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Biomedical subjects

B K Gunson

Publications and source records attributed to B K Gunson.

At least 55 records · Page 3Linked to original sources

Factors influencing blood transfusion during adult liver transplantation.

From 1982 to 1990, 300 adults received liver transplants in Birmingham UK with a median intraoperative blood transfusion rate of 23.5 units for the first 50 patients falling to 8 units for the last 50. The major factors in the reduction of blood usage were the experience of the team, the use of venovenous bypass and the use of an argon beam coagulator. Univariate analysis of preoperative factors in an attempt to predict patients at risk of excessive intraoperative transfusion showed that levels of serum sodium, urea, creatinine, haemoglobin, patient weight and the presence of ascites were significantly related to the quantity of blood transfused, although stepwise discriminant analysis showed that only blood urea and platelet count had an independent association with transfusion. The final model was poorly predictive of intraoperative transfusion requirements. Technical factors rather than patient-related factors are more important in the control of intraoperative bleeding in newly established transplant programmes.

Adolescent↗

Long-term immunosuppression after liver transplantation: are steroids necessary?

Steroid therapy was withdrawn in 85% of 152 orthotopic liver transplant recipients with grafts surviving for more than 3 months, and 87% of these remained steroid-free. Steroid therapy was restarted in 8% for reasons other than rejection. The most common was conversion of immunosuppression because of cyclosporine nephrotoxicity. The incidence of rejection after steroid withdrawal was low: 3.8% for chronic rejection (CR) and 4.5% for acute rejection. Only 3 grafts (1.9%) were lost because of CR. No risk factors have been identified for the development of CR after steroid withdrawal, but a protective role for azathioprine has been suggested.

Adolescent↗

Arteries and veins formed within renal vessels: a previously neglected observation.

An abnormality of blood vessels was noted in a biopsy of a renal transplant. This took the form of apparent development of a new artery inside and concentric with the old, with elastic laminae and a muscular media, separated from the old internal elastic lamina by poorly cellular tissue. In a systematic study of material from another 119 renal transplants, 13 nephrectomy specimens for chronic pyelonephritis and hydronephrosis, 28 renal biopsies showing interstitial nephritis, and 18 renal biopsies showing small vessel vasculopathy of accelerated hypertensive type, similar arterial changes were seen in another 10 renal transplants that showed chronic vascular rejection, 1 case of chronic interstitial nephritis, and 3 cases of vasculopathy, 2 with accelerated hypertension and 1 with systemic sclerosis. One renal transplant also showed apparent development of new muscular veins inside old veins. Immunohistological study for smooth muscle actin confirmed that the apparently new arterial and venous structures contained smooth muscle cells. The arterial abnormality may be called arterialisation of intrarenal arteries. This change appears to be not rare, is distinctive, and has scarcely been previously recognised or reported as a response of intrarenal blood vessels to damage.

Adult↗

Primary hepatic malignancy: the role of liver transplantation.

Between January 1982 and April 1989, 134 patients with a suspected liver neoplasm were referred to the liver unit, Queen Elizabeth Hospital, Birmingham. In 105 (78 per cent), a primary hepatic neoplasm was histologically confirmed, and 47 patients (45 per cent) proved to have primary hepatocellular carcinoma. Twenty-nine orthotopic liver transplants were performed in 28 of these patients (27 per cent). Twenty patients (71 per cent) survived 30 days or longer (median 11.5 months; range 2-87 months), of whom nine are currently alive. We retrospectively analysed our data to determine the influence of preoperative evaluation, histological type and staging on outcome. Computed tomography proved to be superior to intraoperative assessment (86 versus 58 per cent) in diagnosing tumour positive nodes. Patients with tumour negative lymphadenopathy had a better prognosis. Postoperative stage I/II had a median survival of 16 months (range 3-87 months) compared with 7.5 months (range 2-20 months) for stage III. Non-cirrhotic patients with hepatocellular carcinoma had the best prognosis; cholangiocellular carcinoma and cirrhotic patients with hepatocelluar carcinoma had the worst outcome with no survivors beyond 1 year. Because of the advanced stage of disease at the time of presentation, the value of liver transplantation in primary liver cancer is limited. For those presenting with advanced disease confined to the liver (stage I/II) in whom conventional hepatic resection is not possible, significant benefit can be achieved in selected cases.

Adenoma, Bile Duct↗

Morphometric correlates of renal excretory function.

