An interventional study of Sac-flap peritonealization of the mesh and Retromuscular (sublay) synthetic mesh repair in Incisional Hernia, Abdominal Hernia and Complex Ventral Hernia, sponsored by Minia University. Recruiting at 1 site in Egypt. Open to participants aged 18 Years to 75 Years. Per ClinicalTrials.gov, last updated 2026-08-18.
Sponsored by Minia University · Not applicable, Interventional, and Treatment
This trial asks whether covering the inner, bowel-facing surface of a hernia mesh with a flap of the patient's own hernia sac improves healing after repair of a complex ventral (abdominal wall) hernia in which one edge of the defect is bone - for example hernias next to the breastbone and ribs, above the pubic bone, or at the iliac crest.
In these "bony-edged" hernias the mesh is both hardest to fix and hardest to cover. There is no fascia on the bony side for the surgeon to stitch the mesh to, and the lining layer of the abdomen cannot be closed underneath the mesh because the plane that carries it stops at the bone. The mesh may therefore be left in contact with the bowel, which can lead to dense adhesions, mesh erosion, chronic pain and, rarely, a fistula.
Normally the hernia sac - the thin membrane that lines the hernia - is cut away and discarded. In this trial the surgeon instead preserves it as a living, blood-supplied flap, rotates it underneath the mesh, and stitches it in place as a new lining layer that separates the mesh from the bowel and covers the bony edge. The technique uses only the patient's own tissue: no extra mesh, no donor site and no added cost.
One hundred and eighty adults undergoing planned (non-emergency) open repair of a bony-edged complex ventral hernia will be randomly assigned in equal numbers to one of two groups: standard retromuscular (sublay) mesh repair with the added sac flap (90 participants), or standard retromuscular mesh repair alone, with the sac handled in the conventional way (90 participants). Every other step of the operation is the same in both groups.
The main question is whether the sac flap reduces the number of participants who develop any wound or mesh problem in the first 30 days after surgery. This is measured as a composite called a surgical site occurrence, which includes wound infection, seroma, haematoma, skin or soft-tissue death, wound breakdown, mesh exposure and fistula. The trial also compares complications needing a drainage or operative procedure, hernia recurrence at 12 months, overall complication severity, operating time, blood loss, hospital stay, readmission, reoperation, pain, quality of life and death.
Participants, ward and clinic staff, the doctors who assess the wounds, the radiologist who reads the follow-up scans and the trial statistician will not know which operation was performed; only the operating surgeon will. The group assignment is revealed only during the operation, after the surgeon has confirmed that the defect truly has a bony edge and that the sac is suitable for a flap. Participants are followed for 12 months.
BACKGROUND AND RATIONALE Repair of a complex ventral hernia with synthetic mesh in the retromuscular (sublay) position, frequently combined with posterior component separation by transversus abdominis release, is widely regarded as the durable standard of care, but it remains associated with appreciable wound morbidity and a non-trivial recurrence rate. A persistent technical concern is the interface between the prosthesis and the abdominal viscera. When the posterior rectus sheath and peritoneum cannot be re-approximated to fully exclude the mesh from the peritoneal cavity, the prosthesis may be left in contact with bowel, predisposing to dense adhesions, mesh erosion, chronic pain and, rarely, enterocutaneous fistula. Strategies to interpose a protective layer - omentum, composite or biologic meshes, or absorbable barriers - add cost or are not always feasible.
THE BONY-EDGED COMPLEX VENTRAL HERNIA A distinct and under-studied subgroup comprises hernias in which at least one margin of the fascial defect is formed by bone rather than musculo-aponeurotic tissue. These include subxiphoid and costal-margin hernias (bounded by the xiphoid and the costal cartilages), suprapubic hernias (bounded by the pubic symphysis and the superior pubic rami), and selected iliac and lumbar hernias (bounded by the iliac crest). The bony edge poses two specific problems. First, adequate prosthetic overlap and secure fixation on the bony side are difficult, because mesh cannot be sutured to fascia that does not exist. Second, the dissection plane that would normally carry the posterior layer is interrupted at the bone, so the peritoneal layer frequently cannot be closed beneath the mesh. The result is a region where the mesh is simultaneously most difficult to fix and least likely to be covered, concentrating the risk of recurrence and of mesh-related visceral complications precisely at the bony edge.
