Interventions for great saphenous vein reflux: network meta-analysis of randomized clinical trials

BACKGROUND

A variety of endovascular and open surgical interventions exist to treat great saphenous vein reflux. However, comparisons of treatment outcomes have been inconsistent.

METHODS

A systematic review and network meta-analysis of RCTs was performed to compare rates of incomplete stripping or non-occlusion of the great saphenous vein with or without reflux (anatomical failure) at early, mid- and long-term follow-up; and secondary outcomes (reintervention and clinical recurrence) among intervention groups. The surface under the cumulative ranking curve (SUCRA) method was used to estimate the probability of the intervention with the lowest anatomical failure rates.

RESULTS

Some 72 RCTs were included. Comparisons of endothermal techniques with open surgery were mostly not significantly different, except for endovenous laser ablation (EVLA), which had higher long-term anatomical failure rates (pooled risk ratio (RR) 1.87, 95 per cent c.i. 1.14 to 3.07). Mechanochemical ablation had higher anatomical failure rates than radiofrequency ablation (RFA) (pooled RR 2.77, 1.38 to 5.53), and cyanoacrylate closure (CAC) had a RR 0.56 (0.34 to 0.93) times lower than either RFA or EVLA at the early term. Ultrasound-guided foam sclerotherapy had a higher risk of anatomical failure and reintervention than open surgery, with the lowest SUCRA value, and CAC was ranked first, third and first for best intervention for anatomical failure at early, mid and long term respectively. However, clinical recurrence rates were not significantly different between all comparisons.

CONCLUSION

Mechanochemical ablation and ultrasound-guided foam sclerotherapy performed poorly, with higher anatomical failure rates in the long term. The other treatment modalities had similar rates of anatomical failure in the short and mid term.

Peripheral artery disease in HIV-infected older adults on antiretroviral treatment in Thailand

OBJECTIVES

HIV infection has become a chronic disease requiring long-term treatment. Premature cardiovascular disease resulting from atherosclerosis in the HIV-infected population has been observed. We assessed the prevalence of peripheral artery disease (PAD), a common consequence of atherosclerosis, in HIV-infected patients aged ≥ 50 years receiving antiretroviral treatment (ART).

METHODS

This cross-sectional study was conducted in 12 community hospitals in Chiang Mai, Thailand. Inclusion criteria were as follows: (1) age ≥ 50 years, (2) positive HIV status, and (3) currently receiving ART. Age- and sex-matched hospital patients without documented HIV infection were enrolled as a comparison group. Clinical data were extracted from hospital records. Personal information and details of PAD-related symptoms were obtained through face-to-face interviews. The diagnosis of PAD was made using ankle-brachial index (ABI) measurement.

RESULTS

Seven hundred and twenty-four participants were enrolled in the study (362 HIV-infected patients and 362 patients in the comparison group). In the HIV-infected group, 43% were male; the mean (± standard deviation) age was 57.8 ± 5.6 years. The mean (± standard deviation) times from HIV diagnosis and ART initiation were 10.0 ± 4.3 and 8.6 ± 3.5 years, respectively. The prevalence of abnormal ABI (< 1.00) was significantly lower in the HIV-infected group than in the comparison group (20 versus 27%, respectively; P = 0.03), while that of PAD (ABI ≤ 0.90) was not significantly different between the two groups (5 and 7%, respectively). In the HIV-infected group, female sex and low body mass index were independently associated with abnormal ABI.

CONCLUSIONS

The prevalence of PAD when measured by ABI in HIV-infected older adults was relatively low. A follow-up study to determine the incidence of PAD and its persistence with time is warranted.

Prognostic Factors of Leg Amputation in Patients With Vascular Injury: A Systematic Review

Individual studies on the prognostic factors of leg amputation, due to vascular injury, have been small, and they have produced conflicting results. Reliable data are necessary so that surgery can be targeted more effectively. The authors carried out a systematic review from 1990 to 2002 to identify the high risk of patients to amputation. Meta-analysis was carried out. The authors found that patients with preoperative hypotension, popliteal artery injury, and associated bone and nerve injury had a significantly higher risk of leg amputation than those without these risk factors. Also, patients with postoperative infection had a higher chance of amputation than those without infection. This information is essential for an appropriate evaluation and the treatment of such patients.

