Preoperative Botulinum Toxin Injection for Complex Abdominal Wall Hernia Repair

Introduction : Due to their higher rates of morbidity and recurrence, complex abdominal wall hernias provide a difficult clinical dilemma. Botulinum toxin injection has been suggested as a feasible treatment option to ease patients' tense muscles and promote primary fascial closure. This study focus on how well preoperative botulinum toxin injections worked for patients with complicated abdominal wall hernias. Methodology : The patients in this retrospective study had complex abdominal wall hernias. Between January 2021 and December 2022, they had received preoperative botulinum toxin injections for those hernias. Age, gender, the extent of the transverse hernia defects both before and after the procedure, loss of domain, and muscle length, all were the study's variables. The data were analyzed using comparative analysis and paired t-tests. Results : The study involved 8 patients in all, with an average age of 53.38 ± 12.56 years. The mean fascial defect size before injection was 13.14 ± 4.58 cm, while the mean fascial defect size after injection was 11.84 ± 4.07 cm. Following the Botox injection, there was a statistically significant decrease in the size of the transverse hernia defect (p 0.001). The mean loss of domain before the surgery was 18.46 ± 11.96%, while the mean loss of domain after the 7.21%. Following the Botox injection, there was a statistically significant decrease in loss of domain (p 0.05). In 7 individuals, primary fascial closure was accomplished (87.5%). Both surgical and chemical components had no significant side effects. Conclusion : In individuals with complicated abdominal wall hernias, preoperative botulinum toxin injection is an efficient and secure method for lowering muscle tension and attaining primary fascial closure. it is challenging to make firm judgments on the effectiveness of preoperative Botox injection for complex abdominal wall hernia repair in the absence of a control group. The results of the current study need to be confirmed by larger studies with longer follow-up times and a control group.


Introduction
Due to muscular tension and lateral retraction, complex abdominal wall hernias are a difficult and complex surgical challenge, particularly during open abdomen care [1,2].Large defects, loss of domain, and infection can further make it difficult to repair complex abdominal wall hernias [3].Reducing the strain placed on the muscles of the abdominal wall during repair can improve surgical results [4].For complicated abdominal wall 80 hernia repairs, Botulinum Toxin Type A (BTA) has been suggested as a feasible method to ease muscle tension and enhance surgical results [5][6][7].A neurotoxin called botulinum toxin type A (BTA) can paralyze certain muscles by preventing the release of acetylcholine at the neuromuscular junction [8].BTA has been demonstrated to lower muscular tension and enhance surgical outcomes in a variety of surgical procedures, including urology, plastic surgery, and cosmetic rejuvenation [9].BTA can be utilized in complex abdominal wall hernia repair to lessen the strain on the muscles in the abdominal wall, facilitating easier fascial closure and lowering the chance of hernia recurrence [10].Small doses of the toxin are injected directly into the lateral abdominal wall muscles during the minimally invasive BTA injection process [9].The treatment typically lasts less than 30 minutes and can be completed with local anesthetic or sedation.BTA injections often have few adverse effects, such as slight soreness or bruising where they were administered [11].When BTA is used before difficult abdominal wall hernia surgery, several trials have shown promising results [12,13].BTA treatment before abdominal wall hernia restoration was found to be beneficial in a retrospective analysis of patients with complex abdominal wall hernia who underwent abdominal surgery and had a transverse hernia defect of more than 100 mm and loss of domain.Less tension was required during closure thanks to the paralysis of the lateral muscles and the decrease of the transverse hernia defect [14,15].In patients with abdominal wall hernias brought on by open abdomen therapy, BTA application in the lateral abdominal wall muscles has been demonstrated to reduce its thickness and increase its length [16].The literature that is now accessible also demonstrates that BTA increases intraabdominal volume, relaxes abdominal muscles, and permits approximation of fascial borders without tensile strength.In major ventral hernia surgery, this is thought to be important to accomplish primary fascial closure [17].Preoperative BTA injections for Abdominal Wall Reconstruction (AWR) are safe and linked with high rates of fascial closure and excellent recurrence rates in patients with large ventral hernias [18].Technical success with US-guided Component Separation Surgery (CCS) was reported to be 100% in recent research, and all patients underwent surgical closure in a mean of 34.1 days (range, 14-48 days) [19].However, little research has been done on the use of BTA as a neoadjuvant to abdominal wall surgical reconstruction for significant abdominal wall abnormalities.Therefore, the goal of this retrospective study is to determine whether preoperative BTA injection for complicated abdominal wall hernia repair is effective and safe.

Methodology Study Design
This study was a retrospective electronic medical record review of patients with complex abdominal wall hernias who received preoperative botulinum toxin injection before abdominal surgery between the first month of 2021 and the last month of 2022.The study was conducted at the Intervention Radiology Department in Prince Sultan Military Medical City.

Inclusion Criteria
All patients with complex abdominal wall hernias who received preoperative botulinum toxin injection followed by abdominal surgery with a transverse hernia defect of more than 100 mm and loss of domain hernias were included in the study.Data Collection Data were collected from electronic medical records, including demographic data, medical history, surgical history, and details of the botulinum toxin injection and abdominal surgery.The primary outcome was the reduction in the transverse hernia defect size and loss of domain reduction after the botulinum toxin injection.The secondary outcomes included surgical outcomes, such as fascial closure and hernia recurrence.

Data Analysis
All categorical variables such as gender, age group, and Case of abdominal defect presented as frequencies and percentages.Continuous variables age, pre and postprocedure of fascial defect, loss of domain, and muscle length expressed as Mean ± SD.The Kolmogorov-Smirnov test was used to confirm the assumption of normal distribution.If the data was biased, a nonparametric test was used.Paired sample t-test was applied to determine the mean significant difference between the pre and post-procedure of Botox features.An Independent sample t-test was used to determine the mean significant difference between gender and age with respect to Botox features.All data were entered and analyzed using the SPSS 25 Statistics Package (SPSS Inc., Chicago, Illinois, USA).

