Oncologic safety of pylorus-preserving gastrectomy in the aspect of micrometastasis in lymph nodes at stations 5 and 6

Gastric Cancer Surgery: Balancing Oncological Efficacy against Postoperative Morbidity and Function Detriment

Significant progress has been made in the surgical management of gastric cancer over the years, and previous discrepancies in surgical practice between different parts of the world have gradually lessened. A transition from the earlier period of progressively more extensive surgery to the current trend of a more tailored and evidence-based approach is clear. Prophylactic resection of adjacent anatomical structures or neighboring organs and extensive lymph node dissections that were once assumed to increase the chances of long-term survival are now performed selectively. Laparoscopic gastrectomy has been widely adopted and its indications have steadily expanded, from early cancers located in the distal part of the stomach, to locally advanced tumors where total gastrectomy is required. In parallel, function-preserving surgery has also evolved and now constitutes a valid option for early gastric cancer. Pylorus-preserving and proximal gastrectomy have improved the postoperative quality of life of patients, and sentinel node navigation surgery is being explored as the next step in the process of further refining the minimally invasive concept. Moreover, innovative techniques such as indocyanine green fluorescence imaging and robot-assisted gastrectomy are being introduced in clinical practice. These technologies hold promise for enhancing surgical precision, ultimately improving the oncological and functional outcomes.

Sentinel Node Navigation Surgery for Early Gastric Cancer: A Narrative Review

Early gastric cancer (EGC) refers to malignant tumor lesions that are limited to the mucosa and submucosa layers, regardless of the presence of lymph node metastasis. Typically, EGC has a low rate of perigastric lymph node metastasis, and long-term survival outcomes are good after radical surgical treatment. The primary objective of surgical treatment for EGC is to achieve functional preservation while ensuring a radical cure. Sentinel node navigation surgery (SNNS) is a surgical technique used in the treatment of EGC. This approach achieves functional preservation by limiting lymph node dissection and performing restrictive gastrectomy guided by intraoperative negative sentinel node (SN) biopsy. Despite the apparent improvement in the detection rate of SN with the emergence of various tracing dyes and laparoscopic fluorescence systems, the oncological safety of SNNS remains a controversial research topic. SNNS, as a true form of stomach preservation surgery that enhances the quality of life, has become a topic of interest in the EGC field. In recent years, scholars from Japan and South Korea have conducted extensive research on the feasibility and safety of SNNS in the treatment of EGC. This article aims to provide reference choices for surgeons treating EGC by reviewing relevant research on SNNS for EGC in recent years.

Regional Lymph Node Metastasis Distribution in Resectable Middle-Third Gastric Cancer: A Cross-Sectional Study

Introduction Lymph node (LN) metastasis happens even in early gastric cancer (GC) even in LN stations that are not adjacent to the primary tumor. Total or subtotal gastrectomy (TG or sTG) can be performed in the middle third of the GC if the negative proximal margin is maintained. These procedures differed in the extent of LN dissection; therefore, oncology considerations must be taken into consideration when selecting the appropriate procedure. Methods This was a cross-sectional study involving 98 patients suffering from middle-third GC. The metastatic lymph nodes (mLN) ratio was calculated in each case by the ratio between the number of mLN and the number of total LNs retrieved. We compare the difference in the total LN retrieved, number of mLN, and rate of positive LN (N+) between the two groups TG and sTG. Results The majority of patients had advanced GC (82.7% pT2-4). About 65.3% of patients had metastasis LN. The events of LN metastasis and skipped LN metastasis happened even in tumors contained in the submucosal layer. The metastasis rates in each LN station were also increasing in correlation with the depth of tumor invasion. For LN station No. 2, 4sa, 10, 11d (which are not mandatory) in sTG, the rate of mLN was 0% for the pT1-3 tumor, regardless of tumor longitudinal location. The rate of mLN for each station was higher in adjacent stations of the tumor (No. 1-3-5-7 in lesser curvature, No. 4sb-4d-6 in greater curvature, No.1-3-4sb in the anterior wall, No. 3-7-12a in the posterior wall). The total LN retrieved, number of mLN, and rate of positive LN were statistically higher in the TG group compared to the sTG group. However, the mean mLN ratios between the two groups were comparable (p = 0.116). Conclusion In accordance with the macroscopic and microscopic characteristics, we observed a stratified distribution of mLN in the middle third of the GC. With these early results, sTG combined with standard lymphadenectomy was an acceptable treatment for T1-T3 middle-third GC in terms of mLN distribution. Total No. 4sb LN dissection might also be reserved in gastrectomy for T1-T3 GC.

