Peripheral Vascular Reconstruction Research Articles

Three-layer collagen-based vascular graft designed for low-flow peripheral vascular reconstructions.

The aim of this study was to develop a prototype of an artificial blood vessel which has similar mechanical properties to a human saphenous vein graft and to experimentally verify the function of the prosthesis via ovine carotid bypass implantation. The prototype of an artificial graft prosthesis for low flow was developed and manufactured from a collagenous matrix and reinforcing polyester mesh. We compared the results of both the pressurisation and the mechanical stress evaluation tests of VSM with four types of hybrid vascular graft. The most similar graft (type II) was chosen for the first ovine model implantation. Dominant behavior e.g. mechanical response of VSM graft in plots of circumferential and axial stress during loading is observed in circumferential direction. Average results of used VSM showed area of ideal mechanical response and the properties of artificial blood vessels were fitted into this area. Developed graft remained patent after 161 days of follow up in ovine model. The mechanical properties of the graft were designed and adjusted to be similar to the behaviour of human saphenous veins. This approach showed promising results and enhanced the final performance of the prosthesis.

Peripheral artery reconstructions using cryopreserved arterial allografts in infected fields

ObjectiveCryopreserved human arterial allografts are a recognized acceptable alternative for vascular reconstruction when other traditional conduits are either unavailable or contraindicated. We reviewed our experience using cryopreserved arterial allografts for peripheral artery reconstructions in contaminated and infected surgical fields. MethodsA single-center, retrospective review was conducted of 57 patients who underwent a peripheral vascular reconstruction using a cryopreserved arterial allograft from January 2002 through July 2017. Indications for repair included removal of infected prosthetic bypass (n = 29), revascularizations in contaminated fields (n = 11), primary arterial repair in the setting of infection (n = 10), and infected vascular closure devices (n = 7). Aorta-based repairs were excluded. Demographics, index procedural details, postoperative complications, and conduit patency were analyzed. Primary end points included conduit-related mortality and graft failure as measured by reinfection, hemorrhage, or aneurysmal degeneration. Mean follow-up for the study is 27.8 months (range, 2-125 months). ResultsA total of 57 peripheral vascular reconstructions using cryopreserved arterial allografts were performed during the 15-year period. Among the 22 women and 35 men treated, the mean age was 61 years. The vascular beds involved included iliofemoral (n = 39), femoropopliteal or femoral-distal (n = 10), axillosubclavian or brachial (n = 2), mesenteric (n = 3), and carotid (n = 3) arteries. Adjunctive muscle flap coverage of the allograft conduit was performed in the majority of cases (61%; n = 35). The 30-day mortality was 9%; one death was directly related to conduit insertion. The 30-day conduit-related complication rate was 14% and included hemorrhage from the graft requiring return to the operating room (n = 4) and graft infection (n = 4). The late conduit-related complication rate was 15.8% and included graft infection (n = 1), graft thrombosis (n = 3), major amputation resulting from conduit failure (n = 1), pseudoaneurysm degeneration requiring repair (n = 2), graft hemorrhage (n = 1), and symptomatic graft stenosis (n = 1). ConclusionsA cryopreserved arterial allograft is a useful alternative conduit for peripheral vascular reconstruction in infected or contaminated surgical fields when other autologous or prosthetic conduits are either unavailable or contraindicated. In the immediate postoperative period, these repairs demonstrate acceptable resistance to graft failure and reinfection, particularly in conjunction with adjunctive rotational muscle flap coverage. Late conduit-related complications appear to be infrequent.

