Tunneling endoscopic muscularis dissection for subepithelial tumors originating from the muscularis propria of the esophagus and gastric cardia

Background and aims

Endoscopic resection of esophageal or cardial subepithelial tumors (SETs) originating from the muscularis propria (MP) is rarely done due to the high risk of perforation, fistula formation, and secondary infection. The aim of this study was to evaluate the preliminary clinical feasibility and safety of tunneling endoscopic muscularis dissection (tEMD) for resection of SETs located in the esophagus and gastric cardia

Methods

Twelve patients with SETs originating from the MP of the esophagus (n = 7) or cardia (n = 5) were treated by tEMD. The procedure included creation of a submucosal tunnel to reach the tumor, dissection of the tumor from the surrounding submucosal tissue and the unaffected MP layer, full-thickness resection of the tumor and affected MP, and subsequent closure of the tunnel mucosal entry with endoscopic clips.

Results

The en bloc resection rate was 100 % (seven lesions affected the deep MP so complete MP resection was performed; five lesions affected the superficial MP for a partial MP resection). The average tumor size was 18.5 ± 6.9 (range 10–30) mm. The mean operating time was 78.3 ± 25.5 (range 50–130) min. The histological diagnoses were two gastrointestinal stromal tumors with very low risk, nine leiomyomas, and one schwannoma. Air leakage and effusion included subcutaneous and mediastinal emphysema in eight patients (66.7 %), pneumothorax in four (33.3 %), pneumoperitoneum in three (25.0 %), and small pleural effusion in two (16.7 %). All air leakage and effusion cases were resolved with conservative management. No patient developed delayed hemorrhage and chronic fistula after tEMD. During the mean follow-up time of 7.1 ± 4.3 (range 2–15) months, no tumor recurrence was found in any patient.

Conclusions

tEMD appears to be a feasible minimally invasive and effective treatment for patients with SETs originating from the MP layer of the esophagus and cardia.     

Submucosal tunneling endoscopic resection for small upper gastrointestinal subepithelial tumors originating from the muscularis propria layer

Background

This prospective study was designed to evaluate the safety and efficacy of submucosal tunneling endoscopic resection (STER) for small (≤3 cm) upper gastrointestinal (GI) subepithelial tumors (SETs) originating from the muscularis propria (MP) layer.

Methods

Between August 2011 and February 2013, a total of 85 patients with upper GI SETs originating from the MP layer were treated with STER. The key steps were as follows: (1) locating the tumor by injection of methylene blue or indigo carmine and then creating a submucosal tunnel from 5 cm above the tumor between the submucosal and muscular layers; (2) resecting the tumor by endoscopic resection techniques; (3) closing the mucosal incision site with several clips after the tumor is removed.

Results

Of the 85 SETs, 60 were located in the esophagus, 16 in the cardia, and 9 in the stomach. STER was successfully performed in all cases (success rate: 100 %). The mean tumor size was 19.2 mm. The mean procedure time was 57.2 min. The average hospital stay after the procedure was 5.9 days. Pathological diagnosis of the tumors were leiomyoma (65/85), gastrointestinal stromal tumor (GIST) (19/85), and calcifying fibrous tumor (1/85). During the procedure, eight patients developed pneumothorax, subcutaneous emphysema, and/or pneumoperitoneum. These patients recovered after conservative treatment. The rate of all complications was significantly higher for lesions originating in the deeper MP layer (70 %) than in the superficial MP layer (1.3 %; p < 0.001). The total complication rate for different histological diagnoses was also significantly different (26.3 % for GISTs, 4.6 % for leiomyomas, 0 % for calcifying fibrous tumors, p < 0.05). No residual or recurrent tumors were detected during the follow-up period (median: 8 months).

Conclusions

Submucosal tunneling endoscopic resection appears to be a feasible, safe, and effective procedure for treatment of small (≤3 cm) upper GI SETs originating from the MP layer.     

Complete defect closure of gastric submucosal tumors with purse-string sutures

Background

Gastric submucosal tumors (SMTs) originating from the muscularis propria layer are treated endoscopically. Successful closure of the wall defect is a critical step. This study evaluated the safety and feasibility of the endoscopic purse-string suture (EPSS) method using an endoloop and several metallic clips after endoscopic full-thickness resection (EFTR) or perforation due to endoscopic submucosal dissection (ESD).

