An Evaluation of Tension Measurements During Myofascial Release for Hernia Repair.

Tension-free repairs have revolutionized the way we repair hernias. To help reduce undue tension when performing ventral hernia repair, multiple different techniques of myofascial releases have been described. The purpose of this project is to evaluate tension measurements for commonly performed myofascial releases in abdominal wall hernia repair. Patients undergoing myofascial release techniques for their ventral hernias were enrolled in a prospective Institutional Review Board-approved protocol to measure abdominal wall tension from June 1, 2011 to August 1, 2019. Abdominal wall tensions were measured using tensiometers before and after myofascial release techniques. Descriptive statistics were performed and data were analyzed. Thirty patients had tension measurements (5 anterior myofascial separation, 25 posterior myofascial separation with transversus abdominis release [TAR]). Average age was 60.1 years (range 29-81), 83% Caucasian, 53% female, and 42% recurrent hernias. The average hernia defect in patients undergoing anterior myofascial release was 117.3 cm2, and the average mesh size was 650 cm2. The reduction in tension after anterior release was 4.7 lbs (2.7 lbs vs 7.4 lbs). The average hernia defect in patients undergoing posterior myofascial release (TAR) was 183 cm2, and the average mesh size was 761.36 cm2. The reduction in tension after bilateral posterior rectus sheath incision was 2.55 lbs (5.01 lbs vs 7.56 lbs) with 0.66 lbs further reduction in tension after TAR (4.35 lbs vs 5.01). In this evaluation, abdominal wall tension measurements are shown to be a feasible adjunct during open hernia repair. Preliminary data show tension reductions associated with the different myofascial release techniques and, with further study, may be a useful intraoperative adjunct for decision making in hernia repair.

A retrospective, Italian multicenter study of complex abdominal wall defect repair with a Permacol biological mesh.

Complex abdominal wall defects (CAWDs) can be difficult to repair and using a conventional synthetic mesh is often unsuitable. A biological mesh might offer a solution for CAWD repair, but the clinical outcomes are unclear. Here, we evaluated the efficacy of a cross-linked, acellular porcine dermal collagen matrix implant (Permacol) for CAWD repair in a cohort of 60 patients. Here, 58.3% patients presented with a grade 3 hernia (according to the Ventral Hernia Working Group grading system) and a contaminated surgical field. Permacol was implanted as a bridge in 46.7%, as an underlay (intraperitoneal position) in 38.3% and as a sublay (retromuscolar position) in 15% of patients. Fascia closure was achieved in 53.3% of patients. The surgical site occurrence rate was 35% and the defect size significantly influenced the probability of post-operative complications. The long-term (2 year) hernia recurrence rate was 36.2%. This study represents the first large multi-centre Italian case series on Permacol implants in patients with a CAWD. Our data suggest that Permacol is a feasible strategy to repair a CAWD, with acceptable early complications and long-term (2 year) recurrence rates.

Physiologic Tension: Technique for Measuring and Baseline Values.

Tension is one of the most discussed terms related to hernia surgery and repair. Despite the universally accepted opinion that tension and reduction of tension are important concepts in hernia repair, there is very little known about the physiologic tension of the abdominal wall related to ventral hernia repair. The purpose of this project was to attempt to measure physiologic tension in patients without hernia repair and help determine a normal baseline tension. Patients were enrolled in a prospective institutional review board-approved protocol to measure abdominal wall tension from February 2014 to present. Patients undergoing abdominal surgery without hernia repair were included. Demographic information and operative details were documented. Abdominal wall tensions were measured using scales attached to Kocher clamps that are clamped to the fascia and then brought together in the midline. Total tension, surgeon's estimation of tension, and grading of the fascia were recorded. Descriptive statistics were calculated. Eleven patients met the inclusion criteria and had tension measurements performed during surgery. The average age was 58 years, with 55 per cent of them being white and 82 per cent being male, with an average BMI of 27. Operations included exploratory laparotomy for small bowel pathology in six patients, colorectal surgery in three patients, and splenectomy in a trauma patient. Average tension measurements for these patients were 1.9 lbs. Surgeon grading of tension was an average of 2.2 (range, 1-5). Obtaining tension measurements is feasible during abdominal surgery. Physiologic tension seems to be approximately 2 pounds. Further study is needed with a larger sample of patients.

