Uranium isotope fractionation by abiotic reductive precipitation.

Significant uranium (U) isotope fractionation has been observed during abiotic reduction of aqueous U, counter to the expectation that uranium isotopes are only fractionated by bioassociated enzymatic reduction. In our experiments, aqueous U is removed from solution by reductive precipitation onto the surfaces of synthetic iron monosulfide. The magnitude of uranium isotopic fractionation increases with decreasing aqueous U removal rate and with increasing amounts of neutrally charged aqueous Ca-U-CO3 species. Our discovery means that abiotic U isotope fractionation likely occurs in any reducing environment with aqueous Ca ≥ 1 mM, and that the magnitude of isotopic fractionation changes in response to changes in aqueous major ion concentrations that affect U speciation. Our results have implications for the study of anoxia in the ancient oceans and other environments.

Effect of paleoseawater composition on hydrothermal exchange in midocean ridges.

Variations in the Mg, Ca, Sr, and SO4 concentrations of paleoseawater can affect the chemical exchange between seawater and oceanic basalt in hydrothermal systems at midocean ridges (MOR). We present a model for evaluating the nature and magnitude of these previously unappreciated effects, using available estimates of paleoseawater composition over Phanerozoic time as inputs and 87Sr/86Sr of ophiolite epidosites and epidote-quartz veins as constraints. The results suggest that modern hydrothermal fluids are not typical due to low Ca and Sr relative to Mg and SO4 in modern seawater. At other times during the last 500 million years, particularly during the Cretaceous and Ordovician, hydrothermal fluids had more seawater-derived Sr and Ca, a prediction that is supported by Sr isotope data. The predicted 87Sr/86Sr of vent fluids varies cyclically in concert with ocean chemistry, with some values much higher than the modern value of ∼0.7037. The seawater chemistry effects can be expressed in terms of the transfer efficiency of basaltic Ca and Sr to seawater in hydrothermal systems, which varies by a factor of ∼1.6 over the Phanerozoic, with minima when seawater Mg and SO4 are low. This effect provides a modest negative feedback on seawater composition and 87Sr/86Sr changes. For the mid-Cretaceous, the low 87Sr/86Sr of seawater requires either exceptionally large amounts of low-temperature exchange with oceanic crust or that the weathering flux of continentally derived Sr was especially small. The model also has implications for MOR hydrothermal systems in the Precambrian, when low-seawater SO4 could help explain low seawater 87Sr/86Sr.

Morbidity Following Coloanal Anastomosis: A Comparison of Colonic J-Pouch vs Straight Anastomosis.

BACKGROUND: Low rectal tumors are often treated with sphincter-preserving resection followed by coloanal anastomosis. OBJECTIVE: The purpose of this study was to compare the short-term complications following straight coloanal anastomosis vs colonic J-pouch anal anastomosis. DESIGN: Patients were identified who underwent proctectomy for rectal neoplasia followed by coloanal anastomosis in the 2008 to 2013 American College of Surgeons National Surgical Quality Improvement Program database. Demographic characteristics and 30-day postoperative complications were compared between groups. SETTINGS: A national sample was extracted from the American College of Surgeons National Surgical Quality Improvement Project database. PATIENTS: Inpatients following proctectomy and coloanal anastomosis for rectal cancer were selected. MAIN OUTCOME MEASURES: Demographic characteristics and 30-day postoperative complications were compared between the 2 groups. RESULTS: One thousand three hundred seventy patients were included, 624 in the straight anastomosis group and 746 in the colonic J-pouch group. Preoperative characteristics were similar between groups, with the exception of preoperative radiation therapy (straight anastomosis 35% vs colonic J-pouch 48%, p = 0.0004). Univariate analysis demonstrated that deep surgical site infection (3.7% vs 1.4%, p = 0.01), septic shock (2.25% vs 0.8%, p = 0.04), and return to the operating room (8.8% vs 5.0%, p = 0.0006) were more frequent in the straight anastomosis group vs the colonic J-pouch group. Major complications were also higher (23% vs 14%, p = 0.0001) and length of stay was longer in the straight anastomosis group vs the colonic J-pouch group (8.9 days vs 8.1 days, p = 0.02). After adjusting for covariates, major complications were less following colonic J-pouch vs straight anastomosis (OR, 0.57; CI, 0.38-0.84; p = 0.005). Subgroup analysis of patients who received preoperative radiation therapy demonstrated no difference in major complications between groups. LIMITATIONS: This study had those limitations inherent to a retrospective study using an inpatient database. CONCLUSION: Postoperative complications were less following colonic J-pouch anastomosis vs straight anastomosis. Patients who received preoperative radiation had similar rates of complications, regardless of the reconstructive technique used following low anterior resection. See Video Abstract at http://links.lww.com/DCR/A468.

