Snare Tip Soft Coagulation vs Argon Plasma Coagulation vs No Margin Treatment After Large Nonpedunculated Colorectal Polyp Resection: a Randomized Trial.

BACKGROUND & AIMS: Thermal treatment of the defect margin after endoscopic mucosal resection (EMR) of large nonpedunculated colorectal lesions reduces the recurrence rate. Both snare tip soft coagulation (STSC) and argon plasma coagulation (APC) have been used for thermal margin treatment, but there are few data directly comparing STSC with APC for this indication. METHODS: We performed a randomized 3-arm trial in 9 US centers comparing STSC with APC with no margin treatment (control) of defects after EMR of colorectal nonpedunculated lesions ≥15 mm. The primary end point was the presence of residual lesion at first follow-up. RESULTS: There were 384 patients and 414 lesions randomized, and 308 patients (80.2%) with 328 lesions completed ≥1 follow-up. The proportion of lesions with residual polyp at first follow-up was 4.6% with STSC, 9.3% with APC, and 21.4% with control subjects (no margin treatment). The odds of residual polyp at first follow-up were lower for STSC and APC when compared with control subjects (P = .001 and P = .01, respectively). The difference in odds was not significant between STSC and APC. STSC took less time to apply than APC (median, 3.35 vs 4.08 minutes; P = .019). Adverse event rates were low, with no difference between arms. CONCLUSIONS: In a randomized trial STSC and APC were each superior to no thermal margin treatment after EMR. STSC was faster to apply than APC. Because STSC also results in lower cost and plastic waste than APC (APC requires an additional device), our study supports STSC as the preferred thermal margin treatment after colorectal EMR. (Clinicaltrials.gov, Number NCT03654209.).

Efficacy, Feasibility, and Safety of the X-Tack Endoscopic HeliX Tacking System: A Multicenter Experience.

BACKGROUND AND AIMS: The application of endoscopic suturing has revolutionized defect closures. Conventional over-the-scope suturing necessitates removal of the scope, placement of the device, and reinsertion. A single channel, single sequence, through-the-scope suturing device has been developed to improve this process. This study aims to describe the efficacy, feasibility, and safety of a through-the-scope suturing device for gastrointestinal defect closure. METHODS: This was a retrospective multicenter study involving 9 centers of consecutive adult patients who underwent suturing using the X-Tack Endoscopic HeliX Tacking System (Apollo Endosurgery). The primary outcomes were technical success and long-term clinical success. Secondary outcomes included adverse events, recurrence, and reintervention rates. RESULTS: In all, 56 patients (mean age 53.8, 33 women) were included. Suturing indications included fistula repair (n=22), leak repair (n=7), polypectomy defect closure (n=12), peroral endoscopic myotomy (POEM) site closure (n=7), perforation repair (n=6), and ulcers (n=2). Patients were followed at a mean duration of 74 days. Overall technical and long-term clinical success rates were 92.9% and 75%, respectively. Both technical and clinical success rates were 100% for polypectomies, POEM-site closures, and ulcers. Success rates were lower for the repair of fistulas (95.5% technical, 54.5% clinical), leaks (57.1%, 28.6%), and perforations (100%, 66.7%). No immediate adverse events were noted. CONCLUSION: This novel, through-the-scope endoscopic suturing system, is a safe and feasible method to repair defects that are ≤3 cm. The efficacy of this device may be better suited for superficial defects as opposed to full-thickness defects. Larger defects will need more sutures and probably a double closure technique to provide a reinforcement layer.

Does successful EUS-guided pancreatic cyst chemoablation safely allow reduction in the frequency of radiographic surveillance? Long-term follow-up of randomized prospective data.

