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F.W. Westaway wrote numerous influential books on science and the teaching of science, including 'The Endless Quest: Three Thousand Years of Science' and 'Science Teaching: What It Was, What It Is, What It Might Be.' He influenced others with his ideas that science and the humanities should work together for the greater good.

A description is presented of the life and achievements of chemistry teacher George Fowles (1882-1969). His authorship of books on the subject of chemistry teaching and criticism of the Nuffield O-level Chemistry Teaching Project are discussed.

Clothilde von Wyss was a well-known figure in sciences education at the beginning of the 20th century. She taught at the University of London Institute of Education from 1903 to 1936, and is known for her work with the School Nature Study Union (SNSU). This organization promoted the study of nature, which was an important part of primary school education during the first six decades of the 20th century. Von Wyss edited the SNSU's School Nature Study journal for 30 years, wrote several texts on natural history and educational broadcasters consulted her as an authority on wood ants.

Henry Cabourn Pocklington specialized in mathematics and physics in his final year at the Yorkshire College of Science. He obtained a degree in Electro-metallurgy in 1886, and in 1887 passed the London Matriculation Examination. He subsequently studied at Cambridge University, England, and gained a range of academic honours. He became a Demonstrator at the Leeds Higher Grade School in 1895, and remained at this school as a physics teacher until he retired in 1926.

Purpose: Bone marrow-derived, allogeneic, multipotent adult progenitor cells demonstrated safety and efficacy in preclinical models of acute respiratory distress syndrome (ARDS)., Methods: This phase 1/2 trial evaluated the safety and tolerability of intravenous multipotent adult progenitor cells in patients with moderate-to-severe ARDS in 12 UK and USA centres. Cohorts 1 and 2 were open-label, evaluating acute safety in three subjects receiving 300 or 900 million cells, respectively. Cohort 3 was a randomised, double-blind, placebo-controlled parallel trial infusing 900 million cells (n = 20) or placebo (n = 10) within 96 h of ARDS diagnosis. Primary outcomes were safety and tolerability. Secondary endpoints included clinical outcomes, quality of life (QoL) and plasma biomarkers., Results: No allergic or serious adverse reactions were associated with cell therapy in any cohort. At baseline, the cohort 3 cell group had less severe hypoxia. For cohort 3, 28-day mortality was 25% for cell vs. 45% for placebo recipients. Median 28-day free from intensive care unit (ICU) and ventilator-free days in the cell vs. placebo group were 12.5 (IQR 0,18.5) vs. 4.5 (IQR 0,16.8) and 18.5 (IQR 0,22) vs. 6.5 (IQR 0,18.3), respectively. A prospectively defined severe ARDS subpopulation (PaO 2 /FiO 2  < 150 mmHg (20 kPa); n = 16) showed similar trends in mortality, ICU-free days and ventilator-free days favouring cell therapy. Cell recipients showed greater recovery of QoL through Day 365., Conclusions: Multipotent adult progenitor cells were safe and well tolerated in ARDS. The clinical outcomes warrant larger trials to evaluate the therapeutic efficacy and optimal patient population., (© 2021. Crown.)

Purpose: The purpose of this study is to evaluate the histologic response to fibrin sealant (FS) as an alternative fixation method for laparoscopic ventral hernia repair., Methods: One non-absorbable barrier mesh (Composix™) and three absorbable barrier meshes (Sepramesh™, Proceed™, and Parietex™ Composite) were used for the study, with uncoated macroporous polypropylene mesh (ProLite Ultra™) as the control. Three methods of fixation were used: #0-polypropylene suture + FS (ARTISS™, Baxter Healthcare Corp.), FS alone (ARTISS™), or tacks alone (n = 10 for each group). Two pieces of mesh (of dimensions 4 × 4-cm) were secured intraperitoneally in 75 New Zealand white rabbits. After 8 weeks, hematoxylin and eosin (H&E)-stained specimens were evaluated for host tissue response. Statistical significance (P < 0.05) was determined using a one-way analysis of variance (ANOVA) with Fisher's least significant difference (LSD) post hoc test., Results: Composix™ with FS only showed significantly greater cellular infiltration than with suture + FS (P = 0.0007), Proceed™ with FS only had significantly greater neovascularization than with suture + FS (P = 0.0172), and ProLite Ultra™ with suture + FS had significantly greater neovascularization than with tacks only (P = 0.046). Differences due to mesh type showed that Composix™ exhibited less extensive cellular infiltration (P ≤ 0.0032), extracellular matrix (ECM) deposition, and neovascularization, and demonstrated less inflammatory cells and more fibroblasts compared to the other meshes (P < 0.05)., Conclusions: FS did not have a significant histologic effect compared to tacks when utilized for the fixation of mesh to the peritoneum of New Zealand White rabbits. However, the mesh type did have a significant histologic effect. The permanent barrier mesh (Composix™) was associated with less histologic incorporation than absorbable barrier and macroporous meshes, as evidenced by lower levels of cellular infiltration, ECM deposition, and neovascularization, independent of the fixation method used.