Type I/type III collagen ratio associated with diverticulitis of the colon in young patients.

BACKGROUND: The incidence of diverticulitis in young patients is rising, whereas the type I:III collagen ratio of the colon decreases with age. Perhaps a lower type I:III collagen ratio in younger patients may predispose these patients to the development of the disease. METHOD: The purpose of this study was to evaluate the collagen content and type I:III collagen ratio in patients with diverticulitis versus a control group. Patients who underwent a colon resection were identified. Three groups of patients were created for analysis: those with diverticulitis aged <50 y, >50 y, and a control group. Tissue samples were stained with Sirius red/fast green and photographed. Photos analysis was performed to quantify the amount of type I collagen and type III collagen. The type I:III collagen ratio was calculated for each patient and compared. RESULTS: The quantity of type I collagen and type III collagen was higher in patients with diverticulitis aged >50 y (P = 0.04 and P < 0.0001, respectively); however, the collagen ratio was greatest in those patients with diverticulitis aged <50 y (P = 0.01). Further analysis demonstrated a significant higher type I:III ratio in all patients aged less than 50 y compared with all patients aged over 50 y (P = 0.04). CONCLUSIONS: Our study demonstrated that diverticulitis in the younger patient was not associated with a lower type I:III collagen ratio. It appears that the decrease in collagen ratio of the colon with age is associated with an increase in type III collagen deposition.

Isotopic Evidence for Reductive Immobilization of Uranium Across a Roll-Front Mineral Deposit.

We use uranium (U) isotope ratios to detect and quantify the extent of natural U reduction in groundwater across a roll front redox gradient. Our study was conducted at the Smith Ranch-Highland in situ recovery (ISR) U mine in eastern Wyoming, USA, where economic U deposits occur in the Paleocene Fort Union formation. To evaluate the fate of aqueous U in and adjacent to the ore body, we investigated the chemical composition and isotope ratios of groundwater samples from the roll-front type ore body and surrounding monitoring wells of a previously mined area. The (238)U/(235)U of groundwater varies by approximately 3‰ and is correlated with U concentrations. Fluid samples down-gradient of the ore zone are the most depleted in (238)U and have the lowest U concentrations. Activity ratios of (234)U/(238)U are ∼5.5 up-gradient of the ore zone, ∼1.0 in the ore zone, and between 2.3 and 3.7 in the down-gradient monitoring wells. High-precision measurements of (234)U/(238)U and (238)U/(235)U allow for development of a conceptual model that evaluates both the migration of U from the ore body and the extent of natural attenuation due to reduction. We find that the premining migration of U down-gradient of the delineated ore body is minimal along eight transects due to reduction in or adjacent to the ore body, whereas two other transects show little or no sign of reduction in the down-gradient region. These results suggest that characterization of U isotopic ratios at the mine planning stage, in conjunction with routine geochemical analyses, can be used to identify where more or less postmining remediation will be necessary.

Se Isotopes as Groundwater Redox Indicators: Detecting Natural Attenuation of Se at an in Situ Recovery U Mine.

One of the major ecological concerns associated with the in situ recovery (ISR) of uranium (U) is the environmental release of soluble, toxic selenium (Se) oxyanions generated by mining. Post-mining natural attenuation by the residual reductants in the ore body and reduced down-gradient sediments should mitigate the risk of Se contamination in groundwater. In this work, we investigate the Se concentrations and Se isotope systematics of groundwater and of U ore bearing sediments from an ISR site at Rosita, TX, USA. Our results show that selenate (Se(VI)) is the dominant Se species in Rosita groundwater, and while several up-gradient wells have elevated Se(VI), the majority of the ore zone and down-gradient wells have little or no Se oxyanions. In addition, the δ82SeVI of Rosita groundwater is generally elevated relative to the U ore up to +6.14‰, with the most enriched values observed in the ore-zone wells. Increasing δ82Se with decreasing Se(VI) conforms to a Rayleigh type distillation model with an ε of -2.25‰ ± 0.61‰, suggesting natural Se(VI) reduction occurring along the hydraulic gradient at the Rosita ISR site. Furthermore, our results show that Se isotopes are excellent sensors for detecting and monitoring post-mining natural attenuation of Se oxyanions at ISR sites.

