A stable prostacyclin analogue (iloprost) in the treatment of ischaemic ulcers of the lower limb. A Scandinavian-Polish placebo controlled, randomised multicenter study

The clinical efficacy of the prostacyclin analogue iloprost was studied during a 2 week treatment and 6 month follow-up period in 103 patients with ischaemic ulcers who were randomised to receive active treatment or placebo. Responders were defined as those patients who achieved healing of at least one third of the ulcer area during the study period. The overall responder rate was 41.3%, compared with 25% for the control group (P = 0.086). Side effects including flushing and headache, were common. The study population had a mortality of 23% during the 6 month period, the amputation rate was 43.5% for iloprost and 50% for placebo treated patients. In this severely diseased population of patients a treatment period limited to 2 weeks did not sufficiently improve ulcer healing.

Immune response to collagen impregnated Dacron double velour grafts for aortic and aorto-femoral reconstructions

This study presents 20 patients, randomised to receive either a collagen-treated or an ordinary Dacron graft for aortic reconstructions, and the results of a skin-prick test, blood parameters and ELISA for anti-collagen antibodies as well as NMR pictures during a 6 week follow-up period. Forty per cent (4/11) of those receiving a collagen impregnated graft had a significantly increased titre of antibodies and NMR revealed in two out of 11 patients either a slightly increased amount of fluid or fibrosis around the graft, both collagen impregnated. No differences were found between the graft groups concerning body temperature and leucocyte or platelet counts. The skin-prick test for collagen was negative in all cases.

Intestinal hemodynamics during laparotomy: effects of thoracic epidural anesthesia and dopamine in humans

The effects of thoracic epidural anesthesia (TEA) and dopamine infusion (4 micrograms.kg-1.min-1) on superior mesenteric artery blood flow (SMABF), the mesenteric arteriovenous oxygen difference (AVDO2), and the mesenteric venous lactate concentration were studied in nine patients before abdominal aortic reconstruction. Thoracic epidural anesthesia reduced SMABF, as measured by electromagnetic flowmetry, to 77% +/- 8% (mean +/- SEM) of control (P less than 0.05), and mean arterial pressure to 46% +/- 4% of control (P less than 0.01). The mesenteric AVDO2 increased from 27 +/- 3 to 39 +/- 6 mL/L (P less than 0.05) and superior mesenteric venous lactate from 1.03 +/- 0.11 to 1.60 +/- 0.38 mmol/kg (P less than 0.05); systemic AVDO2 and lactate did not change. Dopamine had no significant effect on SMABF and mean arterial pressure before TEA. However, dopamine increased SMABF during TEA (from 77% +/- 8% to 137% +/- 21% of control; P less than 0.01), returned mesenteric AVDO2 to 27 +/- 3 mL/L (P less than 0.05), and elevated mean arterial pressure to 62% +/- 4% of control (P less than 0.05). It is concluded that the decrease in perfusion pressure during TEA reduces SMABF with resultant evidence of intestinal reductive metabolism. The intestinal blood flow during TEA was improved by dopamine.

Dopamine counteracts hypertension during general anesthesia and hypotension during combined thoracic epidural anesthesia for abdominal aortic surgery

