ALPPS for Synchronous CRLM - Liver first vs. Standard Approach

Hypothesis: ALPPS combined with simultaneous colorectal primary tumour resection is a safe approach for synchronous colorectal metastases. Study design: A retrospective analysis of all patients registered in the ALPPS registry for colorectal liver metastases. Study questions: With respect to patient outcomes including complete resection with R0 margins, in-hospital mortality, 90 day mortality, length of hospital stay, postoperative liver failure, postoperative bile leak, comprehensive complication index, failure to reach the second operation, and progression of primary or metastatic tumours, how do the following three approaches to combining ALPPS with primary tumour resection compare with one another? 1. The “classical approach” consisting of two separate operations (primary tumour resection first, followed by liver resection second)? 2. The “reverse approach” consisting of two separate operations (liver resection first for metastatic tumours, followed by primary tumour resection second)? 3. The combined approach involving simultaneous colorectal liver metastasis resection as well as primary tumour resection. Possible confounders/co-variables to be included 1. Age. 2. Sex. 3. Location of primary tumour. 4. Size of primary tumour. 5. Primary tumour lymph nodes. 6. Type of colorectal surgery performed. 7. Number of liver metastases. 8. Location and size of metastases. 9. Specific type of ALPPS (number of segments in FLR, what side). 10. Patient medical history and comorbidities. 11. Neoadjuvant/adjuvant therapy. 12. Preoperative CEA level. 13. Hepatic macrosteatosis.