Response to the letter on “Comments to ‘PRevention of INCisional hernia after liver transplantation (PRINC trial): study protocol for a randomized controlled trial’ by Janusz Strzelczyk”
Trials volume 21, Article number: 326 (2020)
To the editor,
We are very grateful to Dr. Janusz Strzelczyk for showing interest in the study protocol “PRevention of INCisional hernia after liver transplantation (PRINC trial): study protocol for a randomized controlled trial”  and for communicating his concerns about choosing an absorbable mesh for incisional hernia prevention after liver transplantation (LT). Indeed, to the best of our knowledge, this study is the first to investigate incisional hernia prevention with a synthetic mesh placed with the usual onlay technique during abdominal wall closure in LT.
Prophylactic onlay mesh placement has been very successfully investigated in non-immunosuppressed patients, and results of the PRIMA study, a randomized controlled trial, were published recently . Furthermore, synthetic meshes have been used uneventfully (especially without increased surgical side infections) in immunosuppressed patients with existing incisional hernia . However, our study combines, for the first time, the prophylactic onlay approach with a resorbable mesh after LT. This study is important since (a), especially early after LT, immunosuppression is high and wound healing is compromised and (b) non-resorbable meshes are prone to get superinfected or to induce seroma with associated problems [4, 5].
Moreover, during the early post-operative course after LT, factors such as malnutrition due to end-stage liver disease and large abdominal surgery further increase the risk for inflammation, infection, and less effective collagen synthesis, resulting in a higher incidence of incisional hernia. The articles cited by Dr. Strzelczyk are not focused on the early post-transplant period. They only compare hernia following LT during the long-term follow-up with hepatopancreatic surgery  or focus on the late post-operative period after LT . These studies have not shown an increased incidence of incisional hernia recurrence that is due to long-term immunosuppression. The clear working hypothesis is that prophylactic placement of a slow resorbable mesh during LT should protect against the most frequently occurring hernias during the early post-operative course .
Even with non-resorbable onlay placed meshes, recurrent hernias are reported in up to 32% of midline incisions within 5 years . Most importantly, the surgical skill of abdominal wall repair is the only independent factor for the recurrence of an incisional hernia, according to the “expertise in abdominal wall surgery matters” trial, in which experts had only 12% recurrent hernias, which was almost 60% lower than in the non-expert group .
Results concerning the use of biological and bio-absorbable meshes were presented recently . The data analysis demonstrated that both biological and bio-absorbable meshes could not be recommended for the use of complex hernia repair. In case of biological meshes increased inflammatory activity and inacceptable high recurrence rates occurred. Bio-absorbable meshes were not investigated sufficiently for a routine recommended use. The successful use of P4HB meshes was shown by a multicenter study group [11, 12] that performed a multicenter prospective study including contaminated ventral hernia repairs. The recurrence rate was 9% after 4 years in the US study group and after 2 years in the European study group. Both results were presented at international conferences (of the Americas Hernia Society and the European Hernia Society (EHS)). Our own observation study of 46 patients with complex and mostly contaminated ventral hernia showed a 4-year recurrence rate of 6% (presented at the EHS meeting, 2019).
In conclusion, the PRINC study protocol is based on both local and international data and therefore represents an appropriate attempt to prevent the most prevalent early occurrence of post-transplant hernias.
Availability of data and materials
European Hernia Society
PRevention of INCisional hernia after liver transplantation
Kniepeiss D, Waha J, Auer T, Berghold A, Schemmer P. PRevention of INCisional hernia after liver transplantation (PRINC trial): study protocol for a randomized controlled trial. Trials. 2019;20(1):371.
Jairam AP, Timmermans L, Eker HH, Pierik REGJM, van Klaveren D, Steyerberg EW, et al. Prevention of incisional hernia with prophylactic onlay and sublay mesh reinforcement versus primary suture only in midline laparotomies (PRIMA): 2-year follow-up of a multicentre, double-blind, randomised controlled trial. Lancet. 2017;390:567–76.
