Diabetes and peripheral vascular disease

Outcomes and predictors of amputation-free survival in patients undergoing below-knee popliteal-distal bypass

OBJECTIVE

The infrageniculate popliteal artery is a potential source for inflow in lower extremity bypass surgery in patients with isolated tibial artery disease. The objective of our study was to assess the short- and long-term outcomes of popliteal-distal bypasses using data from the Vascular Quality Initiative (VQI).

METHODS

The VQI registry was queried between 2003 and 2021 for patients undergoing surgical revascularizations with the below-knee popliteal artery serving as inflow. Demographics, comorbidities, intraoperative characteristics, and postoperative complications were analyzed. Kaplan-Meier models were used to estimate amputation-free survival, survival, and freedom from amputation. Cox regression analysis was conducted to determine factors associated with major amputation or death.

RESULTS

A total of 1884 procedures were analyzed. The mean age of the included patients was 67.7 years. The most frequently observed preoperative comorbidities included insulin-dependent diabetes (52.3%), coronary disease (32.4%), and end-stage renal disease (14.4%). Of all the patients, 670 (35.6%) had a history of ipsilateral endovascular intervention. The procedures were performed for a variety of indications, including tissue loss (84.3%), rest pain (10.9%), and claudication (4.8%). Intraoperatively, the outflow targets were the dorsalis pedis (31.4%), the posterior tibial (24.4%), and the anterior tibial arteries (15.6%). Vein conduit was used in 92.1% of cases. The rate of perioperative myocardial infarction (MI) was 2.4%, and the 30-day mortality was 1.9%. The median length of follow up was 371 days. Amputation-free survival was found to be 85.6% (95% confidence interval [CI], 84.0%-87.2%) at 6 months and 78.6% (95% CI, 76.6%-80.4%) at 12 months. Survival was found to be 93.4% (95% CI, 92.2%-94.5%) at 6 months and 88.6% (95% CI, 87.1%-90.0%) at 12 months. Freedom from amputation was found to be 92.0% (95% CI, 90.7%-93.3%) at 6 months and 89.0% (95% CI, 87.3%-90.4%) at 12 months. Cox regression analysis demonstrated that age greater than 65 years, congestive heart failure, coronary artery disease, and end-stage renal disease were associated with a higher risk of major amputation or death (P < .05).

CONCLUSIONS

Below-knee popliteal-distal bypass is a safe and effective approach to treat severe tibial vessel occlusive disease in this challenging patient cohort. Patients exhibited low perioperative complication rates and good amputation-free survival at 1 year.

Evaluation of Cerebral Vasomotor Reactivity by Transcranial Doppler Ultrasound in Patients with Diabetic Retinopathy

The aim of this study was to assess the correlation between cerebral vasomotor reactivity (CVR) and the grade of diabetic retinopathy. A total of 43 diabetic patients with matched severity of diabetic retinopathy between their right and left eyes were included in this study. Diabetic retinopathy was graded in three groups. Right and left middle cerebral artery CVR was assessed by the breath-holding index (BHI) using transcranial Doppler ultrasound (TCD). The mean age of the patients was 56.51 ± 9.34 years with a mean duration of having diabetes mellitus of 14.49 ± 8.06 years. Diabetic retinopathy was graded as mild, moderately severe, and severe in 27.9%, 34.9%, and 37.2% of the patients, respectively. The grade of diabetic retinopathy was associated with the HbA1c level (p < .049), microalbuminuria (p < .024), and BHI (p = .001). In patients with severe diabetic retinopathy, the right-sided BHI was significantly lower as compared to those with mild or moderately severe retinopathy (p = .001 and p = .008, respectively). The left-sided BHI value in patients with severe diabetic retinopathy was significantly lower as compared to those with mild or moderately severe retinopathy (p = .001 and p = .012, respectively). In subjects with moderately severe diabetic retinopathy, both-sided BHI was significantly reduced compared to those with mild retinopathy (p = .001). Our results indicate that the grade of diabetic retinopathy was associated with impaired CVR.

Protective Effects of Ferulic Acid on Metabolic Syndrome: A Comprehensive Review

Metabolic syndrome (MetS) is a complex disease in which protein, fat, carbohydrates and other substances are metabolized in a disorderly way. Ferulic acid (FA) is a phenolic acid found in many vegetables, fruits, cereals and Chinese herbs that has a strong effect on ameliorating MetS. However, no review has summarized the mechanisms of FA in treating MetS. This review collected articles related to the effects of FA on ameliorating the common symptoms of MetS, such as diabetes, hyperlipidemia, hypertension and obesity, from different sources involving Web of Science, PubMed and Google Scholar, etc. This review summarizes the potential mechanisms of FA in improving various metabolic disorders according to the collected articles. FA ameliorates diabetes via the inhibition of the expressions of PEPCK, G6Pase and GP, the upregulation of the expressions of GK and GS, and the activation of the PI3K/Akt/GLUT4 signaling pathway. The decrease of blood pressure is related to the endothelial function of the aortas and RAAS. The improvement of the lipid spectrum is mediated via the suppression of the HMG-Co A reductase, by promoting the ACSL1 expression and by the regulation of the factors associated with lipid metabolism. Furthermore, FA inhibits obesity by upregulating the MEK/ERK pathway, the MAPK pathway and the AMPK signaling pathway and by inhibiting SREBP-1 expression. This review can be helpful for the development of FA as an appreciable agent for MetS treatment.

Carboxymethyl chitosan-alginate hydrogel containing GSNO with the ability to nitric oxide release for diabetic wound healing

Today, despite significant progress in developing skin tissue engineering products, the fabrication of an ideal wound dressing that could meet the essential criteria, such as promoting angiogenesis -mainly in a diabetic wound- still remains a challenge. A diabetic wound is a chronic wound in which vascularization is low, and the wound healing process may stop. In this regard, Nitric oxide (NO) enhances the healing of diabetic wounds by promoting angiogenesis and providing antibacterial activity in wound sites. In this study, we produced a NO-releasing wound dressing (CMC-ALg-GSNO) composed of Carboxymethyl chitosan (CMC), sodium alginate (ALg), and Snitrosoglutathione (GSNO). The results obtained from the scanning electron microscopy (SEM) show that wound dressing has a porous structure. The water uptake and water vapor transmission for the wound dressing were obtained 4354.1 ± 179.3 % and 2753.8 ± 54.6 g/m2 per day, respectively. NO release study showed that NO release from CMC-ALg-GSNO continuously occurred within 168 hours. In vivo test, The CMC-ALg-GSNO wound dressing developed wound healing in a rat model of full-thickness diabetic wounds compared to the CMC-ALg and Gauze wound dressings. Thus, this study showed that CMC-ALg-GSNO wound dressing could lead to novel therapeutic invasions to treat diabetic wounds.

Racial and ethnic amputation level disparities in veterans undergoing incident dysvascular lower extremity amputation

BACKGROUND

The choice of incident amputation level can have a profound effect on clinical outcomes. Amputations at the transmetatarsal (TM) or transtibial (TT) levels result in greater preservation of function and mobility, whereas transfemoral (TF) amputations typically result in a greater adverse impact. Prior investigations have explored racial/ethnic and regional variation in incident amputation level. This study overcomes some of the methodological limitations seen in prior research through the use of a large national, multiyear veteran sample and by including only those who have undergone an incident amputation.

