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1.
Artigo em Inglês | MEDLINE | ID: mdl-38727556

RESUMO

Introduction: Hiatal hernia (HH) is a common disorder of the upper gastrointestinal (UGI) tract that general surgeons encounter. Giant paraesophageal is a subtype of HH in which more than 30% of the stomach is located in the chest. It can cause symptoms such as dysphagia, UGI bleeding, gastroesophageal reflux disease, and vomiting. As the life expectancy of the general population increases, the incidence of giant HH increases and can cause morbidity, including recurrent admissions and prolonged length of hospitalization. In this article, we describe a cohort of nonagenarian patients with HH who were admitted to our institution and were treated either surgically or medically. Methods: We retrospectively reviewed our prospectively maintained database of all nonagenarians who were admitted to our center between 2018 and 2022 with the diagnosis of HH. We compared the demographic data, clinical data, and outcomes between patients undergoing operative and nonoperative management. Results: Twenty patients of age over 90 years were hospitalized with HH-related symptoms. Six underwent surgery, whereas 14 received medical management. Surgical patients had fewer overall hospitalization days, shorter length of stay, and less blood product requirements. Notably two cases of in-hospital mortality occurred in the nonoperative group, whereas none occurred in the operative group. All surgical procedures were performed laparoscopically, with two minor perioperative complications. Conclusion: In selected nonagenarian patients, laparoscopic HH repair is safe and should be considered favorably. It can reduce hospitalization time and can mitigate morbidity.

2.
Ann Surg ; 2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38348652

RESUMO

OBJECTIVE: This study aimed to assess 30-day morbidity and mortality rates following cholecystectomy for benign gallbladder disease and identify the factors associated with complications. SUMMARY BACKGROUND DATA: Although cholecystectomy is common for benign gallbladder disease, there is a gap in the knowledge of the current practice and variations on a global level. METHODS: A prospective, international, observational collaborative cohort study of consecutive patients undergoing cholecystectomy for benign gallbladder disease from participating hospitals in 57 countries between January 1 and June 30, 2022, was performed. Univariate and multivariate logistic regression models were used to identify preoperative and operative variables associated with 30-day postoperative outcomes. RESULTS: Data of 21,706 surgical patients from 57 countries were included in the analysis. A total of 10,821 (49.9%), 4,263 (19.7%), and 6,622 (30.5%) cholecystectomies were performed in the elective, emergency, and delayed settings, respectively. Thirty-day postoperative complications were observed in 1,738 patients (8.0%), including mortality in 83 patients (0.4%). Bile leaks (Strasberg grade A) were reported in 278 (1.3%) patients and severe bile duct injuries (Strasberg grades B-E) were reported in 48 (0.2%) patients. Patient age, ASA physical status class, surgical setting, operative approach and Nassar operative difficulty grade were identified as the five predictors demonstrating the highest relative importance in predicting postoperative complications. CONCLUSION: This multinational observational collaborative cohort study presents a comprehensive report of the current practices and outcomes of cholecystectomy for benign gallbladder disease. Ongoing global collaborative evaluations and initiatives are needed to promote quality assurance and improvement in cholecystectomy.

3.
Surg Endosc ; 38(3): 1180-1190, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38082007

RESUMO

BACKGROUND: Achalasia is a rare disorder of the esophagus characterized by motor dysfunction in the esophagus and relaxation failure of the lower esophageal sphincter (LES). Currently, surgical myotomy procedures are considered the standard of care. Robotic Heller's myotomy (RHM) with fundoplication has been gaining popularity due to documented advantages in the precision of myotomy as well as avoiding the potential reflux following per-oral endoscopic myotomy (POEM). To the best of our knowledge, RHM has thus far has been performed exclusively by the da Vinci surgical system. The new Hugo RAS™ system offers a unique modular design and an open console which offers better maneuverability and docking options. In this study, we present the first worldwide series of patients undergoing RHM using the new Hugo RAS™ platform. Our objective is to propose optimal operating configuration and setup to fully harness the advantages of the unique modular design of this system. METHODS: Ten consecutive achalasia patients underwent Robotic Heller's myotomy (RHM) with the Hugo RAS™ system. We prospectively collected patient data, including demographics, comorbidities, ASA class, Eckardt scores, pre-operative manometric data, and EndoFlip parameters. Additionally, we recorded the docking and total operative times. RESULTS: Between December 2022 and August 2023, 10 patients underwent RHM with the Hugo™ RAS system. Patients had a median age of 42.5 years, 60% were female, and mean BMI was 23.2. Fifty percent had achalasia type 2 and 50% type 1. The median pre-operative integrated relaxation pressure (IRP) was 24.9. Median docking time was 10 min and overall operative time was 129.5 min. All patients, except one with acute coronary syndrome, had an uneventful peri-operative course and were discharged on post-operative day 2. CONCLUSION: The Hugo™ RAS system is well designed for robotic Heller myotomy. The operative and clinical results are similar to the currently used robotic system; however, the modular design of the system has some differences. These translate to better docking angles and maneuverability as well as console surgeon's ergonomics. Further experience is needed to explore the advantages of the system's modular design and function.