A Hospital-Based Survey of Risk Factors for Diabetic Foot Ulceration in Northern Thailand

Ulceration of the foot is found more commonly in patients with diabetes mellitus than those without it. Foot ulcers affect the lives of patients in many ways, and though good care can be defined, loss of limb is a common occurrence in this patient group. Therefore, early detection of the foot at risk for foot ulceration is of paramount importance. Many risk factors for this type of ulcer have been previously reported such as neuropathy, deformity of the foot, arterial occlusion, and poor glycemic control. The authors conducted a hospital-based survey in patients attending a hospital diabetic clinic to establish a baseline database and found that the percentages of sensory neuropathy, history of claudication and poor glycemic control were 19.2%, 5.7%, and 79.7%, respectively. This suggests the need to establish good diabetic control and health education for our patient population.

The Development and Application of Diabetic Foot Protocol in Chiang Mai University Hospital With an Aim to Reduce Lower Extremity Amputation in Thai Population: A Preliminary Communication

Lower extremity amputation is a frequent complication of diabetes, and the authors' region did not have effective strategies to minimize it. From August 2005 to July 2006, a diabetic foot protocol (DFP) for out-patient management based on a multidisciplinary team approach was tried at the local teaching hospital. There are devices to reduce pressure and educate. After healing, there are custom fabricated orthoses and footwear, and monitoring of progressive ambulation. This report compares the amputation rate in patients receiving DFP care from August 2005 to July 2006 with those who had standard care from August 2003 to July 2005. Sixty-one and 110 diabetic foot ulcer patients received DFP and standard foot care, respectively. Their sex distribution and mean age were similar. The incidence of major amputations in the DFP and standard care groups was 3.3% and 13.6%, respectively (P = .03). The incidence of minor amputations in the DFP and standard care groups was 3.4% and 15.8%, respectively (P = .02). DFP was associated with improved diabetic foot care outcomes. It may be used by clinical teams with a view to improve outcomes for patients with diabetes.

Anaesthesia during Carotid Endarterectomy and Urinary Neopterin

Recent systematic reviews of randomized controlled trials show that the rate of postoperative complications after carotid endarterectomy (CEA) was not significantly different between operations performed under general anesthesia (GA) or local anesthesia (LA). However, these studies were not large enough to draw meaningful conclusions about any difference in mortality. This study therefore aimed to compare a surrogate endpoint of postoperative mortality between GA and LA by using urinary neopterin. 68 consecutive patients admitted electively for CEA were studied. Urinary neopterin levels were assayed preoperatively, immediately postoperatively (PO), 4, 6, 12, and 24 hrs PO. This study compared the level of urinary neopterin between GA and LA. Of the 68 CEAs, 48 operations were performed under GA. Urinary neopterin concentration in LA group increased PO and reached a peak at 6 hrs PO. At this point, the urinary neopterin levels in the GA group (85.3 μmol/mol creatinine) were significantly lower than those under the LA group (123.4 μmol/mol creatinine) (P=0.02). We found that the level of urinary neopterin level after operation in LA was significantly higher than those under GA. More studies are needed.

History of foot ulcers increases mortality among patients with diabetes in Northern Thailand

AIMS

Studies within the Caucasian population with diabetes showed an increased mortality in patients with diabetic foot ulcers. However, there were no such studies based on Asian populations. We therefore designed our study on the association of foot ulcer with mortality within the Asian population.

METHODS

Ninety-seven Asian individuals with diabetes who had previously participated in the 'Multidisciplinary Diabetic Foot Protocol' between 2005 and 2007 at our centre were followed up in 2010 to ascertain their mortality rate. Cox proportional-hazard regression analyses were used to estimate hazard ratios.

RESULTS

Forty-seven patients had a history of foot ulcer (group 1), while 50 had none (group 2). The mean follow-up was 43.74 months. Twenty-one patients died during this period (21.65%). The mortality rates in group 1 and group 2 were 15 (31.92%) and six (12.00%), respectively. Patients with a history of foot ulcer had higher mortality rates than those without (hazard ratio 3.51, 95% CI 1.03-11.96, P = 0.04).

CONCLUSIONS

Our study showed that history of foot ulcer increased mortality. This association appeared to be stronger in younger Asian patients than those in the Caucasian populations.

