Cost-efficacy issues in the treatment of peripheral vascular disease: primary amputation or revascularization for limb-threatening ischemia

Optimization of Electrospun Poly(caprolactone) Fiber Diameter for Vascular Scaffolds to Maximize Smooth Muscle Cell Infiltration and Phenotype Modulation

Due to the morphological resemblance between the electrospun nanofibers and extracellular matrix (ECM), electrospun fibers have been widely used to fabricate scaffolds for tissue regeneration. Relationships between scaffold morphologies and cells are cell type dependent. In this study, we sought to determine an optimum electrospun fiber diameter for human vascular smooth muscle cell (VSMC) regeneration in vascular scaffolds. Scaffolds were produced using poly(caprolactone) (PCL) electrospun fiber diameters of 0.5, 0.7, 1, 2, 2.5, 5, 7 or 10 μm, and VSMC survivals, proliferations, infiltrations, and phenotypes were recorded after culturing cells on these scaffolds for one, four, seven, or 10 days. VSMC phenotypes and macrophage infiltrations into scaffolds were evaluated by implanting scaffolds subcutaneously in a mouse for seven, 14, or 28 days. We found that human VSMC survival was not dependent on the electrospun fiber diameter. In summary, increasing fiber diameter reduced VSMC proliferation, increased VSMC infiltration and increased macrophage infiltration and activation. Our results indicate that electrospun PCL fiber diameters of 7 or 10 µm are optimum in terms of VSMC infiltration and macrophage infiltration and activation, albeit at the expense of VSMC proliferation.

Graft type for femoro-popliteal bypass surgery

BACKGROUND

Femoro-popliteal bypass is implemented to save limbs that might otherwise require amputation, in patients with ischaemic rest pain or tissue loss; and to improve walking distance in patients with severe life-limiting claudication. Contemporary practice involves grafts using autologous vein, polytetrafluoroethylene (PTFE) or Dacron as a bypass conduit. This is the second update of a Cochrane review first published in 1999 and last updated in 2010.

OBJECTIVES

To assess the effects of bypass graft type in the treatment of stenosis or occlusion of the femoro-popliteal arterial segment, for above- and below-knee femoro-popliteal bypass grafts.

SEARCH METHODS

For this update, the Cochrane Vascular Information Specialist searched the Vascular Specialised Register (13 March 2017) and CENTRAL (2017, Issue 2). Trial registries were also searched.

SELECTION CRITERIA

We included randomised trials comparing at least two different types of femoro-popliteal grafts for arterial reconstruction in patients with femoro-popliteal ischaemia. Randomised controlled trials comparing bypass grafting to angioplasty or to other interventions were not included.

DATA COLLECTION AND ANALYSIS

Both review authors (GKA and CPT) independently screened studies, extracted data, assessed trials for risk of bias and graded the quality of the evidence using GRADE criteria.

