The use of a subfascial vicryl mesh buttress to aid in the closure of massive ventral hernias following damage-control laparotomy

The Association of Coloproctology of Great Britain and Ireland consensus guidelines in emergency colorectal surgery

AIM

There is a requirement for an expansive and up to date review of the management of emergency colorectal conditions seen in adults. The primary objective is to provide detailed evidence-based guidelines for the target audience of general and colorectal surgeons who are responsible for an adult population and who practise in Great Britain and Ireland.

METHODS

Surgeons who are elected members of the Association of Coloproctology of Great Britain and Ireland Emergency Surgery Subcommittee were invited to contribute various sections to the guidelines. They were directed to produce a pathology-based document using literature searches that were systematic, comprehensible, transparent and reproducible. Levels of evidence were graded. Each author was asked to provide a set of recommendations which were evidence-based and unambiguous. These recommendations were submitted to the whole guideline group and scored. They were then refined and submitted to a second vote. Only those that achieved >80% consensus at level 5 (strongly agree) or level 4 (agree) after two votes were included in the guidelines.

RESULTS

All aspects of care (excluding abdominal trauma) for emergency colorectal conditions have been included along with 122 recommendations for management.

CONCLUSION

These guidelines provide an up to date and evidence-based summary of the current surgical knowledge in the management of emergency colorectal conditions and should serve as practical text for clinicians managing colorectal conditions in the emergency setting.

Comparison of subpectoral versus dual-plane implant based immediate breast reconstruction after nipple-areola sparing mastectomy

BACKGROUND

Selection of implant pocket and size is a dilemma for surgeons especially if radiation therapy is envisaged after implant based immediate breast reconstruction (IBR). The aim of this study is to compare complication rates between subpectoral and the dual plane polyglactin mesh supported IBR after nipple-areola sparing mastectomy.

PATIENTS AND METHOD

Reconstructive analysis of 208 breasts of 190 patients with breast cancer undergoing implant based IBR at a single university hospital were evaluated. The patients were reconstructed with either dual-plane polyglactin mesh supported (n=91) or subpectoral (n=117) implant based IBR after nipple-areola sparing mastectomy. Demographic data, and postoperative complications were compared.

RESULTS

The mean age was 43.3 years. Early complications encountered in 12% (n=25) and late complications occurred in 18% (n=37) of breasts. Both early (13,7% vs 9.9%, P=0.406) and late complications (24.8% vs 8.8%, P=0.003) were more common in subpectoral group, but only late complication occurrence rate was statistically significant. Capsular contracture (P=0.000), inframammary fold problems (P=0.010), bottoming-out (P=0.370), mechanical shift (P=0.036) and animation deformity (P=0.007) were all more common in subpectoral group. Only rippling deformity (P=0.011) was more common in dual plane group.

CONCLUSIONS

Dual plane IBR has acceptable complication rates compared to subpectoral IBR. It is associated with less capsular contracture, fewer animation and bottoming-out deformity and better inframammary fold appearance.

Absorbable Polyglactin vs. Non-Cross-linked Porcine Biological Mesh for the Surgical Treatment of Infected Incisional Hernia

BACKGROUND

The use of absorbable meshes during contaminated or infected incisional hernia (IH) repair is associated with high morbidity and recurrence rates. Biological meshes might be more appropriate but have been described in highly heterogeneous series. This study aimed at comparing the efficacy of absorbable vs. biological meshes for the treatment of contaminated or infected IH in a homogeneous series with a standardized technique.

METHODS

Data of all patients operated on between 2008 and 2015 for contaminated or infected IH, using an absorbable (A) Vicryl® or a biological (B) Strattice® mesh, were reviewed. Patient characteristics, infectious complication rates, and recurrence-free outcome (RFO) were compared between the two groups. A propensity score methodology was applied to a Cox regression model to deal with unbalanced characteristics between groups.

RESULTS

Patient demographics in A (n = 57) and in B (n = 24) were similar except that B patients had larger parietal defects (p < 0.001) and higher Center for Disease Control (CDC) wound class (p = 0.034). Patients in A had statistically significantly more postoperative early (61.4% vs. 33.3%, p = 0.03) and late (31.2% vs. 8.3%, p = 0.046) infectious complications. Six-, 12-, and 36-month RFO rates were 77%, 47%, and 24%, and 96%, 87%, and 82% in A and B, respectively, p < 0.001. Raw multivariable Cox regression analysis found that B (HR = 0.1, 95% CI [0.03-0.34], p < 0.001) was independently associated with prolonged RFO (HR = 0.091, 95% CI [0.045-0.180], p < 0.001).

CONCLUSION

Biological meshes seem to be superior to absorbable meshes in patients with contaminated or infected incisional hernia. These results need to be confirmed by prospective randomized trials.