The influence of the degree of sympathetic nervous system activation on the cardiovascular effects of dopamine was studied during abdominal aortic surgery in 13 patients. The arterial plasma norepinephrine concentration (NE) was used as an index of sympathetic nervous system activity. During anesthesia with nitrous oxide and fentanyl, 7 patients (group 1) had a NE above 700 pg/mL and an increased mean arterial pressure (MAP) compared with the preanesthetic level (150 +/- 6 v 117 +/- 10 mm Hg; p less than 0.01, mean +/- SEM). The other 6 patients (group 2) had no significant change in MAP compared with the preanesthetic MAP (119 +/- 7 v 105 +/- 4 mm Hg). Dopamine, 4 micrograms/kg/min, decreased MAP in group 1 by 19% (150 +/- 6 to 121 +/- 8 mm Hg; P less than 0.05) because of a 32% +/- 9% decrease (P less than 0.05) in systemic vascular resistance. MAP was not altered by dopamine in group 2 (119 +/- 7 v 123 +/- 6 mm Hg; not significant). Following termination of dopamine, the anesthetic was supplemented with thoracic epidural anesthesia (TEA). This reduced MAP to 65 +/- 7 mm Hg (P less than 0.01) and 56 +/- 3 mm Hg (P less than 0.01), and NE to 441 +/- 76 (P less than 0.05) and 235 +/- 45 pg/mL (P less than 0.05) in groups 1 and 2, respectively. During TEA, dopamine increased MAP similarly in both groups, to 85 +/- 7 mm Hg (P less than 0.01) and 82 +/- 9 mm Hg (P less than 0.05), respectively. In conclusion, dopamine, at the same dosages, counteracted hypertension during general anesthesia and counteracted hypotension during general anesthesia combined with TEA.

Contractility of human leg lymphatics during exercise before and after indomethacin

Subcutaneous lymphatics in the lower leg were catheterized in the retrograde direction in 6 healthy male subjects. The catheter was connected to a pressure transducer, and pressure was measured during three stages of exercise including standing, tip-toeing, and running in place. Before the third stage, indomethacin (50mg) was given i.v. Rhythmic pressure waves were registered in each subject. During the second stage, when the subjects were "warmed up," the frequency (min-1) was 2.4 +/- 0.5 (mean +/- SEM). The corresponding values during tip-toeing and running were 5.8 +/- 0.7 (p less than 0.05) and 5.4 +/- 0.5 (p less than 0.05), respectively. The amplitudes (mean values between 3.2-4.7mmHg while standing) were not consistently altered during tip-toeing or running in any of the three stages. During standing there was a negative correlation between frequency and amplitude. No such correlation was found during tip-toeing or running, or after injection of indomethacin. Indomethacin did not significantly alter any of the measured parameters, but in two subjects the frequencies and amplitudes were decreased (about 50%) during standing, tip-toeing, and running.

Direct evidence of active sympathetic vasodilatation in the skin of the human foot

1. During operative aorto-femoral vascular reconstructions on sixteen patients, the sympathetic chain was stimulated electrically between the L2 and L4 ganglia while blood flow was monitored by laser doppler flowmeters from the skin on the sole of the foot and the ankle and by an electromagnetic flowmeter from the deep femoral artery. Epidural anaesthesia to at least the T6 level was used which excluded reflex effects. 2. Stimulation (10 Hz) at 1-12 mA current strengths for 30 s evoked both reductions and increases of blood flow in glabrous and hairy skin. Initial short-lasting flow increases (durations 9-19 s) followed by sustained decreases were common: sometimes there were sustained flow increases at low and decreases at high current strengths. 3. In the deep femoral artery (supplying predominantly muscle) only flow reductions were evoked. 4. The results provide evidence for sympathetically mediated vasodilatation in the skin of the human foot whereas leg muscles may be supplied by vasoconstrictor nerves only.

Antagonism of thromboxane receptor induced contractions in isolated human groin lymphatics

In vitro studies were performed on lymphatics obtained from the groin in 19 patients undergoing vascular surgery. The lymphatics were mounted in tissue baths, and isometric contractions were induced by increasing concentrations of the thromboxane A2 (TXA2) mimetic U-46619. In comparison to K+ (124mM)-induced contraction, which were used as an internal standard, the response to U-46619 had an Emax of 105 +/- 5.9%. The pEC50-value was 8.14 +/- 0.09. The effects of two thromboxane receptor (TP-receptor) antagonists, L-636,499 and BM-13,505, were investigated. Both antagonists caused concentration-dependent right-ward shifts without depression of Emax of the U-46619 concentration-response curves. The slopes of the regression lines in a Schild plot for both antagonists did not differ from one, indicating competitive antagonism. The pA2-value of BM-13,505 (7.89) was 65 times higher than that of L-636,499 (6.08). The results suggest that the receptor involved in the prostanoid contraction in human groin lymphatics is of the TP-subtype.