Meta-analysis of small randomized controlled trials in surgery may be unreliable

Background

Meta-analysis of randomized controlled trials (RCTs) should provide reliable evidence about the effects of interventions. This may be less reliable when only small trials are available.

Methods

The sample size was determined for all surgical RCTs included in Cochrane Collaboration systematic reviews. The difficulty in interpreting meta-analysis of small trials is illustrated using two specific reviews.

Results

The typical sample size for surgical RCTs was small with a median of only 87 participants. Only 39·8 per cent had adequate prerandomization treatment allocation concealment. In both systematic reviews that were assessed in detail, statistically significant early results from meta-analysis of several small RCTs did not reliably predict the results of subsequent RCTs.

Conclusion

Surgical RCTs tend to be small and underpowered. Meta-analysis of such trials does not necessarily produce reliable results.

A Multidisciplinary Diabetic Foot Protocol at Chiang Mai University Hospital: Cost and Quality of Life

The consensus is that a multidisciplinary approach for patients with diabetic foot ulcer is effective in reducing the number of leg amputations. Concern remains, however, about cost and health-related quality of life issues. From August 2005 to March 2007, a multidisciplinary diabetic foot protocol (DFP) was used at the authors’ teaching hospital.There were devices to reduce pressure on the foot.After healing, there were custom-fabricated orthoses and footwear, and monitoring of progress in ambulation. All subjects were educated about diabetic foot disease and its complications and prevention.They were also instructed to call and visit the hospital if there were any signs of new lesions.This study compared responses to the short form 36 questionnaires (SF-36) about health-related quality of life and the cost of medical care for patients receiving DFP care from August 2005 to March 2007 and those who had standard care from August 2003 to July 2005.There were 56 and 40 diabetic foot ulcer patients on DFP and standard care packages, respectively. Their gender distribution and mean age were similar. The average total cost of DFP patients was significantly lower than that for standard care patients ($1127.02 and $1824.58, respectively, P = .02). DFP patients had significantly higher scores on the SF-36 for both the physical and mental health dimensions than standard care patients. It was concluded that DFP was less expensive and gave patients a better quality of life, compared to standard care. On the basis of this finding, DFP should be used by every hospital to improve outcomes for patients with diabetic foot ulcer.

Venous insufficiency due to chronic traumatic arteriovenous fistula: two case reports

Chronic traumatic arteriovenous fistula (AVF) is a rare complication of vascular injury, and few papers have reported on its consequences to the venous system, that is, venous insufficiency. The author has highlighted this problem with 2 case reports in this case presentation. One patient had recurrent chronic ulcer of the left foot. The other patient developed deep vein thrombosis following repair to the large AVF of the right thigh.

Mini-laparotomy for repair of infrarenal abdominal aortic aneurysm

AIM

In this study, we evaluated the surgical results of minimal incision aortic surgery (MIAS) compared with the transabdominal approach (TPA) and the retroperitoneal approach (RPA) to repair non-ruptured infrarenal abdominal aortic aneurysm (AAA).

METHODS

Three different surgical techniques were studied prospectively in 72 consecutive patients with non-ruptured infrarenal AAA. These patients were randomized into 3 groups of 24 patients each. Group I comprised of patients who underwent MIAS repair. They were compared with group II patients, who underwent the traditionally long midline TPA, and group III patients, who underwent the left RPA to repair non-ruptured infrarenal AAA. All surgery was performed between January 2000 and December 2004. Demographic characteristics, including age, sex, body weight, aneurysm size, previous abdominal operations and comorbid factors of the three groups studied, were compared using the Fischer's exact test. Parameters including operative time, intraoperative fluid administration, and transfusion requirements were compared using the 2-tailed Student t test. Length of stay in the Intensive Care Unit (ICU), time to resumption of regular dietary feeding, and hospital length of stay were recorded and compared using the Wilcox rank sum test. The incidence of 30 day postoperative complications and mortality were compared between the three groups. All 72 patients who entered this study had informed consent.