What Exactly is Meant by "Loss of Domain" for Ventral Hernia? Systematic Review of Definitions

Large ventral hernias are a significant surgical challenge. "Loss of domain" (LOD) expresses the relationship between hernia and abdominal volume, and is used to predict operative difficulty and success. This systematic review assessed whether different definitions of LOD are used in the literature. The PubMed database was searched for articles reporting large hernia repairs that explicitly described LOD. Two reviewers screened citations and extracted data from selected articles, focusing on the definitions used for LOD, study demographics, study design, and reporting surgical specialty. One hundred and seven articles were identified, 93 full-texts examined, and 77 were included in the systematic review. Sixty-seven articles were from the primary literature, and 10 articles were from the secondary literature. Twenty-eight articles (36%) gave a written definition for loss of domain. These varied and divided into six broad groupings; four described the loss of the right of domain, six described abdominal strap muscle contraction, five described the "second abdomen", five describing large irreducible hernias. Six gave miscellaneous definitions. Two articles gave multiple definitions. Twenty articles (26%) gave volumetric definitions; eight used the Tanaka method [hernia sac volume (HSV)/abdominal cavity volume] and five used the Sabbagh method [(HSV)/total peritoneal volume]. The definitions used for loss of domain were not dependent on the reporting specialty. Our systematic review revealed that multiple definitions of loss of domain are being used. These vary and are not interchangeable. Expert consensus on this matter is necessary to standardise this important concept for hernia surgeons.

Pros and cons of immediate Vicryl mesh insertion after lumpectomy

BACKGROUND

Lumpectomy is a standard surgery for breast cancer; however, it results in breast deformity, especially after radiation therapy. Wider surgical margin correlates lower local recurrence rate. However, bigger defect brings worse cosmetic outcome. The use of a simple filler for the defect is expected. We aimed to improve the cosmetic outcome by using an absorbable Vicryl mesh for breast reconstruction immediately post-lumpectomy.

METHODS

One sheet of Vicryl woven mesh was prepared for insertion, washed the cavity with natural saline, and placed into the space. The cosmetic outcome was scored for the size, shape, scar, and softness of the breast. The size, shape, color, and position of the nipple-areola complex were also scored. Adverse events were collected retrospectively.

RESULTS

From April 2008 to October 2014, 24 female patients received immediate Vicryl mesh insertion. A lumpectomy only group was recruited for cosmetic analysis. All patients received postsurgical radiotherapy. The mean cosmetic assessment score was 8.0 and 9.1 of 12 for the Vicryl mesh group and lumpectomy only group, respectively (P = 0.17). Sixteen patients had adverse events such as erythema at approximately 2 weeks post-surgery. No significant differences were shown except adverse events between two groups. No patient has had local recurrence thus far.

CONCLUSION

Immediate Vicryl mesh insertion leads to significantly increased incidence of postoperative complications and delay in commencement of adjuvant radiotherapy. Furthermore, the cosmetic outcomes are not superior to that of no reconstruction. The development of superior biomaterials is anticipated for breast reconstruction after lumpectomy.

Strength and histology of a nanofiber scaffold in rats

BACKGROUND

Full-thickness soft tissue defects from congenital absence or traumatic loss are difficult to surgically manage. Healing requires cell migration, organization of an extracellular matrix, inflammation, and wound coverage. PLCL (70:30 lactide:caprolactone, Purac), poly(propylene glycol) nanofibrous scaffolds enhance cell infiltration in vitro. This study compares strength and tissue ingrowth of aligned and unaligned nanofibrous scaffolds to absorbable and permanent meshes. We hypothesize that PLCL nanofibrous grafts will provide strength necessary for physiological function while serving as a scaffold to guide native tissue regeneration in vivo.

MATERIALS AND METHODS

Abdominal wall defects were created in 126 rats followed by underlay implantation of Vicryl, Gore-Tex, aligned, or unaligned PLCL Nanofiber mesh. Specimens were harvested at 2, 6, and 12 wk for strength testing and 2, 12, and 24 wk for histopathologic evaluation. Specimens were graded for cellular infiltration, multinucleated giant cells (MNG), vascularity, and tissue organization. Mean scores were compared and analyzed with non-parametric testing.

RESULTS

The PLCL grafts maintained structural integrity until at least 12 wk and exhibited substantial tissue replacement at 24 wk. At 12 wk, only the aligned PLCL had persistent cellular infiltration of the graft, whereas both aligned and unaligned PLCL grafts showed the presence of MNG. The presence of MNGs decreased in the aligned PLCL graft by 24 wk.

CONCLUSIONS

The aligned PLCL nanofiber mesh offers early strength comparable to Gore-Tex but breaks down and is replaced with cellular ingrowth creating a favorable option in management of complex surgical wounds or native soft tissue defects.