BACKGROUND AND AIMS: EUS-guided pancreatic cyst chemoablation is safe and effective for appropriately selected patients; however, the proper frequency of radiographic surveillance after successful chemoablation is unknown. Here we report the long-term follow-up of two randomized, prospective, ChARM clinical trials. Additionally, the performance of a post-ablation reduced radiographic surveillance protocol was evaluated using clinical and economic outcomes and patient experience metrics. METHODS: Patients who successfully completed one of the two ChARM randomized control trials were evaluated for durability of response and clinical outcomes. Patients were eligible if two years or more of follow-up were available and complete. We calculated economic outcomes using Medicare allowable costs applicable to EUS, MRI, and outpatient clinic visits. We modeled costs of a patient followed by the ChARM Post-treatment Reduced Radiographic Surveillance Protocol compared with a similar patient followed under Fukuoka or ACG guidelines over 5 years. Additionally, patients under long-term surveillance in our clinic were interviewed via a 4 question Likert scale questionnaire. RESULTS: 52 patients were eligible and included in the study. At the most recent follow-up of the 52 patients, 36 (69.2%) achieved complete response, an additional 11 (21.2%) showed partial response, and only 5 (9.6%) with nonresponse. All patients were successfully reduced to annual or less surveillance without recurrence or the development of cyst associated malignancy. When compared with Fukukoa or ACG guidelines, a patient treated and followed under the ChARM Post-Treatment Reduced Radiographic Surveillance Protocol incurred a Medicare allowable cost of $7,200.00 versus $19,437.44 and $12,526.52 if untreated and followed under Fukukoa or ACG guidelines, respectively. The patient experience questionnaire was returned completed by 49 participants. CONCLUSIONS: The ChARM Post-Treatment Reduced Radiographic Surveillance Protocol safely allows a reduction in radiographic surveillance. A reduction in cost associated with cyst management under the ChARM protocol was shown when compared to management following Fukukoa or ACG guidelines. According to the questionnaire, most patients reported a moderate level of logistical and emotional burden associated with MRI surveillance, and a majority were in favor of reducing the frequency of radiographic surveillance if it can be done without a marked increase in oncologic risk.

Clip Closure Does Not Reduce Risk of Bleeding After Resection of Large Serrated Polyps: Results From a Randomized Trial.

BACKGROUND & AIMS: Serrated polyps are important colorectal cancer precursors and are most commonly located in the proximal colon, where post-polypectomy bleeding rates are higher. There is limited clinical trial evidence to guide best practices for resection of large serrated polyps (LSPs). METHODS: In a multicenter trial, patients with large (≥20 mm) non-pedunculated polyps undergoing endoscopic mucosal resection (EMR) were randomized to clipping of the resection base or no clipping. This analysis is stratified by histologic subtype of study polyp(s), categorized as serrated [sessile serrated lesions (SSLs) or hyperplastic polyps (HPs)] or adenomatous, comparing clip vs control groups. The primary outcome was severe post-procedure bleeding within 30 days of colonoscopy. RESULTS: A total of 179 participants with 199 LSPs (191 SSLs and 8 HPs) and 730 participants with 771 adenomatous polyps were included in the study. Overall, 5 patients with LSPs (2.8%) experienced post-procedure bleeding compared with 42 (5.8%) of those with adenomas. There was no difference in post-procedure bleeding rates between patients in the clip vs control group among those with LSPs (2.3% vs 3.3%, respectively, difference 1.0%; P = NS). However, among those with adenomatous polyps, clipping was associated with a lower risk of post-procedure bleeding (3.9% vs 7.6%, difference 3.7%; P = .03) and overall serious adverse events (5.5% vs 10.6%, difference 5.1%; P = .01). CONCLUSION: The post-procedure bleeding risk for LSPs removed via EMR is low, and there is no discernable benefit of prophylactic clipping of the resection base in this group. This study indicates that the benefit of endoscopic clipping following EMR may be specific for >2 cm adenomatous polyps located in the proximal colon. CLINICALTRIALS: gov, Number: NCT01936948.

The Durability of EUS-Guided Chemoablation of Mucinous Pancreatic Cysts: A Long-Term Follow-Up of the CHARM trial.

Pancreatic cancer has known precursor lesions with potential to develop into malignancy over time. At least 20% of pancreatic cancer evolves from mucinous cystic neoplasms and intraductal papillary mucinous neoplasms, which are often discovered incidentally.1,2 Current guidelines for the management of mucinous cystic neoplasms and intraductal papillary mucinous neoplasms include long-term surveillance, which is expensive and nontherapeutic, or surgical resection, which is associated with major risk and may not be an option for patients with significant concomitant illness.3.

EMR combined with hybrid argon plasma coagulation to prevent recurrence of large nonpedunculated colorectal polyps (with videos).

