Infrapopliteal composite bypass with autologous vein and second generation glutaraldehyde stabilized human umbilical vein (HUV) for critical lower limb ischaemia.

OBJECTIVE: To audit a single center consecutive series of infrapopliteal composite bypasses with second generation glutaraldehyde stabilized human umbilical vein. DESIGN: Retrospective study. PATIENTS: From January 1996 to July 2006 89 femoro-distal bypasses were constructed in 85 patients with HUV and residual vein segments as composite grafts in the absence of sufficient length of autologous vein. METHODS: All patients with infrainguinal bypass operations were registered prospectively. Bypasses to infrapopliteal arteries performed with HUV-composite grafts were reviewed for graft patency, limb salvage, patient survival and possible biodegeneration of the HUV. RESULTS: Early graft thrombosis was noted in 21.3%, necessitating revision surgery. Primary, primary assisted and secondary patency rates were 35%, 40% and 42% respectively, with a limb salvage rate of 87% after 5 years. Graft infection occurred in 7 limbs. Aneurysmal HUV graft degeneration was not detected by duplex scanning. CONCLUSION: HUV-composite bypasses provide acceptable patency and favorable limb salvage rates. Patency was similar to previous series using PTFE-composite bypasses but was significantly inferior to vein bypass. Possible biodegradation of the HUV grafts seems to be of minor clinical relevance.     

Lipoprotein (a) level and mortality in patients with critical lower limb ischaemia.

OBJECTIVE: to investigate if serum lipoprotein (a) level is a predictor of survival in patients with lower limb atherosclerotic occlusive disease. DESIGN: prospective follow up study. METHODS: demographic, biochemical and disease variables were collected prospectively in 441 patients with lower limb arterial occlusive disease. Survival data were obtained at a mean follow up of 44 months, and significant risk factors identified by the life table method and multivariate Cox regression analysis. RESULTS: the cumulative survival for all patients at three and five years was 79% and 63%. Lipoprotein (a) level was the only significant independent biochemical predictor for all deaths and cardiorespiratory deaths on multivariate analysis, along with age, diabetes mellitus, renal impairment, cardiac diseases and major amputation. An elevated Lipoprotein(a) level of >24 mg/dl incurred a 107% and 45% increase in mortality at three and five years respectively. The higher mortality associated with elevated Lipoprotein (a) was particularly evident in patients with critical ischemia, in whom three and five year survival was reduced from 85% to 63% and 67% to 53% (p=0.0064). In claudicants a survival discrepancy was manifested only after five years (73% vs 62%), and the overall association did not reach statistic significance (p=0.52). CONCLUSIONS: lipoprotein (a) level is a reliable biochemical marker for survival in patients with critical ischemia where traditional atherosclerosis risk factors were prevalent.     

Oedema in the lower limb of patients with chronic critical limb ischaemia (CLI).

OBJECTIVE: approximately 70% of patients with chronic critical limb ischaemia (CLI) show clinical signs of oedema in the distal leg and foot. The primary aim of the present investigation was to quantify this oedema. In addition we investigated whether oedema formation could be due to deep venous thrombosis (DVT). METHODS: fifteen patients with unilateral CLI and oedema were studied, four males and 11 females, with a mean age of 77+/-10.3 years. Water displacement volumetry (WDV) was used to measure limb volume. Colour duplex ultrasound (CDU) and venous occlusion plethysmography (VOP) were applied to exclude functionally significant DVT. Blood chemistry was analysed to screen for some causative factors of generalised oedema formation. RESULTS: the mean volume of the limbs with CLI was 9% greater than the contralateral limbs (1279+/-325 ml vs. 1179+/-298 ml). None of the patients had functionally significant DVT. The mean plasma albumin concentration was reduced at 28.5+/-6.6 g/l. CONCLUSION: a significantly reduced plasma albumin concentration cannot be regarded as a causative factor, since the oedema is unilateral. The aetiology of oedema formation is probably multifactorial, and further investigations are under progress to elucidate relevant pathogenetic factors.     

Vascular and stromal features in the skin of the lower limb in patients with chronic critical limb ischaemia (CLI) and oedema.

