Prometheus: Prophylactic Mesh After OLtx for Hernia Reduction Study.

STUDY DESIGN Multicenter, prospective, consecutive case series study.

OBJECTIVE The main purpose of the study is to determine whether a bio-absorbable mesh is effective and safe in the prevention of incisional hernia in high risk patients undergoing LT.

Primary endpoint:

• To evaluate the incidence of incisional hernias after LT in a consecutive series of patients that meet the inclusion criteria after conventional abdominal wall closure plus placement of a bio-absorbable mesh in an onlay position, at two years of follow-up.

Secondary endpoint:

• Incidence of IH in different type of incision subgroups
• Incidence of surgical site occurrences
• Surgical site infection
• Seroma
• Evisceration (abdominal dehiscence)
• Mesh complications
• Incidence of general complications
• Incidence of IH in different subset of patients undergoing immunosuppressants (steroids, mTORi)

MATERIALS & METHODS

• multicenter prospective, consecutive case series study: conventional closure technique (according to each center policy) + bio-absorbable mesh placed in an onlay position, with two-year-follow-up.

PATIENTS ENROLLMENT From the protocol start date all the transplant candidates that meet the inclusion criteria will be enrolled at time of LT by any of the surgeons who belongs to the centers involved in this trial, and an informed consent will be obtained. During the one year enrolling period we aim to include 100 consecutive patients in the study.

DURATION OF SUBJECT PARTICIPATION AND DURATION OF STUDY Subjects will be on study for 24 months. Treatment: day 0 Follow-up: 8 days, 30 days, 3, 6, 12, 18, 24 months The total duration of the study is expected to be 3 years. One year for subjects recruitment and 24 months for final subjects follow-up.

SURGICAL PROCEDURES The technique used for surgical incision and for abdominal wall closure will follow each participating center policy. A slowly absorbable material will be used for closure by all centers.

After conventional closure a bio-absorbable mesh will be placed in a onlay position (PHASIX - C. R. Bard, Inc/Davol Inc, Warwick, RI). The above mentioned meshes are currently available in the participating centers.

The surgeons will be specifically trained in using a prophylactic onlay mesh. An overlapping of 3 cm must be obtained on every side of surgical incision. Fixation methods allowed: interrupted long- term absorbable suture. Subcutaneous and skin closure following center practice. The operating surgeon can decide for the placement of a subcutaneous drain if necessary.

PATIENT FOLLOW-UP An intention to treat analysis is planned. Patient follow up will be carried out in the outpatient clinic at 30 DAYS, 3, 6, 12, 18 and 24 months by any surgeon involved in the trial.

Inclusion criteria

• Have at least 3 of the following pre transplant risk factors for IH (definition of high Risk Patients):

• Age >60
• Sex M
• Obesity (HR 1.74, 1.04 to 2.91) (16) (BMI equal to or higher than 30 kg/m², according WHO definition)
• Smoker (OR 3.93, 1.82 to 8.49) (14). An adult who has smoked at least 100 cigarettes in his or her lifetime, and who now smokes every day, according WHO definition.
• Diabetes (OR 6.68, 2.02 to 22.0) (14) as defined by Centers of Disease Control and Prevention):

Result A1C Test Fasting Blood Sugar Test Glucose Tolerance Test Random Blood Sugar Test Diabetes 6.5% or above 126 mg/dL or above 200 mg/dL or above 200 mg/dL or above

• IRC according KDIGO definition: "CKD is defined as abnormalities of kidney structure or function, present for >3 months, with implications for health," and requires one of two criteria documented or inferred for >3 months: either GFR <60 ml/min/1.73 m2 or markers of kidney damage, including albuminuria.
• MELD > 22 (16)
• COPD (HR 2.35, 1.44 to 3.83) (16): previous diagnosis of emphysema, chronic bronchitis, and chronic obstructive asthma. In pulmonary function testing, a postbronchodilator FEV1/FVC ratio of <0.70 is commonly considered diagnostic for COPD according The Global Initiative for Chronic Obstructive Lung Disease (GOLD) system.
• Moderate/Large ascites at time of transplant. The International Ascites Club classifies the severity classification of ascites as follows: moderate ascites (grade 2): moderate abdominal distention, large ascites (grade 3): marked abdominal distention.
• Sarcopenia (if diagnosed with CT-scan or RM). The study of the muscular compartment at the level of the third lumbar vertebra (L3) by CT is the gold standard technique in the assessment of sarcopenia. (10) The sum of the areas of psoas, erector spinae, multifidus, quadratus lomborum, rectus of the abdomen, transverse and internal and external obliques are divided by the squared height of the patient and define the skeletal muscle index: SMI (Skeletal Muscle Index) = SMA (Skeletal Muscle Area) (cm²) / height (m²). Sarcopenia is defined by cut-off values below 41,6 cm²/m² for men and 32 cm²/m² for women.

Exclusion criteria

• retransplant, previous upper quadrants laparotomies, previous incisional hernia repair, umbilical hernia > 2cm in diameter, pre-Tx steroids treatment or immunosuppression, patient's rejection to participate.