Advantages of endoscopic submucosal dissection with needle-knife over endoscopic mucosal resection for small rectal carcinoid tumors: a retrospective study

Background

Endoscopic submucosal dissection (ESD) is a new, widely accepted method for the treatment of early gastric cancer and was developed to increase the en bloc resection rate. This study aimed to evaluate the efficacy and safety of ESD compared with conventional endoscopic mucosal resection (EMR) for small rectal carcinoid tumors.

Methods

A retrospective study was carried out that included 43 patients with small rectal carcinoid tumors (<10 mm). The cohort comprised two groups: Group A (N = 23) underwent conventional EMR from January 2004 to August 2005, while group B (N = 20) underwent ESD with needle-knife from September 2005 to December 2006. The rate of curative en bloc resection, the procedure time, and the incidence of complications were evaluated.

Results

The en bloc resection rate and the rate of completeness of resection of group B were higher than those of group A (100 vs. 87%, 100 vs. 52.5%, respectively). The average operation time required for resection was significantly longer in group B (28.4 ± 17.2 min) compared with group A (12.3 ± 15.4 min) (p < 0.05). None of the patients had immediate or delayed bleeding during the procedure. Perforation occurred in one case of group B and the patient recovered after several days of conservative treatment. Three patients had local recurrence after EMR, while no patient experienced recurrence after ESD.

Conclusion

ESD, compared with conventional EMR, increased en bloc and histologically complete resection rates and may reduce local recurrence rate for small rectal carcinoid tumors. Increased operation time and complication risks with ESD remain problematic. Further technique and investigation are required to confirm the safety and to assess the long-term prognosis of ESD.     

Clinical outcomes of argon plasma coagulation for the treatment of gastric neoplasm

Background

There are insufficient reports on the outcomes and local recurrence rates for gastric neoplasms treated using argon plasma coagulation (APC). The purpose of this study was to analyze the clinical outcomes in early gastric cancer or gastric adenoma patients following APC treatment.

Methods

Seventy-one patients were enrolled and all underwent APC at the Asan Medical Center between July 2007 and August 2011. Clinical and oncological outcomes were analyzed.

Results

The median follow-up period was 20 months (interquartile range 13–29 months). Among the 71 patients we evaluated, nonlifting after submucosal saline injection was found in 35 patients and 15 patients (21.2 %) experienced local recurrence with a median period of 10 months (IQR 5–13 months). The rate of local recurrence was higher in the nonlifting group and the 40-W group than in the lifting group and the 60- or 80-W groups (31.4 vs. 11.1 %, p = 0.045 and 31.7 vs. 6.7 %, p = 0.017, respectively). Multivariate analysis showed that the power setting with the 40-W and nonlifting groups after submucosal injection was associated with local recurrence.

Conclusions

APC therapy after submucosal saline injection using high power (60 or 80 W) appears to be an effective alternative in the management of gastric neoplasm.     

Clinical significance of intraperitoneal air on computed tomography scan after endoscopic submucosal dissection in patients with gastric neoplasms

Background

Perforations are major complications of endoscopic gastric resection, including endoscopic submucosal dissection (ESD), and are generally detected on chest radiography following ESD. We hypothesized that a small amount of free air, defined as “intraperitoneal air,” would not be noted on chest radiography. In this study we aimed to determine how often intraperitoneal air is seen on a computed tomography (CT) scan after ESD and to evaluate the association between clinical factors and intraperitoneal air.

Methods

A total of 147 patients who underwent ESD for gastric neoplasms were analyzed between September 2009 and September 2010. Patients underwent both chest radiography and noncontrast CT scans. Intraperitoneal air on the CT scan was stratified by the amount of gas as follows: grade I, free air localized along the outside of the gastric wall; grade II, free air in the lesser sac; and grade III, free air in front of the liver.

Results

Intraperitoneal air was detected in 56 patients (38.1 %) by an abdominal CT scan, whereas free air was noted in 2 patients (1.4 %) by chest radiography. Most patients with intraperitoneal air (96.4 %, 54/56) were grade I or II and 3.6 % (2/56) were grade III. Abdominal pain was more frequent in the intraperitoneal air group (32.1 %, 18/56) than in the no intraperitoneal air group (17.6 %, 16/91; P = 0.042). Tumor location at the lesser curvature was more frequent in the intraperitoneal air group (66.1 %, 37/56) than in the no intraperitoneal air group (38.5 %, 35/91; P < 0.001). Fever, use of antibiotics, duration of hospital stay, C-reactive protein level, white blood cell count, complete resection, and local recurrence did not differ between the two groups. All patients who had intraperitoneal air recovered completely with medical treatment.

