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Biomedical subjects

A D Fox

Publications and source records attributed to A D Fox.

At least 19 recordsLinked to original sources

Acute upper limb ischemia: a complication of coronary artery bypass grafting.

We present the case of a patient with acute upper limb ischemia after radial artery harvest for coronary artery bypass grafting. This occurred despite adequate preoperative and intraoperative assessment with the Allen test, hand-held Doppler and radial artery backbleeding. A successful outcome was achieved by performing brachioradial bypass grafting using reversed cephalic vein.

Acute Disease↗

Experience with heparin-bonded collagen-coated grafts for infrainguinal bypass.

The perfect conduit for infrainguinal reconstructive surgery does not exist. When autologous vein is not available, then a prosthetic graft must be used. The use of a heparin-bonded graft has the theoretical advantage of reducing smooth muscle cell proliferation and thrombus formation, thereby reducing occlusion rates. The application of a collagen layer to the external surface of the graft serves to reduce transfabric haemorrhage. Forty-six patients underwent 47 infrainguinal reconstructions using heparin-bonded collagen-coated Dacron grafts over a 4-year period. Twenty grafts were for disabling claudication and 27 for critical ischaemia. Twenty-two grafts were to the above knee popliteal artery (47%), 10 to the below knee popliteal (21%) and 15 to one of the crural vessels (32%). There was a cumulative patency at 4 years of 69% for the above knee grafts, and 30-month patency of 58% and 45% for the below knee and crural grafts, respectively. There were three deaths over the study period and eight patients required major amputations.

Aged↗

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.

Acute Disease↗

Age-related outcome for peripheral thrombolysis.

OBJECTIVES: To investigate the age-related outcome of peripheral thrombolysis and determine for which patient group this treatment is worthwhile. DESIGN AND METHODS: A combined retrospective and prospective analysis of consecutive patients undergoing thrombolysis for acute lower-limb ischaemia was made with respect to age-related outcome and other risk factors. RESULTS: One hundred and two patients underwent thrombolysis for acute limb ischaemia. In the under 60 age group there was a 40% amputation rate. Seventy-three per cent of this group smoked. In the over 80 age group, the amputation rate was 15% and only 8% were smokers. CONCLUSION: Advancing age is not an adverse risk factor for thrombolysis which appears to be safe and effective in this patient group. There is a high incidence of smoking in the younger age group (< 60 years), in whom failed thrombolysis frequently leads to amputation.

Acute Disease↗

The results of thoracoscopic sympathetic trunk transection for palmar hyperhidrosis and sympathetic ganglionectomy for axillary hyperhidrosis.

OBJECTIVES: To review our total experience of thoracoscopic sympathetic trunk transection for the treatment of palmar hyperhidrosis and second and third thoracic sympathetic ganglionectomy for axillary hyperhidrosis. DESIGN: Longitudinal cohort study following up consecutive patients for 0.3 to 5.5 years. SUBJECTS: Fifty-four consecutive patients undergoing thoracoscopic sympathectomy for hyperhidrosis. METHODS: Prospective evaluation of immediate technical success, complications, late recurrence of hyperhidrosis and patient acceptability. RESULTS: 100% initial cure for palmar hyperhidrosis, 91% of sympathetic ganglionectomies for axillary hyperhidrosis were technically successful and initially curative. Compensatory sweating 44% patients, most severe after bilateral sympathetic ganglionectomy. Complications occurred in 14% patients, all resolving without further intervention. There were no cases of Horner's syndrome. 13% patients reported a return of some palmar sweating. 5.4% patients developed recurrent palmar hyperhidrosis at 6, 15 and 21 months postoperatively. CONCLUSION: Transection of the sympathetic trunk between the first and second thoracic sympathetic ganglia initially cures 100% of patients treated primarily for palmar hyperhidrosis. Technically successful 2nd and 3rd thoracic sympathetic ganglionectomy initially cures 100% of patients with axillary hyperhidrosis. Compensatory sweating is common after bilateral sympathectomy. Recurrent palmar hyperhidrosis occurs in 5.4% of cases, but can be cured by a second thoracoscopic sympathectomy. Horner's syndrome is an avoidable complication of thoracoscopic sympathectomy.

Adolescent↗

Full-dose and half-dose Klean Prep produce clearer images with iliac duplex examination than picolax.

OBJECTIVES: Iso-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. DESIGN: Prospective study comparing clarity of duplex examination after three different bowel preparation regimes with that after 12 h starvation. MATERIALS AND METHODS: Thirty 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. RESULTS: Both 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. CONCLUSION: Klean Prep significantly improves the image obtained by iliac duplex examination; Picolax does not. Half-dose Klean Prep is an acceptable preparation to patients.

Aged↗

Photoplethysmography can replace hand-held Doppler in the measurement of ankle/brachial indices.