MAIN RESULTS

We included nineteen randomised controlled trials, with a total of 3123 patients (2547 above-knee, 576 below-knee bypass surgery). In total, nine graft types were compared (autologous vein, polytetrafluoroethylene (PTFE) with and without vein cuff, human umbilical vein (HUV), polyurethane (PUR), Dacron and heparin bonded Dacron (HBD); FUSION BIOLINE and Dacron with external support). Studies differed in which graft types they compared and follow-up ranged from six months to 10 years.Above-knee bypassFor above-knee bypass, there was moderate-quality evidence that autologous vein grafts improve primary patency compared to prosthetic grafts by 60 months (Peto odds ratio (OR) 0.47, 95% confidence interval (CI) 0.28 to 0.80; 3 studies, 269 limbs; P = 0.005). We found low-quality evidence to suggest that this benefit translated to improved secondary patency by 60 months (Peto OR 0.41, 95% CI 0.22 to 0.74; 2 studies, 176 limbs; P = 0.003).We found no clear difference between Dacron and PTFE graft types for primary patency by 60 months (Peto OR 1.67, 95% CI 0.96 to 2.90; 2 studies, 247 limbs; low-quality evidence). We found low-quality evidence that Dacron grafts improved secondary patency over PTFE by 24 months (Peto OR 1.54, 95% CI 1.04 to 2.28; 2 studies, 528 limbs; P = 0.03), an effect which continued to 60 months in the single trial reporting this timepoint (Peto OR 2.43, 95% CI 1.31 to 4.53; 167 limbs; P = 0.005).Externally supported prosthetic grafts had inferior primary patency at 24 months when compared to unsupported prosthetic grafts (Peto OR 2.08, 95% CI 1.29 to 3.35; 2 studies, 270 limbs; P = 0.003). Secondary patency was similarly affected in the single trial reporting this outcome (Peto OR 2.25, 95% CI 1.24 to 4.07; 236 limbs; P = 0.008). No data were available for 60 months follow-up.HUV showed benefits in primary patency over PTFE at 24 months (Peto OR 4.80, 95% CI 1.76 to 13.06; 82 limbs; P = 0.002). This benefit was still seen at 60 months (Peto OR 3.75, 95% CI 1.46 to 9.62; 69 limbs; P = 0.006), but this was only compared in one trial. Results were similar for secondary patency at 24 months (Peto OR 4.01, 95% CI 1.44 to 11.17; 93 limbs) and at 60 months (Peto OR 3.87, 95% CI 1.65 to 9.05; 93 limbs).We found HBD to be superior to PTFE for primary patency at 60 months for above-knee bypass, but these results were based on a single trial (Peto OR 0.38, 95% CI 0.20 to 0.72; 146 limbs; very low-quality evidence). There was no difference in primary patency between HBD and HUV for above-knee bypass in the one small study which reported this outcome.We found only one small trial studying PUR and it showed very poor primary and secondary patency rates which were inferior to Dacron at all time points.Below-knee bypassFor bypass below the knee, we found no graft type to be superior to any other in terms of primary patency, though one trial showed improved secondary patency of HUV over PTFE at all time points to 24 months (Peto OR 3.40, 95% CI 1.45 to 7.97; 88 limbs; P = 0.005).One study compared PTFE alone to PTFE with vein cuff; very low-quality evidence indicates no effect to either primary or secondary patency at 24 months (Peto OR 1.08, 95% CI 0.58 to 2.01; 182 limbs; 2 studies; P = 0.80 and Peto OR 1.22, 95% CI 0.67 to 2.23; 181 limbs; 2 studies; P = 0.51 respectively)Limited data were available for limb survival, and those studies reporting on this outcome showed no clear difference between graft types for this outcome. Antiplatelet and anticoagulant protocols varied extensively between trials, and in some cases within trials.The overall quality of the evidence ranged from very low to moderate. Issues which affected the quality of the evidence included differences in the design of the trials, and differences in the types of grafts they compared. These differences meant we were often only able to combine and analyse small numbers of participants and this resulted in uncertainty over the true effects of the graft type used.

AUTHORS' CONCLUSIONS

There was moderate-quality evidence of improved long-term (60 months) primary patency for autologous vein grafts when compared to prosthetic materials for above-knee bypasses. In the long term (two to five years) there was low-quality evidence that Dacron confers a small secondary patency benefit over PTFE for above-knee bypass. Only very low-quality data exist on below-knee bypasses, so we are uncertain which graft type is best. Further randomised data are needed to ascertain whether this information translates into an improvement in limb survival.

A Tubular Biomaterial Construct Exhibiting a Negative Poisson's Ratio

Developing functional small-diameter vascular grafts is an important objective in tissue engineering research. In this study, we address the problem of compliance mismatch by designing and developing a 3D tubular construct that has a negative Poisson's ratio νxy (NPR). NPR constructs have the unique ability to expand transversely when pulled axially, thereby resulting in a highly-compliant tubular construct. In this work, we used projection stereolithography to 3D-print a planar NPR sheet composed of photosensitive poly(ethylene) glycol diacrylate biomaterial. We used a step-lithography exposure and a stitch process to scale up the projection printing process, and used the cut-missing rib unit design to develop a centimeter-scale NPR sheet, which was rolled up to form a tubular construct. The constructs had Poisson's ratios of -0.6 ≤ νxy ≤ -0.1. The NPR construct also supports higher cellular adhesion than does the construct that has positive νxy. Our NPR design offers a significant advance in the development of highly-compliant vascular grafts.