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.

Background: The objective of this study was to determine the acute and chronic fixation strengths achieved by fibrin or polyethylene glycol (PEG) sealants to secure biologic mesh at the esophageal hiatus in a porcine model., Methods: For this study, 32 female domestic pigs were divided into four groups of 8 each. The four groups respectively received acute fibrin sealant, acute PEG sealant, chronic fibrin sealant, and chronic PEG sealant. Laparoscopically, a 5.5 × 8.5-cm piece of Biodesign Surgisis Hiatal Hernia Graft (porcine small intestine submucosa) was oriented with the U-shaped cutout around the gastroesophageal junction and the short axis in the craniocaudal direction to simulate hiatal reinforcement with a biologic mesh. The mesh then was secured with 2 ml of either fibrin sealant or PEG sealant. The pigs in the acute groups were maintained alive for 2 h to allow for complete polymerization of the sealants, and the pigs in the chronic group were maintained alive for 14 days. After the pigs were euthanized, specimens of the mesh-tissue interface were subjected to lap shear testing to determine fixation strength, and hematoxylin and eosin (H&E) stained slides were evaluated for evidence of remodeling., Results: No significant differences were observed between the acute and chronic fixation strengths or the remodeling characteristics of the two sealants. However, fixation strength increased significantly over time for both types of sealant. Evidence of remodeling also was significantly more pronounced in the chronic specimens than in the acute specimens., Conclusions: This study demonstrated the feasibility of using fibrin or PEG sealants to secure biologic mesh at the hiatus in a porcine model.

Purpose: To evaluate the biocompatibility of heavyweight polypropylene (HWPP), lightweight polypropylene (LWPP), and monofilament knit polytetrafluoroethylene (mkPTFE) mesh by comparing biomechanics and histologic response at 1, 3, and 5 months in a porcine model of incisional hernia repair., Methods: Bilateral full-thickness abdominal wall defects measuring 4 cm in length were created in 27 Yucatan minipigs. Twenty-one days after hernia creation, animals underwent bilateral preperitoneal ventral hernia repair with 8 × 10 cm pieces of mesh. Repairs were randomized to Bard(®)Mesh (HWPP, Bard/Davol, http://www.davol.com), ULTRAPRO(®) (LWPP, Ethicon, http://www.ethicon.com), and GORE(®)INFINIT Mesh (mkPTFE, Gore & Associates, http://www.gore.com). Nine animals were sacrificed at each timepoint (1, 3, and 5 months). At harvest, a 3 × 4 cm sample of mesh and incorporated tissue was taken from the center of the implant site and subjected to uniaxial tensile testing at a rate of 0.42 mm/s. The maximum force (N) and tensile strength (N/cm) were measured with a tensiometer, and stiffness (N/mm) was calculated from the slope of the force-versus-displacement curve. Adjacent sections of tissue were stained with hematoxylin and eosin (H&E) and analyzed for inflammation, fibrosis, and tissue ingrowth. Data are reported as mean ± SEM. Statistical significance (P < 0.05) was determined using a two-way ANOVA and Bonferroni post-test., Results: No significant difference in maximum force was detected between meshes at any of the time points (P > 0.05 for all comparisons). However, for each mesh type, the maximum strength at 5 months was significantly lower than that at 1 month (P < 0.05). No significant difference in stiffness was detected between the mesh types or between timepoints (P > 0.05 for all comparisons). No significant differences with regard to inflammation, fibrosis, or tissue ingrowth were detected between mesh types at any time point (P > 0.09 for all comparisons). However, over time, inflammation decreased significantly for all mesh types (P < 0.001) and tissue ingrowth reached a slight peak between 1 and 3 months (P = 0.001) but did not significantly change thereafter (P > 0.09)., Conclusions: The maximum tensile strength of mesh in the abdominal wall decreased over time for HWPP, LWPP, and mkPTFE mesh materials alike. This trend may actually reflect inability to adequately grip specimens at later time points rather than any mesh-specific trend. Histologically, inflammation decreased with time (P = 0.000), and tissue ingrowth increased (P = 0.019) for all meshes. No specific trends were observed between the polypropylene meshes and the monofilament knit PTFE, suggesting that this novel construction may be a suitable alternative to existing polypropylene meshes.

