Subintimal angioplasty of isolated infragenicular vessels in lower limb ischemia: long-term results

PURPOSE

To assess the outcome of subintimal angioplasty in treating isolated infragenicular arterial disease in patients with severe lower limb ischemia.

METHODS

A retrospective study reviewed 67 consecutive patients (39 men; mean age 76 years, range 41-96) who underwent infragenicular subintimal angioplasty between March 1997 and May 2000 for ischemia in 70 limbs. The median length of occlusion was 6 cm [corrected] (range 1-10) in the below-knee popliteal arteries, 4 cm [corrected] (range 1-4) in the tibioperoneal trunk, 21 cm [corrected] (range 1-35) in the anterior tibial artery, 10 (1-30) in the posterior tibial artery, and 5 (range 1-20) in the peroneal artery.

RESULTS

The technical and clinical success rates were 86% and 80%, respectively. In the 10 (14%) patients with a technical failure, 3 underwent successful bypass, 4 had an amputation, 1 had a lumbar sympathectomy, and 2 were treated conservatively. Of the 4 (6%) limbs that did not achieve clinical success, 2 patients required femorodistal bypass and their ulcers improved; in the other 2, ulcerations did not heal completely. The cumulative limb salvage rate and freedom from critical limb ischemia (CLI) quantified by Kaplan-Meier life-table analysis were 94% and 84% at 36 months. Mortality rates were 19% at 1 year, 43% at 2 years, and 51% at 3 years. In a subgroup analysis, the rate of CLI was significantly lower in nondiabetics (4%) and than in diabetics (24%, p=0.02), but neither survival nor amputation rates were significantly different.

CONCLUSIONS

Subintimal angioplasty is a safe and effective procedure for treating isolated crural vessels in patients with severe lower limb ischemia.

Routine or selective carotid artery shunting for carotid endarterectomy (and different methods of monitoring in selective shunting)

BACKGROUND

Temporary interruption of cerebral blood flow during carotid endarterectomy can be avoided by using a shunt across the clamped section of the carotid artery. This may improve outcome.

OBJECTIVES

The objective of this review was to assess the effect of routine versus selective, or never, shunting during carotid endarterectomy, and to assess the best method for selecting patients for shunting.

SEARCH STRATEGY

For the original review the authors searched the Cochrane Stroke Group trials register, Medline (1966 to 1994), Embase (1980 to 1995) and Index to Scientific and Technical Proceedings (1980 to 1994). They also hand searched Annals of Surgery (1981 to 1995), British Journal of Surgery (1985 to 1995), European Journal of Vascular Surgery (1988 to 1995) and World Journal of Surgery (1978 to 1995). For the updated review, for the dates January 1994 - December 2000 we: 1. Repeated all these searches performed for the original review and developed more comprehensive search strategies for Medline and Embase. The Cochrane Stroke Group Trials Register was last searched in May 2001. 2. Hand searched the Journal of Vascular Surgery, Stroke, Annals of Vascular Surgery, American Journal of Surgery and Cardiovascular Surgery. 3. Hand searched the abstracts from the International Stroke Conference, AGM of the Vascular Surgical Society (UK), AGM of the Association of Surgeons of Great Britain and Ireland and the Annual Meeting of the Society for Vascular Surgery (USA). 4. Searched reference lists from all relevant trials All the authors of studies included in the initial review, and other authors known to have published relevant work, were contacted requesting information about further published or unpublished data.

SELECTION CRITERIA

Randomised and quasi-randomised trials of routine shunting compared with no shunting or selective shunting, and trials that compared different shunting policies in patients undergoing carotid endarterectomy.

DATA COLLECTION AND ANALYSIS

For the original review two reviewers independently performed the searches and applied the inclusion criteria. The data were extracted by one reviewer and double-checked. Trial quality was assessed. During the update, two reviewers independently performed the searches and applied the inclusion criteria. No new relevant randomised controlled trials were found.

MAIN RESULTS

Despite recommendation from the original review that further studies were required, no new trials of adequate quality and fitting the inclusion criteria were found. The initial review included three trials. Two trials involving 590 patients compared routine shunting with no shunting. The other trial involving 131 patients compared shunting with a combination of electroencephalographic and carotid pressure measurement, with shunting by carotid pressure measurement alone. Allocation was adequately concealed in one trial, and one trial was quasi-randomised. Analysis was by intention-to-treat where possible. For routine versus no shunting, there was no significant difference in the rate of all stroke, ipsilateral stroke or death up to 30 days after surgery, although data were limited. There was no significant difference between the risk of ipsilateral stroke in patients selected for shunting with the combination of electroencephalographic and carotid pressure assessment compared to pressure assessment alone, although again the data were limited.

