Prosthetic abdominal wall hernia repair in emergency surgery: from polypropylene to biological meshes

The increased angiogenic capacity and decreased inflammatory response when a mesh is used in combination with an omental flap. A prospective experimental study

BACKGROUND

The use of a surgical mesh for abdominal wall reconstruction is well established and has been used for long with minor complications, whereas the omental flap has been used for decades in reconstructive surgery.

AIM

To demonstrate the increased angiogenic capacity and the reduced inflammatory markers of a synthetic mesh when used in combination with an omental flap. Furthermore, we compare two independent meshes when used alone or in combination with the omental flap.

MATERIALS AND METHODS

Twenty-eight rats were included in the study. To determine the effect of using an omental flap under two different meshes, the animals were separated into four groups, i.e., group A (flap + mesh 1), group B (flap + mesh 1 + silicone), group C (flap + mesh 2), and group D (flap + mesh 2 + silicone). A silicone sheet was placed as a barrier between the mesh and the flap. All groups were sacrificed 8 weeks post-operatively.

RESULTS

The use of a silicone sheet barrier between any of the two synthetic meshes and the omental flap in an abdominal wall defect is accompanied by a markedly reduced angiogenesis in terms of a cluster of differentiation (CD)-34 (p < 0.001) and factor VIII (p = 0.0012) and by increased inflammatory response CD-68 (p = 0.0024) and visual scoring (p < 0.001).

CONCLUSIONS

Τhe increased angiogenic capacity and the reduced inflammatory markers of a synthetic surgical mesh when used in combination with an omental flap make it a useful option in the reconstruction of an abdominal wall defect on a large or contaminated wound.

PROPHYlactic Implantation of BIOlogic Mesh in peritonitis (PROPHYBIOM): a prospective multicentric randomized controlled trial

BACKGROUND

Patients undergoing emergency surgery for peritonitis are at increased risk of abdominal wall-related complications. In patients with peritonitis, the risk of incisional hernia (IH) is extremely elevated. The evaluation of quality of life of patients with incisional hernia showed lower mean scores on physical components of health-related quality of life and body image. Furthermore, the arise of a post-operative abdominal wall complication (i.e., wound dehiscence, evisceration and IH) greatly increases morbidity and mortality rates and prolongs the hospitalization.

METHODS

The present study aims to evaluate the efficacy of the use of a swine dermal collagen prosthesis implanted preperitoneally as a prophylactic procedure in urgency/emergency setting against abdominal wall complications in patients operated with contaminated/infected field in peritonitis. The sample size was defined in 90 patients divided in two arms (prosthesis positioning versus normal wall abdominal closure). The follow-up will be performed at 3, 6, and 12 months after surgery. The percentage of incisional hernias, wound infections, and adverse events will be investigated by physical examination and ultrasound.

DISCUSSION

The objective is to evaluate the possibility to reduce the incisional hernia rate in patients undergoing urgent/emergent laparotomy in contaminated/infected field with peritonitis by using swine dermal collagen prosthesis preperitoneal positioning as a prophylactic procedure.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04681326. Registered (retrospectively after first patient recruited) on 23 December 2020.

The Effect of Adipose-Derived Stromal Vascular Fraction Cells to Abdominal Wall Fascia Defects in Rats: An Experimental Study

OBJECTIVE

Various synthetic and biological meshes have been developed to reduce recurrence and complications in ventral incisional hernia repairs. Adipose tissue is a rich reserve for mesenchymal stromal cells. In the present study we aimed to examine the effects of adipose-derived mesenchymal stromal cells (AD-MSCs) on abdominal incisional hernia repairs in rats.

MATERIALS AND METHODS

The study involved 32 male Wistar-Albino rats, weighing 200-250 g, which were divided into three groups. In Group 1 (control group) only an incisional hernia model was created. In Group 2, the incisional hernia model was created and 1 ml stromal vascular fraction (SVF), obtained from inguinal lipectomy material and containing mesenchymal stromal cells, was injected into the edges of the defect in the same session. In Group 3, only the incisional hernia model was created in the first stage and after 14 days, 1 ml of SVF was injected into the edges of the defect. Skin incisions of rats in Group 1 and 2 were opened on postoperative day 28 while in group 3 were opened on day 42. Peritoneal formation in abdominal wall defect was evaluated macroscopically and histopathologically.