The use of Vicryl mesh in a porcine model to assess its safety as an adjunct to posterior fascial closure during retromuscular mesh placement

BACKGROUND

Posterior component separation has become a common approach to complex abdominal wall reconstructions. This technique includes creation of an extraperitoneal retromuscular space for subsequent large synthetic mesh reinforcement. In certain cases, when complete restoration of "posterior" layer is precluded by significant tissue loss/damage, one proposed strategy is to replace the posterior fascia with an absorbable synthetic polyglactin (Vicryl) mesh. However, the safety of this strategy to prevent mesh-related visceral complication is unknown. Herein, we aimed to characterize mesh-viscera adhesion profiles and host tissue response of synthetic mesh either exposed directly to the viscera, or protected with Vicryl mesh.

METHODS

Using adult Yorkshire pigs, 5 × 5 cm pieces of mesh were secured to the intact peritoneum in each of the four quadrants (n = 6 pigs, 24 mesh samples). The study groups were Vicryl (V), Marlex (M), Softmesh (S), Marlex + Vicryl construct (MV), Softmesh + Vicryl construct (SV). The self-made composite meshes were then implanted with the Vicryl side facing the exposed viscera. The pigs were survived for 60 days. At necropsy, grossly, the extent and tenacity of visceral adhesions were evaluated using established scales. Histologically, all specimens for fibrous encapsulation on the visceral surface of the mesh were reviewed by an experienced pathologist blind to meshes used.

RESULTS

At necropsy, all Vicryl meshes were completely resorbed. The mean adhesion and tenacity scores for M and MV were 1.8 and 1.1 (P > 0.05), 2.0 and 1.5 (P > 0.05), respectively; while the mean adhesion extent scores and tenacity scores for S and SV were 2.0 and 1.2 (P > 0.05), 2.0 and 1.7 (P > 0.05). No significant difference in adhesion extent and tenacity was observed between Synthetic and Vicryl composite mesh groups. Histologically, Marlex + Vicryl mesh and Softmesh + Vicryl mesh constructs had thicker fibrous capsules than the corresponding unprotected Marlex and Soft mesh implants. Furthermore, visceral adhesions in the composite groups were noted to be to the fibrous capsule and not synthetic mesh itself.

CONCLUSION

Utilization of the absorbable polyglactin (Vicryl) mesh as a separating layer between a synthetic mesh and intestines, did not reduce adhesions across various mesh types and composites. Histologically, however, a thick fibrous capsule replaced the Vicryl mesh and may be an important layer to prevent intestinal erosion into retromuscular synthetic meshes.

Defining surgical outcomes and quality of life in massive ventral hernia repair: an international multicenter prospective study

BACKGROUND

Our goal was to set criteria for massive ventral hernia and to compare surgical outcomes and quality of life after ventral hernia repair (VHR).

METHODS

The International Hernia Mesh Registry was queried for patients undergoing VHR from 2007 to 2013. Defect was categorized as massive if the width or length was greater than 15 cm or area greater than 150 cm(2). Massive VHR was compared to regular VHR.

RESULTS

A total of 878 patients underwent VHR: 436 open, 442 laparoscopic with 13 deaths (1.5%) and 45 hernia recurrences (5.1%). Of those, 158 patients (18%) met criteria for massive VHR. Massive VHR patients had longer length of stay (LOS) and operative time and more hematomas, wound infections, wound complications, and pneumonias (P < .05). On multivariate analysis, LOS was longer, and early postoperative pain and activity limitation were greater in massive VHRs (P < .01). Massive VHR in the laparoscopic approach resulted in greater long-term mesh sensation (P < .01).

CONCLUSIONS

VHR in massive hernias have increased rates of complications and longer LOS.

Vicryl mesh in expander/implant breast reconstruction: long-term follow-up in 38 patients

BACKGROUND

Acellular dermal matrix has proven to be a useful adjunct in tissue expander or direct-to-implant breast reconstruction. Although versatile, acellular dermal matrix adds considerable cost. Vicryl (polyglactin) mesh has an established track record in many fields of surgery, and is considerably less costly than acellular dermal matrix. This study examines the use and long-term follow-up of Vicryl mesh in breast reconstruction.

METHODS

Vicryl mesh was used in 46 breast reconstructions (38 patients; 35 immediate and three delayed). The mesh was used along the inframammary fold to maintain position of the inferior pectoral edge, and/or along the lateral border to maintain expander position and prevent lateral migration. Eight breasts received adjuvant radiation therapy.

RESULTS

Mean follow-up at the time of review was 43 months. In the nonirradiated group (38 breasts), there was one postoperative infection (2.6 percent), which required expander removal. In the irradiated group, there were three complications requiring expander removal (37.5 percent): two infections and one device exposure after irradiation. Significant malposition was not observed in any breast where Vicryl mesh was used, and no visible mesh remained at the time of implant placement. The incidence of symptomatic capsular contracture in nonirradiated breasts was 3.2 percent. At latest follow-up, nonirradiated breasts had an average Baker capsule grade of 1.1, compared with 1.5 in the irradiated group.

