Oliguric acute kidney injury after microwave ablation of large liver tumors: incidence and preventive measures

Figures & data

Table 1. Baseline characteristics of patients.

Features	No. of cases
Gender (Male/Female)	328 (74.4%)/113 (25.6%)
Age (≤60/>60)	256 (58.0%)/185 (42.0%)
Tumor no. (Solitary/Multiple)	221 (50.1%)/220 (49.9%)
Pathological types (Primary/metastasis/Benign)	261 (59.2%)/148 (33.6%)/32 (7.3%)
Tumor size (5–7 cm/7–10 cm)	347 (78.7%)/94 (21.3%)
Child-Pugh class (A/B)	416 (94.3%)/25 (5.7%)
AFP^a (≤20/>20)	261 (59.2%)/165 (37.4%)
CEA^a (≤5/>5)	286 (64.9%)/139 (31.5%)
CA199^a (≤28/>28)	236 (53.5%)/189 (42.9%)

^a For some reason, there were 15, 16 and 16 cases of missing data for tumor markers Alpha-fetoprotein (AFP), carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9), respectively.

Figure 1. The impact of risk factors among patients without AKI, with nonoliguric and oliguric AKI. (*p value was calculated using the Chi-square test for categorical variables and the independent t-test for continuous variables.) A. The impact of preventive measure; B. The impact of the number of electrodes; C. The impact of red blood cell (RBC) level; D. The impact of hemoglobin (HGB) level; E. The impact of albumin (Alb) level.

Table 2. The incidence and risk factors of AKI.

Factors	The type of AKI
	Normal	Nonoliguric	Oliguric	p*
Basic information
Gender				.436
Male	250 (76.2%)	68 (20.7%)	10 (3.0%)
Female	87 (77.0%)	25 (22.1%)	1 (0.9%)
Age				.740
≤60	198 (77.3%)	51 (19.9%)	7 (2.7%)
>60	139 (75.1%)	42 (22.7%)	4 (2.2%)
Tumor no.				.492
Solitary	171 (77.4%)	43 (19.5%)	7 (3.2%)
Multiple	166 (75.5%)	50 (22.7%)	4 (1.8%)
Pathological types				.500
Primary	199 (76.2%)	55 (21.1%)	7 (2.7%)
Metastasis	110 (74.3%)	35 (23.6%)	3 (2.0%)
Benign	28 (87.5%)	3 (9.4%)	1 (3.1%)
Tumor size				.138
5–7 cm	261 (75.2%)	79 (22.8%)	7 (2.0%)
7–10 cm	76 (80.9%)	14 (14.9%)	4 (4.3%)
Child-Pugh class
A	317 (76.2%)	88 (21.2%)	11 (2.6%)	.698
B	20 (80.0%)	5 (20.0%)	0 (0%)
Preventive measure				.043
B	112 (76.2%)	35 (23.8%)	0 (0%)
A	225 (76.5%)	58 (19.7%)	11 (3.7%)
Operation type				.227
Percutem	311 (77.2%)	82 (20.3%)	10 (2.5%)
Peritoneoscope	21 (70.0%)	9 (30.0%)	0 (0%)
Laparotomy	5 (62.5%)	2 (25.0%)	1 (12.5%)
Electrodes no.				<.001
Single	283 (80.2%)	61 (17.3%)	9 (2.5%)
Double	54 (61.4%)	32 (36.4%)	2 (2.3%)
Tumor markers
AFP				.055
≤20	195 (74.7%)	59 (22.6%)	7 (2.7%)
20–400	59 (90.8%)	6 (9.2%)	0 (0%)
>400	72 (72.0%)	25 (25.0%)	3 (3.0%)
CEA				.431
≤5	224 (78.3%)	56 (19.6%)	6 (2.1%)
>5	101 (72.7%)	34 (24.5%)	4 (2.9%)
CA199				.520
≤28	184 (78.0%)	48 (20.3%)	4 (1.7%)
>28	141 (74.6%)	42 (22.2%)	6 (3.2%)
Biochemical parameters before treatment^a
RBC (×10^13/L)	4.22 ± 0.58	4.17 ± 0.59	4.82 ± 0.52	.002
WBC (×10^9/L)	5.70 ± 2.17	5.86 ± 3.28	6.34 ± 2.47	.608
HGB (g/L)	128.36 ± 18.29	129.26 ± 16.81	147.09 ± 13.88	.003
PLT (×10^9/L)	160.91 ± 79.13	161.64 ± 79.19	197.73 ± 78.92	.316
Alb (g/L)	40.21 ± 5.43	40.68 ± 5.94	44.78 ± 3.33	.023
ALT (IU/L)	40.36 ± 67.17	30.88 ± 28.85	31.36 ± 12.29	.380
AST (U/L)	48.62 ± 106.07	39.86 ± 32.11	33.82 ± 18.67	.660
TB (µmol/L)	16.74 ± 12.44	15.55 ± 10.28	11.65 ± 4.22	.289
IBIL (µmol/L)	10.24 ± 8.47	9.54 ± 5.79	7.53 ± 2.85	.427
SCr (µmol/L)	62.97 ± 16.57	60.91 ± 17.03	64.69 ± 10.42	.518
BUN (mmol/L)	4.52 ± 4.01	4.98 ± 1.67		.429

