Drugs prescribed for Phelan-McDermid syndrome differentially impact sensory behaviors in shank3 zebrafish models.

Background: Altered sensory processing is a pervasive symptom in individuals with Autism Spectrum Disorders (ASD); people with Phelan McDermid syndrome (PMS), in particular, show reduced responses to sensory stimuli. PMS is caused by deletions of the terminal end of chromosome 22 or point mutations in Shank3. People with PMS can present with an array of symptoms including ASD, epilepsy, gastrointestinal distress, and reduced responses to sensory stimuli. People with PMS are often medicated to manage behaviors like aggression and/or self-harm and/or epilepsy, and it remains unclear how these medications might impact perception/sensory processing. Here we test this using zebrafish mutant shank3ab PMS models that likewise show reduced sensory responses in a visual motor response (VMR) assay, in which increased locomotion is triggered by light to dark transitions. Methods: We screened three medications, risperidone, lithium chloride (LiCl), and carbamazepine (CBZ), prescribed to people with PMS and one drug, 2-methyl-6-(phenylethynyl) pyridine (MPEP) tested in rodent models of PMS, for their effects on a sensory-induced behavior in two zebrafish PMS models with frameshift mutations in either the N- or C- termini. To test how pharmacological treatments affect the VMR, we exposed larvae to selected drugs for 24 hours and then quantified their locomotion during four ten-minute cycles of lights on-to-off stimuli. Results: We found that risperidone normalized the VMR in shank3 models. LiCl and CBZ had no effect on the VMR in any of the three genotypes. MPEP reduced the VMR in wildtype (WT) to levels seen in shank3 models but caused no changes in either shank3 model. Finally, shank3 mutants showed resistance to the seizure-inducing drug pentylenetetrazol (PTZ), at a dosage that results in hyperactive swimming in WT zebrafish. Conclusions: Our work shows that the effects of drugs on sensory processing are varied in ways that can be highly genotype- and drug-dependent.

Context-dependent hyperactivity in syngap1a and syngap1b zebrafish autism models.

Background and Aims: SYNGAP1 disorder is a prevalent genetic form of Autism Spectrum Disorder and Intellectual Disability (ASD/ID) and is caused by de novo or inherited mutations in one copy of the SYNGAP1 gene. In addition to ASD/ID, SYNGAP1 disorder is associated with comorbid symptoms including treatment-resistant-epilepsy, sleep disturbances, and gastrointestinal distress. Mechanistic links between these diverse symptoms and SYNGAP1 variants remain obscure, therefore, our goal was to generate a zebrafish model in which this range of symptoms can be studied. Methods: We used CRISPR/Cas9 to introduce frameshift mutations in the syngap1a and syngap1b zebrafish duplicates (syngap1ab) and validated these stable models for Syngap1 loss-of-function. Because SYNGAP1 is extensively spliced, we mapped splice variants to the two zebrafish syngap1a and b genes and identified mammalian-like isoforms. We then quantified locomotory behaviors in zebrafish syngap1ab larvae under three conditions that normally evoke different arousal states in wild type larvae: aversive, high-arousal acoustic, medium-arousal dark, and low-arousal light stimuli. Results: We show that CRISPR/Cas9 indels in zebrafish syngap1a and syngap1b produced loss-of-function alleles at RNA and protein levels. Our analyses of zebrafish Syngap1 isoforms showed that, as in mammals, zebrafish Syngap1 N- and C-termini are extensively spliced. We identified a zebrafish syngap1 α1-like variant that maps exclusively to the syngap1b gene. Quantifying locomotor behaviors showed that syngap1ab larvae are hyperactive compared to wild type but to differing degrees depending on the stimulus. Hyperactivity was most pronounced in low arousal settings, with overall movement increasing with the number of mutant syngap1 alleles. Conclusions: Our data support mutations in zebrafish syngap1ab as causal for hyperactivity associated with elevated arousal that is especially pronounced in low-arousal environments.

A brain-wide analysis maps structural evolution to distinct anatomical module.

