Prospective randomized placebo-controlled trial of aprotinin for elective aortic reconstruction.

BACKGROUND: The serine protease antagonist, aprotinin, reduces perioperative blood loss in cardiac surgery and orthotopic liver transplantation. A pilot study suggested that the drug may also reduce bleeding during infrarenal aortic replacement; the aim was to confirm or refute this observation with a prospective, randomized, double-blind, placebo-controlled trial. METHODS: Some 136 patients were randomized to receive either aprotinin, given as a loading dose of 2 x 10(6) kallikrein inactivator (KI) units followed by 0.5 x 10(6) KI units/h or equal volumes of 0.9 per cent saline. After 80 patients had been randomized the infusion dose was doubled to ensure that plasma levels were similar to those seen in successful cardiac studies. Blood loss, coagulation and haematological parameters were recorded throughout surgery and for 7 days afterwards. Blood was transfused to maintain the haemoglobin level at 100 g/l. RESULTS: Four patients were withdrawn after randomization when found at laparotomy to be unsuitable for the planned reconstruction. The 30-day mortality rate was 4.5 per cent, with no excess complications in either group. Blood loss collected on swabs was reduced from 480 ml in placebo-treated patients to 379 ml with aprotinin (P = 0.014). Blood loss into suction drains in the first 24 h after operation was reduced from 295 to 205 ml in aprotinin-treated patients (P = 0.002). However, no significant reduction was found in intraoperative or total blood loss, or transfusion requirement. CONCLUSION: The small reduction in blood loss in patients treated with aprotinin demonstrated in this study does not support its use in routine elective aortic surgery.

Non-invasive monitoring of cardiac output changes during aortic cross-clamping for infrarenal reconstruction--a new technique using suprasternal Doppler-derived cardiac output.

There is a significant morbidity and mortality associated with elective infrarenal aortic reconstruction. To examine the value of continuous cardiac output monitoring for predicting those at risk, 40 consecutive patients were monitored using Doppler-derived cardiac output. The anaesthetist was blind to all information from the monitor and managed the patients using standard techniques. In 28 patients there were no observed changes, while in seven, cardiac output rose after aortic cross-clamping. In five patients a fall in cardiac output occurred after cross-clamping. No cardiac events or cardiac deaths occurred in the 35 patients who showed a rise or no change in cardiac output. However, there were three cardiac events, including one cardiac death in the group of five patients in whom a fall in cardiac output was observed. It would appear that intraoperative non-invasive Doppler-derived cardiac output monitoring successfully predicts high-risk patients who would perhaps benefit from more intensive pre-, peri- and postoperative care.

Continuing experience with transaxillary excision of the first rib for thoracic outlet syndrome.

The results of transaxillary excision of the first rib for thoracic outlet syndrome are reported. During a 3-year period, 40 transaxillary rib resections were performed on 32 patients. The symptoms in 33 limbs were completely relieved and in a further four symptoms were improved. These results confirm that transaxillary excision of the first rib is the operation of choice in the management of thoracic outlet syndrome.

Prospective randomised evaluation of a new cell saving device in elective aortic reconstruction.

In order to evaluate the clinical and haematological implications of salvage autotransfusion using the Haemolite device (Haemonetics, Leeds, UK), 67 aortic reconstructions were studied. Bank blood transfused during the operation fell from a median of four units in the control group to zero using the cell saver (P less than 0.0001), and wound drainage decreased from 250 to 200 ml (P = 0.12). Evidence of fibrinolytic and platelet activation was found during salvage, but no bleeding diathesis was encountered. There was no morbidity or mortality related to the technique, and median hospital stay was reduced in autotransfused patients. The Haemolite is a safe effective device for autotransfusion in elective aortic surgery, and can substantially reduce exposure of both patients and staff to the dangers of homologous blood.

Local audit in vascular surgery.

A 2-year audit of the Southampton Vascular Unit showed marked discrepancies in workload from nationally accepted figures. All forms of reconstructive surgery except emergency aortic aneurysm grafting were performed more frequently than expected. The vascular population is elderly and at high risk from major surgery. Mortality was appreciable in all major vascular procedures and usually cardiac or renal related. The elderly population and resulting workload is likely to increase in the near future. The role of local audit in vascular surgery is emphasised.