BACKGROUND AND AIMS: EMR is the mainstay of therapy for large colorectal polyps. Local recurrence after EMR is common and can be reduced using margin ablation. Our aim was to evaluate recurrence rates when using hybrid argon plasma coagulation (h-APC) ablation after EMR. METHODS: Adult patients (aged 18-89 years) undergoing EMR of nonpedunculated colorectal polyps ≥20 mm were enrolled in a prospective multicenter study. h-APC was used to ablate all defect margins and also the resection surface in selected cases. The primary study outcome was recurrence rates found during the first follow-up colonoscopy. Secondary outcomes were technical success and adverse event rates. RESULTS: EMR with h-APC ablation was used in 101 polyps (84 patients, 46.4% women). EMR with h-APC ablation was technically successful in all cases (median EMR time, 15 minutes; median h-APC ablation time, 4 minutes). Median polyp size was 30 mm (range, 20-60). Resected polyps were either adenomas (68/101 [67.3%]), sessile serrated lesions (27/101 [27%]), or adenocarcinomas (6/101 [6%]). The post-EMR recurrence rate was 2.2% (2/91) (95% confidence interval, .27-7.71). All 6 patients with cancer (intramucosal cancer, 4; T1sm cancer, 2) were found to have complete eradication of the primary tumor after EMR with h-APC, and none had lymph node metastasis. Four serious adverse events occurred in 3 patients (2 delayed bleeding [2.4%], 1 abdominal pain [1.2%], and 1 microperforation [1.2%]. All serious adverse events resolved with either endoscopic or antibiotic treatment only. CONCLUSIONS: EMR with h-APC showed a high technical success rate, low adverse event rate, and very low post-EMR recurrence rates. (Clinical trial registration number: NCT04015765.).

Hybrid argon plasma coagulation-assisted endoscopic mucosal resection for large sessile colon polyps to reduce local recurrence: a prospective pilot study.

BACKGROUND: Endoscopic mucosal resection (EMR) of large, sessile colon polyps often results in incomplete resection with subsequent recurrence. The aim of this prospective pilot study was to evaluate the efficacy and safety of a novel technique, hybrid argon plasma coagulation-assisted EMR (hAPC-EMR), to remove large, sessile polyps. METHODS: 40 eligible patients underwent hAPC-EMR for the removal of one or more nonpedunculated colon polyps ≥ 20 mm. Participants were contacted 30 days post-procedure to assess for adverse events and were recommended to return for a surveillance colonoscopy at 6 months to assess for local recurrence. RESULTS: At the time writing, 32 patients with 35 polyps (median size 27 mm; interquartile range 14.5 mm) resected by hAPC-EMR had undergone the 6-month follow-up colonoscopy. Recurrence rate was 0 % (95 % confidence interval [CI] 0-0) at follow-up. Post-polypectomy bleeding was experienced by three patients (7.5 %; 95 %CI 0.00-0.15), and no patients developed post-polypectomy syndrome. CONCLUSION: These preliminary results showed 0 % local recurrence rate at 6 months and demonstrated the safety profile of hAPC-EMR. A large, randomized, controlled trial is required to confirm these results.

Effects of Blended (Yellow) vs Forced Coagulation (Blue) Currents on Adverse Events, Complete Resection, or Polyp Recurrence After Polypectomy in a Large Randomized Trial.

BACKGROUND & AIMS: There is debate over the type of electrosurgical setting that should be used for polyp resection. Some endoscopists use a type of blended current (yellow), whereas others prefer coagulation (blue). We performed a single-blinded, randomized trial to determine whether type of electrosurgical setting affects risk of adverse events or recurrence. METHODS: Patients undergoing endoscopic mucosal resection of nonpedunculated colorectal polyps 20 mm or larger (n = 928) were randomly assigned, in a 2 × 2 design, to groups that received clip closure or no clip closure of the resection defect (primary intervention) and then to either a blended current (Endocut Q) or coagulation current (forced coagulation) (Erbe Inc) (secondary intervention and focus of the study). The study was performed at multiple centers, from April 2013 through October 2017. Patients were evaluated 30 days after the procedure (n = 919), and 675 patients underwent a surveillance colonoscopy at a median of 6 months after the procedure. The primary outcome was any severe adverse event in a per patient analysis. Secondary outcomes were complete resection and recurrence at first surveillance colonoscopy in a per polyp analysis. RESULTS: Serious adverse events occurred in 7.2% of patients in the Endocut group and 7.9% of patients in the forced coagulation group, with no significant differences in the occurrence of types of events. There were no significant differences between groups in proportions of polyps that were completely removed (96% in the Endocut group vs 95% in the forced coagulation group) or the proportion of polyps found to have recurred at surveillance colonoscopy (17% and 17%, respectively). Procedural characteristics were comparable, except that 17% of patients in the Endocut group had immediate bleeding that required an intervention, compared with 11% in the forced coagulation group (P = .006). CONCLUSIONS: In a randomized trial to compare 2 commonly used electrosurgical settings for the resection of large colorectal polyps (Endocut vs forced coagulation), we found no difference in risk of serious adverse events, complete resection rate, or polyp recurrence. Electrosurgical settings can therefore be selected based on endoscopist expertise and preference. Clinicaltrials.gov ID NCT01936948.

