Peripheral Arterial Reconstruction Research Articles

Abstract 2039: Limb Flexion Compresses The Anterior Tibial Artery And Changes Its Take-off Angle In A Sex-Dependent Manner

Introduction: Peripheral Arterial Disease (PAD) operations and reconstructions continue to fail at high rates, particularly below the knee. During limb flexion, distal superficial femoral and popliteal arteries experience significant deformations that are thought to contribute to disease development, but the biomechanics of the tibial arteries below the knee have not been characterized. Methods: Perfused human cadavers (n=15, 81±9 years old, range 60-93 years, 9F/6M) were imaged with their limbs in standing (180°), walking (110°), sitting (90°), and fetal/gardening (60°) positions using Computerized Tomography (CT). Three-dimensional geometries of the below-knee arteries were reconstructed in Mimics software and used to assess the take-off angle of the anterior tibial artery (AT) and the distance from the AT take-off to the nearest AT side branch. Results: The AT take-off angle relative to the tibioperoneal trunk increased with more acute limb flexion, from 70±19° in standing to 81±24° in walking, 83±24° in sitting, and 89±27° in fetal/gardening postures (p<0.01 for all postures). The AT take-off angle was larger in females than in males (24% in standing and 35% in walking, sitting, and gardening postures, p <0.01), but there were no differences between left and right limbs of either sex (p=0.66-0.99). The distance from the AT take-off to the nearest AT side branch decreased with more acute limb flexion (p< 0.01 for all postures). Conclusions: Limb flexion increases the AT take-off angle in a sex-dependent manner and compresses the AT, potentially contributing to the differences in hemodynamics and arterial mechanics and affecting the development and progression of tibial artery pathology. A better understanding of the below-knee artery biomechanics can provide valuable insights for surgical planning and may lead to improvements in the success rate and durability of PAD repairs.

Cryopreserved arterial allografts vs autologous vein for arterial reconstruction in infected fields

ObjectivePeripheral arterial infections are rare and difficult to treat when an in situ reconstruction is required. Autologous vein (AV) is the conduit of choice in many scenarios. However, cryopreserved arterial allografts (CAAs) are an alternative. We aimed to assess our experience with CAAs and AVs for reconstruction in primary and secondary peripheral arterial infections. MethodsData from patients with peripheral arterial infections undergoing reconstruction with CAA or AV from January 2002 through August 2022 were retrospectively analyzed. Patients with aortic- or iliac-based infections were excluded. ResultsA total of 42 patients (28 CAA, 14 AV) with a mean age of 65 and 69 years, respectively, were identified. Infections were secondary in 31 patients (74%) and primary in 11 (26%). Secondary infections included 10 femoral-femoral grafts, 10 femoropopliteal or femoral-distal grafts, five femoral patches, four carotid-subclavian grafts, one carotid-carotid graft, and one infected carotid patch. Primary infection locations included six femoral, three popliteal, and two subclavian arteries. In patients with lower extremity infections, associated groin infections were present in 19 (56%). Preoperative blood cultures were positive in 17 patients (41%). AVs included saphenous vein in eight and femoral vein in six. Intraoperative cultures were negative in nine patients (23%), polymicrobial in eight (21%), and monomicrobial in 22 (56%). Thirty-day mortality occurred in four patients (10%), two due to multisystem organ failure, one due to graft rupture causing acute blood loss and myocardial infarction, and one due to an unknown cause post-discharge. Median follow-up was 20 months and 46 months in the CAA and AV group, respectively. Graft-related reintervention was performed in six patients in the CAA group (21%) and one patient in the AV group (7%). Freedom from graft-related reintervention rates at 3 years were 82% and 92% in the CAA and AV group, respectively (P = .12). Survival rates at 1 and 3 years were 85% and 65% in the CAA group and 92% and 84% in the AV group (P = .13). Freedom from loss of primary patency was similar with 3-year rates of 77% and 83% in the CAA and AV group, respectively (P = .25). No patients in either group were diagnosed with reinfection. ConclusionsCAAs are an alternative conduit for peripheral arterial reconstructions when AV is not available. Although there was a trend towards higher graft-related reintervention rates in the CAA group, patency is similar and reinfection is rare.

