The safety of the dissection of lymph node stations 5 and 6 in pylorus-preserving gastrectomy

A Comparative Study of Postoperative Complications Associated with Distal Gastrectomy and Pylorus-Preserving Gastrectomy among Gastric Cancer Patients Based on Nationwide Survey Data and Propensity Score Weighting

BACKGROUND/OBJECTIVE

This study aimed to compare complication rates between pylorus-preserving gastrectomy (PPG) and distal gastrectomy (DG) using Korean nationwide survey data and propensity score weighting (PSW). PPG preserves gastric function but may lead to more postoperative complications than DG.

METHODS AND RESULTS

We analyzed 9424 gastric cancer patients who underwent either DG (n = 9183) or PPG (n = 241). PSW balanced variables such as age, sex, TNM stage, comorbidities, ASA score, and surgical approach. Before PSW, 87.8% of DG patients and 87.1% of PPG patients had no complications (p = 0.053). Severe complications (Clavien-Dindo IIIa or higher) were more frequent in PPG (6.6%) than in DG (3.8%) (p = 0.039). After PSW, overall complication rates (p = 0.960) and severe complication rates (p = 0.574) were similar between groups. Incidence rates of anastomotic stricture and leakage were higher in PPG (2.9% and 1.7%) compared to DG (0.6% and 0.5%) (p = 0.001 and 0.036) before PSW, but these differences were not significant after PSW (p = 0.999 and 0.123).

CONCLUSION

The PSW-adjusted analysis indicates no significant difference in overall and severe complication rates between PPG and DG in gastric cancer patients.

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.

Preservation of the celiac branch of the vagus nerve reduces the incidence of postoperative diarrhea in gastric cancer: a cohort study

BACKGROUND

To investigate the short-term and long-term outcomes of preserving the celiac branch of the vagus nerve during laparoscopic distal gastrectomy.

METHODS

A total of 149 patients with prospective diagnosis of gastric cancer who underwent laparoscopic-assisted distal gastrectomy (LADG) combined with Billroth-II anastomosis and D2 lymph node dissection between 2017 and 2018 were retrospectively analyzed. The patients were divided into the preserved LADG group (P-LADG, n = 56) and the resected LADG group (R-LADG, n = 93) according to whether the vagus nerve celiac branch was preserved. We selected 56 patients (P-LADG, n = 56) with preservation of the celiac branch of the vagus nerve and 56 patients (R-LADG, n = 56) with removal of the celiac branch of the vagus nerve by propensity-matched score method. Postoperative nutritional status, weight change, short-term and long-term postoperative complications, and gallstone formation were evaluated in both groups at 5 years of postoperative follow-up. The status of residual gastritis and bile reflux was assessed endoscopically at 12 months postoperatively.

RESULTS

The incidence of diarrhea at 5 years postoperatively was lower in the P-LADG group than in the R-LADG group (p < 0.05). In the multivariate logistic analysis, the removal of vagus nerve celiac branch was an independent risk factor for the occurrence of postoperative diarrhea (odds ratio = 3.389, 95% confidential interval = 1.143-10.049, p = 0.028). In the multivariate logistic analysis, the removal of vagus nerve celiac branch was an independent risk factor for the occurrence of postoperative diarrhea (odds ratio = 4.371, 95% confidential interval = 1.418-13.479, p = 0.010).

CONCLUSIONS

Preservation of the celiac branch of the vagus nerve in LADG reduced the incidence of postoperative diarrhea postoperatively in gastric cancer.

TRIAL REGISTRATION

This study was registered with the Ethics Committee of the First Affiliated Hospital of Dalian Medical University in 2014 under the registration number: LCKY2014-04(X).