OBJECTIVES

(1) Determine if there are national/regional differences in the frequency of incident TF amputation compared with TM and TT amputation, (2) Determine if race/ethnicity and geographic region are associated with incident TF amputation level, and (3) Determine if racial/ethnic disparities of incident TF amputation differ by the presence of diabetes or prior revascularization.

DESIGN

Retrospective cohort study of veterans undergoing an incident dysvascular lower extremity amputation.

SETTING

One hundred ten Veterans Affairs (VA) Medical Centers.

PARTICIPANTS

Seven thousand two hundred ninety-six Veterans undergoing incident unilateral dysvascular lower extremity amputation identified in the Veterans Affairs Surgical Quality Improvement Program (VASQIP) database (2005-2014).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE

Incident amputation level.

RESULTS

The White, Black, and Hispanic risk for an incident TF amputation was 31% (n = 1356), 35% (n = 810), and 46% (n = 293), respectively. In the Continental region, Blacks who had not had a prior revascularization were more likely to undergo a TF amputation compared to Whites both with and without diabetes (odds ratio [OR] = 1.4; 95% confidence interval [CI], 1.1, 1.9 and OR = 1.5; 95% CI, 1.1, 2.1, respectively). In the Southeast region, Hispanics compared with Whites were at increased odds of undergoing a TF amputation, irrespective of a diabetes or a prior revascularization (ORs ≥ 2.9).

CONCLUSIONS

Racial and ethnic disparities exist in choice of proximal compared with distal amputation in specific VA geographic regions.

Lactobacillus gasseri liver abscess and bacteremia: a case report

BACKGROUND

Lactobacillus is a genus of Gram-positive non-spore-forming rods usually found in the microbiota of the oral cavity, gastrointestinal tract, and female genitourinary tract. Also, they are commonly used in the food industry as supplements and probiotics. Lactobacilli are normally considered non-pathogenic to the human body, however, under certain circumstances such as immunosuppression, they can cause severe infections, with only a few cases of bacteremia, infective endocarditis, pneumonia, meningitis, and intra-abdominal infections reported. Among these presentations, a pyogenic liver abscess is rather rare.

CASE PRESENTATION

We describe the case of a 59-year-old man with a history of diabetes mellitus and multiple abdominal surgeries with the latest being in 2014 presenting with bacteremia and multiple large pyogenic liver abscesses due to Lactobacillus gasseri, which did not appear to be related to the use of probiotics or immunosuppression.

CONCLUSIONS

Given the high prevalence of diabetes mellitus and the increased use of probiotics, it is expected that in the future we will see an increase in infections caused by Lactobacilli. Medical management with antibiotics and percutaneous drainage were successful strategies for the treatment of this unusual case of pyogenic liver abscesses and bacteremia caused by Lactobacillus gasseri.

The Functionality of Endothelial-Colony-Forming Cells from Patients with Diabetes Mellitus

Endothelial-colony-forming cells (ECFCs) are a population of progenitor cells which have demonstrated promising angiogenic potential both in vitro and in vivo. However, ECFCs from diabetic patients have been shown to be dysfunctional compared to ECFCs from healthy donors. Diabetes mellitus itself presents with many vascular co-morbidities and it has been hypothesized that ECFCs may be a potential cell therapy option to promote revascularisation in these disorders. While an allogeneic cell therapy approach would offer the potential of an ‘off the shelf’ therapeutic product, to date little research has been carried out on umbilical cord-ECFCs in diabetic models. Alternatively, autologous cell therapy using peripheral blood-ECFCs allows the development of a personalised therapeutic approach to medicine; however, autologous diabetic ECFCs are dysfunctional and need to be repaired so they can effectively treat diabetic co-morbidities. Many different groups have modified autologous diabetic ECFCs to improve their function using a variety of methods including pre-treatment with different factors or with genetic modification. While the in vitro and in vivo data from the literature is promising, no ECFC therapy has proceeded to clinical trials to date, indicating that more research is needed for a potential ECFC therapy in the future to treat diabetic complications.

Regular Use of FlowAid FA100 SCCD Reduces Pain While Increasing Perfusion and Tissue Oxygenation in Contralateral Limbs of Amputees With Diabetic Neuropathy and Peripheral Arterial Disease: Results of an Open, Pre-Post Intervention, Single-Center Study

Patients with diabetic neuropathy and peripheral arterial disease often suffer pain, develop foot wounds, and go on to lose limbs leaving them with a painful limb. Electrical stimulation is one possibility open to physicians. In this study, the effects of the FlowAid FA100 SCCD, a sequential contraction compression device, were tested. The FA100 device is noninvasive; it uses 4 electrodes to sequentially stimulate the calf muscles in a modified intermittent pneumatic compression manner. A total of 14 patients with diabetic neuropathy, peripheral arterial disease, unilateral amputation, and a painful limb were treated with FlowAid FA100 (FlowAid Medical Technologies Corporation, New York, NY) with prior ethical approval. The study design was open, pre-post intervention comparison, and nonrandomized. Pain perceived was measured using Visual Analogue Scale (VAS) scores. Assessments of ankle brachial index (ABI), ultrasound color Duplex, and tissue oxygen using the transcutaneous oxygen technique were done at baseline and 2 successive follow-ups 4 weeks apart. Three out of 14 patients dropped out on account of distances involved in traveling to the clinic. Eleven out of 14 patients experienced statistically significant reduction in pain mean VAS scores (7.5 ± 0.93 to 5.8 ± 1.47, P = .002) associated with increase in ABI (0.64 ± 0.06 to 0.69 ± 0.04, P < .001) and transcutaneous oxygen tension measured on the dorsum (29.4 ± 4.03 to 33.2 ± 5.26 in mm Hg, P = .005). When pain scores were regressed against ABI and transcutaneous oxygen tension values, there was a significant association between these (r = 0.8, P = .002). The reduction in pain following regular use of FlowAid was accompanied by beneficial and statistically significant increases in perfusion and oxygenation.

Vein Harvest Wound Healing after Bypass Surgery for Critical Limb Ischemia

BACKGROUND

Lower-limb revascularization surgery, especially when performed using the great saphenous vein, predisposes patients to major surgical trauma on initially ischemic tissue. Vein harvest wounds (VHWs) after infrainguinal revascularization heal slowly. This study's aim was to assess the factors associated with VHW healing after infrainquinal bypass surgery for critical limb ischemia (CLI).

METHODS

A retrospective patient record study was conducted. All patients with CLI who underwent infrainguinal bypass surgery with autologous vein graft between January 1, 2015, and December 31, 2017, in the Turku University Hospital, were included. Follow-up data were collected until February 28, 2018. The following data was collected from the patient files; risk factors, ankle-brachial indices (ABIs), systolic toe pressures (STPs), the presence of an ischemic ulcer, VHW dehiscence, and the time when the VHW was completely healed. Procedures with outflow vessels at either popliteal or tibial artery were analyzed separately. Descriptive and univariate statistical analyses were performed.

RESULTS

Altogether, 195 patients were operated on for CLI, of whom 133 (68.2%) patients had ischemic ulcers. The mean follow-up time was 535.0 days (range 3.0-1143.0 days). The mean ABI improvement was 0.49 (P = 0.00), and STP improvement, 39.9 mm Hg (P = 0.00). The median time taken when VHW was healed was 48.0 days (95% confidence interval [CI], 39.4-56.6) in patients without ischemic ulcers and 82.0 days (95% CI, 59.7-104.3) in patients with ischemic ulcers, P = 0.03. VHW in patients who underwent popliteal artery bypass (62 days, 95% CI, 12.9-93.0) healed faster than VHW in those who underwent tibial artery bypass (132 days, 95% CI, 48.0-93.0), P = 0.02. Risk factors and the preoperative or postoperative ABIs or STPs had no effect on VHW healing time.