Prevention of infection in aortic or aortoiliac peripheral arterial reconstruction

Prevention of infection in aortic or aortoiliac peripheral arterial reconstruction

Prevention of infection in peripheral arterial reconstruction of the lower limb

Prevention of infection in peripheral arterial reconstruction of the lower limb

Diagnostic Accuracy of FDG PET for the Identification of Vascular Graft Infection

Fluorodeoxyglucose (FDG) positron emission tomography (FDG PET/CT) can be used to identify and localize infection in patients with vascular graft infections (VGI). We aimed to evaluate the diagnostic accuracy of 18F-FDG PET/CT by defining thresholds for standardized uptake value (SUV) and tissue-to-background ratio (TBR) that would accurately identify the presence of vascular graft infection. Patients with suspected VGI were prospectively recruited and underwent 18F-FDG PET/CT scans. Diagnosis was based on clinical, laboratory and radiologic findings, and blinded to the results of the PET/CT scan. Receiver operator characteristics (ROC) curve analysis was done to determine optimal thresholds for SUV and TBR. Our final cohort consisted of 28 patients with suspected VGI (mean±SD age 67±10years, 61% men), of which 15 patients (54%) had definitive VGI. The cohort included 61% prosthetics grafts and 39% stent-grafts. The type of graft included in this study were biologic (4%), Dacron (64%) and Polytetrafluoroethylene (32%). The location of the implanted grafts was aortic (54%) and peripheral arterial reconstruction (46%). The location of the peripheral graft was 77% in lower extremity and 23% in the upper extremity (arterio-venous grafts for dialysis access). Using ROC analysis, SUV max of 4.5, SUV mean of 3.7, and a TBR of 1.6 gave the best balance between sensitivity and specificity (93%/92%, 100%/92% and 93%/92%, respectively). All thresholds had an area under the curve ≥0.93 and correct reclassification rate ≥93%. Our data suggests that FDG PET/CT can be used to reliably and accurately diagnose VGI. The dual anatomic-physiologic information from FDG PET/CT can complement clinical diagnosis particularly in uncertain cases.

Late outcomes of surgical reconstruction of peripheral pulmonary arteries

ObjectiveThe ideal management of peripheral pulmonary artery stenosis is still controversial. We adopted a primary surgical approach to this complex lesion with excellent early outcomes. In this study, we analyzed our late outcomes. MethodsWe performed a retrospective review of 91 patients with biventricular anatomy who underwent peripheral pulmonary artery reconstruction from March 2008 to July 2020. Our surgical approach included either a single-stage complete repair through median sternotomy or a 2-stage repair through sternotomy/left thoracotomy, depending on the degree of distal involvement of the left pulmonary artery branches. ResultsMedian age was 26 months. Syndromic etiology was established in 54 patients (59.3%) versus nonsyndromic etiology in 37 patients (40.7%). Single-stage repair was achieved in 68 patients (74.7%). There were 2 (2.2%) in-hospital mortalities. The mean right ventricular to aortic systolic pressure ratio decreased from 1.07 ± 0.20 preoperatively to 0.32 ± 0.07 immediately postoperatively (P < .001), representing a 70.1% reduction. At 1-year postoperative catheterization, the mean right ventricular to aortic systolic pressure ratio was 0.28 ± 0.05 (P < .001 compared with immediately postoperative value). With a median follow-up of 68 months (IQR, 39-117.5 months), there was no late mortality after discharge. All patients were active and asymptomatic on the most recent follow-up. There were no early or late reinterventions on pulmonary arteries. ConclusionsLate outcomes of surgical reconstruction of peripheral pulmonary arteries are excellent and durable in various pathologies (syndromic and nonsyndromic) with a significant reduction in right ventricular to aortic systolic pressure ratio, low mortality, and no reintervention.

