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F W LoGerfo

Publications and source records attributed to F W LoGerfo.

At least 73 records · Page 4Linked to original sources
PubMed1993

Application of the quinolone antibiotic ciprofloxacin to Dacron utilizing textile dyeing technology.

Prosthetic arterial graft infection continues to be a significant and often devastating complication of vascular surgery. The organisms Staphylococcus aureus (S. aureus) and Staphylococcus epidermidis (S. epidermidis) are the primary pathogens causing acute and late graft infections, respectively. The objective of this study was to develop an infection-resistant prosthetic arterial graft by applying the bacteriocidal quinolone antibiotic ciprofloxacin to polyethylene terepthalate (Dacron) via thermofixation (pad/heat), a new application method founded on established textile procedures. We hypothesize that the limited fibrophilic characteristics of ciprofloxacin will permit binding to Dacron and at the same time allow persistent controlled release over an extended period of time. Using pad/heat technology, 33 micrograms (+/- 2.97 micrograms, n = 12) of ciprofloxacin was successfully bound to a 1-cm2 piece of woven Dacron. A full complement of microbiologic assays demonstrated superior, sustained antistaphylococcal activity of the pad/heat Dacron when compared to Dacron dipped into an equivalent concentration of ciprofloxacin. The sustained antimicrobial efficacy of ciprofloxacin pad/heat-treated Dacron opens new avenues in the development of infection-resistant biomaterials based on an understanding of textile chemistry.

Blood Vessel Prosthesis↗
PubMed1993

In vivo testing of an infection-resistant vascular graft material.

Present prosthetic arterial conduits continue to suffer the clinically and economically catastrophic complication of infection. We recently described a novel technique for binding quinolone antibiotics to Dacron based on principles of textile chemistry. This thermofixation procedure ("pad/heat") utilizes the limited fibrophilic characteristics of the quinolone antibiotic ciprofloxacin (Cipro) to permit pad/heat application and allowed controlled, sustained release from Dacron in several in vitro assays. The objective of this study was to test this infection-resistant prosthetic vascular graft material in an in vivo model. Dacron segments (1 cm2, either plain, dipped into antibiotic immediately prior to implantation, or Cipro pad/heat treated) were implanted in the dorsal subcutaneous tissue of the rabbit and directly contaminated with 10(6) Staphylococcus aureus. After 1 week, the samples were sterily harvested. Wounds were blindly graded on a scale from 1 (no evidence of infection, good tissue incorporation) to 4 (suppurative infection extending outside of the graft pocket, no gross tissue incorporation). Plain Dacron was easily infected in this model (mean grade 3.1 +/- 0.6, 92% culture positive). Notably, however, a significant (P < 0.05) wound grade difference between the dipped (2.3 +/- 1.0) and pad/heat (1.4 +/- 0.6) samples was demonstrated. Determination of adherent bacteria present on the implanted Dacron pieces by sonication and culture studies again revealed a significant difference between the dipped (56% culture positive) and pad/heat (12% culture) groups (P < 0.025). Histologic studies confirmed good tissue incorporation of the pad/heat samples. This project opens new avenues in the development of infection-resistant biomaterials.

Animals↗
PubMed1993

Angioscopically directed interventions improve arm vein bypass grafts.

PURPOSE: Our purpose was to determine the incidence and segmental distribution of intraluminal disease in the arm veins of patients in whom saphenous vein was unavailable or inadequate for bypass, determine whether angioscopic evaluation and directed interventions can upgrade the quality of arm vein conduit and improve early graft patency, and describe the angioscopic technique of in situ retrograde arm vein inspection. METHODS: Retrospective review of 109 infrainguinal arm vein bypass grafts in 104 patients performed with intraoperative angioscopic vein preparation and monitoring between August 1989 and March 1992 was undertaken. Four additional arm veins harvested were discarded because of diffuse disease. RESULTS: Intraluminal disease was noted in 71 (62.8%) of 113 arm veins, "webs" in 61 (54%), vein sclerosis in 25 (22.1%), localized stenosis in 11 (9.7%), and thrombus in 7 (6.2%). Intraluminal disease was most common in the cephalic (forearm 49.2%; arm 35.1%) and median cubital (33.3%) veins and least common in the basilic vein (11.7%). Eighty-three angioscopically directed interventions in 68 of 71 abnormal arm veins resulted in upgraded vein conduit quality in 47 (66.1%) of 71. Primary patency (< 30 days) was 99 (90.8%) of the 109 grafts, 85 (95.5%) of 89 grafts with normal or upgraded quality conduits, and 14 (70%) of 20 inferior-quality grafts (p = 0.0024). These differences persisted through 1 year by life-table analysis, (p < 0.001). CONCLUSIONS: Not only is the routine use of the angioscope in arm vein bypass grafting a sensitive technique to detect the intraluminal diseases so prevalent in arm veins but it can also direct endoluminal and surgical interventions that upgrade the quality of the vein conduit and improve early graft patency.