Pathological and oncological outcomes of pylorus-preserving versus conventional distal gastrectomy in early gastric cancer: a systematic review and meta-analysis

Background

Pylorus-preserving gastrectomy (PPG) is a function-preserving surgery for the treatment of early gastric cancer (EGC) in the middle third of the stomach. According to the literature reports, PPG decreases the incidence of dumping syndrome, bile reflux, gallstone formation, and nutritional deficit compared with conventional distal gastrectomy (CDG). However, the debates about PPG have been dominated by the incomplete lymphadenectomy and oncological safety. We carried out a systematic review and meta-analysis to evaluate the pathological and oncological outcomes of PPG.

Methods

The protocol was registered in PROSPERO under number CRD42022304677. Databases including PubMed, Embase, Web of Science, and the Cochrane Register of Controlled Trials were searched before February 21, 2022. The outcomes included the pooled odds ratios (ORs) for dichotomous variables and weighted mean differences (WMDs) for continuous variables. For all outcomes, 95% confidence intervals (CIs) were calculated. Meta-analysis was performed using STATA software (Stata 14, Stata Corporation, Texas) and Review Manager 5.4.

Results

A total of 4500 patients from 16 studies were included. Compared with the CDG group, the PPG group had fewer lymph nodes harvested (WMD= −3.09; 95% CI −4.75 to −1.43; P < 0.001). Differences in the number of resected lymph nodes were observed at stations No. 5, No. 6, No. 9, and No. 11p. There were no differences in lymph node metastasis at each station. Shorter proximal resection margins (WMD = −0.554; 95% CI −0.999 to −0.108; P = 0.015) and distal resection margins (WMD = −1.569; 95% CI −3.132 to −0.007; P = 0.049) were observed in the PPG group. There were no significant differences in pathological T1a stage (OR = 0.99; 95% CI 0.80 to 1.23; P = 0.88), T1b stage (OR = 1.01; 95% CI 0.81 to 1.26; P = 0.88), N0 stage (OR = 0.97; 95% CI 0.63 to 1.48; P = 0.88), tumor size (WMD = −0.10; 95% CI −0.25 to 0.05; P = 0.187), differentiated carcinoma (OR = 1.04; 95% CI 0.74 to 1.47; P = 0.812) or signet ring cell carcinoma (OR = 1.22; 95% CI 0.90 to 1.64; P = 0.198). No significant differences were observed between the groups in terms of overall survival (HR = 0.63; 95% CI 0.24 to 1.67; P = 0.852) or recurrence-free survival (HR = 0.29; 95% CI 0.03 to 2.67; P = 0.900).

Conclusions

The meta-analysis of existing evidence demonstrated that the survival outcomes of PPG may be comparable to those of CDG. However, fewer lymph nodes at stations in No. 5, No. 6, No. 9, and No. 11p were harvested with PPG. We also found shorter proximal resection margins and distal resection margins for PPG, meaning more remnant stomachs would be preserved in PPG.

Modern surgical therapy for gastric cancer-Robotics and beyond

The surgical paradigm for gastric cancer has been changed from extended surgery to minimally invasive surgery. Laparoscopic surgery is a practical method for minimally invasive surgery for early gastric cancer, and the indication is expanding to advanced gastric cancer. In recent years, robotic gastrectomy has been highlighted as a breakthrough to overcome the drawbacks of laparoscopic gastrectomy. Here, we discuss the recent updates of modern surgical therapy for gastric cancer-robotics and beyond.