RESULTS

Peritoneal formation was significantly superior in Groups 2 and 3 than in Group 1 (p: 0.031). In histopathological evaluation, the structural distortion and polymorphonuclear leukocyte (PMNL) levels were significantly higher in Group 1 than in Group 3 (p: 0.048 and p: 0.046, respectively). Granulation, capillary density, fibrosis and collagen organization were higher in Group 2 and 3, however this difference was not statistically significant (p > 0.05).

CONCLUSIONS

Adipose-derived stromal vascular fraction cells obtained from inguinal lipectomy material in rats positively affect the repair of abdominal incisional hernias by increasing peritoneal formation, and reducing structural distortion and PMNL infiltration.

Injectable in situ cross-linking chitosan-hyaluronic acid based hydrogels for abdominal tissue regeneration

Abdominal wall defect caused by open abdomen (OA) or abdominal trauma is a serious issue since it induces several clinical problems. Although a variety of prosthetic materials are commonly employed, complications occur including host soft tissue response, fistula formation and chronic patient discomfort. Recently, abundant natural polymers have been used for injectable hydrogel synthesis in tissue regeneration. In this study, we produced the chitosan - hyaluronic acid (CS/HA) hydrogel and investigated its effects on abdominal tissue regeneration. The physical and biological properties of the hydrogel were demonstrated to be suitable for application in abdominal wounds. In a rat model simulating open abdomen and large abdominal wall defect, rapid cellular response, sufficient ECM deposition and marked neovascularization were found after the application of the hydrogel, compared to the control group and fibrin gel group. Further, the possible mechanism of these findings was studied. Cytokines involved in angiogenesis and cellular response were increased and the skew toward M2 macrophages credited with the functions of anti-inflammation and tissue repair was showed in CS/HA hydrogel group. These findings suggested that CS/HA hydrogel could prevent the complications and was promising for abdominal tissue regeneration.

Use of a pedicled omental flap to reduce inflammation and vascularize an abdominal wall patch

BACKGROUND

Although a variety of synthetic materials have been used to reconstruct tissue defects, these materials are associated with complications such as seromas, fistulas, chronic patient discomfort, and surgical site infection. While alternative, degradable materials that facilitate tissue growth have been examined. These materials can still trigger a foreign body inflammatory response that can lead to complications and discomfort.

MATERIALS AND METHODS

In this report, our objective was to determine the effect of placing a pedicled omental flap under a biodegradable, microfibrous polyurethane scaffold serving as a full-wall thickness replacement of the rat abdominal wall. It was hypothesized that the presence of the omental tissue would stimulate greater vascularization of the scaffold and act to reduce markers of elevated inflammation in the patch vicinity. For control purposes, a polydimethylsiloxane sheet was placed as a barrier between the omental tissue and the overlying microfibrous scaffold. Both groups were sacrificed 8 wk after the implantation, and immunohistological and reverse transcription polymerase chain reaction (RT-PCR) assessments were performed.

RESULTS

The data showed omental tissue placement to be associated with increased vascularization, a greater local M2/M1 macrophage phenotype response, and mRNA levels reduced for inflammatory markers but increased for angiogenic and antiinflammatory factors.

CONCLUSIONS

From a clinical perspective, the familiarity with utilizing omental flaps for an improved healing response and infection resistance should naturally be considered as new tissue engineering approaches that are translated to tissue beds where omental flap application is practical. This report provides data in support of this concept in a small animal model.

Pattern of abdominal wall herniae in females: a retrospective analysis

BACKGROUND

Gender differences are expected to influence the pattern and outcome of management of abdominal wall hernias. Some of these are left to speculations with few published articles on hernias in females.

OBJECTIVES

To describe the clinical pattern of abdominal wall hernias in females.

METHOD

A 5 year retrospective review.