Preventable Complications Driving Rising Costs in Management of Patients with Critical Limb Ischemia

BACKGROUND

This study aimed to identify factors that drive increasing health-care costs associated with the management of critical limb ischemia in elective inpatients.

METHODS

Patients with a primary diagnosis code of critical limb ischemia (CLI) were identified from the 2001-2011 Nationwide Inpatient Sample. Demographics, CLI management, comorbidities, complications (bleeding, surgical site infection [SSI]), length of stay, and median in-hospital costs were reviewed. Statistical analysis was completed using Students' t-test and Mann-Kendall trend analysis. Costs are reported in 2011 US dollars corrected using the consumer price index.

RESULTS

From 2001 to 2011, there were a total of 451,823 patients who underwent open elective revascularization as inpatients for CLI. Costs to treat CLI increased by 63% ($12,560 in 2001 to $20,517 in 2011, P < 0.001 in trend analysis). Endovascular interventions were 20% more expensive compared with open surgery ($19,566 vs. $16,337, P < 0.001). Age, gender, and insurance status did not affect the cost of care. From 2001 to 2011, the number of patient comorbidities (7.56-12.40) and percentage of endovascular cases (13.4% to 27.4%) increased, accounting for a 6% annual increase in total cost despite decreased median length of stay (6 to 5 days). Patients who developed SSI had total costs 83% greater than patients without SSIs ($30,949 vs. $16,939; P < 0.001). Patients who developed bleeding complications had total costs 41% greater than nonbleeding patients ($23,779 vs. $16,821, P < 0.001). Overall, there was a 32% reduction in SSI rates but unchanged rates of bleeding complications during this period.

CONCLUSIONS

The cost of CLI treatment is increasing and driven by rising endovascular use, SSI, and bleeding in the in-patient population. Further efforts to reduce complications in this patient population may contribute to a reduction in health care-associated costs of treating CLI.

Graft type for femoro-popliteal bypass surgery

BACKGROUND

Femoro-popliteal bypass is implemented to save limbs that might otherwise require amputation, in patients with ischaemic rest pain or tissue loss; and to improve walking distance in patients with severe life-limiting claudication. Contemporary practice involves using autologous vein, polyterafluoroethylene (PTFE) or Dacron as a bypass conduit.This is an update of a Cochrane review first published in 1999 and previously updated in 2002.

OBJECTIVES

The objective of this review was to determine the most effective type of graft for femoro-popliteal bypass surgery.

SEARCH STRATEGY

The Cochrane Peripheral Vascular Diseases Group searched their Specialised Register (last searched January 2010) and the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2010, Issue 1 for last search). The authors searched reference lists of relevant articles, and handsearched conference proceedings from the British and European Vascular Surgical Societies.

SELECTION CRITERIA

Randomised trials comparing femoro-popliteal grafts.

DATA COLLECTION AND ANALYSIS

Two authors (CT and ADM) screened studies, extracted data and assessed trials.

MAIN RESULTS

Thirteen randomised control trials were included with a total of 2313 patients (1955 above knee, 358 below knee bypass surgery). Seven graft types were compared (reversed and in situ autologous vein, PTFE with and without vein cuff, human umbilical vein (HUV), Dacron and heparin bonded Dacron (HBD).Above the knee, there was a benefit in primary patency for autologous vein over PTFE (P = 0.0001) and HUV (P = 0.0003) by 60 months. Dacron showed primary patency benefit over PTFE by 24 months (P = 0.02), continuing to 60 months (P = 0.02). HUV also showed benefit over PTFE by 24 months (P = 0.0003) in one trial. Below the knee, in the one trial there was a significant benefit in primary patency for PTFE with a vein cuff when compared to PTFE alone at all time intervals to 24 months (P = 0.03).Limited data were available for limb survival. Antiplatelet and anticoagulant protocols varied extensively between trials, and in some cases within trials.

AUTHORS' CONCLUSIONS

There was a clear primary patency benefit for autologous vein when compared to synthetic materials for above knee bypasses. In the long term (five years) Dacron confers a small primary patency benefit over PTFE for above knee bypass. PTFE with a vein cuff improved primary patency when compared to PTFE alone for below knee bypasses. Further randomised data is needed to ascertain whether this information translates into improvement in limb survival.

