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Biomedical subjects

R H Gregson

Publications and source records attributed to R H Gregson.

47 records · Page 3Linked to original sources
PubMed1989

Intra-arterial thrombolysis using recombinant tissue plasminogen activator (r-TPA): the optimal agent, at the optimal dose?

Thirteen patients received 15 separate courses of intra-arterial (IA) r-TPA for acute and subacute peripheral arterial thromboses. Two patients received second courses: one following rethrombosis 2 weeks after the angioplasty of a residual stenosis, the other following rethrombosis 4 months after the initially successful thrombolysis. There were 10 men and 3 women with a mean age of 75.3 yrs (+/- 12.2). The median duration of ischaemia was 18 days (range 1-60), with five patients having severe ischaemia. All patients received IA r-TPA at a dose of 0.5 mg/h for a mean period of 26.2 hrs (+/- 12.6). Angiographic evidence of lysis was seen in all patients, however, this was insufficient to reperfuse the distal limb in two patients due to absence of run-off. Early rethrombosis occurred in both of these patients (less than 24 hrs, 11 days). There were no major complications, and minor groin haematomata occurred in four patients (three of whom underwent angioplasty). A further two patients rethrombosed despite angioplasty. One was successfully retreated and remains patent 5 months later, the other underwent surgical reconstruction. A partial systemic effect was confirmed by a reduction of plasminogen and fibrinogen to 66% of initial levels, and a reduction of alpha - 2-antiplasmin to 40% of initial levels. Haemoglobin was reduced by a mean 1.28 g/dl (+/- 0.82), however no transfusions were required, and no hypotensive periods occurred. Mean ankle/brachial systolic index (ABSI) was increased by 0.43 (+/- 0.24) overall.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1989

Transluminal iliac angioplasty with distal bypass surgery in patients with critical limb ischaemia.

Transluminal balloon angioplasty of the iliac artery was combined with a distal bypass graft procedure in 25 patients with critical ischaemia of the lower limb. Eleven patients had angioplasty in the operating theatre before a vascular graft and the remaining 14 patients had percutaneous transluminal angioplasty performed in the X-ray department before bypass surgery. The distal bypass grafts were 20 femoropopliteal and five femorofemoral grafts. Two patients died in the immediate postoperative period. Follow-up of patients ranged from 2 to 26 months with a graft patency of 63% at 12 months and 50% at 24 months but successful limb salvage rate of 75% at 12 and 24 months. Six patients required major amputations for failure of limb salvage. Transluminal iliac angioplasty is a valuable adjunct to distal bypass surgery by improving arterial inflow without the requirement for major aorto iliac surgery.

Actuarial Analysis↗
PubMed1988

Local thrombolytic therapy of acute peripheral arterial ischaemia with tissue plasminogen activator: a dose-ranging study.

Low-dose streptokinase has been established as an alternative to surgery in selected patients with acute peripheral arterial ischaemia. Tissue plasminogen activator (t-PA) is responsible for normal plasma fibrinolytic activity and has recently become available for clinical use owing to recombinant DNA technology. It has the theoretical advantage of fibrin specificity, which may result in enhanced thrombolytic effects with greater safety. Twenty-three patients with recent lower limb arterial occlusions received t-PA over a tenfold range of concentrations and five patients received low-dose streptokinase. One month after treatment with t-PA or streptokinase 19 (68 per cent) patients had limb salvage, five (18 per cent) had required amputations and four (14 per cent) had died. Systemic fibrinolytic effects were variable but basically dose related. Haemorrhage occurred most frequently at the highest t-PA concentration and was major in four (17 per cent) cases, including a fatal stroke. Plasma fibrinogen concentration fell below 1.2 gl-1 in five (22 per cent) patients who received t-PA and was found to be a significant risk factor for haemorrhage, t-PA was an effective thrombolytic agent at all concentrations studied. The dose currently used in clinical studies at this institution is 0.5 mg h-1.

Acute Disease↗
PubMed1987

Early results of low dose intra-arterial streptokinase therapy in acute and subacute lower limb arterial ischaemia.