CONCLUSIONS

VHW healing was remarkably slower after revascularization surgery in patients with an ischemic foot ulcer than in those without ischemic ulcers.

Relationship between skin temperature and soft tissue hardness in diabetic patients: an exploratory study

OBJECTIVE

The role of skin temperature and soft tissue hardness in the development of plantar ulcers is still in debate. However, the relationship between skin temperature and soft tissue hardness has not been explored. This study intends to analyse an eventual association between skin temperature and soft tissue hardness in the foot of diabetic patients Approach: Twenty diabetic patients enrolled for this study. The analysis was done at the foot level, therefore, skin temperature and soft tissue hardness data of the plantar surface of 40 feet were obtained in eight regions of the foot, two in the heel, two in the midfoot, three in the forefoot and one in the hallux. Information regarding glycaemic control (HbA1c levels) was retrieved from the clinical records of the patients.

MAIN RESULTS

After averaging skin temperature and soft tissue hardness in the calcaneum (medial and lateral), in the midfoot (medial and lateral) and in the metatarsal head (1st, 2nd-3rd and 4th-5th), a negative, moderate and significant association was found between skin temperature and soft tissue hardness in the metatarsal head (rho  =  -0.553; p   <  0.001), a positive, low and significant association was found in the midfoot (rho  =  0.333; p   =  0.036), but no association was found in the heel. The multiple linear regression models with skin temperature as dependent variable and soft tissue hardness as predictor were statistically significant in the metatarsal heads and midfoot, and explained 28.8% (R ²  =  0.288, F _(1,38)  =  15.37, p   <  0.001) and 11.9% (R ²  =  0.119, F _(1,38)  =  5.151, p   =  0.029) of the variance in skin temperature, respectively.

SIGNIFICANCE

Skin temperature is negatively associated with soft tissue hardness in the metatarsal head region and positively associated with soft tissue hardness in the midfoot. These findings imply that soft tissue hardness should be considered in the assessment of diabetic foot patients and that this variable should be controlled in studies assessing the determinants of foot skin temperature.

Breaking Bad: a case of Lactobacillus bacteremia and liver abscess

We present a case of a 46-year-old Hispanic male with a past medical history significant for uncontrolled diabetes presenting with abdominal pain, nausea and vomiting and found to have Lactobacillus bacteremia and liver abscess. A PubMed and Clinical Key literature review of the other known cases of Lactobacillus liver abscess was performed. Through examination of previous case reports, the patient presented in this paper, and the associated risk factors of Lactobacillus liver abscess it is likely that the incidence of this rare condition will increase and would therefore be prudent to further study Lactobacillus as a pathogenic bacteria so that its complications may be better treated and prevented.

The diabetic foot: Pathophysiology, evaluation, and treatment

The pathophysiology of the diabetic foot ulcer and soft-tissue infection is due to neuropathy, trauma, and, in many patients, concomitant peripheral artery occlusive disease. Diabetic neuropathy results in foot deformity, leading to increased skin pressure with walking. Once a foot ulcer develops, the limb is at high risk for invasive infection and, when combined with peripheral artery occlusive disease, the patient should be considered to have critical limb ischemia. A multidisciplinary approach to care for the diabetic foot is recommended, which includes annual (3-month intervals in high-risk patients) assessments by a primary care physician and referral to a podiatrist and vascular surgeon for diabetics with a foot ulcer for evaluation of foot arterial perfusion and off-loading therapy to reduce plantar skin pressure with walking. When invasive foot infection develops and tissue beneath the fascia is involved, inpatient care is recommended for systemic antibiotic therapy, vascular laboratory testing of artery limb perfusion, and surgical debridement of infected tissue. The goals of treatment are to achieve a healed foot and keep the patient ambulatory.

Rev-erbα activation down-regulates hepatic Pck1 enzyme to lower plasma glucose in mice

REV-ERBα (NR1D1) is a nuclear heme receptor that controls many cellular processes including cell differentiation, lipid metabolism, and inflammatory responses. Although REV-ERBα has been also implicated in regulation of glucose homeostasis, the mechanism for this regulation remains unclear. Here we investigate a potential role of REV-ERBα in regulation of PCK1 (phosphoenolpyruvate carboxykinase 1), a rate-limiting enzyme in gluconeogenesis. Hepatoma cells (Hepa-1c1c7 and HepG2 cells), wild-type mice and streptozotocin-induced diabetic mice were treated with SR9009, a specific REV-ERBα agonist. The relative mRNA and protein levels of enzymes in the cells or mouse livers were determined by qPCR and Western blotting, respectively. The fasting plasma glucose test was performed to determine the effects of Rev-erbα on glucose homeostasis. Transcriptional regulation of Pck1 by Rev-erbα was investigated using a combination of luciferase reporter, mobility shift, and chromatin immunoprecipitation (ChIP) assays. SR9009 treatment significantly decreased the mRNA level of Pck1 in mouse hepatoma Hepa-1c1c7 cells, whereas other major enzymes involved in gluconeogenesis (pyruvate carboxylase, glucose-6-phosphatase, fructose bisphosphatase and Pck2) and in glycolysis (phosphofructokinase and hexokinase-1) were unaffected. Consistent with the mRNA change, the protein level of Pck1 was down-regulated. Similarly, a repressive action of REV-ERBα on PCK1 expression was observed in human HepG2 hepatoma cells. SR9009 administration to wild-type or diabetic mice significantly reduced the level of fasting plasma glucose. This coincided with decreased mRNA and protein levels of Pck1 in the liver. In addition, the diabetic mice showed an improvement in glucose tolerability after SR9009 treatment. Promoter analysis, mobility shift, and ChIP assays revealed that Rev-erbα trans-repressed Pck1 through direct binding to -325 to -320 bp region (a RevRE site) in the gene promoter. In conclusion, Rev-erbα activation down-regulates hepatic Pck1 to lower plasma glucose.

Countermeasures against Infection in Critical Limb Ischemia Treatments

The preoperative and postoperative infection control measures for critical limb ischemia treatments were described. The treatment strategies for severe ischemic limbs were showed according to the presence and extent of infection. If the treatment strategy for a severe ischemic limb with infection is mistaken, infection will spread and make worse the situation of the ischemic limb, and eventually it can result not only in limb loss but also life threatening. A surgical strategy is very important in the bypass material, the selection of anastomotic site, the use of postoperative antibacterial drugs, and the wound treatment. Infection troubles are the most familiar and indispensable problem for surgeons, the countermeasures against infection especially in critical limb ischemia is the key point along with revascularization. (This is a translation of Jpn J Vasc Surg 2018; 27: 129–132.)

Blood flow characteristics of diabetic patients with complications detected by optical measurement

Background

Diabetes mellitus (DM) is one of the most common diseases worldwide. Uncontrolled and prolonged hyperglycemia can cause diabetic complications, which reduce the quality of life of patients. Diabetic complications are common in DM patients. Because it is impossible to completely recover from diabetic complications, it is important for early detection. In this study, we suggest a novel method of determining blood flow characteristics based on fluorescence image analysis with indocyanine green and report that diabetic complications have unique blood flow characteristics.