Cellular changes of the colon after mechanical bowel preparation.

BACKGROUND: The purpose of this study was to evaluate the effect of mechanical bowel preparation (MBP) on the intracellular environment, specifically evaluating butyrate transport, within the colon of the Sprague-Dawley rat. METHODS: Sixty-eight Sprague-Dawley rats were randomized to either an MBP group (n = 34) or a control group (n = 34). Twenty-four hours after the completion of the MBP, both groups were euthanized, and the colons were harvested. The level of cellular apoptosis was investigated after DNA fragmentation, poly(ADP-ribose) polymerase cleavage, and caspase assays. Western blot analysis was performed to measure the expression of the butyrate transporter protein, monocarboxylate transporters 1, and proliferating cell nuclear antigen (a marker for tissue proliferation). Immunohistochemical staining was performed to further investigate cellular proliferation. Statistical significance (P < 0.05) was determined using two-tailed t-test. RESULTS: Apoptosis was detected without significant differences in both groups. Western Blot analysis demonstrated that the expression of the monocarboxylate transporters 1 protein is downregulated in the MBP group (10.18 ± 3.09) compared with the control group (16.73 ± 7.39, P = 0.001), and proliferating cell nuclear antigen levels showed a decrease in cellular proliferation in the MBP group (13.35 ± 5.88) compared with the control (20.07 ± 7.55, P = 0.018). Immunohistochemistry confirmed a decrease in cellular proliferation after MBP with 23.4 ± 7.8% of the cells staining positive for Ki-67 in the MBP group versus 28.6 ± 7.9% in the control group (P = 0.006). CONCLUSIONS: MBP has a negative impact on cellular proliferation and intracellular transport of butyrate within the rat colon, not related to apoptosis. This is the first study to demonstrate the intracellular effects that MBP has on the rat colon.

Isotopic and Geochemical Tracers for U(VI) Reduction and U Mobility at an in Situ Recovery U Mine.

In situ recovery (ISR) uranium (U) mining mobilizes U in its oxidized hexavalent form (U(VI)) by oxidative dissolution of U from the roll-front U deposits. Postmining natural attenuation of residual U(VI) at ISR mines is a potential remediation strategy. Detection and monitoring of naturally occurring reducing subsurface environments are important for successful implementation of this remediation scheme. We used the isotopic tracers (238)U/(235)U (δ(238)U), (234)U/(238)U activity ratio, and (34)S/(32)S (δ(34)S), and geochemical measurements of U ore and groundwater collected from 32 wells located within, upgradient, and downgradient of a roll-front U deposit to detect U(VI) reduction and U mobility at an ISR mining site at Rosita, TX, USA. The δ(238)U in Rosita groundwater varies from +0.61‰ to -2.49‰, with a trend toward lower δ(238)U in downgradient wells. The concurrent decrease in U(VI) concentration and δ(238)U with an ε of 0.48‰ ± 0.08‰ is indicative of naturally occurring reducing environments conducive to U(VI) reduction. Additionally, characteristic (234)U/(238)U activity ratio and δ(34)S values may also be used to trace the mobility of the ore zone groundwater after mining has ended. These results support the use of U isotope-based detection of natural attenuation of U(VI) at Rosita and other similar ISR mining sites.

Technical Note: Calcium and carbon stable isotope ratios as paleodietary indicators.

Calcium stable isotope ratios are hypothesized to vary as a function of trophic level. This premise raises the possibility of using calcium stable isotope ratios to study the dietary behaviors of fossil taxa and to test competing hypotheses on the adaptive origins of euprimates. To explore this concept, we measured the stable isotope composition of contemporary mammals in northern Borneo and northwestern Costa Rica, two communities with functional or phylogenetic relevance to primate origins. We found that bone collagen δ(13) C and δ(15) N values could differentiate trophic levels in each assemblage, a result that justifies the use of these systems to test the predicted inverse relationship between bioapatite δ(13) C and δ(44) Ca values. As expected, taxonomic carnivores (felids) showed a combination of high δ(13) C and low δ(44) Ca values; however, the δ(44) Ca values of other faunivores were indistinguishable from those of primary consumers. We suggest that the trophic insensitivity of most bioapatite δ(44) Ca values is attributable to the negligible calcium content of arthropod prey. Although the present results are inconclusive, the tandem analysis of δ(44) Ca and δ(13) C values in fossils continues to hold promise for informing paleodietary studies and we highlight this potential by drawing attention to the stable isotope composition of the Early Eocene primate Cantius.