Factors associated with complete clip closure after endoscopic mucosal resection of large colorectal polyps.

BACKGROUND AND STUDY AIM : Delayed bleeding is a common adverse event following endoscopic mucosal resection (EMR) of large colorectal polyps. Prophylactic clip closure of the mucosal defect after EMR of nonpedunculated polyps larger than 20 mm reduces the incidence of severe delayed bleeding, especially in proximal polyps. This study aimed to evaluate factors associated with complete prophylactic clip closure of the mucosal defect after EMR of large polyps. METHODS : This is a post hoc analysis of the CLIP study (NCT01936948). All patients randomized to the clip group were included. Main outcome was complete clip closure of the mucosal resection defect. The defect was considered completely closed when no remaining mucosal defect was visible and clips were less than 1 cm apart. Factors associated with complete closure were evaluated in multivariable analysis. RESULTS : In total, 458 patients (age 65, 58 % men) with 494 large polyps were included. Complete clip closure of the resection defect was achieved for 338 polyps (68.4 %); closure was not complete for 156 (31.6 %). Factors associated with complete closure in adjusted analysis were smaller polyp size (odds ratio 1.06 for every millimeter decrease [95 % confidence interval 1.02-1.08]), good access (OR 3.58 [1.94-9.59]), complete submucosal lifting (OR 2.28 [1.36-3.90]), en bloc resection (OR 5.75 [1.48-22.39]), and serrated histology (OR 2.74 [1.35-5.56]). CONCLUSIONS : Complete clip closure was not achieved for almost one in three resected large nonpedunculated polyps. While stable access and en bloc resection facilitate clip closure, most factors associated with clip closure are not modifiable. This highlights the need for alternative closure options and measures to prevent bleeding.

Clip Closure Prevents Bleeding After Endoscopic Resection of Large Colon Polyps in a Randomized Trial.

BACKGROUND & AIMS: Bleeding is the most common severe complication after endoscopic mucosal resection of large colon polyps and is associated with significant morbidity and cost. We examined whether prophylactic closure of the mucosal defect with hemoclips after polyp resection reduces the risk of bleeding. METHODS: We performed a multicenter, randomized trial of patients with a large nonpedunculated colon polyp (≥20 mm) at 18 medical centers in North America and Spain from April 2013 through October 2017. Patients were randomly assigned to groups that underwent endoscopic closure with a clip (clip group) or no closure (control group) and followed. The primary outcome, postprocedure bleeding, was defined as a severe bleeding event that required hospitalization, a blood transfusion, colonoscopy, surgery, or another invasive intervention within 30 days after completion of the colonoscopy. Subgroup analyses included postprocedure bleeding with polyp location, polyp size, or use of periprocedural antithrombotic medications. We also examined the risk of any serious adverse event. RESULTS: A total of 919 patients were randomly assigned to groups and completed follow-up. Postprocedure bleeding occurred in 3.5% of patients in the clip group and 7.1% in the control group (absolute risk difference [ARD] 3.6%; 95% confidence interval [CI] 0.7%-6.5%). Among 615 patients (66.9%) with a proximal large polyp, the risk of bleeding in the clip group was 3.3% and in the control group was 9.6% (ARD 6.3%; 95% CI 2.5%-10.1%); among patients with a distal large polyp, the risks were 4.0% in the clip group and 1.4% in the control group (ARD -2.6%; 95% CI -6.3% to -1.1%). The effect of clip closure was independent of antithrombotic medications or polyp size. Serious adverse events occurred in 4.8% of patients in the clip group and 9.5% of patients in the control group (ARD 4.6%; 95% CI 1.3%-8.0%). CONCLUSIONS: In a randomized trial, we found that endoscopic clip closure of the mucosal defect following resection of large colon polyps reduces risk of postprocedure bleeding. The protective effect appeared to be restricted to large polyps located in the proximal colon. ClinicalTrials.gov no: NCT01936948.

