A. Nasim

Surgical Management of 671 Abdominal Aortic Aneurysms: A 13 Year Review from a Single Centre

OBJECTIVE To audit the results for abdominal aortic aneurysm (AAA) repair from a single centre over a 13 year period. DESIGN Retrospective survey. SETTING Vascular unit of a major teaching hospital. MATERIALS Six hundred and seventy-one consecutive patients divided into two groups: group A (1981-87) and group B (1988-93). CHIEF OUTCOME MEASURES Mortality rates, cause of death and major complications in patients undergoing elective, urgent and ruptured AAAs. RESULTS Elective repair was performed in 313 (47%) patients, urgent repair in 80 (12%) and emergency repair for rupture in 278 (41%). A vascular surgeon performed the procedure in 94% of patients. The overall mortality was 21 patients in the elective group (6.7%), 13 in the urgent group (16%) and 148 in the ruptured group (53%). Mortality rates have not fallen during the study period but more patients in group B had ischaemic heart disease. Sixty patients (9%) required further operative procedures on 66 occasions: 24 elective cases (8%), 8 urgent cases (10%) and 28 ruptured cases (10%). There were 23 deaths in these 60 patients (38%) who underwent re-operation (5 elective, 2 urgent and 16 ruptured). Major postoperative complications included cardiac events in 212 (32%) patients, respiratory failure in 202 (30%) and renal failure in 90 (13%). Major causes of death included cardiac disease in 67 patients (37%), cardiac disease with coagulopathy in 22 (12%) and cardiac disease with respiratory failure in 16 (9%). Logistic regression analysis showed that in the elective group, cardiac or renal failure were significantly associated with death; and in the ruptured group cardiac, respiratory or renal failure were significantly associated with death. CONCLUSIONS More high risk patients with ischaemic heart disease are undergoing AAA repair. Postoperative cardiac, respiratory or renal failure are significant causes of death in AAA patients.

Ultrasound Measurement of Aortic Diameter in a National Screening Programme

OBJECTIVE Currently there is no universally accepted standard for ultrasound measurement of abdominal aortic aneurysm (AAA). The aim was to investigate the reliability and reproducibility of inner to inner (ITI) versus outer to outer (OTO) ultrasound measurement of AAA diameter. METHODS A prospective study design was used to collect 60 random images of aorta (1.4-7.1 cm). Inner and outer wall diameter measurements were then performed by 13 qualified AAA screening technicians and 11 vascular sonographers. RESULTS The mean (range) diameter for all 60 aortas by ITI was 3.91 cm (1.39-6.80) and by OTO was 4.18 cm (1.63-7.09), a significant mean difference of 0.27 cm (95% CI: 0.23-0.32 cm). The reproducibility coefficients for differences between technicians were 0.30 cm (95% CI: 0.24-0.36) for ITI and 0.42 cm (95% CI: 0.35-0.49) for OTO indicating significantly better repeatability using ITI. Finally, 15 images were measured twice in random order by all screeners and sonographers. For AAAs > 5 cm, repeatability was significantly better with ITI than OTO (0.14 vs. 0.21; p = 0.016). CONCLUSION There was the expected difference in AAA diameter between the two methods (0.27 cm). However, ITI wall method was measurably more reproducible.

Percutaneous Transluminal Angioplasty in the Treatment of Critical Limb Ischemia

Purpose: To assess the role of percutaneous transluminal angioplasty (PTA) to treat critical limb ischemia (CLI) and to relate the changing experience with endovascular treatment of this condition in a major vascular unit. Methods: A prospective study was performed involving 110 consecutive patients (57 women; mean age 76 years, range 57–99) undergoing balloon angioplasty for critical limb ischemia in 133 limbs. Outcome at 1 year was examined by case note review or questionnaire to determine survival, amputation-free survival, limb salvage, and CLI recurrence. Results: Technical success was achieved in 105 (79%) of 133 limbs; the overall complication rate was 20% (3.8% major, 16.2% minor). The median follow-up was 15 months (minimum 12). The 12-month limb salvage rate by life-table analysis was 88%. Patients with an initially successful angioplasty had an extremely good outcome (95% 1-year limb salvage). In contrast, the 28 patients with failed angioplasty fared very poorly; a major amputation was required in 10, and death occurred in another 9, leaving only 9 survivors with limbs intact at 1 year. Conclusions: The results of this study justify the continuing use of PTA as first-line treatment for critical limb ischemia.

Changing epidemiology of abdominal aortic aneurysms in England and Wales: older and more benign?