Feasibility of Preserving No. 5 and No. 6 Lymph Nodes in Gastrectomy of Proximal Gastric Adenocarcinoma: A Retrospective Analysis of 395 Patients

Objective

The extent of regional lymphadenectomy for proximal gastric cancer (PGC) has remained a controversy and a matter of considerable debate for a long time. We retrospectively analyzed the clinicopathological features to investigate the predictive factors for No. 5 and/or No. 6 lymph node metastases (LNMs) and evaluate the feasibility of performing proximal gastrectomy (PG) with preservation of No. 5 and/or No. 6 lymph nodes for these patients.

Method

Patients who had undergone total gastrectomy plus D2 lymphadenectomy in the Department of Gastrointestinal Surgery, Ruijin Hospital, Shanghai Jiao Tong University, School of Medicine, from January 2008 to December 2017 were retrospectively collected and analyzed.

Results

Among the 395 eligible patients in our study, 34 patients (8.61%) had No. 5 and No. 6 LNM. The degree of differentiation, Borrmann classification, vascular or perineural invasion, tumor diameter, depth of invasion, and other perigastric LNM were associated with No. 5 and/or No. 6 LNM. Multivariate analyses showed that tumor diameter ≥4 cm, No. 4 LNM positive, and No. 7, No. 8, No. 9 LNM positive were independent risk factors of No. 5 and/or No. 6 LNM. No. 5 and/or No. 6 LNM was not observed in the 105 patients who were staged from T1 to T3 and were found to be without independent risk factors.

Conclusion

The metastatic rate of No. 5 and/or No. 6 lymph node of the proximal gastric adenocarcinoma was closely associated with the diameter of the tumor and other perigastric LNMs. It is feasible to preserve No. 5 and No. 6 lymph nodes with PG for the T1-T3 patients with lower risk of No. 5 and/or No. 6 LNM.

Short-term Outcomes of Pylorus-Preserving Gastrectomy for Early Gastric Cancer: Comparison Between Extracorporeal and Intracorporeal Gastrogastrostomy

Purpose

This study aimed to compare the surgical and oncological outcomes between totally laparoscopic pylorus-preserving gastrectomy (TLPPG) with intracorporeal anastomosis and laparoscopy-assisted pylorus-preserving gastrectomy (LAPPG) with extracorporeal anastomosis.

Materials and Methods

A retrospective analysis was performed in 258 patients with cT1N0 gastric cancer who underwent laparoscopic pylorus-preserving gastrectomy using two different anastomosis methods: TLPPG with intracorporeal anastomosis (n=88) and LAPPG with extracorporeal anastomosis (n=170). The following variables were compared between the two groups to assess the postoperative surgical and oncological outcomes: proximal and distal margins, number of resected lymph nodes (LNs) in total and in LN station 6, operation time, postoperative hospital stay, and postoperative morbidity including delayed gastric emptying (DGE).

Results

The average length of the proximal margin was similar between the TLPPG and LAPPG groups (2.35 vs. 2.73 cm, P=0.070). Although the distal margin was significantly shorter in the TLPPG group than in the LAPPG group (3.15 vs. 4.08 cm, P=0.001), no proximal or distal resection margin-positive cases were reported in either group. The average number of resected LN was similar in both groups (36.0 vs. 33.98, P=0.229; LN station 6, 5.72 vs. 5.33, P=0.399). The operation time was shorter in the TLPPG group than in the LAPPG (200.17 vs. 220.80 minutes, P=0.001). No significant differences were observed between the two groups in terms of postoperative hospital stay (9.38 vs. 10.10 days, P=0.426) and surgical complication rate (19.3% vs. 22.9%), including DGE (8.0% vs. 11.8%, P=0.343).

