Long-term outcomes of per-oral endoscopic myotomy compared to laparoscopic Heller myotomy for achalasia: a single-center experience.

INTRODUCTION: Many centers have reported excellent short-term efficacy of per-oral endoscopic myotomy (POEM) for the treatment of achalasia. However, long-term data are limited and there are few studies comparing the efficacy of POEM versus Heller Myotomy (HM). AIMS: To compare the long-term clinical efficacy of POEM versus HM. METHODS: Using a retrospective, parallel cohort design, all cases of POEM or HM for achalasia between 2010 and 2015 were assessed. Clinical failure was defined as (a) Eckardt Score > 3 for at least 4 weeks, (b) achalasia-related hospitalization, or (c) repeat intervention. All index manometries were classified via Chicago Classification v3. Pre-procedural clinical, manometric, radiographic data, and procedural data were reviewed. RESULTS: 98 patients were identified (55 POEM, 43 Heller) with mean follow-up of 3.94 years, and 5.44 years, respectively. 83.7% of HM patients underwent associated anti-reflux wrap (Toupet or Dor). Baseline clinical, demographic, radiographic, and manometric data were similar between the groups. There was no statistical difference in overall long-term success (POEM 72.7%, HM 65.1% p = 0.417, although higher rates of success were seen in Type III Achalasia in POEM vs Heller (53.3% vs 44.4%, p < 0.05). Type III Achalasia was the only variable associated with failure on a univariate COX analysis and no covariants were identified on a multivariate Cox regression. There was no statistical difference in GERD symptoms, esophagitis, or major procedural complications. CONCLUSION: POEM and HM have similar long-term (4-year) efficacy with similar adverse event and reflux rates. POEM was associated with greater efficacy in Type III Achalasia.

Situating Artificial Intelligence in Surgery: A Focus on Disease Severity.

OBJECTIVES: Artificial intelligence (AI) has numerous applications in surgical quality assurance. We assessed AI accuracy in evaluating the critical view of safety (CVS) and intraoperative events during laparoscopic cholecystectomy. We hypothesized that AI accuracy and intraoperative events are associated with disease severity. METHODS: One thousand fifty-one laparoscopic cholecystectomy videos were annotated by AI for disease severity (Parkland Scale), CVS achievement (Strasberg Criteria), and intraoperative events. Surgeons performed focused video review on procedures with ≥1 intraoperative events (n = 335). AI versus surgeon annotation of CVS components and intraoperative events were compared. For all cases (n = 1051), intraoperative-event association with CVS achievement and severity was examined using ordinal logistic regression. RESULTS: Using AI annotation, surgeons reviewed 50 videos/hr. CVS was achieved in ≤10% of cases. Hepatocystic triangle and cystic plate visualization was achieved more often in low-severity cases (P < 0.03). AI-surgeon agreement for all CVS components exceeded 75%, with higher agreement in high-severity cases (P < 0.03). Surgeons agreed with 99% of AI-annotated intraoperative events. AI-annotated intraoperative events were associated with both disease severity and number of CVS components not achieved. Intraoperative events occurred more frequently in high-severity versus low-severity cases (0.98 vs 0.40 events/case, P < 0.001). CONCLUSIONS: AI annotation allows for efficient video review and is a promising quality assurance tool. Disease severity may limit its use and surgeon oversight is still required, especially in complex cases. Continued refinement may improve AI applicability and allow for automated assessment.

Novel device to detect enterotomies in real time during laparoscopy: first in human trial during Roux-en-y gastric bypass.