Role of Dipyrone in the High On-Treatment Platelet Reactivity amongst Acetylsalicylic Acid-Treated Patients Undergoing Peripheral Artery Revascularisation

Objective: To evaluate the effects of dipyrone on sensitivity to aspirin (acetylsalicylic acid [ASA]) in patients who underwent peripheral artery vascular reconstruction. Subjects and Methods: Impedance aggregometry and light transmission aggregometry were used to determine the effects of dipyrone on ASA treatment in 21 patients. Blood samples were drawn in a 7-day period after the surgery. The cut-off value for high on-treatment platelet reactivity (HTPR) was set at < 65% of aggregation inhibition for impedance aggregometry. For light transmission aggregometry the cut-off value for arachidonic acid-induced aggregation was set at > 20% of aggregating platelets, and the cut-off value for epinephrine-induced aggregation was > 44% of aggregating platelets. The cut-off value for each method was derived from a large number of patients treated with a daily dose of 100 mg of ASA. Results: We found HTPR in 14 (67%) of the 21 patients. None had primary resistance to ASA, i.e., after the addition of ASA in vitro all samples showed antiplatelet efficacy. Regression analysis showed a possible correlation between lower efficacy of ASA treatment and higher daily doses of dipyrone (p = 0.005 for impedance aggregometry, p = 0.04 for light transmission aggregometry), higher platelet count (p = 0.005 for impedance aggregometry), and shorter time from surgery (p = 0.03 for impedance aggregometry). Conclusion: HTPR occurs in 67% of ASA-treated patients after lower limb vascular surgery. The occurrence of HTPR correlates with the daily dose of dipyrone. Therefore, dipyrone should not be used as a postoperative analgesic in ASA-treated patients after peripheral artery revascularisation due to its influence on the effectiveness of ASA.

In Vivo Evaluation of Short-Term Performance of New Three-Layer Collagen-Based Vascular Graft Designed for Low-Flow Peripheral Vascular Reconstructions.

Aim The aim of this study was to evaluate short-term patency of the new prosthetic graft and its structural changes after explantation. Methods The study team developed a three-layer conduit composed of a scaffold made from polyester coated with collagen from the inner and outer side with an internal diameter of 6 mm. The conduit was implanted as a bilateral bypass to the carotid artery in 7 sheep and stenosis was created in selected animals. After a period of 161 days, the explants were evaluated as gross and microscopic specimens. Results The initial flow rate (median ± IQR) in grafts with and without artificial stenosis was 120 ± 79 ml/min and 255 ± 255 ml/min, respectively. Graft occlusion occurred after 99 days in one of 13 conduits (patency rate: 92%). Wall-adherent thrombi occurred only in sharp curvatures in two grafts. Microscopic evaluation showed good engraftment and preserved structure in seven conduits; inflammatory changes with foci of bleeding, necrosis, and disintegration in four conduits; and narrowing of the graft due to thickening of the wall with multifocal separation of the outer layer in two conduits. Conclusions This study demonstrates good short-term patency rates of a newly designed three-layer vascular graft even in low-flow conditions in a sheep model.

Surgical vein graft preparation promotes cellular dysfunction, oxidative stress, and intimal hyperplasia in human saphenous vein

Human saphenous vein (HSV) is the most widely used bypass conduit for peripheral and coronary vascular reconstructions. However, outcomes are limited by a high rate of intimal hyperplasia (IH). HSV undergoes a series of exvivo surgical manipulations prior to implantation, including hydrostatic distension, marking, and warm ischemia in solution. We investigated the impact of surgical preparation on HSV cellular function and development of IH in organ culture. We hypothesized that oxidative stress is a mediator of HSV dysfunction. HSV was collected from patients undergoing vascular bypass before and after surgical preparation. Smooth muscle and endothelial function were measured using a muscle bath. Endothelial preservation was assessed with immunohistochemical staining. An organ culture model was used to investigate the influence of surgical preparation injury on the development of IH. Superoxide levels were measured using a high-performance liquid chromatography-based assay. The influence of oxidative stress on HSV physiologic responses was investigated by exposing HSV to hydrogen peroxide (H2O2). Surgical vein graft preparation resulted in smooth muscle and endothelial dysfunction, endothelial denudation, diminished endothelial nitric oxide synthase staining, development of increased IH, and increased levels of reactive oxygen species. Experimental induction of oxidative stress in unmanipulated HSV by treatment with H2O2 promoted endothelial dysfunction. Duration of storage time in solution did not contribute to smooth muscle or endothelial dysfunction. Surgical vein graft preparation causes dysfunction of the smooth muscle and endothelium, endothelial denudation, reduced endothelial nitric oxide synthase expression, and promotes IH in organ culture. Moreover, increased levels of reactive oxygen species are produced and may promote further vein graft dysfunction. These results argue for less injurious means of preparing HSV prior to autologous transplantation into the arterial circulation.