Strengthening Military Medical Provider Readiness: A Comprehensive Examination of VHA-MHS Partnerships.

Military medical readiness, particularly in surgical specialties, remains a significant concern within the Military Health System (MHS). While initiatives like the U.S. Army Military-Civilian Trauma Team (AMCT3) Program have addressed some readiness gaps, they primarily focus on trauma care, leaving other crucial medical specialties underserved. Leveraging partnerships between the Department of Veterans Affairs (VA) and the Defense Health Agency (DHA) emerges as a strategic approach to address these challenges comprehensively. Further collaboration between the VA and MHS is an opportunity to enhance military medical provider readiness, covering expanded medical specialties and health care personnel. By utilizing resource-sharing agreements (RSAs) and the Joint Incentive Fund (JIF), opportunities for increased collaboration and interoperability between the VA and MHS are explored. Challenges such as maintaining partnerships, addressing billing issues, and navigating local-level politics are identified, with proposed solutions, including establishing a centralized interagency office to monitor and manage specialty care partnerships. A comprehensive approach to enhancing military medical provider readiness through VA-MHS partnerships is crucial. By addressing readiness gaps and optimizing resource utilization, such collaboration would likely improve the overall readiness of the medical force, benefiting both military and veteran patient populations.

Colorectal Oncologic Emergencies: Recognition, Management, and Outcomes.

Colorectal cancer is the third most frequent type of malignancy in the United States, and the age at diagnosis is decreasing. Although the goal of screening is focused on prevention and early detection, a subset of patients inevitably presents as oncologic emergencies. Approximately 15% of patients with colorectal cancer will present as surgical emergencies, with the majority being due to either colonic perforation or obstruction. Patients presenting with colorectal emergencies are a challenging cohort, as they often present at an advanced stage with an increase in T stage, lymphovascular invasion, and metachronous liver disease.

Developing the Ready Military Medical Force: military-specific training in Graduate Medical Education.

Introduction: Graduate Medical Education plays a critical role in training the next generation of military physicians, ensuring they are ready to uphold the dual professional requirements inherent to being both a military officer and a military physician. This involves executing the operational duties as a commissioned leader while also providing exceptional medical care in austere environments and in harm's way. The purpose of this study is to review prior efforts at developing and implementing military unique curricula (MUC) in residency training programs. Methods: We performed a literature search in PubMed (MEDLINE), Embase, Web of Science, and the Defense Technical Information Center through August 8, 2023, including terms "graduate medical education" and "military." We included articles if they specifically addressed military curricula in residency with terms including "residency and operational" or "readiness training", "military program", or "military curriculum". Results: We identified 1455 articles based on title and abstract initially and fully reviewed 111. We determined that 64 articles met our inclusion criteria by describing the history or context of MUC, surveys supporting MUC, or military programs or curricula incorporated into residency training or military-specific residency programs. Conclusion: We found that although there have been multiple attempts at establishing MUC across training programs, it is difficult to create a uniform curriculum that can be implemented to train residents to a single standard across services and specialties.

Case Volume and Readiness to Deploy: Clinical Opportunities for Active-Duty Surgeons Outside of Military Hospitals.

