An Analysis of Free-hand Targeting in Laparoscopic Liver Microwave Ablation

Recently, new technologies have been developed for antenna placement in laparoscopic liver tumor ablation (LLTA). At this point, it is important to analyze the efficacy of free-hand targeting to identify deficiencies and opportunities for improvement.

This was an institutional review board-approved retrospective study. Video recordings of 30 consecutive patients with 77 lesions who underwent LLTA were reviewed. Tumor-specific anatomic and targeting-related parameters were analyzed using χ2, t test, and regression analyses.

Neuroendocrine metastasis was the dominant tumor type, with median tumor size 1.4 cm (range, 0.5 to 5.2). In total, 41 (53%) tumors were superficial and 36 (47%) deep. In 68 lesions (88%), an optimal targeting was achieved with first attempt, without a need for repositioning; whereas 9 lesions (12%) required repositioning of antenna. For 37% (15/41) of superficial and 56% (20/36) of deep lesions, a straight avascular needle trajectory was not present, requiring steering of the antenna around vascular and biliary structures. All procedures were completed laparoscopically without bleeding or biliary complications. Local treatment recurrence rate in follow-up was 10% (n=8).

This study shows that in experienced hands, LLTA through free-hand technique is safe and efficacious, providing an accurate targeting with the first pass in 90% of tumors. Although newer technology is being developed to guide less-experienced surgeons in needle targeting, it should be kept in mind that a straight trajectory is not available for 1/3 of superficial and half of deep lesions. Hence, ablation surgeons need to develop free-hand skills to avoid possible hemorrhagic and biliary complications in LLTA.