RESULTS

There was no significant difference between group I (MIAS), group II (TPA), and group III (RPA) with regard to age, sex distribution, aneurysm size, or body weight. There was male sex prevalence in all three groups. Surgical exposure of the common femoral arteries was more commonly required in group III (RPA) than in the other groups. Although the length of incision tended to be longer in group III (RPA) than in group II (TPA) and I (MIAS), there was no significant difference in intraoperative time, or aortic cross-clamped time among the three groups. There was a significant difference in the need for intraoperative fluid, the most being in group II (TPA) and the least in group I (MIAS). There was significantly less blood loss in group I (MIAS), as compared with the other 2 groups, but intraoperative blood transfusion for all groups was not significantly different. ICU stay, return to general dietary feeding, and hospital length of stay for group I (MIAS) and III (RPA) were significantly lower than in group II (TPA), which had a higher incidence of postoperative ileus.

CONCLUSIONS

MIAS is as safe as retroperitoneal repair and standard transabdominal repair in the treatment of non-ruptured infrarenal AAA, and also more costefficient than retroperitoneal and standard transabdominal repair.

A Systematic Review of the Associations between Age and Sex and the Operative Risks of Carotid Endarterectomy

BACKGROUND

Randomized trials of carotid endarterectomy (CEA) for both symptomatic and asymptomatic carotid stenosis have demonstrated that benefit is decreased in women, due partly to a high operative risk, which is independent of age. However, it is uncertain whether these trial-based observations are generalisable to routine clinical practice.

METHODS

We performed a systematic review of all publications reporting data on the association between age and/or sex and procedural risk of stroke and/or death following CEA from 1980 to 2004.

RESULTS

62 eligible papers reported relevant data. Females had a higher rate of operative stroke and death (25 studies, OR = 1.31, 95% CI = 1.17-1.47, p < 0.001) than males, but no increase in operative mortality (15 studies, OR = 1.05, 95% CI = 0.81-0.86, p = 0.78). Compared with younger patients, operative mortality was increased at > or =75 years (20 studies, OR = 1.36, 95% CI = 1.07-1.68, p = 0.02), at age > or =80 years (15 studies, OR = 1.80, 95% CI = 1.26-2.45, p < 0.001) and in older patients overall (35 studies, OR = 1.50, 95% CI = 1.26-1.78, p < 0.001). In contrast, risk of non-fatal stroke did not increase with age and so the combined perioperative risk was only slightly increased at age > or =75 years (21 studies, OR = 1.18, 95% CI = 0.94-1.44, p = 0.06), at age > or =80 years (10 studies, OR = 1.14, 95% CI = 0.92-1.36, p = 0.34) and in older patients overall (36 studies, OR = 1.17, 95% CI = 1.04-1.31, p = 0.01).

CONCLUSIONS

The effects of age and sex on the operative risk of CEA in published case series are consistent with those observed in the trials. Operative risk of stroke is increased in women and operative mortality is increased in patients aged > or =75 years.

Systematic review of randomized controlled trials of patch angioplasty versus primary closure and different types of patch materials during carotid endarterectomy

BACKGROUND

Patch angioplasty during carotid endarterectomy (CEA) may reduce the risk for perioperative or late carotid artery recurrent stenosis and subsequent ischemic stroke. We performed a systematic review of randomized controlled trials to assess the effect of routine or selective carotid patch angioplasty compared with CEA with primary closure, and the effect of different materials used for carotid patch angioplasty.

METHODS

Randomized trials were included if they compared carotid patch angioplasty with primary closure in any patients undergoing CEA or use of one type of carotid patch with another.

RESULTS

Thirteen eligible randomized trials were identified. Seven trials involving 1281 operations compared primary closure with routine patch closure, and 8 trials with 1480 operations compared different patch materials (2 studies compared both). Patch angioplasty was associated with a reduction in risk for stroke of any type (P = .004), ipsilateral stroke (P = .001), and stroke or death during both the perioperative period (P = .007) and long-term follow-up (P = .004). Patching was also associated with reduced risk for perioperative arterial occlusion (P = .0001) and decreased recurrent stenosis during long-term follow-up (P < .0001). Seven trials that compared different patch types showed no difference in the risk for stroke, death, or arterial recurrent stenosis either perioperatively or at 1-year follow-up. One study of 180 patients (200 arteries) compared collagen-impregnated Dacron (Hemashield) patches with polytetrafluoroethylene patches. There was a significant increase in risk for stroke (P = .02), combined stroke and transient ischemic attack (P = .03), and recurrent stenosis (P = .01) at 30 days, and an increased risk for late recurrent stenosis greater than 50% (P < .001) associated with Dacron compared with polytetrafluoroethylene.