Conclusion

Intraperitoneal air after gastric ESD occurred unexpectedly frequently. However, a small amount of intraperitoneal air on a CT scan does not cause clinically significant complications.     

Long-term outcomes of endoscopic submucosal dissection for early gastric cancer: a single-center experience

Background

In Korea, endoscopic submucosal dissection (ESD) has been widely accepted for the treatment of early gastric cancers (EGCs). However, the understanding of the long-term clinical outcome of ESD for EGC remains insufficient. Therefore, the aim of the present study was to assess the long-term clinical outcome and efficacy of ESD for the treatment of EGCs, including the clinical application of the expanded criteria for ESD.

Methods

From January 2006 to December 2010, a total of 515 patients with 522 EGCs were treated by ESD in our hospital; study enrollment was based on the expanded criteria. Comparisons of resectability (en bloc or piecemeal resection), curability (curative or non-curative), and complications (bleeding and perforation) between the standard and expanded groups were assessed. Thereafter, 336 patients with 342 EGCs were finally included in a long-term analysis of local tumor recurrence, development of synchronous and metachronous cancers, and overall and disease-specific survival rates.

Results

En bloc and curative resection rates of 96.7 % and 88.3 %, respectively, were achieved. The curative resection rate was significantly lower in the expanded group than in the standard group (82.1 % vs. 91.5 %, p = 0.001). During a median follow-up of 24 months, the local tumor recurrence rate was also higher in the expanded group than in the standard group (7.0 % vs. 1.8 %, p = 0.025). Local recurrence was more frequent in lesions with non-curative resection than in those with curative resection (20.0 % vs. 1.3 %, p < 0.001). The 5-year overall and disease-specific survival rates were 88 % and 100 %, respectively; the difference between the standard and expanded groups was not significant (p = 0.834).

Conclusions

ESD appears to be a feasible and effective method for treating EGCs, based on the standard and expanded criteria. Close follow-up surveillance, after ESD, should be standard for all patients.     

Endoscopic submucosal dissection versus transanal endoscopic microsurgery for the treatment of early rectal cancer

Background

Endoscopic submucosal dissection (ESD) and transanal endoscopic microsurgery (TEM) are minimally invasive procedures that can be used to treat early rectal cancer.

Objective

The aim of this study was to compare clinical efficacy between ESD and TEM for the treatment of early rectal cancer.

Methods

Between July 2008 and August 2011, 24 patients with early rectal cancers were treated by ESD (11) or TEM (13) at the Cancer Institute of São Paulo University Medical School (São Paulo, Brazil). Data were analyzed retrospectively according to database and pathological reports, with respect to en bloc resection rate, local recurrence, complications, histological diagnosis, procedure time and length of hospital stay.

Results

En bloc resection rates with free margins were achieved in 81.8 % of patients in the ESD group and 84.6 % of patients in the TEM group (p = 0.40). Mean tumor size was 64.6 ± 57.9 mm in the ESD group and 43.9 ± 30.7 mm in the TEM group (p = 0.13). Two patients in the TEM group and one patient in the ESD group had a local recurrence. The mean procedure time was 133 ± 94.8 min in the ESD group and 150 ± 66.3 min in the TEM group (p = 0.69). Mean hospital stay was 3.8 ± 3.3 days in the ESD group and 4.08 ± 1.7 days in the TEM group (p = 0.81).

Limitations

This was a non-randomized clinical trial with a small sample size and selection bias in treatment options.

Conclusion

ESD and TEM are both safe and effective for the treatment of early rectal cancer.     

Comparison of the efficacy of 4- and 8-week lansoprazole treatment for ESD-induced gastric ulcers: a randomized, prospective, controlled study

Background

Although endoscopic submucosal dissection (ESD) is widely used to treat gastric neoplasms, there is no consensus for the optimal treatment for ESD-induced ulcers. We compared efficacy between 4 and 8 weeks of lansoprazole treatment for iatrogenic gastric ulcers that developed after ESD.

