Florian Dick

Chapter IV: Treatment of Critical Limb Ischaemia

Recommendations stated in the TASC II guidelines for the treatment of peripheral arterial disease (PAD) regard a heterogeneous group of patients ranging from claudicants to critical limb ischaemia (CLI) patients. However, specific considerations apply to CLI patients. An important problem regarding the majority of currently available literature that reports on revascularisation strategies for PAD is that it does not focus on CLI patients specifically and studies them as a minor part of the complete cohort. Besides the lack of data on CLI patients, studies use a variety of endpoints, and even similar endpoints are often differentially defined. These considerations result in the fact that most recommendations in this guideline are not of the highest recommendation grade. In the present chapter the treatment of CLI is not based on the TASC II classification of atherosclerotic lesions, since definitions of atherosclerotic lesions are changing along the fast development of endovascular techniques, and inter-individual differences in interpretation of the TASC classification are problematic. Therefore we propose a classification merely based on vascular area of the atherosclerotic disease and the lesion length, which is less complex and eases the interpretation. Lesions and their treatment are discussed from the aorta downwards to the infrapopliteal region. For a subset of lesions, surgical revascularisation is still the gold standard, such as in extensive aorto-iliac lesions, lesions of the common femoral artery and long lesions of the superficial femoral artery (>15 cm), especially when an applicable venous conduit is present, because of higher patency and limb salvage rates, even though the risk of complications is sometimes higher than for endovascular strategies. It is however more and more accepted that an endovascular first strategy is adapted in most iliac, superficial femoral, and in some infrapopliteal lesions. The newer endovascular techniques, i.e. drug-eluting stents and balloons, show promising results especially in infrapopliteal lesions. However, most of these results should still be confirmed in large RCTs focusing on CLI patients. At some point when there is no possibility of an endovascular nor a surgical procedure, some alternative non-reconstructive options have been proposed such as lumbar sympathectomy and spinal cord stimulation. But their effectiveness is limited especially when assessing the results on objective criteria. The additional value of cell-based therapies has still to be proven from large RCTs and should therefore still be confined to a research setting. Altogether this chapter summarises the best available evidence for the treatment of CLI, which is, from multiple perspectives, completely different from claudication. The latter also stresses the importance of well-designed RCTs focusing on CLI patients reporting standardised endpoints, both clinical as well as procedural.

Chapter V: Diabetic Foot

Ulcerated diabetic foot is a complex problem. Ischaemia, neuropathy and infection are the three pathological components that lead to diabetic foot complications, and they frequently occur together as an aetiologic triad. Neuropathy and ischaemia are the initiating factors, most often together as neuroischaemia, whereas infection is mostly a consequence. The role of peripheral arterial disease in diabetic foot has long been underestimated as typical ischaemic symptoms are less frequent in diabetics with ischaemia than in non-diabetics. Furthermore, the healing of a neuroischaemic ulcer is hampered by microvascular dysfunction. Therefore, the threshold for revascularising neuroischaemic ulcers should be lower than that for purely ischaemic ulcers. Previous guidelines have largely ignored these specific demands related to ulcerated neuroischaemic diabetic feet. Any diabetic foot ulcer should always be considered to have vascular impairment unless otherwise proven. Early referral, non-invasive vascular testing, imaging and intervention are crucial to improve diabetic foot ulcer healing and to prevent amputation. Timing is essential, as the window of opportunity to heal the ulcer and save the leg is easily missed. This chapter underlines the paucity of data on the best way to diagnose and treat these diabetic patients. Most of the studies dealing with neuroischaemic diabetic feet are not comparable in terms of patient populations, interventions or outcome. Therefore, there is an urgent need for a paradigm shift in diabetic foot care; that is, a new approach and classification of diabetics with vascular impairment in regard to clinical practice and research. A multidisciplinary approach needs to implemented systematically with a vascular surgeon as an integrated member. New strategies must be developed and implemented for diabetic foot patients with vascular impairment, to improve healing, to speed up healing rate and to avoid amputation, irrespective of the intervention technology chosen. Focused studies on the value of predictive tests, new treatment modalities as well as selective and targeted strategies are needed. As specific data on ulcerated neuroischaemic diabetic feet are scarce, recommendations are often of low grade.

Ten-year comparison of pericardial tissue valves versus mechanical prostheses for aortic valve replacement in patients younger than 60 years of age.