BACKGROUND: Undetected bowel perforations occur in 0.3-1% of laparoscopic surgical procedures with an associated mortality rate of 5.3%. OBJECTIVE: The purpose of the study was to evaluate the clinical feasibility of a novel medical device to accurately detect bowel gas, specifically hydrogen (H2) and methane (CH4), from a sample of gas from the abdominal cavity during laparoscopic surgery when a known bowel wall perforation has occurred. SETTING: University (Academic) Hospital. METHODS: A prospective single arm study was composed of 8 patients undergoing a standard laparoscopic roux-en-y gastric bypass. At seven time points during the operation intra-abdominal gas was pulled from the abdominal cavity and analyzed using the novel device for H2 and CH4. The time points included after insufflation (T1), after first jejunotomy (T2), after closure of jejunotomy (T3), after recycle of carbon dioxide gas (T4), after gastrostomy (T5), after jejunotomy (T6), at procedure end (T7). RESULTS: Eight patients were enrolled in the study; in 7 (87.5%) patients data from all 7 time points were obtained. After the first opening of the small bowel (T2) mean hydrogen levels were significantly increased compared to baseline hydrogen levels (T1, T4, T7) (p < 0.001). At all time points, there was no significant detection of methane. There were no intra-operative or post-operative complications during the study. CONCLUSION: Hydrogen gas is released into the intra-abdominal cavity when bowel is opened and can be detected in real time using a novel device during laparoscopic surgery. The presence or absence of hydrogen directly correlates to whether the bowel is open (perforated) or intact. This device could be used in the future to detect unintended bowel perforations during laparoscopic surgery, prior to the conclusion of the operation. This technology could also potentially lead to novel mechanism for detecting postoperative leaks using gas detection technology.

Surgical Anti-Reflux Options Beyond Fundoplication.

PURPOSE OF REVIEW: This paper provides an overview of current and future surgical interventions available for the management of gastroesophageal reflux disease (GERD) beyond the well established and recognized fundoplication. Review the current indications and outcomes of these surgical procedures. RECENT FINDINGS: Fundoplication has been a cornerstone of the surgical management of GERD. However, other effective surgical options exist and can be considered based on prior interventions as well as patient, anatomical or other factors. These options are intended to address some of the shortcomings or potential complications of fundoplication such as symptom recurrence, dysphagia, or gas bloating, for example. Alternative procedures to fundoplication include magnetic sphincter augmentation, electrical stimulation and Roux-en-Y gastric bypass. The indication for surgical management remains failure of or inability to tolerate medical therapy.

SAGES TAVAC safety and effectiveness analysis: da Vinci ® Surgical System (Intuitive Surgical, Sunnyvale, CA).

BACKGROUND: The da Vinci(®) Surgical System (Intuitive Surgical, Sunnyvale, CA, USA) is a computer-assisted (robotic) surgical system designed to enable and enhance minimally invasive surgery. The Food and Drug Administration (FDA) has cleared computer-assisted surgical systems for use by trained physicians in an operating room environment for laparoscopic surgical procedures in general, cardiac, colorectal, gynecologic, head and neck, thoracic and urologic surgical procedures. There are substantial numbers of peer-reviewed papers regarding the da Vinci(®) Surgical System, and a thoughtful assessment of evidence framed by clinical opinion is warranted. METHODS: The SAGES da Vinci(®) TAVAC sub-committee performed a literature review of the da Vinci(®) Surgical System regarding gastrointestinal surgery. Conclusions by the sub-committee were vetted by the SAGES TAVAC Committee and SAGES Executive Board. Following revisions, the document was evaluated by the TAVAC Committee and Executive Board again for final approval. RESULTS: Several conclusions were drawn based on expert opinion organized by safety, efficacy, and cost for robotic foregut, bariatric, hepatobiliary/pancreatic, colorectal surgery, and single-incision cholecystectomy. CONCLUSIONS: Gastrointestinal surgery with the da Vinci(®) Surgical System is safe and comparable, but not superior to standard laparoscopic approaches. Although clinically acceptable, its use may be costly for select gastrointestinal procedures. Current data are limited to the da Vinci(®) Surgical System; further analyses are needed.

Deep brain stimulation for obesity: rationale and approach to trial design.