Methods

Eighty-four patients who were diagnosed with gastric adenoma or early gastric cancer were enrolled and randomly assigned to treatment with lansoprazole (30 mg/day) for 4 or 8 weeks. Eight weeks after ESD, we conducted follow-up endoscopy to compare ulcer stage and ulcer reduction ratio (dividing the ulcer dimension at 8 weeks by the initial ulcer dimension) between the two groups.

Results

From the 84 patients, 69 patients were included in the final analysis, with 34 in the 4-week group and 35 in the 8-week group. Eight weeks after ESD, there were no significant difference observed between the two groups in terms of the ulcer stage (68 % in the scar stage in the 4-week group vs. 69 % in the 8-week group, P = 0.93) or the ulcer reduction ratio (0.0081 ± 0.015 in the 4-week group vs. 0.0037 ± 0.008 in the 8-week group, P = 0.15). Also, in the subgroup analysis among the patients with large ulcers (>30 mm), those parameters were not different.

Conclusions

For ESD-induced gastric ulcers, treatment with lansoprazole for 4 weeks was as effective as treatment for 8 weeks. Considering cost-effectiveness, proton pump inhibitor therapy for 4 weeks may be sufficient for ESD-induced gastric ulcers.     

Clinical outcome of endoscopic submucosal dissection versus endoscopic mucosal resection of large colorectal tumors as determined by curative resection

Background and Aims

Endoscopic submucosal dissection (ESD) has recently been applied to the treatment of superficial colorectal cancer. Clinical outcomes compared with conventional endoscopic mucosal resection (EMR) have not been determined so our aim was to compare the effectiveness of ESD with conventional EMR for colorectal tumors ≥20 mm.

Methods

This was a retrospective case-controlled study performed at the National Cancer Center Hospital in Tokyo, Japan involving 373 colorectal tumors ≥20 mm determined histologically to be curative resections. Data acquisition was from a prospectively completed database. We evaluated histology, tumor size, procedure time, en bloc resection rate, recurrence rate, and associated complications for both the ESD and EMR groups.

Results

A total of 145 colorectal tumors were treated by ESD and another 228 were treated by EMR. ESD was associated with a longer procedure time (108 ± 71 min/29 ± 25 min; p < 0.0001), higher en bloc resection rate (84%/33%; p < 0.0001) and larger resected specimens (37 ± 14 mm/28 ± 8 mm; p = 0.0006), but involved a similar percentage of cancers (69%/66%; p = NS). There were three (2%) recurrences in the ESD group and 33 (14%) in the EMR group requiring additional EMR (p < 0.0001). The perforation rate was 6.2% (9) in the ESD group and 1.3% (3) in the EMR group (p = NS) with delayed bleeding occurring in 1.4% (2) and 3.1% (7) of the procedures (p = NS), respectively, as all complications were effectively treated endoscopically.

Conclusions

Despite its longer procedure time and higher perforation rate, ESD resulted in higher en bloc resection and curative rates compared with EMR and all ESD perforations were successfully managed by conservative endoscopic treatment.     

Predictive risk factors of perforation in gastric endoscopic submucosal dissection for early gastric cancer: a large, multicenter study

Background

Although endoscopic submucosal dissection (ESD) is standard therapy for early gastric cancer, the complication rate is unsatisfactory, with perforation as the major complication during ESD. There have been several reports regarding the complications of ESD for gastric tumor especially perforation; however, little is known about the predictors for complications in patients undergoing ESD. The purpose of this retrospective study was to determine the risk factors for perforation in patients with early gastric cancer during ESD.

Methods

Between February 2003 and May 2010, we performed ESD for 1,289 lesions in 1,246 patients at six tertiary academic hospitals in Daegu, Kyungpook, Korea. Patient-related variables (age, sex, and underlying disease), endoscopic-related variables (indication of ESD, lesion size, location, type, and mucosal ulceration), procedure-related variables (operation time, complete resection, and invasion of submucosa/vessel/lymph node), and the pathologic diagnosis were evaluated as potential risk factors.

