Patient survival and limb prognosis after arterial embolectomy

Treatment of bypass failure in patients with chronic limb threatening ischemia – open surgery vs. percutaneous mechanical thrombectomy

Summary: Background: Lower limb bypass occlusion in patients with chronic limb threating ischemia remains a challenge. We can choose between different treatment options: open surgery, local thrombolysis, thrombectomy/atherectomy devices. In this pilot study, we compare clinical outcomes and treatment costs between open surgery (OS) and percutaneous mechanical thrombectomy (pMTH). Patients and methods: This pilot study represents a retrospective analysis of hospital data of 48 occluded bypasses admitted from 2013 to 2018. Only patients presenting with severe ischemia and recrudescence of symptoms (Rutherford 4–6) were included in the current analysis. Two cohorts of patients were analysed: patients who underwent OS and patients that underwent pMTH. Primary clinical outcomes were one-year cumulative patency and limb salvage rates. Total cost was calculated as a sum of intra- and post-operative costs. To weigh clinical benefits against the economic consequences of OS versus pMTH a cost-effectiveness framework was adopted. Results: We analysed a series of 48 occluded bypasses 17 treated with open surgery and 31 with pMTH. Procedural success was 100% in both groups. When comparing one-year death rates ( p-value = .22) and re-occlusion rates ( p-value = .43), no statistically significant differences were observed between the two cohorts. Mean patency duration in the surgery cohort was significantly shorter ( p-value < .05). Primary patency (OS 41.2% vs. pMTH 48.4%) and limb salvage rate (OS 88.2% vs. pMTH 90.3%) at one year are similar in both groups. The total cost of surgery was substantially higher (OS 10,159€ vs. pMTH 8,401€) Conclusions: This pilot study, although limited to 48 occluded bypasses, demonstrates that endovascular treatment with pMTH is less invasive, less time consuming and less expensive, and produces greater health benefits than traditional OS.

[Revascularization delay and complications in acute upper limb ischemia]

INTRODUCTION

Acute upper limb ischemia is a medical and surgical emergency. Studies that have reported revascularization results in acute upper limb ischemia are rare. For this reason, the revascularization delay has remained poorly defined. The purpose of this study was to evaluate surgery results of acute upper limb ischemia related to revascularization delay.

METHODS

We report a retrospective study of patients operated for acute upper limb ischemia between 2008 and 2016. Patients with thrombotic, traumatic or iatrogenic ischemia were excluded from this study. Patients were divided into two groups (those operated before 12hours and those operated after 12hours). A statistical analysis was performed to compare surgery results between the two groups in terms of limb salvage rate and neurological sequelae rate.

RESULTS

Our population consisted of 138 patients. The average age was 69 [31,92]. There were 90 women and 48 men. The mean revascularization delay was 20hours [2,240]. Seventy-six patients were operated on before 12hours and 62 patients after 12hours. At one month, the mortality was 1.4% and the morbidity was 5.7%. The overall limb salvage rate was 86.9% and the overall neurologic sequelae rate was 31.8%. Statistical analysis showed that there was no significant difference between patients operated before or after 12hours in terms of limb salvage (86.8% versus 87%, P=0.258). However, there was a statistically significant difference in terms of neurological sequelae in favor of patients operated after 12hours (15.7% versus 51.6%, P=0.012).

CONCLUSION

Revascularization of acute embolic upper limb ischemia is often associated with good results even if performed late. Beyond 12hours of ischemia, amputation rate is not significantly higher, however, the rate of neurological sequelae can be high.

Recanalization of acute and subacute venous and synthetic bypass-graft occlusions with a mechanical rotational catheter

PURPOSE

Percutaneous mechanical thrombectomy (PMT) is now established as an alternative treatment of acute arterial occlusions in addition to fibrinolysis and surgical thrombectomy. The objective of this retrospective study was the investigation of a rotational atherothrombectomy catheter in terms of safety and efficacy in the treatment of acute and subacute femoropopliteal bypass occlusions.