CONCLUSIONS

Vicryl mesh is an effective alternative to acellular dermal matrix in nonirradiated breast reconstruction and is available at approximately one-twentieth the cost. Acellular dermal matrix or full muscle coverage may be preferable in irradiated reconstructions.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Meniscal repair in vivo using human chondrocyte-seeded PLGA mesh scaffold pretreated with platelet-rich plasma

The objective of this study was to test the hypothesis that platelet-rich plasma (PRP) pretreatment on a poly-lactic-co-glycolic acid (PLGA) mesh scaffold enhances the healing capacity of the meniscus with human chondrocyte-seeded scaffolds in vivo, even when the seeded number of cells was reduced from 10 million to one million. A flexible PLGA mesh scaffold was pretreated with PRP using a centrifugal technique. One million human articular chondrocytes were seeded onto the scaffold by dynamic oscillation. After 7 days, scaffolds were placed between human meniscal discs and were implanted subcutaneously in nude mice for 6 weeks (n = 16/group). Fluorescence microscopy demonstrated uniform attachment of the chondrocytes throughout the scaffolds 24 h following seeding. Cell attachment analysis revealed a significantly increased number of chondrocytes on PRP-pretreated than non-treated scaffolds (p < 0.05). Field emission scanning electron microscopy revealed chondrocytes attached to the PRP-pretreated scaffolds interconnecting their cellular processes with the fibrin network at 24 h and day 7 of culture. Of the 16 constructs containing PRP-pretreated scaffolds implanted in mice, six menisci healed completely, nine healed incompletely and one did not heal. Histological results from the 16 control constructs containing non-treated scaffolds revealed that none had healed completely, four healed incompletely and 12 did not heal. The histological outcome between the groups was significantly different (p < 0.05). These findings suggest that human articular chondrocytes on PRP-pretreated PLGA mesh scaffolds demonstrate increased cell attachment and enhance the healing capacity of meniscus with a reduced number of seeding cells in a meniscal repair mouse model. Copyright © 2014 John Wiley & Sons, Ltd.

Damage control abdomen: single-stage reconstruction using a vicryl mesh buttress

PURPOSE

Damage control laparotomy has become an accepted approach for patients with life-threatening abdominal conditions. This method compromises fascial integrity creating functionally and aesthetically debilitating hernias. The purpose of this study is to present our technique and outcomes with these complex abdominal wall reconstructions.

METHODS

A retrospective review was conducted on 56 patients with previous damage control laparotomies who underwent elective single-stage abdominal wall reconstruction between 1999 and 2006. Mean age was 42 years. Reconstruction consisted of a double-layer, subfascial Vicryl mesh buttress, combined with components separation and rectus muscle turnover flaps. Hernia recurrence and function were evaluated by clinical examinations and telephone surveys.

RESULTS

The major etiologies of abdominal hernias were gunshot wounds, motor vehicle accidents or blunt trauma, and sepsis or perforated bowel. The mean abdominal wall defect was 865 cm, and the average interval time to definitive repair was 17 months. The average length of follow-up was 29 months. Most patients (88%) had successful repair of their abdominal wall, with no hernia recurrence. There were 7 cases of hernia. Of these, 2 cases were from reopening of abdomen because of compartment syndrome that was not repaired, 3 were small asymptomatic hernias for which patients elected not to undergo further repair. Other complications include superficial skin dehiscence, all of which healed secondarily with daily wound care 12% (7 patients) and abdominal compartment syndrome 7.1% (4 patients), resulting in 2 postoperative mortalities in the initial part of the series. There were no mesh exposures, seromas, or fistulas. In all, 29% or 52% of patients were reached by telephone. Of those, 90% surveyed and who worked full-time prior to injury returned to their jobs, and 92% were functioning at premorbid activity levels.

CONCLUSION

Massive abdominal hernia following damage control laparotomy poses a great challenge to the reconstructive surgeon. This patient population is at significant risk for mortality and morbidity. We believe the use of a Vicryl mesh buttress is an important adjunctive tool in complex abdominal wall reconstruction. Functional results are excellent with most returning to work and preinjury activity levels.