Results

The mean age of the patients was 64 years. The mean size of the endoscopic lesion was 19.4 mm. The overall en bloc resection rate was 93.3 %. Perforation (microperforation and macroperforation) was seen in 35 lesions. The location of the lesion (long axis: body/short axis: greater and lesser curvature) and piecemeal resection were associated with perforation (p = 0.01/0.047 and p = 0.049). Upon multivariate analysis, the location (body vs. antrum) of the lesion (odds ratio (OR) 2.636; 95 % confidence interval (CI) 1.319–5.267; p = 0.006) and piecemeal resection (OR 2.651; 95 % CI 1.056–6.656; p = 0.038) were significant predictive factors for perforation.

Conclusions

The result of this study demonstrated that the location of the lesion (body) and piecemeal resection were related to perforation during ESD.     

Long-term outcomes of endoscopic submucosal dissection for early gastric cancer: a comparison study to surgery using propensity score-matched analysis

Background

Endoscopic submucosal dissection (ESD) has been accepted as a standard treatment in early gastric cancer (EGC) patients with negligible risk of lymph node metastasis. However, there are limited data regarding the long-term outcomes of ESD in comparison with surgery. This study aimed to compare the overall, recurrence-free, and metachronous cancer-free survival rates after ESD and surgery.

Methods

From May 2003 to December 2007, 391 patients with 413 EGCs and 258 patients with 276 EGCs were treated by ESD and surgery, respectively. According to inclusion criteria, 288 patients in the ESD group and 173 patients in the surgery group were eligible for this study. Using propensity score matching, 88 patients were analyzed per group.

Results

The overall survival rates were 92.0 % in the ESD group and 90.2 % in the surgery group. Local recurrence was observed in five patients (1.7 %) in the ESD group and distant recurrence in one patient (0.6 %) in the surgery group. Metachronous gastric cancers were detected in 14 patients (4.9 %) in the ESD group, whereas no patient in the surgery group. Kaplan–Meier curves exhibited no significant differences in overall or recurrence-free survival between the two groups. However, metachronous cancer-free survival of the ESD group was significantly lower than that of the surgery group (p = 0.002). In the ESD group, the late complication rate was significantly lower (0 vs. 6.8 %, p = 0.029), and the duration of hospital stay was shorter (7.3 vs. 14.2 days, p < 0.001), compared with the surgery group.

Conclusions

The overall survival was similar between the ESD and surgery groups. Compared with surgery, the benefits of ESD included fewer late complications and shorter hospital stay duration.

     

Clinical validity of the expanded criteria for endoscopic resection of undifferentiated-type early gastric cancer based on long-term outcomes

Background

According to the Japanese Gastric Cancer Treatment Guidelines, the expanded criteria for endoscopic resection (ER) of undifferentiated-type early gastric cancer (UEGC) is ulcer-negative, intramucosal cancer 20 mm or less in diameter without lymphovascular invasion. The aim of this study was to confirm validity of the expanded criteria for curative ER of UEGC.

Methods

Subjects were 125 patients from whom 125 UEGCs were resected endoscopically between April 1990 and March 2011. Endoscopic mucosal resection (EMR) (28 lesions, 28 patients) or endoscopic submucosal dissection (ESD) (97 lesions, 97 patients) was performed. We determined the complete resection rate, post-ER bleeding rate, perforation rate, and outcome in both groups, and analyzed the survival outcomes of 84 patients who were followed for more than 5 years (mean, 101.9 months) according to the indication for ER [expanded criteria for curative (n = 52) vs. criteria for noncurative (n = 32)].

Results

Complete resection rates for EMR and ESD were 54 % (15 of 28) and 89 % (86 of 97), respectively, with that for ESD being significantly higher (p < 0.01). Outcomes after ER were as follows: among 52 cases of UEGC meeting the expanded criteria, additional surgical resection was performed in 11 cases of incomplete resection. No local recurrence or lymph node metastasis was observed. Forty-eight patients who were simply surveyed clinically (93.6 ± 38.4 months) after ER survived without recurrence; the remaining 7 patients died of other causes. Among the 32 cases of UEGC meeting the criteria for noncurative resection, additional surgical resection was performed in 13 cases. Among the 19 follow-up cases (108.3 ± 38.7 months), death due to metastasis of the primary disease occurred in 3 cases, death from other causes occurred in 5 cases, and local residual submucosal recurrence occurred in 1 case.

Conclusions

ESD is a useful technique for complete resection as a total excisional biopsy compared with EMR and radical cure of UEGCs meeting the expanded criteria.     