RESULT

There were 181 female patients with 184 hernias representing 27.9% of the total number of hernia patients operated. Mean age was 41.66±24.46 years with a bimodal peak in the 1(st) and 7(th) decades. Inguinal hernia accounted for majority (50.5%) but incisional hernia predominated in the 30-49 age group, while only inguinal and umbilical hernias were seen in the first two decades (p=0.04). There was no side predilection in the cases of inguinal hernia. There were 12 (6.6%) emergency presentations, most of which occurred in the 6th decade and above and none below 30 years (p=0.02). Umbilical (4 cases) and femoral hernias (3cases) accounted for most of these cases. Incisional hernia was the commonest cause of recurrent hernias.

CONCLUSION

Inguinal hernia is the commonest hernia type in females followed by incisional hernias which also accounteds for most recurrent cases. Age appears to be a risk factor for developing complications.

Hybrid technique for postoperative ventral hernias - own experience

INTRODUCTION

There are many techniques which may be involved in abdominal hernia repair, from classical to tension-free. Treatment of complicated hernias has undergone evolution. Many surgeons consider the laparoscopic method as a method of choice for incisional hernia repair. Sometimes miniinvasive repair of complicated hernia is not so easy to perform. We are convinced that selected patients may benefit from combined open and laparoscopic techniques.

AIM

To present the operating technique and early results of treatment of 15 patients operated on using the 3 hybrid technique.

MATERIAL AND METHODS

Fifteen patients suffering from recurrent incisional hernias underwent the hybrid technique for their repair between June 2012 and April 2015. The hybrid technique was performed using synthetic meshes in 14 cases and a biological implant in 1 case.

RESULTS

The early postoperative period was uncomplicated in all cases. Within a maximum follow-up period of 32 months, two deep wound infections were observed.

CONCLUSIONS

The hybrid technique may be used in patients with recurrent incisional hernias.

The open abdomen, indications, management and definitive closure

The indications for Open Abdomen (OA) are generally all those situations in which is ongoing the development an intra-abdominal hypertension condition (IAH), in order to prevent the development of abdominal compartmental syndrome (ACS). In fact all those involved in care of a critically ill patient should in the first instance think how to prevent IAH and ACS. In case of ACS goal directed therapy to achieve early opening and early closure is the key: paradigm of closure shifts to combination of therapies including negative pressure wound therapy and dynamic closure, in order to reduce complications and avoid incisional hernia. There have been huge studies and progress in survival of critically ill trauma and septic surgical patients: this in part has been through the great work of pioneers, scientific societies and their guidelines; however future studies and continued innovation are needed to better understand optimal treatment strategies and to define more clearly the indications, because OA by itself is still a morbid procedure.

Biologic mesh versus synthetic mesh in open inguinal hernia repair: system review and meta-analysis

BACKGROUND

Biologic meshes are mostly used for abdominal wall reinforcement in infected fields, but no consensus has been reached on its use for inguinal hernia repairing. The purpose of this study was to compare biologic mesh with synthetic mesh in open inguinal herniorrhaphy.

METHODS

A systematic literature review and meta-analysis was undertaken to identify studies comparing the outcomes of biologic mesh and synthetic mesh in open inguinal hernia repair. Published studies were identified by the databases PubMed, EMBASE and the Cochrane Library.

RESULTS

A total of 382 patients in five randomized controlled trials were reviewed (179 patients in biologic mesh group; 203 patients in synthetic mesh group). The two groups did not significantly differ in chronic groin pain (P = 0.06) or recurrence (P = 0.38). The incidence of seroma trended higher in biologic mesh group (P = 0.03). Operating time was significantly longer with biologic mesh (P = 0.03). There was no significant difference in hematomas (P = 0.23) between the two groups.

CONCLUSIONS

From the data of this study, biologic mesh had no superiority to synthetic mesh in open inguinal hernia repair with similar recurrence rates and incidence of chronic groin pain, but higher rate of seroma and longer operating time. However, this mesh still needs to be assessed in a large, multicentre, well-designed randomized controlled trial.