Methods

From December 2009 to April 2013, 30 patients with SMTs originating from the muscularis propria layer who received EFTR or ESD were retrospectively analyzed. After successful tumor resection, an endoloop was anchored onto the circumferential margin of the gastric defect with several metallic clips and tightened gently. Patient characteristics, tumor size, en bloc resection, and postoperative complications were evaluated.

Results

For all 30 patients, EPSS was successfully performed after EFTR or perforation due to ESD. The mean diameter of the resected specimen was 1.9 cm. No severe complications occurred during or after the procedure. The lesions were healed 1 month after the procedure, as confirmed endoscopically.

Conclusion

The EPSS method using an endoloop and clips is an effective and safe technique for closing the gastric defect after EFTR or perforation due to ESD.     

Endoscopic muscularis dissection for upper gastrointestinal subepithelial tumors originating from the muscularis propria

Background and aims

Based on our experience with endoscopic submucosal dissection (ESD) and new endoscopic techniques for endoscopic closure of iatrogenic upper gastrointestinal (upper-GI) perforations, we developed methods to remove upper-GI subepithelial tumors (SETs) originating from the muscularis propria by endoscopic?muscularis dissection (EMD). The aim of this study is to evaluate the clinical feasibility and safety of EMD.

Methods

31 patients with upper-GI SETs originating from the muscularis propria were treated by EMD. The EMD differed from ESD in (1) precutting the overlying mucosa above the lesion by using snare or longitudinal incision instead of circumferential incision, (2) dissecting the complete tumors away from submucosal and muscularis propria tissue by electrical dissection combined with blunt dissection, and (3) closing the wound with clips. Perforations occurring during dissection were closed by endoscopic methods.

Results

30 of 31 tumors were resected?completely (96.8 %). One esophageal lesion was resected partially because of severe adhesions with surrounding tissue. Mean resected tumor size was 22.1?mm?×?15.5?mm, and mean operation time was 76.8?min (range 15–330?min). Histological diagnosis was gastrointestinal stromal tumor (GIST) in 16 lesions [6 esophageal, 3 cardial, 7 gastric; 6 very low risk and 10 low risk according to the National Institutes of Health (NIH) risk classification] and leiomyoma in 15 lesions (8 esophageal, 4 cardial, 3 gastric). No patient developed delayed hemorrhage. Perforation occurred in four patients (12.9 %), all of which were managed successfully by endoscopic techniques. The mean follow-up time was 17.7?months (range 7–35?months). Follow-up found no tumor recurrence in any patient.

Conclusions

In this early experience, EMD appears to be a feasible and minimally invasive treatment for some patients with upper-GI SETs originating from the muscularis propria. Although there is a higher risk of perforation than with ESD, this will improve with extended practice, and perforations have become manageable endoscopically.     

Endoscopic enucleation for gastric subepithelial tumors originating in the muscularis propria layer

Background  

Subepithelial tumors (SETs) of the stomach are considered benign. However, they have the potential for malignant transformation, especially if they originate in the muscularis propria layer. This study aimed to determine the feasibility of endoscopic enucleation (EEN) for SETs in the muscularis propria layer and to evaluate the diagnostic efficacy and safety of EEN for SETs.     

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.     

Impact of cumulative time on the clinical outcomes of endoscopic submucosal dissection in gastric neoplasm

Background

Endoscopic submucosal dissection (ESD) can be technically demanding and requires great attention to detail and prolonged concentration. We assumed that clinical outcomes of ESDs may be affected by cumulative time, and we aimed to compare complete resection rates and adverse events according to cumulative ESD time.

Methods

This study involved 1,328 consecutive patients with 1,461 gastric tumors who underwent ESD from January 2008 to July 2011 in a tertiary-care academic medical center. The main outcome measurements were en bloc resection rate, complete resection rate, bleeding rate and perforation rate.

Results

Patients were divided into three groups according to cumulative time intervals (<2 h vs. 2–4 h vs. ≥4 h). Complete resection rate did not differ among the three groups, but early post-ESD bleeding (EPEB) rate was significantly different among the three groups (2.5 vs. 3.5 % vs. 6.6 %, P = 0.040). In multivariate analysis, cumulative time period was an independent predictor of EPEB (2–4 h odds ratio [OR] 2.29, 95 % confidence interval [CI] 1.05–5.01, P = 0.038; ≥4 h OR 3.99; 95 % CI, 2.15–7.65, P < 0.001). The rate of perforation was higher in ESDs performed after completing prior endoscopies or outpatient clinic session compared to those performed without prior work (3.8 vs. 1.6 %, P = 0.004). Moreover, prior workload before ESD was an independent predictor of perforation in multivariate analysis (OR 2.77, 95 % CI, 1.37–5.60, P = 0.005).