The vertebrate brain is highly conserved topologically, but less is known about neuroanatomical variation between individual brain regions. Neuroanatomical variation at the regional level is hypothesized to provide functional expansion, building upon ancestral anatomy needed for basic functions. Classically, animal models used to study evolution have lacked tools for detailed anatomical analysis that are widely used in zebrafish and mice, presenting a barrier to studying brain evolution at fine scales. In this study, we sought to investigate the evolution of brain anatomy using a single species of fish consisting of divergent surface and cave morphs, that permits functional genetic testing of regional volume and shape across the entire brain. We generated a high-resolution brain atlas for the blind Mexican cavefish Astyanax mexicanus and coupled the atlas with automated computational tools to directly assess variability in brain region shape and volume across all populations. We measured the volume and shape of every grossly defined neuroanatomical region of the brain and assessed correlations between anatomical regions in surface fish, cavefish, and surface × cave F2 hybrids, whose phenotypes span the range of surface to cave. We find that dorsal regions of the brain are contracted, while ventral regions have expanded, with F2 hybrid data providing support for developmental constraint along the dorsal-ventral axis. Furthermore, these dorsal-ventral relationships in anatomical variation show similar patterns for both volume and shape, suggesting that the anatomical evolution captured by these two parameters could be driven by similar developmental mechanisms. Together, these data demonstrate that A. mexicanus is a powerful system for functionally determining basic principles of brain evolution and will permit testing how genes influence early patterning events to drive brain-wide anatomical evolution.

Novel Husbandry Practices Result in Rapid Rates of Growth and Sexual Maturation Without Impacting Adult Behavior in the Blind Mexican Cavefish.

Animal model systems are dependent on the standardization of husbandry protocols that maximize growth and reduce generation time. The Mexican tetra, Astyanax mexicanus, exists as eyed surface and blind cave dwelling populations. The opportunity for comparative approaches between independently evolved populations has led to the rapid growth of A. mexicanus as a model for evolution and biomedical research. However, a slow and inconsistent growth rate remains a major limitation to the expanded application of A. mexicanus. Fortunately, this temporal limitation can be addressed through husbandry changes that accelerate growth rates while maintaining optimal health outcomes. Here, we describe a husbandry protocol that produces rapid growth rates through changes in diet, feeding frequency, growth sorting and progressive changes in tank size. This protocol produced robust growth rates and decreased the age of sexual maturity in comparison to our previous protocol. To determine whether changes in feeding impacted behavior, we tested fish in exploration and schooling assays. We found no difference in behavior between the two groups, suggesting that increased feeding and rapid growth will not impact the natural variation in behavioral traits. Taken together, this standardized husbandry protocol will accelerate the development of A. mexicanus as a genetic model.

Restoring Shank3 in the rostral brainstem of shank3ab-/- zebrafish autism models rescues sensory deficits.

People with Phelan-McDermid Syndrome, caused by mutations in the SHANK3 gene, commonly exhibit reduced responses to sensory stimuli; yet the changes in brain-wide activity that link these symptoms to mutations in the shank3 gene remain unknown. Here we quantify movement in response to sudden darkness in larvae of two shank3 zebrafish mutant models and show that both models exhibit dampened responses to this stimulus. Using brain-wide activity mapping, we find that shank3-/- light-sensing brain regions show normal levels of activity while sensorimotor integration and motor regions are less active. Specifically restoring Shank3 function in a sensorimotor nucleus of the rostral brainstem enables the shank3-/- model to respond like wild-type. In sum, we find that reduced sensory responsiveness in shank3-/- models is associated with reduced activity in sensory processing brain regions and can be rescued by restoring Shank3 function in the rostral brainstem. These studies highlight the importance of Shank3 function in the rostral brainstem for integrating sensory inputs to generate behavioral adaptations to changing sensory stimuli.

Intestinal dysmotility in a zebrafish (Danio rerio) shank3a;shank3b mutant model of autism.

