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Yuu et al. Mini-invasive Surg 2019;3:6 I http://dx.doi.org/10.20517/2574-1225.2018.73 Page 3 of 9

Table 1. Patient demographics of the LDG group and ODG group
Variable LDG group (n = 20) ODG group (n = 40) P value
Age (years) 81.0 ± 5.0 81.4 ± 3.9 0.289
Sex, F/M 5/15 13/27 1
BMI 22.3 ± 3.4 21.4 ± 3.0 0.289
ASA 0.551
1 2 3
2 15 25
3 3 12
Hugh-Jones classification 0.117
1 12 13
2 7 16
3 1 9
4 0 2
Previous surgeries 9 9 0.134
CCI 0.566
0 5 6
1 7 10
2 7 16
3 1 6
4 0 2
ASA: American Society of Anesthesiology; BMI: body mass index; CCI: Charlson comorbidity index; LDG: laparoscopic distal gastrectomy;
ODG: open distal gastrectomy

are especially critical in elderly patients, were included in the analysis.

This study was approved by the institutional review board of the Bell Land General Hospital. The study
protocol conformed to the principles set in the Declaration of Helsinki and its later amendments.

All statistical analysis were performed with EZR (Saitama Medical Center, Jichi Medical University; http://
www.jichi.ac.jp/saitama-sct/SaitamaHP.files/statmedEN.html; Kand, 2012), which is a graphical user
interface for R (version 2.13.0; The R Foundation for Statistical Computing, Vienna, Austria) .
[15]

The characteristics of both groups were compared using the chi-squared and Mann-Whitney U tests. The
postoperative survival was analyzed using Kaplan-Meier survival curves and compared with the log-rank
test. Significance was established at P < 0.05. As the number of patients older than 75 years are low, the
sample size of the present study was small. Therefore, we used non-parametric statistical methods.

RESULTS
Patient characteristics
Patient characteristics are shown in Table 1. There were 20 patients in the LDG group and 40 in the ODG
group with mean ages of 81.0 ± 5.0 and 81.4 ± 3.9 years, respectively. No significant differences were
observed in terms of sex, BMI, ASA classification, previous surgery, or CCI. Since decreased respiratory
function is a major risk factor for postoperative pulmonary complications in the elderly, previous studies
commonly assessed the predicted functional expiratory volume in 1 s, predicted vital capacity, or arterial
oxygen saturation [16,17] . In this study, we used the Hugh-Jones classification to assess respiratory function ,
[18]
and no differences were observed between the two groups. The prevalence of comorbidity was high in both
groups; only 25.0% of the patients in the LDG group (n = 5) and 15.0% of those in the ODG group (n = 6)
had no preoperative comorbidity (CCI = 0).

The surgical procedure and early surgical outcomes are summarized in Table 2. A Billroth I anastomosis
was performed in 12 patients in the LDG group and in 18 in the ODG group, while a Roux-en-Y
anastomosis was performed in 8 and 20 patients, respectively. The remaining patients in the ODG group
underwent a Billroth II anastomosis. There were no conversions to open surgery in the LDG group. D2
lymph node dissection was performed in 15 patients in the LDG group and in 26 patients in the ODG