Conversions In Minimally Invasive Colorectal Resections. Risk Assessment And Analysis Of Perioperative Results

INTRODUCTION: Since the first announced laparoscopic colorectal resections in the 1990s, this approach has become widely accepted due to its advantages and better perioperative results with long-term ones being comparable to those of open surgery. Nowadays, the minimally invasive approach is accepted as a gold standard in many centers. Despite this, there are situations which require conversion to open surgery during surgery. Conversion is related to loss of the potential benefits of the minimally invasive approach and is accompanied by a higher risk of complications. According to some publications, the conversion risk is up to 30%. Factors related to higher conversion risk are disease, patient, level of competence of the surgeon, and others. The risk factors should be identified before the surgery. Comparison of the results from open surgery with those of conversions can give the answer whether it is appropriate to begin every elective colorectal resection as minimally invasive or conversion might have poorer results than the open approach. AIM: The aim of this article is to conduct a comparative analysis of the perioperative results in a group of 31 conversions during 183 minimally invasive colorectal resections to 102 open resections. We aim to define and create a model of conversion risk factors based on preoperative data. MATERIALS AND METHODS: Based on retrospective study of 285 patients with elective colorectal resections divided into 3 groups—102 patients with open approach, 152 minimally invasive, and 31 conversions, perioperative results were reviewed. All the methods for clinical assessment were applied. Statistical analysis was performed with IBM SPSS Statistics 25.0; MedCalc Version 19.6.3, Excel Office 2021. The sensitivity and specificity of contrast-enhanced CT were used for preoperative assessment of stage T4 colorectal cancer. RESULTS: The conversion level in the group of minimally invasive resections was 16.93%. Perioperative mortality rate in converted patients was 0% compared to 1.96% in the open surgery group and 1.31% in the minimally invasive one. A higher morbidity rate was registered in conversion group—34.4%. The compli-cations were more severe according to Clavien-Dindo scale. Conversions were related to a longer hospital stay—8.58 days, compared to open surgery—7.61 days; longer operative time, and higher blood loss. Despite this, the harvested lymph nodes were more—15.88 for converted patients, 13.34 for the minimal-ly invasive group, and 11.11 for the open surgery patients. Factors with higher conversion rate were identified: male gender, comorbidity ≥3, age ≥78, BMI ≥30 kg/m2, palpable formation, CT T4 for colon cancer, MRI T4 for rectum, personal experience of the surgeon <38 minimally invasive resections, previous open surgery. CONCLUSION: Cases of locally advanced colorectal cancer, obese patients, previous major open surgery, and surgeons without a completed learning curve are factors related to a higher risk of conversion. Converted patients had poor perioperative results than open surgery patients.