REVIEWER'S CONCLUSIONS

When first published in 1995, this review concluded that the data available were too limited to either support or refute the use of routine or selective shunting in carotid endarterectomy. It was suggested that large scale randomised trials using no shunting as the control group were required. No one method of monitoring in selective shunting has been shown to produce better outcomes. No further prospective randomised or quasi-randomised trials have been performed since then and the conclusions therefore remain unchanged.

7-Methoxybenzofuran-4-carboxamides as PDE 4 inhibitors: a potential treatment for asthma

The synthesis and pharmacological profile of a novel series of 7-methoxybenzofuran-4-carboxamides is described. Some of these compounds were found to be potent inhibitors of phosphodiesterase type 4 (PDE4).

Three years' experience of collaborative care pathways on a maxillofacial ward

Collaborative care pathways (CCPs) provide a framework for multidisciplinary patient care. They provide guidelines and a mechanism for audit, and were first introduced at the Regional Unit, Walton Hospital, Liverpool, in November 1994. They have been designed for many surgical groups. Between August 1996 and 31 July 1997, 955 patients were admitted on to the nine established pathways: fractured mandible (n=213), fractured zygoma (n=117), minor oral surgery (n=244), abscess (n=18), examination under anaesthesia (n=73), nasal surgery (n=73), osteotomy (n=80), salivary (n=63), and temporomandibular joint (n=74). The purpose of this article is to report the introduction of CCP in a maxillofacial ward and give results from a one-year audit. CCP have proved to be an extremely useful tool and have several advantages over traditional documentation. They are more accurate, easily computerized, and facilitate audit. They promote the development of guidelines and standardized perioperative care, and this in turn facilitates training and raises standards of care.

A cross-cultural consumer-based decision aid for screening mammography

BACKGROUND

"Women should have mammograms" is the usual perspective of educational interventions about screening. The perspective that "women should be informed" about potential risks and benefits so they can make value- and evidence-integrated personal decisions has recently been advocated. However, this perspective has not previously been operationalized. We developed an evidence-based cross-cultural mammography decision aid (MDA), for European American and Mexican American women who are 50-70 years old, at average risk of breast cancer, of varying educational levels, and English- or Spanish-speaking.

METHODS

MDA development included: (1) content development by a multidisciplinary team and lay women and (2) testing for validity and reliability. Four parts include: (1) introduction; (2) information about logistics (cost, time, discomfort) and risks (sequelae of false-positive or negative results; (3) probability of developing breast cancer; and (4) benefit of mammography regarding breast cancer outcomes (e.g., death and recurrence). We assessed reliability (stability of decisions with the same information) after 1-2 weeks. We assessed validity (comprehension of information) quantitatively (probabilities were changed to see whether preferences changed predictably) and qualitatively (focus groups, standardized probes for comprehension). Subjects were a convenience sample of 49 European American (50-81 years old) and 54 Mexican American (49-89 years old) women from administrative staff at a medical school, the waiting room of an indigent primary care clinic, and a community center.

RESULTS

Reliability was 100%. In quantitative validity testing, 22 of 28 women (89%) changed preference as predicted with changed probabilities. Comprehension was confirmed qualitatively in all phases of testing with both Spanish and English versions.

CONCLUSION

The decision aid is valid and reliable in English and Spanish for southwestern Mexican American and European American women at average risk of breast cancer, including those of low educational levels.

Patches of different types for carotid patch angioplasty

BACKGROUND

Some surgeons who use carotid patching favour using the saphenous vein, whilst others favour synthetic materials.

OBJECTIVES

The objective of this review was to assess the effect of different materials for carotid patch angioplasty.

SEARCH STRATEGY

We searched the Cochrane Stroke Group trials register, Medline (1966 to 1995), Embase (1980 to 1995) and Index to scientific and technical proceedings (1980 to 1994). We handsearched Annals of Surgery (1981 to 1995), British Journal of Surgery (1985 to 1995), European Journal of Vascular and Endovascular Surgery (1987 to 1995) and World Journal of Surgery (1978 to 1995).

