Clinical trial NCT03702153: The Use of Synthetic Mesh in Contaminated and Infected Abdominal Wall Repairs. A Long-term Prospective Clinical Trial
Official title: The Use of Synthetic Mesh in Contaminated and Infected Abdominal Wall Repairs: Challenging the Dogma of an Absolute Contra-indication. A Long-term Prospective Clinical Trial
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Abdominal Wall Defect
Abdominal Wall Infection
Abdominal Wall Fistula
Infection
Keywords: ventral hernia
mesh infection
enteric fistula
polypropylene mesh
synthetic mesh
abdominal wall reconstruction
complex hernia
Lead sponsor: University of Sao Paulo General Hospital
Sponsor class: OTHER
First posted: 2018-10-10
Enrollment: 80
Sex: ALL
Minimum age (years): 18
Maximum age (years): 85
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: NON_RANDOMIZED
Intervention model: PARALLEL
Intervention model description: A study group submitted to abdominal wall repair with synthetic mesh in the contaminated/infected setting compared to a control group submitted to abdominal wall repair with synthetic mesh in the clean setting.
Primary purpose: TREATMENT

Brief summary: Background: Abdominal wall reconstruction in patients presenting with enteric fistulas and mesh infection is challenging. There is a consensus that synthetic mesh must be avoided in infected operations. The alternatives to using synthetic mesh, such as component separation techniques and biologic mesh, present disappointing results with expressive wound infection and hernia recurrence rates.

Methods: A prospective clinical trial designed to evaluate the short and the long-term outcomes of patients submitted to elective abdominal wall repair with synthetic mesh in the dirty-infected setting, and compared to a cohort of patients submitted to clean ventral hernia repairs.

Detailed description: We designed a prospective study, evaluating the short and the long-term outcomes of the surgical treatment of 40 consecutive patients presenting with an infected abdominal wall, compared to a cohort of 40 patients submitted to clean ventral hernia repairs. Patients were admitted between January 2012 and February 2015, and operated at the Hospital das Clinicas of the University of São Paulo School of Medicine, in Brazil. All patients included in the study group carried an active chronic mesh infection (mesh sinus, exposed mesh or mesh related enteric fistulas) resulting from a previous hernia repair, with or without an associated recurrent ventral hernia. All the operations required in this group were classified as Class IV (dirty-infected), accordingly to the CDC Wound Classifications, as adopted by the European registry for abdominal wall hernias. The only inclusion criterion was the presence of an active chronic mesh infection. The infected abdominal wall (IM) group and the outcomes of the treatment were compared to a clean-control (CC) group of patients who underwent clean abdominal wall reconstructions, originally belonging to a prospective study of the tensiometry of the abdominal wall, and operated during the same period and in the same conditions. The exclusion criteria were: giant ventral hernias with a volume ratio higher than 25%, patients on immunosuppressive therapy or using corticosteroids, patients with hepatic cirrhosis and portal hypertension, Chron´s disease, acute postoperative mesh infection, chronic mesh infections following inguinal hernia repair and emergency operations.The data assessed included gender, age, body mass index (BMI), American Society of Anesthesiologists (ASA) score, comorbidities, smoking status, cancer history, the number of previous abdominal operations, the number of prior hernia operations, the presence of a recurrent incisional hernia and/or enteric fistula and the presentation of the mesh infection. Perioperative data included operative time, anesthesia time, associated procedures, the defect characteristics and the extension of the pre-aponeurotic dissection. Further analysis in the infected mesh (IM) group included the type and position of the infected mesh, the causes for the mesh infection and the microbiology of mesh explants. Patients were followed and operated at the Abdominal Wall and Hernia Repair Unit of the General Surgery and Trauma Discipline, and five surgeons of the team conducted the operations in both groups. Informed consents were presented to the patients in the IM group upon admission. Patients in the CC group signed informed consents to participate the study, during their post-operative follow-up visits.