Adult↗
PubMed1993

Salvaging the ischemic transmetatarsal amputation through distal arterial reconstruction.

From 1982 to 1991, 17 patients underwent a lower extremity arterial bypass to salvage an ischemic transmetatarsal amputation at the New England Deaconess Hospital. Eleven patients were male, and 16 had diabetes for an average of 29 years. The mean age was 71 years. Twelve patients presented with an ischemic ulcer, one had rest pain, and four underwent bypass for failure to heal a transmetatarsal amputation. Twelve patients presented with findings of secondary infection. All 17 patients underwent successful lower extremity bypass procedures to a variety of outflow vessels. Thirteen bypasses were to infrapopliteal arteries, including four to the dorsalis pedis artery. There were no perioperative deaths and all patients were discharged with patent grafts and healing limbs. Actuarial graft patency of the 14 vein grafts was 90% at 2 years. Actuarial limb salvage for the entire group was 93% at 2 years. Thirteen of the 14 patients who maintained patent grafts and healed their transmetatarsal amputations were ambulatory at their last known follow-up examination. Ischemic complications of previously created transmetatarsal amputations are uncommon. However, limb salvage attempts by lower extremity arterial bypass have a high likelihood of success. Major amputation in these patients should not be done without having first undergone a comprehensive vascular evaluation.

Aged↗
PubMed1993

Glycoconjugate mediated endothelial cell adhesion to Dacron polyester film.

PURPOSE: The purpose of this study was to explore new strategies for enhancing specific cell type attachment to biomaterials using immobilized lectins for cell surface glycoconjugates. The lectin Ulex europaeus I (UEA I) has a high affinity for human vascular endothelial cell surface glycoconjugates. METHODS: UEA I was covalently bound to polyethylene terephthalate (Dacron) with the cross-linking agent 1-ethyl-3-(dimethylaminopropyl)carbodiimide hydrochloride to achieve oligosaccharide-mediated endothelial cell attachment to this otherwise nonadherent surface. RESULTS: Experiments with radiolabeled UEA I demonstrated covalent linkage of as much as 1.35 micrograms/cm2. The lectin binding site is available after the reaction, as demonstrated in experiments a neoglycoprotein. Adhesion studies reveal a 100-fold increase in endothelial cell attachment for the UEA I/polyethylene terephthalate surface (99.7 +/- 29.6 cells/high-power field) when compared with untreated (0.7 +/- 0.5), crosslinking agent (0.4 +/- 0.3), and denatured UEA I (1.2 +/- 1.1) control groups. Five vascular endothelial cell lines adhered to the UEA I/polyethylene terephthalate surface, whereas monocytes, smooth muscle cells, and fibroblasts did not. CONCLUSION: These results imply new strategies for endothelialization of prosthetic grafts and promotion of selective cell adherence to biomaterials, with emphasis on carbohydrate interactions. Moreover, this experimental system offers a model for exploring the biologic significance of the endothelial cell-UEA I ligand.

Cell Adhesion↗
PubMed1992

Trends in the care of the diabetic foot. Expanded role of arterial reconstruction.

In recent years, our operative approach to ulceration and gangrene in the diabetic foot has changed markedly. We now investigate all such patients for ischemia, even in the presence of neuropathy and localized infection. This strategy is based on a rejection of the concept of a microvascular occlusive lesion, an improved understanding of the pattern of atherosclerotic occlusion, an emphasis on arteriographic delineation of the foot arteries, and increasing success with extreme distal arterial reconstruction, especially vein bypass grafts to the dorsalis pedis artery. From 1984 through 1990, 2883 procedures were performed at our institution on patients with diabetes mellitus. There was a statistically significant decrease in every category of amputation, which correlated precisely with the increasing rate of dorsalis pedis artery bypass. Our indications for surgery, in-hospital mortality, and the bypass-associated amputation rate did not change.

Amputation, Surgical↗
PubMed1992

Disruption of proximal axillobifemoral bypass graft anastomosis.

Anastomotic disruption of axillobifemoral bypass grafts is a rare but serious complication. Previously described causes of anastomotic disruption include the following: infection, technical errors, and severe mechanical stress. In this report we describe a proximal anastomotic disruption of an axillobifemoral bypass graft in which the suture line remained intact on the axillary artery and tore through the polytetrafluoroethylene graft. This suggests a possible role of material failure contributing to axillobifemoral anastomotic disruption.

