A "Just Enough" Gross Proximal Margin Length Ensuring Pathologically Complete Resection in Distal Gastrectomy for Gastric Cancer

Diagnostic Performance of Near-Infrared Fluorescent Marking Clips in Laparoscopic Gastrectomy

INTRODUCTION

Accurate tumor localization and resection margin acquisition are essential in gastric cancer surgery. Preoperative placement of marking clips in laparoscopic gastrectomy as well as intraoperative gastroscopy can be used for gastric cancer surgery. However, these procedures are not available at all institutions. We conducted a prospective clinical trial to investigate the diagnostic performance of near-infrared fluorescent clips (ZEOCLIP FS) in laparoscopic gastrectomy.

MATERIALS AND METHODS

Patients with gastric cancer or neuroendocrine tumor in whom laparoscopic distal, pylorus-preserving, or proximal gastrectomy was planned were enrolled (n = 20) in this study. Fluorescent clips were placed proximal and/or distal to the tumor via gastroscopy on the day before surgery. During surgery, the clips were detected using a fluorescent laparoscope, and suturing was performed where fluorescence was detected. The clip locations were then confirmed via gastroscopy, and the stomach was transected. The primary endpoint was the detection rate of the marking clips using fluorescence, and the secondary endpoints were complications and distance between the clips and stitches.

RESULTS

Among the 20 patients enrolled, distal and pylorus-preserving gastrectomies were performed in 18 and 2 patients, respectively. All clips were detected in 15 patients, indicating a detection rate of 75.0% (90% confidence interval: 54.4%-89.6%). Furthermore, no complications related to the clips were observed. The median distance between the clips and stitches was 5 (range, 0-10) mm.

CONCLUSIONS

We report the feasibility and safety of preoperative placement and intraoperative detection of near-infrared fluorescent marking clips in laparoscopic gastrectomy.

Minimally Invasive Techniques for Gastrectomy

Gastric adenocarcinoma is an aggressive disease and a leading cause of cancer-related deaths worldwide. Surgery entails either a total or a subtotal gastrectomy. These complex operations carry elevated morbidity and mortality with an extended recovery time. As such, research has focused on minimizing these risks and enhancing postoperative care. Robotic surgery is a newer platform that helps overcome some of the limitations of laparoscopy through three-dimensional vision, better mobility, and improved surgeon dexterity. As such, many surgeons have embraced robotics and advocated for their implementation in cancer surgery. This review will discuss the technical considerations of performing a robotic gastrectomy.

Adequate gross resection margin length ensuring pathologically complete resection in gastrectomy for gastric cancer: A systematic review and meta-analysis

Aim

A positive resection margin (RM) is associated with poor survival after gastrectomy for gastric cancer (GC). However, the adequate RM length to avoid a positive RM remains controversial. We performed a systematic review to examine the RM length required to avoid a positive RM in gastrectomy for GC.

Methods

This systematic review involved all relevant articles identified in PubMed, the Cochrane Library, Web of Science, and ClinicalTrials.gov until August 2023. The incidence of a positive RM related to the RM length and the possible incidence of a positive RM estimated from the discrepancy between the gross and pathological RM length were evaluated. The Newcastle-Ottawa Scale was used to quantify study quality.

Results

Thirteen studies involving 8983 patients were analyzed. Investigation of the incidence of a positive RM in relation to the RM length showed that a proximal RM length of 6 cm guaranteed a negative RM in gastrectomy. Analyses of the possible incidence of a positive RM revealed that a negative RM would be guaranteed if the proximal RM length was 6 cm in distal gastrectomy, if the esophageal resection length was 2 cm in total gastrectomy for GC without esophageal invasion and 2.5 cm in total or proximal gastrectomy for GC with esophageal invasion or esophagogastric junction cancer, and if the distal RM length was 4 cm in proximal gastrectomy for early GC.

Conclusions

The adequate RM lengths to ensure a pathologically negative RM in each type of gastrectomy for GC were herein suggested.

Oncological impact of unexpected horizontal tumor spread in gastric cancer that requires total gastrectomy

BACKGROUND

Gastric cancer often exhibits discrepancies between the gross and pathological tumor boundaries, and the degree of discrepancy may be a tumor characteristic. However, whether these discrepancies influence oncological outcomes remains unclear.

