Fistula-first choice with conversion arithmetic, maturation pricing with anaesthesia lever, and steal graded to DRIL

Model answer

(A) The 64-year-old starting on a catheter — hierarchy, conversion, decision, cost, honesty (4 marks). Rank fistula over graft over catheter: pooled mortality 1.53 catheter and 1.18 graft against fistula with fatal infection 2.12/1.36 — CHOICE splitting annual death 11.7/14.2/16.1% with adjusted 1.5/1.2 — Scotland confirming catheter-only mortality 1.83-2.08 with septicaemia odds 6.9-fold.^[1][2][4] Convert deliberately: DOPPS starts 69.2/17.6/13.1% with 22% permanent-access failure and 59% catheter-to-permanent conversion — conversion to permanent cuts mortality hazard to 0.69 while reversal raises it to 1.81.^[3] Decide by phenotype: fistula-attempt wins most groups especially younger non-diabetic men, ties in diabetic women and elderly diabetic men — cost-effective while maturation exceeds 36% ($9389/QALY) and dominant above 69%.^[7][8] Confess randomisation: no completed catheter-versus-fistula efficacy trial exists — the pilot in 55-plus shows no harm signal with most outcomes favouring catheters and strong preferences deciding jointly.^[6]

(B) The 78-year-old with small veins — predictors, rates, imaging honesty, block lever (3 marks). Predict first: stroke history, age and dialysis dependence lower odds; female sex, small vessels, low albumin, diabetes and low pressures predict early failure; Dutch flags add vascular disease with veins below 2.5 mm.^[16][20][17] Rate nationally: 36.2% never used with 54.7% working by 4 months; prospective maturation 55.5%; HFM 88.6% overall with coordinators doubling unassisted odds — while elderly fistulas trade early failure (51 vs 45%) for fewer infections and deaths, and 75-plus forearm builds fail twice as often as upper-arm.^{[18][16][19][12][15]} Image honestly and block regionally: 4 small trials show mapping changes neither creation nor maturation — but plexus block lifts 3-month patency 62 to 84% (OR 3.3), holds 79 vs 59% at 12 months with £195 saved, pooled at 12 vs 36 failures (OR 0.28).^{[22][59][60][61]}

(C) The painful pale brachial hand — recognise, grade, treat by preservation (3 marks). Recognise steal: up to 10% of creations, brachial origin in 87% of treated episodes, women and diabetes dominant, CAD/hypertension/tobacco as risks.^[37][33][34] Grade severity: grade-2/3 split evenly; severe grade-3 is tissue loss 61% over rest pain 39% with diabetes 86%.^[33][35] Treat by preservation: ligation 0%, DRIL 100%, RUDI 95%, banding 89% — improvement 98% DRIL vs 75% banding with 62% banding failure — RUDI matching DRIL on patency — arm-vein conduit matching saphenous with wounds 11 vs 46% — and 5-to-6 mm anastomoses abolishing steal (0 vs 9%) for future builds.^{[33][34][35][36][37]}