Background and aims: Autism spectrum disorder (ASD) is currently estimated to affect more than 1% of the world population. For people with ASD, gastrointestinal (GI) distress is a commonly reported but a poorly understood co-occurring symptom. Here, we investigate the physiological basis for GI distress in ASD by studying gut function in a zebrafish model of Phelan-McDermid syndrome (PMS), a condition caused by mutations in the SHANK3 gene. Methods: To generate a zebrafish model of PMS, we used CRISPR/Cas9 to introduce clinically related C-terminal frameshift mutations in shank3a and shank3b zebrafish paralogues (shank3abΔC). Because PMS is caused by SHANK3 haploinsufficiency, we assessed the digestive tract (DT) structure and function in zebrafish shank3abΔC+/- heterozygotes. Human SHANK3 mRNA was then used to rescue DT phenotypes in larval zebrafish. Results: Significantly slower rates of DT peristaltic contractions (p < 0.001) with correspondingly prolonged passage time (p < 0.004) occurred in shank3abΔC+/- mutants. Rescue injections of mRNA encoding the longest human SHANK3 isoform into shank3abΔC+/- mutants produced larvae with intestinal bulb emptying similar to wild type (WT), but still deficits in posterior intestinal motility. Serotonin-positive enteroendocrine cells (EECs) were significantly reduced in both shank3abΔC+/- and shank3abΔC-/- mutants (p < 0.05) while enteric neuron counts and overall structure of the DT epithelium, including goblet cell number, were unaffected in shank3abΔC+/- larvae. Conclusions: Our data and rescue experiments support mutations in SHANK3 as causal for GI transit and motility abnormalities. Reductions in serotonin-positive EECs and serotonin-filled ENS boutons suggest an endocrine/neural component to this dysmotility. This is the first study to date demonstrating DT dysmotility in a zebrafish single gene mutant model of ASD.

Prenatal Neuropathologies in Autism Spectrum Disorder and Intellectual Disability: The Gestation of a Comprehensive Zebrafish Model.

Autism spectrum disorder (ASD) and intellectual disability (ID) are neurodevelopmental disorders with overlapping diagnostic behaviors and risk factors. These include embryonic exposure to teratogens and mutations in genes that have important functions prenatally. Animal models, including rodents and zebrafish, have been essential in delineating mechanisms of neuropathology and identifying developmental critical periods, when those mechanisms are most sensitive to disruption. This review focuses on how the developmentally accessible zebrafish is contributing to our understanding of prenatal pathologies that set the stage for later ASD-ID behavioral deficits. We discuss the known factors that contribute prenatally to ASD-ID and the recent use of zebrafish to model deficits in brain morphogenesis and circuit development. We conclude by suggesting that a future challenge in zebrafish ASD-ID modeling will be to bridge prenatal anatomical and physiological pathologies to behavioral deficits later in life.

Thirty-day readmissions following parathyroidectomy: Evidence from the National Readmissions Database, 2013-2014.

PURPOSE: Parathyroidectomy is one of the most common procedures performed in the United States, and are increasingly being performed safely in the outpatient setting. However, complications from surgery can be life-threatening, and thus an understanding of who may be at risk is essential. We analyzed and compared the risk factors for patients readmitted within 30 days following inpatient parathyroidectomy for primary or secondary hyperparathyroidism. MATERIALS AND METHODS: We reviewed the National Readmissions Database from 2013 to 2014 for patients who received inpatient parathyroidectomy for primary or secondary hyperparathyroidism. The primary outcome was non-elective readmission within 30 days. Multivariate logistic regression was used to analyze risk factor odds ratios for readmission. RESULTS: 7171 patients underwent inpatient parathyroidectomies in 2013 and 2014. 59.89% of parathyroidectomies were performed for primary hyperparathyroidism, with a 5.6% readmission rate. Most common causes of readmission were septicemia (13.69%), hypocalcemia (12.86%), heart failure (10.79%) and renal failure (9.54%). Having Medicare (OR: 1.71, CI:1.14-2.59, p = .01), Medicaid (OR: 3.24, CI: 2.03-5.17, p < .001), and self-paying (OR: 2.43, CI: 1.11-5.32, p = .02), were associated with increased odds of readmission for those with primary hyperparathyroidism. 21.99% of parathyroidectomies were performed for secondary hyperparathyroidism, with a 19.4% readmission rate. Most common causes of readmission were hypocalcemia (22.88%), hungry bone syndrome (14.38%), electrolyte disorders (13.73%), and renal failure (11.11%). CONCLUSION: Patients with secondary hyperparathyroidism are older, poorer and have more comorbidities than patients with primary hyperparathyroidism, and are more likely to be readmitted within 30 days of parathyroidectomy.

The Sestamibi Paradox: Improving Intraoperative Localization of Parathyroid Adenomas.

