Postoperative bleeding after complex abdominal wall reconstruction: A post hoc analysis of a randomized clinical trial.

BACKGROUND: Abdominal wall reconstruction requires extensive dissection of the abdominal wall, exposure of the retroperitoneum, and aggressive chemoprophylaxis to reduce the risk of thromboembolic complications. The need for early anticoagulation puts patients at risk for bleeding. We aimed to quantify postoperative blood loss, incidence of transfusion and reoperation, and associated risk factors in patients undergoing complex abdominal wall reconstruction. METHODS: All patients underwent a posterior component separation with transversus abdominis release and placement of retromuscular mesh for ventral hernias <20 cm wide and were enrolled in a clinical trial assessing the utility of trans-fascial mesh fixation. A post hoc analysis was performed to quantify postoperative hemoglobin drop, blood transfusions, and procedural interventions for ongoing bleeding during the first 30 postoperative days. Multivariate logistic regression was used to identify predictors of transfusion. RESULTS: In 325 patients, hemoglobin decreased by 3.61 (±1.58) g/dL postoperatively. Transfusion incidence was 9.5% (n = 31), and 3.1% (n = 10) required a surgical intervention for bleeding. Initiation of therapeutic anticoagulation postoperatively resulted in a higher likelihood of requiring surgical intervention for bleeding (odds ratio 10.4 [95% confidence interval 2.75-43.8], P < .01). Use of perioperative therapeutic anticoagulation was associated with higher rates of transfusion (odds ratio 3.51 [95% confidence interval 1.34-8.53], P < .01). Neither intraoperative blood loss nor operative times were associated with an increased transfusion requirement or need for operative intervention. CONCLUSION: Patients undergoing transversus abdominis release are at a high risk of postoperative bleeding that can require transfusion and reoperation. Patients requiring postoperative therapeutic anticoagulation are at particularly high risk.

Long-term mesh-related complications from minimally invasive intraperitoneal onlay mesh for small to medium-sized ventral hernias.

INTRODUCTION: Intraperitoneal onlay mesh (IPOM) placement for small to medium-sized hernias has garnered negative attention due to perceived long-term risk of mesh-related complications. However, sparse data exists supporting such claims after minimally invasive (MIS) IPOM repairs and most is hindered by the lack of long-term follow-up. We sought to report long-term outcomes and mesh-related complications of MIS IPOM ventral hernia repairs. METHODS AND PROCEDURES: Adult patients who underwent MIS IPOM ventral hernia repair at our institution were identified in the Abdominal Core Health Quality Collaborative database from October 2013 to October 2020. Outcomes included hernia recurrence and mesh-related complications or reoperations up to 6 years postoperatively. RESULTS: A total of 325 patients were identified. The majority (97.2%) of cases were elective, non-recurrent (74.5%), and CDC class I (99.4%). Mean hernia width was 4.16 ± 3.86 cm. Median follow-up was 3.6 (IQR 2.8-5) years. Surgeon-entered or patient-reported follow-up was available for 253 (77.8%) patients at 3 years or greater postoperatively. One patient experienced an early small bowel obstruction and was reoperated on within 30 days. Two-hundred forty-five radiographic examinations were available up to 6 years postoperatively. Twenty-seven patients had hernia recurrence on radiographic examination up to 6 years postoperatively. During long-term follow-up, two mesh-related complications required reoperations: mesh removed for chronic pain and mesh removal at the time of colon surgery for perforated cancer. Sixteen additional patients required reoperation within 6 years for the following reasons: hernia recurrence (n = 5), unrelated intraabdominal pathology (n = 9), obstructed port site hernia (n = 1), and adhesive bowel obstruction unrelated to the prosthesis (n = 1). The rate of reoperation due to intraperitoneal mesh complications was 0.62% (2/325) with up to 6 year follow-up. CONCLUSION: Intraperitoneal mesh for repair of small to medium-sized hernias has an extremely low rate of long-term mesh-related complications. It remains a safe and durable option for hernia surgeons.

Open retromuscular keyhole compared with Sugarbaker mesh for parastomal hernia repair: Early results of a randomized clinical trial.