MATERIALS AND METHODS

Forty-two patients (average age 65.8 ± 9.1 years) with acute (<14 days [n = 31]) and subacute (14-42 days [n = 11]) femoropopliteal bypass occlusions were treated consecutively with a rotational debulking and removal catheter (Straub Rotarex). The average occlusion length was 28.4 ± 2.9 (24-34) cm. Thirty-four (81%) patients underwent venous bypass, and 8 (19%) patients underwent polytetrafluoroethylene bypass.

RESULTS

The technical success rate was 97.6% (41 of 42). In 1 patient, blood flow could not be restored despite the use of the atherothrombectomy system. The average catheter intervention time was 6.9 ± 2.1 (4-9) min. Ankle-brachial index increased from 0.39 ± 0.13 to 0.83 ± 0.11 at discharge and to 0.82 ± 0.17 after 1 month (p < 0.05). There were a total of 2 (4.8%) peri-interventional complications: One patient developed a distal embolism, which was successfully treated with local lysis, and another patient had a small perforation at the distal anastomosis, which was successfully treated with a stent.

CONCLUSION

PMT with the Rotarex atherothrombectomy catheter represents a safe and effective option in the treatment of acute and subacute femoropopliteal bypass occlusions because it can quickly restore blood flow.

Upper-limb thrombo-embolectomy: national cohort study in Denmark

OBJECTIVES

We investigated the incidence of thrombo-embolectomy in upper-limb and prognosis with respect to arm amputation, stroke and death.

METHODS

We performed a national cohort study of individuals, aged 40-99 years, and undergoing first-time thrombo-embolectomy in the brachial, ulnar or radial artery in Denmark from 1990 to 2002. The data were retrieved from the National Vascular Registry and from the National Registry of Patients and the Civil Registration System. Patients were followed until 2006 to ascertain the occurrence of amputation and stroke and until 2007 with respect to death.

RESULTS

In total, 1377 incident cases of thrombo-embolectomy were registered, comprising 504 (36.6%) males with a mean age of 72.0 (standard deviation (SD) 12.4) years and 873 (63.4%) females with a mean age of 77.2 (SD 11.7) years. Incidence was 3.3 (95% confidence interval (CI): 3.1-3.7) for males and 5.2 (95% CI: 4.9-5.6) for females per 100000 person-years. After thrombo-embolectomy, upper-limb amputation was performed in 11 (incidence 2.2%; 95% CI: 1.2-3.4) males and 31 (3.6%; 95% CI: 2.5-4.9) females. Age- and sex-specific risk of stroke was 2-16 times higher, and risk of death 3-11 times higher, than in the general population.

CONCLUSIONS

Upper-limb thrombo-embolectomy is associated with an increased risk of limb amputation, stroke and death.

Long-term outcome following thrombembolectomy in the upper extremity

OBJECTIVES

To evaluate short- and long-term mortality and morbidity in patients that were treated for acute upper extremity ischemia.

DESIGN

Single center retrospective study.

PATIENTS

A consecutive series of 148 patients who were admitted with a diagnosis of acute ischemia of the upper extremity during an 11-year period.

METHODS

All charts were reviewed retrospectively and 96% of all survivors participated in clinical follow-up.

RESULTS

The median age was 78 years and 64% of patients were females. The 30-day mortality was 8% and the overall 5-year survival 37%. The observed mortality during the follow-up period was significantly higher than expected. Survival was not significantly different in patients who received anticoagulant drugs following discharge from the hospital. The duration of ischemia did not significantly influence long-term arm-function.

CONCLUSIONS

Acute embolic episodes in the upper extremity primarily occur in elderly and the peri-operative mortality is high. Mortality following discharge from the hospital remains significantly higher than that of the background population.

