We thank the Editor for giving us the opportunity to respond to the questions about our work1raised by Drs. Joana and Moeen Panni. Their suggestion that we should have included an additional group receiving a surgical incision plus bupivacaine infiltration is of interest. Less extensive surgery (i.e ., without incising the peritoneal cavity or dissecting around the splenic pedicle) could have resulted in less neuroinflammatory response and hence a shorter (or no) period of postoperative cognitive dysfunction; this contention is supported by clinical data showing that the incidence of postoperative cognitive dysfunction is lower after minor than after major surgical procedures.2
The possibility that removal of the spleen predisposes to infection is an important consideration because this organ can modulate the organism’s immune function, albeit much less in adults3; interestingly, removal of an injured spleen does not enhance infectious complications in multiorgan-injury patients.4Rats, in common with other rodents, are quite resistant to infective processes even after splenectomy complicated by fecal contamination.5During our study, we also did not observe clinical evidence of postoperative infection. Last, we do not believe that surgery-induced immobility could have contributed to the splenectomized rats’ inability to learn because it was their choice of arm entry and not the speed or distance traveled that was assessed.
*Chelsea and Westminster Hospital, Imperial College London, United Kingdom. firstname.lastname@example.org