EUS-Guided Pancreatic Cyst Ablation: a Clinical and Technical Review.

PURPOSE OF REVIEW: Pancreatic cystic lesions represent a growing public health dilemma, particularly as our population ages and cross-sectional imaging becomes more sensitive. Mucinous cysts carry a clinically significant risk of developing pancreatic cancer, which carries an extremely poor prognosis. Determining which cysts will develop cancer may be challenging, and surgical resection of the pancreas carries significant morbidity. The goal of this paper is to review the rationale for cyst ablation and discuss prior and current research on cyst ablation techniques and efficacy. Indications, contraindications, and factors related to optimal patient selection are outlined. RECENT FINDINGS: Endoscopic ultrasound-guided chemoablation of pancreatic cysts has been performed in neoplastic cysts, with varying levels of efficacy. Safety concerns arose due to the risk of pancreatitis in alcohol-based treatments; however, the most recent data using a non-alcohol chemoablation cocktail suggests that ablation is effective without the need for alcohol, resulting in a significantly more favorable adverse event profile. Endoscopic ultrasound-guided chemoablation of neoplastic pancreatic cysts is a promising, minimally invasive approach for treatment of cysts, with recent significant advances in safety and efficacy, suggesting that it should play a role in the treatment algorithm.

The Safety and Efficacy of an Alcohol-Free Pancreatic Cyst Ablation Protocol.

BACKGROUND & AIMS: Endoscopic ultrasound (EUS)-guided chemoablation with ethanol lavage followed by infusion of paclitaxel is effective for the treatment of mucinous pancreatic cysts. However, complications arise in 3%-10% of patients, presumably linked to the inflammatory effects of ethanol. We aimed to determine whether alcohol is required for effective pancreatic cyst ablation, if removing alcohol from the ablation process would improve complication rates, and whether a multi-agent chemotherapeutic cocktail could increase the rate of complete cyst resolution compared with findings reported from previous trials using alcohol followed by paclitaxel alone. METHODS: Between November 2011 and December 2016, we conducted a single-center, prospective, double-blind trial of 39 patients with mucinous-type pancreatic cysts. Patients were randomly assigned to 1 of 2 groups that underwent EUS-guided pancreatic cyst lavage with either 80% ethanol (control) or normal saline (alcohol-free group). Cysts in both groups were then infused with an admixture of paclitaxel and gemcitabine. Primary outcomes were the rates of complete ablation 12 months after the procedure, and rates of serious and minor adverse events within 30 days of the procedure. RESULTS: At 12 months, 67% of patients who underwent alcohol-free EUS-guided cyst chemoablation had complete ablation of cysts compared with 61% of patients in the control group. Serious adverse events occurred in 6% of patients in the control group vs none of the patients in the alcohol-free group. Minor adverse events occurred in 22% of patients in the control group and none of the patients in the alcohol-free group. The overall rate of complete ablation was 64%. CONCLUSIONS: In this prospective, randomized, controlled trial, we found that alcohol is not required for effective EUS-guided pancreatic cyst ablation, and when alcohol is removed from the ablation process, there is a significant reduction in associated adverse events. A multi-agent chemotherapeutic ablation admixture did not appear to significantly improve rates of complete ablation compared with the current standard of alcohol lavage followed by paclitaxel alone. ClinicalTrials.gov ID: NCT01475331.

Endoscopic Management of Large (≥2 cm) Non-pedunculated Colorectal Polyps: Impact of Polyp Morphology on Outcomes.