Obesity is one of the most serious public health concerns in the US. While bariatric surgery has been shown to be successful for treatment of morbid obesity for those who have undergone unsuccessful behavioral modification, its associated risks and rates of relapse are not insignificant. There exists a neurological basis for the binge-like feeding behavior observed in morbid obesity that is believed to be due to dysregulation of the reward circuitry. The authors present a review of the evidence of the neuroanatomical basis for obesity, the potential neural targets for deep brain stimulation (DBS), as well as a rationale for DBS and future trial design. Identification of an appropriate patient population that would most likely benefit from this type of therapy is essential. There are also significant cost and ethical considerations for such a neuromodulatory intervention designed to alter maladaptive behavior. Finally, the authors present a consolidated set of inclusion criteria and study end points that should serve as the basis for any trial of DBS for obesity.

Development of an in vitro ventricular shunt material testing model and utility of PEG as antifouling coating.

OBJECTIVE: CSF shunts, most commonly the ventriculoperitoneal shunt, remain a first and last line of management for children and adults with hydrocephalus. However, the failure rates of these shunts are extremely high, leaving many patients with the need for revision surgical procedures. The objective of this study was to develop a model to assess the efficacy of a nonfouling ventricular catheter. A second objective was to test polyethylene glycol (PEG) as an antifouling coating. METHODS: Microglial cells were grown on medical-grade catheter silicone with biofouling simulated by collagen incubation over a range of concentrations from 31 to 103 µg/ml and durations from 2 to 18 hours. After ideal fouling conditions were identified, catheter silicone was then coated with PEG as an antifouling surface, and cell growth on this surface was compared to that on uncoated standard catheter silicone. RESULTS: Collagen biofouling increased cell growth on silicone surfaces with an ideal concentration of 69 µg/ml and incubation of 6 hours. PEG coating of silicone catheter material yielded 70-fold lower cell growth (p < 0.0001), whereas collagen-fouled PEG-coated silicone yielded 157-fold lower cell growth (p < 0.0001). CONCLUSIONS: Catheter coating significantly reduced cell growth, particularly in the setting of biofouling. The application of antifouling surfaces to ventricular shunts shows considerable promise for improving efficacy.

Real-time near-infrared fluorescent cholangiography could shorten operative time during robotic single-site cholecystectomy.

BACKGROUND: With the introduction of a new platform, robotic single-site cholecystectomy (RSSC) has been reported as feasible and safe for selected cases. In parallel, the development of real-time near-infrared fluorescent cholangiography using indocyanine green (ICG) has been seen as a help during the dissection, even if the data are still preliminary. The study purpose is to report our experience with ICG RSSC and compare the outcomes to standard RSSC. METHODS: From February 2011 to December 2011, 44 selected patients underwent RSSC for symptomatic cholelithiasis. Among them, 23 (52.3%) were included in an experimental protocol using the ICG, and the remainder (47.7%) underwent standard RSSC. There was no randomization. The endpoints were the perioperative outcomes. This is a prospective study, approved by our local Ethics Committee. RESULTS: There were no differences in terms of patients' characteristics, except that there were more male patients in the ICG group (47.8 vs. 9.5%; p = 0.008). Regarding the surgical data, the overall operative time was shorter for the ICG group, especially for patients with a body mass index (BMI) ≤25 (-24 min) but without reaching statistical significance (p = 0.06). For BMI >25, no differences were observed. Otherwise, there were no differences in terms of conversion, complications, or length of stay between both groups. CONCLUSIONS: A RSSC with a real-time near-infrared fluorescent cholangiography can be performed safely. In addition, for selected patients with a low BMI, ICG could shorten the operative time during RSSC. Larger studies are still required before drawing definitive conclusions.

Contemporary management of adult intussusception: who needs a resection?

