Use of a saline-coupled bipolar sealer open liver resection for hepatic malignancy: Medical resource use and costs

Table 1 Definition of deviation mix for deviation-based cost modeling

Deviation	LOS	Complication group1
On course	≤ 50th percentile	No complication
Minor deviation	> 50th percentile	No complication
	≤ 50th	Minor complication, no moderate or major
Moderate deviation	> 50th percentile	Minor complication, no moderate or major
	Any LOS	Moderate no major
Major deviation	Any LOS	Major

¹Minor complication: Transfusion, urinary tract infection, hemorrhage/hematoma, wound disruption, or transfusion complications; Moderate complication: Deep vein thrombosis, pulmonary embolism, pneumonia, infection, or bile leak; Major Complication: Acute respiratory failure, acute kidney injury, or acute liver failure. LOS: Length of stay.

Table 2 Patient demographics n (%)

	Unmatched		P value	Matched		P value
	SCBS	No SCBS		SCBS	No SCBS
n	152	2993		144	720
Age, mean (SD)	62 (12.5)	61.58 (12.1)	0.683	61.49 (12.5)	62.14 (12.1)	0.568
Age group1						0.960
18 to 44	10 (6.6)	262 (8.8)	0.868	10 (6.9)	49 (6.8)
45 to 54	29 (19.1)	536 (17.9)		28 (19.4)	143 (19.9)
55 to 64	44 (28.9)	914 (30.5)		44 (30.6)	198 (27.5)
65 to 74	46 (30.3)	862 (28.8)		41 (28.5)	220 (30.6)
75 plus	23 (15.1)	419 (14.0)		21 (14.6)	110 (15.3)
Race			0.148			0.692
Black	18 (11.8)	368 (12.3)		18 (12.5)	87 (12.1)
Caucasian	83 (54.6)	1788 (59.7)		76 (52.8)	407 (56.5)
Hispanic	0 (0)	41 (1.4)		0 (0)	0 (0)
Other	51 (33.6)	796 (26.6)		50 (34.7)	226 (31.4)
Region			< 0.001			0.892
Midwest	31 (20.4)	304 (10.2)		26 (18.1)	112 (15.6)
Northeast	52 (34.2)	959 (32.0)		49 (34.0)	260 (36.1)
South	41 (27.0)	1321 (44.1)		41 (28.5)	206 (28.6)
West	28 (18.4)	409 (13.7)		28 (19.4)	142 (19.7)
Sex
Female	71 (46.7)	1315 (43.9)	0.556	67 (46.5)	308 (42.8)	0.461
Payor			0.577			0.903
Commercial	49 (32.2)	1166 (39.0)		49 (34.0)	234 (32.5)
Medicare	21 (13.8)	362 (12.1)		21 (14.6)	111 (15.4)
Medicaid	73 (48.0)	1302 (43.5)		65 (45.1)	341 (47.4)
Other	9 (5.9)	163 (5.5)		9 (6.3)	34 (4.7)

¹Excluding primary malignancy, metastatic solid tumor, mild liver disease, moderate or severe liver disease. P values were calculated with the χ² test (or Fisher’s Exact where cell frequencies < 10), t-test (or Wilcoxon Mann-Whitney test for skewed distributions). SCBS: Saline-coupled bipolar sealer.

Table 3 Clinical characteristics n (%)

