Influence of storage on larval length and age determination of the forensically important blow fly Lucilia sericata (Diptera: Calliphoridae).

One of the main tasks in forensic entomology is the determination of the minimum post-mortem interval (PMImin) based on the age of the juvenile insects feeding and developing on the dead body. An important task is to store the evidence appropriately so that the evaluation and expert report can be used in court. However, existing recommendations can be contradictory or lacking scientific validation, e.g. by proposing various preservation liquids without knowing whether and to what extent the period of storage in such a liquid has an effect on the length of the preserved larvae. Storage time can be an issue since, due to technical and procedural circumstances, killed larvae may be stored for hours, days, weeks or even longer prior length measurement. A changed body length would have consequences for the entomological report, as the age of the larvae is usually derived from their length. This study investigates the effect of four differently concentrated ethanol solutions (70%, 80%, 90% and 96%) during a storage period of up to 196 days on the body length of stored larvae of the forensically important blow fly species L. sericata (Diptera: Calliphoridae). Larvae of different ages (24 h, 48 h and 72 h after hatching) were killed by immersion in hot, non-boiling water (≥80 °C) for at least 30 s. Their lengths were measured immediately. Subsequently samples were stored in ethanol of appropriate concentration at room temperature (approx. 22 °C). Further length measurements were made at 16 different storage intervals between 1 and 196 days. Many specimens showed a length decrease for most storage conditions and all larval ages. However, there was a tendency for 48 h- and 72 h-old larvae to increase in length after the first days of storage of up to 1.1 mm which may lead to an erroneous overestimation of the PMImin using this kind of specimens. All changes in length within each cohort over total time were in the range of +7% to -9.1%. Significant differences in length changes within the first days of storage were found mainly in larvae stored in 70%- and 80%-ethanol, but larvae stored in 90%- and 96%-ethanol showed first significant differences on day 56 at the earliest. Our results lead to the recommendation that the measurements of fly larvae samples should be taken immediately after killing and before storage to avoid any effects. Ethanol ≥90% should be used for storage.

Learning colorectal endoscopic submucosal dissection: a prospective learning curve study using a novel ex vivo simulator.

BACKGROUND: Endoscopic submucosal dissection (ESD) is increasingly being used in Asia as a minimally invasive therapy to eradicate large laterally spreading superficial tumors in the colon. To date, the learning curve and effectiveness of ex vivo simulators in colonic ESD training remain unclear. The aim of the study is to determine the learning curve of colonic ESD in an ex vivo simulator. METHODS: We conducted a prospective study of colon ESD in ex vivo porcine colons in a prototype simulator. Three endoscopists with prior experience in gastric ESD but with no experience in colonic ESD each performed 30 ESD resections on standardized lesions in the rectosigmoid and left colon of the porcine simulator. Procedure time, en bloc resection status, and perforation were recorded. RESULTS: All 90 lesions were resected using the ESD technique. The mean time of procedure was 49.6 min (standard deviation 29.6 min). The aggregate rate of perforation was 14.4% and the aggregate rate of non-en bloc resection was 5.6%. Using a composite quality score integrating complications and procedural time, it was found that there was a significant difference between two local polynomial regression lines when using a cut-point at the 9th procedure (p = 0.04), reflecting the point at which most of the learning curve is traversed. CONCLUSIONS: In this study, there were significant improvements realized in colonic ESD performance after 9 colon ESD procedures in ex vivo specimens. Although training will depend on endoscopist skill and expertise, we suggest at least 9 ex vivo procedures prior to moving to live animal or proctored training in colonic ESD.

Prospective, Randomized Ex Vivo Trial to Assess the Ideal Stapling Site for Endoscopic Fundoplication with Medigus Ultrasonic Surgical Endostapler.