CONCLUSIONS

Carotid patch angioplasty decreases the risk for perioperative death or stroke, and long-term risk for ipsilateral ischemic stroke. More data are required to establish differences between various patch materials.

Seasonal variation of Buerger's disease in Northern part of Thailand

OBJECTIVES

Buerger's disease is a common peripheral arterial occlusive disease in Asia, Middle East, and eastern European countries. This study was undertaken to investigate the seasonal variation in admission pattern of with patients Buerger's disease at our institution which is a referral hospital in the Northern Thailand.

MATERIAL AND METHODS

Patients with Buerger's disease admitted to Chiang Mai University Hospital between January 1987 and December 2002 were studied retrospectively. Data are reported as mean+/-SD. Statistical significance was analyzed by Chi-square test.

RESULTS

Eighty-four patients (82 men and two women) with Buerger's disease were evaluated on 121 admissions. Forty-five were newly diagnosed cases, who were admitted for initial treatment, and 39 were known cases who experienced worsening of the disease. Sixty-three admissions (52%) took place during winter (November to February), 44 admissions (34.6%) during the rainy season (June-October) and only 14 admissions (11.6%) occurred during the summer (March-May). There was a significant difference in the monthly admission rates during the three seasons (p<0.05).

CONCLUSION

Admission for Buerger's disease showed a significant seasonal variation, with a peak in the winter followed by the rainy and summer season, respectively. Further research is needed to confirm our findings and evaluate the underlying mechanisms.

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 safety and efficacy of routine or selective carotid patch angioplasty compared to carotid endarterectomy with primary closure.

SEARCH STRATEGY

We searched the Cochrane Stroke Group Trials Register (last searched November 2002). In addition, we searched the Cochrane Controlled Trials Register (The Cochrane Library, Issue 4, 2001), MEDLINE (1966 to December 2001), EMBASE (1980 to December 2001) and Index to Scientific and Technical Proceedings (1980 to 2001). We also handsearched eight journals and five conference proceedings. Reference lists were checked and we contacted experts in the field to identify further published and unpublished studies.

SELECTION CRITERIA

Randomised and quasi-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

The previous review included six trials involving 794 patients undergoing 882 operations. Since the last review only one study of adequate quality to be included has been reported. This added 399 operations randomised to either primary closure, vein patch or synthetic patch groups resulting in 1127 patients undergoing 1307 operations being available for analysis. The quality of trials was generally poor. Follow-up varied from hospital discharge to five years. Carotid patch angioplasty was associated with a reduction in the risk of stroke of any type (OR = 0.33, p = 0.004), ipsilateral stroke (OR = 0.31, p = 0.0008), and stroke or death, during the perioperative period (OR = 0.39, p = 0.007) and long term follow-up (OR = 0.59, p = 0.004). It was also associated with a reduced risk of perioperative arterial occlusion (odds ratio 0.15, 95% confidence interval 0.06 to 0.37 p = 0.00004), and decreased restenosis during long-term follow-up in five trials, (odds ratio 0.20, 95% confidence interval 0.13 to 0.29 p < 0.00001). These results are more certain than those of the previous review since the number of operations and events have increased. However, the sample sizes are still relatively small, data were not available from all trials, and there was significant loss to follow-up. Very few arterial complications, including haemorrhage, infection, cranial nerve palsies and pseudo-aneurysm formation were recorded with either patch or primary closure. No significant correlation was found between use of patch angioplasty and the risk of either perioperative or long-term all-cause death rates

REVIEWERS' CONCLUSIONS

Limited evidence suggests that carotid patch angioplasty may reduce the risk of perioperative arterial occlusion and restenosis. It would appear to reduce the risk of combined death or stroke and there is a non significant trend towards a reduction in all-cause mortality.

Patches of different types for carotid patch angioplasty

BACKGROUND

Some surgeons who use carotid patching favour using a patch made from an autologous vein, whilst others prefer to use synthetic materials.

OBJECTIVES

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

SEARCH STRATEGY

We searched the Cochrane Stroke Group trials register (last searched November 2002). In addition, we searched the Cochrane Controlled Trials Register (The Cochrane Library, Issue 4, 2001), MEDLINE (1966 to December 2001), EMBASE (1980 to December 2001) and Index to Scientific and Technical Proceedings (1980 to 2001). We also handsearched eight journals and five conference proceedings. Reference lists were checked and we contacted experts in the field to identify further published and unpublished studies.

