Adverse effects of porcine small intestine submucosa (SIS) implants in experimental ventral hernia repair

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.

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.

Characterisation and comparison of the host response of 6 tissue-based surgical implants in a subcutaneous in vivo rat model

BACKGROUND

Hernia repair often involves fascial augmentation using biologic prostheses. Small processing changes during preparation modulate host tissue response, which influence material efficacy and longevity. In this pilot study, a rat model was used to determine the specific influence of tissue origin, decellularisation treatment and 1,6-hexamethylene diisocyanate (HMDI) cross-linking.

METHODS

Materials (1 cm2) were implanted subcutaneously into 6-week-old Wistar rats (4 materials per animal, n=6/material per time point) for 2, 5, 7, 14 and 28 days. Histologic processing was carried out after resin infiltration, observing classical histopathology and pathologic indexing. Materials comprised 6 tissue-based grafts covering both experimental and commercial porcine decellularised dermal and small intestinal submucosal materials.

RESULTS

Subcutaneous delivery of biologics demonstrated material-specific inflammatory/host responses. Controlled variations of the PermacolTM manufacturing process showed sodium dodecyl sulfate (SDS) was the most proinflammatory decellularisation reagent, and HMDI cross-linking had no effect on host response. All materials remained recoverable after 28 days, although SurgisisTM had partially resorbed.

CONCLUSION

Differences in host responses exist between biologic implants for hernia repair in this rat model. It is postulated that these modifications are induced during processing and may have an effect on the clinical outcome of hernia repair.

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 use of porcine small intestine submucosa implants might be associated with a high recurrence rate following laparoscopic herniorrhaphy

BACKGROUND/PURPOSE

The efficacy of porcine small intestine submucosa (SIS) implants in hernia repair has rarely been reported and remained elusive. We herein report our experience to further elucidate the efficacy of SIS mesh in herniorrhaphy.

METHODS

Between June 2008 and October 2009, a total of 82 patients with 125 inguinal hernias undergoing endoscopic total extraperitoneal (TEP) herniorrhaphy were included. Seventy patients (with 108 hernias) had traditional polypropylene and 12 patients (with 17 hernias) had SIS mesh repair. Postoperative complications and recurrence rates were compared between the two meshes.

RESULTS

The demographics between two groups were similar. All operations were performed smoothly with laparoscopy, and the postoperative courses were uneventful. After a median follow-up of 18 months, five (7%) in the polypropylene group and three (25%) in the SIS group had chronic pain (p = 0.09). Five of 17 (29.4%) hernia repairs in the SIS group had an ipsilateral recurrence, compared to no recurrence in the polypropylene group. In the five cases, the second laparoscopy revealed the SIS mesh had been totally degraded and there was no obvious fibrotic tissue in the previous mesh sites.

CONCLUSION

Our data suggest that the use of SIS mesh in endoscopic TEP herniorrhaphy might be associated with a high recurrence rate. The second look laparoscopy in these recurrent cases revealed slow and inadequate integration of host tissue. More evidence is still required to further evaluate the efficacy of SIS mesh in endoscopic TEP herniorrhaphy.

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.

Italian Biological Prosthesis Work-Group (IBPWG): proposal for a decisional model in using biological prosthesis

Introduction

Indications for repair of abdominal hernia are well established and widely diffused. Controversies still exist about the indication in using the different prosthetic materials and principally about the biological ones.

Material and methods

In February 2012, the Italian Biological Prosthesis Work-Group (IBPWG), counting a background of 264 biologic implants, met in Bergamo (Italy) for 1-day meeting with the aim to elaborate a decisional model on biological prosthesis use in abdominal surgery.

Results

A diagram to simplify the decisional process in using biologics has been elaborated.

Conclusion

The present score represents a first attempt to combine scientific knowledge and clinical expertise in order to offer precise indications about the kind of biological mesh to use.

Biological meshes: a review of their use in abdominal wall hernia repairs

PURPOSE

Biological meshes are mostly used in infected fields within complex abdominal wall hernia repairs. There is no consensus, however, on the most appropriate material to be used in a given situation.

METHODS

A literature review of published articles reporting the utilization of biological meshes in ventral/incisional hernia repair was conducted. Data were analyzed to compare the recurrence rates obtained with biological meshes.

MAIN FINDINGS

Only a few prospective comparative studies were identified. Most publications relate to AlloDerm®, Permacol™ and Surgisis™ with data from other meshes insufficient to draw conclusions. AlloDerm has a 0-100% recurrence rate among studies. It compares poorly with Surgisis and results in an unfavorable outcome when used as a 'bridge prosthesis'. Permacol has consistent recurrence rates of 0-15%, whatever the patients' profiles or the context of infected fields, when considering the most relevant studies. The Surgisis results are more conflicting: the mesh exhibits low recurrence rates in clean fields, but in infected fields the recurrence rate is up to 39%.

CONCLUSION

Taken together, these studies suggest that the cross-linked mesh, Permacol has the lowest failure rate and the longest time to failure, particularly in contaminated or infected fields. However, this data should be confirmed by large prospective randomized studies.