BACKGROUND: Open parastomal hernia repair can be performed using retromuscular synthetic mesh in a keyhole or Sugarbaker configuration. Relative morbidity and durability are unknown. Here, we present perioperative outcomes of a randomized controlled trial comparing these techniques, including 30-day patient-reported outcomes, reoperations, and wound complications in ≤90 days. METHODS: This single-center randomized clinical trial compared open parastomal hernia repair with retromuscular medium-weight polypropylene mesh in the keyhole and Sugarbaker configuration for permanent stomas between April 2019 and April 2022. Adult patients with parastomal hernias requiring open repair with sufficient bowel length for either technique were included. Patient-reported outcomes were collected at 30 days; 90-day outcomes included initial hospital length of stay, readmission, wound morbidity, reoperation, and mesh- or stoma-related complications. RESULTS: A total of 150 patients were randomized (75 keyhole and 75 Sugarbaker). There were no differences in length of stay, readmission, reoperation, recurrence, or wound complications. Twenty-four patients (16%) required procedural intervention for wound morbidity. Ten patients (6.7%) required abdominal reoperation in ≤90 days, 7 (4.7%) for wound morbidity, including 3 partial mesh excisions (1 keyhole compared with 2 Sugarbaker; P = 1). Four mesh-related stoma complications requiring reoperations occurred, including stoma necrosis (n = 1), bowel obstruction (n = 1), parastomal recurrence (n = 1), and mucocutaneous separation (n = 1), all in the Sugarbaker arm (P = .12). Patient-reported outcomes were similar between groups at 30 days. CONCLUSION: Open parastomal hernia repair with retromuscular mesh in the keyhole and Sugarbaker configurations had similar perioperative outcomes. Patients will be followed to determine long-term relative durability, which is critical to understanding each approach's risk-benefit ratio.

Evaluating the impact of lifting mandatory smoking cessation prior to elective abdominal wall reconstruction. A single-center experience.

INTRODUCTION: Many studies identify active smoking as a significant risk factor for postoperative wound and mesh complications in patients undergoing abdominal wall reconstruction surgery. However, our group conducted an analysis using data from the ACHQC database, which revealed similar rates of surgical site infection (SSI) and surgical site occurrence requiring procedural intervention (SSOPI) between active smokers and non-smokers As a result, the Cl eveland Clinic Center for Abdominal Core Health instituted a policy change where active smokers were no longer subject to surgical delay. Our study aims to evaluate the impact of active smoking on the outcomes of these patients. METHODS: We identified active smoking patients who had undergone open, elective, clean ventral hernia repair (VHR) with transversus abdominis release (TAR) and permanent synthetic mesh at Cleveland Clinic Foundation. Propensity matching was performed to create a 1:3 ratio of "current-smokers" and "never-smokers" and compared wound complications and all 30-day morbidity between the two groups. RESULTS: 106 current-smokers and 304 never-smokers were matched. Demographics were similar between the two groups after matching, with the exception of chronic obstructive pulmonary disease (COPD) (22.1% vs. 13.4%, p â€‹< â€‹.001) and body mass index (BMI) (31.1 vs. 32.6, p â€‹= â€‹.02). Rates of SSI (12.2% vs. 6.9%, p â€‹= â€‹.13), SSO (21.7% vs. 13.2%, p â€‹= â€‹.052), SSOPI (11.3% vs. 6.3%, p â€‹= â€‹.13), and reoperation (1.9% vs. 3.9%, p â€‹= â€‹.53) were not significantly different between active smokers and never-smokers correspondingly. One case (0.3%) of partial mesh excision was observed in the never-smokers group (p â€‹= â€‹1). The current-smokers group exhibited a significantly higher incidence of pneumonia compared to the never-smokers group (5.7% vs. 0.7%, p â€‹= â€‹.005). CONCLUSION: Our study revealed that operating on active smokers did result in a slight increase in wound morbidity, although it did not reach statistical significance. Additionally, pulmonary complications were higher in the smoking group. Notably, we did not see any mesh infections in the smoking group during early follow up. We believe that this data is important for shared decision making on patients that are actively smoking contemplating elective hernia repair.

Tipping the scale in abdominal wall reconstruction: An analysis of short- and long-term outcomes by body mass index.

