Cognitive changes after surgery in the elderly: does minimally invasive surgery influence the incidence of...

Postoperative delirium in the elderly is a growing concern. Data regarding significant differences in postoperative cognitive dysfunction (POCD) in elderly persons undergoing laparoscopic versus open colon resection are not well established.

The goal of this study was to compare the incidence of POCD in laparoscopic versus open colon surgery in an elderly population.

A prospective nonrandomized pilot study was conducted at an urban tertiary care hospital.

The study included patients aged 65 years and above, without documented dementia who underwent elective colon surgery.

We collected demographic and clinical data, including age, sex, polypharmacy, and comorbidities. The subjects underwent pre- and postoperative Cambridge Neuropsychological Test Automated Battery (CANTAB) testing. Worsening individual scores from the Paired Associated Learning (PAL) and Spatial Working Memory (SWM) portions of CANTAB determined the presence of POCD. Inflammatory cytokine (i.e., IL-6) levels were measured pre- and postoperatively.

We enrolled 44 subjects (26 laparoscopic and 18 open surgery). The two groups did not differ significantly in age, sex, polypharmacy, and comorbidities. The average incidence of POCD was 47%. PAL scores worsened in 12/23 (52%) in the laparoscopic group and in 7/15 (47%) in the open group. These group differences lacked statistical significance (p = 0.75). SWM scores worsened in 14/25 (56%) in the laparoscopic group and in 6/18 (33%) in the open group, which was also not statistically significant (p = 0.12). No age difference occurred between the 'worsened scores' group and 'stable scores' group, and older age was not associated with POCD. IL-6 levels were higher in the open versus the laparoscopic group (p < 0.0001).

In this pilot study, the average incidence of POCD was not statistically different between elderly subjects undergoing open versus laparoscopic surgery. Age did not influence the occurrence of POCD. Although inflammatory markers were significantly higher in the open group, consistent with a higher degree of stress response, this group did not have higher rates of delirium. This association is worth to be investigated in a larger sample.