Assuntos
Acalasia Esofágica , Miotomia de Heller , Laparoscopia , Procedimentos Cirúrgicos Robóticos , Humanos , Feminino , Adulto , Masculino , Acalasia Esofágica/cirurgia , Resultado do Tratamento , Laparoscopia/métodos , Esfíncter Esofágico Inferior/cirurgia
4.
J Vasc Interv Radiol ; 35(1): 74-79, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37797738

RESUMO

PURPOSE: To evaluate the safety and effectiveness of percutaneous cholecystoenteric anastomosis (PCEA) creation in patients with indwelling cholecystostomy tubes who are high-risk surgical candidates. MATERIALS AND METHODS: Fourteen (male, 10; female, 4) patients with a mean age of 79 years (range, 53-92 years) with previously inserted cholecystostomy tubes underwent PCEA with the adjacent duodenum using a lumen-apposing metal stent (LAMS) between January 2015 and October 2022. Intraprocedural adverse events and postprocedural safety and effectiveness outcomes were evaluated. Nine procedures were performed under sedation and 5 under general anesthesia. RESULTS: Technical success was achieved in 100% of the patients. In 12 patients (86%), the existing cholecystostomy tube was removed after the insertion of the LAMS. Three patients (21%) had a pre-existing cholecystoduodenal fistula, in which the stent was placed, and 11 (79%) underwent creation of a de novo anastomosis. The mean procedure time was 1.5 hours (range, 1-2 hours). The mean length of stay after the procedure was 2.4 days (range, 1-10 days). There were no intraprocedural adverse events. One patient with severe pre-existing cardiac comorbidities died during his postprocedural stay despite a technically successful procedure. One patient had delayed closure of the long-standing cholecystocutaneous tract. CONCLUSIONS: Early clinical experience with PCEA using an LAMS suggests that it is a safe and effective option for the creation of internal gallbladder drainage in patients who are not candidates for surgical cholecystectomy.


Assuntos
Cálculos Biliares , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Cálculos Biliares/diagnóstico por imagem , Cálculos Biliares/cirurgia , Projetos Piloto , Endossonografia/métodos , Resultado do Tratamento , Drenagem/efeitos adversos , Anastomose Cirúrgica , Stents , Estudos Retrospectivos
5.
Minim Invasive Ther Allied Technol ; 32(6): 300-306, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37603037

RESUMO

INTRODUCTION: Robotic-assisted surgery has been a part of surgical procedures for more than two decades. Recently new robotic platforms with a different design entered the market. The modular design with independent arms enables increased flexibility of arm docking to increase the range of motion and instrument maneuverability. We herein present the first case series of robotic inguinal hernia repair using the Hugo RAS system (Medtronic, Minneapolis, MN, USA). MATERIAL AND METHODS: Thirteen inguinal hernia repairs were performed on ten patients. A description of the Hugo RAS system as well as the new concept of modular design is presented along with the description of the operation setup. RESULTS: Mean docking time was 9.5 min and mean console time was 50.3 min and 74.7 min for unilateral and bilateral inguinal hernia repair, respectively. No intraoperative or postoperative complications occurred. There was one conversion to laparoscopic surgery due to a technical issue with the robot. Conclusions: The modular design of independent arms seems to enhance maneuverability of the instruments and contribute to fewer arm collisions. Further clinical data and experience with this new surgical system are necessary to understand if this new design has advantages over the standard robotic platforms.