Characterization of the Mechanical Strength, Resorption Properties, and Histologic Characteristics of a Fully Absorbable Material (Poly-4-hydroxybutyrate-PHASIX Mesh) in a Porcine Model of Hernia Repair

Purpose. Poly-4-hydroxybutyrate (P4HB) is a naturally derived, absorbable polymer. P4HB has been manufactured into PHASIX Mesh and P4HB Plug designs for soft tissue repair. The objective of this study was to evaluate mechanical strength, resorption properties, and histologic characteristics in a porcine model. Methods. Bilateral defects were created in the abdominal wall of n = 20 Yucatan minipigs and repaired in a bridged fashion with PHASIX Mesh or P4HB Plug fixated with SorbaFix or permanent suture, respectively. Mechanical strength, resorption properties, and histologic characteristics were evaluated at 6, 12, 26, and 52 weeks (n = 5 each). Results. PHASIX Mesh and P4HB Plug repairs exhibited similar burst strength, stiffness, and molecular weight at all time points, with no significant differences detected between the two devices (P > 0.05). PHASIX Mesh and P4HB Plug repairs also demonstrated significantly greater burst strength and stiffness than native abdominal wall at all time points (P < 0.05), and material resorption increased significantly over time (P < 0.001). Inflammatory infiltrates were mononuclear, and both devices exhibited mild to moderate granulation tissue/vascularization. Conclusions. PHASIX Mesh and P4HB Plug demonstrated significant mechanical strength compared to native abdominal wall, despite significant material resorption over time. Histological assessment revealed a comparable mild inflammatory response and mild to moderate granulation tissue/vascularization.

Closed internal degloving associated with a thoracolumbar burst fracture: a case report

Internal degloving injuries are rare in association with thoracolumbar fractures. A high index of suspicion is warranted to identify and debride such lesions to prevent infection, which can be disastrous in the presence of spinal hardware. Whether such lesions should be routinely repaired is probably dependent on the extent of avulsion.

Controversies in the care of the enterocutaneous fistula

Enterocutaneous fistula and its variations are some of the most difficult problems encountered in the practice of general surgery. Reliable evidence that can be used to direct the care of patients afflicted with this malady is limited. There are controversies in several areas of care. This article addresses some of the gray areas of care for the patient with enterocutaneous fistula. There is particular attention directed toward the phenomenon of enteroatmospheric fistula, as well as prevention and abdominal wall reconstruction, which is often required in these individuals.

Development of novel electrospun absorbable polycaprolactone (PCL) scaffolds for hernia repair applications

INTRODUCTION

Permanent/nonresorbable hernia repair materials rely on profibrotic wound healing, and repair sites are commonly composed of disorganized tissue with inferior mechanical strength and risk of reherniation. Resorbable electrospun scaffolds represent a novel class of biomaterials, which may provide a unique platform for the design of advanced soft tissue repair materials. These materials are simple, inexpensive, nonwoven materials composed of polymer fibers that readily mimic the natural extracellular matrix. The primary goal of the present study was to evaluate the physiomechanical properties of novel electrospun scaffolds to determine their suitability for hernia repair. Based on previous experimentation, scaffolds possessing ≥ 20 N suture retention strength, ≥ 20 N tear resistance, and ≥ 50 N/cm tensile strength are appropriate for hernia repair.

METHODS

Six novel electrospun scaffolds were fabricated by varying combinations of polymer concentration (10-12 %) and flow rate (3.5-10 mL/h). Briefly, poly(ε-caprolactone) (PCL) was dissolved in a solvent mixture and electrospun onto a planar metal collector, yielding sheets with randomly oriented fibers. Physiomechanical properties were evaluated through scanning electron microscopy, laser micrometry, and mechanical testing.

RESULTS

Scanning electron micrographs demonstrated fiber diameters ranging from 1.0 ± 0.1 μm (10 % PCL, 3.5 mL/h) to 1.5 ± 0.2 μm (12 % PCL, 4 mL/h). Laser micrometry demonstrated thicknesses ranging from 0.72 ± 0.07 mm (12 % PCL, 10 mL/h) to 0.91 ± 0.05 mm (10 % PCL, 3.5 mL/h). Mechanical testing identified two scaffolds possessing suture retention strengths ≥ 20 N (12 % PCL, 10 mL/h and 12 % PCL, 6 mL/h), and no scaffolds possessing tear resistance values ≥ 20 N (range, 4.7 ± 0.9 N to 10.6 ± 1.8 N). Tensile strengths ranged from 35.27 ± 2.08 N/cm (10 % PCL, 3.5 mL/h) to 81.76 ± 15.85 N/cm (12 % PCL, 4 mL/h), with three scaffolds possessing strengths ≥ 50 N/cm (12 % PCL, 10 mL/h; 12 % PCL, 6 mL/h; 12 % PCL, 4 mL/h).

CONCLUSIONS

Two electrospun scaffolds (12 % PCL, 10 mL/h and 12 % PCL, 6 mL/h) possessed suture retention and tensile strengths appropriate for hernia repair, justifying evaluation in a large animal model. Additional studies examining advanced methods of fabrication may further improve the unique properties of these scaffolds, propelling them into applications in a variety of clinical settings.

Abdominal wall reconstruction in patients with digestive tract fistulas

Abdominal wall reconstruction in the digestive tract fistula patient is a complex issue. The authors review the available data and present information regarding the timing of surgery, techniques of abdominal wall reconstruction, hernia repair, and discuss pitfalls associated with the various options. A simple and basic approach to this problem is described.