Background— Recent studies from Australia, New Zealand, and Sweden have reported declines in abdominal aortic aneurysm (AAA) incidence, prevalence, and mortality. This finding may have important implications for screening programs. This study determined trends in AAA incidence and mortality in England and Wales. Methods and Results— Cause-specific mortality data for England and Wales were obtained from UK Office for National Statistics, and hospital admissions and procedures data for England were obtained from Hospital Episode Statistics from 2001 to 2009. Poisson regression models were constructed to estimate the relative change over time. Age-standardized rates for AAA mortality in England and Wales fell significantly by 35.7% from 2001 to 2009, which was largely due to a 35.3% drop in age-standardized ruptured AAA deaths. During the same period, ruptured AAA admissions and emergency AAA repairs in England declined by 29.3% and 35.5%, respectively. In contrast, nonruptured AAA admissions remained static, and nonemergency AAA repairs increased by 17.2%. The average ages for hospital admissions for nonruptured AAAs and ruptured AAAs increased by 0.19 years of age per annum (P<0.001) and 0.09 years of age per annum (P<0.001), respectively. Nonruptured AAA admissions increased by 21.4% in age band 75 years or more but declined by 11.7% in ages <75 years. Conclusions— AAA mortality, ruptured AAA admission, and emergency AAA repair have declined in England and Wales. However, nonruptured AAA admission has remained steady, with an increasing rate in older population offsetting a decreasing rate in younger population. This suggests a shift in AAA presentation to the older population. Present screening strategies may need reassessment to include consideration for increasing the age at which to screen men for AAAs.

Results of surgery and angioplasty for the treatment of chronic severe lower limb ischaemia

OBJECTIVE To aims of this study was to assess and compare the efficacy of PTA and surgery in the treatment of severe lower limb ischaemia. DESIGN Prospective 12-month study of 180 consecutive patients with severe chronic lower limb ischaemia. METHODS PTA was used as first line therapy whenever possible and appropriate. Surgical revascularisation, primary amputation and conservative therapy were used in eh remaining patients. Patient survival and limb salvage were derived using life table analysis. RESULTS Revascularisation was attempted in 135 (75%) patients, with PTA in 82 (46%), surgery in 19 (27%) and a combination of both in four (2%). Overall 12-month survival and limb salvage was 75% and 71%, respectively. Surgery and PTA had significantly higher survival rates (91% and 78%) than primary amputation or conservative therapy (57% and 52%) (p < 0.0001 log rank test). Revascularisation with either surgery or PTA achieved the same limb salvage rate of 76%. CONCLUSION A large proportion of patients with severe chronic lower limb ischaemia can be managed by PTA. THis management strategy produces a clinically effective outcome at 1-year.

Dual Antiplatelet Therapy Prior to Carotid Endarterectomy Reduces Post-operative Embolisation and Thromboembolic Events: Post-operative Transcranial Doppler Monitoring is now Unnecessary

BACKGROUND Thrombotic stroke following carotid endarterectomy (CEA) is preceded by high-grade embolisation (detected using transcranial Doppler (TCD)) and can be prevented by incremental doses of Dextran. However, this strategy is labour intensive and Dextran manufacture has now ceased. A randomised trial has suggested that a single 75 mg dose of Clopidogrel (administered the night before surgery in addition to daily 75 mg Aspirin) significantly reduces post-CEA embolisation. We hypothesized that this model of dual antiplatelet therapy might significantly reduce the need for adjuvant Dextran therapy. METHODS Retrospective audit of prospectively acquired data in 297 patients undergoing CEA between 01.08.2006 and 30.07.2009. All received routine Aspirin (75 mg daily) in addition to a single 75 mg dose of Clopidogrel the night before surgery. All underwent completion angioscopy and those with a temporal window (n = 270) underwent intra- and post-operative TCD monitoring. RESULTS High rate embolisation requiring Dextran (>25 emboli in any 10 min period) occurred in only 1/270 patients (0.4%), significantly less than the 3.2% rate in historical controls where Clopidogrel was not administered. There were no peri-operative deaths, but 3/297 patients suffered non-disabling strokes (intra-operative extension of a pre-existing deficit, haemorrhage into lentiform nucleus after hypertensive crisis, contralateral embolic stroke). The overall 30-day death/stroke rate (1.0%) was not-significantly lower than the 2.6% rate observed in the preceding 821 patients. CONCLUSIONS 75 mg Clopidogrel administered the night before surgery (in addition to daily 75 mg Aspirin) was associated with a significant reduction in post-operative embolisation and Dextran utilisation. No ipsilateral thromboembolic ischaemic events occurred in this series. As a consequence of this audit, one dose of 75 mg Clopidogrel will continue to be given pre-operatively (in addition to daily 75 mg Aspirin) and routine post-operative TCD monitoring has now ceased.

