Comparison of prophylactic versus indicated stent exchange for malignant obstructive jaundice using computer modeling

Prophylactic stent exchanges in patients with malignant obstructive jaundice (MOJ) might avoid the potential morbidity of stent occlusion, but unnecessary procedures add costs and inconvenience. Utilizing a computer model, we performed a replacement analysis to study different stent exchange practices in patients with MOJ. Methods: Data from 338 patients with MOJ treated with stenting (≥ 1 OF Gauge) were used to calculate hazard rates for stent (occlusions) and patient (deaths) over time. Stents were exchanged (N=131) only when indicated for occlusion. Median stent and patient survival were 3.1 mo and 4.8 mo, respectively. Median stent survival was significantly longer for initial stents (3.5 mo) compared to subsequent stents (2.1 mo). All replacement stents (prophylactic and indicated) were modeled as indicated stents using the hazard rates obtained from stents replaced after stent occlusion. The model assumed no septic deaths. Results: The model-predicted number of exchanged stents (prophylactic and indicated) for different prophylactic exchange policies is tabulated below. Exchange Interval 3 mo 4 mo 6 mo 10 mo Total 474 407 310 239 # Prophylactic stents 244 179 95 32 # Indicated stents 230 228 215 207 Because replacement stents (after stent occlusion) failed earlier, the prophylactic exchange models generated more indicated stent exchanges compared to indicated exchanges only (N=131). This would result in a more costly approach at all cost estimates (even inexpensive prophylactic plus very expensive indicated exchanges). Conclusions: Using the assumptions above, computer modeling suggests that indicated stent exchanges are more cost-effective compared to prophylactic stent exchanges at any interval. Hazard rates for prophylactic exchanged stents would need to be used in the model to confirm this conclusion.