Angiographic scoring of vascular occlusive disease in the diabetic foot: relevance to bypass graft patency and limb salvage

Influence of a Novel Morphology-Driven Classification on Limb Salvage after Isolated Tibial Intervention for Chronic Limb Threatening Ischemia

BACKGROUND

Infra-popliteal interventions for chronic limb-threatening ischemia (CLTI) can be impacted by the morphology of the tibial vessels. The aim of this study was to examine the impact of a novel morphology-driven classification on the outcomes of isolated tibial intervention for CLTI.

METHODS

A database of patients undergoing isolated tibial interventions for CLTI at a single center between 2010 and 2020 was retrospectively queried. Patients with isolated Infra-popliteal disease were identified, and their anatomy was scored as present or absent for lesion calcification (1 point), target vessel diameter<3.0 mm (1 point), lesion length>300mm (1 point) and poor pedal runoff score (1 point). Patients were then divided into three groups: low-risk (0 or 1 points), moderate-risk (2 points), and high-risk (3 or 4 points). Intention to treat analysis by the patient was performed. Limb-based patency (the absence of reintervention, occlusion, critical stenosis (>70%), or hemodynamic compromise with ongoing symptoms of CLTI as it related to the patency of the preoperatively determined target artery pathway) was assessed. Patient-orientated outcomes of amputation-free survival (AFS; survival without major amputation) and freedom from major adverse limb events (MALE; Above ankle amputation of the index limb or major re-intervention (new bypass graft, jump/interposition graft revision) were evaluated.

RESULTS

1607 patients (55% male, average age 60 years, 3846 vessels) underwent tibial intervention for CLTI. The majority of the patients were diabetic and of Hispanic. origin Morphologically, 27%, 31%, and 42% of the vessels were categorized as low risk, moderate risk, and high risk, respectively. There was a significant worsening of the infra-popliteal Global Limb Anatomic Staging System (GLASS) grading as the morphological risk increased. The 30-day major adverse cardiac events (MACE) were equivalent across the groups and were under the stated objective performance goal (OPG) of ≤10%. In contrast, both the 30-day MALE and the 30-day Major Amputations were significantly different across the groups, with the low-risk group remaining under the OPG of ≤9% and ≤4%, respectively, while the moderate-risk and high-risk exceeded the goal threshold. For the OPG. Freedom from MALE was 60±5%, 46±5%, and 22±9% at 5 years for low-, moderate-, and high-risk groups, respectively (mean ± SEM; p =0.008. Overall amputation-free survival (AFS) was 55±5%, 37±6%, and 18±7% at 5 years for low-, moderate-, and high-risk groups, respectively (mean ± SEM; p=0.003).

CONCLUSIONS

Tibial anatomic morphology impacts isolated tibial endovascular intervention with adverse morphology associated with poorer short and long-term outcomes. Risk stratification based on anatomic predictors should be an additional consideration as one intervenes on infra-popliteal vessels for CLTI.

Pedal medial arterial calcification influences the outcomes of isolated infra-malleolar interventions for chronic limb-threatening ischemia

OBJECTIVE

Inframalleolar disease is present in most diabetic patients presenting with tissue loss. Inframalleolar (pedal) artery disease and pedal medial arterial calcification (pMAC) are associated with major amputation in patients with chronic limb-threatening ischemia (CLTI). This study aimed to examine the impact of pMAC on the outcomes after isolated inframalleolar (pedal artery) interventions.

METHODS

A database of lower extremity endovascular intervention for patients with tissue loss between 2007 and 2022 was retrospectively queried. Patients with CLTI were selected, and those undergoing isolated inframalleolar intervention on the dorsalis pedis and medial and lateral tarsal arteries and who had foot x-rays were identified. X-rays were assessed blindly for pMAC and scored on a scale of 0 to 5. Patients with concomitant superficial femoral artery and tibial interventions were excluded. Intention to treat analysis by the patient was performed. Amputation-free survival (survival without major amputation) was evaluated.

RESULTS

A total of 223 patients (51% female; 87% Hispanic; average age, 66 years; 323 vessels) underwent isolated infra-malleolar intervention for tissue loss. All patients had diabetes, 96% had hypertension, 79% had hyperlipidemia, and 63% had chronic renal insufficiency (55% of these were on hemodialysis). Most of the patients had Wound, Ischemia, and foot Infection (WIfI) stage 3 disease and had various stages of pMAC: severe (score = 5) in 48%, moderate (score = 2-4) in 31%, and mild (score = 0-1) in 21% of the patients. Technical success was 94%, with a median of one vessel treated per patient. All failures were in severe pMAC. Overall, major adverse cardiovascular events was 0.9% at 90 days after the procedure. Following the intervention, most patients underwent a planned forefoot amputation (single digit, multiple digits, ray amputation, or trans-metatarsal amputation). WIfI ischemic grade was improved by 51%. Wound healing at 3 months was 69%. Those not healing underwent below-knee amputations. The overall 5-year amputation-free survival rate was 35% ± 9%. The severity of pMAC was associated with decreased AFS.

CONCLUSIONS

Increasing severity of pMAC influences the technical and long-term outcomes of infra-malleolar intervention in diabetes. Severe pMAC is associated with amputation and should be considered as a variable in the shared decision-making of diabetic patients with CLTI.

Grades of Below-the-Ankle Arterial Occlusive Disease following the Angiosome Perfusion: A New Morphological Assessment and Correlations with the Inframalleolar GVG Stratification in CLTI Patients

PURPOSE

To assess a specific classification of the foot atherosclerotic disease concerning the angiosomal source arteries, the connected foot arches and attached collaterals for Rutherford 5, CLTI patients. To compare eventual analogies of this novel grading system with previously reported GLASS/GVG inframalleolar patterns of occlusive disease (P0-P2).

MATERIALS AND METHODS

A series of 336 ischemic feet (221 diabetics) were selected and retrospectively analyzed. For each angiographic pattern of inframalleolar atherosclerotic disease, 4 severity classes of targeted angiosomal artery path (TAAP), associating 4 other classes concerning linked foot arches (LFA) and collaterals occlusive disease were described. By associating the 4 TAAP with the 4 others parallel LFA and collaterals classes, 4 novel anatomical "Grades" (A-D) of occlusive disease were described. Limb salvage was studied between groups of diabetic and non-diabetic patients.

RESULTS

Using a primary endovascular approach, limb preservation comparison of grade A/B proved without significance for diabetics (P = 0.032) and non-diabetics (P = 0.226). Comparison in diabetics and/or non-diabetics between A/C (P = 0.045 and 0.046), A/D (P = 0.027 and 0.030, B/C (P = 0.009 and 0.038), and B/D (P = 0.006 and P = 0.042), as well as C/D groups (P = 0.048 and P = 0.034) proved ponderous. Parallel analysis of similar grades (A/A, B/B, etc.) with, or without diabetes appeared without significance (P > 0.05). Further comparison between grades A+B (assigned as P0/GVG), versus C (P1), and D (P2), proved significant (P < 0.0001).

CONCLUSION

The present grading system proposes a useful correlation between the severity of foot angiosomal arteries, arches, and collaterals disease and limb salvage, confirming the clinical significance of P0-P2 GVG severity score. This analysis also points the limits of EVT to be probably avoided in grade D patients.