Implant-assisted meniscal repair in vivo using a chondrocyte-seeded flexible PLGA scaffold

A cell-based engineered construct can be used for healing of intractable meniscal lesions. Our aims were to assess the culture conditions (static versus dynamic oscillation) and the healing capacity of the chondrocyte-seeded flexible implants in a heterotopic mouse model. Swine articular chondrocytes were labeled with PKH 26 or DiI dye and seeded onto a flexible PLGA scaffold using dynamic oscillating conditions for 24 h. Half of cell-seeded scaffolds were cultured in the same dynamic conditions, while the remaining scaffolds were cultured statically. After 7 days, scaffolds were placed between swine meniscal discs and were implanted subcutaneously in nude mice for 6 weeks. Additional constructs for assessing in vivo cell tracking were implanted for 12 weeks. Live/dead assays demonstrated labeled chondrocytes attached throughout the scaffold in both culture conditions. DNA measurements showed no significant difference between the culture conditions. A continuous fibro-cartilaginous healing tissue was observed between meniscal discs in all 12 dynamically cultured constructs and 9 of 11 statically cultured ones. There was no evidence of meniscal healing using acellular scaffold as well as in meniscal constructs lacking an implant. Both PKH 26- and DiI-labeled cells were identified along the healing interface. We conclude the chondrocyte-seeded flexible PLGA implants induce healing of meniscal discs in nude mice. Culture conditions after seeding have no apparent effects on healing.

Effect of repetitive loading on the mechanical properties of synthetic hernia repair materials

BACKGROUND

Hernia repair materials undergo repeated loading while in the body, and the impact on mechanical properties is unknown. It was hypothesized that exposure to repetitive loading would lead to decreased tensile strength and increased strain, and that these differences would become more pronounced with greater loading and unloading sequences.

STUDY DESIGN

Polypropylene, expanded polytetrafluoroethylene, composite barrier, and partially absorbable meshes were evaluated. Twenty specimens (7.5 × 7.5 cm) were prepared from each material. Five specimens were subjected to ball burst testing to determine baseline biomechanical properties. Cycles of 10, 100, and 1,000 loading sequences were also performed (n = 5 each).

RESULTS

BardMesh (CR Bard/Davol), Dualmesh (WL Gore), and Prolene (Ethicon) exhibited significantly reduced tensile strength; BardMesh, Proceed (Ethicon), Prolene, ProLite (Atrium Medical), ProLite Ultra (Atrium Medical), and Ultrapro (Ethicon) exhibited significantly increased strain after exposure to 1,000 cycles compared with their baseline properties. BardMesh and Prolene demonstrated both reduced tensile strength and increased strain values after 1,000 cycles, suggesting that repetitive loading has the greatest effects on these materials. In addition, BardMesh and Prolene exhibited progressively worsening effects as the number of cycles was increased.

CONCLUSIONS

Deterioration of the tensile strength of the mesh or an increase in the ability of the mesh material to stretch (ie, increased strain values) could potentially lead to hernia recurrence or a poor functional result. However, the results of this study should not be interpreted to mean that hernia repair materials will fail in the body after only 10, 100, or 1,000 cycles. The conditions used in this study were more extreme than most physiologic scenarios and were intended as a pilot investigation into how the mechanical properties of hernia repair materials are affected by in vitro cyclic testing.

Mesh Repair for Midline Ventral Hernia Without Lateral Fixation of the Mesh

The Rives-Stoppa repair is the current standard of care for the open treatment of midline ventral hernia. Transfascial, lateral fixation of the mesh has always been considered an important part of this technique. I reviewed cases of patients with a primary or recurrent midline, ventral hernia who had an open repair using the Rives-Stoppa technique with the exception of mesh fixation. Heavy weight polypropylene mesh was sutured to the midline of the posterior rectus sheath with two to three interrupted stitches. Multiple metal clips were attached to the periphery of the mesh for later identification. Physical exams and CT scans were done on all patients postoperatively to assess the integrity of the repair. From November 2008 to January 2010 13 patients had an open repair using a modified Rives-Stoppa technique. All patients had an intact repair based on physical exam and a contiguous rectus abdominis muscle layer based on CT evaluation. Lateral fixation of heavy weight polypropylene mesh is not necessary when performing a retro-muscular repair using the Rives-Stoppa technique.

A painless complete abdominal wall palsy with groin and thigh paresthesiae related to traffic accident injury

INTRODUCTION

No case of complete unilateral abdominal wall palsy, occurring after a traffic accident, was found in the literature data. We report one case.

CASE REPORT

A 32-year-old woman was treated for a large abdominal hernia by mesh prosthesis nine years after a traffic accident injury. Surgery led to an iatrogenic lesion of the right lateral femoral cutaneous nerve (LFCN). During the electrodiagnostic examination for the LFCN lesion, abdominal wall palsy was diagnosed. Analysis of the patient's history and clinical, electrophysiological, and imaging data revealed that this abdominal wall palsy was related to a tear of the T10 to L2 anterior roots, plexus or nerves, a consequence of the violent deceleration during the car crash.