BACKGROUND: Morbid obesity, with a body mass index 35 kg/m2, is a commonly used cutoff for denying elective transversus abdominis release. Although obesity is linked to short-term wound morbidity, its effect on long-term outcomes remains unknown, calling into question if a cutoff is justified. We sought to compare 1-year recurrence rates after transversus abdominis release based on body mass index and to evaluate short- and long-term outcomes. METHODS: Patients undergoing open, clean transversus abdominis release from August 2014 to January 2022 at our institution with 1-year follow-up completed were identified. Univariate and multivariable analyses were performed to determine the association of body mass index with 90-day wound events, 1-year hernia recurrence, and hernia-specific quality of life. Covariates included body mass index, diabetes, recurrent hernia, hernia width, fascial closure, surgical site occurrence requiring procedural intervention, previous abdominal wall surgical site infection, inflammatory bowel disease, mesh weight, and mesh-to-hernia size ratio. RESULTS: A total of 1,089 patients were included. Increasing body mass index was associated with surgical site infection (adjusted odds ratio = 1.59; 95% confidence interval, 1.14-1.77; P < .01) and surgical site occurrence (adjusted odds ratio = 1.42; 95% confidence interval, 1.13-1.74; P < .01) but was not associated with surgical site occurrence requiring procedural intervention. Hernia width was associated with surgical site occurrence (adjusted odds ratio = 1.4; 95% confidence interval, 1.08-1.82; P < .01) and surgical site occurrence requiring procedural intervention (adjusted odds ratio = 1.4; 95% confidence interval, 1.08-1.82; P = .01). Hernia recurrence rate at 1 year was lower for the body mass index ≥35 kg/m2 group (7% vs 12%; P = .02). Hernia width (odds ratio = 1.33; 95% confidence interval, 1.02-1.74; P = .04) was associated with recurrence; body mass index was not (P = .11). Both groups experienced significant improvement in hernia-specific quality of life at 1 year. CONCLUSION: Morbid obesity is associated with 90-day wound morbidity; however, short-term complications did not translate to higher reoperation or long-term recurrence rates. The impact of body mass index on hernia recurrence is likely overstated. An arbitrary body mass index cutoff of 35 kg/m2 should not be used to deny symptomatic patients abdominal wall reconstruction.

Revisiting femoral hernia diagnosis rates by patient sex in inguinal hernia repairs.

INTRODUCTION: Guidelines recommend MIS repairs for females with inguinal hernias, despite limited evidence. We investigated rates of femoral hernias intraoperatively noted during MIS and Lichtenstein repairs in females. METHODS: ACHQC was queried for adult females undergoing inguinal hernia repair between January 2014-November 2022. Outcomes included identified femoral hernia and size, hernia recurrence, quality of life, and sex-based recurrence. RESULTS: 1357 and 316 females underwent MIS and Lichtenstein inguinal repair respectively. Femoral hernias were identified more frequently in MIS than open repairs (27%vs12%; (p â€‹< â€‹0.001). Most femoral hernias in MIS (61%) and Lichtenstein repairs (62%) were <1.5 â€‹cm(p â€‹< â€‹0.001). Identification rates of femoral hernias >3 â€‹cm were 1% overall(p â€‹= â€‹0.09). Surgeon and patient-reported recurrences were similar between approaches at 1-5-years for females(p â€‹> â€‹0.05 for all) and similar between sexes(p â€‹> â€‹0.05). CONCLUSION: Most incidental femoral hernias are small and both repair approaches demonstrated similar outcomes. The recommendation for MIS inguinal hernia repairs in females is potentially overstated.

Quantitative Tension on the Abdominal Wall in Posterior Components Separation With Transversus Abdominis Release.

