Predictors for the Healing of Transmetatarsal Amputations: Retrospective Study of 91 Amputations

This retrospective study reviewed 80 consecutive patients (mean age 62 years; range 21–91 years) who underwent 91 transmetatarsal amputations (TMAs) between 1995 and 2003. The mean follow-up was 12 ± 1.36 months. Sixty-two TMAs healed initially (group 1), whereas 29 TMAs did not heal by 3 months (group 2). At the final examination, in groups 1 and 2, 63 of 91 (69%) limbs were healed. Of the 28 limbs that did not heal, 25 of 28 (89%) required further proximal amputation. Initial healing correlated significantly with the ability to ambulate ( p < .0001) and overall limb salvage ( p < .0001). In group 1, 20 of 27 (74%) limbs that were revascularized healed ( p = .0336). Nonhealing amputations were associated with end-stage renal disease (13 of 19; 68%) ( p = .0209) and leukocytosis (13 of 19; 68%) ( p = .0052).

Abstract 325: Non-Invasive Volumetric Assessment of Angiosome Perfusion in Diabetic Patients With Critical Limb Ischemia and Non-Healing Ulcers Using Radiotracer Imaging

Introduction: Impaired lower extremity perfusion is a hallmark of peripheral vascular disease (PVD) and is particularly problematic in diabetic patients, who suffer from high rates of PVD, ulceration, and lower extremity amputation. The ability to non-invasively detect deficits in microvascular perfusion within vascular territories, or angiosomes, of the feet may provide information related to tissue viability, assist with classification of diabetic wounds, and guide future therapeutic interventions. In this study, we sought to quantify volumetric microvascular perfusion within specific angiosomes containing non-healing foot ulcers in diabetic patients with critical limb ischemia.

Methods: Twenty-eight diabetic patients (mean age, 68 ± 13 yrs) with non-healing ulcers underwent SPECT/CT imaging of the feet following a resting injection of 99m Tc-tetrofosmin (dose, 550.6 ± 37 Mbq). CT images were segmented into five angiosomes and used for quantifying relative radiotracer uptake (Fig. 1A), expressed as standardized uptake values (SUVs). SUVs were assessed for each patient in the angiosome containing the non-healing ulcers, which were rated using the Wagner Grade Classification.

Results: SPECT/CT imaging allowed for visualization of resting perfusion deficits in ulcer sites (Fig. 1B) and quantitative image analysis revealed variability in angiosome perfusion based on Wagner Grade of ulcers. Angiosomes containing Wagner Grade IV ulcers exhibited significantly lower SUVs when compared to SUVs of angiosomes containing Wagner Grade I, II, and III ulcers (Fig. 1C).

Conclusions: SPECT/CT imaging provides a useful non-invasive tool for evaluating a wide clinical spectrum of ulcers within associated angiosomes of the foot and can be performed without requiring pharmacological or exercise stress. Future application of SPECT/CT imaging may provide additional value for detection and targeting of ischemic tissue for therapeutic interventions.

Abstract 297: SPECT/CT Imaging of Regional Foot Perfusion Provides a Quantitative Index for Evaluation of Targeted Revascularization in the Diabetic Foot

Introduction: No standard quantitative imaging approach exists to evaluate volumetric changes in tissue perfusion in the lower extremities following medical treatment. In this study, we develop and apply a three-dimensional model of the foot for evaluation of regional changes in perfusion following revascularization in diabetic patients with non-healing foot ulcers. We hypothesize that SPECT/CT imaging will permit quantification of regional improvements in tissue perfusion in territories of the foot that contain non-healing ulcers, allowing for quantitative evaluation of revascularization procedures.

Methods: Resting 99m Tc-tetrofosmin (dose 554.0 ± 26.6 MBq) SPECT/CT was performed on diabetic patients (n=5; 64 ± 15 yrs) before and 1-3 days after lower extremity angioplasty and/or stenting. The CT attenuation scans were used to define five regions of interest (ROIs) in the foot and for quantification of relative changes in regional perfusion with 99m Tc-tetrofosmin SPECT (Fig. 1A). Radiotracer uptake for each ROI was normalized to injected dose and ROI volume, and expressed as a percent change from baseline value.

Results: SPECT/CT imaging demonstrated quantitative improvements in regional tissue perfusion in ROIs containing non-healing ulcers for 4 out of 5 patients following revascularization (Fig. 1B). The single patient demonstrating a negative response (11.7% decrease in perfusion) underwent eventual amputation.

Conclusions: Early changes in tissue perfusion following revascularization can be non-invasively evaluated in specific vascular territories of the foot using SPECT/CT imaging and may be associated with wound healing and limb salvage outcomes.