Lam HD, Vanlander A, Berrevoet F. A comparative outcome analysis of incisional hernia repair in patients who underwent liver transplantation vs. those that underwent hepatopancreaticobiliary surgery using the EHS guidelines as a means of comparison. Clin Transpl. 2016;30:226–32.
Klinge U, Junge K, Spellerberg B, Piroth C, Klosterhalfen B, Schumpelick V. Do Multifilament Alloplastic Meshes Increase the Infection Rate? Analysis of the Polymeric Surface, the Bacteria Adherence, and the In Vivo Consequences in a Rat Model. Biomed Mater Res. 2002;63:765–71.
Engelsman AF, Van der Mei HC, Ploeg RJ, Busscher HJ. The phenomenon of infection with abdominal wall reconstruction. Biomaterials. 2007;28:2314–27.
Haskins IN, Krpata DM, Prabhu AS, Tastaldi L, Perez AJ, Tu C, et al. Immunosuppression is not a risk factor for 30-day wound events or additional 30-day morbidity or mortality after open ventral hernia repair: An analysis of the Americas Hernia Society Quality Collaborative. Surgery. 2018;164:594–600.
Harlaar JJ, Deerenberg EB, Dwarkasing RS, Kamperman AM, Kleinrensink GJ, Jeekel J, et al. Development of incisional herniation after midline laparotomy. BJS Open. 2017;1:18–23.
Juvany M, Hoyuela C, Carvajal F, Trias M, Martrat A, Ardid J. Longterm follow-up (at 5 years) of midline incisional hernia repairs using a primary closure and prosthetic onlay technique: recurrence and quality of life. Hernia. 2018;22:319–24.
Pereira JA, Bravo-Salva A, Montcusí B, Pérez-Farre S, Fresno de Prado L, López-Cano M. Incisional hernia recurrence after open elective repair: expertise in abdominal wall surgery matters. BMC Surg. 2019;19:103.
Köckerling F, Alam NN, Antoniou SA, Daniels IR, Famiglietti F, Fortelny RH, et al. What is the evidence for the use of biologic or biosynthetic meshes in abdominal wall reconstruction? Hernia. 2018;22:249–69.
Roth JS, Anthone GJ, Selzer DJ, Poulose BK, Bittner JG, Hope WW, et al. Prospective evaluation of poly-4-hydroxybutyrate mesh in CDC class I/high-risk ventral and incisional hernia repair: 18-month follow-up. Surg Endosc. 2018;32:1929–36.
Van Rooijen MMJ, Jairam AP, Tollens T, Jørgensen LN, de Vries Reilingh TS, Piessen G, et al. A post-market, prospective, multi-center, single-arm clinical investigation of Phasix™ mesh for VHWG grade 3 midline incisional hernia repair: a research protocol. BMC Surg. 2018;18:104–12.
Stoikes NFN, Scott JR, Badhwar A, Deeken CR, Voeller GR. Characterization of host response, resorption, and strength properties, and performance in the presence of bacteria for fully absorbable biomaterials for soft tissue repair. Hernia. 2017;21:771–82.
Deeken CR, Matthews BD. Characterization of the mechanical strength, resorption properties and histological characteristics of a fully absorbable material (Polpy-4-hydroxybutyrate-PHASIX Mesh) in a porcine model of hernia repair. ISRN Surg. 2013;2013:238067.
Ethics approval and consent to participate
Consent for publication
The authors declare that they have no competing interests.
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
About this article
Cite this article
Auer, T., Kniepeiss, D. & Schemmer, P. Response to the letter on “Comments to ‘PRevention of INCisional hernia after liver transplantation (PRINC trial): study protocol for a randomized controlled trial’ by Janusz Strzelczyk”. Trials 21, 326 (2020). https://doi.org/10.1186/s13063-020-04244-y