Importance: Posterior components separation (PCS) is a commonly used myofascial release technique in ventral hernia repairs. The contribution of each release with anterior and posterior fascial advancement has not yet been characterized in patients with ventral hernias. Objective: To quantitatively assess the changes in tension on the anterior and posterior fascial elements of the abdominal wall during PCS to inform surgeons regarding the technical contribution of each step with those changes, which may help to guide intraoperative decision-making. Design, Setting, and Participants: This case series enrolled patients from December 2, 2021, to August 2, 2022, and was conducted at the Cleveland Clinic Center for Abdominal Core Health. The participants included adult patients with European Hernia Society classification M1 to M5 ventral hernias undergoing abdominal wall reconstruction with PCS. Intervention: A proprietary, sterilizable tensiometer measured the force needed to bring the fascial edge of the abdominal wall to the midline after each step of a PCS (retrorectus dissection, division of the posterior lamella of the internal oblique aponeurosis, and transversus abdominis muscle release [TAR]). Main Outcome: The primary study outcome was the percentage change in tension on the anterior and posterior fascia associated with each step of PCS with TAR. Results: The study included 100 patients (median [IQR] age, 60 [54-68] years; 52 [52%] male). The median (IQR) hernia width was 13.0 (10.0-15.2) cm. After complete PCS, the mean (SD) percentage changes in tension on the anterior and posterior fascia were -53.27% (0.53%) and -98.47% (0.08%), respectively. Of the total change in anterior fascial tension, retrorectus dissection was associated with a mean (SD) percentage change of -82.56% (0.68%), incision of the posterior lamella of the internal oblique with a change of -17.67% (0.41%), and TAR with no change. Of the total change in posterior fascial tension, retrorectus dissection was associated with a mean (SD) percentage change of -3.04% (2.42%), incision of the posterior lamella of the internal oblique with a change of -58.78% (0.39%), and TAR with a change of -38.17% (0.39%). Conclusions and Relevance: In this case series, retrorectus dissection but not TAR was associated with reduced tension on the anterior fascia, suggesting that it should be performed if anterior fascial advancement is needed. Dividing the posterior lamella of the internal oblique aponeurosis and TAR was associated with reduced tension on the posterior fascia, suggesting that it should be performed for posterior fascial advancement.

Distressed community index as a predictor of presentation and postoperative outcomes in ventral hernia repair.

BACKGROUND: We evaluated the impact of socioeconomic status on presentation, management, and outcomes of ventral hernias. METHODS: The Abdominal Core Health Quality Collaborative was queried for adult patients undergoing ventral hernia repair. Socioeconomic quintiles were assigned using the Distressed Community Index (DCI): prosperous (0-20), comfortable (21-40), mid-tier (41-60), at-risk (61-80), and distressed (81-100). Outcomes included presenting symptoms, urgency, operative details, 30-day outcomes, and one-year hernia recurrence rates. Multivariable regression evaluated 30-day wound complications. RESULTS: 39,494 subjects were identified; 32,471 had zip codes (82.2%).Urgent presentation (3.6% vs. 2.3%) and contaminated cases (0.83% vs. 2.06%) were more common in the distressed group compared to the prosperous group (p < 0.001). Higher DCI correlated with readmission (distressed: 4.7% vs prosperous: 2.9%,p < 0.001) and reoperation (distressed 1.8% vs prosperous: 0.92%,p < 0.001). Wound complications were independently associated with increasing DCI (p < 0.05). Clinical recurrence rates were similar at one-year (distressed: 10.4% vs prosperous: 8.6%, p = 0.54). CONCLUSIONS: Inequity exists in presentation and perioperative outcomes for ventral hernia repair and efforts should be focused on increasing access to elective surgery and improving postoperative wound care.

Transfascial Fixation vs No Fixation for Open Retromuscular Ventral Hernia Repairs: A Randomized Clinical Trial.

Importance: Transfascial (TF) mesh fixation in open retromuscular ventral hernia repair (RVHR) has been advocated to reduce hernia recurrence. However, TF sutures may cause increased pain, and, to date, the purported advantages have never been objectively measured. Objective: To determine whether abandonment of TF mesh fixation would result in a noninferior hernia recurrence rate at 1 year compared with TF mesh fixation in open RVHR. Design, Setting, and Participants: In this prospective, registry-based, double-blinded, noninferiority, parallel-group, randomized clinical trial, a total of 325 patients with a ventral hernia defect width of 20 cm or less with fascial closure were enrolled at a single center from November 29, 2019, to September 24, 2021. Follow-up was completed December 18, 2022. Interventions: Eligible patients were randomized to mesh fixation with percutaneous TF sutures or no mesh fixation with sham incisions. Main Outcome and Measures: The primary outcome was to determine whether no TF suture fixation was noninferior to TF suture fixation for open RVHR with regard to recurrence at 1 year. A 10% noninferior margin was set. The secondary outcomes were postoperative pain and quality of life. Results: A total of 325 adults (185 women [56.9%]; median age, 59 [IQR, 50-67] years) with similar baseline characteristics were randomized; 269 patients (82.8%) were followed up at 1 year. Median hernia width was similar in the TF fixation and no fixation groups (15.0 [IQR, 12.0-17.0] cm for both). Hernia recurrence rates at 1 year were similar between the groups (TF fixation, 12 of 162 [7.4%]; no fixation, 15 of 163 [9.2%]; P = .70). Recurrence-adjusted risk difference was found to be -0.02 (95% CI, -0.07 to 0.04). There were no differences in immediate postoperative pain or quality of life. Conclusions and Relevance: The absence of TF suture fixation was noninferior to TF suture fixation for open RVHR with synthetic mesh. Transfascial fixation for open RVRH can be safely abandoned in this population. Trial Registration: ClinicalTrials.gov Identifier: NCT03938688.