Assuntos
Hérnia Inguinal , Laparoscopia , Procedimentos Cirúrgicos Robóticos , Robótica , Humanos , Procedimentos Cirúrgicos Robóticos/métodos , Hérnia Inguinal/cirurgia , Laparoscopia/métodos , Complicações Pós-Operatórias , Herniorrafia/métodos , Estudos Retrospectivos
6.
J Gastrointest Surg ; 27(11): 2279-2286, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37620664

RESUMO

BACKGROUND: Gastroesophageal reflux disease (GERD) is a common condition, resulting from the loss of the anti-reflux barrier. Laparoscopic fundoplication is the surgical procedure of choice for treatment of GERD; however, there remains a debate on the exact mechanism through which it prevents reflux. OBJECTIVES: Our aim was to understand the relationship between reflux, fundoplication, and the angle of His on an experimental model. METHODS: The study was conducted on four groups of fresh explanted swine stomachs: control group, myotomy, myotomy with Nissen fundoplication, and myotomy with Toupet fundoplication. The stomachs were placed in a specially designated container on an inclinable platform which would increase the hydrostatic pressure on the esophago-gastric junction. Measurements of the angle of His using fluoroscopy and the esophago-gastric orifice area using endoscopy were performed, and the occurrence of reflux was documented. RESULTS: Each group of the study contained nine swine stomachs. In the control and myotomy groups, the angle became wider as the incline level increased the pressure and was significantly different between the groups (p < .001). Both groups demonstrated an increase in the orifice area as the incline level increased the pressure. There was a significant correlation between the angle of His and the area of the esophago-gastric orifice (p < .001). In the control group, the reflux began at the 0°. In the myotomy group, it began at the + 15° incline (less pressure). Reflux rarely occurred in the Nissen and Toupet groups, with the breaking point being mostly defined as "beyond - 30°". A significant difference was noted in the occurrence of reflux between fundoplication and the non-fundoplication groups (p < 0.001), while there was no significant difference between the Toupet and Nissen groups (p = 0.134). Analysis showed a significant independent correlation between both the angle of His and the orifice area with the presence of reflux (p = .002 and p = .024 respectively). CONCLUSIONS: In this study, we developed an experimental model to enable careful evaluation of the elements of the anti-reflux mechanism, of which, the angle of His has a measurable element. We demonstrated that as the angle of His becomes wider the esophago-gastric orifice area becomes larger. Additionally, a wider angle of His and a larger esophago-gastric orifice area were correlated independently with more reflux. This suggests that the fundoplication creates an acute angle of His which is correlated with a smaller area of the esophago-gastric orifice and eventually with a lower incidence of reflux.


Assuntos
Refluxo Gastroesofágico , Laparoscopia , Humanos , Resultado do Tratamento , Laparoscopia/métodos , Refluxo Gastroesofágico/prevenção & controle , Refluxo Gastroesofágico/cirurgia , Fundoplicatura/métodos
7.
Isr Med Assoc J ; 25(6): 392-397, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37381931

RESUMO

BACKGROUND: Abdominal pathology in pregnant patients is a frequent challenge for emergency department physicians. Ultrasound is the imaging modality of choice but is inconclusive in approximately one-third of cases. Magnetic resonance imaging (MRI) is becoming increasingly available, even in acute settings. Multiple studies have defined the sensitivity and specificity of MRI in this population. OBJECTIVES: To evaluate the use of MRI findings in pregnant patients presenting with acute abdominal complaints to the emergency department. METHODS: This retrospective cohort study was conducted at a single institution. Data were collected on pregnant patients who underwent an MRI for acute abdominal complaints between 2010 and 2019 at a university center. Patient demographics, diagnosis at admission, ultrasound and MRI findings, and discharge diagnosis were recorded and evaluated. RESULTS: In total, 203 pregnant patients underwent an MRI for acute abdominal complaints during the study period. MRI was found without pathology in 138 cases (68%). In 65 cases (32%), the MRI showed findings that could explain the patient's clinical presentation. Patients presenting with long-standing abdominal pain (> 24 hours), fever, leukocytosis, or elevated C-reactive protein values were at a significantly increased risk of having an acute pathology. In 46 patients (22.6%), MRI findings changed the primary diagnosis and management while in 45 patients (22.1%) MRI findings improved characterization of the suspected pathology. CONCLUSIONS: MRI is helpful when clinical and sonographic findings are inconclusive, leading to changes in patient management in more than one-fifth of patients.


