How to say "I don't know": development and evaluation of workshops for medical students and surgical residents on communicating uncertainty using the ADAPT framework.

Purpose: Uncertainty, or the conscious awareness of having doubts, is pervasive in medicine, from differential diagnoses and the sensitivity of diagnostic tests, to the absence of a single known recovery path. While openness about uncertainty is necessary for shared decision-making and is a pillar of patient-centered care, it is a challenge to do so while preserving patient confidence. The authors' aim was to develop, pilot, and evaluate an uncertainty communication curriculum to prepare medical students and residents to confidently navigate such conversations. Methods: The authors developed ADAPT, a mnemonic framework to improve student comprehension and recall of the important steps in uncertainty disclosure: assess the patient's knowledge, disclose uncertainty directly, acknowledge patient emotions, plan next steps, and temper expectations. Using this framework, the authors developed, piloted, and evaluated an uncertainty communications course as part of an ongoing communication curriculum for second year medical students in 2020 and with surgical residents in 2021. Results: Learner confidence in uncertainty communication skills significantly increased post-class. Resident confidence in disclosing uncertainty was significantly correlated with observer ratings of their related communication skills during simulation. Students expressed positive experiences of the class, noting particular appreciation for the outline of steps included in the ADAPT framework, and the ability to observe a demonstration prior to practice. Conclusions: The ADAPT communication curriculum was effective at increasing learner confidence and performance in communicating uncertainty. More rigorous evaluation of the ADAPT protocol will be important in confirming its generalizability. Supplementary Information: The online version contains supplementary material available at 10.1007/s44186-022-00075-4.

Virtual Communication Across Differences: Development of a Workshop on Managing Patient Bias.

PROBLEM: Despite the prevalence and detrimental effects of racial discrimination in American society and its health care systems, few medical schools have designed and implemented curricula to prepare medical students to respond to patient bias and racism. APPROACH: During the summer of 2020, a virtual communication class was designed that focused on training medical students in how to respond to patient bias and racism. Following brief didactics at the start of the session, students practiced scenarios with actors in small groups and received direct feedback from faculty. For each scenario, students were instructed to briefly gather a patient's history and schedule an appointment with the attending whose name triggered the patient to request an "American" provider. In one scenario, the patient's request was motivated by untreated hearing loss and difficulty understanding accents. In another, it was motivated by racist views toward foreign physicians. Students were to use motivational interviewing (MI) to uncover the reasoning behind the request and respond appropriately. Students assessed their presession and postsession confidence on 5 learning objectives that reflect successful communication modeled after MI techniques. OUTCOMES: Following the session, student skills confidence increased in exploring intentions and beliefs ( P = .026), navigating a conversation with a patient exhibiting bias ( P = .019) and using nonverbal skills to demonstrate empathy ( P = .031). Several students noted that this was their first exposure to the topic in a medical school course and first opportunity to practice these skills under supervision. NEXT STEPS: The experience designing and implementing this module preparing students in responding to patient bias and racism suggests that such an effort is feasible, affordable, and effective. With the clear need for such a program and positive impact on student confidence navigating these discussions, including such training in medical school programs appears feasible and is strongly encouraged.

Building Rapport and Earning the Surgical Patient's Trust in the Era of Social Distancing: Teaching Patient-Centered Communication During Video Conference Encounters to Medical Students.

BACKGROUND: Effective physician communication improves care, and many medical schools and residency programs have adopted communication focused curricula. The COVID-19 pandemic has shifted the doctor-patient communication paradigm with the rapid adoption of video-based medical appointments by the majority of the medical community. The pandemic has also necessitated a sweeping move to online learning, including teaching and facilitating the practice of communication skills remotely. We aimed to identify effective techniques for surgeons to build relationships during a video consult, and to design and pilot a class that increased student skill in communicating during a video consult. METHODS: Fourth-year medical students matched into a surgical internship attended a 2-hour class virtually. The class provided suggestions for building rapport and earning trust with patients and families by video, role play sessions with a simulated patient, and group debriefing and feedback. A group debriefing generated lessons learned and best practices for telemedicine communication in surgery. RESULTS: Students felt the class introduced new skills and reinforced current ones; most reported higher self-confidence in target communication skills following the module. Students were particularly appreciative of opportunity for direct observation of skills and immediate faculty feedback, noting that the intimate setting was unique and valuable. Several elements of virtual communications required increased focus to communicate empathy and concern. Proper lighting and positioning relative to the camera were particularly important and body movement required "narration" to minimize misinterpretation. A patient's distress was more difficult to interpret; asking direct questions was recommended to understand the patient's emotional state. CONCLUSIONS: There is a need to teach video-conference communication skills to enable surgical teams to build rapport in this distinct form of consultation. Our training plan appears effective at engaging learners and improving skills and confidence, and identifies areas of focus when teaching virtual communication skills.