Laparoscopic versus robotic inguinal hernia repair: 1- and 2-year outcomes from the RIVAL trial.

INTRODUCTION: Robotic inguinal hernia repair is growing in popularity among general surgeons despite little high-quality evidence supporting short- or long-term advantages over traditional laparoscopic inguinal hernia repair. The original RIVAL trial showed increased operative time, cost, and surgeon frustration for the robotic approach without advantages over laparoscopy. Here we report the 1- and 2-year outcomes of the trial. METHODS: This is a multi-center, patient-blinded, randomized clinical study conducted at six sites from 2016 to 2019, comparing laparoscopic versus robotic transabdominal preperitoneal (TAPP) inguinal hernia repair with follow-up at 1 and 2 years. Outcomes include pain (visual analog scale), neuropathic pain (Leeds assessment of neuropathic symptoms and signs pain scale), wound morbidity, composite hernia recurrence (patient-reported and clinical exam), health-related quality of life (36-item short-form health survey), and physical activity (physical activity assessment tool). RESULTS: Early trial participation included 102 patients; 83 (81%) completed 1-year follow-up (45 laparoscopic vs. 38 robotic) and 77 (75%) completed 2-year follow-up (43 laparoscopic vs. 34 robotic). At 1 and 2 years, pain was similar for both groups. No patients in either treatment arm experienced neuropathic pain. Health-related quality of life and physical activity were similar for both groups at 1 and 2 years. No long-term wound morbidity was seen for either repair type. At 2 years, there was no difference in hernia recurrence (1 laparoscopic vs. 1 robotic; P = 1.0). CONCLUSIONS: Laparoscopic and robotic inguinal hernia repairs have similar long-term outcomes when performed by surgeons with experience in minimally invasive inguinal hernia repairs.

Frequency and Risk Factors of Maxillary Sinusitis of Endodontic Origin Evaluated by a Dynamic Navigation and a New Filter of Cone-Beam Computed Tomography.

INTRODUCTION: The aim of this study was to determine the frequency and risk factors of maxillary sinusitis of endodontic origin (MSEO) on posterior maxillary teeth evaluated using dynamic navigation and a novel filter of cone-beam computed tomographic (CBCT) imaging. METHODS: CBCT scans of 453 patients (814 teeth) were selected. Data were divided into 4 groups: (1) root canal treatment (RCT), (2) relation of the root apex to the maxillary sinus, (3) apical periodontitis (AP), and (4) maxillary sinus inflammation (no inflammation, periapical osteoperiostitis, periapical mucositis, partial obstruction, or total obstruction). Frequency distribution and cross-tabulation were used for data analysis. The association of maxillary sinus abnormalities with other variables was analyzed using the chi-square test. The significance level was set at 5%, and the association between dependent and independent variables was analyzed using robust Poisson regression models. RESULTS: MSEO was found in 65.6% of the cases, and the highest frequency rates were in the periapical mucositis (44%) and partial obstruction (15.8%) groups. The rates of risk factors were highest in the cases of RCT (54.9%), AP (34.3%), and the root apex in contact with the maxillary sinus (53.8%). The most frequent sex and age group were female (55.8%) and 41-50 years (30.5%). CONCLUSIONS: The frequency of MSEO was high and positively associated with RCT, AP, and the root apex's position in contact with the floor of the maxillary sinus. The maxillary sinus filter of the CBCT software provides a clear image of maxillary sinus abnormalities.