Ankle/brachial pressure index (ABPI) using hand-held Doppler and sphygmomanometer is a standard assessment for patients with peripheral arterial occlusive disease (PAOD). Good Doppler technique is difficult to master and so we investigated replacing Doppler with photoplethysmography (PPG). Two investigators examined 52 legs in 32 vascular patients. Both used standard sphygmomanometer cuff occlusion. Restoration of flow was detected by either an 8 MHz Doppler ultrasound probe or a PPG transmitter/receiver on index finger or great toe. Doppler-derived ABPIs were compared with PPG-derived ABPIs. Excellent correlation was found between both indices (correlation coefficient 0.875). Four lower limbs had unrecordable PPG traces, one also having an unrecordable Doppler signal. Excluding these four patients, the correlation coefficient rose to 0.975. PPG placed on the pulp of a digit can replace the hand-held Doppler in measuring ABPIs.

Ankle↗

Career aspirations and expectations of vascular trainees in 1996. The Rouleaux Club.

Sub-specialisation within general surgery has now become accepted as part of surgical training and consultant posts are being increasingly advertised for surgeons with a special interest. Transplantation surgery is currently losing trainees and proposals have been made to combine vascular and transplant surgery to a greater or lesser degree. The Rouleaux Club is a society for junior vascular surgeons in Great Britain and Ireland. Questionnaires were sent to 78 non-consultant members in July 1996 and 67 were returned and analysed. A reasonable cross-section of all training grades was obtained. Of this number 44 (65.7 per cent) did not want to spend any period of their higher surgical training in full-time transplantation training, although 32 (47.8 per cent) would accept some time in transplantation training if it were combined with another surgical specialty. Training in vascular access work was welcomed by 51 (76.1 per cent) but this contrasts with 40 (59.7 per cent) who would not want to offer this as a service once appointed to consultancy. Almost all of the trainees (60/64 = 93.8 per cent) ideally wanted to be appointed to consultant posts with > 50 per cent commitment to vascular surgery and most thought that they would realistically get such positions. Most trainees ideally wanted consultancies in academic/ university departments or teaching hospitals but many thought that in reality they would be appointed to posts in district general hospitals.

Attitude of Health Personnel↗

Comparison of magnetic resonance imaging measurements of abdominal aortic aneurysms with measurements obtained by other imaging techniques and intraoperative measurements: possible implications for endovascular grafting.

PURPOSE: Abdominal aortic aneurysm morphologic evaluation with conventional imaging techniques is inadequate when endovascular repair is being contemplated. This study has addressed the problem with magnetic resonance imaging (MRI). METHODS: Twenty patients (14 men, 6 women) with a median age of 73 years were recruited and assessed according to current endovascular graft selection criteria. Thirteen patients subsequently underwent open aneurysmorrhaphy, and the intraoperative parameters have been compared with those of duplex ultrasonography and MRI. RESULTS: No significant difference was demonstrated in the diameter of the infrarenal neck among ultrasonography, MRI, and intraoperative findings (p > 0.05, Mann Whitney U Test) and also during assessment of infrarenal neck length; however, duplex sonography accurately defined the renal ostia in only five cases. MRI visualized 38 of 40 renal arteries. Distal aortic involvement (cuff diameter and length) and the length and diameter of the common iliac arteries were accurately determined by MRI in all cases, and no significant difference was demonstrated with the intraoperative findings. Comparison of the intraoperative and MRI aneurysm lengths suggested a slight trend of overestimation by MRI resulting from angulation of the aneurysm, but this figure did not reach statistical significance. Only two patients met the current criteria for endoluminal straight grafting. CONCLUSIONS: Both MRI and duplex sonography accurately predicted aortic morphologic characteristics; however, MRI provided the most comprehensive anatomic picture for patient selection and should be considered the nonionizing imaging modality of choice when an endovascular repair is being contemplated.

Aged↗

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

OBJECTIVES: To 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). DESIGN: Prospective study. MATERIALS AND METHODS: 50 consecutive patients undergoing carotid endarterectomy were investigated. Follow-up was performed at 6 weeks using duplex scanning and clinical evaluation. RESULTS: Significant 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. CONCLUSIONS: Duplex 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.

Aged↗

Peroperative cholangiography through the gallbladder (cholecystocholangiography) during laparoscopic cholecystectomy.

The indications and best technique for peroperative cholangiography during laparoscopic cholecystectomy remain unclear, but the operation has been associated with an increased use of preoperative endoscopic retrograde cholangiography. Cystic duct cholangiography, particularly in the hands of the trainee, can be time consuming, and bile duct injury may be caused by attempts to cannulate the cystic duct. This study analyses 113 consecutive patients undergoing peroperative cholangiography through the gallbladder, or cholecystocholangiography. It was successful in 92 (81.4%) patients, the procedure adding less than 10 min to the operating time. There were no cholangiogram-related complications. Common anatomical variations included both short and particularly wide cystic ducts. This information helps to minimize the risk of damage to the common bile duct. This study demonstrates that cholecystocholangiography is a safe, simple, and effective alternative to cystic duct cholangiography with virtually no "learning curve." It provides a "road-map" of biliary anatomy and identifies common bile duct stones prior to the commencement of dissection. Unsuccessful cholecystocholangiography does not preclude the use of cystic duct cholangiography later in the operation. Difficult anatomy is demonstrated prior to dissection. When unsuspected bile duct calculi necessitate open exploration, further laparoscopic dissection is avoided.

Adult↗