BACKGROUND: Surgical resection is often recommended in adults with intestinal intussusception (AI) because of its potential association with malignancy. We provide a contemporary algorithm for managing AI by focusing on the probability of discovering a lead point. METHODS: This is a retrospective study of adult patients with computed tomography (CT)-confirmed intussusception who underwent operative management of AI between 1996 and 2011 at a single academic institution. RESULTS: Sixty-four patients were diagnosed with AI by CT scan and then managed operatively. The incidence of colonic (CI), small bowel (SBI), and retrograde intussusception (RI) was 14, 55, and 31 %, respectively. All patients with CI had a lead point, whereas none were found among patients with RI. Some 46 % of patients with SBI had a lead point. The probability of discovering a lead point in SBI was increased by past history of malignancy (RR, 3.7, p < 0.001), a mass seen on preoperative CT scan (RR, 2.9, p = 0.005), and age over 60 years (RR, 2.2, p = 0.07). CONCLUSIONS: A pathologic lead point is likely with CI but not with RI. Patients with SBI who are over the age of 60 years and have a history of malignancy or a mass noted on CT scan have a higher likelihood of harboring a pathologic lead point.

[Medical technology innovation: why get involved and how?]. / Innovation dans les technologies médicales: pourquoi et comment s'impliquer?

Medical technologies are an intrinsic part of our daily practice. More than a simple recipient of novel medical devices, clinicians have a unique role to play in medtech innovation. They are invaluable assets for testing devices and guiding manufacturers towards the most clinically relevant solutions. More importantly, they have a direct view on patient needs and can therefore identify unmet clinical needs. As these skills are not part of medical school curricula, new centers in medtech innovation education are arising across Europe following the success of US programs. These centers offer a full curriculum in medtech innovation so that doctors can more actively participate and foster innovation in their field. This new knowledge can allow us to initiate our own innovations and potentially influence the future of our own practice.

[Robotic general surgery: where do we stand in 2013?]. / Chirurgie générale robotique: où en sommes-nous en 2013?

While the number of publications concerning robotic surgery is increasing, the level of evidence remains to be improved. The safety of robotic approach has been largely demonstrated, even for complex procedures. Yet, the objective advantages of this technology are still lacking in several fields, notably in comparison to laparoscopy. On the other hand, the development of robotic surgery is on its way, as the enthusiasm of the public and the surgical community can testify. Still, clear clinical indications remain to be determined in the field of general surgery. The study aim is to review the current literature on robotic general surgery and to give the reader an overview in 2013.

A National Study on Training Innovation in US Medical Education.

Introduction Traditional medical education has leaned heavily on memorization, pattern recognition, and learned algorithmic thinking. Increasingly, however, creativity and innovation are becoming recognized as a valuable component of medical education. In this national survey of Association of American Medical Colleges (AAMC) member institutions, we seek to examine the current landscape of exposure to innovation-related training within the formal academic setting. Methods Surveys were distributed to 168 of 171 AAMC-member institutions (the remaining three were excluded from the study for lack of publicly available contact information). Questions assessed exposure for medical students among four defined innovation pillars as follows: (1) medical humanities, (2) design thinking, (3) entrepreneurship, or (4) technology transfer. Chi-squared analysis was used to assess statistical significance between schools, comparing schools ranked in the top 20 by the US News and World Report against non-top 20 respondents, and comparing schools that serve as National Institutes of Health (NIH) Clinical and Translational Science Awards (CTSA) program hubs against non-CTSA schools. Heat maps for geospatial visualization of data were created using ArcGIS (ArcMAP 10.6) software (Redlands, CA: Environmental Systems Research Institute). Results The overall response rate was 94.2% with 161 schools responding. Among respondents, 101 (63%) reported having medical humanities curricula at their institution. Design thinking offerings were noted at 51/161 (32%) institutions. Support for entrepreneurship was observed at 51/161 institutions (32%), and technology transfer infrastructure was confirmed at 42/161 (26%) of institutions. No statistically significant difference was found between top 20 schools and lower 141 schools when comparing schools with no innovation programs or one or more innovation programs (p=0.592), or all four innovation programs (p=0.108). CTSA programs, however, did show a statistically significant difference (p<0.00001) when comparing schools with no innovation programs vs. one or more programs, but not when comparing to schools with all four innovation programs (p=0.639). Conclusion This study demonstrated an overwhelming prevalence of innovation programs in today's AAMC medical schools, with over 75% of surveyed institutions offering at least one innovation program. No statistically significant trend was seen in the presence of zero programs, one or more, or all four programs between top 20 programs and the remaining 141. CTSA hub schools, however, were significantly more likely to have at least one program vs. none compared to non-CTSA hub schools. Future studies would be valuable to assess the long-term impact of this trend on medical student education.