Surgery Matters: Progress in Surgical Management of Gastric Cancer

OPINION STATEMENT

The surgical treatment of gastric carcinoma has progressed significantly in the past few decades. A major milestone was the establishment of multimodal therapies for locally advanced tumours. Improvements in the technique of endoscopic resection have supplanted surgery in the early stages of many cases of gastric cancer. In cases in which an endoscopic resection is not possible, surgical limited resection procedures for the early stages of carcinoma are an equal alternative to gastrectomy in the field of oncology. Proximal gastrectomy is extensively discussed in this context. Whether proximal gastrectomy leads to a better quality of life and better nutritional well-being than total gastrectomy depends on the reconstruction chosen. The outcome cannot be conclusively assessed at present. For locally advanced stages, total or subtotal gastrectomy with D2 lymphadenectomy is now the global standard. A subtotal gastrectomy requires sufficiently long tumour-free proximal resection margins. Recent data indicate that proximal margins of at least 3 cm for tumours with an expansive growth pattern and at least 5 cm for those with an infiltrative growth pattern are sufficient. The most frequently performed reconstruction worldwide following gastrectomy is the Roux-en-Y reconstruction. However, there is evidence that pouch reconstruction is superior in terms of quality of life and nutritional well-being. Oncological gastric surgery is increasingly being performed laparoscopically. The safety and oncological equivalency were first demonstrated for early carcinomas and then for locally advanced tumours, by cohort studies and RCTs. Some studies suggest that laparoscopic procedures may be advantageous in early postoperative recovery. Robotic gastrectomy is also increasing in use. Preliminary results suggest that robotic gastrectomy may have added value in lymphadenectomy and in the early postoperative course. However, further studies are needed to substantiate these results. There is an ongoing debate about the best treatment option for gastric cancer with oligometastatic disease. Preliminary results indicate that certain patient groups could benefit from resection of the primary tumour and metastases following chemotherapy. However, the exact conditions in which patients may benefit have yet to be confirmed by ongoing trials.

Safety of pylorus-preserving gastrectomy for gastric cancer combined with antral high-risk lesions: a comparison with endoscopic submucosal dissection

BACKGROUND

Pylorus-preserving gastrectomy (PPG) is a surgical treatment option for cT1N0M0 gastric cancer located in the middle third of the stomach. However, data for the long-term post-PPG clinical outcomes related to metachronous gastric neoplasms (mGNs) in the residual stomach are currently lacking. Therefore, we aimed to evaluate the safety of PPG by focusing on mGNs.

METHODS

In this single-center, retrospective study, we reviewed the data for 362 patients who underwent PPG with a 3-cm antral cuff and 139 who underwent endoscopic submucosal dissection (ESD) for middle-third gastric cancer between January 2013 and December 2015. The histopathologic features of the antrum in the ESD group, which could not be determined in the PPG group, were analyzed to investigate the risk factors for mGNs. The estimated and actual incidence of mGNs in the antrum were compared in the PPG group.

RESULTS

The incidence of mGNs was 6.5% (9/139) in the ESD group. The presence of a synchronous adenoma (odds ratio [OR], 8.46; 95% confidence interval [CI], 1.55-46.34), carcinoma (OR, 15.71; 95% CI, 2.67-92.56) and moderate-to-severe intestinal metaplasia (OR, 9.77; 95% CI, 1.14-83.92) were associated with a higher risk of overall mGNs. However, when confined to the antrum, no significant association was observed between these factors and mGNs. In the ESD group, 2 of 9 mGNs (1.4%) were located at the 3-cm antral cuff. In the PPG group, both mGNs (0.6%) were located in the proximal remnant stomach.

CONCLUSION

Pylorus-preserving gastrectomy was a safe therapeutic option with regard to the occurrence of metachronous adenomas or carcinomas in our series. Despite the low mGN incidence in the 3-cm antral cuff after PPG, the presence of synchronous neoplasms or moderate-to-severe intestinal metaplasia was a risk factor for mGNs in the ESD group; thus, further studies on longer antral cuffs with long-term follow-up are needed.

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.

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

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.

The risk of lymph node metastasis in gastric cancer conforming to indications of endoscopic resection and pylorus-preserving gastrectomy: a single-center retrospective study

Background

Lymph node metastasis (LNM) status is an important prognostic factor that strongly influences the treatment decision of early gastric cancer (EGC). This study aimed to evaluate the pattern and clinical significance of LNM in EGC.

Methods

A total of 354 patients with carcinoma in situ (n = 42), EGC (n = 312) who underwent radical gastrectomy were enrolled. Their clinicopathological features, pathological reports, and prognostic data were collected and analyzed.

