Impact of Quadratus Lumborum Block on Recovery Profile After Ventral Hernia Repair

Current trends in perioperative pain management stress the importance of multimodal analgesia
in an effort to reduce the dependence on opioid pain medications. Adverse effects of opioids
include sedation, respiratory depression, nausea, vomiting, constipation, itching, and, most
importantly, the potential for tolerance and abuse. Multimodal analgesia attempts to utilize
multiple techniques, including medications and nerve block procedures, to improve
postoperative analgesia. Improved postoperative pain control can enable an earlier return to
normal activities for patients, not only improving patient satisfaction, but also reducing
postoperative morbidity and adverse effects of opioids.

Approximately 350,000 to 500,000 ventral hernia repairs are performed each year in the United
States. Surgeries completed laparoscopically are typically performed on an outpatient basis,
allowing patients to return home the same day of surgery and treat their pain independently
with prescribed pain medications. Utilization of a regional anesthesia technique may allow
prolonged numbing of the nerves postoperatively and decrease the reliance on oral pain
medications. Transversus abdominis plane (TAP) blocks have been shown to decrease pain scores
and opioid consumption following ventral hernia repair. Quadratus lumborum (QL) blocks are
newer iterations of the TAP block.

There are currently three types of the QL block, all targeting the thoracolumbar fascia
surrounding the quadratus lumborum muscle. Injection within this fascial plane may allow
local anesthetic spread into the paravertebral space, possibly explaining why QL blocks have
been mapped from the T7 to T12/L1 dermatomes, covering the entire abdomen. Conversely, TAP
blocks have been mapped from the T10 to T12/L1 dermatomes, only covering the abdomen below
the umbilicus. In the first, the Quadratus lumborum 1 block (QL1), the local anesthetic is
injected within the fascial plane lateral to the QL muscle. In the second, the Quadratus
lumborum 2 block (QL2), the needle trajectory is more superficial, and the local anesthetic
is injected along the posterior border of the QL muscle. The third iteration, the Quadratus
lumborum 3 block (QL3), involves a deeper, transmuscular approach with injection along the
anterior border of the QL muscle. Our study would utilize the QL2 approach as the dermatomal
distribution of the QL1 and QL2 blocks appear to be more widespread than the QL3 block, and
the QL2 block may be a safer approach due to the more superficial angle of the needle 3.

Additionally, the QL block has been shown to have a longer duration of analgesia when
directly compared to the TAP block. A study of pediatric lower abdominal surgery revealed
improved pain scores and parent satisfaction with care in the QL group compared to TAP block.
This improvement persisted to the 24 hour mark. In a study of postoperative pain following
cesarean delivery, pain scores were improved and opioid consumption decreased with the QL
block compared to the TAP block. The differences were not significant at the 1 and 6 hour
marks, but were significant at the 12, 24 and 48 hour marks, highlighting the analgesic
duration of the QL block 8.

This study aims to evaluate the efficacy of the QL block using the QL2 approach on recovery
profile after laparoscopic ventral hernia repair, a commonly performed surgery, as well as
contribute to the understanding of the block and its distribution of anesthesia.

Inclusion Criteria:

1. The subject is scheduled for elective laparoscopic ventral hernia repair;

2. The subject is ≥ 18 years and ≤ 80 years;

3. The patient agrees to receive a quadratus lumborum block

4. American Society of Anesthesiologists class 1-3.

Exclusion Criteria:

1. Subject is < 18 years of age or >80 years of age;

2. Subject is non-English speaking;

3. Subject is known or believed to be pregnant;

4. Subject is a prisoner;

5. Subject has impaired decision-making capacity per discretion of the Investigator;

6. Significant renal, cardiac or hepatic disease per discretion of the investigator;

7. American Society of Anesthesiologists class 4-5;

8. Known hypersensitivity and/or allergies to local anesthetics;

9. Chronic opioid use (daily or almost daily use of opioids for > 3 months at any point
in their lives).

10. Repair of a recurrent ventral hernia

11. Repair of multiple ventral hernias

12. Unobtainable sonographic views

13. Lacking health insurance