Assuntos
Dor Abdominal , Serviço Hospitalar de Emergência , Feminino , Gravidez , Humanos , Estudos Retrospectivos , Dor Abdominal/etiologia , Febre , Imageamento por Ressonância Magnética
8.
J Gastrointest Surg ; 27(5): 878-886, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36720757

RESUMO

BACKGROUND: Peroral endoscopic myotomy (POEM) is rapidly becoming the procedure of choice for treating esophageal achalasia. In most centers, contrast-enhanced swallow studies (CESS) are routinely performed postoperatively to confirm mucosal integrity. The aim of this study was to determine the necessity of performing these studies routinely after POEM. METHODS: A retrospective review of a prospectively maintained database of patients who underwent POEM between December 2012 and November 2020 was performed. All patients underwent a CESS on the first postoperative day. Medical records including vital signs, complete blood count, and POD-1 CESS were evaluated. RESULTS: One hundred thirty-four consecutive patients were included in the study. Sixty-nine (51.49%) CESS showed abnormal findings; while most findings did not change the postoperative course, five (7.2%) demonstrated tunnel leaks, which did alter the overall management. Screening patients for fever, tachycardia, or leukocytosis on POD-1 had a 100% sensitivity and a 62% specificity for finding a clinically significant complication on CESS. CONCLUSIONS: The study findings suggest that performing routine contrast-enhanced swallow studies on all patients is not necessary following POEM, as leaks can be screened for by clinical or laboratory abnormalities. Herein, we propose an algorithm based on objective measurable findings for the selection of patients who should undergo CESS.


Assuntos
Procedimentos Cirúrgicos do Sistema Digestório , Acalasia Esofágica , Humanos , Acalasia Esofágica/cirurgia , Esfíncter Esofágico Inferior/cirurgia , Esofagoscopia , Cirurgia Endoscópica por Orifício Natural/métodos , Radiografia , Estudos Retrospectivos , Resultado do Tratamento
9.
Thorac Surg Clin ; 32(4): 437-445, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36266031

RESUMO

Accurate staging is imperative in the management of esophageal cancer Over the years, different treatment modalities have evolved, ranging from endoscopic resection to traditional surgical resection and multimodal approaches, including the addition of chemotherapy, with or without radiation. In this article, we discuss the different stage groups, which guide the clinician in determining staging for esophageal cancer, and subsequent guidance in appropriate treatment modalities for each patient. These groups are based on tumor, node, and metastasis (TNM) staging and have recently been refined into clinical TNM pathologic TNM, and post-neoadjuvant (ypTNM).


Assuntos
Neoplasias Esofágicas , Humanos , Estadiamento de Neoplasias , Neoplasias Esofágicas/cirurgia , Terapia Neoadjuvante , Prognóstico , Estudos Retrospectivos
10.
Minim Invasive Ther Allied Technol ; 31(4): 635-641, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33529074

RESUMO

BACKGROUND: Complete or partial fundoplication remains controversial for the surgical treatment of GERD. While partial fundoplication is considered less effective, it is associated with less post-operative dysphagia and gas bloating compared with complete fundoplication. AIM: To compare the mechanical efficiency of the three different types of fundoplication. MATERIAL AND METHOD: Two studies of the LES were performed on explanted stomachs: distensibility and failure point. Measurements were taken before and after fundoplication. RESULTS: There was no difference in distensibility between Nissen and Toupet fundoplication, however, the EGJ was more distensible following Dor fundoplication. According to failure point measurements, Nissen fundoplication was significantly more effective than Toupet, Toupet was significantly more effective than Dor (p = .016, p = .017, respectively). CONCLUSIONS: There were significant differences in distensibility between Dor and both Nissen and Toupet, however no statistical difference between Toupet and Nissen. There was a significant difference in effectiveness between all three types of fundoplication according to the failure point. These laboratory findings demonstrate that the mechanical orientation of Nissen and Toupet have similar functionality suggesting that Toupet is as good as Nissen. While in clinical studies Toupet has fewer post-operative complications these findings support the proponents of Toupet for GERD. Abbreviation: GERD: Gastroesophageal reflux disease.