CONCLUSION

This report highlights the importance of clinical examination, electrodiagnosis and imaging in diagnosing abdominal wall palsy.

Comparison of Surgisis, AlloDerm, and Vicryl Woven Mesh grafts for abdominal wall defect repair in an animal model

BACKGROUND

Surgisis and AlloDerm, two biosynthetic materials, have been previously used with success in abdominal wall repairs in the setting of contaminated fields. Historically, Vicryl Woven Mesh, a synthetic material, has also been used in such settings as a temporary bridge for abdominal wall reconstruction. This study compares Surgisis and AlloDerm with Vicryl Woven Mesh with respect to tensile strength, collagen remodeling, and neovascularization using a rat hernia model.

METHODS

A prospective randomized trial of 54 Sprague-Dawley rats were assigned to the Surgisis, AlloDerm, or Vicryl Woven Mesh group with baseline, 30-day, and 60-day end points. A 1.5-cm x 5.0-cm defect was created in the right abdominis rectus muscle and repaired with an underlay bridge graft using the different treatment materials. Tensile strength was measured using an Instron tensiometer. Histologic specimens were evaluated for neovascularization, collagen deposition, and collagen organization at the 30- and 60-day time points.

RESULTS

Surgisis had significantly greater tensile strength compared to Vicryl Woven Mesh at the baseline time point (0.142 vs. 0.091 MPa, p < 0.05). There were no differences between groups tensile strength at 30 or 60 days postoperatively. The Vicryl Woven Mesh and AlloDerm groups showed increases in tensile strength at 30 days postoperatively versus baseline (p < 0.05). Vicryl Woven Mesh, Surgisis, and AlloDerm all showed increases in tensile strength at 60 days postoperatively compared to 30 days postoperatively and at baseline (p < 0.05). Surgisis and AlloDerm had significantly greater (p < 0.05) amounts of collagen deposition and organization at 30 and 60 days compared to Vicryl Woven Mesh. There was no significant difference between AlloDerm and Surgisis with respect to collagen deposition and organization. Surgisis and AlloDerm showed a significantly greater amount (p < 0.05) of neovascularization than Vicryl Woven Mesh at both time points. In addition, Surgisis had a significantly greater amount (p < 0.05) of neovascularization than AlloDerm at both 30 and 60 days.

CONCLUSION

Surgisis has increased baseline tensile strength compared to Vicryl Woven Mesh. Tensile strength in Vicryl Woven Mesh is equal to biosynthetic grafts after tissue incorporation. Biosynthetic grafts showed superior collagen deposition and organization. Surgisis mesh showed increased neovascularization over both AlloDerm and Vicryl Woven Mesh.

Tendon re-attachment to metal prostheses in an in vivo animal model using demineralised bone matrix

We used demineralised bone matrix (DBM) to augment re-attachment of tendon to a metal prosthesis in an in vivo ovine model of reconstruction of the extensor mechanism at the knee. We hypothesised that augmentation of the tendon-implant interface with DBM would enhance the functional and histological outcomes as compared with previously reported control reconstructions without DBM. Function was assessed at six and 12 weeks postoperatively, and histological examination was undertaken at 12 weeks. A significant increase of 23.5% was observed in functional weight-bearing at six weeks in the DBM-augmented group compared with non-augmented controls (p = 0.004). By 12 weeks augmentation with DBM resulted in regeneration of a more direct-type enthesis, with regions of fibrocartilage, mineralised fibrocartilage and bone. In the controls the interface was predominantly indirect, with the tendon attached to the bone graft-hydroxyapatite base plate by perforating collagen fibres.

Surgical progress in inguinal and ventral incisional hernia repair

The goals of this article are to describe the history of hernia repair and how innovations in surgical technique, prosthetics, and technology have shaped current practice.

Imaging findings of implanted absorbable mesh in patients with breast partial resection

PURPOSE

The author presents imaging findings of patients that underwent partial resection of the breast followed by absorbable mesh implantation.

MATERIALS AND METHODS

Ultrasonographic (n = 18) and mammographic (n = 11) images of patients that had undergone absorbable mesh implantation after breast partial resection were reviewed retrospectively. Sequential changes of the lesions were analyzed in follow-up ultrasonographic examinations, focusing on the change of the size and pattern of the lesion. The presence of a mass, asymmetry, focal asymmetry, architectural distortion, and calcification were evaluated by mammography. Pathologic findings of the implanted mesh in available cases were analyzed.