Thirty-two patients with acute and subacute limb-threatening peripheral arterial ischaemia were treated with low dose intra-arterial streptokinase infusions. The mean duration of infusion was 38 h. Six patients developed pericatheter thrombosis and two had distal embolization of fragments of thrombus but in all cases these responded to repositioning the catheter and continuing the infusion. Five patients developed groin haematomata and in three of these there was evidence of a systemic fibrinolytic effect from the streptokinase with plasma fibrinogen reduced below 1 g/l. The most serious complication was perforation of the popliteal and tibial arteries which occurred on two occasions and required cessation of the infusion. Twenty-two patients (69 per cent) achieved limb salvage, eight (25 per cent) suffered a major amputation and two (6 per cent) died. The outcome was not related to the site, nature or duration of the arterial occlusion but patients with loss of sensation or paralysis of the affected limb were significantly less likely to obtain limb salvage (P = 0.001). For occlusions greater than 30 cm in length a new technique was used where the thrombus was lysed from distal to proximal in short lengths by gradual catheter withdrawal. This was successful in five out of six cases. Low dose intra-arterial streptokinase has been confirmed as an effective, relatively safe method of treatment in recent arterial ischaemia and can be recommended in situations where the results of surgery may not be favourable. In particular, patients with arterial thromboses and no distal run-off, distal and late arterial emboli, thrombosed popliteal aneurysms and patients after a failed embolectomy, have all been shown to respond to thrombolytic therapy with intra-arterial streptokinase.

Adult↗
PubMed1987

Accuracy of identification of early gastric cancer.

Two hundred and nineteen patients underwent gastrectomy for cancer in Nottingham University Hospital between January 1978 and December 1985. Twenty of these patients had early gastric cancer (EGC). Barium meal was performed in 15 patients and upper gastrointestinal endoscopy in 15. In all cases, barium meal failed to define the early nature of this disease. Only two lesions were thought to be EGC endoscopically and at laparotomy three were considered to be EGC. As neither radiologist, endoscopist nor surgeon can reliably identify EGC, all patients with gastric cancer in the absence of proven metastases should undergo gastrectomy.

Adenocarcinoma↗
PubMed1987

Is ureteric compression still necessary?

A prospective randomised trial was performed to examine the value of ureteric compression in intravenous urography. Calyceal distension improved during the urogram in 68% of kidneys when compression was used, in contrast to an improvement of 43% in patients not receiving compression. In both heavy patients and those with a large girth a trend towards improved distension was shown but was significant only in the former group.

Body Weight↗
PubMed1987

Popliteal artery perforation during low dose intra-arterial streptokinase infusion.

There has been a recent increase in the use of low dose intra-arterial streptokinase infusion for the management of patients with acute peripheral arterial occlusions. Though serious complications using this technique occur less frequently than when using systemic thrombolytic therapy, a case is reported where the catheter used to infuse streptokinase perforated the popliteal artery 36 hours after the infusion commenced. The use of softer arterial catheters and restriction of patient movement where possible may prevent the recurrence of this previously unreported hazard.

Catheterization↗
PubMed1984

A comparison of nuclear magnetic resonance and intravenous xeroangiography with conventional arteriography in popliteal artery imaging.

Twenty-nine patients with peripheral vascular disease had the popliteal artery segment assessed by xeroangiography and nuclear magnetic resonance (NMR) scanning. The result of each test was compared with conventional contrast arteriography. Nuclear magnetic resonance and xeroangiography correctly predicted popliteal artery patency in 97% and 100% of limbs, respectively, and occlusion was correctly predicted in 44% and 63% of limbs. The ability of xeroangiography to define the state of the popliteal artery accurately makes this a useful method in high-risk patients. The potential for NMR imaging appears very promising but more work is required to define its future clinical application.

Adult↗
PubMed1983

Spontaneous aorto-caval fistulae.

The clinical and radiological presentation of four cases of spontaneous aorto-caval fistula is described. This is an unusual complication of an abdominal aortic aneurysm and presents with abdominal pain, a pulsatile abdominal mass and an abdominal bruit. Our cases illustrate the variable clinical presentation, outline the diagnostic difficulties and confirm the value of aortography. A possible role for the radiologist using a balloon catheter to close the fistula prior to surgery is suggested.

Aged↗