P.A. Gaines

A comparative analysis of radiological and surgical placement of central venous catheters

PurposeTo compare the differences in practice and outcome of all radiologically and surgically placed central venous catheters retrospectively over a 2-year period simultaneously, at a single institution.MethodsA total of 253 Hickman catheters were inserted in 209 patients; 120 were placed radiologically in 102 patients and 133 were placed surgically in 107 patients. The indication was chemotherapy in 76% of radiological and in 47% of surgical cases; the remainder were for total parenteral nutrition and venous access.ResultsThere were 6 (4.5%) primary surgical failures and a further 17 (13%) surgical cases requiring multiple placement attempts. Pneumothorax occurred once (0.8%) surgically and four times (3.3%) radiologically. There were no radiological primary misplacements but there were five (3.7%) surgical ones. Catheter or central vein thrombosis occurred in four (3.3%) radiological and five (3.7%) surgical cases. The rate of infection per 1000 catheter-days was 1.9 in radiologically placed catheters and 4.0 in surgically placed ones (p<0.001). Average catheter life-span was similar for the two placement methods (100±23 days).ConclusionRadiological placement is consistently more reliable than surgical placement. There are fewer placement complications and fewer catheter infections overall.

Percutaneous management of superior vena cava occlusions

PurposeTo assess the use of percutaneous endovascular stent insertion in the management of superior vena cava (SVC) occlusion.MethodsPercutaneous endovascular stent insertion was attempted in 13 patients, age range 20–72 (mean 55.5) years, with symptomatic total occlusion of the SVC. Twelve patients had known malignant disease of the thorax. The other patient (age 20) had chronic SVC obstruction, the cause of which was unknown at the time of the procedure. There was initial angiographic assessment and removal of thrombus by thrombolysis (10 patients) and/or clot aspiration (3 patients). Following successful lysis or aspiration, single or multiple endovascular stents were inserted.ResultsThe inability to cross the lesion with a guidewire prevented stent insertion in 2 patients (15.4%). There was primary success in the remaining 11 patients (84.6%), with associated symptomatic relief. Some recurrence of symptoms occurred in 5 of the 11 patients (45.5%) after a time interval ranging from 14 to 183 days. In all cases of symptomatic recurrence, patency was reestablished with further thrombolysis and/or further stent insertion. All successfully treated patients have since died. All 11 patients remained symptomatically free of SVC occlusion until death, with postprocedure survival ranging from 5 to 243 days.ConclusionThe percutaneous management of complete SVC occlusion with thrombolysis and/or clot aspiration followed by stent insertion is safe and effective, giving sustained symptomatic relief.

Thrombolysis of a partially occluding superior mesenteric artery thromboembolus by infusion of streptokinase.

Occlusion of the superior mesenteric artery by thromboembolism is an uncommon cause of acute intestinal ischemia but carries a high mortality. This report describes a case of mesenteric thromboembolism in an 80 year old woman treated successfully by selective lowdose infusion of Streptokinase over 17 hours. Only twelve previous cases have been reported in the world literature. Selective thrombolytic therapy appears effective in the treatment of mesenteric thromboembolism, particularly in elderly patients with a high operative risk.

Percutaneous aspiration thromboembolectomy to manage the embolic complications of angioplasty and as an adjunct to thrombolysis

Percutaneous aspiration thromboembolectomy (PAT) can be used to treat the embolic complications of angioplasty. The same technique is of value during thrombolysis to remove large pieces of thrombus. We report on our experience with PAT in 21 patients. Fourteen of these patients had embolization complicating peripheral angioplasty and in one case embolus complicated directional atherectomy. PAT was successful in 87% of these patients (13/15). In six patients undergoing thrombolysis of acute peripheral occlusions, all had successful PAT to shorten their treatment episode immediately prior to angioplasty of any underlying stenosis. PAT can be performed with a simple, inexpensive catheter under fluoroscopic control and therefore offers significant advantages over a surgical embolectomy using the Fogarty balloon catheter. PAT is a useful treatment option for the vascular radiologist.

