New “biological” meshes: the need for a register. The EHS Registry for Biological Prostheses
- First Online:
- Cite this article as:
- Ansaloni, L., Catena, F., Coccolini, F. et al. Hernia (2009) 13: 103. doi:10.1007/s10029-008-0440-7
- 103 Views
Non-absorbable prosthetic materials in hernia surgery can cause relatively rare complications, which include chronic pain, a feeling of stiffness with reduced compliance of the abdominal wall, prosthetic erosion/fistulisation and an increased risk of persistent deep infection. Recently, to avoid these problems, new “biological” prosthetic materials have been developed and proposed for clinical use. These materials are all essentially composed of an extracellular matrix stripped of its cellular components, and differ substantially only in their source (porcine small intestine submucosa, porcine dermis or cadaveric human dermis). Because of the numerous variables involved, it is very difficult to conduct a randomised controlled trial. Therefore, the European Hernia Society (EHS) has decided to start the EHS Registry for Biological Prostheses (ERBP). This is a prospective registry in Europe on the use of collagen meshes in (potentially) contaminated circumstances or clean surgical fields. The registry intends to collect some preoperative data on the patient and indication, intraoperative data and outcome data.
KeywordsBiological prosthesesHerniaContaminated fields
In the last 20 years, with the introduction of the “tension-free” techniques of hernia repair based on the use of alloplastic, non-absorbable prosthetic materials, we have witnessed an important revolution and a wonderful change in terms of a lower recurrence rate in the treatment of all hernias. The use of non-absorbable prosthetic materials such as polypropylene, polyester and ePTFE have, hence, expanded and are now widely used in reparative surgery for abdominal wall hernias [1, 2].
When implanted, these non-absorbable materials—although extremely biocompatible—stimulate a foreign-body reaction within the host. After the initial inflammatory phase, an intense deposition of fibrotic tissue ensures a firm ingrowth that explains their success in hernia surgery, but this may also be the reason for occasional complications, which can include chronic pain, a feeling of stiffness with reduced compliance of the abdominal wall, prosthetic erosion/fistulisation and an increased risk of persistent deep infection [3–8]. These complications might be eliminated by the use of absorbable prosthetic materials, such as those composed of polyglactin or polyglycolic acid. However, the use of these absorbable prostheses exposes the patient to a rapid and inevitable hernia recurrence, as these materials, once implanted, are attacked by an inflammatory reaction that, through a hydrolytic reaction, removes and digests the implanted prosthetic material completely. A new type of reduced-material/large-pore prosthesis with lower weight than the current materials might also decrease the above-mentioned potential complications, but long-term data with respect to integrity and the prevention of recurrence are lacking for the moment.
Recently, new “biological” prosthetic materials have been developed and proposed for clinical use. These materials are all essentially composed of an extracellular matrix stripped of its cellular components, and differ substantially only in their source (porcine small intestine submucosa, porcine dermis or cadaveric human dermis) [9–11]. In contrast to current prosthetic repairs, where the prosthesis is intended to strengthen the defect life-long, the extracellular matrix implanted into the host has a direct strengthening function only initially. Subsequently, the matrix is gradually degraded while inducing neovascularisation and colonisation by host cells that progressively cause a site-specific “remodelling process” until the reconstruction of a new and mature autologous fascia is complete. Finally, this mature structure restores the original supportive function of the abdominal wall [12–15].
This field of tissue engineering identifies that branch of reparative medicine that plans the creation in vivo or in vitro of vital and functioning tissues or organs . This process involves three essential components: tissue/organ-specific cells, a scaffold (in most cases, an extracellular matrix essentially collagen-based) with a function of support for tissue/organ formation, and physical and chemical signals. These interacting signals that occur between cells and scaffold direct a site-specific tissue reconstruction .
The weakest point chronologically in this remodelling process is the moment with minimal tensile strength due to advanced prosthetic degradation but only minimal initial remodelling . Especially in the case of infection, increased collagenase production might enhance prosthetic degradation and lead to early graft failure. In order to increase early graft stability and induce a more organised collagen deposition, materials with cross-linked collagen molecules have been proposed, but, theoretically, they might negatively influence the remodelling process with the prolonged presence of chemically linked collagen molecules, leading to prosthetic encapsulation . However, new cross-linking methods (using EDAC or HMDI) or varying levels of cross-linking might decrease this risk.
This new generation of prostheses might open up a new era in the treatment of abdominal wall hernias, but also in the prevention of hernias after the closure of laparostomies at risk [17–25]. Though in some patients, a certain collagen disease might be present (e.g. patients with aortic abdominal aneurysm), leading to remodelling with collagen of inferior quality. In such cases, the ingrowth and remodelling process could, theoretically, be enhanced by using these materials as scaffolds for the use of stem cells, fibroblasts or growth factors [25–32].
However, significant controversy remains. Scientific data, especially in humans and with long-term follow-up concerning recurrence rate and other complications are lacking. In addition, the cost of these materials is extremely high and, therefore, many surgeons are reluctant to use these materials in their current practice. Apart from its potential use in the treatment of specific hernias such as paraoesophageal hiatus hernia or parastomal hernia, where the use of non-resorbable synthetic materials might cause some long-term intestinal erosion, the most appealing indication for the moment is the use in patients with a high risk for infection. These include immunodepressed patients or rare situations such as sepsis or (clean) contaminated or dirty/infected surgery, where the use of the same non-resorbable synthetic materials is not advocated because of the increased risk for prosthetic infection [32–50].
Because of the many variables involved, it is very difficult to perform a randomised controlled trial on this subject. Therefore, the European Hernia Society (EHS) has decided to start the EHS Registry for Biological Prostheses (ERBP). This is a prospective registry in Europe on the use of collagen meshes in (potentially) contaminated circumstances or clean surgical fields. Registries have the potential to demonstrate what happens in the real surgical world and the usefulness of their outcome data in guiding surgeons’ daily practice has clearly been shown in the large-scale inguinal hernia registry and database in the Scandinavian countries (Danish Hernia Database, Swedish Hernia Register). The registry will start in 2008 and is supported by Bard, Cook and Lifecell. The registry intends to collect some preoperative data on the patient and indication, intraoperative data and outcome data. All data will be registered in a central database after coding, ensuring patient and surgeon anonymity. A coworker from the central database location will contact every surgeon to obtain the outcome data after 1 and 12 months. Every participant will be able to obtain all of the data from his/her own centre. In order to increase the chances for systematic consecutive inclusion of as many patients as possible, the registration form will be provided with every purchase of such a biological prosthesis and the documentation will be actively supported by the participating companies.
Finally, each scientific paper using ERBP data will contain all of the participating surgeons’ names as authors (“ERBP group”).