Rutherford's 049: Graft Infection скачать в хорошем качестве

Rutherford's 049: Graft Infection

#VascularSurgery #GraftInfection #Biofilm #PerioperativeInfection #Bacteremia #GraftEntericFistula #Neuropathy #RenalComplications #RespiratoryComplications #RutherfordVascular This video from The Deep Dive series, referencing Rutherford’s Vascular Surgery and Endovascular Therapy 10th Edition, explores the critical and often devastating issue of vascular graft infections. While initially low risk (0.2% to 5% for open surgery), if an infection occurs, the consequences are severe. A foreign object like a graft lowers the body's defence, meaning fewer bacteria are needed to cause infection. Bacteria can reach the graft via four main pathways: perioperative contamination (during surgery, from skin, wound, or remote infection), bacteremia (bacteria in the bloodstream from remote sites like IVs, UTIs, foot wounds, or even dental work), mechanical erosion (especially aortic grafts rubbing into nearby organs like the bowel, creating a fistula), and contiguous spread from a nearby infection. Patient factors like malnutrition, cancer, kidney disease, suppressed immunity, and potentially diabetes increase risk. Once bacteria arrive, they stick more easily to materials like polyester (Dacron) than PTFE. Gram-positive bacteria like Staphylococcus produce a sticky layer (glycocalyx) aiding attachment. They form protective biofilms, which shield them from immune cells and antibiotics. This triggers inflammation, hindering healing and making the graft more vulnerable. Common culprits are Staphylococcus aureus (25-50%) and increasingly, biofilm-forming *Staphylococcus epidermidis*. Gram-negative bacteria like E. coli are dangerous due to toxins causing vessel wall damage and rupture risk. Antibiotic resistance, particularly MRSA, is a growing challenge, linked to increased prevalence and harder treatment. Diagnosis involves clinical signs (fever, unwell feeling for aortic grafts; redness, drainage, pseudoaneurysm for peripheral grafts). GI bleeding in a patient with an aortic graft is a critical sign of potential graft-bowel connection. Labs like white blood cell count and ESR can show inflammation but aren't specific. Blood cultures are often negative, especially in late biofilm infections. Imaging is crucial: CT scans are preferred for central grafts, showing inflammation, fluid/gas collections, and pseudoaneurysms. Ultrasound is useful for peripheral grafts, identifying fluid, pseudoaneurysms, and patency. MRI can distinguish fluid/scar tissue but gadolinium carries risk. Functional white blood cell scans can detect active infection but have limitations, especially early post-op. Endoscopy is key for suspected graft-enteric erosion/fistula. CT-guided aspiration helps sample fluid, but negative cultures don't rule out biofilm. Surgical exploration is often definitive. Culturing graft tissue (sonication/broth) is needed to detect slow-growing biofilm bacteria. Treatment goals are infection eradication and maintaining blood flow. Strategies depend on presentation, bacteria type, and infection extent. Options include graft preservation (rare, for limited early non-anastomotic infections), complete graft removal and extra-anatomic bypass (standard for severe infections, especially graft-bowel connection), or in-situ replacement (using patient's veins - NAS, donor arteries - allografts, or antibiotic-soaked prosthetics). In-situ vein grafts show promise with lower mortality/amputation but aren't for severe cases. Antibiotic-soaked prosthetics are used cautiously for localized low-grade infections. Adjuncts are vital: tailored IV antibiotics (broad spectrum initially), antibiotic-loaded beads for local delivery, and healthy tissue flaps (omentum, muscle) to cover grafts and fill space. Endograft infections are increasing and require similar complex management, often involving device removal. Long-term follow-up is essential. Managing these infections is complex, often requiring a multi-pronged approach tailored to the individual patient.