Accurate localization of parathyroid adenomas allows for minimally invasive parathyroidectomy. This results in a shorter length of stay and increased patient satisfaction. Preoperative Technetium (99mTc) sestamibi scans accurately localize parathyroid adenomas in 70 to 85 per cent of cases. If a patient has a negative scan, it is logical to believe that with a preoperative sestamibi injection, the gamma probe may fail to help find an adenoma. We hypothesized that the gamma probe would not be useful intraoperatively for patients with primary hyperparathyroidism (PHPTH) and a negative sestamibi scan. We retrospectively reviewed the cases of parathyroidectomy at our institution from 2010 to 2016. We selected patients with PHPTH and negative sestamibi scan. In all cases, an attempt was made to find adenomas intraoperatively with the gamma probe. A frozen section was obtained as well as intraoperative parathyroid hormone levels to confirm removal of hyperfunctioning parathyroid tissue. There were 132 parathyroidectomies of which 22 had PHPTH and a negative sestamibi scan. One case was excluded because of insufficient documentation of the intraoperative use of the gamma probe. In 19 of the 21 patients analyzed, the gamma probe successfully identified the adenoma in the operating room (sensitivity, 90.5%). In two patients, the gamma probe did not aid in localization. There were no false positives. In all cases, the parathyroid resected was confirmed by frozen section. The intraoperative parathyroid hormone levels dropped >50 per cent in all but three cases, two of which corresponded to those cases where the gamma probe did not help. Even in patients with negative sestamibi scans, intraoperative use of the gamma probe after preoperative sestamibi injection is effective in localizing parathyroid adenomas.

Function Over Form: Modeling Groups of Inherited Neurological Conditions in Zebrafish.

Zebrafish are a unique cell to behavior model for studying the basic biology of human inherited neurological conditions. Conserved vertebrate genetics and optical transparency provide in vivo access to the developing nervous system as well as high-throughput approaches for drug screens. Here we review zebrafish modeling for two broad groups of inherited conditions that each share genetic and molecular pathways and overlap phenotypically: neurodevelopmental disorders such as Autism Spectrum Disorders (ASD), Intellectual Disability (ID) and Schizophrenia (SCZ), and neurodegenerative diseases, such as Cerebellar Ataxia (CATX), Hereditary Spastic Paraplegia (HSP) and Charcot-Marie Tooth Disease (CMT). We also conduct a small meta-analysis of zebrafish orthologs of high confidence neurodevelopmental disorder and neurodegenerative disease genes by looking at duplication rates and relative protein sizes. In the past zebrafish genetic models of these neurodevelopmental disorders and neurodegenerative diseases have provided insight into cellular, circuit and behavioral level mechanisms contributing to these conditions. Moving forward, advances in genetic manipulation, live imaging of neuronal activity and automated high-throughput molecular screening promise to help delineate the mechanistic relationships between different types of neurological conditions and accelerate discovery of therapeutic strategies.

Two knockdown models of the autism genes SYNGAP1 and SHANK3 in zebrafish produce similar behavioral phenotypes associated with embryonic disruptions of brain morphogenesis.

Despite significant progress in the genetics of autism spectrum disorder (ASD), how genetic mutations translate to the behavioral changes characteristic of ASD remains largely unknown. ASD affects 1-2% of children and adults, and is characterized by deficits in verbal and non-verbal communication, and social interactions, as well as the presence of repetitive behaviors and/or stereotyped interests. ASD is clinically and etiologically heterogeneous, with a strong genetic component. Here, we present functional data from syngap1 and shank3 zebrafish loss-of-function models of ASD. SYNGAP1, a synaptic Ras GTPase activating protein, and SHANK3, a synaptic scaffolding protein, were chosen because of mounting evidence that haploinsufficiency in these genes is highly penetrant for ASD and intellectual disability (ID). Orthologs of both SYNGAP1 and SHANK3 are duplicated in the zebrafish genome and we find that all four transcripts (syngap1a, syngap1b, shank3a and shank3b) are expressed at the earliest stages of nervous system development with pronounced expression in the larval brain. Consistent with early expression of these genes, knockdown of syngap1b or shank3a cause common embryonic phenotypes including delayed mid- and hindbrain development, disruptions in motor behaviors that manifest as unproductive swim attempts, and spontaneous, seizure-like behaviors. Our findings indicate that both syngap1b and shank3a play novel roles in morphogenesis resulting in common brain and behavioral phenotypes.

Does a new surgical residency program increase operating room times?