“Successful Outcome” after Below-Knee Amputation: An Objective Definition and Influence of Clinical Variables

Functional success after below-knee amputation (BKA) has been poorly studied. The purpose of this study was to establish a consistent definition of “successful outcome” after BKA and to identify clinical variables influencing that definition. Three hundred nine consecutive patients undergoing BKA were evaluated postoperatively using the following definition for “successful outcome”: 1) wound healing of the BKA without need for revision to a higher level; 2) maintenance of ambulation with a prosthesis for at least 1 year or until death; and 3) survival for at least 6 months. Independent clinical predictors influencing outcome were determined using bivariate and multivariable logistic regression analyses. For the cohort, median survival and maintenance of ambulation were 44 months and 60 months, respectively. Although 86.4 per cent of patients healed without the need for revision to a higher level, 63.4 per cent maintained ambulation with a prosthesis for 1 year and 86.1 per cent survived for 6 months, successful outcome as defined by attaining all three components of the definitions occurred in only 51.1 per cent (n = 158) of patients. Of 19 clinical variables examined, six were identified in bivariate analysis as significantly associated with outcome. However, only three were found to be independent predictors of outcome using logistic regression modeling. The presence of coronary artery disease [odds ratio (OR), 0.465; 95% CI, 0.289–0.747], cerebrovascular disease (OR, 0.389; 95% CI, 0.154–0.980), and impaired ambulatory ability before BKA (OR, 0.310; 95% CI, 0.154–0.623) were each associated with a decreased odds for successful outcome. Patients who presented with impaired ambulatory ability in combination with another independent predictor had only a 20 per cent to 23 per cent probability of successful outcome and patients who presented with all three had a 10.4 per cent probability of success. In contrast, patients who had none of the independent predictors at presentation had a 67.5 per cent probability of successful outcome after BKA. A standardized definition of success after BKA capable of predicting outcomes is feasible and can be a useful tool to determine rehabilitation potential. When judged by our definition, patients without predictors of failure possess a high potential for rehabilitation, whereas patients with multiple predictors rarely rehabilitate, should probably receive palliative above-knee amputation, and forgo the expense of futile prosthetic training.

Spinal cord stimulation is not cost-effective for non-surgical management of critical limb ischaemia

OBJECTIVE

To quantify the costs of treatment in critical limb ischaemia (CLI) and to compare costs and effectiveness of two treatment strategies: spinal cord stimulation (SCS) and best medical treatment.

METHODS

One hundred and twenty patients with CLI not suitable for vascular reconstruction were randomised to either SCS in addition to best medical treatment or best medical treatment alone. Primary outcomes were mortality, amputation and cost. Cost analysis was based on resources used by patients for 2 years after randomisation. Both medical and non-medical costs were included.

RESULTS

Patient and limb survival were similar in the two treatment groups. Costs of in-hospital-stay and institutional rehabilitation constituted the predominant part (+/-70%) of the total costs of medical care in CLI. Cost of SCS-implantation and complications (7950 euro per patient) exceeded by far cost due to amputation procedures (410 euro per patient). The total costs of treatment were 36,600 euro per patient over 2 years for the SCS-group vs. 28,700 euro for best medical treatment alone (28% higher for SCS-group, p=0.009).

CONCLUSIONS

Total costs of treatment in CLI are high. Major components are hospital and rehabilitation costs. In contrast to recent reviews, there were no long-term benefits of SCS-treatment. Therefore, cost-effectiveness is reduced to cost-minimisation and SCS-treatment is considerably more expensive than best medical treatment.

Prediction of vascular tissue engineering results with artificial neural networks

Tissue engineers are often confused on finding the most successful strategy for specific patient. In this study, we used artificial neural networks to predict the outcomes of different vascular tissue engineering strategies, thus providing advisory information for experimental designers. Over 30 variables were used as features of the tissue engineering strategies. Different architectures of artificial neural networks with back propagation algorithm were tested to obtain the best model configuration for the prediction of the tissue engineering strategies. In the computational experiments, the artificial neural networks with one and two hidden layers could, respectively, detect unsuccessful strategies with the highest predictive accuracy of 91.45 and 94.24%. In conclusion, artificial intelligence has great potential in tissue engineering decision support. It can provide accurate advisory information for tissue engineers, thus reducing failures and improving therapeutic effects.