Results

The incidence of LNM in all patients was 18.36% (65/354). The rates of D1 and D2 station metastases were 12.10% (43/354) and 6.21% (22/354), respectively. The rates of LNM in absolute indication of endoscopic resection and expanded indication were 3.27% (2/61) and 28.55% (4/14), respectively. Skip LNM was observed in 3.67% (13/354) of patients. For those with middle-third tumor, the metastasis rate of the No. 5 lymph node was 3.05% (5/164). The independent risk factors for LNM were tumors measuring > 30 mm, poorly differentiated tumors, and lymphovascular invasion (all P < 0.05; area under the curve, 0.783). The 5-year disease-free survival rates of patients with and without LNM were 96.26 and 79.17%, respectively (P = 0.011). Tumors measuring > 20 mm and LNM were independent predictive factors for poor survival outcome in all patients.

Conclusions

Patients with EGC conforming to expanded indications have a relatively high risk of LNM and may not be suitable for endoscopic submucosal dissection. Pylorus-preserving gastrectomy for patients with middle-third EGC remains controversial due to the high metastasis rate of the No. 5 lymph node.

Short-term outcomes of a multicentre randomized clinical trial comparing laparoscopic pylorus-preserving gastrectomy with laparoscopic distal gastrectomy for gastric cancer (the KLASS-04 trial)

BACKGROUND

There remain concerns about the safety and functional benefit of laparoscopic pylorus-preserving gastrectomy (LPPG) compared with laparoscopic distal gastrectomy (LDG). This study evaluated short-term outcomes of a randomized clinical trial (RCT) comparing LPPG with LDG for gastric cancer.

METHODS

The Korean Laparoendoscopic Gastrointestinal Surgery Study (KLASS)-04 trial was an investigator-initiated, open-label, parallel-assigned, superiority, multicentre RCT in Korea. Patients with cT1N0M0 cancer located in the middle third of the stomach at least 5 cm from the pylorus were randomized to undergo LPPG or LDG. Participants, care givers and those assessing the outcomes were not blinded to group assignment. Outcomes were 30-day postoperative morbidity rate and death at 90 days.

RESULTS

Some 256 patients from nine institutions were randomized (LPPG 129 patients, LDG 127 patients) between July 2015 and July 2017 and outcomes for 253 patients were analysed. Postoperative complications within 30 days were seen in 19.3 and 15.5 per cent in the LPPG and LDG groups respectively (P = 0·419). Postoperative pyloric stenosis was observed in nine (7.2 per cent) and two (1·5 per cent) patients in the LPPG and LDG groups (P = 0·026) respectively. In multivariable analysis higher BMI was a risk factor for postoperative complications (odds ratio 1·17, 95 per cent c.i. 1·04 to 1·32; P = 0·011). Death at 90 days was zero in both groups.

CONCLUSION

Postoperative complications and mortality was comparable in patients undergoing LPPG and LDG. Registration number: NCT02595086 (http://www.clinicaltrials.gov).

Advances in the surgical management of gastric and gastroesophageal junction cancer

Since Theodore Billroth and Cesar Roux perfected the methods of post-gastrectomy reconstruction in the late 19^th century, surgical management of gastric and gastroesophageal cancer has made incremental progress. The majority of patients with localized disease are treated with perioperative combination chemotherapy or neoadjuvant chemoradiation. Staging laparoscopy before initiation of treatment or before surgical resection has improved staging accuracy and can drastically inform treatment decisions. The longstanding and contentious debate on the optimal extent of lymph node dissection for gastric cancer appears to have settled in favor of D2 dissection with the recently published 15-year follow-up of the Dutch randomized trial. Minimally invasive gastric and gastroesophageal resections are performed routinely in most centers affording faster recovery and equivalent oncologic outcomes. Pylorus-preserving distal (central) gastrectomy has emerged as a less invasive, function-preserving option for T1N0 middle-third gastric cancers, while randomized data on its oncologic adequacy are pending. Multi-visceral resections and cytoreductive surgery with hyperthermic intraperitoneal chemotherapy has been utilized selectively for patients with locally advanced tumors who have demonstrated disease control on preoperative chemotherapy. This review summarizes the current standard of surgical care for gastroesophageal junction and gastric cancer as well as highlights recent and upcoming advances to the field.

Radiologic intervention due to delayed gastric emptying after pylorus preserving gastrectomy for gastric cancer does not affect pyloric function

Purpose

The purpose of this study is to evaluate whether radiologic intervention in the pylorus decreases its function for delayed gastric emptying (DGE) patients after pylorus preserving gastrectomy (PPG) for gastric cancers and to determine the optimal interventional algorithm.