Methods

We analyzed time-series fluorescence images obtained from controls, DM patients, and DM patients with complications. The images were segmented into the digits and the dorsum of the feet and hands, and each part has been considered as arterial and capillary flow. We compared the blood flow parameters in each region among the three groups.

Results

The DM patients with complications showed similar blood flow parameters to the controls, except the area under the curve and the maximum intensity, which indicate the blood flow volume. These parameters were significantly decreased in DM patients with complications. Although some blood flow parameters in the feet of DM patients with complications were close to normal blood flow, the vascular response of the macrovessels and microvessels to stimulation of the hands was significantly reduced, which indicates less reactivity in DM patients with complications.

Conclusions

Our results suggest that DM patients, and DM patients with complications, have unique peripheral blood flow characteristics.

The Difference Between the Healing and the Nonhealing Diabetic Foot Ulcer: A Review of the Role of the Microcirculation

BACKGROUND

Diabetic foot disease carries a high morbidity and is a leading cause of lower limb amputation. This may in part be due to the effect diabetes mellitus (DM) has on the microcirculation including in the skin.

METHOD

We conducted a review of studies that have examined the relationship between microcirculatory function and wound healing in patients with DM. A search of the Medline, Embase, and Web of Science databases was performed coupled with a review of references for the period 1946 to March 2015.

RESULTS

Nineteen studies of diverse methodology and cohort selection were identified. Poor function of the microcirculation was related to poor outcome. Transcutaneous oxygen pressure (TcPO₂) was the most commonly used method to measure the microcirculation and thresholds for poor outcome proposed ranged from 10 mmHg to <34 mmHg. Two studies reexamined microcirculatory function following revascularization. Both found an increase in TcPO₂, however only 1 reached statistical significance. No significant difference in the results of microcirculation tests was found between diabetic and nondiabetic patients.

CONCLUSIONS

While it is not possible to draw firm conclusions from the evidence currently available there are clear areas that warrant research. Good microcirculation unsurprisingly appears to associate with better wound healing. The influence of DM is not clear, and neither is the degree of improvement required to achieve healing. Studies that examine a clearly defined cohort both with and without DM are urgently required. Accurate quantitative assessment of microcirculation will aid prediction of wound healing identifying those at greatest risk of amputation.

A nationwide analysis of 30-day readmissions related to critical limb ischemia

Objectives There is paucity of information regarding critical limb ischemia-related readmission rates in patients admitted with critical limb ischemia. We studied 30-day critical limb ischemia-related readmission rate, its predictors, and clinical outcomes using a nationwide real-world dataset. Methods We did a secondary analysis of the 2013 Nationwide Readmissions Database. We included all patients with a primary diagnosis of extremity rest pain, ulceration, and gangrene secondary to peripheral arterial disease. From this group, all patients readmitted with similar diagnosis within 30 days were recorded. Results Of the total 25,111 index hospitalization for critical limb ischemia, 1270 (5%) were readmitted with a primary diagnosis of critical limb ischemia within 30 days. The readmission rate was highest (9.5%) for the group that did not have any intervention (revascularization or major amputation) and was lowest for surgical revascularization and major amputation groups (2.6% and 1.3%, P value <0.001 for all groups). Severity of critical limb ischemia at index admission was associated with a significantly higher rate of 30-day readmission. Critical limb ischemia-related readmission was associated with a higher rate of major amputation (29.6% vs. 16.2%, P<0.001), a lower rate of any revascularization procedure (46% vs. 62.6%, P<0.001), and a higher likelihood of discharge to a skilled nursing facility (43.2% vs. 32.2%, P<0.001) compared to index hospitalization. Conclusions In patients with primary diagnosis of critical limb ischemia, 30-day critical limb ischemia-related readmission rate was affected by initial management strategy and the severity of critical limb ischemia. Readmission was associated with a significantly higher rate of amputation, increased length of stay, and a more frequent discharge to an alternate care facility than index admission and thus may serve as a useful quality of care metric in critical limb ischemia patients.

Control of lower extremity edema in patients with diabetes: Double blind randomized controlled trial assessing the efficacy of mild compression diabetic socks

AIMS

Persons with diabetes frequently present with lower extremity (LE) edema; however, compression therapy is generally avoided for fear of compromising arterial circulation in a population with a high prevalence of peripheral arterial disease. This double blind randomized controlled trial (RCT) assessed whether diabetic socks with mild compression could reduce LE edema in patients with diabetes without negatively impacting vascularity.

METHODS

Eighty subjects with LE edema and diabetes were randomized to receive either mild-compression knee high diabetic socks (18-25mmHg) or non-compression knee high diabetic socks. Subjects were instructed to wear the socks during all waking hours. Follow-up visits occurred weekly for four consecutive weeks. Edema was quantified through midfoot, ankle, and calf circumferences and cutaneous fluid measurements. Vascular status was tracked via ankle brachial index (ABI), toe brachial index (TBI), and skin perfusion pressure (SPP).

RESULTS

Seventy-seven subjects (39 controls and 38 mild-compression subjects) successfully completed the study. No statistical differences between the two groups in terms of age, body mass index, gender, and ethnicity. Repeated measures analysis of variance and Sidak corrections for multiple comparisons were used for data analyses. Subjects randomized to mild-compression diabetic socks demonstrated significant decreases in calf and ankle circumferences at the end of treatment as compared to baseline. LE circulation did not diminish throughout the study with no significant decreases in ABI, TBI or SPP for either group.

CONCLUSIONS

Results of this RCT suggest that mild compression diabetic socks may be effectively and safely used in patients with diabetes and LE edema.

Measuring reactive hyperemia in the lower limb using near-infrared spectroscopy

Near-infrared spectroscopy (NIRS) has been used to measure reactive hyperemia following a vascular occlusion. However, the procedures and methods of analysis used have varied. The purpose of the present study is to identify reproducible methods for measuring reactive hyperemia using HbO2 NIRS signals in the calf and foot. Healthy participants (10 male, 10 female) aged 19 to 28 years performed one of two tests: reproducibility trials or elevation protocol (30 and 60 cm limb elevation above the heart). The time to 50% reperfusion (T1/2) and the second (R2q) quartile rates of reperfusion were found to be the most reproducible parameters (coefficient of variation= 7.12 to 14.1%). The time to 95% reperfusion (T95) was 12.7% more reproducible on average than the previously reported parameter of time to peak hyperemia. Measures of reperfusion time and rate slowed with increasing limb elevation. Correlations were identified between the calf and foot in the measurements of R2q (R2 = 0.713, p = 0.021), T1/2 (R2 = 0.673, p = 0.033), and T95 (R2 = 0.792, p = 0.006). Half and 95% recovery times and second and third quartile rates expressed good reproducibility and sensitivity to change with reduced perfusion pressure. NIRS measures of reactive hyperemia have the potential to evaluate microvascular perfusion in clinical populations.