Assuntos
Fundoplicatura , Refluxo Gastroesofágico , Fundoplicatura/efeitos adversos , Fundoplicatura/métodos , Refluxo Gastroesofágico/cirurgia , Humanos , Complicações Pós-Operatórias/epidemiologia , Resultado do Tratamento
12.
J Laparoendosc Adv Surg Tech A ; 31(2): 183-188, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32668169

RESUMO

Background: Achalasia may occasionally occur among women of childbearing age. Pregnancy may lead to deterioration of the disease and negatively affect maternal and perinatal outcomes. However, the impact of peroral endoscopic myotomy (POEM) on reproductive outcomes has been understudied. Methods: A retrospective study on prospectively maintained database, including women aged 18-45 who underwent POEM during 2012-2017 at a university hospital. Results: During the study period, POEM was performed in 86 patients. Of them, 23 were women of childbearing age (median age 31.9 [26.0-40.7] years). Follow-up data were available for a median of 24 [16-41] months. Treatment success (Eckardt score <3) was achieved in 22 (95.7%) women. Six (26.1%) women reported attempting to conceive after POEM. Overall, 7 post-POEM pregnancies among 5 women were encountered. All 7 pregnancies were naturally conceived with a median surgery-to-conception interval of 16 [10-21] months. The median gestational weight gain was 10 kg, and was insufficient in all pregnancies. None of the women was hospitalized during the index gestation. All pregnancies resulted in term live-birth vaginal delivery. The median neonatal birthweight was 2940 g, with only one case of a small-for-gestational age infant. Achalasia-related symptoms recurred during 2 pregnancies, with resolution following delivery. Conclusions: Pregnancy after POEM for the treatment of achalasia was associated with favorable maternal and perinatal outcomes. This data should reassure women who wish to conceive following peroral myotomy.


Assuntos
Acalasia Esofágica/cirurgia , Adolescente , Adulto , Bases de Dados Factuais , Feminino , Humanos , Pessoa de Meia-Idade , Miotomia/métodos , Cirurgia Endoscópica por Orifício Natural/métodos , Período Pós-Operatório , Gravidez , Estudos Prospectivos , Reprodução , Estudos Retrospectivos , Adulto Jovem
13.
Surg Endosc ; 35(11): 6117-6122, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-33104914

RESUMO

BACKGROUND: POEM (Per Oral Endoscopic Myotomy) is rapidly becoming a valid option for surgical myotomy in achalasia patients. Several techniques to perform POEM are described, but all concentrate on the division of the circular muscle fibers in a proximal-to-distal fashion. Our aim is to present the distal-to-proximal, or the bottom-up technique using the Flush/Dual knife, which overcomes the disadvantages of the standard technique. METHODS: A retrospective study on a prospectively maintained database was performed on all patients treated by POEM in our institution. Clinical presentation, operating time, adverse events, and outcomes were studied. RESULTS: POEM was performed on 105 achalasia patients. The first 15 cases were performed using the standard technique and were compared to the next 90 cases performed using the bottom-up technique. The average preop Eckardt scores in the standard and bottom-up groups were 9.5 and 8.8, respectively, declining to 1.4 and 0.5, 3 months post myotomy (p < 0.001). The average procedure time was 111.2 min for the standard technique and 74.3 for the bottom-up technique. (p = 0.002). Perioperative adverse events included 14 instances of pneumoperitoneum, 3 tunnel leaks, and 4 patients with fever on postoperative day one. Pneumoperitoneum needing decompression and postoperative fever were more prevalent in the standard technique group. CONCLUSIONS: As POEM is becoming more common for the treatment of achalasia, refinements of the technique and instruments used are valuable. We compared our experience of the standard technique to our bottom-up technique and found the latter to be equally effective as well as safer, faster, and easier. We, therefore, suggest considering performing POEM in this technique.