Adjunctive techniques in percutaneous mechanical thrombectomy

Percutaneous mechanical thrombectomy is an established method in interventional radiology and refers to the removal of acute embolic or thrombotic occlusive material in arteries, veins, or vascular grafts using percutaneous transluminal methods. However, initial complete removal of occlusive material can be achieved only in a minority of patients. The amount of removed material varies with the age and composition of the occlusive material. To achieve sufficient revascularization, adjunctive use of a variety of percutaneous endovascular recanalization techniques is necessitated. Additional treatment with local intra-arterial fibrinolysis, balloon angioplasty, stent implantation, endoluminal atherectomy, and other measures results in primary technical success rates of 70% to 100% for revascularization of acutely occluded vessels. The above-mentioned different techniques should not be viewed as competitive treatment modalities, rather a synergistic approach should be offered. The aim of this report is to review different adjunctive techniques in percutaneous mechanical thrombectomy with emphasis on techniques, mechanisms of action, experimental and clinical results, potential complications, and their potential role in view of clinical pathways to treat acute limb ischemia.

Acute occlusion of popliteal and/or tibial arteries: the value of percutaneous treatment

OBJECTIVES

to describe early and mid-term results with a percutaneous therapeutic protocol including thromboaspiration, thrombolysis, and correction of the underlying lesion by PTA.

METHODS

thirty-three consecutive selected patients with recent (<1 month) reversible acute ischaemia associated with popliteal and/or tibial occlusion were studied. The primary endpoints were technical success (defined as residual mural thrombus less than 20% of the lumen and the presence of at least one tibial artery on angiogram), patient survival and limb salvage at 1 and 12 months. Secondary endpoints included complications, primary, assisted primary and secondary patency determined by duplex scan at 1, 6 and 12 months.

RESULTS

technical success was achieved in 27 patients (82%). Twenty patients were treated by thrombo- aspiration+/-thrombolysis only, and seven required additional PTA (26%). In six patients (18%), percutaneous techniques failed, and embolectomy was performed in two, bypass in one and major amputations in three (9%). For the entire series, the survival rate was 100% at 1 month and 94% at 1 year. The limb salvage rate was 91% at 1 month and 1 year. The cumulative primary patency, assisted primary patency and secondary patency rates were 81%, 81% and 86% respectively at 1 month and 66%, 72% and 77%, respectively, at 12 months. Early complications occurred in 10 patients (30%): five groin haematomas (15%), four compartment syndromes (12%) and one haemoglobinuria (3%).

CONCLUSION

percutaneous techniques offer excellent early and mid-term results in selected patients presenting with acute ischaemia with popliteal and/or tibial arteries occlusion.

Mid-term follow-up after percutaneous hydrodynamic thrombectomy in lower limb ischemia: initial experience with two-dimensional MR imaging and three-dimensional MR angiography

PURPOSE

To assess noninvasively mid-term patency, reocclusion, and mid-term changes of the arterial wall after percutaneous hydrodynamic thrombectomy in patients with acute lower limb ischemia using magnetic resonance (MR) imaging/MR angiography (MRA).

MATERIALS AND METHODS

Arterial wall and luminal changes were evaluated in 16 patients (10 men, six women; mean age, 70 years), with a minimum follow-up of 12 months after percutaneous thrombectomy with a hydrodynamic catheter for acute lower limb ischemia (embolic, n = 5; thrombotic, n = 11). Adjunctive PTA was performed in 44%. The mean follow-up was 23 months +/- 7.6 (range, 12-33 months). MR imaging and MRA were performed on a 1.0 T system using an extremity coil and two-dimensional (2D) time-of-flight, turbo spin echo, 2D gradient echo, and contrast enhanced three-dimensional (3D) gradient echo sequences.

RESULTS

In one patient, a complete reocclusion was noted and, in two patients, a hemodynamically insignificant restenosis (< or = 50%) was identified with MR imaging. This was in accordance with color flow duplex sonography, physical examination, ankle/brachial index measurements, and the treadmill test. The MR morphometry documented an increase of the entire vessel area from 48.9 mm2 +/- 3.3 (control segments) to 55.5 mm2 +/- 2.8 at the treated segments (+13.3%; P < .05). The vessel wall area increased from 31.7 mm2 +/- 1.8 to 39.4 mm2 +/- 2.3 (+24.4%; P < .05). The mean area stenosis grade was 12%.

