine, and amino acids. Forearm blood flow increased, as well as the efflux from forearm muscle of lactate, taurine, serine, glycine, valine, methionine, isoleucine, leucine, phenylalanine, lysine, arginine, and total amino acid nitrogen (440%). This loss of muscle protein after trauma is associated with increased muscle proteolysis, as measured by increased urinary 3-methylhistidine excretion (83%), and accounts for increased nitrogen loss (54%) from the body. Increased activity of the sympathetic nervous system is manifested by increased levels of epinephrine and norepinephrine, a relative lack of insulin, and increased levels of glucagon. This hormonal milieu plays an important role in the production of hypoaminoacidemia, increased efflux of amino acids and lactate from muscle, and negative nitrogen balance observed in these traumatized patients.
Insulin decreases muscle protein loss after operative trauma in man.
Seventy-two hours after major operative trauma, nine patients receiving a constant infusion of calories (1460 kcal/m2/day) and protein (75 gm of amino acid/m2/day) showed a negative nitrogen balance, increased muscle catabolism, as measured by 3-methylhistidine excretion, increased amino acid efflux from muscle, and decreased circulating levels of insulin. When 5 U of insulin/hr were added to the infusate, arterial insulin levels rose significantly from 39.7 +/- 4.1 microU/ml to approximately the pretrauma levels (74.6 +/- 7.7 microU/ml). Despite this normalization of insulin levels, excretion of nitrogen and 3-methylhistidine and the efflux of amino acids from forearm muscle fell but did not return to pretraumatic levels, suggesting some insulin resistance. Visceral gluconeogenesis from amino acids appeared to decrease, since insulin infusion decreased the efflux of alanine from skeletal muscle with no change in its arterial level. Insulin also significantly reduced the efflux of isoleucine, tyrosine, phenylalanine, glutamine, and total amino acid nitrogen from forearm muscle. These findings, along with the partial reduction in the excretion of 3-methylhistidine and nitrogen, suggest that insulin, in combination with infused calories and protein, decreases the loss of muscle protein after trauma.
A simplified method for metabolic studies in conscious swine.
Reliable short-term blood access in conscious swine was provided by implanting multiple silastic catheters. Catheters were inserted into the aorta, hepatic vein, portal vein, and inferior vena cava through a midline laparotomy incision. Multiple catheters also were placed into the external jugular vein through a separate cervical incision. Catheter patency rates for blood withdrawal on the sixth post-operative day were: arterial 100%, hepatic 91%, portal 86%, inferior vena cava 71%. No animal had major wound or catheter infection on the seventh post-operative day. The methods described allow metabolic studies, including measurements of splanchnic blood flow, to be carried out either acutely or for up to at least 7 days post-operatively.
2,3-Dihydroxybenzoic acid. Effect on mortality rate in a septic rat model.
Neutrophil-derived oxygen-free radicals may play a role in organ dysfunction associated with generalized sepsis. A rat model was used to test the effects of two free radical scavengers, dimethyl sulfoxide (DMSO) and 2,3-dihydroxybenzoic acid (2,3-DHB), on mortality from intra-abdominal sepsis produced by cecal ligation and perforation. Being an iron-chelating agent, 2,3-DHB may have an additional bacteriostatic effect. Therapeutic regimens included no treatment; gentamicin sulfate (2 mg given intraperitoneally [IP] every eight hours); DMSO (2 g/24 hr given IP every eight hours in divided doses); 2,3-DHB (35 mg/kg given IP every eight hours); and combinations of gentamicin with each free radical scavenger. No statistically significant improvement in survival was obtained by therapeutic intervention with gentamicin alone, DMSO alone, 2,3-DHB alone, or gentamicin in combination with DMSO. When used in combination with gentamicin, 2,3-DHB yielded a statistically significant improvement in survival when compared with gentamicin alone or with no treatment. These results show that 2,3-DHB when used in combination with gentamicin has a beneficial effect on mortality following intra-abdominal sepsis in this model.
