Conversion risk factors in laparoscopic colorectal surgery

This study is aimed at identifying important risk factors associated with conversion of laparoscopic colorectal surgery. Laparoscopic surgery is usually associated with less operative trauma, more favourable post-operative course and lower morbidity than open surgery. However, conversion is connected with some risks according to some authors.

To identify the risk factors associated with conversion and to create a model to predict possible conversion for a patient before surgery.

The source data file contained information about 649 patients who underwent laparoscopic colorectal surgery between 2001 and 2009 at the University Hospital Ostrava, Czech Republic. Conversion to open surgery was necessary in 54 cases. The variables gender, body mass index (BMI), American Society of Anesthesiologists (ASA) classification, stage of disease, number of previous operations and operation severity were included in the analysis as the potential risk factors of conversion. Discriminant analysis was used for the data evaluation; statistical software SPSS 17 and NCSS 2004 were used for the calculations.

The created model had only low discriminating ability. The variable ASA classification was identified as the most important risk factor of conversion, followed by the variables operation severity, gender and BMI.

Discriminant analysis did not find the chosen input variables satisfactory enough to make a reasonable model for the prediction of conversion. The expected fact was confirmed that large bowel surgery and greater BMI mean greater risk of conversion, whereas there is no reason to refuse laparoscopy for a patient with higher ASA classification.