Effect of Direct Endovascular Revascularization Based on the Angiosome Model on Risk of Major Amputations and Life Expectancy in Type 2 Diabetic Patients with Critical Limb Ischemia and Foot Ulceration

BACKGROUND

We evaluated whether direct or indirect endovascular revascularization based on the angiosome model affects outcomes in type 2 diabetes and critical limb ischemia.

METHODS

From 2010 to 2015, 603 patients with type 2 diabetes were admitted for critical limb ischemia and submitted to endovascular revascularization. Among these patients, 314 (52%) underwent direct and 123 (20%) indirect revascularization, depending on whether the flow to the artery directly feeding the site of ulceration, according to the angiosome model, was successfully acquired; 166 patients (28%) were judged unable to be revascularized. Outcomes were healing, major amputation, and mortality rates.

RESULTS

An overall healing rate of 62.5% was observed: patients who did not receive percutaneous transluminal angioplasty presented a healing rate of 58.4% (P < .02 versus revascularized patients). A higher healing rate was observed in the direct versus the indirect group (82.4% versus 50.4%; P < .001). The major amputation rate was significantly higher in the indirect versus the direct group (9.2% versus 3.2%; P < .05). The overall mortality rate was 21.6%, and it was higher in the indirect versus the direct group (24% versus 14%; P < .05).

CONCLUSIONS

These data show that direct revascularization of arteries supplying the diabetic foot ulcer site by means of the angiosome model is associated with a higher healing rate and lower risk of amputation and death compared with the indirect procedure. These results support use of the angiosome model in type 2 diabetes with critical limb ischemia.

Society for Vascular Surgery femoral runoff score is associated with limb-based patency after aortofemoral bypass

OBJECTIVE

Despite advancements, aortofemoral bypass (AFB) remains the most durable option for aortoiliac occlusive disease. Although runoff has been shown to be associated with AFB patency, the association of the Society for Vascular Surgery (SVS) thigh runoff scoring system with patency has not been assessed. The aim of the present study was to evaluate the association between the SVS runoff scoring system and limb-based primary patency after AFB.

METHODS

Institutional data for patients undergoing AFB with preoperative runoff imaging available from 2000 to 2017 were queried. Runoff scores were assigned according to the presence of occlusive disease in the superficial femoral artery and profunda femoris artery (minimum, 1; maximum, 10) as described by the 1997 SVS reporting standards for lower extremity ischemia. Limb-based patency was the primary endpoint. Kaplan-Meier analysis was used to compare the long-term limb-based patency and freedom from reintervention between limbs with runoff scores ≥6 and those with runoff scores <6. Propensity score-weighted Cox proportional hazards modeling was used to evaluate the association between a runoff score of ≥6 and primary patency loss, controlling for other factors associated with primary patency.

RESULTS

In 161 patients, 316 limbs had undergone revascularization. The mean patient age was 66.7 ± 11.3 years, and 51.6% were women. Most limbs had undergone revascularization for claudication (56.5%). Most (89.4%) had TransAtlantic InterSociety Consensus class D lesions, 27.3% had required suprarenal or higher clamping, and 11.2% had undergone concomitant mesenteric intervention. A femoral outflow adjunct and concurrent lower extremity bypass was required in 41.8% and 2.9% of limbs, respectively. Those with a runoff score of ≥6 had experienced greater rates of 30-day myocardial infarction (11% vs 1%; P = .005), respiratory failure (11% vs 1%; P = .005), and mortality (8% vs 0%; P ≤ .006). The median follow-up period was 4.0 years (interquartile range, 6.5 years). The 1-, 3-, and 5-year primary patency was 94.6% (95% confidence interval [CI], 91.9%-97.3%), 89.2% (95% CI, 85.4%-93.2%), and 81.4% (95% CI, 76.0%-87.1%), respectively. The 5-year primary-assisted patency, secondary patency, and freedom from reintervention were 84.9% (95% CI, 79.7%-90.5%), 91.7% (95% CI, 87.3%-96.3%), and 83.3% (95% CI, 78.3%-88.7%), respectively. Patients with a runoff score of ≥6 had lower primary (log-rank P < .01), primary-assisted (P < .01), and secondary patency (P = .01). The factors associated with the loss of primary patency included a high runoff score (runoff score of ≥6: hazard ratio [HR], 4.1; 95% CI, 2.1-8.0; P < .01), simultaneous mesenteric endarterectomy (HR, 13.5; 95% CI, 1.9-97.8; P = .01), and chronic kidney disease (HR, 4.6; 95% CI, 1.5-14.6; P = .01). Increasing age (HR, 0.94 per year; 95% CI, 0.91-0.97; P < .01) and hyperlipidemia (HR, 0.44; 95% CI, 0.23-0.85; P = .01) were protective.

CONCLUSIONS

The SVS femoral runoff score is an important factor associated with long-term AFB limb patency. Scores of ≥6 portend for worse limb outcomes and a greater incidence of operative complications. The SVS score can be determined from preoperative axial imaging studies and serve as a guide in decision-making and operative planning.

A Review and Proposed Classification System for the No-Option Patient With Chronic Limb-Threatening Ischemia

A growing, but poorly defined subset of patients with chronic limb-threatening ischemia (CLTI) have "no option" for revascularization. One notable subgroup includes patients with severe ischemia and advanced pedal artery occlusive disease, termed "desert foot," who are at high risk for major amputation due to a lack of conventional revascularization options. Although new therapies are being developed for no-option patients with desert foot anatomy, this subgroup and the broader group of no-option patients are not well defined, limiting the ability to evaluate outcomes. Based on a systematic review, a classification of the no-option CLTI patient was constructed for use in clinical practice and studies. Several no-option conditions were identified, including type I-severe and pedal occlusive disease (desert foot anatomy) for which there is no accepted method of repair; type II-lack of suitable venous conduit for bypass in the setting of an acceptable target for bypass; type III-extensive tissue loss with exposure of vital structures that renders salvage impossible; type IV-advanced medical comorbidities for which available revascularization options would pose a prohibitive risk; and type V-presence of a nonfunctional limb. While type I and type II patients may have no option for revascularization, type III and type V patients have wounds, infection, comorbidities, or functional status that may leave them with few options for revascularization. As treatment strategies continue to evolve and novel methods of revascularization are developed, the ability to identify no-option patients in a standardized fashion will aid in treatment selection and assessment of outcomes.

Prevalence and factors associated with lower limb amputation in individuals with type II diabetes mellitus in a referral hospital in Fortaleza, Ceará, Brazil: A hospital-based cross-sectional study

AIMS

To analyze the association between demographic, socioeconomic, clinical, epidemiological, and primary healthcare factors with the severity of lower limb amputations (LLAs) in individuals with type II diabetes mellitus (DM-II) at a reference hospital in Fortaleza, Ceará, in Northeast Brazil.

METHODS

A cross-sectional study was performed with a representative sample of individuals hospitalized with DM-II and the degree of LLA severity: (1) toes; (2) transmetatarsal or infrapatellar; (3) suprapatellar; (4) disarticulation or bilateral. Potentially associated factors with the outcome degree of amputation severity were identified in a semi-structured evaluation during hospitalization. The prevalence ratios of the degree of amputation severity as a function of associated factors were calculated with robust variance Poisson regression models.