A Preliminary Assessment of Abdominal Wall Tension in Patients Undergoing Retromuscular Hernia Repair.

A common technique for ventral and incisional hernia repair is the retrorectus repair (Rives-Stoppa). The posterior rectus sheath is incised bilaterally, and mesh is placed retromuscularly. There is little information on how this component separation technique affects abdominal wall tension. We evaluated abdominal wall tension in patients undergoing retrorectus repair of abdominal wall hernias. Patients undergoing retrorectus repair of their ventral hernias were enrolled in a prospective, Institutional Review Board-approved protocol to measure abdominal wall tension from 8/1/2013 to 8/2/2017. Demographic information and operative details were documented. Abdominal wall tensions were measured using scales attached to Kocher clamps that were clamped to the fascia and brought together in the midline. Measurements were made before and after incising the posterior rectus sheaths. Data were analyzed with a repeated measures analysis of variance (ANOVA), and differences between individual groups were analyzed by least square differences. Forty-five patients had tension measurements. Average age was 58 years (range 29-81)-78% Caucasian, 51% female, an average body mass index (BMI) of 35 kg/m2 (range 20-62), and 38% recurrent hernias. The average hernia defect was 121.9 cm2, and the average mesh size was 607.8 cm2. There was a significant reduction in tension after bilateral posterior rectus sheath incision (3.1 lbs vs. 5.6 lbs, p<0.0001). In this evaluation, abdominal wall tension measurements are shown to be a feasible adjunct during open hernia repair with retrorectus repair. Transection of the posterior rectus sheath decreases tension during hernia repair and may help guide surgeons regarding when to use this procedure.

Effect of transversus abdominis release on core stability: Short-term results from a single institution.

INTRODUCTION: Transversus abdominis release is an increasingly used procedure in complex abdominal wall reconstruction. The transversus abdominis muscle is a primary stabilizer of the spine, yet little is known regarding the effect of transversus abdominis release on core stability, back pain, or hernia-specific quality of life. The purpose of our study was to investigate the effect of complex abdominal wall reconstruction using transversus abdominis release on patient quality of life and core stability function. METHODS: All patients undergoing complex abdominal wall reconstruction requiring transversus abdominis release from June 2016 through October 2016 at our institution were eligible for study inclusion. Back and hernia quality-of-life measures, including the Quebec Back Pain Scale and the Hernia Quality of Life Survey (HerQLes), in addition to patient core stability, as measured using the prone test and the Sahrmann Core Stability Test, were collected at the preoperative evaluation and at 6 months after surgery. Student's t test was used to determine the effect of complex abdominal wall reconstruction on quality of life and core stability. RESULTS: Twenty-one patients completed the preoperative and 6-month postoperative evaluations. Back pain scores significantly improved postoperatively overall and in each of the 6 subcategories measured using the Quebec Back Pain Scale (P = .001). There was also a statistically significant improvement in abdominal wall function as reflected by Hernia Quality of Life Survey scores (P < .001). There was no statistically significant difference in core stability as reflected in the average prone score (P = .6) or the Sahrmann Core Stability Test average score (P = .4). CONCLUSION: Abdominal wall reconstruction with transversus abdominis release leads to improved back pain and hernia quality of life and does not appear to negatively affect core stability in the short term.

Sublay repair results in superior mesh incorporation and histological fibrogenesis in comparison to onlay and primary suture in an experimental rat model.

PURPOSE: To compare adhesion scores, repair strength and histological findings among sublay, onlay and primary repair incisional hernioplasty techniques. Surgical repairs were employed directly on healthy animals, without previous hernia induction, to avoid confounding factors related to hernia development. METHODS: Forty Wistar rats were divided into four groups, control, simulation, onlay and sublay. After 42 days, adhesion intensity, tensile strength of the abdominal wall and anatomopathological histological substrate were compared. RESULTS: SL group presented greater adhesion scores (p < 0.0001), higher tensiometric (p < 0.0001), and was characterized by more histiocytes, mononuclear cells, macrovacuolar granulomas and type I collagen on histological analysis. Pearson correlation between adhesions and tensiometry, and between tensiometry and neocollagenization showed a strong positive association (r = 0.8905 and 0.6757, respectively in SL group, p < 0.05). CONCLUSION: Mesh positioning in sublay compartment was followed by increased adhesion development and provides a stronger mesh-tissue attachment, in addition, resulted in a different histological profile of the inflammation/repair substrate. The intensity of these findings was directly correlated, suggesting they could be the result of a common biological phenomenon. Our findings indicate that mesh placement following the retromuscular technique generates a superior repair response, and give clues to a better understanding of the superiority of sublay repair in achieving lower recurrence rates. Characterization of the cellular and molecular elements responsible for the superiority of this technique is in our view an essential prerequisite aiming for improvements in the therapeutic options for the treatment of this disease.