BACKGROUND: Our country faces a shortage of surgeons; hence, we may anticipate the development of new surgery residencies. Therefore, the question of the effect of a new program on operating room times (ORT) is important. Our primary aim was to compare ORT of 3 common procedures done by attendings alone vs ORT of cases with residents. METHODS: We queried records of 1458 patients from the JFK Medical Center database for laparoscopic cholecystectomy, open inguinal hernia repair, and laparoscopic appendectomy from July 2010 to July 2012. We divided the sample into 2 groups: "attending alone" (2010-2011) and "with residents" (2011-2012). The ORT was calculated by "Cut time" and "Close time," as recorded in the OR. ORT for both groups was calculated using the unpaired t test. RESULTS: Of the total number of patients, 778 underwent laparoscopic cholecystectomy, 407 underwent open inguinal hernia repair, and 273 underwent laparoscopic appendectomy; of these, 620, 315, and 211 procedures, respectively, were done by the attending alone and 158, 92, and 62, respectively, were done with residents. Differences in ORT for the 3 types of surgery were statistically significant (p < 0.001). There was no statistical significance when comparing the first half with the second half of the academic year for residents' ORT. CONCLUSIONS: Resident involvement increases ORT. Cost analysis considering OR time and anesthesia time vs federal funding for Graduate Medical Education is complicated. The benefit of new programs in diminishing the shortage of surgeons cannot be underestimated.

Pretraining and posttraining assessment of residents' performance in the fourth accreditation council for graduate medical education competency: patient communication skills.

HYPOTHESIS: Structured communication curricula will improve surgical residents' ability to communicate effectively with patients. DESIGN AND SETTING: A prospective study approved by the institutional review board involved 44 University of Connecticut general surgery residents. Residents initially completed a written baseline survey to assess general communication skills awareness. In step 1 of the study, residents were randomized to 1 of 2 simulations using standardized patient instructors to mimic patients receiving a diagnosis of either breast or rectal cancer. The standardized patient instructors scored residents' communication skills using a case-specific content checklist and Master Interview Rating Scale. In step 2 of the study, residents attended a 3-part interactive program that comprised (1) principles of patient communication; (2) experiences of a surgeon (role as physician, patient, and patient's spouse); and (3) role-playing (3-resident groups played patient, physician, and observer roles and rated their own performance). In step 3, residents were retested as in step 1, using a crossover case design. Scores were analyzed using Wilcoxon signed rank test with a Bonferroni correction. RESULTS: Case-specific performance improved significantly, from a pretest content checklist median score of 8.5 (65%) to a posttest median of 11.0 (84%) (P = .005 by Wilcoxon signed rank test for paired ordinal data)(n = 44). Median Master Interview Rating Scale scores changed from 58.0 before testing (P = .10) to 61.5 after testing (P = .94). Difference between overall rectal cancer scores and breast cancer scores also were not significant. CONCLUSIONS: Patient communication skills need to be taught as part of residency training. With limited training, case-specific skills (herein, involving patients with cancer) are likely to improve more than general communication skills.

Accuracy of colon tumor localization: Computed tomography scanning as a complement to colonoscopy.

AIM: To determine the utility of computed tomography (CT) scanning in localizing colon tumors. METHODS: At a single tertiary care teaching hospital, a retrospective chart review was conducted on patients who underwent surgery for colon malignancies between January 2004 and May 2006. One hundred and four charts containing all of the following data were reviewed: preoperative colonoscopy report, preoperative CT report, surgical operative report, tumor pathology report. The colon was divided into five segments from the cecum to the sigmoid and the location of the lesions was categorized into one of these areas. The tumor location was considered "erroneous" if its location determined during surgery differed from the location determined by colonoscopy or CT. RESULTS: Over all, tumor location was accurately determined via colonoscopy in 83/104 cases (79.8%) and erroneously in 21/104 (20.2%) of cases. CT scan accurately localized colon tumors in 52/104 (50.0%) of cases, incorrectly localized tumors in 18/104 (17.3%) of cases, and did not detect known tumors in 34/104 (32.7%) of cases. Of the 21 tumors erroneously located by colonoscopy, 11 (52.4%) were accurately localized by CT scan. The average tumor size for all patients in this study was 5.72 (+/- 3.11) cm. The average size of tumors properly located by colonoscopy and CT was 5.39 (+/- 3.34) cm and 6.79 (+/- 3.48) cm, respectively. The average size of the tumors not detected by CT was 3.98 (+/- 1.75) cm. CONCLUSION: CT scanning may be used in concert with colonoscopy to help localize colon tumors.

