Percutaneous microwave ablation for benign focal liver lesions: Initial clinical results

Abstract

Abstract. Benign focal liver lesions (BFLLs) have become a common disease diagnosed in the clinical setting following the advancement of imaging techniques. The aim of the present study was to evaluate the safety and clinical outcomes of percutaneous microwave (MW) ablation, guided by ultrasound (US), for the treatment of BFLLs. Between May 2005 and January 2011, 44 BFLLs (mean maximum diameter, 33.9±13.1 mm) in 37 patients (23 women and 14 men) were treated by US-guided percutaneous MW ablation with cooled-shaft antennae. The pathological diagnosis of a BFLL was confirmed in 91.9% (34/37) of patients using a US-guided core needle biopsy prior to ablation. The BFLLs in the other 3 cases were diagnosed by typical presentations on contrast-enhanced imaging, as the patients refused to undergo biopsies. Five inclusion criteria, including indeterminate diagnoses of nodules on contrast-enhanced imaging prior to pathological verification, were recommended. The median follow-up period was 27.0 months (range, 6-73 months). The mean MW ablation energy and time were 55.0±41.6 kJ (range, 13.5-207 kJ) and 1,039.9±706.2 sec (range, 270-3,450 sec) per lesion, respectively. In total, 40 nodules (90.9%) were completely ablated, and no evidence of recurrence was demonstrated on contrast-enhanced imaging follow-up. The other 4 nodules (9.1%) were partially ablated due to the proximity of adjacent vital organs. Minor complications without sequelae included local pain and transient hemoglobinuria and no major complications occurred in peri-ablation. Overall, US-guided percutaneous MW ablation is a safe, effective and minimally invasive therapy for BFLLs in selected patients who are non-surgical candidates.

Current concepts in ablative procedures for primary benign liver lesions: a step forward to minimize the invasiveness of treatment when deemed necessary

“…General contraindications were: severe blood coagulation dysfunction, active inflammatory or infectious process, acute or severe renal insufficiency, pulmonary or cardiac dysfunction [14]. If the lesion was uncertain for malignancy based on radiologic examination alone, surgery was considered the treatment of choice [10].…”

“…Wang and Cheng described the development of post-ablation systemic inflammatory response (SIR) in 50% and 75.7% of patients, respectively, within two days after intervention [14,19]. Wang and colleagues reported low fever, constipation, slight wound pain, stomach discomfort and other MWA minor postoperative reactions in 11 out of 12 treated patients [15].…”

“…A few studies [14,24,27] dealt with the percutaneous ablation of BLTs different from HHs and HCAs. These series were mostly heterogeneous in terms of tumor histology and treatment strategy.…”

“…MWA under US guidance was employed by Cheng el al. [14] to treat diverse BLT subtypes, including 5 FNHs, 6 inflammatory pseudotumors, 5 solitary necrotic nodules, 3 angiomyolipomas, and 1 epithelioid hemangioendothelioma. The patients selected to undergo ablation had an indeterminate diagnosis on the basis of imaging features, an enlarging benign nodule (greater than 1 cm within one year); were at risk of malignant evolution; had symptoms supposed to be associated with the BFL presence; or heavy psychological pressure for the detection of an hepatic neoplasm, despite a definite diagnosis of a benign condition.…”

“…There is insufficient evidence to support or refute ablation therapies for FNH, given that reassurance regarding the stable nature of the lesion and the lack of complications is given to patients and constitutes the only suggested management strategy in most cases [1,2]. Moreover, the correlation between the presence of FNH and symptoms is poor, and treatment is rarely indicated even in symptomatic subjects [2], limiting the choice to treat only for exceptional cases [14]. At present, there are no published randomized controlled trials comparing the outcomes of TAE or RFA with those of either surgery or conservative management.…”