Aged↗
PubMed1992

Prevention of smooth muscle cell phenotypic modulation in vein grafts: a histomorphometric study.

This is a prospective study of the relationship between graft preparation technique and the subsequent morphologic fate of vein grafts. Paired vein grafts (optimal vs injury prepared) were placed in a canine model and removed over time. Vein grafts intentionally injured by warm saline storage demonstrated endothelial and smooth muscle cell damage. In the acute postimplantation period, platelet adhesion and white cell infiltration of the graft were present. By 7 days, the endothelium had "healed", but the underlying smooth muscle cells had modulated and were of the transitional or synthetic phenotype. This persisted at 30 days, but by 60 days the graft wall had remodeled to a contractile smooth muscle cell phenotype. Changes in the extracellular matrix were greatest at 30 days corresponding to changes in the smooth muscle cell phenotype. None of these injurious responses were noted in optimally prepared, papaverine treated vein grafts. The combined intima and media (lumen to adventitial edge) was measured at baseline and at graft excision with use of digitized graphic techniques. The intimal/medial thickness of injured vein graft walls was always greater than that of pair-matched optimally treated vein grafts (p less than 0.01 analysis of variance). Optimal preparation of vein grafts is effective in minimizing endothelial and smooth muscle cell injury at the time of arterial reconstruction. This preservation of endothelial and smooth muscle cell integrity prevents subsequent morphologic changes associated with the "arterialization response".

Analysis of Variance↗
PubMed1992

Qualitative microscopy of implanted vein grafts. Effects of graft integrity on morphologic fate.

This is an investigation of the relationship between graft preparation techniques and the subsequent fate of vein grafts. Vein grafts intentionally injured by warm saline storage demonstrated endothelial and smooth muscle cell damage. In the acute postimplantation period, platelet adhesion/activation and white cell infiltration were present. By 7 days the endothelium had "healed," but the underlying smooth muscle cells had modulated and were of the synthetic phenotype. This persisted at 30 days, but by 60 days the graft wall remodeled with smooth muscle cells that were of the contractile phenotype, with an organized extracellular matrix. None of these injurious responses were noted in optimally prepared papaverine-treated vein grafts. Optimal preparation of vein grafts is effective in minimizing endothelial and smooth muscle cell injury before and after arterial reconstruction. Prevention of vein graft injury during harvesting prevents the morphologic changes characteristic of the "arterialization response."

Animals↗
PubMed1992

Safety of vein bypass grafting to the dorsal pedal artery in diabetic patients with foot infections.

The results of 56 vein bypasses to the dorsal pedal artery performed in 53 diabetic patients who were admitted with ischemic foot lesions complicated by infection were reviewed. All patients had one or more of the following: infected ulcers (73%), cellulitis (45%), osteomyelitis (29%), gangrene (20%), or abscess (2%). Organisms were cultured from 84% of patients (average 2.6, range 1 to 9 organisms per infection). Elevated temperature (greater than 37.7 degrees C) or leukocytosis (greater than 9.0 x 10(3)/ml) were seen in 13% and 50% of patients, respectively. All patients were treated with broad-spectrum antibiotics, local debridement, wound care, and bed rest. Operative debridement or open partial forefoot amputation were required to control sepsis in 11 patients (20%). Treatment of infection delayed revascularization by an average of 10.7 days. All patients underwent autogenous vein bypasses to the dorsal pedal artery. Two grafts failed within 30 days (3.6%), and one patient died (1.8%). Wound infections developed in seven patients (12.5). One wound infection resulted in graft disruption and patient death at 2 months. Average length of stay of the initial hospitalization was 29.8 days. Fifty-two patients were discharged with patent grafts and salvaged limbs; however, 31 subsequent foot procedures and 35 rehospitalizations were required to ultimately achieve foot healing. Actuarial graft patency and limb salvage were 92% and 98%, respectively at 36 months. Pedal bypass to the ischemic infected foot is efficacious and safe as long as infection is adequately controlled first. The complexity of these situations often requires multiple surgical procedures and extensive wound care, resulting in prolonged or multiple hospitalizations.

Actuarial Analysis↗
PubMed1992

Peripheral vascular bypass in juvenile-onset diabetes mellitus: are aggressive revascularization attempts justified?