Conclusions

Our data suggest that cumulative ESD time did not influence en bloc or complete resection rate of ESD, but increased the rate of acute bleeding. Moreover, prior workload before ESDs may increase the risk of perforation.     

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.     

Significant Variation of Resected Meso-esophageal Tissue Volume in Two-Stage Subtotal Esophagectomy Specimens: A Retrospective Morphometric Study

Background

Differences in the extent and quality of surgical resection for esophageal cancer may influence the pathological staging and patient outcome. There are no data in the literature qualitatively and/or quantitatively characterizing esophagectomy specimens.

Methods

Macroscopic images of 161 esophagectomy specimens were analyzed retrospectively. The extent of resection was qualitatively classified as “muscularis propria,” “intra-meso-esophageal,” or “meso-esophageal.” The volume of meso-esophageal tissue was quantified morphometrically. The number of muscle defects per specimen was counted. Results were related to clinicopathological variables, including survival.

Results

Sixty-two (39 %) specimens were classified as “muscularis propria,” 65 (40 %) as “intra-meso-esophageal,” and 34 (21 %) as “meso-esophageal.” The morphometrically measured meso-esophageal tissue volume was different between the three types (P < 0.001). The specimen type was related to the total number of lymph nodes (P = 0.02), number of metastatic lymph nodes (P = 0.024), and depth of tumor invasion (P = 0.013), but not related to extramural tumor volume, circumferential resection margin status, or the surgeon performing the resection. The number of muscle defects per specimen was similar in all resection types. The resection specimen classification was related to survival in patients treated by surgery alone (P = 0.027).

Conclusions

This is the first study to quantify and classify the volume of tissue resected during esophagectomy. Our study shows significant variation of the resected tissue volume impacting pathological tumor staging. This variation was not associated with individual surgeon performance. A prospective, multicenter study is needed to validate our results and to investigate the potential biological mechanisms influencing the resectable volume of meso-esophageal tissue in cancer patients.     

Endoscopic full-thickness resection with defect closure using clips and an endoloop for gastric subepithelial tumors arising from the muscularis propria

Background and aims

This retrospective study evaluated the safety and efficacy of endoscopic full-thickness resection (eFTR) with defect closure using clips and an endoloop for the treatment of gastric subepithelial tumors (SETs) arising from the muscularis propria (MP).

Methods

From January 2009 to December 2012, 51 patients with gastric SETs arising from the MP underwent eFTR with defect closure using clips and an endoloop. The key steps were (1) several milliliters of mixture solution was injected into the submucosa after dots were marked around the tumor; (2) a cross incision was made in the mucosa to reveal the tumor; (3) subsequently, circumferential excavation was performed as deep as the muscularis propria, and full-thickness resection of the tumor was performed with an insulated-tip knife, including its underlying MP and serosa; (4) the gastric wall defect was closed with clips and an endoloop was then placed to fix and tighten all of the clips together.

Results

Successful complete resection by eFTR was achieved in 50 cases (98.0 %). One case failed and was converted into a laparoscopic resection due to the tumor falling into the peritoneal cavity during the procedure. The mean procedure time was 52 min. No patients had severe complications, such as massive bleeding, delayed bleeding, peritonitis, or gastrointestinal tract leakage. The mean tumor length was 2.4 cm. Pathological diagnoses of the tumors were leiomyomas (21/51) and gastrointestinal stromal tumors (30/51). The median follow-up period after the procedure was 22.4 months (range 1–48 months), and no residual tumor or tumor recurrence was detected during the follow-up period.

Conclusions

eFTR with defect closure with clips and an endoloop appears to be a safe and effective technique for the treatment of patients with gastric SETs originating from the MP, especially for those with extraluminal growth or adhesions to the MP.     

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.     

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.     

Factors affecting the technical difficulty and clinical outcome of endoscopic submucosal dissection for colorectal tumors

Background

Endoscopic submucosal dissection (ESD) for colorectal tumors is technically difficult due to the anatomy of the large intestine, with its narrow lumen, thin walls, and redundancy. Here, we assessed factors associated with incomplete resection and difficult colorectal ESD.