There is often thought to be little or no correlation between renal excretory function and histological changes in the kidney, especially in acute renal failure and in the kidney examined post-mortem. We studied the relationship between renal function and structure in 28 patients at necropsy and in 41 patients who had a renal biopsy. A point-counting method was used on kidney stained by an immunoperoxidase method using an antiserum to proximal tubule brush border; an antiserum to Tamm-Horsfall protein, which is a marker of thick limbs of the loop of Henle; and a monoclonal antibody to epithelial membrane antigen, normally a marker of all parts of the tubule except proximal tubule. There was a correlation between the reciprocal of plasma creatinine concentration, which is a measure of renal function, and the ratio of brush border positive tubules to negative tubules. There was also a less strong correlation between renal function and ratios of Tamm-Horsfall positive tubules to negative tubules and of cast-containing tubules to others. There was no correlation between renal function and the ratio of tubules expressing epithelial membrane antigen to those not expressing it. The method of point-counting tubules stained by the brush border antiserum was a useful, practical way of correlating renal function and structure which could be used even on post-mortem kidney.

Adolescent↗

Referral of patients with primary biliary cirrhosis for liver transplantation.

All patients with primary biliary cirrhosis referred to this unit for consideration for transplantation between April 1981 and January 1989 were analysed retrospectively to assess whether disease stage at referral affects the outcome after grafting and whether greater awareness of the benefits of the procedure means that patients are now being referred at an earlier stage. Seventy of the 107 patients have been grafted, with an overall one year actuarial survival of 62%. A better prognosis at the time of referral, as assessed by both serum bilirubin concentration and a mathematically derived prognostic index, was associated with a greater probability of survival after grafting. Patients in the tertile with the best prognosis (median serum bilirubin concentration at referral 84 mumol/l and estimated survival in the absence of transplantation of more than nine months) had a 78% one year actuarial survival after transplantation, whereas those in the tertile with the worst prognosis (median serum bilirubin concentration 467 mumol/l and estimated survival of less than four months) had a one year actuarial survival of only 50%. No trend towards earlier referral of patients, however, was shown using either of these two markers. This retrospective analysis suggests that many patients are being referred too late for an optimal outcome. We recommend that patients with primary biliary cirrhosis who are potential candidates for liver grafting should be referred to a transplant centre before the serum bilirubin concentration approaches 150 mumol/l.

Adult↗

Orthotopic liver transplantation: postoperative complications and their management.

The Birmingham liver transplant programme started in 1982. Forty-six patients have been transplanted with a follow-up of 3 months or longer. Twenty-seven patients are still alive, of whom sixteen have lived for more than one year. The 30 day hospital mortality was 30.4 per cent and the actuarial predicted one year survival 55.5 per cent. Four patients have been regrafted for chronic rejection and graft failure. Thirteen patients have required surgery in the postoperative period for: bleeding (two), removal of abdominal packs (four), biliary leaks and obstruction (five), duodenal perforation (one) and small bowel obstruction (one). Acute rejection was common, occurring in 30 patients and progressing to chronic rejection in 4. Ten patients developed renal failure with an 80 per cent mortality and eleven patients developed grand mal fits. Severe bleeding (greater than 70 units) was associated with previous abdominal surgery and a high mortality (88.9 per cent). Opportunistic fungal infection carried a 100 per cent mortality. Although more than half of all transplanted patients will survive for more than one year, the postoperative period is still one of high morbidity and mortality.

Acute Kidney Injury↗

111-Indium platelets in monitoring pancreatic allografts in man.

A technique for monitoring pancreatic allografts in man is presented. The method utilizes 111-indium labelled autologous platelets and provides quantitative and qualitative analysis of uptake of the tracer by the graft. Five patients without any significant accumulation of radiolabelled platelets in their transplants had an uneventful recovery and left hospital with satisfactory graft function. The three patients who suffered graft failure showed abnormal uptake of the tracer. This presented as a diffuse platelet accumulation within the transplanted pancreas in the case of acute rejection, or as a focal accumulation in two cases of venous thrombosis. Minor complications such as perigraft haematoma can also be diagnosed using this technique. We suggest that 111-indium labelled platelets provide a valuable diagnostic aid in the management of pancreatic transplant recipients.

Adolescent↗

The current state of liver and pancreas transplantation.

The last 20 years have seen progressive developments in the field of clinical transplantation and in many countries kidney transplantation is now the most cost effective manner of treating renal failure. With increasing technical experience failures have become less common and newer immunosuppressive protocols incorporating cyclosporin A can frequently achieve a graft success rate of over 75% at one year with patient survival over 95%. In addition, the patient receiving a kidney graft attains a high quality of rehabilitation. If renal transplantation has now gained wide acceptance other forms of organ transplantation are still in a phase of development and have not yet reached wide acceptance. It is the purpose of this review to present briefly the current clinical status of two forms of solid organ transplantation being employed in clinical practice.

Adolescent↗