Peripheral vascular reconstruction using deep vein graft for critically ill patients

The great saphenous veins are gaining wide popularity as acceptable native vascular grafts, but in terms of flow capacity, their small caliber may be unsuitable for immediate replacement of arterial flow. Ten peripheral vascular or central venous reconstructions were performed using superficial femoral vein free grafts for re-establishment of immediate high-flow patency. Seven of the patients were men with a mean age of 61.5 ± 17.9 years (range, 21-81 years). The majority of the patients were of preoperative or intraoperative critically ill statuses in that they had extensive infection (n = 5), bleeding (n = 4), renal failure (n = 3) or hepatic failure (n = 1). The mean preoperative physiology score of the vascular POSSUM was 24.1 ± 8.8 (range, 15-37), and the mean operative severity score was 18.4 ± 4.9 (range, 10-26). All patients survived and recovered from systemic infection or critical hemodynamic instability. During the mean 28.9 months of follow-up, complications such as aneurysmal dilation, recurrent infection, graft stenosis/occlusion, lower limb edema and other clinical problems that required attention were not observed. In conclusion, we determined that deep veins can be applied as ideal graft conduits for reconstructing the major peripheral vessels under complicated conditions in select patients.

Four-year surveillance study of metal clip anastomoses in peripheral arterial reconstruction

In our preliminary study four years ago, using vascular closure staple (VCS) clips in making arterial anastomoses in peripheral vascular reconstructions, we showed that clip closure is easy and safe in early long-term (an average of 11 months) follow-up. In the present study we re-examined all the patients who had been bypassed using VCS clips in our earlier study. All together, ten of 17 patients were clinically examined, the ankle brachial index was measured, and a duplex Doppler examination was performed. The mean ankle brachial index in the operated leg of seven patients was 1.01 (range, 0.78–1.52). The anastomoses of nine patients were patent and neither turbulent blood flow nor aneurysms were seen. Only a PTFE prosthesis was occluded. The long-term experience of using metal clips in the peripheral vascular reconstructions seems to be encouraging, because the patency of grafts is good and no adverse reactions, such as aneurysms, were seen during the four-year surveillance period.

Predictive values of risk factors in carotid duplex scanning before peripheral vascular surgery

The objective of this study was to determine the predictive values of multiple atherosclerotic risk factors in using routine carotid duplex scanning for patients with peripheral vascular disease, even in the absence of any sign of carotid disease. From 1998 through 2000, 108 patients admitted for peripheral vascular reconstruction to our institution were preoperatively screened for carotid artery stenosis. Patients were examined for neurologic status and cervical bruits. As atherosclerotic risk factors, hyperlipidemia, diabetes, smoking, sex and age, coronary artery disease (CAD), coronary artery bypass surgery (CABG), and previous vascular operation were recorded, preoperative ankle-brachial pressure indexes (ABI) were calculated. All patients underwent routine carotid color duplex examinations preoperatively. Eighty five patients (78.7%) had mild (<50%) or no carotid artery stenosis, and 23 patients (21.3%) had significant (≥50%) carotid artery stenosis. Age (≥60 years), coronary artery disease, and carotid bruit were individual factors, and the combination of age ≥55 and hyperlipidemia had a significant value in predicting presence of ≥50% stenosis of one or both carotid arteries by univariate analysis. By multivariate logistic regression analysis, however, only carotid bruit was associated with carotid artery stenosis of ≥50% (p<0.001). Screening for asymptomatic carotid artery stenosis is indicated in patients with only carotid artery bruit and might be indicated in elderly patients with peripheral vascular disease. Routine screening or carotid artery stenosis in all patients is not an effective strategy.