Structured simulation improves learning of the Fundamental Use of Surgical Energy™ curriculum: a multicenter randomized controlled trial.

BACKGROUND: Energy devices can result in devastating complications to patients. Yet, they remain poorly understood by trainees and surgeons. A single-institution pilot study suggested that structured simulation improves knowledge of the safe use of electrosurgery (ES) among trainees (Madani et al. in Surg Endosc 28(10):2772-2782, 2014). The purpose of this study was to estimate the extent to which the addition of this structured bench-top simulation improves ES knowledge across multiple surgical training programs. METHODS: Trainees from 11 residency programs in Canada, the USA and UK participated in a 1-h didactic ES course, based on SAGES' Fundamental Use of Surgical Energy™ (FUSE) curriculum. They were then randomized to one of two groups: an unstructured hands-on session where trainees used ES devices (control group) or a goal-directed hands-on training session (Sim group). Pre- and post-curriculum (immediately and 3 months after) knowledge of the safe use of ES was assessed using separate examinations. Data are expressed as mean (SD) and N (%), *p < 0.05. RESULTS: A total of 289 (145 control; 144 Sim) trainees participated, with 186 (96 control; 90 Sim) completing the 3-month assessment. Baseline characteristics were similar between the two groups. Total score on the examination improved from 46% (10) to 84% (10)* for the entire cohort, with higher post-curriculum scores in the Sim group compared with controls [86% (9) vs. 83% (10)*]. All scores declined after 3 months, but remained higher in the Sim group [72% (18) vs. 64% (15)*]. Independent predictors of 3-month score included pre-curriculum score and participation in a goal-directed simulation. CONCLUSIONS: This multi-institutional study confirms that a 2-h curriculum based on the FUSE program improves surgical trainees' knowledge in the safe use of ES devices across training programs with various geographic locations and resident volumes. The addition of a structured interactive bench-top simulation component further improved learning.

SAGES research agenda in gastrointestinal and endoscopic surgery: updated results of a Delphi study.

BACKGROUND: Research in gastrointestinal and endoscopic surgery has witnessed unprecedented growth since the introduction of minimally invasive techniques in surgery. Coordination and focus of research efforts could further advance this rapidly expanding field. The objective of this study was to update the SAGES research agenda for gastrointestinal and endoscopic surgery. METHODS: A modified Delphi methodology was used to create the research agenda. Using an iterative, anonymous web-based survey, the general membership and leadership of SAGES were asked for input over three rounds. Initially submitted research questions were reviewed and consolidated by an expert panel and redistributed to the membership for priority ranking using a 5-point Likert scale of importance. The top 40 research questions of this round were then redistributed to and re-rated by members, and a final ranking was established. Comparisons were made between membership and leadership responses. RESULTS: 283 initially submitted research questions were condensed into 89 distinct questions, which were rated by 388 respondents to determine the top 40 questions. 460 respondents established the final ranking of these 40 most important research questions. Topics represented included training and technique, gastrointestinal, hernia, GERD, bariatric surgery, and endoscopy. The top question was, "How do we best train, assess, and maintain proficiency of surgeons and surgical trainees in flexible endoscopy, laparoscopy, and open surgery?" 28% of responders were leadership and the rest general members with the majority of ratings (73%) being similar between the groups. While SAGES leadership rated the majority of questions (89%) lower, they rated nonclinical questions higher compared with general membership. CONCLUSIONS: An updated research agenda for gastrointestinal and endoscopic surgery was developed using a systematic methodology. This agenda may assist investigators and funding organizations to concentrate their efforts in the highest research priority areas and editors and reviewers in assessing the merit and relevance of scientific work.

Whole-genome resequencing of two elite sires for the detection of haplotypes under selection in dairy cattle.