BACKGROUND: The Military Health System (MHS) uses a readiness program that identifies the knowledge, skills, and abilities (KSAs) necessary for surgeons to provide combat casualty care. Operative productivity is assigned an objective score based on case type and complexity and totaled to assess overall readiness. As of 2019, only 10.1% of surgeons met goal readiness threshold. At one tertiary military treatment facility (MTF), leadership has taken an aggressive approach toward increasing readiness by forming military training agreements (MTAs) and allowing Off Duty Employment (ODE). We sought to quantify the efficacy of this approach. STUDY DESIGN: Operative logs from 2021 were obtained from surgeons assigned to the MTF. Operations were assigned CPT codes and processed through the KSA calculator (Deloitte; London, UK). Each surgeon was then surveyed to identify time away from clinical duties for deployment or military training. RESULTS: Nine surgeons were present in 2021 and spent an average of 10.1 weeks (19.5%) abroad. Surgeons performed 2,348 operations (Average [Avg] 261 ± 95) including 1,575 (Avg 175; 67.1%) at the MTF, 606 (Avg 67.3; 25.8%) at MTAs, and 167 (Avg 18.6, 7.1%) during ODE. Adding MTA and ODE caseloads increased KSA scores by 56% (17,765 ± 7,889 vs 11,391 ± 8,355). Using the MHS threshold of 14,000, 3 of 9 (33.3%) surgeons met the readiness threshold from MTF productivity alone. Including all operations, 7 of 9 (77.8%) surgeons met threshold. CONCLUSIONS: Increased use of MTAs and ODE significantly augments average caseloads. These operations provide considerable benefit and result in surgeon readiness far exceeding the MHS average. Military leadership can maximize the chances of meeting readiness goals by encouraging clinical opportunities outside the MTF.

Differential isotopic fractionation during Cr(VI) reduction by an aquifer-derived bacterium under aerobic versus denitrifying conditions.

We studied Cr isotopic fractionation during Cr(VI) reduction by Pseudomonas stutzeri strain RCH2. Despite the fact that strain RCH2 reduces Cr(VI) cometabolically under both aerobic and denitrifying conditions and at similar specific rates, fractionation was markedly different under these two conditions (ε was ∼2‰ aerobically and ∼0.4‰ under denitrifying conditions).

Soft skills in a hard world: Why emergency management and business continuity leaders must update their professional toolbox.

In today's rapidly changing threat environment, especially amid the COVID-19 pandemic, the roles of emergency management (EM) and business continuity (BC) professionals are continuously evolving. Today's EM/BC professional has become more mission-critical than ever, with their position placed under a spotlight as companies of all sizes prepare themselves for the next unknown, but inevitable, crisis. A common problem, however, is that many professionals with the requisite hard skills lack a light touch when it comes to communicating the goals they are striving to achieve. This paper discusses the importance of soft skills for the crisis management guru. The paper lays out which of the multitude of soft skills are the most critical, outlining ways for EM/BC professionals to build, utilise and maintain their soft skills, with case studies that exemplify the use or misuse of such skills.

Utilizing the Army Physical Fitness Test as a Primary Outcome in Surgical Clinical Research.

Functional data as part of clinical outcomes such as Activities of Daily Living and Quality of Life (QOL) frequently depend on surveys and are thus inherently limited by self-reporting and patient subjectivity. Specifically, the 12-Item Short Form Survey (SF-12), 36-Item Short Form Survey (SF-36), and Carolinas Comfort Scale are validated instruments for assessing medical and surgical QOL outcomes. However, performance-based measures of disability are lacking. We propose the Army Physical Fitness Test (APFT) as a novel clinical measure of function following surgical intervention. We believe that studies using the APFT as a surgical outcome can potentially provide novel, relevant insights that may guide the utilization of specific surgical interventions and that the use of APFT data in surgical research will meet contemporary ethical standards.

Committee on Surgical Combat Casualty Care position statement on the use of single surgeon teams and invited commentaries.

BACKGROUND: Over the last 20 years of war, there has been an operational need for far forward surgical teams near the point of injury. Over time, the medical footprint of these teams has decreased and the utilization of mobile single surgeon teams (SSTs) by the Services has increased. The increased use of SSTs is because of a tactical mobility requirement and not because of proven noninferiority of clinical outcomes. Through an iterative process, the Committee on Surgical Combat Casualty Care (CoSCCC) reviewed the utilization of SSTs and developed an expert-opinion consensus statement addressing the risks of SST utilization and proposed mitigation strategies. METHODS: A small triservice working group of surgeons with deployment experience, to include SST deployments, developed a statement regarding the risks and benefits of SST utilization. The draft statement was reviewed by a working group at the CoSCCC meeting November 2021 and further refined. This was followed by an extensive iterative review process, which was conducted to ensure that the intended messaging was clear to senior medical leaders and operational commanders. The final draft was voted on by the entire CoSCCC membership. To inform the civilian trauma community, commentaries were solicited from civilian trauma leaders to help put this practice into context and to further the discussion in both military and civilian trauma communities. RESULTS: After multiple revisions, the SST statement was finalized in January 2022 and distributed to the CoSCCC membership for a vote. Of 42 voting members, there were three nonconcur votes. The SST statement underwent further revisions to address CoSCCC voting membership comments. Statement commentaries from the President of the American Association for the Surgery for Trauma, the chair of the Committee on Trauma, the Medical Director of the Military Health System Strategic Partnership with the American College of Surgeons and a recently retired military surgeon we included to put this military relevant statement into a civilian context and further delineate the risks and benefits of including the trauma care paradigm in the Department of Defense (DoD) deployed trauma system. CONCLUSION: The use of SSTs has a role in the operational environment; however, operational commanders must understand the tradeoff between tactical mobility and clinical capabilities. As SST tactical mobility increases, the ability of teams to care for multiple casualty incidents or provide sustained clinical operations decreases. The SST position statement is a communication tool to inform operational commanders and military medical leaders on the use of these teams on current and future battlefields.