RESULTS

Ultrasonograms revealed a well-encapsulated anechoic lesion with (pattern 1, n = 11) or without (pattern 2, n = 5) internal isoechoic nodular portion, and a hyperechoic mass-like lesion without anechoic portion (pattern 3, n = 2). The mean length of the longest diameter decreased gradually as determined in follow-up examinations (3 months, 6.12 +/- 2.599cm; 6 months, 5.08 +/- 2.105cm; 12 months, 3.26 +/- 2.206cm). In mammograms, a mass (n = 4) was noted at the surgical site and focal asymmetry, overlapping with the postoperative change, was seen in the remaining seven cases. Pathologic findings of two cases revealed foreign body reaction.

CONCLUSION

Ultrasonography of the patients that underwent breast partial resection followed by absorbable mesh implantation showed a well-encapsulated cyst at the surgical site that gradually decreased in follow-up examinations. Adjunctive ultrasonography combined with mammography would be recommended in postoperative follow-up examinations.

Management of Laparotomy Wound Dehiscence

Many studies identify risk factors for dehiscence, but a paucity of data exist suggesting an optimal treatment strategy. This study examines repair of abdominal wound dehiscence, comparing closure and interposition of mesh. We conducted a retrospective review of 37 individuals who suffered a wound dehiscence after laparotomy. Outcomes of repairs with either primary closure or polyglactin mesh interposition were examined. Twenty-seven individuals underwent repair with primary closure. Twelve of these individuals suffered repeat wound dehiscence; 10 were treated with repeat fascial closure, 2 with polyglactin mesh interposition. Seven individuals initially underwent successful repair with polyglactin mesh interposition; all subsequently had their hernias repaired. Three patients had minor fascial separation managed nonoperatively. Primary closure is associated with a relatively high rate of recurrent wound dehiscence. Closure with polyglactin mesh interposition has a higher initial success rate, but necessitates additional surgeries for repair of the abdominal wall defect.

Abdominal Wall Reconstruction following Severe Loss of Domain: The R Adams Cowley Shock Trauma Center Algorithm

BACKGROUND

Large, complex, posttraumatic and recurrent abdominal hernias present a reconstructive challenge. Multiple techniques have been described to restore the integrity of the abdominal wall, although the indications and applications can be difficult to navigate. The authors propose an algorithm that facilitates the assessment and treatment of secondary large ventral defects.

METHODS

The algorithm described involves a systematic approach to abdominal wall reconstruction and was applied to 23 consecutive patients at the R Adams Cowley Shock Trauma Center. Data collected from the chart review included age, body mass index, mechanism of injury, placement of skin graft and use of resorbable mesh before definitive reconstruction, size of defect, number of tissue expanders placed, length of follow-up, and complications.

RESULTS

There were six female patients and 17 male patients, with an average age of 36 years. The average follow-up was 7 months. Seventeen patients had posttraumatic laparotomies, five patients had aggressive abdominal wall debridement following necrotizing fasciitis, and one patient developed a large abdominal wall hernia following complications from gastric bypass surgery. All patients underwent delayed abdominal wall reconstruction, with an average time to initial reconstruction of 19.5 months. Sixteen patients had no postoperative complications. Seven patients had complications, including one with an enterocutaneous fistula, one with a partial small bowel obstruction, two with seromas, one with a superficial wound infection, and two with recurrent abdominal wall laxity.

CONCLUSIONS

The reconstructive ladder for large, complex abdominal hernias is poorly defined. The proposed algorithm provides a systematic staged approach that incorporates available techniques used for delayed reconstruction of the abdominal wall.

The novel use of resorbable Vicryl mesh for in vivo tendon reconstruction to a metal prosthesis

We examined the mechanical properties of Vicryl (polyglactin 910) mesh in vitro and assessed its use in vivo as a novel biomaterial to attach tendon to a hydroxyapatite-coated metal implant, the interface of which was augmented with autogenous bone and marrow graft. This was compared with tendon re-attachment using a compressive clamp device in an identical animal model. Two- and four-ply sleeves of Vicryl mesh tested to failure under tension reached 5.13% and 28.35% of the normal ovine patellar tendon, respectively. Four-ply sleeves supported gait in an ovine model with 67.05% weight-bearing through the operated limb at 12 weeks, without evidence of mechanical failure.

Mesh fibres were visible at six weeks but had been completely resorbed by 12 weeks, with no evidence of chronic inflammation. The tendon-implant neoenthesis was predominantly an indirect type, with tendon attached to the bone-hydroxyapatite surface by perforating collagen fibres.

The use of prosthetics in abdominal wall reconstruction

Large ventral or incisional hernias are often difficult to manage. Most commonly patients are referred to reconstructive surgeons after multiple failed attempts of hernia repair. The use of prosthetic and bioprosthetic materials have aided greatly in the management of complex abdominal wall defects. A full understanding of the advantages and disadvantages of specific prosthetic materials available, and the associated complications of use, remains elusive, however. This article provides information concerning the applications of appropriate prosthetic material for temporary or permanent closure of difficult abdominal wall defects.