Surgical procedure The operations were performed through the previous surgical incision. Patients in the IM group had the infected mesh removed completely together with all the sutures, tacks or other foreign material. The surrounding fibrotic tissue and the existing sinus tracts were resected to perform a complete toilet of the abdominal wall. The abdominal cavity was entered in most of the patients, and associated or incidental procedures were made as required. After the removal of the infected mesh, or at the end of the abdominal cavity workup, all the surgical drapes, instruments and gloves were replaced. The size of the defect and the extension of the anterior abdominal wall dissection were estimated. The reconstruction of the midline was done as anatomically as possible, by repositioning of the muscles and primary closure of the aponeurosis. We did not use component separation techniques or transverse abdominal releases in any case. In some patients, a bilateral relaxing incision along the anterior rectus sheath was required to allow the re-approximation of the muscles in the midline. In all patients, a heavyweight macroporous (pore size \> 75µm) monofilament polypropylene mesh (Intracorp®, Venkuri, www.venkuri.com.br) was used in the onlay position, to reinforce the repair. The mesh was fixed with multiple absorbable Vicryl® sutures, placed over the borders of the mesh, in the midline and along the relaxing incisions. The remaining dead space between the mesh and the underlying tissue was cleared entirely with interrupted sutures. The operative field was irrigated with 0,9% saline, and the subcutaneous was drained with suction drains. The scars and the exceeding skin flaps were resected. We did not use irrigation with antibiotics solution. The subcutaneous tissue and the skin were closed with interrupted sutures. Fluids and samples of the explanted mesh were sent to cultures and microbiological analysis. The same technique of repair was used in the CC group. The size of the defect was measured, and the extension of the anterior abdominal wall dissection was estimated. A bilateral relaxing incision along the anterior rectus sheath was used routinely in this group, to allow a tensionless closure of the midline.

Outcomes parameters The primary outcomes variables were the presence of any surgical site occurrences (SSO) or surgical site infection (SSI) during the first 30 days after the operation, and the development of hernia recurrence or the recurrence of mesh infection during a 36-month follow-up period. Suspected recurrences of a hernia or infection were determined by physical examination and CT scan imaging. Non-surgical complications, other operations, and deaths were registered during the follow-up period.

Statistical Analysis The chi-square test was conducted to verify the association between categorical variables in contingency tables and the Fisher exact test was adopted in 2x2 tables whenever at least one expected frequency was less than 5. The U-test was used for verifying the association between continuous data and group with two categories, and when normal distribution was observed the Student t-test was performed. The 5% level of significance was considered for all statistical tests. Statistical computer Stata software version 10.0 (StataCorp, College Station, TX) was used for conducting all statistical analysis.

Eligibility criteria: "Inclusion Criterion"

- the presence of an active chronic mesh infection

"Exclusion Criteria"

* giant ventral hernias with a volume ratio higher than 25% and loss of domicile
* patients on immunosuppressive therapy or using corticosteroids
* patients with hepatic cirrhosis and portal hypertension
* Chron´s disease
* acute postoperative mesh infection
* chronic mesh infections following inguinal hernia repair
* emergency operations.

