M. Horrocks

Intraoperative duplex scanning as a means of quality control during carotid endarterectomy

OBJECTIVESnTo identify correctable technical errors following carotid endarterectomy using intraoperative colour duplex sonography (ATL, UM9, HDI). Results were compared with intraoperative flow measurements using an operative flow meter and with middle cerebral artery velocity measured by trans-cranial Doppler (TCD).nnnDESIGNnProspective study.nnnMATERIALS AND METHODSn50 consecutive patients undergoing carotid endarterectomy were investigated. Follow-up was performed at 6 weeks using duplex scanning and clinical evaluation.nnnRESULTSnSignificant intraoperative technical errors were detected in three patients and were re-explored. Two scans demonstrated kinking or pinching at the distal endarterectomy site requiring patch-plasty and the third revealed a large mass of intramural thrombus. A further 18 endarterectomies yielded 21 additional minor abnormalities.nnnCONCLUSIONSnDuplex sonography provides a sensitive intraoperative technique for detecting thrombus and technical errors. It yields both anatomic and hemodynamic details and is superior to intraoperative flow measurements and transcranial doppler.

The incorporation of a stent-graft into the porcine aorta and the inflammatory response to the endoprosthesis.

The fate of a non-sutured anastomosis and the inflammatory response to an endoprosthesis in a porcine aorta was determined. Self-expanding aorto-aortic endovascular prostheses were deployed into the infrarenal aorta of Large White pigs by the transfemoral route, in accordance with Home Office regulations. Animals were followed up at intervals to 1 year. The aortas were explanted and specimens were subjected to light microscopy. Thirteen animals, mean weight 103 kg, underwent placement of a prosthesis. There was early evidence of a neointima at 4 weeks and a well-developed neointima by 12 weeks, with complete incorporation of the endoprosthesis. The early acute inflammatory reaction seen at 4 weeks had become chronic by 12 and was largely absent by 26 weeks. There was no evidence of atypia. Complete incorporation of the non-sutured anastomosis is seen in this model. The acute inflammatory reaction to the prosthesis seen at 4 weeks had largely subsided by 26 weeks.

Evaluation of Distal Run-off before Femorodistal Bypass

The quality of distal run-off is one of the most important factors in determining outcome of femorodistal bypass. Accurate evaluation is important. Preoperative intra-arterial digital subtraction angiography and Doppler evaluation with pulse-generated augmentation of 90 patients who underwent femorodistal reconstruction were compared with postoperative angiography. Underestimation of distal run-off of the calf vessels occurred in 33% of cases by preoperative intra-arterial digital subtraction angiography. A below-knee pulse-generated run-off score of 3 or less was associated with a 12-month cumulative patency of 73% compared with 85% with a below-knee pulse-generated run-off score of 4 or more (P=0.079, log rank test; P =0.060, Wilcoxon signed rank test). The 12-month cumulative patency for grafts with a complete, incomplete and occluded arch as defined by pulse-generated run-off was 78, 90 and 38% respectively (P<0.0001 log rank and Wilcoxon signed rank tests). Preoperative evaluation of distal run-off before femorodistal bypass should not be based exclusively on intra-arterial digital subtraction angiography.

Vein graft factors in the outcome of femorodistal bypass

Various vein factors affect the outcome of femorodistal bypass using vein in the treatment of lower limb ischaemia. In this review, the effect of factors such as vein size, compliance and morphology are discussed.

Aortoiliac segment examination with colour flow duplex — a pilot study using klean prep. to improve the image quality

OBJECTIVESnCurrently colour flow Duplex examination of the iliac arteries is at best 84-92% sensitive. In an attempt to find a technique to improve on this sensitivity we have studied the effect of Klean Prep, an iso-osmotic bowel preparation, on the Duplex image and Doppler signal obtained when scanning iliac arteries.nnnMETHODSnTwenty iliac segments in 10 arteriopaths were scanned by a blinded observer, after either starving for 12 h or having Klean Prep bowel preparation. Grey scale image, colour mapping and Doppler signal to noise ratios were scored on a linear analogue system. Each patient was subsequently rescanned after the other method of preparation and was once again scored by a blinded observer. The two sets of scores were then compared.nnnRESULTSnWe found significant improvements in the linear analogue scoring of grey scale images, colour mapping and Doppler signal to noise ratios, when using Klean Prep as opposed to starving the patient prescan.nnnCONCLUSIONSnPreparing patients with Klean Prep before iliac Duplex examination improves the visualisation of these arteries.

Colour Duplex imaging through wound dressings.

Colour flow Duplex scanning is becoming the method of choice to determine patency and haemodynamic status in infrainguinal grafts and native arteries. Due to surgical wounds and ulcers, there are often dressings covering the leg above the vessel to be scanned. There is no data as to the effect of different wound dressings on colour flow Duplex signals. Ten normal superficial femoral arteries were scanned by a blinded operator. Initially the artery was visualised to assess the normal image produced for each artery on B-mode and colour flow ultrasound and a Doppler reading was taken. Then each of five commonly used dressings were applied to the skin above the artery, in random order and the blinded operator graded the signal produced on a linear analogue scale. Primapore, an absorbent material dressing and Spyroflex, a bilaminate membrane dressing, did not transmit ultra-sound at all. Granuflex extra thin allowed a clear B-mode image of each artery to be visualised and an adequate Doppler waveform to be obtained. However colour flow mapping was less than optimal although it was possible in each of the arteries. Opsite and Tegaderm, two thin membrane dressings allowed excellent B-mode and colour flow images, in addition to clear Doppler signals. In patients who require dressings and who may require colour flow Duplex scanning of vessels in the same area, we would suggest the use of a product that permits ultrasound transmission, thus saving the necessity of removing the dressing for the assessment.

FULL-DOSE AND HALF-DOSE KLEAN PREP PRODUCE CLEARER IMAGES WITH ILIAC DUPLEX EXAMINATION THAN PICOLAX

OBJECTIVESnIso-osmotic bowel preparation (Klean Prep) improves the accuracy of iliac duplex examination and reduces the time of each examination. Full-dose Klean Prep entails 4 l of fluid. We studied the effect of 2 l of Klean Prep (half-dose) and Picolax on image quality.nnnDESIGNnProspective study comparing clarity of duplex examination after three different bowel preparation regimes with that after 12 h starvation.nnnMATERIALS AND METHODSnThirty patients underwent iliac duplex examination after 12 h starvation. Scans were scored subjectively for grey scale and colour image quality, and Doppler signal-to-noise ratio. Patients were allocated blindly to: (a) full-dose Klean Prep, (b) half-dose Klean Prep, or (c) Picolax. After out-patient preparation, the scan was repeated and scored by the same observer, blinded to the preparation.nnnRESULTSnBoth full- and half-dose Klean Prep produced significant improvements in image quality for all three modalities; Picolax produced minimal change. There was minimal advantage of full-dose over half-dose Klean Prep. Patients preferred half-dose Klean Prep to full-dose.nnnCONCLUSIONnKlean Prep significantly improves the image obtained by iliac duplex examination; Picolax does not. Half-dose Klean Prep is an acceptable preparation to patients.

A Comparison of the Cost Effectiveness in Venous Ulcer Management Between Current Methods in the Community and Treatment with a Multilayer Compression Bandage System

Chronic venous ulceration is a debilitating and socially isolating disease affecting approximately 150,000 people at any one time in the United Kingdom [1], The prevalence increases with age and women are affected twice as commonly as men.