RESULTS

The prevalence of high degree of severity in amputations (suprapatellar, with disarticulation or bilateral) was high in the total sample of 385 patients, revealing to be 49% (187/385). Prevalence ratios (PR) indicated a higher prevalence of DM-II amputation severity in patients who lacked of specific guidance on DM-II amputation in primary care (PR = 1.52, 95% CI: 1.05-2.21).

CONCLUSIONS

LLAs in DM-II were associated with age above 67 years, male gender, cardiovascular disease, and low support for guidance at the primary healthcare level.

Outcomes of isolated inframalleolar interventions for chronic limb-threatening ischemia in diabetic patients

BACKGROUND

Inframalleolar disease is present in many diabetic patients presenting with tissue loss. The aim of this study was to examine the patient-centered outcomes after isolated inframalleolar interventions.

METHODS

A database of patients undergoing lower extremity endovascular interventions for tissue loss (critical limb-threatening ischemia, Wound, Ischemia, and foot Infection [WIfI] stage 1-3) and a de novo intervention on the index limb between 2007 and 2017 was retrospectively queried. Those patients with isolated inframalleolar interventions on the dorsalis pedis and medial and lateral tarsal arteries were identified. Patients with concomitant superficial femoral artery and tibial interventions were excluded. Intention-to-treat analysis by patient was performed. Patient-oriented outcomes of clinical efficacy (absence of recurrent symptoms, maintenance of ambulation, and absence of major amputation), amputation-free survival (AFS; survival without major amputation), and freedom from major adverse limb events (above-ankle amputation of the index limb or major reintervention [new bypass graft, jump or interposition graft revision]) were evaluated.

RESULTS

There were 109 patients (48% male; average age, 65 years; 153 vessels) who underwent isolated inframalleolar interventions for tissue loss. All patients had diabetes, and 53% had chronic renal insufficiency (47% of these were on hemodialysis). The majority of the patients had WIfI stage 3 disease. Technical success was 81%, with a median of one vessel treated per patient. Thirty-four percent of interventions were a direct revascularization of the intended angiosome in the foot. The 30-day major adverse cardiovascular event rate was 0%. The majority of patients underwent some form of planned forefoot surgery (single digit, multiple digits, ray or transmetatarsal amputation). Wound healing at 3 months in those not requiring amputation was 76%. Predictors for wound healing were improved pedal runoff score (<7), absence of infection, direct angiosome revascularization, and absence of end-stage renal disease. Those in whom the primary wounds or the initial amputation site failed to heal ultimately underwent below-knee amputations. The clinical efficacy was 25% ± 7% (mean ± standard error of the mean) at 5 years. The 5-year AFS rate was 33% ± 8%, and the 5-year freedom from major adverse limb events was 27% ± 9%. On Cox proportional multivariate analysis, predictors for AFS were absence of significant coronary disease, postprocedure pedal runoff score <7 (good runoff), WIfI stage <3, and absence of end-stage renal disease.

CONCLUSIONS

Inframalleolar intervention can be successfully performed in high-risk limbs with acceptable short-term results. However, long-term AFS remains poor because of the underlying disease process.

Below-the-ankle Angioplasty: Current Evidence and Future Perspectives

Over 20 million adults in Europe suffer from peripheral arterial disease (PAD). The annual incidence of PAD is approximately 2.4%, while the annual incidence of critical limb ischaemia (CLI), the last and most severe stage of PAD, has been reported to be 0.4%. Endovascular angioplasty and/or stenting of infrapopliteal disease is, today, an established treatment for critical limb ischaemia. The main technical advantages of endovascular treatment over open bypass surgery include the possibility to revascularise more than one infrapopliteal vessels and, most importantly, to treat outflow pedal vessel disease or even reconstitute the pedal arch. Data of below-the-ankle angioplasty are beginning to sum up and the contribution of pedal arch angioplasty in limb salvage and wound healing are currently under investigation. In this review, currently available data and the future perspectives on below-the-ankle and pedal arch endovascular treatment will be presented.

Outcomes of reintervention for recurrent symptomatic disease after tibial endovascular intervention

OBJECTIVE

Tibial interventions for critical limb ischemia are now commonplace. Restenosis and occlusion remain barriers to durability after intervention. The aim of this study was to examine the patient-centered outcomes of open and endovascular reintervention for symptomatic recurrent disease after a primary isolated tibial endovascular intervention.

METHODS

A database of patients undergoing isolated primary lower extremity tibial endovascular interventions between 2006 and 2016 was retrospectively queried. Patients with recurrent critical ischemia (Rutherford 4 and 5) were identified. Outcomes in this cohort were analyzed, and three groups were defined: endovascular reintervention (ie, a repeated tibial or pedal endovascular intervention), bypass (bypass to a tibial or pedal vessel), and primary amputation (ie, above- or below-knee amputation) on the ipsilateral leg. Patient-oriented outcomes of clinical efficacy (absence of recurrent signs or symptoms of critical ischemia, maintenance of ambulation, and absence of major amputation), amputation-free survival (survival without major amputation), and freedom from major adverse limb events (above-ankle amputation of the index limb or major reintervention, such as new bypass graft or jump or interposition graft revision) were evaluated after the reintervention.

RESULTS

There were 1134 patients (56% male; average age, 59 years) who underwent primary tibial intervention for critical ischemia, and 54% presented with symptomatic restenosis and occlusion. Of the 513 patients with recurrent disease, 58% presented with rest pain and the remainder with ulceration. A repeated tibial endovascular intervention was performed in 64%, open bypass in 19%, and below-knee amputation in 17%. Bypass was employed in patients with a good target vessel, venous conduit, and good pedal runoff. Patient-centered outcomes were better in the bypass group compared with the reintervention group (amputation-free survival, 45% ± 9% vs 27% ± 9% [P < .01]; major adverse limb events, 50% ± 9% vs 31% ± 9% [P < .05]; clinical efficacy, 60% ± 7% vs 30% ± 9% [P < .01], mean ± standard error of the mean at 5 years).

CONCLUSIONS

Tibial interventions for critical ischemia are associated with a high rate of reintervention. In patients with good target vessel, venous conduit, and good pedal runoff, bypass appears more durable than repeated tibial endovascular intervention.

Outcomes of tibial endovascular intervention in patients with poor pedal runoff

OBJECTIVE

Tibial interventions for critical limb ischemia are now commonplace. The aim of this study was to examine the impact of pedal runoff on patient-centered outcomes after tibial endovascular intervention.

METHODS

A database of patients undergoing lower extremity endovascular interventions at a single urban academic medical center between 2006 and 2016 was retrospectively queried. Patients with critical ischemia (Rutherford 5 and 6) were identified. Preintervention angiograms were reviewed in all cases to assess pedal runoff. Each dorsalis pedis, lateral plantar, and medial plantar artery was assigned a score according to the reporting standards of the Society for Vascular Surgery (0, no stenosis >20%; 1, 21%-49% stenosis; 2, 50%-99% stenosis; 2.5, half or less of the vessel length occluded; 3, more than half the vessel length occluded). A foot score (dorsalis pedis + medial plantar + lateral plantar + 1) was calculated for each foot (1-10). Two runoff score groups were identified: good vs poor, <7 and ≥7, respectively. Patient-oriented outcomes of clinical efficacy (absence of recurrent symptoms, maintenance of ambulation, and absence of major amputation), amputation-free survival (survival without major amputation), and freedom from major adverse limb events (above-ankle amputation of the index limb or major reintervention [new bypass graft, jump/interposition graft revision]) were evaluated.