Association of VA Surgeons annual resident paper award winners: career paths following completion of postgraduate training.

The aims of this study are to track those AVAS podium resident prize winners and to determine patterns of fellowship training type of practice, and primary area of specialization and whether their prize winning paper reflects their current area of specialization today. We also determined whether these residents, once completing their training, ever practiced at a VA hospital, and, whether they have been or currently are members of the AVAS. There have been 43 residents who have won 46 podium awards during this 18 year period. Three/46 (6%) awards were won by a resident twice during different years. Among the 42 locatable residents, 3/42 (7%) are still in surgery training. Among those 39 who are in practice, 30/39 (76%) undertook a clinical fellowship and 22/39 (56%) are in an academic setting. Only 3/39 (8%) has ever worked at a VA hospital; all 3 are currently members of the AVAS. Among those with a specific area of clinical or research specialization (n = 32), in 25/32 (78%), their paper reflects their current area of specialization. Among our cohort of annual AVAS resident prize winners most have taken fellowship training. Greater than 50% pursue academic practice. Among those with an area of specialization, their prize winning paper reflects on their current area of specialization today. Few have ever worked in a VA hospital and thus few have ever been members of the AVAS.

Improving surgical residents' performance on written assessments of cultural competency.

CONTEXT: The pressure to implement cultural-competency training at the level of GME is high. The rapidly diversifying American population and the ACGME demand it, and cultural competency is recognized as a core competency under "Professionalism." OBJECTIVES: The objectives for this study were (1) to assess residents' baseline levels of cultural competence, (2) define barriers to skill-acquisition, and (3) examine efficacy of educational programs in improving cultural competence. SETTING & PARTICIPANTS: In all, 43 residents from the University of Connecticut School of Medicine participated in a prospective, Institutional Review Board (IRB)-approved study. DESIGN: During Step 1 (pretest), baseline performance was recorded using 3 assessments: (1) Healthcare Cultural Competency Test (HCCT), (2) Cultural skills acquisition (CSA), and (3) Clinical Scenarios Test (CSE). During Step 2 (Educational Intervention), a 2-part lecture that focused on principles of cultural competency and continued self-learning was presented. Last, for Step 3 (posttest), the post-program evaluation was administered as in Step 1. MAIN OUTCOME MEASURES: Answers for Step 1 (pretest) and Step 3 (posttest) were compared using a paired t-test for HCCT and CSE and the chi-square test for CSA. RESULTS: Thirty-five replies were evaluated. Every resident performed better on the posttest than the pretest. Specifically, participants showed 88% improvement in their scores on the HCCT (pretest: 360, posttest: 696; p < 0.01), 2-fold improvement on the CSA (pretest: 6, posttest: 12; p < 0.009), and 40% improvement in CSE (pretest mean score = 23.3, posttest = 34.6; p < 0.01). Commonly identified barriers to learning included inadequate teaching tools and absence of formal training. CONCLUSIONS: Surgery residents tested for 3 aspects of cultural competence prior to and after teaching sessions showed marked improvement on all 3 assessment measures after this brief intervention.

The efficacy of intraoperative methylene blue enemas to assess the integrity of a colonic anastomosis.

BACKGROUND: Intraoperative testing of colonic anastomoses is routine in assuring anastamotic integrity. We sought to determine the efficacy of the methylene blue enema (MBE) as an intraoperative test for anastomotic leaks. METHODS: This study is a retrospective review of consecutive colonic operations performed from January 2001 to December 2004 in a community hospital setting by a general surgical group that uses the MBE exclusively. All operations featuring a colonic anastomosis and an intraoperative MBE were studied (n = 229). Intraoperative MBE via a rectal tube was used as the diagnostic test. Intraoperative leak (IOL) rate and clinically significant postoperative leak (POL) rate were the outcome measures. RESULTS: The IOL rate was 4.5% for proximal anastomoses, 8% for distal anastomoses, and 7% of total anastomoses. The POL rate was 3% of anastomosis. There were no other testing methods employed. There were no POLs in cases where an IOL led to concomitant intraoperative repair. POL rate for proximal anastomosis was 0.8% and for distal 3%, for stapled 1% and hand sewn 5%. CONCLUSION: MBE IOL rate is comparable to published IOL rates for other methods of intraoperative testing. The MBE can be applied to proximal and distal anastomosis. Patients who were found to have an IOL, and underwent immediate repair, did not develop a clinical POL.