Conclusions

The oncological safety and postoperative complications of TLPPG with intracorporeal anastomosis are similar to those of LAPPG with extracorporeal anastomosis.

Function-Preserving Gastrectomy for Early Gastric Cancer

Simple Summary

For patients with early gastric cancer (EGC), a good prognosis is achieved by conventional standard gastrectomy with radical lymphadenectomy. However, postgastrectomy syndrome is often inevitable and results in decreased quality of life (QOL). To improve patients’ QOL, proximal gastrectomy instead of total gastrectomy and pylorus-preserving gastrectomy instead of distal gastrectomy have been widely accepted as function-preserving gastrectomies. Recently, personalized, minimized gastrectomy with sentinel node navigation surgery has been developed and is expected to be an ideal treatment option for patients with EGC. Herein, we review the indications, surgical techniques, and postoperative outcomes of function-preserving gastrectomy.

Abstract

Recently, minimally invasive (endoscopic or laparoscopic) treatment for early gastric cancer (EGC) has been widely accepted. However, a standard gastrectomy with radical lymphadenectomy is generally performed in patients with EGC who have no indications for endoscopic resection, and postgastrectomy dysfunction is one of the problems of standard gastrectomy. Function-preserving gastrectomy, such as proximal gastrectomy and pylorus-preserving gastrectomy, can be considered when attempting to preserve the patient’s quality of life (QOL) postoperatively. In addition, sentinel node navigation surgery for EGC has been applied in clinical practice in several prospective studies on function-preserving personalized minimized gastrectomy. In the near future, the sentinel lymph node concept is expected to form the basis for establishing an ideal, personalized, minimally invasive function-preserving treatment for patients with EGC, which will improve their postoperative QOL without compromising their long-term survival. In this review article, we summarize the current status, surgical techniques, and postoperative outcomes of function-preserving gastrectomy for EGC.

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.

A comparison between pylorus-preserving and distal gastrectomy in surgical safety and functional benefit with gastric cancer: a systematic review and meta-analysis

BACKGROUND

Due to better functional outcomes, pylorus-preserving gastrectomy (PPG) has been widely applied for early gastric cancer (EGC) patients as an alternative to distal gastrectomy (DG). However, controversies still persist regarding the surgical efficacy and oncological safety of PPG.

METHODS

Original studies comparing PPG and DG for EGC were searched in PubMed, Embase, and the Cochrane Register of Controlled Trials up to December 2019. The weight mean difference, standardized mean difference, or odds risk was used to calculate the short-term and long-term outcomes between the two groups.

RESULTS

Twenty-one comparative studies comprising 4871 patients (1955 in the PPG group and 2916 in the DG group) were enrolled in this systematic review and meta-analysis. PPG showed longer hospital day, decreased harvested lymph nodes, and more delayed gastric emptying. However, PPG had the benefits of lower incidence of anastomosis leakage, early dumping syndrome, gastritis and bile reflux, and better recovery of total protein, albumin, hemoglobin, and weight. No difference was found in operative time, blood loss, and overall complications. Moreover, the long-term survival and recurrence rate were similar in two groups.

CONCLUSION

Owing to the non-inferiority of surgery and oncology outcomes and the superiority of function outcomes in PPG, we revealed that PPG can be clinically applicable instead of DG in EGC. However, more high-quality comparative studies and randomized clinical trials would be required for further confirmation.