Trends in Abdominal Aortic Aneurysms: a 13 year review

AIM To assess changing trends of abdominal aortic aneurysms 1979-1991. DESIGN Retrospective study from the Leicestershire Health Authority. RESULTS 727 patients with abdominal aortic aneurysm were treated. Of these 56.4% were admitted for elective repair and 43.6% presented with rupture. There was a significant increase in the number of ruptured aortic aneurysms over this period despite an increase in the number of elective repairs. The overall 30-day mortality of elective repair (including patients with symptomatic but non-ruptured aneurysms) was 8.8%. The overall 30-day mortality of ruptured aneurysms (including patients who were deemed medically too unfit for surgery) was 57.7%. There has been no significant change in elective and ruptured mortality over the study period. There was a significant increase in the median age of patients (69.5 yrs in 1979 to 74 yrs in 1991). CONCLUSION The increasing incidence of abdominal aortic aneurysms may reflect better diagnostic methods, greater clinical awareness of the condition and increase in the proportion of elderly people in the population.

Procedural Risk Following Carotid Endarterectomy in the Hyperacute Period after Onset of Symptoms

OBJECTIVES There have been concerns that performing carotid endarterectomy (CEA) in the hyperacute period after onset of a transient ischaemic attack (TIA) or stroke may be associated with a significant increase in the procedural risk that could offset any long-term benefit to the patient. The aim of this audit was to determine the 30-day risk of stroke/death after CEA in symptomatic patients, stratified for delay from the most recent neurological event, mode of presentation, and age. METHODS Retrospective audit in 475 recently symptomatic patients between October 1, 2008, and April 24, 2013. RESULTS Forty-one patients (9%) underwent surgery <48 hours of their most recent event, with a 30-day death/stroke rate of 2.4% (1/41). The procedural risk was 1.8% in 167 patients who underwent surgery within 3-7 days (3/167), falling to 0.8% in 133 patients who underwent surgery between 8 and 14 days (1/133) and 0.8% in 134 patients whose surgery took place after >14 days had elapsed (1/134). Overall, 208 (44%) underwent surgery within 7 days of their most recent neurological event (30-day risk = 1.9%), while 341 (72%) underwent CEA within 14 days (30 day risk = 1.5%). There was no evidence of any systematic differences in procedural risk by operating in the hyperacute period relating to mode of presentation (TIA, stroke, amaurosis) or age (<80 years; >80 years). CONCLUSIONS This audit found no evidence that the procedural risk was increased when CEA was performed in the hyperacute period whether this time period was defined as <48 hours, <7 days, or <14 days.

ENDOVASCULAR REPAIR OF AN INFLAMMATORY AORTIC ANEURYSM

A 60-year-old man presented with a 3 month history of abdominal pain, back pain and 10 kg weight loss. Abdominal examination suggested an abdominal aneurysm. A contrast enhanced CT scan demonstrated a 7.3 cm aneurysm surrounded by a rim of soft tissue consistent with a peri-aneurysmal inflammatory response. The left ureter was involved in the inflammatory process with resultant hydronephrosis. Preoperative blood analysis revealed a plasma viscosity of 2.05 (normal <1.73) a C-Reactive protein (CRP) of 3.6 (normal <1.0), and a positive antinuclear antibody titre of 1:64. The aneurysm was repaired endovascularly using a tapered prosthesis consisting of a Palmaz balloon expandable stent sutured to a pre-expanded PTFE graft as previously described. 1 The patient made an uneventful postoperative recovery and was discharged home on the 7th day. The patient was reviewed at 6 weeks, 6 months and 1 year. CT scanning confirmed aneurysm exclusion,

Closing the Loop: A 21-year Audit of Strategies for Preventing Stroke and Death Following Carotid Endarterectomy

The objective of this review was to identify causes of stroke/death after carotid endarterectomy (CEA) and to develop transferable strategies for preventing stroke/death after CEA, via an overview of a 21-year series of themed research and audit projects. Three preventive strategies were identified: (i) intra-operative transcranial Doppler (TCD) ultrasound and completion angioscopy which virtually abolished intra-operative stroke, primarily through the removal of residual luminal thrombus prior to restoration of flow; (ii) dual antiplatelet therapy with a single 75-mg dose of clopidogrel the night before surgery in addition to regular 75 mg aspirin which virtually abolished post-operative thromboembolic stroke and may also have contributed towards a decline in stroke/death following major cardiac events; and (iii) the provision of written guidance for managing post-CEA hypertension which was associated with virtual abolition of intracranial haemorrhage and stroke as a result of hyperperfusion syndrome. The pathophysiology of peri-operative stroke is multifactorial and no single monitoring or therapeutic strategy will reduce its prevalence. Two of the preventive strategies developed during this 21-year project (peri-operative dual antiplatelet therapy, published guidance for managing post-CEA hypertension) are easily transferable to practices elsewhere.