Background and Aims. Endoscopic fundoplication is an emerging technique for the treatment of gastroesophageal reflux disease (GERD). The aim of this study is to determine the ideal position of the staples in relation to gastroesophageal junction (GEJ). Methods. Ten endoscopic fundoplication procedures were performed in each group using fresh ex vivo porcine stomachs: Group A: 2 staples each at 3 cm above the GEJ and 180° apart; Group B: 2 staples at 3 cm and 90° apart; Group C: 2 staples at 4 cm and 180° apart; Group D: 3 staples at 3 cm with 90° between each staple (180° total). After the procedure, the stomach was gradually filled with water. Gastric yield pressure (GYP) was determined by detection of reflux of the water in esophagus or by rupture of staples. Results. Mean increase of GYPs (±SD) after the procedure was as follows: Group A: 16.9 ± 8.7; Group B: 8.1 ± 7.9; Group C: 12.2 ± 9.4; Group D: 22.7 ± 13.3. GYP in Group A and Group D was higher than Group B (p = 0.03 and p = 0.01, resp.). Conclusions. We recommend the placement of 3 staples at 3 cm distance from the GEJ, which resulted in the highest increase of GYP.

Pre-clinical Training for New Notes Procedures: From Ex-vivo Models to Virtual Reality Simulators.

Natural orifice transluminal endoscopic surgery (NOTES) is a newer field of endoscopic surgery that allows for scarless treatment of pathologic entities, using novel transluminal approaches. There has been a shift of focus from a clinical and research standpoint from the development and dissemination of "first-generation" NOTES procedures to "new NOTES" procedures that traverse the mucosa of luminal structures, yet do not stray far into the peritoneal cavity. It has been a challenge to find appropriate and effective ways to train gastroenterologists and surgeons in these novel approaches. We review the importance of simulation in training and discuss available simulation options.

One hundred and one over-the-scope-clip applications for severe gastrointestinal bleeding, leaks and fistulas.

AIM: To investigate the efficacy and clinical outcome of patients treated with an over-the-scope-clip (OTSC) system for severe gastrointestinal hemorrhage, perforations and fistulas. METHODS: From 02-2009 to 10-2012, 84 patients were treated with 101 OTSC clips. 41 patients (48.8%) presented with severe upper-gastrointestinal (GI) bleeding, 3 (3.6%) patients with lower-GI bleeding, 7 patients (8.3%) underwent perforation closure, 18 patients (21.4%) had prevention of secondary perforation, 12 patients (14.3%) had control of secondary bleeding after endoscopic mucosal resection or endoscopic submucosal dissection (ESD) and 3 patients (3.6%) had an intervention on a chronic fistula. RESULTS: In 78/84 patients (92.8%), primary treatment with the OTSC was technically successful. Clinical primary success was achieved in 75/84 patients (89.28%). The overall mortality in the study patients was 11/84 (13.1%) and was seen in patients with life-threatening upper GI hemorrhage. There was no mortality in any other treatment group. In detail OTSC application lead to a clinical success in 35/41 (85.36%) patients with upper GI bleeding and in 3/3 patients with lower GI bleeding. Technical success of perforation closure was 100% while clinical success was seen in 4/7 cases (57.14%) due to attendant circumstances unrelated to the OTSC. Technical and clinic success was achieved in 18/18 (100%) patients for the prevention of bleeding or perforation after endoscopic mucosal resection and ESD and in 3/3 cases of fistula closure. Two application-related complications were seen (2%). CONCLUSION: This largest single center experience published so far confirms the value of the OTSC for GI emergencies and complications. Further clinical experience will help to identify optimal indications for its targeted and prophylactic use.

Natural orifice translumenal endoscopic surgery (NOTES): emerging trends and specifications for a virtual simulator.

INTRODUCTION AND STUDY AIM: A virtual translumenal endoscopic surgical trainer (VTEST) is being developed to accelerate the development of natural orifice translumenal endoscopic surgery (NOTES) procedures and devices in a safe and risk-free environment. For a rapidly developing field such as NOTES, a needs analysis must be conducted regularly to discover emerging research trends and areas of potential high impact for a virtual simulator. This paper presents a survey-based study which follows a similar study conducted by this group in 2011 (Sankaranarayanan et al. in Surg Endosc 27:1607-1616, 2013). METHODS: A 32-point questionnaire was distributed at the 2012 Natural Orifice Surgery Consortium for Assessment and Research annual meeting. These data were subsequently augmented by an identical online survey, targeted at the members of the American Society for Gastrointestinal Endoscopy and the Society of American Gastrointestinal and Endoscopic Surgeons, and analyzed. RESULTS: Twenty-eight NOTES experts participated in the 2012 study. Cholecystectomy (CE) procedure remained the most commonly performed NOTES technique, with 18 positive responses (64%). In contrast to 2011, the popularity of the NOTES appendectomy (AE) was significantly lower, with only 2 (7%) instances (CE vs. AE, p < 0.001), while the number of peroral endoscopic myotomy (POEM, PE) cases had increased significantly, with 11 (39%) positive responses, respectively (PE vs. AE, p = 0.013). Strong preference toward hybrid rather than pure NOTES techniques (82 vs. 11%, p < 0.001) was also expressed. Other responses were similar to those in the 2011 study, with the VTEST™ utility in developing and testing new techniques and instruments ranked particularly high. CONCLUSION: Based on the results of this study, a decision was made to focus exclusively on the transvaginal hybrid NOTES cholecystectomy procedure, including both rigid and flexible scope techniques. The importance of developing a virtual NOTES simulator was reaffirmed, with POEM identified as a promising candidate for future simulator development.