Functional and nutritional outcomes after gastric cancer surgery

Recent improvements in diagnostic techniques and national screening programs have resulted in increasing number of patients diagnosed with early gastric cancer (EGC). The low incidence rate of lymph node metastasis and excellent survival rates after surgical treatment for EGC enabled the reduction in the extent of lymphadenectomy and the range of gastric resection for function-preserving gastrectomy. Thus, the quality of life (QOL) of patients with gastric cancer (GC) in the curative stage can be maintained. Moreover, these function-preserving procedures have been widely performed by less invasive procedures, such as laparoscopic and robotic approaches. Pylorus-preserving gastrectomy (PPG) and proximal gastrectomy (PG) represent the two main function-preserving surgical procedures for GC. PPG is an alternative to distal gastrectomy (DG) for cT1 N0 EGC located in the middle part of the stomach. Preservation of the pyloric function is expected to prevent post-gastrectomy syndromes such as dumping syndrome. PG is an alternative to total gastrectomy (TG) and can thus be performed for cT1 N0 EGC located in the upper part of the stomach. Preservation of the residual stomach is expected to work as a reservoir for ingested food. The optimal reconstruction method after PG among the three most commonly performed procedures (esophagogastrostomy, jejunal interposition, and double-tract reconstruction) remains controversial. In addition to these three reconstruction methods, the novel double-flap technique (DFT) of esophagogastrostomy has gained attention recently because of its potential usefulness to prevent postoperative esophageal reflux. In this review article, we summarize the current evidence of PPG and PG with esophagogastrostomy by the DFT, focusing on postoperative nutrition and QOL.

Patients' preoperative background causes gastric stasis after laparoscopy-assisted pylorus-preserving gastrectomy

INTRODUCTION

Despite technical improvements in laparoscopic gastrectomy, gastric stasis is still a serious problem in laparoscopy-assisted pylorus-preserving gastrectomy (LAPPG). The aim of this study was to investigate the factors that might cause gastric stasis in LAPPG.

METHODS

From April 2004 through November 2012, 85 patients with cT1N0 middle-third gastric cancer who underwent LAPPG at Kitasato University Hospital; these patients were included in the present study. Infra-pyloric vein (IPV)-preserving LAPPG was performed in 41 patients. We compared the rate of gastric stasis in the IPV-preserving and the IPV-non-preserving groups, and analyzed the clinicopathological factors that might have caused gastric stasis.

RESULTS

We did not demonstrate that preservation of the IPV could prevent gastric stasis in the early and late postoperative periods. Symptoms of gastric stasis were most frequently recognized 1 year after surgery. A significantly higher proportion of preoperative ASA class 2 patients had gastric stasis than did not (80.0% [12/15] vs 48.6% [34/70], P=0.02). Among the ASA class 2 patients, a significantly greater proportion of those with depressed activities of daily living than those with normal activities of daily living had gastric stasis (66.7% [4/6] vs 20.0% [8/40], P = 0.015).

CONCLUSIONS

The clinical significance of the IPV preservation in LAPPG could not be demonstrated. LAPPG should be performed for ASA class 1 patients or those with maintained preoperative activities of daily living.

Perioperative outcomes of laparoscopy-assisted pylorus and vagus nerve-preserving gastrectomy and distal gastrectomy for middle-third early gastric cancer

AIM

To compare the surgical safety, postoperative compli-cations and hospitalization expenses of laparoscopy-assisted pylorus and vagus nerve-preserving gastrectomy (LAPPG) and distal gastrectomy (LADG) in order to evaluate the feasibility of LAPPG in the treatment of middle-third early gastric cancer.

METHODS

The clinical and pathological data, surgical procedure, postoperative outcomes and hospitalization expenses of 112 patients with middle-third early gastric cancer treated from June 2016 to August 2017 at Department of Gastrointestinal Surgery of Renji Hospital were analyzed retrospectively. Forty-six patients received LAPPG, and 66 cases underwent LADG.

RESULTS

There were no significant differences between the two groups in age, sex, BMI, tumor differentiation, operative time, estimated blood loss, tumor diameter, resected lymph nodes, or metastatic lymph nodes (P > 0.05). Proximal and distal resection margins were significantly shorter in the LAPPG group than in the LADG group (P < 0.05). For postoperative outcomes, there were no significant differences in hospital stay, time to first flatus, time to gastric tube removal, time to first ambulation, time to first fluid diet, or postoperative complications (≥Dindo grade Ⅱ) (P > 0.05). Hospitalization expense of LAPPG was significantly lower than that of LADG [4.6 ± 0.5 vs 5.3 ± 0.4 (ten thousand yuan), P = 0.004].