Contemporary results of angioplasty-based infrainguinal percutaneous interventions

INTRODUCTION

Although lower-extremity bypass grafting has been the gold standard for infrainguinal revascularization, endovascular therapies have been increasingly applied to avoid operative morbidities. This study addresses the initial results of an implementation of infrainguinal percutaneous transluminal angioplasty (PTA) performed by vascular surgeons to treat lower-extremity ischemia.

METHODS

From January 2002 to July 2003, 95 consecutive patients presenting with the spectrum of lower-extremity ischemic manifestations, in whom infrainguinal PTA was the initial choice of treatment, were assessed for treatment efficacy by clinical and noninvasive evaluation. Study end points of angiographic, hemodynamic, and clinical successes (Society of Vascular Surgery reporting standards) were recorded, and variables associated with ischemic category improvement were analyzed by univariate and multivariate analysis. During the same study interval, 87 patients underwent bypass grafting (not further considered).

RESULTS

PTA was used to treat 100 limbs in 95 consecutive patients: 63 limbs (63%) had femoropopliteal PTA, 17 limbs (17%) had tibioperoneal PTA, and 20 limbs (20%) had multilevel PTA. Tissue-threatening ischemia was present in 47% of patients, and 53% were treated for claudication. Complications (no mortality) included one myocardial infarction (1%) and two access site hematomas (2%). Angiographic and hemodynamic success (a .10 increase in ankle-brachial index) was obtained in 97% and 90% of the treated limbs, respectively. With a mean follow-up of 14 months, clinical success was obtained in 85% of the treated limbs, and limb salvage for critical ischemia was achieved in 75% (30/40 limbs). Of the PTA failures, five patients (5%) underwent bypass grafting, and five patients (5%) underwent major amputation because of no further reconstructive options or extensive necrosis. Insulin-dependent diabetes mellitus (risk ratio [RR], 3.1; 95% confidence interval [CI], 1.1 to 8.7, P = .02), poor runoff into the foot (RR, 3.7; 95% CI, 1.6 to 8.6, P = .001), and renal insufficiency (serum creatinine >1.5 mg/dL) (RR, 3.7; 95% CI, 1.8 to 7.6, P = .001) were predictive of PTA failure.

CONCLUSION

Infrainguinal percutaneous transluminal angioplasty for lower-extremity ischemia is feasible, safe and provides acceptable hemodynamic and clinical results. PTA will become the initial treatment for most patients requiring lower-extremity revascularization.

Tissue-Engineered Vessel Strengthens Quickly under Physiological Deformation: Application of a New Perfusion Bioreactor with Machine Vision

In order to develop a patent tissue-engineered blood vessel that grossly resembles native tissue, required culture times in most studies exceed 8 weeks. For the sake of shortening the maturation period of the constructs, we have used deformation as the basic index for mechanical environment control. A new bioreactor with a machine vision identifier was developed to accurately control the deformation of the construct during the perfusion process. Two groups of seeded constructs (n = 4 per group) were investigated in this study, with one group stimulated by a cyclic deformation of 10% and the other by a pulsatile pressure that gradually increased to 120 mm Hg (the control group). After 21 days of culture, the mechanical properties of the constructs were examined. The average burst strength and suture retention strength in the two groups were significantly different (t test, p < 0.05). For the experimental group, the average burst strength and suture retention strength were higher than those of the control group, by 31.6 and 23.4%, respectively. Specifically, the average burst strength of the constructs reached 1,402 mm Hg (close to that of the native vessel, i.e. 1,680 mm Hg) within a relatively short period of 21 days. In conclusion, deformation is an observable, controllable and very valuable index for mechanical environment control in vascular tissue engineering. It makes the control of mechanical stimuli more essential and experiments more comparable.