Prospective randomized comparison of gastrotomy closure associating tunnel access and over-the-scope clip (OTSC) with two other methods in an experimental ex vivo setting.

BACKGROUND: Safe transgastric natural orifice transluminal endoscopic surgery (NOTES) procedures require a reliable closure of the gastrotomy. Recently a novel peritoneal access method via a submucosal tunnel has been described with encouraging preliminary results. AIM: The aim is to compare a submucosal tunnel access plus over-the-scope clip (OTSC) system for closure with two other closure modalities. PATIENTS AND METHODS: This is a prospective ex vivo study conducted on 42 porcine stomach models equally randomized into three groups in an academic medical center. The procedures performed in each group included: (1) Tunnel (6 cm) + endoclips; (2) Knife + balloon dilation access + OTSC; and (3) Tunnel + OTSC. A pressurized air-leak test was performed to evaluate the strength of the closure. Stomach volumes, procedure times, number of clips, and incision sizes were also registered. RESULTS: The mean air-leak pressure was statistically higher in Group 3 than in Groups 1 and 2-95.2 ±â€Š19.3 mmHg versus 72.5 ±â€Š35.2 and 79.0 ±â€Š24.5 mmHg (P < 0.05). The gastrotomy creation times for Groups 1, 2, and 3 were 28.0 ±â€Š10.1, 4.3 ±â€Š1.4, and 20.1 ±â€Š10.6 minutes, respectively, with significantly lower time in Group 2 (P < 0.001). The closure times were 16.1 ±â€Š6.1, 6.5 ±â€Š1.2, and 5.3 ±â€Š3.0 minutes, respectively, and significantly longer in the endoclip group (P < 0.001). There were no differences in the volumes and the incision sizes among the three groups. CONCLUSION: The combination of a submucosal tunnel access and OTSC offers a stronger closure than the other methods studied.

Erratum: Prospective randomized comparison of gastrotomy closure associating tunnel access and over-the-scope clip (OTSC) with two other methods in an experimental ex vivo setting.

[This corrects the article DOI: 10.1055/s-0034-1390794.].

Characterization of force and torque interactions during a simulated transgastric appendectomy procedure.

We have developed an instrumented endoscope grip handle equipped with a six-axis load cell and measured forces and torques during a simulated transgastric natural orifice translumenal endoscopic surgery appendectomy procedure performed in an EASIE-R ex vivo simulator. The data were collected from ten participating surgeons of varying degrees of expertise which was analyzed to compute a set of six force and torque parameters for each coordinate axis for each of the nine tasks of the appendectomy procedure. The mean push/pull force was found to be 3.64 N (σ = 3.54 N) in the push direction and the mean torque was 3.3 N · mm (σ = 38.6 N · mm) in the counterclockwise direction about the push/pull axis. Most interestingly, the force and torque data about the nondominant x and z axes showed a statistically significant difference (p < 0.05) between the expert and novice groups for five of the nine tasks. These data may be useful in developing surgical platforms especially new haptic devices and simulation systems for emerging natural orifice procedures.

Assessment of the length of myotomy in peroral endoscopic pyloromyotomy (G-POEM) using a submucosal tunnel technique (video).