Primary outcomes:
measure: Surgical site occurrence
timeFrame: 30 days
Secondary outcomes:
measure: Surgical Site infection
timeFrame: 30 days
measure: Surgical site occurrence requiring procedural intervention
timeFrame: 30 days
measure: Ventral hernia recurrence
timeFrame: 36 months
measure: Mesh infection recurrence
timeFrame: 36 months
Other outcomes:
measure: Microbiology of mesh infection
timeFrame: 30 days
Locations:
city: São Paulo
country: Brazil
facility: Hospital das Clinicas da FMUSP
Study officials:
affiliation: Hospital das Clínicas da FMUSP
name: Claudio Birolini, MD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Choi JJ, Palaniappa NC, Dallas KB, Rudich TB, Colon MJ, Divino CM. Use of mesh during ventral hernia repair in clean-contaminated and contaminated cases: outcomes of 33,832 cases. Ann Surg. 2012 Jan;255(1):176-80. doi: 10.1097/SLA.0b013e31822518e6.
citation: Szczerba SR, Dumanian GA. Definitive surgical treatment of infected or exposed ventral hernia mesh. Ann Surg. 2003 Mar;237(3):437-41. doi: 10.1097/01.SLA.0000055278.80458.D0.
citation: Johnson EK, Tushoski PL. Abdominal wall reconstruction in patients with digestive tract fistulas. Clin Colon Rectal Surg. 2010 Sep;23(3):195-208. doi: 10.1055/s-0030-1262988.
citation: Franklin ME Jr, Trevino JM, Portillo G, Vela I, Glass JL, Gonzalez JJ. The use of porcine small intestinal submucosa as a prosthetic material for laparoscopic hernia repair in infected and potentially contaminated fields: long-term follow-up. Surg Endosc. 2008 Sep;22(9):1941-6. doi: 10.1007/s00464-008-0005-y. Epub 2008 Jul 2.
citation: Miserez M, Fitzgibbons RJ Jr, Schumpelick V. Hernia surgery and contamination: biological mesh and nothing else? Hernia. 2013 Feb;17(1):1. doi: 10.1007/s10029-013-1044-4. Epub 2013 Jan 17. No abstract available.
citation: Itani KM, Rosen M, Vargo D, Awad SS, Denoto G 3rd, Butler CE; RICH Study Group. Prospective study of single-stage repair of contaminated hernias using a biologic porcine tissue matrix: the RICH Study. Surgery. 2012 Sep;152(3):498-505. doi: 10.1016/j.surg.2012.04.008. Epub 2012 Jul 3.
citation: Rosen MJ, Denoto G, Itani KM, Butler C, Vargo D, Smiell J, Rutan R. Evaluation of surgical outcomes of retro-rectus versus intraperitoneal reinforcement with bio-prosthetic mesh in the repair of contaminated ventral hernias. Hernia. 2013 Feb;17(1):31-5. doi: 10.1007/s10029-012-0909-2. Epub 2012 Mar 14.
citation: Rosen MJ, Krpata DM, Ermlich B, Blatnik JA. A 5-year clinical experience with single-staged repairs of infected and contaminated abdominal wall defects utilizing biologic mesh. Ann Surg. 2013 Jun;257(6):991-6. doi: 10.1097/SLA.0b013e3182849871.
citation: Birolini C, Utiyama EM, Rodrigues AJ Jr, Birolini D. Elective colonic operation and prosthetic repair of incisional hernia: does contamination contraindicate abdominal wall prosthesis use? J Am Coll Surg. 2000 Oct;191(4):366-72. doi: 10.1016/s1072-7515(00)00703-1.
citation: Antonopoulos IM, Nahas WC, Mazzucchi E, Piovesan AC, Birolini C, Lucon AM. Is polypropylene mesh safe and effective for repairing infected incisional hernia in renal transplant recipients? Urology. 2005 Oct;66(4):874-7. doi: 10.1016/j.urology.2005.04.072.
citation: Birolini C, de Miranda JS, Utiyama EM, Rasslan S. A retrospective review and observations over a 16-year clinical experience on the surgical treatment of chronic mesh infection. What about replacing a synthetic mesh on the infected surgical field? Hernia. 2015 Apr;19(2):239-46. doi: 10.1007/s10029-014-1225-9. Epub 2014 Feb 9.
citation: Birolini C, de Miranda JS, Tanaka EY, Utiyama EM, Rasslan S, Birolini D. The use of synthetic mesh in contaminated and infected abdominal wall repairs: challenging the dogma-A long-term prospective clinical trial. Hernia. 2020 Apr;24(2):307-323. doi: 10.1007/s10029-019-02035-2. Epub 2019 Sep 6.