RESULTS

There were 1134 patients (56% male; average age, 59 years) who underwent tibial intervention for critical ischemia, with a mean of two vessels treated per patient and a mean pedal runoff score of 6 (47% had a runoff score ≥7). Overall major adverse cardiac events were equivalent at 30 days after the procedure in both groups. At 5 years, vessels with compromised runoff (score ≥7) had significantly lower ulcer healing (25% ± 3% vs 73% ± 4%, mean ± standard error of the mean [SEM]) and a lower 5-year limb salvage rate (45% ± 6% vs 69% ± 4%, mean ± SEM) compared with those with good runoff (score <7). Patients with poor pedal runoff (score ≥7) had significantly lower clinical efficacy (23% ± 8% vs 38% ± 4%, mean ± SEM), amputation-free survival (32% ± 6% vs 48% ± 5%, mean ± SEM), and freedom from major adverse limb events (23% ± 9% vs 41% ± 8%, mean ± SEM) at 5 years compared with patients with good runoff (score <7).

CONCLUSIONS

Pedal runoff score can identify those patients who will not achieve ulcer healing and patient-centered outcomes after tibial intervention. Defining such subgroups will allow stratification of the patients and appropriate application of interventions.

In Patients with Severe Peripheral Arterial Disease, Revascularization-Induced Improvement in Lower Extremity Ischemia Can Be Detected by Laser Speckle Contrast Imaging of the Fluctuation in Blood Perfusion after Local Heating

BACKGROUND

We previously reported the utility of the perfusion value (PV) fluctuation slope for detecting severe ischemia in the lower limb. Our approach was based on a thermal load test mimicking the well-known physiological reaction termed "cold-induced vasodilation," which is known to occur as a 3-phase phenomenon. The slope parameter quantifies the decrease in PVs accompanying the relative cooling (third phase) following the transient increase in blood flow (second phase) induced by the applied thermal load. This phenomenon of "relative" cold-induced vasodilation (rCIVD) can be monitored using laser speckle contrast imaging (LSCI) after applying the thermal load (LTL test). Here, we aimed to determine whether the slope parameter obtained via the LTL test also reflects the improvement in hemodynamics after revascularization.

METHODS

The study enrolled 16 patients (18 limbs), who underwent revascularization for peripheral arterial disease (PAD). The measurements were performed at 2 sites in each limb (in total, 34 sites; 2 sites in one patient were excluded because of significant movement during the measurement). For each site, we recorded the slope describing the behavior of PVs (decrease or plateau) in the third phase of rCIVD, following the initial, heating-induced increase in perfusion (second phase of rCIVD). The plateau group (group P), which included patients with an abnormal rCIVD, and the decrease group (group D), which included patients with a normal rCIVD, were defined based on perfusion slope values of <0.20 and ≥ 0.20 perfusion units/min, respectively. We also quantified the transient increase in perfusion (from baseline to peak) as a descriptor of perfusion behavior during the second phase of rCIVD.

RESULTS

In group P, the change in median values (25-75%) of the slope, transcutaneous oxygen tension, and ankle-brachial index (ABI) from before to after operation was (-0.02 [-0.04 to 0.02]; 4 [1-11]; and 0.08 [0-0.27]) to (0.39 [0.32-0.59]; 46 [37-54]; and 0.81 [0.72-0.90]). Conversely, in group D, the change in the median values of the slope, transcutaneous oxygen tension, and ABI between before and after operation was (0.38 [0.32-0.49]; 40.5 [35-45]; and0.58 [0.57-0.65]) to (0.44 [0.30-0.64]; 52 [43-56]; and 0.92 [0.81-0.99]). Sites exhibiting perfusion pattern of group D in the third phase of rCIVD showed no significant change in slope after revascularization (P = 0.21), whereas the slope in group P increased significantly after revascularization, becoming similar to the postoperative slopes in group D (P = 0.81). The amount of transient increase in perfusion, which quantified the behavior in the second phase of rCIVD, showed a similar behavior. Preoperatively, all patients in group P had rest pain and/or ulcer of the foot, whereas only few patients in group D had such symptoms.

CONCLUSIONS

Normal rCIVD response in the LTL test indicates less-than-severe ischemia, while abnormal rCIVD response measured via the LTL test indicates severe ischemic symptoms, such as critical limb ischemia. Notably, patients with an abnormal rCIVD response can develop a normal rCIVD response following revascularization, thereby reflecting an improvement in blood flow. The LTL test assessing rCIVD response can be useful for detecting severe limb ischemia, such as critical limb ischemia (CLI), and determining the departure from severe limb ischemia by revascularization.

Femoro-Supragenicular Popliteal Bypass with a Bridging Stent Graft in a Diffusely Diseased Distal Target Popliteal Artery: Alternative to Below-Knee Popliteal Polytetrafluoroethylene Bypass

Background

Lesions in distal target arteries hinder surgical bypass procedures in patients with peripheral arterial occlusive disease.

Methods

Between April 2012 and October 2015, 16 patients (18 limbs) with lifestyle-limiting claudication (n=12) or chronic critical limb ischemia (n=6) underwent femoral–above-knee (AK) polytetrafluoroethylene (PTFE) bypass grafts with a bridging stent graft placement between the distal target popliteal artery and the PTFE graft. Ring-supported PTFE grafts were used in all patients with no available vein for graft material. Follow-up evaluations assessed clinical symptoms, the ankle-brachial index, ultrasonographic imaging and/or computed tomography angiography, the primary patency rate, and complications.

Results

All procedures were successful. The mean follow-up was 12.6 months (range, 11 to 14 months), and there were no major complications. The median baseline ankle-brachial index of 0.4 (range, 0.2 to 0.55) significantly increased to 0.8 (range, 0.5 to 1.0) at 12 months (p<0.01). The primary patency rate at 12 months was 83.3%. The presenting symptoms resolved within 2 weeks.

Conclusion

In AK bypasses with a diffusely diseased distal target popliteal artery or when below-knee (BK) bypass surgery is impossible, this procedure could be clinically effective and safe when used as an alternative to femoral-BK bypass surgery.

Outcomes of Isolated Tibial Endovascular Intervention for Rest Pain in Patients on Dialysis

BACKGROUND

Tibial interventions for critical limb ischemia are frequent in patients with end-stage renal disease (ESRD) presenting with critical ischemia. The aim of this study was to examine impact of ESRD on the patient-centered outcomes following tibial endovascular Intervention for rest pain.

METHODS

A database of patients undergoing lower extremity endovascular interventions between 2006 and 2016 was retrospectively queried. Patients with rest pain (Rutherford 4) were identified. Patients with claudication (Rutherford 1 to 3) and tissue loss (Rutherford 5 and 6) were excluded. Patients were categorized by the presence or absence of ESRD. Patient-orientated outcomes of clinical efficacy (CE; absence of recurrent symptoms, maintenance of ambulation, and absence of major amputation), amputation-free survival (AFS; survival without major amputation), and freedom from major adverse limb events (MALEs; above ankle amputation of the index limb or major reintervention new bypass graft, jump/interposition graft revision) were evaluated.

