Lymphadenectomy Around Inferior Mesenteric Artery in Low-Tie vs High-Tie Laparoscopic Anterior Resection: Short- and Long-Term Outcome of a Cohort of 614 Rectal Cancers

Figures & data

Figure 1 (A) High-tie, the IMA is ligated at its origin within 1 cm from the aorta, with dissection of the apical lymph nodes (LN); (B) Low-tie, the IMA and the proximal left colic artery (LCA) are skeletonized, LCA is preserved, the superior rectal artery (SRA) is ligated, LN dissection medially along the IMA root, including the abdominal aortic (AA) plane.

Figure 2 (A) Tension-free anastomosis after low-tie of IMA and preservation of LCA; (B) Completion of laparoscopic surgery for rectal cancer and skin closure of ports; (C-D) Retrieved specimen after low-tie and total mesorectal excision (TME) for rectal cancer.

Table 1 Clinicodemographic Profile of Patients with Low-Tie vs High-Tie of the Inferior Mesenteric Artery in Laparoscopic Anterior Resection of Rectal Cancer, N=614

Clinical Profile	LT^a 236 (38.44%)	HT^b 378 (61.56%)	p-value
Age (years)	62.05 ± 0.68	63.25 ± 0.58	0.189
BMI	22.12 ± 0.18	22.34 ± 0.15	0.372
Gender
Male	140 (59.32)	220 (58.20)	0.784
Female	96 (40.68)	158 (41.80)
Diabetes and/or hypertension
Yes	45 (19.07)	48 (12.69)	0.032
No	191 (80.93)	330 (87.31)
Neoadjuvant
Yes	34 (14,41)	43 (11.38)	0.270
No	202 (85.59)	335 (88.62)
ASA grade
1	126 (53.40)	189 (50.00)	0.547
2	58 (24.58)	108 (28.57)
3	52 (22.02)	81 (21.43)
Tumor size (cm)
≤ 5	152 (64.41)	223 (58.99)	0.181
> 5	84 (35.59)	155 (41.01)
CEA level (ng/mL)
≤ 5	127 (53.81)	203 (53.70)	0.979
> 5	109 (46.19)	175 (46.30)
Tumor location
Upper rectum^c	142 (60.17)	234 (67.24)	0.080
Lower rectum^c	94 (39.83)	144 (32.76)

Notes: ^aLT- low-tie with ligation of inferior mesenteric artery (IMA) distal to the branching of the left colic artery (LCA) with en-bloc lymph node dissection around IMA and preservation of LCA, ^bHT- high-tie with ligation of IMA at its root proximal to the branching of LCA; ^cTumor in upper rectum – above the peritoneal reflection and lower rectum below the peritoneal reflection.

Abbreviations: ASA, American Society of Anesthesiologist; CEA, carcinoembryonic antigen.

Table 2 Operative Findings of Rectal Cancer Patients with LT vs HT in Laparoscopic Anterior Resection of Rectal Cancer, N=614

Clinicopathological Feature	LT 236 (38.44%)	HT 378 (61.56%)	p-value
Duration of surgery (min)	146.0 ± 2.46	138.6 ± 2.01	0.021
Time for IMA tie	41.46 ± 0.66	32.69 ± 0.59	0.000
Time for TME	74.79 ± 2.13	73.46 ± 2.14	0.675
Blood loss (mL)	125.1 ± 5.74	113.6 ± 4.03	0.092
Blood transfusion (n)	9 (3.81)	11 (2.91)
Anastomosis from anal verge (cm)	4.02 ± 0.15	3.93 ± 0.15	0.693
No. of lymph nodes harvested
Total	17.23 ± 0.30	17.51 ± 0.22	0.452
Lymph nodes around IMA	3.15± 0.06	3.23 ± 0.05	0.338
Intermediate lymph nodes	3.88 ± 0.09	3.72 ± 0.06	0.116
Perirectal lymph nodes	10.20 ± 0.30	10.56 ± 0.22	0.331
Lymph node involvement
Lymph nodes around IMA	13 (5.5)	17 (4.49)
Intermediate lymph nodes	21 (8.89)	37 (9.78)
Perirectal lymph nodes	87 (36.86)	134 (35.45)
Pathological proximal margin (cm)	13.90 ± 0.09	14.04 ± 0.08	0.249
Pathological distal margin (cm)	2.87 ± 0.08	2.79 ± 0.06	0.444

