We retrospectively reviewed the prospective database of patients who underwent laparoscopic proximal gastrectomy for clinical stage I gastric cancer located in the upper one-third of the stomach from two large-volume hospitals in Korea. From December 2013 to June 2017, a total of 67 and 50 patients underwent laparoscopic proximal gastrectomy in the National Cancer Center and the Kyungpook National University Chilgok Hospital, respectively. Among them, we excluded 14 patients who were diagnosed as stage II or more in the pathological reports, and 103 patients were finally included in the analysis. No patients included in this study received adjuvant chemotherapy after operation.
The Institutional Review Board of the National Cancer Center (NCC2017-0120) and the Kyungpook National University Chilgok Hospital (2019-07-004) approved this study and waived the need for patient informed consent due to the retrospective nature of the study.
In the laparoscopic proximal gastrectomy, five working ports were inserted into the umbilicus (12mm), right upper quadrant (5mm), right lower quadrant (12mm), left upper quadrant (5mm), and left lower quadrant (5mm). D1+ lymph node dissection was performed according to the Japanese gastric cancer treatment guidelines, including lymph node stations 1, 2, 3a, 4sa, 4sb, 7, 8a, 9, and 11p. The right gastroepiploic artery and right gastric artery were saved to preserve blood supply to the remnant distal stomach. The hepatic branch of the vagus nerve was also preserved to maintain pyloric function. After confirming the tumor-negative resection margins in the frozen examination, reconstruction was performed.
In EG, we had two types of anti-reflux procedures in consecutive order. In the initial period (2013-2016), anchoring the gastric wall to the diaphragm was added to the conventional EG to create a neo-His angle and fundus. In the last period (2017), two interrupted sutures were performed to make an artificial His angle between the distal part of the esophagus’s posterior wall and the proximal portion of the stomach’s anterior wall. Then, the esophageal stump and stomach wall were opened, and anastomosis was performed with continuous hand-sewn sutures between the esophagus and stomach.
In the double-tract reconstruction, the linear-stapled jejuno-jejunal and gastrojejunal anastomoses were performed extracorporeally via mini-laparotomy. Then, intracorporeal esophagojejunostomy was performed using an endo-linear stapler via the overlap method. The distances between the esophagojejunostomy and both the gastrojejunostomy and the jejunojejunostomy were estimated at 15 cm and 20 cm, respectively.
Baseline data collection
We reviewed medical records to collect data on patient demographics and pathological characteristics. Comorbidity was evaluated using the American Society of Anesthesiologists (ASA) physical status classification system, and histological types were classified according to the 2010 World Health Organization (WHO) classification [15, 16]. When a tumor consisted of two or more histological types, the quantitative predominance was recorded as the histological type. The pathological stage was categorized according to the 8th American Joint Committee on Tumor-Node-Metastasis (TNM) classification system .
Patients followed up every 6 months after surgery for 5 years. Each follow-up visit included measurement of body weight, laboratory tests, and a quality of life (QOL) assessment. Esophagogastroduodenoscopy was performed annually following surgery.
Laboratory tests included complete blood cell count, blood chemistry, and liver function testing. Serum ferritin, iron, and vitamin B12 levels have been checked periodically since 2015 and are tested annually to monitor for the development of iron deficiency anemia and vitamin B12 deficiency. Anemia was defined as a hemoglobin level < 13 g/dL in men and < 12 g/dL in women, based on World Health Organization criteria . Iron deficiency was defined as a serum ferritin level < 30ng/mL, and vitamin B12 deficiency as a serum vitamin B12 level < 200 pg/mL [19, 20].
The presence of esophageal reflux was evaluated at the 1-year follow up via endoscopic examination, and the severity was classified according to the Los Angeles (LA) classification: LA grade A, one or several erosions limited to the mucosal folds and no larger than 5mm in size; LA grade B, one or several erosions limited to the mucosal folds and larger than 5mm in size; LA grade C, erosion extending over mucosal folds, but over less than three-quarters of the circumference; and LA grade D, confluent erosions extending over more than three-quarters of the circumference. . Esophageal stricture usually occurs within several months after surgery, and patients experience dysphagia. We reviewed all endoscopic examination results performed postoperatively within 1-year and divided the patients into 3 groups: patients without any stricture, patients with mild stricture but no need for intervention, and patients who underwent endoscopic interventions such as balloon dilatation for severe stricture.
A QOL survey was performed in patients who visited the outpatient clinic for routine check-ups. QOL was assessed using the validated Korean version of the gastric cancer-specific module of the European Organization for Research and Treatment of Cancer (EORTC QLQ-STO22) [22, 23] The EORTC QLQ-STO22 is composed of 9 symptom scales, and each scale is represented by a score ranging from 0 to 100; a higher score indicates a poorer QOL. The results of the QOL survey obtained preoperatively and 1-year postoperatively were included in the analyses.
The continuous variables are shown as the means ± standard deviations or the medians with interquartile ranges, and the categorical variables are presented as proportions. Differences between two groups were tested using a t-test or the Wilcoxon rank-sum test for continuous variables and the one-way analysis of variance (ANOVA) or Kruskal-Wallis test was used for differences among three groups. The chi-square test or Fisher’s exact test was used for categorical variables. A mixed-effect model was performed to analyze changes in the nutritional outcomes over time between the two groups.
In the QOL analysis, each subscale or item is presented as the median and the interquartile range. Nonparametric statistics (i.e., the Willcoxon rank-sum test) were used to evaluate their statistical significance because the distribution of QOL scores did not follow a normal distribution.
Data analyses were conducted using SAS version 9.4 (SAS Institute Inc., Cary, NC). P-values less than 0.05 were considered significant.