RESULTS

A total of 829 patients (56% male, average age 59 years; 658 nonhemodialysis [non-HD] and 171 HD) underwent isolated tibial intervention in one leg for rest pain. Technical success was 99% with a median of 2 vessels treated per patient. There was no difference in the distribution of Trans-Atlantic Inter-Society Consensus I lesions, but both the modified Society for Vascular Surgery (SVS) runoff score and the pedal runoff score were worse in the HD group. The 30-day major adverse cardiac events and 30-day MALEs were equivalent in both groups. CE was 38 ± 9% and 19 ± 8% at 5 years for the non-HD and HD groups, respectively (P < 0.01). Overall, AFS was 45 ± 8% and 18 ± 9% at 5 years for the non-HD and HD groups, respectively (P < 0.01). Freedom from MALE was 41 ± 9% and 21 ± 8% at 5 years for the non-HD and HD groups, respectively (P < 0.01).

CONCLUSIONS

Patients with ESRD who present with rest pain have equivalent short-term outcomes to those not on dialysis but do not achieve long-term satisfactory CE and AFS after isolated tibial intervention for rest pain.

Submillimeter Diameter Poly(Vinyl Alcohol) Vascular Graft Patency in Rabbit Model

Microvascular surgery is becoming a prevalent surgical practice. Replantation, hand reconstruction, orthopedic, and free tissue transfer procedures all rely on microvascular surgery for the repair of venous and arterial defects at the millimeter and submillimeter levels. Often, a vascular graft is required for the procedure as a means to bridge the gap between native arteries. While autologous vessels are desired for their bioactivity and non-thrombogenicity, the tedious harvest process, lack of availability, and caliber or mechanical mismatch contribute to graft failure. Thus, there is a need for an off-the-shelf artificial vascular graft that has low thrombogenic properties and mechanical properties matching those of submillimeter vessels. Poly(vinyl alcohol) hydrogel (PVA) has excellent prospects as a vascular graft due to its bioinertness, low thrombogenicity, high water content, and tunable mechanical properties. Here, we fabricated PVA grafts with submillimeter diameter and mechanical properties that closely approximated those of the rabbit femoral artery. In vitro platelet adhesion and microparticle release assay verified the low thrombogenicity of PVA. A stringent proof-of-concept in vivo test was performed by implanting PVA grafts in rabbit femoral artery with multilevel arterial occlusion. Laser Doppler measurements indicated the improved perfusion of the distal limb after implantation with PVA grafts. Moreover, ultrasound Doppler and angiography verified that the submillimeter diameter PVA vascular grafts remained patent for 2 weeks without the aid of anticoagulant or antithrombotics. Endothelial cells were observed in the luminal surface of one patent PVA graft. The advantageous non-thrombogenic and tunable mechanical properties of PVA that are retained even in the submillimeter diameter dimensions support the application of this biomaterial for vascular replacement in microvascular surgery.

Outcomes of Isolated Tibial Endovascular Interventions for Tissue Loss in CLI Patients on Hemodialysis

PURPOSE

To compare the objective performance goals (OPGs) and patient-centered outcomes of isolated tibial interventions in patients with tissue loss who were on hemodialysis (HD) to patients with tissue loss who were not on HD.

METHODS

Interrogation of a prospectively maintained database identified 242 critical limb ischemia (CLI) patients who underwent isolated tibial interventions for tissue loss in a single limb between 2007 and 2012. The 78 patients (mean age 66±12 years; 44 men) on HD were compared with 164 patients (mean age 50±13 years; 82 men) who were not on HD. There was an equal distribution of the tibial vessels treated; 152 (63%) patients had more than one treated tibial vessel. Patient-centered outcomes of clinical efficacy (absence of recurrent symptoms, maintenance of ambulation, and no major amputation), amputation-free survival (AFS), and freedom from major adverse limb events (MALE) were evaluated. The Society for Vascular Surgery OPGs were defined at 30 days and 1 year.

RESULTS

The 30-day major adverse cardiac events was significantly higher (p=0.004) in the HD group (5, 5%) compared with the no-HD group (0%), but both remained under the stated OPG of ≤10%. The 30-day MALE rates were significantly higher than the stated ≤9% OPG at 13% and 18% for the no-HD and HD groups, respectively. At 1 year, the rates for AFS, freedom from MALE, limb salvage, and survival did not achieve the stated Society for Vascular Surgery OPGs in the HD group. Clinical efficacy was 61% and 25% at 3 years for the no-HD and HD groups, respectively (p<0.01). Overall, AFS was 54% and 22% and freedom from MALE was 56% and 27% at 3 years for the no-HD and HD groups, respectively (both p<0.01).

CONCLUSION

Tibial intervention for tissue loss in patients on HD is a valid treatment option but is associated with a high MALE rate. Three-year outcomes remain relatively poor, with <25% success in terms of clinical efficacy and AFS.

Association of foot ulcer with tibial artery calcification is independent of peripheral occlusive disease in type 2 diabetes

AIMS

To determine the relationship between foot ulcers, arterial calcification, and peripheral occlusive disease in patients with type 2 diabetes.

METHODS

We performed a cross-sectional study on 162 patients with type 2 diabetes who underwent assessment of tibial artery calcification (TAC) by non-contrasted CT scan. Peripheral artery occlusive disease was assessed by angiography. Foot status including the presence or absence of ulcers was documented at presentation. A multivariable logistic regression model was used to evaluate the association between foot ulcers, arterial calcification, and the extent of peripheral atherosclerotic occlusive disease.

RESULTS

Patients with foot ulcers (N=31) were more likely to be older and have a history of tobacco use. They were also more likely to have higher TAC scores (median [IQR]: 4324.6 [609.9, 11163.6] vs. 9.4 [0.0, 343.9], P<0.001) and more advanced peripheral artery occlusive disease (occlusion index 5.5 [4.8, 6.4] vs. 2.2 [1.0, 3.6], P<0.001). Foot ulcer was strongly associated with elevated TAC scores in a multivariable regression model (odds ratio [95% CI]=2.76 [1.61, 4.75], P=0.0002).

CONCLUSIONS

There is a strong association between arterial calcification and diabetic foot ulcers that persists after adjusting for the extent of atherosclerosis in patients with type 2 diabetes.

Using risk models to improve patient selection for high-risk vascular surgery

Vascular surgeons frequently perform procedures aimed at limiting death, stroke, or amputation on patients who present with diseases such as aortic aneurysms, carotid atherosclerosis, and peripheral arterial occlusive disease. However, now more than ever surgeons must balance the potential benefits associated with these interventions with the risks of physiologic insult for these elderly patients, who often have significant comorbidity burdens and the potential for costly complications. In this paper, we highlight how regional and national datasets can help surgeons identify which patients are most likely to benefit from vascular operations and which patients are most likely to suffer complications in the postoperative period. By using these guidelines to improve patient selection, our risk models can help patients, physicians, and policymakers improve the clinical effectiveness of surgical and endovascular treatments for vascular disease.

Limb revascularization feasibility in diabetic patients with critical limb ischemia: results from a cohort of 344 consecutive unselected diabetic patients evaluated in 2009

AIMS

To evaluate the feasibility of peripheral revascularization by angioplasty (PTA) or bypass grafting (BPG) in diabetic patients with critical limb ischemia (CLI).