This study was performed to evaluate the results of peripheral vascular reconstruction for arterial occlusive disease in patients with juvenile-onset diabetes mellitus. The results of 67 bypass procedures performed on 60 patients with juvenile-onset diabetes mellitus between Jan. 1, 1984 and Dec. 31, 1989, were reviewed. These patients had a mean age of 44.4 years (range, 29 to 59 years), with an average age of onset of diabetes mellitus of 9.8 years (range, 1 to 19 years). These procedures comprised 5.5% (67 to 1214) of the bypasses performed on diabetic patients during the same time period at a single institution. Fifty-four of 67 (91%) procedures were performed for limb salvage. Fifty-four (81%) procedures were primary infrainguinal bypasses with saphenous vein (femoropopliteal 19, femorodistal or popliteal-distal 35). Six procedures (9%) were revision procedures, four (6%) were in-flow procedures, and three (4%) were infrainguinal procedures with polytetrafluoroethylene. Thirty-day morbidity and mortality rates were 31% and 0%, respectively. Actuarial patency and limb salvage rates of the primary vein graft group were 66.0% (+/- 10.7) and 83.4% (+/- 8.0%), respectively, at 24 months. Cumulative survival of the entire group at 2 years was 84.1%. Although follow-up in this study is relatively short (24 months), the results suggest that the outcome of vascular reconstruction in patients with juvenile-onset diabetes mellitus is acceptable when compared with procedures performed in adult-onset diabetic and nondiabetic populations. The presence of juvenile-onset diabetes mellitus should not diminish the vascular surgeon's expectations of a successful outcome when considering lower extremity revascularization in these patients.

Actuarial Analysis↗
PubMed1991

A flexible approach to infrapopliteal vein grafts in patients with diabetes mellitus.

From October 1985 to August 1989, we performed 156 dorsalis pedis artery bypasses in 146 patients, 139 (95%) of whom had diabetes mellitus. A variety of surgical techniques were used to shorten surgery, limit incision length, and optimize size-matching between vein grafts and arteries whenever possible. Arterial inflow was from the common femoral artery in 58 cases, from the distal superficial femoral or popliteal artery in 88 cases, from a tibial artery in three cases, and from a preexisting bypass in seven cases. In situ (75 cases), ex situ reversed- or nonreversed-vein (62), composite vein (nine), and polytetrafluoroethylene (one) bypasses were constructed. Four patients (2.7%) died, and seven grafts (4.5%) failed within 30 days. Actuarial patency and limb salvage 6 to 52 months after surgery were 87.1% and 91.6%, respectively. There were no significant differences in patency between in situ and ex situ vein grafts (93.2% vs 89.7%) or between common femoral artery inflow site and distal superficial femoral/popliteal artery inflow site (89.3% vs 88%).

Actuarial Analysis↗
PubMed1991

A new canine model for evaluating blood prosthetic arterial graft interactions.

Various models have been proposed to examine blood-prosthetic materials interactions in terms of the effect of the prosthetic material on platelet structure and function, blood coagulation and fibrinolysis, and tissue infiltrates (cellular or acellular). In addition, these models have been used to examine the change in the graft surface over time. Particular difficulties in examining graft-materials interactions include species differences, short residence time for blood-materials interactions with commonly employed short grafts, and length of study limitations with ex vivo shunts. In this paper we report a canine, carotid-aorta subcutaneous prosthetic graft model. The specific advantages of this model are the length of the graft, which allows prolonged contact of blood with the prosthetic surface; the subcutaneous location of the graft, which allows repeated sampling of blood along the graft; and the healing characteristics of canine grafts. We selected the canine model because the healing characteristics are morphologically similar to those in humans in that endothelialization of the prosthetic surface is limited. Other models, such as the pig, are favored for use when examining blood coagulation, platelet, or fibrinolytic studies; however, these models can fully endothelialize prosthetic surfaces.

Animals↗
PubMed1991

Angioscopy of arm vein infrainguinal bypass grafts.

Between January 1988 and December 1990, 56 patients underwent 66 arm vein infrainguinal bypass grafts for limb salvage. Thirty-nine grafts were intraoperatively monitored by the standard methods of continuous wave Doppler alone (30) and arteriography (9). Twenty-seven grafts were prepared and monitored by intraoperative angioscopy. No significant findings requiring intraoperative revision or correction were noted in the grafts monitored by the standard methods. However, in those grafts prepared and monitored by angioscopy, intraluminal abnormalities of the arm veins were detected and corrected in 20/27 (74%). None of the grafts prepared or monitored by angioscopy occluded within 30 days, whereas, in those grafts monitored by continuous wave Doppler and arteriography, 7/39 failed within 30 days, a primary patency rate of 32/39 (82%) (x2 with yates correction, p = 0.055). This study shows that angioscopic preparation and monitoring of arm vein bypass grafts allows the detection and correction of unsuspected intraluminal abnormalities, which appears to improve the early primary patency of arm vein infrainguinal bypass grafts.

Aged↗