Using a combination of whole-genome resequencing and high-density genotyping arrays, genome-wide haplotypes were reconstructed for two of the most important bulls in the history of the dairy cattle industry, Pawnee Farm Arlinda Chief ("Chief") and his son Walkway Chief Mark ("Mark"), each accounting for ∼7% of all current genomes. We aligned 20.5 Gbp (∼7.3× coverage) and 37.9 Gbp (∼13.5× coverage) of the Chief and Mark genomic sequences, respectively. More than 1.3 million high-quality SNPs were detected in Chief and Mark sequences. The genome-wide haplotypes inherited by Mark from Chief were reconstructed using ∼1 million informative SNPs. Comparison of a set of 15,826 SNPs that overlapped in the sequence-based and BovineSNP50 SNPs showed the accuracy of the sequence-based haplotype reconstruction to be as high as 97%. By using the BovineSNP50 genotypes, the frequencies of Chief alleles on his two haplotypes then were determined in 1,149 of his descendants, and the distribution was compared with the frequencies that would be expected assuming no selection. We identified 49 chromosomal segments in which Chief alleles showed strong evidence of selection. Candidate polymorphisms for traits that have been under selection in the dairy cattle population then were identified by referencing Chief's DNA sequence within these selected chromosome blocks. Eleven candidate genes were identified with functions related to milk-production, fertility, and disease-resistance traits. These data demonstrate that haplotype reconstruction of an ancestral proband by whole-genome resequencing in combination with high-density SNP genotyping of descendants can be used for rapid, genome-wide identification of the ancestor's alleles that have been subjected to artificial selection.

Characterization of bionanocomposite scaffolds comprised of mercaptoethylamine-functionalized gold nanoparticles crosslinked to acellular porcine tissue.

Bionanocomposite scaffolds comprised of nanomaterials and the extracellular matrix (ECM) of porcine diaphragm tissue capitalizes on the benefits of utilizing a natural ECM material, while also potentially enhancing physicomechanical properties and biocompatibility through nanomaterials. Gold nanoparticle (AuNP) bionanocomposite scaffolds were subjected to a number of characterization techniques to determine whether the fabrication process negatively impacted the properties of the porcine diaphragm tissue and whether the AuNP improved the properties of the tissue. Tensile testing and differential scanning calorimetry demonstrated that the bionanocomposite possessed improved tensile strength and thermal stability relative to natural tissue. The collagenase assay and Fourier transform infrared spectroscopy additionally confirmed that denaturation of the collagen of the ECM did not occur. The novel bionanocomposite scaffold possessed properties similar to commercially available scaffolds and will be further developed for soft tissue applications such as hernia repair through in vivo studies in an animal model.

Assessment of decellularized porcine diaphragm conjugated with gold nanomaterials as a tissue scaffold for wound healing.

One million Americans suffer from chronic wounds every year with diabetics and older populations representing the majority. Mechanisms that may be responsible for the reduced healing response in these patients include reduction in growth factors or vascularization and an increase in free radical levels. The focus of this study was to develop a biocompatible gold/porcine diaphragm scaffold capable of sustaining fibroblast attachment and proliferation which was measured using viability and dsDNA assays. The free radical scavenging properties, as measured by ROS assays, were also investigated as a mechanism for improving the wound environment. Results indicated 69-89% viability for gold nanoparticle (AuNP) scaffolds and 51-74% for gold nanorod (AuNR) scaffolds as compared to 100% for decellularized scaffolds and 77% for crosslinked scaffolds. All scaffolds exhibited good cell attachment while AuNP-1X scaffolds showed the greatest cell proliferation with a 74% increase in dsDNA content from Day 3 to 7. AuNP-2X and AuNP-4X scaffolds generated higher levels of free radicals with AuNP-4X generating over twice as much as decellularized scaffolds. This study suggests the capability for gold/porcine diaphragm scaffolds to enhance cell proliferation while the modification of free radical generation appears to be dependent on nanomaterial shape and concentration.

Development and in vitro studies of a polyethylene terephthalate-gold nanoparticle scaffold for improved biocompatibility.