CONCLUSION

MR imaging with use of morphometric analysis is a possible tool to noninvasively determine the mid-term patency and restenosis/reocclusion and remodeling process after percutaneous thrombectomy and other interventional procedures.

Two-year follow-up after acute thromboembolic limb ischaemia: the importance of anticoagulation

BACKGROUND

evidence on the effectiveness and usage of long-term anticoagulant therapy after acute thromboembolic limb ischaemia is very sparse. This study correlated medical events with administration of warfarin.

METHOD

during a three-month audit in 1996, 287 patients with embolism or thrombosisin situ survived for 30 days, and 214 (75%) were reviewed by questionnaires returned from clinicians throughout the United Kingdom. Minimum follow-up was two years.

RESULTS

thirty-five per cent had died. Recurrent acute limb ischaemia was reported in 11%, arterial intervention in 11%, and major amputation in 12%. Warfarin was given initially to 57% patients, but at follow-up only 43% were still taking warfarin (p<0. 05); reasons for stopping anticoagulation were often unknown. Recurrent limb ischaemia was less common in patients given warfarin initially (7% versus 17%) and still taking warfarin (3% versus 19%) -p;<0.05. Amputation was also less common in patients given warfarin initially (5% versus 21%) and still on warfarin (3% versus 21%) -p;<0.05.

CONCLUSION

long-term oral anticoagulation was associated with reduced risk of recurrent limb ischaemia and amputation, but more research is needed to define the benefits and risks, especially for thrombosisin situ. Clinicians should give clear advice about anticoagulation when patients are discharged from hospital.

The surgical management of acute limb ischaemia due to native vessel occlusion

OBJECTIVES

Data from the STILE study have indicated that for patients with subacute limb ischaemia due to native vessel occlusion, surgery is both more effective, and durable than thrombolysis. The purpose of this study was to evaluate the outcome of an aggressive surgical approach in patients presenting with acute limb-threatening ischaemia.

DESIGN

Details of patients presenting with salvageable acute limb ischaemia due to native artery occlusion over a 6-year period in a University hospital vascular unit setting were obtained from the vascular audit and the outcome of the surgical management of these patients was analysed.

RESULTS

One hundred and seventy-four consecutive patients underwent surgery for acute native vessel limb ischaemia (76% lower, 24% upper limb). Fogarty thrombectomy or embolectomy was initially performed in 153 (89%) patients. Of these, 37 (24%) immediately underwent a further procedure: 28 (18%) had on-table thrombolysis and 14 (9%) underwent vascular reconstruction. Twenty-six patients (15%) underwent further limb salvage surgery within 30 days. Life table analysis demonstrated a limb salvage rate of 88% and 76% at 30 days and 2 years, respectively. Patient survival was 75% and 48% at the same time intervals.

CONCLUSIONS

These results demonstrate that a role for aggressive surgical intervention still exists, resulting in high limb salvage rates.

Operative mortality and long-term survival of patients operated on for acute lower limb ischaemia

OBJECTIVES

To investigate the operative mortality and long-term survival of patients with lower limb embolism or acute thrombosis.

DESIGN

A retrospective survival analysis.

MATERIALS

Eighty patients with acute thrombosis treated by bypass and 192 patients with embolism treated by embolectomy during the years from 1985 to 1996 were studied.

METHODS

The observed survival rates were calculated with the product limit method. The expected survival rates were estimated from death-rate tables. The standard mortality rate was compared over a 5-year follow-up.

RESULTS

The patients treated for embolism had an operative mortality of 17% and a 5-year survival rate of 17%, which was significantly lower than the expected rate of 62%. Those treated for acute thrombosis had an operative mortality of 14% and a 5-year survival rate of 44%. This was significantly higher than for the embolism group, but significantly lower than the expected rate of 74%. Both groups had a standard mortality rate of 2.2 at 5 years.

CONCLUSION

Patients with acute ischaemia have a poor short-term and long-term prognosis. The patients treated for embolism are older and they have a shorter life expectancy than those treated for acute thrombosis. The standard mortality rate of the two groups appears similar.

District hospital management and outcome of critical lower limb ischaemia: comparison with national figures

OBJECTIVE

To compare local with national management and outcome of critical limb ischaemia (CLI).