Management of Vascular Graft Infections with Soft Tissue Flap Coverage: Improving Limb Salvage Rates–A Veterans Affairs Experience

Graft infections are one of the most challenging issues in surgery with an incidence of 0.7 to 7 per cent, with femoral site infections being the most common (13% incidence). The gold standard treatment has been graft removal, wide débridement, and extra-anatomical bypass. Routine excision of infected peripheral arterial grafts and vascular reconstruction with extraanatomic conduits are associated with mortality rates ranging from 10 to 30 per cent and amputation rates of up to 70 per cent. As a result of the high morbidity and mortality associated with this approach, selective graft preservation techniques have been developed. Newer treatment plans discuss preservation of the graft with débridement and coverage of the infected region. Better wound care, nutrition optimization, and robust flap coverage have led to significantly improved graft salvage, lower amputation rates, and improved outcomes. The objective of this study was to evaluate the Veterans Affairs (VA) experience with flap coverage for femoral vascular graft infections. A retrospective review was conducted of all VA data from 1997 to 2008 with inclusion criteria of patients with deep groin wound infections requiring flap coverage after femoral bypass surgery. Eleven such patients were identified with a mean age of 73 years and with multiple comorbidities (hypertension, malnutrition, diabetes mellitus, chronic obstructive pulmonary disease, coronary artery disease, chronic renal insufficiency). Patients presented with wound drainage, exposed graft, hematoma, perigraft fluid collection, and pseudoaneurysm. Treatment protocol included: 1) aggressive débridement of the wound bed; 2) early soft tissue (flap) coverage; 3) wound vacuum assisted closure device or frequent dressing changes; and 4) skin graft once the bed was prepared. Eighty-two per cent of wounds had positive cultures with equal numbers of patients with Staphylococcus epidermidis, Pseudomonas, Escherichia coli (22%), and higher methicillin-resistant Staphylococcus aureus (33%), whereas in the literature Staphylococcus is the most common (greater than 50%). Average hospital length of stay was 94 days with average follow up at 10 months. Fifty-five per cent graft salvage (one Dacron [50%], two polytetrafluoroethylene [33%], two saphenous vein graft [100%], one cryovein [100%]) was achieved with 91 per cent limb salvage. Complications included graft blowout (two) requiring partial flap loss (one), retroperitoneal hematoma (one), limb loss (one), sepsis (one), and death (one). Infected vascular grafts remain a challenging problem requiring multidisciplinary care. Careful débridement and aggressive wound care followed by selective flap coverage appears to decrease morbidity and increase graft and limb salvage.

A randomized, controlled, prospective trial to evaluate the haemostatic effect of Lyostypt versus Surgicel in arterial bypass anastomosis: "COBBANA" trial

BackgroundThe development of suture hole bleeding at peripheral arterial bypass anastomoses using PTFE graft prostheses is a common problem in peripheral vascular surgery. Traditionally the problem is managed by compression with surgical swabs and reversal heparin or by using several haemostatic device (e.g. different forms of collagen, oxidized cellulose, gelatine sponge, ethylcyanoacrylate glue or fibrin) with various success. Preclinical data suggest that the haemostatic effect of collagen is stronger than that of oxidized cellulose, but no direct clinical comparison of their hemostatic performance has been published so far.DesignThis randomized, controlled, prospective trial evaluates the haemostatic effect of Lyostypt versus Surgicel in arterial bypass anastomosis. 28 patients undergoing an elective peripheral vascular reconstruction due to peripheral vascular disease will be included. Suture hole bleeding occurring at the arterial bypass anastomosis using a PTFE prostheses will be stopped by the application of Lyostypt and/or Surgicel. The proximal anastomoses will be randomized intraoperatively. The patients will be allocated into 4 different treatment groups. Group1 Lyostypt distal/Surgicel proximal; Group 2: Lyostypt proximal/Surgicel distal; Group 3: Surgicel distal and proximal; Group 4: Lyostypt distal and proximal. Primary endpoint of the study is time to haemostasis. Secondary endpoints are the number of intraoperatively used haemostatic devices, postoperative mortality within 30 days as well as the intraoperative efficacy rating of the two devices evaluated by the surgeon. As a safety secondary parameter, the local and general complication occurring till 30 ± 10 days postoperatively will also be analysed. After hospital discharge the investigator will examine the enrolled patients again at 30 days after surgery.DiscussionThe COBBANA trial aims to assess, whether the haemostatic effect of Lyostypt is superior to Surgicel in suture hole bleedings of arterial bypass anastomoses.Trial registrationNCT00837954

