Use of Perioperative Pain Blocks In Urological Surgery

Use of Perioperative Pain Blocks In Urological Surgery: A Phase III Randomized Single Blind Single Center Three Arm Non-inferiority Trial

The study team aims to prospectively compare Placebo (local administration), ultrasound-guided transversus abdominis plane (UTAP) blocks, and laparoscopic-guided transversus abdominis plane (LTAP) blocks in patients undergoing robotic surgery of the prostate and kidney. The study team expects to be able to equally efficiently administer the blocks using direct visualization and ultrasound guidance. The study team expects that a negative result would obviate the need for longer operative time by eliminating the need for the separate ultrasound guided block while a positive result would demonstrate the increased utility of preoperative ultrasound blocks in managing postoperative pain.

Currently, ultrasound-guided transversus abdominis plane (UTAP) blocks (regional anesthetic blocks) are being employed for the care of urological surgery patients. Local and regional anesthesia is commonly used throughout surgical fields. However, ultrasound-guidance can be challenging, particularly in larger, obese patients. It is unknown how such techniques compare to laparoscopic-guided blockade, with respect to time to perform, learning curve, and postoperative analgesia. The transversus abdominis plane lies deep within the abdominal wall, potentially allowing for greater ease of access from a laparoscopic approach from within than the ultrasound guided percutaneous approach. Prior randomized studies have been completed comparing UTAP and Placebo. In 2012 Hosgood et al. compared UTAP and placebo (UTAP w/ saline) in 46 live-donor laparoscopic nephrectomy patients (24 UTAP vs. 22 placebo). Pain control (measured using the 0-10 VAS scale) was greater on post-operative day (POD) 1 in patients receiving UTAP than in controls, 19 (15) vs. 37 (20) (presented as mean (SD)), respectively. A similar randomized study in 2014 compared UTAP and placebo (UTAP w/saline) in 21 hand assisted laparoscopic nephrectomy patients (10 UTAP vs. 11 placebo). The study was initially powered for 50 patients but with decreased accrual secondary to a surgeon taking a leave of absence during the study period. Pain scores were recorded using the 0-10 VAS score. Postoperatively at 24 hours (median (IQR)) UTAP patients demonstrated decreased postoperative pain than placebo patients (1 (0-2) vs. 4 (2-6)) on the VAS score, respectively. A larger study, done in 2016, with 80 randomized patients undergoing retroperitoneal laparoscopic urologic surgery compared UTAP (40) and saline UTAP (40). Pain scores were assessed using the 0-100 VAS score scale. On POD1, UTAP group had lower pain scores (mean (SD)) of 8.4 (5.9) vs. placebo 28.3 (12.2). The most recent study, done in 2018, examined 100 randomized patients undergoing robotic-assisted laparoscopic prostatectomies. Fifty patients were given UTAP blocks while the others received no block. A Numerical Rating Scale (assumed to range from 0-10 as not otherwise specified) was used to assess pain. Patients receiving the block at 24 hours had better pain control (mean (SD)) (1.8 (0.82) vs. 3.57 (0.64)). While all of these studies point to potential efficacy of UTAP, no data has been published to date comparing laparoscopic administration of the TAP block (LTAP) to ultrasound guided administration. While these regional anesthetic blocks carry a theoretical risk of hematoma or damage to surrounding structures, none of the above studies report any complications with the injections. The study team aims to prospectively compare Placebo (local administration), UTAP, and LTAP blocks in patients undergoing robotic surgery of the prostate and kidney. The study team expects to be able to equally efficiently administer the blocks using direct visualization and ultrasound guidance. The study team expects that a negative result would obviate the need for longer operative time by eliminating the need for the separate ultrasound guided block while a positive result would demonstrate the increased utility of preoperative ultrasound blocks in managing postoperative pain.

This is a single-center, single-blinded, (stratified) randomized placebo-controlled three-arm non-inferiority trial with 2:2:1 allocation ratio. People who meet eligibility requirements and provide informed consent will be randomly allocated to 3 groups to receive either UTAP, LTAP or Placebo with a 2:2:1 allocation ratio. The allocation sequence will be stratified by type of surgery (prostatectomy or partial nephrectomy) using stratified block randomization with randomly varying block sizes. Random permuted blocks sizes within stratification groups will be used to minimize the chance of selection bias. Investigators will be blinded to the size of each block with only the study statistician responsible for generating the randomization list knowing this information.

A randomization service called Sealedenvelope.com available at https://www.sealedenvelope.com/simple-randomiser/v1/ will be used for allocation concealment to ensure that retrieval of the treatment group assignment is only revealed to appropriate team members on a real time basis after each new patient has been screened and consented. This service allows for allocation concealment that would not be possible if the entire randomization list was made available to team members at the beginning of the study. The security and integrity of the codes used by Sealedenvelope.com follows the Food and Drug Administration (FDA) standards for electronic records and follows the International Conference on Harmonisation Good Clinical Practice (ICH GCP) guidelines. Participants will be blinded to group allocation throughout the study. Due to the nature of the intervention, it is not possible to blind the investigator to group allocation.

30mL of 0.25% bupivacaine will be administered to bilateral TAP using ultrasound guidance in prostatectomies. 40ml 0.25% bupivacaine unilateral will be administered in nephrectomy patients (weight based dosage permitting).

30mL of 0.25% bupivacaine will be administered to bilateral TAP using laparoscopic guidance in prostatectomies. 40ml 0.25% bupivacaine unilateral will be administered in nephrectomy patients (weight based dosage permitting).

Visual analog scale (VAS) is a pain rating scale, with full scale from 0 to 10, higher score indicating more pain

The 24-hour cumulative postoperative opioid analgesic requirement was calculated using standard tables to morphine equivalents.

24 hour postoperative pain scores recorded using the visual analog scale (VAS) in obese patients. Visual analog scale (VAS) is a pain rating scale, with full scale from 0 to 10, higher score indicating more pain. Comparison in patients with BMI >30 and BMI<30

Procedure related complications and adverse events including bleeding or injection of anesthetic intravascular was determined according to Common Terminology Criteria for Adverse Events (CTCAE v 4.0).

Inclusion Criteria: Age 18 years or older Undergoing Robotic Assisted Laparoscopic Partial Nephrectomy or Robotic Assisted Laparoscopic Prostatectomy Ability to understand and the willingness to sign a written informed consent. Exclusion Criteria: Prior Partial Nephrectomy or Subtotal Prostatectomy Surgery (organ specific) Conversion to open surgery History of chronic pain History of opiate or alcohol dependence Allergies to local anesthetic Retroperitoneal surgery Single Port Surgery

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