Size-dependent differences in the proximal remnant stomach: how much does a small remnant stomach after subtotal gastrectomy work?

Laparoscopic Function-Preserving Gastrectomy for Proximal Gastric Cancer or Esophagogastric Junction Cancer: A Narrative Review

Function-preserving procedures to maintain postoperative quality of life are an important aspect of treatment for early gastric cancer. Laparoscopic proximal gastrectomy (LPG) and laparoscopic distal gastrectomy with a small remnant stomach, namely laparoscopic subtotal gastrectomy (LsTG), are alternative function-preserving procedures for laparoscopic total gastrectomy of early proximal gastric cancer. In LPG, esophagogastrostomy with techniques to prevent reflux and double-tract and jejunal interposition including esophagojejunostomy is usually chosen for reconstruction. The double-flap technique is currently a preferred reconstruction technique in Japan as an esophagogastrostomy approach to prevent reflux esophagitis. However, standardized reconstruction methods after LPG have not yet been established. In LsTG, preservation of the esophagogastric junction and the fundus prevents reflux and malnutrition, which may maintain quality of life. However, whether LsTG is an oncologically and nutritionally acceptable procedure compared with laparoscopic total gastrectomy or LPG is a concern. In this review, we summarize the status of reconstruction in LPG and the oncological and nutritional aspects of LsTG as a function-preserving gastrectomy for early proximal gastric or esophagogastric junction cancer.

Cardia function-preserving surgery and anti-reflux anastomotic method after proximal gastrectomy for gastric cancer: Current status and future perspectives

The incidence and mortality of gastric cancer ranked 5th and 3rd worldwide, respectively, in 2018, and the incidence of gastroesophageal junction adenocarcinoma increased over the past 40 years. Radical resection and lymph node dissection is the preferred treatment for gastric cancer. Proximal gastrectomy or total gastrectomy is usually performed for gastroesophageal junction adenocarcinoma and upper gastric cancer. Owing to the resection of the cardia structures, the incidence of reflux esophagitis increases significantly after proximal gastrectomy and total gastrectomy, resulting in poor postoperative quality of life. To reduce the incidence of reflux esophagitis and improve patients' postoperative quality of life, various methods to preserve the function of the cardia or to perform anti-reflux reconstruction have emerged. In this manuscript, we systematically introduced the advantages and problems of various anti-reflux anastomotic method after proximal gastrectomy, and cardia-preserving gastrectomy including endoscopic resection (ER), local gastrectomy by gastroscopy combined with laparoscopy, segmental gastrectomy, subtotal gastrectomy, and cardia-preserving radical gastrectomy. Cardia-preserving radical gastrectomy has the advantage of more thorough lymph node dissection and wider indications than those for subtotal gastrectomy. However, the clinical efficacy of cardia-preserving radical gastrectomy requires verification in prospective and controlled clinical trials. Cardia-preserving radical gastrectomy is a promising approach as one of the more reasonable anti-reflux surgeries.

Minimum resection length to ensure a pathologically negative distal margin and the preservation of a larger remnant stomach in proximal gastrectomy for early upper gastric cancer

BACKGROUND

In proximal gastrectomy (PG), a longer distal margin (DM) length should be maintained to obtain a pathologically negative DM. However, a shorter DM length is preferred to preserve a large remnant stomach for favorable postoperative outcomes. Evidence regarding the minimum DM length to ensure a pathologically negative DM is useful.

METHODS

Patients who underwent PG or total gastrectomy for cT1N0M0 gastric cancer limited to the upper third were enrolled. A new parameter, ΔDM, which corresponded to the pathological extension distal to the gross tumor boundary towards the resection stump, was evaluated. The maximum ΔDM, which is the length ensuring a pathologically negative DM, was first determined. Furthermore, the possible incidences of pathologically positive DM were calculated for each pathological type and clinical tumor (cTumor) size.

RESULTS

Of 361 patients eligible for this study, 190 and 171 were assigned to differentiated (Dif) and undifferentiated types (Und), respectively. The maximum ΔDM was 30 and 40 mm in Dif and Und, respectively. Considering a correlation between cTumor size and ΔDM, and possible incidences of pathologically positive DM, 10, 20, and 30 mm were the minimal gross DM lengths in Dif when cTumor size was ≤ 15 mm, > 15 and ≤ 50 mm, and > 50 mm, respectively. In Und, the incidences of pathologically positive DM were 0.59% and 2.3% for gross DM lengths of 30 and 20 mm, respectively.

CONCLUSION

The minimum DM lengths to ensure a pathologically negative DM in PG are proposed according to the pathological type of early upper gastric cancer.

Long-term effect of simplified dietary education on the nutritional status of patients after a gastrectomy

Dietary education is regarded as an important and useful tool for influencing nutritional status. Since long, dietary education has been performed to improve the nutritional status of patients after a gastrectomy. This study aimed to investigate the effect of simplified dietary education on the nutritional status of patients after a gastrectomy. A total of 1,150 patients with gastric cancer underwent surgery between March 2014 and October 2015 at the Samsung Medical Center (SMC). Of these, we used the case-control matching method (1:1 match) by stratifying the factors of age and sex and included 100 patients in each group. The clinicopathologic data of the patients for two years after the gastrectomy were prospectively collected and retrospectively analyzed. The educated group (ED, N = 100) was provided with a simplified, ordinary dietary education at regular outpatient clinic visits that occurred at 1, 3, 6, and 12 months after gastrectomy and at 1-year intervals thereafter. The clinicopathologic characteristics and nutritional parameters of the educated group (ED) (N = 100) and the non-educated group (NED) (n = 100) were compared. There were no significant differences between the two groups in terms of clinical characteristics and serological parameters. Nutritional parameters, which included body weight loss, body mass index (BMI) change, and prognostic nutritional index (PNI), were also not significantly different between the two groups. Simplified dietary education at regular outpatient clinic visits was ineffective in reducing weight loss after a subtotal gastrectomy. Further research or other methods may be needed to reduce weight loss after a gastrectomy.

Current status of function-preserving gastrectomy for gastric cancer

Early gastric cancer (EGC) has excellent postoperative survival outcomes; thus, one of the recent keywords in the treatment of EGC is "function-preserving gastrectomy (FPG)." FPG reduces the extent of lymphadenectomy and gastric resection without compromising the long-term prognosis. Proximal gastrectomy (PG) is an alternative to total gastrectomy (TG) for EGC in the upper-third of the stomach, in which the gastric reservoir, gastric acid secretion, and intrinsic factors are maintained. Distal gastrectomy (DG) with a small remnant stomach, namely subtotal gastrectomy (STG), is another option for upper EGC, where the function of the cardia and fundus is preserved. Pylorus-preserving gastrectomy (PPG) is a good alternative to DG for EGC in the middle-third of the stomach, where pyloric function is preserved. Following elucidation of the markedly low incidences of possible metastasis to lymph node stations where dissection is omitted, the oncological safety of these FPG procedures was clarified. Nutritional advantages of PG or STG over TG have been reported; however, the standardized reconstruction methods after PG are yet to be established, and it is important to devise methods to prevent postoperative gastroesophageal reflux and anastomotic complications regardless of the reconstruction method. Nutritional benefits of PPG compared with DG have also been clarified, in which reducing postoperative gastric stasis is important. For the further spread of these FPG procedures, several issues, such as precise evaluation of preserved function, confirmation of oncological safety, and standardization of the technique, should be addressed in future prospective randomized controlled trials.