Polyethylene terephthalate (PET) mesh is one of the most commonly used synthetic biomaterials for tension-free hernia repair. In an effort to improve the biocompatibility of PET mesh, gold nanoparticles (AuNP) in various concentrations were conjugated to the PET surface to develop PET-AuNP scaffolds. These novel scaffolds were characterized with Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and differential scanning calorimetry (DSC) to assess the addition of functional groups, presence of AuNPs, and thermal stability of the modified PET mesh, respectively. The biocompatibility of the PET-AuNP scaffolds was evaluated through in vitro cell culture assays. The cellularity of cells exposed to the PET-AuNP scaffolds, as well as the scaffolds' ability to reduce reactive oxygen species, was assessed using L929 murine fibroblasts. Antimicrobial properties of AuNPs conjugated to PET mesh were tested against the bacteria Pseudomonas aeruginosa. Results from the FT-IR showed presence of COOH groups while SEM displayed bonding of AuNPs to the PET surface. DSC results indicated that the PET more than likely did not undergo any detrimental degradation due to the surface modification. Results from the in vitro studies showed that AuNPs, in optimal concentrations (1× concentrations), enhanced cellularity, reduced ROS, and reduced bacteria adhesion to PET. These studies demonstrated enhanced biocompatibility of the AuNP conjugated PET mesh over pristine PET mesh.

Characterization of bionanocomposite scaffolds comprised of amine-functionalized gold nanoparticles and silicon carbide nanowires crosslinked to an acellular porcine tendon.

As one of the most common proteins found in the human body, collagen is regarded as biocompatible and has many properties making it ideal for soft-tissue repair applications. However, collagen matrices fabricated from purified forms of collagen are notoriously weak and easily degraded by the body. The extracellular matrix of many tissues including human dermis, porcine dermis, and porcine small intestine submucosa are often utilized instead, and several of these scaffolds are crosslinked. Crosslinking has been shown to improve the mechanical properties of collagenous tissues and increase their resistance to degradation. In this study we investigated two novel "bionanocomposite" materials in which either gold nanoparticles or silicon carbide nanowires were crosslinked to a porcine tendon. Scanning electron micrographs confirmed that the nanomaterials were successfully crosslinked to the tissues. A collagenase assay, tensile testing, flow cytometry, and bioreactor studies were also performed to further characterize the properties of these novel materials. The results of these studies indicated that crosslinking porcine diaphragm tissues with nanomaterials resulted in scaffolds with improved resistance to enzymatic degradation and appropriate biocompatibility characteristics, thus warranting further study of these materials for soft tissue repair and tissue engineering applications.

Characterization of bionanocomposite scaffolds comprised of amine-functionalized single-walled carbon nanotubes crosslinked to an acellular porcine tendon.

Carbon nanotubes (CNT) possess many unique electrical and mechanical properties that make them useful for a variety of industrial and biomedical applications. They are especially attractive materials for biomedical applications since their dimensions are similar to components of the extracellular matrix. In this study, amine-functionalized single-walled carbon nanotubes were crosslinked to an acellular porcine diaphragm tendon. The resulting bionanocomposite scaffolds were subjected to a number of materials characterization techniques including a collagenase assay, uniaxial tensile testing, modulated differential scanning calorimetry, and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy to determine whether the properties of the original extracellular matrix were altered by the treatment processes. A variety of SWCNT concentrations were investigated. While none of the conditions investigated resulted in bionanocomposites with significantly improved physicochemical properties, no detrimental effects were observed due to any of the processing steps. Future studies should be performed to determine if carbon nanotubes can influence cellular adhesion and function in order to promote rapid integration and remodeling.

In search of the best peritoneal adhesion model: comparison of different techniques in a rat model.

BACKGROUND: Adhesion-related complications after abdominal surgery result in significant morbidity and costs. Results from animal studies investigating prevention or treatment of adhesions are limited due to lack of consistency in existing animal models. The aim of this study was to compare quality and quantity of adhesions in four different models and to find the best model. MATERIALS AND METHODS: This study was approved by the University of Missouri Animal Care and Use Committee (ACUC). Forty female rats were randomly assigned to four different groups of 10 animals each. Adhesion created was performed utilizing the four techniques: Group 1 - parietal peritoneum excision (PPE), Group 2 - parietal peritoneum abrasion (PPA), Group 3 - peritoneal button creation (PBC), and Group 4 - cecal abrasion (CA). Rats were allowed to recover and necropsy was performed on postoperative d 14. Adhesions were scored by an established quantitative and qualitative scoring systems. The midline incision served as the control in each animal. RESULTS: The four groups were not equal with respect to both quantity score (P<0.001) and quality score (P=0.042). The PBC group had the highest quantity of adhesions. The highest quality of adhesion was seen in the PPE group. A multivariate analysis carried out to quantify the performance of each model clearly demonstrated that PBC exhibited the best results in terms of both quantity and quality. CONCLUSIONS: The button technique (PBC) is most consistent and reproducible technique for an intra-abdominal adhesion model. This model can help in the study and development of substances to prevent adhesion formation in the future.