THE TECHNIQUE UNDER EVALUATION In conventional practice the hernial sac is regarded as redundant tissue and is excised. The technique evaluated in this trial reconceives the sac as a vascularized autologous resource. Rather than excising it, the surgeon preserves a broad, pedicled flap of the hernial sac and rotates it deep to the prosthesis, suturing it as a continuous neo-peritoneal layer that covers the visceral surface of the mesh and bridges the bony edge of the defect. This achieves three aims with a single autologous structure: it interposes living, well-vascularized tissue between the mesh and the bowel, plausibly reducing adhesions, mesh erosion and fistula; it provides soft-tissue coverage and a fixation buttress at the bony margin where fascial purchase is impossible; and it does so without additional prosthetic material, donor-site morbidity or cost. The technique has been applied in selected cases with encouraging operative impressions, but no controlled comparison exists. Equipoise exists: conventional sac excision remains standard practice and is not known to be inferior. A randomized trial is therefore both ethical and necessary before wider adoption.
TRIAL DESIGN This is a single-center, parallel-group, two-arm, individually randomized superiority trial with 1:1 allocation. Both arms share an identical operative approach up to the point of mesh placement, so that the contrast between them is confined to the peritonealization step. Standardization is reinforced by a written operative manual, a pre-trial surgeon training and credentialing phase, a case report form completed in theater, and intra-operative photographic documentation reviewed centrally by the steering group. All index operations are performed by, or under the direct supervision of, credentialed consultant surgeons experienced in retromuscular mesh repair and posterior component separation.
Common operative steps in both arms are: general anesthesia with institutional antibiotic and venous thromboembolism prophylaxis and standardized skin preparation; a midline or location-appropriate incision, dissection to the hernial sac, and full reduction of contents with adhesiolysis as required; definition of the fascial defect including the bony margin, with measurement of defect width and length and recording of the European Hernia Society location and size class; development of the retromuscular (retrorectus) plane, with posterior component separation by transversus abdominis release performed when required to achieve tension-free closure and applied by identical indications in both arms; and placement of a flat, medium-weight monofilament polypropylene mesh of standardized type in the retromuscular position with wide overlap and standardized suture fixation, with anterior fascial closure of the linea alba where achievable.
RANDOMIZATION, ALLOCATION CONCEALMENT AND BLINDING The allocation sequence is computer-generated by the trial statistician using random permuted blocks of variable size with 1:1 allocation, stratified by hernia location (subxiphoid/costal versus suprapubic versus iliac/lumbar) and by defect width (less than 10 cm versus 10 cm or more), because both are expected to influence the primary outcome. Block sizes are not disclosed to recruiting or operating staff. Allocation is concealed using a central, secure randomization service that releases the assignment only after the participant identifiers and stratum are entered and eligibility is confirmed; sequentially numbered, opaque, sealed envelopes prepared by the statistician, who has no clinical contact with participants, serve as a validated fallback.
Participants consent pre-operatively, but allocation is requested and revealed only intra-operatively, after the surgeon has reduced the hernia, confirmed the bony-edged defect and verified that the sac is adequate to raise a covering flap. This timing guarantees that randomization is applied only to participants who genuinely meet the anatomical criteria, eliminates pre-operative selection bias, and ensures that the two arms differ only from the point of mesh placement. The trial coordinator, not the operating surgeon, contacts the randomization service and documents the assignment.
Because the intervention is a surgical step, the operating surgeon cannot be blinded. All other parties are blinded: the participant, ward and clinic staff, the independent outcome assessors who perform the wound and recurrence evaluations, the radiologist who reads the follow-up imaging, and the statistician, who analyzes arms coded A and B. Operative notes that would reveal allocation are stored separately from the assessment record, and a standardized, identical dressing and drain regimen is used in both arms so that early wound appearance does not unblind assessors. Individual unblinding is permitted only when knowledge of allocation is essential for safe clinical management, is recorded with its reason, and is reported to the Data Safety Monitoring Board; the statistician remains blinded until database lock.
SAMPLE SIZE The sample size is driven by the primary outcome. In complex ventral-hernia repair, reported surgical site occurrence rates commonly fall in the 30 to 45 percent range, and a control-arm rate of 38 percent is assumed. A clinically meaningful absolute reduction to 18 percent is hypothesized for the intervention. For the comparison of two independent proportions at a two-sided significance level of 0.05 with 80 percent power, approximately 76 evaluable participants per arm are required. To preserve power against up to 15 percent attrition over 12 months, the target is inflated to 90 per arm, giving a total enrollment of 180 participants.
