What is the management plan for a patient with a history of renal failure or end-stage renal disease (ESRD) and dialysis, presenting with an arteriovenous graft (AVG) and no detectable bruit, along with hypertension (elevated blood pressure)?

Urgent Evaluation and Management of AVG with Absent Bruit

Ang AVG na walang bruit ay isang emergency na nangangailangan ng agarang aksyon dahil ito ay mataas na nagsusuggest ng thrombosis, na siyang pangunahing sanhi ng access failure at potensyal na permanenteng pagkawala ng access.

Kaagad na Clinical Assessment

Ang physical examination ay kritikal na monitoring tool para sa AVG function. Ang access flow ay tumutukoy sa characteristics ng pulse, thrill, at bruit 1:

• Palpable thrill sa arterial, mid, at venous segments ng graft ay nagpapahiwatig ng flow na ≥450 mL/min 1
• Pulse lamang (walang thrill) ay nagmumungkahi ng mas mababang flow 1
• Walang bruit o thrill ay mataas na predictive ng thrombosis o severe stenosis 1

Dapat agad na suriin ang patient para sa:

• Swelling ng graft arm 1
• Prolonged bleeding post-dialysis 2
• Signs ng infection (purulent drainage, erythema, systemic fever) 3

Immediate Diagnostic Workup

Kailangan ng urgent referral para sa venography/angiography dahil ang absent bruit ay highly suggestive ng hemodynamically significant stenosis o thrombosis 1.

Ang thrombotic events ay resulta primarily ng progressive venous outflow stenosis, na sanhi ng intimal at fibromuscular hyperplasia sa venous outflow tract, typically sa vein-graft anastomosis 1. Approximately 90% ng thrombosed grafts ay may associated stenosis, predominantly sa outflow 1.

Management Algorithm

Kung Confirmed Thrombosis:

Endovascular o surgical thrombectomy dapat gawin within 48 hours para sa optimal outcomes 1, 4:

1. Percutaneous transluminal angioplasty (PTA) para sa underlying stenosis 1
2. Surgical thrombectomy kung endovascular approach ay hindi successful 4
3. Correction ng stenosis - failure na mag-increase ng access flow by at least 20% after intervention ay nagpapahiwatig ng unsuccessful correction 1

Kung May Stenosis Without Complete Thrombosis:

Preemptive treatment ng hemodynamically significant stenosis (≥50% reduction in vessel diameter with clinical abnormality) ay dapat gawin para prevent thrombosis 1:

• PTA o surgical repair ay nakakapag-maintain ng functionality at nakakapag-delay ng thrombosis 1
• Grafts with access flow <600 mL/min ay may higher rate ng thrombosis 1

Blood Pressure Management

Ang BP na 156/70 mmHg ay elevated at kailangan ng treatment, lalo na sa ESRD patients. Target BP ay dapat ≤130/80 mmHg para sa patients with chronic kidney disease 1:

• Combination therapy ay usually necessary 1
• Monitor serum creatinine at potassium 1-2 weeks after initiation o escalation ng ACEIs o ARBs 1

• 1 mg/dL increase sa creatinine ay dapat mag-raise ng suspicion para sa renal artery stenosis 1

Critical Pitfalls to Avoid

Huwag mag-delay ng referral - ang thrombosed grafts na hindi agad na-treat ay may significantly lower patency rates (33-63%) compared sa preemptive treatment ng stenosis (71-85%) 1.

Huwag mag-cannulate ng graft hanggang confirmed na patent at functional 1.

Monitor for infection - kung may signs ng systemic sepsis, purulent drainage, o abscess formation, kailangan ng urgent surgical exploration at possible graft removal with antibiotics 3.

Surveillance Moving Forward

Kung successfully treated, establish regular monitoring protocol 2:

• Dynamic venous pressure monitoring at blood flow rate of 200 mL/min during each HD session 2
• VP ≥140 mmHg in 3 of 6 consecutive readings warrants repeat angiography 2
• Recirculation >15% on two observations 2
• Patient education on daily palpation for thrill/pulse 1

Ang primary patency ng AVG ay 42% at 1 year at 20% at 2 years, kaya aggressive surveillance at early intervention ay essential para sa graft survival 5.