The Southampton teaching triad: an audit of operative surgical instruction.

Clinical audit and regular morbidity and mortality meetings are required of all units involved in surgical training. Agreed standards of training are under discussion in the face of new examinations and have not at present been formally evaluated. In order to quantify the level of operative surgery instruction in this unit, a prospective 'Teaching Audit' has been undertaken, using an extension of the existing surgical audit. Results, which are presented as a standardised diagram, reflect the relationship between trainer and trainee. Problems, such as missed teaching opportunities, were identified. The method can be applied to any specialty, and may be useful in planning teaching resources and surgical training programmes.

First rib resection for vascular complications of thoracic outlet syndrome.

The surgical approach to vascular complications of the thoracic outlet syndrome remains controversial. When present, removal of a cervical rib alone has produced disappointing results. Our experience of 29 consecutive first rib excisions over a 5-year period is presented. Of 20 cases with uncomplicated subclavian artery compression 19 were cured, and of six cases with aneurysm or thrombosis five were improved. Of 12 cases with neurological symptoms nine were cured and two were improved. It is suggested that first rib excision is the essential primary treatment for patients with arterial symptoms due to thoracic outlet syndrome.

Varicose vein surgery using a pneumatic tourniquet: reduced blood loss and improved cosmesis.

A prospective controlled randomised study has been performed of 100 consecutive patients undergoing varicose vein surgery. One group underwent saphenofemoral flush ligation and multiple lower leg avulsions with the leg exsanguinated with a Rhys-Davies cuff, and ischaemia maintained with a pneumatic tourniquet. The other group underwent identical surgery but with a 30 degree head down tilt only. Blood loss was significantly less (13.5 +/- 12 ml vs 133 +/- 78 ml; P less than 0.01) and postoperative cosmesis was significantly improved in patients in the tourniquet group. Operating time was similar (27 +/- 11 min vs 30 +/- 13 min) in the two groups.

Inflow site: its effect on femoropopliteal and distal graft patency.

In a series of 245 vein grafts, results of 163 from the common femoral artery were compared with 82 from the proximal superficial femoral artery. Groups were comparable for risk factors, except that significantly more of the superficial femoral artery group were anastomosed to a single calf vessel (P less than 0.02). Early technical failure was similar in both groups (14 per cent common femoral artery, 12 per cent superficial femoral artery, P = n.s.). Cumulative life table patency rates at 1 and 3 years were 77 per cent and 72 per cent in common femoral artery grafts, and 80 per cent and 70 per cent in superficial femoral artery grafts (P = n.s.). Analysis of 92 veins in situ (65 common femoral artery and 27 superficial femoral artery) showed 1-year patency rates of 75 per cent in common femoral artery grafts and 79 per cent in superficial femoral artery grafts (P = n.s.). These results suggest that the proximal superficial femoral artery is a safe inflow site for distal bypasses.

Duplex ultrasound monitoring of arterial grafts: prospective evaluation in conjunction with ankle pressure indices after femorodistal bypass.

Duplex scanning and ankle brachial pressure indices have been used to objectively assess 94 femoro-distal bypass grafts 4-8 weeks postoperatively. Twenty grafts were occluded. Of the 74 patent grafts, three distinct groups could be identified on the basis of the non-invasive examination. Group 1. Patent grafts with no evidence of haemodynamically significant disease. Group 2. Patent grafts with localised disease. Group 3. Patent: haemodynamically failed grafts. Ankle brachial pressure indices alone could not differentiate between occluded grafts and grafts that were patent: haemodynamically failed (group 3), or adequately separate between grafts in groups 1 and 2. Duplex scanning when combined with pressure indices identified patent grafts "at risk" due to the presence of haemodynamically significant disease. Life table analysis demonstrated appreciable differences in event free survival between group 1 grafts and "at risk" grafts (groups 2 and 3). Duplex scanning is ideal for regular postoperative surveillance and complements the use of ankle brachial pressure indices in the follow-up of femoro-distal grafts.