SELECTION CRITERIA

Randomised and quasi-randomised trials comparing one type of carotid patch with another for carotid endarterectomy.

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

The previous version of this review included three trials involving 326 operations. Since then a further five trials have been reported, increasing the number of operations to 1480. Prior to 1995, all studies had compared vein closure with PTFE closure, but three of the later studies compared vein to Dacron grafts instead and one compared Dacron with PTFE. Allocation was not adequately concealed in two trials, and one only followed up patients to the time of hospital discharge. Intention to treat analysis was possible for six trials. In all but two trials a patient could be randomised twice and have each carotid artery randomised to different treatment groups. There were too few operative events to determine whether there was any difference between the vein and Dacron patches for perioperative stroke, death and arterial complications. The one study that compared Dacron and PTFE patches found a significant risk of combined stroke and transient ischaemic attack (p = 0.03) and restenosis at 30 days (p = 0.01), a borderline significant risk of perioperative stroke (p = 0.06), and a non significant increased risk of perioperative carotid thrombosis (p = 0.1) with dacron compared with PTFE. Five trials followed up patients for longer than 30 days. During 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 15 events in 776 patients in four trials, there were significantly fewer pseudoaneurysms associated with synthetic patches than vein (odds ratio [OR] 0.09, 95% confidence interval [CI] 0.02 to 0.49) but the numbers involved were small and the clinical significance of this finding is uncertain.

REVIEWERS' CONCLUSIONS

It is likely that the differences between different types of patch material are very small. Consequently, many more data than are currently available will be required to establish whether any differences do exist. Some evidence exists that PTFE patches may be superior to Colagen impregnated Dacron grafts in terms of perioperative stroke rates and restenosis. However the evidence is based upon data from a single, small trial and more studies that compare different types of synthetic graft are required to make firm conclusions. Psuedo aneurysm formation may be more common after use of a vein patch compared with a synthetic patch.

Local versus general anaesthesia for carotid endarterectomy

BACKGROUND

Carotid endarterectomy reduces the risk of stroke in people with recently symptomatic, severe carotid artery stenosis. However, there are significant perioperative risks which may be lessened by performing the operation under local rather than general anaesthetic.

OBJECTIVES

The aim of this review was to assess the risks of endarterectomy under local compared with general anaesthetic.

SEARCH STRATEGY

We searched the Stroke Group trials register (April 2003), MEDLINE (1966 to April 2003), EMBASE (1980 to 2002), and Index to Scientific and Technical Proceedings (1980 to 1994). We handsearched 13 relevant journals up to 2002, and searched the reference lists of articles identified. We also advertised the review in Vascular News (a newspaper for European vascular specialists) in August 2001.

SELECTION CRITERIA

Randomised trials and non-randomised studies comparing carotid endarterectomy under local versus general anaesthetic.

DATA COLLECTION AND ANALYSIS

One reviewer selected studies for inclusion and another independently checked the decisions. Two reviewers assessed trial quality and independently extracted the data.

MAIN RESULTS

Seven randomised trials involving 554 operations, and 41 non-randomised studies involving 25622 operations were included. The methodological quality of the non-randomised trials was questionable. Eleven of the non-randomised studies were prospective and 29 reported on a consecutive series of patients. In nine non-randomised studies the number of arteries, as opposed to the number of patients, was unclear. Meta-analysis of the non-randomised studies showed that the use of local anaesthetic was associated with significant reductions in the odds of death (35 studies), stroke (31 studies), stroke or death (26 studies), myocardial infarction (22 studies), and pulmonary complications (7 studies), within 30 days of the operation. Meta-analysis of the randomised studies showed that the use of local anaesthetic was associated with a significant reduction in local haemorrhage (OR = 0.31, 95% CI = 0.12 to 0.79) within 30 days of the operation, but there was no evidence of a reduction in the odds of operative stroke. However, the trials were too small to allow reliable conclusions to be drawn, and in some studies intention-to-treat analyses were not possible because of exclusions.

REVIEWERS' CONCLUSIONS

There is insufficient evidence from randomised trials comparing carotid endarterectomy performed under local and general anaesthetic. Non-randomised studies suggest potential benefits with the use of local anaesthetic, but these studies may be biased. More randomised studies are needed.