The Protective Effect of Antioxidants Consumption on Diabetes and Vascular Complications

Obesity and diabetes is generally accompanied by a chronic state of oxidative stress, disequilibrium in the redox balance, implicated in the development and progression of complications such as micro- and macro-angiopathies. Disorders in the inner layer of blood vessels, the endothelium, play an early and critical role in the development of these complications. Blunted endothelium-dependent relaxation and/or contractions are quietly associated to oxidative stress. Thus, preserving endothelial function and oxidative stress seems to be an optimization strategy in the prevention of vascular complications associated with diabetes. Diet is a major lifestyle factor that can greatly influence the incidence and the progression of type 2 diabetes and cardiovascular complications. The notion that foods not only provide basic nutrition but can also prevent diseases and ensure good health and longevity is now attained greater prominence. Some dietary and lifestyle modifications associated to antioxidative supply could be an effective prophylactic means to fight against oxidative stress in diabesity and complications. A significant benefit of phytochemicals (polyphenols in wine, grape, teas), vitamins (ascorbate, tocopherol), minerals (selenium, magnesium), and fruits and vegetables in foods is thought to be capable of scavenging free radicals, lowering the incidence of chronic diseases. In this review, we discuss the role of oxidative stress in diabetes and complications, highlight the endothelial dysfunction, and examine the impact of antioxidant foods, plants, fruits, and vegetables, currently used medication with antioxidant properties, in relation to the development and progression of diabetes and cardiovascular complications.

Ferulic acid, a natural polyphenol, alleviates insulin resistance and hypertension in fructose fed rats: Effect on endothelial-dependent relaxation

Ferulic acid (FER) is a polyphenolic compound contained in various types of fruits. It has a substantial therapeutic effect inhibitory activity against aldose reductase (AR) inhibition. In this study, we examined the effect of FER on fructose-fed rats in comparison to a standard AR inhibitor, zopolrestat (ZOP). We determined the protective role of FER against metabolic syndrome by examining serum insulin/Glucose levels, triglycerides (TGs), cholesterol and advanced glycation end product (AGE) in rats supplied with 10% fructose drinking water. In addition, blood pressure, vascular reactivity of isolated thoracic aortas and acetylcholine-induced NO were all evaluated to estimate the cardiovascular complications of metabolic syndrome (MetS) associated with fructose feeding. Animals were randomly divided into four groups: control, (+10% fructose, Fru), zopolrestat-treated fructose fed (Fru-zop) and ferulic acid-treated fructose fed rats (Fru-Fer). After 12 weeks of FER treatment, we found significant reduction in both hyperinsulinemia and elevated diastolic blood pressure associated with fructose-fed to levels comparable to those achieved with ZOP. Both FER and ZOP significantly augmented the impaired relaxation associated with fructose-fed, whereas neither showed any significant effect on the developed vasoconstriction. Isolated aortas from fructose-fed rats incubated with either FER or ZOP, reinstated normal relaxation response to acetylcholine (ACh). Furthermore, isolated aortas showed attenuated nitric oxide (NO) production following the addition of (ACh), while both FER and ZOP restored normal induction of NO. Taken together, the current study shows that, FER alleviated insulin resistance and hypertension associated with metabolic syndrome compared to the standard AR inhibitor (ZOP). This potential protective effect is at least mediated by restoring endothelial relaxation.

A Novel and Alternative Treatment Method for Diabetic Heel Ulceration Exposing the Calcaneus Which Is Not Suitable for Flap Surgery: Vacuum Assisted Sandwich Dermal Matrix

Background. Currently, free flaps and pedicled flaps are the first treatment choices for large heel ulcer reconstruction. However, flap reconstruction of heel ulcerations cannot be performed in all diabetics especially with concurrent severe peripheral vascular disease because of higher flap failure rate. In recent years, the use of acellular dermal matrix (ADM) has emerged as an alternative treatment option for extremity ulcers. Methods. We present 13 diabetic patients with a large heel ulceration exposing the calcaneus, who were not eligible for flap surgery due to the presence of only one patent artery of trifurcation. These cases were treated with the vacuum assisted sandwich dermal matrix (VASDEM) method. Results. None of the patients required amputation. Skin grafting was successful in ten patients. Although partial losses were observed in three patients, they were healed spontaneously without surgical interventions. During the follow-up period none of the patients developed ulceration on the treatment area. All patients maintained their preoperative ambulatory ability. Conclusion. VASDEM is a novel method offering opportunity for treatment before proceeding to amputation in diabetic heel ulceration exposing the calcaneus which is not suitable for flap surgery. It also has the potential to close wounds of all sizes independent of the vessel status and wound size in selected diabetic patients.

Diagnoses and clinical features associated with high risk for unplanned readmission in vascular surgery. A cohort study

Background

Readmission rate is an established health quality indicator. Preventable readmissions bear an unnecessary, high cost on the healthcare system. An analysis performed by the National Centre for Health Outcomes Development (NCHOD) has demonstrated an increasing trend in emergency readmissions in the UK. Vascular surgery has been reported to have high readmission rates second only to congestive heart failure. This study aims to identify diagnoses and other clinical risk factors for high unplanned readmission rates. This may be the first step to sparing both the health care system and patients of unnecessary readmissions.

Results

The overall 30 day readmission rate for Leeds Vascular Institute was 8.8%. The two diagnoses with the highest readmission rates were lower limb ischaemia and diabetic foot sepsis. The readmission rate for medical reasons was overwhelmingly higher than for surgical reasons (6.5% and 2.3% respectively). The most common medical diagnoses were renal disease and COPD. The majority of the patients readmitted under the care of vascular surgery required further surgical treatment.

Conclusion

Vascular units should focus on holistic and multidisciplinary treatment of lower limb ischaemia and diabetic foot sepsis, in order to prevent readmissions. Furthermore, the early involvement and input of physicians in the treatment of vascular patients with renal disease and COPD may be appropriate.

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Lower limb ischaemia and diabetic foot sepsis are the two diagnoses with the highest readmission rate.

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Vascular patients are more frequently readmitted for medical rather than surgical health problems.

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For vascular patients, the most common medical, readmission diagnoses are infection renal disease complications and COPD exacerbation.

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Most of the patients readmitted under vascular surgery necessitate further surgical treatment.

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Diabetes may be an independent risk factor for readmission.

Management of critical lower limb ischemia in endovascular era: experience from 511 patients

This study aims at the assessment of the achievability of the endovascular treatment of patients with critical limb ischemia (CLI) and the role of bypass in such patient. This is a prospective study conducted on patients with chronic atherosclerotic critical lower limb ischemia presenting to us over a period of 3 years. Patients presenting with nonsalvageable limbs requiring primary major amputation and nonatherosclerotic causes of CLI were excluded. Endovascular treatment was the first choice modality of treatment in revascularization of all patients. Open surgery was offered selectively for patient whom endovascular failed or complicated and for long TransAtlantic Inter-Society Consensus (TASC) II lesions in fit patients. This study included 511 cases of CLI, and the mean age was 64.5 years. Patients with Rutherford IV, V, and VI were 19.25, 60.5, and 19.25%, respectively. The TASC II aortoiliac lesions were as follows: A, B, C, and D in 33.7, 12,15.7, and 38.6%, respectively, and infrainguinal lesions were A, B, C, and D in 3.7, 19, 35.4, and 68.3%, respectively. A total of 78.3% of patients were treated by endovascular totally, while 16% were treated by surgery from the start, 3.7% of endovascular cases were converted to open surgery after failure of endovascular treatment, and 2% was offered hybrid treatment. Crossing of lesions by subintimal and intraluminal was 12.5 and 87.5%, respectively. Technical success in endovascular was 94%; however, we could successfully revascularize 96.8% of all CLI presented in this study by either surgery or endovascular. On 24 months follow-up, primary patency, secondary patency, and limb salvage by percutaneous transluminal angioplasty are 77.8, 84.7, and 90.7%, respectively. Revascularization by endovascular achieves high technical success and limb salvage in CLI, hence should be considered as preferred choice of treatment. However, both endovascular and surgery should not be counteracting each other and using both can revascularize 96.6% of CLI.