Methods

PPG patients who underwent intervention for DGE from January 2013 to December 2017 and a control group using propensity score matching were identified. Pyloric function was compared by subjective symptoms, postoperative upper gastrointestinal series at 3 months (short-term function), and esophagogastroduodenoscopy findings at 12 months (long-term function). Serum albumin levels and body weight change, 6 months and 12 months postoperatively, were compared to evaluate nutritional status. Interventional success rate, mean hospital stay, and recurrence of DGE were analyzed to determine the optimal intervention plan.

Results

Fifty-one out of 677 patients (7.53%) received intervention. There was no difference in pyloric function and nutritional status between the intervention and control groups. The interventional success rate for first-time balloon dilatation was 41.7% (20/48). If a second intervention was required and balloon dilatation was done, the success rate was 45.5% (5/11). However, if stent insertion was done, the success rate was 100% (17/17). Subsequent stent insertion after balloon dilatation resulted in a shorter mean hospital stay. Intervention including stent insertion had a lower recurrence of DGE than balloon only intervention (1.96% vs. 5.88%, P=0.041).

Conclusion

Radiologic intervention did not decrease long-term pyloric function. For treating DGE, if at first balloon dilatation fails, retrievable stent insertion can be considered as a second choice.

Proximal Anterior-Antrum Posterior (PAAP) Overlapping Anastomosis in Minimally Invasive Pylorus-Preserving Gastrectomy for Early Gastric Cancer Located in the High Body and Posterior Wall of the Stomach

Purpose

To evaluate the feasibility and safety of intracorporeal overlapping gastrogastrostomy between the proximal anterior wall and antrum posterior wall (PAAP; PAAP anastomosis) of the stomach in minimally invasive pylorus-preserving gastrectomy (PPG) for early gastric cancer (EGC).

Materials and Methods

From December 2016 to December 2019, 17 patients underwent minimally invasive PPG with PAAP anastomosis for EGC in the high body and posterior wall of the stomach. Intraoperative gastroscopy was performed with the rotation maneuver during proximal transection. A longer antral cuff (>4-5 cm) was created for PAAP than for conventional PPG (≤3 cm) at the point where a safe distal margin and good vascular perfusion were secured. Because the posterior wall of the proximal remnant stomach was insufficient for intracorporeal anastomosis, the anterior wall was used to create an overlapping anastomosis with the posterior wall of the remnant antrum. The surgical and oncological outcomes were analyzed, and the stomach volume was measured in patients who completed the 6-month follow-up. The results were compared to those after conventional PPG (n=11 each).

Results

PAAP anastomosis was successfully performed in 17 patients. The proximal and distal resection margins were 2.4±1.9 cm and 4.0±2.6 cm, respectively. No postoperative complications were observed during the 1-year follow-up esophagogastroduodenoscopy (n=10). The postoperative remnant stomach (n=11) was significantly larger with PAAP than with conventional PPG (225.6±118.3 vs. 99.1±63.2 mL; P=0.001). The stomach length from the anastomosis to the pylorus was 4.9±2.4 cm after PAAP.

Conclusions

PAAP anastomosis is a feasible alternative for intracorporeal anastomosis in minimally invasive PPG for highly posteriorly located EGC.

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.

Pylorus-preserving gastrectomy for early cancer involving the upper third: can we go higher?

BACKGROUND

Pylorus-preserving gastrectomy (PPG) is commonly performed for early gastric cancer (EGC) located in middle third of the stomach. We investigated the surgical, oncological, and functional outcomes of PPG involving the upper third of stomach.

METHODS

We included all patients of the period 2013-2016 who underwent PPG, distal subtotal gastrectomy (DSG), and total gastrectomy (TG) for EGC involving the upper third by carefully defining the localization. Surgical, oncological, and functional outcome analyses included postoperative morbidity, lymph-node metastasis, tumor recurrence, postoperative body weight, body mass index, hemoglobin, total protein, albumin, quantification of intraabdominal fat, and gallstone development.

RESULTS

Overall, 288 cases were analyzed: 145 PPG, 61 DSG, and 82 TG. In the study period, patients potentially underwent PPG for EGC involving the upper third, if enough proximal remnant stomach was found whilst achieving a sufficient proximal margin. PPG resulted in less operation time (p < 0.001), less blood loss (p = 0.002) and lower postoperative morbidity compared to TG. For lymph-node (LN) stations being resected in all groups, no difference was found in number of resected LN. Recurrence-free survival was similar for all groups. PPG showed advantages regarding postoperative body weight, hemoglobin, total protein, albumin in postoperative 6 and 12 month follow-up. Lowest decrease of abdominal fat area after 12 months was seen for PPG. Gallstone incidence was significantly lower after PPG compared to TG (p < 0.001).