Table 3 Risk Factors for Anastomotic Leakage in Patients with LT vs HT in Laparoscopic Anterior Resection for Rectal Cancer, N=614

Clinicopathological Feature	LT N (%)	HT N (%)	p value
Age ≥ 65 years	105	194
AL	13 (12.38)	37 (19.02)	0.148
No-AL	92 (87.62)	157 (80.98)
Male	140	220
AL	15 (10.71)	21 (12.27)	0.653
No-AL	125 (89.29)	199 (87.73)
Diabetes and/or hypertension	45	48
AL	5 (11.11)	11 (22.91)	0.132
No-AL	40 (88.89)	37 (77.09)
Neoadjuvant treatment	34	43
AL	5 (14.71)	10 (23.26)	0.347
No-AL	29 (85.29)	33 (76.74)
Tumor location in lower rectum	94	144
AL	10 (10.64)	30 (20.83)	0.040
No-AL	84 (89.36)	114 (79.17)

Table 4 Hazard Ratio in for Anastomotic Leakage in Patients with LT vs HT in Laparoscopic Anterior Resection for Rectal Cancer, N=614

Clinical Parameter	Univariate Analysis			Multivariate Analysis
	HR	95% CI	p	HR	95% CI	p
IMA ligation (high-tie vs low-tie)	1.62	1.56–1.65	0.047	1.71	0.99–2.94	0.051
Age (≥65 vs <65 years)	1.49	1.45–1.53	0.001	2.15	1.29–3.58	0.003
Gender (male vs female)	1.59	1.55–1.63	0.031	1.55	0.95–2.55	0.078
Tumor Size (>5 cm vs ≤5 cm)	1.30	1.27–1.34	0.421	-	-	-
Diabetes and/or hypertension (Yes vs No)	1.15	1.12–1.18	0.868	-	-	-
Tumor location (low vs high)	1.39	1.35–1.43	0.011	1.66	0.98–2.82	0.058
Neoadjuvant treatment (Yes vs No)	1.13	1.10–1.15	0.043	1.54	0.77–3.06	0.216

Abbreviations: HR, hazard ratio; CI, confidence interval; p, p value.

Table 5 Long-Term Results of Overall Survival (OS) and Disease-Free Survival (DFS) in Patients with LT vs HT Anterior Resection of Rectal Cancer, N=614

Long-Term Outcome	LT %	HT %	p-value
3-year OS rate (%)
All patients (n=614)	81.78	83.33	0.658
With LN metastasis around IMA	69.23	76.47	0.726
Without LN metastasis around IMA	84.30	86.15	0.543
3-year DFS rate (%)
All patients (n=614)	78.38	83.33	0.143
With LN metastasis around IMA	61.53	64.71	0.951
Without LN metastasis around IMA	79.37	84.21	0.148
5-year OS rate (%)
All patients (n=532)	59.51	61.46	0.671
With LN metastasis around IMA	53.85	53.33	0.924
Without LN metastasis around IMA	59.90	61.86	0.667
5-year DFS rate (%)
All patients (n=532)	52.20	53.52	0.690
With LN metastasis around IMA	38.46	40.00	0.968
Without LN metastasis around IMA	53.13	54.17	0.723

Figure 3 Long-term outcomes in the low-tie groups and high-tie groups. (A) 3-years OS with all patients, LN metastasis around IMA patients, and without LN metastasis around IMA patients; (B) 3-years DFS with all patients, LN metastasis around IMA patients, and without LN metastasis around IMA patients; (C) 5-years OS with all patients, LN metastasis around IMA patients, and without LN metastasis around IMA patients; (D) 5-years DFS with all patients, LN metastasis around IMA patients, and without LN metastasis around IMA patients.