METHODS

The data of patients who underwent total gastrectomy for gastric cancer from 2005 to 2018 were collected. A new parameter, ΔPM, which corresponds to the length of the discrepancy between the gross and pathological proximal boundaries, was calculated and the patients were divided into two groups: patients with long ΔPM and those with short ΔPM. Oncological outcomes were compared between the two groups.

RESULTS

A length of 8 mm was determined as the cutoff value for long or short ΔPM. Tumor size, growth pattern, pathological type, depth, and esophageal invasion were associated with ΔPM > 8 mm. Overall survival of the ΔPM > 8 mm group was significantly worse than that of the ΔPM ≤ 8 mm group (5-year overall survival: 58% vs 78%; p < 0.0001). Multivariate analysis revealed that ΔPM > 8 mm was an independent risk factor for poor survival and peritoneal metastasis. The likelihood ratio test revealed a significant interaction between pT status and ΔPM (p = 0.0007). Circumferential involvement and gross esophageal invasion were poorer survival factors in the ΔPM > 8 mm group.

CONCLUSIONS

ΔPM > 8 mm is related to several clinicopathological characteristics and is an independent risk factor for poorer survival and peritoneal metastasis but not local recurrence. ΔPM > 8 mm combined with circumferential involvement or esophageal invasion is associated with relatively poor survival outcomes.

Required esophageal resection length beyond the tumor boundary to ensure a negative proximal margin for gastric cancer with gross esophageal invasion or esophagogastric junction cancer

BACKGROUND

To obtain a pathologically negative proximal margin (PM) for gastric cancer with gross esophageal invasion (EI) or esophagogastric junction (EGJ) cancer, we should transect the esophagus beyond the proximal boundary of gross EI with a safety margin because of a discrepancy between the gross and pathological boundaries of cancer. However, recommendations regarding the esophageal resection length for these cancers have not been established.

METHODS

Patients who underwent proximal or total gastrectomy for gastric cancer with gross EI or EGJ cancer were enrolled. A parameter ΔPM, which corresponded to the length of a discrepancy between the gross and pathological proximal boundary of the tumor, was evaluated. The maximum ΔPM, which corresponded to the minimum length ensuring a pathologically negative PM, was first determined in all patients. Then subgroup analyses according to factors associated with ΔPM ≥ 10 mm were performed to identify alternative maximum ΔPMs.

RESULTS

A total of 289 patients with gastric cancer with gross EI or EGJ cancer were eligible and analyzed in this study. The maximum ΔPM was 25 mm. Clinical tumor (cTumor) size and growth and pathological types were independently associated with ΔPM ≥ 10 mm. In subgroup analyses, the maximum ΔPM was 15 mm for cTumor size ≤ 40 mm and superficial growth type. Furthermore, the maximum ΔPM was 20 mm in the expansive growth type.

CONCLUSIONS

Required esophageal resection lengths to ensure a pathologically negative PM for gastric cancer with gross EI or EGJ cancer are proposed.

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.

Minimum Esophageal Resection Length to Ensure Negative Proximal Margin in Total Gastrectomy for Gastric Cancer: A Retrospective Study

Objective

To identify the minimum length of esophageal resection to ensure a pathologically negative proximal margin (PM) in total gastrectomy for gastric cancer.

Background

In total gastrectomy, a certain esophageal length is resected to obtain a pathologically negative PM because of the possibility of unexpected pathological esophageal invasion. However, a recommendation regarding the esophageal transection site in total gastrectomy has not been established.

Methods

The data of patients who underwent total gastrectomy for gastric cancer from 2005 to 2018 were collected. We evaluated the length of unexpected pathological esophageal invasion (esophageal ΔPM) in each type of disease and each location of the gross proximal tumor boundary (PB) using the length between the PB and the esophagogastric junction (PB-EGJ length).