Sarcopenia and outcomes in ventral hernia repair: a preliminary review.

PURPOSE: Sarcopenia, or loss of muscle mass, is associated with increased morbidity and mortality in oncologic resections and several other major surgeries. Complex ventral hernia repairs (VHRs) and abdominal wall reconstruction are often performed in patients at high risk for morbidity and recurrence, though limited data exist on outcomes related to sarcopenia. We aimed to determine if sarcopenia is associated with worse outcomes in patients undergoing VHR. METHODS: We reviewed patients undergoing VHRs from 2014 to 2015. Preoperative CT images were analyzed for cross-sectional muscle mass. Patients with and without sarcopenia underwent statistical analysis to evaluate differences in perioperative morbidity and hernia recurrence. Muscle indices were analyzed independently for outcomes. RESULTS: 135 patients underwent VHR with/without fistula takedown, staged repairs or other concomitant procedures. 27% had sarcopenia (age 34-84, BMI 27-33, 62% male). Postoperative complications occurred in 43% of sarcopenic patients and 47% of non-sarcopenic patients (p = 0.70). Surgical site infections (SSI) were seen in 16% of sarcopenic patients compared to 29% without sarcopenia (p = 0.14). There was no difference in hernia recurrence between groups (p = 0.90). However, after adjusting for diabetes and BMI, a 10 cm2/m2 decrease in muscle index had 1.44 OR of postoperative complications (p < 0.05). CONCLUSIONS: Though prevalent in our population, sarcopenia was not associated with an increase in postoperative complications, surgical site occurences/infections,  or hernia recurrence when previously published oncologic sarcopenia cutoffs were utilized. Previously established sarcopenia outcomes in malignancy may be attributable to an altered metabolic state that is not present in hernia repair patients. Larger-scale studies are recommended to establish new sarcopenia cutoffs for VHRs.

Clinical outcomes after parastomal hernia repair with a polyester monofilament composite mesh: a cohort study of 79 consecutive patients.

PURPOSE: Different techniques and mesh materials are used in parastomal hernia repair with recently reported recurrence rates ranging from 10 to 28%. The aim of this cohort study was to examine the risk of recurrence and chronic pain after Sugarbaker or keyhole parastomal hernia repair with intraperitoneal placement of a polyester monofilament macroporous composite mesh. METHODS: Data on all patients undergoing parastomal hernia repair with Parietex™ Composite Parastomal Mesh at our institution during a 4-year period were examined. Patients with urostomy were excluded. A team of three experienced surgeons performed all repairs. Follow-up including physical examination was done after 10 days, 6 and 12 months, and hereafter as annual structured telephone interviews. Patients suspected of hernia recurrence were offered computed tomography scan. Chronic pain was defined as pain requiring out-patient visit(s) and/or regular use of analgesics. RESULTS: 79 patients (Sugarbaker, n = 69; keyhole, n = 10) were included. Of those, 72 procedures were performed laparoscopically and seven by open technique. Two patients were reoperated within 30 days with removal of the mesh. In total, seven (9%) patients had parastomal hernia recurrence (reoperation, n = 3; conservative management, n = 4) during follow-up of median 12 months (range 0-49 months). In univariable logistic analyses, type of stoma was associated with recurrence (ileostomy 28% vs colostomy 3%, p = 0.007). Three patients (4%) reported chronic pain. CONCLUSION: In this study, we found low rates of recurrence and chronic pain following parastomal hernia repair using intraperitoneal reinforcement with a polyester monofilament composite mesh.

Development of a critical-sized ventral hernia model in the pig.