Transvaginal repair of a large chronic porcine ventral hernia with synthetic mesh using NOTES.

BACKGROUND: Ventral incisional hernias still remain a common surgical problem. We tested the feasibility of transvaginal placement of a large synthetic mesh to repair a porcine hernia. METHODS: Seven pigs were used in this survival model. Each animal had creation of a 5-cm hernia defect and underwent a transvaginal repair of the defect with synthetic mesh. A single colpotomy was made using a 12-cm trocar for an overtube. The mesh was cut to size and placed through the trocar. A single-channel gastroscope with an endoscopic atraumatic grasper was used for grasping sutures. Further fascial sutures were placed every 5 cm. RESULTS: Mesh repair was feasible in all 7 animals. Mean operative time was 133 minutes. Technical difficulties were encountered. No gross contamination was seen at the time of necropsy. However, 5 animals had positive mesh cultures; 7 had positive cultures in the rectouterine space in enrichment broth or on direct culture. CONCLUSION: Transvaginal placement of synthetic mesh to repair a large porcine hernia using NOTES is challenging but feasible. Future studies need to be conducted to develop better techniques and determine the significance of mesh contamination.

Materials characterization of explanted polypropylene, polyethylene terephthalate, and expanded polytetrafluoroethylene composites: spectral and thermal analysis.

This study utilized spectral and thermal analysis of explanted hernia mesh materials to determine material inertness and elucidate reasons for hernia mesh explantation. Composite mesh materials, comprised of polypropylene (PP) and expanded polytetrafluoroethylene (ePTFE) mesh surrounded by a polyethylene terephthalate (PET) ring, were explanted from humans. Scanning electron microscopy (SEM) was conducted to visually observe material defects while attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) was used to find chemical signs of surface degradation. Modulated differential scanning calorimetry (MDSC) and thermogravimetric analysis (TGA) gave thermal stability profiles that showed changes in heat of fusion and rate of percent weight loss, respectively. ATR-FTIR scans showed higher carbonyl peak areas as compared to pristine for 91% and 55% of ePTFE and PP explants, respectively. Ninety-one percent of ePTFE explants also exhibited higher C--H stretch peak areas. Seventy-three percent of ePTFE explants had higher heats of fusion while 64% of PP explants had lower heats of fusion with respect to their corresponding pristines. Only 9% of PET explants exhibited a lower heat of fusion than pristine. Seventy-three percent of ePTFE explants, 73% of PP explants, and only 18% of PET explants showed a decreased rate of percent weight loss as compared to pristine. The majority of the PP and ePTFE mesh explants demonstrated oxidation and crosslinking, respectively, while the PET ring exhibited breakdown at the sites of high stress. The results showed that all three materials exhibited varied degrees of chemical degradation suggesting that a lack of inertness in vivo contributes to hernia mesh failure.

Early results of midline hernia repair using a minimally invasive component separation technique.

A minimally invasive component separation may lead to a dynamic abdominal wall after hernia repair, with reduced complications. We present early results of our patients undergoing this technique. Five patients were selected for open midline repairs; three with chronic infections, one with a prior midline skin graft, and one who desired a primary, tension-free repair. These three males and two females had a mean age of 50.8 +/- 21.1 years and body mass index of 30.9 +/- 6.2. The mean number of previous abdominal operations was 7 +/- 3.4 and previous attempted hernia repairs were 4 +/- 2.7. All patients had a midline laparotomy with lysis of adhesions. An endoscopic component separation was then performed bilaterally. Drains were left in the dissection bed. All patients had the midline closed; four received biologic mesh underlays. Mean operative time was 227 minutes +/- 49. Mean length of stay (LOS) was 9.2 days +/- 3.6. Early median follow-up was 6 months (range 0.25-9). Two patients required postop transfusions, and two patients had mild complications of the midline wound (hematoma, infection). To date, one recurrence was diagnosed by CT scan. Early evaluation of adopting the minimally invasive (MIS) component separation demonstrates minimal complications and good initial outcomes.

Transgastric placement of biologic mesh to the anterior abdominal wall.