Infections and antibiotic prophylaxis in reconstructive vascular surgery

In 98 patients undergoing elective vascular surgery, specimens for bacterial cultures were obtained from urine, ischaemic ulcers, incisional wounds and the implanted grafts. Wound and graft infections were registered and compared with the results of these cultures and suspected risk factors in an attempt to find the source of infections. Antibiotic prophylaxis with cefuroxime was given for 24 h beginning at the start of surgery. Patients with ischaemic ulcers also received "spread prophylaxis", directed against isolated bacteria, for ten days. Three cases of graft infection and twelve cases of wound infection occurred. Positive postoperative cultures from wounds did not correlate with pre- or peroperative cultures. Peroperative cultures revealed small numbers of staphylococcus epidermidis in eleven patients, and none of them developed graft infection. Ischaemic ulcers, diabetes or re-do procedures were not accompanied by a significantly increased frequency of wound or graft infection, although each of three patients with graft infection had one of these risk factors. Bacteria, sensitive to cefuroxime, were found in one graft infection, six wound infections, and in two patients with urosepsis, whereas cefuroxime resistant organisms were isolated from one graft infection and three infected wounds. One of the three graft infections was probably caused by bacteria originating from the patient's ischaemic ulcer. In the other two patients the source of bacteria could not be determined. Cefuroxime seems to be an adequate alternative for prophylaxis of vascular graft infection, but in some patients with bacteriuria or indwelling catheters, a one day regimen may be too short.

Comparative effects of the alpha-adrenoceptor agonists noradrenaline, phenylephrine and clonidine in the human saphenous vein in vivo and in vitro

The alpha-adrenoceptor-mediated contractile effects of noradrenaline (alpha 1 + alpha 2), phenylephrine (alpha 1) and clonidine (alpha 2) on human saphenous veins were investigated in vivo and in vitro. By infusion (0.3 ml min-1) of the drugs (increasing concentrations in the infused solution) into distended (40 mmHg) saphenous veins in six healthy subjects, local vasoconstriction was induced, measured by a photo-electric device. The drugs induced dose-dependent contractions in all subjects, and dose-response curves were constructed. These were compared with concentration-response curves based on in-vitro results. Macroscopically normal saphenous veins, taken at saphenousectomies, were used, and the preparations were contracted isometrically in organ baths by the agonists. From the curves obtained in vivo and in vitro, the relative potencies of phenylephrine and clonidine (in relation to noradrenaline) were calculated and compared. The relative potencies of phenylephrine in vivo (76%) and in vitro (82%) did not differ significantly. However, the relative potency of clonidine was significantly (P less than 0.05) lower in vivo (90%) than in vitro (99%). Thus, it is concluded that there are differences between the results obtained in vivo and in vitro, stressing the importance of comparative in vivo-in vitro studies.

Beneficial effects of intra-arterial reserpine after upper-extremity embolectomy: a prospective randomised trial

Persistent ischaemia occasionally follows technically-successful arterial embolectomy, and has generally been ascribed to small-vessel thrombosis in the distal vascular bed. Because of the possibility that distal vasospasm might be a contributory cause, we conducted a prospective randomised trial of vasodilator therapy in this setting. In 50 consecutive patients presenting with their first episode of upper-extremity arterial embolism, we compared the results of the intra-arterial instillation of 0.5 mg reserpine with those of saline alone following embolectomy. Among 29 patients receiving saline only, 13 (44.8%) suffered persistent or recurrent limb ischaemia requiring reoperation, while three (14.3%) of 21 patients receiving reserpine had continuing ischaemia (P = 0.02). Three patients in each group required a second re-operation; all three in the reserpine group were ultimately found to have a proximal axillo-subclavian artery stenosis as the cause for their persistent or recurrent limb ischaemia. Although its underlying pathophysiology remains obscure, peripheral vasospasm appears to accompany acute embolic arterial occlusion. Manoeuvres to prevent or reverse such distal vasoconstriction may be useful in avoiding persistent or recurrent ischaemia following arterial embolectomy.

