Under USG use a 7cm micropuncture needle connected to an extension tubing and 60cc syringes filled with the botox 1:1 solution with saline. I traverse all three layers of abdominal musculature at 30-45 degree angles, and have (tech) inject as physician pull back under real time US, thereby lacing the layers with botox realtime. I always do bilateral. I stay below the costal margin and above the iliac crest; I go as far lateral as the mid axillary line and up to but not past the mid clavicular line (so as to exclude the rectus abdominus muscles).

For the botox, I dilute 300 units of botox into 300cc NS and inject 150 units=150cc on each side, under conscious sedation. I also make a skin wheal with lidocaine at each needle entry site for comfort. The number of punctures differs for every pt depending on the size of the space with the borders that I mentioned above. You can go in any direction. I just look for everything to be bathed in botox sonographically.

The potential risks are the usual pain, bleeding, infection. I give 1-2g IV Ancef prophylactically before starting, and use versed and fentanyl to sedate. I don’t really have any contraindications except if a person was to have a h/o anaphylaxis to botox (never had a case). I order the usual preop labs (cbc, inr).

The whole procedure takes less than 30 min. We do it in our holding area and the pt goes home after 1 hour in  PACU. We recommend no heavy lifting for 48 hours. Pts don’t usually look or feel any differently afterwards.

We do the procedure 30 days prior to hernia repair surgery.

Injection Sites

The technique originally described by Ibarra-Hurtado et al. involved 500 IU injected over 5 sites on each side: “two over the midaxillary line, between the costal border and the superior iliac crest, and three over the external oblique muscle” (7). Years later, when Smoot et al. published their experience using BTX for post-op analgesia they described a 3-site, 300 IU technique (8) without specifying the injection sites. This method was then better described in two publications by the same group, describing six injection sites in total: “right/left subcostal; right/left anterior axillary; right/left lower quadrants” (927).

Some have suggested that nearly all published BTX injection protocols adhere to one of these two camps (Ibarra-Hurtado OR Zielinski/Smoot) (18). Groups like the Spanish Bueno-Lledó group have followed the description by Ibarra-Hurtado et al. giving BTX in 5 very similar locations to the Mexican group (3). Others such as Yurtkap et al. and Catalan-Garcia et al. have adopted the Zielinski/ Smoot protocol (1518). Some studies have used mixed protocols, using the higher 500 IU dose but between 3 injection sites (21).

When BTX use was first described, convention was that all three (External Oblique, Internal Oblique and Transversus Abdominus) lateral abdominal wall muscles were infiltrated. This idea has however been challenged in recent years. In their 2020 paper, Elstner et al. conducted a prospective study of 46 patients to assess whether selective 200 IU BTX infiltration of only the 2 most superficial lateral muscle layers could achieve a sufficient medialisation of the rectus muscles (23). Their conclusion that this technique was effective, altered their practise for some patients. This new 200 IU regime was used in patients with certain back complaints, due to Tranversus Abdominis’ key role in thoracic spine stabilisation. This practise has been adopted by other groups (14) who noted no difference in numbers of patients requiring fascial release between 2 and 3 layer infiltration.

Other groups have made use of certain adjuncts to aid the BTX infiltration process. The Bueno-Lledó group routinely use electromyography (EMG) to ensure that the BTX is injected where it is most effective (19). They argue that this establishes whether the targeted muscle is denervated or fibrotic (28).

Ref: https://www.frontiersin.org/articles/10.3389/fsurg.2021.753889/full