Laparoscopic ventral/incisional hernia repair: updated Consensus Development Conference based guidelines [corrected]

BACKGROUND

The Executive board of the Italian Society for Endoscopic Surgery (SICE) promoted an update of the first evidence-based Italian Consensus Conference Guidelines 2010 because a large amount of literature has been published in the last 4 years about the topics examined and new relevant issues.

METHODS

The scientific committee selected the topics to be addressed: indications to surgical treatment including special conditions (obesity, cirrhosis, diastasis recti abdominis, acute presentation); safety and outcome of intraperitoneal meshes (synthetic and biologic); fixing devices (absorbable/non-absorbable); abdominal border and parastomal hernia; intraoperative and perioperative complications; and recurrent ventral/incisional hernia. All the recommendations are the result of a careful and complete literature review examined with autonomous judgment by the entire panel. The process was supervised by experts in methodology and epidemiology from the most qualified Italian institution. Two external reviewers were designed by the EAES and EHS to guarantee the most objective, transparent, and reliable work. The Oxford hierarchy (OCEBM Levels of Evidence Working Group*. "The Oxford 2011 Levels of Evidence") was used by the panel to grade clinical outcomes according to levels of evidence. The recommendations were based on the grading system suggested by the GRADE working group.

RESULTS AND CONCLUSIONS

The availability of recent level 1 evidence (a meta-analysis of 10 RCTs) allowed to recommend that not only laparoscopic repair is an acceptable alternative to the open repair, but also it is advantageous in terms of shorter hospital stay and wound infection rate. This conclusion appears to be extremely relevant in a clinical setting. Indications about specific conditions could also be issued: laparoscopy is recommended for the treatment of recurrent ventral hernias and obese patients, while it is a potential option for compensated cirrhotic and childbearing-age female patients. Many relevant and controversial topics were thoroughly examined by this consensus conference for the first time. Among them are the issue of safety of the intraperitoneal mesh placement, traditionally considered a major drawback of the laparoscopic technique, the role for the biologic meshes, and various aspects of the laparoscopic approach for particular locations of the defect such as the abdominal border or parastomal hernias.

A primer on wound healing in colorectal surgery in the age of bioprosthetic materials

Wound healing is a complex, dynamic process that is vital for closure of cutaneous injuries, restoration of abdominal wall integrity after laparotomy closure, and to prevent anastomotic dehiscence after bowel surgery. Derangements in healing have been described in multiple processes including diabetes mellitus, corticosteroid use, irradiation for malignancy, and inflammatory bowel disease. A thorough understanding of the process of healing is necessary for clinical decision making and knowledge of the current state of the science may lead future researchers in developing methods to enable our ability to modulate healing, ultimately improving outcomes. An exciting example of this ability is the use of bioprosthetic materials used for abdominal wall surgery (hernia repair/reconstruction). These bioprosthetic meshes are able to regenerate and remodel from an allograft or xenograft collagen matrix into site-specific tissue; ultimately being degraded and minimizing the risk of long-term complications seen with synthetic materials. The purpose of this article is to review healing as it relates to cutaneous and intestinal trauma and surgery, factors that impact wound healing, and wound healing as it pertains to bioprosthetic materials.

The Italian Register of Biological Prostheses

BACKGROUND

A wide variety of meshes are available for surgical treatment of abdominal wall defects. These meshes are constructed with different materials with different biological properties.

METHODS

A prospective database was instituted (January 2009-December 2010) to register biological prostheses (BPs) implanted in Italy.