Profile of Cardiovascular Risk Factors and Mortality in Patients with Symptomatic Peripheral Arterial Disease

INTRODUCTION:The present study examines cardiovascular risk factor profiles and 24-month mortality in patients with symptomatic peripheral arterial disease.DESIGN STUDY:Prospective observational study including 75 consecutive patients with PAD (67 ± 9.7 years of age; 52 men and 23 women) hospitalized for planned peripheral vascular reconstruction. Doppler echocardiograms were performed before surgery in 54 cases. Univariate analyses were performed using Student’s t-test or Fisher’s exact test. Survival analysis at 24-month follow-up was performed using the Cox regression model and Kaplan-Meier method including age and chronic use of aspirin as covariates. Survival curves were compared using the log-rank test.RESULTS:Hypertension and smoking were the most frequent risk factors (52 cases and 51 cases, respectively), followed by diabetes (32 cases). Undertreated dyslipidemia was found in 26 cases. Fasting glycine levels (131 ± 69.1 mg/dl) were elevated in 29 cases. Myocardial hypertrophy was found in 18 out of 54 patients. Thirty-four patients had been treated with aspirin. Overall mortality over 24 months was 24% and was associated with age (HR: 0.064; CI95: 0.014–0.115; p=0.013) and lack of use of aspirin, as no deaths occurred among those using this drug (p<0.001). No association was found between cardiovascular death (11 cases) and the other risk factors.CONCLUSION:There is a high prevalence of uncontrolled (treated or untreated) cardiovascular risk factors in patients undergoing planned peripheral vascular reconstruction, and chronic use of aspirin is associated with reduced all-cause mortality in these patients.

12: Inhibition of phosphorylation of HSP27 decreases vasospasm in human saphenous vein

Saphenous vein is used as a conduit for peripheral vascular and coronary reconstruction. However, surgical manipulation during harvest of the vessel often leads to vasospasm. Impaired relaxation is one of the main reasons for vein graft spasm. The small heat shock proteins, HSP20 and HSP27, coordinately regulate vascular smooth muscle (VSM) tone. We hypothesized that inhibiting the phosphorylation of HSP27 may increase sodium nitroprusside (SNP) induced phosphorylation of HSP20 and relaxation of saphenous vein. Human saphenous vein (HSV) rings were equilibrated in a muscle bath, treated with contractile and relaxing agents and the force generated was recorded. Muscle rings were frozen, and extracted proteins were analyzed for HSP20 and HSP27 phosphorylation by gel electrophoresis and western blotting. HSV contracted dose-dependently to norepinephrine (NE) and relaxed dose-dependently to sodium nitroprusside (SNP), a nitric oxide donor. Pre-incubation of HSV with SB203580 (50 μM), an inhibitor of p38 MAP Kinase, which is upstream of MAPKAP kinase II (the kinase that directly phosphorylates HSP27), increased SNP (1 μM) relaxation of HSV from 20% +/- 8% to 62% +/- 12% (p< 0.05, n=5, +/-SEM) . SB203580 pre-treatment also reduced the magnitude of NE induced contraction by (50% +/1 9%). SB treatment decreased the basal phosphorylation of HSP27 (Ser 82 and Ser 15) by 68% and increases SNP stimulated phosphorylation of HSP20 (Ser 16) by 20%. These results suggest that SB203580 treatment can reduce the magnitude of agonist induced contraction. This was associated with a decrease in the basal level of HSP27 phosphorylation. In addition, decreases in HSP27 phosphorylation were associated with increased SNP induced phosphorylation of HSP20 and relaxation. These results suggest that the two small heat shock proteins, HSP20 and HSP27 may have opposing effects in mediating vascular tone and that inhibiting the phosphorylation of HSP27 may be a therapeutic approach for preventing vasospasm.