OBJECTIVE: peripheral oedema is often observed in limbs affected by chronic critical limb ischaemia (CLI) and is mainly subcutaneous in distribution. Previous work has shown that capillary filtration coefficient (CFC) in limbs with CLI and oedema was twice as great as that in the contralateral limb. These changes might be due to morphological changes. Transmission electron microscopy (TEM) was used to examine the morphological features of the capillary walls and surrounding stromal tissues in the skin of these limbs. MATERIAL AND METHODS: eight patients with unilateral CLI and peripheral pitting oedema (four men, four women, a mean age of 81+/-6.9 years) was studied. Skin biopsies were taken from the pulp of the first toe, interdigital space between the first and second digits and dorsal part of forefoot just prior to amputation. RESULTS: stromal oedema and dilated capillaries were most prominent in the distal part of the foot. Some of the capillaries were filled with blood cells and some were empty. The endothelium of the dilated vessels was elongated and distended. In some patients a number of capillaries were collapsed with degenerate endothelial cells. , i.e. large openings, were found between the elongated oedematous endothelial cells. The basal lamina was thickened in all patients. Stromal haemorrhage and degeneration were seen in approximately 50% of patients. CONCLUSION: CLI causes ultrastructural changes in the capillary endothelium and surrounding stroma. The presence of large gaps between endothelial cells as well as an increased capillary pressure may enhance transcapillary transudation, and are most likely the causative factors in the formation of the ischaemic oedema. The stromal haemorrhage as well as degeneration probably signifies a terminal stage of CLI.     

Aggressive arterial reconstruction for critical lower limb ischaemia.

A consecutive series of 315 patients underwent arterial reconstruction for 329 critically ischaemic lower limbs over a 5-year period. Patients were not excluded from limb salvage surgery on the basis of poor run-off on preoperative angiography. Femorocrural bypass to a single calf vessel was required in 239 limbs (73 per cent); the 30-day cumulative mortality rate was 7 per cent, rising to 41 per cent at 5 years. Cumulative graft patency at 30 days, 1 year, 2 years and 5 years was 96, 85, 84 and 82 per cent respectively and was independent of the level of reconstruction. In situ long saphenous vein was the conduit of choice for distal bypass but, when this was absent, satisfactory results were obtained with arm vein or composite vein grafts. Acceptable results can be obtained for reconstructive surgery without preoperative angiographic selection of patients. An aggressive approach to limb salvage is therefore justified.     

Managing risk factors for atherosclerosis in critical limb ischaemia.

OBJECTIVE: To review the best medical management of critical limb ischaemia (CLI). METHODS: Published studies dealing with CLI and risk factors were searched for via PUBMED. FINDINGS AND CONCLUSIONS: Patients with critical limb ischaemia (CLI) have a one and ten year mortality of approximately 20% and 75% respectively. Risk factors for the development of peripheral atherosclerosis are the same as for coronary and cerebrovascular atherosclerosis namely diabetes mellitus, hyperlipidaemia, arterial hypertension, and smoking. As there are few studies of risk factor for peripheral arterial occlusive disease (PAOD), treatment recommendations are often based on studies in patients with coronary or cerebrovascular atherosclerosis. While waiting for specific studies, CLI patients should be treated according to current guidelines for other atherosclerotic patients.     

Recognising anaemia and malnutrition in vascular patients with critical limb ischaemia

INTRODUCTION

Anaemia is a common problem in surgical patients. Patients with critical limb ischaemia (CLI) suffer chronic inflammation, repeated infection, require intervention, and can have a protracted hospital stay. The aims of this study were to assess anaemia and nutritional status in patients presenting with CLI.

PATIENTS AND METHODS

Two observational studies were undertaken, initially a retrospective series of 27 patients with CLI. Patient demographics, clinical details, transfusion status and in-patient laboratory haemoglobin values (Hb) were recorded. In a prospective series of 32 patients, laboratory markers to identify the cause for anaemia were assessed. Further nutritional status was assessed by records of height, weight, body mass index and a validated scoring system.

RESULTS

In the retrospective series, 15 patients (56%) were anaemic. Ten (37%) were transfused a median of 2 units (range, 2–13), a total of 35 units. Patients who were transfused had lower Hb on admission (P = 0.0019), most were anaemic on admission (90%). At discharge, most patients were anaemic (n = 23; 83%). In the prospective series of 32 patients, 20 (63%) were anaemic. Nutritional assessment was performed on 18, only seven patients were scored undernourished. This was increased to 23 by an independent assessor. Anaemia was associated with malnutrition (n = 17; P = 0.049) and an increased hospital stay (mean 25 days [SD 16] vs mean 12 days [SD 8], P = 0.0125; total 513 vs 144 bed days).