Economic development and diabetes prevalence in MENA countries: Egypt and Saudi Arabia comparison

Diabetes is increasing in epidemic proportions globally, exhibiting the most striking increase in third world countries with emerging economies. This phenomena is particularly evident in the Middle East and North Africa (MENA) region, which has the highest prevalence of diabetes in adults. The most concerning indirect cost of diabetes is the missed work by the adult population coupled with the economic burden of loss of productivity. The major drivers of this epidemic are the demographic changes with increased life expectancy and lifestyle changes due to rapid urbanization and industrialization. Our focus is to compare MENA region countries, particularly Egypt and Saudi Arabia, in terms of their economic development, labor force diversity and the prevalence of diabetes.

Contemporary assessment of foot perfusion in patients with critical limb ischemia

Significant progress in limb salvage for patients with peripheral arterial disease and critical limb ischemia has occurred in the past 2 decades. Improved patient outcomes have resulted from increased knowledge and understanding of the disease processes, as well as efforts to improve revascularization techniques and enhance patient care after open and endovascular procedures. An imaging modality that is noninvasive, fast, and safe would be a useful tool for clinicians in assessing lower-extremity perfusion when planning interventions. Among the current and emerging regional perfusion imaging modalities are transcutaneous oxygen monitoring, hyperspectral imaging, indocyanine green dye-based fluorescent angiography, nuclear diagnostic imaging, and laser Doppler. These tests endeavor to delineate regional foot perfusion to guide directed revascularization therapy in patients with critical limb ischemia and foot ulceration.

New advances in limb salvage

Critical limb ischemia (CLI) is an already significant and growing epidemiologic problem with substantial implications for patient mortality, quality of life, and healthcare costs. Considerable progress has been made in its treatment and prevention; however, poor outcomes, especially with regard to limb loss, warrant further development of treatment options. This article will examine new advances being made in the area of limb salvage for this morbid disease. Open surgical techniques and materials such as distal vein patches and heparin-bonded PTFE will be discussed. Additionally, new developments in endovascular therapies with particular regard to infrapopliteal interventions and drug-eluting stents will be reviewed. Beyond the simple techniques and materials, there is a growing movement in the world of vascular surgery to examine surgical and endovascular interventions with regard to angiosome-oriented revascularization of ulceration and gangrene. This paradigm has the potential to change prioritization and planning of both types of therapies as further research into this concept develops.

Characterization of extracellular signal-regulated kinase 5 levels in human umbilical vein endothelial cells exposed to disturbed and uniform flow

Extracellular signal-regulated kinase 5 (ERK5) has been reported to regulate endothelial cell integrity and protect from vascular dysfunction under continuous laminar flow. However, the effect of flow on ERK5 levels has not been determined. Confluent human umbilical vein endothelial cells (HUVECs) were seeded on fibronectin coated glass slides and serum starved for 2 hours with 1% fetal bovine serum (FBS). HUVECs were then exposed to to and fro flow (TFF), pulsatile forward flow (PFF), or continuous laminar flow (CLF) in a parallel plate flow chamber for up to 2 hours. At the end of experiment, cell lysates were prepared and immunoblotted with antibodies to total ERK5. Both CLF and TFF exhibited a decrease in ERK5 after levels after 2-hour exposure. However, the level of ERK5 for PFF remained the same. Disturbed, but not uniform pulsatile, flow decreases ERK5 levels in HUVECs.

Effect of pulsatile and continuous flow on yes-associated protein

Yes-associated protein (YAP) is a mechanosignaling protein that relays mechanical information to the nucleus by changing its level of phosphorylation. We hypothesize that different flow patterns show differential effect on phosphorylated YAP (pYAP) (S127) and total YAP and could be responsible for flow dependent localization of atherosclerosis. Confluent human umbilical vein endothelial cells (HUVECs) seeded on fibronectin-coated glass slides were exposed to continuous forward flow (CFF) and pulsatile forward flow (PFF) using a parallel plate flow chamber system for 30 minutes. Cell lysates were prepared and immunoblotted to detect the levels of phosphorylated YAP and total YAP. HUVECs exposed to both PFF and CFF showed a mild decrease in the levels of both pYAP (S127) and total YAP. While the levels of pYAP (S127) decreased to 87.85 and 85.21% of static control with PFF and CFF, respectively, the levels of total YAP significantly decreased to 91.31 and 92.27% of static control. No significant difference was seen between CFF and PFF on their effect on pYAP (S127), but both conditions resulted in a significant decrease in total YAP at 30 minutes. The results of this experiment show that the possible effect of different types of flow on YAP is not induced before 30 minutes. Experiments exposing endothelial cells to various types of flow for longer duration of time could help to elucidate the role of YAP in the pathogenesis of atherosclerosis.

