Complex abdominal wall hernias pose a difficult problem due to their higher rates of morbidity and recurrence. Using botulinum toxin injections as a potential treatment to stretch the patients' muscles and promote primary fascial closure has been suggested. This study focuses on the effectiveness of preoperative botulinum toxin injections for patients with complicated abdominal wall hernias.
Methodology: This retrospective study included patients with complex abdominal wall hernias who received preoperative botulinum toxin injections between January 2021 and October 2023. The study examined variables such as age, gender, size of the hernia defects, without and loss of domain and muscle length. The data were analysed through comparative analysis and paired t-tests.
Results: This study included 11 patients with an average age of 51.38 ± 11.56 years. The average size of the fascial gap decreased notably after receiving injections of botulinum toxin. There was also a statistically significant reduction in the loss of domain post-injection. Primary fascial closure was successfully attained in 10 participants, with no significant adverse effects.
Conclusion: Utilizing botulinum toxin injection prior to surgery in patients with complex abdominal wall hernias proves to be a reliable and successful method in alleviating muscle tension and ensuring proper fascia closure. While the effectiveness of preoperative Botox injection in repairing complex abdominal wall hernias cannot be definitively determined without a control group, further comprehensive studies with extended follow-up periods and control groups are essential to validate the findings of this study.
Complex abdominal wall hernias pose a formidable surgical challenge due to muscular tension and lateral retraction, especially in the context of open abdomen care [1,2]. Repairing those hernias can be made even more difficult by large defects, loss of domain, and infection [3]. One way to improve surgical outcomes is to reduce the strain on the abdominal wall muscles during repair [4]. In the case of complicated repairs, some experts have proposed using Botulinum Toxin Type A (BTA) as a viable method for easing muscle tension and enhancing surgical results [5-7].
Botulinum toxin type A, also known as BTA, is a neurotoxin that can cause paralysis in specific muscles by blocking the release of acetylcholine at the neuromuscular junction [8]. It has been shown to reduce muscle tension and improve the results of various surgical procedures in fields such as urology, plastic surgery, and cosmetic rejuvenation [9]. In complex abdominal wall hernia repair, BTA can help reduce strain in the abdominal wall muscles, this helps to simplify the closure of the fascia and decrease the chances of hernial recurrence [10].
In the minimally invasive process of BTA injection, small amounts of the toxin are injected directly into the muscles of the lateral abdominal wall [9]. This treatment usually takes less than 30 minutes and can be done with local anaesthesia or minor sedation. BTA injections generally result in minimal side effects, such as mild soreness or bruising at the injection site [11]. Literature indicates that using BTA before complex abdominal wall hernia surgery has shown promising results in several trials [12,13]. A retrospective analysis found that BTA treatment before abdominal wall hernia repair benefited patients with large hernia defects and loss of domain. It reduced the tension required during closure and furthermore, decreased the size of the hernia defect, due to the paralysis of the lateral muscles [14,15].
Research has indicated that using BTA on the lateral abdominal muscles can decrease their thickness and increase their length for patients undergoing open abdomen therapy. Additionally, BTA may raise the volume of the intra-abdominal cavity, relax muscles, and help bring the fascial borders closer without causing tension. This is crucial for successfully achieving primary fascial closure during major ventral hernia surgery. Before undergoing Abdominal Wall Reconstruction (AWR), receiving BTA injections is safe and linked to high rates of fascial closure and low recurrence rates in patients with large ventral hernias [16-18]. New studies indicate that US-guided Component Separation Surgery (CCS) has achieved a technical success rate of 100%, and patients have undergone surgical closure within a mean of 34.1 days (ranging from 14 to 48 days) [19]. However, there is limited research on the use of BTA as a neoadjuvant for surgical reconstruction of major abdominal wall abnormalities. Therefore, this retrospective study seeks to assess the efficiency and safety of preoperative BTA injection for repairing complex abdominal wall hernias.
This research involved revision of electronic medical records for patients with complicated abdominal wall hernias who were given botulinum toxin injections before undergoing abdominal surgery between January 2021 and October 2023. The study took place at the Intervention Radiology Department in Prince Sultan Military Medical City, Riyadh, Saudi Arabia.
The study encompassed all patients who had intricate abdominal wall hernias and underwent preoperative botulinum toxin injection, followed by abdominal surgery for a transverse hernia defect exceeding 100 mm, as well as loss of domain hernias.
Data were collected from electronic medical records; this includes demographic data, medical/surgical history, together with details of the botulinum toxin injection and abdominal surgery. The primary outcome was overall reduction in the transverse hernia defect size as well as the loss of domain reduction after the botulinum toxin injection. The secondary outcomes included surgical outcomes, such as successful fascial closure and -if any- hernial recurrence.
Categorical variables such as gender, age group, and Case of abdominal defect were represented as frequencies and percentages. Continuous variables like age, pre- and post-procedure fascial defect, loss of domain, and muscle length were expressed as Mean ± SD. The Kolmogorov-Smirnov test was utilized to verify the assumption of normal distribution. In the case of biased data, a nonparametric test was employed. The paired sample t-test was used to assess the mean significant difference between the pre- and post-procedure features. Meanwhile, an independent sample t-test was utilized to determine the mean significant difference between gender and age in relation to Botox features. All data were entered and analysed using the SPSS 25 Statistics Package (SPSS Inc., Chicago, Illinois, USA).
Since this was a review of past electronic medical records, there was no requirement for informed consent. Approval for the study was granted by the Institutional Review Board at Prince Sultan Military Medical City.