BACKGROUND AND AIMS: Referrals for endoscopic management of large non-pedunculated (NP) colorectal polyps have increased as new techniques have emerged. The outcomes for referred large NP polyps based on the polyp morphology were investigated METHODS: A retrospective review of patients referred for large (≥20 mm) NP polyp management from January 2010 through June 2014 was completed. Polyp morphology was classified as either a NP polyp with depression (M1) or NP polyp with no depression (M0). Differences in treatment, histology, adverse events, outcomes at follow-up including residual disease, and need for surgical treatment were determined by morphology for all NP polyps ≥20 mm in size. RESULTS: One-hundred and sixty-nine M1 and 136 M0 polyps ≥20 mm were removed endoscopically during the review period. Mean size was 31.9 ± 11.0 mm in M1, and 26.8 ± 9.5 mm in M0 group (p < 0.0001). En bloc resection was possible in 18.3 % of M1 and 30.9 % of M0 lesions (p = 0.011) with endoscopic submucosal dissection used in 13 and 2.2 % of polyps, respectively (p < 0.0001). Residual polyp was found in 26.5 % (27/102) of M1 and 13.6 % (12/88) of M0 patients at surveillance colonoscopy (p = 0.029). On multivariate analysis, piecemeal resection and M1 morphology showed significant association with residual polyp (OR 4.23, 95 % CI 1.23-14.59, p = 0.022, and OR 2.15, 95 % CI 1.004-4.62, p = 0.049, respectively). CONCLUSION: Effective endoscopic management of large NP colorectal polyps, especially polyps without depression (M0), can be accomplished in the great majority of patients. Polyp morphology, particularly the presence or absence of depression, is a useful tool which influenced treatment, histology, and outcomes.

Endoscopic Ultrasound-Guided Ablation of Pancreatic Mucinous Cysts.

Endoscopic ultrasound (EUS) has rapidly evolved from a diagnostic to a therapeutic tool with applications for various pancreaticobiliary diseases. As part of this evolution, EUS-guided chemoablation for neoplastic pancreatic cysts is developing as a minimally invasive treatment option for appropriately selected mucinous cysts, which can spare patients major resective surgery and may reduce progression to pancreatic cancer. Chemotherapeutic cyst ablation has demonstrated encouraging complete resolution rates, while an alcohol-free chemoablation protocol has demonstrated a significant decrease in adverse events without a compromise to complete ablation rates when compared with previous alcohol-based protocols. Most pancreatic cysts are small, low risk, and best managed by surveillance per accepted guidelines. Cysts with features suggestive of overt malignancy are best discussed by a multidisciplinary committee, and surgery is considered if appropriate. However, for patients in the middle ground with cysts that are structurally suitable for chemoablation, alcohol-free chemoablation has been shown to allow effective, safe, and durable results especially for those who are not ideal operative candidates. EUS-guided alcohol-free chemoablation is promising and continues to evolve; however, as a relatively novel treatment option it has areas of uncertainty that will require further investigation and development.

An intestinal occlusion device for prevention of small bowel distention during transgastric natural orifice transluminal endoscopic surgery.

BACKGROUND AND OBJECTIVES: Bowel distention from luminal gas insufflation reduces the peritoneal operative domain during natural orifice transluminal endoscopic surgery (NOTES) procedures, increases the risk for iatrogenic injury, and leads to postoperative patient discomfort. METHODS: A prototype duodenal occlusion device was placed in the duodenum before NOTES in 28 female pigs. The occlusion balloon was inflated and left in place during the procedure, and small bowel distension was subjectively graded. One animal had no balloon occlusion, and 4 animals had a noncompliant balloon placed. RESULTS: The balloon maintained its position and duodenal occlusion in 22 animals (79%) in which the bowel distention was rated as none (15), minor (4), moderate (3), or severe (0). The intestinal occlusion catheter failed in 6 animals (21%) because of balloon leak (5) or back-migration into the stomach (1), with distention rated as severe in 5 of these 6 cases. CONCLUSION: The intestinal occlusion catheter that maintains duodenal occlusion significantly improves the intraabdominal working domain with enhanced visualization of the viscera during the NOTES procedure while requiring minimal time and expense.

Intramural acellular porcine dermal matrix (APDM)-assisted gastrotomy closure for natural orifice transluminal endoscopic surgery (NOTES).