Evaluation of intraperitoneal placement of absorbable and nonabsorbable barrier coated mesh secured with fibrin sealant in a New Zealand white rabbit model.

BACKGROUND: This study aimed to evaluate the acute and chronic fixation strength of fibrin sealant (FS) as an alternative method of fixation for laparoscopic ventral hernia repair (LVHR). METHODS: Representative mesh types for LVHR included one nonabsorbable barrier mesh (Composix) and three absorbable barrier meshes (Sepramesh, Proceed, and Parietex composite). Macroporous polypropylene mesh (Prolite Ultra) served as the control mesh. Three methods of fixation were used, namely, 0-polypropylene suture+FS (ARTISS 4 IU), FS alone (ARTISS), and tacks alone, to secure 3×4-cm pieces of mesh (10 of each combination) to the peritoneal surface of New Zealand white rabbit abdominal wall. After 2 h of incubation at 37 °C, specimens underwent acute testing. Subsequently, a chronic phase was completed using the aforementioned fixation methods (10 of each combination), in which two 4×4-cm pieces of mesh were secured intraperitoneally in each of 75 New Zealand white rabbits, which survived 8 weeks until they were sacrificed. A transparent grid overlay was used to measure the mesh and adhesion area. Adhesion tenacity was characterized using the Garrard adhesion scale. In both the acute and chronic samples, a 3×3-cm area of mesh-tissue interface underwent lap shear testing at a rate of 0.42 mm/s using a tensiometer (Instron 5542). The maximum load sustained by the mesh-tissue construct was recorded as the acute fixation strength in newtons (N). Data are given as means±standard error of the mean. Statistical significance (p<0.05) was determined using a one-way analysis of variance (ANOVA) with Fisher's least significant difference (LSD) posttest or a nonparametric Kruskal-Wallis test (adhesion scores). RESULTS: The acute fixation strength was significantly greater for all the meshes secured with either suture+FS or tacks alone than for FS alone (p<0.001 for all comparisons). All the meshes except Proceed demonstrated greater acute fixation strength with suture+FS than with tacks alone (p≤0.016). Composix achieved greater acute fixation with suture+FS than all the other meshes (p≤0.022). Acute fixation with suture + FS was greater for Parietex Composite and ProLite Ultra than for Proceed (p≤0.015). When the animals were sacrificed, 48 of 50 meshes fixed with FS alone were insufficiently affixed to the abdominal wall, which may have resulted in hernia recurrence in a hernia model. The chronic fixation strength was greater for all the mesh types with either suture+FS or tacks only than with FS alone (p≤0.0005). The chronic fixation strength was greater with suture+FS than with tacks for Proceed and ProLite Ultra (p≤0.013). Neither mesh area nor adhesion tenacity differed significantly with any mesh/fixation method combination. CONCLUSIONS: In a chronic rabbit model of LVHR, fixation strength with FS alone was inadequate for selected nonabsorbable and absorbable barrier-coated meshes. The acute and chronic fixation strengths of suture+FS were equivalent or superior to the fixation strength of tacks alone. Using a combination of suture and FS for mesh fixation in LVHR may provide adequate fixation while decreasing postoperative pain due to spiral titanium tacks. In this preclinical series, mesh secured to the peritoneal surface by FS alone may have led to early recurrence.

Collagen type I:III ratio of the gastroesophageal junction in patients with paraesophageal hernias.