Preoperative clinical factors predict postoperative functional outcomes after major lower limb amputation: an analysis of 553 consecutive patients

BACKGROUND

Despite being a major determinant of functional independence, ambulation after major limb amputation has not been well studied. The purpose, therefore, of this study was to investigate the relationship between a variety of preoperative clinical characteristics and postoperative functional outcomes in order to formulate treatment recommendations for patients requiring major lower limb amputation.

METHODS

From January 1998 through December 2003, 627 major limb amputations (37.6% below knee amputations, 4.3% through knee amputations, 34.5% above knee amputations, and 23.6% bilateral amputations) were performed on 553 patients. Their mean age was 63.7 years; 55% were men, 70.2% had diabetes mellitus, and 91.5% had peripheral vascular disease. A retrospective review was performed correlating various preoperative presenting factors such as age at presentation, race, medical comorbidities, preoperative ambulatory status, and preoperative independent living status, with postoperative functional endpoints of prosthetic usage, survival, maintenance of ambulation, and maintenance of independent living status. Kaplan-Meier survival curves were constructed and compared by using the log-rank test. Odds ratios (OR) and hazard ratios (HR) with 95% confidence intervals were constructed by using multiple logistic regressions and Cox proportional hazards models.

RESULTS

Statistically significant preoperative factors independently associated with not wearing a prosthesis in order of greatest to least risk were nonambulatory before amputation (OR, 9.5), above knee amputation (OR, 4.4), age > 60 years (OR, 2.7), homebound but ambulatory status (OR, 3.0), presence of dementia (OR, 2.4), end-stage renal disease (OR, 2.3), and coronary artery disease (OR, 2.0). Statistically significant preoperative factors independently associated with death in decreasing order of influence included age > or = 70 years (HR, 3.1), age 60 to 69 (HR, 2.5), and the presence of coronary artery disease (HR, 1.5). Statistically significant preoperative factors independently associated with failure of ambulation in decreasing order of influence included age > or = 70 years (HR, 2.3), age 60 to 69 (HR, 1.6), bilateral amputation (HR, 1.8), and end-stage renal disease (HR, 1.4). Statistically significant preoperative factors independently associated with failure to maintain independent living status in decreasing order of influence included age > or = 70 years (HR, 4.0), age 60 to 69 (HR, 2.7), level of amputation (HR, 1.8), homebound ambulatory status (HR, 1.6), and the presence of dementia (HR, 1.6).

CONCLUSIONS

Patients with limited preoperative ambulatory ability, age > or = 70, dementia, end-stage renal disease, and advanced coronary artery disease perform poorly and should probably be grouped with bedridden patients, who traditionally have been best served with a palliative above knee amputation. Conversely, younger healthy patients with below knee amputations achieved functional outcomes similar to what might be expected after successful lower extremity revascularization. Amputation in these instances should probably not be considered a failure of therapy but another treatment option capable of extending functionality and independent living.

A novel hyaluronan-based biomaterial (Hyaff-11®) as a scaffold for endothelial cells in tissue engineered vascular grafts

Current prosthetic small diameter vascular grafts show poor long-term patency rates, leading to the pursuit of a biological alternative. Hyaff-11 is a hyaluronan-based biodegradable polymer developed for tissue-engineering applications. This study aimed to determine whether human vascular endothelial cells attach to Hyaff-11 scaffolds and produce a subendothelial matrix. Two forms of fibrous, non-woven Hyaff-11 scaffolds: unpressed and pressed felts, were analysed. Attachment of human venous endothelial cells was investigated after 1, 5, 10 and 20 days in culture using SEM and confocal microscopy. The deposition of subendothelial matrix components was investigated by immunofluorescent staining. We demonstrate that endothelial cells adhere to the individual fibres of both unpressed and pressed scaffolds: with a seeding density of 1 x 10(6) cells/cm(2), 94% of the cells attached to Hyaff-11 fibres after 24 h. The pressed material provided the best environment for cell growth, allowing the formation of a complete endothelial monolayer after 20 days. Furthermore, endothelial cells on Hyaff-11 pressed felts deposited an organised subendothelial matrix containing laminin, fibronectin, type IV and type VIII collagen. This work indicates Hyaff-11 based biopolymers as suitable scaffolds to promote endothelialisation within the next generation of vascular grafts.