Outcomes and predictive factors of “not self-completion” in gastric endoscopic submucosal dissection for novice operators

Background

Endoscopic submucosal dissection (ESD) has become the standard endoscopic treatment for gastric neoplasms because of its safety and high rate of curability; however, it is not easy for novice operators to learn the technique of ESD. In this study, predictive factors of gastric neoplasms in which novices could not finish ESD by self-completion were evaluated.

Methods

Eighty consecutive ESD procedures performed by four novice operators were retrospectively analyzed. Standard ESD procedures were performed using an insulation-tipped (IT) knife under supervision. Self-completion rates, procedure time, and complete resection rates were evaluated, and predictive factors for “not self-completion” were assessed.

Results

The overall self-completion rate and en bloc plus R0 resection rate were 87.5% (70/80) and 95.7 % (67/70), respectively. In “not self-completion” cases (n = 10), the procedure time was longer and resected specimens were larger than those in self-completion cases (83.7 ± 47.3 min vs. 189.5 ± 106.8 min, p < 0.05; 641.2 ± 487.8 vs. 1,116 ± 480.4 mm², p < 0.01). Predictive factors of “not self-completion” were tumor location in the middle or upper third of the stomach or in the greater curvature and size of resected specimens larger than 900 mm². The self-completion rate of ESD was decreased in cases with more than two predictive factors.

Conclusions

For novice operators, tumor location and resected areas are predictive factors for failure to finish gastric ESD by self-completion. Selection of cancer lesions could be a key factor for effectiveness of ESD training.     

Endoscopic submucosal dissection as a treatment for gastric subepithelial tumors that originate from the muscularis propria layer: a preliminary analysis of appropriate indications

Background

Endoscopic submucosal dissection (ESD) is a well-established method for the treatment of gastrointestinal epithelial tumors. However, the treatment of gastric subepithelial tumors (SETs) that originate from the muscularis propria layer still depends primarily on surgical techniques. We evaluated the appropriate indications for ESD in the treatment of SETs that originate from the muscularis propria layer.

Methods

Thirty-five patients with gastric SETs that originate from the muscularis propria layer who underwent ESD were enrolled, and the charts were retrospectively reviewed to investigate the parameters predictive complete resection and complications.

Results

The mean age of the patients was 54.15 ± 9.3 years, and the male/female ratio was 2:3. Twenty-eight of the 35 SETs (85.7 %) were movable, and 15 (45.7 %) had a positive rolling sign. The most frequent location of the SETs was high body (n = 14). The most common pathological diagnoses were leiomyoma (60 %) and gastrointestinal stromal tumor (28.6 %). The complete resection rate was 74.3 %. A positive rolling sign (p = 0.022) and small tumor size (≤20 mm; p = 0.038) were significantly associated with complete resection. Two patients (6.1 %) developed perforations that required surgical treatment; their SMTs were neurogenic tumors with fixed lesion. Tumor mobility was significantly associated with perforation (p = 0.017).

Conclusions

The ESD method appears to be relatively safe for use in the complete resection of SETs that originate from the muscularis propria layer. Small tumor size (≤20 mm) and a positive rolling sign are appropriate indications for ESD.     

Sedation methods can determine performance of endoscopic submucosal dissection in patients with gastric neoplasia

Background

Although proper sedation is mandatory for endoscopic procedures such as endoscopic submucosal dissection (ESD), there is no research investigating the effects of sedation on ESD performance and complications. We aimed to evaluate the relationship among sedation methods, clinical outcomes, and complications after ESD for gastric neoplasia.

Methods

We retrospectively reviewed clinical data of 1,367 patients with 1,485 lesions who had undergone ESD for gastric adenoma or early gastric cancer at our tertiary teaching hospital in Seoul, Korea, between January 2008 and May 2011. Of these, 1,035 lesions in 958 patients were included in the intermittent midazolam/propofol injection by endoscopists (IMIE) group, and 450 lesions in 409 patients were included in the continuous propofol infusion with opioid administration by anesthesiologists (CPIA) group.

