Learning curve of laparoscopy-assisted distal gastrectomy with systemic lymphadenectomy for early gastric cancer

Table 1 Characteristics and pathologic results of patients

	Total	1–50 cases	51–90 cases	P
Total number of patients	90	50	40
Age (yr, mean±SD)	55.7±12.0	56.3±11.3	54.9±12.9	0.6907
Sex ratio (male:female)	50:40	26:24	24:16	0.5854
Body mass index (kg/m2, mean±SD)	22.8±2.7	23.1±2.5	22.5±2.9	0.1700
Comorbidity (%)	29 (32.2)	13 (26.0)	16 (40.0)	0.2359
Method of reconstruction				0.5343
B–I	67	39	28
B–II	23	11	12
T stage				0.1758
Tis	2	1	1
Tm	66	33	33
Tsm	22	16	6
N stage				0.8439
N0	87	49	38
N1	3	1	2
Extent of lymphadenectomy				0.4709
D1+α	11	8	3
D1+β	68	36	32
D2	11	6	5
Retrieved LN number (mean±SD)	27.0±9.7	25.4±10.0	28.9±8.9	0.1330
Resection margin (cm, mean±SD)
Proximal	4.2±2.6	3.8±2.4	4.7±2.7	0.1472
Distal	5.1±3.1	5.0±3.1	5.3±3.0	0.5752

LN, lymph node; D1+α: D1+no. 7 LN; D1+β: D1+no. 7, 8a, 9 LN; D2: D1+β+no. 11p, 12a, 14v LN.

Table 2 Overall postoperative outcomes

	Total	1–50 cases	51–90 cases	P
Operative time (min, mean±SD)	227.2±48.0	251.3±47.3	227.2±48.0	<0.0001
No. of transfused patients (%)	5 (5.6)	3 (6.0)	2 (5.0)	0.837
Time to first flatus (d, mean±SD)	3.1±0.8	3.1±0.9	3.1±0.6	0.805
Postoperative hospital stay (d, mean±SD)	7.5±1.2	7.6±1.4	7.4±1.0	0.610
Postoperative complication (%)	13 (14.4)	6 (12.0)	7 (17.5)	0.663

Table 3 Comparison of postoperative outcomes (first 50 patients vs last 40 patients)

	Operative time (min)	Open conversion	Transfusion requirement	Time to first flatus (d)	Hospital stay (d)	Complication (patients)
First 50 patients	251.3±47.3	1	3	3.1±0.9	7.6±1.4	7
Last 40 patients	197.0±27.7	1	2	3.1±0.6	7.4±1.0	6

P<0.0001