CONCLUSION

On the premise of oncologic safety and efficacy, LAPPG is a cost-effective and feasible treatment for middle-third early gastric cancer.

Preservation of the celiac branch of the vagal nerve for pylorus-preserving gastrectomy: is it meaningful?

BACKGROUND

Preserving the hepatic and pyloric branches of the vagal nerve in laparoscopic pylorus-preserving gastrectomy (LPPG) is considered necessary to maintain the function of the pyloric cuff. However, the clinical benefits of preservation of the celiac branch of the vagal nerve (CBVN) remain unclear.

METHODS

Of 391 patients who underwent LPPG for early gastric cancer, 116 patients in whom the CBVN was preserved (CBP group) and 58 patients in whom it was not preserved (non-CBP group) were selected through the propensity score-matching method. To evaluate the surgical and oncological safety of preserving the CBVN, postoperative morbidity and mortality were analyzed between these matched groups. Postoperative nutritional status, body weight changes, endoscopic findings, and the incidence of gallstones were compared to evaluate any functional advantages.

RESULTS

The short-term surgical outcomes in the CBP group were similar to those in the non-CBP group. The number of dissected lymph nodes did not differ (34 vs. 33.5, P = 0.457), and the 5-year recurrence-free survival rates were also similar between both groups (99.1% vs. 97.1%, P = 0.844). There were no significant differences in postoperative nutritional status, body weight changes, or the incidence of gallstones. By endoscopy, 1 year after surgery residual food was frequently observed in both groups; however, there were no significant differences in the frequency of remnant gastritis and esophageal and bile reflux.

CONCLUSIONS

Preserving CBVN in LPPG for early gastric cancer is a feasible procedure. However, no clinical benefits of the preservation of the CBVN after LPPG are identified.

Function-preserving surgery for gastric cancer: current status and future perspectives

The number of early gastric cancer (EGC) cases has been increasing because of improved diagnostic procedures including endoscopy and screening systems. Therefore, function-preserving gastrectomy (FPG) for EGC with the expectation of better quality of life (QOL) after surgery may be increasingly utilized, due to its association with low rate of lymph node metastasis and excellent survival and the possibility of employing less invasive procedures such as laparoscopic gastrectomy in combination. Pylorus-preserving gastrectomy (PPG) with curative intent lymph node dissection is a representative FPG that has been used in EGC, and its superiorities, indications, limitations, and survival benefits have already been reported in several retrospective studies. Laparoscopic proximal gastrectomy (LAPG) has also been employed in EGC of the upper third of the stomach; however, LAPG was found to be associated with major issues in achieving a balance between swallowing and reflux prevention. In patients with EGC in the upper third of the stomach, laparoscopy-assisted subtotal gastrectomy with a preserved, albeit very small, stomach may provide a better QOL and fewer postoperative complications. FPG is recommended as a surgical treatment for EGC if the indication is accurately diagnosed and strictly confirmed; however, these techniques in laparoscopic surgery present technical difficulties to surgeons without a certain degree of skills. Although many retrospective studies revealed the functional benefits or oncological safety with FPG, further prospective studies using large case series are necessary to reveal the value of FPG compared with the conventional procedures.

Oncological outcomes of function-preserving gastrectomy for early gastric cancer: a multicenter propensity score matched cohort analysis comparing pylorus-preserving gastrectomy versus conventional distal gastrectomy

OBJECTIVE

This study aimed to clarify the oncological safety of pylorus-preserving gastrectomy (PPG) compared with conventional distal gastrectomy (DG).