Results

En bloc resection and complete resection rates were higher in the CPIA group than in the IMIE group (CPIA vs. IMIE; en bloc resection, 99.8 and 95.0 %, P < 0.001; complete resection, 94.2 and 88.3 %, P < 0.001). Duration of procedure was shorter in the CPIA group than in the IMIE group (CPIA vs. IMIE; 48.2 ± 32.5 and 57.6 ± 41.3 min, P < 0.001). In multivariate analysis, sedation method was an independent factor associated with en bloc resection and complete resection. Additionally, sedation with CPIA was not a risk factor for bleeding (P = 0.403) or perforation (P = 0.474); however, aspiration pneumonia developed more frequently in patients sedated with CPIA (CPIA vs. IMIE, 4.4 and 1.5 %, P = 0.002).

Conclusions

Sedation with CPIA can improve ESD performance.     

Is transnasal endoscope-assisted endoscopic submucosal dissection for gastric neoplasm useful in training beginners? A prospective randomized trial

Background

The main problem in performing endoscopic submucosal dissection (ESD) of gastric neoplasms is that it is technically difficult, especially for beginners.

Methods

A total of 51 patients were randomly assigned to undergo transnasal endoscope-assisted or routine ESD performed by two endoscopists inexperienced in ESD while supervised by one expert.

Results

Total procedure time (p = 0.330), complete resection rate (p = 0.977), and complication rate (p = 0.157) were similar for the patients who underwent transnasal endoscope-assisted and routine ESD, but bleeding control time was significantly longer in the transnasal endoscope-assisted ESD group (p = 0.002). Three and six patients in the transnasal endoscope-assisted and routine ESD groups, respectively, were “dropped out” during the procedures (p = 0.291). The endoscopists tended to regard the traction with the transnasal endoscope as more useful for large tumors (p = 0.062). Bleeding control in patients who underwent the transnasal endoscope-assisted ESD was significantly longer for patients with tumors located in the anterior wall, posterior wall, and lesser curvature of the stomach (p = 0.001).

Conclusion

Transnasal endoscope-assisted ESD does not result in improved outcomes when performed by beginners, except for some large tumors. The traction method used by beginners was not superior to proper supervision and advice by an expert during ESD and allowing the expert to perform the procedure when the risk of complications is high or the procedure is delayed.     

Efficacy of endoscopic mucosal resection using a dual-channel endoscope compared with endoscopic submucosal dissection in the treatment of rectal neuroendocrine tumors

Background

Conventional endoscopic mucosal resection (EMR) for removing rectal neuroendocrine tumors (NETs) has a high risk of incomplete removal because of submucosal tumor involvement. EMR using a dual-channel endoscope (EMR-D) may be a safe and effective method for resection of polyps in the gastrointestinal tract. The efficacy of EMR-D in the treatment of rectal NET has not been evaluated thoroughly.

Methods

From January 2005 to September 2011, a total of 70 consecutive patients who received EMR-D or endoscopic submucosal dissection (ESD) to treat a rectal NET <16 mm in diameter were included to compare EMR-D with ESD for the treatment of rectal NETs.

Results

The EMR-D group contained 44 patients and the ESD group contained 26 patients. The endoscopic complete resection rate did not differ significantly between the EMR-D and ESD groups (100 % for each). The histological complete resection rate also did not differ significantly between groups (86.3 vs. 88.4 %). The procedure time was shorter for the EMR-D group than for the ESD group (9.75 ± 7.11 vs. 22.38 ± 7.56 min, P < 0.001). Minor bleeding occurred in 1 EMR-D patient and in 3 ESD patients (2.3 vs. 7.6 %). There was no perforation after EMR-D or ESD.

Conclusions

Compared with ESD, EMR-D is technically simple, minimally invasive, and safe for treating small rectal NETs contained within the submucosa. EMR-D can be considered an effective and safe resection method for rectal NETs <16 mm in diameter without metastasis.     

Endoscopic submucosal dissection for gastric cancer: the influence of hospital volume on complications and length of stay

Background

Little information is available about the relationship between hospital volume and the clinical outcome of endoscopic submucosal dissection (ESD) for gastric cancer. The purpose of this study was to investigate the influence of hospital volume on clinical outcomes of ESD using a national administrative database.

Methods

A total of 27,385 patients treated with ESD for gastric cancer were referred to 867 hospitals between 2009 and 2011 in Japan. We collected patients’ data from the administrative database to compare ESD-related complications and length of stay (LOS) in relation to hospital volume. Hospital volume was categorized into three groups based on the number of cases treated over the study period: low-volume hospitals (LVHs, <50 cases), medium-volume hospitals (MVHs, 50–100 cases), and high-volume hospitals (HVHs, >100 cases). These analyses were performed for each location of gastric cancer [upper (cardia and fundus), middle (body), and lower third (antrum and pylorus)].