SELECTION CRITERIA

Randomised trials comparing one type of carotid patch with another for carotid endarterectomy.

DATA COLLECTION AND ANALYSIS

One reviewer applied the inclusion criteria and extracted the data. Trial quality was assessed.

MAIN RESULTS

Three trials involving 326 operations were included. The trials compared saphenous vein patches with synthetic polytetrafluroethylene patches. Allocation was not adequately concealed in two trials, and only one followed-up patients until hospital discharge. Intention-to-treat analysis was only possible for the latter trial. In all trials a patient could be randomised twice and have each carotid artery randomised to different treatment groups. One trial was excluded from the analyses of death and any stroke because it was not possible to clarify how many patients, rather than arteries, were allocated to each treatment. There were too few events to determine whether there was any difference between the patch materials for perioperative stroke, death and arterial complications. During longterm follow-up for more than one year, no difference was shown between the two types of patch for the risk of stroke, death, or arterial restenosis. However, the number of events was small. Based on 236 patients in two trials, there were significantly fewer pseudoaneurysms associated with synthetic patches (odds ratio 0.15, 95% confidence interval 0.05 to 0.44).

REVIEWER'S CONCLUSIONS

There is not enough evidence to differentiate between venous and synthetic patches in carotid endarterectomy.

Patch angioplasty versus primary closure for carotid endarterectomy

BACKGROUND

Carotid patch angioplasty (with either a venous or a synthetic patch) may reduce the risk of carotid artery restenosis and subsequent ischaemic stroke.

OBJECTIVES

The objective of this review was to assess the effect of routine or selective carotid patch angioplasty compared to carotid endarterectomy with primary closure.

SEARCH STRATEGY

We searched the Cochrane Stroke Group trials register, Medline (1966 to 1995), Embase (1980 to 1995) and Index to Scientific and Technical Proceedings (1980 to 1994). We handsearched Annals of Surgery (1981 to 1995), British Journal of Surgery (1985 to 1995), European Journal of Vascular and Endovascular Surgery (1987 to 1995) and World Journal of Surgery (1978 to 1995).

SELECTION CRITERIA

Randomised trials comparing carotid patch angioplasty with primary closure in any patients undergoing carotid endarterectomy.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed eligibility, trial quality and extracted the data.

MAIN RESULTS

Six trials involving 794 patients and 882 operations were included. The quality of trials was generally poor. Follow-up varied from hospital discharge to five years. Carotid patch angioplasty showed a reduction in the risk of stroke of any type, ipsilateral stroke, and stroke or death, during the perioperative period and longterm follow-up. However, data were not available from all trials, the number of events was small and there was significant loss to follow-up. Patching appeared to reduce the risk of perioperative arterial occlusion (six trials, odds ratio 0.17, 95% confidence interval 0.06 to 0.46). Patching was also associated with decreased restenosis during longterm follow-up in five trials, (odds ratio 0.32, 95% confidence interval 0.19 to 0.53). However, these results are uncertain because of loss to follow-up and the small number of events. Very few arterial complications, including haemorrhage, infection, cranial nerve palsies and pseudo-aneurysm formation were recorded with either patch or primary closure.

REVIEWER'S CONCLUSIONS

Limited evidence suggests that carotid patch angioplasty may lower the risk of perioperative arterial occlusion and restenosis. It is unclear whether this reduces the risk of death or stroke.

Altered small artery morphology and reactivity in critical limb ischaemia

Although the pathophysiology of critical limb ischaemia is poorly understood, there is evidence that the condition of the small arteries may determine the outcome of revascularization procedures. This study was designed to investigate the effects of critical limb ischaemia on the structure and function of the small arteries in the leg. Small arteries (<500 microm) from proximal (non-ischaemic) and distal (ischaemic) sites were obtained from patients undergoing bypass surgery for critical limb ischaemia and mounted in a myograph. Reactivity and morphological measurements were carried out and compared with controls. Control vessels from the thigh and calf showed no difference in media to lumen ratio. However, a comparison of ischaemic and non-ischaemic vessels from the patients with critical limb ischaemia showed significant thinning of the ischaemic vessel wall. Contraction studies using noradrenaline and angiotensin II revealed a significant decrease in the response of ischaemic vessels compared with the non-ischaemic vessels from the same patient. Moreover, these differences in reactivity were still apparent after the responses were corrected for wall thickness. Endothelial function assessed using the endothelium-dependent agonists acetylcholine and bradykinin showed a significantly impaired relaxation response to acetylcholine but not to bradykinin in the ischaemic vessels, and acetylcholine-induced relaxation was not improved after incubation with indomethacin. There was no change in the response to the endothelium-independent cAMP-mediated vasodilator iloprost but a significant impairment to sodium nitroprusside which acts via cGMP. These results suggest that small arteries in critical limb ischaemia are altered in both structure and function, with vessel wall thinning and impaired responses to acetylcholine and sodium nitroprusside.