Elastic compression stockings--an evaluation with foot volumetry, strain-gauge plethysmography and photoplethysmography

Foot volumetry, strain-gauge plethysmography and photoplethysmography were performed on 15 patients testing three different elastic stockings. Improvement of venous function and enhancement of the musculovenous pump effect was shown at foot volumetry and photoplethysmography. No effect on refilling times was found.

Experimental evaluation of small diameter synthetic arterial grafts

Platelets labelled with Indium-111 were used to examine the in vivo thrombogenicity of different vascular grafts. The deposition of platelets in two partly different kinds of umbilical vein grafts, double velour Dacron grafts and double velour Dacron grafts with internal collagen was studied as a function of time. The grafts were inserted end to side in the femoral artery of pigs and then imaged for 120 minutes. Platelet distribution was also studied by in vitro static imaging. No difference was seen between the different umbilical vein grafts. The double velour grafts accumulated more platelets, the platelets mainly located in the midportion of the graft. The collagen-impregnated grafts occluded within 45 minutes.

Four years' results of a prospective, randomized clinical trial comparing polytetrafluoroethylene and modified human umbilical vein for below-knee femoropopliteal bypass

Polytetrafluoroethylene (PTFE) (Gore-Tex) and human umbilical vein (Biograft) arterial grafts were compared for below-knee femoropopliteal bypass grafting in a prospective randomized clinical trial. One hundred five patients (105 limbs) entered the trial. Seventy-six percent suffered from rest pain, ulceration, or gangrene. The median postoperative ankle-arm blood pressure index was 0.36. Twenty-three limbs had three patent tibial arteries, 46 limbs had two tibial arteries, 31 limbs had one patent artery, and five limbs had isolated popliteal segments. Thirty-four percent were repeat operations. Fifty-five patients were allocated to receive PTFE grafts and 50 to receive human umbilical vein grafts. The two groups were comparable as to preoperative risk factors and operative and postoperative treatment. During the first 4 years (maximum 1609 days) 40 PTFE grafts and 24 umbilical veins occluded. At 1 year the PTFE patency rate was 53% and at 4 years was 22%. For umbilical vein the corresponding figures were 74% and 42% (p = 0.005, Gehan test). During follow-up the incidence of PTFE failure was on the average 2.1 times higher than that of umbilical vein failure (95% confidence limits 1.2 to 3.4).

Neurovascular injury complicating displaced proximal fractures of the humerus

Three cases with injury of the axillary artery and brachial plexus complicating a displaced proximal fracture of the humerus are presented. In two patients the arterial injury was not recognized on admission. Vascular repair had to be carried out in all three cases. Two patients showed a persistent neurological deficit. In two of the cases, the arterial injury may have been caused by an attempt at closed reduction of the fracture. The possibility of axillary arterial injury should be considered in proximal fractures of the humerus with severe medial displacement of the shaft of the humerus.

