If you can't fix the problem using Excel Find & Replace, which is where I would start if I had Excel, can you import every sheet, fix the column names and then select the columns you want? The work flow would look something like the following except that I only fixed two columns.
library(dplyr, warn.conflicts = FALSE)
library(stringr)
DF <- data.frame(DOB = 1:4, NotGood = 2:5, OP = 1:4)
DF
#> DOB NotGood OP
#> 1 1 2 1
#> 2 2 3 2
#> 3 3 4 3
#> 4 4 5 4
NMS <- colnames(DF)
NMS <- str_replace(NMS, "Birth|DOB|Date of Birth", "DateOfBirth")
NMS <- str_replace(NMS, "Operation|Procedure|OP", "Oper")
colnames(DF) <- NMS
DF <- select(DF, DateOfBirth, Oper)
DF
#> DateOfBirth Oper
#> 1 1 1
#> 2 2 2
#> 3 3 3
#> 4 4 4
Created on 2021-03-24 by the reprex package (v0.3.0)