CONCLUSIONS

Anaemia and poor nutrition are common and not recognised in vascular patients presenting with critical limb ischaemia. Anaemia is associated with and increased length of hospital stay.     

Percutaneous transluminal angioplasty for critical limb ischaemia in octogenarians and nonagenarians.

OBJECTIVE: To determine the early and late outcome of percutaneous transluminal angioplasty (PTA) for critical limb ischaemia (CLI) in patients aged 80 years and over. METHODS: Retrospective case note review of all patients aged 80 years and over who underwent attempted PTA for CLI between 1st January 1999 and 31st December 2000. Minimum follow-up was 12 months with a maximum of 42 months. RESULTS: One hundred and twenty-eight PTAs were attempted in 113 severely ischaemic limbs of 98 patients (36 men and 62 women of median age 84, range 80-97, years). Seventy patients had significant co-morbidity. The indication for revascularisation was rest pain in 47 procedures, ulceration in 66 and digital gangrene in 15. The anatomical segments involved were iliac (n=19), superficial femoral (n=92), popliteal (n=91) and infrapopliteal (n=72). The technical success rate was 108 of 128 (84%) procedures. Early technical complications occurred in 24 (19%) procedures: four major, 20 minor. The 30-day operative mortality rate was six of 128 (5%). The median (range) in-hospital stay was two (1-72) days. Early or delayed surgical revascularisation was required in 11 limbs and there were six major limb amputations during the study period. The 24-month patient survival rate was 59%. The 24-month primary and secondary symptomatic patency and secondary limb salvage rates were 52, 69 and 95%, respectively. DISCUSSION: PTA is safe, requires a short hospital stay, and is clinically effective in the majority of very elderly patients with CLI. Although minimally invasive, the relatively high peri-procedural mortality rate and low 24-month survival rate reflect the high co-morbidity of this group of patients.     

Cold-stored venous allografts in the treatment of critical limb ischaemia.

OBJECTIVES: To assess the outcome of cold-stored venous allografts in critically ischemic limbs in patients with no ipsilateral autogenous greater saphenous vein. DESIGN: A non-randomised, retrospective, single-center study. METHODS: From September 2000 to June 2006, 46 cold-stored venous allografts obtained during multiorgan harvest were implanted into 44 critically ischaemic limbs of 43 patients. The indication for reconstructions was rest pain (24%) or tissue lost (76%). Sixty-seven percent of procedures were performed as secondary reconstructions, and 61% of veins were anastomosed to tibial or pedal arteries. Thirty-seven percent of patients received prednisone, and 46% tacrolimus as postoperative immunosuppressive therapy. Mean patient follow-up period was 13.3 months (range 1 week to 60 months). RESULTS: The secondary patency rate for the cohort was 83+/-5.6% at 1 month, 64+/-8.2% at 6 months, 57+/-10.0% at 12 months and 46+/-10.7% at 24 months. Limb salvage rate was 96+/-3.1% at 1 month, 78+/-6.9% at 6 months, 71+/-8.1% at 12 months and 50+/-11.8% at 24 months. CONCLUSION: Cold-stored venous allografts are an alternative conduit for limb salvage procedures when ipsilateral autogenous vein is unavailable.     

The lack of cardiovascular risk factor management in patients with critical limb ischaemia.

AIM: to define the level of management of cardiovascular risk factors in patients treated for critical limb ischaemia in a vascular surgical setting. MATERIALS AND METHODS: retrospective review of all (n =147) patients operated on for critical lower extremity ischaemia in 1998. We included pre- and postoperative cardiac events. RESULTS: only eight (5%) (95% CI; 2-9) were on lipid lowering treatment and 58 (39%) (95% CI; 31-47) using acetylsalicylic acid. CONCLUSIONS: only a minority of patients operated on for CLI were receiving adequate cardiovascular risk factor modification.     

Peri-operative myocardial injury in patients undergoing surgery for critical limb ischaemia.