Contractile response in isolated human groin lymphatics

Lymphatics from the human superficial groin removed at operation in 21 patients (one with lymphedema) were examined in vitro. Histochemically no nerves were identified with either specific catecholamine fluorescence or immunoreactivity to tyrosine hydroxylase or dopamine beta-hydroxylase. Ring preparations of the lymphatics were mounted in tissue baths and isometric induced contractions were recorded after administration of K+ (124 mM), acetylcholine, selected amines and prostanoids. Noradrenaline (NA), adrenaline, dopamine, and acetylcholine had no or only weak contractile effects. In some segments, serotonin induced contractions. Prostaglandin E2 showed no contractile effect and prostaglandin F2 alpha induced contraction in most of the tested lymphatics. The prostaglandin-endoperoxide analogue U44069 uniformly elicited marked concentration-dependent contraction. In the lymphatic segment from the patient with lymphedema, a slightly greater contractile response to NA and serotonin was observed. The results overall suggest an absence of sympathetic innervation and contraction-mediating alpha adrenergic receptors in human superficial groin lymphatics, and support that certain prostanoids may be important regulators of human lymphatic contractility.

Comparative effects of some calcium-channel blockers on human peripheral arteries and veins

We investigated the effects of five different calcium-channel blockers (CCBs), verapamil, nifedipine, diltiazem, flunarizine and lidoflazine, on contractions evoked in vitro by noradrenaline (NA) in small human arteries and veins from the epigastric region. Vessels were obtained from patients without obvious vascular diseases undergoing surgery because of inguinal hernias. The human superficial epigastric artery has previously been shown to contain mainly alpha 1-adrenoceptors, whereas in the vein alpha 2-adrenoceptors predominate. In experiments where NA (10(-5) M) was added non-cumulatively, it was found that nifedipine was the most potent relaxant agent in both arteries and veins, but that this drug showed no preference for any type of vessel. In contrast verapamil (10(-6) M) and (10(-5) M) diltiazem, flunarizine and lidoflazine inhibited the NA-induced contractions to a significantly greater extent in the arteries than in the veins. Comparison between diltiazem and nifedipine on contractions induced by cumulative addition to NA showed that both drugs had significantly more depressive effects on arteries than on veins if the vessels were contracted by relatively high concentrations of NA (10(-6) and 10(-5) M). The results thus confirm the clinical finding that CCBs have more pronounced effects on the arterial than on the venous side of the circulation. They do not support the view that CCBs are more effective inhibitors of alpha 2- than alpha 1-adrenoceptor mediated contraction in isolated human blood vessels.

Digital subtraction angiography with bandpass filtration during by-pass operation

Experience is reported on a simple, inexpensive video processor for angiographic control during operation. In 6 patients with graft complications instant operative corrections could be performed.

Hemodynamic effects of dopamine during thoracic epidural analgesia in man

The cardiovascular effects of dopamine were studied before and during thoracic epidural analgesia (TEA) in eight patients prior to abdominal aortic surgery. Dopamine was infused at rates of 2, 4, and 8 micrograms X kg-1 X min-1. Mean plasma dopamine concentration increased proportionally to the infusion rate. Before TEA, dopamine 8 micrograms X kg-1 X min-1 decreased systemic vascular resistance 4 +/- 4 mmHg min X 1-1 (m +/- SD) (P less than 0.05), but increased mean arterial pressure 15 +/- 12 mmHg (P less than 0.01), cardiac output 1.9 +/- 1.0 1 X min-1 (P less than 0.01), heart rate 10 +/- 9 beats X min-1 (P less than 0.05), and plasma norepinephrine concentration 544 +/- 252 pg X ml-1 (P less than 0.01). After the induction of TEA, which extended above the T2 dermatome and below the L2 dermatome, saline and albumin were infused to maintain central venous and pulmonary capillary wedge pressures. TEA reduced mean arterial pressure from 96 +/- 18 to 55 +/- 8 mmHg (P less than 0.01), cardiac output from 4.7 +/- 0.9 to 3.9 +/- 0.9 1 X min-1 (P = 0.05), systemic vascular resistance from 21 +/- 6 to 14 +/- 3 mmHg min X 1-1 (P less than 0.05), and plasma norepinephrine concentration from 394 +/- 141 to 207 +/- 73 pg X ml-1 (P less than 0.01). The plasma epinephrine concentration was reduced 49% after the induction of TEA.(ABSTRACT TRUNCATED AT 250 WORDS)