* p value was calculated using the Chi-square test for categorical variables and an ANOVA test for continuous variables.

^a The continuous variable is represented by mean ± SD.

The details of biochemical parameters are as follows: RBC: red blood cells; WBC: white blood cells; HGB: hemoglobin; PLT: platelet count; Alb: albumin; ALT: alanine aminotransferase; AST: aspartate aminotransferase; TB: total bilirubin; IBIL: indirect bilirubin; SCr: serum creatinine; BUN: blood urea nitrogen.

Bold values means P values < = .05.

Table 3. The distribution of biochemical parameters after treatment, and their effects on the incidence of AKI.

Factor	After treatment (First Day) (Mean ± SD)
	Normal	Nonoliguric	Oliguric	p*
RBC (×10^13/L)	4.10 ± 0.62	4.08 ± 0.63	4.37 ± 0.54	.325
WBC (×10^9/L)	10.84 ± 4.44	13.74 ± 5.18	14.70 ± 4.52	<.001
HGB (g/L)	124.48 ± 18.91	126.34 ± 18.42	134.50 ± 15.18	.194
PLT (×10^9/L)	136.29 ± 65.63	126.59 ± 61.31	139.50 ± 59.70	.427
Alb (g/L)	36.49 ± 4.90	36.95 ± 5.40	35.94 ± 1.75	.666
ALT (IU/L)	322.90 ± 283.88	532.43 ± 561.22	725.55 ± 560.67	<.001
AST (U/L)	609.64 ± 794.91	962.73 ± 855.98	948.82 ± 764.21	.001
TB (µmol/L)	34.48 ± 25.55	44.58 ± 42.60	31.45 ± 13.27	.014
IBIL (µmol/L)	22.21 ± 15.95	25.82 ± 17.91	19.48 ± 7.54	.166
SCr (µmol/L)	64.57 ± 19.08	117.94 ± 46.23	184.48 ± 69.28	<.001
BUN (mmol/L)	6.22 ± 1.78	9.24 ± 2.94	14.15 ± 6.86	<.001

* p value was calculated using the ANOVA analysis.

The details of biochemical parameters are as follow: RBC: red blood cells; WBC: white blood cells; HGB: hemoglobin; PLT: platelet count; Alb: albumin; ALT: alanine aminotransferase; AST: aspartate aminotransferase; TB: total bilirubin; IBIL: indirect bilirubin; SCr: serum creatinine; BUN: blood urea nitrogen.

Bold values means P values < = .05.

Figure 2. The comparison of the values of RBC, HGB and WBC before and after treatment (*p value was calculated using the independent t-test. The value marked in the picture represents the change in levels before and after the treatment. A. The value of red blood cells (RBC); B. The value of hemoglobin (HGB); C. The value of white blood cells (WBC).

Figure 3. The comparison of Na⁺, K⁺ and Cl⁻ in patients with different AKI type. (*p value was calculated using the independent t-test.) A. The value of Na⁺; B. The value of K⁺; C. The value of Cl⁻.

