Laparoscopic Versus Ultrasound Guided Block in Sleeve Gastrectomy

Introduction and purpose:

Morbid obesity (MO) is a disease that has become a worldwide epidemic, and in the last three decades, the average body mass index (BMI) has increased by 0.4 kg/m2 per decade worldwide. Parallel to this situation, the number of obesity surgery operations is increasing steadily. In 2017, this number reached 228,000 surgeries in the United States. In particular, due to its technical simplicity and positive outcomes, laparoscopic sleeve gastrectomy (LSG) has become the dominant bariatric operation, accounting for approximately 60% of all bariatric procedures (1) These individuals are at high risk for postoperative adverse respiratory events, nosocomial infections, cardiovascular complications, and pulmonary embolism (the second leading cause of death in the bariatric surgery population). Therefore, given the increasing number of patients living with obesity and seeking elective weight loss surgery, it is crucial to understand and optimize the analgesic requirements of this patient population. However, no ideal analgesic regimen exists for this patient population and limited evidence-based recommendations (2) Pain management of the MO patient is an evolving issue and remains extremely important in terms of patient safety and possible addiction risk. Effective postoperative pain management is crucial to encouraging early walking and deep breathing, which are known to reduce the risk of complications. Multimodal analgesia has been advocated by many authors as part of Enhanced Recovery After Surgery (ERAS) programs to reduce the incidence and severity of postoperative pain (3).

Similar to the increase in the number of MOs over the past three decades, opioid use has also increased dramatically. In the United States, opioid overdose has become the leading cause of unintentional death, surpassing motor vehicle crashes. Frequently, the first exposure to opioids may occur during the perioperative period of an elective surgery. It has been reported that approximately 6-8% of opioid-naïve patients undergoing non-cancer procedures develop new persistent opioid use (1). Increased opiate use is associated with increased rates of delirium, ileus, urinary retention, and respiratory depression and may have strong addictive potential. Opioid-induced cardiopulmonary arrest usually occurs within the first 24 hours of surgery (3). Therefore, the surgical team has a critical role in patient management in terms of opioid-independent analgesia control.

To optimize pain control, multimodal anesthesia and regional analgesia have become key components of improved clinical recovery pathways and therefore recommended methods for perioperative pain control. One of these is the transversus abdominis plane (TAP) block, whose effectiveness has been proven in this patient group.

TAP blocks are widely used for intraoperative and postoperative analgesia in various abdominal and gynecological surgeries. There is evidence in the literature that TAP blocks are beneficial in laparoscopic (minimally invasive) surgeries such as laparoscopic cholecystectomy, hernia repair and laparoscopic colorectal resection (4-8). Similarly, in two of the studies demonstrating the feasibility of TAP blocks in laparoscopic bariatric surgery (9,10), it was shown that there was a decrease in pain scores and in another (9) it was shown that it reduced opioid consumption.

Traditionally, the TAP block is completed by an anesthesiologist at the beginning or end of surgery, using ultrasound guidance to improve the accuracy of visualization of the target anatomy and the spread of local anesthesia within the application area (US-TAP). However, in recent years, a new technique has been developed and started to be used during laparoscopic surgery, in which the surgeon can perform the TAP block under direct visualization: laparoscopy-guided TAP block (L-TAP). Numerous studies and technical reports describe this laparoscopic-assisted technique. Studies have shown that laparoscopic-assisted TAP blocks result in similar pain scores and postoperative opioid consumption but lead to shorter block performance time compared to ultrasound-guided block (11). Additionally, a statistically significant decrease was observed in the pain scores and opioid consumption of patients receiving laparoscopic-assisted TAP block compared to controls (12,13). Similarly, in a meta-analysis, it was stated that L-TAP provided comparable analgesia to US-TAP, and there was no statistically significant difference in pain scores at different times and during both rest and movement (14). According to the same meta-analysis, patients in most studies achieved adequate pain control, and 24-hour opioid consumption, incidence of postoperative nausea and vomiting, functional recovery, bowel function, and hospital stay rates did not differ significantly between the 2 methods.