CONCLUSIONS

For EGC involving the upper third, PPG can be another good option with lower postoperative morbidity, better functional outcomes, and same oncological safety.

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.

功能保留手术在早期胃癌治疗中的作用

随着人们健康意识的增加和胃镜等医疗诊断技术的不断进步, 早期胃癌的诊断率逐年上升. 早期胃癌的功能保留胃切除术是在根治原发病灶, 行标准淋巴结清扫前提下, 限制胃切除范围, 同时保留幽门及迷走神经功能, 以达到改善患者术后生活质量的目的, 其手术方式包括: 保留幽门的胃切除术, 近端胃切除术, 胃节段切除以及局部切除. 此外, 内镜下黏膜切除术和黏膜剥离也被认为属于功能保留胃切除术范畴. 对于大部分早期胃癌患者, 根治性手术具有良好的治疗效果, 其5年生存率在90%以上. 因此, 在达到手术根治目的的前提下, 保留部分胃的解剖和生理功能, 提高患者术后的生活质量, 对早期胃癌患者具有重要的意义.

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.

Surgical Considerations in the Management of Gastric Adenocarcinoma

Since Theodor Billroth and César Roux perfected the methods of postgastrectomy reconstruction in as early as the late nineteenth century, surgical management of gastric cancer has made incremental progress. The longstanding and contentious debate on the optimal extent of lymph node dissection for gastric cancer seems to have settled in favor of D2 dissection. Pylorus-preserving distal (central) gastrectomy has emerged as a less invasive, function-preserving option for T1N0 middle-third gastric cancers. Frozen section analysis of margins seems partially helpful in this direction. Last, the role of palliative gastrectomy in patients with metastatic seems less important than initially thought.

Pylorus-Preserving Gastrectomy for Gastric Cancer

Pylorus-preserving gastrectomy (PPG) is a function-preserving surgery for the treatment of early gastric cancer (EGC), aiming to decrease the complication rate and improve postoperative quality of life. According to the Japanese gastric cancer treatment guidelines, PPG can be performed for cT1N0M0 gastric cancer located in the middle-third of the stomach, at least 4.0 cm away from the pylorus. Although the length of the antral cuff gradually increased, from 1.5 cm during the initial use of the procedure to 3.0 cm currently, its optimal length still remains unclear. Standard procedures for the preservation of pyloric function, infra-pyloric vessels, and hepatic branch of the vagus nerve, make PPG technically more difficult and raise concerns about incomplete lymph node dissection. The short- and long-term oncological and survival outcomes of PPG were comparable to those for distal gastrectomy, but with several advantages such as a lower incidence of dumping syndrome, bile reflux, and gallstone formation, and improved nutritional status. Gastric stasis, a typical complication of PPG, can be effectively treated by balloon dilatation and stent insertion. Robot-assisted pylorus-preserving gastrectomy is feasible for EGC in the middle-third of the stomach in terms of the short-term clinical outcome. However, any benefits over laparoscopy-assisted PPG (LAPPG) from the patient's perspective have not yet been proven. An ongoing Korean multicenter randomized controlled trial (KLASS-04), which compares LAPPG and laparoscopy-assisted distal gastrectomy for EGC in the middle-third of the stomach, may provide more clear evidence about the advantages and oncologic safety of PPG.

Ongoing surgical clinical trials on minimally invasive surgery for gastric cancer: Korea

Since Korean Laparoscopic Gastrointestinal Surgery Study (KLASS) group was activated in 2003, several randomized controlled trials (RCTs) have finished or are ongoing in Korea to evaluate oncologic safety and feasibility of minimally invasive surgery (MIS) for gastric cancer by KLASS group as well as other expert surgeons. MIS in gastric cancer is regarded as one of standard treatment modality for early gastric cancer (EGC) and the indication is going expansion with the accumulation of evidence. This review covers current status of ongoing clinical trials on MIS for gastric cancer in Korea.

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.