BACKGROUND: The pig is commonly used as a preclinical model for ventral hernia repair. However, no study has verified that an unrepaired surgically induced hernia (control) in the pig does not heal spontaneously but rather develops a persistent hernia. Without such verification in any given model, one cannot draw conclusions on the efficacy of the repair technique investigated. MATERIALS AND METHODS: Three surgically induced hernia models with increasing severity were created in eight pigs. These included 10-cm retrorectus partial-thickness (model 1) and 15-cm preperitoneal full-thickness (model 2) incisional defects and an 8 × 8 cm preperitoneal full-thickness excisional defect (model 3). Postoperative management included use of an abdominal binder, and in some cases, suction drainage, for 2 wk to support the repair and prevent seroma. Models were evaluated for persistence of hernia at 5 wk using clinical and radiographic assessments. RESULTS: All pigs developed clinical hernias after 2 wk of defect creation, but only models 1 and 3 had clinically persistent hernias at 5 wk. At 5 wk, the average defect area was 97 cm2 in model 1, 66 cm2 in model 2, and 245 cm2 in model 3. Dense fibrotic scarring was observed in the models with resolved hernias. CONCLUSIONS: Our results highlight the need to verify an unrepaired hernia injury model does not heal spontaneously prior to using it for hernia repair studies. The partial-thickness incisional model 1 and full-thickness excisional model 3 formed persistent hernias in pigs at 5 wk and should be further explored as models for investigating hernia repair strategies.

Cross-linking of porcine acellular dermal matrices negatively affects induced neovessel formation using platelet-rich plasma in a rat model of hernia repair.

The degree of cross-linking within acellular dermal matrices (ADM) seems to correlate to neovascularization when used in ventral hernia repair (VHR). Platelet-rich plasma (PRP) enhances wound healing through several mechanisms including neovascularization, but research regarding its effect on soft tissue healing in VHR is lacking. We sought to study the effect of cross-linking on PRP-induced neovascularization in a rodent model of bridging VHR. We hypothesized that ADM cross-linking would negatively affect PRP-induced neovessel formation. PRP was extracted and characterized from pooled whole blood. Porcine cross-linked (cADM) and non-cross-linked ADMs (ncADM) were implanted in a rat model of chronic VHR after treatment with saline (control) or PRP. Neovascularization of samples at 2, 4, and 6 weeks was assessed by hematoxylin and eosin and immunohistochemical staining of CD 31. Adhesion severity at necropsy was compared using a previously validated scale. Addition of PRP increased neovascularization in both cADM and ncADM at 2- and 4-week time points but appeared to do so in a dependent fashion, with significantly greater neovascularization in the PRP-treated ncADMs compared to cADMs. Omental adhesions were increased in all PRP-treated groups. Results indicate that, for 2-week measurements when compared with the cADM group without PRP therapy, the mean change in neovascularization due to ncADM was 3.27 (Z = 2.75, p = 0.006), PRP was 17.56 (Z = 14.77, p < 0.001), and the combined effect of ncADM and PRP was 9.41 (Z = 5.6, p < 0.001). The 4-week data indicate that the average neovascularization change due to ncADM was 0.676 (Z = 0.7, p = 0.484), PRP was 7.69 (Z = 7.95, p < 0.001), and combined effect of ncADM and PRP was 5.28 (Z = 3.86, p < 0.001). These findings validate PRP as a clinical adjunct to enhance the native tissue response to implantable biomaterials and suggest that ncADM is more amenable than cADM to induced neovascularization. PRP use could be advantageous in patients undergoing VHR where poor incorporation is anticipated and early-enhanced neovascularization is desired.

Symptom load and individual symptoms before and after repair of parastomal hernia: a prospective single centre study.