BACKGROUND: A highly reliable and safe means of gastric closure for natural orifice transluminal endoscopic surgery (NOTES) has yet to be developed. The authors have previously described the self-approximating transluminal access technique (STAT) as a means for gastrotomy closure in transgastric surgery. It has yet to be determined whether biologic mesh can be utilized in facilitating gastrotomy closure via STAT. The aim of this study was to determine the feasibility of implanting an acellular porcine dermal matrix (LifeCell) into the STAT tunnel and investigate whether it will become incorporated into the submucosal plane of the STAT tunnel. METHODS: Five pigs underwent transgastric left uterine horn resection utilizing STAT. For closure, the acellular porcine dermal matrix was implanted within the submucosal plane, occluding the seromuscular incision. The mucosal incision was then closed over the matrix with endoscopically placed clips. Necropsy was performed after a 3 week survival period. Histopathological evaluation of the tunnel and matrix was performed. RESULTS: The matrix was successfully implanted in all five animals. Average OR time was 151 ± 68 min. Average time to anchor and embed the matrix within the tunnel was 4 ± 1 and 9 ± 12 min, respectively. There was one duodenal perforation related to a balloon occlusion device. Postoperative course was unremarkable; the average weight gain at 3 weeks was 22 ± 5 lbs. On necropsy, one animal had some protrusion of the matrix at the serotomy, with adhesions to small bowel and liver. Histopathology revealed one clinically insignificant microabscess but otherwise demonstrated local inflammation and fibrovascular ingrowth into the matrix. CONCLUSIONS: The porcine dermal matrix can be successfully implanted within the gastric submucosal plane and evidence of incorporation into the gastric wall by 3 weeks was demonstrated.

Durability of the self-approximating translumenal access technique (STAT) for potential use in natural orifice translumenal surgery (NOTES).

BACKGROUND: The self-approximating translumenal access technique (STAT) has been shown to provide a safe and reliable means of abdominal access for natural orifice translumenal endoscopic surgery (NOTES). However, the feasibility of using STAT for translumenal organ resection is unknown. This study aimed to evaluate the technical performance of organ resection using STAT, the integrity of the STAT gastric tunnel after organ resection, and the postoperative morbidity of organ resection using STAT. METHODS: In this study, 14 domestic swine underwent transgastric organ resection (7 cholecystectomies, 7 uterine horn resections) followed by sequential removal of two different sizes of standardized specimens. Evaluation of operative injury to the tunnel and difficulty of specimen extraction was performed. After 2 weeks of observation, necropsy was performed for evaluation and documentation of gross findings. RESULTS: The mean operating room time (intubation recovery) was 4.1 h. A tunnel with a mean length of 12 cm and a mean width of 4 cm was created. The tunnel remained fully intact in 14 of 14 animals after organ resection, in 13 of 13 animals after balloon extraction, and in 12 of 14 animals after rigid specimen extraction (1 clinically significant tear occurred). Postoperatively, all the animals gained weight appropriately. Necropsy findings included adhesions (n = 4), bile leak (n = 2), minor lap-port abscess (n = 1), and ventral hernia (n = 1). CONCLUSIONS: Although this study was a limited, prospective, animal survival study without a control arm, it again indicates that STAT allows safe abdominal access, a reliable means of closure, and directed endoscope positioning. Although one significant mucosal tear did occur, this study suggests STAT will tolerate the mechanical forces of peroral transgastric procedures provided the organ resected is small to moderate in size (<8 × 3 cm).

Reliability of gastric access closure with the self-approximating transluminal access technique (STAT) for NOTES.

BACKGROUND: STAT, or the self-approximating transluminal access technique, has been previously described and involves the dissection of a submucosal tunnel for peritoneal or mediastinal access from the esophagus and stomach. The objective of this study was to assess the safety and reliability of gastric access and closure in a porcine experience using STAT for natural orifice transluminal endoscopic surgery (NOTES). METHODS: A review of the experience using STAT access tunnels for intraperitoneal access was performed in 39 female pigs at a university animal lab. All animals underwent a predetermined NOTES surgical procedure using a STAT transgastric access tunnel based on a specific protocol. Details of the procedure, complications, and clinical course were documented. Necropsy was performed at 2 weeks. The main outcome measurements were clinical or necropsy evidence of gastrostomy site leak or inadequate access site closure. RESULTS: STAT was successful in providing safe peritoneal access in all animals. The width of the tunnel ranged from 1.5 to 5.5 cm and the length was up to 27 cm. There was no evidence of gastrostomy site leak in any animals. One animal required a single laparoscopic suture to help with tunnel closure. CONCLUSION: STAT provides safe transgastric access and allows secure closure of the gastrotomy site.