Open repair, endovascular repair, and conservative management of true splenic artery aneurysms

OBJECTIVE

True splenic artery aneurysms (SAAs) are a rare but potentially fatal pathology. For many years, open repair (OPEN) and conservative management (CONS) were the treatments of choice, but throughout the last decade endovascular repair (EV) has become increasingly used. The purpose of the present study was to perform a systematic review and meta-analysis evaluating the outcomes of the three major treatment modalities (OPEN, EV, and CONS) for the management of SAAs.

METHODS

A systematic review of all studies describing the outcomes of SAAs treated with OPEN, EV, or CONS was performed using seven large medical databases. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed to ensure a high-quality review. All articles were subject to critical appraisal for relevance, validity, and availability of data regarding characteristics and outcomes. All data were systematically pooled, and meta-analyses were performed on several outcomes, including early and late mortality, complications, and number of reinterventions.

RESULTS

Original data of 1321 patients with true SAAs were identified in 47 articles. OPEN contained 511 patients (38.7%) in 31 articles, followed by 425 patients (32.2%) in CONS in 16 articles and 385 patients (29.1%) in EV in 33 articles. The CONS group had fewer symptomatic patients (9.5% vs 28.7% in OPEN and 28.8% in EV; P < .001) and fewer ruptured aneurysms (0.2% vs 18.4% in OPEN and 8.8% in EV; P < .001), but no significant differences were found in existing comorbidities. CONS patients were usually older and had smaller-sized aneurysms than patients in the OPEN and EV groups. The only identified difference in baseline characteristics between OPEN and EV was the number of ruptured aneurysms (18.4% vs 8.8%; P < .001). OPEN had a higher 30-day mortality than EV (5.1% vs 0.6%; P < .001), whereas minor complications occurred in a larger number of the EV patients. EV required more reinterventions per year (3.2%) compared with OPEN (0.5%) and CONS (1.2%; P < .001). The late mortality rate was higher in patients treated with CONS (4.9% vs 2.1% in OPEN and 1.4% in EV; P = .04).

CONCLUSIONS

EV of SAA has better short-term results compared with OPEN, including significantly lower perioperative mortality. OPEN is associated with fewer late complications and fewer reinterventions during follow-up. Patients treated with CONS showed a higher late mortality rate. Ruptured SAAs are predictors of a significantly higher perioperative mortality compared with nonruptured SAAs in the OPEN and EV groups.

Open repair, endovascular repair, and conservative management of true splenic artery aneurysms

OBJECTIVE

True splenic artery aneurysms (SAAs) are a rare but potentially fatal pathology. For many years, open repair (OPEN) and conservative management (CONS) were the treatments of choice, but throughout the last decade endovascular repair (EV) has become increasingly used. The purpose of the present study was to perform a systematic review and meta-analysis evaluating the outcomes of the three major treatment modalities (OPEN, EV, and CONS) for the management of SAAs.

METHODS

A systematic review of all studies describing the outcomes of SAAs treated with OPEN, EV, or CONS was performed using seven large medical databases. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed to ensure a high-quality review. All articles were subject to critical appraisal for relevance, validity, and availability of data regarding characteristics and outcomes. All data were systematically pooled, and meta-analyses were performed on several outcomes, including early and late mortality, complications, and number of reinterventions.

RESULTS

Original data of 1321 patients with true SAAs were identified in 47 articles. OPEN contained 511 patients (38.7%) in 31 articles, followed by 425 patients (32.2%) in CONS in 16 articles and 385 patients (29.1%) in EV in 33 articles. The CONS group had fewer symptomatic patients (9.5% vs 28.7% in OPEN and 28.8% in EV; P < .001) and fewer ruptured aneurysms (0.2% vs 18.4% in OPEN and 8.8% in EV; P < .001), but no significant differences were found in existing comorbidities. CONS patients were usually older and had smaller-sized aneurysms than patients in the OPEN and EV groups. The only identified difference in baseline characteristics between OPEN and EV was the number of ruptured aneurysms (18.4% vs 8.8%; P < .001). OPEN had a higher 30-day mortality than EV (5.1% vs 0.6%; P < .001), whereas minor complications occurred in a larger number of the EV patients. EV required more reinterventions per year (3.2%) compared with OPEN (0.5%) and CONS (1.2%; P < .001). The late mortality rate was higher in patients treated with CONS (4.9% vs 2.1% in OPEN and 1.4% in EV; P = .04).

CONCLUSIONS

EV of SAA has better short-term results compared with OPEN, including significantly lower perioperative mortality. OPEN is associated with fewer late complications and fewer reinterventions during follow-up. Patients treated with CONS showed a higher late mortality rate. Ruptured SAAs are predictors of a significantly higher perioperative mortality compared with nonruptured SAAs in the OPEN and EV groups.