Guidelines for the treatment of arterial insufficiency ulcers

1. Co-chaired panel 2. University of Utah, Salt Lake City, UT 3. University of Texas, San Antonio, TX 4. Sinai Hospital/Johns Hopkins Medical Institutions, Baltimore, MD 5. GKT School of Medicine, King’s College, London, UK 6. University of Texas Health Science Center at Houston, TX 7. Sequoia Hospital, Redwood City, CA 8. Maricopa Medical Center, Phoenix, AZ 9. Tufts-New England Medical Center, Boston, MA 10. Southampton University Hospitals Trust NHS, Southampton, UK 11. Penrose–St. Francis Health Services, Colorado Springs, CO 12. Beverly Surgical Associates, Beverly, MA 13. Saint Francis Memorial Hospital, San Francisco, CA 14. Northbay Center for Wound Care, Vacaville, CA, and 15. University of California, San Francisco, CA

Transducible recombinant small heat shock-related protein, HSP20, inhibits vasospasm and platelet aggregation

BackgroundHuman saphenous vein (HSV) is the autologous conduit of choice for peripheral vascular reconstruction. Injury during harvest leads to vasospasm and a thrombogenic endoluminal surface. A proteomic transduction approach was developed to prevent vein graft vasospasm and thrombosis. MethodsRecombinant HSP20 protein linked to the TAT protein transduction domain was generated in a bacterial expression system (TAT-HSP20). The effect of this protein on the inhibition of smooth muscle contraction was determined using rings of rabbit aorta and HSV in a muscle bath. In addition, the effects of TAT-HSP20 on platelet aggregation were determined in vitro using human citrated whole blood. ResultsRecombinant TAT-HSP20 inhibited norepinephrine-induced contraction of rabbit aortic and HSV segments. Similarly, TAT-HSP20 induced smooth muscle relaxation in HSV segments precontracted with norepinephrine. In human-citrated whole blood, platelet aggregation was significantly inhibited by TAT-HSP20 in a dose-dependent manner. ConclusionsThe results of this study demonstrate that recombinant TAT-HSP20 inhibits vascular smooth muscle contraction and platelet aggregation. This suggests that HSP20 may be an ideal effector molecule to target as a proteomic approach to enhance early vein graft patency rates by preventing acute vasospasm and thrombosis.

Can low molecular weight heparin replace unfractionated heparin during peripheral arterial reconstruction? An open label prospective randomized controlled trial

Objective This study was undertaken to evaluate the effect of low molecular weight heparin (LMWH) compared with unfractionated heparin (UFH) on the rate of occlusion and bleeding during peripheral vascular surgery. Methods The study was an open label, prospective, randomized trial, carried out by 20 Swedish surgical and vascular surgical departments that report to the Swedish Vascular Registry (SWEDVASC). Study subjects included patients undergoing peripheral vascular procedures, except carotid surgery. Of the 849 patients included, 817 were followed up to 30 days. LMWH (40 mg of enoxaparin) or UFH (5000 IU heparin) was given intravenously immediately before clamping. The same formulation in diluted form was used for vascular rinsing. Main outcome measures included patent reconstruction at day 1, perioperative blood loss, and the percentage of patients requiring protamin. Further, 30-day data for mortality, repeat operation, and recurrent occlusion are reported. Results The mortality rate at 30 days was 2.7%, with no difference between groups. The patency rate at 1 day was 91.2% to 98.4%, depending on diagnosis and type of reconstruction. No difference was recorded between study groups (0.6 < P < 1.0). At 30 days the patency rate was 83.1% to 100% (0.2 < P < .9). Median blood loss was 350 mL (interquartile range [IQR], 200-800 mL) in the LMWH group and 425 mL (IQR, 200-900 mL) in the UFH group ( P = .02). Protamin was given to significantly fewer patients in the LMWH group ( P = .001). LMWH was comparable to UFH during peripheral vascular reconstruction in terms of 1-day and 30-day graft patency, operative blood loss, and hemorrhagic complications. Protamine was required less often after LMWH. In this randomized trial LMWH was as effective as UFH in preventing thrombosis without excess bleeding or hemorrhagic complications.