PDE4 inhibitors: new xanthine analogues

Novel xanthine analogues are described which are selective PDE4 inhibitors with improved therapeutic potential over theophylline.

Synthesis and evaluation of a novel series of phosphodiesterase IV inhibitors. A potential treatment for asthma

The synthesis and pharmacological profile of a novel series of potent and selective phosphodiesterase type IV (PDE IV) inhibitors is described.

Integration of environmental, agronomic, and economic aspects of fertilizer management

Nitrogen fertilization is a substantial source of nitrogen-containing trace gases that have both regional and global consequences. In the intensive wheat systems of Mexico, typical fertilization practices lead to extremely high fluxes of nitrous oxide (N2O) and nitric oxide (NO). In experiments, lower rates of nitrogen fertilizer, applied later in the crop cycle, reduced the loss of nitrogen without affecting yield and grain quality. Economic analyses projected this alternative practice to save 12 to 17 percent of after-tax profits. A knowledge-intensive approach to fertilizer management can substitute for higher levels of inputs, saving farmers money and reducing environmental costs.

A systematic review of the randomised trials of carotid patch angioplasty in carotid endarterectomy

OBJECTIVES

To determine whether patch angioplasty is more effective than primary closure in carotid endarterectomy, and whether one type of patch is better than another.

DESIGN

Systematic review of the randomised trials.

MATERIALS

Trials were identified from the Cochrane Stroke Review Group database plus additional handsearching, electronic searching, and personal contact.

METHODS

Two authors independently selected studies for inclusion and extracted details of trial quality and data on the following outcomes: any stroke; stroke ipsilateral to the operated artery; death; occlusion or restenosis, and other significant arterial complications. Meta-analysis of odds ratios (OR) was performed using the Peto method.

RESULTS

Six trials (882 operations) compared routine patching with primary closure. Routine patching was associated with significant reductions in the risks of ipsilateral stroke during the perioperative period (OR 0.34, 95% CI 0.15-0.76) and during long-term follow-up (OR 0.38, 95% CI 0.16-0.88). Significant reductions in the odds of any stroke, stroke or death, acute arterial occlusion and long-term restenosis were also found. However, these results were based on very small numbers of outcome events and may be biased by losses to follow-up and publication bias. Three trials (326 operations) compared the use of polytetrafluoroethylene patches with venous patches. There were too few events (strokes, deaths, arterial complications) to determine whether there were significant differences between the patch materials. Fewer pseudoaneurysms occurred in those who received synthetic patches but the clinical consequence of this was unclear.

CONCLUSIONS

Routine carotid patch angioplasty was associated with promising reductions in the risks of ipsilateral stroke and death, but the results should be interpreted cautiously because of the small number of outcome events, significant losses to follow-up, and poor trial methodology. Ideally, a large definitive trial should be performed. There is insufficient evidence to support the preferential use of one particular type of patch versus another.

The changing workload of a surgical unit with a vascular interest

OBJECTIVES

To examine the changing relationship between general and vascular surgical workload on a vascular "firm", over a 6-year period.

DESIGN

Retrospective review.

SETTING

Leicester Royal Infirmary and Professorial Surgical Unit, U.K. 1987-1992.

METHOD

Analysis of audit of all surgical admissions. Relation of vascular surgery to general surgery.

RESULTS

There has been a slight decrease (5%) in the number of general surgical elective admissions. Overall, the number of general surgical admissions, both elective and emergency, show a slight increase of about 3%. In contrast the number of vascular admissions increased by 42%. Of the general surgical procedures carried out 75.9% were either minor or intermediate, whereas 92.5% of vascular procedures were coded as major or higher. There has been a three times increase in the number of carotid endarterectomies, a similar increase in the number of the femorodistal bypass grafts and a halving of the number of major amputations. There has also been a five times increase in the number of angioplasties carried out.