Results

Significant differences in ESD-related complications among the three hospital volume categories were observed for upper gastric cancer (6.5 % in LVHs vs. 5.2 % in MVHs vs. 3.4 % in HVHs; p = 0.017). Multiple logistic regression revealed that HVHs were significantly associated with decreased relative risk of ESD-related complications in upper gastric cancer (odds ratio for HVHs 0.51; 95 % confidence interval, 0.31–0.83, p = 0.007). However, no significant differences for ESD-related complications were seen for middle and lower gastric cancers among the different hospital volume categories (p > 0.05). Additionally, hospital volume was significantly associated with a decreasing LOS for all locations of gastric cancers (p < 0.001).

Conclusions

The present study has demonstrated that hospital volume was mainly associated with clinical outcome in patients with ESD for upper gastric cancer. Further studies for successive monitoring of outcomes of ESD should be conducted in the near future.     

Feasibility of the trans-umbilical route compared with the trans-oral route in gastric upper body endoscopic submucosal dissection: a porcine model

Background

Total gastrectomy is performed for early gastric cancer in the upper body of the stomach because of the high complication rate of endoscopic submucosal dissection (ESD). The aims of the present animal study in pigs were to verify: (1) the feasibility of the trans-umbilical route compared with the trans-oral route in gastric upper body ESD; (2) the non-inferiority of single port laparoscopic lymph node dissection (LLND) compared with multiport LLND; and (3) the safety of 2-basin LLND (upper greater and lesser curvature).

Methods

We separated the pigs (~40 kg each) into two groups: conventional and experimental (n = 5 per group). We performed ESD in the fundus and upper body anterior wall (UBAW) via the trans-oral route and multiport LLND in the conventional group, and via the trans-umbilical route and single port LLND in the experimental group.

Results

The completion rates, tissue weights, and specimen diameters of both routes showed no statistical differences in either the fundus or the UBAW. The operative time was shorter with the trans-umbilical route than with the trans-oral route in both areas (p < 0.05). In LLND, there were no differences in surgical outcomes between the multiport and single port groups. Intraoperative perforation was seen in the trans-oral route group (n = 1). Delayed perforation was observed in 30 % of the ESD sites.

Conclusions

The trans-umbilical route is feasible and has lower complication rates than the trans-oral route in gastric upper body ESD. Additionally, single port LLND is not inferior to multiport LLND, and one-side-basin dissection is safer than two-side.     

Systematic review and meta-analysis of endoscopic submucosal dissection versus transanal endoscopic microsurgery for large noninvasive rectal lesions

Background

For almost 30 years, transanal endoscopic microsurgery (TEM) has been the mainstay treatment for large rectal lesions. With the advent of endoscopic submucosal dissection (ESD), flexible endoscopy has aimed at en bloc R0 resection of superficial lesions of the digestive tract. This systematic review and meta-analysis compared the safety and effectiveness of ESD and full-thickness rectal wall excision by TEM in the treatment of large nonpedunculated rectal lesions preoperatively assessed as noninvasive.

Methods

A systematic review of the literature published between 1984 and 2010 was conducted (Registration no. CRD42012001882). Data were integrated with those from the original databases requested from the study authors when needed. Pooled estimates of the proportions of patients with en bloc R0 resection, complications, recurrence, and need for further treatment in the ESD and TEM series were compared using random-effects single-arm meta-analysis.

Results

This review included 11 ESD and 10 TEM series (2,077 patients). The en bloc resection rate was 87.8 % (95 % confidence interval [CI] 84.3–90.6) for the ESD patients versus 98.7 % (95 % CI 97.4–99.3 %) for the TEM patients (P < 0.001). The R0 resection rate was 74.6 % (95 % CI 70.4–78.4 %) for the ESD patients versus 88.5 % (95 % CI 85.9–90.6 %) for the TEM patients (P < 0.001). The postoperative complications rate was 8.0 % (95 %, CI 5.4–11.8 %) for the ESD patients versus 8.4 % (95 % CI 5.2–13.4 %) for the TEM patients (P = 0.874). The recurrence rate was 2.6 % (95 % CI 1.3–5.2 %) for the ESD patients versus 5.2 % (95 % CI 4.0–6.9 %) for the TEM patients (P < 0.001). Nevertheless, the rate for the overall need of further abdominal treatment, defined as any type of surgery performed through an abdominal access, including both complications and pathology indications, was 8.4 % (95 % CI 4.9–13.9 %) for the ESD patients versus 1.8 % (95 % CI 0.8–3.7 %) for the TEM patients (P < 0.001).