STATISTICAL ANALYSIS The primary analysis is by intention to treat, with all randomized participants analyzed in the arm to which they were allocated. The 30-day composite surgical site occurrence is compared between arms using a generalized linear mixed (logistic) model with treatment as the fixed effect of interest and the stratification factors as covariates. The treatment effect is reported as an adjusted odds ratio with a 95 percent confidence interval and a two-sided p-value, together with the absolute risk difference, the relative risk and the number needed to treat. A per-protocol analysis is performed as a sensitivity analysis, and a safety set analyzed as treated is used for harms. Binary secondary outcomes are analyzed analogously; recurrence is analyzed by Kaplan-Meier estimation and Cox regression adjusted for the stratification factors; continuous outcomes are analyzed by linear models, or by repeated-measures mixed models for outcomes measured longitudinally. Pre-specified subgroup analyses by hernia location, defect width and use of transversus abdominis release are exploratory and are tested for interaction. Missing data are handled under a missing-at-random assumption, with multiple imputation as a sensitivity analysis. One pre-planned interim analysis is performed at 50 percent recruitment using an O'Brien-Fleming boundary, and the significance level at the final analysis accounts for the alpha already spent. A full statistical analysis plan is finalized and signed before database lock and unblinding.
FOLLOW-UP AND SAFETY Participants are assessed at discharge and at 30 days, 90 days, 6 months and 12 months, with visit windows of plus or minus 7 days for the 30- and 90-day visits and plus or minus 14 days for the 6- and 12-month visits. Adverse events are solicited and recorded from the time of surgery through 12 months and are characterized by severity, seriousness, expectedness and relationship to the intervention, and graded by the Clavien-Dindo classification. Anticipated events of special interest include surgical site infection, seroma (including intra-sac seroma in the intervention arm), hematoma, wound dehiscence, mesh-related complications (exposure, infection, erosion, fistula), sac-flap necrosis, recurrence, reoperation and death. Serious adverse events are reported to the principal investigator, the research ethics committee and the Data Safety Monitoring Board within Good Clinical Practice timelines.
The trial is conducted in accordance with the Declaration of Helsinki and ICH Good Clinical Practice, was designed following the SPIRIT 2013 statement, and will be reported in accordance with the CONSORT 2010 statement. Results will be reported in full regardless of direction, and the registry record will be updated with summary results.
212 studies on the registry are indexed under Incisional Hernia; 58 are open to participants now.
This study's planned enrollment of 180 is above the median of 110 across 130 interventional studies indexed under Incisional Hernia.
Browse Incisional Hernia studies →Minia University is the lead sponsor of 370 studies on the registry; 117 are open to participants now.
Of its 6 completed or terminated interventional studies of FDA-regulated products, 0 (0%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ASA physical status
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Life expectancy
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants undergo standard open retromuscular (sublay) synthetic mesh repair of the bony-edged complex ventral hernia, with posterior component separation by transversus abdominis release where required, PLUS peritonealization of the visceral surface of the mesh with a preserved, pedicled flap of the hernial sac. The sac is not excised. A broad flap is preserved on its vascular pedicle, rotated deep to the prosthesis before mesh fixation, and sutured circumferentially with a slow-absorbable suture to form a continuous autologous neo-peritoneal layer that fully separates the visceral surface of the mesh from the abdominal contents. At the bony margin, the leading edge of the flap is anchored across the bone to provide soft-tissue coverage and a fixation buttress. A closed-suction drain is placed in the retromuscular space.
Procedure: Sac-flap peritonealization of the mesh
Participants undergo standard open retromuscular (sublay) synthetic mesh repair of the bony-edged complex ventral hernia, with posterior component separation by transversus abdominis release where required, and conventional handling of the hernial sac: the sac is excised or simply reduced and is not used to cover the mesh. The visceral surface of the mesh is managed by the operating surgeon's standard practice - re-approximation of the posterior layer where feasible, or omental interposition - without an autologous sac neo-peritoneum and without sac-based coverage of the bony edge. Mesh type, fixation method, drainage and all perioperative care are identical to the experimental arm.
Procedure: Retromuscular (sublay) synthetic mesh repair
The hernial sac is not excised. After reduction of the hernia contents, a broad flap of the sac is preserved on its vascular pedicle. Before the mesh is fixed, the flap is rotated deep to the prosthesis and sutured circumferentially with a slow-absorbable suture to form a continuous neo-peritoneal layer that fully separates the visceral surface of the mesh from the abdominal contents. At the bony margin, the leading edge of the flap is anchored across the bone - to periosteum, to the contralateral posterior layer, or with trans-osseous or peri-osteal sutures as anatomy permits - providing soft-tissue coverage and a buttress where fascial fixation is impossible. Hemostasis of the flap is confirmed and a closed-suction drain is placed in the retromuscular space. No additional prosthetic material and no donor site are used.