Methods

Between November 2009 and April 2013, we performed ESD on 151 consecutive colorectal tumors in 147 patients. We evaluated the clinical outcomes of all cases and conducted multiple logistic regression analysis of the following factors related to incomplete resection and difficult procedure: age, gender, location (right colon, left colon or rectum), tumor size (diameter ≥40 or <40 mm), operation time, morphology [granular-type laterally spreading tumor (LST-G), non-granular-type laterally spreading tumor (LST-NG), or protruded type], fibrosis, and paradoxical movement during the procedure. A procedure that required more than 120 min was defined as a difficult colorectal ESD.

Results

Average tumor size was 32.1 ± 10.7 mm, and the average procedure length was 71.8 ± 49.5 min. The rate of en bloc resection was 94.7 %, while that of en bloc curative resection was 86.8 %. Perforation occurred in 1.3 % of the ESD procedures. Multivariate logistic regression analysis revealed that only severe fibrosis [odds ratio (OR) 4.51; 95 % confidence interval (CI) 1.36–14.91, p = 0.014] contributed to incomplete resection and that a tumor size exceeding 40 mm (OR 5.73 [95 % CI 1.66–19.74], p = 0.006), severe fibrosis (OR 23.31 [95 % CI 6.59–82.54], p < 0.001), and paradoxical movement (OR 4.26 [95 % CI 1.11–16.44], p = 0.035) were independent factors exacerbating the difficulty of colorectal ESD.

Conclusions

Severe fibrosis contributed to both incomplete resection and difficult colorectal ESD. Larger tumor size and paradoxical movement during the procedure were independent factors contributing to the difficulty of colorectal ESD. These factors might enable endoscopists to develop strategies for treating colorectal ESD.     

Ex vivo pig training model for esophageal endosopic submucosal dissection (ESD) for endoscopists with experience in gastric ESD

Background

Esophageal endoscopic submucosal dissection (ESD) has developed in recent years because of its high rate of en bloc resection. However, for many endoscopists, technical difficulty and risks of complications are great barriers to performing esophageal ESD. In this study, we developed an original training model for esophageal ESD using isolated pig esophagus and assessed this ex vivo model in endoscopists with experience in gastric ESD.

Methods

Three endoscopists without experience in esophageal ESD but with some experience in gastric ESD performed esophageal ESD of artificial lesions in 10 consecutive sessions using this ex vivo model. The en bloc resection rate, operation time, number of muscularis propria layer injuries, and presence of perforation were recorded. We evaluated the effectiveness of this training in the three endoscopists by comparing results from the first five sessions (former period) with those from the last five sessions (latter period).

Results

All three endoscopists achieved en bloc resections in all trials. In the former period, injury to the muscularis propria layer for each of the three endoscopists occurred a mean of 2.2 (1–3), 0.6 (0–1), and 3.2 (1–6) times, respectively. Perforation occurred in one session performed by one endoscopist. In the latter period, the mean number of muscularis propria layer injuries for each of the three endoscopists decreased to 0.2 (0–1), 0.2 (0–1), and 0.8 (0–2), respectively. The time of operation shortened from 35.0 (25–40), 36.4 (30–50), and 29.8 (23–43)?min to 23.0 (16–31), 25.6 (23–28), and 29.2 (21–37)?min, respectively.

Conclusions

This original ex vivo training model was helpful to endoscopists with experience in gastric ESD in acquiring the basic skills for performing esophageal ESD.     

Gastric ischemic conditioning increases neovascularization and reduces inflammation and fibrosis during gastroesophageal anastomotic healing

Background

The incidence of anastomotic leak and stricture after esophagectomy remains high. Gastric devascularization followed by delayed esophageal resection has been proposed to minimize these complications. We investigated the effect of ischemic conditioning duration on anastomotic wound healing in an animal model of esophagogastrectomy.

Methods

North American opossums were randomized to four study groups. Group A underwent immediate resection and gastroesophageal anastomosis. Groups B, C, and D were treated with delayed resection and anastomosis after a gastric ischemic conditioning period of 7, 30, and 90 days, respectively. Gastric conditioning was performed by ligating the left, right, and short gastric vessels. An intraabdominal esophagogastric resection and anastomosis was performed, followed by euthanasia 10 days later. Outcome variables included anastomotic bursting pressure, microvessel concentration, tissue inflammation, and collagen deposition.