Effects of leg and body position on transcutaneous oxygen measurements in healthy subjects and subjects with peripheral artery disease after lower-extremity arterial revascularization: A pilot study

Transcutaneous oxygen (TcPO2) measurements provide a noninvasive, objective determination of the oxygen level at the skin surface. This offers a means of estimating the underlying circulation and tissue oxygenation. The purpose of the pilot study was to measure the TcPO2 value of the lower extremity of healthy men and women and of patients with peripheral arterial disease (PAD) in 4 different body and leg positions 24 hours after peripheral vascular surgery reconstruction. The specific aim was to determine if lower-extremity TcPO2 measurements were affected by changes in extremity position in these subject populations. A convenience sample of 4 healthy health care professionals and 4 patients who had peripheral vascular reconstruction surgery 24 hours before the measurements were studied. Subjects were studied in 4 different leg and body positions: supine with legs extended, sitting with legs dependent, a 5° head-up reverse Trendelenburg, and supine with legs elevated 10 in. The Radiometer TCM30 TcPO2 monitor was used to carry out these measures. Findings revealed a statistically significant difference in TcPO2 measurements between the 2 groups, with the healthy subjects having a significantly higher TcPO2 measurement in all extremity positions compared with the revascularized subjects with PAD (P =.02−.05). Significant changes were noted in both the foot temperature (P =.03) and TcPO2 measurements with extremity positions within the healthy subject group (P =.001). The foot and leg TcPO2 measurements affect from leg and body position did not reach significance (P =.09) in the subjects with PAD. No change in foot temperature with extremity positioning (P =.42) was noted in the subjects with PAD. This pilot study provides a base in which additional research will be performed with TcPO2 measurements in both the healthy and revascularized person. (J Vasc Nurs 2002;20:125-35)

Predictive values of risk factors in carotid duplex scanning before peripheral vascular surgery

The objective of this study was to determine the predictive values of multiple atherosclerotic risk factors in using routine carotid duplex scanning for patients with peripheral vascular disease, even in the absence of any sign of carotid disease. From 1998 through 2000, 108 patients admitted for peripheral vascular reconstruction to our institution were preoperatively screened for carotid artery stenosis. Patients were examined for neurologic status and cervical bruits. As atherosclerotic risk factors, hyperlipidemia, diabetes, smoking, sex and age, coronary artery disease (CAD), coronary artery bypass surgery (CABG), and previous vascular operation were recorded, preoperative ankle-brachial pressure indexes (ABI) were calculated. All patients underwent routine carotid color duplex examinations preoperatively. Eighty five patients (78.7%) had mild (< 50%) or no carotid artery stenosis, and 23 patients (21.3%) had significant (≥ 50%) carotid artery stenosis. Age (≥ 60 years), coronary artery disease, and carotid bruit were individual factors, and the combination of age ≥ 55 and hyperlipidemia had a significant value in predicting presence of ≥ 50% stenosis of one or both carotid arteries by univariate analysis. By multivariate logistic regression analysis, however, only carotid bruit was associated with carotid artery stenosis of ≥ 50% (p < 0.001). Screening for asymptomatic carotid artery stenosis is indicated in patients with only carotid artery bruit and might be indicated in elderly patients with peripheral vascular disease. Routine screening or carotid artery stenosis in all patients is not an effective strategy.

The impact of factor V mutation on the risk for occlusion in patients undergoing peripheral vascular reconstructions.

to determine the impact of Factor V-Leiden on the patency of peripheral vascular reconstructions. prospective, open and consecutive study. a total of 775 patients, who were electively admitted between 1995 and 1997 to the vascular ward unit, were prospectively analysed for frequency of Factor V-Leiden mutation and patency of reconstruction (one month and one year). The patients were grouped into carotid, abdominal aortic aneurysm (AAA), renal artery, aortoiliac, infrainguinal, and venous categories according to procedures and anatomical sites. Post-reconstruction complications and associated risk factors were also analysed. in infrainguinal patients Factor V-Leiden was seen in 16% of the patients compared with 10% in the controls. (Odds ratio 1.60, CI 0.91-2.81). Hypertension, pulmonary disease and smoking were more frequent in individuals without Factor V-Leiden. Analysing all 775 reconstructions, occlusions were more frequent at one month (14% vs 12%) (p=0.02) in patients with Factor V-Leiden compared with patients without the mutation. Though this trend was also noted few patients having infrainguinal reconstructions, the difference was not significant (37% vs 22% (p=0.15) and 46% vs 27% (p=0.09) after 1 and 12 months, respectively). factor V mutation (Factor V-Leiden) was more frequent in patients having occluded vascular reconstructions. Further evaluation is needed.