METHODS

All diabetic patients referred to our Diabetic Foot Centre for foot lesion or rest pain were assessed for the presence of CLI as assessed by the TASC criteria. All patients underwent angiography that was evaluated jointly by an interventional radiologist, a vascular surgeon and a diabetologist of the diabetic foot care team.

RESULTS

During 2009, 344 diabetics were admitted because of CLI in a total of 360 limbs. PTA was performed in 308 (85.6%) limbs, and BPG was performed in 40 (11.1%) limbs in which PTA was not feasible. Revascularization could not be carried out in 12 (3.3%) limbs due to the lack of target vessel (9 limbs) or high surgical risk (3 limbs). According to the judgement of the vascular surgeon, BPG was anatomically feasible in 180 (58.4%) of the 308 limbs that underwent PTA. Therefore, considering also the 40 limbs that underwent BPG, surgical revascularization was judged anatomically possible in a total of 220 (61.1%) limbs. At 30 days, 19 (5.3%) above-the-ankle amputations were performed: 8 (66.7%) amputations were performed in the 12 non-revascularized limbs, 8 (2.6%) amputations were performed in the 308 limbs treated with PTA and 3 (7.5%) amputations were performed in the 40 limbs treated with BPG.

CONCLUSIONS

Revascularization by PTA is highly feasible in diabetics with CLI. The feasibility of revascularization by BPG is lower but nonetheless consistent. In centres where both revascularization procedures are available, it is possible to revascularize more than 96% of diabetics with CLI.

Isolated Endarterectomy of Femoral Bifurcation in Critical Limb Ischemia: Is Restoration of Inline Flow Essential?

This retrospective study reviews clinical outcomes of isolated common femoral endarterectomy (CFE) for critical limb ischemia (CLI), in particular whether poor runoff and inability to restore inline flow has negative impact. In 30 patients, runoff was assessed on preoperative angiograms and categorized into groups based on Society of Vascular Surgery criteria. Data were evaluated using Cox Regression survival analysis. Freedom from secondary revascularization was not affected by runoff score (hazard ratio for compromised and poor groups being 1.8 (95% CI 0.16 to 20.8) and 1.47 (95% CI 0.09 to 24.3), respectively; P = .894). Distal inline flow was not achieved in 25 (83%) patients, but this was not associated with significantly worse outcome (P = .295, log-rank test). In conclusion, CFE can be performed in CLI with high technical success and there is no significant effect of runoff score on recurrence of symptoms. Limb salvage can be achieved even if options to restore inline flow are limited.

Failure to achieve clinical improvement despite graft patency in patients undergoing infrainguinal lower extremity bypass for critical limb ischemia

OBJECTIVE

Studies of infrainguinal lower extremity bypass for critical limb ischemia (CLI) have traditionally emphasized outcomes of patency, limb salvage, and death. Because functional outcomes are equally important, our objectives were to describe the proportion of CLI patients who did not achieve symptomatic improvement 1 year after bypass, despite having patent grafts, and identify preoperative factors associated with this outcome.

METHODS

The prospectively collected Vascular Study Group of Northern New England database was used to identify all patients with elective infrainguinal lower extremity bypass for CLI (2003 to 2007) for whom long-term follow-up data were available. The primary composite study end point was clinical failure at 1 year after bypass, defined as amputation or persistent or worsened ischemic symptoms (rest pain or tissue loss), despite a patent graft. Variables identified on univariate screening (inclusion threshold, P < .20) were included in a multivariable logistic regression model to identify independent predictors.

RESULTS

Long-term follow-up data were available for 1012 patients who underwent infrainguinal bypasses for CLI, of which 788 (78%) remained patent at 1 year. Of these, 79 (10%) met criteria for the composite end point of clinical failure: 21 (2.7%) for major amputations and 58 (7.4%) for persistent rest pain or tissue loss. In multivariable analysis, significant predictors of clinical failure included dialysis dependence (odds ratio [OR], 3.74; 95% confidence interval [CI], 1.84-7.62; P < .001) and preoperative inability to ambulate independently (OR, 2.17; 95% CI, 1.26-3.73; P = .005). A history of coronary artery bypass graft or percutaneous coronary intervention was protective (OR, 0.52; 95% CI, 0.29-0.93; P = .03).

CONCLUSIONS

After infrainguinal lower extremity bypass for CLI, 10% of patients with a patent graft did not achieve clinical improvement at 1 year. Preoperative identification of this specific patient subgroup remains challenging. To improve surgical decision making and the overall care of CLI patients, further emphasis needs to be placed on functional outcomes in addition to traditional surgical end points.

Critical limb ischemia

Critical limb ischemia (CLI), defined as chronic ischemic rest pain, ulcers, or gangrene attributable to objectively proven arterial occlusive disease, is the most advanced form of peripheral arterial disease. Traditionally, open surgical bypass was the only effective treatment strategy for limb revascularization in this patient population. However, during the past decade, the introduction and evolution of endovascular procedures have significantly increased treatment options. In a certain subset of patients for whom either surgical or endovascular revascularization may not be appropriate, primary amputation remains a third treatment option. Definitive high-level evidence on which to base treatment decisions, with an emphasis on clinical and cost effectiveness, is still lacking. Treatment decisions in CLI are individualized, based on life expectancy, functional status, anatomy of the arterial occlusive disease, and surgical risk. For patients with aortoiliac disease, endovascular therapy has become first-line therapy for all but the most severe patterns of occlusion, and aortofemoral bypass surgery is a highly effective and durable treatment for the latter group. For infrainguinal disease, the available data suggest that surgical bypass with vein is the preferred therapy for CLI patients likely to survive 2 years or more, and for those with long segment occlusions or severe infrapopliteal disease who have an acceptable surgical risk. Endovascular therapy may be preferred in patients with reduced life expectancy, those who lack usable vein for bypass or who are at elevated risk for operation, and those with less severe arterial occlusions. Patients with unreconstructable disease, extensive necrosis involving weight-bearing areas, nonambulatory status, or other severe comorbidities may be considered for primary amputation or palliative measures.

Factors associated with amputation or graft occlusion one year after lower extremity bypass in northern New England

BACKGROUND

Optimal patient selection for lower extremity bypass surgery requires surgeons to predict which patients will have durable functional outcomes following revascularization. Therefore, we examined risk factors that predict amputation or graft occlusion within the first year following lower extremity bypass.

METHODS

Using our regional quality-improvement initiative in 11 hospitals in northern New England, we studied 2,306 lower extremity bypass procedures performed in 2,031 patients between January 2003 and December 2007. Sixty surgeons contributed to our database, and over 100 demographic and clinical variables were abstracted by trained researchers. Cox proportional hazards models were used to generate hazard ratios and surrounding 95% confidence intervals (CIs) for our combined outcome measure of major amputation (above-knee or below-knee) or permanent graft occlusion (loss of secondary patency) occurring within the first year postoperatively.

