Does Secondary Ischemia Time After Failed Digit Replantation Predict Survival?

Early identification of vascular compromise following digit replantation and revascularization, and prompt restoration of blood flow is considered critical for successful salvage. This study aimed to assess the duration of secondary ischemia in replanted and revascularized digits with postoperative arterial insufficiency that were reoperated on and to determine whether there is a correlation between secondary ischemia time and digit survival.

We identified replanted and revascularized digits reoperated for isolated arterial thrombosis during their primary admission at the National Unit for Replantation Surgery in Norway from 2010 to 2024. Ischemia onset was defined as a decrease in surface skin temperature of 1 °C per hour or 1.5 °C over 2 hours. Data on the onset of ischemia, time to reestablishment of arterial circulation, and survival were extracted from the unit's internal quality registry. Well-known predictors for survival following digit replantation were also assessed to control for confounding variables. We conducted binary logistic regression and compared the means of secondary ischemia time between the survival and nonsurvival groups with a t test.

A total of 59 digits with vascular compromise were reoperated for isolated arterial thrombosis. Logistic regression did not identify secondary ischemia time as a predictor for survival. The average secondary ischemia time for salvaged digits compared with nonsalvaged digits was not different. The survival and nonsurvival groups were similar regarding confounding variables.

Digit replantations that undergo postoperative ischemia due to arterial occlusion may tolerate longer secondary ischemia times than previously assumed. Our study did not demonstrate secondary ischemia due to arterial thrombosis as a critical predictor for salvage. Evidence of a critical secondary ischemia threshold is still lacking.

This study may support a more nuanced urgency in re-exploration decisions after digit replantations with postoperative arterial insufficiencies. Delayed recognition of arterial insufficiency can still result in successful salvage.