Evaluation of a computerised test for the assessment of peripheral vascular disease.

This paper reports a study carried out in 200 patients to assess the effectiveness of a clinical vascular laboratory in the routine assessment of peripheral vascular disease (PVD) of the lower limb. Laboratory assessments involved a computer based hierarchical testing system incorporating pedal pressure indices, maximum walking distances and principal component analysis of the common femoral artery blood velocity waveform. The study fell into two parts. In the first, the laboratory assessments of 100 patients referred six years ago were compared retrospectively with their eventual clinical outcome. In this comparison, the laboratory provided a "diagnosis" which was 79% correct. In the second, a double blind prospective study was carried out in 100 patients to compare the vascular laboratory "diagnosis" with the diagnosis and prognosis of a skilled clinician, the outcome being compared one year after the initial assessment. In this study the laboratory proved to be correct in 78% of cases, the clinician in 70%. With a slightly modified computer protocol for the non vascular diagnosis, the computer would have been correct in 85% of cases. This test provides a quantitative and objective assessment of PVD which can assist in the patient's clinical diagnosis and management.

An epidemiological survey of Raynaud's phenomenon.

A questionnaire was sent to 1000 patients with Raynaud's phenomenon (RP) and an equal number of controls in order to accumulate one of the largest patient data banks currently available. Five-hundred and seventy-one correctly completed paired returns were processed so as to investigate the association between Raynaud's phenomenon and other factors suspected of influencing the condition. The involvement of female sex hormones in RP was indicated by the predominance of women (93%), a 6% (P less than 0.02) higher incidence of infertility and the influence of menstruation (15%), the menopause (73%) and pregnancy (53%) on symptoms. Patients with scleroderma had a 5% higher incidence of stillbirths. A familial predisposition for RP was noted dependent on age at onset of symptoms (age less than 30, 14% greater than 30, 4.9%). The Raynaud's group overall had a significantly higher percentage who had been treated for migraine (7% higher P less than 0.01), angina (3% higher P less than 0.05) and duodenal ulcer (3% higher P less than 0.001). Of the respondents who had undergone sympathectomy (n = 140, 24.5% of the total), 18.6% claimed lasting benefit and 66.4% claimed no benefit after one year. The mean age at sympathectomy was 38.6 years (S.D. +/- 13 range 14-78) with a mean age of start of symptoms of 29.2 years (S.D. +/- 14.7, range 0-70). There was no significant difference between the effects of sympathectomy on those patients with and those without associated conditions.

Thermal entrainment methods for studying Raynaud's phenomenon.

Entrainment occurs when an externally applied periodic temperature stimulus forces the peripheral bloodflow component of thermoregulation to oscillate at the same frequency. This phenomenon can be demonstrated using frequency transforms to analyse the spectral content of the bloodflow, and can be used as a diagnostic test for Raynaud's phenomenon. Correlations were performed between the clinical diagnosis and the objective tests. The average inter-clinical correlation coefficient was r = 0.66. When the average clinical diagnosis was compared with a combination of thermal entrainment and digital patency testing the correlation coefficient rose to r = 0.68. These results highlight the difficulties encountered when assessing patients with Raynaud's phenomenon and the necessity of applying both physiological and clinical techniques.

Ruptured abdominal aortic aneurysm in Marfan's syndrome.

A rare case of ruptured abdominal aortic aneurysm in Marfan's syndrome is described. The patient was treated successfully with a straight aortic tube graft. Histology of the aneurysm wall showed changes typical of cystic medial necrosis.

The effect of adjuvant oxygen therapy on transcutaneous pO2 and healing in the below-knee amputee.

The effects on tissue oxygenation of postoperative adjuvant oxygen have been studied in a group of 20 patients undergoing below-knee (BK) amputation for vascular disease. Ten patients received no therapy, the remainder receiving 28% oxygen for 48 hours following surgery. The results showed that the transcutaneous pO2 in the amputation flaps fell significantly by some 20 mmHg (p less than 0.01) following surgery and that this fall was prevented by the use of adjuvant oxygen. The fall was not observed in the non-amputated limbs. TcpO2 took almost two weeks to reach its pre-operative levels in the amputated limbs. The effect on stump healing of adjuvant oxygen therapy was investigated in a randomized controlled trial in a series of 39 patients undergoing BK amputation. There were 22 patients in the control (untreated) group and 17 in the treated group (adjuvant oxygen for 48 hours). In the treated group 14 patients healed primarily and three amputations failed. In the untreated group 14 limbs healed primarily, one secondarily and there were 7 failures. The pre-operative transcutaneous values in the stumps which failed (26 mmHg +/- 14) was significantly lower (p less than 0.005) than in those which healed (40 mmHg +/- 9). The mean pre-operative TcpO2 in the patients in whom healing occurred in the treated group (35 mmHg +/- 10) was significantly lower (p less than 0.001) than the mean pressure observed in the untreated group (44 mmHg +/- 9).