Magnetic pancreaticobiliary stents and retrieval system: obviating the need for repeat endoscopy (with video).

BACKGROUND: Plastic stents are routinely placed in the pancreaticobiliary system to facilitate drainage. A second endoscopy is often required for stent removal. We have developed magnetic pancreaticobiliary stents that can be removed by using an external hand-held magnet, thereby obviating the need for a second endoscopy. OBJECTIVE: To develop and test magnetic pancreaticobiliary stents and retrieval system in ex-vivo and in-vivo porcine models. SETTING: Animal laboratory. DESIGN: Benchtop and animal study. ANIMALS: 5 pigs. INTERVENTIONS: Design: Computer simulations determined both the optimal design of cylindrical magnets attached to the distal aspect of existing plastic stents and the optimal design of the external hand-held magnet. Benchtop ex-vivo experiments measured magnetic force to validate the design. In-vivo analysis: In 5 Yorkshire pigs, magnetic stents were deployed into the common bile duct by using a conventional duodenoscope. An external hand-held magnet was applied for stent removal. Stent insertion and removal times were recorded. MAIN OUTCOME MEASUREMENTS: Technical feasibility. RESULTS: Magnetic stents of varying lengths and calibers were successfully created. In ex-vivo testing, the capture distance was 10.0 cm. During in-vivo testing, the magnetic stents were inserted and removed easily. The mean insertion and removal times were 3.2 minutes and 33 seconds, respectively. LIMITATIONS: Animal study, small numbers. CONCLUSIONS: Magnetic pancreaticobiliary stents and associated retrieval system were successfully designed and tested in the acute porcine model. An external, noninvasive means of stent removal potentially obviates the need for a second endoscopy, which could represent a major gain both for patients and in health care savings.

Laparoscopic cholecystectomy after a quarter century: why do we still convert?

BACKGROUND: Laparoscopic cholecystectomy (LC) is the gold standard procedure for gallbladder removal. However, conversion to open surgery is sometimes needed. The factors underlying a surgeon's decision to convert a laparoscopic case to an open case are complex and poorly understood. With decreasing experience in open cholecystectomy, this procedure is however no longer the "safe" alternative it once was. With such an impending paradigm shift, this study aimed to identify the main reasons for conversion and ultimately to develop guidelines to help reduce the conversion rates. METHODS: Using the National Surgical Quality Improvement Program (NSQIP) database and financial records, the authors retrospectively reviewed 1,193 cholecystectomies performed at their institution from 2002 to 2009 and identified 70 conversions. Two independent surgeons reviewed the operative notes and determined the reasons for conversion. The number of ports at the time and the extent of dissection before conversion were assessed and used to create new conversion categories. Hospital length of stay (LOS), 30-day complications, operative times and charges, and hospital charges were compared between the new groups. RESULTS: In 91% of conversion cases, the conversion was elective. In 49% of these conversions, the number of ports was fewer than four. According to the new conversion categories, most conversions were performed after minimal or no attempt at dissection. There were no differences in LOS, complications, operating room charges, or hospital charges between categories. Of the six emergent conversions (9%), bleeding and concern about common bile duct (CBD) injury were the main reasons. One CBD injury occurred. CONCLUSIONS: In 49% of the cases, conversion was performed without a genuine attempt at laparoscopic dissection. Considering this new insight into the circumstances of conversion, the authors recommend that surgeons make a genuine effort at a laparoscopic approach, as reflected by placing four ports and trying to elevate the gallbladder before converting a case to an open approach.