BACKGROUND: Incisional hernia repairs have a risk of wound complications that may be decreased using a natural orifice transluminal endoscopic surgery (NOTES) approach. The aim of this study was to determine the feasibility and safety of transgastric mesh placement to the anterior abdominal wall in a porcine model as a precursor to future studies of NOTES ventral hernia repair. METHODS: The procedure was done under sterile conditions with a double lumen endoscope using a plastic overtube. The endoscope was placed in the stomach preloaded with an overtube. Entrance of the endoscope and overtube into the peritoneal cavity was performed with the percutaneous endoscopic gastrostomy (PEG) technique. A 13 x 15 cm Surgisis Gold mesh with four corner sutures was delivered through the overtube. Transfascial suture passer and endoscopic grasper were used to externalize the sutures and attach the mesh to the anterior abdominal wall. The gastrotomy was closed with a transabdominal gastropexy. The pigs were sacrificed at 2 weeks. RESULTS: Mesh placement was performed in five pigs. Operative time was 215 min (standard deviation, SD 99 min). The most difficult portion of the procedure involved manipulating the gastric overtube, likely exposing the mesh to bacteria in the stomach. Culture-positive abscesses were present at the mesh in 3/5 animals. The mesh appeared intact in 4/5 animals; one of the infected meshes had delamination of 50% of the mesh. Adhesions to the mesh surface varied from 2% to 100%. At 2 weeks, median mesh size was 116 cm2 (range 96-166 cm2) and median contraction was 41% (range 15-51%). Histologic evaluations demonstrated marked inflammation and fibrosis progressing into the mesh material. CONCLUSIONS: Totally endoscopic transgastric delivery and fixation of a biologic mesh to the anterior abdominal wall is feasible. Challenges remain in designing systems for mesh delivery that exclude gastric content. Once these problems can be surmounted NOTES ventral hernia repair may become an option in man.

Colonic sterilization for natural orifice translumenal endoscopic surgery (NOTES) procedures: a comparison of two decontamination protocols.

BACKGROUND: This study aimed to evaluate the effect of two different sterilization protocols on the bacterial counts in the swine colon as preparation for natural orifice translumenal endoscopic surgery (NOTES) surgery. METHODS: In this study, 16 swine were randomized to two different colonic sterilization protocols: low colonic irrigation using 300 ml of a 1:1 dilution of 10% povidone-iodine (Betadine) with sterile saline, followed by 1 g of cefoxitin dissolved in 300 ml of saline or two consecutive 300-ml irrigations using a quaternary ammonium antimicrobial agent (Onamer M). Colonic cultures were taken before colonic cleansing after a decontamination protocol and after completion of the NOTES procedure. The Invitrogen live/dead bacterial viability kit was used to assess for change in the bacterial load. A qualitative culture of peritoneal fluid was obtained at the end of the NOTES procedure. Colon mucosal biopsies obtained immediately after the sterilization procedure and at the 2-week necropsy point were evaluated for mucosal changes. RESULTS: Protocol 1 resulted in an average 93% decrease in live colonic bacteria versus 90% with protocol 2 (nonsignificant difference). After a NOTES procedure, group 1 had a 62% increase in live bacteria and group 2 had a 31% increase (nonsignificant difference). Peritoneal cultures also were obtained. Bacteria were isolated from the peritoneal fluid of all the animals, and two or more species were isolated from 75% of the animals. There was no evidence of peritoneal infection at necropsy. Reactive epithelial changes and mild inflammation were the only pathologic abnormalities. No changes were noted at histologic evaluation of colonic mucosa after 2 weeks, demonstrating that these were temporary changes. CONCLUSION: Colonic irrigation with Betadine and antibiotics are as effective for bacterial decontamination of the swine colon as a quaternary ammonium compound. The results of this study support the use of either protocol. Despite thorough decontamination, peritoneal contamination occurs. The significance of this for humans is unknown.

Placement of a covered polyester stent prevents complications from a colorectal anastomotic leak and supports healing: randomized controlled trial in a large animal model.