OBJECTIVE Aortic valve replacement using a tissue valve is controversial for patients younger than 60 years old. The long-term survival in this age group, the expected event rates during long-term follow-up, and valve-related complications are not clearly determined. METHODS From January 2000 to December 2009, overall survival, valve-related events, and echocardiographic outcomes were analyzed in all patients younger than 60 years of age, who underwent biologic aortic valve replacement. Patients who received a Perimount Carpentier-Edwards pericardial tissue valve (n = 103) were selected and compared with a propensity matched group of 103 patients who received aortic valve replacement using a mechanical bileaflet valve. The mean follow-up was 33 ± 24 months (range, 2-120), and the mean age at implantation was 50.6 ± 8.8 years (bioprosthesis, 55 ± 8.9 years; mechanical valve, 50 ± 8.6 years; P = .03). RESULTS Survival was significantly reduced in patients after biologic aortic valve replacement (90.3% vs 98%; P = .038). Freedom from all valve-related complications (bioprosthesis, 54.5%; mechanical valve, 51.6%; P = NS) and freedom from reoperation (bioprostheses, 100%; mechanical valve, 98%; P = NS) were comparable in both groups. The average transvalvular mean (11.2 ± 4.2 mm Hg vs 10.5 ± 6.0 mm Hg, P = .05) and peak (19.9 ± 6.7 mm Hg vs 16.7 ± 8.0 mm Hg, P = .03) gradients were greater after biologic aortic valve replacement. Regression of the left ventricular mass index was more pronounced after mechanical valve replacement (118.5 ± 24.9 g/m(2) vs 126.5 ± 38.5 g/m(2); P = NS). The echocardiographic patient-prosthesis mismatch was greater at follow-up after biological aortic valve replacement (0.876 ± 0.2 cm(2)/m(2) vs 1.11 ± 0.4 cm(2)/m(2); P = .01). Oral anticoagulation was a protective factor for survival among the bioprosthetic valve patients (P = .024). CONCLUSIONS In the present limited cohort of patients younger than 60 years old, biologic aortic valve replacement was associated with reduced mid-term survival compared with survival after mechanical aortic valve replacement. Despite similar valve-related event rates in both groups, the better hemodynamic performance of the mechanical valves and/or protective effect of oral anticoagulation seemed to improve the outcome. The transcatheter valve-in-valve intervention as potential treatment of tissue valve degeneration should not be considered the sole bailout strategy for younger patients because no evidence is available that this would improve the outcome.

Self-Made Pericardial Tube Graft: A New Surgical Concept for Treatment of Graft Infections After Thoracic and Abdominal Aortic Procedures

BACKGROUND The aim of this study was to evaluate a new surgical concept for the treatment of graft infections after operation or endovascular treatment of thoracic, thoracoabdominal, and abdominal aortic diseases. METHODS Between 2004 and 2011, 15 patients (mean age 72 ± 10 years, 87% men) with prosthetic graft or endovascular graft infection were treated with complete removal of the infected prosthetic material, extensive debridement of the surrounding tissues, and orthotopic vascular reconstruction with self-made xenopericardial tube grafts constructed from a patch. Perioperative and long-term outcomes were evaluated. RESULTS Perioperative mortality was 27% (n = 4). All deaths were due to multiorgan failure resulting from uncontrolled septicemia from the local infectious process. Mean observational follow-up was 24 months (5 to 83 months). Control computed tomographic scans showed normal findings at the operative site in all patients. Antibiotic treatment was continued for a mean of 6 months. Freedom from reinfection was 100%. Freedom from reoperation was also 100%. CONCLUSIONS Treatment of graft infections after operation or endovascular treatment of thoracic, thoracoabdominal, and abdominal aortic diseases by complete removal of the infected prosthetic material and extensive debridement as well as orthotopic vascular reconstruction using self-made xenopericardial tube grafts as neoaortic segments provides excellent results with regard to durability and freedom from reinfection and reoperation. This new concept is an additional alternative to cryopreserved homografts that extends the armamentarium for treating patients with these highly complex conditions.

Editor's Choice – Management of Descending Thoracic Aorta Diseases : Clinical Practice Guidelines of the European Society for Vascular Surgery (ESVS)

Editors Choice - Management of Descending Thoracic Aorta Diseases : Clinical Practice Guidelines of the European Society for Vascular Surgery (ESVS).

Chapter II: Diagnostic Methods

Non-invasive vascular studies can provide crucial information on the presence, location, and severity of critical limb ischaemia (CLI), as well as the initial assessment or treatment planning. Ankle-brachial index with Doppler ultrasound, despite limitations in diabetic and end-stage renal failure patients, is the first-line evaluation of CLI. In this group of patients, toe-brachial index measurement may better establish the diagnosis. Other non-invasive measurements, such as segmental limb pressure, continuous-wave Doppler analysis and pulse volume recording, are of limited accuracy. Transcutaneous oxygen pressure (TcPO(2)) measurement may be of value when rest pain and ulcerations of the foot are present. Duplex ultrasound is the most important non-invasive tool in CLI patients combining haemodynamic evaluation with imaging modality. Computed tomography angiography (CTA) and magnetic resonance angiography (MRA) are the next imaging studies in the algorithm for CLI. Both CTA and MRA have been proven effective in aiding the decision-making of clinicians and accurate planning of intervention. The data acquired with CTA and MRA can be manipulated in a multiplanar and 3D fashion and can offer exquisite detail. CTA results are generally equivalent to MRA, and both compare favourably with contrast angiography. The individual use of different imaging modalities depends on local availability, experience, and costs. Contrast angiography represents the gold standard, provides detailed information about arterial anatomy, and is recommended when revascularisation is needed.