Raynaud's phenomenon: a review.

Raynaud's phenomenon is a final result of many disease processes and is rarely a primary dysfunction and more an autoimmune phenomenon. It seems to be the result of a failure of vasodilatation than a sympathetic overactivity. Digital arteries are affected in only 40%, more often the fault is at the arteriolar and capillary level. The controlling mechanism of small vessels seems intact but the role of central versus peripheral factors is unresolved. The method of thermal entrainment has shown the action of sex hormones on vascular control especially at the time of ovulation. Heredity is a major factor in aetiology, myxoedema is common (16%). The role of prostaglandin metabolism is not clear. Platelets are hyperactive, blood viscosity is raised and red cells more rigid than normal. Sympathectomy fails in 81% of cases.

Improved survival of the diabetic foot: the role of a specialized foot clinic.

A specialized foot clinic for diabetic patients has made a detailed analysis of the presentation of diabetic foot ulcers and from this a new, organised approach to treatment has been derived. Over three years it has achieved a high rate of ulcer healing and reduced the number of major amputations. It has brought together the skills of chiropodist, shoe-fitter, nurse, physician and surgeon to manage the distinctive lesions of the neuropathic and ischaemic diabetic foot. The neuropathic ulcer was invariably associated with callus, whereas the ischaemic ulcer presented as areas of necrosis often from localised pressure of tight shoes. Essential aspects of management are specially constructed shoes, intensive chiropody and precise antibiotic treatment. Healing was achieved in 204 out of 238 (86 per cent) neuropathic ulcers and 107 out of 148 (72 per cent) ischaemic ulcers. Relapse rate in special shoes was 26 per cent compared with 83 per cent who preferred to wear their own shoes. In the two years before the establishment of the clinic, there were 11 and 12 major amputations yearly. This rate has now been reduced to seven, seven and five amputations yearly.

Chemical lumbar sympathectomy for ischemic rest pain. A randomized, prospective controlled clinical trial.

The results of a randomized, controlled, prospective double-blind trial of phenol chemical sympathectomy against placebo bupivacaine injection in 41 limbs (24 treatment and 17 control) have been presented. Ablation of the skin potential response was used as an indication of successful sympathectomy. Rest pain was relieved in 83.5 percent of patients at 1 week with a placebo response of 23.5 percent (chi-square test, p less than 0.002). Sixty-six percent of patients remained free from rest pain at 6 months (chi-square test, p less than 0.02). The ankle-brachial systolic pressure index and resting and peak (reactive hyperemic) blood flows were measured in the foot; there was no demonstrable improvement in these hemodynamic factors. Chemical sympathectomy in these circumstances is probably acting as a pain-relieving injection but nevertheless produces useful remission of rest pain in these inoperable but otherwise relatively stable patients. It can also be employed while relevant investigations are carried out before direct arterial surgery.

Reflex vascular responses in the finger to contralateral thermal stimuli during the normal menstrual cycle: a hormonal basis to Raynaud's phenomenon?

1. Raynaud's phenomenon is a condition which primarily affects women and it must be assumed that hormonal influences are responsible. 2. To further investigate this assumption the effect of cyclic sex hormone fluctuations on the digital vascular reactivity of ten normal young women was studied by the diagnostic techniques of thermal entrainment of finger blood flow and Doppler ultrasound mapping of the digital arteries. 3. In the immediate pre-ovulatory period the results obtained were comparable with those found in patients with established Raynaud's phenomenon, suggesting that oestrogen has an important modulating effect in vivo on reflex peripheral vasomotor responses to thermal stimuli. 4. 'Primary' Raynaud's phenomenon may represent an exaggerated response to oestrogen.

The computer as a tool in the diagnosis and treatment of peripheral vascular disease.

The application of a mini computer to a routine diagnostic vascular laboratory has been assessed in over 4,500 patients over a period of 5 years. The laboratory functions to provide diagnosis of peripheral vascular disease. The computer functions are: scientific, in which it is used for modelling the arterial system and for applying diagnostic algorithms using haemodynamic signals re-input data, data base management, in which it is used to store clinical histories, the results of haemodynamic tests, and data for reconstructive surgery, and administrative, in which it is used for laboratory booking, report generation and management and workload statistics.

Thermal entrainment and human ovulation.

The changes in the peripheral vascular response to temperature have been studied for ten menstrual cycles by calculating thermal entertainment levels. The entrainment levels exhibited peaks at around the time of ovulation, a result which we believe is due to the fluctuating levels of the hormones oestrogen and progesterone in the blood. An attempt has been made to explain the influence of these hormones on the vasomotor control system and where interactions may occur.