RESULTS

A total of 193 cases were registered. The mean age of the patients was 53.1 years (SD ±7.4). The ratio of males to females was 1.3 to 1. The mean body mass index was 28.2 (SD ±4.1). The breakdown of American Society of Anesthesiologists (ASA) scores was as follows: ASA I, 35.7%; ASA II, 27.5%; ASA III, 31.6%, and ASA IV, 5.2%. For ventral-incisional hernias, the mean duration of surgery was 101.1 min (SD ±25.3), while for inguinal-femoral hernias it was 49.2 min (SD ±19.1). The rate of urgent procedures was 36.7%. The surgical field was clean in 57.4% of cases, clean-contaminated in 21.3%, contaminated in 12.3% and dirty in 9%. Techniques used for inguinal-femoral hernias were as follows: Lichtenstein in 66.7%, plug and mesh in 3.8%, transabdominal-preperitoneal in 25.7% and intraperitoneal onlay mesh in 3.8%. The following prostheses were used: swine intestinal submucosa in 54.9%, porcine dermal collagen in 39.9% and bovine pericardium in 5.2%. In 45.1% of cases the prostheses were cross-linked. Techniques used for ventral-incisional hernias were as follows: onlay in 3.6%, inlay in 5.5%, sublay in 62.7% and underlay via laparoscopy in 28.2%. The mean overlap was 4.1 cm (SD ±1.2). No intestinal anastomosis was necessary in 65.3% of cases; however, small/large bowel resection and anastomoses were necessary in 22.3 and 12.4% of cases, respectively. Intraoperative blood transfusion was necessary in 10.4% of procedures. The skin was completely closed in 84% of procedures. At the 1-month follow-up, there were no complications in 54.4% of cases. Among the cases with complications, 10 patients (5.8%) experienced recurrence, and the postoperative readmission rate was 12.9%. The average visual analog scale (VAS) score for pain was 2.9 (SD ±1.2) at rest. At the 1-year follow-up, there were no complications in 96.4% of cases. Two patients experienced recurrence, and the postoperative readmission rate was 3.6%. The average VAS score for pain was 1.8 (SD ±0.8) at rest.

CONCLUSIONS

This register shows that BPs are highly versatile and can be used in either open or laparoscopic surgery in all kinds of patients and in contaminated surgical fields. However, due to the very good outcomes of synthetic meshes and the high costs of BPs, the latter should only be used in selected cases.

The persistent challenge of parastomal herniation: a review of the literature and future developments

AIM

The aim of this review article was to outline current evidence relating to the treatment and prevention of parastomal herniation with a view to guide surgeons dealing with patients potentially affected by this complication.

METHOD

Medline and PubMed databases were searched using the keywords 'parastomal hernia/herniation', 'stoma hernia/herniation' and 'stoma complications'. Evidence was obtained from randomized and non-randomized studies. Case reports and articles not written in English were excluded. Qualitative assessment of all included studies was performed using the Oxford Centre for Evidence-Based Medicine 2011 levels of evidence.

RESULTS

The search revealed a total of 228 publications of which 115 fulfilled the selection criteria. Stoma formation through the rectus muscle is complicated by parastomal herniation in up to 50% of cases. There is no conclusive evidence that alternative techniques (e.g. extraperitoneal, lateral rectus abdominis positioned stoma) are superior. Open and laparoscopic parastomal hernia repair have similar recurrence rates up to 50%. The 'Sugarbaker' technique appears to be superior to the 'keyhole' technique when a laparoscopic approach is used. Prophylactic mesh reinforcement of the stoma trephine appears to reduce the herniation rate to approximately 15% and is accompanied by a decrease in symptomatic hernias requiring repair without any difference in stoma-related morbidity.

CONCLUSION

Large prospective controlled trials are required to compare surgical techniques of stoma formation in reducing the incidence of parastomal herniation. Despite limited evidence, routine prophylactic mesh reinforcement of the stoma trephine should be offered to all patients undergoing permanent stoma formation.

Abdominal wall defect repair with biological prosthesis in transplanted patients: single center retrospective analysis and review of the literature