Results

Twenty-four opossums were randomized to groups A (n = 7), B (n = 8), C (n = 5), and D (n = 4). Subclinical anastomotic leak was discovered at necropsy in 5 animals: 3 in group A, and 1 each in groups B and C (p = 0.295). The anastomotic bursting pressure did not differ significantly between groups (p = 0.545). A 7 day ischemic conditioning time did not produce increased neovascularity (p = 0.900), but animals with a 30 day conditioning time showed significantly increased microvessel counts compared to unconditioned animals (p = 0.016). The degree of inflammation at the healing anastomosis decreased significantly as the ischemic conditioning period increased (p = 0.003). Increasing delay interval was also associated with increased muscularis propria preservation (p = 0.001) and decreased collagen deposition at the healing anastomosis (p = 0.020).

Conclusions

Animals treated with 30 days of gastric ischemic conditioning showed significantly increased neovascularity and muscularis propria preservation and decreased inflammation and collagen deposition at the healing anastomosis. These data suggest that an ischemic conditioning period longer than 7 days is required to achieve the desired effect on wound healing.     

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.     

Endoscopic full-thickness resection without laparoscopic assistance for gastric submucosal tumors originated from the muscularis propria

Background

This study was designed to evaluate the clinical efficacy, safety, and feasibility of endoscopic full-thickness resection (EFR) for gastric submucosal tumors (SMTs) originated from the muscularis propria.

Methods

Twenty-six patients with gastric SMTs originated from the muscularis propria were treated by EFR between July 2007 and January 2009. EFR technique consists of five major procedures: (1) injecting normal saline into the submucosa and precutting the mucosal and submucosal layer around the lesion; (2) a circumferential incision as deep as muscularis propria around the lesion by the endoscopic submucosal dissection (ESD) technique; (3) incision into serosal layer around the lesion with Hook knife; (4) completion of full-thickness incision to the tumor including the serosal layer with Hook, IT, or snare by gastroscopy without laparoscopic assistance; (5) closure of the gastric-wall defect with metallic clips.

Results

EFR was successfully performed in all 26 patients without laparoscopic assistance. The complete resection rate was 100%, and the mean operation time was 105 (range, 60?C145)?min. The mean resected lesion size was 2.8 (range, 1.2?C4.5)?cm. Pathological diagnosis of these lesions included gastrointestinal stromal tumors (GISTs) (16/26), leiomyomas (6/26), glomus tumors (3/26), and Schwannoma (1/26). No gastric bleeding, peritonitis sign, or abdominal abscess occurred after EFR. No lesion residual or recurrence was found during the follow-up period (mean, 8?months; range, 6?C24?months).

Conclusions

EFR seems to be an efficacious, safe, and minimally invasive treatment for patients with gastric SMT, which makes it possible to resect deep gastric lesion and provide precise pathological diagnosis of it. With the development of EFR, the indication of endoscopic resection may be expanded.     

A tailored approach for endoscopic treatment of small rectal neuroendocrine tumor

Introduction

Resection of rectal neuroendocrine tumors (NETs) less than 1 cm in diameter can be performed using various endoscopic techniques. Endoscopic mucosal resection (EMR) traditionally had suboptimal complete resection rate compared to endoscopic submucosal resection with band ligation (ESMR-L). However, the previous studies did not consider the characteristics of rectal NETs. The aim of our study is to compare the efficacy of ESMR-L and EMR using tailored approach according to the characteristics of rectal NETs.

Methods

82 rectal NETs in 77 patients treated by ESMR-L (n = 48) or EMR (n = 34) between September 2007 and October 2012 were retrospectively analyzed. ESMR-L was used for flat-type tumors or tumors with non-lifting sign after submucosal injection. Conventional EMR was used for elevated-type tumors or tumors with well-lifting sign after submucosal injection.

Results

The pathological complete resection rate was higher in the ESMR-L group (45 lesions, 93.8 %) compared with the EMR group (30 lesions, 88.2 %); however, this difference was not significant (p = 0.441). Overall complication did not differ significantly between the ESMR-L group and the EMR group (p = 0.774). There was one case of a remnant lesion in the ESMR-L group, which was managed by EMR after circumferential pre-cutting (EMR-P), and no recurrence has been detected in either the ESMR-L or EMR group.

Conclusions

ESMR-L and EMR procedures could have a similar excellent complete resection rate, if we select the endoscopic resection technique according to the characteristics of the small rectal NETs.