Tissue engineering of small diameter vascular grafts

Tissue engineering, using either polymer or biological based scaffolds, represents the newest approach to overcoming limitations of small diameter prosthetic vascular grafts. Their disadvantages include thromboembolism and thrombosis, anticoagulant related haemorrhage, compliance mismatch, neointimal hyperplasia, as well as aneurysm formation. This current review represents an overview about previous and contemporary studies in the field of artificial vascular conduits development regarding arterial and venous autografts, allografts, xenografts, alloplastic prostheses, and tissue engineering.

The increasing role of percutaneous transluminal angioplasty in the primary management of critical limb ischaemia

OBJECTIVE

to review the current role and results of angioplasty in the management of critical limb ischaemia (CLI) in a single institution.

METHODS

data on 526 patients with 608 ischaemic limbs, treated between January 1994 and December 1999 was collected prospectively and analysed retrospectively. Patients were divided into 3 groups according to the date of presentation: group 1 (1994-95), group 2 (1996-97) and group 3 (1998-99). The groups were comparable in terms of demographics, mode of presentation and level of disease.

RESULTS

Revascularisation was attempted in 87%, 81% and 91% for groups 1, 2 and 3 respectively (NS). Primary percutaneous transluminal angioplasty (PTA) rates increased from 44% (1994-95) to 69% (1998-99) (p < 0.001), and surgical revascularisation rates decreased correspondingly (p<0.01). Overall cumulative patient survival and limb salvage rates were 82% and 89% for 1 year and 45% and 87% for 5 years, respectively. No statistically significant difference existed between the three groups regarding patient survival, limb salvage rates and mean hospital stay (19, 12 and 12 days, respectively).

CONCLUSION

PTA is increasingly replacing bypass surgery in the treatment of CLI, without compromising patient survival or limb salvage rates.

Criteria for prosthetic provision: "he who pays the piper calls the tune"

Previously instituted policies regarding prosthetic limb provision had been deemed dependable. A follow-up home visit study showed that 18 of 60 patients that had been provided with prostheses, did not make use of them. Analysis showed that three categories of patients made up the large majority of the non-users; double amputees, blind persons and those with psychiatric disorders. In order to attempt to eliminate the wastage of prosthetic provision to non-ambulators a new policy decision was made. Doubtful ambulators and those from the three aforementioned categories will be initially provided with temporary prostheses. Only after a period of months of temporary prosthetic usage at home will a decision be made as to whether a permanent prosthesis will be issued.

Influence of age and hospital volume on the results of carotid endarterectomy: a statewide analysis of 9918 cases

PURPOSE

This study evaluated the impact of patient age and hospital volume on the results of carotid endarterectomy (CEA) in contemporary practice.

METHODS

The Maryland Health Services Cost Review Commission (MHSCRC) database was reviewed to identify all patients who underwent elective CEA as the primary procedure in all acute care hospitals in the state over the past 6 years.

RESULTS

From January 1990 through December 1995, 9918 elective CEAs were performed in 48 hospitals at a total charge of $68.9 million. Postoperative death and neurologic complications occurred in 90 (0.9%) and 166 (1.7%) cases, including 0.8% and 1.7%, 0.9% and 1.6%, 0.9% and 1.8%, and 1.4% and 1.3% of patients < 65 years, 65 to 69 years, 70 to 79 years, and > or = 80 years old, respectively. The mean length of stay and hospital charges increased linearly with increasing age: 4.2 days/$6550, 4.4 days/$6834, 4.8 days/$7059, and 5.6 days (p < 0.0001 vs others)/$7756 (p < 0.005 vs 70 to 79 years and p < 0.0003 vs < 70 years old), respectively, for patients < 65, 65 to 69, 70 to 79, and > or = 80 years old. The mortality rate was 1.9% in low-volume hospitals, 1.1% in moderate-volume hospitals, and 0.8% in high-volume hospitals. The neurologic complication rate was significantly higher (6.1%; p < 0.0001) in low-volume when compared with moderate-volume (1.3%) and high-volume (1.8%) hospitals.

CONCLUSIONS

CEA is a safe procedure in the majority of hospitals in contemporary practice, even among the very elderly, who may experience a longer length of stay and higher charges correlating with their documented greater medical complexity.