Time Trends in the Published Risks of Stroke and Death due to Endarterectomy for Symptomatic Carotid Stenosis

BACKGROUND

Large randomised trials performed in the 1980s and early 1990s showed that carotid endarterectomy (CEA) is beneficial for patients with recently symptomatic severe stenosis. Some surgeons have argued that the operative risk of stroke and death has fallen over the last decade due to refinements in operative technique, and that the indications for surgery should therefore now be broadened. Yet, studies of routinely collected data report higher operative mortality than in the trials, and surgical case series without independent post-operative assessment by a neurologist may not provide reliable data on stroke risk.

METHODS

We performed a systematic review of all studies published between 1994 and 2001 inclusive that which reported the risks of stroke and death for symptomatic carotid stenosis, and compared the reported risks and patient characteristics with those in the ECST and NASCET and with our previous review of studies published prior to 1995. Pooled estimates of the operative risk of stroke and death were obtained by Mantel-Haenszel meta-analysis.

RESULTS

Of 383 studies published between 1994 and 2001, only 45 reported operative risks for patients with symptomatic stenosis separately. The pooled operative risk of stroke and death reported in studies published by surgeons only (4.2%, 95% CI = 2.9-5.5, 34 studies) was significantly lower (p < 0.0001) than that in the ECST and NASCET combined (7.0%, 95% CI = 6.2-8.0), whereas the pooled risk reported in studies that involved neurologists was similar (6.5%, 95% CI = 4.3-8.7, 11 studies, p = 0.6). In contrast, operative mortality in ECST and NASCET was significantly lower than in other studies published between 1994 and 2001. By comparison with our previous review, when stratified according to involvement of neurologists, we found no evidence of a reduction in published risks of death or stroke and death due to CEA between 1985 and 2001.

CONCLUSIONS

There is no evidence of a systematic reduction over the last decade in the published risks of stroke and death due to CEA for symptomatic stenosis. Operative risks in studies with comparable outcome assessment are similar to ECST and NASCET. The surgical data from the large trials are still likely therefore to be applicable to routine clinical practice.

Systematic review of the risks of carotid endarterectomy in relation to the clinical indication for and timing of surgery

BACKGROUND AND PURPOSE

Reliable data on the risk of carotid endarterectomy (CEA) in relation to clinical indication and timing of surgery are necessary to target CEA more effectively, to inform patients, to adjust risks for case mix, and to understand the mechanisms of operative stroke.

METHODS

We performed a systematic review of all studies published from 1980 to 2000 inclusive that reported the risk of stroke and death resulting from CEA. Pooled estimates of risk by type of presenting ischemic event and time since the last event were obtained by Mantel-Haenszel meta-analysis.

RESULTS

Of 383 published studies, only 103 stratified risk by indication. Although the operative risk for symptomatic stenosis overall was higher than for asymptomatic stenosis (odds ratio [OR], 1.62; 95% confidence interval [CI], 1.45 to 1.81; P<0.00001; 59 studies), risk in patients with ocular events only tended to be lower than for asymptomatic stenosis (OR, 0.75, 95% CI, 0.50 to 1.14; 15 studies). Operative risk was the same for stroke and cerebral transient ischemic attack (OR, 1.16; 95% CI, 0.99 to 1.35; P=0.08; 23 studies) but higher for cerebral transient ischemic attack than for ocular events only (OR, 2.31; 95% CI, 1.72 to 3.12; P<0.00001; 19 studies) and for CEA for restenosis than primary surgery (OR, 1.95; 95% CI, 1.21 to 3.16; P=0.018; 6 studies). Urgent CEA for evolving symptoms had a much higher risk (19.2%, 95% CI, 10.7 to 27.8) than CEA for stable symptoms (OR, 3.9; 95% CI, 2.7 to 5.7; P<0.001; 13 studies), but there was no difference between early (<3 to 6 weeks) and late (>3 to 6 weeks) CEA for stroke in stable patients (OR, 1.13; 95% CI, 0.79 to 1.62; P=0.62; 11 studies). All observations were highly consistent across studies.

CONCLUSIONS

Risk of stroke and death resulting from CEA is highly dependent on the clinical indication. Audits of risk should be stratified accordingly, and patients should be informed of the risk that relates to their presenting event.