Comparison of Surgical Outcomes of Robot-Assisted and Laparoscopy-Assisted Pylorus-Preserving Gastrectomy for Gastric Cancer: A Propensity Score Matching Analysis

BACKGROUND

The three-dimensional view and articulating devices in robot system might have a benefit performing the delicate procedure of pylorus-preserving gastrectomy. This study was conducted to evaluate the feasibility and safety of robot-assisted pylorus-preserving gastrectomy (RAPPG) and to compare the perioperative outcomes and oncologic safety between RAPPG and laparoscopy-assisted pylorus-preserving gastrectomy (LAPPG) for middle-third early gastric cancer.

METHODS

Between June 2008 and December 2013, we retrospectively collected data of 68 patients with RAPPG and propensity score matched 68 patients with LAPPG for the treatment of early gastric cancer at Seoul National University Hospital. The covariates for propensity score matching were: age, sex, American Society of Anesthesiologists score, body mass index, and operators. Clinicopathologic characteristics and surgical outcomes were compared between the two groups.

RESULTS

All RAPPG cases were performed successfully without open or laparoscopic conversion. Patient demographics and perioperative outcomes did not differ between the two groups except in operation time (258.3 vs. 193.9 min; P < 0.001). There was no significant difference in complication rates between the two groups (19.1 vs. 22.1 %; P = 0.671). The mean number of examined lymph nodes (33.4 vs. 36.5; P = 0.153), and the mean number of lymph nodes at each station was not different between the two groups.

CONCLUSIONS

RAPPG can be a safe treatment option for middle-third early gastric cancer in terms of surgical complications and oncologic outcomes. However, RAPPG has no benefit over LAPPG in this study.

Length of negative resection margin does not affect local recurrence and survival in the patients with gastric cancer

AIM: To investigate the influence of the resection margin on local recurrence and survival in gastric cancer patients.

METHODS: We reviewed the medical records of 1788 patients who had undergone gastrectomy for gastric cancer at the Seoul National University Bundang Hospital, South Korea, between May 2003 and July 2009. The patients were divided into early and advanced gastric cancer groups. In each group, we analyzed the relationship between clinicopathologic factors and survival outcomes, and compared the hazard rates of event occurrence between patients with resection margins above and below the cut-off value, using a Cox proportional hazard model.

RESULTS: The early and advanced gastric cancer groups included 1001 and 787 patients, respectively. The hazard rates of event occurrence did not significantly differ between the patients with resection margins above the cut-off value and those with resection margins below the cut-off value (P > 0.05, in all comparisons). Based on the multivariable analyses, the proximal and distal resection margins were not significantly associated with survival outcomes and local recurrence (P > 0.05, in all analyses).

CONCLUSION: The proximal or distal resection margins did not affect the prognosis of patients with gastric cancer if the margins were pathologically negative.

Laparoscopy-assisted pylorus-preserving gastrectomy is better than laparoscopy-assisted distal gastrectomy for middle-third early gastric cancer

OBJECTIVE

The purpose of this study is to compare the surgical, oncologic safety and the nutritional, functional benefit of laparoscopy-assisted pylorus-preserving gastrectomy (LAPPG) with laparoscopy-assisted distal gastrectomy (LADG) for middle-third early gastric cancers (EGC).

BACKGROUND

Of those patients with middle-third EGC, it is still difficult to determine which procedure is better between LADG and LAPPG despite alleged advantages of LAPPG.

METHODS

For middle-third EGC, a retrospective analysis was performed comparing those who underwent LADG and those who underwent LAPPG. To evaluate surgical and oncologic safety, clinicopathologic differences including the postoperative morbidity, the pattern of lymph node metastasis and recurrence were analyzed. Postoperative protein, albumin, quantification of abdominal fat area using abdomen computed tomography, and the incidence of postoperative gallstone were compared for the evaluation of functional advantages.

RESULTS

The overall postoperative morbidity rate was similar between LADG (n = 176) and LAPPG (n = 116). Delayed gastric emptying was less frequent in LADG than in LAPPG (1.7% vs 7.8%); however, the rates of all the other complications were significantly higher in LADG than in LAPPG (17.0% vs 7.8%). The number of examined lymph nodes and metastatic lymph nodes at each lymph node station was not significantly different and 3-year recurrence-free survival rates were also similar between LADG and LAPPG (98.8% vs 98.2%). Decreases in serum protein and albumin in postoperative 1 to 6 months and abdominal fat area in postoperative 1 year were significantly greater in LADG than in LAPPG. The 3-year cumulative incidence of gallstone was significantly higher in LADG than in LAPPG (6.5% vs 0.0%).