The risk of fascial dehiscence, wound infection and incisional hernias in organ recipients is higher. Retrospective analysis of our departments database, checking the last 12 years (2000-2012), and of the literature (1966-2012) were conducted. In our database we found seven patients: five liver (71.4 %), one kidney (14.3 %), one multivisceral (14.3 %); five males (71.4 %), two females (28.6 %). Five (71.4 %) were operated in urgency setting and two in ordinary setting (28.6 %). The mean/median number of laparotomies before the incisional hernia is of 2.1/1 (range 1-5). In five patients swine intestinal submucosa (71.4 %) have been used and in two porcine dermal collagen (28.6 %). The mean/median age was 48.3/52 years (range 18-61). The mean/median body mass index was 26.7/27 (range 19-34). The mean/median for follow-up after intervention was 40.1/33 months (range 50-21). Recurrence rate was 14.3 %. Complication rate was 28.6 %. Adding the present report, the literature reports 70 cases. 20 % of prosthesis have been implanted inlay, 25.7 % underlay, in 5.7 % intraperitoneal and in 48.6 % were not specified. The mean age ranges from 0.7 to 48.3 years. Kidney, liver, pancreas, bowel and multivisceral transplant are reported. Porcine dermal collagen has been implanted in 24.3 %, human dermal collagen in 51.4 % and swine intestinal submucosa in 24.3 %. The immunosuppression regimens comprehend variable associations of tacrolimus, steroids, mycophenolate mofetil, sirolimus, thymoglobulin, azathioprine/basiliximab and daclizumab. The mean follow-up is 16.2 months. The mean complication rate is 9.4 %. Biological prosthesis seems to be useful and safe in abdominal wall repair surgery in transplanted patients.

Thoracic wall reconstruction with Collamend® in trauma: report of a case and review of the literature

INTRODUCTION

Despite progress in reconstructive techniques, rebuilding portions of the thorax remains challenging, in particular when large resections, contamination or infection are involved. No other cases of thoracic reconstruction in trauma patients with biological prosthesis have been described since now.

METHODS

We report a case of thoracic reconstruction in highly infected field in a trauma patient. We also performed a literature review about the topic.

CONCLUSION

Collamend® demonstrated its usefulness in thoracic wall reconstruction even in trauma patients and infected fields.

Biologic grafts for ventral hernia repair: a systematic review

BACKGROUND

Biologic grafts hold promise of a durable repair for ventral hernias with the potential for fewer complications than synthetic mesh. This systematic review was performed to evaluate the effectiveness and safety of biologic grafts for ventral hernia repair.

METHODS

MEDLINE, Embase, and Cochrane Central Register of Controlled Trials were searched for studies on biologic grafts for the repair of ventral hernias. Outcomes are presented as weighted pooled proportions.

RESULTS

Twenty-five retrospective studies were included. Recurrence depended on wound class, with an overall rate of 13.8% (95% confidence interval [CI], 7.6-21.3). The recurrence rate in contaminated/dirty repairs was 23.1% (95% CI, 11.3-37.6). Abdominal wall laxity occurred in 10.5% (95% CI, 3.7-20.3) of patients. The surgical morbidity rate was 46.3% (95% CI, 33.3-59.6). Infection occurred in 15.9% (95% CI, 9.8-23.2) of patients but only led to graft removal in 4.9% of cases.

CONCLUSIONS

No randomized trials are available to properly evaluate biologic grafts for ventral hernia repair. The current evidence suggests that biologic grafts perform similarly to other surgical options. Biologic grafts are associated with a high salvage rate when faced with infection.

Laparoscopic approach to acute abdomen from the Consensus Development Conference of the Società Italiana di Chirurgia Endoscopica e nuove tecnologie (SICE), Associazione Chirurghi Ospedalieri Italiani (ACOI), Società Italiana di Chirurgia (SIC), Società Italiana di Chirurgia d'Urgenza e del Trauma (SICUT), Società Italiana di Chirurgia nell'Ospedalità Privata (SICOP), and the European Association for Endoscopic Surgery (EAES)

BACKGROUND

In January 2010, the SICE (Italian Society of Endoscopic Surgery), under the auspices of the EAES, decided to revisit the clinical recommendations for the role of laparoscopy in abdominal emergencies in adults, with the primary intent being to update the 2006 EAES indications and supplement the existing guidelines on specific diseases.

METHODS

Other Italian surgical societies were invited into the Consensus to form a panel of 12 expert surgeons. In order to get a multidisciplinary panel, other stakeholders involved in abdominal emergencies were invited along with a patient's association. In November 2010, the panel met in Rome to discuss each chapter according to the Delphi method, producing key statements with a grade of recommendations followed by commentary to explain the rationale and the level of evidence behind the statements. Thereafter, the statements were presented to the Annual Congress of the EAES in June 2011.