Conclusions

The ESD procedure appears to be a safe technique, but TEM achieves a higher R0 resection rate when performed in full-thickness fashion, significantly reducing the need for further abdominal treatment.     

Ex vivo comparative study using the Endolifter® as a traction device for enhancing submucosal visualization during endoscopic submucosal dissection

Background

Endoscopic submucosal dissection (ESD) is a technically demanding procedure, and exposure of the submucosa depends on the action of gravity and submucosal injection. The aim of the study was to investigate the effectiveness of the Endolifter^® as a traction device for enhancing submucosal visualization during ESD.

Methods

This was a prospective ex vivo comparative study conducted between September 2010 and March 2011 in the Prince of Wales Hospital. Consecutive ESDs were performed by four experienced endoscopists in an ex vivo ESD model with or without the Endolifter^®. The Endolifter^® allows simultaneous grasping, retracting and lifting of the mucosa during ESD, resulting in exposure of the submucosa. Each of the procedures were recorded and reviewed later by two independent assessors. The outcome measures included the proportion of time that the submucosa was visualized during the procedures (SM ratio), procedural times, perforation rates, amount of submucosal injections, and the difficulty of the procedure.

Results

Forty-eight gastric ESD procedures were performed on the model. The SM ratio was higher in the Endolifter^® group (P = 0.007), particularly for lesions located at the antrum (P < 0.001). The time required for submucosal dissection and the total procedural time were also less in the Endolifter^® group. The endoscopists rated the ESD procedures in the Endolifter^® group as less difficult (P = 0.033).

Conclusions

The Endolifter^® improved submucosal visualization during gastric ESD and reduces the difficulty of performing the procedures. The device may improve the ease of performing ESD in low-volume centers or large mucosal lesions.     

Utility of the Proximal Margin Frozen Section for Resection of Gastric Adenocarcinoma: A 7-Institution Study of the US Gastric Cancer Collaborative

Background

The proximal gastric margin dictates the extent of resection for gastric adenocarcinoma (GAC). The value of achieving negative margins via additional gastric resection after a positive proximal margin frozen section (FS) is unknown.

Methods

The US Gastric Cancer Collaborative includes all patients who underwent resection of GAC at seven institutions from 2000–2012. Intraoperative proximal margin FS data and final permanent section (PS) data were classified as R0 or R1, respectively; positive distal margins were excluded. The primary aim was to evaluate the impact on local recurrence of converting a positive proximal FS-R1 margin to a PS-R0 final margin by additional resection. Secondary endpoints were recurrence-free survival (RFS) and overall survival (OS).

Results

Of 860 patients, 520 had a proximal margin FS and 67 were positive. Of these, 48 were converted to R0 on PS by additional resection. R0 proximal margin was achieved in 447 patients (86 %), PS-R1 in 25 (5 %), and converted FS-R1-to-PS-R0 in 48 (9 %). The median follow-up was 44 months. Local recurrence was significantly decreased in the converted FS-R1-to-PS-R0 group compared to the PS-R1 group (10 vs. 32 %; p = 0.01). Median RFS was similar between the FS-R1-to-PS-R0 and PS-R1 cohorts (25 vs. 20 months; p = 0.49), compared to 37 months for the PS-R0 group. Median OS was similar between the FS-R1-to-PS-R0 conversion and PS-R1 groups (36 vs. 26 months; p = 0.14) compared to 50 months for the PS-R0 group. On multivariate analysis, increasing T-stage and N-stage were associated with worse OS; the FS-R1-to-PS-R0 proximal margin conversion was not significantly associated with improved RFS (p = 0.68) or OS (p = 0.44).

Conclusion

Conversion of a positive intraoperative proximal margin frozen section during gastric cancer resection may decrease local recurrence, but it is not associated with improved RFS or OS. This may guide decisions regarding the extent of resection.