Biologic vs Synthetic Mesh for Parastomal Hernia Repair: Post Hoc Analysis of a Multicenter Randomized Controlled Trial.

BACKGROUND: Parastomal hernias are often repaired with mesh to reduce recurrences, but the presence of an ostomy increases the wound class from clean to clean-contaminated/contaminated and makes the choice of mesh more controversial than in a strictly clean case. We aimed to compare the outcomes of biologic and synthetic mesh for parastomal hernia repair. STUDY DESIGN: This is a post hoc analysis of parastomal hernia repairs in a randomized trial comparing biologic and synthetic mesh in contaminated ventral hernia repairs. Outcomes included rates of surgical site occurrences requiring procedural intervention (SSOPI), reoperations, stoma/mesh-related adverse events, parastomal hernia recurrence rates (clinical, patient-reported, and radiographic) at 2 years, quality of life (EQ-5D, EQ-5D Visual Analog Scale, and Hernia-Related Quality of Life Survey), and hospital costs up to 30 days. RESULTS: A total of 108 patients underwent parastomal hernia repair (57 biologic [53%] and 51 synthetic [47%]). Demographic and hernia characteristics were similar between the two groups. No significant differences in SSOPI rates or reoperations were observed between mesh types. Four mesh erosions into an ostomy requiring reoperations (2 biologic vs 2 synthetic) occurred. At 2 years, parastomal hernia recurrence rates were similar for biologic and synthetic mesh (17 [29.8%] vs 13 [25.5%], respectively; p = .77). Overall and hernia-related quality of life improved from baseline and were similar between the two groups at 2 years. Median total hospital cost and median mesh cost were higher for biologic compared with synthetic mesh. CONCLUSION: Biologic and synthetic mesh have similar wound morbidity, reoperations, 2-year hernia recurrence rates, and quality of life in parastomal hernia repairs. Cost should be considered in mesh choice for parastomal hernia repairs.

Comparing Sugarbaker versus keyhole mesh technique for open retromuscular parastomal hernia repair: study protocol for a registry-based randomized controlled trial.

BACKGROUND: Parastomal hernia, common after stoma creation, negatively impacts patient quality of life. For patients with a permanent stoma, durable parastomal hernia repair remains a challenge, with few high-quality studies for guidance. An alternative to open retromuscular parastomal hernia repair with retromuscular "keyhole" mesh is the recent Sugarbaker modification. We aim to compare these two techniques in a head-to-head prospective study. METHODS: This is a registry-based randomized controlled trial designed to investigate whether the retromuscular Sugarbaker technique is superior to the retromuscular keyhole technique for parastomal hernia repair. The primary study endpoint is parastomal hernia recurrence at 2 years. Secondary endpoints include hospital length-of-stay, readmission, wound morbidity, mesh-related complications, re-operation, all 30-day morbidity, and patient-reported outcomes, including hernia-related quality of life, stoma-specific quality of life, pain, and decision regret. DISCUSSION: Based on the post hoc analysis of a recent randomized controlled trial, we hypothesize that the retromuscular Sugarbaker technique will reduce parastomal hernia recurrence by 20% at 2 years compared to the retromuscular keyhole mesh technique. The results of this study may provide evidence-based guidance for surgeons repairing parastomal hernias. TRIAL REGISTRATION: ClinicalTrials.gov NCT03972553. Registered on 3 June 2019.

Apical Foramen Position in Relation to Proximal Root Surfaces of Human Permanent Teeth Determined by Using a New Cone-beam Computed Tomographic Software.