RESULTS

A thorough literature review was necessary to assess whether the recommendations issued in 2006 are still current. In many cases new studies allowed us to better clarify some issues (such as for diverticulitis, small bowel obstruction, pancreatitis, hernias, trauma), to confirm the key role of laparoscopy (such as for cholecystitis, gynecological disorders, nonspecific abdominal pain, appendicitis), but occasionally previous strong recommendations have to be challenged after review of recent research (such as for perforated peptic ulcer).

CONCLUSIONS

Every surgeon has to develop his or her own approach, taking into account the clinical situation, her/his proficiency (and the experience of the team) with the various techniques, and the specific organizational setting in which she/he is working. This guideline has been developed bearing in mind that every surgeon could use the data reported to support her/his judgment.

Use of mesh during ventral hernia repair in clean-contaminated and contaminated cases: outcomes of 33,832 cases

OBJECTIVE

To analyze and compare postoperative occurrences following ventral hernia repairs (VHRs) using mesh in clean-contaminated and contaminated wounds.

BACKGROUND

Ventral hernia repairs using mesh is one of the most common surgical procedures performed. However, guidelines and outcomes of repairs in clean-contaminated or grossly contaminated ventral hernias have not been established.

METHODS

Patients who underwent VHR with mesh between the dates January 1, 2005 and April 4, 2010 at all hospitals in the United States participating in the National Surgical Quality Improvement Program (NSQIP) were reviewed. Data from 33,832 patients were analyzed by field contamination level and then compared with data from patients who underwent VHR without mesh. Data were analyzed using the odds ratio test with a 95% confidence interval.

RESULTS

The odds of having one or more postoperative occurrences were significantly greater in clean-contaminated and contaminated cases using mesh when compared with clean cases, with odds ratios of 3.56 (3.25-3.89) and 5.05 (1.78-12.41), respectively. There was a significantly increased risk of superficial surgical site infections (SSI) (2.53), deep SSI (3.09) and organ/space SSI (6.16), wound disruption (4.41), pneumonia (4.43), and sepsis (4.90) for clean-contaminated cases. Both clean-contaminated and contaminated cases had an increased risk of septic shock (5.82 and 26.74, respectively), and need for ventilator for more than 48 hours (5.59 and 26.76, respectively). In addition, there was a significantly increased odds ratio of complications in patients who underwent VHR with mesh (3.56) to nonmesh (2.52) in clean-contaminated cases.

CONCLUSION

There is a significant increase in risk of postoperative occurrences following VHRs using mesh in clean-contaminated and contaminated cases relative to clean cases. We recommend avoiding the use of mesh in any level of contamination.

Necrotizing fasciitis: literature review of contemporary strategies for diagnosing and management with three case reports: torso, abdominal wall, upper and lower limbs

Necrotizing fasciitis (NF) is an uncommon soft tissue infection, usually caused by toxin-producing virulent bacteria. It is characterized by widespread fascial necrosis primarily caused by Streptococcus hemolyticus. Shortly after the onset of the disease, patients become colonized with their own aerobic and anaerobic microflora from the gastrointestinal and/or urogenital tracts. Early diagnosis with aggressive multidisciplinary treatment is mandatory. We describe three clinical cases with NF. The first is a 69 years old man with diabetes mellitus type II, who presented with NF on the posterior chest wall, shoulder and arm. He was admitted to the intensive care unit (ICU) with a clinical picture of severe sepsis. Outpatient treatment and early surgical debridement of the affected zones (inside 3 hours after admittance) and critical care therapy were performed. The second case is of a 63 years old paraplegic man with diabetes mellitus type I. Pressure sores and perineal abscesses progressed to Fournier's gangrene of the perineum and scrotum. He had NF of the anterior abdominal wall and the right thigh. Outpatient treatment and early surgical debridement of the affected zones (inside 6 hour after admittance) and critical care therapy were performed. The third patient was a 56 year old man who had NF of the anterior abdominal wall, flank and retroperitoneal space. He had an operation of the direct inguinal hernia, which was complicated with a bowel perforation and secondary peritonitis. After establishing the diagnosis of NF of the abdominal wall and retroperitoneal space (RS), he was transferred to the ICU. There he first received intensive care therapy, after which emergency surgical debridement of the abdominal wall, left colectomy, and extensive debridement of the RS were done (72 hours after operation of inquinal hernia). On average, 4 serial debridements were performed in each patient. The median of serial debridement in all three cases was four times. Other intensive care therapy with a combination of antibiotics and adjuvant hyperbaric oxygen therapy (HBOT) was applied during the treatment. After stabilization of soft tissue wounds and the formation of fresh granulation tissue, soft tissue defect were reconstructed using simple to complex reconstructive methods.