AIM: The symptom load and individual symptoms before and after repair of parastomal hernia were investigated. METHOD: Stoma-related symptoms were prospectively recorded before repair of a parastomal hernia and at 10 days and 6 months postoperatively: leakage, skin problems, difficulty with the appliance, limitation of activity, difficulty with clothing, cosmetic complaints, social restriction, erratic action of the stoma, a bearing-down sensation at the site of the stoma and pain. Episodes of intermittent bowel obstruction and difficulty with irrigation were also recorded. Patients were seen at 1, 2 and 3 years and were examined for recurrent parastomal herniation. RESULTS: Of 131 consecutive patients referred to a specialized centre for treatment of parastomal bulging, 61 underwent parastomal hernia repair. Forty-eight patients were treated with the Sugarbaker technique. Six different symptoms were present in more than half the patients before surgery. The overall symptom load decreased significantly from a median of 4 [interquartile range (IQR) 2.5-6] preoperatively to 2 (IQR 1-3) on postoperative day 10 and 1 (IQR 0-2) at 6 months, P < 0.001. The number of symptoms decreased in 93% of patients; in 5% there was no change and in 2% symptoms increased. Skin problems and leakage were the only symptoms that were not significantly reduced. The overall recurrence rate of herniation was 5/48 (10%) at a median of 12 (IQR 6-24) months. CONCLUSION: The preoperative symptom load was high and this fell after repair in over 90% of patients. Recurrence occurred in 10% of patients within 2 years of repair. The study emphasizes the importance of detailed knowledge of the symptoms of parastomal hernia when addressing and managing patients' problems and complaints.

Abdominal wall reinforcement: biologic vs. degradable synthetic devices.

BACKGROUND: New biodegradable synthetic and biologic hernia implants have been promoted for rapid integration and tissue reinforcement in challenging repairs, e.g. at the hiatus or in contaminated wound fields. Interestingly, experimental data to support or falsify this assumption is scarce. METHODS: Synthetic (BioA®) and biologic implants (porcine and bovine collagen matrices Strattice® and Veritas®) have been tested in experimental onlay hernia repair in rats in observation periods of 30 and 60 days. The key outcome parameters were mesh integration and reinforcement of the tissue at the implant site over sutured and sealed defects as well as comparison to native abdominal wall. Macroscopic assessment, biomechanical analysis and histology with haematoxylin/eosin staining, collagen staining and van Willebrand factor staining for detection of neovascularization were performed. RESULTS: BioA® was well integrated. Although the matrices were already fragmented at 60 days follow-up, hernia sites treated with synthetic scaffolds showed a significantly enhanced tissue deflection and resistance to burst force when compared to the native abdominal wall. In porcine and bovine matrices, tissue integration and shrinkage were significantly inferior to BioA®. Histology revealed a lack of fibroblast ingrowth through mesh interstices in biologic samples, whereas BioA® was tightly connected to the underlying tissue by reticular collagen fibres. CONCLUSIONS: Strattice® and Veritas® yielded reduced tissue integration and significant shrinkage, prohibiting further biomechanical tests. The synthetic BioA® provides little inherent strength but reticular collagen remodelling led to an augmentation of the scar due to significantly higher burst force resistance in comparison to native tissue.

Clinical and Patient-Reported Outcomes after Absorbable Strap Fixation for Ventral Hernia Repair.

INTRODUCTION: Various mesh fixation methods are employed by surgeons during ventral hernia repair. These may include tacks, straps, sutures, glue, or a combination of methods. One of these choices is an absorbable fixation device, Securestrap® (Ethicon Inc., Somerville, New Jersey), consisting of an absorbable copolymer barbed U-shaped strap with a spring-loaded deployment system. MATERIALS AND METHODS: The International Hernia Mesh Registry is a prospective multi-center registry, designed to collect longitudinal data on hernia repair methods, products, and outcomes. Patients complete the Carolinas Comfort Scale™ (CCS) (The Charlotte-Mecklenburg Hospital Authority, Charlotte, North Carolina) pre-operatively, and at one month, six months, and 12 months post-operatively. Symptomatic patients defined as responding >1 to any CCS™ question. Statistical comparison of symptom frequency was made with the McNemar test and Kaplan Meier methods to determine the recurrence rate up to 365 days. RESULTS: Patients were enrolled at 16 centers. Data was available on 100 of the 203 patients at six months and on 119 patients at 12 months. Demographics: mean age of 52.7 (13.2 standard deviation[ SD]); mean body mass index (BMI) of 33.2 (7.5 SD) kg/m2; 64.3% having a BMI over 30kg/m2; male patients 47.4%; 16.7% for recurrent hernias. Mesh fixation with straps alone in 48.3% of cases or straps and sutures in 51.7% of cases. Percentage of patients with symptomatic pain decreased slightly from baseline to one month (70.0 vs. 60.6, p=0.0782) and significantly from one month to six months (60.6% symptomatic vs. 23.2%; p=0.0004). From six months to twelve months, the change in percentage of symptomatic patients was not significant (23.2% vs. 28.7%; p=0.8084). Similar results were observed with symptomatic CCS™ movement limitations. Overall recurrence rate at 12 months was 4.72% (2.39%-9.22%). CONCLUSION: Mesh fixation with straps with or without additional sutures is associated with significant improvements in patient-reported pain and movement limitation from baseline to six months post-operative.