A NEW ANIMAL MODEL FOR ABDOMINAL AORTIC ANEURYSMS : INITIAL RESULTS USING A MULTIPLE-WIRE STENT

OBJECTIVESnThe effect of a plain 48-wire self-expanding flexible stent (Wallstent-Schneider (Europe) AG) on abdominal aortic aneurysms has been studied in a new animal model.nnnMETHODSnAneurysms were created by interposing fusiform segments of glutaraldehyde-tanned bovine internal jugular vein into the infrarenal aortas of 12 Large White pigs. The first six pigs were assessed after 6 weeks by ultrasonography and arteriography; they were then sacrificed for pathological examination. Endovascular placement of the stents, 2 weeks after aneurysm creation, was performed under arteriographic control in the next six pigs. These pigs were assessed by ultrasonography and arteriography 6 weeks after stenting; they were then sacrificed for pathological examination.nnnRESULTSnAt 6 weeks the aneurysms in the first group were pulsatile with partial endothelialisation and no mural thrombus. Placement of the stent in the second group was accomplished easily. Stenting resulted in an immediate reduction in wall pulsatility of all aneurysms and thrombosis of the excluded aneurysm sac occurred in three cases. In the other three cases the pulse pressure in the sac was reduced. In all cases there was a significant reduction in maximum aneurysm diameter when measured 6 weeks after stenting.nnnCONCLUSIONSnA pulsatile, non-thrombogenic aortic aneurysm model approaching human dimensions has been successfully developed for the study of endoprostheses prior to their clinical use. Endovascular placement of a plain, multiple-wire Wallstent was associated with reductions in aneurysm pulsatility, pulse pressure within the sac and maximum aneurysm diameter over the study period. Stenting was associated with thrombosis of the excluded aneurysm sac in 50% of cases.

Treatment of intestinal angina by percutaneous transluminal angioplasty of a superior mesenteric artery occlusion

A 47-year-old woman with intestinal angina due to multiple visceral artery occlusions was treated surgically but suffered early thrombosis of an aorta-to-superior mesenteric artery (SMA) bypass graft and the return of her symptoms. Percutaneous transluminal angioplasty (PTA) of the occluded native origin of the SMA was successful. Three months later she is well and gaining weight. Several series of patients treated by PTA of superior mesenteric artery stenoses have been published, but to our knowledge this is the first report of the successful application of the technique to a complete SMA occlusion.

Percutaneous intervention for radiation damage to axillary arteries

Radiation injury to subclavian and axillary arteries is a rare and late complication of radiotherapy. Until recently it has been treated almost exclusively by carotid-brachial bypass surgery. We report three cases who presented with severe upper limb ischaemia following previous axillary radiotherapy for breast carcinoma. One patient with an axillary artery occlusion failed angioplasty and required bypass surgery. A further patient with an axillary artery occlusion was successfully managed by the percutaneous placement of an arterial stent. The third patient with an isolated axillary artery stenosis responded to balloon angioplasty. All three patients remained asymptomatic. Percutaneous angioplasty and stent placement, where necessary, are appropriate first choice treatment for delayed radiation stenosis and occlusion in upper limb ischaemia.

Thrombolysis and angioplasty for acute lower limb ischemia in Buerger's disease.

Acute lower limb ischemia secondary to Buergers disease in a young patient responded to thrombolysis and subsequent popliteal and anterior artery angioplasty. The value of angioplasty in non-limb-threatening ischemia in Buergers disease has not been established but this case illustrates a role for thrombolysis and angioplasty in acute ischemia.

Technical report: Hickman catheter rescue.

Nineteen malfunctioning or incorrectly positioned Hickman catheters from a series of 320 catheter placements were referred to the radiology department for salvage. Successful catheter rescue was achieved on 14 occasions (73.6%). Eight catheters were repositioned, five were replaced and thrombolysis was successful in a patient with subclavian vein thrombosis. Catheter repositioning techniques are reviewed and a new technique for catheter replacement using the existing venous access and subcutaneous tunnel is described.

The pharmacokinetics and UK usage of heparin in vascular intervention

Intravascular heparin is used routinely during peripheral and visceral angioplasty, although usage and dose vary widely. The aims of this prospective study were to: (1) Determine the pattern of Heparin usage by Vascular/Interventional Radiologists in the UK. (2) Determine the optimum doses of Heparin for vascular intervention on the basis of its pharmacokinetic profile. A questionnaire was sent to Consultant Radiologists who were also members of the British Society of Interventional Radiology (BSIR), regarding their use of heparin during peripheral angioplasty. This included heparin doses in flushing solution, timing and amounts of heparin used as a bolus dose and monitoring of clotting times. Seventy-three percent returned completed forms. A wide variation in practice was shown. Apart from the variety of individual protocols in use, significant findings were that more than 75% of the respondents were giving heparin as a bolus only after the lesion had been crossed with a guide-wire. None of the respondents were monitoring clotting times, even in prolonged and complicated procedures. The pharmacokinetic profiles of two separate bolus doses of heparin in two groups of 30 and 25 patients each were then evaluated. Our results showed that a 3000 IU bolus of heparin maintained the plasma APTT in the therapeutic range (at least twice the normal value), for at least 30 min in the majority of patients. A 5000 IU bolus maintained the APTT in the therapeutic range for 45 min in the vast majority of patients. Apart from minor bruising at the compression site and slightly increased compression times in a small number of patients, no significant immediate complication was noted. We conclude that in the context of peripheral angioplasty, there is a wide variation in the use of heparin as an adjunct to the procedure. In the light of our own experience we recommend a 3000 IU intra-arterial bolus of unfractionated heparin to be given once arterial access has been achieved. This would cover short, uncomplicated procedures. The larger 5000 IU dose would be more appropriate for longer and more complicated procedures. We also recommend monitoring APTT values in prolonged procedures, with administration of further bolus doses of heparin if required.