Morphological and mechanical characteristics of the reconstructed rat abdominal wall following use of a wet electrospun biodegradable polyurethane elastomer scaffold

Although a variety of materials are currently used for abdominal wall repair, general complications encountered include herniation, infection, and mechanical mismatch with native tissue. An approach wherein a degradable synthetic material is ultimately replaced by tissue mechanically approximating the native state could obviate these complications. We report here on the generation of biodegradable scaffolds for abdominal wall replacement using a wet electrospinning technique in which fibers of a biodegradable elastomer, poly(ester urethane)urea (PEUU), were concurrently deposited with electrosprayed serum-based culture medium. Wet electrospun PEUU (wet ePEUU) was found to exhibit markedly different mechanical behavior and to possess an altered microstructure relative to dry processed ePEUU. In a rat model for abdominal wall replacement, wet ePEUU scaffolds (1x2.5 cm) provided a healing result that developed toward approximating physiologic mechanical behavior at 8 weeks. An extensive cellular infiltrate possessing contractile smooth muscle markers was observed together with extensive extracellular matrix (collagens, elastin) elaboration. Control implants of dry ePEUU and expanded polytetrafluoroethylene did not experience substantial cellular infiltration and did not take on the native mechanical anisotropy of the rat abdominal wall. These results illustrate the markedly different in vivo behavior observed with this newly reported wet electrospinning process, offering a potentially useful refinement of an increasingly common biomaterial processing technique.

Rejection of Permacol® mesh used in abdominal wall repair: A case report

Permacol^® mesh has shown promise when used in abdominal wall repair, especially in the presence of a contaminated surgical field. This biomaterial, derived from porcine dermis collagen, has proposed advantages over synthetic materials due to increased biocompatibility and reduced foreign body reaction within human tissues. However, we present a case report describing a patient who displayed rejection to a Permacol^® mesh when used in the repair of abdominal wound dehiscence following an emergency laparotomy. Review of the English language literature using PubMed and Medline, showed only two previously published cases of explantation of Permacol^® due to sepsis or wound breakdown. The authors believe this is the first case of severe foreign body reaction leading to rejection of Permacol^®. Both animal and human studies show conflicting evidence of biocompatibility. There are several reports of successful use of Permacol^® to repair complex incisional herniae or abdominal walls in the presence of significant contamination. It appears from the literature that Permacol^® is a promising material, but as we have demonstrated, it has the potential to evoke a foreign body reaction and rejection in certain subjects.

A review on delayed presentation of diaphragmatic rupture

Diaphragmatic rupture is a life-threatening condition. Diaphragmatic injuries are quite uncommon and often result from either blunt or penetrating trauma. Diaphragmatic ruptures are usually associated with abdominal trauma however, it can occur in isolation. Acute traumatic rupture of the diaphragm may go unnoticed and there is often a delay between the injury and the diagnosis. A comprehensive literature search was performed using the terms "delayed presentation of post traumatic diaphragmatic rupture" and "delayed diaphragmatic rupture". The diagnostic and management challenges encountered are discussed, together with strategies for dealing with them. We have focussed on mechanism of injury, duration, presentation and site of injury, visceral herniation, investigations and different approaches for repair. We intend to stress on the importance of delay in presentation of diaphragmatic rupture and to provide a review on the available investigations and treatment methods. The enclosed case report also emphasizes on the delayed presentation, diagnostic challenges and the advantages of laparoscopic repair of delayed diaphragmatic rupture.