Endovascular suitability and outcome after open surgery for ruptured abdominal aortic aneurysm

Endovascular repair of ruptured abdominal aortic aneurysm (rAAA) has rapidly gained popularity, but superior results may be biased by patient selection. The aim was to investigate whether suitability for endovascular repair predicted survival, irrespective of technique of repair.

Aortic neck dilatation after endovascular abdominal aortic aneurysm repair: a word of caution.

Continuing aortic neck dilatation, most probably an expression of ongoing aneurysmal wall degeneration of the infrarenal aortic segment, has been shown to seriously impair clinical results after endovascular abdominal aortic aneurysm repair. However, conflicting data on the extent and clinical relevance on this observation have recently been published. This article reviews the recent literature, summarizing our current understanding of the role of aortic neck dilatation after open surgical and endovascular abdominal aortic aneurysm repair. In addition, differences in methodology of studies on aortic neck dilatation are highlighted.

Endovascular treatment of common femoral artery obstructions

OBJECTIVE To evaluate the clinical efficacy of endovascular therapy of symptomatic obstructions of the common femoral artery (CFA). METHODS Consecutive series of patients undergoing endovascular therapy of chronic CFA obstructions between 1995 and 2009 and who were followed systematically within a prospectively maintained database. Clinical assessment was based on current guidelines including ankle-brachial index (ABI) and was performed at baseline and the day of discharge and then repeated at 3, 6, and 12 months and annually thereafter. Technical success of intervention was defined as a final residual diameter stenosis of <30%. Sustained clinical improvement was defined as a sustained upward shift of at least one category on the Rutherford classification compared with baseline without the need for repeated target lesion revascularization (TLR) or amputation in surviving patients. Limb salvage was defined as absence of a major (ie, above the ankle) amputation. Survival analysis was performed using the Kaplan-Meier method. RESULTS Ninety-eight patients (38 women, mean age 72 ± 11 years) presented with 104 ischemic limbs, 20 of which (19%) were classified as having critical limb ischemia (CLI). Technical success rate was 98%. Stents were placed in eight CLI patients (40%) and in 20 claudicants (24%). Mean ABI improved from 0.28 to 0.54 (P < .001) in CLI patients and from 0.61 to 0.85 (P < .001) in claudicants. Mean follow-up was 16 months. Primary sustained clinical improvement rates at 3, 6, 12, and 24 months were 55%, 55%, 40%, and 0% in CLI patients and 81%, 75%, 68%, and 52% in claudicants, respectively. Limb salvage rates at 24 months were 94% in CLI patients and 100% in claudicants. After adjustment for confounding factors, presence of ischemic ulcers (hazard ratio [HR], 4.7; 95% confidence interval [CI], 1.49-14.85; P = .009), obstruction of the femoropopliteal arterial tract (HR, 3.9; 95% CI, 1.66-9.16; P = .002) and diabetes mellitus (HR, 2.3; 95% CI, 1.02-5.28; P = .045) were independently associated with lower rates of sustained clinical improvement. CONCLUSIONS Endovascular therapy of CFA obstruction is associated with high rates of sustained clinical success in claudicants with patent femoropopliteal outflow. Presence of ischemic skin ulcers and diabetes mellitus, however, are associated with impaired efficacy of endovascular CFA treatment.

Completeness of Follow-Up Determines Validity of Study Findings: Results of a Prospective Repeated Measures Cohort Study.

Background Current reporting guidelines do not call for standardised declaration of follow-up completeness, although study validity depends on the representativeness of measured outcomes. The Follow-Up Index (FUI) describes follow-up completeness at a given study end date as ratio between the investigated and the potential follow-up period. The association between FUI and the accuracy of survival-estimates was investigated. Methods FUI and Kaplan-Meier estimates were calculated twice for 1207 consecutive patients undergoing aortic repair during an 11-year period: in a scenario A the population’s clinical routine follow-up data (available from a prospective registry) was analysed conventionally. For the control scenario B, an independent survey was completed at the predefined study end. To determine the relation between FUI and the accuracy of study findings, discrepancies between scenarios regarding FUI, follow-up duration and cumulative survival-estimates were evaluated using multivariate analyses. Results Scenario A noted 89 deaths (7.4%) during a mean considered follow-up of 30±28months. Scenario B, although analysing the same study period, detected 304 deaths (25.2%, P<0.001) as it scrutinized the complete follow-up period (49±32months). FUI (0.57±0.35 versus 1.00±0, P<0.001) and cumulative survival estimates (78.7% versus 50.7%, P<0.001) differed significantly between scenarios, suggesting that incomplete follow-up information led to underestimation of mortality. Degree of follow-up completeness (i.e. FUI-quartiles and FUI-intervals) correlated directly with accuracy of study findings: underestimation of long-term mortality increased almost linearly by 30% with every 0.1 drop in FUI (adjusted HR 1.30; 95%-CI 1.24;1.36, P<0.001). Conclusion Follow-up completeness is a pre-requisite for reliable outcome assessment and should be declared systematically. FUI represents a simple measure suited as reporting standard. Evidence lacking such information must be challenged as potentially flawed by selection bias.