AP entry modification

Accounts Payable started a transaction in the AP module and saved the transaction due to its length and complexity in order to reach back out to the vendor to clear up an issue with the retention amount shown on their invoice. Before she saved the transaction she entered the word "gross" in the description line in each of the line items for the cost codes billed under that invoice to signify that those amounts pertained to the gross amount billed and to remind herself to not pay this until the issue was rectified. Once the retention amount was cleared up with the vendor, she went back in through "Edit invoice", changed the memo at the top to list the invoice number and modified the amount next to retention. Upon saving, she thought the description field listed next to each cost code would reflect the new description, but in fact, the description was only modified on the line item for retention. Is there a way, after this invoice has been paid to go back and modify the description listed next to each of these cost codes or is it stuck showing the word "gross"?