Invited commentary

Infections after placement of a prosthetic graft, for either aortic or peripheral arterial reconstruction, are feared and potentially devastating complications. These infections can have significant morbidity and can also lead to subsequent infections. In this issue of the Journal of Vascular Surgery, Fariñas et al report their experience with postoperative infectious complications after placement of prosthetic grafts for both lower extremity and aortic reconstruction. Their all-cause infection rate was 27.2%. The majority of infections were surgical site infections, and only two graft infections were noted. The authors identified preoperative active lower extremity soft tissue infection as an independent risk factor for infectious complications after both aortic and lower extremity operations. Although active lower extremity infection may not be able to be resolved for patients with advanced critical limb ischemia or those who undergo emergent aortic surgery, efforts should be undertaken to treat soft tissue infection before elective aortic aneurysm repair. Prolonged mechanical ventilation was noted to be a predictor for infectious complications after aortic surgery, once again emphasizing the importance of expeditious extubation in the immediate postoperative period, although it is unclear whether this is a marker of overall illness. There are several lessons to be learned from this analysis. Studies of postoperative infectious complications should not combine very different procedures together as “vascular surgery procedures.” To correctly identify high-risk patients and to set in place systems for improvement, each specific type of intervention and indication needs to be closely examined. Leg bypass and aortic surgery are very different from one another with regard to a number of issues. For example, postoperative nasogastric tubes are often used after aortic procedures and seldom after leg bypass. Prolonged intubation with postoperative tracheostomy placement is less of an issue for lower extremity bypass as it is for major open abdominal surgery. Finally, for aortic surgery, an operation performed for aneurysmal disease is very different from one executed to treat occlusive disease, and a ruptured aneurysm is much different from an elective aneurysm repair. To decrease these rates of postoperative infections, risks identification and interventions should be tailored for specific scenarios. Studies need to be optimally designed to answer the questions that they set up to ask. Future prospective work is needed as granular details are needed, including surgical and preparation technique. Risks factors identified in this study, such as poor glucose control, anemia, and prolonged ventilation, can also be analyzed and teased out to see if they are really factors that predict a poor outcome or merely markers for ill and sick patients with more advanced disease. As such, risk reduction methods should focus specifically on each procedure and indication. The opinions or views expressed in this commentary are those of the authors and do not necessarily reflect the opinions or recommendations of the Journal of Vascular Surgery or the Society for Vascular Surgery. Risk factors and outcomes for nosocomial infection after prosthetic vascular graftsJournal of Vascular SurgeryVol. 66Issue 5PreviewThe objective of this study was to determine risk factors for nosocomial infections (NIs) and predictors of mortality in patients with prosthetic vascular grafts (PVGs). Full-Text PDF Open Archive

New simple image overlay system using a tablet PC for pinpoint identification of the appropriate site for anastomosis in peripheral arterial reconstruction.

To evaluate the accuracy and utility of a new image overlay system using a tablet PC for patients undergoing peripheral arterial reconstruction. Eleven limbs treated with distal bypass surgery were studied. Three-dimensional images obtained by processing a preoperative contrast-enhanced computed tomography scan were superimposed onto the back-camera images of a tablet PC. We used this system to pinpoint a planned distal anastomotic site preoperatively and to make a precise incision directly above it during surgery. We used a branch artery near the distal anastomotic site as a reference point and the accuracy of the system was validated by comparing its results with the intraoperative findings. The precision of the system was also compared with that of a preoperative ultrasonographic examination. Both the image overlay system and ultrasonography (US) accurately identified the target branch artery in all except one limb. In that limb, which had a very small reference branch artery, preoperative US wrongly identified another branch, whereas the image overlay system located the target branch with an error of 10mm. Our image overlay system was easy to use and allowed us to precisely identify a target artery preoperatively. Therefore, this system could be helpful for pinpointing the most accurate incision site during surgery.

Surgical Reconstruction of Peripheral Pulmonary Arteries: Strategies, Outcomes, and New Classification

Pulmonary artery stenosis (PAS) is classified as central (types 1 and 2) and peripheral (type 3 affects proximal part of lobar arteries, type 4 affects proximal part of segmental arteries, and type 5 affects distal part of segmental arteries). In this study, we examine the outcomes of surgical reconstruction of peripheral PAS. We reviewed 31 patients with peripheral PAS who underwent surgical repair. Median age was 30months. Patients with intact ventricular septum (24patients) presented with severe right ventricular dilation and dysfunction and mean right ventricular to left ventricular pressure (RVSP/LVSP) ratio was 0.96 ± 0.25, 1.14 ± 0.23, and 1.43 ± 0.07 for types 3, 4, and 5, respectively (p= 0.03). Pulmonary artery reconstruction was achieved in single stage in 19 patients (61%). Six patients (19%) had type 3, 22 patients (71%) had type 4, and 3 patients (10%) had type 5. mean number of angioplasties per patient was 18 ± 8. There was no earlymortality. Mean postoperative RVSP/LVSP ratio decreased to 0.27 ± 0.08, 0.36 ± 0.05, and 0.96 ± 0.06, for types 3, 4, and 5, respectively (p < 0.001). The median follow-up was 48 months. Patients with type 3 and 4 showed marked improvement in functional status after surgery. Patients with type 5 showed clinical evidence of improved cardiac output despite modest decrease in RVSP. No surgical re-intervention was needed, while balloon dilation was performed in 1 patient with type 5 lesions. Surgical reconstruction of diffuse peripheral PAS is feasible and associated with excellent hemodynamic and functional outcomes in patients where there is no involvement of the distal part of segmental arteries.

