Risk Factors for Abdominal Incision Infection after Colorectal Surgery in a Saudi Arabian Population: The Method of Surveillance Matters.

BACKGROUND: Reported surgical site infection rates range from 2.1% to 40% after colorectal surgery and are believed to be underestimated depending on the method of surveillance. The study aims were to identify an accurate incidence and associated risk factors for abdominal incision surgical site infection after elective open colorectal surgery in a Saudi population. METHODS: This was a prospective observational longitudinal study of 300 consecutive adult patients, recruited upon admission to an 800-bed tertiary referral center. All consenting adults admitted for elective open colorectal surgery were included. Patients were followed for 36 d post-surgery by two certified and experienced wound care experts who diagnosed abdominal incision surgical site infections. The definition provided by the U.S. Centers for Disease Control and Prevention was used. Statistical analysis was performed using both univariate and multivariable logistic regression. RESULTS: Data were analyzed for 296 patients; the incidence of abdominal surgical site infection was 30%. Factors associated with surgical site infection by univariate analysis were pre-operative pre-albumin (p=0.04, odds ratio [OR] 0.81, 95% confidence interval [CI] 0.66-0.99); operative difficulty because of truncal obesity (p=0.006, OR 2.19, 95% CI 1.25-3.84) and obesity measured by body mass index (p=0.002, OR 4.00, 95% CI 1.95-8.20). Multivariable analysis identified only two significant risk factors: Pre-operative pre-albumin (p=0.02, OR 0.76, 95% CI 0.60-0.96), and obesity measured by body mass index (BMI; p=0.001, OR 4.71, 95% CI 2.20-10.10). CONCLUSION: Obesity and nutritional status correlated with post-operative abdominal surgical site infection. The method of surveillance and length of follow-up impact the rate reported.

Colorectal carcinomas from Middle East. Molecular and tissue microarray analysis of genomic instability pathways.

OBJECTIVE: To evaluate the overall incidence of microsatellite instability (MSI), hereditary non polyposis colorectal cancer, and tumor supressor gene (TP53) mutations in Saudi colorectal carcinomas. METHODS: We studied the MSI pathway in Saudi colorectal cancers (CRC) from 179 unselected patients using 2 methods: MSI by polymerase chain reaction, and immunohistochemistry detection of mutL homologs 1 and mutS homologs 2 proteins. The TP53 mutations were studied by sequencing exons 5, 6, 7, and 8. RESULTS: Of the 150 colorectal carcinomas analyzed for MSI, 16% of the tumors showed high level instability (MSI-H), 19.3% had low-level instability (MSI-L) and the remaining 64% tumors were stable. Survival of the MSI-H group was better as compared to the MSI-L or microsatellite stable group (p=0.0217). In the MSI-H group, 48% were familial MSI tumors, which could be attributable to the high incidence of consanguinity in the Saudi population. The TP53 mutations were found in 24% of the cases studied. CONCLUSION: A high proportion of familial MSI cases and a lower incidence of TP53 mutations are some of the hallmarks of the Saudi colorectal carcinomas, which need to be explored further.