Surgical Margins during Hepatic Surgery for Colorectal Liver Metastases: Complete Resection not Millimeters Defines Outcome

Excerpt

Several recent studies have indicated that a margin less than 1 cm is not a contraindication to resection of colorectal liver metastases (CLM).1‐3 In the one study2 that appropriately excluded from analyses those patients with positive margins, only number of metastases and extrahepatic disease - not margin width less than 1 cm - predicted outcome. In our own series of 557 patients undergoing resection of CLM, patients with a less-than-5-mm negative margin who underwent resection infrequently experienced recurrence locally (5%). Of note, the incidence of local recurrence was similarly uncommon (11%) in patients resected who had positive margins. Important, however, was the finding that only 17% of patients with a positive margin were alive after 5 years.1 In contrast, those patients with a negative margin had a 5-year survival of 64%, regardless of the width of the surgical margin. In multivariate analysis, tumor number greater than 3 and tumor size equal to or more than 5 cm, but not positive margins, were the main predictors of adverse outcome. In aggregate, these data strongly suggest that aggressive biological factors, and not necessarily margin status itself, dictate outcome following hepatic resection of CLMs. While adequate surgical margins are clearly important, the actual width may not be as critical in resecting CLMs because these lesions are histopathologically well circumscribed,4 only 16% have satellitosis,5 Glisson sheath extension is uncommon (14.5%) and limited (5 mm or less),6 and micrometastases are rare (2%).6 As such, the currently available data support the concept of limited complete resection utilizing a planned approach that encompasses all tumor-bearing liver parenchyma. …