Content, accuracy and completeness of patient consent in a regional vascular surgery unit.

Although the General Medical Council has published guidelines for procedural consent, there is evidence to suggest that deficiencies still occur in completion demographics, documentation of procedural risks and information regarding alternative therapies. We assessed the accuracy and completeness of vascular consent within our unit. A retrospective review of patients undergoing vascular intervention between February 2010 and 2011 was performed. Patient chart examination included the analysis of consenting doctors' grade, responsible vascular consultant, completeness of procedural entry, documentation of correct side, use of abbreviations, discussion of benefits and complications, additional information and overall legibility. 323 patient consent forms were reviewed (male 203, mean age 68.0 years, elective surgery 241) including 50 AAA repairs, 27 carotid endarterectomies, 88 peripheral arterial reconstructions, 96 amputations and 69 elective varicose vein surgeries. 294 (91%) consent forms were completed by a specialist registrar or above with 286 (88.5%) forms having the responsible consultant documented. 85.4% of patients were consented within 48 h of surgery. 245 (75.9%) consent forms had legible printed names. However, only 75 (23.2%) had a legible signature. 306 (94.7%) consent forms had the procedure documented in full but 165 (51.0%) had used abbreviations. 103 (31.9%) had documentation of the intended benefits of surgery whilst 293 (90.7%) had documentation of potential complications. Three patients had documented evidence of receiving written information and one patient received a copy of the consent form. Of those surveyed, procedural mortality was discussed in 62.5% of open and 47.3% of endovascular AAA repairs. Stroke was documented in 96.3% of consent forms for carotid endarterectomy. Scarring was included most commonly in patients undergoing venous procedures. Vascular consent is a complex process involving a number of discussions and meetings with patients. Our unit has demonstrated compliance of nearly 90% for all consent-related processes and remains consistent with current GMC guidance. However, further improvement including the documentation of intended benefits, provision of additional written information whilst reducing the use of abbreviations is desired.

Peripheral arterial reconstruction in a patient with thalidomide embryopathy and chronic occlusion of the femoral artery

The constellation of genetic defects following prenatal exposure of the foetus to thalidomide constitutes the thalidomide embryopathy, characterized by typical malformations of the extremities. Thalidomide was a sedative that proved to be very effective against morning sickness and was consumed by many pregnant women in Europe in the 1950’s. Later on it became apparent that it was a very potent teratogenic factor that crossed the placental barrier and caused severe genetic birth defects to the foetus, affecting ~ 10.000 children. Today thalidomide is in use again as an effective treatment for a number of diseases like leprosy, multiple myeloma and pulmonary fibrosis. With many patients in Europe reaching maturity, as well as a number of new cases in Africa and South America, the effect of the syndrome is still present.

Comparison of Preserved Vascular Allografts Using Glycerol and University of Wisconsin Solution in a Goat Carotid Artery Transplantation Model

Background: Prosthetic grafts have poor patency rates in peripheral arterial reconstructions. Glycerol (GL)-preserved grafts are an alternative. The aim of this study was to examine patency, graft morphology and function of GL-preserved allografts in a goat carotid artery animal model. Methods: The first group (n = 7) underwent bilateral replacement of the carotid artery by a carotid allograft that was preserved in GL for 1 week. In the second group (n = 5), a carotid artery allograft that was preserved in University of Wisconsin solution (UW) for 48 h was used. In the third group (n = 5), the jugular vein (autologous vein, AU) was used. The follow-up was 3 months. Results: One UW graft and 1 GL graft occluded in the first 24 h postoperatively. Three-month primary patency rates for GL, UW and AU grafts were 93, 100 and 80%, respectively (p = 0.39). Graft diameter was increased in UW allografts (p < 0.005), whereas GL allografts remained unchanged. After explantation, GL allografts demonstrated contraction and relaxation capacity and lower intimal thickness (p < 0.001). Conclusion: GL preservation has proven to be a feasible method for arterial allograft transplantation in a large animal model with decreased intimal hyperplasia and renewed functional capability.