Giant ventral hernia-relationship between abdominal wall muscle strength and hernia area.

BACKGROUND: Symptoms arising from giant ventral hernia have been considered to be related to weakening of the abdominal muscles. The aim of this study was to investigate the relationship between the area of the abdominal wall defect and abdominal wall muscle strength measured by the validated BioDex system together with a back/abdominal unit. METHODS: Fifty-two patients with giant ventral hernia (>10 cm wide) underwent CT scan, clinical measurement of hernia size and BioDex measurement of muscle strength prior to surgery. The areas of the hernia derived from CT scan and from clinical measurement were compared with BioDex forces in the modalities extension, flexion and isometric contraction. The Spearman rank test was used to calculate correlations between area, BMI, gender, age, and muscle strength. RESULT: The hernia area calculated from clinical measurements correlated to abdominal muscle strength measured with the Biodex for all modalities (p-values 0.015-0.036), whereas no correlation was seen with the area calculated by CT scan. No relationship was seen between BMI, gender, age and the area of the hernia. DISCUSSION: The inverse correlation between BioDex abdominal muscle strength and clinically assessed hernia area, seen in all modalities, was so robust that it seems safe to conclude that the area of the hernia is an important determinant of the degree of loss of abdominal muscle strength. Results using hernia area calculated from the CT scan showed no such correlation and this would seem to concur with the results from a previous study by our group on patients with abdominal rectus diastasis. In that study, defect size assessed clinically, but not that measured by CT scan, was in agreement with the size of the diastasis measured intra-operatively. The point at which the area of a hernia begins to correlate with loss of abdominal wall muscle strength remains unknown since this study only included giant ventral hernias.

[HERNIOPLASTIC MORFOLOGICAL FEATURES (EXPERIMENTAL STADY)].

Despite many years of experience in the field of hernia surgical treatment there still exist many unsolved problems such as a safe and non infected closure of defects of abdominal cavity wall. The aim of the study was to improve the result of treatment of abdominal wall hernias with the use of new antiseptic polymer, bio-composite protective mesh membrane covered with coladerm+chlorhexidine. Experimental study involved 21 rabbits. Meshes were fixed on anterior abdominal wall according to the following schewe: Option I: mesh size 10-20mm was put into both the groin area of the rabbits. Option II: A light standart mesh grid size 10-20mm covered with coladerm was placed on both sides of abdominal wall of the rabbits. Option III: A light mesh, covered with oladerm+Chlorhexidine was placed in to the abdominal wall of the rabbits. Removal dates of taking the animals from experiments were 14th, 30th, 45th, 90th and 180th days for further histomorpological and bacteriological research. The best result from these options was when implants we covered with coladerm+Chlorhexidine, which was shown on follow up period. In third control group experessed strong connective tissue formatting stromis picture,wich is the main task of modern hernia plastic. It is expected that new bio-composite meshes, covered with coladerm+Chlorhexidine, may be succesfuly used in clinical practice, which will reduce infectious complications of meshes and problems associated with them.

Experimental study of inflammatory response and collagen morphometry with different types of meshes.

PURPOSE: To compare an inflammation score and collagen morphometry after incisional hernia repair with four different meshes at two time points. METHODS: Four types of mesh were used to repair an abdominal wall incisional defect in Wistar rats: high-density polypropylene (HW/PP); low-density polypropylene (LW/PP); polypropylene mesh encapsulated with polydioxanone coated with oxidized cellulose (PP/CE); and expanded polytetrafluoroethylene (ePTFE). An inflammation score based on histological analysis and collagen morphometry was performed after 7 and 28 days after operation (POD). RESULTS: Compared to LW/PP group at 7 POD, HW/PP group had lower (p = 0.014) and PP/CE group had higher inflammation scores (p = 0.001). At 28 POD, higher scores were seen in all the other groups compared to the LW/PP group (HW/PP, p = 0.046; PP/CE, p < 0.001; ePTFE, p = 0.027). Comparing groups individually at 7 and 28 PODs, all demonstrated lower inflammation score values at 28 POD (HW/PP, p < 0.001; LW/PP, p < 0.001; PP/CE, p = 0.002; ePTFE, p = 0.001). At 7 POD, higher amounts of collagen were detected in ePTFE compared to HW/PP (p < 0.001) and LW/PP (p = 0.004) and in PPCE group compared to HW/PP (p = 0.022). At 28 POD, no statistically significant difference was found. Comparing groups individually at 7 and 28 PODs, HW/PP and LW/PP showed larger amounts of collagen at the 28th POD, without any statistically significant differences for the PP/CE and ePTFE groups. CONCLUSIONS: Inflammation scores decreased in all groups at 28 POD. Collagen deposition was higher for non-composite meshes at 28 POD.