Results

Of the 1005 patients eligible for this study, 277, 196, and 532 had cT1, cT2-4 expansive (Exp), and cT2-4 infiltrative (Inf) growth patterns, respectively. In cT1 and Exp, no unexpected pathological esophageal invasion occurred when the PB-EGJ length was >1 cm, whereas pathological esophageal invasion occurred in 20.0% of cT1 and 32.7% of Exp when the PB-EGJ length was ≤1 cm. The esophageal ΔPM was <1 cm. In Inf, no unexpected pathological esophageal invasion occurred when the PB-EGJ length was >3 cm, whereas pathological esophageal invasion occurred in 17.4% of patients when the PB-EGJ length was ≤3 cm. The esophageal ΔPM was <2 cm.

Conclusions

New recommendations regarding the esophageal resection length required to ensure a pathologically negative PM in total gastrectomy are herein proposed.

Risk factors and oncological impact of positive resection margins in gastrectomy for cancer: are they salvaged by an additional resection?

BACKGROUND

The situation of positive resection margins (PRMs) varies notably between Western and Asian countries. In the West, PRMs are associated with advanced disease and R1, whereas in Asia, PRMs are also considered in early disease because stomach preservation was recently prioritized. Furthermore, PRMs are usually resected to obtain R0. However, the oncological impact of PRMs and additional resection remains unclear. The aim of this study is to evaluate the oncological impact of PRMs in laparoscopic gastrectomy (LG) for clinical stage (cStage) I gastric cancer.

METHODS

A total of 2121 patients who underwent LG for cStage I gastric cancer between 2007 and 2015 were enrolled. Survival outcomes were compared between patients with PRMs (group P) and those without (group N). Furthermore, prognostic factors were analyzed using multivariate analysis.

RESULTS

Twenty-seven patients (1.3%) had PRMs. Patients in group P had upper and more advanced disease, and the 5-year relapse-free survival (RFS) rate was worse in group P compared with group N (76.3% vs. 95.1%, P = 0.003). The 5-year RFS of patients with pT2 or deeper (pT2-4) disease in group P was significantly worse than that of patients in group N (66.7% vs. 89.5%, P = 0.030) although that of patients with pT1 was not. Likelihood ratio tests showed that there was a significant interaction between pT status and PRM (P = 0.005).

CONCLUSION

PRM in cStage I gastric cancer is associated with advanced upper disease. It remains an independent prognostic factor in pT2-4 disease even after an additional resection to obtain R0.

Short- and long-term oncological outcomes of totally laparoscopic gastrectomy versus laparoscopy-assisted gastrectomy for clinical stage I gastric cancer

BACKGROUND

Totally laparoscopic gastrectomy (TLG), which involves a complete intracorporeal gastric transection and the creation of an anastomosis, has been gradually adopted. However, a potential limitation of intracorporeal transection is the lack of tactile feedback, and whether this limitation influences oncological outcomes is unclear. The aim of this study is to evaluate the short- and long-term oncological safety of TLG using endoscopy-guided intracorporeal gastric transection for clinical stage (cStage) I gastric cancer.

METHODS

A total of 1875 consecutive patients who underwent laparoscopic gastrectomy for cStage I gastric cancer between January 2007 and March 2015 were enrolled in this study. Marking clips were preoperatively placed and a transection line was determined by perceiving it tactually in laparoscopy-assisted gastrectomy (LAG) or endoscopically in TLG. After propensity score matching, 1366 patients (683 each for LAG and TLG groups) were selected to primarily test the non-inferiority of TLG to that of LAG for relapse-free survival (RFS).

RESULTS

In the propensity-matched population, the 5-year RFS rates of the LAG and TLG groups were 94.3% (95% confidence interval (CI) 92.2-95.8%), and 95.6% (95% CI 93.8-96.9%), respectively. The hazard ratio (TLG/LAG) was 0.77 (95% CI 0.48-1.24, P for non-inferiority < 0.01). There were no significant differences in the recurrence profiles. The incidence of the remnant of marking clips or tumor tissue did not differ (LAG: 1.0% vs. TLG: 1.9%, P = 0.177).

CONCLUSIONS

TLG using preoperative markings and intraoperative endoscopic guidance provides cStage I gastric cancer patients with comparable oncological outcomes to the conventional method.