Postjunctional alpha-adrenoceptors in human superficial epigastric arteries and veins

A pharmacological characterization of the postjunctional alpha-adrenoceptors in human superficial epigastric artery and vein was performed, using several alpha-adrenoceptor subtype selective agonists, and the antagonists prazosin (alpha 1) and rauwolscine (alpha 2). In the arteries prazosin fulfilled the criteria for a competitive antagonism in concentrations 10(-9)-10(-7) M, giving a pA2-value of 9.17 in the Schild plot. Rauwolscine in concentrations 10(-8)-10(-6) M caused less pronounced but significant dextral shifts of the noradrenaline (NA) concentration-response curves. In the veins rauwolscine behaved like a competitive antagonist (10(-8)-10(-7) M). The pA2-value was 9.16. Prazosin 10(-9) M displaced the NA concentration-response curve, but higher concentrations (10(-8) and 10(-7) M) caused no further displacement. Prazosin reduced the Emax-values in the veins. In the arteries the rank order of potency for the agonists was: cirazoline (alpha 1) greater than NA greater than naphazoline (alpha 2) greater than guanfacine (alpha 2) greater than phenylephrine (alpha 1). The intrinsic activities of clonidine (alpha 2), ST 587 (alpha 1), B-HT 920 (alpha 2) and B-HT 933 (alpha 2) were too low to allow meaningful comparisons to be made. The rank order of potency in the veins was: NA greater than clonidine (alpha 2) greater than naphazoline (alpha 2) greater than guanfacine (alpha 2) greater than phenylephrine (alpha 1) greater than B-HT 920 (alpha 2) greater than cirazoline (alpha 1) greater than B-HT 933 (alpha 2). The intrinsic activity of ST 587 was low.(ABSTRACT TRUNCATED AT 250 WORDS)

Follow-up evaluation of venous morphologic factors and function after thrombectomy and temporary arteriovenous fistula in thrombosis of iliofemoral vein

Fifty-seven patients (58 post-thrombotic legs) treated with venous thrombectomy and temporary arteriovenous fistula for thrombosis of the iliofemoral vein were evaluated in a follow-up study regarding clinical, morphologic and functional aspects nine to ten months after thrombectomy. There were 33 men and 24 women, between 15 and 84 years of age (a mean of 51 years). The results of clinical examination revealed that 75 per cent of the patients had a good and 20 per cent a fair result of the treatment. No ulcers of the leg or venous claudication had developed. Venography (53 legs) demonstrated 61 per cent patency rate of the iliofemoral segment, although post-thrombotic changes were noted in 23 per cent. Venous femoral pressure measurement was normal in 82 per cent of 28 legs examined despite some proximal stenosis or occlusion. A good venous emptying with plethysmography was achieved in 29 per cent and foot volumetry showed normal peripheral venous function in 29 per cent. The results of this follow-up study, however short, reveal that venous patency can be restored to a high extent with good clinical result. Functionally, these patients may be at high risk for having sequelae develop later.

The effect of pneumatic antishock garments in the treatment of lethal combined hepatic and caval injuries in rats

Thirty rats were subjected to a standardized lethal hepatic and retrohepatic caval vein injury. The animals were divided into six groups. In addition to controls (I), the animals were treated with a pneumatic antishock garment (PASG) (II), massive intravenous (III), or intra-aortic (IV), saline infusion, or PASG in combination with either massive intravenous (V) or intra-aortic (VI) saline infusion. Intravenous and intra-aortic infusion of saline led to a median survival time of 13 min and 37 min, respectively, not statistically different from the control group. Nine of ten animals who had the combined treatment with PASG and infusion of saline developed a fulminant pulmonary edema. The treatment with PASG alone, however, prolonged survival time significantly from a median survival time of 10 min in the control group, to greater than 120 min in the treated group.