CONCLUSIONS

For middle-third EGC, LAPPG can be considered as a better treatment option than LADG in terms of nutritional advantage and lower incidence of gallstone.

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

BACKGROUND

Pylorus-preserving gastrectomy (PPG) is a function-preserving gastrectomy for early gastric cancers (EGCs) that are preoperatively assessed as pN0 tumors and located in the middle portion of the stomach. In PPG, dissection of the lymph nodes at stations 5 and 6 is frequently incomplete, and this may be worrisome in terms of oncologic safety.

METHODS

We examined lymph nodes collected from stations 5 and 6 from 196 patients who had undergone conventional distal gastrectomy (CDG) for EGC located in the middle portion of the stomach and from 24 patients who had undergone PPG.

RESULTS

The average number of lymph nodes collected at station 5 was significantly lower with PPG than with CDG (0.08 vs. 1.32, respectively; P = 0.008). However, such a difference was not noted for station 6 nodes. The rate of macrometastasis was very low in all station 5 nodes (1 of 220, 0.45%) and station 6 nodes (1 of 220, 0.45%). Immunohistochemical analysis of cytokeratin in 109 cases of the CDG group and 21 cases of the PPG group showed that micrometastasis of single isolated tumor cell type was observed in only one station 6 lymph node of a patient who was initially diagnosed with pN0 EGC. There were no cases of micrometastasis in station 5 nodes.

CONCLUSIONS

The possibility of micrometastasis to station 5 and/or 6 lymph nodes may be negligible for EGC located in the middle portion of the stomach, and PPG thus might be the oncologically safe procedure when considering micrometastasis in remaining nodes in vivo at stations 5 and 6.

An adequate perioperative management and strategy for gastric cancer after coronary artery bypass using the right gastroepiploic artery

PURPOSE

Interruption of the right gastroepiploic artery (RGEA) used for prior coronary artery bypass grafting (CABG) may cause life-threatening myocardial ischemia during gastrectomy. This study investigated the cases treated in this department and pooled data in the literature to identify an adequate perioperative RGEA management strategy.

METHODS

Eight patients underwent gastrectomy after CABG with the RGEA. This study examined conditions, management of the RGEA, No. 6 lymph node metastasis, and complications of these cases and those in the pooled data.

RESULTS

Percutaneous coronary intervention or a redo CABG was performed in advance in 7 and 1 patients, respectively. The RGEA was resected for dissection of No. 6 lymph nodes in 6 patients. Five patients had lymph node metastasis. Thirty-seven patients from 40 combined cases (92.5 %) underwent total or distal gastrectomy, but 17 patients (42.5 %) had RGEA resection. Resections of the RGEA and No. 6 lymph node metastasis were significantly higher in patients with perioperative coronary management than in those without such management.

CONCLUSION

Coronary and celiac angiography and coronary revascularization are prerequisites to prevent cardiac events during gastrectomy and dissection of No. 6 lymph nodes should be performed with resection of RGEA. Standard lymph node dissection should therefore be performed with a curative intent for all patients even those undergoing gastrectomy after CABG using RGEA.

Stage migration effect on survival in gastric cancer surgery with extended lymphadenectomy: the reappraisal of positive lymph node ratio as a proper N-staging

OBJECTIVE

The purpose of this study is to analyze the relationship between the number of examined lymph nodes (NexLN) and survival in gastric cancer and to determine whether the metastatic/examined lymph node ratio (LN ratio) system can compensate for the shortcomings of the UICC/AJCC staging.

METHODS

Prospective data of 8949 primary T1-T4a gastric cancer patients who underwent curative surgery were reviewed. The patients were stratified by T-stage and grouped according to NexLN; 1 to 14 exLN denoted the first group and every subsequent 10 LNs thereafter. Numbers of LN and 5-year survival rates were analyzed according to NexLN. "The NR-staging system" was generated using 0.2 and 0.5 as the cut-off values of LN ratio and then compared with UICC/AJCC stages.