C-reactive protein is elevated in symptomatic compared with asymptomatic patients with carotid artery disease

OBJECTIVES

to investigate the level of inflammatory markers between symptomatic and asymptomatic carotid stenosis patients.

DESIGN

cross-sectional study.

MATERIALS AND METHODS

a prospective study of 137 consecutive patients, admitted electively for carotid endarterectomy during 1997-2000, was conducted. 125 patients had cerebrovascular symptoms: either stroke (neurological deficit >24 h), Transient ischaemic attack (neurological deficit<24 h) or amaurosis fugax. Twelve patients were asymptomatic. A medical history and a fasting venous blood sample were taken from each patient around 6 weeks before surgery. The plasma concentrations of cholesterol and of inflammatory markers; (high sensitivity C-reactive protein (hs-CRP), sICAM-1, sVCAM-1, sE-selectin) were determined.

RESULTS

the concentration of hs-CRP in the symptomatic group (3.9 mg/L) was significantly higher than in the asymptomatic group (2.1 mg/L; p = 0.04). These concentrations were within normal range (<10 mg/L). sICAM-1, sVCAM-1, sE-selectin and total cholesterol concentrations were not different between the two groups.

CONCLUSION

plasma hs-CRP was elevated in symptomatic compared to asymptomatic patients with carotid artery disease. High sensitivity C-reactive protein has been shown to be of prognostic value in a number of cardiovascular conditions and this study suggests it may be of value to identify patient at high risk of developing neurological deficits.

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.

The retroperitoneal approach for abdominal aortic aneurysms

Graft replacement has become the reliable and effective form of treatment for abdominal aortic aneurysms (AAA). Operative therapy remains the major undertaking with significant rates of postoperative morbidity and mortality. The use of retroperitoneal approach has been proposed as an alternative to standard midline transabdominal approach. Over a 5 year period, 43 consecutive nonrandomized infrarenal AAA patients underwent elective surgical correction by the authors. 32 patients with the mean age of 75 underwent transabdominal reconstructive procedures for AAA. The average size of AAA was 5.9 cm and operative time was 3 hours and 25 minutes. The mortality rate was 6.25 per cent (2 of 32). The cause of death was myocardial infarction 1, and acute renal failure 1. There are many complications in the transabdominal group. 11 had prolonged ileus, 2 MI, 2 wound dehiscence, 2 atelectasis, 1 acute renal failure and 1 chylous ascites. In 11 patients with retroperitoneal approach, the average size of AAA was 5.6 cm and operative time was 3 hours and 29 minutes. No operative mortality, the only 1 complication was retroperitoneal hematoma. The most notable difference between the retroperitoneal group and transabdominal group was the speed and ease of postoperative recovery. The patients in the retroperitoneal group needed a shorter period of intubation, nasogastric drainage, stay in the intensive care unit and hospital. Patients in the retroperitoneal group also resumed oral alimentation sooner, shorter and smoother postoperative course. The patients in the retroperitoneal group had less blood loss and fewer transfusions than in the transabdominal group. Findings from our experience using the left retroperitoneal approach for a reconstructive procedure of AAA indicate that it results in fewer overall physiologic disturbances of the patients. We believe that the left retroperitoneal approach is a useful surgical access of choice for the elective repair of AAA.

Associated growth of wheat and annual ryegrass. III. Effects of early competition on wheat

The effects of four factors applied in factorial combination, viz. nitrogen application, time of ryegrass germination relative to wheat, roots together or separate and species proportion, were studied during the first few weeks of the associated growth of wheat and annual ryegrass. The experiment was conducted in boxes in a glasshouse at a total density of 355 plants m-2. Many plant variates were measured at 7, 28 and 49 days from sowing. Nitrogen content was determined at 28 and 49 days. Even at 7 days, measurable treatment effects on root and shoot weights of wheat could be detected. The effects could be discerned subsequently in terms of root length, tillering patterns, shoot weight, and ear development. Effects on ear development were observed in the last tiller and on the most recently developed florets. Some of these responses involved interactions of two or more of the factors studied. Treatments modified the relationship between competitive ability and yield in pure culture, more in ryegrass than in wheat. Although nitrogen effects appeared to have a strong influence on the competitive relations between the species, it is suggested that competition for soil factors other than nitrogen may also have been involved.