Also known as: Pedicled hernial-sac flap; autologous neo-peritonealization; sac-flap neo-peritoneum
Open repair through a midline or location-appropriate incision, with reduction of hernia contents and adhesiolysis as required; definition of the fascial defect including the bony margin, with measurement of defect width and length and recording of the European Hernia Society location and size class; development of the retromuscular (retrorectus) plane, with posterior component separation by transversus abdominis release where required to achieve tension-free closure; placement of a flat, medium-weight monofilament polypropylene mesh of standardized type in the retromuscular position with wide overlap and standardized suture fixation; anterior fascial closure of the linea alba where achievable; and closed-suction retromuscular drainage. This intervention is common to both arms and is delivered identically in each.
Also known as: Sublay mesh repair; Rives-Stoppa retromuscular repair; posterior component separation with transversus abdominis release where indicated
Composite surgical site occurrence (SSO)
Proportion of participants experiencing one or more components of the composite: surgical site infection (per CDC criteria), seroma, hematoma, skin or soft-tissue necrosis, wound dehiscence, mesh exposure, or enterocutaneous fistula. The outcome is binary (present/absent) at the participant level. It is assessed by independent masked outcome assessors using a structured wound proforma with photographic documentation; each component is also recorded individually, with its date of onset and management, so that components can be analyzed separately and so that the subset requiring procedural intervention can be derived.
Time frame: Within 30 days after surgery
Surgical site occurrence requiring procedural intervention (SSOPI)
Proportion of participants with a surgical site occurrence that requires percutaneous drainage, opening of the wound, or operative debridement.
Time frame: 30 days and 90 days after surgery
Hernia recurrence
Proportion of participants with a clinically detected bulge or fascial defect, confirmed on physical examination and cross-sectional imaging (CT or MRI) read by a masked radiologist, or confirmed at reoperation.
Time frame: 6 months and 12 months after surgery
Overall morbidity: highest Clavien-Dindo grade
The highest Clavien-Dindo grade of postoperative complication recorded for each participant. The scale runs from Grade I (any deviation from the normal postoperative course not requiring pharmacological, surgical, endoscopic or radiological intervention) to Grade V (death of the patient); a higher grade indicates a more severe complication.
Time frame: 30 days and 90 days after surgery
Overall morbidity: Comprehensive Complication Index (CCI)
The Comprehensive Complication Index summarizes all postoperative complications for each participant on a continuous scale from 0 (no complication) to 100 (death). Higher scores indicate greater cumulative postoperative morbidity.
Time frame: 30 days and 90 days after surgery
Operative time
Duration of the operation in minutes, measured from skin incision to skin closure.
Time frame: Intra-operative (day of surgery, day 0)
Estimated intra-operative blood loss
Estimated blood loss in milliliters, taken from the anesthetic and surgical record.
Time frame: Intra-operative (day of surgery, day 0)
Length of hospital stay
Number of calendar days from the day of operation to the day of discharge.
Time frame: From surgery to hospital discharge, assessed up to 30 days
Hernia- or wound-related readmission
Proportion of participants readmitted to hospital for any hernia-related or wound-related cause.
Time frame: 30 days and 90 days after surgery
Hernia- or wound-related reoperation
Proportion of participants undergoing any hernia-related or wound-related reoperation.
Time frame: 30 days and 90 days after surgery
Abdominal-wall-specific quality of life (HerQLes)
HerQLes (Hernia-Related Quality of Life Survey), a validated 12-item hernia-specific instrument assessing abdominal-wall function. The summary score is transformed to a 0-100 scale; higher scores indicate better abdominal-wall-related quality of life.
Time frame: Baseline (pre-operative), and at 90 days, 6 months and 12 months after surgery
Hernia-specific quality of life (EuraHS-QoL)
EuraHS-QoL, a validated 9-item hernia-specific instrument covering three domains (pain, restriction of activity, and cosmetic discomfort). Each item is scored from 0 to 10, giving a total score from 0 to 90; lower scores indicate better hernia-specific quality of life.
Time frame: Baseline (pre-operative), and at 90 days, 6 months and 12 months after surgery
All-cause mortality
Proportion of participants who die from any cause.
Time frame: 90 days and 12 months after surgery
Technique-specific adverse events in the experimental arm
Incidence of sac-flap necrosis and of intra-sac (neo-peritoneal) seroma among participants allocated to the sac-flap arm, together with a description of their management.
Time frame: Up to 90 days after surgery
Plan to share: No
Started Aug 2026 (actual). Primary completion is estimated for Aug 2027, 12 months after the start.
Of 59 non-industry interventional studies with no phase under Incisional Hernia, half reached primary completion within 43 months of starting (the median), counting those still running; a quarter within 29 and three quarters within 59. This study's planned 12 months is below that.
Counting every sponsor, half of 66 studies reached it within 43 months; a quarter within 29 and three quarters within 60.
How these figures are worked out, and which studies are left out of them.
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.