Early removal of chest tubes after lung resection -- VATS the reason?

diagnose whether it was aorto-iliac occlusive disease (Leriche syndrome) with significant collateralization or results from cardiac thrombus. However, the development of such a bypassing collateral vascular network obviously indicates it was not an acute aortic occlusion (AAO). The patient did not have a previous peripheral arterial reconstruction and atherosclerotic cardiac disease but suffered from rheumatic heart disease. Severe mitral valve stenosis was believed to be the cause of atrial fibrillation and thrombus in the left atrium. It must be pointed that the patient had cerebral embolism and acute left lower extremity which recovered after treatment 5 years ago, but no traumatic history, abdominal aortic aneurysms, and dyscinesia of both lower extremities. No anticoagulants were administrated during the past several years before being admitted to our hospital for cardiac surgery. We had no sufficient evidences to conclude that chronic atrial fibrillation is not associated with the infrarenal aortic occlusion. Perhaps we should objectively describe Fig. 2 as ‘occlusion of the infrarenal aorta and abundant collateral bypassing arteries between abdominal aorta and bilateral femoral artery.’ Luckily, the patient recovered well and remains healthy.

Reply to Zisis

We thank you Dr Zisis [1] for the comment on our article [2]. We reported a woman with rheumatic heart disease and atrial fibrillation. Computed tomography angiography (CTA) revealed a thrombus in the left atrium, occlusion in the infrarenal aorta and efficient development of collateral circulation of the epigastric arteries. Fig. 2 shows the occlusion suspected to be of embolic origin in the infrarenal aorta because we could not accurately diagnose whether it was aorto-iliac occlusive disease (Leriche syndrome) with significant collateralization or results from cardiac thrombus. However, the development of such a bypassing collateral vascular network obviously indicates it was not an acute aortic occlusion (AAO). The patient did not have a previous peripheral arterial reconstruction and atherosclerotic cardiac disease but suffered from rheumatic heart disease. Severe mitral valve

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.

Externally Supported, Noncoated, Knitted Dacron Graft and Gelatin-Coated Knitted Dacron Graft with Rings for Peripheral Arterial Reconstruction.

During the last 14 years, externally supported noncoated knitted Dacron grafts (EXS) and gelatin-coated knitted Dacron grafts with rings (GEL) were used in 176 patients for femoropopliteal bypass (F-P), femorofemoral bypass (F-F) and axillofemoral bypass (Ax-F). In the EXS group, 58 F-P above knee (ak), 42 below knee (bk), 25 F-F, and 19 Ax-F surgeries were performed. Twenty-three F-Pak, 5 F-Pbk, 26 F-F, and 8 Ax-F surgeries were performed in the GEL group. In the F-Pak, primary patency at 5 and 9 years was 75.5 and 53% for the EXS and that at 3 and 5 years was 75.0 and 60.0% for the GEL (n.s.). In the F-Pbk, primary patency at 5 and 10 years was 60.5 and 29.5% for the EXS, while patency at 1 year was 11.1% for the GEL (P < 0.05). In both the EXS and the GEL groups, the F-Pak surgery showed better outcomes than the F-Pbk surgery. The outcomes of the F-P grafts implanted into the legs with claudication were better than those performed for the limb salvage cases. Primary patency of the F-F and the Ax-F showed no differences and there were also no differences between the graft types. For F-Pak surgery, the EXS is the graft of choice. The GEL is not suitable for F-Pbk surgery. For F-F and Ax-F reconstruction, both the EXS and the GEL are acceptable.

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.

Prospective Evaluation of Ischemia in Brachial–Basilic and Forearm Prosthetic Arteriovenous Fistulas for Hemodialysis

Ischemia is a devastating complication after arteriovenous fistula (AVF) creation. When not timely corrected, it may lead to amputation. Symptomatic ischemia occurs in 3.7-5% of the hemodialysis population. Upper arm AVFs have a higher incidence of ischemia compared to forearm AVFs. As more patients may need upper arm AVFs in the growing and older hemodialysis population, occurrence of symptomatic ischemia may increase. The purpose of this study is to identify predictors for occurrence of ischemia. A prospective evaluation of ischemia was performed in patients randomised for either a brachial-basilic (BB-) AVF or a prosthetic forearm loop AVF. Clinical parameters, preoperative vessel diameters, access flows, digital blood pressures, digit-to-brachial indices (DBI) and interventions for ischemia were recorded. Sixty-one patients (BB-AVF 28) were studied. Seventeen patients (BB-AVF 8) developed ischemic symptoms. Six patients (BB-AVF 3) needed interventions for severe symptoms. Age, history of peripheral arterial reconstruction and radial artery volume flow were significant predictors for the occurrence of ischemia. Symptomatic ischemia occurred in 28% of patients with brachial-basilic and prosthetic forearm AVFs. Age, history of peripheral arterial reconstruction and radial artery volume flow might be important for prediction of ischemia.