INTRODUCTION: The purpose of this study was to determine the position of the apical foramen (AF) in relation to root surfaces of human permanent teeth using cone-beam computed tomographic (CBCT) imaging and novel advanced imaging analysis software (e-Vol DX; CDT Software, Bauru, SP, Brazil). METHODS: The AF position was determined on CBCT scans viewed and analyzed using e-Vol DX of 1400 teeth (422 patients) according to the root surface as follows: buccal, mesiobuccal, mesial, mesiolingual/palatal, lingual/palatal, distolingual/palatal, distal, distobuccal, and central. Categoric variables were described as frequencies and percentages. Frequencies were reported with their confidence intervals (95%). Categoric variables were analyzed using the chi-square test with Yates correction. The level of significance was set at α = 0.05. RESULTS: The most frequent AF position in maxillary anterior teeth was central (46%-60%). The AF in mandibular central incisors was buccal in 44% of the cases. In maxillary first and second premolars, 39.98% and 42.56% of all AFs were central. In maxillary first and second molars, 46.12% and 57.49% of all AFs were central. The most frequent AF position in mandibular first and second premolars was central (42.85% and 50.98%). In mandibular first molars, 48.72% of all AFs were central. CONCLUSIONS: The AF position in human permanent teeth was central in 48.95% and 42.08% of the maxillary and mandibular teeth. CBCT images analyzed by e-Vol DX can be used to determine the true anatomic position of the AF and can be a useful tool for the treatment planning of nonsurgical and surgical endodontic treatments.

Comparative Cytogenetics of Omophoita abbreviata and O. aequinoctialis (Coleoptera, Chrysomelidae, Alticini) from the Adolpho Ducke Forest Reserve in Brazilian Amazonia: Intrapopulation Variation in Karyotypes.

The chromosomes of 2 flea beetle species from central Amazonia, Omophoita abbreviata and O. aequinoctialis (Alticini), were investigated through analysis of meiotic and mitotic cells. These species belong to the subtribe Oedionychina, a taxon that has unique cytogenetic features, such as giant sex chromosomes which are aligned at a distance during meiosis I (asynaptic). O. abbreviata and O. aequinoctialis have a meiotic formula of 10II + X + y, which is predominant in this subtribe. While the species of the genus Omophoita possess a relatively stable karyotype, a typical feature for Oedionychina, the present study identified inter- and intrapopulational variation in chromosome morphology, constitutive heterochromatin, and the presence and number of B chromosomes in O. aequinoctialis. In addition, FISH mapping of telomeric sequences revealed signals in the collochores, raising several questions on the chromosomal evolution in this group.

Independent and interactive effects of incremental heat strain, orthostatic stress, and mild hypohydration on cerebral perfusion.

The purpose of this study was to identify the dose-dependent effects of heat strain and orthostasis [via lower body negative pressure (LBNP)], with and without mild hypohydration, on systemic function and cerebral perfusion. Eleven men (means ± SD: 27 ± 7 y; body mass 77 ± 6 kg), resting supine in a water-perfused suit, underwent progressive passive heating [0.5°C increments in core temperature (Tc; esophageal to +2.0°C)] while euhydrated (EUH) or hypohydrated (HYPO; 1.5-2% body mass deficit). At each thermal state, mean cerebral artery blood velocity (MCAvmean; transcranial Doppler), partial pressure of end-tidal carbon dioxide ([Formula: see text]), heart rate (HR) and mean arterial blood pressure (MAP; photoplethysmography) were measured continuously during LBNP (0, -15, -30, and -45 mmHg). Four subjects became intolerant before +2.0°C Tc, unrelated to hydration status. Without LBNP, decreases in [Formula: see text] accounted fully for reductions in MCAvmean across all Tc. With LBNP at heat tolerance (+1.5 or +2.0°C), [Formula: see text] accounted for 69 ± 25% of the change in MCAvmean. The HYPO condition did not affect MCAvmean or any cardiovascular variables during combined LBNP and passive heat stress (all P > 0.13). These findings indicate that hypocapnia accounted fully for the reduction in MCAvmean when passively heat stressed in the absence of LBNP and for two- thirds of the reduction when at heat tolerance combined with LBNP. Furthermore, when elevations in Tc are matched, mild hypohydration does not influence cerebrovascular or cardiovascular responses to LBNP, even when stressed by a combination of hyperthermia and LBNP.

Intervention to reduce heat stress and improve efficiency among sugarcane workers in El Salvador: Phase 1.