Duplex ultrasound assessment of femorodistal grafts: correlation with angiography.

Fifty-eight grafts have been assessed using duplex scanning and ankle brachial pressure indices. This assessment is compared with the findings by angiography. Eighteen grafts were occluded and 40 patent. Duplex scanning defined graft status with a greater accuracy than pressure indices. Pressure indices alone would not differentiate "satisfactory" grafts from those with localised, haemodynamically significant disease. Only 55% of those grafts with localised stenoses demonstrated a fall of greater than 0.2 in ankle brachial pressure index after exercise. When the information obtained using pressure indices and duplex scanning was combined non-invasive assessment had a sensitivity of 86% and specificity of 94% for detection of localised, haemodynamically significant disease in patent grafts. Haemodynamically significant disease, as defined by angiography, can be detected and localised with duplex scanning complementing the use of pressure indices in graft assessment.

Salvage autotransfusion in aortic surgery: initial studies using a disposable reservoir.

Transmission of disease by allogeneic transfusion can be avoided using several techniques by which a patient receives his own blood. Sixty patients undergoing aortic surgery consented to salvage interoperative autotransfusion. A mean of 895 ml shed blood was reinfused under full heparinization, representing 12-74 per cent of total blood loss. Bank blood requirements fell from 4.9 units to 3.4. No important haematological or clinical complications were noted (including coagulation studies) but haemolysis was detected 4 h postoperatively by plasma haemoglobin levels of 0.05 +/- 0.03 g/dl. This preliminary study confirms the applicability of salvage autotransfusion during elective vascular surgery by demonstrating an appreciable saving in bank blood transfusion (70 per cent).

The success of in situ vein grafting: early results in comparison with the reversed vein technique.

In a 6-year retrospective analysis of 341 consecutive femorodistal autogenous vein bypasses, results from 104 in situ veins (IS) were compared with 209 reversed veins (RV). The groups were comparable for age, sex, diabetes, indication for surgery and calf vessel run-off, but a significantly higher proportion of the in situ group had a lower distal anastomosis (16% IS, 6% RV, chi 2 = 7.1 P less than 0.01). Overall, operative mortality was 2% and early graft failure was similar in both groups (11% IS, 12% RV, P = NS). Cumulative graft patency rates were 74% IS, 79% RV at one year and 71% IS, 71% RV (P = NS) at three years. Cumulative limb survival rates were 81% IS, 85% RV at one year and 79% IS, 81% RV [P = NS) at 3 years. These results demonstrate that the in situ technique has been used in a wider variety of patients and yielded similar early and intermediate term results to reversed vein.

Random control trial of a short course of aspirin and dipyridamole (Persantin) for femorodistal grafts.

The effect of a short course of anti-platelet agents, started preoperatively, on the patency of femorodistal bypass grafts is unknown. One hundred and forty-eight such grafts were randomized to act as controls or to receive dipyridamole 200 mg b.d. for 48 h pre-operatively and dipyridamole 200 mg b.d. with aspirin 300 mg daily for 6 weeks after surgery. Patients were well-matched and the mean pre-operative pressure index of 0.37 rose to 0.78 during the first postoperative week. No deaths were attributable to the treatment. Ninety-three grafts were autogenous vein and the remainder were prosthetic (GORE-TEX (PTFE), human umbilical vein or externally supported Dacron). At 1 year autogenous vein cumulative patency was 75 per cent. Overall results showed higher patency in the treated group (P = 0.012) which was entirely accounted for by the difference between prosthetic dipyridamole and aspirin group (85 per cent patency) and prosthetic control groups (53 per cent patency, P = 0.005) and arose during the first postoperative month. There were 11 deaths and 8 amputations in the dipyridamole and aspirin group and 8 deaths and 12 amputations in the control group. It is concluded that a six week perioperative course of dipyridamole and aspirin allows the patency of prosthetic femorodistal bypass to approach that of autogenous vein, and the regimen therefore is recommended for patients who may require a prosthetic graft.