The text on this page is taken from an informal compilation of opinions of contributors to the online VOLE List. As such, they are not peer reviewed and may contain differences of opinion. Those wishing to contact the list may contact Adrian Smith.
Could I ask people's experience of the need to remove minipumps, please. I have a group working with aged mice who need to maintain the mice for 58 days after implant of the minipump and the recommended length of time to leave it in place from Alzet is only 42 days. We would prefer to avoid a second surgery for these mice if possible without adverse effects. Any information from the group on experiences of leaving minipumps in place for longer would be appreciated, or tips to assist recovery in aged mice as I would assume the chance of seroma formation post-operatively in these mice is going to be high.
From what I understand, the suppliers recommend removing them, as pump chemicals can eventually seep out. My suggestion would be to contact the specific supplier (eg. ALZET reps can provide bibliography too and how long it might still be safe).
Another point to consider: the pumps don’t stop delivering the solution after the 2-4-6 weeks. The optimal constant rate of delivery happens within the recommended time frame, but there will be a gradual increase before, and a decrease after. Therefore, extending the delivery period means that you may not know the true dosage.
I am sure you also thought of making sure the PPL includes this step (removal/replacement), as PILs may wrongly assume it’s “part of the model”.