RESULTS

We found that within our cohort of 2,306 bypass procedures 17% resulted in an amputation or graft occlusion within 1 year of surgery. Of the 143 amputations performed (8% of all limbs undergoing bypasses), 17% occurred in the setting of a patent graft. Similarly, of the 277 graft occlusions (12% of all bypasses), 42% resulted in a major amputation. We identified eight preoperative patient characteristics associated with amputation or graft occlusion in multivariate analysis: age <50, nonambulatory status preoperatively, dialysis dependence, diabetes, critical limb ischemia, need for venovenostomy, tarsal target, and living preoperatively in a nursing home. While patients with no risk factors had 1-year amputation/occlusion rates that were <1%, patients with three or more risk factors had a nearly 30% chance of suffering amputation or graft occlusion by 1 year postoperatively. When we compared risk-adjusted rates of amputation/occlusion across centers, we found that one center in our region performed significantly better than expected (observed/expected ratio 0.7, 95% CI 0.6-0.9, p < 0.04).

CONCLUSION

Preoperative risk factors allow surgeons to predict the risk of amputation or graft occlusion following lower extremity bypass and to more precisely inform patients about their operative risk and functional outcomes. Additionally, our model facilitates comparison of risk-adjusted outcomes across our region. We believe quality-improvement measures such as these will allow surgeons to identify best practices and thereby improve outcomes across centers.

A prognostic model for amputation in critical lower limb ischemia

In a (negative) multicenter randomized trial on management for inoperable critical lower limb ischemia, comparing spinal cord stimulation and best medical treatment, a number of pre-defined factors were analyzed for prognostic value. We included a radiological arterial disease score, modified from the SVS/ISCVS runoff score. The purpose of this analysis was to evaluate clinical factors and commonly used circulatory measurements for prognostic modeling in patients with critical lower limb ischemia. We determined the incidence of amputation and its relation to various pre-defined risk factors. A total of 120 patients with critical limb ischemia were included in the study. The integrity of circulation in the affected limb was evaluated on five levels: suprainguinal, infrainguinal, popliteal, infrapopliteal and pedal. A total radiological arterial disease score was calculated from 1 (full integrity of circulation) to 20 (maximally compromised state). We used Cox regression analysis to quantify prognostic effects and differential treatment (predictive) effects. Major amputation occurred in 33% of the patients at 6 months and in 51% at 2 years. The presence of ischemic skin lesions and the radiological arterial disease score were independent prognostic factors for amputation. Patients with ulcerations or gangrene had a higher amputation risk (hazard ratio 2.38, p = 0.018 and 2.30, p = 0.036 respectively) as well as patients with a higher radiological arterial disease score (hazard ratio 1.17 per increment, p = 0.003). We did not observe significant interactions between prognostic factors and the effect of spinal cord stimulation. In conclusion, in patients with critical lower limb ischemia, the presence of ischemic skin lesions and the described radiological arterial disease score can be used to estimate amputation risk.

Patterns of artery disease in 450 patients undergoing revascularization for critical limb ischemia: implications for clinical trial design

OBJECTIVE

The pattern and distribution of arterial occlusions and stenoses in patients with critical limb ischemia presenting at two academic medical centers was described.

METHODS

From January 1998 to December 2006, 450 consecutive critical limb ischemia patients who underwent arteriography and infrainguinal revascularization at the University of Colorado Health Sciences Center or Southern Illinois University were retrospectively evaluated. Demographics, clinical morbidities, and Fontaine stage were recorded. The arterial tree was categorized into three groups: the aorta and iliac arteries (A-I); the common femoral, superficial femoral, and profunda femoral arteries (Fem); and the popliteal and tibial arteries (Pop-Tib). Arterial segments within groups were categorized as subcritical stenoses (patent or <50% stenoses), critical stenoses (single or multiple >50% stenoses), or occluded (segmental occlusions of any length). Patients with diabetes mellitus, end-stage renal disease, and Fontaine stage (III vs IV) were analyzed for differing disease patterns according to their chart history.

RESULTS

Occlusive disease was present in 5% in all arterial segments (A-I + Fem + Pop-Tib), in 1% in the A-I + Fem group, in 2% in the A-I + Pop-Tib group, in 3% in A-I group, in 4% in the Fem group, in 30% in the Fem + Pop-Tib group, and in 55% in the Pop-Tib group. Descriptive comparisons among subgroups demonstrated a 61% to 69% prevalence of popliteal and tibial occlusive patterns in patients with diabetes mellitus, end-stage renal disease, and Fontaine stage IV. Furthermore, 65% of patients with Pop-Tib occlusions had associated critical stenoses in the proximal arterial groups.

CONCLUSION

More than half of critical limb ischemia patients undergoing infrainguinal revascularization have arterial occlusions in the popliteal or tibial arterial segments, or both, with associated critical stenoses in the femoral arterial segments, which is even greater in the subgroups with diabetes mellitus, end-stage renal disease, and Fontaine stage IV. Knowledge of such occlusive patterns is important for the development of novel infrainguinal endovascular and angiogenesis therapies for critical limb ischemia.

Vascular assessment and reconstruction of the ischemic diabetic limb

Peripheral artery disease (PAD) is a common finding among diabetic patients and is usually secondary to atherosclerosis. PAD in diabetic patients tends to be more malignant, presenting with diffuse involvement and more complications. Unless the ischemia is addressed concomitantly with local problems in the foot, resulting problems can lead to extensive tissue loss and major amputation. Lower extremity atherosclerotic complications in diabetic patients require considerable dedication and aggressiveness if limb loss is to be avoided.

Vascular involvement in diabetic subjects with ischemic foot ulcer: a new morphologic categorization of disease severity

OBJECTIVES

Arteriographic lesions of diabetic subjects with critical limb ischemia (CLI) and ischemic foot ulcer were reviewed retrospectively, to provide new criteria for stratification of these patients on the basis of their vascular involvement.

PATIENTS

In 417 consecutive CLI diabetic subjects with ischemic foot ulcer undergoing lower limb angiography, lesions were defined as stenosis or occlusion, localization, and length (<5 cm, 5-10 cm, >10 cm). In a subgroup of 389 subjects, foot arteries also were evaluated. Patients then were categorized into 7 classes of progressive vascular involvement based on angiographic findings.

RESULTS

Of the 2893 found lesions (55% occlusions) 1% were in the iliac arteries, whereas 74% were in below-the-knee (BTK) arteries. Sixty-six % of all BTK lesions were occlusions, and 50% were occlusions >10 cm (p<0.001 vs proximal segments). Occlusions of all BTK were present in 28% of patients, although there was patency of at least one foot artery in 55% of patients. The morphologic Class 4 (two arteries occluded and multiple stenoses of tibial/peroneal and/or femoral/popliteal vessels) was the most common (36%). An inverse correlation between morphologic class and TcPO2 was observed (r=-0.187, p=0.003).

CONCLUSIONS

In CLI diabetic subjects with ischemic foot ulcer, the vascular involvement is extremely diffuse and particularly severe in tibial arteries, with high prevalence of long occlusions. A new morphologic categorization of these patients is proposed.

Peripheral atherectomy in TransAtlantic InterSociety Consensus type C femoropopliteal lesions for limb salvage

BACKGROUND

The optimal therapy for TransAtlantic Societal Consensus (TASC) type C femoropopliteal lesions remains a critical issue in the treatment of infrainguinal occlusive disease. The purpose of this study was to evaluate the outcome of limbs with TASC C femoropopliteal lesions and critical limb ischemia treated with the FoxHollow SilverHawk atherectomy catheter.

