Preoperative Botulinum Toxin A to Facilitate Midline Closure in Large Chronic Ventral Hernias (Probhe)

Prehabilitation With Botulinum Toxin A in Complex Hernia: an Italian Prospective Study on Predictive Scores of Myofascial Release.

In patients with large hernias, chronic retraction of the lateral abdominal wall muscles, and visceral contents that are irreducible within the hernia sac, closure of the midline can be difficult or even impossible. Component separation techniques (CST), in combination with transversus abdominis release (TAR), increase the flexibility of the abdominal wall and facilitate fascial medialization. However, these techniques alter the anatomy of the abdominal wall and are associated with higher risks of wound complications, abdominal wall disruption, and abdominal compartment syndrome (ACS).

Recently, the preoperative injection of Botulinum Toxin A (BTA) has been proposed as an effective form of chemical component separation of the muscles, or more precisely, chemical relaxation. It has been hypothesized that preoperative chemical paralysis of the lateral abdominal wall muscles through BTA increases abdominal wall compliance and facilitates fascial medialization, thereby reducing the need to resort to CST.

However, the current literature still lacks studies evaluating the impact of BTA on predictive scores for myofascial release and the correlation with intraoperative strategies.

Study Overview

• Status: Enrolling by invitation
• Conditions: Hernia
• Intervention / Treatment: Procedure: Posterior Component Separation (PCS) with TAR; Procedure: Rives-Stoppa

• Study Type: Interventional
• Enrollment (Estimated): 44
• Phase: Phase 2

Contacts and Locations

Study Locations

• Italy
  • Milano
    • Legnano, Milano, Italy, 20025
      • Asst Ovest Milanese

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Participant is willing and able to give informed consent for participation in the trial
• Compliance to follow-up
• Male and female
• Written informed consent to preoperative BTA injection and/or surgery
• Age 18 years old
• Primary ventral hernia
• Incisional ventral hernia
• RDR < 2
• Defect width 10 cm
• Loss of domain (LoD) 20%

Exclusion Criteria:

• Medical or psychiatric conditions that compromises the patient's ability to give informed
• consent or comply with the study protocol
• Personal reasons
• Age < 18 years old
• RDR ≥ 2
• Defect width < 10 cm
• LoD < 20%
• Pregnancy and breastfeeding
• Allergy/Intolerance to BTA
• Neuromuscular disorders and diseases
• Refuse to give informed consent to preoperative BTA injection and/or surgery

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Posterior Component Separation (PCS) with TAR after BTA injection.	Procedure: Posterior Component Separation (PCS) with TAR; Posterior Component Separation (PCS) with Transversus Abdominis Release (TAR) is an intraoperative surgical technique performed by the surgeon when a standard retromuscular repair, such as the Rives-Stoppa technique, does not allow for tension-free midline closure. In such cases, additional myofascial release is required, and PCS with TAR is subsequently performed to achieve adequate medial advancement of the abdominal wall components and enable secure, tension-free closure of the midline defect.
Experimental: Rives-Stoppa surgery after BTA injection	Procedure: Rives-Stoppa; Rives-Stoppa repair is a retromuscular abdominal wall reconstruction technique used when primary fascial closure can be achieved without the need for additional myofascial release. It represents a less invasive approach compared to component separation techniques, such as Posterior Component Separation with Transversus Abdominis Release (PCS with TAR), and is performed in cases where tension-free midline closure is feasible using a standard retromuscular plane dissection.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Improvement in Preoperative Indices Following Botulinum Toxin A Injection	Changes in preoperative radiological indices following Botulinum Toxin A (BTA) injection will be assessed using abdominal computed tomography (CT) scans. The Rectus-to-Defect Ratio (RDR) will be calculated on pre- and post-injection CT imaging; each 0.5-point increase in RDR is associated with an approximate 20% linear reduction in the need for anterior myofascial release (AMR). The Component Separation Index (CSI) will be determined on axial CT images using the aorta as a fixed reference point and the medial borders of the rectus abdominis muscles. Abdominal cavity volume will be estimated using the ellipsoid volume formula based on craniocaudal, transverse, and anteroposterior diameters measured on CT imaging. Pre- and post-BTA values will be compared to evaluate improvement in abdominal wall compliance and anatomical reconstruction parameters.	Enrollment, 4 weeks after BTA injection, and 12 months after surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Association Between Changes in Preoperative Indices After Botulinum Toxin A Injection and Surgical Strategy Selection.	Two surgical strategies will be considered based on abdominal wall reconstruction requirements: (A) Posterior Component Separation (PCS) with Transversus Abdominis Release (TAR), and (B) Rives-Stoppa repair, performed when no myofascial release is required. For PCS with TAR procedures, the Posterior Bridging Ratio (PBR) and Anterior Bridging Ratio (ABR) will be assessed as the proportion of the peritoneal sac used as a bridge to achieve tension-free closure of the posterior and anterior fascial layers, respectively. The extent of ABR and PBR will be analyzed in relation to the preoperative effect of Botulinum Toxin A (BTA) injection. In particular, higher percentages (>50%) of PBR and ABR will be considered indicative of poor BTA efficacy, intermediate values (25-50%) of partial efficacy, and low values (0-25%) of good to very good BTA efficacy. The relationship between changes in preoperative indices after BTA administration and the selected surgical approach will be evaluated.	until the end of the study

Collaborators and Investigators

• Sponsor: Azienda Socio Sanitaria Territoriale Ovest Milanese, Ospedale di Legnano

Study record dates

Study Major Dates

• Study Start (Actual): February 17, 2026
• Primary Completion (Estimated): January 1, 2029
• Study Completion (Estimated): February 17, 2029

Study Registration Dates

• First Submitted: May 14, 2026
• First Submitted That Met QC Criteria: June 3, 2026
• First Posted (Actual): June 4, 2026

Study Record Updates

• Last Update Posted (Actual): June 4, 2026
• Last Update Submitted That Met QC Criteria: June 3, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pathological Conditions, Anatomical; Pathological Conditions, Signs and Symptoms; Hernia
• Other Study ID Numbers: 57-2024; 2025-522451-25-00 (Ctis)

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No