BACKGROUND: Anastomotic leaks after colorectal operation continue to be a significant cause of morbidity. A covered endoluminal stent could seal a leak and eliminate the need for diversion. The aim of this study was to test the efficacy of a temporary covered stent to prevent leak related complications. METHODS: Sixteen adult pigs (80-120 lbs) underwent open transection of the rectosigmoid followed by anastomosis with a circular stapler. Eight animals (study group) underwent endoscopic placement of a 21-mm covered polyester stent. Eight control group animals were left without stents. In all animals, a 2-cm leak was created along the anterior portion of the anastomosis. The animals were killed after 2 weeks and evaluated for abdominal infection, fistulae, and adhesions. The anastomosis was excised and the following parameters were assessed by a pathologist blinded to treatment: mucosal interruption (mm), inflammatory response, collagen type I and III, granulation, and fibrosis (grade 0-4). RESULTS: Stents were spontaneously expelled between postoperative days 6 and 9. At necropsy, none of the animals in the study group had leak related complications, whereas in the control group, 5 (63%) developed intraabdominal infection (4 abscesses, 1 fistula) at the anastomosis (P = .002). Dense adhesions to the anastomosis were found in 7 (88%) control animals. On histology, anastomotic sites in the study group had significantly less mucosal interruption and granulation. Two pigs in the study group died on postoperative day 7, one due to evisceration and one from bladder necrosis. The mortality result is not different from controls (P = .47), both events seem to be unrelated to stent placement. CONCLUSION: Temporary placement of a covered polyester stent across a colorectal anastomosis prevents leak-related complications and supports the healing of anastomotic leaks.

Gastrotomy creation and closure for NOTES using a gastropexy technique (with video).

BACKGROUND: Safe and efficient gastrotomy creation and closure is pivotal for natural orifice transluminal endoscopic surgery (NOTES). OBJECTIVE: To test a method of transgastric access and closure with commercially available devices. DESIGN: An animal survival study. SETTING: University hospital. PATIENTS: Fifteen pigs. INTERVENTIONS: By using a surgical suture passer, under endoscopic guidance, 3 percutaneous stay sutures were placed, in a triangular fashion, through the gastric wall. A gastrotomy was created with a dilation balloon, which was introduced over a guidewire through the gastric wall in the center of the 3 sutures. After performing a NOTES procedure, the gastrotomy was closed by tying the sutures. Necropsies were performed after 2 to 4 weeks. MAIN OUTCOME MEASUREMENTS: Success and time of gastrotomy creation and closure, and intraoperative and postoperative complications. RESULTS: Gastrotomies were successfully created and closed in all the animals. The median time to create a gastrotomy was 19 minutes (range 11-85 minutes), and the median closure time was 1 minute (range 1-45 minutes). One pig died on postoperative day 1 because of peritonitis caused by a leaking gastrotomy site that extended beyond the stay sutures. There were no other gastrotomy-related complications. All gastrotomies were well healed at the necropsy. LIMITATION: No control group. CONCLUSIONS: We evaluated a simple method by using the principles of the PEG technique combined with a gastropexy, which is familiar to the majority of endoscopists. Strict attention to the gastrotomy site is needed, because one leak was from the gastrotomy site that extended beyond the stay sutures.

Endoscopic colotomy closure for natural orifice transluminal endoscopic surgery using a T-fastener prototype in comparison to conventional laparoscopic suture closure.

BACKGROUND: Safe and efficient endoscopic closure of a colotomy is essential for transcolonic peritoneal access or endoscopic full-thickness resection of the colon, if open or laparoscopic surgery is to be avoided. OBJECTIVE: To compare the feasibility and safety of colotomy closure with the newly developed Tissue Approximation System (TAS, Ethicon Endo-Surgery, Inc.) to conventional laparoscopic suture closure. DESIGN: Prospective randomized survival animal study involving 16 pigs. SETTING: University hospital. INTERVENTIONS: Pigs were randomized for closure of a 2- to 3-cm full-thickness colotomy with the TAS or with a conventional laparoscopic running suture. MAIN OUTCOME MEASUREMENTS: Success of colotomy closure, time of colotomy closure, postoperative infection, and complication rates. RESULTS: Colotomies were successfully closed in all animals. Median closure time (range) was 39.5 minutes (25-95 min) in the TAS group and 23 minutes (16-40 min) in the laparoscopic group (P = .0134). There were no postoperative infections or complications. LIMITATIONS: Closure with the TAS was performed under laparoscopic vision. There was no control group without closure of the colotomy site. CONCLUSIONS: Colotomies are safely closed with the TAS with comparable results to laparoscopic closure. The TAS may serve as a useful tool to close full-thickness colon defects or colotomy sites made for transluminal endoscopic procedures.