BACKGROUND: Peroral endoscopic pyloromyotomy is a novel technique that has recently been described in the literature. There is little data to guide the length of myotomy created. The aim of study was to evaluate the proper incision length of the muscular layer during peroral endoscopic pyloromyotomy using a submucosal tunnel technique. METHODS: The study was designed as a prospective ex vivo study. Fresh ex vivo porcine stomachs from animals weighing 80-100 kg and porcine stomachs from animals weighing 15-25 kg were used for pyloromyotomy. Four different myotomy lengths (1, 2, 3, and 4) were compared in the large animal series and three different myotomy lengths (1, 2, and 3) were compared in the small series. A total of 23 cases of the submucosal tunnel technique were performed by two endoscopists using 12 large stomachs and 11 small stomachs. RESULTS: The mean overall procedure time (± SD) of pyloromyotomy was 65.7 (± 14.3) min. In the large stomach series, the mean pyloric diameter (± SD) and change from baseline (as percentage) following a 1, 2, 3, and 4 pyloromyotomy were 13.3 ± 9.5 mm (7.1 %), 20.7 ± 11.7 mm (10.6 %), 31.1 ± 15.0 mm (15.2 %), and 33.0 ± 15.0 mm (16.0 %), respectively. In the small stomach series, the changes of mean pyloric diameter following a 1, 2, and 3 cm pyloromyotomy were 12.2 ± 5.6 mm (7.5 %), 23.1 ± 7.6 mm (13.1 %), and 28.0 ± 10.4 mm (15.5 %), respectively. CONCLUSIONS: A 3 cm pyloromyotomy for a large animal series and 2 cm for the small animal series appeared to be most appropriate for enlargement of the pylorus.

Kinematic Measures for Evaluating Surgical Skills in Natural Orifice Translumenal Endoscopic Surgery (NOTES).

Natural Orifice Translumenal Endoscopic Surgery is an emerging procedure that requires training and adoption to be successful. Currently no objective performance metrics exist for evaluating skills for NOTES. In this work, we have improved upon our previous study on objective performance metrics using kinematic measures by introducing two new measures, the flex and the roll and recruiting more subjects to increase the statistical power. The measures were evaluated in a transgastric NOTES appendectomy procedure performed with ex-vivo organs using the EASIE-RTM trainer box. Four motion tracking sensors attached to an endoscope were used to measure the scope position and orientation to compute the kinematic measures. Results from our study showed that completion time, economy of motion, jerk and roll of the scope are valid kinematic measures to differentiate between expert and novice NOTES surgeons.

Validation of a novel, tissue-based simulator for robot-assisted radical prostatectomy.

PURPOSE: To create a tissue-based simulator that allows practice of key steps of robot-assisted radical prostatectomy (RARP) in a sequential fashion. MATERIALS AND METHODS: A model was created from female porcine genitourinary tract tissue to represent the male pelvic genitourinary anatomy. The following steps of RARP were simulated: dorsal venous complex ligation, division of bladder neck, seminal vesicle dissection, prostatic pedicle ligation with nerve sparing, urethral division, bladder neck reconstruction, and vesicourethral anastomosis. Ten novices and 10 experts performed RARP on the model. Face validity was calculated by ratings of realism. Content validity was calculated by experts' rating of usefulness of the model as a training tool. Construct validity was calculated by comparison of time to complete the simulator and rating of performance on the objective structured assessment of technical skill (OSATS) questionnaire, between novices and experts. RESULTS: The model was determined to have good face and content validity with an average score of 3.7/5 and 4.8/5, respectively. The mean time for completion of the simulator was 121.5 minutes for the novice and 62 minutes for the expert group (P<0.001), and the mean overall OSATS performance ratings were 4.6/5 for experts and 2.6/5 for novices (P<0.001), yielding good construct validity. CONCLUSIONS: We created and validated a realistic, tissue-based simulator to allow for training of key surgical steps of RARP in a sequential fashion. Ultimately, this simulator could be incorporated into urology training, credentialing, and facilitate surgeon transitioning from open prostatectomy to RARP.

Effectiveness of circumferential endoscopic mucosal resection with a novel tissue-anchoring device.

