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

Phase 2Enrolling By InvitationNCT07628205

Azienda Socio Sanitaria Territoriale Ovest Milanese, Ospedale di Legnano44 enrolled

Overview

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 Type

INTERVENTIONAL

Allocation

NON_RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Enrollment

Conditions

Hernia

Interventions

Posterior Component Separation (PCS) with TARPROCEDURE

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.

Rives-StoppaPROCEDURE

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.

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

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

Outcomes

Primary Outcomes

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.

Time frame: Enrollment, 4 weeks after BTA injection, and 12 months after surgery

Secondary Outcomes

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.

Time frame: until the end of the study