BACKGROUND: The purpose of this study was to examine the biological environment of the esophageal hiatus through analysis of the collagen content within the gastrohepatic ligament (GHL), gastrophrenic ligament (GPL), and phrenoesophageal ligament (PEL) in patients with type I hiatal hernias (HH) and type III paraesophageal hernias (PEH). METHODS: A control group (N=10) and patients with type I HH (N=10) and type III PEH (N=10) were included in the analysis. Specimens of the GHL, PEL, and GPL were collected intraoperatively. Slides stained with sirius red/fast green were created and ten photos at 400×magnification were taken of each specimen. Axiovision 4.7 (Zeiss) photo analysis software was employed for quantification of collagen I (red) and III (green) by calculating color area (µm2). Statistical significance (p<0.05) was determined using a one-way ANOVA and Fisher's LSD post-test. RESULTS: Cross-polarization microscopy revealed that the collagen I content was similar in the three study groups for the GHL, greater in the type III PEH group and in the control group compared to the type I HH group for the PEL, and greater in the type III PEH group compared to control group for the GPL. Collagen III quantity was greater in the control group than in the type I HH group for each ligament, and greater in the GHL and PEL when compared to the type III PEH group. Type III PEH patients had greater collagen III quantity than did type I HH patients for each ligament. Collagen type I:III ratio of the GHL was greater in both hernia groups compared to the control group. Type III PEH patients contained a higher I:III ratio than both the control and type I HH groups with respect to the PEL. There was no difference in the ratio with evaluation of the GPL for the three groups. CONCLUSION: Evaluation of the esophageal hiatus revealed that patients with PEH have a different biological environment with regard to collagen content compared to control patients. The collagen I:III ratio of the study groups was equal to or greater than the control group. Collagen deficiency in the GE junction supporting ligaments does not appear to be an etiology of PEH formation.

Clinical outcomes of atypical extra-esophageal reflux symptoms following laparoscopic antireflux surgery.

INTRODUCTION: While it is well established that antireflux surgery is effective in relieving typical gastroesophageal reflux disease (GERD) symptoms such as heartburn and regurgitation, it is currently unclear whether atypical symptoms (cough, hoarseness, wheeze) foreshadow a less satisfactory outcome following laparoscopic antireflux surgery (LARS). The purpose of this study is to critically analyze the clinical outcomes of atypical symptoms in patients undergoing LARS. METHODS: Patients scheduled for LARS for GERD were prospectively enrolled over a 7-year period; all subjects underwent preoperative high-resolution manometry (HRM) and had evidence of GERD on ambulatory pH study. Cough, wheeze, and hoarseness were considered atypical symptoms. During preoperative and postoperative examinations, patients completed detailed foregut symptomatology questionnaires, using both 5-point Likert and 10-point visual analog scales (VAS) to document typical as well as atypical symptoms. Atypical symptom burden was calculated as a sum of VAS for the three atypical symptoms, termed the atypical score (ATS). HRM patterns were grouped into normal, spastic, and hypomotile. Statistical significance (p < 0.05) was determined using paired t-test, and analysis of variance with post hoc least significant difference (LSD). RESULTS: One hundred thirteen patients (age 49 ± 1.26 years, range 20-84 years, M:F 47:66) with mean follow-up of 28 ± 2.31 months (range 1-92 months) fulfilled inclusion criteria, having mean modified DeMeester score of 45.5 ± 2.78. Heartburn was noted in 84.1%, while atypical symptoms of some degree were reported by 92.0% (104 patients). Heartburn improved from a preoperative score of 7.1 ± 0.54 to 0.9 ± 0.24 after LARS, and ATS improved from 8.9 ± 0.71 to 2.2 ± 0.42. Significant improvements were noted for all atypical symptoms analyzed (p < 0.0001 for each). Improvement in atypical symptoms was least in the presence of hypomotility features on HRM (21.7% improvement), compared with normal motility (72.4%) and spastic features (83.9%). Preoperative atypical score (p < 0.0001) and esophageal hypomotility (p = 0.04) demonstrated a linear relationship with postoperative atypical score. CONCLUSIONS: In an unselected cohort of patients undergoing LARS, atypical GERD symptoms improved as significantly as typical symptoms. Symptom improvement was significantly lower in the presence of esophageal hypomotility and with higher symptomatic state. Therefore, patients with severe atypical symptoms or hypomotile esophagus may not achieve the same clinical satisfaction from LARS.