Beyond 5 years: a matched cohort of sleeve gastrectomy versus gastric bypass.

BACKGROUND: Laparoscopic sleeve gastrectomy (LSG) has demonstrated excellent short-term outcomes. However, existing studies suffer from loss to follow-up, and most long-term data focus on laparoscopic Roux-en-Y gastric bypass (LRYGB). This study compares weight loss in patients ≥5 years from LSG with that in matched patients who underwent LRYGB. OBJECTIVES: The purpose of this study was to compare long-term weight loss in patients undergoing LRYGB and LSG. SETTING: University hospital, United States. METHODS: We retrospectively evaluated patients who underwent LSG before August 2012 with follow-up data ≥5 years. LSG patients were matched 1:1 with LRYGB patients by sex, age at surgery, and preoperative body mass index. Univariate and multivariate analyses were performed with weight loss at the longest duration the primary outcome. RESULTS: One-hundred and sixty-five patients underwent LSG during the study period. Long-term follow-up data (≥5 years) were available for 85 patients (52%). There were no preoperative differences between those with and without follow-up data. Six LSG patients (7%) were excluded because they underwent reoperation that altered intestinal anatomy. Of the 79 patients remaining, 75 were matched with post-LRYGB patients. The average follow-up period was 6.4 years for LSG patients and 6.5 years for LRYGB patients (P = .08, not significant). Change in body mass index was 6.81 kg/m2 for LSG patients and 13.11 kg/m2 for LRYGB patients. Percentage of total body weight loss was 15.25% for LSG patients and 28.73% for LRYGB patients. Percentage of excess body weight loss was 37% for LSG patients and 67% for LRYGB patients (P < .0001). Weight loss for LSG patient follow-up in clinic versus outside the clinic was 46% versus 34% (P = .18, not significant). CONCLUSIONS: LSG is now the most common bariatric surgery in the United States. Long-term data are needed to confirm that observed short-term favorable outcomes are maintained. Recent studies have produced divergent results. We observed significantly less weight loss at ≥5 years in LSG patients compared with matched LRYGB patients.

Can responsive deep brain stimulation be a cost-effective treatment for severe obesity?

OBJECTIVE: A first-in-human responsive deep brain stimulation (rDBS) trial (NCT03868670) for obesity is under way, which is based on promising preclinical evidence. Given the upfront costs of rDBS, it is prudent to examine the success threshold for cost-effectiveness compared with laparoscopic Roux-en-Y gastric bypass (LRYGB). METHODS: Efficacy and safety data on LRYGB and safety data on rDBS were collected for established indications through a literature search. The success threshold was defined as minimum BMI reduction. Treatment costs were calculated via Medicare national reimbursement data. RESULTS: LRYGB had a mean BMI reduction of 13.75 kg/m2 . Based on adverse events, LRYGB was a less-preferred health state (overall adverse event utility of 0.96 [0.02]) than rDBS (0.98 [0.01]), but LRYGB ($14,366 [$6,410]) had a significantly lower treatment cost than rDBS ($29,951 [$4,490]; p < 0.0001). Therefore, for rDBS to be cost-effective compared with LRYGB, the multiple models yielded a success threshold range of 13.7 to 15.2 kg/m2 . CONCLUSIONS: This study established a preliminary efficacy success threshold for rDBS to be cost-effective for severe obesity, and results from randomized controlled trials are needed. This analysis allows for interpretation of the economic impact of advancing rDBS for obesity in light of ongoing trial results and suggests an attainable threshold is needed for cost-effectiveness.

Literature review on antiobesity medication use for metabolic and bariatric surgery patients from the American Society for Metabolic and Bariatric Surgery Clinical Issues Committee.