Transforming growth factor-β1 antisense treatment of rat vein grafts reduces the accumulation of collagen and increases the accumulation of h-caldesmon

The main cause of occlusion and vein graft failure after peripheral and coronary arterial reconstruction is intimal hyperplasia. Transforming growth factor beta-1 (TGF-beta1) is a pleiotropic cytokine known to have powerful effects on cell growth, apoptosis, cell differentiation, and extracellular matrix synthesis. To investigate the role of TGF-beta1 in intimal hyperplasia, we used adenovirus to deliver to superficial epigastric vein messenger RNA (mRNA) antisense to TGF-beta1 (Ad-AST) or the sequence encoding the bioactive form of TGF-beta1 (Ad-BAT). Infection with "empty" virus was used as a control (Ad-CMVpLpA). The treated vein was then used for an interposition graft into rat femoral artery. Grafts were harvested at 1, 2, 4, and 12 weeks and formalin-fixed for histologic studies or placed in liquid nitrogen for mRNA studies. Ad-AST treatment resulted in an overall reduction of TGF-beta1 expression (P = .001), and Ad-BAT treatment resulted in an overall increase in TGF-beta1 expression (P = .007). Histologic analysis showed Ad-AST caused reduced collagen build up in the neointima at 12 weeks (P = .0001). Immunohistochemical staining for h-caldesmon at 12 weeks indicated Ad-AST increased smooth muscle cells throughout the vessel wall compared with Ad-CMVpLpA (P = .0024) or Ad-BAT (P = .04). Ad-AST also resulted in reduced CD68-positive cells in the media/adventitia (P = .005 vs Ad-CMVpLpA, P = .01 vs Ad-BAT). To further understand how Ad-AST was influencing the build up of collagen, we performed quantitative polymerase chain reaction on complimentary DNA (cDNA) from homogenates of the vein grafts. Tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) was increased at 1 week by Ad-BAT (P = .048 vs Ad-CMVpLpA) and decreased by Ad-AST at all time points (P </= .038). The mRNA for collagen-1 alpha-1 was decreased by Ad-AST at 2, 4, and 12 weeks (P < or = .05) and increased by Ad-BAT at 1 week (P = .01). TGF-beta1 antisense treatment of vein grafts prevents the accumulation of collagen in the neointima in part by (1) changing the proportions of the cell types populating the vein graft wall, (2) reducing the mRNA for TIMPs, and (3) reducing the amount of collagen mRNA. With the Ad-AST and Ad-BAT treatments, we have been able to tip the maturation of the vein graft toward positive remodeling (artery-like phenotype) or toward negative remodeling (fibroproliferation and stenosis), respectively.

Kostenanalyse verschiedener Bypassmaterialien in femoropoplitealer Position unter G-DRG-Bedingungen

The German DRG classification refrains from medical accuracy of different surgical procedures by concentrating mainly on economic aspects. The process cost calculation of femoropopliteal bypass should as an example illuminate the charge of a surgical procedure under hospital conditions. From 07/03 to 03/04 we analysed out of 71 peripheral arterial reconstructions 10 alloplastic grafts (PBP) and 10 autologous vein grafts (VBP) for femoropopliteal above-knee bypass through the process cost calculation. This required a classification of the procedure in different diagnostic and treatment sections (ward, intensive care, diagnosis, treatment (surgical procedure)). The average length of hospitalisation with VBP amounted to 12.2 +/- 3.6 (7-19) days, and with PBP to 14.0 +/- 8.0 (8-35) days. The duration of the surgical procedure was almost identical with 118 +/- 26 minutes (VBP) compared to 110 +/- 31 minutes (PBP), but in average 0.4 more assistants participated in VBP. One bleeding caused revision in VBP; one PBP led to extended length of hospitalisation because of wound complication. We diagnosed one asymptomatic bypass occlusion in VBP. The average total costs in VBP amounted to 4 368.10 euro (profit: 4 468.15 euro), in PBP to 5 069.50 euro (profit: 3 802.94 euro). The reconstruction of the superficial femoral artery with alloplastic or autologous vein graft is profitable in G-DRG. Although less medical staff in required in PBP the price of the prosthesis weakens the profit. The autologous vein graft shows furthermore a shorter length of hospitalisation. Further investigation into cost-effectiveness regarding long-term follow-up and patency rates could lead to consequences for the German health system.