Esophagogastrectomy without thoracotomy for carcinoma of the cardia and lower part of the esophagus.
Between 1 October 1979 and 1 September 1983, 34 patients with 25 adenocarcinomas and nine squamous cell carcinomas of the cardia and lower part of the esophagus have been treated with resection of the celiac lymph nodes (metastasis in 83 per cent of the patients), the lesser curvature of the stomach, cardia and total esophagus without thoracotomy. There was transmural spread of the cancer in 88 per cent of the patients. The esophagus was replaced by a tube made from the greater curvature of the stomach, which was brought through the mediastinum and anastomosed to the cervical esophagus. There was a hospital mortality of 2.9 per cent and the median hospital stay was 15 days. Morbidity included seven anastomotic leaks which closed spontaneously, intrathoracic bleeding (one), secretion retention (six), transient hoarseness (12), persistent dysphagia (one) and transient dumping syndrome (four). No patient has complained of aspiration or reflux of gastric juices. Satisfactory long term relief of dysphagia was achieved in 94 per cent of the patients. There have been no recurrences of tumor at the site of the anastomosis. The one year survival rate is 70 per cent and the median survival time is 19 months.
Liver transplantation: the initial experience of a Canadian centre.
At the University Hospital in London, Ont., 19 patients have received 24 liver transplants. The commonest indications for transplantation were primary biliary cirrhosis and cirrhosis from chronic active hepatitis. The first three patients in the series died of infectious complications. Eleven of the subsequent 16 recipients are alive from 5 months to 2 1/2 years after transplantation. Eight patients who are alive more than 1 year after the operation have an excellent quality of life. Cyclosporine and steroids in combination are used for immunosuppression. With current surgical techniques, modern immunosuppression and good patient selection, the restoration of patients with advanced irreversible liver disease to good health by liver transplantation is a realistic goal. Much effort and considerable resources are required to run a liver transplant program.
Experimental low colorectal anastomosis.
The authors evaluated a side-to-end colorectal anastomosis carried out by the abdominoperineal approach, in which opening of the mucosal layer of the colon, and therefore the lumen, is delayed for 4 days. This technique was compared to transabdominal end-to-end anastomosis performed as low as possible, using the circular stapler and hand-sewing with a one-layer technique. Experimental end-to-end stapled and hand-sewn anastomoses were performed randomly in 24 female mongrel dogs. The operating time was similar for each group. Anastomoses were examined for leaks at 7 to 10 days digitally and by roentgenography after barium enema. At sacrifice 14 days after anastomosis, measurements were made of bursting strength and the distance of anastomoses from the anus. The degree of inflammation was evaluated histologically. There were three leaks in the hand-sewn anastomoses and none in the experimental end-to-end stapled anastomoses. The mean bursting strength was similar for all three techniques. The mean distance from the anus was lowest for the experimental anastomoses. Inflammatory changes were least in the end-to-end stapled anastomoses. Two dogs in this group and one in the experimental group were incontinent postoperatively. The experimental anastomosis compares favourably to end-to-end stapled and hand-sewn anastomoses and may have some advantages for low anastomosis in man.
Arterial plasma amino acids during the first week following femoral shaft fracture.
In ten patients with a femoral shaft fracture, arterial plasma amino acids and glucagon, blood glucose, and serum insulin were measured after an overnight fast on the third, fifth, and seventh days following injury. Ten normal subjects were controls. On all days, concentrations of the key glucogenic amino acid, alanine, were the same in both groups, but levels of another glucogenic amino acid, glycine, were significantly less in the fracture patients. Other amino acid changes following injury were maximal at 7 days, with significant elevations of phenylalanine, methionine, tyrosine, ornithine, lysine, arginine, valine, isoleucine, and leucine. Increased levels of insulin, glucose, valine, isoleucine, and leucine on the fifth and seventh days after injury implied insulin resistance. Plasma glucagon was elevated on the third (p less than 0.05) and seventh (p less than 0.01) days after injury, but the concentrations measured are insufficient to explain the impaired carbohydrate tolerance following a fracture.