The study examined 11 patients who had complex abdominal wall hernias and received pre-surgical botulinum toxin injections.
Table 1 details the patients' demographic and clinical characteristics, indicating that 54.5% of the patients' abdominal defects resulted from post-surgical complications, and most of them were male (64%).
Table 1: Demographic and clinical characteristics of patients (n = 11). View Table 1
The descriptive analysis in Table 2 shows that the average patient age was 51.38 ± 11.56 years, with an average fascial defect size before procedure of 13.14 ± 4.58 cm. After the procedure, the average fascial defect size decreased to 11.84 ± 4.07 cm. The mean loss of domain before the procedure was 18.46 ± 11.96%, while the mean domain loss after the procedure was 13.90 ± 7.21%. The mean muscle length was 33.91 ± 6.38 cm prior to the procedure, compared to 39.29 ± 6.08 cm post-procedure.
Table 2: Descriptive analysis of the study variables. View Table 2
Furthermore, Table 3 reveals that there was a statistically significant reduction in the transverse hernia defect and loss of domain following Botox injections (p 0.05). However, the size of the fascial defect did not show significant change post-surgery (p = 0.094).
Table 3: Pre and post-analysis of botox features. View Table 3
The comparison analysis in Table 4 shows that male and female patients did not significantly differ in terms of fascial defect size, loss of domain, or muscle length. Similarly, Table 5 demonstrates that age did not have a significant impact on the size of the fascial defect (p > 0.05), although younger patients experienced less loss of domain compared to the older patients (p 0.05).
Table 4: Comparative analysis between gender and botox features. View Table 4
Table 5: Comparative analysis for gender and botox features. View Table 5
The aim of the present study was to evaluate the effectiveness of botulinum toxin injections before surgery in individuals with complex abdominal wall hernias. The study demonstrated a noteworthy reduction in the size of the hernia defect and loss of domain after the Botox injection, affirming the conclusion that Botox injection was advantageous in relieving muscular tension and achieving primary fascial closure (Figure 1). These findings align with previous research indicating the positive impact of Botox injections on patients with complex abdominal wall hernias by alleviating muscular tension and facilitating primary fascial closure [20,21].
Figure 1: Preoperative axial CT comparison image of baseline (pre-BTA) and post-BTA treatment, demonstrating the elongation and thinning of the lateral abdominal oblique muscles, as well as the reduction in defect width after BTA treatment. The final post-surgical CT scan is shown as well.
View Figure 1
After receiving a Botox injection, there was a notable decrease in the size of the transverse hernia defect, as indicated by statistical significance (p 0.001). The mean transverse hernia defect measurement decreased from 147.0 ± 3.82 mm before the injection to 129.4 ± 37.3 mm after. The reduction in muscle tension and the muscle lengthening post-Botox injection could be attributed to the shrinkage of the transverse hernia defect. Botox injections work by temporarily paralyzing muscles through preventing the release of acetylcholine [22].
Following the Botox injection, there was a statistically meaningful reduction in the loss of domain (p 0.05). Complex abdominal wall hernia repair is complicated by the loss of domain. This refers to the herniation of intra-abdominal contents into the hernia sac, leading to an increase in intra-abdominal pressure, which is responsible for the loss of abdominal domain [3]. The reduction of muscle tension after receiving a Botox injection may contribute to the decrease in abdominal protrusion by allowing the contents of the abdomen to return to their original position within the abdominal cavity, thereby restoring the abdominal domain [23].
The size of the fascial opening did not demonstrate a noteworthy change before and after the procedure, with a p-value of 0.094. The lack of a significant decrease in the fascial defect size may be attributed to the Botox injection's indirect impact on reducing muscular tension, thereby indirectly promoting primary fascial closure by alleviating pressure on the fascial margins [24,25]. Following the Botox injection, all patients underwent abdominal wall reconstruction, resulting in primary fascial closure in 10 individuals (90.9%).
The most effective method for treating complex abdominal wall hernias is the primary closure of the fascia [26]. The significant success of primary fascial closure seen in the present study can be attributed to the Botox injection's ability to reduce muscle tension, thereby promoting the alignment of the fascial edges and reducing the stress placed on them [27].
The average follow-up was 18.3 ± 9.2 months, with no recurrence of hernias were reported during this period. Hernia recurrence is a major concern in the repair of complex abdominal wall hernias, with documented rates ranging from 10% to 50% in the literature [28,29]. The potential role of Botox injections in reducing muscle tension and aiding in the primary closure of the fascia may account for the absence of hernia recurrence in the present study, ultimately reducing the risk of hernia recurrence [30].
The abdominal surgery and Botox injection did not cause any notable adverse effects. A few people experienced slight discomfort and bruising around the injection areas, but these side effects resolved quickly. This aligns with previous studies suggesting that Botox injections are safe for individuals with complex abdominal wall hernias [11,20]. The use of Botox injection is a low-risk, minimally invasive procedure that can be performed under local anaesthesia [6].
The findings of this study indicate that using Botox injections before surgery are a safe and effective method for treating patients with complex abdominal wall hernias by relaxing their muscles and achieving primary fascial closure. However, it is important to acknowledge certain limitations of the study. This was a retrospective study that was conducted at a single site, which limits the generalizability. Moreover, it is difficult to draw definitive conclusions about the effectiveness of preoperative Botox injection for complex abdominal wall hernia repair without a control group. It is necessary for larger studies with longer follow-up periods and control groups to validate the results of the current study.