Assuntos
Acalasia Esofágica , Cirurgia Endoscópica por Orifício Natural , Acalasia Esofágica/cirurgia , Esfíncter Esofágico Inferior , Humanos , Estudos Retrospectivos , Resultado do Tratamento
14.
ACS Appl Mater Interfaces ; 11(40): 37112-37120, 2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31532992

RESUMO

Using a specially designed apparatus, which collects simultaneous temperature and X-ray scattering data, we performed in situ measurements of the filament during MatEx 3D printing. The data show that the MatEx 3D printing extrusion process provides sufficient shear to form shish-kebab structures, which initially nucleate at the filament surface and spread into the filament core. Time-resolved measurements show that the kebab component near the surface relaxes after deposition of the second filament and enhances chain diffusion across the interface. SEM images indicate near complete interfacial merging of the filaments, which results in excellent mechanical properties.

15.
Ann Vasc Surg ; 60: 474.e1-474.e5, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30711502

RESUMO

Hepatic hydatid cysts (HHCs) are common in endemic areas. Mostly they are asymptomatic, but some cause serious complications. We report 2 cases of HHC complicated arterial bleeding. Owing to signs of active bleeding, the patients were treated with selective embolization of the hepatic artery to stop the bleeding and stabilize the patients' condition. Subsequently, partial hepatectomy of the involved liver lobe was performed in an elective setting and without postoperative complications. We recommend bridging therapy by selective angiography and embolization for hemorrhagic hepatic hydatid cyst before definitive surgical treatment.


Assuntos
Equinococose Hepática/cirurgia , Embolização Terapêutica , Hemorragia/terapia , Hepatectomia , Artéria Hepática , Adulto , Equinococose Hepática/complicações , Equinococose Hepática/diagnóstico por imagem , Feminino , Hemorragia/diagnóstico por imagem , Hemorragia/etiologia , Artéria Hepática/diagnóstico por imagem , Humanos , Masculino , Resultado do Tratamento
16.
Asian J Surg ; 42(6): 702-707, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30446425

RESUMO

BACKGROUND: Hydatid cyst is a zoonotic disease caused by Echinococcus genera. Surgery is needed in most cases. We aimed to describe our center's experience in the surgical management of hepatic hydated cysts (HHC). METHODS: Data was retrospectively collected for patients who underwent operative management for HHC between the years 1994-2014. RESULTS: Sixty-nine underwent surgical treatment for HHC. Group A included 34 treated with an unroofing procedure, group B included 24 patients who underwent hepatectomy and group C included 11 patients who underwent peri-cystectomy. The median ± (range) age for groups A, B and C were 39.5 (6.5-69), 40 (17-74) and 32 (20-62), respectively (P > 0.1). Post-operative complications occurred in 16, 11 and 5 patients in group A, B and C, respectively, as assessed by clavien-dindo classification (CDC). The average CDC was significantly higher in the hepatectomy group as compared to the unroofing group (2.3 vs.1.5, P = 0.04). Recurrence was significantly higher after the unroofing procedure as compared to the hepatectomy group (P = 0.05). CONCLUSION: Surgery remains the mainstay of treatment for HHC, once surgery is pursued, the results are satisfactory.


Assuntos
Equinococose Hepática/cirurgia , Fígado/cirurgia , Adolescente , Adulto , Fatores Etários , Idoso , Criança , Procedimentos Cirúrgicos do Sistema Digestório/métodos , Equinococose Hepática/mortalidade , Feminino , Hepatectomia , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/epidemiologia , Recidiva , Estudos Retrospectivos , Fatores de Tempo , Resultado do Tratamento , Adulto Jovem
17.
Minim Invasive Ther Allied Technol ; 27(6): 321-326, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29616866

RESUMO

Introduction: Recently, magnetic solutions have been proposed to minimize surgical invasiveness. These are comprised of deployable instruments containing magnets which are inserted into the abdominal cavity through a single access point. The manipulation of the internal elements occurs via magnets held on the external surface of the abdominal wall. This technology relies on the magnetic force between the magnets, which is inversely related to the abdominal wall thickness (AWT). The aim of this study was to establish the expected change in AWT from before and after initiation of pneumoperitoneum. Material and methods: Patients scheduled for laparoscopic procedures were assessed by ultrasound for AWT immediately before and during laparoscopy. Change of AWT during laparoscopy was calculated. Statistical analysis was performed using Student's t-test. Results: Thirty-two patients undergoing various laparoscopic procedures were included. Twenty patients were male (62.5%) and ten were morbidly obese (31%). Mean age was 51 years (range 18-76) and average BMI was 28.1 kg/m2 (range 19.0-41.0). AWT decreased on average by 15.6% once pneumoperitoneum was initiated in both obese and non-obese patients (p = .01). Conclusion: Our data suggest that following preoperative assessment of AWT with abdominal wall ultrasound, more patients than expected might be candidates for the use of trans-abdominal magnetic devices.