The following literature search is in response to inquiries made to the American Society for Metabolic and Bariatric Surgery (ASMBS) regarding antiobesity medication (AOM) use in patients who are having or have already had metabolic and bariatric surgery (MBS). These recommendations are based on current clinical knowledge, expert opinion, and published peer-reviewed scientific evidence available at this time. This paper is not intended to establish a local, regional, or national standard of care. The paper will be revised in the future as additional evidence becomes available.

SARS-CoV-2 infection drives an inflammatory response in human adipose tissue through infection of adipocytes and macrophages.

Obesity, characterized by chronic low-grade inflammation of the adipose tissue, is associated with adverse coronavirus disease 2019 (COVID-19) outcomes, yet the underlying mechanism is unknown. To explore whether severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection of adipose tissue contributes to pathogenesis, we evaluated COVID-19 autopsy cases and deeply profiled the response of adipose tissue to SARS-CoV-2 infection in vitro. In COVID-19 autopsy cases, we identified SARS-CoV-2 RNA in adipocytes with an associated inflammatory infiltrate. We identified two distinct cellular targets of infection: adipocytes and a subset of inflammatory adipose tissue-resident macrophages. Mature adipocytes were permissive to SARS-CoV-2 infection; although macrophages were abortively infected, SARS-CoV-2 initiated inflammatory responses within both the infected macrophages and bystander preadipocytes. These data suggest that SARS-CoV-2 infection of adipose tissue could contribute to COVID-19 severity through replication of virus within adipocytes and through induction of local and systemic inflammation driven by infection of adipose tissue-resident macrophages.

Pilot study of responsive nucleus accumbens deep brain stimulation for loss-of-control eating.

Cravings that precede loss of control (LOC) over food consumption present an opportunity for intervention in patients with the binge eating disorder (BED). In this pilot study, we used responsive deep brain stimulation (DBS) to record nucleus accumbens (NAc) electrophysiology during food cravings preceding LOC eating in two patients with BED and severe obesity (trial registration no. NCT03868670). Increased NAc low-frequency oscillations, prominent during food cravings, were used to guide DBS delivery. Over 6 months, we observed improved self-control of food intake and weight loss. These findings provide early support for restoring inhibitory control with electrophysiologically-guided NAc DBS. Further work with increased sample sizes is required to determine the scalability of this approach.

An implantable wireless biosensor for the immediate detection of upper GI bleeding: a new fluorescein-based tool for diagnosis and surveillance (with video).

BACKGROUND: Early recurrent hemorrhage after endoscopic intervention for acute upper GI bleeding (UGIB) can approach 20% and leads to increased morbidity and mortality. Little has changed over the past several decades regarding immediate posthemorrhage surveillance, and there has likewise been no significant improvement in outcomes. OBJECTIVE: To develop and test an endoscopically implantable wireless biosensor for real-time detection of fluorescein-labeled blood in ex vivo and in vivo porcine models of UGIB. SETTING: Animal laboratory. DESIGN: Benchtop and acute animal studies. SUBJECTS: Five pigs. INTERVENTIONS: UGIB models were surgically created in living pigs. Biosensors were endoscopically deployed in the stomach using standard endoscopic clips. The ability to detect acute UGIB and estimated blood loss leading to biosensor activation were recorded. Feasibility of wireless data transmission out of the body to an external computer and cell phone was assessed. MAIN OUTCOME MEASUREMENTS: Technical feasibility and immediate complications. RESULTS: A porcine UGIB model was successfully created. Biosensors were able to detect all acute bleeding events and wirelessly transmit out of the body, and successfully sent an emergency text message to the intended cell phone in all cases. Average estimated blood loss leading to biosensor activation was 30 mL (10-75 mL). LIMITATIONS: Animal study; small numbers. CONCLUSIONS: An endoscopically implantable wireless biosensor successfully detected acute hemorrhage in a porcine UGIB model and sent an emergency cell-phone alert in real time.