Isometric abdominal wall muscle strength assessment in individuals with incisional hernia: a prospective reliability study.

PURPOSE: To determine the reliability of measurements obtained by the Good Strength dynamometer, determining isometric abdominal wall and back muscle strength in patients with ventral incisional hernia (VIH) and healthy volunteers with an intact abdominal wall. METHODS: Ten patients with VIH and ten healthy volunteers with an intact abdominal wall were each examined twice with a 1 week interval. Examination included the assessment of truncal flexion and extension as measured with the Good Strength dynamometer, the completion of the International Physical Activity Questionnaire (IPAQ) and the self-assessment of truncal strength on a visual analogue scale (SATS). The test-retest reliability of truncal flexion and extension was assessed by interclass correlation coefficient (ICC), and Bland and Altman graphs. Finally, correlations between truncal strength, and IPAQ and SATS were examined. RESULTS: Truncal flexion and extension showed excellent test-retest reliability for both patients with VIH (ICC 0.91 and 0.99) and healthy controls (ICC 0.97 and 0.96). Bland and Altman plots showed that no systematic bias was present for neither truncal flexion nor extension when assessing reliability. For patients with VIH, no significant correlations between objective measures of truncal strength and IPAQ or SATS were found. For healthy controls, both truncal flexion (τ 0.58, p = 0.025) and extension (τ 0.58, p = 0.025) correlated significantly with SATS, while no other significant correlation between truncal strength measures and IPAQ was found. CONCLUSIONS: The Good Strength dynamometer provided a reliable, low-cost measure of truncal flexion and extension in patients with VIH.

Living scaffolds: surgical repair using scaffolds seeded with human adipose-derived stem cells.

BACKGROUND: Decellularized porcine small intestinal submucosa (SIS) is a biological scaffold used surgically for tissue repair. Here, we demonstrate a model of SIS as a scaffold for human adipose-derived stem cells (ASCs) in vitro and apply it in vivo in a rat ventral hernia repair model. STUDY DESIGN: ASCs adherence was examined by confocal microscopy and proliferation rate was measured by growth curves. Multipotency of ASCs seeded onto SIS was tested using adipogenic, chondrogenic, and osteogenic induction media. For in vivo testing, midline abdominal musculofascial and peritoneal defects were created in Sprague-Dawley rats. Samples were evaluated for tensile strength, histopathology and immunohistochemistry. RESULTS: All test groups showed cell adherence and proliferation on SIS. Fibronectin-treated scaffolds retained more cells than those treated with vehicle alone (p < 0.05). Fresh stromal vascular fraction (SVF) pellets containing ASCs were injected onto the SIS scaffold and showed similar results to cultured ASCs. Maintenance of multipotency on SIS was confirmed by lineage-specific markers and dyes. Histopathology revealed neovascularization and cell influx to ASC-seeded SIS samples following animal implantation. ASC-seeded SIS appeared to offer a stronger repair than plain SIS, but these results were not statistically significant. Immunohistochemistry showed continued presence of cells of human origin in ASC-seeded repairs at 1 month postoperation. CONCLUSION: Pretreatment of the scaffold with fibronectin offers a method to increase cell adhesion and delivery. ASCs maintain their immunophenotype and ability to differentiate while on SIS. Seeding freshly isolated SVF onto the scaffold demonstrated that minimally manipulated cells may be useful for perioperative surgical applications within the OR suite. We have shown that this model for a "living mesh" can be successfully used in abdominal wall reconstruction.