AIM: To evaluate the efficacy of circumferential endoscopic mucosal resection (EMR) with a tissue-anchoring device in comparison to forceps precut EMR and conventional endoscopic submucosal dissection (ESD). METHODS: The study was designed as a prospective, randomized, ex vivo study. Fresh ex vivo specimens were harvested from adult white Yorkshire pigs weighing 30-50 kg. Seventy-five standardized, artificial lesions measuring 3 cm × 3 cm were created by methylene blue tattoo at the greater curvature in fresh ex vivo stomachs using the EASIE-R simulator platform (Endosim LLC, Berlin, MA, United States). The three advanced endoscopists performed the three resection techniques such as circumferential EMR using the tissue-anchoring device (TA-EMR), forceps precut EMR (FP-EMR), and endoscopic submucosal dissection. The endoscopists and the type of cutting methods were determined randomly by grouped randomized selection. The resection bed was grossly inspected to determine whether the lesion was resected "en-bloc" (defined as no remaining mucosal tattoo remaining on specimen). The resection bed was also probed for evidence of perforation. The procedural time of circumferential resection, submucosal dissection, and injection frequency were recorded by an independent observer. RESULTS: All 75 created lesions were successfully resected by three advanced endoscopists using the three techniques. The mean ± SD size of resected specimens (long axis) were 39.5 ± 5.6 mm, 36.5 ± 7.3 mm, and 44.6 ± 5.6 mm for TA-EMR, FP-EMR, and ESD respectively. The overall mean dissection time of both the TA-EMR and FP-EMR was significant shorter than ESD (TA-EMR: 5.1 ± 3.3 min, FP-EMR: 3.5 ± 2.0 min vs ESD: 15.8 ± 9.5 min, P < 0.001, P < 0.001). The overall mean total procedure time of both the tissue-anchoring and forceps circumferential EMR was significantly shorter than ESD (TA-EMR: 17.5 ± 6.0 min, FP-EMR: 16.6 ± 6.6 min vs ESD: 28.6 ± 13.9 min, P < 0.001, P < 0.001). The en-bloc resection rate of ESD was 100% (25/25) and the en-bloc resection rate of the TA-EMR (84.0%, 21/25) was higher than for the FP-EMR (60.0%, 15/25), yet not statistically significant (P = 0.18). The perforation rate of each technique was 8.0% (2/25). CONCLUSION: TA-EMR appears to be quicker than ESD, and there was a trend towards improved en bloc resection rate with the TA-EMR when compared to the FP-EMR.

Prospective, randomized comparison of a prototype endoscope with deflecting working channels versus a conventional double-channel endoscope for rectal endoscopic submucosal dissection in an established experimental simulation model (with video).

BACKGROUND: A prototype endoscope was designed to improve visualization and dissection of tissue with the use of 2 working channels with different deflections. OBJECTIVE: To evaluate the efficacy and operability of a prototype endoscope in comparison with a conventional double-channel endoscope for rectal endoscopic submucosal dissection (ESD). DESIGN: Randomized, prospective, controlled, ex vivo study. SETTING: Academic medical center. METHODS: A total of 80 standardized artificial lesions measuring 3 × 3 cm were created approximately 5 cm from the anal verge in fresh ex vivo porcine colorectal specimens. Two endoscopists each completed 20 cases with the prototype endoscope and 20 cases with the conventional endoscope. MAIN OUTCOME MEASUREMENTS: An independent observer recorded procedure time, specimen size, en bloc resection, and perforation rate. RESULTS: For the ESD novice, the mean submucosal dissection time (10.5 ± 3.8 vs 14.9 ± 7.3 minutes; P = .024) and total procedure time (18.1 ± 5.2 vs 23.6 ± 8.2 minutes; P = .015) were significantly shorter in the prototype group in comparison with the conventional group. For the ESD expert, there was no significant difference between the mean circumferential resection, submucosal dissection, and total procedure time (prototype group 14.2 ± 6.0 minutes, conventional group 14.2 ± 8.8 minutes; P = .992). The overall perforation and en bloc resection rates were not significantly different between groups. LIMITATIONS: Ex vivo study. CONCLUSION: In this ex vivo prospective comparison study, there was a technical advantage for the ESD novice with the prototype endoscope that resulted in a shorter procedure time, which was not observed for cases performed by the ESD expert.

Objective performance measures using motion sensors on an endoscopic tool for evaluating skills in natural orifice translumenal endoscopic surgery (NOTES).