RESULTS

The proportion of advanced N-stage increased with NexLN. Survival and the LN ratio were constant regardless of NexLN when combining all N0-N3b patients, however, T2/3 and T4a patients showed an increasing tendency toward survival in N1/2 and N3a as NexLN increased, mainly due to a stage migration effect. The LN ratio system showed better patterns of distribution of the LN stage and survival graph. The power of the differential staging of the LN ratio system was fortified with higher NexLN.

CONCLUSION

The relationship between NexLN and survival is probably affected by stage migration in a high-volume gastric cancer center. The LN ratio system could be a better option to compensate for this effect, and the value of the prognosis prediction in this system increases with a higher NexLN.

[Individualized surgery for gastric cancer]

Recently, tailored and multidisciplinary treatment of gastric cancer was emerging in the field of clinical oncology. Gastric cancer is the most frequently diagnosed cancer in Korea. Surgery is the only possible curative procedure, and extensive gastrectomy and D2 lymph node dissection has been accepted as standard treatment in all gastric cancer patients until recently. In early gastric cancer, many researchers established the indications of limited surgery including endoscopic mucosal resection based on various well-collected retrospective data. Limited surgery and minimally invasive surgery contribute to quality of life in gastric cancer patients. In advanced gastric cancer, eastern surgeons believe that D2 lymph node dissection is standard treatment if done by credential surgeons in specialized centers despite of different opinion of western surgeon. In addition, adjuvant chemotherapy after good local control by D2 dissection has gained survival benefit rather than D2 dissection alone in randomized trials. In conclusion, present confronted issue is to establish tailored treatments of individualized patients through extent of disease in gastric cancer patients.

Clinical significance of the pattern of lymph node metastasis depending on the location of gastric cancer

Purpose

When performing a laparoscopic assisted gastrectomy, a function-preserving gastrectomy is performed depending on the location of the primary gastric cancer. This study examined the incidence of lymph node metastasis by the lymph node station number by tumor location to determine the optimal extent of the lymph node dissection.

Materials and Methods

The subjects consisted of 1,510 patients diagnosed with gastric cancer who underwent a gastrectomy between 1996 and 2005. The patients were divided into three groups: upper, middle and lower third, depending on the location of the primary tumor. The lymph node metastasis patterns were analyzed in the total and early gastric cancer patients.

Results

In all patients, lymph node station numbers 1, 2, 3, 7, 10 and 11 metastases were dominant in the cancer originating in the upper third, whereas station numbers 4, 5, 6 and 8 were dominant in the lower third. In early gastric cancer patients, the station number of lymph nodes with a metastasis did not show a significant difference in stage pT1a disease. On the other hand, a metastasis in lymph node station number 6 was dominant in stage pT1b disease that originated in the lower third of the stomach.

Conclusions

When performing a laparoscopic-assisted gastrectomy for early gastric cancer, a limited lymphadenectomy is considered adequate during a function-preserving gastrectomy in mucosal (T1a) cancer. On the other hand, for submucosal (T1b) cancer, a number 6 node dissection should be performed when performing a pylorus preserving gastrectomy.

Validation of limited lymphadenectomy for lower-third gastric cancer based on depth of tumour invasion

BACKGROUND

This study aimed to determine the appropriate extent of lymph node (LN) dissection in gastric cancer by analysing LN metastasis patterns from prospectively collected topographical data on nodal status at Seoul National University Hospital, Korea.

METHODS

The metastasis rate for each LN station was analysed according to the depth of tumour invasion in patients with primary lower-third gastric cancer who underwent curative gastrectomy. The Maruyama Index of unresected disease (MI) was calculated using the WinEstimate(®) program with simulation of various extents of LN dissection.

RESULTS

LN metastasis in mucosal cancer was rare; 2·6 per cent of patients had a MI of more than 5 with simulation of D1 plus station 7 dissection, whereas 0·9 per cent had a MI above 5 with D1 plus stations 7 and 8a. In submucosal cancer, 3·3 per cent of tumours metastasized to level 2 LN stations outside the range of D1 plus stations 7, 8a and 9. The proportion of patients with a MI above 5 was 9·0 per cent with D1 plus stations 7, 8a and 9 dissection. The nodal metastasis rate was higher at level 1 and 2 for muscularis propria or deeper cancers.

CONCLUSION

D1 dissection plus stations 7 and 8a for mucosal cancer, and D2 dissection for cancers of the muscularis propria or deeper seems appropriate. For submucosal cancer, an expanded dissection to the D2 level should be considered to ensure complete removal of metastatic LNs.