Does PGE₁ vasodilator prevent orthopaedic implant-related infection in diabetes? Preliminary results in a mouse model

BACKGROUND

Implant-related infections are characterized by bacterial colonization and biofilm formation on the prosthesis. Diabetes represents one of the risk factors that increase the chances of prosthetic infections because of related severe peripheral vascular disease. Vasodilatation can be a therapeutic option to overcome diabetic vascular damages and increase the local blood supply. In this study, the effect of a PGE₁ vasodilator on the incidence of surgical infections in diabetic mice was investigated.

METHODOLOGY

A S. aureus implant-related infection was induced in femurs of diabetic mice, then differently treated with a third generation cephalosporin alone or associated with a PGE₁ vasodilator. Variations in mouse body weight were evaluated as index of animal welfare. The femurs were harvested after 28 days and underwent both qualitative and quantitative analysis as micro-CT, histological and microbiological analyses.

RESULTS

The analysis performed in this study demonstrated the increased host response to implant-related infection in diabetic mice treated with the combination of a PGE₁ and antibiotic. In this group, restrained signs of infections were identified by micro-CT and histological analysis. On the other hand, the diabetic mice treated with the antibiotic alone showed a severe infection and inability to successfully respond to the standard antimicrobial treatment.

CONCLUSIONS

The present study revealed interesting preliminary results in the use of a drug combination of antibiotic and vasodilator to prevent implant-related Staphylococcus aureus infections in a diabetic mouse model.

Successful foot salvage with microvascular flaps in diabetic patients

BACKGROUND AND AIMS

Complex nontraumatic foot lesions often lead to major lower-limb amputation in diabetic patients. We aimed to evaluate outcome of free flap transfer in such cases.

MATERIALS AND METHODS

A total of 11 consecutive diabetic patients, hospitalized between 2007 and 2012 at a university central hospital for a free flap transfer, were followed until September 2013. Amputation-free survival, patient survival, and complete wound healing were defined as primary endpoints. Healing time of tissue lesions was analyzed. All pre- and postoperative data were retrospectively collected from hospital charts.

RESULTS

Complete tissue healing at 6 and 12 months after free flap transfer were 55% (6/11) and 82% (9/11), respectively. The median time to complete tissue healing was 123 days (range, 45-207 days). Overall limb salvage, survival, and amputation-free survival rates at 12 months were 90%, 91%, and 82%, respectively. The clinically important endpoint, namely, amputation-free survival with completely healed wounds, was attained in 9 of 11 patients at 1 year.

CONCLUSION

Free tissue transfer enables successful wound healing and limb salvage rather than amputation in selected diabetic patients with difficult-to-heal wounds. Complete healing of tissue lesions is slow even after successful surgery. Preoperative assessment of the condition of patients is the key to success.

Peripheral arterial disease and bypass surgery in the diabetic lower limb

PAD is very common in people with diabetes and is one of the strongest predictors of developing nonhealing foot ulcers and suffering amputation. There is strong evidence to show that early detection of PAD and revascularization will reduce amputations. Despite this, many patients have no vascular assessment even when they present with a foot ulcer or before amputation. Even when identified, patients are referred late, which worsens their outcome. Currently there is no evidence to support surgical revascularization over endovascular treatments, but in reality the techniques are complementary and the choice of revascularization procedure should be determined by an experienced multidisciplinary vascular team. Surgical revascularization can achieve good results but careful patient selection, operative planning, and the use of autologous vein are necessary. What is clearly apparent is that at present not enough patients are being offered revascularization to prevent amputation.

Aldose reductase inhibitors zopolrestat and ferulic acid alleviate hypertension associated with diabetes: effect on vascular reactivity

This study investigated the effect of aldose reductase (AR) inhibitors on hypertension in diabetes. Diabetes was induced with streptozotocin, while AR inhibitors zopolrestat and ferulic acid were administered at 2 weeks after streptozotocin treatment and for 6 weeks afterwards. Then, blood pressure (BP) and serum level of glucose were determined. Concentration–response curves for phenylephrine (PE), KCl, and acetylcholine (ACh) were obtained in isolated aorta. In addition, ACh-induced NO and reactive oxygen species (ROS) generation in aorta and histopathology were examined. Compared with the control animals, diabetes increased diastolic and systolic BP. AR inhibitors reduced diastolic BP elevation without affecting the developed hyperglycaemia. Diabetes increased the contractile response of aorta to KCl, and decreased the relaxation response to Ach, while administering AR inhibitors prevented an impaired response to ACh. Incubation of aorta isolated from diabetic animals with AR inhibitors did not affect the impaired relaxation response to ACh. In addition, AR inhibitors negated the impaired Ach-stimulated NO generation seen in aorta isolated from diabetic animals. Furthermore, diabetes was accompanied with marked infiltration of leukocytes in aortic adventitia, endothelial cell pyknosis, and increased ROS formation. AR inhibitors reduced leukocyte infiltration and inhibited endothelial pyknosis and ROS formation. In conclusion, AR inhibitors negate diabetes-evoked hypertension via ameliorating impaired endothelial relaxation and NO production.

Chronic inhibition of epidermal growth factor receptor tyrosine kinase and extracellular signal-regulated kinases 1 and 2 (ERK1/2) augments vascular response to limb ischemia in type 2 diabetic mice

Type 2 diabetes is a key risk factor for ischemia-dependent pathology; therefore, a significant medical need exists to develop novel therapies that increase the formation of new vessels. We explored the therapeutic potential of epidermal growth factor receptor tyrosine kinase (EGFRtk) and extracellular signal-regulated kinase 1/2 (ERK1/2) inhibition in impaired ischemia-induced neovascularization in type 2 diabetes. Unilateral femoral artery ligation was performed in diabetic (db(-)/db(-)) and their control (db(-)/db(+)) mice for 4 weeks, followed by treatments with EGFRtk and ERK1/2 inhibitors (AG1478, 10 mg/kg/day and U0126, 400 μg/kg/day, respectively) for 3 weeks. Neovascularization, blood flow recovery, vascular and capillary density, and endothelial nitric oxide synthase activity were significantly impaired and were associated with enhanced EGFRtk and ERK1/2 activity in db(-)/db(-) mice. EGFRtk and ERK1/2 inhibitors did not have any effect in control mice, while in db(-)/db(-) mice there was a significant increase in neovascularization, blood flow recovery, vascular and capillary density, endothelial nitric oxide synthase activity, and were associated with a decrease in EGFRtk and ERK1/2 activity. Our data demonstrated that the inhibition of EGFRtk and ERK1/2 restored ischemia-induced neovascularization and blood flow recovery in type 2 diabetic mice. Thus, EGFRtk and ERK1/2 could be possible targets to protect from ischemia-induced vascular pathology in type 2 diabetes.

Cinnamaldehyde protects from the hypertension associated with diabetes

Here we investigated cinnamaldehyde (CA) effect on diabetes-induced hypertension. Insulin deficiency was induced by streptozotocin while, insulin resistance by fructose. Rats were left 8 weeks or 12 weeks after STZ or fructose administration respectively. CA (20 mg kg(-1)day(-1)) was daily administered in the last 6 weeks. Then, blood pressure (BP) was recorded. Isolated Aorta reactivity to phenylephrine (PE), KCl, acetylcholine (ACh) was studied as well as nitric oxide (NO) generation plus Ca(2+) influx. Insulin deficiency was associated with elevated BP, increased response to PE and KCl, decreased response to ACh and impaired NO generation. CA treatment prevented hyperglycemia and its associated impaired vascular reactivity. Insulin resistance was associated with elevated BP while, CA prevented this elevation. Insulin resistance increased response to PE and KCl, decreased response to ACh, while CA treatment normalized response to KCl and PE but not to ACh. Insulin resistance was accompanied with reduced NO generation but exaggerated Ca(2+) influx while CA restored normal Ca(2+) influx but did not affect NO generation. In conclusion, CA prevents development of hypertension in insulin deficiency and insulin resistance through normalization of vascular contractility in addition to its insulinotropic effect in insulin deficiency.