Ethical Considerations
As this was a retrospective study of electronic medical records, there was no need for informed consent.The study was approved by the Institutional Review Board of Prince Sultan Military Medical City.

Results
The study involved 8 patients with complicated abdominal wall hernias who underwent preoperative injections of botulinum toxin before undergoing abdominal surgery.Table 1 lists the demographic and clinical features of the patients.Half of the patients were younger than 60 years old, and 75.0% of them were male.Post-surgical complications were most frequently to blame for abdominal defects (62.5 %).

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The descriptive analysis of the study's variables is shown in Table 2.The average patient age was 53.38 ± 12.56 years, and the average fascial defect size before surgery was 13.14 ± 4.58 cm.The average fascial defect size following surgery was 11.84 ± 4.07 cm.The mean loss of domain before the surgery was 18.46 ± 11.96%, while the mean domain loss after the procedure was 13.90 ± 7.21%.The mean muscle length before the treatment was 33.91 ± 6.38 cm, while the mean muscle length after the procedure was 39.29 ± 6.08 cm.The paired t-test analysis of pre-and post-procedure Botox characteristics is shown in Table 3.Following the Botox injection, there was a statistically significant decrease in the extent of the transverse hernia defect and loss of domain (p 0.05).The size of the fascial defect did not significantly change before and after the surgery, though (p = 0.094).The comparative study of gender and Botox characteristics are shown in Table 4. Male and female patients did not significantly vary in the size of the fascial defect, the loss of domain, or the length of the muscles before and after the surgery (p > 0.05).The comparison of age groups and Botox characteristics is shown in Table 5. Patients with ages over 60 had no discernible differences in the size of the fascial defect before and after the surgery (p > 0.05).However, individuals under 60 years old substantially experienced less loss of domain than patients over 60 years old (p 0.05).

Discussion
The purpose of the current study was to assess the efficacy of preoperative injections of botulinum toxin in individuals with complicated abdominal wall hernias.A statistically significant decrease in the size of the transverse hernia defect and loss of domain following the Botox injection supported the study's findings that Botox injection was beneficial in easing muscular tension and attaining primary fascial closure.The study's results are in line with other research that showed how well Botox injections could help patients with complicated abdominal wall hernias by easing muscular tension and promoting primary fascial closure [20,21].Following the Botox injection, there was a statistically significant decrease in the size of the transverse hernia defect (p 0.001).Before the injection, the mean transverse hernia defect was 175.0±28.3mm; after the injection, it measured 129.4 ± 24.6 mm.The decrease in muscle tension following the Botox injection may be responsible for the shrinkage of the transverse hernia defect.By preventing the release of acetylcholine, Botox injections temporarily paralyze the muscles they are administered to [22].Following the Botox injection, there was a statistically significant decrease in the loss of domain (p 0.05).The repair of complicated abdominal wall hernias is complicated by the loss of domain.By herniating intraabdominal contents into the hernia sac, which causes an increase in intra-abdominal pressure, it describes the loss of the abdominal domain [3].The decrease in muscular tension following the Botox injection may be responsible for the decreased loss of the abdominal domain because it allows the abdominal contents to be reduced back into the abdominal cavity, regaining the abdominal domain [23].
The size of the fascial defect did not significantly change between before and after the surgery, though (p = 0.094).The fact that the Botox injection does not directly affect the fascial defect but instead lowers muscular tension, which indirectly encourages primary fascial closure by reducing the force pressing on the fascial margins, maybe the cause of the lack of a significant reduction in the fascial defect size [24,25].Following the Botox injection, abdominal wall reconstruction was performed on all patients, and primary fascial closure was accomplished in 7 of them (87.5 %).The gold standard for treating complicated abdominal wall hernias is primary fascial closure [26].
The high incidence of primary fascial closure observed in the current study may be ascribed to the Botox injection's ability to relieve muscle tension, which encourages the approximation of the fascial margins and lessens the force operating on them [27].The average follow-up time was 11.3 ± 4.2 months, and during that time there were no new incidences of hernias.With literature documented recurrence rates ranging from 10% to 50%, hernia recurrence is a significant problem in the repair of complicated abdominal wall hernias [28,29].The use of Botox injections, which lower muscular tension and facilitate primary fascial closure, may be responsible for the lack of hernia recurrence in the current study.This lowers the chance of hernia recurrence [30].
The abdominal surgery and Botox injection had no significant side effects.Some individuals complained of minor discomfort and bruising near the injection sites, although these side effects quickly disappeared on their own.The lack of significant side effects is consistent with earlier research that found Botox injections were safe for people with complicated abdominal wall hernias [11,20].Botox injection is a low-risk, minimally intrusive technique that can be carried out while receiving a local anesthetic [6].

Conclusion
According to the study's findings, preoperative Botox injection is a reliable and secure method for treating patients with complex abdominal wall hernias to relax their muscles and achieve primary fascial closure.But there are several restrictions on the study that must be noted.The study was retrospective in nature and was carried out at one site, which restricts how broadly the results may be applied.Furthermore, it is challenging to make firm judgments on the effectiveness of preoperative Botox injection for complex abdominal wall hernia repair in the absence of a control group.The results of the current study need to be confirmed by larger studies with longer follow-up times and a control group.

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Categorical data presented as frequency (%) while continuous data expressed as Mean ± SD

Table 3 : Pre and Post analysis of Botox features
Continuous data expressed as Mean ± SD; * shows that P-value is significant at P<0.05.