DESIGN

Use of nationally identified management groups for allocation of local patients. These were: revascularisation, primary major amputation, medical/minor surgical treatment and no treatment.

MATERIAL

All admissions with CLI for the 5 year period January 1990 to December 1994.

RESULTS

Local compared to national revascularisation of 43% vs. 63%, primary major amputation of 18% vs. 16%, medical/minor surgical of 20% vs. 8% and no treatment of 19% vs. 13%. During the fifth year 59% of limbs were revascularised. Fewer patients died in hospital locally (8% vs. 14%), particularly the group having no treatment (9% vs. 44%), but by 6 months only 58% of this group had survival. Local compared to national hospital limb salvage of 76% vs. 68% and patency of revascularisation of 86% vs. 75%. Of the revascularisations a low rate of percutaneous transluminal angioplasty (PTA) was noted locally (16% vs. 34%) and more grafts were being taken to above-nee popliteal artery (26% vs. 13%). Crural grafts were revised to a secondary amputation in 42%.

CONCLUSION

Although differences were observed between local and national management of CLI, overall acceptable outcomes were being obtained locally despite there being an identifiable deficiency in the availability of radiological services with regard to urgent PTA and thrombolysis.

Management cost of acute limb ischaemia

The cost of attempting limb salvage in patients who presented with acute lower limb ischaemia was recorded prospectively for 20 months. Seventy-five patients were admitted during the study; 45 were treated primarily by radiological intervention and 18 had primary surgery. The remainder were treated conservatively. Patients who had primary surgery required fewer visits to the operating theatre than those who had primary thrombolysis, but there was no difference in the total time that the theatre or radiology suite was occupied: median 2.3 (10th centile range 1.5-5.0) h and 3.0 (2.0-5.0) h respectively. Median (range) cost of disposables for performing surgery was Pounds 82 (58-169) and for thrombolysis was Pounds 407 (252-596). When the costs of using the theatre or radiology suite were included, the costs of both treatments were similar: surgery Pounds 683 (309-1438) and lysis Pounds 861 (611-1244). Median (10th centile range) inpatient stay for surgical patients was 9 (3-18) days and for those having thrombolysis 11 (2-29) days. Median (10th centile range) costs for bed occupancy were similar in both groups: surgery Pounds 2497 (643-9115) and lysis Pounds 2189 (902-6020). Mean cost for attempting limb salvage by surgery was Pounds 3429 (1094-10065) compared with Pounds 3230 (1543-8353) for thrombolysis.

Amputation risk and survival after embolectomy for acute arterial ischaemia. Time trends in a defined Swedish population

OBJECTIVES

To assess the outcome of embolectomy over an 19 year period.

METHODS

Time trends in the outcome of acute arterial thrombo-embolectomy of the extremities were analysed in a population-based cohort of 1190 patients operated on between 1965-83.

RESULTS

A total of 262 (22%) initial amputations were performed. The limb salvage rates at 5 years postoperatively were lower between 1975-79 (61%) than between 1965-69 (81%). A proportional hazards model revealed a relative hazard (RH) of amputation of 2.2 (95% confidence interval (CI) 1.3-3.3) for 1975-79 compared with 1965-69. Operation at any district hospital entailed a 70% higher risk of amputation (RH 1.7; 95% CI 1.3-2.5) compared with the University hospital. The relative survival rate at 5 years postoperatively decreased towards the end of the study period (33% between 1975-79 compared with 43% between 1965-69). Younger age-groups had a considerably lower risk of death in the University hospital compared with the county and district hospitals.

CONCLUSIONS

Contrary to the results in other hospital based reports no improvement in amputation or survival rates since 1965 could be demonstrated in this large series with no patient selection.

Vascular emergencies: what's in season?