	Unmatched		P value	Matched		P value
	SCBS	No SCBS		SCBS	No SCBS
n	152	2993		144	720
Procedure Type
Partial hepatectomy	99 (65.1)	2061 (68.9)	0.308	98 (68.1)	478 (66.4)	0.772
Lobectomy	53 (34.9)	964 (32.2)	0.552	46 (31.9)	251 (34.9)	0.564
Indicating diagnosis
Primary hepatobiliary malignancy	63 (41.5)	850 (28.4)	0.001	56 (38.9)	300 (41.7)	0.599
Metastatic liver neoplasm	89 (58.6)	2143 (71.6)	0.001	88 (61.1)	420 (58.3)	0.599
Comorbid liver diagnoses
Alcoholic cirrhosis	1 (0.66)	33 (1.1)	0.908	1 (0.69)	4 (0.56)	1.000
Non-alcoholic cirrhosis	23 (15.1)	287 (9.6)	0.036	20 (13.9)	100 (13.9)	1.000
Hepatitis A	0 (0)	6 (0.2)	1.000	0 (0)	0 (0)	N/A
Hepatitis B	18 (11.8)	193 (6.4)	0.015	16 (11.1)	96 (13.3)	0.556
Hepatitis C	17 (11.2)	271 (9.1)	0.457	17 (11.8)	71 (9.9)	0.580
Charlson score group1			0.518			0.704
0	76 (50)	1637 (54.7)		74 (51.4)	370 (51.4)
1	45 (29.6)	816 (27.3)		43 (29.9)	196 (27.2)
≥ 2	31 (20.4)	540 (18.0)		27 (18.8)	154 (21.4)
Provider specialty
Surgical oncology	59 (38.8)	531 (17.7)	< 0.001	56 (38.9)	285 (39.6)	0.950
General surgery	79 (52.0)	1993 (66.6)	< 0.001	74 (51.4)	369 (51.3)	1.000
Other	14 (9.2)	469 (15.7)	0.041	14 (9.7)	66 (9.2)	0.958
Surgeon experience
≥ 1 liver procedure in prior year	125 (82.2)	1991 (66.6)	< 0.001	117 (81.3)	595 (82.6)	0.780

¹Excluding primary malignancy, metastatic solid tumor, mild liver disease, moderate or severe liver disease. P values were calculated with the χ² test (or Fisher’s Exact where cell frequencies < 10), t-test (or Wilcoxon Mann-Whitney test for skewed distributions). SCBS: Saline-coupled bipolar sealer.

Table 4 Length of stay, deviation mix and weighted average mean cost (propensity-matched cohorts)

Characteristic	SCBS	No SCBS	P value
Length of stay (LOS), d
mean (SD)	7.38 (5.18)	8.18 (7.27)	0.210
25th percentile	4	4
Median	6	6
75th percentile	8	8
Deviation mix, n (%)
On course	77 (53.5)	302 (41.9)	0.013
Minor deviation	30 (20.8)	187 (26.0)	0.208
Moderate deviation	28 (19.4)	150 (20.8)	0.821
Major deviation	9 (6.3)	81 (11.3)	0.074
mean (SD) total hospital cost
On course	18000 (5746)	16813 (6588)	0.029
Minor deviation	28379 (14863)	25452 (11186)	0.454
Moderate deviation	36558 (17777)	35261 (19390)	0.571
Major deviation	45717 (19045)	49082 (35303)	0.568
WAMC total hospitalization cost	$25503	$26530
WAMC difference	$1027

P values were calculated with the Wilcoxon Mann-Whitney test for LOS and total hospitalization cost; and the χ² test for hospital deviation mix classes. SCBS: Saline-coupled bipolar sealer; WAMC: Weighted average mean cost.

Table 5 Logistic regressions of predictors of topical hemostat use and transfusion

Parameter	Predictors of topical hemostat use			Predictors of transfusion
	Odds ratio	95%CI	P value	Odds ratio	95%CI	P value
Age group (vs 18 to 44)
75 plus	1.03	0.50-2.12	0.421	4.55	1.95-10.59	< 0.0001
Race (vs caucasian)
Black	1.21	0.75-1.97	0.275	1.97	1.21-3.19	0.017
United States geographic region (vs northeast)
South	3.67	2.38-5.65	0.0004	1.87	1.19-2.96	0.001
Partial hepatectomy (vs lobectomy)	1.25	0.91-1.73	0.175	1.62	1.16-2.27	0.005
Primary malignancy (vs metastatic)	0.80	0.53-1.20	0.281	1.54	1.00-2.38	0.050
Provider specialty (vs general surgery)
Surgical oncology	0.30	0.20-0.46	< 0.0001	0.65	0.42-1.01	0.005
Other specialty	0.68	0.40-1.16	0.402	1.48	0.85-2.57	0.023
Case cohort (vs matched controls)	2.56	1.70-3.86	< 0.0001	0.44	0.27-0.71	0.0008
Topical hemostat use	N/A	N/A	N/A	1.87	1.33-2.64	0.0004

Only covariates that were significant in at least on model (P < 0.05) are listed here. Full model covariates included: age group, sex, race, geographic region, resection type, malignancy type, diagnosis of non-alcoholic cirrhosis, hepatitis b, or hepatitis C, provider specialty, study cohort, and topical hemostat use.