Lymph node dissection in esophageal carcinoma: Minimally invasive esophagectomy vs open surgery

Table 1 Group of lymph nodes

Region	Group
Upper mediastinal region	Right para-recurrent laryngeal nerve (RLN)
	Left para-RLN
	Upper para-esophagus
Carinal and hilar region	Subcarinal
	Left and right para-bronchi
Middle-low para-esophageal region	Middle and low para-esophagus
	Supra-diaphragm
Intraperitoneal region	Para-cardia
	Lesser gastric curvature
	Para-celiac artery and left gastric artery

Table 2 Characteristics of the open surgery and minimally invasive esophagectomy groups

	Open surgery (n = 324)	MIE (n = 123)	P value
Age (yr)	60.3 ± 7.8	60.1 ± 6.3	0.7821
Gender			0.0552
Male	226	97
Female	98	26
ASA grade			0.8202
I	15	6
II	248	97
III	61	20
Height (cm)	170.2 ± 4.8	171.1 ± 4.9	0.5851
Weight (kg)	65.2 ± 9.8	66.8 ± 8.1	0.1521
Smoker			0.9122
Never	123	46
Current or former	201	77
pT stage
Tis	3	4	0.077
T1	20	36	< 0.001
T2	46	72	< 0.001
T3	225	11	< 0.001
T4	30	0	< 0.001
Resection rate			0.4792
R0	313	121
R1	6	2
R2	5	0
Inductive chemo/radio therapy	40%	14%	0.7882
pTis/T1/T2	0	0
pT3	15	6	0.9122
pT4	25	0	0.002
LNM rate
pTis	0	0/4
pT1	6 (30)	10/36, 27.8%	0.8602
pT2	20 (43.4)	29/72, 40.3%	0.7312
pT3	125 (55.6)	5/11, 45.5%	0.5112
pT4	22 (73.3)	0
Surgical approach			< 0.001
Macheen	225	123
Ivor-Lewis	99	0

¹The t test;

²Fisher's exact test. LNM rate = number of patients with positive lymph nodes/number of total patients. LNM: Lymph node metastatic; MIE: Minimally invasive esophagectomy; ASA: American Society of Anesthesiologists.

Table 3 Comparison of the number of lymph node dissections and the rate of positive lymph nodes according to pathological T stage n (%)

	Number of lymph node dissections		P value1	Rate of positive lymph nodes		P value2	χ2
	Open	MIE		Open	MIE
pTis	18.3 ± 1.5	19.8 ± 1.3	0.2150	0	0
pT1	19.3 ± 4.1	21.4 ± 3.8	0.0593	21 (5.0)	50 (5.8)	0.579	0.308
pT2	20.2 ± 3.2	22.1 ± 6.6	0.0715	98 (10.1)	190 (11.0)	0.494	0.468
pT3	20.3 ± 5.8	23.2 ± 4.1	0.1030	733 (16.3)	32 (11.4)	0.031	4.626
pT4	21.5 ± 3.6	0		130 (17.8)	0
Total	20.4 ± 3.8	21.1 ± 4.3	0.0944	982 (14.8)	272 (9.5)	< 0.001	49.222

¹The t test;

²The χ² test. The rate of positive lymph nodes (pN+) = number of metastatic lymph nodes/number of removed lymph nodes. MIE: Minimally invasive esophagectomy.

Table 4 Comparison of lymph node sampling rates according to pathological T stage (Including Tis, T1-T4)

		LNS rates		P value1	χ2
		Open (n = 324)	MIE (n = 123)
Upper mediastinum	R-RLN	262	100	0.916	0.011
	L-RLN	260	54	< 0.001	56.345
	Upper para-esophagus	272	102	0.794	0.068
Subcarinal and parabronchial	Subcarinal	307	112	0.150	2.074
	Left and right parabronchial	310	120	0.353	0.863
Mid and low para-esophagus and diaphragm	Mid and lower para-esophagus	299	110	0.334	0.933
	Diaphragm	128	46	0.683	0.167
Intraperitoneal	Para-cardial	310	116	0.541	0.374
	Lesser gastric curvature	275	105	0.897	0.017
	Left gastric artery	272	106	0.560	0.339

¹The χ² test. LNS rates = number of patients undergoing lymph node sampling/number of total patients. LNS: Lymph node sampling; RLN: Recurrent laryngeal nerve; MIE: Minimally invasive esophagectomy.

Table 5 Comparison of lymph node metastatic rates according to pathological T stage

		pTis, T1-4		P value	χ2	pTis, T1-2		P value	χ2
		Open (n = 324)	MIE (n = 123)			Open (n = 69)	MIE (n = 112)
Upper mediastinum	R-RLN	71	10	0.001	11.416	6	9	0.876	0.024
	L-RLN	30	4	0.032	4.578	7	4	0.0452
	Upper para-esophagus	40	2	0.001	12.034	1	2	0.9992
Subcarinal and parabronchial	Subcarinal	36	11	0.505	0.445	5	8	0.979	0.001
	Left and right parabronchial	30	11	0.918	0.011	5	9	0.847	0.037
Mid and low para-esophagus and diaphragm	Mid and lower para-esophagus	59	10	0.008	6.939	6	9	0.876	0.024
	Diaphragm	3	1	0.910	0.013	1	1	0.9991
Intraperitoneal	Para-cardial	42	13	0.426	0.634	8	12	0.854	0.034
	Lesser gastric curvature	15	0			3	0	0.0421
	Left gastric artery	51	13	0.163	1.944	8	13	0.998	0.001

¹The Fisher's exact test;

²The χ² test. LNM rate = number of patients with positive lymph nodes/number of total patients. LNM: Lymph node metastatic; RLN: Recurrent laryngeal nerve; MIE: Minimally invasive esophagectomy.