Background: The objective of this study was to evaluate the biomechanical characteristics and histologic remodeling of crosslinked (Peri-Guard, Permacol) and non-crosslinked (AlloDerm, Veritas) biologic meshes over a 12 month period using a porcine model of incisional hernia repair., Study Design: Bilateral incisional hernias were created in 48 Yucatan minipigs and repaired after 21 days using an underlay technique. Samples were harvested at 1, 6, and 12 months and analyzed for biomechanical and histologic properties. The same biomechanical tests were conducted with de novo (time 0) meshes as well as samples of native abdominal wall. Statistical significance (p < 0.05) was determined using 1-way analysis of variance with a Fisher's least significant difference post-test., Results: All repair sites demonstrated similar tensile strengths at 1, 6, and 12 months and no significant differences were observed between mesh materials (p > 0.05 in all cases). The strength of the native porcine abdominal wall was not augmented by the presence of the mesh at any of the time points, regardless of de novo tensile strength of the mesh. Histologically, non-crosslinked materials showed earlier cell infiltration (p < 0.01), extracellular matrix deposition (p < 0.02), scaffold degradation (p < 0.05), and neovascularization (p < 0.02) compared with crosslinked materials. However, by 12 months, crosslinked materials showed similar results compared with the non-crosslinked materials for many of the features evaluated., Conclusions: The tensile strengths of sites repaired with biologic mesh were not impacted by very high de novo tensile strength/stiffness or mesh-specific variables such as crosslinking. Although crosslinking distinguishes biologic meshes in the short-term for histologic features, such as cellular infiltration and neovascularization, many differences diminish during longer periods of time. Characteristics other than crosslinking, such as tissue type and processing conditions, are likely responsible for these differences., (Copyright © 2011 American College of Surgeons. Published by Elsevier Inc. All rights reserved.)

Purpose: Biologic meshes have unique physical properties as a result of manufacturing techniques such as decellularization, crosslinking, and sterilization. The purpose of this study is to directly compare the biocompatibility profiles of five different biologic meshes, AlloDerm(®) (non-crosslinked human dermal matrix), PeriGuard(®) (crosslinked bovine pericardium), Permacol(®) (crosslinked porcine dermal matrix), Strattice(®) (non-crosslinked porcine dermal matrix), and Veritas(®) (non-crosslinked bovine pericardium), using a porcine model of ventral hernia repair., Methods: Full-thickness fascial defects were created in 20 Yucatan minipigs and repaired with the retromuscular placement of biologic mesh 3 weeks later. Animals were euthanized at 1 month and the repair sites were subjected to tensile testing and histologic analysis. Samples of unimplanted (de novo) meshes and native porcine abdominal wall were also analyzed for their mechanical properties., Results: There were no significant differences in the biomechanical characteristics between any of the mesh-repaired sites at 1 month postimplantation or between the native porcine abdominal wall without implanted mesh and the mesh-repaired sites (P > 0.05 for all comparisons). Histologically, non-crosslinked materials exhibited greater cellular infiltration, extracellular matrix (ECM) deposition, and neovascularization compared to crosslinked meshes., Conclusions: While crosslinking differentiates biologic meshes with regard to cellular infiltration, ECM deposition, scaffold degradation, and neovascularization, the integrity and strength of the repair site at 1 month is not significantly impacted by crosslinking or by the de novo strength/stiffness of the mesh.