Seasonality in ischaemic coronary artery disease is well documented with a winter/summer variation the commonest pattern. The influence of seasonal variation on events in other vascular territories is less well documented. The incidence of ruptured abdominal aortic aneurysm and emergency lower-limb ischaemia was analysed on a monthly basis over a 5-year period. A total of 372 ruptured abdominal aortic aneurysms occurred with a peak incidence in spring and autumn; however, no seasonal pattern was seen in the rate of emergency admissions with lower-limb ischaemia (n = 606). The explanation for this seasonal pattern in ruptured aneurysms is unknown. The haemodynamic adjustments to changes in climate require further study.

Arterial emboli of the lower limbs: analysis of risk factors for mortality and amputation. Association Universitaire de Recherche en Chirurgie

To evaluate risk factors for mortality and amputation after arterial embolism of the lower limbs, we reviewed the records of 397 patients (201 men [mean age 69 +/- 14 years] and 196 women [mean age 79 +/- 12 years]) who were enrolled in a prospective study. The degree of ischemia was rated as follows: grade I in 26% of patients, grade II in 46%, and grade III in 27%. Among patients with complete obstruction, the emboli were located above the inguinal ligament in 213 limbs (46%), in the superficial or popliteal artery in 196 (43%), and at the infrapopliteal level in four (3%). The emboli were bilateral in 59 cases (15%). In 11% of patients the emboli also involved either an upper limb or a visceral or cerebral artery. The origin of the embolus was the heart in 55% of patients, an artery in 12%, and was unknown in the remaining cases. Two hundred two patients (50%) had arterial fibrillation, 33 (8%) had cardiac conduction abnormalities, 186 (47%) had ischemic heart disease, 55 (14%) had valvular heart disease, and 43 (11%) had cardiac insufficiency. The in-hospital mortality rate was 15% (n = 60) and major amputations or severe ischemic sequelae were observed in 23% (n = 91). Logistic regression analysis revealed four independent preoperative factors associated with a significantly higher risk of death: associated visceral emboli with a relative risk (RR) of 6.7 (p < 0.001), invalidism with an RR of 4.3 (p < 0.001), cardiac insufficiency with an RR of 2.4 (p = 0.001), and creatinemia > 180 ml/L with an RR of 2.1 (p = 0.01). The variables associated with an increased risk of amputation were invalidism (p = 0.001), severity of ischemia (p = 0.001), infrapopliteal location of the embolus (p = 0.001), delay of more than 12 hours before treatment of severe ischemia was initiated (p = 0.01), failure to restore arterial patency (p = 0.001), and postoperative cardiac complications (p = 0.01).

Intraoperative streptokinase: a useful adjunct to balloon-catheter embolectomy

Intraoperative thrombolysis was attempted in 31 acutely ischaemic legs after operative arteriography had demonstrated residual distal thrombus or occlusion following balloon-catheter thromboembolectomy. There were 30 patients, 16 men and 14 women, aged 43-82 (median 73) years. The indication for operation was severe ischaemia with sensorimotor loss in 25 limbs, failed percutaneous thrombolysis in three and acute graft occlusion in three. A total of 21 perfemoral, 11 perpopliteal and four graft embolectomies were initially performed. Following arteriography, 100,000 units streptokinase was infused down the isolated distal arterial tree over 30 min and arteriography repeated. Complete lysis was achieved in 11 legs (35 per cent) and partial lysis in 12 (39 per cent). Additional procedures required included six operative angioplasties and six bypass grafts. After operation pedal pulses were restored in 14 limbs (45 per cent), with a viable leg in 23 cases (74 per cent) at the time of patient discharge or death. There were five wound haematomas but no evidence of systemic fibrinolysis. Four amputations were required, none in the group undergoing successful lysis, and there were seven deaths, five from cardiac disease. Arteriography after balloon-catheter embolectomy is essential to detect residual thromboembolus and intraoperative streptokinase appears to be a safe and effective way of removing this.