CONCLUSIONS

Our figures show the progressive, rapid increase in vascular surgical workload, compared to general surgery, and the need for the continued expansion of vascular surgery as a speciality.

Detecting the early stages of osteomalacia with the intravenous vitamin D test

Studies of calcium levels in 400 elderly patients in a hospital geriatric unit showed that many patients (42 percent) had hypocalcemia when referred to the unit and that the incidence of hypocalcemia rises proportionately with advancing age; however, in men, the frequency decreases after age 90. Although hypocalcemia is caused by vitamin D deficiency in a number of patients, in most it is caused by malnutrition. The intravenous vitamin D tests is a simple and reliable procedure for differentiating hypocalcemia due to specific vitamin D deficiency from that due to other causes. We suggest that a 15 percent rise in the serum phosphate level after the intravenous administration of 40,000 units of vitamin D3 indicates the presenceof osteomalacia. Little is known about the sequence of development of detectable bone changes and disturbance of serum calcium, phosphate, and alkaline phosphatase levels in the natural course of osteomalacia. Early treatment of osteomalacia is simple and very rewarding. No effort should be spared in detecting it as soon as possible.

The objective measurement of mental performance in cerebrovascular disease. A double-blind controlled study, using a graded-release preparation of isoxsuprine

An automatically controlled learned task was used to assess objectively the mental performance of a number of geriatric patients with cerebrovascular disease. The effect on the performance of the patients during treatment with isoxsuprine hydrochloride in a sustained-release presentation ("Duvadilan Retard") was measured during a double-blind, placebo-controlled trial of sixteen weeks' duration. There was a significant difference in the improvement in performance between the treated and untreated groups; by the end of the trial, the treated group having statistically significantly better scores (P = 0.047 two-tailed tests).

Pulmonary function study in old age

A study was carried out in 100 patients aged between 70 and 90 years to investigate pathological and respiratory function changes in old age. Vitalograph and peak flow meter measurements were made, but blood gas analysis was only carried out in 6 patients in view of the technical difficulties. Analysis of the results showed that there was a definite, moderate, restrictive type of defect in pulmonary function in almost all the patients, in those with generalized senile changes as well as in those with a pathological condition. Blood gas analysis showed a minimum degree of alteration in oxygen tension and saturation with normal carbon dioxide tension.

Improved large-volume sampler for the collection of bacterial cells from aerosol

A modified large-volume sampler was demonstrated to be an efficient device for the collection of mono-disperse aerosols of rhodamine B and poly-disperse aerosols of bacterial cells. Absolute efficiency for collection of rhodamine B varied from 100% with 5-mum particles to about 70% with 0.5-mum particles. The sampler concentrated the particles from 950 liters of air into a flow of between 1 and 2 ml of collecting fluid per min. Spores of Bacillus subtilis var. niger were collected at an efficiency of about 82% compared to the collection in the standard AGI-30 sampler. In the most desirable collecting fluids tested, aerosolized cells of Serratia marcescens, Escherichia coli, and Aerobacter aerogenes were collected at comparative efficiencies of approximately 90, 80, and 90%, respectively. The modified sampler has practical application in the study of aerosol transmission of respiratory pathogens.

Induction of interferon by preparations of synthetic single-stranded RNA

A study was undertaken to help determine whether synthetic nonbase-paired, single-stranded RNA as well as synthetic base-paired, double-stranded RNA could induce interferon. Synthetic polyriboinosinic acid and polyribocytidylic acid induced interferon and interferon-like resistance in several different cell culture systems. However, in the intact rabbit only the most active preparations of single-stranded RNA induced circulating interferon when injected intravenously. The induced interferon and antiviral effect in tissue culture and animals was shown to have characteristics of the interferon system. Contamination of the single-stranded synthetic RNA materials by small amounts of base-paired, double-stranded RNA was ruled out by failure to find sufficient heterologous nucleic acid bases by differential activities of single-stranded and double-stranded RNA's in different cell systems and by failure to detect double-stranded RNA in poly-rI upon chromatography on benzoylated DEAE-cellulose.