Background: The purpose of this study was to compare tissue incorporation and adhesion characteristics of a novel fenestrated versus nonfenestrated crosslinked porcine dermal matrix (CPDM) (Bard CollaMend) in a porcine model of ventral hernia repair., Study Design: Bilateral abdominal wall defects were created in 24 Yucatan minipigs, resulting in 48 defects, which were allowed to mature for 21 days. Twelve defects were repaired with fenestrated CPDM using a preperitoneal technique, 12 with fenestrated CPDM using an intraperitoneal technique, 12 with nonfenestrated CPDM using a preperitoneal technique, and 12 with nonfenestrated CPDM using an intraperitoneal technique. Half of the animals in the intraperitoneal group were euthanized after 1 month, and the other half after 3 months. Similarly, half of the animals in the preperitoneal group were euthanized after 1 month, and the other half after 6 months. Biomechanical testing and histologic evaluation were performed., Results: Intraperitoneal placement of the CPDM products resulted in significantly greater adhesed area compared with preperitoneal placement (p < 0.05). Tissue ingrowth into preperitoneal fenestrated and nonfenestrated CPDM resulted in significantly greater incorporation strengths after 6 months compared with 1 month (p = 0.03 and p < 0.0001). Histologic analysis showed significantly greater cellular infiltration, extracellular matrix deposition, and neovascularization, with less fibrous encapsulation through the center of the fenestrations compared with all other sites evaluated, including nonfenestrated grafts., Conclusions: Histologic findings revealed increased tissue incorporation at fenestration sites compared with nonfenestrated grafts regardless of implant location or time in vivo. However, preperitoneal placement resulted in greater incorporation strength, less adhesed area, and lower adhesion scores compared with intraperitoneal placement for both fenestrated and nonfenestrated CPDM., (Copyright © 2011 American College of Surgeons. Published by Elsevier Inc. All rights reserved.)

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.

Background: The purpose of this study was to compare perioperative outcomes for intracorporeal versus extracorporeal anastomotic techniques for isolated laparoscopic small-intestine resection., Methods: A retrospective database was created for all adult patients who underwent a laparoscopic segmental small-intestine resection. Patients with inflammatory bowel disease or requiring an ileocolectomy were excluded., Results: Laparoscopic resection was performed in 52 patients (ratio of men:women, 30:22) with a mean age of 47 ± 21 years. A laparoscopic intracorporeal anastomosis was performed in 30 patients (58%), and an extracorporeal anastomosis was performed in 22 patients (42%). There was no difference in mean operating room time, estimated blood loss, perioperative complication rate, or length of stay between the 2 groups. Ten patients had a complication, and 5 patients experienced a Clavien grade II or greater complication., Conclusions: Laparoscopic segmental small-bowel resection using either intracorporeal or extracorporeal anastomotic techniques is equally efficacious for pathology isolated to the small bowel., (Copyright © 2010 Elsevier Inc. All rights reserved.)

Background: The purpose of this comparative study is to evaluate the acute fixation strength of mechanical tacking devices and fibrin sealant against polypropylene suture for laparoscopic ventral hernia repair., Methods: Three metallic mechanical tacking devices (ProTack, Salute, EndoANCHOR), 4 absorbable tacking devices (AbsorbaTack, PermaSorb, I-Clip, and SorbaFix), and 2 types of fibrin sealant (Tisseel, Artiss) were compared with 0-polypropylene suture. Three constructs from each device or an amount of sealant sufficient to cover a 3 × 3 cm(2) area were used to affix a 4 × 3 cm piece of absorbable barrier-coated mesh (Proceed, Ethicon, Inc) to the peritoneal surface of porcine abdominal wall. Ten samples were completed for each fixation modality. Acute fixation strength was measured via a lap shear test on an Instron tensiometer., Results: Acute fixation strength was significantly greater for suture (59.7 7.2 N) compared with all laparoscopic tacking devices and to fibrin sealant (P < .001 for all comparisons). Protack (29.5 ± 2.8 N) was stronger than Absorbatack (13.2 ± 3.7 N; P = .029). Protack, Permasorb, SorbaFix, and I-clip were stronger than fibrin sealant (P < .05 for all comparisons)., Conclusions: The acute fixation strengths of metallic or absorbable tacks as well as fibrin sealant are all significantly less than that achieved with polypropylene suture. These factors should be considered in selecting the type of mechanical fixation for patients undergoing laparoscopic ventral hernia repair.