Preoperative assessment of the risk for cardiac death following thrombo-embolectomy for acute lower limb ischaemia

Cardiac monitoring and the selective use of initial non-operative management is reported to reduce the high mortality rate in patients with acute lower limb ischaemia. Early estimation, prior to selection of initial therapy, of the risk for intraoperative or postoperative cardiac death following thrombo-embolectomy is therefore important. The aim of this prospective multi-centre study was to develop a simple and clinically useful index for assessment of the risk of post-operative cardiac death. Patients judged to need thrombo-embolectomy for acute lower limb ischaemia were evaluated on admission for routine clinical, cardiac and limb ischaemia parameters that could be related to cardiac function and these parameters compared to postoperative cardiac outcome. Sixteen per cent of the 117 patients died from intraoperative or postoperative cardiac complications. Analysis revealed five admission parameters that significantly and independently predicted a high risk for cardiac death: mean arterial blood pressure below 90 mmHg, clinical sign(s) of cardiac decompensation, ischaemia affecting the thigh, haemoglobin concentration exceeding 140 gl-1, and a history of a myocardial infarction in the previous 4 weeks. Definition of risk points for each risk factor allowed a simple classification of each patient into one of three significantly different cardiac risk classes with cardiac death rates of 6 +/- 3%, 27 +/- 8% and 75 +/- 16%, respectively. More than two thirds of the patients belonged to the low risk group. The described risk index provides a tool for preoperative assessment of the cardiac death risk associated with early thrombo-embolectomy in patients with acute lower limb ischaemia.

Risk factors for early lower limb loss after embolectomy for acute arterial occlusion: a population-based case-control study

To identify risk factors for lower limb loss after arterial embolectomy a cohort of 1189 patients was studied. Detailed data were obtained for 165 patients who underwent a major amputation within 30 days of embolectomy and for 165 matched controls. The amputation risk was increased in patients with two or more myocardial infarctions (odds ratio (OR) 3.1, 95 per cent confidence interval (CI) 0.8-11.2), chronic ischaemia (OR 2.1, CI 0.9-4.9), long duration of symptoms (OR 4.3, CI 1.9-9.6, for greater than or equal to 25 h versus less than or equal to 6 h) or postoperative heart failure (OR 3.4, CI 1.8-6.5). Reduced risks were found in association with acute myocardial infarction (OR 0.3, CI 0.1-0.9) and postoperative anticoagulation treatment with warfarin (OR 0.3, CI 0.1-0.9). The independent prognostic value of chronic ischaemia and symptom duration, and the beneficial effect of postoperative anticoagulation gained additional support in multivariate analysis. We conclude that the risk of early amputation after arterial embolectomy or thrombectomy can be predicted by several clinical characteristics.

Five-year vascular audit from a district hospital

Vascular patients under the care of one surgeon over a 5-year period have been reviewed, from computer-based discharge records, with regard to in-hospital measures of outcome to determine whether or not surgery was being performed to an acceptable standard. Out of 466 procedures, 30 per cent of patients had at least one complication, 14 per cent had further surgery and 9 per cent died. Outcome was examined within the following treatment groups: aorto/iliac aneurysm, aortofemoral bypass, femoroproximal popliteal bypass, femorodistal popliteal bypass, femorocrural bypass, embolectomy and percutaneous transluminal angioplasty. Patients having below-knee bypass surgery were found to have an unacceptably high rate of complications, reoperations and amputations. An overall rate of reoperation for postoperative bleeding of 5 per cent was also considered to be high. With these exceptions, it was concluded that the surgery was being performed to an acceptable standard, but that comparative audit of this type remained difficult while there was a deficiency of national statistics against which the work of individual surgeons could be judged.

Morbidity and mortality in acute lower limb ischaemia: a 5-year review

A series of 204 consecutive patients with acute lower limb ischaemia was treated over a 5-year period in a Regional Vascular Unit. The mean age was 70 years, with a range of 41-98 and a female to male ratio of 1:0.94. Eighty-eight percent were treated by operation. Twenty-one had simultaneous vascular reconstructive procedures. Fifty-three patients died within 30 days (mortality rate 26%), and 12 required major amputation. Of these, four died resulting in a limb salvage rate of 95% in the survivors. An analysis of factors affecting outcome has shown increasing age, level of occlusion, recent myocardial infarction, pre-existing peripheral arterial disease and cardiopulmonary functional class to be major determinants of morbidity and mortality.