Low rehospitalization rate for vascular surgery patients

OBJECTIVES

Reducing rehospitalization rates has been proposed to improve care, reduce costs, and as a pay-for-performance criterion. Recent review of Medicare claims data indicates that vascular surgery patients have among the highest rates of 30-day rehospitalization at 23.9%.

METHODS

We retrospectively examined all live patient discharges (n = 799) from the vascular surgery service at a single university hospital over 12 months. Planned and unplanned 30-day rehospitalizations were distinguished, and predictors of unplanned 30-day rehospitalization were determined. To identify whether patients were readmitted to other hospitals, a prospective study of patient discharges (n = 66) over 1 month was also performed.

RESULTS

Ninety-five (11.9%) of the 799 patient discharges from the vascular surgery service were rehospitalized within 30 days. Of these, 71 were unplanned; therefore, the unplanned rehospitalization rate was 8.9%. The most common causes of unplanned 30-day rehospitalization were related to wound complications. Diabetes (P = .039) predicted unplanned 30-day rehospitalization by multivariate analysis. Patients with the diagnosis of critical limb ischemia (14.9%) and patients undergoing open lower extremity revascularization (14.6%) had the highest rates of unplanned 30-day rehospitalization. In the prospective portion of this study, no patient was readmitted to any other hospital.

CONCLUSIONS

Relatively low 30-day rehospitalization was accomplished in vascular surgery patients at a single university hospital. Moreover, planned rehospitalizations accounted for approximately 25% of readmissions in vascular surgery patients. Strategies designed to reduce rehospitalization in diabetics may be warranted.

Peripheral artery disease. Part 1: clinical evaluation and noninvasive diagnosis

Peripheral artery disease (PAD) is a marker of systemic atherosclerosis. Most patients with PAD also have concomitant coronary artery disease (CAD), and a large burden of morbidity and mortality in patients with PAD is related to myocardial infarction, ischemic stroke, and cardiovascular death. PAD patients without clinical evidence of CAD have the same relative risk of death from cardiac or cerebrovascular causes as those diagnosed with prior CAD, consistent with the systemic nature of the disease. The same risk factors that contribute to CAD and cerebrovascular disease also lead to the development of PAD. Because of the high prevalence of asymptomatic disease and because only a small percentage of PAD patients present with classic claudication, PAD is frequently underdiagnosed and thus undertreated. Health care providers may have difficulty differentiating PAD from other diseases affecting the limb, such as arthritis, spinal stenosis or venous disease. In Part 1 of this Review, we explain the epidemiology of and risk factors for PAD, and discuss the clinical presentation and diagnostic evaluation of patients with this condition.

Diabetic microangiopathy in the liver: an autopsy study of incidence and association with other diabetic complications

Diabetic hepatosclerosis (DH) is a recently described form of diabetic microangiopathy with hepatic sinusoidal fibrosis and basement membrane deposition without cirrhosis. The objective was to investigate the frequency of DH and its correlation with other diabetic microangiopathic complications. Complete autopsies from 57 adults with diabetes were reviewed for liver pathology and other diabetic complications. Basement membrane deposition in the liver was highlighted using laminin and type IV collagen immunostains. Only 1 case of DH was identified. Other diabetic end-organ damage in this case included nodular glomerulosclerosis and hepatic hyaline arteriolosclerosis, which were the most severe in the series. DH is an uncommon pattern of liver disease in patients with diabetes and is associated with severe end-organ damage. This study supports the presumed vascular etiology of DH, confirms the rarity of the lesion, and supports the suggestion that it is usually accompanied by other end-organ damage.

Perioperative blood glucose monitoring and control in major vascular surgery patients

Diabetes mellitus (DM) is an independent predictor for morbidity and mortality in the general population, which is even more apparent in patients with concomitant cardiovascular risk factors. As the prevalence of DM is increasing, with an ageing general population, it is expected that the number of diabetic patients requiring surgical interventions will increase. Perioperative hyperglycaemia, without known DM, has been identified as a predictor for morbidity and mortality in patients undergoing surgery. Moreover, early studies showed that intensive blood-glucose-lowering therapy reduced both morbidity and mortality among patients admitted to the postoperative intensive care unit (ICU). However, later studies have doubted the benefit of intensive glucose control in medical-surgical ICU patients. This article aims to comprehensively review the evidence on the use of perioperative intensive glucose control, and to provide recommendations for current clinical practice. A systematic review was performed of the literature on perioperative intensive glucose control. Based on this literature review, we observed that intensive glucose control in the perioperative period has no clear benefit on short-term mortality. Intensive glucose control may even have a net harmful effect in selected patients. In addition, concerns on the external validity of some studies are important barriers for widespread recommendation of intensive glucose control in the perioperative setting. We propose that guidelines recommending intensive glucose control should be re-evaluated. In addition, moderate tight glucose control should currently be regarded as the safest and most efficient approach to patients undergoing major vascular surgery.

The use of therapeutic gene eNOS delivered via a fibrin scaffold enhances wound healing in a compromised wound model

Diabetic healing is marked by a reduced nitric oxide (NO) production at the wound site. This study aimed to investigate whether a fibrin scaffold would enhance the delivery of adenovirus encoding endothelial nitric oxide synthase (eNOS), one of the enzymes responsible for NO production, resulting in more NO production, and enhanced healing. An alloxan rabbit ear ulcer model was used to investigate healing, in response to the following treatments: fibrin containing AdeNOS, AdeNOS alone, fibrin alone and no treatment. Immunohistochemistry to detect eNOS expression and histological evaluation of healing were assessed at 7 and 14 days. eNOS expression was significantly greater in the fibrin containing AdeNOS group at 14 days compared to all other groups. Furthermore, this group showed a significantly faster rate of epithelialisation than all other groups. The volume of inflammatory cells was highest in the fibrin containing AdeNOS group at 7 days, which dropped significantly by 14 days. Likewise, the surface area and length of vessels reduced significantly in the fibrin containing AdeNOS group between 7 and 14 days indicating tissue remodelling, but remained stable in all other groups. Regression analysis showed that the epithelialisation rate was significantly affected by change in eNOS expression, inflammation, and surface area and length of vessels over time in the fibrin containing AdeNOS group. It was concluded that fibrin delivery of AdeNOS resulted in enhanced eNOS expression, inflammatory response, and a faster rate of re-epithelialisation.

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.

Hind Limb Ischemia-Reperfusion in the Leptin Receptor Deficient (db/db) Mouse

BACKGROUND

Diabetic patients have high incidence of peripheral vascular disease and limb loss after acute extremity injury. Experiments were designed to test the hypothesis that acute tissue injury in leptin receptor deficient (Db) diabetic (type2) mice would be more severe than in non-diabetic mice.