Table 4. Information on the duration of postoperative hospital stay.

	Postoperative hospital stay (days, mean ± SD)	p*
AKI type
None	4.72 ± 4.46	Nonoliguric vs. None, .260
Nonoliguric		Oliguric vs. None, <.001
Oliguric	15.00 ± 5.57	Nonoliguric vs. Oliguric, <.001
Preventive measure^a (Total patients)		.023
B	4.40 ± 3.48
A	5.45 ± 4.99
Preventive measure (Patients with AKI)		<.001
B	3.97 ± 1.29
A	7.51 ± 5.34

* p value was calculated using the independent t-test.

^aPreventive measures: A, Preventive measures were carried out at 1–1.5 h after anesthesia recovery from ablation. B, Preventive measures were done during ablation (when half of the tumor was ablated).

Bold values means P values < = .05.

Table 5. The comparison of biochemical parameters in AKI patients treated with and without preventive measures.

Factors	Before treatment (Mean ± SD)			After treatment (Mean ± SD) (First day)				After treatment (Mean ± SD) (Maximum creatinine)
	Preventive measure B	Preventive measure A	p*	Preventive measure B	Preventive measure A		p*	Preventive measure B	Preventive measure A	p*
Cellular analysis
RBC (×10^9/L)	4.09 ± 0.54	4.32 ± 0.64	.073	4.15 ± 0.58	4.09 ± 0.65		.626	4.14 ± 0.59	3.85 ± 0.65	.030
WBC (×10^9/L)	5.82 ± 2.10	5.96 ± 3.63	.839	13.44 ± 5.36	14.03 ± 5.00		.578	13.06 ± 5.15	13.30 ± 5.12	.824
HGB (g/L)	125.32 ± 18.24	131.17 ± 13.16	.066	127.11 ± 18.67	127.14 ± 18.13		.993	126.74 ± 18.87	120.33 ± 18.83	.104
PLT (×10^9/L)	177.62 ± 85.27	159.52 ± 76.53	.280	141.40 ± 62.33	120.87 ± 59.54		.106	137.86 ± 59.96	117.46 ± 59.58	.103
Liver function
Alb (g/L)	40.69 ± 5.25	41.33 ± 6.15	.597	36.87 ± 5.10	36.84 ± 5.19		.979	36.87 ± 4.98	36.40 ± 6.30	.701
ALT (IU/L)	28.88 ± 31.37	31.97 ± 25.55	.591	426.18 ± 284.74	617.11 ± 651.74		.102	424.78 ± 285.69	485.83 ± 478.66	.490
AST (U/L)	34.03 ± 18.79	41.86 ± 35.41	.225	795.71 ± 509.16	1045.23 ± 962.46		.155	787.49 ± 515.41	649.51 ± 642.02	.273
TB (µmol/L)	14.05 ± 8.11	15.69 ± 10.68	.426	33.25 ± 24.08	48.47 ± 46.52		.073	33.05 ± 24.12	42.56 ± 49.24	.284
IBIL (µmol/L)	8.52 ± 5.04	9.75 ± 5.82	.293	18.80 ± 10.27	28.89 ± 19.34		.007	18.64 ± 10.35	22.92 ± 18.37	.223
Renal function
SCr (µmol/L)	60.06 ± 21.59	61.94 ± 13.27	.585	96.92 ± 26.97	139.21 ± 57.12	<.001		96.63 ± 27.70	301.07 ± 377.61	.002
BUN (mmol/L)	5.14 ± 1.38	4.59 ± 2.15	.269	8.35 ± 2.58	10.21 ± 3.48	.019		8.39 ± 2.65	17.79 ± 10.89	<.001

* p value was calculated using the independent t-test.

The details of biochemical parameters are as follows: RBC: red blood cells; WBC: white blood cells; HGB: hemoglobin; PLT: platelet count; Alb: albumin; ALT: alanine aminotransferase; AST: aspartate aminotransferase; TB: total bilirubin; IBIL: indirect bilirubin; SCr: serum creatinine; BUN: blood urea nitrogen.

Bold values means P values < = .05.