METHODS

From three institutions specializing in cancer, the medical records for a cohort of 2898 consecutive patients who had undergone DG (n = 2208) or PPG (n = 690) for clinical stage I gastric cancer between January 2006 and December 2012 were analyzed. A propensity score for each patient was estimated on the basis of 38 preoperative clinical and tumor-related factors. After propensity score matching had been done, 1004 patients (502 DG patients, 502 PPG patients) were included in the analysis. The overall survival, relapse-free survival, and occurrence of secondary gastric cancer were then compared. The median observation period was 48.6 months (range 1-109.8 months).

RESULTS

The 5-year overall survival rate was 98.4 % for the PPG group and 96.6 % for the DG group (hazard ratio 0.48, 95 % confidence interval 0.21-1.09, P = 0.07). The 3-year relapse-free survival rate was 99.5 % for the PPG group and 98.0 % for the DG group (hazard ratio 0.39, 95 % confidence interval 0.12-1.33, P = 0.12). Postoperative secondary gastric cancer was encountered in eight patients (1.6 %) in the PPG group and four patients (0.8 %) in the DG group. No significant differences in either overall survival, relapse-free survival, or the occurrence of secondary gastric cancer were observed between the two groups.

CONCLUSIONS

Given the adequate estimation of the clinical tumor stage, the oncological safety of PPG for clinical T1N0 gastric cancer in the middle portion of the stomach was comparable to that of DG.

Lymphadenectomy along the infrapyloric artery may be dispensable when performing pylorus-preserving gastrectomy for early middle-third gastric cancer

This study investigated the incidence of gastric cancer metastasis to the lymph nodes along the infrapyloric artery (IPA), namely no. 6i, by reviewing our medical records of 348 patients who underwent complete no. 6 dissection. Metastasis to these nodes was observed in 11 (3.2 %) patients. In these patients, one huge tumor was located in the middle third and ten including two early tumors were located in the lower third; the metastasis rate in early lower-third tumors was 2.1 % and reached 19.5 % in advanced tumors. In contrast, no early middle-third gastric cancers had no. 6i metastasis. The median diameter of 6i-positive tumors was 62 (range 18-115) mm, and the distance from the distal tumor border to the pyloric ring was no more than 44 mm. Lymphadenectomy along the IPA is important for treating gastric cancer invading the antrum, but may be dispensable when performing pylorus-preserving gastrectomy for early middle-third cancer.

Excellent Long-Term Prognosis and Favorable Postoperative Nutritional Status After Laparoscopic Pylorus-Preserving Gastrectomy

BACKGROUND

Laparoscopic pylorus-preserving gastrectomy (LPPG) has been introduced as a minimally invasive function-preserving operation for early gastric cancer (GC). This study aimed to investigate the surgical and prognostic outcomes after LPPG at the authors' institution.

METHODS

This study analyzed 465 patients who underwent LPPG for cT1 N0 GC located in the middle part of the stomach between 2006 and 2012. Short- and long-term surgical outcomes including 5-year survival rates, postoperative nutritional data, and body weight change were retrospectively investigated.

RESULTS

Regarding short-term surgical results, 14 (3%) of the 465 patients had severe complications classified as Clavien-Dindo grade 3a or above, and no mortality occurred (no in-hospital deaths). The median follow-up period was 1829 days (range 226-3197 days), and the 5-year overall survival and relapse-free survival rates were respectively 98% (95% confidence interval [CI] 96.1-99.0%) and 98% (95% CI 96.1-99.0%). Only two cases of postoperative recurrence were confirmed, and their recurrence sites were not in the remnant stomach or regional lymph nodes. The postoperative nutritional status, in terms of serum total protein, albumin, and hemoglobin levels, was well maintained, and the mean relative body weight (postoperative/preoperative) was 93.24 ± 7.29% after LPPG.

CONCLUSIONS

For the first time, we have clarified the detailed long-term survival outcomes of LPPG for cT1 N0 GC. LPPG is an acceptable and favorable operative method for clinically diagnosed early-stage GC, in terms of long-term survival and postoperative nutrition.