Natural orifice translumenal endoscopic surgery is an emerging procedure. High fidelity virtual reality-based simulators allow development of new surgical procedures and tools and train medical personnel without risk to human patients. As part of a project funded by the National Institutes of Health, we are developing a Virtual Transluminal Endoscopic Surgery Trainer (VTEST TM) for this purpose. In this work, objective performance measures derived from motion tracking sensors attached to an endoscope was tested for the transgastric NOTES appendectomy procedure performed with ex-vivo pig organs using the EASIE-R(TM) trainer box. Results from our study shows that both completion time and economy of motion parameters were able to differentiate between expert and novice NOTES surgeons with p value of 0.039 and 0.02 respectively. Jerk computed on sensor 2 data also showed significant results (p = 0.02). We plan to incorporate these objective performance measures in VTEST(TM).

The learning curve for endoscopic submucosal dissection in an established experimental setting.

INTRODUCTION: Endoscopic submucosal dissection (ESD) has become a standard therapy for early gastric neoplasia, particularly in Asian countries. From a safety and efficacy standpoint, simulation training may empower the endoscopist to be able to learn the basic tenets of ESD in a safe, controlled and supervised setting before attempting first in humans. METHODS AND PROCEDURES: This study was designed as a prospective ex vivo study. Ex vivo porcine organs were utilized in the EASIE-R endoscopic simulator. A total of 150 artificial lesions, each 2 × 2 cm in size, were created in fresh ex vivo porcine stomachs at six different anatomical sites (fundus anterior and posterior, body anterior and posterior, antrum anterior and posterior). Three examiners (2 beginners, 1 expert) participated in this study. All parameters (procedure time, specimen size, en-bloc resection status, perforation) were recorded by an independent observer for each procedure. RESULTS: All 150 lesions were successfully resected using the ESD technique by the three endoscopists. After 30 ESD cases, the two novices performed ESD with a 100% en-bloc resection rate and without perforation. For the procedures performed by the novices, the total procedure time and perforation rate in the last 30 cases were significantly lower than during the first 30 cases (p < 0.05). CONCLUSIONS: Our study suggests that performing 30 ESD resections in an ex vivo simulator leads to a significant improvement in safety and efficiency of performing the ESD technique.

Needs analysis for developing a virtual-reality NOTES simulator.

UNLABELLED: INTRODUCTION AND STUDY AIM: Natural orifice translumenal endoscopic surgery (NOTES) is an emerging surgical technique that requires a cautious adoption approach to ensure patient safety. High-fidelity virtual-reality-based simulators allow development of new surgical procedures and tools and train medical personnel without risk to human patients. As part of a project funded by the National Institutes of Health, we are developing the virtual transluminal endoscopic surgery trainer (VTEST) for this purpose. The objective of this study is to conduct a structured needs analysis to identify the design parameters for such a virtual-reality-based simulator for NOTES. METHODS: A 30-point questionnaire was distributed at the 2011 National Orifice Surgery Consortium for Assessment and Research meeting to obtain responses from experts. Ordinal logistic regression and the Wilcoxon rank-sum test were used for analysis. RESULTS: A total of 22 NOTES experts participated in the study. Cholecystectomy (CE, 68 %) followed by appendectomy (AE, 63 %) (CE vs AE, p = 0.0521) was selected as the first choice for simulation. Flexible (FL, 47 %) and hybrid (HY, 47 %) approaches were equally favorable compared with rigid (RI, 6 %) with p < 0.001 for both FL versus RI and HY versus RI. The transvaginal approach was preferred 3 to 1 to the transgastric. Most participants preferred two-channel (2C) scopes (65 %) compared with single (1C) or three (3C) or more channels with p < 0.001 for both 2C versus 1C and 2C versus 3C. The importance of force feedback and the utility of a virtual NOTES simulator in training and testing new tools for NOTES were rated very high by the participants. CONCLUSION: Our study reinforces the importance of developing a virtual NOTES simulator and clearly presents expert preferences. The results of this analysis will direct our initial development of the VTEST platform.

Opioid-free single-incision laparoscopic (SIL) cholecystectomy using bilateral TAP blocks.

A 30 year old woman who was 8 weeks postpartum with a history of cholelithiasis and gallstone pancreatitis, and who was status-post endoscopic retrograde cholangiopancreatography (ERCP) with sphincterotomy, was treated with a single-incision laparoscopic (SIL) cholecystectomy. A transversus abdominis plane block (TAP) was performed after induction of anesthesia. The patient required no intraoperative or postoperative opioids.