Introduction: The purpose of this study is to compare the tissue incorporation of a novel fenestrated and non-fenestrated crosslinked porcine dermal matrix (CPDM) (CollaMend™, Davol Inc., Warwick, RI) in a porcine model of ventral hernia repair., Methods: Bilateral abdominal wall defects were created in 12 Yucatan minipigs and repaired with a preperitoneal or intraperitoneal technique 21 days after hernia creation. Animals were randomized to fenestrated or non-fenestrated CPDM for n = 6 pieces of each graft in the preperitoneal or intraperitoneal location. All animals were sacrificed at 1 month. Adhesion characteristics and graft contraction/growth were measured by the Garrard adhesion grading scale and transparent grid overlay. Histological analysis of hematoxylin and eosin (H&E)-stained slides was performed to assess graft incorporation. Tissue incorporation strength was measured by a T-peel tensile test. The strength of explanted CPDM alone and de novo CPDM was measured by a uniaxial tensile test using a tensiometer (Instron, Norwood, MA) at a displacement rate of 0.42 mm/s. Statistical significance (P < 0.05) was determined for histological analysis using a Kruskal-Wallis non-parametric test with a Bonferroni correction, and for all other analyses using a two-way analysis of variance (ANOVA) with a Bonferroni post-test or a Kruskal-Wallis non-parametric test with a Dunn's post-test., Results: Intraperitoneal placement of fenestrated CPDM resulted in a significantly higher area of adhesions and adhesion score compared to the preperitoneal placement of fenestrated CPDM (P < 0.05). For both preperitoneal and intraperitoneal placement, histological findings demonstrated greater incorporation of the graft due to the fenestrations. No significant differences were detected in the uniaxial tensile strengths of the graft materials alone, either due to the graft type (non-fenestrated vs. fenestrated) or due to the placement location (preperitoneal vs. intraperitoneal). The incorporation strength (T-peel force) was significantly greater for fenestrated compared to non-fenestrated CPDM when placed in the preperitoneal location (P < 0.01). The incorporation strength was also significantly greater for fenestrated CPDM placed in the preperitoneal location compared to fenestrated CPDM placed in the intraperitoneal location (P < 0.05)., Conclusions: Fenestrations in CPDM result in greater tissue incorporation strength and lower adhesion area and score when placed in the preperitoneal location. Fenestrations in CPDM allow for greater tissue incorporation without accelerating graft degradation. Fenestrations may be placed in CPDM while still allowing adequate graft strength for intraperitoneal and preperitoneal hernia repairs at 1 month in a porcine model.

Background: The purpose of this study was to characterize the adhesion characteristics of absorbable- and nonabsorbable-barrier-coated meshes and to report adhesiolysis-related complications during laparoscopic re-exploration after prior ventral hernia repair., Methods: Under an IRB-approved protocol, patients undergoing laparoscopic re-exploration after prior intraperitoneal mesh placement were prospectively graded intraoperatively for adhesion tenacity (0-4), adhesion surface area (0 = 0%, 10 = 100%), and ratio of adhesiolysis time to mesh surface area (min/cm(2)). Adhesiolysis-related complications were also recorded. Data are given as mean ± SD. Statistical significance (P < 0.05) was determined using the t test and Fisher's exact test., Results: From March 2006 to March 2009, 69 patients underwent laparoscopic surgery after prior intraperitoneal mesh placement for ventral hernia repair. Previous meshes were absorbable-barrier-coated mesh (n = 18), permanent-barrier composite mesh [Composix® (n = 17)], permanent-barrier noncomposite mesh [DualMesh® (n = 14)], uncoated polypropylene mesh (n = 12), and biologic mesh (n = 8). Indications for laparoscopic re-exploration were recurrent ventral hernia (n = 58), chronic pain (n = 3), cholecystectomy (n = 3), parastomal hernia (n = 2), small bowel obstruction (n = 1), nephrectomy (n = 1), and Nissen fundoplication (n = 1). Adhesions to DualMesh were less tenacious (P < 0.05) compared to all other meshes. Surface area of adhesions to DualMesh were less (P < 0.05) than to Composix and to uncoated polypropylene mesh, but not to absorbable-barrier-coated and biologic meshes. Adhesiolysis time:mesh surface area was less (P < 0.05) for DualMesh compared to Composix, uncoated polypropylene, and biologic mesh, but not to absorbable-barrier-coated mesh. Adhesiolysis-related complications occurred in two (16.7%) (P = ns) patients with uncoated polypropylene mesh, one cystotomy and one enterotomy; both were repaired laparoscopically. There were two (16.7%) (P = ns) conversions to an open procedure: one converted patient had Composix (6.7%) and one had absorbable-barrier-coated mesh (5.9%). There were no adhesiolysis-related complications with these meshes. There were no adhesiolysis-related complications or conversions to open in the DualMesh or biologic mesh groups., Conclusions: Adhesion characteristics of mesh placed intraperitoneally and adhesiolysis-related complications during laparoscopic re-exploration after ventral hernia repair are associated with unique properties of the mesh and/or barrier.