BACKGROUND: Chronic heat stress and dehydration from strenuous work in hot environments is considered an essential component of the epidemic of chronic kidney disease in Central America. OBJECTIVE: (1) To assess feasibility of providing an intervention modelled on OSHA's Water.Rest.Shade programme (WRS) during sugarcane cutting and (2) to prevent heat stress and dehydration without decreasing productivity. METHODS: Midway through the 6-month harvest, the intervention introduced WRS practices. A 60-person cutting group was provided water supplied in individual backpacks, mobile shaded rest areas and scheduled rest periods. Ergonomically improved machetes and efficiency strategies were also implemented. Health data (anthropometric, blood, urine, questionnaires) were collected preharvest, preintervention, mid-intervention and at the end of harvest. A subsample participated in focus group discussions. Daily wet bulb globe temperatures (WBGT) were recorded. The employer provided individual production records. RESULTS: Over the harvest WBGT was >26°C from 9:00 onwards reaching average maximum of 29.3±1.7°C, around 13:00. Postintervention self-reported water consumption increased 25%. Symptoms associated with heat stress and with dehydration decreased. Individual daily production increased from 5.1 to a high of 7.3 tons/person/day postintervention. This increase was greater than in other cutting groups at the company. Focus groups reported a positive perception of components of the WRS, and the new machete and cutting programmes. CONCLUSIONS: A WRS intervention is feasible in sugarcane fields, and appears to markedly reduce the impact of the heat stress conditions for the workforce. With proper attention to work practices, production can be maintained with less impact on worker health.

Active and passive heat stress similarly compromise tolerance to a simulated hemorrhagic challenge.

Passive heat stress increases core and skin temperatures and reduces tolerance to simulated hemorrhage (lower body negative pressure; LBNP). We tested whether exercise-induced heat stress reduces LBNP tolerance to a greater extent relative to passive heat stress, when skin and core temperatures are similar. Eight participants (6 males, 32 ± 7 yr, 176 ± 8 cm, 77.0 ± 9.8 kg) underwent LBNP to presyncope on three separate and randomized occasions: 1) passive heat stress, 2) exercise in a hot environment (40°C) where skin temperature was moderate (36°C, active 36), and 3) exercise in a hot environment (40°C) where skin temperature was matched relative to that achieved during passive heat stress (∼38°C, active 38). LBNP tolerance was quantified using the cumulative stress index (CSI). Before LBNP, increases in core temperature from baseline were not different between trials (1.18 ± 0.20°C; P > 0.05). Also before LBNP, mean skin temperature was similar between passive heat stress (38.2 ± 0.5°C) and active 38 (38.2 ± 0.8°C; P = 0.90) trials, whereas it was reduced in the active 36 trial (36.6 ± 0.5°C; P ≤ 0.05 compared with passive heat stress and active 38). LBNP tolerance was not different between passive heat stress and active 38 trials (383 ± 223 and 322 ± 178 CSI, respectively; P = 0.12), but both were similarly reduced relative to active 36 (516 ± 147 CSI, both P ≤ 0.05). LBNP tolerance is not different between heat stresses induced either passively or by exercise in a hot environment when skin temperatures are similarly elevated. However, LBNP tolerance is influenced by the magnitude of the elevation in skin temperature following exercise induced heat stress.

Compression garments do not alter cerebrovascular responses to orthostatic stress after mild passive heating.

Whole-body heating increases the likelihood of syncope, whereas utilizing lower-body compression garments may reduce syncope risk. We hypothesized that graded compression garments would reduce the typically observed large postural reductions in arterial blood pressure and middle cerebral artery velocity, in normothermia and especially once passively heat stressed. Fifteen men (age: 27 ± 4 years, aerobic fitness range: 30-75 mL/kg(/) min) completed a supine-to-stand orthostatic challenge for 3 min at normothermia and after passive heating (esophageal temperature, +0.5 °C from baseline) on two occasions (> 7 days): once wearing commercially available compression trousers and once wearing low-compression placebo trousers (randomized order). Blood flow velocity in the middle cerebral artery (transcranial Doppler), mean arterial blood pressure (mean BP: Finometer) and end-tidal carbon dioxide pressure were measured continuously. During normothermia, compression, garments did not alter the magnitude of the postural changes in mean BP or middle cerebral artery velocity. After passive heating, although the magnitudes of these changes were exaggerated, they were not significantly affected by compression garments. Compression garments did not attenuate the initial or sustained orthostatic hypotension associated with posture change, either during normothermia or following passive heat stress.