African Trypanosome-Induced Blood-Brain Barrier Dysfunction under Shear Stress May Not Require ERK Activation

African trypanosomes are tsetse fly transmitted protozoan parasites responsible for human African trypanosomiasis, a disease characterized by a plethora of neurological symptoms and death. How the parasites under microvascular shear stress (SS) flow conditions in the brain cross the blood-brain barrier (BBB) is not known. In vitro studies using static models comprised of human brain microvascular endothelial cells (BMEC) show that BBB activation and crossing by trypanosomes requires the orchestration of parasite cysteine proteases and host calcium-mediated cell signaling. Here, we examine BMEC barrier function and the activation of extracellular signal-regulated kinase (ERK)1/2 and ERK5, mitogen-activated protein kinase family regulators of microvascular permeability, under static and laminar SS flow and in the context of trypanosome infection. Confluent human BMEC were cultured in electric cell-substrate impedance sensing (ECIS) and parallel-plate glass slide chambers. The human BMEC were exposed to 2 or 14 dyn/cm(2) SS in the presence or absence of trypanosomes. Real-time changes in transendothelial electrical resistance (TEER) were monitored and phosphorylation of ERK1/2 and ERK5 analyzed by immunoblot assay. After reaching confluence under static conditions human BMEC TEER was found to rapidly increase when exposed to 2 dyn/cm(2) SS, a condition that mimics SS in brain postcapillary venules. Addition of African trypanosomes caused a rapid drop in human BMEC TEER. Increasing SS to 14 dyn/cm(2), a condition mimicking SS in brain capillaries, led to a transient increase in TEER in both control and infected human BMEC. However, no differences in ERK1/2 and ERK5 activation were found under any condition tested. African trypanosomiasis alters BBB permeability under low shear conditions through an ERK1/2 and ERK5 independent pathway.

Subclavian aneurysm presenting with massive hemoptysis: a case report and review of the literature

We present a case of a 70-year-old male with a past medical history of coronary artery bypass grafting and end stage renal disease who presented with massive hemoptysis. He had a history of methicillin-resistant Staphylococcus aureus endocarditis, with infection and removal of endocardial pacing leads. His work-up revealed a 2.9-cm proximal left subclavian artery aneurysm. Bronchoscopy confirmed bright red blood in the left upper lobe bronchus and coronary angiography confirmed a patent left internal mammary artery (LIMA) to left anterior descending bypass. Because of the consideration of maintaining coronary perfusion via the LIMA while excluding the subclavian aneurysm, he underwent a left carotid to left axillary artery bypass graft followed by deployment of an Amplatzer II vascular plug just distal to the aneurysm. A thoracic endograft was then deployed to exclude the origin of the subclavian. A review of the literature reveals hemoptysis as a rare presentation of a subclavian aneurysm. We discuss approaches to this challenging clinical problem, ranging from open repair to hybrid approaches.

New modalities in the chronic ischemic diabetic foot management

The diabetic population is increasing worldwide at a staggering rate. Diabetic foot ulcers are a major contributor to nontraumatic lower limb amputations and peripheral arterial disease is one of main contributing pathophysiologic causes of diabetic ulcers. The dire need to reduce complication and wound healing recovery period of the chronic ischemic diabetic foot (CIDF) is indispensable to limb salvage and improvement of quality of life of patients with CIDF. This article discusses newer modalities that have been proposed to improve CIDF efficiently, safely, and effectively either alone or as adjuvants to conventional therapy.

Diabetes mellitus and peripheral vascular disease: diagnosis and management

Diabetes mellitus and peripheral artery disease are prevalent diseases throughout the world and often present simultaneously in the same patient, which has direct implications for their diagnosis and management. Refinements of existing and development of new diagnostic and treatment modalities are changing the management of these diseases. This article reviews the significant pathologic basis, history, and physical examination findings with respect to each disease and their presentation together. Advantages and disadvantages of different diagnostic modalities, including noninvasive studies and imaging technologies, are discussed. General medical management principles and indications, techniques, and efficacy of surgical and endovascular interventions are reviewed.

Prosthetic options available for the diabetic lower limb amputee

Although the rate of lower limb amputation in patients with diabetes is decreasing, amputation still remains a major complication of diabetes. Prosthetics have been long used to help amputees ambulate. The last decade has seen many advances in prostheses with the enhanced understanding of the mechanics of ambulation and improved use of technology. This review describes the different types of prosthetic options available for below knee, ankle, and foot amputees, emphasizing the latest advances in prosthetic design.