METHODS

From September 2004 to September 2005, 18 consecutive femoropopliteal procedures performed in 17 limbs in 16 patients were reviewed. Demographic data, baseline angiographic findings, and indications for the procedures were recorded. Clinical outcomes including symptom resolution and limb salvage were determined for the 17 primary procedures. Hemodynamic improvement was compared by using the paired Student t test. Stenosis-free patency was determined by the Kaplan-Meier method.

RESULTS

The mean age was 72.5 years (range, 47-88 years). Fifty percent of the patients had four or more of the following risk factors: hypertension, diabetes, tobacco use, hyperlipidemia, renal insufficiency, and coronary artery disease. The indication was tissue loss in 13 limbs and rest pain in 4. All patients had a second level of disease, either inflow or tibial/pedal, which was treated concurrently when appropriate. Initial resolution of symptoms was achieved in 12 limbs, and partial healing was achieved in 2 others. Early amputation was necessary in the remaining three patients, but this was likely due to severe inframalleolar disease and advanced forefoot ischemia at the time of presentation. Five patients have remained symptom-free without restenosis at a mean follow-up of 6 months. Two patients have required late amputation for hemodynamic failure. The ankle-brachial index improved from 0.39 +/- 0.08 (mean +/- SEM) before surgery to 0.75 +/- 0.08 in the immediate postoperative period (P = .02). However, it returned toward baseline at 6 months after surgery, with a mean of 0.48 +/- 0.07. Stenosis-free patency of the femoropopliteal segment was 22% at 12 months.

CONCLUSIONS

Peripheral atherectomy can achieve good early clinical and hemodynamic success in patients with TASC C lesions and critical limb ischemia. However, mid-term restenosis rates are high in this challenging cohort of patients.

Assessment of critical limb ischemia in patients with diabetes: comparison of MR angiography and digital subtraction angiography

OBJECTIVE

The purpose of our study was to evaluate the diagnostic accuracy of hybrid MR angiography by comparison with digital subtraction angiography (DSA) in diabetic patients with critical limb ischemia.

SUBJECTS AND METHODS

Thirty-one patients prospectively underwent both hybrid MR angiography and DSA. The hybrid MR angiography study consisted of high-resolution MR angiography of a single calf and foot using a contrast-enhanced 3D gradient-echo volumetric interpolated breath-hold examination with surface coils, followed by three-station bolus chase MR angiography with a dedicated peripheral vascular coil. Two blinded reviewers separately analyzed maximum-intensity-projection hybrid MR angiograms and DSA images. The peripheral vessels were divided into 10 anatomic segments for review. The status of each segment was graded as normal, stenosis less than 50% in diameter, stenosis greater than 50%, or occluded. The sensitivity and specificity of hybrid MR angiography were determined using DSA as the gold standard. Treatment options were considered separately from the results of each examination.

RESULTS

Among 310 analyzed segments, the sensitivities of hybrid MR angiography for stenosis and occlusion were, respectively, 95% and 95% for reviewer 1 and 96% and 90% for reviewer 2. The specificities of hybrid MR angiography for stenosis and occlusion were, respectively, 98% and 98% for reviewer 1 and 98% and 99% for reviewer 2. In 25 patients (81%), the quality of bolus chase MR angiography images was insufficient to assess runoff arteries. All treatments proposed on the basis of DSA findings were endorsed by hybrid MR angiography findings. Eleven more treatments were formulated on the basis of hybrid MR angiography findings. Of these, four were due to overestimation of stenosis on MR angiography and seven were due to the detection of patent infrageniculate arteries on hybrid MR angiography that were not detected on DSA.

CONCLUSION

Hybrid MR angiography depicts runoff arteries not seen on DSA. Hybrid MR angiography may be useful for treatment planning in selected diabetic patients with critical limb ischemia.

Healing of Transmetatarsal Amputation in the Diabetic Patient: Is Angiography Predictive?

Transmetatarsal amputation (TMA) is a durable reconstruction in the diabetic patient with limited forefoot gangrene. However, predicting TMA healing remains difficult. Our goals were to (1) determine the success rate of TMA and (2) identify factors predictive of TMA healing, in particular arterial foot anatomy. A retrospective review of all diabetic patients undergoing TMA was done. Blood supply to the foot was classified as mostly anterior (anterior tibial and/or dorsalis pedis artery), mostly posterior (posterior tibial or plantar arteries), or equally distributed (both systems patent or peroneal runoff). Foot vessels were assigned runoff scores from 0 to 3 according to Society for Vascular Surgery/International Society for Cardiovascular Surgery (SVS/ISCVS) criteria. Forty-four TMAs in 29 men and 12 women were reviewed. Revascularization was done in 35 cases. In nine cases (20%), no bypass was deemed necessary (n = 7) or feasible (n = 2). Blood flow to the foot was deemed mostly anterior in 16 cases, mostly posterior in 17 cases, and equally distributed in 11. The TMA was left open in 19 cases and closed with staples or sutures in the rest. Limb salvage was achieved in 30 cases (68%) at a median follow-up of 48 weeks. Three of the four patients on dialysis required leg amputation (75%) vs. 11 of the 40 (27%) nondialysis patients (p = 0.05). When the TMA was left open, leg amputation was more likely (58%) than when closed primarily (12%) (p < 0.01). No angiographic factors were predictive of limb salvage. The need for revascularization was not associated with limb loss, although both patients with no feasible bypass option required below-knee amputation. TMA healing can be expected in a majority of diabetic patients after adequate revascularization but cannot be predicted by angiographic findings. Efforts should be made to achieve primary wound closure.

Outcomes following distal bypass graft occlusion in diabetics

The objectives of this study were to define clinical outcomes following distal bypass graft occlusion in diabetic patients and identify factors predictive of limb loss. A retrospective review was conducted of all distal graft occlusions over a 5-year period in diabetic patients. Popliteal grafts, perioperative (30 days) failures, and redo distal bypasses were excluded. Eighty grafts were studied (43 cases done for ulcers, 31 for gangrene, and 6 for rest pain). Time to occlusion averaged 13 +/- 17 months post-bypass (median 6 months). Interventions following graft occlusion (lysis, thrombectomy, revision, or new bypass) were carried out in only 26 cases, leading to limb salvage in 11 cases (42%). This compares to a limb salvage rate of 54% in the 54 cases where no intervention was done ( p = NS). The overall amputation rate was 50% (14 AKAs and 26 BKAs). The interval between graft occlusion and amputation averaged 2 +/- 2 months. Limbs saved were followed an average of 14 +/- 11 months after graft occlusion. The presence of a foot wound (new or old) was associated with a higher likelihood of amputation (67% vs. 32% for cases with no foot wounds at the time of bypass failure; p < 0.005). In cases requiring an amputation, the toebrachial index averaged 0 +/- 0 post-bypass failure vs. 0.2 +/- 0.2 in cases where limbs were saved ( p < 0.05). Patients with congestive heart failure or who were nonambulatory at the time of graft occlusion were more likely to end up with an amputation ( p < 0.05). Limb loss was also more likely when gangrene had been the initial operative indication. No other factors were predictive of limb loss, including vein configuration, inflow or outflow level, prior bypass revision, known graft stenosis, time to occlusion, age, gender, other medical conditions, pre- or post-bypass ABI or TBI, graft velocities, or use of anticoagulants. Limb loss following primary distal bypass failure in diabetics is high. Repeat interventions have limited success. The findings justify aggressive programs of graft maintenance, and vigorous attempts at early closure of foot wounds.