Minimally invasive surgery for gastric cancer treatment: current status and future perspectives

Minimally invasive surgery, which has been extensively used to treat gastric adenocarcinoma, is now regarded as one of the standard treatments for early gastric cancer, and its suitability for advanced gastric cancer is being investigated. The use of cutting-edge techniques for minimally invasive surgery enables surgeons to deliver various treatment options to minimize a patient's distress and to maintain oncologic safety. Ongoing multicenter prospective studies aim to validate the efficacy of these surgical techniques and to expand the indications of minimally invasive surgery for the treatment of gastric cancer. In this review, we summarize the current status and issues regarding minimally invasive surgery for the treatment of gastric cancer.

Current status of function-preserving surgery for gastric cancer

Recent advances in diagnostic techniques have allowed the diagnosis of gastric cancer (GC) at an early stage. Due to the low incidence of lymph node metastasis and favorable prognosis in early GC, function-preserving surgery which improves postoperative quality of life may be possible. Pylorus-preserving gastrectomy (PPG) is one such function-preserving procedure, which is expected to offer advantages with regards to dumping syndrome, bile reflux gastritis, and the frequency of flatus, although PPG may induce delayed gastric emptying. Proximal gastrectomy (PG) is another function-preserving procedure, which is thought to be advantageous in terms of decreased duodenogastric reflux and good food reservoir function in the remnant stomach, although the incidence of heartburn or gastric fullness associated with this procedure is high. However, these disadvantages may be overcome by the reconstruction method used. The other important problem after PG is remnant GC, which was reported to occur in approximately 5% of patients. Therefore, the reconstruction technique used with PG should facilitate postoperative endoscopic examinations for early detection and treatment of remnant gastric carcinoma. Oncologic safety seems to be assured in both procedures, if the preoperative diagnosis is accurate. Patient selection should be carefully considered. Although many retrospective studies have demonstrated the utility of function-preserving surgery, no consensus on whether to adopt function-preserving surgery as the standard of care has been reached. Further prospective randomized controlled trials are necessary to evaluate survival and postoperative quality of life associated with function-preserving surgery.

Meta-analysis of pylorus-preserving gastrectomy for middle-third early gastric cancer

BACKGROUND

Pylorus-preserving gastrectomy (PPG) has been performed to reduce postprandial symptoms for some early gastric cancer (EGC) cases. The aim of this study was to evaluate the possible advantages after PPG for middle-third EGC in comparison with distal gastrectomy.

MATERIALS AND METHODS

We searched Medline, Embase, and Science Citation Index Expanded for relevant studies. Statistical analyses were conducted to calculate the summary weighted mean differences (WMDs) and odds ratios (ORs) with corresponding 95% confidence intervals (95% CIs) using random-effects models.

RESULTS

We identified 15 nonrandomized controlled trials (16 studies) with 1774 patients, which consisted of 11 studies for conventional PPG (CPPG) versus conventional distal gastrectomy (CDG) and 5 studies for laparoscopy-assisted PPG (LAPPG) versus laparoscopy-assisted distal gastrectomy (LADG). Meta-analysis of CPPG versus CDG revealed that CPPG had the advantage of prevention of early dumping syndrome (OR=0.18; 95% CI 0.12, 0.27), gastritis (OR=0.19; 95% CI 0.07, 0.53), duodenal juice reflux (OR=0.20; 95% CI 0.06, 0.66), and regaining of weight (WMD=3.53; 95% CI 2.34, 4.72). However, the incidence of gastric stasis was higher in the CPPG group than in the CDG group (OR=1.70; 95% CI 1.13, 2.57). Meta-analysis of LAPPG versus LADG revealed that LAPPG shortened the operation time (WMD=-21.12; 95% CI -31.33, -10.90) and did not increase the occurrence of postoperative complication (OR=0.72; 95% CI 0.41, 1.27).

CONCLUSIONS

With the benefits of prevention of early dumping syndrome, duodenal juice reflux, gastritis, and regaining of weight, PPG can be an excellent option for middle-third EGC.