Hemodynamic efficacy of the over-the-scope clip in an established porcine cadaveric model for spurting bleeding.

BACKGROUND: Clip application has been proven to be effective for endoscopic hemostasis. There are limited bench data on the efficacy of the over-the-scope clip (OTSC) for the treatment of spurting GI hemorrhage. We evaluated the hemodynamic efficacy of the OTSC in an established bleeding model. OBJECTIVE: To evaluate the hemodynamic efficacy of the OTSC in an established bleeding model. DESIGN: Prospective experimental trial with historical comparison. SETTING: We tested the OTSC prospectively in a validated bleeding model by using the compact Erlangen Active Simulator for Interventional Endoscopy equipped with an upper GI organ package. The artificial blood circulation system of the simulator was connected to an arterial pressure transducer. Two investigators with different endoscopic experience (4000 and 10,000 endoscopies performed) participated. Each investigator treated 16 bleeding sites in the simulator with the OTSC by using only suction (n = 8) and a novel retraction device to grasp tissue (n = 8). Systemic pressures were recorded 1 minute before, during, and 1 minute after clip application to objectify the effects of clipping on the vessel diameter. MAIN OUTCOME MEASUREMENTS: Mean and maximum reduction in vessel diameter. RESULTS: The application of the OTSC on the bleeding vessel led to a significant increase in systemic pressure (P < .001) and decreased vessel diameter (P < .001) independent of the endoscopic experience of the investigator. There was no difference in the decrease in vessel diameter based on the application technique (suction vs suction plus grasping). A historical comparison with our former trials demonstrated that the OTSC decreased the vessel diameter significantly more than other traditional endoclips. LIMITATIONS: Small sample size. CONCLUSIONS: We could demonstrate the efficacy of the OTSC with increased hemodynamic efficiency compared with other endoscopic clip devices tested previously.

Prospective, randomized comparison of 3 different hemoclips for the treatment of acute upper GI hemorrhage in an established experimental setting.

BACKGROUND: Recently, endoscopic clip application devices have undergone redesign and improvements to optimize their clinical use and effectiveness. Initially designed for the treatment of bleeding nonvariceal lesions, these devices are also increasingly used for the closure of perforations, fistulas, and anastomotic leaks. Several clinical studies, both randomized and nonrandomized, have used endoscopic hemoclips for hemostasis. However, no comparative studies have yet been reported in the literature comparing the latest endoscopic clip devices for usability and effectiveness for hemostasis of acute upper GI hemorrhage. OBJECTIVE: We aimed to compare the usability and efficacy of 3 different types of endoscopic clip application devices in an established experimental setting by using a porcine ex-vivo simulator of upper GI hemorrhage. DESIGN: Randomized, controlled, ex-vivo study. SETTING: Academic medical center. METHODS: Spurting vessels were created within ex-vivo porcine stomachs as published in prior studies. The vessels were attached to a pressure transducer to record the pressure of the circulating blood replacement. Before the initiation of bleeding, each vessel was randomized to 1 of 3 endoscopic clipping devices: 2 different commonly used hemoclips deployed through the working channel and 1 novel clip deployed via an over-the-scope applications device. Two investigators treated 45 bleeding sites (15 bleeding sites for each device at various randomized locations in the stomach: fundus, body, and antrum). MAIN OUTCOME MEASUREMENTS: Usability was measured via the endpoints of procedure time and quantity of clips required to achieve hemostasis. Efficacy was measured via the endpoint of pressure increase (Δp) from baseline to after treatment. RESULTS: All of the 45 hemostasis treatments were carried out successfully. The mean procedure times were significantly different among the hemoclips, with the clip deployed in an over-the-scope fashion requiring significantly less time to attain hemostasis compared with the other 2 clips. For number of clips needed to attain hemostasis, the clip deployed in an over-the-scope fashion was significantly superior to the others. There were also significant differences among the changes in pressure (Δp ± SD) among the different hemoclips tested. LIMITATIONS: Ex-vivo study. CONCLUSIONS: In this prospective, randomized ex-vivo study, we observed significant differences in the usability (time to achieve hemostasis and number of clips required) and the efficacy (change in pressure achieved by the hemoclips) among the 3 clips. The clip applied in the over-the-scope fashion was superior to the other 2 tested clips with regard to time to achieve hemostasis and number of clips required.