Assuntos
Parede Abdominal/diagnóstico por imagem , Laparoscopia/métodos , Obesidade Mórbida/complicações , Ultrassonografia/métodos , Adolescente , Adulto , Idoso , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Adulto Jovem
18.
Artigo em Inglês | MEDLINE | ID: mdl-25492166

RESUMO

Tendons are among the most robust structures in nature. Using the structural properties of natural tendon as a foundation for the development of micro-yarns may lead to innovative composite materials. Gelatin monofilaments were prepared by casting and spinning and small yarns--with up to ten filaments--were assembled into either parallel or 15° twisted yarns. The latter were intended as an attempt to generate mechanical effects similar to those arising from the crimp pattern in tendon. The mechanical properties of parallel and 15° twisted gelatin yarns were compared. The effect of an increasing number of filaments per yarn was also examined. The mechanical properties were mostly affected by the increasing number of filaments, and no benefit arose from twisting small yarns by 15°. However, since gelatin filaments are elasto-plastic rather than fully elastic, much increased toughness (by up to a factor of five for a ten filament yarn) can be achieved with yarns made of elasto-plastic filaments, as demonstrated by experiments and numerical simulations. The resulting effect shows some resemblance to the effect of crimp in tendons. Finally, we developed a dependable procedure to measure the toughness of single filaments based on the test of a yarn rather than on a large number of individual filament tests.


Assuntos
Gelatina , Tendões , Materiais Biocompatíveis , Fenômenos Biomecânicos , Teste de Materiais , Microscopia Eletrônica de Varredura
19.
Langmuir ; 28(17): 6978-84, 2012 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-22452574

RESUMO

This study presents a method for one-step formation of poly(ethylene oxide) nanofibers incorporating nanoparticles of a poorly water-soluble compound. Using the new method reported here, nanofiber-nanoparticle composites are fabricated in one step by electrospinning of an oil-in-water microemulsion, in which a model material, propylparaben, has been dissolved within the volatile dispersed phase in the presence of a high-molecular-weight polymer. The approach is based on nanoscale confinement to the dispersed phase of an oil-in-water microemulsion with a volatile oil phase, in which the poorly water-soluble materials are dissolved. Thus, when the thermodynamically stable oil-in-water microemulsion is combined with the rapid evaporation of solvent inherent in the electrospinning process, the droplets are converted into organic nanoparticles embedded within a polymeric nanofiber. In addition to possessing process simplicity, this method exhibits a very high percentage of nanoparticle loading with desirable active material properties. Specifically, the diameter of the nanofibers is in the range of 60-185 nm, and propylparaben exists within the nanofiber as nanocrystals of 30-120 nm. These dimensions suggest that the nanofiber-nanocrystal composites could serve as a delivery system for water-insoluble materials.


Assuntos
Nanopartículas/química , Nanotecnologia/métodos , Parabenos/química , Condutividade Elétrica , Emulsões , Nanofibras/química , Tamanho da Partícula , Polietilenoglicóis/química , Solubilidade , Volatilização , Água/química , Difração de Raios X
20.
Adv Colloid Interface Sci ; 128-130: 37-46, 2006 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-17222381

RESUMO

The discovery of carbon nanotubes offers exciting opportunities for the development of novel high property materials. Disaggregation and uniform dispersion are critical challenges that must be met to successfully produce such high property materials, since carbon nanotubes tend to self-associate into micro-scale aggregates. This results in products with inferior mechanical and electric performance. Recognizing this problem, extensive research has been reported in the literature on development of dispersion technologies based on both mechanical and chemical approaches. Here, we review recent progress and advances that have been made on dispersion of carbon nanotubes in aqueous and organic media by non-covalent adsorption of surfactants and polymers. Carbon nanotube structure, properties and mainly self-assembly are discussed in detail.

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