Introduction: The purpose of this study was to evaluate the acute fixation strength of fibrin sealant as an alternative fixation method for laparoscopic ventral hernia repair (LVHR) when utilized with absorbable and nonabsorbable barrier meshes., Methods: Representative mesh types for LVHR included one nonabsorbable barrier mesh (Bard Composix) and three absorbable barrier meshes (Sepramesh, Proceed, and Parietex Composite Mesh). Macroporous polypropylene mesh (Prolite Ultra) served as a control. An associated pilot study demonstrated that acute fixation was not achieved with C-Qur or Dualmesh, thus these meshes were not subjected to further analysis. Two fibrin sealants varying in thrombin concentration (TISSEEL 500 IU/ml or ARTISS 4 IU/ml) were each utilized to secure a 3 x 4 cm piece of mesh to the peritoneal surface of harvested abdominal wall from New Zealand white rabbits. Ten samples were prepared for each mesh and fibrin sealant combination. The resulting mesh-tissue interface (3 x 3 cm) underwent lap shear testing at a rate of 0.42 mm/s using a tensiometer (Instron 5542, Norwood, MA). The maximum load sustained by the construct was recorded as the acute fixation strength in units of Newtons (N). Data are given as means +/- SEM. Statistical significance (P < 0.05) was determined using a two-way ANOVA and Bonferroni post-test., Results: There was no significant difference (P > 0.05) in the acute fixation strength achieved by ARTISS versus TISSEEL with Composix, Sepramesh, Proceed, and Parietex Composite Mesh. However, Prolite Ultra fixed with ARTISS (7.099 +/- 1.01 N) had a significantly higher tensile strength (P < 0.001) than Prolite Ultra fixed with TISSEEL (3.405 +/- 0.72 N). Among meshes fixed with TISSEEL, Parietex Composite (3.936 +/- 0.73 N) was significantly stronger than Sepramesh (1.760 +/- 0.33 N) (P < 0.05)., Conclusions: Acute fixation strength is equivalent for TISSEEL and ARTISS fibrin sealants for selected nonabsorbable (Composix) and absorbable barrier-coated (Sepramesh, Proceed, and Parietex Composite Mesh) meshes. Previous evaluations in this model indicated fibrin sealant alone did not appear to be a suitable method of fixation with C-Qur or DualMesh against the peritoneum. Long-term evaluation is needed to evaluate the efficacy of this method of fixation using absorbable and nonabsorbable barrier-coated meshes in a model of LVHR.

Background: Because of uncertainties about the complexity of laparoscopic ventral hernia repair for varying patient populations, surgeons may be reluctant to perform this procedure. This study aimed to delineate the risk factors that can be identified in the preoperative setting predictive of longer operative times and complexity in laparoscopic ventral hernia repair., Methods: Patient demographics including body mass index (BMI), comorbidities, previous laparoscopic and open surgical procedures, ventral hernia repairs, and hernia characteristics (defect size and location, adhesions, incarceration) were recorded prospectively. Data are given as mean +/- standard deviation. Times (min) required for abdominal access, adhesiolysis, and mesh placement as well as the total operative time were recorded during each case as outcome measures of operative difficulty. Univariate analyses were performed with the t-test or the Mann-Whitney U test as well as multivariate analyses using the stepwise analysis of covariance model to determine demographic and clinical variables influencing operative times., Result: The study enrolled 180 patients (78 men and 102 women) with a mean age of 54.8 +/- 12.2 years and a mean BMI of 33.3 +/- 13.0 kg/m(2). Multivariate analysis demonstrated significantly longer (p < 0.05) adhesiolysis and total operative times for patients with prior ventral hernia repairs, suprapubic hernia, bowel adhesion to the abdominal wall or hernia sac, and larger hernia defect. The total operative time also was increased (p < 0.05) with incarcerated hernia contents. Mesh placement time was increased (p < 0.05) with incarcerated hernia contents, suprapubic hernia location, hernias requiring larger mesh for repair, and decreased postgraduate year of the surgical assistant. The time required to obtain abdominal access was longer (p < 0.05) with a greater BMI and a higher American Society of Anesthesiology (ASA) classification. The operative times were not increased with a history of peritonitis, diabetes, immunosuppression, cancer, or with higher numbers of previous open or laparoscopic surgeries., Conclusions: At least 10 preoperatively identifiable patient variables, either alone or in combination, are predictive of prolonged operative times during laparoscopic ventral hernia repair and may be used as surrogates to determine the complexity of a minimally invasive approach.