Anaesthesia and vascular surgery in the elderly

Elderly patients undergoing vascular surgery have a high incidence of ischaemic heart disease, respiratory disease, hypertension and diabetes mellitus and a general reduction in physiological reserve. Assessment is complicated by reduced mobility and silent coronary artery disease. Meticulous preparation and careful management of anaesthesia are essential, with emphasis on cardiovascular stability, fluid balance, control of pain, maintenance of body temperature and appropriate use of intensive care facilities. Regional anaesthesia and analgesia may be helpful, promoting haemodynamic stability, early extubation and reduced respiratory complications in aortic surgery and, in peripheral vascular surgery, reducing the incidence of graft failure. Aortic clamping and unclamping require special attention and may precipitate cardiac decompensation. Invasive intravascular monitoring is required for aortic surgery and, in selected patients, for carotid endarterectomy or peripheral vascular reconstruction. Assessment of the adequacy of cerebral blood flow may be required during carotid surgery to indicate the need for shunt insertion. Patients usually present for vascular surgery because of atherosclerotic occlusive disease (peripheral vascular reconstruction, aortoiliac bypass and carotid endarterectomy) or aneurysmal disease (principally of the abdominal aorta). Both are conditions of later life and are often associated with other conditions, especially ischaemic heart disease, chronic respiratory disease, hypertension and diabetes mellitus. Assessment of these patients is particularly challenging because of limited exercise tolerance and mobility. Furthermore, the perioperative management may be problematic because of the interaction of haemodynamic and surgical stress, the effects of anaesthesia, underlying ischaemic heart disease and the reduced physiological reserve of the elderly patient.

The incidence, morbidity, and mortality of surgical procedures after orthotopic heart transplantation.

The authors present their experience with patients having undergone orthotopic heart transplantation (OHT) in whom surgical conditions subsequently developed that required operative intervention. The incidence, morbidity, and mortality of these procedures are reported. Several studies have evaluated the management options of biliary tract disease after OHT. Multiple reports of patients having undergone OHT who subsequently underwent peripheral vascular reconstructions, plastic reconstructive, and thoracic procedures also have been published. A chart review of 349 patients who underwent OHT between 1985 and 1996 was conducted to identify surgical procedures that were required in the post-transplant period. Their outcomes are reported. Of 349 patients who underwent OHT, conditions requiring 94 surgical procedures developed in 54 patients (15%). Biliary tract disease developed in 17 patients (5%) who required cholecystectomy, 2 of the 5 patients with acute cholecystitis died. Eight patients (2%) underwent orthopedic procedures with no operative mortality. Flap advancements for sternal wound infections were performed in five patients and four deaths occurred. Seventeen thoracic procedures were performed in 11 patients with an overall mortality of 45%. Twenty-one vascular procedures were performed on 17 patients with 1 delayed death due to a malignancy. Seven patients underwent procedures of the colon and rectum with no mortality. Seven patients underwent repair of inguinal or incisional hernias with no mortality. Various infections occurred with one resultant death after operative intervention. Six procedures were performed for diseases of the small intestine with no resultant mortalities. Patients having undergone OHT and chronic immunosuppression are at increased risk of having complications develop from infection. Acute cholecystitis and sternal wound infection caused an inordinate risk of complications and death. Malignancies developed in four patients who required surgical intervention. A heightened awareness of coexisting peripheral vascular disease in patients transplanted for ischemic cardiomyopathy should exist. Close screening before surgery and surveillance after surgery to identify risk factors for infection and vascular disease and to screen for malignancies are essential.