Efficacy and safety of artificial ascites in assisting percutaneous microwave ablation of hepatic tumours adjacent to the gastrointestinal tract

Figures & data

Table I. Clinical features of patients and tumours.

Variable	Datum
Patient analysis (n = 36)
Gender (male/female)	27/9
Age (in years) mean ± SD (range)	59.2 ± 11.2 (40.7–83.0)
Patients with HCC	25
Seropositive for HBV/HCV/both	21/3/1
Child-Pugh classification (A/B)	22/3
Patients with metastatic liver cancer	11
Primary site
Colorectal cancer	4
Gastric cancer	2
Esophageal cancer	1
Pancreatic cancer	1
Gallbladder cancer	1
Ovarian cancer	1
Lung cancer	1
Previous history
Laparotomy	13
TACE	10
Tumour analysis (n = 36)
Tumour size (in cm) mean ± SD (range)	2.8 ± 1.0 (1.1–5.0)
Location
Segment II–III	16
Segment IV	3
Segment V–VI	17
Adjacent to gastrointestinal tract
Stomach	17
Small or large intestine	19

HBV, hepatitis B virus; HCC, hepatocellular carcinoma; HCV, hepatitis C virus; SD, standard deviation; TACE, transcatheter hepatic arterial chemoembolisation.

Figure 1. Artificial ascites technique in assisting MW ablation of hepatic tumours adjacent to the gastrointestinal tract. (A) A 16-gauge IV catheter (arrowheads) is inserted into the space between the surface of the liver and the gastrointestinal tract along the edge of the liver under ultrasound guidance. (B) The outer catheter (arrowheads) is advanced further to close to the index tumour whenever possible; then the inner stylet (arrow) is removed. (C) CEUS is helpful to best display the position of catheter (arrow). (D) Artificial ascites (*) successfully separates the gastrointestinal tract (☆) from the ablated area (arrow). The drip infusion is continued via the catheter (arrowhead) during the MW ablation procedure.

Figure 2. A 73-year-old man with a 2.7-cm HCC in the right lobe of the liver. (A) Ultrasound shows that artificial ascites (*) successfully separates the intestine (☆) from the index tumour (arrow) located at the edge of hepatic segment V. Note the IV catheter (arrowheads). (B) A thermocouple (arrowheads) is placed into artificial ascites (*) between the index tumour (arrow) and the intestine (☆) under ultrasound guidance. (C) Coronal contrast-enhanced MRI before MW ablation shows a tumour (arrow) located at the edge of segment V close to the intestine. (D) Coronal contrast-enhanced MRI 1 month after MW ablation shows the ablation zone (arrow).

Table II. Relationship between separability and history of laparotomy or TACE.

	Separability
History of laparotomy or TACE	Yes	No	Total
Yes	21	2	23
No	11	2	13
Total	32	4	36

p = 0.609 (Fisher’s exact test). TACE, transcatheter hepatic arterial chemoembolisation.

Figure 3. A 42-year-old woman with metastatic liver cancer in the left lobe of the liver. (A) Ultrasound shows a 1.7-cm hypoechoic nodule (arrow) located at the edge of hepatic segment III adjacent to the stomach (arrowheads). (B) After the induction of artificial ascites (*), the stomach (☆) is successfully separated from the ablated area (arrow). (C) Transverse contrast-enhanced MRI before MW ablation shows a tumour (arrow) with ring enhancement located at the edge of segment III adjacent to the stomach. (D) Transverse contrast-enhanced MRI 1 month after MW ablation shows that the tumour is completely ablated (arrow).

Table III. Characteristics of cases with local tumour progression.

Patient	Diagnosis	Size (cm)	Segment	Adjacent organ	Time (s)	Artificial ascites (mL)	Treatment
1	HCC	2.0	IV	Stomach	210	500	MWA
2	Metastasis	2.5	V	Intestine	420	620	Radiotherapy
3	HCC	3.0	V	Intestine	330	700	MWA
4	Metastasis	3.8	III	Stomach	480	620	MWA
5	HCC	2.7	V	Intestine	540	800	MWA

HCC, hepatocellular carcinoma; MWA, microwave ablation.