METHODS

Db and wild type (Wt) mice were subjected to 3 h of ischemia followed by either 4 or 24 h of reperfusion (3/4 IR, 3/24 IR). Muscle analyzed for tissue viability (mitochondrial activity), cytokines (KC-murine equivalent of human IL-8, TNFalpha, IL-6), growth factor, and histological evaluation (neutrophils/uninjured muscle fibers). Tissue perfusion was detected during basal and reperfusion conditions using laser Doppler imaging.

RESULTS

Mitochondrial activity and histological evaluation for tissue injury did not differ in the Db versus Wt mice at the time intervals studied. When compared with their respective sham animals, both Db and Wt mice had similarly increased levels of KC, IL-6, and VEGF after 3/24 IR. TNFalpha levels increased in Db but not Wt mice after IR. Although absolute increases in TNFalpha and KC were higher in Db mice, VEGF levels were actually lower in the Db mice.

CONCLUSION

The patterns of tissue perfusion, cytokines, and growth factors were different in Db versus Wt mice. At the acute time intervals studied, these differences did not correlate with an expected greater degree of acute muscle injury in Db mice.

Near infrared diffuse optical tomography: improving the quality of care in chronic wounds of patients with diabetes

A frequency domain diffuse optical tomography instrument operating in the Near Infrared region (680-830nm) has been designed and used to monitor healing in diabetic wounds in a rat animal model. Instrument design and calibration are described and preliminary data of the in vivo experiment are reported. Excellent discrimination capability between the control and the diabetic population is possible, while the time course of impaired healing in diabetic animals appears to have different optical coefficients from the normal healing in the control group.

Hypoxia attenuates insulin-induced proliferation and migration of human diabetic infrapopliteal vascular smooth muscle cells

The proliferative effects of insulin on infrapopliteal vascular smooth muscle cells (VSMCs) have been established. We examined the effect of hypoxia in the presence and absence of insulin on the proliferation and migration of human diabetic infrapopliteal VSMCs in vitro. VSMCs isolated from the infrapopliteal arteries of male diabetic patients of identical disease and clinical patterns undergoing below-knee amputation were harvested and grown to subconfluence. Cells were then exposed to control medium (M199/1% fetal bovine serum/2% antibiotic-antimycotic) or control medium with 100 ng/mL insulin in oxygen concentrations of 17% (normoxia), 5%, and 1%. Cellular proliferation was assayed using [methyl-3H]-thymidine incorporation. Migration assays were performed using the Corning Costar Transwell system. Lactate dehydrogenase was assayed and compared among groups as a marker for cytotoxicity. VSMCs in normoxic conditions (17%) had a significant increase in both proliferation (100 +/- 6.5% vs. 124 +/- 4.7%, p = 0.007) and migration [73.2 +/- 9.3 vs. 118.1 +/- 14.9 cells/4 high-power fields (HPF), p = 0.03] when exposed to insulin. Of cells exposed to insulin, those at both 5% (75.9 +/- 7.9%, p = 0.0001) and 1% (73.6 +/- 4%, p < 0.0001) hypoxia proliferated at a significantly decreased rate compared with cells at normoxia (124 +/- 4.7%). Migration of these insulin-exposed cells was significantly decreased at 1% hypoxia (63.1 +/- 9.0 cells/4HPF) compared to those at normoxia (118.1 +/- 14.9 cells/4HPF, p = 0.006) and 5% hypoxia (101.2 +/- 10.0 cells/4HPF, p = 0.01). There were no significant differences in migration between cells at normoxia and 5% hypoxia. Finally, hypoxia and insulin exerted no significant effect on cytotoxicity. The proliferative and promigratory effects of insulin on diabetic VSMCs are attenuated in hypoxic conditions in a manner unrelated to cytotoxicity.

Meeting AHA/ACC secondary prevention goals in a vascular surgery practice: An opportunity we cannot afford to miss

OBJECTIVE

In an effort to reduce cardiovascular mortality, patients with atherosclerotic arterial disease should undergo risk factor modification according to the American Heart Association/American College of Cardiology (AHA/ACC) Secondary Prevention Guidelines (hereafter, Guideline). We assessed compliance with the Guideline in a group of patients seen in a vascular surgery practice.

METHODS

We evaluated 200 consecutive patients with lower-extremity occlusive disease, cerebrovascular disease, or abdominal aortic aneurysm seen by a university-based vascular surgery practice. The subjects were patients who had been seen previously in our clinic (ESTABLISHED) and new referrals (NEW). Data pertinent to each of the nine AHA/ACC Guideline goals were collected from patient interviews, medication histories, and laboratory records. Compliance with each of the Guideline goals was evaluated. Differences in compliance between ESTABLISHED and NEW patient groups were also compared. We also recorded whether a patient had a previous endovascular or open surgical vascular intervention (EVENT or NO EVENT). Differences in compliance between the EVENT and NO EVENT groups were compared.

RESULTS

Most patients did not achieve the secondary prevention goals recommended in the Guideline. Patients who had a prior vascular intervention (EVENT) were significantly more likely to achieve goals for low-density lipoprotein level (43% vs 23%), and for statin (71% vs 39%), beta-blocker (46% vs 27%), angiotensin-converting enzyme inhibitor (53% vs. 35%), and antiplatelet agent (85% vs. 68%) use (P < .05). ESTABLISHED patients were significantly more likely than NEW patients to have a prior EVENT (87% vs 47%, P < .0005). ESTABLISHED patients were significantly more likely than NEW patients to achieve goals for low-density lipoprotein level, beta-blocker, and statin use; however, these differences were likely due to the higher proportion of EVENT patients in the ESTABLISHED group.

CONCLUSION

Compliance with the Guideline is suboptimal in patients with atherosclerotic arterial disease. Secondary prevention goals were more often achieved in the EVENT patient group, suggesting that a vascular intervention may lead to increased patient and physician awareness and compliance with the Guideline. A targeted effort towards risk factor modification in patients with atherosclerotic arterial disease could improve compliance with the Guideline and reduce cardiovascular mortality.

Trends in the Presentation and Surgical Management of the Acute Diabetic Foot

BACKGROUND

This study examines trends in the presentation and surgical management of acute diabetic foot problems in a single institution.

METHOD

Prospective audit of all diabetic patients who had a primary procedure for critical lower limb ischaemia (CLI) and/or foot sepsis between 1st January 1990 and 31st December 2002. Primary and secondary intervention, mortality and limb salvage rate within 6 weeks of the index procedure were recorded.

RESULTS

There were 661 patients (417 men and 244 women of median age 69, range 31-99, years) with 799 affected limbs. CLI alone was present in 625 (78%) limbs, combined CLI and foot sepsis in 53 (7%) and foot sepsis alone in 121 (15%). The primary intervention was minor amputation in 323 (40%) limbs, revascularisation in 288 (36%), major amputation in 185 (23%) and sympathectomy in three limbs. Within 6 weeks, 125 (16%) limbs required secondary intervention, the peri-procedural mortality rate was 38 of 924 (4%), and the limb salvage rates for patients with CLI, combined CLI and sepsis and sepsis alone were 66, 66 and 80%, respectively. There was a significant decline in the proportion of patients presenting with CLI alone and a significant increase in the proportion presenting with combined CLI and sepsis and sepsis alone. In patients with CLI alone, there was a significant increase in the primary major amputation rate and a significant decline in the minor amputation rate with no significant change in the revascularisation rate.

CONCLUSION

There has been a progressive decline in the proportion of patients presenting with CLI alone and a greater proportion of patients presenting with an element of foot sepsis. In patients with CLI alone, the primary major amputation rate has increased at the expense of a decline in minor amputation rate.