INTRODUCTION: Although up to a half of patients undergoing abdominal aortic aneurysm (AAA) repair suffer myocardial injury, as indicated by a rise in cardiac troponin I (cTnI), this is infrequently accompanied by a rise in creatine kinase (CK)-MB fraction or electrocardiogram (ECG) changes. This study compares for the first time peri-operative cTnI, CK-MB and ECG changes in patients undergoing surgery for critical lower limb ischaemia (CLI). METHODS: Twenty-nine patients (20 men, median age 75 [range, 57-95] years) were studied prospectively. cTnI, CK/CK-MB ratio and ECG were performed pre-operatively and on post-operative days 1, 2 and 3. RESULTS: Eleven (38%) patients had an elevated cTnI >0.5 ng/ml. Five (17%) patients had an elevated CK-MB fraction >4% and all of these patients had an elevated cTnI. Eleven (38%) patients had ischaemic changes on ECG including seven of 11 (64%) patients with elevated cTnI and all five patients with elevated CK-MB fraction. There was no relationship between pre-operative cardiac status, antiplatelet use or type of anaesthesia and post-operative cTnI rise. Patients with a cTnI rise were younger (p=0.01), and were more likely to have presented with gangrene (p=0.04) and have a longer operation time (p=0.01) than patients who did not demonstrate a cTnI rise. Four patients developed clinically apparent cardiac complications: cardio-pulmonary arrest (n=1), cardiogenic shock (n=1), acute CCF (n=1) and rapid atrial fibrillation (n=1). Survival at 6 months was 26 of 29 (90%) patients. CONCLUSION: These data demonstrate that over a third of patients operated for CLI sustain peri-operative myocardial injury, many of which are not clinically apparent. Pre-operative medical optimisation may improve prognosis in this group of patients.     

Role of infrainguinal angioplasty in the treatment of critical limb ischaemia.

OBJECTIVE: To review the published papers reporting on the use of infrainguinal angioplasty in the treatment of critical limb ischaemia (CLI). METHODS: A MEDLINE (1966-2005) and Cochrane library search for articles relating to the use of infrainguinal angioplasty in the treatment of CLI. RESULTS: Recent papers reporting on the results of infrainguinal angioplasty as treatment for CLI patients show excellent limb salvage rates regardless of the patency rates. The Cochrane Database of systematic reviews has accepted two prospective randomised trials comparing bypass operations and angioplasty among CLI patients. Pooling both trials showed no overall significant difference in amputation rates between the surgery and PTA groups. A multicentre, randomised controlled trial, the BASIL (Bypass versus Angioplasty in Severe Ischaemia of the Leg) trial showed that in the medium term (after six months), the outcomes after angioplasty or surgery among CLI patients did not differ significantly with respect to amputation-free survival, all-cause mortality and quality of life. CONCLUSIONS: Infrainguinal PTA is feasible in CLI patients. Data from the BASIL trial show the similar ability of bypass surgery and balloon angioplasty in preserving both life and limb in short term. These results are, however, not applicable for the majority of CLI patients as only 15% (70/456) of the patients with severe limb ischaemia were considered candidates for the trial.     

Assessment of the microcirculation provides additional information in critical limb ischaemia.

Systolic ankle and toe pressure measurements are considered to be the best way of documenting arterial occlusive disease. In the European consensus, chronic critical limb ischaemia is defined as persistent pain with an ankle pressure lower than 50 mmHg. To investigate the possible adjunct value of microcirculatory assessment, capillary microscopy and transcutaneous oximetry were performed in 21 asymptomatic persons (F1), 89 claudicants (F2) and 54 patients with critical limb ischaemia (F3/4). Capillary morphology (diameter, density) and dynamics [red blood cell velocity (RBCV), peak RBCV and time to peak RBCV], as well as transcutaneous oximetry parameters were determined for each Fontaine group and compared with ankle and toe pressure measurements. Despite considerable overlap, ankle and toe pressures were significantly (p less than 0.001) different between F1, F2 and F3/4 patients. Capillary density (p less than 0.05), diameter (p less than 0.05), peak RBCV (p less than 0.05) and time to peak RBCV (p less than 0.01), as well as transcutaneous oximetry parameters (p less than 0.001) were significantly different between all groups and impaired with progression of ischaemia. However, a similar overlap between all groups was observed, except the supine TcpO2 parameter which separated F3/4 patients completely from the other groups. In all patients with critical limb ischaemia, dynamic parameters, such as peak RBCV (p less than 0.01) and time to peak RBCV (p less than 0.001), were significantly lower as compared to non-critically ischaemic patients, irrespective of an ankle pressure below or above a value of 50 mmHg, illustrating the additional value of microcirculatory assessment in these patients.(ABSTRACT TRUNCATED AT 250 WORDS)