Introduction: Ligamentous attachments maintain the normal anatomic position of the gastroesophageal (GE) junction. Failure of these elastic ligaments through an alteration in collagen synthesis, deposition, and metabolism may be a primary etiology of hiatal hernia formation. Differential expression of zinc-dependent matrix metalloproteinases (MMPs) is largely responsible for collagen remodeling. The purpose of this study was to survey baseline levels of MMPs in supporting ligaments of the GE junction from patients without hiatal hernia., Methods: Following an institutional review board-approved protocol, plasma and tissue biopsies of the gastrohepatic ligament (GHL), gastrophrenic ligament (GPL), and phrenoesophageal ligament (PEL) were obtained in six patients without a hiatal hernia during laparoscopic anterior esophageal myotomy for achalasia. Total protein extracts from tissue biopsies were analyzed for elastases MMP-2, -9, and -12 and collagenases MMP-1, -3, -7, -8, and -13 using a multiplex profiling kit (R&D Systems, Minneapolis, MN). Data are reported as mean +/- standard deviation. Statistical significance (p < 0.05) was determined using Tukey's test and analysis of variance., Results: In control patients without hiatal hernias, increased levels of MMP-2 (p < 0.02) were detected in the GHL compared with the GPL and PEL, respectively. Tissue levels of MMP-1, -12, and -13 were not detectable., Conclusions: Gelatinase-A (MMP-2) is present in the GHL and plasma of control patients. The GHL may provide the primary GE junction supporting ligament to compare tissue from patients with type I (sliding) and type III (paraesophageal) hiatal hernias to examine the role of altered collagen metabolism in hiatal hernia formation.

Background: Our aim was to investigate the views of major religions and cultural groups regarding the use of allogeneic and xenogeneic mesh for soft tissue repair., Study Design: We contacted representatives from Judaism, Islam, Buddhism, Hinduism, Scientology, and Christianity (Baptists, Methodists, Seventh-Day Adventists, Catholics, Lutherans, Church of Jesus Christ of Latter-Day Saints, Evangelical, and Jehovah's Witnesses). We also contacted American Vegan and People for the Ethical Treatment of Animals (PETA). Standardized questionnaires were distributed to the religious and cultural authorities. Questions solicited views on the consumption of beef and pork products and the acceptability of human-, bovine-, or porcine-derived acellular grafts., Results: Dietary restrictions among Jews and Muslims do not translate to tissue implantation restriction. Approximately 50% of Seventh-day Adventists and 40% of Buddhists practice vegetarianism, which may translate into a refusal of the use of xenogeneic tissue. Some Hindus categorically prohibit the use of human tissue and animal products; others allow the donation and receipt of human organs and tissues. PETA is opposed to all uses of animals, but not to human acellular grafts or organ transplantation. Some vegans prefer allogeneic to xenogeneic tissue. Allogeneic and xenogeneic acellular grafts are acceptable among Scientologists, Baptists, Lutherans, Evangelicals, and Catholics. Methodists, Jehovah's Witnesses, and The Church of Jesus Christ of Latter-Day Saints leave the decision up to the individual., Conclusions: Knowledge of religious and cultural preferences regarding biologic mesh assists the surgeon in obtaining a culturally sensitive informed consent for procedures involving acellular allogeneic or xenogeneic grafts., (Copyright (c) 2010 American College of Surgeons. Published by Elsevier Inc. All rights reserved.)