Transfusion via the carotid artery in the hamster.

Public health policy makers need quantitative scientific data to assess the risk to the blood supply posed by transmissible spongiform encephalopathy (TSE) diseases. To this end, our laboratory has developed a model of blood-borne TSE infectivity in hamsters infected with the 263K strain of scrapie, an experimental model of choice for quantitative studies of TSE infectivity. We report here a microsurgical method for cannulation of the carotid artery in the hamster that allows transfusion of a large fraction of the blood volume of the hamster, with virtually no blood loss to the surgical site or exposure to nervous tissue. Animals are minimally affected by the surgery, recover quickly and completely, and survive for their natural lives (as long as 3 years). This procedure has been used to obtain quantitative data on the transmissibility of the TSEs by transfusion, and these findings have informed public health policy on blood donation and blood use.

Femorofemoral bypass with femoral popliteal vein.

BACKGROUND: The femoropopliteal vein (FPV) has been used successfully for vascular reconstructions at multiple sites. To date, there have been no studies documenting patency of the FPV graft in the femorofemoral position. Our goal was to assess long-term patency of the FPV graft used for femorofemoral bypass (FFBP). METHODS: Patients undergoing FFBP over a 10-year period were studied. Those in whom the FPV was used as a conduit were analyzed for runoff resistance score to assess how patients with poor runoff fared. Poor runoff was defined as a runoff resistance score of > or =7 (1 = normal runoff, 10 = total occlusion of all runoff vessels). RESULTS: Fifty-four patients underwent FPV FFBP as a sole procedure (n = 16, 30%) or as a portion of an aortofemoral reconstruction with a FFBP component (n = 38, 70%). Mean (+/- SD) follow-up was 47 +/- 33 months. The 1-, 3-, and 5-year primary patencies were 97%, 93%, and 76%. The 5-year assisted primary and secondary patency rates were 85% and 90%. Among 27 patients with poor runoff (runoff resistance score of > or =7), the cumulative 40 month patency rate was 90%. Among patients in whom FPV FFBP was performed as a primary procedure (no aortofemoral component), there were no graft failures. CONCLUSIONS: FFBP performed with FPV has excellent 1-, 3, and 5-year patency rates. FPV has sustained patency for FFBP in patients with poor runoff.

Arterial reconstruction of infected femoral artery pseudoaneurysms using superficial femoral-popliteal vein.

BACKGROUND: Infected femoral artery pseudoaneurysms (IFAPs) secondary to percutaneous arterial access, injection of illegal substances, and from infected synthetic grafts, appear to be increasing in incidence. Ligation of IFAPs without revascularization offers control of infection but may risk limb ischemia. Revascularization with extraanatomic synthetic grafts may risk reinfection and abrupt thrombosis. Excision of IFAPs with revascularization using superficial femoral popliteal vein (SFPV) provides both control of infection and excellent limb perfusion. STUDY DESIGN: A retrospective review was conducted of patients diagnosed with IFAP who underwent resection and revascularization with SFPV at a single medical center. Outcomes measured included reinfection and amputation rate. These were compared with other series using various methods to treat IFAPs. RESULTS: Eleven patients with IFAP were encountered from 1992 to 2004. Mean age was 64 years (+/-10 SD). Five patients developed IFAP secondary to percutaneous arterial access procedures. Four patients developed infected femoral artery pseudoaneurysms secondary to synthetic graft infection. Two patients developed IFAP secondary to injection of illegal substances in the femoral region. All patients had positive wound cultures initially. Staphylococcus was the most common organism found in wound cultures. All patients underwent resection of IFAP with lower extremity revascularization using SFPV. There was no incidence of limb ischemia and no perioperative deaths in this series. CONCLUSIONS: Excision of IFAP with revascularization can be successfully achieved using SFPV. This method may prove to be superior to other methods with apparent higher patency rates and resistance to reinfection.

Aortofemoral bypass in young patients with premature atherosclerosis: is superficial femoral vein superior to Dacron?

PURPOSE: Previous studies have documented poor patency rates in "young" patients (age 55 years or younger) with premature atherosclerosis undergoing aortofemoral bypass (AFB) to treat aortoiliac occlusive disease. Given the high reported graft patency rates with superficial femoral vein (SFV) grafts performed because of aortic graft infection, we evaluated the role of SFV grafts for AFB as primary therapy for premature atherosclerosis in a case-control study. METHODS: Over 10 years 31 patients aged 55 year or younger underwent AFB with use of SFV (V-AFB). Case controls consisted of all patients 55 years of age or younger who underwent AFB with use of Dacron (D-AFB) during the same period (n = 80). In all cases this was the initial therapy (no repeat operations). The two groups were well matched for age, sex, weight, preoperative ankle-brachial index, and the comorbid conditions of smoking, coronary artery disease, chronic obstructive pulmonary disease, hyperlipidemia, hypertension, and renal insufficiency. There were more patients with diabetes in the V-AFB group (34% vs 16%; P =.05). Patients in the V-AFB group had more advanced disease, and the surgical indication was more frequently critical ischemia compared with the D-AFB group (90% vs 46%; P <.001). RESULTS: There was only one perioperative death in each group. There were no differences in cardiac, pulmonary, or gastrointestinal complications. However, fasciotomy occurred more frequently with V-AFB (44% vs 1%; P <.001). Surgery time was longer with V-AFB (7.3 vs 4.5 hours; P <.001). Despite these short-term drawbacks, V-AFB proved superior at long-term follow-up. The 5-year primary patency rate was significantly higher with V-AFB than with D-AFB (100% vs 56%; P =.013). There was also a trend for higher limb salvage at 5 years (90% vs 62%). Four graft infections occurred with D-AFB, and none with V-AFB (P =.32). CONCLUSIONS: AFB performed with SFV grafts is a far more durable operation than standard D-AFB in young patients with aortoiliac occlusive disease. However, V-AFB is far more likely to require lower extremity fasciotomy, and takes almost twice as long to perform.

Epidermal growth factor-stimulated rabbit oesophageal mucosal growth: Role of polyamines.

Factors operative in oesophageal mucosal growth are poorly characterized. Epidermal growth factor (EGF) has been shown to stimulate mucosal growth throughout the gastrointestinal tract. The present study was performed to test the hypothesis that polyamine biosynthesis is required for stimulation of epithelial growth by EGF in oesophageal mucosa. Using an in vitro explant model, oesophageal mucosal growth was quantified in the presence or absence of EGF and α-difluoromethylornithine (DFMO), a specific inhibitor of polyamine synthesis. Administration of 50 nmol/L EGF significantly increased the rate of epithelial growth in oesophageal explants. Treatment with DFMO for 3 and 7 days not only depleted the tissue polyamines putrescine, spermidine and spermine, but also significantly impaired mucosal growth. The inhibitory effect of DFMO on mucosal growth was partially but significantly prevented when exogenous putrescine was given. Additionally, stimulation of epithelial growth by EGF was also blocked by depletion of cellular polyamines in DFMO-treated oesophageal explants. These results indicate that EGF stimulates epithelial growth of oesophageal mucosa at least partly through a process involving polyamine biosynthesis.